United States Office of
Environmental Protection Research and Development
Agency Washington, DC 20460
EPA-600/R-94-012
January 1994
EPA Comparison of the 1985
NAPAP Emissions
Inventory with the 1985
EPA TRENDS Estimate for
Industrial SO2 Sources
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EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service. Springfield, Virginia 22161.
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EPA-600/R-94-012
January 1994
Comparison of the 1985 NAPAP Emissions Inventory
with the 1985 EPA TRENDS Estimate
for Industrial SO2 Sources
Final Report
Prepared by:
David Zimmerman
TRC Environmental Corporation
100 Europa Drive, Suite 150
Chapel Hill, NC 27514
and
Rebecca Battye
EC/R Incorporated
University Tower, Suite 404
3101 Petty Road
Durham, NC 27707
EPA Contract No. 68-D2-0181
Work Assignment Nos. 2 and 8
EPA Project Officer: Charles C. Masser
U.S. Environmental Protection Agency
Air and Energy Engineering Research Laboratory
Research Triangle Park, NC 27711
Prepared for:
U.S. Environmental Protection Agency U.S. Environmental Protection Agency
Office of Air Quality Planning and Office of Research and Development
Standards Washington, DC 20460
Research Triangle Park, NC 27711
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ACKNOWLEDGEMENTS
Special acknowledgements are to be made to Sue Kimbrough and Charles Mann in the
Emissions and Modeling Branch of AEERL for their insight and historical knowledge of
NAPAP and TRENDS and to J. David Mobley and his staff in the Emissions Inventory
Branch of OAQPS for their support in reviewing this document.
FOREWORD
This document compares results from 1985 EPA Emission TRENDS methodology
with 1985 NAPAP Emission Inventory methodology. Due to findings in this report as well as
other factors, the TRENDS methodology has been revised as of 1993; thus, references to
TRENDS in this report will no longer be valid for years 1985 and beyond, effective with the
1993 edition of the TRENDS report The new TRENDS methodology uses the 1985 NAPAP
Emission Inventory as a base. Further changes will be seen in the TRENDS reports published
in 1994 and thereafter. Thus, the reader is cautioned that comments on the EPA TRENDS
report in this document are valid for editions prior to 1993, but are not valid for the editions
1993 and thereafter.
11
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TABLE OF CONTENTS
Section Page
ACKNOWLEDGEMENTS ii
FOREWORD ii
LIST OF TABLES vi
LIST OF FIGURES vi
EXECUTIVE SUMMARY vii
SECTION 1 INTRODUCTION 1
SECTION 2 ANALYSIS OF 1985 TRENDS AND NAPAP ESTIMATES 5
2.1 COMBUSTION SOURCES 6
2.1.1 Oil Combustion 7
2.1.2 Coal Combustion 22
2.1.3 Anthracite Coal 23
2.1.4 Bituminous Coal and Lignite 25
2.1.5 Natural Gas 31
2.1.6 Miscellaneous Fuel 38
2.1.7 Wood 52
2.1.8 Other NAPAP Combustion Categories 57
2.2 NON-FERROUS SMELTING 57
2.2.1 Primary Copper 58
2.2.2 Combined Primary Lead and Primary Zinc 59
2.2.3 Primary Zinc 59
2.2.4 Primary Lead 63
2.2.5 Primary Aluminum 67
2.2.6 Secondary Lead 72
2.2.7 Other NAPAP Non-ferrous Emission Categories 75
2.3 OTHER INDUSTRIAL PROCESSES 75
2.3.1 Kraft Pulp Production 76
2.3.2 Chemical Manufacturing 83
2.3.3 Carbon Black Production 83
2.3.4 Sulfuric Acid 88
2.3.5 Sulfur Recovery Plants 93
2.3.6 Petroleum Refineries 98
2.3.7 Natural Gas Production 109
2.3.8 Iron and Steel 113
2.3.9 Cement Manufacturing 126
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TABLE OF CONTENTS
Section Page
2.3.10 Glass Manufacturing 131
2.3.11 Lime Manufacturing 134
2.3.12 Additional Industrial Process Emission Categories in the NAPAP
Inventory 137
SECTION 3 CONCLUSIONS 141
3.1 COMBUSTION SOURCES 142
3.2 COMBUSTION OF OIL 142
3.3 COAL COMBUSTION 144
3.4 NATURAL GAS COMBUSTION 146
3.5 MISCELLANEOUS FUELS 147
3.5.1 Coke 148
3.5.2 Coke Oven Gas 148
3.5.3 Kerosene 149
3.5.4 LPG 150
3.6 WOOD 150
3.7 NON-FERROUS SMELTING SOURCES 151
3.7.1 Primary Zinc 151
3.7.2 Primary Lead 152
3.7.3 Primary Aluminum 153
3.7.4 Secondary Lead 154
3.7.5 Other Non-ferrous Emissions Reported in NAPAP 154
3.8 OTHER INDUSTRIAL PROCESS EMISSION SOURCES 155
3.8.1 Kraft Pulp Production 155
3.8.2 Carbon Black Manufacture 156
3.8.3 Sulfuric Acid 157
3.8.4 Sulfur Recovery Plants 158
3.8.5 Petroleum Refineries 159
3.8.6 Natural Gas Production 161
3.8.7 Iron and Steel 162
3.8.8 Cement Manufacturing 163
3.8.9 Glass Manufacturing 164
3.8.10 Lime Manufacturing 165
SECTION 4 REFERENCES 166
APPENDIX A EPA TRENDS PROCEDURE FOR INDUSTRIAL SO2 EMISSIONS . . . A-l
Anthracite Coal A-l
Bituminous Coal and Lignite A-2
Residual Oil A-3
Distillate Oil A-4
Natural Gas A-5
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TABLE OF CONTENTS
Section Page
Miscellaneous Fuel A-6
Primary Copper A-10
Primary Zinc A-12
Primary Lead A-13
Primary Aluminum A-14
Secondary Lead A-15
Pulp and Paper A-15
Sulfuric Acid A-16
Carbon Black Production A-17
Sulfur Recovery Plants A-17
Petroleum Refining A-18
Iron and Steel A-19
Cement Manufacturing A-21
Glass A-22
Lime Manufacturing A-23
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LIST OF TABLES
Number Page
1-1 Magnitude Differences Between 1985 TRENDS and NAPAP SO2 Emission
Estimates 4
2-1 Emissions from Combustion TRENDS versus NAPAP 8
2-2 Comparison of Oil Combustion Values for 1985 TRENDS and NAPAP 12
2-3 Weighted Average Emission Factor for Distillate Oil Combustion 14
2-4 Comparison of Coal Combustion Values for 1985 TRENDS and NAPAP 22
2-5 Comparison of Natural Gas Values for 1985 TRENDS and NAPAP 31
2-6 Comparison of Miscellaneous Fuels Values for 1985 TRENDS and NAPAP .... 39
2-7 Weighted Average Emission Factor for Coke Combustion 43
2-8 Comparison of Non-Ferrous Smelting Values for 1985 TRENDS and NAPAP ... 58
2-9 Recovery of Sulfur as H2SO4 59
2-10 Other Non-Ferrous Emissions Reported in NAPAP 76
2-11 Comparison of Other Industrial Processes Values for 1985 TRENDS and
NAPAP 77
2-12 Emissions from Chemical Manufacturing Sources Included in NAPAP but not
in TRENDS 138
2-13 Emissions from Mineral Products Sources Included in NAPAP but not in
TRENDS 139
2-14 Emissions from Other Industrial Process Sources Included in NAPAP but not
in TRENDS 140
3.9-1 Weighted Average Emission Factors for Industrial Oil Combustion A-5
3.11-1 Weighted Average Emission Factors for Coke A-8
3.15-9 Capacity Data A_i(3
3.15-10 Smelting Emission Factor Data A_JJ
3.15-11 Converting Emission Factor Data A-12
3.15-12 Emission Factors for Uncontrolled Emissions * 99
3.15-13 Weighting Factors A --
*"*"*••••.»...... f\~'£3
LIST OF FIGURES
Number
Page
1 Cumulative sulfur dioxide emissions in the 1985 NAPAP inventory versus
number of plants
" * *.
vi
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EXECUTIVE SUMMARY
Section 406 of the 1990 Clean Air Act Amendments (CAAA) requires that the
Administrator of the Environmental Protection Agency transmit to Congress a report
containing a national inventory of annual sulfur dioxide (SO:) emissions from industrial
sources not later than January 1, 1995 for all years for which data are available, as well as the
likely trend in SO2 emissions over the following twenty year period (1995 to 2015). Under
the Act as amended, 1985 served as the baseline for the 5.6 million ton industrial SO:
emission estimate. To provide the 1995 analysis mandated by Congress, the 1985 baseline
data must first be examined to identify strengths and weaknesses in the available emission
and supporting data. This report presents the initial analysis of two major sources of baseline
industrial data available at this time: the 1985 National Acid Precipitation Assessment
Program (NAPAP) emission inventory and the 1985 national emission estimates, referred to
as the TRENDS emission estimates.
The 1985 NAPAP emission inventory effort supported acid precipitation deposition
research, including atmospheric modeling, through comprehensive, detailed source emission
estimates provided by local and state agencies. It is a "bottom-up" inventory and a 1985
snapshot The SO2 emission data for significant (>100 tons per year) sources were
systematically quality assured, with greater effort expended on larger sources. The inventory
included a unique confirmation step, allowing individual plants emitting at least 2500 tons per
year to review their emission estimates prior to finalization. The resulting inventory is widely
regarded as the most comprehensive and accurate national inventory compiled to date.
The TRENDS estimates represent both current and historic emissions (1940 to present)
and are compiled annually. Industrial emission estimates are derived from national, published
activity data and standard emission factors; historic estimates are altered based on the most
recent activity data and emission factors to better represent the most current understanding of
emission processes. It is essentially a "top-down" approach and not a true inventory. It
vu
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presents a consistently derived national emission estimate at the emission category level (e.g-,
industrial oil combustion) rather than the source (e.g., boiler) level.
The aim of this document is to analyze the derivation of individual industrial category
estimates from NAPAP and TRENDS. Such analyses are complicated by several factors:
NAPAP is comprehensive and includes all reported industrial emission
categories; TRENDS is limited to categories thought to emit at least 10,000
metric tons of a criteria pollutant per year.
NAPAP is source and plant specific; TRENDS is national and category-
specific. There is no opportunity to match individual data values between the
inventories; in fact, category definitions differ between the two inventories.
The 1985 NAPAP inventory is a single year inventory and is not updated;
TRENDS adjusts historical data based on the most current information.
A complete understanding of a NAPAP emission category could entail plant by
plant, source by source review of throughput data, control information, fuel
parameters, etc. Such an effort was not possible within the framework of this
project The TRENDS methods were reviewed, but still represent a large and
complicated set of data, methods and assumptions.
It is unavoidable but in a number of cases it is difficult if not impossible to compare
TRENDS and NAPAP on an even basis.
This document presents a highly detailed view of the two inventories on a category
basis, principally relying on emission and activity (throughput) data. Methods, data sources,
emissions and assumptions are documented and analyzed in as much detail as possible so that
this information need not be recompiled for future examination. The authors have attempted
to reproduce the 1985 TRENDS emissions estimates and noted any irregularities in the
calculated and published data. The analyses proved complex, especially when disaggregating
data to create comparable categories between NAPAP and TRENDS datasets, and raised a
number of questions. (In particular, categories with significant inprocess fuel emissions such
as cement proved difficult to assess because the process and fuel emissions were treated
differently in each dataset.) As such, most of the document is technical in nature and is
meant to be a reference tool as individual category methods and emissions are compared
viii
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during the development of the 1995 Report to Congress. Supporting data are consolidated
and provided in Appendix A.
Overall, the two 1985 estimates (NAPAP and TRENDS) compare favorably: NAPAP
estimates 5.6 million tons SO2 (as reflected in the Act as amended) and TRENDS estimates
6.0 million tons. When broken down, however, the two estimates show greater divergence
for individual categories. The TRENDS estimate is larger than the 1985 NAPAP estimate
and does not include as many source categories. The TRENDS estimate systematically
overestimates emissions, relative to the NAPAP inventory, and therefore on aggregate the
estimates are very similar. The primary reason for the overestimation in the TRENDS
method is the exclusion of SO2 control technology that has come into being over the years.
SO2 control technology has been applied to the majority of the large industrial SO2 categories
through the promulgation of New Source Performance Standards (NSPS), issuance of
operating permits, and New Source Review Permits. Several categories exceeding 100,000
tons of SO2 differ by more than 50 percent between the two datasets:
• Primary lead and zinc
• Iron and steel
• Oil and natural gas production
• Pulp and paper
• Cement
In general terms, the authors drew the following conclusions from the analyses of the
two datasets. These conclusions are based on an analysis of the 1985 NAPAP SAS® data
files (annual files) and the published TRENDS methods and emissions data.
NAPAP
The 1985 NAPAP inventory still represents the most comprehensive and
accurate emissions estimates for 1985 because of its unprecedentedly rigorous
quality assurance of emissions and bottom-up nature. The inventory accounts
for individual source operating characteristics, controls and emission factors.
IX
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Activity data in the 1985 NAPAP inventory were not subject to the same
standard of quality assurance or completeness. Some data were unreported due
to confidentiality restrictions and activity data for small sources (i.e., <100 tons
per year) passed only the grossest quality assurance checks. There are known
reporting problems among miscellaneous fuels and other categories. The
accuracy and representativeness of activity data in the NAPAP inventory are
best evaluated source by source; category-level summaries are unreliable
without adjustments.
It is still very possible to locate questionable data values in the 1985 NAPAP
emission inventory when examined on a source by source basis, especially for
smaller emitters.
TRENDS
Some industrial emission categories, notably processes within oil and natural
gas production, are missing from the TRENDS method.
As a top-down approach, broad assumptions of emission factors and controls
are used across a category. Frequently, estimates make no adjustment for
controls and accommodation for individual operating characteristics, including
emission factors, is impossible.
For the most part, the underlying industrial activity data are reliable and
probably far superior to the corresponding NAPAP estimates at the category
level. Any method for 1995 and beyond should take advantage of the
underlying data sources.
Based on the TRENDS documentation, the actual TRENDS execution contains
minor to moderate errors in calculation of activity and emissions. As such,
some sections of this report related to the calculation of the TRENDS emission
estimate are internally inconsistent. TRENDS could also benefit from recently
revised standard emission factors and updated sources of activity data.
Due to findings in this report as well as other factors, the TRENDS methodology has
been revised as of 1993; thus, references to TRENDS in this report will no longer be valid for
years 1985 and beyond, effective with the 1993 edition of the TRENDS report. The new
TRENDS methodology uses the 1985 NAPAP Emission Inventory as a base. Further changes
will be seen in the TRENDS reports published in 1994 and thereafter. Thus, the reader is
cautioned that comments on the EPA TRENDS report in this document are valid for editions
prior to 1993, but are not valid for the editions for 1993 and thereafter.
x
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SECTION 1
INTRODUCTION
Section 406 of the 1990 Clean Air Act Amendments (CAAA) requires that not later
than January 1, 1995, the Administrator of the Environmental Protection Agency (EPA)
transmit to Congress a report containing an inventory of national annual sulfur dioxide (SO2)
emissions from industrial sources for all years for which data are available, as well as the
likely trend in such emissions over the following twenty-year period.
To support the development of the report to Congress, the Air and Energy Engineering
Research Laboratory (AEERL) conducted an analysis of the differences in the 1985 National
Acid Precipitation Assessment Program (NAPAP) Emission Inventory and the 1985 EPA
TRENDS Emission Estimates for industrial SO2 emission sources. This document presents
the initial findings of this analysis.
The 1985 NAPAP emission inventory is the most comprehensive national inventory of
industrial SO2 emissions that has been compUfd to date. The NAPAP inventory was used by
Congress in the development of the 1990 CAAA. In section 406 of the 1990 CAAA,
Congress cites a limit for industrial SO2 emissions of 5.6 million tons. This value was
derived from the 1985 NAPAP emission inventory.1
The majority of industrial SO2 emissions as reported in the 1985 NAPAP Emission
Inventory are reported as point sources. Over 4,000 industrial facilities were listed as
emitting SO2, one third of these facilities emitted a small amount of SO2 (<100 tons of SO2).
Figure 1 shows that relatively few sources (about 130) account for approximately 50 percent
of the total industrial SO2 emissions. Based on data from the 1985 NAPAP inventory, only
500 facilities account for 80 percent of the industrial SO2 emissions.
Every year the Office of Air Quality Planning and Standards (OAQPS) prepares
annual estimates to determine emission TRENDS.2 The emission estimates are updated as
necessary to account for changes in the activity data or the emission estimation method.
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5,000,000 -
1,000
2,000 3,000
# of plants
4,000
Figure 1. Cumulative sulfur dioxide emissions in the 1985 NAPAP inventory versus
number of plants
Historically, the EPA TRENDS estimates have only included source categories that exceeded
10,000 metric tons of a criteria pollutant.
The calculation of the EPA TRENDS emission estimates is accomplished by following
a documented procedure. The procedure that pertains to industrial SO2 emission source
categories is included as Appendix A. The procedures manual is supplemented with two
extensive spreadsheets that are utilized in the TRENDS calculation procedure. The emissions
calculations spreadsheet includes all of the emission factors, fuel sulfur assumptions, and
control assumptions and is utilized in the calculation of current emissions. The second
spreadsheet contains historic activity data and is used to project emissions for the study year.
Data are entered into the spreadsheets and are used in other areas of the spreadsheet as
necessary. The only documentation of the 1985 TRENDS estimates is the procedures manual
and the accompanying spreadsheets. In several instances, following the documented
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procedures resulted in values that were inconsistent with the values in these spreadsheets.
This occasionally resulted in two sets of 1985 TRENDS SO2 emission estimates, the
published TRENDS value and the calculated TRENDS value. These inconsistencies are
documented throughout this report.
In 1991, a scoping study was undertaken to determine the feasibility of different
approaches for developing an updated industrial SO2 emission estimate for the report to
Congress. This scoping study revealed large differences in the NAPAP and TRENDS
emission estimates. Table 1-1 summarizes the differences between the NAPAP and TRENDS
estimates.
The annual EPA TRENDS estimate is a logical source of industrial SO2 emissions
trends data. Prior to using the EPA TRENDS estimate in the 1995 Report to Congress, a
detailed analysis of the differences that exist in the 1985 NAPAP and TRENDS estimates was
undertaken. The results of that analysis are presented in this report.
This report includes three sections. Section 2 presents the results of the detailed
analysis. Section 3 summarizes the conclusions for each source category covered in the
detailed analysis.
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TABLE 1-1. MAGNITUDE DIFFERENCES BETWEEN 1985 TRENDS
AND NAPAP SO2 EMISSION ESTIMATES
Source Category3
Coal"
Oil0
Natural Gasd
Wood
Miscellaneous Fuel
Other Fuel Combustion Emissions
Reported through NAPAP
1° Copper
1° Lead and Zinc
2° Lead
1° Aluminum
Other Primary and Secondary Metals
Emissions Reported through NAPAP
Iron and Steel
Iron and Steel Foundries
Oil and Natural Gas Production
Pulp and Paper
Cement
Glass
Lime
Sulfuric Acid
Carbon Black
Petroleum Refineries
Other Industrial Process Emissions
Reported through NAPAP
Total
TRENDS
(tons)
1,840,000
540,000
0
10,000
80,000
650,000
240,000
30,000
70,000
360,000
160,000
250,000
620,000
30,000
30,000
210,000
10,000
830,000
5,960,000
NAPAP
(tons)
1,721,000
713,000
33,000
42,000
14,000
74,000
655,000
106,000
21,000
58,000
42,000
204,000
16,000
332,000
130,000
291,000
23,000
32,000
217,000
28,000
640,000
220,000
5,612,000
Delta Delta
(tons) (percent)
119,000
-173,000
-33,000
-32,000
66,000
-74,000
-5,000
134,000
9,000
12,000
-42,000
156,000
-16,000
-172,000
120,000
329,000
7,000
-2,000
-7,000
-18,000
190,000
-220,000
348,000
6.9
-24.3
-100.0
-76.2
471.4
-100.0
-0.8
126.4
42.9
20.7
-100.0
76.5
-100.0
-51.8
92.3
113.1
30.4
-6.3
-3.2
-64.3
29.7
-100.0
6.2
"Except where noted, the emissions for a source category represent process level emissions
only and do not include emissions from the combustion of fuel.
"Excludes bituminous coal and lignite consumed at cement and lime manufacturing facilities
Excludes both distillate and residual oil consumed at cement plants and petroleum refineries
and residual oil consumed at iron and steel mills.
"Excludes natural gas consumed in cement manufacturing, petroleum refining, the iron and
steel industry, glass manufacture, and at crude petroleum and natural gas production
facilities.
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SECTION 2
ANALYSIS OF 1985 TRENDS AND NAPAP ESTIMATES
A detailed analysis of the differences and a determination of the validity of emission
estimates presented by both sources is provided in this section. The analysis of the
differences is limited to the source categories which appear in the TRENDS method. This
section is divided into three subsections: combustion, non-ferrous smelting, and other
industrial categories. Combustion includes coal, oil, natural gas, and miscellaneous fuels from
all industrial processes except the largest fuel-consuming industries (specifically cement
manufacturing, petroleum refining, iron and steel processing, glass manufacturing, and lime
manufacturing). Non-ferrous smelting includes primary copper, primary zinc, primary lead,
primary aluminum, and secondary lead. Other industrial processes include the pulp and paper
industry, chemical manufacturing (sulfuric acid and carbon black production), petroleum
refining, the iron and steel industry, and the minerals processing industries (cement, glass, and
lime manufacturing).
A table summarizing the emission estimates for the source categories is presented at
the beginning of each subsection. The summary table lists the applicable Source
Classification Codes (SCC) and Standard Industrial Classification (SIC) codes for each source
category. In addition, the emissions are broken down to illustrate the differences between the
NAPAP and TRENDS estimate. Except for fuel combustion, these industrial categories are
wholly represented in the stationary point source NAPAP categories.
Each subsection holds to a standard format for comparison of the TRENDS and
NAPAP emission estimates by industrial category. Each of the source category discussions
begins with a comparison of the overall estimate for the subcategory. Following this
comparison, the remaining discussion is divided into six parts:
TRENDS Activity
TRENDS Emission Factor
TRENDS Emissions
NAPAP Activity
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NAPAP Emissions
Conclusion
Within the first three divisions covering TRENDS, the TRENDS estimate is recreated
and discussions of the derivation of the activity data, the emission factor, and the final
emission estimate are provided. Many of the TRENDS emission estimates do not include all
of the emission sources within the source category. For example, there may be three types of
furnaces in a metallurgical operation and the TRENDS method may only provide emissions
estimates from two of the three furnace types.
The next two divisions provide the NAPAP activity and emission estimate for the
corresponding emissions categories. It is important to note that the NAPAP emissions are
reported emissions and have probably been derived using source tests, mass balance and both
AP-42 and State emission factors, along with source-specific control information. Additional
emissions (not included explicitly in TRENDS) for the source category which are included in
NAPAP are discussed. For the above metallurgical example, the NAPAP emission estimate
for the third type of furnace is also listed.
Finally, conclusions on the validity of the estimates are made. The conclusions
section includes a "revised" TRENDS estimate where potential errors or gaps in the TRENDS
method are discovered.
2.1 COMBUSTION SOURCES
The TRENDS combustion categories are separated into coal, oil, natural gas,
miscellaneous fuels, and wood. Coal combustion is developed from two numbers, one for
anthracite coal and one for bituminous and lignite. Oil combustion emissions are calculated
for distillate and residual oil. Miscellaneous fuels include coke, coke oven gas, kerosene, and
liquified petroleum gas (LPG). NAPAP emissions are source emissions derived from a
national fuel balance step which compares published fuel use from several DOE publications
to fuel use reported among point sources. Any fuel unaccounted in point sources is assigned
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to the relevant area source category. Emissions are estimated using standard emission factors
and DOE point source data on fuel sulfur. A summary of the differences in the emission
estimates for these combustion categories is presented in Table 2-1.
2.1.1 Oil Combustion
The 1985 TRENDS emission value for industrial oil combustion was 540,000 tons
SO2. The TRENDS estimate includes residual and distillate oil and excludes oil consumed
from cement plants and petroleum refineries, and residual oil consumed by steel mills. The
emission estimates for these industry-specific uses are included in the specific-industry
estimates.
The 1985 NAPAP value for distillate and residual oil, including external combustion
boilers and in-process fuel use, and excluding cement plants, petroleum refineries, and
residual oil consumed by steel mills, is 107,385 + 605,200 = 712,600 tons SO2.
The apparent difference between the two inventories is 117,600 tons of SO2
(26 percent). Table 2-2 summarizes the fuel consumption and emission estimates for the
1985 TRENDS and NAPAP inventories.
2.1.1.1 Distillate Oil
TRENDS activity
Distillate oil consumption is calculated in the TRENDS method by subtracting the
quantity of distillate oil consumed by cement plants and petroleum refineries from the
"adjusted" quantity of distillate oil sales to industrial and oil companies.
The "adjusted" quantity of distillate oil sales to industrial and oil companies in 1985 is
obtained from Table 13 "Adjusted Sales of Distillate Fuel Oil by End Use in the United
States: 1985-1989" of Fuel Oil and Kerosene Sales3 For 1985, the value is:
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TABLE 2-1. EMISSIONS FROM COMBUSTION TRENDS VERSUS NAPAP
Industrial Combustion
Anthracite
External combustion
In-process fuel
Anthracite (total)
Bituminous
Subbituminous
External combustion
In-process fuel
Lignite
External combustion
In-Process fuel
Bituminous and Lignite (total)'
Coal (total)
Residual Oil
External Combustion
Internal Combustion
In-process fuel use
Residual Oil (totalf
Distillate Oil
External Combustion
Internal Combustion
Space Heaters
In-process fuel
Distillate Oil (total)*
Oil (total)
sec
1-02-001
3-90-001
1-02-002
3-90-002
Area
1-02-003
3-90-003
1-02-004
1-02-014-04
2-02-005-01
Area
3-01-900-12
3-05-900-02
3-90-004
1-02-005
1-02-014-03
2-02-001
Area
1-05-001-05
3-04-900-01
3-90-005f
1985 TRENDS 1985 NAPAP
(tons)' (tons)"
10,998
177
900 77,200
1,272.795
3,137
356,000
78,417
72
1,687,400 1,710,000
1,840,000 1,721,000
349,932
96
242,000
13,132
460,000 67S,226
47,557
727
55,000
578
3,512
72,500 707,400
540,000 712.finn
(continued)
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TABLE 2-1. EMISSIONS FROM COMBUSTION TRENDS VERSUS NAPAP
(Continued)
Industrial Combustion
Natural Gas (Boilers)
External Combustion
Space Heaters
Internal Combustion
In-process fuel
Natural Gas Boilers (total/
Natural Gas Production (total)
sec
1-02-006
1-02-014-01
Area
1-05-001-06
2-02-002
3-01-900-03
3-01-900-13
3-03-900-03
3-04-900-03
3-07-900-03
3-07-900-13
3-90-006
3-99-900-03
3-99-900-13
3-10-900-04
3-10-900-14
Other8
1985 TRENDS 1985 NAPAP
(tons)8 (tons)"
19,085
1,000
11
1,501
11,223
1,400 32,800
400 7,660
Miscellaneous Fuels
Coke
External Combustion
Coke (totalf
Coke-oven Gas
External Combustion
In-process fuel
1-02-008
1-02-007-07
3-90-007-01
3-90-007-02
3-90-007-89
36,000
11,253
77,253
2
2,687
Coke-oven Gas (total)1
Kerosene
Internal Combustion
Kerosene (total)
2-02-009
43,255
2,497
2,659
421
427
(continued)
-------
TABLE 2-1. EMISSIONS FROM COMBUSTION TRENDS VERSUS NAPAP
(Continued)
Industrial Combustion
Liquified Petroleum Gas
External Combustion
Space Heaters
In-process fuel
Liquified Petroleum Gas (total)
Miscellaneous Fuels (total)
Wood
Wood/Bark Waste
In-process fuel
Wood (total)
Other NAPAP Industrial Fuel
Combustion Categories
External Combustion
Process Gas
Bagasse
Solid Waste
Liquid Waste
Internal Combustion
Gasoline and Diesel
In-Process Fuel Use
Process Gas
sec
1-02-010
1-05-001-10
3-90-009-89
3-90-010-89
1-02-009
Area
3-90-008-89
3-90-009-99
1-02-007-02
1-02-007-10
1-02-007-99
1-02-014-02
1-02-011
1-02-012
5-03
Area
1-02-013
2-02-003
2-02-004
3-03-900-24
3-90-007-97
3-90-007-99
3-99-900-24
1985 TRENDS 1985 NAPAP
(tons)" (tons)"
27
18
7
709 52
80,000 14,400
15,141
17,000
9,568
10,000 41,700
44,804
170
2,753
10.686
1,000
12.199
135
1,233
(continued)
10
-------
TABLE 2-1. EMISSIONS FROM COMBUSTION TRENDS VERSUS NAPAP
(Continued)
Industrial Combustion
SCC
1985 TRENDS
(tons)8
1985 NAPAP
(tons)"
Liquid Waste
Miscellaneous Processes
Other NAPAP Industrial Fuel
Combustion Categories
Total
3-90-013
3-99-999
2,470,000
166
717
74,500
2,597,000
' National Air Pollutant Emission Estimates. 1900 -1991, EPA^54/R-92-013, October 1992.
" The 1985 NAPAP Emissions Inventory (version 2): Development of the Annual Data and Modelers' Tapes, EPA-
600/7-89-012a, November 1989.
c Excludes bituminous and lignite burned in cement and lime kilns.
d Excludes residual oil burned in cement plants, petroleum refineries and iron and steel mills.
' Excludes distillate oil burned in cement plants and petroleum refineries.
' Excludes natural gas burned in cement plants, petroleum refineries, iron and steel mills, glass manufacture, and oil
and natural gas production.
1 Other includes all natural gas combustion emissions with an SIC code of 1311 or 1321.
k Excludes iron and steel industry.
' Excludes iron and steel industry.
11
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TABLE 2-2. COMPARISON OF OIL COMBUSTION
VALUES FOR 1985 TRENDS AND NAPAP
Category
Distillate Oil
Emissions (tons)
Fuel Consumed (106 gallons)
Residual Oil
Emissions (tons)
Fuel Consumed (106 gallons)
Total Oil Combustion
Emissions (tons)
Trends
Published
3,426.8
3,562
540,000
Trends
Calculated
72,500
3,429.8
460,000
3,555
532,500
NAPAP
Published
107,400
1,902
605,200
5,615
712,600
2,592,678,000 + 876,505,000 = 3,469,183,000 gallons.
The quantity of oil consumed by cement plants is obtained from Table 7, "Clinker
Produced in the United States, by Fuel" of Minerals Yearbook 1986 "Cement".* The quantity
for 1985 is 755,000 barrels (31,710,000 gallons). TRENDS assumes that one-third of the oil
consumed is distillate oil (10,570,000 gallons).
The quantity of distillate oil consumed by petroleum refineries is obtained from
Table 43, "Fuels Consumed at Refineries by PAD District, 1985" of the Petroleum Supply-
Annual.5 The figure for 1985 is 758,000 barrels (31,836,000 gallons).
Therefore the TRENDS activity number for industrial distillate oil consumption is:
3,469,183,000 - 10,570,000 31,836,000 = 3,426,777,000 gallons.
The value in the current TRENDS activity data file is 3,426,800,000 for 1985.
12
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TRENDS emission factors
The emission factors cited in the TRENDS procedure are for external combustion of
grades 1 and 2 oil (combined) and grade 4 oil. The emission factors listed in the TRENDS
procedure are provided below.
SCC Description Emission Factor Units
1-02-005-01 External Combustion 143.6S lbs/103 gallons
Industrial: Distillate grades 1 burned
and 2 oil
1-02-005-04 External Combustion - 150.0S lbs/103 gallons
Industrial: Distillate grade 4 burned
oil
The 1985 sulfur content for distillate oil is obtained from Table 1 "Summary of
Grade 1 Fuels" and Table 2 "Summary of Grade 2 Fuels" of Heating Oils6 which reports
average sulfur contents for five regions of the country for both grade 1 and 2 oil. This report
does not include an average sulfur content for grade 4 oil due to a lack of data. The average
sulfur content for grade 1 oil ranged from 0.042 to 0.123 weight percent. The average sulfur
content for grade 2 oil ranged from 0.228 to 0.267 weight percent. The average sulfur
contents were averaged across grade and region based on the number of samples, and the
average grades 1 and 2 sulfur content was determined to be 0.206 weight percent. By
contrast, the average sulfur contents reported through NAPAP (weighted on the number of
records reporting fuel sulfur content) are 0.36 for grades 1 and 2 oil and 0.85 for grade 4 oil.
The cement procedure (see Section 2.3.7) cites a distillate oil sulfur content of 0.3 percent.
The TRENDS procedure requires that the emission factors be weighted based on AIRS
data and provides a table to assist in the weighing. Table 2-3 illustrates the values used to
produce a weighted emission factor for distillate oil combustion. Table 2-3 requires the
emission factor for internal combustion engines burning distillate oil. For turbines, the
emission factor is 140.0S lbs/103 gallon burned and for reciprocating engines, the emission
factor is 31.22 lbs/103 gallon burned.7 Table 2-3 also requires activity data obtained from the
1985 NAPAP emission inventory. Average sulfur content for grades 1 and 2 oil are from
13
-------
Heating Oils as derived above and, for the other SCCs, the average NAPAP sulfur contents
were used.
TABLE 2-3. WEIGHTED AVERAGE EMISSION FACTOR
FOR DISTILLATE OIL COMBUSTION
Combustion Category
Boilers burning grade 1 or 2
Boilers burning grade 4
Turbines
Internal Combustion Engines
Weighted Average (lb/103 gal)
NAPAP
Consumption
(103 gallons)
843,851'
125,949"
352b
399
AP-42 S02
Emission Factors
(lb/103 gal)
143.6S
150.0S
140.0S
31.2
42.3
Average sulfur
content
(weight percent)
0.206
0.85
0.27
1 Heating Oils, 1985
" NAPAP
The weighted average emission factor was calculated by multiplying the activity
number (consumption) by the emission factor (and the sulfur content as needed) and dividing
by the total activity. The average emission factor for 1985 was calculated as 42.3 lb/103
gallon. This value is higher than the emission factors that were used in the 1990 (39.2 lb/103
gallon) and the 1991 (38.5 lb/103 gallon) TRENDS estimates.
The TRENDS procedure calls for an SO2 control efficiency, which is obtained from
EIA 767 data. If a control efficiency is applied, the TRENDS value is not documented and
the control efficiency does not appear in the TRENDS spreadsheets. In addition, the EIA-767
data pertains to utility boilers and the suitability of transferring control data from the utility
sector to the industrial sector has not been investigated or documented.
14
-------
TRENDS emissions
The TRENDS emission estimate for distillate oil in 1985 is:
3,426,777 * 42.3 / 2000 = 72,476 tons of SO:.
NAPAP activity
The overall NAPAP activity should match the TRENDS number. During the
development of the NAPAP inventory, the same national industrial distillate oil consumption
value was used to produce a "fuel balance" among point and area sources. In NAPAP, the oil
consumed by point sources [as reported through the National Emissions Data System
(NEDS)] is subtracted from the national number and any remaining balance is allocated to the
area source inventory. As shown in Table 2-1, there are more emissions reported among area
sources than for external combustion point sources. This may be due to the under reporting
of fuel usage by point sources. The reporting of fuel usage was a secondary priority in
NAPAP and many sources consider throughput data confidential and did not report it. In
addition, the entire State of Texas did not report industrial fuel usage by plant, instead fuel
usage was reported at the county level.
The distillate oil activity data reported through NAPAP include external combustion
boilers, space heaters, internal combustion engines, and in-process fuel use. To better
compare the TRENDS and NAPAP combustion estimates, the fuel used in the cement and
petroleum refining industries must be subtracted from the total NAPAP estimate.
Unfortunately, for the NAPAP inventory development effort, fuel usage was not a priority
data element and facilities were not required to report their fuel usage. Therefore, subtracting
the fuel used by these industries as reported in NAPAP will still not provide a reliable value
for comparing the fuel combustion and will in fact make the two estimates more dissimilar.
The emission factors for industrial distillate oil combustion range from 31.2 for
internal combustion reciprocating engines to 143.6S for the majority of the boiler descriptions.
15
-------
In addition, the emission factor for distillate in-process fuel use (general) is 0.0, and it is
intended that this emission factor be used to report fuel usage for industries where the process
emission factor accounts for the fuel sulfur emissions. Both cement and lime kilns have
substantially lower emission factors (98S and 72S respectively), due to the affinity for sulfur
of both lime and cement.
NAPAP emissions
The NAPAP industrial distillate oil emissions are reported as follows:
SCC Description
1-02-005-01 External combustion boilers - Industrial: Distillate
oil, grade 1 and 2
1-02-005-02 External combustion boilers - Industrial: Distillate oil
1-02-005-03 External combustion boilers - Industrial: Distillate oil
1-02-005-04 External combustion boilers - Industrial: Distillate
oil, grade 4
1-02-014-03 External combustion boilers - Industrial: Distillate
oil, cogeneration
1-05-001-05 External combustion boilers - Space heaters,
Industrial, Distillate oil
2-02-001-01 Internal combustion engines - Industrial, Distillate
(Diesel) oil, turbine
2-02-001-02 Internal combustion engines - Industrial, Distillate
(Diesel) oil, reciprocating
2-02-001-03 Internal combustion engines - Industrial, Distillate
(Diesel) oil, turbine cogeneration
3-04-900-01 Secondary metal, Process heaters, distillate oil
3-90-005-01 In process fuel use, Distillate oil
3-90-005-02 In process fuel use - Distillate Oil: Cement kiln/dryer
3-90-005-03 In process fuel use - Distillate Oil: Lime kiln
3-90-005-89 In process fuel use, Distillate oil. General
3-90-005-99 In process fuel use. Distillate oil, General
Total
Tons SO. Emitted
39,359
2,071
800
3,625
3,836
578
284
399
68
8
59
2,404
12
1,624
1.827
56,954
In addition, NAPAP reports area source emissions for distillate oil of 55,000 tons
This results in total NAPAP distillate oil emissions of 111,954 tons of SO,.
16
-------
To compare the NAPAP estimate with the TRENDS estimate, emissions for cement
kilns/dryers and petroleum refineries must be subtracted from this total. For the above listed
SCCs, NAPAP reports that 2,450 tons are emitted from cement manufacturing (SIC 3241) and
2,119 tons are emitted at petroleum refineries (SIC 2911). This results in 107,385 tons of
SO2 being emitted through distillate oil combustion excluding cement manufacturing and
petroleum refineries.
Conclusion
The distillate oil estimates are 72,480 tons for TRENDS versus 107,358 tons for
NAPAP. The NAPAP point source estimate and the TRENDS estimate are quite similar,
although no conclusion can be drawn from this similarity. This may indicate that area source
emissions were overestimated due to an underestimate of fuel use in the point source
inventory.
There is a huge discrepancy in the reported quantity of oil bumed in the TRENDS
estimate versus the NAPAP inventory. TRENDS reports 3,426 x 106 gallons and NAPAP
reports approximately 2,000 x 106 gallons. Table 3 "Total Inputs of Energy for Heat, Power,
and Electricity Generation by Census Region, Industry Group and Selected Industries, 1985"
of Manufacturing Energy Consumption Survey: Consumption of Energy, 1985* reports
31,684,000 barrels (bbls) consumed (1,330.7 x 106 gallons). This survey reports an activity
that is approximately one third the value reported in TRENDS. If the value used in TRENDS
was also used to compute an area source activity in NAPAP, this could have resulted in a
large overestimation in distillate oil consumed and resulting emissions reported in NAPAP
through the area source category.
