INDUSTRIAL ENVIRONMENTAL RESEARCH
LABORATORY-RTF
ANNUAL REPORT
1976
OFFICE OF ENERGY, MINERALS, AND INDUSTRY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
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INDUSTRIAL ENVIRONMENTAL RESEARCH
LABORATORY (RESEARCH TRIANGLE PARK)
ANNUAL REPORT
1976
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Established on December 2, 1970,
by Reorganization Plan No. 3 of 1970,
the Environmental Protection Agency
is the Federal Government's lead agency
for pollution control and abatement.
EPA is concerned with the environment
as a single interrelated system
and is directing a coordinated research,
monitoring, standard-setting, and
enforcement effort to restore and
protect the quality of the environment.
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This report has been reviewed by the Environmental Protection Agency and
approved for publication. Mention of trade names, firms, or commercial products
does not constitute endorsement or recommendation for use.
Additional copies of this report are available from:
Technical Information Service (Mail Drop 64)
Industrial Environmental Research Laboratory
Environmental Protection Agency
Research Triangle Park, North Carolina 27711
The Laboratory also publishes reports which give details of the specific
projects and programs. A list of available reports is available from the
Laboratory's Technical Information Service. The reports are available to the
general public from:
The National Technical Information Service
U.S. Department of Commerce
5285 Port Royal Road
Springfield, Virginia 22151
11
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FOREWORD
This annual report presents the highlights of the programs and accomplish-
ments of EPA's Industrial Environmental Research Laboratory—Research Triangle
Park, between January .1 and December 31, 1976. Its.approach is an intentional
attempt to provide both the non-technical overview desired by the layman and
sufficient technical details for the professional.
Although this is only our second, year with the new name, abbreviated to
IERL-RTP, the public recognizes us readily as a group that has existed as an
organizational entity since 1965. The three-letter abbreviation RTP, following
our name, is significant only because of the existence of a sister laboratory
in Cincinnati, Ohio, following a parallel, but not duplicative, course.
Our former identity, Control Systems Laboratory, disappeared on July 1,
1975, following the implementation of a major reorganization of the program
and management structures of EPA's Office of Research and Development. Among
the benefits resulting from this reorganization were the delegation to us of
greater resource management and program implementation responsibility, and a
clarification and focussing of our mission as part of the newly created Office
of Energy, Minerals, and Industry.
Basically, IERL-RTP manages programs to develop and demonstrate cost
effective technologies to prevent, control, or abate pollution from operations
with multimedia environmental impacts associated with the extraction, proces-
sing, conversion, and utilization of energy and mineral resources, as well as
with industrial processing and manufacturing. The Laboratory also supports
the identification and evaluation of environmental control alternatives of
those operations as well as the assessment of associated environmental impacts.
Our program, consisting of inhouse activities, contracts, grants, and inter-
agency agreements, contributes significantly to the protection of National
health and welfare through the research and development of timely and cost-
effective pollution control technologies.
Although EPA is primarily a regulatory agency, the vital supportive role
of research and development activities within the overall EPA mission must not
be overlooked. Adequate pollution control technology, for example, must be
available before effective standards for the protection of public health and
welfare can be set and successfully enforced; the development of ever more
efficient and economical environmental control technology benefits not only
m
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the affected industry, but ultimately everyone. This is particularly true
considering the present energy situation; in the long run, the protection of
our environment and the conservation of our natural resources are integral
parts of meeting our energy requirements in a viable manner.
This report reflects EPA's concrete support of, and dedication to, the
practical realization of our Nation's energy goals, as well as those of a
purely environmental nature.
January 1, 1977
rJol/i K. Burchard
Sector
Industrial Environmental Research
Laboratory, RTP
IV
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TABLE OF CONTENTS
Page
Foreword i i i
Illustrations X1
INTRODUCTION 1
ENVIRONMENTAL POLLUTION CONTROL 2
Sulfur Oxides (SOX) 5
Nitrogen Oxides (NO ) 7
Particulates 7
Other Pollutants 9
PROGRAM METHODOLOGY 10
IERL-RTP PROGRAM AREAS 10
Utility and Industrial Power 11
Flue Gas Desulfurization Technology 11
Waste and Water Pollution Control 12
Flue Gas Treatment for NOX Control 13
Thermal Pollution Control 13
Particulate Control Technology 14
Energy Assessment and Control 15
Nitrogen Oxides Control 15
Fluidized-Bed Combustion 22
Coal Cleaning 23
Synthetic Fuels 25
Advanced Oil Processing 27
Other Support 28
Industrial Processes 29
Chemical Processes 29
Metallurgical Processes 29
Process Measurements 30
Program Operations 30
Special Studies 30
UTILITIES AND INDUSTRIAL POWER 33
PROCESS TECHNOLOGY 33
Flue Gas Desulfurization—Regenerable Processes 33
Magnesium Oxide Scrubbing (Chemico) 33
Sodium Sulfite/Bisulfite Scrubbing with
Thermal Regeneration (Wellman-Lord/
Allied Chemical) 35
Catalytic Oxidation (Monsanto Cat-Ox) 38
Aqueous Carbonate Process (Atomics
International) 40
Citrate Process 40
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TABLE OF CONTENTS (con.)
UTILITIES AND INDUSTRIAL POWER (con.)
Ammonia Scrubbing with Bisulfate Regeneration 42
Activated Carbon (Westvaco) 45
Reductant Gases 47
Non-Utility Combustion Source Control 47
Marketing Abatement Sulfur/Sulfuric Acid 49
Engineering Applications/Information Transfer 50
NOX Emission Control by Flue Gas Treatment 51
Strategy and Technology Assessment 51
Catalysts for Controlling NOX Emissions 51
Ozone Oxidation of NO Study 51
NOX Control Strategy Assessment 52
Japanese NOX Control 53
Economic Assessments of NOX FGT Processes 53
Experimental Projects 54
Catalytic Reduction of NOX with Ammonia 54
Planned Pilot and Prototype Plants 54
EMISSIONS/EFFLUENT TECHNOLOGY 55
Flue Gas Desulfurization—Nonregenerable Processes 55
Lime/Limestone Wet Scrubbing 55
TVA's Shawnee Power Plant 56
lERL-RTP's Pilot Plant 59
Bahco Process 61
Double-Alkali 61
Technology Development 62
General Motors Industrial Boiler
Demonstration 64
Full-Scale Utility Demonstration 64
Survey of FGD Systems 65
Flue Gas Desulfurization—Waste and Water Pollution
Control 65
FGC Waste Disposal Methods 65
FGC Waste Characterization, Disposal Evaluation,
and Transfer of FGC Waste Disposal Technology 65
Shawnee FGD Waste Disposal Field Evaluation 66
Louisville Gas and Electric Evaluation of FGD
Waste Disposal Options 66
Lime/Limestone Scrubbing Waste Characterization 66
Dewatering Principles and Equipment Design
Studies 68
Characterization of Effluents from Coal-Fired
Power Plants 68
Ash Characterization and Disposal 68
Alternative Methods for Lime/Limestone
Scrubbing Waste Disposal 65
Alternative FGC Waste Disposal Sites 69
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TABLE OF CONTENTS (con.)
UTILITIES AND INDUSTRIAL POWER (con.)
FGC Waste Utilization 69
Lime/Limestone Scrubbing Waste Conversion
Pilot Studies " 69
Gypsum By-product Marketing 69
Use of FGD Gypsum in Portland Cement
Manufacture 69
Fertilizer Production Using Lime/Limestone
Scrubbing Wastes 70
FGD Waste/Fly Ash Beneficiation Studies 70
Power Plant Water Reuse 71
Alternatives for Power Plant Water
Recycle/Reuse 71
Treatment of Flue Gas Scrubber Waste Streams
with Vapor Compression Cycle Evaporation 71
Thermal Pollution Control 71
Cooling Technology 72
Waste Heat Utilization 74
PARTICULATE TECHNOLOGY 75
lERL-RTP's Parti oil ate Program . 76
Measurement 76
Characterization and Improvement of Conventional
Control Equipment and Assessment of the
Collectability of Dusts 76
New Particulate Control Technology Development 76
New Idea Evaluation and Identification 77
Fine Particle Control for Combustion Processes
Utilizing Low-Sulfur Coal 77
Hi gh-Temperature/Hi gh-Pressure Particulate
Control 77
Current Program Status 78
Measurement 78
Characterization and Improvement of Conventional
Control Equipment 78
Electrostatic Precipitators 78
Scrubbers 81
Fabric Filters 83
Assessment of the Collectability of Dusts 85
New Particulate Control Technology Development 85
New Idea Evaluation and Identification 86
High-Temperature/High-Pressure Particulate Control 88
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TABLE OF CONTENTS (con.)
ENERGY ASSESSMENT AND CONTROL 89
COMBUSTION RESEARCH 89
Field Testing and Environmental Assessment 92
Utility Boiler/Power Generation Equipment Field
Testing 92
Field Testing of Industrial Boilers 94
Field Testing of Industrial Process Equipment 95
Residential/Commercial Heating Systems Testing 95
Environmental Assessment and Systems Analysis
of NOX Combustion Modification Technology 96
Process Research and Development 98
Combustion Modification for Utility Boilers 99
Combustion Modification for Industrial Boilers 100
Combustion Modification for Residential/Commercial
Heating Systems < 100
Stationary Engine Combustor Technology 101
Industrial Process Equipment and Afterburners 104
Fluidized-Bed Combustion Support 104
Fuels Research and Development 105
Improved Burner/System Design 105
Advanced Combustion Modification Techniques 105
Catalytic Combustion 110
Alternate Fuels 110
Fundamental Combustion Research 112
Combustion Chemistry 112
Combustion Aerodynamics 115
Application for Combustion Control 116
FUEL PROCESSES 116
Fossil Fuels—Coal 117
Coal Contaminant Characterization 117
Coal Cleaning 120
Environmental Assessment 121
Technology Development 121
Physical/Mechanical Coal Cleaning 121
Chemical Coal Cleaning 124
Meyers Process 124
Flash Desulfurization 125
Hydrothermally Treated Coal 126
Microwave Desulfurization 128
Synthetic Fuels 128
Environmental, Assessment 128
High-Btu Gasification 129
Low-Btu Gasification 129
Control Technology Development 132
Fossil Fuels—Oil 136
Oil Composition 136
Oil Treatment/Processing 136
vm
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TABLE OF CONTENTS (con.)
/
Page
ENERGY ASSESSMENT AND CONTROL (con.)
ADVANCED PROCESSES 137
Fluidized-Bed Combustion Processes 137
Fluidized-Bed Combustion of Coal 138
Environmental Assessment 138
Control Technology Development 138
Advanced Oil Processing: Fluidized-Bed Gasification/
Desulfurization of Residual Fuel Oil 143
Environmental Assessment 143
Control Technology Development 143
CAFB Demonstration ' 144
Advanced Low-Emission/Energy-Conserving Systems
Strategies 145
EPA-Van 145
Electrical Energy and Waste Heat 145
Fuel Distribution Pattern Flexibility 147
Indoor Air Quality 147
Basic Studies/FBC Pollutant Formation Mechanisms 147
INDUSTRIAL PROCESSES 149
CHEMICAL PROCESSES -• 149
Source Assessment 149
Combustion Sources 151
Conventional Combustion Systems—Emissions
Assessment 151
Electric Power Generation 153
Industrial Boilers 154
Petrochemicals 154
Ethylene Dichloride (EDC) Processes 154
Vinyl Chloride (VC) 155
Polychlorinated Biphenyls (PCBs) • • 155
Chlorolysis 156
Refineries 157
Source Assessment—Air Pollution 157
Technology Alternatives: Refinery SOx Control • 157
Automobile Filling Station Control ~ " 158
Agricultural Chemicals ' 159
Fertilizers 159
Pesticides 161
Textiles 162
ATMI Study 163
Other Projects 163
Environmental Assessment—Air Pollution
Sources .165
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TABLE OF CONTENTS (con.)
Page
INDUSTRIAL PROCESSES (con.)
Incineration at Sea 165
Miscellaneous Projects 166
Flare Systems 166
Vegetative Stabilization of Mineral Waste Heaps 166
Equilibrium Partial Pressure in AlkaVme Scrubbers 167
Odor Abatement "for Rendering Industry 167
GUIDELINES FOR ENVIRONMENTAL ASSESSMENT OF ENERGY SYSTEMS 168
METALLURGICAL PROCESSES 168
Iron and Steel Industry 169
Mining, Beneficiation, and Pelletizing 174
Cokemaking 176
Enclosed Coke Pushing and Quenching 176
Smokeless Coke Pushing 178
Guidelines for Coke Oven Pollution Control
Applicability 179
Characterization of Coke Oven Door Emissions 181
Improved Coke Oven Door Seals 182
Sintering 182
Iron and Steelmaking 187
Blast Furnace Cast House Emission Control 187
Basic Oxygen Process Charging Emission Control 187
Ferroalloy Production 188
Surface Preparation and Finishing 192
Fugitive Emissions and Surface Runoff 192
Abnormal Operating Conditions 193
Iron and Steel Foundry Processes 194
Nonferrous Metallurgy 196
PROCESS MEASUREMENTS 197
CONTROL EQUIPMENT EVALUATION . 197
Particul ate Measurement 197
High-Temperature/High-Pressure Sampling and 198
Measurement 199
Inorganic Sampling and Analysis 200
Organic Measurements
ENVIRONMENTAL ASSESSMENT TESTING STRATEGIES 201
Phased Sampling and Analytical Strategy 201
Fugitive Emissions 203
Biological Testing 203
QUALITY ASSURANCE 204
APPENDIX A. The Industrial Environmental Research Laboratory,
Research Triangle Park A-l
APPENDIX B. Metric Conversion Factors B-l
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ILLUSTRATIONS
Figure No. Title Page
1 Total U.S. energy requirement 3
2 Value of Eastern and Central coals meeting new source
performance standards as a function of efficiency of
flue gas cleaning processes 4
3 Control of NO emissions from coal-fired utility
boilers 8
4 Environmental assessment diagram 16
5 , Control technology development diagram 17
EPA/Boston Edison demonstrate Mag-Ox process 34
Wellman-Lord process to be demonstrated 36
EPA/Illinois Power demonstrate Cat-Ox process 39
Aqueous carbonate process 41
The Citrate process 43
Ammonia scrubbing with bisulfite regeneration 44
Activated carbon process 46
Versatile lime/limestone wet scrubbing demonstration
at Shawnee plant 58
IERL-RTP lime/limestone scrubber pilot plant 60
Three 20 MW prototype FGD systems at Gulf Power's
Scholz plant 63
Test pond for disposal of Shawnee's chemically treated
scrubber waste 67
Capital cost of ESP's vs. computed performance 80
Scrubber operating cost vs. aerodynamic cut diameter 82
Summary of 1974 stationary source NO emissions 90
A
Scotch marine boiler (60 hp) for emission control
equipment evaluation 97
225 KW gas turbine used for IERL-RTP inhouse studies "02
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Illustrations (con.)
Figure No. Title Page
Precombustion chamber diesel (300 hp) for
stationary engine controls development 103
Multiburner experimental furnace (3 million Btu/hr) 106
Full-scale burner test facility (125 million Btu/hr) 109
Experimental system for combustion modification and
future fuel studies 111
Hypothetical simplified gasification flow diagram 118
Concept of RTI reactor facility and sampling manifold 133
630 KW Exxon miniplant for pressurized (10 atm)
fluidized-bed combustion of coal 139
EPA-Van 146
Iron and steel industry unit operations (sheet 1 of 2) 170
Iron and steel industry unit operations (sheet 2 of 2) 171
Discharges from iron and steel industry (sheet 1 of 2) 172
Discharges from iron and steel: industry (sheet 2 of 2) 173
Mining, beneficiation, and pelletizing operation 175
EPA/National Steel coke pushing and quenching system 177
Koppers/Ford coke oven smoke emission abatement system 180
Weirton Steel Division sinter plant gas recirculation
system 184
Basic oxygen process 1 ton capacity pilot vessel 186
Ferroalloy production process 189
Open-hooded ferroalloy furnace ]91
Enclosed ferroalloy furnace with fixed seals i9l
Iron foundry process emission sources 195
SASS equipment for environmental assessment sampling 202
.xii )
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Illustrations (con.)
Figure No. Tj'tle Page
A-l Organization of the Industrial Environmental Research
Laboratory, Research Triangle Park A-4
A-2 The basis for IERL-RTP programs A-6
-xm
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INTRODUCTION
Since 1967 the Federal Government, in cooperation with industry, has made
.a determined effort to develop technology to control environmental pollution
produced by both stationary and mobile sources.
An organization—now the Industrial Environmental Research Laboratory,
Research Triangle Park (IERL-RTP), North Carolina—was designated to carry out
the major part of the Government's share of the effort relating particularly
to stationary sources of air pollutants. Since the June 30, 1975, reorganiza-
tion of EPA's Office of Research and Development (ORD), however, IERL-RTP's
pollution control efforts have been more encompassing. Since that date, and
with the cooperation and assistance of EPA sister laboratories previously
charged with appropriate pollution control responsibilities, IERL-RTP has ef-
fectively accomplished a major redirection of effort to provide a multimedia
approach to pollution control problems. The new multimedia program concerns
itself with air, water, solid waste, thermal discharge, pesticides, and energy-
conserving aspects of environmental pollution.
Congressional direction for this effort is provided principally by the
Air Quality Acts of 1967 and 1970, and the Federal Water Pollution Control
Acts and its Amendments.
.The latter cites two national policies specifically applicable to IERL-
RTP: the prohibition of "discharge of toxic pollutants in toxic amounts," and
a major research and demonstration effort to "develop technology necessary to
eliminate the discharge of pollutants into the navigable waters, waters of the
contiguous zone, and the oceans." Section 105 of the Act authorizes "research
and demonstration projects for prevention of pollution of any waters by indus-
try including, but not limited to, the prevention, reduction, and elimination
of the discharge of pollutants."
Among the purposes cited in Section 101 of the Air Quality Acts are: "to
protect and enhance the quality of the nation's air resources so as to promote
the public health and welfare and the productive capacity of its population;
(and) to initiate and accelerate a national research and development program
to achieve the prevention and control of air pollution. ..."
Two other sections of the Air Quality Acts are also significant, indicat-
ing Congressional support of specific activities of IERL-RTP: Section 103
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(Research, Investigation, Training, and Other Activities) and Section 104
(Research Relating to Fuels and Vehicles).
In Section 103, EPA's Administrator is authorized to establish a national
research and development program for the prevention and control of air pollu-
tion and, as part of that program, to conduct and promote the coordination and
acceleration of research, investigations, experiments, training, demonstra-
tions, surveys, and studies relating to the causes, effects, extent, prevention,
and control of air pollution. Section 104 specifically emphasizes research
into and development of new and improved methods, with industry-wide applica-
tion, of preventing and controlling air pollution resulting from fuels combus-
tion.
Figure 1 shows energy requirements* that relate the problem of air pollu-
tion to the single largest source of air pollution—fuel combustion. The main
cause of air pollution is combustion, accounting for over 80 percent of the
mass of recognized air pollutants, with both mobile and stationary sources
contributing substantially. If metallurgical processes and oil refining are
added to combustion, the total will be about 90 percent of the total mass.
In line with the U.S. energy policy to increase the nation's self-suffic-
iency in energy resources, a closer look has been taken at our coal reserves
which are relatively abundant in contrast to our limited oil and gas reserves.
Only about 7 percent of our coal resources, however, are usable under the New
Source Performance Standards. Figure 2 shows the need to develop techniques
to permit the use of eastern and western coals.
ENVIRONMENTAL POLLUTION CONTROL
The development and demonstration of environmental pollution control
technology is one of EPA's largest tasks. Approximately $45 million was de-
voted to this effort in FY 76 (including the transition quarter). These funds
supported both lERL-RTP's on-going studies to demonstrate control methods for
sulfur and nitrogen oxides, particulates, and other pollutants, and its ex-
panded programs addressing the environmental aspects of accelerated energy
resource development in the U.S.
lERL-RTP's goal in stationary source air pollution control development is
fourfold:
*A1though EPA policy is to use metric units, this report contains certain
nonmetric units for the convenience of the reader. Use the factors in Appendix
B to convert to metric equivalents.
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U.S. RESERVES--
COAL/CURRENTLY RECOVERABLE): 3.6 x1018 Btu
COAL (USGS TOTAL ESTIMATED): 77 x 10*8 Btu
URANIUM (LIGHT WATER REACTOR): 0.84 x 10*8 Btu I
URANIUM (BREEDER REACTOR): 18.5 x 10*8 Btu
1985 -116 X 1015,Btu '
^3 NUCLEAR'AND OTHER
25 50 75
rn»PORTS7percent
25 50
IMPORTS, percent
Figure 1. Total U.S. energy requirement.
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9375
Z5.00-
ESSENTIALLY ALL KNOWN RESERVES4flAJ)E
AVAILABLE BY 95% EFFICIENT FLUE GAS
CLEANING PROCESSES (EXAMPLE: WELLMAN-
LORD PROCESS)
5625,
CJ
oc
o
V)
3750
o
u.
o
1675.
ADDITIONAL RESERVES (TO 2.5% S) MEETING
NSPS MADE AVAILABLE BY 75% EFFICIENT
FLUE GAS SCRUBBING PROCESSES NOW
BECOMING COMMERCIALLY AVAILABLE
(EXAMPLE: WET LIMESTONE SCRUBBING)
NATURALLY OCCURRING LOW-SULFUR
COAL (<0.7% S) WHICH MEETS NSPS
Figure 2. Value of Eastern and Central coals meeting new source performance
standards as a function of efficiency of flue gas cleaning processes.
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0 To describe at least one method for controlling each major source of
pollution.
° To provide a technical base for the Agency's enforcement activities.
0 To establish technical and economic data to support New Source Per-
formance Standards (NSPS).
0 To provide information required to make environmentally sound
decisions on energy development policy.
Sulfur Oxides (SOj
— ^
The Agency has directed much of its research and development effort in
the sulfur dioxide (SO^) control area toward demonstrating flue gas desulfur-
ization (FGD) technology, in which SOo is removed from the gas stream emitted
after a fuel is burned. The emphasis on FGD has been dictated by its economic
feasibility and by its availability for near-term application as compared to
other SOo control options. EPA has funded, either totally or partially, a
number of major projects over the past several years. Included in these
projects are the following large-scale, electric utility oriented projects:
0 Pilot work (at Research Triangle Park, N.C.) and prototype systems (at
TVA's Shawnee Steam Plant) for development, demonstration, and optimi-
zation of lime and limestone scrubbing technology.
0 Magnesium oxide scrubbing demonstrations at Boston Edison Company and
Potomac Electric Power Company.
° Sodium sulfite/bisulfite scrubbing (Wellman-Lord Process) at Northern
Indiana Public Service Company.
0 Aqueous carbonate process demonstration at Niagara Mohawk.
0 Double-alkali process demonstration at Louisville Gas and Electric
Company.
Control techniques suited to smaller industrial and commercial combustion
sources are being examined in full-scale test programs at a General Motors
double-alkali installation, at a U.S. Air Force installation using the Bahco
lime scrubbing process, and at a St. Joe Minerals Company installation using
the citrate process. Supporting and supplementing these major demonstrations
are numerous other projects, such as full-scale testing on commercially in-
stalled systems, engineering studies, and smaller-scale hardware studies.
The commercial economics of FGD technology, including by-product market-
ing and disposal options, and the evaluation of new processes and of process
improvements, are subjects of continuing engineering efforts. A major effort
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underway in technology transfer will promote use of the best and most Reliable
techniques and equipment for future FGD installations.
The Agency is also studying a number of other approaches for reducing
sulfur oxide (SOV) emissions. One such approach is to "clean" a fuel—to re-
A
move sulfur and other contaminants—before the fuel is burned. This pretreat-
ment method is especially suited to sources smaller than electric utilities;
e.g., industrial boilers and fuel-burning equipment. EPA is studying (through
research, development, and environmental assessment) several techniques for
removing pollutants from fuels. One technique, coal cleaning, involves phys-
ically and/or chemically cleaning moderate-sulfur-content coal so that it can
be burned in conformance with clean air standards. EPA's objectives in this
area are: to develop commercially available processes for removing inorganic
sulfur and ash from medium-sulfur coal, while producing reuseable wastes, or
wastes which will not degrade the environment when discarded; to define the
environmental problems associated with Existing fuel cleaning technologies; .
and to derive means of minimizing problems which could hinder application of
fuel cleaning technologies. In the clean fuels area, EPA is also studying the
use of clean synthetic fuels (fuels produced from high- and low-Btu gasified
coal and liquefied coal). Now underway is a program on residual oil process-
ing and utilization aimed at defining better means of removing sulfur and
other pollutants, toward an end product of a clean synthetic fuel. The major
objectives of clean synthetic fuel studies are to determine the potential en-
vironmental impacts of processing these fuels, and to develop means of mini-
mizing the adverse environmental effects of synthetic fuel technologies.
Another approach to reducing SOV emissions is to modify the combustion
A
process. The Agency's efforts in combustion modification have involved pri-
marily the Fluidized-Bed Combustion (FBC) Process. These efforts have con-
tributed to the National Fluidized-Bed Combustion Program, an interagency
program coordinated by the Energy Research and Development Agency (ERDA).
EPA's contributions to the interagency program consist of environmental assess-
ments of FBC systems, optimizing control of S02> NOX, fine particulates, and
other pollutants in the FBC process, and continued testing of its small (0.63
megawatt) FBC mini-pilot-plant. The Agency also conducts independent research,
from an environmental perspective, to determine the implications of alternative
designs a'nd of alternative uses of fluidized-bed combustors.
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Nitrogen Oxides (NOV)
" *•'••-- /\
Combustion modification is the primary existing control technique for
preventing or minimizing NO emissions from fossil-fuel burning in utility and
*\
large industrial boilers; in small industrial, commercial, and residential
systems; in industrial process furnaces and afterburners; in stationary en-
gines; and in advanced processes.
Several combustion modification techniques have been developed or are
under study. EPA-supported and -directed efforts have shown that staged com-
bustion (often combined with low excess air) is an effective method of con-
trolling NO emissions originating from the thermal fixation of nitrogen
/\
emissions in combustion air and from the conversion of nitrogen atoms chemic-
ally bound in fuel (heavy oils'and coal). Flue gas recirculation has been
shown to be a most effective technique for controlling NO emissions originat-
. • "
ing from thermal fixation of atmospheric nitrogen during the combustion of
clean fuels (natural gas and distillate oils). Additional EPA research and
development efforts seek to modify combustion by redesigning burner/combustor
systems* to investigate novel approaches to combustion modification (such as
catalytic combustion, advanced power cycles, and alternative fuels), and to
provide, through basic research, an understanding of the physical and chemical
factors influencing the formation and degradation of pollutants.
Flue gas treatment (FGT) is another technique under investigation for its
potential as a highly efficient means of controlling NO emissions from sta-
/\
tionary sources. In the U.S. flue gas treatment developmental effort, EPA
will draw on the knowledge gained in Japan's now-active development of FGT.
Particulates
Control technology for large particulates has been fairly well established.
EPA's efforts now are mainly concerned with development of techniques for the
control of fine particulates (defined as that fraction of the particulate
emission smaller than 3 microns). These small particles remain suspended in
the atmosphere and are easily respirable and absorbable by the body. Fine
particulates may contain toxic trace metals and sulfates, both of which have
considerable impact on health. One current program seeks to better define the
physical and chemical character of fine particulates. The Agency's present
efforts center on developing adequate detection and measurement methods and on
development and field testing of control methods. Additionally, EPA is work-
ing to improve and demonstrate existing collection capability for fine
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00
i200!
1000
o 800
a*
CO
1 l
1 -, 600;
S
o
1 400
•as.
200
0!
1 1
y- PROJECTED
/r ACTUAL; ' '; :
1 ^\
\ *-,.
FIELD TESTING (700 ppm) -. . . _
\
L
L
N ^ FIELD TEST *\
N >. ^lESULTS^ \^
RF«:III T«: FRnwi FIFI n X >• ** *™ , n AVERAGE FROM
JSJirATin?nFKT %^ V NSPS(525ppm) BOILERS DESIGNED
APPLICA1ION Or lil ^^ ^. WITH LOW NO*
GENERATION RETROFIT^ ^N^_ *V^ S\ CAPABILITY
TECHNOLOGY .: " ^°-*^^ ''x^/ \
ENGINEERING R, D & D (300 ppm) ~~ "" "^ ^ — ->v
I ,\
X _
FUNDAMENTAL COMBUSTION RESEARCH (150 ppm) * ' v^
i
.1 II
71 72 73 74 75 76: 77
CALENDAR YEAR
FigureS. Control of NOX emissions from coal-fired utility boilers.
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participate control and to identify and ultimately to demonstrate novel tech-
niques which will offer both economic and performance advantages over current
methods.
Other Pollutants
"Other" pollutants are both those pollutants for which no ambient air
quality standards have been established and those three pollutants (asbestos,
mercury, and beryllium) for which National Emissions Standards for Hazardous
Air Pollutants (NESHAPs) now exist. Control technology research efforts are
underway for a number of these pollutants, including trace metals, polycyclic
organic matter (POM), and miscellaneous hydrocarbons, fluorides, and odors.
To assess the emission levels of these pollutants, several tasks are
being funded for the field testing of coal-fired utility and industrial boilers,
and for limited source characterization of gas- and oil-fired units. A field
testing program is underway for residential and commercial heating units.
Source assessment is also underway for certain chemical processing in-
dustries. The objective of this program is to assess the environmental impact
of sources of toxic and potentially hazardous emissions from organic materials,
inorganic materials, combustion and open source categories, and to determine
the need for control technology development for given source types. Sources
under assessment include petroleum refining, petrochemicals, nitrogen fertil-
izer operations, phosphate fertilizer operations, pesticides manufacturing,
and textile operations.
EPA has completed development at the pilot-plant level for ethylene
dichloride plants and odor control for the rendering industry. An extensive
testing program is underway to evaluate shipboard incineration of organic
chemical wastes as a disposal technique. Nearly complete is the first phase
of a test program designed to resolve the uncertainties in cost estimates for
gasoline station hydrocarbon control systems.
Control technology for ferrous metallurgical industries is under continu-
ing development. EPA has completed projects directed toward the control of
emissions from cokemaking, blast furnace tapping, and charging of basic oxygen
furnaces. Work is underway to develop full control of emissions from the
sintering of iron ore. Extensive efforts are underway to assess, and ulti-
.mately to bring under control, fugitive emissions from all significant sources
in the production of ferrous metallurgical products. The recent combining
into a multimedia program of the previously separated ferrous metallurgical
-------
air and water research and development programs is expected to result in
optimum control of all discharges from these industries.
PROGRAM METHODOLOGY
Over the past ten years, the Federal Government has gained perspective and
experience concerning its most effective involvement in pollution control ac-
tivities. The following considerations support a Federally coordinated environ-
mental pollution control research and development effort:
0 In order to achieve cost-effective environmental pollution control to
protect health and welfare, regulations should be based on a solid
information foundation. This may include such detailed knowledge about
the pollutants as health and welfare effects, sources and amounts,
ambient concentrations, available control technology, and opportunities
for research, development, and demonstration (RD&D) of new control
technology.
0 Few economic incentives exist for private industry to develop new
technology to control environmental pollution, because the people bene-r
fitting from the control are not the ones directly paying for it.
Traditional forces of the market place tend to preclude industrial
expenditures unrelated to profits.
0 Legal regulatory pressure, coupled with RD&D programs funded jointly
by Government and industry, appears to provide an effective mechanism
to ensure the availability of the necessary advanced environmental
pollution control technology. Users will not generally apply control
technology unless required to do so by law. Conversely, it would
appear impractical to shut down large segments of industry if tech-
nically and economically feasible control devices are not available.
Thus joint industry/Government technology development is desirable so
that a common understanding of the availability of technology is
shared by industry and Government.
IERL-RTP PROGRAM AREAS
Programs being pursued by IERL-RTP1s Divisions and Branches have been
realigned to reflect the multimedia and energy-related innovations resulting
from EPA's recent Office of Research and Development reorganization.
The newly aligned functions fall into three natural categories: utilities
and industrial power, energy assessment and control, and industrial processes.
10
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A fourth function, related but not identified with any other single current
program, is supportive of all IERL-RTP components. This fourth function falls
in the category of special studies, relating to program operations.
Utility and Industrial Power
lERL-RTP's Utilities and Industrial Power program was formulated to ensure
that adequate controls are available to prevent and abate pollution from util-
ity and industrial power sources. To achieve this objective, the program in-
volves multimedia research, development, demonstration, and environmental
assessment. Major elements of this program include: flue gas desulfurization
technology, waste and water utilization and control, flue gas treatment for
NOX removal, thermal pollution control, and particulate control technology.
FLUE GAS DESULFURIZATION TECHNOLOGY
Flue gas desulfurization (FGD) technology is the only near-term technolog-
ical approach to utilizing plentiful high-sulfur coal supplies without exces-
sive deleterious SO emissions. FGD technology development and assessment,
J\
therefore, are afforded a high priority. Studies indicate that FGD will be
competitive in cost with advanced control methods (e.g., chemical coal clean-
ing, fluidized-bed combustion); therefore, FGD may play an important role in
controlling emissions even in the post-19801s.
FGD technology has progressed rapidly over the past 4 years. Several
commercial FGD installations are achieving high SO removal efficiency with
/\
good reliability. EPA believes that lime and limestone FGD processes can now
be considered demonstrated technology, capable of being confidently applied
to full-scale utility boilers. However, more work remains to be done in the
FGD technology area, including: the development of cost-effective environ-
mentally acceptable disposal technology for the large quantities of sludge
produced from lime and limestone systems; the development and demonstration
of improved lime and limestone process variations which will minimize cost
and energy usage and improve sludge properties; and the development and
demonstration of economically viable regenerable FGD systems producing sulfur
and sulfuric acid instead of sludge.
For the last 8 years, IERL-RTP has been conducting a comprehensive
FGD development and technology transfer program, which has been instrumental
in accelerating the commercial viability of FGD technology. This program has
aimed at demonstrating reliable and cost-effective FGD processes, yielding botn
nonregenerable (throwaway) products and regenerable (or saleable) sulfur pr;ducts.
. 11
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lERL-RTP's major program in the nonregenerable area is the lime/limestone
prototype test program operating in cooperation with the Tennessee Valley
Authority at the Tatter's Shawnee Steam Plant. This program has been instru-
mental in identifying reliable, cost-effective process variations for both
lime and limestone scrubbing systems. Work continues on developing improved
process variations offering cost and operational advantages over present
commercial processes. Also in the nonregenerable FGD area, IERL-RTP has
initiated a comprehensive program aimed at identifying environmental problems
associated with scrubber sludge disposal, along with development and evalua-
tion of appropriate control practices. In order to provide a rionregenerable
alternative to lime/limestone systems, IERL-RTP is now undertaking the demon-
stration of the double-alkali scrubbing process on a full-scale coal-fired
boiler; this process offers the promise of significant reliability and cost
advantages.
In the regenerable FGD area, IERL-RTP has pursued an aggressive RD&D
.t
program aimed at identifying cost-effective processes with wide applicability
producing saleable sulfur products. EPA is working with the Department of the
Interior in developing sodium citrate scrubbing, a promising regenerable
system. Other regenerable processes which have proven to be promising at
pilot- or prototype-scale are being evaluated on full-scale coal-fired utility
boilers as part of the IERL-RTP FGD demonstration program: Wellman-Lord
(producing sulfur), magnesium oxide (producing sulfuric acid), and the aqueous
carbonate process (producing sulfur).
WASTE AND WATER POLLUTION CONTROL
A comprehensive research and development program is being conducted by
IERL-RTP to evaluate, develop, demonstrate, and recommend environmentally ac-
ceptable, cost-effective techniques for disposal and utilization of wastes
from flue gas cleaning systems, with emphasis on FGD sludge. Efforts are also
being conducted to evaluate and demonstrate systems for maximizing power plant
water recycle/reuse. This program is a continuation and expansion of modest
efforts initiated in the late 1960's in support of limestone scrubbing projects.
Projects under the program include laboratory and pilot field studies of
disposal techniques for untreated and chemically treated FGD sludges (e.g.,
lined and unlined ponding and landfill, coal mine disposal, and ocean dis-
posal); bench- and pilot-scale testing of FGD sludge utilization schemes
(e.g., sludge conversion to sulfur with regeneration of calcium carbonate);
12
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and pilot/prototype testing of water treatment schemes for maximizing overall
power plant water recycle/reuse. Engineering cost studies of each process/
technique being developed are also being conducted under this program. In
addition, several related projects are being conducted at TVA under IERL-RTP
sponsorship (e.g., fly ash characterization, disposal, and utilization studies;
FGD sludge solids characterization studies; bench/pilot studies of FGD sludge
use in fertilizers; FGD gypsum marketing studies; and studies of coal pile
drainage, ash pond effluents, and other power plant water discharges).
Results from the program are being published in annual summary reports,
the first of which was issued in late 1976.
FLUE GAS TREATMENT FOR NOY CONTROL
X
Another important part of IERL-RTP1s environmental program relating to
coal combustion is the NO flue gas treatment (FGT) program. The FGT program
/\
has two main elements: strategy and technology assessment, and experimental
projects.
The strategy and technology assessment element is designed to produce:
a detailed state-of-the-art technology assessment; an assessment of the extent
to which FGT could be used in an optimized control strategy for stationary
sources; and information concerning the economic, energy, and environmental
aspects of commercial application of FGT technology. The experimental proj-
.ects element is designed to provide for the development and demonstration of
FGT technology for removal of NOV with both high and low SOV concentrations
X X
and for simultaneous removal of both NOX and SO .
THERMAL POLLUTION CONTROL
Power plants reject enormous amounts of heat energy which is no longer
able to perform useful work in the power production cycle. Current projec-
tions indicate that waste heat rejection from central power stations in the
year 2000 will nearly equal the total U.S. energy consumption in 1970. Under
the provisions of the Federal Water Pollution Control Act Amendments of 1972,
EPA is required to regulate thermal effluents. IERL-RTP's research and de-
velopment program in the thermal control area supports the Agency's statutory
requirements and falls primarily into two broad areas: combustion source
cooling technology, and waste heat utilization. Programs underway in the
former area include analysis of first generation cooling system performance
and economics, assessment of advanced heat rejection techniques, and develop-
ment of control technology for treatment and reuse/recycle of cooling system
13
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effluent streams. Waste heat utilization studies presently underway involve
primarily agricultural applications. Aquaculture uses may merit future con-
sideration.
PARTICULATE CONTROL TECHNOLOGY
lERL-RTP's program for particulate control is designed to establish en-
gineering design techniques and performance models-, and to improve the col-
lectability and economics of control devices for particulate matter.
Attainment of the present Primary Standard for particulates in some cases
will be difficult and expensive with existing technology; attainment of the
Secondary Standard (or a more stringent Primary Standard) appears impossible
without improved technology. There are two basic causes for this: particulate
control technology has limited control capability, in many cases even for
coarse particulate; and technical and economic factors often prevent control
technology from being feasible in specific industrial applications.
IERL-RTP is placing increased emphasis on the control of fine particu-
lates which persist in the atmosphere, comprise a variety of known toxic sub-
stances, and are major contributors to atmospheric haze and visibility problems.
The objective is the development and demonstration of control technologies
capable of effectively removing large fractions of the under-3-micron size
particles from effluents. The technical approach is to identify capabilities
of existing equipment (electrostatic precipitators [ESPs], filters, scrubbers,
and proprietary devices), to determine deficiencies in present design and
operating procedures, and to pursue remedies for the deficiencies through re-
search and development. New concepts will be applied as discovered, and suc-
cessful advancements in removal technology will be demonstrated. Results will
be applicable to improvements in high-temperature/high-pressure particulate
removal devices.
Actual source tests have shown that both ESPs and baghouses should be
capable of controlling fine particulate from a limited number of sources emit-
ting fly ash. It is quite possible that the applicability of ESPs to fine
particulate control over a broad range of sources can be extended by develop-
ing dust conditioning techniques and by modifying the design of charging
sections and collecting electrodes. During 1976, a completed mathematical
model for the design of ESPs was greatly improved; this will allow cost-effec-
tive design for specific particulate control technology applications. Also
completed was the demonstration on actual sources at a pilot scale (10,000-
14
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30,000 CFM) of a charged droplet scrubber, a high throughput fabric filter,
and a flux force/condensation scrubber. In addition, a major program thrust
was initiated to find solutions to the particulate emission problems associated
with the burning of, or switching to, low-sulfur coal by a number of eastern
utilities.
