United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 80-BYC- 3
March 1981
Air
Benzene
Coke Oven By-Product
Recovery Plants
Emission Test Report
Wheeling-Pittsburgh
Steel Corporation
Monessen, Pennsylvania
-------
SET 1957 02 1280
BENZENE SAMPLING PROGRAM
AT COKE BY-PRODUCT RECOVERY PLANTS:
WHEELING-PITTSBURGH STEEL CORPORATION
MONESSEN, PENNSYLVANIA
EPA Contract 68-02-2813
Work Assignment 48
ESED Project No. 74/4J
Prepared For:
Mr. Daniel Bivins
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emission Measurement Branch, ESED, MD-13
Research Triangle Park, North Carolina; 27711
March 1981
SCOTT ENVIRONMENTAL SERVICES
A Division Of
SCOTT ENVIRONMENTAL TECHNOLOGY, INC.
Plumsteadville, Pennsylvania 18949
Scott Environmental Technology Inc.
-------
TABLE OF CONTENTS
Page
1.0 INTRODUCTION . . . . 1-1
2.0 SUMMARY OF RESULTS 2-1
3.0 RESULTS AND DISCUSSION 3-1
3.1 TAR STORAGE TANK 3-1
3.2 LIGHT OIL STORAGE TANK 3-3
3.3 TAR INTERCEPTING SUMP 3-5
4.0 PROCESS DESCRIPTIONS 4-1
5.0 FIELD SAMPLING AND ANALYSIS METHODOLOGY 5-1
5.1 DETERMINATION OF BENZENE FROM STATIONARY SOURCES:
EPA METHOD 110 AND MODIFICATIONS .................... 5-1
5.2 TRACER TESTING 5-4
5.3 SAMPLE HANDLING 5-4
5.4 FIELD ANALYSIS 5-5
6.0 FIELD SAMPLING PROCEDURES 6-1
6.1 TAR STORAGE TANK 6-1
6.2 LIGHT OIL STORAGE TANK 6-1
6'. 3 TAR INTERCEPTING SUMP 6-3
7.0 LABORATORY SAMPLE ANALYSIS 7-1
7.1 SAMPLE PREPARATION 7-1
7.2 PURGE AND TRAP PROCEDURE FOR EXTRACTION OF BENZENE FROM
LIQUID PHASE TO GASEOUS PHASE ... 7-2
7..3 GAS CHROMATOGRAPH 7-4
8.0 QUALITY CONTROL AND QUALITY ASSURANCE 8-1
8.1 FIELD ANALYSIS PROCEDURES 8-1
8.2 PROCEDURES FOR ANALYSIS OF PROCESS LIQUIDS 8-2
Scott Environmental "fechnotogy Inc
-------
SET 1957 02 1180 Page 1-1
1.0 INTRODUCTION
Scott Environmental Services, a division of Scott Environmental
Technology, Inc. conducted a testing program at Wheeling-Pittsburgh Steel
Corporation in Monessen, Pennsylvania to determine benzene emissions from
the coke by-product recovery plant. The work was performed for the United
States Environmental Protection Agency, Emissions Measurement Branch, under
Contract No. 68-02-2813, Work Assignment 48. The Monessen plant was the
third of seven plants visited to collect data for a possible National
Emission Standard.for Hazardous Air Pollutants for benzene.
Sampling was conducted at Wheeling-Pittsburgh Steel on August
11-13, 1980. Integrated air samples and liquid samples for benzene
analysis were collected from the tar storage tank, light oil storage
tank, and the tar intercepting sump.
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 2-1
2.0 SUMMARY OF RESULTS
Benzene Emission Rate
Process Ib/hr kg/hr
Tar Storage Tank 0.50 0.23
Light Oil Storage Tank <1.1 <0.5
Common Tar Intercepting Sump 4.16 1.89
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 3-1
3.0 RESULTS AND DISCUSSION
3.1 TAR STORAGE TANK
Tar is stored at approximately 160°F in the //2 tar storage tank
to drive off the entrained water and facilitate handling. The tank is
vented to the atmosphere, and any benzene in the tar will potentially be
released along with the water.
The average emission rate for the tar storage tank is 0.50 Ib/hr
with a maximum emission rate of 0.85 Ib/hr in Run 3, as shown in Table 3-1.
Testing was conducted on two consecutive days, and the first day's results
are lower than those of the second day. This could be a result of the tank
being fuller on the second day of testing; 165,000 gallons as compared to
162,000 gallons.
Also on the first day the stack temperature and velocity were
fairly constant during each sampling run whereas during Test 3 on the next:
day the temperature and flow rate fluctuated considerably. At the end of
the test the flow dropped to almost zero, and consequently the temperature
dropped to near ambient. This was not caused by any obvious changes such
as the sun going behind a cloud, but tank breathing losses are due to many
parameters like solar insolation, tank liquid volume, liquid temperature
and ambient temperature, and the fluctuations are due to some combination
of these variables.
All stack flow rates were corrected to the average conditions at
which the benzene concentrations were measured in the Tedlar bags; assumed
to be saturated at 68°F and 29.92 inches Hg (2 1/2 % moisture). Example
calculations are shown in Appendix A.
Scott Environmental Technology Inc.
