4>EPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 79-ISC-7
August 1979
Air
Industrial Surface
Coating Cans
Emission Test Report
American Can
Forest Park, Georgia
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INDUSTRIAL SURFACE COATING CANS
EMISSION TEST REPORT
AMERICAN CAN
FOREST PARK, GEORGIA
Prepared For:
Mr. R.T. Harrison
Tech. Manager
ESED/EMB
Office of Air Quality Planning
and Standards
Environmental Protection Agency
Contract No. 68-02-2820
Work Assignment 13
Prepared By:
Samuel S. Cha
Task Manager
S. Dexter Peirce
Environmental Engineer
TRC Contract 1170-E80
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TABLE OF CONTENTS
SECTION
1.0
2.0
INTRODUCTION
CONCLUSIONS
3.0
4.0
PROCESS DESCRIPTION
5.0
4.1
4.2
4.3
4.4
4.5
4.6
4.7
5.1
5.2
5.3
METHODOLOGY
Coating-Solvent Mixture - Determination of Its
Usage and Composition
Determination of Coating Applied
Determination of Moisture Losses
Sheet Counting
Oven Exhausts Flow Rate Measurement
Volatile Organic Compound (VOC) Measurements
Oxygen and Carbon Dioxide Measurements . . . .
RESULTS AND DISCUSSIONS
Coating and Solvent Used and Dried Coating Applied
Emission Measurements
Material Balance
4
7
7
8
9
10
10
10
11
12
12
14
16
APPENDICES
A
B
VOC CONTENT OF COATING .
PROCEDURE FOR MEASUREMENT OF TOTAL GASEOUS ORGANIC
COMPOUND EPA REFERENCE METHOD 25
"Determination of Total Gaseous Nonmethane Organic
Emissions as Carbon" Manual Sampling and Analysis
Procedure FR/Vol. 44, No. 195, October 5, 1979
F
G
PROCEDURE FOR DIRECT MEASUREMENT OF TOTAL GASEOUS
ORGANIC COMPOUNDS USING A FLAME IONIZATION ANALYZER
Published in "Measurement of Volatile Organic Compounds"
EPA-450/2-78-041 OAQPS No. 1.2-115, October, 1978
1. Coating-Solvent Usage Date
2. Sheet Counting Data
MASS OF COATING APPLIED ON SHEETS FIELD DATA
1. By Weighing. Corrected for metal sheet moisture
weight losses.
2. By Canco Resistance Gauge
FLOW RATE MEASUREMENT RESULTS
EMISSIONS MEASUREMENT RESULTS USING FLAME IONIZATION
ANALYZER
EMISSION MEASUREMENT RESULTS USING EPA REFERENCE
METHOD 25 (TGNMO)
1. Field Data Sheets
2. Analysis Results
-11-
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LIST OF FIGURES
FIGURE
3-1
TABLE
5-1
5-2
5-3
5-4
PAGE
Sheet Base Coating Emissions 5
LIST OF TABLES
PAGE
Coating - Solvent Mixture and Recovered Base
Coating Operation - Three Piece Can Plant,
October, 1979 13
i
Emission Measurement Results - TGNMO Base
Coating Operation, 3 Piece Can Plant,
October, 1979 15
Comparison of TGNMO and FIA Mass Emission
Results Oven Exhaust, Base Coating Operation
3 Piece Can Plant, October, 1979 17
VOC Material Balance Base Coating Operation
3 Piece Can Plant, October, 1979 18
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1.0 INTRODUCTION
As Work Assignment 13 of Contract 68-02-2820, the Office of Air Quality
Planning and Standards, Environmental Protection Agency (OAQPS, EPA) has
assigned TRC Environmental Consultants, Inc., to perform a Volatile Organic
Compound (VOC) material balance study of a base coating operation in a
three-piece can manufacturing plant. Results from this study will provide
EPA-OAQPS with additional background information to develop New Source
Performance Standards (NSPS) for the can manufacturing industry.