The development of an average sulfur content for distillate oil is not well documented
in the TRENDS procedure. The sulfur content assumptions have a large impact on the
overall emission factor. Additional effort should be expended to determine a reasonable
average sulfur content, to determine if industrial distillate oil consumers are electing to use
lower sulfur content oil, and if so, the overall effects on emissions from this category.
17
-------
2.1.1.2 Residual Oil
TRENDS activity
The residual oil consumption is calculated by subtracting the quantity of oil consumed
by cement plants, petroleum refineries, and steel mills from the "adjusted" quantity of residual
oil sales to industrial and oil companies.
The adjusted quantity of residual oil sales to industrial and oil companies in 1985 is
obtained from Table 14 "Adjusted Sales of Residual Fuel Oil by End Use in the United
States: 1985-1989" of Fuel Oil and Kerosene Sales 1989? For 1985, the value is:
4,011,361,000 + 776,019,000 = 4,787,380,000 gallons.
The quantity of oil consumed by cement plants is obtained from Table 7 "Clinker
produced in the United States, by fuel" of Minerals Yearbook 1986 "Cement".4 The quantity
for 1985 is 755,000 barrels (31,710,000 gallons). TRENDS assumes that two thirds of the oil
consumed is residual oil (21,140,000 gallons).
The quantity of residual oil consumed by petroleum refineries is obtained from
Table 43 "Fuels Consumed at Refineries by PAD District, 1985" in the Petroleum Supply
Annual5 The figure for 1985 is 13,326,000 barrels (559,692,000 gallons).
The quantity of residual oil consumed by steel mills was calculated by multiplying the
quantity in tons of raw steel produced in 1985 by a conversion factor for the value of residual
oil consumed per ton of raw steel produced. The conversion factor used is 7.38 gal/ton raw
steel. The quantity of raw steel produced is obtained from the Bureau of Economic Analysis,
Survey of Current Business. The quantity of raw steel produced is more readily available
from Table 1 "Salient Iron and Steel Statistics" of Minerals Yearbook 1986 "Iron and Steel."-
The value for 1985, in both references, is 88,259,000 short tons. The quantity of residual oil
consumed by steel mills is calculated as:
18
-------
is:
88,259,000 * 7.38 gal/ton raw steel = 651,350,000 gallons.
Therefore the TRENDS activity value for residual oil consumed by industrial sources
4,787,380 - 21,140 - 559,692 - 651,350 = 3,555,198 x 103 gallons.
The value in the TRENDS activity table is 3,562.300 x 103 gallons.
TRENDS emission factors
The emission factor cited in TRENDS is for grade 6 oil, SCC 1-02-004-01, and the
value is:
158.6S lbs/103 gallons burned.
This emission factor matches the AIRS Facility Subsystem Source Classification Codes
and Emission Factor Listing for Criteria Air Pollutants7 document The average sulfur
content of grade 6 Fuel Oil is obtained from Heating Oils, J985.6 Again, this reference
provides averages for each of five regions. The average sulfur contents range from 1.20 to
1.75 percent in a total of 44 samples. The average national figure based on the number of
samples is 1.63 percent. The average sulfur content for residual oil can also be obtained from
Table 11 "Receipts of No. 6 Fuel Oil at Electric Utilities" of Cost and Quality of Fuels for
Elecmc Utility Plants 1985.9 For 1985, the average sulfur content of grade 6 fuel oil was
1.09 percent by weight. The emission factor for residual oil (based on the Heating Oils,
79S56 data) is:
158.6 * 1.63 = 258.5 lb/103 gallons burned.
19
-------
TRENDS emissions
The emissions are calculated as:
258.5 * 3,555,198 / 2000 = 459,510 tons of SO:.
NAPAP activity
The residual oil activity data reported through NAPAP include external combustion
boilers, space heaters, internal combustion engines, and in-process fuel use. Collection and
quality assurance of all throughput data were not a priority item in the NAPAP inventory.
The NAPAP inventory also includes approximately 932,000 x 106 gallons of crude oil burned
during production in the total residual oil throughput value. This oil was placed in the
residual oil category because no other category existed in NAPAP.
NAPAP emissions
The estimated emissions reported through NAPAP for residual oil combustion are
listed below:
SCC Description Tons SO. Emitted
1-02-004-01 External combustion boilers - Industrial: Residual 349,348
oil, grade 6 oil
1-02-004-02 External combustion boilers - Industrial: Residual 39 304
oil, 10-100 MMBTU/hr
1-02-004-03 External combustion boilers - Industrial- Residual 2 676
oil, <10 MMBTU/hr
1-02-004-04 External combustion boilers - Industrial: Residual 5,836
oil, grade 5
1-02-004-05 External combustion boilers - Industrial: Residual 1 655
oil, Cogeneration
1-02-004-06 External combustion boilers - Industrial: Residual 4
oil
1-02-014-04 External combustion boilers Industrial: CO Boiler, 375
Residual oil
20
-------
SCC Description Tons SO. Emitted
2-02-005-01 Internal combustion engines - Industrial, Residual/ 96
Crude oil, reciprocating
3-01-900-12 Chemical Manufacturing, Incinerators, Residual oil 657
3-05-900-02 Mineral Products, Process Heater, Residual oil 134
3-90-004-02 In-process fuel use. Residual oil Cement Kiln/dryer 3,574
3-90-004-03 In-process fuel use, Residual oil. Lime Kiln 738
3-90-004-89 In-process fuel use. Residual oil. General 19,451
3-90-004-99 In-process fuel use, Residual oil, General 1.644
Total 425,493
In addition, the NAPAP estimate includes 242,000 tons of SO, from the combustion of
residual fuel oil by area sources, bringing the NAPAP total for residual oil combustion to
667,493 tons of SO2.
To compare the NAPAP and TRENDS estimates, it is necessary to exclude the
residual oil emissions from cement manufacturing, petroleum refineries, and steel mills. The
emission estimates for the above listed SCCs are 3,807 tons for cement manufacturing (SIC
3241); 44,208 tons for petroleum refining (SIC 2911); and 14,318 tons for iron and steel mills
and foundries (SIC 3312 and 3325). Subtracting these emissions results in a NAPAP estimate
of 605,160 tons of SO,.
Conclusion
The TRENDS estimate is 459,510 tons for residual oil excluding cement plants,
petroleum refineries and steel mills. The NAPAP estimate for the same category of emissions
is 605,160 tons of SO2. The two estimates would be much closer if the area source
component of the NAPAP total were not included.
There is a huge discrepancy in the reported quantity of residual oil burned in the
TRENDS estimate versus the NAPAP inventory. TRENDS reports 3,555 x 106 gallons and
NAPAP reports approximately 6,000 x 106 gallons. Table 3 "Total Inputs of Energy for Heat.
21
-------
Power, and Electricity Generation by Census Region, Industry Group and Selected Industries,
1985" of Manufacturing Energy Consumption Survey: Consumption of Energy, 1985s reports
80,252,000 bbls consumed (3,370.6 x 106 gallons).
2.1.2 Coal Combustion
The 1985 TRENDS SO: emission value for coal is comprised of two separate
categories; anthracite, and bituminous coal and lignite. The published TRENDS emission
estimate of 1,840,000 tons of SO; excludes emissions from bituminous coal and lignite
consumed at cement and lime manufacturing facilities. The 1985 NAPAP value, excluding
bituminous coal and lignite consumed at cement and lime manufacturing facilities, was
1,721,000 tons of SO2. The apparent difference between the two inventories is 119,000 tons
of SO2 (7 percent). Table 2-4 illustrates the differences in the coal consumption and emission
estimates for the 1985 TRENDS and NAPAP inventories.
TABLE 2-4. COMPARISON OF COAL COMBUSTION
VALUES FOR 1985 TRENDS AND NAPAP
Category
Anthracite
Emissions (tons)
Fuel Consumed (103 tons)
TRENDS
Published
658.8
TRENDS
Calculated
10,900
800
NAPAP
Published
11,000
522
Bituminous & Lignite
Emissions 1,687,000 1,710,000
Fuel Consumed (106 tons) 61.6 62.131 74.535
Total Coal Combustion 1,840,000 1,698,000 1,721,000
Emissions (tons)
The total published TRENDS estimate is 1.84 x 106 tons SO2. In following the
TRENDS procedure, the emission estimates for anthracite as a category and bituminous and
lignite as a category are 10,900 and 1,687,000 tons of S(X respectively. The total of
1,698,000 tons SO: differs from the published TRENDS estimate by 152,000 tons SO,.
22
-------
The sulfur contents and resulting emission factors that were actually used in 1985 are
not documented and may explain the difference. In addition, the TRENDS procedure manual
refers to the use of control assumptions as documented in the EIA-767 data. If control
assumptions have been applied (EIA-767 data pertain to utilities and should not be used to
estimate controls on the industrial sector), they are not documented.
2.1.3 Anthracite Coal
2.1.3.1 1985 TRENDS Activity
Anthracite combustion activity obtained from the distribution of anthracite coal from
District 24 (District 24 is the anthracite-producing district of Pennsylvania) to industrial users
except coke plants. The value for 1985 is obtained from Table 6 "Distribution of U.S. Coal
by Origin, Destination, and Consumer" of Coal Distribution.10 The value for 1985 is
800,000 short tons.
The TRENDS activity data spreadsheet has a 1985 activity value of 658,800 tons. The
wording in the TRENDS procedure document is "obtain the distribution of anthracite from
Pennsylvania to industrial less coke plants." This could be interpreted as direction to subtract
the coke coal (29,000 short tons), but this would be an error (because the coal coke is already
excluded from the value) and it does not resolve the difference between the two values.
2.1.3.2 TRENDS Emission Factors
Emission factors for three types of boilers, pulverized, traveling grate stoker, and
hand-fired, that burn anthracite coal are 39.0S Ibs/ton burned. The TRENDS method assumes
a sulfur content of 0.7 percent. This provides an emission factor of:
39.0 * 0.7 = 27.3 Ib/ton burned.
23
-------
2.1.3.3 TRENDS Emissions
TRENDS emissions were calculated using the activity value found in the TRENDS
spreadsheet
658,800 * 27.3 / 2000 = 8,990 tons of SO.
Emissions calculated using the activity value derived following the TRENDS
procedure manual results in emissions of:
800,000 tons * 27.3 / 2000 = 10,920 tons of S0:.
2.13.4 NAPAP Activity
The NAPAP activity value for anthracite coal combustion is based on the SCC codes
for industrial external combustion and in-process fuel use. However, collection and quality
assurance of all throughput data were not priority items.
2.13.5 NAPAP Emissions
SCC Description Tons SO. Emitted
1-02-001-01 External combustion boilers - Industrial: Anthracite 9,099
coal, Pulverized coal
1-02-001-02 External combustion boilers - Industrial: Anthracite 17
coal
1-02-001-04 External combustion boilers - Industrial: Anthracite 1 872
coal, Traveling grate, (overfeed) stoker
1-02-001-07 External combustion boilers - Industrial: Anthracite 10
coal, Hand-fired
3-90-001-89 In process fuel use, Anthracite coal, General 99
3-90-001-99 In process fuel use, Anthracite coal, General 7g
Total 1U75
24
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2.1.3.6 Conclusion
The emission estimates are in agreement, 11,000 tons of S02 in both NAPAP and
TRENDS. The NAPAP inventory does not report all of the anthracite coal that is consumed,
and it is unclear what fraction of the anthracite coal combustion is represented by the
emissions that are reported through NAPAP. The NAPAP estimates result in an overall
emission factor of 42.8 Ibs/ton of coal burned. This translates into an average sulfur content
of 1.1 percent. The reported sulfur content for anthracite coal varies in the NAPAP
inventory. The average reported for pulverized coal is 1.15 percent (3 records reporting).
The average reported for traveling grate (overfeed) stoker and the majority of records
reporting is 0.7 (24 records). The assumptions on sulfur content have a large influence on the
emission estimate.
The activity value that is published in the TRENDS activity spreadsheet could not be
replicated. The NAPAP inventory may overestimate SO; emissions relative to the reported
quantity of coal burned but anthracite coal is a relatively minor category. Additional research
into a reasonable average sulfur content for anthracite coal is warranted.
2.1.4 Bituminous Coal and Lignite
2.1.4.1 TRENDS Activity
The 1985 TRENDS activity for bituminous coal and lignite is calculated by
subtracting coal consumed in lime and cement plants from the national total for industrial
users. The national value is obtained from Table 23 "Coal Consumption by End-use Sector"
of Quarterly Coal Report.11 The 1985 value for "other industrial" is 75,317,000 tons.
The consumption by cement plants is obtained from Table 7 "Clinker produced in the
United States, by fuel" of Minerals Yearbook 1986 "Cement.1* In 1985, 11,606,000 tons of
coal were consumed by cement plants.
25
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National annual lime production is obtained from "Facts and Figures for the Chemical
Industry" published in Chemical & Engineering News.12 The 1985 primary production
figure was 15,800,000 short tons. Coal consumption is estimated using a multiplier of 0.1 ton
coal/ton lime produced. Therefore, the estimated coal consumption by lime plants is:
15,800,000 * 0.1 = 1,580,000 tons.
The TRENDS bituminous coal and lignite consumption is:
75,317,000 - 11,606,000 - 1,580,000 = 62,131,000 tons.
The TRENDS activity spreadsheet has a value of 61,600,000 tons of coal consumed.
2.1.4.2 TRENDS Emission Factors
The documented procedure for determining an overall emission factor for this category
is complex and the documentation states that the procedure has not been applied. The
primary complexity is in the development of an average sulfur content. The TRENDS
procedure uses an overall emission factor of 38.IS Ib SO2/ton coal burned. In the complex
procedure, an average sulfur content is developed from each coal production district and these
average sulfur contents are weighted based on shipments data listed in Coal Distribution.10
Recent TRENDS procedures for developing an emission factor for this category are
unclear. The emission factor for 1990 was 54.3 Ib/ton burned and the emission factor for
1991 was 51.5 Ib/ton burned. Why and how these factors were changed is unclear. To back
calculate the 1990 sulfur content using the emission factor of 38.IS Ib/ton burned results in
an overall sulfur content of 1.4 percent:
54.3 / 38.1 = 1.4 percent sulfur.
26
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2.1.4.3 TRENDS Emissions
TRENDS emissions, using the 1990 emission factor and the activity value in the
TRENDS spreadsheet, are calculated as follows:
61,600,000 * 54.3 / 2000 = 1,672,440 tons of SO:.
Emissions calculated using the activity data derived following the TRENDS procedure
manual results in emissions of:
62,131,000 * 54.3 / 2000 = 1,686,900 tons of SO2.
2.1.4.4 NAPAP Activity
Activity data were not priority items for collection and quality assurance for the entire
NAPAP inventory. Activity data are not reproduced here by SCC.
2.1.4.5 NAPAP Emissions
The following emission estimates were reported for bituminous coal and lignite
combustion.
SCC Description Tons SO. Emitted
Bituminous:
1-02-002-01 External combustion boilers - Industrial: Bituminous 101.735
coal, Pulverized coal: wet bottom
1-02-002-02 External combustion boilers - Industrial: Bituminous 571.457
coal, Pulverized coal: dry bottom
1-02-002-03 External combustion boilers - Industrial: Bituminous 81.758
coal, Cyclone furnace
1-02-002-04 External combustion boilers - Industrial: Bituminous 330.099
coal, Spreader stoker
1-02-002-05 External combustion boilers - Industrial: Bituminous 102.120
coal, Overfeed stoker
27
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sec
1-02-002-06
1-02-002-10
1-02-002-12
1-02-002-17
1-02-002-19
Subbituminous:
1-02-002-21
1-02-002-22
1-02-002-24
1-02-002-25
Lignite:
1-02-003-01
1-02-003-03
1-02-003-04
1-02-003-06
In-process fuel
use:
3-90-002-01
3-90-002-03
3-90-002-89
3-90-002-99
3-90-003-89
Total
Description
External combustion boilers - Industrial: Bituminous
coal, Underfeed stoker
External combustion boilers - Industrial: Bituminous
coal, Overfeed stoker
External combustion boilers - Industrial: Bituminous
coal, Pulverized coal: Dry bottom (Tangential)
External combustion boilers Industrial: Bituminous
coal, Atmospheric Fluidized bed
External combustion boilers - Industrial: Bituminous
coal, Cogeneration
External combustion
Subbituminous coal,
External combustion
Subbituminous coal,
External combustion
Subbituminous coal,
External combustion
Subbituminous coal,
stoker
boilers - Industrial:
Pulverized coal: wet bottom
boilers - Industrial:
Pulverized coal: dry bottom
boilers - Industrial:
Spreader stoker
boilers - Industrial:
Traveling grate (overfeed)
External combustion boilers - Industrial: Lignite,
Pulverized coal
External combustion boilers - Industrial: Lignite,
Cyclone furnace
External combustion boilers - Industrial: Lignite,
Traveling grate (overfeed) stoker
External combustion boilers - Industrial: Lignite,
Spreader stoker
In process fuel use, Bituminous coal, Cement
kiln/dryer
In process fuel use, Bituminous coal, Lime kiln
In process fuel use, Bituminous coal, General
In process fuel use, Bituminous coal, General
In process fuel use, Lignite, General
SO. Emitted
18,088
1,518
20,286
5,438
12,128
83
8,547
11,195
8,396
45,759
341
29,905
2,412
77,859
6,384
6,828
10,925
72
1,453,333
28
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In addition, NAPAP reports area source emissions of 356,000 tons of SO2 from coal
combustion. This brings the total combustion from bituminous coal, subbituminous coal and
lignite to 1,809,333 tons. In order to compare the NAPAP and TRENDS estimates, emissions
from cement and lime kilns must be excluded from the NAPAP estimate. For the above
listed SCCs, 92,524 tons are for cement manufacturing (SIC 3241) and 6,386 tons are for
lime manufacturing (SIC 3274). The adjusted NAPAP emissions for bituminous and lignite
combustion are 1,710,423 tons of S(X
2.1.4.6 Conclusions
The total estimates for both emissions and coal burned for this category are very close.
The total initial activity value, including coal burned in lime manufacturing and cement
plants, is 75.3 x 106 tons of coal in TRENDS versus 74.5 x 106 tons of coal in NAPAP.
Table 3 "Total Inputs of Energy for Heat, Power, and Electricity Generation by Census
Region, Industry Group and Selected Industries, 1985" of Manufacturing Energy Consumption
Survey: Consumption of Energy, 1985 reports 59.195 x 106 tons of coal burned in the
industrial sector. This activity is consistent with both the TRENDS and NAPAP totals. The
emissions, excluding lime and cement-related emissions, are 1.69 x 106 tons of SO2 versus
1.71 x 106 tons of SO2. Again, the NAPAP inventory relies on a total fuel balance to
determine the area source emissions for this category. For this category, the addition of the
area source emissions brings the NAPAP and TRENDS estimate closer together.
The TRENDS method utilizes a factor of 0.1 tons of coal consumed/ton of lime
produced. This factor should be verified. The Manufacturing Energy Consumption Survey:
Consumption of Energy, 1985* and subsequent available editions do not separate lime from
other mineral products industries. The survey for 1991 is expected to provide additional
resolution and the preliminary numbers should be available in late summer of 1993.
The three types of coal that constitute this category each have a slightly different
emission factor. The emission factors for external combustion in industrial boilers are
generally as follows.
29
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Bituminous 1-02-002-01,19 39.0S
Subbituminous 1-02-002-21,29 35.0S
Lignite 1-02-003 30.0S
There are smaller emission factors for some types of bituminous coal combustion (for
example fluidized bed), but these constitute a very small amount of the coal combustion
activity.
Sulfur contents reported in the NAPAP inventory for these SCCs range as follows.
1-02-002-01,19 1.0 to 1.9 percent
1-02-002-21,29 0.4 to 1.5 percent
1-02-003 0.5 to 0.9 percent
Average sulfur contents for the types of coal are estimated based on emissions, and
reported coal consumption are as follows.
1-02-002-01,19 1.4 percent
1-02-002-21,29 0.7 percent
1-02-003 0.7 percent
Use of these sulfur contents results in the following average emission factors.
Bituminous 1-02-002-01,19 54.6 Ib/ton burned
Subbituminous 1-02-002-21,29 24.5 Ib/ton burned
Lignite 1-02-003 21.0 Ib/ton burned
The TRENDS emission factor of 54.3 is probably an overestimation. In addition
there are probably some emission controls that are not reflected in the TRENDS method
30
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2.1.5 Natural Gas
The 1985 TRENDS does not publish emission estimates for categories if the total
estimated emissions are less than 10,000 tons. The emissions from natural gas combustion
are adjusted to exclude natural gas consumed by cement plants, petroleum refineries, the iron
and steel industry, glass manufacturing, and crude petroleum and natural gas production.
Once the TRENDS estimates are adjusted to exclude the above mentioned categories, the
emission estimate is less than 10,000 tons and therefore there is no published SO2 estimate for
natural gas combustion. The adjusted NAPAP emissions are 32,800 tons S02.
The TRENDS procedure includes a subsection adjustment to estimate the emissions
from natural gas combustion during crude petroleum and natural gas production. The
combustion emissions estimated in this section are combined with sulfur recovery emissions
(estimated in Section 2.3.3) and reported in Section 2.3.5. Table 2-5 summarizes the
information for natural gas combustion and natural gas plants and pipelines for the 1985
TRENDS and NAPAP inventories.
TABLE 2-5. COMPARISON OF NATURAL GAS
VALUES FOR 1985 TRENDS AND NAPAP
Category
Natural Gas Combustion
Emissions (tons)
Fuel Consumed (109 ft3)
Natural Gas Plants and
Pipelines
Emissions (tons)
Fuel Consumed (109 ft3)
Trends
Published
4,764.8
1,469.8
Trends
Recreated
1,400
4,852.3
400
1,469.8
NAPAP
Published
32,800
6,700
7,660
15
31
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2.1.5.1 TRENDS Activity
TRENDS separates the natural gas emissions into combustion in boilers and emissions
from gas pipelines and plants. The emissions from the combustion of natural gas at natural
gas pipelines and plants are reported in Section 2.3.5.
Boilers
The total industrial consumption of natural gas consumed in industrial boilers is
obtained from Table 26 "Natural Gas Consumption in the U.S. 1930-1985" of Natural Gas
Annual, 79S5.13 For 1985, this value is 5,901,288 million cubic feet (106 ft3). The
TRENDS procedure subtracts consumption by cements plants, petroleum refineries, the iron
and steel industry, and the glass manufacture industry from the total.
Natural gas consumption for cement plants is provided in Table 7 "Clinker produced
in the United States, by fuel" of Minerals Yearbook 1986 "Cement."* The value for 1985 is
10,644.314 106ft3.
The total natural gas consumption by petroleum refineries is obtained from Table 43
"Fuels Consumed at Refineries" of Petroleum Supply Annual 1985.5 The 1985 value is listed
as 487,830 106 ft3.
Natural gas consumption by the iron and steel industry is estimated from the annual
production of raw steel and a conversion factor of 4.25 x 106 ft3/103 ton raw steel produced.
Annual raw steel production is obtained from Table 1 "Salient Iron and Steel Statistics" of
Minerals Yearbook 1986 "Iron and Steel."* The 1985 production was 88,259,000 tons
Therefore natural gas consumption for the iron and steel industry is calculated as:
4.25 * 88,259 = 375,100 x 106 ft3.
32
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Natural gas consumption by the glass manufacture industry is also estimated using the
annual glass production and a conversion factor of 10.8 x 106 ftVlO3 tons glass produced.
Annual glass consumption is computed as the sum of production of flat glass, container glass,
and miscellaneous glass products. The procedure for calculating annual glass production is
described in Section 2.3.8. Rat glass production in 1985 was obtained from Table 1A
"Summary of Flat Glass Production, Shipments, and Inventories: 1986 and 1985" of Current
Industrial Reports Flat Glass Summary for 1986.u Container glass production was obtained
from Table 5 "Shipments, Production and Stocks of Glass Containers: 1985" from Current
Industrial Reports Glass Containers Summary for 1986.15 Miscellaneous glass products are
assumed to be an additional 10 percent of the production of flat glass and glass containers.
Annual glass production in 1985 was 16,245,837 tons. Therefore, the amount of natural gas
consumed by the glass manufacture industry for 1985 is:
10.8 * 16,246 = 175,457 x 106 ft3.
The resulting TRENDS consumption in boilers is calculated as:
5,901,288 - 10,644 - 487,830 - 375,100 - 175,457 = 4,852,257 x 106 ft3.
The value reported in the TRENDS activity spreadsheet is 4,764,800 x 106 ft3.
Gas pipelines and plants
The natural gas consumption for gas pipelines and plants is the sum of pipelines fuel
and lease and plant fuel. These values are obtained from Table 13 "Consumption of Natural
Gas" of Natural Gas Annual, 1985.13 The value for 1985 for lease and plant fuel is 966,047
x 106 ft3 and the 1985 value for pipelines fuel is 503,766 x 106 ft3. Therefore, the total
pipelines and plants natural gas combustion rate is:
966,047 + 503,766 = 1,469,813 x 106 ft3.
33
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2.1.5.2 TRENDS Emission Factor
The TRENDS emissions factor is 0.6 Ib SO2/106 ft3 burned. This emission factor is
consistent with all of the natural gas combustion emission factors listed in AIRS Facility
Subsystem Source Classification Codes and Emission Factor Listing for Criteria Air
Pollutants1
2.1.5.3 TRENDS Emissions
TRENDS emissions for industrial boilers using the activity rate in the TRENDS
spreadsheet are:
0.6 * 4,764,800 / 2000 = 1,429 tons of SO2.
TRENDS emissions for natural gas pipelines are calculated as:
0.6 * 1,469,813 / 2000 = 441 tons of SO2.
Because TRENDS does not report emissions of fewer than 10,000 tons from a source
category, the published TRENDS estimate is zero tons for 1985.
2.1.5.4 NAPAP Activity
Boilers
Activity data collection and quality assurance were not priority items for all sources
Activity data for natural gas combustion in boilers are not itemized here.
34
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Natural gas production
The TRENDS activity for natural gas production is the amount burned during the
development of the natural gas (extraction, transportation, etc.). In NAPAP, the following
two SCCs appear to correspond to the combustion of natural gas in natural gas production as
reported through TRENDS.
SCC Description 106 ft3 Burned
3-10-004-04 Oil and Gas Production Process Heaters: Natural 12,187
gas
3-10-004-14 Oil and Gas Production Steam generators: Natural 2.852
gas
Total 15,039
Additional combustion of natural gas at natural gas pipelines and plants is reported
through boilers, engines, as in-process fuel, and in flares.
2.1.5.5 NAPAP Emissions
Industrial natural gas consumption is listed for external combustion boilers, process
heaters, internal combustion boilers, and in-process fuel. The emissions at the 8-digit SCC
level are as follows.
Boilers
SCC
1-02-006-01
1-02-006-02
1-02-006-03
1-02-006-04
1-02-014-01
Description
External combustion boilers -
gas, Over 100 MMBtu/Hr
External combustion boilers -
gas, 10-100 MMBtu/Hr
External combustion boilers -
10 MMBtu/Hr
External combustion boilers -
gas, Cogeneration
External combustion boilers -
Industrial: Natural
Industrial: Natural
Industrial: Less than
Industrial: Natural
Industrial: CO Boiler,
Tons SO^ Emitted
23,655
10,733
267
315
9
Natural gas
35
-------
SCC Description Tnns SO, Emitted
1-05-001-06 External combustion boilers - Space heaters - 14
Industrial, Natural gas
2-02-002-01 Internal combustion engines- Industrial: Natural gas, 1,523
Turbine
2-02-002-02 Internal combustion engines- Industrial: Natural gas, 4,198
Reciprocating
2-02-002-03 Internal combustion engines-Industrial: Natural gas, 211
Turbine: Cogeneration
2-02-002-04 Internal combustion engines- Industrial: Natural gas, 4
Reciprocating: Cogeneration
3-01-900-03 Chemical manufacturing - Process heaters: Natural 1.908
gas
3-01-900-13 Chemical manufacturing Incinerators: Natural gas 2.016
3-03-900-03 Primary metal production Process heaters: Natural 1,370
gas
3-04-900-03 Secondary metal production - Process heaters: 25
Natural gas
3-07-900-03 Pulp & Paper and Wood products - Process heaters: 39
Natural gas
3-07-900-13 Pulp & Paper and Wood products - Incinerators: 13
Natural gas
3-90-006-02 In process fuel use: Natural gas, Cement kiln/dryer 0
3-90-006-03 In process fuel use: Natural gas, Lime kiln 0
3-90-006-05 In process fuel use: Natural gas, Metal melting 0
3-90-006-89 In process fuel use: Natural gas, general 12,700
3-90-006-99 In process fuel use: Natural gas, general 993
3-99-900-03 Miscellaneous Manufacturing Industries - Process 3
heaters: Natural gas
3-99-900-13 Miscellaneous Manufacturing Industries - 37
Incinerators: Natural gas
Tota] 60.033
In addition, NAPAP reports area source emissions of 1,000 tons of SO-, from natural
gas combustion. This brings the total combustion from natural gas to 61,033 tons of SO, In
order to compare the NAPAP and TRENDS estimates, emissions from cement plants,
petroleum refineries, the iron and steel industry, and the glass manufacture industry must be
excluded from the NAPAP estimate. For the above listed SCCs, 5 tons are from cement
manufacturing (SIC 3241), 9,377 tons are from petroleum refineries (SIC 2911), 10,044 tons
36
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are from the iron and steel industry (SIC 3312, & 3325), and 1,582 tons are from glass
manufacture (SIC 3211, 3221, & 3229). In addition, NAPAP reports 6,797 tons of S02 from
combustion during crude petroleum and natural gas production (SIC 1311) and 404 tons of
SO2 from natural gas liquids production (SIC 1321) for the above listed SCCs. The adjusted
NAPAP emissions for natural gas combustion in boilers are 32,824 tons of SO2.
Natural gas pipelines and plants
Emissions from combustion of natural gas at natural gas pipelines and plants are
reported in NAPAP under as follow.
SCC Description Tons SO- Emitted
3-10-004-04 Oil and Gas Production - Process heaters: Natural 442
gas
3-10-004-14 Oil and Gas Production - Steam generators: Natural 18
gas
Total 460
In addition, emissions of 6,797 tons of S02 from crude petroleum and natural gas
(SIC 1311) and 404 tons of SO2 from natural gas liquids production (SIC 1321) are included
in the category Natural Gas Pipelines and Plants. This brings the total for this category to
7,661 tons of SO2.
2.1.5.6 Conclusions
The activity rates for natural gas combustion that are reported in the NAPAP inventory
are not consistent with the emissions. The emissions appear to be overestimated by less than
an order of magnitude and, given the relatively small amount of SO2 emitted, were not closely
reviewed in the NAPAP inventory. The total natural gas reportedly consumed is about 7,000
x 109 ft3 in NAPAP versus 5,901 x 109 ft3 in TRENDS (unadjusted). The TRENDS value is
fairly consistent with the 4,512 x 109 ft3 reported through the Manufacturing Energy
Consumption Survey: Consumption of Energy, 1985*
37
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The TRENDS conversion factors for both the iron and steel industry and the glass
manufacturing industry are to be periodically updated. The value for the steel industry that is
currently used is 4.25 x 106 ft3 of natural gas/103 tons of raw steel. The value for the iron
and steel industry can be updated with information provided in Table 3 "Total Inputs of
Energy for Heat, Power, and Electricity Generation by Census Region, Industry Group, and
Selected Industries, 1985" of Manufacturing Energy Consumption Survey: Consumption of
Energy, 79SS.16 Natural gas consumed by blast furnaces and steel mills was 400 billion
cubic feet (TRENDS calculated 375 billion cubic feet for raw steel). Based on a 1985 raw
steel production of 88,259,000, a revised factor for iron and steel would be:
400,000 / 88,259 = 4.53 x 106 ft3/!000 ton raw steel.
The value for glass cannot be recalculated at this time because the reference cited
combines stone, clay, and glass products.
2.1.6 Miscellaneous Fuel
TRENDS includes industrial SO2 emission estimates for four categories of fuel. The
estimate is published for all four of the fuels combined. The TRENDS estimate for
miscellaneous fuels is 80,000 tons of SO2. NAPAP reports emissions of 14,400 tons of SO:
for those same four fuels. The apparent difference in the emission estimates is 65,600 tons
(455 percent). Table 2-6 compares the NAPAP and TRENDS values for these four fuels.
2.1.6.1 TRENDS Activity
In TRENDS, there are four subcategories for miscellaneous fuel SO, emissions: coke,
coke oven gas, kerosene, and LPG. Both the coke and coke oven gas categories exclude fuel
burned in the iron and steel industry. Each of these subcategories is discussed separately
below.
38
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TABLE 2-6. COMPARISON OF MISCELLANEOUS FUELS
VALUES FOR 1985 TRENDS AND NAPAP
Category
Coke Combustion
Emissions (tons)
Fuel Consumed (103 tons)
Coke oven Gas Combustion
Emissions (tons)
Fuel Consumed (109 ft3)
Kerosene Combustion
Emissions (tons)
Fuel Consumed (106 gallons)
LPG Combustion
Emissions (tons)
Fuel Consumed (106 gallons)
Total Miscellaneous Fuels
Emissions (tons)
TRENDS
Published
36,000
1,343
43,000
79
2,000
463
0
1,979
80,000
TRENDS
Calculated
26,645
1,621.2
1,075
85
1,434
463
63
5,756
29,200
NAPAP
Published
11,000
1,656
2,700
4
421
0.656a
52
286b
14,400
'Excludes activity assigned to area sources as part of distillate oil.
"Excludes activity assigned to area sources as natural gas equivalents.
Coke
Industrial coke consumption outside the iron and steel industry is an adjusted sum of
coke from coal and petroleum coke. Coke from coal is obtained from Table A5 "Coke and
Breeze Production at Coke Plants" of the Quarterly Coal Report.11 Total breeze production at
coke plants in 1985 was 2,155,000 short tons. TRENDS assumes that 24 percent is sold for
use as boiler fuel. Therefore, industrial breeze consumption is:
2,155,000 * 0.24 = 517,200 short tons.
39
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Coke sales to "other industrial plants" are obtained from Table A6 "Coke and Breeze
Distributed from Coke Plants" in the Quarterly Coal Report.11 The 1985 value was 873,000
short tons. Therefore, total industrial coke, produced from coal, consumed outside the iron
and steel industry in 1985 was:
517,200 + 873,000 = 1,390,200 short tons.
TRENDS provides two sources for petroleum coke. The first reference is Table 12
"Receipts of Petroleum Coke at Electric Utilities for Steam Plants of 50-Megawatt Installed
Nameplate Capacity or Larger, 1985" of Cost and Quality of Fuels for Electric Utility Plants
19859 which lists 279,900 short tons of petroleum coke received at electric utilities. The
second reference is a footnote to Table 7 "Consumption of Coal, Petroleum, and Gas by
Electric Utilities, 1984-1985" of the Electric Power Annual 1985" which states that
petroleum coke consumption in 1985 was 231,000 short tons by the electric utility industry.
The total coke consumed is calculated by adding the total amount of coke produced
from coal, and the amount of petroleum coke consumed by power plants. For 1985, the total
is:
1,390,200 + 231,000 = 1,621,200 short tons.
This value differs from the value in the TRENDS activity spreadsheet which was
1,343,000 short tons. It is unclear why the petroleum coke consumed at electric utilities
should be included in the industrial fuel combustion category. Assuming this is an error in
the TRENDS procedure document would bring the values closer together (1,390,000 short
tons here versus 1,343,000 short tons in activity spreadsheet).
Coke oven gas
The TRENDS procedure is to obtain coke oven gas production from Quarterly Coal
Report" however, coke oven gas production is not provided in that report. Table 23 "Coal
Consumption by End-Use Sector" of Quarterly Coal Report" provides coal consumption bv
40
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coke plants in 1985 of 41,056,000 short tons. Figure 15 "Production of Coke and Coal
Chemicals" of Coal Data: A Reference1* indicates that 11,000 ft3 of coke oven gas are
produced per ton of metallurgical (coking) coal. This is consistent with the value used in the
Iron and Steel section of the TRENDS procedure. This results in 1985 coke oven gas
production of:
41,056,000 * 11,000 / 1,000,000 = 451,616 x 106 ft3.
The TRENDS method assumes that 18.8 percent of the coke oven gas is consumed
outside of the iron and steel industry. Therefore the coke oven gas consumption is:
451,616 * 0.188 = 84,903 x 106 ft3.
The value in the TRENDS activity spreadsheet is 79,300.x 106 ft3.
Kerosene
Kerosene consumption is obtained from Table 15 "Adjusted Sales of Kerosene by End
Use in the United States 1985-1989" of Fuel Oil and Kerosene Sales J989.3 The 1985 value
is 254,491,000 gallons for industrial use and 208,139,000 for all other. Therefore the
TRENDS activity value for industrial kerosene is:
254,491,000 + 208,139,000 = 462,630,000 gallons.
LPG
Most (88 percent) of the LPG is used as a feed stock. The TRENDS procedure
attempts to account for this using an ad hoc procedure to determine consumption for use as a
fuel. LPG consumption by industrial sources is calculated by multiplying the 1985 production
with the ratio of 1982 sales of LPG to the 1982 product supplied (the last available data).
41
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In 1982 the total sales were 5,397,000,000 gallons. The 1982 products supplied were
1,499,000 barrels/day. Therefore the ratio is:
5,397,000,000 / 1,499,000 = 3,600 gallons/bbl/day.
The 1985 product supplied is obtained from Table S7 "Liquified Petroleum Gases
Supply and Disposition" of Petroleum Supply Annual 1985 5 In 1985 the products supplied
were 1,599,000 barrels/day, therefore, the 1985 industrial LPG activity figure is:
1,599,000 * 3,600 = 5,756,000,000 gallons.
The value listed in the TRENDS activity spreadsheet is 1,979 x 106 gallons. Table 3
"Total Inputs of Energy for Heat, Power, and Electricity Generation by Census Region,
Industry Group, and Selected Industries, 1985" of the Manufacturing Energy Consumption
Survey: Consumption of Energy, 1985 lists the industrial LPG consumption as 1,116 x 106
gallons.
2.1.6.2 TRENDS Emission Factors
Coke
The TRENDS method recommends the development of a weighted emission factor for
coal coke and petroleum coke. The emission factor listed for petroleum coke is 38.8 and
TRENDS multiplies this value by 3.25 percent sulfur content for petroleum coke. There is no
emission factor in the AIRS Facility Subsystem SCC and Emission Factor Listing for Criteria
Pollutants1 or in Compilation of Air Pollutant Emission Factors. Volume I: Stationary Point
and Area Sources. Fourth Edition. AP-4219 for combustion of petroleum coke.
The TRENDS procedure document lists an emission factor of 30.3 Ib/ton burned for
coal coke. The emission factor listed in the AJRS Facility Subsystem SCC and Emission
42
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Factor Listing for Criteria Pollutants' for industrial coke combustion is 39.0S Ib/ton burned
(SCC 1-02-008-02). This implies that TRENDS is using 0.77 percent sulfur for coal coke.
The TRENDS procedure requires that the emission factors be weighted based on AIRS
data and provides a table to assist in the weighing. Table 2-7 illustrates the values used to
produce the weighted emission factor of 43.9 Ibs/ton coke burned. The TRENDS spreadsheet
lists an emission factor of 53 Ib/ton for both the 1990 and 1991 study years.
TABLE 2-7. WEIGHTED AVERAGE EMISSION FACTOR
FOR COKE COMBUSTION
Coke Type
Petroleum Coke
Coal Coke'*
Weighted Average
(lb/103 ton burned)
Trends Activity SOX Emission Factor
(103 tons) " (Ib/ton)
231 126*
1,390.2 30.3
43.9
* Assumes a constant sulfur content value of 3.25 percent for petroleum coke.