-------
TABLE 3-1
TAR STORAGE DATA
Process Tar Storage Tank #2
Plant Wheeling-Pittsburgh Steel, Monessen, PA
Date
8/12/80
8/12/80
8/13/80
Sample
Period
1530-1600
1710-1740
1015-1045
Stack
Temp.
95
122
109
Barometric
Pressure
(in. Hg)
29.18
29.18
29,27
Stack
Velocity
(ft/min)
60
64
80
SUMMARY
Stack Diameter 8 1/4"
Stack Area 0.37 ft2
Flow Rate
Stack
Conditions
(ACFM)
22
24
30
Flow Rate
Standard
Conditions
(SCFM)
20
19
25
Benzene
Concentration
(ppm)
1043.1
1658.7
2772.2
Avg.
Benzene
Emission
Rate
(Ib/hr)
0.25
0.39
0.85
0.50
w
M
H
VO
0
ro
H1
NJ
CO
O
Run
No.
1
2
3
Standard Conditions: Saturated at 68°F, 29.92 inches Hg
LIQUID SAMPLE DATA
Sample Location
Date
Time
Flushing Liquor on Surface in Tank 8/13/80 1520
Inlet to Tar Tank - From Pump
8/13/80 1455
Temp
168
160
Benzene
Concentration
(ppm by Weight)
1580
1672
1565
1765
2159
1677
Avg.
1606
1867
Pi
OQ
CO
NJ
-------
SET 1957 02 1280 Page 3-3
Liquid temperatures were 71°C at the inlet and 75.5°C in the tank.
The liquid surface samples contained mainly flushing liquor, which forms the
upper phase in the tank over the tar layer. The surface layer samples con-
tained 1600 ppm benzene, and the tar collected from the inlet pump had 1870 ppm
benzene.
3.2 LIGHT OIL STORAGE TANK
The #7 light oil storage tank holds a mixture of the light and
heavy fractions from the rectifier. The liquid contains approximately 70%
benzene by weight and is stored at ambient temperature. The tank is vented
to the atmosphere and is thus a potential benzene emission source. At the
time of sampling the only tank emissions were due to tank breathing losses.
The light oil storage tank had an average emission rate of less
than 1.1 Ib/hr. This tank had a very high concentration of benzene in the
headspace but no outflow was detectable with the anemometer. Emission rates
from the tank are based on the flow rate being less than the lowest detectable
limit of the anemometer, which is 12 feet per minute.
The high benzene concentration in the vapor (~2.5%) is due to the
'high percentage of benzene in the light oil (70%). However, at ambient
temperature the vaporization rate of the light oil was too slow to drive a
measureable flow velocity from the vent.
Scott Environmental Technology Inc.
-------
jit^ lAJJLfc J-
LIGHT OIL STORAGE I
S Process Light Oil Storage Tank #7
i1
S. Plant Wheeling-Pittsburgh Steel, Monessen, PA
f
g- Stack Barometric Stack
. Run Sample Temp. Pressure Velocity
(? No. Date Period (°F) (in. Hg) (ft/min)
8- 1 8/12/80 1532-1602 93 29.18 *
"g- 2 8/12/80 1645-1715 93 29.18 *
3 8/13/80 1022-1052 77 29.27 *
*Not Detectable - less than 12 fpm
Standard Conditions: Saturated at 68°F, 29.92 inches Hg
LIQUID SAMPLE DATA
Sample Location Date
Light Oil Outlet - From Pump 8/13/80
-i
)ATA SUMMARY
Stack Diameter 7 1/2"
Stack Area 0.31 ft2
Flow Rate Flow Rate
Stack Standard Benzene
Conditions Conditions Concentration
(ACFM) (SCFM) (ppm)
<4 <4 29500
<4 <4 22900
<4 <4 25400
Avg.
Benzene
Temp Concentration
Time (°F) (ppm)
1505 77 680,000
750,000
670,000
Avg. 700,000 (70%)
Benzene
Emission
Rate
(Ib/hr)
<1.2
<0.9
<1.1
<1.1
00
(D
CO
-------
SET 1957 02 1280 . Page 3-5
3.3 TAR INTERCEPTING SUMP
The common tar sump receives ammonia liquor, tar from the primary
cooler, tar from the crude tar storage tanks, pump room floor drain waste-
water, exhauster booster and seal pump wastewater, Cottrell precipitator
wastewater, and condensate from the desuper heater. A pump then feeds the
material directly to the decanters. The sump is approximately A' x 8' and
is open to the atmosphere, constituting a potential fugitive benzene
emission source.
The benzene emission rates varied from 2.99 to 4.91 Ib/hr with
an average of 4.16 Ib/hr. The data collected at this source exhibits an
effect not observed at any other source tested using the tracer gas method.
The concentrations of benzene and isobutane vary as much as 95% between
sampling locations on the same run but the mass to mass ratios were in close
agreement. The variable wind at this location undoubtedly accounts for this
effect.
The liquid samples collected at the sump had a temperature of
about 150°F and contained approximately 1700 ppm benzene in the tar fraction
-and /2400 ppm benzene in the top fraction, which was mainly flushing liquor.
Scott Environmental Techndosy Inc
-------
Page 3-6
TABLE 3-3
TAR INTERCEPTING SUMP
Date: 8/12/80
Test #1, Run //I
Test Start - 11:25 a.m.
Sample
LOG.
