United States
Environmental Protection
Agency
Office of
Research and Development
Washington, DC 20460
EPA/625/6-91/014
June 1991
Technology Transfer
&EPA Handbook
Control Technologies for
Hazardous Air Pollutants
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EPA/625/6-91/014
June 1991
Handbook
Control Technologies for
Hazardous Air Pollutants
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
Printed on Recycled Paper
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Notice
The information in this document has been funded wholly, or in part, by the U.S.
Environmental Protection Agency (USEPA) under Contract No. 68-C8-0011,
Work Assignment No. 1-31, issued to Pacific Environmental Services, Inc. (PES),
as a subcontractor to the Eastern Research Group, Inc. Mention of trade names
or commercial products does not constitute endorsement or recommendation for
use.
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Acknowledgment
This Handbook was prepared by Michael K. Sink, Pacific Environmental Ser-
vices, Inc., for the U.S. Environmental Protection Agency's Center for Environ-
mental Research information (CER1) in conjunction with the EPA Control Tech-
nology Center. Carlos Nunez, Air and Energy Engineering Research Laboratory
(AEERL), and Justice Manning, CERI, Office of Research and Development,
served as technical project managers. Special acknowledgment is given to
William M. Vatavuk for guidance on sources of cost information and a detailed
review of Chapter 4. Peer review was provided by Robert H. Borgwardt, AEERL,
and William J. Neuffer, Office of Air Quality Planning and Standards.
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Preface
This document is a revision of the first (1i86) edition of the Handbook. (See
Reference 1, Section 1.3).
An associated project of upgrading a personal computer software package to
accompany this handbook was undertaken concurrently and funded by the
Control Technology Center (CTC). The software program (HAP PRO, version 1}
is a revision of the earlier CAT (Controlling Air Toxics) program and is available
from the CTC by calling 919/541-0800. (The CTC has plans to install the
software on the CTC Bulletin Board, which is part of the OAQPS Technology
Transfer Network, for ease of access to those with communication capabilities.
Information on its availability may be obtained through the above-listed telephone
number.) The handbook was the basis for the software design. This software was
designed to be user-friendly and to duplicate the manual calculations of the
handbook from user input data. The purpose of the software is to provide easy
access to the calculations! techniques in the handbook for those who have
access to a personal computer.
The CTC was established by EPA's Offices of Research and Development and
Air Quality Planning and Standards to provide technical assistance to State and
focal air pollution control agencies and EPA regional staff on air pollution control
issues. Three levels of assistance can be accessed through the CTC. First, a
CTC Hotline has been established to provide telephone assistance on matters
relating to air pollution control technology. Second, more in-depth engineering
assistance can be provided when appropriate. Third, the CTC can provide
technical guidance through publication of technical guidance documents, devel-
opment of personal computer software, and presentation of workshops on control
technology matters.
IV
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Contents
Page
Notice ii
Acknowledgment Hi
Preface iv
Figures ...be
Tables x
Nomenclature , xiv
Conversion Factors , xxi
Chapter 1 Introduction f .....1-1
1.1 Background and Objective. 1-1
1.2 How to Use the Handbook „ , 1-2
1.3 References •... 1-5
Chapter 2 HAP Emissions by Source Category and
Key Physical Properties 2-1
2.1 Background 2-1
2.2 Identification of Potential HAPs and
Emission Sources 2-2
2.2.1 Solvent Usage Operations 2-3
2.2.2 Metallurgical industries ........2-4
2.2.3 Synthetic Organic Chemical Manufacturing
Industry (SOCM!). 2-4
2.2.4 Inorganic Chemical Manufacturing
Industry.... 2-7
2.2.5 Chemical Products Industry 2-7
2.2.6 Mineral Products Industry 2-7
2.2.7 Wood Products Industry 2-7
2.2.8 Petroleum Related industries 2-7
2.2.9 Combustion Sources 2-9
2.3 Identification of Key Emission Stream
Properties 2-12
2.4 References 2-14
Chapter 3 Control Device Selection 3-1
3.1 Background 3-1
3.2 Vapor Emissions Control 3-1
3.2.1 Control Techniques for Organic Vapor
Emissions from Point Sources ,3-1
3.2.2 Control Techniques for Inorganic Vapor
Emissions from Point Sources 3-6
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Contents (continued)
Page
3.2.3 Control Techniques for Organic/
Inorganic Vapor Emissions from
Process Fugitive Sources 3-7
3.2.4 Control Techniques for Organic/
Inorganic Vapor Emissions from
Area Fugitive Sources 3-10
3.2.5 Control Device Selection for a
Hypothetical Facility 3-10
3.3 Particulate Emissions Control 3-11
3.3.1 Control Techniques for Particulate
Emissions from Point Sources 3-11
3.3.2 Control Techniques for Particulate
Emissions from Fugitive Sources ,,....3-15
3.4 References ,,.....3-23
Chapter 4 Design and Cost of HAP Control Techniques 4-1
4.1 Background 4-1
4.2 Thermal Incineration 4-1
4.2.1 Data Required 4-3
4.2.2 Pretreatment of the Emission Stream:
Dilution Air Requirements 4-3
4.2.3 Design Variables, Destruction
Efficiency, and Typical Operational
Problems 4-3
4.2.4 Determination of Incinerator
Operating Variables 4-5
4.2.5 Evaluation of Permit Application 4-6
4.2.6 Capital and Annual Costs of Thermal
Incinerators 4-7
4.2.7 References 4-10
4.3 Catalytic Incineration.. 4-10
4.3.1 Data Required 4-11
4.3.2 Pretreatment of the Emission Stream 4-12
4.3.3 Design Variables, Destruction
Efficiency, and Typical Operational
Problems 4-12
4.3.4 Determination of Incinerator
Operating Variables 4-14
4.3.5 Catalyst Bed Requirement ..4-16
4.3.6 Evaluation of Permit Application., 4-16
4.3.7 Capital and Annual Costs of
Catalytic Incinerators 4-16
4.3.8 References 4-20
4.4 Flares , 4-20
4.4.1 Data Required 4-20
4.4.2 Determination of Flare Operating
Variables..... 4-21
VI
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Contents (continued)
Page
4.4.3 Evaluation of Permit Application 4-23
4.4.4 Capital and Annual Costs of Flares 4-23
4.4.5 References .4-27
4.5 Boiler/Process Heaters , 4-27
4.6 Carbon Adsorption : 4-28
4.6.1 Data Required ..,„.„ , ...4-28
4.6.2 Adsorption Theory 4-28
4.6.3 Design Parameters ...„„. 4-29
4.6.4 Pretreatment of the Emission Stream ..4-29
4.6.5 Typical Operational Characteristics,
Problems, and Adsorber Types 4-30
4.6.6 Fixed Bed Regenerative Systems 4-30
4.6.7 Evaluation of Permit Application 4-34
4.6.8 Capital and Annual Costs of Fixed
Bed Regenerative Adsorbers 4-34
4.6.9 Carbon Canister System Design 4-41
4.6.10 Capital and Annual Costs of
Canister Systems 4-42
4.6.11 References •. 4-44
4.7 Absorption „ 4-44
4.7.1 Data Required 4-45
4.7.2 Absorption System Design Variables 4-45
4.7.3 Determination of Absorber System
Design and Operating Variables ....4-46
4.7.4 Evaluation of Permit Application 4-51
4.7.5 Capital and Annual Costs of Absorbers 4-52
4.7.6 References 4-54
4.8 Condensers 4-55
4.8.1 Data Required '. 4-56
4.8.2 Pretreatment of the Emission Stream 4-56
4.8.3 Condenser System Design Variables ....4-56
4.8.4 Evaluation of Permit Application 4-59
4.8.5 Capital and Annual Costs of Condensers 4-59
4.8.6 References 4-64
4.9 Fabric Filters 4-64
4.9.1 Data Required 4-65
4.9-2 Pretreatment of the Emission Stream 4-65
4.9.3 Fabric Filter System Design Variables 4-65
4.9.4 Determination of Baghouse Operating
Parameters ;; ;.. 4-70
4.9.5 Evaluation of Permit Application 4-71
4.9.6 Capital and Annual Costs of Fabric Filters ....4-71
4.9.7 References 4-79
4.10 Electrostatic Preciprtators 4-80
4.10.1 Data Required 4-81
vii
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Contents (continued)
Page
4.10.2 Pretreatment of the Emission Stream 4-81
4.10.3 ESP Design Variables ...4-81
4.10,4 Evaluation of Permit Application ..4-82
4.10.5 Determination of ESP Operating Parameters 4-84
4.10.6 Capital and Annual Costs of ESP
Systems 4-85
4.10.7 References 4-90
4.11 Venturi Scrubbers .....4-90
4.11.1 Data Required 4-91
4.11,2 Pretreatment of the Emission Stream 4-91
4.11.3 Venturi Scrubber Design Variables 4-91
4.11.4 Sizing of Venturi Scrubbers 4-93
4.11.5 Evaluation of Permit Application 4-94
4.11.6 Capital and Annual Costs of
Venturi Scrubbers 4-94
4.11.7 References .4-98
4.12 Costs of Auxiliary Equipment .4-98
4.12.1 Fan Purchase Cost 4-98
4.12.2 Ductwork Purchase Cost 4-100
4.12.3 Stack Purchase Cost 4-100
4.12.4 Damper Purchase Cost 4-100
4.12.5 Cyclone Purchase Cost 4-101
4.12.6 References 4-101
Appendices
A.1 Listing of Compounds Currently Considered
Hazardous A.1-1
A.2 Toxic Air Pollutant/Source Crosswalk A.2-1
A.3 Potential HAPs for Solvent Usage Operations A.3-1
B.1 Gas Strearn Parameters Calculations B.1-1
B.2 Dilution Air Requirements Calculations ....B.2-1
B.3 Gas Stream Conditioning Equipment B.3-1
C.1 HAP Emission Stream Data Form C.1-1
C.2 Calculation Sheet for Dilution Air Requirements C.2-1
C.3 Calculation Sheet for Thermal Incineration C.3-1
C.4 Calculation Sheet for Catalytic Incineration C.4-1
C.5 Calculation Sheet for Flares C.5-1
C.6 Calculation Sheet for Carbon Adsorption C.6-1
C.7 Calculation Sheet for Absorption C.7-1
C.8 Calculation Sheet for Condensation C.8-1
C.9 Calculation Sheet for Fabric Filters C.9-1
C.10 Calculation Sheet for Electrostatic
Precipitators C.10-1
C.11 Calculation Sheet for Venturi Scrubbers C.11-1
C.12 Calculation Sheet for Auxiliary Equipment C.12-1
viii
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Figures
Number Page
1.1 Steps Used When Responding to Inquires........ 1-3
1.2 Steps Used When Reviewing Permits ...1-4
2,1 HAP Emission Stream Data Form 2-2
2.2 Potential Emission Points for Vacuum Distillation Column 2-6
3.1 Approximate Percent Reduction Ranges for
Add-On Equipment , ; „ 3-2
3.2 Effluent Characteristics for Emission Stream #1 3-11
3.3 Effluent Characteristics for Emission Stream #2 ,3-12
3.4 Effluent Characteristics for Emission Stream #3 ...3-13
3.5 Effluent Characteristics for Emission Stream #4 3-14
3.6 Effluent Characteristics for Emission Stream #5 3-15
3.7 Effluent Characteristics for Emission Stream #6 3-17
3.8 Effluent Characteristics for Emission Stream f7 ..,......; 3-19
3.9 Effluent Characteristics for a Municipal
Incinerator Emission Stream 3-20
4.2-1 Schematic Diagram of a Thermal Incinerator 4-2
4;3-1 Schematic Diagram of a Catalytic Incinerator System 4-11
4.4-1 Typical Steam Assisted Flare 4-21
4.6-1 Typical Two Bed Regenerative Carbon
Adsorption System 4-31
4.7-1 Typical Countercurrent Packed Column Absorber ............4-44
4.7-2 Flooding Correlation in Randomly Packed Towers 4-46
4.7-3 Relationship between N^, AF, and Efficiency 4-48
4.7-4 Costs of Absorber Towers 4-50
4,8-1 Flow Diagram for Typical Refrigerated
Condenser System 4-55
4.8-2 Vapor Pressure Temperature Relationship 4-57
4.8-3 Costs for Fixed Tubesheet Condensers 4-61
4.8-4 Costs for Floating Head Condensers 4-61
4.9-1 Structure Costs for Intermittent Shaker Filters 4-73
4,9-2 Structure Costs for Continuous Shaker Filters .....4-73
4.9-3 Structure Costs for Pulse-Jet Filters (Common Housing)... 4-74
4.9-4 Structure Costs for Pulse-Jet Filters (Modular) 4-74
4.9-5 Structure Costs for Reverse-Air Filters -...'. 4-75
4.9-6 Structure Costs for Custom Built Filters ....4-75
4.10-1 Chart for Finding SCA „. 4-84
4.10-2 Cost of Plate Wire and Flat Plate ESP Structures 4-87
4.10-3 Costs of Two-Stage ESP Structures .......4-88
4.11-1 Typical Venturi Scrubber Performance Curve 4-92
4.11-2 Psychrometric Chart 4-95
B.1-1 Acid Dew Points in Stack Gases..... ..B.1-3
IX
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Tables
Number Page
2.1 Potential HAPs and Emission Sources for
Solvent Usage Operations 2-3
2.2 Potential HAPs and Emission Sources for
Metallurgical Industries 2-5
2.3 Emission Sources for the SOCMI 2-6
2.4 Potential HAPs for Inorganic Chemical
Manufacturing Industry 2-8
2.5 Potential HAPs and Emission Sources for the
Chemical Products Industry 2-10
2.6 Potential HAPs for the Mineral Products Industry 2-11
2.7 Potential HAPs for the Wood Products Industry... 2-12
2.8 Potential HAPs for Petroleum Related
' Industries (General) ...2-12
2.9 Potential HAPs for Petroleum Refining
Industries (Specific) ,...2-13
2.10 Emission Sources for the Petroleum Related Industries 2-13
2.11 Potential HAPs and Emission Sources for
Combustion Sources 2-14
2.12 Key Properties for Organic Vapor Emissions 2-15
2.13 Key Properties for Inorganic Vapor Emissions 2-15
2.14 Key Properties for Paniculate Emissions ..2-15
3.1 Key Emission Stream and HAP Characteristics for
Selecting Control Techniques .3-2
3.2 Control Methods for Various Inorganic Vapors 3-7
3.3 Summary of Control Effectiveness for Controlling
Organic Process Fugitive Emission Sources 3-8
3.4 Range of Capture Velocities 3-9
3.5 Key Characteristics for Particulate Emission Streams 3-13
3.6 Advantages and Disadvantages of Particulate
Control Devices. 3-18
3.7 Control Technology Applications for Transfer and
Conveying Sources 3-20
3.8 Control Technology Applications for Loading and
Unloading Operations ...3-21
3.9 Control Technology Applications for Plant Roads 3-21
3.10 Control Technology Applications for Open Storage Piles..... 3-22
3.11 Control Technology Applications for Waste Disposal Sites 3-23
4.2-1 Flammability Characteristics of Combustible
Organic Compounds in Air 4-4
4.2-2 Thermal Incinerator System Design Variables 4-5
4.2-3 Theoretical Combustion Temperatures Required for
99.99 Percent Destruction Efficiencies ....4-5
4.2-4 Comparison of Calculated Values and Values Supplied by
Applicant for Thermal Incineration 4-7
4.2-5 Costs for Thermal Incinerators 4-7
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Tables (continued)
Number Page
4.2-6 Capital Cost Factors for Thermal Incinerators 4-8
4.2-7 Example Case Capital Costs , -. 4-9
4.2-8 Annual Cost Factors for Thermal Incinerators 4-9
4.2-9 Typical Pressure Drops for Thermal Incinerators 4-9
4.3-1 Catalytic Incinerator System Design Variables 4-13
4.3-2 Comparison of Calculated Values and Values Supplied
by the Permit Applicant for Catalytic Incineration 4-16
4.3-3 Equipment Costs for Fixed Bed Catalytic Incinerators ............4-16
4.3-4 Capital Cost Factors for Catalytic Incinerators 4-17
4.3-5 Example Case Capital Costs 4-18
4,3-6 Annual Cost Factors for Catalytic Incinerators 4-19
4.3-7 Typical Pressure Drops for Catalytic Incinerators 4-19
4.4-1 Flare Gas Exit Velocities for 98 Percent Destruction
Efficiency 4-22
4.4-2 Comparison of Calculated Values and Values Supplied
by Permit Applicant for Flares 4-24
4.4-3 Capital Cost Factors for Flares 4-24
4.4-4 Example Case Capital Costs : 4-25
4.4-5 Annual Cost Factors for Flares ..........4-26
4.6-1 Parameters for Selected Adsorption Isotherms ..........4-29
4.6-2 Carbon Adsorber System Efficiency Variables 4-33
4.6-3 Comparison of Calculated Values and Values Supplied
by Permit Applicant for Carbon Adsorption 4-34
4.6-4 Multiplication Cost Factors for Materials .„„................4-35
4.6-5 Installation Factors for Fixed Bed Carbon Adsorbers .......4-35
4.6.6 Example Case Capital Costs . 4-36
4;6.7 Unit Cost Factors for Carbon Adsorption Annual Costs '. 4-37
4.6-8 Selected Equations for Carbon Adsorption Annual
Cost Estimate. 4-38
4.6-9 Comparison of Calculated Values and Values Supplied
by the Permit Applicant for Carbon Canister Systems 4-42
4.6-10 Equipment Costs for Canister Units 4-42
4.7-1 Comparison of Calculated Values and Values Supplied
by the Permit Applicant for Absorption 4-50
4.7-2 Cost of Packing Materials 4-50
4.7-3 Capital Cost Factors for Absorbers .....4-51
4.7-4 Example Case Capital Costs 4-52
4.7-5 Annual Cost Factors for Absorber Systems 4-54
4.8-1 Coolant Selection 4-56
4.8-2 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Condensation 4-60
4.8-3 Capital Cost Factors for Condensers ............4-60
4.8-4 Capital Costs for Refrigerant Systems 4-62
4.8-5 Example Case Capital Costs .......4-63
4.8-6 Annual Cost Factors for Condenser Systems .......4-64
4.9-1 Characteristics of Several Fibers Used in
Fabric Filtration * , 4-67
4.9-2 Comparison of Fabric Filter Bag Cleaning Methods.................. 4-67,
4.9-3 Air-to-Cloth Ratios 4-69
4,9-4 Factors to Obtain Gross Cloth Area from
Net Cloth Area „,.. 4-69
4.9-5 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Fabric Rlters 4-69
XI
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Tables (continued)
Number
4.9-6 Guide to Estimate Costs of Bare Fabric
Filter Systems 4-72
4.9-7 Bag Prices , 4-76
4.9-8 Capital Cost Factors for Fabric Filters ......4-77
4.9-9 Example Case Capital Costs 4-78
4.9-10 Annual Costs for Fabric Filters 4-78
4.10-1 Plate-Wire ESP Drift Velocities ,. 4-83
4.10-2 Wet Plate-Wire ESP Drift Velocities ......4-83
4.10-3 Flat Plate ESP Drift Velocities 4-83
4.10*4 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for ESPs ..4-84
4.10-5 Capital Cost Factors for ESPs... ..4-85
4.10-6 Equipment Cost Multipliers for ESP Optional Equipment ...4-85
4.10-7 Equipment Cost Multipliers for Various
Materials of Construction 4-86
4.10-8 Example Case Capital Costs .4-89
4.10-9 Annual Costs for ESPs 4-89
4.11-1 Pressure Drops for Typical Venturi Scrubber
Applications .4-93
4.11^2 Construction Materials for Typical Venturi Scrubber Applications 4-94
4.11-3 Comparison of Calculated Values and Values
Supplied by the Applicant for Venturi Scrubbers 4-95
4.11-4 Venturi Scrubber Equipment Costs 4-95
4.11-5 Capital Cost Factors for Venturi Scrubbers 4-96
4.11-6 Example Case Capital Costs 4-96
4.11-7 Annual Cost Factors for Venturi Scrubbers 4-97
4.12-1 CE Equipment Index 4-99
4.12-2 Equation 4.12-3 Parameters 4-99
4.12-3 Parameters for Costs of Large Stacks 4-100
B.1-1 Dew Point Temperature (°F) B.1-2
B.1-2 Heats of Combustion and Lower Explosive
Limit (LEL) Data for Selected Compounds B.1-4
B.1-3 Properties of Selected Organic Compounds B.1-4
4.2-4 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for
Thermal Incineration .C.3-4
4.3-2 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Catalytic Incineration C.4-5
4.4-2 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Flares „ .....C.5-3
4.6-3 Comparison of Calculated Values and Values
Supplied by Permit Applicant for Carbon Adsorption C.6-5
4.6-9 Comparison of Calculated Values and Values Supplied by the
Permit Applicant for Carbon Canister Systems C.6-10
4.7-1 Comparison of Calculated Values and Values Supplied
by the Permit Applicant for Absorption C.7-7
C.7-1 Constants for Use in Determining Height of a
Gas Film Transfer Unit ......C.7-10
C.7-2 Constants for Use in Determining Height of a
Liquid Film Transfer Unit C.7-11
C.7-3 Schmidt Numbers for Gases and Vapors in
Air at 77° and 1 ATM ..C.7-12
XII
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Tables (continued)
Number Page
C.7-4 Schmidt Numbers for Compounds in Water at 68°F ..C.7-13
C.7-5 Pressure Drop Constants for Tower Packing C.7-14
C.8-1 Average Specific Heats of Vapors C.8-4
4.8-2 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Condensation .C.8-6
4.9-5 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Fabric Filters C-9.4
4.10:4 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for ESPs.... C.10-2
4.11-3 Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Venturi
Scrubbers '. ...C.11-3
xiii
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Nomenclature
e
e
"def
'dty-cool
a
A/C
A,..
ABS
A
column
Aex
AEC
9f
AF
a.
ASR
Bldg.
b,
c
flame angle for flare, degrees
adsorption cycle time, hr
bed drying and cooling fan operating time, hr
bed drying and cooling time, hr
regeneration cycle time, hr
gas viscosity, Ib/ft-sec
solvent viscosity, centipoise
particle size, aerodynamic mean diameter
packing constant
air to cloth ratio, (ft3/min)/ft2
bed area, ft2
flooding correlation absicca
column area, ft8
condenser surface area, ft2
cyclone inlet area, ft2
ductwork parameter
auxiliary equipment cost, $
annual electricity cost, $
fan parameter
absorption factor
net cloth area, ft2
collection plate area, ft2
stack parameter
annual solvent requirement, gal/yr
gross or total cloth area, ft2
packing constant
ductwork parameter
fan parameter
building cost, $
stack parameter
packing constant
bag costs, $
carbon cost, $
xiv
-------
cc
cw
CE
CEC
CP
cootant
CRC
CRCT
CRF
CRF
C™q
C'
"req
d
D
dc
DAC
DC
column
DE
D
'HAP
D,
Dfp
Dv
Dw
e
EC
catalytic incinerator cost, $
replacement labor cost, $/lb
cooling water cost, $/1,000 gal
collection efficiency, percent
canister equipment cost, $
bag replacement labor, $
mean specific heat of air, Btu/lb-°F
average specific heat of coolant, Btu/lb-°F
specific heat of HAP, BTU/lb-mol °F
cost of replacement bags, $
carbon replacement cost, $
catalyst replacement cost, $
capital recovery factor, decimal fraction
capital recovery factor for bags
capital recovery factor for carbon
amount of carbon required, Ib
amount of carbon required per vessel, Ib
steam cost, $
vessel cost, $
packing constant
density, Ib/ft3
critical particle size, m
direct annual cost, $
direct capital cost, $
column diameter, ft
duct diameter, in
duct diameter, ft
density of emission stream, Ib/ft3
destruction efficiency, percent
density of fuel gas, Ibs/ft3
diameter of fan, in
density of gas stream, Ib/ft3
density of HAP, Ib/ft3
density of liquid, Ib/ft3
particle diameter, u.m
flare tip diameter, in
vessel diameter, ft
densfty of water vapor, Ib/ft3
packing constant
equipment cost, $
xv
-------
f
FC
Fm
Fp
FR
g
G
G.
'del
'-'mol
AH
H
HAPe
HAP,
HAP0
HAP.
H
e,m
o,m
LJ
no neon
hp
HR
HRS
column
* total
IAC
1C
k
flooding fraction
flare cost, $
material cost factor
fan power requirement, kWh/yr
drying and cooling fan flow rate, ft3/hr
packing constant
gas stream flow rate, Ib/hr
gas stream flow rate based on cross-sectional area, lb/ft:i-sec
gas stream flow rate of flooding, Ib/ft2-sec
gravitational constant, ft/sec2
gas stream flow rate, Ib-moles/hr
heat of vaporization, Btu/lb-mole
flare height, ft
moles of HAP condensed, moles/min
HAP emission stream concentration, ppmv
moles of HAP in inlet stream, moles/min
HAP outlet concentration, ppmv
moles of HAP in outlet stream, moles/min
enthalpy change of condensed vapors, Btu/min
emission stream desired heat content, Btu/scf
emission stream heat content, Btu/lb or Btu/scf
supplementary fuel heating value, Btu/lb
flare gas heat content, Btu/scf
height of gas transfer unit, ft
height of liquid transfer unit, ft
condenser heat load, Btu/hr
enthalpy change of noncondensed vapors, Btu/min
height of overall gas transfer unit, ft
horesepower requirement, hp
cooling water horsepower, hp
system fan horsepower, hp
heat recovery in heat exchanger, percent
operating hours per year, hr/yr
stack height, ft
column height, ft
total column heigh, ft
indirect annual cost, $
indirect capital cost, $
empirical parameter
xvi
-------
L = solvent flow rate, Ib/hr
L" = liquid flow rate, per cross-sectional area of column, Ib/hr-ft2
LEL = lower explosive limit, percent
L^, = solvent flow rate, gal/min
Lmol = solvent flow rate, Ib-moles/hr
Lv = vessel length, ft
Lwa m inlet Ib H2O/lb dry air
Lvs = saturated Ib H2O/lb dry air
m = empirical parameter or slope of equilibrium curve
M = molecular weight, Ib/lb-mole
MC = annual maintenance cost, $/yr
Ms = moisture content, percent
^HAP = HAP inlet loading rate, Ib/hr
MWe = molecular weight of the emission stream, Ib/lb-mole
= molecular weight of the flare gas, Ib/lb-mole
» molecular weight of HAP, Ib/lb-mole
= molecular weight of solvent, Ib/lb-mole
n = efficiency, fraction
N = number of beds
NA = number of beds adsorbing
ND = number of beds desorbing
N^ = number of gas transfer units
O2 = emission stream oxygen content, percent
OP = annual ESP operating power, kWh/yr
QRD = flooding correlation ordinate
AP = pressure drop, in, H2O
P = system pressure drop, in. HZO
Pa = pressure drop, Ib/ft2-ft
Pb = pressure drop for carbon adsorbers, in. H2O
P0 = canister system pressure drop, in, H2O
p<«r = cooling water price, $1,000/gal
POP - cost of cyclone, $
= cost of damper, $
= bed cooling and drying fan power, kWh/yr
= power requirement for the fan, kWh/yr
= cost °f two-way diverter valve, $
P, = pressure, mm Hg
PEC = purchased equipment cost, $
P(an = cost of fan system, $
xvii
-------
FRPD
partial
PVCD
ral
it**
Pv
vipor
Q,
Q
e,a
Q'.
Q
:«,ad
Q,
Q,
"118
W.«
Q
p
R
R0
RON
RE
Ref
Rhurn
RTCC
cost of FRP ductwork, $
cost of fan motor and starter, $
power requirement for fabric filters, kWh/yr
pump power requirement, kWh/yr
partial pressure, mm Hg or psia
cost of PVC ductwork, $
cost of rotary air lock for cyclone, $
steam price, $/1,000 Ib
cost of stack, $
pressure drop, in. H2O
venturi scrubber pressure drop, in. HaO
vapor pressure, mm Hg
flow rate of combined gas stream, scfm
coolant flow rate, Ib/hr
cooling water flow rate, gal/min
dilution air required, scfm
emission stream flow rate, scfm
actual emission stream flow rate, acfm
actual emission stream flow rate per adsorbing bed, acfm
actual flow rate of dry air, acfm
saturated emission stream flow rate, acfm
supplementary fuel gas flow rate, scfm
flue gas flow rate, scfm
actual flue gas flow rate, acfm
flare gas flow rate, scfm
actual flare gas flow rate, acfm
liquid flow rate, gal/min
recovered product, Ib/hr or Ib/yr
steam flow rate, Ib/min
volume of water added, ft3/min
packing constant
density of particles in gas stream, Ib/ft3
gas constant
auxiliary equipment cost factor for carbon adsorption
required canister number
removal efficiency, percent
refrigeration capacity, tons
relative humidity, percent
capital cost of refrigerant system, $
xviii
-------
s = packing constant
S = vessel surface area, ft2
SCA = specific collection plate area, ft2/1,000 acfm
ScG = Schmidt number for gas
ScL = Schmidt number for liquid
Sg = specific gravity of fluid
SP = site preparation, $
St = steam regeneration rate, Ib steam/lb carbon
SV = space velocity through catalyst bed, hr -1
T = temperature, °R
ATLM = '°9 mean temperature difference, °F
TAG = total annual cost, $
tb = bed thickness, ft carbon
Te = combustion temperature, °F
TC = thermal incinerator cost, $
TCC = total capital cost, $
Tcl = temperature of gas stream entering catalyst bed, °F
T^ = temperature of flue gas leaving catalyst bed, °F
TMn = temperature of condensation, °F
T^ = inlet coolant temperature, °F
T^^ = outlet coolant temperature, °F
T0 = emission stream temperature, °F
Te s = saturation temperature, °F
Tflg = temperature of flare gas, °F
T^ = temperature of emission stream exiting heat exchanger, °F
tr = residence time, sec
TR = reference temperature, 77° F
U = overall heat transfer coefficient, Btu/hr-ft2-°F
Ud = drift velocity, ft/sec (same as we = migration velocity, ft/sec)
U
-------
Wc = carbon bed working capacity, Ib HAP/lb carbon
W, = carbon bed equilibrium capacity, Ib HAP/lb carbon
WR « water consumption, gal/yr
Y = packing constant
Z - fluid head, ft
xx
-------
Conversion Factors
Quantity
Equivalent Values
Mass
Length
Volume
Force
Pressure
Energy
Power
1kg
"bm
1m
1ft
1m3
= 1000 g = 0.001 metric ton = 2.20462 Ib
= 35.27392 oz.
= 16 oz = 5 x 10-4 ton = 453.593 g = 0.453593 kg
= 100cm = 1000mm=106u,m
1010 angstroms (A) = 39.37 in. = 3.2808 ft
= 1.0936 yards = 0.0006214 mile
= 12 in. = 1/3 yd = 0.3048 m = 30.48 cm
= 1000 liters = 106 cm3 = 106 ml
= 35.3145 ft3 = 220.83 imperial gallons
= 264.17 gallons
= 1056.68 quarts
1 ft3 =1728 in.3 = 7.4805 gallons = 0.028317 m3
= 28,317 liters
= 28,317cm3
1 N = 1 kg m/s2 = 10s dynes = 10s g-cm/s2 = 0.22481 lbf
1 lbf = 32.17 lbm-ft/s2 = 4.4482 N = 4.4482 x 10s dynes
1 atm =1.01325 x 10s N/m2 (Pa), = 1.01325 bars
= 1.01325 x106 dynes/cm1
= 760 mm Hg @ 0°C (torr) = 10.333 m H2O @ 4°C
= 14.696 Ib,/ in.2 (psi) = 33.9 ft H2O @ 4°C
= 29.921 in. Hg @ 0°C
1 J = 1 N m = 107 ergs = 107 dyne-cm
= 2.778 x 10'7 kWh = 0.23901 cal
= 0.7376 ft-lbf = 9.486 x 10"» Btu
1 W = U/s = 0.23901 cal/s = 0.7376 ft-lb./ s
= 9.486 xlO^Btu/s
= 1.341 x10'3hp
Example: The factor to convert grams to pound (mass) is 2.20462 lbm or rj.00220462 Ib
1000g
XXI
-------
Chapter 1
Introduction
1.1 Background and Objective
This manual is a revision of the first (1986) edition of
the Handbook: Control Technologies for Hazardous
Air Pollutants? which incorporated information from
numerous sources into a single, self-contained refer-
ence source focusing on the design and cost of VOC
and paniculate control techniques. However, many of
the references used in the 1986 version were pub-
lished in the mid-to-late 1970's, meaning some infor-
mation in the first edition is somewhat dated. This is
particularly true for the cost data presented in Chapter
51 which were based on 1977 data. Since that time, a
great deal of design and cost information on selected
control techniques has been published, and EPA con-
cluded that this more recent information should be
incorporated into a revised manual. This revision has
been undertaken to incorporate more recent design
and cost information where applicable, while adhering
to the original focus and intent of the 1986 manual.
The objective of this revised manual is described and
the reader is introduced to its overall organization in
the following paragraphs. A corresponding computer
program (HAP PRO, Version 1.0), which performs the
necessary calculations from user input data, is also
available.2
The objective of this handbook is to present a meth-
odology for determining the performance and cost of
air pollution control techniques designed to reduce or
eliminate the emissions of potentially hazardous air
pollutants (HAPs) from industrial/commercial sources.
(Note: The term "hazardous" in this document is very
broad. It is not limited to the specific compounds listed
under current regulations [i.e., the Clean Air Act, the
Resource Conservation and Recovery Act, and the
Toxic Substances Control Act].) This handbook is to
be used by EPA regional, State, and local air pollution
control agency technical personnel for two basic pur-
poses: (1) to respond to inquiries from interested
parties (e.g., prospective permit applicants) regarding
the HAP control requirements that would be needed
at a specified process or facility, and (2) to evaluate/
review permit applications for sources with the poten-
tial to emit HAPs. It should be noted that this docu-
ment provides general technical guidance on controls
and does not provide guidance for compliance with
specific regulatory requirements for hazardous air pol-
lutants. Specifically, ft does not specify design re-
quirements necessary to achieve compliance with stan-
dards established under specific programs such as
Section 112 of the Clean Air Act or standards estab-
lished under the Resource Conservation and Recov-
ery Act. Such requirements vary with the hazardous
air pollutant emitted and with the emission source;
thus, regulatory-specific detailed specifications are be-
yond the scope of this handbook.
The use of this handbook is discussed in Section 1.2.
Chapter 2 assists the user in identifying HAPs and
their respective potential emission sources. Chapter 2
also identifies the key emission stream characteristics
necessary to select appropriate control techniques.
Chapter 3 provides additional information to assist the
user in the control technique selection process for
each HAP emission source/stream. Chapter 4 pre-
sents simple step-by-step procedures to determine
basic design and cost parameters of the specific con-
trol devices and auxiliary equipment. The capital and
annual costs obtained for a given control system re-
flect study-type (±30 percent) estimates in Appendi-
ces A and B. Supplementary data and calculation
procedures are presented. Appendix C contains blank
worksheets to be used while performing the functions
described in this handbook. These worksheets are
masters from which to make copies.
A good source of current information pertaining to
HAPs is the "National Air Toxics Information Clearing-
house," which was established by EPA in response to
State and local agency requests for assistance in the
exchange of information on toxic air pollutants. The
Clearinghouse is operated by EPA's Office of Air
Quality Planning and Standards (OAQPS) in close
coordination with the State and Territorial Air Pollution
Program Administrators (STAPPA) and the Associa-
tion of Local Air Pollution Control Officials (ALAPCO).
Information from State and local agencies is collected
and disseminated at the Clearinghouse, along with
making users aware of air toxics information available
from EPA and other Federal agencies. Specifically,
the following air toxic information is collected from
State and local agencies: regulatory program descrip-
tions, acceptable ambient concentrations on ambient
standards, toxic pollutant research, source permitting,
1-1
-------
ambient monitoring, toxicity testing, and source test-
ing.
The Clearinghouse provides an on-line data base
containing all toxic-related information submitted by
State and local agencies, bibliographic citations for
relevant reports by EPA and other Federal agencies,
and references for ongoing EPA air toxic projects is
provided at the Clearinghouse. A quarterly newsletter
is published also with articles on current air toxics
concerns. Finally, the Clearinghouse periodically pub-
lishes various special reports on topics of interest to
users. For further information regarding the "National
Air Toxics Information Clearinghouse," contact the
appropriate EPA regional office air toxics contact, or
EPA/OAQPS, Pollutant Assessment Branch, MD-12,
Research Triangle Park, North Carolina 27711; (919)
541-5645 or FTS 629-5645.
An additional source of information on potential toxic
pollutants is the Toxic Air Pollutant/Source Crosswalk:
A Screening Tool for Locating Possible Sources Emit-
ting Toxic Air Pollutants, Second Edition, EPA 450/2-
89-017, December 19893. A qualitative indication of
potential toxic pollutants for a given SIC or SCC
process is provided in this document. Some of the
information contained in this source has been used to
update appropriate tables presented in Chapter 2.
This reference utilizes information contained in the
National Air Toxics Information Clearinghouse
(NATICH, mentioned above), the Specific Toxic Chemi-
cal Listings for Title III, Section 313 (SARA Title III),
the Volatile Organic Compound (VOC) Species Data
Manual (2nd edition), and the National Emissions Data
Systems (NEDS) Source classification codes (SCC)
and emission factor listings.
1.2 How to Use the Handbook
Figure 1.1 is a flowchart of the steps performed when
responding to inquiries; Figure 1.2 contains the same
type of flowchart when reviewing permits. As shown
by these figures, these two functions are basically the
same; the only substantive difference is that the re-
view process also compares the determined/calcu-
lated parameters with the corresponding parameters
stated in the permit application to ensure that the
control system(s) proposed by the applicant will pro-
vide the required reduction of HAP emissions.
Once an inquiry or permit application is received,
determine the HAPs applicable to the source category
in question (Section 2.2. The HAPs are categorized
under four headings: organic vapor, organic particu-
late, Inorganic vapor, and inorganic paniculate. (Note:
For each HAP group, a list of potentially or suspected
hazardous compounds that may be emitted as a HAP
from the source category is provided. This listing is
neither all-inclusive nor a declaration that the com-
pounds presented are hazardous.) Next, identify the
potential emission sources for each HAP group (Sec-
tion 2,2), The HAP emission sources are listed under
one of three classifications: process point sources,
process fugitive sources, and area fugitive sources.
(Note: See Section 2.2 for classification definitions.)
After each emission source is determined, identify the
key HAP emission stream characteristics (e.g., HAP
concentration, temperature, flow rate, heat content,
particle size) needed to select the appropriate control
technique(s) (Section 3.2). Obtain the actual values
for these characteristics from the owner/operator or
from available literature if the owner/operator cannot
provide the necessary data. If two or more emission
streams are combined prior to entry into an air pollu-
tion control system, determine the characteristics of
the combined emission stream (Appendix B.1).
Depending upon the specific regulation and the type/
characteristics of the HAP emission source/stream,
the remaining steps in the methodology will differ.
Four basic "formats" for a regulation are: (1) a particu-
lar "control device" may be required, (2) a "numerical
limit" may be specified, (3) a "technology forcing"
requirement may be imposed, and (4) a specific work
practice or "other" related practice may be required.
The regulation format will define the steps that lead to
the selection of the appropriate control technique(s).
The "control device" and "other" formats specify the
appropriate control technique(s). A "numerical limit"
format requires the determination of the HAP removal
efficiency before the appropriate control technique(s)
can be identified. Lastly, the "technology forcing" for-
mat has two paths: one where the cost of the control
system is a factor in the decision, and one where cost
is not a factor. If control system cost is a factor, the
agency must determine the cost constraints that will
be imposed on the control technique selection pro-
cess (e.g. $/ton). The steps that occur in defining the
HAP control requirements will depend upon each
agency's regulatory policies.
The HAP emission stream characteristics, in conjunc-
tion with the limitations imposed by the applicable
regulations, are used to select the appropriate control
techniques (Chapter 3) for each HAP emission source/
stream. General guidelines are provided that match
specific control devices with specified emission stream
properties (e.g., HAP content, temperature, moisture,
heat content, particle size, flow rate). Basic design
parameters are then determined to provide general
design conditions that should be met or exceeded for
each selected control technique to achieve the speci-
fied HAP removal efficiency (Chapter 4). This exercise
also identifies which of the selected control techniques
will not achieve the desired HAP control requirement.
The basic design parameters calculated in Chapter 4
are used to obtain a "study-type" cost estimate for
each control device. The cost algorithm follows the
design variables for each control technique that is
presented in Chapter 4. As noted above, this cost
information can be an integral part of the HAP control
system selection process. After completing the above
process, a HAP control program can be recommended
or evaluated.
1-2
-------
Figure 1,1 Steps used when responding to Inquiries.
Information Requested
on HAP Control for
a Specific Facility
Obtain Available
Plant-Specific Data
Define HAPs1
Define Emission Sources
Generating HAPs1
_L
Define Characteristics
Needed for Each HAP
Emission Stream2
Combine HAP Streams3
Inquirer Assistance
Define Characteristics
Of Combined Streams4
Each Single/Combined A ^
HAP Emission Stream )
Define HAP Control
Requirements6
Control
Device
Select Appropriate
Control Technique(s)*
Numerical Limit
Determine Required
Control Efficiency5
A Technology Forcing
Yes
Are Basic Design
Parameters Requested'
No
,. Yes
Determine Basic Design
Parameters for
Control System(s)7
Is Cost of Control a
Decision Factor ?
No
Agency Determination
of Cost Constraints5
Other
~| Requirement
Regulation Agency
Policy Decision
Select Appropriate
Control Technique(s}8
Select Appropriate
Control Technique(s)6
Determine Basic Design
Parameters for
Control System(s)7
Determine Basic Design
Parameters and Cost for
Control System(sp
Select Control System
Having Most Stringent
Level of Control Within
Given Cost Constraints
Recommend Appropriate
Control technique(s)
Select Control System
Having Most Stringent
Level of Control
BLast HAP
mission Stream?'
No
jTYes
Recommend HAP
Control Program
1-3
-------
Figure 1.2, Steps used whan reviewing permits.
Manua) Uewfen to
Perform Step
'Section 2,2
2,3
'Appendix 6,1
"Chapter $
?Chaptar4:DesJg»
*Chapter 4t Cost
Control
Device i
Select Appropriate
Control Technlque(s)s
Determine Basic Design
Parameters for
Control System(s)7
Is Permit Control
System Appropriate?
Yes
Permit Application
for Review/Approval
Obtain Additional Data
from Applicant
"AreAll HAP EmissiorT^
_§ources AddresseeM?^,.-'
• Yes f1
'A'reAII HAP ErnissJwTx
Stream Characteristics
DrniiMoH29 ^S
. No
\ N° t
; '
Obtain Additional Data
from Applicant
I
Obtain Additional Data
from Applicant
Yes
Emission Steams
Yes
Are Combined Stream
No
Characteristics Correct1?
No
-T
Yes
(
Each Single/Combined^
HAP Emission Stream ~
Define HAP Control
Requirements5
Obtain Additional Data
from Applicant
Technology Forcing
Numerical Limit
Determine Required
Control Efficiency*
Regulatory Agency
Policy Decision*
Other Requirement
Yes/-
Recommend Appropriate
Control Technique(s)
Is Permit System
Design Appropriate?
Recommend Appropriate
Basic Design Parameters
Yes
Is cost of control a
Decision Factor?
Agency Determination
of Cost Constraints5
!
No
Select Appropriate
Control Technique(s)*
Select Appropriate
Control Technique(s)B
Determine Basic Design
Parameters and Cost for
Control System(s)7'
JL
Select Control System
Having Most Stringent
Level of Control Within
Given Cost Constraints
Determine Basic Design
Parameters for
Control System{s)7
Select Control System
Having Most Stringent
Level of Control
Last HAP Emlsstion
Stream?
1
Yes
Permit Approval or
Provide Recommendations
1-4
-------
1.3 References
1. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants, EPA/625/6-86/014 (NTIS
PB 91-228809). Cincinnati, OH. September 1986.
2; U.S. EPA. HAP PRO: Software Program for Con-
trol Technologies for HAP, Control Technology Cen-
ter, Research Triangle Park, NC. June 1991.
3. U.S. EPA. Evaluation of Control Technologies for
Hazardous Air Pollutants, Volume 2. Appendices. EPA/
600/7-86/009b (NTIS PB 86-167038). Research Tri-
angle Park, NC. February 1986.
4. U.S. EPA. Toxic Air Pollutant/Source Crosswalk:
A Screening Tool for Locating Possible Sources Emit-
ting Toxic Air Pollutants, Second Edition. EPA/450/2-
89/017 (NTIS PB 90-170002). Research Triangle Park,
NO, December 1989.
1-5
-------
Chapters
HAP Em/ss/ons by Source Category and Key Physical Properties
2.1 Background
The primary goal of this chapter is to identify the follow-
ing: (1) potential HAPs for a given source category and
the specific sources that may emit the potential HAPs
and (2) key emission stream physical properties needed
to select appropriate control strategies and size control
devices for the HAP emission sources. Specific source
categories are divided into nine general classifications in
this manual. [Note: The general classification system is
a hybrid of the classification systems used in references
6 and 78.] Every possible source category cannot be
listed; however, similarities exist between many catego-
ries. Thus, the user should be able to obtain some
guidance for any specific facility. Common source cat-
egories that are known to emit potential HAPs are pre-
sented in this manual. The tables in this chapter have
been updated to incorporate recent information on addi-
tional potential pollutants for the source categories. Ap-
pendix A.1 contains a list of compounds currently consid-
ered hazardous along with the corresponding CAS num-
ber. While a list of hazardous compounds is provided in
this table, the user should not necessarily use it as a
definitive guide. As discussed in Chapter 1, the term
"HAP'ls broad and encompasses numerous compounds.
This appendix isdesigned to assist in determining HAPs,
rather than act as a definitive list. Other information
sources discussed in Chapter 1 can also be used to
obtain information on HAPs from a given source.
An original intent was to provide the reader with a table
listing potential pollutants on an SIC and SCC basis. In
other words, given a particular SIC or SCC facility, the
potential pollutants expected to be emitted from this
facility would be listed. This table would enable the
reader to target industries or source categories having
the potential to emit a given HAP or HAPs. However,
given the length of this list as presently compiled (over
350 pages) it was decided to instead refer the reader to
Reference 76 to obtain this list. Appendix A.2 gives the
cover page and the first page of this table is listed in
Appendix A.2 so that the reader can be certain he is
referencing the correct document and table.
Individual source categories have been classified based
on the manufacturing process associated with emissions
of potential HAPs. The Solvent Usage Operations
classification includes processes dependent on solvents,
such as surface coating and dry cleaning operations.
Individual HAPs from this category are given in Appendix
A.3. Metallurgical Industries include processes associ-
ated with the manufacture of metals, such as primary
aluminumproduetion.Processesand operations associ-
ated with the manufacture of organic and inorganic
chemicals have been grouped into the Synthetic Organic
and Inorganic Chemical Manufacturing classifications,
respectively. Industries using chemicals in the formula-
tion of products are classified as Chemical Products
Industries. The Mineral and Wood Products Industries
classifications include operations such as asphalt batch
plants and kraft pulp mills, respectively. The Petroleum
Related Industries classification is defined as oil and gas
production, petroleum refining, and basic petrochemi-
cals production. Combustion Sources are utility, indus-
trial, and residential combustion sources using coal, oil,
gas, wood, or waste-derived fuels.
To assist the manual user in recording the pertinent
information, a worksheet has been provided. A copy of
this worksheet, the "HAP Emission Stream Data Form,"
tmmmmwmmm^mmimmsm
is presented in Appendix C.1. An example of a partially
completed worksheet is shown in Figure 2.1. This
worksheet is designed to record information pertaining to
one emission stream, be it a single stream or a combined
stream consisting of several single streams.
2-1
-------
Ftgun Z1. HAP omission atraam data form*
Company:
Location (Street);
(City):
Glaze Chemical Comoanv
87 Octane Drive
Somewhere
Plant Contact
Telephone No:
Mr. John Leaks
(999) 555-5024
(State, Zip):
Contact: Mr, Efrem Johnson
No, of Emission Streams Under Review:
#1 / #3 Oven Exhaust
B.
C,
D.
E,
F.
a
H.
i.
j.
K.
L.
M.
N.
O.
U.
V.
W.
HAP Emission Source
Source Classification
Emission Stream HAPs
HAP Class and Form
HAP Content (1,2,3)'*
HAP Vapor Pressure (1 ,2)
HAP Solubility (1,2)
HAP AdsorpBve Prop. (1,2)
HAP Molecular Weight (1,2)
Molstura Content (1 ,2,3) 2% VO»
Flow Rate (1 ,9,3)" 1 5.000 SCfm
Pressure (1 ?) ' atmospheric,,,,
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(max)
paper coating oven
prpcess point
toluene
organic vapor
960 ppmv
28.4 mm Hg at 77° F
insoluble water
orovided
Halogen/Metals? (1,2) ngne / none
Applte,^ Befl,,.af.n«(=3
Rsqirtred Control Level
Sfilectod Control Mfttiods -
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
P.
Q.
R.
S.
T.
fc>
(cl. — — -
|-f
(cj
fcl •
(Cl
(cl
Organic finrrt«nt (1 )*** 100 pprnv CH*
Heat/O Ointent (1) 4, 1 SCf/80-6 vo!%
Particiifate Contnnt (S)
Particle Mean Diam. (3)
Drift Veiocitv/SO., (3)
The data presented are for an emission stream (single or combined streams) prior to entry into the selected control method(s).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the data on lines C and E.
1 » organic vapor process emission
2 M Inorganic vapor process emission
3 - partioilate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
2.2 Identification of Potential HAPs and
Emission Sources
The purpose of this section is to present general informa-
tion on emissions of potential HAPs by source category.
Within each of the nine general classifications, informa-
tion is presented on the types of potential HAPs that may
be emitted by a particular source category. This informa-
tion includes the names of specific compounds, the clas-
sification of the compounds (i.e., organic or inorganic),
and the form in which these compounds would be emitted
(i.e., vapor or particulate). Owing to process variations,
actual emissions from specific facilities may differ from
the general information presented. Complete identifica-
tion of HAP emissions is best accomplished with assis-
tance from the owner/operator of the facility.
Information on source categories is related to applicable
SIC and SCO codes. Given the numerous SCO codes
applicable to some source categories, the last two digits
of the applicable SCC codes have been designated xx to
make the SCC codes more generic. This indicates that all
specific SCC classifications are included within that des-
ignation. For example, an SCC code designated 4-90-
001-xx would includethefollowing SCC codes:4-90-001-
01, 4-90-001-02, 4-90-001-03, 4-90-001-04, 4-90-001-
05, and 4-90-001-99. This was done to avoid a lengthly list
of SCC codes. In some instances, the SCC code has been
broadened further, with the last five digits (instead of the
last two) being unspecified.
This section also presents information pertaining to the
sources (e.g., processes) within each specific source
category that have the potential to emit HAPs. In this
manual, emission sources are broadly classified into
three groups: process point sources, process fugitive
sources, and area fugitive sources. Point sources are, in
general, individually defined. Reactors, distillation col-
umns, condensers, furnaces, and boilers are typical point
sources which discharge emissions through a vent-pipe
or stack. These sources can be controlled through the use
of add-on control devices. Process fugitive sources, like
process point sources, are individually defined. Emis-
sions from these sources include dust, fumes, or gases
that escape fromorthrough pumps, valves, compressors,
access ports, and feed or discharge openings to a pro-
cess (e.g., the open top of a vapor degreaser). Process
fugitive sources also can include vent fans from rooms or
enclosures containing an emissions source (e.g., a vent
fan on a dry cleaner). These sources can be controlled by
add-on control devices once the emissions are captured
by hooding, enclosures, or closed vent systems and then
transferred to a control device.
Area fugitive sources are characterized by large surface
areas from which emissions occur. Area fugitive sources
2-2
-------
Tab/e 2,1, Potential HAPs and Emission Sources lor Solvent Usage Operations
Source Category
Solvent Degreasing
Dry Cleaning
Graphic Arts*
Waste Solvent Reclaiming
SC'-Flatwood Paneling"
SC-Machlnery*
SC-Appliances'
SC-Metal Furniture
SC-Auto/Truck11
SC-Fabrics
SC-Cansh
SC-Paper, Tapes, Labels
Magnetic Tape Coating
SC-Electrical Insulation
SC-Marine Vessels1
Vinyl & Acrylic Coatings1
SC-Wood Furniture
SC-Trans. Vehicles'-
Machine Lubricants
Rubber Tire Manufacturing
Potential HAPs"
Organic Inorganic
Vapor Particulate Vapor Paniculate
X
X
X
X
X
X X
X X
X X
X X
X
X
X
X
X
X X
X
X
X X
X
X
Potential
Process
Point
A,B,C,D
I.F.Q
F,L,M,N
N
LAP
O,Q,R
OAR
OAR
O.R.S
OAR.T
O,Q,U
O.Q.T
FAT
OA
O,L,P
O.R.S.T
R,S
F
Emission Sources
Process
Fugitive
A.B.D
E,G,H,I
L,M,N
1
L,P
Q,R
Q,R
Q,R
S,R
D.KAR.T
Q,U
B.1AT
IA.T
Q
L,P
S,R,T
R,S
l.V.W
Area
Fugitive
K
I.J.K
J,K
Q
Q
Source Key
A - bath evaporation
B - solvent transfer
C - ventilation
D - waste solvent disposal
E - washer
F - drying
G- still, filtration
1 - solvent storage Q -
J - pipes, flanges, pumps R -
K - transfer areas S -
L - rollers . T -
M - ink fountains U -
N - condenser V -
O - oven W-
application area
flashoff area
spray booth
solvent/coating mixing
quench area
green tire spraying
sidewall/tread end/undertreated cementing
References 2, 3, 4,5, 6, 7, 8, 9,10,11, 13, 26, 27, 76.
Category includes flexography, lithography, offset printing, and texflle printing.
SC: surface coating.
Category includes coating of other flat stock.
Category includes coating of misc. metal parts, machinery, and equipment.
Category includes all categories of appliances: Large and small.
Category includes coating of automobiles and light-duty trucks.
Category includes surface coating of coils, cans, containers, and closures.
Category includes coating and maintenance of marine vessels.
Category includes vinyl, acrylic, and nitrocellulose coatings.
Category Includes coating of trucks, buses, railroad cars, airplanes, etc.
include large and undefined emission sources such as
waste treatment lagoons, raw material storage piles,
roads, etc.
The sources listed in this manual generate emissions;
however, a definitive statement as to whether they emit
a HAP cannot be made. As in the case of identifying the
potential HAPs emitted at a specific facility, communica-
tion with the owner/operator is useful in identifying each
source that emits a HAP. The listings found in this section
are not all-inclusive; a specific facility may have an
emission-producing operation that is not common to its
industry and, thus, the source may not be included here.
2.2.1 Solvent Usage Operations
Solvent usage operations are defined as manufacturing
processes that use solvents, including such processes
as surface coating operations, dry cleaning, solvent
degreasing, waste solvent reclaiming, and graphic arts.
The majority of solvent usage operations falls under SIC
codes 2842, 2865, 2869, 28i9, and 2911; and SCO
codes 4-90-001 -xx, 4-90-900-xx, and 4-90-999-xx. Table
2.1 lists source categories withinthisgroupof operations
that have been identified as sources of volatile organic
compound emissions that may include potential HAPs.
As is shown by Table 2.1, all solvent usage operations
generate organic vapor emissions. [ Note; Some of the
emission sources generate aerosols (i.e., organic par-
ticulate); however, the aerosols evaporate in a short time
and the emissions normally are controlled as a vapor.
Therefore, Table 2.1 does not indicate the presence of
organic particulates.J Due to the large number of poten-
tial HAPs associated with these types of operations, the
format of Table 2.1 prohibits the inclusion of compound-
specific data. Potential HAPs that may be emitted by
sources in Table 2.1 are summarized in Appendix A.3;
this appendix lists both specific compounds and classes
of compounds that may be emitted by sources within the
2-3
-------
Example Case
As directed in Section 2,1*, Appendix A,3 is used to
determine the potential HAPs, The potential HAPs
for paper coating operations are as follow:
Genetic Compounds
rnTneraf spirits
other aromattes
alcohols
celtusoives
ketones
esters
Specific Compounds
toluene
xylene
ethyteneglycot
acetone
methyl ethyl ketone
methyl feObutyl ketone
ethyl acetate
Upon reviewing data from the solvent vendor, the
owner determined that onlyloluenefs present in the
solvent being evaporated by the ovens. Table 2.1
indicates that tolueneis anorganic compound* and
it would be emitted as a vapor. This information is
then listed on the "HAP Emission Stream Data
Form" provided in Appendix C.1 (see Rgure 2,1).
Also for the example case, the source (oven: a
process point source) was identified, if the user
were interested in the other emission-releasing pro-
cesses at a paper coating operation, Table 2.1
indicates that the remaining sou rces include solvent
transfer, solvent storage, application areas, and
solvent/coating mixing.
category. Appendix A.3 can be used to make a prelimi-
nary determination of whether a particular solvent usage
operation may emit a specific potential HAP or group of
potential HAPs, as well as to determine potential solvent
use operations that may emit a particular HAP. Table 2.1
presents the emission sources that may emit potential
HAPs. Note that the same source may be given under a
process point and a fugitive source, to account for differ-
ent facilities.
2.2.2 Metallurgical Industries
The metallurgical industries can be broadly divided into
primary, secondary, and miscellaneous metal produc-
tion operations. The majority of this industry is covered
under SIC Codes 331,332,333,334 and 336 and SCC
codes 3-03-001-xx through 3-03-010-xx and 3-04-001-
xx through 3-04-010-xx. The term "primary metals" refers
to production of the metal from ore. The secondary
metals industry includes the recovery of metal from scrap
and salvage and the production of alloys from ingots. The
miscellaneous subdivision includes industries with op-
erations that produce or use metals for final products.
Table 2.2 contains the potential HAPs for these indus-
tries and the industry-specific emission sources. Given
the array of potential sources, it is best to obtain specific
information must be obtained from the permit applicant
for this source category.
2.2.3 Synthetic Organic Chemical
Manufacturing Industry (SOCMI)
The SOCMI is a large and diverse industry producing
several thousand intermediate and end-product chemi-
cals from a small number of basic chemicals. Most of the
chemicals produced by this industry fall under SIC Code
286. Specific SCC codes forthis source category are too
numerous to list, but most fall under SCC code 3-01 -xxx-
xxx. Due to the complexity of the SOCMI, a general
approach is used in this section to describe generic
emission sources and specific emission source types.
This approach is identical to the approach used by EPA
in its efforts to develop new source performance stan-
dards for the SOCMI.
A large proportion of the emissions from the SOCMI
occur as organic vapors. However, organic paniculate
emissions may be generated in some processes (usually
during the manufacture of chemicals that exist as solids
at ambient conditions). The emissions typically contain
raw materials (including impurities) used in and interme-
diate and final products formed during the manufacturing
process. Many of these emission streams may contain
HAPs due to the great number of compounds manufac-
tured in the SOCMI.
Potential emissions from this industry can be described
generically as follows:
(a) storage and handling emissions,
(b) reactor process emissions,
(c) separation process emissions,
(d) fugitive emissions, and
(e) secondary emissions (e.g., Ifrom waste treatment).
Emissions can potentially occur from raw materials and
product storage tanks as working and breathing losses
through vents. Emissions from handling result during
transportation or transfer of the volatile organic liquids.
Reactor processes and separation processes are the
two broad types of processes used in manufacturing
organic chemicals. Reactor processes involve chemical
reactions that alter the molecular structure of chemical
compounds. A reactor process involves a reactor, or a
reactor in combination with one or more product recovery
devices. Product recovery devices include condensers,
adsorbers, and absorbers. Emissions from reactor pro-
cesses occur predominantly from venting of inert gases
from reactors and product recovery devices, or from the
release of organic compounds that cannot be recovered
economically. Typical emission sources in reactor pro-
cesses include point sources (e.g., vents on reactors and
product recovery devices), process fugitive sources such
as disposal of bottoms from the reactor or the product
recovery devices, and area fugitive sources (e.g., pumps,
valves, sampling lines, and compressors).
Separation processes often follow reactor processes
and divide chemical product mixtures into distinct frac-
2-4
-------
Table 2-2. Potential HAPs and Emission Sources for Metallurgical Industries
Potential HAPs"
Source Category Organic
Vapor PaiUculate
Primary Aluminum ProduoBon
Primary Cadmium Production
Metallurgical Goke 3,8,13,19,21,23, 18
26,27,28,30
Primary Copper Smelting 18
Ferroalloy Production 18
Iron and Steel Production 1 8
Primary Lead Smelng 18
Primary Zinc Smelting 18
Manganese Production 18
.Nickel Production 18
Secondary Aluminum Operations
Secondary Copper Operations 18
{Brass and Bronze Production)
Gray iron Foundries 2,3,13,19,21,23 18
Secondary Lead Smelting 18
Steel Foundries
Secondary Zinc Processing
Lead Acid Battery Production
Cadmium-Nickel Battery Production
Dry Battery Production
Misc. Lead Products
Inorganic
Vapor Particu late
12,32,33 12,32,33
9
4,29 1,5,6,7,9,14,
15,16,17,20,22
1,12,31 1,5,9,11,14,
15,17,20,24
9,10,11,14,16,
17,22,24
12 6,9,10,11,14,
16,17,22,24
1,12 1,5,9,11,14,15,20
* 1,12 1,5,9,11,14,15
20,24
16
1,12 1,9,14,17,20,24
12 12,17
24 9,11,14,17,20,24
1,6,7,9,10,11,14,
15,16,17,22,24,25
^1,14,16,20
1,7,10,11,14,
16,17,24,25,34
24 9,15,17,20,24
14 14
9,14
16
14 5,14
Potential
Process
Point
A,I,J,M,N,R
J,E
B
F,J,T
J
B,J,V
J,V
E.J.T.S
J
A,I,J,M,T
J
J
J,Y
J
J,Y
J,E,S
V
Emission Sources
Process
Fugitive
H.K.D
O.P
c.o.x
G,H,K,O,P,X
H,K,O,P
C,H,K,0,X
H.K.O.P
O
H.K.M.P
P
H.K.P
H.K.P
H,K,G,P
H,K,P
G.H.K.P
H.K.L.P
O,P
N.O
M.N.O
GAP
Area
Fugitive
N,Q,U,Z
N,Z
N.D.Q.U
N,Q,U,W,Z
N.Q.W
D,N,Q,U,W,Z
N,Q,U,W,Z
N,Q,U,W,Z
N.Q.Z
N.Q.Z
U
U
U
U,Q
U
U
Pollutant Key
1 - arsenic
2 - acrolein
3 - acelaldehyde
4 - ammonia
5 - antimony
6 - barium
7 - beryllium
8 - benzene
9 - cadmium
10 - chromium
11 - copper
12 - fluorides
13 - formaldehyde
14 - lead
15 - mercury
16 - manganese
17 - nieke!
18 - polycyclic
organic matter
(POM)
19 - phenol
20 - selenium
21 - toluene
22 - vanadium
23 - xylene
24 - zinc
25 - iron
26 - cresols
27 - cyanides
28 - pyridine
29 - hydrogen sulfide
30 - methyl mercaptan
31 - sulfuric acid
32 - chloride
33 - hydrogen chloride
Source Key
A - calciner
B - coke oven
C - coke oven charging/
pushing
D - coke quenching
E - condenser
F - converter
G - converter/charging etc.
H - furnace tapping
I - furnace material handling
J - furnace
K - furnace charging
L - galvanizing vessel
M - material crusher/mill
N - material storage and
handling
O - material preparation
P - metal casting
R - reduction ceil
S - retort
T - roaster
U - service road
V - sintering machine
w - slag dumping
X - vessel leakage
Y - foundry mold & core
decomposition
Z - mining operations
1 References 6,14,15,16,17,18,19, 20, 21,23,24,25, 28,29,30,76.
2-5
-------
tions. Emissions from separation processes are associ-
ated primarily with absorption, scrubbing, and distillation
operations. Other separation processes that may con-
tribute to emissions include drying, filtration, extraction,
settling, crystallization, quenching, evaporation, ion ex-
change, dilution, and mixing/blending. One of the more
commonly employed separation techniques is distilla-
tion. Depending on the type of distillation system used
(i.e., vacuumor nonvacuum), typical emission points can
include condensers, accumulators, hot wells, steam jet
ejectors, vacuum pumps, and pressure relief valves.
Emission points from a vacuum distillation system are
shown in Figure 2.2.
Although fugitive emissions are listed as a separate
group, they can occur from storage and handling, reactor
processes, and separation processes. Area fugitive
sources include groups of valves, pressure relief de-
vices, pumps and compressors, cooling towers, open-
ended lines, and sampling systems. Process fugitive
sources include hotwells, accumulators, and process
drains from reactors, product recovery devices, and
separation equipment.
Table 2-3. Emission Sources for the SOCMI •
Generic Source Category
Potential Emission Sources (Specific)
Process Process Area
Point Fugitive Fugitive"
Storage and Handling
Reactor Processes
Separation Processes
Fugitives
E,F
F.L
A
G
G,M,N
G,M,N
B.C.D
C,D,H,I,J,K
K
B,C,D.H,I
J,K,M,N,O
Source Key
A - storage, transfer, and
handling
B- spills
C- valves
D- flanges
E - reactors
F - product recovery devices
(absorber, adsorber,
condenser)
G - process drains
H - pumps
I - compressors
J - sampling lines
K - pressure relief devices
L - separation devices
(distillation column,
absorber, crystallizer,
dryer, etc.)
M- hotwell
N - accumulator
O - cooling tower
• References 12, 31, 32, 33, 34, 35 and 77.
b Groups of small point sources (e.g., valves, compressors,
pumps, etc.) at a SOCMI plant are considered as area fugitive
sources in this manual.
Steam
Ejector
Hotwell
Figure 2.2. Potential emission points (shaded) from a vacuum distillation unit
2-6
-------
Table 2.3 presents information on specific emission
points and emission source types for each of the generic
emission source groups. Using this information, the user
can identify the potential emission sources pertaining to
his specific situation. It is recommended that the user
supplement this information with specific source data
given the variability of this source category.
2.2.4 Inorganic Chemical Manufacturing
Industry
This industry includes the manufacture of the basic
inorganic chemicals before they are used in the manuf ac-
ture of other chemical products. Most of the chemicals
produced by this industry fail under SIC Code 281 and
SGC codes 3-01-011-xx, 3-01-012-xx, 3-01-023-xx, 3-
01-032-xx, and 3-01-035-xx through 3-01-039-xx. Po-
tential emissions from these processes may be high, but
because of economic reasons they are usually recov-
ered. In some cases, the manufacturing operation is run
as a closed system, allowing little or no emissions to
escape to the atmosphere. Table 2.4 contains the poten-
tial HAPsand the industry-specific emission sources for
these industries.
2.2.5 Chemical Products Industry
This industry includes the manufacture of chemical prod-
ucts, such as carbon black, synthetic fibers, synthetic
rubber and plastics, which may be used in further manu-
facture. Also included are the manufacture of finished
chemical products for ultimate consumption such as
pharmaceutical, charcoal, soaps and detergents; orprod-
ucts to be used as materials or supplies in other indus-
tries such as paints, pesticides, fertilizers and explo-
sives. Most of the chemical products are covered under
SIC Codes 282, 283, 284; 285, 287 and 28i. Specific
SCC codes for this source category are too numerous to
list. As in other chemical industries, the potential emis-
sions from these processes may be high, but because of
economic necessity they are usually recovered. Table
2.5 contains the potential HAPs and the industry-specific
emission sources for this industry.
2.2.6 Mineral Products Industry
This industry involves the processing and production of
various nonmetallic minerals. The industry includes ce-
ment production, coal cleaning and conversion, glass
and glass fiber manufacture, lime manufacture, phos-
phate rock and taconfte ore processing, as well as
various other manufacturing processes. A majority of this
industry falls under SIC Codes 142,144,145,147,148,
149,321,322,323,324,325, and 327. Applicable SCC
codes generally fall under 3-05-xxx-xx. Table 2.6 con-
tains the potential HAPs and the industry-specific emis-
sion sources for this industry.
2.2.7 Wood Products industry
The wood products industry involves industrial processes
that convert logsto pulp, pulpboard, hardboard, plywood,
particteboard, or related wood products and wood pre-
serving. This industry falls under SIC Codes 242,243,
249, and 261. Specific SCC codes for this source cat-
egory included 3-07-007-xx, 3-07-008-xx, and 3-07-030-
xx. Chemical wood pulping involves the extraction of
cellulose from wood by dissolving the lignin that binds the
cellulose fibers together, the principal processes used in
chemical pulping are the kraft, sulf ite, and neutral sulf ite.
Plywood production involves the manufacturing of wood
panels composed of several thin wood veneers bonded
together with an adhesive. The wood preserving process
is one in which sawn wood products are treated by
injection of chemicals that have fungistatic and insecti-
cidal properties or impart fire resistance. Table 2.7 con-
tains the potential HAPs and the industry-specific emis-
sion sources for this industry.
2.2.8 Petroleum Related Industries
In this manual, the petroleum related industries source
category includes the oil and gas production industry, the
petroleum refining industry, and the basic petrochemi-
cals industry; these industries fall under SIC Codes 13
and 29. SCC codes forthis source category include3-06-
xxx-xx, 3-01-001-xx, 3-01-002-xx, 3-01-004-xx, and 3-
01-888-xx.
The oil and gas production industry includes the following
processes: exploration and site preparation, drilling, crude
processing, natural gas processing, and secondary or
tertiary recovery. The principal products of this industry
are natural gas and crude oil.
The petroleum refining industry involves various pro-
cesses that convert crude oil into more than 2,500
products, including liquefied petroleum gas, gasoline,
kerosene, aviation fuel, diesel fuel, a variety of fuel oils,
lubricating oils, and feedstocks for the petrochemicals
industry. The different processes involved in the petro-
leum refining industry are: crude separation, light hydro-
carbon processing, middle and heavy distillate process-
ing, and residual hydrocarbon processing.
In the basic petrochemicals industry, hydrocarbon
streams from the oil and gas production and petroleum
refining industries are converted into feedstocks for the
organic chemical industry. These feedstocks include ben-
zene, butylenes, cresol and cresylfc acids, ethylene, naph-
thalene, paraffins, propylene, toluene, and xylene. The
main processes used by this industry are separation,
purification, and chemical conversion processes.
Table 2.8 contains the potential HAPs that may be
emitted from these industries. More specific information
is provided in Table 2.9 on potential emissions from the
petroleum refining industry segment of this generic cat-
egory. A large proportion of the emissions occur as
organic vapors; for example, benzene, toluene, and
xylenes are the principal organic vapor emissions. This is
due to the chemical composition of the two starting
materials used in these industries: crude oil and natural
gas. Crude oil is composed chiefly of hydrocarbons
(paraffins, .naphthalenes, and aromatics) with small
amounts of trace elements and organic compounds
containing sulfur, nitrogen, and oxygen. Natural gas is
largely saturated hydrocarbons (mainly methane). The
remainder may include nitrogen, carbon dioxide, hydro-
2-7
-------
Tub/a 2-4, Potential HAPs for Inorganic Chemical Manufacturing Industry
Potential HAPs"
Potential Emission Sources
Source Category
Aluminum chloride
Aluminum fluoride
Ammonia
Ammonium acetate
Ammonium-nitrate, suifate
thtocyanate, formate, tartrate
Ammonium phosphate
Antimony oxide
Arsenlc-dlsulflde, iodide
penlafluorWe, thloarsenate
tribromide, trichloride,
trifluorkto, trfoxide
orthoarsente add
Barium-carbonate, chloride
hydroxide, suifate, sulflde
Beryllium-oxide, hydroxide
Boric acid and Borax
Bromine
Cadmium (pigment) - sulflde
sulfosslenkte, lithopone
Calcium-carbide, arsenate
phosphate
Chlorine
Chlorosulfonic acid
Chromic acid
Chromium-acetate, borides
hatldes, etc.
Chromium (pigment) - oxide
Cobalt - acetate, carbonate
halldes, etc.
Copper suifate
Fluorine
Hydraztne
Hydrochloric add
Hydrofluoric add
Iodine (crude)
Iron chloride
Iron (pigment) - oxide
Lead-arsenate, halfdes
hydroxides, dioxide,
nitrate
Load chromate
Lead (pigments) - oxWe
carbonate, suifate
Manganese dioxide
(Potassium permanganate)
Manganese suifate
Mereury-halides, nitrates,
oxides
Nickei-halldes, nitrates,
oxWes
NIckol Suifate
Nitric add
Phosphoric add
Wet process
Thermal process
Phosphorus
Phosphorus oxychloride
Phosphorus pentasulfide
Phosphorus trichloride
Potassium- bichromate,
chromate
Potassium hydroxide
Sodium arsenate
Sodium carbonate
Sodium chlorate
Sodium chramate-
dlchromata
Sodium hydrosulfide
Inorganic
Vapor
4,10
17
1
1
1
1,17
5
2
8,10
3,17
10
19,34
12
14
17
1,39
10,20
17
10
10,20
40
3
22
24
27
28
10,17,18,30
17
10
29,31
32,10,29
16
10
1
10
16
18
Parti culate
2
6
7
9
15
2
25
11,12
11
11
13
20
38
20
2,21
21
23
23
25
26
26
28
30
29
29
16
25
2
16
Process
Point
X
X
B,D,E
X
C,F,i,L
X
X
H,U
C,E,G,I,L,U
X
X
X
X
H
H.C
X
H
X
X
X
X
X
X
B
B,G
X
X
X
G,L
G,R
G,R
G,L
G,L
X
L
B,H
H.C.W
B,G
X
X
X
X
1
X
H
I.L.V
X
G.I.L.M
X
Process
Fugitive
X
X
K
X
Q
X
X
K,Q,T
N.P.Q.T
X
X
X
X
K,P
K,R
X
K.NAQ
X
X
X
X
X
X
K,R
X
X
X
P,Q
P,Q
P,Q
Q,P,T
Q,P.T
X
P.Q
Q,T
K.N.R
K.N.P.T
K.N.R.T
X
X
X
X
X
K,P
P
X
P.Q
X
Area
Fugitve
J,S
J.S
J
J,S
J,s
J.S
J,S
2-8
-------
Table 2.4. Potential HAPs for Inorganic Chemical Manufacturing Industry (concluded}
Source Category
Sodium-siliconfluoride,
fluoride
Sulfuric add
Sulfur monochteride-
dichloride
Zinc chloride
Zinc chromate (pigment)
Zinc oxide (pigment)
Potential HAPs8
Inorganic
Vapor Paniculate
17 16
33,34 33
10
36,21 21
35
37
Potential
Process
Point
X
A,B,C,H
X
X
X
X
Emission Sources
Process
Fugitive
X
K,R
X
X
X
X
Area
Fugitive
J,S
Pollutant Key
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ammonia
arsenic
arsenic trioxide
aluminum chloride
antimony trioxide
barium salts
beryllium
bromine
boron salts
chlorine
chromium salts
chromic acid mist
cobalt metal fumes
copper sulfate
Source Key
A - converter
B - absorption tower
C - concentrator
D - desulfurizer
E - reformer
F - neutralizer
G - kiln
H - reactor
I - crystallizer
J - compressor and pump seals
15 - cadmium salts
16 - chromates (chromium)
17 - fluorine
18 - hydrogen sulfide
19 - hydrogen chloride
20 - hydrochloric acid
21 - lead
22 - lead chromate
23 - manganese sails
24 - manganese dioxide
25 - mercury
26 - nickel
27 - nickel sulfate
K - storage tank vents
L - dryer
M - leaching tanks
N - filter
O - flakers
P - milling/grinding/crushing
Q - product handling and
packaging
R - cooler (cooling tower,
condenser)
28- nitric acid mist
29 - phosphorus
30 - phosphoric acid mist
31 - phosphorus pentasulfide
32 - phosphorus trichloride
33 - sulfurio acid mist
34 - sulfur trioxide
35 - zinc chromate
36- zinc chloride fumes
37 - zinc oxide fumes
38 - iodine
39- hydrazine
40- iron oxide
S - pressure relief valves
T - raw material unloading
U - purification
V - calclner
W - hotwell
X - no information
" References 6,17,19, 20, 22, 23, 24, 25, 28,36,37, 38, 39,40,41,42,43, 45, 76.
gen sulfide, and helium. Organic and inorganic panicu-
late emissions, such as coke fines or catalyst fines, may
be generated in some processes.
The emission sources within each of the petroleum
related industries are given in Table 2.10. Sources of
potential HAP emissions from the oil and gas production
industry include: blowouts during drilling operations; stor-
age tank breathing and filling losses; wastewater treat-
ment processes; and fugitive leaks in valves, pumps,
pipes, and vessels. In the petroleum refining industry,
potential HAP emission sources include: distillation/frac-
tionating columns, catalytic cracking units, sulfur recov-
ery processes, storage tanks, fugitives, and combustion
units (e.g., process heaters). Fugitive emissions are a
major source of emissions in this industry. Emission
sources in the basic petrochemicals industry are similar
to those from the petroleum refining industry and the
SOCMI (see Section 2.2.3),
2.2.9 Combustion Sources
The fuel combustion industry encompasses a large num-
ber of combustion units generally used to produce elec-
tricity, hot water, and process steam for industrial plants;
or to provide space heating for industrial, commercial, or
residential buildings. The combustion units may differ in
size, configuration, and type of fuel burned. Coal, fuel oil,
and natural gas are the major fossil fuels burned, al-
though other fuels such as wood and various waste (e.g.,
waste oil) or by-product fuels are burned in relatively
small quantities. Industrial applications of both gasoline-
and diesel-powered stationary internal combustion units
such as generators, pumps, and well-drilling equipment
are also included in this category. In general, emissions
from combustion sources tend to be higher in inorganic
HAPs rather than organic HAPs. A scrubber and/or
paniculate control device is often used tor these sources.
This industry falls under SIC code 4911. SCO codes
applicable for this industry include 1-01-xxx-xx, 1-02-
2-9
-------
Tabla 2.5. Potential HAPa and Emission Sources for the Chemical Products Industry
Potential HAPs'
Potential Emission Sources
Source Category
Carbon black
Charcoal
Explosives
Fertilizers
Paint & varnish
Pharmaceutical"
Plastics"
Printing Ink"
Pesticides"
Soap and detergents
Synthetic fibers
Synthetic rubber"
Pollutant Key
1 - arsenic
2 - acroleln
3 - acrylonltrile
4 - acetic acid
5 - boron
6 - barium
7 - beryllium
8 - benzene
9 - cresols
10 - cadmium
11 - chromium
12 - chloroprene
13 - caprolactum
14 - carbon disulfide
15 - carbonyl sulflde
16 - carbon tetrachloride
17 - chloroform
18 - dichlorobenzene
19 - dlmethylformamide
20 - dimethylamlne
21 - ethylene
22 - ethylene dichloride
23 - formaldehyde
24 - hydrogen sulfide
Organic Inorganic Process
Vapor Particulate Vapor
14,15,16.21, 41 1,24,49,56
24,52,53,54,55
4,23,30 41
9,23,42,46, 24,49,67
57,59,60,61,62,64,65
23,26,44,67 49,67
16,22,31,46
3,4,8,16,17,
18,31,34,46,66,68
23,33,35,39
42,50,51.52
2,8,16,27,42
45,46,51,69
2,3.8,9,16,17.18,
20.25,32,36,39,
47,57,66,69
4,8,22,34, 41 1
38,51.69,70
3,8,13,14,19,23,
24,32,38,40,42,46
3,12,18,20,22,23, 41
33,34,35,36,46,49
26 - hydrogen fluoride
27 - ketones
28 - mercury
29 - manganese
30 - methanol
31 - methyl chloroform
(1,1,1 - trichloroethane)
32 - malelc anhydride
33 - butadiene, 1,3
34 - morpholine
35 - methylene chloride
36 - nitrosamines
37 - nickel
38 - perchloroethylene
39 - phosgene
40 - phtalic anhydride
41 - polycydic organic
matter
42 - phenols
43 - selenium
44 - silicontetrafluoride
45 - terpenes
46 - toluene
47 - xylene
48 - zinc
Particulate Point
1,7,10,11, B.H
28,29,37
E
A,C,H
1 D.H, R.S.V
6,28,43,48 N,O
28,58 A,H,U,W
A,P,V
1,10,48,56 Q
1,10,63 A,H,0,X
1,5,56 M,N,O
A,H,J,O,U,V,X,Z
A,H,0,P,X,Z
49 - ammonia
50 - vinyl chloride
51 - toluene diisocyanate
52 - pyridine
53 - acetylene
54 - hydrogen cyanide
55 - benzo(a)pyrent
56 - sulfuric acid
57 - acetaldehyde
58 - aluminum
59 - dinitrophenol,2-4
60 - dinitrotoluene
61 - diethyl phthalate
62 - hexachloroethane
63 - lead
64 - methyl ethyl ketone
65 - nitrobenzene
66 - dichlorophenoxy-
acetic acid, 2,4-
67 - fluorides
68 - acetone
69 - dioxane
70 - methyl methacrylate
Source Key
A - reactor
B - furnace
C - concentrator
Process
Fugitive
G,K,L
K
K,T
J.