A base coating operation in a three-piece can manufacturing plant,
operated by American Can Company at Forest Park, GA, was selected by EPA-OAQPS
as the object of the material balance evaluation. The tests were conducted
during the week of October 8, 1979 by TRC staff along with Mr. William King of
Research Triangle Institute, which is also a contractor of EPA. and an EPA
staff member, Mr. R. T. Harrison.
A total of six material balance runs were conducted. For each run,
coating-solvent usage, dry coating applied on the can sheets, and volatile
organic compound emissions from oven exhausts were quantified. Volatile
organic compound material balances for the process were then derived. This
report summarizes TRC's approach, test results and conclusions.
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2.0 CONCLUSIONS
For the six sets of data collected, the weiqht percentage of the total
coating-solvent used which remained on the cured sheets as dry coating ranged
from 42 to 55 weight percent using the weighed sheet method and ranged from 53
to 58 weight percent using the electrical gauging procedure. Oven Volatile
Organic Compound (VOC) emissions ranged from 34 to 55 weight percent of the
total coating-solvent used when expressed as propane. Because these data are
derived from the TGNMO data which expresses VOC emissions as carbon, propane
was chosen as a surrogate' compound to estimate the molecular weight to carbon
ratio of the VOC being emitted. Using propane as the surrogate compound and
the dry coating weights based on weighing the sheets results in an unaccounted
weight loss ranging from 3 to 18 weight percent of the total coating-solvent
used. Use of the dry coating weight from the electrical gauging procedure
would result in a smaller unaccounted for weight loss (except for run 5) .
Based on the coating manufacturer's specifications for the coating used, 46
%
weight percent of the coating was solvent. Assuming this solvent to be all of
the VOC in the coating, then the percentage of the VOC in the coating which is
accounted for in the oven VOC emissions (including the cooling zone) ranges
from 74 to 79 weight percent for five of the six runs when the oven VOC
emissions are reported with propane as the surrogate compound. (For run 1,
the oven emissions appear to be about 20 percent greater than estimated to be
available in the coating.)
Finally, additional solvent was used to provide the proper viscosity of
the coating during application. This additional solvent was not accounted for
in the above calculations. Data from run 1 and 2 indicate that 6 to 7 weight
percent pure solvent was added to the coating-solvent mixture. The individual
solvent and coating weights were not recorded for runs 3 through 7. For run 2,
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this would decrease the percentage of VOC emission accounted for in the oven
from 79 percent to 74 percent. (For run 1, the oven VOC emissions would still
be greater than estimated to be available in the coating-solvent used by about
12 percent.)
Run 7 was conducted with no coating being applied to the sheets. There
was a substantial decrease in VOC emissions from the oven exhaust but no
significant change in the VOC emission from the cooling zone exhaust of the
oven. It is assumed that most of these emissions represent residue left in
the oven from previous coating, however, this assumption is not confirmed.
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3.0 PROCESS DESCRIPTION
The base coating operation tested consists of the application and drying
of a white base coat onto metal sheets prior to their being printed and formed
into can bodies. The nominal size of a sheet is 42 in. x 35 in. The coating
operation can be run at a maximum rate of 100 sheets per minute. Each sheet
is first fed onto a conveyor where it is introduced to the coating
application. As shown in Figure 3-1, the application roller applies the white
base coat to the top of the sheet and the cleaning roller cleans the bottom of
the sheet with backwash solvent. Both the application roller coating tray and
the cleaning roller backwash solvent tray are constantly supplied with, and
recirculate, the coating and cleaning solvent from two reservoir tanks. These
two tanks are refilled and adjusted for proper viscosity as necessary. The
sheets are counted by a counter before the coating application.
The coated sheets travel across a six foot flash-off zone and enter a
wicket oven where they are dried. The wicket oven consists of five zones.