West 1
.West 2
North 1
North 2
Upwind
Cone, of
Benzene
(ppm)
5.78
1.28
3.95
13.14
0.56
Date: 8/12/80
Test #1, Run //2
Test Start - 2:22 p.m.
Date: 8/13/80
Test #2, Run #1
Test Start - 8:35 a.m.
Cone. of
Isobutane
(ppm)
2.23
0.26
1.56
2.30
0.30
West 1
West 2
North 1
North 2
Upwind
4.56
1.43
9.33
19.72
0.34
1.84
0.50
4.14
8.65
0.10
West 1
West 2
North 1
North 2
Upwind
8.09
4.73
14.20
3.41
2.86
2.92
1.52
3.89
1.06
1.00
Isobutane
Release 'Rate: 0.
0.
Mass to Mass Ib/hr
Ratio $/ic, Benzene
3.48
6.52
3.39
7.67
Isobutane
3.33
3.80
3.03
3.07
,3.03
5.69
2.96
6.69
Avg. 4.59 Avg.
Release Rate: 1.
0.
3.73
4.26
3.40
3.44
Avg. 3.71 Avg.
Average Emission 4.15
Isobutane
3.72
4.18
4.91
4.33
Release Rate: 1.
0.
4.26
4.79
5.62
4.96
872 Ib/hr
396 kg/hr
kg/hr
Benzene
1.38
2.59
1.35
3.04
2.09
121 Ib/hr
508 kg/hr
1.70
1.94
1.55
1.56
1.67
1.89
145 Ib/hr
519 kg/hr
1.94
2.18
2.55
2.25
Avg. 4.91 Avg. 2.23
Scott Environmental Technology Inc.
-------
Page 3-7
Table 3-3
(Continued)
Date: 8/13/80
Test #2, Run #2 '
Test Start ^ 11:25 a.m.
Isobutane Release Rate:
1.122 Ib/hr
0.509 kg/hr
Sample
Loc.
West 1
West 2
North 1
North 2
Upwind
Cone, of
Benzene
(ppm)
8.48
4.66
10.18
17.17
0.42
Cone, of
Isobutane
(ppm)
2.88
1.54
3.70
4.78
.0.10
Mass to Mass
Ratio j>/ic,
3.97
4.07
3.70
4.83
Average Emission 4.78
Ib/hr
Benzene
4.45
4.57
4.15
5.42
4.65 . Avg.
4.78
kg/hr
Benzene
2.02
2.07
1.89
2.46
2.11
2.17
Date: 8/13/80
Test V/3, Run #1
Test Start - 1:23 p.m.
West 1
West 2
North 1
North 2
Upwind
6.15
2.07
6.36
11.24'
0.34
2.85
1.01
3.08
6.16
ND
Isobutane Release Rate: 1.176 Ib/hr
0.533 kg/hr
2.90
2.75
2.06
2.45
3.41
3.23
2.42
2.88
1.55
1.47
1.10
1.31
Avg. 2.99 Avg. 1.36
Date: 8/13/80
Test #3, Run #2
Test Start - 2:07 p.m.
West 1
West 2
North 1
North 2
Upwind
5.30
2.26
9.75
16.11
0.58
2.09
0.85
4.00
6.90
0.14
Isobutane Release Rate: 1.216 Ib/hr
0.552 kg/hr
3.41
3.57
3.28
3.14
4.15
4.43
3.99
3.82
Avg. 4.08
Average Emission 3.54
1.89
1.97
1.81
1.74
Avg. 1.85
1.61
Scott Environmental Technofosy Inc
-------
SET 1957 02 1280 Page 3~8
TABLE 3-4
•LIQUID SAMPLE DATA: COMMON TAR SUMP
Date: 8/13/80
Time: 1345
Sample Temp.: 150°F
Benzene Concentration
Sample Fraction (ppm by Weight)
Heavy Fraction - Sample 1 1740
Sample 2 .2020 Avg. 1720
Sample 3 1400
Light Fraction - Sample 1 4.0
Sample 2 1.03 Avg. 3.78
Sample 3 6.3
NOTE: Triplicate liquid samples were dipped from the sump. Each sample
was separated into heavy and light fractions and each fraction was analyzed
separately.
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 4-1
4.0 PROCESS DESCRIPTION
The Wheeling-Pittsburgh Steel Corporation coke plant at Monessen,
Pennsylvania started construction in 1942. Approximately 90 percent of the
coke plant, including by-product recovery operations, was constructed in
1942 using a Koppers design. The processes used at the Monessen plant for
recovery of coke oven gas are primary cooling, tar decanting, turbine
exhausting, tar electrostatic precipitation (ESP), Koppers semi-direct
ammonia absorption, ammonia still, tar bottom final cooling, light oil
recovery, and clean coke oven gas reuse. A process flow diagram of the
gas and liquid streams is depicted in Figure 4-1.
The gas leaving the ovens is collected in collecting mains where
it is sprayed with flushing liquor for initial cooling. The gas and the
flushing liquor leave the battery area and are transported from the collect-
ing main through a crossover main into the suction main and then into the
by-product recovery area. The gas and liquid initially separate in the by-
product recovery area at a downcomer where the flushing liquor falls out
and is discharged to the tar decanter, while the gas continues to the
primary coolers.