** Total of breeze production plus coke industrial boilers.
Coke oven gas
The emission factor for coke oven gas is 680.0S Ib SO^IO6 ft3. This is consistent with
the AIRS Facility Subsystem SCC and Emission Factor Listing for Criteria Pollutants7
document for SCC 1-02-007-007. The TRENDS procedure document assumes a sulfur
content of 1.605 percent. Therefore the emission factor is:
680.0 * 1.605 = 1,091 Ib SO2/106 ft3.
43
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Kerosene
TRENDS lists the kerosene emission factor for SCC 1-02-005-01 as 143.6S Ibs
SO2/103 gallons burned. TRENDS also lists an average sulfur content of 0.075 percent for
kerosene. This results in an overall emission factor for kerosene combustion of:
143.6 * 0.075 = 10.77 lb/103 gallons burned.
The SCC 1-02-005-01 is for grades 1 and 2 distillate oil. An appropriate SCC for
kerosene would be 2-02-009-01. All of the emission factors listed in AIRS Facility Subsystem
SCC and Emission Factor Listing for Criteria Pollutants1 for SO, from kerosene combustion
are 6.2 lb/103 gallons burned.
LPG
TRENDS lists the LPG emission factor for SCC 1-02-010-02 as 86.5S Ibs SCyiO3
gallons burned. This matches the emission factor in the AIRS Facility Subsystem SCC and
Emission Factor Listing for Criteria Pollutants1 for both butane and propane. TRENDS also
lists an average sulfur content of 0.0013 percent for LPG and results in the following overall
emission factor:
86.5 * 0.0013 = 0.11 lb/103 gallons burned.
2.1.6.3 TRENDS Emissions
The estimates presented below utilize the activity rates found in the TRENDS activity
spreadsheet and emission factors found in the TRENDS procedure document Differences
between these numbers and TRENDS estimates are discussed under conclusions.
44
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Coke
Emissions from industrial coke combustion are calculated using the activity value and
emission factor found in the TRENDS spreadsheets.
1,343,000 * 53.0 / 2000 = 35,589 tons of SO:
Coke oven gas
Emissions are calculated using the activity value found in the TRENDS activity
spreadsheet
79,300 * 1,091 / 2000 = 43,258 tons of SO:
Kerosene
Emissions are calculated using the emission factor listed in the TRENDS procedure
document
462,600 * 10.77 / 2000 = 2,491 tons of SO,
LPG
Emissions are calculated using the activity value found in the TRENDS activity
spreadsheet.
1,979,000 * 0.11 / 2000 = 109 tons of SO2
Total miscellaneous fuels
The total emissions are the sum of coke, coke oven gas, kerosene and LPG:
35,589 + 43,258 + 2,491 + 109 = 81,447 tons S0;
45
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2.1.6.4 NAPAP Activity
Although these data were not priority NAPAP items, the data are presented here for
comparison.
Coke
The NAPAP activity for coke combustion include industrial external boilers and in-
process fuel use. The NAPAP inventory reports 55 percent of the activity in SIC codes 1011,
3312 and 3321 (all iron and steel). The remainder includes petroleum refining, electric
utilities, chemical manufacturing and mineral products.
SCC Description Tons burned
1-02-008-02 External combustion boilers - Industrial: Coke, all boiler sizes 392,652
1-02-008-04 External combustion boilers Industrial: Coke, cogeneration 834,218
3-90-008-99 In process fuel use, Coke, general 2.414.424
Total 3,641,294
Coke oven gas
The NAPAP activity for coke oven gas include external combustion boilers and in-
process fuel use. The inventory reports 99 percent of the activity in SIC codes 1011, 3312
and 3321, with the remainder in chemical manufacturing, carbon black and petroleum
refining.
SCC Description 106 ft3 Burned
1-02-007-07 External combustion boilers - Industrial: Process 111,686
gas, coke oven gas
3-90-007-01 In process fuel use, Process gas. Coke oven or blast 423,091
furnace
3-90-007-02 In process fuel use, Process gas. Coke oven gas 193,971
3-90-007-89 In process fuel use, Process gas, Coke oven gas 65 119
Total 793,867
46
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Kerosene
The NAPAP activity for kerosene include internal combustion boilers. No adjustment
for area source activity could be made because kerosene is combined into the distillate oil
category.
SCC
2-02-009-01
Total
LPG
Description
Internal combustion engines Industrial:
Kerosene/Naphtha (Jet fuel), Turbine
10' Gallons Burned
656
656
The NAPAP activity for LPG include external combustion boilers, space heat, internal
combustion boilers, and in-process fuel use. No adjustment for area source activity could be
made because LPG is combined as natural gas equivalents in the natural gas category.
SCC
1-02-010-01
1-02-010-02
1-05-001-10
2-02-010-01
2-02-010-02
3-90-009-89
3-90-010-89
3-90-010-99
Total
Tons burned.
Description
External combustion boilers - Industrial: LPG -
Butane
External combustion boilers - Industrial: LPG -
Propane
External combustion boilers - Space heaters:
Industrial - LPG
Internal combustion engines - Industrial: LPG,
propane: reciprocating
Internal combustion engines - Industrial: LPG,
butane: reciprocating
In process fuel use, LPG, general
In process fuel use, LPG, general
In process fuel use, LPG, general
103 Gallons
Bumed
714
100,060
47
1,854
91,944'
9.702
81.864
286,188
47
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2.1.6.5 NAPAP Emissions
Coke
The NAPAP emission estimates for coke combustion include industrial external boilers
and in-process fuel use.
SCC Description Tons SO. Emitted
1-02-008-02 External combustion boilers Industrial: Coke, all 2.246
boiler sizes
1-02-008-04 External combustion boilers - Industrial: Coke, 9,665
cogeneration
3-90-008-99 In process fuel use. Coke, general 89
Total 12,000
The NAPAP inventory reports 747 tons SO2 in these three SCCs among SICs 1011,
3312 and 3321 within the iron and steel industry. The remaining 11,252 tons are categorized
with miscellaneous fuel.
Coke oven gas
The NAPAP emission estimates for coke oven gas include external combustion boilers
and in-process fuel use.
SCC Description Tons SO. Emitted
1-02-007-07 External combustion boilers Industrial: Process 17,637
gas, coke oven gas
3-90-007-01 In-process fuel use, Process gas, Coke oven or blast 6
furnace
3-90-007-02 In-process fuel use, Process gas, Coke oven gas 4,331
3-90-007-89 In-process fuel use, Process gas, Coke oven gas 4.795
Total 26,770
48
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The NAPAP inventory reports 24,081 tons SO2 in these SCCs among SICs 1011, 3312
and 3321 (iron and steel). The remaining 2,689 tons are categorized within miscellaneous
fuel.
Kerosene
The NAPAP emission estimates for kerosene include internal combustion boilers.
SCC Description Tons SO. Emitted
2-02-009-01 Internal combustion engines - Industrial: 421
Kerosene/Naphtha (Jet fuel), Turbine
Total 421
LPG
The NAPAP emission estimates for LPG include external combustion boilers, space
heat, internal combustion boilers, and in-process fuel use.
SCC Description Tons SO, Emitted
1-02-010-01 External combustion boilers - Industrial: LPG - 0
Butane
1-02-010-02 External combustion boilers - Industrial: LPG 27
Propane
1-05-001-10 External combustion boilers - Space heaters: 18
Industrial - LPG
2-02-010-01 Internal combustion engines - Industrial: LPG, 0
propane: reciprocating
2-02-010-02 Internal combustion engines - Industrial: LPG, 0
butane: reciprocating
3-90-009-89 In process fuel use, LPG, general 2
3-90-010-89 In process fuel use, LPG, general 5
3-90-010-99 In process fuel use, LPG, general _0
Total 52
49
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2.1.6.6 Conclusions
There are many numbers in this category that are not well justified in the TRENDS
method. The categories are discussed separately.
Coke
The coke emissions, excluding iron and steel, are 11,300 tons in NAPAP, and 36.000
tons in TRENDS. The coke emissions are probably underestimated in the NAPAP inventory.
There are discrepancies in the TRENDS activity data. First, it is unclear why the
petroleum coke that is delivered to electric utilities should be included in this category. (The
NAPAP total for this petroleum coke is 3,111 tons.) Second, the activity value in the
TRENDS spreadsheet could not be reproduced by following the TRENDS procedure.
TRENDS lists 1,343,000 tons in the activity spreadsheet. Following the TRENDS procedure
resulted in a value of 1,621,000 tons. The Manufacturing Energy Consumption Survey:
Consumption of Energy, 1985* lists 1,952,000 tons of coke and breeze for industries outside
of blast furnaces and steel mills. Therefore, the activity value used to estimate the 1985 coke
combustion emissions is probably too low in the TRENDS procedure.
The emission factor which is used for coke combustion may overestimate the
TRENDS emission estimate. TRENDS uses an emission factor of 53.0 Ib/ton burned. The
AIRS Facility Subsystem SCC and Emission Factor Listing for Criteria Pollutants1 has an
emission factor of 39.OS Ib/ton burned. The NAPAP inventory lists an average coke sulfur
content of 0.7 percent which results in an overall emission factor of 27.3 Ib/ton burned. If
the petroleum coke delivered to electric utilities is not included and the value from the
Manufacturing Energy Consumption Survey: Consumption of Energy, 1985* is used and the
revised emission factor is utilized, the following TRENDS coke emission estimate would
result.
1,952,000 * 27.3 / 2000 = 26,645 tons of SO:
50
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Coke oven gas
The coke oven gas emissions, excluding iron and steel, are 2,700 tons in NAPAP, and
43,000 tons in TRENDS. It appears as though TRENDS overestimates SO2 emissions for
combustion of coke oven gas outside the iron and steel industry. TRENDS assumes 18.8
percent of the coke oven gas produced is burned in boilers outside the iron and steel industry.
The 18.8 percent is not documented. In addition, the TRENDS iron and steel section assumes
that 40 percent of coke oven gas is used in the iron and steel process equipment (see Roll and
Finish subsection of iron and steel). The remaining 40 percent of the coke oven gas being
consumed in the TRENDS procedure is not accounted for. Table 12 "Production and
Disposal of Coke Oven Gas in the United States by Producing State: 1980" of Coke and Coal
Chemicals in 79S020 reports that in 1980 coke gas use was 39 percent by producers in
heating ovens, 58 percent other use by producers, 1.4 percent commercial sales, and 1.5
percent wasted. These statistics are consistent with the NAPAP distribution of coke oven gas
combustion.
TRENDS lists a coke oven gas average sulfur value of 1.605 percent. The NAPAP
inventory lists an average sulfur content for coke oven gas of 0.5 percent. Using a factor of
1.4 percent of coke oven gas burned in industrial boilers outside the iron and steel industry
and using the NAPAP average sulfur content, results in the following emissions.
451,616 * 0.014 * 680 * 0.5 / 2000 = 1,075 tons of SO2
Kerosene
The kerosene emissions are 421 tons in NAPAP and 2,491 tons in TRENDS. The
kerosene emissions are probably overestimated in the TRENDS document. The emission
factor used in the TRENDS procedure to estimate kerosene emissions is actually an emission
51
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factor for distillate oil. The emission factor cited is 10.77 lb/103 gallon burned. Using a
kerosene emission factor of 6.2 lb/103 gallons burned results in the following emissions.
462,630 * 6.2 / 2000 = 1,434 tons of SO2
LPG
The LPG emissions are 52 tons in NAPAP and 109 tons in TRENDS. The LPG
emissions are probably overestimated in the TRENDS document. Following the TRENDS
procedure manual did not result in the same activity value for LPG combustion as is
published in the TRENDS activity spreadsheet. The LPG activity value used in the 1985
TRENDS estimate is higher (1,979 million gallons versus 1,116 million gallons) than the
value reported through the Manufacturing Energy Consumption Survey: Consumption of
Energy, J985.s Using the value reported through the survey results in the following
emissions.
1,116,000 * 86.5 * 0.0013 / 2000 = 63 tons of SO,
The TRENDS procedure for determining LPG combustion activity is difficult to
understand. A preferred approach may be to hold the value constant and update it every three
years with a new Manufacturing Energy Consumption Survey.
Total TRENDS emissions for the miscellaneous fuel category would then be:
26,645 + 1,075 + 1,434 + 63 = 29,217 tons of SO:
2.1.7 Wood
The published TRENDS emission estimate for wood combustion is 10,000 tons of
SO2. The NAPAP estimate is 41,700 tons of SO2. The apparent difference in the emission
estimates is 31,700 tons (76 percent).
52
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2.1.7.1 TRENDS Activity
The TRENDS procedure for determining the activity value for wood combustion is
poorly documented and difficult to follow. The total industrial combustion of wood for both
the 1984 and the 1989 study years is available from Table 1 "U.S. Consumption of Wood
Energy by Sector, 1949-1990" of Estimates of U.S. Biofuels Consumption 1990.21 The value
for 1984 is 1,679 trillion Btu. The TRENDS procedure document provides a conversion
factor of 17.2 million Btu per oven-dried short ton. Therefore the 1984 wood consumption is:
(1,679 x 1012) / (17.2 x 106) = 97.616 x 106 oven-dried short tons.
The TRENDS procedure initially instructs the user to obtain the consumption figures,
in tons, for the previous year and to assume that 15 percent of the heating value is lost to
moisture on a typical basis. The TRENDS procedure further states that as of 1990, wood
consumption was published in therms of Btu's and an average Btu content per oven-dried
short ton is provided. TRENDS then states "No adjustment to the calculated tonnage is
necessary." This last statement is interpreted as instruction not to apply the 85 percent factor
to account for lost moisture.
TRENDS assumes that 75 percent of the industrial wood is consumed by the pulp and
paper industry and 25 percent is used in lumber and wood products. TRENDS requires that
the converted (from Btu to oven-dried ton) consumption figure be projected to the update year
following a procedure, outlined in the LPG section, for paper and wood separately. Therefore
the portion of the industrial wood combustion from pulp is:
0.75 * 97,616,300 = 73,212,000 oven-dried tons.
The portion of the industrial wood combustion from the lumber industry is:
0.25 * 97,616,300 = 24,404.000 oven-dried tons.
53
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The production of sulfite (kraft) and sulfite is found in Table 4 "Production and
Shipments of Woodpulp, by Type of Pulp: 1986 and 1985" of Current Industrial Reports,
Pulp, Paper, and Board.22 The 1985 production figure for sulfate was 42,563,831 short tons
and for sulfite was 1,620,084 short tons. Therefore, the total 1985 pulp production value was
44,183,915 short tons. The 1984 value is obtained from the TRENDS activity spreadsheet
and was 42,758,800 short tons. Therefore the projection for the paper portion of the wood
combustion is as follows:
'85 woodpaper = '84 woodpaper * [1 + ('85 paper - '84 paper) / '84 paper]
= 73,212,000 * [1 + (44,183.9 - 42,758.8)7 42,758.8]
= 75,652,388 oven-dried tons
The lumber production is found in Table 1 "Lumber Production: 1980 to 1991" of
Current Industrial Reports, Lumber Production and Mill Stocks.23 The 1985 total production
was 36,445 million board feet. The 1984 total production, as documented in the TRENDS
activity spreadsheet, was 37,065 million board feet Therefore the projection for the lumber
portion of the wood combustion is as follows:
'85 woodlumber = '84 woodlumbCT * [1 + ('85 lumber '84 lumber) / '84 lumber]
= 24,404,000 * [1 + (36,445 37,065)/ 37,065]
= 23,995,795 oven-dried tons
Total industrial wood combustion is the sum of these two figures:
75,652,388 + 23,995,795 = 99,648,183 oven-dried tons.
The value in the TRENDS activity spreadsheet is 113,380,000 oven-dried tons.
54
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2.1.7.2 TRENDS Emission Factors
TRENDS lists the emission factor for wood combustion as 0.15 Ib/ton burned. This is
consistent with the AIRS Facility Subsystem Source Classification Codes and Emission Factor
Listing for Criteria Air Pollutants1 document which lists the emission factors for industrial
external combustion of wood as 0.15 Ib/ton burned for all types of boilers.
2.1.7.3 TRENDS Emissions
Using the activity value in the TRENDS activity spreadsheet results in emissions of:
113,380,000 * 0.15 / 2000 = 8,504 tons of SO2.
2.1.7.4 NAPAP Activity
Collection and quality assurance of the activity data were not priority elements for all
sources in the inventory. The data are not presented here.
2.1.7.5 NAPAP Emissions
The emissions from wood combustion reported in NAPAP include wood and bark
waste burned in external boilers, wood burned as in-process fuel, and area source wood
combustion. Because the collection and quality assurance of the activity data were not high
priority items for all sources, these data are not presented here.
SCC Description Tons SO, Emitted
1-02-009-01 External combustion boilers - Industrial: Wood/Bark 6,863
waste, Bark-fired boiler (>50,000 Ib steam)
1-02-009-02 External combustion boilers - Industrial: Wood/Bark 5,664
waste, Wood/Bark-fired boiler (>50,000 Ib steam)
1-02-009-03 External combustion boilers - Industrial: Wood/Bark 1,102
waste, Wood-fired boiler (>50,000 Ib steam)
1-02-009-04 External combustion boilers - Industrial: Wood/Bark 4
waste, Bark-fired boiler (<50,000 Ib steam)
55
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SCC Description Tons SO. Emitted
1-02-009-05 External combustion boilers - Industrial: Wood/Bark 45
waste, Wood/B ark-fired boiler (<50,000 Ib steam)
1-02-009-06 External combustion boilers - Industrial: Wood/Bark 16
waste, Wood-fired boiler (<50,000 Ib steam)
1-02-009-07 External combustion boilers Industrial: Wood/Bark 1,446
waste, Wood cogeneration
3-90-008-89 In process fuel. Wood, general 9,567
3-90-009-99 In process fuel. Wood, general 1_
Total 24,708
In addition, NAPAP reports 17,000 tons as area source emissions. Therefore, the total
NAPAP wood combustion emission estimate is 41,700 tons SO2.
2.1.7.6 Conclusions
The TRENDS emission estimate for wood combustion is 8,504 tons of SO2. The
NAPAP estimate is 41,700 tons of SO2. Nearly half of the point source emissions in the
NAPAP inventory are from a general in-process wood combustion category. The emission
factor for this SCC (3-90-008-89) is 38.0S Ibs/ton burned. NAPAP also reports an average
sulfur content of 1.5 percent for the SCC. This emission factor is substantially higher than
the emission factor used in TRENDS and the rest of the NAPAP categories (0.15 Ib/ton
burned). As a result, this category is responsible for a disproportionate share of the wood
combustion point source emissions reported in NAPAP. Due to the high emissions for this
one category of wood combustion, the NAPAP inventory probably overestimates the wood
combustion emissions.
Following the TRENDS procedure did not recreate the activity value that was used in
the calculation of the 1985 emission estimate for wood combustion. Even when rounding the
emission estimate to the nearest 10,000 tons, the difference is not insubstantial. Table 3
"Industrial Woodfuel Consumption by Sector, 1990" of Estimates of U.S. Biofuels
Consumption 199CP states that paper and allied product consume 79 percent of the industrial
wood fuel, lumber and wood products consume 18 percent and other industries consume the
56
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remaining 3 percent. Using these breakdowns by industry results in a 1985 wood
consumption value of 99,892,644 oven-dried tons. This results in emissions of:
99,892,644 * 0.15 / 2000 = 7,492 tons of SO2.
2.1.8 Other NAPAP Combustion Categories
Additional emissions are reported in the NAPAP inventory as combustion emissions
for sources not discussed in this section (because they have no corresponding TRENDS
estimate). These emissions include liquid waste, waste oil, solid waste, bagasse, and process
gas, and amount to an additional 74,477 tons of SO,.
2.2 NON-FERROUS SMELTING
The TRENDS nonferrous smelting category includes primary copper, primary lead,
primary zinc, primary aluminum and secondary lead. Additional categories are included in
TRENDS for other criteria pollutants (especially particulate) and other non-ferrous smelting
categories are included in the NAPAP inventory. Table 2-8 presents the comparison of the
NAPAP and TRENDS non-ferrous smelting SO2 emission estimates.
The non-ferrous smelting source categories contribute significantly to the industrial
SO2 emissions. The majority of the smelters recover sulfur that is emitted from the ores
being processed. Due to the increasing environmental pressures exerted on smelters and
global competition, smelters in this country are continuing to close, dramatically affecting the
trends in emissions from these categories. This discussion begins with the reporting of sulfur
recovered as H:SO4 from non-ferrous smelters.
Byproduct 1985 sulfuric acid production was reported in Table 7 "Byproduct Sulfuric
Acid Produced in the United States" of Minerals Yearbook 1989 "Sulfur" and in Table 22
"Byproduct Sulfuric Acid (100% Basis) Produced in the United States" of Minerals Yearbook
1989 "Copper". Values are converted to SO, based on molecular weights of sulfur (32), SO:
57
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TABLE 2-8. COMPARISON OF NON-FERROUS SMELTING
VALUES FOR 1985 TRENDS AND NAPAP
Category (SIC)
Primary Copper (3331)
Emissions (tons)
Activity
Primary Zinc (3339)
Emissions (tons)
103 Tons of concentrate
Primary Lead (3339)
Emissions (tons)
Lead processing (103 tons)
Primary Aluminum (3334)
Emissions (tons)
Aluminum produced (103 tons)
Secondary Lead (3341, 3364)
Emissions (tons)
Reverberatory furnace (103 tons)
Blast furnace (103 tons)
Total Emissions (tons)
TRENDS
Published
650,000
67,400'
686.2
34,500'
759.3
70,000
3,850
30,000
394.0
391.3
990,000"
TRENDS
Calculated
93,864
734.3
98,775
975.4
71,039
3,855.6
27,147
393.6
430.4
940,825
NAPAP
Published
655,300
7.600
98,800
58,400
20,700
216.6
332.8
840,800
"Published together as one value of 240,000 tons of SO2. The discrepancy between the
total and individual sum (67,400 + 34,500) could not be resolved.
""Includes 240,000 tons of SO2 for primary lead and zinc.
(64), and sulfuric acid (98). Table 2-9 lists the 1985 sulfur recovery breakdown/
The TRENDS activity spreadsheet lists sulfur recovered as H:SO4 as 327,900 tons of
SO2 for primary lead and zinc versus 501,000 tons published in Mineral Yearbook, 79S94
2.2.1 Primary Copper
NAPAP and TRENDS report essentially identical SO2 emissions for this category
(655,000 tons vs. 650,000 tons). Because these smelters are large and few in number, it is
understood that TRENDS actually tracks individual primary copper smelter emissions, as does
NAPAP No further analysis of the category is warranted.
58
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TABLE 2-9. RECOVERY OF SULFUR AS H2S04
Copper
Lead &
Molybdenum
Zinc
Total
As Sulfur"
(metric tons)
729,000
87,000
141.000
957,000
As SO2a
(short tons)
1,604,000
191,400
310.200
2,105,600 .
As H2SO4b
(metric tons)
2,230,257
267,159
430.946
2,928,362
As SO2b
(short tons)
1,602,240
191,930
309.600
2.103,770
"Reported in Table 7 Minerals Yearbook 1989 "Sulfur."
"Reported in Table 22 Minerals Yearbook 1989 "Copper."
2.2.2 Combined Primary Lead and Primary Zinc
The 1985 TRENDS value is 240,000 tons SO; for primary lead and zinc, which are
reported together as one category. As described below, this total could not be reproduced.
The 1985 NAPAP value is 98,775 for primary lead and 7,642 for primary zinc. The
discrepancy between the two inventories is 133,600 tons (126 percent).
2.2.3 Primary Zinc
2.2.3.1 TRENDS Activity
National zinc production is obtained from Table 1 "Salient Zinc Statistics" of Minerals
Yearbook 1989 "Zinc."* The 1985 total slab U.S. zinc production was 333,772 metric tons
(367,149 short tons). This value is multiplied by 2 because there are 2 units of concentrate
per ton slab zinc. This provides a value of 734,298 tons of concentrate.
The value listed in the TRENDS activity spreadsheet is 686,200 tons for 1985.
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2.23.2 TRENDS Emission Factor
The emission factor for zinc roasting cited in the TRENDS method is as follows.
SCC Description Emission Units
Factor
3-03-030-02 Primary Metal Zinc Production: 1,100 Ib/ton concentrated
Multiple hearth roaster ore processed
2.2.3.3 TRENDS Emissions
TRENDS accounts for the recovery of sulfur at primary zinc smelters. The 1985
recovery as shown in Table 2-9 is 310,000 tons of S(X Therefore, 1985 emissions are
calculated as follows (using the activity value found in the TRENDS spreadsheet):
1,100 * 686,200 / 2000 - 310,000 = 67,410 tons of SO2.
In contrast, the 1985 emissions using the zinc activity published in Minerals Yearbook4
are:
1,100 * 734,298 / 2000 - 310,000 = 93,864 tons of SO2.
2.2.3.4 NAPAP Activity
The NAPAP activity is listed below. The units for most processing with associated
SO2 emissions are tons of concentrated ore processed. Recall that these activity data were not
high priority for all sources in the inventory.
SCC Description Tons of
Concentrated Ore
Processed
3-03-030-02 Primary Metal Zinc Production: Multiple hearth 35 Q82
roaster
3-03-030-03 Primary Metal Zinc Production: Sinter strand 472 550
60
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SCC Description Tons of
Concentrated Ore
Processed
3-03-030-05 Primary Metal - Zinc Production: Vertical retort/ 1,954,037
electrothermal furnace
3-03-030-06 Primary Metal - Zinc Production: Electrolytic 3,407.830
processor
3-03-030-07 Primary Metal Zinc Production: Rash roaster 0
3-03-030-11 Primary Metal Zinc Production: Zinc casting 79,410'
3-03-030-14 Primary Metal - Zinc Production: Crushing/ 2,376
screening
3-03-030-15 Primary Metal Zinc Production: Zinc melting 26,208"
3-03-030-99 Primary Metal Zinc Production: Not classified 5,682,107
a Tons zinc produced
b Tons processed
As shown above, one record lists 79,410 tons of zinc cast (3-03-030-11), however, it
is doubtful that this represents all of the zinc produced in 1985. The largest value for
concentrated ore processed is 3,407,830 tons. Neither the total zinc cast nor the concentrated
ore processed in the electrolytic processor are consistent with the TRENDS activity value.
2.2.3.5 NAPAP Emissions
SCC Description Tons SO. Emitted
3-03-030-02 Primary Metal - Zinc Production: Multiple hearth 849
roaster
3-03-030-03 Primary Metal - Zinc Production: Sinter strand 5,175
3-03-030-05 Primary Metal - Zinc Production: Vertical retort/ 1,104
electrothermal furnace
3-03-030-06 Primary Metal - Zinc Production: Electrolytic 0
processor
3-03-030-07 Primary Metal - Zinc Production: Flash roaster 258
3-03-030-11 Primary Metal - Zinc Production: Zinc casting 0
3-03-030-14 Primary Metal - Zinc Production: Crushing/ 0
screening
3-03-030-15 Primary Metal - Zinc Production: Zinc melting 0
3-03-030-99 Primary Metal - Zinc Production: Not classified 256
61
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SCC Description Tons SO. Emitted
Total 7.642
Only 849 tons are reported in NAPAP for zinc roasting in the multiple hearth roaster
and this process is not the largest source of SO2 emissions in the NAPAP inventory (although
it does have the largest emission factor).
2.2.3.6 Conclusion
The NAPAP and TRENDS estimates for emissions from primary zinc production are
very different. NAPAP reported emissions of 7,642 tons of SO: and the TRENDS method
resulted in an emission estimate of 93,864 tons of S0:.
The TRENDS published estimate for primary zinc production is combined with the
primary lead estimate and the published total of 240,000 tons of SO2 from both industries
could not be recreated. In the TRENDS method, sulfur recovered as H2SO4 is used in the
development of both the zinc and lead emission estimate. The value in the TRENDS
spreadsheet for recovered sulfur for this section also could not be reproduced. The TRENDS
activity spreadsheet stated that 327,900 tons of SO2 were produced at primary lead and
primary zinc facilities in 1985. The references for these data are sections in the Minerals
Yearbook4 and the values published are 501,500 tons of SO:. The difference in the recovered
sulfur could account for the inability to recreate the published TRENDS value.
The TRENDS method needs to be updated. TRENDS assumes all roasting is done in
a multiple hearth roaster; two additional SCCs for roasting exist, flash roaster (3-03-030-07)
and fluid bed roaster (3-03-030-08). Both have a smaller emission factor (404.4 and 223.5
Ibs/ton of concentrated ore processed, respectively) than the multiple hearth roaster (1,100
Ibs/ton of concentrated ore processed).
The NAPAP inventory did not report the majority of emissions through the multiple
hearth roaster. The NAPAP inventory may have overestimated SO: emissions from some of
62
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the other processes in zinc production (specifically the sinter strand and the vertical
retort/electrothermal furnace SCC 3-03-030-03/05). The discrepancy in NAPAP where the
majority of emissions were not reported through the roasting process needs to be investigated.
but could be an artifact of the NEDS software as well as misreporting of emissions.
2.2.4 Primary Lead
2.2.4.1 TRENDS Activity
The TRENDS procedure has a complicated method to determine "Lead Processing" as
opposed to primary lead production. Primary lead production can be obtained from Table 1
"Salient Lead Statistics" of Minerals Yearbook 1989 "Lead."* The 1985 production value is
the sum from domestic ore and base bullion and from foreign ores and base bullion and was:
422,650 + 71,353 = 494,003 metric tons = 543,403 short tons.
According to the TRENDS procedure manual, lead processing is calculated in four
steps. First, total copper and zinc SO2 emissions are calculated. Second, byproduct sulfuric
acid recovered from copper, zinc, and lead smelters is estimated. Third, total SO; lead
emissions are calculated using the following equation:
Total SO: = SO2 (lead+zinc) - SO2(zinc) + AFS Lead Emissions.
Fourth, the lead processing value is backcalculated using the following equation.
Lead Processing = Total SO. Lead Emissions * 2000
595
The derivation and reasoning behind this procedure are not documented. In addition.
this procedure includes steps to calculate values that are not used in the remaining steps.
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Following the TRENDS procedure for determining lead production leads to the following
value for 1985.
Step 1, copper and zinc SO2 emissions (based on the previous sections) are:
650,000 + 67,410 = 717,410 tons of SO2.
Step 2, byproduct sulfuric acid for copper, lead and zinc are listed in Table 2-9 as 2,100,000
tons of SO2. Byproduct sulfuric acid for lead and zinc are 501,600 tons of SO:. (It is unclear
why the TRENDS procedure references the sulfur recovered from copper smelting).
Step 3, NAPAP lists the 1985 SO2 emissions (SCC 3-03-010-XX) as 98,775 short tons.
Total SO2 = SO2 (lead+zinc) - SO2(zinc) + AFS Lead Emissions
= 501,600 - 310,200 + 98,775 = 290,175 tons of SO2
Step 4,
Lead Processing = 290.175 * 2000 = 975,378 short tons
595
The TRENDS spreadsheet lists a lead processing value for 1985 as 759,300 tons. There is
probably an error in the TRENDS procedure manual. It is unclear why the lead sulfur recoverv
would be added to the zinc sulfur recovery only to subtract the zinc value. The copper sulfur
recovery value is referenced, but does not appear to enter into the equation.
2.2.4.2 TRENDS Emission Factor
The emission factors cited in the TRENDS method are as follows.
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SCC Description Emission Units
Factor
3-03-010-01 Primary Metals - Lead production: 550 Ib/ton lead produced
Sintering, single stream
3-03-010-02 Primary Metals - Lead Production: 45 Ib/ton lead produced
Blast furnace operation
Total 595 Ib/ton lead produced
These emission factors are twice those listed in the AIRS Facility Subsystem Source
Classification Codes and Emission Factor Listing for Criteria Air Pollutants1 document but are
consistent with AP-42. The units are different: AP-42 units are tons of lead produced, the SCC
emission factor units are tons of concentrated ore processed. In addition, the SCC emission factor
document lists 3-03-010-06 as a major source (sintering dual stream versus single stream above) but
this appears to be a new SCC as there are no values in the NAPAP inventory.
2.2.4.3 TRENDS Emissions
Using the TRENDS emission factor and activity rate published in the TRENDS spreadsheet
and subtracting the recovered sulfur results in the following emissions.
759,300 * 595 / 2000 - 191,400 = 34,500 tons of SO2.
Using the activity data derived following the TRENDS procedure manual and subtracting the
recovered sulfur results in emissions of:
975,382 * 595 / 2000 - 191,400 = 98,775 tons of SO:.
2.2.4.4 NAPAP Activity
The following activity data were published in the NAPAP inventory.
65
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SCC Description Tons of
Concentrated Ore
Processed
3-03-010-01 Primary metal - Lead production: Sintering single stream 1,062,662
3-03-010-02 Primary metal Lead production: Blast furnace operation 1,006,182
3-03-010-09 Primary metal - Lead production: Lead dressing 275.599
3-03-010-23 Primary metal Lead production: Lead casting 131.601
2.2.4.5 NAPAP Emissions
There are 21 SCCs or processes listed for lead production. Of these 21 SCCs only four have
associated SO2 emissions and they are listed below.
SCC Description Tons SO. Emitted
3-03-010-01 Primary metal - Lead production: Sintering single 78,496
stream
3-03-010-02 Primary metal Lead production: Blast furnace 20,109
operation
3-03-010-09 Primary metal - Lead production: Lead dressing 1
3-03-010-23 Primary metal - Lead production: Lead casting 169
Total 98,775
2.2.4.6 Conclusion
The NAPAP and TRENDS estimates for emissions from primary lead production are also
very different. NAPAP reported emissions of 98,775 tons of SO2 and the TRENDS method resulted
in an emission estimate of 34,500 tons of S02. (The TRENDS published estimate for primary lead
production is combined with the primary zinc estimate and the published total of 240,000 tons of
SO2 from both industries could not be recreated.)
In the TRENDS method, sulfur recovered as H2S
-------
Minerals Yearbook4 and the values published are 501,500 tons of S02. The difference in the
recovered sulfur could account for the inability to recreate the published TRENDS value for primary
lead and primary zinc emissions.
The TRENDS method is outdated relative to the data that are currently provided in the
Minerals Yearbook, 1989* It is unclear why such a complicated procedure is introduced to
determine lead processing activity. The TRENDS method includes four steps to determine lead
processing, however, many of the steps do not seem logical. After following the four steps, the
result was a lead processing value of 975,378 short tons, which did not match the value of 759.300
tons in the TRENDS activity spreadsheet. After analyzing the four steps that currently comprise the
TRENDS emission estimation procedure for primary lead, it appears that the final number is a simple
sum of the emissions reported through NEDS (now AFS) and the sulfur recovered as sulfuric acid.
The recovered sulfur is then subtracted from the emission estimate. Therefore, there should be
complete agreement between NAPAP and TRENDS for this category. If the TRENDS method is
intended to be different from the simple sum, there are errors in the TRENDS procedure manual that
need to be addressed.
The NAPAP activity for this category is fairly close to the activity published in the Minerals
Yearbook.* The Minerals Yearbook cites a 1985 production of 543,403 short tons. TRENDS
includes the assumption that there is a 2:1 ratio of concentrated ore processed to lead produced.
NAPAP reports 1,006,182 tons of concentrated ore processed in the blast furnace which would
correspond to a lead production rate of 503,000 tons of lead.
2.2.5 Primary Aluminum
The 1985 TRENDS emission value is 70,000 tons of S02 for primary aluminum. The 1985
NAPAP value is 58,400 tons of SO2 for primary aluminum. The discrepancy between the two
inventories is 11,600 tons (20 percent).
67
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2.2.5.1 TRENDS Activity
In TRENDS, the primary aluminum production is obtained from Table 20 "Salient Aluminum
Statistics" of Minerals Yearbook 1989 "Bauxite, Alumina, and Aluminum."4 In 1985 the U.S primary
production was reported as 3,500,000 metric tons (3,850,000 short tons). The TRENDS activity
spreadsheet reports 3,855,600 tons of aluminum produced.
2.2.5.2 TRENDS Emission Factor
SO2 emissions are calculated using an emission factor of 33.5 Ibs/metric ton (reported in the
TRENDS spreadsheet). This factor converts to 36.85 Ibs/ton. The emission factor is documented as
an average emission factor based on NEDS data from Washington State (February 1980).
2.2.5.3 TRENDS Emission Estimate
Emissions using TRENDS method and activity data confirm the reported TRENDS estimate:
36.85 * 3,855,600 / 2,000 = 71,039 tons SO2.
2.2.5.4 NAPAP Activity
NAPAP activity data were not a high priority for collection or quality assurance for all
sources. The activity data reported through the NAPAP inventory are as follows for comparison.
SCC Description Tons of Molten
Aluminum
Produced
3-03-001-01 Primary metal - Aluminum Ore: Electro-Reduction: 2 996007
Prebaked reduction cell
3-03-001-02 Primary metal - Aluminum Ore: Electro-Reduction: 307 880
Horizontal stud soderberg cell (MSS)
3-03-001-03 Primary metal Aluminum Ore: Electro-Reduction- 575 497
Vertical stud soderberg cell (VSS)
3-03-001-04 Primary metal Aluminum Ore: Electro-Reduction-
Materials handling '
68
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SCC Description
3-03-001-05 Primary metal - Aluminum Ore: Electro-Reduction:
Anode baking furnace
3-03-001-06 Primary metal - Aluminum Ore: Electro-Reduction:
Degassing
3-03-001-07 Primary metal - Aluminum Ore: Electro-Reduction:
Roof vents
3-03-001-99 Primary metal Aluminum Ore: Electro-Reduction:
Other not classified
3-03-002-01 Primary metal - Aluminum Hydroxide Calcining:
Overall process
Tons of Alumina Produced
Tons of Molten
Aluminum
Produced
1,950,248
290,785
677,601
7,861.822
4,893,410a
2.2.5.5 NAPAP Emissions
The emissions from primary aluminum production reported through the NAPAP inventory are
as follows.
SCC Description
3-03-001-01 Primary metal - Aluminum Ore: Electro-Reduction:
Prebaked reduction cell
3-03-001-02 Primary metal - Aluminum Ore: Electro-Reduction:
Horizontal stud soderberg cell
3-03-001-03 Primary metal - Aluminum Ore: Electro-Reduction:
Vertical stud soderberg cell
3-03-001-04 Primary metal - Aluminum Ore: Electro-Reduction:
Materials handling
3-03-001-05 Primary metal - Aluminum Ore: Electro-Reduction:
Anode baking furnace
3-03-001-07 Primary metal - Aluminum Ore: Electro-Reduction:
Roof vents
3-03-001-99 Primary metal - Aluminum Ore: Electro-Reduction:
Other not classified
3-03-002-01 Primary metal - Aluminum Hydroxide Calcing:
Overall process
Total
Tons SO. Emitted
31,178
1,976
4,909
3,448
3,230
741
750
12.154
58,386
69
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2.2.5.6 Conclusion
The validity of the TRENDS emission factor for primary aluminum could not be confirmed
and appears suspect for two reasons. First, it relies on one set of old emissions (not test) data.
Second, there is no documentation of an adjustment due to controls. There are three emission factors
in the AIRS Facility Subsystem Source Classification Codes and Emission Factor Listing for Criteria
Air Pollutants1 document. Prebake (3-03-001-01) has an emission factor of 57.3 Ibs/ton, HSS (3-03-
001-02) has an emission factor of 10.0 Ibs/ton, and VSS (3-03-001-03) has an emission factor of 17.0
Ibs/ton. (None of these emission factors was derived from AP-42. In fact, AP-42 does suggest a
method for calculating SCX emissions based on other process parameters, but reports no emission
factor.) Many of the particulate controls on primary aluminum would be effective controls for S02.
An investigation into the distribution of the three types of electro-reduction processes and their
controls and how they dominate the primary aluminum industry should be undertaken to develop an
appropriately weighted emission factor.
Further, the emission factor used by TRENDS is not consistent with the TRENDS indicators
for industrial processes for the primary metals industry production process breakdown (as listed in
the TRENDS procedure document as provided in Appendix A).
