United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-84-059 June 1984
&EPA Project Summary
Methodology for
Development of an Independent
Combustion Source NOX
Inventory: And Its Application to
150 Counties in the Northeastern
United States
Michael F. Szabo and Paul W. Spaite
This study was performed to demon-
strate a new methodology for develop-
ing a combustion source fuel use and
emissions inventory. The demonstra-
tion area encompassed 150 counties
within a 200-mi (320-km) radius of the
Adirondack Mountains in New York
State, believed to be representative of
the Northeastern U.S.
A complete combustion inventory of
nitrogen oxides (NOX) emissions was
developed for the 150 counties. All
sectors (residential, commercial, trans-
portation, utility, and industrial) were
included. In the industrial sector, the
methodology entailed: (1) identifying
all major combustion processes and
associated equipment, and (2) develop-
ing NO. emission factors. This approach
produced a list of 28 facilities and 73
processes, believed to include all signif-
icant combustion sources in the 150-
county study area. An approach was
also developed for treating all fuel con-
sumption not accounted for by installa-
tions that include major combustion
processes. The latter block of fuel con-
sumption was translated into "resi-
dual" industrial area source NO« emis-
sions.
As intended, the project demonstrated
fully the essential elements of a meth-
odology that would allow development
of county-by-county NOX inventory for
all fuel burning in all or any part of the
U.S., without resorting to user surveys
or inventories based on such surveys.
The data base it establishes also can be
used to calculate other combustion-
related emissions.
Although the procedures of this
methodology were not fully optimized
in this study, they are straightforward,
well documented, and easily modified
as new data are uncovered.
Study results showed that area
sources account for 92 percent of the
fuel consumption (excluding utilities)
and 64 percent of NO* emissions
(including utilities) in the study area.
Transportation is the dominant contri-
butor. Boilers are the dominant point
sources of NOX emissions, and residual
oil accounts for 52 percent of the
industrial boiler fuel burned in this area.
This Pro/act Summary was developed
by EPA's Industrial Environmental
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering
information at back).
Introduction
By the late 1960s, the most significant
sources of major air pollutants such as
NOX and sulfur oxides (SO*) had been
identified and put in some perspective;
however, no data bank contained inform-
ation on the size, location, type and
amount of pollution, and other impact
factors for all major air pollution sources.
-------
In the late 1960s and early 1970s, work
began on developing a comprehensive
inventory. The Clean Air Act of 1970 gave
impetus to this effort, resulting in EPA's
establishment of the National Emissions
Data System (NEDS), a data bank contain-
ing information on pollutant discharges
from all types of area and point sources.
Most of the data in this computerized data
base are generated by state agencies.
Data quality is a function of the resources
available to the states for collection of
information from facilities that generate
pollution. Although the imput data are
screened to some extent, the accuracy of
the various data has not been well
defined. Some users believe that data for
certain components (e.g., utilities, and
iron and steel plants) are well documented;
whereas, data for other smaller compo-
nents (e.g., foundries and industrial
boilers) are not.
Asa result, in the past several years the
need for better and more comprehensive
regional and local inventories has been
considered in several quarters. For
example, the data base for industrial and
commercial boilers is thought to be
inadequate in light of the pollution
problem they are now believed to present.
This study was performed to demon-
strate another methodology for develop-
ing a combustion source and emissions
inventory. The approach was novel in that
is was not based primarily on field
investigation or survey data. Instead, fuel
use information and industrial statistics
published by government and industry
groups were used to identify fuel-
consuming facilities and to estimate their
emissions of NOX. It was hoped that the
project would show the feasibility of an
inventory that was neither subject to the
errors inherent in those based on
surveys, nor as costly as those involving
field verification.
A study area encompassing 150
counties within a 200-mi (320-km) radius
of the Adirondack Mountains in New York
State (Figure 1) was chosen to demon-
strate this approach to developing a com-
bustion source fuel use and emissions in-
ventory.
General Approach
This study's approach to residential,
commercial, and transportation sectors
was straightforward in that these sectors
were treated as traditional area sources
(mobile or small and widely dispersed,
such as automobiles and residential
furnaces), and an accepted methodology
was used to compute energy consumption
on a county-by-county basis. Because it is
LAKE ERIE
SLAND
200 mi. (320 km)
Figure 1. The 150-county study area (shaded).
already extensively documented, the
utility sector also presented few problems.
The industrial sector, which has tradi-
tionally been the most difficult to assess,
was systematically analyzed to provide a
better overall perspective of the combus-
tion sources in that sector.
