United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 277\ \
Research and Development
EPA/600/S7-90/010 Aug. 1990
SEPA Project Summary
Emissions and Cost
Estimates for Globally
Significant Anthropogenic
Combustion Sources of NO
2O,CH4, CO, andCO2
x/
Stephen D. Piccot, Jennifer A. Buzun and H. Christopher Frey
Emission factors for carbon dioxide
(CO2), carbon monoxide (CO), methane
(CH4>, nitrogen oxides (NOX), and nitrous
oxide (NaO) were developed for about 80
globally significant combustion sources
in 7 source categories - utility, industrial,
fuel production, transportation, residen-
tial, commercial, and kilns/ovens/dryers.
Because of the lack of adequate interna-
tional data, the emission factors for most
sources are based on U.S. performance
cost, and emissions data. Data on COa,
CO, and NOX were available for over 90%
of the sources studied; on ChU, for about
80%; on NaG, for only about 10%. Emis-
sion factor quality ratings were
developed to indicate the overall ade-
quacy of the supporting data. Quality
ratings ranged from A to E, A the best.
Except for NaO, the emission factors for
the gases covered the quality spectrum
from A to E; all of the emission factors for
NaO were rated E. Evaluation of the emis-
sion factors for the seven source
categories (taking the five gases as an
aggregate for each category) showed
that the kilns/ovens/dryers category had
the lowest overall quality rating; no fac-
tors rated better than B. Emission factors
for fuel production were somewhat bet-
ter, but generally of lower quality than
those for the remaining five source
categories.
This Project Summary was developed
by EPA's Air and Energy Engineering Re-
search Laboratory, Research Triangle
Park, NC, to announce key findings of the
research project that Is fully documented
in a separate report of the same title (see
Project Report ordering information at
back).
Introduction
The U.S. EPA was asked by Congress
under the National Climate Program Act to
report on the environmental effects of global
climate change and the options available to
the global community to mitigate and adapt
to potential global warming. The U.S. Na-
tional Climate Program established by the
National Climate Program Act involves
several agencies and organizations
engaged in interdisciplinary analysis of
global climate and related issues. Within
EPA, several programs have been estab-
lished to perform the work necessary for
supporting the National Climate Program
and to provide the analysis and assess-
ments necessary for the reports to Con-
gress. EPA's Air and Energy Engineering
Research Laboratory (AEERL) is supporting
the technical effort required to estimate a
global greenhouse gas emission inventory
and to identify options to reduce these emis-
sions. The technical effort includes
development of emission, efficiency, and
cost estimates for globally significant green-
house gas emission sources and develop-
ment of performance and cost estimates for
emission control technologies.
Rapid expansion of global population and
industrial activity has dramatically increased
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creased the emissions of gases and pol-
lutants that are referred to as greenhouse
gases. Greenhouse gases transmit solar
radiation and absorb infrared radiation, as
does the glass in a greenhouse, and could
result In significant increases in the global
average surface temperature. In the report
to Congress, several atmospheric trace
gases are to be evaluated. The gases con-
sidered are COa, CO, CHU, NOX, and NaO,
which are considered greenhouse gases or
are precursors of atmospheric chemical
reactions that produce greenhouse gases.
The concentrations of these five gases are
currently increasing due to both
anthropogenic and biogenic emission sour-
ces.
Anthropogenic emission sources include
combustion and noncombustlon sources.
The combustion of fossil fuels is generally
considered the major cause of increasing
atmospheric COa and CO concentrations.
Fuel combustion is also responsible for sig-
nificant emissions of NOX, including both NO
and NOa. NOa and NO are not greenhouse
gases, but they are precursors of the forma-
tion of ozone, an active greenhouse gas in
the troposphere. Although the emissions of
NaO from combustion are small on a mass
basis when compared to the emissions of
COa, NaO is over 250 times more effective
than COa in absorbing infrared radiation.
The purpose of this effort is to develop
emission factor estimates and other data for
combustion sources of greenhouse gases.
The emission factors developed for this
report are intended for use in estimating a
global emission inventory of COa, CO, cm,
NOX, and NaO. To provide options for
stabilization and reduction of emissions of
these gases, emission control technologies
are identified for the combustion sources.
The emission reduction capabilities of emis-
sion control technologies can be incor-
porated into developing a global emission
inventory and into forecasting global emis-
sions under various scenarios.
Scope
This project is limited to the evaluation of
significant combustion sources of green-
house gases. Only sources and controls for
which data are readily available are included
in this report. Performance and cost es-
timates for advanced combustion tech-
nologies and controls and for
noncombustion sources and controls were
not included in this study.