The first three zones are heated and used to dry the coated metal sheets,
followed by a cooling zone where the coated and dried sheets are allowed to
cool before exiting the oven. There is also a preheat zone underneath the
other four zones where empty wickets are heated and returned to the front
(coater) end of the coating line. Upon exiting the oven, the coated sheets
are recounted by three different counters, then stacked and removed for
further processing. The air is taken into the oven through an air intake
stack on the roof. Air is preheated through a heat exchange duct arrangement
within the cooling zone. Part of the air is sent through the oven from the
rear end of the oven toward the front end (near the coater) of the oven, and
is then vented to the atmosphere through an oven exhaust stack. The other
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FXHAUST
EXHAUST
I
Ol
I
SOLVENT
ADDITION
SOLVENT/COATING
TANK
EXHAUST
APPLICATION
,
ROLLER
SHEET (PLATE)
FEEDER
SOLVENT ADDITION
SOLVENT TANK
I
SHEET (PLATE)
STACKER
FIGURE 3-1: SHEET BASE COATING EMISSIONS
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portion of the air is sent through the cooling zone and then to the cooling
zone exhaust stack. The temperature of air in each zone is controlled and
o
monitored on a continuous basis, and is maintained at approximately 400 F
for the first three zones.
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4.0 METHODOLOGY
The following sections present the methodology applied in determining a
material balance of VOC in the three-piece can base coating operation.
During the program, a total of seven runs were completed. Each run
consisted of approximately 1900 sheets and lasted approximately thirty
minutes. Runs 1 through 6 were typical runs, during which sheets were coated
and dried. For the purpose of gathering background information, a seventh run
was conducted, during which sheets were sent through the oven without coating
applied.
4.1 Coating-Solvent Mixture - Determination of Its Usage and Composition
Coating-solvent usage was determined by weighing the coating-solvent
mixture and backwash solvent before and after each run.
Prior to each run (1 through 6), the coating applicator was drained of all
coating-solvent mixture and backwash solvent. All coating material was then
mixed with make-up solvent to meet the viscosity specification. The initial
weights of the coating-solvent mixture and the backwash solvent were then
measured using a 0-1000 pound Toledo Scale.
During each run, no make-up solvent was added to either the
coating-solvent reservoir or the backwash solvent reservoir. After each run
was completed, the coating applicator was drained of all coating-solvent
mixture and backwash solvent and returned to the reservoir buckets. The final
weights of the coating-solvent mixture and the backwash solvent were measured
and recorded. The difference between the initial and final weights of the
coating-solvent mixture and the backwash solvent yields the coating-solvent
usage for the run.
-7-
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The VOC content of the coating has been estimated from the manufacturer's
specifications (see Appendix A). This has resulted in a conservative estimate
of VOC content of the coating since additional solvent was added to the
coating to adjust the viscosity of the coating. During runs 1 and 2 the
additional solvent added accounted for 6.5 and 5.5 weight percent of the
combined coating solvent mixture. For subsequent runs these individual data
were not recorded.
4.2 Determination of Dry Coating Applied
Selected sheets were weighed before and after the coating and drying
operation to determine the mass of dry coating applied to each sheet.
For each run (1 through 6) , thirty sheets were numbered with a grease
pencil and an initial mass was determined for each sheet. The sheets were
then returned to the sheet stack and were coated and dried as a normal run.
For runs 1 and 2, the preweighed thirty sheets were placed within the first
sheets in the stack to be coated. In runs 3 through 6, the preweighed sheets
were placed on line approximately half way through the stack (or run) . This
latter procedure was recommended by plant personnel who indicated that this
procedure should result in a more accurate determination of average dry
coating weight, since minor adjustments in coating thickness are normally
required at the start of a run. After the coating and drying operation, a
final mass was determined for each preweighed sheet. The difference between
the initial and final weights yielded the mass (weight) of coating applied per
sheet.
All sheet mass measurements were made using an Ohaus triple beam balance
having a capacity of 2610 grams. Prior to testing, the balance was checked
against a set of standard weights. The balance pan was also fitted with a
wire basket to facilitate the weighing of the sheets.
-8-
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The wire basket portion of the total tare weight, changed between initial
and final mass determinations. An adjustment was made to the average coating
applied, determined by weighing, according to the change in tare weight, by
addina the difference between the final and initial tare weights to the
calculated coating applied. For runs 1, 2 and 3 the long time ( 2 months)
between the initial and final mass determinations caused a difference in tare
weight of 1.95 gram which was added to the average coating applied determined
for each of the three runs.