The two tar decanters in parallel separate the liquor into tar and
flushing liquor layers. Additional inputs.to the tar decanters come from
the common tar intercepting sump and the final cooler. The flushing liquor
is pumped to the flushing liquor running tank before returning to the
battery spray system. The excess flushing liquor is pumped to a holding
tank before processing in an ammonia still where caustic is added to the
Scott EnvironmentaT Technology Inc.
-------
FLUSHING LlOUOfl
O
V
E
N
S
**-
PRIMARY
&F
IP
I
< oc
EXHAUSTER
»
TAR
ESP.
r >
AMMONIA
SATURATOR
IKOPPERSI
SEMI-DIRECT
45-52° C
1
FIN
LIGHT
OIL
SCRUBBER
32° C CLEAN CAS
LIGHTS
TO BATTERY
TO UPPER MILL USE
LIGHTS
f
RECTIFIER
STORAGE
j
HEAVIES
-»SELL
OIL/WATER
OIL
INTERCEPTING
SUMP-
WASTE OIL
STORAGE
QUENCH
SUMP
EFFLUENT TO
RIVER OUTFALL
Figure 4-1
-------
SET 1957 02 1280 Page 4-3
liquor. The tar layer is pumped to an 18 cubic meter (4,000 gallon) running
tar tank before pumping to a pump tank. Excess tar from the running tar
tank is pumped to three of the four tar storage tanks. The tar from the
pump tank is circulated to the primary cooler and the final cooler. The
tar flow to both units varies proportionally with the naphthalene concentration.
The gas stream from the downcomer enters the direct primary coolers
at approximately 82°C. There are three parallel primary coolers at the
plant, but only two were on-line during the visit. The circulating liquor
is cooled by indirect Niagara coolers that circulate river water which is
atmospherically cooled. Excess tar and liquor are discharged to the common
tar intercepting sump.
The gas exits the primary coolers at approximately 30°C and enters
the turbine exhausters. There are two turbine exhausters, but only one was
in operation at the time. The gas stream in the exhauster changes from
vacuum to positive pressure which supplies the motive power for the system.
Some tars are separated in the exhauster and drained to the common tar
intercepting sump.
The gas enters the tar ESP where additional tar is separated from
the gas and drained to the common tar intercepting sump. There are three
parallel ESP's and all were in operation during the plant visit. The plant
can operate on only one tar ESP. However, normal operation is two and the
preference is three.
The gas stream from the tar ESP's is combined with the ammonia
vapor from the ammonia still and enters the ammonia saturator. There are
two Koppers semi-direct ammonia saturators used one at a time. The gas
Scott Environmental Techndosy Inc
-------
SET 1957 02 1280 Page 4-4
stream is contacted with sulfuric acid which produces ammonium sulfate
crystals as the final product. The gas leaves the ammonia recovery oper-
ation at approximately 45-52°C.
The gas then enters the final cooler. There are two final
coolers also used one at a time. The final coolers are tar bottom coolers
that circulate water and tar. The naphthalene-lean water is cooled in an
atmospheric cooling tower and the naphthalene-rich tar is pumped to the
tar decanter for separation. Tar is continuously recirculated to the final
cooler. The rate of circulation is determined by withdrawal of samples
through a manifold system on the side of the cooler.
the gas leaves the final cooler at approximately 30°C and enters
the light oil scrubbers. There are two light oil scrubbers in series with
countercurrent flow of the wash oil and the gas stream. The benzolized
wash oil leaves the bottom of the light oil scrubber and passes through a
vapor/oil heat exchanger before entering the final heater. After the final
heater, the benzolized wash oil enters the wash oil still where the light
oil is steam-stripped from the wash oil. The light oil vapors leave the
top of the still and pass through the vapor/oil heat exchanger before
entering the rectifier. The debenzolized wash oil is pumped to the wash
oil circulating tank before recirculating to the light oil scrubbers.
Oil/water blowdown from the light oil scrubbers, the wash oil still, and
the rectifier is drained to the oil intercepting sump. After the rectifier,
the light and heavy fractions are combined in final storage.
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 4-5
The clean gas exits the light oil scrubbers at approximately 32°C
and enters the gas holder before boosting to the battery underfire and upper
mill use. The clean coke oven gas has a heating value of 580-527kJ (550-
530 Btu) and is not mixed with natural gas to increase this value.
4.1 PROCESS OPERATING PARAMETERS
During the tests, the coke output of the plant was 524 tons per
day. Battery 1A, with 37 ovens (6 ovens not operating), and Battery 2,
with 19 ovens, were operating. The coking time was 24 hours for Battery
1A and 22.5 hours for Battery 2. The amount of coke oven gas produced was
8 to 8.5 million cubic feet per day. The coal blend was 35 percent high
volatile coal (1.42 to 1.48 percent sulfur), 48 percent of a different
type high volatile coal (0.68 to 0.74 percent sulfur), and 17 percent low
volatile coal. The coal make-up was 17 percent low volatile coal and 83
percent high volatile coal for Battery 1A and 12 percent low volatile coal
and 88 percent high volatile coal for Battery 2.
Table 4-1 contains the storage tank process data recorded during
the emission tests. Light oil and crude tar production rates during the
tests were approximately 2,500 gallons per day and 6,000 gallons per day,
respectively. Approximately 13,000 gallons of light oil were shipped from
storage on both test days. Crude tar is shipped once a month. The light
oil and crude tar tank capacities are 125,000 gallons and 250,000 gallons,
respectively.