G.L
K,L
G
K,L
G,K
Y
D -
-
F -
G -
H -
I -
J -
K -
L -
M -
N -
0 -
P -
Q -
R -
S -
T -
U -
V -
W -
X -
Y -
Z -
Area
Fugitive
I
F
F,l
F,l
I
F
neutralizer
compressor and pump
seals; valves, flanges,
open ended lines,
sampling lines
storage tank vents
dryer
spills
spin cell or bath
product handling,
finishing, and
packaging
raw material transport
and unloading
spray dryer
kettle
mixing tank (blend tank)
polymerization vessel
cooking vessel
prill tower
granulator
screen
distillation
cooler (condenser)
crystallizer
filter
milling/blending/
compounding
flash tank
25 - hexachlorocyclopentadiene
• References 6, 18, 19, 28.
44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 76,
77.
" Number of compounds prevents complete listing here. See Reference 76 for a more complete list.
2-10
-------
Table 2.6. Potential HAPs for the Mineral Products Industry
Source Category Organic
Potential
Vapor Particulate
Asbestos products 8, 1 3,30,31 ,
32,33,34
Asphalt batching plants 2,8,13
Brick, ceramic, and related
clay products
Refractories
Cement manufacture
Coal cleaning (dry)
Coal cleaning (wet)
'
Coal conversion 8,19,27,28
Glass fiber manufacturing 13,19
Frit manufacturing
Glass manufacturing
Lime manufacturing
Mercury ore processing
Mineral wool manufacturing 12,13,19,
31,36,37
Perlite manufacturing
Phosphate rock processing
Taconite ore processing
Pollutant Key
1 - arsenic
2 - aldehydes
3 - asbestos
4 - ammonia
5 - antimony
6 - barium
7 - beryllium
8 - benzene
9 - cadmium
10 - chromium
11 - copper
12 -fluoride
13 - formaldehyde
14 - lead
15 - mercury
16 - manganese
17 - nickel
18 - polycyclic organic matter (POM)
19 - phenols
18
18
18
19
20 -
21-
22-
23-
24-
25-
26-
27-
28-
30-
31-
32-
33-
34-
35-
36-
37-
HAPs-
Inorganic
Vapor Particulate
23 3,10,11,17
7,10,12, 7,10,12
21,26,35
10,12 10,12
10,12,17,23 7,9,10,14,
15,17,24,25
22
1,5,6,7,9,10,11,14,
16,17,20,21,24
4,23 1,5,7,9,14,16,
17,20,29
6,20,22
12 12
1,4,12,14,26 1,5,6,12,14,
20,21
15 15
15 15
4,12,23 6
12 12
6,20,21 6,20,21
3
selenium
boron
coal dust
hydrogen sulfide
zinc
iron
chlorine
cresols
toluene
isopropanol
methanol
methyl ethyl
ketone
methyl chloroform
xylene
hydrogen fluoride
acetone
carbon tetrachloride
Potential Emission Sources
Process Process Area
Point Fugitive Fugitive
D.N I,L
B F,J,M 1
B.E.C D.F.N I,L
B,E P.F.N 1
E F.G.N.S I.L
M,N,R I,L
B,C M,N I.L
B.H F,G,M,N I.L
C,O D,F,G,N,P 1
B,C S I,L
C D.F.M.N 1
E.T G,R,S I.L
C G,N I.L |
C,O D,G,P I.L
B,C G.M.N.S I.L
A,B,Q F,M,N,R I.L
C.Q F,M,N,R I.L
Source Key
A - calciner
B - dryer
C - furnace
D - end-product forming and finishing
E - kiln
F - raw material preparation/mixing
G - cooling
H - reactor
1 - storage pile
J - saturator
L - mining operations
M - raw material
handling/transport
N - raw material
crusher/mill
O - oven
P - resin application
Q - washers
R - screening
S - end-product handling/grinding/bagging
T - hydrator
• References 6, 17, IB, 19, 20, 21, 22, 23, 24, 29, 33, 4O, 41, 57, 58, 59, 60, 61, 62, 63, 64, 65, 76, 77.
2-11
-------
Tabla 2.7. Potential HAPs tor the Wood Products Industry
Potential HAPs'
Potential Emission Sources
Source Category
Organic
Vapor Paniculate
Chemical wood pulping
Kraft pulp mill
Sulfito pulp mill
Neutral sulfite pulp mill
Plywood, partteteboard, and
hardboard
Wood preservative
!
h
h,l,o,p
j,S,m,n
e
e
e
Inorganic
Vapor Paniculate
k
f,k
k
a,b,c,d
a,b,c,d
a.c.d
Process
Point
A,B,C,D
A.B.C
A.C.E
G
Process
Fugitive
F
F
Area
Fugitive
Pollutant Key
Source Key
a
b
c
d
e
f
g
h
- arsenic
- asbestos
- chromium
- mercury
- polycydic organic
matter (POM)
- chlorine
- chlorobenzene
- formaldehyde
1 -
j -
k -
1 -
m -
n -
o -
P -
methyl mercaptan
dioxin
hydrogen sulflde
phenol
pentachiorophenol
cresols
abielic acid
pinsne
A -
B -
C -
D -
E -
F -
G -
recovery furnace
digester
blow tank
lime kiln
fluidized bed reactor
resin and/or adhesive application
dryer
• References 4,18,19,28.49,50, 76,77.
Table 2.8. Potential HAPa for Petroleum Related Industries'
(General Listing for Entire Source Category)
Potential HAPs
Vapor
Inorganic
Partial late vapor
Organic
paniculate
Paraffins (0,-C,,,) Coke lines
Cydoparafflns (Ce-Cs)
Aromatics (e.g., benzene,
toluene, xytene)
Phenols
Sulfur containing compounds
(e.g., mercaptans,
thtophenes)
Sulfides
(e.g., hydrogen
sulflde, carbon
disulfide, carbonyl
sulflde)
Ammonia
Catalyst fines
« References 21,68,69, 70, 71,72, and 76.
xxx-xx, 1 -03-xxx-xx, 1 -05-xxx-xx, 2-01 -xxx-xx, 2-02-xxx-
xx, 2-03-xxx-xx, and 2-04-xxx-xx.
The waste incineration category includes combustion
processes whereby municipal solid wastes or sewage
treatment sludges are disposed. Table 2.11 contains the
potential HAPs and the facility-specific emission sources
for these source types.
2.3 Identification of Key Emission
Stream Properties .
The emission stream physical properties needed to
select the appropriate control technique(s) and to size
the control device(s) for each identified HAP emission
stream generated by a process source are identified in
this section, be it either a process point source or a
process fugitive source. Design and costing techniques
for area fugitive emission control methodologies are
outside the scope of this manual due to budget consider-
ations; however, control techniques for vapor emissions
and paniculate emissions from area fugitive sources are
discussed in Sections 3.1 A and 3.2.2, respectively.
The actual/estimated values for the process emission
stream properties should be obtained from the owner/
operator orfrom available literature if the owner/operator
cannot supply the necessary data. The values obtained
are used in conjunction with the guidelines given in
Chapter 3 to perform the control technique selection
process. Table 2.12 lists the required information for
organic vapor emissions, Table 2.13 for inorganic vapor
emissions, and Table 2.14 for paniculate emissions.
After obtaining the values for the key physical properties
for each HAP emission stream, record the data on the
"HAP Emission Stream Data Form" found in Appendix
C.1 (see Figure 2.1). Calculation procedures for deter-
mining the heat content of an emission stream are given
in Appendix B.1.
Occasions will occur when the owner/operator should
combine similar emission streams. For example, if two or
more emission streams require the use of the same
control technique, the more cost effective approach is to
combine the streams and use just one control device as
opposed to using a control device for each separate
emission stream. If the owner/operator decides to com-
bine emission streams, calculation procedures are pro-
vided in Appendix B.1 to determine the key effluent
properties of combined emission streams.
2-12
-------
Table 2.9. FotonfM HAPs tor Petroleum Refining Industries** (Specific Listing for Petroleum Refining Segment)
Potential HAPs
Process
Organic
Vapor
Participate
Vapor
Inorganic
Paniculate
Crude separation
Light hydrocarbon processing
a,b,d,e,f,g,h,i,j,k,i,m,o,
A,BIC,D,E,F,J
g,h,i,n,N,O,P
_c,m,t,u,v,x,y,L
t,v
P.IAR
G,H,Q
Middle and heavy
distillate processing
Residual hydrocarbon processing
Auxiliary processes
a.d.e.f.g.h.ij.k.l, o,R
F, J,K.O,P,S,T
a,d,e,f,g,h,i,j,k,l,n, o,R
F,J,M,N,P,S,T
a(b,d,e,f,g,h,i,j,k,l.n, o,R
A,B,C,D,J,K,M,T
m,t,u,v,x,y,L
m,s,t,u,v,x,y,L
c,m,s,u,y»L
p,q,G,H,l,Q;U
p,q,G,H,l,Q,U
P,q,r,z,l
Pollutant Key
a
b
c
d
e
f
g
h
i
j
k
- rnaleic anhydride
- benzole acid
- chlorides
- ketones
- aldehydes
- hetorocyclic
compounds (e.g.,
pyridines)
- benzene
- toluene
- xylene
- phenols
- organic compounds
containing sulfur
(sulfonates,
sulfones)
I
m
n
o
P
q
r
s
t
u
V
X
- cresols
- inorganic
sulfides
- mercaptans
- polynuclear
compounds (benzo-
pyrene, anthracene,
etc.)
-vanadium
- nickel
- lead
- sulfuric add
- hydrogen sulfide
- ammonia
- carbon disuifide
- carbonyl sulfide
y .
* 7 •«
A-
B-
,C-
D-
E -
F .
G-
H-
I -
J -
K-
L -
M-
cyanides
chromates
acetic acid
formic acid
methylethylamine
diethylamine
thiosulfide
methyl mercaptan
cobalt
molybdenum
zinc
cresylic acid
xylenols
thiophenes
ttiiophenol
N-
0-
P -
Q-
R -
S -
T -
U -
nickel carbonyl
tetraethyl lead
cobalt carbonyl
catalyst fines
coke fines
formaldehyde
aromatic amines
copper
* Source: Reference 21.
* Reference 76 contains additional HAP Information for this Industry.
Tabla 2.10, Emission Sources for the Petroleum Related Industries
Potential HAP Emission Sources
Source Category
Process
Point
Process
Fugitive
Area
Fugitive
Oil and Gas Production
Exploration, site preparation and drilling
Crude processing
A
G
C
F,H
D,E
Natural Gas processing
Secondary and tertiary recovery techniques
Petroleum Refining Industry
Crude separation
Light hydrocarbon processing
Middle and heavy distillate processing
Residual hydrocarbon processing
Auxiliary processes
Basic Petrochemicals Industry
Olefins production
Butadiene production
Benzene/toluene/xylene (BTX) production
Naphthalene production
Cresol/cresyiic acids production
Normal paraffin production
G.J.K
G
G.J.L
O,G
G,O,P,R
B,G,K,O,R
G
G,K,O
G,J,L,O,R
G,K,O,R
G,L,O
G,L
G.O
H
F,H,M,N
F,H C
- F,H
H
F,H
F,H .
F.H.N
F.Q
F,H
F,H
F,H
•
-
!
Source Key
A-blowout during drilling
B-visbreaker furnace
C-cuttings
D-drilling fluid
E - pipe leaks (due to corrosion)
F - wastewater disposal (process
drain, blowdown, cooling water
G- flare, incinerator, process
heater, boiler
H- storage, transfer, and handling
I - pumps, valves, compressors,
fittings, etc.
J - absorber
K-process vent
L - distillation/fractionation
M - hotwells
N - steam ejectors
O - catalyst regeneration
P - evaporation
Q - catalytic cracker
R - stripper
2-13
-------
Ttbl» 2.11. Potential HAPa and Emission Sources for Combustion Sources
Source Category
Vapor
Organic
Potential HAPs-
Potential Emission Sources
Paniculate
Vapor
Inorganic
Parti culate
Process
Point
Process
Fugitive
Area
Fugitive
Coal combustion
OH combustion
3,14,19,
21,28,28
14
19
19
1,2,8,9,13, 1,2,5,6,8,9,
17,27,31 10,11,15,16,
18,20,22,24
A,B
13,17,27 1,2,5,6,8,9, A.B.E
10,11,15,16,29
Natural gas combustion
Gasoline combustion
Dfesel combustion
Wood combustion
Waste oil combustion
Municipal refuse incineration
Sewage sludge incineration
PCB Incineration
Pollutant Kay
14
12,14
12
3,4,12,14,25
7,12,21,23,26
12
12
12,21
19
12,19
12,19
12,19
12,19
12,19
12,19
12,19
17 15
6,18
27 16,20
6,8,9,15,18
17,27 6,8,9,11,
15,16,18
17 1,6,8,9,15,16,18
30
A,B,E,F
G
Q
A,B,C
A.B.D
D
D
D,B
Source Key
1 - arsenic
2 - antimony
3 - acotaldohyde
4 - acetic acid
5 - barium
6 - beryllium
7 - benzene
8 - cadmium
9 - chromium
10 - cobalt
11 - copper
12 - dtoxin
13 - fluorides
14 - formaldehyde
15 - lead
16 - manganese
17 - mercury
18 - nickel
19 - polycycllc organic mater (POM)
20 - phosphorus
21 - polychlorinated biphenyls (PCB)
22 - radionuclides
23 - trtchioroethylene
24 - zinc
25 - phenols
. 26 - ethyl benzene
27 - chlorine
28 - pyridine
29 - vanadium
30 - dibenzofuran
A - furnace
B - boiler
C - woodstove/flreplace
D - incinerator
E - gas turbine
F - reciprocating engine
G - industrial engine and/or equipment
H - coal storage pile
I - ash handling system
• References 6,16,17,18,19, 20, 21, 22, 23, 24,25, 28, 29, 30, 31,46,65, 72, 74, 75, 76.
2.4 References
1, U.S. EPA. Evaluation of Control Technologies
for Hazardous Air Pollutants, Volume 2, Appen-
dices. EPA-600/7-86-009b (NTISPB86-167/
038/AS). February 1986.
2, National Paint and Coatings Association. Section
III: Paint and Coatings Markets. Table A-6. Esti-
mated Consumption of Solvents in Paints and
Coatings, by Market -1981. pp. 208-209. (no
date).
3. U.S. EPA. Organic Solvent Cleaners - Back-
ground Information for Proposed Standard.
EPA-450/2-78-045a(NTIS PB80-137912). Oc-
tober 1979.
4. U.S. EPA. End Use of Solvents Containing Vola-
tile Organic Compounds. EPA-450/3-79-032
(NTIS PB80-124423). May 1979.
8.
U.S. EPA. Source Assessment: Solvent
Evaporation - Degreasing Operations. EPA-
600/2-79-019! (NTIS PB80-128812). August
1979.
U.S. EPA. Compilation of Air Pollutant Emission
Factors, Fourth Edition, AP-42, and Supplements,
September 1985. (NTIS PB86-124906).
U.S. EPA. Guidance for Lowest Achievable
Emission Rates for 18 Major Stationary Sources
of Particulates, Nitrogen Oxides, Sulfur Dioxide,
or Volatile Organic Compounds. EPA-450/3-79-
024 (NTIS PB80-140262). April 1979.
U.S. EPA. Control of Volatile Organic Emissions
from Existing Stationary Sources - Vol. VI: Sur-
2-14
-------
Table 2.12. Key Properties tor Organic Vapor Emissions
Teblo 2.13. Key Properties for Inorganic Vapor Emissfons
Emission Stream Properties
(Preferred units of measure)
HAP Properties'
Emission Stream Properties
(preferred units of measure)
HAP Properties"
HAP content (ppm by volume)
Organic contentb (ppm by volume)
Heat contentc (Btu/scf)
Oxygen content (% by volume)
Moisture content (% by volume)
Halogen/metal content (yes or no)
Flow rate (sclrn)
Temperature (°F)
Pressure (mm Hg)
Molecular weight
Vapor pressure
Solubility (graph)
Adsorptive properties
(isotherm plot)
These properties pertain to the specific HAP or mixture of HAPs In the
emission stream.
Primary properties that affect control technique selection. Organic content
Is defined as organic emission stream combustibles less HAP emission
stream combustibles.
Heat content is determined from HAP/Organlc Content (see Appendix B.1
for calculaUonal procedures).
face Coating of Miscellaneous Metal Parts and
Products. EPA-450/2-78-015 (NTIS PB286157).
June 1978.
9. U.S. EPA. Control of Volatile Organic Emissions
from Existing Stationary Sources - Volume II:
Surface Coating of Cans, Coils, Paper, Fabrics,
Automobiles, and Light Duty Trucks. EPA-450/
2-77-008 (NTIS PB272445). May 1977.
10. U.S. EPA. Control of Volatile Organic Compound
Emissions from Large Petroleum Dry Cleaners.
EPA-450/3-82-009 (NTIS PB83-124875). Sep-
tember 1982.
11. U.S. EPA. Pressure Sensitive Tape and Label
Surface Coating Industry - Background informa-
tion for Proposed Standards. EPA-450/3-80-
003a (NTIS PB81-10594270). September 1980.
12. U.S. EPA. Hazardous/Toxic Air Pollutant Control
Technology: A Literature Review. EPA-600/2-
84-194 (NTIS PB85-137/107). December 1984.
13. U.S. EPA. Flexible Vinyl Coating and Printing
Operations - Background Information for Pro-
posed Standards. EPA-450/3-81 -016a (NTIS
PB83-169136). January 1983.
14. U.S. EPA. Background information for New
Source Performance Standards: Primary Cop-
per, Zinc, and Lead Smelters - Volume 1: Pro-
posed Standards. EPA-450/2-74-002a (NTIS
PB237832). October 1974.
15. U.S. EPA. Background Information for Stan-
dards of Performance: Electric Submerged Arc
Furnaces for Production of Ferroalloys - Volume
1: Proposed Standards. EPA-450/2-74-018a
(NTIS PB237411). October 1974.
HAP content" (ppm by volume)
Moisture content (% by volume)
Halogen/mete) content (yes or no)
Flow rate (sclrn)
Temperature (°F).
Pressure (mm Hg)
Molecular weight
Vapor pressure
Solubility (graph)
Adsorptive properties
(isotherm plot)
* These properties pertain to tie specific HAP or mixture of HAPs In the
emission stream. . •
b Primary properties that affect control technique selection.
Tab/9 2.14. Key Properties tor Particular Emissions
Emission Stream Properties HAP Properties*
(preferred unite of measure)
HAP content (% by mass)
Paniculate contentb (gr/dscf)
Moisture content (% by volume)
SO3 content (ppm by volume)
Flow rate (acfm)
Temperature (°F)
Particle mean diameterc (fun)
Particle size distribution**
Drift velocity* (ft/sec)
Particle resistivity"* (ohm-cm)
(None)
* Theso properties pertain to fl» specific HAP or mixture of HAPs In the
emission stream.
11 Data Include total paniculate loading and principle paniculate constituent.
c These properties are necessary only for specific control techniques.
* Some sources may not have this Information.
16. U.S. EPA. A Method for Characterization and
Quantification of Fugitive Lead Emissions from
Secondary Lead Smelters, Ferroalloy Plants, and
Gray Iron Foundries. EPA-450/3-78-003 (NTIS
PB289885). January 1978.
17. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Chromium. EPA-450/4-84-007g
(NTIS PB85-106474). July 1984.
18. U.S. EPA. A Survey of Emissions and Controls
for Hazardous and Other Pollutants. EPA-R4-73-
021 (NTIS PB223568). February 1973.
19. U.S. EPA. Source Assessment: Noncriteria Pol-
lutant Emissions (1978 Update). EPA-600/2-78-
004t (NTIS PB291747). July 1978.
20.
21.
U.S. EPA. Locating and Estimating Air Emissions
from Sources of Nickel. EPA-450/4-84-007f (NTIS
PB84-210988).March 1984.
U.S. EPA. Potentially Hazardous Emissions from
the Extraction and Processing of Coal and Oil.
EPA-650/2-75-038 (NTIS PB241803). April 1975.
2-15
-------
22, U.S. EPA. Review of National Emission Stan-
dardsfor Mercury. EPA45Q/3-84014 (NTIS PB85-
153906). Deoente1984.
23. U.S. EPA. Status Assessment of Toxic Chemi-
cals: Lead. EPA-600/2-79-210H (NTIS PB80-
146376).Deeember 1979.
24. U.S. EPA. Status Assessment of Toxic Chemi-
cals: Mercury. EPA-600/2-79-210! (NTIS PB80-
146384). December 1979.
25. U.S. EPA. Sources of Copper Air Emissions.
EPA-600/2-85-046 (NTIS PB85-191138). April
1985.
26. U.S. EPA. The Use and Fate of Lubricants,
Oils, Greases and Hydraulic Fluids in The Iron
and Steel Industry. EPA-600/2-78-101 (NTIS
PB284973). May 1978.
27. U.S. EPA. Rubber Tire Manufacturing Industry -
Background Information for Proposed Standards.
EPA-450/3-81-0083 (NTIS PB83-163543). July
1981.
28. U.S. EPA. Human Exposure to Atmospheric
Concentrations of Selected Chemicals Vols. 1 &
2. EPA Contract No. 68-02-3066 (NTIS PB81 -
193252 and 193260). February 1982.
29. U.S. EPA. Survey of Cadmium Emission Sources.
EPA-450/3-81-013 (NTIS PB82-142050). Sep-
tember 1981.
30. U.S. EPA. Source Category Survey: Secondary
Zinc Smelting and Refinery Industry. EPA-450/3-
80-012 (NTIS PB80-191604). May 1980.
31. U.S. EPA. Air Oxidation Processes in Synthetic
Organic Chemical Manufacturing Industry -
Background Information for Proposed Standards.
EPA-450/3-82-001 a (NTIS PB84-114834). Octo-
ber 1983.
32. U.S. EPA. VOC Emissions from Volatile Organic
Liquid Storage Tanks - Background Information
for Proposed Standards. EPA-450/3-81-003a
(NTIS PB84-237320). July 1984.
33. U.S. EPA. VOC Fugitive Emissions in Synthetic
Organic Chemicals Manufacturing Industry -
Background Information for Promulgated Stan-
dards. EPA-450/3-80-033b (NTIS PB84-105311).
June 1982.
34. U.S. EPA. Distillation Operations in Synthetic
Organic Chemical Manufacturing - Background
Information for Proposed Standards. EPA-450/
3-83-005a (NTIS PB84-214006). December 1983.
35. U.S. EPA. Organic Chemical Manufacturing Vol-
ume 6: Selected Processes. EPA-450/3-80-028a
(NTIS PB81-220550). December 1980.
36. U.S. EPA. Source Category: Ammonia Manu-
facturing Industry. EPA-450/3-80-014 (NTIS
PB81 -113912). August 1980.
37. U.S. EPA. Source Assessment: Ammonium Ni-
trate Production. EPA-600/2-77-107J (NTIS
PB271984). September 1977.
38. U.S. EPA. Ammonium Sulfate Manufacture -
Background Information for Proposed Standards.
EPA-450/3-79-034a(NTlS PB80-140163). De-
cember 1979.
39. U.S. EPA. Preliminary Study of Sources of Inor-
ganic Arsenic. EPA-450/5-82-005 (NTIS PB83-
153528). August 1982.
40. U.S. EPA. Source Assessment: Major Barium
Chemicals. EPA-600/2-78-004b (NTIS
PB280756). March 1978.
41. U.S. EPA. Emission Factore for Trace Sub-
stances. EPA-450/2-73-001 (NTIS PB230894).
December 1973.
42. U.S. EPA. Review of New Source Performance
Standards for Nitric Acid Plants. EPA-450/3-84-
011 (NTIS PB84-185206). April 1984.
43. U.S. EPA. Sodium Carbonate Industry - Back-
ground Information for Proposed Standards. EPA-
450/3-80-0298 (NTIS PB80-219678). August 1980.
44. U.S. EPA. Industrial Process Profiles for Envi-
ronmental Use: Sulfur, Sulfur Oxides and Sulfuric
Acid. EPA-600/2-77-023W (NTIS PB281490) Feb-
ruary 1977.
45. U.S. EPA. Final Guideline Document: Control of
Sulfuric Acid Mist Emissions from Sulfuric Acid
Production Plants. EPA-450/2-77-019(NTIS
PB274085) September 1977.
46. U.S. EPA. Source Assessment: Charcoal
Manufacturing. EPA-600/2-78-004z (NTIS
PB290125). December 1978.
47. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Formaldehyde. EPA-450/4-84-
007e (NTIS PB84-200633). March 1984.
48. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Chloroform. EPA-450/4-84-007c.
(NTIS PB84-200617). March 1984.
2-16
-------
49. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Carbon Tetrachloride. EPA-450/
4-84-OOTb (NTIS PB84-200625). March 1984.
50. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Chtorobenzenes.EPA-450/4-84-
007{NTIS PB87-189841). September 1986.
51. U.S. EPA. Plastics and Resins Industry - Indus-
trial Process Profiles for Environmental Use, Chap.
10. EPA-600/2-77-023J {NTIS PB291640). Feb-
ruary 1977.
52. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Phosgene. EPA-450/4-84-007I
(NTIS PB86-117595). September 1985.
§3. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Acrytonftrile. EPA-450/4-84-007a
(NTIS PB84-200609). March 1984.
54. U.S. EPA. Locating and Estimating Air Emissions
from Sources of Ethylene Dichloride. EPA-450/4-
84-007d (NTIS PB84-239193). March 1984.
55. U.S. EPA. Asphalt Roofing Manufacturing Indus-
try - Background Information for Proposed Stan-
dards. EPA-450/3-80-021 a (NTIS PB80-
212111). June 1980.
56. U.S. EPA. Trace Pollutant Emissions from the
Processing of Nonmetallic Ores. EPA-650/2-74-
122 (NTIS PB240117). November 1974.
57. U.S. EPA. Source Category Survey: Refractory
industry. EPA-450/3-80-006 (NTIS PB81-
111445). March 1980.
58. U.S. EPA. A Review of Standards of Performance
for New Stationary Sources - Portland Cement
Industry. EPA-450/3-79-012 (NTIS PB80-
112089). March 1979.
59. U.S. EPA. Background Information for Standards
of Performance: Coal Preparation Plants Volume
I: Proposed Standards. EPA-450/2-74-021 a (NTIS
PB237421). October 1974.
60. U.S. EPA. Glass Manufacturing Plants, Back-
ground Information: Proposed Standards
of Performance .Volume I. EPA-45Q/3-79-005a
(NTIS PB298528). June 1979.
61. U.S. EPA. Wool Fiberglass Insulation Manufac-
turing Industry - Background Information for Pro-
posed Standards. EPA-450/3-83-002a (NTIS
PB84-156264).December 1983.
62. U.S. EPA. Standards Support and Environmen-
tal Impact Statement Volume I: Proposed Stan-
dards of Performance for Lime Manufacturing
Plants. EPA-450/2-77-007a (NTIS PB266942).
April 1977.
63. U.S. EPA. Final Standards Support and Envi-
ronmental Impact Statement Volume II: Promul-
gated Standards of Performance for Lime Manu-
facturing Plants. EPA-450/2-77-007b (NTIS
PB80-194491). October 1977.
64. U.S. EPA. Source Category Survey: Mineral
Wool Manufacturing Industry. EPA-450/3-80-
016 (NTIS PB80-202781). March 1980.
65. U.S. EPA. Source Category Survey: Perlfte In-
dustry. EPA-450/3-80-005 (NTIS PB80-194822).
May 1980.
66. U.S. EPA. Radionuclides - Background Infor-
mation Document for Final Rules. Volume I.
EPA-520/1-84-022-1 (NTIS PB85-165751).
October 1984.
67. U.S. EPA. Kraft Pulping - Control of TRS Emis-
sions from Existing Mills. EPA-450/2-78-003b.
(NTIS PB296135). March 1979.
68. U.S. EPA. Industrial Process Profiles for Envi-
ronmental Use: Chapter 2. Oil and Gas Produc-
tion Industry. EPA-600/2-77-023b (NTIS
PB291639), February 1977.
69. U.S. EPA. Industrial Process Profiles for Envi-
ronmental Use: Chapter 3. Petroleum Refining
Industry. EPA-600/2-77-023C (NTIS PB273649).
January 1977.
70. U.S. EPA. Industrial Process Profiles for Envi-
ronmental Use: Chapter 5. Basic Petrochemi-
cals Industry. EPA-600/2-77-023e (NTIS
PB266224). January 1977.
71. U.S. EPA. VOC Fugitive Emissions in Petroleum
Refining Industry—Background Information for
Proposed Standards. EPA-450/3-81-Q15a. Re-
search Triangle Park, NC. November 1982.
72. U.S. EPA. VOC Species Data Manual, Second
Edition. EPA-450/4-80-015. July 1980. (NTIS
PB81-119455).
73. U.S. EPA. Bulk Gasoline Terminals - Back-
ground Information for Proposed Standards
(Draft). EPA-450/3-80-038a (NTIS PB82-
152869). December 1980.
74. U.S. EPA. Hazardous Emission Characteriza-
tion of Utility Boilers. EPA-650/2-75-066 (NTIS
PB245017).July1975.
75. U.S. EPA. Thermal Conversion of Municipal
Wastewater Sludge Phase II: Study of Heavy
Metal Emissions. EPA-600/2-81-203 (NTIS
PB82-111816). September 1981.
2-17
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76. U.S. EPA. Toxic Air Pollutant/Source Cross-
walk. A Screening Tool for Locating Possible
Sources Emitting Toxic Air Pollutants, Second
Edition. EPA-450/2-89-017 (NTIS PB90-170002).
December 1989.
77, U.S. EPA. Handbook: Control Technologies for
Hazardous AirPollutants.EPA625/6-86-014(NTIS
PB91-228809). Cincinnati, OH. September 1986.
78. U.S. EPA. BACT/LAER Clearinghouse - A
Completion of Control Technology Determin-
ations. EPA/450/3-90-015a-d. Research Triangle
Park, NC, July 1990.
2-18
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Chapter 3
Control Device Selection
3.1 Background
Guidelines that will enable the user to select the control
technique(s) that can be used to control HAPs are
presented in this chapter. The control techniques that
can be applied to control HAP emissions from a specific
emission source will depend on the emission source
characteristics and HAP characteristics. Therefore, Sec-
tion 3.2, Vapor Emissions Control, and Section 3.3,
Paniculate Emissions Control each pertain to specific
HAP groups. The discussion of control technique selee^
tion within each section is according to type of HAP
(organic or inorganic) and emission source (point, pro-
cess fugitive, or area fugitive).
Inthe following sections, guidelines for selecting controls
for point sources are discussed in detail. Point sources
are typically controlled by add-on control devices. For
each control technique, ranges of applicability with re-
spect to emission stream characteristics, HAP charac-
teristics, performance levels (e.g., removal efficiency),
and other considerations that are important in control
device selection are described in detail.
Work practices, including equipment modifications, play
a key role in reducing emissions from process fugitive
and area fugitive sources. These sources can also be
controlled by add-on control devices if the emissions can
be captured by hooding or enclosure or collected by
closed vent systems and then transferred to a control
device. Note that the overall performance of the control
system will then be dependant on both the capture
efficiency of the fugitive emissions and the efficiency of
the control device.
To illustratethe control device selection process, several
emission stream scenarios are presented throughout
this chapter. The emission stream from the paper
coating drying oven introduced in Chapter 2 is one of
the scenarios presented. The data necessary for control
device selection are recorded on the HAP emission
Stream Data Form (see Rgure 2,1).
3.2 Vapor Emissions Control
3.2.1 Control Techniques for Organic Vapor
Emissions from Point Sources
The most f requ ent approach to point source control is the
application of add-on control devices. These devices can
be of two types: combustion and recovery. The combus-
tion devices discussed in this manual include thermal
incinerators, catalytic incinerators, flares, and boilers/
process heaters. Applicable recovery devices include
condensers, adsorbers, and absorbers. The combustion
devices are the more commonly applied control devices,
since they are capable of high removal (i.e., destruction)
efficiencies for almost any type of organic vapor HAP
although carbon adsorbers are also quite popular. Com-
bustion devices serve as an ultimate control technique;
that is, they destroy rather than collect pollutants. With
carbon adsorbers and condensers, the VOC HAP must
be dealt with after collection. The removal efficiencies of
the recovery techniques generally depend on the physi-
cal and chemical characteristics of the HAP under con-
sideration as well as the emission stream characteristics.
Applicability of the control techniques depends more on
the individual emission stream under consideration than
on the particular source category (e.g., degreasing vs.
surface coating in solvent usage operations source cat-
egory). Thus, selection of applicable control techniques
for point source emissions is made on the basis of
stream-specific characteristics and desired control effi-
ciency. The key emission stream characteristics and
HAP characteristics that affect the applicability of each
control technique are identified in Table 3.1 and limiting
values for each of these characteristics are presented.
Matching the specific characteristics of the stream under
consideration with the corresponding values in Table 3.1
will help the user to identify those techniques that can
potentially be used to control the emission stream. The
list of potentially applicable control techniques will then
be narrowed further depending on the capability of the
3-1
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Table 3,1. Key fin/ssten Stream and HAP Characteristics for Selecting Control Techniques for Organls Vapors From Point Sources
Emission Stream Characteristics HAP Characteristicsa
Control Device
Thermal
Incinerator
Catalytic
Incinerator
Rare
Boiler/
Process heater*
Carbon
adsorber
HAP/Organics
Content
(ppmv)
>20;
(<25% of LELC)
50-10,000;
(<25% of LELC)
700-10,000
(<25% of LEL")
Heat
Content
(Btu/scf)
>3008
>1SO"
Moisture
Content Flow Rate Temp.
% (scfm) (°F)
<50,000d
<50,000
<2,000,000f
Steady
<50%' 300-200,000 S130
Molecular
Weight
(Mb-
mole)
45-130
Vapor Adsorptive
Solubility Pressure Properties
(mm Hg)
Must be able
to absorb on/
desprb from
available
adsorbents
Absorber
Condenser
250-10,000
>5,000-10,000
1,000-100,000
<2,000
Must be readily
soluble in water
or other solvents
>10 (at
room temp-
erature)
* Refers to the characteristics of the individual HAP if a single HAP is present and to that of the HAP mixture if a mixture of HAPs is present.
b Determined from HAP/hydrocarbon content.
0 For emission streams that are mixtures of air and VOC; in some cases, the LEL can be increased to 40 to 50 percent with proper moni-
toring and control (see Section 4.2 for definition of LEL).
* For packaged units; multiple-package or custom-made units can handle larger flows.
» Based on EPA's guidelines for 98 percent destruction efficiency.
1 Units: Ib/hr, Source: Reference 12.
* Applicable if such a unit is already available on site.
11 Total heat content
1 Relative humidity. Applicable for HAP concentration less than about 1,000 ppmv.
Thermal Incineration
T ?5% T
T T
Catalytic Incineration goo/CJ
1 1
Carbon Adsorption
Absorption
Condensation
1 1 1
99%
95% to 98%
50% 90% to 95%
|BL "T" ^. ~T*
J J
90% ns%
T .. "TT, ,„ f
IT T
50% 80%
j 1
III 1 III
T
99%
_ T
tf j
l
95%
I
10
20
50
100
200 300 500 1,000
Inlet Concentration, HAP, (ppmv)
Figure 3.1. Approximate percent reduction ranges for add-on equipment
2,000 3,000 5,000
10,000 20,000
3-2
-------
applicable control devices to achieve the required perfor-
mance levels. The expected emission reduction from the
application of each control technique on the basis of the
total VOC concentration in the emission stream is iden-
tified in Figure 3.1. Very little data regarding control
device removal efficiency for specific HAPs are avail-
able. Therefore, without actual source test data for a
specific emission stream and control system, HAP re-
moval efficiency is assumed to equal total volatile or-
ganic compound (VOC) removal efficiency.
32.1.1 Thermal Incinerators
Thermal incinerators are used to control a wide variety of
continuous emission streams containing VQCs. Com-
pared to the other techniques, thermal incineration is
broadly applicable; that is, it Is much less dependent on
HAP characteristics and emission stream characteris-
tics. Destruction efficiencies up to 99 + percent are
achievable with thermal incineration. Although they ac-
commodate minor fluctuations in flow, thermal incinera-
tors are not well suited to streams with highly variable
flow because the reduced residence time and poor
mixing during increased flow conditions decreases the
completeness of combustion. This causes the combus-
tion chamber temperature to fall, thus decreasing the
destruction efficiency.
Two types of thermal incinerators are commonly used.
The thermal recuperative type uses a conventional heat
exchanger to heat the incoming emission stream. The
thermal regenerative type uses ceramic beds to heat the
incoming stream. The discussion in Chapter 4 focuses
on thermal recuperative incinerators. Thermal regenera-
tive and thermal recuperative incinerators are discussed
,in Reference 19.
Thermal incineration typically is applied to emission
streams that are dilute mixtures of VOC and air. In such
cases, due to safety considerations, concentration of the
VOCs generally is limited by insurance companies to 25
percent of the LEL (lower explosive limit) forthe VOC in
question (see Section 4.2.2 for more details). Thus, if the
VOC concentration is high, dilution may be required.
When emission streams treated by thermal incineration
are dilute (i.e., low heat content), supplementary fuel is
required to maintain the desired combustion tempera-
tures. Supplementary fuel requirements may be reduced
by recovering the energy contained in the hot flue gases
from the incinerator. For emission streams with high heat
contents (e.g., >150 Btu/sef), the possibility of using the
emission stream as fuel gas should be considered.
The performance of a thermal incinerator is largely
dependent on the combustion chamber temperature. It
is, therefore, recommended that continuous monitoring
of this parameter be employed for control of HAPs.
Packaged single unit thermal incinerators are available
in many sizes to control emission streams with flow rates
from a few hundred up to about 50,000 scfm.
3.2.1.2 Catalytic incinerators
Catalytic incinerators .are similar to thermal incinerators
in design and operation except that they employ a cata-
lyst to enhance the reaction rate. Since the catalyst
allows the reaction to take place at lower temperatures,
significant fuel savings may be possible with catalytic
incineration.
Catalytic incineration is not as broadly applicable as
thermal incineration since performance of catalytic incin-
erators is more sensitive to pollutant characteristics and
process conditions than is thermal incinerator perfor-
mance. Materials such as phosphorus, bismuth, lead,
arsenic, antimony, mercury, iron oxide, tin, zinc, sulfur,
and halogens in the emission stream can poison the
catalyst and severely affect its performance. (Note: Some
catalysts can handle emission streams containing halo-
genated compounds.) Liquid or solid particles that de-
posit on the catalyst and form a coating also reduce the
catalyst's activity by preventing contact between the
VOCs and the catalyst surface. Catalyst life is limited by
thermal aging and by loss of active sites by erosion,
attrition, and vaporization. With proper operating tem-
peratures and adequate temperature control, these pro-
cesses are normally slow, and satisfactory performance
can be maintained for 2 to 5 years before replacement of
the catalyst is necessary.
Both fixed bed and fluid bed catalytic incinerators are
encountered. The discussion in Chapter 4 focuses on
fixed bed catalytic incinerators. For more information on
fluid bed catalytic incineration, consult Reference 19.
Catalytic incineration can be less expensive than thermal
incineration in treating emission streams with low VOC
concentrations due to lower auxiliary fuel requirements.
Emission streams with high VOC concentrations should
not be treated by catalytic incineration without dilution
since such streams may cause the catalyst bed to over-
heat and lose its activity. Also, fluctuations in the VOC
content of the emission stream should be kept to a
minimum to prevent damage to the catalyst.
Destruction efficiencies of 95 percent of HAPs can typi-
cally be achieved with catalytic incineration.16'20 Higher
destruction efficiencies (98 to 99 percent) are also achiev-
able, but require larger catalyst volumes and/or higher
temperatures, and are usually designed on a site specific
basis.20
The performance of a catalytic Incinerator is largely
dependent on the temperature rise across the catalyst
bed. This temperature rise is partially dependant on the
amount of catalyst present which is indicated by the
pressure drop across the catalyst bed. It is recom-
mended that continuous monitoring of both these param-
eters be employed for control of HAPs.
Catalytic Incinerators have been applied to continuous
emission streams with flow rates up to about 50,000
scfm.
3-3
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3.2,1.3 Flares
Flares are commonly used for disposal of waste gases
during process upsets (e.g., start-up, shutdown) and
emergencies. They are basically safety devices that are
also used to destroy waste emission streams.
Flares can be used for controlling almost any VOC
emission stream. They can be designed and operated to
handle fluctuations in emission VOC content, inert con-
tent, and flow rate. There are several different types of
flares including steam-assisted, air-assisted, and pres-
sure head flares. Steam-assisted flares are very com-
mon and typically employed in cases where large vol-
umes of waste gases are released. Air-assisted flares
are generally used for moderate relief gas flows. Pres-
sure head flares are small; they are used in arrays of up
to 100 individual flares. Normally, only a few of the flares
operate. The number of flares operating is increased as
the gas flow increases.
Flaring is generally considered a control option when the
heating value of the emission stream cannot be recov-
ered because of uncertain or intermittent flow as in
process upsets or emergencies. If the waste gas to be
flared does not have sufficient heating value to sustain
combustion, auxiliary fuel may be required.
Based on studies conducted by EPA, 98 percent de-
struction efficiency can be achieved by steam-assisted
flares when controlling emission streams with heat con-
tents greater than 300 Btu/scf.3-12-17 Note that a stream
with such a high heat content may serve as a fuel gas for
an incinerator if one is employed at the she. Depending
on the type of flare configuration (e.g., elevated or
ground flares), the capacity of flares to treat waste gases
can vary up to about 100,000 Ib/hr for ground flares and
2 million Ib/hr or more for elevated flares. The capacity of
an array of pressure head flares depends on the number
of flares in the array. For control of HAPs, it is recom-
mended that a continuous monitoring systemiforthe pilot
flame be employed for flares controlling intermittent
streams, and that the flare flame be continuously moni-
tored for flares controlling continuous streams.
3.2.1.4 Boilers/Process Heaters
Existing boilers orprocess heaters can be used to control
emission streams containing organic compou nds. These
are currently used as control devices for emission streams
fromseveral industries (e.g., refinery operations, SOCMI
reactor processes and distillation operations, etc.)
Typically, emission streams are controlled in boilers or
process heaters and used as supplemental fuel only if
they have sufficient heating value (greater than about
150 Btu/scf). In some instances, emission streams with
high heat content may be the main fuel to the process
heater or boiler (e.g., process off-gas from ethylbenzene/
styrene manufacturing). Note that emission streams with
tow heat content can also be burned in boilers or process
heaters when the flow rate of the emission stream is
small compared to the flow rate of the fuel/air mixture.
When used as emission control devices, boilers or pro-
cess heaters can provide destruction efficiencies of
greater than 98 percent at small capital cost and little or
no fuel cost. In addition, near complete recovery of the
emission stream heat content is possible.
There are some limitations in the application of boilers or
process heaters as emission control devices. Since
these combustion devices are essential to the operation
of a plant, only those emission streams that will not
reduce their performance or reliability can be controlled
using these devices. Variations in emission stream flow
rate and/or heating value could adversely affect the
performance of a boiler or process heater. By lowering
furnace temperatures, emission streams with large flow
rates and low heating values can cause incomplete
combustion and reduce heat output. The performance
and reliability of the process heater or boiler may also be
affected by the presence of corrosive compounds in the
emission stream; such streams are usually not em-
ployed with these devices.
3.2.1.5 Carbon Adsorbers
Carbon adsorption is commonly employed as a pollution
control and/or a solvent recovery technique. It is applied
to dilute mixtures of VOC and air. Although carbon
(which comes in different grades) is the most widely used
adsorption media, other adsorption media include silica
gel and alumina. Carbon adsorption is the focus of this
discussion. Removal efficiencies of 95 to 99 percent can
be achieved using carbon adsorption. The maximum
practical inlet concentration is usually about 10,000
ppmv but virtually all applications will have significantly
lower concentrations. The inlet concentrations are typi-
cally limited by the adsorption capacity of the carbon bed
or safety problems posed by high bed temperatures
produced by heat of adsorption and presence of flam-
mable vapors. Outlet concentrations around 50 ppmv
can be routinely achieved with state-of-the-art systems;
concentrations as low as 10 to 20 ppmv can be achieved
with some compounds.3-18 In contrast to incineration
methods whereby the VOCs are destroyed, carbon ad-
sorption provides a favorable control alternative when
the VOCs in the emission stream are valuable.
High molecular-weight compounds that are character-
ized by low volatility are strongly adsorbed on carbon.
The affinity of carbon for these compounds makes it
difficult to remove them during regeneration of the car-
bon bed. Hence, carbon adsorption is not applied to such
compounds (i.e., boiling point above 400° F; molecular
weight greaterthan about 130), Highly volatile materials
(i.e., molecular weight less than about 45) do not adsorb
readily on carbon; therefore, adsorption is not typically
used for controlling emission streams containing such
compounds.
Carbon adsorption is relatively sensitive to emission
stream conditions. The presence of liquid or solid par-
ticles, high boiling organics, or polymerizable substances
may require pretreatment procedures such as filtration.
3-4
-------
DehurnVdiftcatlonmay be necessary ifthe emission stream
concentration is less than 1,000 ppmv and the emission
stream has a high humidity (relative humidity > 50 per-
cent).18 Cooling may be required ifthe emission stream
temperature exceeds 120° -130° F.
To prevent excessive bed temperatures resulting from
the exothermic adsorption process and oxidation reac-
tions in the bed, concentrations higher than 10,000 ppmv
must frequently be reduced. This is usually done by
condensation or dilution of the emission stream ahead of
the adsorption step. Exothermic reactions may also
occur if incompatible solvents are mixed in the bed,
leading topotymerization. If flammable vapors arepresent,
the VOC concentrations may be limited by insurance
companies to less than 25 percent of the LEL. If proper
controls and monitors are used, LEL levels up to 40 to 50
percent may be allowed. To ensure breakthrough does
not occur, continuous monitoring of the outlet bed con-
centration is recommended.
3.2.1.6 Absorbers (Scrubbers)
Absorption is widely used as a raw material and/or a
product recovery technique in separation and purification
of gaseous streams containing high concentrations of
VOCs. As an emission controltechnique, ft is much more
commonly employed for inorganic vapors (e.g., hydro-
gen sulfide, chlorides, etc.) than for organic vapors.
Using absorption as the primary control technique for
organic vapor HAPs is subject to several limitations and
problems as discussed below.
The suitability of absorption for controlling organic vapor
emissions is determined by several factors; most of these
factors will depend on the specific HAP in question. For
example, the most important factor is the availability of a
suitable solvent. The pollutant in question should be
readily soluble in the solvent for effective absorption
rates and the spent solvent should be easily regenerated
ordisposed of in an environmentally acceptable manner.
Another factor that affects the suitability of absorption for
organic vapor emissions control is the availability of
vapor/liquid equilibriumdataforthe specific HAP/solvent
system in question. Such data are necessary for design
of absorber systems. For uncommon HAPs, these data
are not readily available.
Another consideration involved in the application of ab-
sorption as a control technique is disposal of the ab-
sorber effluent (i.e., used solvent). Ifthe absorber effluent
containing the organic compounds is discharged to the
sewer, pond, etc., the air pollution problem is merely
being transformed into a water pollution problem. Hence,
this question should be addressed (e.g., are there chemi-
cal/physical/biological means for treating the specific
effluent under consideration?). In solvent recovery, used
organic solvents are typically stripped (reverse of ab-
sorption) and recycled to the absorber for economic
reasons. However, in HAP control applications, stripping
requirements will often be very expensive because the
residual organic concentrations in the solvent must be
extremely tow for it to be suftabfe for reuse. Afso, ifthe
VOCs in the effluent from the absorber have appreciable
vapor pressure (e.g., > 0.1 mm Hg), the possibility of
VOC emissions to the atmosphere should be consid-
ered.
In organic vapor HAP control applications, low outlet
concentrations will typically be required. Trying to meet
such requirements with absorption alone will lead to
impractically tall absorption towers, long contact times,
and high liquid-gas ratios that may not be cost effective.
Therefore, absorbers will generally be effective when
they are used in combination with other control devices
such as incinerators or carbon adsorbers.
Removal efficiencies in excess of 9i percent can be
achieved with absorption.
3.2,1.7 Condensers
Condensers are widely used as raw material and/or
product recovery devices. They are frequently applied as
preliminary air pollution control devices for removing
VOC contaminants from emission streams prior to other
control devices such as incinerators, adsorbers, or ab-
sorbers.
Condensers are also used by themselves for controlling
emission streams containing high VOC concentrations
(usually >5,000 ppmv). In these cases, removal efficien-
cies obtained by condensers can range from 50 to 90
percent although removal efficiencies at the higher end of
this scale usually require HAP concentrations of around
10,000 ppmv or greater. The removal efficiency of a
condenser is highly dependent on the emission stream
characteristics including the nature of the HAP in ques-
tion (vapor pressure-temperature relationship) and HAP
concentration, and the type of coolant used. Note that a
condenser cannot lower the inlet VOC concentration to
levels below the saturation concentration (or vapor pres-
sure) at the coolant temperature. When water, the most
commonly used coolant, is employed, the saturation
conditions represent high outlet concentrations. For ex-
ample, condenser outlet VOC concentrations are often
limited to above 10,000 to 20,000 ppmv due to the
saturation conditions of most of the organic compounds
at the temperature of the cooling water. Therefore, it is
not possible for condensation with water as the coolant to
achieve the low outlet concentrations that would be
required in HAP control applications.
Removal efficiencies around iO percent may be achieved
if lower temperatures than those possible with cooling
water are employed but this is generally only true if the
HAP concentration is very high (e.g. >10,000-20,000
ppmv).16 These low temperatures can be obtained with
coolants such as chilled water, brine solutions, or chlo-
rof luorocarbons. These refrigerated condenser systems
are often sold as packaged units. However, for extremely
low outlet HAP concentrations, condensation will usually
be infeasible.
Depending on the type of condenser used, there may be
potential problems associated with the disposal of the
3-5
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spent coolant. Therefore, using contact condensers that
generate such effluents for controlling HAP emissions is
not recommended.
Flow rates up to about 2,000 scfm can be considered as
representative of the typical range for condensers used
as emission control devices. Condensers for emission
streams with flow rates above 2,000 scfm and containing
high concentrations of noncondensibles will require pro-
hibitively large heat transfer areas.
The temperature of the outlet steam is a fundamental
indicatorof performance for a condenser system. There-
fore, continuous monitoring of this parameter is recom-
mended for control of HAPs.
3.2.2 Control Techniques for Inorganic Vapor
Emissions From Point Sources
Inorganic vapors make up only a small portion of the total
HAPs emitted to the atmosphere. Potential sources of
the various inorganic vapors found in the atmosphere are
discussed in Chapter 2. Inorganic HAP vapors typically
include gases such as ammonia, hydrogen sulfide, car-
bonyl sulfide, carbon disulfide, metals with hydride and
carbonyl complexes, chloride, oxychloride, and cyanide.
In many cases, although the inorganic HAPs are emitted
as vapors at the emission source, they may condense
when passing through various ducts and form particu-
lates. Prior to discharge to the atmosphere, these par-
ticulates are typically controlled by methods that will be
discussed in Section 3.3. In this section, the discussion
will be based on control techniques for HAPs that are
emitted as vapors to the atmosphere.
Only a limited number of control methods are applicable
to inorganic vapor emissions from point sources. The two
most commonly used control methods are absorption
(scrubbing) and adsorption. Absorption is the most widely
used and accepted method for inorganic vapor control.
Although combustion can be used for some inorganic
HAPs (e.g., hydrogen sulfide, carbonyl sulfide, nickel
carbonyl), typical combustion methods such as thermal
and catalytic incineration are generally not applied. In
some cases, for example, in controlling hydrogen sulfide
emissions from gas wells and gas processing, flares are
used.
Applicability of absorption and adsorption as control
methods depends on the individual emission stream
characteristics. The removal efficiencies that can be
achieved will be determined by the physical and chemical
properties of the HAP under consideration. Other factors
(e.g., wastedisposal, auxiliary equipment requirements),
while not necessarily affecting the technical feasibility of
the control device, may affect the decision to use that
particular control method.
In the following two subsections, the applicability of
absorption and adsorption forcontrolling inorganic vapor
emissions will be discussed.
3.2.2.1 Absorbers (Scrubbers)
Absorption is the most widely used recovery technique
for separation and purification of inorganic vapor emis-
sions. The removal efficiency achievable with absorbers
can be greater than 99 percent. It will typically be deter-
mined by the actual concentrations of the specific HAP in
gas and liquid streams and the corresponding equilib-
rium concentrations. Table 3.2 summarizes the reported
efficiencies for various inorganic vapors employing ab-
sorption as the control method.
As discussed in Section 3.2.1.6 for organic vapors, the
suitability of absorption for controlling inorganic vapors in
gaseous emission streams is dependent on several
factors. The most important factor is the solubility of the
pollutant vapor in the solvent. The ideal solvent should
be nonvolatile, noncorrosive, nonflammable, nontoxic,
chemically stable, readily available, and inexpensive.
Typical solvents used by industry for inorganic vapor
control include water, sodium hydroxide solutions, amyl
alcohol, ethanolamine, weak acid solutions, and hypo-
chiorite solutions. Other factors which may affect inor-
ganic vapor absorption are similar to those for organic
vapor absorption (see Section 3.2.1.6).
Water is the ideal solvent for inorganic vapor control by
absorption. It offers distinct advantages over other sol-
vents, the main one being its low cost. It is typically used
on a once-through basis and then discharged to a waste-
water treatment system. The effluent may require pH
adjustment to precipitate metals and other HAPs as
hydroxides or salts; these are typically less toxic and can
be more easily disposed of.
3.2.2,2 Adsorbers
When the removal of inorganic vapors is especially
difficult using absorption methods, adsorption may prove
to be more effective. Adsorbents such as activated
carbon, impregnated activated carbon, silica gel, and
activated alumina are capable of adsorbing various inor-
ganic vapors and gases. The degree of adsorption is
dependent not only on the waste stream characteristics,
but also on the different characteristics of the adsorbents.
Carbon adsorption, using conventional and chemically
impregnated carbons, is widely used forcontrolling inor-
ganic vapors such as mercury, nickel carbonyl, phos-
gene, and amines. For example, when mercury vapors
are passed through a bed of sulfur-impregnated carbon,
the mercury vapors react with sulfur to form a stable
mercuric sulfide. Over 95 percent of the mercury re-
moved in this way can be recovered for reuse.
Important factors to consider when choosing an adsor-
bent for inorganic vapor control are very similar to those
fororganicvaporcontrol, which arediscussedin Section
3.2.1.5. Some of these factors include the amount of
adsorbent needed, temperature rise of the gas stream
3-6
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due to adsorption, ease of regeneration, and the useful
life of the adsorbent. Most of the reported removal
efficiencies for inorganic vapors are for activated carbon
and impregnated activated carbon, and range from 90 to
100 percent. Table 3.2 summarizes removal efficiencies
reported for various inorganic vapors controlled by ad-
sorption.
Activated carbons are the most widely used adsorbents
for inorganic vapor control. In several cases, they must
be treated (i.e., impregnated with chemical) for effective
application. Since activated carbons are relatively sensi-
tive to emission stream conditions, pretreatment of the
emission stream maybe necessary. Pretreatment meth-
ods such as filtration, cooling, and dehumidification may
be required depending on the emission stream condi-
tions. Filtration is usedto prevent plugging of the adsorber
bed by any solids or particles which may be in emission
stream. Ideal adsorption conditions for impregnated ac-
tivated carbons are relative humidities less than 50
percent and gas stream temperatures below 130° F.
Inorganic vapor concentrations are not recommended to
exceed 1,000 ppmv (preferably, less than 500 ppmv)
when activated carbon is used as an adsorbent.
3.2.3 Control Techniques for Organic/Inorganic
Vapor Emissions from Process Fugitive
Sources
Process fugitive emissions are defined in this handbook
as emissions from a process or piece of equipment that
are being emitted at locations otherthan the main vent or
process stack. Process fugitive emissions include fumes
or gases which escape from or through valves, pumps,
compressors, access ports, and feed and/or discharge
openings to a process. Examples include a pump in light
liquid service, the open top of a vapor degreaser, the slag
or metal tap opening on a blast furnace, and the feed
chute on a ball mill. Process fugitive emission sources
can also include vent fans from rooms or enclosures
containing an emissions source. An example would be a
vent fan on a perchloroethylene dry cleaner or the vent
fan on a press room. Other examples of process fugitive
sources include cooling towers and process drains.
Fugitive emissions of organic vapors occur in plants
processing organic liquids and gases, such as petroleum
refineries, chemical plants, and plants producing chemi-
cally based products such as plastics, dyes, and drugs.
One group of emission sources found in plants of this
type is commonly referred to as equipment leaks. Fugi-
tive emissions of thistype result from incomplete sealing
of equipment at the point of interface of process flu id with
the environment. Control techniques for equipment leaks
include leak detection and repair programs and equip-
ment installation or configuration. The following discus-
sion contains Information about control techniques for
common types of processing equipment found in plants
processing organic materials. Control techniques and
control efficiencies for common types of processing
equipment are summarized in Table 3.3.
Pumps. Several types of equipment or equipment con-
figurations can be used to eliminate or capture all organic
vapors leaking from pump seals. There are, first of all,
leakless pumps, pumps designed with no Interface be-
tween the process fluid and the environment, such as
diaphragm seal, and canned pumps. These pumps ef-
fectively limit fugitive emissions. However, they are lim-
ited in application.
Sophisticated pump seals can also be used to capture or
eliminate fugitive emissions. Dual seal systems with
pressurized barrierf luids or low pressure systems vented
to control devices may be used in some applications.
Recent improvements by vendors have resulted in a
greater array of pumps available for hazardous materi-
als. These include pumps with new alloys and lining
materials, and new magnetic and other sealless designs
to reduce leaking. For more information, consult Refer-
ence 22. Another approach which may be used involves
venting the entire seal area to a control device. Capture
efficiencies should be virtually 100 percent in both sys-
tems vented to control devices. Then the overall control
efficiency would be limited by the efficiency of the control
device.
Tablo 3.2, Control Methods for Various Inorganic Vapors'
Absorption
Inorganic Vapor
Mercury (Hg)
Hydrogen chloride (HCI)
Hydrogen sulflde (HSS)
Calcium fluoride (CaF2)
Silicon tetrafluorfde (SiF4)
Hydrogen fluoride (HF)
Hydrogen bromide {HBr)
Titanium tetrachloride (TiCI4)
Chlorine (Cy
Hydrogen cyanide (HCN)
Reported
Removal
Efficiency (%)
95
95
98
95
95
85-95
99.95
99
90
Solvent
Brine/tiypochlorite solution
Water
Sodium carbonate/water
Water
Water
Water
Water
Water
Alkali solution
Reported
Removal
Efficiency (%)
90
100
99
Adsorption
Adsorbent
Sulfur-impregnated
activated carbon
Ammonia-impregnated
activated carbon
Calcined alumina
Ammonia-impregnated
active carbon
" References 1,3.
3-7
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Another approach to reducing (but not eliminating) or-
ganic fugitive emissions from pumps is leak detection
and repair programs. A leak detection and repair system
modeled after the one EPA developed for the New
Source Performance Standards (NSPS) of the synthetic
organic chemical industry (SOCM I) should achieve about
60 percent control efficiency.7 The efficiency of leak
detection and repair programs is dependent on several
factors such as frequency of monitoring, effectiveness of
maintenance, action level, an underlying tendency to
leak. These factors and their effect on control efficiency
have been studied and discussed in References 7,8,9
and 10. Also, models are available for calculating the
effectiveness of leak detection and repairprograms (e.g.,
see Reference 11).
Valves, As with pumps, control of fugitive emissions from
valves may be accomplished by installing equipment
designed to isolate the process fluid from the environ-
ment. But also as with pumps, leakless valves such as
diaphragm valves are limited in their application.
Leak detection and repair programs have been used to
reduce fugitive emissions from valves. As indicated above
for pumps, the control efficiency of a leak detection and
repair program depends on the frequency of monitoring,
the effectiveness of maintenance, the action level, the
underlying tendency to leak, and other factors. A leak
detection and repair program modeled after the one
developed by EPA for the NSPS of the SOCMI should
achieve a control efficiency of about 70 percent for valves
in as service and about 50 percentforvalves in light liquid
service.7
Table 3.3. Summary of Control Effectiveness for Controlling
Organic Process Fugitive Emission Sources *
Emission Source
Pumps
Valves
•Gas
•Light liquid
Pressure relief
valves
Open-ended lines
Compressors
Control Technique Control
Equipment Effectiveness6
Modification {%)
Monthly leak detection
and repair
Seamless pumps
Dual mechanical seals
Closed vent system6
Monthly leak detection
and repair
Diaphragm valves
Monthly leak detection
and repair
Diaphragm valves
Rupture disk
Closed vent system"
Caps, plugs, blinds
Mechanical seals with vented
61
100
100
100
73
100
46
100
100
100
100
degassing reservoirs 100
Closed vent system" 100
Sampling connections Closed purge sampling
100
Raference 7,
Closed vent systems are used to collect and transfer the fugitive
•missions to add-on control devices such as flares, Incinerators,
or vapor recovery systems.
Pressure Relief Valves. Fugitive emissions from pres-
sure relief valves may be virtually eliminated through the
use of rupture disks to prevent leakage through the seal.
Fugitive emissions may also be added to gases collected
in a flare system by piping the relief valve to a flare
header. The control efficiency, then, depends on the
destruction efficiency of the flare. If flares are operated in
accordance with flare requirements established by EPA
for sources complying with NSPS, at least 98 percent
control efficiency should be achieved.
Open-ended Lines. Leakage of organic vapors through
valve seats to the open ends of pipes can be eliminated
by the installation of caps, plugs, or blind flanges. The
control efficiency should be 100 percent as long as the
plugs and caps remain in place.
Compressors. Fugitive emissions from compressor seals
can be controlled by venting the seal area to a flare or
other control device. Barrier fluid systems can also be
used to purge the seal area and convey leakage to a
control device. Capture efficiency should be 100 percent
and, therefore, the overall control efficiency would de-
pend on the efficiency of the control device.
Sampling Connections. Fugitive emissions from sam-
pling connections can be controlled by returning the
purged material to the process or by disposing of ft in a
control device. The practice of returning purged material
to the process in a closed system should achieve almost
100 percent control efficiency. The control efficiency
achieved by diverting the collected purge material to a
control device depends on the efficiency of the device.
Some process fugitive sources can be controlled by add-
on control devices once the emissions from the sources
are captured by hooding, enclosures, or closed vent
systems and then transferred to a control device. Be-
cause of the nature of the opening (e.g., for access or
maintenance), the opening through which emissions
escape cannot be totally enclosed or blanked off. Opera-
tors have to access the equipment or materials have to be
fed or discharged from the process. For this reason,
hoods or partial enclosures are used to control emissions
from such openings.
Proper hood design requires a sufficient knowledge of
the process or operations so that the most effective hood
or enclosure can be installed to provide minimum ex-
haust volumes for effective contaminant control. In theory,
hood design is based upon trying to enclose the process
and keep all openings to a minimum and located away
from the natural path of containment travel. Where pos-
sible, inspection and maintenance openings should be
provided with doors. In practice, hoods are designed
using the capture velocity principle which involves cre-
ation of and air flow past the source of containment
sufficient to remove the highly contaminated air from
around the source or issuing from that source and draw
the air into an exhaust hood. The capture velocity prin-
ciple is based on the fact thai small dust particles travel
3-8
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very short distances (on the otherof inches) when thrown
or emitted from a source and therefore, can be assumed
to follow air currents. Vapors and gases exhibit the same
effects.
In practice, hood capture efficiency is very difficult to
determine and therefore, when evaluating a hood, one of
the few parameters that can be considered is the capture
velocity. Standard design values of capture velocity are
available from the American Conference of Government
Industrial Hygienists in the Industrial Ventilation Manual
(see Table 3.4).z Once a capture velocity has been
determined, the volume of air required should be based
on maintaining this capture velocity and should be suffi-
cient to overcome any opposing air currents. (For addi-
tional information on hood design guidelines for several
industries, see Reference 2.)
Very few measurements of hood capture efficiency have
been conducted,4-8 Hood capture efficiencies of between
90 and 100 percent are possible depending on the
situation and the particular process fugitive sources
being controlled. For sources where operator access is
not needed and where inspection doors can be provided,
efficiencies toward the upper end of the range are achiev-
able. For sources where emissions are more diffused, for
example, from printing presses, capture efficiencies of
90 percent may be difficult. In the flexible vinyl and
printing industry, 90 percent is typically the upper bound
for capture efficiency on coating presses.4-21 In the pub-
lication rotogravure industry, capture efficiencies of 93 to
97 percent have been demonstrated based on material
balances.5
Once the process fugitive emissions are captured, the
selection of the control device will be dependent on the
emission stream characteristics, HAP characteristics,
and the required overall performance levels (e.g., re-
moval efficiency). Note that the required performance
level for the control device will be determined by the
capture efficiency. The factors that affect the control
device selection process are the same as for point
sources; therefore, refer to Sections 3.2,1 and 3.2.2.
For process fugitive emission sources such as process
drains, the control alternatives involve a closure or a seal.
A common method involves the use of a P-leg in the drain
line with a water seal. A less common, but more effective
method, is a completely closed drain system. Several
factors affect the performance of water-sealed drains in
reducing organic emissions: drainage rate, composition
and temperature of the liquid entering the drain, diameter
of the drain, and ambient atmospheric conditions. Emis-
sion reductions from water-sealed drains will vary de-
pending upon the specific application. In a completely
closed drain system^ the system may be pressured and
purged to a control device to effectively capture all
emissions. The control efficiency would then depend on
the efficiency of the control device.
Process fugitive emissions from cooling towers have not
been reliably quantified due to difficulties encountered in
measuring them and no specific control guidelines have
been developed.8 Probably the best control technique
currently available is close monitoring of heat exchang-
ers and other equipment to detect small leaks as they
occur.
Table 3.4. Range of Capture Velocities'
Condition of
Contaminant Dispersion
Released with practically no velocity into quiet air
Released at low velocity into still air
Examples Capture
Velocity (fpmb)
Evaporation from tanks; degreasing, etc.
Spray booths; intermittent container filling;
50-100
100-200
AcUve generation into zone of rapid air motion
Released at high initial velocity into zone of very
rapid air motion
low speed conveyor transfers; welding;
plating; pickling
Spray painting in shallow booths; barrel 200-500
filling; booths; conveyor loading
crushers
Grinding; abrasive blasting; tumbling 500-2,000
In each category above, a range of capture velocities is shown. The proper choice of values depends on several factors:
Lower End of Range:
Rome air currents minimal or favorable to capture.
- Contaminants of low loxicity or of nuisance value only.
- Intermittent, low production.
- Large hood-large air mass in motion.
Upper End of Range: •
- Disturbing room air currents.
- Contaminants of high toxicity,
- High production, heavy use.
- Small hood-local control only. •
• References.
b fpm = feet per minute.
3-9
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3.2,4 Control Techniques for Organic/Inorganic
Vapor Emissions from Area Fugitive
Sources
The control measures that can be employed for control-
ling organic or inorganic vapor emissions from area
fugitive sources are basically the same. Control tech-
niques for organic and inorganic vapor emissions are
discussed.
Area fugitive emission sources may include lagoons and
ponds where liquid waste streams containing organic
compounds are disposed of. Emissions and emission
rates of organic vapors from such sources are not well
documented, and such sources are not easily controlled.
The best method currently available for reducing emis-
sions from lagoons and ponds is enhancing upstream
treatment processes, thereby minimizing the amount of
organic material reaching the lagoons and/or ponds.
Other emission control techniques include surface enclo-
sures and impoundments.
Area fugitive emissions of inorganic vapors may be found
in plants processing inorganic chemicals, metals, elec-
tronics, and other products. Although extensive work has
not been done to quantify equipment leaks in plants
processing inorganic chemicals, it is expected that they
would be similar to equipment leaks encountered in
plants processing organic chemicals. Therefore, plants
processing highly volatile compounds such as hydrogen
ehiorkle or ammonia wou Id be expected to benefit by the
same control techniques applied to reduce or eliminate
fugitive emissions containing organic compounds as dis-
cussed in Section 3.2.3. There are some differences to
keep in mind, however. First, forthose control techniques
that employ a control device to treat collected vapors, the
control device wili probably differ. Instead of a combus-
tion device, an absorber, condenser, or an adsorber may
be a more appropriate choice. Another difference would
be relevant to leak detection and repair programs. Leak
detection and repair programs for organic vapors were
developed using portable organic analyzers. Portable
analyzers that respond to the inorganic vapors of con-
cern would have to be used for leakdetection of inorganic
materials.
Controlling inorganic vaporemissions from area sources
such as lagoons and/orppnds where liquid waste streams
containing volatile organic compounds are disposed of is
quite difficult. The best control method currently available
is minimizing the quantity of inorganic compounds reach-
ing the lagoon and/or pond by improving upstream treat-
ment processes.
3.2.5 Control Device Selection for a Hypothetical
Facility
This subsection illustrates the control device selection
process discussed in the previous sections for a hypo-
thetical facility with several emission streams. Assume
that the owner/operator of this facility has requested
assistance regarding the control of these emission
streams. The data supplied by the owner/operator are
presented in Figures 3.2 through 3.8.
Emission Stream 1 (see Figure 3.2). This stream is the
same as that described in Chapter 2 in the Example
Case. Assuming the HAP control requirement is 99
percent reduction, from Figure 3.1, the only applicable
control technique for this level of performance at concen-
tration levels of ~1000 ppmv is thermal incineration. The
HAP concentration is less than 25 percent of the LEL for
the HAP (see Table 4.2-1); hence, the concentration limit
indicated in Table 3.1 will not be exceeded. Also, the flow
rate of Emission Stream 1 falls in the range of application
indicated for thermal incinerators in Table 3.1.
Emission Stream 2(see Figure 3.3). Assume the HAP
controj requirement for Emission Stream 2 is 95 percent
reduction. For this level of performance, the applicable
control techniques for inlet concentrations of ~500 ppmv
are thermal incineration, catalytic incineration, and ab-
sorption. If either of the incineration techniques are
applied, the concentration limit indicated in Table 3.1 will
not be exceeded since the HAP concentration is less
than 25 percent of the LELforthe HAP (see Table 4.2-1).
The flow rate of Emission Stream 2 falls in the range
indicated as applicable in Table 3.1 for these control
techniques. The final selection of the control technique
should also be based on design and cost criteria (Chap-
ter 4).
Emission Stream 3 (see Figure 3.4). Assume the HAP
control requirement for Emission Stream 3 is 98 percent
reduction. In this case, the inlet HAP concentration falls
outside the range indicated in Figure3.1 ; therefore, none
of the control devices in this figure are applicable. Note
that dilution air could be used to decrease the HAP
concentration. Alternatively, this stream may warrant
consideration as a fuel gas stream. However, for ex-
ample purposes, assume this stream is to be flared.
According to Section 3,2,1.3, flares can be used to
control emission streams with high heat contents; hence,
flaring can be considered an option. Also, if a boiler or a
process heater is available on site, it can be used to
control Emission Stream 3.
Emission Stream 4 (see Figure 3.5). Assume the HAP
control requirement for Emission Stream 4 is 95 percent
reduction. For this level of performance, the applicable
control techniques for inlet concentrations of ~1,QOO
ppmv are thermal incineration, catalytic incineration,
carbon adsorption, and absorption. If either of the incin-
eration methods or carbon adsorption is applied, the
concentration limit indicated in Table 3.1 will not be
exceeded since the HAP concentration is less than 25
percent of the LEL (see Table 4.2-1). The flow rate of
Emission Stream 4 falls in the range indicated as appli-
cable in Table 3.1 forthese control techniques. The final
selection of the control technique should also be based
on design and cost criteria (Chapter 4).
Emission Stream 5(see Figure 3.6). Assume the HAP
control requirement for Emission Stream 5 is 98 percent
reduction. Since this emission stream contains inorganic
HAPs, incineration techniques are not applicable. The
only control technique that is applicable for this level of
3-10
-------
figure 3.2. Effluent characteristics for emission stream #1.
HAP EMISSION STREAM DATA FORM*
Glaze Chemical Company
Company.
Location (Street) 87 Octane Drive
(City) Somewhere
Plant Contact Mr. John Leaks
Telephone No. (999)555-5024
(State, Zip).
Agency Contact Mr. Efrem Johnson
No. of Emission Streams Under Review 7
A.
B.
C.
D.
E,
R
G.
H.
I.
J.
K,
L,
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification #1
HAP Emission Source (a) paper coating oven
Source Classiflcation (a) process point
Emission Stream HAPs (a) toluene
HAP Class and Form (a) organic vapor
HAP Content (1.2.3V" (a) osn ppmv '
HAP Vapor Pressure (1 .2) (a) 28 & mm Hg a» 77° F
HAP Solubility (1,2) (a) insoluble in wafer"
HAP Adsorptive Prop. (1.2) (a) provided
HAP Molecular Weight (1,2) (a) 92 Ib/lb-mete
Moisture Content (1 ,2,3) 9% volume
Temperature (1,2,3) 120° F
Flow Rate (1,?,S) 15,000 sefm (max)
Pressure (1 .21 atmospheric
Halogen/Metals (1,2) none/none
Applicable Requlafion(s)
Required Control Level
Selected Control Methods
/ #3 Oven Exhaust
(W
flto
-------
Figure 3.3, Effluent characteristics for emission stream #2,
HAP EMISSION STREAM DATA FORM*
Glaze Chemical Company
Company.
Location (Street) 87 Octane Drive
(Oily) Somewhere
Plant Contact Mr. John Leahe
telephone No. (999)555-5024
(Stats, Zip).
Agency Contact Mr. Efrem Johnson
No. of Emission Streams Under Review .7
A.
B.
C.
D.
E.
F.
a
H.
i.
j.
K.
L.
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification #2 /
HAP Emission Source (a) metal coating oven
Source Classification (a) process point
Emission Stream HAPs (a) toluene
HAP Class and Form (a) organic ygpQr
HAP Content (1,2,3)** (a) ssflppmv
HAP Vapor Pressure (1 .2) (a) 28 & mm Hg at 77° p
HAP Solubility (1 .2) (a) insoluble in water '
HAP Adsorptfve Prop. (1.2) (a) provided
HAP Molecular Wetahtn. 2) (a) a? ib/ib-mote
Moisture Content (1 .2.3) 2% volume
Temperature (1.2,3) 12(J° F
Flow Rate (1 ,?,3) Sfl.OOO scfm (max)
Pressure (1,2) atmospheric
Halogen/Metals (1 .2) none/none
Applicable Regulations)
Required Control Level assume 95% removal
*1 Oven Exhaust
fl))
(b)
(b)
(b)
ftrt
(b)
(b)
ftrt
(b)
P: Organic Content (1)***
Q. Heat/O Content (1) 2A
R. Panicuiate Content (3)
S. Particle Mean Diam. (3)
T. Drift Velocity/SO,, (3)
(c?
(c)
(c)
(0
(c)
(c)
(c)
none
Btu/sef/20.6 vol %
Selected Control Methods thermal incineration, catalytic incineration, absorption
The data presented are for an emission stream (single or combined streams) prior to entry into the selected control method(s).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the data on lines C and E:
1 - organic vapor process emission
2 - Inorganic vapor process emission
3 - paniculate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
are given as typical guidelines and should not be taken as
absolute, definitive values. Gas stream pretreatment
equipment can be installed upstream of the control
device (i.e., cyclones, precoolers, preheaters) which
enable the emission stream to fall within the parameters
outlined in Table 3.5.
The temperature of the emission stream should be within
50 to 100° F above its dew point if the emission stream
is to be treated (i.e., paniculate matter collected) by an
ESP or a fabric filter. If the emission stream temperature
is below this range, condensation can occur; condensa-
tion can lead to corrosion of metal surfaces, blinding and/
or deterioration of fabric filter bags, etc. If the emission
stream is above this range, optimal HAP collection may
not occur; by towering the emission stream temperature,
the vapor component of the HAP is reduced and, thus, an
ESP or fabric filter will collect the HAP more effectively.
Procedures for determining the dew point of an emission
stream are provided in Appendix B.1; brief discussions of
gas stream pretreatment equipment are presented in
Appendix B.3.
General advantages and disadvantages for each par-
ticular control device are identified in Table 3.6. Table 3.6
is used to provide additional information on otherconsid-
erations that, while not necessarily affecting the technical
feasibility of the control device for the stream, may affect
the overall desirability of using the device for a given
emission stream can be provided by using Tables 3.5
and 3.6 together. Thus, guidelines to determine if a
particular control device could and should be used for a
given emission stream. Further design and cost criteria
(Chapter 4} must be considered to enable a complete
technical evaluation of the applicability of these devices
to an emission stream.
Figure 3.9 provides the effluent characteristics for a
hypothetical incinerator emission stream after exit from a
heat exchanger. Assume the HAP control requirement is
99.9 percent, and that the HAP is cadmium. From Figure
3.9, note that the HAP content is 10 percent, the particu-
iate content is 3.2 gr/acf, the particle mean diameter is
1/im, and the drift velocity is 0.31 ft/sec.
3.3.1.1 Fabric Filters
Fabric filters, or baghouses, are an efficient means of
separating paniculate matter entrained in a gaseous
stream. A fabric filter is typically least efficient collecting
particles in the range of 0.1 to 0.3 jem diameter although
3-12
-------
Figure 3,4. Effluent characteristics for emission stream #3.
HAP EMISSION STREAM DATA FORM*
Chatninal Co
Company.
Location (Street) 97 Octane Drive
(City) Somewhere
any
Mr John lea to
(State, Zip).
Plant Contact .
Telephone No..
Agency Contact Mf Efretti Johnson
(999)
No. of Emission Streams Under Review
A.
B.
C.
D.
e.
F.
G.
H.
I.
J.
K.
L.
