United States Office of Air Quality EPA - 450/1 -90-003
Environmental Protection Planning and Standards May 1990
Agency Research Triangle Park NC 27711
Air/Superfund
<&EPA AIR / SUPERFUND
NATIONAL TECHNICAL
GUIDANCE STUDY SERIES
Air Stripper
Design Manual
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EPA - 450/1-90-003
AIR STRIPPER DESIGN MANUAL
By
Ashok S. Damle
Tony N. Rogers
Research Triangle Institute
P.O. Box'12194
Research Triangle Park, N.C. 27709
Prepared for:
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Durham. NC 27711
Project Officer: James Durham
May 1990
U.S. Rnvi.:.;-:;rc-.:.:i P
r\o „;,.. „ f . • •
K C-,", (' • ' \,»
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TABLE OF CONTENTS
Section Page No.
1 INTRODUCTION 1
2 AIR STRIPPER MODEL 3
2.1 ASPEN Process Simulator 3
2.2 Air Stripping Process 3
2.3 Air Emission Control Options 11
2.4 Physical Properties 14
3 ESTIMATION OF CAPITAL AND ANNUALIZED COSTS 15
3.1. Capital Cost of a FRP Stripping Tower 15
3.2 Capital Cost of a Liquid Circulating Pump 17
3.3 Capital Cost of a Gas Blower 17
3.4 Capital Cost of Storage Tanks 17
3.5 Capital Cost of a Catalytic Oxidation
Unit 18
3.6 Capital Costs of a Carbon Adsorber Unit 18
3.7 Total Annualized Costs 20
4 NET AIR EMISSIONS ANALYSIS 23
4.1 Carbon Adsorption Process 24
4.2 Catalytic Oxidation Process 25
5 "ASPAIR" INTERACTIVE SOFTWARE 27
5.1 Overview 27
5.2 Interactive Front-End Program 27
5.3 Installation and Start-Up Procedures 29
5.4 Entering Information 30
5.5 Creating a Custom ASPEN Input File 32
6 US ING ASPEN ON THE VAX 37
6.1 Setting Up a User Account 37
6.2 Accessing the VAX Using Personal Computers.... 38
6.3 Running the ASPEN Program on the VAX 41
6.3.1 Logging in to the NCC VAX Cluster
Computer 41
6.3.2 Transferring Files From a Personal
Computer to the VAX 42
6.3.3 Copying Library Files to User
Account for First Time Users 44
6.3.4 Running the ASPEN Air Stripper
Program on the VAX 44
6.3.5 Transferring Output Files from the
EPA-VAX to a Personal Computer 46
6.3.6 Logging Out Procedures 46
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7 GENERATION OF SIMULATION REPORT 47
7.1 Report Output Generation 47
8 CASE STUDIES AND GRAPHICAL PROCEDURES 49
8.1 Introduction 49
8.2 Air Stripper Performance and Design
Calculations 49
8.3 Capital and Annualized Costs of Air
Stripper 55
8.4 Capital and Annualized Costs of a
Catalytic Oxidation Unit 60
8.5 Capital and Annualized Costs of a
Carbon Adsorber Unit 60
9 SUMMARY 69
10 REFERENCES 71
APPENDIX A: HENRY'S LAW CONSTANTS AND REFRACTIVE
INDICES FOR SELECTED ORGANIC CHEMICALS
APPENDIX Br A SAMPLE CASE STUDY REPORT
RATING MODE - CARBON ADSORPTION OPTION
APPENDIX C: A SAMPLE CASE STUDY REPORT
DESIGN MODE - CATALYTIC OXIDATION OPTION
APPENDIX D: SAMPLE FORM N258 - EPA ADP IBM, LMF, & VAX
ACCOUNT AND USER REGISTRATION
APPENDIX E: EXAMPLE OF COMMUNICATION PARAMETERS SETTING
ON CROSSTALK STATUS SCREEN
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LIST OF TABLES AND FIGURES
2 Cost Assumptions (ASPAIR Air Stripper Model)
8 Stripper Efficiency vs. Henry's Law Constant
Parameter = G/L (vol./vol.). Low Efficiency
Range
9 Stripper Efficiency vs. Henry's Law Constant
Parameter = G/L (vol./vol.), High Efficiency
Range
Paee No.
1 Henry's Law Constants and Minimum G/L Ratio
Required for Complete Removal of Common VOCs ..... 10
16
3 Emission Factors From AP-42 for the Fuel
Combustion Products 24
4 Possible Surrogates for Some Volatile Organic
Chemicals Not Included in ASPEN Library 35
5 Regional ADP Coordinators 39
6 Mass Transfer Coefficient as a Function of
Henry ' s Law Constant 53
7 Equilibrium Carbon Adsorption Capacities for
Various VOCs 68
Figures
Page No.
1 Schematic of the Air Stripping Process 4
2 Run Procedure for ASPEN Air Stripper Model 28
3 Main Menu for "ASPAIR" Interactive Program 31
4 "Component Selection/Properties" Screen 33
5 Chemical Selection Menu 34
6 Example of the Port Selection Menu 40
7 Example of Login Screen and On-Screen Bulletin
on NCC VAX„
51
52
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10 Tower height as a Function of Stripping Factor,
Parameter = VOC Removal Efficiency 54
11 Air Stripper - Capital Investment, VOC Removal
Efficiency = 90% (1989 dollars) 56
12 Air Stripper - Annualized Costs, VOC Removal
Efficiency = 90% (1989 dollars) 57
13 Air Stripper - Capital Investment, VOC Removal
Efficiency = 99*. (1989 dollar) 58
14 Air Stripper - Annualized Costs, VOC Removal
Efficiency = 99%, (1989 dollars) 59
15 Catalytic Oxidizer - Capital Investment,
Parameter - G/L Ratio (vol./vol.)
(1989 Dollars) 61
16 Catalytic Oxidizer - Annualized Costs,
Parameter - G/L Ratio (vol./vol.)
(1989 Dollars) 62
17 Carbon Adsorber - Capital Investment
on-site regeneration (1989 Dollars ) 64
18 Carbon Adsorber - Annualized Costs
on-site regeneration (1989 Dollars) 65
19 Carbon Adsorber - Capital Investment
off-site regeneration (1989 Dollars) 66
20 Carbon Adsorber - Annualized Costs
off-site regeneration (1989 Dollars) 67
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SECTION 1
INTRODUCTION
Air stripping of volatile organic chemicals from wastewater is an
effective method of removing volatile organic chemicals (VOCs) from
contaminated water. However, this method also transfers pollutants from
the water to the gas phase, and the resulting air emissions may need to be
appropriately controlled.
A computer model package "ASPAIR" was developed in this project to
describe the air stripping process along with processes for controlling the
air emissions. This package is integrated with a commercially available
ASPEN process simulator, and consists of 1) ASPEN user model subroutines in
FORTRAN language describing the air stripping and carbon adsorption
processes, 2) a "front-end" program for user data entry, and 3) templates
for creating input files readable by ASPEN simulator. The "front-end-
interactive PC-based software was developed to allow a user to create a
customized problem input file and run an ASPEN air stripping simulation
without any knowledge of ASPEN programming.
A number of simulations were carried out with the ASPAIR model package
to determine the effect of important parameters on the performance and cost
of the air stripper and the air emission control units. The results from
these case studies were used for developing graphical procedures to provide
a quick approximate method of generating performance and cost estimates.
This design manual describes the ASPEN user models developed for the
air stripping process and air emissions control processes, the "ASPAIR"
interactive software, and the graphical "short-cut" procedures.
Instructions are provided for using these items.
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SECTION 2
AIR STRIPPER MODEL
2.1 ASPEN Process Simulator:
The ASPEN process simulation software, VAX/VMS version 7.0, is
available to EPA/OAQPS for evaluating the performance and cost of waste
treatment processes. ASPEN is an acronym representing "Advanced ^System for
£rocess Engineering," a software package developed for U.S. Department of
Energy (1982)1, to aid in engineering calculations. A number of features
make ASPEN suitable for modeling waste treatment systems: (1) modular
construction of flowsheets; (2) built-in thermodynamic routines; and
(3) ability to add user models developed for specific applications. An
important advantage of using the ASPEN process simulator is the extensive
physical property database available for a large number of chemicals. A
user can set up an ASPEN problem for a "grass-roots" design (design mode)
or a simulation that rates an existing process under new operating
conditions (rating mode).
In the ASPEN process simulator, various unit operations are
represented by their respective models stored in a library of Fortran
subroutines. Models for the unit operations not available in this ASPEN
library must be provided by the user and compiled in the ASPEN library. In
this project, ASPEN user models were developed for an air stripper, as well
as for a carbon adsorber used to control air emissions.
2.2 Air Stripping Process:
In a typical air stripping process, wastewater containing volatile
organic chemicals is countercurrently contacted with air in a packed tower.
A schematic of the overall process is shown in Figure 1. In addition to a
packed stripping tower, the process consists of a wastewater pump, a gas
blower, optional wastewater storage tanks, and an optional unit operation
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Contaminated
Water 1
Storage
Tank
(Optional)
Pump
voc
Control
(Optional)
Packing
Air
"Clean" Water
Figure 1. Diagram of the air stripping process.
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(e.g., catalytic oxidation or vapor-phase carbon adsorption) for control of
air emissions. The volatile organics are transferred to the gas phase
during the intimate gas-liquid contact. The stripped water may further be
treated in an optional carbon adsorber polishing bed. The treated effluent
water is either recycled as process water or discharged. In case of a
groundwater cleanup operation the treated water may be pumped back into the
ground.
A vertical packed tower is a simple gas-liquid contacting device
consisting of a cylindrical shell containing a support plate for the
packing material and a liquid-distributing device designed to provide
effective irrigation of the packing. The wastewater enters at the top of
the column and flows by gravity countercurrent to the air which is
introduced below the packing. Stripping occurs because the dissolved
organics in the wastewater tend to volatilize into the gas phase until
their vapor and liquid concentrations reach thermodynamic equilibrium. For
dilute aqueous mixtures of volatile organics, the equilibrium distribution
of a pollutant between the gas phase and water can be described adequately
by Henry's Law:
p = H c
(1)
where, p = partial pressure of a VOC in the gas phase, atm,
H = Henry's Law constant, atm-m3/gmole, and
c = concentration of the VOC in the aqueous phase, gmole/m3.
Henry's Law constant of a VOC determines its volatility and ease of
stripping. Like vapor pressure, this constant strongly depends upon the
temperature and its variation with temperature may be expressed by the
Clausius-Clapeyron relationship2:
(T)
AHV
Ln I — I = - — I — - — l (2)
H0' R \ T T0
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where,
H0 =
*v =
R =
T =
TO =
Henry's law constant at a desired temperature, T,
atm-m3/gmole,
Henry's law constant at a reference temperature, T0,
latent heat of vaporization, cal/gmole,
gas constant, cal/gmole-°K
stripper operating temperature, °K,
reference temperature, K,
The major parameters affecting an air stripper performance are the Henry's
law constant for each VOC, the liquid loading rate, and the gas to liquid ratio.
The gas and liquid loading rates and various physical properties affect the mass
transfer coefficients for each VOC, whereas, the Henry's law constant affects
the concentration driving force. The height of a packed tower is designed for a
certain desired VOC removal efficiency and the column diameter is designed from
flooding correlations to provide a desired pressure drop. In the ASPAIR air
stripper model a pressure drop of 0.5 in-H20/ft [0.41 kPa/m] of packing is
assumed for column design calculations. The corresponding graphical flooding
correlation given in textbooks2 may numerically be expressed as:
Y = 1.0421 - 0.275 X + 0.06966 X2 - 0.006102 X3
(3]
where, X = Log
L'
0.5
(-1.250667)
Y = Log
1.332 G'2 cf uL°'2
PL °G
(-4.15723)
L' = liquid loading, Kg/sec-m2
G' = gas loading, Kg/sec-m2
PL = liquid density, Kg/m3
PG = gas density, Kg/m3
Cf = packing factor
Ur - liquid viscosity, Kg/m-sec
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The air stripper operation may reasonably be assumed to be isothermal, under
atmospheric pressure, and with constant molal overflow (negligible water
evaporation). In addition the equilibrium and operating lines may be assumed to
be linear. The assumption of linear equilibrium line also implies that Henry's
Law is valid for each volatile organic chemical at the concentrations
encountered in the stripping column.
The mass transfer model of Onda et al . (1959)3 is used in the air stripper
model to calculate an overall liquid-phase mass transfer coefficient, KLa . This
coefficient is needed to determine the column height for a desired removal
efficiency or to predict the VOC removal efficiencies in an existing column.
The overall mass transfer coefficient is based on the two-resistance theory,
which states that the total resistance to interphase-(gas-liquid) mass transfer
is the sum of a gas-phase and a liquid-phase resistance. Physically, KLa may be
thought of as a first-order rate constant for mass transfer (based on the
liquid-phase driving force) which is the product of an overall intrinsic mass
transfer coefficient, KL (m/sec). times the specific interfacial mass transfer
area, a (m"1 ) .
The individual liquid and gas phase mass transfer coefficients, kLa and kGa,
depend upon the gas and liquid loadings, the physical properties of the phases
(e.g. viscosity, and density), the packing material, and the diffusion
coefficients of the VOCs in each phase. The overall liquid phase mass transfer
coefficient. KLa. depends strongly upon the Henry's law constant for a given
VOC:
1 P 1
KLa H kGa kLa
where, KLa = overall mass transfer coefficient, sec'1
a = specific wetted surface area of the packing material
total pressure, atm
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H = Henry's law constant for a given VOC in the air-water
system described as atm-(gmole/m3)gas/(gmole/m3)
k(ja = mass transfer coefficient in the geis phase, sec"1
and, kL» = mass transfer coefficient in the liquid phase, sec"1
The various engineering assumptions described earlier allow integration of
the concentration driving force over the entire packing height of the column to
obtain the number of transfer units (NTU) for a given VOC removal efficiency.
The overall mass transfer coefficient may be used to determine the packing
height equivalent to a single transfer unit (HTU). The air stripper model can
thus predict the packing height required for a specified set of operating
conditions and a desired VOC removal efficiency:
L R p 100 R - E -|
z = . Ln ....(5)
KLa (R-l) L R (100 - E) -"
HTU NTU
where: Z = Packing height, m,
E = VOC removal efficiency. %,
L = liquid loading, (m3 of liquid)/m2-sec.
K^a = overall liquid phase mass transfer coefficient, sec'1.
HTU = height of a transfer unit, m,
NTU = number of transfer units, dimensionless
R = "stripping factor", the operating volumetric G/L ratio divided by
the minimum G/L ratio required for 100 percent removal of the VOC in
an ideal column, which is expressed as:
(G/L) operating
R =
P / H
P = Column pressure, atm,
H = Henry's law constant for the VOC. atm-(gmole/m3)gas/(gmole/m3)liquid
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The G/L rat.o is based upon the volumetric gas and liquid phase
loadings in the stripper. Note that the total active (packed) tower height
is the product of the HTU and NTU. Because the HTU is roughly
proportional to the height equivalent of a theoretical plate (HETP)4, the
NTU provides an approximation of the number of required theoretical (ideal)
trays required for the same degree of separation of the desired VOC. The
actual number of trays will depend upon a tray efficiency and will be
somewhat greater than the NTU value.
The stripping factor, R, is given by the ratio of the actual G/L ratio
used and the theoretical minimum G/L ratio required for 100 percent removal
of the VOC. The minimum G/L ratio is inversely proportional to the Henry's
Law constant and is given by P/H. The operating G/L ratio is based upon
the volumetric gas and liquid phase loadings in the stripper. For a
stripping factor R = 1, an infinite tower height will be required for
attaining 100% removal of the VOC. Thus, in practice the stripping factor
should be significantly greater than unity to approach complete VOC removal
with a reasonable tower height. For a stripping operation with the R value
less than unity, it can be shown that the maximum possible percent VOC
removal will be limited to 100. R. The Henry's law value of a VOC can thus
determine whether a VOC can be stripped or not with a practical G/L ratio.
Henry's Law constant values for some of the common VOCs and the minimum G/L
ratio required for their complete removal are shown in Table 1.
Equation (5) may be rearranged to calculate the VOC removal efficiency,
E. in an existing stripper with a packing height, Z, for a specified set of
operating conditions:
eQ -l
E = 100 R . ------------ .......................... (5'}
ReQ -1
KLa R-l
where: Q = Z • -------- .
