MARCH 1977 AMC7010.T0108F-FCR
REGIONAL AIR POLLUTION STUDY (RAPS)
100% COMPLETION REPORT
FOR
TASK ORDER 108-F
HYDROCARBON EMISSION INVENTORY
Prepared for
Environmental Protection Agency
Office of Air & Water Management
Office Of Air Quality Planning Standards
Research Triangle Park, N.C. 27711
by
F. E. Littman
R. W. Griscom
G. Seeger
Rockwell International
Atomics International Division
Air Monitoring Center
11640 Administration Dr.
Creve Coeur, Mo. 63141
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AMC7010.T0108F-FCR
TABLE OF CONTENTS
PAGE
1.0 INTRODUCTION
2.0 HYDROCARBON INVENTORY DATA
3.0 SENSITIVITY ANALYSIS
4.0 METHANE, NON-METHANE SEPARATION METHODOLOGY
5.0 SOURCE TESTING FOR HYDROCARBON CLASSIFICATION
APPENDIX I: SOURCE CLASSIFICATION CODE (SCC) LISTING
VERSUS PERCENTAGE CLASSIFICATION OF
METHANE AND NON-METHANE HYDROCARBONS
APPENDIX II: CHROMATOGRAPHIC METHOD FOR SEPARATION OF
METHANE AND NON-METHANE HYDROCARBONS
APPENDIX III: HYDROCARBON SOURCE TESTS
1
2
4
6
11
13
16
43
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AMC7010.T0108F-FCR
TABLES
PAGE
TABLE 1 HYDROCARBON SOURCE LOCATIONS 3
TABLE 2 METHANE EMISSIONS HYDROCARBON SOURCES 7
TABLE 3 NATIONAL EMISSIONS DATA SYSTEM (NEDS) SOURCE
CLASSIFICATION CODE (SCC) REPORT 9
TABLE 4 EMISSION FACTORS 10
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AMC7010.T0108F-FCR
1.0 INTRODUCTION
As part of the RAPS Point Source Inventory a new Hydrocarbon Emission
Inventory has been completed for the St. Louis Air Quality Control Region
(AQCR-70). The existing point source inventory primarily dealt with those
hydrocarbon emissions produced by fuel combustion. This has been expanded
to include all hydrocarbon emission sources which emit more than one ton per
year of total hydrocarbons.
The inventory is chiefly concerned with "point" sources, or those emissions
which are released through a stack or vent as in the case of a petroleum storage
tank. It does not include area sources such as gasoline stations, dry cleaning
and mobile sources. Point sources in the St. Louis AQCR emit approximately
47,000 tons per year total hydrocarbons, or 17.8 percent of the hydrocarbon
emissions in the AQCR.
Data for the hydrocarbon inventory are primarily annual data. The exception
to this is for the hydrocarbon emissions from fuel combustion. The inventory
for fuel combustion sources is the most detailed since, due to the nature of the
operation, hourly records are available in most cases. Data for evaporative
emissions, which account for approximately 40% of the point source hydrocarbon
emissions, are only accurate for accounting periods and are thus presented as
annual data.
The National Emission Data System (NEDS) Inventory indicates a total of
78,000 tons of hydrocarbon emitted per year in the AQCR. The principal reason
for the large discrepancy between the two inventories is that the NEDS inventory
includes a large number of fixed roof gasoline and crude oil storage tanks
which have since been replaced with floating roof storage tanks.
As part of this Task a methodology has been developed for separating the
total hydrocarbon emissions into methane and non-methane components by Source
Classification Code (SCC). This is described in Section 2.
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AMC7010.T0108F-FCR
2.0 HYDROCARBON INVENTORY DATA
The hydrocarbon point source inventory represents emissions from 64
companies in AQCR-70 with emissions in excess of one ton per year. The
NEDS inventory indicated a total of 78,474 tons per year from point sources.
The NEDS data show quite a large number of fixed roof storage tanks with
gasoline or crude oil. This situation no longer exists; with only a few ex-
ceptions all highly volatile liquids are stored in floating roof storage tanks.
The hydrocarbon emissions in the AQCR are now appoximately 47,000 tons per
year from point sources. Thirty-seven of the locations emit in excess of
100 tons per year, ten in excess of 10 tons per year, and seventeen are in
excess of one ton per year.
The data for the hydrocarbon inventory was obtained by contacting all
of the companies with hydrocarbon emissions in the AQCR. Locations accurate
to 10 meters were obtained from visiting plant sites and pinpointing the
location of sources on Geological Survey maps. The data included petroleum
storage capacities and throughputs, coatings and solvent production and usage,
and calculated emissions. In addition, hydrocarbon emissions are obtained
from combustion information which is continuously being received as part of
the point source inventory. All of the data were recorded on RAPS coding forms,
keypunched, and entered into the RAPS Point Source Data Base. Table 1 is a
list of the companies which furnished data for the hydrocarbon inventory.
Emission patterns for hydrocarbon sources vary widely due to the variety
of types of hydrocarbon sources. Data which are being received continuously
as part of the RAPS Point Source Inventory are generally on an hourly basis
Hydrocarbon data from sources which produce or use coatings and solvents are
accompanied with hourly use patterns based on working hours during a year.
Evaporative emissions from petroleum storage are assumed to be generated on a
continuous basis and are therefore spread equally throughout the year. With
the exception of hydrocarbons from hourly combustion data, the hydrocarbon
emission data are collected as annual data.
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AMC7Q10.T0108F-FCR
TABLE 1
HYDROCARBON SOURCE LOCATIONS
Amoco Oil
Shell Oil
Clark Oil
Granite City Steel
General Motors
Ford Motors
Chrysler Motors
Mobil Oil Terminal
Lianco Container
American Can
Crown Cork & Seal
Phillips Oil Terminal
Morris Paint
Monsanto
Kellwood
Continental Can
Union Electric
Illinois Power
A.O. Smith
Great Lakes Carbon
Harvard Interiors
McDonnell Douglas
Williams Pipeline Terminal
Triangle Terminals
Texaco Terminal
Shell Oil Terminal
J. D. Street Terminal
Independent Petrochemical
Missouri Terminal
Amcar
Empire Stove
Mallinckrodt
Municipal Incinerators
Alpha Cement
Missouri Portland Cement
Vitro Products
Ramsey
Martin Oil Terminal
Apex Oil Terminal
Laclede Steel
Moss American
Washington University
Autocrat
Scott Air Force Base
Precoat Metals
Sunoco Terminal
Hartog Terminal
Granite City Army Inst.
Menard Penitentiary
Mascoutah Power Plant
Edwin Cooper
01 in
American Steel
Nestle
Reilly Tar and Chem.
As discussed in Secion 4.0, the hydrocarbon emissions will be available
as a separate printout of methane and non-methane hydrocarbons in addition to
the normal printout in which total hydrocarbons are included in the Point
Source Emission Listing.