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification #3 /
HAP Emission Source (a) absorber vent
Source Classification (a) process plant
Emission Stream HAPs (a) methylene chloride
HAP Class and Form (a) orqanic vapor
HAP Content (1.2,3)" (a) 44.000 ppmv
HAP Vapor Pressure (1.2) (a) 436 mm Ha of 77° F
HAP Solubility (1.2) (a) insoluble in water"
HAP AdsorpUve Prop, (1.2) (a) not aiven
HAP Molecular Weight (1,2) (a) 85 Ib/lb-mote
Moisture Content (1.2.3) none
Temperature (1.2.3) 100°F
Flow Rate (1 2,3) 30,000 scfrrt expected
Pressure (1.2) atmospheric
Halogen/Metals (1.2) none /none
Applicable Regulation(s)
Required Control Level assume 98% removal
Selected Control Methods flare, boiler, process heater
Acetaldehyde Manufacturing Absorber Vent
(b)
ib)
(b)
(b)
ttrt
(b)
(b\
(trt
(b)
(c)
HA
(c)
(c)
fcrt
(c)
fc}
re)
(C}
P Organic Content (1)*" 17.8%volCH
Q. Heat/O2 Content (1) 1.§Q
R. Particufate Content (3)
S. Particle Mean Diam. (3)
T. Drift Velocity/SO., (3)
Btu/scf/none
The data presented are for an emission stream (single or combined sfreams) prior to entry into the selected control mettiod(s).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what date should be supplied depending on the data on lines C and E:
1 = organic vapor process emission
2 = inorganic vapor process emission
3 = particulate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
Table 3,5. Key Characteristics for Particulate Emission Streams'
Control
Device
Achievable
Efficiency
Range
Particle
Size
Limitation
Temperature
Corrosiveness/
Resistivity
Moisture
Content
Baghouse
Up to 99+%
ESP
Up to 99+%
Venturi
scrubber
Up to 89+%
Least efficient with
particles 0.1 nm to
0.3 um diameter.
Generally least
efficient with
particles around 1 u
diameter, but not as
sensitive to particle
size as other two
devices.
Generally operates
best with particles
>0.5 )un diameter.
Special fiber types necessary to
resist corrosion.
Dependent on
fiber type but
not exceeding
550° F without
a precooler
Generally up Corrosion resistant materials
to 1,000° F. , required. May require condi-
tioning agents for highly
resistive particles. Addition-
ally, ESPs are not used to
control organic matter since this
constitutes a fire hazard.
No general Special construction may be
limitations. required for corrosive emission
streams particularly for throat
section.
Poor efficiency with
emission streams of
high moisture content,
very sensitive changes
in moisture content of an
emission stream.
Can control streams with
relatively high moisture
content (i.e., 34% vol) if
so designed, but sensi-
tive to moisture changes
of an emission stream.
Not sensitive to changes
in moisture content of an
emission stream.
Characteristics given are designed to provide general, not definitive, guidance.
3-13
-------
Figure 3.5. Effluent characteristics lor emission aream #4.
HAP EMISSION STREAM DATA FORM*
Company PSta?a nhnmlfal Hnmpany
Mr John Leake
Location (Street) ,87 Octane Drive
(City) Somewhere
(State, Zip).
Plant Contact .
Telephone No,,
Agency Contact Mr. Efrem Johnson
.(999) 555-5024
No. of Emission Streams Under Review ._
A, Emission Stream Number/Plant Identification #d /
B, HAP Emission Source (a) printing pross
C. Source Classification (a) process point
D. Emission Stream HAPs (a) toluene
E. HAP Class and Form (a) org^nfe vapor
F. HAP Content (1.2,3)** (a) 1 obo ppmu
Q. HAP Vapor Pressure (1 ,2) (a) j>8,4 mm Hg «» 77° P
H. HAP Solubility (1.2) (a) inRnfiihte inwataf
1. HAP Adsorpfive Prop. (1.25 (a) prnvirffirf
J, HAP Molecular Welpht (1.2) (a) azib/ib-mola
K. Moisture Content (1.2.3) 40% rel, humidity
L. Temperature (1.2,3) 90.° F
M, FtnwRrtn (1,3,9) 15,000 scfm(rri3x)
N, Pressure (1.2) amiqsphfiric
O. Halogan/Metals (1.2) none /none
U. Applicable Regulation(s)
V. Required Control Level as-suma 9S% removal
#1 Printing Press
fbl
(W
ft*
(W
(b)
(b)
(b}
(b)
(b)
P. Organic Content (1) ***
Q. Heat/Oz Content (1)
R, ppHiaifate Content (3) „
S. Particle Mean Diam. (3)
T. Drift Velocity/SO., (3)
W. Selected Control Methods thermal incineration, catalytic incineration, carbon adsorotten. and
fc>
(c)
(0)
(c)
(c)
(0
(c)
(c)
(c)
nnnfl
4 ? Rtil/scf/90 fi% vol
absorption
The data presented are for an emission stream (single or combined steams) prior to entry into the selected control method(s).
Use exfta forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the data on lines C and E:
1 - organic vapor process emission
2 - Inorganic vapor process emission
3 - particulato process emission
Organic emission stream combustibles less HAP combustibles shown on lines Dand F.
efficiencies can still be quite high for this particle range.
Fabric filters used to control emissions containing HAPs
should have a closed, negative-pressure (suction) con-
figuration to prevent accidental release of the gas stream
and captured HAPs.
Fabric filters using mechanical shaking, reverse air, and
pulse-jet cleaning are fundamentally different from ESPs
and venturi scrubbers in that they are not "efficiency"
devices. A properly designed and operated fabric filter
using one of these two cleaning methods will yield a
relatively constant outlet particle concentration, regard-
less of inlet load changes. The typical outlet particle
concentration range is between 0.003 to 0.01 grains/scf
(gr/scf), averaging around 0.005 grains/scf.3-23 These
numbers can be used to ascertain an expected perfor-
mance level. This is not meant to be an absolute, defini-
tive performance level. A vendor should assist in any
attempt to quantify an actual performance level. Vari-
ables important to achieve agiven performance (i.e., air-
to-cioth ratio, cleaning mechanism, fabric type) are dis-
cussed in detail in Section 4.9.
Fabric filters are sensitive to emission stream tempera-
ture and a precooler or preheater may be required, as
discussed previously. Fabric filters operate at low pres-
sure drops, giving them low operating costs. Opacity
monitors located in the stack are often used to monitor
performance. In addition, the pressure drop across a
fabric filter is abasicindicatorof performance. For control
of HAPs, it is recommended that this parameter be
monitored continuously in conjunction with opacity mo-
nitors. Fabric filters are generally not a feasible choice to
control emission streams with a high moisture content
unless pretreatment is performed.
3.3,1.2 Electrostatic Precipitators
Electrostatic precipitator particle removal occurs by charg-
ing the particles, collecting the particles, and transport-
ing the collected par- tides into a hopper. ESPs are less
sensitive to particle size than the other two devices and
in fact can control submicron particles quite well, but are
very sensitive to those factors that affect the maximum
electrical power (voltage) at which they operate. These
are principally the aerosol density (grains/scf) and the
electrical resistivity of the material although wet ESPs are
much more insensitive to particle resistivity than dry
ESPs. The electrical resistivity of the particles in fluences
the drift velocity, or the attraction between the particles
and the collecting plate. A high resistivity will cause a low
3-14
-------
Figure 3.6. Effluent characteristics for emission stream #5.
HAP EMISSION STREAM DATA FORM*
Glaze Chemical Company
Company.
Location (Street) 87 Octane Drive
(City) Somewhere
Mr. John Leake
(State, Zip).
Plant Contact .
Telephone No.,
Agency Contact Mr Ffrern Johnson
555-5024
No. of Emission Streams Under Review
A.
B.
C.
D.
E.
F.
Q.
H.
1.
J.
K.
L.
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification #5
HAP Emission Source (a) evaporator pff-gas
Source Classification (a) process point
Emission Stream HAPs (a) ammonia
HAP Class and Form (a) inorganic vapor
HAP Content (1.2.3F* (a) 20,000 ppmv
HAP Vapor Pressure (1 .2) (a) a 46 atm at 68° F
HAP Solubility (1.2) (a) provided
HAP Adsorptive ProD. (1.2) (a) hot given
HAP Molecular Weight (1,2) (a) 17 Mb-mole
Moisture Content f 1 .2.3) 2% vol
Temperature (1.2.3) as° F
Flow Rate (1 2,3) 3,000 seta (max)
Pressure (1 .2) atmospheric
Haloaen/Metals (1.2) none /none
Applicable Requlation(s)
Required Control Level assume 98% removal
Selected Control Methods absorption
/ Urea Evaporator Off-gas FYhaust
(b)
fb)
ftrt
ftrt
(b)
(b)
(b)
(b)
(h)
P Organic Content (1) »«
Q. HeatfO. Content (1)
R Particiilate Content (3)
S. Particle Mean Diam. (3)
T. Drift Velocity/SO., (3)
to
(C)
(c)
. (c)
(c)
(c)
(c)
(c)
- (c?
The data presented are for an emission stream (single or combined streams), prior to entry into the selected control method(s).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the date on lines C and E:
1 = organic vapor process emission ,
2 - inorganic vapor process emission "
3 = part'culate process emission '
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
drift velocity which may decrease the overall collection
efficiency, A low resistivity indicates that it is difficult to
charge the particles and will tend to decrease the collec-
tion efficiency, all other things being equal. Electrostatic
precipitators are discussed further in Section 4.10.
An ionizing wet scrubber (IWS) may also be used for
paniculate collection. An IWS uses an electrostatic field
followed by a packed bed for two stage collection. These
devices are more insensitive to particle resistivity than
dry ESPs and can also scrub the gas stream for further
pollutant removal. See Section 4.10 for a further discus-
sion.
3.3,1.3 Venturi Scrubbers
Venturi scrubbers use an aqueous stream to remove
paniculate matter from an emissions stream. The perfor-
mance of a venturi scrubber is not affected by sticky,
flammable, or corrosive particles. Venturi scrubbers are
more sensitive to particle size distribution than either
ESP or fabric filters. In general, venturi scrubbers per-
form most efficiently for particles above 0.5 urn in diam-
eter (see Section 4.11 for further detail). Venturi scrub-
bers have a lower initial cost than either fabric filters or
ESPs, but the high pressure drop required for high
collection efficiencies contributes to high operating costs.
3.3.2 Control Techniques for Paniculate
Emissions from Fugitive Sources
Fugitive emission sources may be broken down into two
source categories: process sources and area sources,
&s defined in Section 2.2. The methods used to control
process sources of fugitive paniculate emissions are
generally different from those applied to area sources.
Basically, process fugitive sources can employ conven-
tional measures (i.e., capture techniques and add-on
control devices) while area fugitive sources either cannot
use conventional measures or the use of conventional
measures is precluded due to cost. For example, fugitive
emissions from unpaved roads cannot use conventional
control measures, but fugitive emissions from area
sources such as pumps and valves can be captured and
ducted to a control device, although the costs may be
prohibitive. Area sources are often controlled by preven-
tive techniques rather than capture/control techniques.
Section 3.2.3 discusses methods of hooding and capture
of process emissions. The remaining fugitive paniculate
emission control methodologies (i.e., nonconventional
techniques) can be applied to multiple fugitive emission
sources - both for process and area sources.
3-15
-------
ppmv SO, and
Since the HAP. constitutes;1:
This value assumeslthallliplif lilfpl
and that rt is collected
The following subsections discuss the different types
of fugitive paniculate emission control techniques that
can be applied to general process and area fugitive
particulate emission sources (i.e., sources common to
many industries).
An extensive review of available literature on fugitive
emissions revealed that a specific reference included
almost all necessary information pertinent to the scope
of this manual. Consequently, most of the following
subsections are takeni directly from the following docu-
ment: 'Technical Guidance for Control of Industrial
Process Fugitive Particulate Emissions."1* Reference
15 also provides the reader with a comprehensive
view of this subject.
Throughout thediscussions, control efficiencies arestated
for many of the control techniques. It is important to note
that the efficiency values are estimates. The ability to
quantify accurately the emission rates from a fugitive
emission source has not yet been fully realized.
3.3.2,1 Process Fugitive Particulate Emission
Control
Control of HAP process fugitive emissions may be ac-
complished by capturing the particulate material and
venting it to an add-on control device (i.e., venturi scrub-
bers, fabric filters, and ESP's). Venting emissions is
accomplished by exhausting particle-laden air through
fixed or movable ducting under negative pressure. The
airflow into the ducting must be sufficient to maintain
3-16
-------
Figure 3.7. Effluent characteristics for emission stream US.
HAP EMISSION STREAM DATA FORM*
Glaze Chemical Company
Company,
Location (Street) 87 Qctene Drive
(City) Somewhere
Mr. John Leake
f999\ 555-5024
(State. Zip)
Plant Contact
Telephone No.
Agency Contact
No. of Emission Streams Under Review
JEfrem Johnson
A.
B.
C.
D.
E.
F.
G.
H.
1.
J.
K.
L.
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification m I
HAP Emission Source fa) condenser vent
Source Classification (a) process point
Emission Stream HAPs (a) styretne
HAP Class and Form fa) nrganift «ap™-
HAP Content (1.2.3)** (a) I3~oooppm/
HAP Vapor Pressure (1.2) (a) pmuMed
HAP Solubility (1.2) (a) insoluble (r> water
HAP Adsorptive Prop. (1.2) (a) nntgh/en
HAP Molecular Weight (1 ,2) (a) lo.a'ih/ih -mole
Moisture Content (1.2.3) negligible
Temperature (1.2,3) 90° F
Plow Rate (1 (9(3) 2, OCX) «"*n (may)
Pressure (1.2) atmospheric
Halogen/Metals (1.2) none /none
Applicable Regulators)
Required Control Level assume 90% removal
Selected Control Methods ahsnrntinn rwinrifinsafion
Styrene Recovery CondenRsr Unit
fb)
(b)
(b)
(b)
fb)
fb)
(b)
(b)
P. Organic Content (1) ***
Q. HeaWX Content (1)
R. Particulate Content (3)
S, Particle Mean Diam. (3)
T. Drift .Velocity/So., (3)
(0)
fc)
fc)
(c)
(c)
fc)
(c)
fc)
fc)
none
61 .5 Btu/sef/20.7% vol
The data presented are for an emission stream (single or combined streams) prior to entry into the selected control methodfs).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the data on lines C and E:
1 = organic vapor process emission
2 = inorganic vapor process emission
3 = paniculate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
particle size capture velocity and to overcome opposing
air currents. The effect of opposing air currents can be
eliminated by complete enclosure, or can be reduced by
minimizing the opening of capture enclosures, or by
utilizing curtains or partitions to block room air currents.
If enclosure or installation of fixed hoods is not feasible
dueto space limitations or operational procedures, mov-
able hoods may be a viable alternative. Movable hoods
can be placed over the fugitive emission source as the
production cycle permits. For example, movable hoods
can be placed over the filling hatch in some types of
trucks and rail cars during loading. Movable hoods have
also been applied in the production of coke, whereby a
movable hood follows quench cars during coke pushing.
Another alternative is to evacuate an enclosed building to
a control device.
Once the emissions are captured, the selection of the
control device will be dependent on the emission stream
characteristics, HAP characteristics, and the required
performance levels (i.e., removal efficiency). It is impor-
tant to remember that the required performance level for
the control device is Influenced by the efficiency of the
capture system. The factors that affect the control device
selection process are the same as for point sources, and
are discussed in Section 3.3.1.
3,3.2.2 Area Fugitive Emission Control from
Transfer and Conveying
Loss of material from conveyors is primarily at the feed-
ing, transfer, and discharge points and occurs due to
spillageorwindage.The majority of paniculate emissions
are generally from spillage and mechanical agitation of
the material at uncovered transfer points. However,
emissions from inadequately enclosed systems can be
quite extensive. Table 3.7 presents control techniques
applicable to these emission sources.
Control by wet suppression methods includes the appli-
cation of water, chemicals, and foam. The point of appli-
cation is most commonly at the conveyor feed and
discharge points, with some applications at conveyor
transfer points. Wet suppression with water only is a
relatively inexpensive technique; however, ft has the
inherent disadvantage of being short-lived. Control with
chemicals (added to water for improved wetting) orfoam
is longer lasting but more expensive than water alone.
Foam is effective in dust suppression because small
particles (in the range of 1 to 50 Jon diameter) break the
surface of the bubbles in the foam when they come in
contact, thereby wetting the particles. Particles larger
than 50 um only move the bubbles away. The small
wetted particles then must be broughttogether or brought
3-17
-------
Tabta 3.6. Advantages and Disadvantages of Paniculate Control Devices,
Advantages
Disadvantages
Baghouse — Very efficient at removing fine paniculate matter from
a gaseous stream; control efficiency can exceed 99
percent for most applications.
— Lower system pressure drop than venturi scrubber
when controlling fine participates; i.e., 5" to 20* H2O
compared with > 40" HZO.
— Can collect electrically resistive particles.
— With mechanical shaking, reverse air cleaning, or
low pressure pulse-jet, control efficiency is generally
Independent of inlet loading.
— Simple to operate.
ESP *— Can control very small (0.1 urn) particles with high
efficiency.
— Low operating costs with very low system pressure
drop (5" H2O)
— Can collect corrosive or tar mists.
— Power requirements for continuous operation are low.
— Wet ESPs can collect gaseous pollutants and are less
sensitive to particle resistivity.
Venturi — Low initial Investment
scrubber — Takes up relatively little space.
— Can control sBcky, flammable, or corrosive matter with
few problems.
— Can simultaneously collect particulates and gaseous
matter.
— Control efficiency is independent of particle
resistivity.
— Simple to operate, few moving parts.
Cannot control high temp stream (>550° F) without a
precooler, or special fabric types.
Cannot effectively control stream with high moisture
content
Highly erosive particles can damage the filter.
Mechanical collectors generally required upstream If
significant amounts of large particulates (>20 urn) are
present
Needs special or selected fabrics to control corrosive
streams.
Least efficient with particles between 0.1 nm to 0.3 jim
diameter.
High Initial capital investment
Not readily adaptable to changing conditions.
Conditioning agents may be necessary to control
resistive particles.
Dry ESPs are more sensitive to particle loading, size
distribution, and resistivity than other two devices.
Space requirements may be greater than that for a fabric
filter or venturi scrubber.
High operating cost due to high pressure drop (40" H2O
or greater), particularly for smaller (<1(im) particles.
Has wastewater and cleaning/disposal costs.
Least efficient with particles less than 0.5 pm diameter.
in contact with larger particles to achieve agglomeration.
If foam Is injected into free-falling aggregate at a transfer
point, the mechanical motion provides the required par-
ticle to bubble contact and subsequent particle-to-par-
ticle contact. Highly diluted chemical wetting agents are
applied by water jets ahead of any points in the conveying
system where dusting occurs. The wetting agent breaks
down the surface tension of the water, allowing it to
spread further, penetrate deeper, and wet the small
particles better than untreated water. With mechanical
agitation of the material, the small particles agglomerate.
For effective control, the spray should be applied at each
point where the particles might be fractured, allowed to
tree fall, or subjected to strong air currents.
3.3.2.3 Area Fugitive Emission Control from
Loading and Unloading
Loading and unloading bulk material is common to many
processing industries. Loading and unloading opera-
tions can be either for external transportation of material
to or from a facility or for internal transportation within a
facility (for example, internal transportation might consist
of loading of a mining haul truck with ore via a front-end
loader for subsequent unloading to a crushing process).
Appendix A.8 should also be consulted for industry-
specific information on loading and unloading for internal
transportation.
Various control technology applications for loading and
unloading operations are presented in Table 3.8. These
techniques can be used alone or at times in various
combinations. Generally, the simultaneous use of more
than one technique will provide increased levels of con-
trol.
Rail Car and Truck Loading. To minimize participate
emissions from rail car and tmck loading, the entire
operation can be enclosed by the use of doors on the
loading shed. This prevents a wind tunnel effect and
allows dust emitted in the enclosure to settle to the
ground within the enclosure. By venting the entire enclo-
sure to a control device, dust leakage around the doors
and any other openings can be prevented, thus ens,u ring
near 100 percent control.
Exhausting the car or truck body to a dust removal device
reduces emissions if the body is fairly well enclosed. In
open type rail or truck bodies this technique is not too
effective.
Choke-feed eliminates free fall of material into the car or
truck. In this technique the mouth of the feed tube is
immersed in the material being unloaded. This technique
only works for fairly free-flowing dry material. A tele-
scopic chute or spout also essentially eliminates the free-
fall distance of the material being loaded. This type of
system can be used on all types of material. Both the
choke-feed and telescopic chute methods are only par-
tially effective in eliminating emissions since the surface
of the loaded material is constantly disturbed by new
3-18
-------
Figure 3.8, Effluent characteristics for emission stream #7.
HAP EMISSION STREAM DATA FORM*
Company
Location (Street)
(City)
Glaze Chemical Company
Mr .Inhn I oato
87 Octane Drive
Somewhere
(State, Zip).
Plant Contact .
Telephone No..
Agency Contact Mr. Efrem Johnson
555-5024
No. of Emission Streams Under Review
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
L.
M.
N.
O.
U.
V.
W.
Emission Stream Number/Plant Identification #7 / Spit Vapor Extraction /SVE) Vent
HAP Emission Soyroo (a) SVE vent
Source Classification (a) process point
Emission Stream HAPs (a) acetone
HAP Class and Form (a) organic vapor
HAP Content (1,2,3)** (a) 700ppmv
HAP Vapor Pressure (1 ,2) (a) orovided
HAP Solubility (1,2) (a) micisibie in water
HAP Absorptive Prop. (1,2) (a) provided
HAP Molecular Weight (1,2) (a) 58lMb-mole
Moisture Content (1,2,3) 4Q% rel hpmMlify
Temperature (1.2.3) 90° F
Flow Rate (1 ,2,3) 2,000 scfn (max)
Pressure (1.2) atmospheric
Haloaen/Metals (1 .2) none / none
Applicable Reaulation(s)
Required Control Level assume 90%
Selected Control Methods carbon adsorption canister system
(b)
(U
(to
(b)
ttrt
(b)
rw
(b)
(h)
P. Organic Content (1) "*
Q. HeaVO, Content (1)
R. Particufate Content (3)
S. Particle Mean Diam. (3)
T. Drift Velocity/SO., (3)
te\
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
none
1 .34 Btu/SCf/20.6% VOl
The data presented are for an emission stream (single or combined streams) prior to entry into the selected control meihod(s).
Use extta forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers In parentheses denote what data should be supplied depending on the data on lines C and E:
1 = organic vapor process emission
2 = inorganic vapor process emission
3 = partioulate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F.
material. This surface is subjecttowind and dust entrain-
ment.
Movable hoods exhausted to a dust removal system can
be placed over the filling hatch in some types of trucks
and railcars during loading. By keeping other openings
on the body closed, any dust generated in loading must
be emitted through the single open hatch. A hood with
sufficient airflow mounted around this opening could
capture most of the dust generated.
Wet suppression techniques, when applied to loading
operations, can reduce airborne dust to some extent.
The loading process naturally breaks up surface coat-
ings, but some small dust particles will adhere to larger
pieces so as not to become entrained. Many materials
cannot be readily wetted and this technique could not be
used for these materials.
Barge and Ship Loading. Duetotheirlargersize, barge
and ship loading present unique problems for dust con-
trol. However, anumberof corrtroltechniques have been
developed and utilized, especially at some of the larger
shipping terminals.
The use of tarpaulins or similar covers over hatches on
ships and enclosed barges reduces airborne emissions
by preventing their escape. Air, displaced by the material
being loaded, causes the hold to become slightly pres-
surized during loading, and the hold must be vented at
some point if the hatches are air-tight. Thus, a more
effective control system incorporates an exhaust system
for the hold. This exhaust system is connected to a dust
control system such as fabric filter with the collected
material being returned to the hold. Such a system can
practically eliminate loading emissions if carefully main-
tained and properly operated. The use of a canopy hood
and exhaust system over the loading boom is less
effective than a totally enclosed system, but can still
reduce emissions and is a viable alternative for open
barges. Effective utilization of this technique requires
some type of wind break to increase the hood capture
efficiency. Choke feed and telescopic chutes or spouts
as previously described can also be used for loading both
enclosed and open ships or barges. Wet suppression
techniques may also help reduce airborne emissions if
the product specifications do not prohibit use of this
technique.
3-19
-------
figure 3,9, Effluent characteristics fora municipal Incinerator emission stream
HAP EMISSION STREAM DATA FORM*
Company
Location (Street)
(City)
Incineration tnc
123 Main Street
Somewhere
Plant «nntnnt
Telephone No.
Agency Contact
Mr Phil BrnthAf**
(999) 555-5024
Mr Ben Mnlri
(State, Zip),
No. of Emission Streams Under Review
A.
B,
C,
D.
E.
F,
G.
H.
I.
J,
K.
L
M,
N.
O.
Emission Stream Number/Plant Identification ft / Incineration
HAP Emission Source (a) municipal incinerator
Source Classlflcafon (a) process point
Emission Stream HAPs (a) cadmium
HAP Class and Form (a) inoraanie particulate
HAP Content (1.2.3)** (a) 10%
HAP Vapor Pressure (1 ,2) (a)
HAP Solubility (1.2) (a)
HAP Adsorptivo Prop. (1,2) (a)
HAP Molecular Weiaht (1.2) (a)
Moisture Content ( 1 .2.3) 5% uoi
Temperature (1,2,3) 41)0° P
Flow Rate (1 ,5>,3) 1 1 0.000 acfm
Pressure (1.2) atmospheric
HaJooen/Metals (1 .2) none / none
fbl
A)
rt>5
fbl
(b)
M
(bi
ftrt
(h)
P. Organic Content (1)*"
Q. HeaWO Content (1)
R. Particulate Content (3)
S. Particle Mean Diam. (3)
T. Drift Vetocity/SO, (3)
(c)
(c)
(c)
(o)
(c)
(c)
(c)
(c)
(c)
3.2 gr/acf
1.0 urn
flya&h
0.31 ft/sec/200 ppmv
U, Applicable Regulation^) _
V. Required Control Level
W. Selected Control Methods
assume 99.9% removal
fabric filter. ESP, venturi scrubber
The data presented are for an emission stream (single or combined streams) prior to entry into the selected control method(s).
Use extra forms if additional space is necessary (e.g., more than three HAPs) and note this need.
The numbers in parentheses denote what data should be supplied depending on the data on lines C and E:
1 - organic vapor process emission
2 - inorganic vapor process emission
3 - paniculate process emission
Organic emission stream combustibles less HAP combustibles shown on lines D and F,
Rail Car and Truck Unloading. Many of the unloading
dust control techniques are identical to the loading tech-
niques. When a rail car ortruck is tilted and materials are
dumped into an underground chamber through a grating,
exhausting air from this chamber through a control de-
vice will effectively reduce emissions. By causing air to
flow down through the grating, dust emissions are con-
tained. The face velocity of air through the grating is a
critical design parameter in this technique. Unloading
cars with a screw conveyor causes less distribution of the
material and thereby less dust. Problems of material
handling and time requirements limit the application of
this technique. Pneumatic unloading of very fine materi-
als is an effective and widely used technique that practi-
cally eliminates dust emissions. With this system, careful
maintenance of hose fittings and the fabric filter through
which the conveying air exhausts is required.
Barge and Ship Unloading. Control of barge and ship
unloading requires enclosure of the receiving point on the
shore and possibly exhausting of that enclosure to a
control device. A good enclosu re with an exhaust system
can provide essentially 100 percent capture. For .open
ships and barges which use buckets and conveyors, a
partially enclosed bucket will reduce windblown dust.
When observation of the bucket by the operator is re-
Table 3.7, Control Technology Applications for Transfer and
Conveying Sources,
Emission Points
Conveyor system
(belt, bucket
elevator, etc.)
Transfer and
transition points
Control Procedure
Enclosure
1. Top covered (marginal control)
2. Sides and top covered (good control)
3. Completely enclosed (excellent con-
trol)
Wet suppression (water, chemical, foam)
at conveyor feed points.
Belt scrapers and wipers
Mechanical belt turnovers
Replacement with pneumatic system or
screw conveyor
Enclosure
Hoods, covers, or canopies with exhaust
to removal equipment (fabric filters, and
wet-collectors)
Wet suppression (water, chemical, foam)
3-20
-------
Table 3.8. Control Technology Applications for Loading and Unloading Operations
Control Procedures
Emission Points
Loading Operations
Unloading Operations
Railcar, truck
Barge, ship
Drive-through enclosure with doors at ends
Exhaust of entire enclosure to dust removal
equipment
Movable hood over hatch opening
Exhaust of car hopper to dust removal equipment
Choke-feed or telescopic chute to confine and
limit free-fall distance (gravity loading)
Wet suppression (water, chemicals)
Use of tarpaulins or covers over the holds
Canopy and exhaust system over the loading
boom, with attached tarps around the hatch
Exhaust of ship hold to dust removal equipment
Choke-feed or telescopic chute to confine and
limit free-fall distance
For tanker types, use of gravity filler spouts with
concentric outer exhaust
Wet suppression (water, chemicals)
Drive-through enclosure with doors at both
Exhaust of enclosure to dust removal equipment
Exhaust air from below grating of receiving hopper
to removal equipment
Chock-feed to receiving pit (hopper car and
hopper truck).
Unloading with screw conveyor (box car)
.Wet suppression (water, chemicals)
Use of pneumatic unloading system
Enclosure of top of clamshell bucket with
transparent material and maintenance of
closure seals and teeth on bottom of bucket
Enclosure of shoreside receiving hopper
Exhaust of enclosed shoreside receiving hopper
to dust removal equipment
quired, a transparent heavy plastic sheet can be used as
a cover. This system is only partially effective and must
usually be supplemented with other controls, such as
tighter fitting covers, wind breaks, or possibly wet sup-
pression.
3.3,2.4 Area Fugitive Emission Control from Paved
and Unpaved Roads
Dust on the surface of paved roads is deposited by such
processes as mud track-out on vehicletires, atmospheric
fallout, spillage or leakage from trucks, pavement wear
and decomposition, runoff or wind erosion from adjacent
land areas, deposition of biological debris, wear from
tires and brake linings, and wear of anti-skid compounds.
This material is reentrained by contact with tires and by
the air turbulence created by passing vehicles.
On unpaved roads, the road base itself serves as the
main source of dust. As with paved roads, the dust
becomes airborne by contact with vehicles' tires and by
air turbulence from passing vehicles. Also, some of the
fugitive dust from unpaved roads is attributed to wind
erosion. On both paved and unpaved roads, traffic move-
ment causes the continuing mechanical breakdown of
large particles on the road surface, thus providing new
material in the suspended paniculate size range. Avail-
able procedures for reducing emissions from plant roads
and their estimated efficiencies are presented in Table
3.9.
Paved streets and roads in a plant area can be cleaned
on a frequent schedule to reduce the amount of particu-
late material on the surface that is available for
reentrainment. Rushers and vacuum-type motorized
street cleaners are both quite effective in removing
surface material and thereby reducing emission rates
from vehicles using the cleaned streets. Because raw
material accumulates rapidly on the streets, the overall
effectiveness of a street-cleaning measure is a function
of the frequency of cleaning and the removal efficiency of
the equipment.
For plants with small amounts of paved roads, industrial
vacuum sweepers or contracted sweeping programs
(such as many shopping centers use) would be more
appropriate than the larger vacuum street cleaning equip-
ment used on public streets. Mechanical broom sweep-
ers have been shown to be ineffective from an air
pollution control standpoint in that they redistribute mate-
rial into the active traffic lanes of the streets and they
remove almost noneof the fine material (less than 43 um)
that is subject to reentrainment.
Many street sweepers depend upon the material being
concentrated in the gutter in order to achieve good
collection efficiency, and therefore cannot be used on
streets without curbs and gutters. However, the smaller
Table 3.9. Control Technology Applications for Plant Roads
Emission Points Control Procedure Efficiency
Paved sheets
Unpaved
roads
Road
shoulders
Street cleaning No Estimate
Housecleaning programs to
reduce deposition of material
on streets No estimate
Vacuum street sweeping2
(daily) 25%1S
Speed reduction Variable
Paving , 85%
Chemical stabilization 50%
Watering . S0%
Speed reduction Variable
Oiling and double chip surface 85%
Stabilization
80%
3-21
-------
industrial sweepers are usually designed for use in
warehouse and storage areas that are not curbed. A
factor which might limit the applicability of street f lushers
in plants is that unpaved areas adjacent to the streets
would be wet by the water spray and then become
subject to mud track-out onto the streets by equipment
and vehicles driving through these areas.
Good housekeeping practices include the rapid removal
of spills on roadways and at conveyor transfer points.
Preventive measures include covering of truck beds to
prevent windage losses, cleaning of truck tires and
undercarriages to reduce mud track-out onto paved
roads, and minimizing the pick-up of mud by trucks.
The paving of unpaved roadways is the most permanent
of the various types of controls. However, the degree of
effectiveness of this technique is highly dependent on
prevention of excessive surface dust loading.
Watering of unpaved roads is effective only when carried
out on a regu lar basis. The schedule depends on climate,
type of surface material, vehicle use, and type of ve-
hicles.
Oiling unpaved roads is more effective than watering and
needs to be applied less often. However, special precau-
tions must always be taken so as not to add to surface
water runoff problems.
3.3,2.5 Area Fugitive Emission Control From
Storage Piles
Most dust arises from stockpile areas as the material is
dumped from the conveyor or chute onto the pile, and as
bulldozers move the pile. During periods with high wind
speeds [greater than about 6 m/sec (13 mph)] or low
moisture, wind erosion of a non-weathered surface may
also cause emissions. Applicable control techniques for
open storage piles are presented in Table 3.10.
Tab!* 3.10.
Control Technology Applications for Open Storage
PIlos
Emission Points
Control Procedure
Efficiency
Loading onto
piles
Enclosure
Chemical welting agents
or foam
Adjustable chutes
70-99%
80-90%
75%
Movement of pile
Wind erosion
Enclosure
Chemical wetting agents
Watering
Traveling booms to
distribute material
95-99%
90%
50%
No estimate
Enclosure 95-99%
Wind screens Very low
Chemical wetting agents
or foam 80%
Screening of material prior
to storage, with fines sent
direcBy to processing or
to a storage silo
No estimate
Loadout
Water spraying 50%
Gravity feed onto conveyor 80%
Stacker/reclaimer 25-50%
Enclosing materials in storage is generally the most
effective means of reducing emissions from this source
category because it allows the emissions to be captured.
However, storage bins or silos may be very expensive.
Storage buildings must be designed to withstand wind
and snow loads and to meet requirements for interior
working conditions. One alternative to enclosure of all
material is to screen the material prior to storage, send-
ing the oversize material to open storage and the fines to
silos.
Wind screens, or partial enclosure of storage piles, can
reduce wind erosion losses but do not permit capture of
the remaining storage pile fugitive emissions. Earthen
berms, vegetation, or existing structures can serve as
wind screens.
Telescoping chutes, flexible chute extensions, and trav-
eling booms are used to minimize the free fall of material
onto the pile and resulting emissions. Similarly emis-
sions due to loadout can be reduced by reclaiming the
material from the bottom of the pile with a mechanical
plow or hopper system. The use of telescoping chutes
and flexible chute extensions for piles with high material
flow rates may require closer control of operations be-
cause of the possibility of jamming. Traveling or adjust-
able booms can handle high flow rates, but have greater
operating costs.
Wetting agents or foam that are sprayed onto the mate-
rial during processing or at transfer points retain their
effectiveness in subsequent storage operations. Wet-
ting agents retain surface moisture for extended periods,
thereby preventing dusting. Spraying of the material
prior to storage may not be possible in cases where
product contamination could result (e.g., Portland ce-
ment clinker) or where the material is water soluble.
However, such materials are generally not placed in
open storage anyway. Steam has also been found to be
an effective dust suppressant for some short-term stor-
age operations.
3.3.2.6 Area Fugitive Emission Control from
Waste Disposal Sites
Fugitive dust can occur anywhere dusty waste material
is dumped for disposal. This includes overburden piles,
mining spoils, tailings, fly ash, bottom ash, catch from air
pollution control equipment, process overbad discharges,
building demolition wastes, contaminated product, etc.
Like open storage, emissions come from dumping and
from wind erosion across unprotected surfaces. Since
waste piles are generally not disturbed after dumping,
there are no emissions from an activity comparable to
loading out of the storage pile. However, there may be
emissions from transporting the waste material on-site
(if ft is dry when ft is produced) or from a reclamation
process such as landfill covering associated with the
waste disposal operation. If the surface of the waste
material does not include a compound that provides
cementation upon weathering, or if the surface is not
compacted, or if an area of very little rainfall, wind
erosion of fines can occur wfthwinds greater than about
3-22
-------
2.1 km per hour (13 mph). Table 3.11 presents coMrol
techniques for waste disposal sites.
Table 3.11. Control Technology Applications for Waste
Disposal Sites
Emission Points
Control Procedure
Efficiency
Handling
Dumping
Keep material wet 100
Cover or enclosure hauling No estimate
Minimize free fail of material No estimate
Spray bar at dump area 50%
Minimal free fall of material No estimate
Semi-enclose bin No estimate
Wind erosion
Grading
Cover with dirt or stable
material
Chemically stabilize
Re vegetate
Rapidly reclaim newly
filled areas
Water
100%
80%
25%-100%
No estimate
50%
3.4 References
1. Control Technology for Toxic and Hazardous Air
Pollutants. McFarland, A.R., ed. Illinois Institute for
Environmental Quality. Chicago, Illinois. 1975.
2. Committee on Industrial Ventilation. Industrial Ven-
tilation: A Manual of Recommended Practice. 17th
Edition. Lansing, Michigan. 1982.
3. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. EPA-625/6-86-014. (NTiS
PB91-228809). September 1986.
4. U.S. EPA. Flexible Vinyl Coating and Printing Oper-
ations - Background Information for Proposed Stan-
dards. EPA-450/3-81-0163. (NTIS PB83-169136).
January 1983.
5. U.S. EPA. Publication Rotogravure Printing - Back-
ground Information for Proposed Standards. EPA-
450/3-80-031 a. (NTIS PB81 -117145). October 1980.
6. U.S. EPA. Assessment of Atmospheric Emissions
from Petroleum Refining - Appendix B: Detailed
Results. EPA-600/2-80-075C. (NTiS PB80-225279).
April 1980.
7. U.S. EPA. VOC Fugitive Emissions in Synthetic
Organic Chemicals Manufacturing Industry - Back
ground Information for Promulgated Standards. EPA-
450/3-80-033b. (NTIS PB84-105311). June 1982.
8. U.S. EPA. Fugitive Emission Sources of Organic
Compounds - Additional Information on Emissions,
Emission Reductions, and Costs. EPA-450/3-82-
010. (NTIS PB82-217126). April 1982.
9. Wilkins, G.E., J.H.E. Steeling, and S.A. Shareef.
Monitoring and Maintenance Programs for Pumps
and Valves in Petroleum and Chemical Processing
Plants: Costs and Effects on Fugitive Emissions.
Presented at 6th World Congress on Air Quality,
IUAPPA, Paris. May 1983.
10. Wilkins, G.E., and J.H.E. Stelling. Monitoring and
Maintenance Programs for Control of Fugitive Emis-
sions from Pumps and Valves in Petroleum and
Chemical Processing Plants. Presented at 1984
Industrial Pollution Control Symposium, ASME. New
Orleans, Louisiana. February 1984.
11. U.S. EPA. VOC Fugitive Emission Predictive Model-
User's Guide. EPA-600/8-83-029. (NTiS PB83-
241612). October 1983.
12. U.S. EPA. Evaluation of the Efficiency of Industrial
Flares. Background - Experimental Design - Facility.
EPA-600/2-83-070. (NTIS PB83-263723). August
1983.
13. Environmental Engineers' Handbook, Volume II: Air
Pollution. Liptak, B.G., ed. Chilton Book Company.
Radnor, Pennsylvania. 1974.
14. U.S. EPA. Technical Guidance for Control of Indus-
trial Process Fugitive Paniculate Emissions. EPA-
450/3-77-010. (NTIS PB272288). March 1977.
15. U.S. EPA. Identification, Assessment, and Control of
Fugitive Particulate Emissions. EPA-600/8-86/023.
(NTiS PB86-230083). May 1986.
16. U.S. EPA. Polymer Manufacturing Industry -
Background Information for Proposed Standards.
EPA 450/3-83-0198. (NTIS PB88-114996).Sep-
tember 1985.
17. U.S. EPA. Research and Development. Evaluation
of the Efficiency of Industrial Flares: H S Gas Mix-
tures and Pilot Assisted Flares. EPA 600/2-86-080.
(NTIS PB87-102372).September 1986.
18. Memorandum with attachments. Karen Catlett, U.S.
EPA, OAQPSto Carlos Nunez, U.S. EPA, AEERL,
Research Triangle Park, NC. November 1989.
19. U.S. EPA. OAQPS Control Cost Manual. EPA450/
3-90-006. (NTiS PB90-169954). January 1990.
20. Telecon. Sink, Michael, PES, Inc. with Yarrington,
Robert, Englehard Corporation, Edison, NJ. April
1990.
21. PES, Inc. Company data for the printing industry.
22. New Pumps Offer Greater Versatility. Chemical En-
gineering. Vol. 96, No. 2. February 1989.
23. U.S. EPA. Municipal Waste Combustors. Background
Information for Proposed Standards: Cost Proce-
dures. EPA/450/3-89/0263 (NTiS PB90-154840).
Research Triangle Park, NC. August 1989.
3-23
-------
Page Intentionally Blank
-------
Chapter 4
Design and Cost of HAP Control Techniques
4.1 Background
The procedures used to calculate the basic design and
operating variables of HAP control techniques are de-
scribed and illustrated in terms of commonly employed
design principles and values. For each technique, (a) a
brief description of how the technique works, (b) defini-
tions of input data required, (c) a step-by-step calcula-
tion procedure showing where each numberused in the
procedure originates and how it is to be used, and (d)
capital and annual cost methodologies utilizing the de-
sign variables calculated earlier are provided. The pro-
cedures described in this handbook will result in conser-
vatively designed control systems. In instances in which
less conservatively designed control systems might
achieve the target control level, more detailed calcula-
tion procedures requiring compound-specific data would
be needed. This level of specificity is beyond the scope
of this handbook.
The format of Chapter 4 in this revision differs from the
1986 Handbook. Sections 4.2 through 4.11 are de-
signed to be self-contained and to integrate the design
and cost information previously contained in separate
chapters. This arrangement is used to enable the reader
to obtain a study- type cost estimate (±30 percent) for a
given control device without having to extract specific
cost information from the general cost algorithm that,
was presented in the 1986 manual. The design method-
ologies have been updated where applicable to reflect
recent advances in calculation techniques. The cost
information has been updated for all techniques. The
cost of auxiliary equipment is common to all techniques
and therefore, the auxiliary equipment cost procedures
are provided in Section 4.12. The reader should note
that the cost data presented in some sections may need
to be escalated to reflect current costs. Table 4.12-1
contains appropriate escalation factors. Forpurposesof
this manual, cost information that is given in May 1988
dollars - January 1990 dollars is considered current and
does not need to be escalated. Cost information that is
more dated should be escalated to reflect current costs.
In working with this revision, the reader may note that
some control technique sections contain more informa-
tion than others. This level of detail is primarily a reflec-
tion of the popularity some control techniques enjoy
resulting in more available information for the more
popular techniques. For the most populartechniques, a
moredetailedcalculational approach was included where
possible and when appropriate for the design and cost
variables. This detail was included to incorporate re-
cently published information relevant to that technique,
and to provide a more detailed calculation^ approach
for the permit reviewer for those techniques he is more
likely to encounter. In addition, a given permit may have
multiple controls on a single emission stream. As an
example, a fixed bed carbon absorber using hot air as a
desorbent can be placed upstream of an incinerator.
The carbon absorber in effect increases the HAP con-
centration in the emission stream to the incinerator,
allowing for a more economical and possibly more
efficient operation. Such control techniques used in
tandem are not discussed perse, and the reader should
attempt to obtain specific information on these systems
before performing a design and cost analysis.
The data for the HAP emission stream to be controlled
are taken from the HAP Emission Stream Data Form
given in Chapter 2. In case of a permit evaluation,
however, these data should be supplied by the appli-
cant. The reviewer may wish to confirm the complete-
ness of the applicant's data by referring to Chapters 2
and 3.
The step-by-step calculation procedures are illustrated
for each control technique using data based on Emis-
sion Streams 1 through 8 described in Chapter 3, In
permit reviews, the calculated values are compared to
the values in the permit application to determine the
adequacy of the applicant's proposed design. Appendi-
ces C.Sthrough C.12contain blank calculation sheets to
use in applying the calculations described for each
control technique. Numbering of the calculation sheets
in these appendices is consistent with the section num-
bers to which they apply in this chapter.
4.2 Thermal incineration
Thermal incineration (Figure 4.2-1} is a widely used air
pollution control technique whereby organic vapors are
oxidized at high temperatures. Incineration (both ther-
mal and catalytic) is considered an ultimate disposal
method in that pollutant compounds in a waste gas
4-1
-------
Figure 4.2-1. Schematic diagram of a thermal incinerator.
Emission Source
Scrubber*
Combustion Air*
Supplementary Fuel
*>• Stack
'Required for specific situations.
stream are converted rather than collected. A major
advantage of incineration is that virtually any gaseous
organic stream can be incinerated safely and cleanly,
given proper design, engineering, installation, opera-
tion, and maintenance. Also, high (99 + percent) de-
struction efficiencies are possible with a wide variety of
emission streams. A methodology is provided in this
section to quickly estimate thermal incinerator design
and cost variables.
The approach taken in this section is somewhat less
detailed than the approach given in other EPA refer-
ences, but it allows for a relatively quick calculational
procedure. This approach enables the reader to obtain
a general indication of design and cost parameters
without resortingto more detailed and complex calcula-
tions. For a more detailed design procedure refer to the
OAQPS Control Cost Manual (OCCM)1.*
The two main types of thermal incinerators employed
arethermal recuperative and thermal regenerative. The
thermal recuperative type is the most common and
nearly always employs a heat exchanger to preheat a
gaseous stream prtorto incineration. Regenerative type
Incinerators are newer and employ ceramics to obtain a
more complete transfer of heat energy. The discussion
below focuses on the more common recuperative type
incineration. A detailed discussion of regenerative ther-
mal incinerators is provided in Reference 1.
The most important variables to consider in recupera-
tivethermal incinerator design are the combustion tem-
*Approprlato references are given at the end of each section.
perature and residence time because these design
variables determine the incinerator's destruction effi-
ciency. This efficiency also assumes that adequate
oxygen is present in the combustion chamber so that
combustion air is not requited. Further, at a given
combustion temperature and residence time, destruc-
tion efficiency is also affected by the degree of turbu-
lence, or mixing of the emission stream and hot combus-
tion gases, in the incinerator. In addition, halogenated
organics are more difficult to oxidize then unsubstituted
organics; hence, the presence of halogenated com-
pounds in the emission stream requires highertempera-
tures and longer residence times forcompleteoxidation.
Thermal incinerators can achieve a wide range of de-
struction efficiencies. This discussion focuses on effi-
ciencies of 98 to 99 + percent.
The incinerator flue gases are discharged at high tem-
peratures and contain valuable heat energy. Therefore,
a strong economic incentive exists for heat recovery.
Typical recovery methods include heat exchange be-
tween the flue gases and the emission stream and/or
combustion air and use of the available heat for process
heat requirements (e.g., recycling flue gases to the
process, producing hot water or steam, etc.). In most
thermal incinerator applications, the available enthalpy
in the flue gases is used for preheating the emission
stream. This discussion will be based on a thermal
incineration system where the emission stream is pre-
heated.
The incineration of emission streams containing organic
vapors with halogen or sulfur components may create
additional control requirements. For example, if sulfur
4-2
-------
and/or chlorine are present in the emission stream, the
resulting flue gas will contain sulfur dioxide (SO2) and/or
hydrogen chloride (HCI). Depending upon the concen-
trations of these compounds in the flue gas and the
applicable regulations, scrubbing may be required to
reduce the concentrations of these compounds. The
selection and design of scrubbing systems are dis-
cussed in Section 4.7.
In this subsection, the calculation procedure will be
illustrated using Emission Stream 1 described in Chap-
ter 3. Appendix C.3 contains worksheets for design and
cost calculations.
4.2.1 Data Required
The data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form and the
required HAP control as determined by the applicable
regulations.
If dilution air is added to the emission stream upon exit
from the process, the data that will be used in the
calculations are the resulting characteristics after dilu-
tion.
In the case of permit review for a thermal incinerator, the
data outlined below should be supplied by the applicant;
the calculations in this section will then be used to check
the applicant's values.
Thermal incinerator system variables at standard condi-
tions (77°F, 1 atm):
Reported destruction efficiency, DEreportesI, %
Temperature of the emission stream entering the
incinerator, T8,°F (if no heat recovery);
Tto, °F (if a heat exchanger is employed)
Combustion temperature, Te °F
. Residence time, tf, sec
Maximum emission stream flow rate, Qe, scfm
Fuel heating value (assume natural gas), hf, Btu/ib
Combustion chamber volume, Vc, ft3
Flue gas flow rate, Q,, scfm
4.2.2 Pretreatment of the Emission Stream:
Dilution Air Requirements
in HAP emission streams containing oxygen/air and
flammable vapors, the concentration of flammable va-
pors is generally limited to less than 25 percent of the
lower explosive limit (LEL) to satisfy safety requirements
imposed by insurance companies. (Note: The LEL for a
flammable vapor is defined as the minimum concentra-
tion in air or oxygen at and above which the vapor bums
upon contact with an ignition source and the flame
spreads through the flammable gas mixture). In some
cases, flammable vapor concentrations up to 40-50
percent of the LEL are permitted if on-line monitoring of
VOC concentrations and automatic process control and
shutdown are provided. The LELs of some common
organic compounds are provided in Table 4.2-1.
In general, emission streams treated by thermal incin-
eration are dilute mixtures of VOC and air, and typically
do not require further dilution. For emission streams with
oxygen concentrations less than 20 percent and heat
contents greater than 176 Btu/lb or 13 Btu/scf (in most
cases corresponding to flammable vapor concentra-
tions of approximately 25 percent of LEL), the calcula-
tion procedu re in this handbook assumes that dilution air
is required. (See Appendix B.2 for calculation of dilution
air requirements and Appendix C.2 for a calculation
worksheet.) Equation 4.2-1 can be used to obtain a
value for dilution air, Qd:
Qd =
[(h/h>1]Qa
(4.2-1)
where:
Qd « dilution air required, scfm
h8 =» heat content of emisston stream, Btu/scf
hd = desired heat content of emission stream,
< 13 Btu/scf
Note that this will change emission stream parameters.
Appendix B.2 provides the necessary equations to cal-
culate the changed stream parameters while Appendix
C.2 provides a corresponding worksheet.
4.2.3 Design Variables, Destruction Efficiency,
and Typical Operational Problems
Table 4.2-2 contains suggested combustion tempera-
ture and residence time values for thermal incinerators
to achieve a given destruction efficiency. Two sets of
values are shown inthetable, oneset for nonhalogenated
emission streams and another set for halogenated emis-
sion streams. The combustion temperature and residence
time values listed areconservative and assume adequate
mixing of gases in the incinerator and adequate oxygen
in the combustion chamber. The criteria in this table are
4-3
-------
Tab!* 4.2-1. Flammablllty Characteristics of Combustible Or-
ganic Compounds In Air **
Compounds Md.Wt, LEL,°%Vol. UEL*%Vol.
Methane
Ethane
Propane
n-Butano
n-Pentane
n-Hexane
n-Heptane
n-Octane
n-Nonana
n-Decane
n-Undeeane
n-Dodecane
n-Trldecane
n-Tetradecane
n-Pentadecano
n-Hexadecane
Ethykme
Propylene
Butene-1
cls-Buteno-2
Isobutylano
3-Methyl-Butene-1
Propadtene
1,3-Butadiene
Acetylene
Methylacetytene
Benzene
Toluene
Ethylbonzene
o-Xytene
m-Xytene
p-Xylene
Cumene
p-Cumene
Cydopropane
Cydobutano
Cydopentane
Cydohexane
Ethyteydobutane
Cydoheptane
Methylcydohexane
Ethylcydopentane
Ethyteydohexane
Methyl alcohol
Ethyl alcohol
n-Propyl alcohol
n-Butyl alcohol
n-Amyl alcohol
n-Hexyl alcohol
Dimethyl ether
Diothyl ether
Ethyl propyl ether
Diisopropyl ether
Acetaldehyde
Proplonaldehyde
Acetone
Methyl ethyl ketone
Methyl propyl ketone
Dlethyl ketone
Methyl butyl ketone
16.04
30.07
44.09
58.12
72.16
86.17
100.20
114.28
128.25
142.28
156.30
170.33
184.36
208.38
212.41
226.44
28.05
42.08
56.10
56.10
56.10
70.13
40.06
54,09
2.5
1.7
78.11
92.13
106.16
106.16
106.16
106.16
120.19
134.21
42.08
56.10
70.13
84.16
84.16
98.18
98.18
98.18
1 12,21
32.04
46.07
60.09
74.12
88.15
102.17
46.07
74.12
88.15
102.17
44.05
58.08
58.08
72.10
86.13
86.13
100.16
5.0
3.0
2.1
1.8
1.4
1.2
1.05
0.95
0.85
0.75
0.68
0.60
0.55
0.50
0.46
0.43
2.7
2.4
1.7
1.8
1.8
1.5
2.6
2.0
100
1.3
1.2
1.0
1.1
1.1
1.1
0.88
0.85
2.4
1.8
1.5
1.3
1.2
1/i
1.1
1,1
0.95
6.7
3.3
2.2
1.7
1.2
1.2
3.4
1.9
1.7
1.4
4,0
2.9
2,6
1.9
1.6
1.6
1.4
15.0
12.4
9.5
8,4
7,8
7,4
6.7
3.2
2.9
5,6
36
11
9.7
9.7
9.6
9.1
12
7.0
7.1
6.7
6.4
6.4
6.6
6.5
6.5
10.4
7.8
7.7
6,7
6.7
6.7
6.6
36
19
14
12
10
7.9
27
36
9
7.9
36
14
13
10
8.2
8.0
not the only conditions for achieving the specified de-
struction efficiencies. For a given destruction efficiency,
HAP emission streams may be incinerated at lower
temperatures with longer residence times. However, the
values provided in Table 4.2-2 reflect temperatures and
residence times found in industrial applications. Based
on the required destruction efficiency (DE), select ap-
propriate values for T0 and tr from Table 4.2-2. For more
information on temperature requirements vs. destruc-
tion efficiency, consult Appendix D of Reference 6.
Since the performance of a thermal incinerator is highly
related to the combustion chamber and outlet gas tem-
perature, any thermal incinerator system used to control
HAPs should be equipped with it continuous tempera-
ture monitoring system. Most vendors routinely equip
thermal incinerators with such a system.4 However,
some older units may not have a continuous tempera-
ture monitoring system. Inthiscase, the permit reviewer
should request a retrofit installation of such a system. To
obtain an indication of the combustion chamber volume
correspondingtoagiven residence time, referto Section
4.2.4.3.
In addition to temperature and residence time, correct
mixing of the gas streams is essential for proper opera-
tion. Unfortunately, mixing cannot be measured and
quantified as a design variable. Typically, mixing is
improved and adjusted in an incinerator after start-up. It
is ultimately the responsibility of the user to ensure
correct operation and maintenance of a thermal incin-
erator after start-up.
In a permit evaluation, if the reported values for T0 and
trare sufficient to achieve the required DE (compare the
applicant's values with the values from Table 4.2-2),
proceed with the calculations. If the reported values for
Te and tr are not sufficient, the applicant's design is
unacceptable. The reviewer may wish to use the values
for T0 and tf from Table 4.2-2. (Note: If DE is less than
98 percent, obtain information from the literature and
incinerator vendors to determine appropriate values for
T0andtr.)
Reference 1.
Reference 2,
LEL—lower explosive limit
DEL—upper explosive limit.
14.2-3 contains theoretical combustion
temperatures for 99.99 percent destruction efficiencies
for various compounds with a residence time of 1 sec-
ond. Note that the theoretical temperatures in Table 4.2-
4-4
-------
Table 4.2-2. Thermal incinerator System Design Variables*
Required
Destruction
Efficiency
DE(%)
98
99
Nonhalogenated Stream
Combustion Residence
Temperature Time
TjfF) tr(sec)
1,600 0.75
1.800 0.75
Haloaenated Stream
Combustion Residence
Temperature Time
TC(°F) t,{sec)
2,000 1.0
2,200 1.0
•Reference 3,
3 are considerably lower than those given in Table 4.2-
2, This difference is because the values in Table 4.2-3
are theoretical values for specific compounds, while the
values given in Table 4.2-2 are more general values
designed to be applicableto a variety of compounds and
are conservatively high. Table 4.2-3 is provided to
indicate that certain specific applications may not re-
quire as high a combustion chamber temperature as
those given in Table 4.2-2. Since the values given in
Table 4.2-3. Theoretical Combustion Temperatures Required
for 99.99 Percent Destruction Efficiencies*
Compound
Combustion
Temperature (°F)
Residence
Time (Sec)
Acrylonitrile
Allyl chloride
Benzene
Chlorobenzene
1 ,2-dichIoroe thane
Methyl chloride
Toluene
Vinyl chloride
1,344
1,276
1,350
1,407
1,368
1,596
1,341
1,369
1
1
1
1
1
1
1
1
* Reference 1.
Table 4.2-3 are theoretical, they may not be as accurate
as the values given in Table 4.2-2.
As a practical matter, a specific temperature to provide
a specific destruction efficiency cannot be calculated a
priori. Typically, incinerator vendors can provide general
guidelines for destruction efficiency based on extensive
experience. Tables 4.2-2 and 4.2-3 are presented to
show a range of difference between theoretical and
general values. In essence, these tables are used as a
substitute for design equations relating destruction effi-
ciency to equipment parameters, since design equa-
tions are seldom used in hand analysis.
Most operational problems with thermal incinerators
concern the burner. Typical problems encountered in-
clude low burner firing rates, poor fuel atomization (oil-
fired units), poor air/fuel ratios, inadequate air supply,
and quenching of the burner flame.5 These problems
lead to lower destruction efficiencies for HAPs. Symp-
toms of these problems include obvious smoke produc-
tion or a decrease in combustion chamber temperature
as indicated by the continuous monitoring system. If a
thermal incinerator system begins to exhibit these symp-
toms, the facility operator should take immediate action
to correct any operational problems.
4.2.4 Determination of Incinerator Operating
Variables
4.2.4.1 Supplementary Fuel Requirements
Supplementary fuel is added to the thermal incinerator
to attain the desired combustion temperature (Tc). For a
given combustion temperature, the quantity of heat
needed to maintain the combustion temperature in the
thermal incinerator is provided by: (a) the heat supplied
from the combustion of supplementary fuel, (b) the heat
generated from the combustion of hydrocarbons in the
emission stream, (c) the sensible heat contained in the
emission stream as it leaves the emission source, and
(d) the sensible heat gained by the emission stream
through heat exchange with hot flue gases,
in general, emission streams treated by thermal incin-
eration are dilute mixtures of VOC and air, and typically
do not require additional combustion air. For purposesof
this handbook, ft is assumed that the streams treated will
have oxygen contents greater than 20 percent in the
waste gas stream, which Is typical of the majority of
cases encountered. Use the following simplified equa-
tion for dilute streams to calculate supplementary heat
requirements (based on natu rat gas):
0,--
D9 (Q
(1 .1 Te - Th, - 0.1 Tr) -
where:
Qr =
Do =
Df =
Q8 =
Gp,,. =
(4.2-2)
natural gas flow rate, scfm
density of flue gas stream, Ib/scf (usually
0.0739 Ib/scf)
density of fuel gas, 0.0408 Ib/scf for meth-
ane
emission stream flow rate, scfm
meanheatcapacityofairbetweenToandTr,
Btu/lb-0F (See Table C.8-1)
4-5
-------
'h*
combustion temperature, °F
emission stream temperature after heat re-
covery, °F
reference temperature, 77°F
heat content of flue gas, Btu/lb
lower heating value of natural gas, 21,600
Btu/lb
Calculate TN using the following expression if the value
^ is not specified:
(HR/1QO)T0 + [1-(HR/100)]T8
Q(8 =
(4.2-3)
where:
HR - heat recovery in the exchanger, %
T. - temperature of emission stream, °F
Assume a value of 70 percent for HR if no other informa-
tion is available.
The factor 1.1 in Equation 4.2-2 is to account for an
estimated heat loss of 10 percent in the incinerator.
Supplementary heat requirements are based on maxi-
mum emission stream flow rate, and hence will lead to
a conservative design.
Using Equation 4,2
Since the emission
ares
D. - 0.0739 lb/scf;;
D, » 0.0405 Ib/sef
Qft -15,000 scfm
CP..S 0,269
eft^^
.
TT
T!
18Q0?F
77°f=
i, - 21,600 Btu/lb;
£ ,(0.073Q)M;
4.2.4.2 Flue Gas Flow Rate
Flue gas is generated as a result of the combustion of
supplementary fuel and the emission stream. Use the
following equation to calculate flue gas flow rate:
where:
Qf9 = flue gas flow rate, scfm
Q8 = emission stream flow rate, scfm
Q, = natural gas flow rate, scfm
Qd = dilution air requirement, scfm
4,2.4.3 Combustion Chamber Volume
To obtain an indication of the residence time, the com-
bustion chamber volume (Vo) should be calculated. First,
the emission stream flow rate of actual conditions should
be calculated from Equation 4.2-4:
= CL[(Te + 460y537]
(4.2-4)
where:
Qfga = actual flue gas flow rate, acfm
Q(g = flue gas flow rate, scfm (from Eq. 4,2.-3)
The combustion chamber volume, Vc, is determined
from the residence time trfrom Table 4.2-2 and Q^,
obtained above.
vc = [(Qlaa/60)tr]x1.05 (4.2-5)
The factor of 1.05 is used to account for minor fluctua-
tions in the flow rate, and follows industry practice.
4.2.5 Evaluation of Permit Application
Using Table 4.2-4, compare the results from the calcu-
lations and the values supplied by the permit applicant.
The calculated values in the table are based on the
example. The flue gas flow rate, Qfg is determined from
the emission stream flow rate (Q), dilution air require-
ment (Qa), and supplementary fuel requirement (Q().
Therefore, any differences between the calculated and
4-6
-------
Table 4.2-4. Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Thermal
Incineration
Calculated
Value Reported
(Example Case)* Value
Continuous monitoring of
combustion temperature yes
Supplementary fuel flow rats, Q, 163 scfm
Dilution air flow rate, Qa 0
Flue gas flow rate, Q, g 15,200 scfm
Combustion chamber volume, VB 840ft2
•Based on Emission Stream 1.
Table 4.2-5. Costs for Thermal Incinerators*
Thermal Incinerator
Cost
TO (April 1988$)
•Reference 1.
Heat Exchanger Efficiency,
HR
TC = 10,294 Q ,9«*»
TC = 13,149 Q,,0**®
TC = 17,056 Q,/-2682
Tc-ai^aQ,,0*600
HR = 0%
HR » 35%
HR = 50%
HR - 70%
reported values for Q,g will be dependent on the differ-
ences between the calculated and reported values for Qd
and Qr If the calculated values for Qd and Q differ from
the reported values for these variables, the differences
may be due to the assumptions involved in the calcula-
tions. Therefore, further discussions with the permit
applicant will be necessary to find out about the details
of the design and operation of the proposed thermal
incinerator system.
If the calculated values and the reported values are not
different, then the design and operation of the proposed
thermal incinerator system may be considered appropri-
ate based on the assumptions used in this handbook.
4,2.6 Capital and Annual Costs of Thermal
Incinerators
Procedures for estimating the capital and annual costs
of a thermal-recuperative type incinerator are presented
in this section.
4.2.6.1 Thermal Incinerator Capital Costs
The capital cost of a thermal incinerator is estimated as
the sum of the equipment cost and the installation cost.
The equipment cost is a function of the incinerator
equipment cost and the cost of auxiliary equipment. For
thermal incinerators auxiliary equipment includes the
cost of ductwork and dampers. Equations to estimate
the equipment cost of thermal incinerators based on Q,g
and heat exchanger efficiency are provided in Table 4.2-
5. These costs include instrumentation. The equations
given in Table 4,2-5 are to be used for flow rates from
500 scfm to 50,000 scfm and will yield equipment costs
in April 1988 $. These equations should not be extrapo-
lated outside this range. Refer to Section 4.12 to obtain
costs of auxiliary equipment. The factors given in Table
4.2-6 are then used to obtain the purchased equipment
cost (PEC).
After obtaining the purchased equipment cost, the total
capital cost is estimated using the factors presented in
Table 4.2-6.
4.2.6.2 Thermal Incinerator Annual Costs
The total annual cost (TAG) of a thermal Incinerator
consists of direct and indirect annual costs. Table 4.2-8
contains the appropriate factors to estimate total annual
costs, while the discussion below details the information
necessary to obtain a TAG estimate.
Direct Annual Cost. These costs include fuel,
electricity, operating and supervisory labor, and
maintenance labor and materials.
Fuel usage is calculated in Section 4.2.4.1. Once this
value is calculated, multiply it by 60 to obtain scfh and
multiply this by the annual operating hours to obtain the
annual fuel usage. Then simply multiply the annual fuel
usage by the cost of fuel provided in Table 4.2-8 to obtain
this annual cost.
4-7
-------
Table 4.2-6. Capital Cost Factors for Thermal Incinerators"
Cost Item
Factor
Direct Costs
Purchased equipment costs
Incinerator (TC) + auxiliary equipment, EC
Instrumentation*
Sales taxes
Freight
Purchased Equipment Cost, PEC
Direct installation costs
Foundations & supports
Handling & erection
Electrical
Piping
Insulation for ductwork0
Painting
Direct Installation Cost
Site preparation
Buildings
Total Direct Cost, DC
Indirect Costs (Installation)
Engineering
Construction and field expenses
Contractor fees
Start-up
Performance test
Contingencies
Total Indirect Cost, (1C)
Total Capital Costs (TOO)« DC + 1C
As estimated, EC
0.10 EC
0.03 EC
0.05 EC
PEC =1.18 EC
0.08 PEC
0.14 PEC
0.04 PEC
0.02 PEC
0.01 PEC
0.01 PEC
0.30 PEC
As required, SP
As required, Bid;).
1.30 PEC + SP + Bldg.
0.10 PEC
0.05 PEC
0.10 PEC
0.02 PEC
0.01 PEC
0.03 PEC
0.31 PEC
1.61 PEC + SP + Bldg.
•Reference 1.
11 Instrumentation and controls often furnished with the incinerator, and thus often included in the EC.
<* If ductwork dimensions have been established, cost may be estimated based on $10 to $12/ff of surface for field application. Fan housings and
stacks may also be Insulated.
Electricity costs are associated primarily with the fan
needed to move the gas through the incinerator. Use
Equation 4.2-6 to estimate the power requirements for a
fan, assuming a fan motor efficiency of 65 percent and
a fluid specific gravity of 1.0. The fan is assumed to be
installed downstream of the incinerator.
1.81x10-*(Qfaa)(P)(HRS)
(4.2-6)
where:
provided in Table 4.2-8. Supervisory costs are esti-
mated as 15 percent of operator labor costs.
Maintenance labor requirements are estimated as 0.5
hours per 8-hour shift with a slightly higher labor rate
(see Table 4.2-8) to reflect increased skill levels. Main-
tenance materials are estimated as 100 percent of
maintenance labor. The wage rates provided in Table
4.2-8 reflect typical values. A given situation may have
wage rates different from these values.
:fs,»
power needed for fan, kWh/yr
actual emission stream flow rate, acfm
system pressure drop, in. H,O (from Table
4.2-9)
HRS « operating hours per year, hr/yr
Operating labor requirements are estimated as 0.5
hours per 8-hour shift. The operator labor wage rate is
Indirect Annual Costs. These costs include the capital
recovery cost, overhead, property taxes, insurance, and
administrative charges. The capital recovery cost is
based on an estimated 10-year equipment life, while
overhead, property taxes, insurance, and administrative
costs are percentages of the total capital cost. Table 4.2-
8 contains the appropriate factors for these costs.
4-8
-------
Table 4.2-7. Example Case Capital Costs
Cost Item
Factor
Cost ($)
Direct Costs
Purchased equipment costs (PEC)
Incinerator (TC) + auxiliary equipment, EC
Instrumentation
Sales tax
Freight
Purchased Equipment Cost
Direct Installation costs
Foundation and supports
Handling and erection
Electrical
Piping
Insulation for ductwork
Painting
Direct Installation Cost
Site preparation
Building
Total Direct Cost, DC
Indirect Costs
Included
0.03
0.05
1.08
0.08 PEC
0.14 PEC
0.04 PEC
0.02 PEC
0.01 PEC
0.01 PEC
0.30 PEC
$247,000
0
7,400
' 12.300
$267,000
$21,400
37,400
10,700
8,300
2,700
2,700
$80,200*
As required, SP
As required, Bldg.
$267,000 + $80,200 + SP + Bldg.
Engineering
Construction and field expense
Contractor fees
Start-up
Performance test
Contingencies
Total Indirect Cost, 1C
0.10 PEC
0.05 PEC
0.10 PEC
0,02 PEC
0.01 PEC
0.03 PEC
0.31 PEC
$26,700
13,400
26,700
5,300
2,700
8,000
$82,800
Total Capital Cost
Total Capital Cost (TCC) = $430,000 + SP + Bldg.
= DC + IC
= $267,000+$80,200+$82,800+ SP +Bldg.
' In this and subsequent tables, added values may vary from "factor" values due to rounding.
Table 4.2-8. Annual Cost Factors for Thermal Incinerators*
Table 4.2-9. Typical Pressure Drops for Thermal Incinerators**
Cost tern
Factor
Direct Annual Costs. DAC1*
Utilities
Fuel (natural gasf
Electricity
Operating Labor
Operator
Supervisor
Maintenance
Labor
Material
Indirect Annual Cost, IAC
Overhead
Administrative 2% of TCC
Property taxes
Insurance
Capital recovery
$3.30/1,000 ft?
$0.059/kwh
$12.96/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
0.60 (Operating labor and
maintenance costs)
1% of TCC
1% of TCC
0.1628 (TCC)
Equipment Type
Thermal incinerator
Heat exchanger
Heat exchanger
Heat exchanger
Heat Recovery
(HR)
0
35
SO
70
Pressure Drop
P ( in. H20)
4
4
8
15
* Reference 1,
bThe pressure drop is calculated as the sum of the Incinerator and
heat exchanger pressure drops.
" Reference 1.' Costs given above are typical, not definitive,
"1988$.
" The fuel cost may vary from this value. If possible, obtain a value
more appropriate for the situation.
dThe capital recovery factor is calculated as: i(1+!)"/(1+i)° -1
where: i = interest rate,
10 percent
n = equipment life,
10 yrs
4-i
-------
Example Case
Direct Annual: Costs
Fuel usage «163 scftn (60 min/hr) (6000 hr/yr)
* 58.7x1 Q
Fuel cost
1,000 ft
3
Electricity usage is estimated from Eq, 4,2-6 and
Table 4,2-6;
F0 - 131 x 104 (15,200) (4+1$) (6000 hr/yr)
«31,4x104kWfVyr .- - -
Electricity cost - $0.069(31.4x10*) '
* $18,500 •'
Operating labor costs are estimated asr
1(0.5 hr/shift)/{8 hr/shift)] 6000 hrs/yr * 575 hr/y'r '
375 hr/yr ($1 2.96/hr) - $4,900 ,-.
Supervisory costs are taken as 15 percent of this
value or $700.
Maintenance labor costs are estimated as:
1(0.5 hr/shift}/(8 hr/shift)] 6000 hrs/yr* 375 hr/yr
37S hr/yr ($14.20/hr) « $5,300 ' *
Maintenance materials are taken as too percent of
this value, or $5,300. *'
Total Direct Costs » $1 94,000 ± $1 8,500 *
$4,900 4- $700 + $5,300 +
, $5,300 « $229,000
Indirect Annual Costs
These costs are obtained from the factors presented
!nTabfe4,2-7,andtheexamp!eca$ecosts estimated
above. , - - , ••
Overhead
Administrative
Property taxes
Insurance
Capital recovery
* 0,60 ($4,900 * $700 +
$53004- $5,300} « $9,700
- 0,02 ($430,000) - $8,600
= 0.01 ($430,000) =$4,300
» 0.01 ($4&KOOO) - $4,300
« 0,1628 ($430,000 }•» $70*000
Total Indirect Costs « $9,700 +$8JOO + $4,300 +
$4,300 + $70,000 » $96,900
Total Annual Costs «= $229,000 4- $96,900
» $326,000
4.2.7 References
1. U.S. EPA. OAQPS Control Cost Manual. Fourth
Edition, EPA 450/3-90-006 (NTIS PB90-169954).
January 1990.
2. Handbook of Chemistry and Physics, 60th ed.,
Cleveland: The Chemical Rubber Company, 1980.
3. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. EPA 625/6-86-014. Cin-
cinnati, OH. September 1986 (NTIS PB91 -228809).
4. PES, Inc., Research Triangle Park, NC. Company
data for the evaluation of continuous compliance
monitors.
5. Memorandum with attachments. Carlos Nunez, U.S.
EPA, AEERL, to Michael Sink, PES. Research
Triangle Park, NC. October 1989.
6. U.S. EPA. Handbook: Guidance on Setting Permit
Conditions and Reporting Trial Bum Results. EPA
625/6-89-019. Cincinnati, OH. January 1989.
4.3 Catalytic Incineration
Catalytic Incineration (Figure 4.3-1) is an air pollution
contro j technique whereby VOCs in an emission stream
are oxidized with the help of a catalyst. A catalyst is a
substance that accelerates the rate of a reaction at a
given temperature without being appreciably changed
during the reaction. Catalysts typically used for VOC
incineration include platinum and palladium; other for-
mulations are also used, including metal oxides for
emission streams containing chlorinated compounds.
The catalyst bed (or matrix) in the incinerator is generally
a metal mesh-mat, ceramic honeycomb, or other ce-
ramic matrix structure designed to maximize catalyst
surface area. The catalysts may also be in the form of
spheres or pellets. Before passing through the catalyst
bed, the emission stream is preheated, if necessary, in
a natural gas-fired preheater and/or via heat exchange
with the flue gas.
Recent advances in catalysts have broadened the appli-
cability of catalytic incineration. Catalysts now exist that
are relatively tolerant of compounds containing sulfuror
chlorine. These new catalysts are often single or mixed
metal oxides and are supported by a mechanically
strong carrier. A significant amount of effort has been
directed towards the oxidation of chlorine-containing
VOCs. These compounds are widely used as solvents
and degreasers, and are often encountered in emission
streams. Catalysts such as chrome/alumina, cobalt ox-
ide, and copper oxide/manganese oxide have been
demonstrated to control emission streams containing
chlorinated compounds. Platinum-based catalysts are
often employed for control of sulfurcontaining VOCs but
are sensitive to chlorine poisoning.
Despite catalyst advances, some compounds simply do
not lend themselves well to catalytic oxidation. These
include compounds containing atoms such as lead,
arsenic, and phosphorous. Unless the concentration of
such compounds is sufficiently low, or a removal system
is employed upstream, catalytic oxidation should not be
considered in these cases.
The performance of a catalytic incinerator is affected by
several factors including: (a) operating temperature, (b)
space velocity (reciprocal of residence time), (c) VOC
composition and concentration, (d) catalyst properties,
and as mentioned above, (e) presence of poisons/
4-10
-------
Figure 4.3-1. Schematic diagram of a catalytic Incinerator system.
Emission Source
Catalytic Incinerator
Combustion Air* •
Supplementary Fuel
Preheater
Catalyst Bed
Dilution Air*
Stack
Heat Exchanger
(Optional)
'Required for specific situations.
inhibitors in the emission stream. In catalytic incinerator
design, the important variables are the operating tem-
perature at the catalyst bed inlet, the temperature rise
across the catalyst bed, and the space velocity assum-
ing adequate oxygen is present. The operating tempera-
ture for a particular destruction efficiency is dependent
on the concentration and composition of the VOC in the
emission stream and the type of catalyst used.
Space velocity is defined as the volumetric flow rate of
the combined gas stream (i.e., emission stream+supple-
mental fuel + combustion air) entering the catalyst bed
divided by the volume of the catalyst bed. As such,
space velocity alsodepends on the typeof catalyst used.
At a given space velocity, increasing the operating
temperature at the inlet of the catalyst bed increases the
destruction efficiency. At a given operating temperature,
as space velocity is decreased (i.e., as residence time in
the catalyst bed Increases), destruction efficiency in-
creases. Catalytic incinerators can achieve overall HAP
destruction efficiencies of about 95 percent with space
velocities in the range of 30,000 - 40,000 hr1 using
precious metal catalysts, or 10,000 -15,000 hr -1 using
base metal catalysts.9 However, greater catalyst vol-
umes and/or higher temperatures required for higher
destruction efficiencies (i.e., 99 percent) may make
catalytic incineration uneconomical. This discussion will
be based on HAP destruction efficiencies of 95 percent.
The performance of catalytic incinerators is sensitive to
pollutant characteristics and process conditions (e.g.
flow rate fluctuations). In the following discussion, it is
assumed that the emission stream is free from poisons/
inhibitors such as phosphorous, lead, bismuth, arsenic,
antimony, mercury, iron oxide, tin, zinc, sulfur, and
halogens. (Note: some catalysts can handle emission
streams containing halogenated compounds as dis-
cussed above.) It is also assumed that the fluctuations
in process conditions (e.g., changes in VOC content) are
kept to a minimum.
After oxidation of the emission stream, the energy in the
flue gases leaving the catalyst bed may be recovered in
several ways including: (a) use of a recuperative heat
exchanger to preheat the emission stream and/or com-
bustion air, or (b) by use of the available energy for
process heat requirements (e.g., recycling flue gases to
the process, producing hot water or steam, etc.). In
recuperative heat exchange, only a limited preheat is
possible due to the temperature rise across the catalyst
bed as a result of the combustion of VOC in the emission
stream. High preheat temperatures accompanied by a
temperature increase across the catalyst bed lead to
high temperatures at the catalyst bed, causing the
catalyst bed to overheat and eventually lose its activ-
ity.5'8
The following discussion will be based on fixed bed
catalytic incinerator systems with no heat recovery and
with recuperative heat exchange (i.e., preheating the
emission stream). Throughout this section, it is as-
sumed that adequate oxygen is present in the emission
stream so that combustion air is not required (i.e. O2^20
percent). The calculation procedure will be illustrated
using Emission Stream 2 described in Chapter 3. Ap-
pendix C.4 provides worksheets for calculations.
4.3.1 Data Required
The data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form and the
4-11
-------
required HAP control as determined by the applicable
regulations.
Maximum flow rate, Q ^;
Temperature, T^-: •
.'.
Based on the rttr^'Tieiu1li.J^^§:^^feilli
'' "; •'' .v.-:-:;:-::-:-;.;,/*-;.;.^-^'/1 '^;:;<.^^;:^y::^^:.::l:;yv:;:;^:<;:;^;:^:X;;;;:;;:;:;:::;:;;:>;;.;.^
S_ „ .v--... •., _ -^. • -,»j '^- ^M^KpillilP^^^Kll^i
mmK
If dilution air is added to the emission stream upon exit
from the process, the data that will be used in the
calculations are the resulting characteristics after dilu-
tion.
In the case of a permit review for a catalytic incinerator,
the following data should be supplied by the applicant.
The calculations in this section will then be used to check
the applicant's values.