Anthropogenic Sources
Included in the Study
An initial list (Table 1)of about 90 combus-
tion sources was developed as a starting
Table 1. Initial List of Combustion Sources of Greenhouse Gases
Major Categories
Subcategories
Utilities
Industrial Boilers
Fuel Production
Gas - boiler
Gas - combined cycle
Gas turbines
Residual oil
Distillate oil
Shale oil
Municipal waste - mass feed
Municipal waste - refuse-derived fuel
Coal - spreader stoker
Coal - fluid bed - combined cycle
Coal - fluid bed - boiler
Coal - pulverized coal - cyclone
Coal - pulverized coal - tangential
Coal - wall fired
Wood
Wood
Gas - low thermal efficiency
Gas - high thermal efficiency
Residual - low thermal efficiency
Residual - high thermal efficiency
Distillate - low thermal efficiency
Distillate - high thermal efficiency
Municipal waste
Refuse-derived fuel
Coal - fluid bed
Coal - spreader stoker - low thermal efficiency
Coal - spreader stoker - high thermal efficiency
Coal - pulverized coal
Coal - mass stoker
Bagasse/agricultural waste
Gas production & refining
Oil production & refining - W/CH4 wastage
Oil production & refining - w/o CH4 wastage
Coal production & cleaning
Oil shale production & refining
Coal gasification - current technology
Coal gasification - advanced technology
Coal liquefaction
Charcoal production
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Table 1. (Continued)
Major Categories
Subcategories
Transportation
Residential/Commercial
Heaters/Furnaces/Kilns/ Ovens/Dryers
Rail
Jet aircraft
Ships
Aviation gasoline
Gasoline - light duty - pre-control
Gasoline - light duty - post-control
Gasoline - heavy duty
Gasoline - light duty
Diesel-light duty
Diesel - heavy duty
Methanol - light duty
Methane - light duty
Internal combustion engines - diesel pipeline transportation
Internal combustion engines - gas pipeline transportation
Gas turbines
Direct fired - wood pits
Direct fired - wood fireplace
Direct fired - wood stove - old/modern
Direct fired - gas heater - old
Direct fired - gas heater- modern (pulse)
Direct fired - oil - old
Direct fired - oil - modem
Direct fired - coal fireplace
Direct fired - coal stove
Direct fired - coal central heat
Direct fired - propane/butane
Boilers - wood
Boilers - gas
Boilers - residual oil
Boilers - distillate oil
Boilers - municipal waste
Boilers - coal
Boilers - shale
Waste reduction - open burning - municipal waste
Waste reduction - open burning - agricultural
Waste reduction - incineration - low efficiency
Waste reduction - incineration - high efficiency
High temperature - distillate oil
High temperature - gas
High temperature - residual oil
High temperature - coal
High temperature - shale oil
Intermediate temperature - distillate oil
Intermediate temperature - gas
Intermediate temperature - residual oil
Intermediate temperature - coal
Intermediate temperature - shale oil
Low temperature - distillate oil
Low temperature - gas
Low temperature - residual oil
Low temperature - coal
Low temperature - shale oil
point for the collection of emission and con-
trol technology data. After a review of the
available literature and discussions with
various experts, the list was revised to
roughly 80 sources (Table 2).