L R
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TABLE 1. HENRY'S LAW CONSTANTS AND MINIMUM G/L RATIO
REQUIRED FOR COMPLETE REMOVAL OP COMMON VOCs
VOC Name
Vinyl Chloride
Carbon Tetrachloride
Tetrachloroethylene
1,1 Dichloroethane
Trichloroethylene
Toluene
Benzene
Chloroform
Dichlorome thane
1,2 Dichloroethane
1.1,2 Trichloroethane
I so-propyl alcohol
Methyl Ethyl Ketone
Acrylonitrile
Acetone
H @ 25°C
atm-m^/gmole
8.60E-2
3.00E-2
2.90E-2
1.54E-2
9.10E-3
6.68E-3
5.50E-3
3.39E-3
3.19E-3
1.20E-3
7.40E-4
1.50E-4
1.25E-4
8.80E-5
2.50E-5
Log(H)
-1.066
-1.523
-1.538
-1.812
-2.041
-2.175
-2.260
-2.470
-2.496
-2.921
-3.131
-3.824
-3.903
-4.056
-4.602
(G/L)min @ 25'C
v/v
0.3
0.8
0.8
1.6
2.7
3.7
4.5
7.2
7.7
20.3
33.1
163.1
195.7
278.0
978.0
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This allows the ASPAIR air stripper model to be used in the performance
rating mode for existing strippers to compare observed VOC removal
efficiencies with those predicted by the model. In the design mode an
active stripper height is determined for achieving a certain removal
efficiency for a designated VOC. Additional nonactive tower height (e.g.,
2 meters may be added to obtain total tower height
2.3 Air Emission Control Options:
The emission of the VOCs in the air stream from the stripper may be
controlled by suitable air emission control devices. Two air emission
control technologies are available to the user in the ASPAIR air stripping
model: catalytic oxidation and fixed-bed carbon adsorption. Catalytic
oxidation is a low-temperature (approximately 700° F) incineration unit
that uses methane as an auxiliary fuel to maintain the combustion
temperature for dilute organic vapors. A base metal oxide is usually used
as a catalyst, although more expensive noble metal oxides may also be used
in some applications. The catalytic oxidation process is simulated by
ASPEN as a simple stoichiometric reactor.
Amount of fuel (methane) needed is determined from the air inlet
temperature and flow rate, heating value of methane, heat recovery in the
oxidizer, and the desired operating temperature of the catalytic oxidizer.
The detailed procedures for designing a catalytic oxidation unit are
provided in a Control Cost Manual5 prepared by the Standards Development
Branch (SDB) of U.S. EPA/OAQPS. Almost all of the VOCs can be destroyed by
a catalytic oxidation unit provided adequate combustion temperatures and
gas residence time in the catalyst bed are used and the catalyst activity
is maintained by following an appropriate catalyst replacement schedule.
The sizing of a catalytic oxidizer involves determining the gas
throughput including the auxiliary fuel (methane) flow, selecting the
extent of heat recovery from the exhaust gas, and choosing an appropriate
space velocity through the catalyst bed. The space velocities range from
10.000 to 60,000 hr"1, whereas up to 70* heat recoveries are possible.
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Carbon adsorption has been shown to be an effective method for control
of air emissions of several VOCs. Because no carbon adsorption model
currently exists in the ASPEN library, an ASPEN user aodel was also
developed and installed in the ASPEN library to carry out carbon adsorber
design calculations. This carbon adsorption user nodel is based on a
Polanyi-type "universal isotherm" developed by Calgon Corporation to
estimate equilibrium capacities for various carbon adsorbents. For a given
type of carbon, in this case a Calgon BPL (4 x 10 mesh), a single measured
isotherm for n-butane serves as a reference for predicting the equilibrium
capacity of any chemical on that same adsorbent. This reference isotherm
is called the characteristic curve for the adsorbent, and its theoretical
relationship to the "adsorption potential" of the adsorbate is well
established6. The adsorption potential of a VOC at a given temperature is
related to its saturation ratio (i.e. the ratio ofthe VOC partial pressure
in the air stream to its saturation vapor pressure). By accounting for a
chemical's adsorbed (liquid) density and polarizability. its isotherm can
be predicted from the adsorbent's characteristic curve without experimental
data.
The equilibrium adsorption capacity of activated carbon (Calgon
BPL 4 x 10 mesh) for a VOC may be expressed as a fifth order polynomial
function of its adsorption potential:
Log(Q) = 1.71 - 1.46 x ID'2 F - 1.65 x 10~3 F2
- 4.11 x ID-4 F3 + 3.14 x ID'5 F4 - 6.75 x lO'7 F5 (6)
where. Q = equilibrium loading of VOC. (cc VOC liquid/100 g carbon)
F = adsorption potential of a VOC given by:
i
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PJ = partial pressure of the VOC, atm
Pv = equilibrium vapor pressure of the VOC, atm
T = carbon temperature, °K
Vm i = liquid molar volume of the VOC, cm3/gmole
T = relative polarizability, given by:
^n-heptane
B.J = polarizability of a component i per unit volume given by:
and, n = refractive index of the component i.
Assumptions in the carbon bed user model include: (1) additivity of the
equilibrium capacities of the VOC contaminants, which neglects competitive
adsorption effects; and (2) an overall "working factor" of 3 (three) that
accounts for mass transfer effects, almost 100% relative humidity in the
gas phase, and unused bed capacity at breakthrough. For a wastewater
stream containing several VOCs , equation (6) is used for each VOC to obtain
the equilibrium carbon capacity for that VOC. The amount of carbon
required for adsorbing an individual VOC for a given operating period is
calculated from the emission rate from the stripper and the equilibrium
capacity for that VOC. The total carbon requirement is obtained by adding
individual VOC carbon requirements and multiplying by a working factor.
Detailed procedures for sizing an adsorber facility are also provided by
the OAQPS/SDB Control Cost Manual5 (1990). Two options are available for
costing an adsorber system: on-site and off-site regeneration. On-site
regeneration of spent carbon by steam requires additional equipment such as
condenser and decanters as well as a source for steam. The off-site
regeneration option requires the user to provide the carbon regeneration
cost on a unit weight basis.
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2.4 Physical Properties:
The air stripper simulation model requires physical property data to
calculate mass and energy balances. Although ASPEN has a large physical
property library for several organic and inorganic chemicals, additional
properties (e.g., Henry's law constant and refractive index) must be
supplied to the model. Henry's law constants are needed for equilibrium
calculations and refractive index is related to the polarizability of a
chemical in adsorption calculations. Henry's Law constant values for a
number of common VOCs were reported recently7 and are adopted in the
present work. A supplementary library of these properties has been
prepared as a part of the ASPAIR software package so that the user does not
have to supply these physical properties for any of the ASPEN-recognized
chemicals. A listing of the Henry's law constants and refractive indices
included in this data library are given in Appendix A. Air-water Henry's
law constants for organic chemicals in the ASPEN library included in this
database are at a reference temperature of 25°C. These are extrapolated in
the model to the column operating temperature using the Clausius-Clapeyron
relationship given in Equation (2)^. The Henry's Law constants in Appendix
A are given atm-m3 of liquid/gmole units. These constants may be converted
to values at 25°C in atm-(gmole/m3)gas/(gmole/m3)ijqujd units by
multiplying with 40.875. The Henry's Law constant values in the latter
units may be used to determine the minimum (G/L) ratio required for
complete removal as well as the stripping factor at the operating (G/L)
ratio.
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SECTION 3
ESTIMATION OP CAPITAL AND ANNUALIZED COSTS
The ASPAIR model incorporates costing procedures developed by
EPA/OAQPS, Standards Development Branch (SDB) and published in the QAQPS
Control Cost Manual5 (1990). This manual provides cost correlations and
detailed design procedures for the carbon adsorber and catalytic oxidizer
units used for control of air emissions. A simple correlation was
developed to estimate cost of a stripper, made of fiber glass reinforced
plastic (FRP), based upon vendor communications.8-9 Costs of a gas blower,
liquid circulating pump, and associated ductwork were determined using the
recently published correlations10. The cost results are indexed for
convenience to January 1986 and can be adjusted to any desired year by
using an appropriate Chemical Engineering Plant Cost Index in the
calculations. Table 2 summarizes the assumptions used in the model to
determine total capital investment from the base equipment cost. The
absolute cost values generated by the ASPAIR model should be considered to
be accurate to within 30%. The various correlations used in the ASPAIR
model to calculate the base equipment cost of different items are described
below:
3.1 Capital Cost of a FRP Stripping Tower:
For atmospheric pressure operation the cost of a stripper vessel may be
based upon the column surface area. Recent communications with two
vendors8-9 indicated an approximate FRP vessel cost of 40 to 50 $/Ft2
(430 - 540 $/m2) column surface area. The higher value is currently used
in the model calculations. The cost of random dumped polypropylene 1"
saddle packing may be estimated at $15/Ft3 of packing volume; and that of a
liquid distributor and a packing support plate may be estimated at S100/Ft2
($l,080/m2) column cross sectional area. The accompanying ductwork cost is
estimated at $10/Ft ($33/m) length of the duct, with the length of the duct
assumed to be two times the total height of the tower.
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TABLE 2. COST ASSUMPTIONS (ASPEN AIR STRIPPER MODEL)
Instrumentation : 10* of Base Equipment Cost (BEC)*
Sales Tax & Freight : 8% of (BEC)
Purchased Equipment Cost (PEC) : (BEC)+(Instr.)+{Sales Tax &
Freight)
Total Installation Cost (Direct + Indirect) : 61% of PEC
Total Capital Investment (TCI) : (PEC) f (Total Installation Cost)
Direct Labor : 2 hours/shift for stripper and 1 hour/shift for
control unit
Supervision and Admin. Labor : 15% of Direct Labor
Maintenance Labor and Materials : 4% of TCI
Maintenance Labor for Emission Control Unit : 0.5 hr/shift
Overhead : 60% of (Direct Labor + Supv./Adm. * Maint.)
Utilities : Electricity requirement computed from pressure drop in
stripper and control unit, and gas flow rate; catalyst
replacement; natural gas costs; carbon regeneration
and replacement costs; steam and cooling water costs
Property Taxes, Insurance, and Admin. Charges : 4% of TCI
Capital Recovery : 10% over a 10-year service life
Total Annualized Cost : (TAG) Direct + Indirect Costs
Annual Operating Cost : TAG - Capital Recovery
for carbon adsorber and catalytic incinerator the cost of
instrumentation is usually included in BEC.
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3.2 Capital Cost of a Liquid Circulating Pu«p:
The graphical correlation provided by Hall et. al (1988)10 is used to
estimate the cost of a centrifugal liquid pump. The correlation provides
the cost of a pump as a function of the horsepower of the pump. This
correlation was converted to a function of the volumetric liquid flow rate
by assuming that about 100 Ft of water pressure head is generated by the
pump. The correlation may numerically be expressed as:
Cost of a liquid pump ($) = 929.2 (Qj)
0.3062 (7
where. Qi is the liquid flow rate in m3/hr. The cost is in 1988
dollars.
3.3 Capital Cost of a Gas Blower:
The graphical correlation provided by Hall et. al (1988)10 is used to
estimate the cost of a gas blower. The referred correlation provides the
cost of a blower as a function of the blower wheel diameter. This
correlation was converted to a function of the volumetric gas flow rate by
assuming the static pressure produced to be about 10 in. of water and
using an average gas flow rate value from a possible range of values for a
given wheel diameter. The correlation for a radial tip blade type blower
may numerically be expressed as:
Cost of a gas blower ($) = 1.1144 (Qg) 0-8477 {8)
where, Qg is the gas flow rate in m3/hr. The cost is in 1988 dollars.
3.4 Capital Cost of Storage Tanks:
An air stripping system may include storage tanks to provide inventory
of the feed water to the stripper. The cost of storage tanks directly
depends upon the volume of the tanks which in turn depends upon total
inventory time for the wastewater and the number of tanks present. The
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following correlation by (Corripio et. al, 1982)1* is represented
numerically assuming one day of inventory distributed in two tanks:
Cost of a storage tank ($) = 1.362[Exp(9.369 - 0.1045 X
t-0.045355 X2)] (9)
where, X = Ln(V) and,
V = Tank volume in m3 in the range 80 to 45,000 m3.
The cost predicted by this equation is in 1986 dollars and is for carbon
steel field erected tanks.
3.5 Capital Cost of a Catalytic Oxidation Unit:
Capital cost of a catalytic oxidation unit may be estimated from
correlations based upon the total gas flow through the incinerator (OAQPS
Control Cost Manual5, 1990). The cost also depend upon the extent of heat
recovery desired. The ASPAIR model assumes an oxidizer design with 50%
heat recovery. Corresponding cost correlation may be expressed as:
Cost of a Catalytic Oxidizer ($) = 904.15 QtO-5575 (10)
where. Qt is the total gas flow = stripper air *• fuel flow, in
std. m3/hr.
The cost is expressed in 1986 dollars. The stripper air flow directly
depends upon the waste flow rate and the G/L ratio used. The fuel
(natural gas) requirement of the incinerator primarily depends upon the
air flow rate entering the unit, heat recovery from the exhaust gas, and
the temperature of the incinerator maintained to assure complete VOC
destruction.
3.6 Capital Costs for a Carbon Adsorber unit:
Unlike a catalytic oxidation unit, the carbon adsorber capital cost
and the annual carbon requirement depend upon a large number of variables.
The OAQPS Control Cost Manual5 (1990), Chapter 4, provides detailed
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procedures for determining the annual carbon requirement, carbon bed size
and the capital cost.
Generally, for each VOC component in the air stream leaving the
stripper, an equilibrium carbon capacity must be determined. The
equilibrium capacity is a function of the VOC gas phase concentration and
the physical properties such as vapor pressure, molecular weight, liquid
density, and refractive index. The equation (6) is used to determine the
equilibrium capacity of the carbon for adsorption of a VOC. The annual
carbon requirement is then determined from the annual VOC emissions from
the stripper and the sura of the corresponding equilibrium capacities for
each VOC.
The capital cost of a carbon adsorber system is determined by
selecting a suitable adsorption/desorption cycle time and determining the
amount of carbon required for one adsorption cycle. The vessel dimensions
are next determined to house the required amount of carbon. Usually at
least two adsorber vessels are used, one for adsorption cycle and the
other for desorption cycle or unloading operations. Both vessels are
assumed to house the design amount of carbon. For cases requiring a large
amount of carbon more than two vessels may be used with appropriate
adsorption/desorption scheduling. The user has a choice of providing the
adsorption cycle time and the number of beds to be used in the model.
Like the stripper, the cost of an adsorber vessel may also be based upon
the surface area of the vessel:
Cost of carbon adsorber ($) = 271 s°-778 (11)
where, S is the vessel surface area in Ft2 in the range of 97 and 2100
Ft2. The cost is expressed in 1986 dollars.
For on-site carbon regeneration additional equipment is needed such as
a condenser, decanter and pumps. The total cost of the system may be
determined approximately5 from the cost of adsorber vessels and the cost
of initial charge of carbon:
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Cost of total system = Rc [ Cc + Cv N] - (12)
where, Rc = cost factor
= 5.82 (Q)-0.133
Q = gas flow rate in ACFM
Cc = cost of initial carbon charge
Cv = cost of adsorber vessel given by Equation (11)
and N = No. of adsorber vessels.
For off-site carbon regeneration option, the capital cost of carbon
adsorber system is simply given by CVN.
3.7 Total Annualized Costs:
The main components of the total annualized costs are also summarized
in Table 2, which primarily include labor costs, utilities, indirect annual
costs such as taxes, and depreciation costs. The depreciation costs depend
upon the equipment service life, interest rate, and the total capital
•investment cost.
The operating labor costs are relatively less dependent upon the waste
water flow rate and may assumed to be two hours per shift for the stripper
operation or about 2000 hours per year. The control unit operating labor
may be estimated at about one hour per shift. The operating labor costs
can thus be estimated using a typical labor rate for the local region. The
maintenance labor, miscellaneous, and depreciation costs are related to the
total capital investment costs as given by various factor:? in Table 2.
The utilities (electricity) costs primarily result from running the gas
blower, and depend upon the air stripper gas flow rate and the gas phase
pressure drop across the entire system (including the control unit).