Catalytic incineration system variables at standard
conditions (77°F, 1 atm):
Reported destruction efficiency, DEreport8d, %
Temperature of the emission stream entering the
incinerator, T,, °F (if no heat recovery); Tta, °F (if
emission stream is preheated)
Temperature of flue gas leaving the catalyst bed,
J op
'co' r
Temperature of combined gas stream (emission
stream + supplementary fuel combustion prod-
ucts) entering the catalyst bed, Td,°F
Space velocity through catalyst bed, SV, hr -1
Supplementary fuel gas flow rate, Q(, scfm
Row rate of combined gas stream entering the
catalyst bed, Q^, scfm (Note that if no supple-
mentary fuel is used (i.e., Q,=0) the value of Q^
will equal the emission stream flow rate)
Dilution airflow rate, Qd, scfm
Catalyst bed requirement, V^, ft3
Fuel heating value, h(, Btu/lb
4.3.2 Pretreatment of the Emission Stream:
Dilution Air Requirements
In general, catalytic incineration is applied to dilute
emission streams. If emission streams with high VOC
concentrations (i.e., heat content above 10 Btu/scf for air
+• VOC mixtures and above 15 Btu/scf for inert •*• VOC
mixtures) are treated by catalytic incineration, they may
generate enough heat upon combustion to deactivate
the catalyst. Therefore, dilution of the emission stream
with air is necessary to reduce the concentration of the
VOCs. These cut-off values are taken from a previous
EPA publications.1
Typically, the concentration of flammable vapors in HAP
emission streams containing air is limited to less than 25
percent of the LEL (corresponding to a heat content of
176 Btu/lb or 13 Btu/scf) for safety requirements. To
convert from Btu/lb to Btu/scf, multiply Btu/lb by the
density of the emission stream at standard conditions,
0.0739 Ib/scf. Table 4.2-1 contains a listing of LELs for
common organic compounds. In orderto meet the safety
requirements andtoprevent damage to the catalyst bed,
it is assumed in this handbook that catalytic incineration
is applicable if the heat content of the emission stream
(air + VOC) is less than or equal to 10 Btu/scf. For
emission streams that are mixtures of inert gases and
VOC (i.e., containing no oxygen), ft is assumed that
catalytic incineration is applicable if the heat content of
the emission stream is less than or equal to 15 Btu/scf.1
Otherwise, dilution air will be required to reduce the heat
content to levels below these cut-off values (i.e., 10 and
15 Btu/scf). For emission streams that cannot be char-
acterized as air+VOC or inert+VOC mixtures, apply the
more conservative 10 Btu/scf cut-off value for determin-
ing dilution air requirements. The dilution air require-
ments can be calculated from Equation 4.3-1 given
below which is also provided in Appendix B.2. Note that
dilution air will change the emission stream parameters.
Appendix B.2 provides the necessary equations to cal-
culate the stream parameters, while Appendix C.2 pro-
vides a blank worksheet.
(4.3-1)
where:
J=
dilution air requirement, scfm
heat content of emission stream, Btu/scf
desired heat content of emission stream,
Btu/scf
4.3.3 Design Variables, Destruction Efficiency,
and Typical Operational Problems
Table 4.3-1 presents suggested values and limits forthe
design variables of a fixed bed catalytic incinerator
system to achieve a 95 percent destruction efficiency.
Most catalytic incinerators currently sold are designed to
achieve an efficiency of 95 percent.9 In selected in-
stances, catalytic incinerators can achieve efficiencies
on the order of 98 to 99 percent, but general guidelines
for space velocities at these efficiencies could not be
found. For specific applications, othertemperatures and
space velocities may be appropriate depending on the
4-12
-------
type of catalyst employed and the emission stream
characteristics (i.e., composition and concentration).
For example, the temperature of the flue gas leaving the
catalyst bed may be lower than 1 .OOO^F for emission
streams containing easily oxidized compounds and still
achieve the desired destruction efficiency. (See Refer-
ence 3 or 4, for data on temperatures typically required
for specif to destruction efficiency levels for several com-
pounds.)
The destruction efficiency for a given compound may
vary depending on whether the compound is the only
VOC in the emission stream, or it is part of a mixture of
VOCs.4The destruction efficiency fora given compound
in different VOC mixtures may also vary with mixture
composition. (See Reference 4 for compound-specific
destruction efficiency data for two different VOC mix-
tures.) Based on the required destruction efficiency
(DE), specify the appropriate ranges for Tol, Teo, and
select the value for SV from Table 4.3-1.
The performance of a catalytic incinerator system de-
pends greatly on both the temperature and pressure
differential across the catalyst bed assuming a correct
operating temperature at the catalyst bed inlet. The
temperature differential or rise across the catalyst bed is
the fundamental performance indicator for a catalytic
incinerator system, as it directly indicates VOC oxida-
tion. The pressure differential across the catalyst bed
serves as an indication of the volume of catalyst present.7
The pressure drop decreases overtime as bits of cata-
lyst become entrained in the gas stream. To ensure
proper performance of the system, ft is recommended
that both the temperature rise across the catalyst bed
and the pressure drop across the catalyst bed be moni-
tored continuously. Currently, most vendors routinely
include continuous monitoring of these parameters as
part of catalytic incinerator system package.7 However,
some older units may not be so equipped; in this case the
reviewer should ensure the incinerator is equipped with
both continuous monitoring systems.
In addition to catalyst loss, catalyst deactivation and
blinding occur over time and limit performance. Catalyst
deactivation is caused by the presence of materials that
react with the catalyst bed. Blinding is caused by the
accumulation of paniculate matter on the catalyst bed
surface which decrease the effective surface area of the
catalyst.6-9 For these reasons, vendors recommend re-
placing the catalyst every two to three years. Symptoms
of catalyst loss include a decrease in pressure drop
across the catalyst bed and a decrease in the tempera-
ture rise across the catalyst bed. Symptoms of deactiva-
tion and blinding include a decrease in the temperature
rise across the catalyst bed. If a catalytic incinerator
system exhibits these symptoms, the facility should take
immediate action to correct these operational problems.
In a permit evaluation, determine if the reported values
for Tc)> Tco, and SV are appropriate to achieve the
required destruction efficiency by comparing the
applicant's values with the values in Table 4.3-1. How-
ever, it is important to keep in mind that the values given
in Table 4.3-1 are approximate and a given permit may
Table 4.3-1. Catalytic Incinerator System Design Variables9
Required
Destruction
Efficiency
DE(%)
98
.98-99
Temperature
at the Catalyst
Bed Inlet*
•y> F)
600
600
Temperature
at the Catalyst
Bed Outlet*
TCO(°F)
1,000-1,200
1,000 - 1,200
Space
Velocity
SV (hr •')
Base Metal
10,000 - 15,000°
-------
differ slightly from these values. The reported value for
T,,, should equal or exceed 600°F in order to obtain an
adequate initial reaction rate. To ensure that an ad-
equate overall reaction rate can be achieved to give the
desired destruction efficiency without damaging the
catalyst, check whether Tco falls in the interval 1,000° -
1,200°F. (This temperature range is somewhat higher
than the range provided in Reference 5 to ensure a high
HAP destruction efficiency). Then check if the reported
value for SV is equal to or less than the value in Table
4.3-1. If the reported values are appropriate, proceed
with the calculations. In some cases it may be possible
to achieve the desired destruction efficiency at a lower
temperature level. If a permit applicant uses numbers
significantly different from Table 4.3-1, documentation
indicating the rationale for this variance should accom-
pany the application. In this case, the permit values
should take precedence over those values given in
Table4.3-1. Otherwise.the applicant's design is consid-
ered unacceptable. In such a case, the reviewer may
then wish to use the values in Table 4.3-1.
4.3.4 Determination of Incineration Operating
Variables
4.3.4.1 Supplementary Fuel Requirements
Supplementary fuel is added to the catalytic incinerator
system to provide the heat necessary to bring the
emission stream up to the required catalytic oxidation
temperature (T^) for the desired level of destruction
efficiency. ForagivenT , the quantity of supplementary
heat needed is provided by: (a) the heat supplied from
the combustion of supplementary fuel, (b) the sensible
heat contained in the emission stream as it enters the
catalytic incinerator system, and (c) the sensible heat
gained by the emission stream through heat exchange
with hot flue gases. If recuperative heat exchange is not
practiced at a facility, then item (c) will be zero.
Since emission streams treated by catalytic incineration
are dilute mixtures of VOC and air, they typically do not
require additional combustion air. For purposes of this
handbook, it is assumed that no additional combustion
aids required if the emission stream oxygen content (O2)
is greater than or equal to 20 percent.
Before calculating the supplementary heat requirements,
the temperature of the flue gas leaving the catalyst bed
(TTO) should be estimated to ensure that an adequate
overall reaction rate can be achieved to give the desired
destruction efficiency without damaging the catalyst. In
otherwords, check whetherTco falls in the interval 1,000°
-1,200°Fto ensure a high destruction efficiency without
catalyst damage. Use Equation 4.3-2 to calculate Tco.
This equation assumes a 50°F temperature increase for
every 1 Btu/scf of heat content:
(4.3-2)
where:
he = heat content of the emission stream, Btu/scf
In this expression, it is assumed that the heat content of
the emission stream and the comb ined gas stream is the
same. First, insert a value of 600°F for Tc. in equation
4.3-2. Then determine if Tco is in the range of 1,000° -
1,200°F. If this is true then the initial value of Tcj is
satisfactory. If T00 is less than 1,000°F, use the following
equation to determine an appropriate value for T,, (above
600°F) and use this new value of T^ in the calculations
below:
Td -1,000-50 h.
(4.3-3)
The value of T^ obtained from Equation 4.3-3 is then
used in Equation 4.3-4.
(Note: Emission streams with high heat contents will be
diluted based on the requirements discussed in Section
4.3.2. Therefore, valuesforT^, exceeding 1 ,200°F should
not occur.)
For catalytic incinerators, a 50 percent efficient heat
exchanger is assumed, while for thermal incineration a
70 percent efficient exchangeris assumed. A 70 percent
efficient heat exchanger forcatalytic oxidation can result
in excessive catalyst bed temperatures. Therefore, a 50
percent efficient heat exchanger is assumed for pur-
poses of this report, although 70 percent efficient heat
exchangers may be found on some streams.
To calculate supplementary heat requirements (based
on natural gas as the fuel), use the following simplified
equation for dilute emission streams that require no
additional combustion air:
Qf-
where:
Qf =
D =
D. m
Q =
T =
Qe
e [Cpair (1 .1 Td- Th8 - 0.1 Tf)] (4.3-4)
Tr
T
to
h. =
D,[hf-(1.1CPaJr(Tcl-Tr)]
fuel gas flow rate, scfm
density of emission stream, Ib/ft3 (typically,
0.0739 lb/fta)
density of fuel gas (0.0408 Ib/ft3 for methane
at 77°F)
emission stream flow rate, scfm
average specific heat of air over a given
temperature interval, Btu/lb-°F (See Table
C.8-1)
temperature of combined gas stream enter-
ing the catalyst bed, °F
reference temperature, 77°F
emission stream temperature after heat re-
covery, °F
lower heating value of natural gas, 21 ,600
Btu/lb
4-14
-------
Note that for the ease of no heat recovery, T^ = Te. The
factor 1 .1 attempts to account for an estimated heat loss
of 10 percent in the incinerator. Supplementary heat
requirements are based on maximum emission flow
rate, and hence will lead to a conservative design. In
contrast to thermal incineration, there is no minimum
supplementary heat requirement specified for catalytic
incineration since no fuel is needed for flame stabiliza-
tion. Depending on the HAP concentration, emission
stream temperature, and level of heat recovery, supple-
mentary heat requirements may be zero when heat
recovery is employed.
Calculate Tta using the following expression if the value
for TN is not specified.
i» " (HR/100) Tco + [1 - (HR/1 00)J
(4.3-5)
4.3.4.2 Flow Rate of Combined Gas Stream
Entering the Catalyst Bed
To calculate the quantity of catalyst required, the flow
rate of the combined gas stream (emission stream +
supplementary fuel combustion products) at the inlet to
the catalyst bed has to be determined. Use the following
equation:
(4.3-6)
where:
= flow rate of the combined gas stream, scfm
= flow rate of emission stream, scfm
= natural gas flow rate, scfm
= dilution air requirement, scfm
4.3.4.3 Flow Rate of Flue Gas Leaving the
Catalyst Bed
In order to determine costs for incinerators, the flow rate
of flue gas leaving the catalyst bed must be determined.
Assume that the flow rate of the combined gas stream
entering the catalyst bed is approximately equal to the
flow rate of the flue gas leaving the catalyst bed at
standard conditions. The volume change across the
catalyst bed due to the combustion of the HAP in the
mixed gas stream is small, especially when dilute emis-
sion streams are treated. Therefore,
fg ~~ ^com
where:
Qfg = flow rate of the flue gas leaving the catalyst
bed, scfm
When calculating costs, assume that catalytic incinera-
tors are designed for a minimum Q, of 2,000 scfm.1
Therefore, if Q, is less than 2,000 sclm, define Qte as
2,000 scfm.
In some instances, operating costs are based on the flue
gas flow rate at actual conditions. (The cost procedures
detailed later in this section use scfm.) However, if
necessary the following equation can be used to convert
from scfm to acfm:
. (4.3-7)
where:
Qfga is the flue gas flow rate at actual conditions (acfm)
4-15
-------
Using Equation 4;§-?;|
« • 54,900
Table 4.3-2.
4.3.5 Catalyst Bed Requirement
The total volume of catalyst required for a given destruc-
tion efficiency is determined from the design space
velocity as follows:
(4.3-8)
where:
Comparison of Calculated Values and Values Sup-
plied by the Permit Applicant tor Catalytic
Incineration*
Calculated
Value
(Example Case}*
Reported
Value
Continuous monitoring of
temperature rise and pressure
drop across catalyst bad yes
Supplementary fuel flow
rate, Q, 179 scfm
Dilution air flow rate, Qd 0
Combined gas steam flow
rate, Q,^ 20,200 sefm
Catalyst bed volume, V^^ 40 fl?
•Based on Emission Stream 2.
Vud» volume of catalyst bed required, ft3
4.3.6 Evaluation of Permit Application
Compare the results from the calculations and the
values supplied by the permit applicant using Table 4.3-
2. The calculated values in the table are based on the
example case.
If the calculated values agree with the reported values,
then the design and operation of the proposed catalytic
incinerator system may be considered appropriate based
on the assumptions used in this handbook.
4.3.7 Capital and Annual Costs of Catalytic
Incinerators
This section presents procedures for estimating the
capital and annual costs of af ixed bed catalytic incinera-
tor.
4.3.7.1 Catalytic Incinerator Capital Costs
The capital cost of a catalytic incinerator is estimated as
the sum of the equipment cost (EC) and the installation
cost. The equipment cost is primarily a function of the
total emission stream flow rate and the heat exchanger
efficiency as well as the cost of auxiliary equipment.
Table 4.3-3 provides equations to estimate the equip-
ment cost of fixed bed catalytic incinerators based on
Ox™ and HR. Refer to Section 4.12 to obtain the auxiliary
costs.
The equations given in Table 4.3-3 are to be used for
flow rates from 2,000 scfm to 50,000 scfm, and will yield
costs in April 1988 dollars. These costs include instru-
mentation. These equations should not be extrapolated
outside their range.
Afterobtaining equipment costs, the next step inthecost
algorithm is to obtain the purchased equipment cost,
PEC. The PEC is calculated as the sum of the equipment
cost EC (incinerator and auxiliary equipment) and the
cost of instrumentation, freight and taxes. Table 4.3-4
provides appropriate factors to estimate these costs.
After obtaining the purchased equipment cost, PEC.the
total capital cost (TCC) is estimated using the factors
presented in Table 4.3-4.
Table 4.3-3. Equipment Costs for Fixed Bed Catalytic
Incinerators*
Catalytic Incinerator Cost,
CC (April 1888 $)
Heat Exchanger Efficiency,
HR
CO - 3,623 QcanMI89
CC = 1,21SQeJ)6575
HR= 0%
HR = 35%
HR=50%
HR - 70%
'Reference s.
4-16
-------
4.3.7.2 Catalytic Incinerator Annual Costs
The total annual cost (TAG) of a catalytic incinerator
consists of direct and indirect annual costs. Table 4.3-6
contains appropriate factors used to estimate total an-
nual costs, while the discussion below details the infor-
mation necessary to correctly use these factors.
Direct Annual Cost These costs include fuel, electricity,
catalyst replacement operating and supervisory labor,
and maintenance labor and materials.
Fuel usage is calculated in Section 4.3.4.2. Once this
value is calculated, multiply it by 60 to obtain scfh and
multiply this by the annual operating hours to obtain the
annual fuel usage. Then simply multiply the annual fuel
usage by the cost of fuel to obtain this annual cost.
Electricity costs are primarily associated with the fan
needed to move the gas through the incinerator. Use
Equation 4.3-9 to estimate the power requirements for a
fan assuming a combined motor-fan efficiency of 65
percent and a fluid specific gravity of 1.0.
= 1.81x10-MQ(aa){PHHRS)
(4.3-9)
Table 4.3-4. Capital Cost Factors for Catalytic Incinerators*
Cost Item
Factor
Direct Costs
Purchased equipment costs
Incinerator (CC) + auxiliary equipment, EC
Instrumentation1'
Sales taxes
Freight
Purchased Equipment Cost, PEC
Direct installation costs
Foundations & supports
Handling & erection
Electrical
Piping
Insulation for ductwork0
Painting
Direct Installation Cost, DC
Site preparation •:
Buildings
Total Direct Cost, DC
Indirect Costs (installation)
Engineering
Construction and field expenses
Contractor fees
Start-up
Performance test
Contingencies
Total Indirect Cost, 1C
Total Capital Cost (TCC) = DC rHC :
As estimated, EC
0.10 EC
0,03 EC
0.05 EC
PEC = 1.18 EC
0.08 PEC
0.14 PEC
0,04 PEC
0.02 PEC
0.01 PEC
0.01 PEC
0.30 PEC
As required, SP
As required. Bldg.
1.30 PEC + SP + Bldg.
0.10 PEC
0.05 PEC
0.10 PEC
0.02 PEC
0.01 PEC
o!31 PEC
1.61 PEC +SP + Bldg.
•References. .
Instrumentation and controls often furnished with the incinerator, and thus often included in the EC.
"if ductwork dimensions have been established, cost may be estimated based on $10 to $12/tt2 of surface for field application. Fan housings and
stacks may also be insulated. :
4-17
-------
Tablo 4,3-5. Example Case Capital Costs
Cost Item
Factor
Cost($)
Direct Costs
Purchased Equipment Costs, PEC
Incinerator (EC) + auxiliary equipment
Instrumentation
Sales Tax
Freight
Purchased Equipment Cost, PEC
Direct Installation costs
Foundation and supports
Handling and erection
Electrical
Piping
Insulation for ductwork
Painting
Direct Installation Cost
Slta preparation
Bunding
Totai Direct Cost, DC
Indirect Costs
Engineering
Construction and field expense
Contractor fees
Start-up
Performance test
Contingencies
Total Indirect Cost, 1C
Total Capital Cost
Total Capital Cost - $547,000 + SP + BIdg.
DC -i- 1C
$340,000 + $102,000 + $105,000 + SP
BIdg.
Included
0.03
0.05
0,08 PEC
0.14 PEC
0.04 PEC
0,02 PEC
O.Ot PEC
0.01 PEC
0.30 PEC
0.10 PEC
0.05 PEC
0.10 PEC
0.02 PEC
0.01 PEC
0.03 PEC
0.31 PEC
$315,000
0
9,500
15.800
$340,000
$ 27,200
47,700
13,600
6,300
3,400
3.400
$102,000
As required, SP
As required, BIdg.
$340,000 + $102,000
+ SP + BIdg.
$34,000
17,000
34,000
6,800
3,400
10.200
$105,000
where:
Fp * power needed for fan, kWh/yr
Q,0, = total emission stream flowrate, acfm
P 3 system pressure drop, in. H.O (from
Table 4.3-7)
HRS =» operating hours per year, hr/yr
cost used in estimating the capital recovery cost, can be
obtained by multiplying the catalyst requirement by the
catalyst cost.
Operating labor requirements are estimated as 0.5
hours per 8-hour shift. The operator labor wage rate is
provided in Table 4.3-6. Supervisory costs are esti-
mated as 15 percent of operator labor costs.
In general, catalyst replacement costs are highly vari-
able and depend on the nature of the catalyst, the
amount of poisons and particulates in the emission
stream, the temperature history of the catalyst, and the
design of the unit. Given that these costs are so variable
ft is not possible to accurately predict the costs for a
given application. However, for purposes of this report,
ft is assumed the catalyst has a life of two years. To
estimate this cost, multiply the catalyst volume from
section 4.3.5 by the appropriate capital recovery factor
assuming a two year life and 10 percent interest rate (i.e,
CRF » 0.5762). The catalyst replacement cost can be
estimated asSSSO/ft3 forbase metal oxideeatalysts, and
$3,000/ft3 for noble metal catalysts.5 The initial catalyst
Maintenance labor requirements are estimated as 0.5
hours per 8-hour shift with a slightly higher labor rate
(see Table 4,3-6) to reflect increased skill levels. Main-
tenance materials are estimated as 100 percent of
maintenance labor.
Indirect annual costs. These costs include the capital
recovery cost, overhead, property taxes, insurance.and
administrative charges. The capital recovery cost is
based on an estimated 10-year equipment life and
subtracts out the initial catalyst cost, while overhead,
property taxes, insurance, and administrative costs are
percentages of the total capital cost. Table 4.3-6 con-
tains the appropriate factors for these costs.
4-18
-------
Table 4.3-6. Annual Cost Factors for Catalytic Incinerators*
Cost Item
Factor
Direct Annual Cost (DAG)11
Utilities
Fuel (natural gasf
Electricity
Catalyst replacement
Operating Labor
Operator
Supervisor
Maintenance
Labor
Material
Indirect Annual Cost (IAC)
Overhead
Administrative
Property taxes
Insurance
Capital recovery*
$3.30/1,000 ft?
$0.059/kwh
$650/fl? base metal oxide
$3,000/ft? precious metal
$12.96/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
0.60 (Operating labor
and maintenance costs)
2%ofTCC
1%ofTCC
1%ofTCC
0.1628 [TCC - 1.08 (Cat. cost)]
'Reference 5.
"1988 dollars.
The fuel cost may vary. When possible, obtain a value more
appropriate for the situation.
•The capital recovery factor is calculated as: l(1+i)"/(1-t-i)" -1
where: i = interest rate,
10 percent
n - equipment life,
10 yrs
Table 4.3-7. Typical Pressure Drops for Catalytic Incinerators*
Equipment Type
Catalytic Incinerator
(Fixed-Bed)
Heat Exchanger
Heat Exchanger
Heat Exchanger
Heat Recovery
HR(%)
0
35
50
70
Pressure Drop
P(in. HS0)
6
4
8
15
"The pressure drop is calculated as the sum of the incinerator and heat
exchanger pressure drops.
4-19
-------
4.3.8 References
1. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. EPA 625/6-86-014 (NTIS
PB91-228809). Cincinnati, OH. September 1986.
2. U.S. EPA. Polymer Manufacturing Industry - Back-
ground Information for Proposed Standards. EPA
450/3-83-0193 (NTIS PB88-114996), September
1985.
3, U.S. EPA. Afterburner Systems Study. EPA-R2-
72-062 (NTIS PB 212560). August 1972.
4. U.S. EPA. Parametric Evaluation of VOC/HAP
Destruction Via Catalytic Incineration. EPA-600/2-
85-041 (NTIS PB85-191187). April 1985.
5. U.S. EPA. OAQPS Control Cost Manual. Fourth
Edition, EPA 450/3-90-006 (NTIS PB90-169954),
January 1990.
6. U.S. EPA. VOC Control Effectiveness. EPA Con-
tract No. 68-02-4285, WA1/022. For Carlos Nunez,
U.S. EPA, AEERL February 1989.
7. U.S. EPA. Evaluation of Continuous Compliance
Monitoring Requirements for VOC Add-on Control
Equipment. EPA Contract No. 68-02-4464, WA 60.
For Vishnu Katari, U.S. EPA, SSCD. September
1989.
8. U.S. EPA. Soil Vapor Extraction VOC Control
Technology Assessment. EPA-450/4-89-017 (NTIS
PB90-216995). September 1989.
9. Telecon. Sink, Michael, PES, with Yarrington, Rob-
ert. Englehard Corp., Edison, NJ. Space velocities
for catalysts, and incinerator efficiency. April 1990.
4.4 Flares
Open flames used for disposing of waste gases during
normal operations and emergencies are called flares.
They are typically applied when the heating value of the
waste gases cannot be recovered economically be-
cause of intermittent or uncertain flow, or when the value
of the recovered product is low. In some cases, flares are
operated in conjunction with baseload gas recovery
systems (e.g., condensers). Flares handle process up-
set and emergency gas releases that the baseload
system is not designed to recover.
Several types of flares exist, the most common of which
are steam-assisted, air-assisted, and pressure head
flares. Typical flare operations can be classified as
"smokeless," "nonsmokeless," and "fired" or "endother-
mic." For smokeless operation, flares use outside mo-
mentum sources (usually steam or air) to provide effi-
cient gas/air mixing and turbulence for complete com-
bustion. Smokeless flaring is required for destruction of
organics heavier than methane. Nonsmokeless opera-
tion is used for organic or other vapor streams which
burn readily and do not produce smoke. Fired, or endo-
thermie, flaring requires additional energy in order to
ensure complete oxidation of the waste streams such as
for sulfur tail gas and ammonia waste streams.
In general, flare performance depends on such factors
as flare gas exit velocity, emission stream heating value,
residence time in the combustion zone, waste gas/
oxygen mixing, and flame temperature. Since steam-
assisted smokeless flares are the most frequently used,
they will be the focus of this discussion. Atypical steam-
assisted flare system is shown in Figure 4.4-1. First,
process off-gases enter the flare through the collection
header. When water or organic droplets are present,
passing the off-gases through a knockout drum may be
necessary since these droplets can create problems.
Water droplets can extinguish the flame and organic
droplets can result in burning particles.
Once the off-gases enterthe flare stack, flame flashback
can occur if the emission stream flow rate is too low.
Flashback may be prevented, however, by passing the
gas through a gas barrier, a water seal, or a stack seal.
Purge gas is anotheroption. At the flare tip, the emission
stream is ignited by pilot burners. If conditions in the
flame zone are optimum (oxygen availability, adequate
residence time, etc.), the VOC in the emission stream
may be completely burned (~100 percent efficiency). In
some cases, it may be necessary to add supplementary
fuel (natural gas) to the emission stream to achieve
destruction efficiencies of 98 percent and greater if the
net heating value of the emission stream is less than 300
Btu/scf.1-2
Typically, existing flare systems will be used to control
HAP emission streams. Therefore, the following sec-
tions describe how to evaluate whether an existing flare
system is likely to achieve a 98 percent destruction
efficiency under expected flow conditions (e.g., continu-
ous, start-up, shut-down, etc.). The discussion will be
based on the recent regulatory requirements of 98
percent destruction efficiency forf lares.1 The calculation
procedure will be illustrated for Emission Stream 3
described in Chapter 3 using a steam-assisted flare
system. Note that flares often serve more than one
process unit and the total flow rate to the flare needs to
be determined before the following calculation proce-
dure can be applied. A flare sizing algorithm (the Pega-
sus algorithm) has been developed using a computerto
obtain quick algorithm convergence. For more informa-
tion on this system, consult Reference 8.
4.4.1 Data Required
The data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form, flare
dimensions, and the required HAP control as deter-
mined by the applicable regulations.
4-20
-------
Figure 4.4-1. Typical steam assisted flare.
Gas Collection Header
and Transfer Line
Steam
Nozzles
Emission
Stream
Knock-out Drum
Pilot Burners
_ — Steam Line
I 1*1 Ignition Device
I I • Air Une
-*—^—— Gas Line
Drain
:
In the case of a permit review, the data outlined below
should be supplied by the applicant. The calculations in
this section will then be used to check the applicant's
values. Worksheets are provided in Appendix C.5.
Flare system variables at standard conditions (77°F,
1 atm): ,
Flare tip diameter, D,., in
Expected emission stream flow rate, Qa, scfm
Emission stream heat content, he, Btu/scf
Temperature of emission stream, T8, °F
Mean molecular weight of emission stream,
MW, Ib/lb-mole
Steam flow rate, Qs, Ib/min
Flare gas exit velocity, IL, ft/sec
Supplementary fuel flow rate, Qf, scfm
Supplementary fuel heat content, hf, Btu/scf
Temperature of flare gas, Tflg,°F
Flare gas flow rate, Q(la, scfm
Flare gas heat content, h((gl Btu/scf
4.4.2 Determination of Flare Operating Variables
Based on studies conducted by EPA, relief gases having
heating values less than 300 Btu/scf are not assured of
achieving 98 percent destruction efficiency when they
are flared in steam- or air-assisted flares.1-2 Therefore,
the first step in the evaluation procedure is to check the
heat content of the emission stream and determine if
additional fuel is needed.
In a permit review case, if the heat content of the
emission stream is less than 300 Btu/scf and no supple-
mentary fuel has been added, then the application is
considered unacceptable. The reviewer may then wish
4-21
-------
to follow the calculations described below. If the re-
ported value for the emission stream heat content is
above 300 Btu/scf, however, then the reviewer should
skip to Section 4.4.2.3.
4.4.2.1 Supplementary Fuel Requirements
If the emission stream heat content is less than the 300
Btu/scf required to achieve a destruction level of 98
percent, it is assumed that natural gas will be added to
the emission stream to bring its heat content to 300 Btu/
scf. Calculate the required natural gas requirements
using the following equation:
Q,=[(300-h8)QJ/582
(4.4-1)
where:
emission stream flow rate, scfm
natural gas flow rate, scfm
emission stream heat content, Btu/scf
882-300; 882=!ower heating value of
natural gas, Btu/scf
If the emission steam heat content is greater than or
equal to 300 Btu/scf, then Q, = 0.
Using Equation 4.4-1;
Since h. Is less than 300 B^^fjil
— '• "'••-- --:
I
180 Btu/scf -;;-
30,000 scfm" •v/:¥a;Ja|:»::;S:l
J(300 - 180)(30,OQ|5)|S||gl
6,r
4.4.2.2 Flare Gas Flow Rate and Heat Content
The flare gas f tow rate is determined from the flow rates
of the emission stream and natural gas using the follow-
ing equation:
(4.4-2)
where:
Qlls«flare gas flow rate, scfm
Note that if Q, = 0, then Q(lg = QB
The heat content of the flare gas (h)lg) is dependent on
whether supplementary fuel is added to the emission
stream. When he is greater than or equal to 300 Btu/scf,
then h))B « ht. If hs is less than 300 Btu/scf, since
supplementary fuel is added to increase hB to 300 Btu/
scf, h(ln - 300 Btu/scf.
4.4.2.3 Flare Gas Exit Velocity and Destruction
Efficiency
Table 4.4-1 presents maximum flare gas exit velocities
(U^) necessary to achieve at least 98 percent destruc-
tion efficiency in a steam-assisted flare system. These
values are based on studies conducted by EPA.1-2 Flare
gas exit velocities are expressed as a function of flare
gas heat content. The maximum allowable exit velocity
can be determined using the equation presented in
Table 4.4-1.
The information available on flare destruction efficiency
as a function of exit velocity does not allow for a precise
determination of this value. All that; can be ascertained
is whether the destruction efficiency is greater than or
less than 98 percent, depending the exit velocity.
If a flare is controlling an intermittent process stream (or
streams), a continuous monitoring system should be
employed to ensure that .the pilot light has a flame. If a
flare is controlling a continuous process stream, continu-
ous monitoring of either the flare flame or the pilot light
is acceptable.
From the emission stream data (expected flow rate,
temperature) and information on flare diameter, calcu-
late the flare gas exit velocity (UJlg); compare this value
Table 4,4-1. Flare Gas Exit Velocities for 98 Percent Destruc-
tion Efficiency1
Flare Gas Heat Constant*
hBB (Btu/scf)
Maximum Exit Velocity
U^ (ft/sec)
h(lg<300
300 £hBg< 1,000
V<1,000
_b
3.28 [10
400
i on studies conducted by EPA, waste gases having heating
values less than 300 Btu/scf are not assured of achieving 98%
destruction efficiency when they are flared in steam-assisted flares.3
4-22
-------
with Ummx. Use Equation 4.4-3 to calculate Uflg. This
equation is taken from Reference 6.
Uflfl= (5.766X10
,-s
)(Q admin+ 460)
(DtiP2 )
(4.4-3)
where:
U,ig = exit velocity of flare gas, ft/sec
Qflg m flare gas flow rate, scfm
Dt^ = flare tip diameter, in
If U^ is less than U , then the 98 percent destruction
levefcan be achieved. However, if U%exceeds U , this
destruction efficiency level may not oe achievea This
indicates that the existing flare diameter is too small for
the emission stream under consideration, and may lead
to reduced efficiency. Note that at very low flare gas exit
velocities, flame instability may occur, affecting destruc-
tion efficiency. The minimum flare gas exit velocity for a
stable flame is assumed as 0.03 ft/sec in this manual*.
Thus, if U))gis below 0.03 ft/sec, the desired destruction
efficiency may not be achieved. Insummary, Uflg should
fall in the range of 0.03 ft/sec and Umax for a 98 percent
destruction efficiency level.
In a permit review case, if U^ exceeds Umax, then the
application is not acceptable. If Uflg is below U,^ and
exceeds 0.03 ft/sec, then the proposed design is consid-
ered acceptable and the reviewer may proceed with the
calculations.
4.4.2.4 Steam Requirements
Steam requirements for steam-assisted flare operation
depend on the composition of the flare gas and the flare-
tip design. Typical values range from 0.15 to 0.50 Ib
steam/lb flare gas. In this handbook, the amount of
steam required for 98 percent destruction efficiency is
assumed as 0.4 Ib steam/lb flare gas.5 Use the following
equation to determine steam requirements;
Q = steam requirement, Ib/min
flfl ». [(Qf)(16.7)*(Qe){MWe)l/Q,lg
Qs « 1 .03 x 1 0'3 x
where:
x MW
(lg
(4.4-4)
4.4.3 Evaluation of Permit Application
Compare the results from the calculated and reported
values using Table 4.4-2. If the calculated values of Q(,
U(lg, Qflg, and Qs are different from the reported values for
these variables, the differences may be due to the
assumptions (e.g., steam to flare gas ratios, etc.) in-
volved in the calculations. In such a case, the reviewer
may wish to discuss the details of the proposed system
with the permit applicant.
If the calculated values agree with the reported values,
then the operation of the proposed flare system may be
considered appropriate based on the assumptions made
in this handbook.
4.4.4 Capital and Annual Costs of Flares
In many cases, existing flares are employed by a facility
and hence, obtaining flare costs for a new system is not
necessary. For cases where cost information is neces-
sary, Section 4.4.4 can be used to obtain capital and
annual flare costs.
4.4.4.1 Capital Costs of Flares
The capital cost for a flare is composed of purchased
equipment costs and direct and indirect installation
costs. The purchased equipment cost is the sum of the
equipment costs (flare + auxiliary equipment) and the
cost of instrumentation, freight, and taxes. Factors for
these costs are presented in Table 4.4-3. The cost of
auxiliary equipment for a flare can be obtained from
Section 4.12 and includes the cost of ductwork, damp-
ers, and fans.
The equipment cost of a flare is a function of the flare tip
diameter (DtJ, height (H), and the cost of auxiliary
equipment. The procedure used to obtain the flare
height, H, is taken from Reference 6, while the flare cost
equations were obtained from the Emissions Standards
Division of the Office of Air Quality Planning and Stan-
dards, US EPA, RTP, NO. The flare cost is dependent
upon the type of flare stack used. Typical configurations
include the self supporting configuration used between
30 and 100 feet; guy towers, used for upto 300 feet; and
derrick towers, used for heights above 200 feet.
4-23
-------
Table 4.4-2. * Comparison of Calculated Values and Values
supplied by the Permit Applicant for Flares Recall the flare tip diameter, D wasprovided inSection
4.4.1. This calculated diameter should be rounded up to
calculated the next largest commercially available size. The mini-
value Reported mum diameter is 1 inch with larger diameters available
(Example case)- Value jn 2_jncn increments between 2 and 24 inches, and 6-
inch increments between 24 and 60 inches.
Appropriate continuous
monitoring system Yes ... The flame angle, 6, is calculated below:
Emission stream heating
value, h, 180Btu/scf ... 0 m JAN'1 (1.47 V,/(550 (AF'/55)1ffl)] (4.4-5)
Supplementary fuel flow rate, Q, 6,200 scfm
Flare gas exit velocity, U)lg 40 ft/sec ... where:
Flare gas flow rate, Q 36.200 scfm ... 9 = Flame angle, degrees
Steam ftow rate, Q. 1.140 Ib/min ... V« = wind veloc^ (assumed to equal 60 mph)
! AP = pressure drop, in. H2O
•Based on Emission Stream 3. = 55 (U.J550)2 where Ufln is obtained from
Section 4.4.2.3
Table 4.4-3. Capital Cost Factors for Flares*
i Cost Item Factor
DlrgctCosts
Purchased equipment costs
Flare (FC) + auxiliary equipment, EC As estimated, EC
Instrumentation 0.10 EC
Sales taxes 0.03 EC
Freight 0.05 EC
Purchased Equipment Cost, PEC PEC -1.18 EC
Direct Installation costs
Foundations & supports 0.12 PEC
Handling & erection 0.40 PEC
Electrical 0.01 PEC
Piping 0.01 PEC
Insulation for ductwork 0.01 PEC
Painting 0.01 PEC
Direct Installation Cost 0.56 PEC
Site preparation As required, SP
Buildings As required. Bldg.
Total Direct Cost (DC) 1.66 PEC + SP + BWg.
Indirect Costs (Installation)
Engineering 0.10 PEC
Construction and field expenses 0.1 OPEC
Contractor fees 0.10 PEC
Start-up 0.01 PEC
Performance test 0.01 PEC
Contingencies 0.03 PEC
Total Indirect Cost (IC) 0.3S PEC
Total Capital Costs = DC + IC 1.91 PEC + SP + Bldg.
•Obtained from Emissions Standards Division, OAQPS, EPA, RTP, NC. ' "
4-24
-------
Table 4.4*4. Example Case Capital Costs
Cost Item
Factor
Cost($)
Direct Costs
Purchased equipment costs
Flare (EC) + auxiliary equipment, EC
Instrumentation
Sales taxes
Freight
Purchased Equipment Cost, PEC
Direct installation costs
Foundations & supports
Handling & erection
Elecfrical
Piping
Painting
Insulation
Direct Installation Cost
Site preparation
Buildings
Total Direct Cost, DC
Indirect Costs (Installation)
Engineering
Construction and field expenses
Contractor fees
Start-up
Performance test
Contingencies
Total Indirect Cost, 1C ,
Total Capital Cost = DC + 1C
As required
0.10 EC
0.03 EC
MSEC
PEC=1.18EC
0.12 PEC
0.40 PEC
0.01 PEC
0.01 PEC
0.01 PEC
PEC
1.56 PEC + SP
0.10 PEC
0.10 PEC
0.10 PEC
0,01 PEC
0.01 PEC
0.03 PEC
0.35 PEC
1.91 PEC + SP + BWg
$393,000
39,600
11,900
19.800
$467,000
$ 56,000
187,000
4,670
4,670
4.670
4,670
$262,000
As required, SP
As required, Bldg.
$467,000 + $262,000
$46,700
46,700
46,700
4,670
4,670
14,000
$892,000 + SP + Bldg.
This reduces to:
6 = TAN'1 (88.2/U()g) (4.4-6)
The flare height is calculated using Equation 4.4-7:
H » [(0.02185) (Q^xh r
-(6.05x10^(0;) (10008(6)]
(4.4-7)
Flare equipment costs in March 1990 dollars are pre-
sented in Equations 4.4-8 through 4.4-10 as a function
of flare height and diameter. Equation 4.4-8 is used for
self supporting flares, Equation 4.4-9 is used for guy
support flares, and Equation 4.4-10 is usecl for derrick
support flares.
FC - [78 + 9.14 (D%) + 0.749 (H)]2] (4.4-8)
where: FC = flare cost for self support
FC . [103 + 8.68 (D,.,) + 0.470 (H)]2 (4.4-9)
where: FC = flare cost for guy support
FC = [76.4 + 2.72 (D^) + 1.64 (H)f (4.4-10)
where: FC = flare cost for derrick support
For all three cases, the flare cost includes the flare stack
and support, burner tip, pilots, utility piping, 100 feet of
vent stream piping, utility metering and control, water
and gas seals, and platforms and ladders. The costs are
based on carbon steel construction except forthe upper
four feet and the burner tip which is constructed of 316L
stainless steel.
Once FC has been obtained, Table 4.4-3 is used to
obtain the flare capital costs. The flare equipment cost
(EC) is obtained by adding FC to any auxiliary equip-
ment, while the purchased equipment cost (PEC) is
obtained using the factors given in Table 4.4-3.
The total capital cost (TCC) of a flare is the sum of the
, purchased equipment cost and the direct and indirect
installation cost factors. These factors are given in Table
4.4-3 as a percentage of the purchased equipment cost.
4-25
-------
Example Case
From Section.44.2.3, U,w=40ft/see. Using Equation
4.4-6 to obtain the flame angle, 0* ,we have:
9 » TAN'1188,2/40)« 65,6°
Next, use Equation 4,4-7to obtafmtte flare height, H;
H «. {(0.02185X36,200 x3QQ)te-6^5xf04
(60)(40){Cos{65.6°})|
H « 66ft
Since H is between 45 and 200 feet, Equation 4,4-8
fs used for the flare cost FC, .^ , "
FG -- [78 + 9.14 (54) 4- 0.749 (66)]E
FC* $386,000
Assume auxiliary equipment costs (i.e., ductwork,
dampers, and fans) from Section 4.12 are $10,000,
The equipment cost EC Is then $386,000 +$i 0,000
« $396,000,
Next, use Table 4,41-3 to obtain the purchased equip-
ment cost, PEC, as shown below.
Instrumentation * 0.10 (EC)« $39,600
Sales taxes * 0,03 (EC)« $11 $00
Freight * 0.05 (EC) ** $19.800
$71,300
The purchased equipment cost, P1=C» is therefore
equal to $467,000. Table 4.4*3 is then used to obtain
the total capital cost, TCC. These costs are given in
Table 4.4-4.
Table 4.4-5. Annual Cost Factors for Flares*
Cost Item Factor
4.4.4.2 Flare Annual Costs
The total annual cost (TAG) of a flare is the sum of the
direct and indirect annual costs, which are discussed in
more detail below. Table 4.4-4 contains the appropriate
factors necessary to estimate the TAG.
Direct Annual Cost. The direct annual cost includes the
cost of fuel, electricity, pilot gas, steam, operating and
supervisory labor, and maintenance labor and materi-
als.
Fuel usage (in scfm) is calculated in Section 4.4.2.1.
Once this value (Q() is calculated, multiply it by 60 to
obtain the fuel usage in scfh, and multiply this by the
annual operating hours to obtain the annual fuel usage.
Then simply multiply the annual fuel usage by the cost
of fuel provided in Table 4.4-5 to obtain annual fuel
costs.
The electricity cost is primarily associated with a fan
needed to move the gas through the flare. Equation 4.4-
Direct Annual Costs (DAG)"
Utilities
Fuel (natural gas)0
Electricity
Steam
Operating Labor
Operator
Supervisor
Maintenance
Labor
Material
Indirect Annual Cost(IAC)
Overhead
Administrative
Property taxes
Insurance
Capital recovery1
$3.30/103 ft»
$0.059/kwh
$6.00/10* Ib steam
$12.96/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
0.60 (Operating labor
and maintenance costs)
2% of TCC
1% of TCC
1% of TCC
0.1315 (TCC)
"Reference 6, 7.
"1988 $.
cThis cost may vary. When possible, obtain a value more appropriate
for the situation.
The capital recovery factor is calculated as: i(1+l)"/(1+i)" -1
where: i •« Interest rate,
10 percent
n « equipment life,
15yrs
10 can be used to estimate the power requirements for
a fan. This equation assumes a fan-motor efficiency of
65 percent and a fluid specific gravity of 1.0.
p
where:
&.
Fp = 1.81x10-4 (Q^J (P) (HRS) (4.4-11)
HRS
power requirement for fan, kWh/hr
actual flare gas flow rate, scfm
system pressure drop, in. H2O (typically,
16 inches of H2O)
annual operating hours, hr/yr
The steam requirement for a flare is calculated in Sec-
tion 4.4.2.4. This value (Q8) is then multiplied by 60 to
obtain the steam requirement on an hourly basis. This is
multiplied by the annual operating hours and by the cost
of steam provided in Table 4.4-5, to obtain annual steam
costs.
Operating labor requirements are estimated as 0.5
hours per 8-hour shift. The operator labor wage rate is
provided in Table 4.4-5. Supervisory costs are esti-
mated as 15 percent of operator labor costs.
Maintenance labor requirements are estimated as 0.5
hours per 8-hour shift with a slightly higher labor rate
(see Table 4.4-5) to reflect increased skill levels. Main-
tenance materials are estimated as 100 percent of
maintenance labor.
4-26
-------
Indirect Annual Costs. These costs include the capital
recovery cost, overhead, property taxes, insurance, and
administrative charges. The capital recovery cost is
based on an estimated 15-year equipment life, while
overhead, property taxes, insurance, and administrative
costs are percentages of the total capital cost, Table 4.4-
5 contains the appropriate factors for this cost.
• = -••-v**v -•••"• •:• virs'."."• •*--:-^>>:>? •;•;•:":•:•:-:•:">:£•''•'••:•;•<:•:•:•:•>:>>:• ••ivx-:•T•;'':'X••^•;•4••-:-"•;-^>x-x••^•-"•"-"-'•'•'•"-'"'-'•'-''-•'•'•'•••
rSJSWa&xSSiB*:!^
4.4.5 References
1. Federal Register. Vol. 50. April 16,1985. pp. 14941 -
14945.
2. U.S. EPA. Evaluation of the Efficiency of Industrial
Flares:TestResufts.EPA600/2-84-095(NTISPB84-
199371). May 1984.
3. U.S. EPA. Parametric Evaluation of VOC/HAP De-
struction Via Catalytic Incineration. EPA-600/2-85-
041 (NTIS PB85-191187). April 1985.
4. U.S. EPA. Organic Chemical Manufacturing. Vol. 4:
Combustion Control Devices. EPA-450/3-80-026
(NTIS PB81-220535), December 1980.
5. U.S. EPA. Reactor Processes in Synthetic Organic
Chemical Manufacturing Industry - Background In-
formation for Proposed Standards. Draft EIS. Re-
search Triangle Park, NC. October 1984.
6. U.S. EPA. Polymer Manufacturing Industry - Back-
ground Information for Proposed Standards. EPA-
450/3-83-019a (NTIS PB88-114996). September
1985.
7. U.S. EPA. OAQPS Control Cost Manual. Fourth
Edition, EPA-450/3-90-006 (NTIS PB90-169954).
January 1990.
8. G.S. Mason and R. Kamar. Algorithm Sizes Flare
Piping. Chemical Engineering, Vol. 95, No. 9. June
20,1988
4.5 Boiler/Process Heaters
Boilers or process heaters maybe used as a HAP vapor
control technique for selected sites. However, the appli-
cation of the devices is very site specific. The level of
detail required to evaluate a boiler/process heater as a
HAP vapor control technique is beyond the scope of this
manual and therefore is not presented.
4-27
-------
4.6 Carbon Adsorption
Adsorption is a surface phenomenon where volatile
organic compounds are selectively adsorbed on the
surface of such materials as activated carbon, silica gel
or alumina. Activated carbon is the most widely used
adsorbent and the focus of the discussion below. Ad-
sorption systems using silica gel or alumina are less
likely to be encountered in air pollution control and are
not discussed in this manual.
Adsorbed VOCs are removed from the carbon bed by
heating to a sufficiently high temperature (usually via
steam) or by reducing the pressure to a sufficiently low
value (vacuum desorption). During desorption, about 3
to 5 percent of organics desorbed on virgin activated
carbon is adsorbed so strongly that it cannot be des-
orbed during regeneration.
The equilibrium adsorption capacity of carbon is often
represented by adsorption isotherms that relate the
amount of VOC adsorbed (adsorbate)tothe equilibrium
pressure (or concentration) at constant temperature.
Typically, the absorption capacity of activated carbon
increases as the molecular weight of the adsorbate
increases. Also, unsaturated compounds and cyclic
compounds are generally more completely adsorbed
than either saturated compounds or linear compounds.
For virtually any adsorbate, the adsorption capacity is
enhanced by lower operating temperatures and higher
VOC concentrations. VOCs having lower vapor pres-
sures are more easily adsorbed than those with higher
vapor pressures. For most volatile organic compounds,
the vapor pressure is inversely proportional to the mo-
lecular weight of the compounds. Thus, heavier com-
pounds tend to be more easily adsorbed than lighter
compounds for a given adsorption system. Very heavy
compounds however, are difficult to desorb, and hence
carbon adsorption is not recommended for compounds
with molecular weights above 130 Ib/lb-mole.
A carbon adsorber system may have difficulties when
controlling an emission stream containing ketones (e.g.
acetone, methyl ethyl ketone). Ketones exothermically
polymerize on the carbon bed, clogging the pores on the
surface of the carbon which reduces the effective amount
of carbon contained in the vessel. This in turn, de-
creases the system efficiency. If a carbon adsorber
system is used to control ketones, the reader should be
aware of this potential problem.
4,6.1 Data Required
The data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form and the
required HAP control as determined by the applicable
regulations.
•SSaSSfiffti!»m;; CJriiiiiSfii*SBSs0\':SS«titiiii »S: sia^i^'K^nHiSSciSiFinSsS-SW
1
If dilution air is added to the emission stream upon exit
from the process (e.g. because of high HAP concentra-
tions), the data that will be used in the calculations are
the resulting characteristics after dilution.
in a permit review case for a carbon adsorber, the
following data should be supplied by the applicant. The
calculations in this section will then be used to check the
applicant's values.
Fixed bed carbon adsorber system variables at standard
conditions (77°F, I atm):
Reported removal efficiency, RE report9d %
HAP concentration, HAPB, ppmv
HAP inlet loading rate, MHAE, Ib/hr
Emission stream flow rate,Q8, ft3/min
Carbon bed working capacity, WG Ibs HAP/lbs
carbon
Number of beds, N
Amount of carbon required, C , Ib
Cycle time for adsorption, 0^, nr
Cycle time for regeneration 1^, hr
Emission stream velocity thru carbon bed, U6, ft/min
Vessel diameter, Dv, ft
Vessel length, Lv, ft
Steam used for regeneration, Qs, Ib/min
4.6.2 Adsorption Theory
At equilibrium, the quantity of HAP in a gas stream that
is adsorbed on activated carbon is a function of the
adsorption temperature and pressure, the specific com-
pound being adsorbed, and the carbon characteristics
(e.g., pore size and structure). For a given constant
temperature, a relationship exists between the mass of
adsorbate (i.e. HAP) per unit weight of adsorbent (i.e.,
carbon) to the partial pressure of HAP in the gas stream
as discussed above. This is called the equilibrium
adsorptivity. Adsorption isotherms are typically fitted to
a power curve as shown below;
>»rtial
where:
VV =
1 partial '
k,m >
equilibrium adsorptivity
(Ib adsorbate/lb adsorbent)
partial pressure of HAP in
emission stream
empirical parameters
The partial pressure is calculated as:
= (HAPJ(14.696x10-6)psia
4-28
-------
This equation type {i.e., the "Freundlich" equation) is
only valid for a specified absorbate partial pressure
range, and is a curve fit.1 For data outside the range of
the Freundlich equation the reader should refer to refer-
ence 1. The equilibrium adsorptivity, We, is the maxi-
mum amount of adsorbatethe carbon can hold at a given
temperature and partial pressure. In practice, theearbon
bed is never allowed to reach equilibrium as this would
result in excessive emissions and bed breakthrough. At
the point where the bed is taken off-line, the bed HAP
concentration may be only 50 percent of the equilibrium
concentration. Hence, in practice, the actual bed capac-
ity is less than the equilibrium capacity. This actual
capacity is called the effective, or working, capacity. The
working capacity, W0, is usually 50 percent or less than
the equilibrium capacity. Table 4.6-1 provides adsorp-
tion isotherm parameters for selected organic compo-
nents. If no other information is known, a default value of
50 percent of W can be used to obtain W0. If no
information on W or W0 can be found, use a default
value of 0.100 for w^
If the emission stream contains multiple HAPs, the
working capacity for the control system may be based on
the HAP with the lowest working capacity in the emission
stream. This conservative assumption will probably yield
a carbon requirement somewhat higherthan that calcu-
lated by a vendor. Nonetheless, the value obtained from
the calculations below can serve as a general guide for
the carbon requirement.
Table 4.6-1. Parameters for Selected Adsorption Isotherms'*
s %BftsiisW:*i;w&^iK^«^^^
Adsorption
Temp.
Adsorbate (°F)
(1) Benzene
(2) Chlorobenzene
(3) Cydohexane
(4) Dichloroethane
(5) Phenol
(6) Trichtoroethane
(7) Vinyl Chloride
(8) m-Xylene
(9) Acrytonltrile
(10) Acetone
(11) Toluene
77
77
too
77
104
77
100
. 77
77
100
100
77
Isotherm
Parameters
k m
0.597
1.05
0.508
0.976
0.855
1.06
0.20
0.708
0.527
0.935
0.412
0.551
0.176
0.188
0.210
0.281
0.153
0.161
0.477
0.113
0.0703
0.424
0.389
0.110
Range of
Isotherm0
(psia)
0.0001-0.05
0.0001-0.01
0.0001-0.05
0.0001-0.04
0.0001-0.03
0.0001-0.04
0.0001-0.05
0.0001-0.001
0.001-0.05
0.0001-0.015
0.0001-0.05
0.0001-0.05
"Reference 1.
'Each isotierm is of the form: We=kPm. (See textfor definition of terms)
Data are for adsorption on Calgon type "BPL" carbon (4 x 10 mesh).
"Equations should not be extrapolated outside these ranges.
4.6.3 Design Parameters
Typically, the size (and purchase cost) of carbon adsorber
system depends primarily upon four parameters:
1. The volumetric flow rate of the VOC laden gas
stream
2, The mass loading of VOC
3. The adsorption time
4. The working capacity of the carbon bed
The volumetric flow rate and mass loading of VOC are
the two most important factors is designing and costing
an adsorber system. The flow rate determines the size
of the vessels housing the carbon, the capacities of the
fan and motor required, and the diameter of the internal
ducting. The mass loading determines the carbon re-
quirement. The othertwo parameters, while less influen-
tial than flow rate and mass loading, do need to be
accounted for in any design and costing procedure.
These parameters are discussed in more detail in the
following section.
4.6.4 Pretreatment of the Emission Stream
Cooling. Adsorption of VOCs is favored by lower tem-
peratures. If the temperature of the emission stream is
significantly higherthan 130 °F, a heat exchanger may
be needed to cool the emission stream to 130°F or less.
4-29
-------
The temperaturei •
which is betow
essaiy. ,:
'
Dehumidification. Since vapor competes with the VOCs
in the emission stream for adsorption sites on the carbon
surface, emission stream humidity levels exceeding 50
percent (relative humidity) may limit efficiency for dilute
streams. However, if the emission stream HAP concen-
tration exceeds 1,000 ppmv, relative humidities above
50 percent can probably be tolerated.3 If the HAP con-
centration is less than 1,000 ppmv, relative humidities
should be reduced to 50 percent or less.
Dehumidification may be carried out by cooling and
condensing the water vapor in the emission stream. A
sheil-and-tube type heat exchanger can be employed
forthispurpose.RefertoSection4.8wherecalcuIational
procedures for sizing condensers are described,
Another alternative for dehumidification is adding dilu-
tion airtothe emission stream if the dilution air humidity
is significantly less than that of the emission stream.
However, since this will increase the size of the adsorber
system required, it may not be cost effective. Moreover,
since a carbon adsorber is a constant outlet device,
dilution air will decrease the removal efficiency.
less than
High VOC Concentrations. If flammable vapors are
present in emission streams that are mixtures of VOC
and air, the VOC content usually is limited to below 25
percent of the LEL for safety reasons. In some cases, it
can be increased to 40 to 50 percent of the LEL if proper
monitoring and controls are used. In addition, since high
bed temperatures may occur due to heat released
during adsorption, high VOC concentrations may need
to be reduced. In this handbook, it is assumed that the
VOC content will be limited to less than 25 percent of the
LEL. See Table 4.2-1 for a listing of LELs for common
organic compounds.
1,000 ppmv (toluene); thIis::|ia;|S||^^p|$d|^|^^j
fortoluene, which is I2,oo pprivpiiTJieJ
,,,, _ :......; •;:•";••;•.••"'•'•''-"•:'-'•>*:•':r: •**>w>&N:r:i!X::^
4.6.5 Typical Operational Characteristics,
Problems and Adsorber Types
In a properly operated carbon adsorberthe HAP effluent
emissions will tend to remain in the 50-150 ppmv range,
although effluent concentrations may be as low as 20-25
ppmv.2-3. This concentration usually will translate to 95-
99 percent efficiency depending on inlet loading. When
the working capacity begins to be approached, the
effluent concentration will increase significantly. This
increase is called breakthrough and results in much
higher emissions. The bed should be taken off-line for
desorption before the working capacity is approached.
Several operating problems can result in substantial
decreases in the HAP control efficiency. These prob-
lems include:
1. An increase in emission stream temperature
2. An increase in emission stream flow rate
3. An increase in HAP concentration
4. Loss of carbon adsorption activity due to heel
buildup
5. Deterioration of carbon bed due to aging
6. Incomplete capture of HAP from the source
Heel buildup refers to organic compounds left on the
carbon that do not desorb. The first five problems listed
above will lead to higher than normal HAP effluent
emissions. The sixth problem may be more difficult to
detect since it generally would not lead to higher effluent
emissions. Usually capture efficiency problems are de-
tected by an increase in fugitive HAP emissions or a
decrease in inlet HAP concentration.2
Carbon adsorption is used for pollution control and/or
solvent recovery in a variety of industries. It is usually a
batch operation and can involve multiple beds. Five
types of adsorption equipment are used in collecting
gases: (1) fixed regenerative beds; (2) disposal/re-
chargeable canisters; (3) traveling bed adsorbers; (4)
iluidized adsorbers; (5) chromatographic baghouses. Of
these five, the first two are the most common and are
discussed in detail below. The other three are men-
tioned primarily to inform the reader that other types of
adsorption systems are employed in industry.
4.6.6 Fixed Bed Regenerative Systems
Fixed bed regenerative units are used to control continu-
ous VOC laden streams with flow rates ranging from
about 2,000 acfm to over 200,000 acfm. These units can
efficiently operate at concentrations in the low ppmv
range or as high as 25 percent of the compound's lower
explosive limit (LEL). For most organic compounds, 25
percent of the LEL ranges from about 2,500 ppmv to
10,000 ppmv. See Table 4.2-1 for a listing of LELs for
common organic compounds. These adsorbers can be
operated in either intermittent or continuous modes. In
the intermittent mode, the adsorber removes VOC for a
specified time corresponding to the time during which
the source emits VOC. After the source has stopped
emitting VOC, the adsorber begins the desorption cycle.
This cycleconsists of three steps: (1) regeneration of the
4-30
-------
Figure 4.6-1. Typical two-bed regenerative carbon adsorption system.
Emission Stream
Condenser
Low-Pressure _
Steam
Adsorbers
X
Decanter,
Exhaust to
Atmosphere
carbon; (2) drying of the bed; (3) cooling of the bed to its
operating temperature which is usually around ambient
temperature. At the end of the desorption cycle (usually
1 to 1-11/2 hours), the bed sits Idle untilthe source again
begins to emit VOCs.
In continuous operation, multiple fixed bed adsorbers
are employed in parallel so that at least one bed is
always available to control the emission stream. A
typical two bed system is shown in Figure 4.6-1. The
operation of this system can be described as follows:
The VOC-laden gas Is introduced to the available bed
where VOCs are adsorbed on the beds surface. As the
adsorption capacity is approached, the effluent VOC
concentration increases significantly, indicating the
breakthrough point has been reached. The emission
stream is then directed to a parallel bed containing
regenerated adsorbent, which continues to control the
emission stream. Concurrently, the first bed is undergo-
ing a desorption cycle so that ft can control the emission
stream before breakthrough on the second bed is at-
tained. For any regenerative system, an off-line bed(s)
must be ready for use (i.,e. desorbed and cooled) before
breakthrough on the on-line bed(s) occurs. For control of
HAPs, the effluent concentration from each bed (HAP0)
should be monitored continuously.
These units normally are used to control continuous
streams over a wide range of flow rates and VOC
concentrations and commonly are employed at sites in
which the expected cleanup duration is relatively long.1-6"
Typically, the system consists of two or more carbon
beds. One bed will be adsorbing while the other(s) will be
either in a regenerative phase or idle. The adsorption
time of the on-line bed must be greater than or equal to
the regeneration time (i.e. regeneration, drying, and
cooling) of the off-line bed.
4.6.6.1 Fixed Bed Design
The design of a fixed-bed carbon adsorption system can
be performed in a two step process. (The procedure
below assumes a horizontal bed system). First, the
carbon requirement, C^, is estimated based on ex-
pected inlet HAP loading, the adsorption time, the num-
ber of beds, and the working capacity of the carbon. The
relationship is described in Equation 4.6-1.
where:
- MHApead(1 +ND/NA)
We
(4.6-1)
Nfc
NA
W.
= total amount of carbon required, Ibs
= HAP inlet loading, Ib/hr
= Adsorption time, hrs
= Number of beds desorbing
» Number of beds adsorbing
= working capacity of carbon, Ibs HAP/lb
carbon
If the value for M,^ is not given, ft may be obtained from
Equation 4.6-2 below:
M;
HAP
= 6.0x10* (HAP.)(Cy(DHAP)
(4.6-2)
where:
MHAP = HAP inlet loading, Ibs HAP/hr
HAP9 = HAP emission streamconcentration.ppmv
Qe = HAP emission stream flow rate, scfm
D^ = HAP densfty (gas), to/ft3
4-31
-------
For purposes of this report, DHAP can be estimated as:
Duia - PM/RT
where:
P
M
R
T
System pressure, atm (usually 1.0)
HAP molecular weight, Ib/lb-mole
Gas constant, 0.7302 ft3-atm/lb-mole °R
Temperature, °R
After obtaining the carbon requirement, the next step is
to size the vessels containing the carbon. The neces-
sary dimensions (Dv, Lv, and S) can be obtained from
Equations 4.6-3,4.6-4, and 4.6-5. Note that these equa-
tions do not provide the carbon bed dimensions, but
rather the vessel dimensions. They have been derived
assuming the carbon occupies 1 /3 of the vessel volume
and horizontal erection. For some applications, Equa-
tions 4.6-3 and 4.6-4 may yield unrealistic vessel dimen-
sions, in particular small vessel diameters coupled with
long vessel lengths.The reader can obtain more realistic
dimensions by increasing U although the value of Ue
should not exceed approximately 100 ft/s for most
cases. If unrealistic dimensions are still obtained after
adjusting U,, the reader should contact a vendor to
obtain more specific design information for a given
application.
0.127
(4.6-3)
Qea
where:
Dv = Diameter of vessel, ft
c'teq » Carbon required per vessel, Ibs
U, « Emission stream bed velocity, ft/min
(default - 85 ft/min)
Qg a * Emission stream flow rate per adsorbing
bed, acfm
(7.87)
c;
(4.6-4)
req
where: Lv = vessel length, ft
Q,, can be obtained from Qe and Te using the following
equation:
Q,,^Q8(T04-460)/537
Dv is generally limited to about 12 feet, while Lv rarely
exceeds 50 feet for shipping purposes. Once Dv and l^,
are known the vessel surface area, S, is calculated:
S = sDv (L 4- Dv/2) (4.6-5)
This calculations! procedure is accurate for a range of
vessel sizes bounded by a low value of 97 ft2 to a high
value of 2,110 ft2.
x«$ P.SCt;. ^_»*-»^jl'|i:ft:;:;W,l;:|l![(J!|:«*W.^J l£Pi«i£W. :>£f ,t,:Tf,!|Wf:«^IWP.ftf £jf P.»:'• fyftM^frfwfXgJ -
'>^M*:%&:&y::£¥::i^
0mmrn>m^mifm^m^^mmmMimm^iimm^mm!i^mm&
4.6.6.2 Carbon Adsorber Efficiency
Unlike most other add-on VOC control techniques, a
properly operated and maintained fixed-bed carbon
4-32
-------
Table 4.6-2. Carbon Adsorber System Efficiency Variables*11
Outlet Concentration
HAP (ppmv)
Adsorption Cycle Time
Regeneration Cyde Time0
9
For a carbon canister system, no steam regeneration or
cycle time occurs, and hence the values given in Table
4.6-2 do not apply. Removal efficiency estimates for
canister systems are typically incorporated into the
carbon requirement which is discussed in Section 4.6.9.1.
For purposes of this report, assume the removal effi-
ciency of a canister system is 90 percent, provided the
carbon requirement is sufficient.6
mssmmm^^«iSf»^m:mmmmsmmmmmmmmss&
Sg^S^PP^^^^^^^iP^
iMiiii^^iWsiiis*Kiwi
4.6.6.3 Steam Requirement for Regeneration
Carbon beds may be regenerated by various means;the
most common regenerant used is steam. Regeneration
with steam usually is followed by condensation. The
quantity of steam required for regeneration depends on
the required removal efficiency (or outlet concentration)
and on how much material is to be desorbed from the
bed. A certain amount of steam is required to raise the
bed to its regeneration temperature and provide the heat
of desorption. The majorportion of the steam flow, about
60 to 70 percent, acts as a carrier gas for the desorbed
VOCs. It is not cost-effective to achieve complete des-
orption; acceptable working capacities of adsorption
can be obtained without consuming large quantities of
steam. For solvent recovery systems a requirement of
0.25 to 0.35 Ib steam/lb carbon has usually been speci-
fied. For applications where outlet VOC concentrations
need to be fairly low (e.g., odor control), steam usage
ratios are higher.
In this handbook, it is assumed that with a steam ratio of
0.3 Ib steam/lbcarbon, a HAP outlet concentration of 70
ppmv can be achieved after regeneration, and with a
ratio of 11b steam/lb carbon, a HAP outlet concentration
of 10-12 ppmv can be achieved (Table 4.6-2). The
regeneration cycle time, 0^, is dependent on the time
4-33
-------
required to regenerate, dry, and cool the bed. The flow
rate of the steam used for regeneration can be deter-
mined using the following expression:
Q.
where:
Q.
NA[St(Cf8::>.>:3^:>;:^'!!!!'!^':l:>Sfe'-:::-:->
4.6,7 Evaluation of Permit Application
Compare the results from the calculated values and
reported values using Table 4.6-3. If the calculated
values of C , Dv, Lv, S, and Q, are different from the
reported values, the differences may be due to the
assumptions involved in the calculations. In this case,
the reviewer may wish to discuss specific design details
of the proposed system with the applicant.
If the calculated values agree with the reported values,
the design of the proposed fixed-bed system may be
considered appropriate based upon the assumptions
made in this handbook.
4.6.8 Capital and Annual Costs of Fixed Bed
Regenerative Adsorbers
The capital cost of a fixed bed system is primarily a
function of the amount of carbon necessary for control
and the cost of the vessels used to enclose the carbon.
This in turn, depends upon the amount of pollutant
introduced to the system. The auxiliary costs of a fixed
bed system such as fans, pumps, condensers, decant-
ers, and piping are usually factored from the costs of
carbon and vessels. The costing procedures for regen-
erative systems contained within this chapter apply to
horizontal adsorber vessels only. Reference 1 provides
sizing procedures for horizontal as well as vertical ves-
sels.
4.6.8.1 Costs of Carbon
This cost (C0, $) is the product of the initial carbon
requirement (C , Ib) and the cost of activated carbon
($/lb). The cost of activated carbon is about $2/lb.4
The cost of carbon is then :
c
where:
$2.00
(4.6-7)
Cc = carbon costs, 1989$
4.6.8.2 Vessel Costs
This cost (Cv) is primarily determined by vessel dimen-
sions, which in turn, depend upon the amount of carbon
contained per vessel, and the superficial gas velocity
through the bed, LL. The value of U, is typically estab-
lished empirically. For the purposes of this report, this
value is taken to be 85 ft/min. EF'A has developed a
correlation between S, calculated from Equation 4.6-5,
and vessel cost Cv, based upon vendor data and given
in Equation 4.6-8:
C =$271 S0-778
(4.6-8)
where:
Cv = vessel cost, fall 1989 $
and 97^8^ 2,110 ft2
Table 4.6-3. Comparison of Calculated Values and Value*
Supplied by Permit Applicant for Carbon Adsorp-
tion
Variable
Continuous Effluent Monitoring
Carbon Requirement, C^
Vessel Diameter, Dv
Vessel Length, L,
Vessel Surface Area, S
Steam regeneration rate, Q,
Calculated Value Reported
(Example Case) Value
Yes
4,790 IDS
1.68ft
107ft.
569ft2
6.84 Ib/min
4-34
-------
The vessel costs given above are assumed to be con-
structed with 304 stainless steel, which is the most
common material used when fabricating adsorber ves-
sels. However, other materials may be substituted for
304 stainless steel. This substitution will not affect the
design equations presented above, but will change the
vessel costs. Table 4.6-4 provides multiplication factors,
Fm, to be used with other materials. Multiply Cv by Fro to
obtain a vessel cost estimate for the materials given in
Table4.6-4.
4.6.8.3 Purchased Equipment Cost
The equipment cost of an adsorber system can be
estimated as a function of the sum of Cv and C and
ductwork and damper costs as given in Equation 4.6-9.
EC = RJC. + C (NA+ND)] (4.6-9)
+ Ductwork and damper costs
where:
EC = equipment cost of adsorber system
R = 5.82 Q-°133
•
Table 4.6-4. Multiplication Cost Factors for Materials
Material Factor, F_
304 stainless steel
316 stainless steel
Carpenter 20 CB-3
Manel-400
Nickel - 200
Titanium
1.0
1.3
1.9
2.3
3.2
4.5
•Reference 1.
Rc = Factdr to account for auxiliary equipment
cost. This cost includes fans, pumps, con-
denser, decanter, stack, instrumentation, and
internal piping. Note that this correlation
uses flow rate in acf m, not scfm and does not
include the cost of ductwork or dampers.
The purchased equipment cost (PEC) is then estimated
as the sum of the equipment cost estimated from Eq,
4.6-9 and the cost of sales tax, and freight. Factors used
to estimate sales tax and freight costs are given in Table
4.6-5.
Table 4.6-5. Installation Factors for Fixed led Carbon Adsorbers*
Cost Item
Cost Factor
Direct Costs
Purchased Equipment Cost
Adsorber and auxiliary equipment1'
Taxes
Freight
Purchased Equipment Cost, PEC
Installation Direct Costs
Foundations and supports
Erection and handling
Electrical
Piping, installation, and painting
Total Installed Direct Cost
Site preparation
Buildings
Total Direct Cost, DC
Indirect Costs
Engineering and supervision
Construction, field expenses, and fee
Start-up and performance test
Contingency
Total Indirect Costs, 1C
Total Capital Cost, TCC = DC + IC = 1.61 PEC + SP + BIdg.
As estimated, EC
0.03 EC
108 EC
0.08 PEC
0.14 PEC
0.04 PEC
0.04 PEC
0.30 PEC
As required, SP
As required, BIdg.
1.30 PEC+ SP + Bidg.
0.10 PEC
0.15 PEC
0.03 PEC
0.03 PEC
0.31 PEC
•Reference 1. .
"The equipment cost (EC) usually includes instrumentation. If not included, estimate Instrumentation costs at 10 percent of the EC.
4-35
-------
Tab!* 4.6-6, Example Casa Capital Costs
Cost Item
Factor
Cost
Direct Costs
Purchased Equipment Costs
Adsorber and auxiliary equipment, EC
Taxes
Freight
Purchased Equipment Cost, PEC
As estimated, EC
0.03 EC
0.05 EC
1.08 EC
$137,000
$ 4,110
$ 6,850
1148,000
Installation Direct Costs
Foundations and supports
Erection and handling
Electrical
Piping, Installation, and painting
Total Installed Direct Cost
Site preparation
Buildings
Total Direct Cost
Indirect Costs
0.08 PEC
0.14 PEC
0.04 PEC
0.04 PEC
0.30 PEC
As required, SP
As required, Bldg
1,30 PEC+ SP
4- Bidg.
$ 11,800
$ 20,700
$ 5,920
$ 5,920
""
$192.000 +
SP 4- Bldg.
Engineering and supervision
Construction, field expenses, and fee
Start-up and performance test
Contingency
Total Indirect Cost
Total Capital Cost, TCC
0.1 OPEC
0.1 SPEC
0.03PEC
0.03PEC
0.31 PEC
1.61 PEC + SP
+• Bldg.
$ 14,800
$ 22,200
$ 4,440
$ 4,440
$ 45,900
$238,000 +
SP + Bldg.
4.6.8.4 Total Capital Cost
The total capital cost (TCC) is estimated from purchased
equipment cost, PEC, through direct and indirect instal-
lation cost factors. Table 4.6-5 provides the breakdown
of the direct and indirect cost factors for fixed bed carbon
adsorbers. These cost factors reflect "average" condi-
tions and may vary appreciably from site to site. Also, the
cost of site preparation and buildings will depend upon
site specific factors and are not included in this analysis.
Example Case,
The carbon cost, Cc, is calculated, from Eq* 433-7 as:
C0 * $3.00(4,790} « $9,580
The vessel cost, C^ is calculated from Eq, 4,©-8 as;
Cv » $271 (669)*™* $37,700 ' \,
Equation 4,8-9 is then used to calculate tha equip-
ment cost, EC. For example purposes, assume
ductwork and damper costs are equal to zero;
4-36
-------
Table 4,6-7. Unit Cost Factors for Carbon Adsorption Annual Costs*
Cost Element
Unit Cost Factor
Direct Annual Cost. DAC
Utilities:
Steam (C4)
Cooling water
Electricity
Operating:
Operating labor
Supervisory labor
Maintenance:
Labor
Materials
Replacement:
Carbon"
Labor
Solid waste disposal (Canister systems only):
Disposal cost
Transportation
Indirect Annual Costs. IAC
Overhead
Property tax
Insurance
Administrative
Capital recovery0 (fixed-bed)
Capital recovery0 (canister)
Canister expense1*
Recovery Credits
S6.00/103 Ibs steam
$0.20/10* gal
$O.OS9/kWh
$12J6/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
$2.00/!b
100% of replacement carbon
$65/canister
As appropriate
0.60 (Operating + maintenance)
1 percent of TCC
1 percent of TCC
2 percent of TCC
0.1628 (TCC - 0.05 (C,^) - 1.08 (C0))
0.1628 (Auxiliary eq. cost)
As applicable
•Reference 1.
b Reference 4.
"Capital Recovery Factor (CRF) • ,l(1 ±P,
where: i- interest rale (10 percent assumed)
n = system lifetime, yrs
For a 10-year life* and 10 percent interest rate, the CRF equals 0.1628. For canister systems, see Section 4.6.10.
""For canister systems only.
4.6.8.5 Fixed-Bed Carbon Adsorption Annual Cost
Estimates
The annual operating cost of regenerative fixed-bed
systems is comprised of three elements: 1) direct costs;
2) indirect costs; 3) recovery credits. Table 4.6-7 pre-
sents the factors used to estimate direct and indirect
annualized costs. Table 4.6-8 gives the equations used
to estimate selected components of annual cost. Since
the number of equations to estimate the carbon adsorp-
tion annualized cost is large, Table 4.6-8 contains a
summary of these equations. However, Table 4.6-8
does not include all annual cost items (e.g., operating
and maintenance labor).
Direct Annual Costs. Direct costs are those which are
related in some manner to the quantity of gas processed
by the control system. This includes costs for utilities
(steam, electricity, water, etc.) raw materials, mainte-
nance materials, replacement parts, operating, supervi-
sory, and maintenance labor.
Steam costs are calculated using Equation 4.6-10:
QS(60)(HRS)(P,)/1,000
(4.6-10)
4-37
-------
Table 4.6-8. Selected Equations for Carbon Adsorption Annual Cost Estimate
Cost Item
Equation
I. Direct Costs
1. Steam Costs, Ct
2. Cooling Water Cost, COT
3. Electricity
a. Pressure drop, Pb, for Regenerative systems
Cs = Qs(60) (HRS) (Ps) /1.000
where: Qs = steam requirement, Ibs/hr
HRS = operating hours per year, hr/yr
Ps = Steam price, $/103 Ibs
COT = 3.43(C,/PS)PW
where: P^ = cooling water price, $/103 gal
(assumed to equal $0.20/103 gal)
Pb = [0.03679 Ue +-1.107 x 10-4 Ue2] ^
where: t b = bed thickness, ft carbon
oru = °-0333 °req
b. Pressure drop, Pe, for Canister systems
c. System fan horsepower, hpsl
d. Bed drying/cooling fan, P^
e. Cooling water horsepower,
f. Required electricity usage per year, Fp
4. Carbon Replacement Cost, CRC
(Note: There is no carbon replacement cost for Canister
carbon systems.)
II. Recovery credits, Q^ (Ib/yr)
PC = 0.0471 Qe,a + 9.29 X 1 0
where: Q^a = emission stream flow rate, per bed fP/min,
hptf = 2.5x10^ [(Pb or P0) + 1]QM
PM = 1.86x10-(FRdc,)(Pb+1){0dl:f)
where: P^ = power requirement for fan, kWh/yr
hP<5«p = [2.52x10'
-------
where:
Cs = steam cost ,$/yr
Qs = steam requirement obtained in
Section 4.6.6.3
MRS = annual operating hours, hr/yr
Ps = steam price, $/1,000 Ib (Table 4.6-7)
Cooling water costs are calculated using Equation
4.6-11:
= 3.43(CS/PS)(PJ
(4.6-11)
where:
GO* = Cooling water cost, $/yr
POT = Cooling water price, $/103 gal (Table 4.6-7)
Several steps are necessary to obtain the electricity
cost. First, the pressure drop through the bed, Pb, is
calculated using Equation 4.6-12.
P. « [0.03679U +1.107x
[0.0333
(4.6-12)
where:
Pb = pressure drop through the bed, in, HO
Ua = superficial velocity, ft/s (default = 85 ft/see)
C' = carbon requirement per bed, Ib
Lv = vessel length, ft -•„
Dy = vessel diameter, ft
Next, the system fan horsepower, hps{, is calculated:
hpsf - 2.5 x 10-* [Q J [Pb + 1] (4.6-13)
The horsepower requirement for the bed drying/cooling
fan is computed in a similar manner. The bed pressure
drop (Pb) is identical to that given above, but the operat-
ing time and gas flow rate are different. The operating
time per year is given by:
= 0.4(ereg)(NA)(HRS)/0a
(4.6-14)
The gas flow rate typically falls between 50 and
150 ft3/lb carbon. Taking the midpoint of this to obtain
the flow rate yields:
= (iooft3/ib)(qeq)/0dry_cool
(4.6-15)
This value is substituted into the equation below to
obtain the power requirement for this fan:
PM = 1.86 x 1O-4 (FRdof)(Pb + 1)(9J kWh/yr (4.6-16)
The horsepowerrequirementforthe cooling water pump,
hpOTp, is then calculated using Equation 4.6-17.
hPc
(4.6-17)
where:
hp
fr
cwp
cooling water pump horsepower, hp
cooling water flow rate, gal/min (3.43 Qs)
required head (usually 100 ft. of water) at
60°F
S = specific gravity of fluid relative to water
(usually 1.0)
n = combined pump motor efficiency
(usually 0.65)
The electricity usage is calculated using Equation
4.6-18.
FD = 0.746 [hps
] HRS + Pdd (4.6-18)
where:
Fp = required electricity usage, kWh/yr
HRS = operating hours per year, hr/yr
Finally, the cost of electricity is calculated as the product
of the annual electricity cost and the required electricity
usage: ,
AEC « $0.059
(4.6-19)
Carbon Replacement Cost Since the carbon has a
different economic life than the rest of the adsorber
system, the replacement cost must be calculated as
follows:
CRC0 = CRF0(1.08Ce + Ctt|)
where:
CRC0 = carbon replacement cost, $/yr
CRFC = capital recovery factor for carbon
C = initial cost of carbon, $
'ol
= replacement cost of carbon, $
CRF0 equals 0.2638 for a five-year carbon life. If the
carbon has a shorter lifetime, a different factor using the
formula given in Table 4.6-7 should be substituted. The
cost of carbon (Cc) is obtained from Equation 4.6-7, and
C^, is estimated as $0.05 Creq.
