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A-39
-------
APPENDIX B
EMISSION DATA PROFILES
-------
I,
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B-l
-------
TABLE B-I DISTILLATION EMISSION DATA PROFILE
PRODUCT
PROCESS
Chlorobenzeoe
Aniline
Chlorobenzene
Chiorooenzene
Aniline
Chlorobenzene
Terephthalic Acid
Confidential
Ethyl benzene
Methyl MethacryUte
84
Acetone
Acetone
Acetic ACid
Chloroprene
Malic Anhydride
Confidential
Dimethyl Terephthalate
Chloroprene
Acetic Anhydride
Phtnalic Anhydride
Ethytacetate
Ethyldichlonde
Alkyl Benzene
Acetic Anhydride
Perchlorocthylene
Acetone
Acetone
Acetic Acid
Acetone
Nitrobenzene
Methyl Methaciylate
Chloroprene
Dichlorobenzene
Acetic Acid
Diphcnytamiac
Methyl Ethyl Ketone
Ethyiene Onde
Ethylacetate
Vinyl Acetate
Ethyldichlonde
Phthalic Anhydride
Terephthalic Acid
Methyl Methaciylate
Dtchlorobenzene
86
Acetic Anhydride
Dimethyl Terephthalate
EthanoUminet
Acetone Cyanooydride
EthyMichtoride
Methyl Ethyl Ketooe
Acetic Anhydride
Ethyldichloride
Milk Anhydride
Ethylbenzene
Ethyldichloride
Dimethyl Terephthalate
Methyl MethacryUte
Acrybc Acid
Ethyldichloride
Acetic Anhydride
NUMBER OP
COLUMNS AND
OPERATING
CONDITIONS
1NV
IV
1NV
1NV
IV
1NV
1NV
ICO
1NV
1NV
2NV
IV
2NV
1NV
1NV
3V
ICO
IV
IV
ICO
IV
1NV
IV
1 NV
ICO
1NV
1NV
IV
1NV
1NV
IV
1NV
2V
IV
ICO
IV
1NV
1NV
1 NV
1NV
1NV
IV
1NV
IV
IV
1NV
ICO
1NV
IV
1NV
IV
1NV
ICO
2NV
IV
1NV
1NV
1NV
1NV
IV
1NV
4 CO
PLOWRATE
CSCTM)
0.005
0.007
0.012
0.013
0.02
0.02
0.02
0.02
0.063
0.1
0.1
0.1
0.1
0.18
0.2
02
026
0.3
0.4
0.48
OS
0.7
0.9
12
1.2
1-3
U9
1.39
1.45
U
1.5
1.7
1.8
1.8
1.94
2
22
23
23
23
2.4
2.4
2-5
2.6
2.6
33
3.66
42
23
4.4
4£
4.9
4.98
6
63
63
6.94
7
7.4
7.4
8.1
8.16
HEAT CONTENT
(BTU/SCF)
133
3752
374
755
3047
432
169
0
7
1056
834
360
36
207
2778
0
1375
4978
2224
1024
3602
680
1024
3643
1024
143
966
966
903
1225
352
1483
858
651
68
0
1183
1191
1012
781
1024
260
114
2870
62
90
1024
180
0
190
53
2003
1024
727
0
1286
727
0
439
0
91
1024
VOC FLOWRATE
(LB/HR)
0.004
0.11
0.025
0.034
0.29
0.031
0.02
0
0
0.4
0.25
0.2
02
0.08
2
0
1.83
4.9
4.9
1.53
11.5
0.4
14 I
15
3.81
3.4
6.04
6.04
1.6
10.4
1.8
13.6
4.9
8.1
0.8
0.003
10
13.8
6.4
5.2
38
4
1.9
41
13
28.8
11.61
5
0
4
3.9
3168
15.81
63.9
0
3
55
10
12
0
6.6
25.88
B-2
-------
TABLE B-l DISTILLATION EMISSION DATA PROFILE* (Continued)
PRODUCT
PROCESS
Dimethyl TerephthaUte
Dimethyl TerephthaUte
Vuiyi Acetate
Phthalic Anhydride
ChJorobenzene
DichJorobeazeoe
Chloroprene
Acrylonitrik
Vinyl Acetate
Chloroprene
Acetone
ElhyklichkHHk
Formaldehyde
Ethyldichlonde
Phthalic Anhydride
Acrylic Acid
Perchloroethytene
Dimethyl Terephthtltte
Vinyl Acetate
Dimethyl TerephthtUte
as
Dimethyl TerephthtUte
Phthalic Anhydride
Acetone
Methyl MethacryUte
EthanoUuninef
Ethylbenzene
Acrylic Acid
Acetone
Butadiene
Acrylic Acid
Aciylonitrik
Cyclohexanone/cyclohexaaol
ChJoroprene
Acrytom trite
Chlorobenzene
Phthalic Anhydride
Ethyl Acrytate
Acrylic Acid
Acetone Cyanohydrid*
Acrylic Ecten
Chlorobenzene
85
Acetone Cymnooydride
Confidential
ConfidentiaJ
Acetic Acid
Acetone
Dimethyl Terepbthalate
Methanol
CydohexanoM/cyclohenDOl
Methyl MethacryUte
Ad tponi trite
Ethytene Gtycol
Confidential
Dimethyl TerephthtUte
86
Hexamethytene Diamine
Alkyt Benzene
Methyl MethacryUte
NUMBER OF
COLUMNS AND
OPERATING
CONDmONS
1NV
2V
1NV
IV
IV
IV
IV
1NV
1 NV
2V
IV
1NV
2V
IV
IV
2V
1NV
1 NV
1 NV
2V
4 NV
1 NV
IV
1NV
1 V
3V
1 V
2V
1NV
1NV
IV
IV
3V
1NV
IV
IV
2V
2V
2V
1NV
3V
1 NV
7V
IV
3 CO
4 CO
3NV
1NV
2V
1NV
IV
IV
9V
6V
ICO
1 NV
1NV
7V
IV
IV
FLOWRATB
(SCFM)
8.4
8.9
9
9.5
9.9
9.9
10
10.2
10.5
11.0
1115
115
115
13
13.2
13.2
13.6
15
15
15
16.7
17.4
17.9
18
18.3
19.5
19.7
20
21.13
22J
22.6
2Z7
22.701
23.6
25.6
26.1
27
27.2
27.6
31.5
33.9
34.9
36.701
39.2
40.59
49.6
50
50.4
54.6
63.4
68.7
72.9
75
75.1
77 32
793
80
81.1
85.9
96.2
HEAT CONTENT
(BTU/SCF)
236
47
1308
690
177
177
3
379
74
30
0
727
9
183
979
8
6
236
149
47
1464
12S2
69
0
2870
0
0
0
2592
1453
92
439
18
0
346
346
505
69
400
1916
168
495
123
4
0
0
4
70
47
449
72
66
0
0
6
1453
9
0
104
295
VOC FLOWRATE
(LB/HR)
13
2.2
34.8
417
6
2
0.2
15.8
15.2
1.1
0
98.8
0.8
313
84.1
0.6
11
12
6.6
5
0.1
120.5
8 I
0
289
0
0
0
170.2
100.5
105
44
15
0
37.9
43.1
100
5.6
55.8
289
15.7
59
13.498
0.18
0.09
0.56
1.1
16.9
17
399.3
26.3
A* g
26.5
0
0
1-36
601
1 Q £
19.0
0
30.6
148.8
B-3
-------
TABLE B-2. DISTILLATION EMISSION DATA PROFILE1 (Continued)
PRODUCT
PROCESS
Ethyldichlonde
Acetone Cyanohydride
Dimethyl Terephthalatt
Methyl Methacrylate
CMoropreneMethyl
MethacryUte
Dimethyl Trephthalate
Methyl Methacrylate
Ethyl Acrylate
Dimethyl Terephthalate
Acetic Acid
Acrylic Acid
Ethyldichlonde
Methtno)
Acetic Acid
Isophthalk Acid
Acetaldehyde
84
NUMBER OF
COLUMNS AND
OPERATING
CONDITIONS
1NV
2V
1NV
2NV
3V
IV
2V
1NV
2V
1NV
1NV
1NV
1 NV
1NV
1NV
1NV
2NV
6NV
FLOWRATE
100
lOlJ
123.8
126.4
145
152
176
178J
219
281
358
364
535.5
560
575
637
647.3
656
HEAT CONTENT
(BTU/SCF)
6
4
768
155
12
13
47
1316
45
768
333
150
804
1258
380
19
293
6
VOC FLOWRATE
(LB/HR)
8J
U
628J
116J
7.2
9*
57
1300
454
1426
375
289
3050
3668
600
123
183
19
* Emiwoni data taken from Appendix C of DUtillation Operation! in Synthetic Ornnic Minuficrunni • Backiround Information
for Proooted Standards (EPA-450/3«-005a).
B-4
-------
APPENDIX C
COST CALCULATIONS
-------
APPENDIX C
COST CALCULATIONS
C.I SIZING CALCULATIONS FOR THERMAL INCINERATOR
Hand Calculations for the VENTCOST Program - Incineration Procedure
• Used to assess control equipment costs for the SOCMI CTG for
Reactor Process and Distillation Vents.
• Calculations based on OAQPS Control Cost Manual, Chapter 3.
• The stream costed in this example is model stream R-LFHH. Its
characteristics are as follows:
A.
VOC to be controlled
MW
Flow rate (total)
VOC flow rate
Heat value
Oxygen content
Inert content
Ethyl Chloride*
64.5 Ib/lb mole
3.839 scfm
8.4 Ib/hr
1,286 Btu/scf
0%
Assume all N2
*Most of the following calculations are based on the actual
compound in the SOCMI Profile. However, the combustion and
dilution air calculations are based on the design molecule
^2.85^5.700.63* which represents the average ratio of carbon,
hydrogen, and oxygen for streams in the SOCMI profile. The
molecular weight of this "design molecule" is 50 Ib/lb-mole.
Check to see if the stream to be controlled is halogenated--yes,
ethyl chloride contains chlorine. Since the stream is
halogenated, the following applies.
1. No heat recovery is allowed for halogenated streams.
2. A scrubber will be required to remove acidic vapors from
the flue gas following combustion. Scrubber sizing and
costing calculations for this vent stream immediately
follow the incinerator calculations (see Section C.2).
C-l
-------
B. Calculate total moles of the vent stream, and quantify moles of
VOC, 02 and inerts.
1. VOC moles only:
VOC moles - (8.4 lb/hr)(hr/60 min)(lb-mole/64.5 Ib)
* 0.0022 Ib-moles/min
2. Total vent stream moles:
Vent moles - (3.839 scfm)(lb-mole/392 scf)
- 0.0098 Ib-moles/min
3. Oxygen moles:
02 moles - 0
4. Inert moles:
Inert moles * Vent moles - VOC moles - 02 moles
= (0.0098 - 0.0022 - 0) Ib-mole/min
= 0.0076 Ib'mole/min
C. Calculation of Molar Ratio of Air to VOC
Please note that the combustion and dilution air calculations
are based on the design molecule C2.85H5.70o.63» which
represents the average ratio of carbon, hydrogen, and oxygen.
The molecular weight of this "design molecule" is 50 Ib/lb-mole.
Assume 3.96 moles of 02 are required for each VOC mole.
1. Since no oxygen is present in the stream, additional
combustion air must be added, to insure proper combustion.
2. Calculate the ratio of 02 to VOC required for combustion.
02 theory * 3.96 - 02 ratio already in stream*
*Additional air is not required if sufficient oxygen is
already present in the vent stream.
3. Since air is 21% 02 the necessary ratio of air to VOC is:
Air ratio - (3.96)/0.21 - 18.86 moles air/mole VOC
D. Calculation of molar ratios of inert moles to moles VOC
1, Inert ratio « inert moles/VOC moles
= 0.0076/0.0022
- 3.4545 moles inert/mole VOC
C-2
-------
E. In order to ensure sufficient 62 is present in the combustion
chamber, enough air must be added to provide 3% 03 in the
exhaust (flue) gas stream after combustion. The 62 material
balance is :
(Initial 02%}(vent stream) + (0.21)(dilution air) =
(0.03)(exhaust)
Initial 62% = 0; therefore,
(0.21)(Dilution air) - (0.03)(exhaust stream)
(0.21)(Dilution air) - (0.03)(dilution air + vent stream)*
*Assume no increase in moles after combustion
(0.21)(Dilution air) * (0.03)(dilution air) +
(0.03)(vent stream)
Dilution air = (0.03)7(0.21 - 0.03) (Vent stream flow)
*This factor will be used later.
F. Exhaust gas consists of noncombustibles (N2) + C02 + H20 (see
"Combustion Stoichiometry Memo")
1. Exhaust ratio - (0.79)(air ratio) + 2.85 + 2.85
=20.6 moles exhaust/mole VOC
2. Dilution ratio = 0.03/(0.21 - 0.03)
(Inert ratio + Exhaust ratio)
G. Calculate flows of stream components based on calculated ratios
1. Dilution ratio - Factor * (Inert ratio - Exhaust ratio)
- (0.1667)(3.4545 + 20.6)
= 4.009
2. Dilution air flow - (Dilution air ratio)(VOC moles)
(392 scf/lb-mole)
Dilution air flow - (4.009)(0.0022)(392)
=3.457 scfm
3. Combustion air flow - (Air ratio)(VOC moles)(392)
= (18.86)(0.0022)(392)
- 16.26 scfm
Combined air flow = Combustion air + Dilution air
- (16.26 + 3.4545)
- 19.7 scfm
C-3
-------
4. Inert gas flow = (Inert ratio)(VOC moles)(392)
= (3.4545)(0.0022)(392)
=2.98 scfm
5. Total flow « Combined air flow + Initial vent stream flow
+ Inert gas flow
- 19.7 + 3.839 scfm
New flow - 26.519 scfm
H. Recalculate heat value of the stream after adding air streams
(prior to combustion)
1. Heatval « (Initial flow * Initial heatval)/New flow
« (3.839 * 1.286J/26.519
« 186.2 Btu/scf
I. Check the heat value of the precombustion vent stream, to see if
it is acceptable from a safety perspective
1. Streams containing halogens must have a heat value
< 95 Btu/scf, nonhalogens < 98 Btu/scf.
186.2 > 95
2. Dilute stream to have a heat value < 95 Btu/scf.
Dilution air - [New flow * (Heatval - 95)]/95
- [26.5 * (186.2 - 95)]/95
- 25.5 scfm
Heatval « 95 Btu/scf
New flow = 26.5 + 25.5
=52.0 scfm
J. Minimum incinerator flow is 50 scfm. Streams less than 50 scfm
will be increased by addition of air.
52 scfm > 50 scfm
K. Establish temperature that incinerator operates:
Halogenated: 2,000°F
Nonhalogenated: 1,600°F
C-4
-------
L. Nonhalogenated streams are potential candidates for heat
recovery.
If addition of air flows results in lowering the heat value of
the entire vent stream below 13 Btu/scf («25% LEL), then the
entire vent stream is eligible for heat (energy) recovery in a
heat exchanger.
High heat value streams cannot be heated in a preheater because
of combustion/explosion concerns, but the VENTCOST program will
calculate economic options that allow preheating of the air
stream only.
The energy recovery equations are weighted to account for the
mass of the heated streams since the flows being preheated may
be smaller than the exhaust (flue) gas flows.
No calculations are presented here since the example stream is
halogenated, and, therefore, heat recovery is not allowed.
M. Calculate the auxiliary fuel (Qaf) requirement
Qaf • [0.0739 * new flow * [0.255 * (1.1 * incinerator
temperature - temperature gas - 0.1 * 77) -
(heatval/0.0739))] + [0.0408 * [21,502 -
(1.1 * .255 * (incinerator temperature - 77))]
-* Incinerator Temperature = 2,000 °F
*See OAQPS Control Cost Manual, Incinerator Chapter for
Derivation and Assumptions.
[.0739 * 52 * [.255 * (1.1 * 2,000 -
Qaf = 77 - 0.1 * 77) - (2097.0739)11
[0.0408 * [21,502 - (1.1 * .255 * (2,000 - 77)]]
Qaf - f.0739 * 52 * (-2288)1
855.27
Qaf = -10.3 scfm
Negative value indicates no auxiliary fuel is theoretically
needed. Therefore, set Qaf = 0.
N. Calculate sufficient auxiliary fuel to stabilize flame (5% of
TEI).
1. Thermal Energy Input (TEI) = 0.0739 * (new flow + Qaf) *
(0.255 * (incinerator
temperature - 77)
TEI - 0.0739 * (52 + 0) * 0.255 * (2,000 - 77)
= 1,884
C-5
-------
2. Qaf - (0.05 * 1,884)/(0.0408 * 21,502)
- 0.107 - 0.1 scfm
0. Calculate the total volumetric flow rate of gas through the
incinerator, Qf-j. Include auxiliary air for the natural gas.