Pressure drop across a packed column (stripper) may be estimated at about
0.5 inch of water per ft [0.41 kPa/m] of packing in the column, and a
carbon bed may be assumed to have a pressure drop of about 6" of water
[5 kPa]. A catalytic oxidizer with 50* heat recovery may be assumed to
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have a typical pressure drop of 10" of water. The ASPAIR model uses the
detailed procedure provided by the OAQPS control cost manual to calculate
pressure drop across a carbon adsorber. The following correlation may be
used to estimate the electricity cost requirement of a blower:
Electricity (blower) costs (S/yr) = 8.425 x 10~5 Qg AP 0 Ep/n (13)
where, Qg is air stripper gas flow in m3/hr,
AP is system pressure drop, kPa,
© is operating hours, hr/yr
Ep is electricity cost, $/Kwh
and, n is blower efficiency, (usually - 0.6)
The air stripper gas flow rate, Qg, is directly related to the
wastewater flow rate and the operating G/L ratio.
The control of air emissions also-involves additional operating costs.
The operating costs associated with a catalytic oxidizer are primarily the
annual fuel and catalyst replacement costs. These costs are directly
related to the stripper air flow rate. Amount of catalyst required depends
upon the space velocity used and the extent of replacement depends on the
catalyst life. The amount of methane used depends upon the operating
conditions such as oxidizer temperature, and heat recovery. The oxidizer
temperature is provided by the user and 50* heat recover is presently
assumed in the model.
The annual operating costs for a carbon adsorber primarily involve the
carbon replacement and regeneration costs. About five to ten percent of
the annual carbon requirement may need to be replaced to account for loss
of adsorption capacity, attrition, and handling losses. The rest of the
annual carbon requirement would incur regeneration costs which vary
somewhat depending upon whether on-site or off-site regeneration is chosen.
For an off-site carbon regeneration option a regeneration cost per unit
weight of carbon is provided by the user. On-site carbon regeneration
primarily involve operating cost of steam used for regeneration and the
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cost of cooling water used in the condenser. One Ib. of steam is assumed
to be needed to regenerate one Ib. of carbon; and one gallon of cooling
water is assumed to be needed for 3.43 Ibs. of steam used. The unit costs
of steam and cooling water are provided by the user.
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SECTION 4
NET AIR EMISSIONS ANALYSIS
The air stripping process transfers the volatile organic (chemical)
contaminants from the wastewater to air. The emission of the VOCs in the
air stream may be controlled by an air pollution control device such as a
carbon adsorber or a catalytic oxidizer. Although these processes are
capable of removing the volatile organic chemicals from the air stream
their operation requires energy, the generation of which may involve
secondary pollutant emissions.
In the catalytic oxidation the energy for VOC destruction is provided
by combustion of natural gas which heats the air stream and maintains the
temperature of the combustor at a desired level of about 700VF. The
carbon used in the carbon adsorption system is usually regenerated by
steam which in turn is produced in a boiler typically burning distillate
fuel oil. These combustion processes produce additional pollutants such
as S02 and NOX which must be taken into account in assessing the
effectiveness of the VOC air emission control processes.
The contaminants of concern from fuel combustion are carbon monoxide
(CO), sulfur dioxide (S02), nitrogen oxides (NOX), and carbon dioxide
(C02). The rate of emission of these contaminants will depend upon the
rate of fuel combustion or the energy input required during catalytic
oxidation or regeneration of carbon. Emission factors are available12 to
estimate emissions of various contaminants from natural gas and distillate
fuel oil as given in Table 3.
These values can be converted to lb/106 Btu basis through assumptions
concerning heating values. Assuming natural gas heating value of 1000
Btu/ft3 and fuel oil heating value of 139,000 Btu/gal the AP-42 emission
factors can be recalculated to a common (lb/106 Btu) basis. These values
are also displayed in Table 3.
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TABLE 3. EMISSION FACTORS FROM AP-42
FOR THE FUEL COMBUSTION PRODUCTS
Pollutant
S02
NOX
CO
VOC (nonmethane
VOC (methane)
* Where S = %
Natural
(lb/106 ft3)
0.6
100.0
20.0
) 5.3
2.7
sulfur in fuel
Gas
(lb/106 Btu)
6.00 x 10~4
0.100
0.020
5.3 X 10~3
2.7 x 10~3
oil.
Distil
(lb/103 gal
142 (S}*
20.0
5.0
0.34
0.216
late Oil
. ) (lb/106 Btu)
1.022 (SI*
0.144
0.036
0.002
0.002
The data for carbon dioxide is not included in AP-4210 but is an
important consideration from a global warming standpoint. The carbon
dioxide emission factors may be estimated from typical fuel analysis: For
natural gas - 116.36 Ib C02/106 BTU, and for distillate oil 163.65 Ib
C02/106 Btu.
4.1 Carbon Adsorption Process:
The emissions from the carbon adsorption may be assumed to result
primarily from the generation of steam used for carbon regeneration.
During regeneration almost all of the adsorbed VOCs are released along
with steam which are subsequently condensed in a condenser. The residual
emissions of uncondensed VOCs may be ignored. The condensed organics may
further be separated from the aqueous phase in a decanter. The recovered
organics are assumed to be recycled for reuse and the saturated aqueous
phase is assumed to be routed back to the wastewater stream for
restripping.
The amount of steam needed for carbon regeneration is proportional to
the amount of the carbon used. On the average 1 Ib. of steam may be
assumed to be required for every Ib of carbon. The amount of fuel oil
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neat required can be directly calculated from the amount of steam
required, heating value of steam, and boiler efficiency:
Qf - Mc * Qs/Eff (14)
where,
Qf = Fuel oil heat required, Btu/year
Mc = Amount of carbon used, Ib/year
Qs = Steam enthalpy, Btu/lb
Eff = Boiler efficiency
After determining the required fuel oil heat input, Qf, the emission of
pollutants can directly be calculated using appropriate emission factors
given ir, Table 3. For steam enthalpy of 1,000 Btu/lb, 75% boiler
efficiency, and 1* sulfur in fuel oil about 1.6 x 10~3 Ibs of emissions
may be generated (excluding C02) for every Ib. of carbon regenerated.
4.2 Catalytic Oxidation Process:
The emissions from the catalytic oxidation process primarily result
from the combustion of natural gas required to heat the air and to
maintain the combustor temperature, as well as from combustion of VOCs
themselves. The natural gas requirement can be calculated from the inlet
air flow and temperature, combustion temperature, and extent of heat
recovery. The amount of natural gas required may conservatively be
considered independent of the VOC concentration by ignoring the heat of
combustion of the VOCs. After calculating the natural gas requirements
Table 3 may be used to estimate the emissions of various pollutants.
The combustion of the VOCs themselves may lead to additional
pollutants, notably halogonated acid gases (HC1, HF, HBr and HI) and C02.
These emissions are directly related to the mass fraction of the halogens
and carbon in the VOCs respectively and the VOC mass emission rate. Using
appropriate halogen and carbon mass ratio with respect to the total mass
of the VOCs these emissions may be estimated. The ASPAIR model package
performs the detailed calculations to determine the net air emissions.
- 25 -
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SECTION 5
"ASPAIR" INTERACTIVE SOFTWARE
5.1 Overview:
Although ASPEN is a very powerful simulation tool, getting data into an
ASPEN input program and preparing it to run is often a tedious task. Data
must be typed manually in a fixed format, and great care is required in
preparing the input information. To make ASPEN easier to use, a "front-end"
program, "ASPAIR", has been developed specifically to make air stripping
process simulations. This software, developed for use on a personal computer.
allows a user to input all the process data interactively. It then reads a
general ASPEN input file (e.g.. template), modifies it according to
information supplied by the user, and then creates a new ASPEN input file
tailored to the problem at hand.
In this section, the procedure for creating an ASPEN input file and
running an ASPEN simulation is outlined. Figure 2 shows the suggested
sequence of steps. The user first enters information about the problem at
hand using the ASPAIR software, which converts the user's responses into an
ASPEN input file. A summary of the input data is also prepared by this
software as a text file which may be printed later. The ASPEN input file,
written to a personal computer disk, is then uploaded to a VAX mainframe and
executed. A report of the simulation results is generated as a VAX file, in
standard ASCII format, that can be downloaded to a personal computer and
printed. Each of these steps is described in the following paragraphs.
5.2 Interactive Front-End Program:
The "front-end" program is written in BASIC language and it allows a user
to input different types of data through a series of interactive screens
displayed on the monitor. The data input procedure is described in detail in
a later section. A marker/index system was created for entering all the
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Load Data Input
Software
Load Existing Dataset
Or
Create New Dataset
Input Site Data
Input Dataset
Created/Stored
Scan ASPEN Input File Template,
Insert Dataset Values To
Create Customized ASPEN Input File
Upload Customized ASPEN
Input File To VAX Computer
Execute ASPEN Program
Using Uploaded Input File
Download ASPEN Report
File
Print Downloaded Report File
Merge With Input Data Summary
Print Summary
Of Site Data
Figure 2
Run Procedure for ASPEN Air Stripper Model
28
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gathered informai-ion into the general air stripping template. In the
template, a Barker is placed wherever a piece of information nay change
according to the user's input. This marker is si*ply a character string;
ASCII code 168 (an inverted question mark) followed by an index number and
terminated by another ASCII code 168. When the front-end program reads the
template file and encounters the marker string, the appropriate piece of
information is inserted at the marker. The index number represents the
element of the vector (in the front-end program) where the user's responses
are stored, so the marker string describes the location of the data to be
inserted.
The customized ASPEN input file can then be uploaded to the VAX and
executed according to the ASPEN run procedure described later. With this
"expert system" approach, the ASPAIR air stripping model can be used without
any knowledge of ASPEN programming.
5.3 Installation and Start-up Procedures:
The front-end software is a BASIC computer program that can be run on an
IBM-compatible (MS-DOS) personal computer equipped with 640K of RAM (random
access memory). Color (RGB/CGA/EGA) and black-and-white (B/W) monitors are
supported in a single executable file named "ASPAIR.EXE". At startup, the
program asks the user which type of monitor is installed.
The front-end software has interactive menus and onscreen help and
instructions, making most operations self-explanatory. To run the program
from a floppy disk, the following steps should be performed:
1) Insert the program disk into the designated drive and change the
DOS drive prompt to the appropriate letter (e.'g., A>);
2) Type the command "ASPAIR" at the DOS drive prompt and press
[Return] to execute the program;
3) Select a dataset (or set of default values) according to the
onscreen start-up instructions;
- 29 -
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4) Follow instructions as they are displayed onscreen and supply
information as requested.
To operate the program from a hard disk instead of a floppy disk.
create a hard disk directory (at the "C>" prompt) with the DOS command
"«d c:\ASPEN". (This illustration assumes a directory name of "ASPEN"; any
other choice acceptable to DOS will also work.) Then place the original
program diskette into drive A and enter the following DOS command at the
"C>" prompt: "copy a:*.* c:\ASPEN". To run the program, enter the DOS
command "cd \ASPEN" at the "C>" prompt and type "ASPAIR". The program
should then run normally according to the above instructions for floppy
disk operation. When duplicating the original program diskette, copy the
contents of the entire diskette since the ASPAIR program uses all of the
files in the startup directory.
5.4 Entering Information:
The first screen displayed by the front-end program allows the user to
load an existing dataset or choose a set of default values for a sample
case. After loading these values, the Main Menu is displayed. Each menu
item flashes when it is selected with the up/down cursor keys. A
reproduction of the Main Menu is shown in Figure 3. Note that the
currently loaded dataset is displayed along with the chosen air emission
control option and the choice of rating/design mode. The user simply
selects the items of interest, in any order, from the Main Menu and enters
information about the problem at hand. The program always returns to the
Main Menu when data entry for a given item is complete. When all data has
been entered, the user can save his work and create an ASPEN input file at
the Main Menu with the "S" and "W" options, respectively.
When entering data with the front-end software, each input screen will
first be displayed with default values (in brackets to the right of the
screen) for the user to review. A highlighted question at the bottom of
the screen asks if any changes are necessary. If the current entries are
acceptable, no further action is needed and the [Return] key (or "[N]o")
displays the next screen. Changes in the displayed values are made by
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Interactive ASPEM Air Stripping Simulation
« WAIN SELECTION HENU »
Use cursor keys to change selection, CEnter] to accept
Current Data Set : C AIR.dat ]
escriptive information
nits conversion of input data
opponent selection / Properties
eed stream information
OC control option / Data, I Adsorption 3
ir stripper data, C Rating Hode ]
conomic parameters
oad another dataset or default values
ave current dataset values
rite modified input file to disk
<0> uit program - exit to DOS
Figure 3. Main menu for "ASPAIR" interactive program.
31
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entering M[Y]es" at the bottom of the screen and supplying data at the cursor
prompt. The cursor will begin at the first item, and pressing [Return]
without entering any data will choose the default value already loaded and
move the cursor to the next position. Any entry made by the user will replace
the displayed default value and advance the cursor. Pressing [Esc] at any
time (or finishing the data inputs) will return the user to the bottom of the
screen where there will again be an opportunity to review and/or change the
entered information.
Another type of information entry is by a menu with a movable cursor bar.
An example is the chemical selection option available on the Main Menu as item
"C". As shown in Figure 4, this item first displays the default chemical list
and provides the user with three options: (1) to delete one or more chemicals
from the default list; (2) to add more chemicals; and (3) to make no changes.
A toggle key, [Fl], alternately displays the component numbers above 10 and
below 10, respectively, if more than 10 components are loaded. Deletions are
updated immediately on the screen.
Selecting "Add chemicals" option causes a scrolling list of chemical names
to appear onscreen (see Figure 5), and the [T] and [U] keys can be used to
[T]ag and [U]ntag selected chemicals. In the event that a chemical of
interest is not present in the ASPEN library, it is recommended that a
surrogate chemical with similar structure and properties be selected from the
available list. When the chemical selection is complete, the user then has
the option of reviewing and modifying the Henry's law constants available for
the chosen compounds. In the case of a surrogate chemical, the user may use
the Henry's law constant for the original chemical if available. A list of
some commonly encountered volatile organic chemicals not included in ASPEN is
given in Table 4 with possible surrogate chemicals.
5.5 Creating a Custom ASPEN Input File:
Referring again to the Main Menu (see Figure 3), the "S" selection saves
the user's information entries in a named dataset file (with a ".dat"
extension) for future recall. It is recommended that this feature
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Interactive ASPEN Air Stripping Sinulation
« COMPONENTS / PROPERTIES »
Current List of Components Selected for Simulation
1 .
2 .
3 .
4 .
Tetrachloroethylene
Trichloroethylene
1, 1, 2-Trichloroethane
1, 1-Dichloroethane
C2CL4
C2HCL3
C2H3CL3
C2H4CL2-1
Components from ASPEN Data Library -
1 to 4
Do you »ant to make any change in this Compound List ?
< A « Add, D » Delete, and CHI = No )
Figure 4. "Component Selection/Properties" screen.
33
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ASPEN Chemicals: [Tlag or [UJntag
—=—====== m •
Trifluorobromomethane CBRF3
> Chlorotrifluoroaethane CCLF3
Dichlorodifluoromethane CCL2F2
Phosgene CCL20
> Trichlorofluoroaethane CCL3F
Carbon-Tetrachioride CCL4
Carbon-Tetrafluoride CF4
Carbon-Disulfide CS2
Chlorodifluoromethane CHCLF2
Dichloromonofluoro»ethane CHCL2F
Position cursor bar using cursor keys, hit IT] to tag a chemical
hit CUJ to untag a chemical, hit tEHTERJ to return chemical list.
[PgUp], (PgDn], (Home! and [End] are also active.
Figure 5. Chemical Selection menu.
-------
TABLE 4. POSSIBLE SURROGATES FOR SOME VOLATILE
ORGANIC CHEMICALS NOT INCLUDED IN ASPEN LIBRARY
Chemical
Possible Surrogate
1,1 Dichloroethylene
1,1 Dichloroethane
1,2 Dichloroethylene
1,2 Dichloroethane
1,1.1 Trichloroeihane
1.1,2 Trichloroethane
Methyl-tert-Butyl-Ether
Ethyl-Propyl-Ether
1,1,2,2 Tetrachloroethane
1,1,2 Trichloroethane
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be used frequently when creating a simulation to protect the work against
accident. As a precaution, the user is reminded by the front-end program
to save his work before leaving the program with the Main Menu "Q"
selection.
The "W" selection in the Main Menu will both save the current dataset
and create a custom, ready-to-run ASPEN input file (with a ".inp"
extension). A third file, with a ".prl" extension, is also created by
the "S" and "W" main menu commands.as a summary report of the data entered
by the user. The user supplies a name that is used for the dataset. input
file, and input data report (e.g., "example.dat". "example.Inp", and
"example.prl"). This naming convention is useful for determining which
dataset was used to create a particular input file and input data report.