The cost of operating labor consists of operating labor
and supervisory labor. A f actorof 0.5 hr/shift is estimated
as the operator time. The cost of operator labor is the
product of the wage rate and the operator time/yr. The
supervisory labor cost is estimated as 15 percent of the
operator labor cost.
The cost of maintenance consists of maintenance labor
and materials. A factor of 0.5 hr/shift is estimated as the
maintenance time. The cost of maintenance labor is
estimated as the product of the wage rate (110 percent
of the operating wage rate) and the maintenance time
4-39
-------
per year. The cost of materials Is estimated as 100
percent of the maintenance labor cost.
Indirect Annual Costs. These costs are usually consid-
ered "fixed" costs, in that they are not usually related to
the size and operation of control equipment and would
have to be paid even if the system shut down. This
includes costs for overhead, property taxes, insurance,
and capital recovery. The capital recovery cost must be
offsettoaccountforthecarbon replacement cost. Tables
4.6-7 and 4.6-8 present the necessary equations to
estimate direct and indirect annual costs for regenera-
tive systems.
Recovery Credits. To calculate recovery credits, the
quantity of recovered product that can be sold and/or
recycled to the process has to be calculated. Use the
following equation:
Q« - (MHAP)(HRS)(RE/100)
where:
(4.6-20)
CL
the quantity of recovered product, Ib/yr
To obtain the direct
COStS Oil St&elftt i!X5
replacement^' operating a^iSiii^^i'^^l^i^^^:
ingthelnformatfonprovided^
we have:. .. ".
1. Steam'Cost,; 'y-'y^.'-^sn^^^^^^K^^^^i^
c. -
"
2. Cooling water» ?:.£^i2il;3|l|||*ii|
/g\ D ' •— - fri't^l^^iO^^^^f^^i^^^f^ii''.'-
iiit.ia.--' •:•!•: :•'•;.-. ,s, .-,•.•.. ;vX':^:'!^'v-vx-^-H^*ivivMv;i:v,
-------
4.6.9 Carbon Canister System Design
Carbon canister systems are normally used for control of
intermittent lower volume air streams and are generally
employed on sources where the expected volume of
VOC recovered is fairly small.1'8 Carbon canister sys-
tems cannot be described at the site, and must be either
landfilled, or shipped back to the vendors central facility
fordesprption. therefore, there are no recovery credits
for canister systems. In addition, the effluent from can-
isters is usually not monitored continuously (via an FID,
for example), meaning that operators do not have an
indication of breakthrough.
4.6.9.1 Carbon Requirement
The fundamental variable to be determined in designing
a canister system is the carbon requirement. This is
because canister systems are fairly self-contained units
coming equipped with vessels, piping, flanges, etc.
Because canister systems cannot be desorbed of the
site, the calculation of thecarbon requirement, Cra(l, must
necessarily be based on the expected volume of HAP
recovered, or the total adsorption time necessary to
remove the HAP. Thus, the adsorption time for canister
systems has a somewhat different meaning than that for
regenerative systems.
The carbon requirement for canisters can be estimated
in an identical fashion to the fixed-bed system using
equation 4.6-21 below:
Creq = MiWJk. (1 + ND/NA) (4.6-21)
We
carbon requirement, Ibs
VOC inlet loading, Ib/hr
total adsorption time, hrs
W_ = working capacity, Ibs HAP/lbs carbon
ND = number of beds describing
NA = number of bed adsorbing
where: C
e.
HAP
•:4
-------
Example Case (Com.)
Use Eq. 4,6-22 to obtain the carbon requirement,
'OK?
(tg.1 lb/hf)(4Q Hurs)
0- -
"* 0.085 Ib acetone/to carbon
Gm * 5,700 Ibs carbon .
The working capacity value W, has been calculated
using Table 4,6-1 .The required canister: number
(RON) Is calculated by dividing c^ by the eartjon
contained in a single canister. For purposes of thfe
example case it is assuraW that 150 Ibs carbon are
contained within a single canister.
RCN- 5,700lbs/1 soibs/canister
» 38canlsters ' - ' %, "' -
4.6.9.2 Evaluation of Permit Application
Compare the results from the calculated values and
reported values using Table 4.6-9. If the calculated
values of C^ and RCN differ from the reported values,
the differences may be due to assumptions involved in
the calculations. In this case, the reviewer may wish to
discuss specific design details of the proposed system
with the applicant.
If the calculated values agree with the reported values,
the design of the proposed canister system may be
considered appropriate based on the assumptions used
in this handbook.
4.6.10 Capital and Annual Costs of Canister
Systems
4.6.10.1 Capital Costs for Canister Systems
The capital cost of a canister system is typically a
function of the required number of canisters, RCN.
Equipment costs (EC) for Calgon's Ventsorb canister,
common in industry, are provided in Table 4.6-10. This
cost includes the carbon, vessel, and necessary con-
nections, but do not include freight, taxes, or installation
charges. The canister costs given in Table 4.6-10 are
Table 4.6-9. Comparison of Calculated Values and Values
Supplied by tha Permit Applicant for Carbon Can-
Is lor Systems
Parameter
Calculated
Value Reported
(Example Case) Value
Adsorption time, 8^ 40
U^, tb/hr 12.1
Carbon Requirement, C^ 5,700
Required Canister Number, RCN 38
estimated based upon the cost of Calgon's "BPL" carbon
(4x10 mesh), a commonly used industrial adsorbent.
The costs are given in April 1986 $ and should be
escalated to current costs using a factor of 1.1. A factor
of 1.08 is used to estimate the costs of taxes and freight.
The canister equipment cost (CEC) includes the equip-
ment cost and the cost of any necessary auxiliary
equipment. Refer to section 4.12 for auxiliary equipment
costs. The cost of materials and labor is significantly less
for canister systems than for fixed bed systems. Twenty
percent of the sum of the canister costs can be used to
estimate the total capital cost (TCC) of a canister system
as shown by Equation 4.6-23. The canister equipment
cost is multiplied by a factor of 1.1 to obtain current
canister costs.
where:
TCC
CEC
Aex
TCC .1.2 [CEC]
Total Capital Cost
Canister Equipment Cost
(1.1)(1.08)(RCN)[EC]
Auxiliary Equipment Cost
(4.6-23)
4.6.10.2 Annual Costs for Canister Systems
The annual cost of a canister system is comprised of
direct costs and indirect costs. Direct costs are those
which relate to system flow rate and include utilities, raw
materials, and operating and maintenance costs. Indi-
rect costs are considered fixed and include overhead,
property taxes, insurance, and capital recovery.
Table 4.6-10. Equipment Costs for Canister Units*
(April 1986 $)
Quantity Equipment Cost EC, each"
1-3
4-9
10-29
£30
$687
$659
$622
$579
•Reference 1.
The canister equipment cost, CEC, is obtained by multiplying the
appropriate equipment cost, EC, by the required canister number,
RCN, Costs are quoted for canisters containing 150 Ibs of carbon.
These costs do not include taxes and freight charges. Current prices
for these canisters are about 10 percent higher than quoted in this
table.
4-42
-------
For canister systems, utility costs include electricity and
solid waste disposal. To estimate the pressure drop
through the canister, use the following equation:
PC =0.0471 Qe,a+9.29x 10"4[Qe,af
where:
(4.6-24)
P0 = total canister system pressure drop, in
Qe.a = emission stream flow rate per canister,
acfm
Once this value is obtained, it can be substituted into
Equation 4.6-25:
hPsf . 2.S x 1 O-4 [P. + 1] [QJ (4.6-25)
where:
Qea = total emission stream ftowrate, acfm
ea
P0+1 = total pressure drop of canisters and
ductwork
To obtain the required electricity usage, use Equation
4.2-26:
= 0.746 [hpjHRS
(4.6-26)
The value of Fp is then multiplied by the electricity cost
given in Table 4.6-7 to obtain annual electricity costs.
The cost of solid waste disposal can vary significantly.
For purposes of this report, a cost of $65/canister is
appropriate (Reference 1).
Carbon canister systems typically dp not require any
operating labor, supervisory labor, maintenance labor or
maintenance materials.1 Therefore, these costs are not
considered in the example case illustration. There are
also no overhead costs for a canister system since
overhead costs are based on operating and mainte-
nance costs.
Indirect costs consist of overhead, property tax, insur-
ance, administrative and capital recovery costs. Table
4.6-7 presents the necessary factors and equations to
estimate direct and indirect annualized cost for canister
systems. The major difference in these factors for can-
ister systems vs. fixed-bed systems is the capital recov-
ery factor.
The capital recovery factor is a function of the interest
rate and the expected equipment lifespan, in most
cases. This factor reflects the fact that most companies
incur an opportunity cost when financing the installation
of control equipment. Typically, the opportunity cost
duration equals the expected equipment lifespan, and
the annual interest rate is usually estimated to be 10
percent. For example, fixed-bed carbon adsorbers have
typical lifespans often years, and are usually installed in
plants for control of a continuous process. The process
is typically expected to operate at least as long as the
control device. Forcanister systems, however, the usual
cleanup time is far less than ten years, meaning the VOC
control device lifespan will be significantly less than the
fixed-bed expected lifespan. Forthis reason, the carbon
canister unit costs should be expensed, not capitalized.
That is, the initial cost of the canister unit minus the
auxiliary equipment cost should be included as an an-
nual cost. The cost of auxiliary equipment should be
capitalized using the CRF given in Table 4.6-7.
4-43
-------
Note: Forthfs sample,
considered equal to zero
UVHIE»UC;Icu cx(uai lu z.civf, incicn-'iej tner© is no
capita!lecovery cost of auxBi|^^ii|||||j||!|||K||
Total Indirect Costs »
Total Annual Costs «
4.6.11. References
1. U.S. EPA. OAQPS Control Cost Manual. Fourth
Edition, EPA 450/3-90-006 (NTIS PB90-169954).
January 1990.
2. Memorandumwithattachments.CarlosNune'z,U.S.
EPA, AEERLto Michael Sink, PES. October 1989.
3. Memorandum with attachments. Karen Catlett, U.S.
EPA, OAQPS to Carlos Nunez, U.S. EPA, AEERL.
November 1989.
4. Telecon. Michael Sink, Pacific Environmental Ser-
vices, Inc. to Al Roy, Calgon Corp. June 19,1989.
5. PES, Inc. Company data for the evaluation of con-
tinuous compliance monitors.
6. U.S. EPA. Soil Vapor Extraction VOC Control Tech-
nology Assessment. EPA-450/4-89-017 (NTIS PB
90-216995). September 1989.
7. U.S. EPA. Handbook: Control Technologies forHaz-
ardous Air Pollutants. EPA 625/6-86-014. (NTIS
PB91-228809) Cincinnati, OH. September 1986.
8. Telecon, Michael Sink, Pacific Environmental Ser-
vices, Inc. to U. Sen Gupta, Calgon. July 2,1991.
9, U.S. EPA. Carbon Adsorption for Control of VOC
Emissions: Theory and Full Scale System Perfor-
mance. EPA-450/3-88-012, Research TrianglePark,
NC. June 1988.
4.7 Absorption
Absorption is an operation in which one or more compo-
nents of a gas mixture are selectively transferred into a
relatively nonvolatile liquid. Absorption of a gaseous
component by a liquid occurs when the liquid contains
less than the equilibrium concentration of the gaseous
component. The difference between the actual concen-
tration and the equilibrium concentration provides the
driving force for absorption. The absorption rate de-
pends on the physical properties of the gaseous/liquid
system (e.g., diffusivity, viscosity, density) and the ab-
sorber operating conditions (e.g., temperature, flow
rates of the gaseous and liquid streams). It is enhanced
by towertemperatures, greater contacting surface, higher
liquid-gas ratios, and higher concentrations in the gas
stream.1-2**"
Absorption can be physical or chemical. Physical ab-
sorption occurs when the absorbed compound simply
dissolves in the solvent. When a reaction occurs be-
tween the absorbed compound and the solvent, it is
termed chemical absorption. Liquids commonly used as
solvents for organic and inorganic compounds include
water, mineral oils, nonvolatile hydrocarbon oils, and
aqueous solutions (e.g., sodium hydroxide).
The design of an absorption system generally is consid-
ered somewhat more complex than the design of other
vapor control techniques. This complexity is due largely
to the two phase (gas and liquid) flow that characterizes
these systems. The design parameters for an absorber
system are dependent on such factors as equilibrium
concentrations, packing constants, and absorption fac-
tors. These factors in turn are dependent upon specific
HAP compounds and emission stream parameters which
will vary from application to application. Therefore, to
include all the necessary data within this section is not
possible. Instead, most of the necessary data are in-
cluded in Appendix C.7. Additional information on pack-
ing constants can be found in References 1,2,6, and 14.
The types of equipment commonly used for gas/liquid
contact operations include packed towers, plate or tray
towers, spray chambers, and venturi scrubbers. These
devices are designed to provide maximum contact be-
tween thegas and liquid streams inorderto increase the
mass transfer rate between the two phases. A packed
tower is filled with packing material that is designed to
expose a large wetted surface area to the gas steam and
is the focus of the discussion below. Plate towers use
plates or trays that are arranged so that the gas stream
is dispersed through a layer of liquid on each plate.
Bubble-cap plates have been widely used; other types
of plates include perforated trays and valve trays. Plate
towers may be encountered in some permit applica-
tions. These are typically designed using a theoretical
stage concept. Refer to References 1, 2, and 10 for
further discussion. In a spray tower, the gas mixture is
contacted with a liquid spray. In a venturi scrubber, the
gas and liquid streams come into contact at the throat of
the venturi nozzle; venturi scrubbers are typically used
for removal of paniculate matter (see Section 4.11).
Figure 4.7-1. Typical countercurrent packed column absorber.
Emission
Stream Outlet
Solvent Inlet
Packing
Emission Stream
Inlet
Solvent Outlet
4-44
-------
Several new packing types are used in absorber sys-
tems. These packings tend to increase liquid/gas con-
tact relative to older packings and result in smaller
packing volumes and towers. Information on cost and
packing constants of these new types was requested,
but most vendors currently view this information as
proprietary. Such information is thereforeiiot included in
this section. The reader should contact appropriate
packing vendors directly to obtain specific information
for a given application.
Several different configurations of absorber systems are
used for controlling vapor emissions. The simplest con-
figuration is one in which the solvent (usually water) is
used on a once-through basis, and is then either dis-
charged to a wast ewater treatment system or introduced
as a process water stream (see Figure 4.7-1). The
possibility of using solvents other than wateron a once-
through basis may exist when fresh solvent is available
in large quantities as a process raw material or fuel.
Another configuration involves using the solvent (usu-
ally water) on a once-through basis and stripping it
(reverse of absorption) before discharging. In yet an-
other configuration, an organic liquid is used as a solvent
and recycled to the absorber after being stripped.
The efficiency of absorption for removing pollutants from
a gaseous stream depends on several factors, including
(a) solubility of the pollutant in a given solvent, (b)
concentration, (c) temperature, (d) flow rates of
gaseous and liquid streams (liquid to gas ratio), (e)
contact surface area, and (f) efficiency of stripping (if
solvent is recycled to the absorber).
Determination of the absorber system variables (ab-
sorber column diameter, height, etc.)is dependent on
the individual vapor/liquid equilibrium relationship for
the specific HAP/solvent system and the type of ab-
sorberto be used (packed or platetower, etc.). Note that
equilibrium data may not be readily available for uncom-
mon HAPs.
Detailed design procedures for all types of absorbers
are not appropriate for this handbook; therefore, impor-
tant design considerations for one type of absorber will
be discussed briefly. Since packed towers commonly
are used in air pollution control, the discussion will be
based on packed tower absorbers. For illustration pur-
poses, a simple configuration is chosen for the absorber
system: a packed tower absorber using 2 inch ceramic
Raschig rings asthe packing material with water used as
the absorbent on a once-through basis. The effluent
from the absorber is assumed to be discharged to a
wastewater treatment facility. The treatment in the fol-
lowing subsections is equally applicable to both organic
and inorganic vapor emissions control. (For more infor-
mation on gas absorption, see References 1,2,3, and
14.)
As indicated in Chapter 3, absorption is the most widely
used control method for inorganic vapor emissions;
therefore, Emission Stream 5 containing inorganic va-
pors will be used in the example case to illustrate the
calculation procedures. Worksheets and necessary data
for calculations are provided in Appendix C.7
4.7.7 Data Required
The Data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form and the
required HAP control as determined by the applicable
regulations.
In the case of a permit review for an absorber, the
following data outlined below should be supplied by the
applicant. The calculations in this section will then be
used to check the applicant's values.
Absorption system variables at standard conditions (77°F,
1 atm):
Reported removal efficiency, REr H6d, percent
Emission stream flow rate, Q8,sctrn
Temperature of emission stream, Te, ^P
Molecular weight of emission stream, MW
(Ib/lb-mole)
Specific HAP
HAP concentration, HAPB, ppmv
Solvent used
Slope of the equilibrium curve, m
Solvent flow rate, L^, gaVmin
Density of the emission stream, De, Ib/ft3
Schmidt No. forthe HAP/emission stream and HAP/
solvent systems, Sc^, Sc, (To calculate Sca or
ScL, see References 1 ora for viscosity, density,
and diffusivfty data.)
Properties of the solvent:
Density, DL, Ib/ft3
Viscosity, u^, centipoise
Type of packing used
Packing constants a, b, c, d, e, Y, s, g, r
Column diameter, D^. , ft
Tower height (packed), «„,„,„, ft
Pressure drop, Ptow, in. H2O
4.7.2 Absorption System Design Variables
In absorption, the removal efficiencies (or outlet concen-
trations) are limited by the driving force available from
4-45
-------
gas to the liquid phase. The driving force for a given set
of operating conditions is determined by the difference
between the actual HAP concentrations in the gas
stream and solvent and the corresponding equilibrium
concentrations.
When the slope (m) of the equilibrium curve is small for
a given HAP/solvent system, indicating that the HAP is
readily soluble in the solvent, the driving force for ab-
sorption is large and absorption occurs readily. On the
other hand, if m Is large (e.g., >50), the HAP is not readily
soluble in the solvent and the driving force for absorption
Is small; therefore, long contact times, tall absorption
towers, and/or high liquid-gas ratios are required for
adequate performance (high removal efficiency and/or
low outlet concentrations). Hence, as a conservative
guideline, assume that if m is greater than about 50 for
a given HAP/solvent system at atmospheric pressure,
then high removal efficiencies (~99 percent) are not
possible.
4.7.3 Determination of Absorber System
Design and Operating Variables
In most applications involving the absorption of a gas-
eous pollutant from an effluent gas stream, the inlet
conditions (flow rate, composition, andtemperature) are
usually known. The composition of the outlet gas is
specified by the control requirements. The conditions of
the inlet liquid are also known. The main objectives,
then, in the design of an absorption column will be the
determination of the solvent flow rate and the calculation
of the principal dimensions of the equipment (column
diameter and height to accomplish the absorption op-
eration) for a selected solvent.
To keep the discussion simple, the following assump-
tions are made: (1) there are no heat effects associated
with the absorption operation, and (2) both the gas and
liquid streams are dilute solutions (i.e., flow rates are
constant throughout the absorption column and the
equilibrium curve can be approximated as a straight
line). AH of the data (e.g., packing factors, Schmidt
numbers, etc.) required in the calculation of the design
variables can be found in References 1,3,4,5,11, and
14. All data required for the example case illustration can
be found In Appendix C.7.
4.7.3.1 Solvent Flow Rate
The quantity of solvent to be used is typically estimated
from the minimum liquid-gas ratio as determined from
material balances and equilibrium considerations. As a
rule of thumb for purposes of rapid estimates, it has
frequently been found that the most economical value
forthe absorption factor will be in the range from 1.25 to
2.O.8-10 The absorption factor quantifies the relationship
between liquid and gas molar flow rates. For purposes
of this report the value will be assumed to equal 1.6.
(4.7-1)
Figure 4.7-2. Flooding, correlation In randomly packed towers.
1.0
Q
o£ 0.1 j
s:
i
0.01
0.001
11
0.01 0.045 0.1
1.0
10.0
where:
AF
G!
absorption factor (usually between 1.25 and
2.0)
IO| = liquid (solvent) flow rate, Ib-moles/hr
m
raol
gas stream flow rate, Ib-moles/hr
slope of the equilibrium curve
The value of m is determined from the equilibrium data
at a specific temperature level for the HAP/solvent
system under consideration. (See References 1,4 and
5 for equilibrium data for specific systems. For informa-
tion on other systems, see References 1,3,6, and 14.)
Assuming a value of 1.6 for AF, use Equation 4.7-1 to
calculate the solvent flow rate:
L = 1.6 m G (4.7-2)
The variable Gmol can be expressed in terms of Qe as
follows:
GmQl = 0.155QB (4.7-3)
Note that Lmol can be converted to gal/hr basis as follows:
L^, - [Lmo, x MW^, x (1/DU) x 7.48] /60 (4.7-4)
where:
L.gai = solvent flow rate, gal/min
MW . rt = molecular weight of solvent, Ib/lb-mole
D,
•• density of solvent (liquid), Ib/ft3
4-46
-------
The factor 7.48 is used to convert from IP to gal. basis.
For water as the solvent, D,= 62.43 Ib/ft3 and MWM. =
18Ib/lb-mole1;then:
where:
0.036 L
ffl0l
(4.7-5)
4.7.3.2 Column Diameter
Once the gas and liquid streams entering and leaving
the absorber column and their concentrations are iden-
tified, flow rates calculated, and operating conditions
(type of packing) determined, the physical dimensions of
the column can be calculated. The column must be
sufficient diameter to accommodate the gas and liquid
streams.
The calculation of the column diameter is based on
flooding considerations, the usual operating range be-
ing taken as 60 to 75 percent of the flooding rate.
Flooding is defined as the point where the gas flow
through the column is of such high velocity that it
impedes the water flow in the column. One of the
commonly used correlations in determining the column
diameter is shown in Figure 4.7-2.* The procedure to
calculate the column diameter is as follows: Rrst, calcu-
late the abscissa (ABS):
ABS = (L/G)(DQ/DL)05
(4.7-6)
where:
L
G
DL =
D,. =
solvent flow rate, Ib/hr [L = (MWsohent)(Lmol)]
gas stream flow rate, Ib/hr [G - (MWe)(Gmol)]
density of liquid solvent, Ib/ft3
density of emission stream, Ib/ft3
The density of a gas, DG, can be approximated using the
formula:
DG = PM/RT
density of gas, Ib/ft3
P = pressure, atm (usually 1.0)
M = molecular weight of gas, Ib/lb-mole
R = gas constant, 0.7302 ft3 atm/lb-mole °R
T = temperature, °R
The values for the variables L and G can be calculated
by multiplying L^and G^, with their respective molecu-
lar weights. Then proceed to the flooding line in Figure
4.7-2 and read the ordinate (ORD), and solve the ordi-
nate expression for G^, at flooding:
Thus,
where:
. KQ.jp (a/e3) (u^)] / DGDLga (4.7-7)
= [ORD DGDLgc/ (a/e3)
(4.7-8)
gas. stream flow rate based on column
cross sectional area (at flooding condi-
tions), Ib/ft2-sec
a,e = packing factors (see Appendix C.7 or Ref-
erence 11)
u^ = viscosity of solvent, centipoises
gc = gravitational constant, 32:2 ft/sec2
Assuming f as the fraction of flooding velocity appropri-
ate for the proposed operation, the gas stream flow rate
(based on cross-sectional area) can be expressed as:
= f G
araa,f
(4.7-9)
The usual column operating range for f is taken as 0.60
to 0.75. Calculate the column cross-sectional area by
the following expression:
(4.7-10)
(4.7-11)
The column diameter is then determined by:
where:
= column diameter, ft
4-47
-------
Figure 4.7-3. Relationship between N^, AF, and Efficiency.
48
10 100 1,000 10,000
HAP,/HAP0
Example Case (Cont.)
From Figure 4.7-2, at ABS - 0.04S, the value of
ORD at flooding conditions is about 415; For 2-Jnch
ceramic Raschig rings, from Reference 11 or
Appendix C,7; x •
a
e
Also,
Thus,
28
0,74 '
« 32.2 Wsec2
« 0,85 cp (Reference 1,
(0.15 x 0.071 x 62.18 x 32.2)
1(0.85)
0.56 Jb/sec-ft* (at Hooding)
Assuming f» 0,60
GW(t » 0,60x0.56*0.34
Thus,
A
**
-a.7,-4 a
4.7.3.3 Column Height and Removal Efficiency
The column must be of sufficient height to ensure that
the required removal efficiency is achieved. The height
of a packed column is calculated by determining the
required number of theoretical transfer units and multi-
plying by the height of a transfer unit. A transfer unit is a
measure of the difficulty of the mass transfer operation
and is a function of the solubility and concentrations of
the solute in the gas and liquid streams. It is expressed
as N^or N0, depending on whether the gas film or liquid
film resistance controls the absorption rate. In emission
control applications, gas film resistance will typically be
controlling, therefore N^ will be used in the following
calculations.
The expression for the column height (packed) is:
Ht =N H (4.7-12)
where:
HI
N
column
'ofl
H.
°9
packed column height, ft
number of gas transfer units (based on
overall gas film coefficients)
height of an overall gas transfer unit
(based on overall gas film coefficients), ft
Although the determination of NM is usually compli-
cated, when dilute solutions are involved, N^ can be
calculated using the following equation;
Nog =
r(HAPe/HAP0)(1--L;
In I _-AF__
AF
(4.7-13)
__
AF
This expression is simplified based on the assumption
that no HAP is present in the solvent as it enters the
column (see Reference 8 for details). Alternatively, use
Figure 4.7-3 directly to determine N^.9 Equation 4.7-13
is the basic design equation for absorber system effi-
ciency. It relates the inlet and desired outlet concentra-
tion to the number of transfer units (N ) through the
absorption factor, AF, discussed eariierin Section4,7.3.1.
The usermustcalculatethedesired outlet concentration
HAP0, from the inlet concentration HAPe, and the re-
quired removal efficiency, RE, using the expression:
= HAPe(1-RB100)
(4.7-14)
The outlet concentration (HAP0) is then input Into equa-
tion 4.7-13 and the corresponding column height is
obtained. In general, a larger value for N will yield a
greater removal efficiency, until the driving force of the
two streams are roughly equal, and HAP transfer from
the gas stream to the liquid (or vice versa) ceases. At
this point, for all practical purposes no further transfer
occurs.
4-48
-------
Once the number of transfer units (N ) is known, the
height of each transfer unit (H)must be calculated. The
variable H^ can be calculated from the following equa-
tion:
(4.7-15)
where:
height of a gas transfer unit, ft
height of a liquid transfer unit, ft
Generalized correlations are available to calculate HQ
and HL; these are based on the type of packing and the
gas and solvent flow rates. The correlations for HG and
HL are as follows:4
HG . [b (3,600
\0,5
HL = Y(L7nL"KScL)°
where:
0.5
(4.7-16)
(4.7-17)
b, c, d, Y, and s = empirical packing constants
(see Tables C.7-1, C.7-2 or
Reference 1) .
L" = liquid flow rate, Ib/hr-ft*
\iL" = liquid viscosity, Ib/ft-hr
Sca= Schmidt number for the gas stream (Table
C.7-3)
Sc. = Schmidt number for the liquid stream (Table
C.7-4)
Other values of ScQ and Sc, for several compounds are
listed in References 3 and"4.,In the calculations, it is
assumed that the effect of temperature on Sc is negli-
gible. The value for the variable L" in this equation is
calculated as follows:
L" = L/A.
column
(4.7-18)
Use the following expression to calculate the total col-
umn height (Ht, J once the variable Ht^,^ has been
obtained throuqh use of Equation 4.7-12"?
0.250
^
(4.7-19)
To determine packing costs, the volume occupied by the
packing material (V,) has to be calculated.
Use the following expressions:
0.785
column
nt
column
(4.7-20)
4-49
-------
Table 4.7-1. Comparison of Calculated Values and Values Sup-
plied by the Permit Applicant for Absorption
Table 4.7-2. Cost of Packing Materials*
Calculated
Value Reported
Parameter (Example Case)" Value
Solvent ftow rate, L^ 35gal/mln
Column diameter, D^.^ 4 ft
Column height, Ht^^ 23 ft
Total column height, H^ 26 ft
Packing volume, Vp^,^ 290 ft3
Pressure drop, P,^ 12 In. H2O
« Based on Emission Slream 5,
Example Case
Using Equation 4.7-20; ' " ,. :
HUimn * 23 tt
Vtti = 0.785 x{4f* S3-
CS, ^^ft5 ^_ -
4.7.3.4 Pressure Drop through the Column
The pressure drop through a packed column or any
combination of liquid and gas flows in the operable range
is an important economic consideration in the design of
Figure 4.7-4. Costs of absorber towers.
20 —
** _—— •"""""
•°r 10 "" .^~<~~~~~*^^*'
1 8= ~^^^~^^^
4 p**"***""^
|
Packing Type and
Material Cost per ft3
Packing Diameter, in. 1 1 .5 2 3
Flexisaddles
Porcelain 19.50 17.75 16.75 16.00
Polypropylene 20.00 18.00 - -
Stoneware 19.50 17.75 16.75 16.00
Raschiq Rings
Porcelain 16.00 14.50 12.75 13.25
Pall Rings
Carbon Steel 35.00 30.00
304L Stainless Steel 73.50 69.80 66.00
31 6L Stainless Steel 103.00 101.00 97.00
• Reference 8.
such columns. For a particular packing, the most accu-
rate data will be those available from the manufacturer.
For purposes of estimation, use the following correla-
tion:4
Pa = (g x 1 0-8) [1 0!tCTL>] (3,600 GmJ2/0Q (4.7-21 )
where:
Pa = pressure drop, Ib/ft2-ft
g, r = packing constants (see Appendix C.7 or
Reference 4)
The total pressure drop through the column is then
expressed as:
P,0,a,= PaXHtCOIumn (4.7-22)
I III
June 1988
*2£zZ^7
_^-^^o^eed
^^^
I I t I
10 20 30 40 50 60 70
Column dia,, in.
4-50
-------
Table 4.7-3. Capital Cost Factors for Absorbers*
Cost Item
Factor
Direct Costs, DC
Purchased equipment cost
Absorber (tower & packing) + auxiliary equipment
Instrumentation
Sales tax
Freight
Purchased Equipment Cost, PEC
Direct Installation Costs
Foundation and supports
Erection and handling
Electrical
Piping
Insulation
Painting
Direct Installation Cost
Site preparation
Building
Total Direct Costs, DC
Indirect Costs. 1C
Engineering
Construction
Contractor fee
Start-up
Performance test
Contingencies
Total Indirect Cost
Total Capital Costs
As estimated, EC
0.10 EC
0.03 EC
- - 0.05 EC
1.18 EC
0.12 PEC
0.40 PEC
0.01 PEC
0.30 PEC
0.01 PEC
0.01 PEC
0.85 PEC
.As required, SP
As required. Bldg.
1.85 PEC +SP + Bldg,
0.10 PEC
0.1 OPEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.35 PEC
2.20 PEC + SP + Bldg.
"Reference 9.
4.7.4 Evaluation of Permit Application
Compare the results from the calculations and the
values supplied by the permit applicant using Table 4.7-
1. The calculated values in the table are based on the
example case. If the calculated values of L^, D^, ,
HW'JHW piota.'Jand V^^are diltarent'Tbm the
reported values for these variables, the differences may
be due to the assumptions involved in the calculations.
Therefore, the reviewer may wish to discuss the details
of the proposed design with the permit applicant.
4-51
-------
Table 4.7-4. Example Case Capital Costs
Cost Item
Factor
Cost
Direct Costs, PC
Purchased equipment cost
Absorber (tower & packing)
+ auxiliary equipment
Instrumentation
Sales tax
Freight
Purchased Equipment Cost, PEC
Direct Installation Costs
Foundation and supports
Erection and handling
Electrical
Piping
Insulation
Painting
Direct Installation Cost
Site preparation
Building
Total Direct Costs, DC
Indirect Costs. 1C
Engineering
Construction
Contractor fee
Start-up
Performance test
Contingencies
Total Indirect Cost
Total Capital Costs
As estimated, EC
0.10 EC
0.03 EC
0.05 EC
1.18 EC
0.12 PEC
0.40 PEC
0.01 PEC
0.30 PEC
0.01 PEC
0.01 PEC
0.85 PEC
As required, SP
As required, Bldg.
1.85 PEC + SP + Bldg.
0.10 PEC
0.10 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.35 PEC
2,20 PEC+SP +Bldg.
$38,700
3,870
1,160
1.940
$45,670
$5,480
18,300
457
13,700
457
457
$38,900
$84,500 + SP + Bldg.
$ 4,570
4,570
4,570
457
457
1.370
$16,000
.$100,000 + SP •»• Bldg.
If the calculated values agree w'rth the reported values,
then the design and operation of the proposed scrubber
system may be considered appropriate based on the
assumptions made in this handbook.
4.7.5 Capital and Annual Costs of Absorbers
The capital cost of an absorber system consists of the
purchased equipment cost an direct and indirect instal-
lation costs. The annual cost consists of direct and
indirect annual costs.
4.7.5.1 Capital Costs for Absorbers
The capital cost of an absorber system is composed of
purchased equipment costs and direct and indirect
Installation costs. The purchased equipment cost con-
sists of the equipment cost, which includes the cost of a
tower, packings, auxiliary equipment, instrumentation,
freight, and taxes.
Rgure 4.7-4 provides the cost in June 1988 dollars of
absorber towers as a function of column diameter.
These costs were obtained from Reference 7. The cost
of various packing materials is given in Table 4.7-2 and
was obtained from Reference 8. The cost of auxiliary
equipment (e.g., ductwork and fan) may be obtained
from Section 4.12. The auxiliary equipment cost, plus
the cost of the adsorber tower and packing is the
equipment cost, EC. Table 4.7-3 provides the cost
factors necessary to estimate the purchased equipment
cost as well as the direct and indirect installation cost
factors.
4-52
-------
l^lllliils^lliliiill
4.7.5.2 Annual Costs for Absorbers
The annual cost for an absorber system consist of direct
and indirect annual costs. For purposes of this manual
recovery credits for absorber systems are assumed to
equal zero. While an absorber does "recover" HAPs by
transferring them to a liquid stream, further separation
equipment is usually necessary to obtain the pure HAP.
Therefore, recovery credits are assumed zero.
Table 4.7-5 provides the appropriate cost factors to
estimate annual costs.
Direct Annual Costs. Direct annual costs consist of
utilities (electricity, solvent) and operating labor and
maintenance costs.
The electricity usage is a function of the fan power
requirement. Equation 4.7-23 is used to estimate this
value. The annual usage is then multiplied by the elec-
tricity cost (Table 4.7-5) to obtain the electricity cost.
p
where:
P.
Ciea
1.81 x 10* (QJ(P«J(HRS) (4.7-23)
= fan power requirement, kWh/yr
= actual emission stream flow rate, acfm
= system pressure drop, in. H2O
HRS = systemoperatinghoursperyear.hr/yr
To obtain Q8a from Qe, use the following formula:
Qe.. = .Q.(T. + 460)/S37'
The annual electricity cost ( AEC) is then :
Annual Electricity Cost = $ 0.059 (Fp )
To obtain the cost of solvent (usually water) use Equa-
tion 4.7-24 to estimate the annual consumption of sol-
vent:
where:
ASR = annual solvent requirement, gal/yr
This value is then multiplied by the solvent cost provided
in Table 4.7-5 to obtain annual costs.
Annual Solvent Costs: $0.20/1,000 gal x (ASR)
The amount of operator labor is estimated as 0.5 hours
perS hour shift. The operator labor wage rate is provided
in Table 4.7-5. Supervisory costs are assumed to be 15
percent of labor costs.
The amount of maintenance labor is estimated as 0.5
hours per 8 hour shift. The maintenance wage rate is
provided in Table 4.7-5. Maintenance material costs are
assumed to equal 100 percent of maintenance labor
costs.
Indirect Annual Costs.Jhese costs consist of overhead,
property tax, insurance, administrative, and capital re-
covery costs. Appropriate cost factors to estimate the
indirect annual costs are given in Table 4.7-5.
ASR . 60 (LA HRS
(4.7-24)
4-53
-------
Exam
375
Property taxe^i ==,
Capital recovery"
Total Indirect Costs
Total Annual Costs »
Total Di
Indirect Annual Costs
These costs are.oblalnMfjp]r|i|^|p|§^|^||||
Table 4,7-i
Overhead
Administrative
Insurance
-;"t•.'-'"•' '••"-;;-;';'":•:•.-••-•,-,':••••';';•;•;•;•;•;-•;•;•-:';';•>:•:•;•:•:':•---
Tabls 4.7-5 Annual Cost Factors for Absorber Systems*
Cost Item
Factor
Direct Cost. DAC
Utilities
Electricity
Solvent (water)
Operating Labor
Operator labor
Supervisor
Maintenance
Maintenance labor
Materials
Indirect Costs, IAC
Overhead
Administrative
Property taxes
Insurance
Capital recovery1'
$0.059/kWh
$0.20/10* gal
$12.86/hr
15% of operator labor
$14.96/hr
100% of maintenance labor
0.60 (Operating labor &
maintenance)
2% of TOO
1%ofTCC
1%ofTCC
0.1628 (TCC)
• Reference: 9,12.
'Capital recovery factor Is estimated as: i(1+i}"/(1-H)"-1
where: 1 = interest rate, 10
percent
n = equipment life, 10
years
4.7.6 References
1. Chemical Engineer's Handbook. Perry, R.H,, and
Chilton, C.H., eds. Sixth Edition. McGraw-Hill Book
Company. New York. 1980.
2. Treybal, R.E. Mass Transfer Operations. Third Edi-
tion, McGraw-Hill Book Company. New York. 1980.
3. U.S. EPA. Wet Scrubber System Study, Volume 1:
Scrubber Handbook. EPA-R2-72-118a (NTIS PB
213016). August 1972.
4. U.S. EPA. Organic Chemical Manufacturing. Vol-
ume 5: Adsorption, Condensation, and Absorption
Devices. EPA-450/3-80-027(NTIS PB81-220543).
RTP, NC. December 1980.
5. Vatavuk, W.M. and R.B. Neveril. Part XIII. Costs of
Gas Adsorbers. Chemical Engineering. October 4,
1982.
6. Kohl, A. and F. Riesenfield. Gas Purification. Sec-
ond Edition. Guif Publishing Co., Houston, TX.
1974.
7. Hall, R.S., Vatavuk, W.M. and J. Matiey. Estimating
Process Equipment Costs. Chemical Engineering.
November 21,1988.
8. Tetecons. Sink, M.K. to Koch Engineering Co. and
Glitsch, Inc. Costs of Tower Packings. PES, Inc.,
RTP, NC. January 1990.
9. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. EPA 625/6-86-014. (NTIS
PB91-228809). Cincinnati, OH. September 1986.
10. Chemical Engineering Reference Manual. Fourth
Edition. R.E. Robinson. Professional Publications,
Belmont, CA. 1987.
11. Buonicore, A. J. and L. Theodore. Industrial Control
Equipment for Gaseous Pollutants. Volume I. CRC
Press, Inc. Cleveland, OH. 1975.
12. U.S. EPA OAQPS Control Cost Manual. Fourth
Edition. EPA 450/3-90-006 (NTIS PB 90-169954).
RTP, NC. January 1990.
13. Modern Pollution Control Technology. Volume I: Air
Pollution Control. M. Fogiel, ed., Research and
Education Association, New York, NY. 1978.
14. R.F. Shringle. Random Packings and PackedTow-
ers. Gulf Publishing Company, Houston, TX. 1987.
4-54
-------
Condensers
Condensation is a separation technique in which one or
more volatile components of a vapor mixture are sepa-
rated from the remaining vapors through saturation
followed by a phase change (see Figure 4.8-1). The
phase change from gas to liquid can be accomplished in
two ways: (a) the system pressure may be increased at
a given temperature, or (b) the system temperature may
be reduced at constant pressure.
The design and operation of a condenser are affected
significantly by the number and nature of the compo-
nents present in the emission stream. For example,
condenser efficiency is very sensitive to the HAP inlet
concentration. In a two-component vapor system where
one of the components is noncondensible (e.g., air),
condensation occurs at dew point (saturation) when the
partial pressure of the condensible compound (e.g.,
benzene) is equal to its vapor pressure. In most HAP
control applications, the emission stream will contain
large quantities of noncondensible and small quantities
of condensible compounds. To separate the condensible
component from the gas stream at a fixed pressure, the
temperature of the gas stream must be reduced. The
more volatile a compound (i.e., the lower the normal
boiling point), the larger the amount that can remain as
vapor at a given temperature; hence the lower the
temperature required for saturation (condensation).
When condensers are used to control emissions, they
are usually operated at the pressure of the emission
source, which is typically close to atmospheric. Depend-
ing on the temperatures required for condensation, a
refrigeration unit may be necessary to supply the coolant
(see Section 4.8.3.1). The two most common types of
condensers used are surface and contact condensers.
Surface condensers are usually shell-and-tube heat
exchangers. The coolant typically flows through the
tubes and the vapors condense on the shell outside the
tubes. The condensed vapors forms a film on the cool
tubes and are drained to a collection tank for storage or
disposal. In contrast to surface condensers where the
coolant does not contact either the vapors or the con-
Emission Stream Outlet
Emission
Stream
lnlet - ' ' •- Condensed
VOC
Condenser
Cools
hi
1
ant
I
Tcoof.1
Refrigeration
Unit
densate, in contact condensers, the vapor mixture is
cooled by spraying a cool liquid directly into the gas
stream.
Proper maintenance of a condenser system is an impor-
tant aspect to maintain performance. Over time, scale
buildup will tend to foul condenser systems. Symptoms
of this include a significant increase in fluid pressure
drop, or a decrease in heat transfer resulting in an
increase in fluid outlet temperature and a decrease in
efficiency. For adequate control of HAPs, the emission
stream outlet temperature must be continuously moni-
tored. It is important to perform this cleaning without
delay, because scale buildup becomes much harder to
remove over time.1-11
Design calculations for condenser systems vary in com-
plexity depending on the nature and number of compo-
nents present in the emission stream. For detailed
information on condenserdesign, consult References 1,
2, and 3. In the following discussion, Emission Stream 6,
consisting of a single condensible component and a
single noncondensible component, will be used to illus-
trate the calculation procedure for surface condensers.
The moisture content of the emission stream is assumed
to be negligible (i.e., no ice is expected to form on the
tubes in the condenser). The design procedure will
involve determining the condensation temperature re-
quired, selection of coolant, and calculation of con-
denser size and coolant requirements.
4.8.1 Data Required
The data necessary to perform the calculations consist
of HAP emission stream characteristics previously com-
piled on the HAP Emission Stream Data Form and the
required HAP control as determined by the applicable
regulations.
Figure 4.8-1
Flow diagram for typical refrigerated con-
denser system.
In the case of a permit review for a condenser, the
following data should be supplied by the applicant. The
calculations in this section will then be used to check the
applicant's values. Worksheets for calculations are pro-
vided in Appendix C.8.
4-55
-------
Condenser system variables at standard conditions
(77°F, 1 atm):
Reported removal efficiency, REreport8d,%
Emission stream flow rate, Q9, scfm
Temperature of emission stream, Te, °F
Specific HAP
HAP concentration, HAP«, ppmv
Moisture content, M.,%
Temperature of condensation, Toon, °F
Coolant used
Inlet temperature of coolant, T^u, °F
Coolant flow rate, Q«>oiam, Ib/hr
Refrigeration capacity, Ref, tons
Condenser surface area, A*,,,, ft2
Specific heat of HAP, CpHAP, Btu/lb-moi °F
Heat of vaporization of HAP, AH, Btu/lb-mol
(Note: Heat capacities for over 700 compounds are
provided in Reference 10.)
4.8.2 Pretreatment of the Emission Stream
If water vapor is present in the emission stream, ice may
form on the condenser tubes when coolants such as
chilled water or brine solutions are used, decreasing the
heattransfer efficiency andthus lowering thecondenser's
removal efficiency. In such cases, dehumidifying the
emission stream is necessary. This can be carried out in
a heat exchanger prior to the condenser, which cools the
vapor down to about 35°F. However, even with pretreat-
ment (e.g. heat exchanger), water vapor can remain a
problemfor sub-zero systems, and adequate provisions
should be integrated into the system. Such provisions
can include a dual condenser system where a heated air
stream is passed through the condenser that is down,12
4.8.3 Condenser System Design Variables
The key design variable in condenser system design is
the required condensation temperature for a given re-
moval efficiency or outlet concentration. A condenser's
removal efficiency greatly depends on the concentration
and nature of emission stream components. For ex-
ample, compounds with high boiling points (i.e., low
volatility) condense more readily compared to those with
fow boiling points. Assume, as a conservative starting
point, that condensation will be considered as a HAP
emission control technique for VOCs with boiling points
above 100°F.
The temperature necessary to achieve a given removal
efficiency (or outlet concentration) depends on the vapor
pressure of the HAP in question at the vapor/liquid
equilibrium. Once the removal efficiency fora given HAP
is specified, the required temperature for condensation
can be determined from data on its vapor pressure-
temperature relationship. Vapor pressure-temperature
data can be represented graphically (Cox charts) as
shown in Figure 4.8-2 for typical VOCs. The coolant
selection is then based on the condensation tempera-
ture required. SeeTable4.8-1 forasummary of practical
limits for coolant selection.
In a permit evaluation, use Table 4.8-1 to determine if the
values reported for the condensation temperature (Toon)
and the type of coolant selected are consistent. Also,
check if the coolant inlet temperature is based on a
reasonable approach temperature (a conservative value
of 15°F is used in the table). If the reported values are
appropriate, proceed with the calculations. The permit
reviewer may then follow the calculation procedure
outlined below. Otherwise, the applicant's design is
considered unacceptable unless supporting documen-
tation indicates the design is feasible.
The condenser system evaluated in this handbook con-
sists of a shell-and-tube heat exchanger with the hot fluid
(emission stream) in the shell side and the cold fluid
(coolant) in the tube side. Depending on the application,
the tube side and shell side fluids may be reversed. The
emission stream is assumed to consist of a two-compo-
nent mixture: one condensible component (HAP) and
one noncondensible component (air). Typically, con-
densation for such a system occurs nonisothermally. To
Table 4.8-1. Coolant Selection*
Required
Condensation
Temperature
Coolant
Temperature
Coolant
Tea,:"160-80
60 > T,» > 45
45 > T«, 2 -30
-30 TO,, a -90
Water
Chilled water
Brine solutions
(e.g., calcium
chloride, ethy-
lene glycol)
Chlorofluorocar-
bons (e.g.,
Freon-12)
T^-15
T^-15
" Reference 4.
b Also emission steam outlet temperature.
5 Assume the approach as 15°F.
* Summer limit
simplify the calculations, it is assumed that condensa-
tion occurs isothermally. This assumption usually does
not introduce large errors into the calculations.
4.8.3.1 Estimating Condensation Temperature
In the following calculations, it is assumed that the
emission stream entering the condenser consists of air
saturated with the HAP in question. Calculations for
cases involving mixtures of HAPs and supersaturated
streams are quite complex and will not be treated here
since they are beyond the scope of this handbook.
References 5 and 6 may be consulted for information on
these streams.
For a given removal efficiency, the first step in the
calculation procedure is to determine the concentration
at the outlet of the condenser. Use the following expres-
sion:
= 760 {(1 - 0.01 RE)/[(1 - (RE x 10-8
x HAP,)]} HAP. x 10-6 (4.8-1)
4-56
-------
Q.
0.1
0.00125 ' 0.00175 ' 0.00225 < 0.00275
0.00150 . 0.00200 0.00250 0.00300
Figure 4.8-2 Vapor pressure-temperature relationship.
the partial pressure (mm Hg) of the HAP in the
exit stream assuming the pressure in the condenser is
constant and at atmospheric. At equilibrium between the
gas and liquid phases, the partial pressure of the HAP is
. equal to its vapor pressure at that temperature. There-
fore, by determining the temperature at which this con-
dition occurs, the condensation temperature (T^n) can
be specified. To carry out this calculation, vapor pres-
sure-temperature data forthe specific HAP are required
(see Figure 4.8-2). Such data can be obtained from
References 3 and 7.
The partial pressure can be calculated as a function of
the desired removal efficiency using Equation 4.8-1.
This equation is valid for the range of removal efficien-
cies likely to be encountered. However, note that the
partial pressure necessary to obtain a high removal
efficiency may result in a condensation temperature
(T«n) that is not realistically obtainable. In this case, a
lower removal efficiency must be accepted, or adifferent
control technique is warranted. Information on coolants
necessary for a given condensation temperature and
whether T^ is obtainable realistically are provided in
Table 4.8-1.
*:*:'Wv:l^f?^K->:-:':*:v:*;*:^^
4.8.3.2 Selecting the Coolant
The next step is to select the coolant based on the
condensation temperature required. Use Table 4.8-1 to
specify the type of coolant. For additional information on
coolants and their properties, see References 3 and 7,
• vX'TTXv^.-.wT;' =7v' •"•"• •.v.www'Kv;1 /KVI-TX-KV ^<-:v~---^^~s•.c^tvaF.v.^T;•I^.v;c•7^•~•~<•^~•^~•?7;•,•,v"'^'-T•~' ^^v.v^".v.•^:
iii^SSxSiimaSiSSi:::^^
4.8.3.3 Condenser Heat Load
Condenser heat load is defined as the quantity of heat
that must be extracted from the emission stream to
achieve a certain level of removal. It is determined from
an energy balance, taking into account the heat of
condensation of the HAP, sensible heat change of the
HAP, and the sensible heat change in the emission
stream. This calculation neglects enthalpy changes
associated with non-condensible vapors (i.e., air), which
is typically a very small value. The calculation steps are
outlined below:
la. Calculate moles of HAP in the inlet emission
stream (Basis: 1 min):
HAPe.m = (CX/392) HAP8 x 10"6
(4.8-2)
The factor 392 is the volume (ft3) occupied by 1
Ib-moleof ideal gas at standard conditions (77°F
and 1 atrn).
1 b. Calculate moles of HAP remaining in the outlet
emission stream (Basis: 1 min):
HAPom = (Q9/392)[1 - (HAPe x
(4.8'3)
where Pvapor is equal to Ppaifiugiven in Equation 4.8.1 .
1c. Calculate moles of HAP condensed (Basis:
1 min):
4-57
-------
HAPcoo=HAPw-HAP0,rn
(4.8-4)
2a. DetermJnethe HAP'sheatof vaporization (AH):
Typically the heat of vaporization will vary with
temperature. Using vapor pressure-tempera-
ture data as shown in Figure 4.8-2, A H can be
estimated by linear regression for the vapor
pressure and temperature range of interest (see
Reference 3 for details). Compare this value
with that of the permit application, taking care to
ensure both are in the same units. If these
values differ significantly, contact the permit
applicant to determine the reason for the differ-
ence.
2b. Calculate the enthalpy change associated with
the condensed HAP (Basis: 1 min):
on [A H
(T9 -
(4.8-5)
Where CPHAP is the average specific heat of the
HAP forthetemperature interval Jmn- T8 (Btu/Ib-
mole-°F) (See Table C.8-1 ).
2c. Calculate the enthalpy change associated with
the noncondensibte vapors (i.e., air) (Basis: 1
min):
(4.8-6)
Cp,ir(T8-TMr,)
where Cp^r is the average specific heat of air for
the temperature interval TMn - Te (Btu/Ib-mole-
°F) (See Table C.8-1).
3a. Calculate the condenser heat load (Btu/hr) by
combining Equations 4.8-5, and 4.8-6:
HbK)» 1.1 x 60 (H..,, + H^,,) (4.8-7)
The factor 1.1 is included as a safety factor.
,. ..,*-- -• -. ~- v~;~'.: .< ,•>:*:•;•:•;•!•;•!«;.;•;•.'.'.•;-: >:•:';•:•:•:•;•:•:-:•:•:•:•:•:•:•:•:•;•:•: :•:•;•.•.•.•;,•
HAP,
1C. HAP™,
2a. AH
4.8.3.4 Condenser Size
Condenser systems are typically sized based on the
total heat load and the overall heat transfer coefficient
estimated from individual heat transfer coefficients of
the gas stream and the coolant. An accurate estimate of
individual coefficients can be made using physical/
chemical property data for the gas stream, the coolant,
and the specific shell-and-tube system to be used. Since
calculation of individual heat transfer coefficients is
beyond the scope of this manual, the value used in this
manual for the overall heat transfer coefficient is a
conservative estimate. This approach will tend to yield a
conservatively large surface area estimate. For addi-
tional information on how to calculate individual heat
transfer coefficients, consult References 1,2, and 3. This
calculation procedure assumes counter current flow,
which is commonly found in industrial applications.
However, some applications may employ co-current
flow, or use fixed heat exchangers. The procedure
below is still valid for co-current flow, but an adjustment
must be made to the logarithmic mean temperature
difference as discussed below.8
To size condensers, use the following equation to deter-
mine the required heat transfer area:
Aeon =
where:
U
and:
where:
' U ATtw (4.8-9)
condenser (heat exchanger)
surface area, ft2
= overall heat transfer coefficient,
Btu/hr-fP-T
= logarithmic mean temperature
difference, °F
(T» - Toool,o) • (Toon - Toool, l)
In [(Te -Toooi,o)/(Toon - Toool, l)]
emission stream temperature, °F
4-58
-------
•cool.o
'con
coolant outlet temperature, °F
condensation temperature, °F
coolant inlet temperature, °F
Note: For co-current flow, this equation becomes:
. _ (T« - Toool, l) - (Toon - Toool, o)
AlLM ~
In [(T8 -
-TCOQI.O)]
Assume that the approach temperature at the con-
denser exit is 15°F. In other words, T^y = (!„„ -15).
Also, the temperature rise of the coolant fluid is specified
as 25°F, i.e., T&x,^ = (T^o + 25) where T^o is the
coolant exit temperature. In estimating Aa*,, the overall
heat transfer coefficient can be conservatively assumed
as 20 Btu/hr-ftz-°F; the actual value will depend on the
specific system under consideration. This calculation is
based on References 2 and 6 in which guidelines on
typical overall heat transfer coefficients for condensing
vapor-liquid media are reported.
4.8.3.5 Coolant Flow Rate
The quantity of heat extracted from the emission stream
is transferred to the coolant. By a simple energy balance,
the flow rate of the coolant can be calculated as follows:
~ Tcoo!,i)]
(4.8-10)
, Qeoota* =
where:
Qcoolar*
Cpcootant
Specific heat data for coolants are available in Refer-
ences 3 and 7.
coolant flow rate, Ib/hr
average specific heat of the
coolant over the temperature
interval TeooutoT,,,,,,^, Btu/lb-°F
4.8.3.6 Refrigeration Capacity
A refrigeration unit is assumed to supply the coolant at
the required temperature to the condenser. For costing
purposes, the required refrigeration capacity is expressed
in terms of refrigeration tons as follows:
Ref = H^/12,000 (4.8-11)
where Ref is the refrigeration capacity, tons.
4.8.3.7 Recovered Product
To calculate costs, the quantity of recovered product
that can be sold and/or recycled to the process must be
determined. Use the following equation:
Qw = 60 x HAPoon x MWHAP (4.8-12)
where Qteo is the quantity of product recovered, Ib/hr.
4.8.4 Evaluation of Permit Application
Compare the results from the calculations and the
values supplied by the permit applicant using Table 4.8-
2. The calculated values in the table are based on the
Example Case. If the calculated values of Jmn, coolant
type, A-on, Qwoiant, Ref, and Qae are different from the
reported values for these variables, the differences may
be due to the assumptions involved in the calculations.
Therefore, the reviewer may wish to discuss the details
of the proposed design with the permit applicant. If the
calculated values agree with the reported values, then
the design and operation of the proposed condenser
system may be considered appropriate based on the
assumptions made in this handbook.
4.8.5 Capital and Annual Costs of Condensers
The capital costs of a condenser system consists of
purchased equipment costs and direct and indirect
installation costs. Annual costs consist of direct and
indirect annual costs.
4.8.5.1 Capital Costs for Condensers
The capital cost of a condenser system is composed of
purchased equipment costs (equipment costs and aux-
iliary equipment), and direct and indirect installation
4-59
-------
costs. Factors for these costs are presented in Table
4.8-3. Equipment costs for cold-water condenser sys-
tems were obtained from References 4 and 8. Equip-
ment costs for fixed tubesheet and floating head heat
exchangers are given in Figures 4.8-3 and 4,8-4 for heat
transfer surface areas (/Cn) from 300-1,500 ft2. The
equipment costs are in July 1988 dollars. The cost of
auxiliary equipment can be obtained from Section 4.12
and includes ductwork, dampers, fan and stack costs.
Tabl« 4.8-2. Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Condensa-
tion
Calculated
Value Reported
(Example Case}* Value
Continuous monitoring of
exit stream
temperature
Condensation
temperature.To,,,
yes
20°F
Coolant type
Coolant flow rate,
Condenser surface
area, A*,,
Refrigeration
capacity, Ref
Recovered product, Q*,
Brine Solution
14,700 Ib/hr
370 ft2
20 tons
373 Ib/hr
'Based on Emission Stream 6.
For condenser systems requiring a coolant based on
Table 4.8-1, Table 4.8-4 can be used to estimate the
total capital cost (TCC) of a refrigerant system, as a
function of refrigeration capacity (Ref) and condensa-
tion temperature (T^). This cost must be added to the
condenser capital cost (TCC) obtained from Rgures 4.8-
3 or 4.8-4 and Table 4.8-3. Although refrigerated units
are often sold as packaged systems, splitting the cost of
the basic condenser system and refrigerant system in
this manner allows for more flexibility in estimating the
cost of a given system. A refrigerant system may not be
necessary for required condensatfontemperaturesabove
40°F, depending on the cooling water available.
The costs given in Table 4.8-4 are in spring 1990 dollars
and were obtained from Reference 13. Table, 4.8-5
provides the Example Case capital costs for the con-
denser systems.
Table 4.8-3. Capital Cost Factors for Condensers*
Cost Item Factor
Direct Costs
Purchased Equipment Costs
Condenser & auxiliary equipment As estimated, EC
Instrumentation13 0.10 EC
Sales tax 0.03 EC
Freight 0.05 EC
Purchased Equipment Cost, PEC 1.08 EC
Direct Installation Costs
Foundation and supports 0.08 PEC
Erection and handling 0.14 PEC
Electrical 0.08 PEC
Piping 0.02 PEC
Insulation 0.10 PEC
Painting 0.01PEC
Direct Installation Cost 0.43 PEC
Site preparation As required, SP
Buildings As required, Bidg.
Total Direct Costs, DC
Indirect Installation Costs
Engineering
Construction
Contractor fee
Start-up
Performance test
Contingencies
Total Indirect Cost,IC
Total Capital Costs'
1.43 PEC+SP+Bldg.
0.10 PEC
0.05 PEC
0.10 PEC
0.02 PEC
0.01 PEC
0.03 PEC
1.31 PEC
• References 4,9.
* Typically included with the condenser cost.
c Does not include cost of refrigeration system.
fSffSO&Xfft&ft-ZZfllfifiifflffi^SSS;
4-60
-------
30
20
8
O '
O 10
6
200
July 1988
400
600
800 1,000
Heat Transfer Surface, ft8
1,200
1,400
1,600-
Figure 4.8-3. Costs for fixed tubesheet condensers.8
40
30
20
d
10
8
200
July 1988
I
1
400
600 800 1,000 1,200
HeatTransferSurface.lt2
1,400
1,600
1,800
Figure 4.8-4. Costs for floating head condensers.8
4-61
-------
. . •• " ^X'Eiaimjj^lliplC^llli? .._,,,..,„_
Oncethptotal oapttai c^:i(|i»|||:||:i;j^ni||^|r:|p
obtained, the'^jK^c^^l^^f^^^^*^^^^
tern oiu$t t)d added |<^|he :Tv0l--81
this example'" - ^^^ •***»****
ref ligeratiori capacl^ '|i:;||||^|||i||i||^3|il
cost of the :^n^&n^'':^^^^i^sis^^ai^:iff;:
Table 4,8-5.
Tabla 4.8-4. Capital Coals for Refrigerant Systems'*
Required Condensation
Temperature, °F
Refrigerant System
Capital Cost, RTCC $
&-20°F
5£-45"F
RTCC - 1,989.6 (Ref) + 10,671
RTCC m 4,977 (Ref) + 7,615
RTCC - 7,876.8 (Ref) + 9,859
RTCC = 6,145.4 (Ref) + 26,722
RTCC - 10,652 (Ref) + 13,485
RTCC -12,489 (Ref) + 28,993
• Reference 13
k See Equation 4.8-11 for a definition of Ref.
" A refrigerant system may be required for condensation tempera-
tures between 40-60°F, although this will be dependent on the
cooling water available. If cooling water of a sufficiently low tem-
perature is available, a refrigerant system is not required.
4.8.5.2 Annual Costs for Condensers
The annual costs for a condenser system consists of
direct and indirect annual costs minus recovery credits.
Table 4.8-6 provides appropriate factors for estimating
annual costs.
Direct Annual Costs. Direct annual costs consist of
utilities (electricity, refrigerant) and operating labor and
maintenance costs.
The electricity cost is a function of the fan power require-
ment. Equation 4.8-13 can be used to obtain this require-
ment, assuming afan-motor efficiency of 65 percent and
a fluid specific gravity of 1.0.
Fp =1.81x10-4(QM)(P)(HRS) (4.8-13)
where:
Fp * fan power requirement, kWh/yr
QM « emission stream flow rate, acfm
P » system pressure drop, in. H2O (default
- 5 in. H2O)
HRS « system operating hours per year, hr/yr
To obtain Qe.« from Qe, use the following formula
Q... - Q4(Te-f- 460)7537
The cost of refrigerant replacement will vary with each
condenser system, but typically is very low. Therefore,
assume refrigerant replacement costs are zero unless
specific information is available.
The amount of operator labor is estimated as 0.5 hours
per 8 hour shift. The operator labor wage rate is given in
Table 4.8-6. Supervisory costs are assumed to be 15
percent of operator labor cost. The amount of mainte-
nance labor is estimated as 0.5 hours per 8 hour shift.
The maintenance wage rate is provided in Table 4.8-6.
Maintenance costs are estimated as 100 percent of
maintenance labor costs.
Indirect Annual Costs. Thesecosts consist of overhead,
property tax, insurance, administrative, and capital re-
covery costs. Table 4.8-6 provides the appropriate cost
factors.
Recovery Credits. Recovery credits for a condenser
system may be significant. The amount of HAP recov-
ered can be estimated using Equation 4.8-12, given in
Section 4.9.3.7. The recovery credits are then obtained
by multiplying the value of the recovered product by the
amount of recovered product.
IMispralilh^
tBi-«M^^^
4-62
-------
Table 4.8-5.
Cost Item
Example Case Capital Costs
Factor
Cost($)
Direct Costs
Purchased Equipment Costs
Condenser & auxiliary equipment
instrumentation
Sales tax
Freight
Purchased Equipment Cost, PEC
As estimated, EC
0.10 EC
0.03 EC
0.05 EC
1.08 EC
$ 18,500
Included
55S
925
20,000
Direct Installation'Costs
Foundation and supports
Erection and handling
Electrical
Piping
Insulation
Painting
Site preparation
Buildings , ,
Total Direct Cost, DC
Indirect Installation Cost
Engineering
Construction
Contractor Fee
Start-up
Performance test
Contingencies
Total Indirect Cost, 1C
0.08 PEC
0.14 PEC
0.08 PEC
0.02 PEC
0.10 PEC
0.01 PEC
0.43 PEC
As required, SP
As required, BIdg,
1.43 PEC+ SP +
Bidg.
0.10 PEC
0.05 PEC
0.10 PEC
0.02 PEC
0.01 PEC
0.03 PEC
0.31 PEC
1,600
2,800
1,600
400
2,000
200
8,600
$ 28,600 +
SP -i- BIdg.
2,000
1,000
2,000
400
200
600
$ 6,200
Total Capital Cost
RTCC (fromTable 4.8-4)
TCC of total system
(including refrigeration}
1.74 PEC +
SP + BIdg.
$ 34,800
107,000
$ 142,060
4-63
-------
Table 4.8-6. Annual Cost Factors for Condenser Systems*
Cost Item Factor
Direct Cost, DAC
Utilities
Electricity
Refrigerant
Operating Labor
Operator labor
Supervisor
Maintenance
Maintenance labor
Materials
Indirect Costs, IAC
Overhead
Administrative
Property tax
Insurance
Capital recovery*
Recovery Credits
$O.OS9/kWh
0
$12.96/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
0.60 (Operating labor &
maintenance)
2% of TOO
1%ofTCC
1% of TOO
0.1628 (TCC)
As applicable
«References 4 and 9
* Capital recovery factor Is estimated as:
where:
interest rate,
10 percent
equipment life,
10 yrs.
4.8.6 References
1. McCabe, W.L, and J.C. Smith. Unit Operations
of Chemical Engineering. Third Edition. McGraw-
Hill Book Company. New York. 1976.
2. Chemical Engineering Reference Manual.
Robinson, R.N. Fourth Edition, Professional
Publications. Belmont, CA. 1987.
3. Chemical Engineers Handbook. Perry, R.H. and
C.H. Chiiton, eds. Sixth Edition. McGraw-Hill
Book Company. New York. 1980.
4, U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. (NTIS PB91 -228809)
EPA 625/6-86-014. Cincinnati, OH. September
1986.
5. Kern, D.Q. Process Heat Transfer. McGraw-Hill
Book Company, Inc. and Koga Kusha Com-
pany, Ltd. Tokyo, 1950.
6. Ludwig, E.E. Volume III. Applied Process De-
sign for Chemical and Petrochemical Plants.
Gulf Publishing Company. Houston, TX. 1965.
7. Lange's Handbook of Chemistry. Dean, J.A.,
ed. Twelfth Edition. McGraw-Hill Book Com-
pany. New York. 1979.
8. Hall, R.S., Vatavuk, W.M., and J. Matley. Esti-
mating Process Equipment Costs. Chemical
Engineering. November 21,1988.
9. U.S. EPA. OAQPS Control Cost Manual Fourth
Edition, EPA 450/3-90-006 (NTIS PB90-
169954). Research Triangle Park, NC. January
1990.
10. C.L Yaws, H.M. Ni, and P.Y. Chiang. Heat
Capacities for Organic Compounds. Chemical
Engineering. Vol. 95, No. 7, May 9,1988.
11. D.L Fijas. Getting Top Performance from Heat
Exchangers. Chemical Engineering. Vol. 96,
No. 12, December 1989.
12. J.S. Forrester, J.G. LeBlanc. A Cool Way to
Reduce Emissions. Chemical Engineering. Vol.
95, No. 8, May 23,1988.
13. Correspondence. Richard Waldrop, Edwards
Engineering, to Michael Sink, PES. August 20,
1990.
4.9 Fabric Filters
Fabric filter collectors (also known as baghouses) are
oneof the most efficient means of separating paniculate
matter from a gas stream. Fabric filters are capable of
maintaining mass collection efficiencies of greater than
99 percent down to a particle size approaching 0.3 urn
in most applications.1-2'3-12'13 This efficiency is largely
insensitive to the physical characteristics of the gas and
dust, and, depending on fabric cleaning method, to the
inlet dust loading.1'4 A large portion of the energy needed
to operate the system appears as pressure drop across
the bags, system hardware, and ducting. Typical system
pressure drop values range from 5 to 20 inches of water.
Limitations on the applicability of fabric filters are im-
posed by emission stream characteristics (e.g., tem-
perature, corrosivity, and moisture content) and particle
characteristics (primarily "stickiness"). However, recent
advances in fabrics have resulted in greater applicabil-
ity. For example, temperatures of 500°F with surges to
550°F are now routinely accommodated.11-14
Important process variables considered in baghouse
design include fabric type, cleaning method, air-to-cloth
ratio, and equipment configuration (i.e., forced draft or
induced draft). The filter fabric, cleaning method, and
air-tp-cloth ratio all should be selected concurrently;
choice of these parameters is mutually dependent.1
Equipment configuration is of secondary importance
unless site-specific space limitations exist that require
configuration to be of primary importance in the fabric
filterdesign. The operating parameter usually monitored
is the pressure drop across the system. Typically,
baghouses are operated within a certain pressure drop
range, which is determined based on site experience.
Currently, work is being done on electrostatically en-
hanced fabric filters. This technique, employed at pilot
plant baghouses, has shown significantly lower pres-
4-64
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sure drops than conventional designs. Preliminary cost
analysis studies have indicated that electrostatically en-
hanced baghouses may have lower lifetime costs than
conventional bag-houses. However, this technique is
still in the design stage and therefore is not discussed
below. Reference 11 contains more information on this
technique.
Fabric filter systems typically are designed on the basis
of empirical information obtained through testing and
long-term actual operating experience forsimilarcombi-
nations of cleaning method, fabric type, and dust rather
than by analytical methods.1 Although theoretical equa-
tions exist to predict the performance of filtering systems
under various conditions, these equations are beyond
the scope of this manual. A more rigorous discussion on
fabric filter theory and design can be found in the
OAQPS Control Cost Manual (Reference 11). Discus-
sion of baghouse design in this section provides qualita-
tiveguidance ratherthan predictive equations. Generally,
fabric filter design for HAPs is no different than fabric
filter design for control of any other type of paniculate
matter. However, due to the hazards associated with
HAPs, greater care must betaken to ensure that control
is consistently of high efficiency and that the control
device is leak-proof, thus preventing accidental release
of the gas stream and captured pollutants. For these
reasons, design of a fabric filter system for HAPs shou Id
specify an induced draft fan (i.e., a negative pressure or
suction baghouse) ratherthan a forced draft fan (i.e., a
positive pressure baghouse). Information presented in
this section can be used to provide guidance for or to
evaluate the appropriateness of baghouse design for
certain HAP applications.
Appendix C.9 provides a worksheet to record the infor-
mation obtained during the performance of the fabric
filter design procedures.
4.9.1 Data Required
The data necessary to perform the design steps consist
of the HAP emission stream characteristic previously
compiled on the "HAP Emission Stream Data Form" and
the required HAP control as determined by the appli-
cable regulations.
In the case of a permft review for a faorfc frfter, ffie
following data should be supplied by the applicant. The
design criteria and considerations discussed in this
section will be used to evaluate the reasonableness of
the applicant's proposed design.
1. Filter fabric material,
2. Cleaning method
3. Air-to-cloth ratio ft/min
4. Baghouseconfiguration
5. System pressure drop range.
_(ft3/min)/ft2
jn.H2O
4.9.2 Pretreatment of the Emission Stream
As discussed in Section 3.3.1, the temperature of the
emission stream should be within 50 to 100°F above the
stream dew point. If a emission stream is too close to its
dewpoint, moisture can condense and cause corrosion
as well as ruptures in bags. This problem is excerbated
if acid gas (e.g., S03) is present. Procedures for deter-
mining the dew point of an emission stream are provided
in Appendix B.1. If the emission stream temperature
does not fall within the stated range, pretreatment (i.e.,
emission stream preheating or cooling) is necessary.
Methods of pretreatment are briefly discussed in Appen-
dix B.3. If pretreatment is performed, the emission
stream characteristics will be altered. The primary char-
acteristics affecting baghouse design are emission
stream temperature and flow rate. Therefore, after se-
lecting a temperature for the emission stream, the new
stream flow rate must be calculated. The calculation
method depends upon the type of pretreatment per-
formed; use appropriate standard industrial equations.
The use of pretreatment mechanical dust collectors may
also be appropriate. If the emission stream contains an
appreciable amount of large particles (20 to 30 um),
pretreatment with mechanical dust collectors is typically
performed. Appendix B.3 further describes the use of
mechanical dust collectors.
4.9.3 Fabric filter System Design Variables
Successful I design of a fabric filter depends on the proper
selection of fabric and cleaning method and on an
adequate air-to-cloth ratio. All fabric filter systems share
the same basic features and operate using the principle
of aerodynamic capture of particles by fibers. Systems
vary, however, in certain key details of construction and
in the operating parameters. The design variables of
particular interest are filter bag material, fabric cleaning
method, air-to-cloth ratio, baghouse configuration (i.e.,
forced or induced draft), and materials of construction.
As stated earlier, the first three variables should be
considered concurrently. The configuration and con-
struction materials are important, but secondary, con-
siderations. The following subsections discuss
step-by-step procedures for selecting each of these
design variables as they may apply to a specific panicu-
late HAP control situation. Because HAP control is
similar to paniculate control in general, a good verifica-
tion of these procedures can be accomplished by con-
sulting the section about the particular industry in a
4-65
-------
document entitled "Control Techniques for Paniculate
Emissions from Stationary Sources- Volumell," or in the
Mcllvaine Fabric Filter Manual.4'8 [Note: Because these
design variables are considered concurrently, the "Ex-
ample Case" is presented at the end of Section 4.9.3.]
4.9.3.1 Fabric Type
Several types of natural and synthetic fabric are used in
baghouse systems. Gas stream characteristics, such as
temperature, acidity, alkalinity, and paniculate matter
properties (e.g., abrasiveness and hygroscopicity), de-
termine the fabric type to be used.1-8 In many instances,
several fabric types will be appropriate, and a final
selection will be chosen only when the cleaning method
and the desired air-to-cloth ratio are considered.
Most of the principal synthetic fibers have been adapted
for use as filtering fabrics while the only natural fibers in
common use are cotton and wool. Some of the more
common synthetic fibers in commercial use are nylon
(aromatic and polyamide), acrylic, polyester, polypro-
pylene, fiberglass, and fluorocarbon. Natural fibers can
be used for gas temperatures up to 200°F but have only
moderate resistance to acids and alkalis contained in
the gas stream.1-4-6 Synthetics have successfully oper-
ated at temperatures up to 550°F and generally have
greater chemical resistance.1-4-6 Recent additional ad-
vances In synthetic ceramics (Nextel 312™) have re-
sulted in increasing operating temperatures to 9pO°F.
The ability to operate at these temperatures can signifi-
cantly reduce any temperature pretreatment require-
ments necessary for successful operation. However,
little cost information of this new fabric type is available,
except that it is considerably more expensive than
Teflon™.12 Therefore, while the initial cost of the syn-
thetic filter fabric is greater than the cost for natural
fibers, the increased service life and improved operating
characteristics of the synthetics make them a preferred
choice in a wide range of industrial situations. Almost all
of the filter fabrics can be constructed in either a woven
or a felted manner (cotton and fiberglass can be con-
structed in a woven manner only). Woven fabrics are
made up of yam in one of a variety of patterns that allow
spaces between the fibers, whereas felted fabrics are
composed of a thick mat of randomly oriented fibers.
When woven fabrics are new, particles penetrate the
pores of the fabric fairly easily. As filtering continues,
however, more particles are retained on the f ilterthreads
and on the particles already collected. If a woven fabric
is equipped with a backing (e.g., Gore-Tex™), it per-
forms more similarly to felted fabrics.
As this dust layer or "cake" builds up.particle penetration
drops to a very tow level. Cleaning of woven fabrics must
be performed so that a layer of this dust cake remains on
the fabric, enabling particle penetration to remain Iow.1-s
Felted fabrics are thick enough that a dust cake does not
need to remain on the fabric in order to maintain a good
collection efficiency.1-4 This difference between woven
and felted fabrics has important implications for selec-
tion of fabric cleaning method, as described in Section
4.9.3.2, unless a suitable backing enables woven fabrics
to perform similarly to felted.
Information on the maximum continuous operating tem-
perature and resistance characteristics of commonly
used filter fabrics is presented in Table 4.9-1. Knowing
the emission stream characteristics, Table 4.9-1 can be
used to select an appropriate fabric filter type (ortypes).
Although the information presented is qualitative, Table
4.9-1 provides a good basis either for selecting a fabric
or for evaluating the appropriateness of a fabric in a
permit application.
When a number of fabrics are suitable for an application,
the relative cost of the fabrics may be the key decision
criterion. In general, ceramic, fluorocarbon, and nylon
aromatic bags are the most expensive, followed by wool
and fiberglass. The remaining commonly used synthet-
ics are generally less expensive than fiberglass (polypro-
pylene, polyester, acrylic, nylon polyamide, and
modacrylic), while cotton is generally the least expen-
sive fabric.2'3'4'7
4.9.3.2 Cleaning Method
As dust accumulates on the filtering elements, the
pressure drop across the bag compartment increases
until cleaning of the bags occurs. Usually a timer is used
to control the cleaning cycle, or the pressure drop is
monitored so that cleaning occurs when some maximum
desirable value is reached. At this point the bags in the
compartment are cleaned to remove the collected dust
and the cycle is then repeated. The two basic mecha-
nisms used to accomplish bag cleaning are flexing of the
fabric to break up and dislodge the dust cake, and
reversed air flow through the fabric to remove the dust.1
These may be used separately or in conjunction wKhone
another. The three principal methods used to accom-
plish fabric cleaning are mechanical shaking (manual or
automatic), reverse airflow, and pulse-jet cleaning. The
first method uses only the fabric flexing mechanism; the
latter two methods use a combination of the reverse air
flow and fabric flexing mechanisms.
Selection of a cleaning method is based on the type of
fabric used, the pollutant collected, and the
manufacturer's, vendor's, and industry's experiences. A
poor combination of filter fabric and cleaning method
can cause premature failure of the fabric, incomplete
cleaning, or blinding of the fabric.1 Blinding of a filter
fabric occurs when the fabric pores are blocked and
effective cleaning can not occur. Blinding can result
because moisture blocks the pores or increases the
adhesion of the dust, or because a high velocity gas
stream imbeds the particles too deeply in the fabric.1 The
selection of a cleaning method may be based on cost,
especially where more than one method is applicable.
Table 4.9-2 contains a comparison of cleaning methods.
Cleaning methods are discussed individually below.
With mechanical shaking, bags are hung on an oscillat-
ing framework that periodically shakes the bags at timed
intervals or at a predefined pressure drop level.1-3'6 The
shaker mechanisms produce a violent action on the
fabric filter bags and, in general, produce more fabric
wearthan the othertypes of cleaning mechanisms.3 For
4-66
-------
Table 4.9-1. Characteristics of Several Fibers Used in Fabric Filtration*
Resistance0
Fiber
Type"
Cotton"
Wool-
Modacrylic*
(Dynel™)
Polypropylene8
Nylon Poiyamide"
(Nylon 6 & 66)
Acrylic*
(Orion™)
Polyester":
Dacron1
Creslan™
Nylon Aromatic"
(Nomex™)
Fluorocarbon"
(Teflon™, TFE)
Fiberglass"
Ceramics1
(Nextel 312™)
Max.
Operating
Temp., °F
180
200
160
200
200
260
275
250
375
450
500
900+
Abrasion
VG
F/G
F/G
E '
e
G
VG
VG
i
F/G
F/G*
—
Mineral
Acids
• P
VG
_ E
E
F
VG
G
G
F
E«
G
—
Organic
Acids
G
VG
E
E
F
G
G
G
G
E»
G
—
Alkalis
P
P/F
E
E
E
F/G
G
G
E
E»
G
—
Solvent
E
G
E •
G
E
E
- E
£•
E
E«
E
—
References 4,11,12.
Fabric limited.
P = poor resistance, F = fair resistance, G = good resistance, VG = very good resistance, and E = excellent resistance.
Woven fabrics only.
Woven or felted fabrics.
Considered to surpass all other fibers in abrasion resistance.
The most chemically resistant of all these fibers.
After treatment with a lubricant coating. ,
Dacron™ dissolves partially In concentrated H2SO4.