A method that measures coating weight as a function of electrical
resistance, developed by Canco, was also used. For each of the thirty weighed
sheets, electrical resistances at five different positions on each sheet were
measured and expressed as mg per 4 sq. in. These five values were further
averaged and converted according to the size of sheets to derive the coating
weight per sheet.
4.3 Determination of Moisture Losses
To determine metal sheet weight losses, if any, due to moisture
evaporation during the drying operations, a blank run (run 7) was made.
During the blank run, all sheets were sent through the oven without first
being coated.
Before run 7, ten sheets were numbered with a grease pencil and an initial
mass was determined for each sheet. These preweighed sheets were then
introduced to the drying oven approximately midway through a run 7. Once the
preweighed sheets exited the drying oven and were allowed to cool, a final
mass was determined for each sheet. The difference between the intial and
final masses of each sheet yields the moisture loss per sheet.
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4.4 Sheet Counting
As briefly described in Section 3.0, several sheet counters are located at
the front end and the back end of the base coating operation line.
Readings of sheet counting at both ends were made and recorded. Since 30
testing sheets (for coating weight determination) were removed before the back
end sheet counters, the back end counter readings were always 30 sheets less
than the front end counter readings.
4.5 Oven Exhausts Flow Rate Measurement
Flow rate measurements were conducted at both the oven exhaust (at the
front end of the oven) and the cooling zone exhaust during each of the runs.
A standard type pitot and an inclined manometer were used and EPA
reference methods 1 and 2 were followed to determine flow rates. Temperature
of air flow was also measured by using a chromel-alumel thermocouple and a
potentiometer.
On the first day of the test program, all exhaust flow rates were checked
and the oven air flow was found out of balance, i.e., the air flow rate from
the cooling zone exhaust was much lower than its operating specifications.
Damper and fan adjustments were then made by plant personnel to balance the
oven flow according to design specifications, prior to starting the VOC
emission tests.
4.6 Volatile Organic Compound (VOC) Measurements
To measure the VOC emissions at the oven exhaust and the cooling zone
exhaust of the base coat drying oven, two different approaches were used.
They were:
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"Determination of Total Gaseous Non-Methane Organic Compounds as Car-
bon - Manual Method", known as the TGNMO method, or proposed EPA
reference method 25 (see Appendix B) . Samples were anisokinetically
drawn from the stack through a chilled condensate trap by means of an
evacuated gas collection tank. Total gaseous non-methane organics
(TGNMO) were determined by combining the analytical results obtained
from independent analyses of the condensate trap and evacuated tank
fractions. After sampling was completed, the organic contents of the
condensate trap were oxidized to carbon dioxide which was quantita-
tively collected in an evacuated vessel; a portion of the carbon di-
oxide was reduced to methane and measured by a flame ionization de-
tector (FID). A portion of the sample collected in the gas sampling
tank was injected into a gas chromatographic (GC) column to achieve
separation of the non-methane organics from carbon monoxide, carbon
dioxide and methane; the non-methane organics were oxidized to carbon
dioxide, reduced to methane and measured by FID. This analytical
work was conducted by TRC's subcontractor - Pollution Control Sci-
ence, Inc., of Miamisburg, Ohio.
"Direct Measurement of Total Gaseous Organic Compounds Using a Flame
Ionization Analyzer", (see Appendix C) . This method is known as FIA
or FID. A sample was drawn from the source through a heated sample
line and glass fiber filter to a flame ionization analyzer (FIA).
Ions formed in the combustion of a specific hydrocarbon compound in a
H2-O2 flame established a current that is approximately propora-
tional to the mass flow rate of the hydrocarbon to the flame. This
current was measured at two polarized electrodes, and was read out on
a potentiometric recorder and compared with a calibration curve based
on propane (C%g) . The results are reported as equivalents of
propane (C3Hg) or methane (CH,}) or Carbon (C) .
4.7 Oxygen and Carbon Dioxide Measurements
An integrated bag sample was taken at the oven exhaust during Run 7. Car-
bon dioxide and oxygen concentrations of the sample were determined using an
Orsat technique known as EPA Method 3. Data were used for the indication of
performance of the oven heat supplier burner.