The utility sources in Table 2 are the same
as those in Table 1. The industrial boiler
category was modified because data were
not readily available for the population of
high versus low efficiency boilers, nor were
emission factors readily available for in-
dustrial boilers categorized based on ef-
ficiency. The different coal-fired industrial
boiler technologies in Table 1 are repre-
sented by a single coal-fired industrial boiler
category in Table 2. Distillate oil-fired boilers
were not included in Table 2. Fired heaters
were added as part of the fuel production
category because they are an integral part of
the petroleum refining process, the initial
list of transportation sources is unchanged
in the revised list except for deletion of post-
control light duty vehicles; the effect of con-
trol technologies for light duty vehicles is
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Tab/e 2. Revised JL/sf of Combustion Related Emission Sources
UTILITY
Natural Gas Boilers
Gas Turbine Combined Cycle - Natural Gas
Gas Turbine Simple Cycle - Natural Gas
Residual OH Boilers
Distillate OH Boilers
Shale Oil Boilers
Municipal Solid Waste - Mass Feed
Municipal Solid Waste - Refuse Derived Fuel
Coal - Spreader Stoker
Coal - Fluldlzed Bed Combined Cycle
Coal - Fluldized Bed
Coal - Pulverized Coal Cyclone Furnace
Coal - Pulverized Coal Tangential Fired
Coal - Pulverized Coal Wall Fired
Wood-Fired-Boilers
INDUSTRIAL
TRANSPORTATION
Rail
Jet Aircraft
Aviation- Gasoline
Ships
Light Duty Gasoline Vehicle
Heavy Duty Gasoline Vehicle
Light Duty Diesel Vehicle
Heavy Duty Diesel Vehicle
Light Duty Methanol Vehicle
Light Duty Compressed Natural Gas Vehicle
Internal Combustion Engine-Diesel (Pipeline)
Internal Combustion Engine- Natural Gas (Pipeline)
Gas Turbine - Natural Gas (Pipeline)
RESIDENTIAL
Coal-Fired Boilers
Residual Oil-Fired Boilers
Natural Gas-Fired Boilers
Wood-Fired Boilers
Bagasse/Agricultural Waste-Fired Boilers
Municipal Solid Waste - Mass burn
Municipal Solid Waste - Small modular
FUEL PRODUCTION
Wood Pits
Wood Fireplaces
Wood Stoves
Propane/Butane Furnace
Coal Hot Water Heater
Coal Furnaces
Coal Stoves
Distillate Oil Furnaces
Natural Gas Heaters
COMMERCIAL
Natural Gas Refining
Catalyst Regeneration
Refinery- Natural Gas Waste Flared
Refinery- Natural Gas Waste Used
Coal Dryer
OH Shale - Surface Retorting
Oil Shale - In-S!tu Retorting
Lurgl Coal Gasification
Coal Liquefaction - Acid Gas
Charcoal Production
Waste Flare - Pure Methane
Waste Flare - Natural Gas
Fired Heater - Natural Gas
Fired Heater-Process Gas
Fired Heater- Distillate Oil
Fired Heater- Residual Oil
Wood Boilers
Natural Gas Boilers
Residual Oil Boilers
Distillate Oil Boilers
Municipal Solid Waste Boilers
Coal Boilers
Shale Oil Boilers
Open Burning - Municipal Solid Waste
Open Burning - Agricultural
Incinerator - Multistage
Incinerator - Single Chamber
KILNS/OVENS/DRYERS
Kilns - Natural Gas (Cement or Lime Kiln)
Kilns - Oil (Cement or Lime Kiln)
Kilns - Coal (Cement or Lime Kiln)
Coke Oven - Coke Oven Gas
Dryer - Natural Gas
Dryer-Oil
Dryer-Coal
estimated as part of the control technology
performance estimates. The original
residential and commercial category was
divided. Sources within these categories for
the original list are included in the revised list;
however, no data were readily available to
distinguish the performance of old from
modem residential sources, so this distinc-
tion Is not made in the revised table. Insuffi-
cient data were readily available to justify the
subdivision of kilns, ovens, and dryers
based on operating temperature, and no
data were readily available from which to
estimate emissions of these sources from
the combustion of shale oil.
Type of Data Collected
Table 3 shows the format of the source
performance and cost data presented in the
report. The data for each of the emission
sources includes the energy conversion ef-
ficiency for utility, industrial boiler, residen-
tial, commercial, fuel production, and kilns/
ovens/dryers. Plant costs were developed
for utility and industrial boiler sources, and
were levelized on an energy input or energy
output basis depending on the availability of
an efficiency estimate. Emission factors
were developed on an energy output basis
for utility, industrial boiler, and commercial
sources, and for some other sources where
applicable efficiency data were available.
Emission factors for the remaining sources
were developed on an energy input basis,
except for some fuel production sources, for
which emission factors were developed
based on crude oil production. All of the
combustion technologies considered in this
project are currently available.
For each emission source in Table 2, an
effort was made to identify applicable emis-
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sion control technologies. Most of the con-
trol technologies included in the report are
currently available. However, some ad-
vanced control technologies were included
in this study to provide an option for more
stringent control of a specific greenhouse
gas or, as for advanced utility controls for
COa, to provide an option for controlling a
gas that cannot be reduced by current
methods.
The general format of the control technol-
ogy performance and cost data is shown in
Table 4. For control technologies, an ef-
ficiency penalty on the combustion technol-
ogy was estimated, as was the removal
efficiency for the five greenhouse gases
considered in this study. Emission control
costs were developed on an energy input or
energy output basis, depending on the basis
for the combustion technology cost. For
each control technology, an availability date
was estimated.