The common tar intercepting sump contains ammonia liquor, tar
from the primary cooler, tar from the crude tar storage tanks, pump room
floor drain wastewater, exhauster booster and seal pump wastewater,
Scott Environmental TechnokDgylnc
-------
SET 1957 02 1280 Page 4-6
Cottrell precipitator wastewater, and condensate from the desuper heater.
The liquid level in the sump was approximately 2 feet below the level recorded
in the presurvey. Plant personnel confirmed that the low level of liquid
in the sump was caused by decreased plant production. The liquid in the
sump during the emission tests was approximately 0.83 feet deep. The liquid
temperature in the sump during the emission tests was approximately 19°C.
Scott Environmental Technobsy Inc
-------
S.ET 1957 Q2 1280
Page 4-7
TABLE 4-1 STORAGE TANK PROCESS DATA
Unit
Number 7 Light Oil
Storage Tank
Number 2 Crude Tar
Storage Tank
Test
Run
1
2
3
1
2
3
Tank Interior
Test Date Temperature (°C)
8/12/80
8/12/80
8/13/80
8/12/80
8/12/80
8/13/80
30
30
30
65
65
65
Tank Liquid
Volume (gallons)
31,000
31,000
26,000
162,000
162,000
165,000
Scott Environmental Techndogy Inc
-------
Page 5-1
SET 1957-02-1280
5.0 FIELD SAMPLING AND ANALYSIS METHODOLOGY
5.1 DETERMINATION OF BENZENE FROM STATIONARY SOURCES:
EPA METHOD 110 AND MODIFICATIONS
EPA Method 110 consists of drawing a time-integrated stack .gas
sample through a probe into a Tedlar* sample bag, which is enclosed in a
leak-free drum, by use. of a pump hooked to the drum outlet which slowly
evacuates the drum, causing the bag to fill. A copy of the method is
included in Appendix D.
The method was modified by Scott because as it stands the
method doesn't account for moisture in the sample stream, and is only
designed to measure benzene concentration, not mass emission rate. The
following modifications were made to all tests done using Method 110:
1. To obtain mass emission rates, velocity and temperature
readings were taken at the top of the stack at 5 minute intervals during
the 30-minute sampling runs. This information was used to calculate flow-
rate, which was used in conjunction with the benzene concentration to
yield the mass emission rate. Velocity readings were made using a vane
anemometer with direct electronic readout.
2. A personnel sampling pump was substituted for the pump,
needle valve, and flowmeter of the method. The personnel pumps have
built-in flowmeters- and rate adjustment screws and have the further
advantage of being intrinsically safe, as required in many areas of
the coke plant.
* Mention of trade names or specific products does not constitute endorsement
by the U.S. Environmental Protection Agency.
Scott Environmental Technokxjy inc
-------
Page 5-2
SET 1957-02-1280
3. Swagelok fittings were used in place of quick-connects.
4. Rather than discarding Teflon sample lines after each set
of samples, they were washed with propylene carbonate and/or acetone and
flushed with nitrogen before reuse.
5. An orifice and magnehelic gauge were inserted in the sampling
line before the Tedlar bag to indicate that air flow was reaching the
bag.
6. A water knockout trap was inserted between the probe and
magnehelic gauge to collect any condensate in the sample line.
7. The following cleanup procedures were followed:
If any condensate was collected in the trap or sample line, it
was measured and saved for analysis. The probe, line and trap were then
washed with propylene carbonate, which was also saved for analysis. Any
benzene found in these washes and water catches was added to the total found
in the sample bag to determine mass emission rates.
Bag volumes were measured whenever water was collected in the
trap by emptying the bag through a dry gas meter after the sample was
analyzed. The volume of water collected in the trap was then converted
to an equivalent air volume and was added to the volume in the bag to
determine the percent moisture in the sample stream.
After the probe, line and trap washes were completed, the lines
were washed with acetone to remove the propylene carbonate film and flushed
with nitrogen to dry.
Figure 5-1 shows the modified Method 110 setup.
Scott Environmental Technology Inc.
-------
SET 1957-02-1280
Page 5-3
MODIFIED METHOD 110
SAMPLING TRAIN
-------
Page 5-4
SET 1957 02 1280
5.2 TRACER TESTING
The tracer gas method is a practical procedure for quantifying
mass emissions of volatile organics from sources which are essentially
open to the atmosphere without disturbing flow, dispersion patterns or
the source operation. This method utilizes the release of a tracer gas
directly over the source of interest; the tracer gas will then follow the
same dispersion patterns as the emissions from the source. The mass of
tracer released over the sampling period is known and the mass to mass
ratio of the benzene to the tracer gas in the sample is determined by
gas chromatography. The emission rate of benzene can be calculated with
this information.
This method is based on the principle that the chosen tracer gas
will model the dispersion of benzene from the source. The tracer gas
chosen for this proj ect was isobutane because it was not present in the
sources to be tested and it could readily be separated from other source
trace components by the same column used for benzene. In addition, iso-
butane is.a non-toxic gas that can readily be dispensed from a pressurized
cylinder at a uniform measured rate.