Energy Assessment and Control
lERL-RTP's activities relating to energy assessment and control are
focused on two primary objectives: utility and industrial power; and energy
control technology (fuel processing). Within these objectives are several
energy technology areas:
0 Nitrogen oxides/combustion-pollutant control.
0 Fluidized-bed combustion.
0 Coal cleaning.
0 Synthetic fuels.
0 Advanced oil processing.
0 Other support (advanced, low-emission, energy conserving systems and
strategies).
The major activities of these multimedia programs—environmental assess-
ment and control technology development—can best be described in terms of the
components and relationships shown in Figures 4 and 5. An environmental
assessment is a continuing iterative study aimed at: (1) determining the
comprehensive multimedia environmental loadings achievable and costs, from the
application of the existing and best future definable sets of control/disposal
options, to a particular set of sources, processes, or industries; and (2)
comparing the nature of these loadings with existing standards, estimated
multimedia environmental goals, and bioassay specifications as a basis for
prioritization of problems/control needs and for judgement of environmental
effectiveness. EPA has been given responsibilities for environmental assess-
ment and control technology development in the energy area to ensure an inde-
pendent and timely environmental consideration of this national priority.
NITROGEN OXIDES CONTROL
IERL-RTP activities relating to NO and other combustion pollutant control
A
include the following subobjectives:
0 NO,, Environmental Assessment/Applications Testing—Determination of
~J\
the environmental emissions of NO and other combustion-related pollutants from
/\
stationary combustion sources. Evaluation of the environmental effectiveness
15
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CONTROL TECHNOLOGY
DEVELOPMENT
Engineering Analyst
Basic & Applied Processes Development
Specific Process Development A
Evaluation
CURRENT PROCESS TECH-
NOLOGY BACKGROUND
• Process Information
• Schedules
• Status
• Priorities lor further study
ENVIRONMENTAL DATA ACQUISITION
* Exlitlrte Data foe Each Process
• Identify Sampling and Analytical
Techniques Including Bloessay*
* Tan Program Development
* Comprehensive Waste Stream
Characterisation (Level* I, II. Ill)
Control Assays
CURRENT ENVIRONMENTAL
BACKGROUND
• Potential Pollutants &
Impacts in all Media
* Dose/Response Data
• Fed-/St«te Stds. Criteria
* Transport Models
ENVIRO
• Etta
Co
m*
• Oef
P»l
Pt-o
• Prlo
• Non
•Bio«
:ONTROL TECHNOLOGY ASSESSMENT
• Control System & Disposal Option
Information & Deitgn Principle
• Control Process Pollution & Impacts
• Procen Engineering PoUutvnt/Cost
Sensitivity Studim
• Accidental Release, Malfunction.
Trvnilant Op*'*tion Studies
• Ftald Tatting in n«lat«d Applica-
tlont
• Oafin* Bett Control T«chnlqu«
• Control Tachnologv R&D Plant &
Goal*
ENVIRONMENTAL OBJECTIVES
DEVELOPMENT
__3liih Permissible Madia
Cone, for Control Develop-
it Guidance
Define Decision Crlierle for
Of tilling Sources,
ibtems
ine Emlsiion Goals
_ritlz« Pollutants
Nonpollutant Impact Goalt
Bioaisay Criteria
ENVIRONMENTAL ALTERNATIVES ANALYSES
SOURCE IDENTIFICATION
(a, b.c, ...}
I Uncontrolled Pollutant Ident^end ' I
Quantificaiion (o e^^g-b^. bg. ...t ]
Apply Contiol Options and Dolina
CoiU (o. (I, 7. ...1
Controlled Poll. Cone, and
Emission Rate for Eech
Control Option
I Sum Pollutant* from
Alt Sources & Costs
Compare
rv/Goals S
Apply
Dachion
Criteria
Comply with Current
EmIsslon/FMIuent
Stds. or Bast Tach.
Practice
Comply with Current
or Proposed Ambient
Std*.
Stay Below Toxlctty-
Bas«d Eit- of Per-
missible Cone.
Stay Balow Ett. Per-
missible Cone, for
Zero-Threihold
Pollutants
ENJ/mONMENTA^ENGINEER.NG I ENVIRONMENTAL SCIENCES
ENVIRONMENTAL SCIENCES
JENVIRONM
\ TECHNOLl
.OGY TRANSFER
• Quantified Nonpoltut
Elf«cti & Siting Ctitc
All«rnailvcs
ENVIRONMENTAL ENGRG
TECHNOLOGY TRANSFER
ENVIRONMENTAL SCIENCES R«rD
Health/Ecological Effects Research
Trantpor t/Transformatfon Resaarch
HEALTH/ECOLOGICAL
IMPACTS ANALYSIS
• Air. Water, ft Land
Quality
• Increased Sick nets &
Death
• Ecology-Related
Effocts
• Malarial Related
Effects
Figure 4. Environmental assessment diagram.
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CONTROL APPROACHES:
ENVIRONMENTAL,
ASSESSMENT
Specific
Control
Needs
Defined
PRELIMINARY;
CONTROL
APPROACH
SELECTION
BASIC AND APPLIED R&D
Bench and Pilot Experimental Studies to
Assess Generic Types for Effectiveness
& Secondary Environmental Problems
Fundamental Studies
ENGINEERING ANALYSIS
Review Control Technique Alternatives
Based on Physical/Chemical Conditions,
Pollutant Cone., etc.
Assess Potential for Application (New,
Retrofit, Size, etc.)
Preliminary Design & Cost Studies
Systems Comparisons
SPECIFIC CONTROL PROCESS
DEVELOPMENT,EVALUATION
Conceptual Design & Cost Studies
Optimized Integration in Systems
to Be Controlled
Pilot & Demonstration Studies
Field Testing of State-of-the-Art
and Related Systems
Quantified
Effectiveness,
Economics, &
Energy Costs
MULTIMEDIA
ENVIRONMENTAL
CONTROL
ENGINEERING
MANUAL
• Additions
« Revisions
Figure 5. Control technology development diagram.
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(compared to the uncontrolled state) of combustion control modifications in-
cluding alternative operating conditions, retrofit control, maximum stationary
source technology (MSST) for existing units—extensive retrofit, and MSST for
new units—and optimized design or alternate processes. Significant accom-
plishments included:
00 Identification and characterization of stationary NO source categories.
^\
A final report, "Inventory of Combustion-Related Emissions from Sta-
tionary Sources," is under preparation.
00 Collection of field test data and establishment of state-of-the-art
combustion control for domestic and commercial heating systems.
00 Development of control technology goals based on best projections of
control technology research and development.
00 Initiation of a major NO environmental assessment contract for activi-
A
ties in this area as well as systems analysis and program support. A
report, "Preliminary Environmental Assessment of Stationary Source NO
/\
Combustion Control Technologies," is being prepared. It will contain
important information on stationary combustion equipment Categories,
fuel consumption data, and multimedia emissions inventories.
00 A final report, "Field Testing: Application of Combustion Modifications
to Control Pollutant Emissions from Industrial Boilers—Phase I," was
published by KVB. It describes the results of a 2 year field study of
industrial boilers. A supplemental report describes trace specie
sampling results.
00 Guideline manuals have been prepared for residential and commercial
space heating equipment service technicians. Similar guidelines are
being prepared for industt ial boiler operators and manufacturers and are
planned for utility boiler operators and manufacturers.
00 A pamphlet, "Get the Most from Your Heating Dollar—Servicing Cuts Costs
and Pollution," has been distributed to homeowners throughout the U.S.
It is designed to transfer technology developed during field tests of
residential equipment directly to the public.
00 A contract for assessment of afterburner technology is under negotia-
tion. The research and development, expected to be initiated by January
1977, will have as its primary objectives, environmental assessment and
expanded application of these emission control systems to a wider range
of industrial processes. A standards of practice manual will be developed.
18
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0 Develop Combustion Modification Technology for NO^—Development and
demonstration of practical combustion modification technology for controlling
NO and related combustion generated pollutants from utility and large
A
industrial, small industrial/commercial and residential system boilers, indus-
trial process furnaces and afterburners, stationary engines, and advanced
processes. Significant accomplishments include:
00 A two-volume final report, "Burner Design Criteria for Control of NO
A
from Natural Gas Combustion," was published by the Institute of Gas
Technology. The report documents in detail the NO control techniques
J\
for three burner types (kiln, ported baffle, and moveable-vane boiler
burner). NO reductions of nearly 90 percent were obtained depending
A
on burner type and burner operating conditions.
00 A final report, "Applicability of NO Combustion Modifications to
A
Cyclone Boilers (Furnaces)," is being prepared by Monsanto Research
Corporation. The report will document: background information on
cyclone boilers, cyclone boiler population data, and the state-of-the-
art of NO control for cyclone boilers.
A
00 Results of testing new tangentially coal-fired utility boilers designed
with overfire air systems for staged combustion have shown that NO
/\
levels as low as 0.45 Ib per million Btu can be achieved with no ap-
parent adverse effects.
00 A large-scale coal combustion facility (EPA Contract 68-02-1488) is
nearing completion. Full operation at up to 125 x 10 Btu/hr was
achieved in late 1976. The research and development for scale-up of
the optimum pulverized coal burner for utility and large industrial
boilers is finally underway.
00 The residual oil burner concept for package boilers has been developed
extensively and has achieved NO reductions of 65 to 70 percent for
A
three fuel oils with fuel nitrogen ranging from 0.2 to 0.71 percent.
The limit of NO control is imposed by the onset of unacceptable levels
A
of carbon particulate formation. Both fuel properties and atomizer
design appear to play a key role which will be investigated further in
a follow-on procurement currently in negotiation.
00 The prototype residential furnace has been designed based on experimen-
tally defined burner/firebox matching criteria. The prototype has been
successfully tested in a cyclic mode for 500 hrs and has maintained
19
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outstanding performance (i.e., 70 percent reduction in NO relative
/\
to current practice, no increase of CO, HC or smoke, and low excess
air operation). A follow-on letter contract has been signed for field
verification of production prototype units.
00 A low-cost burner head (approximately $1.50) has been developed and
tested which is applicable to 75 percent of U.S. oil-fuel furnaces for
reduction of emissions and increased efficiency. The Office of Minority
Business Enterprise is pursuing a commercialization program.
00 The first phase of a study of stoker-coal-fired combustion systems has
been completed. A final report on this phase, which emphasized resi-
dential and small commercial units, indicated that the primary emission
problems were smoke, particulate, and POM and that these emissions were
related to stoker operating parameters (e.g., ON/OFF cycles and over-
fire air) and coal composition (especially volatile matter). Signifi-
cant quantities of organics having high carcinogenic potential were
identified in the POM. The investigation will be extended, under a new
contract, to larger size units (spreader stokers) and both conventional
and processed coals. Emissions will be related to coal composition and
combustion modifications. Comprehensive sampling and analyses (Levels
1 and 2) will be used to provide environmental assessment data.
00 A survey investigation of industrial process furnaces and state-of-the-
art control technologies has been completed for five industries: iron
and steel, glass, aluminum, cement, and petroleum refining.
00 A current procurement is expected to result in initiation in January
1977 of research and development aimed at the development of low-emis-
sion, energy-efficient combustion chamber designs for large stationary
reciprocating engines (diesel and spark ignition). Demonstration of \.he
performance of the improved designs on full-scale engines is planned to
complete the program. Extension of the inhouse capabilities for high-
pressure combustion studies will permit further guidance and support
of the gas turbine and internal combustion engines (diesel) research.
00 Pilot-scale studies being conducted on EPA's versatile experimental
furnace by Aerotherm/Acurex are showing significant results. Recent
tests with coal under fuel-rich first-stage stoichiometry (0.85) and
"long" first-stage residence time (4 to 5 seconds) have yielded NO
/\
levels as low as 79 ppm (corrected to zero percent Op). This corresponds
to an NO reduction of 90 percent from normal baseline conditions.
A
20
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00 Catalytic combustion offers oromise of clean fuel combustion with very
low emission levels (i.e., 10 ppm) of NO , CO, HC, etc. The catalyst
/\
screening program has established one catalyst concept that appears to
have superior performance to all others tested. Extensive evaluation
of the concept is underway. In addition, other catalysts with higher
temperature (i.e., > 2200°F) capability are being sought. Following
final catalyst evaluations, systems concepts will be evaluated with
special emphasis on fuel NO control.
X
00 The ability.of package boilers to fire methanol has been established
by field tests. Methanol produced significantly lower NO emissions
/\ '
than either natural gas or heavy oil in a 24,000 pph watertube boiler
and a 12,500 pph firetube boiler.
00 A major new contract to consolidate the various fundamental combustion
research (FCR) activities under a single contract is nearing award (con-
tractor has been selected and negotiation is in progress). The con-
tractor will perform a large FCR effort himself and will subcontract
other efforts to several organizations. The thrust of the program is
application of FCR to the solution of practical problems in controlling
pollutants from stationary combustion sources.
00 Fundamental fuel pyrolysis experiments have identified HCN and NH3 as
the major oxidizable nitrogen species evolved under inert conditions.
Flat flame burner studies have examined the details of the conversion
of these compounds to NOV and N, under combustion conditions. These
A
experiments have verified that fuel NO is minimized under fuel-rich
conditions and that, with sufficient residence time, the oxidizable
nitrogen species are reduced essentially to zero.
00 Experiments on coal devolatilization at the Massachusetts Institute of
Technology have established that over 90 percent of the nitrogen species
can be driven off in the "volatiles" at high temperature. By minimizing
the fuel nitrogen in the char and control of volatile fuel N conversion
to NO in a rich primary zone, total NOV from coal can be reduced dras-
/\ ' /\
tically. This confirmation of postulates from burner data provides
valuable insight for further optimization of burner/combustor design
for pulverized coal combustion.
00 Extension of the application of combustion modification to coal-fired
utility boilers has been shown to have the potential to reduce NO
/\
emissions by up to 50 percent for this source category.
21
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00 Initiation of mini demonstration test programs for use of low-sulfur
western coal in intermediate sized boilers appears to show substantial
potential for use of low-sulfur western coal as an SOV control approach
X
for small and intermediate sized coal-fired units which are not eco-
nomically controlled by FGC.
FLUIDIZED-BED COMBUSTION
Subobjectives comprising lERL-RTP's fluidized-bed combustion (FBC) program
are:
0 FBC (Environmental Assessment)—Characterization of air, water, solid
waste, and other environmental problems associated with atmospheric and pres-
surized FBC processes; development of environmental objectives; publication of
a best-available technology manual; and provisions of an overall preliminary
environmental assessment analysis. lERL-RTP's program to environmentally assess
FBC has produced the following accomplishments:
00 Initiation of the FBC environmental assessment activity, including
initiation of work by the FBC broad environmental assessment contractor
(Battelle).
00 Initiation of comorehensive analysis of emissions from a variety of FBC
units, including atmospheric units at ERDA's Morgantown Energy Research
Center (MERC) and Battelle-Columbus Laboratories, and pressurized units
at Exxon and at Combustion Systems Ltd./British Coal Utilization Re-
search Association (CSL/BCURA).
00 Contacts with ERDA to lay the groundwork for conducting comprehensive
analyses at ERDA facilities, including the 30 MW atmospheric boiler at
Rivesville.
00 Initiation of efforts to establish environmental goals for FBC based on
health and ecological effects, including initial efforts on the Multi-
media Environmental Goals Chart.
00 Continued bench-scale investigation of air and solid emissions control
from FBC units, including sorbent regeneration (Argonne, Exxon, Westing-
house).
00 Provision of substantial environmental support to ERDA's FBC program.
00 Identification of potential FBC environmental problems requiring control
research and development.
0 FBC (Control Technology Developments-Development of laboratory- and
bench-scale multimedia control technology for SO , NO , total particulates,
X X
22
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hydrocarbons, CO, and hazardous and other pollutants frorrnFBC. Development of
treatment and final disposal techniques for spent sorbent and ash. Demonstration
of techniques at available pilot facilities. Significant accomplishments
include:
. °° Completion of installation of a Ducon granular bed filter for high-
temperature/high-pressure particulate control on the Miniplant.
00 Continued laboratory- and bench-scale investigation of air and solid
emissions control from FBC units, including sorbent regeneration
(Argonne, Exxon, Westinghouse).
00 Contacts with ERDA to initiate planning for testing EPA's mobile par-
ticulate control test devices on the 30 MW Rivesville boiler.
00 Contacts with ERDA to lay the groundwork for establishing a large field
cell near the Rivesville site to test the environmental impact of dis-
posal of solid residue from the facility.
00 Completion of shakedown of the integrated Miniplant combustor/regenera-
tor systems, including a 100 hour continuous run with continuous circu-
lation of sorbent between the combustor and the regenerator. Regenera-
tion reduced fresh sorbent requirements to 15 to 25 percent of that
which would have been necessary to achieve the same degree of SO^ removal
without regeneration.
COAL CLEANING
IERL-RTP subobjectives relating to coal cleaning are:
°. Physical/Chemical Coal Cleaning (Environmental Assessment)--Comp1ete
characterization of the environmental problems from existing coal.cleaning
plants and coal handling methods; definition of environmental .goals for coal
-cleaning plants as a function of time; assessment of control .technology in re-
lation to these.goals; publication of a manual of recommended practice for
near-term goals; and modeling of the applicability of coal cleaning on a
national and regional basis. Significant accomplishments this program has
produced include: , . ,
00 Major environmental assessment contract for coal cleaning signed with
Battelle and project work initiated.
00 Protocol between GPU and EPA signed for the cooperative evaluation of
the coal cleaning plant at Homer City/Penelec.
00 Report, "Atmospheric Potential from Fossil Fuel Resource Extraction,
On-Site Processing and Transportation," issued.
23
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00 Computerized data base for the characteristics of some 450 different U.S.
coals established.
00 Washability studies/trace contaminants in coal and residues continuing.
Coal preparation wastes Teachability studies initiated.
0 Physical/Chemical Coal Cleaning (Control Technology Development)
00 Cleaning and Handling Facilities--Development and demonstration, where
needed, of the best available technology for multimedia pollution control from
coal cleaning plants, coal storage, and coal transportation systems in coordi-
nation with the standards-setting timetables.
- Work underway to identify preliminary control/control development needs.
00 New Coal Cleaning Technology—Development and demonstration of advanced
technologies for cleaning coal of sulfur, nitrogen, ash, and potentially
hazardous trace pollutants. Promotion of the commercialization of promising
processes. Significant accomplishments this program has produced include:
- Revised report, "Sulfur Reduction Potential of U.S. Coals," issued.
- Bench-scale demonstration completed of the effectiveness of pyrite leach-
ing as a means of removing pyritic sulfur from a variety of coals, in-
cluding those not amenable to physical desulfurization.
- Identification made of specific U.S. coals amenable to desulfurization
by pyrite leaching in report, "Applicability of the Meyers Process for
Chemical Desulfurization of Coal; Survey of 35 Coals."
- Construction initiated of a facility to demonstrate pyrite leaching at
the pilot-plant scale (TRW-Meyers Process).
- Independent review initiated of oilot-plant designs to identify alterna-
tive concepts and equipment and evaluate their technical merit.
: - Economic and engineering design analyses made of commercial-scale chem-
ical processes for extraction of pyritic sulfur from coal.
- Construction of Multistream Coal Cleaning Strategy (MCCS) demonstration
plant progressing satisfactorily at Homer City. This plant will
eventually control 1850 MW of capacity at a capital cost of $53 million.
- Encouraging desulfurization results achieved using Institute of Gas
Technology's flash desulfurization concepts at bench-scale. However,
extensive early testing will need to be done to determine carcinogenic
and other hazardous potentials of the desulfurized product.
- Application and process improvement studies of Battelle's Hydrothermal
Coal Process underway.
24 '
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- EPA/USBM coal cleaning program expanded. Need identified for more
sophisticated control/instrumentation techniques. Two-stage froth
flotation demonstration agreements finalized. Design underway on a
coal cleaning research facility.
- Six areas of research identified by basic fuel contaminant removal
study. Two reports published: "Fuel Contaminants: Volume 1. Chemistry,"
and "Fuel Contaminants: Volume 2. Removal Technology Evaluation."
SYNTHETIC FUELS
lERL-RTP's program on synthetic fuels includes the following subobjectives:
0 Synthetic Fuels from Coal (Environmental Assessment)—Characterization
of multimedia pollution and other environmental problems from processes for
conversion of coal to synthetic fuels. Development of environmental goals,
assessment of control technology in relation to these goals, publication of
standards-of-practice manuals, and provision of an overall preliminary environ-
mental assessment analysis. The synthetic fuels environmental assessment oro-
gram has produced substantive results as follows:
00 Analysis completed of over 100 coal samoles from eastern and midwestern
coal sources (over 1,500 individual trace element analyses).
00 Identification made of potential pollutant releases by several conver-
sion processes: Koppers-Totzek gasification, Synthane gasification,
Lurgi gasification, C02 acceptor gasification, Bi-gas gasification,
COED liquefaction, and SRC liquefaction. Final report issued entitled
"Evaluation of Pollution Control in Fossil Fuel Conversion Processes."
00 Initial perspective provided to those with a need to know on the poten-
tial hazards associated with some synthetic fuel processes and the
relative potential environmental attractiveness of other processes.
00 Background information obtained on needs, that indicates the desira-
bility of focusing the program primarily on commercial and first gen-
eration processes needed for energy independence.
00 Completion of an analysis of high- versus low-temperature cleanup of gas
streams with emphasis on application of combined cycles. (High-tempera-
ture cleanup was about 5 percent more efficient, but had other potential
environmental problems.)
00 Completion of an analysis of problems and opportunities in retrofitting
industrial processes to utilize low-Btu gas. (Industrial processes,
representing a significant portion of energy use in industry, can be
adapted to low-Btu gas use.)
25
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00 Examination of commercial-scale gasification plants in five foreign
countries, and contracts for operational data and pollutant-emission
measurement on Lurgi units in several countries.
00 Sponsorship of a 1974 symposium that produced a comprehensive report
on the state-of-knowledge on environmental effects on fuel conversion
processes.
00 Publication of a survey of potentially hazardous emissions from the
extraction and processing of coal and oil.
00 Major contractors for environmental assessment of coal gasification
(Radian) and liquefaction (Hittman/Versar) are active along with a support
contractor (Cameron Engineers).
00 Research and development support for gasification New Source Pollution
Standards (NSPS) development initiated.
00 Kosovo gasification plant (Lurgi) environmental data acquisition studies
initiated.
00 Negotiations for information/testing of the Sasol gasification/liquefac-
tion plant underway.
00 Research grant initiated with the Research Triangle Institute to iden-
tify pollutants and chemistry of pollutants associated with coal con-
version.
0 Synthetic Fuels from Coal (Control Technology Development)—Development.
evaluation, and demonstration of environmentally sound control technology for
multimedia pollution and other environmental problems from synthetic fuel
processes in coordination with the goals defined in the environmental assess-
ment studies. Significant accomplishments include:
00 Major contractor on board for products/by-products control technology
(Catalytic).
00 Negotiations underway on two other major control technology contractors
(Converter Output, and Preparation, Water, and Waste).
00 Raw and acid gas bench-scale cleaning facility underway with an opera-
tion and study research grant active at North Carolina State University
and construction contract active with Aerotherm Corporation. Initial
studies will be aimed at NSPS support for controls for commercial or
near-commercial technology.
00 Water treatment bench-scale facility studies initiated through a re-
search grant at the University of North Carolina.
26
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00 Wrap-up work being completed on development and bench-scale demonstra-
tion of a highly effective desulfurization process for high-temperature
fuel gas.
ADVANCED OIL PROCESSING
Advanced oil processing activities in which IERL-RTP is involved include
the following subojectives:
0 Advanced Oil Processing (Environmental)—Characterization of waste
streams from oil processing methods and evaluation of the applicability of
alternate advanced oil processing methods for utilization of petroleum residuals;
evaluation of the application of available control technology; and publication
of a manual of best-available technology in coordination with the standards-
setting timetables. Significant accomplishments include:
00 Residual oil conversion/utilization identified as a national multimedia
environmental problem with diverse potential consequences ranging from
atmospheric sulfates to hazardous oil spills.
00 An inventory completed of potential pollutants in crude oils from
specific locations (domestic and foreign).
00 Background report developed entitled "Residuum and Residual Fuel Oil
Supply and Demand in the United States. . .1973-1985."
00 A major environmental assessment contractor on board to provide environ-
mental tradeoffs on all existing and projected processing/utilization
options for residual oil.
00 Contract negotiations initiated for comprehensive categorization and
characterization of residual oils.
00 Report issued entitled "Environmental Problem Definition for Petroleum
Refineries, Synthetic Natural Gas Plants, and Liquefied Natural Gas
Plants."
0 Advanced Oil Processing (CAFB Development)—Demonstration at small to
moderate commercial-scale of the chemically active fluid bed (CAFB) process for
converting heavy high-sulfur, high-metals content residual oils to clean,
high-temperature gaseous fuel. Significant accomplishments include:
00 Success in the pilot-plant program with design work begun on demonstra-
tion of CAFB process on utility boiler as an environmentally sound fuel
switching technique.
00 Progress report issued entitled "Development of the Chemically Active
Fluid Bed Process, A Status Report and Discussion."
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00 Continuous operation of the CAFB pilot plant at Esso Petroleum, Ltd.,
for periods as long as 412 hours and 212 hours between decaklng or
cleaning of the gas duct. Sulfur removal percentages of 85 percent and
vanadium retention of 100 percent on the bed material based on residual
oil inputs.
00 Pilot testing of coal feedstocks in the continuous CAFB pilot plant
begun in support of the planned demonstration.
00 Design/construction of a 10 MW demonstration plant at Central Power and
Light (CPL), San Benito, Texas, underway with Foster Wheeler Corporation
as prime contractor.
00 Westinghouse control technology studies have shown that the trace metals
sequestered by the bed material are bound tightly and will not leach
out into the environment. The spent sorbent shows promise as a compo-
nent of concrete. The spent bed material was found to contain very
little, if any, organic compounds.
0 Advanced Oil Processing (Control Technology Developments-Development
and demonstration, where needed, of technologies for the removal of sulfur,
nitrogen, and potentially hazardous trace materials from petroleum, petroleum
derivatives, and other liquid fuels. Development and evaluation of the best-
practical control technologies for commercial or near-commercial processes.
00 Determination of the fundamental characteristics of the reactions in-
volved in simultaneous hydrodesulfurization and denitrification. Re-
port issued entitled "Catalytic Desulfurization and Denitrogenation."
00 Identification of specific catalysts that tend to optimize demetalliza-
tion of oils, and preliminary estimates of catalytic demetallization
and desulfurization of specific Venezuelan, Soviet, and Iranian oils.
Phase III report issued entitled "Demetallization of Heavy Residuals.
00 Work initiated to optimize denitrogenation of residual oils.
OTHER SUPPORT
IERL-RTP has done some work in support of other subobjectives, especially
relating to advanced low-emission/energy-conserving systems and strategies.
The following significant accomplishments have resulted:
00 Completion of the construction of an advanced domestic energy utiliza-
tion system demonstration involving solar panels, heat pump, fuel cells,
and catalytic burner. Identification of a need to explore impact of
air quality degradation on solar energy cost effectiveness.
28
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00 Completion of a paper feasibility study which indicated a number of ap-
plicable approaches for increasing efficiency of small heating systems
and also indicated potential for the Heat and Emission Loss Prevention
System (HELPS) employing direct contact water heat exchanger to scrub
fuel gas from residential/commercial furnaces and bring furnace effi-
ciency from 80 to almost 97 percent while reducing pollution. Recom-
mendations for follow-up were made to IERL-CIN.
00 Definition of the potential for low environmental impact use of electri-
cal energy as a substitute for clean fuels which can go a long way
toward helping the United States meet the goals of Project Independence.
00 Publication of a preliminary study on the extent to which clean and
dirty fuels can be switched to aid in reduction of pollution.
00 Publication of Phase I report on a comprehensive program to evaluate
indoor air quality and its relationship to energy conservation.
Industrial Processes
The Industrial Processes program seeks to identify, develop, and demon-
strate cost-effective technologies for the abatement of multimedia pollution
associated with industrial processing and manufacturing. The program involves
the identification, characterization, and quantification of pollutants from
assigned industries; the experimental modification of process equipment, opera-
tions, raw materials, and products; and the application of control processes,
devices, or systems.
CHEMICAL PROCESSES
The segments of the Chemical Process Industries which are assigned to
IERL-.RTP include petrochemical manufacture, petroleum refining, agricultural
chemicals manufacture, textile manufacture, conventional combustion assessment,
and incineration at sea. Work underway consists of comprehensive multimedia
environmental assessment in.all of these areas plus control technology development
in some areas where the need for such has already been identified.
Details of the Chemical Processes projects appear later in this report.
METALLURGICAL PROCESSES
In the metallurgical field, IERL-RTP has been assigned responsibility for
iron and steel. This includes integrated iron and steel production, ferroalloy
production, and iron foundries. These efforts cover minim,, beneficiation,
pelletizing, cokemaking, sintering, iron,and steel manufacture, ferroalloy
production, surface preparation and finishing, fugitive emissions and surface
29
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runoff, and abnormal operating conditions. Details of programs in these
areas appear later in this report.
Process Measurements
The Process Measurements Branch (PMB) is responsible for all measurements
programs in IERL-RTP. Major areas of activity are carried out through a co-
ordinated contract/inhouse effort. Program areas include methods evaluation
and development, review of test programs and proposals, evaluation of test
results, on-site troubleshooting, and special field studies. Inhouse activi-
ties include coordination of measurement programs with IERL needs, review of
the measurement aspects of all procurement plans and proposals, and specialized
measurements to fill gap areas. Contract activities include methods develop-
ment, measurement program reviews, and on-site troubleshooting. Six specific
areas of expertise are developed through the contracting program: inorganic
sampling and analysis, organic sampling and analysis, particulate sampling,
fugitive emissions, high-temperature/high-pressure measurement, quality
assurance.
The current major thrust of PMB's work is in support of lERL-RTP's environ-
mental assessment program. The major objective is development of a conceptual
approach to a coherent sampling and analytic program suitable for application
to a wide variety of environmental assessment programs. Concurrently, work
is conducted in the areas of quality assurance and control equipment evaluation
as techniques, methodology, and instrumentation continue to be improved and
expanded. The PMB is publishing a series of technical and procedural manuals
oriented toward IERL-RTP project requirements.
Details of the PMB program are described later in this report.
Program Operations
A majority of this report is concerned with details of programs relating
to the IERL-RTP line divisions. The fourth IERL-RTP organizational group, the
Office of Program Operations, provides staff technical and program administra-
tion support to the Office of the Director, IERL-RTP, including essential
functions encompassing program and project analysis, review, planning, and
data analysis and interpretation.
SPECIAL STUDIES
Within the Office, of Program Operations, the Special Studies Staff provides
technical analysis and assessment support to the Office of the Director. This
function includes broad technical assistance in program planning, guidance, and
30
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review; recommendations to the Laboratory Director for program direction;
technical assistance to Laboratory comoonents in data analysis and interpre-
tation; and technical evaluation of projects or programs as may be requested
by the Laboratory Director or other Laboratory components. Other services
provided by the Special Studies Staff include management of engineering
services contracts and consultation on technical aspects of Laboratory com-
puterized data processing applications.
During the past year, special studies conducted by the Staff have covered
a wide range of activities. Statistical reviews were made of experimental
test plans on data from numerous projects, including boiler corrosion during
combustion modification tests, charged droplet scrubbing, fluidized-bed com-
bustion, and Wellman-Lord/Allied scrubbing demonstration.
Technical analyses of several Laboratory programs were conducted or
initiated during the year, including a new advanced flue gas desulfurization
demonstration proposal. In addition to Laboratory projects, a number of un-
solicited grant and contract proposals were reviewed and appropriate recom-
mendations regarding them were made to the Laboratory Director. To support
the develooment of cost-effective control technology by other Laboratory
components, a program has been initiated to formulate standard cost-estimating
procedures which may be utilized uniformly throughout the Laboratory. In
order to provide IERL-RTP with an awareness of programs and activities in
other laboratories, special studies include maintaining liaison with such
laboratories involving health effects, ambient air quality studies, and
standards development which may have significance upon control technology
development. In this regard, special studies included the preparation of
lERL-RTP's contribution to the criteria document for lead ambient air quality
as part of an inter-laboratory Office of Research and Development (OR&D) task
force.
During the past year, several major projects were either initiated or
continued in support of particular Laboratory or OR&D objectives. These in-
clude the development of a computerized information system on fine particle
emissions from stationary sources, the initiation of an integrated assess-
ment of coal-based energy technologies, an environmental assessment of energy
supply systems using fuel cells, and a compilation of industrial process
profiles.
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The computerized Fine Particle Emissions Information.System (FPEIS) pro-
vides an extensive compilation of data on stationary source testing and
evaluation of control technology. Numerous requests for information from the
FPEIS were received following its development. Data which may be found in the
FPEIS include particle size distributions; results of chemical and biological
analysis of the particulate sample; process description of the source; design
and operating parameters of applied control technology; and description of
the measurement equipment and techniques employed during data collection. Con-
tinuing development and improvement of the FPEIS is planned.
The Integrated Assessment of Coal-based Energy Technologies will identify,
describe, compare, and quantify where possible the range and magnitude of
environmental, socio-economic, and energy impacts of the development and de-
ployment of such energy technologies, supply systems, and end uses. From
this total assessment, alternative policies will be recommended that will
achieve the best balance of environmental quality, energy efficiency, economic
costs, and social benefits, and strategies will be proposed for policy imple-
mentation.
The Environmental Assessment of Energy Supply Systems Using Fuel Cells
examines the potential role of emerging fuel cell technology in the nation's
future as a localized source of energy for multi-family residential heating
and cooling. Consistent with current energy policy emphasis, the study
focuses upon coal-derived fuels for use in fuel cell applications. Close
cooperation with concurrent ERDA programs is maintained to ensure that maxi-
mum benefits may be obtained by both the ERDA and IERL-RTP programs.
The Industrial Process Profiles for Environmental Use (IPPEU), formerly
called the Environmental Catalog of Industrial Processes (ECIP), presents in
several volumes a detailed description of selected processes from 24 chemica,
and metallurgical process industries. Each profile identifies the process in-
puts, the end products, the quantity and type of waste streams to be expected,
and the quantity and types of utilities (water, air, etc.) required by each
process.
Similar special studies will be conducted in the future as needed to
respond to the evolving mission and interests of IERL-RTP.
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UTILITIES AND INDUSTRIAL POWER
lERL-RTP's work in the area of utilities and industrial power can be
subdivided into three distinct functional groupings: process technology,
emissions and effluent technology, and particle technology. The following
subsections of this report discuss these groupings separately.
PROCESS TECHNOLOGY
Flue Gas Desulfurization--Regenerab1e Processes
MAGNESIUM OXIDE SCRUBBING (CHEMICO)
The Mag-Ox scrubbing process—developed by Chemical Construction Company
(Chemico) and Basic Chemicals, and currently offered commercially by Chemico—
is one of the more promising regenerable flue gas desulfurization approaches. .
The process is based on the reaction of magnesium oxide with sulfur dioxide to
form magnesium sulfite, which is removed from the scrubber effluent by cen-
trifugation. The magnesium sulfite is dried (to remove surface and bound
moisture) before being calcined to regenerate magnesium oxide for recycle and-.
sulfur dioxide for conversion to sulfuric acid or other saleable products.
The chief advantage of the process is its wide applicability to both
existing and new power plants: it removes both sulfur dioxide, and particles
very efficiently without interfering with normal boiler operation. The process
is also amenable to the centralized processing concept; i.e., spent sorbent can
be regenerated at a central plant capable of servicing a number of power or
industrial plants. The major disadvantage of the process is its relatively
high regeneration energy requirements. Other disadvantages include those
common to wet scrubbing processes; e.g., the apparent requirement for stack
plume reheat.
In 1974, IERL-RTP and Boston Edison completed a $9 million cofunded
demonstration program involving the design, construction, and operation of a
155 MW capacity scrubbing/regeneration system (see photo). Scrubbing; cen-
trifuging, and drying operations were located at Boston Edison's oil-fired
Mystic Station; a regeneration system was constructed at Essex Chemical's
sulfuric acid plant in Providence, R.I. The system was started up in April
1972. Results obtained during 2 years of operation indicate that sulfur
dioxide removal efficiencies in excess of 90 percent were obtained consistently,
using both virgin and regenerated:magnesium oxide. Additionally, more than
V 33
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_ ABSORBER
Ifl INLET
»'DUCTWORK
WgO STORAGE
SILO
ABSORBER
OUTLET
BREECHING
DUCTWORK
FROM BOILER
RECYCLE
PUMPS
(NOT VISIBLE)
EPA/Boston Edison demonstrate Mag-Ox process.
34
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5,000 tons of commercially saleable sulfuric acid of high quality were produced
from the sulfur recovered from the stack gas and sold conventionally. A number
of problems were solved that were primarily equipment (rather than process)
related. Consequently, continuous, long-term, reliable operation was not
achieved. However, from mid-February until June 1974, the scrubbing system
demonstrated an availability of about 90 percent. The final report on this work
is available from NTIS.
Potomac Electric Power Company has installed a 100 MW Mag-Ox scrubbing
system at its coal-fired Dickerson Station. Since completion of the EPA/Boston
Edison program in June 1974, EPA provided the Providence Mag-Ox regeneration
system for Potomac Electric's use in processing spent scrubber sorbent. Potomac
Electric supplied data relative to overall system operation on coal-fired
plants. Results indicate S02 removal efficiencies greater than 90 percent with
few discernible differences between coal- and oil-ffred boiler applications.
Work on this program has been completed, and the final report is being prepared.
Two studies in support of Mag-Ox scrubbing are being conducted currently.
Radian Corporation has evaluated the feasibility of producing elemental sulfur
directly from magnesium sulfite. This would expand the applicability of cur-
rent Mag-Ox processes. Another study is concerned with the mechanism of forma-
tion of tri- and hexa-hydrate forms of magnesium sulfite (MgS03*3H20, MgS03
•61^0). The hexa-hydrate crystals separate and handle easily; the tri-hydrate
crystals require less drying energy but are more difficult to separate and
handle. The study has attempted to generate information on formation mecha-
nisms and operating conditions that can be used to control the type of crystal
formed. Final reports on the two studies will be available soon.
SODIUM SULFITE/BISULFITE SCRUBBING WITH THERMAL REGENERATION
(WELLMAN-LORD/ALLIED CHEMICAL)
IERL-RTP and Northern Indiana Public Service Company (NIPSCO) jointly
funded the design and construction of a flue gas cleaning demonstration system
utilizing the Wellman-Lord (W-L) S02 recovery process. The Allied Chemical S02
reduction process will be used with the W-L process to convert the recovered
S02 to elemental sulfur. The total $11 million cost for design, construction,
and start-up was borne equally by IERL-RTP and NIPSCO. The operational costs
for the system will be borne solely by NIPSCO, and a detailed test and evalu-
ation program will be funded by IERL-RTP. The demonstration system has been
retrofitted to the 115 MW, coal-fired Boiler No. 11 at the D.H. Mitchell Sta-
tion in Gary, Indiana. (See photo.)
35
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Co
CTl
Wellman-Lord process to be demonstrated.
-------
Phase I of the three-phase program, completed in December 1972, entailed
the development of a process design, major equipment specifications, and a
detailed cost estimate. Phase-II, the final design and construction, was
completed by Davy Powergas, Inc., (owner of the W-L process) in August 1976.
Davy constructed both the W-L and Allied portions of the system. After the
completion of start-up activities, the plant will be operated by Allied
Chemical Corporation under contract with NIPSCO. During the demonstration
year a comprehensive test and evaluation program will be carried out by TRW, ,
Inc., under contract with IERL-RTP.
The W-L process utilizes a sodium sulfite/sodium bisulfite solution to
absorb S02 from gas streams containing a wide range of inlet S02 concentra-
tions. Spent absorbent, rich in bisulfite, is processed in a steam-heated
evaporator/crystal!izer, regenerating active sodium sulfite and a stream of
SOp for further processing. The basic chemistry of the W-L process can be
represented in simple form as:
Absorption--
S02 + Na2S03 + H20 -*• 2NaHS03
Regeneration—
2NaHS03 heat' N^V +SV +H2°*
The process generates inactive sodium sulfate by three mechanisms: SCL
absorption, disproportionate, and sulfite oxidation. In order to maintain
adequate levels of active sodium sulfite and to avoid excessive steam demand,
it is necessary to purge sodium sulfate from the absorber/evaporator loop.