The emission factors developed in the
report represent sources without control
technologies. To calculate the baseline
global emission inventory for the regions of
the world, appropriate controls can be ap-
plied to specific source categories to repre-
sent the current application of control
technologies in some countries. The report
does not identify controls to be applied to
represent current control levels in different
parts of the world.
Data Quality
For each emission factor, a data quality
rating was assigned to indicate the relative
quality of the emission factors within the
database. The data quality ratings can also
be used to identify areas that could benefit
from additional research. A few of the fac-
tors that affect the quality of an emission
factor are the quality of the emission data,
(typically available on the basis of mass of
pollutant emitted per mass of fuel burned),
the quality of the fuel properties used to
convert the emission factor to an energy
basis, and the quality of efficiency estimates
used to convert the emission factor to an
end-use energy basis. The emission data
may be subject to variability due to variations
in the design, operation, and maintenance at
specific sources. These factors were taken
into consideration when assigning emission
factor ratings.
Summary of Results
For this study, performance and cost es-
timates were developed for globally sig-
nificant combustion sources of CO2, CO,
CH4, NOX, and NaO and for applicable emis-
sion control technologies. Although the in-
tent of this work was to develop globally
representative estimates, international per-
formance and cost data were not readily
available for most of the sources and con-
trols. In many cases, data were not available
from which to estimate the emission factors
of all five of the gases for a given source; in
particular, few data are available from which
to estimate emission factors for NaO. The
emission factors for COa were generally cal-
culated from a carbon balance.
For most sources and control tech-
nologies, the performance and costs are
based on U.S. data. The emission data
developed under various EPA projects rep-
resent the most extensive, highest quality,
and most accessible information available
from which to calculate emission factors,
efficiency, cost, and emission control
removal efficiency, efficiency penalty, and
cost. Although data are available from the
United Nations to estimate global fuel con-
sumption and in some cases energy conver-
sion efficiency, the data readily available
from the United Nations Statistical Office and
Environment Programme are not suitable for
a disaggregated analysis (i.e., few data are
available for specific combustion tech-
nologies). However, the United Nations
data can be used to estimate, for example,
the overall energy conversion efficiency of
Table 3. Combustion Emission Source Data Format
Emission Source
Technology
Efficiency
(%)
Cost
($/]oule)
Emissions (kg/joule)
Applicable Control
COz CO CH4 AfcO A/Ox Technology Codes
Utility eff. = fuel heat Joule = energy
value/electricity delivered to user.
delivered to user.
Joule = energy delivered to user
except transportation and
kiln/oven/dryer where joule is
fuel heating value. Emissions =
uncontrolled emissions.
Industrial and
residential eff. = fuel
energy in/energy
delivered to user.
$ = cost in 1985
excluding fuel costs.
Table 4. Emission Control Technology Data Format
Control
Technology
Device
Code
Efficiency Penallya
Cosf
($/joule)
Availability
(date)
Performance (% reduction)
COZ CO CH4 N2O NOx
Expressed as % of
combustion device
efficiency
Cost = 1985 $
' May be a benefit in some cases.
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all utility sources in various geopolitical
regions of the world. The Organization for
Economic Cooperation and Development
(OECO) has addressed global fuel con-
sumption and environmental issues, but
again the data available from the OECD do
not directly support the development of
source specific emission factors. The use of
source-specific U.S. data was generally re-
quired due to the absence of readily avail-
able data from international sources;
however, in many cases the U.S. data may
be globally representative of the energy-
specific emissions of the five greenhouse
gases considered in this study.
The emission factor quality ratings are
summarized in Figures 1 through 4 to indi-
cate the overall quality of this emission factor
database. The emission factors were given
quality ratings from A to E, with an A being
the best. Figure 1 shows that the distribution
of the ratings is fairly even; roughly 35% of
all emission factors are rated B or higher,
while about 39% are rated D or lower.
Figure 2 shows the percentage of the total
number of emission factors for each of the
fh/0 gases for which data were not readily
available. It shows that, in general, data
were readily available for NOX and CO. For
nearly all sources it was possible to calculate
COz emission factors using a carbon
balance. The carbon balance generally ac-
counts for the conversion of carbon in the
fuel to COa, CO, and ChU. In many cases,
the emission factors for COa are orders of
magnitude greater than for any other car-
bonaceous species. Therefore, it was pos-
sible to estimate with reasonable accuracy
COz emission factors for many sources for
which CO and/or CHU emission factors were
not available. For this reason, the percent of
COa emission factors for which data were
not readily available is less than the percent
of CO and CHU emission factors for which
data were not readily available.
Only limited data were readily available
from which to estimate NaO emission fac-
tors. For about 90% of the sources included
in this study, data were not available from
which to estimate an NaO emission factor.