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SECTION 6
USING ASPEN ON THE VAX
Use of the ASPEN air stripper model involves using a personal computer
(PC) as a computer terminal to connect to the EPA National Computer Center
(NCC) VAX Cluster, transferring computer files from the personal computer
to the VAX, and executing the ASPEN model through the computer terminal.
The procedures given below are to be followed to ensure proper execution of
the ASPEN program.
Questions relating to the use of the ASPEN program can be directed to
Mr. Robert Blaszczak, Control Technology Center, U.S. EPA at
(919) 541-5432. Assistance may also be obtained from Ms. Penny Lassiter,
U. S. EPA/OAQPS at (919) 541-5396 or Mr. James Durham, U. S. EPA/OAQPS at
(919) 541-5672. This user's guide has been written to provide enough
information for user to complete an ASPEN run. However, information
regarding the services provided by and operations of NCC are contained in
the publication titled Guide to NCC Services, published by U.S. EPA, Office
of Administration and Resources Management, National Data Processing
Division. A copy may be requested from user support services at the
telephone number listed below. The "VAX Cluster Ready Reference" section
in the guide provides essential information for users of NCC's VAX
computers. Basic descriptions of procedures, utilities, languages, and
software are included in the VAX online documentation. The NCC
comprehensive user support service may be reached at (FTS) 629-7862 or
(919)541-7862, or (800) 334-2405 for users outside North Carolina.
6.1 Setting Up a User Account:
Currently, the APSEN air stripper model is available on the VAX Cluster
located at NCC, Research Triangle Park, North Carolina. Each new user must
obtain a user ID and account code to gain access to the computer. Users
who already have these items and know how to use them at their own computer
terminals may proceed immediately to Subsection 6.2.
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Obtaining an account on the VAX computer at NCC requires submission of
a user registration form for approval by the EPA account manager or ADP
coordinator. This form, EPA Form N258. is used whether or not the new user
is an EPA employee. A sample Form N258 is included in Appendix D.
For EPA users, the form is signed and submitted by the Automatic Data
Processing (ADP) Coordinator of the user's EPA organization and sent to the
Time Sharing Services Management System (TSSMS) Office at the address shown
on the form. Non-EPA users must be in an organization that has established
an Inter-agency Agreement (IAG) with EPA. If the IAG is with a Regional
Organization (RO), the form is submitted to one of the 10 regional ADP
Coordinators as shown in Table 5.
If the central office of EPA is handling the IAG. Patrick Garvey, EPA
PM-211M, WSM, 401 M Street, S.W., Washington, D.C. 20460, at (202) 382-2405
or (FTS) 382-2405, should be contacted.
When the request for an account has been approved by TSSMS. the new
user will be sent a personal letter containing his or her account code.
user-ID, and initial password.
6.2 Accessing the VAX Using Personal Computers:
After receiving an account code, user-ID, and password from TSSMS. and
creating a custom ASPEN input file on a personal computer with the front-
end software as described in Subsection 2.5. the next step is to connect
the personal computer with the NCC VAX Cluster. The personal computer is
used as a terminal to upload the ASPEN input file and to run the ASPEN
program on the NCC VAX. The following procedures are used for personal
computers because they are capable of both generating the ASPEN input file
and serving as a computer terminal. In the following text, prompts from
the VAX system are enclosed by " ", and response to a prompt is enclosed
by < >, and specific keys to be pressed are enclosed by [ ]. It is not
necessary to type these symbols in the operations.
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TABLE 5. REGIONAL ADP COORDINATORS
Region
Name
Address
Telephone
I Michael T. MacDougall
Chief, Data Management
Section
II Mr. Robert A. Messin
Chief, Data System
Branc
III Mr. A. Joseph Hamilton
Chief, Info Systems
Branch
IV Mr. Richard W. Shekell
ADP Management Branch
V Mr. Stephen K. Goranson
Chief, Management
Services Branch
VI Mr. David R. White
Chief, Data Processing
Branch
VII Mr. Dale B. Parke
Chief, Programs Systems
Section
VIII Mr. Alfred R. Vigil
Chief, Info & Comp
Management Branch
IX Mr. Eldred G. Boze
Chief, Info Research
Management Branch
X Mr. James C. Peterson
Chief, Data Systems
Branch
John F. Kennedy Bldg.
Rm. 2211
Boston, MA 02203
26 Federal Plaza
Rm. 404
New York, NY 10278
841 Chestnut Street
Philadelphia, PA 19107
345 Courtland Street
Room-67
Atlanta, GA 30365
230 South Dearborn
(5-MI-ll)
Chicago, IL 60604
1445 Ross Avenue
Dallas, TX 75202
726 Minnesota Avenue
Kansas City. KS 66101
999 18th Street
Denver. CO 80202
FTS-835-3377
617-565-3377
FTS-264-9850
212-264-9850
FTS-597-8046
215-597-8046
FTS-257-2316
404-347-2316
FTS-353-2074
312-353-2074
FTS-255-6540
214-655-6540
FTS-276-7206
913-551-7206
FTS-330-1423
303-293-1423
215 Fremont Street
San Francisco, CA 94105 415-556-6536
1200 6th Avenue
Seattle. WA 98101
FTS-399-2977
206-442-2977
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Using a personal computer as a terminal, a user can dial-up the NCC VAX
Cluster by a modem through a telephone line. Since there is a wide variety
of communication packages and modems that can be used, users should refer
to their hardware and software documentation for specific instructions.
There are, however, some general guidelines that apply to all types of
communications with the VAX:
Connection can be made at either 1200 or 2400 baud.
Communication software should be set to emulate a VT-100 type
terminal.
Communication parameters should be 7 data bits, 1 stop bit. and
even parity (An example of communication parameters setting for
Crosstalk communication software is included in Appendix E).
Local users in Research Triangle Park, North Carolina can dial up the
Port Selector switch directly at (919) 541-4642 or (FTS) 629-4642 for 1200
baud, or at (919) 541-0700 or (FTS) 629-0700 for 2400 baud. When the
connection is made, press [Enter] once to display the Port Selection menu
as shown in Figure 6.
FIGURE 6. EXAMPLE OF THE PORT SELECTION MENU
Welcome to the Environmental Protection Agency National Computer Center
Please enter one of the following selections:
IBMPSI for IBM
TCP for IBM 3270 EMULATION
VAXA for VAX SYS A
VAXB for VAX SYS B
EMAIL for EMAIL
Enter selection:
- 40 -
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At this point, type either or and press [Enter] to
connect to the VAX. The typed characters will not be shown on the screen.
After making a selection, a "Connected." message should appear. Press
[Enter] again to initiate the logon procedure as described in Subsection
6.3.1.
Users outside the Research Triangle Park. North Carolina, may reach the
Port Selector menu through the TYMNET communication network. When
connecting to TYMNET, type in response to the prompt "Please type your
terminal identifier:", then on the next screen type for 1200 baud
connection, or for 2400 baud. After a short message, the Port
Selector menu will appear and the selection can be made as described above
for dial-up, Port Selection switch users.
Users located in the Washington, DC area, can access the VAX Cluster
through the Washington Information Center's (WIC) Data Switch at (202)488-
3671. A different selection menu appears on the screen with this
connection. Type and press [Enter] at the prompt "YOUR SELECTION?>"
to complete connection with the NCC VAX. Users in the Washington, DC area
should contact the WIC Telecommunication Group at (202) 382-HELP for
assistance if there are any questions or problems in completing the
connection.
6.3 Running the ASPEN Program on the VAX:
Once the connection between the personal computer and the NCC VAX
Cluster has been established, the following procedures are followed for
running the ASPEN program.
6.3.1 Logging in to the NCC VAX Cluster Computer:
After the VAX responds with a prompt "Connected." for the connection,
1. Press [Enter] to get to the Username/Password prompts.
- 41 -
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2. Enter the appropriate username and password at these prompts. An
on-screen bulletin will show the status of your previous
connections and any current news alerts. An example of this on-
screen bulletin is shown below in Figure 7.
3. Type and press [Enter] in response to the "Project:"
prompt following the on-screen bulletin as shown in Figure 7.
4. A "$" prompt will appear indicating the connection to the NCC VAX
has been successfully completed.
6.3.2 Transferring Piles Proa a Personal Computer to the VAX:
Before using the ASPEN software, it is necessary to upload the ASPEN
input file, XXXX.INP, created with the front-end program described in
Subsection 5.5, to the VAX. First time users also need to upload a
LOGIN.COM file which is supplied along with the front-end software. File
transfers are accomplished using the Kermit file transfer protocol on the
VAX and the PC. The following steps would be used for a personal computer
using Crosstalk communication software.
1. At the "$" prompt, type [Enter] and wait, for a "Kermit-32>"
prompt to appear.
2. At the "Kermit-32>" prompt, type [Enter]. (XXXX is
the file name and YYY is its extension you give to the file you are
going to transfer from the personal computer and store on the VAX.) At
this point, the VAX will pause and wait for the file transfer to be
initiated from the user's personal computer.
3. Press [Home] to display Crosstalk's command line at the bottom of the
screen (e.g.. "Command?") and type [Enter] to
start the file transmission. (DISKDRIVE may be any disk drive or a
directory on a hard disk drive, XXXX.YYY is the name of the ASPEN input
file with the extension .INP or LOGIN.COM file.)
- 42 -
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FIGURE 7. EXAMPLE OF LOGIN SCREEN AND ON-SCREEN BULLETIN ON NCC VAX
Enter selection:
Connected.
Username:
Password:
VAX User Support: (FTS) 629-7862 or 919-541-7862 or 800-334-2405
VAXCluster OPERATIONS STATUS PHONE: FTS 629-2969 or 919-541-2969
For the current Operations schedule type: OPERATION_SCHEDULE
Last interactive login on Wednesday, 16-May-1990 08:56
Last non-interactive login on Wednesday, 16-May-1990 00:10
Last Boot time was 14-May-1990 06:26:36.45
CURRENT NEWS ALERTS
05/14/90: TAPE IS NOT ANSI FORMAT ERRORS - SEE NEWS ALERT2
04/17/90: MEMORIAL DAY ELECTRICAL OUTAGE - SEE NEWS ALERTS
TYPE "NEWS ALERT*" TO VIEW AN ALERT
Project: ASPEN001
Paced, error-checked transmission of the ASPEN input file or LOGIN.COM
file then begins. When the transfer is complete the message "file
transmission complete" will appear on the screen for Crosstalk. Other
communication software will display messages such as "more to come
. press ENTER" or supply a sound signal prompt to indicate the file
transfer is complete.
- 43 -
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During file transfer an error indication may appear on the screen.
Most communication software will retransmit the portion of the file in
which the error occurred, therefore correcting the error automatically.
If too many errors occur (number varies according to software
specification) the transfer will terminate in an error condition. In
this case go to step 5 and repeat step 2 through 4 for the same file.
5. Press [Enter], then [Home], then [Enter] to obtain the "Kermit-32>"
prompt.
6. If more than one file is being transferred, repeat steps 2 through 5
for each file.
7. When all files are transferred, type to return to the "$" prompt
on the VAX.
6.3.3 Copying Library Files to User Account for First Ti»e Users:
New users using ASPEN for the first time should copy two library files
from another directory on the VAX before making any run on the ASPEN
program. These files can be copied as follows:
1. At the "$" prompt, type
[Enter], then wait for the "$" prompt.
2. At the "$" prompt, type
[Enter], then wait for the "$" prompt.
6.3.4 Running the ASPEN Air Stripper Program on the VAX:
First time users, should have 4 files on the VAX under their directory.
These are: USERLIB.OLB, USERLIB.OPT, LOGIN.COM, and the ASPEN input file
XXXX.INP. (XXXX is the file name assigned to the file with the specific
extension ".INP" for the input file.) When the LOGIN.COM file is initially
- 44 -
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uploaded from the PC. the file should b^ executed once using the command in
step 1 below. Otherwise, proceed to step 2.
1. At the "$" prompt, type <@LOGIN.COM> [Enter] to execute the login
command file one time, then wait for the "$" prompt.
2. At the "$" prompt, type [Enter] to check if all the
necessary files are present. If not, return to Subsections 6.3.2
or 6.3.3 and follow the procedures to upload or copy the needed
files.
3. At the "$" prompt, type [Enter] and respond to the prompt
"Please enter input file name (? for help)" with
[Enter], or type [Enter] directly to initiate the
ASPEN program.
4, At this point, a screen prompt asks whether the input file contains
inserts or user libraries. Respond with [Enter].
5. At the "$" prompt, the VAX will respond with the message "Job XXXX
(queue aaaa, entry nnn) started on bbbb_bbb", then followed by
another "$" prompt.
6. When the run is completed, the VAX displays a message "Job XXXX
(queue bbbb_bbb, entry nnn) completed" at the "$" prompt. This
will be followed by another "$" prompt.
7. Type [Enter] to check if the result files for a
successful run are generated. These should include: ZZZZ.HIS,
ZZZZ.LOG, ZZZZ.PRM, and ZZZZ.REP files. In this case ZZZZ is the
RNID specified in the input file (see Section 7.1).
8. If the result files are not generated, type
-------
might have been issued by the ASPEN software or VAX system
software. You may press [Ctrl]+[S] simultaneously to pause the
display, [Ctrl]-»-[Q] to resume scrolling, or press [Ctrl]-*-[C] or
[Ctrl]+[Y] to exit from scrolling.
6.3.5 Transferring Output Files fro« the ERA-VAX to a Personal Computer:
The result files generated by the ASPEN program can be downloaded from
the VAX to a personal computer if desired. The procedures for downloading
are identical to those in Subsection 6.3.2 for uploading, except steps 2
and 3 are replaced by the following two steps.
2. At the "Kermit-32>" prompt, type [Enter]. (XXXX is
the file name and YYY is its extension that you are going to
download from the VAX.)
3. Press [Home] to display Crosstalk's command line at the bottom of
the screen (e.g., "Command?") and type
[Enter] to start the file transmission.
Downloading XXXX.PR2 file will take about 1 minute at 1200 baud.
6.3.6 Logging Out Procedures:
1. At the "$" prompt, type [Enter] to disconnect your
personal computer from the VAX. The screen will show "NO CARRIER"
after a short message.
2. Press [Home] to display Crosstalk's command line at the bottom of
the screen (e.g., "Command?") and type to exit from
Crosstalk.
At this stage, you have completed the operation of running ASPEN on the
VAX through a personal computer. Word processing software or a text editor
can be used on a personal computer to view or print the downloaded ASPEN
output files.
- 46 -
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SECTION 7
GENERATION OF SIMULATION REPORT
After carrying out the performance and design calculations to size the
air stripper and the air emission control units, the ASPAIR model
determines the capital and annualized costs for both the air stripper and
the chosen air emission control device. An analysis is then conducted to
determine the net air emissions taking into account the secondary emissions
generated by operating the air emission control devices. A simulation
report is then prepared to summarize the performance calculations, .cost
estimates, and net air emissions anticipated.
7.1 Report Output Generation:
Prior to creation of a custom ASPEN input file, the front-end program
asks the user for a 4-character run identification string (referred to in
this discussion as RNID). The ASPEN system uses this run ID to create
files in the VAX disk directory where the simulation is executed. Several
of these files are worth noting because they contain error messages,
intermediate calculations, or simulation results. A severe error in input
file syntax or format (causing early termination of the run) will be
highlighted in a file called "RNID.HIT". Errors and warnings during
execution of the ASPEN program, as well as intermediate calculations, can
be found in a file named "RNID.HIS" (called the ASPEN History File). The
final report for the simulation is named "RNID.REP" (called the ASPEN
Report File).
NOTE: Because ASPEN creates a large number of output files
(particularly for runs that abort prematurely), an ASPEN utility
program called "GETRIDOF" is available on the VAX to erase
unwanted simulation results. For example, the command "GETRIDOF
TST1" would delete all VAX files beginning with the run ID
"TST1". To avoid accidental file erasures, NEVER give the
custom ASPEN input file (or any other file you want to keep!) a
name that begins with the run ID.
- 47 -
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Since an ASPEN sinulation generates a RNID.REP (ASPEN report) file
which contains extensive output information in a general format not usually
needed by a user, a customized report format was specifically prepared to
present air stripper simulation results. With this format, a typical
report from an air stripper simulation run consists of three parts:
background material, a summary of input data prepared by the front-end
"ASPAIR" program from the user's inputs, and a performance and cost
analysis generated during the ASPEN simulation run. The background
material consists of a process schematic and a general narrative
description of the ASPAIR model. Copies of these are kept on file for each
of the possible process configurations.
