c/EPA
           United States
           Environmental Protection
           Agency
          Office of Air Quality
          Planning and Standards
          Research Triangle Park NC 27711
EMB Report 81-8YC-13
September 1981
           Air
Benzene
Coke Oven By-Product Plants
Fugitive Process Emissions
           Emission Test Report
           Vapor-Liquid Analyses

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                HEADSFACE

          BENZENE CONCENTRATION
        OVER LIQUID SAMPLES FROM

         COKE BY-PRODUCT PLANTS
         EPA Contract 68-02-3544
            Work Assignment 3
            ESED Number 74/4j
             September 1981
           Prepared For:
            Mr. Daniel Bivins
  U. S. Environmental Protection Agency
         OAQPS, EMB, ESED, MD-13
Research Triangle Park, NC   27711

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                            TABLE OF CONTENTS
                                                                      Page
1.0  INTRODUCTION ..........................   1
2.0  RESULTS
3.0  DISCUSSION OF RESULTS  .  .
4.0  ANALYTICAL PROCEDURES
     APPENDIX A -  FIELD DATA SHEETS
     APPENDIX B -  LIQUID  SAMPLE ANALYSIS
     APPENDIX C -  LABORATORY HEADSPACE DATA

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                                  -1-
                           1.0  INTRODUCTION
          Scott Environmental Services conducted a benzene sampling program
at seven coke by-product plants during the summer of 1980 for the U.S.
Environmental Protection Agency.  Fugitive process emissions from sources
were determined by measuring the benzene concentration in the stack gas and
the gas flow rate and temperature.   Process liquid samples were also collected
from each source.
          A test program was conducted to determine if any correlation existed
between the benzene emission, rate from a process and the benzene concentration
in the headspace over a liquid sample from that process.  If a correlation
existed it would allow emission rate estimates  based on a simple laboratory
procedure rather than on field sampling procedures.
          Laboratory tests were performed on liquid samples from eight con-
fined sources.  The samples were heated in enclosed vessels and headspace
samples were extracted and analyzed by gas chromatography.  Two separate
sets of experimental conditions were used.  Initially the samples were
heated to process temperature in vented flasks.  Due to the great variability
in the results a new procedure was  devised wherein the samples were all
heated to 212°F while maintaining a constant pressure as thermal expansion
of the headspace gas occurred.  No  gas was vented.
          The following sections present the results and analytical procedures
of the vapor headspace. sampling program.

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                                   -2-
                              2.0  RESULTS
          Table  2-1 presents the results of the headspace sampling at 212°F
 (unvented)  and the calculated ratios of headspace/liquid concentrations,
 headspace/stack  gas concentrations, and stack gas/liquid concentrations.
 The  results  of the headspace sampling at process temperatures  (vented) are
.shown  in  Table 2-2, with the ratios of headspace at 212°F/headspace at
 process temperature and headspace at process temperature/stack concentration.
 The  two tar  decanters are not included in Table 2-2 because the headspace
 benzene concentrations were not measured at process temperature.
          All the process  samples used in  this program were dipped from  the
 liquid surface  through  a hatchway, with the single  exception of  the  tar
 dehydrator  at Burns Harbor, where the sample was collected from  a pump at
 the tank  outlet..

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                        TABLE 2-1   HEADSPACE BENZENE CONCENTRATIONS AT 212°F
Source/Plant
Wash Oil Decanter (F)

Tar Decanter (BH)
Tar Decanter (B)

Tar Dehydrator-W (F)

Tar Dehydrator-E (F)

Tar Dehydrator (BH)

Tar Storage (P)

Tar Storage (M)


Sample
Composition
Oil
Aqueous
Aqueous
Heavy Tar
Heavy Tar
Whole Tar
Aqueous
Aqueous

