COMPILATION
OF
AIR POLLUTANT EMISSION FACTORS
(Revised)
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air Programs
Research Triangle Park, North Carolina
February 1972
For gale by the Superintendent of Documents, U.S. Government Printing OMoe, Washington, D,C, 20402 - Price $1,80
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The AP Series of reports is issued by the Environmental Protection Agency to
report the results of scientific and engineering studies, and information of general
interest in the field of air pollution. Information presented in this series includes
coverage of intramural activities involving air pollution research and control
technology and of cooperative programs and studies conducted in conjunction with
state and local agencies, research institutes, and industrial organizations.
Copies of AP reports are available free of charge - as supplies permit - from the
Office of Technical Information and Publications, Office of Air Programs,
Environmental Protection Agency, Research Triangle Park, North Carolina 27711.
Office of Air Programs Publication No. AP-42
2/72 ii
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PREFACE
This document reports available atmospheric emission data for which
sufficient information, exists to establish realistic emission factors. Although
based on Public Health Service Publication 999-AP-42, Compilation of Air Pollutant
Emission Factors, by R. L>. Duprey, this document has been expanded and revised
considerably and supercedes the previous report. The scope of the document has
been broadened to reflect expanding knowledge of emissions,
As data are refined and additional information becomes available, this docu-
ment will be reissued or revised as necessary to reflect more accurate and refined
emission factors. New processes will be included in future supplements. The
loose-leaf form of this document is designed to facilitate the addition, of future
materials.
Comments and suggestions regarding this document should be directed to the
attention of Director, Applied Technology Division, SSPCP, OAP, EPA, Research
Triangle Park, North Carolina 27711.
2/72 ill
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ACKNOWLEDGMENTS
Because this document is a product of the efforts of many individuals, it is
impossible to acknowledge each individual who has contributed. Special recognition
is given, however, to Mr. Richard. Gerstle and the staff of Resources Re.search,
Inc. , who provided a large part of the efforts that went into this document. Their
complete effort is documented in their report for contract number CPA-22-69-H9.
Environmental Protection Agency .employees M. J. McGraw, A, J. Hoffman,
J. H. Souther land, and R. L. Duprey are also acknowledged for their efforts in
the production of this. work.
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CONTENTS
Page
LIST OF FIGURES x
LIST OF TABLES xi
ABSTRACT xv
INTRODUCTION . , 1
1. STATIONARY COMBUSTION SOURCES 1-1
BITUMINOUS COAL COMBUSTION 1-1'
General Information 1-1
Emissions and Controls 1-1
ANTHRACITE COAL COMBUSTION 1-4
General 1-4
Emissions and Controls 1-4
FUEL OIL COMBUSTION 1-4
General Information .,.....,, 1-4
Emissions 1-6
NATURAL GAS COMBUSTION 1-6
General Information ..,..,.,,...,....... 1-6
Emissions and Controls 1-6
LIQUEFIED PETROLEUM GAS CONSUMPTION 1-8
General Information 1-8
Emissions , , 1-8
WOOD WASTE COMBUSTION IN BOILERS 1-8
General Information , ,..,,, 1-8
Firing Practices . . 1-8
Emissions 1-11
REFERENCES FOR CHAPTER 1. . 1-12.
2. SOLID WASTE DISPOSAL 2-1
REFUSE INCINERATION 2-1
Process Description 2-1
Definitions of Incinerator Categories 2-1
Emissions and Controls , 2-2
AUTOMOBILE BODY INCINERATION 2-3
Process Description , 2-3
Emissions and Controls , , . . , 2-3
CONICAL BURNERS 2-5
Process Description 2-5
Emissions and Controls 2-5
OPEN BURNING 2-5
General Information 2-5
Emissions .,...,, , 2-6
REFERENCES FOR CHAPTER 2 2-8
3. MOBILE COMBUSTION SOURCES 3-1
GASOLINE-POWERED MOTOR VEHICLES 3-1
General 3-1
Emissions 3-3
Exhaust Emissions 3-5
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Page
DIESEL-POWERED MOTOR VEHICLES 3-5
General 3-5
Emissions 3-6
AIRCRAFT (SIC 45--) 3-6
General , , . •. 3-6
Emissions. » . . , . 3-7
VESSELS (SIC 44--) .......... 3-8
General 3-8
Emissions , 3-8
REFERENCES FOR CHAPTER 3 3-12
4. EVAPORATION LOSS SOURCES 4-1
DRY CLEANING 4-1
General 4-1
Emissions and Controls ..,,-... 4-1
SURFACE COATING 4-2
Process Description 4-2
Emissions and Controls , 4-2
PETROLEUM STORAGE 4-2
General 4-2
Emissions . 4-3
GASOLINE MARKETING 4-3
General , . , 4-3
Emissions and Controls . ^ , , '...,,..... 4-4
REFERENCES FOR-CHAPTER 4. 4-5
5. CHEMICAL PROCESS INDUSTRY 5-1
ADIPIC ACID (SIC 2818) 5-1
Process Description ...,,,,. , . 5-1
Emissions 5-1
AMMONIA {SIC 2819) 5-2
Process Description . , 5-2
Emissions and Controls 5-2
CARBON BLACK (SIC 2895) 5-2
Channel Black Process 5-2
Furnace Process .'..,....,.,. 5-3
Thermal Black Process • 5-3
' CHARCOAL (SIC 2861. 5-4
Process Description . . . 5-4
Emissions and Controls ,...'..'..., 5-5
CHLOR-ALKALI (SIC 2812) 5-5
Process Description , • 5-5
Emissions and Controls 5-6
EXPLOSIVES (SIC 2892) ' 5-6
General 5-6
TNT Production . 5-7
Nitrocellulose 5-7
Emissions 5-7
HYDROCHLORIC ACID (SIC E819) , . . . . . 5-7
Process Description 5-8
Emissions 5-8
HYDROFLUORIC ACID (SIC 2819) 5-9
Process Description . , 5-9
Emissions and Controls , 5-9
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Page
NITRIC ACID (SIC 2819). ......,..,., 5-10
Process Description , 5-10
Emissions. . . .5-10
PAINT AND VARNISH (SIC 2851) , 5-10
Paint 5-10
Varnish 5-11
PHOSPHORIC ACID (SIC 2819) 5-11
Wet Process 5-12
Thermal Process 5-12
PHTHALIC ANHYDRIDE (SIC 2815) 5-13
Process Description 5-13
Emissions and Controls. ....5-13
PLASTICS (SIC,2821) 5-13
Process Description ...,,,.. 5-13
Emissions and Controls. 5-14
PRINTING INK (SIC 2893) • 5-14
Process Description . 5-14
Emissions and Controls. .....,.,.., 5-15
SOAP AND DETERGENTS (SIC 2841) 5-16
Soap 5-16
Detergents 5-16
SODIUM CARBONATE (SIC 2812) 5-16
Process Description 5-16
Emissions 5-17
SULFURIC ACID (SIC 2819) . 5-1?
Process Description 5-17
Elemental Sulfur-Burning Plants 5-17
Sulfide Ore and Smelter Gas Plants 5-18
Spent-Acid and Hydrogen Sulfide Burning Plants 5-18
Emissions , -. ... 5-18
SYNTHETIC FIBERS (SIC 282-) 5-18
Process Description 5-18
Emissions and Controls. 5-19
SYNTHETIC RUBBER (SIC 2822) 5-20
Process Description 5-20
Emissions and Controls. 5-20
TEREPHTHALIC ACID (SIC 2818) 5-20
Process Description 5-20
Emissions 5-21
REFERENCES FOR CHAPTER, 5 5-22
6, FOOD AND AGRICULTURAL INDUSTRY . 6-1
ALFALFA DEHYDRATING (SIC 2042). 6-1
General 6-1
Emissions and Controls. 6-1
COFFEE ROASTING (SIC 2095) 6-2
Process Description 6-2
Emissions,,...,., 6-2
COTTON GINNING 6-3
General 6-j
Emissions and Controls 6-3
FEED AND GRAIN MILLS AND ELEVATORS (SIC 204-) 6-3
General, ................ 6-3
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Page
Emissions • . . , . -6-4
FERMENTATION (SIC 208-5, , . . . . '. .. 6-5
. General Process Description .'..,. 6-5
Emissions, .,,.,.,,.. ,..,...., 6-5
FISH PROCESSING (SIC 2042)' . , . . 6-6
Process Description .,..,,,.,,. •...-.. 6-6
Emissions and Controls .,;.,' 6-6
MEAT SMOKEHOUSES (SIC 2011) ."....-..,.....'....' 6-7
• Process Description ..-.....'. 6-7
Emissions and Controls , ....... 6-7
NITRATE FERTILIZERS (SIC 2871) 6-7
General 6-7
• Emissions and Controls-. ......'.,.• '. , . 6-8
PHOSPHATE FERTILIZERS (SIC 2871) '..... 6-8
NORMAL SUPERPHOSPHATE (SIC 2871) . , •. . -. . . . '. . ,--\ . . 6-9
• General ..:.., 6-9-
Emissions, ' :' , . .''.', 6-10
TRIPLE SUPERPHOSPHATE (SIC 2871). ...... 6-10
General •." .,..-.•.... 6-10
Emissions 6-11
AMMONIUM PHOSPHATE (SIC 2871) ..'..., 6-11
General '. . ,. . . . •. . . , . . . .... 6-11
Emissions, '. .'. .-.., . . . 6-11
STARCH MANUFACTURING (SIC 2046) . . ...... 6-11
General Process Description ...........6-11
Emissions • . ,- , . . ... . . 6-12
SUGAR CANE PROCESSING (SIC 2061) 6-12
General .,.'.. . .• . 6-12
Emissions, 6-12
REFERENCES FOR CHAPTER 6.- , . . . 6-13
7. METALLURGICAL INDUSTRY . . . - 7-1
PRIMARY METALS INDUSTRY . . ". 7-1
Aluminum Ore Reduction (SIC 3334) • , , . 7-1
Metallurgical Coke Manufacturing (SIC'3312) -. .... .. 7-2
Copper Smelters (SIC 3331) ....... 7-3
Ferroalloy Production (SIC 3313) ........... k . . . 7-3
Iron and Steel Mills (SIC 3312) . '..... 7-6
Lead Smelters (SIC 3332) 7-8
Zinc Smelters (SIC 3333) - 7-8
. SECONDARY METALS INDUSTRY ........ 7-8
Aluminum Operations (SIC 3341) .'..... 7-8
Brass and Bronze Ingots (SIC 3341) 7-11
Gray Iron Foundry (SIC 3321) . , 7-12
Secondary Lead Smelting (SIC 3341) . . , . .'. . . . . . •'. . . 7-13
Secondary Magnesium Smelting (SIC 3341).- •. 7-14
Steel Foundries (SIC 3323) .'7-14
Secondary Zinc Processing (SIC 3341) .............. 7-17
REFERENCES FOR. CHAPTER 7 .-. . 7.-18
8. • MINERAL PRODUCTS INDUSTRY . - . 8-1
ASPHALT BATCHING (SIC 2951) . .....' 8-1
Process Description , , - ,-,,..-., 8-1
Emissions and Controls. 8-1
vW 2/72
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Page
ASPHALT ROOFING (SIC 2952) 8-1
Process Description • 8-1
Emissions and Controls « 8-2
BRICKS AND RELATED CLAY PRODUCTS (SIC 325-) 8-3
Process Description 8-3
Emissions and Controls . ,..,.., 8-3
CALCIUM CARBIDE MANUFACTURING (SIC 2819) 8-4
Process Description 8-4
Emissions and Controls • 8-4
'CASTABLE REFRACTORIES (SIC 3297} 8-5
Process Description 8-5
Emissions and Controls 8-5
PORTLAND CEMENT MANUFACTURING (SIC 3241) • 8-5
Process Description 8-5
Emissions and Controls « 8-6
CERAMIC CLAY MANUFACTURING (SIC 3251) . 8-7
Process Description . 8-7
Emissions and Controls . 8-7
CLAY AND FLY-ASH SINTERING 8-8
Process Description 8-8
Emissions and Controls 8-8
COAL CLEANING • • • - 8-9
Process Description 8-9
Emissions and Controls 8-10
CONCRETE BATCHING (SIC 3273) 8-10
Process Description 8-10
Emissions and Controls 8-10
FIBER GLASS MANUFACTURING (SIC 3229) 8-11
Process Description 8-11
Emissions and Controls ,..,,....... 8-11
FRIT MANUFACTURING (SIC 2899) 8-12
Process Description 8-12
Emissions and Controls , 8-12
GLASS MANUFACTURING (SIC 3211) 8-13
Process Description .,....' 8-13
Emissions and Controls . 8-13
GYPSUM MANUFACTURING (SIC 3295) 8-14
Process Description 8-14
Emissions 8-14
LIME MANUFACTURING (SIC 3274) . 8-14
General 8-14
Emissions and Controls 8-14
MINERAL WOOL MANUFACTURING (SIC 3296) - 8-15
Process Description 8-15
Emissions and Controls 8-15
PERLITE MANUFACTURING (SIC 3295) 8-16
Process Description 8-16
Emissions and Controls 8-16
PHOSPHATE ROCK PROCESSING (SIC 3295) 8-17
Process Description 8-17
Emissions and Controls. 8-17
STONE QUARRYING AND PROCESSING (SIC 3295) 8-17
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Page
Process Description 8-17
Emissions . , 8-18
REFERENCES FOR CHAPTER 8 8-19
9. PETROLEUM INDUSTRY 9-1
PETROLEUM REFINERY (SIC 2911) 9-1
General ,..,,...,, 9-1
Emissions 9-2
REFERENCE FOR CHAPTER 9 ,.,.,»,,...,.,,,. 9-2
10. WOOD PROCESSING 10-1
WOOD PULPING (SIC 2611) 10-1
General . .- 10-1
Process Description , 10-1
Emissions and Controls .,...,,....10-2
PULPBOARD (SIC 2611) 10-2
General 10-2
Process Description. , 10-2
Emissions 10-4
REFERENCES FOR CHAPTER 10 10-4
APPENDIX '. . ...... A-l
REFERENCES FOR APPENDIX ' A-8
LIST OF FIGURES
Figure Page
3-1 Speed Adjustment Graphs for Carbon Monoxide Emission
Factors ...,., 3-3
3-2 Speed Adjustment Graphs for Hydrocarbon Exhaust Emission
Factors , , 3-4
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LIST OF TABLES
Table Page
1-1 Range of Collection Efficiencies for Common Types of Equipment :
for Fly-Ash Control . • 1-2
1-2 Emission Factors for Bituminous Coal Combustion Without
Control Equipment ..,.,,,,.,.,..,.....,,.... 1-3
1-3 Sulfur Dioxide Removal from Various Types of Processes ...... 1-4
1-4 Emissions from Anthracite Coal Combustion Without Control
Equipment ., 1-5
1-5 Emission Factors for Fuel Oil Combustion 1-7
1-6 Emission Factors for Natural-Gas Combustion ,. 1-9
1-7 Emission Factors for LPG Combustion ,.,., 1-10
1-8 Emission Factors for Wood and Bark Combustion in Boilers
with No Reinjection 1-11
2-1 Collection Efficiencies for Various Types of Municipal
Incineration Particulate Control Systems 2-3
2-2 Emission Factors for Refuse Incinerators Without Controls 2-4
2-3 Emission Factors for Auto Body Incineration , 2-5
2-4 Emission Factors for Waste Incineration in Conical Burners
Without Controls. 2-6
2-5 Emission Factors for Open Burning . » 2-7
3-1 Emission Factors for Gasoline-Powered Motor Vehicles 3-2
3-2 Emission Factors for Diesel Engines .....,..,,.,.,.., 3-7
3-3 Aircratt Classification System. ..,.,,..,,,.,.,,.... 3-8
3-4 Emission Factors for Aircraft 3-9
3-5 Fuel Consumption Rates for Various Types of Aircraft During
Landing and Take-Off Cycle 3-10
3-6 Fuel Consumption Rates for Steamships and Motor Ships ....... 3-11
3-7 Emission Factors for Vessels 3-11
4-1 Hydrocarbon Emission Factors for Dry-Cleaning Operations. .... 4-2
4-2 Gaseous Hydrocarbon Emission Factors for Surf ace-Coating
Applications 4-3
4-3 Hydrocarbon Emission Factors for Evaporation Losses from
the Storage of Petroleum Products 4-4
4-4 Emission Factors for Evaporation Losses from Gasoline
Marketing , 4-5
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Table .Page
5-1- Emission Factors for an-Adipic Acid Plant Without Control
Equipment «»..,.,...,..,,...,,....,,,.... 5-1
5-2 Emission Factors for Ammonia Manufacturing Without Control
• Equipment .,,.,,..'.., , •.'....• 5-3
5-3 Emission Factors for Carbon Black Manufacturing .......... 5-4
5-4 Emission Factors for Charcoal'Manufacturing . . . , , 5-5
5-5 , Emission Factors for Chlor-Alkali Plants. .......... .... ..... . 5-6
5-6 ' Emission Factors for Explosives Manufacturing Without
Control Equipment -...,.., 5-8
5-7 Emission Factors for Hydrochloric Acid Manufacturing ........ 5-9
5-8 Emission Factors for Hydroflurolc Acid Manufacturing ',,.,... 5-9
5-9 Emission Factors for Nitric Acid Plants Without Control
Equipment ,.:,.,.. 5-10
5-10' Emission Factors for Paint and Varnish Manufacturing
Without Control Equipment 5-11
• 5-11 Emission Factors for Phosphoric Acid Production 5-12
5-12 Emission Factors for Phthalic Anhydride Plants . . . 5-13
5-13 Emission Factors for Plastics Manufacturing Without Controls "... 5-14
5-14 Emission Factors for Printing Ink Manufacturing. .,.•.....,-. 5-15
5-15 Particulate Emission Factors for Spray-Drying Detergents . , . v . 5-16
5-16-- Emission-Factors for Soda-Ash. Plants Without Controls ......... 5-17
5-17 Emission Factors for Sulfur ic Acid Plants. '..,... 5-19
5-18 Emission Factors for Synthetic Fibers Manufacturing . . .-. ."'.. , , . 5-20
5-19 Emission Factors for Synthetic Rubber Plants: Butadiene-.
Acrylonitrile and Butadiene-Styrene 5-21
5-20 Nitrogen Oxides Emission Factors for Terephthalic Acid- Plants ...... .5-21
6-1 Particulate Emission Factors for Alfalfa Dehydration 6-1
6-2 Emission Factors for Roasting Processes Without Controls . . v . . 6-2
6-3 Emission Factors for Cotton Ginning Operations Without Controls. .. 6-3
6-4 Particulate Emission Factors'for Grain Handling and Processing , . 6-4
6-5 Emission Factors for_ Fermentation Processes ,,,.....,,.. 6-6
6-6 Emission Factors for Fish Meal Processing ,,.;,... 6-7
6-7 - Emiseion Factors-for Meat Smoking 6-8
6-8 Emission Factors for Nitrate Fertilizer Manufacturing
Without-Controls. ........................... 6-9
6-9 Emission Factors for the Production of Phosphate Fertilizers ... >.• . . 6-10
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Table Page
6-10 Emission Factors for Starch Manufacturing. 6-12
6-11 Emission Factors for Sugar Cane Processing 6-13
7-1 Emission Factors for Aluminum Ore Reduction Without Controls . 7-2
7-2 Emission Factors for Metallurgical Coke Manufacture Without
Controls 7-4
7-3 Emission Factors for Primary Copper Smelters Without Controls. . 7-5
7-4 Emission Factors for Ferroalloy Production in Electric Smelting
Furnaces 7-6
7-5 Emission Factors for Iron and Steel Mills Without Controls ..... 7-9
7-6 Emission Factors for Primary Lead Smelters ............ 7-10
7-7 Emission Factors for Primary Zinc Smelting Without Controls . . . 7-10
7-8 Particulate Emission Factors for Secondary Aluminum Operations . 7-11
7-9 Particulate Emission Factors for Brass and Bronze Melting
Furnaces Without Controls 7-12
7-10 Emission Factors for Gray Iron Foundries ......7-13
7-11 Emission Factors for Secondary Lead Smelting 7-15
7-12 Emission Factors for Magnesium Smelting 7-16
7-13 Emission Factors for Steel Foundries .7-16
7-14 Particulate Emission Factors for Secondary Zinc Smelting 7-17
8-1 Particulate Emission Factors for Asphalt Batching Plants 8-2
8-2 Emission Factors for Asphalt Roofing Manufacturing Without
Controls , 8-3
8-3 Emission Factors for Brick Manufacturing Without Controls ..... 8-4
8-4 Emission Factors for Calcium Carbide Plants 8-5
8-5 Particulate Emission Factors for Castable Refractories
Manufacturing 8-6
8-6 Particulate Emission Factors for Cement Manufacturing 8-7
8-7 Particulate Emission Factors for Ceramic Clay Manufacturing ... 8-8
8-8 Particulate Emission Factors for Sintering Operations ........ 8-9
8-9 Particulate Emission Factors for Thermal Coal Dryers ....... 8-10
8-10 Particulate Emission Factors for Concrete Batching 8-11
8-11 Particulate Emission Factors for Fiber Glass Manufacturing
Without Controls 8-12
8-12 Emission Factors for Frit Smelters Without Controls 8-13
8-13 Emission Factors for Glass Melting 8-13
8-14 Particulate Emission Factors for Gypsum Processing 8-14
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Table _ Page
8-15 Particulate Emission Factors for Lime Manufacturing Without
Controls - ...........'..... 8-15
8-16 Emission Factors for Mineral Wool .Processing Without Controls , 8-16
8-17 Particulate Emission Factors for Perlite Expansion Furnaces
Without Controls ,...,.,.... 8-17
8-18 Partif»:1ate Emission Factors for Phosphate Rock Processing
Without Controls 8-18
8-19 Particulate Emission Factors for Rock-Handling Processes . . , . 8-19
9-1 Emissitm Factors for Petroleum Refineries • 9-3
10-1 Emission Factors for Sulfate Pulping 10-3
- i
10-2 Particulate Emission Factors for Pulpboard Manufacturing .... 10-4
A-l Percentage Distribution.by Size of Particles from Selected
Sources Without Control Equipment ........ A-Z
A-2 Nationwide Emissions for 1968. A-4
A-3 Distribution by Particle Size of Average Collection Efficiencies
for Various Particulate Control Equipment A-5
A-4 Thermal -Equivalents lor Various Fuels , , A-6
A-5 Weights of Selected Substances. . , A-6
A-6 General Conversion Factors , A-7
x1v 2/72
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ABSTRACT
Emission data obtained from source tests, material balance studies, engineer-
ing estimates, etc. , have been compiled for use by individuals and groups respons-
ible for conducting air pollution emission inventories. Emission factors given in
this document, the result of the expansion and continuation of earlier work, cover
most of the common emission categories; fuel combustion by stationary and
mobile sources; combustion of solid wastes; evaporation of fuels, solvents, and
other volatile substances; various industrial processes; and miscellaneous sources.
When no source-test data are available, these factors can be used to estimate the
quantities of primary pollutants (particulates, CO, SO^, NOx» and hydrocarbons)
being released from a source or source group.
Key words; fuel combustion, stationary sources, mobile sources, industrial
processes, evaporative losses, emissions, emission data, emission
inventories, primary pollutants, emission factors
2/72 xv
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COMPILATION
OF
AIR POLLUTANT EMISSION FACTORS
INTRODUCTION
In the assessment of community air pollution, there is a critical need for
accurate data on the quantity and characteristics of emissions from the numerous
sources that contribute to the problem. The large numbers of these individual
sources and the diversity of source types make conducting field measurements of
emissions on a source-by-source basis at the point of release impractical. The
only feasible method of determining pollutant emissions for a given community is
to make generalized estimates of typical emissions.from each of the source types.
The emission factor is a statistical average of the rate at which a pollutant is
released to the atmosphere as a result of some activity, such as combustion or
industrial production, divided by the level of that activity. For example, assume
that in the production of 260, 000 tons (236, 000 MT*) of ammonia per year, 26, 000
tons (23, 600 MT) of carbon, monoxide is emitted to the atmosphere. The emission
factor for the production of ammonia would therefore be 200 pounds of CO released
per ton (100 kilograms per MT) of ammonia produced. The emission factor thus
relates the quantity of pollutants emitted to some indicator such as production
capacity, quantity of fuel burned, or vehicle miles traveled by autos.
The emission factors presented in this report were estimated by the whole
spectrum of techniques available for determining such factors. These techniques
•include; detailed source testing that involved many measurements related to a
variety of process variables, single measurements not clearly defined as to their
relationship to process operating conditions, process material balances, and
engineering appraisals of a given process.
The limitations and applicability of emission factors must be understood. To
give some idea of the accuracy of the factors presented for a specific process,
each process has been ranked as "A, " "B, " "G, " "D, " or "E. " For a process
with an "A" ranking, the emission factor should be considered excellent, i.e. ,
based on field measurements of a large number of sources. A process ranked "B"
should be considered above average, i, e. , based on a limited number of field
measurements, A ranking of "C" is considered average; "D, " below average; and
*MT = metric ton.
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"E, " poor. These rankings are presented below the table titles throughout the
report.
In general, the emission factors presented are not precise indicators of
emissions for a single process. They are.more valid when applied to-a large num-
ber of processes. With this limitation in mind, emission factors are extremely
useful when intelligently applied in conducting source inventories as part of com-
munity or nationwide air pollution studies.
In addition to the specific tables in each section of this report, the Appendix
presents general data on particle size distribution from various sources, nation-
wide emission estimates for 1968, average collection efficiencies for different
types of participate control equipment, and conversion factors for a number of
different substances.
EMISSION FACTORS 2/72
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1. STATIONARY COMBUSTION SOURCES
Stationary combustion sources include steam-electric generating plants,
industrial establishments, commercial and institutional buildings, and domestic
combustion units. Coalj fuel oil, and natural gas are the major fossil fuels used
by these sources. Other fuels such as liquefied petroleum gas, wood, lignite,
coke, refinery gas, blast furnace gas, and other waste or by-product type fuels
are also used, but the quantities consumed are relatively small. Coal, oil, and
natural gas currently supply about 95 percent of the total heat energy in the United
States. In 1968 over 500 million tons (454 million MT) of coal, 580 million barrels
(92 x 109 liters) of residual fuel oil, 590 million barrels (94 x 10^ liters) of dis-
tillate fuel oil, and 20 trillion cubic feet (566 trillion liters) of natural gas were
consumed in the United States.
The burning of these fuels for both space heating and process heating is one
of the largest sources of sulfur oxides, nitrogen oxides, and particulate emissions.
Controls for particulate emissions are presently being used, but for sulfur oxides
and nitrogen oxides control techniques are not being practiced. The following
sections present detailed emission data for the major fossil fuels—coal, fuel oil,
and natural gas—as well as for liquefied petroleum gas and wood waste. Detailed
information on the size distribution of the particles emitted from the combustion 01
each of these fuels is presented in Table A-l of the Appendix.
BITUMINOUS COAL COMBUSTION
General Information
Coal, the most plentiful fuel in the United States, is burned in a wide variety
of furnaces to produce heat and steam. Coal-fired furnaces range in size from
small hand-fired units, with capacities of 10 to 20 pounds (4.5 to 9 kilograms) of
coal per hour to large pulverized-coal-fired units, which burn 300 to 400 tons (275
to 360 MT) of coal per hour.
Although predominantly carbon, coal contains many compounds in varying
amounts. The exact nature and quantity of these compounds are determined by the
locale of the mine producing the coal and will usually affect the final use of the
coal.
Emissions and Controls
Particulate^ - Particulates emitted from, coal combustion consist primarily of
carbon, silica, alumina, and iron oxide in the fly ash. The quantity of particulate
emissions is dependent upon the ash content of the coal, the type of combustion
unit, and the control equipment used. Table 1-1 gives the range of collection effi-
ciencies for common types of fly-ash control equipment. Particulate emission
factors presented in Table 1-2 for the various types of furnaces are based on the
quantity of coal burned.
2/72 1-1
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Table 1-1, RANGE OF COLLECTION EFFICIENCIES FOR COMMON TYPES
OF EQUIPMENT FOR FLY-ASH CONTROL3
Type of furnace
Cyclone furnace
Pulverized unit
Spreader stoker
Other stokers
Range of collection efficiencies, %
Electrostatic
preci pita tor
65-99b
80-99. 9b
High-
efficiency
cyclone
30-40
65-75
35-90
90-95
Low-
resistance
cyclone
20-30
40-60
70-80
75-35
Settling
chamber expanded
chimney bases
20-30
25-50
Reference 2.
3High values attained with high-efficiency cyclones in series with electrostatic
precipitators.
Sulfur Oxides - Increased attention has been given to the control of sulfur oxide
emissions from the combustion of coal. Lew-sulfur coal has been recommended
in many areas; where this is not possible, other methods in" which the focus is on
the removal of sulfur oxide emissions from the flue gas before it enters the
atmosphere must be considered. No flue-gas desulfurization process is presently
in widespread use, but several methods are presented in Table 1-3 with the expected
efficiencies obtainable from the various types of control. Uncontrolled emissions
of sulfur oxides are shown in Table 1-2 along with the other gaseous emissions.
Other Gases - Gaseous emissions from coal combustion include sulfur oxides,
aldehydes, carbon monoxide, hydrocarbons, and nitrogen oxides. In this section,
attention will be focused on hydrocarbons, carbon monoxide, and nitrogen oxides.
The carbon monoxide and hydrocarbon'content of the gases emitted from
bituminous coal combustion depend mainly on the efficiency of combustion. Success-
ful combustion and a low level of gaseous carbon and organic emissions involve a
high degree of turbulence, high temperatures, and sufficient time for the combus-
tion reaction to take place. Thus, careful control of excess air rates, high com-
bustion temperature, and intimate contact of fuel and air will minimize these
emissions.
Emissions of oxides of nitrogen result not only from, the high-temperature
reaction of atmospheric nitrogen and oxygen in the combustion zone, but also from
partial combustion -of the nitrogenous compounds contained in the fuel. This pol-
lutant is usually emitted at a greater rate from more efficient combustion sources,
which have a higher combustion temperature, and greater furnace release rates.
Factors for gaseous emissions are presented in Table 1-2, The size range in
Btu (kcal) per hour for the various categories is only shown as a guide in applying
these factors and is not meant to clearly distinguish between furnace applications.
1-2
E ISSIO FACTORS
2/72
-------
r\3
~4
INJ
Table 1-2. EMISSION FACTORS FOR BITUMINOUS COAL COMBUSTION WITHOUT CONTROL EQUIPMENT
EMISSION FACTOR RATING: A
Furnace size,
106 Btu/hr
heat input9
Greater than lOfle
(Utility and large
industrial boilers)
Pulverized
General
Wet bottom
Dry bottom
Cyclone
10 to 100 9 (large
co mercial and
general industrial
boilers)
Spreader stoker*1
Less than 101
(commercial and
domestic furnaces)
Spreader stoker
Hand-fired units
Particulatesb
Ib/ton
coal
burned
16A
13ftf
17A
2A
13A*
2A
20
kg/MT
coal
burned
8A
6.5A
8.SA
1A
6.5A
1A
10
Sulfur
oxides^
1 b/ton
, coal
burned
38S
38S
38S
38S
38S
38S
38S
kg/MT
coal
burned
19S
195
19S
19S
19S
19$
19S
Carbon
monoxide
1 b/ton
coal
burned
1
1
1
1
2
10
90
kg/MT
coal
burned
0.5
0.5
0.5
0.5
1
5
45
Hydro-
carbons0"
1 b/ton
coal
burned
0.3
0.3
0.3
0.3
1
3
20
kg/MT
coal
burned
0.15
0.15
0.15
0.15
0.5
1.5
10
Nitrogen
oxides
1 b/ton
coal
burned
18.
30
18
55.
15
6
3
kg/MT
coal
burned
9
15
9
27.5
7.5
3
1.5
Al dehydes
1 b/ton
coal
byrned
0.005
0.005
0.005
kg/MT
coal
burned
0.0025
0.0025
0.0025
0.005 . . ,OC25
0.005
0.005
0.005
0.0025
0.0025
0.0025
00
3°
o
o
1 Btu/hr = 0.252 kcal/hr.
^The letter A on all units other than hand-fired equipment indicates that the weight percentage of ash in the coal
should be multiplied by the value given. Example: If the factor is 16 and the ash content is 10 percent, the partic-
ulate emissions before the control equipment would be 10 times 16, or 160 pounds of particulate per ton of coal (10
times 8, or 80 kg of participates per MT of coal).
CS equals the sulfur content (see footnote b above).
''Expressed as ethane.
References 2 through 7, and 11.
'Without fly-ash reinjection.
iReferences 2, 4, 5, 8, 9, and 11.
Ver all other "stokers, use Sfi "(2.5ft) for partfcuTate emission factor. ~ ;- ;
References 9 through 11.
-------
Table 1-3. SULFUR DIOXIDE REMOVAL
FROM VARIOUS TYPES OF PROCESSES8
Process
Limestone-dolomite
injection, dry process
Limestone-dolomite
injection, wet process
Catalytic oxidation
SOg removal, %
40 to 60
80 to 90
90
Reference 12,
ANTHRACITE COAL COMBUSTION
Because of its low volatile content and the nonclinking characteristics of its
ash, anthracite coal is used in medium-sized industrial and institutional boilers
with stationary or traveling grates. Anthracite coal is not used in spreader
stokers because of its low volatile content and relatively high ignition temperature,
This fuel .may be burned in pulverized-coal-fire'd units, but this practice is. limited
to only a few plants in Eastern Pennsylvania because of ignition difficulties. This
fuel has also been widely used in hand -fired furnaces.
Emissions and Co trols 13
Particulate emissions from anthracite coal combustion are greatly affected
by the rate of firing and by the. ash content of the fuel. Smoke emissions from
anthracite coal are rarely a problem. High grate loadings result in excessive
emissions because of the underfire air required to burn the fuel. Large units
equipped with forced-draft fans may also produce high" rates of particulate emis-
sions. Hand-fired and some small' natural-draft units have fewer particulate emis-
sions because underfire air is not usually supplied by mechanical- means.' '
As is the case with other fuels, sulfur dioxide emissions are directly related
to the sulfur content of the coal. Nitrogen oxides and carbon monoxide emissions
are similar to those found in bituminous -coal-fired units because excess air rates
and combustion temperatures are similar. Because, the volatile matter content of'
anthracite is lower than that of bituminous, hydrocarbon emissions from anthracite
are somewhat lower than those from bituminous coal combustion.
The uncontrolled emissions from anthracite coal combustion are presented in
Table 1-4.
FUEL OIL COMBUSTION
Ge eral Infbrmatio
Fuel oil is one .of the major fossil fuels'uaed in this .country for power produc-
tion, industrial process heating, and space heating, ' It is classified into two major
types, residual and distillate. Distillate fuel oil is primarily a domestic fuel, but"
it is used in some commercial and industrial'applications where a high-quality oil
1-4 E ISSIO FACTORS 2/72
-------
tv>
\
ro
Table 1-4. EMISSIONS FROM ANTHRACITE COAL COMBUSTION WITHOUT CONTROL EQUIPMENT
EMISSION FACTOR RATING: B
Type of furnace
Pulverized (dry bottom),
no fly-ash reinjection
Overfeed stokers,
no fly-ash reinjection
Hand-fired units
Parti cu-
latea'b
Ib/ton
17A
2A
10
kg/MT
8.5A
1A
5
S°2°
1 b/ton
38S
38S
36S
kg/MT
19S
19S
T8S
so3c'd
1 b/ton
0.5S
0.5S
0.8S
kg/MT
0.25S
0.25S
0.4S
HCe'f
1 b/ton
0.03
0.2
2.5
kg/MT
0.015
0.1
1.25
C0g
1 b/ton
1
(2 to 10)J
90
kg/MT
0.5
1 to 5
45
N0xd'h
1 b/ton
18
(6 to 15)k
3
kg/MT
9
3 to 7.5
1.5
C/9
r*>
CU
v>
*-*•
o
o
(D
to
References 8 and 14 through 18.
A is the ash content expressed as weight percent.
£
S is the sulfur content expressed as weight percent.
References 16 and 18 through 20.
g
Based on Reference 8 and bituminous coal combustion.
Expressed as methane.
9Based on bituminous coal combustion.
1
mitted as NO.
Based on data obtained from traveling-grate stokers in the 12 to 180 Btu/hr (3 to 45 kcal/hr) heat input range.
Anthracite is not burned in spreader stokers.
^Use high side of range for smaller-sized units [less than 10 x 10 Btu/hr {2.5 x 10 kcal/hr) heat input].
Use low side of range for smaller-sized units [less than 10 x 10 Btu/hr (2.5 x 10 kcal/hr) heat input].
NOTE: Approximate efficiencies of control devices used for anthracite are cyclone, 75 to 85 percent, and
electrostatic precipitator, 85 percent.
-------
is required. Fuel oils are classified by grades:- grades No, 1 and No. 2 distillate,
Noa. 5 and No, 6''residual, and No, 3 and No, 4 blends. (Grade No, 3 has been
practically discontinued.) Residual fuel is used in power plants, commercial
establishments, and industries. The primary difference between residual oil and
distillate oil is the higher ash and sulfur content of residual oil and the fact that it
is harder to burn properly. Residual fuel oils-have a heating value of approximately
150, 000 Btu/gallon (10,000 kcal/liter), whereas for distillate oils the heating value
is about 140,000 Btu/gallon (9,300 kcal/liter).
Emissions
Emissions from oil combustion are dependent on type and size of equipment,
method of.firing, and maintenance. Table 1-5 presents emission factors for fuel oil
combustion. Note that the industrial and commercial category is split into residual
and distillate because there is a significant difference in partic'ulate emissions
from the same equipment depending on the fuel'oil need. It should also be noted
that power plants emit less particulate matter per quantity of oil consumed, report-
edly because of better design and more precise operation of equipment.
In general, large sources produce more nitrogen oxides than small sources,
p'ririaarily because of the higher flame and boiler, temperatures characteristic of -
large sources. Large sources, however, emit fewer aldehydes than smaller
sources as a result of more complete combustion and higher flame'temperatures.
It may be expected that small sources would emit relatively larger amounts of
hydrocarbons .than large sources because' of the small flame'volume, the large
proportion of relatively cool gases near the furnace walls, and frequently improper
operating practices. These factors were not reflected in the data, however.
NATURAL GAS COMBUSTION
Ge eral I formation
Natural gas is rapidly becoming one of the major-fuels, used throughout the
country. It is used mainly in power plants, industrial -heating, -domestic .and' com-
mercial space heating, and 'gas. turbines.- The primary component of natural gaa
is methane, but smaller quantities of inorganics, particularly nitrogen and.,carbon
dioxide, ar.e also present. Pennsylvania natural gas has been reported to contain
as much as one-third ethane."" .The heating value of natural gas is' approximately •
1,050 Btu per standard cubic foot (9,350 kcal/m3).
Imissio s and Co trols
Even though natural gas Is .considered to be a relatively clean fuel, emissions
sometimes occur from the combustion reaction. When-insufficient air is supplied,.
large amounts 'of carbon monoxide and hydrocarbons may.be produced. Emis- '
sions of sulfur oxides are dependent on the amount of sulfur in the fuel. The sulfur
content of natural gas is usually low, around 2, 000 grains/10^ ft3 (4, 600 g/106 m3).
Nitrogen oxide emissions are a function of the temperature in the combustion
chamber and the rate of cooling of the combustion products. These values vary-
1-6 E ISSIO FACTORS 2/72
-------
B»
•3
O
o
o
n>
Table 1-5. EMISSION FACTORS FOR FUEL OIL COMBUSTION
A
Pollutant
Par ticu late3
Sulfur dioxideb>c
Sulfur trioxideb>c
Carbon monoxide
Hydrocarbons6
Nitrogen oxides (NOg)^
Aldehydes (HCHO)h
Type of unit
Power plant
lb/103 gal
8
157S
2S
0.04
Z
105
1
kg/103
liters
1
19S
0.25S
0.005
0.25
12.6
0.12
Industrial and commercial
Residual
lb/103 gal
23
157S
2S
0.2
3
(40 to 80)9
1
kg/103
1 i ters
2.75
19S
0.25S
0.025
0.35
4.8 to 9.63
0.12
Distillate
lb/103 gal
15
142S
2S
0.2
3
(40 to 80)9
2
kg/103
liters
1.8
17S
0.25S
0.025
0.35
4.8 to 9.69
0.25
Domestic
lb/103 gal
10
142S
2S
5
3
12
2
kg/103
liters
1.2
l^S
0.2SS
0.6
0.35
1.5
0.25
References 21 through 25,
Reference 21.
CS equals percent by weight of sulfur-in the oil.
References 21, and 26 through 29.
References 21, 25, and 28 through 30.
References 21 through 25, ind 28, 29, and 31.
9Use 40 (4.8) for tangentially fired units and 80 (9.6) for horizontally fired units.
References 21, 28, 30, and 31.
-------
considerably with the type and size of unit. Emissions of aldehydes are increased
when there is an insufficient amount of combustion air or incomplete mixing of the
fuel and the combustion air.
Emission factors for natural-gas combustion are presented in Table 1-6, Con-
trol equipment has not been utilized to control emissions from natural-gas combus-
tion equipment,
LIQUEFIED PETROLEUM GAS CONSUMPTION
General Information13
Liquefied petroleum gas, commonly referred to as LPG, consists mainly of
butane, propane, or a mixture of the two, and of trace amounts of propylene and
butylene. This gas, obtained from oil or gas wells or as a by-product of gasoline
refining,- is sold as a liquid in metal cylinders under pressure and, therefore, is
often called bottled gas. LP gases are graded according to maximum vapor pres-
sure, with Grade A being predominantly butane, Grade F being predominantly
propane, and Grades B through E consisting of varying mixtures of butane and
propane. The heating value of LPG ranges from 97,400 Btu/gallon (6,480 kcal/
liter) for Grade A to 90,500 Btu/gallon (6,030 kcal/liter) for Grade F. The largest
market for LPG is presently the domestic-commercial'heating market, followed by
the chemical industry and internal combustion engines,
« 13
Emissions
LPG is considered a "clean" fuel because it does not produce visible emis-
sions. Gaseous pollutants such as carbon monoxide, hydrocarbons, and nitrogen
oxides, however, do occur. The most significant factors affecting these emissions
are the burner design, adjustment, and venting. * Improper design, blocking, and
clogging of the flue vent and lack of combustion air result in improper combustion
that causes the emission of aldehydes, carbon monoxide, hydrocarbons, and other
organics. Nitrogen oxide emissions are a function of a number of variables includ-
ing temperature, excess air, and residence time in the combustion zone. The
amount of SO2 emitted is directly proportional to the amount of -sulfur in the fuel.