The second and third sections of the report are stored in files with
the same base name as the parent dataset/input file and extensions of "PR1"
and "PR2" , respectively. The input data summary, "name.prl", is created by
the front-end program on a personal computer (with either the "S" or "W"
main menu options) and can be routed to a printer with any of several DOS
commands (for example, "copy name.prl Iptl:", where Iptl: is a line printer
connected to parallel port 1). This is done after exiting the front-end
program to generate a "hard copy" of the data that has been entered. An
ASPEN results summary, "name.pr2", is created as a VAX file during the
course of the simulation run and can be downloaded to a personal computer
(for printing) according to the procedures outlined earlier.
Put together, these three parts provide a complete report of the
simulation results, including background information and a schematic of the
process being modeled. As an example, Appendix B contains a case report
created for an air stripper equipped with a vapor-phase carbon adsorber for
control of air emissions. Finally, the History and Report Files on the VAX
can be downloaded and/or printed, if necessary, to provide supporting
calculations suitable for technical reference.
- 48 -
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SECTION 8
CASE STUDIES AND GRAPHICAL PROCEDURES
8.1 Introduction:
Conducting an ASPEN air stripper simulation requires the availability
of the ASPEN process simulator. Also, there may sometimes be a need for
conducting quick approximate performance and cost calculations for a
preliminary assessment. A number of simulations were therefore carried out
with the ASPAIR model package to highlight the effect of important
parameters on the performance and cost of the air stripper and control
units, and to develop simple graphical procedures to allow quick "short-
cut" estimates. In order to isolate the effect of a certain parameter,
other variables were held constant during such simulations. These
simulation results show the trends that may be expected in a given case and
general applicability of the ASPAIR model package. Graphs were developed
for performance/design and selected cost calculations as described in the
following sections.
8.2 Air Stripper Performance and Design Calculations:
As seen from the Equation (5), the parameters affecting the removal
efficiency of a VOC are the packing height, stripping factor R, overall
liquid phase mass transfer coefficient, and the liquid loading. The liquid
loading can be adjusted independently by designing the column diameter for
a desired pressure drop. The liquid phase overall mass transfer
coefficient strongly depends upon the liquid loading. The stripping factor
directly depends upon the operating G/L ratio and the Henry's Law constant
of the VOC. Equation (5) also indicates that the VOC removal efficiency is
relatively independent of the VOC concentration in the wastewater. This
equation may be used to design a column for a desired VOC removal
efficiency or to predict performance of an existing stripper. To
illustrate the effect of G/L ratio and the Henry's Law constant on the VOC
removal efficiency, several simulations were carried out for a waste flow
rate of 1000 gpm being stripped in a 1.8 m diameter column with 10 m
- 49 -
-------
packing height. The air and water temperatures were assumed to be 55°F as
being the annual average temperature of groundwater. The column was
assumed to be randomly packed with 1" polypropylene saddles. All the
physical properties of the VOC were assumed to be those of
trichloroethylene, except for the Henry's Law constant which was varied to
illustrate its effect.
The results are shown in Figures 8 and 9 for low and high efficiency
ranges. As seen clearly from these figures the Henry's law constant as
well as the G/L ratio have a dominant effect on the VOC removal. A high
G/L ratio is required for VOCs with low Henry's law constant values to
achieve similar degree of VOC removal (See also Table 1). Although Figures
8 and 9 were generated using a 10 m packing height, the plots may also be
used to determine approximate packing height for a desired removal
efficiency using the number of transfer units concept. In this concept the
ratio Z/Log (l-E/100) is approximately constant, with Z being packing
height and E being percent removal efficiency. Thus, if the 10 m height is
found to indicate 90% VOC removal efficiency at a certain G/L ratio for a
VOC of a certain Henry's Law constant, approximately 99* removal may be
expected with a packing height of 20 m using the same G/L ratio (provided
the G/L ratio is greater than the minimum required for 99% removal
efficiency) and about 68% removal may be expected with a 5 m column packing
height.
The operating G/L ratio and the Henry's law constant of a VOC are
combined in a single parameter "stripping factor" as defined in Equation 5.
The simulations described above also indicated that, for a given stripping
factor, the ratio L/KLa is relatively independent of the Henry's Law
constant as seen from Table 6. This fact allows approximate prediction of
the packing height as a function of the stripping factor and the desired
VOC removal efficiency. Such a correlation is shown in Figure 10. For a
VOC of a known Henry's Law constant the required packing height can be
directly determined for a desired removal efficiency and a chosen G/L ratio
(stripping factor).
- 50 -
-------
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Figure 9. Stripper efficiency vs. Henry's Law constant,
parameter = G/L (vol./vol.), high efficiency range.
-1
-------
TABLE 6. MASS TRANSFER COEFFICIENT AS A FUNCTION OP HENRY'S LAW CONSTANT.
Stripping Factor (R) = 2.0. T = 12.8°C. (55 -F).
Liquid Plow Rate - 300 gp».
Physical Properties Those of Trichloroethylene.
Ul
II @ 25°C G/L
aim m3/gmole v/v
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Stripping Factor
Flaure 10. Tower height as a function of stripping factor,
parameter = VOC removal efficiency.
-------
8.3 Capital and Annual!zed Costs of Air Stripper:
The aajor items in an air stripper system are the stripper vessel with
packing and other internals, liquid circulating pump, gas blower and associated
ductwork. Storage tanks as well as a liquid phase wastewater polishing
(carbon) bed may be present in some of the systems. For the development of
general graphical procedures storage tanks and polishing carbon bed units were
excluded in the cost calculations. The costs of an air stripper system
primarily depend upon the waste flow rate, Henry's law constant, and the
desired VOC removal efficiency. The Henry's Law constant value dictates the
minimum G/L ratio that must be used to achieve a desired removal efficiency.
An optimum G/L ratio greater than the minimum may be selected from the economic
considerations. Increasing the G/L ratio reduces the height of the packing
required to achieve the desired removal efficiency, however, at the same time
it also increases the diameter of the column to accommodate higher gas flow
rates, as well as the size and cost of the downstream system used to control
air emissions.
Figures 11 and 12 show the capital and annualized costs as a function of
wastewater flow rate and Henry's law constant for a desired VOC removal
efficiency of 90%. Figures 13 and 14 indicate similar cost correlation for a
desired VOC removal removal efficiency of 99%. In order to isolate the effect
of Henry's law constant on the stripper costs, other physical properties of a
VOC were assumed to be those of trichloroethylene, a commonly encountered VOC
in groundwater cleanup operations. The figures also indicate the G/L ratio
chosen in the stripper design for different Henry's Law constant values. The
waste flow rate determines the diameter of the column necessary to obtain a
desired pressure drop e.g. 0.5" of water/ft (0.41 kPa/m) of packing as used in
present simulations. The costs indicated are in 1989 dollars.
At low waste flow rates direct labor costs constitute a large proportion of
the annualized costs. At high waste flow rates and low H values the
electricity requirement for increased column pressure drop and the capital
investment finance charges dominate the annualized costs. The capital
investment costs for storage tanks, if present, may be estimated using Equation
(9) given in Section 3.4.
- 55 -
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2x105
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H = 3x103
H = 1x103
G/L=10)
G/L = 25)
G/L = 70)
G/L = 200)
G/L =500
10
20 32 50 100
Waste Flow (m3/hr)
200 320 500
Figure 11. Air stripper - capital Investment, VOC removal
efficiency = 90% (1989 dollars).
-------
10
20 32 50 100
Waste Flow (m3/hr)
200 320 500
Figure 12. Air stripper - annuallzed costs, VOC removal
efficiency = 90% (1989 dollars)
-------
Total Capital Investment ($)
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G/L = 25)
G/L = 70)
G/L = 200)
G/L = 500)
100
Waste Flow (m3/hr)
200 320 500
Figure 14. Air stripper - annuallzed costs, VOC removal
efficiency = 99%, parameter = Henry's Law constant,
atm-m3/gmole (1989 dollars).
-------
8.4 Capital and Annual!zed Costs of a Catalytic Oxidation Unit:
The capital investment and total annualized costs of a catalytic oxidation
unit directly depend upon the total gas flow rate. The fuel requirement and
the catalyst replacement form a large fraction of the annualized costs. For a
conservative cost estimate the fuel gas requirement may be determined by
ignoring any available heat of combustion of the VOCs themselves. This assures
a proper operation of the oxidizer regardless of the fluctuations in the
process VOC streams. The waste flow rate and the G/L ratio used in the
stripper determine the gas flow rate through the oxidizer. The G/L ratio, of
course, depends upon the Henry's Law constant of the VOC removed and the VOC
removal efficiency in the stripper. Figures 15 and 16 provide the capital and
annualized costs of a catalytic oxidizer unit as a function of the waste flow
and G/L ratio. Following parameters were used in estimating the capital and
annualized costs: cost of catalyst = 650 $/ft3 (22,955 $/m3); cost of natural
gas = 0.005 $/ft3 (0.177 $/m3); catalyst life = 2 year; heat recovery in the
oxidizer = 50*; operating hours = 8760 hrs/yr (365 days/yr); and gas space
velocity in catalyst bed = 20000 hr'1. The costs indicated are in 1989
dollars.
8.5 Capital and Annualized Costs of a Carbon Adsorber Unit:
Unlike a catalytic oxidation unit, the costs of a carbon adsorber strongly
depend upon the specific VOCs in the air emissions, because of the differences
in the adsorption capacities of activated carbon for various VOCs. The
adsorption capacity of an activated carbon for a VOC depends upon the
saturation ratio of the VOC as well as other physical properties such as
polarizability. The adsorption capacity thus depends upon the VOC
concentration in the gas phase and may not be strongly related to the Henry's
law constant.
Amount of carbon required to adsorb a given VOC in an adsorption cycle
depends upon the adsorption capacity of carbon for that VOC and the VOC mass
emission rate over the cycle period. In an air stripper operation the mass
emission rate of a VOC is roughly the product of the wastewater feed rate to
the stripper and the VOC concentration in the feed stream.
- 60 -
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19
Total Capital Investment ($)
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Figure 16. Catalytic oxidlzer - annuallzed costs,
parameter - G/L ratio (vol./vol.) (1989 dollars).
-------
The capital and annualized costs of a carbon adsorber system also depend
upon the mode of carbon regeneration. As discussed in sections 3.6 and 3.7.
the capital costs for an on-site regeneration system would be greater than
those for an off-site regeneration system. On the other hand, the annualized
costs for an off-site regeneration system would be greater than the on-site
regeneration annualized costs. Figures 17 and 18 present the capital and
annualized costs of a carbon adsorber system with on-site regeneration, as a
function of the VOC mass emission rate for four (4) commonly encountered VOCs.
Figures 19 and 20 provide corresponding correlations for an off-site carbon
regeneration mode. For a given case, the VOC loading is obtained by
multiplying waste flow rate with mass concentration. Since the adsorption
capacity of carbon strongly depends upon the VOC concentration in air. the
representation of carbon adsorber costs as a function of VOC loading is true
only approximately.
A G/L ratio of 20 was assumed to determine the gas flow rate through the
adsorber in these case studies. These simulations covered waste water flow
rates into the air stripper in the range of 100 to 1000 gpm (2.27 - 22.7 m3/hr)
and VOC concentrations in the water in the range of 0.1 to 10 ppm. following
parameters were used in estimating annualized costs: off site carbon
regeneration cost = $ 0.8/lb ($ 1.76/Kg); carbon replacement cost = $ 2/lb (S
4.41/Kg); carbon life = 5 years (i.e., 20% replacement each year); steam cost -
S6/MM BTU; operating hours = 8760 hrs/yr (365 days/yr); and gas velocity in
carbon bed = 1 ft/sec (0.3 m/sec).
As indicated by these figures, the carbon adsorber costs are high for VOCs
like vinyl chloride which are easy to strip but are also difficult to adsorb.
Since the carbon capacities are -VOC specific, generalized correlations can not
be established similar to the catalytic oxidizer unit. Table 7 indicates the
adsorption capacities of activated carbon for some of the common VOCs for the
three different wastewater concentrations used in the simulations. For lower
wastewater VOC concentrations, the VOC concentrations in the air emissions are
correspondingly lower resulting in lower equilibrium adsorption capacities.
- 63 -
-------
Total Capital Investment ($)
o
CD
a
o
3
>
cr
(A
O
6
CO
•o.
vS
s.
3
(D
(A
O
i
(A
to*
(Q
(D
O
3
(O
00
ttlVJIIV«0
rometha
CD
\
**
5'
•
•s
/
r
i_
v
\
-------
01
2x105
§1.4x105
O
Q>
N
fa
c
c
"co
1x105
7x104
5x104
Vinyl Chloride
Dichloromethane
Benzene
Tetrachloroethylene
/
/
r i
/ /
10 20 50 100 200 500 1000
VOC Loading in Waste (m3/hr- PPM) (~ g/hr)
2500
Fig. 18 Carbon Absorber-Total Annualized Cost On-slght Regeneration
-------
99
(Q
t
.*
10
O
-*
cr
o
3
cr
V)
O
o
tt
•o
Total Capital Investment ($)
3
<
x
^
O
ro
I 8
fi) r^
~ o
8.
(O ro
=• o
s S
N
"0 ro
"0 o
2 o
s: CD o
® ° o
=> s xx
(D
3
\
-------
5x106
~ 2x106
t
1X106
V)
O
o
T3
o
"«
c
5x105
2x10
jO 1x105
5x104
3.2x104
1
Vinyl Chloride
Dichloromethane
Benzene
Tetrachloroethylene
/
5 10 20 50 100 200 500 10002500
VOC Loading in Waste (m3/hr- PPM) (- g/hr)
Fig. 20 Carbon Absorber-Total Annualized Cost Off-sight Regeneration
-------
TABLE 7. EQUILIBRIUM CARBON ADSORPTION CAPACITIES FOR VARIOUS VOCs.
G/L = 20, STRIPPER VOC REMOVAL EFFICIENCY = 99%,
TEMPERATURE - 12.8»C
Adsorption Capacity, (g VOC/ g carbon) x 100
VOC Wastewater Concentration
0.1 ppm 1.0 ppm 10.0 ppm
Tetrachloroethylene
Trichloroethylene
Benzene
Chloroform
Methyl-Ethyl-Ketone
Dichloromethane
Vinyl Chloride
30,
15.
10,
7,
4.
1.
0,
.90
,14
. 11
.27
88
.33
.97
45
24
16
13
9
1
0
.20
.78
.58
.68
.47
.46
.97
59
39
25
25
17
5
2
.70
.00
.10
.10
.26
.28
.63
The economics of on-site vs off-site carbon regeneration depends upon the
specific VOC in question. For high loadings of a difficult to adsorb VOC like
vinyl chloride on-site regeneration provides a decided cost advantage. On the
other hand, for low loadings of an easy to adsorb VOC like tetrachlorethyiene
off-site regeneration may prove to be simple as well as cost effective.
In any given application, a number of VOCs may be present in the wastewater
stream. The total carbon requirement must therefore be based upon the
summation of individual VOC carbon requirements. The correlations shown in
Figures 17 through 20 were obtained by assuming only one VOC in waste, and may
not thus be directly applicable to a mixed VOC system unless most of the VOCs
in the feed stream have similar adsorption capacities.
- 68 -
-------
SECTION 9
SUMMARY
This document describes the general procedures for designing and costing
an air stripper and units to control resulting air emissions. A computer
model package 'ASPAIR' was developed to carry out simulations of the air
stripping process using ASPEN process simulator. ASPEN user models were
developed for the air stripping process as well as for the carbon adsorption
process to control air emissions. An interactive PC-based software "ASPAIR"
was developed to allow a user to create and run an ASPEN air stripping
simulation without any knowledge of ASPEN programming. This document
describes the procedures involved in using the ASPAIR model package.
The applicability of the ASPAIR model package was demonstrated through
several case studies which highlighted effect of important parameters such
as, Henry's Law constant, gas to liquid ratio. VOC removal efficiency and
wastewater throughput. The results of these case studies are presented in a
graphical form so as to allow quick 'short-cut' estimates of the performance
and cost of an air stripper and associated air emissions control units.
Henry's Law constant strongly affects performance and design of an air
stripper. It dictates the G/L ratio that needs to be used to obtain a
desired performance. The capital and annualized costs of an air stripper
thus depend upon the wastewater throughput rate as well as the Henry's Law
constant and the desired performance. The capital and annualized costs of a
catalytic oxidizer depend upon the gas flow rate which in turn depends upon
the waste throughput of the stripper and the operating G/L ratio used. The
annualized costs of a carbon adsorber unit are strongly related to the
adsorption potential of a VOC and its mass emission rate. The capital and
annualized costs of a carbon adsorber system also depend upon the mode of
carbon regeneration. The relative economics of on-site vs off-site
regeneration depends upon the emission rate of VOCs and is also specific to
VOC components.