Since the purge results in the need to dispose of or market an additional
system product as well as loss of useful sodium ions, much emphasis has been
placed on purge minimization in development of the demonstration system.
The S02 product from the W-L process is suitable for recovery in three
forms: liquid S02, sulfuric acid, and elemental sulfur. For purposes of the
IERL-RTP/NIPSCO demonstration, the Allied Chemical S02 reduction process will
be applied to generate elemental sulfur. The Allied process utilizes natural
gas as a reductant in a proprietary catalytic reactor system. The process has
been demonstrated on a large scale, treating a 12 percent S02 gas stream from
a nickel ore roaster at Sudbury, Ontario.
IERL-RTP has high confidence for the success of this first coal-fired
boiler demonstration system in meeting guarantees for pollution control,
37
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product quality, and material and utility requirements. This confidence is
based on the already appreciable quantity of successful operating exoerience
to date for W-L systems on various applications including acid plants, Claus
plants, and oil-fired boilers. About 25 systems are now in operation in the
United States and Japan. The knowledge gained from operating these systems
has resulted in a series of process improvements (reducing costs and purge
requirements) which have been incorporated in the IERL-RTP/NIPSCO demonstration.
CATALYTIC OXIDATION (MONSANTO CAT-OX)
The catalytic oxidation (Cat-Ox) process is an adaptation of the contact
sulfuric acid process. Monsanto Enviro-Chem Systems, Inc., has developed this
adaptation through work on a pilot-scale unit, followed by a 15 MW prototype.
IERL-RTP and Illinois Power Co., sharing the $8 million total funding require-
ment, have been attempting to demonstrate the process on a 103 MW coal-fired
boiler at Illinois Power's Wood River Station (see photo). Detailed design,
construction, and shakedown testing of the system took about 3 years;
performance guarantee testing was carried out using gas-firing of the reheat
burners in July 1973. The unit met all guarantees and was subsequently ac-
cepted. Because of the shortage of natural gas, however, the burners were
modified to allow either oil- or gas-firing, as conditions permit. Design and
start-up problems have precluded successful initial operation and initiation
of the comprehensive 1 year test program.
A thorough technical and economic study has been made of the costs and
benefits of continuing the demonstration at Wood River. Results of this study
have led to the decision to end the project.
A major factor that entered into the decision to terminate the demonstra-
tion program was the conversion to low-sulfur coal at Wood River. Since only
one of the generating units at Wood River has an FGD unit, the utility has
chosen to comply with S02 regulations by burning low-sulfur coal. (They are
physically constrained from burning a different coal in the Cat-Ox generating
unit.) This step significantly reduced the benefits from a Cat-Ox demonstra-
tion, designed to produce sulfuric acid on the flue gas from a high-sulfur
fuel. In addition, extensive and very costly refurbishments and modifications
are required at Wood River. Acid coolers would have to be replaced as would a
large fraction of the acid circulation piping and brickwork.
Thus, it has been mutually agreed by all parties that, despite the failure
to demonstrate either feasibility or infeasibility at Wood River, further .
38
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gELECTROSTATIC
r PRECIPITATOR
UUNGSTROIYI »
HEAT
EXCHANGER
1 "
EPA/Illinois Power demonstrate Cat-Ox process.
39
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large expenditure of funds cannot be justified and that the demonstration
project must be discontinued.
AQUEOUS CARBONATE PROCESS (ATOMICS INTERNATIONAL)
IERL-RTP and Empire State Electric Energy Research Corporation (ESEERCO),
a research organization sponsored by New York's eight major power suppliers,
have recently contracted to fund jointly the design and construction of a
demonstration of Atomics International's sulfur-producing Aqueous Carbonate
Process (ACP). In addition to its $8 million share of the expected $22 million
in project cost, IERL-RTP will fund a detailed test and evaluation program.
The demonstration is being retrofitted to Niagara Mohawk Power Company's 100
MW coal-fired Huntley Station in Tonawanda, New York.
The demonstration will be in four phases. Phase I, the design and cost
estimate, is expected to be completed by mid-1977, and Phase II, construction,
by mid-1979. Acceptance, Phase III, should be accomplished by the end of
1979, at which time a 1 year test and evaluation program, Phase IV, will be
initiated.
In the Aqueous Carbonate Process (see following illustration), sodium
carbonate is contacted with the flue gas in a spray dryer. A reaction with
S02 takes place, forming sodium sulfite as a dry powder which is collected and
regenerated as follows. The dry product is fed, along with carbon (in the
form of either coal or coke), to a molten salt bath, which is maintained in
the 900 to 1000° C range. The sulfite is reduced to sulfide; carbon is
oxidized to carbon dioxide. The molten sodium sulfide is solidified, broken
up, and dissolved in water, and the solution is filtered to remove ash. The
clarified solution is then contacted with the carbon dioxide-rich off-gas from
the reduction step to regenerate sodium carbonate and evolve hydrogen sulfide.
The hydrogen sulfide is fed to a Claus plant where elemental sulfur is produced.
CITRATE PROCESS
IERL-RTP and the U.S. Bureau of Mines have entered into a cooperative
agreement to pool funds and technical talents to demonstrate the Citrate
process which has been developed through pilot scale by the Bureau of Mines.
A concurrent development program, carried out by an industrial consortium
headed by Pfizer Chemical Company, also led to a successful pilot operation of
the process. Based on the success of these two pilot programs, IERL-RTP and
the Bureau of Mines have initiated the demonstration of this technology on a
53 MW coal-fired boiler at St. Joe Minerals Corporation in Monaca, Pennsylvania
40
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SOLIDS COLLECTION
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REDUCER OFF-GAS .5 1 « cT1
H~O tt 1
Q <
^ j
Ma2S-RICH
QUENCH AND ^ RPp'
JOLUTIOISI F'LTRATION "
, (
JCTION
ASH AND
COKE
AIR
Aqueous carbonate process.
-------
(coal to be at least 2.5 percent sulfur). The contract between USBM and St. Joe
Minerals was signed in June 1976, and Phase I, initial design and cost estima-
tion, was completed in November 1976.
As shown in the generalized flow sheet below, the Citrate process consists
of five steps: gas cleaning and cooling, S02 absorption, sulfur precipitation
and solution regeneration, sulfur separation, and FUS generation. After gas
cleaning and cooling (to remove particulate"matter and to reduce flue gas temperature),
an aqueous solution containing sodium sulfite, sodium bisulfite, sodium thio-
i - '
sulfate, and other sulfur compounds absorbs SCL 'from the flue gas stream. The
solution is buffered with citric acid to maintain pH at an optimum level for
high-efficiency scrubbing 'and' Ingh-S02 loading capacity. The SC^-rich scrubber
liquor is then fed to a series of reactors where; gaseous H2$ is added. Although
a number of reactions take place in these reactors, the net reaction is the
combining of S02 and H2S to form elemental sulfur, which precipitates and is .
then separated by flotation. The recovered sulfur is melted to separate out the
residual scrubbing solution. A portion of the sulfur is sent to an hLS genera-
tor where it is reacted with reducing gas; the remainder is sent to product
storage for subsequent sale. The regenerated solution is returned to the scrub-
ber, and the H2S generator product is sparged into the regeneration reactors.
AMMONIA SCRUBBING WITH BISULFATE REGENERATION
Stack gases have been commercially desulfurized by contact with solutions
of ammonium sulfite and bisulfite since the mid-19301s. The early processes
recovered S02 in a pure form by acidifying the scrubbing liquor with sulfuric,
nitric, or phosphoric acid. The resulting ammonium salt of the acid was further
processed for use as a fertilizer. Because of the enormous tonnages of S02
involved in desulfurizing power plant stack gases, fertilizer markets are not
expected to support wide-scale use of fertilizer-producing ammonia processes.
Therefore, IERL-RTP, in a joint venture with TVA, undertook the development of a
completely cyclic ammonia-scrubbing/bisulfate-regeneration process which has as
its major product a concentrated stream of S02 which can then be used to produce
sulfuric acid or elemental sulfur.
The process (shown below) removes S02 from stack gases by absorption in a
solution of ammonium sulfite and bisulfite. Scrubber product liquor is acidified
with ammonium bisulfate to evolve S02 and form ammonium sulfate. This ammonium
sulfate solution is partially evaporated and'the ammonium sulfate crystallites.
After separation, the ammonium sulfate crystals are thermally decomposed into
42
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CO
GAS CLEANING
AND
COOLING
CLEANED AND
COOLED GAS
FLUE:
GAS
H20-
S02 ABSORPTION
TO ATMOSPHERE
SULFUR PRECIPITATION i
AND I
SOLUTION REGENERATION I
H2S GENERATION
S02
LIQUOR
STEAM
REDUCTANT
GAS
The Citrate process.
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SCRUBBED GAS RATE = 3,000 scfm
H20
DIRTY GAS
NH4HS03
(NH4)2S03
(NH4)2S04
S02
1
ACID
STRIPPER
I
NH4 HS04
EVAPORATO
KYSTALLlZf
(NH4)2S04
SOLUTION
CONDENSER
H20
NH-
CR
AkSOA
YSTALS
(NH4)2S04
DECOMPOSER
Ammonia scrubbing with bisulfite regeneration.
44
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ammonium bisulfate and ammonia. The ammonium bisulfate is returned to the
acidifier, and the ammonia is absorbed into a solution and returned to the
scrubber. Sulfites that are oxidized into sulfates during the process must be
purged from the system.
This ammonia scrubbing process was evaluated at a 3000 cfm pilot plant
located at the Colbert Steam Station in northern Alabama. Initial efforts at
the pilot unit site concentrated on the absorber, and have since included work
on all of the subunits of the system except the decomposer. As evaluation of
the process continued, it became apparent that the process had two major prob-
lems: (1) the formation of a persistent fume which could not be controlled or
eliminated by reasonable control efforts, arid (2) unfavorable economic projec-
tions due primarily to energy consumption by the decomposer. As a result of
these problems, the development project was terminated during the summer of
1976. ;
'ACTIVATED CARBON (WESTVACO)
The use of multistage, dry fluidized-beds of recycling .activated carbon
appears attractive both for sorption of SO from flue gases and for converting
" •
the removed SO to elemental sulfur. Under an IERL-RTP contract, development
/\
of the activated-carbon-based flue gas desulfurization process was advanced to
a stage where three major process units--sorber, sulfur generator, and carbon
regenerator—were integrated for continuous and cyclic operation.
In the sorption stage, shown schematically below, combustion flue gas is
contacted with the activated carbon, and the contained sulfur dioxide (in the
presence of oxygen and moisture) is first catalytically converted into sulfur
trioxide, and then to sulfuric acid, which is adsorbed by and contained in the
pores of the activated carbon.
In the sulfur generator, sulfuric acid contained in the activated carbon
is reacted with hydrogen sulfide to produce the elemental sulfur which remains
on the carbon.
In the carbon regeneration stage, the sulfur-loaded activated carbon is
reacted with a measured quantity of reducing gas which sweeps out the deposited
sulfur. About 25 percent of deposited sulfur is recovered as a by-product; the
remaining 75 percent is converted into hydrogen sulfide to decompose sulfuric
acid in the sulfur generator unit. Activated carbon is continuously returned
to the sorber.
45
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pAAl ftp NATMPAI
GAS GAS
*• HKUUUUbK J
_ y
AC-
CAR
FLUE GAS (S02)
1
";
^H2 —
•IVE
BON
f
--— *^" SULFUR GENERATOR
•S 1 ^ p/ SULFUR ^
T 1 X^ PRODUCT
SULFUR STRIPPER j
| l— CT
^. HYDROGEN SULFIDE GENERATOR
• . CLEAN
SULFUR DIOXIDE SORBER FLUE GAS
T
Activated carbon process.
46
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Integrated pilot plant operation, as a culminating point in the effort to
determine overall technical feasibility of the process, is complete. Cyclic
operation of the approximately 300 scfm capacity pilot plant has yielded en-
couraging results. Estimated process economics, based on these results, appear
to compare favorably with those of other flue gas desulfurization processes.
Westvaco, under contract to IERL-RTP, has prepared a detailed final report on
this process. The report includes results of the test work and cost estimates
for a hypothetical large-scale commercial application. There are no current
plans to continue this project.
REDUCTANT GASES
As part of its program for developing and demonstrating SO control tech-
i /\
nology for fossil-fuel-fired steam-generating equipment, IERL-RTP is currently
supporting (or evaluating for future support) the development of several flue
gas desulfurization (FGD) processes which recover the SO as elemental sulfur.
y\
Elemental sulfur may be the most desirable form for recovery of SO because it
/\
is the minimum quantity of any FGD waste or by-product and because of its
saleability, ease of transport, and suitability for long-term storage.
Production of sulfur from SO requires the use of a reductant for conver-
X
sion of the SOV to sulfur: to date, major emphasis has been on the use of
A
natural gas for this purpose. In view of the{current and continuing shortage
of natural gas, it is imperative that other sources of reductant gas be uti-
lized in the future. IERL-RTP has embarked on a program leading to the demon-
stration of processes and equipment for economical generation of reductant
gases from more plentiful ultimate sources, such as coal, coke, residual oil,
and petroleum coke.
As a first step, IERL-RTP retained Battelle-Columbus Laboratories to
conduct process evaluation and cost estimates of gasification processes that
are suited for application to FGD requirements, and to recommend avenues of
continuing development and demonstration. The report is available from NTIS.
An example of the use of an alternative reductant is the EPA demonstration of
Atomics International's Aqueous Carbonate Process which uses either petroleum
coke or coal.
NON-UTILITY COMBUSTION SOURCE CONTROL
Modeling studies have shown that the impact of non-utility combustion
(NUC) source S02 emissions on ambient air concentrations is higher than antici-
pated from their fraction of the amount of SOp emitted. For example, in St.
-------
Louis, area sources accounted for 15 percent of the SOp mass emissions, but
contributed 40 percent of the ultimate ambient concentration.
The first step in lERL-RTP's approach to reducing NUC source sulfur
dioxide emissions has been to compile and standardize a data base that charac-
terizes fossil-fuel combustion NUC sources which are about 50 MW in capacity
(about 500,000 pounds of steam per hour) or less, and which are categorized as
industrial or commercial/institutional. The base, developed by Battelle-
Columbus Laboratories, draws together all pertinent information and contains
data on such factors as number, size range, boiler type, fuel usage, and emis-
sion. The end product of this effort is a set of recommendations of strategies
and technologies for implementing an NUC source control program.
Battelle has also conducted for IERL-RTP a review of available package
sorption processes that can be applied to the control of sulfur oxide emissions
from the lower size range of the boiler population described above, as well as
from residential sources. Initial activity is directed toward extending the
characterization of NUC sources down to small combustion sources. Recommenda-
tions of strategies and technologies for implementing control programs for
small sources are also to be included. Stress is on existing technology, but
Battelle has also gathered information on emerging technology. Desirable
characteristics of a package sorption device would include small size, simple
installation, off-the-shelf availability (essentially shop fabricated), easy
operation by nonspecialized personnel, low capital and operating costs, minimum
waste products, useful or marketable by-products, and multipollutant control
capability. All of this work was included in the final report, "SO^ Reduction
in Non-utility Combustion Source'-," which is available from NTIS.
PEDCo-Environmental Specialists, Inc., under contract to IERL-RTP, is
evaluating the relative impact of SO emitted from utility and non-utility
A
combustion sources on ambient air quality. Existing air quality and emission
data from selected regions will be gathered, analyzed, and extrapolated for
more extensive use. These data will be correlated with actual field data from
a major metropolitan area. The field data, gathered during the summer of 1975,
are based on sampling ambient air resulting from tracer-doped emissions from
utility and non-utility sources. The large number of non-utility combustion
sources makes their consideration necessary in an overall SO control scheme.
J\
In a separate task, PEDCo will survey non-utility combustion sources that
are applying or considering the application of various strategies for control
48
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of SO emissions. Meetings will be held with regulatory agencies and indus-
X
trial representatives in the selected study areas to determine the various
strategies/technologies in use and to conduct surveys of selected plants. The
overall applicability of each control technology to each study area will be
assessed and the results extrapolated to other areas.
MARKETING ABATEMENT SULFUR/SULFURIC ACID
By-products of flue gas desulfurization processes fall into two categories:
throwaway and saleable. In the latter category are sulfur, sulfuric acid, and ,
(to a much lesser extent) gypsum.
Under interagency agreement with IERL-RTP, TVA has studied the economics
of marketing sulfuric acid that could theoretically be produced from its coal-
fired plants. The study assumed that TVA would be the only utility producing
abatement acid and that the existing production, distribution, and marketing
patterns would be changed only slightly by the introduction of abatement acid.
The objective was the creation of a model for estimating the net sales revenue
to TVA. Of the total 18,109 MW of TVA's coal-fired capacity, it was assumed
that 9,806 MW would be considered for sulfuric acid production. The study made
no attempt to select a process or to estimate production costs: it was assumed
that the acid would have a zero value at the point of production.
Results indicate that the net sales revenue of abatement acid would range
from $6 to $9 per ton of 98 percent sulfuric acid, and might reduce the cost of
operating a power plant sulfur oxide control system by 10 to 20 percent. The
final report of this initial study is available from NTIS.
A second phase of the marketing study is also underway. In this phase,
TVA is considering all potential abatement acid or elemental sulfur from power
plants located in states that are served by the inland waterway system in the
Eastern United States. These include states bordering the Mississippi River
and its navigable tributaries, the Great Lakes, and the Eastern seaboard: they
encompass Minnesota, Iowa, Nebraska, Kansas, Oklahoma, Texas, and all states
east of these. Unlike the first phase, however, this is not a hypothetical
model, but is based on the actual utility and sulfuric acid plant population of
the region in question. Moreover, TVA's computer program is considering com-
pliance with sulfur dioxide emissions standards and is to identify optimum
production and distribution patterns based on freight costs and market demand.
As in the first phase, the net sales revenue is to be estimated. A preliminary
report of this work was prepared in March 1976. Based on the favorable results
49
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obtained so far, this second phase was expanded to include abatement acid or
elemental sulfur from power plants throughout the contiguous 48 states. The
project was also expanded to include marketing of ammonium sulfate and calcium
sulfate (gypsum) in addition to sulfur and sulfuric acid, .
A final report covering the marketing of abatement sulfur, sulfuric acid.,
and calcium sulfate is planned for early 1977. A report on the use of sulfur,
sulfuric acid, and ammonium sulfate in fertilizer production and marketing is
planned for 1978.
ENGINEERING APPLICATIONS/INFORMATION TRANSFER
The Process Technology Branch of IERL-RTP has initiated a program to
disseminate more effectively air pollution control technology data and informa-..
tion to meet the needs of the user community. In the past the Laboratory has
attempted to meet its technology/information dissemination responsibility
primarily through periodic symposiums, reports, and personal communications.
These activities will be continued, but they will be augmented by a comprehen-
sive Engineering Applications/Information Transfer (EA/IT) Program now being
designed by IERL-RTP and contractor personnel to assure the efficient and
effective dissemination of information on pollution control technology to all
concerned sectors of the nation.
The expanded EA/IT program will assess the control technology information
needs of industry, utilities, vendors, control/enforcement agencies, and others;
compile information and data from past, current, and continuing government/
industry development and demonstration efforts; use the data/information to
design EA/IT programs and materials; and develop and implement effective mecha-
nisms for dissemination of the programs and materials to the user community.
Sample EA/IT materials which are being evaluated are (1) a Summary Report on
the Wellman-Lord FGD process, (2) a Quarterly Report of Progress in FGD Re-
search Development and Demonstration sponsored by EPA, and (3) a Lime Scrubbing
FGD Data Book.
One specific facet of the comprehensive EA/IT program is the design,
development, and implementation of a Flue Gas Cleaning Decision Model (FGC-DM).
The FGC-DM will provide one-source availability of pertinent FGC data and
information gathered from past and present FGC efforts within EPA, TVA, Electric
Power Research Institute (EPRI), the utility industry, FGC vendors, and other
foreign and domestic organizations. The objective of the FGC-DM is to assist
potential users in choosing an FGC system for a specific location with specific
50
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requirements/restrictions. Thus, the FGC-DM will make available a means of
effective, informed FGC decision-making which should result in earlier opera-
tional dates, lower costs, and increased operability/avail ability.
NO Emission Control by Flue Gas Treatment
STRATEGY AND TECHNOLOGY ASSESSMENT
Catalysts for Controlling NO,, Emissions
' " " ™ '""---J---lr ~ - -•' -m-r-m . _ I . *" A~ ~ ~ ~
In 1975, a research grant was awarded to the University of California at
Los Angeles (UCLA) School of Engineering and Applied Sciences to further the
development of promising catalysts. The study extended the catalyst screening
work performed earlier by UCLA under an IERL-RTP contract with TRW, Inc. The
objectives of the grant were to optimize the compositions of the vanadium and
iron-chromium catalysts for selective reduction of NO with ammonia and to
/\
perform long-term durability studies of the optimum catalyst compositions in
flue gas containing sulfur dioxide.
The results of the study indicate that a 15 percent loading of vanadium
oxide on alumina support material and a 10 percent loading of iron oxide-
chromium oxide on alumina support material with ah iron/chromium ratio of 9:1
were the optimum catalyst formulations.
Parametric tests showed that both catalysts were selective in the presence
of Op with strong enhancement of NO conversion rates due to the presence of 02
under typical operating conditions. Neither CO,, nor FUG was found to affect
the NO reduction in the concentration ranges applicable to power plant exhaust.
A
Both catalysts were most active between 400° and 425° C and required excess NH^
for maximum activity. Long-term durability tests of both catalysts in the
presence of SO indicated no degradation in catalyst performance. Typical
/\
conversion levels for the vanadium and iron-chromium catalysts operating at
400° C in simulated flue gas were about 90 percent and 80 percent, respectively,
at 20,000 hr"1 space velocity.
A final report is available on the UCLA grant work entitled "Parametric
Studies of Catalysts for NOX Control from Stationary Power Plants," EPA-600/7-
76-026.
Ozone Oxidation of NO Study
A series of studies is planned to estimate the supply, demand, production
economics, and energy consumption of key FGT process steps. Ozone is used as
the oxidizing agent in nearly all of the wet processes for NOV removal being
X
developed in Japan. Under an IERL-RTP task order, the Research Triangle In-
stitute (RTI) analyzed the conversion of NO to N02 by gas phase reaction with ozone.
51
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The results of the study indicate that to a good approximation only a
stoichiometric amount of ozone is required to achieve essentially complete
conversion of NO to N02» which may be subsequently scrubbed from the gas stream.
The energy requirements and the capital and operating costs were examined
for ozone generation with air and oxygen as feed to the ozone generator.
Approximately 13 percent more energy is required for ozone generation from
ozygen feed than air feed. The capital investment for ozone generation from
oxygen is about three times as large as that required for ai'r feed and operat-
ing costs are about twice as large.
For a 500 MW plant with air as feed to the ozone generator, the animates
for oxidizing 200 ppm of NO were: energy requirement, 1.1 X 10 kWh/yr or 3.1
percent of station capacity; capital investment, $17.60/kW; and operating
costs, 2.0 mills/kWh. The 200 ppm concentration is representative of a coal-
fired source with combustion modification techniques applied or an oil-fired
source without supplementary NO controls applied. The estimates are for
A
oxidation of NO only. The energy requirements and cost of flue gas treatment
for control of N02 would be additive.
The final report on the RTI study, "Technology and Economics of Flue Gas
NO Oxidation by Ozone," will be available for distribution in early 1977.
A
NO Control Strategy Assessment
A
IERL-RTP contracted with Radian Corporation to determine the potential
effectiveness of applying NO controls to large stationary combustion sources.
/\
The Chicago Air Quality Control Region (AQCR) was selected for a modeling study
of emissions from point, area, and mobile sources to determine the relative
impact of each category on ambient NO concentrations.
A /
The calibrated dispersion model predictions of annual average concentra-
tions indicate that^ while the major point sources account for nearly 40 percent
of the total NOV emissions in Chicago, they account for less than 10 percent of
A
the ambient N02 levels. However, preliminary investigation of expected short-
term concentrations of total NO shows that major point sources may account for
A
as much as 80 percent of measured NO levels. Therefore, it appears that more
A
stringent NO control for large point sources may be required to meet a poten-
A
tial short-term N0? standard, but that more stringent control of NO emissions
C. A
from large point sources cannot be justified on the basis of the existing
annual average of N02 standard.
52
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As a result of these findings, the Chicago AQCR modeling study was ex-
panded to determine more adequately the short-term ambient N02 levels, to
project the annual and short-term NC^ concentrations to 1985, and to assess the
use of NO emission control by combustion modification and/or flue gas treat-
X
ment to attain or maintain compliance with possible NOp ambient short-term and
annual average standards.
In conjunction with the modeling study, Radian conducted a survey of
state-of-the-art of control techniques for the abatement of NOV emissions from
A
stationary combustion sources. In addition, a survey was made of the nation-
wide sources of NO , the factors affecting transport and transformation of NO
X A
in the atmosphere, and the environmental effects of NO and its various trans-
X
formations.
The results of these studies will be integrated into a comprehensive
picture to assist in assessing research, development, and demonstration needs.
It is anticipated that several reports will be published in 1977 as a result of
Radian's work, which will continue in support of the overall FGT program.
Japanese NO Control
X
A series of reports has been"planned to facilitate the transfer of information
on Japanese flue gas treatment technology for control of NOx and simultaneous
control of S0x~and NOX.
The reports are prepared"," through an IERL-RTP contract with PEDCo-Tnviron-
mental, by Dr. Jumpei Ando of Chuo University, Tokyo, Japan. The reports are
"S0? Abatement for Stationary Sources in Japan," EPA-600/2-76-013a, and "NO
^- X
Abatement for Stationary Sources in Japan," EPA-600/2-76-013b. The first set
of reports was published in January 1976 and an updated version is anticipated
to be released in January 1977.
Economic Assessments of NO,, FGT Processes
^ r J * .-. - • j^ _ i ii. ... .11
In a recently initiated project, the Tennessee Valley Authority (TVA),
through an interagency agreement, will develop comparative economics of NO FGT
A
emission control processes. The projects will involve performing technical
assessments, preliminary economic evaluations, and detailed cost analyses of
selected NO abatement processes.
A
In Phase I, TVA will select the promising N0¥ control processes for pre-
A
liminary economic evaluations. This will involve a general technical assessment
of the feasibility of the process being developed and implemented in the U.S.
53
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In Phase II, preliminary economic appraisals will be developed for four
to eight of the most promising processes. In Phase III, detailed economic
projections of four promising processes will be completed.
The project is scheduled for completion in mid-1978. The overall project
will be cofunded by IERL-RTP and the Electric Power Research Institute.
EXPERIMENTAL PROJECTS
Catalytic Reduction of NO with Ammonia
/\
In 1973, an IERL-RTP contract was awarded to Environics, Inc., to pursue
the development and demonstration of selective catalytic reduction of NO
' . X\
emissions with ammonia over a platinum catalyst.'
A utility pilot plant treating a slipstream from an operating electric .:
utility boiler, equivalent to approximately 1.5 MW output, was designed,
installed, and tested with gas firing and with oil firing. Laboratory pilot-
plant testing was also conducted to supplement the utility pilot-plant testing.
Results of operating the utility pi!6t plant on gas firing, together with
results of the laboratory pilot-plant testing, indicated that the catalytic
reduction system provided 85 to 90 percent NOV removal with no significant
1 . A
loss 'of performance. Results of operating the utility pilot plant on oil
firing, together with results of laboratory pilot-plant oil-fired testing,
indicated that this system could provide at least 65 percent NO removal.
J\
A preliminary cost estimate indicates that a full-scale system would
require a capital expenditure of less than $11 per kilowatt of plant capacity,
with an operating expenditure of less than 0.2 mills per kilowatt-hour. These
estimates were based on 1974 dollars and a gas-fired 480 MW plant.
A final report is available on the Environics work, entitled "Catalytic
Reduction of Nitrogen Oxides with Ammonia: Utility Pilot Plant Operation,"
EPA-600/7-76-031.
Planned Pilot and Prototype Plants
The experimental program is slowly progressing toward full-scale demon-
stration of NO FGT technology by the early- to mid-19801s. The next phase of
/\
this program will be the demonstration of FGT processes at the pilot- and
prototype-scale. IERL-RTP has outstanding a request for proposal for these
pilot or prototype plants. It is contemplated that two contracts will result
from this procurement process. One will be for removal of NO only with
/\
either high- or low-SO concentrations, and the other will be for simultaneous
/\ .'
removal of NOV and S0~. The actual number arid size of orojects to be undertaKer
A ' C. '', '
will depend on budgetary constraints and availability of cost-sharing funds
from industry.
54
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The pilot plants must treat a flue gas volume equivalent to 0.5 MW. The
minimum acceptable NOV removal efficiency is 90 percent for the NO -only plant
X A
and 90 percent for both S0~ and NOV for the simultaneous plant. Proposals
L~ A
must contain both a host site -and a control process. The desired fuel for the
host site is coal. Proposals must be submitted to EPA by January 17, 1977.
It is anticipated contracts will be awarded by June 1977. The pilot- or proto-
type-plant projects will each consist of a 24 month program which will be
conducted in four phases. Phase I includes the preparation of a detailed
process design and an estimation of capital and operating costs for the oilot
plant. Following erection and mechanical acceptance test of the pilot plant
in Phase II, the contractor will perform system start-up and debugging, param-
etric testing, and optimization testing over a wide range of flue gas con-
ditions during Phase III. Phase IV provides for duration testing and evalua-
tion of the plant during 90 days of continuous operation.
It is currently anticipated that final reports will be published on the
results of the pilot- or prototype-plant operations in early 1980. A project
manual conveying the total concept of the proposed plant will be published in
late 1977 or early 1978.
There is the possibility of an additional experimental project being
initiated in 1977 with the Tennessee Valley Authority. The IERL-RTP experi-
mental projects in the NOV F6T area are predicated on substantial cost sharing
A
funds from industry.
EMISSIONS/EFFLUENT TECHNOLOGY
Flue Gas Desulfurization—Nonregenerable Processes
LIME/LIMESTONE WET SCRUBBING
These processes involve the wet scrubbing of fossil-fuel boiler flue gas
(from power plant or industrial/commercial sources) with limestone or lime
slurries to remove sulfur oxide and particulate pollutants. Results of many
studies, ranging in size from pilot- to full-scale, indicate that the processes
are capable of high pollutant removal efficiencies with acceptable reliability.
IERL-RTP is suppprting several lime/limestone research, development:, and
demonstration programs. A test program is being conducted, using two parallel
multiple-configuration 10 MW prototype units at TVA's Shawnee power plant.
This program is being supplemented by an IERL-RTP inhouse pilot plant, located
at Research Triangle Park, N.C. A program involving carbide and commercial
lime scrubbing tests and an evaluation of scrubber waste treatment disposal
55
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options is discussed later, under Waste and Water Pollution Control. Under an
interagency agreement with the U.S. Air Force, IERL-RTP is funding a compre-
hensive test program to characterize the Swedish Bahco lime scrubbing process
installed at Rickenbacker Air Force Base, near Columbus, Ohio, to handle up to
seven coal-fired heating boilers. The Bahco test program began early in 1976.
A competitive procurement has also been initiated to select a contractor for a
comprehensive stack gas reheat assessment study to determine the present
status of reheat technology, what factors have influenced selection of type
and degree of reheat applied, performance of existing equipment, and to make
an assessment of the actual need for reheat under various combinations of
factors such as weather, type of FGD system, and ground level air pollutant
concentrations. ,
Lime/limestone wet scrubbing processes have the inherent advantages of
low reactant costs, relative simplicity, and final products in the form of
relatively inert disposable materials. These processes are widely applicable
to both old and new power plants and to the smaller industrial applications.
Process disadvantages include: requirements for plume reheat, potential
reliability problems (e.g., scaling and erosion), and potential solids disposal
problems in some urban locations. These problems are being investigated in
the various IERL-RTP lime/limestone projects.
TVA's Shawnee Power Plant
Construction of the prototype facility at TVA's Shawnee power plant was
completed in March 1972; testing started the next month. The facility, con-
sisting of three different (but parallel) scrubber circuits, can handle about
90,000 cfm (30 MW equivalent) of the output of one of the ten coal-fired
Shawnee boilers. The versatile facility is being used to evaluate the per-
formance and reliability characteristics of lime/limestone wet scrubbing
systems under a variety of operating conditions.
The original test program included short-term (less than a day) factorial
tests, longer-term (2 to 3 week) reliability verification tests, and long-term
(2 to 6 month) reliability demonstration tests—with both lime and limestone.
This phase of the test program was completed in May 1974 and the results were
reported periodically: two topical reports (published in August 1973 and
January 1974), a December 1973 industry briefing, and a summary of testing
through October 1974 (published in June 1975).
56
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The original test program has been extended for at least 3 more years to
provide additional information and to improve the reliability and process
economics of the lime/limestone systems. The extended test program is also
expected to produce: a design and economics computer program to assist users
in studying and selecting a scrubber process for their particular application;
field evaluation of alternate methods (including chemical fixation) for dis-
posal of the sludge produced by the lime/limestone systems; and a larger-scale
study of some of the advanced scrubbing concepts which have shown promise
during tests at lERL-RTP's Research Triangle Park pilot plant.
The results of the continuing work at Shawnee are being reoorted peri-
odically: two progress reports have been published (in September 1975 and in
September 1976); and industry briefings were held in September 1975 and in
October 1976.
Recent work at Shawnee has been very encouraging. The present mist
elimination systems are operating reliably and with high efficiencies.
Successful operation of the venturi/spray tower system was achieved at greater
than design gas velocities using both lime and limestone. The TCA system was
successfully operated using both limestone and lime at design gas rates and
without a wash tray. Variable load operation of the venturi/spray tower
scrubber with lime has also been demonstrated at Shawnee. For about 2 months,
scrubber variables were adjusted to follow boiler operation over a range of 60
to 150 MW with 1,200 to 4,500 ppm variations in inlet S02 concentration. Both
ranges are much more severe than expected in most commercial applications.
Operation of the scrubber was entirely satisfactory throughout the period.
Alkali utilization studies at Shawnee have shown: (1) use of three
stirred tanks in series to replace a single stirred reaction tank increased
limestone utilization by 10 to 15 percent; (2) operation at low inlet pH
(approximately 5.2 pH) can increase limestone utilization to over 90 percent
or roughly equivalent to that normally obtained using lime, but with a cor-
responding loss in S&2 removal efficiency (the loss in S02 removal efficiency
can be compensated for by operating at higher L/G ratios, higher pressure
drop, addition of MgO, or by using three stirred tanks in series); and most
importantly, (3) a correlation was shown between the alkali utilization and
reliable operation. At above 85 percent"alkali utilization there is a marked
reduction in the accumulation of soft mud-type solids, which was oarticularly
apparent in the mist eliminator area where only very infrequent intermittent
washing was required compared to continuous washing required at alkali utiliza-
tions below 85 percent. •
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MARBLE BED
SYSTEM
(FLOODED BED
OF MARBLES)
VENTURI /SPRAY
TOWER SYSTEM
TURBULENT
CONTACT
ABSORBER
(TCA)SYSTEM
(MOBILE BED OF
PLASTIC SPHERES)
Versatile lirne/limestone wet scrubbing demonstration at Shawnee plant.
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lERL-RTP's Pilot Plant
lERL-RTP's two model scrubbers (300 cfm each) have been operating at
IERL-RTP since October 1972, providing direct experimental support to the
larger prototype studies at TVA's Shawnee test facility. One lime- and one
limestone-fed scrubber, designed for maximum test flexibility, are operated
concurrently 24 hours a day. Each essential component of the complete closed-
loop scrubbing system is included in the layout: a three-stage TCA scrubber,
scrubber effluent hold tank, lime slaker, fans, thickeners, and rotary vacuum
filters. Their compactness permits material balances to be performed on each
component to determine the extent of all reactions occurring within it.
Operating variables are investigated over ranges that cannot be achieved (or
are not practical to attempt) in the larger units, such as operating without
chloride, without fly ash, and at varying inlet oxygen and sulfur dioxide
levels in the flue gas.
During 1976, the pilot-plant operation was focused upon the problem of
sludge and oxidation, which involves the conversion of calcium sulfite to
calcium sulfate (gypsum). The advantages of producing gypsum as the throwaway
product of FGD scrubbers derive from the improved physical properties of the
solid and its chemical inertness. The physical properties of gypsum associated
with its large crystal structure led to faster settTirig, better filterability,
and reduced sludge volume. Theoretically, a total reduction of about 47
percent in total waste production is possible as a result of the change in
physical properties brought about by oxidation to gypsum. In addition, it is
expected that the oxidized sludge will meet the requirements for direct dis-
posal as landfill, thus avoiding the necessity of chemical fixation.
The results of the pilot-plant investigations over the past year have
demonstrated that the conversion to gypsum can be made efficiently and com-
pletely at operating conditions that are realistic'for full-scale application.
Excellent results were achieved in both two-stage and single-stage scrubber
designs, both of which were shown to be capable of obtaining high S02 removal
efficiency and high limestone utilization concurrently with complete oxidation
of the sludge. By accomplishing the oxidation in a single-stage scrubber, it
was shown that the process will be applicable to systems now in operation
without extensive modification.
The key to good oxidation was shown to lie in the efficient transfer of
oxygen from the injected air. This transfer was maximized in shallow tanks by
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SCRUBBER
EFFLUENT
HOLD TANK I
IERL-RTP lime/limestone scrubber pilot plant.
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the use of a jet aspirator/ejector for aerating the holding tank. Alterna-
tively, it was shown that the required transfer efficiency can be obtained
with an air sparged tower. The use of a tall tower which combines the func-
tions of the holding tank and oxidizer should provide maximum overall ef-
ficiency with minimum operating power.
These tests have further shown that the high limestone utilizations (85
percent) required for eliminating demister fouling—which has been the prin-
cipal restraint on reliable operation in the past—can be maintained while
forcing oxidation to gypsum, without loss of SOp removal efficiency.
The pilot-plant studies of forced oxidation, which were conducted in
preparation for large-scale testing in the Shawnee prototype scrubber, thus
indicate that very significant improvements in the performance of limestone
FGD systems can be expected, both from the operating and the environmental
viewpoints.
Bahco Process
In 1971, Research-Cottrell, Inc., was licensed by A. B. Bahco of Sweden
to test, refine, and offer the Bahco lime scrubber commercially in the United
States. The process generally consists of a mechanical particulate removal
system followed by a unique, two-step, vertical scrubbing tower for sulfur
dioxide removal.
The Bahco system is currently offered in sizes up to about 40 MW, which
makes it applicable to many industrial-sized boilers throughout the United
States. Because most of the engineering on the Bahco scrubber is complete (it
is offered in several standard sizes), installation costs make the system a
reasonable alternative to low-sulfur fuels for industrial boiler applications.
There are about 20 Bahco scrubbers in operation in Sweden and Japan;
however, the installation at Rickenbacker Air Force Base, Ohio, is the first
in the United States, and the first on a coal-fired application anywhere. The
Bahco scrubber at Rickenbacker AFB is designed to handle the flue gas from up
to seven coal-fired heating boilers equivalent to about 3 MW each (or a maxi-
mum total of 21 MW). The IERL-RTP sponsored test program was begun early in
1976 and the preliminary results appear promising.
DOUBLE ALKALI
The double-alkali process, like the lime/limestone wet scrubbing proc-
esses, produces a throwaway product consisting of fly ash and calcium sulfite/
sulfate. The process, in its various forms, was developed in an effort to
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avoid the problems associated with the use of absorbent slurries in the
lime/limestone processes.
Flue gases are scrubbed, using a soluble alkali (usually sodium-based)
solution as the absorbent. The spent absorbent solution is treated with lime
and/or limestone in a regeneration system to produce a regenerated soluble
alkali for recycle to the scrubber system and a throwaway product for disposal.
Although less developed than lime/limestone wet scrubbing processes,
double-alkali systems show potential for attaining high sulfur oxide removal
efficiency and good reliability at relatively low cost.
Technology Development
The development of double-alkali technology by IERL-RTP has followed an
orderly, progressive pattern. After initial inhouse engineering feasibility
studies and laboratory experiments in 1971 and 1972, IERL-RTP contracted with
Arthur D. Little, Inc., in May 1973 to conduct a laboratory- and pilot-plant
study of various double-alkali modes of operation. In early 1975 the project
was expanded to include a prototype test at the 20 MW facility installed at
the Scholz plant of Gulf Power Company by Southern Company and constructed by
Combustion Equipment Associates. The total funding for the expanded contract
was $1,169,000. In late 1976, EPA contracted for a full-scale utility demon-
stration of the process.