When this method was used triplicate tests were performed. Each
test consisted of two 1/2 hour runs. For each run clean and backgrounded ten-
liter Tedlar bags were used. Integrated samples were collected using
Emission Measurements, Inc. Air Quality Sampler II systems. The AQS II
samplers are self-contained units capable of collecting one or more inte-
grated samples at a preset rate. For tracer tests the sampling rate used
was ten liters per hour.
5.3 SAMPLE HANDLING
After being collected the gas samples were immediately transported
to the gas chromatograph and analyzed. The elapsed time between sample
collection and analysis never exceeded one hour. To verify that there was
no sample degradation in samples of this type some of the samples were
retained for 24 hours and reanalyzed. The loss of benzene and isobutane
observed was typically less than 5%.
Scott Environmental Technology Inc.
-------
Page 5-5
SET 1957 02 1280
5.4 FIELD ANALYSIS
All gas samples collected were analyzed using a Shimadzu GC Mini 1
gas chromatograph equipped with dual flame inoization detectors, dual
electrometers, heated sample loop and a backflush system. Figure 5-2 shows
a schematic of the backflush apparatus. The backflush.system is composed
of ten port sequence reversal valve and two columns, a scrubber column for
retaining high molecular weight compounds and an analytical column. When
the system is in the inject mode the scrubber column and the analytical
column are connected in series allowing sample components to move from the
precolumn to the analytical column. In the backflush mode the columns are
disconnected from each other and become two separate systems each with its
own carrier gas source. This arrangement allows the separation and
measurement of low molecular weight compounds while the scrubber column
is being backflushed of heavier sample components. Backflush times for
different mixtures of sample components must be predetermined to insure that
the compound(s) of interest are transferred to the analytical column before
backflushing is started.
Samples for chromatographic analysis were drawn into a 20 cc glass
syringe then introduced to the sample loop inlet. The samples once in the
sample loop were allowed to come to.atmospheric pressure by waiting 15
seconds prior to the injection. When only benzene was of interest the
following chromatographic conditions were maintained:
Column Temperature (isothermal) - 100°C
Injector and Detector Temperature - 200°C
5 ml Sample Loop, Temperature - 50°C
Carrier Gas Flow Rate - 32 cc/min
Hydrogen Flow Rate - 40 cc/min.
Air Flow Rate - 240 cc/min.
Analysis Time - 5 min.
Detector - Flame lonization
Scott Environmental, Technotogy Inc
-------
O
l/i
I
CARRIER GAS A
PREP, COLUMN
SAMPLE INJECTION
B
CARRIER GAS B
ANALYTICAL COLUMN
DETECTOR
INJECT
A, D, E OPEN
B, C CLOSED
BACKFLUSH
A, E CLOSED
B, C, D OPEN
GC COLUMN CONFIGURATION WITH BACKFLUSH
vO
tn
o
K3
I
M :
a> ,
o i
39
m
Ul
I
-------
Page 5-7
SET 1957 02.1280
The columns used for field analysis were:
A - Scrubber Column
10% FFAP on Supelcoport 80/100
1/8" x 1 m Stainless Steel
B - Analytical column
20% SP-2200, 0.1% Carbowax 1500
100/120 Supelcoport
1/8" x 10' Stainless Steel
When samples from tracer tests were analyzed the chromatographic
conditions were changed to provide adequate separation of the isobutane
tracer from the other light components of the sample. The temperature
program used for this analysis was:
1) Start at room temperature with external cooling fan
on and oven door open.
2) Inject @ 0.0 min.
3) Turn external cooling fan off @ 1.0 min.
4) Backflush @ 1.8 min.
5) Isobutane elutes @ 2.3 min.
6) Close oven door @ 3.0 min. with oven temperature :
set at 100°C.
7) Benzene elutes @ 7.0 min.
8) After the elution of benzene, open the oven door and
turn on the cooling fan. The next injection can be
made after 2 minutes of cooling.
9) When the tracer gas is used analysis time will be
approximately 10 minutes.
The columns and flow rates were the same as for- isothermal.
Scoct Environmental Technolosy Inc
-------
SET 1957 02 1280 Page 6-1
6.0 FIELD SAMPLING PROCEDURES
6.1 TAR STORAGE TANK
Three half-hour EPA Method 110 tests were conducted on the tar
storage tank on August 12th and 13th, 1980.
Before beginning, the naphthalene that had accumulated around
the test vent was knocked away to insure accurate velocity readings, and
the manway, which was found open, was covered. The runs all were very
straightforward and no problems were encountered. The tests were run
concurrently with the light oil storage tank runs, as the tanks were
adjacent to one another and connected by a walkway across the top (See
Figure 6-1).
Liquid samples were collected from the inlet to the tank via a
pump at ground level, and from the surface of the liquid in the tank by
dipping with a bucket on a line.
6.2 LIGHT OIL STORAGE TANK
The vent on the light oil tank was constructed by the sampling
team from two sections of steel stovepipe, fastened to a flange at deck
level on the top of the tank. This was necessary in order to obtain
accurate velocity readings from tank. The manway, which was found open,
was covered during the test runs.
Three half-hour EPA Method 110 tests were run on August llth and
12th, 1980. Stack temperature was ambient at all times, and no flow rate
could be measured with the vane anemometer.
Liquid samples were collected from an inlet to the storage tank
via a pump at ground level. The liquid temperature was 25 C (ambient).