Emission factors for LPG combustion are presented in Table 1-7.
WOOD WASTE COMBUSTION IN BOILERS
General Information
Wood is no longer a primary source of heat energy; however, in certain
industries such as lumber, furniture, and plywood, in which it is a readily avail-
able product, wood is a desirable fuel. The wood is used in the form of hogged
chips, shavings, and sawdust.
Firing Practices
In general, furnaces designed for the burning of wood -waste are of three
types: (1) pile, (2) thin-bed, and (3) cyclonic. These furnaces are usually water-
cooled and can be modified to burn supplemental fuel with the wood.
1-8 EMISSION FACTORS 2/72
-------
Table 1-6. EMISSM?N FACTORS FOR NATURAL-GAS COMBUSTION
FACTOR RATING: B
Pol 1 utant
Participates3
Oxides of
sulfurb (SQ2)
Carbon monoxide€
Hydrocarbons^
(CH4)
Oxides of
nitrogen6
(N02)
Aldehydes1
(HCHO)
OrganiesJ
Type of unit
Power plant
lb/lQ6 ft?
15
0.6
0.4
40
390
3
4
kg/ 106 ffl3
240
9.6
6.4
640
6,250
43
64
Industrial
process boilers
lb/106 ft3
18
0.6
0.4
40
(120 to
230)f
3
7
kg/1 06 m3
290
9.6
6.4
i40
1,920 to
3,700f
48
112
Domestic and
commercial
heating units
1b/106 ft3
19
0.6
20
8
{50 to
100)9
10
1
kg/ 106 m3
302
9.6
320
128
800 to
1 ,6009
160
16
Gas turbines
lb/106 «3
-
_
-
_
200
_
-
kg/ 10^ ra3
-
_
.
mm
3,200
»
-
Gas engines
lb/106 «3
-
_
_
_
770 to
7,300h
„
-
kg/1 06 m3
-
_
_
_
12,300 to
117,000
_
.
OJ
££
3"
o
o
tit
o
\
Reference 22.
Reference 36 (based on average sulfur content of natural gas of 2,000 grains/106 ft (4,600 g/106 m3}
""References 37 through 39.
References. 23, and 37 through 39.
References 22, 29, 35, and 44.
Use 120 (1,920) for smaller industrial boilers <500 boiler horsepower and 230 (3,700) for larger industrial boilers
>7,5QQ boiler horsepower.
9Use SO {800} for domestic heating units and 100 (1,600) for commercial units.
hUse 770 (12,300) for oil and gas production; 4,300 (69,000) for gas plants; 4,400 (71,000) for refineries; and
7,300 (117,000) for pipelines.
^References 23, 28, 29, 35, 38," and 40 through 43.
^Reference 44.
-------
Table 1-7. •• EMISSION FOR LPG
EMISSION FACTOR RATING: C
Pollutant
Parti culates
Sulfur oxides
Carbon monoxide
Hydrocarbons
Nitrogen oxidesc
Aldehydes (HCHO)
Other organics
Industrial process furnaces
Butane
1b/103 gal
1.8
0.09S
0.01
4.0
12.1
1.0
0.7
kg/103 liters
0.22
0.005S
0.001
0.48
1.45
0.12
0.08
Propane
lb/103 gal
1.7
0.09S
0.01
3.8
11.2
0.9
0.65
kg/103 liters
-0.20
0.005S
0.001
0.45
1.35
0.11
0.08
Domestic and commercial furnaces
Butane
lb/103 gal
1.9
0.09S
2.0
0.8
6 to 10d
1.0
0.1
kg/103 liters
0.23
0.005S
0.24
0,096
0.72 to 1.2
0.12
0.012
Propane
lb/103 gal
1.8
0.09S
1.9
0,7
6 to 10d
0.9
0.1
kg/103 liters
• 0.22
0.005S
0.23
0.081
0.72 to 1.2
0.11
0.012
m
00
ex»
O
_(
O
yo
CX)
Factors based on an analysis of the similarities between LPG combustion and natural gas and fuel oil combustion,
and data in Reference 22.
S equals sulfur content expressed in grains per 100 ft gas vapor, e.g., if the sulfur content is 0.16 grain per
100 ft3 (0.366 g/100 m3} vapor, the S02 emission factor would be Q.Q9~x 0.16 or 0.014 Ib S02 per 1,000 gallons
(0.005 x 0.366 or 0.0018 kg S02/103 liters) butane burned.
c£xpressed as NOg.
Use 6 -(0.72) for domestic units and-10 (1.2) for commercial units.
IS»
[\>
-------
In pile burning, the wood is fed through the furnace roof and burned in a cone-
shaped pile on the grate. Thin-bed burning is accomplished on a moving grate :
similar to that of a spreader stoker. In a cyclone furnace, wood (especially bark)
is usually burned "with coal,
Emissions
Excessive smoking results from improper grate-maintenance of wood-bur ijiing
furnaces, especially where coal is burned simultaneously with the wood. Another
major factor affecting emissions is the water content of the wood refuse. This jis
not only a function of the absorptive property of the wood, but also a function of,the
process that produces the waste. Wet bark generally produces more emissions1
than kiln-dried lumber.. Of minor importance, except as it reflects on the factor
noted above, is the composition of the material being burned. For example, bark
contains less carbon and nitrogen, but more sulfur than wood. This difference
coupled with a high moisture content is thought to account for the more severe dust
and smoke problems associated with burning bark. Emission factors for the com-
bustion of wood and bark in boilers are shown in Table 1.-8.
Table 1-8.
COMBUSTION IN BOILERS WITH NO REINJECTION
EMISSION FACTOR RATING; C
EMISSION FACTORS FOR WOOD AND BARK
a,b
Pollutant
Participates0
Sulfur oxides (S02)d
Carbon monoxide
Hydrocarbons6
Nitrogen oxides (N0£)
Carbonyl sf
Emissions
1 b/ton
25 to 30
0 to 3
2
2
10
0.59
kg/MT
12.5 to 15.0
0.0 to 1.5
1
1
5
0.259
References 46 through 49.
Approximately 50 percent moisture content.
cThis number is an atmospheric emission factor with-
out fly ash reinjection. For boilers "with reinjec-
tion, the particulate loadings reaching the control
equipment are 30 to 35 Ib/ton (15 to 17.5 kg/MT)
fuel with 50 percent reinjection and 40 to 45 1b/ton
(20 to 22.5 kg/MT) fuel with 100 percent reinjection,
Use 0 for most wood and higher values for bark.
Expressed as methane.
Emitted as formaldehyde.
%ased on trench incinerator emission.
2/72
Stationary Combustion Sources
l-ll
-------
REFERENCES FOR CHAPTER 1
1. . Nationwide Inventory of Air Pollutant Emissions, 1968. U.S. DHEW, PHS,
EHS, National Air Pollution Control Administration. Raleigh, N,-C. Publica-
tion No. AP-71, August 1970. • • '
2. Smith, W. S. Atmospheric Emissions from Coal Combustion. U.S. DHEW, •
PHS; National Center for Air Pollution Control. Cincinnati, Ohio. PHS.
Publication No, 999-AP-24. April 1966. p. 72, •
3. Perry, H, and J. H, Field, Air Pollution and the;Coal Industry. Transac-
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4. Heller, A. W. and D, F. Walters. Impact of Changing Patterns of Energy
Use on Community Air Quality. J. Air Pollution Control Assoc. 1_5_;42'6,
September 1965. ' .
5. Smith, W. S. Atmospheric Emissions from Coal Combustion, U.S. DHEW,
PHS, National Center 'for Air Pollution Control. Cincinnati, Ohio. PHS
Publication No. 999-AP-24. April 1966. p. 1.
6. Cuffe, S. T. and R. W. Gerstle. Emissions from Coal-Fired Power Plants:
A Comprehensive Summary. U.S. DHEW, PHS, National'Air Pollution Con-
trol Administration, Raleigh, N. .C. PHS Publication No. 999-AP-35. 1967.
p. 15. . .
7, Austin, H. C. Atmospheric Pollution Problems of the Public Utility" Industry.
J. Air Pollution Control Assoc. l_0(4):292-294, August I960.
8. Hovey,- H. H. , A. Risman, and J. F. Cunnan. .The Development of Air Con-
taminant Emission Tables for Nonprocess Emissions. J. Air Pollution Con-
trol Assoc. 16;362-366, July 1966.
9. Anderson, D. M. , J. Lieben, and V. H. Sussman. Pure Air for Pennsylvania.
Pennsylvania Department of Health, Harrisburg, Pa, November 1961. p.
91-95.
10, Communication with National Coal Association. Washington, D. C, Septem-
ber 1969. - ' '
11, Hangebrauck, R. P., D, S. Von Lehmden, and J. E. Meeker. Emissions of
Polymiclear Hydrocarbons and Other Pollutants from Heat Generation and
Incineration Processes. J', Air Pollution Control Assoc. _l_4;2:67-2?8, July
1964. . .
12. Control Techniques for Sulfur Oxide Air Pollutants. U, S. DHEW, PHS, EHS,
National Air Pollution Control Administration. Washington, D.. C. " Publica-
tion No, AP-52, January 1969. p. xviii and xxii.
13, Air Pollutant Emission Factors. Final Report. Resources Research, Incor-
porated, Reston, Virginia, Prepared for National Air Pollution Control •
Administration'under contract No. CPA-22-69-119. April 1970. - •
1-12 EMISSION FACTORS 2/72
-------
14. Unpublished stack test data on emissions from anthracite coal combustion,
Pennsylvania Air Pollution Commission. Harrisburg, Pa. 1969.
15, Unpublished stack test data on emissions from anthracite coal combustion.:
New Jersey Air Pollution Control Program. Trenton, N. J. 1969.
16. Anderson, D. M. , J. Lieben, and V. H. Sussman, Pure Air for Pennsylvania.
Pennsylvania Department of Health. Harrisburg, Pa. November 1961. p.,15,
17. Blackie, A. Atmospheric Pollution from Domestic Appliances. The Report
of the Joint Conference of the Institute of Fuel and the National Smoke Abate-
ment Society. London. February 23, 1945,
18, Smith, W. S. Atmospheric Emissions from Coal Combustion, U.S. DHEW,
PHS, National Center for Air Pollution Control. Cincinnati, Ohio. PHS
Publication No. 999-AP-24. April 1966. p. 76.
19. Crumley, P. H. and A. W. Fletcher. The Formation of Sulphur Trioxide in
Flue Gases. J, Inst. of Fuel Combustion. _3£:608-612, August 1957.
20. Chicago Association of Commerce, Committee of Investigation. Smoke Abate-
ment and Electrification of Railway Terminals in Chicago. Chicago, Rand
McNally Co. 1915. p. 1143.
21. Smith, W. S. Atmospheric Emissions from Fuel Oil Combustion: An Inven-
tory Guide. U. S. DHEW, PHS, National Center for Air Pollution Control.
Cincinnati, Ohio. PHS Publication No. 999-AP-2. 1962.
22. Weisburd, M. I. and S. S. Griswold (eds, ). Air Pollution Control Field ;
Operations Manual; A Guide for Inspection and Enforcement. U, S. DHEW,
PHS, Division of Air Pollution. Washington, D. C. PHS Publication No. i937.
1962.
23. Magill, P. L. and R. W. Benoliel. Air Pollution in Los Angeles County: •
Contribution of Industrial Products. Ind. Eng. Chem. 44:1347-1352, June
1952.
24, The Smog Problem in Los Angeles County. Menlo Park, Calif. , Stanford
Research Institute. Western Oil and Gas Association. 1954. ;
25, Taylor, F, R. et al. Emissions from Fuel Oil Combustion. Final Report.
Prepared for American Petroleum Institute, Scott Research Lab, Perkasie,
Pa. March 1963.
26. Unpublished data from San Francisco Bay Area Air Pollution Control District
on emissions from fuel oil combustion. 1968.
27. Unpublished data from Los Angeles County Air Pollution Control District on
fuel oil combustion, April 8, 1969.
28. Wasser, J. H, , G. B, Martin, and R. P. Hangebrauck, Effects of Combus-
tion Gas Residence Time on Air Pollutant Emissions from Oil-Fired Test
Furnace. U.S. DHEW, PHS, CPEHS, National Air Pollution Control Adrn,in-
tstration, Cincinnati, Ohio. September 1968.
2/72 Stationary Combustion Sources 1-13
-------
29. - Howekamp, D. P.. and M. K. "Hooper. Effects of.Combustion-Improving
Devices on Air Pollutant Emissions from Residential Oil-Fired Furnaces,
U.S. DHEW, -PHS, "National Air Pollution Control Administration. Cincinnati,
Ohio, June 1970.
30, MacChee, R. D,, J. R, Taylor, and R. L. Chaney, Some Data on Particu-
lates from Fuel'Oil'Burning.- Los Angeles County Air Pollution Control Dis-
trict, Presented at APCA Semiannual Technical Conference; San Francisco,
California. November 1957. - ' ' •..':..
31. Chass, R. L, and.R. E. George. • Contaminant Emissions from Combustion
of Fuels, J. Air Pollution Control Assoc,, jJO_:34-43, February I960. . '
32.. Hangebra-uck, R. P., D. S. Von Lehmden, - and J. E. Meeker. Emissions of
Polynuclear Hydrocarbons and Other Pollutants from Heat Generation and"
Incineration Processes. J. Air Pollution Control Assoc. 14:271, July 1964.
33. Chass, R. L., R. G. Lunche, N. R. Schaffer, and P. S. Tow. Total Air
Pollution Emissions' in Los Angeles County. J,' Air Pollution Control Assoc,
Kh351-365, October I960, : •
34. Shreve, R, N. Chemical Process Industries. 3rd ed, • New York, McGraw-
Hill Book Co., 1967. - .
35. Hall, E. L. What Is the Role of the Gas Industry in Air Pollution'? Proceed-
ings of Second National Air Pollution Symposium. Pasadena^ Calif. 1952,
• p. 54-58. - ' . ' '
36. Hovey, H. H., A. Ris'man, and J. F. Cuiman. The Development of Air Con-
taminant Emission Tables for Nonproeess Emis'sions. New York State-Depart-
ment of Health. Albany, N, Y. 1965. • • '
37. Private Communication with the American Gas Association Laboratories, •
Cleveland, Ohio. May 1970.
38. Wohlers, H. C. and G. B. Bell. Literature Review of Metropolitan Air. Pol- •
lutant Concentrations: Preparation,. Sampling, and Assay of Synthetic Atmos-
pheres. Menlo Parkj Calif., Stanford Research Institute. 1956.
39. Unpublished data on domestic gas-fired units.. 'U.S. DHEW, PHS, EHS, •
National Air Pollution Control Administration, Cincinnati, Ohio, 1970.
40, Hall, E. 'L. Products of Combustion of Gaseous Fuels. Proceedings -of Second
National Air Pollution Symposium, Pasadena, Calif, 1952. p. 84. - :
41; Faith, W. L. Combustion and Smog. Report No. 2, Southern California Air -
Pollution Foundation. Los Angeles, Calif. September 1954.
42. Vandaveer, F, E. and C. G. Segeler. Ind. Eng.. Chem. 37^816-820, 1945.
See also-correction" in Ind, Eng.' Chem. 44:1833, ' 1952. '.
43, --Emissions in the Atmosphere from Petroleum Refineries. Los .Angeles County
Air Pollution Control District. Report No. 7. 1958, p. 23.
1-14 E ISSIO FACTORS 2/72
-------
44. Unpublished data from San Francisco Bay Area Air Pollution Control District
on. emissions from natural gas combustion. 1968,
45, Clifford, E. A, A Practical Guide to Liquefied Petroleum Gas Utilization,!
Moore Pub, Co., New York. 1962.
46. Hough, G, W. and L, J, Gross, Air Emission Control in a Modern Pulp and
Paper Mill. Amer, Paper Industry. 5_1_:36, February 1969.
47. Fryling, G. R. (ed.). Combustion Engineering. New York. 196?. p. 27J-3,
48. Private communication on wood combustion with W. G, Tucker. Division of
Process Control Engineering, U.S. DHEW, PHS, EHS» National Air Pollution
Control Administration, Cincinnati, Ohio, November 19, 1969.
49. Burckle, J. O, , J, A. Dorsey, and B. T. Riley. The Effects of Operating
Variables and Refuse Types on Emissions from a Pilot-Scale Trenth Incinera-
tor. Proceedings of the 1968 Incinerator Conference, ASME. New York, [
May 1968. p. 34-41.
2/72 Stationary Combustion Sources 1-15
-------
-------
2. SOLID WASTE DISPOSAL
As defined in the Solid Waste Disposal Act of 1965, the term "solid waste"
means garbage, refuse, and other discarded solid materials, including solid-
waste materials resulting from industrial, commercial, and agricultural opera-
tions, and from community activities. It includes both combustibles and noncom-
bustibles,
An average of 5, 5 pounds (2. 5 kilograms) of refuse and garbage is collected
per capita per day in the United States. ^ This does not include some of the uncol-
lected waste such as industrial waste, wastes burned in commercial and apartment
house incinerators, and wastes disposed of by backyard burning, which contribute
at least 4. 5 pounds (2 kilograms) per capita per day. Together, this gives a con-
servative per capita generation rate of 10 pounds (4.5 kilograms) per day.
Approximately 50 percent of all the generated waste in the United States is burned
by a wide variety of combustion methods including both enclosed and open burning.
Atmospheric emissions, both gaseous and particulate, result from refuse-disposal
operations that utilize combustion to reduce the quantity of refuse. Emissions
from; these combustion processes cover a wide range because of their dependence
on the refuse burned, the method of combustion or incineration, and many other
factors. Because of the large number of variables involved, it was impossible in
most cases to establish usable ranges in emission factors and to delineate those
conditions when the upper or lower limit should be used. For this reason, in most
cases, only a single factor has been presented.
REFUSE INCINERATION
Process Description3-6
The most common types of incinerators consist of a refractory-lined chamber
with a grate upon which refuse is burned. Combustion products are formed by con-
tact between underfire air and waste on the grates in the primary chamber.
Additional air (overfire air) is admitted above the burning waste to promote gas-
phase combustion. In the multiple-chamber-type incinerator, gases from the pri-
mary chamber flow to a small mixing chamber where more air is admitted, then to
a larger, secondary chamber where more complete oxidation occurs. As much as
150 percent excess air may be supplied in order to promote oxidation of combusti-
bles. Auxiliary burners are sometimes installed in the mixing chamber to increase
the combustion temperature. Many small-size incinerators are single-chamber
units, in which gages are vented from the primary combustion chamber directly
into the exhaust stack.
Definitio s of I ci erator Categories
No exact definitions of incinerator size categories exist, but for this report
the following general categories and descriptions have been selected:
1, Municipal incinerators - These multiple-chamber units have capacities
greater than 50 tons (45.3 MT) per day and are usually equipped with
2/72 2-1
-------
automatic charging mechanisms and temperature controls. Municipal
incinerators are also usually equipped with some type of particulate con-
trol device, such as a spray chamber,
2. Industrial/commercial incinerator a - These units cover a wide range,
generally between 50 and 4, 000 pounds per hour (22. 7 and 1, 800 kilo-
grams). Of either single- or multiple-chamber design, they are fre-
quently manually charged and intermittently operated. Better designed
emission control systems include gas-fired afterburners or scrubbing,
or both.
3, Domestic incinerators - This category include incinerators marketed for
residential use. Fairly simple in design, they may have single or
multiple chambers and usually are equipped with an auxiliary burner to
aid combustion.
4. Flue-fed incinerators -These units, commonly found in large apartment
houses, are characterized by the charging method of dropping refuse
down the incinerator flue and into the combustion chamber. Modified
flue-fed incinerators utilize afterburners and draft controls to improve
combustion efficiency and reduce emissions.
5, Pathological incinerators - These are incinerators used to dispose of
animal remains and other organic material of high moisture content.
Generally, these units are in a sisse range of 50 to 100 pounds (22, 7 to
45. 4 kilograms) per hour. They are equipped with combustion controls
and afterburners to ensure good combustion and minimum emissions.
6. Controlled air incinerators - These units operate on the controlled com-
bustion principle in which a small percentage of the air theoretically
required to burn the waste is supplied to the main chamber. These units
are usually equipped with, automatic charging mechanisms and are charac-
terized by the high effluent temperatures reached at the exit of the
incinerators.
Emissions and Controls3
Operating conditions, refuse composition, and basic incinerator design
determine the composition of the effluent and thus the nature of emissions. The
manner in which air is supplied to the combustion chamber or chambers has the
greatest effect on the quantity of particulate emissions. Air may be introduced
from beneath the chamber, from the side, or from the top of the combustion
chamber. As underfire air is increased, fly-ash emissions increase. The way
in which refuse is charged also has an effect on the particulate emissions.
Improper charging disrupts the combustion bed and precipitates release of large
quantities of particulates. Emissions of oxides of sulfur are dependent on the sul-
fur content of the refuse. Nitrogen oxide emissions depend on the temperature of
the combustion zones, their residence time in-the combustion zone before quench-
ing, and the excess air rate. Carbon monoxide and hydrocarbon emissions also
depend on the quantity of air supplied to the combustion chamber and the efficiency
of combustion.
2-2 E ISSIO FACTORS 2/72
-------
Table 2-1 lists the relative collection efficiencies of particulate control equip-
mcnt used for municipal incinerators. This control equipment has little effect
on gaseous emissions. Table 2-2 summarizes the uncontrolled emission factors
for the various types of incinerators previously discussed.
Table 2-1. COLLECTION EFFICIENCIES FOR VARIOUS TYPES
OF MUNICIPAL INCINERATION PARTICULATE CONTROL SYSTEMS3
Type of system
Settling chamber
Settling chamber and water spray
Wetted baffles
Mechanical collector
Scrubber
Electrostatic precipitator
Fabric filter
Efficiency, %
0 to 30
30 to 60
60
30 to 80
80 to 95
90 to 96
97 to 99
References 5, 7 through 13.
AUTOMOBILE BODY INCINERATION
Process Description3
Auto incinerators consist of a primary combustion chamber in which one Or
several partially stripped cars are burned. (Tires are removed.) Approximately
30 to 40 minutes is required to burn two bodies simultaneously. Up to 50 car|S
per day can be burned in this batch-type operation, depending on the capacity of
the incinerator. Continuous operations in which cars are placed on a conveyor
belt and passed through a tunnel-type incinerator have capacities of more than pQ
cars per 8-hour day.
Emissions and Controls3
Both the degree of combustion as determined by the incinerator design and
the amount of combustible material left on the car greatly affect emissions.
Temperatures on the order of 1ZOO° F (650e C) are reached during auto body
incineration. " This relatively low combustion temperature is a result of the
large incinerator volume needed to contain the bodies as compared to the small
quantity of combustible material. The use of overfire air jets in the primary c}om-
bustion chamber increases combustion efficiency by providing air and increasejd
turbulence.
In an attempt to reduce the various air pollutants produced by this burning,
some auto incinerators are equipped with emission control devices. Afterburners
and low-voltage electrostatic precipitators have been used to reduce particulate
emissions; the former also reduces some of the gaseous emissions. ^3, 24 -yy^qn
afterburners are used to control emissions, the temperature in the secondary com-
bustion chamber should be at least 1500° F (815° C). Lower temperatures result
in higher emissions. Emission factors for auto body incinerators are presented
in Table 2-3.
2/72 Solid Waste Disposal 2-3
-------
Table 2-2. EMISSION FACTORS FOR REFUSE INCINERATORS WITHOUT CGNTROLSa
EMISSION FACTOR RATIMG: A
c/»
O
o
—i
O
Incinerator type
Municipal6
Multiple chamber,
uncontrolled
With settling chamber
and water spray system^
Industrial/eommercla'!
Multiple chamb'sri
Single chamber''
Controlled air-*
Flue-fedk
Flue-fid (modified}1 »m
Domestic single chamber
Without primary burner"
With primary burner0
PathologicalP
Participates
Ib/ton
30 (8 to 70)
14 (3 to 35)
7 (4 to 8)
15 {4 to 31)
1.4(0.7 to 2}
30 (7 to 70)
6 (1 to 10)
35
7
8 (2 to 10)
kg/m
15
7
.3.5 -
7.S
0.7
15
3
17.5
3.5
4
Sulfur
ox i desk
Ib/ton
1,5
1.5
l,ih
1.5"
1.5
0.5
0.5
0.5
0.5
Neg
kg/MT
0.75
0.75
0.75
0.75
0.75
0.25
0.25
0.25
0.25
Nig
Carbon monoxide
Ib/ton
35(0 to 233)
35(0 to 233)
10(1 to 25)
20(4 to 200)
Neg
20
10
300
Neg
Neg
kg/m
17.5
17.5
5
10
Neg
10
5
150
leg
(eg
Hydrocarbonsc
Ib/ton
• ' 1.5
1.5
3(0.3 to 20)
15(0.5 to 50)
Neg
15(2 to 40)
3(0.3 to 20)
100
2
- Nef
kg/MT
0.75
0.75
1.5
7.5
Neg
7.5
1,5
50
1
Neg
Nitrogen
oxides'!
Ib/ton
2
2
3
2
10
3-
10
1
2
3
kg/MT
i
i
1.5
1
5
1,5
5
0.5
1
1,5
ro
"si
Average factors given based on EPA procedures for incinerator stack testing. Use high side of particulate, HC, and CO
emission ranges when operation is intermittent and combustion conditions are poor.
Expressed as SOg.
Expressed as methane. ' .
Expressed as N02-
References 7, and 14 through 19.
Most municipal incinerators are equipped with at least this much control; see Table 2-1 for appropriate efficiencies for
other controls,
%eferinces 6,7,11,19, and 20.
Based on municipal incinerator data.
^References 5,7,16, and 20.
JReference 15. •''''. '• • *-
^References I, 16, 17, and 19 through 21.
With afterburners and draft controls. '
"'References 5, 17, and 20.
"References, 7 and 16. ' • .'••'.'
"Reference 7. - ; : ' ' • ' '
^References 5 and 15.
-------
Table 2-3. EMISSION FACTORS FOR AUTO BODY INCINERATION3
EMISSION FACTOR RATING: B
Pollutants
Particulatas13
Carbon monoxide0
Hydrocarbons0 (Dty)
Nitrogen oxides^ (NOg)
Aldehydesd (HCOH)
Organic aeids^ (Acetic)
Uncontrolled
Ib/ear
2
2.5
0.5
0.1
0.2
0.3
kg/car
0.9
1.1
0.23
0.05
0.09
0.14
With afterburner
Ib/car
1.5
Neg
Neg
0.02
0.06
0.4
kg/car
0,68
Neg
Neg
0.01
0.03
0.18
aBased on 250 Ib (112 kg) of combustible material on stripped
car body,
References 22 and 24.
cBased on data for open burning and References 22 and 25,
Reference 24.
CONICAL BURNERS
Process Description3
Conical burners are generally a truncated metal cone with a screened top
vent. The charge is placed on a raised grate by either conveyor or bulldozer, .
Use of a conveyor results in more efficient burning than placing the charge by '•
bulldozer. No supplemental fuel is used, but combustion air is often supplemented
by underfire air blown into the chamber below the grate and by overfire air intjro-
duced through peripheral openings in the shell,
Emissions and Controls
The quantities and types of pollutants released from conical burners are :
dependent on the composition and moisture content of the charged material, con-
trol of combustion air, type of charging system used, and the condition in whiqh
the incinerator is maintained. The most critical of these factors seems to be the
lack of maintenance on the incinerators. It is not uncommon for conical "burners
to have missing doors and numerous holes in the shell-—resulting in excessive
combustion air, low temperatures, and therefore high emission rates.
26
Particulate control systems have been adapted to conical burners with so|me
success. These control systems include water curtains (wet caps) and water
scrubbers. Emission factors for conical burners are shown in Table 2-4.
OPEN BURNING
General Information3
Open burning can be done in open drums or baskets and in large-scale open
dumps or pits. Materials commonly disposed of in this manner are municipal
waste, auto body components, landscape refuse, agricultural field refuse, wood
refuse, and bulky industrial refuse.
2/72
Solid Waste Disposal
2-5
-------
Table 2-4. EMISSION FACTORS FOR WASTE INCINERATION IN CONICAL BURNERS
WITHOUT CONTROLS3
EMISSION FACTOR RATING: B '
Type of
waste
Municipal
refuse*5
Wood6
Particulates
Ib/ton
20(10 to 60)c«d
if
79
20h
kg/MT
10
0.5
3.5
10
Sulfur
oxides
Ib/ton
2
0.1
kg/MT
1
0.05
Carbon
monoxide
Ib/ton
60
130
kg/MT
30
65
Hydrocarbons •
Ib/ton
20
11
kg/MT
10
5.5
Nitrogen
oxides
Ib/ton
5
1
kg/MT
-2.5.
0.5
Moisture content as fired is approximately 50 percent for wood waste.
Except for part-iculates, factors are based on comparison with other waste disposal.
practices.
Use high side of range for intermittent operations charged with a bulldozer. -
Based on Reference 27.
References 28 through 33. - . •
Satisfactory operation; properly maintained burner with adjustable underfire air
supply and adjustable, tangential overfire air inlets, approximately.500 -percent .
excess air and 700° F (370° C) exit gas temperature.
^Unsatisfactory operation: properly maintained burner with radial overfire air
supply near bottom of shell, approximately 1,20.0'percent excess air and 400° F
(204° C) exit gas temperature. •.'."'.-.
Very unsatisfactory operation: improperly maintained burner with radial overfire
air supply near bottom of shell and many gaping holes in shell, approximately
1,500 percent excess air and 400° F (204° C) exit gas temperature.
Emissions
" Ground-level open burning is affected by many variables including wind,
ambient temperature, composition and moisture content of the debris burned, size
and shape of the debris burned, and compactness of the pile. In general, the . '
relatively low temperatures associated with open burning increase the emissions. :.
of particulates, carbon monoxide, and hydrocarbons and suppress the amis scions
of nitrogen oxides. Sulfur oxide emissions are also a direct function -of the sulfur
content of the refuse. Emission factors are presented in Table 2-5 for the open'
burning of.three broad categories of waste: .(1) municipal refuse, (2) automobile
components, and (3) horticultural refuse. -
2-6
E ISSIO FACTORS
2/72
-------
•xj
ro
Table 2-5. EMISSION FACTORS FOR OPEK BURNING
EMISSION FACTOR RATING; B
Type of waste
Municipal refusea
Automobile components^ »c
Horticultural refuse^
Agricultural field burning
Landscape refuse and pruning
Wood
Particulates
Ib/ton
16
TOO
17
17
17
kg/MT
8
50
8.5
8.5
8.5
Sulfur oxides
Ib/ton
1
Neg
Neg
Neg
Neg
kg/MT
0.5
Neg
Neg
Neg
Neg
Carbon
monoxide
1 b/ton
85
125
100
60
50
kg/MT
42.5
62.5
50
30
25
Hydrocarbons
(CH4)
Ib/ton
30
30
20
20
4
kg/MT
15
15
10
10
2
Nitrogen
oxides
Ib/ton
6
4
2
2
2
kg/MT
3
2
1
1
1
o_
rx
a
References 25 and 34 through 37.
DUpholstery, belts, hoses, and tires burned in common.
"Reference 25.
References 25, 36, and 38 through 40.
ISJ
I
-------
REFERENCES FOR CHAPTER 2
1. Black, Ralph J., H. Lanier Hickman, Jr., Albert!. Klee, Anton J. Muchick,
and Richard D. Vaughan. The National Solid Waste Survey: An Interim
Report, Public Health Service, Environmental Control Administration,.
Rockville, Maryland. 1968.
2. Nationwide Inventory of Air Pollutant Emissions, 1968. U.S. DHEW, PHS,
EHS, National Air Pollution Control Administration. Raleigh, North'Carolina.
Publication No. AP-73. August 1970.
3, Air Pollutant Emission Factors, Final Report, Resources Research Incor -
porated, Reston, Virginia. Prepared for National Air Pollution Control
Administration under contract No. CPA-E2-69-119. April 1970.
4. Control Technique's'for Carbon Monoxide Emissions from Stationary Sources.
U.S..DHEW, PHS, EHS, National Air Pollution Control Administration,
Washington, B.C. Publication No AP-65. March 1970.
5, Danielson, J. A, (ed. ). Air Pollution Engineering Manual. U.S. DHEW,
PHS Publication No. 999-AP-40. National Center for Air Pollution Control.
Cincinnati, Ohio. . 1967 p. 413-503.
6. De Marco, J. et al. Incinerator Guidelines 1969. U.S. DHEW, PHS.
Cincinnati, Ohio. SW-13TS. 1969- p. 176. '
7. Ranter, C. V., R. G. Lunche, and A, P. Fururich. Techniques for Testing
for Air Contaminants from Combustion Sources. Air Pollution Control
Assoc. 6(4):191-199. February 1957..
8. Jens. W. and F.R. R.ehm. Municipal Incineration and Air Pollution Control,
1966 National Incinerator Conference, ASME. New York, May 1966.
9. Rehm, F.R.. Incinerator Testing and Test Results. J. Air Pollution Con-
trol Assoc. 6_:199~204. February 1957.
10. Stenburg, R.L. et al. Field Evaluation of Combustion Air Effects on Atmos-
pheric Emissions from Municipal Incinerations. J. Air Pollution Control
Asso.c. _12_;83-89. February 1962.
11. Smauder, E.E. Problems of Municipal Incineration-. Presented at First
Meeting of Air Pollution Control Association, West Coast Section, Los Angeles,
California. March 1957.
12, Gerstle, R. W, Unpublished data; revision of emission factors based on
recent stack tests, U.S. DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio. 1967.
13. A Field Study of Performance of Three Municipal Incinerators, University
of California, Berkeley, Technical Bulletin. _6:41, November 1957.
14. Ferna.ad«.'3, J. H. Incinerator Air Pollution Control. Proceedings of 1968
National Incinerator Conference, ASME. New York. May 1968. p. 111.
2-8 E 1SSIO FACTORS 2/72
-------
15. Unpublished data on incinerator testing. U.S. DHEW, PHS, EHS, National!
Air Pollution Control Administration. Durham, N. C. 1970.
16, Stear, J. L. Municipal Incineration; A Review of Literature, Environ-
mental Protection Agency, Office of Air Programs. OAP Publication No.
AP-79. Research Triangle Park, N, C. June 1971.
17, Kaiser, E.R, et al. Modifications to Reduce Emissions from a Flue-fed
Incinerator. New York University. College of .Engineering. Report No.
552.2. June 1959, p. 40 and 49.
18. Unpublished data on incinerator emissions, U.S. DHEW, PHS, Bureau of
Solid Waste Management. Cincinnati, Ohio. 1969.
19. Kaiser, E.R. Refuse Reduction Processes in Proceedings of Surgeon
General's Conference on Solid Waste Management,; Public Health Service.
Washington, B.C. PHS Report No, 1729, July 10-20, 1967.
20. Unpublished source test data on incinerators. Resources Research, Incor-
porated. Reston, Virginia. 1966-1969-
21. Communication between Resources Research, Incorporated, Reston, Virginia,
and Maryland State Department of Health, Division of Air Quality Control.
1969,
22. Kaiser, E.R. and J. Tolcias. Smokeless Burning of Automobile Bodies. J.
Air Pollution Control Assoc. J_2_:64-73. February 1962,
23. Alpiser, F. M. Air Pollution from Disposal of Junked Autos, Air Engineer-
ing, H):18-22, "November 1968.
24. Private Communication with D.F, Walters, U.S. DHEW, PHS, Division of
Air Pollution. Cincinnati, Ohio. July 19, 1963.
25. Gerstle, R. W, and D.A. Kemnitz. Atmospheric Emissions from Open
Burning. J. Air Pollution Control Assoc. j/7_;324-327. May 1967,
26. Kreichelt, T. E. Air Pollution Aspects of Teepee Burners. U.S. DHEW, PHS,
Division of Air Pollution. Cincinnati, Ohio. PHS Publication No. 999-
AP-28. September 1966.
27, Magill, P. L. andR.W. Benoliel. Air Pollution in Los Angeles County:
Contribution of Industrial Products. Ind. Eng, Chem. 44_: 1347-1352, June
1952.
28. Private Communication with Public Health Service, Bureau of Solid Waste
Management. Cincinnati, Ohio. October 31, 1969.
29. Anderson, D. M, , J. Lieben, and V.H.Sussman. Pure Air for Pennsylvania.
Pennsylvania State Department of Health, Harrisburg, Pa. November 1961.
p, 98.
2/72 Solid Waste Disposal 2-9
-------
30. Boubel, R. W. et al. Wood Waste Disposal and Utilization. Engineering
Experiment Station, Oregon State University, Corvallis, Oregon. Bulletin
No. 39, June 1958. p. 57.
31. Netzley, A.B. and J,E. Williamson. Multiple Chamber Incinerators for
Burning Wood Waste. In: Air Pollution Engineering Manual, Danielson, J.A.
(ed.) U.S. DHEW, PHS, National Center for Air Pollution Control, Cincinnati,
Ohio. PHS Publication No. 999-AP-40. 1967. P. 436-445.
32. Droege, H. and G. Lee. The Use of Gas Sampling and Analysis for the
Evaluation of Teepee Burners, Bureau of Air Sanitation, California Depart-
ment of Public Health, Presented at the Seventh Conference on Methods in Air
Pollution Studies, Los Angeles, California. January 25-26, 1965.
33. Boubel, R.W. Particulate Emissions from Sawmill Waste Burners. Engi-
neering Experiment Station, Oregon State University, Corvallis, Oregon.
Bulletin No. 42. August 1968. p. 7-8.
34. Burkle, J.O. , J. A. Dorsey, and B. T. Ril-oy.- The Effects of Operating
Variables and Refuse Types on Emissions from a Pilot-Scale Trench Incin-
erator. Proceedings of the 1968 Incinerator Conference, ASME. New York
May 1968. p. 34-41.
35. Weisburd, M.I. andS.S. Griswold (eds. ). Air Pollution Control Field Opera-
tions Manual; A Guide for Inspection and Control. U. S. Government Print-
ing Office. Washington, B.C. Publication No 937. 1962.
36. Unpublished data: Estimated major air contaminant emissions. State of
New York, Department of Health. Albany, New York. April 1, 1968.
Table A-9.
37. Darley, E.F. et al. Contribution of Burning of Agricultural Wastes to
Photochemical Air Pollution. J. Air Pollution Control Assoc. 16:685-690.
December 1966.
38. Feldstein, M. et al. The Contribution of the Open Burning of Land Clear-
ing Debris to Air Pollution. J. Air Pollution Control Assoc. _13 ; 542-545.
November 1963.
39, Boubel, R.W., E.F. Darley, andE.A. Schuck. Emissions from Burning
Grass Stubble and Straw. J. Air Pollution Control Assoc. 19:497-500,
July 1969.
40. Waste Problems of Agriculture and Forestry. Environmental Science and
Technology, 2^:498, July 1968.
2-10 E ISSIO FACTORS 2/72
-------
3. MOBILE COMBUSTION SOURCES
Transportation in general is a major source of carbon monoxide, hydrocar-
bons, and nitrogen oxides. In 1968 estimated emissions from all transportation
sources in the United States were 64 million tons (58 million MT) of carbon monox-
ide, 17 million tons (15, 4 million MT) of hydrocarbons, and 8 million tons (7, 25
million MT) of nitrogen oxides, * The primary mobile source of these emissions
is the gasoline-powered motor vehicle. Other (significant sources include aircraft,
diesel-powered trucks and buses, locomotives, and river vessels. Emission
factors for these sources are presented in this section. The effects of controls
have been shown whenever possible.
GASOLINE-POWERED MOTOR VEHICLES
General
The gasoline-powered motor vehicle category consists of three major types
of vehicles: passenger cars, light-duty trucks, and gasoline-powered heavy-duty
vehicles. In order to develop an overall emission factor for all gasoline-powered
vehicles, each of these classes had to be weighted according to its "relative travel,
allowing for the incorporation of new vehicles and scrappage of older vehicles in
the overall vehicle population, allowing for the deterioration of vehicles with age
and mileage, and allowing for differential travel as a function of vehicle age, "^
In order to take into consideration the control of motor vehicle emissions, the
emission factors are presented on a year-by-year basis and are based on applicable
Federal standards in effect as of 1971, including those proposed for 1973 and
1975. It is emphasized that the factors given in Table 3-1 are for the vehicle
population mix for the calendar year given and not for vehicles of that model year
only.
These emission factors are presented in Table .3-1 for two types of vehicle
operation conditions. Urban travel was assumed to be at an average speed of 25
miles per hour (40 kilometers per hour), beginning from a "cold start, " and all
rural travel was assumed to be at an average speed of 45 miles per hour (72. 5
kilometers per hour), beginning from a "hot start," Exhaust emissions of carbon
monoxide and hydrocarbons vary considerably with speed. If emission factors are
needed for speeds other than the assumed average speeds for urban and rural driv-
ing, Figures 3-1 and 3-2 should be used. For example, the emission factor for
hydrocarbon exhaust emissions under urban driving conditions in 1975 for a speed
of 10 miles per hour (16 kilometers per hour) would be 1. 79 times the exhaust
hydrocarbon emissions for that year.
Because legislation has only been proposed for hydrocarbons, carbon monox-
ide, particulates, and nitrogen oxides, it was not necessary to present the emis-
sions of other pollutants on a year-by-year basis. For this reason, emission
factors for sulfur oxides, aldehydes, and organic acids do not vary by year.
2/72 3-1
-------
Table 3-1. EMISSION FACTORS FOR GASOLINE-POWERED MOTOR VEHICLES6
EMISSION FACTOR RATING: A
.Emissions
Carbon monoxide*3
Urban
Rural
Hydrocarbons^
Evaporation
Crankcasec
Exhausts
Urban
Rural
Nitrogen oxides
(NOX as N02)b,i
Particulatesdjfi
Sulfur oxides {S02)f
Aldehydes (HCHOJ9
Organic acids (acetic)h
1960
g/mi
120
70
2.7
4.1
16
10.5
6.58
0.3
0,18
0.36
0.13
g/km
74.5
43.5
1.68
2.54
10.0
6.53
4.1
0.19
0.11
0.224
0,081
1965
g/mi
120
70
2.7
2.7
16
10.5
6.60
0.3
3/km
74.5
13.5
1.68
1.68
10.0
6.53
4.1
0.19
1970
g/mi
95
60
2.7
0.9
12
8
6.63
0.3
g/km
59.0
37.3
l.'61
0.56
7.45
5.0
4.12
0.19
1971
g/mi
90
55
2.3
0.45
11
7
6.47
0.3
g/km
56.0
34.2
1.43
0.28
6.83
4.35
4.02
0.19
1972
g/mi
85
50
2.3
0.45
9.5
6.5
6.17
0.3
g/km
52.8
31.0
1.43
0.28
5.9
4.04
3; 83
0.19
1973
g/mi
80
45
1.8
^0.32
8.5
6
5.75
0.3
g/km
49.7
28.0
1.12
0.2
5.28
3.72
3.57
0.19
1974
g/mi
75
40
1.8
0.22
7.2
5
5.55
0.3
g/km
46.6
24.8
1.12
0.14
4.5
3.10
3.45
0.19
1975
g/mi
60
35
1.4
0.22
6
4
4.90
0.1
g/km
37.2
21.7
0.87
0.14.