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AMC7010.T0108F-FCR
3.0 SENSITIVITY ANALYSIS
To evaluate the accuracy of the hydrocarbon inventory a sensitivity analysis
has been applied to the data. This is similar to the analysis performed for S00
M)
with the point source inventory under another Task Orderv . To determine the
allowable error of a subclass of pollutant the following equation is used:
a. =9 3- where: CTk = allowable error
k
0 = permissible maximum error
Q = Total emissions
Qk = Emissions subclass
The allowable error is the maximum permissible error of any part of the
inventory, given a maximum permissible error for the whole system. This
approach keeps the inventory at an equivalent level of accuracy and points out
areas where accuracy has to be improved. To evaluate this inventory a fairly
stringent set of conditions were applied: a confidence level of 95 percent and
an acceptance interval of 10 percent. This leads to a maximum permissible
error for the system, 0, of 2.25%.
The analysis indicated that under these constraints, the hydrocarbon
inventory has an allowable error of 49% for the major source subclass of 100
tons per year, 153% for a 10 ton source, and 485% for a 1 ton source.
Since hydrocarbon sources are principally evaporative sources, they are
not monitored hourly. Data are accumulated over longer time periods, generally
for accounting purposes. Thus, long term data are quite accurate; however,
the time pattern of emissions is not well known. A closer examination indicates
that emissions from most evaporative sources, are fairly uniformly distributed.
The major exception to this are loading docks. As a result, the evaporative
hydrocarbon emissions from loading docks may not meet the sensitivity require-
ments on an hourly basis. These sources account for 3700 tons per year, or
approximately 7.9% of the total hydrocarbon emissions in the AQCR.
(1) Littman, F. E., "Regional Air Pollution Study Point Source Methodology
and Inventory", EPA - 450/3-74-054, October 1974.
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AMC7010.T0108F-FCR
The data were entered into the inventory together with an operating
pattern which describes the operation of the source as well as can be done
within the constraints of the data handling system.
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AMC7010.T0108F-FCR
4.0 METHANE, NON-METHANE SEPARATION METHODOLOGY
Hydrocarbons participate in the formation of photochemical oxidants. The
extent of participation is determined by their respective reactivities. Methane
is universally accepted as being non-reactive. More importantly, methane is a
normal constituent of the atmosphere as a result of natural decomposition pro-
cesses. Therefore, a gross classification has been performed and hydro-
carbon inventory has been separated into methane and non-methane hydrocarbons.
Trijonis and Arledge v ' have recently reported on a hydrocarbon classifica-
tion scheme for the Los Angeles area based on 2, 5 and 6 reactivity categories.
The only difference between the 5 and 6 category schemes is that methane is
considered separately in the latter. Although their classifications are strictly
valid only for Los Angeles, their breakdown (for methane only) was applied to
sources in St. Louis under this Task and compared with a limited number of source
tests. Table 2 indicates the molar percent methane for the applicable types of
sources in St. Louis. The molar percentages were determined by assuming that the
non-methane hydrocarbons have an average composition of C,-, as reported by
Trijonis and Arledge. Catalytic Crackers were not included in the referenced
report but have been added based upon a source test in St. Louis. In addition,
the number for coke oven emissions is from an as yet unpublished report on a
test of a local coking plant sponsored by the EPA .
The breakdown in Table 2 for combustion sources was verified by six source
tests of combustion sources in St. Louis.
A few of the results obtained from source testing are quite different from
those reported by Trijonis and Arledge, such as the result for SCC code 1-02-002-09
in Table 2. For all sources in St. Louis which were tested, the test results
will be used to determine new (or "special") emission factors to be applied to
these sources. These special emission factors are only valid for the source
tested. For other sources with the same SCC number, such as 1-02-002-09, the
percentages from the Trijonis and Arledge report will be used.
(2) Trijonis, J. C., and K. H. Arledge, "Utility of Reactivity Criteria in
Organic Emissions Control Strategies for Los Angeles", EPA Contract
No. 68-02-1735, December 1975.
(3) Conversation with Kirk Foster, USEPA, 30 September 1976.
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AMC7010.T0108F-FCR
TABLE 2
METHANE EMISSIONS HYDROCARBON SOURCES
Methane, % of THC
Source SCC Ref. (1) RAPS Source Test
Petroleum Refining - Storage 4-03-002-01 2 nil
- Catalytic Cracker 3-06-002-01 20
Fuel Combusion - general 1-XX-XXX-XX 78
- utility boiler, oil 1-01-005-01 74
- industrial boiler, oil 1-02-004-01 71
- industrial boiler, coal 1-02-002-09 43
Surface Coating* - Heat Curing 4-02-XXX-XX 2 30
- Air Dry 4-02-XXX-XX 0 10
Degreasing 4-01-002-XX 0
Industrial Manufacturing 3-01-XXX-XX 0
Coking Plants 3-03-003-XX 0
*N_ote: SCC numbers do not relate a difference between heat curing and air
drying.
The values in Table 2 have been incorporated into a scheme based on the
Source Classification Code (SCC). The SCC is an identification system developed
for NEDS, upon which the point source hierarchy is structured. The SCC system
is being used for the RAPS point source data handling system. All data is stored
and retrieved by use of the SCC. Any plant or process which causes air pollu-
tion can be represented by one or several SCC numbers. Table 3 shows a typical
sample of SCC numbers. The SCC numbers consist of four groupings. For example;
in SCC 4-03-001-02:
Group I - a single digit (4) - designates "Point Source, Evaporative"
Group II - two digits (03) - designates "Petroleum Storage"
Group III - three digits (001) - designates "Fixed Roof"
Group IV - two digits (02) - designates "Breathing - Crude"
In addition the base unit upon which the emission factors are based is given;
in this case, "1000 gallons storage capacity".
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AMC7010.T0108F-FCR
The starting point of the inventory are the emission factors which relate
emissions to the operation of the sources. These factors are based upon the
best available information, generally gathered from source tests. Data are
gathered which are based upon consumption, production, or storage and emission
factors are applied to generate emissions. Table 4 shows a typical example of
emission factors and the associated SCC numbers.