Work in the laboratory and pilot plant included the study of "dilute" and
"concentrated" systems, lime and limestone regeneration, sulfuric acid addi-
tion for sulfate removal and solids characterization. Prototype testing at
the Scholz station lasted from February 1975 to July 1976, with the EPA-
sponsored portion of testing beginning in May 1975. As a whole, the prototype
system performed very well and indicated that a double-alkali system would be
a viable flue gas desulfurization system for coal-burning utilities. During
the entire program of approximately 17 months, the system showed availability
to the boiler of 72 percent; however, during three specific operating periods
of approximately 4 months each, the system showed availability of 90 percent.
Sulfur dioxide removal was generally in the range of 90 to 99 percent.
A two-volume report on the entire laboratory, pilot-plant and prototype
development study conducted by A. D. Little, Inc., for IERL-RTP will be issued
in early 1977.
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CTl
OJ
Three 20 MW prototype FGD systems at Gulf Power's Scholz plant.
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General Motors Industrial Boiler Demonstration
General Motors and IERL-RTP participated in a cooperative program to
demonstrate, test, characterize and evaluate GM's "dilute" mode double-alkali
system for flue gas desulfurization of emissions from coal-fired industrial
boilers. The program was conducted at GM's industrial boiler complex in
Parma, Ohio. The system, consisting of four coal-fired boilers having a
steaming capacity of 320,000 Ibs per hour (equivalent to 32 MW electric
generating capacity), was constructed and operated by GM. The construction
cost amounted to approximately $3.5 million. Arthur D. Little, Inc., designed
and conducted the test program to evaluate the system with funding from IERL-
RTP. The program consisted of three 1 month intensive test periods and
longer term nonintensive testing. The FGD system tested consisted of four
valve tray scrubbers, each with three trays and a mesh demister. Each of the
intensive tests evaluated a slightly different flow scheme. In the third and
best scheme, the system achieved 90 percent S02 removal, with a lime stoichi-
ometry of 1.3, and produced a semi-solid waste product containing 56 percent
total solids. The testing took place during the period of August 1974 to May
1976, with an overall scrubber availability to the boilers of about 78 per-
cent, excluding four long-term planned shutdowns for system modifications.
A report on the entire test program will be issued by IERL-RTP in late
1976 or early 1977.
Full-Scale Utility Demonstration
In September 1976, IERL-RTP contracted with Louisville Gas & Electric
Company for a cost-shared, full-scale coal-fired utility demonstration of the
double-alkali process at the 280 MW Cane Run #6 boiler. The entire project is
estimated to cost in excess of $20 million with EPA's share being $4.5 million.
The demonstration project consists of four phases: (1) design and cost
estimation; (2) engineering design, construction and mechanical testing; (3)
start-up and performance testing; and (4) 1 year of operation and long-term
testing. Proposals are currently being evaluated to establish a contract with
an independent company to design and conduct the test program.
Phases 1 and 2 are presently being conducted concurrently. Construction
is expected to be complete by the end of 1978, and testing will begin in early.
1979. System performance guarantees have been established and are backed
financially by the system designer/constructor, Combustion Equipment Associates,
Guarantees are in force on S02 removalj sodium consumption, calcium consump-
tion, energy consumption and system availability.
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SURVEY OF FGD SYSTEMS
IERL-RTP has contracted with PEDCo-Environmental to survey flue gas
desulfurization (FGD) systems which are operational, under construction, or
planned in the United States and Japan. The survey is being conducted using
plant visits and a comprehensive questionnaire. Through December 1975, 11
systems had been visited and detailed reports issued concerning their opera-
tion. This survey is to continue, with emphasis on those systems which have
significance with respect to FGD in the United States. Both new installations
and some previously visited ones have been included in site visits made during
1976. Reports on these site visits are being prepared.
In addition to detailed technical reports, giving results of the visits,
PEDCo is providing bimonthly status reports indicating the number of each type
of sulfur dioxide control system in operation, under construction, or planned
in the United States, and the MW capacity controlled or to be controlled. As
of November 1976, 120 such systems are planned to control over 46,000 MW of
electrical generating capacity.
A survey of Japanese installations and of their operating experiences,
problems, and solutions is being conducted, under subcontract, by Dr. Jumpei
Ando of Chuo University in Tokyo.
Flue Gas Desulfurization—Waste and Water Pollution Control
lERL-RTP's flue gas cleaning (FGC) waste and water pollution control
program is a continuation and expansion of modest efforts initiated by the
Laboratory in the late 1960's. It is aimed at the development, demonstration,
and recommendation of environmentally acceptable, cost-effective techniques for
disposal/utilization of FGC wastes, and for maximizing power plant water
recycle/reuse. The theme of each of the 12 IERL-RTP program projects, de-
scribed below, is in one of three categories: FGC Waste Disposal Methods, FGC
Waste Utilization, and Power Plant Water Reuse. (Four FGC Waste Disposal
Methods projects—other than those described below—are being conducted by
EPA's Municipal Environmental Research Laboratory in Cincinnati; results of
the Cincinnati projects are being coordinated with those described below.)
FGC WASTE DISPOSAL METHODS
FGC Waste Characterization, Disposal Evaluation, and Transfer of FGC
Waste Disposal Technology
Since late 1972, Aerospace Corporation, under contract with IERL-RTP, has
been conducting a broad-based study to: (1) identify environmental problems
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associated with F6C waste disposal; (2) assess current FGC waste disposal
methods, including feasibility, performance, and costs; (3) make recommenda-
tions regarding alternate disposal approaches; and (4) assemble, assess, and
report all FGC waste-related research and development activities in EPA, TVA,
and private industry. This project is the key effort in lERL-RTP's program
for waste and water pollution control.
Shawnee FGD Waste Disposal Field Evaluation
Under this program, initiated by IERL-RTP in 1974, the Chemfix, Dravo,
and IUCS processes for chemical fixation of scrubber wastes are being evaluated
in three separate impoundments. (See photo of one of the impoundments, below.)
As an alternative approach, ash-free lime and limestone wastes have been
further "dewatered" by the addition of dry fly ash and placed in two additional
impoundments which have underdrainage systems for dewatering and stabiliza-
tion. Untreated/unstabilized lime and limestone wastes are placed in two
additional impoundments (for a total of seven). Leachate, runoff, and ground
water samples (as well as core samples of the wastes and soil) are being
collected and analyzed to evaluate environmental effects. The final impound-
ment will involve evaluation of oxidized sulfite waste (gypsum) disposal.
Louisville Gas and Electric Evaluation of FGD Waste Disposal Options
Louisville Gas and Electric Company, under contract with IERL-RTP, is
currently conducting a program of carbide and commercial lime scrubbing tests
and an extensive evaluation of scrubber waste treatment/disposal options.
Laboratory studies of nonchemical and chemical (fixation) processes for sta-
bilization of scrubber sludge are being conducted and samples will be mixed
with fly ash alone or fly ash and one of several additives (e.g., lime). The
field studies consist of small-scale impoundment tests and larger-scale (about
76 cubic meter) landfill tests in which leachate migration, runoff, and phys-
ical stability tests of unstabilized and stabilized waste material will be
conducted.
Lime/Limestone Scrubbing Waste Characterization
This project, funded by IERL-RTP, involves the physical and chemical
characterization of lime/limestone waste solids as a function of scrubber
operating conditions. Under these studies, lime/limestone scrubbing waste
materials from the Shawnee facility are being characterized and an attempt is
being made to correlate the properties with the scrubber operating conditions.
If feasible, a means of controlling waste characteristics to improve disposal
or utilization economics will be recommended.
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en
Test pond for disposal of Shawnee's chemically treated scrubber waste.
-------
Dewatering Principles and Equipment Design Studies
This project is being conducted under an IERL-RTP grant by Auburn Uni-
versity. It consists of the following efforts to improve the performance of
current FGC waste dewatering equipment: (1) an examination of current de- ','.
watering equipment design principles to determine their applicability to FGC
wastes; (2) laboratory settling and other tests to determine the physical
properties and behavior of FGC wastes as a basis for dewatering equipment
design studies; (3) analytical design studies to develop dewatering equipment
designs based on FGC waste physical properties and behavior (these efforts
will continue and will be updated based on subsequent bench-scale testing);
and (4) laboratory tests of dewatering equipment design concepts. This project
offers the potential of cost savings through reduction in the size of dewatering
equipment and the volume of the disposal site, as well as through reduction in
the amount of chemical fixation additive (if used) required.
Characterization of Effluents from Coal-Fired Power Plants
This IERL-RTP sponsored project involves TVA efforts to: (1) characterize
and quantify the chemical parameters of coal pile drainage; (2) assess and
quantify the chemical and physical composition of ash pond effluent after
adjustment of pH to meet effluent standards; (3) evaluate an ash pond monitor-
ing program to determine the sampling and analyses necessary to obtain repre-
sentative information; (4) assess, characterize, and quantify the effects of
coal ash leachate on ground water quality; and (5) evaluate and quantify the
chlorinated effluent in the discharge canal from once-through cooling systems.
Information from this project will be supplemented by the fly ash charac-
terization efforts described belcw.
Ash Characterization and Disposal
This IERL-RTP project involves TVA efforts to: (1) summarize and eval-
uate existing data on the characteristics of coal ash and ash effluents from ,
inhouse TVA studies and from studies made by other organizations (this effort
is now complete); (2) perform chemical and physical analyses on coal, coal
ashes, and ash effluents to obtain a complete characterization of these ma-
terials as a function of variation in boiler design and operation, as well as
coal type; (3) evaluate various methods for disposal and utilization of fly
ash; (4) summarize information on methods of ash sluice water treatment for
reuse; (5) conduct conceptual design studies of dry and wet ash handling
systems; and (6) recommend the most promising systems for ash handling and
disposal/utilization.
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Alternative Methods for Lime/Limestone Scrubbing Waste Disposal
This project is one of several tasks which make up the economic studies
of majori FGD processes being conducted by IERL-RTP. Several FGD waste dis-
posal methods and FGD system design and operating premises have been selected
for a detailed economic evaluation of FGD waste disposal; these include chemi-
cal fixation via the Chemfix, Dravo, and IUCS processes. The final report on
this effort should be issued in the spring of 1977.
Alternative FGC Waste Disposal Sites
This lERL-RTP-sponsored project is being conducted to identify, assess,
and demonstrate on a pilot scale, alternate FGC waste disposal methods (other
than local ponding and landfilling). The demonstration is to be limited to
coal mine and ocean disposal.
Although environmental effects and operational safety will be the major
initial considerations, the assessment will also include a study of the eco-
nomics of the alternate disposal methods, as well as a study of applicable
Federal and state regulations. Recommendations and conceptual designs for the
pilot demonstrations will be based on all of the initial efforts. A prelim-
inary assessment has been completed; the final assessment effort will be
completed by mid-1977.
FGC WASTE UTILIZATION
Lime/Limestone Scrubbing Waste Conversion Pilot Studies
In a cost-shared contract to conduct pilot studies of two key process
steps in M. W. Kellogg Co.'s "Kel-S" process for conversion of lime/limestone
scrubbing waste to elemental sulfur with recovery of the calcium in the waste
as calcium carbonate, design data are being generated to allow scale-up to a
large (prototype) test unit for a power plant.
Gypsum By-product Marketing
This project is one of several tasks which make up the FGD by-product
"marketing studies being conducted by TVA for IERL-RTP. A preliminary study
conducted by TVA during early 1974 indicated the possibility that production
and sale of abatement gypsum might offer a substantial economic advantage over
FGD waste disposal. These new studies include a thorough economic evaluation
of gypsum producing processes (e.g., Chiyoda, carbon absorption, CaS03 oxida-
tion) and a detailed U.S. marketing study of abatement gypsum for wall board.
Use of FGD Gypsum in Portland Cement Manufacture
This project, which is being negotiated by IERL-RTP with the S.C. Public
Service Authority (with Santee Portland Cement Corporation and Babcock and
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Wilcox as subcontractors), will consist of the following efforts: (1) pre-
liminary surveys of U.S. industry to determine the quantity of FGD gypsum
which could be used in Pbrtland cement manufacture; (2) collection and iden-
tification of waste samples from several FGD systems; (3) laboratory tests to
identify and solve problems associated with chemical and/or physical charac-
teristics of FGD gypsum in Portland cement manufacture; and (4) design and
estimation of costs of a pilot demonstration unit either at a power plant or a
cement plant, depending on the results of the laboratory tests.
Fertilizer Production Using Lime/Limestone Scrubbing Wastes
One of several tasks being conducted by TVA under an interagency agree-
ment with IERL-RTP involves the use of lime/limestone scrubbing wastes as a
filler material and as a source of sulfur in fertilizer. This study is a
continuation and expansion of previous bench-scale laboratory production tests
and small field plot application tests with rye grass. In the proposed process,
phospheric acid and ammonia are the phosphate and nitrogen sources. Most of
the development work has centered around avoiding losses of sulfur and/or
ammonia in the fertilizer reactor.
FGD Waste/Fly Ash Beneficiation Studies
This IERL-RTP-sponsored project will consist of the following efforts:
(1) a conceptual design/cost study of a TRW-conceived, proprietary process
(for which two related patents have been issued) for producing sulfur, alumina,
and dicalcium silicate for FGD waste and fly ash (and/or clay), including the
development of a preliminary process design (including material and energy
balances) and an estimate of capital and operating costs to determine the
economic viability of the process; (2) if the economics of the process appear
favorable, a bench-scale laboratory investigation to determine probable ranges
of operating conditions for each of the major processing steps (reduction,
calcination, leaching, separation) and to determine (with actual FGD waste)
probable yields and purity of products; (3) assuming the process still appears
viable, possible pilot-scale testing of the process steps to obtain design
data for large-scale equipment. Reports will be issued after each of the
efforts described above.
The conceptual design/cost study was recently completed; TVA is assisting
in a review of the final report. The bench-scale tests should be initiated in
1977.
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POWER PLANT WATER REUSE
Alternatives for Power Plant Water Recycle/Reuse
This IERL-RTP sponsored study, with Radian Corporation, is designed to
develop methods for minimizing water use and wastewater discharges from coal-
fired steam-electric power plants. The study consists of six tasks: (1)
selection and characterization of five specific power plants; (2) preparation
of computer models to simulate makeup, process, and effluent water streams, as
well as chemical equilibria of the processes for each plant selected; (3)
verification of process computer models by comparing existing plant chemical
and operating data with data predicted by the models; (4) formulation of
several water recycle/reuse options to minimize plant water requirements and
discharges for the specific plants selected for study; and evaluation of at
least one option (via process simulation) for each plant; (5) preparation of
capital and operating cost estimates for each viable water recycle/reuse
option; and (6) detailed presentation of program results, including recommen-
dations of the recycle/reuse options to be used at each of the plants studied.
The first four tasks have been completed for three plants; the study should be
completed by mid-1977. Future plans include pilot plant testing of one or
more of the recycle/reuse options.
Treatment of Flue Gas Scrubber Waste Streams with Vapor Compression
Cycle Evaporation
This lERL-RTP-sponsored pilot demonstration, using the Resources Conser-
vation Company's brine concentrator, is being conducted at Gulf Power Company's
Scholz power station. The brine concentrator is a 6,000 gal./day unit which
isi being tested for 90 days on a waste stream from a Chiyoda FGD system. A
report on the demonstration will be issued in mid-1977.
Thermal Pollution Control
Thermal pollution control programs of IERL-RTP are divided into two broad
areas: cooling technology, and waste heat utilization. Cooling technology
programs include studies of cooling system economics, advanced heat rejection
techniques, and development of control technology for the treatment and pos-
sible reuse/recycle of cooling effluent streams. Waste heat utilization
programs currently involve agricultural applications, although promising
residential/industrial and aquacultural uses of waste heat are also of interest.
The transfer of technology is an objective of programs in both areas as ex-
emplified by present support; for a state-of-the-art manual in thermal pollu-
tion control technology and a 1977 conference on waste heat management and
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utilization. The following sections describe significant programs under these
two broad areas.
COOLING TECHNOLOGY
During the past year IERL-RTP supported several studies on cooling system
performance and economics. The objectives of each included the definition of
costs and other penalties for steam-generated electrical power and the examina-
tion of environmental factors, such as water consumption, drift, and fogging, .
which impact on the various types of cooling devices.
In one lERL-RTP-sponsored supported study, a computer program for optimiz-
ing the design of large, dry cooling systems was developed. Program variables
included: heat exchanger design parameters (tube length, bundle width, number
of tube rows and tube passes); type of condenser (spray or surface), type of
turbine (conventional or modified for high back pressure); climatic factors;
and cost factors (fuel, fixed charges, lost capacity, auxiliary power). The
resultant program is being used to optimize the cost of power generation for
various practical combinations of program variables.
Two important factors in power plant siting and cooling system selection
are consumptive water use and vapor plume emissions. The use of evaporative,
or wet, cooling towers may impact adversely on both of these factors. Hence,
an lERL-RTP-supported project studied the feasibility of using combined wet/
dry cooling towers for conserving water and abating vapor plume emissions.
Since increasing the dry heat exchanger surface area reduces both water con-
sumption and water content in tower plumes but increases capital and operating
costs while converse trends are evident when evaporative heat exchangers are
used, these studies entailed various wet/dry heat exchanger combinations for
cooling towers situated at ten U.S. sites. Six of these studies were aimed at
minimizing water use in the arid but coal-rich western region, while the
remaining studies were directed toward vapor plume abatement at urban sites.
A sensitivity analysis for Casper, Wyoming, a representative site having
limited water but extensive coal and energy development, is also a program
output.
In a 4 year project scheduled for completion in 1980, IERL-RTP is
participating with the Town of Braintree, Massachusetts, in a dry cooling
tower demonstration and performance study. Specific objectives of this proj-
ect involving a combined cycle plant (60 MW gas turbine/25 MW steam turbine
with a direct condenser) include the measurement of steam flow distribution
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and temperatures for better definition of optimal design conditions, the
assessment of meteorological effects from the plant and of .meteorological
factors on plant performance, the monitoring of .noise and control, air quality
considerations on or from the plant, and the economic effect of design and
operational factors. Test instrumentation has been obtained and will be
installed prior to the start-up of the plant which is now projected for late
January 1977.
IERL-RTP is continuing control technology development for the treatment .
of wastewater streams inherent in evaporative cooling systems. With IERL-RTP
support, the University of California has developed a system for renovating
cooling tower blowdown for recycle or reuse which requires substantially less
capital and operating costs compared to the best systems in current usage.
This new system uses vertical tube (VT) evaporation with interface enhancement
to attain a higher heat transfer performance. In a test facility using a
5,000 gpd VT evaporator-crystal!izer in the downflow mode and using a low
temperature (125°F) to simulate the use of waste heat from a conventional
power plant cooling cycle, sodium sulfate was crystallized and cooling tower
blowdown from the Mohave plant was reduced to a 30-fold concentrate, and
system feasibility was demonstrated. The evaporator-crystal 1izer was also
operated with a vapor compressor in the evaporation temperature range of 215
to 224°F in tests for concentrating saline agricultural drainage and indus-
trial cooling tower blowdown. Comparison of results for the conventional and
interface-enhanced modes of operation from these tests showed that in each
case interface enhancement resulted in better heat transfer performance of the
evaporator-crystal!izer while its energy requirements were simultaneously
reduced.
Since the biofouling of condenser tubes reduces heat transfer while
conventional chlorination of cooling water to combat biofouling may have
adverse impacts on biota, IERL-RTP is seeking viable alternatives to chlorina-
tion. The findings of an lERL-RTP-supported study concluded that more ef-
ficient methods of chlorine application are available than are currently being
used; most alternative chemicals studied (bromine chloride, ozone, chlorine
dioxide) may have reduced ecological effects but are more expensive; mechanical
tube cleaning techniques may require complementary chemical treatment of
cooling water and some mechanical techniques may not be retrofitted; controlled-
release antifoulants coated on or embedded in heat transfer surfaces, while
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promising, require considerable development; and radiation techniques are not
expected to be cost-effective unless the use of nuclear waste is feasible.
IERL-RTP and TVA cooperation in thermal pollution control is evidenced by
several programs. With IERL-RTP financial support TVA is assessing methods
for cooling tower blowdown and wastewater treatment and developing cooling
water intake structures which reduce harmful effects to fish. The water
treatment methodology study involves evaluation of reverse osmosis and ultra-
filtration systems supplied by vendors. These tests use effluents supplied
from various fossil-fueled power plants, the wastewater consisting of ash pond
discharge, cooling tower blowdown, boiler blowdown and SC^ scrubber slurry
waste streams. For different membranes, the data will be used to design and
operate experimental treatment facilities with the aim of minimizing treatment
costs. Results of tests in these facilities will be evaluated to determine
the economic and technical feasibility of the prototype systems.
*A review of cooling water intake structure technology has been completed
by TVA. With continued IERL-RTP support, TVA is planning detailed testing of
one or more screen devices in addition to continued evaluation of a fish
removal pump.
WASTE HEAT UTILIZATION
The beneficial use of warmed condenser coolant can alleviate or reduce
thermal pollution problems, lead to secondary profits, and promote energy
conservation since waste heat will be constructively used. IERL-RTP continued
its support of a Northern States Power Company/University of Minnesota demon-
stration of waste heat utilization in a greenhouse operation. During 1976 the
first and second crops were planted and harvested, the second crop making use
of waste heat from condenser cooling water after connection of the half acre
greenhouse to the power plant cooling system in the late summer. Using waste
heat for both soil warming and air heating, both vegetables (tomatoes, peppers,
lettuce) and flowers (roses, snapdragons) were grown.
In another cooperative effort between IERL-RTP and TVA, soil wanning
experiments will be performed by TVA in a program aimed at extending the crop
growing season. Different pipe sizes (2.5 and 5 cm diameter), materials
(copper and polyethylene), and lateral spacings (90, 180, and 360 cm) were
studied. Based on heat dissipation rate tests, the smaller polyethylene pipe
with a spacing of 180 cm (with plant rows spaced 45 cm on each side of the
heated pipe) was found to be the best economic arrangement. The monitoring of
soil temperatures also indicated that the pipes should be placed as close to
74
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the surface as possible while avoiding damage from tilling operations. This
program is a continuing study with the objective of determining the feasi-
bility of using waste heat for1optimizing the recycling of nutrients from
livestock wastes into protein for animal and/or human feed supplement.
PARTICULATE TECHNOLOGY
Fine particulates are a health hazard because, in contrast to coarse
particles, they can bypass the body's respiratory filters and penetrate deep
into the lungs. Fine particles released into the atmosphere remain airborne
for extended periods of time, obstruct light, and cause limited visibility
typical of air pollution haze and smog. They have been identified as trans-
port vehicles for gaseous pollutants. The health hazards of fine particulates
are intensified by the tendency of metallic materials from high-temperature
processes, such as pyrometallurgical and combustion processes, to condense as
chemically and catalytically active fine particulates. Many toxic and poten-
tially hazardous compounds are also emitted as fine particulate. Particulate
matter formed in the atmosphere from the reaction and condensation of reac-
tions makes it difficult to relate atmospheric particulate pollution levels to
specific sources. This has hampered the development of effective control
strategies and the establishment of meaningful emission standards. The control
of these secondary forms of particulate must be through control of their
precursors, and primary particulate does play an important role in the forma-
tion cycle.
Many years will be required to develop a sound data base to quantify the
health effects problem of fine particulates. Sufficient information does
exist, however, to conclude that fine particles must be controlled if public
health is to be protected.
EPA has established a goal of setting fine particulate standards. To
develop these standards, research and development is necessary to provide a
minimum data base. This data base and the necessary adequate control tech-
nology do not now exist.
It is currently lERL-RTP's responsibility to develop and demonstrate, on
a pilot scale, control technology which is generally applicable to particulate
and fine particulate matter emitted from all stationary sources. For the past
4 years, the Laboratory's Particulate Technology Branch (PATB) has been
engaged in a program aimed at determining the limitations of conventional
particulate control devices and defining a research and development program
which will eventually produce the needed technology for the control of fine
particulate matter.
75
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lERL-RTP's Particulate Program
In order to pursue the goal of developing control technology for fine
particulate emissions, the basic IERL-RTP program in this area has been
i
divided into seven major areas:
0 Measurement.
0 Characterization and improvement of conventional control equipment
and assessment of the collectability of dusts.
0 New particulate control technology development.
0 New idea evaluation and identification.
0 Fine particulate control for combustion processes utilizing low-sulfur
coal.
0 High-temperature/high-pressure particulate control.
0 Accelerated pilot demonstrations.
MEASUREMENT
The principal goals of this effort are to: (1) select, calibrate, and
standardize measurement equipment and procedures to be used in support of the
entire particulate control program; and (2) develop instruments capable of
determining efficiencies of control equipment oh particle size fractions on a
real time basis.
CHARACTERIZATION AND IMPROVEMENT OF CONVENTIONAL CONTROL EQUIPMENT AND
ASSESSMENT OF THE COLLECTABILITY OF DUSTS
It is the aim of this program area to: (1) ascertain, using the best
available conventional equipment operating on real sources, the actual control
capability in terms of size fractional efficiency; (2) develop a data base for
decisions and judgments with respect to the capability of commercially avail-
able control equipment; (3) develop improvements in conventional control
devices which will eliminate deficiencies in their potential for fine particle
control; and (4) determine the ease or difficulty with which any given indus-
trial dust pollutant may be collected. With the information collected in this
program area, it should be possible to predict with reasonable accuracy the
ease or difficulty of and the system required for control of almost any par-
ticulate problem.
NEW PARTICULATE CONTROL TECHNOLOGY DEVELOPMENT
The goals for this area are: (1) assess all potential collection mecha-
nisms; (2) initiate exploratory projects to evaluate feasibility of concepts
and/or mechanisms; and (3) develop pilot units for promising systems.
76
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NEW IDEA EVALUATION AND IDENTIFICATION
The goals of this program area are: (1) evaluate novel devices; (2)
generate a plan to solicit, stimulate, and identify new ideas and concepts for
fine particulate control; and (3) pilot-scale demonstration of the most promis-
ing devices.
FINE PARTICLE CONTROL FOR COMBUSTION PROCESSES UTILIZING LOW-SULFUR COAL
This represents a new program area added in FY 76 to provide solutions to
problems associated with the projected increase in the use of low-sulfur coal.
Major increases in the combustion of low-sulfur coal are expected both as a
result of increased power generation in the West and as a result of a switch
from high- to low- sulfur coal in the East to meet SOo emission standards
without using scrubbers. In general, combustion of low-sulfur coal produces a
fly ash with high electrical resistivity. This fly ash is difficult to collect
in electrostatic precipitators (ESPs) (the most common particulate control
device for utility boilers). Thus, use of low-sulfur coal, especially in
plants designed for high-sulfur coal, produces serious problems for achieving
adequate particulate and fine particulate control.
The goals of this new program area are:
0 determine the effects of flue gas and/or fly ash conditioning agents
on electrostatic precipitator performance and on overall pollutant
emissions.
0 develop and demonstrate an improved electrostatic precipitator which is
relatively insensitive to changes in fly ash physical and chemical
properties.
° demonstrate the feasibility of using fabric filters to control particulate
emissions from large utility boilers.
0 determine the impact of coal cleaning on ash collectibility.
0 demonstrate the use of environmentally acceptable conditioning agents
to improve particulate control by electrostatic precipitators.
In FY 76 IERL-RTP sponsored two conferences (one on the West coast and
one on the East coast) on the problems associated with combustion of low-
sulfur coal. One field evaluation of conditioning agents was also completed.
HIGH-TEMPERATURE/HIGH-PRESSURE PARTICULATE CONTROL
This program area was added in FY 75 as a result of the particulate
removal problems associated with advanced energy processes. Its goals are:
(1) for the near term, develop fundamental information on the mechanics of
77
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aerosols at high temperature and high pressure; (2) using this fundamental
information, choose the most promising collection mechanisms, and mount a
research and development effort aimed at exploiting these mechanisms; and (3)
develop the devices necessary to ensure the environmental acceptability of the
advanced energy systems.
Current Program Status
MEASUREMENT
Current devices used for measuring particle size on control equipment
include impactors, optical counters, diffusion batteries, and condensation
nuclei counters. These devices require lengthy manual techniques for opera-
tion, and their reliability is less than satisfactory. For instance, with
current measurement technology, it is not always possible to discern the
difference between a device collecting 90 percent of particles less than 0.5
microns in diameter and one collecting 95 percent or sometimes even 99 percent.
In order to maintain the momentum of control technology development, this
situation must be remedied.
The objective of this effort is to produce a device which will measure
fractional efficiencies of control devices in real time with a high degree of
precision and accuracy.
CHARACTERIZATION AND IMPROVEMENT OF CONVENTIONAL CONTROL EQUIPMENT
Electrostatic Precipitators
IERL-RTP has completed the total characterization of seven ESPs operating
on a number of sources ranging from power plants to aluminum plants. Data
from these tests clearly show that ESPs can collect particles of all sizes
with high efficiency when dust resistivity is not a problem. Data and theoret-
ic.al predictions indicate that high dust resistivity limits ESP performance.
IERL-RTP has completed work to determine the current conduction mechanisms
in fly ash at high temperatures (>300°F). This work is being extended to low
temperatures in an FY 75 funded program. One outcome of this work has been
the recognition of sodium as a potential conditioning agent to reduce resistivity.
IERL-RTP has evaluated and published reports on conditioning agents such as
S03 and NH3< Conditioning appears to be a possible solution to retrofit types
of problems, but not for new installations.
Specially designed charging or precharging sections are a possible means
of improving the collection of fine high resistivity particles. Fundamental
studies and limited pilot-plant work on fine particle charging, funded in FY
78
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74, demonstrated that the precharging concept is technically feasible. Follow-
on work is being conducted to reduce the concept to practice.
A mathematical model for the design of ESPs was completed in FY 75. This
model is in two forms: a design and selection manual for the plant engineer,
and a programmed computer version for the design engineer. The model predicts
well the performance of ESPs down to particle diameters approaching 0.01
microns. Programs currently underway will improve the model by better defin-
ing losses due to poor gas distribution or rapping and reentrainment. These
losses are currently handled in the model on an empirical basis.
Wet ESPs offer a solution to high resistivity and fine particle collection
problems from some sources. IERL-RTP is completing a systems study of wet
ESPs which was funded in FY 73. The results of this study indicate that wet
ESPs have performance characteristics similar to dry ESPs without the letter's
resistivity problems. However, cost and other factors limit the application
of wet ESPs. Wet ESPs do not appear to be a solution to the problem of col-
lecting high-resistivity fly ash. <
The broad objective of the ESP imorovement program is to develop an ESP
p
of moderate size (specific collection area < 300 ft /1000 acfm at 300°F) for
high- (>99 percent) efficiency collection of high-resistivity dusts. Such
ESPs would have a minimum particle collection efficiency of 90 percent at 0.5
micron particle diameter. This objective is shown in the chart below. High-
resistivity dusts are produced from several sources: the largest is combustion
of low-sulfur coal.
As shown below, moderate to small sized ESPs can collect particles with
high efficiency when the dust resistivity is not excessive. The figure also
shows that very large cold-side ESPs are required for efficient collection of
high-resistivity dusts. Hot-side ESPs are somewhat smaller, based on specific
collection area (SCA) for acfm than cold-side ESPs for high-resistivity dusts.
However, theoretically perfect (e.g., no reentrainment, no sneakage) hot-side
performance does not approach the actual performance of the cold-side low-
resistivity ESP. If the SCAs are converted to a common temperature, the hot-
side ESP is seen to be much less attractive than the ESP that would result
from successful completion of this effort. For example, a hot-side ESP with
good gas flow distribution and moderate-to-low sneakage and reentrainment has
an SCA of 450 ft2/1000 acfm at 700°F or 690 ft2/1000 cfm at 300°F. The
p
object ESP would require an SCA of only 180 ft /1000 cfm at 300°F for the same
efficiency.
79
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CAPITAL COST, $103/1000 acfm
7~8 10.4
15.6
99.9
COMPUTED PERFORMANCE
AT40NA/CM2
TEMPERATURE ~300°F
90
.200 300 _100L_
SPECIFTC COLLECTING AREA, Fl2/ 1000 acfm
Capital cost of ESP's vs. computed performance.
80
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Scrubbers
The Industrial Environmental Research Laboratory, Research Triangle Park,
has tested approximately ten scrubbers of conventional design on a variety of
particulate sources. In general, the performance or efficiency of a scrubber
drops off rather rapidly as the particle size decreases. Also efficiency is
directly related to the energy consumed by the scrubber.
The broad objective of the fine particle scrubber program is to develop
low pressure drop (30 to 50 cm H20) scrubber systems capable of collecting at
least 90 percent by mass of particles smaller than 3 microns in diameter.
This objective, for a dust with a typical fine particle distribution, is shown
graphically below. Except for two TCA scrubbers, the performance of all
conventional and novel scrubbers tested by IERL-RTP is represented by points
along or above line A in the graph. The TCA scrubbers are represented by the
circle labeled TCA.
The major thrust of IERL-RTP's scrubber program has been aimed at develop-
ing and demonstrating flux force/condensation (FF/C) scrubbers. In an FF/C
scrubber, water vapor is condensed in the scrubber. When the water vapor
condenses, additional forces and particle growth contribute to the particle
collection process. When the water vapor or steam is "free," FF/C scrubbers
are low energy users. However, when water vapor or steam has to be purchased,
FF/C scrubbers require additional energy inputs for efficient particle collec-
tion. A rough idea of the energy consumption/performance relationship for
FF/C scrubbers is shown in the graph. Note that when steam is free, FF/C
scrubbers approach the program objective. How much steam is needed and how
much is free are major unknowns at present. Since answers to both questions
are likely to be source specific, pilot demonstrations on a variety of sources
are necessary to provide required data. One pilot demonstration is complete
and a second is underway.
With one possible exception, all the non-FF/C scrubber work confirms
these data. The possible exception to the figure is the TCA or mobile bed
scrubber. The figure below shows data from field tests of TCA scrubbers.
Note that the TCA point is below the venturi and other scrubber lines by a
significant amount. At present, there is no explanation for the observed
performance of mobile bed scrubbers. In fact, one scrubber vendor claims that
mobile bed scrubbers (single-stage or multi-stage) are less efficient than
venturi scrubbers. On-going programs will provide the explanation for the .
81
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00
ro
0.1
0.12
OPERATING COST,$103/Vr/1000acfm
0.24 0.48 1.44 2.4
ASSUME: POWER COST 2.54/KWHR 8000 MRS OPERATION
PER YEAR
3 4 5 6 78 9
20 30| 50 70 90
PRESSURE DROP,mHjfy
Scrubber operating cost vs. aerodynamic cut diameter.
200 300
-------
observed performance and design equations and theoretical models for mobile
bed scrubbers. The research program also includes an investigation of the
effects of slurry scrubbing on mobile bed scrubber performance.
The overall efficiency of a scrubber system is determined by the effi-
ciency of both the scrubber and the entrainment separator. Recent field data
indicate that in some cases inefficient entrainment separator operation is a
major cause of poor fine particle collection by scrubbers. IERL-RTP has
completed a systems study of entrainment separators. On-going development
work will be used to develop and demonstrate high-efficiency and trouble-free
entrainment separators in conjunction with SOV scrubbing research and development.
J\
Fabric Filters
The performance of baghouses has been completely characterized on several
sources, including two utility boilers, an industrial boiler, and an electric
anffurnace. The data obtained from these tests show that baghouses are
excellent fine particle collectors and that their performance is not very
sensitive to particle size in the processes tested. A major advantage of
fabric filters is that they do not require increases in size or energy usage
for efficient collection of fine particles.
The current purpose in maintaining a research and development program in
fabric filtration is to promote increased capabilities and extend the range of
applicability in control of fine particulates. Of the three conventional
devices which can collect fine particles, fabric filters have been in indus-
trial service longest, but the least information is known about their opera-
tion from a theoretical standpoint. Although the filter is a simple device in
operation, there are complex problems in describing it mathematically. The
types of analyses used for scrubbers and electrostatic precipitators (ESPs)
have not been effective when applied to filters. Perhaps because the filter
already has a reputation for efficiency, EPA spending on filtration research
over the last few years has been at a lower level than for ESPs and scrubbers.
However, a major effort is now underway to produce design equations and mathe-
matical models for filtration processes. Publication of a comprehensive model
is expected in 1977.
Filtration work performed under IERL-RTP's Particulate Technology Branch
(PATB) has been aimed at acquiring information for a two-fold use: incorpora-
tion into mathematical models, and; addition to the empirical knowledge used by
designers and operators for everyday operation. This work has included studies
of fiber property effects and fabric-type effects; evaluation of new fabrics;
83
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development of mathematical descriptions for specific parts of the filtration
process; characterization of fabric filters in the field; investigation of
electrostatic effects; support of a pilot, and now, a demonstration program to
apply fabric filtration to industrial boilers at a several-fold increase ovep
normal filtration velocity; studies of cleaning and energy consumption in bag
filters; and a pilot program for control of municipal incinerators.
Industry can handle most of the filtration problems for sources which are
already controlled by fabric filters. Help is needed for sources which pre^
sent new problems and which are of priority interest to EPA. To design for
new sources, a better understanding of the filtration process must be acquired.
The objectives of immediate work in filtration then become:
0 Understanding the filtration process.
0 Applying it to priority sources.
0 Achieving cost/energy effectiveness.
0 Developing and testing new filter materials which can extend the
applicability of baghouses to a broad spectrum of sources.
In addition to a comprehensive contract research and development program
in fabric filtration, IERL-RTP also maintains a hands-on ihhouse program. Its
objectives are to identify superior fabric filter materials and operating
conditions by conducting screening studies on inhouse equipment, and to derive
basic information about the filtration process. It has provided information
on the performance of many types of filter fabrics. Much experience has been
gained with cotton and Dacron filter materials and this baseline data can be
used to evaluate the properties of novel filter fabrics (such as spunbondeds
and expanded PTFE laminates) when tested on inhouse equipment.
Laboratory work to complement and support grants, contracts, and other
inhouse tasks will continue. Tests such as studies of fabric type, cleaning
variables, effects of humidity, electrostatics, and process variations will be
conducted as needed. In addition, with two different baghouse systems in
operation, mechanical-shake cleaning can be compared with pulse-jet cleaning
to determine which cleaning mode can be optimized for the lowest particle
penetration. To complement the baseline data for overall efficiency for
various bags, instruments are being utilized to determine the collection
efficiency for various size ranges.
A new versatile fabric (baghouse) test chamber was ordered in FY 75.
This device will be capable of testing bags at both high (1500°F) and normal
84
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temperatures in environments which will simulate real process conditions. The
chamber is scheduled for operation early in 1977.
ASSESSMENT OF THE COLLECTABILITY OF DUSTS
A fleet of mobile conventional collectors which can be easily transported
from source to source and tested has been constructed and will be used in
support of this program.
The fleet includes a mobile fabric filter, a mobile scrubber, and a
mobile ESP unit. These mobile units are highly versatile and will be used to
investigate the applicability of these control methods to the control of fine
particulate emitted from a wide range of industrial sources. The relative
capabilities and limitations of these control devices will be evaluated and
documented. This information, supplemented by data from other IERL-RTP partic-
ulate programs, will permit selection by equipment users of collection systems
that are technically and economically optimum for specific applications.
NEW PARTICULATE CONTROL TECHNOLOGY DEVELOPMENT
This program area has become known as "New Concepts." As the requirement
to collect finer and finer particulate has developed, the cost of conventional
control (ESPs, fabric filters, scrubbers) has risen. Since many important
collection mechanisms become far less effective on particles <1 micron in
diameter, conventional devices (except for fabric filters) have become larger
.or require more energy and thus are more expensive. The objective of new
concepts research and development is to develop new mechanisms or new combina-
tions of well-studied mechanisms in order to achieve cost-effective control of
fine particulate not easily controlled by conventional devices. New concepts
include any new technology which has not been reduced to practice and may or
may not have been previously studied.
Mechanisms utilized by scrubbers and fabric filters are impaction, inter-
ception, and diffusion; and by ESPs, are field and diffusion charging. This
combination of mechanisms gives rise to a minimum in efficiency at the 0.2 to
0.5 micron range for conventional devices. Under optimum conditions, this
minimum may be greater than 90 percent for scrubbers and ESPs and greater than
99 percent for fabric filters. However, under conditions such as high tempera-
ture, high ash resistivity, sticky particulate, and corrosive or explosive
flue gases, new concepts specific,to a problem will have an advantage.
Most work to date has been directed toward combining electrostatic re-
moval mechanisms with scrubbing or filtration mechanisms. The first area to- .