Prebake: 71.0 percent of production
HSS: 18.5 percent of production
VSS: 10.5 percent of production
AP-42 confirms that Prebake is the most common.19 However, this is not the weighing used in the
SO: emission factor for primary aluminum. Using this weighing would provide an emission factor
of:
57.3(0.71) + 10.0(0.105) + 17.0(0.105) = 43.5 Ibs/ton.
Using the 43.5 Ibs/ton of aluminum produced emission factor results in a total emission
estimate of 84,000 tons of SO2, exceeding the current TRENDS estimate by 14,000 tons. (Other
70
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weightings used in TRENDS for the emission categories other than primary aluminum may also be
suspect)
The NAPAP reported production for materials handling 3-03-001-04 (which should in theory
represent the sum of the three process types) is 5,371,185 tons of molten aluminum produced.
However, this SCC represents paniculate emissions and no priority was placed on collecting or
quality assuring particulate data under the 1985 NAPAP effort. This materials handling value does
exceed the sum of the three aluminum processes listed above (3,879,384 short tons of aluminum
processed). Note that the sum of the three NAPAP aluminum process SCCs approximates the
production reported in Minerals Yearbook4 (3,850,000 short tons of aluminum).
Using the 1985 NAPAP production estimates would result in a breakdown between the three
process types as follows:
Prebake: 77.2 percent of production
HSS: 7.9 percent of production
VSS: 14.8 percent of production
Using this weighing instead of the TRENDS weighing would result in an even larger emission factor:
57.3C772) + 10.0(.079) + 17.0(.148) = 47.5 Ibs/ton.
If the 1985 NAPAP primary aluminum emission estimate is used to develop a revised
emission factor, an overall factor of 38,063 tons SO2 / 3,850,000 short tons Al = 19.8 Ibs/ton Al
produced. The absolute factor is lower because reported NAPAP emissions from these processes is
only 38,063 tons, but presumably accounts for the effect of SO2 controls.
In the NAPAP inventory, only 38,063 tons of SO: are attributable to the three processes
covered by the TRENDS method. Of the processes that are not included in TRENDS, aluminum
hydroxide calcining is the most important. TRENDS includes the aluminum hydroxide calcining
process in the estimation of TSP and PM-10 emissions but not in the SO2 estimate.
71
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2.2.6 Secondary Lead
The published 1985 TRENDS value is 30,000 tons SO2 from secondary lead processing. The
1985 NAPAP value is 20,720 for secondary lead. The discrepancy between the two inventories is
9,300 tons (45 percent).
2.2.6.1 TRENDS Activity
In TRENDS, the secondary lead production'is obtained from Table 1 "Salient Lead Statistics"
of Minerals Yearbook, 1989 "Lead."* The 1985 production of secondary1 lead (based on lead content)
was 615,695 metric tons (677,264 short tons). The consumption of lead scrap is obtained from
Table 8 "Stocks and Consumption of New and Old Lead Scrap in the United States, by Type of
Scrap" of Minerals Yearbook, 1986 "Lead."4 The total 1985 consumption of scrap is 804,832 metric
tons (885,315 short tons). SO2 emissions are only calculated for reverberatory and blast furnaces.
There are no emission estimates or emission factors for SO2 from pot furnaces.
For reverberatory furnaces the TRENDS activity is the fraction of lead recovered as soft lead
to total lead recovered multiplied by the consumption of scrap. The amount recovered as soft lead is
obtained from Table 11 "Lead Recovered from Scrap Processed in The United States, by Kind of
Scrap and Form of Recovery" of Minerals Yearbook, 1986 "Lead"4 and the value was 273,698 metric
tons (301,068 short tons). The 1985 production from reverberatory furnaces is calculated as follows:
301,068 / 677,264 * 885,315 = 393,554 tons.
This value matches the TRENDS activity spreadsheet.
For blast furnaces the activity is the fraction of lead recovered as antimonial lead to total lead
recovered multiplied by the total consumption of lead scrap. The amount recovered as antimonial
lead is also obtained from Table 11 and was 299,307 metric tons (329,238 short tons). The 1985
production from blast furnaces is calculated as follows:
72
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329,238 / 677,264 * 885,315 = 430,377 tons.
The TRENDS activity spreadsheet has a value of 391,300 tons for the secondary lead blast
furnaces. It appears as though the value in the TRENDS activity spreadsheet was not convened from
metric tons to short tons.
2.2.6.2 TRENDS Emission Factors
The emission factors cited in the TRENDS method are as follows.
SCC Description Emission Units
Factor
3-04-004-02 Secondary metal - Secondary lead 80 Ibs/ton lead produced
production: Reverberatory furnace
3-04-004-03 Secondary metal - Secondary lead 53 Ibs/ton lead produced
production: Blast furnace (Cupola)
These emission factors match the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants document.7
2.2.6.3 TRENDS Emissions
Using the activity data published in the TRENDS activity spreadsheet and the TRENDS
emission factor results in the following 1985 emissions:
(394,000 * 80 + 391,300 * 53)/ 2000 = 26,129 tons of S
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2.2.6.4 NAPAP Activity
The secondary lead production reported in NAPAP is 216,554 tons of metal charged to the
reverberatory furnace and 332,773 tons of metal charged to the blast furnace (cupola).
2.2.6.5 NAPAP Emissions
There are ten SCCs or processes listed for secondary lead production. Of these ten SCCs
only five have associated SO2 emissions. These are listed below.
SCC Description Tons SO,
Emitted
3-04-004-01 Secondary metal - Secondary lead: Pot furnace
3-04-004-02 Secondary metal - Secondary lead: Reverberatory furnace
3-04-004-03 Secondary metal - Secondary lead: Blast furnace (Cupola)
3-04-004-07 Secondary metal - Secondary lead: Pot furnace heater natural gas
3-04-004-99 Secondary metal - Secondary lead: Other not classified
Total 20,720
2.2.6.6 Conclusion
There is an apparent error in the TRENDS estimate because the activity value for the blast
furnace was not converted to english units. Following the TRENDS published procedure and
converting the activity data results in emissions of 27,147 tons of SO2. This is not a significant
difference in the published TRENDS estimate, because the values that are published are rounded to
the nearest 10,000 tons.
The TRENDS and NAPAP emission values are somewhat similar, however, the TRENDS
value is 30 percent higher than the NAPAP emissions. TRENDS does not account for SO, controls
such as baghouses and wet scrubbers.
74
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There is a new SCC, with an SO, emission factor of 144.0S Ibs SCyiO3 gallons burned, for
this category. The SCC is 3-04-004-07 for pot furnace heater burning distillate oil. This SCC is not
in the TRENDS method and it is not in the NAPAP inventory.
2.2.7 Other NAPAP Non-ferrous Emission Categories
In addition to the categories discussed above, NAPAP reports additional non-ferrous
emissions of 41,511 tons of SO2. The categories and the NAPAP emission estimates are summarized
in Table 2-10.
2.3 OTHER INDUSTRIAL PROCESSES
TRENDS estimates SO2 emissions from other industrial processes including pulp and paper,
chemical manufacturing, petroleum refining, iron and steel, and mineral products. Within the
chemical manufacturing group, TRENDS provides SO2 estimates for sulfuric acid and carbon black
manufacture. Within the mineral products group, TRENDS estimates SO2 emissions for cement,
glass, and lime manufacturing. Table 2-11 summarizes the 1985 TRENDS and NAPAP emission
estimates for these industrial processes.
The 1985 NAPAP emission inventory is a detailed database with emission estimates reported
in a record format. The total emissions reported for a source category is dependent upon the way in
which the emissions are summed. For industrial sources, the inclusion or exclusion of SO: emissions
from fuel combustion as opposed to process emissions can dramatically effect the emissions
associated with a particular source category. The NAPAP emission estimates reported in Table 2-11
were summed to allow comparison with the TRENDS source category estimates. For some source
categories fuel combustion emissions are included and for some source categories they are not
included.
75
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TABLE 2-10. OTHER NON-FERROUS EMISSIONS REPORTED
IN NAPAP
Primary and Secondary Metals
Source Category (SIC)
Ferroalloy (3313)
Molybdenum Ore Mining (1061)
Barium Ore Processing (3295)
Taconite Iron Ore Processing (1011)
Secondary Aluminum Production (3341,
sec
3-03-006
3-03-007
3-03-011
3-03-014
3-03-023
3-04-001
1985 NAPAP
(tons)3
10,016
986
2.514
1,547
3.768
3353, 3354, 3355, 3363, 3365)
Secondary Copper Production (3341, 3364,
3366)
3-04-002
Lead Battery Manufacture (3691)
Magnesium (3341)
Secondary Zinc Production (3341)
Furnace Electrode Manufacture (3624)
Fugitive Emissions (1000, 3300)
Process Heaters, Incinerators, and
Miscellaneous Not Classified
Total
3-04-005
3-04-006
3-04-008
3-04-020
3-03-888
3-03-900
3-03-999
3-04-999
1,347
27
3,094
3,979
12,060
2,165
41,511
*The 1985 NAPAP Emissions Inventory (version 2): Development of the Annual Data
and Modelers' Tapes, EPA-600/7-89-012a, November 1989.
2.3.1 Kraft Pulp Production
The 1985 TRENDS emission value is 250,000 tons SO2. The 1985 NAPAP value is 130,400
tons for both Kraft and sulfite pulp products.3 The discrepancy between the two inventories is
The NAPAP estimate of 130,400 tons if for emissions from the kraft and sulfite process. The
NAPAP estimate for all pulp and paper plants, including combustion emissions is 608 000 tons of
SO:
76
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TABLE 2-11. COMPARISON OF OTHER INDUSTRIAL PROCESSES
VALUES FOR 1985 TRENDS AND NAPAP
Category
Kraft Pulp Production (2611, 2621,
2631)
Emissions (tons)
Air-dry unbleached pulp
(103 tons)
Carbon Black Production (2895)
Emissions (tons)
Tons Produced (103 tons)
Sulfuric Acid Production (2819)
Emissions (tons)
Gross, new and fortified
(103 tons)
Sulfur Recovery Production
At Petroleum Refineries
(103 tons)
At Natural Gas Facilities
(103 tons)
Petroleum Refineries (2911)
F.C.C. Emissions (tons)
T.C.C Emissions (tons)
Flares Emissions (tons)
Process Heaters - Oil
Emissions (tons)
Process Heaters - Gas
Emissions (tons)
Sulfur Recovery Emissions
(tons)
Other NAPAP Refinery
Emissions (tons)
Total Emissions (tons)
TRENDS
Published
250,000
44,184
10,000
1,285.5
210,000
39,890
2,940
2,373
326,317
522
35,078
44,360
231,106
202,125
830,000*
TRENDS
Calculated
167,766
44,184
14,585
1,285
215,405
39,890
3,234
2,610
326,317
522
76,911
238,547
172,696
814,993
NAPAP
Published
130,400
29,399
28,000
1,111
217,000
204,647
7,273
15,671
117,512
117,237
29,117
149,925
640,000
(continued)
77
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TABLE 2-11. COMPARISON OF OTHER INDUSTRIAL
PROCESSES VALUES FOR 1985 TRENDS AND
NAPAP (Continued)
Category
Oil and Gas Production (1311)
Combustion Emissions (tons)
Sulfur Recovery Emissions (tons)
Other NAPAP Natural Gas
Production Emissions (tons)
Total Emissions (tons)
Iron and Steel Industry
Coke Emissions (tons)
Sintering Emissions (tons)
Open Hearth Furnace
Emissions (tons)
Roll and Finish (tons)
Other NAPAP Iron and
Steel Emissions (tons)
Total Emissions (tons)
Raw steel production (103
tons)
Cement Manufacturing (3241)
Emissions (tons)
Clinker produced (103 tons)
Glass Manufacturing (3211, 3221,
3229)
Emissions (tons)
103 Tons produced
Lime Manufacturing (3274)
Emissions (tons)
103 Tons Produced
Total Emissions (106 tons)
TRENDS
Published
441
163,143
160,000
162,000
21,000
4,650
168,000
360,000
88,300
620,000
77,895
30,000
16,245.8
30,000
15,800
2.5
TRENDS
Calculated
441
139,374
139,815
162,000
35,058
1,169
86,948
285,000
88,300
210,500"
77,895
28,508
16,245.8
42,000
15,800
1.9
NAPAP
Published
7,660
59,498
265,000
332,158
74,629
33,058
1,169
25,304
67,985
212,000
290,653
60,166
23,000
10,404
32,000
16,634
1.9
'Does not add to total due to independent rounding.
"Assuming no S0; controls.
78
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119,600 tons of SO2 (92 percent).
2.3.1.1 TRENDS Activity
In TRENDS, the production of sulfate and sulfite is obtained from Table 4 "Production and
Shipments of Woodpulp, by Type of Pulp: 1986 and 1985" of Current Industrial Reports: Pulp,
Paper and Board 1986." The production of sulfate (Kraft pulping) was 42,563,831 short tons in
1985. The production for sulfite was 1,620,084 short tons in 1985. The total production of
44,183,900 tons is consistent with the activity value published in the TRENDS activity spreadsheet.
2.3.1.2 TRENDS Emission Factor
The TRENDS procedure document lists SO2 emissions from two categories: Kraft pulping
(sulfate) and sulfite pulping. The emission factor for sulfate (kraft) pulping is 7.0 Ibs/air-dry ton of
unbleached pulp (SCC 3-07-001-04). This emission factor matches the AIRS Facility Subsystem
Source Classification Codes and Emission Factor Listing for Criteria Air Pollutants document.7
In the case of sulfite, the emission factor is derived from the uncontrolled factor (52 Ibs/ton)
and the controlled factor (20 Ibs/ton), both based on a now obsolete version of AP-4219, and the
assumption that 90 percent of production is at the controlled rate. The SO2 emission factor for
sulfite pulping is calculated as:
(52.0 * 0.10 + 20 * 0.90) = 23.2 Ibs/ton.
2.3.1.3 TRENDS Emissions
Emissions for kraft (sulfate) pulping are calculated from the Kraft production data.
42,563,831 * 7.0 / 2000 = 148,973 tons of SO,
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Emissions from sulfite pulping (assuming 90 percent control) are calculated from the
weighted emission factor and sulfite production.
1,620,084 * 23.2 / 2000 = 18,793 tons of SO2
Total emissions are simply the sum of Kraft and sulfite processes.
Total emissions = 148,973 + 18,793 = 167,766 tons of SO2
The sum of these estimates does not match the published TRENDS estimate. Because the
activity value did match the TRENDS spreadsheet, the emission factor was researched further.
Backcalculating the TRENDS emission factor from the published emission estimate (250,000 tons of
SO2) and the production data results in an overall emission factor of:
250,000/44,183,915 * 2000 =11.3 Ibs/ton.
An emission factor of 11.3 was apparently used in both the 1990 and 1991 TRENDS
estimate.
2.3.1.4 NAPAP Activity
The NAPAP production cannot be determined without a better understanding of the
woodpulping process. The production number for the recovery furnace direct contact evaporator in
the kraft pulping category is 29,398,475 air-dry tons of unbleached pulp. It is unclear if this
production should be added to other production numbers or if this value would represent all of the
reported pulp produced through the kraft process.
2.3.1.5 NAPAP Emissions
The NAPAP emissions for the Kraft and sulfite SCC codes are as follows.
Kraft:
80
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SCC Description Tons SO. Emitted
3-07-001-01 Pulp & Paper and Wood Products - Sulfate (Kraft) 159
Pulping: Digester Relief and Blow tank, general
3-07-001-02 Pulp & Paper and Wood Products Sulfate (Kraft) 17
Pulping: Washer/screens general
3-07-001-03 Pulp & Paper and Wood Products Sulfate (Kraft) 23
Pulping:
Multi-effect evaporator general
3-07-001-04 Pulp & Paper and Wood Products Sulfate (Kraft) 85.407
Pulping: Recovery Furnace Direct contact
evaporator
3-07-001-05 Pulp & Paper and Wood Products Sulfate (Kraft) 2.357
Pulping: Smelt dissolving tank general
3-07-001-06 Pulp & Paper and Wood Products - Sulfate (Kraft) 11,220
Pulping: Lime kiln general
3-07-001-08 Pulp & Paper and Wood Products - Sulfate (Kraft) 171
Pulping: Fluid bed calciner: general
3-07-001-09 Pulp & Paper and Wood Products - Sulfate (Kraft) 455
Pulping: Liquor oxidation tower, general
3-07-001-10 Pulp & Paper and Wood Products - Sulfate (Kraft) 22,870
Pulping: Recovery furnace indirect contact
evaporator
3-07-001-99 Pulp & Paper and Wood Products - Sulfate (Kraft) 43
Pulping: Other not classified
Total 122,722
Sulfite:
SCC Description Tons SO. Emitted
3-07-002-03 Pulp & Paper and Wood Products - Sulfite Pulping: 44
Digester blow pit dump tank: all bases except
Calcium
3-07-002-11 Pulp & Paper and Wood Products - Sulfite Pulping: 1,445
Digester blow pit dump tank: Calcium
3-07-002-14 Pulp & Paper and Wood Products - Sulfite Pulping: 1,362
Digester blow pit dump tank: NH3 with process
change
3-07-002-21 Pulp & Paper and Wood Products - Sulfite Pulping: 417
Recovery system MgO
3-07-002-22 Pulp & Paper and Wood Products - Sulfite Pulping: 543
Recovery system NH3
3-07-002-23 Pulp & Paper and Wood Products - Sulfite Pulping: 1,814
Recovery system Na
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SCC Description Tons SO. Emitted
3-07-002-31 Pulp & Paper and Wood Products - Sulfite Pulping: 193
Acid plant NH3
3-07-002-32 Pulp & Paper and Wood Products Sulfite Pulping: 5
Acid Plant Na
3-07-002-33 Pulp & Paper and Wood Products - Sulfite Pulping: 249
Acid plant Ca
3-07-002-34 Pulp & Paper and Wood Products Sulfite Pulping: 8
Knotters washers screens etc.
3-07-002-99 Pulp & Paper and Wood Products Sulfite Pulping: 608
Other not classified
Total 6,688
Additional emissions of 975 tons are listed in NAPAP for semi-chemical (neutral sulfite)
woodpulp pulping. Therefore, total pulp production emissions equal 130,385 tons of SO2.
2.3.1.6 Conclusion
For kraft pulping, the NAPAP and TRENDS activity values are 29,398,475 and 42,563,831
tons, respectively. The NAPAP production value does not report production for all of the records
where emissions are reported and therefore the production value is low relative to the emission
estimate.
The TRENDS method apparently used an emission factor of 11.3 to calculate kraft emissions,
when a more appropriate value would have been 7 Ibs/ton of air-dry unbleached pulp. It is unclear
how the overall emission factor of 11.3 Ibs/ton of air-dry unbleached pulp was derived; it was not
derived from the methodology listed in the TRENDS procedures manual, at least not for the 1985
study year. The 11.3 emission factor is significantly higher (nearly 50 percent) than one calculated
following the TRENDS procedure. The TRENDS emission estimation procedures from the pulp
industry should be revisited based on seeming discrepancies in the TRENDS emission factor(s) and
the development of new emission factors. Based solely on the discrepancy, TRENDS emissions may
be overstated by nearly 70,000 tons. Also, TRENDS does not account for the effect of any controls.
These two issues could result in an overestimation of SO: emissions from wood pulping processes.
82
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The TRENDS procedure does not include a third type of paper pulping process, semi-
chemical. Activity data for semi-chemical pulping are available and emission factors exist in the
AP-42.19 Published statistics indicate that semi-chemical has recently overtaken sulfite (3.9 x 106
versus 1.6 x 106 tons of production). If the semichemical production is increasing with fewer
associated SO: emissions, this is an industry trend that should be reflected in the emission estimates.
The TRENDS procedure needs to be revised to account for the new emission factors that
have been developed in 1990. The vast majority of pulp is produced through the Kraft process.
therefore expenditure of significant effort to improve the sulfite factor may not be warranted. The
TRENDS number should be produced as at least two separate numbers, Kraft and sulfite, but
possibly as three numbers to include semi-chemical. The TRENDS procedure should also be
rewritten to document the development of the emission factor and control assumptions.
2.3.2 Chemical Manufacturing
Within the chemical manufacturing group, TRENDS estimates SO2 emissions for carbon black
and sulfuric acid manufacture. TRENDS also estimates elemental sulfur production, however, the
emissions are categorized as recovered sulfur within the petroleum refining and natural gas
production categories.
2.3.3 Carbon Black Production
The 1985 TRENDS emission value is 10,000 tons SO2. The 1985 NAPAP value is 28.000
for carbon black production. The discrepancy between the two inventories is 18,000 tons of SO: (64
percent).
TRENDS carbon black activity
The total production of carbon black produced as reported in "Facts and Figures for the
Chemical Industry" in the Chemical and Engineering News is 2.57 billion pounds in 1985.1: This is
equivalent to a 1985 production value of 1.285,000 tons. This value matches the TRENDS activity
83
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spreadsheet Carbon black production is divided into oil and gas processes; TRENDS creates this
split using a fixed assumption (i.e., this split is not updated annually).
Oil Process: 90 percent of total production
Gas Process: 10 percent of total production
TRENDS carbon black emission factors
The TRENDS methodology relies on the emission factor for the flared furnace published in
Table 5.3-3, AP-42 (Fourth Edition)19 (there are no SO, emission factors in the AIRS SCC
document). The TRENDS procedure starts with uncontrolled emissions.
Description Ibs SO./ton
Flared Furnace Exhaust (Oil Process) 50
The TRENDS methodology for the remaining steps is not clear. The procedures manual
states that a controlled emission factor (based on CO control efficiency) is calculated as follows:
EF = CO Control Efficiency * 50 Ibs/ton.
The emission factor reported in the TRENDS printout is 22.7 Ibs/ton, indicating a CO control
efficiency of:
CO control efficiency = 22.7 / 50 = 0.454 or 45 percent.
It is not clear if this control efficiency is to be applied to CO emissions or if the control
efficiency is the result of a CO boiler and incinerator. The CO boiler and incinerator has a lower
SO, emission factor than the flare (35.2 Ib/ton versus 50 Ib/ton).
There is no emission factor reported for the gas process. In addition, it does not appear that
the activity value is weighted toward oil versus gas.
84
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TRENDS carbon black emissions
Using the TRENDS emission factor results in emissions of:
1,285,000 * 22.7 / 2000 = 14,585 tons of SO,.
The published TRENDS value is rounded to the nearest 10,000 tons and is therefore reported
as 10,000 tons of SO:.
NAPAP carbon black activity
The 1985 NAPAP inventory reports the following nine separate SCCs.
SCC Description
3-01-005-01 Chemical manufacturing - Carbon Black Production:
Channel Process
3-01-005-02 Chemical manufacturing - Carbon Black Production:
Thermal Process
3-01-005-03 Chemical manufacturing - Carbon Black Production:
Gas Furnace Process, Main Vent
3-01-005-04 Chemical manufacturing - Carbon Black Production:
Oil Furnace Process, Main Vent
3-01-005-06 Chemical manufacturing - Carbon Black Production:
Transport Air Vent
3-01-005-07 Chemical manufacturing - Carbon Black Production:
Pellet Dryer
3-01-005-08 Chemical manufacturing - Carbon Black Production:
Bagging/Loading
3-01-005-09 Chemical manufacturing - Carbon Black Production:
Furnace Process, Fugitives
3-01-005-99 Chemical manufacturing - Carbon Black Production:
Other Not Classified
NAPAP carbon black emissions
Tons produced
29,000
0
98,179
1,013,232
821,308
981.213
38,600
15,824
134.879
The following emissions are reported for Carbon Black Production in the NAPAP inventory:
85
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SCC
3-01-005-01
3-01-005-02
3-01-005-03
3-01-005-04
3-01-005-06
3-01-005-07
3-01-005-08
3-01-005-09
3-01-005-99
TOTAL
Conclusion
Description
Chemical manufacturing Carbon
Channel Process
Chemical manufacturing - Carbon
Thermal Process
Chemical manufacturing - Carbon
Gas Furnace Process, Main Vent
Chemical manufacturing Carbon
Oil Furnace Process, Main Vent
Chemical manufacturing - Carbon
Transport Air Vent
Chemical manufacturing Carbon
Pellet Dryer
Chemical manufacturing - Carbon
Bagging/Loading
Chemical manufacturing - Carbon
Furnace Process, Fugitives
Chemical manufacturing - Carbon
Other Not Classified
s SO. Emitted
Black Production:
Black Production:
Black Production:
Black Production:
Black Production:
Black Production:
Black Production:
Black Production:
Black Production:
10
197
1,075
3.958
2.410
15.183
642
4,013
543
28,031
The carbon black production emission estimates are 28,031 tons of SO2 in NAPAP versus
14,585 tons of SO2 in TRENDS. The TRENDS method appears to underestimate the emissions from
carbon black manufacture.
The total NAPAP production for the oil furnace of 1,013,232 is very similar to the value
TRENDS references (90 percent of total production) 1,156,500. The NAPAP value for the gas
furnace 98,179 is less similar to the value TRENDS references (10 percent of total production of
128,500 tons).
Two questionable items need to be addressed regarding the NAPAP emission estimates and
the TRENDS emission factor. The NAPAP emission estimates by SCC show only a minority of
emissions from the oil furnace (3,958 out of 28,031 tons), although logically this would be the
source of most emissions. However, the pellet dryer combustion furnace (with emissions of 15.183
86
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tons) is, in essence, a thermal incinerator and emissions associated with the furnace itself are emitted
here. It is likely that engineers coding the NAPAP inventory indicated the vents as discrete emission
points in addition to the oil furnace emission source.
Second, the TRENDS emission factor appears to be too small. The TRENDS procedure
initially has a fairly high emission factor of 50 Ibs/ton for the flare from an oil furnace process (this
emission factor is supported by AP-42). If a CO boiler and incinerator exist, primarily to control CO
emissions, the AP-42 SO; emission factor drops to 35.2 Ibs/ton. It is unlikely that the emission
factor would drop as low as 22.7 Ibs/ton (the TRENDS number), even if all sources had a CO boiler
and incinerator.
If the TRENDS estimate were computed with the original emission factor of 50 Ibs/ton, the
TRENDS emissions would be:
1,285,000 * 50 / 2000 = 32,125 tons of SO2.
This value is very close to the NAPAP estimate of 28,031 tons of SO2.
If all the sources are assumed to be controlled with a CO boiler and incinerator, the emission
factor would be 35.2 Ibs/ton and the emissions would be:
1,285,000 * 35.2 / 2000 = 22,616 tons of SO2.
As noted, the largest source of emissions in NAPAP is for the pellet dryer. There is no
corresponding category in TRENDS for the pellet dryer, although it is likely that emissions have
been accounted for. As stated earlier, there is no NAPAP category specifically for the flare.
however, the flare actually represents otherwise uncontrolled oil furnace emissions.
The TRENDS documentation probably needs to be modified to ensure that all emission points
and sources are included. Further investigation of the NAPAP value is warranted to determine why
emissions associated with the oil furnace were distributed to other emission points (vents) if possible.
87
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Finally, the assumption that flares represent otherwise uncontrolled emissions could be confirmed by
looking at the control equipment for these sources coded in NAPAP.
2.3.4 Sulfuric Acid
The 1985 TRENDS value is 210,000 tons SO2. The 1985 NAPAP value is 217,000 for
sulfuric acid production. The discrepancy between the two inventories is 7,000 tons of SO; (3
percent).
TRENDS sulfuric acid activity
The 1985 production of sulfuric acid was obtained from Table 1 "Production and Shipments
of Selected Inorganic Chemicals: 1982 to 1986" of Current Industrial Reports, Inorganic
Chemicals2* and was 39,889,900 short tons, gross (new and fortified).
The 1984 production is used in the calculation of the emission factor. The 1984 production
was obtained from the same source and was 41,801,900 short tons. The TRENDS activity
spreadsheet lists the 1984 production as 39,683,000 tons of sulfuric acid.
TRENDS sulfuric acid emission factor
The TRENDS procedure manual provides the following equation for the development of an
SO2 emission factor. The equation assumes that each year 5 percent of the existing production
comes into compliance with the New Source Performance Standard (NSPS)b and any new production
will also be in compliance with the NSPS.
EF, = (0.95 * EF., * P.,,) + (0.05 * EF..W * P..,) + ((P. - P.,) * EFM,0J
P,
40 CFR Section 60 Subpart H.
88
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where,
i = 1985
EFNSPS = NSPS emission factor (4 Ibs SCyton of 100 percent H2SO4 production)
P = Total Production
Because the production for 1985 (P,) is less than the production for 1984 (P^,) (based on the
information in Current Industrial Reports), the last term in the equation should be set to zero.
Emissions from new capacity at the NSPS emission level should only apply to production above the
previous record-high production level.
In order to apply this equation, one must know the 1984 emission factor. The 1984 emission
factor is backed out based on the 1984 production (as reported in the TRENDS activity spreadsheet)
and the 1984 published TRENDS emission estimate. Note that the published TRENDS 1984
activity is lower than the 1985 production which reintroduces the last term of the equation. The
1984 emission factor is:
210,000 / 39,683,000 * 2000 = 10.6 Ib/ton of H,SO4 production.
The 1985 emission factor is then calculated using the above equation:
EF1985 = [(0.95 * EF1984 * P19M) + (0.05 * 4 * P1984) + (P1985 - P1984 * 4] / P1985
= [(0.95*10.6*39,683,000)+(0.05*4*39,683,000)+(206,900*4)]/39,889,900
= 10.2 Ib/ton of sulfuric acid produced
(The emission factor for 1985 that is backcalculated based on the published TRENDS
emission estimate and the 1985 production is 10.5 Ib/ton of sulfuric acid produced.)
89
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TRENDS sulfuric acid emissions
The TRENDS emissions were not calculated using the emission factor derived from the
equation, rather the emissions were calculated using an emission factor of 10.5 Ib/ton of sulfuric acid
produced. The emissions were calculated as follows:
39,889,900 * 10.5 / 2000 = 209,421 tons of SO,.
If the TRENDS procedure is followed and the correct 1984 activity data are used, the
emission factor for 1985 would be 10.8 Ib/ton of sulfuric acid produced and the 1985 emissions
would be slightly higher.
39,889,900 * 10.8 / 2000 = 215,405 tons of SO2.
NAPAP sulfuric acid activity
The 1985 NAPAP inventory reports production for sulfuric acid production as follows.
SCC Description Tons 100%
3-01-022-01
3-01-023-01
3-01-023-04
3-01-023-06
3-01-023-08
3-01-023-10
3-01-023-12
3-01-023-18
Chemical Manufacturing - Sulfuric Acid
process: general
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.9% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.5% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 98.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 97.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 96.0% conversion
Chemical Manufacturing Sulfuric Acid
- Chamber
- Contact
- Contact
- Contact
- Contact
- Contact
Contact
- Contact
211,236
14,886,621
1,592,842
3,462,965
7,113.929
2,842,025
40,588
3,552,216
process: absorber @ 93.0% conversion
90
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sec
3-01-023-19
3-01-023-20
3-01-023-21
3-01-023-22
3-01-023-99
NAPAP sulfuric
The 1985
sec
3-01-022-01
3-01-023-01
3-01-023-04
3-01-023-06
3-01-023-08
3-01-023-10
3-01-023-12
3-01-023-18
3-01-023-19
3-01-023-20
3-01-023-21
3-01-023-22
Description
Chemical Manufacturing - Sulfuric Acid
process: Concentrator
Chemical Manufacturing Sulfuric Acid
process: Tank car and truck unloading
Chemical Manufacturing - Sulfuric Acid
process: Storage tank vent
Chemical Manufacturing - Sulfuric Acid
process: Process equipment leaks
Chemical Manufacturing Sulfuric Acid
process: Other Not Classified
acid emissions
- Contact
- Contact
Contact
- Contact
Contact
Tons 100%
H.SO.
40,050
247,520
2,335.790
278,551
437.373
reported emissions for sulfuric acid production are as follows.
Description
Chemical Manufacturing - Sulfuric Acid
process: general
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.9% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.5% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 99.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 98.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 97.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 96.0% conversion
Chemical Manufacturing - Sulfuric Acid
process: absorber @ 93.0% conversion
Chemical Manufacturing Sulfuric Acid
process: Concentrator
Chemical Manufacturing - Sulfuric Acid
process: Tank car and truck unloading
Chemical Manufacturing - Sulfuric Acid
process: Storage tank vent
Chemical Manufacturing - Sulfuric Acid
process: Process equipment leaks
Tons
- Chamber
- Contact
- Contact
- Contact
- Contact
- Contact
- Contact
- Contact
- Contact
Contact
- Contact
- Contact
SO, Emitted
2,091
32,947
4,300
13,551
76,707
25,893
1,445
10,905
0
1
94
46,930
91
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SCC Description Tons SO. Emitted
3-01-023-99 Chemical Manufacturing - Sulfuric Acid - Contact 2.302
process: Other Not Classified
Total 217,166
Conclusions
The NAPAP estimate of 217,166 tons of SO: is extremely close to the TRENDS estimate of
215.405 tons of SO,. Nevertheless, the origin of the initial emission factor in the TRENDS
procedure is not documented and therefore the emission factor for the category is somewhat suspect.
One concern about this category is the production of H;SO4 from recovered sulfur. The NSPS does
not apply to sulfuric acid production in conjunction with SO2 controls. It is unclear if the NAPAP
data reflect only the chemical companies producing sulfuric acid or also include byproduct H2S04
production.
There appears to be an error in the emission factor used to develop the published TRENDS
estimate. If the TRENDS procedure is followed in the development of the 1985 emission factor
(using the 1984 emission factor and the correct 1984 production), the 1985 emission factor is 10.8
Ib/ton of sulfuric acid produced as opposed to the value of 10.5 Ib/ton of sulfuric acid produced,
which was apparently used in the published TRENDS report.
The NSPS emission factor of 4 Ib SOj/ton of 100 percent sulfuric acid produced is consistent
with the emission factor for sulfuric acid contact process, 99.9 percent conversion (SCC 3-01-023-
01). As shown in the NAPAP data, the activity for that SCC dominates the category. An analysis of
the penetration of the NSPS emission limit into this source category could be conducted by
contacting the Stationary Source Compliance Division of OAQPS and by analyzing the BACT/LAER
Clearinghouse. As stated above, the estimates are extremely close and may not warrant any further
investigation.
An analysis of the production data provided in Current Industrial Reports, Inorganic
Chemicals24 reveals that production had a low value of 33,233,000 tons of sulfuric acid in 1982 and
a high of 44,336,818 in 1990. Because the NSPS was promulgated in the 1970's, production over
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33,233,000 (and at least 25 percent of production) should be at the NSPS level. The NAPAP data
indicate that approximately 50 percent of 1985 production was at the NSPS level.
2.3.5 Sulfur Recovery Plants
TRENDS reports SO: emissions from sulfur recovery plants in two categories, natural gas
production and petroleum refining. As a result, it is not possible to directly assess whether the
published TRENDS emission estimates were successfully recreated due to errors in both the
published TRENDS activity data and emission factors. The TRENDS emission estimates using the
erroneous TRENDS spreadsheet information are 202,000 tons for petroleum refineries and 163,000
tons for natural gas production. The corresponding NAPAP emission estimates are 29,000 tons for
petroleum refineries and 59,000 tons for natural gas production.
2.3.5.1 TRENDS Activity
The quantity of sulfur recovered by natural gas plants and petroleum refineries in 1985 is
reported in Table 4 "Recovered Sulfur Produced and Shipped in the United States" of Minerals
Yearbook 1989 "Sulfur."4 The production at petroleum refineries was 2,940,000 metric tons
(3,234,000 short tons) and the production at natural gas plants was 2,373,000 metric tons (2,610,000
short tons).
The TRENDS activity spreadsheet erroneously left these activity rates in metric units.
2.3.5.2 TRENDS Emission Factors
According to the TRENDS procedure manual, the emission factor is derived annually from
the emissions and throughput reported to AIRS/FS in SCC 3-01-032-01 through 3-01-032-04. In
1985 the throughput values were reported as follows.
SCC Description Tons 100% Sulfur
3-01-032-01 Chemical Manufacturing Elemental Sulfur Production: 154,728
Mod. Glaus: 2 stage w/o control (92-95% removal)
93
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sec
3-01-032-02
3-01-032-03
3-01-032-04
Total
Description
Chemical Manufacturing - Elemental Sulfur Production:
Mod. Claus: 3 stage w/o control (95-96% removal)
Chemical Manufacturing Elemental Sulfur Production:
Mod. Claus: 4 stage w/o control (96-97% removal)
Chemical Manufacturing Elemental Sulfur Production:
Sulfur removal process (99.9% removal)
In 1985 the emissions were reported as follows.
SCC
3-01-032-01
3-01-032-02
3-01-032-03
3-01-032-04
Total
Description
Chemical Manufacturing Elemental Sulfur Production:
Mod. Claus: 2 stage w/o control (92-95% removal)
Chemical Manufacturing - Elemental Sulfur Production:
Mod. Claus: 3 stage w/o control (95-96% removal)
Chemical Manufacturing - Elemental Sulfur Production:
Mod. Claus: 4 stage w/o control (96-97% removal)
Chemical Manufacturing - Elemental Sulfur Production:
Sulfur removal process (99.9% removal)
Tons 100% Sulfur
754,087
105,890
1.374.263
2.388,968
Tons SO. Emitted
32.566
30,301
5,281
59.386
127,534
The emission factor is obtained by dividing the total emissions by the sum of the operating
rates. The emission factor for 1985 should be:
127,534 / 2,388,968 * 2000 = 106.8 Ibs/ton of sulfur.
The emission factor reported through the TRENDS spreadsheets for both 1990 and 1991 is
137.5 Ib/ton of sulfur produced.
2.3.5.3 TRENDS Emissions
The TRENDS emission estimates are calculated for both natural gas production and petroleum
refining using the emission factor of 137.5 Ib/ton of sulfur produced and the production rates in the
TRENDS activity spreadsheet For petroleum refineries the emissions are 202,125 tons:
2,940,000 * 137.5 / 2000 = 202,125 tons SO,
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The emissions for natural gas fields are 163,143 tons:
2,373,000 * 137.5 / 2000 = 163,143 tons SO2
The total emissions are 365,269 tons:
202,125 + 163,143 = 365,269 tons SO2
Using the emission factor of 106.8 Ibs/ton of sulfur produced derived by following the
TRENDS procedure manual and the correct activity data would result in the following emission
estimates for petroleum refineries:
3,234,000 * 106.8 / 2000 = 172,696 tons SO2
The emissions at natural gas fields are 139,374 tons:
2,610,000 * 106.8 / 2000 = 139,374 tons SO2
The total emissions are 312,070 tons:
172,696 + 139,374 = 312,070 tons SO2
2.3.5.4 NAPAP Activity
The 1985 reported throughput values were reported above. In addition NAPAP reports
191,676 tons product under Other not classified. The production sums to 2,580,644 tons of
recovered sulfur versus the 5,844,000 tons reported through the Minerals Yearbook.4 Only half of
the records that reported sulfur emissions reported a sulfur production or throughput value.
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2.3.5.5 NAPAP Emissions
In order to split the emissions between petroleum refineries and natural gas production, the
sulfur production emissions were put in a matrix of the SCC versus the SIC. The matrix is presented
below.
SO2 EMISSIONS (tons)
SIC
1300
1311
1321
2801
2819
2869
2911
3011
4922
Total
Description
Oil and Gas Extraction
Crude Petroleum and Natural
gas
Natural gas liquids
Chemicals and Allied Products
Industrial Inorganic Chemicals,
Not elsewhere classified
Industrial Organic Chemicals,
Not elsewhere classified
Petroleum Refining
Tires and Inner Tubes
Natural Gas Transmission
Other Not Classified
SCC
30103201
9,829
4,482
5,366
5,674
7,175
40
32,566
sec
30103202
541
9,897
4,875
1,133
12,100
1,756
30,302
see
30103203
670
2,629
908
982
92
5,281
sec
30103204
21,807
7,887
19,942
9,750
59,386
Total
541
42.203
14.998
908
31,165
6,807
29,117
40
1,756
1,171
128,706
Natural gas production includes emissions from four SIC's: 1300, 1311, 1321, and 4922 and
were 59,498 tons of S02. Petroleum Refining was represented by only one SIC and emissions were
29,117 tons of S02. In the NAPAP inventory, tire and chemical production were responsible for the
remaining 38,920 tons of SO2. In addition, NAPAP reports 1,171 tons of SO2 emissions under Other
not classified. The total NAPAP emissions sum to 128,706 tons of SO2.