3.72
2.48
3.04
0.062
No legislation is in effect or has been proposed for
these pollutants* and thus only one factor is presented.
—
o
-n
y>
3
o
l\3
•^
ro
To convert emission factors to grams/gallon (kg/103 liters), assume the average gasoline-powered engines get 12.5 miles/
gallon {5.3 km/liter).
Reference 2. ;
...
Crankcase emissions for vehicles after 1962 are neglible. These factors are based on pre-1962 vehicles left in the
vehicle population.
ri -f • •
Reference 6.
eUrban factor = rural factor.
Based on sulfur content of 0.04 percent and a density of 6.17 Ib/gallon (0.74 kg/liter).
9References 7 through 9. : .
References 7, and 9 through 11.
Updated to reflect revised test cycle and test procedures current in July 1971.
-------
2.5
2.0
1.5
§ 1.0
0.5
16
24
SPEED, km/hr
32 40
48
56
DC
O
I
URBAN TRAVEL
10
15
20 25
SPEED, rai/hr
30
35
1.2
1.1
on
o
I 1-0
0.9
o
o
0.8
0.7
35
64
40
72
SPEED, km/hr
80
45
50
SPEED, rai/hr
55
96
104
RURAL TRAVEL
60
65
Figure 3-1. Speed adjustment graphs for carbon monoxide emission factors.
Emissions
Air pollutant emissions from, motor vehicles come from three principal
sources: exhaust, crankcase blow-by, and evaporation from the fuel tank and •
carburetor. It has been estimated that about 55 percent of the hydrocarbons come
from the engine exhaust, 25 percent from the blow-by, and 20 percent from
2/72
Mobile Combustion Sources
3-3
-------
16
2.5
2.0
1.5
3 l.Q
o
3; -
0.5
24
SPEED, km/hr '
32 40
48
56
OS
O
URBAN TRAVEL
10
15
20 25
-SPEED, mph
3D
35
1.2
56
1.1
OS
O
O
1.0
0.9
0.8
•0.7
35
64
40
72
SPEED, km/hr
80
45
104
RURAL TRAVEL
60
SO 55
SPEED, mph
Figure 3-2- Speed adjustment graphs (or hydrocarbon exhaust emission factors.
65
evaporation from the fuel tank and carburetor for an uncontrolled vehicle, where-
as essentially all of the carbon'monoxide and nitrogen oxides eome from the
engine exhaust, ** As a rough "approximation, the amount of partic'ulate matter
emitted in the blow-by is about one-third to one-half the amount emitted in the
exhaust. • .
3-4
E iSSIO FACTORS
2/72
-------
Evaporative Emissions - Emissions from the fuel tank result primarily from the
evaporation of gasoline in the vehicle tank. These emissions occur under both!
operating and stationary -conditions and are due to the temperature changes in the
tank fuel and changes in vapor volume that induce breathing through the tank ve,nt,
Carburetor emissions result under two separate conditions. Running losbes
occur during vehicle operation as a result of internal carburetor pressures tha|t
release hydrocarbon vapors through the external carburetor vents. Hot-soak
losses result from evaporation of the fuel in the carburetor "float bowl when the,
vehicle is stationary,
Crankcase Emissions 13 _ Gases vented from the engine crankcase through the !
road draft tube and oil filter tube are, if uncontrolled, the second largest sourtte
of hydrocarbon emissions. These emissions consist predominantly of engine :
blow-by gases, with some crankcase ventilation air and a very limited amount of
crankcase lubricant fumes.
Exhaust Emissions12' 13
In contrast to the evaporative and crankcase emissions, which are composed
predominantly of hydrocarbons, engine exhaust gases additionally contain carbon
monoxide, nitrogen oxides, and other combustion products. :
The primary factor influencing the formation of carbon monoxide and hydro-
carbons is the air/fuel ratio supplied to the engine. The concentrations of these
pollutants increase as the air/fuel ratio decreases. Nitrogen oxide formation ijg
influenced by combustion temperature and the amount of oxygen available for
reaction with nitrogen. Another major factor in the rate of release of these pol-
lutants is vehicle speed; hydrocarbon and carbon monoxide emissions decrease1
with an increase in vehicle speed, whereas nitrogen oxides are independent of
average vehicle speed.
Particulates, consisting primarily of lead compounds, carbon particles, and
motor oil, are also emitted from the engine exhaust. Because of the complex i
relationships involved, the effects of engine design and other factors on particulate
emissions are not well known. Sulfur oxide emissions from engine exhaust are, a
function of the sulfur content of the gasoline. Because of the low average sulfuf
content of gasoline (0. 035 percent), however, this is not normally a major concern.
DIESEL-POWERED MOTOR VEHICLES
General14' 15
Diesel engines have been divided into three primary user categories—heavy-
duty trucks, buses, and locomotives. The operating characteristics of a diesel
engine are significantly different from the previously discussed gasoline engine,
In a diesel engine, fuel and air are not mixed before they enter the cylinder.
The air is drawn through an intake valve and then compressed. The fuel is then
injected as a spray into this high-temperature air and ignites without the aid of a
spark. Power output of the diesel engines is controlled by the amount of fuel
injected for each cycle.
2/72 Mobile Combustion Sources 3-5
-------
Emissions
Diesel trucks and buses emit pollutants from the same sources as gasoline
systems: blow-by, evaporation, and exhaust. Blow-by is practically eliminated in
the diesel because only air is in the cylinder during the compression stroke, The
low volatility of diesel fuel along with the use of closed injection systems essen-
tially eliminates evaporation losses in diesel systems.
Exhaust emissions from diesel engines have the same general character-
istics as auto exhausts. Concentrations of some of the pollutants, however, may
vary considerably. Emissions of sulfur dioxide are a direct function of the fuel
composition. Thus, because of the higher average sulfur content of diesel fuel
(0.35 percent) as compared to gasoline (0,035 percent), sulfur dioxide emissions
from diesel exhausts^"1 •"•' are relatively higher.
Because diesel engines have more complete combustion and use less volatile
fuels than spark-ignited engines, their HC and CO emissions are relatively low.
Because hydrocarbons in diesel exhaust are largely just unburned diesel fuel, their
emissions are related to the volume of fuel sprayed into the combustion chamber.
Recently improved needle valve injectors reduce the amount of fuel that can be
burned. These valves can reduce hydrocarbon emissions by as much as 50 per-
cent. I' Both the high temperatures and the large excesses of oxygen involved in
diesel combustion are conducive to the high nitrogen oxide emissions. 1^
Particulates from diesel exhaust are in two major forms - black smoke and
white smoke. White smoke is emitted when the fuel droplets are kept cool in an
environment abundant in oxygen (cold starts). Black smoke, however, is emitted
when the fuel droplets are subjected to high temperatures in an environment lack-
ing in oxygen (road conditions), •"•'
Emission factors for the three classes of diesel engines, trucks, -buses, and
locomotives, are presented in Table 3-2,
AIRCRAFT
General22
Aircraft engines are of two major categories; reciprocating, or piston,
engines and gas turbine engines. There are four basic types of gas turbine engines
used for aircraft propulsion; turbofan, turboprop, turbojet, and turboshaft. The
gas turbine engine in general consists of a compressor, a combustion chamber,
and a turbine. Air entering the forward end of the engine is compressed and then
heated by burning fuel. The major portion of the energy in the heated air stream
is used for aircraft propulsion. Part of the energy is expended in driving the
turbine, which, in turn, drives the compressor.
The basic element in piston engine aircraft is the combustion chamber, or
cylinder, in which fuel and air mixtures are burned and from which energy is
extracted through a piston and crank mechanism that drives a propeller. Nearly
all aircraft piston engines have two or more cylinders and are generally classified
according to their cylinder arrangements - either "opposed" or "radial. " Opposed
engines are installed in most light or utility aircraft. Radial engines are used
mainly in large transport aircraft.
3-6 E ISSIO FACTORS 3/72
-------
Table 3-2. EMISSION FACTORS FOR DIESEL ENGINES3
EMISSION FACTOR RATING: B
Pollutant
Particulates
Oxides of sulfur
(SOX as S02)d
Carbon monoxide
Hydrocarbons
Oxides of nitrogen
(NOX as NOg)
Aldehydes (as HCHO)
Organic acids
Heavy-duty truck and bus
enginesb
lb/103 gal
13
27
225
37
370
3'
3
kg/103 liters
1,56
3.24
27.0 .
4.44
44,4
0.36
0.36
Locomotives6
lb/103 gal
25
65
70
50
75
4
7
kg/103 liters
3
7.8
8,4
6.0
9.0
0.48
0.84
Data presented in this table are based on weighting factors applied to actual
tests conducted at various load and idle conditions with an average gross
vehicle weight of 30 tons (27.2 MT) and fuel consumption of 5.0 mi/gal
(2,2 km/liter).
Reference 20.
GBased on analysis of data from Reference 21.
Data for trucks and buses based on average sulfur content of 0.20 percent,-and '
for locomotives, on average sulfur content of 0.5 percent.
A representative list of various models of aircraft by type is shown in
Table 3-3, Both turbofan aircraft and piston engine aircraft have been further sub-
divided into classes depending on the size of the aircraft. Long-range jets
normally have approximately 18, 000 pounds maximum thrust, whereas medium-
range jets have about 14,000 pounds maximum thrust. For piston engines, this
division is more pronounced. The large transport piston engines are in the
500 to 3,000 horsepower range, whereas the smaller piston engines have less than
500 horsepower,
Emissions
Emissions from the various types of aircraft are presented in Table 3-4. •
Emission factors are presented on the basis of pounds (kilograms) per landing-
take-off (LTO) cycle per engine. An LTO cycle includes all normal operational '••
modes performed by an aircraft between the time it descends through an altitude
of 3, 500 feet (1, 100 meters) above the runway on its approach to the time it
subsequently reaches the 3,500-foot (1100-meter) altitude after take-off. It should
be made clear that the term operation used by the FAA to describe either a landing
or a take-off is not the same as the LTO cycle. Two operations are involved in
one LTO cycle. The LTO cycle incorporates the ground operations of idle, taxi*
landing run, take-off run and the flight operations of take-off and climb-out to
3, 500 feet (1, 100 meters) and approach from 3, 500 feet (1, 100 meters) to touch^
down,
The rates of emission of air pollutants by aircraft engines, as with other
internal combustion engines, are related to the fuel consumption rate. The aver-
age amount of fuel used for each phase of an LTO cycle is shown in Table 3-5.
2/72
Mobile Combustion Sources
3-7
-------
Table 3-3. AIRCRAFT CLASSIFICATION SYSTEM8
Aircraft type
Turbofan
Jumbo jet
Long range
Medium range
Turbojet
Turboprop
Turboshaft
Piston
Transport
Light
Examples of models
Boeing 747, Douglas DC-ID,
Lockheed L-1011
Boeing 707, Douglas DC-8
Boeing 727, Douglas DC-9
Boeing 707, 720 Douglas DC-8
Com/air 580, Electra L-188,
Fairchild Hi Tier FH-227
Sikorsky S-61, Vertol 107
Douglas DC-6, Lockheed L-1049
Cessna 210, Piper 32-300
Engines most commonly used
Pratt & Whitney JT-9D
Pratt & Whitney JT-3D
Pratt & Whitney JT-8D
Pratt & Whitney JT-3C
Pratt & Whitney JT-4A
General Electric CJ 805-38
General Motors-Aliison
501-Dl3
General Electric CT58
Pratt & Whitney R-2800
Continental 10-520-A
References 22 through 24,
These data can be used in conjunction, with the emission factors presented in
Table 3-4 to determine an emission factor in pounds per gallon (kilograms per
liter) per engine,
VESSELS
General29
Fuel oil is the primary fuel used in vessels. It powers steamships, motor
ships, and gas -turbine -powered ships. Gas'turbines presently are not. in wide-
spread use and are thus.not included in this section,' However,,, within the next few
years they will become increasingly common. = :
Steamships are any ships that have steam turbines driven by an external com-
bustion engine. Motor ships, on the other hand, have internal combustion engines
operated on the diesel cycle.
Emissions
The air pollutant emissions resulting from vessel operations may he divided
into two groups: emissions that occur as the ship is underway and emissions that
occur when the ship is dockside or in-berth.
Underway emissions may vary considerably for vessels that are maneuvering
or docking because of the varying fuel 'consumption. . During such a time a vessel
is operated under a wide range of power demands for a period of 15 minutes to
1 hour. The high demand may be 15 times the low demand; however, once the
vessel has reached and sustained a normal operation speed, the fuel consumed is
reasonably constant. Table 3-6 shows that 29 to 65 gallons of fuel oil is consumed
per nautical mile (60 to 133 liters per kilometer) for steamships and 7 to 30 gallons
of oil, per nautical mile (14 to 62 liters per kilometer) for motorships.
3-8
E ISS10 FACTORS
2/72
-------
ro
ro
o
o
CO
o
o
(O
(/I
Table 3-4. EMISSION FACTORS FOR AIRCRAFT
(Ib/engine - LTD cycle and kg/engine - LTO cycle)
EMISSION FACTOR RATING: A
Type of aircraft
Turbofan
Jumbo jetb>c
Long range^'6
Medium ranged »f
Turbo jetd'h
Turboprop1" *3
Turboshaft^.l
Piston
Transport^'1"
Light"
Participates
Ib
10
8
7
11
6
3
5
0,2
kg
4.54
3.63
3.18
5.0
2.72
1.36
2.27
0.09
Sulfur oxides
Ib
2
2
2
2
1
1
0,13
0.01
- kg
0.91
0.91
0.91
0.91
0.45
0.45
o.osi
0.0045
Carbon
monoxide
Ib
28
26
16
24
2
6
303
12
kg
12.7
11.8
7.3
10.9
0.91
2.72
137.0
5.5
Hydrocarbons
Ib
3
17
(0.6 to 86)9
26
3
0.5
40
0.4
kg
1.36
7.7
0.27 to 39.09
11.8
1.36
0.23
18.2
0.18
Nitrogen
oxjdes
Ib
6
5
7
5
5
0.6
0.4
0.2
kg
2.72
2.27
3.18
2.27
2.27
0.27
0.18
0.09
Aldehydes3
lb
0.5
0.5
0.5
1.0
0.2
0.2
0,2
0.1
ki
0.23
0.23
0.23
0.45
0.09
0.09
0.09
0.05
Estimates based on old data in Reference 25.
Reference 26.
cBased on Pratt & Whitney JT-9D engine.
References 26 and 27.
eBased on Pratt & Whitney JT-3D engine.
fBased on Pratt & Whitney JT-8D engine.
50 (22,7) for uncontrolled jets and 3 {1,36) for jets equipped with smoke burner cans.
Based m General Electric CJ805-3B, Pratt & Whitney JT-3C-S, and Pratt & Whitney JT-4A engines.
Reference 27.
••'Based on General Motors-Allison 501-D13 engine. ... _
Reference 22.
Based on General Electric CT 58 engine.
mTypical engine used is the Pratt & Wtntney fl-280&,
"References 22 and 28,
-------
Table 3-5. FUEL CONSUMPTION RATES FOR VARIOUS TYPES OF AIRCRAFLDURIKG LANDING AND TAKE-OFF CYCLE
Type of
aircraft
Turbo fan
Jumbo jeta
Long range^
Medium rangeb
Turbojet0
Turboprop^
Turboshaftc
Piston
Transport
Light0
Taxi and idle
gal /engine
75
35
35
SO
30.
5
10
1
1 iters/engine
284
133
133
189
. 114
18.9
37.9
3.79
Landing and approach
gal/engine
.
TOO
30
40
• 50
'15"
0
5
0.2
liters/engine
379
114 • = •
151 '
-
189 :
_ • 56.8 ' '• '
0
18.9
0.76 •
Take-off and climb-out
gal/engine
150
115
95
. 120
' 25
20
30
1
1 iters/engine
568
435
360 • .
455
'"95
96
114
3.79
Total LTO cycle
gal /engine
325
180
170 -
220
. 70
25
45
2.2
1 iters/engine
1,230
' 682
644
833 „
265
- . 94.6
170
' 8.33
3*
O
o
•so
Reference 26.
^Reference 27.
"Reference 22.
IVJ
•»».•
IS*
-------
Table 3-6, FUEL CONSUMPTION RATES FOR STEAMSHIPS AND MOTOR SHIPS*
Fyel consumption
Underway
Ib/hp-hr
kg/hp-hr
gal/naut mile
liters/kilometer
In-berth
gal /day
liters/day
Steamships
Range
0.51 to 0,65
0.23 to 0.29
29 to 65
59.4 to 133
840 to 3,800
3,192 to 14,400
Average
0.57
0.26
44
90
1,900
7,200
Motor ships
Range
0.28 to 0.44
0.13 to 0.20
7 to 30
14 to 62
240 to 1,260
910 to 4,800
Average
0.34
0.15
19
38.8
660
2,500
Reference 29.
Unless a ship goes immediately into drydock or is otherwise out of operation;
after arrival in port, she continues her emissions at dockside. Power must be
generated for the ship's light, heat, pumps, refrigeration, ventilation, etc. A
few steamships use auxiliary engines to supply power, but they generally operate
one or two main boilers under reduced draft and lowered fuel rates, a. much less
efficient process. Motor ships generally use diesel-powered generators to furnish
auxiliary power.
As shown in Table 3-6, fuel oil consumption at dockside varies appreciably.
Based on the data presented in this table and the emission factors for residual
fuel-oil combustion and diesel-oil combustion, emission factors have been
determined for vessels and are presented in Table 3-7.
Table 3-7. EMISSION FACTORS FOR VESSELS
EMISSION FACTOR RATING: D •
Pollutant
Parti eul ate
Sulfur dioxide
Sulfur trioxidec
Carbon monoxide
Hydrocarbons
Nitrogen oxides (N02)
Aldehydes (HCHO)
Steamships9
Underway
Ib/mi kg/km
0.4
7S
0.1S
0.002
0.2
4.6
0.04
0.098
1.71S
0.02S
0.0005
0.05
1.13
0.01
In-berth
Ib/day
15
300S
45
0.08
9
200
2
kg/day
6.8
136S
1.8S
0.036
4.1
90.7
0.9
—in: • . r
Motor ships0
Underway
Ib/mi
2
(SOX) 1-5
1.2
0.9
1.4
0.07
kg/km
0.49
0.37
0.29
0.22
0.34
0.017
In-berth
Ib/day
16.5
43
46
33
50
2.6
kg/day
7.5
19.5
20.8
14.9
22.7
1.2
Based on data in Table 3-6 and emission factors for fuel oil.
3Based on data in Table 3-6 and emission factors for diesel fuel.
"S = weight percent sulfur in fuel; assumed to be 0.5 percent for diesel.
2/72
Mobile Combustion Sources
3-11
-------
REFERENCES FOR CHAPTER 3
1. Nationwide Inventory of Air Pollutant Emissions, 1.968. U.S. DREW, PHS,
EHS, National Air Pollution Control Administration. Raleigh, North Carolina.
Publication No. AP-73. August 1970.
2. Cernansky, N. P. and K.. Goodman. Estimating Motor Vehicle Emissions on
a Regional Basis. Presented at the 63rd Annual Meeting of the Air Pollution
Control Association, June 14-18, 1970.
3. Control of Air Pollution from New Motor Vehicles and New Motor Vehicle
Engines. Federal Register Part II. 31(61):5170-5238, March 31, 1966.
4. "Control of Air Pollution from New Motor Vehicles and New Motor Vehicle
Engines. Federal Register Part II. 3_3(108):8303-8324, June 4, 1968.
5. Control of Air Pollution from New Motor Vehicles and New Motor Vehicle
Engines. Federal Register Part II. 35(28): 2791, February 10, 1970.
6. Private communication with N. P. Cernansky, U.S. DHEW, PHS, EHS, Nat-
ional Air Pollution Control Administration, Durham, N. C. June 1970.
7. Magill, P. L. and R. W. Benoliel. Air Pollution in Los Angeles County: Con-
tribution of Industrial Products. Ind. Eng. Chem. 44;1347-1352, June 1952.
8. MacChee, R.D., J. R. Taylor, and R.L. Chaney. Some Data on Particulates
from Fuel Oil Burning. Los Angeles County Air Pollution Control District, "
Presented at APCA Semiannual Technical Conference, San Francisco, Calif-
ornia. November 1957,
9. Second Technical and Administrative Repqrt on Air Pollution Control in Lps
Angeles County. Air Pollution Control District, County qf Los Angeles, Cal-
ifornia. 1950-1951.
10. Larson, G. P. , G.I. Fischer, .and W. J. Hamming. Evaluating Sources of Air
Pollution. Ind. Eng. Chem. 45jl070-1074, May 1953.
11. Magill, .P. L. , F.R. Holden, and C. Ackley. Air Pollution Handbook. New
York, McGraw-Hill, 1956., p. 1-47.
12, The Automobile and Air Pollution: A Program for Progress, Part II. U.S.
Department of Commerce. Washington, D. C. December 1967.
13. .Rose, A.H. , Jr. Summary Report on Vehicular Emissions and Their Control,
U.S. DHEW, PHS. Cincinnati, Ohio. October 1965.
14. The Automobile and Air Pollution: A Program for Progress. Part II. U.S.-.
Department of Commerce. Washington, D. C. December 1967, p. 34,
15, Control Techniques for Carbon Monoxide, Nitrogen Oxides, and Hydrocarbons
From Mobile Sources. U.S. DHEW, PHS, EHS, National Air Pollution Con-
trol Administration. Washington, D. C. Publication No. AP-66. March 1970.
p. 2-9 through 2-11. .
3-12 E ISSIO FACTORS 2/72
-------
16, McConnell, G, andH.E, Howells, Diesel Fuel Properties and Exhaust Gap-
Distant Relations? Society of Automotive Engineers. January 1967,
17. Motor Gasolines, Summer 1969. Mineral Industry Surveys, U.S. Department
of the Interior, Bureau of Mines, Washington, D. C. 1970. p. 5.
18, Merrion, D. F, Diesel and Turbine Driven Vehicles and Air Pollution. Pr$-
sented at University of Missouri Air Pollution Conference, Columbia, Mis +
souri. November 18, 1969.
19. Hum, R, W. The Diesel Fuel Involvement in Air Pollution, Presented at the
National Fuels and -Lubricants Meeting, New York, N. Y, September IT-IS,,
1969.
20, Youngj T, C, Unpublished emission factor data on diesel engines. Engine
Manufacturers Association's (EMA) Emissions Standards Committee.
Chicago, 111. May 18, 1971.
21, Unpublished test data on locomotive engines. General Motors Corporation^
Warren, Michigan. July 1970,
22. Nature and Control of Aircraft Engine Exhaust Emissions, Northern Re- •
search and Engineering Corporation, Prepared for National Air Pollution
Control Administration under Contract No. PH22-68-27. Cambridge, Mags.
November 1968,
23, Airport Activity Statistics of Certificated Route Air Carriers. U.S. Depart-
ment of Transportation, Federal Aviation Administration, Washington, D» C.
December 1967. p. xi,
24. Private communication on aircraft engine classification with T. Horeff, Ftd-
eral Aviation Administration. May 13, 1970.
25. Duprey, R, L. Compilation of Air Pollutant Emission Factors. U.S. DHEJW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42, 1968. p. 49,
26. Bristol, C. W. Unpublished test results on jet aircraft. Pratt & Whitney ,
Corporation, Hartford, Connecticut. 1970.
27. George, R.E. , J. A. Verssen, andR.L. Chass, Jet Aircraft: A Growing
Pollution Source. J. Air Pollution Control Assoc. _l_9Jll);847-855, November
1969.
28. Zegel, W,C. Unpublished progress report on light piston engine aircraft.
Scott Research Laboratories. Plumsteadville, P . Prepared for National
Air Pollution Control Administration under Contract No, CPA 22-69-129.
July 10, 1970.
29. Pearson, J. R. Ships As Sources of Emissions. Presented at the Annu 1
Meeting of the Pacific Northwest International Section of the Air Pollution
Control Association. Portland, Oregon, November 1969.
2/72 Mobile Combustion Sources 3-13
-------
30. Standard Distillate Fuel for Ship Propulsion. U.S. Department of the Navy,
Report of a Committee to the Secretary of the Navy. Washington, D,C, Oct-
ober 1968.
31. GTS Admiral William M. Callahan Performance .Results. Diesel and Gas
Turbine Progress. 35(9)178, September 1969.
3-14 E ISSIO FACTORS 2/72
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4. EVAPORATION LOSS SOURCES
Evaporation losses include the organic solvents emitted from dry-cleaning
plants and surf ace-coating operations as well as the volatile matter in petroleum
products. This section presents the hydrocarbon emissions from these sources,
including petroleum storage and gasoline marketing. Where possible the effect of
controls to reduce the emissions of organic compounds has been shown.
DRY CLEANING
General1
Clothing and other textiles may be cleaned by treating them with organic
solvents. This treatment process involves agitating the clothing in a solvent bath,
rinsing with clean solvent, and drying with -warm air.
There are basically two types of dry-cleaning installations: those using
petroleum solvents [Stoddard and 140° F (60° C)] and those using chlorinated
synthetic solvents (perchloroethylene). The trend in dry-cleaning operations today
is toward smaller package operations located in shopping centers and suburban
business districts that handle approximately 1500 pounds (675 kg) of clothes per
week on the average. These plants almost exclusively use perchloroethylene,
•whereas the older, larger dry-cleaning plants use petroleum solvents. It has been
estimated that perchloroethylene is used on 50 percent of the weight of clothes dry-
cleaned in the United States today and that 70 percent of the dry-cleaning plants use
perchloroethylene. ^
Emissions and Controls1
The major source of hydrocarbon emissions in dry cleaning is the tumbler
through which hot air is circulated to dry the clothes. Drying leads to vaporiaa-
tion of the solvent and consequent emissions to the atmosphere, unless control
equipment is used. The primary control element in use in synthetic solvent plants
is a water-cooled condenser that is an integral part of the closed cycle in a tumbler
or drying system. Up to 95 percent of the solvent that is evaporated from the
clothing is recovered here. About half of the remaining solvent is then recovered
in an activated-carbon adsorber, giving an overall control efficiency of 97 to 98
percent. There are no commercially available control units for solvent recovery
in petroleum-based plants because it is not economical to recover the vapors.
Emission factors for dry-cleaning operations are shown in Table 4-1,
It has been estimated that about 18 pounds (8. 2 kilograms) per capita per
year of clothes are cleaned in moderate climates-' and about 25 pounds (11. 3 kilo-
grams) per capita per year, in colder areas. ^ Based on this information and the
facts that 50 percent of all solvents used are petroleum based and 25 percent of
the synthetic solvent plants are controlled, •* emission factors can be determined
on a pounds- (kilograms-) per-capita basis. Thus approximately 2 pounds (0. 9
kilogram) per capita per year are emitted from dry-cleaning plants in moderate
climates and 2.7 pounds (1.23 kilograms) per capita per year in colder areas.
2/72 4-1
-------
Table 4-1, HYDROCARBON EMISSION FACTORS FOR DRY-CLEANING
OPERATIONS
EMISSION FACTOR RATING: C
Control
Uncontrolled3
Average control
Good control1*
Petrol eum
solvents
Ib/ton
305
'kg/MT-'
152,5 •
Synthetic
solvents •
Ib/ton
210
95
35
kg/MT
105
47.5
17.5
References 2, 4, 6, and 7.
Reference 6.
cReference 8. • .
SURFACE COATING
Process Description 9, 10
Surf ace-coating operations primarily involve the application of paint, varnish,
lacquer, or paint primer for decorative or protective purposes, .This is accom-
plished by brushing, rolling, spraying, flow coating, and dipping. Some of the
industries involved in surface-coating operations are automobile assemblies, air-
craft companies, container manufacturers, furniture manufacturers, appliance
manufacturers, job enamelers, automobile repainters, and plastic products
manufacturers.
Emissions and Controls
1
Emissions of hydrocarbons occur in surface-coating operations because of
the evaporation of the paint vehicles, thinners, and solvents used-to facilitate the
application of the coatings. The major factor affecting these emissions is the
amount of volatile matter contained in the coating. The volatile portion of most
common surface coatings averages approximately 50-percent, and most, if not all,
of this is emitted during the application and drying of the coating. The compounds
released include aliphatic and aromatic hydrocarbons, alcohols, ketones, esters,
alkyl and aryl hydrocarbon solvents, and mineral spirits. Table 4-2 presents emis-
sion factors for surface-coating operations.
Control of the gaseous emissions can be accomplished by the use of adsorbers
(activated carbon) or afterburners. The collection efficiency of activated carbon
has been reported at 90 percent or greater. Water curtains or filter pads have
little or no effect on escaping solvent vapors; they are -widely used, however, to
stop paint particulate emissions,
PETROLEUM STORAGE
General 11,12
In the storage and handling of crude oil and its products, evaporation losses
may occur. These losses may be divided into two categories: breathing loss and
4-2
E ISSIO FACTORS
2/72
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Table 4-2. GASEOUS.HYDROCARBON EMISSION
FACTORS FOR SURFACE-COATING APPLICATION
EMISSION FACTOR RATING: B
Type of coating
Paint
Varnish and shellac
Lacquer
Enamel
Primer (zinc chromate)
Emissions'3
Ib/ton
1,120
1,000
1,540
840
1,320
kg/MT
560
500
770
420
660
Reference 9.
Reported as undefined hydrocarbons, usually
organic solvents both aryl and alkyl.
Paints weigh 10 to 15 pounds per gallon
(1.2 to 1.9 kilograms per liter); varnishes
weigh about 7 pounds per gallon (0.84 kilo-
gram per liter).
working loss. Breathing losses are associated with the thermal expansion and con-
traction, of the vapor space resulting from the daily temperature cycle, Workiqg
losses are associated with a change in. liquid level in the tank (filling or emptyimg),,
Emissions
There are two major classifications of tanks used to store petroleum pro-<
ducts: fixed-roof tanks and floating-roof tanks. The evaporation losses from both
of these types of tanks depend on a number of factors, such as type of product
stored (gasoline or crude oil), vapor pressure of the stored product, average
temperature of the stored product, tank diameter and construction, color of tanjk
paint, and average wind velocity of the area. In order to estimate emissions frjom
a given tank, References 11 and 13 should be used. An average factor can be <
obtained, however, by making a few assumptions. These average factors for bpth
breathing losses and working losses for fixed-roof and floating-roof tanks are ,
presented in Table 4-3.
GASOLINE MARKETING
General
In the marketing of gasoline from the original storage and distribution to the
final use in motor vehicles, there are five major points of emission;
1, Breathing and working losses from storage tanks at refineries and bulk
terminals.
2. Filling losses from loading-tank conveyances at refineries and bulk
terminals (included under working losses from storage tanks),
3. Filling losses, from loading underground storage tanks at service
stations.
2/72
Evaporation Loss Sources
-------
Table 4-3. .HYDROCARBON EMISSION FACTORS FOR EVAPORATION LOSSES
. FROM THE STORAGE OF PETROLEUM PRODUCTS
EMISSION FACTOR RATING: C
Type of tank3
Fixed roof
Breathing loss
Working loss 'c
Floating roof
Breathing loss
Working loss
Units
lb/day-1000 gal
storage capacity
kg/day-1 000 liters
storage capacity
.lb/1000 gal
throughput
kg/1000 liters
throughput
1 b/day-tank
kg/day-tank
lb/1000 gal
throughput
kg/ 1000 liters
throughput
Type of material stored
Gasoline or finished
petroleum product
0.4
0.05
11
1.32
140(40 to 210)e
63.5
Neg
Neg
Crude oil
0.3
0.04
• 8 . '
0.96
100(30 to 160)f
45.4
Neg
Neg
aFor tanks equipped with vapor-recovery systems, emissions are negligible.
Reference 11,
c • • 14 ••
An average turnover rate for petroleum storage is approximately 6. Thus,
the throughput is equal to 6 times the capacity.
Reference 13.
e!40 (63.5) based on average conditions and tank diameter of 100 ft (30.5 m);
use 40 (18.1 kg) for smaller tanks, 50 ft (15.3 m) diameter; use 210 (95
kg) for larger tanks, 150 ft (45.8 m) diameter.
fUse 30 (13.6 kg) for smaller tanks, 50 ft (15.3 m) diameter; use 160 (72.5 .'
kg) for larger tanks, 150 ft (45.8 m) diameter.
4. Spillage and filling losses in filling automobile gas tanks at service "
stations. • . ; •
5. Evaporative losses from the carburetor and gas tank of motor vehicles.
In this section only points 3 and 4'will be discussed, Points 1 and 2 have been
covered in the section on petroleum storage and point 5 is covered under the sec-
tion on gasoline-powered motor vehicles. . .
E issions and Controls
The emissions'associated with gasoline marketing are primarily- vapors
expelled from- a tank by displacement as a result of filling. The vapor losses" are .
4-4
E ISSIO FACTORS
2/72
-------
a function of the method• of filling the tank (either splash or submerged fill).
Splash and submerged fill have been defined as follows: "In splash fill the gasoline
enters the top of the fill pipe and then has a free fall to the liquid surface in the
tank. The free falling tends to break up the liquid stream into droplets. As these
droplets strike the liquid surface, they carry entrained air into the liquid, and a
'boiling' action results as this air escapes up through the liquid surface. The net
effect of these actions is the creation of additional vapors in the tank. In submerged
filling, the gasoline flows to the bottom of the tank through the fill pipes and enters
below the surface of the liquid. This method of filling creates very little disturb-
ance in the liquid bath and, consequently, less vapor formation than splash
filling. "15
Emission factors for gasoline marketing are shown in Table 4-4. As is shown
in footnote "bj " if a vapor-return system in which the underground tank vent line is
left open is used, losses from filling service station tanks can be greatly reduced.
If a displacement type, closed vapor-return system is employed, the losses can be
almost completely eliminated.
Table 4-4. EMISSION FACTORS FOR EVAPORATION LOSSES
FROM GASOLINE MARKETING
EMISSION FACTOR RATING: B
Point of emission
Filling service station tanks3*'3
Splash fill
Submerged fill
501 splash fill and 501 sub-
merged fill
Filling automobile tanks'-
Emissions
lb/103 gal
12
7
9
12
kg/103 liters
1.44
0,84
1 .08
1,44
Reference 15.
3With a vapor return, open-system emissions can be reduced to
approximately 0.8 lb/103 gal (0.096 kg/103 liters), and
closed-system emissions are negligible.
"References 16 and 17.
REFERENCES FOR CHAPTER 4
1, Air Pollutant Emission Factors, Final Report. Resources Research, Incor-
porated. Prepared for National Air Pollution Control Administration.under
Contract No. CPA-22-69-119, April 1970.
2. Communication with the National Institute of Dry Cleaning. 1969.
3. Duprey, R.L,. Compilation of Air Pollutant Emission Factors, U.S. DHEW,
PHS, National Center for Air Pollution Control, Durham, N, C. PHS Publi-
cation No. 999-AP-42. 1968. p. 46.
2/72
Evaporation Loss Sources
' 4-5
-------
4, Dry Cleaning Plant Survey, Michigan Department of Health. Kent County,
Michigan, 1965.
5. ' Communication on Dry Cleaning Plants with S. Landon, Washer Machinery
Corporation, June 1968, • • .
6. Chass, R. Li.', C.V. Kanter, and J. H.'Elliot. Contribution of Solvents to
Air Pollution and Methods-for Controlling Their Emissions. J. Air Pollu-
tion Control Assoc. 13j 64-72", February" 1963. • '
1, Bi-State Study of Air Pollution in the Chicagd Metropolitan Area, 111. Dept,
of Public Health, Ind. State Board of Health, and Purdue University. Chicago,
Illinois. 1957-59. - '
8, Communication on Emissions from Dry Cleaning Plants with A, Netzley, Los
Angeles County Air Pollution Control District. Los Angeles, California.
July 1968.
9. Weiss, S. F. Surface Coating Operations. In: Air Pollution Engineering Manual,
Danielson, J. A. '(ed.). U.S. DHEW, PHSS National Center lor Air Pollution
Control. Cincinnati, Ohio, Publication No. 999-AP-40. 1967, p. 387-390. .
10. Control Techniques for Hydrocarbon and'Qrganic Gases from Stationary
Sources, TJYS. DHEW, PHS, EHS, National Air Pollution Control Administra-.
tion. Washington, D..C. Publication No. AP-68. October 1969, Chapter 7. 6.
11. Evaporation Loss from Fixed Roof" Tanks.. American Petroleum Institute,
New York, N. Y. API Bulletin No. 2518. June 1962. -
IE. Evaporative Loss in the Petroleum Industry: Causes and Control, American
Petroleum Institute, New York, N.Y. API Bulletin No. 2513, . February 1959.
13, Evaporation Loss from Floating Roof Tanks, .American Petroleum Institute,
New York, N, Y, API Bulletin No. 2517. February 1962.
14, Tentative Methods of Measuring Evaporation Loss from Petroleum Tanks and
Transportation Equipment. American Petroleum Institute,' New York, N.Y."
API Bulletin No.-2512. July 1957.
15. Chass, R.'L. et al. Emissions from-Underground Gasoline Storage Tanks.
J. Air Pollution Control Assoc. 13:524-530, November 1963.
16, MacKnight, R,A. et al. , Emissions of Olefins from Evaporation of Gasoline
' and Significant Factors Affecting Production of Low Olefin Gasolines. Un-
published report. 'Los Angeles'Air Pollution Control "District, Lo's Angeles,"
California. March 1959, " . •
17. Clean Air Quarterly. 8:1, State .of California Department of Health, Bureau'
of~Air Sanitation,, March 1964, . . ...
4-6 E ISSIO FACTORS 2/72
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5. CHEMICAL PROCESS INDUSTRY
This section deals with emissions from the manufacture and/or use of chem-
icals or chemical products. Potential emissions from many of these processes are
high, but because of the nature of the compounds they are usually recovered as an
economic necessity,, In other cases, the manufacturing operation is run as a
closed system allowing little or no escape to the atmosphere,
In general, the emissions that reach the atmosphere from chemical processes
are primarily gaseous and are controlled by incineration, adsorption, or absorp-
'tion. In some cases, particulate emissions may also be a problem. The particu-
lates emitted are generally extremely small and require very efficient treatment
for removal. Emission data from chemical processes are sparse. It was there-
fore necessary frequently to form estimates of emission factors based on material
balances, yields, or similar processes.
ADIPIC ACID
Process Description1
Adipic acid, COOH • (CH2>4 " COOH, is a dibasic acid used in the manu-
facture of synthetic fibers. The acid is made in a continuous two-step process.
In the first step, cyclohexane is oxidized by air over a catalyst to a mixture of
cyclohexanol and cyclohexanone. In the second step, adipic acid is made by the
catalytic oxidation of the eyclohexanol-cyclohexanone mixture using 45 to 55 per-
cent nitric acid. The final product is then purified by crystallization,
Emissions
The only significant emissions from the manufacture of adipic acid are nitro-
gen oxides. In oxidizing the cyclohexanol/cyclohexanone, nitric acid is reduced to
unrecoverable N£O and potentially recoverable NO and NO2. This NO and NOz can
be emitted into the atmosphere. Table 5-1 shows typical emissions of NO and
from an adrnic acid plant.
Table 5-1. EMISSION FACTORS FOR AN ADIPIC ACID PLANT
WITHOUT CONTROL EQUIPMENT
EMISSION FACTOR RATING: D
Source
Oxidation
of eyelohexanol/cyclohexanone*
Nitrogen oxides
(NO.NQ2) emissions
Ib/ton
12
kg/MT"
6
Reference 1.
2/72 5-1
-------
AMMONIA
Process Descriptio 3
The manufacture of ammonia (NHj) is accomplished primarily by the catalytic
reaction of hydrogen and nitrogen at high temperatures and pressures. In a typical
plant a hydrocarbon feed stream (usually natural gas) is desulfurized, mixed with
steam, and catalytically reformed to carbon monoxide and hydrogen. Air is intro-
duced into the secondary reformer to supply oxygen and provide a nitrogen to hydro-
gen ratio of 1 to 3. The gases then enter a two-stage shift converter that allows the
carbon monoxide to react with water vapor to form carbon dioxide and hydrogen.
The gas stream is next scrubbed to yield a gas containing less than 1 percent CQ2-
A methanator may be uaed to convert quantities of unreacted CO to inert CH4 before
the gases, now largely nitrogen and hydrogen in a ratio of 1 to 3, are compressed
and passed to the converter. Alternatively, the gases leaving the CO2 scrubber
may pass through a CO scrubber and then to the converter. The synthesis gases
finally react in the converter to form ammonia,
Emissions a d Controls3
When a carbon monoxide scrubber is used before sending the gas to the con-
verter, the regenerator offgases contain significant amounts of carbon monoxide
(73 percent) and ammonia (4 percent). This gas maybe scrubbed to recover
ammonia and then burned to utilize the CO fuel value, **
The converted ammonia gases are partially recycled, and the balance is
cooled and compressed to liquefy the ammonia. The non-condensable portion of
the gas stream, consisting of unreacted nitrogen, hydrogen, and traces of inerts
such as methane, carbon monoxide, and argon, is largely recycled to the con-
verter. However, to prevent the accumulation of these inerts, some of ±he non-
condensable gases must be purged from the system.
The purge or bleed-off gas stream contains about 15 percent ammonia.1*
Another source of ammonia is the gases from the loading and storage operations.
These gases may be scrubbed with water to reduce the atmospheric emissions.
In addition, emissions of CO and ammonia5 can occur from plants equipped with
CO-scrubbing systems. Emission factors are presented in Table 5-2,
CARBON BLACK
Carbon black is produced by the reaction of a hydrocarbon fuel such as oil
or gas, or both, with a limited supply of air at temperatures of 2500° to 3000° F
(1370° to 1650°C}. Part of the fuel is burned to CC^, CO, and water, thus
generating heat for the combustion of fresh feed. The unburned carbon is col-
lected as a black fluffy particle. The three basic processes for producing this
compound are the furnace process, accounting for about 83 percent of production;
the older channel process, which accounts for about 6 percent of production; and
the thermal process.