85
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be developed was charged droplet scrubbing with a feasibility study at the
Massachusetts Institute of Technology and a pilot demonstration at TRW, Inc.
on a Kaiser coke oven. Electrostatics and filtration are being studied at
both Battelle-Northwest (BMW) and Carnegie-Mellon University Research Center:
the former with bed filters; the latter with baghouses. At least two new
concepts—a ceramic membrane filter and a magnetic metallic fiber bed—may be
applied to cleanup of high-temperature gases (1000 to 2000°F). Other new
concepts being studied include foam scrubbing and pleated cartridge filters of
a novel material.
Most new concept work is in an intermediate stage of development so thai;
demonstration data is limited. The TRW charged droplet scrubber has been
demonstrated and was capable of better than 94 percent removal of 0.6 micron
particulate. IERL-RTP has evaluated nearly 40 new concepts to date; of these,
nine have been selected for funding support.
NEW IDEA EVALUATION AND IDENTIFICATION
This program area has become known as "Novel Devices." It includes, in
addition to novel device evaluation and testing, a program aimed at solicit-
ing, stimulating, and identifying new ideas for fine particulate control.
As a part of this latter objective, IERL-RTP1s Particulate Technology
Branch has planned and sponsored six symposiums and one seminar aimed at fine
particle control. PATB also has funded (FY 75) a literature search aimed at
identifying new technology in foreign countries (Japan, Australia, Russia, and
Canada).
Devices or systems based on new collection principles or on radical
redesign of conventional collectors are sometimes offered by private developers,
Under this program area, all such novel devices will be reviewed and, if
promising for fine particle collection, will be evaluated for performance and
related cost. It is intended that those showing promise of high-efficiency
fine particle collection at reasonable cost, if necessary, be further developed
or demonstrated.
More than 40 novel particulate devices have been identified. About ha]f
of these are of sufficient interest to justify evaluation by. IERL-RTP. So .
far, the following devices have been tested:
p Braxton—Sonic Agglomerator
0 Lone Star Steel—Steam Hydro Scrubber
0 R. P. Industries—Dynactor Sqrubber
86
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0 Aronetics--Two-Phase Wet Scrubber
0 Purity Corporation--Pentapure Impinger
0 Entoleter—Centrifield Scrubber
0 Johns-Manville—CHEAP Filter
0 Rexnord—Granular Bed Filter
0 Air Pollution Systems—Electrostatic Scrubber
0 Air Pollution Systems—Electrotube Scrubber
0 Century Industrial Products—-RFP 100 Wet Scrubber
Of the devices tested, the Lone Star Steel scrubber gave the highest
efficiency on fine particulate, but it is also a high energy user. It can use
waste energy, when available. The Aronetics scrubber is similar to the Lone
Star unit, but (in one test) did not appear to be as efficient. In a field
test, the CHEAF filter had an overall mass efficiency of 95 percent but main-
tained the efficiency down to about 0.3 microns. Laboratory tests have con-
firmed that this phenomenon is real. The APS electrostatic scrubber was equal
in fractional collection efficiency to a venturi scrubber using 1-1/2 to 2-1/2
times as much power. The APS electrotube, which is similar to a wet wall ESP,
gave some very high efficiencies on fine particulates--as high as 98.9 percent
on 0.5 micron particles. This performance is similar to that which can be
achieved in small wet ESPs with the same ratio of plate area to volumetric
flow rate. The Century Industrial Products scrubber performed slightly better
than a venturi scrubber with the same pressure drop on the effluent from a
lightweight aggregate drying kiln. None of the other devices tested had
acceptable fine particulate collection efficiencies.
The following devices are now being considered for testing:
0 United McGill—NAFCO ESP
0 Combustion Power—Dry Scrubber
0 Dart Industries—Hydro-Precipitrol Wet ESP
0 Ceil cote Company—Ionizing Wet Scrubber
0 Du Pont—Du Pont Scrubber
A University of Washington charged droplet scrubber has been fabricated
as a portable unit and is being installed on a steel plant electric arc fur-
nace for evaluation. If this unit shows promise, it will be evaluated on
other sources.
Parallel to the field testing effort, a small inhouse facility for testing
novel devices is being operated. A small foam scrubber has been constructed
and operated to complement contract work on this new concept.
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HIGH-TEMPERATURE/HIGH-PRESSURE PARTICULATE CONTROL
This program area was added in FY 75 as a result of the critical partic-
ulate and fine participate collection problems associated with advanced energy
processes. The broad objective of the high-temperature/high-pressure program
is to develop the particulate collection devices which are needed to ensure
the environmental acceptability of advanced energy processes. However, because
the requirements of such energy processes are as yet unknown, IERL-RTP has
established a near-term (18 to 24 month) objective of developing the fundamental
information on the mechanics of aerosols at high temperatures and pressures
necessary to determine the path of high-temperature/h'igh-pressure particulate
collection research and development.
The state-of-the-art of high-temperature/high-pressure particulate collec-
tion is very unclear. There is no clear specification of the degree of partic-
ulate collection needed by advanced energy processes. Also, there are no
reliable data for the performance of the particulate collection devices pro-
posed by various companies; e.g., granular bed filters and high-pressure-drop
cyclones. There are few data, correlations, or verified theories that can be
used to predict the performance of particulate collection devices at elevated
temperatures and pressures.
Most, if not all, developers of advanced energy processes are assuming
that either cyclones or granular bed filters will provide the degree of partic-
ulate collection required by their processes. However, there is no real
justification for such an assumption.
IERL-RTP, through FY 75 funded contracts, is conducting research to:
determine the feasibility of high-temperature/high-pressure ESPs; determine
the effects of high-temperature/Kigh-pressure on basic particle collection
mechanisms (literature search funded in FY 75, experimental study funded in FY
76); and determine the estimated particulate cleanup requirements of proposed
energy processes. These tasks are not connected with specific energy processes.
IERL-RTP, as part of the advanced energy processes program, is looking at
granular bed filters (Exxon miniplant) and high-pressure-drop cyclones (Con-
solidation Coal) for use in particular energy processes.'
IERL-RTP, as part of the Novel Particulate Device Program, is attempting
to evaluate either or both the Rexnord and CPC granular bed filters. IERL-RTP,
as part of the high-temperature/high-pressure control program, is supporting
work on hot filtration and on dry scrubbing of fine particulate.
-------
ENERGY ASSESSMENT AND CONTROL
lERL-RTP's work in the area of energy assessment and control can be sub-
divided into three distinct functional groupings: combustion research, fuel
processes, and advanced processes. The following subsections of this report
discuss these groupings separately.
COMBUSTION RESEARCH
The Combustion Research Branch is directed toward the characterization,
assessment, and control of the environmental impact of energy conversion tech-
nologies. Programs are underway to identify the multimedia pollution problems
associated with combustion processes (i.e., related to residential, commercial,
industrial, and utility boilers, industrial furnaces, and stationary gas tur-
bine and reciprocating internal combustion (1C) engines) utilizing conventional .
fossil and alternate new fuels.
The major goals of these efforts are the development and demonstration of
combustion modifications and control techniques or devices to prevent or mini-
mize pollution problems for these processes in a cost-effective, energy-conserv-
ing, process-efficient, and environmentally acceptable manner. Although the
major emphasis of the program is on investigation of technology for control of
oxides of nitrogen (NO ), efforts are also underway to reduce or eliminate
/\
other pollutants (such as hydrocarbons, carbon particulate, smoke, carbon
monoxide, and various potentially hazardous species) while simultaneously maxi-
mizing system efficiency by optimizing system design and operating characteris-
tics.
Combustion sources contribute about 98 percent of the total NQV emissions
/\
from stationary sources. Some NO is formed in all fossil fuel combustion
' f\ . '
processes. Recent estimates of NO emissions from major source categories in
J\
1974 are shown in the following figure. Control technology development studies
to date indicate that combustion modification is the primary nearrterm method
of controlling NO emissions from the combustion of fossil fuels.
/\
Until recently, it appeared that existing or a low level of development of
stationary source control technology would be adequate to achieve and maintain
air quality in the 1980 to 2000 period. However, since 1973, the energy short-
age and changes in the national NO abatement strategy have placed additional
/\
demands on the stationary source control technology.
89
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UTILITY
BOILERS
47.8%
INDUSTRIAL
BOILERS
17.7%
INCINERATION 0.4%
OTHERS 14*
GAS TURBINES 1.^%
NONCOMBUSTION 1.7%
INDUSTRIAL PROCESS 2.9%
HEATING
SOURCE
UTILITY BOILERS
INDUSTRIAL BOILERS
RECIPROCATING 1C ENGINES
COMMERCIAL/RESIDENTIAL HEATING
INDUSTRIAL PROCESS HEATING
NONCOMBUSTION
GAS TURBINES
INCINERATION
OTHER
TOTAL
ESTIMATED NOX EMISSIONS
TONS/year
5,814,000
2,153,000
2,140,000
1,069,000
350,000
224.000
190,000
43,400
192,000
12,175,400
Summary of 1974 stationary source NOX emissions.
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Current combustion research activities to address the above needs are
divided into the following elements: field testing and environmental assess-
ment, process research and development, fuels research and development, and
fundamental studies. Field testing is directed toward the determination of the
range of NO control possible in existing equipment, and environmental assess-
/\
ments identify the multimedia environmental impact of stationary combustion
sources and NO control systems for attainment and maintenance of current and
A
projected air quality standards. Process research and development encompasses
the development and demonstration of optimum NO control technology for exist-
/\
ing and new combustion systems. Fuels research and development studies are
designed to develop generalized combustion control technology which is applic-
able to the control of NO and other pollutant emissions from the combustion of
/\
conventional fuels, waste fuels, and future fuels. Fundamental studies provide
an understanding of the important phenomena in the formation and destruction
of pollutants during combustion which may then be utilized in pilot-scale
equipment and fuels control technology.
A further element of the program is the efficient dissemination of tech-
nical information from its research activities to control developers, equip-
ment manufacturers and users, and the authorities involved in setting and
enforcing standards. Two practices have been initiated to establish an ef-
ficient means of technology transfer: (1) symposiums and (2) bulletins.
The first symposium on Stationary Source Combustion took place in Atlanta
in September 1975, and the next meeting is scheduled for New Orleans for-
August 29 through September 1, 1977. Sessions were held in the key program
areas of the Combustion Research Branch. The Fundamental Research session
highlighted results from ten analytical and experimental studies of pollutant
formation and reduction and concluded with a panel discussion on "Combustion
Chemistry and Modeling." Developments in external combustion control, burner
modifications, combustion of alternate fuels and alternate combustion concepts
were presented in the Fuels Research and Development session. The Process
Research and Development session highlighted development of advanced NO con-
/\
trol technology through minor hardware changes to existing equipment which
will provide guidelines for low NO' new unit design and for retrofit field
/\
implementation of NO controls. The final session, Field Testing and Survey,
/\
contained seven papers on uncontrolled emission characterization and on control
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achieved by alteration of operating conditions. The proceedings of the
Atlanta meeting have recently been published as an EPA report.
The first issue of a bulletin, entitled "NOx. Control Review," was pub-
lished in March 1976. Issued approximately quarterly, the Review presents the
status of stationary source NOV control technology and related topics. Each
A
issue leads off with major recent developments or topics of general interest;
the remainder is divided into the following topical categories: control re-
search and development, control implementation, alternate processes, flue gas
treatment, regulatory strategies, technical briefs, recent publications, and a
calendar of upcoming meetings. Future issues will include a listing of appli-
cations of NOV control technology to major utility and industrial stationary
A
combustion sources.
Field Testing and Environmental Assessment
The field testing element includes studies designed to determine the po-
tential for control of NOV emissions from existing equipment. This work is
A
generally performed by research and development organizations familiar with
the specific combustion systems being studied, and with the financial and tech-
nical assistance of manufacturers, users, and trade associations. The field
testing and survey studies are the initial efforts in the development of con-
trol technology and are designed to demonstrate the state of the art in control
of NO and combustible emissions. In addition to developing trends and pro-
A
viding application guidelines for industry to minimize emissions with present
technology, the work also suggests where research and development efforts
should be concentrated by developing emission factors as a function of equip-
ment type and size, and fuel consumed.
The environmental assessment component of the program element focuses on
identification of the multimedia environmental impact of stationary combustion
sources and NO controls and, for this impact, identifies the most cost-effec-
A
tive, environmentally sound NO control systems for attainment and maintenance
A
of current and projected N02 air quality standards. This activity provides
program guidelines for development of NOV controls sufficient to assure com-
A
pliance (to the year 2000) with air quality standards in critical air quality
control regions.
UTILITY BOILER/POWER GENERATION EQUIPMENT FIELD TESTING
lERL-RTP's NOV control program was initiated in 1970 when Exxon Research
A
and Engineering Company began field testing utility boilers to define baseline
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emissions and establish the effect of combustion modification techniques. It
was found that NO emissions from gas- and oil-fired boilers could be reduced
A
by 50 to 60 percent by using combustion modification techniques such as low
excess air firing, staged combustion, flue gas recirculation, load reduction,
air preheat reduction, change in burner tilt, and change in primary to second-
ary air ratio. Of these, the first two were found to be most applicable and
cost-effective. Combustion modification with coal-fired boilers was less suc-
cessful for NO reduction and more difficult because of operating problems.
A
Since the Exxon systems study identified coal-fired utility boilers as the top
ranking source of NOV emissions from stationary sources, efforts were concen-
A
trated on these units. Further Exxon studies showed that reducing the excess
air level and employing staged combustion, as with gas- and oil-fired boilers,
resulted in significant NOV reductions, averaging about 40 to 50 percent for
A
the boilers tested. The degree of reduction, as well as baseline NOV emission
A
levels, varied with the design and size of coal-fired boilers tested and with
coal type. No extreme differences in flue gas particulate loadings and in the
carbon content of the fly ash were found during the boiler tests.
A subsequent extension to the Exxon field test program of utility power
generation equipment includes trace specie emission measurements and testing
of an additional six units including a carefully controlled investigation into
the effects of NO controls on tube wastage in coal-fired boilers. Emission
A
measurements will be made of sulfates, nitrates, HCN, HC1, ROMs, and PCBs in
addition to the original NO, N02, S02, S03, CO, C02, 02, HC, particle loading,
and particle size distribution. The additional test sites extend previous
emission characterizations and control tests to a broader range of design
types and operating conditions. Corrosion tests will be conducted on a 500 MW
horizontally-opposed, dry-bottom coal-fired boiler with an initial 4 month
baseline test to establish normal tube wastage rates followed by a 6 month run
in which low NOV conditions will be accomplished through low excess air firing
A
and staged combustion via burners out of service. The tests will use a new
ultrasonic tube thickness sensor (accurate to ± 0.0001 inch), corrosion
coupon probes, and replaceable tube wall panels with before and after
metal!ographic characterization.
A new program is being initiated to conduct long-term comprehensive emis-
sions and corrosion tests on coal-fired utility boilers designed to meet the
New Source Performance Standards for NOX of 301 ng N02/J (0.7 Ib N02/106 Btu)
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heat input. Each test boiler will exceed 125 MW in capacity and burn high-
sulfur bituminous coal. It is expected that these tests will fully quantify
the effects of NO combustion modification on emissions, corrosion, boiler
J\
performance, and reliability for major coal-fired boiler design types.
Future work with utility boilers will continue to concentrate on coal-
fired units, but will also consider firing of mixed fossil fuels (e.g., coal
and oil, and gas and oil) simultaneously, coal-derived fuels (e.g., low-
Btu gas and solvent refined coal), and waste fuels. Tests are also underway
with other power generation equipment such as gas turbines and large internal
combustion engines.
FIELD TESTING OF INDUSTRIAL BOILERS
Iri 1973, a major field test program with industrial boilers was initiated.
KVB Engineering was awarded a contract to test approximately 50 gas-, oil-,
and coal-fired boilers, ranging in size from 10,000 to 500,000 pounds of steam
per hour during the first year. Measurements included efficiency and emis-
sions of NO , SO , HC, CO, smoke, and particulate mass. The tests were short-
X A
term and concentrated on operating variables such as excess air, load, swirl
adjustment, and primary, secondary, and tertiary air adjustment. During the
second year, 18 boilers were tested in more detail with more extensive modi-
fications, such as overfire air, flue gas recirculation, and variable air
preheat temperature. Also, particle size distribution and (on approximately
five oil- and coal-fired boilers) trace specie emissions were measured. The 2
year study provided the following data on uncontrolled baseline emissions:
164-922 ppm, 65-619 ppm and 50-375 ppm for coal, oil and gas firing, respec-
tively. Corresponding baseline operation emission averages were 275 ppm, 120
ppm, 293 ppm, 269 ppm and 139 ppm for coal, #2 oil, #5 oil, #6 oil, and natural
gas. Excess air, burners out-of-service and flue gas recirculation proved to
be the most effective combustion modification techniques for reduction of NO
A
emissions without sacrificing boiler efficiency. NO reductions up to 35
A
percent without increases in particulate emissions were experienced with low
excess air firing. Flue gas recirculation reduced NOV by 10 to 40 percent,
A
but increased particulate by 5 percent and boiler efficiency was slightly re-
duced. The burners out-of-service technique reduced NO up to 54 percent
A
without reduction in efficiency, but particulate emissions always increased.,
A final report was recently completed on the second phase of this project, and
the study will culminate in the issuance of instructional guidelines for low-
emission operation and design of industrial boilers.
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FIELD TESTING OF INDUSTRIAL PROCESS EQUIPMENT
IERL-RTP has contracted with KVB to conduct a 1 year field test program
for industrial process equipment, gas turbines, and internal combustion en-
gines. Emphasis is on detailed emission characterization -of a representative
group of furnaces, kilns, ovens, and dryers, firing coal, oil, gas, waste
fuel, and mixed fuels. Measurements will be made of NO, N0£, SO^, $03, 0»>, CO,
COp, HC, particle size and grain loading, opacity, and where relevant, trace
metallics and trace organics (POM, PCB). KVB will also assess the degree of
emission control achievable from modification of operating parameters such as
unit load, excess air, and combustion air preheat. The gas turbine tests will
assess the use of water injection as a means of NO control. A total of 25
/\
units will be tested.
RESIDENTIAL/COMMERCIAL HEATING SYSTEMS TESTING
In an lERL-RTP-sponsored effort, Battelle has recently completed work on
guidelines for residential and commercial oil burner adjustments. Intended
for use by service managers for service training and by skilled service tech-
nicians in their oil burner service work, the adjustment guidelines are impor-
tant because they ensure reliable automatic operation, provide for efficient
fuel utilization and minimize air pollution. In addition, the guidelines also
include appendixes with background material on pollutants of primary concern,
field-type instruments and significance of measurements, fuel oil characteris-
tics, and emission characteristics of residential and commercial oil burners
and boilers.
A pamphlet produced inhouse entitled "Get the Most From Your Heating Oil
Dollar - Servicing Cuts Cost and Pollution" is being distributed to homeowners
throughout the U.S. It is designed to transfer emissions and fuel conserva-
tion technology developed during field tests of residential equipment directly
to the public.
Inhouse studies closely related to the field testing are being conducted
on emission characterization and design evaluation for commercial combustion
systems. The objective of this work is to investigate, under controlled lab-
oratory conditions, the emission performance of existing/prototype commercial
combustion systems and components and to evaluate effects of new burner/combus-
tor designs and modifications on emissions and energy efficiency performance.
Two different equipment systems have been baselined; that is, the best condi-
tions for minimum emissions with unaltered equipment have been established.
. 95
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These systems include two major types of firetube packaged boilers: Scotch
marine and firebox.
The Scotch marine firetube boiler has been utilized for the study of two
fuel-oil/water emulsion devices: The Cottell Ultrasonic Emulsifier and the
Total Emulsifier. The Cottell device provided significant reductions in smoke
number and particulate emissions. The Total device provided significant
reductions in particulate when firing distillate-oil/water emulsions, but
smoke increased because the particle size distribution shifted to a smaller
size. Neither emulsifier reduced NOY emissions significantly when firing
/\ ,'.'
residual oil (which has a high-fuel nitrogen content); however, a significant
NO reduction was observed when distillate oil was fired. On-going tests on
A
the Elf Union (a French oil company) emulsion burner with a capability of 10
to 70 gph capacity have not resulted in data as yet. Some emulsion devices
may have a small potential for energy conservation by permitting boiler opera-.
tion at lower excess air levels, but this may require trading back the emission
improvements.
In addition to the basic emission characteristics, a number of design and
equipment changes have been studied. A burner redesign program was successful
in reducing CO, HC, and smoke emissions from the firebox/firetube package
boiler without increasing NO emissions. A fuel injection equipment program
X
has been carried out to determine emission characteristics from air, high-
pressure, and sonic atomization of #6 residual oil.
A comprehensive sampling and analytical system for use on IERL-RTP inhouse
equipment facilities is being developed by Aerotherm and A. D. Little. The
system, consisting of a specialised source assessment stack sampler and a com-
plete analytical chemistry lab, is presently in the design phase. Design com-
pletion is expected in late 1976 or early 1977.
ENVIRONMENTAL ASSESSMENT AND SYSTEMS ANALYSIS OF NOY COMBUSTION
MODIFICATION TECHNOLOGY *
A major contract award has been made to the Aerotherm Division of Acurex
Corporation for a multimedia environmental assessment and system analysis of
NO combustion modification techniques. This effort is to determine the tech-
*» ' .
nical soundness and environmental acceptability of these control methods, and
to ensure that any deficiencies or;potential problems are identified and cor-
rected in a timely fashion, before the technologies are adopted commercially.
The general technical approach in this project is based on the need to
provide efficient and timely assessments of near-term control technologies
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IO
Scotch marine boiler (60 hp) for emission control equipment evaluation.
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while maintaining a comprehensive treatment of likely control needs to the
year 2000. Throughout the program, emphasis will be given to synthesis of
existing and emerging technology on control systems, trace emission and pollutant
transport transformation and impact. The major project effort will go toward
the compilation and evaluation of data from past and on-going programs for the
EPA and other agencies. Additionally, the environmental assessment activities
will be coordinated with the IERL-RTP guidelines developed for the numerous
on-going source and environmental assessments. The evaluation of potential
air quality standards and N02 abatement strategies will be coordinated with
the Office of Air Quality Planning and Standards (OAQPS) as well as the several
task forces established to define mobile source emission control needs. The
intent of this evaluation is to obtain an objective overview of the future
needs for combustion modification NO controls.
/\
The approach and level of effort allocated to project tasks is based on
prioritization of sources, controls, pollutants, and Air Quality Control Re-
gions (AQCRs). The basis of the prioritization is to focus the study on de-
velopment needs for environmentally sound control systems. Throughout the :
program, emphasis will be given to those sources, controls and multimedia
impacts most likely to be involved in control implementation in critical
AQCRs up to the year 2000. Early use of the systems analysis models will aid
in setting the program priorities. A screening approach will be used in the
systems analysis whereby a simple model will be used to prioritize the options.
More sophisticated models will be introduced for verification as process and
emission data become available.
The effort will be time-phased on a descending priority basis with early
emphasis on near-term sources and controls. Subsequent updates will be made
to maintain a current assessment of the high-priority areas. This approach
requires parallel initiation of all program elements with early emphasis on
gathering results from previous efforts and later emphasis on synthesis or
generation of new data.
Process Research and Development
lERL-RTP's process research and development work involves the application
of optimum NO control technology to existing and new combustion systems. The
/\
results of these studies provide the basis for the demonstration of combustion
control technology. During the past year, interest in projects in this area
has continued to develop.
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COMBUSTION MODIFICATION FOR UTILITY BOILERS
In a study being conducted by Combustion Engineering, Inc., a 400 MW
tangential utility boiler equipped with factory-installed overfire air firing
western bituminous "B" coal yielded NOV emissions as low as 189 ng NO~/J
6
(0.44 Ib N09/10 Btu), which is below the Standard of Performance for New
L- C
Stationary Sources of 301 ng N02/J (0.7 Ib N02/10 Btu). Baseline NOX emissions
for this unit, without the use of the overfire air system, ranged from 258 to
301 ng N02/J (0.6 to 0.7 Ib N02/10 Btu) at normal excess air levels. Further
tests evaluated the effect of total excess air, overfire air rates and tilts,
burner tilt, wall slag and unit load. A 25 percent NOV reduction from baseline
X
was observed at normal, total excess air levels (26.2 percent) with the primary
flame zone operated at 105 percent of stoichiometric. Slag buildup produced a
negligible increase in NO under staged conditions. As with baseline condi-
/\
tions, NOV increased with unit load. Carbon heat losses of 0.2 to 0.6 percent
J\
resulted during staging. This level corresponds to the losses experienced
under normal firing when operating below 15 percent excess air. Similar tests
are now being conducted on a unit firing western subbituminous "C" coal, A
final report on these two tests should be complete by early 1977.
Under an interagency agreement with IERL-RTP, TVA has evaluated biased
firing on a 125 MW wall-coal-fired utility boiler. The tests indicate that a
30 to 50 percent NOV reduction could be obtained for wall-coal-fired units de-
A
pending upon load and burner configuration. Biased firing increases the
carbon losses in the particulate causing a reduction in the ash conductivity
which could affect ESP performance. The increases, however, were not deemed
significant. Boiler efficiency is reduced over the entire load range under
biased firing conditions. Data from 1 month tests using specially designed
corrosion probes indicate accelerated tube wastage rates on the side walls,
but the statistical significance of these results is currently in question.
Aerospace Corporation, under IERL-RTP sponsorship, has compiled and cor-
related field test data collected by the Los Angeles Department of Water and
Power for some of their gas- and oil-fired utility boilers. A report on the
extension of this effort to include coal-fired utility boilers is now in prep-
aration. In addition to correlating emission data with combustion modification
techniques, Aerospace has performed a combustion stability analysis to determine
how a boiler can be redesigned to allow more flexibility in the use of combus-
tion modifications. Aerospace is also generating a stationary source emissions
99
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inventory to the year 1975 and emissions projections to the year 1985. A
final report has recently been completed.
Monsanto Research Corporation is currently preparing a report based on a
study of utility and industrial coal-fired cyclone boilers. The objective of
the study was to assess the need and the potential for controlling NO emis-
/\
sions from existing coal-fired cyclones. The final report will provide a
population and geographic distribution with NOV emission rates from several
A
sources, as well as definition of available combustion modification techniques.
Results will include projections of potential NO reduction through combustion
/\
process modifications and estimates of research and development costs to de-
velop corresponding retrofit controls.
COMBUSTION MODIFICATION FOR INDUSTRIAL BOILERS
KVB Engineering, Inc., under contract to IERL-RTP, tested ten intermediate
sized (10,000 to 300,000 pph), pulverized-coal- and stoker-fired boilers to
determine the feasibility of substituting low-sulfur western subbituminous
coal for high-sulfur eastern bituminous coal primarily as a means of reducing
sulfur oxide emissions. The resulting impact on NO was also assessed. Major
X
emphasis was placed on stoker units as pulverized coal units in this capacity
range are less prevalent. Lower NO emissions were measured on both pulverized
A
coal units and stokers as a result of the lower fuel nitrogen content of the
coal and of the lower combustion temperatures due to the high moisture content
of western coals. In general, the conversion of intermediate boilers to
western coals was found to be a feasible alternative. Guidelines for conversion
of a variety of design types to the use of western coals are in preparation.
A contract program was initiated in late 1976 to study potential emission
control technology for stoker-coal-fired industrial boilers. The program will
focus on the complete spectrum of emissions from the sources and will develop
technology to improve the environmental acceptability of stoker boilers. This
contract will expand the prior work on small stokers to larger-scale spreader
stoker boilers and include a more comprehensive assessment of processed coals.
COMBUSTION MODIFICATION FOR RESIDENTIAL/COMMERCIAL HEATING SYSTEMS
Battelle, under contract to IERL-RTP, completed a technical assessment of
increased utilization of stoker coal systems for residential and small commer-
cial space heating applications. The assessment was based on (1) an experi-
mental study evaluating emissions (including carcinogenic POM) from a 20 tip
boiler firing a variety of coals and processed fuel, (2) a survey to identify
100
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equipment and manufacturers, and (3) a survey to identify processes for the
production of smokeless coals. The experimental research indicated that mod-
ifications in design and operation of small stoker boilers have potential for
emissions reduction and, coupled with utilization of processed coals, could
achieve improvements over existing equipment. However, the conclusion was
made that current economic and environmental factors are unfavorable for in-
creased utilization of coal in residential and small commercial applications.
STATIONARY ENGINE COMBUSTOR TECHNOLOGY
A program recently initiated with Pratt and Whitney Aircraft is directed
toward the development of low NO gas turbine combustor technology. The study
A
will focus primarily on dry control techniques because of fuel economy and
operational considerations and will specifically address utility size (25 MW
and larger) gas turbine units. Since future gas turbines may be required to
burn heavier fuel oils or low-Btu gas containing significant levels of ammonia,
the contract will also address control of NO resulting from the conversion of.
A
fuel nitrogen.
IERL-RTP has initiated an inhouse investigation of stationary engine
emissions control. Two engines have been installed at IERL-RTP: a gas turbine
and a precombustion chamber diesel. (See following illustrations.) Experimental
work to date has concentrated on the gas turbine with initial indications that
CO, HC, and fine particulate emissions are serious problems in the unit. De-
termination of the baseline emission characteristics resulted in the N02 frac-
tion of total NO ranging from 45 percent at no load to a negligible amount at
/\
rated load. The water/oil emulsion proved beneficial as a NOV reduction tech-
A
nique with a 33 percent reduction in NO and total NO with a 26 percent addi-
A
tion of water. The water fraction is limited by the characteristics of the
emulsion to about 35 percent. At water injection rates sufficient to appreci-
ably reduce NO levels, CO levels could increase by as much as 20 percent over
A
the lowest emission rates.
Tests on the precombustion chamber diesel engine have recently begun.
The NO levels appear to be reduced by use of an oil/water emulsion, but data
A
are still being analyzed. A catalytic muffler was"tested with the diesel
in late 1976.
The CRB is selecting a contractor for a new program in low NO 1C engine
A
development. The purpose of the new program is to investigate internal combus-
tion engine chamber design parameter effects on air pollutant emissions. The
101
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o
ro
.•
225 KW gas turbine used for IERL-RTP in-house studies.
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o
to
Precombustion chamber diesel (300 hp) for stationary engine controls development.
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goal is the development of a design giving substantial reductions in NO emis-
/\
sions for large bore stationary 1C engines while maintaining or improving cur-
rent technology levels for CO, HC, and carbon particulate emissions and fuel
efficiency. Both new design and retrofit to existing engines will be considered;
designs will be developed for gas-fueled spark ignition and oil-fueled compres-
sion ignition 2- and 4-stroke engines.
INDUSTRIAL PROCESS EQUIPMENT AND AFTERBURNERS
The Institute of Gas Technology, under contract to IERL-RTP, has recently
completed a survey of industrial process combustion. The objectives of the
study were threefold: to identify the significant emission sources, to investi-
gate the potential for effective emission controls, and to compile information
on combustion equipment in use and future trends in process and equipment de-
sign. The iron and steel, cement, glass, aluminum and petroleum refining in-
dustries were identified as the major sources of combustion generated air
pollution within the process combustion field. Recommendations were presented
for NO control research and development programs for each of the significant
/\ . .
processes within each industry.
A new program in 1976 will assess the pollution control and energy conser-
vation potential of afterburner combustion systems. The primary objective of
this study is to assess the environmental status of afterburner combustion
systems and to develop guidelines for their application to minimize environ-
mental problems. The program will completely analyze the problem of emissions
from afterburner combustion systems and result in a standards-of-practice
manual for applying these systems for emissions control without creating ad-
ditional environmental problems.
FLUIDIZED-BED COMBUSTION SUPPORT
A contract has been awarded to Aerotherm for the design and construction
of a fluidized-bed combustion (FBC) sampling and analytical test rig. This
small pilot-scale equipment will be installed and operated in IERL-RTP's
inhouse combustion research laboratory. This project is to provide for:
comprehensive analyses of emissions from FBC, testing of alternative sampling
and analytical procedures for FBC, and investigation of alternative add-on
environmental control devices for FBC. Conceptual design has been completed,
and installation and shakedown at IERL-RTP are scheduled for completion in
mid-1977.
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Fuels Research and Development
Fuels research and development studies are designed to develop generalized
combustion control technology which is applicable to the control of NO and
A
other pollutant emissions from the combustion of conventional fuels, waste
fuels, and alternate new fuels. These studies are conducted on versatile ex-
perimental combustion systems with the specific purpose of developing combus-
tion control technology for a specific fuel through single-burner design
criteria or other combustion modification techniques.
IMPROVED BURNER/SYSTEM DESIGN
The Institute of Gas Technology has submitted a report on the investiga-
tion of the relationship between combustion aerodynamics and air pollutant
emission characteristics of industrial gas burners firing natural gas. Three
types of burners were studied: a scaled-down utility boiler burner, a kiln
burner, and a baffle burner for steel reheat furnaces. The boiler burner
showed NO reductions up to 91 percent with flue gas recirculation (FGR). For
A
the boiler burner, use of a 30 degree ring nozzle consistently produced lower
levels of NO emissions than the 60 degree gun nozzle. For the kiln burner,
A
NO emission reductions as high as 68 percent were demonstrated. The pre-
A
ferred approach was to modify burner parameters to yield the flame shape and
length that will produce minimum NO emissions. For the baffle burner, ex-
A
ternal flue gas recirculation of 30 percent resulted in as high as 90 percent
reduction in NO emissions. Present emphasis in this study is on the assess-
A
ment of the emission characteristics of low-Btu gases fired at ambient and
elevated temperatures. Five gases are being investigated representative of
the following industrial processes: Wellman Galusha-Air, Winkler-Air, Lurgi-
Oxygen, Winkler-Oxygen, and Koppers Totzek-Oxygen. The overall objective of
this program is to develop technology to allow optimum low-emission combustion
systems to be designed and widely used by industry.
ADVANCED COMBUSTION MODIFICATION TECHNIQUES
Aerotherm Division of Acurex Corporation is conducting a 2 year IERL-RTP-
funded pilot-scale furnace test program to develop advanced combustion control
techniques for NOX reduction. The test furnace" (see following illustration),
with a capacity of 3,165,000 KJ/hr (3,000,000 Btu/hr) is being operated in the
wall-fired and tangential, corner-fired modes and is capable of firing coal,
oil, gas, mixed fuels, waste fuels, and synthetic fuels from coal. The furnace
105
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Multiburner experimental furnace (3 million Btu/hr)
106
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was designed to give a temperature/time profile of the combustion gases repre-
sentative of industrial and utility boilers providing for more direct
translation of low NO firing configurations to full-scale equipment. The
A
results of this program will guide demonstration tests on large-scale prototype
units and provide suggestions for advanced equipment design. Preliminary
baseline, uncontrolled tests showed very good correspondence with full-scale .
equipment with both the level of NOV emission and the trend with excess air
A
and preheat. Emphasis to date in the NO control development tests has been
A
on optimizing procedures for staging by use of overfire air ports with the
firing of pulverized coal in the wall-fired mode. Variables considered in the ,
optimization tests include first-stage stoichiometry and mixing, first- and
second-stage stoichiometry, overfire air preheat and injection pattern, total
excess air and burner air preheat. Tests with a high-nitrogen Kentucky bituminous
coal have shown NO reductions in excess of 75 percent when the primary flame
A
zone is operated with 90 percent or less of stoichiometric air. At a total
excess air level of 15 percent, NO emissions are in the range of 100 to 200
A
ppm (corrected to zero percent 02) with staged combustion compared to a level
of 850 ppm with normal, uncontrolled operation. These optimization tests are
being extended to the firing of other coal types and to operation in the
tangential firing mode.
Rocketdyne Division of Rockwell International under IERL-RTP contract has
recently completed a two-part study which resulted in the development of an
advanced design residential warm air oil furnace which offers a 65 percent
reduction in NO emissions and up to 10 percent increase in fuel efficiency.
A
The initial effort involved the development of an optimal oil burner head
through evaluation of the effects on NO formation of combustion air, swirl
A
angle, nozzle spray angle, axial injector placement, flue gas recirculation,
and combustion gas recirculation as a function of oil flowrate and overall
excess air. The optimized burner was a nonretention gunburner with an optim-
ized choke-diameter and swirl vanes. Hydrocarbon and CO emissions remained at
commercial burner baseline levels while NOY emissions were 1 g NO/kg fuel
A
compared to 2 to 3 g NO/kg fuel at baseline. The second part of the program
was directed toward development of an optimized burner/firebox combination.
The final design utilized the optimized burner firing into the side of a ver-
tical, cylindrical, fin-cooled firebox. At 10 percent excess air, NOV emis-
A
sions of 0.6 g NO/kg fuel were measured and increases in system efficiency of
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up to 10 percent have been experienced. The system has recently completed a
500 hour laboratory performance test and will be ready for field testing in the
near future. In addition to system development, the program has evaluated
techniques for mass production of the optimized head. A final report is an-
ticipated early in 1977. A new contract has recently been signed with Rocket-
dyne to extend the previous study to the investigation of feasible manufactur-
ing processes for the new oil furnace designs. This contract calls for the
manufacture of six units for use in field tests during the 1977 to 1978 heating
season.
A contract has recently been awarded to Honeywell for an experimental
study to investigate the characteristics of fuel oil atomization with a thermal
aerosol oil burner using #1 and #2 fuel oils with emphasis on combustion ef-
ficiency, soot formation and design requirements. The effect of oil tempera-
ture and pressure, droplet size, inlet air temperature, air/fuel ratio and
firing rate on flame luminosity, soot particle concentration and size distribu-
tion, NO emissions and flue gas temperature will be investigated. Additional
*»
measurements will be taken of CO, HC^ smoke, 02, Ct^. stack temperature and
burner efficiency.
Ultrasystems, Inc. is under contract to IERL-RTP to define low NO
/\
burner design criteria for scale-up from an experimental 5 million Btu/hr
optimized burner to practical size burners (125 million Btu/hr). The scaling
criteria will assess the burner interactions occurring on full-scale boilers.
The emphasis is on coal burners, although residual oil and combined coal/low-
Btu gas are also to be studied. The burner test facility (see following
illustration) was designed to allow evaluation of the performance of single
burners of capacity up to 125 mi'.lion Btu/hr and multiple burners totaling 60
million Btu/ hr in combustion chambers simulating commercial practice. The '
facility has been completed, and tests are scheduled for an early 1977 start
date.
Ultrasystems is also conducting a study to generate low-emission burner
concepts for residual oil combustion in packaged boilers. The study consists
of an experimental phase (for the development of burner design concepts applic-
able to package boiler geometry) and an application phase (for testing a
prototype burner in a field operating boiler). To date, a variety of burner
configurations have been studied and an optimum has been identifiedWhich gives
NO reductions in the range of 65 to 75 percent for three fuel oils with
/\
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o
10
Full-scale burner test facility (125 million Btu/hr).
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nitrogen content between 0.2 and 0.71 percent. The 0.2 percent nitrogen pro-
duced the lowest NO (120 ppm) while maintaining acceptable smoke levels. The
/\
results have also identified oil atomization conditions and fuel properties as .
important variables governing both NO and smoke levels. A contract is under
A ' •'
negotiation to investigate these parameters as related to combustion air flow
patterns.
CATALYTIC COMBUSTION
Aerotherm has recently been contracted by IERL-RTP to investigate the
concept of catalytic combustion in which premixed clean fuels are reacted
heterogeneously and at low temperature over catalytic monoliths. The overall
objective of the program is to provide scale-up criteria to allow application
to a wide range of stationary combustion equipment. The objective will be met
by screening small-scale catalysts, performing small-scale system concept
tests, and then scaling the results up to larger catalysts and systems.
Results of the small-scale catalyst screening experiments have identified the
graded-cell catalyst system as an acceptable concept for further testing. The
graded-cell system uses a ceramic monolith with large cells at the combusti.on
inlet, with subsequent monolith sections having progressively smaller cells.
The catalyst used is platinum on an alumina washcoat. Tests with this system
have shown good performance under lean conditions with both methane and propane
fuels.
ALTERNATE FUELS
Past inhouse work has led to significant understanding of the formation
and control of fuel NO produced from chemically bound nitrogen. The study has
examined burner design, staged c.-mbustion, flue gas redrculation, and other
techniques for control of both thermal and fuel NO from natural gas, propane,
distillate and residual oils, and coal. The current thrust of this program is
to define combustion and emission characteristics of alternate fuels, with
emphasis now being placed on high-nitrogen coal-derived fuels. The program
makes use of a versatile 300,000-Btu/hr experimental furnace with provision
for precise control of combustion parameters such as fuel type and injection
method, air rate and introduction method, air preheat, firebox residence time,
and firebox and convective section heat removal rate (see following illustration
In addition, combustion modification techniques can be studied in a variety of
applications. The initial class evaluated was alcohol fuels, which may be
produced from coal gasification. They appear to have low emissions of NO and
favorable combustion characteristics relative to conventional clean fossil
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Experimental system for combustion modification and future fuel studies.