2.3.5.6 Conclusion
TRENDS reports SO2 emissions from sulfur recovery plants in two categories, natural eas
production and petroleum refining. As a result, it is not possible to directly assess whether the
96
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published emission estimates were successfully recreated, although using the emission estimates does
allow the total natural gas production and total petroleum refinery estimates to match the published
values. Errors were discovered in both the activity data and the emission factors that were used to
calculate the published 1985 TRENDS estimates. As a result, the published TRENDS emission
estimate is too high. The estimates using the erroneous information are 202,000 tons for petroleum
refineries and 163,000 tons for natural gas production. The corresponding NAPAP emission
estimates are 29,117 tons for petroleum refineries and 59,498 tons for natural gas production.
In the TRENDS estimate, the activity data were erroneously left in metric units rather than
converted to english units. The emission factor was not calculated from AIRS data, as the procedure
manual indicated, but rather was held constant. Using the revised emission factor (106.8 Ibs/ton of
sulfur produced versus 137.5 Ibs/ton of sulfur produced) and corrected activity data resulted in
TRENDS emission estimates of 172,696 tons for petroleum refineries and 139,374 tons for natural
gas production (a decrease of 53,198 tons of
The estimates in NAPAP and TRENDS are still very different; 312,070 versus 88,615 tons of
SO2. The TRENDS method, when applied correctly, probably overestimates emissions from sulfur
recovery plants. NAPAP may underestimate emissions from sulfur recovery plants or the emissions
may be reported in other areas of the inventory (i.e., under petroleum refining or natural gas
production as opposed to sulfur production).
The emission factors reported in the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 are as follows.
SCC Description Emission Units
Factor
3-01-032-01 Chemical Manufacturing Elemental Sulfur 280 Ib/tons
Production: Mod. Claus: 2 stage w/o control (92- 100% sulfur
95% removal)
3-01-032-02 Chemical Manufacturing - Elemental Sulfur 189 Ib/tons
Production: Mod. Claus: 3 stage w/o control (95- 100% sulfur
96% removal)
3-01-032-03 Chemical Manufacturing Elemental Sulfur 145 Ib/tons
Production: Mod. Claus: 4 stage w/o control (96- 100% sulfur
97% removal)
97
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SCC Description Emission Units
Factor
3-01-032-04 Chemical Manufacturing - Elemental Sulfur 4 Ib/tons
Production: Sulfur removal process (99.9% 100% sulfur
removal)
Multiplying the NAPAP sulfur recovery production values by these emission factors results in
total emissions of 103,348 tons of SO2. There is a discrepancy between the production values.
emission factors, and reported emissions in the NAPAP inventory. The emissions for 95-96 percent
recovery appear to be underestimated and the emissions for 99.9 percent recovery appear to be
overestimated. Therefore, there are probably errors in the NAPAP values, either in the reported
production or in the reported emissions.
Additional research should be expended on this category to try and determine what types of
sulfur recovery plants are in use in petroleum refineries and natural gas production fields. Once
there is additional information, a new appropriately weighted emission factor could be developed for
the TRENDS procedure.
2.3.6 Petroleum Refineries
In TRENDS the SO2 emissions from petroleum refineries are reported for six categories:
Thermal Catalytic Cracking; Fluid Catalytic Cracking; Flares; Process Heaters Oil; Process Heater -
Gas; and Sulfur Recovery. The 1985 TRENDS value is 830,000 tons SO2. The 1985 NAPAP value
for the same six categories is 490,000 tons of SO2, although the total petroleum refining estimate is
640,000 tons of SO2. The difference between the two petroleum refining emission estimates is
190,000 tons of SO2 (30 percent).
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2.3.6.1 TRENDS Activity
The TRENDS activity data are presented below for the six categories. The full discussion of
the derivation of sulfur recovery emissions was presented earlier but is summarized below. In all of
the categories except sulfur recovery, the activity data derived following the TRENDS procedure
manual were consistent with the published TRENDS activity spreadsheet.
Catalytic cracking
In TRENDS, the petroleum production activity data were obtained from the "Annual Refining
Survey" of the Oil & Gas Journal? Prior to 1989, the survey also provided the split between fluid
catalytic cracking (FCC) and thermal catalytic cracking (TCC or thermofor). Within the survey.
footnotes indicate whether the fresh feed for catalytic cracking is fluid or "other". "Other" represents
thermal cracking. The TRENDS method has changed recently due to the discontinuation of the
reporting of fluid versus thermal catalytic cracking. The following discussion pertains to the
documented method for the development of the 1985 estimates.
The total capacity of catalytic cracking fresh feed is obtained from the Annual Refining
Survey in the Oil and Gas Journal?5 The total fresh feed, catalytic cracking, charge capacity as of
January 1, 1986 was 5,234,100 barrels per stream day.
To convert from capacity to annual throughput, the ratio of production to capacity is obtained
from the Bureau of Economic Analysis, Refinery Operating Ratio, Crude Petroleum.26 For 1985 the
value is 78 percent. The conversion factor for stream day to year is 328.5 (365 calendar days per
year * 0.9 calendar day per stream day).
Total 1985 catalytic cracking throughput was:
5,234,100 * 328.5 * 0.78 = 1,341,133,000 barrels/year.
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In the Annual Refining Survey, the Oil & Gas Journal25 differentiates between "Fluid" and
"Other" catalytic cracking. Fluid cracking was 5,166,300 barrels per stream day (1,323,761,000
barrels/year). Other (thermal) was 67,800 barrels per stream day (17,372,394 barrels/year).
FCC = 1,323,761 x 103 bbl/year
TCC = 17,372 x 103 bbl/year
Flares
The activity for flares is derived from the total refinery crude capacity. This capacity is
converted to an annual value and is multiplied by the percent control efficiency for blowdown
systems from the TRENDS procedure volatile organic compound (VOC) section.
The TRENDS activity spreadsheet reports a 1985 value as 2,608 x 106 bbl.
Process heaters
Process heater emissions are divided into oil and gas. Both categories use activity data from
Table 43 "Fuels Consumed at Refineries by PAD District, 1985" of Petroleum Supply Annual I9855
The quantity of oil consumed at petroleum refineries is the sum of distillate, residual, and
crude oil. The oil consumed in 1985 was reported as:
758 + 84 + 13,326 = 14,168 x 103 barrels = 595,056 x 103 gallons.
The quantity of gas consumed at petroleum refineries is the sum of natural gas and still
(process) gas. Natural gas is reported in 106 ft3 (million cubic feet). Still (process) gas is reported in
103 bbl and must be converted using the conversion factor of 6.3 x 106 ft3/103 barrel equivalent The
gas consumed in 1985 was reported as:
487,830 + 212,443 * 6.3 = 1,826,220 x 106 ft3.
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Sulfur recovery
The quantity of sulfur recovered by petroleum refineries in 1985 is reported in Table 4
"Recovered Sulfur Produced and Shipped in the United States" of Minerals Yearbook 1989 "Sulfur."4
The production from petroleum refineries was 2,940,000 metric tons (3,234,000 short tons). The
TRENDS activity spreadsheet erroneously left this activity rate in metric units.
2.3.6.2 TRENDS Emission Factors
The emission factors for this category are rather complex. The emission factors cited in the
TRENDS procedures manual or in the TRENDS spreadsheets are as follows.
SCC Description Emission Factor Units
3-06-001-05 Petroleum Industry - Process 0.6 lbs/106 ft3 burned
Heaters: Natural Gas-fired
3-06-001-06 Petroleum Industry - Process 950.0S lbs/106 ft3 burned
Heaters: Process Gas-fired
3-06-002-01 Petroleum Industry - Fluid 493 lbs/103 BBL fresh feed
Catalytic Cracking Units
3-06-002-02 Petroleum Industry - Thermal 60 lbs/103 BBL fresh feed
[sic] Catalytic Cracking Units
3-06-004-01 Petroleum Industry - 26.9 lbs/103 BBL refinery
Blowdown systems: w/ vapor feed
recovery sys. w/ flaring
1-02-004-01 External Combustion Boilers - 158.6S lbs/103 gallon burned
Industrial - Residual Oil:
Grade 6 oil
The SCC for thermal catalytic cracking (3-06-002-02) appears to be a typographical error.
The correct SCC for thermal catalytic cracking units is 3-06-003-01. The SCC 3-06-003-01 will be
used throughout the rest of this discussion.
These emission factors match the document AIRS Facility Subsystem Source Classification
Codes and Emission Factor Listing for Criteria Air Pollutants.1 The TRENDS procedure manual
instructs the user to use the TRENDS emission factor for industrial - residual oil boilers and also to
estimate the sulfur content from a standard AIRS report for SCC 3-06-001-03 (Petroleum Industry -
Process Heaters: Oil fired). These two instructions are inconsistent because the TRENDS procedure
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for industrial-residual oil does not use the AIRS sulfur content. The average sulfur content as
reported in NAPAP for SCC 3-06-001-03 is 1.09 percent, resulting in an emission factor of:
158.6 * 1.09 = 172.8 lb/103 gallon burned.
The emission factor for the TRENDS industrial residual oil category is based on a sulfur content
from Heating Oils, 79S56 and for 1985 this was calculated as 1.63 percent. This results in an
emission factor of:
158.6 * 1.63 = 258.5 lb/103 gallon burned.
Finally, the TRENDS spreadsheets for both the 1990 and 1991 estimates used an emission factor of
6248 lbs/103 bbl burned (148.76 lbs/103 gallon burned). This translates to a sulfur content of 0.94
percent.
The emission factor for natural gas and refinery gas is to be weighted based on the
throughput listed in Table 43 "Fuels Consumed at Refineries by PAD District, 1985" of Perroleum
Supply Annual 1985.5 The emission factor for refinery gas is listed in the TRENDS procedures
manual as 356.25 lbs/106 ft3. This translates into an assumed sulfur content of 0.375 percent. The
emission factor for combustion of natural gas is 0.6 lbs/106 ft3. The total gas combustion is
1,826,220 x 106 ft3. Natural gas is 26.7 percent of the total gas burned and process gas is 73.3
percent of the total gas burned. Therefore the weighted emission factor is:
0.267 * 0.6 + 0.733 * 356.25 = 261 lb/106 ft3 burned.
The weighted average emission factor in the TRENDS spreadsheet for process heaters gas
combustion was 253.1 for both 1990 and 1991.
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Sulfur Recovery
According to the TRENDS procedure manual, the emission factor is derived annually from
the emissions and throughput reported to AIRS/FS in SCC 3-01-032-01 through 3-01-032-04. In
1985 the throughput values were reported as 2,388,968 tons of sulfur. In 1985 the emissions are
reported as 127,534 tons of SO2. The emission factor is obtained by dividing the total emissions by
the sum of the operating rates. The emission factor for 1985 should be:
127,534 / 2,388,968 * 2000 = 106.8 Ibs/ton of sulfur.
The emission factor reported through the TRENDS spreadsheets for both 1990 and 1991 is
137.5 Ib/ton of sulfur produced.
2.3.6.3 TRENDS Emissions
Using the TRENDS emission factors and activity data published in the TRENDS activity
spreadsheet and adding the emissions from sulfur recovery described in the preceding section, results
in the following 1985 emissions.
Description Tons SCX Emitted
Fluid Catalytic Cracking 326,317
Thermal Catalytic Cracking 522
Flares (Blowdown System) 35,078
Process Heaters: Oil 44,360
Process Heaters: Gas 231,106
Sulfur Recovery Units 202.125
Total 839,508
The published TRENDS value is 830,000 tons. The discrepancy may be due to independent
rounding or an incorrect assumption in the recreation of the TRENDS emission estimates.
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2.3.6.4 NAPAP Activity
NAPAP activity data are presented below for comparative purposes. These data were not
priority elements for all sources in that inventory.
Value Units
sec
Description
1-02-007-01 External Combustion Boilers
Industrial: Process Gas,
Petroleum Refining Gas
3-06-001-01 Petroleum Industry - Process
heaters: Oil fired
3-06-001-02 Petroleum Industry - Process
heaters: Gas fired
3-06-001-03 Petroleum Industry - Process
heaters: Oil fired
3-06-001-04 Petroleum Industry - Process
heaters: Gas fired
3-06-001-05 Petroleum Industry - Process
heaters: Natural gas fired
3-06-001-06 Petroleum Industry - Process
heaters: Process gas fired
3-06-002-01 Petroleum Industry - Fluid
catalytic cracking unit
3-06-003-01 Petroleum Industry - Thermal
catalytic cracking unit
3-06-004-01 Petroleum Industry -
Slowdown systems: w/ vapor
recovery sys. w/ flaring
3-06-004-02 Petroleum Industry -
Blowdown systems: w/o
controls
1-02-004-01 External Combustion
Industrial: Residual oil, grade
6 oil
17,345 106 ft3 gas burned
62,040 103 bbls oil burned
116,387,121 103 ft3 gas burned
11,747,943 103 gallons oil burned
38,503,093 106 ft3 gas burned
311,504 106 ft3 gas burned
155,477 106 ft3 gas burned
1,584,926 103 bbls fresh feed
171,954 103 bbls fresh feed
11,603,678 103 bbls refinery feed
519,999 103 bbls refinery feed
3,679,030 103 gallons oil burned
Additional NAPAP production was added for two categories of process heaters burning oil
(3-06-001-01 and 03), and two categories of process heaters burning gas (3-06-001-02 and 04).
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2.3.6.5 NAPAP Emissions
The following emission estimates were reported through NAPAP for the categories of
petroleum refining emissions that are estimated in the TRENDS method:
SCC Description
1-02-007-01 External Combustion Boilers Industrial: Process
Gas, Petroleum Refining Gas
3-01-032-01 Chemical Manufacturing Elemental Sulfur
Production: Mod. Glaus: 2 stage w/o control (92-
95% removal) (SIC 2911 only)
3-01-032-02 Chemical Manufacturing Elemental Sulfur
Production: Mod. Glaus: 2 stage w/o control (95-
96% removal) (SIC 2911 only)
3-01-032-03 Chemical Manufacturing - Elemental Sulfur
Production: Mod. Claus: 2 stage w/o control (96-
97% removal) (SIC 2911 only)
3-01-032-04 Chemical Manufacturing - Elemental Sulfur
Production: Mod. Claus: 2 stage w/o control (99.9%
removal) (SIC 2911 only)
3-06-001-01 Petroleum Industry - Process heaters: Oil fired
3-06-001-02 Petroleum Industry - Process heaters: Gas fired
3-06-001-03 Petroleum Industry - Process heaters: Oil fired
3-06-001-04 Petroleum Industry - Process heaters: Gas fired
3-06-001-05 Petroleum Industry - Process heaters: Natural gas
fired
3-06-001-06 Petroleum Industry - Process heaters: Process gas
fired
3-06-002-01 Petroleum Industry - Fluid catalytic cracking unit
3-06-003-01 Petroleum Industry - Thermal catalytic cracking unit
3-06-004-01 Petroleum Industry - Blowdown systems: w/ vapor
recovery sys. w/ flaring
3-06-009-02 Petroleum Industry - Hares: Residual oil
3-06-009-03 Petroleum Industry - Hares: Natural gas
3-06-009-04 Petroleum Industry - Hares: Process gas
3-06-009-99 Petroleum Industry - Hares: Other not classified
1-02-004-01 External Combustion - Industrial: Residual oil,
grade 6 oil (SIC 2911 only)
Total
Tons SO. Emitted
41.647
7.175
12,100
92
9,750
4,762
3,368
75,174
57,923
549
13,750
204,647
7.273
15,671
520.445
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Additional emissions are listed under Petroleum Refining in NAPAP for the following SCC
categories.
SCC Description
3-06-001-07 Petroleum Industry - Process heaters: LPG fired
3-06-001-99 Petroleum Industry Process heaters: Other not
classified
3-06-002-02 Petroleum Industry Fluid Catalytic Cracking units:
Catalyst handling system
3-06-004-02 Petroleum Industry Blowdown systems: w/o
control
3-06-005-03 Petroleum Industry - Fugitive emissions: Process
drains and wastewater separators
3-06-005-04 Petroleum Industry - Fugitive emissions: Process
drains and wastewater separators
3-06-006-03 Petroleum Industry - Vacuum distillate column
condenser
3-06-008-01 Petroleum Industry - Fugitive emissions: Pipeline
valves and flanges
3-06-008-05 Petroleum Industry - Fugitive emissions: Misc,
Sampling/ Non-Asphalt Blowing/ Purging/etc.
3-06-010-01 Petroleum Industry - Sludge converter: general
3-06-011-01 Petroleum Industry - Asphalt blowing: general
3-06-012-01 Petroleum Industry - Fluid coking units: general
3-06-014-01 Petroleum Industry - Petroleum coke calcining
3-06-099-02 Petroleum Industry - Incinerators: Residual oil
3-06-099-03 Petroleum Industry - Incinerators: Natural gas
3-06-099-04 Petroleum Industry - Incinerators: Process gas
3-06-888 Petroleum Industry - Fugitive emissions: Not
classified
3-06-999 Petroleum Industry Miscellaneous: Not classified
Total
Tons SO. Emitted
60
7,558
327
66
20
1,060
110
220
12,091
135
91
26,920
12,560
8,927
16,183
4,208
1,739
17.097
109,372
Finally, the distillate oil, residual oil, and natural gas combustion sections specifically
excluded petroleum refining emissions. The emissions excluded from these three combustion
categories add an additional 11,496 tons of SO2 to this section, bringing the total reported NAPAP
emissions for the petroleum industry to 641,313 tons of SO2.
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2.3.6.6 Conclusion
The petroleum refining emission estimates in TRENDS and NAPAP are quite different. The
TRENDS method estimates emissions for six categories for a combined estimate of 830,000 tons of
SO2. NAPAP estimates emissions for many more categories. For the six categories that correspond
to the TRENDS estimate, NAPAP estimates 520,445 tons of SO2. NAPAP has a total estimate of
about 640,000 tons for petroleum refining.
Fluid catalytic cracking dominates the TREND estimate with 326,317 tons. The NAPAP
estimate is significantly lower, 204,647 tons of SO2. It is unclear why the NAPAP emission estimate
is so much lower, the reported NAPAP activity is actually higher than the TRENDS activity (1,585
versus 1,324 x 106 bbl/year fresh feed).
Thermal catalytic cracking activity relies on an annual survey conducted by the Oil & Gas
Journal.25 The NAPAP emission estimate and the NAPAP activity are both an order of magnitude
higher than the TRENDS values. The emissions are 7,273 tons versus 522 tons and the activity is 12
versus 17 x 106 bbl/year fresh feed.
NAPAP reports significantly higher emissions for oil combustion at petroleum refineries.
NAPAP has an emission estimate of 117,512 tons versus the TRENDS estimate of 44,360 tons of
SO2. The emission factor for SCC 1-02-004-01 is listed in TRENDS for process heaters - oil. This
SCC is for grade 6 residual oil burned in external combustion boilers - industrial. The petroleum
refining section also has a general SCC for oil-fired process heaters (3-06-001-03) with the same
emission factor and has added an SCC (3-06-001-11) for large grade 6 oil-fired process heaters
(MOO MMBTU). (This new SCC has a slightly higher emission factor, 159.3S lbs/103 gallons
burned versus 158.6S lbs/103 gallons burned). The TRENDS method should be rewritten to utilize
these SCC codes.
The sulfur content of the oil burned and consequently the emission factor used by TRENDS
for oil-fired process heaters appears to be too low. The majority of the oil reported burned is
actually crude oil (94 percent) and the distillate oil (5.4 percent) is far more significant than the
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residual oil (0.6 percent). Therefore, the use of a residual oil emission factor is not very accurate.
There is no emission factor for combustion of crude oil in process heaters at a petroleum refinery.
Emission factors used in the industrial oil combustion section are 42.3 lbs/103 gallon burned for
distillate oil and 258.5 lbs/103 gallon burned for residual oil. Using the residual oil emission factor,
which appears to be the intent of the TRENDS procedure manual, would result in process heater oil
emissions of:
258.5 * 595,056 / 2000 = 76.911 tons of SO;.
The emission estimates for gas-fired process heaters are also very different in TRENDS and
NAPAP. The NAPAP estimate is 117,237 tons and the TRENDS estimate is 231,106 tons of S0:.
For gas-fired process heater emissions, the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 lists the emission factors as 0.6 lbs/106 ft3 for
natural-gas fired versus 950.0S lbs/106 ft3 for process-gas fired. The emission factor of 253.1 lbs/106
ft3 used in TRENDS is between the emission factors for the two fuels. In TRENDS, the quantity of
process gas burned as a fuel is three times as high as the amount of natural gas burned. It is unclear
why the two fuels are added together in the activity section. An emission factor weighted by
quantity of fuel burned would be 261.2 lbs/106 ft3, which would result in an emission estimate of
238,547 tons of SO2. It is unclear if the natural gas emissions bear calculating since they only
contribute approximately 146 tons of SO2 to the total estimate.
Finally, the emission estimates for sulfur recovery at petroleum refineries is also very
different. The NAPAP inventory reports emissions of 29,117 tons of SO: and the TRENDS estimate
is 202,125 tons of SO2. Errors were discovered in the execution of the TRENDS method (as
discussed in Section 2.3.3). The TRENDS emission estimate should be 172,696 tons of SO,,
however, the numbers are still very dissimilar. Research into the types of sulfur recovery units
employed at petroleum refineries (and their emissions) is warranted.
The data required to determine thermal catalytic cracking versus the fluid catalytic cracking
are no longer available. The thermal catalytic cracking contributes 0.16 percent of the cracking
emissions in the TRENDS estimate but contributes 3.4 percent in the NAPAP inventory. Sicnificant
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effort to identify a replacement source of data for thermal cracking may not be warranted, however,
additional research into why the NAPAP activity rates for thermal catalytic cracking are so different
from TRENDS may be warranted. Effort to determine why the fluid catalytic cracking emission
estimate is so much lower in NAPAP is definitely warranted.
2.3.7 Natural Gas Production
The TRENDS procedure has two components of emissions from the production of natural gas,
combustion and sulfur recovery. The combustion of natural gas during production contributes a
small amount of emissions (441 tons of SO2) as was reported in Section 2.1.5. Emissions from
sulfur recovery are far more significant (163,000 tons) as was reported in Section 2.3.3. This section
presents the results of the combustion and the sulfur recovery emission estimates that TRENDS
publishes as Natural Gas Production. There is no section in the TRENDS procedure manual
specifically for natural gas production, rather the estimate originates in the two sections for natural
gas combustion and sulfur recovery.
The NAPAP estimate is 7,660 tons for combustion of natural gas during production and
59,500 tons of SO2 from sulfur recovery units at natural gas production facilities. In addition,
NAPAP reports 265,000 tons of SO2 from other emission sources in natural gas production, resulting
in a total estimate of 332,000 tons of SO2. The difference between the two estimates is 172,000 tons
of S0: (52 percent).
2.3.7.1 TRENDS Activity
The natural gas consumption for gas pipelines and plants is the sum of pipelines fuel and
lease and plant fuel. These values are obtained from Table 13 "Consumption of Natural Gas" of
Natural Gas Annual, 1985." The value for 1985 for lease and plant fuel is 966,047 x 106 ft3 and the
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1985 value for pipelines fuel is 503,766 x 106 ft3. Therefore the total gas pipelines and plants natural
gas combustion rate is:
966,047 + 503,766 = 1,469,813 x 10b ft3.
The quantity of sulfur recovered by natural gas plants is reported in Table 4 "Recovered
Sulfur Produced and Shipped in the United States" of Minerals Yearbook 1989 "Sulfur.'* The
production from natural gas plants was 2,373,000 metric tons (2,610,000 short tons). The TRENDS
activity spreadsheet erroneously left these activity rates in metric units.
2.3.7.2 TRENDS Emission Factor
The TRENDS emissions factor is 0.6 Ib SCyiO6 ft3 burned for natural gas combustion in the
production of natural gas. This emission factor is consistent with all of the natural gas combustion
emission factors listed in AIRS Facility Subsystem Source Classification Codes and Emission Factor
Listing for Criteria Air Pollutants.1
According to the TRENDS procedure manual, the emission factor for sulfur recovery at
natural gas plants is derived annually from the emissions and throughput reported to AIRS/FS in
SCC 3-01-032-01 through 3-01-032-04. In 1985 the throughput values were reported as 2,388,968
tons of sulfur. In 1985 the emissions were reported as 127,534 tons of SO2. The emission factor is
obtained by dividing the total emissions by the sum of the operating rates. The emission factor for
1985 should be:
127,534 / 2,388,968 * 2000 = 106.8 Ibs/ton of sulfur.
The emission factor reported through the TRENDS spreadsheets for both 1990 and 1991 is
137.5 Ib/ton of sulfur produced.
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2.3.7.3 TRENDS Emissions
TRENDS combustion emissions for natural gas pipelines are calculated as:
0.6 * 1,469,813 / 2000 = 441 tons of SO;.
The TRENDS emission estimates are calculated for sulfur recovery during natural gas
production using the emission factor of 137.5 Ib/ton of sulfur produced and the production rates in
the TRENDS activity spreadsheet. The emissions for natural gas fields are:
2,373,000 * 137.5 / 2000 = 163,143 tons of S0:.
Using the emission factor of 106.8 Ibs/ton of sulfur produced derived by following the
TRENDS procedure manual and the correct activity data would result in the following emission
estimates for natural gas fields.
2,610,000 * 106.8 / 2000 = 139,374 tons of S02
2.3.7.4 NAPAP Activity
The following activity data for natural gas production were reported through the NAPAP
inventory.
SCC Description 106 ft3 Burned
3-10-004-04 Oil and Gas Production - Process Heaters: Natural 12,187
gas
3-10-004-14 Oil and Gas Production - Steam generators: Natural 2.852
gas
Total 15,039
The sulfur recovered at natural gas plants, as reported in the NAPAP inventory, has not been
determined. The following activity data are for the other categories of emissions included in the
NAPAP inventory.
Ill
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SCC Description 106 ft3 Gas
Produced
3-10-002-01 Natural Gas Production: Gas sweeting: Amine 5,061,719
Process
3-10-002-02 Natural Gas Production: Gas stripping operations 747,129
3-10-002-03 Natural Gas Production: Compressors 199,002
3-10-002-04 Natural Gas Production: Wells 254.156
3-10-002-05 Natural Gas Production: Hares 64.826
3-10-002-06 Natural Gas Production: Gas Lift 25.915
3-10-002-99 Natural Gas Production: Other not classified 2,099.517
2.3.7.5 NAPAP Emissions
Emissions are listed for combustion of natural gas during natural gas production, sulfur
recovery, and other NAPAP natural gas production emission sources. The emissions at the 8 digit
SCC level are as follows.
SCC Description Tons SO, Emitted
3-01-032-01 Chemical Manufacturing Elemental Sulfur 14,311
Production: Mod. Claus: 2 stage w/o control (92-
95% removal) (SIC 1311, and 1321 only)
3-01-032-02 Chemical Manufacturing - Elemental Sulfur 12,194
Production: Mod. Claus: 2 stage w/o control (95-
96% removal) (SIC 1300, 1311, and 4922 only)
3-01-032-03 Chemical Manufacturing - Elemental Sulfur 3.299
Production: Mod. Claus: 2 stage w/o control (96-
97% removal) (SIC 1311, and 1321 only)
3-01-032-04 Chemical Manufacturing - Elemental Sulfur 29,694
Production: Mod. Claus: 2 stage w/o control (99.9%
removal) (SIC 1311, and 1321 only)
3-10-002-01 Natural Gas Production: Gas sweeting: Amine 190,241
Process
3-10-002-02 Natural Gas Production: Gas stripping operations 1.427
3-10-002-03 Natural Gas Production: Compressors 31
3-10-002-04 Natural Gas Production: Wells 17
3-10-002-05 Natural Gas Production: Hares 63,055
3-10-002-06 Natural Gas Production: Gas Lift 0
3-10-002-99 Natural Gas Production: Other not classified 10,140
3-10-004-04 Oil and Gas Production Process heaters: Natural 442
gas
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SCC Description Tons SO. Emitted
3-10-004-14 Oil and Gas Production - Steam generators: Natural 18.
gas
Total 324,869
An additional 7,200 tons of SO: were excluded from the natural gas combustion - boilers
estimate because the emissions were reported with an SIC for oil and natural gas production. This
brings the total NAPAP natural gas production emission estimate to 332,069 tons of SO:.
2.3.7.6 Conclusion
The NAPAP and TRENDS estimates for this category are very different. The TRENDS
estimate is made up of two numbers, emissions from combustion of natural gas during natural gas
production and emissions from sulfur recovery units at natural gas plants.
Both NAPAP and TRENDS have small combustion estimates (460 versus 7,660 tons of SO2).
The estimates for sulfur recovery are very different (163,143 versus 59,498 tons of SO2) and no
explanation for the difference is available. As stated earlier, errors were discovered in the TRENDS
estimate and the emissions from sulfur recovery should be 139,374 according to the TRENDS
procedure manual. It is unclear why these two values are so different. Research into the type of
sulfur recovery units that are utilized in natural gas production should be conducted. Finally,
NAPAP reports an additional 264,911 tons of SO, from standard natural gas production processes. It
is unclear why these processes are not accounted for in the TRENDS method.
2.3.8 Iron and Steel
The 1985 TRENDS emission value is 360,000 tons SO2. The 1985 NAPAP emission value is
212,000 for iron and steel manufacturing (including byproduct and beehive coke manufacturing).
The discrepancy between the two inventories is 148,000 tons of S02 (70 percent).
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2.3.8.1 TRENDS Activity
In TRENDS, there are four categories of SO2 emissions for the iron and steel industry: coke,
sintering, open hearth, and roll and finish. Activity for coke is obtained from Survey of Current
Business21 and activity for sintering, open hearth, and roll and finish are obtained from the Minerals
Yearbook 1989 "Iron and Steel."4 All of the activity values derived following the TRENDS
procedure manual matched the TRENDS activity spreadsheet.
Coke
Activity for Coke emissions is the total beehive and oven (byproduct) production figure. The
value is obtained from the U.S. Department of Commerce, Economics and Statistics Administration,
Bureau of Economic Analysis, Survey of Current Business, "Petroleum, Coal, and Products"21
Beehive and Oven Coke (Byproduct) production. For 1985 the value is 28,651,000 tons. Coke
production is also available through Table A5 "Coke and Breeze Production at Coke Plants" of
Quarterly Coal Report1 and the 1985 value was 28,651,000 tons. This is consistent with the value
of 28,700,000 tons b'sted in the TRENDS activity spreadsheet.
Sintering
Activity for Sintering is total pig iron production and is obtained from Table 3 "Materials
Consumed in Blast Furnaces and Pig Iron Produced" of Minerals Yearbook 1989 "Iron and Steel"* or
from the U.S. Department of Commerce, Economics and Statistics Administration, Bureau of
Economic Analysis, Survey of Current Business, "Metals and Manufactures" Pig iron production.28
The numbers from these two references are close (49,963,000 versus 50,446,000 tons). The Minerals
Yearbook 1989 value was found in the Iron and Steel chapter rather than in the Iron Ore chapter.
The value used in TRENDS was from the Survey of Current Business. The TRENDS method
requires dividing the total into three equal portions among the three sintering components (windbox,
discharge, and sinter-fugitive), resulting in a value of 16,815,000 tons for sintering. This is
consistent with the value of 16,800,000 tons listed in the TRENDS activity spreadsheet.
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Open hearth
TRENDS uses a complex process for determining the fraction of steel production in open
hearth furnaces (as opposed to an oxygen furnace or an electric arc furnace). Open hearth is
obtained by multiplying the fraction of scrap and pig iron consumed in steel production (by type of
steelmaking furnace) by the total U.S. raw steel production value.
The data to determine the fraction that is open hearth is obtained from Table 6 "U.S.
Consumption of Scrap and Pig Iron in Steel Production, by Type of Steelmaking Furnace" of
Mineral Yearbook 1989 "Iron and Steel."* The values for basic open hearth scrap and iron were
summed and were 7,148,000 short tons. The values for basic oxygen scrap and iron were summed
and were 59,854,000 short tons. The values for basic electric arc scrap and iron were summed and
were 32,755,000 short tons. The total for the three furnace types, basic oxygen, basic open hearth,
and basic electric arc, was 99,757,000 short tons. Therefore, the fraction that is basic open hearth is
7.2 percent.
The TRENDS procedure is to obtain total raw steel production from the U.S. Department of
Commerce, Economics and Statistics Administration, Bureau of Economic Analysis, Survey of
Current Business, "Metals and Manufactures'™ raw steel production. Total raw steel production is
also available from Table 1 "Salient Iron and Steel Statistics" of Minerals Yearbook 1989 "Iron and
Steel" and the value is 88,259,000 short tons in both references.4
The open hearth activity is then calculated in TRENDS as:
0.07 * 88,259,000 = 6,178,130 tons.
This is consistent with the TRENDS spreadsheet activity value of 6,200,000 tons.
The fraction of production that is basic open hearth is also available in Table 5 "U.S. Steel
Production, By type of Furnace Process" of Minerals Yearbook 1989 "Iron and Steel."* The value
for basic open hearth in 1985 was 7.3 percent. Table 5 also reports that basic open hearth
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production in 1985 was 6,428,000 short tons. Open hearth production is decreasing and only
represents 4.5 percent of 1989 production.
Roll and finish
The activity value for roll and finish operations is total raw steel production. That value was
88,259,000 short tons for 1985 and is consistent with the TRENDS spreadsheet.
2.3.8.2 TRENDS Emission Factors
The emission factors are also divided into the four categories.
Coke
The emission factors for coking cited in the TRENDS method are as follows.
SCC Description Emission Factor Units
3-03-003-02 Primary metal production - 0.02 Ibs/ton of coal
By-Product Coke charged
Manufacturing: Oven charging
3-03-003-03 Primary metal production - 3.3 Ibs/ton of coal
By-Product Coke charged
Manufacturing: Oven pushing
3-03-003-04 Primary metal production - 0.4 Ibs/ton of coal
By-Product Coke charged
Manufacturing: Quenching
3-03-003-06 Primary metal production - 4.0 Ibs/ton of coal
By-Product Coke charged
Manufacturing: Oven
underfiring
3-03-003-08 Primary metal production - 0.1 Ibs/ton of coal
By-Product Coke charged
Manufacturing: Oven/door
leaks
3-03-003-14 Primary metal production - Q. l Ibs/ton of coal
By-Product Coke charged
Manufacturing: Topside leaks
Total 7.92 Ibs/ton of coal
charged
These emission factors match the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 document. There is a 0.0 emission factor for
116
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beehive production-general. An overall emission factor is obtained by adding these factors and
dividing by 0.7 to account for 0.7 tons of coke produced per ton coal consumed. This percentage
coal to coke is substantiated in Table 2 "Statistical Summary of the Coke Industry in the United
States" of Coke and Coal Chemicals in J980.21 The emission factor for coking is:
7.92 / 0.7 = 11.3 Ibs/ton coke produced.
Sintering
The emission factor for sintering was obtained by dividing the 1980 NEDS emissions by the
1980 production. The emission factor is 2.5 Ibs/ton produced.
Open hearth
The emission factor for open hearth was obtained by dividing the 1980 NEDS emissions by
the 1980 production. The emission factor is 1.5 Ibs/ton produced.
Roll and finish
The emission factor for roll and finish is backcalculated from process equipment combustion
emissions burning coke oven gas and residual oil. The coke oven gas discussion was originally
presented in Section 2.1.1.2. The residual oil discussion was originally presented in Section 2.2.1.
The derivation of the coke oven gas component and the residual oil component are repeated below.
Coke oven gas
The TRENDS procedure is to obtain coke oven gas production from Quarterly Coal Report"
however, coke oven gas production is not provided in that report. Table 23 "Coal Consumption by
End-Use Sector" of Quarterly Coal Report provides coal consumption by coke plants in 1985 of
41,056,000 short tons. Figure 15 "Production of Coke and Coal Chemicals" of Coal Data: A
Reference1* indicates that 11,000 ft3 of coke oven gas are produced per ton of metallurgical (coking)
coal. This results in 1985 coke oven gas production of:
41,056,000 * 11,000 / 1,000,000 = 451,616 x 106 ft3.
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The TRENDS method assumes that 40 percent of the coke oven gas is consumed in the iron
and steel industry. Therefore the coke oven gas consumption is:
451,616 * 0.40 = 180,646 x 106 ftj.
The SO: emission factor for coke oven gas is 1,091 lbs/106 ft1 as listed in AIRS.7 Therefore,
coke oven gas emissions are:
180,646 * 1,091 / 2000 = 98,542 tons of SO:.
Residual oil
The quantity of residual oil consumed by steels mills was calculated by taking the quantity in
tons of raw steel produced in 1985 and multiplying by a conversion factor for the value of residual
oil consumed per ton of raw steel produced. The conversion factor used is 7.38 gal/ton raw steel.
The quantity of raw steel produced is obtained from Table 1 "Salient Iron and Steel Statistics" of
Minerals Yearbook 1986 "Iron and Steel". The value for 1985 is 88,259,000 short tons. The
quantity of residual oil consumed by steel mills is calculated as:
88,259,000 * 7.38 gal/ton raw steel = 651,350,000 gallons.
The emission factor for residual oil combustion is cited in the TRENDS procedure manual as
1,595 lbs/103 gal. The emission factor 1,595 is probably a typographical error and should read 159S
lb/103 gallon burned. The TRENDS procedure manual also states that the emission factor used in the
residual oil combustion section should be used. The emission factor cited in Section 2.1.1.2 of this
report is 158.6S lb/103 gallon burned.
The 158.6S lb/103 gallon burned emission factor matches the AIRS Facility Subsystem Source
Classification Codes and Emission Factor Listing for Criteria Air Pollutants^ document. The
average sulfur content of grade 6 fuel oil is obtained from Heating Oils, J9856 Again, this reference
provides averages for each of five regions. The average sulfur contents range from 1.20 to 1.75
118
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percent in a total of 44 samples. The average national figure based on the number of samples is 1.63
percent. The emission factor for residual oil is:
158.6 * 1.63 = 258.5 lb/103 gallons burned.
Residual oil emissions at steel mills are then calculated as:
651,350 * 258.5 / 2000 = 84,187 tons of SO:.
Roll and finish emission factor
The emissions from residual oil combustion are added to coke oven gas emissions and the
quantity of emissions from open hearth furnaces are subtracted from the total to yield:
98,542 + 84,187 - 4,650 = 178,079 tons of SO2.
The emission factor for roll and finish operations is then calculated as:
EF = 178,079 / 88,259,000 * 2,000 = 4.04 Ibs/ton of raw steel.
The overall roll and finish emission factor used in the TRENDS spreadsheets is 3.8 Ibs/ton
raw steel produced for both 1990 and 1991.
2.3.8.3 TRENDS Emissions
TRENDS emissions are calculated using the activity data and emission factors from the
TRENDS spreadsheet for the four categories as follows.
Coking
28,700,000 * 11.3 / 2000 = 162,000 tons SO,
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Open hearth
6,200,000 * 1.5 / 2000 = 4,650 tons of SO2
Sintering
16,800,000 * 2.5 / 2000 = 21,000 tons of SO:
Roll and finish
88,259,000 * 3.8 / 2000 = 168,000 tons of SO:
Total TRENDS
162,000 + 4,650 + 21,000 + 168,000 = 355,650 tons of SO2
2.3.8.4 NAPAP Activity
The NAPAP production for the four processes is broken out below. The activity data were
not high priority elements for all sources in that inventory and are presented for comparison only.