The ceramic fiber market is a very recent development. As a result, little information on long term resistance, and acid and alkali perfor-
mance has been documented.
this reason, mechanical shaking is used in conjunction
with heavier and more durable fabric materials, such as
most woven fibers.3-10 Bags with poor or fair abrasion
ratings in Table 4.9-1 (e.g., fiberglass) should not be
chosen for fabric filters cleaned by mechanical shaking
unless they are treated with a special coating (i.e., a
backing) before use. Although shaking is abrasive to the
fabric, ft does allow a dust cake to remain on the fabric,
thus maintaining a high collection efficiency.
Bags are usually taken off-line for cleaning by mechani-
cal shaking so that no gas flows through the bags being
cleaned. Thus, reentrainment of particles is minimized.
Because dust dislodgement is not severe (i.e., a light
dust cake remains on the fabric), and because cleaning
occurs off-line, outlet concentrations are almost con-
stant with varying inlet dust loading and through entire
cleaning cycles when using mechanical shaking.1 Fur-
ther, control efficiency is very high.4 For these reasons,
mechanical shaking is a good method to clean fabric
filters controlling emissions containing HAPs.*
Table 4.9-2. Comparison of Fabric Filter Bag Cleaning
Methods*
Cleaning Method
Parameter
Cleaning on- or
off-line
Cleaning time
Cleaning uniformity
Bag attrition
Equipment
ruggednoss
Fabric type*
Filter velocity
Power cost
Oust loading
Maximum
Mechanical
Shake
Off-line
High
Average
Average
Average
Woven
Average
Low
Average
High
Reverse
Airflow
Off-line
High
Good
Low
Good
Woven
Average
Low to
Medium
Average
High
Pulse-jet
Individual
Bags
On-line
Low
Average
Average
Good
Felt/
Woven1"
High
High to
Medium
Pulse-jet
Compart-
mented
Bags
Off-line
Low
Good
Low
Good
FeW
Woven"
High
Medium
Very high High
Medium
Medium
temperature0
Collection
efficiency
Good
Good
Good*
Good*
Reference 4,11,12.
With suitable backing, woven fabrics can perform similarly to felted.
Fabric limited.
For a properly operated system with moderate to low pressures, the
collection efficiency may rival other methods.
4-67
-------
Reverse air flow cleaning is used to flex or collapse the
filter bags by allowing a large volume of low pressure air
to pass countercurrent to the direction of normal gas
stream flow during filtration.3'6 Reverse air is provided
either by a separate fan or by a vent in the fan damper,
which allows a backwash of air to clean the fabric
filters.3'6 Reverse air flow cleaning usually occurs off-
line. Reverse air cleaning allows the use of fragile bags,
such as fiberglass, or lightweight bags, and usually
results in longer life for the bags.3 As with mechanical
shaking, woven fabrics are used, and because cleaning
is less violent than with pulse-jet cleaning and occurs off-
line, outlet concentrations are almost constant with
varying inlet dust loading and throughout the cleaning
cycle. Reverse air flow cleaning is, therefore, a good
choice for fabric cleaning in HAP control situations.
In pulse-jet cleaning, a high pressure air pulse is intro-
duced into the bag from the top through a compressed
air jet.3-* This rapidly expands the bag, dislodging the
particles. Thus, the fabric is cleaned thoroughly through
a vibration effect. The pulse of air cleans so effectively
that no dust cake remains on the fabric to contribute to
paniculate collection. Because such a cake is essential
tor effective collection on woven fabrics, felted fabrics
are generally used in pulse-jet cleaned fabric filters.1
Alternatively, woven fabrics with a suitable backing may
be used. All of the fabric materials may be used with
pulse-jet cleaning except cotton or fiberglass. Previ-
ously, mechanical shaking was considered superior to
pulse-jet in terms of collection efficiency. Recent ad-
vances in pulse-jet cleaning have resulted in efficiencies
that may rival mechanical shaking.
Because the cleaning air pulse may be of such high
pressure (up to 100 psi) and short duration (<0.1 sec),
cleaning may be accomplished on-line but off-line clean-
ing is also employed. Extra bags may not be necessary,
therefore, to compensate for bags off-line during clean-
Ing. Cleaning occurs more frequently tnan with mechani-
cal shaking or reverse air flow cleaning, which permits
higher air velocities (higher A/C ratios) than the other
cleaning methods. Further, because the bags move less
during cleaning, they may be packed more closely
together. In combination, these features allow pulse-jet
cleaned fabric fitters to be installed in a smaller space,
and thus, at a tower cost, than fabric filters cleaned bythe
other methods.1-6 This cost savings may be somewhat
counterbalanced by the greater expense and more
frequent replacement required of bags, the higher power
use that may occur, and the installation of the fabric filter
framework that pulse-jet cleaning requires.1-8
In the past, pulse-jet systems have not been recom-
mended for HAP applications. Reasons for this recom-
mendation included particle reentrainment from the
cleaning cycle, reduced filtering efficiency due to rela-
tively little cake buildup, and the fact that pulse-jet
system efficiency is strongly dependant on particle load-
ing.
However, recent developments in pulse-jet cleaning
have resulted in the use of lower pressure equipment.
Several vendors now offer medium and low pressure
equipment (10-50 psi) that reduce the particle
reentrainment and hence increase the system efficiency.
Moreover, pulse-jet systems can operate with efficien-
cies exceeding 99.9 percent. Little side by side compari-
son of performance with reverse air or mechanical
shaking has been done. Therefore specific conclusions
on relative performance between cleaning types cannot
be made with a high degree of certainty. Based on the
above, it is believed that pulse-jet cleaning can be used
for HAP applications provided the system is properly
designed and maintained.
4.9.3.3 Air-to-Cloth Ratio
The air-to-cloth (A/C) ratio, or filtration velocity, is a
traditional fabric filter design parameter defined as the
actual volumetric flow rate (acfm) divided by the total
active, or net, fabric area (ft2). The A/C ratio is an
important indicator of the amount of air that can be
filtered in a given time when considering the dust to be
collected, cleaning method and fabric to be used, and
the characteristics of the gas stream to be filtered for an
individual situation. Selection of an appropriate range of
A/C ratios is not based on any theoretical or empirical
relationship, but, rather, is based on industry and fabric
filter vendor experience from actual fabric filter installa-
tions. A ratio is usually recommended fora specific dust
and a specific cleaning method. For typical design
calculations, the A/C ratio must be obtained from the
literature or the manufacturer.
The A/C ratio isdifficuftto estimate accurately from basic
design equations. At best, a general indication of this
ratio is obtained from hand calculations, and in fact
tabulated values are frequently used to provide an
approximation. More rigorous design procedures exist
in available computer model programs. However, the
purpose of this section is to provide the reader with some
qualitative insight concerning the design and operation
of fabric filters. Therefore, these programs are not dis-
cussed.
A summary of the ranges of recommended A/C ratios
by typical bag cleaning method for many dusts and
fumes is found in Table 4.9-3. These ranges are meant
to serve as a guide; A/C ratios may vary from those
reported. Fabric filter size and cost will vary with A/C
ratio; tower A/C ratios, for example, will require that a
larger and thus more expensive fabric filter be installed.
4-68
-------
Table 4.9-3. Alr-to-Cloth Ratios**
Shaker/Woven
Dust Reverse-Air/Woven
Alumina 2.5
Asbestos 3-0
Bauxite 2.5
Carbon black 1 .5
Coal 2.5
Cocoa, chocolate 2.5
Clay 2.5
Cement 2.0
Cosmetics 1.5
Enamel frit 2.5
Feeds, grain 3,5
Feldspar 2,2
Fertilizer 3.0
Floor 3.0
Fly ash 2.5
Graphite 2.0
Gypsum 2.0
Iron ore 3.0
Iron oxide 2.5
Iron sulfate 2.0
1 Aftri fwfHfi P O
L.OGIM UAlWO • C->W
Leather dust 3.5
Lime 2.5
Limestone 2.7
Mica 2.7
Paint pigments 2.5
Paper 3.5
Plastics 2.5
Quartz 2.8
Rock oust 3.0
Sand 2.5
Sawdust (wood) 3.5
Silica 2.5
Slate 3.5
Soap detergents 2.0
Spices 2.7
Starch 3.0
Sugar 2.0
Talc 2.5
Tobacco 3.5
Zinc oxide 2.0
Pulse
JeVFelt
B
10
8
"5
8
12
9
8
10
9
14
9
8
12
5
5
10
11
7
6
c
CJ
12
10
8
9
7
10
7
9
10
12
7
12
5
10
8
7
10
13
5
* Generally safe design values — application requires consideration
of particle size and grain loading. A/C ratio units are
Net cloth area is the cloth area in active use at any point
in time. Gross (or total) cloth area (A,c), by comparison,
is the total cloth area contained in a fabric filter, including
that which is out of service at any point in time for
cleaning or maintenance. In this manual, costing of the
fabric filter structure and fabric filter bags uses gross
cloth area. Table 4.9-4 presents factors to obtain gross
cloth area from net cloth area:
A.K, x Factor = Ate
where:
Factor = value from Table 4.9-4, dimensionless
AB = gross cloth area, ft2
Fabric filters with a higher A/C ratio require fewer bags
to accomplish cleaning, and, therefore, require less
space and maybe less expensive. Other costs, such as
more expensive (felted) bags, bag framework structure,
use of increased pressure drop and corresponding
increased power requirements, etc., may counterbal-
ance to some degree the savings of high A/C ratio
systems.
Table 4.9-4. Factors to Obtain Gross Cloth Area from Net
Cloth Area1
Net Cloth Area, Aw Factor to Obtain
(ft2) Gross Cloth Area, A,0 (ft2)
1 - 4,000 Multiply by 2
4,001 - 12,000 Multiply by 1.5
12,001 - 24,000 Multiply by 1.25
24,001 - 36,000 Multiply by 1.17
36,001 - 48,000, Multiply by 1.125
48,001 - 60,000 Multiply by 1.11
60,001 - 72,000 Multiply by 1.10
72,001 - 84,000 Multiply by 1.09
84,001 - 96,000 Multiply by 1.08
96,001 - 108,000 Multiply by 1.07
108,001 - 132,000 . Multiply by 1 .06
132,001 - 180,000 Multiply by 1,05
area)
Reference 11.
In addition to evaluating a particular fabric filter applica-
tion, the A/C ratio and the emission stream flow rate
(Q0.a) are used to calculate net cloth area (Ax).
Qe,a
A/C ratio
where:
A/C ratio =
(4.9-1)
emission stream flow rate at actual
conditions, acfm
air-to-cloth ratio, acfm/ft8 or ft/min
(from Table 4.9-3)
net cloth area, ft2
4-69
• Reference 11.
4,9.3.4 Baghpuse Configuration
The basic configuration of a baghouse varies according
to whether the gases are pushed through the system by
a fan located on the upstream side (forced draft fan), or
pulled through by locating the fan on the downstream
side (induced draft fan). A baghouse using forced draft
fans is called a positive-pressure baghouse; one using
induced draft fans is called a negative-pressure or
suction baghouse. Positive-pressure baghouses may
be either open to the atmosphere or closed (sealed and
pressure-isolated from the atmosphere). Negative pres-
sure baghouses can only be of the closed type. Only the
closed suction design should be selected for a HAP
application to prevent accidental release of captured
pollutants.6 The lower the gas stream dew point, the
greater the precaution that must be taken to prevent
condensation, which can moisten the filter cake, plug the
cloth, and promote corrosion of the housing and hop-
pers. In a suction-type fabric filter, infiltration of ambient
air can occur, which can lower the temperature below
design levels.
-------
Therefore, the structure walls and hoppers of this type of
baghouse should be insulated to minimize the possibility
of condensation.
4.9.3.5 Materials of Construction
The most common material used in fabric filter construc-
tion is carbon steel. In cases where the gas stream
contains high concentrations of SO3 or where liquid-gas
contact areas are involved, stainless steel may be
required. Stainless steel will increase the cost of the
fabric filter significantly when compared to carbon steel.3
However, by keeping the emission stream temperature
abovethedewpoint and by insulatingthe baghouse, the
use of stainless steel should not be necessary.
Example Case/ : •, .= .
Recall that the emission stream temperature- is
400*F, the S09 content is 200 ppmy, and the
siort stream temperature .are ceramics {Nexfet
312™}, nylon aromatic (Nomex™)i fluorocarbon
(Teflon™), and fiberglass. Because there Is a high
potentialfor acid damage (i.e., a high SQacontent},
however, Nomex bags should not be considered.
To obtain an indication of the A/C ratio', use Tabte
4.9-3, This table showsfhat an A/C t^tio of around
2.5 is expected for mechanical shaking or reverse
air cleaning, and an A/0 ratio erf about 5,0 is
expected for pulse |et cleaning.
A fiberglass bag would provide the most protection
during temperature surges (unfess ceramics are
used), and because fiberglass bags may be less
expensive, it may be the fabric of choice for an
installation with these emissions characteristics-
Fiberglass bags would require that reverse air
oleaningbe used, unless asuitable backing allows
pulse-fet cleaning. Teflon™ bags with meehanicaf
shaking could also be a possibiltty^References
4,5). Little information on the long-term effective-
ness of ceramics has been documented. It is ex-
pected that ceramic fibers wilt have'performance
characteristics similar to the best synthetic fibers,.
but will likely cost significantly more.
4.9.4 Determination of Baghouse Operating
Parameters
Many times, optimization of a fabric filter's collection
efficiency occurs in the field after construction. The
following discussion does not pertain to the preliminary
design of a fabric filtration control system; however, the
information presented should be helpful in achieving
and maintaining the desired collection efficiency for the
installed control system.
4.9.4.1 Collection Efficiency
To discuss fabric filter "collection efficiency" is some-
what of a misnomer because a properly operated sys-
tem yields fairly constant outlet concentrations over a
broad range of inlet loadings. As such, the system really
does not operate as an efficiency device and outlet
concentrations are not a strong function of inlet loading.
Typical outlet concentrations range between 0.001 to
0.01 gr/dscf, averaging around 0.003 - 0.005 gr/dscf.1s
However, the term "collection efficiency" can be applied
to a fabric filter system when describing performance for
a given application. For example, the outlet concentra-
tions given above will usually correspond to very high
collection efficiencies.
A well designed fabric filter can achieve collection effi-
ciencies in excess of 99 percent, although optimal
performance of a fabric filter system may not occur for a
number of cleaning cycles as the new filter material
achieves a cake buildup. The fabric filter collection
efficiency is related to the pressure drop across the
system, component life, filter fabric, cleaning method
and frequency, and A/C ratio. These operating param-
eters should be modified as discussed below if fabric
filter performance is less than desired or required. Modi-
fications to improve performance include changing the
A/C ratio, using a different fabric material, replacing
worn or leaking filter bags, and/or modifying the inlet
plenum to ensure the gas stream is evenly distributed
within the baghouse. Collection efficiency also can be
improved by decreasing the frequency of cleaning or
allowing the system to operate over a greater pressure
drop before cleaning is initiated.
4.9.4.2 System Pressure Drop
The pressure drop across the operating fabric filter
system is a fu net ton of the difficulty with which the gas
stream passes through the filter bags and accumulating
dust cake, how heavy the dust deposit is prior to bag
cleaning, how efficient cleaning is, and if the filter bags
are plugged or blinded. Normally, the value of this
parameter is set between 5 to 20 inches of water. In
actual operation, variations in pressure drop outside of
the design range may be indicative of problems within
the fabric filter system. Higher than expected pressure
differentials may indicate: (1) an increase in gas stream
volume; (2) blinding of the filter fabric; (3) hoppers full of
dust, thus blocking the bags; and/or (4) inoperative
cleaning mechanism. Lower than expected pressure
differentials may indicate: (1) fan or motor problems, (2)
broken or undamped bags, (3) plugged inlet ducting or
closed damper, and/or (4) leakage between sections of
the baghouse. Forthese reasons ft is recommended that
the system pressure drop be monitored continuously.
As the dust cake builds up during filtration, both the
collection efficiency and system pressure drop increase.
As the pressure drop increases toward a maximum, the
filter bags (or at least a group of the bags contained in
one isolated compartment) must be cleaned to reduce
the dust cake resistance. This cleaning must be timed
and performed so as to accomplish the following: (1) to
keep the pressure drop and thus operating costs, within
reasonable limits; (2) to clean bags as gently and/or
infrequently as possible to minimize bag wear and to
maximize efficiency; and (3) to leave a sufficient dust
layer on the bags to maintain filter efficiency and to keep
the instantaneous A/C ratio immediately after cleaning
4-70
-------
from reaching excessive levels, if woven fabric with no
backing is used.
In practice, these various considerations are balanced
using engineering judgment and field trial experience to
optimize thetotal system operation. Changes in process
or in fabric condition through fabric aging will cause a
shift in the cleaning requirements of the system. This
shift may require more frequent manual adjustments to
the automatic control to achieve the minimum cleaning
requirements.
4.9.5 Evaluation of Permit Application
Using Table 4.9-5, compare the results from this section
and the data supplied by the permit applicant. The
calculated values are based on the example case. As
pointed out in the discussion on fabric fitter design
considerations, the basic design parameters are gener-
ally selected without the involved, analytical approach
that characterizes many other control systems. There-
fore, in evaluating the reasonableness of any system
specifications on a permit application, the reviewer's
main task will be to examine each parameter in terms of
its compatibility with the gas stream and paniculate
conditions and with the other selected parameters. The
following questions should be asked:
1. Is the temperature of the emission stream enter-
ing the baghouse within 50 to 100°F above the
stream dew point?
2. Is the selected fabric material compatible
with the conditions of the emission stream;
that is, temperature and composition (see
Table 4.9-1)?
3. Is the baghouse cleaning method compatible
with the selected fabric material and its con-
struction; that is, material type and woven or
felted construction (see Section 4.9.3.2 and
Table 4.9-2)?
4. Will the selected cleaning mechanism provide
the desired control?
5. Is the A/C ratio appropriate for the application;
that is, type of dust and cleaning method used
(see Table 4.9-3)?
6. Are the values provided for the gas flow
rate, A/C ratio, and net cloth area consis-
tent? The values can be checked with the
following equation:
A/C ratio = 5^3.
n,c
where:
A/C ratio = air-to-cloth ratio, ft/min
Qe,» = emission stream flow rate at
actual conditions, acfm
AW = net cloth area, ft8
7. Is the baghouse configuration appropriate; that
is, is it a negative-pressure baghouse?
A particular manufacturer/customer combination may
employ somewhat different criteria in their selection of
design parameters (such as lower annualized costs of
operation at the expense of higher initial costs), and so
a departure from the "rules-of-thumb" discussed here
may still be compatible with achieving the needed high
collection efficiencies. Further discussions with the per-
mit applicant are recommended to evaluate the design
assumptions and to reconcile any apparent discrepan-
cies with usual practice.
4.9.6 Capital and Annual Costs of Fabric Fitters
Once the equipment has been sized, a study typ% cost
estimate can be obtained using the procedures below.
The procedure involves estima-ting the capital cost of a
system using a factored approach and obtaining the
annualized costs by summing the direct and indirect
annual costs.
Table 4.9-5. Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Fabric
niters
Process Variables
Calculated Value
(Example Case}*
Reported
Value
Continuous monitoring yes
of system pressure drop
and stack opacity
Emission stream 365 - 415°F
temp, range*
Selected fabric material fiberglas or Teflon™
Baghouse cleaning
method
A/C ratio
Baghouse configuration
mechanical, shaking,
reverse air flow, pulse-jet
2.5 ft/min for mechanical
shaking or reverse air;
5 ft/min for pulse-jet
negative pressure
* Based on the municipal incinerator emission stream.
"See Section 3.3.1.
4.9.6.1 Total Capital Costs
Total capital costs includes costs for the baghouse
structure, the initial complement of bags, auxiliary equip-
ment, and the usual direct and indirect costs associated
with installing or erecting new structures. These costs
are described below, and may be escalated if desired.
The example case assumes that escalation is not nec-
essary.
4-71
-------
Structure Cost
A guide to estimate the costs of six types of bare fabric
filter systems, which were taken from Reference 11, is
provided in Table 4.9-6.
Each figure gives costs for the fitter without bags and
additional costs for stainless steel construction and for
Insulation. Extrapolation of these lines is not recom-
mended. All units include unit and exhaust manifolds,
supports, platforms, handrails, and hopper discharge
devices. The indicated prices are flange to flange. Note
that the scales on axes differ.
Tablo 4.9-0. Quid* to Estimate Costs of Bar* Fabric Filter
Systems
Operation
Preassembled Units
Intermittent
Continuous
Continuous
Continuous
Continuous
Cleaning Mechanism
Shaker
Shaker
Pulse-jet (common housing)
Pulse-Jet (modular)
Reverse-air
Figure
4,8-1
4.9-2
4.9-3
4.9-4
4.9-5
Field-assembled units
Continuous
Any method
4.9-6
The 304 stainless steel add-on cost Is used when
stainless steel is necessary to prevent the exhaust
stream from corroding the interior of the baghouse as
mentioned previously. Stainless steel is substituted for
all metal surfaces that are in contact with the exhaust
gas stream.
Insulation costs are for 3 inches of shop-installed glass
fiber encased in a metal skin. One exception is the
custom baghouse, which has field-installed insulation.
Costs for insulation include only the flange-to-flange
baghouse structure on the outside of all areas in contact
with the exhaust gas stream. Insulation forductwork, fan
casings, and stacks must be calculated separately as
discussed later.
The costs for intermittent service, mechanical shaker
baghpuses (including the shaker mechanism ) as a
function of gross cloth area required are presented in
Rgure 4.9-1. Because intermittent service baghouses
do not require an extra compartment for cleaning, gross
and net fabric areas are the same.
The same costs for a continuously operated baghouse
cleaned by mechanical shaker as a function of the gross
cloth area are presented in Figure 4.9-2. As in Figure
4.9-1, the units are modular in construction. Costs for
these units, on a square foot basis, are higher because
of increased complexity and generally heavier construc-
tion.
Costs of common-housing pulse-jets units and modular
pulse-jet units are presented in Figures 4.9-3 and 4.9-4.
Modular units are constructed of separate modules that
may be arranged for off-line cleaning, while common-
Housing units have all bags within one housing. The
cleaning system compressor is not included. Because
the common housing is relatively inexpensive, the stain-
less steel add-on is proportionately higher than for
modular units. Added material costs and set-up and
labor charges associated with the less workable stain-
less steel account for most of the added expense.
The costs for the reverse-air baghpuses are shown in
Figure 4.9-5.15 The construction is modular and the
reverse-air fan is included. Costs for custom baghouses
which must be field assembled because of their large
size are given in Rgure 4.9-6. These units often are used
on power plants, steel mills, or other applications too
large for the factory-assembled baghouses.
Bag Costs, CB
The price per square foot (in 3rd quarter 1986 dollars) of
bags by type of fabric and by type of cleaning system
used is given in Table 4.9-7. The prices represent about
a 10 percent range. In calculating the cost, the gross
area as determined from Table 4.9-4 should be used.
These costs should be escalated using the index pro-
vided in Table 4.12-1. Gore-Tex™ fabric costs are a
combination of the base fabric cost and a premium for
the PTFE laminate and its application. As fiber market
conditions change, the costs of fabrics relative to each
other also change. The bag prices are based on typical
fabric weights, in ounces/square yard, for the fabric
being priced. Sewn-in snap rings are included in the
price, but other mounting hardware, such as clamps or
cages, is an added cost. Reference 11 can be used to
obtain the cost cages, flow control Venturis, and other
bag hardware.
Purchased Equipment Cost (PEC) and Total Capital
Costs (TCC)
The purchased equipment cost (PEC) of the fabric filter
system is the sum of the costs of the baghouse, bags,
auxiliary equipment, instruments and controls, and taxes
and freight costs. The factors necessary to estimate
these costs are presented in Table 4.9-8. Section 4.12
can be used to estimate the cost of auxiliary equ ipment.
The factors necessary to estimate the remaining direct
and indirect capital costs to obtain total capital costs are
provided in Table 4.9-8.
4-72
-------
150
8
a>
S; 125
I
5
1 100
is_
§ 75
5
ifi
8 50
• c
CD
a.
"5 9c
a-
•£ 500
3 • .
"S 40°
^'
ff 300
o 200
O
I' '
.9- 100
t
I T
Cost without bags
Stainless steel add on
Insulation add on
10 20 30 40 50 60
Gross Cloth Area (1,000 ft4)
70
80
90
Figure 4,9-2. Structure costs for continuous shaker filters.
4-73
-------
Caution: Do not extrapolate.
150,
I t25
100
75
50
25
1 I
6 8 10 12
Gross Cloth Area (1,000 fP)
Cost without bags
Stainless steel add on
Insulation add on
14
16
18
Figure 4.9-3. Structure costs for pulse-Jet filters (common housing).
150
fe 125
a
"E 100
8 75'
S
«
8 50
25
lu
Caution: Do not extrapolate.
I I I I
I
Cost without bags
Stainless steel add on
Insulation add on *
4 6 8 10 12 14 16 18
Gross Cloth Area (1,000 ft2)
Figure 4.9-4. Structure costs for pulse-jet filters (modular).
4-74
-------
600
500
400
J 200
c
(B
•" 100
3
Caution: Do not extrapolate.
I I I I
1 i
Cost without bags
10 20 30 40 50 60
Gross Cloth Area (1,000 ft*)
Stainless steel add on
Insulation add on —
70
80
90
Figure 4.9-5. Structure costs for reverse-air filters.
Caution: Do not extrapolate.
O
2500
2000
§ 1500
5 1000
'§'
f 500
LU
0
I I
Cost without bags
100 . 200 300
Gross Cloth Area (1,000 ft2)
400
Figure 4.9-6. Structure costs for custom-built filters.
4-75
-------
TabI* 4,9-7. Bag Pricas* (3rd quarter 1986 $/H2)
Type of Cleaning
Pulse jet, TR°
Pulse jet, BBR
Shaker
Strap top
Loop top
Reverse air with rings
Reverse air w/o rings*
Bag Diameter
(inches)
4-1/2 to 5-1/8
6to8
4-1/2 to 5-1/8
6 to 8
5
5
8
8
11-1/2
Type of Material"
PE
0,59
0.43
0.37
0.32
0.45
0.43
0.46
0.32
0.32
PP
0.61
0.44
0.40
0,33
0.48
0.45
NA
NA
NA
NO
1.88
1.56
1.37
1.18
1.28
1.17
1.72
1.20
1.16
HA
0.92
0.71
0.66
0.58
0.75
0.66
NA
NA
NA
FQ
1.29
1.08
1.24
0.95
NA
NA
0.99
0.69
0.53
CO
NA
NA
NA
NA
0.44
0.39
NA
NA
NA
TF
9.05
6.80
8.78
6.71
NA
NA
NA
NA
NA
NA - Not applicable.
•Reference 11,
'Materials:
PE «16-oz polyester
PP - 16-oz polypropylene
NO - 14-oz nomex
HA m 16-oz homopolymer acrylic
cBag removal methods:
FG - 16-oz fiberglass with 10% Teflon1"
CO - 9-oz cotton
TF = 22-oz Teflon™ felt
TR - Top bag removal (snap in)
BBR - Bottom bag removal
identified as reverse-air bags, but used in low pressure pulse applications.
Note: For pulse-Jet baghouses, all bags are felts except for the fiberglass, which is woven. For bottom access pulse-jets, the cage price for
one cage can be calculated from the single-bag fabric area using:
In 60 cage lots
In 100 cage lots
In 500 cage lots
$ » 4.941 + 0.163 ft2
$. 4.441 + 0.163 ff
$ - 3.941 +• 0.163 ft2
$
. 23.335 + 0.280 ft2
.21.791+ 0.263 ft2
•- 20.564 + 0.248 ft?
These costs apply to 4-1/2-in. or 5-5/8-in. diameter, 8-ft and 10-ft cages made of 11 gauge mild steel and having 10 vertical wires and
"Roll Band" tops. For flanged tops, and $1 per cage. If flow control Venturis are used (as they are in about half of tie pulse-jet
manufacturers' designs), add $5 per cage.
For shakers and reverse air baghouses, all bags are woven. All prices are for finished bags, and prices can vary from one supplier to
anottier. For Gore-Tex™ bag prices, multiply base fabric price by factors of 3 to 4.6.
Assume a reveraeF
ure 4.9-8'is
structure. Fo
structure requires stain
Jation.ThefirststepjstG^
cloth area. •-
From Table 4.9-3, .„_._ .„.„.... _.
Thus AO, «(i ^.oaQ-acfrnji^igi^iiii
4-7&
-------
Table 4.9-3. Capital Coat Factors for Fabric Fitters*
Direct Costs
Factor
Purchased Equipment Costs;
Fabric filter
Bags
Auxiliary equipment
Instruments & controls
Taxes
Freight
As estimated
As estimated
As estimated
(EC = Sum of
As estimated)
0.10 EC
0.03 EC
0.05 EC
Purchased Equipment Cost, PEC PEC = 1.18 EC
Installation Direct Costs
Foundation & supports
Erection & handling
Electrical
Piping
' Insulation for ductwork1"
Painting0
Site preparation (SP)
Buildings (Bldg.)
Total Direct Cost, DC
Indirect Costs
Engineering & supervision
Construction and field expense
Construction fee
Start-up fee
Performance test
• Contingencies
Total Indirect Cost, 1C
Total Capital Cost (TCC) - DC + 1C
0.04 PEC
0.50 PEC
0.08 PEC
0.01 PEC
0.07 PEC
0.02 PEC
As required
As required
0.72 PEC
+ SP
+Bldg.
1.72 PEC
+SP
+ Bldg.
0.10 PEC
0.20 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.45 PEC
2.17 PEC
+ SP
+ Building
• Reference 11.
b If ductwork dimensions have been established, cost may be estab-
lished based on $10 to $12/ft2 of surface for field application. Fan
housings and stacks may also be insulated.
" The Increased use of special coatings may increase this factor to
0,06 PEC or higher.
4.9.6.2 Annualized Costs for Fabric Filter Systems
The annual costs for a fabric filter system consist of the
direct and indirect operating costs these costs are dis-
cussed in more detail below. Table 4.9-10 provides the
cost factors used to estimate annual costs.
Direct Costs, Direct costs include utilities (electricity,
replacement bags, compressed air), operating labor,
and maintenance costs.
The cost of electricity Is largely a function of the fan
power requirement. Equation 4.9-2 can be used to
estimate this requirement assuming a 65 percent fan-
motor efficiency and a fluid specific gravity of 1.00.
Fp= 1.81x10-* (Q8.a)(P)(HRS)
where:
Fp = fan power requirement, kWh/yr
(4.9-2)
Qe,a = emission stream flow rate, acfm
P = system pressure drop, in. H20
MRS = operating hours,hrs/yr
For mechanical shaking, the additional power require-
ment can be estimated using Equation 4.9-3.
* ms
where:
' ms
(4.9-3)
mechanical shaking power requirement,
kWh/yr
gross cloth area, ft2
The annual electricity cost is calculated as the sum of Fp
and Pm multiplied by the cost of electricity given in Table
4.9-10.
For a pulse-jet system, the consumption of compressed
air is about 2 scfm/1 ,000 scfm of the emission stream.
For example, a 1 00,000 scfm stream will consume about
200 scfm. This would then need to be multiplied by both
60 and by HRS to obtain the total yearly consumption.
This value is then multiplied by the cost of compressed
airgiven in Table 4.9-1 0 to obtain annual costs. For other
cleaning mechanisms, this consumption is assumed to
be zero.
The cost of replacement bags is obtained from Equation
4.9-4.
= jpe -f CJ CRFB
(4.9-4)
where:
CRB
CB
CL
= bag replacement cost, $/yr
= initial bag cost, $
= bag replacement labor, $ (CL = $0. 1 4 A,*.)
CRFB = capital recovery factor, 0,5762 (indicates a
two year life, 10 percent interest)
The bag replacement labor cost depends on such fac-
tors as the number, size, and type of bags, the accessi-
bility of the bags, how they are connected to the
tube-sheet, etc. As such , these costs are highly variable.
For simplicity, assume a conservatively high cost of
$0.1 4/ft2 net bag area, per EPA guidance."
The cost of operating labor is estimated from a labor
requirement of 3 hours per 8 hour shift and the operator
labor wage rate provided in Table 4.9-1 0. Supervisory
costs are taken as 15 percent of operator labor costs.
The cost of maintenance is estimated from a mainte-
nance labor requirement of 1 hour per 8 hour shift and
4-77
-------
Table 4.9-9. Example Case Capital Costs
Direct Costs
Factor
Cost($)
Purchased Equipment Costs:
Fabric filter
Bags
Auxiliary equipment
Instruments & controls
Taxes
Freight
Purchased Equipment Cost, PEC
Installation Direct Costs
Foundation & supports
Erection & handling
Electrical
Piping
Insulation for ductwork1*
PalnHng"
Site preparation (SP)
Buildings (BIdg.)
Total Direct Costs
Indirect Costs
Engineering & supervision
Construction and field expense
Construction fee
Start-up fee
Performance test
Contingencies
Total Indirect Cost
Total Direct and Indirect Cost =
Total Capita] Cost (TCC)
As estimated
As estimated
As estimated
(EC=Sum of As
estimated)
0.10 EC
0.03 EC
j&QS-Efi
PEC. 1.18 EC
0.04 PEC
0.50 PEC
0.08 PEC
0.01 PEC
0.07 PEC
0.02 PEC
As required
As required
0.72 PEC + SP + BIdg.
1.72PEG + SP + Bldg.
0.10 PEC
0.20 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.45 PEC
2.17PEC + SP
-j-Bldg.
$
$
$
$
$
$
$
$
$
$
690,000
49,000
10.000
749,000
74,900
22,500
37,500
884,000
35,400
442,000
70,700
8,840
61,900
17,700
—
—
636,000
1,520,000
88,400
177,000
88,400
8,840
8,840
26,500
398,000
1,920,000
Table 4.9-10. Annual Costs for Fabric Filters*
Cost Item
Factor
Direct Costs, DAC
Utilities
Electricity
Compressed air
Replacement Parts, bags
Operating Labor
Operator
Supervisor
Maintenance
Labor
Material
Waste Disposal
Indirect Costs, IAC
Overhead
Administrative
Property tax
Insurance
Capital recovery6
$O.OS9/kWh
$0.16/10* scfm
See Section 4.9.6.2
$12.96/hr
15% of operator labor
$14.26/hr
100% of maintenance labor
Variable. See Section 4.9.6.2
0.60 (Operating labor
-i- maintenance)
2% of TCC
1% of TCC
1% of TCC
0.1175 (TCC - O.OSCt - 1.08 CB)
• Reference 11.
* Capital recovery factor is estimated as: l(1+i)"/(1+i)"-1
where: i - Interest rate, 10 percent
n - equipment life, 20 years
the wage rate provided in Table 4.9-10. The cost of
maintenance materials is assumed to equal the mainte-
nance labor costs.
The cost of dust disposal will vary widely from site to site.
The reader should make every effort to obtain accurate
costs for this item as this cost will typically be large.
Typical costs fall between $20/ton and ISO/ton for non-
hazardous waste, while hazardous material costs can
be 10 times this amount.11
Indirect Costs. Indirect costs consist of overhead, ad-
ministrative costs, property taxes, insurance, and capital
recovery. Table 4.9-10 provides the appropriate factors
to estimate these costs.
^•:^:^^!i!'^-:>itt^::::<::S::^V:::$:$:'S$::i:::'^;^v:;;::-::::;:^
4-78
-------
4.9.7 References
1. Siebert, P.O. Handbook on Fabric Filtration. ITT
Research Institute. Chicago, IL April 1977.
2. U.S. EPA. Handbook of Fabric Filter Technol-
ogy, Volume I: Fabric Filter Systems Study.
APTD 0690 (NTIS PB 200648). December
1970.
3. U.S. EPA. Capital and Operating Costs of Se-
lected Air Pollution Control Systems. EPA-450/
5-80-002 (NTIS PB80-157282). December
1978.
4. The Fabric Filter Manual, The Mcllvaine Com-
pany. Northbrook, |L. 1975. Chapter HI,
5. U.S. EPA. Control Techniques for Paniculate
Emissions from Stationary Sources - Volume 2.
EPA-450/3-81 -005b (NTIS PB83-127480). Sep-
tember 1982.
6. U.S. EPA. Control Techniques for Paniculate
Emissions from Stationary Sources - Volume 1.
EPA-450/3-81 -OOSa (NTIS PB83-127498). Sep-
tember 1982.
7. Strauss, W, Industrial Gas Cleaning, 2nd Edi-
tion. Pergamon Press, Oxford, England. 1975.
8. U.S. EPA. Procedures Manual for Fabric Filter
Evaluation. EPA-600/7-78-113 (NTIS PB
283289). June 1978.
9. U.S. EPA. Air Pollution Engineering Manual.
AP-40 (NTIS PB 225132). May 1973.
10. U.S. EPA, Paniculate Control Highlights; Re-
search on Fabric Filtration Technology. EPA-
600/8-78-005d (NTIS PB 285393). June 1978.
11. U.S. EPA. OAQPS Control Cost Manual. 4th
edition, EPA 450/3-90-006 (NTIS PB90-
169954). January 1990.
12. G. Parkins. Baghouses Face the Heat. Chemi-
cal Engineering. Vol. 96, No. 4. April 1989.
13. U.S. EPA. Baghouse Efficiency on a Multiple
Hearth Incinerator Burning Sewage Sludge. EPA
600/2-89-016 (NTIS PB89-190318). January
1990.
14. U.S. EPA. Handbook: Guidance on Setting Per-
mit Conditions and Reporting Trial Burn Re-
sults. EPA 625/6-89-019. January 1989.
15. PES, Inc. Durham, NC. Company data for the
municipal waste combustion industry.
4-79
-------
4.10 Electrostatic Precipitators
Electrostatic precipitators (ESPs) use an electrostatic
field to charge participate matter contained in the gas
stream. The charged particles then migrate to a grounded
collecting surface. The collected particles are dislodged
from the collector surface periodically by vibrating or
rapping the collector surface, and subsequently collected
in a hopper atthe bottom of the ESP. ESPs typically have
a high collection efficiency and are very efficient at
controlling submicron (<1.0 um) particles common to
metal fumes, for example.
Two basic types of ESPs are: single stage and two
stage.1-2 In the single stage precipitator, which may be
wet or dry, fonlzatton and collection arecombined, whereas
in the two stage precipitator, ionizat ion and collection are
done in separate steps. Dry, single stage ESPs are the
most common. Several specific types of the single stage
ESP are employed. These include the plate wire type (the
most common), the flat plate, and the tubular. Wet
electrostatic precipitators, while not as common as dry
ESPs, can be used to remove both solid and gaseous
pollutants and are less sensitive to particle resistivity
characteristics as discussed in Section 4.10-3. A brief
description of these precipitator types follows.
In a plate wire ESP, gases flow between parallel plates of
sheet metal and high voltage electrodes. The electrodes
consist of long weighted wires hanging between the
plates and supported by rigid frames. The gases must
pass through the wires as they traversethe ESP unit. This
configuration allows many parallel lanes of flow and is
well suited for handling large volumes of gas. The clean-
ing and power supplies for this type are often sectioned,
to improve performance. The plate wire ESP is the most
popular type.
Flat plate ESPs differ from plate wire types in that the
electrodes consist of flat plates rather than wires. A
number of smaller precipitators use flat plates instead of
wires. These plates increase the average electric field
used to collect particles,and provide increased surface
collection area, relative to plate wires. A flat plate ESP
operates with little or no corona (a region of gaseous ions)
which leads to high rapping losses particularly if the
emission stream velocity is high. These ESPs perform
well with small, high resistivity particles provided the
velocity is tow.
Tubular ESPs are the oldest type and the least com-
mon. Tubular ESPs are typically used in sulfuric acid
plants, coke oven by product gas cleaning (tar re-
moval), and iron and steel sinter plants. The tube is
usually a circular, square, or hexagonal honeycomb
with gas flowing lengthwise through the system. The
tubular ESP is most commonly applied where the par-
ticles are wet or sticky.
The two stage ESP is a series device where the first unit
is responsible for ionization, and the second for collec-
tion. This results in more time for particle changing and
economical construction for smaller (<50,000 acfm) ap-
plications. Two stage units are often used to collect oil
mists, smokes, fumes and other sticky particulates
because there is little electrical force to hold the col-
lected particles onto the plates.
Ionizing wet scrubbers (IWS) also may be used as a
paniculate control device. Art IWS combines the prin-
ciple of wet electrostatic particle charging with packed
bed scrubbing into a two-stage collection system.8 Note
however, that IWS technology is not the same as a two-
stage ESP. A constant DC voltage is applied to the
ionizing section, which the emission stream passes
through before introduction to the scrubbing section.
The electrostatic plates in the ionizing section are
continually flushed with water to prevent resistive layer
buildup. The cleaned gas exiting the ionizing section is
further scrubbed in a packed bed section. Unlike dry
ESPs, IWSs are fairly insensitive to particle resistivity.
For best performance of IWSs, monitoring of plate
voltage and packed bed scrubbing water is recom-
mended. Design and cost equations for this technology
are not included, but it is mentioned here to introduce
the reader with this emerging technology.
A rigorous design of a given ESP system can become
quite complex as it normally includes a consideration of
electrical operating points (voltages and currents), par-
ticle charging, particle collection, and sneakage and
rapping reentrainment. For purposes of this handbook,
a simplified design procedure is presented. A more
rigorous design procedure is presented in Reference 7.
However, for purposes of quickly obtaining an approxi-
mate design and cost for a given ESP, the methodology
given below should suffice.
The most important variable considered in the design of
an ESP presented below is specific collection plate area
assuming that the ESP is already provided with an
optimum level of secondary voltage and current. Sec-
ondary voltage or current is the voltage or current level
at the plates themselves, and this voltage and current
are responsible for the electric field. Collection plate
area is a function of the desired collection efficiency, gas
stream flow rate and particle drift velocity.1-2-3'5'8 Other
design details to be estimated by the vendor include (but
are not limited to) expected secondary voltage and
current, electrical sections alignment, and direction of
gas flow.
Particle drift velocity is a complicated function of particle
size, gas velocity, gas temperature, particle resistivity,
particle agglomerization, and the physical and chemical
properties of the paniculate matter. The theoretical
relationship of the drift velocity to the variables is dis-
cussed extensively in the literature.1-2-3'5 Unfortunately,
there are no empirical equations readily available to
calculate drift velocity directly from these variables.
Therefore, in determining drift velocity for a given emis-
sion stream, equipment vendors often rely upon histori-
cal data for similar streams arid data established from
pilot plant tests. Published information on drift velocity
(based on design data for actual installations to repre-
4-80
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sent typical gas characteristics) are available for several
industrial emission streams.2-7
Appendix C.10 provides a worksheet to record the
information obtained duringthe performance of the ESP
design and cost procedures.
4.10.1 Data Required
The data necessary to perform the design steps consist
of the HAP emission stream data characteristics previ-
ously compiled on the "HAP Emission Stream Data
Forms" and the required HAP control as determined by
the applicable regulations.
I n the case of a permit review for an ESP, the following
data should be supplied by the applicant. The design
criteria and considerations discussed in this section
will be used to evaluate the reasonableness of the
applicant's proposed design.
1. Reported collection efficiency= %
2, Reported drift velocity of particles - ft/sec
3. Reported collection plate area =______ ft2
4.10.2 Pretreatment of the Emission Stream
As discussed in Section 3.2.1, the temperature of the
emission streams should be within 50 to 100°F above
the stream dew point. Procedures for determining the
dew point of an emission stream are provided in Appen-
dix B.1. If the emission stream temperature does not fall
within the stated range, pretreatment (i.e., emission
stream preheat or cooling) is necessary. Methods of
pretreatment are discussed briefly in Appendix B,3. The
primary characteristics affecting ESP sizing are drift
velocity of the particles and flow rate. Therefore, after
selecting a temperature for the emission stream, the
new stream flow rate must be calculated. The calcula-
tion method depends upon the type of pretreatment
performed; use appropriate standard industrial equa-
tions. The use of pretreatment mechanical dust collec-
tors may also be appropriate. If the emission stream
contains an appreciable amount of large particles (20 to
30 urn), pretreatment with mechanical dust collectors is
typically performed. Appendix B.3 further describes the
use of mechanical dust collectors.
4.10.3 ESP Design Variables
As mentioned earlier, an ESP collects particles by
imparting a charge into them and using electrical forces
to drive them to a collection plate. The particles are given
an electrical charge by forcing them through a region of
gaseous ions, called a corona. The corona is generated
by applying voltage to electrodes located within the
ESP. The ions migrate from the electrode area to the
collection surface by following electric field lines. Par-
ticles passing through the corona become attached to
these ions. Typically the particles must pass through a
series of coronas before they are collected.
Upon collection, the particles are dislodged from the
collection plate into a hopper. During dislodgement,
however, some particles become reentrained in the gas
stream reducing the overall collection efficiency. The
amount of particle reentrai nment significantly affects the
collection efficiency of the ESP. Another factor affecting
the collection efficiency is called "back Corona." Back
corona is due to particle buildup on the collection plates.
The ion current generated by the electrodes must pass
through the particle layer before reaching the ground
(collection) plate. This current gives rise to an electric
field in the layer, and can become large enough to cause
a local electrical breakdown. This breakdown condition
causes sparking and is called back corona.
Back corona is prevalent when the resistivity of the layer
is high, usually above 2 x 10" ohm-cm, and reduces
collection efficiency due to difficulties in charging the
particles. On the other hand, resistivities below 2x10*
ohm-cm make holding the particles on the plates difficult
and increase reentrainment problems. See Reference 9
for more information on low resistivity performance prob-
lems. In general, wet ESPs are much less sensitive to
particle resistivity than dry ESPs.
The particle resistivity is a fundamental indicator of the
drift velocity of the particles. The drift velocity is an
attempt to measure the velocity at which the particles
migrate to the collection plate, and is used in the basic
design equation presented below. The drift velocity
strongly influences the estimate of the collection plate
area for an ESP as can be seen in Equation 4.10-1.
For purposes of this manual, estimating the collection
plate area is the most important aspect of sizing an ESP.
A secondary consideration is the material of construc-
4-81
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tfon. For control of HAPs, ft is recommended that con-
tinuous monitoring of both plate voltage and current be
performed.
4.10.3.1 Collection Plate Area and Collection
Efficiency
Although precise specification of collection plate area is
best left to the vendor, an approximate collection plate
area can be calculated using the available drift velocity
value for the gas stream. For control of HAP emissions,
it is recommended that a more precise computer model
be used by the source or vendor to ascertain the re-
quired collection plate area. In the absence of this,
Equation 4.10-1 can provide an indication of required
plate area.
As noted earlier, collection plate area is a function of the
emission stream flow rate, the paniculate drift velocity,
and desired control efficiency. The Deutsch-Anderson
equation relates these variables as follows:1'2-7
SCA « -ln(1-CE)/Ud(0.06)
(4.10-1)
where:
SCA
CE
Ud
specific collection plate area, ft*/1,000
acfm
required collection efficiency, decimal
fraction
drift velocity of particles, ft/s
The value of SCA, the specific collection area, is the area
required per 1000 ft3/min. Thus, for a given application,
the SCA must be multiplied by the volumetric flow rate (in
units of 1,000 acfm) to obtain the total collecting plate
area. This equation estimates the required SCA for a
given collection efficiency. As the collection efficiency
increases, the SCA also increases, all otherthings being
equal.
Published data on drift velocities as a function of collec-
tion efficiency for a plate wire (dry and wet) and flat plate
ESPs are presented in Tables 4.10-1 through 4.10-3.
These tables may be used to obtain an indication of the
drift velocity if no other information is available. They
may also be used to serve as a check on drift velocity
values submitted by a source. If the emission stream
does not match any of the data presented in Tables 4,10-
1 through 4.10-3, or information from the source or a
vendor is unavailable, a defau It value of 0.30 ft/s may be
used for particles of "average" resistivity (approximately
2 x 10* to 2 x 1010 ohm-cm), and a value of 0.10 ft/s may
be used for particles having a high resistivity (1011 to 1013
ohm-cm).
A plot of Equation 4.10-1 in graphical form is presented
in Figure 4.10-1. This enables the reader to quickly
obtain an estimate of the SCA as a function of the
desired collection efficiency and the drift velocity of the
particles. This f igu re was obtained from Reference 7 and
uses a different nomenclature than Equation 4.10-1.
The variables p and w8 in Figure 4.10-1 correspond to
(1-CE) and Ud used in Equation 4.10-1, respectively.
As mentioned above, particles with tow resistivities are
difficult to collect and impose special design consider-
ations on an ESP. Such particles (resistivities from 10*
to 107 ohm-cm) are difficult to collect because the
particles tend to lose their charge, drop off the collector
plate and become reentrained in the gas stream. In such
cases, specially designed collecting plates or coatings
may be used to reduce reentrai nment as well as the use
of addftivies such as ammonia to the emission stream.1'2'7-9
Particles with high resistivities also can cause ESP
operating difficulties. High resistivity particles accumu-
late on the collection plates and insulate the collection
plate, thus reducing the attraction between the particles
and the collecting plate (i.e. back corona). In these
cases, oversizing an ESP and more frequent cleaning or
rapping of the collector plates are necessary. An alterna-
tive to a larger ESP is the use of conditioning agents to
reduce the resistivity of the particles. Consult a vendor
for advice concerning conditioning agents.
4.10.3.2 Materials of Construction
The most common material used in ESP construction is
carbon steel. In cases where the gas stream contains
high concentrations of SO3 or where liquid-gas contact
areas are involved, stainless steel may be required.1'2-3-4'5
However, by keeping the emission stream temperature
above the dew point and by insulating the ESP (the
temperature drop across an insulated ESP should not
exceed 20°F) the use of stainless steel should not be
necessary.
4.70.4 Evaluation of Permit Application
Using Table 4.10-4, compare the results from this sec-
tion and the data supplied by the permit applicant. The
calculated values are based on the example. In evaluat-
ing the reasonableness of ESP design specifications in
a permit application, the main task will be to examine
each parameter in terms of its compatibility with the gas
stream conditions.
4-82
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Table 4.10-1. Plale-wiro ESP DMR Velocities (Way
Partide Source
Design Efficiency, %
95
99
99.5
99.9
Bituminous coal fly ash11
Sub-bituminous coal fly ash in
tangential-fired boiler"
Other coal1'
Cement Win"
Glass plant"
Iron/steel sinter plant dust with
mechanical precollector"
Kraft-paper recovery boiler1'
Incinerator fly ash*
Copper reverberatory furnace*
Copper converter9
Copper roaster11
Coke plant combustion stack1
(no BC)
. (BC)
(noBC)
(BC)
(no BC)
(BC)
(noBC)
(BC)
(noBC)
(BC)
(no BC)
(BC)
(noBC)
(noBC)
(no BC)
(no BC)
(noBC)
(no BC)
0.41
0.100
0.56
0.151
0.32
0.095
0.049
0.020
0.052
0.016
0.223
0.072
0.085
6.502
0.203
0,180
0.203
0.039 i
0.33
0.080
0.39
0.102
0.26
0.072
0.049
0.020
0.052
0.016
0.200
0.050
0.082
0.374
0.138
0.144
0.180
—
, 0.31
0.078
0.34
0.085
0.26
0.069
0.059
0.016
0.050
0.016
. 0.216
0.050
0.102
0.348
0.121
0.134
0,174
_
0.27
0.069
0.29
0.072
0.24
0.062
0.059
0.016
0.050
0.016
0.207
0.056
0.095
0.308
0.276
0.118
0.157
_
BC - Back corona. ' .
« Reference 7. To convert ft/s to em/s, multiply ft/s by 30.488. f
* At 300°F. Depending on individual furnace/boiler conditions, chemical nature of the fly ash, and availability of naturally occurring conditioning
agents (e.g., moisture in the gas stream) migration velocities may vary considerably from these values. Likely values are In the range from back
corona to no back corona.
" At600°F. dAt5000F. BAt250°F. '450to570°F. .
' 500to700t>F. " 600 to 660°F. l360to450°F.
< Data available only for inlet concentrations in the range of 0.02 to 0.2 g/s-m3 and for efficiencies less than 90 percent
Table 4.10-2. Wet Plate-Wire ESP Drift Velocities (tt/s)°
Design Efficiency, %
Particle Source"
Bituminous
coal fly ash
Sub-bituminous
coal fly ash in
tangential-fired
boiler
Other coal
Cement kiln
Glass plant
Iron/steel sinter
plant dust with
mechanical
precollector
95
1.03
1.31
0.692
0.210
0.151
0.459
99
1.08
1.40
0.702
0.184
0.148
0.449
99.5
0.817
1.45
0.705
0.164
0.141
0.436
99.9
0.269
1.03
0.558
0.187
0.125
0.380
Reference 7. To convert ft/s to cm/s, multiply ft/s by 30.488.
Table 4.10-3. Flat Plata ESP Drift Velocities, ft/s
(No back corona )•
Design Efficiency, %
Particle Source
Bituminous
coal fly ash*
Sub-bituminous
coal fly ash in
tangential-fired
boiler"
Other coal"
Cement Win*
Glass plant"
Iron/steel sinter
plant dust with
mechanical
precollector6
Kraft-paper
recovery boiler*
Incinerator fly ash"
95
0.309
0.670
0.494
0.150
0.108
0.328
0.117
0.590
99
0.354
0.426
0.501
0.105
0.105
0.321
0.110
0.396
99.5
0.436
0.497
0.504
0.101
0.101
6.312
0.143
0.494
99.9
0.375
0.415
0.133
0.089
0.089
0.272
0.136
0.429
Reference 7. To convert ft/s to cm/s, multiply ft/s by 30.488.
At SOOT.
At600°F.
At500°F.
At250°F.
4-83
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99.9
50
100
150
200
,250 300 350 400 450 500 550
Square Feet Collacting Electrode per 1,000 ftVmin
650 700
Where: SCA «• specific collection area; p - fractional penetration, or p = 1 - fractional efficiency; we = migration velocity
To get SCA hi fP/1,000 acfm, multiply we in cm/s by 0.00197 (in ft/s by 0.0600).
Figure 4.10-1. Chart for finding SCA.7
If the applicant's collection plate area is different than
the calculated area, the discrepancy will most likely be
the selected drift velocity. Further discussions with the
permit applicant are recommended to evaluate the de-
sign assumptions and to reconcile any apparent dis-
crepancies.
Table 4.10-4. Comparison of Calculated Values and Values
Supplied by the Permit Applicant for ESPs
Parameter
Continuous monitoring
of plate voltage and current
Drift velocity
of particles, Ud
Collection efficiency, CE
Collection plate area, A,,
Calculated
Value1
yes
0.31
0.999
40,800 ft2
Reported
Value
' Based on the municipal incinerator emission stream.
4.10.5 Determination of ESP Operating Parameters
Many times, optimization of an ESPs collection effi-
ciency occurs in the field after construction. The follow-
ing discussion does not pertain to the preliminary design
of an ESP control system. Therefore, this discussion is
placed afterthe evaluation of the permit application. The
information presented should be helpful in achieving
and maintaining the desired collection efficiency for the
installed control system.
4.10.5.1 Electric Field Strength
Current in the form of ions from the charging electrodes
actually charge the particles. Once the particles are
charged, the electric field strength determines the amount
of charge on the particles.
Field strength is based on voltage and distance between
the collecting plates and electrodes.1'2-3 ESPs are usu-
ally operated at the highest secondary voltage practi-
cable with limited sparking to maximize collection
efficiency. Sparking represents an instantaneous drop
in voltage, collapse of the electrostatic field, and mo-
mentary cessation of paniculate collection. Sparking
varies with the density of the gas stream, material
collected on the electrodes, and humidity and tempera-
ture of the gas stream. When automatic controls are
used, ESPs usually operate with a small amount of
sparking to ensure that the voltage is in the correct range
and the field strength is maximized. Automatic voltage
controls can control sparking to a specified sparking
frequency (typically 50 to 150 sparks per minute per
section of ESP).2 As the spark rate increases, a greater
percentage of the input power is wasted in the spark
current. Consequently, less useful power is applied to
the collecting electrode.
4.10.5.2 Cleaning Frequency and Intensity
Particles accumulating on the collecting plates must be
removed periodically. In wet ESPs the liquid flowing
down the collector surface removes the particles.5 In dry
ESPs, the particles are removed by vibrating or rapping
the collector plates. For dry ESPs this is a critical step in
the overall performance because improperly adjusted or
operating rappers can cause reentrainment of collected
particles or sparking due to excessive particu late buildup
on the collection plates or discharge electrodes. In
normal operation, dust buildup of 6 to 25 mm is allowed
before rapping of a given intensity is initiated.1 In this
way, collected material falls off in large clumps that
would not be reentrained. If rapping is initiated more
4-84
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frequently or if the intensity of rapping is towered, the
resulting smaller clumps of paniculate matter are more
likely to be reentrained, reducing the collection effi-
ciency of the ESP. Optimal adjustment of the ESP can
best be made by direct visual inspections through sight
ports.
4.10 J.3 ESP Collection Efficiency
ESP collection efficiencies less than permitted can be
the result of operational problems, mechanical troubles,
or improper design. Typical operational problems in-
clude improper electrical settings, badly adjusted rap-
pers, full or nearly full dust hoppers, and process upsets.
Mechanical difficulties typically are the result of elec-
trode misalignment or excessive dust buildup on the
electrodes. Basic design problems include undersized
equipment, reentrainment, or high resistivity particles.
The permit applicant should carefully examine each of
these items if the ESP is emitting particulate emissions
from his facility that are in excess of permitted levels.
4.10.6 Capital and Annual Costs of ESP Systems
This section provides a methodology to estimate the
total capital and annual costs for an ESP.
4.10.6.1 ESP Capital Costs
The capital costs consist of equipment costs (including
auxiliary equipment) and the direct and indirect costs
associated with installing or erecting the ESP. The
equipment cost for five types of ESPs are given in 2nd
quarter 1987 dollars. While these, costs may appear
somewhat dated, costs for ESP systems have risen little
in the past ten years due to more effective designs and
more vendor competition. Therefore, assume these
costs are current and do not need to be escalated. If
needed, Table 4.12-1 can be used to escalate these
costs. The ESP types include plate wire, flat plate, wet,
tubular and two-stage. The capital cost direct and indi-
rect installation factors for ESP systems are provided in
Table 4.10-5. Equipment cost multipliers for standard
options supplied with some ESPs are provided in Table
4.10-6.
The structure cost is primarily a function of plate area,
but electrode design and materials of construction can
also influence this value. Table 4.10-7 provides equip-
ment cost multipliers for various materials of construc-
tion.
The flange-to-flange equipment cost of flat wire rigid
electrode and flat plate ESP systems are given in Figure
4.10-2, as a function.of the collection plate area.
In Rgure 4.10-2, the reader should be aware that the
upper and lower lines are simply aids in obtaining more
precise estimates of costs with the formulae rather than
the rougher estimate obtained from reading the curves
directly. The black bars simply indicate the point at which
the slopes change (50,000 ft2). Therefore, the second
line from the top is the curve for ESP systems with all
standard options while the second line from the bottom
is for basic ESP systems without standard options.
The cost of wet and tubular ESPs are more difficult to
estimate because the market is relatively small. In
general, flange-to-flange equipment costs of $65 - $957
ft2 of collection area can be used as a rough estimate for
wet ESPs, while $90 - $120/ft of collection area is a
typical cost for wet tubular ESPs.7
Table 4.10-5. Capital Cost Factors for ESPs*
Cost Item
Factor
Direct Costs
Purchased Equipment Costs
ESP + auxiliary equipment, EC
Instrumentation
Sales taxes
Freight
Purchased Equipment Cost, PEC
, Direct Installation Costs
Foundations & supports
Handling & erection
Electrical
Piping
Insulation for ductwork*
Painting
Direct Installation Cost
Site preparation
Buildings
Total Direct Cost, DC
Indirect Costs (installation)
Engineering
Construction and field expenses
Contactor fees
Start-up
Performance test
Model study
Contingencies
Total Indirect Cost, 1C
Total Capital Cost = DC + 1C
As estimated, EC
0.10 EC
0.03 EG
0.05 EC
PEC-1.18 EC
0.04 PEC
0.50 PEC
0.08 PEC
0.01 PEC
0.02 PEC
0.02PEC
0.67 PEC
As required, SP
As required, Bldg.
1.67 PEC +SP + Bldg,
0.20 PEC
0.20 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.02 PEC
0.03 PEC
0.57 PEC
2.24 PEC + SP + Bldg.
• Reference 7.
b If ductwork dimensions established, cost may be estimated based on
$10-$ 12/ft= of surface for field application. Fan housing and stacks
may also be insulated.
Table 4.10-6. Equipment Cost Multipliers for ESP Optional
Equipment*
Option
Factor
Inlet and outlet nozzles
and diffuser plates
Hopper auxiliaries/
heaters, level detectors
Weather enclosure and
stair access
Structural supports
Insulation
8-10 percent of ESP cost?
8-10 percent of ESP cost*
8-10 percent of ESP cosf1
5 percent of ESP cost6
8-10 percent of ESP cost*
»Reference 7.
* The ESP cost is the cost obtained from Figure 4.10-2.
Note that the upper curve in Figure 4.10-2 contains all above
standard options.
4-85
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Table 4,10-7. Equipment Cost Multipliers for Various Materials
of Construction*41
Material
Carbon Steel
304 Stainless Steel
316 Stainless Steel
Carpenter 20 CB-20
Monel-400
Nlckel-200
Titanium
Factor
1.0
1.3
1.7
2.5
3.0
4.2
5.8
• Reference 7.
k These (actors multiply the ESP cost obtained from Figure 4.10-2 or
4.10-3.
The flange-to-f lange structure cost for a two-stage ESP
system is given in Figure 4.10-3. The lower cost curve is
for a two-cell unit without a precooler, an installed cell
washer, or a fan. The upper curve is for a packaged
system with an inlet diffuser plenum, prefilter, cooling
coils with coating, coil plenums with access, water flow
controls, triple pass configuration, system exhaust fan,
outlet plenum, and in-place foam cleaning system.
The equipment cost (EC) for an ESP system is obtained
by adding the ESP structu re cost and the cost of auxiliary
equipment. Auxiliary equipment costs (refer to Section
4.12) include ductwork, dampers, fans, stacks, and
cyclones if necessary.
After obtaining the equipment cost, the purchased equip-
ment cost, PEC, is calculated based on the factors
provided in Table 4.10-5. The total capital cost is then
estimated according to the direct and indirect cost fac-
tors given In Table 4.10-5.
Example Case
Assume a basic flat plate rigid electrode ESP
system Is proposed. Figure 440-2 contains the
cost of this structure with a pFate area of 40,800 ft*
as$47Q,000 (from readingthe graph). For example
purposes, assume 304L stainless steel is used,
although ft probab^ is not necessary provided the
emisstanstream temperature is within 50 *,100°Fof
its dewpolnt From Table 4.10-7, the cost factor for
this material Is 1,3. This factor multiplies the cost'
from Figure 440-2, yielding 'a'cost of $611,000.
Assume auxiliary equipment costs equal$10,000.
The equipment cost (EC) Jslhen $621,000.
Table 4.10-5 te used to obtain the purchased equip*
ment cost (PEC) of the ESP system;
Instrumentation »0.10{£G)
Sales tax « 0.03 (EC)
Freight =0.05 (£0)
& $ 62,100
*$ 18,600
• $ 01,100
" $412,000
The purchased equipment cost'(PEC) is therefore
equal to $733*000. Table 4,10^5'is then used to
obtain the total capital cost, TCC. These costs are
given in Table 4.10-8. ° ; * • ,
4.10.6.2 ESP Annual Costs
The total annual cost of an ESP system consists of direct
and indirect annual costs. The appropriate cost factors
used to estimate this cost are provided in Table 4. 1 0-9.
The discussion below focuses on the information neces-
sary to correctly use these factors.
Direct Annual Cost These costs include electricity,
operating labor, maintenance costs, plus water costs,
waste water treatment costs, and SO3 conditioning costs
if they apply to the same units.
Electricity costs are primarily associated with the fan
needed to move the gas through the ESP. Equation
4.10-2 can be used to obtain an estimate of the fan
power needed.assuming a fan-motor efficiency of 65
percent and fluid specific gravity of 1 .0:
= 1.81x10-*(Qe.a)(P)(HRS)
(4.10-2)
where:
Fp = fan power requirement, kWh/yr
QB,a = emission stream flow rate, acfm
P •» system pressure drop, in. H2O
HRS = annual operating hours, hr/yr
For wet ESPs the pump power (Pp) can be estimated
from Equation 4.10-3.
Pp = 0.746 (Qt,)(Z) (Sg) (HRS)/(3960n) (4.10-3)
where:
PP
QL
Z
S9
HRS
n
= Pump power requirement, kWh/yr
= Liquid flow rate, gal/min
= fluid head, ft
= specific gravity of fluid relative to
water at 77° F, 1 atm
= annual operating hours, hr/yr
= combined pump-motor efficiency,
fraction
The power requirement forTR sets and motor-driven or
electromagnetic rapper systems can be estimated from
Equation 4.10-4:
OP = 1.94 x 10^ (Ap) (HRS) (4.10-4)
where:
OP = annual ESP operating power, kWh/yr
Ap = collection plate area, ftz
HRS = annual operating hours, hr/yr
4-86
-------
8 1
-------
100 i
90
80
| 70
1 6°
vf SO
£ 40
o
O
30
£ 20
10
0
Packaged System
System without
Precooler, Installed
Cell Washer, or Fan
4 68 10
Flow Rate (1,000 aefni)
12
14
Figure 4,10-3. Cost of two-stage ESP structures.7
The annual maintenance labor cost is estimated from
Equation 4.10-5:
MC = 0.01 (PEC) + Labor cost (4.10-5)
where:
MC » annual maintenance cost, $/yr
PEC = llange-to-flange purchased equip-
ment cost, $
Labor cost = $4,125 if Ap < 50,000 ft2
» 0.0825 Ap> 50,000 ft2
where Ap - collection plate area, ft2
The cost of maintenance materials is taken as 1 percent
of the PEC.
Indirect Annual Costs. These costs include the capital
recovery cost, overhead, properly taxes, insurance and
administrative costs. The appropriate factors used to
estimate these costs, as a percentage of the total capital
cost (TCC), are provided in Table 4.10-9.
4-88
-------
Table 4.10-8, Example Case Capital Costs
Cost Item
Factor
Cost($)
Direct Costs
Purchased Equipment Costs
ESP + auxiliary equipment, EC
Instrumentation
Sales taxes
Freight
Purchased Equipment Cost, PEC
Direct (installation Costs
Foundations & supports
Handling & erection
Electrical
Piping
Insulation for ductwork
Painting
Direct Installation Cost
Site preparation
Buildings
As estimated, EC
0.10 EC
0.03 EC
0.05 EC
PEC = 1.18 EC$
0.04 PEC
0.50 PEC
0.08 PEC
0,01 PEC
0.02 PEC
0.02 PEC
0,67 PEC
As required, SP
As required, Bldg.
$621,000
62,100
18,600
31,100
733,000
$29,300
367,000
58,600
7,330
14,700
14,700
$432,000
Total Direct Cost, DC
Indirect Costs (installation)
Engineering
Construction and field expenses
Contractor fees
Start-up
Performance test
Model study
Contingencies
) Indirect Cost, 1C
Total Capital Cost = DC + 1C
1.67 PEC + SP + Bldg.
0.20 PEC
0.20 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.02 PEC
0.03 PEC
0.57 PEC
2.24 PEC + SP + Bidg.
$1,220,000
$147,000
147,000
73,300
7,330
7,330
14,700
22,000
$411^000
$1,640,000
Table 4.10-9. Annual Costs for ESPs*
Cost Item
Direct Annual Costs, DAC
Utilities
Electricity
Water
Operating Labor
Operator
Supervisor
Coordinator
Maintenance
Labor
Material
Waste Disposal Costs
Indirect Annual Costs, IAC
Overhead
Administrative
Property tax
Insurance
Capital recovery11
Total Annual Costs, TAG
Factor
$0.059/kWh
^.ZQ/IO3 gal
$12,96/hr
15% of operator labor
33% of operator labor
See Section 4,10.6.2
% of PEC
Variable (see
Section 4.10.6.2)
0.60 (Operating labor
+ maintenance
costs)
2%ofTCC
1%ofTCC
1% of TCC
0.1175(TCC)
DC + IC
• Reference 7.
11 Capital recovery factor is calculated as: !{1+i)"/(1-fl)'l-1
where: i = interest rate, 10 percent
n = equipment life, 20 years
4-89
-------
. , -;.,,,,,., ^. t',5555*;-.:-:;.-•:.;.. *»;***+?»**•* jnl*:-;->«'**'**W';.,%
- ^om^asGwsiasita
4.10.7 References
1. LIptak, B.G. Editor. Environmental Engineers'
Handbook. Volume II Air Pollution. Chilton Book
Company. Radnor, Pennsylvania. 1974.
2. U.S. EPA. Air Pollution Engineering Manual.
2nd Edition. AP-40 (NTIS PB 225132). May
1973.
3. U.S. EPA. A Manual of Electrostatic Precipitator
Technology, Part 1 - Fundamentals. APTD 0610
(NTIS PB 196380). August 1970.
4. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. Cincinnati, OH. EPA-
625/6-86-014 (NTIS PB91-228809). Septem-
ber 1986.
5. Perry, R.H, and D. Green, Editors. Perry's
Chemical Engineers' Handbook. Sixth Edition.
McGraw-Hill Book Company. New York, New
York. 1984.
6. The Electrostatic Precipitator Manual. The
Mcllvaine Company. Northbrook, IL. 1975.
7. U.S. EPA. OAQPS Control Cost Manual
(OCCM). 4th Edition, EPA 450/3-90-006 (NTIS
PB90-169954). January 1990.
8. U.S. EPA. Handbook: Guidance on Setting Per-
mit Conditions and Reporting Trial Burn Re-
sults. EPA625/6-89-019. Cincinnati OH, January
1989.
9. M.D. Durham, D.E. Rugg, R.G. Rhudy, EJ.
Pachaver. Low Resistivity Related ESP Perfor-
mance Problems in Dry Scrubbing Applica-
tions. Journal of Air and Waste Management
Association. Vol. 40, No. 1, Pittsburgh, PA,
January 1990.
4.11 Venturi Scrubbers
Venturi scrubbers are designed to serve as a control
device for applications requiring very high collection
efficiencies of particles generally between 0.5 to 5.0 um
in diameter. They employ gradually converging and then
diverging sections to clean an incoming gaseous stream.
The section connecting the converging and diverging
sections of the scrubber is called the throat. In general,
the longer the throat, the higher the collection efficiency
at a given pressure drop, provided the throat is not so
long that frictional losses become significant.1 Venturi
scrubbers are also available in variable throat designs
that allow adjustment to the throat velocity as a means
of modifying the pressure drop and efficiency.
Typically, a liquid (usually water) is introduced upstream
of the throat and flows down the converging sides into
the throat where it is atomized by the gaseous stream;
this method is called the "wetted approach." Alterna-
tively, the liquid can be injected into the throat itself by
use of nozzles directed at the throat; this approach is
called the "nonwetted approach."1 The nonwetted ap-
proach works well when a gas is already close to
saturation; however, this method requires that the liquid
be free of particles that could clog the nozzles. Where
inlet gases are hot and a significant amount of liquid
needs to be evaporated, the wetted approach is pre-
ferred.
Once the liquid is atomized, it begins to collect particles
from the gas impacting into the liquid as a result of the
difference in velocities of the gas stream and the atom-
ized droplets. As the mixture decelerates in the expand-
ing section, further impaction occurs causing the droplets
to agglomerate. Once the particles have been trapped
by the liquid, a separator (e.g. cyclone, demisters, swirl
vanes) can readily remove the scrubbing liquid from the
cleaned gas stream.
Another type of scrubber that has been successfully
installed in industrial applications is called a hydrpsonlc
scrubber. This type of scrubber is very efficient at
controlling fine (submicron) particles found in metal
fumes, and noxious gas. Literature data from vendors
indicates these scrubbers have the potential to control
submicron particulates to outlet emissions of 0.006 gr/
dscf, corrected to 7 percent O2.10 One type of hydrosonic
scrubber uses two subsonic nozzles in tandem with a
throat separating the nozzles to maximize turbulent
mixing and particle agglomerization. The first nozzle
section condenses vapors present in the emission stream,
removes the larger particles, and initiates smaller par-
ticle agglomerization. The second nozzle section col-
lects the smaller particles not collected in the first section.
A different type of hydrosonic scrubber utilizes a super-
sonic nozzle to agglomerate particles and a subsonic
nozzle and mixing section to collect fine particles and
noxious gas (SO2, H2S, NOX, etc.) While these types of
scrubbers are not as common as venturi scrubbers, they
are mentioned here to introduce the reader to these
devices. For more information, consult Reference 10.
4-90
-------
In recent years, venturi scrubbers have been increas-
ingly supplanted in favor of fabric filters or ESPs. The
reasons for this include BACT regulations, advances in
filters and cleaning methods resulting in wider applica-
tion of baghouses, reductions in rapping losses for
ESPs, and problems associated with wastewater gen-
eration for venturi scrubbers. Therefore, while venturi
scrubbers are stili a viable choice for paniculate control,
the likelihood of encountering a venturi scrubber on a
given permit application is decreasing. Because of this,
readily available cost information on venturi scrubbers
was dated. Therefore, purchase cost information has
been obtained directly from vendors.
Appendix C.11 provides a worksheet to record the
information obtained during the performance of the
venturi scrubber design procedures.
4.11.1 Data Required
The data necessary to perform the design steps consist
of the HAP emission stream characteristics previously
compiled oh the "HAP Emission Stream Data Forms,'1
and the required HAP control as determined by the
applicable regulations.
In the case of a permit review for a venturi scrubber, the
following data should be supplied by the applicant.
1. Reported pressure drop across venturi
in. H2Q
2. Performance curve applicable to the venturi
scrubber.
3. Reported collection efficiency _ %
4.11.2 Pretreatment of the Emission Stream
As discussed in Section 3.3.1, the temperature of the
emission stream should be within 50 to 1OQ°F above the
stream dew point. Procedures for determining the dew
point of an emission stream are provided in Appendix
B.1. If the emission stream temperature does not fall
within the stated range, pretreatment (i.e., emission
stream preheating or cooling) is necessary. Methods of
pretreatment are briefly discussed in Appendix B.3. If
pretreatment is performed, the emission stream charac-
teristics will be altered. The primary characteristic affect-
ing venturi scrubber design are the saturated gas flow
rate (Q8,s), which is a function of the emission stream
temperature (Te) and flow rate at actual conditions (Q8,a),
particle size, and throat velocity.1-11 Thus, if the tempera-
ture of the emission stream changes, changing the
actual flow rate, the saturated gas flow rate must be
based on the new actual flow rate. The calculation
method depends upon the type of pretreatment per-
formed; use appropriate standard industrial equations.
The use of pretreatment mechanical dust collectors may
also be appropriate, depending upon the amount of
large particles in the emission stream. Appendix B.3
further describes the use of mechanical dust collectors.
4.11.3 Venturi Scrubber Design Variables
To design a venturi scrubber, any one of three options
may be chosen: (1) rely on previous experience with an
analogous application, which is best for plants lacking
effluent data; (2) test a scrubber on the source itself; or
(3) collect sufficient data about source stream character-
istics, such as particle size distribution, flow rate, and
temperature, to utilize existing "performance curves" for
a given venturi scrubber. This section is concerned with
the third option. Thus, the most important consideration
becomes the pressure drop across the venturi. A sec-
ondary consideration is materials of construction.
4.11.3.1 Pressure Drop and Efficiency
Performance curves are typically logarithmic plots relat-
ing venturi collection efficiency, pressure drop, and
particle size.2-3-8'6 Collection (control) efficiency is usually
plotted versus pressure drop across the venturi for a
particle mean diameter (Dp). Figure 4.11-1 is a plot of
venturi scrubber pressure drops for a given collection
efficiency and particle mean diameter for venturi scrub-
bers manufactured by a specific vendor. Thus, if the
particle mean diameter for an emission stream and
required collection efficiency is known, the pressure
drop across the venturi can be estimated. Figure 4.11-
1 is representative of plots likely to be used by vendors,
and does not necessarily represent characteristics for all
venturi scrubbers.
A logarithmic relationship between pressure drop and
efficiency exists for a given particle size as shown in
Figure 4.11 -1. This type of figure usually takes the place
of design equations for venturi scrubbers, if a particle
distribution is known, the overall collection efficiency is
the weighted average of the collection efficiency for
each particle size.
Estimating the pressure drop gives an indication of
whether a venturi scrubber is a feasible control device
for a given stream. Venturi scrubbers are used in appli-
-------
99.9
99.8
99.5
99
98
97
96
1
95
90
80
70
60
50
40
30
20
10
Venturi Pressure Drop
(in. Hp)
I I 1
0,1
0.2
0.4 0.6 0.8 1.0
Size of Particles (Aerodynamic Mean Diam.),
3.0
4.0 5.0
Figure 4,11-1 Typical Venturi scrubber performance curve.
cations where pressure drops of between 10 and 80
inches of water gauge occur across the venturi. Venturi
scrubbers can operate at pressure drops higher than 80
inches; however, in general, a pressure drop exceeding
80 inches H2O Indicates that a venturi scrubber will have
difficulty collecting the particles1. Therefore, if the pres-
sure drop indicated on the performance curve is greater
than 80 inches H2O, assume that the venturi scrubber
cannot accomplish the desired control efficiency.
For control of HAPs, it is recommended that routine
maintenance of the nozzles, liquid pump, and visual
inspection of the throat be performed to maintain system
design performance."
Typical pressure dropsforventuriscrubbersforavariety
of applications are listed in Table 4.11-1. The pressure
drops are listed to provide general guidance to typical
values that occur in industry. The values are not meant
to supersede any specific information known, and given
application may have a pressure drop outside those
listed in Table 4.11-1.
4.11.3.2 Materials of Construction
Proper selection of the materials in constructing a ven-
turi scrubber ensures long-term operation with minimal
downtime for repair. The materials are generally chosen
based on the corrosive or erosive nature of the emission
stream, and to a lesser degree, the temperature of the
gas stream. For any given application, a vendor should
be contacted to ensure correct selection of materials. A
venturi scrubber will generally be constructed of either
carbon or stainless steel or a nickel alloy; it may also be
lined with another material (e.g., ceramics). Materials of
construction for various industries are listed in Table
4.11-2 and serve as a general guide rather than a
definitive statement on the types of materials used in
industry.
4-92
-------
4.11.4 Sizing of Venturi Scrubbers
If a venturi scrubber is found to be a feasible control
choice for a given emission stream, it is then sized.
Venturi scrubbers can be sized using either the flow rate
at inlet conditions (Qea) or the saturated gas flow rate
(Qe s).4 Vendors may use either parameter; the cost data
presented in Section 4.11.6 are based on Qa a. If needed,
Q, „ can be calculated as shown below. A ps'ychrpmetric
chart (Rgure 4.11-2) can be used to determine the
saturated gas temperature (Tea), and Qas can then be
calculated using Equation 4.11'-1:
X (Te,s + 460)/(Te + 460)
(4.1 1 -1)
where:
Qe.5
Ts,»
Te
Qw
where:
Q«.ad
De
LW.S
U,« =
Dw
saturated emission stream flow rate,
acfm
temperature of the saturated emission
stream, °F
temperature of emission stream at in-
let, °F
volume of water added, ft3/min. Qw can
be calculated from the following for-
mula:
Qw . - Q.,ad(D8)(Lw,s-Lw,a)(1/Dw)
actual flow rate of dry air, acfm
(Must account for air at stack conditions
of density and moisture. See example
case for application)
density of emission stream, Ibs/ft3
saturated Ib H2O/lb dry air (from psy-
chrometric chart)
inlet lbH2O/lb dry air (from psychromet-
ric chart)
density of water vapor, Ibs/ft3
The density of any gas can be approximated using the
following formula:
D -
(PM)/(RT)
where:
P
M
R
T
Table 4.11-1.
