&EPA
United States Office of Air Quality
Environmental Protection Planning and Standards
Agency Research Triangle Park NC 27711
Air
EPA-450/3-91-0123
FEBRUARY 1992
Procedures for
Establishing Emissions for
Early Reduction Compliance
Extensions
Volume 1 -- Synthetic Organic
Chemical Manufacturing,
Ethylene Oxide Sterilization, and
Chromium Electroplating
-------
EPA-450/3-91-012a
Procedures for Establishing
Emissions for Early
Reduction Compliance
Extensions
Volume 1
Emissions Standards Division
U S Environmental Protection Agency
Region 5, Library (PL-12J)
77 West Jackson Boulevard, ;utn rioor
Chicago, IL 60604-3590
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
February 1992
-------
TABLE OF CONTENTS
Section
INTRODUCTION 1-1
ESTABLISHING HAP EMISSIONS FROM SOCMI SOURCES
2.1 Process Vents 2-3
2.1.1 Acceptable Techniques for
Establishing HAP Emissions
from Process Vents 2-4
2.1.2 Documentation of HAP
Emissions from Process Vents ... 2-6
2.2 Storage Tanks 2-7
2.2.1 Acceptable Techniques for
Establishing HAP Emissions
from Fixed Roof Storage Tanks . . 2-8
2.2.2 Acceptable Techniques for
Establishing HAP Emissions
from Floating Roof Storage Tanks . 2-13
2.2.3 Documentation of HAP
Emissions from Storage Tanks ... 2-19
2.3 Equipment Leaks 2-30
2.3.1 Acceptable Techniques for
Establishing HAP Emissions
from Equipment Leaks 2-33
2.3.2 Documentation of HAP
Emissions from Equipment Leaks . . 2-37
2.4 Transfer Operations 2-38
2.4.1 Acceptable Techniques for
Establishing Emissions from
Transfer Operations 2-40
2.4.2 Documentation of HAP
Emissions from Loading Operations. 2-42
2.5 Wastewater Collection and Treatment ... 2-42
2.5.1 Acceptable Techniques for
Establishing HAP Emissions
from Wastewater Collection and
Treatment 2-44
2.5.2 Documentation of HAP Emissions
from Wastewater Sources 2-55
-------
TABLE OF CONTENTS (Concluded)
Section Page
3 ESTABLISHING CHROMIUM EMISSIONS FROM CHROMIUM
ELECTROPLATING OPERATIONS
3.1 Control Techniques/Performance 3-3
3.2 Acceptable Techniques for
Establishing Emissions 3-4
3.2.1 Direct Measurement 3-5
3.2.2 Emission Factors 3-5
3.3 Demonstration of Early Reduction 3-6
4 ETHYLENE OXIDE STERILIZATION
4.1 Techniques for Establishing Baseline
HAP Emissions 4-3
4.2 Techniques for Establishing 90% HAP
Emission Reduction 4-3
APPENDIX A: CALCULATION WORKSHEETS FOR ESTABLISHING
BASE YEAR AND POST-REDUCTION HAP EMISSIONS
FROM SOCMI SOURCES A-l
11
-------
LIST OF TABLES
Table Page
2-1 Equations for Estimating Fixed-Roof Storage
Tank Emissions 2-9
2-2 Average Storage Temperature (Ts) as a Function
of Tank Paint Color 2-10
2-3 Paint Factors for Fixed Roof Tanks 2-11
2-4 Equations for Estimating Internal Floating Roof
Storage Tank Emissions 2-14
2-5 Equations for Estimating External Floating Roof
Storage Tank Emissions 2-17
2-6 Typical Number of Columns as a Function of Tank
Diameter for Internal Floating Roof Tanks with
Column Supported Fixed Roofs 2-20
2-7 Deck Seam Length Factors (SD) for Typical
Deck Constructions for Internal Floating Roof
Tanks 2-21
2-8 Seal Related Factors for External Floating Roof
Tanks 2-22
2-9 Average Clingage Factors (C) (bbl/1,000 ft2). . . 2-23
2-10 Summary of Internal Floating Deck Fitting
Loss Factors (KF) and Typical Number of
Fittings (NF) 2-24
2-11 External Roof Fitting Loss Factors (Kfa, Kft))
and Typical Number of Roof Fittings (NF) . . . 2-26
2-12 Typical Number of Vacuum Breakers and
Roof Drains 2-28
2-13 Typical Number of External Floating Roof Legs. . 2-29
2-14 Leaking and Non-leaking Emission Factors For
Fugitive Emissions (kg/yr/source) 2-34
2-15 Stratified Emission Factors for Equipment
Leaks (kg/yr/source) 2-36
2-16 Saturation (S) Factors for Calculating Organic
Liquid Loading Losses 2-41
iii
-------
LIST OF TABLES (Concluded)
Table Page
2-17 Emission Sources in Wastewater Collection and
Treatment Systems .............. 2-45
2-18 Compound- specific Values of fe-j_ and fm± ..... 2-49
IV
-------
LIST OF FIGURES
Figure Page
4-1 The Sterilization Cycle 4-2
-------
1. INTRODUCTION
On June 13, 1991, EPA proposed "Regulations Governing
Compliance Extensions for Early Reductions of Hazardous Air
Pollutants" (56 FR 27338). The proposed rule (scheduled for
promulgation in March 1992) implements the provisions in Section
112(i)(5) of the Clean Air Act (Act), as amended in 1990. Those
provisions allow an existing source of hazardous air pollutant
emissions to obtain a six-year extension of compliance with an
emission standard promulgated pursuant to Section 112(d) of the
Act, if the source has achieved a reduction of 90 percent or more
of hazardous air pollutants emitted (95 percent or more for
particulate pollutants) by certain dates specified in the Act.
If a source is granted a compliance extension, an alternative
emission limitation will be established by permit to ensure
continued achievement of the 90 (95) percent reduction. The
proposed rule establishes requirements and procedures for source
owners and operators to follow in order to obtain compliance
extensions and for reviewing agencies to follow in evaluating
requests for extensions.
One requirement is that requests for a compliance extension
must be submitted to a reviewing agency (EPA or a State agency
with authority to implement this program) and must contain
documentation that the emission reduction has been achieved. To
document the reduction, the owner or operator must provide
emission data for base year and post-reduction emissions of
hazardous air pollutants emitted by the source. The proposed
rule establishes a presumption that source test results must be
used to satisfactorily document either base year or post-
reduction emissions. However, the rule also lists circumstances
under which an owner or operator would be allowed to use methods
other than source testing to document emissions for a source (for
example, methods employing engineering calculations, material
balances, or emission factors).
This document contains procedures for establishing emissions
1-1
-------
for three categories of sources. The three categories
covered in this document are synthetic organic chemical
manufacturing, chromium electroplating and chromic acid
anodizing, and ethylene oxide sterilization. Documents covering
additional industries which will be regulated under Section
112(d) of the Act will be issued periodically by EPA.
The intent of this document, and additional documents in
this series, is to provide methods for establishing emissions for
the purposes of the early reduction program, with an emphasis on
methods that can be used when source tests are not required.
Owners or operators may use this document as a guide to preparing
satisfactory emission reduction demonstrations for compliance
extension requests. However, it is not the intent of this
document to specify the only acceptable methods, other than
source tests, for establishing emissions from a source. EPA
recognizes that, depending on the circumstances, there may be
other ways of satisfactorily showing that hazardous air
pollutants have been controlled sufficiently to qualify for a
compliance extension, and owners or operators are not precluded
from using them. No matter what methods are used, the emissions
established for a source and submitted in a compliance extension
request will undergo review to determine whether they are
adequate for the purposes of the early reduction program.
1-2
-------
2.0 ESTABLISHING HAP EMISSIONS FROM SOCMI SOURCES
Air emission sources in the SOCMI industry can be divided
into five source types. These source types, along with a brief
description, are listed below:
Process Vent Emissions - Emissions from vented process
equipment such as reactors and distillation systems.
Storage Tank Emissions - Emissions from fixed roof and
floating roof storage tanks.
Equipment Leak Emissions - Emissions that occur due to
the escape of process materials through faulty seals in
pumps, valves, compressors, flanges and other
connectors, agitators, sample connections, and open-end
process lines.
Transfer Emissions - Emissions that occur when loading
product into tank trucks, rail cars, and marine
vessels.
Wastewater Collection and Treatment Emissions -
Emissions that result from the volatilization of
organic hazardous air pollutants (HAP) contained in
process wastewater streams.
This section describes the acceptable techniques for
establishing HAP emissions from each of these emission source
types. The basic approaches considered in prescribing acceptable
techniques for each source type included:
(1) Measurement - Calculations based on measured
concentration of the HAP in a waste stream and the flow
rate of the stream.
(2) Established EPA Protocols - Engineering calculation
methods presented in the US EPA publications,
Compilation of Air Pollutant Emission Factors
(EPA-AP-42) and Protocols for Generating Unit-Specific
Emission Estimates for Equipment Leaks of VOC and VHAP
(450/3-88-010). These publications provide engineering
calculation approaches for sources such as storage
tanks, transfer operations, and equipment leaks when
direct measurement is not feasible.
(3) Engineering Calculations - These are calculations based
on physical properties of the HAP, an understanding of
2-1
-------
the process, and accepted engineering relationships
such as the ideal gas law. The distinction between
this technique and (2) above is that the calculation
procedure has not been previously published as an
accepted EPA procedure for estimating source specific
emissions.
(4) Material Balance - A mass balance around the entire
process or piece of equipment. The amount of chemical
leaving the process equals the amount entering. If
input and product stream values are known and all
losses are to air, then air emissions can be computed
by difference. Any accumulation or depletion of the
HAP by reaction must be accounted for. In general,
material balances produce emission estimates with high
levels of uncertainty. However, in certain situations,
material balances can be used to produce accurate
emission estimates. Material balance can be used, for
example, where the HAP emitted is used as a process
solvent and is not involved in chemical reactions.
(5) Emission Factors - Calculations based on average
measured emissions at numerous facilities in the same
industry. Emission factors can be expressed as a ratio
of emissions to process throughput or an emission rate.
independent of throughput. The distinction between
this technique and (2) above is that the factor has not
been previously published as an accepted EPA procedure
for estimating source specific emissions.
The preferred method for determining HAP emissions is
measurement of the emission stream flow and HAP concentration
using published EPA Methods. However, measurement can be
expensive and even impractical in cases where there are large
numbers of individual sources, when emissions are intermittent
and highly variable or when the base year conditions no longer
exist at an emission point and cannot be duplicated. When direct
measurement is not feasible, the preferred approach is the use of
established EPA computation methods in AP-42 and Protocols for
Generating Unit-Specific Emission Estimates for Equipment Leaks
of VOC and VHAP (450/3-88-010). In most cases, it should be
feasible to establish HAP emissions data for a source using only
the first two approaches. However, certain situations may
require the use of engineering calculations; and in certain
situations material balances can be used to establish base year
2-2
-------
emissions. Specific guidance on the acceptable methodologies for
each source type are provided in the following subsections.
It is important to keep in mind that consistent or at least
compatible methodologies must be used to establish base year and
post-reduction emissions. The EPA will not allow credit for any
apparent reductions achieved by using incompatible techniques for
establishing base year and post-reduction emissions.
Additionally, EPA may require the applicant to demonstrate post-
reduction emissions using validated EPA protocols. In many cases
the validated EPA protocol may quantify more of the emissions
than the technique used to establish base year emissions.
The procedures prescribed in this section are intended for
continuous SOCMI processes. This is consistent with the
anticipated Hazardous Organic NESHAP (HON), the 112(d) standard
for continuous process chemical plants. The techniques
prescribed for process vents (Section 2.1) generally are not
applicable to batch processes. Another document to be released
by EPA in the near future will describe emission estimating
methods for batch process vents.
2.1 PROCESS VENTS
Process vents are the vapor exhaust devices on process
equipment in a manufacturing or processing operation. In most
chemical processes, impurities and inerts contained in the raw
materials necessitate the continuous or periodic venting of
noncondensible gases. When released to the atmosphere, volatile
HAP are carried from the process along with these noncondensible
gases.
Process vents are most commonly associated with reactors and
distillation systems. Direct observation of the piping and
instrument diagrams should indicate if process vents exist for a
given unit operation.
2-3
-------
2.1.1 Acceptable Techniques for Establishing HAP
Emissions From Process Vents.
The preferred technique for establishing HAP emissions from
process vents is direct measurement. The stream flow should be
determined using EPA Methods 1 through 4; and, when possible, the
HAP concentration should be determined using one of the EPA
Reference methods (prescribed in 40 CFR 60, Appendix A or 40 CFR
61, Appendix A) or an EPA Conditional Method. In many cases, a
validated EPA method will not exist for emissions of the subject
HAP from a specific source type. In such cases, the validation
protocol prescribed in EPA Method 301, Field Validation of
Emission Concentrations From Stationary Sources (450/4-90-015)
should be used to validate the method of choice.1
Establishing HAP emissions for process vents is basically
the same for all process vents, regardless of the unit operation..
The following parameters are required through direct measurement::
• Average annual volumetric flow rate of vent gas (during
operating hours),
• Vent gas discharge temperature,
• Average annual concentration of individual or aggregate
HAP,
• Operating hours per year of unit operation, and
• Molecular weight of individual or aggregate HAP.
Emissions of each HAP are calculated as follows:
EU = 2.54E-09 O C h MW P
T + 460
where,
By = uncontrolled HAP emission rate in Mg/yr,
Q = average annual vent stream flow rate in
cubic feet per minute,
C = average annual HAP concentration in ppm
volume,
2-4
-------
h = annual hours of operation,
T = vent stream discharge temperature in
degrees fahrenheit,
P = pressure at point of discharge in psia,
MW = HAP molecular weight, and
2.54E-09 = conversion factor to yield Mg/yr,
((60 min/hr)(Mg/2205 Ib)(10~6/R), where
R = 10.73 ft3.psia/lb-mol.°R)
The total HAP emissions are determined by summing the calculated
emissions of each HAP.
In cases where the vent emissions are intermittent or highly
variable, up-front calculations of annual average flow rate and
HAP concentration may be required.
In cases where there is a control device present and the
control device was present prior to 1987, the control device
efficiency should be accounted for in determining emissions. The
control device efficiency can be accounted for by: (1) measuring
the stream flow and concentration at the exit of the existing
control device, or (2) using the following expression:
EB = By (1 - eff/100)
where,
Eg = emissions in Mg/yr,
Ey = uncontrolled emissions in Mg/yr, and
eff = measured HAP control efficiency of the
control device.