Scott Environmental Technology Inc.
-------
Page 6-2
LIGHT OIL STORAGE TANK
TAR STORAGE TANK
Inc.
FIGURE 6-1 LIGHT OIL STORAGE TANK AND TAR STORAGE TANK
-------
SET 1957 02 1280 Page 6-3
6.3 TAR INTERCEPTING SUMP
Benzene emissions from the tar intercepting sump at Wheeling-
Pittsburgh Steel in Monessen, Pennsylvania were measured on 8/12 - 8/13/80
using the tracer method.
The sump was 8' long, 4' wide and 8 1/2' below grade. The liquid
was approximately 8" deep and the liquid temperature was 150°F (66°C).
There was one major inlet located in the NW corner of the sump approximately
3* above the liquid level. Make-up liquid falling from this height, created
turbulence over the entire sump but especially in the corner in which it
was located. A pump located at the sump's east end was constantly pumping
the effluent to the tar decanters, which resulted in a steady flow of
material through the sump.
This source was located very close to several large physical
obstacles. On the NW corner of the sump was a large building
(25* in height) which houses process equipment. On the W and SW sides of
the source there was a maze of tanks, pipes and process equipment beginning
5' from the edge of the sump and extending approximately 50' back. This
area was sufficiently compact to block any wind from that direction. On
the SE corner of the sump 10' from the edge was a pile of pipe approximately
5' in height and 20' long. The NE and N sides of the sump were clear of
obstructions. In spite of the degree of congestion in the immediate area
there was ample space for sampler placement close to the source on any side.
Wind direction varied widely coming generally from the S. This
variability of direction did not seem to alter the direction of emission
significantly. Observation of the steam plume rise revealed that the
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 6-4
emissions were confined to the 180° quadrant from W to N over 90% of the
time but did vary within that quadrant. The sampling strategy was to
bracket the W and N sides of the sump; this was accomplished by placing
4 samplers, 2 on each side, 4' back from the sump edge (See Figure 6-2).
The dispersion bar spanned the sump along its 81 length at the liquid
level. With this arrangement of samplers and a variable wind, the emissions
measured on each side of the sump were different but the average of the
total emissions was similar for different sampling runs.
Scott Environmental Technology Inc.
-------
Page 6-5
0
WEST S/DE SAMPLERS
SAMPLER
• SOl/H
1
6'
TRACER
o
MLET
i
i
i
i
PLATE-
COVER S~
•
BAR
_
••
\£ SUMP PUMP
RAIL
NORTH SIDE
SAMPLERS
N
Inc.
iC.O^y
FIGURE 6-2 . COMMON TAR INTERCEPTING SUMP
-------
'SET 1957 02 1280 Page 7-1
7.0 LABORATORY SAMPLE ANALYSIS
Two types of liquid samples were collected: process liquids, and
sample line and water trap catches and washes. All liquid samples were
stored in amber glass bottles and returned to Scott's Plumsteadville laboratory
for analysis.
7.1 SAMPLE PREPARATION •
Depending upon the complexity of the sample, one of the following
sample preparation procedures was followed prior to the "purge and trap"
procedure and analysis. .•;'•";'•'
Samples Containing Immiscible Liquid Phases
Using a clinical centrifuge (International Equipment Company,
Massachusetts) immiscible liquid phases were separated and each phase was
analyzed separately for benzene.
Samples Containing Solid and Immiscible Liquid Phases
Samples containing solids of higher density than the liquid phase
were separated by centrifuge or by simple decantation of the liquid. The
different phases in the liquid fraction were then further separated by
centrifuging. Solid and liquid phases were analyzed separately.
Samples Containing Finely Crystalline Solid Suspension
In analyzing these samples the stoppered sample jars were shaken
for at least half an hour for homogenizing the solution. The uniform
distribution of suspended fine crystalline solid particles was tested by
determining the percentage of dry solid in several aliquots of the homoge-
nized mixture. A weighed amount of the mixture was analyzed for benzene.
Scott Environmental Technclosy Inc
-------
SET 1957 02 1280 Page 7-2
Sampling System Washings
All washings were clear solutions having only one liquid phase.
The total weight, of the liquid phase was determined using a balance correct
to ±0.1 g. The total weight of each washing wss more than 25 grains, so an
error of 0.1 g in weighing the mass will contribute an error of only 0.4%
to the final analytical data. A weighed aliquot of the washing was analyzed
for benzene by following the "purge and trap" and analysis procedures out-
lined in the following sections, and using this analysis data the weight
of benzene present in the total mass of washing was calculated.
7.2 PURGE AND TRAP PROCEDURE FOR EXTRACTION OF BENZENE FROM LIQUID PHASE
TO GASEOUS PHASE
An accurately weighed quantity of the sample to be analyzed was
diluted with 20-25 ml of propylene carbonate in a specially designed glass
purging apparatus which was kept immersed in a thermostatted water bath
maintained at 78°C. Benzene free nitrogen gas was bubbled through the
propylene carbonate solution in the purging apparatus at the rate of
0.2 - 0.3 liters/minute, and collected in leak free Tedlar bags. Under
these experimental conditions, 1 1/2 - 2 hours were sufficient to purge
off all the benzene from the. liquid phase to the gaseous phase. The total
volume of nitrogen gas used to purge the sample was accurately measured
by a calibrated dry gas meter. A diagram of the purge and trap set-up is
shown in Figure 7-1.