Channel Black Process3
In the channel black process, natural gas is burned with a limited air supply
in long, low buildings. The flame from this burning impinges on long steel channel
sections that swing continuously over the flame. Carbon black is deposited on the
5-2 E ISSIO FACTORS 2/72
-------
Table 5-2. EMISSION FACTORS FOR AMMONIA MANUFACTURING WITHOUT CONTROL EQUIPMENT*
EMISSION FACTOR RATING: B
Type of source
Plants with methanator
Purge gasc
Storage and loading0
Plants with CO absorber and
regeneration system
Regenerator exit4'
Purge gasc
Storage and loading1-
Carbon monoxide
Ib/ton
Neg
-
200
Neg
-
kg/MT
Neg
-
TOO
Neg
-
Hydrocarbons'3
Ib/ton
90
-
90
-
kg/MT
45
-
45
-
Ammonia
Ib/ton
3
200
7
3
200
kg/MT
'1.5
100
3.5
1.5
100
References 4 and 5,
Expressed as methane.
Ammonia emissions can be reduced by 99 percent by passing through three stages pf a
packed-tower wattr scrubber. Hydrocarbons are not reduced.
A two-stage water scrubber and incineration system can reduce these emissions to a
negligible amount,
channels, is scraped off, and falls into collecting hoppers. The combustion gases
containing the solid carbon that is not collected on the channels, in addition to car-
bon monoxide and other combustion products, are then vented directly from the
building. Approximately 1 to 1,5 pounds of carbon black is produced from the 32
pounds of carbon available in 1000 cubic feet of natural gas (16 to 24 kilograms,
carbon black from the 513 kilograms in 1000 cubic meters). The balance is
lost as CO, CO2, hydrocarbons, and particulates.
Furnace Process3
The furnace process is subdivided into either the gas or oil process depend-
ing on the primary fuel used to produce the carbon black. In either case, the fuel-
gas in the gas process or gas and oil in the oil process —is injected into a reactor
with a limited supply of combustion air. The combustion gases containing the hot
carbon are then rapidly cooled to a temperature of about 500° F (260° C) by water
sprays and by radiant cooling.
The largest and most important portion of the furnace process consists of the
particulate or carbon black removal equipment. While many combinations of qon-
trol equipment exist, an electrostatic precipitator, a cyclone, and a fabric filter
system, in series are most commonly used to collect the carbon black. Gaseous
emissions of carbon monoxide and hydrocarbons are not controlled in the United
State s.
Thermal Black Process3
In thermal black plants, natural gas is decomposed by heat in the absence of
air or flame. In this cyclic operation, methane is pyrolyzed or decomposed by
passing it over a heated brick checkerwork at a temperature of about 3000° F
(1650° C), The decomposed gas is then cooled and the carbon black removed by a
2/72
Chemical Process Industry
5-3
-------
series of cyclones and fabric filters. The exit gas, consisting largely of hydrogen
(85 percent) , methane (5 percent), and nitrogen, is then either recycled to the1
process burners or used to generate steam in a boiler. Because of the recycling
of the effluent gases, there are essentially no atmospheric emissions from this
process, other than from product handling.
Table 5-3 presents the emission factors from the various carbon black pro-
cesses. Nitrogen oxide emissions are not included but are believed to be low
because of the lack of available oxygen in the reaction.
Table 5-3. EMISSION FACTORS FOR CARBON BLACK MANUFACTURING9
EMISSION FACTOR RATING: C
Type of
process
Channel
Thermal
Furnace
Gas
on
Gas or oil
Participate
Ib/ton
2,300
Neg
c
c
220e
60f
109
kg/MT
1,150
Neg
c
c
noe
3Qf
59
Carbon
monoxide
Ib/ton
33,500
Neg
5,300
4,500
kg/MT .
16,750
Neg
2,650
2,250
Hydrogen
sulfide
Ib/ton
-
Neg
38Sd
kg/MT
-
Neg
19Sd
Hydrocarbons^1
Ib/ton
11,500
Neg
1,800
400
kg/MT
5,750
Neg
900
200
Based on data in References 6, 7, 9, and 10.
As methane.
cParticulate emissions cannot be separated by type of furnace and are listed for
either gas or oil furnaces.
S is the weight percent sulfur in feed.
eOverall collection efficiency was 90 percent with no collection after cyclone.
Overall collection efficiency was 97 percent with cyclones followed by scrubber.
^Overall collection efficiency was 99.5 percent with fabric filter system.
CHARCOAL
Process Descriptions
Charcoal is generally manufactured by means of pyrolysis, or destructive
distillation, of wood waste from members of the deciduous hardwood species. In
this process, the -wood is placed in a retort where it is externally heated for about
20 hours at 500° to 700° F (260° to 370° C). Although the retort has air intakes at
the bottom, these are only used during start-up and thereafter are closed. The
entire distillation cycle takes approximately Z4 hours, the last 4 hours being an
exothermic reaction. Four units of hardwood are required to produce one unit of
charcoal.
5-4
E ISSIO FACTORS
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Emissions and Controls
In the pyrolysis of wood, all the gases, tars, oils, acids, and water are
driven off, leaving virtually pure carbon. All of these except the gas, which cqn-
tains methane, carbon monoxide, carbon dioxide, nitrogen oxides, and aldehydes,
are useful by-products if recovered. Unfortunately, economics has rendered the
recovery of the distillate by-products unprofitable, and they are generally per-
mitted to be discharged to the atmosphere. If a recovery plant is utilized, the igas
is passed through water-cooled condensers. The condensate is then refined while
the remaining cool, non-condensable gas is discharged to the atmosphere. Gaseous
emissions can be controlled by means of an afterburner because the unrecovered
by-products are combustible. If the afterburner operates efficiently, no organic
pollutants should escape into the atmosphere. Emission factors for the manufac-
ture of charcoal are shown in Table 5-4.
Table 5-4. EMISSION FACTORS FOR CHARCOAL MANUFACTURING0
EMISSION FACTOR RATING: C
Pollutant
Participate (tar, oil)
Carbon monoxide
Hydrocarbons0
Crude methanol
Acetic acid
Other gases (HCHQ, Ng, NO)
Type of operation
With chemical
recovery plant
1 b/ton
-
320b
I00b
-
-
60
kg/MT
-
160b
50b
-
-
30
Without chemical
recovery plant
1 b/ton
400
32Qb
IQQb
152
232
60^
kg/MT
200
160b
5Q&
76
116
30b
aCa!cu1ated values based on data in Reference 11,
Emissions are negligible if afterburner is used.
cExpressed as methane.
CHLOR-ALKALI
Process Description12
Chlorine and caustic are produced concurrently by the electrolysis of brine
in either the diaphragm or mercury cell. In the diaphragm cell, hydrogen is
liberated at the cathode and a diaphragm is used to prevent contact of the chlorine
produced at the anode with either the alkali hydroxide formed or the hydrogen. In
the mercury cell, liquid mercury is used as the cathode and forms an amalgam
with the alkali metal. The amalgam is removed from the cell and is allowed to
react with water in a separate chamber, called a denuder, to form the alkali
hydroxide and hydrogen.
Chlorine gas leaving the cells is saturated with water vapor and then cooled
to condense some of the water. The gas is further dried by direct contact with
strong sulfuric acid. The dry chlorine gas is then compressed for in-plant use or
is cooled further by refrigeration to liquefy the chlorine.
2/72
Chemical Process Industry
5-5
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Caustic as produced -in a diaphragm-cell plants leaves the cell as' a dilute
solution along with unreacted brine, ' The solution"is evaporated to increase the
concentration to a range of 50 to 73 percent; evaporation also precipitates most of
the residual salt, which is then removed by filtration, "In mercury-cell plants,
high-purity caustic can be produced in any desired strength and needs no *
concentration.
Emissions and Controls*
Emissions.from, diaphragm- and mercury-cell chlorine plants include
.chlorine gas, carbon dioxide, carbon monoxide, and hydrogen. Gaseous chlorine
is present in the blow.gas from liquefaction, from vents in tank cars and tank con-
tainers during loading and unloading, and from storage tanks and process transfer ._
tanks. Other emissions include mercury vapor frommercury cathode cells and
chlorine from compressor seals, header seals, and the air blowing of depleted
brine in mercury-cell plants.
Chlorine emissions 'from chlor-alkali plants may be controlled by one of three
general methods: (1) use of the gas in other plant processes, (2) neutralization in
alkaline scrubbers, and (3) recovery of chlorine from effluent gas streams. The
effect of specific control practices is shown to some extent in the table on emission
factors (Table 5-5).
Table 5-5, ' EMISSION FACTORS FOR CHLOR-ALKALI PLANTS3
EMISSION FACTOR RATING: B
Type of source
Liquefaction blow gases
Diaphragm cell - uncontrolled
Mercury cell fa - uncontrolled
Water absorber
Caustic or lime scrubber
Loading of chlorine
Tank car vents
Storage tank vents
Air-blowing of mercury-cell brine
Chlorine gas
lb/100 tons
2,000 to 10,000
4,000 to 16,000
25 to 1,000
1
450
1,200
500
kg/ 100 MT
1,000 to 5,000
2,000 to 8,000
12.5 to 500
0,5
225
600
250
References 12 and 13, . . '
Mercury cells lose about 1.5 pounds mercury per 100 tons (0.75 kg/100 MT)
of chlorine liquefied,
EXPLOSIVES
General
An explosive is a material that, under the influence of thermal or mechanical
shock, decomposes rapidly and spontaneously with the evolution of large amounts-
of heat and gas. "* Explosives fall into two major categories: high explosives and
5-6
EMISSION FACTORS
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low explosives. Although a multitude of different types of explosives exists, this
section will deal only with an example of each major category; TNT as the high
explosive and nitrocellulose as the low explosive.
TNT Production15
TNT is usually prepared by a batch three-stage nitration process using '
toluene, nitric acid, and sulfuric acid as raw materials. A combination of nitric
acid and fuming sulfuric acid (oleum) is used as the nitrating agent. Spent acid
from the nitration vessels is fortified with make-up nitric acid before enter ing jthe
next nitrator. The spent acid from the primary nitrator and the fumes from all
the nitrators are sent to the acid-fume recovery system. This system supplies
the make-up nitric acid needed in the process. After nitration, the undesired by-
products are removed from the TNT by agitation with a solution of sodium sulfite
and sodium hydrogen sulfite (Sellite process). The wash waste (commonly called
red water) from this purification process is either discharged directly into a
stream or is concentrated to a slurry and incinerated. The TNT is then solidified,
granulated, and moved to the packing house for shipment or storage. j
Nitrocellulose 15
Nitrocellulose is prepared in the United States by the "mechanical dipper!1
process. This batch process involves dripping the cellulose into a reactor (niter
pot) containing a mixture of concentrated nitric acid and a dehydrating agent such
as sulfuric acid, phosphoric acid, or magnesium nitrate. When nitration is com-
plete, the reaction mixtures are centrifuged to remove most of the spent acid.
The centrifuged nitrocellulose is then "drowned" in water and pumped as a water
slurry to the final purification area.
Emissions
Emissions of sulfur oxides and nitrogen oxides from processes that produce
some of the raw materials for explosives production, such as nitric acid and dul-
furic acid, can be considerable. Because all of the raw materials are not manu-
factured at the explosives plant, it is imperative to obtain detailed process informa-
tion for each plant in order to estimate emissions. The emissions from the manu-
facture of nitric acid and sulfuric acid are not included in this section as they are
discussed in other sections of this publication.
The major emissions from the manufacturing of explosives are nitrogen -
oxides. The nitration reactors for TNT production and the reactor pots and
centrifuges for nitrocellulose represent the largest nitrogen oxide sources.
Sulfuric acid regenerators or concentrators, considered an integral part of the
process, are the major sources of sulfur oxide emissions. Emission factors for
explosives manufacturing are presented in Table 5-6,
HYDROCHLORIC ACID
Hydrochloric acid is manufactured by a number of different chemical pro-
cesses. Approximately 80 percent of the hydrochloric acid, however, is produced
by the by-product hydrogen chloride process, which will be the only process Dis-
cussed in this section. The synthesis process and the Mannheim process are of
secondary importance.
2/72 Chemical Process Industry 5-7
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Table 5-6. EMISSION FACTORS FOR EXPLOSIVES MANUFACTURING WITHOUT CONTROL EQUIPMENT
'.EMISSION FACTOR RATING: C
Type of process
High explosives
TNT
Nitration reactors8
Nitric acid concentrators'5
Sulfuric acid regenerators0
Red water incinerator0^
"Nitric acid manufacture
Low explosives
Nitrocellulose6
Reactor pots
Sulfuric acid concentrators
Particulate " "
Ib/ton
-
0.4
36
-
-
kg'/MT
-
0.2
' 18
Sulfur
oxides ($02)
Ib/ton
-
18
13.
' (See section on
-
-
-
65
kg/MT '
-
9
- 6,5 .
Nitrogen
oxides .'(NOg)
Ib/ton
160.
1
":.- "6 -
kg/MT
-80
0.5
3"
nitric acid)
-
32.5
12
' 29..
6
14.5
With bubble cap absorption, system is 90 to 95 percent efficient.'
References 16 and 17.
cReference 17.
Not employed in manufacture of TNT for commercial use.
Reference 19.
Process Descriptio 20
By-product hydrogen chloride is produced when chlorine is added to .an-organic
compound such as benzene, toluene, and vinyl chloride. Hydrochloric acid is -
produced as a by-product.of this reaction. An example of a process that generates
hydrochloric acid as a by-product is the direct chlorination of benzene. In this .
process benzene, chlorine, hydrogen, air, and some trace catalysts "axe the-raw
materials that produce chlorobenzene. The gases from the reactton-.of benzene and"
chlorine consist of hydrogen chloride, benzene, chlorobenzen.es-,• and air. Tfie:se
gases are first scrubbed in-a packed tower with a .chilled mixture of monochloro- -
benzene and dichlorobenzene to condense .and recover any benzene or chlorobenz-ene.
The hydrogen chloride is then absorbed in a falling film absorption plant.
Emissio s
The recovery of the hydrogen chloride from the chlorination of an-organic
compound is the major source of hydrogen chloride emissions.. _The exit gas from
the absorption or scrubbing system is the actual source of the hydrogen chloride
emitted. Emission factors for hydrochloric acid produced as by-product hydrogen
chloride are presented in Table 5-7. • .
5-8
E ISSIO FACTORS
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Table 5-7, EMISSION FACTORS FOR HYDROCHLORIC ACID MANUFACTURING*
EMISSION FACTOR RATING: B
Typi of process
By-product _ hydrogen chloride
With final scrubber
Uithout final scrubber
Hydrogen chloride emissions
Ib/ton
0.2
3
kg/MT
0,1
1.5
Reference 20.
HYDROFLUORIC ACID
Process Description3
AH hydrofluoric acid in the United States is currently produced by the reac-
tion of acid-grade fluorspar with sulfuric acid for 30 to 60 minutes in externally
fired rotary kilns at a temperature of 400° to 500° F (204° to 260° C). 21~23 Ifhe
resulting gas is then cleaned, cooled, and absorbed in water and weak hydro- '
fluoric acid to form a strong acid solution. Anhydrous hydrofluoric acid is foitmed
by distilling 80 percent hydrofluoric acid and condensing the gaseous HF which is
driven off.
Emissions and Controls3
Air pollutant emissions are minimized by the scrubbing and absorption
systems used to purify and recover the HF. The initial scrubber utilizes concen-
trated sulfuric acid as a scrubbing medium and is designed to remove dust, SO^,
603, sulfuric acid mist, and water vapor present in the gas stream leaving tjie
primary dust collector. The exit gases from the final absorber contain small
amounts of HF, silican tetrsifluoride (S1F4), COz, and SO^ and may be scrubbed
with a caustic solution to reduce emissiqns further. A final water ejector, some-
times used to draw the gasee through the absorption system, will reduce fluoride
emissions. Dust emissions may also result from raw fluorspar grinding and dry-
ing operations. Table 5-8 lists the emission factors for the various operationp.
Table 5-8. EMISSION FACTORS FOR HYDROFLUORIC ACID MANUFACTURING3
EMISSION FACTOR RATING: C
Type of operation
Rotary kiln
Uncontrolled
Water scrubber
Grinding and drying
of fluorspar
Fluorides
Ib/ton acid
5C
0.2
-
kg/MT acid
25
0.1
-
Parti culates
Ib/ton fluorspar
-
20b
kg/MT fluorspar
-
I0b .
References 21 and 24.
Factor given for well-controlled plant.
2/72
Chemical Process Industry
5-9
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NITRIC ACID
Process Description25
The ammonia oxidation process (AOP) is the principal method of producing
commercial nitric acid. It involves high-temperature oxidation of .ammonia .with
air over a platinum catalyst to form nitric oxide. The nitric oxide, air .mixture is
cooled, and additional air is added to complete the oxidation to nitrogen dioxide.
The nitrogen dioxide is absorbed in water to produce an aqneous solution of nitric
acid. The major portion of this 55 to 65 percent HNOj is consumed at this strength,
However, a fairly substantial amount of this -weak acid is concentrated in nitric
acid until it is 95 to 99 percent HNOs; it is then used as the strong acid,
Emissions2 ^
The main source of atmospheric emissions from the manufacture of nitric
acid is the tail gas from the absorption tower, which contains unabsorbed nitrogen
oxides. These oxides are largely in the form of nitric oxide and nitrogen dioxide.
In addition, trace amounts of nitric acid mist are present in the gases as they leave
the absorption system. Small amounts of nitrogen dioxide are also lost from the
acid concentrators and storage tanks. Table 5-9 summarizes the emission factors
for nitric acid manufacturing.
Table 5-9. EMISSION FACTORS FOR NITRIC ACID PLANTS
WITHOUT CONTROL EQUIPMENT
EMISSION FACTOR RATING: B
Type of process
Ammonia - oxidation
Old p!anta'b
New plantc»d
Nitric acid concentrators
Old plantb
New plant0
Nitrogen oxides (N0x)a
Ib/ton
57 -
2 to- 7
5
0.2
kg/MT
28.5
1
2.5
0.1
Catalytic combustors can reduce emissions by 36
to 99.8 percent, with 80 percent the average
control. Alkaline scrubbers can reduce emissions
•by 90 percent.
^Reference 25.
jReference 26.
Reference 65. '
PAINT AND VARNISH
Paint3
The manufacture of paint involves the dispersion of a colored oil or pigment
in a vehicle, usually an oil or resin, followed by the addition of an organic solvent
for viscosity adjustment. Only the physical processes of weighing, mixing, grind-
ing, tinting, thinning, and packaging take place; no chemical reactions are involved.
5-10
E ISSIO FACTORS
2/72
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These processes take place in large mixing tanks at approximately room temperia-
ture. ',
The primary factors affecting emissions from paint manufacture are care in
handling dry pigments, types of solvents used, and mixing temperature, '» ^°
About 1 or 2 percent of the solvents is lost even under we 11-controlled condition^,-
Participate emissions amount to 0.5 to 1, 0 percent of the pigment handled. '
Varnish13
The manufacture of varnish also involves the mixing and blending of various
ingredients to produce a wide range of products. However, in this case chemical
reactions are initiated by heating. Varnish is cooked in either open or enclosed
gas-fired kettles for periods of 4 to 16 hours at temperatures of 200" to 650° F
(93° to 340° C).
Varnish cooking emissions, largely in the form of organic compounds, depend
•on the cooking temperatures and times, the solvent used, the degree of tank enclos-
ure, and the type of air pollution controls used. Emissions from varnish cooking
range from 1 to 6 percent of the raw material.
To reduce hydrocarbons from the manufacture of paint and varnish, control
techniques include condensers and/or adsorbers on solvent-handling operations,-; and
scrubbers and afterburners on cooking operations. Emissions factors for paint •
and varnish are shown in Table 5-10.
Table 5-10. EMISSION FACTORS FOR PAINT AND VARNISH MANUFACTURING
WITHOUT CONTROL EQUIPMENT3»b
EMISSION FACTOR RATING: C '.
Type of
product
Paint
Varnish
Bodying oil
01 eo resinous
Alkyd
Acrylic
Particulate
Ib/ton pigment
2
-
-
-
-
kg/KT pigment
1
-
-
-
-
Hydrocarbons0
Ib/ton of product
30
40
150
160
20
kg/MT pigment
15
20
75
80
10
References 27 and 29 through 33.
Afterburners can reduce gaseous hydrocarbon emissions by 99 percent and particu-
lates by about 90 percent. A water spray and oil filter system can reduce partlcu-
lates by about 90 percent.30
cExpressed as undefined organic compounds whose composition depends upon the type of
varnish or paint.
PHOSPHORIC ACID
Phosphoric acid is produced by two principal methods, the wet process and
the thermal process. The wet process is usually employed when the acid is to be
2/72
Chemical Process Industry
5-11
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used for fertilizer production. Thermal-process acid is normally of higher purity
and is used in the manufacture of high-grade chemical and food products.
Wet Process 34, 35
In the wet process, finely ground phosphate rock is fed into a reactor with
sulfuric acid to form phosphoric acid and gypsum. There is usually little market
value for the gypsum produced, and it is handled as waste material in gypsum
ponds. The phosphoric acid is separated from the gypsum and other insolubles by
vacuum filtration. The acid is then normally concentrated to about 50 to 55 per-
cent P2C>5. When super-phosphoric acid is made, the acid is concentrated to
between 70 and 85 percent P2O5,
Emissions of gaseous fluorides, consisting mostly of silicon tetrafluoride
and hydrogen fluoride, are the major problems from wet-process acid. Table 5-11
summarizes the emission factors from both wet-process acid and thermal-process
acid.
Table 5-11. EMISSION FACTORS FOR PHOSPHORIC ACID PRODUCTION
EMISSION FACTOR RATING: B
Source
Wet process (phosphate rock)
Reactor , uncontrolled
Gypsum pond
Condenser, uncontrolled
Thermal process (phosphorous burnedc)
Packed tower
Venturi scrubber
Glass-fiber mist eliminator
Wire-mesh mist eliminator
High-pressure-drop mist eliminator
Electrostatic precipitator
Particulates
Ib/ton
-
-
-
4.6
5.6
3.0 -
2.7
0.2
1.8
kg/MT
-
-
-
2.. 3
2.8
1.5
1.35
0.1
0.9
Fluorides
Ib/ton
18a
lb
20a
. ,- •
-
-
- .
-
-
kg/MT
ga
l.lb
10a
-
-
-
-
-
-
References 36 and 37.
3Pounds per acre per day (kg per hectare per day); approximately 0.5 acre
(0.213 hectare) is required to produce 1 ton of P20§ daily.
"Reference 38.
Thermal Process34
In the thermal process, phosphate rock, siliceous flux, and coke are heated
in an electric furnace to produce elemental phosphorous. The gaseg containing
the phosphorous vapors are passed through an electrical precipitator to remove
entrained dust. In the "one-step" version of the process, the gases are next
mixed with air to form P£O5 before passing to a, water scrubber to form phosphoric
acid. In the "two-step" version of the process, the phosphorous is condensed and
5-12
E ISSiO FACTORS
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pumped to a tower in which it is burned with air, and the PzOs formed is hydrafed
by a water spray in the lower portion of the tower,
The principal emission from thermal-process acid is PzQs acid mist froiti
the absorber tail gas. Since all plants are equipped with some type of acid-mist
collection system, the emission factors presented in Table 5-11 are based on th'e
listed types of control.
PHTHALIC ANHYDRIDE
Process Description3?, 40
Phthalic anhydride is produced primarily by oxidizing naphthalene vapors
with excess air over a catalyst, usually V2O5- O-xylene can be used instead of
naphthalene, but it is not used as much. Following the oxidation of the naphthalene
vapors, the gas stream is cooled to separate the phthalic vapor from the effluent.
Phthalic anhydride crystallizes directly from this cooling without going throughithe
liquid phase. The phthalic anhydride is then purified by a chemical soak in sulfjurie
acid, caustic, or alkali metal salt, followed by a heat soak. To produce 1 ton of
phthalic anhydride, 2,500 pounds of naphthalene and 830,000 standard cubic feet
(scf) of air are required (or 1,130 kilograms of naphthalene and 23,500 standard!
cubic meters of air to produce 1 MT of phthalic anhydride).
Emissions and Controls 3^
The excess air from the production of phthalic anhydride contains some uncon-
densed phthalic anhydride, maleic anhydride, quinones, and other organics. The
venting of this stream to the atmosphere is the major source of organic emissions.
These emissions can be controlled with catalytic combustion. Table 5-12 presents
emission factor data from phthalic anhydride plants,
Tabli 5-12, EMISSION FACTORS FOR PHTHALIC ANHYDRIDE PLANTS^ '.
EMISSION FACTOR RATING: E
Overall plant
Uncontrolled
Following catalytic combustion
Organics (as hexane)
Ib/ton
32
11
kg/MT
16
5.5
Reference 41.
PLASTICS
Process Description3
The manufacture of most resins or plastics begins with the polymerization or
linking of the basic compound (monomer), usually a gas or liquid, into high molec-
ular weight non-crystalline solids. The manufacture of the basic monomer is not
considered part of the plastics industry and is usually accomplished at a chemical
or petroleum plant.
The manufacture of most plastics involves an enclosed reaction or polymeri-
zation step, a drying step,' and a final treating and forming step. These plastics
2/72 Chemical Process Industry 5-13
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are polymerized or otherwise combined in completely enclosed stainless steel or
glass-lined vessels. Treatment of the resin after polymerization varies with the
proposed use. Resins for moldings are dried and crushed or ground into molding
powder. Resins 'such as the alkyd resins that are to be us«d for protective coatings
are normally transferred to an agitated thinning tank, where they are thinned with
some type of solvent and then stored in large steel tanks equipped with water-
cooled condensers to prevent loss of solvent to' the atmosphere. Still other resins
are stored in latex form as they come from the kettle.
Emissions and Controls3
The major sources of air contamination in plastics manufacturing are "the
emissions of raw materials or monomers, emissions of solvents or other volatile
liquids during the reaction, emissions of sublimed solids such as phthalic anhy-
dride in alkyd production, and emissions of solvents during storage and handling of
thinned resins. Emission factors for the manufacture of plastics are shown in
Table 5-13.
Table 5-13. EMISSION FACTORS FOR PLASTICS MANUFACTURING
WITHOUT CQNTROLSa
EMISSION FACTOR RATING: E
Type of plastic
Polyvinyl chloride
Polypropylene
General
Parti eu late
Ib/ton
35b
3
5 to 10
•kg/MT
17. 5b
1.5
2.5 to 5
Gases
Ib/ton
17C
0.7d
-
kg/MT
ff.SC-
0.35d
-
References 42 and 43. -
Usually controlled with a fabric filter efficiency of 98
to 99 percent. • .
GAs vinyl chloridt.
As propylene.
Much of the control equipment used in this industry is a basic part of the
system and serves to recover a reactant or product. These controls include
floating roof tanks or vapor recovery systems on volatile material, storage units,
vapor recovery systems (adsorption or condensers), purge lines'that vent to a
flare system, and recovery systems on vacuum exhaust lines,1
PRINTING INK
Process Description3
There are four major classes, of printing ink: letterpress and lithographic
inks, commonly called oil or paste ink*; and flexographic and rotogravure inks,"
which are referred to as solvent inks. These inks vary considerably in physical
appearance, composition, method of'application, and drying mechanism. Flexo-
graphic and rotogravure inks have many elements in common with the paste inks
but differ in that they are of very low viscosity,, and they almost always dry by
evaporation of highly volatile solvents. . •• .
.5-14
E ISSIO FACTORS
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There are three general processes in the manufacture of printing inks: (I)
cooking the vehicle and adding dyes, (2) grinding of a pigment into the vehicle using
a roller mill, and (3) replacing water in the wet pigment pulp by an ink vehicle
(commonly known as the flushing process),45 The ink "varnish" or vehicle is gen-
erally cooked in large kettles at 200° to 600° F (93° to 315° C) for an average ,
of 8 to 12 hours in much the same -way that regular varnish is made. Mixing of ^he
pigment and vehicle is done in dough mixers or in large agitated tanks. Grindinjg
is most often carried out in three-roller or five-roller horizontal or vertical mjills.
Emissions and Controls3, 46
Varnish or vehicle preparation by heating is by far the largest source of ink
manufacturing emissions. Cooling the varnish components — resins, drying oil^,
petroleum oils, and solvents— produces odorous emissions. At about 350° F
(175° C) the products begin to decompose, resulting in the emission of decomposi-
tion products from the cooking vessel. Emissions continue throughout the cookijng
process with the maximum rate of emissions occuring just after the maximum
temperature has been reached. Emissions from the cooking phase can be reducied
by more than 90 percent with the use of scrubbers or condensers followed by affler-
burners. J*"> **' ;
Compounds emitted from the cooking of oleoresinous varnish (resin plus
varnish) include water vapor, fatty acids, .glycerine, acrolein, phenols, aldehydes,
ketones, terpene oils, terpenes, and carbon dioxide. Emissions of thinning sol-
vents used in flexographic and rotogravure inks may also occur,
The quantity, composition, and rate of emissions from ink manufacturing |
depend upon the cooking temperature and time, the ingredients, the method of
introducing additives, the degree of stirring, and the extent of air or inert gas ;
blowing. Particulate emissions resulting from the addition of pigments to the
vehicle are affected by the type of pigment and its particle size. Emission factors
for the manufacture of printing ink are presented in Table 5-14.
Table 5-14. EMISSION FACTORS FOR PRINTING INK MANUFACTURINGS
EMISSION FACTOR RATING: E
Type of proctss
Vehicle cooking
General
Oils
Oleoresinous
Al kyds
Pigment mixing
Gaseous organics^
1 b/ton
of product
120
40
150
160
-
kg/MT
of product
60
Parti culates
1 b/ton
of pigment
20 j
75 |
80
-
-
2
kg/MT
of pigment
-
-
-
1
Based on data from section on paint and varnish.
"'Emitted as gas, but rapidly condense as the effluent is cooled.
2/72
Chemical Process Industry
5-15
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SOAP AND DETERGENTS
Soap3
The manufacture of soap entails the catalytic-hydrolysis of various fatty acids '
with sodium or potassium hydroxide to form m glycerol-soap mixture. This mix-
ture is separated by distillation, then neutralized and blended to produce soap, '.
The main atmospheric pollution problem in the manufacture of soap is odor, and,
if a spray drier is used, a particulate emission problem may also occur. Vent
lines, vacuum exhausts, product and raw material, storage, and waste streams are
all potential odor sources. Control of these,odors maybe achieved by scrubbing
all exhaust fumes and, if necessary, incinerating the remaining compounds. Odors
emanating from the spray drier may be controlled by scrubbing with an acid
solution, - ,
Detergents3
The manufacture of detergents generally begins with the sulfuration by sul- .
furic acid of a fatty alcohol or linear alkylate. The sulfurated compound is then
neutralized with caustic solution (NaOH), and various dyes, perfumes, and other
compounds are added. "• "*" The resulting paste or slurry is then sprayed under
pressure into a vertical drying tower where it is dried with a stream of hot air
( 400° to 500° F or 204° to 260° C). The dried detergent is then cooled and pack-
aged. The main source of particulate emissions is the spray-drying tower. Odors
may also be emitted from the spray-drying operation and from storage -and mixing
tanks, Particulate emissions from spray-drying operations are shown inTable 5-15.
Table 5-15. PARTICULATE EMISSION FACTORS FOR SPRAY-DRYING
DETERGENTS^
: EMISSION FACTOR RATING: B ' ;
Control device
None
Cycloneb
Cyclone followed by:
Spray chamber
Packed scrubber
VentuH scrubber
Overall
efficiency, %
_
85
9.2
95
•' - 97 -
Particulate emissions
Ib/ton of
product
90
14
7
5
3
•kg/MT of
product
45
7 '
3.5 .
2.5 -
1.5
Based on-analysis of data in References 48 through 52,
Some type of primary collector, such as a cyclone, is
considered an integral part of the spray-drying system.
SODIUM CARBONATE (Soda Ash)
Process Description3
Soda ash is manufactured by three processes.: (!)• the natural or Lake Brine
process, (2) the Solvay process (ammonia-soda), ..and (3) the electrolytic soda-ash
5-16
E ISSIO FACTORS
2/72
-------
process. Because the Solvay process accounts for over 80 percent of the total ;
production -of soda ash, it will be the only one discussed in this section. !
In the Solvay processs the basic raw materials are ammonia, coke, lime-j
stone (calcium carbonate), and salt (sodium chloride)» The salt, usually in thei
unpurified form of a brine, is first purified in a series of absorbers by precipilfa-
tion of the heavy metal ions with ammonia and carbon dioxide. In this process :
sodium bicarbonate is formed. This bicarbonate coke is heated in a rotary' kilrt,
and the resultant soda ash is cooled and conveyed to storage.
Emissions
The major source of emissions from the manufacture of soda ash is the
release of ammonia. Small amounts of ammonia are emitted in the gases vented
from the brine purification system. Intermittent losses of ammonia can also occur
during the unloading of tank trucks into storage tanks. The major sources of dust
emissions include rotary dryers, dry solids handling, and processing of lime.
Dust emissions of fine soda ash also occur from conveyor transfer points and air
classification systems, as well as during tank-car loading and packaging. Emis-
sion factors are summarized in Table 5-16,
Table 5-16. EMISSION FACTORS FOR SODA-ASH
PLANTS WITHOUT CONTROLS
EMISSION FACTOR RATING: D
Type of source
Ammonia recovery3 "^
Conveying, t«msferrings
loadings etc,c
Participates
Ib/ton
-6
kg/MT
3
Ammonia
Ib/ton
7
kg/MT
3.5
aReference 53.
Represents ammonia loss following the recovery system.
cBased on data in References 54 through 56.
SULFURIC ACID
Process Description57
All sulfuric acid is made by either the chamber or the contact process.
Because the contact process accounts for over 90 percent of the total production of
sulfuric acid in the United States, it will be the only process discussed in this
section. Contact plants may be classified according to the raw materials used:.
(1) elemental sulfur-burning plants, (2) sulfide ore and smelter gas plants, and (3)
spent-acid and hydrogen sulfide burning plants. A separate description of each'
type of plant will be given.
Elemental Sulfur—Bur i g Plants57
Frasch-process or recovered sulfur from oil refineries is melted, settled,
or filtered to remove ash and is then fed into a combustion chamber. The sulfur
2/72
Chemical Process Industry
5-17
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is burned in clean air that has been dried by scrubbing with 93 to 99 percent sul-
fur ic acid. The gases from the combustion chamber are cooled and then enter the
solid catalyst (vanadium pentoxide) converter. Usually, 95 to 98 percent of the
sulfur dioxide from the combustion chamber is converted to sulfur trioxide, with
an accompanying large evolution of heat. The converter exit gas, after being
cooled, enters an absorption tower where the sulfur trioxide is absorbed with 98 to
99 percent sulfuric acid. The sulfur trioxide combines with the water in the acid
and forms more sulfuric acid,
Sulfidc Ore a d Smelter Gas Plants57
Sulfur dioxide gas from smelters is emitted from such equipment as copper
converters, reverberatory furnaces, roasters, and flash smelters. The sulfur
dioxide is contaminated with dust, acid mist, and gaseous impurities. To remove
the impurities the gases must be cooled to essentially atmospheric temperature
and passed through purification equipment consisting of cyclone dust collectors,
electrostatic dust and mist precipitators, and scrubbing and gas-cooling towers,
After the gases are cleaned and the excess water vapor removed, they are scrub-
bed with 66° B6 acid in a drying tower. The remainder of the process is essentially
the same as that in the elemental sulfur plants, • '
Spent—Acid a d Hydrogen Sulfide Burning Plants57
Two methods are used in the processing of this type of sulfuric acid. In one
the sulfur dioxide and other products from the combustion of spent acid and/or
hydrogen sulfide with undried atmospheric air are passed through gas-cooling and
mist-removal equipment. The air stream next passes through a drying tower. A
blower draws the gas from the drying tower and finally discharges the sulfur dioxide
gas to the sulfur trioxide converter.
In a "wet-gas plant, " the wet gases from the combustion chamber ar.e charged
directly to the converter with no intermediate treatment. The gas from the con-
verter then flows to the absorber, through which 60° to 66° Be sulfuric acid is
circulating.
Emissions57
The major source of emissions from contact sulfuric acid plants is waste gas
from the absorber exit stack. The gas discharged to the atmosphere contains pre-
dominantly nitrogen and oxygen, but unreacted sulfur dioxide, unabsorbed sulfur
trioxide, and sulfuric acid mist and spray are also present. When the waste gas
reaches the atmosphere, sulfur trioxide is converted to acid mist. Minor quanti-
ties of sulfur dioxide and sulfur trioxide may come from storage-tank vents, from
tank-truck and tank-car vents during loading operations, from sulfuric acid con-
centrators, and from leaks in process equipment. Emission factors for contact
plants are summarized in Table 5-17.
SYNTHETIC FIBERS
Process Description3
Synthetic fibers are classified into two major categories, semi-synthetic and
"true" synthetic. Semi-synthetics, such as viscose rayon and acetate fibers,
5-18 E ISSIO FACTORS 2/72
-------
Table 5-17. EMISSION FACTORS FOR SULFURIC ACID PLANTS5
EMISSION FACTOR RATING: B
Conversion of S02
to SOs, I
93
94
95
96
97
98
99
99.5
SOg emissions
1b/ ton of 100%
97
84
70
55
40C
26
15
7
kg/MT of 100%
H2S04b
48.5
42
35
27.5
2QC
13
7.5
3.5
Acid-mist emissions range from 0.3 to 7.5 pounds per
ton (0.15 to 3.75 kilograms per metric ton) of acid
produced for plants without acid mist eliminatorss to
0.02 to 0.2 pound per ton (0.01 to 0.1 kilogram per
metric ton) of acid produced for plants with acid-
mist eliminators.
Reference 57.
GUse 40 (20) as an average factor if percent conversion
of
o to SO-s is not known.
result when natural polymeric materials such as cellulose are brought into a dis +
solved or dispersed state and then spun into fine filaments. True synthetic poly-
mers, such as Nylon, * Orion, and Dacron, result from addition and other poly-
merization reactions that form long chain molecules.
True synthetic fibers begin with the preparation of extremely long, chainlike
molecules. The polymer is spun in one of four ways:~*^ (1) melt spinning, in which
molten polymer is pumped through spinneret jets, the polymer solidifying as it
strikes the cool air; (2) dry spinning, in which the polymer is dissolved in a suit-
able organic solvent, and the resulting solution is forced through spinnerets;
(3) wet spinning, in which the solution is coagulated in a chemical as it emerges
from the spinneret; and (4) core spinning, the newest method, in which a continu*
ous filament yarn together with short-length "hard" fibers is introduced onto a
spinning frame in such a way as to form a composite yarn.
Emissions and Controls
In the manufacture of viscose Rayon, carbon disulfide and hydrogen sulfide
are the major gaseous emissions. Air pollution controls are not normally used flo
reduce these emissions, but adsorption in activated carbon at an efficiency of 80
to 95 percent, with subsequent recovery of the CSz, can be accomplished. ^9 Emis-
sions of gaseous hydrocarbons may also occur from the drying of the finished
*Mention of company or product names does not constitute endorsement by the
Environmental Protection Agency,
2/72
Chemical Process Industry
5-119
-------
fiber. Table 5-18 presents emission factors for semi-synthetic and true synthetic
fibers.
Table 5-18. EMISSION FACTORS FOR SYNTHETIC FIBERS MANUFACTURING
EMISSION FACTOR RATING: E
Type of fiber
Semi -synthetic
Viscose rayon9
True synthetic1*
Nylon
Dacron
Hydrocarbons
Ib/ton
7
-
kg/MT
3,5
-
Carbon
disulfide
Ib/ton
55
-
-
kg/MT
27.5
-
-
Hydrogen
sulfide
Ib/ton
6
-
-
kg/MT
3
-
-
Oil vapor
or mist
Ib/ton
15
7
kg/MT
7.5
3.5
Reference 60.
May be reduced by 80 to 95 percent absorption in activated charcoal.
Reference 61.
SYNTHETIC RUBBER
Process Description3
Copolymers of butadiene and styrene, commonly known as SBR account for
more than 70 percent of all synthetic rubber produced in the United States. In a
typical SBR manufacturing process, the monomers of butadiene and styrene are
mixed with additives such as soaps and mercaptans. The mixture is polymerized
to a conversion point of approximately 60 percent. After being mixed with various
ingredients such ae- oil and carbon black, the-latex produet'is coagulated and pre-
cipitated from the latex emulsion. The rubber "particles are then dried and baled.
Emissions and Controls3
Emissions from the synthetic rubber manufacturing process consist of
organic compounds (largely the monomers used) emitted from the reactor and
blow-down tanks, and particulate matter and odors from the drying operations.
Drying operations are frequently controlled with fabric filter systems to
recover any particulate emissions, which represent a product loss. Potential
gaseous emissions are largely controlled by recycling the gas stream back to the
process. Emission factors from synthetic rubber plants'; are summarized in
Table 5-19.
TEREPHTHALIC ACID
Process Description1' °4
The main use of terephthalic acid is to produce dime thy Iterephthalate which
is used for polyester fibers (like Dacron) and films. Terephthalic acid can be
produced in various ways, one of which is the oxidation of paraxylene by nitric
5-20
E ISSIO FACTORS
2/72
-------
Table 5-19. EMISSION FACTORS HJK
SYNTHETIC PLANTS: BUTADIENE-
ACRYLQNITRILE AND BUTADIENE-STYRENE
EMISSION FACTOR RATING: E
Compound
Al kenes
Butadiene
Mithyl propene
Butyne
Pentad iene
Al kanes
Dimethyl heptane
Pentane
Ethanenitrile
Carbonyl s
Acrylonitrile
Aerolein
— ~~~a — b
Emissions '
Ib/ton
40
15
3
1
1
2
1
17
3
kg/MT
20
7.5
1.5
0.5
0.5
1
0.5
8.5
1.5
The butadiene emission is not continuous
and is greatest right after a batch of
partially polymerized latex enters the
blow-down tank.
References 62 and 63.
acid. In this process an oxygen-containing gas (usually air), paraxylene, and
HNO3 are all passed into a reactor where oxidation by the nitric acid takes place
in two steps. The first step yields primarily NzO, while the second step yields
mostly NO in the off gas. The terephthalic acid precipitated from the reactor
effluent is recovered by conventional crystallization, separation, and drying
operations.
Emissions
The NO in the offgas from the reactor is the major air contaminant from the
manufacture of terephthalic acid. The amount of nitrogen oxides emitted is roughly
estimated in Table 5-20.
Table 5-20. NITROGEN OXIDES EMISSION
FACTORS FOR TEREPHTHALIC ACID PLANTS8
EMISSION FACTOR RATING: D
Type of operation
Reactor
Ib/ton
13
kg/MT
6.5
Emissions (NO)
Referenci 64.