Process
Temp.
t- (°F)
205
120
178
207
219
162
145
168
(S)
Stack
Benzene
Cone.
(ppm-V)
817
2473
1380
1757
2080
9133
630
1825
(L)
Liquid
Benzene
Cone.
(ppm-Wt )
44
92
5
621
276
1987
33
N.A.
(H)
Headspace
Benzene
Coric.
At 212°F
(ppm-V)
1404
2388
336
4261
1390
12385
2550
1402


H/L
Ratio
32
26
64
6.9
5.5
6.3
70.0
—


H/S
Ratio
1.7
1.0
0.3
2.4
0.7
1.4
3.7
0.8


S/L
Ratio
18.6
26.9
230
2.9
7.4
4.7
19.1
—
(F)  = Fairless
(BH) = Burns Harbor
(B)  = Bethlehem
(P)  = Pueblo
(M)  = Honessen

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          TABLE 2-2   HEADSPACE BENZENE CONCENTRATIONS AT PROCESS TEMPERATURES
 Source/Plant
 Wash Oil Decanter (F)
 Tar Dehydrator-W (F)
 Tar Dehydrator-E (F)
 Tar Dehydrator (BH)
 Tar Storage.(P)
 Tar Storage (M)
Process
Temp.
t (°F)
  205
  207
  219
  162
  160
  169
Ht
Headspace*
Benzene
Cone.
at t (ppm-V)
Avg.
179
1273
521
2346
75
252
Max.
189
1273
521
5296
193
622
H
Headspace**
Benzene
Cone.
at 212°F
(ppm-V)
1404
4261
1557
12385
2309
1402
H/Ht
Ratio
7.8
3.3
3.0
5.3
30.8
5.6
Ht/Stack
Ratio
0.22
0.72
0.25
0.26
0.12
0.14
 *Vented headspace procedure
**Confined headspace procedure

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                                 -5-
                      3.0  DISCUSSION OF RESULTS
          The lack of any close correlation between the headspace benzene
concentration and the source concentration measured in the field tests of
multi-phase processes is due to the many other variables which affect the.
benzene emitted by these sources.   These variables include:
          1.  Type of Process - continuous, steady state;  continuous,
              variable-, batch.
          2.  Nature of Material - tar,  oil,  aqueous,  combination of
              tar and aqueous.
          3.  Dynamic residence time of  continuous processes.
          4.  Degree of agitation of process  material.
          5.  Concentration of water and light organics in tars and oils.
          6.  Thickness of aqueous layer in aqueous organic systems.
          7.  Process headspace volume vs. process surface area.
          8.  Temporal variations in temperature,  liquid level,
              liquid composition,  throughput, etc.
          9.  Ambient temperature and pressure.
          The liquid samples chosen for  this  test  program were those, collected
from confined sources, i.e. covered and  vented to  the  atmosphere, because
the conditions affecting open sources would introduce  many more variables
into the. data analysis.
          Each of the above factors has  an impact  on the concentration and
rate of benzene emissions.  A detailed discussion  of the role  of each variable
is beyond the scope of this task,  but a  brief- discussion of a  tar decanter
will demonstrate the complex nature of these  systems.   Tar decanters are
used to separate mixtures of tar and ammonia  liquor from primary coolers and
battery collector mains into liquor, tar and  sludge.  The tar  decanter tested
at Bethlehem Steel, Bethlehem, Pennsylvania yielded benzene concentrations
of 720 to 1980 ppm in the vent during three test runs.  The flushing liquor
sampled from the surface (180°F) which'contained 5 ppm (wt)  benzene gave a
headspace benzene concentration of 386 ppm at 212°F.  The incoming material
from the primary cooler contained approximately 20% tar and 80% flushing
liquor.  The flushing liquor contained 16 ppm (wt) benzene and the tar 1800 ppm
(wt).  Headspace gas from this material  contained  41,000 ppm benzene which