The latter method actually requires three sets of sampling and
analysis (the individual vent stream, the control device inlet,
and the control device outlet), but may be necessary in
situations where the vent stream is combined with other vent
streams prior to control.
2-5
-------
In cases where the control efficiency differs for individual
HAP, it is necessary to perform the above calculations separately
for each HAP and then sum the emissions.
In certain situations, emissions from process vents can be
established by material balance, in lieu of sampling and
analysis. Material balances can provide accurate determinations
of emissions in cases where the HAP is used as a solvent, there
is no reaction of the HAP, and all losses are to the air or can
be accurately accounted for. In this case, the accuracy of
computed HAP emissions can be as accurate as the determination of
HAP usage. However, material balances are generally inaccurate
in applications outside of the case where the HAP is a process
solvent.
Calculations based on engineering principles are acceptable
only in situations where:
(1) No applicable EPA Reference Method, EPA Conditional
Method, or other source test method exists;
(2) It is not technically or economically feasible to
perform source tests;
(3) It can be demonstrated to the satisfaction of the
reviewing agency that the calculation will provide
emission estimates of accuracy comparable to any
applicable source test method;
(4) The base year conditions no longer exist and cannot be
reproduced and testing under the current conditions and
extrapolating will not produce results more accurate
than an estimate base on engineering principles; or
(5) The emissions from one or a set of emission points in
the source are small compared to total source emissions
and errors in estimating emissions from such points
will not have a significant effect on the accuracy of
estimated total emissions from the source.
The burden of adequately demonstrating one of these reasons for
not source testing is placed on the source owner or operator.
2.1.2 Documentation of HAP Emissions From Process Vents
2-6
-------
In establishing emissions, the following information should
be provided with the computed emission rate:
• Stream identification;
• Vent stream flow rate, method of measurement, and date
of measurement;
• Vent stream discharge temperature;
• Vent stream HAP concentration, method of measurement;
and date of measurement;
• A detailed description of measurement methods, if EPA
validated methods were not used;
• A statement that the measured flow and concentration
are believed to be representative of normal operation.
A form for reporting information used to establish emissions is
provided in Appendix A. In addition, detailed test data and
calibration data collected during sampling and analysis of the
stream should be available upon request.
2.2 STORAGE TANKS
Storage tanks for organic liquids are categorized into five
basic designs: fixed roof, external floating roof, internal
floating roof, variable vapor space, and pressure (high and low) .
Procedures for establishing emissions from fixed roof, external
floating roof, and internal floating roof tanks are provided in
this document.
Fixed roof tanks are designed as a cylindrical steel shell
with a permanent roof. The roof may be flat or shaped as a cone
or dome. Fixed roof tanks have a pressure/vacuum vent which
allows the tanks to operate at a slight internal pressure or
vacuum. However, with significant changes in temperature,
pressure, or liquid level, vapors are released through the vent.
For fixed roof tanks, the vapors emitted are categorized as
breathing losses and working losses. Breathing loss is the
expulsion of vapor from a tank through vapor expansion and
2-7
-------
contraction, which results from changes in temperature and
barometric pressure. Breathing loss occurs regardless of the
throughput of the tank. Working loss is due to emptying and
filling of the tank. As the tank is filled, the increased liquid
level in the tank compresses the vapor. When the pressure inside
the tank exceeds the relief pressure, the pressure/vacuum vent
releases vapor to the atmosphere. As the tank is emptied, air is
drawn into the tank and becomes saturated with organic vapor and
expands, thus exceeding the capacity of the vapor space. When
the internal pressure reaches the set pressure of the pressure/
vacuum vent, vapor emissions are released to the atmosphere.
Floating roof tanks have a floating deck which rests on the
surface of the organic liquid. The floating deck may be the roof
of the tank (external floating roof tanks) or the tank may have a
permanent roof with a floating deck inside (internal floating
roof). For most internal floating roof tanks, the space between
the floating deck and permanent roof is vented to the atmosphere
to prevent the possibility of explosion. The internal floating
deck either floats directly on the liquid surface or rests on
pontoons several inches above the liquid surface. The floating
deck restricts the vaporization of the organic liquid. However,
vaporization losses may occur from deck fittings, seams, and the
space between the deck and the tank wall.
2.2.1 Acceptable Techniques For Establishing HAP
Emissions From Fixed Roof Storage Tanks
The accepted technique for establishing HAP emissions from
fixed roof storage tanks is the computation technique prescribed
in AP-42.2 This computation technique, along with methods for
obtaining or estimating the necessary input parameters, is
provided in Tables 2-1 through 2-3. As an alternate, the
techniques prescribed in API publication 2518, Evaporative
Loss from Fixed from Fixed Roof Tanks (second edition^. may
be used to establish emissions from fixed roof tanks.4
Based on initial review, the techniques prescribed in
2-8
-------
TABLE 2-1. EQUATIONS FOR ESTIMATING FIXED-ROOF STORAGE TANK
EMISSIONS3
LT - LB + LW
LB = 1.02 X 10-5Mv. ( P—) °'68 Dl-73H0.51AT0.5FpCKc p.
1 PA - P P
% = 1.09 X 10~8 Mv.PiVNKNKc
where,
Lrp = total HAP emissions in Mg/yr,
LB = breathing loss emissions in Mg/yr,
I^ = working loss emissions in Mg/yr,
Mv. = molecular weight of HAP,
P = true vapor pressure of the material stored in psia
at the stored temperature (see Table 2-2),
P! = partial pressure of the specific HAP in psia,
PA = atmospheric pressure in psia,
D = tank diameter in feet,
H = average vapor space height in feet (use tank
specific values or an assumed value of one-half
the tank height),
T = average diurnal temperature change in °F (20°F can
be used as a typical value),
Fp = dimensionless paint factor from Table 2-3,
C = dimensionless tank diameter factor:
C = 1 for diameter > 30 feet
C = 0.0771D-0.0013D2-0.1334 for dia. < 30 feet
Kc = product factor = 1.0 for volatile organic HAPs,
V = tank capacity in gallons
N = number of turnovers per year,
KN = dimensionless turnover factor:
KN = 180 + N for turnovers > 36
6N
KN = 1 for turnovers £ 36
aReferences 2 and 3.
2-9
-------
TABLE 2-2. AVERAGE STORAGE TEMPERATURE (Ts)
AS A FUNCTION OF TANK PAINT COLOR3
Average storage temperature,
Tank Color Ts
White TAb + 0
Aluminum TA + 2.5
Gray TA + 3.5
Black TA + 5.0
aReference 2.
"TA is the average annual ambient temperature in degrees
Fahrenheit.
2-10
-------
TABLE 2-3. PAINT FACTORS FOR FIXED ROOF TANKS3
Paint factors (Fp)
Tank color
Roof
Shell
Paint condition
Good Poor
White
Aluminum (specular)
White
Aluminum (specular)
White
Aluminum (diffuse)
White
Light gray
Medium gray
White 1.00
White 1.04
Aluminum (specular) 1.16
Aluminum (specular 1.20
Aluminum (diffuse) 1.30
Aluminum (diffuse) 1.39
Gray 1.30
Light gray 1.33
Medium gray 1.46
1.15
1.18
1.24
1.29
1.38
1.46
1.38
1.44b
1.58b
aReference 3.
^Estimated from the ratios of the seven preceding paint factors,
2-11
-------
API publication 2518 appear to be more accurate for materials
with low vapor pressures.
Equations for calculating losses from fixed roof tanks are
provided in Table 2-1. These equations are from AP-42, but have
been modified slightly to compute compound specific emissions
when the HAP is part of a mixture. The equations from AP-42 have
simply been multiplied by M^Pi/MyP, where Mv. is the molecular
weight of the HAP, P^ is the partial pressure of the specific
HAP, Mv is the molecular weight of the mixture stored in the
tank, and P is the vapor pressure of the stored mixture. The
equations presented in Table 2-1 represent the product of this
calculation, after the cancellation of like terms.
In cases where the HAP is part of a mixture, the vapor
pressure of the material stored must be: (l) measured; or
(2) calculated by summing the partial pressures of constituents.
Raoult's Law and/or Henry's Law, as applicable, are recommended
for calculating the partial pressure of constituents in a
mixture.
The equations presented in Table 2-1 can be used to
establish emissions from horizontal tanks by calculating an
effective diameter for substitution in the breathing loss
equation as follows:
De ~ LD/0.785
where:
De = effective tank diameter (ft);
L = length of tank (ft); and
D = actual diameter of tank (ft).
For horizontal tanks, half of the diameter should be used as the
average vapor space height.
For underground tanks, assume that no breathing losses occur
because the insulating nature of the earth limits the diurnal
2-12
-------
temperature change. No modification to the working loss equation
is necessary for either above-ground or underground horizontal
tanks.
2.2.2 Acceptable Techniques For Establishing HAP
Emissions From Floating Roof Storage Tanks
The preferred technique for establishing HAP emissions from
floating roof storage tanks are the computation techniques
presented in Tables 2-4 and 2-5. These equations are essentially
the techniques prescribed in AP-42, with two additions. First
the equations have been modified slightly to compute compound
specific emissions when the HAP is part of a mixture. The
equations from AP-42 have been multiplied by Mv.Pi/MvP to yield
emissions of a specific HAP. Secondly, fitting loss calculations
for external floating roofs have been added to the procedure.
This additional component of the external floating roof
calculations was obtained from a study recently completed by the
American Petroleum Institute, Evaporative Loss From External
Floating-Roof Tanks (API Publication 2517).5
The equations provided in this section are applicable only
to freely vented internal floating roof tanks and external
floating roof tanks. The equations are not intended to be used
in the following applications: to estimate losses from closed
internal floating roof tanks (tanks vented only through a
pressure-vacuum vent); or to estimate losses from tanks in which
the materials used in the seal system and/or deck construction
are either deteriorated or significantly permeated by the stored
liquid.6
Some notes and guidance for obtaining the less obvious
inputs are provided in the following paragraphs.
Welded roofs. Floating roof tank emissions are the sum of
rim seal, withdrawal, deck fitting, and deck seam losses.
However, it should be noted that external floating roof tanks and
welded internal floating roofs do not have deck seam losses.
There are no procedures in AP-42 for estimating emissions from
2-13
-------
TABLE 2-4. EQUATIONS FOR ESTIMATING INTERNAL FLOATING ROOF
STORAGE TANK EMISSIONS3
Lrp - LW + LR + Lp + LQ
where :
LT = total loss of HAP (Mg/yr)
Lw = withdrawal loss (Mg/yr)
= (0.943) 0 C WL [1+(Vc}] MviPj
(2205) D D Mv P
p
LR = rim seal loss (Mg/yr) = (KRD) P* Mv. Kc _ i_
1 2205 P
p
LF = fitting loss (Mg/yr) = (FF) P* Mv. Kc
1
2205 P
LD = deck seam loss (Mg/yr) = (SD KD D2) P* Mv. Kc Pj
1 2205 P
where :
D = tank diameter (ft)
Q = product average throughput (bbl/yr)
C = product withdrawal shell clingage factor (bbl/103
ft2) , see Table 2-9
WL = density of the product (Ib/gal)
Nc = number of columns (dimensionless)
Fc = effective column diameter (ft)
KR = rim seal loss factor (Ib mole/ ft yr) that for an
average fitting seal is as follows:
2-14
-------
TABLE 2-4. EQUATIONS FOR ESTIMATING INTERNAL FLOATING ROOF
STORAGE TANK EMISSIONS (CONTINUED)
Seal system description*3 KR fib mole/ft
Vapor-mounted primary seal only
Liquid-mounted primary seal only
Vapor-mounted primary seal plus
secondary seal
Liquid-mounted primary seal plus
secondarv seal
6.7
3.0
secondary seal 2.5
Lquid-mounted primary seal plus
secondary seal 1.6
P* = the vapor pressure function (dimensionless)
= (P/PA)/((1 + (1 - (P/PA)0'5)2)
P = true vapor pressure of the material stored (psia)
P^ = partial pressure of the HAP (psia)
PA = atmospheric pressure (psia)
Mv = the average molecular weight of the stored
material vapor (Ib/lb mole)
Mv. = molecular weight of the HAP (Ib/lb-mole)
Kc = the product factor (dimensionless) = 1.0 for VOL
2205 = constant (Ib/Mg)
FF = the total deck fitting loss factor (Ib mole/yr)
n
- 2 (NF Kp ) = [(Np K ) -1- (NF Kp ) + . . + (Np Kp ) ]
4— i -L ^ 1 n n
where:
NF. = number of fittings of a particular type
1 (dimensionless). NF. is determined for the
specific tank or estimated from Tables 2-6
and 2-10.
2-15
-------
TABLE 2-4. EQUATIONS FOR ESTIMATING INTERNAL FLOATING ROOF
STORAGE TANK EMISSIONS (CONCLUDED)
KF = deck fitting loss factor for a particular
type fitting (lb mole/yr). KF. is determined
for each fitting type from Table 2-10.
n = number of different types of fittings
(dimensionless)
SD = the deck seam length factor (ft/ft2); see Table 2-7
KD = the deck seam loss factor (lb mole/ft yr)
= 0 for welded decks
= 0.34 for non-welded roofs
aReferences 2 and 3.
bSeal emission factors are not available for mechanical shoe
seals used in interval floating roof tanks. In the absence of
these factors, the factors for liquid mounted seals may be used
to estimate the emissions from an interval floating roof tank
equipped with a mechanical shoe seal.