2/72
Chemical Process Industry
5-21
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REFERENCES FOR CHAPTER 5
1. Control Techniques for Nitrogen Oxides from Stationary Sources. U.S. DHEW
PHS, EHS, National Aar Pollution Control Administration. Washington, D.'C.
Publication No. AP-67. March 1970. p. 7-12 through 7-13.
2. Goldbeck, M, , Jr. and F, C. Johnson. Process for Separating Adipic Acid
Precursors. E-. I. DuPont de Nemours and Co. U.S. Patent No. 2,703,331.
Official Gazette U.S. Patent Office. 692(1) March 1, 1955.
3. Air Pollutant Emission Factors. Final Report. Resources Research, In-
corporated, 'Reston, Virginia. Prepared for National Air Pollution Control
Administration under .contract no. CPA-22-69-119. April 1970.
4. Burns, W. E, and R. R. McMullan. No Noxious Ammonia Odor Here. Oil •
and Gas'Journal, p. 129-131, February 25, 1967,
5. Axelrod, L. C. andT.E. O'Hare, Production of Synthetic Ammonia. New
York, M, W. Kellogg Company, 1964.
6. Drogin, I. Carbon Black. J. Air Pollution Control Assoc. 18:216-228,
April 1968,
7. Cox, J, T. High Quality, High Yield Carbon Black, Cham, Eng. 57:116-117,
June 1950. ' - ~~
8. Shreve, R. N. Chemical Process Industries. 3rd Ed,. New York," McGraw-
Hill Book Company, 1967. p. 124-130.
9. Reinke, R.A. and T. A. Ruble, Oil Black. Ind. Eng. Chem. 44:685-694,
April 1952,
10. Allan, D, L. The Prevention of Atmospheric Pollution in the Carbon Black
Industry, Chem, Ind. "p. 1320-1324, October 15, 1955.
11. Shreve, R, N. Chemical Process Industries, 3rd'Ed. New York, McGraw-
Hill Book Company, 1967. p. 619.
12. Atmospheric Emissions from Chlor-Alkali Manufacture. U.S. 'EPA, Air
Pollution Control Office. Research Triangle Park, N. C. Publication No.
AP-80, January 1971.
13. Duprey, R, L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Pub-
lication No. 999-AP-42, 1968. p. 49.
14. Shreve, R, N. Chemical Process Industries. 3rd Ed, New York, McGraw-
Hill Book Company, 1967. p. 383-395,
15, Larson, T, and D, Sanchez. Unpublished report on nitrogen oxide emissions
and controls from explosives manufacturing. National Air Pollution Control
- Administration, Office of Criteria and Standards. Durham, N. C,: 1969.
5-22 EMISSION FACTORS 2/72
-------
16. Unpublished data on emissions from explosives manufacturing. National Air
Pollution Control Administration, Federal Facilities Section. Washington,
D. C.
17. Unpublished data on emissions from explosives manufacturing. National Ajir
Pollution Control Administration, Office of Criteria and Standards. Durhaijn,
N. C. June 1970.
18, Control Techniques for Nitrogen Oxides from Stationary Sources. U, S. DHEW,
PHS, EHS, National Air Pollution Control Administration, Washington, D, C.
Publication No. AP-67; March 1970. p. 7-23.
19. Unpublished stack test data from an explosives manufacturing .plant. Army
Environmental Hygiene Agency. Baltimore, Maryland. December 1967,
ZO. Atmospheric Emissions from Hydrochloric Acid Manufacturing Processes.
U.S. DHEW, PHS, CPEHS, National Air Pollution Control Administration.'
Durham, N. C. Publication No. AP-54. September 1969.
21, Rogers, W, E. and K. Muller. Hydrofluoric Acid Manufacture, Chem, Eng.
Progr. 59.:85-88, May 1963,
22. Heller, A.N. , S. T. Cuffe, andD.R. Goodwin. Inorganic Chemical Industry.
In: Air Pollution Engineering Manual. Danielson, J. A. (ed.). U.S. DHEW,
PHS, National Center for Air Pollution Control. Cincinnati, Ohio. Publi-
cation No, 999-AP-40, 1967. p. 197-198.
23. Hydrofluoric Acid. Kirk-Othmer Encyclopedia of Chemical Technology.
9:610-624, 1964.
24. Private Communication between Resources Research, Incorporated, and E.I,
DuPont de Nemours and Company. Wilmington, Delaware, January 13, 1970.
25, Atmospheric Emissions from Nitric Acid Manufacturing Processes. U.S.
DHEW, PHS, Division of Air Pollution. Cincinnati, Ohio. Publication No,
999-AP-27. 1966.
26. Unpublished emission data from a nitric acid plant. U.S. DHEW, PHS, ElfS,
National Air Pollution Control Administration, Office of Criteria and Stan-,
dards. Durham, North Carolina. June 1970,
27. Stenburg, R.L. Atmospheric Emissions from Paint and Varnish Operations.
Paint Yarn. Prod. p. 61-65 and 111-114. September 1959.
28, Private Communication between Resources Research, Incorporated, and
National Paint, Varnish and Lacquer Association. September 1969.
29, Unpublished engineering estimates based on plant visits in Washington, D. C.
Resources Research, Incorporated. Reston, Va. October 1969.
30, Chatfield, H,E. Varnish Cookers. In: Air Pollution Engineering Manual.
Danielson, J. A. (ed. ). U.S. DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio. Publication No. 999-AP-40. 1967. p. 688-695.
2/72 Chemical Process Industry 5-23
-------
31. Lun-che, E.G. et al. Distribution'Survey of Products Emitting Organic
Vapors in Log Angeles County. Chem. Eng. Progr. 53. August"195?,.
32,. Communication on emissions from paint and varnish operations with G,
Sallee, Midwest Research Institute. December 17, 1969,
33. Communication with Roger Higgins, Benjamin Moore Paint Company (June •
25, 1968); As reported in draft report of Control Techniques for. Hydrocarbon
Air Pollutants. . '
34. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C, PHS Pub- -
lication No. 999-AP-42. 1968. p. 16.
35. Atmospheric Emissions trom Wet-Process Phosphoric Acid Manufacture, .
U.S. BHE.W, PHS, EHS, National Air Pollution Control Administration.
'Raleigh, N. C. Publication No. AP-57. April 1970,
36. Atmospheric Emissions from Wet-Process Phosphoric Acid Manufacture, U.S.
DHEW, .PHS, EHS, National Air Pollution Control Administration. Raleigh,-
N. 'C. Publication No. AP-57. April 1970. p. '14, - - ;
37. Control, Techniques for Fluoride Emissions. "Internal document. ."U.S. EPA,
Office of Air Programs, Re search Triangle Park, N.-C. 1970. . • ' •
38." Atmospheric Emissions from Thermal-Process Phospnonc Acid Manufactur-
ing. Cooperative Study Project: Manufacturing Chemists' Association, In-
corporated, and Public Health Service. - U, S. DHEW, PHS, National Ai*- •
Pollution Control Administration. Durham, N. C. Publication No. AP-48.
October 1968.
39. Duprey, "-R.-j_,. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
-PHS, National Center for-Air-Pollution Control. Durham, N. C. PHS Pub-
lication--No. 999-AP-42. 1968, p. 17..'
40. Phthalic Anhydride-. '- Kirk-Othmer Entyclop.edia. of Chemifcml technology, .
2nd ed.'-, • New York, John Wiley and Sons, Inc. ,. 15_:444-485,. 4968.
4-1. ' boicmc, M, J. et al." Systematic Source Test Procedure for tne.-Evaluation
. of Industrial Fume Converters. Presented at 58th Annual Meeting of the
Air Pollution Control Association, Toronto, Canada. June 1965.
42. Unpublished data from industrial questionnaire, U.S. DHEW, PHS, National
Air Pollution Control'Administration, Division of.Air "Quality and Emissions
Data.' 1969. ' '. ' •
43. Private Communication between Resources Research, Incorporated, and
Maryland State Department of-Health. -November 1969.
44. Shreve,. R. N. . Chemical Process Industries. 3rd ed. , New York, McGraw-'
Hill Book Co. , 1967. p. 454-455.
45. -Larsen, "L. M. Industrial Printing Inks. New York, Reinhold Publishing
Company. 1962. ' - .'
5-24 EMISSION FACTORS 2/7:2
-------
46. Chatfield, H.E. Varnish Cookers. In: Air Pollution Engineering Manual.;
Danielson, J. A. {ed,). U. S, DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio, Publication No. 999-AP-40. 196?. p. 688-69P. •
47. Private Communication with Inter chemical Corporation, Ink Division. Cini-
cinnati, Ohio. November 10, 1969. ,
48. Phelps, A, H. Air Pollution Aspects of Soap and Detergent Manufacture.
J. Air Pollution Control Assoc. 17(8):5Q5-507, August 1967.
49.. Shreve, R. N. Chemical Process Industries. 3rd Ed. New York, McGraw-
Hill Book Company, 1967, p. 544-563.
50. Larsen, G. P. , G, I, Fischer, and W. J, Hamming, Evaluating Sources of
Air Pollution, tad, Eng. Chem, 45_:1Q70-1074, May 1953.
51. McCormick, P. Y. , R.L. Lucas, and D. R. Wells, Gas -Solid Systems, In:
Chemical Engineer's Handbook. Perry, J.H. (ed,). New York, McGraw-
Hill Book Company, 1963, p. 59,
52. Private Communication with Maryland State Department of Health. November
1969.
53, Shreve, R. N. Chemical Process Industries. 3rd Ed. New York, McGraw-
Hill Book Company, 1967, p. 2Z5-230.
54. Facts and Figures for the Chemical Process Industries. Chem, Eng. News.
43:51-118, September 6, 1965.
55. Faith, W. L. , D, B. Keyes, and R, L, Clark. Industrial Chemicals, 3rd
ed. , New York, John Wiley and Sons, Inc. 1965.
56. Kaylor, F, B. Air Pollution Abatement Program of a Chemical Processing
Industry. J. Air Pollution Control Assoc. 15_:65-67, February 1965.
57. Atmospheric Emissions from Sulfuric Acid Manufacturing Processes. COH
operative Study Project: Manufacturing Chemists' Association, Incorporated,
and Public Health Service. U.S. DHEW, PHS, Division of Air Pollution.
Washington, D, C. Publication No. 999-AP-13. 1965,
58. Fibers, Man-Made. Kirk-Othmer Encyclopedia of Chemical Technology.
1965.
59. Fluidized Recovery System Nabs Carbon Disulfide. Chem. Eng. 70.(8);92-94,
April 15, 1963.
60, Private Communication between Resources Research, Incorporated, and
Rayon Manufacturing Plant, December 1969,
61. Private Communication between Resources Research, Incorporated, and E.I.
DuPont de Nemours and Company. January 13, 1970.
2/72 Chemical Process Industry i 5-25
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62, The Louisville Air Pollution Study. U.S. DHEW, PHS, Division of Air Pol-
lution, Cincinnati, Ohio. 1961 p. 26-27 and 124.
63, Unpublished data from synthetic rubber plant, U. S, DHEW, PHS, EHS,
National Air Pollution Control Administrationa Division of Air Quality and
Emissions Data. 1969.
64, Terephthalic Acid. Kirk>Othmer Encyclopedia of Chemical Technology. 1964.
65. Control of Air Pollution from Nitric Acid Plants. Internal document. U.S.
Environmental Protection Agency. Durham, N. C, 1971.
5-26 E ISSIO FACTORS 2/72
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6. FOOD AND AGRICULTURAL INDUSTRY
Before food and agricultural products are used by the consumer they under-
go a number of processing steps, such as refining, preservation, and product
improvement, as well as storage and handling, packaging, and shipping. This
section deals with the processing of food and agricultural products and the inter-
mediate steps that present an air pollution problem. Emission factors are pre-
sented for industries where data were available. The primary pollutant emitted
from these processes is particulate matter.
ALFALFA DEHYDRATING
General1'2
An alfalfa dehydrating plant produces an animal feed from alfalfa. The
dehydration and grinding of alfalfa that produces alfalfa meal is a dusty operation
most commonly carried out in rural areas,
"Wet, chopped alfalfa is fed into a direct-fired rotary drier. The dried
alfalfa particles are conveyed to a primary cyclone and sometimes a secondary
cyclone in series to settle out the product from air flow and products of combus-
tion. The settled material is discharged to the grinding equipment, which is
usually a hammer mill. The ground material IB collected in an air-meal separator
and is either conveyed directly to bagging or storage, or blended with other
ingredients.
Emissions and Controls
Sources of dust emissions are the primary cyclone, the grinders, and the ?
air-meal separator. Overall dust losses have been reported as high as 7 percent,
but average losses are around 3 percent by weight of the meal produced. The
use of a baghouse as a secondary collection system can greatly reduce emissions.
Emission factors for alfalfa dehydration are presented in Table 6-1.
Table 6-1. PARTICULATE EMISSION FACTORS
FOR ALFALFA DEHYDRATION3
EMISSION FACTOR RATING: E
Type of operation
Uncontrolled
Baghouse collector
Particulate emissions
Ib/ton of
meal produced
60
3
kg/MT of
meal produced
30
1.5
aReference 3.
2/72 6-1
-------
COFFEE ROASTING
Process Description4' 5
Coffee, which is imported in the form of green "beans, must be cleaned,
blended, roasted, and packaged before being sold. In a typical coffee roasting
operation, the green coffee beans are freed of dust and chaff by dropping the
beans into a current of air. The cleaned beans are then sent to a batch or
continuous roaster. During the roasting, moisture is driven off, the beans swell,
and chemical changes take place that give the roasted beans their typical color
and aroma. When the beans have reached a certain color, they are quenched,
cooled, and stoned.
Emissions '
Dust, chaff, coffee bean oils (as mists), smoke, and odors are the principal
air contaminants emitted from coffee processing. The major source of partieu-
late emissions and practically the only source of aldehydes, nitrogen oxides, and
organic acids is the roasting process. In a direct-fired roaster, gases are vented
without recirculation through the flame. In the indirect-fired roaster, however, a
portion of the roaster gases are recirculated and particulate emissions are
reduced. Emissions of both smoke and odors from the roasters can be almost
4 5
completely removed by a properly designed afterburner. '
Particulate emissions also occur from the stoner and cooler. In the stoner,
contaminating materials heavier than the roasted beans are separated from the
beans by an air stream. In the cooler, quenching the hot roasted beans with water
causes emissions of large quantities of steam and some particulate matter, °
Table 6-2 summarizes emissions from the various operations involved in coffee
processing.
Table 6-2. EMISSION FACTORS FOR ROASTING PROCESSES WITHOUT CONTROLS
EMISSION FACTOR RATING: B
Type of process
Roaster
Direct-fired
Indirect-fired
Stoner and cooler0
Instant coffee spray dryer
Pollutant
Participates3
1 b/ton
7.6
4.2
1.4
1.4d
kg/MT
3.8
2.1
0.7
0.7d
N0xb
1 b/ton
0.1
0.1
_
-
kg/MT
0.05
0.05
-,
-
Aldehydes
1 b/ton
0.2
0.2
_
-
kg/MT
0.1
0.1
-
-
Organic acids^
1 b/ton
0.9
0.9
_
-
kg/MT
0.45
0.45
-
-
Reference 6.
'Reference 4.
"If cyclone is used, emissions can be reduced by 70 percent.
Cyclone plus wet scrubber always used, representing a controlled factor.
6-2
E ISSIO FACTORS
2/72
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COTTON GINNING j
i
General7 >
The primary function of a cotton gin is to take raw seed cotton and separate
the seed and the lint, A large amount of trash is found in the seed cotton, and it
must also "be removed. The problem of collecting and disposing of gin trash fallls
into two main areas. The first consists of collecting the coarse,. heavier traslji
such as burs, sticks, stems, leaves, sand, and dirt. The second problem is j
collecting the finer dust, small leaf particles, and fly lint that are discharged
from the lint after the fibers are removed from the seed. From 1 ton (0. 90? MT)
of seed cotton, approximately one 500-pound (226-kilogram) bale of cotton can be
made,
Emissions and Controls
The major sources of particulates from cotton ginning include the unloading
fan, the cleaner, and the stick and bur machine. From the cleaner and stick and
bur machine, a large percentage of the particles settle out in the plant, and an
attempt has been made in Table 6-3 to present emission factors that take this into
consideration. Where cyclone collectors are used, emissions have been reported
to be about 90 percent less.
Table 6-3. EMISSION FACTORS FOR COTTON GINNING
OPERATIONS WITHOUT CONTROLS9
EMISSION FACTOR RATING: C
Process
Unloading fan
Cleaner
Stick and bur
machine
Miscellaneous
Total
Estimated total
particulates
Ib/bale
5
1
3
3
12
kg/bale
2.27
0.45
1.36
1.36
5.44
Particles >100 y
settled out, 1
0
70
95
50
-
Estimated
emission factor
(released to
atmosphere)
Ib/bale1
5.0
0.30
0.20
1.5
7.0
kg/bale
2.27
0.14
0.09
0.68
3.2
D
References 7 and 8.
One bale weighs 500 pounds (226 kilograms).
FEED AND GRAIN MILLS AND ELEVATORS
General °
Grain elevators are primarily transfer and storage units and are classified
as either the smaller, more numerous country elevators or the larger terminal
elevators. At grain elevator locations the following operations can occur;
2/72
Food and Agriculture Industry
6-3
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receiving, transfer and storage, cleaning, drying, and milling'or grinding. Many
of the large terminal elevators also proce-ss grain at,the same location. The'grain
processing may include wet and dry milling (cereals), flour milling, oil-seed
crushing, and distilling. Feed manufacturing involves the receiving, conditioning
(drying, sizing, cleaning), blending, and pelleting of the grains, and their subse-
quent bagging or bulk loading.
Emissions
Emissions-from .feed and grain operations may be separated into those
occurring at elevators and those occurring at grain processing operations or
feed manufacturing operations. Emission factors for these operations are pre-
sented in Table 6-4. Because dust collection systems are generally applied to
Table 6-4. PARTICULATE EMISSION FACTORS FOR GRAIN HANDLING
AND PROCESSING
FACTOR RATING: B
Type of source
Terminal elevators3
Shipping or receiving
Transferring, conveying, etc.
Screening and cleaning
Drying
Country elevators'3
Shipping or receiving
Transferring, conveying, etc.
Screening and cleaning
Drying
Grain processing
Corn mealc
Soybean processing'5
Barley or wheat cleaner"
Milo cleaner^
Barley flour milling0
Feed manufacturing
Bar! eyf
Emissions
Ib/ton
1
2
5
6
5
3
' . 8
7
5
7
0.26
0.46
3£
36
kg/MT
0.5
1
2.5
3
2.5'
1.5
4
.3.5
2.5
3.5
O.ie
0.2e
1.5e
1.52
References 10 and 11.
Reference 11.
References 11 and 12.
References 13 and 14.
eAt cyclone exit (only non-ether-soluble particulates).
Reference 14.
6-4
EMISSION FACTORS
2/72
-------
most phases of these operations to reduce product and component losses, the !
selection of the final emission factor should take into consideration the overall]
efficiency of these control systems,
Emissions from, grain elevator operations are dependent on the type of .grain,
the moisture content of the grain (usually 10 to 30 percent), the amount of foreign
material in the grain (usually 5 percent or less), the degree of enclosure at lo^td-
ing and "unloading areas, the type of cleaning and conveying, and the amount and
type of control used.
Factors affecting emissions from grain processing operations include th.0
type of processing (-wet or dry), the amount of grain processed, the amount of
cleaning, the degree of drying or heating, the amount of grinding, the temperajture
of the process, and the degree of control applied to the particulates generated^
Factors affecting emissions from feed manufacturing operations include the
type and amount of grain handled, the degree of drying, the amount of liquid
blended into the feed, the type of handling (conveyor or pneumatic), and the degree
of control.
9
FERMENTATION
General Process Description
For the purpose of this report only the fermentation industries associated
with food will be considered. This includes the production of beer, whiskey, and
The manufacturing process for each of these is similar. The four main
brewing production stages and their respective sub-stages are: (1) brewhouse
operations, which include (a) malting of the barley, (b) addition of adjuncts (corn,
grits, and rice) to barley mash, (c) conversion of starch in barley and adjuncts
to maltose sugar by enzymatic processes, (d) separation of wort from grain by
straining, and (e) hopping and boiling of the wort; (2) fermentation, which includes
(a) cooling of the wort, (b) additional yeast cultures, (c) fermentation for 7 to 110
days, (d) removal of settled yeast, and (e) filtaation and carbonation; (e) aging,
•which lasts from 1 to 2 months under refrigeration; and (4) packaging, which >
includes (a) bottling-pasteurization, and (b) racking draft beer.
The major differences between beer production and whiskey production are
the purification and distillation necessary to obtain distilled liquors and the longer
period of aging. The primary difference between wine making and beer making
is that grapes are used as the initial raw.mate rial in wine rather than grains.
Emissions 9
Emissions from fermentation processes are nearly all gases and primarily
consist of carbon dioxide, hydrogen, oxygen, and •water vapor, none of which
present an air pollution problem. However, emissions of particulates can occur
in the handling of the grain for the manufacture of beer and whiskey. Gaseous
hydrocarbons are also emitted from the drying of spent grains and yeast in beier
and from the whiskey-aging warehouses. No significant emissions have been
reported for the production of wine. Emission factors for the various operations
associated with beer, wine, and whiskey production are shown in Table 6-5.
2/72 Food and Agriculture Industry 6-5
-------
Table 6-5. EMISSION FACTORS FOR -FERMENTATION PROCESSES
EMISSION FACTOR RATING: E
Type of product
Beer
Grain handling3
Drying spent grains, etc.*
Whiskey
Grai.n handling3
.Drying spent grains, etc,a
Aging
Wine
Participates
Ib/ton
3
5.
3
5
-
Nege
kg/MT
- 1.5
2.5
1.5
2.5
.
Neg
Hydrocarbons.
Ib/ton
_
NAb
-
NA
10C
Nige
kg/MT
_
NA-
-
NA
0.024d
Neg
b
Based on section on grain processing.
NA: no emission factor available, but emissions do occur.
Pounds per year per barrel of whiskey stored.
Kilograms per year per liter of whiskey stored.
No significant emissions.
FISH PROCESSING
Process Description1^
The canning, dehydration, and smoking of fish, .and the manufacture of fish
Meal and fish oil are the important segments of fish processing. • There are two
types of fish canning operations: the "wet-fish".method, in which the trimmed
fish are cooked.directly in the can, and the "pre-cooked" process, in which the
whole fish is cooked and then hand-sorted before canning. .:
A large fraction of the fish received in a cannery is'procegsed into by-pro- •
ducts, the most important of which is fish meal. In the manufacture of fish meal,
fish scrap from the canning lines is charged to continuous live-steam cookers.
After the material leaves the cooker, it is pressed to remove oil and water. The '
pressed cake is then broken up, usually in a hammer mill,, and dried in a direct-
fired rotary drier or in a steam-tube rotary drier.
Emissions and Controls1
The biggest problem from fish processing is odorous emissions. The prin-
cipal odorous gases gene rated-during the cooking portion of. fish-meal manufactur-'
ing are hydrogen sulfide and trimethylamine. Some of the methods used to control
odors include activated-carbon adsorbers, scrubbing with some -oxidizing solution,
and incineration. The only significant sources of dust emissions in fish processing
are the driers and grinders used to handle, dried fish meal. Emission factors for
fish meal manufacturing are shown in Table 6-6.
6-6
E ISSIO FACTORS
2/72
-------
Table 6-6. EMISSION FACTORS FOR FISH MEAL PROCESSING
EMISSION FACTOR RATING; C .
Emission source
Cookers ,a Ib/ton
(kg/MT) of fish maal
produced
Fresh fish
Stale fish
Driers sb Ib/ton
(kg/MT) of fish scrap
Parti culates
Ib/ton
-
-
0.1
kg/MT
-
-
0.05
Trimethylamine
(CH,)3N
Ib/ton
0.3
3.5
-
kg/MT
0.15
1.75
-
Hydrogen
sulfide (H2S)
Ib/ton
0.01
0.2
-
kg/MT
0.005
0.10
-
Reference 17.
Reference 16.
MEAT SMOKEHOUSES
Process Description
Smoking is a diffusion process in which food products are exposed to an
atmosphere of hardwood smoke, causing various organic compounds to be absorbed
by the food. Smoke is produced commercially in the United States by three major
methods: (1) by burning dampened sawdust (20 to 40 percent moisture), (2) by
burning dry sawdust (5 to 9 percent moisture) continuously, and (3) "by friction.;
Burning dampened sawdust and kiln-dried sawdust are the most widely used
methods. Most large, modern, production meat smokehouses are the recirculi-
ting type, in which smoke is circulated at reasonably high temperatures throughout
the smokehouse.
Emissions and Controls 9
Emissions from smokehouses are generated from the burning hardwood rather
than from the cooked product itself. Baied on approximately 110 pounds of meat
smoked per pound of wood burned (110 kilograms of meat per kilogram of wood
burned), emission factors have been derived for meat smoking and are presented
in Table 6-7.
Emissions from meat smoking are dependent on several factors, including
the type of wood, the type of smoke generator, the moisture content of the wood,
the air supply, and the amount of smoke reclrculated. Both low-voltage electr-
static precipitators and direct-fired afterburners may be used to reduce particmlate
and organic emissions. These controlled emission factors have also been shown in
Table 6-7.
NITRATE FERTILIZERS
General 9. 20
For this report nitrate fertilizers are defined as the product resulting frqrn
the reaction of nitric acid and ammonia to form ammonium nitrate solutions or
2/72
Food and Agriculture Industry
6-7
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Table 6-7. EMISSION FACTORS FOR MEAT SMOKING
EMISSION FACTOR RATING: D
a,b
Pollutant
Parti culates
Carbon monoxide
Hydrocarbons (City)
Aldehydes (HCHO)
Organic acids (acetic)
Uncontrolled
Ib/ton of meat
0.3
0.6
0.07
0.08
0.2
kg/MT of meat
0.15
0.3
0,035
0,04
0.10
Control! edc
Ib/ton of meat
0.1
Negd
Neg
0.05
0.1
kg/MT of meat
0.05
Neg
Neg
0.025
0.05
Based on 110 pounds of meat smoked per pound of wood burned (110 kg meat/kg wood
burned).
References 18, 195 and section on charcoal production.
Controls consist of either a wet collector and low-voltage precipitator in series
or a direct-fired afterburner.
With afterburner.
granules. Essentially three steps are involved in producing ammonium nitrate;
neutralization, evaporation of the neutralized solution, and control of the particle
size and characteristics of the dry product.
Anhydrous ammonia and nitric acid (57 to 65 percent HNO3) ' are brought
together in the neutralizer to produce ammonium nitrate. An evaporator or con-
centrator is then used to increase the ammonium nitrate concentration. The result-
ing solutions may be formed into granules by the use of prilling towers or by
ordinary granulators. Limestone may be added in either process in order to pro-
duce calcium ammonium nitrate, "'
Emissions and Controls
The main emissions from the manufacture of nitrate fertilizers occur in the
neutralization and drying operations. By keeping the neutralization process on the
acidic side, losses of ammonia and nitric oxides are kept at a minimum. Nitrate
dust or particulate matter is produced in the granulation or prilling operation.-
Particulate matter is also produced in the drying, cooling, coating, and material
handling operations. Additional dust may escape from the bagging and shipping
facilities.
Typical operations do not use collection devices on the prilling tower. Wet
or dry cyclones, however, are used for various granulating, drying, or cooling
operations in order to recover valuable products. Table 6-8 presents emission
factors for the manufacture of nitrate fertilizers.
PHOSPHATE FERTILIZERS
Nearly all phosphatic fertilizers are made from naturally occurring phospho-
rous-containing minerals such as phosphate rock. The phosphorous content of
these minerals is not in a form that is readily available to growing plants, so the
minerals must be treated to convert the phosphorous to a plant-available form.
6-8
E ISSIO FACTORS
2/72
-------
Table 6-8. EMISSION FACTORS FOR NITRATE FERTILIZER MANUFACTURING
WITHOUT CONTROLS
EMISSION FACTOR RATING: B
Type of process3
With prilling tower^
Neutralize^'
Prilling tower
Dryers and coolers6
With granul stork
Neutral izer**5
Granulator6
p f
Dryers and coolers "
Particulates
1 b/ton
-
0.9
12
-
0.4
7
kg/MT
-
0.45
6
-
0.2
3.5
Nitrogen
oxides (N03)
1 b/ton
.
-
-
-
0.9
3
kg/MT
-
-
-
-
0.45
1.5
Ammonia
1 b/ton
2
-
-
2
0.5
1.3
kg/MT
1
-
-
1
0.25
0.65
Plants will use either a prilling tower or a granulator but not
both.
Reference 25.
eference 26.
Controlled factor based on 95 percent recovery in recycle scrubber.
l)se of wet cyclones can reduce emissions by 70 percent,
Use of wet-screen scrubber following cyclone can reduce emissions
by 95 to 97 percent.
This conversion can be done either by the process of acidulation. or by a thermal
process. The intermediate steps of the mining of phosphate rock and the manu-
facture of phosphoric acid are not included in this section as they are discussed in
other sections of this publication; it should be kept in mind, however, that large
integrated plants may have all of these operations taking place at one location.
In this section phosphate fertilizers- have been divided into three categories:
(1) normal superphosphate, (2) triple superphosphate, and (3) ammonium phosphate,
Emission factors for the various processes involved are shown in Table 6-9. '
NORMAL SUPERPHOSPHATE
General^?, 28
Normal superphosphate (also called single or ordinary superphosphate) is the
product resulting from the acidulation of phosphate rock with sulphuric acid.
Normal superphosphate contains from 16 to 22 percent phosphoric anhydride (P2O§)«
The physical steps involved in making superphosphate are; (1) mixing rock and
acid, (2) allowing the mix to assume a solid form (denning), and (3) storing (curing)
the material to allow the acidulation reaction to be completed. After the curing
period, the product can be ground and bagged for sale, the cured superphosphate
can be sold directly as run of pile product, or the material can "be granulated lor
sale as granulated superphosphate,
2/72
Food and Agriculture Industry
6-9
-------
Table 6-9. EMISSION FACTORS FOR THE PRODUCTION
OF PHOSPHATE FERTILIZERS
EMISSION FACTOR RATING: C
Type Of product
Normal superphosphate0
Grinding, drying
Main stack
Triple superphosphate0
Run-of-pile (ROP)
Granular
Diammom'um phosphate
Dryer, cooler
Ammoniator-cjranulator
Participates
Ib/ton
9
-
-
-
80
2
kg/MT
4.5
-
-
-
40
1
Fluorides
Ib/ton
-
0.15
0.03
0.10
e
0.04
kg/MT
-
0.075
0,015
0.05
e
0.02
Control efficiencies of 99 percent can be obtained with
fabric filters.
''Total fluorides, including particulate fluorides.
Factors all represent outlet emissions following control
devices, and should be used as typical only in the
absence of specific plant information.
cReferences 30 through 32.
^References 28, 30, and 33 through 36.
Included in ammoniator-granulator total.
Emissions
The gases released from the acidulation of phosphate rock contain silicon
tetrafluoride, carbon dioxide, steam, particuiates, and sulfur oxides. The sulfur
oxide emissions arise from the reaction of phosphate rock and sulfuric acid. ^9
If a granulated superphosphate is produced, the vent gases from the granula-
tor-ammoniator may contain particuiates, ammonia, silicon tetrafluoride, hydro-
fluoric acid, ammonium chloride, and fertilizer dust. Emissions from the final
drying of the granulated product will include gaseous and particulate fluorides,
ammonia, and fertilizer dust.
TRIPLE SUPERPHOSPHATE
General 27, 28
Triple superphosphate (also called double or concentrated superphosphate) is
the product resulting from the reaction between phosphate rock and phosphoric
acid. The product generally contains 44 to 52 percent PZ^BI "which is about three
times the P2Og usually found in normal superphosphates.
Presently, there are three principal methods of manufacturing triple super-
phosphate. One of these uses a cone mixer to produce a pulverized product that is
6-10
E ISSIO FACTORS
2/72
-------
particularly suited to the manufacture of ammoniated fertilizers. This product can
be sold as run of pile (ROP), or it can be granulated. The second method produces
in a multi-step process a granulated product that is well suited for direct applica-
tion as a phosphate fertilizer. The third method combines the features of quick
drying and granulation in a single step,
Emissions
Most triple superphosphate is the nongranular type. The exit gases from a
plant producing the nongranular product will contain considerable quantities of
silicon tetrafluoride, some hydrogen fluoride, and a small amount of particulattes,
Plants of this type also emit fluorides from the curing buildings.
In the cases where ROP triple superphosphate is granulated, one of the great-
est problems is the emission of dust and fumes from the dryer and cooler. Emis-
sions from ROP granulation plants include silicon tetrafluoride, hydrogen fluoride,
ammoniaj particulate matter, and ammonium chloride.
In direct granulation plants, wet scrubbers are usually used to remove the
silicon tetrafluoride and hydrogen fluoride generated from the initial contact
between the phosphoric acid and the dried rock. Screening stations and bagging
stations are a source of fertilizer dust emissions in this type of process.
AMMONIUM PHOSPHATE
General
The two general classes of ammonium phosphates are monoammonium pho-
sphate and diammonium phosphate. The production of these types of phosphate
fertilizers is starting to displace the production of other phosphate fertilizers
because the ammonium phosphates have a higher plant food content and a lower!
shipping cost per unit weight of
There are various processes and process variations in use for manufacturing
ammonium phosphates. In general, phosphoric acid, sulphuric acid, and anhy|drous
ammonia are allowed to react to produce the desired grade of ammonium phosphate.
Potash salts are added, if desired, and the product is granulated, dried, cooled,
screened, and stored,
Emissions
The major pollutants from ammonium phosphate production are fluoride,
particulates, and ammonia. The largest sources of particulate emissions are:the
cage mills, where oversized products from the screens are ground before being
recycled to the ammoniator. Vent gases from the ammoniator tanks are the major
source of ammonia. This gas is usually scrubbed with acid, however, to receiver
the residual ammonia,
STARCH MANUFACTURING
General Process Description37
The basic raw material in the manufacture of starch is dent corn, which con-
tains starch. The starch in the corn is separated from the other components by
"wet milling. "
2/72 Food and Agriculture Industry j 6-11
-------
The shelled grain is prepared for milling in cleaners that remove both the
light chaff and any heavier foreign material. The cleaned corn is then softened by
soaking (steeping) it in warm water acidified with sulfur dioxide. The softened
corn goes through attrition mills that tear the kernels apart, freeing the germ and
loosening the hull. The remaining mixture of starch, gluten, and hulls is finely
ground, and the coarser fiber particles are removed by screening. The mixture
of starch and gluten is then separated by centrifuges, after which the starch is
filtered and washed. At this point it is dried and packaged for market.
Emissions
The manufacture of starch from corn can result in significant dust emissions.
The various cleaning, grinding, and screening operations are the major sources of
dust-emissions. Table 6-10 presents emission factors for starch manufacturing,
Table 6-10. EMISSION FACTORS
FOR STARCH MANUFACTURING9
EMISSION FACTOR RATING: D
Type of operation
Uncontrolled
Controlled13
Particulates
1 h/ ton
8
0.02
kg/MT
4
0.01
aReference 38.
Based, on centrifugal gas scrubber.
SUGAR CANE PROCESSING
General
The processing of .sugar cane starts with the harvesting of the crops, either
by hand or by mechanical means. If mechanical harvesting is used, much of the
unwanted foliage is left, and it thus is standard practice to burn the cane before
mechanical harvesting to remove the greater part of the foliage.
After being harvested, the cane goes through a series of processes to be
converted to the final sugar product. It is washed to remove larger amounts of
dirt and trash, then crushed and shredded to reduce the size of the stalks. The
juice is next extracted by one of two methods, milling or diffusion. 'In milling the
cane is pressed between heavy rollers to press out the juice, and in diffusion the
sugar is leached out by water and thin juices. The raw sugar then goes-through a
series of operations including clarification, evaporation, and crystallization in -
order to produce the final product. . .
Most mills operate without supplemental fuel because of the sufficient bagasse
(the fibrous residue of the extracted cane) that can be burned as fuel.
Emissions
The largest sources of emissions from sugar cane processing are the open-
field burning in the harvesting of the crop and the burning of bagasse as fuel. In
6-12 EMISSION FACTORS 2/72
-------
the various processes of crushing, evaporation, and crystallization, some par-
ticulates are emitted but in relatively small quantities. Emission factors for
sugar cane processing are shown in Table 6-11.
Table 6-11. EMISSION FACTORS FOR SUGAR CANE PROCESSING
EMISSION FACTOR RATING: D
Type of process
Field burning, a»k
Ib/acre burned
kg/hectare burned
Bagasse burning ,c
Ib/ton bagasse
kg/MT bagasse
Particulate
225
250
22
11
Carbon
monoxide
1,500
1,680
-
-
Hydrocarbons
300
335
-
-
Nitrogen
oxides
30
33,5
-
-
Based on emission factors for open burning of agricultural waste.
There are approximately 4 tons/acre (9,000 kg/hectare) of unwanted
foliage on the cane and 11 tons/acre (25,000 kg/hectare) of grass and
weed, all of which are combustible,™
cReference 40.
REFERENCES FOR CHAPTER 6
1. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEJW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42, 1968. p. 19.
Z. Stern, A. (ed.). Air Pollution, Volume III, Sources of Air Pollution and Th^ir •
Control, 2nd. ed. , New York, Academic Press, 1968.
3. Process Flow Sheets and Air Pollution Controls. American Conference of
Governmental Industrial Hygienists, Committee on Air Pollution, Cincinnati,
Ohio. 1961.
4. Polglase, W.L.., H. F. Dey, and R. T. Walsh. Coffee Processing. In: Air,
Pollution Engineering Manual. Danielson, J.A. (ed.). U.S. DHEW, PHS,
National Center for Air Pollution Control. Cincinnati, Ohio. Publication
No. 999-AP-40. 1967. p. 746-749.
5. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42. 1968. p, 19-20.
6. Partee, F. Air Pollution in the Coffee Roasting Industry. Revised ed. U.S.
DHEW, PHS, Division of Air Pollution. Cincinnati, Ohio. Publication No.
999-AP-9. 1966.
7. Air-Borne Particulate Emissions from Cotton Ginning Operations. U. S. •
DHEW, PHS, Taft Sanitary Engineering Center. Cincinnati, Ohio. I960.
2/72
Food and Agriculture Industry
6-13
-------
8. Control and Disposal of Cotton Ginning Waste's, A Symposium Sponsored •
by National Center for Air Pollution Control and Agricultural Research
Service, Dallas, Texas. May 1966. ' . • '\ .
9. Air Pollutant Emission Factors. Final Report. Resources Research, Incor-
porated. Prepared for National Air Pollution "Control Administration under
Contract No. CPA'-22-69*-119, April 1970. Reston, Virginia.
10, Thimsen,- D.J, and P. W. Aften. A Proposed Design for Grain Elevator Dust
Collector. J. Air Pollution Control Assoc. , JL8-(11):738-742I November 1968.
11. Private communication between H. L, Kiser, Grain and Feed'Dealers National
Association, and .-Re source a Research-, Inc. , Washington, D. C. September
1969.' '
12. Contribution of Power Plants and Other Sources to Suspended Particulate and
Sulfur Dioxide .Concentrations in Metropolis, Illinois... U. S DHEW, PHS,
National Air Pollution Control Administration. 1966. - "-'
13. Larson, G. P. , G. I. "Fischer," and W. J, Hamming. Evaluating "Sources .of Air
Pollution. - Ind. Eng. ,Chem. 4S_; 1070-1074, May 1953, •• ' - • .
14. Donnelly,. W. H. Feed and Grain Mills. In: Air Pollution Engineering Manual.
Danielson, J'. A. {ed.). U.S. DHEW, PHS, National Center for Air Pollution
. Control." " Cincinnati, Ohio, Publication No, 999-AF-40. 1967. p. 359.
15, Shreve, R. N. Chemical Process Industries. 3rd. -Ed. New York, McGraw-
Hill Book Company, 1967. p. 591-608, .-.-,-.--
16. Walsh, R. T. , K,D. Luedtke, andL.K, Smith. Fish Canneries and Fish
-Reduction Plants, In: Air Pollution Engineering. Manual, Danielson, J,A, (ed).
U.S.. DHEW, PHS, National Center for Air Pollution Control. Cincinnati,
Ohio. Publication No. 999-AP-40. 1967. p. 760-770.
17, Summer, W. Methods of Air Deodorization/ New York, Elsvier Publishing.
" Company, p. 284-286.- ... .
18. Carter, E. Private communication, between Maryland State Department of
Health and Resources Research, Incorporated. .November 21, 1969. •
19. Polglase, W..L. , H. F, Dey, and R. T. Walsh.- Smokehouses. In; Aii"Pollu-'
tion Engineering Manual, Danielson,' J. A. (ed). U.. S. DHEW,. PHS, National .
.Center for Air Pollution Control. Cincinnati, Ohio. Publication No. 999-AP-
40., 1967. p. 750-755. ' " , -
20. -Stern,; A. (ed.). Air Pollution, Vulume III, Sources of Air Pollution-and
Their Control, 2nd ed. , New York, Academic Press, 1968. p. 231-234.
21. Sauchelli, V, Chemistry and Technology of Fertilizers. New York, Reinhol.d
Publishing Company, I960. " - :- " '..
22. Falck-Muus, R. New Process Solves Nitrate Corrosion. Chem. Eiig.'
24(14): 108, JulyS, 1967.
6-14 E 1SSIO FACTORS 2/72
-------
23. EUwood, P, Nitrogen Fertilizer Plant Integrates Dutch and American Know-
How. Chem. Eng. May 11, 1964, p, 136-138.
24, Ghemico, Ammonium Nitrate Process Information Sheets.
25. Unpublished Source Sampling Data. Resources Research, Incorporated.
Reston, Virginia,
26. Private Communication with personnel from Gulf Design Corporation.
Lakeland, Florida.
27. Bixby, D, W. Phosphatic Fertilizer's Properties and Processes. The
Sulphur Institute. Washington, D. C. October 1966.
28. Stearn, A, (ed.). Air Pollution, Volume III, Sources of Air Pollution and
Their Control, 2nd ed., New York, Academic Press, 1968. p. 231-234.
29. Sherwin, K. A. Transcript of Institute of Chemical Engineers, London. •
32:172, 1954.
30. Unpublished Data on Phosphate Fertilizer Plants. U.S. DHEW, PHS,
National Air Pollution Control Administration, Division of Abatement, Engi-
neering Branch. July 1970.