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                                 -6-
is 100 times the concentration in the corresponding surface liquor (no tar)
analysis.  This demonstrates the transfer of benzene from the tar to the
flushing liquor and then to the headspace in the laboratory analysis.   In
the actual process, the tar decanter contains a tar layer beneath the
surface flushing liquor yet the measured benzene concentration was 20 to 50
times less than in the laboratory test of the tar/liquor sample.   In fact,
the measured process concentrations average only 2 to 5 times the laboratory
result from the liquor alone.   The most likely factor limiting the actual
process emission is the thickness (depth) of the liquor layer. The thickness
c-f the liquor layer was not measured but can be assumed to be at  least 1 to
2 feet,  In the laboratory test, the liquor layer in the flask was less than
one inch thick, thus facilitating transfer of the benzene in the  tar to the
headspace.  If the tar decanter were operated as a static (batch) process,
it would be expected that the  benzene concentration would approach the
41,000 ppm value obtained in the lab test.   However, during normal operations
as a continuous flow system with.-a short dynamic residence time,  the benzene
concentration remained less than 2,000 ppm.
          The above data demonstrate that the benzene emissions from a com-
plex multi-phase system cannot be estimated from simple laboratory tests.
The relatively fev; confined, multi-phase systems included in the  field test
program and the limited information available on process variables preclude
any further search for a means of estimating emissions from such  sources.
          Further work would have tc be based on more extensive field data
and on complex phase transfer  and boundary layer theory and experiment.

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                                 -7-
                      4.0  .ANALYTICAL PROCEDURES
          Two separate sets of experimental conditions were used to measure
headspace benzene from samples collected from confined sources.   Initially
headspace benzene concentrations were measured with the liquid sample at
process temperature in a vented flask.  Experimental procedures  were subse-
quently revised such that headspace benzene was measured with the liquid
sample at 212°F without any venting.  212°F was chosen because it provided
a convenient way to maintain a stable sample bath temperature.
          For the first series of determinations at process temperature,
25 cc of the liquid sample was placed in a graduated glass vessel which
was fitted with a ground glass joint.  The vessel top had a single port
which was covered by a small rubber septum.  A 20 gauge syringe  needle was
inserted in the septum for the purpose of relieving pressure and simulating
the process vent.  The samples were heated by immersing the vessel in a
beaker of water which was maintained at the process temperature.  Samples
were allowed to equilibrate in the water bath for approximately  15 minutes
prior to extraction of headspace gas samples for injection into  the chromatograph.
          From the triplicate liquid samples collected from each process, an
aliquot of a single sample was aniyzed for the tarry materials and a composite
of all three samples was analyzed for the less viscous liquids.   Replicated
determinations were not done during this phase of the analysis.   Chromatographic
data for consecutive injections of the same sample show a significant degree
of variability.
          This lack of replicability was attributed to problems  in maintaining
a constant bath temperature and also to the open vent in the top of the vessel,
which was releasing benzene from the vessel and consequently changing the
concentration of benzene in the headspace.   The experimental procedure was
revised such that, all samples were heated to 212°F in a boiling  water bath,
and a 20 cc or 50 cc syringe was used in place of the open syringe needle, to
relieve pressure without releasing benzene as the sample was heated.  This
created a more stable equilibrium in the sample vessel prior to  extraction of
a headspace sample for analysis.  Chromatographic data for this  second pro-
cedure had a higher degree of precision than did the previous analysis.

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                                  -8-
          For the chromatographic analysis  of most samples it was necessary
to dilute samples before injection into  the chromatograph.  Dilutions were
typically by a factor of 10 or 20.
          All gas samples were analyzed  using a Shimadzu GC Mini 1 gas
chromatograph equipped with dual flame ionization detectors,.dual elec-
trometers, heated sample loop and a backflush system.
          The samples were drawn into a  glass syringe and 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 injection.  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 Ionization
          The columns used for laboratory analysis were:
                A - Scrubber Column
                   • 10% FFAP on Supelcoport 80/100
                    1/8" x 1 m Stainless Steel
                B - Analytical Column
                    20% SP-2100,  0.1% Carbowax 1500
                    100/120 Supelcoport
                    1/8" x 10' Stainless Steel