- 69 -
-------
SECTION 10
REFERENCES
1. ASPEN User Manual. U.S. Dept. of Energy Report No. DOE/MC/16481-1203.
Vol.1. 1982, p iii.
2. Perry, R. H. and Chilton. C. H., Chemical Engineers' Handbook, Fifth
Edition, New York: McGraw-Hill Book Company. 1973.
3. Onda. K., E. Sada and Y. Murase, "Liquid Side Mass Transfer
Coefficients in Packed Towers", AIChE Journal, 5, 235-9, 1959.
4. Henley, E. J. and J. D. Seader. Equilibrium-Stage Operations in
Chemical Engineering, New York: John Wiley & Sons, 1981, p. 55.
5. QAQPS/SDB Control Cost Manual (4th Edition), EPA 450/3-90-006. U. S.
EPA Office of Air Quality Planning and Standards, Standards
Development Branch, Research Triangle Park. NC, January 1990, Chapters
3 and 4.
6. Polanyi. M.. Verh. Dtsch. Pnvs. Ges.. 16. 1012 (1914).
7. G.B. Howe, M.E. Mull ins, and T.N. Rogers, Evaluation and Prediction of
Henry's Law Constants and Aqueous Solubilities for Solvents and
Hydrocarbon Fuel Components. Vol. II: Experimental Henry's Law Data.
ESL-TR-86-66, Vol. II, Engineering and Services Laboratory. Air Force
Eng. and Services Center, Tyndall Air Force Base. Florida, 1987.
8. Personal Communication by Tony Rogers with Pete Rogers of Groundwater
Technology. 24168 Haggerty Rd, Farmington Hills, MI 48024, (Phone:
(313) 473-0720). February 16. 1990.
9. Personal Communication by Ashok Damle with Joseph Hill of Koch
Engineering. (Phone: (212) 682-5755). February 20. 1990.
10 R.S. Hall, W. M. Vatavuk, and J. Matley, "Estimating Process Equipment
Costs," Chemical Engineering. 95(17): 66 (1988).
11. Corripio, A. B.. K. S. Ghrien. L. B. Evans. Chem. Eng.. Jan. 25. 1982.
p. 125.
12. "Compilation of Air Pollution Emission Factors", Third Edition, U.S.
EPA/AP-42, Supplement No. 13, August. 1982.
- 71 -
-------
- 72 -
-------
APPENDIX A
HENRY'S LAW CONSTANTS AND REFRACTIVE
INDICES FOR SELECTED ORGANIC CHEMICALS
-------
HENRY'S LAW CONSTANTS AND REFRACTIVE INDICES FOR CHEMICALS IN ASPEN LIBRARY
Component Name Formula
Henry's Law
Constant
Atm-m3/gmole
Trifluorobromomethane" CBRF3
Chlorotrifluoromethane CCLF3
Dichlorodifluoromethane CCL2F2
Phosgene CCL20
Trichlorofluoromethane CCL3F
Carbon-Tetrachloride CCL4
Carbon-Tetrafluoride CF4
Carbon-Disulfide C£2
Chlorodifluoromethane CHCLF2
Dichloromonofluoromethan CHCL2F
Chloroform CHCL3
Hydrogen-Cyanide CHN
Dibromomethane* CH2BR2
Dichloromethane CH2CL2
Formaldehyde CH20
Formic-Acid CH202
Methyl-Bromide CH3BR
Methyl-Chloride CH3CL
Methyl-Fluoride CH3F
Methyl-Iodide CH3I
Methane CH4
Methanol CH40
Methyl-Mercaptan CH4S
Methyl-Amine CH5N
Methyl-Hydrazine- CH6N2
Chloropentafluoroethane" C2CLF5
1,l-Dachloro-1,2, 2,2-Te* C2CL2F4-1
1,2-Dichloro-l, 1,2, 2-Tet C2CL2F4-2
1.2. 2-Trichloro-l,1,2-Tr C2CL3F3
Tetrachloroethylene C2CL4
1, 1,2,2-Tetrachloro-l,2- C2CL4F2
Perfluoroethene C2F4
Perfluoroethane C2F6
Cyanogen C2N2
Trichloroethylene C2HCL3
Acetylene C2H2
1, 1-Dichloroethylene- C2H2CL2
cis 1,2-Dichloroethyien- C2H2CL2
trans 1,2-dichloroethyl* C2H2CL2
1, 1-Difluoroethylene C2H2F2
Vinyl-Chloride C2H3CL
3.
5.
7.
1.00E-01
1.00E-01
4.01E-01
1.71E-01
5.83E-02
3.00E-02
1.00E-01
1.68E-02
1.00E-01
9.21E*02
3.39E-03
4.65E-07
9.98E-04
19E-03
76E-05
00E-07
2. 21E-01
8.14E-03
1.00E-02
2.53E-03
1.34E»00
2.70E-06
4.18E-03
5.38E-03
3.44E-06
2.45E-01
2.45E-01
2.45E-01
2.45E-01
2.90E-02
2.45E-01
1.00E-02
1.00E-02
4.96E-03
9. 10E-03
26E-03
59E-02
55E-03
1.
2.
4.
9.46E-03
1.00E-02
8.60E-02
.og(H)
1.00
1.00
0.40
0.77
1.23
1.52
1.00
1.77
1.00
2.96
2.47
6.33
3.00
2.50
4.24
6.15
0.66
2.09
2.00
2.60
0. 13
5.57
2.38
2.27
5.46
0.61
0.61
0.61
0.61
1.54
•0.61
•2.00
•2.00
•2.30
2.04
2.90
1.59
2.34
2.02
2.00
1.07
Refract.
Index
1.5200
1.3876
1.3876
1.3876
1.3876
1.4630
1.3876
1.6276
1.4909
1.3724
1.4457
1.2675
1.5420
1.3348
1.3876
1.3714
1.4218
1.3389
1.1727
1.5293
1.3876
1.3288
1.3876
1.3876
1.3876
1.3876
1.3092
1.3876
1.3876
1.5053
1.4130
1.3876
1.3876
1.3876
1.4777
1.3460
1.4249
1.4490
1.4454
1.3876
1.3700
CAS No.
75-63-8
75-72-9
75-71-8
75-44-5
75-69-4
56-23-5
75-73-0
75-15-0
75-45-6
75-43-4
865-49-6
74-90-8
74-95-3
75-09-2
50-00-0
64-18-6
74-83-9
74-87-3
74-88-4
74-82-8
67-56-1
74-93-1
74-89-5
60-34-4
76-15-3
1320-37-2
76-14-2
76-13-1
127-18-4
76-11-9
116-14-3
76-16-4
460-19-5
79-01-6
74-86-2
75-35-4
156-59-2
156-60-5
75-38-7
75-01-4
» Component not in ASPEN library: The Henry's law constant may be used
for an appropriate surrogate
• Specific heat properties are missing in ASPEN database: Simulation may not
run with catalytic oxidation as an emissions control option
Al
-------
Henry's Lav
Component Name
r
1.1,2, 2-Tetrachloroetha*
«• f * 9 ^ f
1-Chloro-l, 1-Difluoroef
1, 1, 1-Trichloroethane*
1, 1, 2-Trichloroethane
1, 1, 1-Trif luoroethane
Acetonitrile
Ethylene
1, l-Dichloroethane
1, 2-Dichloroethane
1, 1-Difluoroethane
Acetaldehyde
Ethylene-Oxide
Acetic-Acid
Methyl-Formate
Ethyl-Bromide
Ethyl-Chloride
Ethyl-Fluoride
Ethylene-Imine
^ L ^ .. • f %
Ethane
Dimethyl-Ether
C+ hand 1
C, L no Ji u ^
Ethylene-Glycol
Dimethyl-Sulfide
Ethyl-Amine
Dimethylamine
Honoethanolamine
Ethylenediamine
Acrylonitrile
Acrylic-Acid
Allyl-Chloride
1, 2, 3-Trichloropropane
Propionitrile
Propylene
1, 2-Dichloropropane
A r* A + f\ n A
Acetone
Allyl-Alcohol
N-Propionaldehyde
Propylene-Oxide
Propionic-Acid
Methyl-Acetate
Propyl-Chloride
Isopropyl-Chloride
Propane
Formula
Constant
Refract.
Log(H)
Index
CAS No.
Atm-m3/gmole
C2H2CL4
C2H3CLF2
C2H3CL3
C2H3CL3
C2H3F3
C2H3N
C2H4
C2H4CL2-1
C2H4CL2-2
C2H4F2
C2H40-1
C2H40-2
C2H402-1
C2H402-2
C2H5BR
C2H5CL
C2H5F
C2H5N
C2H6
C2H60-1
C2H60-2
C2H602
C2H6S-2
C2H7N-1
C2H7N-2
C2H7NO
C2H8N2
C3H3N
C3H40
C3H402-1
C3H5CL
C3H5CL3
C3H5N
C3H6-2
C3H6CL2
C3H60-1
C3H60-2
C3H60-3
C3H60-4
C3H602-1
C3H602-3
C3H7CL-1
C3H7CL-2
C3H8
2. 50E-04
1.00E-02
1.74E-02
7.40E-04
8.40E«01
5.80E-06
4.42E-01
1.54E-02
1.20E-03
1.00E-02
9.50E-05
1.42E-04
6.27E-02
1.30E-01
1.00E-02
1.40E-02
1.00E-02
- 4.54E-04
1.00E-01
3. 18E-03
3.03E-05
1.03E-07
5.45E-03
5. 24E-06
5.24E-06
3.22E-07
8.46E-06
8.80E-05
5.66E-05
1.00E-07
3.71E-01
2.80E-02
2.75E-04
2.30E-03
2.50E-05
1.80E-05
1.50E-03
1.34E-03
4.87E-05
1.02E-04
1.30E-02
1.70E-02
2.20E-02
-3.60
-2.00
-1.76
-3.13
1.92
-5.24
-0.35
-1.81
-2.92
-2.00
-4.02
-3.85
-1.20
-0.89
-2.00
-1.85
-2.00
-3.34
-1.00
-2.50
-4.52
-6.99
-2.26
-5.28
-5.28
-6.49
-5.07
-4.06
-4.25
-7.00
-0.43
-1.55
-3.56
0.32
-2.64
-4.60
-4.74
-2.82
-2.87
-4.31
-3.99
-1.89
-1.77
-1.66
1,4940
1 . 3876
1.4379
1.4706
1.3876
1.3460
1.3630
1.4166
1.4448
1.2600
1 . 3392
1.3599
1.3515
1.3876
1.4239
1.3676
1.2656
.1.3876
.1 . 0377
1.3876
1.3611
1.4318
1.4355
1.3663
1.3500
1.4541
1.4540
1.3911
1.3970
1.4224
1.4154
1.4832
1.3630
1.3567
1.4394
1.3591
1.3876
1.3636
1.3670
1.3850
1 . 3600
1.3860
1.3777
1.2898
79-34-5
75-68-3
71-55-6
79-00-5
75-05-8
74-85-1
75-34-3
107-06-2
75-37-6
75-07-0
75-21-6
64-19-7
107-31-3
74-96-4
75-00-3
151-56-4
74-84-0
115-10-6
64-17-5
107-21-1
75-18-3
75-04-7
124-40-3
141-43-5
107-15-3
107-13-1
107-02-8
79-10-7
107-05-1
96-18-4
107-12-0
115-07-1
78-87-5
67-64-1
107-18-6
123-38-6
75-56-9
79-09-4
79-20-9
540-54-5
75-29-6
74-98-6
A2
-------
Component Name
Henry's Law
Formula Constant Log(H)
Atm-m3/gmole
Refract.
Index CAS
No.
1-Propanol
Isopropyl-Alcohol
Methyl-Ethyl-Ether
Propanediol-1, 2
Glycerol
N-Propyl-Amine
Isopropyl-Amine
Maleic- Anhydride"
Furan
1, 2-Butadiene
1, 3-Butadiene
Vinyl-Acetate
Acetic-Anhydride
Succinic-Acid*
Methyl-Acrylate-
N-Butyraldehyde
Isobutyraldehyde
Methyl-ethyl-ketone
Tetrahydrof uran
1, 4-Dioxane
Ethyl-Acetate
Morpholine*
N-Butane
Isobutane
N-Butanol
2-Butanol
Isobutanol
Tert -Butyl -Alcohol
Diethyl-Ether
Diethylene-Glycol
Diethyl-Amine
Pyridine
Ethyl-Acrylate*
Cyclopentane
1-Pentene
Cis-2-Pentene
Trans-2-Pentene
2-Hethyl-l-Butene
Methyl -N-Propyl-Ketone
Methyl -Isopropyl-Ketone"
N-Propyl-Acetate
Ethyl -Propionate
N-Pentane
2-Methyl-Butane
C3H80-1
C3H80-2
C3H80-3
C3H802-2
C3H803
C3H9N-1
C3H9N-2
C4H203
C4H40
C4H6-3
C4H6-4
C4H602
C4H603
C4H604-2
C4H702
C4H80-1
C4H80-2 -
C4H80-3
C4H80-4
C4H802-2
C4H802-3
C4H9NO
C4H10-1
C4H10-2
C4H100-1
C4H100-2
C4H100-3
C4H100-4
C4H100-5
C4H1003
C4H11N-3
C5H5N
C5H802
C5H10-1
C5H10-2
C5H10-3
C5H10-4
C5H10-5
C5H100-2
C5H100-3
C5H1002-3
C5H1002-4
C5H12-1
C5H12-2
1.50E-04
1.50E-04
1.50E-04
1.50E-06
1.30E-08
3.58E-04
3.5SE-04
4.00E-08
5.34E-03
1.42E-01
1.42E-01
6.20E-04
5.91E-06
1.74E-09
1.44E-07
2.58E-04
1.47E-04
2.16E-04
4.90E-05
2.31E-05
1.28E-04
5.73E-05
2.91E-01
2.91E-01
2.20E-06
2.20E-06
2.20E-06
2.20E-06
2.65E-04
1.40E-06
7.31E-03
2. 36E-05
3. 50E-04
1.00E-02
1.00E-01
1.00E-01
1.00E-01
1.00E-01
4.58E-04
4.58E-04
2.94E-04
2. 94E-04
1.22E-01
1.22E-01
-3.82
-3.82
-3.82
-5.82
-7.89
-3.45
-3.45
-7.40
-2.27
-0.85
-0.85
-3.21
-5.23
-8.76
-6.84
-3.59
-3.83
-3.67
-4.31
-4.64
-3.89
-4.24
-0.54
-0.54
-5.66
-5.66
-5.66
-5.66
-3.58
-5.85
-2.14
-4.63
-3.46
-2.00
-1.00
-1.00
-1.00
-1.00
-3.34
-3.34
-3.53
-3.53
-0.91
-0.91
1.3830
1.3776
1.3420
1.4310
1.4729
1.3860
1.3876
1.3876
1.4214
1.4205
1.4292
1.3959
1.3890
1.4500
1.4040
1.3780
1.3876
1.3788
1.4040
1.4221
1.3700
1.4548
1.3543
1.3876
1.3970
1.3950
1.3939
1.3878
1.3526
1.4450
1.3864
1.5070
1.3876
1.4040
1.3715
1.3830
1.3793
1.3378
1.3900
1. 3876
1.3820
1.3820
1.3575
1.3537
71-23-8
67-63-0
57-55-6
56-81-5
107-10-8
75-31-0
108-31-6
110-00-9
590-19-2
106-99-0
108-05-4
108-24-7
110-15-6
96-33-3
123-72-8
78-84-2
78-93-3
109-99-9
123-91-1
141-78-6
110-91-8
106-97-8
75-28-5
71-36-3
15892-23-6
78-83-1
75-65-0
60-29-7
111-46-6
109-89-7
110-86-1
140-88-5
287-92-3
109-67-1
627-20-3
646-04-8
563-46-2
107-87-9
563-80-4
109-60-4
105-37-3
109-66-0
78-78-4
A3
-------
Component Name
2,2-Dimethyl-Propane
1-Pentanol
2-Methyl-l-Butanol
2,2-Dimethyl-l-Propanol
Ethyl-Propyl-Ether"
0-Dichlorobenzene
H-Dichlorobenzene
P-Dichlorobenzene
Brotnobenzene
Chlorobenzene
Benzene
Phenol
Aniline
4-Methylpyridine
Cyclohexene
Cyclohexanone
Cyclohexane
Methylcyclopentane
1-Hexene
Cis-2-Hexene
Trans-2-Hexene
Cyclohexanol
Methyl-Isobutyl-Ketone
N-Butyl-Acetate
Isobutyl-Acetate
N-Hexane
2-Methyl-Pentane
1-Hexanol
Dipropylamine*
Triethylamine
Benzonitrile
Benzaldehyde
Benzoic-Acid
Toluene
Benzyl-Alcohol
0-Cresol
n-Cresol
P-Cresol
P-Toluidine*
Cycloheptane
Hethylcyclohexane
1-Heptene
H-Heptane
2-Hethylhexane
Henry's Lav
Formula
Constant
Refract.