For the residential and commercial
sectors, it was assumed that fuel use was
proportional to population, and the sector
fuel consumption for individual states was
prorated to individual counties. County
fuel use data were then converted to NOX
emissions, using emisson factors devel-
oped from analyzing fuel burning practices
in the sector.
The transportation sector includes
liquid fuels used in motor vehicles and
natural gas used in pipeline transport of
fuel. The combustors involved in pipeline
transport (internal combustion engines
and gas turbines) were not broken down
to the county level, however. Consumption
of liquid fuels was assumed to be
proportional to the number of registered
motor vehicles in the individual counties.
Emission factors were derived by ana lysis
of information on emissions from various
types of motor vehicles, and area NOX
emissions were estimated by county.
Because the type and amount of fuel
used, types and locations of combustors,
etc., are well documented for the utility
sector, demonstration of the ability to
generate county-by-county emission
inventories for this sector was deemed
unnecessary for this study.
The industrial sector presented the
biggest challenge. Prior to this study, this
sector had never been systematically
investigated to identify major combustion
sources. Because this sector uses fuel in
major direct-fired processes, large indus-
trial boilers, and a wide variety of smaller
combustors (e.g., stationary internal
combustion engines, gas turbines, ovens,
and dryers), a more complex approach
was required.
The analysis of industrial sector NOX
emissions began with a systemat
evaluation of specific blocks of fu
burning that make up the total fo
-------
industrial combustion. The major blocks
of fuel combustion are well defined and
documented in the literature, which
served as a source of the analysis.
The combustion hardware was more
clearly defined by systematic analyses
that divided all industrial fuel burning into
that burned by identifiable "major point
sources" (estimated by fuel consumption
of at least 100 x 109 Btu (or kJ /yr) and
that consumed by area sources. This
classic approach, consistent with the
NEDS treatment, allows direct compari-
sons to be made despite using an
independent approach.
Because no previous study defined the
total population of point sources, a search
based on all the "industries" (defined for
the manufacturing sector in the Census
of Manufacturers) was undertaken as an
important part of the industrial fuel
analysis. As a first step, the Standard
Industrial Classification (SIC) code indus-
tries represented by 4-digit codes in the
Census data bank were screened to
eliminate all those with a total annual
fuel use of less than 100 x 109 Btu/estab-
lishment. It was assumed that this limit
would prevent overlooking any major
direct-fired point sources in the industries
with low average annual fuel consump-
tion. The industries eliminated by this
formula were reviewed to determine if
this was a correct assumption.
At the beginning of the analysis of the
industrial sector, a decision also was
made not to include industries in which
fuel consumption could be attributed
principally to boilers or foundries. Because
of their numbers and widely varying sizes,
these were to be the subject of an
independent analysis. Industries that
involved assembly line work where space
heat requirements were high were also
excluded. Together, these two screening
criteria reduced the total number of
industries for further investigation from
450 to 114.
The final group of 114 industries were
investigated to identify direct-fired
processes that were considered to be
major point sources (because of fuel use
estimated to be over 100 x 109 Btu/yr), to
identify the establishments where these
direct-fired processes were employed,
and to estimate the amount of fuel used
and the resulting NOX emissions.
In the end, a list of 28 types of facilities
employing 73 types of processes was
developed for the 150-county study area
(Table 1). These processes, together with
foundries and industrial boilers, are
^believed to present the most complete
Hefinition of the population of fuel-
*consuming industrial processes that had
been developed up to the time the list was
completed.*
Analysis of industrial boilers with heat
input of >250 x 106 Btu/h was based on
existing data bases such as NEDS, the
U.S. Department of Energy's (DOE's)
Major Fuel Burning Installation (MFBI)
survey, and PEDCo in-house data accu-
mulated during plant visits connected
with DOE projects.
After the major industrial point sources
and the large boilerst, had been identified,
the sum of the fuel consumption for these
point sources was subtracted from the
total industrial fuel consumption reported
by the Department of Energy. The balance
of the industrial energy consumption was
then treated in a manner similar to that
used for the residential, commercial, and
transportation sectors. Fuel consumption
and NOX emission estimates were then
generated for the following categories:
Area sources
Point sources
Residential sector
Commercial sector
Transportation sector
Industrial nonpomt sources
Industrial boilers
Electric utilities
Direct-fired processes
Applying the Methodology to
the Study Area
The methodology was applied to the
study area in four steps:
1) Identification and location of major
point sources.
2) Development of fuel consumption
estimates for major point sources.
3) Development of fuel consumption
estimates for area sources.
4) Determination of emission factors
and calculation of emissions for point
and area sources.