Coking
SCC Description Tons of Coal
Charged
3-03-003-02 Primary Metal Production - By-Product Coke 35,832,171
Manufacturing: Oven charging
3-03-003-03 Primary Metal Production - By-Product Coke 27,288,497
Manufacturing: Oven pushing
3-03-003-04 Primary Metal Production - By-Product Coke 25,181,912
Manufacturing: Quenching
3-03-003-06 Primary Metal Production - By-Product Coke 20,155,913
Manufacturing: Oven underfiring
3-03-003-08 Primary Metal Production By-Product Coke 21,489,908
Manufacturing: Oven/door leaks
3-03-003-14 Primary Metal Production - By-Product Coke 7,764,158
Manufacturing: Topside leaks
3-03-004-01 Primary Metal Production Coke Manufacturing: 405,008
Beehive Process, general
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Open hearth
SCC Description
3-03-009-01 Primary Metal Production - Steel Production: Open
hearth furnace, stack
3-03-009-18 Primary Metal Production - Steel Production:
Charging, open hearth
3-03-009-19 Primary Metal Production - Steel Production:
Tapping, open hearth
Tons Produced
5,746,973
62,002
122,002
Sintering
SCC
3-03-008-01
3-03-008-11
3-03-008-13
3-03-008-17
Roll and finish
SCC
3-03-009-31
3-03-009-33
3-03-009-34
3-03-009-35
Description
Primary Metal Production - Iron Production - Blast
Furnaces: Ore charging
Primary Metal Production - Iron Production -
Sintering: Raw Mat. st'kpiles, coke breeze,
limestone, ore fines
Primary Metal Production - Iron Production -
Sintering: Windbox
Primary Metal Production - Iron Production -
Sintering: Cooler
Description
Primary Metal Production - Steel Production: Hot
rolling
Primary Metal Production - Steel Production:
Reheat furnaces
Primary Metal Production - Steel Production: Heat
treating furnaces: Annealing
Primary Metal Production - Steel Production: Cold
rolling
Tons Iron
Produced
16,178.407
38,736,563
19,693,102
7,139,166
Tons Produced
5,510,147
15,101,751
4,972.078
990.995
2.3.8.5 NAPAP Emissions
The NAPAP emissions for the four processes are:
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Coking
sec
3-03-003-02
3-03-003-03
3-03-003-04
3-03-003-06
3-03-003-08
3-03-003-14
Total
Description
Primary Metal Production - By-Product Coke
Manufacturing: Oven charging
Primary Metal Production By-Product Coke
Manufacturing: Oven pushing
Primary Metal Production By-Product Coke
Manufacturing: Quenching
Primary Metal Production By-Product Coke
Manufacturing: Oven underfiring
Primary Metal Production By-Product Coke
Manufacturing: Oven/door leaks
Primary Metal Production By-Product Coke
Manufacturing: Topside leaks
Tons SO. Emitted
7,305
13,494
3,307
40.816
329
116
65,367
Additional coke manufacturing sources include: coke crushing/screening and handling (41
tons); coal preheater (3,243 tons); gas by-product plant (2,142 tons); coal storage pile (175 tons);
other/not classified (2,062 tons); and beehive process general (1,599 tons) for a total additional
emissions of 9,262 tons of SO2. This brings the total coke manufacture emissions to 74,629
tons SO,.
Open hearth
sec
3-03-009-01
3-03-009-18
3-03-009-19
Total
Sintering
sec
3-03-008-11
Description
Primary Metal Production - Steel Production: Open
hearth furnace, stack
Primary Metal Production - Steel Production:
Charging, open hearth
Primary Metal Production - Steel Production:
Tapping, open hearth
Description
Primary Metal Production - Iron Production -
Sintering: Raw Mat. st'kpiles, coke breeze,
limestone, ore fines
Tons SO. Emitted
1,159
5
5
1,169
Tons SO. Emitted
470
122
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SCC Description Tons SO. Emitted
3-03-008-13 Primary Metal Production - Iron Production 33,756
Sintering: Windbox
3-03-008-17 Primary Metal Production - Iron Production - 280
Sintering: Cooler
Total 34.506
Roll and finish
SCC Description Tons SO. Emitted
3-03-009-31 Primary Metal Production Steel Production: Hot 2,162
rolling
3-03-009-33 Primary Metal Production - Steel Production: 6,484
Reheat furnaces
3-03-009-34 Primary Metal Production - Steel Production: Heat 390
treating furnaces: Annealing
3-03-009-35 Primary Metal Production - Steel Production: Cold 201
rolling
3-04-003-XX Primary Metal Production - Gray Iron Foundries
3-04-007-XX Primary Metal Production - Steel Foundries
Total
Additional iron production sources include: ore charging (552 tons); blast heating stoves
(2,785 tons); cast house (5,374 tons); other not classified (630 tons,) for total additional emissions of
9,341 tons of SO2.
Additional steel production sources include: electric arc furnace (alloy steel) (1,749 tons):
electric arc furnace (carbon steel) (281 tons); soaking pits (9,353 tons); basic oxygen furnace (EOF) -
open hood stack (23 tons); charging and tapping EOF (47 tons); teeming (unleaded steel) and
continuous casting (533 tons); and other not classified (4,316 tons) for total additional emissions of
16,302 tons of SO:.
Finally, several of the combustion categories specifically exclude iron and steel facilities
during the development of their emission estimates. The residual oil section excluded 14,318 tons of
SO,. The natural gas - boilers section excluded 10,044 tons of S02. The coke and coke oven gas
portions of the miscellaneous fuels section specifically excluded iron and steel facilities. The coke
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and coke oven gas emissions are 747 and 11,252 tons of SO2 respectively. In addition, 5,981 tons
from blast furnace gas combustion are added to the total iron and steel estimate.
This brings the total NAPAP emission estimate for iron and steel production to 204,000 tons
of SO,.
2.3.8.6 Conclusion
All four of the iron and steel categories have significantly different emission estimates in
TRENDS and NAPAP. The four categories are discussed separately.
For coking emissions, TRENDS lists the six SCC categories that are used in their estimate.
Using these six SCC categories provides emission estimates of 65,367 tons (NAPAP) versus 162,000
tons (TRENDS). Even if all of the NAPAP coke emissions are counted, the total NAPAP estimate
for coke is only 74,629 tons of SO:. One possible cause for over estimation in the TRENDS
procedure is the inclusion of beehive process coke manufacturing in the activity number. It is not
clear whether the beehive process is still used and SO2 emissions may be much lower. (There is also
a 0.0 as an emission factor in the SCC book.) Another possible disconnect is the application of SO,
control technologies in the NAPAP coke production. Finally, the NAPAP inventory may have
emissions from coke production reported in other iron and steel processing steps.
The TRENDS emission factor for sintering (2.5 Ibs/ton steel produced) was derived from
1980 NEDS statistics and is therefore quite dated. If the 1985 emissions for sintering (SCC 3-03-
008-11 through 20) were divided by one-third of the 1985 production of pig iron (from U.S. Bureau
of Mines) the emission factor would be significantly higher. Using the production value for pig iron
would yield the following emission factor:
(34,506 tons SO2 * 2,000)7(16,800,000 tons sintered pig iron) = 4.11 Ibs SO2/ton pig iron
The NAPAP numbers appear to underestimate the open hearth emissions and the TRENDS
method may overestimate the open hearth emissions. Open hearth is a process that is declining.
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Open hearth emissions are 1,169 tons in NAPAP and 4,650 tons in TRENDS. Using the 1985
NAPAP open hearth emission estimate would change the TRENDS emission factor from 1.5 to 0.38
Ibs/ton produced. The difference could also be due to the application of SO2 control devices in
NAPAP.
The 1985 emission estimates underwent more review than the 1980 estimates and therefore
the 1985 values are more suitable for use to calculate sintering and open hearth emissions in the
TRENDS method. Revising the emission factor based on the 1985 emission estimate would make
the TRENDS and NAPAP emission estimates equivalent for these two categories of emissions.
The TRENDS roll and finish estimate of 168,000 tons of SO, is substantially higher than the
NAPAP estimate of 25,304 tons of SO:. The TRENDS category may be misnamed as it is really a
sum of emissions from combustion of coke oven gas and residual oil. A long and complex
procedure is put forth to calculate the roll and finish emission factor. This procedure, if followed,
did not change the emission factor used from 1985 to 1990 and 1991. Therefore, it is assumed that
the factor has not been recently updated.
The TRENDS procedure assumes that 40 percent of the coke oven gas is burned in iron and
steel facilities. As discussed in the miscellaneous fuels section, this estimate may be too low. Table
12 "Production and Disposal of Coke Oven Gas in the United States by Producing State: 1980" of
Coke and Coal Chemicals in 1980 reports that in 1980 coke gas use was 39 percent used by
producers in heating ovens, 58 percent was for other use by producers, 1.4 percent commercial sales,
and 1.5 percent was wasted.20 The NAPAP activity data are consistent with these statistics indicating
that 99 percent of coke oven gas burned was at iron and steel facilities. In addition, TRENDS uses a
coke oven gas average sulfur value of 1.605 percent. The NAPAP inventory lists an average sulfur
content for coke oven gas of 0.5 percent. Using the lower sulfur content would result in an
emission factor of 340 lb/106 ft3 burned. Assuming 98.6 percent of the coke oven gas is consumed
by the iron and steel industry and that the sulfur content of coke oven gas is much lower, would
result in 75,700 tons of SO2 from the coke oven gas portion of the roll and finish estimate.
Following the procedure, a roll and finish emission factor of 4.04 Ibs/ton was developed versus 3.8
Ibs/ton of raw steel in the TRENDS spreadsheet. Both of these emission factors are too high.
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The reason the TRENDS roll and finish emission factor was calculated so high is based on
the ratio of residual oil used to produce steel. The TRENDS procedures manual uses a factor of
0.00738 x 106 gal/103 ton of raw steel produced (7.38 gal/ton of steel produced). This factor is too
high. Based on the data in Table 3 "Total Inputs of Energy for Heat, Power, and Electricity
Generation by Census Region, Industry Group and Selected Industries, 1985" of Manufacturing
Energy Consumption Survey: Consumption of Energy, 1985* the total residual oil used in blast
furnaces and steel mills was 5,458,000 barrels in 1985. This corresponds to a new factor of:
5,458,000 * 42 / 88,259,000 = 2.597 gal/ton of steel.
Using the new ratio or residual oil burned/ton of raw steel produced results in emissions of 11.248
tons of SO2 from the residual oil portion of the roll and finish estimate.
It is unclear why the Survey of Current Business is introduced as a reference in the TRENDS
procedure. The coke production is available through the Quarterly Coal Report, the pig iron and raw
steel production data are available through the Minerals Yearbook "Iron and Steel."
Finally, the TRENDS procedure does not account for any SO2 controls. This is probably the
most significant difference between the TRENDS and NAPAP estimates.
2.3.9 Cement Manufacturing
The 1985 TRENDS emission value is 620,000 tons S(X The 1985 NAPAP value is 290.700
tons for cement manufacturing. The discrepancy between the two inventories is 329,300 tons of SO.
(113 percent). The discrepancy is due to the difference in the way the fuel emissions are reported.
2.3.9.1 TRENDS Activity
In TRENDS, the cement production is obtained from Table 1 "Salient Cement Statistics" of
Minerals Yearbook 1989 "Cement.'* The value for 1985 was 77,895,000 short tons.
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The activity section of the TRENDS procedure manual does not direct the user to obtain fuel
consumption values, however, the emission factor section implies that the user will need fuel
consumed in cement manufacture. Therefore, fuel consumed in cement manufacture is obtained from
Table 8 "Clinker produced and fuel consumed by the Portland cement industry in the United States
by process" of Minerals Yearbook, 1986 "Cement."4 The 1985 values are as follows.
Description Value
Coal consumed (103 tons) 11,606
Oil consumed (103 barrels) 755
The oil combustion section of the TRENDS procedure document states that two thirds of the
oil consumed by the cement industry is residual oil and the remaining one third is distillate oil
(Sections 2.1.1.1 and 2.1.1.2).
2.3.9.2 TRENDS Emission Factors
The emission factors cited in the TRENDS method account for the sulfur in the mineral
source, the sulfur in coal, the sulfur in residual oil, and the sulfur in distillate oil. TRENDS cites
emission factors that are inconsistent with the AIRS Facility Subsystem Source Classification Codes
and Emission Factor Listing for Criteria Air Pollutants.1 The emission factors cited in the TRENDS
procedure are as follows.
Description Emission Factor Units
Mineral source 10.2 Ibs/ton cement produced
Coal 30.45 Ibs/ton coal burned
Residual Oil 124.5 lbs/103 gal burned
Distillate Oil 112.35 lbs/103 gal burned
The emission factor for cement manufacturing kilns in both the wet and dry process matches
the AIRS Facility Subsystem Source Classification Codes and Emission Factor Listing for Criteria
Air Pollutants.1 The procedures manual states that the emission factors for coal and residual oil
utilize the sulfur value derived in the industrial boilers section. The average sulfur content for
bituminous coal was calculated as 1.4 percent (Section 2.1.4). The average sulfur content cited in
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the Residual Oil (Section 2.1.1.2) is 1.63 percent. The emission factor for distillate oil utilizes an
emission factor of 0.3 percent sulfur.
The TRENDS method states that the uncontrolled emission factor is determined by adding the
emissions and dividing by the total cement production rate. The TRENDS method does not cite
where the fuel consumption values are obtained, however, as stated above, they are available from
Table 8 "Clinker produced and fuel consumed by the Portland cement industry in the United States
by process" of Minerals Yearbook, 1986 "Cement."4 The uncontrolled emission factor would then be
calculated as follows (assuming two-thirds of the oil consumed is residual oil and the remaining one
third is distillate oil).
F10.2 * 77.895 + 30.45 * 11.606 + (125.5 * 0.666 + 112.35 * 0.333) * 31.7101
77,895
= 64.04 Ibs SCX/ton of cement produced
The TRENDS manual then directs the user to estimate the control efficiency using linear
interpolation and the particulate control efficiency. The TRENDS procedure manual states that the
baseline value of 13.75 percent SO2 control corresponds to a 99 percent particulate control and 12
percent SO2 control corresponds to 92 percent particulate control. For this analysis the full 13.75
percent SO2 control will be assumed. This would result in an overall TRENDS emission factor of:
64.04 * (1 - 0.1375) = 55.23 tons of SO^ton of cement produced.
The overall emission factor for cement manufacturing listed in the TRENDS spreadsheets is
15.95 Ibs/ton of cement produced.
2.3.9.3 TRENDS Emissions
Using the emission factor in the TRENDS spreadsheet results in an emission estimate of:
77,895,000 * 15.95 / 2000 = 621,000 tons of SO,.
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2.3.9.4 NAPAP Activity
The NAPAP cement production is reported as 44,124,892 tons of cement produced dry
process and 16,041,286 tons of cement produced wet process.
2.3.9.5 NAPAP Emissions
The NAPAP reported emissions for cement manufacturing are:
sec
3-05-006-06
3-05-007-06
3-90-002-01
3-90-004-02
3-90-005-02
Total
Description
Mineral Products Cement Manufacturing - Dry
Process: Kilns
Mineral Products Cement Manufacturing Wet
Process: Kilns
In-process Fuel Use -
Kiln/Dryer
In-process Fuel Use -
Kiln/Dryer
In-process Fuel Use -
Kiln/Dryer
Bituminous Coal: Cement
Residual Oil: Cement
Distillate Oil: Cement
Tons SO. Emitted
109,150
76.614
77,859
3,574
2.404
269,601
Additional emissions of 6,040 tons are listed in NAPAP for grinding and drying and primary
crushing and other not classified, and an additional 15,012 tons of SO2 were excluded from the
combustion categories of residual oil, distillate oil, bituminous coal, and natural gas, bringing the
total NAPAP emission estimate to 290,653 tons of SO:.
2.3.9.6 Conclusion
Since the TRENDS method was last revised and the NAPAP inventory was completed, the
Portland cement section of AP-42 has been updated. AP-42 currently lists the uncontrolled SO:
emission factor for the dry process as 7.0 Ibs/ton of clinker produced and for the wet process as 6.0
Ibs/ton of clinker produced when coal is the fuel. Coal dominates as the fuel of choice providing 93
percent of kiln fuel consumption. The dry production is overtaking wet production (probably due to
the lower energy requirements of dry). Statistics for manufacture of both (using all types of fuel) are
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available in Minerals Yearbook "Cement."4 Table 8 "Clinker produced and fuel consumed by the
Portland cement industry in the United States by process" of Minerals Yearbook, 1986 "Cement"
provides 1985 statistics is as follows.
Description Value
Wet process (103 tons of clinker 26,066
produced)
Dry process (103 tons of clinker 37,797
produced)
Coal consumed (103 tons) 11,606
Oil consumed (barrels) 755,000
Assuming that the AP-42 emission factors (which are for coal burned) apply, emissions can
be calculated with these statistics as:
(26,066,000 * 6.0 + 37,797,000 * 7.0) / 2,000 = 210,488 tons of SO2.
These are uncontrolled emissions. AP-42 states that the use of a baghouse (for paniculate
control) would result in approximately 75 percent reduction in SO; due to the basic nature of the
paniculate (calcium).
Assuming 75 percent control would result in emissions of:
210,488 * (1 - 0.75) = 52,621 tons of SO2.
The TRENDS estimate apparently double counts the fuel sulfur emissions. The emission
factor that is applied in the TRENDS method is out of date and already accounts for the fuel sulfur.
Double counting the fuel sulfur emissions is a significant error in the TRENDS method.
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2.3.10 Glass Manufacturing
The 1985 TRENDS emission value is 30,000 tons SO2. The 1985 NAPAP value is 23,000
for glass manufacturing. The discrepancy between the two inventories is 7,000 tons of SCX. (30
percent).
2.3.10.1 TRENDS Activity
In TRENDS, the glass production is obtained from the Current Industrial Repons. The SO:
emissions are from three categories: container glass - melting furnace; flat glass melting furnace;
and pressed and blown glass - melting furnace.
For TRENDS the activity is the sum of total production of flat glass, net packed weight of
glass containers, and miscellaneous glass products (pressed and blown glass). Flat glass is obtained
from Table 1A "Summary of Flat Glass Production, Shipments, and Inventories: 1986 and 1985" of
Current Industrial Reports: Flat Glass Summary for 7956.15 The value for 1985 was 3,670,719 tons.
The value for container glass is obtained from Table 5 "Shipments, Production, and Stocks of Glass
Containers: 1985" of Current Industrial Reports: Glass Containers Summary for 1986.IS The value
for 1985 was 22,196,448,000 pounds or 11,098,224 tons. The value for miscellaneous glass products
is an additional 10 percent of the combined flat and container glass production. Total glass
production is then calculated as:
(3,670,719 + 11,098,224) * 1.1 = 16,245,837 tons of glass.
This value matches the TRENDS activity spreadsheet.
2.3.10.2 TRENDS Emission Factors
The emission factors cited in the TRENDS method are as follows.
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SCC Description Emission Factor Units
3-05-014-02 Mineral Products Glass 3.4 Ibs/ton of glass
Manufacture: Container glass produced
Melting furnace
3-05-014-03 Mineral Products Glass 3.0 Ibs/ton of glass
Manufacture: Flat glass - produced
Melting furnace
3-05-014-04 Mineral Products Glass 5.6 Ibs/ton of glass
Manufacture: Pressed and produced
blown glass Melting furnace
These emission factors match the AJRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 document. An overall emission factor of 3.56
Ibs/ton of glass produced is applied to all glass production in the TRENDS method. The 3.56
emission factor is obtained by assuming that the distribution of glass manufacturing is 75 percent
container glass, 15 percent flat glass and 10 percent blown glass.
3.4(.75) + 3.0(.15) + 5.6(.l) = 3.56 Ibs SCyton of glass produced
2.3.10.3 TRENDS Emissions
Using the TRENDS emission factor results in 1985 emissions of:
16,245,837 * 3.56 / 2000 = 28,918 tons of SO2.
2.3.10.4 NAPAP Activity
The reported NAPAP production is as follows.
SCC Description Tons of Glass
Produced
3-05-014-02 Mineral Products - Glass Manufacture: Container 7,219,485
glass - Melting furnace
3-05-014-03 Mineral Products Glass Manufacture: Flat Glass - 2,397,263
Melting furnace
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SCC Description Tons of Glass
Produced
3-05-014-04 Mineral Products - Glass Manufacture: 787.572
Pressed/Blown glass Melting furnace
Total 10,404320
These reported production figures translate into a distribution of 69 percent container glass,
23 percent flat glass, and 8 percent pressed and blown glass. The NAPAP production figures are not
complete enough to be used as a basis for distribution of emissions.
2.3.10.5 NAPAP Emissions
The reported 1985 NAPAP emission are not calculated solely using the SCC emission factors.
The NAPAP emissions for the three SCC codes are as follows.
SCC Description Tons SO. Emitted
3-05-014-02 Mineral Products - Glass Manufacture: Container 11,776
glass - Melting furnace
3-05-014-03 Mineral Products - Glass Manufacture: Flat Glass - 3,616
Melting furnace
3-05-014-04 Mineral Products - Glass Manufacture: 3.110
Pressed/Blown glass - Melting furnace
Total 18,502
Additional emissions of 2,215 tons are listed in NAPAP for the SCC category soda lime and
722 tons of SO2 are included for raw material handling and other not classified. This brings the total
NAPAP emission estimate for glass manufacture to 21,439 tons of SO;. The TRENDS procedure
specifically excludes natural gas combustion in the glass industry from the industrial natural gas
combustion section. As a result the 1,582 tons of SO2 that are reported in NAPAP with industrial
combustion SCCs and glass manufacture SIC's should also be reported in this section. This brings
the NAPAP value to 23,021 tons of S02.
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2.3.10.6 Conclusion
The absolute difference between the TRENDS and NAPAP estimates is fairly small and there
is no evidence that either is in error. However, the TRENDS method may benefit from two
comments.
The purpose of averaging the production numbers and the emission factors in the TRENDS
methodology is unclear. If pressed and blown glass represent 10 percent of the industry (both
production and emission factor derivations assume this) the production and corresponding emission
factors could be applied directly.
(3,670,719 * 3.0 + 11,098,224 * 3.4 + 1,476,894 * 5.6) A2000 = 28,508 tons
Based on the NAPAP production numbers, the 10 percent pressed and blown glass
assumption may be a small overestimate. Because this type of production has the highest SO:
emission factor, it would also cause the TRENDS estimate to be an overestimation.
2.3.11 Lime Manufacturing
The 1985 TRENDS value is 30,000 tons SO2. The 1985 NAPAP value is 32,000 tons for
lime. The discrepancy between the two inventories is 2,000 tons of SO2 (6 percent).
2.3.11.1 TRENDS Activity
In TRENDS, the lime manufacturing estimate is obtained from "Facts and Figures for the
Chemical Industry" published in Chemical & Engineering News.r" In 1985 the U.S primary
production was reported as 15,800,000 tons. Annual lime production is also published in Table 1
"Salient Lime Statistics" of Minerals Yearbook, 1989 "Lime".* The 1985 value was reported as
15,690,000 tons of lime sold or used by producers.
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2.3.11.2 TRENDS Emission Factor
The SO2 emissions are calculated using an emission factor of 3.4 Ibs/ton of lime produced.
This emission factor was developed from the actual S0: emissions reported in NEDS divided by the
NEDS lime production rate as reported in February 1980.
2.3.11.3 TRENDS Emissions
Emissions are then calculated as:
3.4 * 15,800,000 / 2,000 = 26,860 tons SO:.
2.3.11.4 NAPAP Activity
The reported lime manufacturing production in NAPAP for the three main SCCs is as
follows.
SCC Description Tons Lime
Produced
3-05-016-03 Mineral Products - Lime Manufacture: Calcining, 1,020,000
Vertical Kiln
3-05-016-04 Mineral Products - Lime Manufacture: Calcining, 15,479,000
Rotary Kiln
3-05-016-17 Mineral Products - Lime Manufacture: Multiple 135.000
Hearth Calciner
Total 16,634.000
2.3.11.5 NAPAP Emissions
The reported NAPAP S02 emissions for lime manufacture are as follows.
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SCC Description Tons SO. Emitted
3-05-016-03 Mineral Products - Lime Manufacture: Calcining, 3,085
Vertical Kiln
3-05-016-04 Mineral Products Lime Manufacture: Calcining, 18,647
Rotary Kiln
3-05-016-17 Mineral Products Lime Manufacture: Multiple 572
Hearth Calciner
3-90-002-03 In-process Fuel Use: Bituminous Coal, Lime kiln 6,384
3-90-004-03 In-process Fuel Use: In-process fuel: Residual oil, 738
Lime kiln
3-90-005-03 In-process Fuel Use: Distillate Oil, Lime kiln 12.
Total 29,438
In addition, NAPAP reports emissions of 2,263 tons of SO: from the Other Not Classified
SCC for lime production, which brings the NAPAP total to 31,701 tons of SO,.
2.3.11.6 Conclusion
The emission estimates in TRENDS and NAPAP are practically identical. Nevertheless, the
TRENDS emission factor of 3.4 Ibs SO^ton of lime produced may be too low. There are the
following three emission factors in the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 document with units of Ibs SO2 emissions/ton of
lime produced.
SCC Description Emission Factor Units
3-05-016-03 Mineral Products - Lime 8.2 Ibs SO:/ton of lime
Manufacture: Calcining, produced
Vertical kiln
3-05-016-04 Mineral Products - Lime 5.1 Ibs SO2/ton of lime
Manufacture: Calcining, produced
Rotary kiln
3-05-016-17 Mineral Products - Lime 8.2 Ibs SOVton of lime
Manufacture: Multiple Hearth produced
Calciner
The distribution of the three types of lime calcining operations and how they dominate the
industry should be investigated if an average emission factor is going to be used. In addition,
investigation into the use of control devices for the lime manufacturing industry should be
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investigated. As discussed in cement, any paniculate control device for this industry will have very
good SO2 control due to the properties of the lime paniculate being captured.
In the NAPAP inventory, calcining with a rotary kiln is the dominant method. A weighted
emission factor based on the production figures used in the 1985 NAPAP inventory would lead to
the following results. Total NAPAP production is:
1,020,000 + 15,479.000 + 135,000 = 16,634,000 tons.
By percent, the production is distributed across the three categories.
SCC Description Percent
production
3-05-016-03 Mineral Products - Lime Manufacture: Calcining, 6
Vertical kiln
3-05-016-04 Mineral Products - Lime Manufacture: Calcining, 93
Rotary kiln
3-05-016-17 Mineral Products - Lime Manufacture: Multiple 1
Hearth Calciner
Using these production percents to weight an emission factor results in a factor in excess of
the 3.4 TRENDS figure:
8.2(.07) + 5.1 (.93) = 5.3 Ibs/ton of lime produced.
Using this emission factor results in a revised uncontrolled TRENDS emission rate:
15,800,000 * 5.3 / 2000 = 42,000 tons of SO2.
2.3.12 Additional Industrial Process Emission Categories in the NAPAP Inventory
The NAPAP inventory includes additional emission categories beyond the categories covered
by the TRENDS SO: emission estimation method. As stated earlier, the TRENDS method was
developed to reflect changes in emissions from large (> 10,000 tons of SCX/year) source categories.
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Within the chemical manufacturing group of emissions, TRENDS only reports emissions for carbon
black, sulfuric acid and elemental sulfur production. Additional sources within the chemical
manufacturing source categories are listed in Table 2-12.
TABLE 2-12. EMISSIONS FROM CHEMICAL MANUFACTURING
SOURCES INCLUDED IN NAPAP BUT NOT IN
TRENDS
Chemical Manufacturing
Source Category (SIC)
Ammonia Production (2873)
Charcoal Manufacture (2861)
Hydrochloric Acid (2819)
Plastics Production Specific Products (2821)
Synthetic Rubber (Manufacturing Only) (2822)
Ammonium Phosphates (2874)
Sulfur Recovery Plants" (2819)
Inorganic Pigments (2816)
Propylene, Butylene, Ethylene, and Olefm Production (2869)
Nitriles, Acrylonitrile, Adiponitrile Production (2869)
General Processes - Fugitive Leaks (2865, 2869)
Waste Gas Flares
No SCC Descriptor
Other
Total
SCC
3-01-003
3-01-006
3-01-011
3-01-018
3-01-026
3-01-030
3-01-032
3-01-035
3-01-197
3-01-254
3-01-800
3-01-900-99
3-01-999
1985 NAPAP
(tons)a
1.094
4.643
1,540
1.881
4,663
1.554
38,920
5,682
4,184
3,281
1,945
39,620
48,091
4.499
161.597
'The 1985 NAPAP Emissions Inventoiy (version 2): Development of the Annual Data and
Modelers' Tapes, EPA-600/7-89-012a, November 1989.
"Excluding emissions from sulfur recovery at petroleum refineries and oil and natural gas production
plants.
In the mineral products group, TRENDS includes emissions from cement, lime and alass
manufacturing in the SO: emission estimation method. Mineral product source categories included in
the NAPAP SO: inventory but not addressed in the TRENDS estimate are listed in Table 2-13.
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TABLE 2-13. EMISSIONS FROM MINERAL PRODUCTS
SOURCES INCLUDED IN NAPAP BUT NOT
IN TRENDS
Mineral Products
Source Category (SIC)
Asphaltic Concrete (2951)
Brick Manufacture (3251)
Ceramic Clay Manufacture (3261)
Clay & Fly Ash Sintering (3295)
Coal Cleaning & Surface Mining Operations (1111)
Fiberglass Manufacture - Wool & Textile Type Fiber (3229,
3296)
Gypsum Manufacture (3275)
Phosphate Rock (1475)
Stone Quarrying/Processing (1411, 1422, J423, 1429, 1499)
No SCC Descriptor
Other
Total
SCC
3-05-002
3-05-003
3-05-008
3-05-009
3-05-010
3-05-012
3-05-015
3-05-019
3-05-020
3-05-999
1985 NAPAP
(tons)3
1,959
2.193
2.362
1.389
12.481
2,487
9,394
4,651
6,190
5,676
1.918
50,700
The 1985 NAPAP Emissions Inventory (version 2): Development of the Annual Data and
Modelers' Tapes, EPA-600/7-89-012a, November 1989.
Finally, the NAPAP inventory includes additional sources of SO2 emissions from other
industrial processes as listed in Table 2-14.
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TABLE 2-14. EMISSIONS FROM OTHER INDUSTRIAL
PROCESS SOURCES INCLUDED IN NAPAP BUT
NOT IN TRENDS
Source Category (SIC) SCC 1985 NAPAP
(tons)"
Sugar Beet Processing (2063) 3-02-016 1.918
Other Food and Agriculture (0100, 0200, 0700, 2000, 2100, 3-02-XXX 1.449
4200, 4400, and 5100)
Other Pulp & Paper and Wood Products (2400, 2500. 2600, and 3-07-XXX 241
2700)b
Rubber and Miscellaneous Plastics Products (3000, and 7500)
Fabricated Metal products (3400, 5000)
Electrical Equipments (7600)
Machinery, Miscellaneous Leather, and Leather Products
Organic Solvent/Petroleum Product Evaporation
Total
3-08-XXX
3-09-XXX
3-13-XXX
3-12-XXX
3-20-XXX
4-XX-XXX
773
258
463
2
2.374
7,478
"The 1985 NAPAP Emissions Inventory (version 2): Development of the Annual Data and
Modelers' Tapes, EPA-600/7-89-012a, November 1989.
"Does not include sulfate (kraft) pulping, sulfite pulping, or neutral sulfite semichemical
pulping.
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SECTION 3
CONCLUSIONS
This in-depth analysis of the 1985 TRENDS and NAPAP emission estimates for industrial
SO2 sources has led to the following conclusions.
First, the TRENDS method is outdated relative to data that are currently available and the
1985 TRENDS estimates, as currently published, contain numerous mathematical errors. In addition,
the TRENDS method relies on average fuel consumption values for some industrial processes. These
values should be periodically revised and updated.
Second, the TRENDS method does not account for any control measures in the majority of
the industrial SO2 emission estimates.
Third, the NAPAP activity data are not complete enough to provide a reliable estimate of
industrial production. Therefore, the NAPAP activity data do not support the generation of global
emission factors for future use in the TRENDS method.
Fourth, for the majority of source categories, the NAPAP emission estimates appear more
reasonable than the TRENDS estimates.
Due to findings in this report as well as other factors, the TRENDS methodology has been
revised as of 1993; thus, references to TRENDS in this report will no longer be valid for years 1985
and beyond, effective with the 1993 edition of the TRENDS report. The new TRENDS methodology
uses the 1985 NAPAP Emission Inventory as a base. Further changes will be seen in the TRENDS
reports published in 1994 and thereafter. Thus, the reader is cautioned that comments on the EPA
TRENDS report in this document are valid for editions prior to 1993, but are not valid for the
editions for 1993 and thereafter.
The following discussion has been excerpted from the previous section.
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3.1 COMBUSTION SOURCES
The combustion estimates in TRENDS and NAPAP are very similar. This is due in part to
the method utilized by NAPAP to estimate area source emissions. In the NAPAP inventory, the
industrial point source fuel usage is subtracted from national fuel use estimates provided by the
Department of Energy, and emissions from the unaccounted for fuel are allocated to the area source
inventory. This method of determining area source emissions or alternatively of accounting for
emissions from unaccounted for fuel use has several drawbacks. First, many sources do not report
fuel use. Second, the State of Texas does not report any individual fuel use, instead, all industrial
fuel use is reported at the county level to ensure confidentiality. As a result, the initial fuel use
estimate, reported through NAPAP, is believed to be an underestimate. Consequently, the NAPAP
inventory may allocate too much fuel and therefore too many fuel-related emissions to the area
source inventory.
In both the NAPAP and the TRENDS method, the majority of the emissions are from the
combustion of bituminous coal. The average sulfur content that is used in the computation of the
emission factor is extremely important. The TRENDS method has a complicated procedure to
determine an average fuel sulfur content based on statistics for the coal-producing regions. The
complex method has not been performed recently. Additional research into average sulfur contents
for all of the fuels (bituminous coal, anthracite, lignite, residual oil, distillate oil, crude oil and
process gas) is warranted.
3.2 COMBUSTION OF OIL
The TRENDS estimate is 72,480 tons for distillate oil excluding cement plants and petroleum
refineries. The NAPAP estimate for the same category is 107,358 tons of SO2. The NAPAP
estimate includes 55,000 tons of SO2 from area sources. The NAPAP and TRENDS estimates are
much closer if the NAPAP estimate does not include area source emissions.
The TRENDS estimate is 459,510 tons for residual oil excluding cement plants, petroleum
refineries and steel mills. The NAPAP estimate for the same category of emissions is 605,200 tons
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of S02. The NAPAP estimate includes 242,000 tons of S02 from area sources. Again, the two
estimates would be much closer if the area source component of the NAPAP total were not included.
There are large discrepancies in the oil activity data (quantity of reported combusted) used in
the TRENDS method versus the NAPAP inventory for both categories. TRENDS reports 3.426
million gallons and NAPAP reports approximately 2,000 million gallons of distillate oil consumed.
Both values appear to be in error. Table 3 "Total Inputs of Energy for Heat, Power, and Electricity
Generation by Census Region, Industry Group and Selected Industries, 1985" of Manufacturing
Energy Consumption Survey: Consumption of Energy, 1985 reports 31,684,000 bbls consumed
(1,330.7 million gallons). This survey reports an activity that is approximately one-third the value
reported in TRENDS.8
TRENDS reports 3,555 million gallons and NAPAP reports approximately 6,000 million
gallons of residual oil consumed. Table 3 "Total Inputs of Energy for Heat, Power, and Electricity
Generation by Census Region, Industry Group and Selected Industries, 1985" of Manufacturing
Energy Consumption Survey: Consumption of Energy, 1985s reports 80,252,000 bbls consumed
(3,370.6 million gallons).
The activity data used in TRENDS were derived from Fuel Oil and Kerosene Sales.3 If these
data were also used to compute area source activity in NAPAP, this could have resulted in an
overestimation of both residual oil and distillate consumed and resulting emissions reported in
NAPAP through the area source category. It is likely that the NAPAP point source inventory
underreported both distillate and residual oil consumption and that the NAPAP area source inventory
overestimated emissions for these two categories. The discrepancy between the distillate oil
consumption reported though Fuel Oil and Kerosene Sales and Manufacturing Energy Consumption
Survey: Consumption of Energy, 1985 should be investigated.
The development of average sulfur contents for distillate and residual oil is not well
documented in the TRENDS procedure. The sulfur content assumptions have a large impact on the
overall emission factor. Additional effort should be expended to determine reasonable average sulfur
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contents and to determine if industrial oil consumers are electing to use lower sulfur content oil. and
if so, what the overall effects are on emissions from this category.
The NAPAP inventory also includes, as residual oil burned, approximately 932,000 x 10
gallons of crude oil which is burned during crude oil production. This oil use is not counted by
TRENDS and was placed in the residual oil category because no other category existed in NAPAP
3.3 COAL COMBUSTION
As stated above, industrial coal combustion, specifically bituminous coal combustion is by far
the largest single category of industrial SO2 emissions. In the TRENDS method, emissions from
bituminous, subbituminous and lignite are combined in one estimate and coal burned in cement and
lime kilns is subtracted. TRENDS assumes that all of the remaining industrial coal combustion
occurs in boilers. An average emission factor is developed based on an average sulfur content.
The initial bituminous, subbituminous, and lignite activity value, including coal combusted in
lime manufacturing and cement plants, is 75.3 million tons in TRENDS versus 74.5 million tons in
NAPAP. Both of these values are fairly consistent with Table 3 "Total Inputs of Energy for Heat,
Power, and Electricity Generation by Census Region, Industry Group and Selected Industries, 1985"
of Manufacturing Energy Consumption Survey: Consumption of Energy, 1985 which reports 59.195
million tons of coal burned in the industrial sector. The anthracite activity value that is published in
the TRENDS activity spreadsheet could not be replicated. Following the published TRENDS
procedure manual resulted in an activity value of 800,000 tons of anthracite versus 658,800 tons of
anthracite that is currently in the TRENDS activity spreadsheet.
The published TRENDS emission estimate for coal combustion is a sum of the anthracite
value and the bituminous, subbituminous, and lignite value. The published TRENDS value of
1,840,000 tons of SO2 for coal combustion could not be replicated by following the published
TRENDS procedure. The bituminous, subbituminous, and lignite emission estimate in TRENDS
excluding lime and cement emissions, is 1,670,000 tons of SO: versus 1,710,000 tons of SO,
reported in NAPAP The anthracite emission estimate is 11,000 tons of SO: in both TRENDS and
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NAPAP. Again, the NAPAP inventory relies on a total fuel balance to determine the area source
emissions (356,000 tons of SOj) for this category. For this category the addition of the area source
emissions brings the NAPAP and TRENDS estimate closer together. The sulfur contents and
resulting emission factors that were actually used in the 1985 estimate are not documented and
assumptions made about an average sulfur content for the bituminous, subbituminous, and lignite
category may be the reason for the difference.
The four types of coal that constitute the coal combustion category each have slightly
different emission factors. The general emission factors for external combustion in industrial boilers
are as follows.
Anthracite 1-02-001-01,07 39.0S
Bituminous 1-02-002-01,19 39.0S
Subbituminous 1-02-002-21,29 35.0S
Lignite 1-02-003 30.0S
Although there are a couple of smaller emission factors for some types of bituminous coal
combustion (for example fluidized bed), these constitute a very small amount of the coal combustion
activity.
Sulfur contents reported in the NAPAP inventory for these four general types of coal range as
follows.
1 -02-001 -01,07 0.7 to 1.2 percent
1 -02-002-01,19 1.0 to 1.9 percent
1-02-002-21,29 0.4 to 1.5 percent
1-02-003 0.5 to 0.9 percent
Average sulfur contents, based on emissions and reported coal consumption, are as follows.
1-02-001-01,07 0.7 percent
1-02-002-01,19 1.4 percent
1-02-002-21,29 0.7 percent
1-02-003 0.7 percent
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Use of these sulfur contents results in the following average emission factors.
