United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S7-87/015 Sept. 1987
Project Summary
Criteria Pollutant Emission
Factors for the 1985 NAPAP
Emissions Inventory
Margie B. Stockton and John H. E. Stalling
As part of the National Acid Precip-
itation Assessment Program (NAPAP),
the U.S. Environmental Protection
Agency (EPA) identified the need to
generate emission factors for volatile
organic compound (VOC) emissions for
about 1,800 source classification
categories (SCCs). Additionally, emis-
sion factor development was needed
for nitrogen oxides (NOJ, sulfur oxides
(SO,), and VOCs for SCCs that states
have used to report emissions. Each
SCC represents a specific process or
function that is logically associated
with a point source of air pollution. The
objective of this effort was to estimate
VOC emission factors for all SCCs
where VOC factors were previously
absent, and to develop NO, and SO,
emission factors for SCCs that states
had reported as emission sources. This
report includes emission factor esti-
mates for VOCs, NOX, and SO, which
were developed from a variety of
readily available information. Emission
factors for particulate matter (PM) and
carbon monoxide (CO) from AP-42
Fourth Edition and Supplement A are
also presented. Data gathered during
numerous standards-setting activities
as well as data provided from state
emissions inventory data bases were
used to calculate the new emission
factor estimates. Technology transfer
of emission factors for similar pro-
cesses in different industries provided
emission factor estimates for source
categories where no data were avail-
able. A list of all valid SCCs used in
the 1985 NAPAP Emissions Inventory,
as well as about 90 SCCs which have
been added to the inventory since
October 1985, is included along with
all emission factor estimates developed
through April 1987.
This Project Summary was devel-
oped by EPA's Air and Energy Engi-
neering Research L aboratory, Research
Triangle Park, NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
As part of the National Acid Precipi-
tation Assessment Program (NAPAP), the
Air and Energy Engineering Research
Laboratory (AEERL) of the U.S. Environ-
mental Protection Agency (EPA) updated
the October 1985 NEDS Source Classi-
fication Codes and Emission Factor
Listinglhat was prepared by EPA's Office
of Air Quality Planning and Standards
(OAQPS). In Phase I of the update,
volatile organic compounds (VOC) emis-
sion factor estimates were generated for
source classification categories (SCCs)
where substantial amounts of VOC
emissions were expected. The major
emphasis of that effort was on organic
chemical manufacturing processes and
storage of petroleum products and
organic chemicals. This report describes
Phase II of the update which consisted
of developing VOC emission factor
estimates for all remaining SCCs. Addi-
tionally, state air offices have reported
to the National Emissions Data System
(NEDS) on emissions from point sources
within their states. The SCCs appearing
in these reports which previously lacked
emission factors were targeted as high
priority SCCs for the development of
-------
VOC, nitrogen oxide (NOX), and sulfur
oxide (S0») emission factors.
The SCCs and emission factors that are
reported in OAQPS' 1985 NEDS report
resulted from updating all emission
factor changes through AP-42, Fourth
Edition. During this effort, the SCC listing
was revised to incorporate all changes
through Appendix Ato A P-42 (December
1986). This report also contains a
number of new SCCs and changes to
existing SCCs that have been previously
listed. A list of all SCCs and emission
factors published in the 1985 NEDS
document, as well as the emission factor
estimates developed during Phases I and
II of the update, are included in this
report
In the current work by AEERL, the
primary objective was to provide VOC
emission factor estimates for all SCCs
that had no current listing of VOC
emission factors Also included in this
work was the development of NOx and
SOX emission factor estimates for SCCs
which were included in reports submit-
ted by states that previously lacked these
factors. The new emission factor esti-
mates resulting from this current work
are not of the same.known quality as
emission factors tabulated in AP-42.
They represent best estimates which
have not been subjected to rigorous
quality assurance. These factors were
generated from estimates taken from the
literature, from averaging of data sub-
mitted by 13 state air quality offices, and
through the transfer of emission factors
for SCCs from similar industries. Exten-
sive notes and references are supplied
in an appendix explaining how the new
emission factor estimates were gener-
ated. In some cases, these notes indicate
data quality by reporting the number of
emission tests used to develop a factor.
State Contacts
Thirteen states were contacted to
obtain emission data from emission
inventories, test reports, and permit files.
States which have large industrial
sectors and potentially large emission
sources were specifically targeted during
this effort. Emissions data were supplied
by 12 of the states, 7 through compu-
terized emissions inventories and 5
through review of permit files. Emission
factors were estimated by averaging the
emissions data submitted for each SCC.
In some cases, states or industries were
recontacted to provide more complete
process descriptions and production
rates. States provided a substantial
amount of emissions data on metal
operations (both primary and secondary)
and on mineral products operations.
Literature Review
A number of source specific docu-
ments, including Background Informa-
tion Documents (BIDs), Industrial Pro-
cess Profiles, Source Assessments, and
chemical specific emission source survey
documents were reviewed to gather
information on emissions and processes.
These documents provided useful infor-
mation on process descriptions, operat-
ing parameters, raw materials, and end
products for many source categories.
This information was used to compare
similar processes in different industries
in order to transfer emission factors
across industries where appropriate. The
Industrial Process Profiles, although
somewhat outdated (published in 1977
and 1980), proved especially useful for
this exercise.