1. Qfi - new flow + Qaf + combustion air for fuel
2. Assuming the fuel is methane, CH4, the combustion reaction
is:
CH4 + 202 - C02 - C02 + 2H20
So two moles of 0? are required for each mole of fuel.
Since air is 21% 02.
2/0.21 = 9.5 moles air/mole of fuel
Combustion air for fuel - (Qaf * 9.5)
3. Qfi - New flow + Qaf + (Qaf * 9.5)
* 52 + 0.107 + (0.107 * 9.5)
= 53 scfm
C.2 COST ANALYSIS - ESTIMATING INCINERATOR TOTAL CAPITAL INVESTMENT
A. The equipment cost algorithms are only good for the range of
500 scfm to 50,000 scfm. The minimum design size is 500 scfm,
so capital costs are based on 500 scfm, and annual operating
costs are based on calculated
1. Design Q = 500 scfm
For 0% heat recovery, equipment cost, EC, is:
EC = 10,294 * (Design QA-2355) * (# incinerators) *
(CE INDEX/340.1)
EC = 10,294 * (500A-2355) * \ * (355.6/340.1)
EC - $46,510.
Add duct cost. Based on an article in Chemical Engineering
(5/90) and assuming 1/8-in. carbon steel and 24-in. diameter
with two elbows per 100 feet.
Ductcost - [(210 * 24*0-839) + (2 * 4.52 * 24*1-43) *
(length/100) * (CE INDEX/352.4)]
Ductcost « $11,722.52 (for length of 300 ft)
C-6
-------
D. Add auxiliary collection fan cost, based on 1988 Richardson
manual.
Fancost = (96.96418 * Initial Q*0.5472) * 355.6/342.5
* 210.18
E. Total Equipment Cost, ECjoT* is given by:
ECjQT * EC + Ductcost + Fancost
= 46,510 + 11,723 + 210.18
- $58,443
F. Purchased Equipment Cost, PCE, is:
PCE - 1.18 * ECjQT
= $68,963
G. Estimate Total Capital Investment, TCI
if Design Q > 20,000, installation factor * 1.61
if Design Q < 20,000, installation factor = 1.25
TCI = 1.25 * PCE
= 1.25 * $68,963
= $86,203
C.3 CALCULATING ANNUAL COSTS FOR INCINERATORS
A. Operating labor including supervision (15%)
1. Assume operating labor rate - $15.64/hr (1/2 hour per
shift)
Op labor = (0.5 * Op hours)/8 * ($15.64/hr)(1.15)
(Op hours = 8,760)
Op labor = $9,847.34/yr
B. Maintenance labor and materials
M labor - (0.5/8 * 8,760) * ($17.21/hr)
- $9,422.48
Materials = M labor = $9,422.48
C. Utilities *= Natural Gas & Electrical Costs
Assume value of natural gas = $3.30/1,000 scf
1. Natural gas - (3.30/1,000) * Qaf * 60 min/hr * Op hours
Natural gas = (3.30/1,000) * 0.107 scfm * 60 * 8,760
= $186/yr
2. Power = (1.17 * 10A'4 * Qfi * 4)/0.60
Power = (1.17 * 10'4 * 53 * 4)/0.60
= 0.0413 kW
C-7
-------
3. ElecCost - (0.061 $/kWh) * (0.0413) * (8,760)
- $22.07
D. Calculate total direct costs, TDC
TDC = Op_Labor + M_Labor + Material + NatGas + ElecCost
- (9,847 + 9,422 + 9,422 + 186 + 22.07)
- $28,899/yr
E. Overhead - 0.60 * (Op_Labor + M_Labor + Material)
- $17,214.6/yr
F. Administrative - 2% of TCI
Admin - (0.02)(86,203)
- $l,724/yr
G.
H.
Tax = 1% of TCI
Tax - $862/yr
Insurance * 1% of TCI
Ins = 0.01 * TCI
= $862/yr
I. Annualized Capital Recovery Costs, Anncap, is:
AnnCap <= 0.16275 * $86,203
= $14,029.54/yr
J. Total Indirect Capital Cost, 1C, is:
1C = overhead + administrative + tax + insurance + Anncap
= (17,215 + 1,724 + 862 + 862 + 14,029) $/yr
= 34,692 $/yr
K. Total Annual Cost, TAC, is:
TAC = 1C + DC
- 34,692 + 28,899
= 63,591 $/yr
C.4 SIZING CALCULATIONS FOR SCRUBBER
Hand Calculations for the Ventcost Program Scrubber Procedure
• Stream to be costed is R-LFHH as it exists after combustion in
incinerator
C-8
-------
Calculate stream parameters after combustion. Assume 98 percent
VOC destruction
-»• Ethyl chloride is the VOC in stream R-LFHH. There is one
mole of Cl for every mole of VOC. Therefore, for every
mole of VOC destroyed, one mole of HC1 is created.
VOC destroyed = (initial VOC flow-lb/hr)(0.98) - VOC MW
- (8.4 lb/hr)(0.98)/(64.5 Ib/lb-mole)
• 0.13 Ib-mole/hr
HC1 created =0.13 Ib-mole/hr
HC1 (Ib/hr) = (0.13 lb.mole/hr)(36.5 Ib/lb-mole)
= 4.66 Ib/hr
Calculate inlet halogen concentration
HC1 (scfm) = (4.66 lb/hr)(lb-mole/36.5 Ib) * 392 scf/lb-mole *
1 hr/60 min
* 0.83 scfm/min
HC1 (ppm) = (0.83 scfm)/Qfi * 10A6
= (0.83/53) * 10*6
= 15,660 ppm (inlet concentration)
The halogen is chlorine, therefore
Molecular weight (Hal_MW) - 35.5
Slope of operating curve (slope) = 0.10
Schmidt No. for HC1 in air (SCG) = 0.809
Schmidt No. for HC1 in water (SCL) = 381.0
Calculate the solvent flow rate.
New flow = 53 scfm
Gas moles - (53 scfm)(.075 lb/ft3)(lb-mole/29 lb)(60 min/hr)
- (53)(0.155)
= 8.22 Ib-mole/hr
Assume L/g = 17 gpm/1,000 scfm
Convert to unitless ratio
L/G = 17 * (8.34 * 60)/[(1,000/392) * 60 * 29] = 1.916
C-9
-------
Absorption factor (AF) = (L/G)/slope
AF = 1.916/0.1
AF = 19.16
Liquid moles = (slope of operating curve) (adsorption factor AF)
(gas moles)
= 15.75 Ib-mole/hr
Liquid flow (gal/min) = (15.75 lb-mole/hr)(18 Ib/lb-mole)/
(62.43 Ib/ft3)/60 min/hr * 7.48 gal/ft3
Liquid flow = 0.57 gal/min
Liquid flow (Ib/hr) = (0.57 gal/min)(8,34 1b/gal)(60 min/hr)
= 283.3 Ib/hr
Calculate Column Diameter
Density of air = 0.0739 lb/ft3 (from ideal gas law)
Density of liquid = 62.2 lb/ft3
MW of gas stream = MW HCL x Volume Fraction + MW Air x Volume
Fraction
MW stream = 36.5 * (15,660/10*6) + 29 * [(10A6-15,880)/10A6]
= 36.5 * 0.0157 + 29 * 0.98434
= 29.12 Ib/lb-mole
-» Column diameter based on correlation for flooding rate in
randomly packed towers (see HAP manual)
ABSCISSA = (liquid lb/hr)/(gas Ib/hr) *
(density of gas/density ot liquid)*0-^
ABS - [283.3/[8.22 * 29)] * (0. 0739/62. 2)A°-5
ABS = 0.0410
ORD = 0.9809237 * (ABS)A(-0. 0065226 * log [ABS]) +
(ABS)A(-0. 021897)
= 0.9809237*(0.0410)A(-0. 0065226 * log[0.0410]) +
(0.0410)A(-0. 012897)
ORD - 0.15
Calculate G_Area (Ib/ft^.sec) based on column cross sectional
area at flooding conditions.
G_Area = F * (ORD * density of gas * density of liquid *
32.2/69.1 * 0.85A0.2)A0.5
= 0.6 * (0.15 * 0.0739 * 62.2 * 32.2/69.1 * 0.85A0.2)A°-5
= 0.34
C-10
-------
Calculate the Area of the Column
Area of column = (MW stream * gas moles)/ (3, 600 * G_Area)
Area (ft?) = (29.12 * 8.22)7(3,600 * 0.34)
Area (ft2) = 0.19 ft2 •
Calculate Diameter of Column
D_col = [(4//7) Area]A°-5
- 1.27 (Area)A0-5
= 0.5 ft
Calculate liquid flux rate
LL (Ib/hr-ft2) = (liquid flow lb/hr)/Area
LL = (283.3)/(0.19)
= 1,491
Calculate the number of gas transfer units (NOG) (Assume 98%
removal efficiency)
NOG - In [(Hal concentration/(0.02 * Hal concentration)) *
(1-U/AF)) + (1/AF)]/(1-(1/AF))]
= In [(15,660/(0.02 * 15,660))* (1-1/19.16) +
NOG = 4.07
Calculate the height of the overall gas transfer unit (HOG)
using:
HOG = Hg + (1/AF) HL
where
HQ = Height of a single gas transfer unit (ft)
H|_ = Height of a liquid transfer unit (ft)
Based on generalized correlations:
HQ = [b * (3,600 * G_Area)Ac/(LLAd)](SCG)A°-5
H|_ = Y * (LL/liquid viscosity)AS * (SCL)A°-5 assuming 2-in.
ceramic raschig rings for packing
b = 3.82
c = 0.41
d = 0.45
C-ll
-------
s = 0.22
Y = 0.0125
-* To convert from centipoise to Ib/hr * ft2
Liquid viscosity = 0.85 * 2.42
9 = 11.13
r = 0.00295
Therefore,
HG = [3.82 * (3,600 * 0.34)A0-41/U,491A0-45)] * SCGA0-5
= 2.63 x 0.809A°-5 = 2.37
HL = (0.0125) * (1,491/2.05)A0-22 * SCLA°-5
= 0.051 * 381A°-5 = 1.0
Solving for HOG:
HOG = HG + (1/AF) * HL
= 2.37 + (1/19.16) * 1.0
= 2.42
Calculate the height of the packed column from HOG and NOG.
Allow for 2 ft of freeboard above and below the packing for gas
disentanglement, and additional height based on column.
Height (Ht) = (NOG)(HOG) + 2 + 0.25 * Diam. Col
= (4.07)(2.42) + 2 + 0.25 * 0.5
= 12 ft
Calculate Volume of Packing
Volume = (/7/4) * (D)2 * (NOG * HOG)
= (/7/4) * (.5)2 * (4.07 * 2.42)
= 1.93 ft3
Calculate Volume of Column
Volume = (77/4)(Diam col)2 x Ht
= (0.785)(0.5)A2 x 12
= 2.36 ft3
Calculate Pressure Drop
DelPa = (g x 10'8) * [10A(r * LL/liquid density)] *
[(3,600 * G_Area)A2]/gas density
C-12
-------
• DelPa - (11.13 x 10-8) * (10^(0.00295 * 1,491/62.2)) *
((3600 * 0.34)A2)/o.Q739
Del Pa - 2.66
Del Ptot « Del Pa * (NOG + HOG)/5.2
- 2.66 * (4.07 * 2.42J/5.2
- 5.09
C.5 COST ANALYSIS-ESTIMATING SCRUBBER TOTAL CAPITAL INVESTMENT
• Total Cost of Tower 1s:
wt - (48 * Diam * ht) + 39 * D1am2
- (48 * 0.5 * 12) + 39 * (0.5)2
wt - 297.8 Ibs
TCost - [1.900604 * (wt/1,000)A0.93839] * 1,000 * (355.6/298.2)
TCost « [1.900604 * (297.8/1,000)A0.93839] * 1,000 *
(355.6/298.2)
- 727
• Cost of Packing
Packcost - Volume of packing * 20
- 1.93 * 20
- 38.6
• Assume Cost of Duct Work and Fan
Duct cost - 3,907.5
Fan cost - 488.9
• Calculate Platform Cost. For columns less than 3 ft in diameter
design diam (DO) « 3.
Platform Cost - 10A(0.78884 * In (diam) + 3.325) * (355.6/298.2)
- 10A(0.7884 * In (0.5) + 3.325) * (355.6/298.2)
* 715.6
• Assume Stackcost - 5,000
• Calculate Total Capital Investment (TCI)
TCI - (towercost + packcost + ductcost + fancost +
platform cost + stackcost) * 1.18 * 2.2
C-13
-------
TCI - (727 + 38.6 + 3,907 + 488.9 + 715.6 + 5,000) *
1.18 * 2.2
= $28,237
C.6 CALCULATING ANNUAL COSTS FOR SCRUBBERS
• Calculate Water Costs
Water - (liquid flow lb/hr)/8.34 Ib/gal * price per 1,000 gal *
8,760 hr/yr
Water - (283.4)/(8.34) * 0.22/1,000 * 8,760
Water - 65.49
• Calculate Electrical Costs Based on Pressure Drop
Elec - 0.0002 * new flow * DelPtot * 8,760 * elec_cost $/KW-Hr
- 0.0002 * 53 * 5.09 * 8,760 * 0.061
= 29 $/yr
• Calculate Cost of Labor, Supervision, Maintenance
Op labor - (1/2 hour per 8 hour shift ) *
(Annual operating hours) * (Op labor rate)
Op labor - 0.5/8 * 8,760 * 15.64
Op labor = 8,563 $/yr
Supervision = 0.15 * Op_Labor
Supervision - 0.15 * 8,563 = 1,284.44
Maintenance labor = 0.5/8 * 8,760 * 17.21
Maintenance labor = 9,422.48 $/yr
Maintenance materials - 9,428.48 $/yr
• Calculate Direct Operating Costs
Dir Op Cost » Water + electric + opjlabor + supervision +
main labor + maintenance materials
Dir Op Cost = 65.49 + 29 + 8,563 + 1,284.44 +
9,422.5 + 9,422.5
Dir Op Cost * 28,786 $/yr
C-14
-------
• Calculate cost of overhead, tax, insurance, administrative, and
capital recovery costs
Tax = 0.01 * TCI * 282.4
Insurance - 0.01 * TCI - 282.4
Administrative - 0.02 * TCI « 564.7
CRC - 0.16275 * TCI - 4,596
Overhead - 0.6 * (op_labor + supervision +
main_La + maint)
Overhead - 17,215
• Calculate indirect operating costs
Ind Op Cost = Overhead + Tax + Insurance + Administrative + CRC
= 17,215.44 + 282.4 + 282.4 + 564.7 + 4,596
= 22,940
• Annual Operating Cost, Anncost
Anncost = 28,786 + 22,940
Anncost = 51,726 $/yr
C.7 SIZING CALCULATIONS FOR FLARES
Hand Calculations for the VENTCOST Program - Flare Procedure
• Used to assess control equipment cost for the SOCMI CTG
• Calculations based on OAQPS Control Cost Manual, Chapter 7.
• The stream costed in this example is model stream D-HFLH. Its
characteristics are the following:
VOC to be controlled
MW
Flow rate (total)
VOC flow rate
Heat value
Oxygen content
Isophthalic acid
166 Ib/lb mole
632.401 scfm
6.15 Ib/hr
19 Btu/scf
0%
A. Flare tip diameter is generally sized on a velocity basis.
Flare tip sizing is governed by EPA rules defined in the
Federal Register. For flares with a heat value less than
300 Btu/scf the maximum velocity is 60 ft/sec.
1. The net heating value of vent stream * 19 Btu/scf
C-15
-------
2. Thus maximum velocity (Vmax), = 60 ft/sec. (It is standard
practice to size flares at 80 percent of
3. Calculate the heat released by combustion of the vent
stream
Heatrel (Btu/hr) - Vent Flow * heat value * 60 min/hr
- 632,401 scfm * 19 Btu/scf * 60
- 720,937 Btu/hr
4. Flare height (ft) is determined using Equation 7-3 in OAQPS
SOCMI flares chapter.
Height - (TFOyr/j-k)0-5
where
T = Fraction of heat intensity transmitted
F = Fraction of heat radiated
Q = Heat release (Btu/hr) - 720,937 Btu/hr
k = allowable radiation, (500 Btu/hr-ft2)
Assuming (a) no wind effects, (b) center of radiation at
the base of the flare, and (c) thermal radiation limited at
base of the flare.