Application
pressure of emission stream, atm
molecular weight of gas, Ib/lb-mole
gas constant, 0.7302 atm fP/lb-moPR
temperature of gas, °R
Pressure Drops for Typical Venturi Scrubber
Applications*
Pressure drop
(In. H20)
Boilers
Pulverized coal
Stoker coal
Bark
Combination
Recovery
Incinerators
Sewage sludge
Liquid waste
Solid waste
Municipal
Pathological
Hospital
Kilns
Lime
Soda ash
Potassium chloride
Coal Processing
Dryers
Crushers
Dryers
General spray
Food spray
Fluid bed
Mining
Crushers •
Screens
Transfer points
Iron and steel
Cupolas
Arc furnaces
BOFs
Sand systems
Coke ovens
Blast furnaces
Open hearths
Nonferrous metals
Zinc smelters
Copper and brass
smelters
Sinter operations
Aluminum reduction
Phosphorus
Phosphoric add
Wet process
Furnace grade
Asphalt
Batch plants—dryer
Transfer points
Glass
Container
Plate
Borosilicate
Cement
Wet process kiln
Transfer points
15-40
10-12
6-10
10-15
30-40
18-20
50-55
10-20
10-20
10-20
15-25
20-40
30
25
6-20
20-60
20-30
20-30
6-20
6-20
6-20
30-50
30-50
40-60
10
10
20-30
20-30
20-50
20-50
20
50
10-30
40-80
10-15
6-10
25-60
25-60
30-60
10-15
6-12
' Reference 1.
4-93
-------
Table 4.11-2. Construction Materials for Typical Venturl
Scrubber Applications*
Construction
Application Material
Bailors
Pulverized coal
Stoker coal
Bark
Combination
Recovery
Incinerators
Sewage sludge
Liquid waste
Solid waste
Municipal
Pathological
Hospital
Kins
Ume
Soda ash
Potassium chloride
Coat Processing
Dryers
Crushers
Dtyars
General spray dryer
Food spray dryer
Fluid bed dryer
Mining
Crushers
Screens
Transfer points
Iron and Steel
, Cupolas
Arc furnaces
BOFs
Sand systems
Coke ovens
Blast furnaces
Open hearths
Nonfamus Metals
Zinc smelters
Copper and brass smelters
Sinter operations
Aluminum reduction
Phosphorus
Phosphoric add
Wat process
Fu ranee grado
Asphalt
Batch plants - dryer
Transfer points
Glass
Container
Plata
Boroslllcate
Cement
Wet process kiln
Transfer points
316L stainless steel
316L stainless steel
Carbon steel
316L stainless steel
Carbon steel or
316L stainless steel
316L stainless steel
High nickel alloy
316L stainless steel
316L stainless steel
High nickel alloy
Carbon steel or
stainless steel
Carbon steel or
stainless steel
Carbon steel or
stainless steel
304 stainless steel or
316L stainless steel
Carbon steel
Carbon steel or
stainless steel
Food-grade stainless steel
Carbon steel or
stainless steel
Carbon steei
Carbon steel
Carbon steel
304-316L stainless steel
316L stainless steel
Carbon steel
(ceramic lined)
Carbon steel
Carbon steel
Carbon steel
(ceramic lined)
Carbon steel
(ceramic lined)
Stainless steel or
high nickel
Stainless steel or
high nickel
Stainless steel or
high nickel
High nickel
316L stainless steel
316L stainless steel
Stainless steel
Carbon steel
Stainless steel
Stainless steel
Stainless steel
Carbon steel or
stainless steel
Carbon steel
Reference 1.
4.11.5 Evaluation of Permit Application
Using Table 4.11 -3, compare the results of this section
and the data supplied by the permit applicant. The
calculated values in the table are based on the example.
Compare the estimated Py and the reported pressure
drop across the venturi, as supplied by the permit
applicant.
If the estimated and reported values differ, the differ-
ences may be due to the applicant's use of another
performance chart, or a discrepancy between the re-
quired and reported collection efficiencies. Discuss the
details of the design and operation of the system with the
applicant. If there are no differences between the esti-
mated and reported values for P, the design and
operation of the system can be considered appropriate
based on the assumptions employed in this manual.
4.11.6 Capital and Annual Costs for Venturi
Scrubbers
The capital costs of a venturi scrubber system consists
of purchased equipment costs and direct and indirect
installation costs. The annual costs consist of direct and
indirect annual costs.
4-94
-------
0.35
0.30
0.25
0.20
a 0.15
JB
' 3
0.1P
0.05
50
100
200 250 300
Temperature, °F
350
400 4SO
500
Figure 4.11-2. Psychrometric chart.
Table 4.11-3. Comparison of Calculated Values and Values
Supplied by the Permit Applicant for Venturl
Scrubbers*
Parameter
Calculated Value
(Example Case)
Reported
Value
1.0pm
0.899
Particle mean diameter, Dp
Collection Efficiency, CE
Pressure drop, P«
a Based on the municipal incinerator emission stream.
4.11.6.1 Capital Costs of Venturi Scrubbers
Recent equipment cost information on venturi scrubbers
was not available. Accordingly, vendor estimates of
venturi scrubber costs were obtained as af unction of the
emission stream flow rate7-8. These equipment costs are
detailed in Table 4.11-4. These costs include carbon
steel construction and instrumentation but do not in-
clude auxiliary costs, sales tax, or freight. Refer to
Section 4.12 to obtain auxiliary equipment costs which
include ductwork, damper, fan, stack, and cyclone (if
necessary) costs. If 304L stainless steel construction is
used, multiply the carbon steel cost by a factor of 2.3. If
316L stainless steel is used, multiply the carbon steel
cost by 3.2.12 To obtain capital costs, use the direct and
indirect installation cost factors taken from previous EPA
publications. These factors are provided in Table
4.11-5.
Table 4.11-4. Venturi Scrubber Equipment Costs*
Flow rate Venturi Scrubber Cost
(acfm) ($)
10,000 £QM< 50,000
50,000 SQMS 150,000
VSC=$7,250+0.585 (QM)
VSC = $11.1
* Carbon steel construction; includes cost of instrumentation.
References 7 and 8.
*>i:::??!»:%*:v::::i**:^
4-95
-------
Tabla 4.11-5, Capital Cost Factors for Venturl Scrubber*
Cost Item
Factor
Direct Costs, DC
Purchased Equipment Costs
Venturi scrubber + auxiliary equipment As estimated, EC
Instrumentation1* Included with EC
Sales tax 0.03 EC
Freight 0.05 EC
Purchased Equipment Cost, PEC 1.08 EC
Direct Installation Costs
Foundation and supports
Erection and handling
Electrical
Piping
Insulation
Painting
Site preparation
Buildings
Total Direct Costs
Indirect Coste, 1C
Engineering
Construction
Contractor fee
Startup
Performance test
Contingency
Total Indirect Cost, 1C
Total Capital Costs
0.06 PEC
0.40 PEC
0.01 PEC
0.05 PEC
0.03 PEC
0.01 PEC
As required, SP
As required, Bldg.
1.56 PEC + SP + Bldg.
0.10 PEC
0.10 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.35 PEC
1.91PEC
a References 7 and 8.
b If not included with EC, estimate as 10 percent of the EC
4.11.6.2 Annual Costs for Venturl Scrubbers
The annual costs for venturi scrubber systems consist of
direct and indirect annual costs. Appropriate factor for
these costs are presented in Table 4.11-7.
Direct Annual Costs. Direct annual costs are composed
of utility costs (electricity and water), operating labor,
and maintenance costs. The costs of wastewater dis-
posal are beyond the scope of this manual.
Electricity costs are a function of the fan power required
to move the gas through the system. Equation 4.11 -2 is
used to estimate the fan power requirement assuming a
fan-motor efficiency of 65 percent and a fluid specific
gravity of 1.0.
F,
where:
p =1.81x10-4(Q.,a)(P)(HRS)
(4.11-2)
Q8,a
p
= fan power requirement, kWh/yr
= emission stream flow rate, acfm
= system pressure drop, in, H2O
HRS = system operating hours, yr
Tabl» 4.11-6. Example Case Capital Costs
Cost item
Factor
Cosl($)
Direct Costs, DC
Purchased Equipment Costs
Venturi scrubber & auxiliary equipment
Instrumentation
Sales tax
Freight
Purchased Equipment Cost, PEC
Direct Installation Costs
Foundation and supports
Erection and handing
Electrical
Piping
Insulation
Painting
Site Preparation
Building
Total Direct Cost, DC
Indirect Coste, 1C
Engineering
Construction
Contractor fee
Start-up
Performance test
Contingency
Total Indirect Cost, 1C
Total Capital Cost, TCC = DC + 1C
As estimated, EC
Included with EC
0.03 EC
0.05 EC
1.08 EC
0.06 PEC
0.40 PEC
0.01 PEC
0.05 PEC
0.03 PEC
0.01 PEC
0.56 PEC
As required, SP
As required, Bldg.
.56PEC
0.10 PEC
0.10 PEC
0.10 PEC
0.01 PEC
0.01 PEC
0.03 PEC
0.35 PEC
1.91 PEC
Bidg.
$223,000
6,690
$241,000
$14,500
96,400
2,400
12,000
7,200
2,400
$134,000
$375,000
$24,000
24,000
24,000
2,400
2,400
7,290
$84,000
$459,000+ SP+Bldg.
4-96
-------
Table 4.11-7, Annual Cost Factors tor Venturi Scrubbers*
Cost Item
Factor
Direct Annual Costs, DAG
Utilities
Electricity
Water
Operating Labor
Operator labor
Supervisory labor
Maintenance
Labor
Materials
Wastewater treatment
Indirect Annual Costs, IAC
-Overhead
Administrative
Insurance
Property tax
Capital recovery"
$0.059/kWh
$0.20/10* gal
$12.96/hr
15 percent of
operator labor
$14.26/hr
100 percent of
maintenance labor
Variable. Consult
source for specific
information
0.60 (Operating labor
+ maintenance)
2%ofTCC
1%ofTCC
1%ofTCC
0.1628 (TOO)
• Reference: 9
6 The capital recovery cost is estimated as: l{1 +i)"/(1+i)n -1
, where: I»»interest rate, 10 percent
n m equipment life, 10 years
The water consumption of a venturi scrubber is esti-
mated from Equation 4.11-3. This equation assumes
0.01 gal of water are required per acf of flow.
WR = 0.60 (Qe,a) HRS
(4.11-3)
where:
WR = water consumption, gal/yr
The amount of operator labor is estimated as 2 hours per
8 hour shift. The operator labor wage rate is provided in
Table 4.11-7. Supervisory costs are assumed to be 15
percent of operator labor costs.
The amou nt of maintenance labor is estimated as 1 hour
per 8 hour shift. The maintenance wage rate is provided
in Table 4.11-7. Maintenance materials are assumed to
equal maintenance costs.
The cost of waste water disposal ortreatment is variable
and not discussed here. Consult the source for an
estimate of this cost. Actual costs may be quite high.
Indirect Annual Costs. These costs consist of overhead
costs, administrative charges, property tax, and capital
recovery costs. Table 4.11 -7 provides appropriate fac-
tors for these costs.
4-97
-------
i Total
4.11.7 References
1. Cheremisinoff, P.N. and Young, R.A. Editors.
Air Pollution Control and Design Handbook:
Part 2. Marcel Dekker, Inc. New York, NY. 1977.
2. Liptak, B.G. Editor. Environmental Engineers'
Handbook. Volume II: Air Pollution. Chilton
Book Company. Radnor, Pennsylvania. 1974.
3. U.S. EPA. Wet Scrubber System Study, Vol-
ume I: Scrubber Handbook. EPA-R2-72-118a
(NTiS PB213016). August 1972.
4. U.S. EPA. The Cost Digest. Cost Summaries of
Selected Environmental Control Technologies.
EPA-600/8-84-010 (NTIS PB85-155695). Oc-
tober 1984.
5. U.S. EPA. Wet Scrubber Performance Model.
EPA 600/2-77-172 (NTIS PB271515).August
1977.
6. U.S. EPA. TI-59 Programmable Calculator Pro-
grams for Opacity, Venturi Scrubbers and Elec-
trostatic Precipitators. EPA-600/8-80-024 (NTIS
PB80-193147). May 1980.
7, Telecon and Fax. Sink, Michael, PES to
Borenstein, Murray, Air Pol Inc., Costs of Ven-
turi Scrubbers. January 5,1990.
8. Telecon and Fax. Sink, Michael, PES, to
O'Conner, Chris, American Air Filter. January 5,
1990.
9. U.S. EPA, OAQPS. Control Cost Manual. Fourth
Edition. EPA 450/3-90-006(NTIS PB90-
169954). January 1990.
10. John Zink Company. Technical Bulletins HSS
0003A and HSS 0004A and Technical Paper
7802A. Tulsa, OK 1988.
11, U.S. EPA. Handbook: Guidance on Setting Per-
mit Conditions and Reporting Trial Burn Re-
sults. EPA 625/6-86-019, January 1989.
12. U.S. EPA. Handbook: Control Technologies for
Hazardous Air Pollutants. (NTIS PB91-228809).
EPA 625/6-86-014. Cincinnati, OH.September
1986.
4.12 Costs of Auxiliary Equipment
For purposes of this handbook, auxiliary equipment is
defined to include the cost of fans, ductwork, stacks,
dampers, and cyclones (if necessary) which commonly
accompany control equipment. These costs must be
estimated before the purchased equipment cost (PEC)
can be calculated. Costs for auxiliary equipment were
obtained from Reference 1 .
If equipment costs must be escalated to the current year,
the Chemical Engineering (CE) equipment index2 can
be used. Monthly indices for five years are provided in
Table 4. 12-1.
4.12,1 Fan Purchase Cost
In general, fan costs are most closely correlated with
fan diameter. Equations 4. 12-1 through 4.1 2-3 can be
used to obtain fan prices. Costs for carbon steel fan
motor ranging in horsepower from 1 to 150 hp are
provided in Equations 4.12-4 and 4.12-5. Equations
4.12-2 or 4.12-3 are used in conjunction with Equa-
tions 4. 12-4 or 4. 12-5.
The cost of a fan is largely a function of the fan wheel
diameter, d(ar>. The wheel diameter is related to the
ductwork diameter through use of manufacturer's multi-
rating tables. The reader should be able to obtain the fan
wheel diameter for a given ductwork diameter by con-
sulting the appropriate multi-rating table, or by calling
the fan manufacturer.
For a centrifugal fan consisting of backward curved
blades including a belt driven motor and starter and a
static pressure range between 0.5 and 8 inches of water,
the cost as a function of fan diameter (dtan) in July 1988
dollars is provided by Equation 4.12-1.
Pfan = 42.3
(4.12-1)
where:
Pfan = cost of fan system, July 1988 $
dfan = fan diameter, in. (1 2.25" £ dfan < 36.5")
The cost of a fiber reinforced plastic (FRP) fan, not
including the cost of a motor or starter, is provided by
Equation 4.12-2. The cost of a motor and starter as
obtained in Equation 4.10-4 or 4.10-5 should be added
to the fan cost obtained in Equation 4.12-2.
= 53.7dtan1-38
(4.12-2)
where:
Pfan = cost of fan without motor or starter,
April 1988$
dfan = fan diameter, in (10.5" < d(an £ 73")
A correlation for a radial-tip fan with welded, carbon steel
construction, and an operating temperature limit of
4-98
-------
Table 4.12-1. CE Equipment Index*
Date
Index
Date
Index
Date
Index
Feb.
Jan.
Dec.
Nov.
Oct.
Sept.
Aug.
July
June
May
Apr.
Mar.
Feb.
Jan.
Dec.
Nov.
Oct.
Sept.
Aug.
July
June
1990
1990
1989
1989
1989
1989
1989
1989
1989
1989
1989
1989
1989
1989
1988
1988
1988
1988
1988
1988
1988
389.0
388.8
390.9
391.8
392.6
392.1
392.4
392.8
392.4
391.9
391.0
390.7
387.7
386.0
383.2
380.7
379.6
379.5
376,3
374.2
371.6
May
Apr.
Mar.
Feb.
Jan.
Dec.
Nov.
Oct.
Sept.
Aug.
July
June
May
Apr.
Mar.
Feb.
Jan.
Dec.
Nov.
Oct.
Sept.
1988
1988
1988
1988
1988
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1986
1986
1986
1986
369.5
369.4
364.0
363.7
362.8
357.2
3S3.8
352.2
343.8
344.7
343.9
340.4
340.0
338.3
337.9
336.9
336.0
335.7
335.6
335.8
336.6
Aug.
July
June
May
Apr.
Mar.
Feb.
Jan.
Dec.
Nov.
Oct
Sept.
Aug.
July
June
May
Apr.
Mar.
Feb.
Jan.
Dec.
1986
1986
1986
1986
1986
1986
1986
1986
1985
1985
1985
1985
1985
1985
1985
1985
1985
1985
1985
1985
1984
334.6
334.6
333.4
334.2
334.4
336.9
338.1
345.3
348.1
347.5
347.5
347.2
346.7
347.2
347.0
347.6
347.6
346.9
346.8
346.5
346.0
Reference 2.
1 ,000'F without a motor or starter is provided by Equa-
tion 4.12-3. The values for the parameters a and b are
provided by Table 4. 1 2-2:
Pfan =
Inn
(4.12-3)
where:
Pfan
a,,bf
dfan
= cost of fan without motor or starter,
July 1988$
= obtained from Table 4.12-2
«* fan diameter, in.
Table 4.12-2. Equation 4.12-3 Parameters
Parameter
Static pressure, in.
Flow rate, acfm
Fan wheel diameter, In.
•'•*
Group 1
2-22
700 - 27,000
19.125 - 50.5
6.41
1.81
Group 2
20-32
2,000 - 27,000
19.25 - 36.5
22.1
1.55
The cost of fan motors and starters is given in Equation
4.12-4 or 4.12-5 as a function of the horsepower (hp)
requirement. The cost obtained from either of these
equations should be added to the fan cost obtained in
Equation 4.12-2 or 4.12-3. For low horsepower require-
ments.
p _
"motor —
where:
(4.12-4)
= cost of fan motor, belt, and starter, Febru
ary1988$
hp = motor horsepower (1 < hp < 7.5}
For high horsepower requirements,
P -Q47hn°-s21
'motor — *"• * I 'P
where:
(4.12-5)
= cost of fan motor, belt and
starter, February 1988 $
hp = motor horsepower (7.5 < Hp 5
250)
4-99
-------
4. 72.2 Ductwork Purchase Cost
The cost of ductwork fora HAP control system is typically
a function of material (e.g., PVG, FRP), diameter and
length. To obtain the duct diameter requirement as a
function of the emission stream flow rate at actual
condition (Q,,«), use Equation 4.12-6. This equation
assumes a duct velocity (U^) of 2,000 ft/min.
12 [(4/te)(QM/U-«)]«
0.3028 (Q.,*)05
(4.12-6)
The cost of PVC ductwork in $/ft for diameters between
6 and 24 inches is provided in Equation 4.12-7.
PpVCD '•
where:
PPVCD
(4.12-7)
cost of PVC ductwork, $/ft (August
1988$)
duct diameter, in. (factor of 12 in/ft
above)
.,
1.98(14"<;dduct<24")
For FRP duct having a diameter between 2 and 5 feet,
Equation 4.12-8 can be used to obtain the ductwork cost.
Note that the duct diameter is in units of feet for this
equation.
PFRPD » 24
where:
(4.12-8)
PFRPD - cost of FRP ductwork, $/ft (August 1988 $)
Djjuoi * duct diameter, ft
It is more difficult to obtain ductwork costs for carbon
steel and stainless steel construction because ductwork
of this material is almost always custom fabricated. For
more information on these costs, consult Reference 1.
Let Q9. = 15,300':aelK:ffl|nf|^^
diameter, 0*^, is obtained;usirig'Equ1a1tiil!iifl2s6l!:il
' •" ::i'i':'''::::':t:;?::iiJis?slllli^^il^Biii
d**, » 0.3028 (15,3pOp
For a duct withiL*
applicable.
•s»»W::«S'ft: Vt^im&StSiKKiiifi-t&tK
* i tui^t iv^i «%/u"iwv/ii \jnjv*'V'y*-*? " P-V* Vlr1
equals 50 ($74.90)« $3j750lilii:i
n .._..-. •'^•••ywfx-i&ifxti.xt&.-x&m&i
4.12.3 Stack Purchase Cost
It is difficult to obtain stack cost correlations because
stacks are usually custom fabricated. Smallerstacks are
typically sections of straight ductwork with supports.
However, the cost of small (e.g., SO-100 feet) FRP
stacks can be roughly estimated as 150 percent of the
cost of FRP ductwork for the same diameter and length.
Similarly, the cost of small carbon steel and stainless
steel stacks is also approximately 150 percent of the
cost of corresponding ductwork (referto Reference 1 for
more information).
For larger stacks (200-600 feet) the cost is typically quite
high, ranging from $1,000,000 to $5,000,000 for some
applications. Equation 4.12-9 and Table 4.12-3 can be
used to obtain costs of large stacks.
Pate*'
where:
^
(4.12-9)
= total capital cost of large stack, 10e $
= stack height, ft
as,bs = refer to Table 4.12-3
Table 4.12-3. Parameters for Costs of Large Stacks"
Lining
Diameter (ft)
Carbon-steel
316-L SWnless
Steel In top
Section
Acid resistant
Firebrick
15
20
30
40
15
20
30
40
0.0120
0.0108
0.0114
0.0137
0.00602
0.00562
O.OOS51
0.00633
0.811
0.851
0.882
0.885
0.952
0.984
1.027
1.036
Reference 1.
m^m^^^mmimi^^mmmifiimmi&ss^m
l-x+&'jfc-i^\tt^iit:&*y4:&fX-:<'<:-'fa-&
4.12.4 Damper Purchase Cost
Dampers are commonly used to divert air flow in many
industrial systems. Two types of dampers are discussed
below: backflow and two-way diverter valve dampers.
The cost of backflow dampers for duct diameters be-
tween 10 and 36 inches is given in Equation 4.12-10.
(4.12-10)
= cost of damper, February 1988 $
= ductwork diameter, in.
where:
4-100
-------
The cost of a two-way diverter valve for ductwork diam-
eters between 13 and 40 inches are given in Equation
4.12-11.
P*ert-4.84ddu«1-50
where:
'
-------
-------
CAS Number
Appendix A.1
Listing of Compounds Currently Considered Hazardous*
HAP Name
CAS Number
HAP Name
83-32-9
208-96-8
75-07-0
64-19-7
108-24-7
67-64-1
75-05-8
74-86-2
60-78-2
107-02-8
79-06-1
79-10-7
107-13-1
15972-60-8
107-18-6
7429-90-5
133-90-4
92-67-1
504-29-0
7664-41-7
12124-97-9
12125-02-9
7783-20-2
628-63-7
62-53-3
120-12-7"
7440-36-0
1327-33-9
11097-69-1
7440-38-2
1303-28-2
1327-53-3
7784-42-1
1332-21-4
8052-42-4
1912-24-9
7440-39-3
10294-40-3
114-26-1
56-55-3
98-87-3
100-52-7
71-43-2
92-87-5
205-99-2
191-24-2
207-08-9
50-32-8
65-85-0
120-51-4
98-07-7
98-88-4
94-36-0
12-05-58
100-44-7
7440-41-7
92-52-4
80-05-7
7440-42-8
1303-86-2
10294-33-4
7637-07-2
7726-95-6
74-97-5
Acenaphthene
Acenaphthylene
Acetaldehyde
Acetic Acid
Acetic Anhydride
Acetone
Acetonitrile
Acetylene
Acety Isalicy lie Acid
Acrolein
Acrylamide
Acrylic Acid
Aerylonitrile
Alachlor
Aliyl Alcohol
Aluminum
Amiben
Amlnobiphenyl,4-
Aminopyridine,2-
Ammonia
Ammonium Bromide
Ammonium Chloride-Fume
Ammonium Sulfate
Amylaeetate,n-
Aniline
Anthracene
Antimony
Antimony Oxide
Aroclor 1 254
Arsenic and Compounds (as As)
Arsenic Pentoxide
Arsenic Trioxide
Arsine
Asbestos
Asphalt (Petroleum) Fumes
Atrazine
Barium
Barium Chromate
Baygon
Benz(a)Anthracene
Benzal Chloride
Benzaldehyde
Benzene
Benzidine
Benzo(b)Fiuoranthene
Benzo(ghl)Perylene
Benzo(k)Fluoranthene
Benzo(a)Pyrene
Benzole Acid
Benzoic Acid, Benzyl Ester
Benzotrichloride
Benzoyl Chloride
Benzoyl Peroxide
Benzyl Benzoate
Benzyl Chloride
Beryllium
Biphenyl
Bisphenol A
Boron
Boron Oxide
Boron Tribromide
Boron Trifluoride
Bromine
Brornochloromethane
106-99-0
106-97-8
109-79-5
78-93-3
1338-23-4
106-98-9
140-32-2
7t-36-3
85-68-7
123-86-4
105-46-4
540-88-5
141-32-2
78-92-2
75-65-0
109-73-9
128-37-0
2426-08-6
138-22-7
123-72-8
107-92-6
7440-43-9
10108-64-2
1306-19-0
2223-93-0
7440-70-2
1305-62-0
1305-78-8
76-22-2
105-60-2
133-06-2
63-25-2
1563-66-2
7440-44-0
1333-86-4
124-38-9
75-15-0
630-08-0
56-23-5
353-50^
120-80-9
7782-50-5
10049-04-4
79-11-8
108-90-70
75-45-6
53449-21-9
75-00-3
67-66-3
107-30-2
100-00-5
4-76-15-3
3691-35-8
75-29-6
107-05-1
2921-88-2
123-09-1
108-41-8
95-49-8
13907-45-4
68131-98-6
7738-94-5
13548-38-4
7440-47-3
Butadiene, 1 ,3-
Butane
Butaneihiol
Butanone,2-
Butanoneperoxide,2-
Butene,1-
ButylAcrylate
Butyl Alcohol
Butyl Benzyl Phthalate
Butytacetate.n-
Butylacetate.sec-
Butylacetate.tert-
Butylacrylate.n-
Butylalcohol.sec-
Buty!alcohol,t-
Butylamine.n-
Butylated Hydroxytoluene
Butylglycidylether,n-
Butyllactate.n-
Butyraldehyde
Butyric Acid
Cadmium
Cadmium Chloride
Cadmium Oxide
Cadmium Stearate
Calcium
Calcium Hydroxide
Calcium Oxide
Camphor, Synthetic
Caprolactam
Captan
Carbaryl
Carbofuran
Carbon
Carbon Black
Carbon Dioxide
Carbon Disulfide
Carbon Monoxide
Carbon Tetrachloride
Carbonyl Fluoride
Catechol
Chlorine
Chlorine Dioxide
Chloroacetic Acid
Chlorobenzene
Chlorodifluoromethane
Chlorodiphenyi
Chloroethane
Chloroform
Chloromethyl Methyl Ether, bis
Chloronitrobenzene,
Chloropentafluoroethane
Chlorophacinane
Chloropropane,2-
Chloropropene,3-
Chloropyrifos
Chlorothioanisole
Chlorotoluene.M-
Chlorotoluene,O-
Chrbmate, (Cr042*)
Chrome Tanned Cowhide
Chromic Acid
Chromic Nitrate
Chromium
1U.S. EPA, Shareef, G.S., M.T. Johnston, E.P. Epner, D. Ocamb, and C. Berry. Tutorial Manual for CAT (Controlling Air Toxics) Version 1,0.
EPA/600/8-88/092, August 1988,
A.1-1
-------
Appond!xA.1 (cant)
CAS Number HAP Nam*
CAS Number
HAP Name
18540-29-9 Chromium (VI) Compounds (as Cr)
1333-82-0 Chromium Oxide
14977-61 -8 Chromyl Chloride
7788-96-7 Chromyl Fluoride
218-01-9 Chrysene
8001-58-9 Coal Tar
8007-45-2 Coal Tar Pitch Volatiles
7440-48-4 Cobalt
1317-42-6 Cobalt Suiflde
7440-50-8 Copper
1317-38-0 Copper Oxide (CuO)
13071 -78-9 Counter 15 <3
1319-77-3 Cresol (All Isomers}
108-39-4 Cresol,m-
9S-48-7 Cresol.o-
106-44-5 Cresol.p.
8021-39-4 Creosote
14464-46-1 Crtotabalrte (SiOg)
123-73-9 Crotonaldehyde
98-82-8 Cumene
101-14-4 Curene
420-04-2 Cyanamlde
590-28-3 Cyanic Acid, Potassium Salt
917-61 -3 Cyanic Acid, Sodium Salt
57-12-5 Cyanide
143-33-9 Cyanides
506-68-3 Cyanogen Bromide
506-77-4 Cyanogen Chloride
110-82-7 Cyelohexane
108-93-0 Cyclohexanol
108-fl4-1 Cyclohexanone
110-83-8 Cyclohexene
542*92-7 Cyclopentadiene
112-31-2 Decanal
124-18-5 Decano
2238-07-5 di-2,3-Epoxypropyi Ether
84-74-2 di-n-Butyl Phthalate
117-84-0 dl-n-Octyl Phthalate
123-42-2 Diacetone Alcohol
39393-37-8 Dialkyl Phthalates
124-09-4 Diamlnohexane,1,6-
95-80-7 Diaminotoluene,2,4-
333-41-5 DIazinon
53-70-3 Dibenz(a,h)Anthrac8ne
19287-45-7 Diborane
96-12-8 Dibromochloropropane,1,2-,3-
95-50-1 Dlenlorobenzene,1,2"
91 -94-1 Dichtorobenzidine,3,3'-
110-56-5 Dichlorobuiane,1,4-
75-71-8 Dichlorodifluoromethane
75-34-3 Dichloroethane,1,1-
75-35-4 Dichloroethytene,1,1 -
540-59-0 Dlchloroethylene,! ,2-,Cis-,Trans-
156-60-5 DIchloroethylene,1,2-,Trans-
75-43-4 Dichloromonofluoromethane
594-72-9 D!chloronltroethane,1,1,1-
120-83-2 Dlchlorophenol,2,4-
94-75-7 Dichlorophenoxyacetic-aeid,2,4-
78-87-5 Dichloropropane,1,2-
542-75-6 DIch!oropropene,1,3-
77-73-6 Dlcyclopentadiene
111 -42-2 Dlethanolamlne
96-22-0 Dtethyl Ketone
84-66-2 DIethyl PhthalatB
109-89-7 DEethylamlne
100-37-4 Diethylaminoethanol
111 -46-6 Dtathylene Glycol
111-40-0 DIethylenetriamlne
108-83-8 Dlisobutyl Ketone
26761 -40-0 DiisodecyI Phthalate
109-87-5 Dimethoxymethane
127-19-5 Dimethyl Acet amide
115-10-6 Dimethyl Ether
131-11-3 Dimethyl Phthalate
77-78-1 Dimethyl Sulfate
75-18-3 Dimethyl Sulfide
124-40-3 Dimethylamlne
60-11 -7 Dimethylamlnoazobenzene,4-
1300-73-8 Dimethylami nobenze ne ,4-
121-69-7 Dimethylaniline,n,n-
68-12-2 Dimethylformamidejn.n-
123-91-1 Dioxane,1,4-
101 -84-8 Diphenyl Oxide
101-68-8 Diphenyl methane Dllsocyanate,4,4'-
1314-56-3 Diphosphorus Pentoxlde
110-98-5 Dipropylene Glycol
34590-94-8 Dipropylene Glycol Methyl Ether
64742-47-8 Distillates (Petroleum)
106-89-8 Epichlorohydrin
75-08-1 Ethanethion
64-17-5 Ethanol
110-80-5 Ethoxyethanol,2-
111-15-9 Ethoxyethylacetate,2-
141-78-6 Ethyl Acetate
140-88-5 Ethyl Acrylate (Inhibited)
541 -85-5 Ethyl Amyl Ketone
100-41-4 Ethyl Benzene
60-29-7 Ethyl Ether
759-94-9 Ethyldipropylcarbarnsthioat, s-
109-94-4 Ethyl Formate
78-10-4 Ethyl Silicate
74-85-1 Ethylene
106-93-4 Ethylene Dlbromide
107-06-2 Ethylene Dichloride
107-21-1 Ethylene Giycol
110-49-6 Ethylene Glycol Methyl Ether Acetate
111 -76-2 Ethylene Glycol yonobutyl Ether
75-21-8 Ethylene Oxide
107-15-3 Ethylenedlamine
151-56-4 Ethyleneimine
117-81-7 Ethylhexylphthatate,Bis,2-
16219-75-3 EtfiylIdene-2-Norbornene
12604-58-9 Ferrovanadium Dust
206-44-0 Fluoranthene
86-73-7 Ruorene
53-96-3 Fluorenylacetamide,n-,2-
16984-48-8 Fluorides
7782-41-4 Fluorine
75-69-4 Fluorotrichloromethane
50-00-0 Formaldehyde
75-12-7 Formamlde
64-18-6 Formic Acid
110-00-9 Furan
98-01-1 Furfural
98-00-0 Furfuryl Alcohol
110-17-8 FumarteAcid
8006-61-9 Gasoline
111 -30-8 Glutaraldehyde
56-8t -5 Glycerol
556-52-5 Glycldol
111-71-7 Heptanal
142-82-5 Heptane
87-68-3 Hexachloro-1,3- Butadiene
118-74-1 Hexaohlorobenzene
77-47-4 Hexachlorocyclopentadiene
34465-46-8 Hexachlorodibenzodioxin,1,2,3,6,7,8-
67-72-1 Hexachloroethane
684-16-2 Hexafluoroacetone
A.1-2
-------
Appendix A. 1 (cont)
CAS Number HAP Name
CAS Number
HAP Name
66-25-1 Hexanal
110-54-3 Hexane.n-
591-78-6 Hexanone,2-
142-92-7 Hexylacetate.sec-
107-41 -5 Hexylene Glyool
302-01-2 Hydrazine
122-66-7 Hydrazobenzene
7647-01-1 Hydrochloric Acid
10035-10-6 Hydrogen Bromide
7647-01-0 Hydrogen Chloride
74-90-8 Hydrogen Cyanide
7664-39-3 Hydrogen Fluoride
7722-84-1 Hydrogen Peroxide(30%)
7783-07-5 Hydrogen Selenide
7783-06-4 Hydogen Sulfide
123-31-9 Hydroqulnone
193-39-5 lndeno(1,2,3-o,d)Pyrene
7440-74-6 Indium
7553-56-2 Iodine
74-88-4 lodomethane
15438-31-0 Iron
1309-37-1 Iran Oxide Fume
123-92-2 Isoamyl Acetate
110-19-0 Isobutyl Acetate
78-83-1 Isobutyl Alcohol
78-84-2 Isobutyraldehyde
26952-21 -6 IsoOctyl Alcohol
78-59-1 Isophorone
78-79-5 Isoprene
67-63-0 Isopropanol
109-59-1 Isopropoxyethanol
108-21-4 Isopropyl Acetate
108-20-3 Isopropyl Ether
8001 -20-6 Kerosene
463-51-4 Ketene
301 -04-2 Lead Acetate
18454-12-1 Lead Chromate
1309-60-0 Lead Dioxide
7439-92-1 Lead Powder
8032-32-4 Ligroine
1310-65-2 Lithium Hydroxide
7433-95-4 Magnesium
1309-48-4 Magnesium Oxide
1309-48-8 Magnesium Oxide Fume
121-75-5 Malathion
108-31-6 Maieic Anhydride
7439-96-5 Manganese
104-14-4 Mboca
7725-93-1 Mereaptomethy!thiazolylmethy!ketone,2
7439-97-6 Mercury
141-79-7 Mesityl Oxide
79-41-4 MethacrylicAcid
74-93-1 Methanethiol
67-56-1 Meihanol
16752-77-5 Methomyl
72-43-5 Methoxychlor
109-86-4 Methoxyethanol,2-
79-20-9 Methyl Acetate
74-99-7 Methyl Acetylene
96-33-3 Methyl Acrylate
74-83-9 Methyl Bromide
78-78-4 Methyl Butane
74-87-3 Methyl Chloride
107-30-2 Methyl Chloromethyl Ether
8022-00-2 Methyl Demeton
624-92-0 Methyl Disulflde
107-31 -3 Methyl Formate
110-12-3 Methyl Isoamyl Ketone
624-83-9 Methyl Isocyanate
563-80-4 Methyl Isopropyl Ketone
74-94-1 Methyl Mereaptan
80-62-6 Methyl Methacrylate
110-43-0 Methyl n-Amyl Ketone
98-83-9 Methyl Styrene
78-94-4 Methyl Vinyl Ketone
137-05-3 Methyl-2-Cyanoacrylate
100-61-8 Methyianiline.n-
583-60-8 Methylcyclohexanone.o-
75-09-2 Methylene Chloride
101-77-9 Methylenedianiline,4,4'-
108-11 -2 Methylisobutylcarbin
108-10-1 Methylpentanone,4-,2-
872-50-4 Methylpyrrolidone,n-,2-
12001-26-2 Mica (VAN8C19CI)
7439-98-7 Molybdenum
108-90-7 Monochlorobenzene
141-43-5 Monoethanolamine
75-04-7 Monoethylamine
74-89-5 Monomethylamine
110-91-8 Morpholine
107-87-9 n-Methyl Propyl Ketone
684-93-5 n-Nitroso-n-Methylurea
62-75-9 n-Nitrosodimethytamine
8030-30-6 Naphtha
91 -20-3 Naphthalene
134-32-7 Naphthyiamine.1-
91 -59-8 Naphthylamine,2-
7440-02-2 Nickel
13463-39-3 Nickel Carbonyl
1313-99-1 Nickel Oxide
7440-02-0 Nickel Powder
7697-37-2 Nitric Acid
10102-43-9 Nitric Oxide
100-01-6 Nitroaniline.p-
98-95-3 Nitrobenzene
92-93-3 NHrodiphenyl,4-
79-24-3 Nltroethane
10102-44-0 Nitrogen Dioxide
55-63-0 Nitroglycerine
75-52-5 Nitromethane
100-02-7 Nitrophenol.p-
108-03-2 Nitropropane,1-
79-46-9 Nitropropane,2-
99-99-0 Nitrotoluene.p-
124-19-6 Nonanal
111-84-2 Nonane.n- .
3268-87-9 Octachlorodibenzo-p-Dioxin
124-13-0 Octanal
111-65-9 Octane
8012-95-1 Oil Mist, Mineral
1317-71-1 OlMne
144-62-7 Oxalic Acid (Anhydrous)
7783-41 -7 Oxygen Difluoride
10028-15-6 Ozone
106-51-4 p-Quinone
8002-74-2 Paraffin Wax Fume
87-86-5 Pentachlorophenol
504-60-9 Pentadiene Isomer
115-77-5 Pentaerythritol
109-66-0 Pentane
79-21 -0 Peraceflc Acid (40% Solution)
594-42-3 Perchloromethyl Mercaptan
7616-94-6 Perchtoryl Fluoride
64741 -88-4 Petro Distill (Heavy)
8002-05-9 Petroleum Distillates
85-01 -8 Phenanthrene
108-95-2 Phenol
122-60-1 Phenyl Glycidyl Ether
A.1-3
-------
Appendix A1 (cont)
CAS Number HAP Name
CAS Number
HAP Name
122-39-4 Phenylbenzenamine.n-
106-50-3 Phenylonediamine.p-
298-02-2 Phorate
75-44-5 Phosgene
7803-51-2 Phosphine
7664-38-2 Phosphoric Acid
7723-14-0 Phosphorous (Yellow)
10025-87-3 Phosphorous Oxychloride
7719-12-2 Phosphorous Trichloride
85-44-S PhthaiieAnhydride
88-89-1 Picric Acid
80-56-8 Pinene,a-
7440-06-4 Platinum
1336-36*3 Polychlorlnated Blphenyls
25322-69-4 Polypropylene Qlycol
8002-86-2 Polyvinyl Chloride Latex
7440-09-7 Potassium
7789-00-6 Potassium Chromate
151-50-8 Potassium Cyanide
7778-50-9 Potassium Dichramate
1310-58-3 Potassium Hydroxide
75-28-5 Propane, 2-Methyl-
1120-71 -4 Propane Sultone
57-55-6 Propanedio!,1,2-
57-57-8 Propioiacetone.b-
123-38-6 Proptenaldehyde
79-09-4 PropionicAcId
71-23-8 Propyl Alcohol
109-60-4 Propylacetate.n-
107-10-8 Propylamine
115-07-1 Propylene
6423-43-4 Propylene Glycol Dinitrate
107-98-2 Propylene Glycol Monomethyl Ether
75-56-9 Propylene Oxide
503-30-0 Propylene Oxide,1,3-
129-00-0 Pyrene
121-29-9 Pyrethrin
8003-34-7 Pyrethrum
110-86-1 Pyridine
14808-60-7 Quartz (Silica Dust)
91-22-5 Quinoltne
108-46-3 Resorcinol
10048-07-7 Rhodium Chloride
7782-49-2 Selenium Compounds (as Se)
7803-62-5 Silane
7631-86-9 Silica
60676-86-0 Silica Vitreous
7440-21-3 Silicon
409-21-2 Silicon Carbide
7440-22-4 Silver
7631-90-5 Sodium Bisulfate
10588-01-9 Sodium DIehromate
7681-49-4 Sodium Fluoride
1310-73-2 Sodium Hydroxide
7681-57-4 Sodium Matabisulfate
131-52-2 Sodium Pentaehloro-
10102-18-8 Sodium Selenlte
1302-67-6 Spinel
8052-41 -3 Stoddard Solvent
7789-06-2 Strontium Chromate
100-42-5 Styrene
7446-09-5 Suitor Dioxide
2551 -62-4 Sulfur Hexafluoride
10025-87-9 Suitor Monochioride
7446-11-9 Sulfur Trloxide
7664-93-9 SultorteAcid
14807-96-6 Talc
7727-43-7 Tbariumsuifate, Total Dust
13494-80-9 Tellerlum and Compounds (as Te)
26140-60-3 Terphenyl
75-65-1 t-Butyl Alcohol
634-66-2 Tetrachlorobenzene,1,2,3,4-
1746-01 -6 TetrachlorodibenzO"p-Dioxln,2,3,7,8-
76-12-0 Tetrachlorodifluoroethane.l.l ,2,2-,1,2-
79-34-5 Tetraehloroethane.1,1,2,2-
127-18-4 Tetrachloroethylene
3689-24-5 Tetraethyl Dithiopyrophosphate
78-00-2 Tetraethyl Lead
1320-37-2 Tetrafluorodichloroetiiane
109-99-9 Tetrahydrofuran
27813-21-4 Tetrahydropthalimlde
7722-88-5 Tetrasodium Pyrophosphate
7440-28-0 Thallium, Soluble Compounds (as Tl)
463-71-8 Thiophosgene
110-02-1 Thiophene
62-56-6 Thiourea
137-26-8 Thiram
7440-31-5 Tin(asSn)
13463-67-7 Titanium Dioxide
108-88-3 Toluene
26471-62-5 Toluene Diisocyanate
584-84-9 Toluene,2,4,Diisocyanat*
95-53-4 Toluidine.o-
126-73-8 Tributyl Phosphate
87-61 -6 Trichlorobenzene,1,2,3-
120-82-1 Trlchlorobenzene,1,2,4-
71-55-6 Trichloroethane,1,1,1-
79-00-5 Triehloroethane,1,1,2-
79-01 -6 Trichloroethylene
96-18-4 Trichloropropane, 1,2,3-
76-13-1 Trichlorotrifluoromethane, 1,1,2-
121-44-8 Triethylamine
75-63-8 Trffluormonobromomethane
1582-09-8 Trifluralin
552-30-7 Trimelliflc Anhydride
75-50-3 Trimethylamine
25551-13-7 Trimethylbenzene
58784-13-7 Trimethylphenyl n-Methyicarbamate
110-88-3 Trioxane,1,3,5-
115-86-6 Triphenyl Phosphate
7440-33-7 Tungsten and Compounds (as W)
8006-64-2 Turpentine
7440-61-1 Uranium
51-79-6 Urethane
7440-62-2 Vanadium
1314-62-1 Vanadium Pentoxide
62-73-7 Vapona
108-05-4 Vinyl Acetate
75-01-4 Vinyl Chloride
75-02-5 Vinyl Fluoride
25013-15-4 Vinyl Toluene
75-05-4 Vinylidene Chloride
1330-20-7 Xylene
108-38-3 Xyiene.m-
95-47-6 Xylene.o-
106-42-3 Xylene.p-
7440-65-5 Yttrium
7440-66-6 Zinc
7699-45-8 Zinc Bromide
7646-85-7 Zinc Chloride, Fume
13530-65-9 Zinc Chromate (as Cr)
1314-13-2 Zinc Oxide (Fume)
1314-84-7 Zinc Phosphide
13597-46-1 ZincSelenite
557-05-1 ZhicStearate
440-67-2 Zirconium Compounds (as Zr)
A.1-4
-------
Appendix A.2
Toxic Air Pollutant/Source Crosswalk
(Listing of Pollutants by SIC and SCC Classification)
SIC
SIC Coda Description
SCC Code
Associated Pollutants
01 AGRICULTURAL PRODUCTION CROPS
0111 Wheat
0112 Rice
0116 Soybeans
0119 Cash grains, nee
0133 Sugarcane and sugar beets
0174 Citrus fruits
018 Horticultural Specialties
0181 Ornamental nursery products
0182 Food crops grown under cover
0191 General farms, primarily crop
02 AGRICULTURAL PRODUCTION LIVESTOCK
0211 Beef cattle feedlots
0212 Beef cattle, except feedlots
Benzene, 1,2-Dichloro- (16); Benzene, 1,3-Dichloro- (16);
Benzene, 1,4-Dichloro- (16); Formaldehyde (26);
Kestrel (Pesticide} (16); Phenolsulfonic Adds (16)
2 Formaldehyde (26)
Carbon Tetrachloride (7); Ethane, 1,2-Dichloro- (8)
Carbon Tetrachloride (7); Ethane, 1,2-Dichloro- (8)
Carbon Tetrachloride (7); Ethane, 1,2-Dichloro- (8)
Ethane, 1,2-Dichloro- (8)
Biphenyl (27); Chlorine (27); Phenol, 2,4-Dichloro- (27);
Polycyclic Organic Matter (26); Sodium Hydroxide (27)
1-02-011-01 Polycydic Organic Matter (26)
Ammonia (27)
Ethane, 1,1,2-Trichloro- (28); Ethylene Oxide (21,22,28);
Thiram(22)
Hydrogen Sulfide (21,22,23,28)
, Ethane, 1,1,1 -Trichloro- (28); Polyvlnyl Chloride Latex (28)
Carbon Tetrachloride (7); Ethane, 1,2-Dichloro- (8)
Ethylene Oxide (15)
Ammonia (26); Ethane, 1,1,1-Trichloro- (28);
Polyvinyl Chloride Latex (28)
3-02-020-01 Ammonia (26)
Hydrogen Fluoride (21,22); Silica (22)
A.2-1
-------
Page Intentionally Blank
-------
Appendix A.3
Potential HAP's for Solvent Usage Operations
I
Aliphatic
Hydrocarbons
Aromatic
Hydrocarbons
Halogenated
Hydrocarbons
Alcohols
Glycols
Ethers
Epoxides
Phenols
CO
(B .£
~° a
Specific Compounds
Cyclohexane *
Generic Compounds
Stoddard solvent
Alicyclics »
Specific Compounds
Benzene * •
Toluene •
Xylenes * •
Napthalene11
Generic Compounds
Other aromalics"
Specific Compounds
Chloromethane11
Methylene chloride •
Chloroform11
Carbon tetrachloride • •
1 ,1 -dichloroethane
Trichloroethylene •
1,1,1-triehloroethane
Tetrachloroethylene *
Triehlorotrifluoroethane •
Chlorobenzene
o,p-Dichlorobenzene
Generic Compounds
Halogenated solvents *
Specific Compounds
Methanol
Ethylene glycol
Propylene oxide
Cresols
Phenol
Generic Compounds
Alcohols *
Glycols
Cellusolves
Ethers •
Phenols
Epoxides
Q 3> m 2j 5 *B °«) cs 93 'HI £•
3SC *• -/)"5"33O:3®C
1 1 1 % "I 1 1 .tfiltlfl
4J-=i.igli-£« ^Ll~,2B&U-..3
°£ & U> ^ 9" ^ 13 {g TO (0 c — ^ ^ h> *S
^0 * A ^ Jg ^ it u Q. 0j Uj ^" ^, ^ |^ %
O^Cfl U)V)(ACOIO(OC/}
-------
Ketones
Aldehydes
Esters
Amides
Participates
Acids
Nitriles
Heterocyctlc
Compounds
Miscellaneous
Trade Solvents
Specific Compounds
Formaldehyde
Acetaldehyde11
Furfural
Acetone
Acrolein (propenal)11
Methyl isobutyl ketone
Cyclohexanone
Generic Compounds
Aldehydes
Specific Compounds
Ethyl acetate
Generic Compounds
Amides
Nitrosamines
Specific Compounds
Cadmium
Chromium
Lead
Zinc
Specific Compounds
Nitrobenzene11
Generic Compounds
Organic acids
Nitriles
Nitrocompounds
Specific Compounds
Tetrahydrofuran
Furfural
Generic Compounds
Pyrrolidones
So Cal I + II
SolvessolOO + 150
Panasolve
Hi Sol 100
TenneooT-125
o> o o> a, aaS"mn2TM»'i
i & a S »3ls53^|l
i - °- •%. *fe n ^ ! m = 8 » i 1 1 i
t.ffllfllla ^^iffs^lg
1 1 1 ! 1 1 I 1 1 1 1 |i 1 1 * 1 i I 1
1 1 I 1 1 1 1 1 1 1 1 i I 1 1 1 1 1 1 1
*
* * ** ** * * **
• o • • • •** • • •
*
*
* • • • • •• ** **
*
*
• • * * • *
* • • • * *
• • * * * *
' * * * • * *
*
*
* *'
*
o
* *
*
*
*
A.3-2
-------
Appendix B.1
Gas Stream Parameters Calculations
At many plants, it is common that one pollution
control system serves several emission sources.
In such situations, the combined emission stream
parameters must be calculated from mass and
heat balances. Procedures for calculating the
combined emission stream and single emission
stream parameters listed below are provided in
this appendix.
8.1.1 Flow Rate and Temperature
B.1.2 Moisture Content, SOs Content, and Dew
Point
B.1.3 Particulate Matter Loading
B.1.4 Heat Content
B.1.1 Emission Stream Flow Rate And
Temperature Calculations
Only gas volumes at standard conditions (77°F, 1
aim) can be added together. Thus, volumes of all
gas streams must first be converted to volumes at
standard conditions. This calculation is shown be-
low. (Note: It is assumed that the emission
streams are approximately at atmospheric condi-
tions; therefore, pressure corrections are not nec-
essary.)
n , v 537
Ue1,a X
~ ^
Qe1
460+Te1
=Qe1
where:
Qei.a = flow rate of gas stream f 1 at ac-
tual conditions (acfm)
Tei = temperature of gas stream #1 (°F)
Qei = flow rate of gas stream #1 at stand-
ard conditions (scfm)
This calculation is repeated for each emission
stream which, when combined, will be served by
the control system. The total gas stream volumet-
ric flow rate at standard conditions (Qe) is calcu-
lated by adding all gas streams, as follows:
Qe1 + Qe2 + ... = Qe
where:
Qe = flow rate of combined gas stream
(scfm}
The temperature of the combined gas stream (Te)
must be calculated to convert this combined volu-
metric flow rate at standard conditions (Qe) to
actual conditions (Qe.a).
The temperature of the combined gas stream (T8)
is determined by first calculating the enthalpy
(sensible heat content) of each individual stream.
The calculation procedures are shown below.
where:
Tei = temperature of gas stream #1 (°F)
Hsi = sensible heat content of gas stream
#1 (Btu/min)
This calculation is repeated for each emission
stream. The total sensible heat is calculated as
follows:
Hsi + Hs2 + ... = Hs
where:
Hs= sensible heat of combined gas
stream (Btu/min)
The combined gas stream temperature (Te) is cal-
culated as follows:
ft3_Op
' v
_,
"s
— T
*
0.018Btil Qe
where: >
Te = temperature of combined gas
stream (°F)
The actual combined gas stream volumetric flow
rate at actual conditions (Qe,a) is then determined
as follows:
n v 460+Te -
Qe X -Qe,a
where:
Qe,a = flow rate of combined gas stream
at actual conditions (acfm)
B.1.2 Moisture Content, SOs Content, and
Dew Point Calculations
Moisture content is typically reported as a volume
percent. The calculation procedures require that
the volume percent moisture content of each
stream be converted to a Ib-mole basis, added
together, and then divided by the total combined
gas stream volumetric flow rate (Qe) to obtain the
moisture content of the combined gas stream. The
moisture content is calculated below both on a
volume percent and mass percent basis. The mass
basis is to allow for the dew point calculation.
The moisture content is converted from a volume
percent basis to a ib-mole basis as follows:
1 *, ~ ~ Ib-mole
where:
B.1-1
-------
Met » moisture content of gas stream #1
(% vol)
Mei.im * moisture content of gas stream
#1 (Ib-mole/min)
This calculation is repeated for each emission
stream to be combined. The moisture content is
the combined gas stream on a volume percent
basis (Me) is calculated by adding, as follows:
Me1,!m + MeZ.lm •*• — = Me,!m
29 Ib
392 scf Ib-mole
=DAe
where:
Me.im
Me =
= moisture content of combined
gas stream (Ib-mole/min)
moisture content of combined gas
stream (% vol)
The moisture content of the combined stream must
be reported on a mass basis (Me,m) to determine
the dew point. This is calculated as follows:
M y 18lb _,.
where:
Me.m - moisture content of combined gas
stream (Ib/min)
The amount of dry air in the combined gas stream
(DAe) is calculated as follows:
where:
DAe = dry air content of combined gas
stream (Ib/min)
Calculate the psychrometric ratio as follows:
Me,m/(DAe - M8,m) = psychrometric ratio
(Ib of water/lb dry
air)
Knowing the psychrometric ratio and the gas
stream temperature, the dew point temperature is
selected from Table B.1.1.
The presence of sulfur trioxide (SOs) in the gas
stream increases the dew point of the stream. If
the 80s component is ignored during the dew
point determination, condensation may occur
when not expected. In addition to the problems
associated with the entrainment of liquid droplets
in the gas stream, the SOs will combine with the
water droplets to form sulfuric acid, which causes
severe corrosion on metal surfaces and deteriora-
tion of many fabrics used in baghouses. There-
fore, the determination of the stream dew point
must consider the presence of SOs. With informa-
tion on the SOs content (ppm vol) and the moisture
content (% vol) of the gas stream, the "acid" dew
point temperature can be determined from Figure
B.1-1. Figure B.1-1. provides dew points for three
Table B.1-1. Daw Point Temperatures
Gas StreamTemperature (°F)
Psyehrometrlc
Ratio 70
0.000 0
O.OOS 54
0.010 62
0.015 68
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
0.060
0.065
0.070
0.075
0.080
0.085
0.090
0.095
80 90 100
Dew
000
58 61 65
65 68 71
72 75 77
77 80 82
85 87
89 91
95
98
120
140
160
180
200
220
240
Point Temperature (°F)
0
70
77
82
87
91
95
98
101
104
107
109
111
114
116
118
119
0
76
82
86
91
94
98
101
104
107
109
112
114
116
118
120
122
123
124
128
0
81
86
90
94
98
100
104
107
109
112
114
116
118
120
122
123
125
130
140
0
86
90
94
97
101
104
107
109
112
114
116
118
120
122
124
125
130
140
165
0
89
94
97
100
103
107
109
111
114
116
118
120
122
123
125
130
143
162
180
0
93
97
100
103
106
109
110
114
116
118
120
122
124
125
130
140
168
180
205
0
96
100
103
106
109
111
114
116
118
120
122
124
125
130
150
170
182
205
225
B.1-2
-------
moisture levels; however, dew points can be esti-
mated for other moisture values.
The SOa content of a combined gas stream is
calculated by first converting the SOa concentra-
tion of each individual stream to a Ib-moie (Im)
basis. The SOs content is calculated as follows:
where:
Sei = SOs content of gas stream #1 {ppm
vol)
Sei,im = SOs content of gas stream #1
(Ib-mole/min)
This is repeated for each separate gas stream.
These are then added to obtain the total SOs
content of the combined gas stream to the control
device as follows:
Se1,Im •*• Se2,Im -I- ... = Se.lm
~ 2scf
where:
Se.im = SOa content of combined gas
stream (Ib-mole/min)
Se - SOs content of combined gas
stream (ppm vol)
With information for the SOs content of the com-
bined gas stream (Se) and the moisture content of
the combined gas stream (Me), the acid dew point
is determined from Figure B.1-1 ,
B.I. 3 Paniculate Matter Loading
Paniculate matter concentrations usually are re-
ported in grains per acf. The procedures below
may be used to determine the paniculate loading
to a control device (in Ibs/hr) when gas streams
are combined.
lb :=Wei,.
hr
7,000gr
where:
Wei,g
particulate loading for gas
stream #1 (gr/acf)
Wei.i = paniculate loading for gas stream
#1 (Ib/hr)
This is repeated for each gas stream and the
results are added to obtain the paniculate loading
for the combined gas stream.
Wai. i -i- W.2,1 + ... = We,i
where:
We 1,1 = paniculate loading for combined
gas stream (Ib/hr)
10
120
200
140 160 180
Temperature °C
Figure B.1-1. "Acid" Daw Points in Stack Gases
The particulate loading of the combined gas
stream can be converted to a concentration as
follows:
lb
60 min Qe,a
where:
We,g - particulate loading for combined
gas stream (gr/acf)
B.1.4 Heat Content Calculation
The heat content of gas stream #1 (hei) can be
determined from the heat of combustion of its
components using the following equation:
n
he1 =(0.01) ]£ye1,l X hel.t
where:
hei = heat content in gas stream #1
(Btu/scf)
Yei.i « volume percent of component "i"
in gas stream #1 (% vol)
hei ,i = heat of combustion of component
T in gas stream #1: see Table
B.1 -2 (Btu/scf)
n = number of components in gas
stream #1
B.1-3
-------
The heat content of a combined emission stream
can be determined from the heat content of the
individual emission streams as follows:
where:
He
Yej
hej
m =
combined emission stream heat
content (Btu/scf)
vplu me percent of stream "f in com-
bined gas stream (% voi)
heat content of stream "j" in com-
bined gas stream: see previous dis-
cussion (Btu/scf)
number of individual gas streams in
combined gas stream
The heat content of a stream in Btu/scf can be
converted to Btu/lb by dividing the value in Btu/scf
by the density of the emission stream at standard
conditions (typically, 0.0739 Ib/ft3).
Table B.1.2. Hoats of Combustion and Lower Explosive
Limit {LEL) Data for Selected Compounds3
Compound
Methane
Etharo
Propane
n-Butane
Isobutane
n-Pentans
isopentane
Neopentane
n-Haxane
Ethylene
Propylene
n-Butane
!-Pentene
Benzene
Toluene
Xylene
Acetylene
Naphthalene
Methyl alcohol
Ethyl alcohol
Ammonia
Hydrogen sulfide
LEL
(ppmv)
50,000
30,000
21,000
16,000
18,000
15,000
14,000
14,000
11,000
27,000
20,000
16,000
15,000
13,000
12,000
11,000
25,000
9,000
67,000
33,000
160,000
40,000
Net Heat of
Combustion11'0
(Btu/scf)
882
1,588
2,274
2,956
2,947
3,640
3,631
3,616
4,324
1,472
2,114
2,825
3,511
3,527
4,196
1,877
1,397
5,537
751
1,419
356
583
"Sources: Steam/Its Generation and Use. The Babcock &
Wflcox Company, New York, NY. 1975
Ftre Hazard Properties of Flammable Liquids,
Gases, Volatile Sollds-1977, National Fire
Protection Association, Boston, MA. 1977.
bLowor heat of combustion.
"Based on 70°F and 1 aim.
Table B.1-3. Properties of Selected Organic Com*
pounds3
Compound
Acetone
Benzene
n-Butyl acetate
n-Butyl alcohol
Carbon tetrachloride
Chloroform
Cyclohexane
Ethyl acetate
Ethyl alcohol
Heptane
Hexane
Isobutyl alcohol
Isopropyl acetate
Isopropyl alcohol
Methyl acetate
Methyl alcohol
Methylene chloride
Methyl ethyl ketone
Methyl isobutyl ketone
Perchloroethylene
Toluene
Trichloroethylene
Trichlorotrifluoroethane
Xylene
Molecular
Weight
(Ib/lb-mole)
58
78
116
74
154
119
54
88
46
100
86
74
103
60
74
32
85
72
100
166
92
131
187
106
Boiling
Point
(°F)
133
176
257
243
170
142
176
171
173
209
156
225
191
181
135
148
104
17i
244
250
231
189
118
281-292
"Source: Chemical Engineer's Handbook, Perry, R.H. and
Chilton, C.H. (eds). Fifth Edition. McGraw-Hill
Book Company, New York, NY. 1973.
B.1-4
-------
Appendix B.2
Dilution Air Requirements
B.2.1 Dilution Air Calculations
The quantity of dilution air (Qd) needed to decrease the
heat content of the emission stream to hd is given by the
following equation;
where:
Qd
ha
hd
Q
= dilution air flow rate, scfm
= emission stream heat content before dilution,
Btu/scf
= emission stream heat content after dilution,
Btu/scf
«= emission streamf low rate before dilution, scfm
The concentrations of the various components and flow
rate of the emission stream have to be adjusted after
dilution as follows:
(2)
(3)
(4)
where:
CX,
QM. "
oxygen content of diluted emission stream,
vol%
moisture content of diluted emission stream,
vol%
flow rate of the diluted emission stream,
scfm
The factor 21 in Equation 2 denotes the volumetric
percentage of oxygen in air and the factor 2 in Equa-
tion 3 is the volumetric percentage of moisture in air at
70°F and 80 percent humidity. Calculations for the
moisture content are given for the readers' information,
but are not usually needed for the equations used in
this handbook.
After dilution, the HAP emission stream characteristics
are redesignated as follows:
02 - 0M
M8 ,= Med
l^e = nd
Q» = ex.,
. But/scf
scfm
Appendix C.2 is a worksheet for calculating dilution air
requirements.
B.2-1
-------
Page Intentionally Blank
-------
Appendix B.3
Gas Stream Conditioning Equipment
Gas conditioning equipment includes those
components that are used to temper or pretreat the
gas stream to provide the most efficient and
economical operation of the control device.
Preconditioning equipment, installed upstream of the
control device, consists of mechanical dust
collectors, wet or dry gas coolers, and gas
preheaters. Where the control device is a fabric filter
system or electrostatic precipitator, mechanical dust
collectors are required upstream if the gas stream
contains significant amounts of larger particles. Gas
cooling devices are used to reduce the temperature
of the gas stream to within the operating temperature
of the filter fabric, to reduce the volume of flue gas to
be treated, or to increase the HAP collection
efficiency. Gas preheaters are used to increase the
temperature of the gas stream to eliminate moisture
condensation problems. Gas conditioning equipment
is discussed below. Design procedures for gas
conditioning equipment are not included in this
manual. These procedures are straightforward and
readily available from vendors and common literature
sources.
B.3.1 Mechanical Collectors
Mechanical dust collectors, such as cyclones, are
used to remove the bulk of the heavier dust particles
from the gas stream. These devices operate by
separating the dust particles from the gas stream
through the use of centrifugal force. The efficiency of
a cyclone is determined by the entering gas velocity
and the diameter at the cyclone inlet. Theoretically,
the higher the velocity or the smaller the inlet
diameter, the greater the collection efficiency and
pressure drop. Cyclones remove the majority of dust
particles above 20 to 30 \im in size to reduce the
loading and wear on the subsequent control device.
In general, the particulate size distribution for the gas
stream will determine the need for a cyclone
collector. If the particle size distribution shows a
significant amount of particulate above 20 to 30 u.m
then use of an upstream cyclone is necessitated for
fabric filters and ESP's. "Wetted" venturi scrubbers
(see p. 4.11-1 for definition) do not generally
experience operating problems in collecting large (20
to 30 u.m) particles assuming correct scrubber design
and operation. Use of a pretreatment mechanical
dust collector may be necessary if a "nonwetted"
venturi scrubber (see p. 4-11.1 for definition) is used,
since this scrubbing method requires that the liquid
be free of particles that could clog the nozzles.
B.3.2 Gas Coolers
Gas coolers can be used to reduce the volume of the
gas stream or to maximize the collection of HAP's by
electrostatic precipitators and fabric filters. Venturi
scrubbers are less sensitive to high gas stream
temperatures, since the scrubber cools the gas prior
to particle collection. As the temperature of an
emission stream is decreased, the HAP's in vapor
form will also decrease. However, care must be
exercised so that the gas stream temperature does
not fall below the emission stream dew point. To
ensure a margin for error and process fluctuations,
the emission stream temperature should fall between
50 to 10Q°F above its dew point. Appendix B.1
presents procedures to determine an emission
stream's dew point.
Gas stream coolers can be wet or dry. Dry-type
coolers operate by radiating heat to the atmosphere.
Wet-type coolers (spray chambers) cool and
humidity the gas by the addition of water sprays in
the gas stream; the evaporating water reduces the
temperature of the gas stream. A third method of
cooling is through the addition of dilution air.
Selection of the type of gas cooling equipment to be
used in based on cost and dew point consideration.
For example, a wet-type cooler would not be
appropriate if cooling would increase the likelihood
of condensation within the fabric filter system.
If a gas cooler is used, a recalculation of the gas
stream parameters will have to be performed using
standard industrial equations. For instance, if wet-
type coolers are used, a new actual gas flow rate and
moisture content will have to be calculated.
B.3.3 Gas Preheaters
Gas preheaters are used to increase the emission
stream temperature. Condensation causes corrosion
of metal surfaces, and it is of particular concern in
fabric filter applications where moisture can cause
plugging, or "blinding", of the fabric pores; therefore,
gas preheaters can be used to elevate the
temperature of an emission stream above its dew
point. Methods commonly used to increase gas
temperature are direct-fired afterburners, heat
exchangers, and stream tracing. Afterburners are
devices in which an auxiliary fuel is used to produce
a flame that preheats a gas stream and that can also
combust organic constituents that might otherwise
blind the filter bags. Heat exchangers use a heated
gas stream in a shell-and-tube type arrangement to
preheat gases. With stream tracking, plants that
B.3-1
-------
have steam available tun gas lines inside the steam
lines to preheat the gases.
Emission streams containing HAP's should be
preheated only to 50 to 100°F above the dew point,
thus minimizing the vapor component of the HAP and
enabling a baghouse or an ESP to control the HAP
as effectively as possible. Appendix B.1 presents
procedures to determine an emission stream's dew
point.
If a gas preheater is used, a recalculation of the
stream parameters will have to be performed using
standard industrial equations. For example,
increased gas stream temperature will increase the
actual gas flow rate to be controlled.
B.3.4 References
1 Liptak, B.Q. Ed. Environmental Engineers'
Handbook, Volume II: Air Pollution. Chilton Book
Company. Radnor, Pennsylvania. 1974.
2 U.S. EPA. Handbook. Control Technologies for
Hazardous Air Pollutants. EPA 625/6-86-014.
September 1986. (NTIS PB91-228809).
B.3-2
-------
o
Appendix C.1
HAP EMISSION STREAM DATA FORM*
Cor" pa ny
I oration (Street)
(Pity)
(State, Zip)
A. Emission Stream Number/P
B. HAP Emission Source
C. Source Classification
D. Emission Stream HAP's
E, HAP Class and Form
F. HAP Content (1,2,3)**
G. HAP Vapor Pressure (1 ,2)
H. HAP Solubility (1,2)
I. HAP Adsorptive Prop. (1 ,2)
J, HAP Molecular Weight (1 ,2)
K. Moisture Content (1,2,3)
L, Temperature (1,5,3)
M. Flow Rate (1r2f3)
N, Pressure (1,5)
0. Haloqen/Metals(1,2)
Plant Pnntant
Telephone No
Anenr.v Hnntant
Nn nf Fmissin-n Streams I Jnrier Review
lant Identification
M
(a)
(*)
(a)
(a)
(a)
(a)
(a)
(b)
(b)
(b)
i1*/
(PJ
(h)
(b)
(h)
(b)
P. Organic Content (1)***
Q. Heat/02 Content (1)
R, Paniculate Pontent (3)
^ S. Particle Mean Diarn. (3)
T. Drift Velocitv/SO-, (3)
H
M
(c)
(c)
\w
(R)
/ni
(c)
U. Applicable Regulation(s)—
V. Required Control Level
W. Selected Control Methods
*The data presented are for an emission stream (single or combined streams) prior to entry into the selected control method(s),
. Use extra forms if additional space is necessary (e.g., more than three HAP's) and note this need.
**The numbers in parentheses denote what data should be supplied depending on the data in lines C and E:
1 = organic vapor process emission
2 = inorganic vapor process emission
3 = paniculate process emission
***0rganic emission stream combustibles less HAP combustibles shown on Lines D and F.
-------
Page Intentionally Blank
-------
Appendix C.2
Calculation Sheet for Dilution Air Requirements
Dilution air flow rate:
Qd = lOVhd)-1]Qe
Qd = _ scf m
Diluted emission stream characteristics:
02fd = 02 ( hd/he» + 21 [1 - ( hd/he)]
02/d = _ _ %
Me,d = Me ( hd/he) + 2 {1 - '( hd/he)]
Qe/d = Qe (h^ hd)
QM = - scf m
Redesignate emission stream characteristics:
O2 = O2(d = - _%
he = hd = _ Btu/scf
Qe = Qe>d = - scf m
(Note: The moisture content for incinerator calculations is not necessary.
It is provided for information purposes.)
C.2-1
-------
Page Intentionally Blank
-------
Appendix C.3
Calculation Sheet for Thermal Incineration
4.2.1* Data Required
HAP emission stream characteristics:8
1. Maximum flow rate, Qe = scfrn
2. Temperature, Te = °F
3. Heat content, he = Btu/scf
4. Oxygen content,13 ©2 = %
5. Halogenated organics: Yes , No
Required destruction efficiency, DE = %
In the case of a permit review, the following data should be supplied by the applicant:
Thermal incinerator system variables at standard conditions (77°F, 1 atm):
1. Reported destruction efficiency, DEreported = %
2. Temperature of emission stream entering the incinerator,
Te = . °F (if no heat recovery);
The = "F (if a heat exchanger is employed)
3. Combustion temperature, Tc = ' CF
4, Residence time, t r = sec
5. Maximum emission stream flow rate, Qe = scfm
alf dilution air is added to the emission stream upon exit from the process, the data required are
the resulting characteristics after dilution.
''The oxygen content depends on the oxygen content of the organic compounds (fixed oxygen)
and the free oxygen in the emission stream. Since emission streams treated by thermal
incineration are generally dilute VOC and air mixtures, the fixed oxygen in the organic
compounds can be neglected.
*Numbering in the remainder of Appendices C is provided to match numbering in the main text.
The only exception is for new material only (e.g. see page C.7-10 which has Table C.7-1). This
is intended to assist the reader in using the correct calculation formula.
C.3-1
-------
6. Fuel heating value, hf = Btu/lb (assume natural gas)
7. Combustion chamber volume, Vc = ft3
8. Flue gas flow rate, Qfg = scfm
4.2.2 Pretreatment of the Emissions Stream; Dilution Air Requirements
Typically, dilution will not be required. However, if the emission stream heat content (he) is greater
than 176 Btu/ib or 13 Btu/scf with an oxygen concentration less than 20 percent, see equation
4.2-1 or Appendix C.2 where a blank calculation sheet for determining dilution air requirements
is provided.
Qd = [(he/hd)-1]Qe 4.2-1
Qd = scf m
4.2.3 Design Variables, Destruction Efficiency, and Typical Operational Problems
Based on the required destruction efficiency (DE), select appropriate values for Tc and t r from
Table 4.2-2.
Tc = °F
tr = sec
For a permit evaluation, if the applicant's values for Tc and t r are sufficient to achieve the required
DE (compare the reported values with the values presented in Table 4.2-2), proceed with the
calculations. If the applicant's values for Tc and t r are not sufficient, the applicant's design is
unacceptable. The reviewer may then use the values for Tc and t r from Table 4.2-2.
t r = sec
(Note: If DE is less than 98 percent, obtain information from literature and incinerator vendors
to determine appropriate values for Tc and t r.)
4.2.4 Determination of Incinerator Operation Variables
4.2.4.1 Supplementary Fuel Requirements
To estimate the supplementary fuel flow rate, use equation 4.2-2.
De (Qe) [(Cpalr) (1.1 Tc - The - 0.1 (Tr) - he)] 4.2-2
^ Df[hf-1.1 Cpair(Tc-Tr)]
The values for the parameters in this equation can be determined as follows:
C.3-2
-------
Qe,he Input data.
De 0.0739 Ib/sef.
Df 0.0408 Ib/scf.
hf Assume a value of 21 ,600 Btu/ib if no other information is available,
Cpair See Table C.8-1 for values of Cpafr at various temperatures.
Tc Obtain value from Tabie 4.2-2 or from permit applicant.
The Use the following equation if the value for The is not specified:
The - (HR/1 00) T0 + [1 - (HR/1 00)] Te
where HR = heat recovery in the heat exchanger (percent). Assume
a value of 70 percent for HR if no other information is available.
Tr 77°F
Qf = _ scfm
4.2.4.2 Flue Gas Flow Rate
1 . For dilute emission streams, use Equation 4,2-3:
Qfg = Qe.+ Qf + Qd ..-'.''•-.. 4.2-3
where:
Qd is the dilution air value obtained from Appendix C.2.
scfm
4.2.4.3 Combustion Chamber Volume
a. Use Equation 4.2-4 to convert Qfg (standard conditions) to Qfg (actual
conditions):
Qfg,a - Qfg [(Tc + 460)/537] 4,2-4
Qfg,a = _ acfm
b. Use Equation 4.2-5 to calculate combustion chamber volume:
Ve = l(Qfg,a/60).trJ1.05 4.2-5
Obtain value for tr from Table 4.2-2 or from permit applicant.
C.3-3
-------
Vc = ft3
4.2.5 Evaluation of Permit Application
Compare the calculated values and reported values using Table 4.2-4. The combustion volume
(Vc) is calculated from flue gas flow rate (Qtg) and Qtg is determined by emission stream flow
rate (Qe), supplementary fuel flow rate (Of), and dilution air requirement (Qd). Therefore, if there
are differences between the calculated and reported values for Vc and Qfg, these are dependent
on the differences between the calculated and reported values for Qd and Qf.
If the calculated and reported values are different, the differences may be due to the assumptions
involved in the calculations. Discuss the details of the design and operation of the system with
the applicant.
If the calculated and reported values are not different, then the design and operation of the
system can be considered appropriate based on the assumptions employed in this handbook.
Table 4.2-4 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Thermal Incineration
Calculated Reported
Value Value
Continuous monitoring of combustion
temperature
Supplementary fuel flow rate, Qt
Dilution air flow rate, Qd
Flue gas flow rate, Qtg
Combustion chamber size, Vc
4.2.6 Capital and Annual Costs of Thermal Incinerators
4.2.6.1 Thermal Incinerator Capital Costs
Use the appropriate equation given in Table 4.2-5 to obtain the thermal incinerator cost, TC.
C.3-4
-------
Use the factors given In Table 4.2-6 and the auxiliary equipment cost provided in Section 4.12
to obtain the purchased equipment cost, PEC.
PEC = TC + Auxiliary equipment + Sales tax + Freight
PEC = $ - . "
After estimating the PEC, simply use the factors given in Table 4.2-7 to obtain the total capital
cost (TCC) estimate.
TCC-1.61 PEC + SP + Bldg.
TCC = $ . , •••
4.2.6.2 Thermal Incinerator Total Annual Costs, TAC
The TAC consist of direct and indirect annual costs. Direct annual costs include fuel, electricity,
operating and supervisory labor, and maintenance labor and materials. Indirect annual costs
include overhead, administrative, property taxes, insurance, and capital recovery costs.
Direct Annual Costs
1. Fuel usage
The fuel usage is calculated in Section 4.2.4.1. Take this quantity (in scfm) and
multiply by 60 to obtain scfh and multiply this by the annual operating hours and the
fuel cost.
Annual fuel cost = Of x 60 x HRS x $3.30/1,000 ft3
Annual fuel cost = $ •
2. Electricity costs,
Use Equation 4.2-6 to estimate the fan power requirement, Fp
Fp = 1.81 x 10"4 (Qfg)(P)(HRS)
Fp = kWh/yr
Electricity costs = $0.059 (Fp)
Electricity costs = $
3. Operating costs
Operating labor costs = [{0.5 hr/shift)/(8 hr/shift)](HRS)($12.98/hr)
Operating labor costs = $
C.3-5
-------
Supervisory costs = 0.15 (Operating labor costs)
Supervisory costs = $
4. Maintenance costs
Maintenance labor costs = [(0.5 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)
Maintenance labor costs = $
Maintenance materials =1.0 (Maintenance labor costs)
Maintenance materials = $
Total Direct Costs = $
Indirect Annual Costs
These costs are obtained from factors given in Table 4.2-7.
Overhead = $
Administrative =$____
Property taxes = $ '
Insurance = $
Capital recovery = $
Total Indirect Costs = $
Total Annual Costs = Total Direct Costs + Total Indirect Costs
Total Annual Costs = $
C.3-6
-------
Appendix C.4
Calculation Sheet for Catalytic Incineration
4,3.1 Data Required
HAP emission stream characteristics:8
1 . Maximum flow rate, Qe = _ scfm
2. Temperature, Te = _ "F
3. Heat content, he = _ - Btu/lb
4. Oxygen content13, Oa = _ ___ %
Required destruction efficiency, DE = _ %
In the case of a permit review, the following data should be supplied by the applicant;
Catalytic incinerator system variables at standard conditions (77°F, 1 atm):
1 . Reported destruction efficiency, DEreported = _ _ %
2. Temperature of emission stream entering the incinerator,
Te = _ _____ "F (if no heat recovery);
The = _ °F (if emission stream is preheated)
3, Temperature of flue gas leaving the catalytic bed,
4. Temperature of combined gas stream (emission stream + supplementary fuel
combustion products) entering the catalyst bed,0
Tci= °F
alf dilution air is added to the emission stream upon exit from the process, the data required are
the resulting characteristics after dilution.
''The oxygen content depends on the oxygen content of the organic compounds (fixed oxygen)
and the free oxygen in the emission stream. Since emission streams treated by catalytic
incineration are generally dilute VOC and air mixtures, the fixed oxygen in the organic
compounds can be neglected.
clf no supplementary fuel is used, the value for this variable will be the same as that for the
emission stream.
C.4-1
-------
5. Space velocity, SV = hr"1
6. Supplementary fuel gas flowrate, Or = scfm
7. Flow rate of combined gas stream entering the catalyst bed,
Qcom = scfm
8. Dilution air flow rate, Qd = scfm
9. Catalyst bed requirement, Vfoed = ft3
10. Fuel heating value, hi = Btu/lb
4.3.2 Pretreatment of the Emission Stream: Dilution Air Requirements
For emission streams treated by catalytic incineration, dilution air typically will not be required.
However, if the emission stream heat content is greater than 135 Btu/lb or 10 Btu/scf for air +
VOC mixtures or if the emission stream heat content is greater than 203 Btu/lb or 15 BTU/scf
for inert + VOC mixtures, dilution air is necessary. For emission streams that cannot be
characterized as air + VOC or inert + VOC mixtures, assume that dilution air will be required if
the heat content is greater than 12 Btu/scf. In such cases, refer to Equation 4,3-1 presented
below or see Appendix C.2 where a blank calculation sheet for determining dilution air require-
ments is provided.