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fuels. The next class of fuels to be studied will be low-Btu gas. A fuel gas
generator has been designed and built by the Jet Propulsion Laboratory under
an interagency agreement and will be delivered in 1977. The key process
variables will be CO/H2/N2 ratios, fuel gas temperature, and NH3 content.
Fundamental Combustion Research
lERL-RTP's fundamental research studies are providing an understanding of
the important phenomena in the formation and destruction of pollutants during
combustion. The basic knowledge is being translated to pilot-scale or field
equipment studies to identify how the pollutant formation mechanisms can be
controlled through combustion process modifications. The primary purpose of
this program element is the application of fundamental research to practical
NO control problems with emphasis on interpretation of test data, identifica-
A
tion of further test programs, understanding and resolving operational problems,
and suggestion of new research areas. A contractor will soon be selected to
perform and subcontract a highly coordinated fundamental studies effort to
consolidate the present programs. Program efforts will focus on application
to field- and pilot-scale test .results. Fundamental studies fall into two
categories: combustion chemistry and combustion aerodynamics. Combustion
chemistry is a complex process involving both fuel decomposition reactions and
reactions of other flame species resulting in formation and destruction of
pollutant species. The pollutant species of interest are NO , CO, HC, POM,
/\ . '
carbon particulate, fuel ash, and SO . The emphasis in this program is on NO,
/\
although the formation and destruction of other oxides and reduced nitrogen
species (e.g., HCN and NH3) are also included.
COMBUSTION CHEMISTRY
The area of combustion chemistry can be further subdivided into two
areas: pollutant formation related to combustion conditions, and pollutant
formation related to fuel composition. These areas are reflected in the
characterization of NOV formed by fixation of atmospheric nitrogen at high
A
temperature in the combustion process as thermal NOX, and that formed from
oxidation of nitrogen chemically bound in solid and liquid fossil fuels as
fuel NO. For most fuels the total NOV is the composite formed by both mechanisms,
A A
A new experimental program has recently been awarded to United Technology
Research Center for investigation of nitrate and sulfate formation and NO /SO
X A
interactions in flat flames in which various dopants will be used to promote
formation of these species. Tests will be conducted to determine the extent
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of in-situ probe interference on NO measurements in flames. A variety of
— """ " * 1J A
measurement techniques will be used in this determination including microprobes,
and optical and molecular beam mass spectroscopy. The data gained on inflame
species concentrations will then be used to determine respective formation
mechanisms through use of the PROF computer program described below.
A computer program has been developed at Aerotherm to analyze combustion
and pollutant chemistry in premixed flat flames. The Premixed One-Dimensional
Flame (PROF) code is a powerful tool being used to isolate governing kinetics
by comparison to experimental data from past and on-going flat flame measure-
ments. PROF has the capability of handling multicomponent diffusion, heat
loss and wall effects characteristic of real flames. The systematic comparison
of data and suggested kinetics is revealing the governing mechanisms of pollutant
formation and destruction including those of inorganics and fuel nitrogen.
Successful utilization of the PROF code will demonstrate the strong coordina-
tion between the experimental and analytical activities in fundamental studies.
Rockwell International's Rocketdyne Division is working, under an IERL-
RTP contract, to establish the mechanism and chemistry of fuel nitrogen conver-
sion to NO and other products. An experimental and analytical study has been
A
carried out to investigate the chemical mechanisms involved in the conversion
of fuel nitrogen to NO in combustion as a means of developing new approaches
/\
for minimizing fuel nitrogen conversion. The experimental work was composed
of two portions: (1) pyrolysis reactions that the volatile fuel nitrogen
compounds will undergo before approaching the flame front, and (2) combustion
reactions of fuel nitrogen compounds and their reaction products. Pyrolysis
experiments were conducted with model fuel nitrogen components, to measure the
kinetics parameters that determine under what conditions typical fuel nitrogen
structures will decompose and to identify the nitrogen-containing species that
are formed. Common fuel nitrogen structures were represented by the model
compounds pyridine, pyrole, quinilone, and benzonitrile. Fuel oils and coals
were subsequently pyrolyzed under similar conditions, and the nitrogen contain-
ing inorganic products were measured and compared with those formed by the
model compounds. Results indicate that HCN is a likely important intermediary
compound in the formation of fuel NO from fuel-bound nitrogen in combustion.
A
Burner studies of fuel NO reaction paths induced by the addition of HCN and
A
NH3 to premixed CH4-02~Ar flames were also conducted to determine the kinetics
of NO formation from these intermediaries. Results indicate that fuel NO
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forms relatively slowly above the luminous zone in the same region where CO
is oxidized to C02 or after. Results also indicate that NH3 may yield HCN as an
intermediary in the reaction to form NO. High NO yields were found with lean
flames and low NO yields, with rich flames. A one-dimensional mathematical
kinetic-diffusion model for the combustion of oil droplets and coal particles
was developed to simulate the thermochemistry controlling the formation of
fuel NO . The model is being used in a continuing effort to define the mecha-
}\
nisms and chemical paths leading to fuel NO . This contract has been extended
/\ .'
to consider the pyrolysis of additional nitrogen containing fuels and pure
compounds under oxidation.conditions and further to explore the interactions
of thermal and fuel NO formation mechanisms in flames.
/\
The Massachusetts Institute of Technology, under IERL-RTP sponsorship, is
investigating the formation of soot and polycyclic aromatic hydrocarbons
(PCAH) in combustion systems. The objective of the study is the assessment of
the production of particulate organic matter (soot and organic compounds) in
well defined yet relevant combustion systems. Tests are being conducted on
both laminar and turbulent atmospheric diffusion flames. Acetylene-oxygen
laminar flat flame tests will be1 conducted at full equivalence ratios and
burner exit velocities, and data will be taken on species concentrations,
temperature profiles, and particle concentration and size distribution as a
function of position in the flame. A water-cooled sampling probe will produce
data on mass loadings of soot, number concentration, and size distribution of
soot and concentrations of PCAH species in the turbulent diffusion flame. The
apparatus is capable of burning either liquid or gaseous fuels with variation
of equivalence ratios and full injection modes. Preliminary runs at an equiva-
lence ratio of 1.0 showed a 4 order of magnitude increase in exhaust gas soot
loading with a decrease in atomizing air pressure from 20 to 10 psig. This
illustrates the extreme sensitivity of soot emissions and possibly PCAH emissions
to changes in combustor firing practices in an effort to reduce NO .
A
Further studies by the Massachusetts Institute of Technology under IERL-
RTP grant on the fate of coal nitrogen during pyrolysis and oxidation are now
in progress. The overall objective of this study is the determination of the
distribution of fuel nitrogen between char and volatiles and the fate of the
char and volatiles under simulated combustion conditions. Tests are conducted
on a controlled atmosphere isothermal furnace from which pyrolysis or oxidation
products are withdrawn with a water-cooled probe. Long residence times are
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simulated by allowing the coal particle to free fall through the furnace, and
short residence times require a high preheated gas flowrate. A swelling
bituminous coal and a nonswelling lignite of fuel nitrogen content 1.04 and
0.51 percent, respectively, have been selected. Preliminary data indicate
that: (1) fuel nitrogen devolatilization is kinetically controlled, (2)
significant amounts of nitrogen (about 70 percent at 1750°K) may remain in the
char after devolatilization, (3) NO formation decreases with increasing fuel/
air equivalence ratios, and (4) as much as 40 percent of the nitrogen may
remain in the char at fuel/air equivalence ratios greater than 1.5. From these
findings, current data indicate that nitrogen in the char may contribute
significantly to NO emissions at temperatures below 1750°K but less at higher
A
temperatures.
Under an IERL-RTP grant, the University of Arizona is conducting an
experimental program to study the potential impact of fuel desulfurization on
the formation of NO emissions. Laboratory flat flame experiments showed that.
s\
the presence of sulfur may inhibit the formation of thermal NO . Data were
/\
inconclusive in establishing a relationship between fuel sulfur and fuel
nitrogen conversion to NO . Further tests are presently being run on a larger
A
furnace with swirling flames. These tests utilize dopants for both nitrogen
and sulfur compounds in oil flames.
COMBUSTION AERODYNAMICS
Although combustion chemistry is responsible for the formation and destruc-
tion of pollutants, the actual conditions that exist in the flame zone are a
strong function of the physical processes of combustion. Most practical com-
bustors operate with diffusion flames where the fuel and air are introduced
separately and mixing depends on the manner of introduction.
The flame zone is not of homogeneous composition; therefore, it is neces-
sary to understand the role of combustion aerodynamics in pollutant formation.
United Technology Research Center (UTRC) is under contract to IERL-RTP to
investigate the interaction of aerodynamics and combustion chemistry (in an
idealized single-burner combustor) as a function of fuel type and various in-
let parameters. During this study, detailed mapping of the local chemical
composition, temperature, velocity, and turbulence profiles is being accom-
plished. Initial studies, using in-situ probes, investigated air preheat,
stoichiometry and flame swirl. Further testing utilizing a laser-doppler-
velocimeter (LDV) has recently been completed on gas- and liquid-fuel flames.
The LDV allows for the determination of turbulent flame structure without
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probe interference, and it measures turbulence level as well as mean velocity.
Tests using the LDV on gas and liquid flames investigated the effect of swirl,
fuel/air velocities and pressure level on the flow and NO formation. Results
A
showed that large-scale turbulence was dominating both combustion and pollutant
formation. These results indicate a need to identify the interaction of
turbulence reaction kinetics within the flow field. Optical methods were uti-
lized to measure the liquid spray characteristics from the injection of pro-
pane, iso-octane, and distillate oil. The results yielded good data on spray
pattern, velocity profiles and droplet particle spacing. Reports on the UTRC -
experimental studies are due out soon. The UTRC experimental program is part
of a coordinated experimental/analytical program to produce tools with which
to evaluate practical test results. The analytical portion of the UTRC program
is investigating the use of flow field computations to describe recirculating
combustion flow. In addition, UTRC has been working to improve a computer
code for rigorous solution of the Navier-Stokes flow equations. The major
effort has been on improving the turbulence model and comparing model predictions
with cold-flow and hot-flow furnace data. To date, simple chemical kinetics
have been used. The strong influences of boundary conditions in general and
of radial inlet profiles in particular on predictions have been demonstrated.
It appears that advances in numerical differencing techniques will be needed
before a generally applicable method can be used to develop a simplified
treatment of combustion chemistry and aerodynamics.
APPLICATION FOR COMBUSTION CONTROL
A contractor is being selected to plan and execute a 3 year effort to in-
tegrate the results of prior and on-going fundamental studies and initiate new
studies of combustion and combustion-generated air pollution. The new program,
scheduled for an early 1977 start-up, will consolidate the diverse fundamental
studies projects into one large highly coordinated program whose efforts will
be focused on application to field- and pilot-scale test results. The control
program has progressed to the stage where preferred approaches to NO control
have been well defined. Consequently, the fundamental studies program is
being structured to focus on needs in data interpretation, generation of new
research and development directions, and operational problems.
FUEL PROCESSES
The programs being conducted under the supervision and direction of the
Fuel Process Branch are a part of the Energy Assessment and Control Division's
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5 year study of multimedia-environmental-assessment/control-technology-develop-
ment for fossil-fuel-based technologies. These programs encompass two major
areas: physical and chemical coal cleaning, and synthetic fuels from coal.
Contracts supported within these two major areas have the following purposes:
- to conduct a multimedia (air, water, and land quality) environmental
assessment of specific coal cleaning and synthetic fuels from coal
processes;
- to develop control technology for these processes; and
- to develop physical and chemical coal cleaning techniques.
The multimedia environmental assessment contracts are studies designed to
identify and quantify pollutants that would be discharged to the environment,
and to determine the level of pollutant control achievable, through the use of
best available control technology and technology likely to be developed in the
near future, for specific coal cleaning and synthetic fuels from coal processes.
(See following diagram.) The achievable pollutant control levels will then be
compared with existing standards, estimated multimedia environmental goals
(desirable levels to be defined by EPA), and bioassay specifications (toxicity
to biota) to define control technology priorities.
The control technology development contracts are aimed at applicability
of existing control technology, modification of existing technology, and
development of technology after specific control needs have been defined.
This technology development is being accomplished through basic and applied
research and development engineering analysis, and specific control process
development and evaluation.
Fossil Fuels—Coal
COAL CONTAMINANT CHARACTERIZATION
The use of coal depends on several factors. Environmentally, the effects
of its use on the total environment (air, water, solid effluents, land use)
are major factors. As a first step in determining these effects, the coal
constituents must be clearly and accurately defined. A multifaceted effort
toward this goal is currently underway at IERL-RTP.
The Illinois State Geological Survey was awarded a 3 year grant extension
(EPA Grant 2804403) to provide continued support for an investigation concerning
the nature, distribution and origin of mineral in coal. The program period is
April 1976 to April 1979.
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COAL
PREPARATION
COAL
PRETREATMENT
H
COAL
GASIFICATION
UTILIZATION
PURIFICATION
METHANATION
COMPRESSION
I PIPELINE
~~SNG
co
IT
CATALYST
,r
1
TAOILAND "•" SEPARATOR -^ C(
• 1 • •
i~"
- * !
i
i
3NTAMINATED JL
WATER "^
1
1
SEPARATOR
WATER
TREATMENT
"1
1
1
ij
il
U
i i
1 i
CATALYST
SOLUTION ^
REGENERATOR ""^ R
SULFUR ^ TAILGAS
ECOVERY "*• TREATMENT
NOTE: NOT ALL STREAMS ARE SHOWN.
Hypothetical simplified gasification flow diagram.
-------
The major areas of interest which will be investigated are:
0 The mode of occurrence and distribution of trace elements and minerals
in coal.
0 The mineralogy arid genesis of iron and zinc sulfide minerals in coal
seams.
0 The washability of minerals and their constituent chemical elements by
conventional washing techniques.
The results of this work will provide the EPA with mineral distribution
maps primarily for the Illinois Basin and will generate information on the
washability of specific minerals and related.elements which can be used in
coal utilization strategies.
A number of whole coals and wash residues have been analyzed to date.
Analytical data are currently being interpreted and significant results will
be submitted in quarterly reports.
The Illinois State Geological Survey was awarded a 36 month, 138 man-
month contract (EPA Contract NO. 68-02-2130) to analyze a number of coals,
coal by-products, and coal wastes for potential pollutants, to identify the
controlling factors by which they are bound or released, and to determine their
toxicity and possible mechanisms for control. The contract period is November
1975 to November 1978.
The overall technical objectives of the program are:
0 To characterize the chemical, physical, and mineral properties of
coals, coal by-products, and coal wastes.
0 To investigate the effects of pyrolysis on the distribution of trace
elements between the volatile components and the residue.
° To provide data on the solubilities and toxicities of potential pol-
lutants contained in solid coal wastes.
Results of this work can be used to estimate the mineral solubilities for coal
wastes over a wide range of disposal environment conditions.
A number of U.S. coals will be analyzed for major, minor, and trace ele-
ments. Several of the coal samples will be demineralized with acid and analyzed
again to determine the amount of all organically combined elements. From a
pyrolysis of this mineral-matter-free coal and other experiments, a material
balance will evolve which can be used to predict a pattern of behavior for
minor and trace elements in a coal utilization system. In addition, the
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pyrolysis experiments will be used to relate the coal microstructure, surface
area, rank, and petrographic constituents to volatile emissions.
Solid wastes from a number of coal utilization processes will also be
analyzed for potentially hazardous materials. Standard fish toxicity tests
will be used to determine the biological toxicity of the water soluble consti-
tuents obtained from the solid wastes. Leachates will also be contacted with
clay or clay mixtures under both aerobic and anaerobic conditions to determine
their effectiveness in the attenuation of hazardous pollutants.
All phases of this program have been initiated to date. An analysis for
three coals, both whole and demineralized samples, has been completed. The
first of three annual reports is to be completed by January 1, 1977.
The Illinois State Geological Survey was awarded an 18 month contract
(EPA Contract No. 68-02-1472) to analyze some 170 U.S. coals and develop an
extensive survey of the concentration and distribution of the trace and minor
elements present. The contract period was June 27, 1974 to December 26, 19.75.
The overall technical objectives of this contract were to perform an ex-
tensive survey of over 40 trace and minor elements, to determine their nature
of association in the coal matrix, and to assess the vertical and areal dis-
tribution of these elements in a given coal seam.
This program provides the EPA with a complete and accurate survey of the
concentration and distribution of potentially hazardous trace elements 1n
coals from the major producing areas in the United States. It also furnishes
some of the basic information necessary to judge the environmental soundness
of various coal utilization systems.
All laboratory work has beer completed. Much of the data has been com-
piled and the final report will be issued in mid-1977.
COAL CLEANING
The coal cleaning program includes both physical and chemical approaches
to the cleaning of coal. This program includes the multimedia environmental
assessment of specific processes presently used or being developed, and the
development and demonstration of new processes for the removal of sulfur and
other contaminants from coal.
The contract technology development portion of the coal cleaning program
will include characterizing coal with respect to polluting constituents, de-
fining the technical and economic suitability of cleaning processes to these
coals, and then developing advanced cleaning processes from bench-scale through
pilot-scale to make them commercially available.
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Environmental Assessment
A 3 year contract (EPA Contract No. 68-02-2163) was awarded to Battelle-
Columbus to perform a comprehensive assessment of environmental pollution
which results from coal transportation, coal storage, coal, cleaning (physical
and chemical), and waste disposal. The contract period is July 1976 to July
1979.
The overall technical objectives for this contract are:
0 To assess the environmental discharges from coal cleaning and related
operations by conducting actual plant tests for all major processes in
use, and by a detailed study of the processes under development.
0 To develop a strategy for the evaluation of those processes which
utilize clean coal and could influence the overall environmental im-
pact of coal cleaning.
0 To generate preliminary conceptual designs for coal cleaning processes
that are environmentally more sound than existing systems.
0 To provide a revised technology overview which will include a detailed
update of all coal cleaning technology.
An environmental assessment effort will be the major emphasis of this
program and will involve the compilation of detailed process descriptions
obtained from literature, unpublished process data, and actual plant visits.
Extensive inplant testing will be conducted to establish emission levels of
these pollutants and better define the process descriptions. Computer models
for each process and other information will be used to provide a comparison of
costs and performance.
Technology Development
PHYSICAL/MECHANICAL COAL CLEANING—The Environmental Protection Agency
and the United States Bureau of Mines have had a series of interagency agreements
to cooperatively assess the economic and environmental impact that coal clean-
ing technology can have on the coal utilization industry. Several contracts
have been awarded to accomplish the following overall technical objectives for
the program:
0 Determine the sulfur (and ash) reduction potential of U.S. coals.
0 Develop and demonstrate the two-stage flotation technique for separat-
ing pyrite from fine size coal.
0 Determine the reaction mechanisms and potential environmental problems
for the Bureau of Mines Coal-Pyrite Flotation Process.
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0 Evaluate the use of magnetic separation in coal preparation.
0 Assess the impact that physical coal cleaning will have on sulfur
oxide emissions from stationary combustion sources.
0 Appraise control techniques for the treatment of water effluents from
coal processing plants.
0 Develop a computerized model which will predict the performance for a
given coal preparation plant configuration.
0 Design a 10 to 25 tph coal preparation pilot plant.
Much of this work has been completed, and each study is listed below.
(1) Washability Evaluation of U.S. Coals (Bureau of Mines, on-going
project since February 1965)
(2) Adsorption-Desorption Reactions in the Desulfurization of Coal by a
Pyrite Flotation Technique'(University of Utah, August 1974)—This
work will be continued during the next year along with the study of
residual reagents left in the water and their potential effect on .
subsequent coal flotation in an operating preparation plant.
(3) Pyrite Flotation C'ircuit Lancashire No. 25 Plant No. 25 (Heyl and Patterson,
Inc., November 1974) (demonstration of the two-stage flotation
technique)
(4) Engineering/Economic Analyses of Coal Preparation with SOp Cleanup
Processes for Keeping Higher-Sulfur Coals in the Energy Market
(Hoffman-Muntmer Corp., June 1975)
(5) Control of Black Water in Coal Preparation Plant Recycle and Dis-
charge (Pennsylvania State University, June 1975)
(6) Surface Phenomena in the Dewatering of Coal (Syracuse University,
June 1975)
(7) Computer Simulation of Coal Preparation Plants (University of Pitts-
burgh, December 1975)
(8) Magnetite Recovery in Coal Hashing by High Gradient Magnetic Separa-
tion (Massachusetts Institute of Technology, March 1976)
(9) High Gradient Magnetic Separation for Removal of Inorganic Sulfur
from Coal (General Electric Co., March 1976)
(10) Recovery of Fine Size Waste Coal (University of Alabama, March 1976)
(11) Professional Services for Design and Engineering Data for the Coal
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Preparation Process Facility. Equipment, and Structural Support
(Birtley Engineering Corp., April 1976)
(12) Architect-Engineering Services (WilHam-Trebilcock-Whitehead, July
1976)
(13) Homer City Coal Cleaning Plant Demonstration, Pennsylvania Electric
Cp_._--This cooperative agreement (between the EPA, the Pennsylvania
Electric Co. [a subsidiary of General Public Utilities Corp.], and
the New York State Electric and Gas Corp.) outlines a program to
test and evaluate the use of physical coal cleaning to meet sulfur
dioxide (S02) and other possible air pollution emission regulations.
The test and evaluation programs will focus on the advanced tech-
nology coal preparation plant being built at the Homer City Generat-
ing Complex. The program, as initially outlined, will have a 4
year term which will begin in mid-1977.
The overall technical objectives for the Homer City program are to:
0 Demonstrate the effectiveness of the multiproduct coal cleaning opera-
tion for meeting Federal and state SOo emission regulations.
0 Develop the performance and cost information needed by others for the
optimum use of physical coal cleaning as a pollution control strategy. ...
0 Test alternative coal preparation techniques.
0 Assess the environmental factors associated with coal cleaning including
those affecting air and water quality and solid waste disposal.
The first step in accomplishing the program objectives is to finish the
construction of the coal preparation plant and bring it into full production.
This will be accomplished in two stages. Initially the facility to produce
moderate-sulfur coal for the two existing boilers will be made operational. In
conjunction with this, a second section of the facility will be constructed
and brought on line to produce low-sulfur coal for the new boiler (estimated
completion date is October 1977).
The coal preparation facility is currently under construction, and the
statistical analysis review of sampling procedures in nearly complete.
Actual inplant testing will begin with a baseline study to determine ex-
isting pollutant levels and power plant performance. Upon completion of the
coal cleaning facility, an initial operating period will be allowed to insure
the reliability of test results. Accumulated test data will be used to charac-
terize the performance of the coal preparation and power plants under a
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variety of conditions. Operating and maintenance data will also be collected to
evaluate the equipment and operating costs for all areas of the generating
complex.
CHEMICAL COAL CLEANING--The objective of this program area is to develop
and demonstrate advanced chemical coal cleaning techniques that would increase
the availability of lower-sulfur coals that upon combustion would meet various
state and Federal regulations. Chemical coal cleaning techniques would pro-
vide an alternative control option to smaller combustion sources that, because
of cost on physical restrictions, may not be able to use other alternative
control techniques. Technologies now under development and evaluation include:
0 Meyers Process—TRW
0 Flash Desulfurization—Institute of Gas Technology
0 Hydrothermally Treated Coal—Battelle
0 Microwave Desulfurization—General Electric.
MEYERS PROCESS—TRW Systems and Energy Group was awarded a 17 month con-
tract (EPA Contract No. 68-02-1880) to design and construct a Reactor Test
Unit (RTU) to demonstrate the Meyers Process, the chemical removal of pyritic
sulfur from coal. Support work for this program is currently being conducted
by TRW under EPA Contract No. 68-02-2121. The program period for the construc-
tion of the RTU is September 1975 to January 1977. '
Overall technical objectives for this contract are:
0 To design and construct a Reactor Test Unit (at TRW's Capistrano Test .
Site) which will be capable of continuous operation at the nominal rate
of 250 to 750 Ibs of coal per hour,
0 To demonstrate the operability and economic feasibility of the Meyers
Process for chemical removal of pyritic sulfur from coal, and
0 To provide the design data base needed for the commercialization of
this process.
A final design and a construction cost estimate was prepared by a subcon-
tractor, the Ehrhart Division of Procon. After EPA approval of the design, a
detailed design package suitable for fixed-price construction bidding was pre-
pared by Ehrhart. All process equipment and major materials will be procured
by Ehrhart and delivered to TRW's Capistrano Test Site by the various vendors.
TRW will provide design and procurement interface and technical direction dur-
ing this activity. Test planning data will be obtained at the bench-scale
level for the two coals which are selected for plant operation.
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TRW has improved the site, at its own expense, for the Reactor Test Unit.
A construction subcontractor was selected through competitive bidding. The
RTU will be constructed, with construction monitoring to be provided by TRW.
Construction of the RTU was initiated in October 1976. The subcontractor
estimated completion of the plant by mid-March 1977. This estimate assumes no
delays in the construction due to weather. All equipment, materials, and man-
power to maintain the project are on the job site.
Concurrent with the RTU construction contract, TRW Systems and Energy
Group was awarded a contract (EPA Contract NO. 68-02-2121) to define bench-
scale operating parameters and to provide engineering analysis and evaluation
for the Meyers Process pilot plant. The program period for the laboratory
work is November 1975 to July 1977.
Overall technical objectives for this program are to:
0 Support the RTU program.
0 Investigate the potential of using chemical desulfurization, the
Meyers Process, to adequately reduce the sulfur content in several grades
of coal which will be used in the pilot program.
0 Identify and evaluate possible sulfur recovery schemes.
0 Develop acceptable storage methods for the sulfur products which will
be produced.
0 Determine the environmental discharges and control technology applica-
bility to eliminate adverse effects.
FLASH DESULFURIZATION—The Institute of Gas Technology (IGT) was awarded
an EPA contract (No. 68-02-2126) to develop a process for the treatment of coal
to produce an environmentally acceptable solid fossil-fuel product.
The objective of the present program, a continuation of two previous EPA .
contracts, is to determine the operating conditions for the key steps in the
IGT process to desulfurize coal by thermal and chemical means on both a bench-
and pilot-scale unit. In the initial contract, lime was used to remove the
sulfur from coal in a fluidized-bed reactor which subjected the feed to almost
instantaneous heatups. Pyritic sulfur was removed to low levels; however, the
quantity of organic sulfur removal was not greater than the coal devolatiliza-
tion rate. Studies indicated that rapid heatup tended to inhibit organic sul-
fur removal by fixing it into the coal lattice. Consequently, the second
contract was directed toward a program where the equipment would give control-
led heatup rates.
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A thermobalance, using small samples and relatively high gas flow, was
used to establish the parameters for pretreatment of various coals in the re-
designed batch reactor. The results of the program indicated promise for the
process and led to the present contract for further study.
On the laboratory scale, a number of coals will be investigated to deter-
mine their susceptibility to desulfurization by chemical and thermal treatment.
The most satisfactory mode for the process will be determined on the
small bench-scale and will be extended further to a 10 inch diameter pilot-
scale reactor to define the scale-up parameters. The entire processing scheme
will be integrated and the overall conceptual design of a Process Development
Unit (PDU) will be prepared for a 10 ton/day facility. A technical and economic
evaluation of the process will be performed.
The approach which will be used to accomplish the program objectives is
defined in six phases: Coal Selection and Characterization; Laboratory Ex-
perimentation; Reactivity and Kinetic Studies; Product and By-Product Charac- '
terization; Process Development Unit (PDU) Design; and Technical and Economic
Evaluation.
Phase I is completed. Coals selected were: Western Kentucky No. 9,
Illinois No. 6, Pittsburgh seam West Virginia, and Pittsburgh seam Pennsylvania.
Specifications for pretreatment include: operating temperature--750°F; mini-
mum residence time—30 minutes; oxygen feed—1 scf Op/lb dry feed; and fluid-
ization velocity—1 ft/sec, measured at operating conditions.
Phase II is completed. With pretreatment, sulfur removal with subsequent
hydrotreating is more effective to prevent agglomeration and decreases hydrogen
treatment requirements.
Phases III and IV have been initiated. Thermobalance testing is complete.
Batch reactor testing is continuing, as are exploratory tests on the pilot
unit. The pretreatment of the 10 inch unit has been defined and exploratory
tests on the unit have begun. Operations are on schedule and operability
proven in two sizes of equipment. In analyzing the thermobalance tests, the
benefit of lime is minimal and the treated material recovered is consistently
greater in the no-lime tests than in the tests using the lime-pretreated coal
mixture.
HYDROTHERMALLY TREATED COAL—Battelle-Columbus Laboratories was awarded a
contract (EPA Contract No. 68-02-2187) to assess the economic and environ-
mental impact that can be expected from coal desulfurization by the Hydro-
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thermal Coal Process (HCP). The contract period is October 1976 through
November 1978.
The overall technical objectives for this program are:
0 To improve the economic viability of the HCP by reducing the cost of
two segments of the process (leachant regeneration and solid/liquid
separation), and
0 To evaluate the use of hydrothermally treated coals in conventional
boilers and furnaces.
The first phase of this program will investigate the use of iron oxide
and zinc oxide to regenerate spent leachant and facilitate recycle. The
metallic oxides are efficient in removing sulfide from spent leachates, but
do not remove oxidized sulfur ions or trace elements. Oxidized sulfur ions
inhibit the desulfurization process and trace elements (if accumulated) could
contaminate the coal product. A series of recycle experiments will be con-
ducted to determine how many times the regenerated liquor can be recycled and
the possible need for removal of a side-stream to prevent product contamina-
tion. Additional tests will also be made to determine the most effective
method to prohibit sulfide oxidation or to reduce the oxidized forms during
the regeneration step.
A second aspect of the economic evaluation will be to investigate the
relationship between particle size and water requirements in the solid/liquid
separation segment of the process. Larger size coals may reduce the amount of
entrained water leaving the process and thus reduce the cost for makeup water.
Vacuum filtration, centrifugal filtration, and oil agglomeration will also be
explored as possible methods to reduce water contaminant.
Finally, the results of these various studies will be integrated into the
overall Hydrothermal Coal Process and an economic analysis will be conducted
to define optimum operating parameters.
In the second phase, selected hydrothermally treated coals will be
evaluated in stoker, pulverized coal, and coal-slurry combustion units. Both
raw and conventionally cleaned coals will be made for sulfur and trace elements
to evaluate the HCP as a control technology for sulfur emissions and to assess
the overall environmental impact it will have.
The work plan for this project has been revised and submitted for ap-
proval. The experimental program was started in November 1976. Combustion
studies have been postponed until additional funding is made available.
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MICROWAVE DESULFURIZATION—The General Electric Company was awarded a con-
tract (EPA Contract No. 68-02-2172) to study the basic mechanism of microwave
treatment of coal as established by that Company in order to better define the;
technical and economic merits of the system as an environmental control sys-
tem. This study will involve a comprehensive experimental program for inves-
tigation of process parameters in order to identify the technical advantages
and disadvantages of the process. The program period for this effort is
August 1976 through November 1977.
SYNTHETIC FUELS
IERL-RTP is very much involved in the emerging industry of coal conversion
or synthetic fuels. There is a great need for on-going environmental research
and development in this area. The synthetic fuel industry will consist of
very large and complex plants and will involve great discharge quantities,
large consumptions of water, air, and fuel, and massive effects on extraction
of resources in relatively small areas. It thus presents a number of perplex-
ing questions concerning the environmental impact of commercial technology
still in its early stages.
Types, compositions, and quantities of discharge streams have not yet
been completely identified; therefore, attendant pollutants that might result
in significant health effects or other environmental effects are still unknown.
Full control needs still await a reasonable technology and pollution determina-
tion. The degree of control of discharges from existing control techniques
has not been quantified. lERL-RTP's programs for environmental assessment and
control technology development are currently addressing these problems.
Cameron Engineers, Inc. has been awarded a 1 year contract to provide
systems analysis and program support to the IERL-RTP Synthetic Fuels program,
primarily in the areas of coal preparation, coal liquefaction, coal gasifica-
tion, and shale oil processing. The contract is designed to provide EPA with
a viewpoint independent from that of other EPA contractors working in the en-
vironmental assessment, environmental control technology development, and
process technology development areas. Technical information is being pro-
vided through background functions (such as literature surveys and reviews of
technical reports), coordination functions, communication functions, and pro-
gram planning support.
Environmental Assessment
Water Purification Associates was awarded a contract (EPA Contract No.
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68-03-2207) to recommend measures which will minimize water pollution and con-
sumption by coal conversion plants and to determine the general environmental
impact on water that can be expected from the commercialization of synthetic
fuel projects in the western coal and oil shale bearing regions. The program
period is June 1975 to October 1978.
The overall technical objectives for the program are to:
0 Assess the general water use and pollution control alternatives for
specific coal gasification and liquefaction processes.
0 Determine, from an analysis of 40 to 50 commercial-scale synthetic
fuel plants anticipated for the western U.S.., the environmental impacts
that can be expected from water-related site and process character-
istics,
0 Ascertain the level and mix of synthetic fuel industry that could be
supported by 1990, based on a projection of locally available fresh
and saline surface and groundwaters.
HIGH-BTU GASIFICATION—Individual reports and a summary report have been
prepared on all synthetic fuels technology reviewed to date. Also available
are reports on possible or probable trace elements from gasification processes
and specific listings of probable pollutants from processes such as the Hygas
process. Two more trace element reports are in preparation. Individual re-
ports have included the high-Btu processes: Lurgi, Synthane, Bi-Gas, Hygas,
and C02 Acceptor.
Extensive work will begin soon on an in-depth assessment of specific coal
processes for environmental impacts associated with high-Btu conversion proc-
esses. This will include a complete environmental assessment of emissions and
.effects. An inhouse gas cleaning test rig is planned, and new data acquisi-
tion capability is being developed.
LOW-BTU GASIFICATION—Considerable effort is being exerted toward a com-
prehensive environmental assessment of the low-Btu gasification process.
Radian has been awarded a contract (EPA Contract No. 68-02-2147) to per-
form an environmental assessment of low- (and intermediate-) Btu gasification
and its utilization. Contract period is March 1976 to March 1979.
The overall technical objectives of this contract are to:
0 Perform a comprehensive multimedia environmental assessment of coal
conversion processes which produce, and end-use options which consume,
low- and/or intermediate-Btu gases.
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0 Define the control techniques which will have to be applied to guaran-
tee the environmental acceptability of this technology.
A goal of this study is the development of a predictive model which can be
used to predict impacts and specify control needs for a given facility based on
feedstock properties, process configurations, operating conditions, and regula-
tory constraints.
The environmental assessment will involve a detailed process engineering
analysis of all feasible options for producing low-Btu gas from coal, and
methods of utilizing the resulting product gases. A unit operations or modu-
lar type analysis will be used in this assessment to facilitate comparisons of
alternative process configurations.
Factors such as site characteristics and availability, the necessity for
the development of new analytical methods, and alternative approaches will be
considered in order to determine the most cost-effective approaches to be used
in obtaining the required basic process data. Tests are planned at existing
commercial plants and pilot plants in the U.S. and abroad.
Eleven technical directives (TDs) have been issued relative to this
contract which serve to further define and guide the program effort. These
include:
TD-1 - Work Plan and Support
TD-2 - Preparation for Data Acquisition
TD-3 - Initial Control Technology Assessment Reports
TDr4 - Initiation of Test Programs Development
TD-5 - Initiation of Technology Overviews
TD-6 - Initiate Preliminary Impact Assessments
TD-7 - Program Support Data Base
TD-8 - Data Base Analysis and Process Engineering
TD-9, - General Support Activities
TD-10 - Continued Development of a Test Manual
The United Technologies Research Center was awarded a contract (EPA Con-
tract No. 68-02-2199) to perform a fuel gas environmental impact study. The
contract period is from September 1976 to October 1977.
The objective of the study is to evaluate the technical, economic, and
environmental intrusion characteristics of integrated coal gasification/sulfur
removal/combined-cycle power systems utilizing additional gasifier types that
were not studied in the previous contract. The approach to meeting the
objective includes the following areas of study.
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0 Advanced gasification systems—A comparison of advanced technology
gasifiers: one having integral cleanup of sulfur compounds; the
other requiring external cleanup.
0 Gasifier effluent models—Gasifier performance for different operat-
ing conditions and an evaluation of a two-stage entrained flow type
(BCR) gasifier for both air- and oxygen-blown operations.
0 Comparison of BCR type gasifier--An integrated coal gasification-
advanced cycle power generating system.
0 Cleanup system identification—Low- and high-temperature cleanup systems.
0 Define new integrated systems—Combination of the gasifier/cleanup
systems and an integrated combined cycle power system.
0 Revision of previous systems studied under the contract.
0 Environmental definition.
Results of the previous contract showed the potential for low-cost, en-
vironmentally acceptable electric power from integrated power systems consist-
ing of coal gasifiers, low- and high-temperature sulfur cleanup processes, and
combined cycle generating systems.
Under the present contract, the initial integration work has begun. Pre-
liminary air- and oxygen-blown BCR data have been compared.
The Research Triangle Institute (RTI) has been awarded a research grant
(R804979) to study potential pollutant production from synthetic fuels opera-
tions. The 5 year program is intended to perform both experimental and
analytical studies. The program will include documentation of the specific
chemical species present in various effluents from synthetic fuels processes
along with a semiquantitative determination of their concentrations in the
various process streams. The pollutants will be ranked in the order of their
potential environmental hazard considering such factors as concentration,
treatment, disposition, dispersion, and dilution of the effluent stream, and
ultimate pathways to human exposure.
In addition, a catalog of kinetic data pertaining to the rates of forma-
tion of the pollutants of significance will be generated. This catalog will
be useful in suggesting optimum reactor conditions to minimize the overall ex-
pense of emission or effluent control. As part of EPA's overall clean fuels
program, the operating conditions which apparently minimize pollutant formation
can then be subjected to experimental confirmation on a pilot-scale continuous
;gasifier.
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During the first year, attention will be concentrated on coal gasification.
A laboratory-scale gasification reactor of sufficient flexibility to simulate
the time/temperature history of feed material proceeding through commercial
processes will be designed, constructed, and placed in operation. (See follow-
ing illustration.) Instrumentation will be provided to monitor and control
temperature and pressure during gasification as well as the composition of feed
gases to the gasifier. In addition, a sampling train will be designed and
applied to the acquisition of char, tars and oils, water, and gases from the
reactor. Prior to operation of the experimental reactor, analytical techniques
will be developed and calibrated for the determination of synthetic fuels
pollutants utilizing samples from actual gasification operations. Methods
and techniques of determining kinetic parameters will be demonstrated, and
analytical requirements for the successful completion of kinetic experiments
will be developed.
Efforts during the following years are projected to involve application
of the methods and techniques to the screening of many coals and to the in-
vestigation of other synthetic fuels technologies.
This program began on November 1, 1976.
Control Technology Development
In addition to control technology development work being done under con-
tracts discussed as part of the environmental assessment program, several
other control technology development contracts are underway and are discussed
below.
North Carolina State University, supported by design capabilities provided
by Aerotherm and the Institute of Gas Technology (EPA Contract 68-02-2187), has
been awarded a three year grant (R804811) to provide and operate a facility for
studying primarily the environmental factors in raw and acid gas cleanup asso-
ciated with gasification. Tasks included under this grant are:
0 Raw and acid gas cleanup facility.
Bench-scale at NCSU for generic type acid gas cleanup system.
0 Design of system (Aerotherm with subcontract to IGT for gasifier).
Gasifier: double-walled, fluidized-bed, 100 psig.
Synthetic gas mixtures: bottled.
Gas cleanup: modular approach, methanql first.
Data acquisition: sophisticated.
0 Fabrication.
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Concept of RTI reactor facility and sampling manifold.
-------
6 Operations.
Shakedown: Aerotherm.
Test Program: NCSU.
The contract schedule provides for the design package to be available early
in November and finalized in December, with installation during the summer of
1977.