Figure 3 indicates the overall quality of the
available emission factors for each of the five
gases. The rating of E for all NaO emission
factors reflects the lack of sufficient test data
from which to develop high quality emission
factors. The emission factors for CH4, many
of which were estimated based on a percent-
age of total hydrocarbon emissions,
generally have lower ratings than CO and
NOX emission factors. The emission factors
for Cm tend to be lower than NOX or CO
emission factors. The distributions of
ratings for NOX and CO emission factors are
fairly uniform. The emission factors for COa
were generally rated higher than the other
four gases, even though COa emission fac-
tors were generally calculated from a carbon
balance. COa represents the largest car-
bonaceous species emitted by most com-
bustion processes by several orders of
magnitude; therefore, uncertainty as-
sociated with the emissions of CO, CH-j, or
other carbonaceous species as gases or [
solids generally has a negligible impact on
the COa emission factor estimate and
rating.
Figure 4 shows the distribution of emis-
sion factor ratings for all gases for each
source category. Overall, the source
categories with the best emission factor
ratings are also the most significant emis-
sion sources. Utility and industrial boiler
sources have the best overall ratings. NaO
emission factors account for most of the E
ratings for these two sources. NOX and CO
emission factors in these two categories are
generally rated A and B. Most of the
transportation sources CI-U and NaO emis-
sion factors are rated D or lower. Kilns,
ovens, and dryers noticeably are rated the
lowest overall; only COa emission factors
are rated as high as B and C in the kilns
category. The emission factors for fuel
production sources are also generally of
lower quality than for other sources; ratings
of C and D are evenly distributed for COa,
NOX, CO, and CH4 emission factors.
The cost estimates are sensitive to the
assumptions made regarding capacity fac-
B's (17.0%)
C's (26.1%)
A's (18.3%)
E's (24.2%)
D's (14.4%)
Figure 1. Distribution of all emission factor quality ratings.
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tor when calculating annualized cost on an
energy basis. Costs are also sensitive to the
size of the facility being costed. When pos-
sible, reasonably representative source
capacities were selected. However, in many
cases, cost information was readily available
for only a single source capacity. Globally,
costs vary considerably due to differences
in labor costs, financing methods, inflation,
taxes, and regulations. The cost estimates
should be regarded as rough estimates that
indicate the relative cost of one technology
to another.
The emission factor quality ratings identify
some areas that could benefit from addition-
al research. Many more test data are re-
quired before NaO emission factors can be
developed for any sources with good con-
fidence. The applicability of U.S. data to
develop globally representative emission
factors, such as assuming that the design
and operation of source technologies in the
U.S. are the same as in other regions of the
world, requires further study. The identifica-
tion of significant differences in cost or per-
formance for emission sources from one'
region of the world to another would indicate
that emission source parameters should be
estimated independently for different
regions of the world. Additional study, and
possibly source testing, may be required to
fill gaps in the emission database and to
improve the quality of emission factors. The
impact of control technologies on NaO emis-
sions requires more testing.
Specific tasks for further development of
this database could include additional litera-
ture search, consultation with experts in the
U.S. and internationally, and source testing,
including the impact of control technologies
on NaO. Data from these activities could be
used to improve the accuracy of current
estimates, provide data where data are cur-
rently not included, and develop new emis-
sion source and control categories to
account for regional differences in perfor-
mance and cost.
100
i
§
I
90 -
40 -
30 -
20 -
10 -
COz
I
CO
CH4
Emission Compound
Figure 2. Percent of emission factors for each gas for which data were not readily available.
A/Ox
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TOO
90
80
70
60
SO
40
30
20
to
0
A's
I I**
I \C's
D's
e's
COz
CO
Figure 3. Distribution of emission factor ratings by gas.
CH4 AfeO
Emission Compound
NOx
70
GO
50
30
20
10
A's
I l<*
D's
E's
m
n
pTTf
Industrial Transportation Residential Commercial
Source Category
Kilns/Ovens/ Fuel Production
Dryers
Figure 4. Distribution of emission factor ratings by source.
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S. Piccot, J. Buzun, and C. Frey are with Radian Corporation, Research Triangle Park,
NC 27709
Julian W. Jones is the EPA Project Officer (see below)
The complete report, entitled "Emissions and Cost Estimates for Globally Significant
Anthropogenic Combustion Sources of NOX, NzO, CH4, CO, and CO2," (Order
No. PB 90-216 433/AS; Cost: $23.00, subject to change) will be available only
from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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