T * 1
F = 0.2
k - 500
Substituting and simplifying,
Height = ((heatrel)°-5)-/177.24
(Note that this assumes allowable radiation =
500 Btu/hr- ft?)
Height - 4.79 ft
The minimum flare height is 30 ft. Therefore,
Height - 30 ft
C-16
-------
Calculate the auxiliary fuel flow required to sustain a
stable flame. A minimum heat value of 300 Btu/scf is
required by 40 CFR, Section 60.18. Therefore, the
auxiliary fuel flow, Qaf (scfm) is:
Qaf - Vent flow * (300 - heat value)/(1000-300)
- 632 * (300-19)/(1000-300)
- 253.70 scfm
Calculate total stream flow, Qjot (scfm):
Qtot " Vent flow + Qaf
- 632 + 253.7
- 886 scfm
7. Calculate minimum flare tip diameter, D, (in.) by
D = 12[4/ir * (Qtot/60)/0 8 VMAX]°-5
= 12[4//7 * (886/60)]°-5
= 12(0.392)0.5
- 7.51 in.
Since the calculated diameter is rounded up to the next
commercially available size, available in 2-in. increments,
the diameter would be D » 8 in.
B. Purge Gas Requirement - Purge gas is used to maintain a minimum
required constant flow through the system. Using the
conservative value of 0.04 ft/sec (gas velocity) and knowing the
flare diameter, the annual P volume can be calculated.
1. P(scfm/yr) - (0.04) * ((/7)/4) * (D2)/144 * 60
= 0.006 scfm
C. Pilot Gas Requirement
1. Since the number of pilot burners (n) is based on flare
size (flare diameter 1 to 10 in. - 1 pilot burner) this
stream would require 1 burner (our flare tip is 8 in.)
2. Pilot gas flow (fp)
Fp - (70 scf/hr) * N * (hr/60 min)
- 1.167 scfm
D. Steam Requirement
The steam requirement depends on the composition of the vent gas
being flared, the steam velocity from the injection nozzle, and
the flare tip diameter.
C-17
-------
1. The steam requirement can be calculated based on steam -
C02 weight ratio of 0.68 (see Equation 7-7, OCCM flares
chapter).
Wsteam = flow * (0.075 * 60) * 0.4
= 632 * (0.075 * 60) * 0.4
= 1,137 Ib/hr
Knockout Drum
The dropout velocity, U, of a particle in a stream, or the
maximum design vapor velocity, is calculated by:
1. U = K x ((P1 - Pv)/pv)0-5 ft/sec
where
k = design vapor velocity factor = .2 assumed as
representative of the k range of 0.15 to 0.25
P-| = 37 = liquid density, assumed
Pv = 0.1125 vapor density, assumed
U = 3.62
The maximum vessel cross-sectional area, A, can be calculated
by:
A = Q (ft3/min)/(60 x U (ft/sec), ft?
Q = 632 scfm
A = 632/(60 x 3.62)
A = 2.91
Calculate vessel diameter
1. The vessel diameter, dm-jn, is calculated by:
dmin - 12 (in/ft) x (4 x A (ft2)/,7)0.5, in.
dmin = 12 x (4 x 2.91//r)0.5
dmin = 23.1 in.
2. In accordance with standard head sizes, drum diameters in
6-in. increments are assumed so:
d = dm-jn to the next largest 6 in.
d = 24 in.
C-18
-------
3. The vessel height, h, is determined by:
h = 3 x d, in.
h = 3 x 24 = 72 in.
C.8 COST ANALYSIS - ESTIMATING TOTAL CAPITAL INVESTMENT FOR FLARES
(*Assuming March 1990 Dollars)
A. Flare costs (Cf) are calculated as a function of stack height,
H (ft) and tip diameter, D, (in), and are based on support type.
Derrick support group was not considered since the stack height
is < 100 ft.
1. Self Support Group
Cf = [78 + 9.14 (D) + .75 (H)]2
Cf = [78 + 9.14 (8) + .75 (30)]2
Cf = 30,144
2. Guy Support Group:
Cf = [103.17 + 8.68(8) + .47 (30)]2
Cf = 34,861
Since Self Support is < Guy Support, the cheaper is chosen.
B. Cost for 100 ft of transfer and header pipe, Cp, assuming
400 length needed.
Cp = (127.4 x D-) x 4
Cp = (127.4 x Si-*2*) x 4
Cp = 5,243
C. Cost for knockout drum, C^, is a function of drum diameter,
d (ft) and height (ft)
Cfc = 14.2 x [d x t x (h + 0.0812 x d)]0-737
where
t = vessel thickness (in.)
C-19
-------
vessel thickness is determined based on drum diameter. Since
Drum diameter, d - 24 in. - 2.0 ft and
Drum height, h - 90 1n. - 7.5 ft,
Drum thickness, t • 0.25 in.
C|< - 14.2 x [24 x 0.25 x (90 + 0.0812 x 24)]°-737
Ck - 1,484
D. Collection Fan Cost
Cfan • (96.96418 x 632 scfm°- 547 1969) x 355.6/342.5
- 3,431
Collection Fan Cost based on 1988 Richardson Manual; see Chris
Bagley's March 9, 1990, calculation placed in the polystyrene
file.
E. Flare system equipment cost, EC, is the total of the calculated
flare, knockout drum, manifold piping, and collection fan cost.
EC - [Cf + Ck + Cp) * 355.6/354.6] + Cfan
Ec - [30,144 + 1,484 + 5,243) * 355.6/354.6] + 3,431
EC - 41,712
F. Purchased equipment cost, PEC, is equal to equipment cost, EC,
plus factors for instrumentation (.10), sales taxes (0.03), and
freight (0.05) or
PEC - EC x (1 + 0.10 + 0.03 + 0.05)
PEC - 1.18 x 41,712
PEC - 49,220
6. Installation Costs: The total capital investment, TCI, is
obtained by multiplying the purchased equipment costs, PEC, by
an installation factor of 1.92
TCI - 1.92 x PEC
TCI - 1.92 x 48,916
TCI - 94,502
C-20
-------
C.9 CALCULATING ANNUAL COST FOR FLARES
A. Direct Annual Cost
1. Total natural gas cost} Cf, to operate a flare system
includes pilot, Cp, auxiliary fuel, Ca, and purge cost Cpu:
Cf - Cp + Ca + Cpu
where Cp is equal to the annual volume of pilot gas, fp,
multiplied by the cost per scf
Cn ($/yr) - Flow * 60 * 8,760
- fp (scf/yr) x ($/scf)
Assume price of natural gas - 3.30 $/Mscf
Cp = 1.167 scfm * 60 * 8,760 x (3.30 $/Mscf)
Cp - $2,024/yr
2. Annual Purge gas cost CDU - 247.68 x D^ (Mscf/yr) *
(3.3 $/Mscf)
Annual Cpu « $817.3/yr
3. Auxiliary Gas Cost Ca
133,350 Mscf/yr x 3.3 $/Mscf - $440,055/yr
4. Cf = 2,024 + 817.3 + 440,055 - $442,896/yr
B. Calculate Steam Cost (Cs) required to eliminate smoking
Cs ($/yr) - 8,760 (hr/yr) x steam use (Ib/hr) x ($/lb)
Cs = 8,760 x 1,137 x 4.65 x 10"3
Cs - $46,315
C. Calculate operating labor cost, based on 630 manhours/yr
Operator labor - 0.5/8 * 8,760 * $15.64 « 8,562
Supervisor labor 8,572 x .15 - 1.286
Total labor - 9,848
D. Maintenance labor cost and materials
Maintenance labor ($/yr) - (1/2 hr/8 hrs shift) x 8,760 hr/yr x
$17.21/hr - $9,422/yr
Materials assumed equal to maintenance labor - $9,422/yr
C-21
-------
E. Overhead Cost
= 0.60 x (op labor + supervisor + labor + materials)
= 0.60 x (8,572 + 1,286 + 9,422 + 9,422)
= 17,221
F. Capital Recovery Factor: Assume 15 year life and 10% interest
so CRF = 0.1314
Capital recovery cost = 0.1314 x TCI
= 0.1314 x 94,502
= $12,418
G. General and Administrative, Taxes, and Insurance Costs
Assume 4% of total capital investment
4% of 94,502
= 3,780
H. Utilities — Power consumption based on actual minimum flow
Pressure drop = [1.238 * 10'6 * flow - (1.15 * 10'4)] *
length of pipe
= [1.238 * It)'5 * 632 - 1.15 * 10'4] * 400
= 0.27 in. H20
Power = (1.17 * 1(H * flow * pressure drop)/0.6
= [1.17 * 10'4 * 632 * 0.27)/0.6
= 0.03 kW
I. Elec cost = Power x op hours x elec price ($/1000 kW-hrs)
= (0.03)(8,760)(0.061)
= 16.03
J. Calculating total Annual Costs (Indirect and Direct)
1. Direct Annual Cost
Direct Cost = Cost electricity + materials +
maintenance labor + supervisors +
operation labor + steam cost + fuel cost
Direct cost = 16.03 + 9,422 + 9,422 + 1,286 + 8,562 +
46,315 + 443,162
= 518,383
C-22
-------
2. Indirect Annual Cost
IAC = general + capital recovery cost + overhead
IAC = 3,757 + 12,341 + 17,221
IAC = 33,320
K. Annual Cost = Direct cost + Indirect Cost
= 518,383 + 33,320
= 551,702
C-23
-------
APPENDIX D
SYNTHETIC ORGANIC CHEMICAL MANUFACTURING INDUSTRY
CONTROL TECHNIQUES GUIDELINE EXAMPLE RULE
-------
EXAMPLE ONLY
APPENDIX D
SYNTHETIC ORGANIC CHEMICAL MANUFACTURING INDUSTRY
CONTROL TECHNIQUES GUIDELINE EXAMPLE RULE
D.I INTRODUCTION
This appendix presents an example rule limiting volatile organic
compound (VOC) emissions from reactor processes and distillation
operations. The example rule is for informational purposes only and, as
such, is not legally binding. The purpose of the example rule is to
provide a model containing information on the sections and typical issues
that need to be considered in writing a rule to ensure clarity and
enforceability of the standards.
Two points concerning implementation of the recommended reasonably
available control technology (RACT) in Chapter 6.0 warrant consideration
in drafting a regulation. First, Chapter 6.0 recommended that any reactor
process or distillation vent stream for which an existing combustion
device is employed to control VOC emissions should not be required to meet
the 98 percent destruction or 20 parts per million by volume emissions
limit until the combustion device is replaced for other reasons. Second,
Chapter 6.0 recommended that the total resource effectiveness index limit
be applied on an individual process vent stream basis for a given process
unit.
An additional point warranting consideration when drafting a
regulation pertains to the reporting requirements. Section 7.8 stated
that reporting frequency is left to the discretion of State air quality
management agencies; however, this model rule provides example
D-l
-------
EXAMPLE ONLY
requirements to make the example rule more complete. These requirements
may also be revised by the State agencies.
The remainder of this appendix constitutes the example rule.
Sections are provided on the following rule elements: applicability,
definitions, control requirements, performance testing, monitoring
requirements, and reporting/recordkeeping requirements.
D.2 APPLICABILITY
(a) The provisions of this rule apply to any vent stream originating
from a process unit in which a reactor process or distillation operation
is located. A decision tree is provided (Figure D.I) to facilitate
determination of applicability to this guideline on a per vent basis.
(b) Exemptions from the provisions of this guideline are as follows:
(1) Any reactor process or distillation operation that is designed
and operated in a batch mode is not subject to the provisions of this
rule.
(2) Any reactor process or distillation operation that is part of a
polymer manufacturing operation is not subject to the provisions of this
guideline.
(3) Any reactor process or distillation operation operating in a
process unit with a total design capacity of less than 1 gigagram per year
for all chemicals produced within that unit is not subject to the
provisions of this guideline except for the reporting and recordkeeping
requirements listed in D.7(e).
(4) Any vent stream for a reactor process or distillation operation
with a flow rate less than 0.0085 standard cubic meter per minute or a
total VOC concentration less than 500 parts per million by volume is not
subject to the provisions of this guideline except for the performance
testing requirement listed in D.5(c)(2), D.5(i) and the reporting and
recordkeeping requirements listed in D.7(d).
D-2
-------
EXAMPLE ONLY
NA
SOCMI
VOC Sources?
(Produces One or More
Chemicals in
Appendix
A)
Is the
Vent Controlled
Via Combustion
Does the
Process Unit Produce
Over 1 Gg/yr
Vent Flow
Over 0.0085 scmm ?
Vent Total
VOC Concentration
Over 500 ppmv?
i nc s i t "' — ~ —
Y
i • I. i .
98% Reduction [20 ppm Flares
1 i i i •
i
Monitoring
* <
Repc
Figure D.I. Synthetic organic chemical manufacturing industry
reactor/distillation control techniques guideline
logic diagram per vent.
D-3
-------
EXAMPLE ONLY
D.3 DEFINITIONS
Batch mode means a noncontinuous operation or process in which a
discrete quantity or batch of feed is charged into a process unit and
distilled or reacted at one time.
Boiler means any enclosed combustion device that extracts useful
energy in the form of steam.
By compound means by individual stream components, not carbon
equivalents.
Continuous recorder means a data recording device recording an
instantaneous data value at least once every 15 minutes.
Distillation operation means an operation separating one or more feed
stream(s) into two or more exit stream(s), each exit stream having
component concentrations different from those in the feed stream(s). The
separation is achieved by the redistribution of the components between the
liquid and vapor-phase as they approach equilibrium within the
distillation unit.
Distillation unit means a device or vessel in which distillation
operations occur, including all associated internals (such as trays or
packing) and accessories (such as reboiler, condenser, vacuum pump, stream
jet, etc.), plus any associated recovery system.
Flame zone means the portion of the combustion chamber in a boiler
occupied by the flame envelope.
Flow indicator means a device that indicates whether gas flow is
present in a vent stream.
Haloqenated vent stream means any vent stream determined to have a
total concentration of halogen atoms (by volume) contained in organic
compounds of 200 parts per million by volume or greater determined by
Method 18 of 40 CFR 60, Appendix A, or other test or data validated by
Method 301 of 40 CFR 63, Appendix A, or by engineering assessment or
process knowledge that no halogenated organic compounds are present. For
example, 150 parts per million by volume of ethylene dichloride would
contain 300 parts per million by volume of total halogen atoms.
Incinerator means any enclosed combustion device that is used for
destroying organic compounds. Auxiliary fuel may be used to heat waste
D-4
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EXAMPLE ONLY
gas to combustion temperatures. Any energy recovery section present is
not physically formed into one section; rather, the energy recovery system
is a separate section following the combustion section and the two are
joined by ducting or connections that carry fuel gas.
Primary fuel means the fuel that provides the principal heat input to
the device. To be considered primary, the fuel must be able to sustain
operation without the addition of other fuels.
Process heater means a device that transfers heat liberated by
burning fuel to fluids contained in tubes, including all fluids except
water that is heated to produce steam.
Process unit means equipment assembled and connected by pipes or
ducts to produce, as intermediates or final products, one or more SOCHI
chemicals (see Appendix A of this document). A process unit can operate
independently if supplied with sufficient feed or raw materials and
sufficient product storage facilities.
Product means any compound or SOCMI chemical (see Appendix A of this
document) that is produced as that chemical for sale as a product,
by-product, co-product, or intermediate or for use in the production of
other chemicals or compounds.
Reactor processes mean unit operations in which one or more
chemicals, or reactants other than air, are combined or decomposed in such
a way that their molecular structures are altered and one or more new
organic compounds are formed.
Recovery device means an individual unit of equipment, such as an
adsorber, carbon adsorber, or condenser, capable of and used for the
purpose of recovering chemicals for use, reuse, or sale.
Recovery system means an individual recovery device or series of such
devices applied to the same vent stream.
Total organic compounds or "TOC" means those compounds measured
according to the procedures of Method 18 of 40 CFR 60, Appendix A. For
the purposes of measuring molar composition as required in D.5(c)(4);
hourly emissions rate as required in D.5(e)(4) and D.4(b); and TOC
concentration as required in D.7(a)(4) and D.7(b). The definition of TOC
excludes those compounds that the Administrator designates as having
D-5
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EXAMPLE ONLY
negligible photochemical reactivity. The Administrator has designated the
following organic compounds as negligibly reactive: methane; ethane;
1,1,1-trichloroethane; methylene chloride, trichlorofluoromethane;
dichlorodif1uoromethane; chlorodif1uoromethane; tri f1uoromethane;
trichlorotrifluoroethane; dichlorotetrafluoroethane; and
chloropentaf1uoroethane.