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AMC7010.T0108F-FCR
TABLE 3
NATIONAL EMISSIONS DATA SYSTEM (NEDS)
SOURCE CLASSIFICATION CODE (SCC) REPORT
scc 10
•••*•*
1 11 III IV
SCC CATEGORY NAMES
I
II
3 90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
3 99
4 01
4 01
01
01
01
02
02
02
02
02
03
OJ
001
002
002
002
002
002
004
004
004
004
004
004
004
004
OOb
OOb
005
005
005
OOb
005
OOb
006
OOb
OOb
OOb
006
OOb
OOb
OOb
007
COM
OOv
999
999
999
999
001
001
002
002
999
001
003
001
005
006
999
001
001
99 INDUSTRIAL PROCESIINPROCESS FUEL
01 INDUSTRIAL PHOCESIINPROCESS FUEL
06 INDUSTRIAL PROCEblINPHOCESS FuEL
07 INDUSTRIAL F>HUCE S I I NPHUCE SS FUEL
OH INDUSTRIAL PROCESIINPROCESS FUEL
99 INDUSTRIAL FRoctsiINPROCESS FOIL
01 INDUSTRIAL PRUCtSIINPROCESS FUEL
02 INDUSTRIAL PHOCESI INPHOCESS FutL
03 INDUSTRIAL PROCESIINPROCESE FUtL
04 INDUSTRIAL PRUCESIINPHOCESS FutL
05 INDUSTRIAL PHOCLSIiNPHOLtSS FUEL
06 INDUSTRIAL PHOCESIINPHUCESS FUEL
o? INDUSTRIAL ppoctsiINPROCESS FUEL
99 INDUSTRIAL PROCESI INPRO^ESS FUE.L
01 INDUSTRIAL F'Roctsi NPHocrsS FUEL
02 INDUSTRIAL PROCEsI NPROCESS FuEL
03 INDUSTRIAL PHOCE->I N°HOCtsS FUEL
0» INDUSTRIAL PROCESI NPHOCESS FUEL
Ob INDUSTRIAL PHOCflSI NUHUtfSS fUEL
06 INDUSTRIAL PHOCESI NPHC'i'LSS FUEL
07 INDUSTRIAL PHOCESIINPROCESS FuEL
99 INDUSTRIAL PROCESIINPROCESS FUEL
0) INDUSTRIAL f-HuLEsI lNP"OCtSb FUtL
02 INDUSTRIAL PROCESIiNPROCtSS FUEL
03 INDUSTRIAL PR-OCEbl iNPROCtsS FUEL
04 INDUSTRIAL PROCESIINPROCESS FUEL
05 INDUSTRIAL PROCEsIINPHOCCiS FUEL
06 INDUSTRIAL HRUCtSIINPROCESS FutL
07 INDUSTRIAL PROCEjI INPHOCtSS FUtL
99 INDUSTRIAL PROCESIINPHOCESS FoEL
99 INDUSTRIAL PHOCFsIJNPHOCFSS FUEL
99 INDUSTRIAL PHUCESIINPROCESS FUEL
99 INDUSTRIAL fROCEsIINPHOCESS FUEL
97 INDUSTRIAL PROCESIINPROCESS FUEL
98 INDUSTRIAL PHOCESIINPROCESS FuEL
99 INDUSTRIAL PHOCESI INPHOCESS FUEL
99 INDUSTRIAL PHOCtSIOTHLH/NOT CLASIFD
III
(ANTHRACITE COAL
(BITUMINOUS COAL
(BITUMINOUS COAL
IHITUMJNOO'S COAL
(BITUMINOUS COAL
(BITUMINOUS COAL
(RESIDUAL OIL
IPESIDUAL OIL
(RESIDUAL
[RESIDUAL
IKESIDUAL
IRESI'iUAL
IHESIDUAL
IHt SIDUAL
(DISTILLATE
(DISTILLATE
IDISTU LATE
IOISTILLATE
IOISTILLATE
(DISTILLATE
IDISTILLATE OIL
(DISTILLATE OIL
INATURAL GAS
(NATURAL GAS
(NATURAL GAS
INATUHAL GAS
(NATURAL GAS
(NATURAL GAS
(NATURAL GAS
INATUHAL GAS
IPROCESS GAS
IV
UNITS
OIL
OIL
OIL
OIL
OIL
OIL
OIL
OIL
OIL
OIL
OIL
OIL
(OTHER/NOT CLASIFOITONS BURNED
(CEMENT KILN ITONS 6URNEO
(BRICK KILN/DRY ITONS BURNED
IGY^SUM KILN/ETC I TOMS &VHNEO
ICOAL DRYERS iTONb BUHNEO
IOIHEH/MOT CLAS1FOITONS BURNED
IAsPHALT DRYER
ICtxtNT KILN
ILlMt KILN
(KAOLIN KILN
(METAL MELTING
(BRICK KILN/DRY
(GYPSUM KILN/ETC
I 1000 GALLONS BURNED
I 1000 GALLONS BURNED
11000 GALLONS 6UHNF.O
I 1000 GALLONS BURNED
I 1000 GALLONS 6UPNEO
I 1000 GALLONS BURNED
11000 GALLONS BURNED
IOTHIK/NOT CLASIFDI1000 GALLONS BURNED
I 1000
I 1000
I 1000
I 1000
I 1 000
I 1000
I 1000
1 1000
01 POINT SC tVAP
02 POINT SC EVAP
01 POINT SC tVAP
99 POINT SL EVftp
99 POINT SC tVAP
01 POINT SC LYiP
01 POINT SC EVAP
01 POINT sc EV«P
01 POINT SC EV.IP
01 PuINT SC EVAP
99 POINT sc EVAP
01 PuINT SC EVAP
02 POINT SC tV.P
(CLEANING SOLVENT
(CLEANING SOLVENT
(CLEANING SOLVENT
(CLEANING SOLVENT
ICLtANING SOLVtNT
f SURFACE COA TING
(SURFACE COATING
(SURFACE COATING
ISUR^ACc CCiTlNG
(SURFACE COATING
(SURFACE COATING
(PETROLEUM STG
(PETROLEUM SIG
(ASPHALT DRYER
ICEHENT KILN
(LIME KILN
(KAOLIN KILN
(MtTAL HELTING
IBRICK hILN/ORY
IGYPSUM KILN/ETC
(OTHER/NOT CLASIFD
(ASPHALT OHYEH
ICEMENT KILN
ILIME KILN
IKAOLIN KILN
IMETAL MELTING
IB^ICK KILN/DRYS
IGYPSUM KILN ETC
IOTHEP/NOT CLASIFDIMILHON CUBIC f£ET
IOTHER/NOT CLASIFOIMILLION CUBIC FtET BURNED
(COKE (OTHtH/NOT CLASlFDlTONs
I»OOD IOTMER/NOT CLASlFDlTONs SUHNED
(OTHtR/NOT CLASIFOISPECIFY IN REMARK I MILL I ON CUBIC FEET BURNED
(OTHER/NOT CLASIFDISPECIFY IN RE^AHKIIOOO GALLONS BUHNED
IOTMER/NOT CLASIFUISPECIFY IN REMAHKlTONS 6URNED
ISPECIFY IN REMARK! ITONS
IPRYCLfANlNG IPERCHLORETHYLEN6
IURYCLFANING ISTODDARD
IUEGREASING ISTODDAtD
IDEGBE'ASING lOTHtH/NOT
GALLONS t URNED
GALLONS BURNED
GALLONS BUH'ltO
GALLONS BUWNtD
GALLONS HUHNED
GALLONS BURNED
GALLONS BURNED
GALLONS BURNED
(MILLION CUBIC FEET
(MILLION CUBIC FEET
(MILLION CUBIC FEET
(MILLION CUBIC FEET
(MILLION CUBIC
(MILLION CU8IC
(MILLION CUBIC
FEET
FEET
FEET
BURNED
BURNED
BURNED
fcURNtD
BURNED
BUHNLD