2-16
-------
TABLE 2-5. EQUATIONS FOR ESTIMATING EXTERNAL FLOATING ROOF
STORAGE TANK EMISSIONS3
LT - Lw + LSE
A Mv P
Lw = 4.28 X 10~4 QCWL vi
D Mv P
= KSVNP*DMV.KC Pi
1 2205 P
LRF = FFP*MV KC Pi
1 2205 P
where,
LT = total loss (Mg/yr)
LW = withdrawal loss (Mg/yr)
LRF = roof fitting loss (Mg/yr)
LSE = seal loss from external floating roof tanks
(Mg/yr)
Q = product average throughput (bbl/yr); tank
capacity (bbl/turnover) x turnovers/yr
C = product withdrawal shell clingage factor (bbl/103
ft2); see Table 2-9
WL = density of product (Ib/gal); 7.4 to 8.0 Ib/gal
assumed as typical range for VOL liquids
D = tank diameter (ft)
Ks = seal factor: obtain from Table 2-8
V = average windspeed for the tank site (mph); 10 mph
can be assumed as the average windspeed, if site-
specific data are not available
N = seal windspeed exponent (dimensionless): obtain
from Table 2-8
2-17
-------
TABLE 2-5. EQUATIONS FOR ESTIMATING EXTERNAL FLOATING ROOF
STORAGE TANK EMISSIONS (CONCLUDED)
P* = the vapor pressure function (dimensionless)
= (P/PA)/(d + (1 - (P/PA)0'5)2)
P = true vapor pressure of the material stored (psia)
Pi = partial pressure of the HAP (psia)
PA = atmospheric pressure (psia)
Mv = the average molecular weight of the stored
material vapor (Ib/lb mole)
= molecular weight of the HAP (Ib/lb-mole)
Kc = product factor (dimensionless) =1.0 for VOL
FF = total roof fitting loss factor, Ib-mol/yr
n
where :
NF. = number of fittings of a particular type (see
1 Table 2-11
KF. = deck fitting loss factor for a particular
type fitting (lb mole/yr) . KF. is determined
for each fitting type from Table 2-11 using
the equation: Kp. = KF + KF Vm
1 *ai Fbi
n = number of different types of fittings
(dimensionless)
References 2, 3, and 5.
2-18
-------
external floating roof tank deck fittings. However, the newly
developed API procedures do include factors for deck fittings.
Number of columns. For a self-supporting fixed roof or
external floating roof, no columns are used. If the number of
columns is not known, Table 2-6 gives a typical number of columns
based on tank diameter.
Deck seam length. For internal floating roof tanks with
bolted decks, the deck seam length factor (SD) may be
approximated if the total length of deck seams is unknown. The
factors are presented in Table 2-7. If no specific information
is available, an SD of 0.20 ft/ft2 can be assumed.
Rim seal losses. For the rim seal loss, the seal factors
and seal related wind speed exponents are listed in Table 2-8.
Clingaae factors. For withdrawal loss, the shell clingage
factors are presented in Table 2-9. If no shell condition
information is available, the light rust condition may be
assumed.
Fitting loss factors. Once the number and type of deck
fittings are known for an internal floating roof tank, Table 2-10
can be used to obtain individual deck fitting loss factors. For
external floating roof tanks, fitting loss factors and the
typical number of roof fittings are provided in Tables 2-11,
2-12, and 2-13.
Mixtures. In cases where the HAP is part of a mixture, the
vapor pressure of the material stored must be: (1) measured; or
(2) calculated by summing the partial pressures of constituents.
As stated earlier, Raoult's Law and/or Henry's Law, as
applicable, are recommended for computing the partial pressure of
constituents in a mixture.
2.2.3 Documentation of HAP Emissions From Storage Tanks
All storage tank characteristics, tank throughput data, and
HAP physical property data used to perform storage tank emission
calculations should be provided for each tank. A set of forms
listing the required computation inputs is provided in
2-19
-------
TABLE 2-6. TYPICAL NUMBER OF COLUMNS AS A FUNCTION OF TANK
DIAMETER FOR INTERNAL FLOATING ROOF TANKS WITH COLUMN
SUPPORTED FIXED ROOFSa
Tank diameter range Typical number
D (ft) of columns, Nc
0 < D < 85 1
85 < D < 100 6
100 < D < 120 7
120 < D < 135 8
135 < D < 150 9
150 < D < 170 16
170 < D < 190 19
190 < D < 220 22
220 < D < 235 31
235 < D < 270 37
270 < D < 275 43
275 < D < 290 49
290 < D < 330 61
330 < D < 360 71
360 < D < 400 81
aReference 2. This table was derived from a survey of users and
manufacturers. The actual number of columns in a particular tank
may vary greatly with age, fixed roof style, loading
specifications, and manufacturing perogatives. Data in this
table should not supersede information on actual tanks.
2-20
-------
TABLE 2-7. DECK SEAM LENGTH FACTORS (SD) FOR TYPICAL
DECK CONSTRUCTIONS FOR INTERNAL FLOATING ROOF TANKS3
Typical deck seam
length factor,
Deck Construction SQ (ft/ft2)
Continuous sheet construction*3
5 ft wide 0.20°
6 ft wide 0.17
7 ft wide 0.14
Panel construction**
5 x 7.5 ft rectangular 0.33
5 x 12 ft rectangular 0.28
aReference 2. Deck seam loss applies to bolted decks only.
bSD = 1 , where W = sheet width (ft)
w
clf no specific information is available, these factors can be
assumed to represent the most common bolted decks currently in
use.
dsD = (L+w), where W = panel width (ft) and L = panel length (ft)
LW
2-21
-------
TABLE 2-8. SEAL RELATED FACTORS FOR EXTERNAL FLOATING ROOF
TANKS3*3
Welded Tank Riveted Tank
Tank and seal type Kg N Ks N
Metallic shoe seal
Primary seal only 1.2 1.5 1.3 1.E5
With shoe mounted secondary seal 0.8 1.2 1.4 1.2
With rim mounted secondary seal 0.2 1.0 0.2 1.6
Liquid mounted resilient seal
Primary seal only 1.1 i.o NAC NA
With weather shield 0.8 0.9 NA NA
With rim mounted secondary seal 0.7 0.4 NA NA
Vapor mounted resilient seal
Primary seal only
With weather shield
With rim mounted secondary seal
1.2
0.9
0.2
2.3
2.2
2.6
NA
NA
NA
NA
NA
NA
aBased on emissions from tank seal systems in reasonably good
working condition, no visible holes, tears, or unusually large gaps
between the seals and the tank wall. The applicability of KC;
decreases in cases where the actual gaps exceed the gaps assumed
during development of the correlation.
bReference 3.
CNA - Not Applicable.
2-22
-------
TABLE 2-9. AVERAGE CLINGAGE FACTORS (C) (bbl/1,000 f t2)a
Liquid
Gasoline
Single component
Light
0.
0.
rustD
0015
0015
Shell
condition
Dense rust
0
0
.0075
.0075
Gunite
0.
0.
lined
15
15
stocks
Crude oil 0.0060 0.030 0.60
aReference 2.
blf no specific information is available, these values can be
assumed to represent the most common condition of tanks currently
in use.
2-23
-------
TABLE 2-10. SUMMARY OF INTERNAL FLOATING DECK FITTING LOSS
FACTORS (Kp) AND TYPICAL NUMBER OF FITTINGS (Np)a
Deck fitting Typical number
loss factor, KF of fittings
Deck fitting type (Ib-mole/yr) NF
Access hatch 1
Bolted cover, gasketed 1.6
Unbolted cover, gasketed 11
Unbolted cover, ungasketed 25b
Automatic gauge float well 1
Bolted cover, gasketed 5.1
Unbolted cover, gasketed 15
Unbolted cover, ungasketed 28b
Column well (see Table 2-5)
Builtup column-sliding cover, gasketed 33
Builtup column-sliding cover, 47b
ungasketed
Pipe column-flexible fabric sleeve seal 10
Pipe column-sliding cover, gasketed 19
Pipe column-sliding cover, ungasketed 32
Ladder well 1
Sliding cover, gasketed 56
Sliding cover, ungasketed 76b
Roof leg or hanger well (5 + -P- + S2)C
Adjustable 7.9b 10 60°
Fixed 0
Sample pipe or well 1
Slotted pipe, sliding cover, gasketed 44
Slotted pipe, sliding cover, ungasketed 57
Sample well, slit fabric seal, I2b
10 percent open area
Stub drain, 1 inch diameterd 1.2 (_E>2)C
125
Vacuum breaker 1
Weighted mechanical actuation, 0.7b
gasketed
Weighted mechanical actuation, 0.9
ungasketed
aReference 2.~
blf no specific information is available, this value can be assumed
to represent the most common/typical deck fittings currently used.
2-24
-------
TABLE 2-10. SUMMARY OF INTERNAL FLOATING DECK FITTING LOSS
FACTORS (KF) AND TYPICAL NUMBER OF FITTINGS (Np)a (CONCLUDED)
CD = tank diameter (ft).
dNot used on welded contact internal floating decks.
2-25
-------
TABLE 2-11.
to
to
en
EXTERNAL ROOF FITTING LOSS FACTORS (Kfa, Kfb) AND
TYPICAL NUMBER OF ROOF FITTINGS (NF)a
Roof fitting type and construction details
1.
2.
3.
4.
5.
6.
7.
Access hatch (24- inch diameter well)
a. Bolted cover, gasket ed
b. Unbolted cover, ungasketed
c. Unbolted cover, gasketed
Guide pole well (8- inch diameter unslotted pole.
21 -inch diameter well)
a. Ungasketed sliding cover, without float
b. Gasketed sliding cover
Guide pole/sample well (8- inch diameter slotted pole.
21-inch diameter well)
a. Ungasketed sliding cover, without float
b. Ungasketed sliding cover, with float
c. Gasketed sliding cover, without float
d. Gasketed sliding cover, with float
Gauge float well (20- inch diameter well)
a. Unbolted cover, ungasketed
b. Unbolted cover, gasketed
c. Bolted cover, gasketed
Gauge hatch/sample well (8- inch diameter well)
a. Weighted mechanical actuation, gasketed
b. Weighted mechanical actuation, ungasketed
Vacuum breaker (10- inch diameter well)
a. Weighted mechanical actuation, gasketed
b. Weighted mechanical actuation, ungasketed
Roof drain (3- inch diameter)
a. Open
b. Closed, 90 percent
Kfa
Ib-mole
yr
0
2.7
2.9
0
0
0
0
0
0
2.3
2.4
0
0.95
0.91
1.2
1.1
0
0.51
Roof fitting loss factors
. . Kf b,
Ib-mole
f \
lml/h]n yr
0
7.1
0.41
67
3.0
310
29
260
8.5
5.9
0.34
0
0.14
2.4
0.17
3.0
7.0
0.81
m Typical Ho.
(dimensionless) of fittings, Nf
i
Ob
1.0
1.0
1
0.98b
1.4
c
1.2
2.0
1.2
2.4
1
1.0b
1.0
0
1
1.0b
1.0
, See Table 2-12
1.0b
1.0
See Table 2-12
1.4e
1.0e
(cuntirvjcd)
-------
TABLE 2-11. EXTERNAL ROOF FITTING LOSS FACTORS (Kfa, Kfb) AND
TYPICAL NUMBER OF ROOF FITTINGS (Np)a (CONCLUDED)
10
1
to
vj
Roof fitting type and construction details
8. Roof leg (3- inch diameter (eg)
a. Adjustable, pontoon area
b. Adjustable, center area
c. Adjustable, double-deck roofs
D. Fixed
Roof leg (2 1/2 inch diameter leg)
e. Adjustable, pontoon area
f. Adjustable, center area
g. Adjustable, double-deck roofs
h. Fixed
9. Rim vent (6- inch diameter)
a. Weighted mechanical actuation, gasketed
b. Weighted mechanical actuation, ungasketed
Kfa
Ib-mole
yr
1.5
0.25
0.25
0
1.7
0.41
0.41
0
0.71
0.68
Roof fitting loss factors
Kfb
Ib-mole
[ml/h]n yr
0.20
0.067
0.067
0
0
0
0
0
0.10
1.8
m Typical No.
(dimensionless) of fittings, Nf
See Table 2-13
1.0b
1.0b
1.0
0
0 See Table 2-13
0
0
0
1.0d
1.0b
1.0
The roof fitting loss factors (Kfa, K^, m) may be used only for wind speeds from 2 to 15 ml/h.
If no specific information is available, this value can be assumed to represent the most common or typical roof fittings currently in use.
cGuide pole/sample well is an optional fitting not typically used.
do:
Rim vents are used only with mechanical shoe primary seals.
eRoof drains that drain excess rainwater into the product are not used on pontoon floating roofs. They are, however, used on double-deck floating roofs
and are typically left "open."
-------
TANK 2-12. TYPICAL NUMBER OF VACUUM BREAKERS AND
ROOF DRAINS, NF
Tank
Diameter,
D(feet)a
50
100
150
200
250
300
350
400
Number of
Vacuum Breakers, NT?
Pontoon
Roof
1
1
2
3
4
5
6
7
Double-deck
Roof
1
1
2
2
3
3
4
4
Number of
Roof Drains, NF
(Double-deck
Roof)b
1
1
2
3
5
7
-
-
alf the actual diameter is between the diameters listed, the closet
diameter listed should be used. If the actual diameter is midway
between the diameters listed, the next larger diameter should be
used.
bRoof drains that drain excess rainwater into the product are not
used on pontoon floating roofs. They are, however, used on
double-deck floating roofs and are typically left open.
2-28
-------
TANK 2-13. TYPICAL NUMBER OF EXTERNAL FLOATING ROOF LEGSa
Tank
diameter, d(ft)b
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
370
380
390
400
Pontoon
Pontoon legs
4
4
6
9
13
15
16
17
18
19
20
21
23
26
27
28
29
30
31
32
33
34
35
36
36
37
38
38
39
39
40
41
42
44
45
46
47
48
Roof
Center legs
2
4
6
7
9
10
12
16
20
24
28
33
38
42
49
56
62
69
77
83
92
101
109
118
128
138
148
156
168
179
190
202
213
226
238
252
266
281
Double-deck
roof legs
6
7
8
10
13
16
20
25
29
34
40
46
52
58
66
74
82
90
98
107
115
127
138
149
162
173
186
200
213
226
240
255
270
285
300
315
330
345
aThis table was derived from a survey of users and manufacturers.
The actual number of roof legs may vary greatly depending on age,
floating roof style, loading specifications, and manufacturing
prerogatives. This table should not supersede information based
on actual tank data.
blf the actual diameter is between the diameters listed, the
closest diameter listed should be used. If the diameter is midway
between the diameters listed, the next larger diameter should be
used.
2-29
-------
Appendix A. The appropriate form in Appendix A should be
completed and submitted for each storage tank.
2.3 EQUIPMENT LEAKS
Leaks occur from plant equipment that have a point of
interface of the process fluid with the atmosphere. These points
of interface such as seals, packings, and gaskets have a tendency
to fail mechanically and thereby leak process fluid. The major
sources of equipment leaks include pumps, valves, flanges and
other connectors, compressors, sampling connection systems, open-
ended lines, agitators, and pressure relief valves. Detailed
discussions of these emission sources are presented in two EPA
reports.7'8 A brief discussion of these sources is presented
below.