Total resource effectiveness index value or "TRE index value" means a
measure of the supplemental total resource requirement per unit reduction
of organic hazardous air pollutants associated with a process vent stream,
based on vent stream flow rate, emission rate of volatile organic
compound, net heating value, and corrosion properties (whether or not the
vent stream contains halogenated compounds) as quantified by the given
equations. The TRE index is a decision tool used to determined if the
annual cost of controlling a given vent gas stream is acceptable when
considering the emissions reduction achieved.
Vent stream means any gas stream discharge directly from a
distillation operation or reactor process to the atmosphere or indirectly
to the atmosphere after diversion through other process equipment. The
vent stream excludes relief valve discharges and equipment leaks
including, but not limited to, pumps, compressors, and valves.
D.4 CONTROL REQUIREMENTS
(a) For individual vent streams within a process unit with a TRE
index value less than or equal to 1.0, the owner or operator shall comply
with paragraphs (1) or (2) of this section.
(1) Reduce emission of TOC (less methane and ethane) by
98 weight-percent, or to 20 parts per million by volume, on a dry basis
corrected to 3 percent oxygen, whichever is less stringent. If a boiler
or process heater is used to comply with this paragraph, then the vent
stream shall be introduced into the flame zone of the boiler or process
heater.
(2) Combust emissions in a flare. Flares used to comply with this
paragraph shall comply with the requirements of 40 CFR 60.18. The flare
operation requirement does not apply if a process, not subject to this
CTG, vents an emergency relief discharge into a common flare header and
D-6
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EXAMPLE ONLY
causes the flare servicing the process subject to this CTG to be out of
compliance with one or more of the provisions of the flare operation rule.
(b) For each individual vent streams within a process unit with a
TRE index value greater than 1.0, the owner or operator shall maintain
vent stream parameters that result in a calculated total resource
effectiveness greater than 1.0 without the use of a volatile organic
compound control device. The TRE index shall be calculated at the outlet
of the final recovery device.
D.5 TOTAL RESOURCE EFFECTIVENESS DETERMINATION, PERFORMANCE TESTING, AND
EXEMPTION TESTING
(a) For the purpose of demonstrating compliance with the TRE index
value in D.4(b), engineering assessment may be used to determine process
vent stream flow rate, net heating value, and TOC emission rate for the
representative operating condition expected to yield the lowest TRE index
value.
(1) If the TRE value calculated using such engineering assessment
and the TRE equation in paragraph D.5(f)(l) is greater than 4.0, then it
is not recommended that the owner or operator perform the measures
specified in Section D.5(e).
(2) If the TRE value calculated using such engineering assessment
and the TRE equation in paragraph D.5(f)(l) is less than or equal to 4.0,
then it is recommended that the owner or operator perform the measurements
specified in Section D.5(e).
(3) Engineering assessment includes, but is not limited to, the
following:
(i) Previous test results proved the test are representative of
current operating practices at the process unit.
(ii) Bench-scale or pilot-scale test data representative of the
process under representative operating conditions.
(iii) Maximum flow rate specified or implied within a permit limit
applicable to the process vent.
(iv) Design analysis based on accepted chemical engineering
principles, measurable process parameters, or physical or chemical laws or
D-7
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EXAMPLE ONLY
properties. Examples for analytical methods include, but are not limited
to:
(A) Use of material balances based on process stoichiometry to
estimate maximum VOC concentrations.
(B) Estimation of maximum flow rate based on physical equipment
design such as pump or blower capacities.
(C) Estimation of TOC concentrations based on saturation conditions.
(D) Estimation of maximum expected net heating value based on the
stream concentration of each organic compound, or, alternatively, as if
all TOC in the stream were the compound with the highest heating value.
(v) All data, assumptions, and procedures used in the engineering
assessment shall be documented.
(b) For the purpose of demonstrating compliance with the control
requirements of this rule, the process unit shall be run at representative
operating conditions and flow rates during any performance test.
(c) The following methods in 40 CFR 60, Appendix A, shall be used to
demonstrate compliance with the emission limit or percent reduction
efficiency requirement listed in D.4(a)(l).
(1) Method 1 or 1A, as appropriate, for selection of the sampling
sites. The control device inlet sampling site for determination of vent
stream molar composition or TOC (less methane and ethane) reduction
efficiency shall be located after the last recovery device but prior to
the inlet of the control device, prior to any dilution of the process vent
stream, and prior to release to the atmosphere.
(2) Method 2, 2A, 2C, or 2D, as appropriate, for determination of
gas stream volumetric flow rate.
(3) The emission rate correction factor, integrated sampling, and
analysis procedure of Method 3 shall be used to determine the oxygen
concentration (% 0£d) for the purpose of determining compliance with the
20 parts per million by volume limit. The sampling site shall be the same
as that of the TOC samples, and samples shall be taken during the same
D-8
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EXAMPLE ONLY
time that the TOC samples are taken. The TOC concentration corrected to
3 percent oxygen (Cc) shall be computed using the following equation:
20.9« 02d
where:
cc - Concentration of TOC (minus methane and ethane) corrected to
3 percent Q£, dry basis, parts per million by volume.
CjOC " Concentration of TOC (minus methane and ethane), dry basis,
parts per million by volume.
Concentration of oxygen, dry basis, percent by volume.
(4) Method 18 to determine the concentration of TOC (less methane
and ethane) at the outlet of the control device when determining
compliance with the 20 parts per million by volume limit, or at both the
control device inlet and outlet when the reduction efficiency of the
control device is to be determined.
(i) The minimum sampling time for each run shall be 1 hour in which
either an integrated sample or four grab samples shall be taken. If grab
sampling is used then the samples shall be taken at 15-minute intervals.
(ii) The emission reduction (R) of TOC (less methane and ethane)
shall be determined using the following equation:
R - Ei ' E° x 100
El
where:
R - Emission reduction, percent by weight.
Ei = Mass rate of TOC (minus methane and ethane) entering the control
device, kilogram TOC per hour.
E0 = Mass rate of TOC (minus methane and ethane) discharged to the
atmosphere, kilogram TOC per hour.
D-9
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EXAMPLE ONLY
(iii) The mass rates of TOC (E-j, E0) shall be computed using the
following equations:
Ei - K2 ( ZCijMij) Qi
J ™ •*•
E0 • K2 ( I CojM0j) Qo
j-l
where:
Cij> CQJ = Concentration of sample component "j" of the gas stream at
the inlet and outlet of the control device, respectively,
dry basis, parts per million by volume.
Mij> MOJ * Molecular weight of sample component "j" of the gas stream
at the inlet and outlet of the control device,
respectively, grams per gram-mole.
Qi, Q0 - flow rate of gas stream at the inlet and outlet of the
control device, respectively, dry standard cubic meters
per minute.
«2 = 2.494 x 10'6 (liters per minute) (gram-mole per standard
cubic meter) (kilogram per gram)(minute per hour), where
standard temperature for (gram-mole per standard cubic
meter) is 20 °C.
(iv) The TOC concentration (Cjoc) ^s tne sum °f tne individual
components and shall be computed for each run using the following
equation:
CTOC - *
J-i
where:
CTQC = Concentration of TOC (minus methane and ethane), dry basis,
parts by million by volume.
Cj - Concentration of sample component "j", dry basis, parts per
million by volume.
n - Number of components in the sample.
D-10
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EXAMPLE ONLY
(5) When a boiler or process heater with a design heat input
capacity of 44 megawatts or greater, or a boiler or process heater into
which the process vent stream is introduced with the primary fuel, is
used to comply with the control requirements, an initial performance test
is not required.
(d) When a flare is used to comply with the control requirements of
this rule, the flare shall comply with the requirements of 40 CFR 60.18.
(e) The following test methods shall be used to determine compliance
with the TRE index value.
(1) Method 1 or 1A, as appropriate, for selection of the sampling
site.
(i) The sampling site for the vent stream molar composition
determination and flow rate prescribed in D.5(e)(2) and (e)(3) shall be,
except for the situations outlined in paragraph (e)(l)(ii) of this
section, after the final recovery device, if a recovery system is present,
prior to the inlet of any control device, and prior to any post-reactor or
post-distillation unit introduction of halogenated compounds into the
process vent stream. No traverse site selection method is needed for
vents smaller than 10 centimeters in diameter.
(ii) If any gas stream other than the reactor or distillation vent
stream is normally conducted through the final recovery device:
(A) The sampling site for vent stream flow rate and molar
composition shall be prior to the final recovery device and prior to the
point at which any nonreactor or nondistillation stream or stream from a
nonaffected reactor or distillation unit is introduced. Method 18 shall
be used to measure organic compound concentrations at this site.
(B) The efficiency of the final recovery device is determined by
measuring the organic compound concentrations using Method 18 at the inlet
to the final recovery device after the introduction of all vent streams
and at the outlet of the final recovery device.
(C) The efficiency of the final recovery device determined according
to D.5(e)(l)(ii)(B) shall be applied to the organic compound
concentrations measured according to D.5(e)(l)(11)(A) to determine the
concentrations of organic compounds from the final recovery device
D-ll
-------
EXAMPLE ONLY
attributable to the reactor or distillation vent stream. The resulting
organic compound concentrations are then used to perform the calculations
outlined in D.5(e)(4).
(2) The molar composition of the vent stream shall be determined as
follows:
(i) Method 18 to measure the concentration of organic compounds
including those containing halogens.
(ii) ASTM D1946-77 to measure the concentration of carbon monoxide
and hydrogen.
(iii) Method 4 to measure the content of water vapor.
(3) The volumetric flow rate shall be determined using Method 2, 2A,
2C, or 2D, as appropriate.
(4) The emission rate of TOC (minus methane and ethane) (Ejoc) in
the vent stream shall be calculated using the following equation:
ETOC - K2 Z CjMj Qs
J~ 1
where:
Ejoc = Emission rate of TOC (minus methane and ethane)
in the sample, kilograms per hour.
K2 = Constant, 2.494 x 10'6 (liters per parts per
mill ion)(gram-moles per standard cubic meter)(kilogram per
gram)(minute per hour), where standard temperature for
(gram-mole per standard cubic meter)(g-mole/scm) is 20 °C.
Cj = Concentration of compound j, on a dry basis, in parts per
million as measured by Method 18, as indicated in D.5(c)(3).
MJ - Molecular weight of sample j, grams per gram-mole.
Qs = Vent stream flow rate (standard cubic meters per minute) at a
temperature of 20 °C.
(5) The total process vent stream concentration (by volume) of
compounds containing halogens (parts per million by volume, by compound)
shall be summed from the individual concentrations of compounds containing
halogens which were measured by Method 18.
D-12
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EXAMPLE ONLY
(6) The net heating value of the vent stream shall be calculated
using the equation:
HT - KI £ Cj Hj {1 . BWS)
where:
Hf « Net heating value of the sample (megajoule per standard cubic
meter), where the net enthaply per mole of vent stream is based
on combustion at 25 °C and 760 millimeters of mercury, but the
standard temperature for determining the volume corresponding
to one mole is 20 °C, as in the definition of Qs (vent stream
flow rate).
KI * Constant, 1.740 x 10"7 (parts per million)'1 (gram-mole per
standard cubic meter), (megajoule per kilocalorie), where
standard temperature for (gram-mole per standard cubic meter)
is 20 °C.
Bws * Water vapor content of the vent stream, proportion by volume;
except that if the vent stream passes through a final stream
jet and is not condensed, it shall be assumed that Bws * 0.023
in order to correct to 2.3 percent moisture.
Cj = Concentration on a dry basis of compound j in parts per
million, as measured for all organic compounds by
Method 18 and measured for hydrogen and carbon monoxide by
the American Society for Testing and Materials D1946-77.
HJ = Net heat of combustion of compound j, kilocalorie per
gram-mole, based on combustion at 25 °C and 760 millimeters of
mercury. The heats of combustion of vent stream components
shall be determined using American Society for Testing and
Materials D2382-76 if published values are not available or
cannot be calculated.
(f)(l) The total resource effectiveness index value of the vent
shall be calculated using the following equation:
TRE - _1_ [a + b (Qs) + c (HT) + d (ETOc)]
ETOC
where:
TRE - TRE index value.
ETQC = Hourly emission rate of TOC (kilograms per hour) as
calculated in D.5(e)(4).
D-13
-------
EXAMPLE ONLY
Qs = Vent stream flow rate standard cubic meters per minute at a
standard temperature of 20 °C.
Hj - Vent stream net heating value (megajoules per standard
cubic meter), as calculated in D.5(e)(6).
EJOC = Hourly emission rate of TOC (minus methane and ethane),
(kilograms per hour) as calculated in paragraph D.5(e)(4).
a,b,c,d = Coefficients presented in Table D-l.
(2) The owner or operator of a vent stream shall use the applicable
coefficients in Table D-l to calculate the TRE index value based on a
flare, a thermal incinerator with 0 percent heat recovery, and a thermal
incinerator with 70 percent heat recovery, and shall select the lowest TRE
index value.
(3) The owner or operator of a unit with a halogenated vent stream,
determined as any stream with a total concentration of halogen atoms
contained in organic compounds of 200 parts per million by volume or
greater, shall use the applicable coefficients in Table D-l to calculate
the total resource effectiveness index value based on a thermal
incinerator and scrubber.
(g) Each owner or operator of an affected facility seeking to comply
with D.4(b) shall recalculate the flow rate and TOC concentration for that
affected facility whenever process changes are made. Examples of process
changes include changes in production capacity, feedstock type, or
catalyst type, or whenever there is replacement, removal, or addition of
recovery equipment. The flow rate and VOC concentration shall be
recalculated based on test data, or on best engineering estimates of the
effects of the change to the recovery system.
(h) Where the recalculated values yield a total resource
effectiveness index <1.0, the owner or operator shall notify the State air
quality management agency within 1 week of the recalculation and shall
conduct a performance test according to the methods and procedures
required by D.5.
D-14
-------
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D-15
-------
EXAMPLE ONLY
(i) For the purpose of demonstrating that a process vent stream has
a VOC concentration below 500 parts per million by volume, the following
to set procedures shall be followed:
(1) The sampling site shall be selected as specified in D.5(c)(l).
(2) Method 18 or Method 25A of Part 60, Appendix A shall be used to
measure concentration; alternatively, any other method or data that has
been validated according to the protocol in Method 301 of Part 63,
Appendix A may be used.
(3) Where Method 18 is used, the following procedures shall be used
to calculate parts per million by volume concentration:
(i) The minimum sampling time for each run shall be 1 hour in which
either an integrated sample or four grab samples shall be taken. If grab
sampling is used, then the samples shall be taken at approximately equal
intervals in time, such as 15 minute intervals during the run.
(ii) The concentration of TOC (minus methane and ethane) shall be
calculated using Method 18 according to D.5(c)(4).
(4) Where Method 25A is used, the following procedures shall be used
to calculate parts per million by volume TOC concentration:
(i) Method 25A shall be used only if a single VOC is greater than
50 percent of total VOC, by volume, in the process vent stream.
(ii) The process vent stream composition may be determined by either
process knowledge, test data collected using an appropriate EPA Method or
a method of data collection validated according to the protocol in
Method 301 of Part 63, Appendix A. Examples of information that could
constitute process knowledge include calculations based on material
balances, process stoichiometry, or previous test results provided the
results are still relevant to the current process vent stream conditions.
(iii) The VOC used as the calibration gas for Method 25A shall be
the single VOC present at greater than 50 percent of the total VOC by
volume.
(iv) The span value for Method 25A shall be 50 parts per million by
volume.
(v) Use of Method 25A is acceptable if the response from the
high-level calibration gas is at least 20 times the standard deviation of
D-16
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EXAMPLE ONLY
the response from the zero calibration gas when the instrument is zeroed
on the most sensitive scale.
(vi) The concentration of TOC shall be corrected to 3 percent oxygen
using the procedures and equation in D.5(c)(3).
(5) The owner or operator shall demonstrate that the concentration
of TOC including methane and ethane measured by Method 25A is below
250 parts per million by volume with VOC concentration below 500 parts per
million by volume to qualify for the low concentration exclusion.
D.6 MONITORING REQUIREMENTS
(a) The owner or operator of an affected facility that uses an
incinerator to seek to comply with the TOC emission limit specified under
D.4(a)(l) shall install, calibrate, maintain, and operate according to
manufacturer's specifications: a temperature monitoring device equipped
with a continuous recorder and having an accuracy of ±0.5 °C, whichever is
greater.
(1) Where an incinerator other than a catalytic incinerator is used,
a temperature monitoring device shall be installed in the firebox.
(2) Where a catalytic incinerator is used, temperature monitoring
devices shall be installed in the gas stream immediately before and after
the catalyst bed.