BURNED
BURNED
PROCESSED
ITONs CLOTHES CLEANED
ITONs CLOTHES CLEANED
ITONS SOLVENT USED
CLASIFOI TONS SOLVtNf USED
IOTHEP/NOT CLASIFDISPECIFY IN HEMARKITONS SOLVENT USED
IGENEUAL ITONS COATING
(GENERAL ITONS COATING
IGENESAL ITONS COATING
IGENERAL (TONS COATING
IGtNERAL ITONS COATING
lOTHtR/NOT CLASIFDI SPECIFY IN RE"ARKITONS COATING
IflXEU HOOF IBREAThlNG-PROUUCTI 1000
IFJXEij ROOF IBREATH1NG CRUDE 11000
JPAINT
(VARNISH/SHELLAC
ILAQUEH
It NAMEL
IPRIM-.R
GALLONS STORAGE CAPACITY
GALLONS STORAGE CAPACITY
-9-
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TABLE 4
EMISSION FACTORS
AMC7010.T0108F-FCR
POIN1 Sf CVAP -SURFACE COATING (CONTINUED)
POUNDS EMITTED PER UNIT
PART SDK NOX HC
CO
4-02-003-01 GENERAL
LACUfH
4-02-004-01 GENERAL
ENAMEL
4-02-005-01 GENERAL
PRIMER
4-02-006-01 GENERAL
COAIINu OVEN
4-02-008-01 GENERAL
SOLVENT
4-02-009-01 GENERAL
OTHER/N01 CLASIFO
4-OP-999-9') SPECIFY IN REMARK
UNITS
TONS COMING
PC1 INT SO EVAP
FIXED KOUF
4-03-001-01
4-03-001-02
4-03-OU1-0 3
4-03-C01-04
4-O-001-05
4-03-001-06
4-03-001-07
4-03-001-03
4-C3-001-0-J
4-C3-001-IO
4-03-001-U
4-03-001-12
4-03-001-13
4-03-001-14
4-03-001-15
4-03-001-16
4-03-001-50
4-03-001-51
4-03-CC1-52
4-03-001-53
4-03-001-54
4-03-001-55
4-0:1-001-5*
4-03-OOl-i7
4-03-OCI-58
4-03-001-59
4-C3-001-60
4-03-uOl-Dl
FLUAHnl, «00f
4-03-002-01
4-03-O02-U2
4-03-002-03
4-03-002-04
4-03-002-05
4-OJ-C02-06
4-OJ-002-OI
4-03-002-08
4-03-002-09
4-03-002-10
4-03-002-11
4-03-002-12
4-C3-002-13
4-CJ-002-14
4-03-002-15
4-03-002-16
VAR-V4PC8 SPACE
4-03-003-02
4-03-003-03
4-03-003-04
4-03-003-05
4-03-003-06
4-03-003-07
4-0>-003-08
4-03-003-09
4-03-003-10
4-03-003-11
4-03-003-12
4-03-003-13
4-03-003-14
-PETROL PKOO STG
BREATH-GASOLINF
OftF.ATM-C«UDE
WORKING-GASOL INE
liORr.ING-CKUOE
DRFATH-JE1 FUfL
UREATH-F. F.HUSENE
BPEATH-OIST FUEL
Bn(Aln-el:N^ENf
BREATH-CVCLOMEX
8KFATH-CTCLOPLNT
llKEAIH-HtPTANL
SRfAIH-HFXANE
flSEATH-ISOOCTANE
UREATH-ISUPEMANE
BR6A1H-PFNTAHE
BRCATH-THLLIENE
WORKING- JL I FUEL
1«RK ING-KEROStNE
WORKING-OIST FUEL
WORKI NG-fJFNZENE
WORMNG-CrrLUHEX
W'JKKINIi-CYf LCPENT
KORKING-HCCTANE
WOKK ING-HtX ANt
WOKM NG-I SOOCTANE
WORMNG-ISUPFNT
WORKINo-PFNT ANE
MORM NO-TOLUENE
SIAND ST&-GASOLN
KORKING-PROOUCT
STAND STli-CRUOE
WORK !N(r-CKUDE
STAND SIG-JETFUEL
STAND STG-«E«OSNf
ST&NO STG-01ST FL
STAND STG-6ENZENE
STAND STG-CYCLMEX
STAND STG-CYCLPEN
STAND STG-HEPTANE
STAND STu-HEXANE
STAND SIG-ISDOCTN
STAND STo-ISOPENT
STAND STG-PENTANE
STAND STG-TOLUENt
WORKING-GASOLISE
HOUK No-JtT FUEL
WORK NG-KF10SENE
WORK NG-OIST FUEL
WORK NG-BENZENE
hURK NG-CYCLOHEX
WORK NG-CYCLOPENT
WORK NG-HEPTANE
WORK NG-HEXANE
WORK No-ISOOCUNE
WORKING— ISOPENT
WORKING-PENTANE
WORKING-IOLUENe
0.
0.
J.
0.
0.
0.
0.
0.
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0.
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0.
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SO. )
54.8
9.UO
7. JO
2i.2
13.1
13.1
16.3
20.8
58.4
11.3
32.1
13.9
142.
94.9
5.84
2.40
1.0'J
1.00
2.00
2.30
6.40
1.20
3.60
1.50
15.7
10.6
12.0
0.
1O.6
0.
4.38
1.90
1.90
2.70
3.01
8.76
1.64
4.75
2.0 1
20.8
13.9
O.88
10.2
2.30
1.00
1.00
2. JO
2.60
7.20
1.40
4.00
1.70
17.8
12.0
0.73
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
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0.
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0.
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0.
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0.
0.
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0.
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0.
0.
0.
0.
TONS
TONS
TONS
TONS
TONS
IONS
1000
1000
10'JO
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noc
10')0
in.jn
1000
100J
1000
1000
ino
1«00
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1?00
l^OO
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1001
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1 1)0
1000
1 1/00
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noo
1330
1000
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1000
1000
10 JO
ICOO
1 'J fi 0
100G
1 ICO
11CG
1000
loco
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1000
1000
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1 000
1'JOO
1000
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1000
1000
1000
C CIA T I NG
COATING
COA-1NG
COATING
c ot T i nr.