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5.0 RESULTS AND DISCUSSIONS
5.1 Coating and Solvent Used and Dried Coating Applied
Coating and solvent usage was determined by weighing the coating-solvent
mixture and backwash solvent before and after each run. Results of these
weighings are listed in Appendix D.
Thirty (30) numbered sheets in each approximately 1900-sheet stack run
were weighed before and after the coating-drying operation to determine the
mass (weight) of coating applied to each sheet. Results of these weights are
listed in Appendix E. Results of the weight increase on each sheet were
averaged for each run, corrected for both tare weight and moisture loss during
drying. Each of the weighed 30 sheets per run were also measured by an
electrical resistance gauge to determine the mass of coating applied per
sheet. These measurements were made at five locations on each sheet. These
results are also listed in Appendix E. Table 5-1 summarizes the results in
Appendix D & E. As shown in Table 5-1 and Appendix E, the coating-solvent
usage for each 1900-sheet run ranged from 87.5 Ibs (39.7 kg) to 135.0 Ibs
(61.3 kg). After the two test runs on the first testing day (Oct. 10, 1979),
the coating line supervisor at the plant modified the application procedure to
increase the coating-solvent usage because the amount of coating-solvent used
in the first two runs was lower than the standard specification.
Table 5-1 also shows that the values of coating mass applied on each sheet
derived through two different measurement methods are different from each
other. The value derived by using the electrical resistance gauge was higher
than that derived by using the weighing technique, except for run 5. Since we
are not familiar with the calibration of the electrical gauge technique, the
values derived by using our weighing technique are used in further discussions.
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TABLE 5-1
COATING-SOLVENT MIXTURE USED AND RECOVERED
BASE COATING OPERATION
THREE PIECE CAN PLANT, OCTOBER, 1979
Coating Weight Applied
on Sheet (Ib) % Recovered
Coating-Solvent (D Derived by Derived by
Run # Usage (Ib) Weighing Gauging Weighing Gauging
A B C B/A
1(2), (3) 87.5 36.8 50.4 42
2(2), (3) 97.0 47.0 56.4 48
3 129.5 62.6 70.5 48
4 135.0 74.2 77.6 55
5 126.5 69.0 67.4 55
6 ' 110.8 54.8 61.0 49
C/A
58
58
54
57
53
55
(1)
(2)
(3)
Assumes that the weight gained by the backwash solvent during the run
is coating-solvent recovered from the applicator.
Process modifications were made by the plant after run 2 and prior to
run 3 to increase the coating usage.
During runs 1 and 2, the 30 test sheets used to determine the dry
coating weight were introduced near the beginning of the run; for
subsequent runs the test sheets were introduced later in the run to
obtain a better estimate of average coating weight applied since minor
process modifications are sometimes required at the start of a run.
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5.2 Emission Measurements
Flow rate measurements at both the oven exhaust and the cooling zone
exhaust are listed in Appendix F. Measurement results indicated that the flow
rate at the oven exhaust averaged approximately 4,500 SCFM, or 127 M /MIN,
and that the cooling zone exhaust averaged approximately 15,000 SCFM, or 425
M3/MIN.
Volatile organic compounds (VOC) measurement results using both the Flame
lonization Hydrocarbon Analyzer (FIA) and the Total Gaseous Non-methane
Organic (TGNMO or Method 25) are listed in Appendices G & H. Table 5-2
summarizes the flow rates and VOC measurement results derived by using the
TGNMO method. As indicated in the table, the oven exhaust emission averaged
25.48 Ibs (11.55 kg) as carbon among the 6 runs and ranged between 21.95 Ib
(9.95 kg) and 28.06 Ib (12.73 kg) as carbon. The cooling zone exhaust
emission averaged 9.80 Ib (4.44 kg) as carbon with a range between 4.85 Ib
(2.20 kg) and 16.39 Ib (7.43 kg) as carbon among the six runs. The total
emission, therefore, ranged from 28.83 Ib (13.07 kg) to 38.46 Ib (17.44 kg) as
carbon with an average of 35.28 Ib (16.00 kg) per run.