(b) The owner or operator of an affected facility that uses a flare
to seek to comply with D.4(a)(2) shall install, calibrate, maintain, and
operate according to manufacturer's specifications, a heat-sensing device,
such as a ultraviolet beam sensor or thermocouple, at the pilot light to
indicate continuous presence of a flame.
(c) The owner or operator of an affected facility that uses a boiler
or process heater with a design heat input capacity less than 44 megawatts
to seek to comply with D.4(a)(l) shall install, calibrate, maintain, and
operate according to the manufacturer's specifications, a temperature
monitoring device in the firebox. The monitoring device should be
equipped with a continuous recorder and having an accuracy of ±1 percent
of the temperature being measured expressed in degrees Celsius or ±0.5 °C,
whichever is greater. Any boiler or process heater in which all vent
streams are introduced with primary fuel is exempt from this requirement.
D-17
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EXAMPLE ONLY
(d) The owner or operator of an affected facility that seeks to
demonstrate compliance with the total resource effectiveness index limit
specified under D.4(b) shall install, calibrate, maintain, and operate
according to manufacturer's specifications the following equipment:
(1) Where an absorber is the final recovery device in the recovery
system:
(i) A scrubbing liquid temperature monitor equipped with a
continuous recorder.
(ii) Specific gravity monitor equipped with continuous recorders.
(2) Where a condenser is the final recovery device in the recovery
system, a condenser exit (product side) temperature monitoring device
equipped with a continuous recorder and having an accuracy of ±1 percent
of the temperature being monitored expressed in degrees Celsius or
±0.5 °C, whichever is greater.
(3) Where a carbon adsorber is the final recovery device unit in the
recovery system, an integrating regeneration stream flow monitoring device
having an accuracy of ±10 percent, capable of recording the total
regeneration stream mass flow for each regeneration cycle; and a carbon
bed temperature monitoring device having an accuracy of ±1 percent of the
temperature being monitored expressed in degrees Celsius of ±0.5 °C,
capable of recording the carbon bed temperature after each regeneration
and within 15 minutes of completing any cooling cycle.
(4) Where an absorber scrubs halogenated streams after an
incinerator, boiler, or process heater, the following monitoring equipment
is required for the scrubber.
(i) A pH monitoring device equipped with a continuous recorder.
(ii) Flow meters equipped with a continuous recorders to be located
at the scrubber influent for liquid flow and the scrubber inlet for gas
stream flow.
(e) The owner or operator of a process vent using a vent system that
contains bypass lines that could divert a vent stream away from the
combustion device used shall either:
(1) Install, calibrate, maintain, and operate a flow indicator that
provides a record of vent stream flow at least once every 15 minutes. The
D-18
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EXAMPLE ONLY
flow indicator shall be installed at the entrance to any bypass line that
could divert the vent stream away from the combustion device to the
atmosphere; or
(2) Secure the bypass line valve in the closed position with a
car-seal or a lock-and-key type configuration. A visual inspection of the
seal or closure mechanism shall be performed at least once every month to
ensure that the valve is maintained in the closed position and the vent
stream is not diverted through the bypass line.
D.7 REPORTING/RECORDKEEPING REQUIREMENTS
(a) Each reactor process or distillation operation subject to this
rule shall keep records of the following parameters measured during a
performance test or TRE determination required under D.5, and required to
be monitored under D.6.
(1) Where an owner or operator subject to the provisions of this
subpart seeks to demonstrate compliance with D.4(a)(l) through use of
either a thermal or catalytic incinerator:
(i) The average firebox temperature of the incinerator (or the
average temperature upstream and downstream of the catalyst bed for a
catalytic incinerator), measured at least every 15 minutes and averaged
over the same time period of the performance testing, and
(ii) The percent reduction of TOC determined as specified in D.5(c)
achieved by the incinerator, or the concentration of TOC (parts per
million by volume, by compound) determined as specified in D.5(c) at the
outlet of the control device on a dry basis corrected to 3 percent oxygen.
(2) Where an owner or operator subject to the provisions of this
subpart seeks to demonstrate compliance with D.4(a)(l) through use of a
boiler or process heater:
(i) A description of the location at which the vent stream is
introduced into the boiler or process heater, and
(ii) The average combustion temperature of the boiler or process
heater with a design heat input capacity of less than 44 megawatt measured
at least every 15 minutes and averaged over the same time period of the
performance testing.
D-19
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EXAMPLE ONLY
(iii) Any boiler or process heater in which all vent streams are
introduced with primary fuel are exempt from these requirements.
(3) Where an owner or operator subject to the provisions of this
subpart seeks to demonstrate compliance with 0.4(a)(2) through use of a
smokeless flare; flare design (i.e., steam-assisted, air-assisted, or
nonassisted), all visible emission readings, heat content determinations,
flow rate measurements, and exit velocity determinations made during the
performance test, continuous records of the flare pilot flame monitoring,
and records of all periods of operations during which the pilot flame is
absent.
(4) Where an owner or operator subject to the provisions of this
subpart seeks to demonstrate compliance with D.4(b):
(i) Where an absorber is the final recovery device in the recovery
system, the exit specific gravity (or alternative parameter which is a
measure of the degree of absorbing liquid saturation, if approved, by the
permitting authority), and average exit temperature of the absorbing
liquid measured at least 15 minutes and averaged over the same time period
of the performance testing (both measured while the vent stream is
normally routed and constituted), or
(ii) Where a condenser is the final recovery device the recovery
system, the average exit (product side) temperature measured at least
every 15 minutes and averaged over the same time period of the performance
testing while the vent stream is routed and constituted normally, or
(iii) Where a carbon adsorber is the final recovery device in the
recovery system, the total stream mass or volumetric flow measured at
least every 15 minutes and averaged over the same time period of the
performance test (full carbon bed cycle), temperature of the carbon bed
after regeneration (and within 15 minutes of completion of any cooling
cycle(s)), and duration of the carbon bed steaming cycle (all measured
while the vent stream is routed and constituted normally), or
(iv) As an alternative to D.7(a)(4)(i), (a)(4)(ii) or (a)(4)(iii),
the concentration level or reading indicated by the organics monitoring
device at the outlet of the absorber, condenser, or carbon adsorber,
measured at least every 15 minutes and averaged over the same time period
D-20
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EXAMPLE ONLY
as the performance testing while the vent stream is normally routed and
constituted.
(v) All measurements and calculations performed to determine the
flow rate, and volatile organic compound concentration, heating value, and
TRE index value of the vent stream.
(b) Each reactor process or distillation operation subject to this
guideline will also be subject to the exceedance reporting requirements of
the draft Enhanced Monitoring Guideline. The specifics of the
requirements will be added to this document when the Enhanced Monitoring
Guideline is quotable.
(c) Each reactor process or distillation operation seeking to comply
with D.4(b) shall also keep records of the following information:
(1) Any changes in production capacity, feedstock type, or catalyst
type, or of any replacement, removal, and addition of recovery equipment
or reactors and distillation units.
(2) Any recalculation of the flow rate, TOC concentration, or TRE
value performed according to D.5(g).
(d) Each reactor process or distillation operation seeking to comply
With the flow rate or concentration exemption level in D.2(b)(4) shall
keep records to indicate that the stream flow rate is less than
0.0085 standard cubic meters per minute or the concentration is less than
500 parts per million by volume.
(e) Each reactor process or distillation operation seeking to comply
with the production capacity exemption level of 1 gigagrams per year shall
keep records of the design production capacity or any changes in equipment
or process operation that may affect design production capacity of the
affected process unity.
D-21
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APPENDIX E
ENVIRONMENTAL IMPACTS CALCULATIONS
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APPENDIX E
ENVIRONMENTAL IMPACTS CALCULATIONS
E.I CALCULATION OF SECONDARY AIR IMPACTS
Calculations will be based on model stream R-LFHH, the same stream
used as an example in Appendix C.
E.2 ESTIMATING CARBON MONOXIDE EMISSIONS
Calculate total heat input of the stream to be combusted.
(1) HI = Initial heat input of waste stream
HI = (flow rate)(heat value)
= (23.54 scfm)(209.7 Btu/scf)
= 4,936 Btu/min x (60 min/hr) x (8,760 hr/yr) x
(MMBtu/106 Btu)
= 2,595 MMBtu/yr
(2) H£ = Heat input from auxiliary fuel
H2 = (flow rate)(heat value)
- (0.1 scfm)(1,000 Btu/scf)
= 100 Btu/min
=52.5 MMBtu/yr
(3) Total heat input = Hi + Hp
= (2,595 + 52.5) MMBtu/yr
= 2,648 MMBtu/yr
Calculate carbon monoxide (CO) emissions using AP-42 factor of 20 Ib
CO/MMscf of fuel.
(1) Convert MMBtu/yr to equivalent fuel flow (Qp)
QF = (2,698 MMBtu/yr)(scf/1,000 Btu)
=2.6 MMscf/yr
(2) C0em = (2.6 MMscf/yr)(20 lb/MMscf)(Mg/2,207 Ib)
=0.02 Mg/yr of CO
E-l
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E.3 ESTIMATING NITROGEN OXIDES EMISSIONS
Determine method of control (flare or incinerator). Model stream
R-LFHH is cheapest to control using incinerator with scrubber (see
Appendix C for costing analysis).
For incinerators, two nitrous oxide (NOX) emission factors are used:
one for streams containing nitrogen compounds, and one for streams without
nitrogen compounds. Inert nitrogen gas (Ng) is not included. The NOX
factors for incinerators are as follows:
with nitrogen compounds: 200 ppm in exhaust
without nitrogen compounds: 21.5 ppm in exhaust
The model stream R-LFHH has no nitrogen, so 21.5 ppm will be used. These
factors reflect testing data that was gathered for the Air Oxidation
Reactor processes CTG and the Polymers and Resins CTG.
Calculate total outlet flow, as explained in Appendix C. As shown in
Section C.4, the total outlet flow exiting the incinerator/scrubber system
is 53 scfm.
(1) NOX emissions = (53 scfm)(21.5/106)/(392 scf/lb-mole) x
(46 Ib/lb-mole)
NOX emissions = (0.000134 Ib/min) x (60 min/hr) x
(8,760 hr/yr) x (Mg/2,207 Ib)
- 0.032 Mg/yr
(2) If the total outlet flow rate from the incinerator is not known,
the following emission factors may be used to calculate NOX emissions:
with nitrogen compounds: 0.41 Ib NOx/MMBtu
without nitrogen compounds: 0.08 Ib NOx/MMBtu
As calculated in E.2 (3), the total heat input is 2,648 MMBtu/yr.
Therefore, the NOX emissions estimated using this factor are calculated
by:
NOX emissions - (2,648 MMBtu/yr)(0.08 Ib NOx/MMBtu) x (Mg/2,207 Ib)
=0.10 Mg/yr
E-2
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APPENDIX F
RESPONSE TO PUBLIC COMMENTS RECEIVED ON THE DRAFT SYNTHETIC
ORGANIC CHEMICAL MANUFACTURING INDUSTRY REACTOR PROCESSES
AND DISTILLATION OPERATIONS CONTROL TECHNIQUES GUIDELINE
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APPENDIX F
RESPONSE TO PUBLIC COMMENTS RECEIVED ON THE DRAFT SYNTHETIC
ORGANIC CHEMICAL MANUFACTURING INDUSTRY REACTOR PROCESSES
AND DISTILLATION OPERATIONS CONTROL TECHNIQUES GUIDELINE
F.I INTRODUCTION
On December 12, 1991, the U. S. Environmental Protection Agency (EPA)
announced the availability of a draft control techniques guideline (CTG)
document for "The Control of Volatile Organic Compound Emissions from
Reactor Processes and Distillation Operations Processes in the Synthetic
Organic Chemical Manufacturing Industry" (56 FR 64785). Public comments
were requested on the draft CTG in that Federal Register notice. Thirteen
comments were received. Table F.l-1 lists the commenters, their
affiliations, and the EPA docket number assigned to their correspondence.
The major topics of the comments were: the recommendation to incorporate a
total resource effectiveness (TRE) index approach for determining
applicability; the recommendation for less stringent flow cutoffs; and a
concern that the cost of complying with the recommended control level is
too high. The comments that were submitted, along with responses to these
comments, are summarized in this appendix. The summary of comments and
responses serve as the basis for the revisions made to the CTG between the
draft and final document.
F.2 SUMMARY OF CHANGES TO THE DRAFT CONTROL TECHNIQUES GUIDELINE
Several changes and clarifications were made in the CTG as a result
of review of public comments. These changes and clarifications were made
in the following areas: (1) use of the TRE index equations;
(2) aggregation of vent streams to a control device; (3) location of flow
indicators; (4) definition of total organic compounds (TOC's);
(5) description of catalytic incinerators; (6) applicable chemicals;
F-l
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TABLE F.l-1. LIST OF COMMENTERS AND AFFILIATIONS
Docket item
number3 Commenter and affiliation
IV-D-1 Mr. Charles D. Malloch
Director, Regulatory Management
Environment, Safety and Health
Monsanto Company
800 N. Lindbergh Boulevard
St. Louis, Missouri 63167
IV-D-2 Mr. R.L. Arscott, General Manager
Health, Environmental and Loss
Protection
Chevron Corporation
Post Office Box 7924
San Francisco, California 94120-7924
IV-D-3 Mr. David W. Gustafson
Environmental Quality
Mr. Sam P. Jordan
Environmental Law
The Dow Chemical Company
Midland, Michigan 48667
IV-D-4 Mr. John A. Dege
CAA Issue Manager
DuPont Chemicals
Wilmington, Delaware 19898
IV-D-5 V.M. Mclntire
Environmental Affairs
Eastman Chemical Company
Post Office Box 511
Kingsport, Tennessee 37662
IV-D-6 Ms. Sherry L. Edwards, Manager
Government Relations
Synthetic Organic Chemical Manufacturers
Association, Incorporated
1330 Connecticut Avenue, N.W., Suite 300
Washington, D.C. 20036-1702
IV-G-2 M.L. Mullins
Vice President, Regulatory Affairs
Chemical Manufacturers Association
2501 M Street, N.W.
Washington, D.C. 20037
F-2
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TABLE F.l-1. LIST OF COMMENTERS AND AFFILIATIONS
(CONCLUDED)
Docket item
number3 Commenter and affiliation
IV-G-3 Mr. E. G. Collier
Chairman, Control Techniques
Guidelines Subcommittee
Texas Chemical Council
IV-G-4 Mr. B.L. Taranto
Environmental Affairs Department
Exxon Chemical Americas
Post Office Box 3272
Houston, Texas 77253-3272
IV-G-5 Ms. Regina M. Flahie
Chief
Division of Interagency and International
Affairs
U. S. Department of Labor, Occupational
Safety and Health Administration
Washington, D.C. 20210
IV-G-6 Mr. G. E. Addison
Manager, Planning and Development
ARI Technologies, Incorporated
600 N. First Bank Drive
Palatine, Illinois 60067
IV-G-7 Mr. Raymond J. Connor
Technical Director
Manufacturers of Emission Controls
Association
1707 L Street, N.W., Suite 570
Washington, D.C. 20036-4201
IV-G-8 Mr. Kevin Ewing
Market Manager
Thermotron Industries
291 Kollen Park Drive
Holland, Michigan 49423
aThe docket number for this project is SOCMI CTG A-91-38. Dockets are on
file at the EPA Air Docket in Washington, D.C.
F-3
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(7) definition of product; (8) definition of halogenated stream;
(9) exemption of streams with a flow rate or concentration below a cutoff
value; and (10) definition of affected facility.
The comments summarized in this appendix have been organized into the
following categories: Applicability of the Control Techniques Guideline;
Recommendation of Reasonably Available Control Technology; Cost
Effectiveness, Monitoring and Testing, and Editorial.
F.3 APPLICABILITY OF THE CONTROL TECHNIQUES GUIDELINE
F.3.1 Comment: One commenter (IV-G-4) disagreed with the assertion on
pages 6-7 and 6-8 of the draft CTG that the recommended applicability
criteria provide an incentive for pollution prevention. The commenter
stated that since control by combustion (or equivalent control) would be
required for the residual emissions from virtually any recovery device, the
incentive to install such a device would be diminished. The commenter
suggested that an incentive could be provided for control of vent emissions
by combusting the residuals as primary fuel.
Response: The incentive referred to on pages 6-7 and 6-8 of the
draft CTG pertains to an incentive for any pollution prevention or
recycling practice that lowers emissions below the cutoff level. Pollution
prevention and recycling can include any process change—including the
addition of recovery devices—that significantly reduces the amount of
pollutants that are emitted from the process unit. In the case of this
CTG, the recommended presumptive norm for reasonably available control
technology (RACT) would allow an affected facility to avoid having to
install an add-on combustion control device if the affected facility lowers
emissions below the cutoff. The EPA believes that this provision
encourages pollution prevention and recycling.