COATING
GALl CMS
GflLl HNS
oM LI'NS
GALLONS
GAIL OH S
GALLONS
r,AI I TJS
GALLCNS
G ALL PUS
GALl PN*
GALl ^NS
GAI LONS
GAI.LLNS
GALLONS
GALL ON*
GAI 1 'INS
GALIO'IS
GAI LONS
GAI 1 i>NS
GALL ONS
".ALLIINS
GALLONS
GALLONS
GAI IONS
GALLONS
GALLONS
GALLONS
GALLCNS
GALL'INS
GALLOMS
GALLONS
GALLnNS
GALLTNS
GAI L')NS
GALLCNS
G A L I PN S
GALLONS
GALL CNS
Gtl L JNb
GALLONS
GALLONS
GALLONS
GALLONS
GALLONS
G«l LONS
GAL 1 ONS
GALI f'NS
GALLONS
GALll.NS
GALLONS
GALLONS
GALLCNS
GALLONS
GALLONS
STORACF C''piCIr
<:TC9AGr. C ADAC! I
THPI'Ii.HP' tT
THkOUGHP'IT
STJrJ AG F ' M'AC 1 T
STL'XAOF CAP!' U
STOC AGF CAPAC I T
ST'T ! AGF CAPAC IT
STuRAi.E CAI'ACIT
STO-JAGE CAPACn
'.TIiKAGF CAPACIT
ST'lFAGF CAP'.CIT
« TOR AGF CAPAi" ! T
THH'j.lGHPMT
THK'IIJGMIMIT
TH^rUGH UT
THB'IUC.H I'T
THPOUGH '|T
THRf'JGM UT
TIIB'TIG" UT
THQUJGH Af IT
STOR«GF C^^ACIT
STORAGE CJPACIT
STCflAGF CADACIT
STl'RAGC CftPAT | T
< IPRAGE CAPAC IT
bT'JPAGF CAP^r;T
THPC*fGHPIIT
THROUGH^ JT
T H« I"*J GHP JT
THt'CUGHPijT
THW n J(,H^' 1 T
THROUGHPUT
THROUGHPUT
THROUGHPUT
THROUGHPUT
THR OUGHPUT
THROUGHPUT
THR OUGHPUT
THR OUGHPUT
f
Y
y
Y
Y
1
Y
Y
Y
Y
Y
Y
Y
V
Y
Y
Y
Y
V
Y
Y
Y
OTHER/NOT CLASIFO
4-03-999-99 SPEClFr IN REMARK
1000 GAL STORED
-10-
-------
AMC7010.T0108F-FCR
5.0 SOURCE TESTING FOR HYDROCARBON CLASSIFICATION
To verify the use of published information and to examine sources where
information is not readily available it was necessary to perform source testing.
A method was developed which would easily measure methane and non-methane hydro-
carbons over a wide range of concentrations. The method is discussed in
greater detail in Appendix II.
The procedure is applicable for testing hydrocarbon sources which range
from a few parts per million to several thousand parts per million. Since only
methane and total hydrocarbons are being determined the results are expressed
as parts per million carbon atoms. The developed method is linear with respect
to carbon number, thus providing a good means of comparison for sources of
differing composition.
The method was used for analyzing samples taken at a petroleum refinery,
a can manufacturer, and a paint line and oven at an auto assembly plant. As
expected, the methane from these sources was very low to negligible with the
exception of the can plant. From the can plant half of the hydrocarbons
measured were methane. This result is unexpected; the source of methane is
probably unburned natural gas in the ovens sampled. The results of these tests
are discussed in further detail in Appendix III.
Prior to developing the method for methane and non-methane analysis some
preliminary investigations were made to find a method for further separating
(4\
reactive and non-reactive hydrocarbons. Groth and Zaccardix ' reported on a
subtractive analyzer system which separated hydrocarbons into two categories
- reactive and non-reactive, where the non-reactive hydrocarbons were princi-
pally paraffins. Klosterman and Sigsby^ ' developed a subtractive method for
separating automotive emissions into paraffins, olefins and acetylenes, and
(4) Groth, Richard H. and Vincent A. Zaccardi, "Development of a High-
Temperature Subtractive Analyzer for Hydrocarbons", J.A.P.C.A., Vol. 22,
No. 9, September 1972.
(5) Klosterman, T.L. and J. F. Slqsby, Jr., "Application of Subtractive
Technigues to the Analysis of Automotive Exhaust", Environmental Science
and Technology, Vol. 1, No. 4, April 1967.
-11-
-------
AMC7010.T0108F-FCR
aromatics. Both of these reports deal with scrubbing systems using sulfuric
acid and mercury and palladium sulfates on some support medium. Should further
analysis of hydrocarbon emissions in St. Louis be desired, an adaptation of
these two methods would probably be used. The analysis method developed under
this Task for methane and non-methane could be easily altered to add a
scrubbing system for more detailed analysis.
-12-
-------
AMC7010.T0108F-FCR
APPENDIX I
SOURCE CLASSIFICATION CODE (SCC) LISTING VERSUS PERCENTAGE
CLASSIFICATION OF METHANE AND NON-METHANE HYDROCARBONS
-13-
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AMC7010.T0108F-FCR
SOURCE CLASSIFICATION CODE LISTING WITH METHANE,
NON-METHANE BREAKDOWN*
Hydrocarbons
SCC Number
1 01 002
1 01 002
1 01 002
1 01 002
1 01 004
1 01 004
1 01 005
1 01 005
1 01 006
1 01 006
1 02 002
1 02 002
1 02 002
1 02 002
1 02 002
1 02 002
1 02 002
1 02 004
1 02 004
1 02 004
1 02 005
1 02 006
1 02 006
1 02 006
1 02 007
1 02 007
1 03 002
1 03 002
1 03 004
1 03 004
1 03 005
1 03 006
01
02
03
08
01
07
01
02
01
02
02
04
05
06
08
09
12
01
02
03
02
01
02
02
01
08
09
13
01
02
02
01
Methane, %
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
78
Non-Methai
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
22
*Note: Only SCC codes are listed for which there are hydrocarbon emission
located in the St. Louis AQCR,
-14-
-------
AMC7010.T0108F-FCR
SCC Number
1 03 006 02
2 01 001 01
2 01 002 01
3 03 003 01
3 06 001 02
3 06 001 03
3 06 001 04
3 06 001 07
3 06 001 08
3 06 001 09
3 06 002 01*
3 06 009 99
3 09 002 01
3 90 004 08
3 90 004 30
3 90 004 99
3 90 006 05
3 90 006 08
3 90 006 30
3 90 006 99
4 02 004 01
4 02 005 01
4 03 001 01
4 03 001 03
4 03 001 07
4 03 001 52
4 03 002 01
4 06 001 26
4 06 002 01
5 01 001 01
*Source Test Data used to determine breakdown
Methane,
78
78
78
0
78
78
78
78
78
78
20
78
78
78
78
78
78
78
78
78
2
2
2
2
2
2
2
2
2
78
Hydrocarbons
% Non -Methane, %
22
22
22
100
22
22
22
22
22
22
80
22
22
22
22
22
22
22
22
22
98
98
98
98
98
98
98
98
98
22
-15-
-------
AMC7010.T0108F-FCR
APPENDIX II
CHROMATOGRAPHIC METHOD FOR SEPARATION OF METHANE
AND NON-METHANE HYDROCARBONS
-16-
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AMC7010.T0108F-FCR
TABLE OF CONTENTS
PAGE
1.0 INTRODUCTION 20
2.0 SUMMARY 21
3.0 SYSTEM DESIGN 22
4.0 TOTAL HYDROCARBON ANALYSIS 25
4.1 ANALYSIS PROCEDURE 25
4.2 REPRODUCIBILITY OF ANALYSIS 25
4.3 LINEARITY WITH RESPECT TO CARBON NUMBER 27
4.4 LINEARITY WITH RESPECT TO CONCENTRATION AND LIMITS
OF DETECTION 31
4.5 EFFECT OF OXYGEN IN THC ANALYSIS 35
4.6 PREPARATION OF STANDARDS 35
4.7 BAG DIFFUSION 37
5.0 METHANE ANALYSIS 38
5.1 ANALYSIS PROCEDURE 38
5.2 REPRODUCIBILITY OF ANALYSES 38
5.3 LINEARITY OF CONCENTRATION 38
5.4 INTERFERENCE OF METHANE ANALYSES 39
5.5 PREPARATION OF STANDARDS 39
5.6 BAG DIFFUSION 39
-17-
-------
AMC7010.T0108F-FCR
TABLES
PAGE
TABLE 1 CONCENTRATION AND DETECTION LIMITS 28
-18-
-------