Log(H)
Index
CAS No.
Atm-m3/gmole
C5H12-3
C5H120-1
C5H120-2
C5H120-5
C5H120-6
C6H4CL2-1
C6H4CL2-2
C6H4CL2-3
C6H5BR
C6H5CL
C6H6
C6H60
C6H7N-1
C6H7N-2
C6H10-2
C6H100
C6H12-1
C6H12-2
C6H12-3
C6H12-4
C6H12-5
C6H120-1
C6H120-2
C6H1202-1
C6H1202-2
C6H14-1
C6H14-2
C6H140-1
C6H15N-1
C6H15N-2
C7H5N
C7H60
C7H602
C7H8
C7H80-2
C7H80-3
C7H80-4
C7H80-5
C7H9N-8
C7H14-1
C7H14-6
C7H14-7
C7H16-1
C7H16-2
1.22E-01
6.00E-06
6.00E-06
6.00E-06
2.65E-04
1.94E-03
3.61E-03
1.60E-03
3.93E-03
3.93E-03
5.50E-03
4.54E-07
2. 60E-06
1.27E-04
1.03E+01
4.13E-06
1.37E-02
1.37E-02
1.00E-01
1.00E-01
1.00E-01
4.47E-06
4.95E-05
1.64E-04
1.64E-04
1.22E-01
7.61E-01
1.82E-05
2.53E-04
2. 66E-03
1.36E-05
4.23E-05
1.82E-08
6.63E-03
6. 10E-07
2. 60E-06
4.43E-07
4.43E-07
1.91E-05
9.79E-01
9.79E-01
1.00E-01
2.02E»00
2.02E»00
-0.91
-5.22
-5.22
-5.22
-3.58
-2.71
-2.44
-2.80
-2.41
-2.41
-2.26
-6.34
-5.59
-3.90
1.01
-5.38
-1.86
-1.86
-1. 00
-1.00
-1.00
-5.35
-4.31
-3.79
-3.79
-0.91
-0.12
-4.74
-3.60
-2.58
-4.67
-4.37
-7.74
-2.18
-6.21
-5.59
-6.35
-6.35
-4.72
-0.01
-0.01
-1.00
0.31
0.31
1.3537
1.4080
1.4090
1.3876
1.3695
1.5510
1.5430
1.5266
1.5597
1.5248
1.5011
1.5400
1. 5830
1 . 5037
1.4465
1.4503
1.4266
1.4070
1.3837
1.3977
1.3935
1.4650
1.3940
1.3920
1.3876
1.3749
1.3715
1.4135
1.4030
1.3990
1.5289
1.5440
1.5040
1.4969
1.5380
1.5361
1.5438
1.5312
1.5636
1.4436
1.4253
1.3998
1.3876
1.3820
80-05-7
71-41-0
137-32-6
75-84-3
628-32-0
95-50-1
541-73-1
106-46-7
108-86-1
108-90-7
71-43-2
108-95-2
62-53-3
109-06-8
110-83-8
108-94-1
110-82-7
96-37-7
592-41-6
592-43-8
4050-45-7
108-93-0
108-10-1
123-86-4
110-19-0
110-54-3
107-83-5
111-27-3
142-84-7
121-44-8
100-47-0
100-52-7
65-85-0
108-88-3
100-51-6
95-48-7
108-39-4
106-44-5
106-49-0
291-64-5
108-87-2
592-76-7
142-82-5
591-76-4
A4
-------
Component Name
3-Methylhexane
1-Heptanol
Phthaiic-Anhydride
Styrene
Methyl-Phenyl-Ketone
0-Xylene
M-Xylene
P-Xylene
Ethylbenzene
2, 4-Xylenol'
N-Qctane
2-Methylheptane
2,2,4-Trimethylpentane
1-Octanol
2-Octanol*
2-Ethylhexanol
Alpha-Methyl-Styrene'
N-Propylbenzene
Isopropylbenzene
l-«ethyl-2-£thylbenzene
1-Methyl-3-Ethylbenzene
l*flethyl-4-Ethylbenzene
1, 2, 3-Tnmethylbenzene
1, 2, 4-Trimethylbenzene
1,3,5-Trimethylbenzene
N-Nonane
Naphthalene
N-Butylbenzene
N-Decane
1-Decanol
1-Methylnaphthalene
2-Hethylnaphthalene
Diphenyl
Diphenyl-Ether
Anthracene
Phenanthrene
Dibutyl-0-Phthalate'
N-Dodecylcyclopentane
Formula
C7H16-3
C7H160
C8H403
C8H8
C8H8Q
C8H10-1
C8H10-2
C8H10-3
C8H10-4
caHi0o-6
C8H18-1
C8H18-2
C8HI8-13
C8H180-1
C8H180-2
C8H180-3
C9H10
C9H12-1
C9H12-2
C9H12-3
C9H12-4
C9H12-5
C9H12-6
CSH12-7
C9H12-8
C9H20-1
C10H8
CieH14-l
C10H22-1
C10H220
C11H10-1
C11H10-2
C12H10
C12H100
C14H10-1
C14H10-2
C16H2204
C17H34
Henry's Law
Constant
Atm-m3/gmole
2.02E*00
1.82E-05
9.00E-07
2. 61E-03
1.41E-05
5.27E-03
5.20E-03
5.27E-03
6.44E-03
9.21E-04
3.87E»00
3.87E*00
1.09£*01
4.34E-05
4.34E-05
6. 17E-05
5.91E-03
"6.59E-03
6.59E-03
5.58E-C3
3.11E-02
5.58E-03
1.47E-01
1.47E-01
1.47E-01
4.48E-01
4.80E-04
8. 83E-02
3.87E-00
4.34E-05
7. 10E-04
5. 80E-05
1.01E-01
2. 24E-03
6. 75E-02
6.05E-03
2.80E-07
2. 52E*01
Log(H)
0.31
-4.74
-6.05
-2.58
-4.85
-2.28
-2.28
-2.28
-2.19
-3.04
0.59
0.59
1.04
-4.36
-4.36
-4.21
-2.23
-2. 18
-2. 18
-2.25
-1.51
-2.25
-0.83
-0.83
-0.83
-0.35
-3.32
-1.05
0.59
-4.36
-3. 15
-4.24
-1.00
-2.65
-1. 17
-2.22
-6.55
1. 40
Refract.
Index
1.3860
1.4220
1.3876
1.5469
1.5372
1.5055
1.4972
1.4958
1.4930
1.3876
1.3975
1.3949
1.3915
1.4270
1.4264
1.4328
1.3876
1.4900
1.4890
1.5046
1.4966
1.4959
1.5139
1.5048
1.4994
1.4030
1.4003
1.4870
1.4102
1.4372
1.6170
1.6019
1.3876
1.5787
1.3876
1.5943
1.4900
1.3876
CAS No.
583-34-4
111-70-6
85-44-9
100-42-5
98-86-2
95-47-6
108-38-3
106-42-3
100-41-4
105-67-9
111-65-9
592-27-8
540-84-1
111-87-5
4128-31-8
104-76-7
98-83-9
103-65-1
98-82-8
611-14-3
620-14-4
622-96-3
526-73-8
95-63-6
108-67-8
111-84-2
91-20-3
104-51-8
124-18-5
112-30-1
90-12-0
91-57-6
92-52-4
101-84-8
120-12-7
85-01-8
84-74-2
A5
-------
APPENDIX B
A SAMPLE CASE STUDY REPORT
Rating Mode - Carbon Adsorption Option
-------
RESULTS OF
AIR STRIPPING SIMULATION
USING ASPEN
A Saiple Case Study
By
Ashok S. Damle
07/24/9e
Bl
-------
AIR STRIPPER MODEL BACKGROUND
Air stripping of volatile organic chemicals from wastewater is an
effective method of wastewater treatment associated with the cleanup of
superfund sites. U. S. EPA-Office of Air Quality and Planning and
Standards (EPA-OAQPS), has sponsored development of an ASPAIR computer model
package to describe the air stripping process along with processes for
controlling the resulting air emissions. As a part of this package,
interactive PC-based software has been developed to allow a user running an
ASPEH air stripping simulation without any knowledge of ASPEN programming.
ASPEN is an acronym representing "Advanced System for Process ENgineering,• a
software package available commercially for chemical process design and
simulation. ASPEN allows modular building of flowsheet blocks to represent
an air stripper with or without air emission controls. It also contains an
extensive physical property library.
The process simulated by the air stripping model is shown schematically in
Figure 1. This model can be run in one of two modes: rating mode and design
mode. In the rating mode a specific, known air stripper design can be
evaluated by inputting basic design parameters such as flow rates, concentra-
tions, and tower dimensions and then comparing the predicted performance
results with observed ones. Similar information would also be required for
any existing air emission control device. The rating mode also allows "what
if...• calculations by changing the operating parameters such as air/water
ratio and influent concentrations.
In the design mode one needs to provide the wastewater flow rate, influent
concentrations, desired removal rates or effluent concentrations, air to
water ratio, and the air emission control selected. The model will calculate
the necessary optimum tower design to achieve the specified effluent limits,
and provide sizing information for the selected control equipment. In both
modes the air stripper ASPAIR model determines the capital and operating
costs associated with the stripper as well as the control equipment. The
output for each mode is provided in units typically used in describing
equipment dimensions, flows, and concentrations.
The ASPAIR air stripper model allows two options for controlling the VOC
air emissions: 1) adsorption on a fixed bed of activated carbon, and 2)
catalytic oxidation of the VOC's at an appropriate temperature to assure
complete destruction of the YOC's. A model has also been developed for
describing adsorption of the VOC's on carbon based on Polanyi's 'generalized
isotherm' concept. The catalytic oxidation operation uees an auxiliary fuel
such as natural gas to maintain the desired temperature of the catalytic
combustor.
B2
-------
Contaminated
Water
Storage
Tank
(Optional)
Pump
voc
Control
(Optional)
Packing
Air
'Clean" Water
Figure 1. Diagram of the air stripping process.
B3
-------
STRIPPER SITE INFORMATION
SITE DESCRIPTION
Site Nave: ABC
Site Address: 123 Main Street
An/town AB 12345
Contact Person: John Doe
STRIPPER STATUS
X Existing stripper He* Design
AIR EMISSIONS CONTROL STATUS
None
X Vapor phase carbon adsorption
Catalytic oxidation
-------
SUMMARY OF INPUT DATA
SIMULATION MODE
X Rating (Performance) Mode
Design Mode
VASTEWATER STREAM INFORMATION
Flov Rat*
Temperature
6.31E+01 (Kg/8)
12.78 ( C)
CONCENTRATION OF VOC'S IN WASTE*ATER
VOC Mane
Tetrachloroethylene (C2CL4)
Trichloroethylene (C2HCL3)
1,1-Dichloroethane (C2H4CL2-1)
Benzene (C6H6)
Concentration H Value
(ppbv or ug/1) (at»-«3/g*ole)
i.00E»03
1.00E+03
1.00E*03
2. 90E-02
9.10E-03
1.54E-82
5.50E-03
B5
-------
SUMMARY OF INPUT DATA (cont'd)
INPUT DATA FOR THE RATING MODE
TOWER DIMENSIONS
Tover Diameter 1.83E+0C (H)
Packing Height 1.00E*01 (H)
Total Height 1.15E*81 (H)
AIR STREAM INFORMATION
Air Flow Rate 1.51E+00 (Kg/a)
Air Temperature 2.0CE*01 < C)
Air to water ratio 2.00E»«1
INPUT DATA FOR THE DESIGN MODE
Design Component
Target removal efficiency of the design component
Target effluent concentration of the design (ppbw)
component
Air to Water Ratio (vol/vol)
Air Temperature < C)
Air Flo* Rate (Kg/a)
B6
-------
SUMMARY OF INPUT DATA (cont'd)
CONTROL UNIT DATA
Carbon Adsorption:
Carbon Regeneration Mode — On-site
Carbon replacement cost
Off-eite regeneration cost
No. of Carbon Beds
Adsorption Cycle Tiae
Aaount of Carbon per Bed
4.41E+00 (9/Kg)
1.76E»00 (S/Kg)
2
2.40E*ei (Mrs)
3.50E*B2 (Kg)
Catalytic Oxidation:
Cost of natural gas (fuel)
Temperature of coabustor
(S/H3)
( C)
COST DATA
Labor rate 1.20E+01 (S/Hr)
Annual labor 2.80E»03 (Hr/Yr)
Operating Days per Year 3.65E+02 (Days/Yr)
Cooling vater cost 3.60E-05 (S/Lb)
Steam cost 6.00E-03 (9/Lb)
Electricity cost 6.00E-02 ($/KvHr)
Equipment service life 1.00E»01 (Yrs)
Interest rate 1.00E+01 (X)
AUXILIARY EQUIPMENT DATA
Liquid Phase Carbon Polishing Bed Not Present
Waste»ater Storage Tanks Not Present
B7
-------
SUMMARY OF AIR STRIPPER SIMULATION RESULTS
- STRIPPER COLUMN DATA:
Tover Diameter
Packing Height
Total Height
Height of a Transfer Unit
Number of Transfer Units
Air-to-water ratio, (vol. )
1.83
10.00
11.52
1.17
a. 54
20.00
(meters)
(meters)
(meters)
(meters)
PERFORMANCE DATA:
• OVERALL MATERIAL BALANCE •
Total Wastevater Feed to the Stripper
Effluent (Treated) Water Flo*
Air Flo* to the Stripper
Air Flow Leaving the Stripper
Temperature of Air Leaving Stripper
Total VOCs in Wastewater
Total VOCs in Effluent Water
Total VOCs in Air Emissions
(before VOC Control Unit)
VOC Removal Efficiency of Stripper
2,. 2713E*05
2.2712E*05
5.4389E+03
5.4398E+03
1.2778E*01
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
( C)
9.0850E-01 (kg/hr)
1.6549E-03 (kg/hr)
9.0685E-01 (kg/hr)
99.82 (X)
INDIVIDUAL VOC COMPONENT MATERIAL BALANCE
VOC Name
In with
Wastevater
Out with
Effluent Water
(Stripper)
ppmv
kg/h
ppmv
kg/h
Out with
Air Emissions
(Overhead)
ppmv kg/h
Removal
Efficiency
- X -
C2CL4
C2HCL3
C2H4CL2-1
C6H6
1.0E»00 2.3E-01
1.0E+00 2.3E-01
1.0E+00 2. 3E-01
1.0E+00 2.3E-01
3.6E-04 8.2E-05
1.4E-03 3.2E-04
3. 5E-04 7.9E-05
5.2E-03 1.2E-03
7. 2E*00 2.3E-01
9. 1E»00 2. 3E-01
1.2E+01 2. 3E-01
1.5E*01 2.3E-01
99.96
99.86
99.97
99.48
B8
-------
PREDICTED CAPITAL AND ANNUAL COSTS - AIR STRIPPER
(1989 Dollars)
- TOTAL CAPITAL INVESTMENT -
Air Stripper Column
Process Fan (Blover)
Wastevater Pump(s)
» 55950.
$ 1440.
» 4890.
Total Base Equipment Cost $ 62280.
Total Capital Investment $ 118320.
(Includes Instrumentation, Sales Tax,
Freight and Installation)
- TOTAL ANNUALIZED COSTS -
Operating and Maintenance Labor,
including Overhead
Utilities (Electricity) Cost
Miscellaneous Costs
Annual Operating Costs
Capital Investment Cost
»
*
55920. /yr
4640. /yr
4730. /yr
9 65290. /yr
* 19260. /yr
Total Annualized Costs
84550. /yr
B9
-------
PREDICTED CAPITAL AND ANNUAL COSTS - AIR EMISSIONS CONTROL
(1989 Dollars)
CARBON ADSORBER UNIT:
TOTAL CAPITAL INVESTMENT -
Carbon Adsorber System (vapor-phase)
Initial Carbon Loading Charge
* 61800.
9 3090.
Total Base Equipment Cost
Total Capital Investment
(Includes Instrumentation, Sales Tax,
Freight and Installation)
$ 64890.