F.3.2 Comment: One commenter (IV-D-5) requested that the EPA include in
this CTG a statement that distillation operations that are part of polymer
manufacturing processes are not covered by this CTG. The commenter
reasoned that this would be consistent with the applicability criteria for
the new source performance standards (NSPS) for distillation operations
(40 CFR Part 60 Subpart NNN).
Response: It is not the intent of this CTG to provide guidance for
process vents that are subject to regulations for the polymer manufacturing
F-4
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industry. To clarify that these facilities are not subject to this CTG, an
exemption statement has been added to this document (see Section 7.4).
F.3.3 Comment: Two commenters (IV-D-2, IV-G-2) suggested that the CTG
provide a more detailed discussion of the overlap between the source
categories and chemicals covered under this CTG, and the source categories
and hazardous air pollutants (HAP's) covered under Title III of the Clean
Air Act (CAA), as amended in 1990.
One commenter (IV-G-2) further stated that the EPA should strive for
consistency between Title I RACT and Title III maximum achievable control
technology (MACT) with respect to the application of control standards,
testing, monitoring, and reporting requirements.
Response: The EPA understands that more clarification is needed to
explain which chemicals within the SOCMI source category are applicable to
this CTG and which are subject to Title III of the CAA. The SOCMI is a
broad source category that includes any manufacturer of synthetic organic
chemicals. Appendix A of this CTG has been revised to present the organic
chemicals that are subject to this CTG. Appendix A also indicates which
chemicals in this list are listed as part of the SOCMI source category and
which chemicals are subject to the proposed Hazardous Organic National
Emission Standard for Hazardous Air Pollutants (HON), or any of the
following regulations: the air oxidation processes NSPS; distillation
operations NSPS; and the reactor processes NSPS. The regulations' and
rules' applicability criteria is based on the chemical manufactured. For
example, hexanedioic acid is manufactured using a reactor and distillation
unit and is subject to this CTG, the distillation NSPS, and the reactor
process NSPS. However, hexanedioic acid is not manufactured using an air
oxidation process and, therefore, is not subject to the air oxidation
process NSPS.
Although there are appropriate differences with respect to
applicability, the EPA wants to eliminate duplicate performance testing,
reporting and recordkeeping, and monitoring requirements. The EPA is
considering options to deal with the interface between regulations
promulgated under Section 112 of the Clean Air Act and RACT rules.
Specifically, the EPA is developing a policy statement for emission points
that will be affected both by the HON and RACT rules. This policy
statement will be published in the Federal Register when completed.
F-5
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Pursuant to the CTG, recordkeeping and reporting requirements have been
left to the discretion of the State air quality management agencies as
stated in Section 7.7 (Reporting/Recordkeeping Requirements) of the CTG
document; however, emission points subject to the HON would be subject to
the recordkeeping and reporting requirements of the HON.
The controls required to comply with the SOCMI NSPS, CTG's and the
HON are the same and are based on the same control technology--that is,
combustion. The cutoff levels for applicability may be different, however,
because VOC's are the subject of the CTG's and the NSPS, and organic HAP's
are the subject of the proposed HON.
F.3.4 Comment: Several commenters (IV-D-3, IV-D-4, IV-D-5, IV-D-6,
IV-G-2, IV-G-3) recommended the incorporation of a TRE index as another
option to the already suggested presumptive norm for RACT. Two commenters
(IV-D-3, IV-G-2) suggested that using a TRE index would help to achieve a
more cost-effective VOC control by using the least amount of energy,
capital, and total resources. The commenters also suggested that
incorporation of a TRE index furthers the application of pollution
prevention principles by encouraging increased product recovery techniques
and other process modifications that ultimately reduce VOC emissions, often
by using more cost-effective techniques.
Response: To remain consistent with the other SOCMI regulations, the
EPA has decided to incorporate the TRE index applicability approach to
replace the flow and concentration limits that appeared in the draft CTG.
This decision was reached after the draft CTG document was made available
for public comment. The final copy of the CTG includes the TRE index.
The TRE index equation is a decision tool used to determine if the
annual cost of controlling a given vent stream (as determined using the
standard procedure described in Chapter 5) is acceptable when considering
the emission reductions achieved. The TRE index is a measure of the total
resource burden associated with emission control for a given vent stream.
The TRE index equation is normalized so that the decision point has a
defined value of 1.0. The variables in the TRE index equation are the
stream characteristics (i.e., flow rate, heat content, VOC emission rate).
This TRE index equation is developed from a multivariable linear regression
of the cost algorithm. It is recommended that the owner or operator
demonstrate that a TRE index is greater than 1.0 at the outlet of the final
F-6
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recovery device in order to avoid having to control VOC emissions. If the
TRE index is less than or equal to 1.0 at the point of measurement, the
owner or operator could elect either to modify the process or, install an
additional recovery device or a control device that results in a TRE index
greater than 1.0.
The cost-effectiveness criteria built into the TRE index equation
allow for greater emission reductions at the same cost compared to the flow
and concentration limits alone. With the TRE equation, the CTG allows the
flexibility to reduce VOC emission by whatever means the owner or operator
prefers. Pollution prevention that increases product or raw material
recovery may be the most cost-effective (and even the most beneficial)
method to reduce VOC emissions and is encouraged.
F.3.5 Comment: Several commenters (IV-D-3, IV-D-5, IV-G-2, IV-G-3,
IV-G-4) questioned the feasibility and stringency of the CTG combined vent
criteria. Several commenters (IV-D-3, IV-D-5, IV-G-2, IV-G-3) argued that
the concentration and flow cutoff should apply only to individual vent
streams and not the combination of all vent streams in the process unit.
Two commenters (IV-D-3, IV-G-2) also pointed out that the combined vent
criteria appear to be more stringent than those in the NSPS because the CTG
flow cutoff applies to multiple vents, regardless of whether a common
recovery system into which the vents are discharged exists.
Several commenters (IV-D-3, IV-G-2, IV-G-3, IV-G-4) suggested that
situations exist where it is not technically feasible, economical, or safe
to combine vent streams. One commenter (IV-G-3) noted the following two
examples that illustrate the safety concerns:
• Combining two streams where one stream is below the lower
explosive limit and another stream is above the explosive
limit, or
• Combining two streams that are chemically reactive.
Response: The combined stream criteria were included in this CTG
because the practice of combining streams is often used in industry for
similar process vent streams within the same process unit. The EPA
recognizes that circumstances exist where it may not be technically
feasible, economical, or safe to combine vent streams and, therefore, it
should not be a control criterion. Because this approach cannot be
generalized across the entire industry, the combined vent applicability
F-7
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approach has been omitted from the CTG document. Furthermore, it should be
noted that the applicability limits were written for individual streams and
were not intended to determine applicability limitations on a combined
stream basis. The applicability calculations continue to be conducted on
an individual vent stream basis after the CTG was revised to incorporate
the TRE.
F.3.6 Comment: One commenter (IV-D-1) noted that on page 2-7 of the draft
CTG, the EPA refers to "176 high-volume chemicals" that "involve reactor
processes." The commenter further noted that on page 2-33, the EPA refers
to the scope of the reactor processes covered in the CTG as representing
"one of the 173 reactor process chemicals." The commenter recommended that
the EPA revise Appendix A of the CTG to indicate 173 chemicals (thus
representing the similar list used in the NSPS), which the CTG intended to
cover under reactor processes.
In addition, the commenter noted that the final NSPS for distillation
operations lists the chemicals for its applicability. The commenter
recommended that Appendix A of the draft CTG be shortened to include only
those chemicals used for determining applicability of distillation
operations. The commenter then suggested that the applicability statement
in Section D.2.a on page D-l of Appendix D in the draft CTG should be
expanded to state that the process unit subject to this CTG should be one
for which a chemical is listed in Appendix A.
Response: The reference on page 2-7 of the document is an industry
characterization. There is no statement to suggest that the
176 high-volume chemicals listed there are the only chemicals within the
scope of this CTG. These 176 chemicals are a subset of SOCMI chemicals
that are produced in large quantities. Appendix A lists the 719 chemicals
subject to this CTG. This list also identifies those chemicals that are
also subject to the Distillation NSPS, Air Oxidation NSPS, the Reactor
Process NSPS, the HON and other chemicals under the SOCMI source category.
It is the intent of the EPA to make subject of this CTG, any distillation
column or reactor operating as part of a process unit that makes one of the
chemicals listed in Appendix A. The applicability statement in Appendix D
has been expanded to state that the applicability of this CTG is based on
the chemicals that are listed in Appendix A.
F-8
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F.3.7 Comment: One commenter (IV-D-1) recommended that Table 2-5 on
page 2-47 of the draft CTG be revised to address more clearly the minimal
emissions occurring from atmospheric distillation operations. The
commenter said that, as drafted, the table does not identify what type of
operation corresponds to either the high or low emission rates. The
commenter cited personal experience that atmospheric distillation columns
used with low vapor pressure chemicals, such as adiponitrile or
hexamethylene diamine, do not have any detectable emissions from the
atmospheric vent.
The commenter also argued that condensers between the steam jets and
sometimes on the final jet discharge are very effective in controlling
emissions from distillation columns that process low-volatility chemicals,
with control efficiencies exceeding 95 percent in situations as described
above.
Response: Table 2-5 of the CTG document lists the average operating
characteristics of the distillation emission profile, in addition to the
range for these characteristics. The EPA realizes that the types of
operations that correspond to the values listed are not identified and that
processes may exist that are below those values.
With respect to the alternative VOC emissions reduction approach
described by the commenter, the EPA would like to clarify that the RACT
presumptive norm would not preclude the use of a condenser to reduce VOC
emissions from affected vent streams. If use of such a condenser were to
result in a TRE index value for the vent stream that is above the limit,
then no additional control would be required.
F.4 RECOMMENDATION OF REASONABLE AVAILABLE CONTROL TECHNOLOGY
F.4.1 Comment: Several commenters (IV-D-2, IV-D-4, IV-D-6, IV-G-2,
IV-G-4) expressed concern that the recommended control applicability cutoff
is too stringent. Six commenters (IV-D-4, IV-D-5, IV-D-6, IV-G-2, IV-G-3,
IV-G-4) pointed out that the proposed RACT de minimus flow rate is up to
four times more stringent than the distillation operations NSPS
requirements.
One commenter (IV-G-4) said that CTG cutoffs of 0.1 standard cubic
feet per minute (scfm) and 0.05 weight-percent VOC would result in a
calculated TRE of approximately 6,000 using the TRE equation from the
proposed HON. The commenter also noted that the proposed cutoffs
F-9
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correspond to a VOC emission rate of less than 5 pounds per year (Ib/yr),
and compared this emission rate to that of a single "nonleaking" valve in
light liquid service, which has an emission rate of 6 Ib/yr as calculated
using the EPA emission factors.
Two commenters (IV-D-6, IV-G-2) suggested that the CTG adopt Option 3
(e.g., flow rate <0.5 scfm and VOC weight percent <1) in Table 6-1 as the
RACT cutoff. One commenter (IV-D-6) emphasized that this option reduces
nationwide emissions by over 73 percent, and reduces the nationwide cost of
control by nearly 60 percent; yet still obtains almost 77 percent of the
emissions reduction achieved by the RACT cutoff proposed by the EPA.
Response: The EPA has reevaluated the applicability cutoff, as
mentioned in the response to comment number F.3.6, and the TRE index
equation will replace the flow or concentration limits that appeared in the
draft CTG. As pointed out by the commenters, use of the TRE equation will
provide consistency with the distillation NSPS and HON requirements.
F.4.2 Comment: One commenter (IV-D-3) noted that it is not obvious
whether the RACT cutoffs recommended by the CTG refer to instantaneous or
average values. The commenter suggested that the EPA specifically state
that the cut-off criteria for the concentration and flow are to be based on
an annual weighted average.
Response: The inputs to the TRE index equation are stream flow rate,
VOC emission rate, and heat content. These parameters should be average
values over the period of the performance test. The performance test
should be conducted under typical operating conditions, the specifics of
which are defined in the example rule (Appendix D).
F.4.3 Comment: One commenter (IV-D-6) stated that by definition in the
CAA, RACT requirements are less stringent than MACT requirements.
Therefore, the proposed RACT for SOCHI should be less stringent than MACT
for the same source categories.
Response: There is some confusion between MACT and RACT and the
level of stringency for each requirement. One cannot compare the
stringency levels of the two requirements because they are applicable to
two different groups of pollutants; MACT is applied to HAP's listed in
Section 112(b) of the CAA as amended in 1990, whereas RACT is applicable to
various of the criteria pollutants, including VOC, a precursor to ozone.
In some cases, the same vent stream may be subject to RACT criteria but not
F-10
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MACT criteria. Regardless of the applicability criteria, the control
requirement in all SOCMI regulations is 98 percent reduction of pollutants
or pollutant reduction down to a concentration level of 20 parts per
million by volume (ppmv) on a dry basis, corrected to 3 percent oxygen.
F.4.4 Comment; One commenter (IV-G-2) stated that the presumptive norm
described in the CTG document for SOCMI does not accurately describe the
types of emissions found to be emitted from reactor processes and
distillation operations. Although the VOC concentration cutoff and flow
rate cutoff help to ensure that insignificant vent streams do not require
unnecessary cost controls, the cutoffs do not account for the variation
that occurs from stream to stream due to chemical properties and associated
heating values. The commenter argued that a low heating value stream would
result in a much higher control cost than a high heating value stream, and
may not be appropriate as a presumptive norm for RACT.
Response: The EPA understands that in some cases low heating value
streams could result in higher costs than high heating value streams to
control, and has, therefore, incorporated the TRE index equation to the
applicability section. The TRE index identifies only those streams that
can be controlled in a cost-effective manner.
F.4.5 Comment; One commenter (IV-G-2) observed that the de minimus levels
suggested in the CTG document are incompatible with the levels found in the
NSPS. The commenter said that the establishment of such a low level will
prove to be of little use to the regulated community and, furthermore, by
setting a level that is inconsistent with current NSPS regulations, the EPA
places facilities in the awkward position of trying to comply with two
conflicting levels of control.
Response; This comment is resolved by the incorporation of TRE. As
indicated in the previous response, the parameters incorporated into the
TRE equation will allow for control of only those streams that can be
controlled on a cost-effective basis.
F.5 COST EFFECTIVENESS AND COST ESTIMATION
F.5.1 Comment; One commenter (IV-G-3) suggested that because a scrubber
is needed to remove hydrogen chloride (HC1) from the incinerator flue gas,
the discharge from this scrubber may significantly contaminate wastewater,
which would require treatment prior to discharge. Another commenter
(IV-D-5) questioned the EPA's judgment that costs associated with the
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disposal of salty wastewater formed by the neutralization of acidic
scrubber effluent were not significant. The commenter suggested that the
opportunity to use on-site wells is significantly limited, not only by
geographic considerations, but also regulatory concerns. Direct and
indirect discharges could also be limited by aquatic toxicity limits of the
National Pollutant Discharge Elimination Standards (NPDES) permit program.
Response: It is the decision of the EPA not to include the costs
associated with the disposal of salty wastewater in the cost equation for
VOC control devices. This decision was based on earlier work done on the
SOCMI reactor process NSPS. The effects from the discharge of wastewater
from the scrubbers were presented in 1984 in the background information
document (BID) for the Reactor Process NSPS. The water pollution impacts
were studied in 1982, at which time it was determined that the costs
associated with the disposal of the salty wastewater are not significant in
comparison to the overall control costs and, therefore, were not included
in the projected cost impacts. The specific reference in the Reactor
Process NSPS docket that explains the methodology is EPA Docket
No. A-83-29, Item No. II-B-25.
F.5.2 Comment: Several commenters (IV-D-4, IV-D-6 IV-G-2, IV-G-3)
emphasized that the EPA underestimated the installed equipment costs,
resulting in lower average cost-effectiveness numbers than industry is
currently experiencing. Three commenters (IV-D-4, IV-G-2, IV-G-3) noted
that the EPA indicated an installation factor of 1.61, which is much lower
than installation factors of 3 to 10 commonly encountered in the chemical
industry.
Response: The installed equipment costs and the installation factor
of 1.61 were determined using the EPA's Office of Air Quality Planning and
Standards Control Cost Manual (OCCM). Each chapter of the OCCM underwent
extensive industry review prior to finalization making this document the
accepted source by the EPA. The EPA believes that this installation factor
is consistent with what the majority of facilities from different
industries that install incinerators would encounter.