Since coating-solvent usage data (see 5.1) are based on the weight of
actual material but not the weight of the carbon contained in the material, a
conversion is made to convert the emission mass of carbon to the emission of
propane (it is realized that even the propane basis may not be
representative). After the conversion, the total emission ranges from 35.24
Ib (15.97 kg) to 47.01 Ib (21.32 kg) for the six runs.
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TABLE 5-2
EMISSION MEASUREMENT RESULTS - TGNMO
BASE COATING OPERATION, 3 PIECE CAN PLANT
OCTOBER, 1979
Run
1
1
2
3
Ul
1 4
5
6
7*3
AVG
Run
Time
Min.
30
28
27
34
37
39
33
( Run 1 to
Flow
SCFM
4750
8
4510*
4500
4460
3840
4292
4443
Run 6)
Oven Exhaust
Cone . * 6
Rate (C )
M /M MG/L
134.52 2.378
2.583
127.72 2.783
127.44 3.570
3.294
Emission
Mass Emission
(Carbon)
GM Ib
9597
10424 ,
AVG 10010*
9953
12284
11334
AVG 11809*
126.31 2.824*^ 12128
1.446*
108.75 3.163
121.55 2.425
2.932
125.83 0.267
12727
11496
13899
AVG 12698*
1109
11554
21.16
22.98 j
22.07*
21.95
27.09
24.99
26.04*
26.74
28.06
25.34
30.65
27.99*
2.45
25.48
Cooling
Flow Rate
SCFM M /M
17700*7 501.61
17700 501.61
13550 383.74
13680 387.42
16480 466.71
14960 423.67
14000 396.48
Zone Exhaust
Cone.* 6
(C )
MG/L
0.494
0.222
0.445
0.371
0.333*5
0.133
0.280
0.333
Emission
Mass Emission
(Carbon)
GM Ib
7434 16.39
3118 6.88
4611 10.17
4887 10.77
4421*5 9.75*5
2198 4.85
3663 8.08
4445 9.80
Total
As
KG
17.44
13.07
16.42
17.02
17.15
14.90
4.77
16.00
Emission
Carbon
Ib
38.46
28.83
36.21
37.51
37.81
32.84
7.22
35.28
Total Emission
As C H *4
KG 3 8 Ib
21.32 47.01
15.97 35.24
20.07 44.26
20.80 45.85
20.96 46.21
18.21 40.14
5.83 8.82
19.56 43.12
•^Duplicate samples.
^Duplicate samples, second sample was deleted due to inconsistence with other data.
run, metal sheets only, no coating applied. Emission represents residues remained in the oven.
* Total emission as C, H. = Total emission as Carbon x —
3 8 36
*5No data, average of other runs were used.
*6TGNMO results, (see Appendix H)
*'fiun 2 flow rate use.
*8Run 2C flow rate used.
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Results derived by using FIA method (at oven exhaust only) are summarized
in Appendix G. When evaluating FIA results, it was found that the analyzer
still indicated that a certain amount of emission was present even though the
coated sheets had left the oven. It was believed that both the gaseous
organic residue in the oven and the condensed organic compound in the sample
o
line (sample line temperature; 250 F) were the major contributors of the
observed emission "tail". Mass emission calculations (both as C,Hg and as
carbon) were made to quantify both with the "tail" and without the "tail".
Results are listed in the summary table of Appendix G. These calculations
show that the above mentioned emission "tail" would account for 15 - 30% of
the total emission (except Run #5, in which the emission tail contributed 47%
of total emission).
While comparing TGNMO and FIA results at the oven exhaust, TGNMO result
averaged 23.1% higher than FIA results without the emission "tail". When
emission tails are included, FIA results are higher in 4 runs and lower in 2
runs (Runs II and #3). In the 6 runs, TGNMO results generally agree with FIA
results with the emission tail; the differences are within ± 35% of the TGNMO
results. Table 5-3 shows the comparison. (For material balance, only TGNMO
results were used.)