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   APPENDIX A
FIELD DATA SHEETS
 LIQUID SAMPLES

-------
                                        Page B-10

                           PROJECT 1906 BENZENE/BaP PRESURVEY
Plant
                                SAMPLE   DATA
                                    Process
                                             Tgr J
Date   ~7
Sample No.
                                           Time Sampled
Sample Type: (Liquid/    Air
Sample Temperature
                                                         ©
                                                           T"  O
Ambiient 'Temperature
Description of Sampling Location:
                                                                        0
Sample No.
Sample Type:  .Liquid    Air

              ^l*~ __ —**^


Sample Temperature     Q pi   C-
Ambient Temperature
Description of Sampling Location:
                                          Time Sampled
                                                                                    /
                                                                             /^U/LxUL^e.

                                                                 1)
                                                            /vA-i  c^wxjtf-M, &~f~
Sample No.
                                          Time Sampled
Sample Type:   Liquid    Air
Sample Temperature
Ambient Temperature
Description of Sampling Location:

-------
Plant
                                        Page B-13   '

                           PROJECT 1906 BENZEN'E/BaP PRESURVEY



                                SAMPLE   DATA
Process
                                                                        Date
Sample N<
         .   TD
Sample Type:  (Liquid)    Air
Sample Temperature
       Time Sampled




               •&h<
                                                               ,->
Description of Sampling Location:
Sample No.
                                          Time Sampled
Sample Type:
Sample Temperature
                        Air
Ambient Temperature
Description of Sampling Location:
                                                                        £ od If
Sample No.
Sample Type:  Liquid    Air
Sample Temperature
Ambient Temperature
                                          Time Sampled
Description.of Sampling Location:

-------
                           PROJECT   1957  07 0181





                                SAMPLE   DATA





Plant  f?(/£/V'£ /'fa rbo/Z	  Process  "Trj £ d pf r{ /i ,-f-ff T       Date
           ~T~/I ?>  7%, x-   ^    ^-(  7  ^                  ^ ' ")   Time Sampled   ^V i .-< J





Sample Type:^  Liquid!     Air





Sample Temperature 	)  (^ 0    /
Ambient Temperature
                          /•
                         Co
Description of Sampling Location:
                 f    -f->    -/^
                 AL-Cg^U/r (*;gn I G^'1' i
Sample No.   1 gU  
-------
                                                                       Page B-6
                             PROJECT 1906 BENZENE/BaP PRESURVEY
                                  SAMPLE    DATA
  Plant
                                     Process
"•>/"~  Date
  Sample  No.
                                            Time Sampled
  Sample Type:   Liquid     Air
  Sample  Temperature
  Ambient  Temperature
  Description of Sampling Location:
                                            .  0   .,/  ',.'
                                           • _;. .   v-'J /  ' & (_, -
  ."'..•.  / ) '
  Sample No.
                                           Time Sampled   -c--',.
0
  Sample  Type:   Liquid/    Air
  Sample  Temperature
  Ambient  Temperature
  Description of Sampling Location:
  Sample  No.
                                           Time Sampled
  Sample  Type: (Liquid\   Air





  Sample  Temperature 	
                              \
'•''Ambient  Temperature
Description of Sampling Location:
                                            ,

                                          '^|. /.'^.i

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                           PROJECT 1906 3E.'!ZENE/3uP PRESLJRVEY






                                 SAMPLE   DATA
                                                                        Page B-14
Plant
              f(? g I   "fa i\J.i>,4^   Process  ~TOj\. JUljg A\Q .'Grf .     Date   ?///
'  Sample No.
                      '4-
                                            Time Sampled
                                                              6  '
Sample Type: \TIquid      Air


                       m
Sample Temperature
Ambient Temperature
Description of Sampling Location:


                                                                          (

Sample
                                  f   o      I




                 i\v,'j- .  ^  I C/A"5) V' ___ ^fime Sampled     (p .' "SL

Sample Type: ^Liquid    Air
Sample Temperature    (f\
Ambient Temperature
Description of Sampling Location
                              ion:  JL^fltJ
                                                                     ! 60--5
   Sample No.
                   KUu-
                     \r
                           .•
                                           Time Sampled
                                                            (0
Sample Type:  iLiquid     Air
Sample Temperature
                         ^ I <5?
                        ^ j  1
Ambient Temperature
Description of .Sampling  Location:

-------
Plant
                           PROJECT 1906 BENZENE/BaP PRESURVEY
                                SAMPLE   DATA
              Process
                                               Page B-9
                                                                        Date
Sample No.
Q
                        e C^t(V   ^ | 1,3 Time Sampled    M
Sample Type: VLjLquid )    Air






Sample Temperature   $  Oj    \
Ambient 'Temperature    Q   ]   |
Description of Sampling Location:
                          P P
Sample No.
                    Time Sampled
Sample Type:  Liquid    Air
Sample Temperature
Ambient Temperature
Description of Sampling Location:
Sample No.
Sample Type:  Liquid    Air
Sample Temperature
Ambient Temperature
                    Time Sampled
Description of Sampling Location:

-------
 Plant
                                                             Page  B-8

                           PROJECT  1906  BENZEME/BaP PRESURVEY



                                 SAMPLE   DATA
                                    Process
 Sample No.    I £r   j V\
                                           Time Sampled
 Sample Type:  (Liquid/    Air



 Sample Temperature      f f    ( „
Ambient Temperature
Description of Sampling Location:
             t


Sample No.   /*--« U •
                                           Time  Sampled
Sample Type:  \Liquid /   Air




Sample Temperature




Ambient Temperature
                          	
 Description of Sampling Location:
                        rff
.Sample No.
 Sample Type: [Liquid )   Air
 Sample Temperature
Ambient Temperature
 Description of Sampling Location:
Tine Sampled
                                                                               \3  /r?
                                                                               J    i

-------
      APPENDIX B
LIQUID SAMPLE ANALYSIS

-------
Source/Plant

Tar Decanter (B)
Tar Decanter (BH)
Tar Dehydrator (BH)
Tar Storage (P)
       Liquid Sample Analysis

Sample Location    Date

Liquor on Surface  7/8/80
                   7/8/80

Liquor on Surface  9/23/80
Tar from Outlet    9/23/80
  Pump


Liquor on Surface  10/7/80
Wash Oil Decanter (F)   Oil on Surface     9/10/80    1640
Tar Dehydrator-W (F)     Tar-on Surface     9/11/80    1820
Tar Dehydrator-E (F)    Tar on Surface     9/11/80    1825
Time
1525
1600
1525
1420
1700
1640
1820
1825
Sample
Temp.(F°)
176
180
120
162
145
205
207
219
Benzene*
Cone . (ppm-wt)
5.6
4.2
181.6
58.1
35.5
1956
1834
2171
16.8
75.4
6.2
42.2
40.3
50.3
629
599
634
282
286
261
*Note:  The three concentrations shown for most sources were obtained from three
        separate liquid samples collected^consecutively.

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       APPENDIX C
LABORATORY HEADSPACE DATA

-------
                                     ClIROMATOCRAPHIC ANALYSIS  LOG
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-------
                                    CHROMATOGRAPHIC ANALYSIS LOG
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Sample Identification
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-------
                                    CHROMATOCRAPHIC ANALYSIS LOG
Project No,
Date
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Sample Identification
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-------
                                        CHROMATOGRAPHIC ANALYSIS LOG
    Project Ko,_
                              Date
                                "Analyst
Time
Sample Identification
Height/Area
Concentration
   Factor
Concentration
                                                                                              CornniGnt
                                                                                 fO
                                                                                                 1 !

-------