31. Jacob, K.O., H. L. Marshall, D.S. Reynolds, andT.H, Tremearne. Com-
position and Properties of Superphosphate, Ind. Eng. Ghent. ^4_(6): 722-728,
June 1942.
32. Slack, A, V, Phosphoric Acid. Volume 1, Part II. New York, Marcel Dpkker,
Incorporated, 1968, p. 732.
33. Teller, A. J, Control of Gaseous Fluoride Emissions. Chem. Eng. Progr.
63j3):75-79» March 1967,
34, Slacks A. V. Phosphatic Acid, Volume 1, Part II. New York, Marcel Dekker,
Incorporated, 1968. p. 722.
35. Slack, A. V, Phosphoric Acid. Volume 1, Part II. New York, Marcel Dekker,
Incorporated. 1968. p. 760-762,
36, Salee, G. Unpublished data from industrial source. Midwest Research
Institute. June 1970.
37. Starch Manufacturing. Kirk-Othmer Encyclopedia of Chemical Technology.
1964.
38. Storch, H. L. Product Losses Cut with a Centrifugal Gas Scrubber. Chem.
Eng, Progr. 62_:51-54. April 1966,
39. Sugar Cane. Kirk-Othmer Encyclopedia of Chemical Technology. 1964.
40. Cooper, J, Unpublished data on emissions from the sugar cane industry.
Air Pollution Control Agency, Palm Beach County, Florida, July 1969.
2/72 Food and Agriculture Industry 6-15
-------
-------
7. METALLURGICAL INDUSTRY
The metallurgical industries can be broadly divided into primary and second-
ary metal production operations. The term primary metals refers to production
of the metal from ore. The secondary metals industry includes the recovery of
metal from scrap and salvage and the production of alloys from ingot.
The primary metals industries discussed in this section include the non-
ferrous operations of aluminum ore reduction, copper smelters, lead smelters,
and zinc smelters. These industries are characterized by the large quantities of
sulfur oxides and particulates emitted. The primary metals industry also includes
iron and steel mills, ferroalloy production, and metallurgical coke manufacture.
The secondary metallurgical industries discussed in this section are alumi-
num operations, brass and bronze ingots, gray iron foundries, lead smelting,
magnesium smelting, steel foundries, and zinc processing. The major air con-
taminants from these operations are particulates in the forms of metallic fumes,
smoke, and dust,
PRIMARY METALS INDUSTRY
Aluminum Ore Reduction
Process Description - Bauxite, a hydrated oxide of aluminum associated with
silicon, titanium, and iron, is the base ore for aluminum production. Most bauxite
ore is purified by the Bayer process in which the ore is dried, ground in ball mills,
and mixed with sodium hydroxide. Iron oxide, silica, and other impurities are
removed by settling, dilution, and filtration. Aluminum hydroxide is precipitated
from the diluted, cooled solution and calcined to produce pure alumina,
The recovery of the aluminum from the purified oxide is accomplished by an
electrolytic process, called the Hall-Herout process, in which alumina is dis-
solved in a fused mixture of fluoride salts and then reduced to metallic aluminum
and oxygen. This takes place in an electrolytic cell commonly known as a pot.
Three types of cells are in common use: the Prebake, the Horizontal Stud Soder-
berg, and the Vertical Stud Soderberg. In the Prebake, the carbon anodes are
baked before mounting in the cells. In the Soderberg cells, the carbon post is
added continuously and baked by the heat of the bath. The position of the metal
studs, •with respect to the anode, can either be horizontal or vertical. Four unit
weights of bauxite are required to make 2 unit weights of alumina, which yields
1 unit weight of metallic aluminum. To produce 1 ton of aluminum, 16, 000 kW-hr
of electricity is required (18, 000 kW-hr is required to produce 1 MT. )
Emissions - During the pot reduction process, the effluent released contains some
fluoride particulates and some gaseous hydrogen fluoride. Particulate matter such
as alumina and carbon from the anodes are also emitted. The calcining of alumi-
num hydroxide for the production of alumina generates vast amounts of dust.
Because of the value of this dust, however, extensive controls are employed that
2/72 7-1
-------
reduce these emissions to an insignificant amount. Table 7-1 summarizes emission
factors for aluminum production.
Table 7-1. EMISSION FACTORS FOR ALUMINUM ORE
REDUCTION WITHOUT CONTROLS3
EMISSION FACTOR RATING: B
Type of operation
Electrolytic cells
Prebake
Horizontal stud
soderberg
Vertical stud
soderberg
Calcining aluminum
hydroxide^e
Parti culates
Ib/ton
55
140
80
20
kg/MT
27.5
70
40
10
Fluorides0
Ib/ton
80
80
80
•-
kg/MT
40
40
40
-
Emission factors expressed as units per unit weight
of aluminum produced.
References 4 and 5.
Reference 6.
Reference 1.
Represents controlled factor since all calcining
units are controlled to remove the valuable dust.
Metallurgical Coke Manufacturing
Proces s Description - Coking is the process of heating coal in an atmosphere of
low oxygen content, i.e., , destructive distillation. During this process organic
compounds in the coal break down to yield gases and a residue of relatively non-
volatile nature. Two processes are used for the manufacture of metallurgical
coke, the beehive process and the by-product process; the by-procuct process
accounts for more than 98 percent of the coke produced.
Beehive oven: The beehive is a refractory-lined enclosure with a dome-
shaped roof. The coal charge is deposited onto the floor of the beehive and leveled
to give a uniform depth of material. Openings to the beehive oven are then
restricted to control the amount of air reaching the coal. The carbonization pro-
cess begins in the coal at the top of the pile and works down through it. The
volatile matter being distilled escapes to the atmosphere through a hole in the
roof. At the completion of the coking time, the coke is "watered out" or quenched.
7
By-product process: The by-product process is oriented toward the
recovery of the gases produced during the coking cycle. The rectangular coking
ovens are grouped together in a series alternately interspersed with heating flues
called a coke battery. Coal is charged to the ovens through ports in the top,
which are then sealed. Heat is supplied to the ovens by burning some of the coke gas
produced. Coking is largely accomplished at temperatures of 2000° to 2100° F
(1100° to 1150° C) for a period of about 16 to 20 hours. At the end of the coking
period, the coke is pushed from the oven by a ram and quenched with water.
7-2
EMISSION FACTORS
2/72
-------
EmisjLJons. ~ Visible smoke, hydrocarbons, carbon monoxide, and other emissions
originate from the following by-product coking operations: (1) charging of the cpal
into the incandescent ovens, (2) oven leakage during the coking period, (3) pushing
the coke out of the ovens, and (4) quenching the hot coke. Virtually no attempts
have been made to prevent gaseous emissions from beehive ovens. Gaseous
emissions from the by-product ovens are drawn off to a collection main and are
subjected to various operations for separating ammonia, coke-oven gas, tar,
phenol, light oil (benaene, toluene, xylene), and pyridine. These xmit operationg
are potential sources of hydrocarbon emissions.
Oven-charging operations and leakage around poorly sealed coke-oven doors
and lids are major sources of gaseous emissions from by-product ovens. Sulfur
is present in the coke-oven gas in the form of hydrogen sulfide and carbon disul-
fide. If the gas is not desulfurized, the combustion process will emit sulfur
dioxide.
Associated with both coking processes are the material-handling operations
of unloading coal, storing coal, grinding and sizing of coal, screening and crush-
ing coke, and storing and loading coke. All of these operations are potential par-
ticulate emission sources. In addition, the operations of oven charging, coke
pushing, and quenching produce particulate emissions. The emission factors for
coking operations are summarized in Table 7-2.
Copper Smelters
Process Description ' - Copper is produced primarily from low-grade sulfide
ores, which are concentrated by gravity and flotation methods. Copper is
recovered from the concentrate by four steps: roasting, smelting, converting,
and refining. Copper sulfide concentrates are normally roasted in either multiple-
hearth or fluidized bed roasters to remove the sulfur and then calcined in prepara-
tion for smelting in a reverberatory furnace. For about half the smelters the
roasting step is eliminated. Smelting removes other impurities as a slag with the
aid of fluxes. The matter that results from smelting is blown with air to remoye
the sulfur as sulfur dioxide, and the end product is a crude metallic copper. A
refining process further purifies the metal by insertion of green logs or natural
gas. This is often followed by electrolytic refining.
Emissions and Controls - The high temperatures attained in roasting, smelting,
and converting cause volatilization of a number of the trace elements present im
copper ores and concentrates. The raw waste gases from these processes contain
not only these fumes but also dust and sulfur oxide. Carbon monoxide and nitrogen
oxides may also be emitted, but no quantitative data have been reported in the
literature.
The value of the volatilized elements dictates efficient collection of fumes and
dusts. A combination of cyclones and electrostatic precipitators seems to be most
often used. Table 7-3 summarizes the uncontrolled emissions of particulates and
sulfur oxides from copper smelters.
Ferroalloy Production
Process Description
iron and one or more other metals. Ferroalloys are used in steel production
Process Description ' - Ferroalloy is the generic term for alloys consisting of
2/72 Metallurgical Industry 7-3
-------
-TI
3>
O
o
20
Table 7-2. FOR METALLURGICAL COKE WITHOUT CONTROLS"
EMISSION FACTOR RATING: C
Type of operation
By-product coking^
Unloading
Charging
Coking cycle
Discharging
Quenching
Underfiringf
Beehive ovens6
Partieulates
Ib/ton
0.4
1.5
0.1
0,6
0.9
200
kg/MT
0.2
0.75
0.05
0.3
0.45
100
Sulfur
dioxide
Ib/ton
-
0.02
• -
-
10
-
kg/MT
-
0.01
-
-
5
-
Carbon
monoxide
Ib/ton
-
0.6
0.6
0.07
•*
1
kg/MT
-
0.3
0.3
0.035
~
0.5
Hydrocarbons
Ib/ton
-
2.5
1.5
0.2
—
8
kg/MT
-
1.25
0.75
0.1
—
4
Nitrogen
oxides c
Ib/ton
-
0.03
0.01
-
—
-
kg/MT
-
0.015
0.005
_
-
-
Ammonia
Ib/ton
-
0.02
0.06
0.1
—
2
kg/MT
-
0.01
0.03
0.05
"•
1
Emission factors expressed as units per unit weight of coal charged.
""Expressed as methane.
:N02.
References 8 and 9.
^References 7 and 10.
Reference 11. Use a factor of 4 Ib/ton (2 kg/MT) of coal for underfiring when coke-oven gas is desulfurized
before use in other areas of the process.
-xl
IS3
-------
Table 7-3. EMISSION FACTORS FOR PRIMARY COPPER SMELTERS
WITHOUT CONTROLS3
EMISSION FACTOR RATING: C
Type of operation
Roasting
Smelting (reverberatory
furnace)
Converting
Refining
Total uncontrolled
Partieulatesb»c
Ib/ton
45
20
60
10
135
kg/MT
22.5
10
30
5
67.5
Sulfur
oxides^
Ib/ton
60
320
870
-
1,250
kg/MT
30
160
435
-
625
Approximately 4 unit weights of concentrate are required
to produce 1 unit weight of copper metal'. Emission *
factors expressed as units per unit weight of concen-
trated ore produced.
bReferences 10, 13, and 14.
Electrostatic precipitators have been reported to reduce
emissions by 99.7 percent.
Sulfur oxides can be reduced by about 90 percent by using
a combination of sulfuric acid plants and lime slurry
scrubbing.
alloying elements and deoxidants. There are three basic types of ferroalloys: .
(1) silicon-based alloys, including ferrosilicon and calciumsilicon; (2) manganese-
based alloys, including ferromanganese and gilicomanganese; and (3) chromiurni-
based alloys, including ferrochromiurn and ferrosilieochrome,
The four major methods used to produce ferroalloy and high-purity metallic
additives for steelmaking are: (1) blast furnace, (2) electrolytic deposition, (3)
alumina silico-thermic process, and (4) electric smelting furnace. Because ovier
75 percent of the ferroalloys are produced in electric smelting furnaces, this
section deals only with that type of furnace.
The oldest, simplest, and most widely used electric furnaces are the sub4
mergcd-arc open type, although semi-covered furnaces are also used. The alloys
are made in the electric furnaces by reduction of suitable oxides. For example,
in making ferrochromiurn the charge may consist of chrome ore, limestone,
quartz (silica), coal, and wood chips, along with scrap iron.
Emissions - The production of ferroalloys has many dust- or fume-producing
steps. The dust resulting from raw material handling, mix delivery, and crushing
and sizing of the solidified product can be handled by conventional techniques and
is ordinarily not a pollution problem. By far the major pollution problem arises
from the ferroalloy furnaces themselves. The conventional submerged-arc
furnace utilizes carbon reduction of metallic oxides and continuously produces
large quantities of carbon monoxide. This escaping gas carries large quantities
of particulates of submicron size, making control difficult.
2/72
Metallurgical industry
7-5
-------
In an open furnace essentially all of the carbon monoxide burns with induced
air at the top of the charge, and CO emissions are small. Partieulate-emissions
from the open "furnace, however, can be quite large. In the semi-closed furnace,
most or all. of the CO is withdrawn from the furnace and burns with dilution air
introduced into the system. The uriburned CO goes through particul.ate control =
devices and'can be used as boiler fuel or can be flared directly. Particulate
emission factors for electric smelting furnaces are.presented in Table 7-4. No
carbon monoxide emission data'have been reported in the literature.
Table 7-4. EMISSION FACTORS FOR FERROALLOY
' PRODUCTION IN ELECTRIC SMELTING FURNACES8
EMISSION FACTOR RATING; C
Type of furnace and
product
Open furnace
B0% FeSib
. 75% FeSic
: 9Q% FeSib
Silicon metal °
Silicomanganese6
Semi -covered furnace
Ferromanganese6
Particulates
Ib/ton
200
315
'• 565
625
195
45
- kg/MT
100
157.5
282.5
312.5
97.5
22.5
Emission factors expressed as units per unit
hweight of specified product produced.
"Reference 17.
^References 18 and 19.
^•References 17 and 20.
Reference 19.
Iron and Steel Mills
General - To make steel, iron ore is reduced to pig iron, and some of its impuri-
ties are removed in a blast furnace. The pig iron is further purified .-in open
hearths, basic oxygen furnaces, or electric'furnaces. Other operations) including
the production of by-product coke and sintering, are not discussed in much detail
in this section as they .are covered in other sections.of this publication. -;
Blast Furnace - The blast furnace is a large refractory—lined chamber into which
iron ore, coke, and limestone are charged and allowed to react with large amounts
of hot air to produce molten iron. Slag .and blast-furnace gases are by-products
.from this reaction. To produce 1 unit "weight of pig-iron requires,- on the average,
1, 5 unit weights of iron-bearing charge; 0. 6 unit weight of coke; 0. 2 unit weight of
limestone; 0. 2 unit weight of cinder, scale, and scrap; and 2, 5 unit weights of air.
Most of the coke used in the blast-furnaces is produced by "by-product" coke .ovens.
Sintering plants are used to convert iron ore fines and blast-furnace flue .dust into
products more suitable for "charging to the blast furnace.
7-6
E 1SS10 FACTORS
2/72
-------
As blast-furnace gas leaves the top of the furnace, it contains large amoujnts
of particulate matter. This dust contains about 30 percent iron, 15 percent caribon,
10 percent silicon dioxide, and small amounts of aluminum oxide, manganese
oxide, calcium oxide, and other materials. Blast-furnace gas-cleaning systenqis,
composed of settling chambers, low-efficiency wet scrubbers, and high-efficiency
wet scrubbers or electrostatic precipitators connected in series, are used to
reduce particulate emissions. All of the carbon monoxide generated in the blagt
furnace is normally used for fuel. However, abnormal conditions such as "slijjts"
can cause instantaneous emissions of carbon monoxide. The improvements in
techniques for handling blast furnace burden have made slips occur infrequently.
Open-Hearth Furnace ' - In the open-hearth process for making steel, a mix-
ture of scrap iron, steel, and pig iron is melted in a shallow rectangular basin^
or "hearth, " in which various liquid or gaseous fuels provide the heat. Impurities
are removed in a slag. Oxygen injection (lancing) into the furnace speeds the
refining process, saves fuel, and increases steel production.
The fumes from open-hearth furnaces consist predominantly of iron oxides.
Oxygen lancing increases the amount of fume and dust produced. Control of irc^n
oxide requires high-efficiency collection equipment such as venturi scrubbers and
electrostatic precipitators.
Basic Oxygen Furnaces - The basic oxygen process, called the Linz-Donawitz
or LD process, is employed to produce steel from hot blast-furnace metal and
some added scrap metal by use of a stream of commercially pure oxygen to oxidize
the impurities, principally carbon and silicon.
The reaction that converts the crude molten iron into steel generates a cqn-
siderable amount of particulate matter, largely in the form of oxide. Carbon
monoxide is also generated in this process but is emitted only in small amounts
after ignition of the gases above the furnace. Electrostatic precipitators, high|-
energy venturi scrubbers, and baghouse systems have been used to control dus£
emissions.
T 1 TO
Electric Arc Furnaces - Electric furnaces are used primarily to produce
special alloy steels or to melt large amounts of scrap for reuse. Heat is furnished
by direct-arc-type electrodes extending through the roof of the furnace. In recent
years, oxygen has been used to increase the rate of uniformity of scrap melt-down
and to decrease power consumption.
The dust that occurs when steel is being processed in an electric furnace
results from the exposure of molten steel to extremely high temperatures. The
excess carbon added to stir and purge the metal when oxidized creates a source of
carbon monoxide emissions. For electric furnaces, venturi scrubbers and electro-
static precipitators are the most widely used control devices.
Scarfing ' - Scarfing is a method of surface preparation of semi-finished steel.
A scarfing machine removes surface defects from the steel billets and slabs before
they are shaped or rolled by applying jets of oxygen to the surface of the steel,
which is at orange heat, thus removing a thin upper layer of the metal by rapid
oxidation.
2/72 Metallurgical Industry 7-7
-------
The scarfing process generates an iron oxide fume. The rate of emissions
is affected by the steel analysis and amount of metal removal required.'
Table 7-5 summarizes emission factors for the production of iron ore and
steel and the associated operations.
Lead Smelters
27 28
Process^ De B cr iption * - The ore from which primary lead is produced-contains
both lead and zinc. Thus, both lead and zinc concentrates are made by concen-
tration and flotation from the ore. The lead concentrate is usually roasted .in
traveling-grate sintering machiness thereby removing sulfur and forming lead
oxide. The lead oxide, sinter, coke, and flux (usually limestone) are fed to the
blast furnace, in which oxide is reduced to metallic lead. The lead may be further
refined by a variety of other processes, usually including a brass reverberatory
furnace.
Emissions and Controls - Effluent gases from the roasting, sintering, and smelting
operations contain considerable particulate matter and sulfur dioxide. Dust and
fumes are recovered from the gas stream by settling in large flues and by precip-
itation in Cottrell treaters or filtration in large baghouses. The emission factors
for lead smelting are summarized in Table 7-6, The effect of controls has been
shown in the footnotes of this table.
Zinc Smelters
Process Description'' '» - As stated previously, most domestic zinc comes from
zinc and lead ores. Another important source of raw material for zinc metal has
been zinc oxide from fuming furnaces. For efficient recovery of zinc, sulfur must
be removed from concentrates to a level of less than 2 percent. This is done by
fluidized beds or multiple-hearth roasting occasionally followed by sintering.
Metallic zinc can be produced from the roasted ore by the horizontal or vertical
retort process or by the electrolytic process if a high-purity zinc is needed.
Emissions and Controls "' - Dust, fumes, and sulfur dioxide are emitted from
zinc concentrate roasting or sintering operations. Particulates may be removed
by electrostatic precipitators or baghouses. Sulfur dioxide may be converted
directly into sulfuric acid or vented. Emission factors for zinc smelting are pre-
sented in Table 7-7,
SECONDARY METALS INDUSTRY
Aluminum Operations
Process Description ' - Secondary aluminum operations involve making light-
weight metal alloys for industrial castings and ingots. Copper, magnesium, and
silicon are the most common alloying constituents. Aluminum alloys for castings
are melted in small crucible furnaces charged by hand with pigs and foundry
returns. Larger melting operations use open-hearth reverberatory furnaces
charged with the same type of materials but by mechanical means. Small operators
sometimes use sweating furnaces to treat dirty scrap in preparation for smelting.
7-8 E ISS10 FACTORS 2/72
-------
Table 7-5. EMISSION FACTORS FOR IRON AND STEEL MILLS WITHOUT CONTROLS
EMISSION FACTOR RATING: A
Type of operation
Iron production
Blast furnaceb.c
Ore charge
Agglomerates charge
Coke ovens
Sintering6
Uindboxf>9
Discharge"
Steel production
Open-hearth furnace0 «J
Oxygen lance
No oxygen lance
Basic oxygen furnacec>k
Electric-arc furnacecsm
Oxygen lance
No oxygen lance
Scarfing6
Particulates
Ib/ton
110
40
kg/MT
55
20
._ — • • i-—
Carbon monoxide3
Ib/ton
1,400 to 2,100d
-
kg/MT
700 to l,050d
-
(see section on Metallurgical Coke)
20
22
22
12
46
11
7
20
10
11
11
6
23
5.5
3.5
10
_
44i
~
22 i
-
-
120 to 1501
13
18
-
-
60 to 751
9
9
-
Reference 23.Emission factors expressed as units per unit weight of metal produced.
Preliminary cleaner (settling chamber or dry cyclone) collection efficiency =
60 percent. Primary cleaner (wet scrubber in series with preliminary cleaner)
collection efficiency = 90 percent. Secondary cleaner (electrostatic precipita-
tor or venturi scrubber in series with primary cleaner) collection efficiency =
90 percent.
Reference 25.
Represents the amount of CO generated; normally all of the CO generated is used
for fuel. Abnormal conditions may cause the emission of CO.
References 24 and 26.
Dry-cyclone collection efficiency = 90 percent. Electrostatic precipitator (in
series with dry-cyclone) collection efficiency = 95 percent.
9About 3 pounds S02 per ton (1.5 kg/MT) of sinter is produced at windbox.
Dry-cyclone collection efficiency = 93 percent.
Pounds per ton (kg per MT) of finished sinter.
^Electrostatic precipitator collection efficiency = 98 percent. Venturi scrubber
collection efficiency = 85 to 98 percent. Baghouse collection efficiency =
99 percent.
k
Venturi scrubber collection efficiency = 99 percent. Electrostatic precipitator
collection efficiency = 99 percent.
Represents generated CO. After ignition of the gas above the furnace, the CO
amounts to 0 to 3 Ib/ton (0 to 1.5 kg/MT) of steel produced.
High-efficiency scrubber collection efficiency = up to 98 percent. Electrostatic
precipitator collection efficiency = 92 to 97 percent. Baghouse collection
efficiency = 93 to 99 percent.
2/72
Metallurgical Industry
7-9
-------
Table 7-6. EMISSION FACTORS FOR PRIMARY LEAD SMELTERS3
EMISSION FACTOR RATING: B
lype of operation
Sintering and sintering
crushing0
Blast furnace6
Reverberatory furnace6
Particulates'3
Ib/ton
50d
75
12
kg/MT
25d
.37.5
6
Sulfur oxides
Ib/ton
660
f
f
kg/MT
330
f
f
Approximately 2 unit weights of concentrated ore are
required to produce 1 unit weight of lead metal.
Emission factors expressed as units per unit weight
.of concentrated ore produced.
Electrostatic precipitator collection efficiency =
96 percent. Baghouse collection efficiency = 99.5
percent.
^References 14 and 28.
Pounds per ton (kg/MT) of sinter.
..Reference 10.
Overall plant emissions are about 660 pounds of sulfur
oxide per ton (330 kg/MT) of concentrated ore.
Table 7-7. EMISSION FACTORS FOR PRIMARY ZINC SMELTING
WITHOUT CONTROLS3
EMISSION FACTOR RATING: B
Type of operation
Roasting (multiple-hearth)b
Sinteringc
Horizontal retorts6
Vertical retorts6
Electrolytic process
Particulates
Ib/ton
120
90
8
100
3
kg/MT
60
45
4
50
1.5
Sulfur oxides
Ib/ton
1100
d
-
-
-
kg/MT
550
d
-
-
-
Approximately 2 unit weights of concentrated ore are required
to produce 1 unit weight of zinc metal. Emission factors
expressed as units per unit weight of concentrated ore
.produced.
^References 1C and 14.
.References 10 and 30.
Included in S09 losses from roasting.
Reference 10.
To produce a high-quality aluminum product, fluxing is practiced to some
extent in all secondary aluminum melting. Aluminum fluxes are expected to
remove dissolved gases and oxide particles from the molten bath. Sodium and
various mixtures of potassium or sodium chloride with cryolite and chlorides of
aluminxim zinc are used as fluxes. Chlorine gas is usually lanced into the molten
7-10
E ISSIO FACTORS
2/72
-------
bath to reduce the magnesium content by reacting to form magnesium and alum*
inum chlorides, 33, 34
Emissions^ - Emissions from secondary aluminum operations include fine pantic-
ulate matter and gaseous chlorine. A large part of the material charged to a
reverberatory furnace is low-grade scrap and chips. Paint, dirt, oil, grease,
and other contaminants from this scrap cause large quantities of smoke and furties
to be discharged. Even if the scrap is clean., large surface-to-volume ratios
require the use of more fluxes, which can cause serious air pollution problems*
Table 7-8 presents particulate emission factors for secondary aluminum operations.
Table 7-8. PARTICULATE EMISSION FACTORS FOR SECONDARY ALUMINUM OPERATIONS8
EMISSION FACTOR FATING: 8
Type of operation
Sweating furnace
Smelting
Crucible furnace
Reverberatory furnace
Chlori nation station'3
Uncontrol led
Ib/ton
14,5
1.9
4.3
1000
kg/MT
7.25
0.95
2.15
500
Baghouse
Ib/ton
3.3
—
1.3
50
kg/MT
1.65
—
0.65
25
Electrostatic
preci pita tor
1b/ton
--
—
1.3
—
kg/MT
-.
—
0.65
--
Reference 35. Emission factors expressed as units per unit weight of metal1
processed.
Pounds per ton (kg/MT) of chlorine used,
Brass and Bronze Ingots (Copper Alloys)
Process Description^" - Obsolete domestic and industrial copper-bear ing scrap is
the basic raw material of the brass and bronze ingot industry. The scrap fre-
quently contains any number of metallic and non-metallic impurities, which can be
removed by such methods as hand sorting, magnetizing, heat methods such as
sweating or burning, and gravity separation in a water medium.
Brass and bronze ingots are produced from a number of different furnaces
through a combination of melting, smelting, refining, and alloying of the processed
scrap material. Reverberatory, rotary, and crucible furnaces are the ones most
widely used, and the choice depends on the size of the melt and the alloy desired.
Both the reverberatory and the rotary furnaces are normally heated by direct
firing, in which the flame and gases come into direct contact -with the melt. Pro-
cessing is essentially the same in any furnace except for the differences in the
types of alloy being handled. Crucible furnaces are usually much smaller and are
used principally for special-purpose alloys,
Emissions and Cpntrols3o - The principal source of emissions in the brass and
bronze ingot industry is the refining furnace. The exit gas from the furnace ms|y
contain the normal combustion products such as fly ash, soot, and smoke. Appre-
ciable amounts of zinc oxide are also present in this exit gas. Other sources of
2/72
Metallurgical Industry
-------
particulate emissions include the preparation of raw materials and the pouring of
ingots.
The only air pollution control equipment that is generally accepted in the
brass and bronze ingot industry is the baghouse filter, which can reduce emissions
by as much as 99. 9 percent. Table 7-9 summarizes uncontrolled emissions from
various brass and bronze melting furnaces.
Table 7-9. PARTICULATE EMISSION FACTORS
FOR BRASS AND BRONZE MELTING FURNACES
WITHOUT CONTROLS3
EMISSION FACTOR RATING: A
Type of furnace
Blastc
Crucible
Cupola
Electric induction
Reverberatory
Rotary
Uncontrolled
emissions^
Ib/ton
18
16
73
2
70
60
kg/MT
9
8
36.5
1
35
30
Reference 37. Emission factors
expressed as units per unit weight of
.metal charged.
The use of a baghouse can reduce
emissions by 95 to 99.6 percent.
Represents emissions following pre-
cleaner
Gray Iron Foundry
,38
Process Description - Three types of furnaces are used to produce gray iron
castings: cupolas, reverberatory furnaces, and electric induction furnaces. The
cupola is the major source of molten iron for the production of castings. In opera-
tion, a bed of coke is placed over the sand bottom in the cupola. After the bed of
coke has begun to burn properly, alternate layers of coke, flux, and metal are
charged into the cupola. Combustion air is forced into the cupola, causing the
coke to burn and melt the iron. The molten iron flows out through a taphole.
Electric furnaces are commonly used where special alloys are to be made.
Pig iron and scrap iron are charged to the furnace and melted, and alloying
elements and fluxes are added at specific intervals. Induction furnaces are used
where high-quality, clean metal is available for charging.
Emissions^° - Emissions from cupola furnaces include gases, dust, fumes, and
smoke and oil vapors. Dust arises from dirt on the metal charge and from fines
in the coke and limestone charge. Smoke and oil vapor arise primarily from the
partial combustion and distillation of oil from greasy scrap charged to the furnace.
Also, the effluent from the cupola furnace has a high carbon monoxide content that
7-12
EMISSION FACTORS
2/72
-------
can be controlled by an afterburner. Emissions from reverberatory and electric
induction furnaces consist primarily of metallurgical fumes and are relatively Ijow.
Table 7-10 presents emission factors for the manufacture of iron castings.
Table 7-10. EMISSION FACTORS FOR GRAY IRON FOUNDRIES
EMISSION FACTOR RATING: B
a,b,c
Type of furnace
Cupola
Unccntrol led
Uet cap
Impingement scrubber
High-energy scrubber
Electrostatic precipitator
Baghouse
Reverberatory
Elactric induction
Particulates
Ib/ton
17
8
5
0.8
0.6
0.2
2
1.5
kg/MT
8.5
4
2.5
0.4
0.3
0.1
1
0.75
Carbon monoxide
Ib/ton
145c»d
-
-
kg/MT
72.5c'd
-
-
References 35, and 39 through 41. Emission factors expressed as
units per unit weight of metal charged.
Approximately 35 percent of tiie total charge is metal. For
every unit weight of coke in the charge, 7 unit weights of gray
iron are produced.
'Reference 42.
A well-designed afterburner can ri
ton (4.5 kg/MT) of metal charged.-
juce emissions, to 9 pounds per
Secondary Lead Smelting
General Description - Three types of furnaces are used to produce the common
types of lead: the pot furnace, the reverberatory furnace, and the blast furnacte or
cupola. The pot furnaces are used for the production of the purest lead products,
and they operate under closely controlled temperature conditions. Reverberatdry
furnaces are used for the production of semi-soft lead from lead scrap, oxides,,
and drosses. The third common type of furnace, the blast furnace, is used to
produce hard lead (typically averaging 8 percent antimony and up to 2 percent
additional metallic impurity). The charge to these furnaces consists of rerun,
slag, and reverberatory slags.
Emissions and Controls - The primary emissions from lead smelting are partic-
ulates consisting of lead, lead oxides, and contaminants in the lead charged.
Carbon monoxide is released by the reduction of lead oxide by carbon in the cupola.
Nitrogen oxides are formed by the fixation of atmospheric nitrogen, caused by the
high temperatures associated with the smelting.
Factors affecting emissions from the pot furnace include the composition pf
the charge, the temperature of the pot, and the degree of control (usually hooding
followed by a baghouse). Emissions from ithe reverberatory furnace are affected
2/72
Metallurgical Industry
7-13
-------
by the sulfur content in the charge, the temperature in the furnace, and the amount
of air pulled across the furnace. Lead blast-furnace emissions are dependent on
the amount of air passed through the charge, the temperature of the furnace, and
the amount of sulfur and other impurities in the charge. In addition, blast furnaces
emit significant quantities of carbon monoxide and hydrocarbons that must be con-
trolled by incineration. Table 7-11 summarizes the emission factors from lead
smelting.
Secondary Mag esium Smelting
Process Description' - Magnesium smelting is carried out in crucible or pot-type
furnaces that are charged with magnesium scrap and fired by gas, oil, or electric
heating. A flux is used to cover the surface of the molten metal because magne-
sium will burn in air at the pouring temperature (approximately 1500° F or 815° C).
The molten magnesium, usually cast by pouring into molds, is annealed in ov.ens
utilizing an atmosphere devoid of oxygen.
Emissions - Emissions from magnesium smelting include particulate magnesium
(MgO) from the melting, oxides of nitrogen from the fixation of atmospheric nitro-
gen by the furnace temperatures, sulfur dioxide losses from annealing oven
atmospheres. Factors affecting emissions include the capacity of the furnace; the
type of flux used on the molten material; the amount of lancing used; the amount of
contamination of the scrap, including oil and other hydrocarbons; and the type and
extent of control equipment used on the process. The emission factors for a pot
furnace are shown in Table 7-12.
Steel Fou dries
Process Description' - Steel foundries produce steel castings by melting steel
metal and pouring it into molds. The melting of steel for castings is accomplished
in one of five types of furnaces: direct electric-arc, electric induction, open-
hearth, crucible, and pneumatic converter. The crucible and pneumatic converter
are not in widespread use, so this section deals only with the remaining three
types of furnaces. Raw materials supplied to the various melting furnaces include
steel scrap of all types, pig iron, ferroalloys, and limestone. The basic melting
process operations are furnace charging, melting, tapping the furnace into a ladle,
and pouring the steel into molds. An integral part of the steel foundry operation
is the preparation of casting molds, and the shakeout and cleaning of these castings.
Some common materials used in molds and cores for hollow casting include sand,
oil, clay, and resin. Shakeout is the operation by which the cool casting is sepa-
rated from the mold. The castings are commonly cleaned by shot-bias ting, and
surface defects such as fins are removed by burning and grinding.
Emis^sions ' - Particulate emissions from steel foundry operations include iron
oxide fumes, sand fines, graphite, and metal dust. Gaseous emissions from
foundry operations include oxides of nitrogen, oxides of sulfur, and hydrocarbons.
Factors affecting emissions from the melting process include the quality and
cleanliness of the scrap and the amount of oxygen lancing. The concentrations of
oxides of nitrogen are dependent upon operating conditions in the melting unit,
such as temperature and the rate of cooling of the exhaust gases. The concentra-
tion of carbon monoxide in the exhaust gases is dependent on the amount of draft
7-14 EMISSION FACTORS 2/72
-------
CD
ST
r>
at
Table 7-11. EMISSION FACTORS FOR LEAD SMELTING
EMISSION FACTOR RATING: C
Type of furnace
Pot furnace3
Reverberatory furnace
Blast {cupola} furnace0
Rotary reverberatory furnace
Particulates
Uncontrolled
1 b/ton
0.8
130
190
70
kg/MT
0.4
65
95
35
Controlled
1 b/ton
Neg
1.6
2.3
-
kg/MT
Neg
0.8
1.15
-
Sulfur oxides
Uncontrol 1 ed
1 b/ton
.-
85
SO
-
kg/MT
.
42.5
45
-
Controlled
1 b/ton
_
-
0.8,d 46e
-
kg/MT
-
-
0.4,d 23e
-
aReferences 34, and 44 through 46. Emission factors expressed as units per unit weight of
metal processed.
References 34, 43, and 46.
References 43, 46, and 47.
dWith NaOH scrubber,
£%
With water spray chamber.
Reference 45.
-------
Table 7-12. EMISSION FACTORS
FOR MAGNESIUM SMELTING
EMISSION FACTOR RATING: C
Type of furnace
Pot furnace
Uncontrolled
Controlled
Parti culates
1 b/ton
4
0.4
. kg/MT
2
0.2
References 34 and 46. Emission
factors expressed as units per unit
weight of metal.processed.
on the melting furnace. Emissions from the shakeout and cleaning operations,
mostly partieulate matter, vary according to type and efficiency of dust collection.
Gaseous emissions from the mold and baking operations, are dependent upon the
fuel used by the ovens and the temperature reached in these ovens. Table 7-13 sum-
marizes the emission factors for steel foundries.
Table 7-13. 'EMISSION FACTORS'FOR STEEL FOUNDRIES
EMISSION FACTOR RATING: A
Type of process
Melting • '
Electric arc jC
Open-hearthd'e
Open-hearth oxygen lanced '9
Electric induction
i i nn '" - * '" — '"
Particulates3
1 b/ton
13 (4 to 40)
11 (2 to 20)
10 (8 to 11)
0,1
kg/MT
6.5 (2 to 20).
5.5 (1 to 10)
5 (4 to 5.5)
0.05
Nitrogen
oxides
1 b/ton
0.2
0.01
-
-
kg/MT
0.1
0.005
-
-
Emission factors expressed as units per unit weight of metal processed.
If the scrap metal is very dirty or oily, or if increased oxygen lancing
is employed, the emission factor should be chosen from the high side of
the factor range.
Electrostatic precipitator, 92 to 98'percent control efficiency; big-house
(fabric filter), 98 to 99 percent control efficiency; venturi scrubber,
94 to 98 percent control efficiency.
References 24 and 48 through 56, -
Electrostatic precipitator, 95 to 98.5 percent control efficiency; bag-
house, 99.9 percent control efficiency; venturi scrubber, 96 to 99 per-
cent control efficiency.
eReferences 24, and 57 through 59. .. . •
fElectrostatic precipitator, 95 to 98 percent control efficiency; bag-
house, 99 percent control efficiency; venturi scrubber, 95 to 98 percent
control efficiency. .. .
^References 52 and 60.
Usually not controlled.
7-16
E ISSIO FACTORS
2/72
-------
Secondary Zinc Processing i
Process Description - Zinc processing includes zinc reclaiming, zinc oxide
manufacturing, and zinc galvanizing. Zinc is separated from scrap containing
lead, copper, aluminum, and iron by careful control of temperature in the furnace,
allowing each metal to be removed at its melting range. The furnaces typically!
employed are the pot, muffle, reverberatory, or electric induction. Further
refining of the zinc can be done in retort distilling or vaporization furnaces whete
the vaporized zinc is condensed to the pure metallic form. Zinc oxide is produced
by distilling metallic zinc into a dry air stream and capturing the subsequently
formed oxide in a baghouse. Zinc galvanizing is carried out in a vat or in bath-
type dip tanks utilizing a flux cover. Iron and steel pieces to be coated are
cleaned and dipped into the vat through the covering flux.
jjmissions - A potential for particulate emissions, mainly zinc oxide, occurs if
the temperature of the furnace exceeds 1100° F (595° C). Zinc oxide (ZnO) may
escape from condensers or distilling furnaces, and because of its extremely smjall
particle size (0. 03 to 0. 5 micron), it may pass through even the most efficient
collection systems. Some loss of zinc oxides occurs during the galvanizing pro-
cesses, but these losses are small because of the flux cover on the bath and the
relatively low temperature maintained in the bath. Some emissions of particulale
ammonium chloride occur when galvanized parts are dusted after coating to im--
prove their finish. Another potential source of emissions of particulates and
gaseous zinc is the tapping of zinc-vaporizing muffle furnaces to remove accumu-
lated slag residue. Emissions of carbon monoxide occur when zinc oxide is
reduced by carbon. Nitrogen oxide emissions are also possible because of the
high temperature associated with the smelting and the resulting fixation of atmos-
pheric nitrogen. Table 7-14 summarizes the emission factors from zinc processing.
Table 7-14. PARTICULATE EMISSION FACTORS FOR SECONDARY ZINC SMELTING8
EMISSION FACTOR RATING: C
Type of furnace •
Retort reduction
Horizontal muffle
Pot furnace
Kettle sweat furnace processing'3
Clean metallic scrap
General metallic scrap
Residual scrap
Reverberatory sweat furnace processing
Clean metallic scrap
General metallic scrap
Residual scrap
Galvanizing kettles
Calcining kiln
Emissions
Ib/ton
47
45
0.1
Neg
11
25
Neg
13
32
5
89
kg/MT
23.5
22.5
0.05
Neg
5.5
12,5
Neg
6.5
16
2.5'
44.5
References 34, 45, and 46. Emission factors expressed as units
unit weight of metal produced,
Reference 61.
per
2/72
Metallurgical Industry
7rl7
-------
REFERENCES FOR CHAPTER 7
1, Stern, A. (ed.). Sources of Air Pollution and Their Control, 2nd Ed. Air
Pollution III, New York, Academic Press, 1968, p. 186-188.
2. Hendricks, R, V, , Jr. Unpublished report on the primary aluminum industry.
National Air Pollution Control Administration, Division of Process Control
Engineering. Cincinnati, Ohio. 1969.
3. Duprey, R.L. Compilation of Air Pollutant Emission. Factors, U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42. 1968. p. 23-24.
4. Air Pollution from the Primary Aluminum Industry. A Report to Washington
Air Pollution Control Board, Office of Air Quality Control, Washington State
Department of Health. Seattle, Washington. October 1969.
5. Ott, R.R.. Control of Fluoride Emissions at Harvey Aluminum, Inc.:
Soderberg Process Aluminum Reduction Mill. J. Air Pollution Control
Assoc. J_3(9);437-443. September 1963.
6, Kenline, P. A, Unpublished report, Control of Air Pollutants from the
Chemical Process Industries. Robert A. Taft Sanitary Engineering Center.
Cincinnati, Ohio. May 1959.
7, Air Pollutant Emission Factors, Final Report, Resources Research, Incor
porated, Reston, Virginia. Prepared for National Air Pollution Control
Administration under contract No. CPA-22-69-119. April 1970,
8. Air Pollution by Coking Plants. United Nations Report; Economic Commis-
sion for Europe, ST/ECE/Coal/26. 1968, p. 3-27.
9, Fullerton, R,W. Impingement Baffles to Reduce Emissions from Coke
Quenching. J. Air Pollution Control Assoc. 17:807-809. December 1967.
10. Sallee, G. Private Communication on Particulate Pollutant Study, Midwest
Research Institute, National Air Pollution Control Administration Contract
No 22-69-104. June 1970.
11. Herring, W, Secondary Zinc Industry Emission Control Problem Definition
Study (Part I), Office of Air Programs, EPA, APTD-0706, May 1971.
12. Duprey, R. L. Compilation of Air Pollutant Emission Factors, U.S. DHEW
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42. 1968, p. 24.
13, Stern, A. (ed,), Sources of Air Pollution and Their Control. 2nd Ed. Air
Pollution III. New York, Academic Press, 1968. p. 173-179.
14. Systems Study for Control of Emissions in the Primary Nonferrous Smelting
Industry. 3 Volumes. San Francisco, California, Arthur G. McK.ee and
Company, June 1969.