F.5.3 Comment: Two commenters (IV-G-4, IV-D-6) suggested that the
cost-effectiveness analysis is flawed and does not support the
applicability criteria. One commenter (IV-G-4) noted that in Table 6-1 of
the CTG, the average emission reduction per vent in the increment going
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from Option 3 to Option 2 is 0.0035 megagrams per year (Mg/yr). However,
vents of less than 0.003 Mg/yr would have to be controlled by the 0.1 scfm
and 0.05 weight percent applicability criteria given in the draft CTG.
Thus, the incremental cost effectiveness is calculated on a basis that
misrepresents the recommended applicability criteria by more than four
orders of magnitude. The commenter further noted that the cost
effectiveness of controlling a 0.1 scfm and 0.05 weight percent vent stream
is not addressed, and it should be in order to support its selection.
The commenter also felt that the cost data used to analyze regulatory
options is very low and unrealistic and should be updated or corrected to
reflect actual costs based on real plant experience. The commenter noted a
cost of $5,274 was assumed for 400 feet of an 8-inch flare collection
header, and suggested that the actual cost for this piping would exceed
$34,000, even in a noncongested area where pipe supports already exist.
The commenter also expressed concern that the flare cost estimate does not
appear to include the cost of piping and pumps to manage liquid from the
knockout drum, or the cost of piping and controls for the water supply to
the water seal drum, or for the air, steam, or gas to the flare tip.
Two commenters (IV-D-4, IV-D-6) stated that under the recommended
minimum emission levels, an emission flow rate of 0.11 scfm, with VOC
concentration of 0.06 weight-percent (which corresponds to 2.6 Ib/yr),
would require incineration and control. The cost effectiveness for the low
flow low heat case in Table 5-6 is $23,954 per megagram (Mg) for a
1.3 Ib/hr VOC inlet flow. The de minimus flow rate mentioned above emits
400 times less. The commenter then said that by simple multiplication, the
cost effectiveness balloons to $96,000,000 per megagram.
Response: The incremental cost effectiveness was calculated
correctly in the draft CTG document. The data base used for this analysis
contains many streams with high flow rates, but low concentrations.
Therefore, some streams with relatively high VOC loadings are not included
in the analysis until the most stringent options are imposed. Again,
further discussion of this table and calculated cost effectiveness is no
longer appropriate because the applicability format has been changed to
incorporate a TRE index equation. The TRE equation takes into account
these high cost considerations.
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As stated in response F.5.2, all costing analyses are in accordance
with the OCCM. The duct work cost assumptions are believed to represent
industry averages. The flare costs do include water seals and steam piping
to flare tip. Piping costs are accounted for by an installation factor.
F.5.4 Comment: Three commenters (IV-D-5, IV-G-2, IV-G-7) questioned
whether the EPA accounted for full "costing" of controls. One commenter
(IV-D-5) expressed concern that the EPA neither acknowledged nor adequately
considered the upstream impact of the control equipment in their emissions
analysis. The commenter suggested that there is a direct usage of fuel to
run control devices, as well as indirect emission impacts of:
(1) producing the fuels consumed as energy to produce the controls;
(2) producing the raw materials, such as caustic, to operate the control
devices; and (3) transporting these materials. The commenter asserted that
the EPA should consider these upstream impacts by including a factor, such
as an economic or cash flow multiplier, that would account for these
indirect impacts in the decision process as to what levels of controls are
actually environmentally beneficial.
Another consideration regarding full costing of controls was made by
two commenters (IV-G-2, IV-G-7) who requested that the EPA give greater
consideration to secondary air impacts due to the application of the
suggested control technologies. One commenter (IV-G-2) noted that by the
EPA's own admission, the recommended 98 percent control requirements
generate additional oxides of nitrogen (NOX), sulfur dioxide ($03), carbon
monoxide (CO) and particulate matter (PM). The commenter suggested that by
reducing the required level of control efficiency, secondary air impacts
will be reduced. One commenter (IV-G-7) argued that a significant issue
with thermal incineration is the production of NOX and CO as secondary
pollutants when large amounts of fuel are combusted to sustain the high
temperatures needed to operate these units. The commenter further cited
several disadvantages of thermal incineration including:
• High operating temperatures usually mean additional fuel
requirements and associated higher fuel costs;
• High generating temperatures require the use of special, more
costly heat resistant materials;
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• Longer residence times (greater than 1.5 seconds) than those
cited in the draft CTG mean larger, heavier reactors, which
generally must be installed at ground level rather than roof
mounted, resulting in additional expenses.
The commenter recommended that these should be viewed as
disadvantages for this control technology, and that Sections 3.1.2.1 and
3.1.2.2 of the CTG be expanded to include those disadvantages.
Response: With respect to "upstream" effects, it is beyond the scope
of this CTG to include in the costing equation those indirect emission
impacts listed by the commenter. However, the EPA generally includes
secondary air impacts due to the application of the suggested control
technologies in the analysis of RACT. These secondary air impacts are
explained in the environmental impacts discussion in Section 4.1.2 of the
draft CTG document rather than in the process description discussion.
Local agencies should consider the NOX and CO emissions associated with
control devices and may allow lower levels of VOC control to mitigate
secondary impacts if appropriate.
The disadvantages concerning thermal incineration cited in the
comment are realized by the EPA; however, recommendations for control
technologies assume average stream characteristics therefore, while thermal
incineration may not be appropriate for some lines, it would be a cost
effective means of control for others. The EPA need not consider the
"worst case" in developing the CTG.
F.5.5 Comment: One commenter (IV-G-4) recommended that the costs of
performance tests, monitoring, recordkeeping, and reporting also be
included in the CTG cost analysis.
One commenter (IV-G-3) argued that as the level of control and
monitoring continues to increase and as the regulatory guidelines for
"Enhanced Monitoring" evolve, the costs associated with the required
monitoring of new incineration devices are continuing to increase. The
commenter recommended that the present instrumentation cost factor of 0.10A
(e.g., instrument cost = 0.10 * [incinerator + auxiliary costs]) should be
reevaluated in light of the increasing costs associated with regulatory
monitoring requirements.
Response: The EPA's OCCM was used to determine the cost of
combustion technologies for control of VOC emissions. The capital costs
are presented in Table 5.2. As indicated in Table 5.2, performance test
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costs are included in the indirect cost of the control. Also in Table 5.2,
listed under the purchased equipment cost, is the instrumentation cost
required for the control device. This instrumentation would be used for
monitoring the control device. For example, temperature instrumentation
can be used to monitor the control efficiency of the control device.
The "Enhanced Monitoring" rule requirements are under development,
and that package will address the potential cost of the requirements of
that regulation, including additional costs placed on sources that are
already subject to some type of monitoring. The recordkeeping and
reporting requirements will vary among the States and, therefore, are not
included here.
F.5.6 Comment: One commenter (IV-G-4) thought that the annual operating
cost for an incinerator seems to be reasonably accurate but on the low
side.
Response: The EPA intends to investigate any documented numbers the
public may have, and invites this commenter to submit any documented
numbers to the EPA. Again, the annual operating costs were calculated from
the EPA's OCCM (see the response to comment F.5.2).
F.6 MONITORING AND TESTING
F.6.1 Comment: Two commenters (IV-D-4, IV-D-6) stated that the
requirements for scrubbing liquid temperature and specific gravity may not
be pertinent compliance information for some scrubbers, such as a
once-through water scrubber. They added that instrumentation should be
required only if it provides information essential to emission compliance.
Response: The CTG document has been revised to address the issue of
absorbers used as recovery devices versus absorbers used as scrubbers to
scrub halogens from a vent stream following an incinerator. The EPA
assumes that if an absorber is used in a recovery system, then the absorber
recycles (or has the potential to recycle) a portion of its effluent and is
not a once-though scrubber. Furthermore, the EPA assumes that the latter
use of absorbers, that is, to scrub halogens from an incinerator's
effluent, is the absorber the commenter refers to as a once-through
scrubber. As such, there are two sets of monitoring and testing
requirements in the model rule (Appendix D of the CTG) for the two absorber
types just described. For absorbers used in recovery systems, a scrubbing
liquid temperature monitor and a specific gravity monitor are required,
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both with continuous recordkeeping. For absorbers used after an
incinerator (a once-through scrubber), a pH monitoring device and flow
meter to measure scrubber liquid influent and inlet gas flow rates are
required, both with continuous recordkeeping.
F.6.2 Comment: One commenter (IV-D-6) suggested that as an alternative to
monitoring low flow rate vents, engineering calculations, and/or mass
balances information should be allowed to demonstrate an exemption from
control requirements.
Response: In order to be consistent with the draft HON, the EPA has
revised the section of the model rule [Section D.5(h)] addressing this
issue. Engineering assessment is recommended in the model rule as an
option to calculate process vent stream flow parameters for those streams
with a TRE index of 4.0 or greater.
F.6.3 Comment
Two commenters (IV-D-4, IV-D-6) said that Section D-5 of the CTG
document, "Performance Testing," should not be more restrictive than what
was proposed in the Enhanced Monitoring Guidelines for existing sources.
One commenter (IV-D-6) also suggested that an applicability paragraph be
added that excludes small sources.
Response: The draft Enhanced Monitoring Guidelines for existing
sources has not been proposed, making it difficult to comment on stringency
comparison between its requirements and those within this CTG. With
respect to the applicability paragraph, it was difficult to interpret if
commenter IV-D-6 was requesting an applicability cutoff for performance
testing or general facility applicability. However, it should be noted
that facilities with a very low capacity (less than 1 gigagram of chemicals
per year) were exempt from recommended RACT requirements. Additionally,
the CTG has been revised to recommend exempting certain individual streams
with low flow rates from TRE testing.
F.6.4 Comment; Two commenters (IV-D-3, IV-G-4) argued that requiring flow
indicators on individual streams prior to a control device is an excessive
cost that is not necessary in determining when a flow is diverted.
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One commenter (IV-D-3) recommended that the current reference to flow
indicators in D.6(a)(2), (b)(2), and (c)(l) be eliminated and replaced with
language similar to the following:
(i) Install a flow indicator at the entrance to any bypass line that
could divert the vent stream away from the control device to the
atmosphere; or
(ii) Secure the bypass line valve in the closed position with
car-seal, locked, or otherwise secured arrangement. A visual inspection of
the secured arrangement shall be performed once a month to ensure that the
valve is maintained in the closed position and that the vent stream is not
diverted through the bypass line.
Response: The EPA considers it very important to ensure that vent
streams are continuously vented to the flare (or other combustion device).
The primary intent of the flow monitoring recommendation in this CTG was to
provide a means for indicating when vent streams are bypassing the flare or
other combustion device. The flow indicators envisioned by the EPA were
intended to provide an indication of flow or no flow, and not to provide
quantitative estimates of flow rates.
The EPA has reevaluated the use of flow indicators in process vent
streams in light of the comments received for the SOCMI Reactor Process
NSPS as proposed. Because flow indicators located on the vent stream
between the emission source and the combustion device may be insufficient
to meet the intent of the CTG, the EPA has decided to alter the flow
indicator location. The CTG will be revised to indicate that the new flow
indicator location will be at the entrance to any bypass line that could
divert the vent stream before it reaches the combustion device. This
location would indicate those periods of times when uncontrolled emissions
are being diverted to the atmosphere. In those instances when the vent
stream is rerouted to another combustion device, a performance test would
need to be conducted on the second combustion to determine if it meets the
control requirements.
In some situations, there may be no bypass lines that could divert
the vent stream to the atmosphere. In these cases, there will be no flow
indicator recommendation. Language similar to the commenter's suggested
paragraph (ii) have been added to the CTG document. In addition, records
that show an emission stream is hardpiped to a combustion source are
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sufficient to demonstrate that the entire flow will be vented to the
combustion device. Other piping arrangements can be used, but flow
indicators located in any bypass line that could divert a portion of the
flow to the atmosphere, either directly or indirectly, become necessary.
If the piping arrangement for the process changes, then it is recommended
that the facility revise and retain the information.
The CTG was revised to suggest a flow indicator be equipped to
indicate and record whether or not flow exists at least once every
15 minutes. Because the monitor collects flow or no flow data on a
continuous basis, this additional recording would not be an additional
burden. If an owner or operator believes that an alternate recording
frequency or placement of a flow indicator is equally appropriate, then the
owner or operator can petition the State regulating agency.
F.6.5 Comment: One commenter (IV-D-1) said that the requirement that
temperature monitors be equipped "with strip charts" is too narrowly drawn.
The commenter pointed out that many instrument systems in the modern
chemical plant are computer driven and the recordkeeping is not via the
"old" strip chart method. The commenter suggested that the EPA require
continuous temperature monitoring, without a reference to the recordkeeping
mode selected by the source.
Response: The temperature monitoring recording requirements have
been revised, omitting any specific reference to a strip chart.
F.6.6 Comment: One commenter (IV-D-1) noted that on page D-9 of the draft
CTG, subparagraphs (a)(2), (b)(2) and (c)(l), require the installation of a
"flow indicator" on the vent stream to the control device. The commenter
emphasized that difficulties were encountered when attempting to comply
with similar requirements promulgated in the NSPS for air oxidation unit
processes and distillation operations. Specifically, the vent streams from
the affected distillation systems were hardpiped to a common flare header
with no means to automatically divert the vent stream to the atmosphere.
Each system had a nitrogen purge on its vent stream to the flare header to
control plugging caused by the polymerization of organics. The continuous
nitrogen purge precludes accurate measurement of vent stream flow to the
flare. The commenter suggested the problem may be widespread, noting that
a number of organic compounds will polymerize under the right set of
conditions. In addition to causing line pluggage, the commenter added that
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polymerization can also plug flow measuring devices, negating any
opportunity to select appropriate instrumentation. The commenter then
recommended adding a provision to this CTG that allows an appropriate
compliance alternative method for flow indication, with a reference to the
means by which a source could seek approval.
Response: The paragraphs cited in the comment contain a discussion
about the need to monitor the flow of streams before they are joined with
similar streams to a common control device. As a result of public comments
from this CTG and the distillation operations NSPS, these paragraphs have
been deleted from the final CTG document for two reasons: (1) the EPA is
no longer requiring that similar vent streams be combined due to technical
and safety concerns that may exist at some facilities (see response to
Comment F.3.5), and (2) the EPA has revised the purpose of flow indicators
so that they now continuously monitor the presence, not the extent, of vent
stream flow. Please refer to the response to comment number F.6.4 to
determine how the flow indicator section is being revised in the CTG. The
owner or operator can petition the State agency if it is felt that an
alternate method for flow indication should be conducted.
F.6.7 Comment; One commenter (IV-D-1) cited a significant recordkeeping
burden in complying with requirements promulgated in the NSPS for air
oxidation processes and the NSPS for distillation operations, and that the
CTG contains the same recordkeeping requirements. The commenter then
recommended that the source be allowed to select an annual performance test
as an alternative means of compliance.
Response: Conducting an annual performance test in lieu of the
required reporting requirements is not an appropriate alternative to
monitoring a process parameter. An annual performance test would not
indicate compliance through the year. The reporting and recordkeeping
requirements provide a means of documenting monitoring compliance on a
continuous basis and allow the source to demonstrate its continuous ability
to meet the standard.
F.6.8 Comment: One commenter (IV-D-3) noted that the reporting
requirements for the control and recovery devices in Section D.7(b) of the
CTG document require exceedance reports when temperatures or flows deviate
by more than a set level. The commenter further noted that current
interpretations of reporting requirements have identified situations where
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"deviations" require reporting, even when the regulated vent stream has
been shut down for maintenance and a vent is not actually flowing to the
control or recovery device. The commenter requested that language be added
to ensure that this reporting is required only during those periods when a
vent stream is actually flowing to the control or recovery device.
Response: The exceedance reporting requirement section of the CTG is
being revised. The final document will incorporate the language for these
requirements from the draft Enhanced Monitoring Guideline.
F.7 CONTROL TECHNOLOGY
F.7.1 Comment: Several commenters (IV-D-5, IV-D-6, IV-G-6, IV-G-7,
IV-G-8) argued that RACT should not be limited to combustion control
devices. One commenter (IV-G-8) suggested that rather than choosing
combustion devices or the most widely applicable control technique and
critically analyzing the limitations of alternative methods, the CTG should
point out applications or guidelines that indicate when use of each
technique is appropriate. The commenter was also disappointed that the EPA
had chosen to emphasize control devices that destroy rather than recover
solvents, noting that this decision seemed to be a counterproductive
solution to pollution prevention.
Three commenters (IV-D-5, IV-G-6, IV-G-7) recommended that catalytic
oxidation be recognized as an acceptable control alternative. By excluding
catalytic oxidation in the CTG, one commenter (IV-D-5) expressed concern
that the EPA is unnecessarily limiting its use since the lengthy approval
process required for alternative controls effectively precludes their use
within the defined compliance time limit.