Propylene carbonate was found to be an ideal diluting solvent
for the extraction of benzene from all types of liquid samples containing
viscous tar, pitch, light and heavy oil and insoluble particulates. It
was chosen for its high boiling point, low density, and good solvating
capacity.
Scott Environmental Technology Inc.
-------
FIGURE 7-1 PURGE AND TRAP METHOD EQUIPMENT SET-UP
TJ
. 09
(D
-vl
u>
-------
SET 1957 02 1280 Page 7-4
7.3 GAS CHROMATOGRAPH
••• ' . • _;., v. : •'••'•• •'
A Perkin-Elmer 900 gas chromatograph was used for the analysis
of the purge bags. A 10 ft. by 1/8 inch stainless steel column packed with
20% SP^2100/0.1% Carbowax 1500 on 80/120 mesh Supelcoport was used for the
analysis. This column gave complete resolution of the benzene peak from
other components present in the purge bags. The 'peak height* method was
utilized to calculate the concentration of benzene in the purge bags
analyzed. The Perkin-Elmer 900 used for analysis was not equipped with
a backflushing unit. Gas chromatograph conditions were as follows:
GC column temperature: 70°C isothermal
Detector temperature: 190°C
5 ml loop at a temperature of 120°C
Carrier gas flow rate: 30 cc/min He
Hydrogen flow rate: 45 cc/min
Oxygen flow rate: 400 cc/min
Detector: Flame lonization Detector (FID)
In addition to benzene, the purge bags contained other volatile
hydrocarbons present in the liquid samples such as toluene and naphthalene.
Because this chromatograph was not equipped with a backflush, it was
necessary to elute all heavy organics from the column by heating the column
to 150°C after every two injections for one hour with the carrier gas on.
After cooling the column to 70°C the absence of any organic in the column
which might overlap the benzene peak in the next analysis was checked. When
the column was found to be satisfactorily clean, the next analysis was
continued under the conditions previously described.
Scott Environmental Technology Inc.
-------
SET 1957 02 1280 Page 8-1
8.0 QUALITY CONTROL AND QUALITY ASSURANCE
The following sections will address quality control and quality
assurance procedures for th«: field analysis of benzene in air samples and
the laboratory analysis of process liquids and BaP samples.
8.1 FIELD ANALYSIS PROCEDURES
All samples were analyzed in duplicate and as a rule peak heights
were reproduced to within 5%. For some very high concentration samples
(percent range) it was necessary to make dilutions for analysis. When this
was done a fresh dilution was prepared for each injection and peak heights
were reproduced to within 10%. To verify that the system was retaining no
benzene, frequent injections of.the standard and nitrogen were made. In all
cases the result was satisfactory.
The Tedlar bags that were reused for sampling were flushed three
times with nitrogen and allowed to sit overnight after being filled to
approximately three quarters of their capacity. They were analyzed for
benzene content the following day. The background concentrations of the
bags were recorded and varied from 0 to 10 ppra benzene. Care was taken to
use sample bags whose background concentration was very low compared to the
expected concentration of the source.
The accuracy and linearity of the gas chromatographic techniques
used in this program were tested through the use of EPA Audit Samples. Two
standards, a 122.5 ppm and 6.11 ppm benzene were used to analyze the audit
cylinders.
Scott Environmental Technology Inc.
-------
SET 1957 01 1280 Page 3-2
8.2 PROCEDURES FOR ANALYSIS OF PROCESS LIQUIDS
Scott's benzene standards, checked against EPA Audit Standards,
were used as reference standards throughout this program. The accuracy and
linearity of the gas chromatographic technique for benzene analysis was
tested through the use of EPA Audit Standards which were available to Scott.
Gas chromatographic analysis of the samples and standard were performed
under identical conditions to assure the accuracy of the analytical data
generated.
Each batch of propylene carbonate which was used as the diluting
solvent in the purge and trap technique was analyzed for benzene content by
subjecting 25 ml of propylene carbonate to the purge and trap procedure
followed by gas chromatographic analysis of the trapped gas under identical
conditions as described in Section 5.2. All batches of analytical grade
propylene carbonate were found to be free from benzene.
Every day before the analysis of samples the purging apparatus and
trapping bags were tested for absence of benzene. Whenever the whole system
was found to be free from benzene to the lowest detectable limit of the
instrument, the samples were analyzed using the purging apparatus and the
trapping gas sampling bags.
Generally an accurately weighed mass of each sample was subjected
to purge and trap procedure only once and the trapped* gas sample was repeat-
edly analyzed by GC until the analytical data of consecutive GC analyses varied
by ±0.5% or less.
Scott Environmental- Technology hx:
-------
SET 1957 02 1280 , Page .8rf3 ;.,
For randomly selected samples, the whole analytical procedure was
repeated with a different weighed mass of the source sample to check the
validity and accuracy of the analytical methodology. The analytical-data
for different runs were found, not to vary by more than 5%.
By purging the sample with nitrogen under the experimental con-
ditions as utilized by Scott, the recovery of benzene from the sample was
quantitative and this has been verified by analyzing a standard benzene
solution in propylene carbonate containing tar and pitch.
Scott Environmental Technology Inc.
------- |