State Reports Requiring Emis-
sion Factor Calculations
In 1985, EPA asked states to submit
emissions data for large sources of
criteria pollutants, emphasizing SO,,
NOx, and VOC emissions from sources
emitting over 100 tons/year. Source test
emissions data have been submitted, as
well as emission estimates based on AP-
42 emission factors or engineering
judgment. Where no emission factors
were available, states have requested
that emissions be calculated for them by
the NEDS, using emission factors already
in the system for an SCC. Where no
emission factors have ever been
reported, the SCCs were flagged for
emission factor development as a high
priority for this work assignment.
Results
At the completion of the Phase II effort,
99% (2725) of the SCCs have VOC
emission factors or emission factor
estimates associated with them or do not
need emission factors due to their
general description. Of these, 37%
(1006) were developed during this effort.
Emission factors for NOx and S0» are
included for 75% of the SCCs in the list.
Table 1 summarizes the emission factor
development for the SCCs currently in
NEDS and breaks down progress by
major source category. During this effort,
over 100 VOC emission factors were
developed in the following major source
categories: chemical manufacturing.
primary metals operations, and secon- I
dary metals operations.
Forty-six states reported on emissions
for SCCs in which emission factor
development was necessary for NO,,
SOX, and VOC. Emission factors for 293
SCCs were included in these reports. Of
the 293 SCCs for which factors were
needed, 130 NO, emission factors (98%
of the NOX requests) were developed, 128
SO, emission factors (99% of the SO,
requests) were developed, and 1 69 VOC
emission factors (100% of the VOC
requests) were developed. These emis-
sion factors are based on data supplied
in published literature and the transfer
of existing factors from similar pro-
cesses. Many of the state submittals
were received late in the project, and
emission factor development is on-going.
Two states had not yet submitted emis-
sions data to NEDS as of April 30, 1987.
In its final form, this document will
address all SCCs for which state reports
on emissions require emission factor
development.
Recommendations
Recommended activities for future
study include the development of addi-
tional NOx and SO, emission factor
estimates. The approach would be sim-
ilar to that used for VOCs. Further review
of data which have been collected from
states and the literature may help
estimate additional NOX and SO, emis-
sion factors. Source categories targeted
are chemical manufacturing industries
and primary and secondary metals
industries.
The emission factors developed during
this effort are considered of "E" quality
by AP-42 standards primarily because
they are of unknown or uncertain quality.
In some cases, the factors may be of
much higher quality; however, the data
should be reviewed and verified before
higher ratings are applied. Emissions
testing is recommended for improving
some of these "E" rated factors, with
emphasis on testing of sources with large
VOC emission factors. Identification of
the SCCs for which testing is desirable
should be included in future work.
Emission factor development needs for
particulate matter (PM) and carbon
monoxide (CO) should be identified to
determine the amount of additional work
necessary if filling of emission factor
gaps for SCCs for these two pollutants
is desired.
-------
Table 1.
Summary of Emission Factor Development
Major Source Category
Combustion Sources
Chemical Manufacturing
Inorganic Chemical Storage
Food and Agricultural
Primary Metals
Secondary Metals
Mineral Products
Petroleum Operations
Pulp and Paper
Rubber and Plastics
Fabricated Metals
Oil and Gas Production
Textiles
Organic Solvent Evaporation
Petroleum Storage
Chemical Storage
Solid Waste Disposal
Other"
Total SCCs
in Category
190
723
28
151
223
215
387
56
87
38
52
29
21
270
139
289
62
197
SCCs for Which
Emission Factors
are Inappropriate"
8
70
6
22
13
20
31
8
26
7
19
8
12
41
17
52
4
35
SO, Emission
Factors
(% Completed)"
1 79 (98%)
1 79 (34%)
15 (75%)
102(82%)
142 (70%)
126 (68%)
321 (91%)
39 (84%)
51 (89%)
6 (34%)
24 (83%)
12 (69%)
0(0%)
229(100%)
122(100%)
237(100%)
45 (79%)
145(91%)
/VOX Emission
Factors
(% Completed)"
177/97%)
192 (36%)
18(86%)
102(82%)
120(60%)
131 (70%)
328 (93%)
39 (84%)
52 (90%)
6 (34%)
26 (86%)
1 1 (66%)
0(0%)
229(100%)
122(100%)
237(100%)
44 (77%)
142 (90%)
VOC Emission
Factors
(% Completed)"
182(100%)
612(94%)c
26(100%)
129(100%)
210(100%)
195(100%)
354(100%)
48(100%)
65(100%)
31 (100%)
35(100%)
21 (100%)
9(1 OO%)
229(100%)
122(100%)
237(100%)
58 (100%)
162(100%)
Total
3157
399
1974(75%)
1976(75%)
2725 199%)
"These include the "General Processes" (-01) codes, the "Other/Not Classified" (-98. -99) codes, and "Specify in Comments" (-888) codes.
These percentages include SCCs for which emission factors have been developed and SCCs for which emission factor development is not
required (see note a).
"Emission factors for fugitives cannot be developed until nationwide equipment counts become available for each chemical manufacturing industry
""Other" category includes numerous small categories such as building construction, electrical equipment, printing and publishing, and
photographic equipment.
-------
M. B. Stockton and J. H. E. Stelling are with Radian Corporation, Research
Triangle Park, CA 27709.
J. David Mobley is the EPA Project Officer (see below).
The complete report entitled "Criteria Pollutant Emission Factors for the 1985
NAPAP Emissions Inventory," (Order No. PB 87-198 735/AS; Cost: $24.95,
subject to change)
will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S Environmental Protection Agency
Research Triangle Park, NC 27711
•3C
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
OCr30-87
Official Business
Penalty for Private Use $300
EPA/600/S7-87/015
' 0000329 PS
"SENCr
------- |