Although the study area represents a
limited fraction of the total country, the
results produced are of interest beyond
their usefulness in demonstrating the
methodology. In general, the identified
direct-fired sources and boilers accounted
for a surprisingly small percentage of
total industrial fuel consumption (30
percent in the study area). Thus, "residual"
industrial energy usage (classified as
area source consumption) is sizable,
ranking third in the categories of emis-
sions (behind transportation and electric
utilities) for the study area.
'Work subsequent to that reported here has
expanded the group of establishments to 45 and the
group of processes to 100. For the most part, these
processes are very close to the estimated fuel con-
sumption limit of 100 x 109 Btu.
tOnly 25-MW or larger boilers were considered in
this study; however, given sufficient resources,
boilers in the 10- to 25-MW range probably could
be inventoried with reasonable accuracy by this
same approach.
When comparing the results of this
study, remember that utility emissions
are included in the NOX totals, but utility
fuel consumption is not part of the fuel
total. Study results showed that area
sources are the major contributors to NO*
emission in the study area. These sources
accounted for 64 percent of total NO*
emissions (excluding utilities). Transpor-
tation was the dominant contributor (48
percent), but the combined total for the
residential and commercial sectors was
significant (about 10 percent). Area
sources also accounted for 92 percent of
the fuel consumed in this study area
(excluding utilities).
Among industrial point sources, boilers
were the dominant emitter of NOX
emissions, and residual oil accounted for
52 percent of the industrial boiler fuel
use.
Table 2 summarizes point and area
source NO* emissions in the study area.
Table 3 compares the results of this
methodology with NEDS data covering
the same area.
Conclusions
The methodology for developing a
major point source combustion population
(i.e., the use of Standard Industrial
Classification Codes) was judged to be
successful. The resulting list of 28
facilities and 73 processes is believed to
include combustion sources of any
consequence in the 150-county area.
The straightforward well-documented
methodologies developed for calculating
plant production, direct-fired fuel con-
sumption, and NOX emissions do not rely
primarily on survey data from state
agencies. Although these procedures
were not optimized in this study, they can
be easily modified as new data are
uncovered.
In contrast, the procedures used to
calculate industrial boiler fuel consump-
tion and NOX emissions rely heavily on
NEDS and other completed studies.
Although these sources could be used to
identify boilers smaller than the 25-MW
equivalent used for this study, the data
base for industrial boilers is generally
weaker than that for other important
stationary sources, a situation that will
prevail until a well-conceived survey of
the existing boiler population is conducted.
The methodology for calculating "resi-
dual" industrial fuel consuming sources
and NO* emissions needs more work. If a
study included individual states in their
entirety, data from the State Energy Data
Base and the Census of Manufacturers
could be combined to provide a better
-------
Table 1. List of Major Fuel-Consuming Facilities and Processes
Facility*
Process'
Facility
Process
Petroleum refineries
Petrochemical plants
Industrial organic
chemical plants
Industrial inorganic
chemical plants
Atmospheric distillation
Vacuum distillation
Thermal operation
Catalytic cracking
Catalytic reforming
Hydrocracking
Hydrorefining
Alky lat ion
Aromatic manufacturing
Ammonia (steam hydrocarbon
reforming)
Benzene, toluene, xylene
Butadiene (naphtha cracking)
Carbon black (oil furnace
process)
Ethanol (naphtha cracking)
Ethylene/propy/ene (naphtha
cracking)
Methanol (low pressure)
Dimethyl terephthalate
(Dynamit Nobel)
Styrene
(Monsanto)
Borax (drying)
Lithium hydroxide (calcina-
tion)
Sodium carbonate (mono-
hydrate)
Diatomite plants
Mineral wool plants
Integrated iron and
steel plants
Mini and midi iron
and steel plants
Iron foundries
Copper smelters and
refineries
Lead smelters and
refineries
Zinc smelters and
refineries
Drying/calcination
Melting
Sintering
Coking
Steelmaking
Melting
Slabbing/blooming
Melting
Slabbing/blooming
Melting
Smelting
Roasting
Cathode melting
Arsenic oxide (roasting)
Sintering
Smelting
Softening
Desilverizing
Debismuthing
Refining
Roasting
Sintering
Electrothermic reduction
Secondary materials pre-
paration
Phosphate rock and basic
fertilizer plants
Pulp mills
Gypsum plants
Lime plants
Brick and tile plants
Lightweight aggregate
plants
Cement plants
Container glass plants
Flat glass plants
Pressed and blown glass
plants
Potash (calcination)
Potash (drying)
Potash (leaching)
Sodium phosphate (fusion/
calcination)
Sodium phosphate (crystalli-
zation/drying)
Kraft
Dry ing/ calcination
Calcination
Firing
Expansion
Wet and dry
Melting
Melting
Melting
Titanium smelters
Tin smelters
Magnesium smelters
Aluminum smelters
Copper smelters and
refineries
Lead smelters
Aluminum sheet.