Two commenters (IV-G-6, IV-G-7) provided data to support the
conclusions that modern catalytic oxidation systems perform well in almost
all circumstances, require minimum maintenance, minimize the formation of
secondary air pollutants, and commonly achieve values as high as
99.0 percent destruction for years without interruption. The commenters
requested that the CTG reflect this information when it is issued in its
final form.
One commenter (IV-G-7) cited personal experience that has shown that
catalytic oxidizers operate very successfully on SOCHI exhaust streams and
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recommended that the EPA delete the present statement In Section 3.1.4.3
and replace It with the following new language:
Catalytic oxidation is very effective in controlling VOC
emissions; it is an extremely flexible technology that can be
applied to a variety of SOCMI processes. It is basically a
chemical process which operates at much lower temperature than
thermal incineration and thereby minimizes fuel and other costs.
In addition, catalytic oxidation does not produce secondary air
emissions such as NOX and CO as occurs with thermal
incineration. High destruction efficiency (>98 percent) is
achieved through catalytic oxidation. Catalytic streams are
successfully operating on SOCMI vent streams. The SOCMI
exhausts are generally very clean and are therefore suitable for
catalytic systems. The SOCMI industry has been accustomed to
using a variety of process catalysts and are very skilled in
understanding and maintaining catalytic systems at maximum
performance. Sulfur resistant and halocarbon resistant
catalysts are available when needed.
One commenter (IV-D-6) stated that recovery devices and other
upstream process changes should be allowed to demonstrate RACT control.
Furthermore, to enable the use of these alternative pollution prevention
techniques, a suitable before control emission point must be defined. The
commenter recommended the following definition for before control
emissions:
Emissions after the first reflux/product recovery condenser, or
actual hourly average emission rate, after all control for the
years 1987 to present, whichever is greater.
Response: It is not the intent of this CTG to limit the owner or
operator to only one VOC control technology, many technologies are
presented in the CTG. For the purpose of calculating national impacts,
however, combustion via thermal incineration or flaring was chosen as the
control technology. This decision was based on the wide applicability and
ability of combustion devices to achieve 98 percent destruction efficiency
for SOCMI reactor and distillation vents. Additionally, even though
pollution prevention in the form of product or solvent recovery may be more
economical, these control techniques require modifications within the
process and are site specific, making it difficult to generalize these
modifications across the entire industry. Appropriate applications for
each control technology are given in Chapter 3.0 of the CTG. Catalytic
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incinerators are, in fact, recognized as acceptable alternative controls as
discussed in the CTG document.
The EPA appreciates the comment regarding Section 3.1.4.3 of the
document and has revised that section to incorporate some of the language
suggested.
F.7.2 Comment: One commenter (IV-D-3) said that the monitoring
requirements for carbon adsorbers should be modified to accommodate the
various types of regeneration systems currently in use. The commenter
recommended the following:
• All references to the use of "steam" for carbon adsorbers be
replaced with the term "regeneration stream." Changing to
this recommended language allows the owner or operator to use
either steam, a regeneration gas, heated nitrogen, or similar
technologies in the absorber system without requiring specific
waivers in a case-by-case basis.
• The recordkeeping and reporting requirements associated with
carbon absorber units refer only to "mass" flow measurements.
Rather than specifically referring to mass, we recommend that
either a mass or volumetric flow rate is appropriate.
Response: The EPA realizes that steam is not the sole method of
carbon adsorber regeneration. The CTG document has been revised to reflect
the commenters recommendations to modify the monitoring requirements for
carbon adsorbers.
F.7.3 Comment: One commenter (IV-G-5) expressed concern that two proposed
controlled techniques may pose worker safety or health hazards.
Specifically, the commenter named the combustion of VOC's in flares with
high velocity steam injection nozzles, and combustion of VOC's in boilers
or process heaters as potentially hazardous. The commenter noted that the
safety concern of high velocity steam injection nozzles is the increased
noise. Also, the variation in the flow rate and organic content of the
vent stream could lead to explosive mixtures with a boiler furnace.
Response: The proposed control techniques discussed in the CTG
document must be installed in compliance with Occupational Safety and
Health Administration (OSHA) requirements. Specifically, the flares must
be installed at such a height and location to minimize noise.
The venting of streams to boiler furnaces is listed as an alternative
control technology because it is not appropriate for all vent streams for
the exact reasons the commenter listed. As stated in the CTG, "variations
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in vent stream flow rate and/or heating value could affect the heat output
or flame stability...and should be considered when using these combustion
devices."
F.7.4 Comment: One commenter (IV-G-8) recommended that the discussion in
the CTG regarding condensation as an emission control technique needs
clarification.
Regarding Section 3.2.3.1, the commenter noted that
chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons can
be used in single stage or cascade cycles to reach condensation
temperatures below -73 °C (-100 °F), and liquid chillers using d-limonene
are capable of reaching temperatures below -62 °C (-80 °F).
With reference to Section 3.2.3.2, the commenter stated that
condenser efficiencies are frequently in excess of 95 percent, with
recovery by condensation working particularly well for low flow rates (less
than 2,000 cubic feet per minute [cfm]) and high VOC concentration (greater
than 5,000 ppmv). The commenter said that it is below the 5,000 ppmv
concentration level that the recovery efficiency of condensation drops
below 95 percent, and, furthermore, since condensation is not recommended
for use in applications involving concentration levels below 5,000 ppmv, it
does not make sense for the CTG to state that "efficiencies of condensers
usually vary from 50 to 95 percent."
Regarding Section 3.2.3.3, the commenter requested that the CTG
document state that condensation is applicable in many cases where other
control methods are not, including when lower explosion limits are too
high, when flow rates are too low; and when recovery rather than
destruction is required.
Response: The ranges listed in the CTG document (e.g., "below
-34 °C") include the specific examples cited by the commenter.
In Section 3.2.3.2 of the draft CTG, it is stated that the condenser
efficiency ranges depend on the flow parameters of the vent stream and the
operating parameters of the condenser. A statement has been added to the
CTG explaining that the higher efficiencies are expected for the low flow
(less than 2,000 cubic feet per minute [cfm]), high VOC concentration
(greater than 5,000 ppmv) streams. Finally, the CTG document has been
revised to state those cases where condensation is applicable and other
control methods are not.
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F.8 EDITORIAL
F.8.1 Comment: Two commenters (IV-D-6) recommended that the introduction
state clearly what sources are included and excluded by this CTG,
preferably in the opening paragraph.
Response: Chapter 1.0 of the CTG document has been revised to
incorporate a discussion of the applicable chemicals.
F.8.2 Comment. Four commenters (IV-D-3, IV-D-5, IV-D-6, IV-G-2) observed
that the flow rate cutoffs do not appear to be consistent, and requested
additional clarification. The commenters noted that the flow rate cutoff
in D.2(b)(3) is 0.011 scm/min (0.4 scfm), but the RACT summary on page 6-7
refers to the presumptive norm for RACT by requiring controls on streams
with a flow rate greater than 0.1 scfm.
Response: The units listed in D.2(b)(3) contained a typographical
error in the draft CTG document; however, this comment is no longer of
concern because the low flow cutoff for individual streams will be
calculated by determining the flow rate which identifies those streams with
a TRE index less than or equal to 1.0 when the stream characteristics from
the data base are inserted into the TRE equation. Furthermore, the
comparison of this number with the flow and concentration cutoff is no
longer of concern because the latter is being replaced with the TRE index
equation to determine applicability.
F.8.3 Comment: Several commenters (IV-D-3, IV-D-5, IV-D-6, IV-G-2) said
that in Section D.6 of the CTG, paragraph (a)(l), the temperature
monitoring requirements for incineration appear to be incomplete and
additional language (e.g., ±1 percent of temperature) is necessary.
Response: The CTG document has been revised to reflect this comment.
F.8.4 Comment; Two commenters (IV-D-4, IV-D-6) argued that the definition
of "total organic compounds" should be changed to exclude all compounds
accepted by the EPA as photochemically nonreactive.
Response: The EPA agrees with this comment. The current, updated
list of compounds considered photochemically nonreactive by the
Administrator has been incorporated into the document (see page D-5).
F.8.5 Comment: One commenter (IV-D-3) requested that the use of the term
"recovery device" be clarified. The commenter noted that the current
recovery device definition states that the equipment is capable of and used
for the purpose of recovering chemicals for use, reuse, or sale. The
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commenter emphasized that situations exist where the recovered material
from an absorber or condenser does not technically meet the recovery device
definition and it would not be subject to the monitoring and reporting
standards of the rule. In addition, the commenter stated that if the
concentration at the outlet vent of the condenser falls below the
concentration and flow cutoff, and if it is the only vent for the process,
then only minimum recordkeeping applies. The commenter asserted that this
type of "recovery device" also meets the intent of the rule and that many
compliance interpretation issues could be eliminated by revising the
definition. The definition recommended by the commenter is "...an
individual unit of equipment, used for the purposes of recovering chemicals
for use, reuse, sale, or treatment."
Response: The EPA appreciates this comment and the CTG document has
been revised to reflect this comment.
F.8.6 Comment: One commenter (IV-D-3) pointed out that the text that
identifies the examples in Figures 2-6 and 2-7 does not currently match the
diagrams.
Response; Figures 2-6 and 2-7 represent specific examples of a
direct reactor process vent and a recovery vent applied to the vent stream
from a liquid phase reactor, respectively. More specifically, Figure 2-6
presents a schematic of nitrobenzene production venting to the atmosphere,
whereas Figure 2-7 depicts an alkylation unit process used to produce
ethyl benzene. The EPA believes the figures do correspond to the text. The
EPA invites the commenter to call the EPA for further clarification if this
is still unclear.
F.8.7 Comment: Two commenters (IV-D-5, IV-G-2) suggested that the
Chemical Abstracts Service (CAS) number of the individual chemicals listed
in Appendix A should be provided.
Response: The EPA agrees with this comment and the CTG document has
been revised to reflect this comment.
F.8.8 Comment; One commenter (IV-D-6) noted that in the Ks definition in
the middle of page D-6, Ks should be Kg.
Response: The EPA agrees with this comment and the document has been
revised to reflect this comment.
F.8.9 Comment; One commenter (IV-D-1) recommended that the definition of
"product" would be clearer if the EPA would define it as "any compound or
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chemical listed in Appendix A which is produced as that chemical for sale
as a final product, by-product, co-product, or intermediate or for use in
the production of other chemicals or compounds."
Response: The EPA agrees with this comment and the CTG document has
been revised to reflect this comment.
F.8.10 Comment: One commenter (IV-D-1) said that the definition of
"affected facility" would be easier to follow if it were changed as
follows: "an affected facility is an individual reactor process or
distillation operation with its own individual recovery system (if any) or
the combination of two or more reactor processes or distillation operations
and the common recovery system they share." The commenter noted that
reactor processes and distillation columns are not single pieces of
equipment, but embrace several other components which are considered part
of the system. The commenter suggested that rewording this definition
would help make this distinction more apparent to the reader.
Response: The EPA agrees with this comment and the CTG document has
been revised to reflect this comment.
F.8.11 Comment: One commenter (IV-D-1) noted that the CTG states that of
the three possible emission limitation formats, the regulatory agency
should consider applying the "percent reduction format" since the EPA
believes it "best represents performance capabilities of the control
devices used to comply with the RACT regulation." The commenter suggested
that there are other opportunities which would present themselves for using
one of the other two formats. The commenter then recommended that the
wording at the top of page 7-4 be changed in the second line by eliminating
"...are not preferred because they " The commenter noted that this does
not change the general intent of the statements contained on the page, but
does remove a direct inference that the other two formats should not be
used.
Response: This comment is no longer applicable because the
applicability format has been revised to incorporate the TRE index
equation. The CTG now recommends reduction of VOC emissions until the TRE
index is greater than one.
F.8.12 Comment; One commenter (IV-G-2) requested that any deviation from
the list of chemicals established in the corresponding NSPS for reactor
processes and distillation operations be explained in the CTG.
F-27
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Response: The list of applicable chemicals for this CTG correspond
to all appropriate chemicals addressed by previous NSPS plus chemicals in
the SOCHI source category. Any deviations in the list of chemicals in this
CTG from the list presented in previous NSPS result from the inclusion of
SOCMI chemicals.
F.8.13 Comment: One commenter (IV-G-7) recommended the following language
changes in Section 3.1.4.1:
• Paragraph 1, sentence 5, change to read: "Combustion catalysts
include palladium and platinum group metals, manganese oxide,
copper oxide, chromium and cobalt."
• Paragraph 3, sentence 1, charge to read: "The operating
temperatures of combustion catalysts usually range from 500 °F
to 800 OF."
• Paragraph 3, sentence 3, change to read: "Temperatures greater
than 1,350 °F may result in shortened catalyst life." Delete
the rest of the original sentence because it is not true that
the catalyst or substrate will evaporate or melt at higher
temperatures (>1,200 °F). In order for a metal substrate to
melt the temperature must exceed 2,600 °F."
• Paragraph 3, add the following after the last sentence:
"Materials accumulated on the catalyst can be removed by
physical or chemical means, thus restoring the catalyst
activity to its original (fresh) level. Condensed organics
accumulated on the catalyst can be removed with thermal
treatment.
The commenter also stated that not all of the poisons listed in
paragraph 3 of Section 3.1.4.1 are detrimental to VOC catalysts. The
commenter suggested that masking of the catalyst by particulate or
carbon-based materials is reversible, and catalysts are commercially
available to handle many of the poisons listed, including sulfur,
halocarbons, and phosphorous.
Response: The EPA agrees with all these comments and will revise the
CTG document to reflect them.
F.8.14 Comment: One commenter (IV-G-7) said that the example cited in
Section 3.1.4.2 is an oversimplification and is not VOC species specific.
The commenter stated that at 840 °F and a space velocity of 30,000/seconds
(the example shown), many VOC's can be reduced by 99 percent or more with
catalytic oxidation technology.
F-28
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Response: The EPA believes that the commenter cited an example that
verifies the referenced numbers in the document. The CTG document stated
that "catalytic oxidizers have been reported to achieve efficiencies of
98 percent or greater," and the 99 percent reduction reported by the
commenter does fall within the 98 percent or greater range.
F.8.15 Comment. One commenter (IV-G-7) recommended that sentence 2 of
paragraph 2 in Section 3.3 be deleted. The commenter stated that there are
not technical obstacles preventing catalytic oxidation from achieving at
least 98 percent destruction efficiency, and that this level of control is
becoming the rule rather than the exception.
Response; The sentence the commenter is referring to states that,
with the exception of catalytic oxidizers, the other combustion devices
listed are applicable to a wide range of vent streams. The EPA agrees with
this comment and has revised the CTG document to reflect this comment.
F.8.16 Comment: One commenter (IV-G-7) requested that several statements
in Section 6.2 of the draft CTG be modified to present a more neutral
treatment of catalytic oxidation and to ensure that this technology is not
excluded from consideration as an available control technology.
Response: The EPA has revised the CTG document to reflect this
request.
F-29
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing]
1. REPORT NO.
EPA-450/4-91-031
3. RECIPIENT'S ACCESSION NO
4. TITLE AND SUBTITLE
Control of Volatile Organic Compound Emissions from
Reactor Processes and Distillation Operations Processes
in the Synthetic Organic Chemical Manufacturing Industry
5. REPORT DATE
August
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8 PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
10 PROGRAM ELEMENT NO
11 CONTRACT/GRANT NO
68-D1-0117
12. SPONSORING AGENCY NAME AND ADDRESS
Director, Office of Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
15 SUPPLEMENTARY NOTES
16. ABSTRACT
This report provides the necessary guidance for State and local air pollution
authorities to control emissions of volatile organic compounds (VOC's) from
reactor processes and distillation operations in the synthetic organic chemical
manufacturing industry. Emissions are characterized and VOC control options are
described. A reasonably available control technology (RACT) is defined for process
vents from reactor processes and distillation operations. Information on the cost
of control, environmental impacts of the controls and a "model rule" are provided.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATi Field/Group
Air Pollution
Pollution Control
Volatile Organic Compounds
Synthetic Organic Chemical Manufacturing
Industry
Reactor Processes
Distillation Operations
Process Vents
Air Pollution Control
Synthetic Organic Chemica
Manufacturing Industry
1
18. DISTRIBUTION STATEMENT
Release Unlimited
19 SECURITY CLASS
Unclassified
7»J Reports
• I. NO. OF PAGES
275
20 SECURITY CLASS (Tins page/
Unclassified
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
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