AMC7010.T0108F-FCR
FIGURES
FIGURE 1 SYSTEM DESIGN
FIGURE 2 REPRODUCIBILITY OF RESULTS, CHROMATOGRAM
FIGURE 3 CHROMATOGRAM OF BUTANE VERSUS METHANE, UN-MODIFIED (FID)
FIGURE 4 CHROMATOGRAM OF BUTANE VERSUS METHANE, MODIFIED (FID)
FIGURE 5 CHROMATOGRAM OF TOLUENE VERSUS METHANE, UN-MODIFIED (FID)
CARRIER FLOW
FIGURE 6 CHROMATOGRAM OF TOLUENE VERSUS METHANE, MODIFIED AIR
CARRIER FLOW
FIGURE 7 GRAPH OF CARBON NUMBER LINEARITY
FIGURE 8 OXYGEN EFFECT IN SAMPLE ANALYSIS
FIGURE 9 REPRODUCIBILITY OF METHANE ANALYSIS
FIGURE 10 GRAPH OF METHANE CONCENTRATION VERSUS PEAK HEIGHT
FIGURE 11 CHROMATOGRAM OF METHANE AND ETHANE
PAGE
23
26
29
30
32
33
34
36
40
41
42
-19-
-------
AMC7010.T0108F-FCR
1.0 INTRODUCTION
In compliance with Task F of Task Order 108, a method was developed to
analyze stack samples for methane and total hydrocarbons at expected stack con-
centrations (10 ppm to Ippm). It was important that the analysis be rapid
(<15 minutes per complete analysis), reproducible, linear with respect to car-
bon number, linear with respect to concentration, and that the instrumentation
remain a stable, maintenance-free system. It was also important that, should
it later become necessary, stack sample analysis could be further divided into
reactive, non-reactive, or individual hydrocarbon constituents. With these
considerations the following analytical system was developed.
-20-
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AMC7010.T0108F-FCR
2.0 SUMMARY
Using a Gow-Mac series 750 gas chromatograph (G.C.), fitted with a flame
ionization detector (FID), an analysis system for methane and non-methane
hydrocarbons in stack samples was designed. This system, upon modification
proved to be linear with respect to carbon number and hydrocarbon concentra-
tion up to the level of 3.5 x 10 ppm per carbon number. Normally total
hydrocarbons are not linear with respect to carbon number, as increasingly
heavier hydrocarbons burn less efficiently. Modification to the Gow-Mac
750 G.C. produced a very efficient combustion flame, which resulted in a
1inear response.
A mode-select valve is used to change from the methane to the non-methane
mode. Should further breakdown of hydrocarbons be required, selective scrubbers
and/or different analytical columns could be installed.
All results were read on a Linear Instruments chart recorder attached to
the Gow-Mac electrometer. All results are reported in peak height, which is
linear with respect to hydrocarbon concentration.
Teflon bags were found to be both suitable for sampling and preparation of
standards within acceptable levels of error (—3%).
-21 r
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AMC7010.T0108F-FCR
3.0 SYSTEM DESIGN
As previously mentioned, modifications to the Gow-Mac 750 G.C. were
necessary to insure accurate and meaningful results for methane and total
hydrocarbon analyses. All modifications may be seen in Figure 1.
The final operating parameters are as follows: The gases needed to maintain
a flame for the FID are oxygen (Linde hydrocarbon free) and hydrogen (Linde
ultra high purity). Both gases were passed from their respective cylinders by
single stage regulators, through particulate filters, and flow restrictive
capillaries [0.025 cm (0.01 in.) ID]. Parameters for oxygen flow were 0.70
2
kg/cm (10 psi) across 0.61 m (2 ft.) of capillary tubing to produce a flow
2
of 40 ml/min. Those for hydrogen are 3.5 kg/cm (50 Ibs.) across 3.0 m
(10 ft.) of capillary to produce a flow of 30 ml/min. Air (Linde hydrocarbon
free) is used to sweep the sample through the analytical system. An outlet
2
pressure of 3.5 kg/cm (50 psi) across a particulate filter and a flow control
valve, produces a total flow across two capillaries of 50 ml/min. A shorter
capillary (0.305 m - 1 ft.) was used to supply a constant air supply to the
FID to aid in flame combustion. The longer (0.61 m) capillary is used to
lessen the flow transients when the inject valve is activated.
The changing of the mode valve (Figure 1) allowed a 50-200 mesh activated
charcoal column .32 x 61 cm (1/8" x 2 ft.) to be placed in series with the
61 m capillary column. This charcoal column was used to separate methane
from other hydrocarbons.
The inject-load valve was used to sweep a sample from a 0.1 ml sample loop.
In the load position a vacuum pump continuously draws a sample through the
sample loop. When placed in the inject position, the sample in the sample
loop is forced either through the charcoal column and the .61 m capillary
(methane analysis), or directly through the .61 m capillary to the detector
(total hydrocarbon analysis).
The entire equipment enclosed in the area marked oven (Figure 1) was kept
at 100°C to insure that no hydrocarbons condensed in any part of the analytical
system. The detector was maintained at 125°C to insure no sample condensation
did occur in the detector.
-22-
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AMC7010.T0108F-FCR
o:
UJ
o
oo
>-
oo
o:
ct: c
UJ H-
o «=c
C3
LU
CO OC
< I-
o
OL
-------
AMC7010.T0108F-FCR
All plumbing and Swaqelok fittinqs were stainless steel. The injection
load and mode select valves were both Carle valves fitted with Teflon seats.
All plumbing parts were washed with acetone to remove any contaminates which
could cause interferences.
While this system was not designed to do any analyses other than methane
and non-methane, a further breakdown of total hydrocarbons could be accomplished
by adding selective scrubbers to the sample inlet line, prior to the sample
loop. This method could be used to break hydrocarbon classification down
to reactive and non-reactive hydrocarbons; reactive hydrocarbons being
defined as unsaturates, excluding acetylene, and aromatics, excluding benzene.
Should specific analyses of hydrocarbons be required, replacement of the
activated charcoal column with a different type of column could result in
a specific hydrocarbon analysis.
-24-
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AMC7010.T0108F-FCR
4.0 TOTAL HYDROCARBON ANALYSIS
This section describes the methods, difficulties, interferents, and
their removal, concerning the analysis for total hydrocarbons. To the writers'
knowledge, an accurate measure of total hydrocarbons has never before been
performed. In the past, instruments have been able to measure total hydro-
carbons accurately only when the entire sample was composed only of methane.