plate, and foil plants
Chlorination
Reduction
Leaching
Drying
Smelting
Calcination
Sweating
Smelting
Sweating
Smelting
Refining
Smelting
Melting
Heat treating
"The order in which facilities and processes are listed reflects the authors' logical grouping of the industries, with respect to their relation to each other.
perspective of the residual component of
industrial fuel consumption.
The methodology reported here is
flexible and easily modified. This strength
has already been demonsrated in that the
methodology has been further refined
since this project was concluded.
-------
Table 2. Summary of Point and Area Source NO* Emissions in the 150-County Study Area (103 short tons or 9.1 x 10s kg f
Area Sources Point sources
/VO, total
Traditional
Industrial
State
Connecticut
Massachusetts
New Hampshire
New Jersey
New York
Pennsylvania
Rhode Island
Vermont
Study area total
(D
Transpor-
tation
71,7
118.7
21.3
161.9
274.9
117.4
20.2
15.1
801.2
(2)
Residen-
tial
8.3
13.6
1.8
12.2
31.8
8.8
2.6
1.3
80.4
13)
Commer-
cial
3.9
10.9
0.4
16.5
42.7
4.6
1.2
0.3
80.5
(4)
Industrial
residual
13.0
8.8
0.7
9.4
12.2
51.7
1.6
1.1
98.5
(51
Boilers
1.2
1.1
0.4
2.6
34.2
4.3
0.1
0
43.9
(6)
Direct
fired
1.3
0.8
1.1
9.3
16.3
23.6
0.2
0
52.6
(7)
Electric
utility
33.4
78.3
12.2
55.4
191.9
124.5
2.1
0.1
497.9
Industrial
4, 5, and 6
15.5
10.7°
2.2
21.3C
62.T6
79.6s
1.9
1.1
195.0
Area 1. 2.
3, and 4
96.9
152.0
24.2
200.0
361.6
182.5
25.6
17.8
1060.6
Point 5,
6. and 7
35.9
80.2
13.7
67.3
242.4
152.4
2.4
0.1
594.4
State
total
132.8
232.2
37.9
267.3
6O4.O
334.9
28.0
17.9
1655.0
'Based on 1978 data.
hValue is 97 percent of 1978 state total based on the population of the counties included in the analysis.
cVafue is 84 percent of 1978 state total based on the population of the counties included in the analysis.
"Value is 97 percent of 1978 state total based on the population of the counties included in the analysis.
'Value is 33 percent of 1978 state total based on the population of the counties included in the analysis.
Table 3. Comparison of NO* Emissions Estimates for the ISO-County Study Area with 1980
NEDS" Values
/VO« estimates. 103 tons (9.1 x 105 kgl/yr
Emission source
Mobile source fuel combustion
Highway vehicles
Stationary source fuel combustion
Electric generation
Industrial (boilers and residual sources)
Residential/ commercial/ institutional
Industrial processes and combustion
Chemicals
Petroleum refining
Metals
Mineral products
Wood products
Other
Mobile source subtotal
Stationary source subtotal
Total
1980 NEDS values
894.1
423.7
194.2
168.6
24.8
(3.36)
(3.07)
(2.69)
(11.65)
(0.25)
(3.81)
894.1 (52.4%)
811.3(47.6%)
1705.4
This study
801.2
497.9
142.4
160.9
52.6
(0.3)
(5.1)
(26.4)
(19.4)
(1.3)
(0.0)
801.2(48.4%)
853.8(51.6%)
1655.0
8 EPA's National Emissions Data System.
M. F. Szabo is with PEDCo Environmental, Inc., Cincinnati, OH 45246; and P. W.
Spaite is with Paul W. Spaite Co., Cincinnati, OH 45213.
Joshua S. Bo wen is the EPA Project Officer (see below).
The complete report, entitled "Methodology for Development of an Independent
Combustion Source /VO« Inventory: And Its Application to 150 Counties in the
Northeastern United States." (Order No. PB 84 189 943; Cost: $ 19.00, 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:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
6USGPO: 1984-759-102/10609
-------
United Slates Center for Environmental Research
Environmental Protection Information
Agency Cincinnati OH 45268
Official Business
Penalty for Private Use $300
------- |