Pumps. Pumps are used extensively in process units for the
movement of organic liquids. The centrifugal pump is the most
widely used pump. However, other types, such as the positive-
displacement, reciprocating and rotary action, and special canned
and diaphragm pumps, are also used. Chemicals transferred by
pumps can leak at the point of contact between the moving shaft
and stationary casing. Consequently, all pumps except the
shaftless type (canned-motor and diaphragm) require a seal at the
point where the shaft penetrates the housing in order to isolate
the pump's interior from the atmosphere.
Two generic types of seals, packed and mechanical, are
currently in use. Packed seals can be used on both reciprocating
and rotary action types of pumps. A packed seal consists of a
cavity ("stuffing box") in the pump casing filled with special
packing material that is compressed with a packing gland to form
a seal around the shaft, Deterioration of the packing results in
process liquid leaks.
Mechanical seals are limited in application to pumps with
rotating shafts and can be further categorized as single and
double mechanical seals. Depending on the condition and flatness
2-30
-------
of the seal faces, the leakage rate from a mechanical seal can be
quite low (as small as a drop per minute) and the flow is often
not visually detectable. In order to minimize emissions due to
seal leakage, an auxiliary sealing device such as packing can be
employed.
Valves. The types of valves commonly used in organic
chemical plants are globe, gate, plug, ball, relief, and check
valves. All except the relief valve (to be discussed further
below) and check valve are activated by a valve stem, which may
have either a rotational or linear motion, depending on the
specific design. This stem requires a seal to isolate the
process fluid inside the valve from the atmosphere. The
possibility of a leak through this seal makes it a potential
source of emissions. Since a check valve has no stem or
subsequent packing gland, it is not considered to be a potential
source of emissions.
Compressors. Gas compressors used in process units are
similar to pumps in that they can be driven by rotary or
reciprocating shafts. They are also similar to pumps in their
need for shaft seals to isolate the process gas from the
atmosphere. As with pumps, these seals are likely to be the
source of emissions from compressors.
Shaft seals for compressors may be chosen from several
different types: labyrinth, restrictive carbon rings, mechanical
contact, and liquid film. All of these seal types are leak
restriction devices; none of them completely eliminate leakage.
Many compressors may be equipped with ports in the seal area to
evacuate gases collecting there.
Safety Relief Devices. Engineering codes require that
pressure-relieving devices or systems be used in applications
where the process pressure may exceed the maximum allowable
working pressure of the vessel. The most common type of
pressure-relieving device used in process units is the pressure
relief valve. Typically, safety relief valves are spring-loaded
and designed to open when the process pressure exceeds a set
2-31
-------
pressure, allowing the release of vapors or liquids until the
system pressure is reduced to its normal operating level. When
the normal pressure is reattained, the valve reseats, and a seal
is again formed. The seal is a disk on a seat, and the
possibility of a leak through this seal makes the pressure relief
valve a potential source of emissions. Two potential causes of
leakage from safety relief valves are: "simmering or popping," a
condition due to the system pressure being close to the set
pressure of the valve, and improper reseating of the valve after
a relieving operation.
Open-Ended Lines. Some valves are installed in a system so
that they function with the downstream line open to the
atmosphere. Examples are purge valves, drain valves, and vent
valves. A faulty valve seat or incompletely closed valve would
result in leakage through the valve and emissions to the
atmosphere.
Sampling Connections. The operation of a process unit is
checked periodically by routing analyses of feedstocks and
products. To obtain representative samples for these analyses,
sampling lines must first be purged prior to sampling. The
purged liquid or vapor is sometimes drained onto the ground or
into a sewer drain, where it can evaporate and release emissions
to the atmosphere.
Flanges. Flanges are bolted, gasket-sealed junctions used
wherever pipe or other equipment such as vessels, pumps, valves,,
and heat exchangers may require isolation or removal. Normally,,
flanges are employed for pipe diameters of 50 mm or greater and
are classified by pressure and face type.
Flanges may become emission sources when leakage occurs due
to improperly chosen gaskets or a poorly assembled flange. The
primary cause of flange leakage is due to thermal stress that
piping or flanges in some services undergo; this results in the
deformation of the seal between the flange faces.
Agitators. Agitators are technologically similar to pumps
and, like pumps, can be controlled using seal technology.
2-32
-------
Although agitators have longer and larger diameter shafts than
pumps and produce greater tangential shaft loadings, the emission
factors used for calculating leaks from pumps are currently
acceptable for use in calculating leaks from agitators, due to
the lack of emissions data for agitators.
2.3.1 Acceptable Techniques For Establishing HAP
Emissions From Equipment Leaks
There are five methods for establishing emissions from
equipment leaks. These methods, in increasing order of
complexity and accuracy, are:
• Average emission factor method;
• Leak/no-leak emission factor method;
• Three-strata emission factor method;
• Application of EPA correlations; and
• Development of new correlations.
A detailed discussion of the above methods is presented in
the EPA report Protocols for Generating Unit-Specific Emission
Estimates for Equipment Leaks of VOC and VHAP.9 Alternatively,
these methods are presented in a Chemical Manufacturers
Association entitled Improving Air Quality: Guidance for
Estimating Fugitive Emissions from Equipment.10 All methods
start with obtaining an accurate identification and count of
equipment to be included. The equipment counts can simply be
used with the EPA's previously developed emission factors. The
next step in complexity and refinement is the use of a portable
organic analyzer to find the number of leaking and nonleaking
sources. Leaking and nonleaking emission factors developed by
the EPA can then be applied to generate the emissions. These
factors are presented in Table 2-14.
A final refinement is a method employing discrete emission
factors. In this approach emission factors are applied to
represent three different ranges of screening values. This has
2-33
-------
TABLE 2-14. LEAKING AND NON-LEAKING EMISSION FACTORS FOR
FUGITIVE EMISSIONS (kg/yr/source)a
Equipment
Service
Leaking
(>10,000 ppmv)
Emission Factor
Non Leaking
(<10,000 ppmv)
Emission Factor
Valves
Pump Seals
Gas/Vaporb
Light liquid
Heavy liquid
Light liquid
Heavy liquid
0.0451
0.0852
0. 00023°
0.437
0.3885
0.00048
0.00171
0.00023
0.0120
0.0135
Compressor Seals**
Pressure Relief
Valves
Gas/Vapor
Gas/Vapor
1.608
1.691
0.0894
0.0447
Flanges
Open-Ended Lines
All
All
0.0375
0.01195
0.00006
0.00150
aReference 8.
bThe leaking and non-leaking emission factors for valves in
gas/vapor service are based upon the emission factors determined
for gas valves in ethylene, cumene, and vinyl acetate units
during the SOCMI Maintenance Study.
cLeaking emission factor assumed equal to non-leaking emission
factor since the computed leaking emission factor
(0.00005 kg/hr/source) was less than the non-leaking emission
factor.
dEmission factor reflects existing control level of 60 percent
found in the industry; control is through the use of barrier
fluid/degassing reservoir/vent-to-flare or other seal leakage
capture system.
2-34
-------
been called the stratified emission factor approach, or the
three-strata approach. Applying the stratified emission factors
requires more rigorous measurement of organic vapor
concentrations with a portable instrument because actual
concentration readings must be recorded instead of noting whether
a piece of equipment is classified as leaking or not leaking.
Stratified emission factors developed by the EPA can then be
applied to generate the emission estimate. These factors are
presented in Table 2-15.
The remaining two methods make use of correlations relating
mass emissions to organic concentrations measured with a portable
organic analyzer. The EPA's previously developed correlations
are offered for use, and finally, if a process unit's emissions
are statistically different from those represented by the EPA's
correlations, provision is made for development of correlations
specifically for that process unit.
The EPA will not accept the average emission factor approach
for establishing base year emissions from equipment leaks, unless
the EPA average emission factors for equipment leaks are also
used to establish post-reduction emissions, and no reductions in
equipment leak emissions are claimed as part of the reduction
demonstration. The average emission factors are based on data
from process units with a wide range of equipment leak
frequencies. A given process unit may not have leak frequencies
similar to the average leak frequencies of these process units.
The application of these factors could, therefore, result in
erroneous emission estimates.
The other four emission estimate methods are considered
acceptable for the purpose of establishing emissions. The most
accurate estimates are obviously made through development of new
correlations. However, requiring the use of this method can be
costly and may discourage many facilities from pursuing the early
emission reduction program.
The leak/no-leak emission factor method, while a significant
improvement over the average emission factor method, may yield
2-35
-------
TABLE 2-15.
STRATIFIED EMISSION FACTORS FOR EQUIPMENT LEAKSa
(kg/hr/source)
Source
Service
Emission Factors (kg/yr/source)
for Screening Value Range, ppmv
0-1,000 1,001-10,000 >10,000
Compressor
Sealsd
Pump seals
Valves
Flanges,
connections
Pressure
Relief
devices
Open-ended
Lines
Gas/vapor
Light liquid
Heavy liquid
Gas/vapor*3
Light liquid
Heavy liquid
All
Gas/vapor
All
0.01132
0.00198
0.00380
0.00014
0.00028
0.00023C
0.00002
0.0114
0.00013
0.264
0.0335
0.0926
0.00165
0.00963
0.00023°
0.00875
0.279
0.00876
1.608
0.437
0.3885
0.0451
0.0852
0.00023
0.0375
1.691
0.01195
aReference 8.
"The leaking and non-leaking emission factors for valves in
gas/vapor service are based upon the emission factors determined
for gas valves in ethylene, cumene, and vinyl acetate units
during the SOCMI Maintenance Study.
GLeaking emission factor assumed equal to non-leaking emission
factor since the computed leaking emission factor
(0.00005 kg/hr/source) was less than the non-leaking emission
factor.
dEmission factor reflects existing control level of 60 percent
found in the industry; control is through the use of barrier
fluid/degassing reservoir/vent-to-flare or other seal leakage
capture system.
2-36
-------
estimates that are not completely accurate. However, these
estimates are considered to be within reasonable ranges of
accuracy. In addition, many facilities are expected to have
leak/no-leak frequency data already available which may encourage
them to implement an early emission reduction program.
Regardless of the method selected to establish base year
emissions, the same method must be used to establish post-
reduction emissions. The EPA will not allow participants to
demonstrate reductions by changing methodology.
2.3.2 Documentation of HAP Emissions From Equipment
Leaks
The documentation requirements discussed in this section
relate to the leak/no leak emission factor method. If a facility
chooses to use one of the more refined methods, the documentation
requirements will be considered on a case by case basis.
For the leak/no leak or stratified method, the following
information should be provided along with the computed emissions:
• Equipment count by equipment type (i.e., vapor valves,
liquid valves, etc.),
• Period during which screening was conducted,
• A description of any deviations from EPA Method 21
procedures,
• Percent of sources found leaking (by source type) or
measured concentration,
• HAP content as percent of VOC,
• Number of sources in facility that were considered
difficult to monitor and not screened.
Forms for reporting this information and computing baseline
emissions are provided in Appendix A for both the leak/no leak
approach and the stratified emission factor approach.
2-37
-------
2.4 TRANSFER OPERATIONS
Loading losses are the primary source of evaporative
emissions from rail tank car, tank truck and marine vessel
transfer operations. Loading losses occur as organic vapors in
"empty" cargo tanks are displaced to the atmosphere by the liquid
being loaded into the tanks. These vapors are a composite of (1)
vapors formed in the empty tank by evaporation of residual
product from previous loads, (2) vapors transferred to the tank
in vapor balance systems as product is being unloaded, and (3)
vapors generated in the tank as the new product is being loaded.
The quantity of evaporative losses from loading operations is,
therefore, a function of the following parameters.
• Physical and chemical characteristics of the previous
cargo,
• Method of unloading the previous cargo,
• Method of loading the new cargo, and
• Physical and chemical characteristics of the new cargo.
The three principal loading methods are splash loading,
submerged loading, and vapor balance loading. In the splash
loading method, the fill pipe dispensing the cargo is lowered
only partway into the cargo tank. Significant turbulence and
vapor/liquid contact occur during the splash loading operation,
resulting in high levels of vapor generation and loss. If the
turbulence is great enough, liquid droplets will be entrained in
the vented vapors.
A second method of loading is submerged loading. Two types
are the submerged fill pipe method and the bottom loading method.
In the submerged fill pipe method, the fill pipe extends almost
to the bottom of the cargo tank. In the bottom loading method, a.
permanent fill pipe is attached to the cargo tank bottom. The
fill pipe opening is below the liquid surface level, during most
of the loading operation. Liquid turbulence is controlled
2-38
-------
significantly, resulting in much lower vapor generation than
encountered during splash loading.
The recent loading history of a cargo carrier is just as
important a factor in loading losses as the method of loading.
If the carrier has carried a nonvolatile liquid such as fuel oil,
or has just been cleaned, it will contain vapor free air. If it
has just carried a volatile HAP and has not been vented, the air
in the carrier tank will contain volatile organic vapors, which
are expelled during the loading operation along with newly
generated vapors.
Cargo carriers are sometimes designated to transport only
one product, and in such cases are practicing "dedicated
service". Dedicated cargo tanks return to a loading terminal
containing air fully or partially saturated with vapor from the
previous load. Cargo tanks may also be "switch loaded" with
various products, so that a nonvolatile product being loaded may
expel the vapors remaining from a previous load of a volatile
product. These circumstances vary with the type of cargo tank
and with the ownership of the carrier, the petroleum liquids
being transported, geographic location, and season of the year.
One control measure for tank truck loading is called "vapor
balance service", in which the cargo tank retrieves the vapors
displaced during product unloading, and transports the vapors
back to the loading terminal. A cargo tank in vapor balance
service normally is saturated with organic vapors, and the
presence of these vapors at the start of submerged loading
results in greater loading losses than encountered during
nonvapor balance, or "normal", service. Vapor balance service is
usually not practiced with marine vessels, although some vessels
practice emission control by means of vapor transfer within their
own cargo tanks during balancing operations.
2-39
-------
2.4.1 Acceptable Techniques for Establishing Emissions from
Transfer Operations
Emissions of each HAP can be established using the following
expression for each type of loading operation:2
LL = 5.65E-06 SPMG
T
where: LL = loading loss, Mg/yr,
M = molecular weight of the HAP, Ib/lb-mole
P = true vapor pressure of the HAP loaded, psia
G = annual volume of liquid loaded, gallons,
T = temperature of bulk liquid loaded, °R (°F +
460) ,
S = saturation factor (see Table 2-16)
5.65E-06= constant to yield Mg/yr based on
12.46(1CT3 gal) (Mg/2205 Ib)
The saturation factor, S, represents the expelled vapor's
fractional approach to saturation, and it accounts for the
variations observed in emission rates from the different
unloading and loading methods. Table 2-16 lists the saturation
factors for various cargo vessels and modes of operation.