These analyses were also highly susceptible to oxygen content in the sample.
With the method developed under this Task Order, total hydrocarbons can
be measured accurately to the concentration of their carbon number, and
with no interference from the oxygen content in the sample.
4.1 ANALYSIS PROCEDURE
To commence an analysis for total hydrocarbons, a sample or standard is
attached to the sample inlet line of the G.C. and the sample vacuum pump
switched on (see Figure 1). With the inject-load valve in the load position
and the mode select valve in the THC position, the sample loop is filled with
sample, as air (Linde hydrocarbon-free) is injected into the FID. This air
is used to aid in combustion at the FID and to sweep the sample loop when the
inject-load valve is turned to the inject position. Approximately 5.5 seconds
after injection, a THC peak occurs as hydrocarbons from the sample loop are
burned. The inject valve should remain in the inject position until the entire
THC peak has returned to base line. This allows the entire sample loop to be
purged into the FID. By returning the inject-load valve to the load position,
a new sample is loaded into the sample loop in preparation for a new analysis.
The results are determined by peak height, read directly on a chart
recorder attached to the G.C. electrometer (Figure 2).
4.2 REPRODUCIBILITY OF ANALYSES
Numerous checks were performed to insure reproducibility of analyses.
Figure 2 indicates that a 1600 ppm methane sample provided peaks with identical
heights for more than one analysis.
-25-
-------
AMC7010.T0108F-FCR
J __ i I i_ __[
i ' / T __mt |^_" i
i ; ; \ j .
-i r •
FIGURE 2
REPRODUCIBILITY OF RESULTS, CHROMATOGRAM
-26-
-------
AMC7010.T0108F-FCR
Additional samples containinq varying amounts of m-xylene, toluene,
butane, and methane, all showed reproducibility over short periods of time.
With the exception of methane (Table 1), reproducibility was not attainable
over extended periods (>1 hr.) due to bag diffusion. It was found if the
inject-load valve held in the inject position for less than 5 seconds, all
of the hydrocarbons were not swept from the sample loop. This produced
varying hydrocarbon peak heights. A guideline, as mentioned previously, is
for valve activation until the THC peak returns to baseline.
4.3 LINEARITY WITH RESPECT TO CARBON NUMBER
A meaningful response of a THC analyzer can be attained only if all of
the hydrocarbons entering the FID are completely burned. When such is the
case, the output response is linear with respect to carbon number. If such
were not the case, different hydrocarbons would give different responses for
the same concentration per carbon number. Ideally, 100 ppm butane would give
the same response as 400 ppm methane, 100 ppm benzene as 600 ppm methane, and
100 ppm acetylene as 200 ppm methane. The amount of response would continue
to be a function of concentration and carbon number for all hydrocarbons.
Initially the Gow-Mac 750 G.C. was set at the manufacturer's recommended
settings of 30 ml/min H^, 450 ml/min burner air, and 30 ml/min air carrier.
The results for a 100 ppm butane sample produced less than the sample response
for 400 ppm methane (Figure 3). As the mechanics for hydrocarbon burning
involved in the carrying of current from the electrically positive flame to
a negative collector are:
CH + 0 -> CHO+ + e~
it was felt that increasing the oxygen supply would aid in combustion. Figure
4 gives an example after oxygen had replaced air as a burner support gas.
This enables the butane to be burned completely, giving a linear response with
respect to carbon number. The burner oxygen rate was initially set at 40 ml/min.
To insure that the complete burning of butane could be applied also to
other hydrocarbons, a second hydrocarbon was chosen to test. Toluene was
-27-
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AMC7010.T0108F-FCR
CONCENTRATION
1000 ppm Toluene
526 ppm Toluene
200 ppm Toluene
100 ppm Toluene
700 ppm Methane
TABLE 1
CONCENTRATION AND DETECTION LIMITS
RANGE AND
ATTENUATION
10-"10 x 8
1Q-10 x 8
10"10 x 8
10"10 x 4
10
-10
x 4
INITIAL
RESULT
(mm)
72.0
46.0
18.5
18.0
18.5
FINAL RESULT
AFTER 18 MRS.
(mm)
67.0
43.0
17.0
16.0
18.5
DECREASE
7.5%
7.0%
8.8%
12.5%
0.0%
-28-
-------
AMC7010.T0108F-FCR
TvT
-i _
Oi
4-
tfr-
«-
r#-
QA
i
-4--
3t23
FIGURE 3
CHROMATOGRAM OF BUTANE VERSUS METHANE, UN-MODIFIED (FID)
-29-
-------
AMC7010.T0108F-FCR
FIGURE 4
CHROMATOGRAM OF BUTANE VERSUS METHANE, MODIFIED (FID)
-30-
-------
AMC7010.T0108F-FCR
selected as it is a hydrocarbon likely to be encountered in future sampling,
and it is a difficult hydrocarbon to burn completely. If this aromatic com-
pound should prove linear with carbon number, it could be assumed that any other
hydrocarbon would be completely burned in a FID. Figure 5 indicates that
100 ppm toluene gave 10% less response than 700 ppm methane. This indicates
that not all of the toluene is being burned completely. The hydrogen and
oxygen gases used for the FID were adjusted both upward and downward from 30
ml/min and 40 ml/min respectively. No adjustment in oxygen or hydrogen helped
in giving the desired equal results for equal carbon number concentration
amounts of methane and toluene.
The one remaining parameter which could be modified in an attempt to attain
100% combustion of toluene was the carrier air. When the carrier air was in-
creased from 30 ml/min to 40 ml/min, 100 ppm toluene gave the same response as
700 ppm methane. Further increases in carrier air eventually resulted in flame
blow out at 70 ml/min. 50 ml/min was finally settled upon as an ideal flow
rate to insure complete combustion and a stable flame. Figure 6 shows equal
responses for 100 ppm toluene and 700 ppm methane. Additional experiments
using various concentrations of toluene versus methane showed a continued
linear response with respect to carbon number. Tests performed with m-xylene
and methane also showed the complete combustion of m-xylene under the given
operating parameters.
As a possible explanation of the above results, it is suqqested that the
replacement of burner air with oxygen greatly facilitated the formation of
the CHO radical needed to give a hydrocarbon response. Nitrogen molecules
no longer interfered with the contact of oxygen and carbon atoms needed to
form CHO . The added oxygen from the air carrier plus the increase in flame
turbulence at higher flow rates would seem to enhance CHO formation. These
two factors have enabled a totally efficient combustion to be produced.
4.4 LINEARITY WITH RESPECT TO CONCENTRATION AND LIMITS OF DETECTION
Toluene was used to prepare a wide range of standards to determine if the
FID output was linear. Figure 7 shows a graph of concentrations plotted
against peak height. As may be seen, the instrument is linear with respect
-31-
-------
AMC7010.T0108F-FCR
FIGURE 5
CHROMATOGRAM OF TOLUENE VERSUS METHANE, UN-MODIFIED CARRIER FLOW
-32-
-------
AMC7010.T0108F-FCR
T"
E
—!