$ 123280.
» TOTAL ANNUALIZED COSTS -
Operating and Maintenance Labor,
including Overhead
Utilities (Electricity) Cost
Miscellaneous Costs
Carbon replacement / regeneration cost
(Note: breakdown of the carbon cost
by each VOC is given belov)
Annual Operating Costs
Capital Investment Cost
$
9
$
$
9
36270. /yr
1400. /yr
4930. /yr
3220. /yr
45820. /yr
19508. /yr
Total Annualized Costs
VOC removal rate in Control Unit
Cost Effectiveness of Control Unit
$ 65328. /yr
7.944E»00 HG/yr
$ 8.224E*03 /HG removed
BIO
-------
Not*:
Design amount of carbon in bed(s) * 6.690E»02 Kg
Actual aaount of carbon in bed(e) = 7.000E»02 Kg
• CARBON REOUIREHENT AND COSTS FOR EACH VOC COHPONENT t
VOC Naae X of Total Design Carbon Replac.-
Carbon Requirement Regen. Costs ($/yr)
C2CL4 1.10E»01 3.55E*02
C2HCL3 1.84E+01 5.93E*02
C2H4CL2-1 4.24E*01 1.36E*03
C6H6 2.82E*01 9.07E*02
Bll
-------
NET AIR EMISSIONS ANALYSIS
Air Flov fro» Adsorber
Tenperature of Air
Water Vapor in Air
Uncontrolled VOC emissions
4.677E+03 <«3/hr)
1.278E*ei ( C)
i.417E*00 (vol. X)
9.068E-ei (kg/hr)
Individual pollutant enissions generated during
heat generation required for carbon regeneration;
S02
NOx
CO
VOC (non»ethane)
C02
Total eaissions attributed to
the adsorber (excluding C02)
Net emissions reduction
(excluding C02)
9. 567E-83
1.348E-03
3.370E-04
1.872E-05
i.532E»0e
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
1.127E-82 (kg/hr)
8.956E-01 (kg/hr)
NOTE: The aqueous condensate froi the adsorber
regeneration is routed to the feed storage
tank(s). Condensed organics phase »ay
assumed to be recovered for reuse.
B12
-------
APPENDIX C
A SAMPLE CASE STUDY REPORT
Design Mode - Catalytic Oxidation Option
-------
RESULTS OF
AIR STRIPPING SIMULATION
USING ASPEN
A Saaple Case Study
By
Ashok S. Daile
07/24/90
Cl
-------
AIR STRIPPER MODEL BACKGROUND
Air stripping of volatile organic chemicals from wastewater is an
effective method of wastewater treatment associated with the cleanup of
superfund sites. U. S. EPA-Office of Air Quality and Planning and
Standards (EPA-OAQPS), has sponsored development of an ASPAIR computer model
package to describe the air stripping process along with processes for
controlling the resulting air emissions. As a part of this package,
interactive PC-based software has been developed to allow a user running an
ASPEH air stripping simulation without any knowledge of ASPEH programming.
ASPEH is an acronym representing "Advanced System for Process Engineering,• a
software package available commercially for chemical process design and
simulation. ASPEH allows modular building of flowsheet blocks to represent
an air stripper with or without air emission controls. It also contains an
extensive physical property library.
The process simulated by the air stripping model is shown schematically in
Figure 1. This model can be run in one of two modes: rating mode and design
mode. In the rating mode a specific, known air stripper design can be
evaluated by inputting basic design parameters such as flow rates, concentra-
tions, and tower dimensions and then comparing the predicted performance
results with observed ones. Similar information would also be required for
any existing air emission control device. The rating mode also allows fwhat
if...• calculations by changing the operating parameters such as air/water
ratio and influent concentrations.
In the design mode one needs to provide the wastewater flow rate, influent
concentrations, desired removal rates or effluent concentrations, air to
water ratio, and the air emission control selected. The model will calculate
the necessary optimum tower design to achieve the specified effluent limits,
and provide sizing information for the selected control equipment. In both
modes the air stripper ASPAIR wodel determines the capital and operating
costs associated with the stripper as well as the control equipment. The
output for each mode is provided in units typically used in describing
equipment dimensions, flows, and concentrations.
The ASPAIR air stripper model allows two options for controlling the VOC
air emissions: 1) adsorption on a fixed bed of activated carbon, and 2)
catalytic oxidation of the VOC's at an appropriate temperature to assure
complete destruction of the VOC's. A model has also been developed for
describing adsorption of the VOC's on carbon based on Polanyi's 'generalized
isotherm' concept. The catalytic oxidation operation uses an auxiliary fuel
such as natural gas to maintain the desired temperature of the catalytic
combustor.
C2
-------
Contaminated
Water
Storage
Tank
(Optional)
Pump
voc
Control
(Optional)
Packing
Air
"Clean"' Water
Figure 1. Diagram of the air stripping process.
C3
-------
STRIPPER SITE INFORMATION
SITE DESCRIPTION
Site Nase: ABC
Site Address: 123 Hain Street
Anytovn AB 12345
Contact Person: John Doe
STRIPPER STATUS
Existing stripper X New Design
AIR EMISSIONS CONTROL STATUS
None
Vapor phase carbon adsorption
X Catalytic oxidation
-------
SUMMARY OF INPUT DATA
SIMULATION MODE
Rating (Performance) Mode
Design Mode
WASTEWATER STREAM INFORMATION
Flov Rate
Temperature
6.31E»0i (Kg/s)
12.78 < C)
CONCENTRATION OF VOC'S IN WASTEWATER
VOC Name
Tetrachloroethylene (C2CL4)
Trichloroethylene (C2HCL3)
Vinyl-Chloride (C2H3CL)
1,1-Dichloroethane (C2H4CL2-1)
Benzene (C6H6)
Concentration
(ppbv or ug/1)
1. 00E+03
i.00E*03
H Value
(at«-«3/g»ole)
2.90E-02
9.10E-03
8.60E-02
1.54E-02
5.50E-03
C5
-------
SUMMARY OF INPUT DATA (cont'd)
IHPUT DATA FOR THE RATING BODE
TOWER DIMENSIONS
Tower Diameter (H)
Packing Height (H)
Total Height (H)
AIR STREAM INFORMATION
Air Flov Rate (Kg/a)
Air Temperature ( C)
Air to vater ratio (vol/vol)
INPUT DATA FOR THE DESIGN MODE
Design Component: Trichloroethylene
Target removal efficiency of the design component 9.90E*01 (X)
Target effluent concentration of the design 1.00E*01 (ppbv)
component
Air to Water Ratio 2.00E«01 (vol/vol)
Air Temperature 2.00E*01 ( C)
Air Flov Rate 1.31E«00 (Kg/*)
C6
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SUMMARY OF INPUT DATA (cont'd)
CONTROL UNIT DATA
Carbon Adsorption:
Carbon Regeneration Mode -- Off-site
Carbon replacement cost
Off-site regeneration cost
No. of Carbon Beds
Adsorption Cycle Ti»e
Amount of Carbon per Bed
($/Kg)
($/Kg)
(Hrs)
(Kg)
Catalytic Oxidation:
Cost of natural gas (fuel)
Tenperature of combustor
1.77E-01 (S/H3)
3. 71E*02 ( C)
COST DATA
Labor rate 1.20E*01 (9/Hr)
Annual labor 2.00E*03 (Hr/Yr)
Operating Days per Year 3.65E*02 (Days/Yr)
Cooling water cost 3.60E-05 (9/Lb)
Stea» cost 6. 00E-03 ($/Lb)
Electricity cost 6.00E-02 («/K»Hr)
Equipment service life 1.00E+01 (Yrs)
Interest rate 1.00E»01 (X)
AUXILIARY EQUIPMENT DATA
Liquid Phase Carbon Polishing Bed — Not Present
Wastevater Storage Tanks — Not Present
C7
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SUHHARY OF AIR STRIPPER SIMULATION RESULTS
- STRIPPER COLUMN DATA:
Tower Diameter
Packing Height
Total Height
Height of a
ATA:
ter
ght
9
t
, Transfer Unit
ranafer Unit*
>r ratio, (vol. )
1.52
7.48
9.48
1.32
5.68
20.00
(meters)
(meters)
( aeters)
(meters)
PERFORMANCE DATA:
* OVERALL MATERIAL BALANCE •
Total Waetewater Feed to the Stripper
Effluent (Treated) Water Flow
Air Flow to the Stripper
Air Flo* Leaving the Stripper
Tenperature of Air Leaving Stripper
Total VOCa in Wastewater
Total VOCa in Effluent Water
Total VOC0 in Air E»i«sions
(before VOC Control Unit)
VOC Removal Efficiency of Stripper
2.2713E*05
2.2712E»05
5.4389E+03
5.4400E+03
1.2778E*01
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
( C)
1.1356E>00 (kg/hr)
9.S429E-03 (kg/hr)
1.1261E»00 (kg/hr)
99.16 (X)
INDIVIDUAL VOC COMPONENT MATERIAL BALANCE •
VOC Name
C2CL4
C2HCL3
C2H3CL
C2H4CL2-1
C6H6
In with
Wastevater
ppmv kg/h
1.0E«00 2.3E-01
1.0E+00 2.3E-01
1.0E«00 2.3E-01
1.0E+00 2.3E-01
1.0E«00 2.3E-01
Out with
Effluent Water
(Stripper)
ppaw kg/h
4.3E-03 9.7E-04
1.0E-02 2.3E-03
8.5E-04 1.9E-04
4.0E-03 9.2E-04
2.3E-02 5.2E-03
Out with
Air Emissions
(Overhead)
pp«v kg/h
7.2E*00 2.3E-01
9.0E«00 2.2E-01
1.9E*01 2.3E-01
1.2E»01 2.3E-01
1.5E*01 2.2E-01
Removal
Efficiency
- X -
99.57
99.00
99.92
99.60
97.71
C8
-------
PREDICTED CAPITAL AND ANNUAL COSTS - AIR STRIPPER
(1989 Dollars)
- TOTAL CAPITAL INVESTMENT -
Air Stripper Colunn
Process Fan (Blower)
Wastevater Pu»p(s)
9 36210.
* 1430.
« 4890.
Total Base Equip»ent Cost
Total Capital Invest»ent
(Includes Instrumentation, Sales Tax,
Freight and Installation)
9 42530.
9 80810.
- TOTAL ANNUALIZED COSTS -
Operating and Maintenance Labor,
including Overhead
Utilities (Electricity) Cost
Miscellaneous Costs
Annual Operating Costs
Capital Investment Cost
9
9
9
9
53520. /yr
3440. /yr
3230. /yr
60190. /yr
13150. /yr
Total Annualized Costs
73340. /yr
C9
-------
PREDICTED CAPITAL AND AHHUAL COSTS - AIR EMISSIONS CONTROL
(1989 Dollars)
CATALYTIC OXIDATION UNIT:
TOTAL CAPITAL INVESTMENT -
Catalytic Oxidation Unit
Including Initial Catalyst Charge
114460.
Total Base Equipment Cost
Total Capital Investment
(Includes Instrumentation, Sales Tax,
Freight and Installation)
* 114460.
* 217450.
- TOTAL ANNUALIZED COSTS -
Operating and Maintenance Labor,
including Overhead
Utilities (Electricity) Cost
Miscellaneous costs
Catalyst Replacement Cost
Auxiliary Fuel (methane)
*
9
*
t
36270. /yr
4200. /yr
8700. /yr
7520. /yr
48990. /yr
Annual Operating Costs
Capital Investment Cost
9 105680. /yr
9 33264. /yr
Total Annualized Coats
VOC removal rate in Control Unit
Cost Effectiveness of Control Unit
$ 138944. /yr
9.864E+00 HG/yr
9 1.409E+04 /HG removed
CIO
-------
NET AIR EMISSIONS ANALYSIS
Gas Flov fro« Catalytic Oxid.
Tenperature of Exhaust Gas
Water Vapor in Exhaust Gas
Uncontrolled VOC enissions
Individual pollutant enissions
after a cat. oxidizer:
HX (halogens)
S02
NOx
CO
VOC (non»ethane)
C02
Total Emissions after the cat*
oxidizer (excluding C02)
Net emissions reduction
(excluding C02)
7.334E*03
1.919E+02
4.093E+00
6.85SE-01
3.193E-02
5.519E-02
1.126E-02
2.751E-03
6.565E+01
(«3/hr)
( C)
(vol. X)
1.126E+00 (kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
(kg/hr)
7.869E-01 (kg/hr)
3.392E-01 (kg/hr)
Cll
-------
APPENDIX D
Sample Form N258 - EPA ADP IBM. LMF. & vax
Account and User Registration
-------
EPA ADP IBM, LMF, & VAX ACCOUNT AND USER REGISTRATION^
•••••••••••••••
THIS REQUEST: TC
-------
USERS ASSIGNED TO ACCOUNT
(Please Print or Type)
USER NAME (Uat. Flnt, M.L)
Mai Coda (or room) Ofc» and* Company
Addr*M(Sr*«orP.O.Box) CHy
Phon*
(FTS)
or
•
Phona (IncBjda
•raacoda)
Ui*r WSaJa^
SpMial FMturv*
0 9
D O«h*r
UaarTypa
DC DU
OF 00
DE OS
UpdataAcskM D AddUaar O 0*l*a)Ua*r O Changa u**r Wormaaon a* tetad abov*.
USER] NAME (UU. FlrU. MO.)
Mai Coda (or room) O«ea and* Company
AddTMt (St**t or P. a Box) CHy
(FTS)
or
-
Phona (Indud*
•raacoda)
Sat*
TSSMS-Anignad
Spadai FMtL»*«
0 S
D OtJw
U**rTyp*
DC DU
DF DO
DE OS
Updato Action D AddUaar D OalataUtar O Changa v**r WormaJon a* fatad above.
USER NAME (Last. First. M.L)
Mai Coda (or room) Orfica and* Company
Addnm(SwtorP.O.Box) Oty
Phona
(FTS) -
or
Phona (Indud*
araaooda)
Stata
Zip Cod*
TSSMS-Aacigrwd
Soadal Faaitjrai
0 8
O O**
UaarTypa
DC DU
DF DO
OE OS
UpdtM Action D AddUMr O DatataUtat O Chang* usar Hormaton aa htad abov*.
USER] NAME (U«. firu. U.I.)
Mai Cod* (or room) Orfica and* Company
Addraaa (S»Mt or P. O. Box) dry
KTaOOB
(FTS) -
or
Phona (Indud*
•raaooo*)
Stav
Zip Coda
UMTlrMala
TSSMS-AMlfnad
Spacial Faaturat
0 S
O Otfwr
UaarTyp*
DC DU
DF DO
DE OS
UpdattAcdon Q Addl^r O D.<..U*w D O^g. ui*r Worma«on « k>*d tfo««.
USER NAME (Last. Fht. M.I.)
Mai Cod* (or room) Otto* and* Company
Addnua (Sva« or P. O. Box) Ctty
(FTS)
or
-
Phona (liduda
araieoda)
Slat*
Zip Cod*
UMrbtfate
TSSMS-Auignad
Sp*ctat F*amr*(
0 S
D Otfwr
UtarTyp*
DC DU
DF DO
DE DS
Uodato Action D AddUaar D Dal«»U*ar D Changa MM Normaoon as Huad abova.
TSSMS USP OM v 1
JSSMS use ONLY
JSSMS USE ONLY
JSSMS USE ONLY
^MM— Mi^"»""""ii™— •
I5SWS USE ONLY
USER(S) UPDATE
ACCO' !VT NO CHECK HERE IF CHANGE OF ADDRESS ONLY
CD A »rrvMiwT UAMiftPR
S/SpSS«Zwi l&grawftequrKl) Hho«e uuiu |
N2S«(PAGC2)
D2
-------
APPENDIX £
EXAMPLE OF COMMUNICATION PARAMETERS SETTING
ON CROSSTALK STATUS SCREEN
-------
CROSSTALK - XVI Status Screen
NAme CROSSTALK defaults Hayes Smartmodem 2400 LOaded C:STO.XTK
NUmber 5410700 CApture Off
Communications parameters Filter settings
SPeed 2400 PArity Even OUplex Full OEbug Off LFauto Off
DAta 7 SToo 1 EMulate YT-100 TAbex Off Blankex Off
J0rt j MOde Call INfilter On OUTfiltr On
Key settings SEnd control settings-
ATten Esc COmmand ETX (~C) CWait
Switch Home BReak End LWait None
Available command files
1) IBM-ISO 2) NEWUSER 3) SETUP 4)STO
Enter number for file to use (1 - 4):
El
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