7-18 FACTORS 2/72
-------
15, Ferroalloys; Steel's All-purpose Additives, The Magazine of-Metals 'Produc-
cing. February 1967.
16. Person, R. A. Control of Emissions from Ferroalloy Furnace Processing,
Niagara Falls, New York, 1969, ,
17. Unpublished stack test results. Resources Research, Incorporated. Reston,
Virginia.
18. Ferrari, R. Experiences in Developing an Effective Pollution Control System
for a Submerged-Arc Ferroalloy Furnace Operation. J, Metals: April 1968.
p. 95-104.
19. Fredriksen and Nestaas. Pollution Problems by Electric Furnace Ferroalloy
Production. United Nations Economic Commission for Europe. September
1968.
20. Gerstle, R.W, andJ.L. McGinnity. Plant Visit Memorandum. U.S. DHEW,
PHS. June 1967.
21. Duprey, R.L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-4Z. 1968. p. 24-25.
22, Stern, A. (ed.). Sources of Air Pollution and Their Control. 2nd Ed. Air
Pollution III. New York, Academic Press, '1968. p. 146-163.
23. Control Techniques for Carbon Monoxide Emissions from Stationary Sources.
U.S. DHEW, PHS, EHS, National Air Pollution Control Administration.
Washington, D. C. Publication No. AP-65. March 1970.
24, Schueneman, J. J. et al. Air Pollution Aspects of the Iron and Steel Industry.
National Center for Air Pollution Control. Cincinnati, Ohio. June 1963.
25. Unpublished data on iron and steel mills updated to 1968 practices. Based on
data from National Air Pollution Control Administration under Contract PH- •
22-68-65, 1969.
26. Iron and Steel Making Process Flow Sheets and Air Pollutant Controls.
American Conference of Governme nt Industrial Hygienists.
27. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N.C. PHS Publi-
cation No. 999-AP-42. 1968. p. 26.
,_ Stern, A. (ed.). Sources of Air Pollution and Their Control. 2nd Ed, Air
Pollution III. New York, Academic Press, 196B. p. 179-182.
29, Duprey. R. L. Compilation of Air Pollutant Emission Factors. U.S. DHlCW,
PHS, National Center for Air Pollution Control. Durham, N.C. PHS Publi-
cation No. 999-AP-42. 1968. p. 26-28.
30. Stern, A. (ed.). Sources of Air Pollution and Their Control. 2nd Ed, Air
Pollution III, New York, Academic Press, 1968. p. 182-186.
2/72 Metallurgical Industry 7-19
-------
31. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N..C. PHS Publi-
cation No. 999-AP-42. 1968. p. 29.
32. Hammond, W.F. and H. Simon. Secondary Aluminum-Melting Processes.
In: Air Pollution Engineering Manual. Danielson, J. A, (,ed.), U.S. DHEW,
PHS, National Center for Air Pollution Control. Cincinnati, Ohio. Publica-
tion No. 999-AP-40. 1967. p. 284-290.
33. Technical Progress Report: Control of Stationary Sources. Los Angeles
County Air Pollution Control District, _!_, April I960.
34, Allen, G.L. et al. Control of Metallurgical and Mineral Dusts and Fumes in
Los Angeles County. Bureau of Mines, Washington, D. C. Information
Circular No. 7627. April 1952.
35. Hammond, W.F. and S.M. Weiss. Unpublished report on air contaminant
emissions from metallurgical operations in Los Angeles County. Los Angeles
County Air Pollution Control District. Presented at Air Pollution Control
Institute, July 1964.
36. Air Pollution Aspects of Brass and Bronze Smelting and Refining Industry.
U.S. DHEW, PHS, EHS, National Air Pollution Control Administration.
Raleigh, N. C. Publication No. AP-58. November 1969-
37, Air Pollution Aspects of Brass and Bronze Smelting and Refining Industry.
U.S. DHEW, PHS, EHS, National Air Pollution Control Administration.
Raleigh, N. C. Publication No. AP-58. November 1969-
38. Hammond, W.F, and J. T. Nance. Iron Castings, In: Air Pollution Engineer-
ing Manual. Danielson, J.A. (ed. ). U.S. DHEW, PHS, National Center for
Air Pollution Control. Cincinnati, Ohio. Publication No. 999-AP-40. 1967.
p. 258-268.
39. Crabaugh, H. C. et al. Dust and Fumes from Gray Iron Foundries; How They
Are Controlled in Los Angeles County. Air Repair. 4(3), November 1954.
40. Hammond, W. F. , and J. T. Nance. Iron Castings. In: Air Pollution .
Engineering Manual. Danielson, J. A. (ed.). U.S. DHEW, PHS, National
Center for Air Pollution Control, Cincinnati, Ohio. Publication No. 999-
AP-40. 1967. p. 260.
41. Kane, J.M. Equipment for Cupola Control. American Foundryman's Society
Transactions. 64:525-531. 1956.
42. A. T.Kearney and Company, Inc. , Air Pollution Aspects of the Iron Foundry
Industry. Contract No. CPA 22-69-106. February 1971.
43. Nance, J. T. and K. O. Luedtke. Lead Refining. In; Air Pollution Engineering
Manual. Danielson, J.A. (ed.). U.S. DHEW, PHS, National Center for Air
Pollution Control. Cincinnati, Ohio. Publication No. 999-AP-40. 19.67.
p. 300-304,
7-20 EMISSION FACTORS 2/72
-------
44. Private communication between Resources Research, Incorporated, and
Maryland State Department of Health. November 1969.
45. Restricting Dust and Sulfur Dioxide Emissions from Lead Smelters (trans-
lated from German). Kommission Reinhaltung der Luft. Reproduced by U.S.
DREW, PHS. Washington, D. C. VDI No. 2285. September 1961.
46. Hammond, W.F0 Data on Non-Ferrous Metallurgical Operations. Los
Angeles County Air Pollution Control District. November 1966.
47. Unpublished stack test data. Pennsylvania State Department of Health.
Harrisburg, Pa. 1969.
48. Foundry Air Pollution Control Manual. 2nd. ed. Des Plaines, Illinois,
Foundry Air Pollution Control Committee. 1967. p. 8.
49. Coulter, R.S. Bethlehem Pacific Coast Steel Corporation, Personal Com-
munication (April 24, 1956) as cited in Air Pollution Aspects of the Iron and
Steel Industry.
50. Coulter, R.S. Smoke, Dust, Fumes Closely Controlled in Electric Furnaces.
IronAge. 173:107-110. January 14, 1954.
51. Los Angeles County Air Pollution Control District, Unpublished data as cited
in Air Pollution Aspects of the Iron and Steel Industry. Reference 254, p. 109.
52. Kane, J.M. and R. V. Sloan. Fume-Control Electric Melting Furnaces.
American Foundryman. ^_8:33-35, November 1950,
53. Pier, H. M. aiidH.S. Baurngardner. Research-Cottrell, Inc., Personal
Communication as cited in Air Pollution Aspects of the Iron and Steel Industry.
Reference 254, p. 109.
54. Faist, C.A0 Remarks-Electric Furnace Steel. Proceedings of the American
Institute of Mining and Metallurgical Engineers. 11:160-161, 1953.
55. Faist, C.A. Burnside Steel Foundry Company, Personal Communication as
cited in Air Pollution Aspects of the Iron and Steel Industry. Reference 254,
p. 109.
56. Douglas, I. H. Direct Fume Extraction and Collection Applied to a Fifteen-
Ton Arc Furnace. Special Report on Fume Arrestment. Iron and Steel
Institute. 1964. p. 144, 149.
57. Inventory of Air Contaminant Emissions. New York State Air Pollution
Control Board. Table XI, p. 14-19,
58. Elliot, A.C. and A. J. Freniere. Metallurgical Dust Collection in Open-
Hearth and Sinter Plant. Canadian Mining and Metallurgical Bulletin.
55(606):724-732, October 1962.
2/72 Metallurgical Industry 7-21
-------
59. Hemeon, C, L. Air Pollution Problems of the Steel Industry. Air Pollution
Control Assoc. 10(3);208-218, March I960.
60. Coy, D. W. Unpublished data. Resources Research, Incorporated. Reston,
Virginia.
61. Herring, W. Secondary Zinc Industry Emission Control Problem Definition
Study (Part I), Office of Air Programs, EPA. APT D-0706. May 1971.
7-22 E ISSIO FACTORS 2/
-------
8. MINERAL PRODUCTS INDUSTRY
This section involves the processing and production of various minerals.
Mineral processing is characterized by particulate emissions in the form of dust.
Frequently, as in the case of crushing and screening, this dust is identical to the
material being handled. Emissions also occur through handling and storage of the
finished product because this material is often dry and fine. Particulate emis-
sions from some of the processes such as quarrying, yard storage, and road dust
are difficult to control. Most of the emissions from the manufacturing processes
discussed in this section, however, can be reduced by conventional particulate
control equipment such as cyclones, scrubbers, and fabric filters. Because of
the wide variety in processing equipment and final product, emissions cover a
wide range; however, average emission factors have been presented for general
use.
ASPHALT BATCHING
Process Description1'2
Hot-mix asphalt paving consists of a combination of aggregates uniformly
mixed and coated with asphalt cement. The coarse aggregates usually consist
of crushed stone, crushed slag, crushed gravel, or combinations of these
materials. The fine aggregates usually consist of natural sand and may contain
added materials such as crushed stone, slag, or gravel.
An asphalt batch plant involves the use of a rotary dryer, screening and
classifying equipment, an aggregate weighing system, a mixer, storage bins, and
conveying equipment. Sand and aggregate are charged from bins into a rotary
dryer. The dried aggregate is conveyed to the screening equipment, where it is
classified and dumped into storage bins. Asphalt and weighed quantities of sized
aggregates are then dropped into the mixer, where the batch is mixed and then
dumped into trucks for transportation to the paving site.
Emissions and Controls1'2
The largest source of dust emissions is the rotary dryer. Combustion gases
and fine dust from the rotary dryer are exhausted through a precleaner, which
usually consists of a single cyclone, although twin or multiple cyclones are also
used. The exit gas stream of the precleaner usually passes through air pollution
control equipment. Other sources of dust emissions include the hot aggregate
bucket elevator, vibrating screens, hot aggregate bins, aggregate weigh hopper,
and the mixer. Emission factors for asphalt batching plants are presented in
Table 8-1.
ASPHALT ROOFING
Process Description ^
The manufacture of asphalt roofing felts and shingles involves saturating
fiber media with asphalt by means of dipping and/or spraying. Although it is not
2/72 8-1
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Table 8-1. PARTICULATE EMISSION FACTORS FOR ASPHALT
PLANTS9
EMISSION FACTOR RATING: B
Source and type of control
Rotary dryerb
Uncontrolled0'*1
Preeleaner
High-efficiency cyclone
Multiple centrifugal scrubber
Baffle spray tower
Orifice-type scrubber
Baghouse
Other sources, uncontrolled
(vibrating screens, hot
aggregate bins, aggregate
weigh hopper, and mixer)c
Emissions
Ib/ton
kg/MT
35
5
0.8
0,2
0.2
0.08
0.005
10
'17.5
2.5
0.4
0.1
0.1
0.04
0,0025
5
Emission factors expressed as units per unit weight
of asphalt produced.
^References 2 through 5,
cReferences 2S 6, and 7.
Almost all plants have at least a precleaner following
the rotary dryer.
always done at the same site, preparation of the asphalt saturant is an integral
part of the operation. This preparation, called "blowing, " consists of oxidizing
the asphalt by bubbling air through the liquid asphalt for 8 to 16 hours. The
saturant is then transported to the saturation tank or spray area. The saturation
of the felts is accomplished by dipping, high-pressure sprays, or both. The final
felts are made in various weights: 15, 30, and 55 pounds per 100 square feet
(0. 72, 1. 5, and 2. 7 kg/m2). Regardless of the weight of the final product, the
imakeup is approximately 40 percent dry felt and 60 percent asphalt saturant.
Emissions and Controls8
The major sources of particulate emissions from asphalt roofing plants are
the asphalt blowing operations and the felt saturation. Another minor source of
particulates is the covering of the roofing material with roofing granules. Gaseous
emissions from the saturation process have not been measured but are thought to
be slight because of the initial driving off of contaminants during the blowing
process.
A common method of control at asphalt saturating plants is the complete
enclosure of the spray area and saturate? with good ventilation through one or
more collection devices, which include combinations of wet scrubbers and two-
stage low-voltage electrical precipitators, or cyclones and fabric filters,
Emission factors for asphalt roofing are presented in Table 8-2.
3-2
E ISSIO FACTORS
2/72
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Table 8-2. EMISSION FACTORS FOR ASPHALT ROOFING MANUFACTURING
WITHOUT CONTROLS3
EHISSION FACTOR RATING: D
Operation
Asphalt blowing1"
Felt saturation
Dipping only
Spraying only
Dipping and spraying
Participates^3
1 b/ton
2.5
1
3
2
kg/MT
1.25
0.5
1.5
1
Carbon
monoxide
1 b/ton
0.9
-
-
kg/MT
0.45
-
-
-
Hydrocarbons
(CH4)
1 b/ton
1.5
-
-
-
kg/MT
0.75
-
-
-
Approximately 0.65 unit of asphalt input is required to produce
1 unit of saturated felt. Emission factors expressed as units
per unit weight of saturated felt produced.
Low-voltage precipitators can reduce emissions by about 60 percent;
when they are used in combination with a scrubber, overall effi-
ciency is about 85 percent.
Reference 9.
References 10 and 11.
BRICKS AND RELATED CLAY PRODUCTS
Process Description8-12~14
The manufacture of brick and related products such as clay pipe, pottery,
and some types of refractory brick involves the grinding, screening, and blendjing
of the raw materials and the forming, drying or curing, firing, and cutting or
shaping of the final product. ]
The drying and firing of pressed bricks, both common and refractory, are
accomplished in many types of ovens, the most popular being the long tunnel ;
oven. Common brick or building brick is prepared by molding a wet mix of 20;to
25 percent water and 75 to 80 percent clay, then baking it in chamber kilns.
Common brick is also prepared by extrusion of a stiff mix (10 to 12 percent water),
followed by the pressing and baking of sections cut from the extrusion.
Emissions and Controls8
Particulate emissions similar to those obtained in clay processing are
emitted from the materials handling process in refractory and brick manufactur-
ing. Combustion products are emitted from the fuel consumed in the curing,
drying, and firing portion of this process, and fluorides, largely in a gaseous
form, are emitted from brick manufacturing operations. Sulfur dioxide may also
be emitted from the bricks when firing temperatures are 2500° F (1370° C) or
more, or when the fuel contains sulfur,
A variety of control systems may be used to reduce both particulate and
gaseous emissions. Almost any type of particulate control system will reduce
emissions from the materials handling process. Fluoride emissions can be
2/72
Mineral Products Industry
8-3
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reduced to very low levels by using a water scrubber. Emission factors for
brick manufacturing are presented in Table 8-3,
Table 8-3. EMISSION FACTORS FOR BRICK MANUFACTURING WITHOUT CONTROLS3
FACTOR RATING; D
Type of process
Raw material handling0
Dryi ng
Grinding
Storage
Curing and firing^
Gas-fired
Oil -fired
Coal -fired
Participate
1 b/ton
70
76
34
Neg
Neg
5A to 10Ae
kg/MT
35
38
17
Neg
Neg
2.5A to 5Ae
Nitrogen
oxides (NQj)
1 b/ton
-
-
0.6
1.3
1,5
kg/MT
-
-
-
0.3
0.65
0.75
Fluorides'3
1 b/ton
-
-
-
0.8
0.8
0.8
kg/MT
-
-
-
0.4
0.4
0.4
aOne brick weighs about 6.5 pounds (2.95 kg). Emission factors expressed
as units per unit weight of bricks produced.
Expressed as HF and based on a raw material content of 0.05 percent by
weight fluoride.
cBased on data from section on ceramic clays.
References 13, and 15 through 17.
eA is the percentage of ash in the coal, and emissions are given on the
basis of pounds per ton (kg/MT) of fuel used. This is an estimate based
on coal-fired furnaces.
CALCIUM CARBIDE MANUFACTURING
Process Description1^' ^ :
Calcium carbide is manufactured by heating a mixture of quicklime (CaO)
and carbon in an electric-arc furnace, where the lime is reduced by the coke to
calcium carbide and carbon monoxide. Metallurgical coke, petroleum coke, or
anthracite coal is used as the source of carbon. About 1, 900 pounds (860 kg) of
lime and 1, 300 pounds (600 kg) of coke yield 1 ton (1 MT) of calcium carbide.
There are two basic types of carbide furnaces; (1) the open furnace, in which the
carbon monoxide burns to carbon dioxide when it comes in contact with air above
the charge; and (2) the closed furnace, in which the gas is collected from the
furnace. The molten calcium carbide from the furnace is poured into chill cars or
bucket conveyors and allowed to solidify. The finished calcium carbide is dumped
into a jaw crusher and then into a cone crusher to form a product of the desired
size.
Emissions and Controls
Participates, acetylene, sulfur compounds, and some carbon monoxide are
emitted from calcium carbide plants. Table 8-4 contains emission factors based on
one plant in which some particulate matter escapes from the hoods over each
8-4
E ISSIO FACTORS
2/72
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Table 8-4. EMISSION FACTORS FOR CALCIUM CARBIDE PLANTS3
EMISSION FACTOR RATING: C
Type of source
Electric furnace
Hoods
Main stack
Coke dryer
Furnace room vents
Particulates
Ib/ton
18
20
2
26
kg/MT
9
10
1
13
Sulfur oxides
Ib/ton
-
3
3
-
kg/MT
-
1.5
1.5
-
Acetylene
Ib/ton
-
-
-
18
kg/MT
-
-
-
9
^Reference 20. Emission factors expressed as units per unit
weight of calcium carbide produced.
furnace and the remainder passes through wet-impingement-type scrubbers before
being vented to the atmosphere through a stack. The coke dryers and the furnace -
room vents are also sources of emissions.
CASTABLE REFRACTORIES
Process Description^> 21, 22
Castable or fused-cast refractories are manufactured by carefully blending
such components as alumina, zirconia, silica, chrome, and magnesia; melting
the mixture in an electric-arc furnace at temperatures of 3200° to 4500° F (1760°
to 2430° C); pouring it into molds; and slowly cooling it to the solid state. Fused
refractories are less porous and more dense than kiln-fired refractories.
n
Emissions and Controls
Particulate emissions occur during the drying, crushing, handling, and
blending phases of this process, during the actual melting process, and in the
molding phase. Fluorides, largely in the gaseous form, may also be emitted
during the melting operations.
The general types of particulate controls may be used on the materials
handling aspects of refractory manufacturing. Emissions from the electric-arc
furnace, however, are largely condensed fumes and consist of very fine particles.
Fluoride emissions can be effectively controlled with a scrubber. Emission
factors for castable refractories manufacturing are presented in Table 8-5.
PORTLAND CEMENT MANUFACTURING
Process Description^
The raw materials required to make cement may be divided into the following
components: lime (calcareous), silica (siliceous), alumina (argillaceous), and
iron (ferriferous). The four major steps in the production of portland cement are:
(1) quarrying and crushing, (2) grinding and blending, (3) clinker production, and
(4) finish grinding and packaging.
2/72
Mineral Products Industry
8-5
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Table 8-5, PARTICULATE EMISSION FACTORS FOR CASTA8LE
REFRACTORIES MANUFACTURING3
EMISSION FACTOR RATING: C
Type of process
Raw material dryer0
Raw material crushing
and processi ngc
Electric-arc melting^
Curing oven6
Molding and shakeout^
Type of control
Baghouse
Scrubber
Cyclone
Baghoyse
Scrubber
Baghouse
Uncontrol 1 ed
Ib/ton
30
120
50
0.2
25
kg/MT
15
60
25
0.1
12.5
Controlled
1 b/ton
0.3
7
45
0.8
10
-
0.3
kg/MT
0.15
3.5
22.5
0.4
5
-
0.15
aFluoride emissions from the melt average about 1.3 pounds of HF per
ton of melt (0.65 kg HF/MT melt). Emission factors expressed as
units per unit weight of feed material.
bReference 23.
References 23 through 24.
References 23 through 25.
Reference 24.
In the first step the cement rock limestone, clay, and shale are worked in
open quarries. The rock from the quarries is sent through a primary and a
secondary crusher. The various crushed raw materials are properly mixed and
are then sent through the grinding operations, After the raw materials are
crushed and ground, they are introduced into a rotary kiln that is fired with
pulverized coal, oil, or gas. In the kiln the materials are dried, decarbonated,
and calcined to produce a cement clinker. The clinker is cooled, mixed, ground '
with gypsum, and bagged for shipment as cement,
Emissions and Controls2&> 27
Particulate matter is the primary emission in the manufacture of portland
cement, and it is emitted from crushing operations, storage silos, rotary dryers,
and rotary kilns. Dust production in the crusher area depends on the type and
moisture content of the raw material and on the characteristics and type of
crusher. In the process of conveying the crushed material to storage silos, sheds,
or open piles, dust is generated at various conveyor transfer points, A hood is
normally placed over each of these points to control particulate emissions,
Another major source of particulate matter is the rotary dryer. Hot gases
passing through the rotary dryer will entrain dust from the limestone, shale, or
other materials being dried. Control systems in common use include multi-
cyclones, electrostatic precipitators, and fabric filters.
The largest source of emissions within cement plants is the kiln operation,
which has three units; the feed system, a fuel-firing system, and a clinker-
cooling and -handling system. The complications of kiln burning and the large
E ISSIO FACTORS
2/72
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volumes of materials handled have led to many control systems for dust collection.
Because of the diversity of these control systems, they will not be discussed in
this publication. Table 8-6 summarizes participate emissions from cement manu-
facturing. The effect of control devices on emissions is shown in Footnote b.
Table 8-6. PARTICULATE EMISSION FACTORS
FOR CEMENT MANUFACTURING3
EMISSION FACTOR RATING: B
Type of process
Dry process
K11nsc
Dryers, grinder, etc.d
Wet process
Kilnsc
Dryers, grinders, etc.*'
Uncontrolled emissions'5
Ib/bbl
46 (35 to 75)
18 (10 to 30)
38 (15 to 55)
6 { 2 to 10)
kg/MT
123
48
100
16
One barrel of cement weighs 376 pounds (171 kg),
Typical collection efficiencies are: multi cyclones,
80 percent; old electrostatic precipitators, 90 per-
cent; multicyclones plus old electrostatic precipita
tors, 95 percent; multicyclones plus new electro-
static precipitators, 99 percent; and fabric filter
units, 99.5 percent.
Reference 26.
Reference 6.
CERAMIC CLAY MANUFACTURING
Process Description8
The manufacture of ceramic clay involves the conditioning of the basic ores
by several methods. These include the separation and concentration of the ;
minerals by screening, floating, wet and dry grinding, and blending of the desired
ore varieties. The basic raw materials in ceramic clay manufacture are kaol[inite
(A12O3 • 2S1O2 « 2H2O) and montmorillonite [(Mg, Ca) O- Al% 03- 5SiO2- nH^O],
clays. These clays are refined by separation and bleaching, blended, kiln-dried,
and formed into such items as whlteware, heavy clay products (brick, etc. ), ,
various stoneware, .and other products such as diatomaceous earth used as a
filter aid0
Emissions and Controls8 t
Emissions consist primarily of particulates, but some fluorides and acid
gases are also emitted in the drying process. The high temperatures of the fijring
kilns are also conducive to the fixation of atmospheric nitrogen and the subsequent
release of NO, but no published information has been found for gaseous emissions,
Particulates are also emitted from the grinding process and from storage of the
ground product,
2/72
Mineral Products Industry
3-7
-------
Factors affecting emissions include the amount of material processed, the
type of grinding (wet or dry), the temperature of the drying kilns, the gas veloci-
ties and flow direction in the kilns, and the amount of fluorine in the ores.
Common control techniques include settling chambers, cyclones, wet
scrubbers, electrostatic precipitators, and bag filters. The most effective con-
trol is provided by cyclones for the coarser material, followed by wet scrubbers,
bag filters, or electrostatic precipitators for dry dust. Emission factors for
ceramic clay manufacturing are presented in Table 8-7.
Table 8-7. PARTICULATE EMISSION FACTORS FOR CERAMIC CLAY MANUFACTURING3
EMISSION FACTOR RATING: A
Type of
process
Dryingd
Grinding6
Storage^
Uncontrolled
Ib/ton
70
76
34
kg/MT
35
38
17
Cycloneb
Ib/ton
18
19
8
kg/MT
9
9.5
4
Multiple-unit
cyclone and scrubber0
Ib/ton
7
-
-
kg/MT
3.5
- .
-'
aEmission factors expressed as units per unit weight of input to process.
^Approximate collection efficiency: 75 percent.
GApDroximate collection efficiency: 90 percent.
dReferences 28 through 31.
Reference 28.
CLAY AND FLY-ASH SINTERING
Process Descriptio 8
Although the processes for sintering fly ash and clay are similar, there are
some distinctions that justify a separate discussion of each process. Fly-ash
sintering plants are generally located near the source, with the fly ash delivered
to a storage silo at the plant. The dry fly ash is moistened with a water solution
of lignin and agglomerated into pellets or balls. This material goes to a travel-
ing-grate sintering machine where direct contact with hot combustion gases
sinters the individual particles of the pellet and completely burns off the residual
carbon in the fly ash. The product is then crushed, screened, graded, and stored
in yard piles.
Clay sintering involves the driving off of entrained volatile matter. It is
desirable that the clay contain a sufficient amount of volatile matter so that the
resultant aggregate will not be too heavy. It is thus sometimes necessary to mix
•3 o Q O
the clay with finely pulverized coke (up to 10 percent coke by weight). ' In the
sintering process the clay is first mixed with pulverized coke, if necessary, and
pelletized. The clay is next sintered in a rotating kiln or on a traveling grate.
The sintered pellets are then crushed, screened, and stored, in a procedure
similar to that for fly-ash pellets.
Emissions and Co trols8
In fly-ash sintering, improper handling of the fly ash creates a dust problem.
Adequate design features, including fly-ash wetting systems and particulate
8Q
-a
EMISSION FACTORS
2/72
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collection systems on all transfer points and on crushing and screening operations,
•would greatly reduce emissions. Normally, fabric filters are used to control |
emissions from the storage silo, and emissions are low. The absence of this •
dust collection system, however, would create a major emission problem,
Moisture is added at the point of discharge from the silo to the agglomerator, and
very few emissions occur there. Normally, there are few emissions from the'
sintering machine, but if the grate is not properly maintained, a dust problem is
created. The consequent crushing, screening, handling, and storage of the
sintered product also create dust problems,
In clay sintering, the addition of pulverized coke presents an emission prob-
lem because the sintering of coke-impregnated dry pellets produces more
particulate emissions than the sintering of natural clay. The crushing, screening,
handling, and storage of the sintered clay pellets creates dust problems similar
to those encountered in fly-ash sintering. Emission factors for both clay and
fly-ash sintering are shown in Table 8-8.
Table 8-8. PARTICULATE EMISSION FACTORS FOR SINTERING OPERATIONS3
EMISSION FACTOR RATING; C
Type of
material
Fly ashd
Clay mixed with
eokef>9
Natural clay^1
Sintering operation^5
Ib/ton
no
40
12
kg/MT
55
20
6
Crushing, screening,
and yard storageb5c
Ib/ton
e
15
12
kg/MT
e
7.5
6
aEmission factors expressed as units per unit weight of finished
product,
''Cyclones would reduce this emission by about 80 percent.
Scrubbers would reduce this emission by about 90 percent.
cBased on data in section on stone quarrying and processing.
dReference 8.
elncluded in sintering losses,
90 percent clay, 10 percent pulverized coke; traveling-grate,
single-pass, up-draft sintering machine.
References 30, 31, and 33.
"Rotary dryer sinterer.
^Reference 32.
COAL CLEANING
Process Descriptions
Coal cleaning is the process by which undesirable materials are removed
from bituminous and anthracite coal and lignite. The coal is screened, classified,
washed, and dried at coal preparation plants. The major sources of air pollution
from these plants are the thermal dryers. Seven types of thermal dryers are ,
presently used; rotary, screen, cascade, continuous carrier, flash or suspension,
multilouver, and fluidized bed. The three major types, however, are the flash,
rnultilouver, and fluidized bed.
2/72
Mineral Products Industry
8-9
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In the flash dryer, coal is fed into a stream of hot gases where instantaneous
drying occurs. The dried coal and wet gases are drawn up a drying column and
into the cyclone for separation. In the rrmltilouver dryer, hot gases are passed
through falling curtains of coal. The coal is raised by flights of a specially
designed conveyor. In the fluidized bed the coal is suspended and dried above a
perforated plate by rising hot gases.
Emissions and Controls
Particulates in the form of coal dust constitute the major air pollution
problem from coal cleaning plants. The crushing, screening, or sizing of coal
are minor sources of dust emissions; the major sources are the thermal dryers.
The range of concentration, quantity, and particle size of emissions depends upon
the type of collection equipment used to reduce particulate emissions from the
dryer stack. Emission factors for coal-cleaning plants are shown in Table 8-9.
Footnote b of the table lists various types of control equipment and their possible
efficiencies, • "" ;
Table.8-9. PARTICULATE EMISSION FACTORS
FOR THERMAL COAL DRYERS3
EMISSION FACTOR RATING: B
Type of dryer
Fluidized bedc
Flashc
Multilouvered^
Uncontrolled emissions^
Ib/ton
20
16
25
kg/MT
10
8
12.5
Emission factors expressed' as units per unit
weight of coal dried.
Typical collection efficiencies are: cyclone
collectors (product recovery) - 70 percent;
multiple cyclones (product recovery) - 85
percent; water sprays following cyclones -
95 percent; and wet scrubber following
cyclones - 99 to 99.9 percent."
cReferences 34 and 35,
Reference 36.
CONCRETE BATCHING
Process Description^, 37, 38
Concrete batching involves the proportioning of sand, gravel, and cement
by means of weight hoppers and conveyors into a mixing receiver such as a transit
mix truck. The required amount'of water is also discharged into the receiver
along with the dry materials. In some cases, the concrete is prepared for on-site
building construction work or for the manufacture of concrete products such as
pipes and pre-fabricated construction parts.
Emissions and Controls8
Particulate emissions consist primarily of cement dust, but some sand and
aggregate gravel dust emissions do occur during batching operations. There is
8-10 E 1SSIO FACTORS 2/72
-------
also a potential for dust emissions during the unloading and conveying of concrete
and aggregates at these plants and during the loading of dry-batched concrete mix,
Another source of dust emissions is the traffic of heavy equipment over unpaved or
dusty surfaces in and around the concrete batching plant,
Control techniques include the enclosure of dumping and loading areas, the
enclosure of conveyors and elevators, filters on storage bin vents, and the use iof
water sprays. Table 8-10 presents emission factors for concrete batch plants.
Table 8-10. PARTICULATE EMISSION FACTORS
FOR CONCRETE BATCHING9
EMISSION FACTOR RATING: C
Concrete
batching*3
Uncontrolled
Good control
Emissions
lb/yd3 of
concrete
0,2
0.02
kg/m^ of
concrete
0.12
0.012
aOne cubic yard of concrete weighs 4,000
pounds (1 m3 = 2,400 kg). The cement
content varies with the type of concrete
mixed, but 735 pounds of cement per yard
(436 kg/m3) may be used as a typical
value.
^Reference 28.
FIBER GLASS MANUFACTURING
Process Description8
Fiber glass is manufactured by melting various raw materials to form glass,
drawing the molten glass into fibers, and coating the fibers with an organic
material. The glass-forming reaction takes place at 2800° F (1540° C) in a large,
rectangular, gas- or oil-fired reverberatory furnace. These melting furnaces
are equipped with either regenerative or recuperative heat-recovery systems.
After being refined, the molten glass passes to a forehearth where the glass is
either formed into marbles for subsequent remelting or passed directly through
orifices to form a filament. The continuous filaments are treated with organic
binder material, wound, spooled, and sent to a high-humidity curing area where
the binder sets. The product is then cooled by blowing air over it.
Emissions a d Co trols8
The major emissions from fiber glass manufacturing processes are partieu-
lates from the glass-melting furnace, the forming line, the curing oven, and the
product cooling line. In addition, gaseous organic emissions occur from the form-
ing line and curing oven. Particulate emissions from the glass-melting furnace
are affected by basic furnace design, type of fuel (oil or gas), raw material size
and composition, and type and volume of the furnace heat-recovery system. "
Regenerative heat-recovery systems generally allow more particulate matter to
escape than do recuperative systems. Control systems are not generally used «>n
the glass-melting furnace. Organic and particulate emissions from the forming
2/72 Mineral Products industry 8-11
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line are most affected by the composition and quantity of the binder and by the
spraying techniques used to coat the fibers; very fine spray and volatile binders
increase emissions. Emissions from the curing oven are affected by the oven
temperature and binder composition, but direct-fir-ed afterburners with heat ex-
changers may be used to control these emissions. Particulate emission factors
for fiber glass manufacturing are summarized in Table 8-11,
Table 8-11. PARTICULATE EMISSION FACTORS FOR FIBER GLASS
MANUFACTURING WITHOUT CONTROLS3
EHISSION FACTOR RATING: C
Type of process
Glass furnacecjd
Reverberatory
With regenerative heat exchanger
With recuperative heat exchanger
Electric induction
Forming line6
Curing ovenf
Emissions"
Ib/ton
3
1
Neg
50
7
kg/MT
1.5
0,5
Neg
25
3.5
Emission factors expressed as units per unit of weight of
material processed
^Overall emissions may be reduced by approximately 50 percent by
using: (1) an afterburner on the curing oven, (2) a filtration
system on the product cooling, and (3) process modifications
for the forming line.
cQnly one type is usually used at any one plant.
dReferences 40 and 41.
References 40 and 42,
fReferences 42 and 43.
FRIT MANUFACTURING
Process Description44' 45
Frit is used in enameling iron and steel and in glazing porcelain and pottery.
In a typical plant, the raw materials consist of a combination of materials such as
borax, feldspar, sodium fluoride or fluorspar, soda ash, zinc oxide, litharge,
silica, boric acid, and zircon. Frit is prepared by fusing these various minerals
in a smelter, and the molten material is then quenched with air or water. This
quenching operation causes the melt to solidify rapidly and shatter into numerous
small glass particles, called frit. After a drying process, the frit is finely
ground in a ball mill where other materials are added,
Emissions and Controls45
Significant dust and fume emissions are created by the frit-smelting opera-
tion. These emissions consist primarily of condensed metallic oxide fumes that
have volatilized from the molten charge. They also contain mineral dust carry-
over and sometimes hydrogen fluoride. Emissions can be reduced by not rotating
8-12
EMISSION FACTORS
2/72
-------
the smelter too rapidly (to prevent excessive dust carry-over) and by not heating
the batch too rapidly or too long (to prevent volatilizing the more fusible elements).
The two most feasible control devices for frit smelters are baghouses and
venturi water scrubbers. Emission factors for frit smelters are shown in
Table 8-12. Collection efficiencies obtainable for venturi scrubbers are also
shown in the table.
Table 8-12. EMISSION FACTORS FOR FRIT SMELTERS
WITHOUT CONTROLS3
EMISSION FACTOR RATING: C
Type of
furnace
Rotary
Particulates^
Ib/ton
16
kg/KT
8
Fluorides^
Ib/ton
5
kg/MT
2.5
Reference 45. Emission factors expressed as units per unit
weight of charge.
^A venturi scrubber with a 21-inch (535-mm) water-gauge pres-
sure drop can reduce particulate emissions by 67 percent and
fluorides by 94 percent.
GLASS MANUFACTURING
Process Description37' 4&
Nearly all glass produced commercially is one of five basic types: soda-
lime, lead, fused silica, borosilicate, and 96 percent silica. Of these, the mod-
ern soda-lime glass constitutes 90 percent of the total glass produced and •will
thus be the only type discussed in this section. Soda-lime glass is produced on a
massive scale in large, direct-fired, continuous-melting furnaces in which the
blended raw materials are melted at 2700° F (1480° C) to form glass.
Emissions and Controls4^, 47
Emissions from the glass-melting operation consist primarily of particu-
lates and fluorides, if fluoride-containing fluxes are used in the process. Because
the dust emissions contain particles that are only a few microns in diameter,
cyclones and centrifugal scrubbers are not as effective as baghouses or filters
in collecting particulate matter. Table 8-13 summarizes the emission factors for
glass melting.
Table 8-13. EMISSION FACTORS FOR GLASS MELTING
EMISSION FACTOR RATING: D
Type of
glass
Soda-1 ime
Particulatesa
Ib/ton
2
kg/MT
1
Fluorides'5
Ib/ton
4FC
kg/MT
2FC
^Reference 48. Emission factors expressed as units per unit
weight of glass produced.
"Reference 17.
CF equals weight percent of fluoride in input to furnace;
e.g., if fluoride content is 5 percent, the emission factor
would be 4F or 20 (2F or 10).
2/72
Mineral Products Industry
8-13
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GYPSUM MANUFACTURING
Process Description8
Gypsum, or hydrated calcium sulfate, is a naturally occurring mineral that
is an important building material. When heated gypsum loses its water of hydra-
tion, it becomes plaster of paris, or when blended with fillers it serves as wall
plaster. In both cases the material hardens as water reacts with, it to form the
solid crystalline hydrate, '> "
The usual method of calcination of gypsum consists of grinding the mineral
and placing it in large, externally heated calciners. Complete calcination of 1
ton (0, 907 MT) of plaster takes about 3 hours and requires about 1. 0 million Btu
(0. E5 million kcal). 51- 52
Emissions 8
The process of calcining gypsum appears to be devoid of any air pollutants
because it involves simply the relatively low-temperature removal of the water
of hydration. However, the gases created by the release of the water of crystal-
lization carry gypsum rock dust and partially calcined gypsum dust into the atmos-
phere, " In addition, dust emissions occur from the grinding of the gypsum be-
fore calcining and from the mixing of the calcined gypsum with filler. Table 8-14
presents emission factors for gypsum processing.
Table 8-14. PARTICIPATE EMISSION FACTORS FOR GYPSUM PROCESSING3
FACTOR RATING: C
Type of process
Raw-material dryer
(if used)
Primary grinder
Calciner
Conveying
Uncontrolled
emissions
Ib/ton
40
1
90
0.7
kg/MT
20
0.5
45
0.35
With
fabric filter
Ib/ton
0,2
0,001
0.1
0,001
kg/MT .
0.1
0.0005
0.05
0.0005
With cyclone and
electrostatic
preci pita tor
Ib/ton
0.4
-
-
-
kg/MT
0.2
-
-
-
Reference 54. Emission factors expressed as units per unit weight of process
throughput.
LIME MANUFACTURING
General 8
Lime (CaO) is the high-temperature product of the calcination of limestone
(CaCO ). Lime is manufactured in vertical or rotary kilns fired by coal, oil, or
natural gas.
Emissions and Controls 8
Atmospheric emissions in the lime manufacturing industry include particu-
late emissions from the mining, handling, crushing, screening, and calcining of
the limestone and combustion products from the kilns. The vertical kilns, be-
cause of a larger size of charge material, lower air velocities, and less agitation,
8-14
E ISSIO FACTORS
2/72
-------
nave considerably fewer particulate emissions. Control of emissions from these
vertical kilns is accomplished by sealing the exit of the kiln and exhausting the
gases through control equipment,
Particulate emission problems are much greater on the rotary kilns because
of the smaller size of the charge material, the higher rate of fuel consumption,
and the greater air velocities through the rotary chamber. Methods of control
on rotary-kiln plants include simple and multiple cyclones, wet scrubbers, bag-
houses, and electrostatic precipitators. 55 Emission factors for lime manufactur-
ing are summarized in Table 8-15.
Table 8-15. PARTICULATE EMISSION FACTORS
FOR LIME MANUFACTURING WITHOUT CONTROLS3
EMISSION FACTOR RATING: B
Operation
Crushing0
Primary
Secondary
Calcining"
Vertical kiln
Rotary kiln
Emissions'3
Ib/ton
31
2
8
200
kg/MT
15.5
1
4
100
Emission factors expressed as units per unit
weight of lime processed.
Cyclones could reduce these factors by about
70 percent. Venturi scrubbers could reduce
these factors by about 95 to 99 percent.
Fabric filters could reduce these factors by
about 99 percent.
Reference 56
dReferences 55, 57, and 58.
MINERAL WOOL MANUFACTURING
Process Description59, 60
The product mineral •wool used to be divided into three categories: slag
•wool, rock wool, and glass wool. Today, however, straight slag wool and rock
•wool as such are no longer manufactured. A combination of slag and rock con-
stitutes the charge material that now yields a product classified as a mineral
wool, used mainly for thermal and acoustical insulation.
Mineral wool is made primarily in cupola furnaces charged with blast-
furnace slag, silica rock, and coke. The charge is heated to a molten state at
about 3000° F (1650° C) and then fed to a blow chamber, where steam atomizes
the molten rock into globules that develop long fibrous tails as they are drawn to
the other end of the chamber. The •wool blanket formed is next conveyed to an
oven to cure the binding agent and then to a cooler.
Emissions and Controls
The major source of emissions is the cupola or furnace stack. Its discharge
consists primarily of condensed fumes that have volatilized from the molten
2/72 Mineral Products Industry 8-15
-------
charge and gases such as sulfur oxides and fluorides. Minor sources of particu-
late emissions include the blowchamber, curing oven, and cooler. Emission
factors for various stages of mineral wool processing are shown in Table 8-16,
The effect of control devices on emissions is shown in footnotes to the table.
Table 8-16. EMISSION FACTORS FOR MINERAL WOOL PROCESSING
WITHOUT CONTROLS*
EMISSION FACTOR RATING: C
Type of process
Cupola
Reverberatory furnace
Blow chamber'3
Curing ovenc
Cooler
Particul.ates
Ib/ton
22
5
17
4 .
2
kg/MT
11
2.5
8.5
2
1
Sulfur oxides
Ib/ton
0.02
Neg
Meg
Neg
Neg
kg/MT
0.01
Neg
Neg
Neg
Neg
Reference 60, Emission factors expressed as units per unit
weight of charge.
A centrifugal water scrubber can reduce particulate emissions
by 60 percent.
"A direct-flame afterburner can reduce particulate emissions by
50 percent.
PERLITE MANUFACTURING
Process Description 61,62
Perlite is a glassy volcanic rock consisting of oxides of silicon and alumi-
num combined as a natural glass by water of hydration. By a process called ex-
foliation, the material is rapidly heated to release water of hydration and thus to
expand the spherules into low-density particles used primarily as aggregate in
plaster and concrete. A plant for the expansion of perlite consists of ore unload-
ing and storage facilities, a furnace -feeding device, an expanding furnace, pro-
visions for gas and product cooling, and product-classifying and product-collect-
ing equipment. Vertical furnaces, horizontal stationary furnaces, and horizontal
rotary furnaces are used for the exfoliation of perlite, although the vertical types
are the most numerous. Cyclone separators are used to collect the product.