Anthracite 1-02-001-01,07 27.3 Ib/ton burned
Bituminous 1-02-002-01,19 54.6 Ib/ton burned
Subbituminous 1-02-002-21,29 24.5 Ib/ton burned
Lignite 1-02-003 21.0 Ib/ton burned
The TRENDS emission factor of 27.3 for anthracite combustion appears reasonable. The
TRENDS emission factor of 54.3 for bituminous, subbituminous, and lignite is probably an
overestimation.
The TRENDS procedure manual refers to the use of control assumptions as documented in
the EIA-767 data. If control assumptions have been applied (EIA-767 data pertain to utilities and
should not be used to estimate controls on the industrial sector) they are not documented. There are
probably some industrial emission controls that are applied to the NAPAP estimates and are not
reflected in the TRENDS method.
3.4 NATURAL GAS COMBUSTION
The TRENDS method excludes natural gas combustion from cement manufacturing,
petroleum refineries, the iron and steel industry, glass manufacture, and oil and natural gas
production. Once these emissions are excluded, the resulting TRENDS emission estimate is 1.400
tons of SO2. Because TRENDS rounds their estimates to 10,000 tons/year, the emission estimate for
natural gas combustion in boilers is 0.0 tons. The NAPAP emission estimate is 32,800 tons of S0:
excluding natural gas combustion from cement manufacturing, petroleum refineries, the iron and steel
industry, glass manufacture, and oil and natural gas production.
The activity rates for natural gas combustion in boilers reported in the NAPAP inventory are
not consistent with the emission estimates. In addition, the total (unadjusted) natural eas reportedly
consumed is over 715,188 billion ft3 in NAPAP versus 5,901 billion ft3 in TRENDS. This mav be
due in part to the reporting of natural gas consumption as a feedstock versus as a fuel in the NAPAP
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inventory. The TRENDS value is fairly consistent with the 4,512 billion ft3 reported through the
Manufacturing Energy Consumption Survey: Consumption of Energy, 79S5.8
The high consumption of natural gas in the NAPAP inventory may correlate with an
overestimation of natural gas emissions. In the NAPAP inventory, the user had the option of
entering an activity rate and allowing the system to calculate emissions based on an emission factor.
If the user incorrectly coded the activity for natural gas combustion (usually through a
misunderstanding of the appropriate units) and allowed the system to estimate the emissions, the
emissions would be overestimated.
Conversion factors are used to correlate natural gas combustion with both the iron and steel
industry and the glass manufacturing industry. These factors are suppose to be periodically updated
based on information available through the Department of Energy. The value for the steel industry
that is currently used is 4.25 million ft3 of natural gas/103 tons of raw steel. The value for the iron
and steel industry can be updated with information provided in Table 3 "Total Inputs of Energy for
Heat, Power, and Electricity Generation by Census Region, Industry Group, and Selected Industries,
1985" of Manufacturing Energy Consumption Survey: Consumption of Energy, 1985* Natural gas
consumed by blast furnaces and steel mills was 400 billion cubic feet (TRENDS calculated 375
billion cubic feet for raw steel). Based on a 1985 raw steel production of 88,259,000, a revised
factor for iron and steel would be:
400,000 / 88,259 = 4.53 106 ft3/103 ton raw steel.
The value for glass cannot be recalculated at this time because the reference cited combines
stone, clay, and glass products.
3.5 MISCELLANEOUS FUELS
The TRENDS method includes four categories of fuel in the industrial SO2 miscellaneous
fuels category. The emissions from the four categories are published together as one value of 80.000
tons of SO2. Several apparent errors were discovered in the TRENDS method. Correcting the errors
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would result in a revised TRENDS estimate of 30,000 tons of SO2 for miscellaneous fuels. The four
fuels are coke, coke oven gas, kerosene, and liquified petroleum gas (LPG) and are discussed
separately below.
3.5.1 Coke
The coke emissions are 11,300 tons of SO: in NAPAP and 36,000 tons of SO: in TRENDS.
There are several problems in the TRENDS activity data. The activity value in the TRENDS
spreadsheet could not be reproduced by following the procedure. TRENDS lists 1,343,000 tons in
the activity spreadsheet: following .the TRENDS procedure resulted in a value of 1,621,000 tons.
The Manufacturing Energy Consumption Survey: Consumption of Energy, 1985* lists 1,952,000 tons
of coke and breeze for industries other than blast furnaces and steel mills. Therefore, the activity
value for coke combustion is probably too low in the TRENDS procedure. Also, it is unclear why
the TRENDS procedure includes petroleum coke delivered to electric utilities in the industrial coke
activity value.
The coke combustion emission factor used in the TRENDS method probably overestimates
the emissions from this category. TRENDS uses an emission factor of 30.0 Ib/ton burned. The
AIRS Facility Subsystem SCC and Emission Factor Listing for Criteria Pollutants7 has an emission
factor of 39.0S Ib/ton burned. The NAPAP inventory lists an average coke sulfur content of 0.7
percent which results in an overall emission factor of 27.3 Ib/ton burned.
A revised emission estimate using the smaller emission factor and the coke consumption
value derived following the published TRENDS procedure would result in a TRENDS coke
combustion emission estimate of 22,000 tons of SO..
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3.5.2 Coke Oven Gas
The coke oven gas emissions are 2,700 tons of SO2 in NAPAP and 43,300 tons of SO; in
TRENDS. It appears as though TRENDS overestimates SO2 emissions for combustion of coke oven
gas outside the iron and steel industry.
TRENDS assumes 18.8 percent of the coke oven gas produced is burned in boilers outside the
iron and steel industry. The 18.8 percent is not documented. In addition, the TRENDS iron and
steel section assumes that 40 percent of coke oven gas is used in the iron and steel process
equipment (see Roll and Finish subsection of iron and steel). The TRENDS procedure apparently
does not account for the remaining 40 percent of coke oven gas produced. Table 12 "Production and
Disposal of Coke Oven Gas in the United States by Producing State: 1980" of Coke and Coal
Chemicals in 798020 reports that in 1980 coke gas use was 39 percent used by producers in heating
ovens, 58 percent was for other use by producers, 1.4 percent commercial sales, and 1.5 percent was
wasted.
TRENDS lists a coke oven gas average sulfur value of 1.605 percent. The NAPAP inventory
lists an average sulfur content for coke oven gas of 0.5 percent Using a factor of 1.4 percent of
coke oven gas bumed in industrial boilers outside the iron and steel industry and using the NAPAP
average sulfur content results in emissions of:
451,616 * 0.014 * 680 * 0.5 / 2000 = 1,075 tons of SO2.
Two issues in the TRENDS method need to be addressed. First, the amount of coke oven gas
consumed outside of the iron and steel industry must be examined. Second, a reasonable sulfur
content for coke oven gas should be determined.
3.5.3 Kerosene
The kerosene emissions are 421 tons of S02 in NAPAP and 2,491 tons of SO2 in TRENDS.
The TRENDS method overestimates kerosene emissions. The emission factor used in the TRENDS
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procedure to estimate kerosene emissions is actually an emission factor for distillate oil. The
emission factor cited is 10.77 lb/103 gallon burned. Using a kerosene emission factor of 6.2 lb/10
gallon burned results in emissions of:
462,630 * 6.2 / 2000 = 1,434 tons of SO2.
3.5.4 LPG
The LPG emissions are 52 tons in NAPAP and 109 tons in TRENDS. Both values are
insignificant. Following the TRENDS procedure manual did not result in the same activity value for
LPG combustion as is published in the TRENDS activity spreadsheet. The LPG activity value used
in the 1985 TRENDS estimate is higher (1;979 million gallons versus 1,116 million gallons) than the
value reported through the Manufacturing Energy Consumption Survey: Consumption of Energy,
79S5.8 Using the value reported through the survey results in emissions of:
1,116,000 * 86.5 * 0.0013 / 2000 = 63 tons of SO2.
The TRENDS procedure for determining LPG combustion activity is difficult to understand.
A preferred approach may be to hold the value constant and update it every three years with a new
Manufacturing Energy Consumption Survey.
3.6 WOOD
The TRENDS emission estimate for wood combustion is 10,000 tons of SO,. The NAPAP
estimate is 41,700 tons of SO2. The area source component of the NAPAP estimate is rather
substantial (17,000 tons of SO:). Nearly half of the NAPAP point source emissions are from a
general in-process wood combustion category. The emission factor for this category (3-90-008-89) is
38.0S Ibs/ton burned. NAPAP also reports an average sulfur content of 1.5 percent for the SCC.
The resulting emission factor (57 Ib/ton of wood burned) is substantially higher than the emission
factor used in TRENDS and the rest of the NAPAP categories (0.15 Ib/ton burned). As a result this
SCC category is responsible for a disproportionate share of the NAPAP wood combustion point
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source emissions. Due to the high emissions for this one point source category and the high area
source estimate, the NAPAP inventory probably overestimates the wood combustion emissions.
Following the TRENDS procedure did not recreate the activity value that was used in the
calculation of the 1985 emission estimate for wood combustion. However, once the emission
estimate is rounded to the nearest 10,000 tons, the difference is insubstantial.
3.7 NON-FERROUS SMELTING SOURCES
Non-ferrous smelting emissions are an important component of industrial SO2 emissions
because sulfur is present in the ores. Consequently, sulfur recovery is a imponant component of the
emission estimate. The TRENDS method determines sulfur recovery through statistics reported
through the Minerals Yearbook. The values cited in the reference (501,5000 tons of SO2 recovered
as H2SO4) were apparently not used in the development of the published 1985 TRENDS emission
estimate (327,900 tons of SO2 recovered as H2SO4).
The TRENDS method includes emission estimates for primary copper, primary lead, primary
zinc, primary aluminum, and secondary lead. The primary copper estimates are obtained on a point
by point basis from the remaining domestic primary copper smelters. As a result, the TRENDS and
NAPAP estimate are consistent for primary copper smelters.
The primary lead and primary zinc estimates are combined and reported as one value.
Following the TRENDS procedure did not recreate the published primary lead and primary zinc
emission estimate. The TRENDS method appears to overestimate the emissions from primary lead,
primary zinc, primary aluminum and secondary lead.
3.7.1 Primary Zinc
The TRENDS published estimate for primary zinc production is combined with the primary
lead estimate and the published total of 240,000 tons of SO2 from both industries could not be
recreated. This discussion is based on the estimate for primary zinc that was developed following
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the TRENDS procedure. The NAPAP and TRENDS estimates for emissions from primary zinc
production are very different. NAPAP reported emissions of 7,642 tons of SO2 and the TRENDS
method resulted in an emission estimate of 93,864 tons of SO2. As stated above, the value used for
sulfur recovered as H:SO4 apparently was in error and this error could account for the inability to
recreate the published TRENDS value.
The TRENDS method only accounts for emissions from multiple hearth roasters. In addition.
TRENDS assumes all roasting is done in a multiple hearth roaster. Two additional SCCs for roasting
exist, flash roaster (3-03-030-07) and fluid bed roaster (3-03-030-08). Both have a smaller emission
factor (404.4 and 223.5 Ibs/ton of concentrated ore processed respectively) than the multiple hearth
roaster (1100 Ibs/ton of concentrated ore processed).
The NAPAP inventory did not report the majority of emissions through the multiple hearth
roaster. The NAPAP inventory may have overestimated SO2 emissions from some of the other
processes in zinc production (specifically the sinter strand and the vertical retort/electrothermal
furnace SCC 3-03-030-03,05). The discrepancy in NAPAP where the majority of emissions were not
reported through the roasting process needs to be investigated.
3.7.2 Primary Lead
As mentioned above, the published TRENDS value of 240,000 tons of SO: for primary lead
and zinc could not be recreated. The TRENDS estimate developed following the TRENDS
procedure was 34,500 tons of SO:, which differs markedly from the NAPAP estimate of 9S.775 tons
of SO,.
The TRENDS method for determining primary lead SO: emissions is very complex and
appears to be outdated relative to the data that are currently provided in the Minerals Yearbook,
I989.4 The TRENDS method has four steps to determine lead processing. After folio win 2 the four
steps, the result was a lead processing value of 975,378 short tons, which did not match the value of
759,300 tons in the TRENDS activity spreadsheet. After analyzing the four steps that currently
comprise the TRENDS emission estimation procedure for primary lead, it appears that the final
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number is a simple sum of the emissions reported through NEDS (now AFS) and the sulfur
recovered as sulfuric acid. The recovered sulfur is then subtracted from the emission estimate.
Therefore there should be complete agreement between NAPAP and TRENDS for this category. If
the product of the TRENDS method is intended to be different from the simple sum, there are errors
in the TRENDS procedure manual that need to be addressed.
The NAPAP activity for this category is fairly close to the activity published in the Minerals
Yearbook.* The Minerals Yearbook cites a 1985 production of 543,403 short tons. TRENDS
assumes that there is a 2:1 ratio of concentrated ore processed to lead produced. NAPAP reports
1,006,182 tons of concentrated ore processed in the blast furnace, which would correspond to a lead
production rate of 503,000 tons of lead.
3.7.3 Primary Aluminum
The TRENDS estimate is 70,000 tons of SO: from primary aluminum smelters, the NAPAP
estimate is 58,400 tons of SO2. The TRENDS estimate relies on an average emission factor derived
from the 1980 NEDS data for the State of Washington. The validity of the TRENDS emission factor
for primary aluminum could not be confirmed and appears suspect for two reasons. First, it relies on
one set of old emissions (not test) data. Second, there is no documentation of an adjustment due to
controls.
There are three very different emission factors in the AIRS Facility Subsystem Source
Classification Codes and Emission Factor Listing for Criteria Air Pollutants document for primary
aluminum smelting, prebake (57.3 Ibs/ton), HSS (10.0 Ibs/ton), and VSS (17.0 Ibs/ton).7 An
investigation into the distribution of the three types of electro-reduction processes, their controls and
how they dominate the primary aluminum industry should be undertaken to develop an appropriately
weighted emission factor. The 1985 NAPAP production estimates provide the following distribution
between the three process types: prebake (77.2 percent of production), HSS (7.9 percent of
production), and VSS (14.8 percent of production). Using this weighing would result in an emission
factor of 47.5 Ibs/ton (versus the current TRENDS emission factor of 36.85 Ibs/ton). If the 1985
NAPAP primary aluminum emission estimate is used to develop a revised emission factor, an overall
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factor of 19.8 Ibs/ton Al produced results. The absolute factor is lower presumably because NAPAP
accounts for the effect of S02 controls.
In the NAPAP inventory, only 38,063 tons of SO2 are attributable to the three processes
covered by the TRENDS method. Of the processes that are not included in TRENDS, aluminum
hydroxide calcining is the most important. TRENDS includes the aluminum hydroxide calcining
process in the estimation of TSP and PM-10 emissions but not in the SO2 estimate.
3.7.4 Secondary Lead
The TRENDS estimate for secondary lead smelters is 30,000 tons of SO2 compared to 20,700
tons of SO2 reported in the NAPAP inventory. The TRENDS estimate has a slight error in that the
activity value for the blast furnace was not converted to english units. This will not make a
significant difference in the published TRENDS estimate, because the values that are published are
rounded to the nearest 10,000 tons. The TRENDS estimate does not account for SO2 controls such
as baghouses and wet scrubbers.
There is a new SCC, with an SO2 emission factor of 144.0S Ibs SCyiO3 gallons burned, for
this category. The SCC is 3-04-004-07 for pot furnace heater burning distillate oil. This SCC is not
in the TRENDS method and not in the NAPAP inventory.
3.7.5 Other Non-ferrous Emissions Reported in NAPAP
Additional emissions of 41,511 tons of SO2 are reported for other non-ferrous emission
categories in the NAPAP inventory. The largest source categories include ferroalloy manufacture,
furnace electrode manufacture, secondary aluminum and secondary zinc. Of these categories only
the ferroalloy source category has emissions of more than 10,000 tons of SO2 in 1985.
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3.8 OTHER INDUSTRIAL PROCESS EMISSION SOURCES
Significant differences exist in the 1985 TRENDS and NAPAP SO2 emission estimates for
other industrial process emissions. In general, the TRENDS estimates depend on national production
figures developed by the Department of Energy and the Department of Commerce and an emission
factor. The emission factor often represents the largest sources of emissions within the category. To
compare the NAPAP and TRENDS estimate, the entire NAPAP estimate for the category is used.
This would include in-process fuel, fugitive emissions, and processes that are not specifically cited in
the TRENDS method.
The TRENDS method, with very few exceptions, does not include effects of air pollution
control devices unless the effects are inherent in the process (e.g., sulfur recovery) or in the emission
factor. The TRENDS estimates for most categories are significantly higher than the corresponding
NAPAP estimates. A major exception to this statement is the category Oil and Natural Gas
Production.
The NAPAP inventory includes many additional source categories that are not included in the
TRENDS industrial SO2 emission estimation method. The TRENDS method includes only three
categories in the chemical manufacturing group; sulfur, sulfuric acid, and carbon black. The NAPAP
inventory includes ten additional chemical manufacturing source categories with combined additional
emissions of 127,000 tons of SO2. The TRENDS method includes three categories in the mineral
products manufacturing group; cement, glass, and lime. The NAPAP inventory includes nine
additional mineral products manufacturing source categories with combined additional emissions of
50,800 tons of S0:.
3.8.1 Kraft Pulp Production
The pubb'shed TRENDS value for pulp and paper production is 250,000 tons of SO2 and is
probably an overestimate. The NAPAP value is 130,400 tons of SO2.
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The TRENDS method apparently used an emission factor of 11.3 Ibs/ton of air-dry
unbleached pulp to calculate kraft emissions, when a more appropriate value would have been
approximately 7 Ibs/ton of air-dry unbleached pulp. It is unclear how the 11.3 emission factor was
derived since it is significantly higher (nearly 50 percent) than one calculated following the TRENDS
procedure. Based solely on the discrepancy, TRENDS emissions may be overstated by nearly 70,000
tons. Also, TRENDS does not account for the effect of any controls. These two issues could result
in an overesdmation of SO: emissions from wood pulping processes.
The TRENDS procedure does not include a third type of paper pulping process, semi-
chemical. Activity data for semi-chemical pulping are available and emission factors exist in
AP-42.19 Published statistics indicate that semi-chemical production has recently overtaken sulfite
(3.9 x 106 vs. 1.6 x 106 tons) production. If the semi-chemical production is increasing with fewer
associated SO2 emissions, this industry trend should be reflected in the emission estimates.
3.8.2 Carbon Black Manufacture
The carbon black production emission estimates are 28,031 tons of SO2 in NAPAP versus
14,585 tons of SO2 in TRENDS. The TRENDS method appears to underestimate the emissions from
carbon black manufacture.
The total NAPAP production for the oil furnace of 1,013,232 is very similar to the value
TRENDS references (90 percent of total production) 1,156,500. The NAPAP value for the gas
furnace 98,179 is less similar to the value TRENDS references (10 percent of total production)
128,500 tons.
Two questionable items need to be addressed regarding the NAPAP emission estimates and
the TRENDS emission factor. The NAPAP emission estimates by SCC show only a minority of
emissions from the oil furnace (3,958 out of 28,031 tons), although logically this would be the
source of most emissions. However, the pellet dryer combustion furnace (with emissions of 15 183
tons) is, in essence, a thermal incinerator and emissions associated with the furnace itself are emitted
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here. It is likely that engineers coding the NAPAP inventory indicated the vents as discrete emission
points in addition to the oil furnace emission source.
Second, the TRENDS emission factor appears to be too small. The TRENDS procedure
initially uses a fairly high emission factor of 50 Ibs/ton for the flare from an oil furnace process (this
emission factor is supported by AP-42). If a CO boiler and incinerator exist, primarily to control CO
emissions, the AP-42 SO: emission factor drops to 35.2 Ibs/ton. The TRENDS number is 22.7
Ibs/ton, and is unlikely that the emission factor would drop that low, even if all sources had a CO
boiler and incinerator.
As noted, the largest source of emissions in NAPAP is for the pellet dryer. There is no
corresponding category in TRENDS for the pellet dryer, although it is likely that emissions have
been accounted for. As stated earlier, there is no NAPAP category- specifically for the flare,
however, the flare actually represents otherwise uncontrolled oil furnace emissions.
The TRENDS documentation probably needs to be modified to ensure that all emission points
and sources are included. Further investigation of the NAPAP value is warranted to determine why
emissions associated with the oil furnace were distributed to other emission points (vents) if possible.
Finally, the assumption that flares represent otherwise uncontrolled emissions could be confirmed by
looking at the control equipment for these sources coded in NAPAP.
3.8.3 Sulfuric Acid
The NAPAP estimate of 217,166 tons of SO: is extremely close to the TRENDS estimate of
215,405 tons of SO2. One concern about this category is the production of H2SO4 from recovered
sulfur. The NSPS does not apply to sulfuric acid production in conjunction with SO2 controls. It is
unclear if the NAPAP data reflect only the chemical companies producing sulfuric acid or if NAPAP
estimates also reflect byproduct H,SO4 production.
There are several minor errors in the development of the published TRENDS estimate. The
errors included use of an incorrect production value for 1984 from which the 1985 emission factor is
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derived. Because the TRENDS estimates are rounded to 10,000 tons of SO2, the error did not make
a significant difference in the published estimate.
This is the only category of industrial SO2 emissions where the TRENDS method addressed
the implementation of NSPS. The NSPS emission factor of 4 Ib SO:/ton of 100 percent sulfuric
acid produced is consistent with the emission factor for sulfuric acid contact process, 99.9 percent
conversion. In the NAPAP inventory, the activity for 99.9 percent conversion dominates the
category. An analysis of the production data provided in Current Industrial Reports, Inorganic
Chemicals22 reveals that production had a low value of 33,233,000 tons of sulfuric acid in 1982 and
a high of 44,336,818 in 1990. Because the NSPS was promulgated in the 1970's, production over
33,233,000 (and at least 25 percent of production) should be at the. NSPS level. The NAPAP data
indicate that approximately 50 percent of 1985 production was at the NSPS level.
3.8.4 Sulfur Recovery Plants
The TRENDS procedure manual has a separate section for estimating SO2 emissions from
sulfur recovery plants. The resulting emission estimates are published in two other categories,
natural gas production and petroleum refining. As a result, it is not possible to directly assess
whether the published emission estimates were successfully recreated although using the emission
estimates does allow the total natural gas production and total petroleum refinery estimates to match
the published values.
Errors were discovered in both the activity data and the emission factors that were used to
calculate the published 1985 estimates. As a result, the published TRENDS emission estimate is too
high. The estimates using the erroneous information are 202,000 tons for petroleum refineries and
163,000 tons for natural gas production. The corresponding NAPAP emission estimates are 29.117
tons for petroleum refineries and 59,498 tons for natural gas production.
The activity data were erroneously left in metric units rather than convened to Enslish units.
The emission factor was not calculated from AIRS data, as the procedure manual indicated but
rather was held constant. Using the revised emission factor (106.8 Ibs/ton of sulfur produced versus
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137.5 Ibs/ton of sulfur produced) and corrected activity data resulted in TRENDS emission estimates
of 172,696 tons for petroleum refineries and 139,374 tons for natural gas production (a decrease of
53,198 tons of SO,).
The emission factors reported in the AIRS Facility Subsystem Source Classification Codes and
Emission Factor Listing for Criteria Air Pollutants1 range from 280 to 4 Ibs/ton 100 percent sulfur
recovered depending on the sulfur removal efficiency. Multiplying the NAPAP sulfur recovery
production values by these emission factors results in a higher NAPAP total emission estimate of
103,348 tons of SO2. There is a discrepancy between the production values, emission factors, and
reported emissions in the NAPAP inventory. The emissions for 95-96 percent recovery appear to be
underestimated and the emissions for 99.9 percent recovery appear to be overestimated. Therefore
there are probably errors in the NAPAP values, either in the reported production or in the reported
emissions.
Additional research should be expended on this category to try and determine what types of
sulfur recovery plants are in use in petroleum refineries and natural gas production fields. Once
there is additional information, a new appropriately weighted emission factor could be developed for
the TRENDS procedure.
3.8.5 Petroleum Refineries
The petroleum refining emission estimates in TRENDS and NAPAP are quite different. The
TRENDS method estimates emissions for six categories for a combined estimate of 830,000 tons of
S0:. NAPAP estimates emissions for more than six categories of emissions. For the six categories
that correspond to the TRENDS estimate, NAPAP estimates 520,445 tons of SO2, however, NAPAP
has a total estimate of 640,000 tons for petroleum refining.
Fluid catalytic cracking dominates the TRENDS estimate with 326,317 tons. The NAPAP
estimate is significantly lower, 204,647 tons of SO;. It is unclear why the NAPAP emission estimate
is so much lower, the reported NAPAP activity is actually higher than the TRENDS activity (1,585
versus 1,324 million bbl/year fresh feed).
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Thermal catalytic cracking activity relies on an annual survey conducted by the Oil & Gas
Journal™ The NAPAP emission estimate and the NAPAP activity are both an order of magnitude
higher than the TRENDS values, although the emissions are relatively insignificant relative to fluid
catalytic cracking. The emissions are 7,273 tons versus 522 tons and the activity is 12 versus 17
million bbl/year fresh feed.
NAPAP reports significantly higher emissions for oil combustion at petroleum refineries.
NAPAP has an emission estimate of 117,512 tons versus the TRENDS estimate of 44,360 tons of
SO2. The TRENDS procedure should be rewritten to reference the oil fired process heater SCC's.
The sulfur content of the oil burned and consequently the emission factor used by TRENDS for oil-
fired process heaters appears to be too low. The majority of the oil reported burned is actually crude
oil (94 percent) and the distillate oil (5.4 percent) is far more significant than the residual oil (0.6
percent). Therefore the use of a residual oil emission factor is not very accurate. There is no
emission factor for combustion of crude oil in process heaters at a petroleum refinery. Emission
factors used in the industrial oil combustion section are 42.3 lbs/103 gallon burned for distillate oil
and 258.5 lbs/103 gallon burned for residual oil. Using the residual oil emission factor, which
appears to be the intent of the TRENDS procedure manual, would result in 76,911 tons of SO, from
process heaters burning oil.
The emission estimates for gas-fired process heaters are 117,237 tons of SO2 in NAPAP
versus 231,106 tons of SO2 in TRENDS. For gas-fired process heater emissions, the AIRS Facility
Subsystem Source Classification Codes and Emission Factor Listing for Criteria Air Pollutants1
breaks out the emission factors for natural-gas fired 0.6 lbs/106 ft3 versus 950.0S lbs/106 ft3 process-
gas fired. The TRENDS emission factor of 253.1 lbs/106 ft3 appears to be somewhere in between the
emission factors for the two fuels. The quantity of process gas combusted as a fuel is three times as
high as the amount of natural gas combusted. The natural gas emissions are 146 tons of SO,.
Finally, the emission estimates for sulfur recovery at petroleum refineries is also very
different. The NAPAP inventory reports emissions of 29,117 tons of SO2 and the TRENDS estimate
is 202,125 tons of SO:. Errors were discovered in the execution of the TRENDS method (as
discussed in Section 2.3.3) and the TRENDS emission estimate should be 172,696 tons of SO,
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however the numbers are still very dissimilar. Research into the types of sulfur recovery units
employed at petroleum refineries (and their consequent emissions) is warranted.
The data required to determine thermal catalytic cracking versus the fluid catalytic cracking
are no longer available. The thermal catalytic cracking contributes 0.16 percent of the cracking
emissions in the TRENDS estimate but contributes 3.4 percent in the NAPAP inventory. Significant
effort to find a replacement source of data for thermal cracking may not be warranted, however,
additional research into why the NAPAP activity rates for thermal catalytic cracking are so different
from TRENDS may be warranted. Effort to determine why the fluid catalytic cracking estimate is so
much lower in NAPAP is definitely warranted.
3.8.6 Natural Gas Production
The NAPAP and TRENDS estimates for this category are very different. The TRENDS
estimate is made up of two numbers, emissions from combustion of natural gas during natural gas
production and emissions from sulfur recovery units at natural gas plants.
Both NAPAP and TRENDS have small combustion estimates (460 versus 7,660 tons of
The estimates for sulfur recovery are very different (163,143 tons of SO2 in TRENDS versus 59,498
tons of SO2 in NAPAP). As stated earlier, errors were discovered in the TRENDS estimate and the
value should be 139,374 according to the procedure manual. Research into the type of sulfur
recovery units that are utilized in natural gas production should be conducted.
NAPAP reports an additional 264,911 tons of SO2 from standard natural gas production
processes including gas-sweetening amine process, gas stripping operations and flares. It is unclear
why these processes are not accounted for in the TRENDS method.
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3.8.7 Iron and Steel
All four of the iron and steel categories, coke manufacture, sintering, open hearth furnace, and
roll and finish operations, have significantly different emission estimates in TRENDS and NAPAP.
The four categories are discussed separately.
For coking emissions, TRENDS lists the six SCC categories that are used in their estimate.
Using these six SCC categories provides coking emission estimates of 65,367 tons (NAPAP) versus
162,000 tons (TRENDS). Even if all of the NAPAP coke emissions are counted, the total NAPAP
estimate for coke is only 74,629 tons of SO2.
The TRENDS method appears to overestimate coking emissions. One possible cause for over
estimation in the procedure is the inclusion of beehive process coke manufacturing in the activity
number when beehive process coke production may not have any associated SO2 emissions (there is
a 0.0 as an emission factor in the SCC book and the NAPAP emission estimate is 1,599 tons of
SOj). Another possible disconnect is the accounting of SO2 control techniques in the NAPAP
inventory. Finally, the NAPAP inventory may have emissions from coke production reported in
other iron and steel processing steps.
The sintering emission estimate is 21,000 tons of SO2 in TRENDS versus 34,506 tons of S0:
in NAPAP. The open hearth emission estimate is 4,650 tons of SO2 in TRENDS versus 1,169 tons
of SO2 in NAPAP. For both these categories, the TRENDS method utilizes an emission factor that
was derived from 1980 NEDS statistics.
The 1985 NAPAP inventory underwent significantly more review than the 1980 NEDS
estimates. In addition, the 1985 numbers are more current. Therefore the 1985 values are more
suitable for use to calculate sintering and open hearth emissions in the TRENDS method, although
their absolute reliably for this purpose is unclear. Revising the emission factor based on the 1985
NAPAP emission estimate and utilizing the activity data that are available through the Minerals
Yearbook would make the TRENDS and NAPAP emission estimates equivalent for these two
categories of emissions. The overall sintering emission factor would increase from 2.5 Ibs/ton steel
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produced to 4.11 Ibs/ton of pig iron sintered. The overall emission factor for open hearth furnaces
would decrease from 1.5 Ibs/ton produced to 0.4 Ibs/ton produced. These changes in the emission
factors are so drastic that they cast doubt on this method of obtaining an emission factor.
The TRENDS roll and finish emission estimate of 168,000 tons of SO2 is substantially higher
than the NAPAP estimate of 25,304 tons of SO2. The TRENDS category may be misnamed as it is
really a sum of emissions from combustion of coke oven gas and residual oil. Although a long
involved procedure is put forth to calculate the roll and finish emission factor, the factor has not
changed from 1985 though 1991 and therefore the procedure has probably not been used. After
following the procedure, a roll and finish emission factor of 4.04 was developed versus 3.8 Ibs/ton of
raw steel in the current TRENDS spreadsheets. Both of these emission factors are too high.
The reason the TRENDS roll and finish emission factor is so high is based on the ratio of
residual oil used to produce steel. The TRENDS Procedures Manual uses a factor of 7.38 gal/ton of
steel produced. Based on the data in Table 3 "Total Inputs of Energy for Heat, Power, and
Electricity Generation by Census Region, Industry Group and Selected Industries, 1985" of
Manufacturing Energy Consumption Survey: Consumption of Energy, 1985, the total residual oil
used in blast furnaces and steel mills was 5,458,000 barrels in 1985.8 Together, the changes in the
coke oven gas and residual oil emission estimate would decrease the TRENDS roll and finish
estimate from 168,000 tons to 87,000 tons SO2.
3.8.8 Cement Manufacturing
There is a significant difference in the 620,000 tons of SO, estimated in the TRENDS method
versus the 290,700 tons of SO2 estimated in the NAPAP inventory for cement manufacture. The
TRENDS method apparently double counts the fuel sulfur. The AP-42 emission factor of 10.2
Ibs/ton cement produced that was used in the TRENDS method accounts for the fuel sulfur. The
TRENDS method adds coal, residual oil, and distillate oil combustion emission estimates to the
estimate made with the 10.2 Ibs/ton cement produced emission factor. This is a significant error in
the TRENDS method.
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In the time since the TRENDS method was last revised and the NAPAP inventory was
completed, the Portland cement section of AP-42 has been updated. AP-42 currently lists the
uncontrolled SO2 emission factor for the dry process as 7.0 Ibs/ton of clinker produced and for the
wet process as 6.0 Ibs/ton of clinker produced when coal is the fuel. Coal dominates as the fuel of
choice providing 93 percent of kiln fuel consumption. The dry production is overtaking wet
production with a corresponding lower energy requirement per ton of clinker produced.
Statistics for manufacture of both (using all types of fuel) are available in Minerals Yearbook
"Cement".4 Total 1985 production using the wet process was 26,066 10" tons of clinker and using
the dry process was 37,797 103 tons of clinker. Assuming that the AP-42 emission factors (which
are for coal burned) apply, emissions can be calculated as 210,500 tons of SO2. These are
uncontrolled emissions. AP-42 states that the use of a baghouse (for paniculate control) would result
in approximately 75 percent reduction in SO2 due to the basic nature of the paniculate (calcium).
Assuming 75 percent control would result in emissions of 52,600 tons of SO2.
3.8.9 Glass Manufacturing
The TRENDS estimate for glass manufacture is 30,000 tons of SO2 and the NAPAP estimate
is 23,000 tons of SO2. The absolute difference between the TRENDS and NAPAP estimates is fairly
small and there is no evidence that either is in error. However, the TRENDS method may benefit
from two comments.
The purpose of averaging the production numbers and the emission factors in the TRENDS
methodology is unclear. If pressed and blown glass represent 10 percent of the industry (both
production and emission factor derivations assume this) the production and corresponding emission
factors could be applied directly.
Based on the NAPAP production numbers, the 10 percent pressed and blown glass
assumption may be a small overestimate. Because this type of production has the highest SO,
emission factor, it would also skew the TRENDS estimate to an overestimation.
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3.8.10 Lime Manufacturing
The TRENDS estimate for lime manufacture is 30,000 tons of SO, and the NAPAP estimate
is 32,000 tons of SO2. Statistically there is no difference in the emission estimate in TRENDS and
NAPAP. Nevertheless, the TRENDS emission factor of 3.4 Ibs SO2/ton of lime produced may be too
low. There are three emission factors in the AIRS Facility Subsystem Source Classification Codes
and Emission Factor Listing for Criteria Air Pollutants7 document with units of Ibs S02
emissions/ton of lime produced. Calcining in a vertical kiln and multiple hearth calcining both have
an emission factor of 8.2 Ibs SO2/ton of lime produced. Calcining in a rotary kiln has an emission
factor of 5.1 Ibs SO^ton of lime produced. In the NAPAP inventory, calcining with a rotary kiln is
the dominant method 93 percent of production). Calcining in a vertical kiln or in a multiple hearth
calciner is 7 percent of production. Using these production statistics results in a weighted average
emission factor of 5.3 Ibs/ton lime produced. Using this emission factor results in a revised
uncontrolled TRENDS emission estimate of 42,000 tons of SO2.
An investigation into the distribution of the three types of lime calcining operations and how
they dominate the industry should be undertaken if an average emission factor is going to be used.
In addition, an investigation into the use of control devices for the lime manufacturing industry
should be undertaken. As discussed in cement, any paniculate control device for this industry will
have very good SO2 control due to the properties of the lime paniculate being captured.
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SECTION 4
REFERENCES
1. Saeger, M. et al. The 1985 NAPAP Emissions Inventory (Version 2): Development of
the Annual Data and Modelers1 Tapes. EPA-600/7-89-012a (NTIS PB91-119669).
U.S. Environmental Protection Agency, Air and Energy Engineering Research
Laboratory. Research Triangle Park, NC. November 1989. pages 3-32 through 3-34.
2. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards.
National Air Pollutant Emission Estimates, 1900-1991. EPA-454/R-92-013. Research
Triangle Park, NC. October 1992.
3. U.S. Department of Energy, Energy Information Administration. Fuel Oil and
Kerosene Sales 1989. DOE/EIA-0535 (89). Washington, DC. January 1991.
4. U.S. Department of the Interior, Bureau of Mines. Minerals Yearbook 1986. Volume
I: Metals and Minerals. Washington, DC. 1988.
5. U.S. Department of Energy, Energy Information Administration. Petroleum Supply
Annual 1985. Volume 1. DOE/EIA-0340 (85)/l. Washington, DC. May 1986.
6. Shelton, E.M., and C.L. Dickson, Heating Oils, 1985, NIPER-141 PPS 85/4, Prepared
by the National Institute for Petroleum and Energy Research, Bartlesville, OK. July
1985.
7. U.S. Environmental Protection Agency, National Air Data Branch. AIRS Facility
Subsystem Source Classification Codes and Emission Factor Listing for Criteria Air
Pollutants. EPA-450/4-90-003 (NTIS PB90-207242). Research Triangle Park, NC.
March 1990.
8. U.S. Department of Energy, Energy Information Administration Manufacturing Energy
Consumption Survey: Consumption of Energy, 1985. DOE/EIA-0512 (85).
Washington, DC. November 1988.
9. U.S. Department of Energy, Energy Information Administration. Cost and Quality of
Fuels for Electric Utility Plants 1985. DOE/EIA-0191(85). Washington DC July
1986.
10. U.S. Department of Energy, Energy Information Administration. Coal Distribution
January-December 1985. DOE/EIA-0125 (85/4Q). Washington, DC. April 1986.
11. U.S. Department of Energy, Energy Information Administration. Quarterly Coal
Report, October-December 1985. DOE/EIA-0121 (85/4Q). Washington, DC. April
1986.
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12. Facts and Figures for the Chemical Industry, Chemical and Engineering News, Volume
64, Number 23, Washington, DC. June 9, 1986.
13. U.S. Department of Energy, Energy Information Administration. Natural Gas Annual
1985. DOE/EIA-0131 (85). Washington, DC. November 1986.
14. U.S. Department of Commerce, Bureau of the Census. Current Industrial Reports:
Flat Glass Summary for 1986. MO32A(86)-5. Washington, DC. June 1987.
15. U.S. Department of Commerce, Bureau of the Census. Current Industrial Reports:
Glass Containers Summary for 1986. M32G(86)-13. Washington, DC. May 1987.
16. U.S. Department of Energy, Energy Information Administration. Manufacturing
Energy Consumption Survey: Consumption of Energy, 1988. DOE/EIA-0512(85).
Washington, DC. November 1988.
17. U.S. Department of Energy, Energy Information Administration. Electric Power
Annual 1985. DOE/EIA-0348(85). Washington, DC. July 1986.
18. U.S. Department of Energy, Energy Information Administration. Coal Data: A
Reference. DOE/EIA-0064(87). Washington, DC. May 1989.
19. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards.
Compilation of Air Pollutant Emission Factors. Volume I: Stationary Point and Area
Sources. Fourth Edition. AP-42 (GPO 055-000-00251-7). Research Triangle Park.
NC. September 1985.
20. U.S. Department of Energy, Energy Information Administration. Coke and Coal
Chemicals in 1980. DOE/EIA 0120 (80). Washington, DC. November 1981.
21. U.S. Department of Energy, Energy Information Administration. Estimates of U.S.
Biofuels Consumption 1990. DOE/EIA-0548(90). Washington, DC. October 1991.
22. U.S. Department of Commerce, Bureau of the Census. Current Industrial Reports:
Pulp, Paper, and Board 1986. MA26A(86)-1. Washington, DC. September 1987.