When a specific HAP is loaded into a cargo tank that was
previously used for a non-HAP, the clean cargo tank factor should
be used.
In cases where the HAP is part of a mixture rather than a
pure component, the partial pressure of the HAP should be used in
place of the pure component vapor pressure. For mixtures where
the HAP concentration is greater than 1 percent by volume,
Raoult's Law is deemed appropriate for computing the partial
pressure. For mixtures where the HAP concentration is less than
1 percent, Henry's Law is deemed appropriate for computing the
partial pressure.
Total HAP emissions from loading are computed by summing the
loading losses of individual HAP from each material loaded via
2-40
-------
TABLE 2-16. SATURATION (S) FACTORS FOR CALCULATING
ORGANIC LIQUID LOADING LOSSES3
Cargo Carrier
Mode of Operation
S Factor
Tank trucks and
rail tank cars
Marine vessels
Submerged loading
of a clean cargo
tank
Submerged loading:
dedicated normal
service
Submerged loading:
dedicated vapor
balance service
Splash loading of
a clean cargo tank
Splash loading:
dedicated normal
service
Splash loading:
dedicated vapor
balance service
Submerged loading:
ships
Submerged loading:
barges
0.50
0.60
1.00
1.45
1.45
1.00
0.2
0.5
aReference 2.
2-41
-------
each loading method. In cases where numerous materials are
loaded during the year by various loading techniques (i.e.,
submerged fill, splash fill, vapor balance), it is important that
the HAP emissions are calculated separately for each set of
conditions and then summed.
2.4.2 Documentation of HAP Emissions From Loading
Operations
Loading operation characteristics, volumes loaded into each
vessel type, and the HAP physical property data used to perform
loading operation emission calculations should be provided for
each material/vessel type. A set of forms listing the required
computation inputs is provided in Appendix A. The form provided
in Appendix A should be completed and submitted for each
combination of material loaded, cargo carrier, and mode of
operation.
2.5 WASTEWATER COLLECTION AND TREATMENT
In the manufacture of chemical products, wastewater streams
are generated which contain volatile organics. These wastewaters
are collected and treated in a variety of ways. Some of these
collection and treatment steps result in the emission of volatile
organics from the wastewater into the ambient air. This
subsection provides a discussion of the potential sources of
emissions during wastewater collection and treatment, and
techniques for establishing air emissions from wastewater
sources.
The industries covered by the Hazardous Organic NESHAP
differ in structure and manufacture a wide variety of products.
However, many of the chemical processes employed within these
industries use similar organic compounds as raw materials,
solvents, catalysts, and extractants. In addition, many of these
processes also generate similar organic by-products during
reaction steps. Consequently, many of the wastewater streams
2-42
-------
generated by the targeted industries are similar in their content
of organic compounds. These organic compound containing
wastewater streams result from both direct contact of water with
organic process streams and incidental contact of water with
organic compounds from leaking equipment. These wastewater
streams may be either continuous or intermittent.
Water comes in direct contact with organic compounds due to
many different chemical processing steps. As a result of this
contact, wastewater streams are generated which must be
discharged for treatment or disposal. A few sources of process
wastewater are:11
• Water used to wash impurities from organic products or
reactants;
• Water used to cool or quench organic vapor streams;
• Condensed steam from jet eductor systems pulling vacuum
on vessels containing organics;
• Water used as a carrier for catalysts and neutralizing
agents (e.g., caustic solutions); and
• Water formed as a by-product during reaction steps.
Two additional types of direct contact wastewater are
landfill leachate and water used in maintenance activities such
as equipment washes and spill cleanups. These two types of
wastewater are normally more variable in flow and concentration
than the streams previously discussed. In addition, landfill
leachate and spill cleanups may be collected for treatment
differently than the wastewater streams discharged from process
equipment such as scrubbers, decanters, evaporators, distillation
columns, reactors, and mixing vessels.
Wastewater streams which do not come in contact with organic
compounds in the process equipment are defined as "indirect-
contact" wastewater. However, a potential exists for organic
contamination of these wastewater types. Water streams which are
contaminated as a result of leaks from heat exchangers,
condensers and pumps (pump seal water) are examples of non-
2-43
-------
contact wastewater. These indirect contact wastewaters may or
may not be collected and treated in the same manner as direct
contact wastewaters. Pump seal water is normally collected in
area drains which tie into the process wastewater collection
system. This wastewater is then combined with direct contact
wastewater and transported to the wastewater treatment plant.
Wastewater contaminated from condenser and heat exchanger leaks
are often collected in different systems and bypass some of the
treatment steps used in the treatment plant.
Wastewater streams are collected and treated in a variety of:
ways. Generally, wastewater passes through a series of
collection and treatment units before being discharged from a
facility. Table 2-17 presents a list of components that may be
sources of emissions in facility collection and treatment
systems. Collection and treatment systems have openings, such as
at junction boxes and manholes, that allow organics to escape to
the atmosphere. The magnitude of emissions depends on factors
such as the physical properties of the pollutants and the
collection and treatment system.
2.5.1 Acceptable Techniques for Establishing HAP
Emissions From Wastewater Collection and Treatment
The accepted approach for establishing emissions from
wastewater sources is direct measurement of the volatile organic
HAP content and measurement or estimation of the wastewater flow.
However, considering the expense of direct measurement and the
accessibility of some wastewater streams, it may not be feasible
to measure the flowrate and HAP composition of all wastewater
streams. A more detailed description of the accepted approach is
provided below. It should be noted that the procedure described
below is based on a single-phased wastewater stream passing
through a typical wastewater collection and treatment system.
The facility may need to make adjustments if there is a separate
organic phase. Also, facilities must adjust their wastewater
emissions if they currently have treatment in place prior to the
2-44
-------
TABLE 2-17. EMISSION SOURCES IN WASTEWATER COLLECTION
AND TREATMENT SYSTEMS3
Wastewater Collection System;
Drains
Junction Boxes
Lift Stations
Manholes
Trenches
Sumps
Surface Impoundments
Wastewater Treatment Units;
Weirs
Oil/Water Separators
Equalization Basins or Neutralization Basins
Clarifiers
Aeration Basins
pH Adjustment Tanks
Flocculation Tanks
aReference 11.
2-45
-------
wastewater treatment plant such as phase separation (e.g.,
decanters, API separators) or steam or air strippers.
Identification of wastewater sources. The first step
towards establishing emissions from wastewater sources is the
identification of all wastewater streams within the process or
facility. As described above, there are two general types of
organic containing wastewaters: direct contact and indirect
contact. In general, direct contact wastewaters account for the
majority of HAP loadings in facility wastewaters.
In characterizing wastewater streams, it is important to
identify the wastewater stream at the point of generation. The
anticipated definition for point of generation under the
Hazardous Organic NESHAP is as follows. Point of waste
generation means the location where the waste stream exits the
process unit component or product or feed storage tank prior to
handling or treatment in an operation that is not an integral
part of the production process, or in the case of waste
management units that generate new waste after treatment, the
location where the waste stream exits the waste management unit
component. A piece of equipment is an integral part of the unit
if it is essential to the operation of the process unit; i.e.,
removal of the equipment would result in the process unit being
shut down. For example, a stripping column is part of the
process unit if it produces the principle product stream and a
wastewater which is discharged to the sewer. However, an
identical stripper which treats a wastewater stream and recovers
residual product would not be considered an integral part of the
process unit. The point of generation for measurement or
sampling is defined as the point where the wastewater stream
exits the process unit before it is treated or mixed with other
wastewater streams, and prior to exposure to the atmosphere. The
point of generation for landfill leachate shall be at the pump
well from which the leachate is pumped out of the landfill.
Measurement of stream flow and concentration. After
identifying all facility or process wastewater streams, both
2-46
-------
continuous and intermittent, the next step is to either directly
measure the annual average flowrate or estimate the annual
average flowrate based on engineering calculations such as heat
and material balances. This must be done for each wastewater
stream, at the point of generation. It is important that the
sample be taken at a time representative of normal flow.
Additionally, attempts should be made to collect a sample
representative of annual average concentrations. In the case of
highly variable flow and concentration, a sufficient number of
samples need to be taken to characterize the wastewater stream
with respect to a flow-weighted annual average.
Two methods can be used to determine wastewater flowrate.
These are: 1) based on historical records; or 2) using
measurements that are representative of average wastewater
generation rates.
It is preferable to measure the HAP concentration of each
wastewater stream using draft EPA Methods 25D with Method 18 or a
procedure validated by EPA Method 301. Proposed Method 25D is a
method developed specifically for quantifying the organic
emission potential of a wastewater stream. Proposed Method 25D
is a purge and trap method that was developed for quantification
of volatile organic emission potential and employs a flame
ionization detector (FID) and a halogen detector. Because
proposed Method 25D yields only a single volatile organic number,
Method 18 is needed on the Method 25D purge stream to quantify
specific HAP concentrations. The FID/halogen detector prescribed
by Method 25D is replaced with a gas chromatograph and the
procedures prescribed in Method 18. It is important that the
sampling and purge procedures prescribed in proposed Method 25D
are followed.
Alternatively, calculations based on engineering
principles or material balance data are acceptable in situations
where:
(1) No applicable EPA Reference Method, EPA Conditional
Method, or other source test method exists;
2-47
-------
(2) It is not technically or economically feasible to
perform source tests;
(3) It can be demonstrated to the satisfaction of the
reviewing agency that the calculation will provide
emission estimates of accuracy comparable to any
applicable source test method;
(4) The base year conditions no longer exist and cannot be
reproduced and testing under the current conditions and
extrapolating will not produce results more accurate
than an estimate base on engineering principles or
material balance; or
(5) The emissions from one or a set of emission points in
the source are small compared to total source emissions
and errors in estimating emissions from such points
will not have a significant effect on the accuracy of
estimated total emissions from the source.
The burden of adequately demonstrating one of these reasons for
not source testing is placed on the source owner or operator.
If a sampling and analytical procedure other than proposed
Method 25D with Method 18 is used, it should be validated with
Method 301. Such measured concentrations can be adjusted using
the fraction measured (fm) factors provided in Table 2-18 to
approximate the volatile organic (VO) concentration that would be
measured by Method 25D with Method 18.