Emissions and Controls 6 2 .
A fine dust is emitted from the outlet of the last product collector in a per-
lite expansion plant. The fineness of the dust varies from one plant to another,
depending upon the desired product. In order to achieve complete control of these
particulate emissions, a baghouse is needed. Simple cyclones and small multiple
cyclones are not adequate for collecting the fine dust from perlite furnaces. .Table
8-17 summarizes the emissions from perlite manufacturing.
8-16
EMISSION FACTORS
2/72
-------
Table 8-17. PARTICULATE EMISSION FACTORS
FOR PERLITE EXPANSION FURNACES
WITHOUT CONTROLS8
EMISSION FACTOR RATING: C
Type of
furnace
Vertical
Emissions^
"Ib/ton
21
kg/MT
10.5
a
Reference 63. Emission factors expressed as
units per unit weight of charge.
Primary cyclones will collect 80 percent of
the particulates above 20 microns, and bag-
housts will collect 96 percent of the par-
ticles above 20 microns.62
PHOSPHATE ROCK PROCESSING
Process Description64
Phosphate rock preparation involves beneficiation to remove impurities, ;
drying to remove moisture, and grinding to improve reactivity. Usually, direct-
fired rotary kilns are used to dry phosphate rock. These dryers burn natural
gas or fuel oil and are fired counter-currently. The material from the dryers
may be ground before storage in large storage silos. Air-swept ball mills are
preferred for grinding phosphate rock.
Emissions and Controls 64
Although there are no significant emissions from phosphate rock benefici-
ation plants, emissions in the form of fine rock dust may be expected from drying
and grinding operations. Phosphate rock dryers are usually equipped with dry
cyclones followed by wet scrubbers. Particulate emissions are usually higher
when drying pebble rock than when drying concentrate because of the small adher-
ent particles of clay and slime on the rock. Phosphate rock grinders can be &•
considerable source of particulates. Because of the extremely fine particle size,
baghouse collectors are normally used to reduce emissions. Emission factors
for phosphate rock processing are presented in Table 8-18.
STONE QUARRYING AND PROCESSING
Process Descriptions
Rock and gravel products are loosened by drilling and blasting them from
their deposit beds, and they are removed with the use of heavy earth-moving
equipment. This mining of rock is done primarily in open pits. The use of
pneumatic drilling and cutting, as well as blasting and transferring, causes con-
siderable dust formation. Further processing includes crushing, regrinding, and
removal of fines. «9 Dust emissions can occur from all of these operations, as
well as from quarrying, transferring, loading, and storage operations. Drying
operations, -when used, can also be a source of dust emissions.
2/72 Mineral Products Industry 8-17
-------
Emissions8
Table 8-18. PARTICIPATE EMISSION FACTORS FOR PHOSPHATE ROCK
PROCESSING WITHOUT CONTROLS9
EMISSION FACTOR RATING: C
Type of source
Dryingb.c
Grindingb.d
Transfer and storage^ »e
Open storage piles^
Emissions
Ib/ton kg/MT
15
20
2
40
7.5
10
1
20
Emission factors expressed as units per unit weight of
phosphate rock.
^References 65 through 67.
"Dry cyclones foTIowid by wet scrubbers can reduce emis-
sions by 95 to 99 percent.
Dry cyclones followed by fabric filters can reduce
emissions by 99,5 to 99,9 percent.
Reference 66,
Reference 68.
As enumerated above, dust emissions occur from many operations in stone
quarrying and processing. Although a big portion of these emissions is heavy
particles that settle out within the plant, an attempt has been made to estimate the
suspended particulates. These emission factors are shown in Table 8-19. Factors
affecting emissions include the amount of rock processed; the method of transfer
of the rock; the moisture content of the raw material; the degree of enclosure of
the transferring, processing, and storage areas; and the degree to which control
equipment is used on the processes.
8-18
E ISSIO FACTORS
2/72
-------
Table 8-19. PARTICULATE EMISSION FACTORS FOR ROCK-HANDLING PROCESSES
EMISSION FACTOR RATING: C
Type of process
Crushing operations^'0
Primary crushing
Secondary crushing
and screening
Tertiary crushing
and screening (if used)
Recrushing and screening
Fines mill
Miscellaneous operations0'
Screening, conveying,
and handling6
Storage pile losses^
Uncontrolled
total3
Ib/ton kg/MT
0.5 0.25
1.5 0.75
6 3
5 2.5
6 3
2 1
10 5
Settled out
in plant,
%
80
60
40
50
25
Suspended
emission
Ib/ton
0.1
0.6
3.6
2.5
4.5
kg/MT
0.05
0.3
1.8
1.25
2.25
Typical collection efficiencies: cyclone, 70 to 85 percent; fabric filter,
99 percent.
All values are based on raw material entering primary crusher, except those
for recrushing and screening, which are based on throughput for that operation.
Reference 70.
Based on units of stored product.
Reference 71.
The significance o.f storage pile losses is mentioned in Reference 72. The
factor assigned here is the author's estimate for uncontrolled total emissions.
Use of this factor should be tempered with knowledge about the size of materials
stored, the local meteorological factors, the frequency with which the piles
are disturbed, etc.
REFERENCES FOR CHAPTER 8
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PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-4Z. 1968. p. 34-35.
2, Danielson, J.A. and R,S, Brown, Jr. Hot-Mix Asphalt Paving Batch Plants.
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Ohio. May 1959.
2/72
Mineral Products Industry
8^19
-------
5, Danielson, J.A, - Unpublished test data from asphalt batching plants of the
Los Angeles County Air Pollution Control District. Presented at Air Pollu-
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California, November 1966.
.6. Sallee, G. Private communication on particulate pollutant study, Midwest
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Costs for Selected Industries and Selected Regions. Research Triangle
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Hydrocarbon Emissions from Selected Industrial Processes. Air Pollution
Control Assoc. j_5:306-312, July 1965.
10. Weiss, S,M, Asphalt Roofing Felt-Saturatorg. In: Air Pollution Engineering
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Pollution Control. Cincinnati, Ohio. Publication No. 999-AP-40. 1967.
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11. Goldfield, J. andR.G. McAnlis. Low-Voltage Electrostatic Precipitators to
Collect Oil Miets from Roofing-Felt Asphalt Saturators and Stills. J. Industrial
Hygiene Assoc. July-August 1963,
12. Shreve, R.N. Chemical Process Industries. 3rd Ed, New York. McGraw-
Hill Book Company, 1967. p. 151-158.
13. Havighorst, C.R. and S. L, Swift, The Manufacturing of Basic Refractories.
Chem. Eng. 72_:98-10Q, August 16, 1965.
14. Norton, F.H. Refractories. 3rd Ed. New York, McGraw-Hill Book Com-
pany, 1949. p. 252.
15. Marks, L.S, (ed. ). Mechanical Engineer's Handbook. 5th Ed. New York,
McGraw-Hill Book Company, 1951. p. 523, 535.
16. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-42. 1968. p, 6-7.
17, Semrau, K. T. Emissions of Fluorides from Industrial Processes: A Review.
J. Air Pollution Control Assoc. _7_(2);92-108, August 1957. • ' '
18. Duprey, R. L. Compilation of Air Pollutant Emission Factors, U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-42. 1968, . p. 34-35.
8-20 E ISS10 FACTORS 2/72
-------
19. Carbide. Kirk-Othmer Encyclopedia of Chemical Technology. 1964.
20. The Louisville Air Pollution Study. U.S. DHEW, PHS, Robert A. Taft
Sanitary Engineering Center. Cincinnati, Ohio. 1961.
21. Brown, R.W. andK.H. Sandmeyer, Applications of Fused-Cast Refractories.
Chem. Eng. 7_6_:106-114, June 16, 1969.
22. Shreve, R.N. Chemical Process Industries. 3rd Ed. New York, McGraw-
Hill Book Company, 1967. p. 158.
23. Unpublished data provided by a Corhart Refractory. Kentucky Department of
Health, Air Pollution Control Commission. Frankfort, Kentucky. September
1969.
24. Unpublished stack test data on refractories. Resources Research,
Incorporated . Reston, Virginia. 1969.
25. Unpublished stack test data on refractories. Resources Research,
Incorporated. Reston, Virginia. 1967.
26. Kreichelt, T.E., D. A. Kemnitz, and S. T. Cuffe. Atmospheric Emissions
from the Manufacture of Portland Cement. U.S. DHEW, PHS, Bureau of
Disease Prevention and Environmental Control. Cincinnati, Ohio. Publica-
tion No, 999-AP-17. 1967.
27. Duprey, R.L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C, PHS
Publication No. 999-AP-42. 1968. p. 35.
28. Allen, G, L. et al. Control of Metallurgical and Mineral Dusts and Fumes in
Los Angeles County. Bureau of Mines, Washington, D. C. Information
Circular No. 7627. April 1952.
29. Private Communication between Resources Research, Incorporated, Reston,
Virginia, and the State of New Jersey Air Pollution Control Program,
Trenton, New Jersey. July 20, 1969.
30. Henn, J, J. et al. Methods for Producing Alumina from Clay: An Evaluation
of Two Lime Sinter Processes. Bureau of Mines. Washington, D.C. Report^
of Investigations No. 7299. September 1969.
31. Peters, F.A. et al. Methods for Producing Alumina from Clay: An
Evaluation of the Lime-Soda Sinter Process. Bureau of Mines. Washington,
D.C. Report of Investigation No. 6927. 1967.
32. Communication between Resources Research, Incorporated, Reston, Virginia,
and a clay sintering firm. October 2, 1969.
33. Communication between Resources Research, Incorporated, Reston, Virginia,
and an anonymous Air Pollution Control Agency. October 16, 1969.
2/72 Mineral Products Industry 8-21
-------
34. Unpublished stack test results on thermal coal dryers. Pennsylvania
Department of Health, Bureau of Air Pollution Control. Harrisburg, Pa.
35. Am-herst's Answer to Air Pollution Laws.. Coal Mining and Processing.
p. 26-29. February 1970.
36, JoneSj D, W. Dust Collection at Moss. No. 3. Mining Congress Journal,
5_5(7):53-56, July 1969.
37. Vincent, E. J. andJ.L,. McGinnity. Concrete Batching Plants. In: Air
Pollution Engineering Manual. Danielson, J.A, (ed.). 'U.S. DHEW, PHS,
National Center for Air Pollution Control. Cincinnati, Ohio, PHS Publica-
tion No. 999-AP-40. 1967. p. 334-335.
38. Communication between Resources Research, Incorporated, Reston, Virginia,
and the National Ready-Mix Concrete Association. September 1969,
39. Netzley, A. B. and J.L. McGinnity. Chemical Processing Equipment. In;
Air Pollution Engineering Mamial, Danielson, J.A, (ed. ). U.S. DHEW, PHS,
National Center for Air Pollution Control, Cincinnati, Ohio. PHS Publica-
tion No. 999-AP-4G. 1967. p. 724-733.
40. Communication between Resources Research, Incorporated, Reston, Virginia,
and a fiber glass company. October 1969.
41. Kansas City Air Pollution Abatement Activity. U.S. DHEW, PHS, National
Center for Air Pollution Control. Cincinnati, Ohio. Jamiary 1967. p. 53,
42. Communication between Resources Research, Incorporated, Reston, Virginia,
and New Jersey State Department of Health, Trenton, N. J, July 1969.
43. Spinks, J. L. Mechanical Equipment. In: Air Pollution Engineering Manual.
Danielson, J.A. (ed. ). U.S. DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio. PHS Publication No. 999-AP-40. 1967. p. 342.
44. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-42, 1968. p. 37-38.
45. Spinks, J.L.. Frit Smelters. In: Air Pollution Engineering Manual.
Danielson, J.A. (ed. ). U. S. DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio. PHS Publication No. 999-AP-40. 1967. p. 738-
744.
46. Duprey, R.L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control, Durham, N. C. PHS
Publication No. 999-AP-42. 1968. p. 38.
47. Netzley, A, B. and J. L. McGinnity. Glass Manufacture. In: Air Pollution
Engineering Manual. Danielson, J.A. (ed.), U.S. DHEW, PHS, National
Center for Air Pollution Control. Cincinnati, Ohio. PHS Publication No.
999-AP-40. 1967. p. 720-730,
8-22 E ISSIO FACTORS 2/72
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48. Technical Progress Report: Control of Stationary Sources, Los Angeles
County Air Pollution Control District, 1_, April i960, !
49. Shreve, R. N. Chemical Process Industries. 3rd Ed. New York, McGraw-
Hill Book Company, 1967. p. 180-182.
50. Havinghorst, R. A Quick Look at Gypsum Manufacture. Chem. Eng.
72_:52-54, January 4, 1965.
51. Work, Li. T, and A.L, Stern. Size Reduction and Size Enlargement, In:
Chemical Engineers Handbook. 4th Ed, New York, McGraw-Hill Book
Company. 1963. p. 51.
52, Private communication on emissions .from gypsum plants between M.M.
Hambuik and the National Gypsum Association, Chicago, Illinois. January
1970.
53. Culhane, F.R. Chem. Eng. Progr. 64.:72, January 1, 1968.
54. Communication between Resources Research, Incorporated, Reston, Virginia,
and the Maryland State Department of Health, Baltimore, Maryland.
November 1969.
55. Lewis, C. and B, Crocker. The Lime Industry's Problem of Airborne Dust.
Air Pollution Control Assoc. l_9;31-39, January 1969.
56. State of Maryland Emission Inventory Data. Maryland State Department of
Health, Baltimore, Maryland. 1969.
57. A Study of the Lime Industry in the State of Missouri for the Air Conservation
Commission of the State of Missouri, Reston, Virginia, Resources Research,
Incorporated. December 1967. p. 54.
58. Communication between Midwest Research Institute and a control device
manufacturer. 1968.
59. Duprey, R. L. Compilation of Air Pollutant Emission Factors. U.S. DHEJW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-42. 1968. p. 39-40.
60. Spinks, J.L. Mineral Wool Furnaces, In: Air Pollution Engineering Manual.
Danielson, J.A. (ed. ). U.S. DHEW, PHS, National Center for Air Pollution
Control. Cincinnati, Ohio. PHS Publication No. 999-AP-40. 1967.
p. 343-347.
61. Duprey, R, L. Compilation of Air Pollutant Emission Factors. U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS
Publication No. 999-AP-42. 1968, p. 39.
62. Vincent, E. J, Per lite-Expanding Furnaces, In: Air Pollution Engineering
Manual. Danielson, J.A. (ed. ). U.S. DHEW, PHS, National Center for
2/72 Mineral Products Industry i8-23
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Air Pollution Control. Cincinnati, Ohio. .PHS Publication No. 999-AP-40.
1967. p. 350-352. .
63. Sableski, J. J. Unpublished data on perlite expansion furnace. National
Center for Air Pollution Control. Cincinnati, Ohio, July 1967.
64. Stern, A. (ed. )• ^ir Pollution, Volume III, Sources of Air Pollution and
Their Control, 2nd Ed. , New York, Academic Press, 1968, p. 221-222.
65. Unpublished data from -phosphate rock preparation plants in Florida. Mid-
west Research Institute. June 19*70.
66. Control Techniques for Fluoride Emissions. Internal document. U, S, Environ-
mental Protection Agency, Office of Air Programs, Durham, N. C. p. 4-46.
67. Control Techniques for Fluoride Emissions. Internal document. U, S, Environ-
mental Protection Agency, Office of Air Programs, Durham, N. C. p, 4-36.
68, Control Techniques for' Fluoride Emissions. Internal document, U, S. Environ-
mental Protection Agency, Office of Air Programs, Durham, N. C, p, 4-34,
69. Communication between Resources Research, Incorporated, Reston, Virginia,
and the National Crushed Stone Association. September 1969.
70. Culver, P. Memorandum to files. U.S. DHEW, PHS, National Air Pollution
' Control Administration, Division of Abatement. January 6, 1968.
71. Sableski, J, J. Unpublished data on storage and handling of rock products.
..U. S. DHEW, PHS, National Air Pollution Control Administration, Division of
Abatement. May 1967.
72. Stern A, (ed.). Air Pollution, Volume III, Sources of Air Pollution and Their
Control. 2nd Ed. , New York, Academic Press, 1968. p. 123-127.
8-24 E ISSIO FACTORS 2/72
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9. PETROLEUM INDUSTRY
PETROLEUM REFINERY
General *
Although a modern refinery is a complex system of many processes, the
entire operation can be divided into four major steps; separating, converting,
treating, and blending. The crude oil is first separated into selected fractions
(e.g., gasoline, kerosene, fuel oil, etc.). Because the relative volumes of each
fraction produced by merely separating the crude may not conform to the relative
demand for each fraction, some of the less valuable products, such as heavy
naphtha, are converted to products with a greater sale value, such as gasoline.
This is done by splitting, uniting, or rearranging the original molecules. The
final step is the blending of the refined base stocks with each other and with
various additives to meet final product specifications. The various unit operations
involved at petroleum refineries will be briefly discussed in the following sections.
Crude Oil Distillation - Because crude oil is composed of hydrocarbons of differ-
ent physical properties, it can be separated by physical means into its various
constituents. The primary separation is usually accomplished by distillation.
The fractions from the distillation include refinery gas, gasoline, kerosene, light
fuel oil, diesel oils, gas oil, lube distillate, and heavy bottoms. These "straight-
run products" are treated to remove impurities and used as base stocks or feed-
stock for other refinery units, or sold as finished products.
Catalytic Cracking - To obtain the desired product distribution and quality, heavy
hydrocarbon molecules are cracked or split to form low-boiling hydrocarbons in
the gasoline range. Catalytic cracking units are classified according to the method
used for catalyst transfer. The two most widely used methods are the moving-bed,
typified by the Thermofor catalytic cracking units (TCC), and the fluidized bed,
system of fluid catalytic cracking units (FCC).
In a typical "cat" cracker, the catalyst in the form of a fine powder for an
FCC unit and beads or pellets for a TCC unit, passes through the reactor, then
through a regeneration zone where coke deposited on the catalyst is burned off in
a continuous process,
Catalytic Reforming - Unlike catalytic cracking, catalytic reforming does not
increase the gasoline yield from a barrel of crude oil. Reforming uses gasoline
as a feedstock and by molecular rearrangement, which usually includes hydrogen
removal, produces a gasoline of higher quality and octane number. Coke deposi-
tion is not severe in reforming operations, and thus catalyst regeneration is not
always used. If this is the case, the catalyst is physically removed and replaced
periodically. Some of the fixed-bed catalytic reforming processes that require
catalyst regeneration include Fixed-Bed Hydroforming, Ultraforming, and Power-
forming, Some of the fixed-bed processes in which the catalyst is infrequently
2/72 9-1
-------
regenerated include Platforming, Rexforming, and Catforming,
Polymerization, Alkylation, Isomerization-'' - Polymerization and alkylation are
processes used to produce gasoline from the gaseous hydrocarbons formed during
cracking operations. Polymerization joins two or more olefins, and alkylation
unites an olefin and an isoparaffin. In the process of isomerization, the arrange-
ment of the atoms in a molecule is altered, usually to form branched-chain hydro-
carbons.
Treating, Blending - The products from both the separation and the conversion
steps are treated, usually for the removal of sulfur compounds and gum-forming
materials. As a final step, the refined base stocks are blended with each other
and with •various additives to meet product specifications.
Emissions 1
Emissions from refineries vary greatly in both quantity and type. The most
important factors affecting refinery emissions are crude oil capacity, air pollution
control equipment useds general level of maintenance, and processing scheme
used. The major pollutants emitted are sulfur oxides, nitrogen oxides, hydro-
carbons, carbon monoxide, and malodorous materials. Other emissions of lesser
importance include particulates, aldehydes, ammonia, and organic acids. Boilers,
process heaters, and catalytic cracking unit regenerators; are major sources of
sulfur oxides, nitrogen oxides, and particulates. The catalytic cracking unit
regenerators are also large sources of carbon monoxide, aldehydes, and ammonia,
The many hydrocarbon sources include waste-water separators, blow-down
systems, catalyst regenerators, pumps, valves, cooling .towers, vacuum jets,
compressor engines, process heaters, and boilers. Emission factors for the
various refinery operations are summarized in Table 9-1.
REFERENCE FOR CHAPTER 9
1, Atmospheric Emissions from Petroleum Refineries: A Guide for Measurement
and Control. U.S. DHEW, PHS, Publication No. 763. I960,
9-2 EMISSION FACTORS 2/72
-------
[\J
ro
Table 9-1. EMISSION FACTORS FOR PETROLEUM REFINERIES9
B
to
3
CD
to
i
CO
Type of process
Boilers and process heaters
lb/103 bbl oil burned
kg/103 liters oil burned
lb/103 ft3 gas burned
kg/103 m3 gas burned
Fluid catalytic cracking units (FCC)
lb/103 bbl fresh feed
kg/103 liters fresh feed
Moving-bed catalytic cracking
ynits (TCC)
lb/103 bbl fresh feed
kg/103 liters fresh feed
Co pressor internal combustion
engines
lb/103 ft3 gas burned
kg/103 m3 gas burned
Blowdown systems
lb/103 bbl refinery capacity
With control
Without control
kg/103 liters refinery capacity
With control
Without control
Particulates
840
2.4
0.02
0.32
61
0.175
17
0.049
-
-
-
-
-
-
Sulfur
oxides
NAb
MA
NA
NA
125
1.5
60
0.171
-
-
-
-
-
Carbon
monoxide
Neg
Neg
Neg
Neg
13,700
39.2
3,800;
10.8
Neg
Neg -
-
_
-
-
Hydrocarbons
140
0.4
0.03
0.48
220
0.630
87
0.250
1.2
19.3
5
300
0.014
0.860
N i trogen
oxides
2,900
8.3
0.23
3.7
§3
0.180
5
0.014
0.9
14.4
-
_
-
-
Aldehydes
25
0.071
0.003
0.048
19
0.054
12
0.034
0.1
1.61
-
_
-"
-
Ammonia
_
-
_
-
54
0.155
6
0.017
0.2
3.2
-
m
-
-
-------
Jable 9-1 (continued). EMISSION FACTORS FOR
PETROLEUM REFINERIES*
B
Type of process
Process drains
lb/!Q3 bbl waste water
With control
Without control
kg/ltP liters waste water
With control
Without control
Vacuum jets
Ib/I03 bbl vacuum distillation
With control
Without control
kg/10^ liters vacuum distillation
With control
Without control
Cooling tower
lb/10^ gal cooling water
kg/10** liters cooling water
Miscellaneous losses, Ib/lO^ bbl
refinery capacityc
Pipeline valves and flanges
Vessel relief valves
Pu p seals
Co pressor seals
Others (air blowing, sampling, etc)
Particulates
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
Sul fur
oxides
-
_
-
-
-
-
-
-
- .
-
-
-
-
-
Carbon
monoxide
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
Hydrocarbons
8
210
0.023
0.600
Neg
130
Neg
0.370
6
0.72
28 (0.080)
11 (0.031)
17 (0.049)
5 (0.014)
10 (0,029)
Nitrogen
oxides
-
-
-
-
-
-
-
—
-
-
-
_
-
Aldehydes
-
_
-
-
-
.
-
-
-
-
-
-
-
-
-
Ammonia
-
.
-
-
-
-
-
-
-
-
-
-
-
-
-
CO
O
-n
O
O
yss
fSJ
—i
Reference 1.
NA = information not available.
kg/103 liters shown in parentheses.
-------
10. WOOD PROCESSING
Wood processing involves the conversion of raw wood to either pulp or pulp-
board. This section presents emission data both for wood pulping operations and
for the manufacture of two types of pulpboard: paperboard and fiber board. The
burning of wood waste in boilers and conical burners is not included as it is
discussed in other sections of this publication.
WOOD PULPING
Generali
Wood pulping involves the production of cellulose from wood by dissolving
the lignin that binds the cellulose fiber together. The three major chemical
processes for pulp production are the kraft or sulfate process, the sulfite process,
and the neutral sulfite semichemical process. The choice of pulping process is.
determined by the product being made, by the type of wood species available, and
by economic considerations. There is a lack of valid emission data for the sulfite
and neutral sulfite semichemical processes; therefore3 only the kraft process 'will
be discussed in this section.
Process Description (Kraft Process)1 • ^
The kraft process involves the cooking of wood chips under pressure in the
presence of a cooking liquor in either a batch or continuous digester. The cooking
liquor, an aqueous solution of sodium sulfide and sodium hydroxide, dissolves the
lignin that binds the cellulose fibers tobether.
When cooking is completed, the bottom of the digester is suddenly opened,
and its contents are forced into the blow tank. Here the major portion of the
spent cooking liquor, which contains the dissolved lignin, is drained, and the 'pulp
enters 'the initial stage of washing. From the blow tank the pulp passes through
the knotter, where unreacted chunks of wood are removed. The pulp is then pro-
cessed through intermittent stages of washing and bleaching, after which it is
pressed and dried into the finished product,
Most of the chemicals from the -spent cooking liquor are recovered for re-
use in subsequent cooks. These spent chemicals and organics, called "black
liquor," are concentrated in multiple-effect evaporators and/or direct-contact
evaporators.
The concentrated black liquor is then sprayed into the recovery furnace,
where the organic content supports combustion. The inorganic compounds fall
to the bottom of the furnace and are withdrawn as a molten smelt, which is
dissolved to form a solution called "green liquor. " The green liquor is then
purnped from the smelt-dissolving tank, treated with slaked lime, and clarified.
The resulting liquor, referred to as "white liquor, " is the cooking liquor used in
the digesters.
2/72 10-1
-------
Emissions and Controls3
Particulate emissions from the kraft process occur primarily from the
recovery furnace, the lime kiln, and the smelt-dissolving tank. They are caused '
mainly by the carryover of solids plus the sublimation and condensation of
inorganic chemicals.
The characteristic kraft-mill odor is caused principally by the presence of a
variable mixture of hydrogen sulfide and dimethyl disulfide. Hydrogen sulfide is
emitted from the breakdown of the weak base, sodium sulfide, which is character-
istic of kraft cooking liquor. It may also be generated by improper operation of a
recovery furnace. Methyl mercaptan and dimethyl sulfide are formed in reactions
with the wood component lignin. Dimethyl disulfide is formed through the oxidation
of mercaptan groups derived from th:e lignins.
Sulfur dioxide emissions in the kraft process result from the oxidation of
reduced sulfur compounds. A potential source of sulfur dioxide is the recovery
boilers, where reduced sulfur gases present can be oxidized in the furnace
atmosphe re.
Potential sources of carbon monoxide emissions from the kraft process
include the recovery furnace and lime kilns. The major cause of carbon monoxide
emissions is furnace operation well above rated'capacity, making it impossible to
maintain oxidizing conditions.
Rather than presenting a lengthy discussion on the control techniques pre-
sently available for each phase of the kraft process, the most widely used controls
are shown, where applicable, in the table for emission factors. Table 10-1 presents
these emission factors for both controlled and uncontrolled sources.
PULPBOARD
General4
Pulpboard manufacturing includes the manufacture of fibrous boards from &'
pulp slurry. This includes two distinct types of product, paperboard and fiber-
board, Paperboard is a general term that describes a sheet 0. 012 inch (0. 30 mm).
or more in thickness made of fibrous material on a paper machine. * Fiberboard,
also referred to as particle board, is much thicker than paperboard and is made
somewhat differently.
There are two distinct phases in the conversion of wood to pulpboard: (1) the
manufacture of pulp from the raw wood, and (2) the manufacture of pulpboard from .
the pulp. This section deals only with the latter as the first is covered under the
section on wood pulping industry.
Process Description 4
In the manufacture of paperboard, the stock is sent through, screens into'the
head box, from which it flows onto a moving screen. Approximately 15 percent
of the water is removed by suction boxe-s located under the screen. Another 50-to-
60 percent of the moisture content is removed in the drying section. The dried
board then enters the calendar stack, which imparts the final surface to the
product.
10-2 E ISSIO FACTORS 2/72
-------
KS
"Nj
Table 10-1. FOR SULFATE PULPINGa
(unit weights of air-dried unbleached pulp)
EMISSION FACTOR RATING: A
Source
Blow tank
accumulator
Washers and screens
Multiple-effect
evaporators
Recovery boilers
and direct-contact
evaporators
Smelt dissolving
tank
Lime kilns
Turpentine condenser
Fluidi zed-bed
calciner6
Type of
control
Untreated
Untreated
Untreated
Untreated
Electrostatic
precipitators
V en tun* scrubber
Untreated
Untreated
Scrubber
Untreated
Untreated
Scrubber
Particulatesb
1 b/ton
-
-
-
Ill
15
47
2
45
4
-
72
0.7
ki/MT
-
-
-
75.5
7.5
23.5
1
22.5
2
-
36
0.35
Sulfur
dioxides (SOgr
1 b/ton
-
-
-
5.0
5.0
5,0
-
-
-
-
-
kg/HT
-
_
-
2.5
2.5
2,5
-
_
-
-
-
Carbon
monoxide0
1 b/ton
-
-
-
60
60
60
-
10
10
-
-
kg/MT
-
_
-
30
30
30
-
5
5
_
-
Hydrogen
sulfideb
1 b/ton
0.1
0.02
0.5
12
12
12
0.03
1.0
1.0
0.01
-
kg/HT
0.05
0.01
0.25
6
6
6
0.015
0,5
0.5
0.005
-
RSH, RSR,
RSSRd
1 b/ton
3.0
0.2
0.4
0.9
0.9
o.i
0.04
0.6
0.6
0.5
_
kg/MT
1.5
0.1
0.2
0.45
0.45
0.45
0.02
0.3
0.3
0.25
—
o
o
CD
For more detailed data on specific types of plants, consult Reference 1
Reference 1.
^Reference 6.
dRSH - Mercaptans, RSR - Sulfides, RSSR - Disulfides.
a
Only a few plants in the western United States use this process.
o
I
-------
In the manufacture of fiberboard, the slurry that .remains after pulping is
washed and sent to the stock chests where sizing is added. The refined fiber from
the stock chests is fed to the head box of the board machine.' The stock is.,next
fed onto the forming screens and sent to dryers, after which the dry product is
finally cut and fabricated,
Emissions4
7-9
Emissions from the paperboard machine consist only of water1 vapor, and
little or no particulate matter is emitted from the dryers. Particulates are
emitted, however, from the drying operation of fiberboard. Additional particulate
emissions occur from the cutting and sending operations, but no data were avail-
able to estimate these emissions. Emission factors for pulpboard manufacturing
are shown in Table 10-2. '
Table 10-2, PARTICULATE EMISSION
FACTORS FOR PULPBOARD MANUFACTURING
EMISSION FACTOR RATING: E
Type of product
Paperboard
Fiberboard'3
Emissions
Ib/ton
Neg
0.6
kg/MT
Neg
0.3
Emission factors expressed as units
per unit weight of finished product.
^Reference 10.
REFERENCES FOR CHAPTER 10
1. Hendrickson, E. R. et al. Control of Atmospheric Emissions in the "Wood
Pulping Industry. Vol. ' I. U.S. DHEW, PHS, National Air Pollution Control
Administration. Final report under contract No. CPA 22-69-18. March 15,
1970.
2. Duprey, R.-L. Compilation of Air Pollutant Emission Factors, U.S. DHEW,
PHS, National Center for Air Pollution Control. Durham, N. C. PHS Publi-
cation No. 999-AP-42. 1968. p. 43.
3, Hendrickson, E. R. et al. Control of.Atmospheric Emissions in the Wood
Pulping Industry. Vol. III. U. S, DHEW, PHS, National Air Pollution Control
Administration. Final report under contract No. CPA-22-69-18, Ma-rch 15,
1970, .
4, Air Pollutant Emission Factors. Final Report, Resources Research, Incor-
porated, Reston, Virginia. Prepared for National Air Pollution Control
Administration under contract No. CPA-22-69-H9.. April 1970,
5. The Dictionary of Paper, New York, American Paper and Pulp Association,
1940, .
10-4 EMISSION FACTORS 2/72
-------
6, Control Techniques for Carbon Monoxide Emissions from Stationary Sourcet.
U.S. DHEW, PHS, EHS, National Air Pollution Control Administration. j
Washington, D. C. Publication No. AP-65. March 1970. p. 4-24 through
4-25.
7, Hough, G, W. and L, J, Gross, Air Emission Control in a Modern Pulp and
Paper Mill. Amer, Paper Industry. 5_1_:36, February 1969. :
8, Pollution Control Progress. J. Air Pollution Control Assoc. _L7_:41Q, Junq
1967.
9, Private communication between I. Gellman and the National Council of the
Paper Industry for Clean Air and Stream Improvement. New York, October
28, 1969.
10. Communication between Resources Research, Inc. , Reston, Virginia, and
New Jersey State Department of Health, Trenton, New Jersey. July 1969,
2/72 Wood Processing 10-5
-------
-------
APPENDIX
2/72 A-]
-------
Table A-l. PERCENTAGE DISTRIBUTION BY SIZE OF PARTICLES FROM SELECTED
SOURCES WITHOUT CONTROL EQUIPMENT
Type of source
Stationary combustion
Bituminous coal
Pulverized
Cyclone
Stoker
Anthraeiti coal
Fuel oil
Natural gas
Solid waste disposal
Refuse incineration
Mobile combustion
Gasoline-powered motor vehicles
Diesel -powered motor vehicles
Aircraft
Chemical process
Phosphoric acid
Soap and Detergents
Sulfuric acid
Food and agriculature
Alfalfa dehydrating
Cotton ginning
Feed and grain
Fish meal
Phosphate fertilizer
Metallurgical
Primary aluminum
Primary zinc
Iron and steel
Sintering
Blast furnace
Open hearth
Basic oxygen
Bessemer converter
Secondary aluminum
Brass and bronze
Gray iron foundry
Secondary lead
Secondary steel
Secondary zinc
Mineral products
Asphalt batching
Asphalt roofing
Ceramic clay
Castable refractories
Cement
Concrete
Frit
Glass
Gypsum
Particles by size range, %
<5 vi
15
65
4
35
50
100
12
100
63
100
100
5
100
5 to 10 v
17
10
6
5
NA»
-
10
-
NA
-
-
15
-
Average size
2" to 10 v
NA
5
1
6
13
14
0
NA
46
99.5
.
34
TOO
18
95
60
100
35
100
36
100
22
13
45
26
NA
15
1
6
12
17
0
NA
22
0,5
-
30
-
8
3
14
-
25
-
NA
-
25
21
15
NA
951 <10 p
10 to 20 y
20
8
11
8
NA
-
15
-
NA
-
-
40
-
-
NA
20
3
10
12
40
0
NA
17
0
-
23
-
12
2
11
-
17
-
NA
-
25
27
15
NA
NA
20 to 44 p
23
7
18
7
NA
-
18
-
0
-
-
30
-
-
NA
45
8
8
13
NA
15
NA
10
0
100
10
-
14
0
9
-
20
-
40
-
20
25
15
NA
NA
>44 u
25
10
61
45
0
.
45
-
0
-
'
10
-
-
40
15
87
70
50
NA
85
70
5
0
-
3
-
48
0
6
-
3
-
6
-
8
14
10
0
NA
A-2
EMISSION FACTORS
2/72
-------
Table A-l (continued). PERCENTAGE DISTRIBUTION BY SIZE OF PARTICLES
FROM SELECTED SOURCES WITHOUT CONTROL EQUIPHENT
Type of source
Mineral products (continued)
Lime
Mineral wool
Perlite
Phosphate rock
Stone quarrying and processing
Crushing
Conveying and screening
Petroleum refinery
Catalyst regenerator
Wood processing
Fiberboard
Particles by size range, %
<5 v
2
0.5
32
80
5
30
50
NA
5 to 10 y
8
2.5
10
15
5
20
15
NA
10 to 20 u
24
10
10
5
5
20
NA
NA
20 to 44 v
38
27
13
0
10
18
NA
NA
>44 y
Z8
60
35
0
75
12
NA
25
NA = no further breakdown of particle distribution available.
2/72
Appendix
A-3
-------
Table A-2. NATIONWIDE EMISSIONS FOR 1968a
Source
Stationary
combustion
Solid waste
disposal
Mobile
combustion
Industrial
process
Miscellaneous
Total
Parti culates
TO6 tons/yr
8.9
1.1
1.2
7.5
9,6
28.3
ID6 MT/yr
8.1
1.0
. 1.1
6.8
8.7
25.7
Sulfur oxides
106 tons/yr
24.4
0.1
0.8
7.3
0.6
33.2
ID6 MT/yr
22.1
0.1
0.7
6.6
0.5
30.0
Carbon monoxide
TO6 tons/yr
1.9
7.8
63.8
9.7
16.9
100.1
106 HT/yr
1.7
7.1
57.9
8.8
. 15.3
90.8
Hydrocarbons
106 tons/yr
0.7
1.6
16.6
4.6
8.5
32.0
1C6 HT/yr
0.6
1.5
15.1
4.2
7.7
29.1
Nitrogen oxides
TO6 tons/yr
10.0
0.6
8.1
0.2
1.7
20.6
TO6 MT/yr
9.1
0.5
7.3
0.2
1.5
18.6
rn
TI
3>
o
—I
o
=D
CO
Reference 1.
-•j
ro
-------
Table A-3. DISTRIBUTION BY PARTICLE SIZE OF AVERAGE COLLECTION EFFICIENCIES
FOR VARIOUS PARTICULATE CONTROL EQUIPMENT3*b
Efficiency, %
Type of collector
Baffled settling chamber
Simple cyclone
Long-cone cyclone
Multiple cyclone
(12-in. diameter)
Multiple cyclone
(6-in. diameter)
Irrigated long-cone
cyclone
Electrostatic
preci pita tor
Irrigated electrostatic
preci pita tor
Spray tower
Self-induced spray
scrubber
Disintegrator scrubber
Venturi scrubber
Wet-impingement scrubber
Baghouse
Overall
58,6
65,3
84.2
74.2
93.8
91.0
97.0
99.0
94,5
93.6
98,5
99.5
97.9
99.7
Particle size range, y ;
0 to 5
7.5
12
40
25
63
63
72
97
90
85
93
99
96
99.5
5 to 10
22
33
79
54
95
93
94.5
99
96
96
98
99.5
98.5
100
10 to 20
43
57
92
74
98
96
97
99.5
98
98
99
100
99
100
20 to 44
80
82
95
95
99.5
98,5
99,5
100
100
100
100
100
100
100
>44!
90 :
91
97
98
100
100
100
100
100
100
100
100
100
100
References 2 and 3.
Data based on standard silica dust with the following particle size and
weight distribution:
Particle size
range, u
Percent
by weight
0 to 5
5 to 10
10 to 20
20 to 44
>44
20
10
15
20
35
2/72
Appendix
A-5
-------
Table A-4. THERMAL EQUIVALENTS FOR VARIOUS FUELS
Type of fuel
Solid fuels
Bituminous coal
Anthracite coal
Lignite
Wood
Liquid fuels
Residual fuel oil
Distillate fuel oil
Gaseous fuels
Natural gas
Liquefied petroleum gas
Butane
Propane
Btu (gross)
(21,0 to 28,0) x
106/ton
25.3 x 106/ton
16.0 x 106/ton
21,0 x 106/cord
6.3 x 106/bbl
5.9 x 106/bb1
I,050/ft3
97,400/gal
90,500/gal
kcal
(5.8 to 7.8) x
1 06/MT
7.03 x 106/HT
4.45 x 106/HT
1.47 x 106/m3
10 x 103/liter
9.35 x 103/liter
9,350/m3
6.480/llter
6,0307 liter
Table A-5. WEIGHTS OF SELECTED
SUBSTANCES
Type of substance •
Asphalt
Butane, liquid at 60° F
Crude oil
Distillate oil
Gasoline
Propane, liquid at 60° F
Residual oil
Water
Ib/gal
8.57
4.84
7.08
7.05
6.17
4.24
7,88
8.4
g/liter
1,030
, 579
850
845
739
507
944
1,000
A-6
E ISSIO FACTORS
2/72
-------
Table A-6. GENERAL CONVERSION FACTORS
Type of substance
Conversion factors
Fuel
Oil
Natural gas
Agricultural products
Corn
Milo
Oats
Barley
Wheat
Cotton
Mineral products
Brick
Cement
Cement
Concrete
Mobile sources
Gasoline-powered motor vehicle
Diesel-powered motor vehicle
Steamship
Motorship
Other substances
Paint
Varnish
Whiskey
Water
Miscellaneous factors
Metric system
1 bbl = 42 gal = 159 liters
1 therm = 100,000 Btu = 95 ft3
1 therm = 25,000 kcal = 2,7 m3
1 bu =« 56 Ib = 25.4 kg
1 bu = 56 Ib « 25.4 kg
1 bu = 32 Ib = 14.5 kg
1 bu = 48 Ib = 21.8 kg
1 bu = 60 Ib = 27.2 kg
1 bale = 500 Ib = 226 kg
1 brick = 6.5 Ib = 2.95 kg
1 bbl = 375 Ib = 170 kg
1 yd3 = 2500 Ib = 1130 kg
1 yd3 = 4000 Ib = 1820 kg
12.5 mi/gal =5.32 km/liter
5.1 mi/gal =2.16 km/liter
44 gal/naut mi = 90 liters/km
14 gal/naut mi =28.6 liters/km
1 gal = 10 to 15 Ib = 4.5 to
6.82 kg
1 gal = 7 Ib = 3.18 kg
1 bbl = 50 gal = 188 liters
1 gal = 8.4 Ib = 3.81 kg
1 Ib = 7000 grains = 453.6 grams
1 ft3 = 7.48 gal = 28.32 liters
1 ft = 0.3048 m
1 mi = 1609 m
1 Ib = 453.6 g
1 ton (short) = 907.2 kg
1 ton (short) = 0.9072 MT
(metric ton)
2/72
Appendix
A-7
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REFERENCES FOR APPENDIX
1. Nationwide Inventory of Air Pollutant Emissions, 1968. U.S. DHEW, PHS,
EHS, National Air Pollution Control Administration, Raleigh, N. C.
Publication No. AP-73. August 1970.
2. Stairmand, C. J. The Design and Performance of Modern Gas Cleaning Equip-
ment. J. Inst. Fuel. 2^.58-80. 1956.
3. Si-airmand, C. J. Removal of Grit, Dust, and Fume from Exhaust Gases from
Chemical Engineering Processes. London. Chem. Eng. December 1965.
p. 310-326.
4U.S. GOVERNMENT PRINTING OFFICE: 1972 484/483 1-3
A-8 EMISSION FACTORS 2/72
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