23. U.S. Department of Commerce, Bureau of the Census. Current Industrial Reports:
Lumber Production and Mill Stocks 1991. MA24T(91)-1. Washington, DC.
September 1992.
24. U.S. Department of Commerce, Bureau of the Census. Current Industrial Reports:
Inorganic Chemicals 1986. MA28A(86)-1. Washington, DC. October 1987.
25. Annual Refining Survey. Oil & Gas Journal. Volume 84. March 24, 1986
167
-------
26. Symes, R., Refinery Operating Ratio, Crude Petroleum. Communication from United
States Department of Commerce, Economics and Statistics Administration, Bureau of
Economic Analysis, Washington D.C. April 27, 1993.
27. Symes, R., Beehive and oven coke (byproduct), production. Communication from
United States Department of Commerce, Economics and Statistics Administration,
Bureau of Economic Analysis. Washington, DC. April 23, 1993.
28. Becker, B. Pig iron production. Communication from United States Department of
Commerce, Economics and Statistics Administration, Bureau of Economics Analysis,
Washington, DC. April 29, 1993.
29. Becker, B. Raw steel production. Communication from United States Department of
Commerce, Economics and Statistics Administration, Bureau of Economic Analysis,
Washington, DC. April 29, 1993.
168
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APPENDIX A
EPA TRENDS PROCEDURE FOR INDUSTRIAL S02 EMISSIONS
The TRENDS Procedures Document was developed to support the TRENDS emission
estimation method using spreadsheets to perform the calculations. As a result, the TRENDS
Procedure as published, is somewhat disjointed and the user needs to jump around the document to
obtain the values that are needed. During the development of the annual TRENDS estimate, the
document works because once a number is developed, the spreadsheet automatically uses the number.
The following procedure was developed by compiling the appropriate sections into a
sequential series of steps, thus avoiding jumping around the document. In addition, sections that do
not pertain to the industrial SO2 emission estimates are not included. This would include whole
source categories such as highway vehicles as well as sources within a source category that are not
part of the TRENDS SO2 method, generally due to the emission cutoff level that was imposed on the
TRENDS procedure (10,000 short tons per year).
The order of the source categories within this document follows the published TRENDS
procedure manual. The procedures described below have not been edited under this effort.
Interpretation of the procedure is described within the body of the report and this section has been
left intact in order to allow the reader to develop a different interpretation if appropriate.
Two spreadsheets accompany the TRENDS procedure manual. One spreadsheet contains the
emission factors for the source categories and is used to calculate current TRENDS estimates. The
second spreadsheet contains historical activity data and is used in the projection of TRENDS
estimates. On occasion, the emission factors reported in the text of the Procedures manual did not
correspond to the emission factors located in the spreadsheets. The emission factors as they appear
in the spreadsheet (in metric units) are included at the end of each section.
Anthracite Coal
Activity
From Coal Distribution, table entitled "Distribution of U.S. Coal by Origin and Consumer,"
obtain the distribution of anthracite from Pennsylvania to industrial less coke plants. State data is
provided.
Emission Factors
Table 1.2-1, AP-42 Fourth Edition, Volume I
SCC SO,
1-02-001-01 39.0 S
1-02-001-04 39.0 S
A-l
-------
Weight the emission factors based on the AIRS/FS AFP650 report (emissions by SCC report).
Fuel totals and actual emissions are reported in this printout. Use an ash content of 11 percent and a
sulfur content of 0.7 percent.
EF from print-out: 24.8 MLbs/tons
Bituminous Coal and Lignite
Activity
Obtain the total national consumption by "other industrial" (not including coke plants) from
the Quarterly Coal Report. From this total, subtract the sum of the following three values:
1. Consumption by cement plants in Mineral Industry Survey, Cement.
2. Consumption by lime plants. Calculated from C&E News. Estimated coal consumption is lime
production, multiplied by 0.1 ton coal/ton lime produced.
Emission Factors
Obtain a weighted average EF from AIRS/FS AFP650, for SCC 102002. AFP650 is used to
obtain amounts of coal burned for each SCC. These are used as weighting factors with the emission
factors obtained from the AIRS/FS SCC listing to calculate the weighted average EF. The value for
SO2 is 38.1(S) Ibs SOJ ton. None of the emission factors need to be changed unless AP-42 changes.
However, ash and sulfur content numbers may change. Therefore it may be necessary to change the
emission factors.
Obtain the average percentage sulfur content from Coal Production (ref. 30) for shipments
from each coal-producing state to other industrial consumers. Use the sulfur content data for the
latest available year. As a first step it is necessary to determine an average sulfur content value for
each coal production district. The reported sulfur contents in ref. 30 are for each state. Reference
30 also contains a description of the coal production districts. This information can be used to match
the states to coal production districts. For those districts that represent only parts of states ref 30
also gives coal production by county for each state, which can be used to estimate the shipments
from each district from component states. Compute a weighted average sulfur content value for each
production district, as necessary. Weight these district averages by the shipments data from each
district to destination contained in the Coal Distribution report. In this case the destination is "other
industrial' consumers.
NOTE: This procedure is quite cumbersome, and thus has not been applied The latest
available data for sulfur content of coal by production district is for 1978 These data have
been used for all TRENDS calculations for 1979-1985. (Assumes sulfur contents of coal
from each production district have not changed since then.) In the future DOE/EIA mav
produce new reports that give information on sulfur content in industrial coal shipment The
reader should make use of any new DOE reports to improve this procedure
A-2
-------
EF from print-out: 49.34 MLbs/tons (1990)
46.85 MLbs/tons (1991)
Residual Oil
Activity
Residual oil and distillate oil source categories can be done together for fuel consumption
only.
Obtain the "adjusted" quantity of residual oil sales for industrial and oil company use from
Fuel Oil and Kerosene Sales 19xx. Subtract the total of the following three statistics:
1. Quantity of oil consumed by cement plants reported in Mineral Industry Survey, Cement.
Assume that 2/3 of the oil reported is residual oil; convert to gallons.
2. Quantity of residual oil consumed by petroleum refineries reported in Petroleum Supply
Annual, table entitled, "Fuel Consumed at Refineries by PAD District." Convert to
gallons.
3. Quantity of residual oil consumed by steel mills. From the Survey of Current Business,
table containing information on Metals and Manufactures, obtain the quantity of raw
steel production in short tons and multiply by 0.00738 x 106 gal/103 ton steel. (This
value should be updated for 1982 and later years based on the 1982 Census of
Manufactures. Fuels and Electric Energy Consumed).
Emission Factors
Table 1.3-1, AP-42 Fourth Edition, Volume I
SCC SO,
1-02-004-01 158.6S
S = 1.82
For SO2, obtain a sulfur content value for No. 6 fuel oil from Heating Oils. An average value
can be interpreted from the graphs presented in this report.
EF from print-out: 261.9 MLbs/10*3 Gal. (1990)
277.2 MLbs/10*3 Gal. (1991)
A-3
-------
Control
S02: From ref. 33c.
NOTE: Ash and sulfur content numbers may change. Therefore, it may be necessary to change the
emission factors
Distillate Oil
Activity
These values were derived simultaneously with residual oil consumption.
Obtain the "adjusted" quantity of distillate oil sales to industrial and to oil companies from
Fuel Oil and Kerosene Sales 19xx. Subtract the total of the following statistics:
1. Quantity of oil consumed by cement plants reported in Mineral Industry Survey. Cement.
Assume that 1/3 of the oil reported is distillate oil. Convert to gallons.
2. Quantity of distillate oil consumed by petroleum refineries reported in Petroleum Supply
Annual, table entitled, "Fuel Consumed at Refineries by PAD District." Convert to
gallons.
Emission Factors
Table 1.3-1, AP-42 Fourth Edition, Volume I
SCC SO,
1-02-005-01 143.6S
1-02-005-04 150.0S
Weight the factors above based on the AIRS/FS AFP650 report (see Table 3.9-1).
For SO:, obtain average sulfur content values for No. 1, No. 2 and No. 4 oils reported in
Heating Oils. Weight these values by the corresponding distribution to industrial reported in Fue.
Oil and Kerosene Sales 19xx. to obtain a weighted average sulfur content value.
EF from print-out: 35.6 MLbs/10*3 Gal. (1990)
35.0 MLbs/10*3 Gal. (1991)
Control
SO2: From ref. 33c.
NOTE: Ash and sulfur content numbers may change. Therefore, it may be necessary to chan°e the
emission factors. c
A-4
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Table 3.9-1. Weighted Average Emission Factors for Industrial Oil Combustion
Boiler Type
Boilers burning No.
2
Boilers burning No.
4
Turbines
1C engines"
Weighted Average
(lbs/1000 gal)
AIRS/FS
Consumption
32758
3640
30193
6536
AP-42 Emission Factors
(lbs/1000 gal)
CO
NOX
SO2
voc
*
* Use the nonmethane VOC EF.
** Internal combustion engines.
Natural Gas
Activity
Boilers: Obtain the total industrial consumption figure for natural gas from Natural Gas Annual.
Subtract from this figure the sum of the following:
1. Total natural gas consumption by cement plants obtained from Mineral Industry Survey. Cement.
2. Total natural gas consumption by petroleum refineries obtained from Petroleum Supply Annual,
(Table: Fuels Consumed at Refineries).
3. Total natural gas consumption by iron and steel industry. Obtain the raw steel production
from Mineral Industry Survey, Iron and Steel. Multiply the production figure by 4.25
x 106 cu. ft. natural gas/1000 tons steel*
4. Total natural gas consumption by glass manufacture industry. Take the total production
as computed for glass production from Table 3.15.35, "Particulate Emissions from the
Mineral Products Industry." Multiply this figure by 10.8 x 106 cu. ft. natural gas/1000
tons glass produced.*
"This value should be updated for 1982 and later years based on data from the 1982 Census of
Manufactures and the Annual Survey of Manufactures. Fuel and Electricity Energy Consumed.
A-5
-------
For glass activity data, see Glass below.
Glass: Table 8.13-1, AP-42 Fourth Edition
IbsATon
SCC Description JSP PM-10
3-05-014-02 Container Glass: Melting Furnace 1.4 1.32
3-05-014-03 Flat Glass: Melting Furnace 2.0 1.9
3-05-014-04 Pressed & Blown: Melting Furnace 17.4 16.5
Weight the EF's shown above by the factors shown in Table 3.15-4 [see Glass below].
Gas Pipelines and Plants: Obtain the total natural gas consumption for lease and plant fuel plus
pipeline fuel from Natural Gas Annual.
Emission Factors
Table 1.4-1, AP-42 Fourth Edition, Volume I
SCC SO,
1-02-006-02 .6
EF from print-out: Boilers 0.5 MLbs/10*6 CF
Gas Pipelines & Plants 0.5 MLbs/10*6 CF
Control
SO,: From ref. 33c.
NOTE: Ash and sulfur content numbers may change. Therefore, it may be necessary to change the
emission factors.
Miscellaneous Fuel
Activity
Coke: The objective is to estimate coke consumption, in tons, outside the iron and steel industry.
From the Quarterly Coal Report, obtain the following data:
1. Total breeze production at coke plants. Assume 24 percent is sold for use as boiler fuel.
Multiply total breeze production by 0.24.
2. Coke sales to "other industrial plants;" if data for foundries and other industrial plants are
combined, assume that 49 percent of the total is for other industrial plants.
Add 1 and 2 to obtain total coke produced from coal. Alternatively, if 1 and 2 are not
available, assume 5.75 percent of total coke production represents coke consumption outside the iron
and steel industry.
A-6
-------
From the Cost & Quality, or Electric Power Annual, obtain the total quantity of petroleum
coke consumed or received by power plants.
Add the values obtained in 1 and 2 above and petroleum coke receipts together to obtain the
total coke consumption.
Coke Oven Gas: Obtain the total coke-oven gas production, in cubic feet from Quarterly Coal
Report. Multiply this total by 0.188. It is assumed that 18.8 percent of total coke gas produced is
consumed outside of the iron and steel industry. If not published, call National Energy Information
Center (202) 586-8800. If not available, use previous year number.
Bagasse: Use the number from the previous year.
Kerosene: Obtain the "adjusted" quantity of kerosene sales in gallons, from Fuel Oil and Kerosene
Sales 19xx. Add the "adjusted" sales figures reported for industrial and !'all other."
LPG: Use LPG supplied to industrial use. American Petroleum Institute, Jim Tsiderdaos (202) 682-
8498, table entitled, "LPG Supply and Disposition." The objective is to project the 1982 consumption
figures, in gallons, to the update year based on the quantity of products supplied. The following
equations can be used:
Industrial = 5,397 * 106 gal.M, * LPG Supplied
1,499 * 103 bbl/day (eq. 48)
where,
i = year
5,397 x 106 gal = total industrial sales in 1982.
1,499 x 103 bbl/day = products supplied in 1982 obtained from Petroleum Supply Annual.
LPG Supplied = products supplied obtained from Petroleum Supply Annual
Wood: Obtain the consumption figures, in tons, from Estimates of U.S. Wood Energy Consumption,
1980-1983. This reference gives consumption in terms of oven-dried equivalent weight for the
previous year. For example, for the 1984 update, the reference was available for 1983. Assume that
15 percent of the heating value is lost to moisture on a typical basis. Therefore, multiply the
reported consumption figures in tons by 0.85. Do this for industrial and residential, separately. As
of 1990, wood consumption was published in therms of Btu's and an average Btu content per oven-
dried short ton was provided for both residential and industrial sectors. The ratio is:
77.2 million Btu
oven-dried short ton
No adjustment to the calculated tonnage is necessary.
A-7
-------
Next, project the converted consumption figure to the update year. Assume that 75 percent of the
industrial wood is consumed by the oulp and paper industry and 25 percent is used in lumber and
wood products. Refer to Section 3.15.3.7 [below] to obtain the production figures for the base and
update year. Then project as before (see LPG), but for pulp and paper and lumber and wood
products, separately. Add the projected consumption figures.
Pulp and Paper
Kraft: Use production found in Current Industrial Reports, Pulp, Paper and Board; use production
value reported for "sulfate."
Sulfite: Same reference as for Kraft; use production value reported for "sulfite."
Lumber.
Obtain the total lumber production expressed in million board feet from Current Industrial
Reports, Lumber Production and Mill Stocks. If not available, use Survey of Current Business.
Emission Factors
Coke:
Coke Type
Petroleum Coke
Coal Coke
LbsS/Ton
SO,
38.8
30.3
Calculate weighted average EF's based on the total coke produced from petroleum and the
total coke produced from coal (breeze production plus coke sales to boilers) as shown in Table 3.11-
1.
Use a sulfur content value of 3.25 percent for petroleum coke.
Table 3.11-1. Weighted Average Emission Factors for Coke
Coke Type
Petroleum Coke
Coal Coke"
Consumption (from
Part 3A)
554
1384
Weighted Average (metric Ibs/ton)
EF (metric Ibs/ton)
Part
1.4
4.2
SO,
114.3*
27.5
NOX
19
12.7
PM-10
1.2
9
* Assumes a constant sulfur content value of 3.25 percent for petroleum coke.
** Total of breeze production plus coke industrial boilers.
A-8
-------
Coke Oven Gas:
LbsS/106 Cubic Feet Burned
SCC SO/
1-02-007-07 680.0S
"Assume a sulfur content value of 1.605 percent.
Bagasse: Table 1.8-1, AP-42 Fourth Edition, Volume I
LbsS/Ton
SCC SO,
1-02-011-01 0
'Obtain percent control efficiency from AIRS AFP650, SCC 1-02-011-01. Currently this percent
control = 69 percent.
Kerosene:
LbsS/103 Gal.
SCC SO.
1-02-005-01 143.6S
'Assume a sulfur content value of 0.075 percent
LPG: Table 1.5-1, AP-42 Fourth Edition, Volume I
scc so.;
1-02-010-02 86.5S
'Assume a sulfur content value of 0.0013 percent.
Wood: Table 1.6-1, AP-42 Fourth Edition, Volume I
SCC SO,
1-02-009-01 .15
1-02-009-02 .15
1-02-009-03 .15
EF from print-out: Coke 47.8 MLbs/ton
Coke oven Gas 990.0 10*9 cu ft.
Kerosene 9.8 million gal.
LPG 0.1 million gal.
Wood 2.2 10*3 tons
A-9
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Primary Copper
Activity
Roasting- Obtain the primary copper smelter production from domestic and foreign ores from the
Minerals Yearbook, Copper. The Table is entitled, "Copper: World Smelter Production, by
country" This figure is expressed in units of blister copper produced. Convert to short tons and
multiply the reported number by 2. (This multiplier assumes that there are 4 tons of copper
concentrate/ton of blister, but only half is roasted.)
Smelting, Converting: Same as above but instead multiply the reported number by 4.
Fugitive: Use the total new copper smelter production figure obtained from Minerals Yearbook,
Copper. Total primary includes domestic and foreign ores. Convert to short tons.
Regional Fractions: Contact directly (i.e., telephone) the State or Regional Air Quality Bureaus for
copper smelter activity within their area.
Emission Factors
Roasting: Table 7.3-2, AP-42 Fourth Edition
SCC
3-03-005-02
3-03-005-09
Description
Multi-Hearth Roaster
Fluid-Bed Roaster
LbsS/Ton
SO,
280
360
Calculate a weighted average EF based on the data in Table 3.15-9. Multiply each EF by the
corresponding capacity. Add the products and divide by the total capacity. Then add 1 Ibs/ton to
the weighted average EF to account for fugitive emissions.
Table 3.15-9. Capacity Data
Type of Roaster
Multihearth
Fluid Bed
EF
280
360
1981 Capacity
430
230
A-10
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Smelting: Table 7.3-2, AP-42 Fourth Edition
SCC
Description
3-03-005-07 Reverb. Furnace + Convenors
3-03-005-03 Multi-Hearth + Reverb. Furnace + Convenors
Fluid Bed Roaster + Reverb. Fum. + Convenors
3-03-005-10 Electric Furnace + Convenors
Fluid Bed + Electric Arc + Convenors
3-03-005-26 Flash Furnace + Cleaning Furnace + Convenor
90
LbsS^Ton
SO.
320
180
160
240
820
Calculate a weighted average EF based on the data in Table 3.15-10. Multiply each EF by
the corresponding capacity. Add the products and divide by the total capacity. Then add 4 Ibs/ton
to the weighted average EF to account for fugitive emissions.
Table 3.15-10. Smelting Emission Factor Data
Type of Process
Reverb. Furnace + Convenors
Multihearth + Reverb. Furnace + Convenors
Fluidized Bed Roasters + Reverb. Furnace +
Convenors
Electric Furnace + Convenors
Fluidized Bed Roaster + Electric Arc + Convenors
Flash Furnace, Cleaning Furnace, Convenor
EF (Ibs/ton)
320
180
160
240
90
820
1981
Capacity
405
430
212
124
18
115
Converting: Table 7.3-2, AP-42 Fourth Edition
SCC Description
3-03-005-23 Reverberatory Furnace + Convenor 740
3-03-005-24 Multi-Hearth + Reverb. + Converter
3-03-005-25 Fluid Bed Roaster + Reverb. + Converter 540
3-03-005-26 Electric Arc + Converter
3-03-005-27 Flash Furn. + Cleaning Furn. + Converter 240
3-03-005-28 'Noranda Reactor + Converter 600
LbsS/Ton
SO.
600
820
'Assumed value used for Noranda Reactor emission factor.
Same procedure as for Roasting and Smelting except use the data in Table 3.15-11. Add 130
Ibs/ton to the weighted average EF to account for fugitive emissions.
A-ll
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NOTE: For copper smelting, calculation of new weighted average emission factors is needed only if
an existing smelter ceases operation or if a new smelter begins operation or if an existing smelter is
modified. See Minerals Yearbook, Copper for information on such changes in capacity.
Table 3.15-11. Converting Emission Factor Data
Type of Process
Reverb. Furnace + Convenors
Multihearth + Reverb. Furnace + Convenors
Fluidized Bed Roasters + Reverb. Furnace +
Convenors
Electric Arc Furnace + Convenors
Flash Furnace, Cleaning Furnace, + Convenors
Noranda Reactor + Convenors
EF (Ibs/ton)
740
600
540
820
240
600
1981
Capacity
405
448
212
124
115
231
Primary Zinc
Activity
Roasting: Obtain the total slab zinc production from the Minerals Yearbook. Zinc. Convert the
units to short tons and multiply by 2 to account for the fact that there are 2 units of concentrate/ton
slab zinc.
Emission Factor
Zinc Roasting: Table 7.7-1, AP-42 Fourth Edition
LbsSAbn
1,100
SCC
3-03-030-02
EF from print out: 998.0 MT Lbs/ton
Control
Control efficiency is derived from AIRS/FS (eq. 1) for all subcategories except Zinc-Fucitive The
control efficiency for this subcategory is obtained by best guess.
A-12
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Primary Lead
Activity
For all subcategories, obtain the primary refined lead production from domestic and foreign
ores from the Minerals Yearbook, Lead. Convert the units to short tons.
Lead Processing.
In order to calculate a production value for lead processing the following procedure should be
used:
1. The total copper and zinc SO2 emissions must be calculated first.
2. Then calculate SO2 Removal in H2SO4 as follows:
Byproduct Sulfuric Acid - Copper: Obtain the quantity of byproduct sulfuric acid produced from
Copper plants in the United States (Minerals Yearbook. Copper). Multiply this total by 0.6531. This
is the ratio of the molecular weight of SO2 (64) to the molecular weight of H2SO4 (98). Enter the
result in the TRENDSXX.xls file "Sulfur Oxide Emissions from Non-Ferrous Smelters, SO2 Removal
in H2SO4," for Copper.
Byproduct Sulfuric Acid - Lead + Zinc (SO2 lead+zinc): Add the quantity of byproduct sulfuric
acid produced from Lead plants from Minerals Yearbook, Lead, to the quantity of byproduct sulfuric
acid produced from Zinc plants. Again multiply this total by 0.6531. Enter the result in the
TRENDSXX.xls file "Sulfur Oxide Emissions from Non-Ferrous Smelters, SO2 Removal in H2SO4,"
for a total of Lead+Zinc byproduct sulfuric acid produced.
In the event the Minerals Yearbook, Copper is unavailable, one must estimate the byproduct
sulfuric acid production from copper, lead, and zinc processing. The Bureau of Mines may also be
able to supply preliminary numbers for these calculations.
3. Then calculate total lead SO2 emission as follows:
In order to calculate Total S0; Lead Emissions' the following procedure should be used:
AFS
Total SO2 = SO2 (lead+zinc) - SO2(zinc) + [ Lead * .9072] (eq. 68)
Lead Emissions Emissions
where:
SO2(lead+zinc) is the total SO2 removed in byproduct sulfuric acid production from lead +
zinc processing, calculated above.
SO2(zinc) = Total SO2 removed in byproduct sulfuric acid production from zinc processing.
Calculated as follows:
A-13
-------
Byproduct sulfuric acid prod, from zinc plants * 0.6351 (eQ- 69)
AIRS/FS Lead Emissions = the total S02 emissions from lead production, SCC 303 010 **.
This is obtained from a AIRS/FS AFP650 report for the latest year available.
4. Once this is done, it is easy to back calculate a lead processing value.
Calculation is as follows:
Lead Processinc = Total SO. Lead Emission * 2000 (eq. 70)
540
The value for 'Lead Processing' may now be entered into TRENDSXX.xls.
Emission Factors
Lead Roasting: Table 7.6-1, AP-42 Fourth Edition
"LbsS/Ton Lead Produced
SCC Description SO,
3-03-010-01 Sintering 550
3-03-010-02 Blast Furnace 45
'AP-42 units are based on quantity of lead produced.
'NEDS SCC file units are based on tons of concentrated ore produced.
EF Lead Processing from print-out: 540.0 MT Ibs/ton
Control
Control efficiency is derived from AIRS/FS (eq. 1) for all subcategories except Lead-
Fugitive. The control efficiency for this subcategory is obtained by best guess.
Primary Aluminum
Activity
Material Handling: Use the total primary production figure obtained from the Minerals
Yearbook, Aluminum.
Emissions Factors
Obtain an average EF based on NEDS, February 1980, for Washington State only.
EF from print-out: 33.5 MT Ibs/ton
A-14
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Control
Control efficiency is derived from AIRS/FS (eq. 1) for all subcategories except
Aluminum-Fugitive. The control efficiencies for this subcategory is obtained by best guess.
Secondary Lead
Activity
Reverberatory Furnaces: Obtain the total consumption of lead scrap and multiply by the
following fraction:
Lead recovered as soft lead/Total lead recovered from scrap
Convert to short tons.
Blast Furnaces: Same as for Reverberatory Furnaces except that the fraction is calculated as
follows:
Lead recovered as antimonial lead/Total lead recovered from scrap
Convert to short tons.
Emission Factors
Table 7.11-1, AP-42 Fourth Edition
LbsS/Ton
SCC Description SO.
3-04-004-02 Reverberatory Furnace 80
3-04-004-03 Blast Furnace 53
EF from print-out: Reverberatory Furnace 72.6 MT Ibs/ton
Blast Furnace 48.0 MT Ibs/ton
Control
Control efficiency is derived from AIRS/FS (eq. 1) for all subcategories except Lead-
Fugitive. The control efficiency for this subcategory is obtained by best guess.
Pulp and Paper
Activity
Kraft Pulp Production.
Obtain the production of sulfate and sulfite combined from Current Industrial Reports.
& Board. Kraft process and Sulfite process are reported individually in this
A-15
report.
-------
Kraft: Use production found in Current Industrial Reports. Pulp. Paper and Board; use
production value reported for "sulfate."
Sulfite: Same reference as for Kraft; use production value reported for "sulfite."
Emission Factors
Kraft Pulp Production: Table 10.1-1, AP-42 Fourth Edition
LbsS/Ton
sec sex
3-07-001-04 7
The EF is obtained by adding the EF's for Kraft and Sulfite Mills. In the case of
Kraft use the AP-42 EF of 7 Ibs/ton (see above). In the case of Sulfite, the EF must be
calculated as described below.
Sulfite Uncontrolled EF = 52 Ibs/ton*
Sulfite Controlled EF = 20 Ibs/ton"
If the sulfite paniculate control efficiency is 90 percent (taken from Table 2.25), then
assume 90 percent of production is at the controlled emission rate and 10 percent at the
uncontrolled rate. Calculate SO2 emissions from sulfite mills and add to the emissions for
Kraft Mills (5 Ibs/ton). Calculate the EF as follows:
EF = (Total Emissions, Kraft + Sulfite)/Production (eq. 63)
'Obsolete version of AP-42.
EF from print-out Kraft Pulp Prod. & Sulfite: 10.3 MT Ibs/ton
Sulfuric Acid
Activity
Obtain the total production from Current Industrial Reports. Inorganic Chemicals.
Emission Factor
Calculate the EF as follows:
EF,=
(0.95 * EF. , Jl_P,.,) + (0.05 * EFvCPc *_P. .) + (fP. - P.,) * EFVW)
P' (eq. 64
A-16
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where,
i = Year
EFNSPS = NSPS EF (4 Ibs/ton)
p = Total Production
If the current year production is less than the previous year production, the last term
(Pj - P,.,) is zero. Only assume new capacity for production above the previous record high
production level.
EF from print-out: 7.8 MT Ibs/ton
Carbon Black Production
Activity
Obtain the total quantity of carbon black produced from C&E News.
Oil Process: Assume that 90 percent of total production is by oil process.
Gas Process: Assume that 10 percent of total production is by gas process.
Emission Factors
Table 5.3-3, AP-42 Fourth Edition
LbsS/Ton
Description SO.
Flared Furnace Exhaust (Oil Process) 50
Calculate the EF as follows:
EF = (CO Control Efficiency / 0.913) * 50 Ibs/ton (eq. 73)
where,
CO Control Efficiency = fraction.
EF from print-out: 20.6 MT Ibs/ton
Sulfur Recovery Plants
Activity
Obtain the quantity of sulfur recovered by petroleum refineries and by natural gas
plants, respectively, from the Minerals Industry Survey, Sulfur. Convert to short tons.
A-17
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Emission Factors
Add the actual emissions reported in AIRS/FS for SCC 301-032-01 through
301-032-04. Divide the total by the sum of the operating rates.
Petroleum Refining
Activity
From the Oil and Gas Journal, obtain the total capacity of catalytic cracking fresh feed
in bbl/stream day. Convert this number to bbl/calendar year by multiplying by 328.5 (365
days/year * 0.9 calendar day/stream day).
Prior to 1989, it was possible to obtain from Oil and Gas Journal, the sum of the
catalytic cracking fresh feed capacity per plant for Thermofor and Houdriflow combined with
the "other" category, as opposed to the "fluid" category, as designated by footnotes. This
"other" category represented TCC. The total capacity was converted to bbl/calendar year by
multiplying by 328.5. Then subtract this number from the total capacity above as follows:
Total Catalytic
FCC Capacity = Cracking Capacity - TCC Capacity (eq. 64)
Then it was necessary to convert capacity to throughput. From the Survey of Current
Business, in table containing information on Petroleum, Coal, and Products, obtain the
refinery operating ratio. Divide the ratio by 100 to convert it to percent, and multiply the
estimated capacities for FCC and TCC by the relevant number to get an estimate of
throughput
Since 1989, the Oil and Gas Journal no longer gives catalytic cracking fresh feed for
Thermofor and Houdriflow. Therefore, multiply the total capacity of catalytic cracking fresh
feed in bbl/stream day by 328.5 and by the refinery operating ration. Also, add the total FCC
and TCC reported in TRENDSXX.xls for the previous year. Then calculate FCC and TCC
for the update year as follows:
FCC, = FCC,, * cc^m (eq. 65)
cc(FF),.,
TCC, = TCC,, * ccim (eq. 66)
cc(FF),.,
Process Heaters.
Oil: Obtain the quantity of oil consumed at petroleum refineries by PAD District from
Petroleum Supply Annual. Obtain the total of distillate, residual and crude oil Divide hv
1,000. ' y
A-IX
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: Obtain the total of natural gas and still (process) gas consumed at petroleum refineries
Petroleum Supply Annual. The quantity reported for still gas is expressed as thousand
bbl equivalents. Multiply the reported number by 6.3 to get 106 cu. ft.
Emission Factors
LbsS/103 BBL Fresh Feed
___SCC__ Description SO,
3-06-002-01 Fluid Catalytic Cracking 493
3-06-002-02 Thermal Catalytic Cracking 60
3-06-004-01 Flares (Blowdown System) 26.9
1-02-004-01 Process Heaters: Oil 158.6S
3-06-001-05 Process Heaters: Natural Gas .6
3-06-001-06 Process Heaters: Process Gas 950.0S
The EF's for FCC, TCC, and Flares may be entered directly into the spreadsheet.
Process Heaters:
Oil: Obtain the EF from AP-42 for industrial- residual oil boilers. Estimate sulfur content
from AIRS/FS AFP650 report for SCC 30600103.
Gas: Weight the EF's for Natural Gas (0.6 lbs/106 cu.ft.) and Refinery Gas (356.25 lbs/106
cu.ft) by the natural gas and refinery gas consumption obtained from Petroleum Supply
Annual. Convert bbl's of Refinery (Still) Gas to 106 cu. ft. by multiplying by 6.3.
EF from print-out: MT Ibs/ton
FCC 447.2
TCC 54.4
Flares 24.4
Process Heaters:
Oil 5680.0
Gas 230.1
Iron and Steel
Activity
Use the same numbers as in the Megacalc Table 3.15.3.3, "Paniculate Emissions from
the Iron and Steel Industry", on coke, sintering, and open hearth, convert to thousand short
tons from million short tons. For roll and finish, obtain the total raw steel production from
the Survey of Current Business, in the table containing information on "metals and
manufactures".
A-19
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Coke.
Byproduct: Obtain the beehive and oven (byproduct) production figure, expressed in
thousand short tons, from Survey of Current Business, in the table showing information on
"Petroleum, Coal, and Products." SCC=3-03-003
Sintering.
Obtain the total production of pig iron from Mineral Industry Survey. Iron Ore, ref. 25
or use the total reported in the Survey of Current Business. Convert long tons to short tons:
divide result by 3 and enter as 3 components of sintering (windbox, discharge, and sinter-
fugitive).
Open Hearth.
From Mineral Industry Surveys. Iron and Steel Scrap, obtain the total scrap and pig
iron consumed by open hearth, furnaces by manufacturers of pig iron and raw steel and
castings. Calculate the fraction of scrap and pig iron (combined) that is consumed by the
furnace types. Multiply the fraction by the total raw steel production, expressed in thousand
short tons, obtained from the Survey of Current Business, in the table showing information on
"Metals and Manufactures." Enter the calculated values both the "stack" and "fugitive"
components of each furnace type. (Note: The fraction for open hearth furnace will be used
in several tables of the OAQPS Data File. Once the Minerals Yearbook. Iron and Steel
chapter, is available, values calculated above should be revised to agree with Minerals
Yearbook final data.)
Emission Factors
Coking: "Table 7.2-1, AP-42 Fourth Edition
NED SCC and Emission Factor File
SCC Description
3-03-003-02 Charging
3-03-003-03 Pushing^
3-03-003-04 Quenching
3-03-003-06 Underfiring
3-03-003-08 Oven/Door Leaks
3-03-003-14 Topside Leaks
Add the factors and divide by 0.7 to convert units. This is based on 0.7 tons coke
produced/ton coal consumed.
Sintering: Divide the actual emissions reported in NEDS, February 1980, by the production
TcltC.
A-20
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Pfin Hearth: Same procedure as for Sintering.
**°" and Finish: The objective is to compute fuel use by process equipment For SO2, the
fuels are coke oven gas and residual oil. Multiply the quantity of fuel use by the
corresponding AP-42 EF. For example:
Quantity of Coke Oven Gas * 1,091 lbs/106 cu.ft.
Quantity of Residual Oil * 1,595 lbs/1,000 gal.
Coke oven gas used in iron and steel manufacturing is calculated as follows: (1)
Obtain total annual coke oven gas production from Quarterly Coal Report, (2) Assume 40
percent of production is used in iron and steel process equipment. (3) The EF for coke oven
gas (1,091 lbs/106 cu.ft.) is obtained from AP-42. (4) Multiply fuel quantity by the EF
Residual Oil used in iron and steel manufacturing is calculated as follows: (1) From
the survey of Current Business, containing information on Metals and Manufactures, obtain
the quantity of raw steel production in short tons and multiply by 0.00738 * 106 gal/10J ton
steel. (This value should be updated for 1982 and later years based on the 1982 Census of
Manufacturers, Fuels and Electric Energy Consumed). (2) The EF for industrial boilers
(1,595 lbs/1,000 gal) is used as calculated for the TRENDSXX.XLS file "SO^Fmissions
from Residual Oil Combustion." (3) Multiply fuel quantity by the EF. (4) Assume percent
Sulfur for industrial-residential oil boilers calculated for the table on SO2 emissions applies.
Add emissions together to obtain total SO2 emissions. Then subtract the quantity of
emissions from Open Hearth Furnaces shown in the TRENDSXX.xls file "SO2 Emissions
from Other Industrial Processes." Calculate the EF as follows:
EF = Emissions left over / Roll and Finish Operating Rate (eq. 74)
EF from print-out: MT Ibs/ton
Coking 10.3
Sintering 2.3
Open Hearth 1 .4
Roll & Finish 3.5
Cement Manufacturing
Activity
Obtain the total quantity of cement production from Mineral Industry Survey. Cement.
Use the same figure for all subcategories.
A-21
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Emission Factors
The first objective is to calculate total uncontrolled SO2 emissions. These emissions
are a function of mineral sources of SO2 and sulfur in fuel used to fire kilns. Obtain total
cement production from Minerals Industry Survey. Cement. The EF's shown in Table 3.15-
12 are used to calculate uncontrolled emissions. Add these emissions and divide by the total
cement production rate to get the uncontrolled EF.
At this point, it is convenient to estimate control efficiency. The baseline value of
13.75 percent S0: control corresponds to a cement kiln paniculate control efficiency of 99
percent. The value of 12 percent SO: control corresponds to a cement kiln control efficiency
of 92 percent. For other percent SO: control values, estimate the corresponding cement kiln
SO: control efficiency value by linear interpolation/extrapolation from the paniculate control
efficiency.
Table 3.15-12. Emission Factors for Uncontrolled Emissions
Fuel
Mineral Source
Coal
Residual Oil
Distillate Oil
Emission Factor
10.2 Ibs/ton cement produced
30.45 Ibs/ton coal consumed1
124.5 lbs/1,000 gal residual oil consumed2
112.35 lbs/1,000 gal distillate oil consumed3
1 S = value derived for industrial boilers, Section 3.7.
2 S = value derived for industrial boilers, Section 3.8.
3 S = 0.3
EF from print-out: 14.5 MT Ibs/ton
Glass
Activity
Refer to Current Industrial Reports, Glass Containers and Current Industrial Reports
Rat Glass. Add the following quantities, after converting to thousands of short tons, as
necessary:
A-22
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1. Total production of flat glass (in short tons)
2. Net packed weight of glass containers (in thousands of pounds)
Multiply the total by 1.10 to account for miscellaneous glass products.
Emission Factors
Table 8.13-1, AP-42 Fourth Edition
sec
3-05-014-02
3-05-014-03
3-05-014-04
Description
Container Glass: Furnace
Flat Glass: Furnace
Blown Glass: Furnace
LbsS/Ton
SO.
3.4
3.0
5.6
Weighting
Factor
.75
.15
.1
Calculate a weighted average EF based on the weighting factors in the above table.
Table 3.15-13. Weighting Factors
Type of Glass
Container Glass
Flat Glass
Blown Glass
Weighting Factor
0.75
0.15
0.1
EF from print-out: 3.2 MT Ibs/ton
Lime Manufacturing
Activity
Obtain the production figure from C & E News, for lime. Enter the obtained value for
both kilns and fugitive.
Emission Factors
Divide the total actual SO2 emissions reported in NEDS, February 1980, by the NEDS
lime production rate.
EF from print-out: 3.1 MT Ibs/ton
Control
vve- Obtain a value for control efficiency by best guess.
A-23
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/R-94-012
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Comparison of the 1985 NAPAP Emissions Inventory
with the 1985 EPA TRENDS Estimate for Industrial
SO2 Sources
5. REPORT DATE
January 1994
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
David Zimmerman and Rebecca Battye
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
EC/R Incorporated
University Tower, Suite 404
3101 Petty Road
Durham, North Carolina 27707
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D2-0181,
(TRC)
Tasks 2 and 8
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 3-10/93
14. SPONSORING AGENCY CODE
EPA/600/13
15.SUPPLEMENTARY NOTES AEERL -ectofficer ig Charles c> Masser, Mail Drop 62, 9197
541-7586.
IB. ABSTRACT The report'g^gg results Qf analyses of 1985 industrial sulfur dioxide (SO2)
emissions from two data sources: the National Acid Precipitation Assessment Pro-
gram (NAPAP) inventory and the EPA TRENDS report. These analyses conclude that
the two data sources estimate comparable emissions in the aggregate, but that esti-
mates for specific categories and for processes within those categories vary widely.
The TRENDS method, limited to source categories that emit 10,000 tonnes of SO2 per
year, generally overestimates emissions from these source categories, due prima-
rily to the absence of SO2 control efficiency assumptions. Overestimating emissions
in the TRENDS data set is offset by including additional source categories in the NA-
PAP inventory, with the final aggregate estimates within <10% of each other. Due to
these findings, the TRENDS methodologies are being revised for 1993 and thereafter,
using the 1985 NAPAP inventory as a base. (NOTE: The 1990 Clean Air Act Amend-
ments (CAAA) require that EPA report to Congress by 1995 a national inventory of
annual SO2 emissions from industrial sources, and emission projections for the next
20 years. This stems from the 5.6 million tons of industrial SO2 emissions cited in
CAAA Title IV, and based on the estimated 1985 NAPAP emissions.)
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Sulfur Dioxide
Emission
Inventories
Pollution Control
Stationary Sources
NAPAP
TRENDS
13 B
07B
14G
15E
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
202
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
A-24
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