Compute emissions. After both the annual average flow and
concentration have been determined for each wastewater stream,
the HAP emissions can be computed as:
= 5.26E-04 Q
where,
WEg. = HAP emissions, Mg/yr,
Q = annual average flow rate, 1pm,
CVOHAP- * annual average HAP-specific concentration,
1 mg/1,
fei = fraction of the HAP that would be emitted
from the wastewater (see Table 2-18) ,
2-48
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF
and
CAS NO
75070
60355
75058
98862
53963
107028
79061
79107
107131
107051
92671
62533
92159
71432
92875
98077
100447
92524
117817
542881
75252
106990
105602
75150
56235
463581
120809
79118
532274
108907
67663
107302
126998
108394
1319773
HENRYS LAW
COMPOUND NAME (atm-iiT3/1?11101)
Acetaldehyde
Acetamide
Acetonitrile
Acetophenone
Acetylaminofluorine-2
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
Aminobiphenyl-4
Aniline
Anisidine-o
Benzene (including
benzene from gasoline)
Benzidene
Benzotrichloride
Benzyl chloride
Biphenyl
Bis(2-ethylhexyl)
phthalate
Bis (chloromethyl) ether
Bromoform
Butadiene-1, 3
Caprolactam
Carbon disulfide
Carbon tetrachloride
Carbonyl sulfide
Catechol
Chloroacetic acid
Chloroacetophenone-2
Chlorobenzene
Chloroform
Chloromethyl
methyl ether
Chloroprene (2-Chloro-
1, 3 -Butadiene)
Cresols/Cresylic acid
(isomers & mix) ,mix
Cresols/Cresylic acid
(isomers & mix) , m-
9.50E-05
1.33E-06
5.80E-06
1.41E-05
1.34E-06
5.66E-05
5.20E-10
1.20E-05
8.80E-05
3.71E-01
7.30E-03
2.60E-06
8.20E-04
5.50E-03
l.OOE-04
2.19E-03
4.33E-04
1.01E-01
3.00E-07
2.10E-04
5.84E-04
1.42E-01
4.55E-07
1.68E-02
3.00E-02
5.76E-05
2.33E-05
1.11E-09
2.40E-04
3.93E-03
3.39E-03
8.65E-05
3.35E-01
2.13E-05
4.43E-07
FM
0.72
0.42
0.74
0.81
0.43
0.85
0.003
0.45
0.88
1.00
0.10
0.25
0.03
1.00
0.00
1.00
1.00
1.00
0.97
0.89
0.48
1.00
0.01
1.00
1.00
0.55
0.00
0.03
0.84
1.00
1.00
0.84
1.00
0.11
0.08
FE
0.45
0.18
0.27
0.33
0.18
0.42
0.00
0.32
0.45
1.00
0.74
0.22
0.60
0.72
0.46
0.66
0.55
0.91
0.08
0.51
0.57
0.93
0.11
0.79
0.83
0.42
0.36
0.00
0.52
0.70
0.69
0.45
0.99
0.36
0.10
(continued)
2-49
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF
and fm± (Continued)
CAS NO
HENRYS LAW
COMPOUND NAME
FM
FE
95487
106445
98828
94757
3547044
334883
132649
96128
84742
106467
91941
111444
542756
111422
121697
64675
119904
60117
119937
79447
68122
57147
131113
77781
534521
51285
121142
Cresols/Cresylic acid
(isomers & mix),o-
Cresol/Cresylic acid
(isomers & mix) , p-
Cumene ( i s opr opy 1
benzene)
D-2 , 4 Salts and esters
DDE ( Dichlorodipheny 1-
dichloroethylene)
Diazomethane
Dibenzofuran
Dibromo-1,2-
chloropropane-3
Dibutylphthalate
Dichlorobenzene (p)
-1,4 (PDB)
Dichlorobenzidene-3 , 3 '
Dichloroethyl ether
(bis(2-chloroethyl)
ether)
Dichloropropene-1, 3
Diethanolamine
Diethylaniline-N,N
Diethyl sulfate
Dimethoxybenzidine-3 , 3 '
Dimethyl
aminoazobenzene
Dimethyl benzidine-
3,3-
Dimethyl carbamoyl
chloride
Dimethyl formamide
(DMF)
Dimethyl hydrazine-1, 1
Dimethyl phthalate
Dimethyl sulfate
Dinitro-o-cresol-4 , 6 ,
and salts
Dinitrophenol-2 , 4
Dinitrotoluene-2 , 4
(DNT)
2.60E-06
4.43E-07
1.46E-02
6.21E-02
1.14E-01
3.40E-09
9.70E-05
2.36E-05
2.80E-07
1.60E-03
l.OOE-04
1.30E-05
2.33E-03
7.31E-03
8.86E-05
1.36E-07
2.44E-03
1.13E-04
4.40E-04
8.33E-03
3.47E-09
1.24E-04
2.15E-06
5.86E-07
1.40E-05
1.53E-07
1.25E-10
0.12
0.06
1.00
0.75
1.00
0.55
1.00
1.00
0.32
1.00
0.54
0.94
1.00
0.00
1.00
0.01
0.01
0.32
0.11
0.25
0.01
0.49
0.10
0.08
0.04
0.01
0.004
0.22
0.10
0.78
0.88
0.92
0.00
0.46
0.36
0.07
0.64
0.46
0.32
0.66
0.74
0.45
0.03
0.67
0.47
0.56
0.75
0.00
0.47
0.21
0.12
0.33
0.03
0.00
(continued)
2-50
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF fe^ and rm^(Continued)
CAS NO
123911
122667
106898
106887
140885
100414
51796
75003
106934
107062
107211
75218
96457
75343
50000
112367
111966
112345
111900
112152
111773
110714
111762
112072
HENRYS LAW
COMPOUND NAME ( atm-nT 3 / 9™° 1 )
Dioxane-1,4 (1,4-
Diethyleneoxide)
Diphenylhydrazine-1 , 2
Epichlorohydr in ( 1-
Chloro-2 , 3-epoxypropane)
Epoxybutane-1 , 2
Ethyl aery late
Ethyl benzene
Ethyl carbamate
Ethyl chloride
( Chlor oethane )
Ethylene dibromide
(Dibromoethane) (EDB)
Ethylene dichloride
( 1 , 2-Dichloroethane)
Ethylene glycol
Ethylene oxide
Ethylene thiourea
Ethylidene dichloride
( 1 , 2-Dichloroethane)
Formaldehyde
Diethylene glycol
diethyl ether
Diethylene glycol
dimethyl ether
Diethylene glycol
monobutyl ether
Diethylene glycol
monoethyl ether
Diethylene glycol
monoethyl ether
acetate
Diethylene glycol
monomethyl ether
Ethylene glycol
dimethyl ether
Ethylene glycol
monobutyl ether
Ethylene glycol
monobutyl ether
acetate
2.31E-05
3.50E-03
3.23E-05
2.50E-01
3.50E-04
6.44E-03
5.86E-05
9.10E-03
6.90E-04
1.20E-03
1.03E-07
1.42E-04
1.60E-04
5.54E-08
5.76E-05
2.13E-05
2.48E-06
3.30E-08
3.38E-08
1.91E-07
2.27E-08
1.55E-05
7.94E-07
1.64E-08
FM
0.68
1.00
0.86
0.88
0.79
1.00
0.01
1.00
1.00
1.00
0.004
0.71
0.001
1.00
0.53
0.77
0.37
0.03
0.03
0.12
0.02
0.68
0.29
0.10
FE
0.36
0.69
0.38
0.97
0.54
0.73
0.42
0.75
0.58
0.62
0.01
0.48
0.49
0.00
0.42
0.36
0.22
0.00
0.00
0.05
0.00
0.34
0.14
0.00
(Continued)
2-51
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF
and fir^ (Continued)
HENRYS LAW
CAS NO
COMPOUND NAME
FM
FE
110805
111159
Ethylene glycol
monoethyl ether
Ethylene glycol
monoethyl ether
acetate
1.11E-06
1.49E-06
0.38
0.36
0.16
0.18
109864 Ethylene glycol 6.90E-07
monoethyl ether
110496 Ethylene glycol 1.95E-06
monomethyl ether
acetate
122996 Ethylene glycol 4.93E-08
monophenyl ether
2807309 Ethylene glycol 2.74E-06
monopropyl ether
112492 Triethylene glycol 4.31E-07
118741 Hexachlorobenzene 6.80E-04
87683 Hexachlorobutadiene 2.56E-02
67721 Hexachloroethane 2.49E-06
822060 Hexamethylene-1,6- l.OOE-06
diisocyanate
680319 Hexamethylphosphoramide 5.00E-05
110543 Hexane 1.22E-01
302012 Hydrazine 6.66E-07
123319 Hydroquinone 1.57E-07
78591 Isophorone 5.76E-06
108316 Maleic anhydride 4.00E-08
67561 Methanol 2.70E-06
74839 Methyl bromide 2.21E-01
(Bromomethane)
74873 Methyl chloride 8.14E-03
(Chloromethane)
71556 Methyl chloroform 3.00E-03
(1,1,1-Trichloroethane)
78933 Methyl ethyl ketone 4.35E-05
(2-Butanone)
60344 Methyl hydrazine 3.44E-06
74884 Methyl iodide 2.53E-03
(lodomethane)
108101 Methyl isobutyl 4.95E-05
ketone (Hexone)
0.18
0.37
0.03
0.52
0.16
1.00
1.00
1.00
0.09
0.00
1.00
0.57
0.00
1.00
0.05
0.32
0.54
1.00
1.00
0.88
0.05
0.35
0.95
0.13
0.20
0.00
0.22
0.00
0.58
0.82
0.22
0.16
0.41
0.92
0.13
0.04
0.27
0.00
0.22
0.96
0.75
0.68
0.40
0.24
0.67
0.41
(Continued.)
2-52
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF fej_ and fm^ (Continued)
CAS NO
624839
80626
1634044
101144
75092
101688
101779
91203
98953
92933
100027
79469
684935
62759
59892
108952
106503
75445
85449
1336363
1120714
57578
123386
114261
78875
75569
75558
106514
100425
96093
1746016
HENRYS LAW
COMPOUND NAME (atm-nT3/^01)
Methyl isocyanate
Methyl methacrylate
Methyl tert butyl
ether (MTBE)
4,4 Methylene bis (2-
chloroaniline)
Methylene chloride
(Dichloromethane)
Methylene diphenyl
diisocyanate (MDI)
Methylene dianiline
-4,4 (MDA)
Naphthalene
Nitrobenzene
Nitrobiphenyl-4
Nitrophenol-4
Nitropropane-4
N-Nitroso-N-
methylurea
N-Nitrosodi-
methylamine
N-Nitrosomorpholine
Phenol
Phenylenediamine-p
Phosgene
Phthalic anhydride
Polychlorinated
biphenyls (Aroclors)
Propane sultone- 1 , 3
Propiolactone (b-)
Prop iona Idehy de
Propoxur (Baygon)
Propylene dichloride
Propylene oxide
1,2-Propylenimine (2-
methyl aziridine)
Quinone
Styrene
Styrene oxide
Tetrachlorodibenzo-p-
dioxin-2,3,7,8
2.28E-05
6.60E-05
5.01E-03
4.83E-03
3.19E-03
5.34E-03
2.60E-06
1.18E-03
1.31E-05
7.30E-03
7.09E-07
1.21E-03
5.15E-05
5.09E-04
5.73E-05
4.54E-07
1.13E-08
1.71E-01
9.00E-07
2.94E-04
1.50E-05
9.22E-07
1.15E-03
5.00E-06
2.30E-03
1.34E-03
9.39E-06
7.20E-03
3.30E-03
1.07E-04
2.10E-03
FM
0.27
0.80
0.91
0.15
1.00
0.47
0.01
1.00
0.58
0.45
0.001
0.54
0.38
0.12
0.06
0.06
0.001
0.87
0.10
1.00
0.01
0.24
0.81
0.10
1.00
0.84
0.81
0.87
1.00
1.00
1.00
FE
0.36
0.43
0.71
0.71
0.68
0.72
0.22
0.62
0.33
0.74
0.13
0.62
0.42
0.56
0.42
0.10
0.00
0.95
0.15
0.53
0.33
0.15
0.62
0.26
0.66
0.63
0.30
0.74
0.69
0.46
0.66
(Continued)
2-53
-------
TABLE 2-18. COMPOUND-SPECIFIC VALUES OF
and fm^ (Concluded)
CAS NO
HENRYS LAW
COMPOUND NAME
FM
FE
79345
127184
108883
95807
584849
95534
120821
79005
79016
95954
88062
121448
1582098
540841
108054
593602
75014
75354
1330207
108383
95476
106423
Tetrachloroethane-
1,1,2,2
Perchloroethylene
(Tetrachloroethylene)
Toluene
Toluene 2 , 4 diamine
Toluene 2 , 4
diisocyanate
Toluidine (o-)
Trichlorobenzene
(1,2,4-)
Trichloroethane
(1,1,2-) (Vinyl
Trichloride)
Trichloroethylene
Trichlorophenol-2 ,4,5
Trichlorophenol-2 ,4,6
Triethylamine
Trif luralin
Trimethylpentane
(2,2,4-)
Vinyl acetate
Vinyl bromide
Vinyl chloride
(Chloro Ethylene)
Vinylidene chloride
( 1 , 1-Dichloroethylene)
Xylenes (isomers and
mixture) mix
Xylenes (isomers and
mixture) -m
Xylenes (isomers and
mixture) -o
Xylenes (isomers and
mixture) -p
3.80E-04
2.87E-02
6.68E-03
6.03E-08
8.30E-06
1.91E-05
1.42E-03
7.40E-04
9.10E-03
1.77E-05
1.70E-05
2.66E-03
4.17E-06
2.41E-03
6.20E-04
2.40E-04
8.60E-02
1.50E-02
5.20E-03
5.27E-03
5.27E-03
5.27E-03
1.00
1.00
1.00
0.001
0.002
0.27
1.00
0.97
1.00-
0.29
0.40
0.93
0.74
1.00
0.75
0.84
1.00
1.00
1.00
1.00
1.00
1.00
0.55
0.83
0.73
0.00
0.30
0.35
0.63
0.59
0.75
0.34
0.34
0.67
0.25
0.67
0.58
0.52
0.90
0.79
0.72
0.72
0.72
0.72
"Chemical family with broad range of values, not determined.
2-54
-------
= fraction of the HAP that would be measured by
proposed Method 25D/18 (see Table 2-18), and
5.26E-04 = a constant to convert to the unit Mg/yr based
on (60 min/hr)(8760hr/yr)(Mg/109 mg).
In cases where fe-j_ is greater than fm.j_, a method other than
Method 25D/18 should be used to quantify the HAP. Certain
compounds cannot be quantified using proposed Method 25D with
Method 18.
In cases where all of the volatile organic is a single HAP
and Method 25D is performed alone, the fe-j_ and fm^_ for the known
HAP should be used (see Table 2-18) .
If the HAP concentration is measured using Method 301, a
value of 1 is to be used for fm^
The total HAP emissions from wastewater sources is computed
by simply summing the emissions of individual HAP for each
streams.
2.5.2 Documentation of HAP Emissions From Wastewater
Sources
In establishing HAP emissions from wastewater sources, the
following information should be provided with the computed
emission rate for each stream:
• Stream identification,
• Stream flow rate, method of measurement, and date of
measurement,
• Stream discharge temperature,
• Stream HAP concentration, method of measurement, and
date of measurement, and
• A statement that the measured flow and concentration
are believed to be representative of normal operation.
The form provided in Appendix A should be completed and submitted
for each wastewater stream.
2-55
-------
REFERENCES
1. U.S. Environmental Protection Agency, Office of Research and
Development. Protocol for the Field Validation of Emission
Concentrations from Stationary Sources. EPA Publication No.
450/4-90-015. Research Triangle Park, North Carolina.
April 1990.
2. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Compilation of Air Pollutant
Emission Factors, Volume I: Stationary Point and Area
Sources. EPA-AP-42. Research Triangle Park, North
Carolina. September 1985. pp. 4.4-1 through 4.4-17.
3. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. VOC Emissions from Volatile Organic
Liquid Storage Tanks--Background Information for Proposed
Standards. EPA-450/3-81-003a.
4. American Petroleum Institute. Manual of Petroleum
Measurement Standards Chapter 19 - Evaporative Loss
Measurement. API Publication 2518. October 1991.
5. American Petroleum Institute. Evaporative Loss From
External Floating-Roof Tanks. API Publication 2517.
Washington, D.C. February 1989.
6. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Guideline Series: Control of
Volatile Organic Liquid Storage in Floating and Fixed Roof
Tanks. EPA 450/3-84-005. Research Triangle Park, NC.
July 1984.
7. U.S. Environmental Protection Agency. VOC Fugitive
Emissions in Synthetic Organic Chemical Manufacturing
Industry - Background Information for Proposed Standards.
Publication No. 450/3-80-033a. Research Triangle Park, NC.
November 1980.
8. U.S. Environmental Protection Agency. Control of Volatile
Organic Compound Leaks from Synthetic Organic Chemical and
Polymer Manufacturing Equipment - Guideline Series.
Publication No. 450/3-83-006. Research Triangle Park, NC.
March 1984.
9. U.S. Environmental Protection Agency. Protocols for
Generating Unit-Specific Emission Estimates for Equipment
Leaks of VOC and VHAP. Publication No. 450/3-88-010.
Research Triangle Park, NC. October 1988.
2-56
-------
10. Chemical Manufacturers Association. Improving Air Quality:
Guidance for Estimating Fugitive Emissions from Equipment.
Washington, DC. January 1989.
11. U.S. Environmental Protection Agency. Industrial Wastewater
Volatile Organic Compound Emissions - Background Information
for BACT/LAER Determinations. Publication No.
EPA-450/3-90-04. Research Triangle Park, N.C. January
1990. pp 3-2 through 3-6.
2-57
-------
3.0 ESTABLISHING EMISSIONS FROM CHROMIUM ELECTROPLATING AND
ANODIZING OPERATIONS
Chromium electroplating is the process by which chromium is
electrochemically deposited from a solution of chromic acid onto
a metal or plastic part. Conventional plating solutions contain
32 ounces of chromic acid per gallon of water and a small amount
of sulfuric acid or fluoride compounds as a catalyst. In the
chromium plating process, the part to be plated is connected as
the cathode in the electrical circuit and lead alloys are used as
the anode. There are two types of chromium plating processes:
hard chromium plating and decorative chromium plating.