Work under an IERL-RTP 5 year grant (R804917) is being initiated by The
University of North Carolina at Chapel Hill to assess biological and chemical
treatment of wastewaters from fuel conversion, to determine environmental im-
pact and health effects of treated waters, and to conduct bench-scale studies
for developing design criteria. The system is for generic water treatment
approaches. The research will include:
0 Literature review.
0 Modeling of organic compounds biodegradibility.
0 Biological treatability in activated sludge system.
0 Alternative physical/chemical treatments.
0 Animal toxicology studies.
0 Treatability of composite waste streams.
0 Design criteria for continuous treatment.
Battelle-Columbus Laboratories was awarded a contract (EPA Contract 68-02-
2112), initially for a 12 month period, to conduct a literature survey and
evaluate past, present, and future control techniques for the removal of poten-
tial pollutant contaminants directly from solid and liquid fuels prior to
combustion.
The results from this work will provide the EPA with a summary of control
techniques which can be used in environmental control strategies for general
fuel utilization processes.
Those techniques which show the most promise will be evaluated from a
thermodynamic and kinetic viewpoint. Feasible methods will be ranked with
respect to their potential removal efficiency for specific contaminants. In
conjunction with this phase, laboratory tests may be required to fill data
gaps and to remove ambiguities found in the literature survey.
All phases of this program are nearly complete, and efforts have resulted
in two EPA reports:
0 EPA-600/2-76-177a, "Fuel Contaminants: Volume 1. Chemistry," July 1976.
0 EPA-600/2-76-177b, "Fuel Contaminants: Volume 2. Removal Technology
Evaluation," September 1976.
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Laboratory support studies are continuing for several removal techniques.
Results from these preliminary studies are presently being written into a re-
port. A continuing program in these and other selected areas is anticipated.
Catalytic, Inc., has been awarded a contract (EPA No. 68-02-2167) to de-
velop control technology for the products and by-products of fuel conversion/
fuel utilization systems based on coal. The contract period is September 1976
to September 1979. The overall technical objectives of this contract are to:
0 Establish general processing schemes which will produce acceptable
fuels and marketable by-products from coal.
0 Assess the potential emission problems which could be incurred in each
module of the above processes.
0 Develop control technology for the recovery or destruction of these
pollutants. This will include: utilization of existing processes;
evaluation of developing processes; the identification of the need for,
and the development of, new technologies.
Results from this work will enable the EPA to determine the overall con-
trol technology that is required to restrict pollutants to the desired levels
during the conversion of coal to marketable products and by-products.
The approach which will be used to accomplish the program objectives is
defined in six phases, summarized as follows:
Phase I. Project overview and compilation of published process informa-
tion and control technology to provide initial estimates of potential
pollution problems.
Phase II. Identification of pollutant problems, control needs, and new
data requirements for processes to produce specific marketable products.
Phase III. Assessment, from information in Phase II, of existing and
developmental stage technology and, if necessary, consideration for the
development of new technologies.
Phase IV. Development of the control technology requirements identified
in Phase III on bench scale and testing of those showing promise on a
pilot-plant scale.
Phase V. Preliminary design and economic evaluation for those processes
newly developed.
Phase VI. General support studies.
Phases I and II have been initiated. It is estimated that Phase I should
be completed by February 1977. Three technical directives (TDs) have been
issued:
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TD-1: Work Plan and Support
TD-2: Support for Standards Development
TD-3: Overview Report
Fossil Fuels—Oil
OIL COMPOSITION
As with other fuels, the first important step is determining the oil's
composition, especially regarding potential pollutants. A literature survey
has collected and analyzed available data on domestic and imported crude oils.
these data are supplying the initial basis for an inventory of potential
pollutants whose fate must be followed in further oil processing and utilization.
OIL TREATMENT/PROCESSING
An area closely related to physical and chemical coal cleaning for which
the Fuel Process Branch is funding research is liquid fuels cleaning. This
includes demetalization, desulfurization, denitrogenation, and removal of
trace metals and halogens. Studies presently being conducted by Hydrocarbon
Research, Inc., and the Massachusetts Institute of Technology are aimed at de-
termining reaction mechanisms and kinetics, developing catalysts, and evaluat-
ing processes for contaminant removal from liquid fuels.
Under EPA Contract 68-02-0293, Hydrocarbon Research, Inc., undertook a
project to develop a low-cost scavenger catalyst to remove contaminant metals
from petroleum resids prior to desulfurization with commercial hydrodesulfur-
ization (HDS) catalysts. The contract is scheduled"for completion in
July 1977.
The work was divided into five phases. The objectives of each phase are
defined as follows:
Phase I, Develop a low-cost demetallization catalyst for the removal of
contaminant metals from heavy residual oils.
Phase II. Optimize the promoter metal level on the catalyst and explore
commercial capabilities to produce this catalyst.
Phase III. Optimize the demetallization and desulfurization steps in pro-
ducing low-sulfur fuel oils in order to obtain more accurate cost figures.
Phase IV. Join in a cooperative effort with the U.S.S.R. to gain knowl-
edge of the technical status of the demetallization of residual oils in
each country.
Phase V. Evaluate the denitrogenation catalyst on coal liquids and shale
oil.
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All work in Phases I, II, and III has been completed and final reports
issued. All experimental work on Phase IV has been completed and a final re-
port will be issued in 1977. Phase V work is proceeding and completion is
scheduled for July 1977.
Under grant (EPA Grant No. R-800897), the Department of Chemical Engineer-
ing of the Massachusetts Institute of Technology is continuing studies on
catalytic desulfurization and denitrogenation. The time period for this grant
is August 1975 to July 1978.
Under a previous grant, the Massachusetts Institute of Technology com-
pleted an initial study in July 1975 on catalytic desulfurization and denitro-
genation. The purpose of that study was to determine the implications of
thermodynamics for hydrodenitrogenation (HDN) and to determine the effect of
thermodynamics in pyridine HDN.
The objective of the present grant is to obtain a clear understanding of
the ways in which HDS and HDN reactions interact with each other in the pres-
ence of representative hydrocarbon feedstocks, on industrial catalysts, and
under practical hydroprocessing conditions. It is hoped that this study will
define optimized conditions for nitrogen removal from liquid fuels derived
from coal and oil shale.
Procedures for sulfiding the catalyst were designed to produce a standard
state of catalytic activity in the reactor at the beginning of each run. Ex-
perimental investigations of quinoline-HDN under industrial reaction conditions
were continued and further studies will investigate the ramifications of the
test results.
ADVANCED PROCESSES
Fluidized-Bed Combustion Processes
A vital element of the National Program on Fluidized-Bed Combustion (FBC)
of coal for space-heating, steam-generation, and power-generation applications
is the EPA program on the environmental characterization and control of this
process. The goal of the EPA's FBC program is to obtain all necessary environ-
mental data over the full range of operating variables for all variations of
the FBC process.
The EPA program consists of tasks on environmental assessment, comprehen-
sive analysis of emissions, and control technology development.
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FLUIDIZED-BED COMBUSTION OF COAL
Environmental Assessment
The aim of environmental assessment is to set emission goals based on
health and ecological effects of emitted pollutants and to design research, de-
velopment, and demonstration programs to develop the necessary information to
implement these goals. Comprehensive analyses of emissions from operating
units provide data on pollutants and their emission rates in order to identify
any potential problem.
The major accomplishments related to environmental assessment during the
past year included a preliminary environmental assessment program completed by
GCA Corp. and the initiation of a major contract with Battelle-Columbus Labora-
tories (BCL) for a broad environmental assessment. The preliminary assessment
by GCA indicated there were insufficient experimental data upon which to base
any conclusions concerning potential environmental problems for FBC. BCL has
made several preliminary planning studies to define needed research areas for
improving the data base. BCL has also initiated the development of a multi-
media environmental goals chart which is a concept for comparing emissions goals
for specific pollutants based on health/ecological effects. Comprehensive
analysis (CA) on a BCL 6 inch ID atmospheric pressure unit was completed and
plans were made for analysis of other units. Mitre Corp. has completed a
sampling and analysis manual for FBC units.
The Multimedia Environmental Goals Chart (MMEGC) is a concept developed
by IERL-RTP which, when completed, will provide a unified presentation, for
the/emerging energy technologies, of environmental goals in all media.
Control Technology Development
Control technology development efforts include engineering analysis, basic
and applied research and development, and specific control process development.
In the area of control technology development, the major accomplishments in-
clude process studies on the Exxon miniplant and the Argonne National Laboratory
(ANL) combustor/regenerator; studies on waste disposal, sorbent technology, and
add-on controls; and applications studies by Exxon, TVA, and Dow Chemical Co.
Exxon is conducting a program in their bench-scale fluidized-bed combustion/
regeneration equipment and miniplant facilities. The latter includes a 31.75
cm (12.5 inch) diameter pressurized combustor and a 20.32 cm (8 inch) diameter
pressurized regenerator. The 0.63 MW fluidized-bed combustion miniplant (see
following illustration) has been successfully operated for a sustained run
138
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SORBENT
IREGENERATOR
630 KW Exxon miniplant for pressurized (10 atm) fluidized-bed combustion of coal.
139
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with continuous regeneration of the sorbent that is used to control sulfur emis-
sions from the combustor. The sustained run was maintained at steady condi-
tions for 100 hours. Previous operation of the miniplant had involved the coal
combustor only, and did not include sorbent regeneration. The 100 hour run
completed shakedown of the integrated corhbustion/sorbent regeneration miniplant
system.
The run demonstrated that it is technically feasible to control sulfur
dioxide (SOp) emissions from pressurized fluidized-bed combustors with a sub-
stantial reduction in sulfur sorbent feed requirements, by means of continuous
regeneration of the spent sorbent. Such a reduction in sorbent requirements
would reduce the quantity of solid residue generated by fluidized-bed combus-
tion units, and hence would reduce the environmental impact of residue dis-
posal. The EPA New Source Performance Standard for SO^ from coal-fired
boilers was met by the miniplant combustor throughout the run. It was necessary
to add fresh sorbent (limestone) to the combustor at a feed rate only 15 to 25
percent of that which would have been required to maintain the same degree of
SOo control had sorbent regeneration not been employed. The regeneration
technique used involves reductive decomposition of the spent, sulfated sorbent
at temperatures of 1850 to 2050°F (1010 to 1120°C) in a vessel separate from
the combustor.
During the 100 hour run, the combustor pressure was held at 7.5 atmospheres
absolute (760 kPa). The combustor bed temperature was held at 1650°F (899°C),
the gas velocity passing up through the bed was 4.8 ft/sec (1.5 m/sec), and the
expanded bed depth was 11 feet (3.4 m). Pittsburgh seam coal (2 percent sul-
fur) was burned at a constant fead rate of 173 pounds (78 kg) per hour, with an
excess air level of 25 percent. The limestone sorbent feed rate (expressed in
terms of the ratio of the moles of calcium in the sorbent feed to the moles of
sulfur in the coal feed) was varied between a calcium-to-sulfur mole ratio of
zero and 1.3, averaging 0.55, as required to maintain constant bed levels in
the combustor and regenerator. The regenerator was operated at a pressure of
7.6 atmospheres absolute (770 kPa), a bed temperature of 1850°F (1010°C), a gas
velocity of 2 ft/sec (0.61 m/sec) and an expanded bed depth of 7.5 feet (2.3 m).
Sorbent was transferred from the combustor to the regenerator and back at a
rate of 100 pounds (45 kg) per hour.
Operation during the 100 hour period was smooth and stable, with no inter-
ruptions. Operating variables remained steady at the levels indicated above,
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with the exception of the variation of the sorbent feed rate. Some agglomera-
tion of bed material did take place on the regenerator distributor plate early
in the run, but the agglomerate did not worsen as the run progressed, or inter-
fere with stable operation of the systems.
Emissions of S02 from the combustor varied between 0.14 and 1.2 Ib S02/10
Btu heat input (0.06 and 0.51 g/10 J), with an average emission level of
0.63 lb/106 Btu (0.27 g/106J), compared to the EPA New Source Performance
Standard for coal-fired boilers of 1.2 Ib S02/106 Btu (0.51 g/106J). For the
2 percent sulfur coal burned, this average emission level corresponds to over
80 percent S02 removal by the limestone sorbent. As indicated previously, this
degree of control was obtained with an average calcium-to-sulfur-mole ratio of
0.55. By comparison, previous miniplant tests, in which limestone was added
to the combustor without operation of the regenerator, indicated that lime-
stone would have to be added on a "once-through" basis at a calcium-to-sulfur
mole ratio of 2.5 to 4.0 in order to achieve the same average emission level
without regeneration.
The average concentration of S02 in the off-gas from the regenerator was
0.5 percent during the run. It is desirable for this S02 level—which is the
result of the reductive decomposition of the sulfated sorbent in the regenera-
tor—to be as high as possible, to facilitate recovery of sulfur values in
future commercial combustion/regeneration systems.
ANL, in a project confunded with ERDA, is conducting laboratory- and
bench-scale work which includes testing on their 15.24 cm (6 inch) diameter
pressurized combustor and 11.43 cm (4-1/2 inch) diameter pressurized regenerator.
Past studies have shown that the NO emission from FBC is generally lower
/\
than that from conventional coal-fired boiler systems. ANL's study revealed
that an increase in operating pressure significantly reduces the NO emission
A
in FBC. An increase in excess air increases the NO emission. The operating
J\
temperature and the presence of sulfur sorbent have little or no effect. Mini-
plant operation has confirmed that at 15 percent excess air and 10 atm, the
NOX emissions equivalent to 0.2 Ibs N02/million Btu can be achieved (0.09
vg/J). This emission rate is significantly less than the current EPA standard
of 0.7 Ibs NO/million Btu (0.3 yg/J).
/\
Particulate emissions from FBC of coal have been a major concern from both
environmental and engineering standpoints. Past studies have confirmed that
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the particulate emissions are affected by many factors, such as the charac-
teristics of feed coal and sorbent, FBC geometry, heat transfer surfaces,
operating conditions, and the design of cyclones. It is recognized that
further development of particulate control technology is imperative (e.g.,
high-efficiency cyclones, electrostatic precipitators, and granular bed filters).
Supporting this finding are recent measurements from Exxon miniplant operation
which indicate that the particulate loading in the flue gas leaving the final
cyclone was no less than 0.3 grams per standard cubic meter (0.13 grains scf).
In:some cases the particulate loading was as high as 2.8 grams per standard
cubic meter (1.26 grains/scf). These particulate emissions are unsatisfactory
when compared to the current EPA emission standards of 0.09 grams per standard
cubic meter (0.04 grains/scf). These emissions are also excessive for a
stream being fed to a turbine as is contemplated for pressurized FBC.
As FBC processes develop, particulate emission is one area which must be
carefully monitored to ensure that proper control techniques are applied as
necessary to eliminate significant environmental impact.
Extensive investigations on FBC solid waste: have been started only recently
and is an area of major environmental concern. These studies are in support
of the control technology development objective of the EPA program.
Spent sorbent and coal ash are constantly withdrawn from the fluidized
bed and can be immediately discarded (once-through), or the sorbent may be
separated from the ash and reused after a regeneration process. Even with
regeneration, the sorbent material eventually becomes less reactive and a por-
tion must be discarded. The solid waste residue must be discarded in an en-
vironmentally acceptable manner to avoid problems from leaching, dusting, run-
off, air pollution, and water pollution.
Applicability of FBC to large power plant boilers has been confirmed. EPA
has participated in a study cofunded with ERDA and FEA on FBC applicability to
industrial boilers. A good potential exists for FBC technology in the chemi-
cals, paper, petroleum refining/petrochemicals and food industries. An EPA
study is underway with TVA comparing the costs of atmospheric and pressurized
FBC with conventional boilers/scrubbers.
Work was initiated by the Massachusetts Institute of Technology (MIT) in
October 1976 under a research grant with the following objectives:
0 Develop a mechanistic mathematical model for the prediction of NO
emission from coal-burning fluidized beds both at atmospheric and at
elevated pressures.
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0 Provide physical chemical input parameters for the model on the NO
formation/destruction processes by carrying out a detailed experimental
investigation using a 30 x 30 cm pilot-plant-size fluidized combustor,
a 10 cm diameter bench-scale combustor capable of operating at pres-
sures up to 10 atm, and a 7.5 cm diameter, externally heated bed for
the batch type experimental study of the chemical kinetics.
0 Provide information leading to the development of new control technol-
ogy from the experimental study on the 30 x 30 cm atmospheric pressure
fluidized combustor and by using the mechanistic model of the combus-
tion/NO-oiission processes.
ADVANCED OIL PROCESSING: FLUIDIZED-BED GASIFICATION/DESULFURIZATION OF
RESIDUAL FUEL OIL
Environmental Assessment
The environmental impacts of the Chemically Active Fluid-Bed (CAFB) process
and lime/limestone slurry flue-gas scrubbing have been compared. The basis of
comparison is a 200 MW oil-fired power plant (retrofit). The CAFB process
appears to be superior environmentally to limestone and lime slurry scrubbers.
.Sulfur removal capabilities for the processes are comparable, but the CAFB
process provides a considerable reduction in nitrogen oxide emissions and
consumes an order of magnitude less process water than do slurry scrubbing
processes. Similar nitrogen oxide control could be achieved by the addition
of special combustion equipment on the boiler. Auxiliary power requirements
are comparable at 3 to 4 percent of plant capacity. The limestone
usage is nearly identical for the processes-- about 1 mole of calcium per
mole'of sulfur removed from the fuel—but the CAFB process could potentially
reduce this consumption to half that level by optimum utilization of regen-
erative operation with sulfur recovery. The CAFB process also produces a
dry product with potential market value rather than a sludge which is diffi-
cult to handle and requires large land areas for disposal ponds. CAFB also
permits the utilization of high-metals vacuum bottoms as a fuel. Priority
problems currently are (1) reduction of stack particulate emissions, (2)
reduction of SOo emissions during abnormal operating conditions, and (3)
environmentally acceptable disposal of spent stone.
Control Technology Development
The CAFB process for gasifying and desulfurizing heavy fuel oil has been
demonstrated in a 0.75 MW continuous pilot unit at Esso Research Centre,
Abingdon, England (Esso England). The CAFB process injects heavy fuel oil
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into a shallow (about 2 feet deep) fluidized bed of lime/limestone particles
to partially oxidize, gasify, and desulfurize the oil. The continuous pilot
unit is used to fire a commercial boiler rated at 10 million Btu/hour; it
demonstrated a service factor of 95 percent during the latest run of approxi-
mately 400 hours' duration. In addition to 90 percent sulfur removal at a
calcium-to-sulfur feed ratio of 1.5 to 1, the CAFB has shown complete vanadium
removal, 75 percent removal of nickel, and 36 percent removal of sodium. A
reduction in the NOY emissions from 263 ppm (when the boiler was oil-fired) to
/>
160 ppm (when fired on the CAFB product) has been demonstrated. Economic
studies continue to show that the CAFB has the potential for becoming a viable
commercial process. The effluent from the limestone regenerator is 5 to 10
percent S02 which can be reduced to sulfur, using existing technology.
A nominal unit is being considered at San Benito, Texas.
CAFB Demonstration
The nominal rating of the combined CAFB boiler and turbine system of the
.demonstration plant is approximately 10 MWe, when high-sulfur #6 residual
oil is fed to the CAFB unit. The sulfur recovery scheme is one of several
which could be used. However, the method for recovery of sulfur is beyond the
scope of the EPA development plan. The CAFB gasifier section and regenerator
are in the same vessel, separated only by a refractory wall and connected via
fluidized solids transfer ducts.
2 2
The gasifier section provides for 13.8 m flu1d1zed-bed area and 1.8 m
for the regenerator fluidized-bed area. The internal configuration of the
vessel is designed to provide a circulating flow of material through the bed
area. A central division wall is placed 1n the gasifier portion to help ac-
complish this. The design superficial velocities are 1.4 m/s for the gasifier
and 1.5 m/s for the regenerator.
The basic design fuel for the demonstration is a 2.67 percent sulfur
#6 residual oil. The design also provides for consideration of other normally
solid fuels, including coal.
The total estimated construction cost for the demonstration unit at San
.Benito, Texas, is: ,
Construction (including erection) $ 991,900
FWEC/CPL Contract (including equipment) 1,634,250
Engineering, 0/H (CPL) . 86.900
TOTAL . $2,713,050
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Advanced Low-Emission/Energy-Conserving Systems Strategies
EPA-VAN
The Laboratory's EPA-Van, a mobile research unit, is part of lERL-RTP's
program to control air pollution from homes, apartments, and small commercial
buildings. The pollution control technique used here is an energy supply
system containing environmentally clean and energy-saving components. The
EPA-Van's integrated system includes fuel cells, solar energy collectors, a
specially designed heat pump, and catalytic burners. This equipment is non-
polluting and is designed to optimize the energy-conserving features of each
of the components. The system provides all the energy needed for space heat-
ing, cooling, and ventilating; cooking; lighting; food refrigeration; water
heating; and appliances.
Engelhard Industries Division, under contract to IERL-RTP, designed and
built the Van. It was delivered to IERL-RTP early in 1976. The testing pro-
gram for the Van was scheduled to begin before the end of 1976.
Although the total impact of the EPA-Van power system will not be known
quantitatively until testing is completed, the environmental impact is felt
to be substantial because of the reduced fuel consumption resulting from use
of the coupled solar-energy/heat-pump system and the inherently nonpolluting
nature of fuel cells and catalytic burners. The unknowns at this point are
the environmental and economic impacts of the industrial equipment required
to produce, store, and transport the consumable fuel, and the economic impact
of the presently expensive fuel cells and catalytic combustors. The EPA-Van
is shown in the photo below.
ELECTRICAL ENERGY AND WASTE HEAT
An .IERL-RTP study (by Radian) has been completed to assess the degree to
which electricity from coal might be employed in the residential, commercial,
and industrial sectors as a supplement or substitute for clean premium fuels
such as natural gas, distillate oil, synthetic natural gas (SNG), or liquefied
coal. The electricity thus employed in these area sources would be completely
nonpolluting at the point of use, but would be generated in large central
power stations, burning coal and employing high-efficiency emission control
technology or low-polluting advanced combustion processes. The energy usage
efficiency and total environmental impacts (with emphasis on urban ambient
air) were evaluated for alternative methods for meeting user needs, together
with projections of changeover costs and rates. The oil and gas shortage and
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CTl
EPA-Van.
-------
the threat of a new embargo provide clear incentives for further examination
of the degree to which substitution of electricity (from coal-fired power
plants) for oil and gas usage in stationary endruse sectors can be implemented.
Electrical substitution does offer the potential for significant future re-
ductions in the amount of natural gas and distillate fuel oil consumed in the
residential, commercial, and industrial sectors. The report on this study was
published in the first quarter of 1976.
FUEL DISTRIBUTION PATTERN FLEXIBILITY
Battelle, funded by IERL-RTP, has completed a study designed to quantify
the amount of clean fuels (natural gas, distillate fuel oil, low-sulfur resi-
dential oil, and low-sulfur coal) which should be available through the year
2000 for switching to small sources from larger users as a means of area source
air pollution control. The report on this study was published early in 1976.
Under the study, an evaluation was made of factors affecting the ability
to switch fuels between users (e.g., equipment-related factors, business fac-
tors, fuel supply network factors), and the quantities of fuel affected by
each factor.
INDOOR AIR QUALITY
This project has been designed as an 18 month program of research, field
observation and analysis to produce new data on the occurrence, behavior and
significance of air pollution in nonwork places/indoor environments. The
project's broad objective is that of optimizing the energy conservation/air
quality/health relationships in indoor spaces through the identification of
causal relations and identification of feasible points of intervention. Pol-
lution sources, magnitudes of pollutants, and control techniques will be
identified and the importance of energy conservation measures will be assessed.
The first phase of the project includes the review and assessment of published
research and of on-going research efforts. The second phase includes a pro-
gram of indoor and outdoor air monitoring and determination of estimates of
indoor and outdoor air quality through mathematical models.
BASIC STUDIES/FBC POLLUTANT FORMATION MECHANISMS
No fully satisfactory explanation exists for the lower NO emissions ob-
tained at elevated pressures compared to those at atmospheric pressure in FBC
processes. These basic studies aim at developing: a mechanistic model for
predicting NO emissions, physical/chemical input parameters for the model, and
information leading to new control technology. The model will be tested over
a wide range of operating variables.
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Experimental work will be carried out on pilot-plant and pressurized
bench-scale combustbrs. The studies should (1) advance present understanding
of the mechanisms of formation and destruction of NO in FBC processes, and (2)
yield information on potentials for NO emission reduction.
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INDUSTRIAL PROCESSES
lERL-RTP's work in the area of industrial processes can be subdivided into
two distinct functional groupings: chemical processes and metallurgical proces-
ses. Because process measurements is applicable to the entire IERL-RTP pro-
gram it is treated as a separate major program. The following subsections of
this report discuss the first two groups separately.
CHEMICAL PROCESSES
IERL-RTP's Chemical Processes activities are presently grouped into six
categories:
0 Combustion sources
0 Petrochemicals
0 Refineries
0 Agricultural chemicals
0 Textiles
° Incineration at sea.
Additionally, IERL-RTP continues to be involved in review and other re-
sponsibilities for previously assigned functions during transition to other
IERL locations.
Source Assessment
In order to define control technology development needs for sources in the
six categories, information relating the characteristics of emissions to their
probable impact on receptors must be assessed. Presently, much of the infor-
mation required is nonexistent, or data reliability is uncertain.
A contractual effort was initiated in June 1974 to utilize the systems
approach to acquiring the source assessment data needed for decision-making,
regarding control technology development needs relating to air pollution as-
pects of specific sources.
Efforts to establish the order of performing detailed source characteriza-
tions have been completed. The sources were organized into the six categories
previously discussed. A model was then developed to estimate the relative en-
vironmental impact of each source within each category. Factors included in
the model were the pollutant type, the mass emissions, the atmospheric re-
activity or stability of the emissions, number of the source type, the growth
pattern for the industry, the location of the plants, population densities
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at the source locations, the relationship between source emissions and ambient
levels of the same type of pollutant at the location of the plant, and toxicity
of the emitted pollutants. Data from a wide variety of sources were used as
input to the model to calculate a relative environmental impact number. By
this means, a priority listing based on relative potential for adverse environ-
mental impact was developed for the sources in each of the six categories.
(While lERL-RTP's Source Assessment Program was initially structured to address
only the air pollution aspects of industrial sources, a change in orientation
was brought about by the 1975 reorganization of ORD. Efforts are currently in
progress to structure the program to address pollution of all media.)
\
The original program, which addressed only air pollution, did result in
prioritization listings for sources based on the potential for adverse environ-
mental impact from air pollutants. From these listings of source priorities
for each category, sources were selected for which initial prototype Source
Assessment Documents (SADs) are now being developed. These SADs will consider
the aforementioned factors in detail and present all information necessary to
allow decisions to be made by IERL-RTP personnel as to control development
needs for the source types under consideration.
The SADs now under preparation or completed are:
Combustion Sources
Pulverized Bituminous Coal-Firing Dry-Bottom Utility Boilers
Industrial External Combustion Using Pulverized Bituminous
Coal in Dry-Bottom Boilers, Furnaces, etc.
Coal-Fired Residential Furnaces
Petrochemicals
Acrylonitrile
Solvent Evaporation—Surface Coating
Chlorinated Hydrocarbons
Phthalic Anhydride Production
Carbon Black
Acetone and Phenol from Cumene
Agricultural Chemicals
Fertilizer Mixing Plants
Ammonium Nitrate
Synthetic Ammonia Production
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Agricultural Chemicals (con.)
Phosphate Fertilizer Industry
Urea Manufacture
Chlorinated Phenolic Pesticides
Toxaphene Manufacture
Textiles
Cotton and Synthetic Textile Finishing Plants
Effluents from each source will be identified and characterized in terms
of individual pollutant emission rates (i.e., source strength), potential for
adverse health effects, and environmental stability of pollutants. Ambient
pollutant levels will be estimated for typical sources by means of accepted
dispersion equations. The source distribution will be presented and related
to affected population. Studies of the availability and performance of viable
control technology will be presented.
In addition to the assessment program described above, two new major
assessment programs have been initiated: for conventional combustion systems
and for petroleum refineries. Both are described below in their appropriate
sections, along with control technology progams which are underway to the
same source category.
Combustion Sources
CONVENTIONAL COMBUSTION SYSTEMS-EMISSIONS ASSESSMENT
Assessment and definition of the problem of emissions from combustion
sources is a major concern to IERL-RTP. In addition to the Source Assessment
Documents (SADs) being prepared for combustion sources by Monsanto Research
Corp. (MRC), other approaches to assessment of conventional combustion sources
have been employed. Operation of conventional combustion systems (i.e., those
which currently use common fossil fuels such as coal, oil, natural gas, and
agricultural, forestry, or other wastes for electrical power generation or
space heating) causes continuous and intermittent vapor/liquid/solid dis-
charges to the air, water, and land from a number of associated processes in-
cluding: fly ash/bottom ash/bottom ash sluicing, water treatment, flash tank,
scrubber sludge, stack, fuel storage, mud-drum Slowdown^ and fireside cleaning,
Previous and on-going data collection programs are directed toward emission
assessment related to~these discharges. ~
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Environmental and emission assessments of conventional systems were pre-
pared for IERL-RTP by 6CA Corp. and published in March 1976. (This was inde-
pendent of the MRC program discussed earlier.) The overall objective of this
project was to prepare a preliminary emission assessment of conventional sia-
tionary combustion sources (those currently in use and based on common fossil
fuels—coal, oil, natural gas--or solid wastes such as those derived from
agricultural, forestry, or municipal refuse).
The GCA report gives results of an emissions assessment of the air,
water, and solid waste pollutants produced by conventional stationary combus-
tion systems. It gives results in four principal categories: utilities
(electric generation), industrial (steam generation, space heating, and sta-
tionary engines), commercial/institutional (space heating and stationary
engines), and residential (space heating). For each principal combustion
system category, it defines: process types and operating efficiencies, fuel
consumption, pollutant sources and characteristics, major research and develop-
ment trends, fuel consumption trends, and areas where emission data are in-
complete or unreliable. It also gives the pollutant emissions from applicable
unit operations for each of 56 source classifications, using a uniform com-
bustion source classification system, and identifies major gaps in available
data regarding the population and capacity of combustion systems, application
of control measures, fuel composition, and other parameters which signifi-
cantly influence pollutant characteristics and emission rates.
A supplementary report issued in August 1976 identifies and discusses
major recent on-going and proposed programs 1n the area of pollutant emissions
from combustion sources. The in.ormation covers the period from December 1975
to June 1976 and was obtained through a review of the literature and contact
with governmental and industrial representatives.
Other work on emission assessment of conventional combustion systems was
initiated by TRW in September 1976. This study will assess air and water pol-
lutants, including those generated from solid waste disposal, from 54 combus-
tion categories, including (1) residential, commercial/institutional and in-
dustrial sources from combustion of coal, oil, gas, wood, and lignite, and (2)
electricity generation sources.
This program will (1) define criteria for determining adequacy of exist-
ing emissions assessment data, including a quantitative basis for decision-
making relating to items such as error analysis, data reliability, pollutant
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levels, pollutants considered, and techniques for criteria application, (2)
identify those categories or portions of categories that have been adequately
assessed on these criteria, (3) identify those categories that will require
additional investigation, (4) develop a program to complete the emissions
assessment, and (5) complete the emissions assessment. The assessment will
include mass balances for each category and will include the following air
pollutants: trace elements, CO, SOX, NOX, S04, POM, PCB, hydrocarbons, and
particulate by size fraction. Characteristics of each category for water
pollutants such as pH, alkalinity, hardness, and conductivity will be included.
ELECTRIC POWER GENERATION
Earlter discussion has described assessment of the many types of com-
bustion sources. The following discussion relates to programs which involve
combustion only from the standpoint of electric power generation.
Increasing attention is being directed toward obtaining information
on the contribution of power plants to the atmospheric loading of
"toxicitrace elements and toward development of better means to control
their emission." Previous studies have succeeded ~in~ providing some •
knowledge of the distribution of trace elements in the flue gas,
and the distribution of these elements in various fractions con-
tained in the fly ash particles. Results of earlier work are considered
Inconclusive and fates of trace efements are still nofknown primarily because
of the lack of adequate sample collection techniques. Less information is
available on vapor-phase trace elements than is known for the particulate phase.
In view of the potential hazards of toxic trace elements that may be released
from fossil-fuel combustion and the need to improve vapor and fine particulate
control technology, TVA has initiated a research program to quantify and
characterize such combustion products from its coal-fired power plants. The
objectives of this program are to gather, analyze, and interpret data on com-
bustion products from coal-fired utility boilers in order to gain a better
understanding and provide a basis for the improvement of control technology for
fine particulates and vapor-phase trace elements. This is being achieved by
chemically and physically characterizing vapor-phase trace elements and fine
particulates in the flue gas and by relating formation of these "compounds and
their characteristics to boiler operations and control device performance.
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INDUSTRIAL BOILERS
Field testing of trace element and organic emissions from industrial
boilers was performed by KVB, Inc., and a report was issued in December 1976.
Sampling of four coal-fired industrial boilers was conducted to determine
emissions of 19 trace and minor elements and polycyclic organic matter (POM).
Emissions of the trace and minor elements were related to total quantities of
each element present in the fuel by examining the degree of mass balance and
element partitioning based on fuel input and element output in furnace de-
posits, fly ash, and flue gas vapor. The tendency of finer particulates to be
enriched in volatile elements was established by chemical analysis of cas-
cade impactor fractions. Total measured output of elements classified as
high in volatility tended to be less than the fuel input. This was attributed
to possible low collection efficiency of sampling equipment for vapor-phase
elements. These same elements were found to be more highly concentrated in
the fly ash as opposed to furnace deposits and to have higher concentrations in
the smaller particle sizes. Elements classed as medium or low volatility
tended to be more uniformly distributed with respect to both Tbca'tfoh" in
the boiler and particTe~sfze7 Total mass outputs for these elements
frequently exceeded coal'inputs'"indicating possible sample contamination
by boiler or sampling system construction materials. The presence of four
specific POM compounds was indicated in the coal, ashes, and stack gases but
results were highly variable.
Petrochemicals
Petrochemical processing includes all industrial processes that use pe-
troleum as a feedstock. Because of the size and importance of the oil and
petrofuel industries, oil refineries are discussed separately later. Con-
sidered here are special multimedia pollution problems from nonfuel uses of
petrochemicals.
ETHYLENE DICHLORIDE (EDC) PROCESSES
Hydrocarbon emissions are the major pollution problems associated with the
manufacture of EDC: the ethylene oxyhydrochlorination absorber vent is the
main source of these hydrocarbon emissions. Current processes employ air as
the oxygen source and vent the resultant inert gases, along with about 0.03
tons of hydrocarbon per ton of EDC produced, to the atmosphere. EDC production
is now about 5 billion pounds per year. \
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At the start of this project there was no practical way to eliminate the
oxyhydrochlorination vent from existing processes; the gases are too dilute
for incineration, and the addition of natural gas to make the gases combustible
is an extravagance. Furthermore, incineration would form hydrochloric acid
which would have to be controlled by scrubbing.
The objective of a project conducted by Allied Chemical Corp. was to
demonstrate that emissions can be reduced by at least 90 percent from the
levels encountered with typical existing processes. The modified process em-
ploys recycling of reactor exit gas, oxygen feed, and whatever additional
processing steps are determined to be necessary to control build-up of by-
products in the recycle stream. The modified process was intended to be
economically competitive with present day processes. The process performance
was evaluated on a pilot scale so that a preliminary study of technical and
economic feasibility could be carried out.
The pilot work is now complete and the findings were presented to in-
dustry. Industry has completed similar or equivalent work'. Further proposals
were not received and work on this process has been discontinued.
VINYL CHLORIDE (VC)
An activity carried out during 1975 was a sampling of the interiors
of seven different models of new U.S. automobiles in order to measure VC con-
centrations and detect the presence of other hazardous organic vapors: all
cars had less than 1.2 ppm VC in the air, and no other problem vapors were
detected. The final report of this sampling, carried out by Monsanto Research,
was issued in May 1976.
POLYCHLORINATED BIPHENYLS (PCBs)
This effort makes use of the special expertise and equipment available
at Envirogenics Systems Company to extend the application of a metal/metal
couple reduction process to the treatment of the EPA "toxic/hazardous"
material, PCB. The process system is a reductive chlorination process employ-
ing an iron powder doped with copper catalysts dispersed within a sand matrix.
By stripping chlorine from compounds the process has the potential to produce
less toxic and more readily biodegradable compounds. The work included
laboratory-scale and bench-scale optimization (6 inch diameter, 1 to 3 gallons
per minute). In laboratory tests the process was capable of reducing concen-
trations of PCBs in wastewater down below 1 part per billion. Studies have
shown that with the reductive degradation process, 84 percent of the total
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chlorine going in with the PCBs is converted to inorganic chloride. Fate of
the remaining chlorine is unknown, and it is possible that some remains in
hard-to-characterize, potentially toxic forms.
A cooperative program with EPA's Gulf Breeze Laboratory is in progress to
define the toxicity of the residual, organically bound chlorine compounds to
marine organisms. Other efforts are currently in progress to close the mate-
rial balance for the technology and to identify and quantify all reaction
products. The process is intended to be applicable to the treatment of PCBs in:
(1) PCB manufacturing effluent; (2) PCB user effluent (e.g., electric trans-
former and condenser manufacture); and (3) treatment of accidental discharges
and leachates from areas where PCB-containing equipment has been dumped, is
being stored, or is being operated. The process also has the potential for
application to drinking water supplies.
In addition to the above PCB work, the reduction process will be screened
for its effectiveness in treating various light-end chloroearbons often found
industrially with PCBs; e.g., ethylene di- and tri-chlorides, carbon tetra-
chloride, and chloroform. The feasibility project is scheduled for completion
in March 1978.
A demonstration grant on this process is in progress, with operational
testing to start in April 1977. General Electric Co. and EPA have entered in-
to a cost-sharing agreement to conduct full-scale tests at GE's capacitor
manufacturing plant in New York State.
Environmental acceptability of wastewaters treated by this process will
be evaluated by the Gulf Breeze Effluent Biotesting Program (EPA-Gulf Breeze/
Bionomics). Acute and chronic trxicity tests involving fresh water and marine
biota are underway, as well as bioaccumulation studies.
CHLOROLYSIS
A promising new technology is being developed by Repro Chemical Corp. and
Hoechst-Uhde, Frankfurt, Germany, which involves use of high-temperature/high-
pressure chlorination of chemical manufacturing waste. Assessment of such
parameters as the magnitude of potentially available U.S. organic wastes suit-
able for chlorolysis feedstock and markets for chlorolysis conversion products
(carbon tetrachloride, carbonyl chloride, and anhydrous hydrochloric acid) will
determine the most practical chlorolysis process. Repro has surveyed the availa-
bility in the U.S. of pesticide wastes suitable for chlorolysis conversion.
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Tests have shown that vinyl chloride, chlorinated solvents, vinylidene
chloride, and other residues are readily chlorolyzed to carbon tetrachloride and
hydrogen chloride; however, these residues must be relatively free of
sulfur to avoid reactor corrosion. Investigations now underway by Hoechst-
Uhde, with a subcontract to Repro Chemical, will include engineering design
and economic feasibility of a regional integrated chlorocarbon disposal
facility, based on previous EPA-supported bench-scale studies of chlorolysis
of defoliants. The design capacity will be 25,000 metric tons per year of
chlorocarbon wastes. This design should be ready during the first half of 1977.
Refineries,
SOURCE ASSESSMENT—AIR POLLUTION
Petroleum refineries consist of a complex of physical and chemical trans-
formation operations. While most of the individual point sources of emissions
within the refinery have been identified, fugitive sources may be the principal
emitters of hydrocarbons. In order to identify those refinery operations re-
quiring air, solid, or water effluent control, IERL-RTP is now carrying out a
detailed assessment of the environmental effluents associated with oil refin-
ing. The study will quantify the potential for emissions in each step of the
physical and chemical transformation of petroleum. Particular emphasis will be
placed on "fugitive" emissions. Operations which are expected to utilize
heavier feedstocks will also be emphasized. Plants selected for sampling will
be typical in terms of present control technology utilized. The field sampling
program will quantify emissions. This data will be of adequate quality to
support a guideline document for determining the environmental impact of ex-
isting and new petroleum refineries.
From this assessment and guideline document, the major control program
emphasis of future years will be defined. On-going investigations are described
in the remainder of this section.
TECHNOLOGY ALTERNATIVES: REFINERY SOX CONTROL
Petroleum refineries are a major industrial emitter of sulfur oxides (SO ).