I in
-£-
FIGURE 6
CHROMATOGRAM OF TOLUENE VERSUS METHANE, MODIFIED AIR CARRIER FLOW
-33-
-------
Q
O
O
o-
AMC7010.T0108F-FCR
O 700
FIGURE 7
GRAPH OF CARBON NUMBER LINEARITY
-34-
-------
AMC7010.T0108F-FCR
3
to concentration up to 3.5 x 10' ppm carbon number. It would appear that
at this point detector saturation begins to occur. When a larger sample loop
was inserted to replace the 0.1 cm loop, detector saturation occurred at a
much lower concentration. The 0.1 cm' sample loop does have limitations that
larger loops do not. The lower detection limit for a 0.1 cm sample loop is
1 ppm per carbon number, while a 1.0 cm loop has a lower detection limit of
0.1 ppm per carbon number.
The 0.1 cm sample loop is the smallest that can be used on the Gow-Mac
3
750. Should hydrocarbon concentrations exceed 3.5 x 10 ppm per carbon
number, the only accurate method to analyze a sample would be sample dilution.
This would entail using a known volume of pure air and a syringe injected
volume of sample gas By knowing the resulting peak height and the amount of
sample dilution, an accurate result could be obtained for the sample even if
3
it exceeded 3.5 x 10 ppm per carbon number.
4.5 EFFECT OF OXYGEN IN THC ANALYSIS
From work performed in the RAMS network, it is known that THC results are
a function of the percent oxygen in the sample being analyzed. Samples that
are rich in oxygen (relative to the air carrier) give erroneously high readings,
and those deficient in oxygen give results that are erroneously low. These
results were obtained for the Gow-Mac 750 prior to the use of oxygen to support
combustion and the proper adjustment of the air carrier.
The results of an experiment to show whether the Gow-Mac was still
susceptible to sample oxygen content is shown in Figure 8. The gases used
are Scott ultra pure air, which has an oxygen content of 19%, and U.S. Bureau
of Mines helium which has no oxygen content. At a very sensitive instrument
attenuation and range, no difference in result can be seen. Irregularities
in the chromatograph are caused by pressure surges due to sample injections.
4.6 PREPARATION OF STANDARDS
Standards were prepared in leak tested 5 mil Teflon bags. These bags were
purged with high-purity helium (NBM) and evacuated orior to use. A bag was
then filled with a desired volume of pure air (Linde zero grade) using a
-35-
-------
AMC7010.T0108F-FCR
FIGURE 8
OXYGEN EFFECT IN SAMPLE ANALYSIS
-36-
-------
AMC7010.T0108F-FCR
mass-flow meter. All precautions were taken to insure that no leaks were
present on filling. While Linde zero air is not totally free of hydrocarbons,
the amount is less than 1 ppm THC and 0.1 x 10 ppm methane. These concen-
trations are below the lower detection limits of the instrument. The filled
Teflon bag was then injected through a silicone septum with a known amount
of hydrocarbon using a precision syringe to attain the desired concentration.
Hydrocarbon concentration should be presented in terms of ppm of carbon.
number. This may be determined by knowing the type and amount of hydrocarbon
injected into the standard bag and multiplying this concentration by its
number of carbon atoms per molecule. 2 x 16~ ppm m-xylene would be expressed
as: 2x8=16 ppm of carbon number. The 10" ppm per carbon number is
identical to the more common total hydrocarbon term, "ppm expressed as methane'
4.7 BAG DIFFUSION
Tests were performed using various amounts of toluene and methane to
determine if and at what rate these compounds permeate through Teflon bags.
The results are shown in Table 1. These results are in agreement with
the findings of T.O. 103 concerning bag diffusion; that heavier hydrocarbons
permeate faster than lighter ones. As all bag samples will be collected and
analyzed within 6 hrs., the expected error would be less than 3% of the total
concentration. This amount of error is acceptable for this type of analysis
for high hydrocarbon concentrations.
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5.0 METHANE ANALYSIS
The following concerns the analysis of methane in stack samples.
This type of analysis is very simple and has been performed using many
different types of analytical procedures. The method mentioned in this report
is capable of methane analysis from 1 ppm to 5.0 x 10^ ppm. This is well
within any level likely to be encountered in stack samples.
5.1 ANALYSIS PROCEDURE
To commence an analysis for methane, a sample or standard is attached
to the sample inlet line of the G.C. and the sample vacuum pump switched
on (See Figure 1). Mith the inject-load valve in the load position and the
mode select valve in the methane position, the sample loop is filled with
sample as air (Linde hydrocarbon free) is injected into the FID. This air
is used to sweep the sample loop when the inject-load valve is turned to the
inject position. Approximately two minutes after sample injection occurs,
a methane peak occurs as methane from the sample loop is burned. The inject
valve should remain in the inject position for 15 seconds to insure that
all of the sample in the sample loop has been swept into the analytical
column. By returning the inject-load valve to the load position, a new
sample is loaded into the sample loop in preparation for a new analysis.
The results are determined by peak height, read directly on a chart
recorder attached to the G.C. electrometer.
5.2 REPRODUCIBILITY OF ANALYSES
Figure 9 shows a chromatogram of three injections of 200 ppm methane.
All injections had the same peak heights. The results of methane chromato-
grams over an 18 hour period indicate that the methane analyses are totally
reproducible.
5.3 LINEARITY OF CONCENTRATION
Linearity checks were performed using various concentrations of methane.
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Up to the level of 5.0 x 10 ppm, no detector saturation was seen (Figure
10). As methane would never likely be seen at concentrations close to this
figure, no attempt was made to determine at what level detector saturation
for methane would occur.
5.4 INTERFERENCE OF METHANE ANALYSES
Activated charcoal was chosen as a chromatographic column for the
analysis of methane because it has a very poor retention of methane with
an excellent retention of other hydrocarbons. The hydrocarbon with the
poorest retention next to methane is ethane. It was felt that if proper
resolution of ethane from methane could be attained, no other hydrocarbon
would interfere with methane resolution. Figure 11 is a chromatogram of
a spike amount of ethane versus 30 ppm methane. The chromatogram shows that
ethane elutes at 20 min. with a very broad peak, compared with the sharp
methane peak at 2 min. Thus, no interference from ethane or any other hy-
drocarbon will occur.
5.5 PREPARATION OF STANDARDS
Standards were prepared as in Section 3.8, with the exception that
the only hydrocarbon used is methane.
5.6 BAG DIFFUSION
See Section 3.9 and Table 1.
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FIGURE 9
REPRODUCIBILITY OF METHANE ANALYSIS
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o
o
'JOOO
FIGURE 10
GRAPH OF METHANE CONCENTRATION VERSUS PEAK HEIGHT
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APPENDIX III
HYDROCARBON SOURCE TESTS
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TABLES
PAGE
TABLE 1 HYDROCARBON ANALYSES 45
TABLE 2 HYDROCARBON ANALYSES 45
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