In hard chromium plating, a relatively thick layer of
chromium (0.05 to 30 mils) is deposited directly on a base metal
(usually steel) to provide a surface with wear resistance, a low
coefficient of friction, hardness, and corrosion resistance.
Hard chromium plating is typically performed in stand-alone
plating tanks. Typical plating times range from one to several
hours. Hard plating, also called functional plating, is used for
items such as hydraulic cylinders and rods, industrial rolls,
zinc die castings, and marine hardware.
Decorative chromium plating is performed as the last step in
a series of plating and metal finishing operations. The base
material is generally plated with a layer of copper, followed by
a layer of nickel and then followed by a relatively thin layer
(less than 0.1 mil) of chromium. The chromium provides an
aesthetically pleasing, bright, tarnish resistant surface.
Plating times are only a few minutes. Decorative chromium
plating is used for items such as automotive trim, metal
furniture, bicycles, hand tools, and plumbing fixtures.
Emissions result from the formation of mist produced by the
electrodeposition reactions. The chromium plating process is
highly inefficient. Only about 10 to 20 percent of the current
applied is actually consumed by the deposition of chromium on the
3-1
-------
item plated. Eighty to ninety percent of the current applied is
consumed in side reactions that form hydrogen gas at the cathode
and oxygen gas at the anode. The formation of these gases
produces small bubbles which burst at the surface of the plating
solution, which generates substantial amounts of fine mist
comprised of plating solution. As more current is applied, more
gassing and misting is produced.
To eliminate exposures to chromic acid mist in the
workplace, plating tanks are usually equipped with local
ventilation systems which effectively capture the mist at the
plating tank. The ventilation air is usually treated in an air
pollution control device prior to being discharged to the
atmosphere. Because mists are comprised of aerosols, they are
considered a particulate pollutant rather than a gas or vapor.
Consequently, a 95 percent reduction would need to be achieved to
qualify for an early reduction compliance extension.
Chromic acid anodizing is a process by which a film of
aluminum oxide is formed on the surface of aluminum
electrolytically to enhance corrosion resistance. Chromic acid
anodizing is used primarily for aircraft parts that are subject
to high stress and corrosive conditions. Conventional anodizing
solutions contain 7 to 8 ounces of chromic acid per gallon of
water. In chromic acid anodizing, the part is connected as the
anode in the electrical circuit instead of the cathode as in
chromium plating. Unlike the chromium plating process, the
anodizing process is a voltage controlled process rather than a
current controlled process. Voltage is applied to the tank in a
step-wise fashion until a level of 20 or 40 volts is reached and
is then maintained for the remainder of the anodizing time (about
1 hour). As in chromium plating, chromic acid emissions are
formed in the anodizing tank as a result of the evolution of
hydrogen and oxygen gases. The amount of gassing or misting
decreases over the anodizing period as the current decreases. In
general, emissions from anodizing tanks are similar in magnitude
to those measured at decorative chromium plating facilities.
3-2
-------
3.1 CONTROL TECHNIQUES/PERFORMANCE
The principal techniques used to control emissions of
chromic acid mist from chromium plating and chromic acid
anodizing operations include add-on air pollution control
devices, particularly mist eliminators and wet scrubbers, and
chemical fume suppressants.
Mist eliminators include both chevron-blade and mesh-pad
designs. Chevron-blade mist eliminators consist of one or more
sets of parallel baffles that cause the gas flow to change
direction several times, causing the mist droplets to impinge the
blades. Mesh-pad mist eliminators consist of layers of
interlocking filaments densely packed between two supporting
grids. Both designs are operated dry with scheduled washdowns
with water to remove accumulated chromic acid.
The packed bed scrubber is the predominant scrubber design
used to control emissions of chromic acid mist from plating and
anodizing operations. Designs typically include a countercurrent
water spray section, a packed-bed section, and a mist elimination
section. The packed-bed is usually about 12 inches thick and
contains packing media made of polypropylene rings or saddles
that are continuously or intermittently washed with water. Mist
eliminator sections generally consist of standard chevron-blade
designs.
Chemical fume suppressants are surface-active compounds that
are added directly to plating and anodizing baths to inhibit
misting. Fume suppressants are classified as wetting agents,
foam blankets, and combinations of foam blankets and wetting
agents. Wetting agents reduce misting by lowering the surface
tension of the plating or anodizing solution, which substantially
mitigates mist formation. Foam blankets reduce misting by
entrapping the chromic acid mist as it forms at the surface of
the plating bath under a blanket of foam. Combination wetting
agents/foam blankets reduce misting by both methods. Fume
suppressants are in wide use at decorative chromium
3-3
-------
electroplaters and chromic acid anodizers. In contrast, fume
suppressants are seldom used at hard chromium platers. Wetting
agents aggravate pitting, which affects the quality of the hard
chromium plate. Foam blankets in hard chromium plating tanks
increase the potential for explosion due to buildups of hydrogen
gas under the foam layer.
In terms of performance, all three control devices can be
characterized as constant outlet devices; that is, outlet
loadings are relatively constant over a wide range of inlet
loadings. As a result, percent reductions achieved will vary
depending on the inlet conditions encountered. Consequently,
percent reduction is an uncertain indicator of performance unless
comparisons are made at similar inlet conditions.
Chevron-blade mist eliminators are demonstrated to achieve
outlet concentrations of 0.15 mg/dscm. This would be equivalent
to about 95 percent reduction or higher at inlet concentrations
typically encountered at hard chromium electroplating plants (4
mg/dscm).
Outlet concentrations of less than 0.05 mg/dscm are
achievable with mesh-pad mist eliminators and packed-bed
scrubbers. This would be equivalent to about a 99 percent
reduction at a typical hard chromium electroplating plant.
Fume suppressants can achieve outlet concentrations of less
than 0.005 mg/dscm at decorative chromium and anodizing
facilities. This would be equivalent to about a 99.5 percent
reduction using a typical inlet concentration at decorative
chromium and anodizing plants (about 1 mg/dscm).
3.2 ACCEPTABLE TECHNIQUES FOR ESTABLISHING EMISSIONS
There are two fundamental approaches available for
establishing annual emissions for base year and post-reduction
conditions. The first and preferred approach in most instances
is the use of emissions data obtained by the direct measurement
of emissions using validated test methods. The second approach,
3-4
-------
where emission measurement is not possible or the cost of
measurement is prohibitive relative to the cost of emission
control, is the use of emission factors, if available.
3.2.1 Direct Measurement
When direct measurements are made, sample locations, number
of traverse points, and gas stream characteristics should be
determined using EPA Methods 1, 2, and 4; and the hexavalent
chromium concentration should be determined using EPA Method 5
modified for chromium measurement. Modifications include
eliminating the filter and using 0.1N sodium bicarbonate in the
impingers rather than water. The collected samples are then
recovered and analyzed by atomic absorption to determine chromium
content. A draft copy of the method for determining the
concentration of chromium can be obtained by contacting the
Emission Measurement Branch at (919) 541-5236.
Annual chromium emissions, base year or post-reduction, can
then be calculated using the following equation:
ER = (C) (Q) (60) (t)/1.0 x 109,
where,
ER = annual chromium emissions, Mg/yr;
C = chromium concentration, mg/dscm;
Q = volumetric gas flow rate, dscmm; and
t = annual operating time, hr/yr for plating tanks.
3.2.2 Emission Factors
In the case of chromium electroplaters, emissions data are
sufficient in both quantity and quality to establish reliable and
accurate emission factors to estimate uncontrolled emissions from
hard and decorative chromium electroplaters. The emission
factors are expressed in terms of weight of hexavalent chromium
in milligrams (mg) divided by the electrical input in ampere-
hours (current applied times duration). The emission factors for
hard and decorative electroplaters are 10 mg/amp-hour and 2
3-5
-------
mg/ amp-hour, respectively. Providing that there exist base year
records that reliably report the total amount of current consumed
and hours operated, annual uncontrolled emissions can be
calculated using the following equation:
ER = (EF) (A) (T) (ID'9)
where, ER = annual chromium emissions, Mg
EF = emission factor, mg/Ah
A = annual current consumption, amperes
T = annual operating time, hours
If base year records are incomplete, then the applicant
cannot use the emission factor approach to determine base year
emissions. In the case of chromic acid anodizers, currently
available emissions data are too limited to establish a reliable
emission factor for use in determining base year emissions.
3.3 DEMONSTRATION OF EARLY REDUCTION
Regardless of the approach employed to determine base year
and post-reduction annual emissions, the calculation of the
percent reduction achieved is made using the following equation:
i.
%Reduction=(l- — 2)100
ERp
Where: ERb = annual emissions in base year, Mg
ERp = annual emissions after reduction, Mg
Because performance data are available in sufficient
quantity and quality to support the conclusion that packed-bed
scrubbers applied to hard chrome and permanent type fume
suppressants added to decorative chrome and anodizers will
achieve reductions in emissions of 95 percent or greater, an
acceptable alternative to calculation could be the application of
controls by themselves. If the base year condition is no control
3-6
-------
and the early reduction is achieved by the installation of a
packed-bed scrubber for hard chrome or a permanent type fume
suppressant for decorative chrome and anodizers, the installation
of the scrubber or the use of the fume suppressant alone should
be considered adequate demonstration that a 95 percent reduction
is achieved.
An acceptable scrubber design should include a counter-
current water spray section, a packed-bed section, and a mist
elimination section. The bed should consist of an appropriate
packing media, 12 inches or more in thickness, with provisions
for continuous or periodic washdown. The mist eliminator section
should include as a minimum a standard chevron-blade mist
eliminator. The scrubber should be sized so that the face
velocity across the scrubber is about 500 feet per minute. An
acceptable fume suppressant is one which maintains the surface
tension of a plating bath at 40 dynes/centimeter or lower.
3-7
-------
4.0 ETHYLENE OXIDE STERILIZATION
Ethylene oxide (EO) is used as a sterilant/fumigant in the
production of medical equipment supplies, in miscellaneous
sterilization and fumigation operations, and at hospitals. A
diagram of a sterilization/fumigation cycle is presented in figure
4-1. Presterilization conditioning consists of heating and
humidifying the product in a separate room prior to sterilizing;
this will facilitate the penetration of EO into the product. After
conditioning, the product is placed in the empty sterilization
chamber. The chamber is evacuated using a vacuum pump and then
filled with either pure EO or a mixture of EO and
chlorofluorocarbons or carbon dioxide. When sterilization is
complete, the chamber vacuum pump is used to evacuate the chamber.
This pumping lasts at least ten minutes. After evacuation, the
chamber is filled with air or other gases, such as nitrogen or
carbon dioxide, to increase the rate at which EO is diffused from
the product. This "air wash" lasts from two to fifteen minutes. The
evacuation and air wash steps are repeated until the desired amount
of EO has been removed from the chamber. At the completion of the
last evacuation, the chamber door is opened and a fan at the rear
of the chamber is turned on to draw air through the chamber. This
air flow protects workers by drawing EO to the rear chamber exhaust
vent, which vents to the atmosphere. Chamber exhaust emissions are
a function of the number of evacuation/air wash cycles.
Practically all of the EO used in the steriliztion/fumigation
process is estimated to be emitted from three sources: (1) the main
sterilizer exhaust (i.e., the vent from the vacuum pump/liquid
separator), the aeration room or chamber, and the chamber exhaust
vent. Uncontrolled emissions from these sources are assumed to be
95, 3, and 2 percent of the EO use, respectively.
Available control techniques including acid scrubbers,
catalytic oxidizers, and flares can achieve emission reductions of
approximately 99%. Therefore, a 90% emission reduction of total EO
emissions can be achieved by controlling the main sterilizer
4-1
-------
The Sterilization Cycle
1
PRESTERILIZATION
ROOM
i
to
TO ATMOSPHERE
OR CONTROL DEVICE
GAS
01- Presterilization Conditioning
o 2 - Sterilization
• 3 - Evacuation
I
WAREHOUSE
AERATION
ROOM
I
^^ ^^
0
/ u
2
-------
exhaust stream.
4.1 TECHNIQUES FOR ESTABLISHING BASELINE HAP EMISSIONS
For facilities without add-on controls, emissions are equal to
the amount of EO used in the sterilization chamber; an estimate of
annual EO use can be made by using annual inventory data.
Facilities with existing add-on controls must estimate the
effectiveness of the existing control system and estimate emissions
using the amount of EO used in the sterilization chamber.
4.2 TECHNIQUES FOR ESTABLISHING 90% HAP EMISSION REDUCTION
Uncontrolled Facilities
An emission mass-in/mass-out approach will be used to estimate
control efficiency for both catalytic oxidizers and scrubbers.
Tests should be run on an empty chamber.
Mass-in
Mass into the control unit can be estimated by weighing the EO
supply cylinders before and after use to determine the amount of EO
in the chamber. Alternatively, mass in the chamber after evacuation
can be calculated by using concentration and chamber volume.
Concentration can be obtained by either using the ideal gas law or
a gas chromatograph. Mass into the control unit is the difference
between the EO charged to the chamber and the EO remaining in the
chamber. The test need be run only on the first evacuation cycle.
Mass-out
Mass out of the control unit is estimated by measuring flow
rate and EO concentration with EPA methods 2,2A,2C,or 2D and 18
respectively. For packed-bed scrubbers and catalytic oxidizers flow
rate and concentration can be measured directly. However, for a
reaction/detoxification tower, a flow must be induced to increase
the exit flow to a measureable rate.
4-3
-------
Control Efficiency
The control efficiency is calculated by the following
equation:
Control Efficiency - (1 - (MO/MI)) x 100
where MO = mass out of control device
MI « mass into control device
4-4
-------
APPENDIX A
CALCULATION WORKSHEETS FOR ESTABLISHING
BASE YEAR AND POST-REDUCTION HAP EMISSIONS
FROM SOCMI SOURCES
A-l
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM PROCESS VENTS
HAP: Date:
Year: Calculator:
Process Vent Identification:.