5.3 Material Balance
Table 5-4 summarizes the VOC material balance of a base coating
operation. For the six sets of data collected, the weight percentage of the
total coating-solvent used which remained on the cured sheets as dry coating
ranged from 42 to 55 weight percent using the weighed sheet method and ranged
from 53 to 58 weight percent using the electrical gauging procedure. Oven
Volatile Organic Compound (VOC) emissions ranged from 34 to 54 weight percent
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TABLE 5-3
COMPARISON OF TGNMO AND FIA MASS EMISSION RESULTS
OVEN EXHAUST, BASE COATING OPERATION
3 PIECE CAN PLANT, OCTOBER, 1979
FIA Results
TGNMO W W/0 % Ratio
Results Emission Tail FIA/TGNMO
Run as Carbon as Carbon W W/0
# Ib Ib Ib Emission Tail
1 20.07 20.67 17.01 93.7% 77.1%
2 21.95 26.12 19.24 119.0% 87.7%
3 26.04 22.53 18.59 86.5% 71.4%
4 26.74 29.12 21.80 108.9% 81.5%
5 28.06 37.29 21.36 132.9% 76.1%
6 27.99 28.07 20.33 100.3% 72.6%
AVG (1-6) 25.48 27.30 19.72 107.1% 77.4%
% Difference
FIA VS TGNMO
W W/0
Emission Tail
-6.3% -22.9%
19.0% -12.3%
-13.5% -28.6%
8.9% -18.5%
32.9% -23.9%
0.3% -27.4%
+7.1% -22.6%
*Percent difference (FIA vs TGNMO) = FIA ~ TGNMO x 100%
TGNMO
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TABLE 5-4
VOC MATERIAL BALANCE
BASE COATING OPERATION
3 PIECE CAN PLANT, OCTOBER, 1979
Coa t ing-SoIven t
Usage
Total Oven
VOC Emission
Coating
Applied
Run (as Actual Material)
# lb
1 87.5
(100%)
2 97.0
(100%)
3 129.5
(100%)
4 135.0
(100%)
5 126.5
(100%)
6 110.8
(100%)
(As C3H8)
lb
47.0
(54%)
35.2
(36%)
44.3
(34%)
45.9
(34%)
46.2
(37%)
39.8
(36%)
(as Actual Material)
lb
36.8
(42%)
47.0
(48%)
62.6
(48%)
1 74.2
(55%)
69.0
(55%)
54.8
(49%)
Difference*
lb
3.7
(4%)
14.8
(15%)
22.6
(18%)
14.9
(11%)
11.3
(9%)
16.2
(15%)
*Difference = Coating-Solvent Usage - Oven Emissions- Coating Applied
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of the total coating-solvent used when expressed as propane. Because these
data are derived from the TGNMO data which expresses VOC emissions as carbon,
propane was chosen as a surrogate compound to estimate the molecular weight to
carbon ratio of the VOC being emitted. using propane as the surrogate
compound and the dry coating weights based on weighing the sheets results in
an unaccounted weight loss ranging from 4 to 18 weight percent of the total
coating-solvent used. Use of the dry coating weight from the .electrical
gauging procedure would result in a smaller unaccounted weight loss (except
for run 5). Based on the coating manufacturer's specifications for the
coating used, 46 weight percent of the coating was solvent. Assuming this
solvent to be all of the VOC in the coating, then the percentage of the VOC in
the coating which is accounted for in the oven VOC emissions as propane
(including the cooling zone) ranges from 74 to 79 weight percent for five of
the six runs. (For run 1, the oven emissions appear to be about 20 percent
greater than estimated to be available in the coating.)
Finally, additional solvent was used to provide the proper viscosity of
the coating during application. This additional solvent was not accounted for
in the above calculations. Data from run 1 and 2 indicate that 6 to 7 weight
percent pure solvent was added to the coating-solvent mixture. The individual
solvent and coating weights were not recorded for runs 3 through 7. For
run 2, this would decrease the percentage of VOC emission accounted for in the
oven from 79 percent to 74 percent. (For run 1, the oven VOC emissions would
still be greater than estimated to be available in the coating-solvent used by
about 12 percent.)
Run 7 was conducted with no coating being applied to the sheets. There
was a substantial decrease in VOC emissions from the oven exhaust but no
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significant change in the VOC emission from the cooling zone exhaust of the
oven. It is assumed that most of these emissions represent residue left in
the oven from previous coating, however, this assumption is not confirmed.
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