Qd = [(he/hd)-1]Qe 4.3-1
Qd = scfm
4.3.3 Design Variables, Destruction Efficiency, and Typical Operational Problems
Based on the required destruction efficiency (DE), specify the appropriate ranges for TCj and Too
and select the value for SV from Table 4.3-1.
Tot (minimum) = 600°F
Too (minimum) = 1,000°F
Tco (maximum) = 1,200°F
SV = hf1
In a permit review, determine if the reported values for TCj, Too, and SV are appropriate to achieve
the required destruction efficiency. Compare the applicant's values with the values in Table 4.3-1
and check if:
Tci (applicant) > 600°F and 1,200*F a Tco (applicant) * 1,000°F
C.4-2
-------
and
SV (applicant) S SV (Table 4.3-1 )
If the reported values are appropriate, proceed with the calculations. Otherwise, the applicant's
design is considered unacceptable. The reviewer may then wish to use the values in Table 4.3-1 .
4.3,4 Determination of Incinerator Operating Parameters
4.3.4.1 Supplementary Heat Requirements
1 . For dilute emission streams that require no additional combustion air:
a. Use Equation 4.3-2 to determine If Td = 600°F from Table 4.3-1 is sufficient
to ensure an adequate overall reaction rate without damaging the catalyst,
i.e., check if Top falls in the interval 1 ,000° - 1 ,200°F:
Tco = 600 + 50 he 4.3-2
If Tco'falls in the interval 1 ,000° - 1 ,20p°F, proceed with the calculations. If
Too is less than 1 ,000°F, assume Too is equal to 1 ,000°F and use Equation
4,3-3 to determine an appropriate value for Tdi; and then proceed with the
calculations:
Tci,= 1,000-50he 4.3-3
(Note: If Tco is greater than 1 ,2000F, a decline in catalyst activity may occur
due to exposure to high temperatures.)
b. Use Equation 4.3-4 to determine supplementary fuel requirements:
~ DeQe[Cpalr(1.1 Tcl-The-0.1 Tr)] 4.3-4
^ Df[hf-1.1Cpair(Td-Tr)]
The values for the variables in this equation can be determined as follows:
Qe Input data.
De 0.0739 Ib/ft3
Df 0.0408 Ib/ft3
ht Assume a value of 21 ,600 Btu/lb (for natural gas) if no other
information is available.
C.4-3
-------
Cpair See Table C.8-1 for values of Cpair at various temperatures.
Tci Obtain value from part "a" above or from permit applicant.
The For no heat recovery case, The = Te. For heat recovery case, use
the following equation if the value for The is not specified:
The - (HR/100)Tco + [1 - (HR/100)1 Te 4.3-5
where HR = heat recovery in the heat exchanger (percent).
Assume a value of 50 percent for HR if no other information is
available.
Tr 77°F
Of = scf m
4.3.4.2 Flow Rate of Combined Gas Stream Entering the Catalyst Bed
1. For dilute emission streams that require no additional combustion air, use Equations
4.3-6:
Qcom = Qe + Of + Qd 4.3-6
Qcom = SCfm
4.3.4.3 Flow Rate of Fiue Gas Leaving the Catalyst Bed
a. Use the result from the previous calculation:
Qfg = Qcom
Qfg = scf m
If Qtg is less than 2,000 scfm, define Qfg as 2,000 scfm.
b. Use Equation 4.3-7 to calculate Qfg,a.
Qjg,a = Qfg [(Too + 460)/537] 4.3-7
Qjg.a = acfm
4.3,5 Catalyst Bed Requirement
Use Equation 4.3-8 to estimate the catalyst bed volume.
= 60 Qcom/SV . 4.3-8
= __ ft3
C.4-4
-------
4.3.6 Evaluation of Permit Application
Compare the calculated values supplied by the applicant using Table 4,3-2.
If the calculated values for Hf, Qc» Qcom, and Vbed differ from the applicant's values, the differences
may be due to the assumptions involved in the calculations. Discuss the details of the design
and operation of the system with the applicant.
If the calculated and reported values are not different, then the design and operation of the
system can be considered appropriate based on the assumptions employed in this handbook.
Table 4.3-2 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Catalytic Incineration
Calculated Reported
Value Value
Continuous monitoring df combustion '•',..".
temperature rise and pressure drop across
catalyst bed
Supplementary fuel flow rate, Of ...
Dilution air flow rate, Qd ...
Flue gas stream flow rate, Qcom "...
Catalyst bed volume,
4.3.7 Capital and Annual Costs of Catalytic Incinerators
4.3.7.1 Catalytic Incinerator Capital Costs
Use the appropriate equation given in Table 4.3-3 to obtain the catalytic incinerator cost, CC,
CC = $
Use the factors given in Table 4.3-4 and the auxiliary equipment cost provided in Section 4.12
to obtain the purchased equipment cost, PEC.
PEC = CC + Auxiliary equipment-+ Sales tax + Freight
PEC = $ "-••
After estimating the PEC, simply use the factors given in Table 4.3-4 to obtain the total capita!
cost (TCC) estimate.
C.4-5
-------
TCC = 1 .61 PEC + SP + Bldg.
TCC = $ _
4.3.7.2 Catalytic Incinerator Total Annual Costs, TAC
The TAC consist of direct and indirect annual costs. Direct annual costs include fuel, electricity,
catalytic replacement, operating and supervisory labor, and maintenance labor and materials.
Indirect annual costs include overhead, administrative, property taxes, insurance, and capital
recovery costs.
Direct Annual Costs
1 . Fuel usage
The fuel usage is calculated in Section 4,3,4.1. Take this quantity (in scfm) and
multiply by 60 to obtain scfh and multiply this by the annual operating hours and the
fuel cost.
Annual fuel cost = Of x 60 x HRS x $3.30/1 ,000 ft3
Annual fuel cost = $ _ _
2. Electricity costs
Use Equation 4.3-9 to estimate the fan power requirement, Fp
Fp = 1 .81 x 1 0'4 (Qfg) (P) (HRS) 4.3-9
Fp = _ kWh/yr
Electricity costs = $0.059 (Fp)
Electricity costs = $ __
3. Catalyst replacement costs
The catalyst volume is obtained in Section 4.3.5. Multiply this volume by the
appropriate cost for base metal oxide ($650/ft3) or noble metal ($3,000/ft3) and by
0.5762, the capital recovery factor.
Catalyst replacement cost = (Vbed)($650/ft3 or $3,000/ft3) (0.5762)
Catalyst replacement cost = $ _
4. Operating costs
Operating labor costs = [(0.5 hr/shift)/(8 hr/shift)](HRS)($12.96/hr)
G.4-6
-------
Operating labor costs = $
Supervisory costs = 0.15 (Operating labor costs)
Supervisory costs = $ •
5. Maintenance costs
Maintenance labor costs = 1(0,5 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)]
Maintenance labor costs = $ .
Maintenance materials = 1.0 (Maintenance labor costs)
Maintenance materials = $
Total Direct Costs = $
Indirect Annual Costs
These costs are obtained from factors given in Table 4.3-6.
Overhead = $
Administrative = $
Property taxes = $
Insurance =$
Capital recovery = $
Total Indirect Costs = $
Total Annual Costs = Total Direct Costs + Total Indirect Costs
Total Annual Costs = $
C.4-7
-------
Page Intentionally Blank
-------
Appendix C.5
Calculation Sheet lor Flares
4.4.1 Data Required
HAP emission stream characteristics:
1. Expected emission stream flowrate, Qe = sefm
2. Emission stream temperature, Te = ; 8F
3. Heat content, he = Btu/scf
4. Mean molecular weight of emission stream MWe = lb/lb-mo!e
Flare tip diameter, Dtip = in
Required destruction efficiency, DE = %
In the case of a permit review, the following data should be supplied by the applicant:
Flare system design parameters at standard conditions (77°F, 1 atm):
1. Steam flowrate, Qs = ' Ib/min
2. Flare gas exit velocity, Uflg = ft/see
3. Supplementary fuel flow rate, Qt = scfm
4. Supplementary fuel heat content, hf = Btu/scf
5. Temperature of flare gas, Tflg = °F
6. Flare gas flowrate, Qflg = scfm
7, Flare gas heat content, hflg = Btu/scf
4.4.2 Determination of Flare Operating Variables
Based on studies conducted by EPA, relief gases having heating values less than 300 Btu/scf
are not assured of achieving 98 percent destruction efficiency when they are flared in stream-
er air-assisted flares.1
In a permit review case, if he is below 300 Btu/scf and no supplementary fuel is used, then the
application is rejected. The reviewer may then wish to proceed with the calculations below. If he
is equal to or above 300 Btu/scf, then the reviewer should skip to Section 4.4.2.3,
1For unassisted flares, the lower limit is 200 Btu/scf.
C.5-1
-------
4.4.2.1 Supplementary Fuel Requirements
For ©mission streams with heat contents less than 300 Btu/scf, additional fuel is required. Use
Equation 4.4-1 to calculate natural gas requirements;
Of = [(300 - he) Qe]/582 4.4-1
Of = _ scfm
4.4.2.2 Flare Gas Flow Rate and Heat Content
a. Use Equation 4.4-2 to calculate the flare gas flow rate:
Qflg = Qe + Of 4.4-2
scfm
b. Determine the flare gas heat content as follows:
= 300 Btu/scf if Of > 0
= he if Of = 0
hflg = _ BtU/SCf
4.4.2.3 Flare Gas Exit Velocity
a. Use Table 4.4-1 to calculate Umax:
If 300 as hfjg < 1 ,000 use the following equation:
Umax = 3.28 [10<0-00118hfla*0-908^
Umax =
If hflg fe 1,000 Btu/scf, Umax = 400 fl/sec
b. Use Equation 4.4-3 to calculate Uflg:
Uflg = (5.766 X lO-^QflgXTflg + 460)/(Dtip2) 4.4-3
_ fl/sec
c. Compare Uflg and Umax:
If Uflg •& Umax, the desired destruction efficiency level of 98 percent can be
achieved. (Note: Uflg should exceed 0.03 fl/sec for flame stability.) If Uflg
> Umax, 98 percent destruction efficiency cannot be achieved. When
evaluating a permit, reject the application in such a case.
C.5-2
-------
4.4.2.4 Steam Requirements
a. Assume that the amount of steam required is 0.4 lb steam/lb flare gas. Use
equation 4.4-4 to calculate Qs:
Qs = 1.03x1Q'3xQflgxMWflg 4.4-4
Qs = Ib/min
4.4.3 Evaluation of Permit Application
Compare the calculated and reported values using Table 4.4-2. If the calculated values of Of,
Uflg, Qflg, and Qs are different from the reported values for these variables, the differences may
be due to the assumptions (e.g., heating value of fuel, ratio of steam to flare gas, etc.) involved
in the calculations. Discuss the details of the design and operation of the system with the
applicant. If the calculated and reported values are not different, then the operation of the system
can be considered appropriate based on the assumptions employed in the handbook.
Table 4.4-2 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Flares
Calculated Reported
Value Value
Appropriate continuous monitoring of system
Emission stream heating value, he ...
Supplementary fuel flow rate, Qf
Flare gas exit velocity,
Flare gas flow rate,
Steam flow rate, Qs
4.4.4 Capital and Annual Costs for Flares
4.4.4.1 Capital Costs of Flares
Calculate the flame angle 9 using Equation 4.4-6 which is derived from Equation 4.4-5.
8 = TAN'1 (88.2/Uflg) 4.4-6
Next, calculate the flare height H using Equation 4.4-7.
H = [(0.01285) (Qflg x hflg)1/2 - 6.05 x 10-3 (Dtip) (Uflg)( Cos(0))] 4.4-7
C.5-3
-------
Once H is calculated, select the appropriate value for H as a multiple of 5 with a minimum of 30
feet The flare cost FC is estimated using equations 4.4-8, 4.4-9, or 4.4-10.
FC = [78 + 9.14 (Dtip) + 0,749 (H)]2 4.4-8
where: FC = flare cost for self support
FC = [103 + 8.68 (Dtip) + 0.470 (H)]2 4,4-9
where: FC = flare cost for guy support
FC m [76.4 + 2.72 (Dtip) + 1.64 (H)]2 4.4-10
where: FC = flare cost for derrick support
The equipment cost (EC) is obtained by adding the auxiliary equipment cost and the flare cost,
FC.
EC = FC + Aex
EC = $
The purchased equipment cost (PEC) is obtained using the factors given in Table 4.4-3.
PEC = EC + Instrumentation & Sales tax & Freight
PEC = $
After estimating the PEC, simply use the factors given in Table 4.4-3 to obtain the total capital
costs (TCC).
TCC = 1.92 PEC + SP + Bldg.
TCC = $
4.4.4.2 Flare Total Annual Costs, TAG
The TAG consist of direct and indirect annual costs. Direct annual costs include fuel, electricity,
steam, operating labor, and maintenance labor. Indirect annual costs consist of overhead,
administrative, property taxes, insurance, and capital recovery costs.
Direct Annual Costs
1. Fuel usage
The fuel usage is calculated in Section 4.4.2.1. Take this value and multiply it by 60
to obtain scfh, by the annual operating hours per year, and the cost of fuel.
Annual fuel cost = Of x 60 x HRS x $3.30/1,000 ft3
C.5-4
-------
Annual fuel cost = $
2. Electricity costs
Equation 4.4-11 is used to estimate the power requirement. This value is then
multiplied by the cost of electricity to obtain the Annual Electricity Cost.
Fp = 1.81 x10"4(Qflg,a)(P){HRS} 4.4-11
Fp = kWh/yr
Annual electricity cost = $0.059 (Fp)
Annual electricity cost = $_____
3. Steam requirement
The steam requirement for a flare is calculated in Section 4.4.2.4. Take this quantity
(Qs) and multiply by 60, by the annual operating hours, and by the cost of steam to
obtain annual costs.
Annual steam costs = Qs x 60 x HRS x $6,00/1,000 Ib
Annual steam costs = $
4. Operating costs
Operating labor costs = {(0.5 hr/shift)/(8 hr/shift}](HRS)($12.96/hr)
Operating labor costs = $
Supervisory costs = 0,15 (Operating labor costs)
Supervisory costs = $
5. Maintenance costs
; Maintenance labor costs = [(0.5 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)
Maintenance labor costs = $
Maintenance materials = 1.0 (Maintenance labor costs)
Maintenance materials = $
Total Direct Costs = $
C.5-5
-------
Indirect; Annual Costs
These costs are obtained from factors given in Table 4,3-6.
Overhead = $
Administrative = $
Property taxes = $
Insurance = $ ,
Capital recovery = $
Total Indirect Costs = $
Total Annual Costs = Total Direct Costs + Total Indirect Costs
Total Annual Costs = $ .
C.5-6
-------
Appendix C.6
Calculation Sheet for Carbon Adsorption
4.6.1 Data Required
HAP emission stream characteristics:
1, Maximum flow rate, Qe = scfm
2. Temperature, Te = °F
3. Relative humidity, Rhum = %
4. HAP=
5. Maximum HAP content, HAPe = ppmv
Required removal efficiency, RE = %
In the case of a permit review, the following data should be supplied by the applicant:
Carbon adsorber (fixed-bed) system variables at standard conditions {77°F, 1 atm):
1. Reported removal efficiency, REreported = %
2, HAP inlet loading rate, MHAP = Ib/hr
3. HAP content, HAPe = ppmv
4. Emission stream flow rate, Qe = . scfm
5. Working capacity of carbon bed, Wc = Ib HAP/lb carbon
6. Number of beds, N =
7. Amount of carbon required, Cr@q = ' Ib
8. Cycle time for adsorption, 6ad = hr
9. Cycle time for regeneration, 8reg = hr
10. Emission stream velocity through the bed, Ue = ft/min
11. Vessel length U = ft
12. Vessel diameter, Dv = - ft
13. Steam used for regeneration, Qs = Ib steam/min
C.6-1
-------
4.6.2 Adsorption Theory
1. Partial pressure of HAP, P
P = (HAPe) x14.696 x10"6 psia
P = psia
2. Equilibrium and working capacity, We and Wc
We = kPm
Obtain k and m from Table 4.6-1 or appropriate reference
We = Ibs HAP/ibs carbon
We * Ibs HAP/lbs carbon (Wc = 0.5 We if no information available)
Note: Wc = 0.100 if no information available.
4.6.4 Pretreatment of the Emission Stream
Cooling
Te = °F
If the temperature of the emission stream is higher than 130°F, a heat exchanger is needed to
cool it to 130°F or less. Refer to a suitable reference for the calculation procedure.
Dehumidification
Rhum = % . . _ .___..
If the relative humidity level is above 50 percent and the HAP concentration is less than 1000
ppmv, a condenser may be required to cool and condense the water vapor in the emission
stream. Refer to Section 4.8 for more details. '
High VOC Concentrations
HAPe = ppmv
If flammable vapors are present in the emission stream, the VOC content should be limited to
below 25 percent of the LEL.
LEL = ppmv (from Table 4.2-1)
C.6-2
-------
25% of LEL = 0.25 x LEL (ppmv) = _ ppmv
The maximum practical inlet concentration for carbon beds is about 10,000 ppmv. If HAPe is
greater than 10,000 ppmv, carbon adsorption may not be applicable.
4.6.6 Fixed Bed Regenerative Systems
4.6.6.1 Fixed Bed Design
a. Use Equation 4.6-1 to calculate the required carbon amount Creq:
MHAP ©ad (1 + ND4JA) 4.6-1
_ .
req=
Creq = _______ Ibs
C'req=Creq/NA
i
C req = _
b. Obtain MHAP if not given using formula 4.6-2.
MHAP - 6.0 x 1 0'5 {HAPe)(Qe)(DHAP) 4.6-2
MHAP = _ Ib/hr
where:
DHAP = PM/RT
DHAP = __ _ Ibs/ft3
Equations 4.6-3, 4.6-4, and 4.6-5 are used to obtain the vessel diameter, Dv, and the vessel
length, Lv, and the vessel size, S:
Dv=(0.127)(C'req)(Ue)/(Q'e,a) 4.6-3
where:
Qe,a - Qe(Te + 460)/537
Qe,a = _ acfm
Q'e,a = Qe,a/NA
Dv= ft
C.6-3
-------
Lv = (7.87)(Qeia/Ue)2/Creq 4.6-4
Lv = _ ft
4.6-5
S=_ _ ft2
4.6.6.2 Carbon Adsorber Efficiency
Use Table 4.6-2 to determine the adsorption time 6ad, the regeneration time ereg, and the steam
requirement St, for a given outlet concentration.
Bad = _ hr
0reg = _ ___ hr
St = ___ Ib steam/lb carbon
4.6.6.3 Steam Required for Regeneration
Use Equation 4.6-6 to calculate steam requirements:
Qs = NA[StxC'req/(8reg-edry-cool)]/60 4.6-6
Assume 8dry-cooi = 0.25 hrs, if no information available,
Qs = _ Ib/min
Calculate Qs /Abed:
i
Abed = Qe,a/Ue
Abed = _
= _ Ib steam/min-ft2
If Qs /Abed is greater than 4 Jb steam/min-ft2, fluidization of the carbon bed may
occur.
4.6.7 Evaluation of Permit Application
Compare the results from the calculations and the reported values using Table 4.6-3.
If the calculated values of Creq, Dv, U, S, and Qs are different from the reported values, the
differences may be due to the assumptions involved in the calculations. Discuss the details of
the design and operation of the system with the applicant.
C.6-4
-------
If the calculated values agree with the reported values, then the design and operation of the
proposed carbon adsorber system may be considered appropriate based on the assumptions
made in this handbook.
Table 4.6-3 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Carbon Adsorption
Calculated Reported
Variable Value Value
Continuous Effluent Monitoring ... ...
Carbon Requirement, Greg ...
Vessel Diameter; Dv ... ...
Vessel Length, U ...
Vessel Size, S ... ...
Steam Regeneration Rate, Qs ... ...
4.6.8 Capital and Annual Costs of Fixed Bed Regenerative Adsorbers
4.6.8.1 Costs of Carbon
Equation 4.6-7 is used to obtain the carbon costs, C0:
Co = $2.00 (Creq) 4.6-7
C— 4;
c = s>
4.6.8.2 Vessel Costs
Use Equation 4.6-8 to obtain the vessel costs.
CV = 271S°-7712 4.6-8
Cy = $ . . ..- ,.
If necessary, multiply Cv by the appropriate construction factor given in Table 4.6-4:
Cy = Fm Cv
C.6r5
-------
4.6.8.3 Purchased Equipment Cost, PEC
Equation 4.6-9 is used to obtain the equipment cost EC:
EC = Rc[C0 + Cv (NA -f ND)1 + Ductwork and dampers 4.6-9
i
where:
RC = 5.82Qe,a-a133
Thus,
RC =
EC = $
Use the factors provided in Table 4.6-5 to obtain the purchased equipment cost, PEC.
PEC = 1.08 EC
PEC = $
4.6.8.4 Total Capital Cost, TCC
Use the factor provided in Table 4.6-5 to obtain the total capital cost, TCC.
TCC = 1.61 PEC + SP + Bldg.
TCC = $ ' '
4.6.8.S Fixed Bed Carbon Adsorption Annual Cost Estimates
The annual cost estimate consists of the sum of direct and indirect costs, as well as recovery
credits.
Direct Annual Costs
1. Steam costs, Cs
Equation 4.6-10 is used to estimate this cost.
Cs = Qs(60)(HRS)(Ps)/1,000 4.6-10
Cs = $ .
2. Cooling water costs, CCw
Equation 4.6-4 is used to estimate this cost.
C0w = 3.43(Cs/Ps)(Pow) 4.6-11
c.e-6
-------
Ccw = $ _ ', .
3. Electricity cost, AEC
a. Pressure drop through the bed, Pb
Pb = [0.03679 Ue+ 1.1 07 x 1 0'4 Ue 2][0.0333 C'req /UDVJ 4.6-12
Pb - _ _________ inches H2O
b. System fan horsepower, hpsf
hpSf = 2.5x10"4(Qefa)(Pb+1) 4.6-13
hpSf = _ hp
c. Bed drying/cooling fan
Operating time Octet:
0dcf = 0.4 0reg (NA)(HRS)/0ad 4.6-14
0dcf=_ _ _ - • -..-/•• :. • :
Flowrate, FRdcf
FRdcf =(100(Cri,))/0dry-cool 4.6-15
Power requirement,
Pdcr-1.86x10'4(FRdcf)(Pw-1)(edcf) 4.6-16
Pdcf = _ kWh/yr
d. Cooling water pump horsepower, hpcwp
= (2.52x10'4qcwHSg)/n 4.6-17
_ hp
e. Electricity usage, Fp
Fp m 0.746 [hpsf + hpcwp] HRS + Pdcf 4.6-18
Fp = _ __kWh/yr ,-.-"' >: -'-.-"•. --. • '
C.6-7
-------
f. Annual electricity cost, AEC
AEC = 0.059 (Fp) 4.6-19
4. Carbon replacement cost, CRCC
CRCC = CRFC(1.08CC
CRCc » 0.2638 (1.08 Cc + 0.05 Creq)
CRCC - $ _ _
5. Operating coste
Operating labor costs = [(0.5 hr/shift)/(8 hr/shift)](HRS)($12.96/hr)
Operating labor costs = $ _
Supervisory costs = 0.15 (Operating labor costs)
Supervisory costs = $ __
6. Maintenance costs
Maintenance labor costs = [(0.5 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)
Maintenance labor costs = $ __
Maintenance materials = 1 .0 (Maintenance labor costs)
Maintenance materials = $ _
Total Direct Annual Costs = $ __
Indirect Annual Costs
Use the factors provided in Table 4.6-7 to estimate these costs:
Overhead = $ __
Property tax = $ .
Insurance = $ _
Administrative = $ __
c.e-8
-------
Capital recovery =$
Total Indirect Annual Costs = $ _
Recovery Credits
Use Equation 4.6-20 to estimate the quantity of recovered HAP.
Qrec= (MHAP) (HRS) (RE/1 00) 4.6-20
Qree =
To obtain the value of recovery credits, simply multiply Qrec by the value of the
recovered HAP.
Recovery Credits = (Qree) (Value of HAP)
Recovery Credits = $ ____ __
Total Annual Costs = Total Direct Costs + Total Indirect Costs - Recovery Credits
Total Annual Costs: $ _____ _
4.6,9 Carbon Canister System Design
4.6.9.1 Carbon Requirement
Use Equation 4.6-22 to estimate the carbon requirement for a canister system:
Creq = (MHAP) (8ad)/(Wc) 4.6-22
Creq = , _ Ib
If not given, MHAP can be obtained using Equation 4.6-2.
MHAP - 6.0 x10'5(HAPe)(Qe)(DHAp) 4.6-2
MHAP = _ _ Ib/hr
To calculate the required canister number (RCN) divide Q-eq by the amount of carbon contained
in a single canister and round up to the next whole number (typically 150 Ibs).
RCN = Creq /150
RCN =
C.6-9
-------
4.6.9.2 Evaluation of Permit Application
Use Table 4.6-9 to evaluate the permit application by comparing the results from the calculations
to the reported values.
If the calculated values of 0ad, Creq, MHAP, and RON are different than the reported values, the
differences may be due to the assumptions involved with the calculations.
If the calculated values agree with the reported values, then the design and operation of the
proposed canister system may be considered appropriate based on the assumptions made in
this handbook.
Table 4.6-9 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Carbon Canister Systems
Calculated Reported
Variable Value Value
Adsorption time, 6ad .. •
MHAP, Ib/hr
Carbon Requirement, Creq
Required Canister Number, RCN ...
4.6.10 Capital and Annual Costs of Canister Systems
4.6.10.1 Capital Costs of Canister Systems
Use Equation 4.6-23 and Table 4.6-10 to estimate the total capital cost of a canister system.
TCC=1.2(CEC) 4.6-23
where: CEC = {1.1)(1.08)(RCN)(EC)
TCC =» $
4.6.10.2 Annual Costs for Canister Systems
The annual costs of a canister system are the sum of the direct and indirect annual cost. No
recovery credits are available for a canister system.
Direct Costs
1. Electricity
a. Pressure drop, PC
C.6-10
-------
Use Equation 4.6-24 to estimate the pressure drop.
PC - 0.0471 Q'e,a + 9.29 X 1 0"4 [Qe,'af 4.6-24
Pc = _ in. HaO
b. Once PC is estimated, use Equation 4.6-25 to calculate the horsepower
requirements
= 2,5x10"4[Pc+1IQe,a] 4.6-25
hpsf = _ hp
c. The required electricity usage Fp is found from Equation 4.6-26.
Fp = 0.746 (hpsf) HRS 4.6-26
Fp - _ kWh/yr
d. The annual electricity cost is then obtained by multiplying Fp by the cost
of electricity.
Annual electricity cost = $0.059 (Fp)
Annual electricity cost = $ _
2. Solid waste disposal
This cost can vary significantly from site to site. For purposes of this manual, this
cost has been estimated at $65/canister.
Disposal costs = $65/canister [RCN]
Disposal costs = $ _
There are no operating or maintenance costs assumed for carbon canister
systems.
Indirect Costs
These costs are obtained from the factors provided in Table 4.6-5.
Property tax -$, _
Insurance = $ _
Administrative =$___ _
C.6-11
-------
Capital recovery = $
Canister expense = $
Total Indirect Costs = $
Total Annual Costs = Total Direct Costs + Total Indirect Costs
Total Annual Costs = $
C.6-12
-------
Appendix C.7
Calculation Sheet for Absorption
4.7.1 Data Required
HAP emission stream characteristics:
1. Maximum flow rate, Qe = scfm
2. Temperature flow rate. Te = . "F
a HAP = . •
4. HAP concentration, HAPe = ppmv
5. Pressure, Pe = mm Hg
Required removal efficiency, RE = . %
In the case of a permit review, following data should be supplied by the applicant:
Absorption system variables at standard conditions (77°F, 1 atm):
1. Reported removal efficiency, REreported = %
2, Emission stream flow rate, Qe = scfm
3, Temperature of emission stream, Te = ' °F
4. Molecular weight of emission stream = Ib/lb-mole
5. HAP =
6. HAP concentration, HAPe = ' ppmv
7. Solvent used =
8. Slope of the equilibrium curve, m =
9. Solvent flow rate, Lgai = gal/min
10. Density of the emission stream, De = Ib/ft3
11. Schmidt No. for the HAP/emission stream and HAP/solvent systems:
SCQ =
SCL =
C.7-1
-------
(Refer to Reference 1, or Reference 3 in Section 4.7 for definition and calculation
of SCQ and Set)
1 2. Properties of the solvent:
Density, DL = _ Ib/ft3
Viscosity, ILL = _ centipoise
1 3. Type of packing used = __
1 4. Packing constants:
a = _ b =
e= _ Y =
c =
s =
d =
g =
15. Column diameter, Dcoiumn = __ ft
16. Tower height, (packed) Ht column = _ ft
17. Pressure drop, Ptotai = __ in. HaO
4.7.3 Determination of Absorber System Design and Operating Variables
4.7.3.1 Solvent Flow Rate
a. Assume a value of 1 .6 for AF.
Determine "m" from the equilibrium data for the HAP/soivent system under
consideration (see References 1 , 3, and 6 in Section 4.7 for equilibrium
data).
rn= _
Use Equation 4.7-3:
Qa = scfm 4.7-3
Gm0! = 0.155Qe
Gmoi - Ib moles/hr
b. Use Equation 4.7-2:
Lmol = 1.6 m Gmol 4.7-2
C.7-2
-------
Lmoi= Ib-moles/hr
c. Use Equation 4.7-5:
Lgal = 0.036 Lmoi 4.7-5
gal/min
4.7.3.2 Column Diameter
a. Use Figure 4.7-2:
Calculate the abscissa (ABS) using Equation 4.7-6:
MWSoivent = : Ib/lb-mole
L = Lmol X MWsolvent
L= Ib/hr . . . .
MWe = Ib/lb-mole >
G = Gmol x MWe :
G= Ib/hr . '. ••••-•• • • .
DG = Ib/ft3 (refer to Section 4.7.3.2 to calculate this
variable)
DL = Ib/ft3 (from reference 1, Section 4.7)
ABS = (L/G)(DG/Di_)0'5 4.7-6
ABS - - ' ' - ' • • •••••'
b. From Figure 4.7-2, determine the value of the ordinate (ORD) at flooding
conditions.
ORD= '
c. For the type of packing used, determine the packing constants from
Reference 11, Section 4.7:
a = ,
Qm
Determine pt (from reference 1):
C.7-3
-------
ML- _ cp
d Use Equation 4.7-8 to calculate Garea,t:
Garea,f - {[ORD DGDL gcM(a/e3)(|lL)a2]}0'5 4.7-8
Garea,f = _ !b/sec-ft2
e. Assume a value forthe fraction of flooding velocity forthe proposed design:
f = _ (typically, 0.60 £ f £ 0.75)
Use Equation 4.7-9 to calculate Garea:
Garea «= f Garea,! 4.7-9
Garea = ' _ Ib/hr-ft2
f. Use Equation 4.7-10 to calculate the column cross-sectional area;
Aoolumn - G/(3,600 Garea) 4.7- 1 0
Acolumn = _ ft
g. Use Equation 4.7-1 1 to calculate the column diameter:
Dcolumn = 1 . 1 3 (A column)0'5 4.7-1 1
Dcotumn = _ _ ft
4.7.3.3 Column Height
a. Use Equation 4.7-13 or Figure 4.7-3 to calculate NOG:
Using Equation 4.7-13 and 4.7-14:
HAPe = _ pprnv
HAPo - HAPe (1 - RE/1 00) 4.7- 1 4
HAPo = _ ppmv
Nog = In {(HAPe/HAP0)[1 - (1/AF)] + (1/AF)}/[1 - (1/AF)] 4.7-1 3
Nog = _
Using Figure 4.7-3:
HAPe/HAPo - _
C.7-4
-------
At HAPe/HAPo and 1/AF = 1/1 .6 = 0.63, determine Nog:
b. Use Equations 4.7-1 6, -1 7, and -1 5 to calculate He, HL, and Hog. Determine
the packing constants in Equations 4.7-16 and 4.7-17 using Tables C.7-1
and C.7-2.
Y =
Determine SCG and Set using Tables C.7-3 and C.7-4;
SCQ = _
SCL = _ _
L" = L /A column . 4.7-18
L" = _ Ib/hr-ft2
IJ.L" = _ Ib/hr-ft (from reference 1 )
Calculate HQ and HL:
HG = [b (3,600 Garea)C/(L")d](SCG)a5 4.7-16
___ _ ft
HL = Y(L"4iL")s(ScL)0'5 4.7-17
HL = _ ft . ; , • '. ...
Calculate Hog using AF = 1 .6:
Hog = HG + (1/AF)Hi_ 4.7-15
Hog = _ ft . . • ' -
c. Use Equation 4.7-1 2 to calculate Ht column:
Ht column = NogHog 4.7-1 2
Ht column = _ ft
d. Use Equation 4.7-19 to calculate Httotai:
C.7-5
-------
Ht total = Ht column + 2t (0.25 Dcolumn) , 4.7-19
Ht total = _ ft
e. Use Equation' 4.7-20 to calculate Vpacking:
VpacWng = 0.785(Dcoiumn)2 X Htcolumn 4.7-20
*3 t
Vpacking = _ ft
4.7.3.4 Pressure Drop Through the Column
a. Use Equation 4.7-21 to calculate Pa:
Determine the constants using Table C.7-5:
g= _
Pa = g X 1 0'8[1 0(rL"/DL)](3,600 Gareaf/Do 4.7-21
Pa = _ !b/ft2-ft
b. Use Equation 4.7-22 to calculate Ptotai:
Ptotal = Pa X (Ht column) 4.7-22
Ptotal = _ Ib/ft2
(Ptota!/5.2) = __ in. H20
4. 7.4 Evaluation of Permit Application
Compare the results from the calculations and the values supplied by the permit applicant using
Table 4.7-1 . If the calculated values are different from the reported values, the differences may
be due to the assumptions involved in the calculations. Therefore, discuss the details of the
proposed design with the applicant.
If the calculated values agree with the reported values, then the design of the proposed absorber
system may be considered appropriate based on the assumptions made in this handbook.
47.5 Capital and Annual Costs of Absorbers
4.7.5.1 Capital Costs of Absorbers
Use Figure 4.7-4 to obtain the cost of the absorber tower. Table 4.7-2 can be used to estimate
the cost of packing based on the volume of packing calculated in 4.7.3.3. The cost of auxiliary
equipment is obtained from Section 4.12. The equipment cost is the sum of these three costs.
C.7-6
-------
Table 4.7-1 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Absorption
Calculated Reported
Value Value
Solvent flow rate, Lgai
Column diameter, Dcoiumn ... ...
Column height, Ht column
Total column height, Ht total ...
Packing volume, Vpacking
Pressure drop, Ptotai
1. Absorbertowercost =
2. Packing cost •$
3. Auxiliary equipment cost - $,
4. Equipment cost, EC =* 1. + 2. + 3. =4
The purchased equipment cost, PEC, is obtained from the equipment cost calculated above and
the factors provided in Table 4.7-3.
PEC = EC 4- Instrumentation + Sales tax + Freight
'.. • PEG = $ • . .,
The total capital cost (TCC) is estimated using the PEC and the factors given in Table 4.7-3.
TCC - 2.20 PEC + SP + Bldg.
-' TCCW$__ ...' ' " . '
4.7.5.2 Annual Costs for Absorbers
The annual costs of an absorbersystem consists of direct and indirect annual costs. For purposes
of this manual, recovery credits are assumed zero.
Direct Costs.
1. Electricity cost
C.7-7
-------
A. Use Equation 4.7-23 to estimate the fan power requirements, Fp.
Fp = 1.81 x 1 (T4 (Qe,a)(Ptotal)(HRS) 4.7-23
Fp = _kWh/hr
where:
Qe,a= Qe (Te + 460)7537
Qe,a = acfm
B. The annual electricity cost is then:
Annual electricity cost = $0.059 (Fp)
Annual electricity cost = $
2. Solvent cost
Equation 4,7-24 is used to estimate the annual solvent requirement.
Annual solvent requirement = (60)(Lgai){HRS) 4.7-24
Annual solvent requirement = gal/yr
The solvent cost is obtained from multiplying the annual solvent requirement and
the solvent cost, given in Table 4.7-5.
Annual solvent cost = $0.20/1,000 gal x (Annual solvent requirement)
Annual solvent cost = $
3. Operating labor cost
Operating labor = [(0.5 hr/shift)/(8 hr/shift)](HRS)($12.96/hr)
Operating labor = $
Supervisory costs = 0.15 (Operating labor)
Supervisory costs = $
4. Maintenance costs
Maintenance labor = [(0.5 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)
Maintenance labor = $
C.7-8
-------
Maintenance materials = 1.0 (Maintenance labor)
Maintenance materials = $
Total Direct Costs = $
Indirect Costs
These costs are obtained from the factors provided in Table 4.7-i,
Overhead = $
Property tax = $
Insurance =$_ ' -
Administrative =$___
Capital recovery = $ -
Total indirect Costs =$- ' ; .. .
Total Annual Costs = Total Direct Costs + Total Indirect Costs
Total Annual Costs = $ - -"
C.7-9
-------
Table C.7-1 Constants for Use in Determining Height of a Gas Film Transfer Unit3
Range of
Packing
Raschig rings
3/8 in.
1 in.
1-1/2 in.
2 in.
Berl saddles
1/2 in.
1 in.
1-1/2 in.
3-in partition rings
Spiral rings
(stacked staggered)
3-in. single spiral
3-in. triple spiral
Drip-point grids
No. 6146
No. 6295
aReference 1 1 of Section
b
2.32
7.00
6.41
17.30
2.58
3.82
32.40
0.81
1.97
5.05
650
2.38
15.60
3.91
4.56
4.7.
c
0.45
0.39
0.32
0.38
0.38
0.41
0.30
0.30
0.36
0.32
0.58
0.35
0.38
0.37
0.17
d
0.47
0.58
0.51
0.66
0.40
0.45
0.74
0.24
0.40
0.45
1.06
0.29
0.60
0.39
0.27
3,600 Garea
(Ib/hr-ft2)
200 to 500
200 to 800
200 to 600
200 to 700
200 to 700
200 to 800
200 to 700
200 to 700
200 to 800
200 to 1,000
150 to 900
130 to 700
200 to 1,000
130 to 1,000
100 to 1,000
L"
(Ib/hr-ft2)
500 to 1,500
400 to 500
500 to 4,500
500 to 1,500
1,500 to 4,500
500 to 4,500
500 to 1,500
1,500 to 4,500
400 to 4,500
400 to 4,500
3,000 to 10,000
3,000 to 10,000
500 to 3,000
3,000 to 6,500
2,000 to 11, 500
C.7-10
-------
Table C.7-2 Constants for Use in Determining Height of a Liquid Film Transfer Unit'
Packing
Raschig rings
3/8 in.
1/2 in.
1 in.
1-1/2 in.
2 in.
Bert Saddles
1/2 in.
1 in.
1-1/2 in.
3-in. Partition rings
(stacked, staggered)
Spiral rings (stacked, staggered)
3-in. single spiral
3-in. triple spiral
Drip-point grids (continuous flue)
Style 61 46
Style 6295
Y
0.00182
0.00357
0.0100
0.0111
0.0125
0.00666
0.00588
0.00625
0.0625
0.00909
0.0116
0.0154
0.00725
S
0.46
0.35
0.22
0.22
0.22
0.28
0.28
0.28
0.09
0.28
0.28
, 0.23
? 0.31
Range of L"
(Ib/hr-ft2)
400-15,000
400-15,000
400-15,000
400-15,000
400-15,000
400-15,000
400-15,000
400-15,000
3,000-14,000
400-15,000
3,000-14,000
3,500-30,000
2,500-22,000
Reference 1 1 of Section 4.7.
..C.7-11
-------
Table C.7-3 Schmidt Numbers for Gases and Vapors in Air at 77°F and 1 ATM2
Substance
(Serf
Substance
'Reference 13 of Section 4.7.
b,
(Serf
Ammonia
Carbon dioxide
Hydrogen
Oxygen
Water
Carbon disulfide
Ethyl ether
Methano!
Ethyl alcohol
Propyl alcohol
Butyl alcohol
Amyl alcohol
Hexyl alcohol
Formic acid
Acetic acid
Propionic acid
i-Butyrfe aid
0.66
0.94
0.22
0.75
0.60
1.45
1.66
0.97
1.30
1.55
1.72
2.21
2.60
0.97
1.16
1.56
1.91
Valeric acid
i-Caproic acid
Diethyl amine
Butyl amine
Aniline
Chloro benzene
Chloro toluene
Propyl bromide
Propyl iodide
Benzene
Toluene
Xylene
Ethyl benzene
Propyl benzene
Diphenyl
n-Octane
Mesitylene
2.31
2.58
1.47
1.53
2.14
2.12
2.38
1.47
1.61
1.76
1.84
2.18
2.01
2.62
2.28
2.58
2.31
BOG = H.G/PQDG where DG and U.Q are the density and viscosity of the gas stream and PG is
the diffusivity of the vapor in the gas stream.
C.7-12
-------
Table C.7-4 Schmidt Numbers for Compounds In Water at
Soluteb (Set)0 Soluteb
(ScQc
Oxygen
Carbon dioxide
Nitrogen Oxide
Ammonia
Bromine
Hydrogen
Nitrogen
Hydrogen chloride
Hydrogen sulfide
Sulfuric acid
Nitric acid
Acetylene
Acetic acid
Methanol
Ethanol
PropanoJ
Butanol
AHyl alcohol
Phenol
558 Glycerol
559 Pyrogallol
665 Hydroquinone
570 Urea
840 Resorcinol
196 Urethane
613 Lactose
381 Maltose
712 Mannitol
580 Raffinose
390 Sucrose
645 Sodium chloride
1,140 Sodium hydroxide
785 Carbon dioxided
1,005 Phenold
1,150 Chloroformd
1,310 Acetic acid8
1,080 Ethylene dichloride®
1,200
1,400
1,440
1,300
946
1,280
1,090
2,340
2,340
1,730
2,720
2,230
745
665
445
1,900
1,230
479
301
Reference 13 of Section 4.7.
bSolvent is water except where indicated.
cSci_ - ^L/PtDt where PL and PL are the viscosity and density of the liquid and DL is the diffusivity
of the solute in the liquid.
dSolvent is ethanol.
eSolvent is benzene.
C.7-13
-------
Table C.7-5 Pressure Drop Constants for Tower Packing3
Packing
Raschig rings
Berl saddles
Intalox saddles
Drip-point
grid tiles
Nominal
size, (in.)
1/2
3/4
1
1-1/2
2
1/2
3/4
1
1-1/2
1
1-1/2
No. 6146
Continuous flue
Cross flue
No. 6295
Continuous, flue
Cross flue
g
139
32.90
32.10
12.08
11.13
60.40
24.10
16.10
8.10
12.44
5.66
1.045
1.218
1.088
1.435
r
0.00720
0.0045
0.00434
0.00398
0.00295
0.00340
0.00295
0.00295
0.00225
0.00277
0.00225
0.00214
0.00227
0.00224
0.00167
Range of L™
(Ib/hr-ft2)
300 to 8,600
1,800 to 10,800
360 to 27,000
720 to 18,000
720 to 21 ,000
300 to 14, 100
360 to 14,400
720 to 78,800
720 to 21 ,600
2,520 to 14,400
2,520 to 14,400
3,000 to 17,000
300 to 17,500
850 to 12,500
900 to 12,500
Reference 13 of Section 4.7.
C.7-14
-------
Appendix C.8
Calculation Sheet for Condensation
4.8.1 Data Required
HAP emission stream characteristics:
1. Maximum flow rate, Qe
;
2. Temperature, Te = ,
3. HAP =
scfm
ppmv
4. HAP concentration, HAPe = :
5. Moisture content, Me = %
6. Pressure, Pe = mm Hg
In the case of a permit review for a condenser, the following data should be supplied by the
applicant: .
Condenser system variables at standard conditions (77°F, 1 atm):
1. Reported removal efficiency, REre>p0ited = ; _%
2. Emission stream flow rate, Qe = scfm
3. Temperature of emission stream, Te = °F
4, HAP =
5. HAP concentration, HAP6 =
6. Moisture content, Me =
.ppmv
7. Temperature of condensation, Texan =
8. Coolant used =
9. Temperature of inlet coolant, Tcooy =
10. Coolant flow rate, Qcooiant = Ib/hr
11. Refrigeration capacity, Ref =
tons
12. Condenser surface area, Aeon =,
13. Specific Heat of HAP, CPHAP = _
Btu/lb-moPF
C.8-1
-------
14. Heat of vaporization of HAP, AH = Btu/lb-mo!
4.5.2 Pretreatment of the Emission Stream
Check to see if moisture content of the emission stream is high. If it is high, dehumidification is
necessary. This can be carried out in a heat exchanger prior to the condenser.
4.8.3 Condenser System Design Variables
The key design variable is the condensation temperature. Coolant selection will be based on
this temperature,
4.8.3.1 Estimating Condensation Temperatures
a. Use Equation 4.8-1 to calculate Ppartai:
Pparfai = 760{(1 - 0.01 RE)/[1 - (RE x 10'8 HAPe)]}HAPe x 10"6 4.8-1
Ppartai = mm Hg
b. Use Figure 4.8-2 to determine TCon:
Toon = F
4.8.3.2 Selection of Coolant
Use Table 4.8-1 to specify the coolant (also see references 3 and 7):
Coolant =
In evaluating a permit application, use Table 4.8-1 to determine if the applicant's values for TCon,
coolant type, and Tcooi.i are appropriate:
Tcon= F
Coolant type =
Tcool.i =
If they are appropriate, proceed with the calculations. Otherwise, reject the proposed design.
4.8.3.3 Condenser Heat Load
1. a. Use Equation 4.8-2 to calculate HAPe,m:
HAPe,m = (Qe/392) HAPe x 10'6 4.8-2
HAPe.m = Ib-moles/min
b. Use Equation 4.8-3 to calculate HAP0,m:
C.8-2
-------
HAP0>m - (Qe/392)[1 -(HAPe X 1 (T6)][PvaPor/(Pe - Pvapor)] 4.8-3
Where: Pvapor = Ppartial
HAPo.m = Ib-moles/min
c. Use Equation 4.8-4 to calculate HAPcon:
HAPcon — HAPe,m • HAPo,m
HAPcon = ' Ib-moles/min 4.8-4
2. a. Calculate heat of vaporization (AH) of the HAP from the slope of the
graph [In(Pvapor)] vs [1/(TCon + 460)] for the Pvapor and Tcon ranges of
interest (Fig. 4.8-2).
. AH = Btu/lb-mole
b. Use Equation 4.8-5 to calculate Hcon;
Hcon = HAPcon[DH+CpHAP (Te - Icon)] 4.8-5
where CPHAP can be obtained from References 3 and 7, or Table C.8-1.
Hcon = Btu/min
c. Use Equation 4.8-6 to calculate Hnoncon:
Hnoncon = [(Qe/392)-HAPe,m] Cpair (Te - Icon) 4.8-6
where Cpair can be obtained from References 3 and 7, or Table C.8-1.
Hnoncon = Btu/min
:,.... 3. a. Use Equation 4.8-7 to calculate Hioad:
Hioad = 1.1 X 60 (Hcon+ Hnoneon) 4.8-7
Hioad = BtU/hr
4.8.3.4 Condenser Size
Use Equation 4.8-9 to calculate Aeon:
Aeon = Hioad/U AT|_M 4.8-9
where TLM is calculated as follows:
ATtM = [(Te - Tcool,o) - (Toon - Tcoo!,i)]/ln[(Te - Tcooi,o)/(Tcon - Tcool,))]
C.8-3
-------
Assume: Tcooy = TCon-15, and Tcooi.o - Tcooi.i = 25°F
TcooU- _ °F
Tcool.o = _ °F
ATtM = _ °F
Assume: U = 20 Btu/hr-ft2-°F (if no other estimate is available),
Aeon = _ ft
Table C.8-1 Average Specific Heats of Vaporsa'b
Average Specific Heat, Cp (Btu/scf-°F)c'd
Temperature
(°F) _ Air HaO Oz N2 CO COa Ha CH4 C2H4 C2H6
77 0.0180 0.0207 0.0181 0.0180 0.0180 0.0230 0.0178 0.0221 0.0270 0.0326
212 0.0180 0.0209 0.0183 0.0180 0.0180 0.0239 0.0179 0.0232 0.0293 0.0356
392 0.0181 0.0211 0.0186 0.0181 0.0181 0.0251 0.0180 0.0249 0.0324 0.0395
572 0.0183 0.0212 0.0188 0.0182 0.0183 0.0261 0.0180 0.0266 0.0353 0.0432
752 0.0185 0.0217 0.0191 0.0183 0.0184 0.0270 0.0180 0.0283 0.0379 0.0468
932 0.0187 0.0221 0,0194 0.0185 0.0186 0.0278 0.0181 0.0301 0.0403 0.0501
1,112 0.0189 0.0224 0.0197 0.0187 0.0188 0.0286 0.0181 0.0317 0.0425 0.0532
1,292 0.0191 0.0228 0.0199 0.0189 0.0190 0.0292 0.0182 0.0333 0.0445 0.0560
1,472 0.0192 0.0232 0.0201 0.0190 0.0192 0.0298 0.0182 0.0348 0.0464 0.0587
1,652 0.0194 0.0235 0.0203 0.0192 0.0194 0.0303 0.0183 0.0363 0.0481 0.0612
1,832 0.0196 0.0239 0.0205 0.0194 0.0196 0.0308 0.0184 0.0376 0.0497 0.0635
2,012 0.0198 0.0243 0.0207 0.0196 0.0198 0.0313 0.0185 0.0389 0.0512 0.0656
2,192 0.0199 0.0246 0.0208 0.0197 0.0199 0.0317 0.0186 0.0400 0.0525 0.0676
"Source: Reference 3 (see Section 4.8.6).
bAverage for the temperature interval 77°F and the specified temperature.
°Based on 70°F and 1 atm.
convert to Btu/lb-°F basis, multiply by 392 and divide by the molecular weight of the compound. To convert to
Btu/lb-moI°F, multiply by 392.
C.8-4
-------
4.8.3.5 Coolant Flow Rate
Use Equation 4.8-10 to calculate Qcooiant:
Qcoolant = H|oad/[Cpcoolant (Tcx)ol,o - TosoU)] , 4.8-10
The value for Cpcooiant for different coolants can be obtained from References 3 or 7. If water is
used as the coolant, Cpwater can be taken as 1 Btu/lb-°F.
CpCoolant = _ _ BtU/ib-°F
Qcooiant = _ Ib/hr
4.8.3.6 Refrigeration Capacity
Use Equation 4.8-1 1 to calculate Ref :
= Hioad/1 2,000 . 4.8-11
Ref = _ _ _tons
4.8.3.7 Recovered Product
Use Equation 4.8-12 to calculcate Qrec:
Qrec = 60 x HAPcon x MWHAP 4.8-12
Qrec = _ Ib/hr
4.8.4 Evaluation of Permit Application
Compare the results from the calculations and the values supplied by the permit applicant using
Table 4.8-2. If the calculated values Toon, coolant type, Qcooiant, Aeon, Ref, and Qrec are different
from the reported values for these variables, the differences may be due to the assumptions
involved in the calculations. Discuss the details of the proposed design with the permit applicant.
If the calculated values agree with the reported values, then the design and operation of the
proposed condenser system may be considered appropriate based on the assumptions made
in this handbook. : ' -
4.8,5 Capital and Annual Costs of Condensers
4.8.5.1 Capital Costs of Condensers
The capital cost of a condenser system is composed of the purchased equipment cost (PEC)
and the direct and indirect installation costs.
Figure 4.8-3 or 4.8-4 can be used to estimate the cost of a chilled water condenser. The
equipment cost is the sum of the condenser cost obtained from Figure 4.8-3 or 4.8-4 and the
auxiliary equipment cost obtained from Section 4.1 2. The PEC is then estimated using the factors
given in Table 4.8-3.
C.8-5
-------
Table 4.8-2 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Condensation
Calculated Reported
Value Value
Continuous monitoring of exit stream
temperature
Condensation temperature, Tcon ...
Coolant type
Coolant flow rate, Qcooiant
Condenser surface area, Aeon
Refrigeration capacity, Ref
Recovered product, Qrec
Condenser cost = $
Auxiliary equipment cost = $
Equipment cost, EC - Condenser cost + Auxiliary equipment cost
Equipment cost, EC = $
The Purchased Equipment Cost, PEC, is estimated as follows:
PEC = EC + Instrumentation & Sales tax & Freight
PEC = $
The total capital cost (TCC) is estimated using the PEC and the factors given in Table 4.8-3.
TCC = 1.74 PEC + SP + Bldg.
TCC = $
If a condenser needs a refrigerant system, the escalated total capital cost of the refrigerant
system obtained from Figure 4.8-4 is added to the TCC obtained above.
4.8.5.2 Annual Costs for Condensers
The annual cost for a condenser system consists of direct and indirect annual costs minus
recovery credits.
C.8-6
-------
Direct Annual Costs
Direct annual costs consist of utilities, operating labor, and maintenance labor.
The electricity cost is estimated using the cost factor given in Table 4.8-5 and the annual
electricity usage (Fp), calculated using Equation 4.8-13.
Fp = 1.81 x 1CT4 (Qe,a) (P)(HRS) 4.8-13
where: Qe,a = Qe (Te + 460)/537
Fp = _kWh/yr
Annual electricity cost = $0.059 (Fp)
Annual electricity cost = $
The cost of replacing the refrigerant will vary, but is typically low. For purposes of this
report, this cost is assumed to equal zero.
The operating labor cost is estimated using a labor requirement of 0.5 hr/shift and the
labor rate given in Table 4.8-5. Supervisory costs are assumed to equal 15 percent of
operating labor costs.
Operating labor = [(0.5 hr/shift)/{8 hr/shift)](HRS) ($12.96/hr)
Operating labor = $
Supervisory costs = 0.15 (Operating labor)
Supervisory costs = $ .
Maintenance labor costs are estimated using a labor requirement of 0.5 hr/shift and the
wage rate given in Table 4.8-5. Maintenance materials are assumed to be 100 percent
of this cost.
Maintenance labor = [(0.5 hr/shift)/(8 hr/shift)](HRS) ($14.26/hr)
Maintenance labor $
Maintenance materials = 1.0 (Maintenance labor)
Maintenance materials = $
Total Direct Costs = $
C.8-7
-------
Indirect Costs
These costs are obtained from the factors provided in Table 4.8-5.
Overhead = $
Administrative = $ r
Insurance = $
Property tax = $
Capital recovery = $ .
Total Indirect Costs = $
Recovery credits may be significant, but are highly variable and depend on site specific
conditions. The reader will need to obtain this credit on a site specific basis.
TAG = Total Direct Costs + Total Indirect Costs - Recovery Credits
TAC = $ ,
C.8-8
-------
Appendix C.9
Calculation Sheet lor Fabric Filters
4.9.1 Data Required
HAP emission stream characteristics:
1 . Flow rate, Qe,a = ................................. acfm
2. Moisture content, Me = _ • % (vol)
3. Temperature, Te = _ "f
4. Particle mean diameter, Dp = _
5. SOa content = __ _ _ ppm (vol)
6. Particulate content = _ grains/scf
7, HAP content = _ _ __ % (mass)
In the case of a permit review, the following data should be supplied by the applicant:
1. Filter fabric material _
2. Cleaning method (mechanical shaking, reverse air, pulse-jet) _
3. Air-to-cloth ratio _ fl/min
4, Baghouse construction configuration (open pressure, closed pressure, closed
suction) _
5. System pressure drop range . in, HaO
4.9.2 Pretreatment Considerations
If emission stream temperature is not from 50° to 100°F above the dew point, pretreatment is
necessary (see Section 3.3.1 and Appendix B.1). Pretreatment will cause two of the pertinent
emission stream characteristics to change; list the new values below.
1 . Maximum flow rate at actual conditions, Qe,a = _ , _ acfm
2. Temperature, T^ = _ "F
4.9.3 Fabric Filter System Design Variables
1 . Fabric Type(s) (use Table 4.9-1):
a.
C-9.1
-------
c. __ _ __
2. Cleaning Method(s) (Section 4.9.3.2):
a. _
b. _
3. Air-to-cloth ratio (Table 4.9-3) _ ft/min
4. Net cloth area, Anc:
Anc = Qe,a / (A/C ratio) 4.9-1
where:
Anc = net cloth area, ft2
Q6ia = maximum flow rate at actual conditions, acfm
where:
Qe,a = Qe (Te + 460)/537 (used if given Qe instead of Qe,a)
A/C ratio = air-to-cloth ratio, ft/min
Anc = _ ft2
5. Gross cloth area, Ate:
Ate = Anc x Factor
where:
Ate = gross cloth area, fl?
Factor = value from Table 4.9-4, dimensionless
Atc =
6. Baghouse configuration
C-9.2
-------
7. Materials of construction
4.9.4 Determination of Baghouse Operating Parameters
1. Collection efficiency, CE =
2. System pressure drop range in. HaO
4.9.S Evaluation of Permit Application
Using Table 4.9-5, compare the results from this section and the data supplied by the permit
applicant. As pointed out in the discussion on fabric filter design considerations, the basic design
parameters are generally selected without the involved, analytical approach that characterizes
many other control systems, such as an absorber system (Section 4.7). Therefore, in evaluating
the reasonableness of any system specifications on a permit application, the reviewer's main
task will be to examine each parameter in terms of its compatibility with the gas stream and
particulate conditions and with the other selected parameters. The following questions should
be asked:
1. is the temperature of the emission stream entering the baghouse within 50° to 100°F
above the stream dew point?
2. Is the selected fabric material compatible with the conditions of the emission stream;
that is, temperature and composition (see Table 4.9-1)?
3. Is the baghouse cleaning method compatible with the selected fabric material and
its construction; that is, material type and woven or felted construction (see Section
4.9.3.2 and Table 4.9-2)?
4. Will the selected cleaning mechanism provide the desired control?
5. Is the A/C ratio appropriate for the application; that is, type of dust and cleaning
method used (see Table 4.9-3)?
6. Are the values provided for the gas flow rate, A/C ratio, and net cloth area
consistent? The values can be checked with the following equation:
A/C ratio =
Anc
where:
A/C ratio = air-to-cloth ratio, ft/mln
Qe,a - emission stream flow rate at actual conditions, acfm
- net cloth area, ft2
C-9.3
-------
7. Is the baghouse configuration appropriate; that is, is it a negative-pressure bag-
house?
Table 4.9-5 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Fabric Filters
Calculated Reported
Value Value
Continuous monitoring of system pressure drop ...
Emission Stream Temp. Range
Selected Fabric Material
Baghouse Cleaning Method
Baghouse Configuration
4.9.6 Capital and Annual Costs of Fabric Filters
4.9.6.1 Total Capital Costs
The total capital cost (TCC) of a baghouse system includes the baghouse structure, cost of bags,
auxiliary equipment, and the direct and indirect installation costs.
Table 4.9-6 provides a guide that enables the reader to use the correct cost figure for a given
baghouse. Figures 4.9-1 through 4.9-6 are used to estimate the cost of the baghouse structure,
but do not include the bag cost. The bag cost (Ce) is estimated using Table 4.9-7 and the gross
cloth area calculated in Section 4.9.3.3.
The cost of auxiliary equipment is obtained from Section 4. 1 2.
The sum of the cost of the baghouse structure, bags and auxiliary equipment is the equipment
cost, EC. Table 4.9-8 contains the factors necessary to estimate the purchased equipment cost
(PEC) from the equipment cost:
Baghouse structure cost =$ __ _
Bag cost, CB = $ __
Auxiliary equipment cost = $
Equipment cost, EC = $ _
C-S.4
-------
Purchased equipment cost =1.18 (EC)
Purchased equipment cost, PEC = $
The factors given in Table 4.9-8 are used to estimate the total capital cost (TGG) of a baghouse
system.
TCC = 2.17 (PEC) + SP + Bldg.
- TCC = $ ^^___ '
4.9.6.2 Annual Costs of Fabric Filters
The annual cost of a fabric filter system consists of direct and indirect annual costs.
Direct Costs
The direct costs include utilities, operating labor, and maintenance costs.
v
The annual electricity cost is the product of the annual electricity usage, and the
electricity cost. The annual electricity usage is estimated using Equation 4.9-2.
Fp = 1.81x10-4(Qe,a)(P)(HRS) 4,9-2
Annual electricity cost = $0.059 (Fp)
Annual electricity cost = $
If a mechanical shaking is used, the additional power requirement (Pms) in kWh/yr
must be added to Fp to estimate the total annual electricity usage.
Pms = 6.05 x10-6(HRS) (Ate) 4.9-3
and, '
Annual electricity cost = $0.059 (Fp + Pms)
Annual electricity cost = $
Jf a pulse jet cleaning is used, the consumption of compressed air can be estimated
using a factor of 2 scfm compressed air/1,000 scfm emission stream. The equation
below can be used to estimate the yearly compressed air consumption.
Annual consumption = (Qe) (0.002)(60)(MRS) ft3/yr
The cost of compressed air is estimated using the factor provided in Table 4.9-10.
Annual compressed air cost = $0.16/1,000 scfm x (Annual consumption)
C-9.5
-------
Annual compressed air cost = $
Equation 4.9-4 is used to estimate the cost of replacement bags, CRB.
CRB = [Ce + CiJ CRFB = [CB + 0.14 AnC] 0.5762 4.9-4
The operating labor cost is estimated using a labor requirement of 3 hr/shift and the
wage rate given in Table 4,9-1 0. Supervisory costs are assumed to equal 1 5 percent
of the operating labor cost.
Operating labor = [(3 hr/shift)/(8 hr/shift)] (HRS) ($1 2.96/hr)
Operating labor = $ _ _
Supervisory costs = 0.15 (Operating labor)
Supervisory costs = $ _
Maintenance costs are estimated using a maintenance requirement of 1 hour per
shift and the wage rate given in Table 4.9-10. Maintenance materials are assumed
to equal 1 00 percent of this cost.
Maintenance labor = [(1 hr/shift)/(8 hr/shift)] (HRS) ($1 4.26/hr)
Maintenance labor = $ _
Maintenance materials = 1.0 (Maintenance labor)
Maintenance materials = $ __
Waste disposal costs should be estimated for each facility on a case-by-case basis,
as these costs vary widely. If no information can be found this cost can be estimated
using a factor of $200/ton for hazardous wastes,
Waste disposal costs = $ _ _
Total Direct Costs = $ _
Indirect Costs
These costs are obtained from the factors provided in Table 4.9-9.
Overhead = $ _
Property tax = $ __
C-9.6
-------
Administrative = $
Insurance = $ _
Capital recovery = $ _
Total Indirect Costs = $
Recovery credits may be significant, but are highly variable and depend on site
specific conditions. The reader will need to obtain this credit on a site specific basis,
TAG = Total Direct Costs + Total Indirect Costs - Recovery Credits
TAC = $
C-9.7
-------
Page Intentionally Blank
-------
Appendix C.10
Calculation Sheet for Electrostatic Precipitators
4.10.1 Data Required
HAP emission stream characteristics
1. Flow rate, Qe,a = acfm
2. Emission stream temperature, Te =.
3. Paniculate content = grains/scf
4. Moisture content, Me « % (vol)
5. HAP content = % (mass)
In case of a permit review, the following data should be supplied by the applicant. The design
considerations in this section will then be used to check the applicant's design.
1. Reported collection efficiency = . %
2. Reported drift velocity of particles = ft/sec
3. Reported collection plate area = ft2
4. System pressure drop = ,., in. HaO
4.10.2 Pretreatment of Emission Stream
If the emission stream temperature is not from 50° to 100°F above the dew point, pretreatment
is necessary (see Section 3.3.1 and Appendix B.1). Pretreatment will cause two of the pertinent
emission stream characteristics to change; list the new values below.
1. Maximum flow rate at actual conditions, Qe,a = acfm
2. Temperature, Te = °F
4.10.3 ESP Design Variables
4.10.3.1 Collection Plate Area and Collection Efficiency
Collection plate area is a function of the emission stream flow rate, drift velocity of the particles
(Table 4-17), and desired control efficiency. The variables are related using Equation 4.10-1:
-In(1-CE)/Ud(O.G6) 4.10-1
C.10-1
-------
where:
SCA = specific collection plate area ft2/1! ,000 acfm
Ud = drift velocity of particles, ft/sec (see Tables 4.10-1 through 4.10-3)
CE = required collection efficiency, decimal fraction
SCA = ft2
4.10.4 Evaluation of Permit Application
Using Table 4.10-4, compare the results from this section and the data supplied by the permit
applicant. In evaluating the reasonableness of ESP design specifications in a permit application,
the main task will be to examine each parameter in terms of its capability with the gas stream
conditions.
If the applicant's collection plate area is less than the calculated area, the discrepancy will most
likely be the selected drift velocity. Further discussions with the permit applicant are recom-
mended to evaluate the design assumptions and to reconcile any apparent discrepancies.
Table 4.10-4 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for ESPs
Calculated Reported
Parameter Value Value
Continuous monitoring of plate voltage
and current
Drift velocity of particles, Ud
Collection efficiency, CE ... ...
Collection plate area, Ap
4.10,5 Capital and Annual Costs of ESP Systems
4.10.5.1 ESP Capital Costs
The capital cost of an ESP system consists of the purchased equipment costs and the direct
and indirect installation cost factors given in Table 4.10-5.
The purchased equipment cost, PEC, is composed of equipment costs (EC) and the cost of
instrumentation, sales tax, and freight. The equipment cost is the sum of the ESP structure cost
C.10-2
-------
obtained from Figure 4.10-2 or 4.10-3 and the auxiliary cost obtained from Section 4.12. Tables
4.10-6 and 4.10-7 are used to adjust the ESP cost obtained from Figure 4.10-2 or 4.10-3 to
specific conditions.
1. ESP cost (from Figure 4.10-2 or 4.10-3)=$
2. Cost factor from Table 4.10-6 = ___^_ (default = 1.0)
3. Cost factor from Table 4.10-7 = (default = 1.0)
Total ESP cost = (1) x (2) x (3)
Total ESP cost = $
4. Equipment cost (EC) = Total ESP cost •+ auxiliary equipment cost
Equipment cost (EC) = $
5. Purchased equipment cost, PEC = 1.18 x EC (see Table 4.10-5)
Purchased equipment cost, PEC = $
The factors given in Table 4.10-5 are used to estimate the total capital cost (TCC) of an ESP
system.
TCC = 2.24 PEC + SP + Bldg.
TCC = $
4.10.5.2 Annual Costs for ESP
The annual costs of an ESP system consist of direct and indirect annual costs.
Direct Costs
The direct costs include electricity, operating labor, maintenance costs, plus, if
applicable, water costs, wastewater treatment costs, and SOs conditioning costs.
The annual electricity cost is the product of the annual electricity usage and the
electricity cost factor given in Table 4.10-9. The annual electricity usage is estimated
using Equation 4.10-2.
FP = 1.81 x 1Q-4 (Qea) (P) (MRS) 4.10-2
where:
Fp = annual electricity usage, kWh/yr
Qe,a = emission stream flowrate, acfm
C.10-3
-------
P = pressure drop, in. HaO (default = 5 in. HaO)
HRS = annual operating hours, hr/yr
Fp = kWh/yr
For wet ESPs the pump power (Pp) is estimated using Equation 4.10-3.
Pp = 0.746 (Qi_) (Z)(Sg) (HRS)/(3960n) 4.10-3
where:
Pp = Pump power requirements, kWh/yr
QL = Liquid flow rate, gal/min
Z = fluid head, ft
Sg = specific gravity of fluid relative to water at 779F, 1 atm
HRS = annual operating hours, hr/yr
n = combined pump-motor efficiency, fraction
Pp = kWh/yr
This power requirement is multiplied by the electricity cost factor to obtain annual
pump power costs.
For TR sets and motor driven or electromagnetic rapper systems the power
requirement (OP) is estimated using Equation 4.10-4.
OP = 1.94 x 1Q-3 (Ap) (HRS) 4.10-4
where:
OP = annual ESP operating power, kWh/yr
Ap = collection plate area, ft2
HRS = annual operating hours, hr/yr
OP = kWh/hr
This power requirement is multiplied by the electricity cost factor to obtain annual
costs.
For two stage ESPs, power requirements (Pis) are assumed to equal 40 W/kaefm.
C.10-4
-------
Pis = 40 (Qe,a X 0.06) (HRS)/1,000
_ kWh/yr
This value for PTS is multiplied by the electricity cost factor given in Table 4.1 0-8 to
obtain annual costs.
For wet ESPs, the consumption of water (Wcr) is estimated at 5 gal/min kacfm for
single stage ESPs, and 16 gal/min kacfm for two stage ESPs.
Single Stage ESPs:
WCT = 5 (Qe,a x 0.06} (HRS)
WCT = gal/yr
Two Stage ESPs:
WCT = 1 6 (Qe,a x 0.06) (HRS)
WCT = _ gal/yr
The value obtained for WCT is multiplied by the cost factor given in Table 4.10-8 to
obtain annual costs.
The cost of an SOs conditioning system for a large (2.6 x-106 acfm) ESP ranges
from $1.61/106 ft gas processed to $2.30/1 06 ft gas processed. Taking the
midpoint,
Cost S03 = $1. 96/1 06 ft3 (Qe,a)(60)(HRS) , /:
COStSO3 = $ _ , ,: - •
The operating labor cost is estimated using a labor requirement of 0.5 hr/shift and
the wage rate given in Table 4.10-8. Supervisory costs are assumed equal to 15
percent of the operating labor cost.
Operating labor = [(0.5 hr/shift)/(8 hr/shift)](HRS)($12.96/hr)
Operating labor - $ r ,
Operating costs = 0.15 (Operating labor)
Operating costs = $ _,_
Maintenance costs (MC) are estimated from Equation 4.10-5.
MC -0101" (PEC) + Labor cost 4.10-5
C.10-5
-------
where:
PEC = purchased equipment cost, $
Labor cost = $4,125, if Ap < 50,000 ft2
Labor cost = $0.0825 Ap, if Ap ;> 50,000 ft2
MC = $
Waste disposal costs are estimated at $200/ton hazardous waste. The equation
below can be used to estimate this cost.
Waste disposal costs per year = (Paniculate content in gr/ft3)
(lb/7,OOOgr)(Qe,a)(60)(HRS)($200)/2000
Waste disposal cost per year = $
Total Direct Costs = $
Indirect Costs
These costs are obtained from the factors provided in Table 4.10-8.
Overhead = $
Administrative = $
Property tax = $
Insurance = $
Capital recovery = $
Total Indirect Costs = $
TAG - Total Direct Costs + Total Indirect Costs
TAC-$
C.10-6
-------
Appendix C.11
Calculation Sheet for Venturi Scrubbers
4.11.1 Data Required
HAP emission stream characteristics:
1. Flow rate, Qe,a = acfm
2. Temperature, Te = op
3. Moisture content, Me = %
4. Required collection efficiency, CE = %
5. Particle mean diameter, Dp = |im
6. Paniculate content = grains/scf
7. HAP content = % (mass)
In the case of a permit review, the following data should be supplied by the applicant:
1. Reported pressure drop across venturi, Pv = ' in. HaO
2. An applicable performance curve for the venturi scrubber
3. Reported collection efficiency, CE = %
4.11.2 Pretreatment of Emission Stream
If the emission stream temperature is not from 50° to 100°F above the dew point, pretreatment
is necessary (see Section 3.3.1 and Appendix B.1}. Pretreatment will cause two of the pertinent
emission stream characteristics to change; list the new values below.
1. Maximum flow rate at actual conditions, Qe,a = acfm
2. Temperature, Te = °F
4.11.3 Venturi Scrubber Design Variables
4.11.3.1 Venturi Scrubber Pressure Drop
The pressure drop across the venturi (Pv) can be estimated through the use of a venturi scrubber
performance curve (Figure 4.11-1) and known values for the required collection efficiency (CE)
and the particle mean diameter (Dp).
Pv = in.
C.11-1
-------
If the estimated Pv is greater than 80 in HaO, assume that the venturi scrubber cannot achieve
the desired control efficiency,
4.11.3.2 Materials of Construction
Select the proper material of construction by contacting a vendor, or as a lesser alternative, by
using Table 4.11-2.
Material of construction
4.11.4 Sizing of Venturi Scrubber
Some performance curves and cost curves are based on the saturated gas flow rate (Qe,s). If
Qe,s is needed, it can be calculated as follows:
Qe,s = Qe,a x (Te,s + 460)/(Te + 460) + Qw 4.11 -1
where:
Qe,s = saturated emission stream flow rate, acfm
Te,s = temperature of the saturated emission stream, °F
Qw = volume of water added, ft3/min
Use Figure 4.11-2 to determine Te,s; the moisture content of the emission stream (Me) must be
in units of Ibs HsO/lbs dry air.
Convert Me (% vol) to units of Ibs HaO/lbs dry air, decimal fraction:
(Me/100) x (18/29) = Ib HaO/lb dry air
From Figure 4.11 -2 and Section 4.11.4:
Te,s = °F
Qw= (1-Lw,a)(De)(Qela)(Lw,s- Lw,a)(1/Dw)
Qw = ' ft3/min
Qe,s = acfm
4,11.5 Evaluation of Permit Application
Using Table 4.11-3, compare the results of this section and the data supplied by the permit
applicant. Compare the estimated Pv and the reported pressure drop across the venturi, as
supplied by the permit applicant.
C.11-2
-------
if the estimated and reported values differ, the differences may be due to the applicant's use of
another performance chart, or a discrepancy between the required and reported collection
efficiencies. Discuss the details of the design and operation of the system with the applicant, if
there are no differences between the estimated and reported values for Pv, the design and
operation of the system can be considered appropriate based on the assumptions employed in
this handbook.
Table 4.11-3 Comparison of Calculated Values and Values Supplied by the Permit
Applicant for Venturl Scrubbers
Calculated Reported
Value Value
Particle Mean Diameter, Dp ... ...
Collection efficiency, CE
Pressure drop across venturi, Pv ...
4.11.6 Capital and Annual Costs of Venturi Scrubbers
4.11.6.1 Capital Costs of Venturi Scrubbers
The capital cost of a venturi scrubber system consists of the purchased equipment costs and
the direct and indirect installation costs.
The purchased equipment cost (PEC) is composed of equipment costs and the cost of sales tax
and freight. The equipment cost (EC) is the sum of the scrubber cost obtained from Table 4.11 -4
and the auxiliary equipment cost (Aex), obtained from Section 4.12. Table 4.11-5 provides the
factors necessary to estimate the PEC
1. Venturi scrubber cost, VSC (Table 4.11-4)
*
VSC - $ x 2,3 or 3.2 (if applicable)
Note: If 304L stainless steel is used, multiple VSC by 2.3, or if 316L stainless
steel is used, multiple VSC by 3.2, to obtain the corrected VSC.
2. Equipment cost, EC = VSC + Aex
. EC = $ _ .
3. Purchased equipment cost, PEC = 1.08 EC
PEC • $
C.11-3
-------
The factors given in Table 4.1 1-5 are used to estimate the total capital cost, TCC.
TCC-1.91 PEC + SP + Bldg.
TCC»$ _
4.1 1 .6.2 Annual-Costs for Venturi Scrubbers
The annual cost of a venturi scrubber system consists of direct and indirect annual costs.
Direct Costs
The direct costs include electricity, water, operating labor and maintenance costs.
The annual electricity consumption is estimated using Equation 4.1 1-2.
FP = 1 .81 x 1 CT4 (Qe,a)(P)(HRS) 4.1 1 -2
Fp = . _ kWh/yr
This value is multiplied by the cost of electricity to obtain annual electricity costs,
AEC.
AEC = 0.059 (Fp)
AEC = $ _
The water consumption for a venturi scrubber is estimated from Equation 4.11-3.
WR = 0.60 (Qe,a)(HRS) 4.11-3
WR - gal/yr
Operating costs
Operating labor costs = [(2 hr/shift)/(8 hr/sh!ft)](HRS)($12.96/hr)
Operating labor costs = $
Supervisory costs = 0.15 (Operating labor costs)
Supervisory costs = $
Maintenance costs
Maintenance labor costs »[{1 hr/shift)/(8 hr/shift)](HRS)($14.26/hr)
Maintenance labor costs = $
C.11-4
-------
Maintenance materials = 1.0 (Maintenance labor costs)
Maintenance materials = $ '
Total Direct Costs = $
Indirect Annual Costs
These costs are obtained from the factors provided in Table 4.11-7.
Overhead =$
Administrative =$
Property tax = $
Insurance = $
Capita! recovery = $ .
Total Indirect Costs = $
Total Annual Costs = Total Direct Costs + Total indirect Costs
Total Annual Costs = $ ,
C.11-5
-------
Page Intentionally Blank
-------
Appendix C.12
Calculation Sheet for Auxiliary Equipment
Auxiliary equipment is defined to include fans, ductwork, stacks, dampers, and cyclones (if
necessary).
C.12.1 Fan Purchase Cost
Equation 4.12-1 provides the cost of a fan system including a motor and starter.
Pfan = 42.3dfan120 4.12-1
Plan = $
Equation 4.12-2 provides the cost of a FRP fan system without motor or starter.
Plan = 53.7 dfan1'38 4.12-2
Pfan = $ _
Equation 4. 1 2-3 gives the cost of a carbon steel fan without motor or starter. Consult Table 4. 1 2-2
for values of a and b.
= adfanbf 4.12-3
Pfan =
Equation 4.12-4 provides the cost of a motor and starter for a required motor horsepower
between 1 and 7.5 hp. This cost is added to the cost obtained from Equation 4.12-2 or 4.12-3.
Pmotor - 235 hp°'256 4.12-4
Pmotor = $
For a horsepower requirement between 7.5 and 150 hp, use Equation 4.12-5. This cost is added
to the cost obtained from Equation 4.12-2 or 4.2-3.
Pmotor = 94.7 hp°'821 4.12-5
Pmotor = $
Pfan = $
C.12.2 Ductwork Purchase Costs
The cost of ductwork is calculated assuming a duct velocity (Uduct) of 2000 ft/mln. Use Equation
4.12-6 to obtain the duct diameter requirement.
C.12-1
-------
dduct = 12 [(4/n)(Qe,a/Uduct)]a5 - 0.3028 (Qe.af5 4.12-6
dduct = in
Once this value is obtained, use Equation 4.12-7 for PVC ductwork with a diameter between 6
and 24 inches. Consult Section 4.12.2 for values of ad and bd or Equation 4.12-8 for the cost of
FRP ductwork with a diameter between 2 and 5 feet.
PPVCD - ad dduct bd 4.12-7
PPVCD = $/ft length
PFRPD= 24 Dduct 4.12-8
PFRPD - $/ft length
C.12.3 Stack Purchase Cost
For small FRP stacks, estimate the stack cost as 150 percent of the corresponding duct cost
obtained in Section 4.12.2
Stack Cost = 1.5 (PFRPD)
Stack Cost = $/ft length
For taller stacks (i.e., between 200 and 600 feet) use Equation 4.12-9 to estimate the stack cost.
Obtain parameters a and b from Table 4.12-3.
Pstack = a Hstack b 4.12-9
Pstack = $
C.12.4 Damper Purchase Cost
Use Equation 4.12-10 to obtain the cost of backflow dampers or 4.12.-11 to obtain the cost of
two-way diverter valves.
Pdamp = 7.46 dduct0'944 ' 4.12-10
Pdamp = $
Pdivert - 4.84 dduct 15° 4.12-11
Pdlvert« $
C.12-2
-------
C.12.5 Cyclone Purchase Cost
Cyclones may be necessary for particulate emission streams if the streams contain large
particles. Equation 4.12-12 is used to obtain the cyclone cost while Equation 4.12-14 provides
the cost of a rotary air lock. The sum of these two costs yields the cyclone purchase cost.
Pcye = 6,520 A Cyc °J°31 4.12-12
Pcyc = $
Pral = 2,730 A Cyc °'°965 4.12-14
Prai = $ ________
Pcyc + Pral = $
C.12-3
------- |