Description:
Process Conditions/Samplinq
Date of flow measurement
Method of flow measurement
Date of concentration measurement
Method of concentration measurement
(if not an EPA Method give a brief
description and attach protocol)
Describe any problems encountered
during testing_
Production rate during flow determination (Ibs/hr)
Production rate during sampling (Ibs/hr)
Average production rate for the year (Ibs/hr)
Stream Characteristics
Annual average vent stream flow rate
(ft3/min) = Q
Annual average HAP concentration (ppmv) = C
Annual hours of operation (hrs) = h
Vent stream discharge temperature (°F) = T
HAP molecular weight (Ib/lb-mole) = MW
Pressure at point of discharge (psia) = P
HAP high-risk weighting factor = FHj^
Control
Control device
HAP control efficiency (%) = eff
Calculations5
Uncontrolled Emissions (Ey) = 2.54E-09 0 C h MW P
T + 460
Uncontrolled Emissions (Ey) = 2.54E-Q9 ( ) ( ) ( ) ( )
( ) +460
Mg/yr
A-2
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM PROCESS VENTS (CONCLUDED)
HAP Emissions (EHAP) = En (1 - eff/100)
HAP Emissions (EHAP) = (1 - /100;
Mg/yr
Weighted HAP Emissions =
Weighted HAP Emissions =
If the conditions during testing are not representative of base
year of operation, make the appropriate extrapolation below and
explain:
If the flow or concentration were not measured using an EPA
reference method, EPA conditional method or validated using
Method 301, provide justification and supporting calculations:
Expression provided in "Procedures for Establishing Base Year
and Post-Reduction HAP Emissions" to convert flow and
concentration into an annual mass rate; the 3.94E-08 constant is
based on the ideal gas law.
A-3
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HA? EMISSIONS
FROM FIXED ROOF STORAGE TANKS
HAP: Date:
Year: Calculator:
Tank designation:
Product:
Tank Characteristics
Inside diameter, (ft) =D
Height, (ft) =HT
Capacity, (gal) = FI P- ll * 7.48 3*1. > =v
4 ft3
if not known
Roof color
Shell color
Vapor space height, (ft)a =H
Ambient Conditions
Average atmospheric pressure (psia) =PA
(defaults 14.7 psia)
Average ambient diurnal temperature =AT
(°F)°
Average annual ambient temperature =Ta
(°F)
Bulk Liquid Characteristics
Stored liquid temperature (°F)C =TS
Total throughput per year (gal) =AN
Number of turnovers per year1-* =N
Molecular weight of HAP (Ib/lb mole) =MVi
Vapor pressure of stored material (psia) =P
Partial pressure of the HAP at liquid =Pj_
conditions (psia)
HAP high-risk weighting factor ~FHR
Adjustment Factors
Paint factor (see Table 2-3) =FP
Small diameter tank factor6 =C
Turnover factor-^ =K
Product factor1? =K
•N
A-4
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM FIXED ROOF STORAGE TANKS (continued)
Control
Control device
HAP control efficiency (%)
Calculations11
Breathing Loss (M9/Yr) =
LB = 1.02E-05MVi( pP_p
°'68
= 1.02E-05(
Mg/yr
Working Loss (Mg/yr) = Lw = 1.09E-08 My^
= 1.09E-08 ( ) ( ) (
Mg/yr
Total Loss (Mg/yr) =
TL = LB + LW = (
) =
=eff
—i
P
)()()(
Mg/yr
If a control device is employed,
HAP Emissions (EHAP) = Total Loss (1 - eff/1001
= (1 - /100)
Mg/yr
A-5
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM FIXED ROOF STORAGE TANKS (continued)
Weighted HAP Emissions = E
= (
alf vapor space height is unknown or shell, assume H equals one
half tank height. If tank has a cone roof, adjust vapor space
height by adding 1/3 of height of cone.
blf average ambient diurnal temperature change is unknown, assume
20°F.
GStored liquid temperature may be approximated from average
annual ambient temperature. See Table 2-2.
^ = where N = number of turnovers per year
v AN = total throughput per year (gal)
V = tank capacity (gal)
eFor D >. 30ft, C=l; For 6 <. D < 30ft, C=0 . 0771D-0 . 0013D2-0 . 1334 .
fFor turnovers > 36, KN = (180 + N)/(6 * N)
where KN = turnover factor (dimensionless)
N = number of turnovers per year
For turnovers £ 36, KN = 1
9KC = 1.0 for volatile organic liquids
Expression for computing HAP emissions are from "Procedures for
Establishing Base Year and Post-Reduction HAP Emissions." The
calculation procedure is consistent with AP-42.
A-6
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM INTERNAL FLOATING ROOF STORAGE TANKS
HAP: _ Date:
Year: _ Calculator
Tank designation: _
Product :_ _
Tank Characteristics
Inside diameter, (ft)
Rim Seal type:
_
Number of columns3 _ = Nc
Effective column diameter (ft)b _ = Fc
Ambient Conditions
Average atmospheric pressure (psia) _ = PA
Average annual ambient temperature (°F) _ = T
Bulk Liquid Characteristics
Stored liquid temperature (°F) _ = Ts
Total throughput per year (bbl/yr)
[Note: 42 gal/bbl] _ = Q
Vapor molecular weight of stored _ = My
material (Ib/lb-mole)
Molecular weight of HAP (Ib/lb-mole) _ • = Mv .
True vapor pressure of stored
material at bulk liquid
conditions (psia) _ = P
Partial pressure of HAP (psia) _ = PI
Liquid density (Ib/gal) _ = WL
HAP high-risk weighting factor _ = FHR
Factors
Rim seal loss factor (Ib mole/ft yr) ;
obtain from Table 2-4 _ = KR
Product factor (dimensionless) _ = Kc
Shell clinage factor (bbl/1000 ft2) /
obtain from Table 2-9 _ = C
Deck fitting loss factor _ = FF
Deck seam loss factor _ =KD
(Ib-mole/ft yr)d
Deck seam length factor; _ =FD
obtain from Table 2-7
A-7
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM INTERNAL FLOATING ROOF STORAGE TANKS (CONTINUED)
Control
Control device
HAP control efficiency (%)
Calculations6
P* = (P/PA) (1 + (I - (P/PA)°-5)2)
= ( ) ( )/((!+(!-(
LM = (4.28E-04) QCWL
= (4-28E-04) ( ) ( ) ( )
) (
))°-5)2) =
1 1
=eff
psia
LR = KR D P* Mv KC Pi
1 2205 P
LF = FF P* M KC Fi
1 2205 P
LD =
P* Mv KC
2205 P
+ Lp +
Mg/yr
)J
2205 ( )
= ( ) ( ) ( ) ( )JL_
2205 (
If a control device is employed,
HAP Emissions (EHAP) = Total Loss (1 - eff/100)
= (1 - 7100)
Mg/yr
2205 (
A-8
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM INTERNAL FLOATING ROOF STORAGE TANKS (CONCLUDED)
aFor self-supported fixed roof or external floating roof tank,
Nc = 0. If Nc is unavailable, see Table 2-6.
blf Fc is unavailable;
FQ = 1.1 for 9 inch by 7 inch built-up columns;
0.7 for 8 inch diameter pipe column;
1.0 if column construction details are not known
CFF is determined using Table 2-10 and the following calculation
FF = [NF]_ KF]_] + [NF2 KF2] + ... + (NFN + KFN)]
^KQ =0.0 for welded deck and 0.34 for non-welded deck.
Expression for computing HAP emissions are from "Procedures for
Establishing Base Year and Post-Reduction HAP Emissions." The
calculation procedure is consistent with AP-42.
A-9
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM EXTERNAL FLOATING ROOF STORAGE TANK EMISSIONS
HAP: Date:
Year: Calculator:
Tank Designation:
Product:
Tank Characteristics
Inside tank diameter (ft) = D
Rim Seal Type:
Tank color:
Ambient Conditions
Average atmospheric pressure = PA
Ambient temperature (°F)
Average windspeed for the tank site (mph) = V
Bulk Liquid Characteristics
Density of the material stored (Ib/gal) = WL
Molecular weight of the material stored
(Ib/lb mole) = Mv
Molecular weight of HAP(lb/lb mole) = Mv.
True vapor pressure of the material x
stored (psia) = p
Partial pressure of HAP (psia) = Pj_
HAP high-risk weighting factor = F^
Factors
Seal factor; obtain from Table 2-8 = Ks
Seal windspeed exponent; obtain from
Table 2-8 = N
Product withdrawal shell clingage factor;
obtain from Table 2-9 = C
Product factor; 1.0 for VOL 1.0 = Kc
Total Roof Fitting Loss Factor3 = Fp
Calculation
P* = (P/PA)/((1 + (1 - (P/PA))°-5)2)
= ( ) ( )/((!+ (1 - ( ) ( ))°-5)2)
A-10
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM EXTERNAL FLOATING ROOF STORAGE TANK EMISSIONS (Cont.'d)
Calculations (cont.'d)
psia
fid MV P
Withdrawal Loss = Lw = 4.28E U4 QCWL vi i
D Mv P
= 4.28E"04 ( M_
Mg/yr
Seal LOSS = LSE = KSVNP*DMV.KC Pi
1 2205 P
Mg/yr
2205( )
Roof Fitting Loss =
FFP*MV,KC pi
F x 2205 P
= (
) (1.0)
2205( )
Mg/yr
Total LOSS = LT = Lw + LSE + LRF
+ ( ) + ( )
Mg/yr
A-ll
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM EXTERNAL FLOATING ROOF STORAGE TANK EMISSIONS (Cont.'d)
Calculations (cont.'d)
Weighted HAP Emissions =
aFF is determined using Tables 2-11, 2-12, and 2-13 and the
following calculation:
FF = [
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM EQUIPMENT LEAKSa
HAP: Date:
Year: Calculator:.
Process:
Component Component WT. % OVA Leak Emissions
ID Typea HAP of VOC Reading Emission of HAPC
Factor13
TOTAL EMISSIONS OF HAP
aRSLL = Pump Seals (Light Liquid); PSHL = Pump Seals (Heavy Liquid)/
VG = Valves (Gas/Vapor); VLL = Valves (Light Liquid); VHL = Valves
(Heavy Liquid); PRV = Pressure Relief Valves (Gas/Vapor); OE = Open-
Ended Lines; CS = Compressor Seals; SC = Samplings Connections;
F = Flanges
bFrom Table 2-14, 2-15, or correlation data.
c(Wt. % HAP)/100 * (Leak Emission Factor)
A-13
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM LOADING OPERATIONS
HAP:
Year:
Date: _
Calculator:
Loading Operation:
Loading Parameters
Cargo carrier (tank truck, rail car, etc.)
Mode of operation (choose from Table 2-16)
Annual volume of liquid loaded (gallons)
Temperature of liquid loaded (°F)
Weight percent HAP in the loaded material
True vapor pressure of the HAP loaded (psia)
[Note: For mixtures, use the HAP partial
pressure]
Molecular weight of the HAP (Ib/lb-mole)
Saturation factor (see Table 2-16)
HAP high-risk weighting factor
Control
Control device
HAP control efficiency (%)
Calculationa
= G
= P
M
s
FHR
= eff
Uncontrolled Loading Loss Eu = 5.65E-06 s P M G
T + 460
Uncontrolled Loading Loss Eu = 5.65E-06 ( ) ( ) ( ) (
( ) +460
Mg/yr
HAP Emissions (EHAP) = Eu (1 - eff/100)
(1 - /100)
Mg/yr
A-14
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM LOADING OPERATIONS (CONCLUDED)
Calculation (continued)
Weighted HAP Emissions = E
= (
Calculation worksheet and procedure from "Procedures for
Establishing Base Year and Post-reduction HAP Emissions."
This procedure is consistent with AP-42.
A-15
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM WASTEWATER SOURCES
HAP: Date:
Year: Calculator:
Wastewater Stream Identification:.
Wastewater Stream Description:
Process Conditions/Sampling
Date of flow measurement
Method of flow measurement
Date of concentration measurement
Method of concentration measurement
Production rate during flow determination (Ibs/hr)
Production rate during sampling (Ibs/hr)
Average production rate during base year (Ibs/hr)
Stream Characteristics
Average annual flow rate during discharge
(1pm) = Q
Average annual HAP concentration (mg/1) =<--VOHAJ?
Fraction of HAP that would be emitted
(see Table 2-14) = fei
Fraction of HAP that would be measured
by Method 25D/18 (see Table 2-14) = fmj_
HAP high-risk weighting factor = FHR
Control
Control device
HAP control efficiency (%) = eff
Calculations5
Wastewater Emissions (WEU) = 5.26E-04 Q CVQHAP fei
fm,1
A-16
-------
Source:
CALCULATION WORKSHEET FOR ESTABLISHING HAP EMISSIONS
FROM WASTEWATER SOURCES (CONCLUDED)
Wastewater Emissions Potential (WEn) = 5.26E-04 ( ) ( )(_
Mg/yr
HAP Emissions (EHAP) = WEU (1 - eff/100)
(1 - 7100)
Mg/yr
Weighted HAP Emissions = EHAp FHP
= ( ) ( )
Mg/yr
aCalculation worksheet and procedure from "Procedures for
Establishing Base Year and Post-reduction HAP Emissions".
A-17
-------
TECHNICAL REPORT DATA
(Pleat read instructions on the reverse before completing/
1. REPORT NO.
EPA-450/3-91-012a
2.
3. RECiP
4. TITLE AND SUBTITLE
Procedures for Establishing Emissions for Early
Reduction Compliance Extensions - Volume 1
5. REPORT DATE
February 1992
6. PERFORMING ORGANIZATION COOE
7. AUTHOR(S)
8. PERFOR
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning and Standards
Environmental Protection Agency
Research Triangle Park, NC 27711
10. PROGRAM
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Air Quality Planning and Standards
Environmental Protection Agency
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Regulations have been proposed governing compliance extensions for Early Reductions
of Hazardous Air Pollutants (HAP). The regulations allow a six year MACT "standard
compliance extension for sources that achieve HAP reductions of 90% (95% for
particulates) from a base year of 1987 (or more recent base year). This document
includes acceptable emission estimating techniques that can be used when source
testing is not feasible. This document includes techniques for synthetic organic
chemical manufacturing, ethylene oxide sterlization, and chromium electroplating.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
Air Pollution Loading Operation
Chromium Electroplating MACT Standard
Ethylene Oxide Sterlization Compliance
Storage Tanks
Process Vents
Equipment Leaks
Wastewater
Air Pollution Control
|18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS i Tins Rap
Unclassified
93
20. SECURITY CLASS (Tins page I
Unclassified
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
-------
U.S. Environmental Protection Agency
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th Floor
Chicago, IL 60604-3590
------- |