/\
In 1969 the estimated SO emissions from 262 refineries (charging 12 million
/\
barrels of crude petroleum per calendar day) were 2.2 million tons. Moreover,
the petroleum refining industry growth rate is projected to be 3 to 4 percent :
annually. As refineries process more higher-sulfur crudes, the need to control
SOY emissions from petroleum refineries continues to grow. IERL-RTP is, there-
/\
fore, vigorously seeking methods for suppressing SOV emissions from petroleum
/\
refining operations.
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Four approaches to SOV control currently exist for petroleum refineries:
A
desulfurization of flue gases, desulfurization of in-process feedstocks, de-
sulfurization of the whole crude feedstock, and combinations of the above.
The technology required for each approach has been developed to different
levels. Since pollution control technology has developed rapidly, an up-to-
date analysis of techniques applicable to petroleum refineries, the associated
economic impact on petroleum products, and areas of inadequate technology need
to be reviewed. IERL-RTP, with the assistance of the American Petroleum In-
stitute, conducted a program to quantify the impact of the alternative ap-
proaches, based on up-to-date technology and economics.
. This program, performed by Arthur D. Little, Inc., assessed the impact on
the U.S. petroleum refining industry of a possible EPA regulation limiting the
level of gaseous refinery sulfur oxide (SO ) emissions. Computer models repre-
/\
senting specific refineries in six geographical regions of the U.S. were
developed as the basis for determining the impact on the existing refining in-
dustry. New refinery construction during the period under analysis (1975-
1985) was also considered by development of computer models representing new
refineries. Control of refinery SOY emissions from both existing and new
/\
refineries was defined for the purposes of this study by maximum sulfur levels
of refinery fuel and of fluid catalytic cracking unit feedstock and by increased
sulfur recovery in the Claus plant. The computer models thus constrained
were utilized to assess investment and energy requirements to meet the possible
regulation and the incremental cost to manufacture all refinery products as
a result of the regulation. Parametric studies evaluated the impact of varia-
tions in the types of imported crude oils available for future domestic re-
fining and the projected sulfur level of residual fuel oil manufactured in the
U.S. Reports on this project were issued in 1976.
AUTOMOBILE FILLING STATION CONTROL
This study, being conducted by Scott Environmental Technology, Inc., was
initiated late in 1975 in response to a request from EPA's Office of Air
Quality Planning and Standards. It is aimed at determining the variables
affecting the working capacity of the charcoal beds used to control gasoline
vapors in service stations. Any decrease in charcoal bed working capacity will
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be identified. The first phase of this project has been completed and a report
is expected in early 1977. An extension of this work will evaluate the eco-
nomics and the range of data.
Agricultural Chemicals
Pollution problems arising from the production of agricultural chemicals
involve both air and water pollutants. They are associated with the produc-
tion of fertilizers and pesticides.
FERTILIZERS
Studies of effluent cleanup from fertilizer production were assumed by
IERL-RTP during 1975. Many of these programs were originated by EPA's Athens
(Ga.) Laboratory. One project is currently in progress with Farmers Chemical
Assoc., Inc. and is jointly funded by them.
The objectives of this project were to: evaluate all conventional and
several experimental methods for inorganic nitrogen removal from water, deter-
mine the optimum process(es), and demonstrate at full scale on wastewater
from a balanced-N fertilizer production complex (i.e., one containing ammonia,
urea, nitric acid, and ammonium nitrate units). In the demonstration model,
high ammonia concentrations were reduced by air stripping. Oxidation of
residual ammonia to nitrate was accomplished by bacteria in the trickling
filter. Denitrification of nitrates was accomplished by anaerobic lagoons using
methanol or another waste stream as a carbon source. The feasibility of waste
stream segregation, recycle of concentrated streams, and internal use of
dilute streams was also to be established. Advanced physico-chemical processes
(such as ion exchange, reverse osmosis, electrodialysis, and mixed-salt pre-
cipitation) were evaluated. Ion exchange (IX) proved to be the only feasible
method. Double loop, continuous IX beds were designed and installed by Chem-
Seps in 1972. Total water reuse was achieved for 1 month (July 1974).
Ammonia and nitrate were recovered and recycled as product. Economic data
analysis and evaluation of the system are still underway. The complete air/
water impact of the system is still to be determined.
A related project is being conducted by the Institute for Technology
of Nuclear and Other Mineral Raw Materials, Belgrade, Yugoslavia, at the FMK,
Novi Sad Plant site. Directed toward evaluating air and water pollution
potential and abatement in granular fertilizer plants, this project will:
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0 Characterize air and water waste effluents generated in a typical
N-P-K granular fertilizer plant operating in the non-recycle water mode.
Both the quantity and composition of major sources will be correlated
with plant production rate, product mix, and raw"material variations.
Primary pollutants of interest are (1)^Tr--paytTculTfei,"hydr6geFfluoride,
fluoride, ammonia, and ammonium salt fines (e.g., ammonium chloride and
sulphate), and (2) water—ammonia, fluoride, and ohosphate.
Construct and verify first-generation air transport and dispersion
model(s) specifically for application to granular fertilizer plant emis-
sions—gases (fumes) and particulates. All models tested will be cali-
brated with local meteorological and pollutant concentration profile data.
The basic model development in this task is to create a generalized
plant operating-downwind dispersion model for granulation plants.
0 The quantification and characterization of Task I will be repeated
following installation of more advanced dust emission control equipment.
Using the Rotoclone, performance will be established under a variety of
operating conditions; e.g., products and production rates, and its
economics delineated.
0 Models developed will be reverified by comparison of calculated and
measured downwind pollutant profiles at the lower emission rates expected
after Rotoclone installation.
0 Models in combination with plant waste source data will be used to
conduct cost-benefit ratio calculations for various treatment options
should additional control be needed. Based upon these evaluations, the
plant waste source inventory d^ta, and the technology literature, a plan
of recommended, cost-effective abatement or operating techniques for
minimizing pollutant discharges from each source will be presented to the
plant management as the final task output.
A study to develop treatment of ammonia plant process condensate effluent
is being conducted by Gulf South Research Institute for IERL-RTP. To date pro-
gram activities have been concentrated on plant sampling and test programs, as
well as economic evaluations of process schemes to reduce ammonia in the plant
process condensate. These schemes include atmospheric-pressure steam-stripping
for process condensate; reinjection of steam-stnpped process condensate into
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primary reformers; adsorption of ammonia on vanadium pentoxide (a catalyst),
to produce aqueous ammonia (28 percent) and/or anhydrous ammonia by-product
upon regeneration of the catalyst; and addition of phosphates and potassium
magnesium sulfate to the process condensate stream to produce a marketable by-
product of magnesium ammonium phosphate fertilizer.
Atmospheric steam-stripping, a process that utilizes live steam as the
driving force to strip out the ammonia in the condensate effluent via a
packed column, has been shown to have the following advantages:
0 Least expensive of all processes to operate.
0 Simplest process scheme requiring least supervision.
0 Small amount of process land area needed.
Further work will be concentrated on this process.
PESTICIDES
In a project jointly funded with Velsicol Chemical, IERL-RTP is currently
developing, demonstrating, and evaluating two processes for nonbrine chloro-
carbon pesticide wastewater. Demonstration tests involve heptachlor and
endrin wastewater effluent from Velsi col's Memphis, Tennessee, plant. Proc-
esses of choice are resin adsorption removal and catalytic reduction (de-
chlorination).
In experiments begun in December 1976, Rohm and Haas XAD-4
._ _ ,•>
resins were used to remove heavy-encT'chTbrocarBbns" from the waste-
water, ft "is estimated that "solvent" (isopropyl alcohol)" regeneration
of the resin will permit a closed loop sysYei^wTthTeuse^of" resTn
and solvent.
Metal reduction focuses on the use of copper-catalyzed iron powder to
dechlorinate/dehydrochlorinate the light and heavy components alike. This
reduces waste toxicity as well as increasing the biodegradability of the
waste. Although either process alone should treat effluent to acceptable
levels, tandem tests, with the resin and catalytic reduction steps in series,
will also be investigated. The test runs and final report are scheduled for
completion by early 1978.
Extension of catalytic reduction technology to other pesticide manufactur-
ing waste applications is being studied at the laboratory-scale by Envirogenics.
Catalytic reduction technology, including not only iron/copper, but also other
metal couples, has potential for treating other toxic substances such as
Kepone, aldrin, dieldrin mirex, endrin, toxaphene lindane, heptachlor, DDT
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and its metabolites, 2B4-D and 2,4,5-T. Screening studies will be done to
establish its feasibility to detoxify and chemically degrade atrazine, toxa-
phene, Kepone, mirex, and other chlorinated hydrocarbons.
Bench-scale tests will be conducted for some of these chemicals in order
to optimize the system, establish operating experience, and obtain data for
scale-up. Finally, a comprehensive economic analysis will be done to compare
cost of reduction technology to other alternatives such as carbon sorption.
This work is scheduled for completion in March 1978.
Another pesticide problem under investigation is treatment of DDT manu-
facturing waste effluents. Envirogenics Systems Company is developing a
solvent extraction process to remove DDT from waste that is currently being
landfilled. The only domestic manufacturer is Montrose Chemical. A demon-
stration grant was awarded to Montrose Chemical, enabling their DDT plant at
El Monte, California, to be used by Envirogenics to apply the technology to a
DDT waste stream. DDT wastewater streams characteristically are of large
volume and have high salt content, high suspended solids content, high
viscosity, and undesirable levels of DDT. Heptane and monochlorobenzene have
been tested as solvents for extraction of DDT and homologs. Since monochloro-
benzene is a reactant chemical for making DDT, the organic phase from extraction
can be fed into the head-end of the DDT plant. For this reason, monochloro-
benzene is the preferred solvent. A final report on the project is expected
in early 1977.
A third major pesticide program, being studied by Hoechst-Uhde, is the
conversion of chlorocarbon and pesticide wastes by complete or partial
chlorolysis. The technical feasibility of the process has been demonstrated;
the major question now is one of economic feasibility. The current work has
been described under Petrochemicals, above.
In other activities, an extensive overview document on pesticides was
completed by the Midwest Research Institute. This document serves as input
to the MRC source assessment program and as an internal management decision
tool.
Textiles
Textile manufacturing processes generate voluminous wastewaters which are
environmental polluters if not treated. If wastewaters can be reused, there
is considerable potential for lower manufacturing costs. A number of projects,
162
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either totally or partially funded by IERL-RTP, are now underway which have
pollution reduction from textile processes or wastes as one of their goals or
their major goal.
ATMI STUDY
EPA is aiding ATMI (American Textile Manufacturers Institute) in a 30-month
court-ordered study to evaluate the treatment efficiency of technological
processes, defined by EPA as BATEA (Best Available Technology Economically
Available) for the textile industry and to evaluate the economic achievability
and impact on the industry resulting from the application of these technologies.
The work is being performed by technical and economic consultants under the
joint direction of ATMI and EPA. The actual investigations will be carried
out through the use of two mobile pilot treatment units. Approximately 24
plants will be investigated. These 24 plants will be selected from among
plants already achieving the Effluent Guidelines Division's Best Practical
Control Technology Currently Available (BPCTCA) level. The treatment processes
will include physical/chemical treatment (chemical coagulation, multimedia fil-
tration, granular carbon adsorption, powdered activated carbon, dissolved air
flotation, and ozonation). The economic study is-being conducted by a mutually
agreed upon consultant. He will evaluate the data collected in the pilot
treatment study, and project the economic impact of the 1983 guidelines nn
the textile industry as a whole.
In connection with the ATMI study, an investigation is being started to
determine toxicity of textile effluents from secondary treatment plants. The
ability of the six treatment technologies to reduce toxicity will be tested.
The toxicity of waste streams will be established, using biotesting screening
techniques. It is anticipated that this project will involve cooperation
between several EPA organizations: IERL-RTP, Effluent Guidelines Division,
and two or three "water" laboratories.
OTHER PROJECTS
Holliston Mills, Inc., in Kingsport, Tennessee, has been investigating, on
a pilot scale, the treatment of cotton textile waste by enzymes and a high-rate
trickling filter. A report is expected in mid-1977.
In a novel approach based on a process modification, Auburn University is
evaluating the impact of the use of solvent-based sizing techniques on textile
plant effluent parameters. The project includes economic and technical eval-
uations. The project is nearly complete and a report is expected in mid-1977.
163
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In another project, over the next several years, Auburn plans to: (1)
analyze and characterize potentially useful solvent warp sizing polymers, (2)
determine the physical/chemical effects of solvent substitution on fibers, (3)
evaluate their effect on actual weaving performance, (4) evaluate the economic
impact and potential of solvent technology in warp sizing, (5) evaluate the
energy implications of solvent process substitution, (6) evaluate the effect
of solvent slashing and desizing on process water discharge quality and quantity,
and (7) evaluate the effect of solvent substitution on air pollution and
ambient air quality. An additional project with Auburn is being funded to in-
vestigate the use of aqueous solutions of sizing agenvs that can be recovered
by thermal precipitation. This project is directed toward eliminating the air
pollution problem encountered with use of other solvents.
Owens-Corning Fiberglas in Toledo is demonstrating, first in pilot-scale
and then in full-scale plants, the complete recirculation and reuse of a com-
plex industrial wastewater from a fiberglass textile manufacturing plant. The
reclaimed wastewater will be used for nonprocess; uses such as washdown, chain
scrubbing, and cooling. Accomplishing this objective of total reuse requires:
(1) establishing water quality criteria for inplant water uses, (2) additional
local water conditioning and recycle facilities for cooling, scrubbing, and
chain washing, and (3) improved wastewater treatment so that remaining waste-
water may be reused for nonprocess uses. The pilot phase of this study is com-
plete and a report will be published in mid-1977. Owens-Corning, based on
this work, will build a full-scale plant, the design of which is partially
funded by EPA.
LaFrance Industries in LaFr-nce, South Carolina, is assessing the technical
feasibility of producing a reusable effluent from textile wastewaters by apply-
ing hyperfiltration. The objective of this project is to demonstrate pilot-
plant reverse osmosis, possibly in connection with ultra-filtration, for treat-
ment of dye house wastewaters followed by reuse of the water, with attendant
energy savings. Cellulose acetate and dynamic membrane systems are being
evaluated for the separation of dissolved solids and color concentrates. En-
gineering and economic analyses are being performed for all aspects of the
project, including water reuse in standard dyeing processes.
J. P. Stevens & Co. in Greensboro, North Carolina, is evaluating treatment
sequences for cleaning textile wastes including biological treatment, multimedia
filtration, and activated carbon/ion exchange. A key feature of the research
164
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is the demonstration of reuse of the completely treated water in dyeing tests.
The biological and multimedia filtration units are full scale; the activated
carbon/ion exchange units are pilot scale; and the reuse investigations are on
laboratory scale. The project is nearly complete and a report is expected in
mid-1977.
Beaunit Fibers Corporation is biologically treating nylon 6,6 wastewaters
using oxygen enriched off-gases (40 percent available oxygen) from the nylon
manufacturing process. The oxygen aerated activated sludge system is monitored
to determine raw waste characteristics, process kinetics, and economic data.
This unique system demonstrates treatment of nylon wastewater and utilization
of by-products to achieve pollution abatement. The project is nearly complete
and a report is expected in mid-1977.
Bennett College, in Greensboro, North Carolina, is evaluating the ion
exchange process for treating textile dyeing wastewater. This pilot-scale
demonstration assesses dye reuse and makes cost projections for a full-scale
plant; The project is nearing completion and a report is expected in mid-1977.
ENVIRONMENTAL ASSESSMENT-AIR POLLUTION SOURCES
Air effort is being made to characterize the air pollution aspects
of the AmericarTtextile industry, including emissions from surface
finishing operations such as dyeing and sizing. Monsanto has com-
pleted major portions of the preliminary source assessment document. Also in
conjunction with this, Monsanto has completed a document "Preliminary Overview
and Prioritization of Sources of Air Pollution in Textiles Manufacturing."
This document presents impact factors for all major unit operations in textile
manufacturing and provides the basis for making choices for further source
characterization by source sampling and analysis.
Incineration at Sea .
The major goal of the Incineration at Sea program is to establish
minimum requirements and operating criteria to ensure that this waste
disposal method is conducted in an environmentally acceptable manner.
Monitoring, sampling, and analysis plans were developed for shipboard
incineration of organochloride wastes. Considered were: (1) a description
of incinerator ships, their incineration operation, and interface require-
ments necessary for obtaining samples; (2) design of sampling probe and
mount, and the sampling procedure; (3) approach for on-line monitoring of
combustion gases; (4) acquisition of combustion products; (5) testing work
areas to ensure safety during tests; and (6) general analytical planjFor all
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the samples taken during waste destruction tests and of the wastes to- be destroyed,
Two at-sea incinerations were observed by an EPA contractor. One "burn" was
monitored by the French Government: its results were reviewed with EPA and served
as additional input to our data gathering program. During 1977, EPA expects to
conduct full scale monitoring on two different incinerator ships, results of which
will be used to develop Federal regulations for the control of incineration at sea.
Miscellaneous Projects
FLARE SYSTEMS
Flaring, while a relatively cheap method for disposing of certain indus-
trial waste gases, may create significant quantities of air pollutants. In a
study completed in mid-1975, the number of flares operating in the petroleum,
chemical, and metallurgical industries was estimated along with the amount of
material flared. Design parameters for flare systems were reviewed to orovide
the background to establish the base on which additional work can be built in
order to make flaring an economical and environmentally sound method of waste
gas control. The report, issued in early 1976, includes an evaluation of pres-
ent engineering technology and of existing flare systems, assessment of present
practices and problems, determination of major sources, and development of
research recommendations including potential applications. It summarizes emis-
sions data, and gives emission factors for hydrocarbon waste streams, based on
limited available data. It recommends the selection of applicable flare sys-
tems and components for flaring given waste streams and discusses potential
problems which may affect design and component selection. Cost guidelines based
on discussions with flare vendors and users are given.
VEGETATIVE STABILIZATION OF MINERAL WASTE HEAPS
This project, conducted at vhe Research Triangle Institute, consisted of
an evaluation of the use of vegetation as a method for controlling fugitive
dust emissions from man-made mineral waste heaps. Mineral waste piles exist
primarily because of mining and milling operations. They are found in every
state. In dry windy climates, such as those of the Great Plains and Rocky
Mountains of the United States, they constitute a significant source of fugi-
tive dust emissions. While on a national scale fugitive dust emissions from
mineral waste piles are not the dominant source of fugitive dust emissions
(dirt roads, agricultural activities, and construction sites emit more fugitive
dust), they often dominate the air quality in their immediate vicinity. In
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addition, the toxic character of a specific mineral waste, such as asbestos,
can make control imperative even though the mass emissions alone are not
exceptionally high.
Much revegetation research has been carried out in recent years and the
bulk of the study reviewed this work in a pseudo case history format from which
general guidelines and recommended methodologies for carrying out the revegeta-
tion of mineral waste piles were deduced.
The report on this project was issued in April 1976.
The study concluded that:
0 Vegetative cover has been very successful in stabilizing many mineral
wastes and is preferred, when practical.
0 Revegetation of mineral wastes is sufficiently complex that no sure-fire
procedure can be specified as to optimum procedures for any given waste
in a specific area. :
° Virtually any mineral waste pile can be stabilized with vegetation,
given enough time and resources; the problem is knowing when it is
economically reasonable to proceed with a vegetative control method.
0 Little quantitative data exist by which to measure the magnitude of the
fugitive dust emitted by mineral waste piles or to assess the improve-
ment in air quality resulting from vegetative stabilization.
EQUILIBRIUM PARTIAL PRESSURE IN ALKALINE SCRUBBERS
A report on an inhouse study on equilibrium partial pressure of sulfur
dioxide in alkaline scrubbing processes was released in December 1976. The
study, performed on NaOH/KOH systems and citrate systems, produced data which
invalidated Johnstone's equations and which provided the basis for a better
understanding of the thermodynamic limitations of scrubbing efficiencies.
ODOR ABATEMENT FOR RENDERING INDUSTRY
The problem addressed by IERL-RTP in the rendering industry was control of
odors. In a program jointly funded with the Fats and Protein Research Founda-
tion, the Illinois Institute of Technical Research Institute, (IITRI) designed
and evaluated wet scrubber systems for effective removal of rendering odors
from plant ventilating air and process air. Scrubber oerformance was measured
by both odor panel and gas chromatographic analysis. Experiments in a three-
: stage packed-bed laboratory-scale scrubber at the rendering plant evaluated
solutions of sodium hydroxide and the strong oxidants sodium hypochlorite,
hydrogen peroxide, and potassium permanganate. Since removal of 90 percent per
stage was obtained with fresh alkaline sodium hypochlorite solution, this
reagent was selected for subsequent longer-term tests. A 2 week test of a
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plant-scale horizontal spray'scrubber, operating on plant ventilating air,
showed odor removal of 83 percent. The outlet odor units averaged 64; the in-
let ranged from 165 to 2500 odor units. A three-stage packed-bed scrubber was
evaluated to replace an existing incinerator being used to treat a process air
stream that contained from 5000 to 50,000 odor units. A week-long test with
the scrubber gave a lower-than-expected average odor reduction of 85 percent.
Data were obtained on chemicals consumption and effect of flow variables on
odor removal, and used to update computer models that can be used to design
scrubbers for odor removal.
This project has been completed and an EPA report was issued in January
1976.
GUIDELINES FOR ENVIRONMENTAL ASSESSMENT OF ENERGY SYSTEMS
To standardize preparation of environmental assessment documents in the
general field of energy systems, GCA Corporation, under IERL-RTP contract,
prepared a guideline document which was published in March 1976. The report:
(1) defines environmental assessment (EA) programs and their role in energy
system development; (2) indicates data requirements of an EA; (3) outlines
exemplary methodologies for acquiring the necessary data; (4) serves as a tech-
nology transfer vehicle by providing background information on environmental
monitoring and modeling, which can be used in EAs; (5) summarizes the extent,
quality, applications, and location of existing information resources which
can be used in the planning of EAsi and (6) summarizes existing or proposed
standards and criteria for evaluating air-, water-, and land-based pollution.
It includes: waste stream characterization and pollution identification; in-
direct pollution associated with energy system development; estimating the
sphere of influence of an energy system; evaluation of environmental impact;
methodology for conducting source tests; use of dispersion models; available
data banks and information sources; and existing and proposed environmental
regulations. Each topic is explored to the degree necessary to acquaint the
user with current standards, sampling and analytical techniques, and environ-
mental models. General discussions are supplemented where possible with
specific examples in order to clarify some of the concepts presented.
METALLURGICAL PROCESSES
The major reorganization of EPA's Office of Research and Development re-
sulted in the divestment of nonferrous metallurgical air pollution programs
and the acquisition of ferrous metallurgical water and solid programs by IERL-
RTP. The ferrous metallurgical industry consists of the iron and steel,
ferroalloy, and iron and steel foundry segments.
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Iron and Steel Industry
The iron and steel industry converts iron ore and scrap iron into useful
iron and steel oroducts (see following illustrations). At large integrated
steel plants, iron-bearing material (lump iron ore, sinter, or pellets),
limestone, and coke are charged to a blast furnace where the iron ore is
reduced to molten metal which is periodically tapped. The iron from the
blast furnace is saturated with dissolved carbon which must be removed to
change the iron into steel. The iron from the blast furnace, usually molten,
is generally mixed with cold scrap in a steelmaking furnace & where the
carbon is reduced"to"The requiredlevel, impuriti"es "a"re""rOT6ved, and alloying
agents are added".""'In the~basTc oxygerTsteel process, the mixture is blown with
oxygen~toToxidize the carbon and other impurities.(Other, less important,
steelmaking processes are the open-hearth and electric arc.) The steel from
the furnace is poured into ingots that solidify. The ingots are then adjusted
to proper and uniform temperature and physically squeezed into the desired
shape in rolling mills. A newer variation of the process is to cast the
steel from the steelmaking furnace continuously, thereby minimizing the
rolling that is required.
The process sounds simple, but in reality it is rather complex. There
are many ancillary processes and operations to contend with; e.g., sintering,
coke production, scarfing, and galvanizing.
The iron and steel industry is not limited to large integrated plants;
smaller plants are spread throughout the country. In these miniplants, scrap
steel is melted in electric arc furnaces with little or no refining, then
rolled and formed into simple shapes (e.g., concrete reinforcing rods) to meet
local marketing needs. Other small iron and steel plants melt scrap in cupolas
or electric resistance furnaces. The molten iron and steel at these foundries
is cast into desired shapes.
Studies, started in 1968, have shown that effluents from the iron and
steel industry are quite large and originate from a multiplicity of sources
(see following illustrations).
Since these studies clearly showed that coke production was the most
serious pollution source in the industry, IERL-RTP directed its initial efforts
toward controlling that source. With work underway on controlling emissions
from coke production, IERL-RTP has now expanded its outlook—initiating projects
in other areas of the industry, in addition to cokemaking.
169
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, RECOVERED ONES FROM
t PARTICULATE CONTROL EQUIPMENT.
MILL SCALE
#• 8. F. GAS
CONVENTUAL
CASTING UNIT
I
TO PRIMARY
CONTINUOUS
CASTING
BILLET UNIT
BREAKDOWK
TO PRIMARY
BREAKDOWN'
CONTINUOUS
CASTING
SLAB UNIT
BORINGS
AND
TURNINGS
Iron and steel industry unit operations (sheet 1 of 2).
-------
PRIMARY BREAKDOWN
TO BLOOMS
PRIMARY BREAKDOWN
TO BILLETS VIA BLOOMS
PRIMARY BREAKDOWN
TO SLABS
FROM CONTINUOUS
-»
i
FROM INGOT
CASTING
»-
FROM CONTINUOUS ~"
BILLET CASTING
i
^ y
— k
i
h
i k P
^ HOT S
K MIL
SLAB CASTING
6
MILL SCRAP
DIRECT SHIPMENTS OF INGOTS, SLABS
BILLETS, BLOOMS
HEAVY STRUCTURALS
AND RAILS
HEAVY STRUCTURALS,
RAILS
BAR AND ROD
NAILS AND WIRE,
WIRE, PRODUCTS
BARS,LIGHT STRUCTURA
-> INCLUDING REBAR,
WIRE RODS
COLD FINISHED
BARS
SEAMLESS PIPE, TUBE
WELDED PIPE
COLO REDUCTION
AND FINISHING
GALVANIZING
TIN PLATING
AND OTHER
PLATED PRODUCTS!
PLATE MILL
SEAMLESS PIPE,
TUBE
WELDED
HOT ROLLED
SHEET AND STRIPS
GALVANIZED PRODUCTS
TIN AND OTHER
PLATED PRODUCTS
COLD ROLLED SHEET
AND STRIP, BLACK PLAT
PLATE
Iron and steel industry unit operations (sheet 2 of 2).
-------
ro
Fugitive |
Emissions !.
-j •«<
: FLne Particulates,
Hydrocarbons,
Carcinogens, CH,
NH_, Smoke
Individual
processes
Fine Particulates,
S02, F, Cl,
Volatilized Oil
~*ww SINTER
PLANT
Charging
Leaking door seals
^- Pushing
Quenching
COKING PLANT
w
•P
C
It!
O
CL,
Excess NHo Liquor
light oil recovery
wastes quench water
overflow waste water
coke wharf
Fine Particulates,
Fume
B.F. Gas
Fine Particulates,
N~, CO, CO , HO,
HCN Z Z
r
CAST
HOUSE
Cooling Water
(once through)
Granulation!
Scrubber water,
phenols, solids,
fluorides, etc.
Fine Particulates
C00, SO , NO , ZnO,
2. x x
Fluorides
Sludge
-*• SOLID DISPOSAL
SOLID DISPOSAL
Fine Particulates
"Kish" Fume, CO,
—,_.._______—__<^
I?-'1—6 Fugitive Emissions I
High Dissolve
Solids
1
SLUDGE
Fine Particulates
Fume, Smoke, CO,
C02, N02, ZnO, Oil
Vapor
, - ,
I Surface runnoff :
I '•
! water I
ELECTRIC FURNACE
CONTINUOUS CASTING
BILLET AND SLAB UNIT
Discharges From iron and steel industry (sheet 1 of 2).
-------
Particulates, Fume
co
Grinding
Scarfing
PLATE MILL
DIRECT SHIPMENTS OF
INGOTS, SLABS,
BILLETS AND
HEAVY STRUCTURALS
MILL
BAR AND ROD
NAIL AND WIRE
PRODUCTS MILL
Solids
Oil
Grease
SEAMLES^PIPE
AND TUBE
COLD FINISHING
BAR MILL
Contact Cooling
Water
Precleaning and
Rinse Waters
Solids
Acids
Oils
TIN
PLATING
TIN PLATE AND OTHER
COATED PRODUCTS
Discharges from iron and steel industry (sheet 2 of 2).
-------
Since 1975, the Battelle-Columbus Laboratories have been involved in the
characterization of emissions from metallurgical processes. This work has
provided support to IERL-RTP in source testing and emission analysis from a
variety of metallurgical processes.
A new contract being negotiated will provide environmental assessment and
technology evaluation support on a continuing basis for basic iron and steel
and ferroalloy processes.
The uses and fate of lubricants, oils, greases, and hydraulic fluids in
the iron and steel industry are being examinelTbyn^ciYic'EnvironmentaT'ServicesV
Inc. All uses of these substances are being;identified and the movements of
them through the processes to the environment are being investigated. An ex-
amination will be made of possible methods of controlling discharges into the
environment.
A contract to Hydrotechnic Corp. will examine the feasibility of demon-
strating zero water discharge and minimum air pollution discharge at a single
steel plant. Economic, technical, and time requirements will be determined.
Specialized environmental assessment and control programs have been ini-
tiated in the areas of mining, beneficiation, and pelletizing; cokemaking;
sintering; ironmaking; steelmaking; ferroalloys; hot forming and cold finish-
ing; surface preparation and finishing; fugitive emissions and runoffs; and
abnormal operating conditions. An iron and steel cooperative program, developed
under a U.S./USSR environmental agreement, has focused on making each partici-
pant aware of the other's technological advances in pollution control. The
program has matured to the point that cooperative efforts will soon be starting.
MINING, BENEFICIATION, AND PELLETIZING
Domestic iron ore production is about 90 million tons per year, of which
about 83 percent is from the Lake Superior region. Minnesota accounts for 65
percent of the total, Michigan, about 16 percent, and Wisconsin, 1 percent.
The remaining production is from 17 other states. Production comes from over
50 mines, most of which are of the open-pit type. Open-pit mines produce ap-
proximately 90 percent of the U.S. iron ore. Principal iron ore minerals are
the iron oxides, with the carbonates and sulfides being of secondary importance.
Most ores currently recovered are beneficiated to an iron ore concentrate,
using methods that vary from simple to complex. Most of the concentrates are
pelletized prior to shipment. A typical, though simplified, flow pattern for
a taconite plant is shown below.
174
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CRUSHING PLANT
, COARSE ORE BINS
FINE ORE BINS
BLASTING LOADING HAULING
GYRATORY
CRUSHERS
Vs*ROD MILLS
VIBRATING
SCREENS
CONCENTRATE THICKENERS_J
DISC FILTERS
CONCENTRATOR
ROUGHER
MAGNETIC
SEPARATORS
ADDITIVES
AGGLOMERATING PLANT
BALLING DRUMS
CLEANER" MAGNETIC SEPARATORS
CONCENTRATE
BINS
I TO TAILING
I DISPOSAL
* AREAS
I
RECOVERED
WATER
TAILING THICKENERS
FURNACES
OR KILNS
HYDRO SEPARATORS
TO STEEL MILLS
Mining, benefication, and pelletizing operation.
-------
A 1-1/2 year contract was let in July 1975 to Midwest Research Institute
as the first phase of a program which is intended to demonstrate techniques
or systems for the control of emissions from the iron ore mining, beneficia-
tion, and pelletizing industries. The purposes of this first phase are: (1)
to identify the emission sources; (2) to quantify these emissions; (3) to
prioritize these emissions based on their environmental impact; and (4) to make
recommendations for future research, development, and/or demonstration proj-
ects to reduce emissions from those sources determined to be most critical.
The contract effort to date has been to accumulate data by literature
search, by talking with industry and government personnel, and by plant visits.
Major effort has been on source identification, finding source test data,
making measurements where data is sparse, noting plant-to-plant similarities
and differences, and discussing with plant personnel the control devices at-
tempted on various process points and their reasons for selection of one de-
vice over others.
The effort for these sources may ultimately be expanded to include water
pollution aspects of the program.
COKEMAKING
Control of emissions in cokemaking is a major IERL-RTP contribution to the
iron and steel industry. It is the process which produces the most air pollu-
tion in the industry, itself one of the major air-polluting industries. Top-
side coke oven workers have been shown to have a substantially higher risk of
lung cancer than the average worker, probably from carcinogenic materials
associated with the particulate fraction.
Enclosed Coke Pushing and Quenching
IERL-RTP and the National Steel Corporation are funding a demonstration
of the enclosed coke pushing and quenching system on National's new Weirton
Steel Division Brown's Island coke plant. The conventional coke pushing and
:quenching system, used throughout the industry, involves pushing the incan-
descent coke from the sealed coking oven through a guide into an open,
shallow-bed car for transport to a batch-type quenching station. Substantial
emissions of smoke and particulate are discharged into the atmosphere through-
out this operation. This situation is aggravated if the push contains incom-
pletely carbonized coke. At the quench station^ large quantities of water are
poured into the bed of hot coke. The instantaneous formation of steam results
in the discharge of large quantities of entrained particulates to the atmosphere.
176
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In the EPA/National Steel system (shown below), the coke is completely
enclosed from the moment it leaves the oven until after it is quenched. Emis-
sions evolved during the push and transfer to the quench station are drawn off
and removed by means of a high-energy scrubber on the gas-cleaning car. Emis-
sions evolved from the hot coke in the underground track hoppers are also con-
trolled by a high-energy scrubber. The relatively low-volume continuous steam
plume generated during the continuous quenching operation is contained by hoods
and controlled by a vapor suppressor in the stack.
Current information indicates that this system will apply to nearly all
new coke batteries. This is particularly significant because at least half
of the existing coke batteries are at least 20 years old. Based on an average
life of 30 years, nearly half of the 250 existing batteries will have to be
replaced in the next 10 years. Since continuous cokemaking processes may not
be available until the end of that period, most new batteries will be conven-
tional slot ovens with useful lives extending well into the next century. Dem-
onstration of this system will provide proven emission control technology which
can be integrated into the initial plant design.
.- COKE
HANDL
EMERGENCY
'COKE QUENCH
• SYSTEM AND
WHARF
COKE'
GUIDE
GAS HOOD
.CLEANING
CAR'
HOT COKE
TRANSFER
CAR :
' SPRAY WATER '
' AND STEAM - -
I EXHAUST SYSTEM-
TRACK HOPPER
FUBE EXHAUST
AND .GAS
SYSTEM
TRACK HOPPER
FUME EXHAUST
AND GAS
CLEANING SYSTEM
COKE
HANDLING
.EMERGENCY
COKE DUMP
PIT
TRACK
RECEIVING
HOPPERS
EPAVNational Steel coke pushing and quenching system.
177
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It is estimated that the system being installed to serve the single 87-
oven Brown's Island battery will cost $4 million over and above the cost of
a standard pushing and quenching system. Expansion to serve a second battery
will cost another $1.8 million (1972 dollars).
Start-up, originally targeted for December 1972, was delayed six months
due to an explosion to the battery basement. Start-up actually occurred in
May 1973.
Excessive wear in sludge pumps and in quenching units took some time to be
resolved. Also, thermal effects on track hopper gates and roofs were diffi-
cult to obviate.
Extensive modifications to the track hopper gates and roofs, to the coke
feeders and quench units, and to the hopper fume pollution control system are
complete. Testing will be completed in the spring of 1977. Ambient air meas-
urements were taken to develop data on background pollution levels prior to
restart of battery.
The Phase 2 effort consists of long-term emission testing and a system
evaluation program to establish the system's emission control potential; sys-
tem operability, reliability, and maintainability, and the system's operating
cost. This is accomplished by:
0 Extensive tests across the various control devices to determine both
the quantity of emissions generated and the efficiency of the control
devices.
0 Maintaining complete records of coke production, maintenance performed,
malfunctions, and utility requirements.
0 Continuously monitored ambient air concentrations of particulate at
various locations around the coke plant.
0 Extensive measurements of water quality to identify water pollutants
in the effluents, as well as the potential air pollutants if the water
were used to quench coke.
Phase 2 test and evaluation results will be contained in a final report, due to
be published in mid-1977.
Smokeless Coke Pushing
IERL-RTP contracted with the Ford Motor Company to test and evaluate the
pushing emission control system developed by Koppers Company and installed on
the "A" battery of Ford's River Rouge plant, Dearborn, Michigan. Principal
features of the system are a fume-collecting hood, a fume main, a venturi
178
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scrubber, and a modified quench car with a synchronization system for coordi-
nating the quench car's movement with that of the pusher (see diagram below).
Since the control system apparently will fit most, if not all, existing
coke batteries, demonstration of the Ford system will make available to the
industry a relatively low-cost device capable of significantly reducing coke
oven pushing emissions. The greatest application of this system will be on
existing coke batteries which it will serve as an interim solution until these
batteries can be replaced (average battery life is 30 years) and a more com-
plete control system can be installed.
The test and evaluation portion of the study included examination of
operating and maintenance records, long-term system observation, determination
of system capture efficiency, and source testing for a number of pollutants
both before and after the venturi scrubber of the captured effluent. Data on
capital and operating costs were developed as well as data on utility and labor
requirements, system reliability, and control effectiveness. The final report
will be completed early in 1977. The design manual was published in September
1974.
Guidelines for Coke Oven Pollution Control Applicability
To encourage industry application of EPA-demonstrated coke oven air pol-
lution control technology, there is a strong need for a set of guidelines
showing specifically how the technology can be applied to each type of U.S.
coke battery. Each of the demonstrated systems discussed above was designed
specifically for the host coke battery; two of these—the EPA/AISI Smokeless
Coke Charging and the Ford Smokeless Coke Pushing—were retrofits to existing
batteries. The control technology demonstrations were designed and operated
to co-exist with existing features and operating techniques of the host bat-
tery. Minor battery modifications were required in some cases. Although
basic features must be adhered to in applying the technology, there are a
number of design, construction, and operating options available that can be
used to meet the requirements set by the battery features. Likewise, there
are a number of battery specifications which must be met, if only by battery
modification, to accommodate the control technology.
In addition to EPA-demonstrated projects, the sequential charging tech-
nique called "staged charging," first disclosed in 1961 by M. R. Meades and
G. E. C. Randall of the United Kingdom, has recently been perfected by the
private sector and applied to existing batteries. This technique involves
179
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00
o
BUTTERFLY VALVE,
FOR SUCTION !
RELIEF
V r"!i~~ir*ii' !i JOfn!
0 LJLJULJLJLJLJ
CYCLONE i
4-SEPARATOR;
COK_E GUIDE
FUME HOOD
gBAFFLEj!'/
p. PLATES! if
!i *S • "^.r
LOCOMOTIVE!
WATER RECIRCULATING:
PUMPS ' RECIRCULATING
WATER TANK
Koppers/Ford coke oven smoke emission abatement system.;
-------
some physical alterations to the charging components but is mainly dependent
on the precise manual execution of specific procedures for good pollution con-
trol. On the other hand, the EPA/AISI Smokeless Coke Oven Charging System,
also a sequential charging technique but of a different type, has the demon-
strated potential advantage of a fully automated system in achieving repeata-
bility of operation. A system which adapts the automated methods of the EPA/
AISI system to the requirements of staged charging would be expected to per-
form, on a repeatable basis, better than either of the two basic approaches.
Therefore, even though staged charging was not demonstrated by EPA, its ap-
parent compatibility with one of the demonstrated EPA systems makes it a
worthy candidate for an applications study.
Such a study would define both the salient features of demonstrated con-
trol technology and U.S. coke batteries and show how the control technology
can be meshed with the batteries in the most technically feasible and economi-
cal way.
Accordingly, a 12 month project has been started (July 1976) to develop
guidelines for application of demonstrated coke battery air pollution control
technology to existing and new coke batteries. Specific control technologies
to be examined include the EPA/AISI Smokeless Coke Oven Charging System, the
Enclosed Coke Pushing and Quenching System, the Smokeless Coke Pushing Sys-
tem, and staged charging (industrial development). The guidelines will examine
characteristics of the control system that are important in design, construc-
tion, and operation and relate these characteristics to application of the
control systems to U.S. coke batteries based upon examination of their charac-
teristics and requirements. The final report will be used by coke producers
in planning the application of the control technology and by regulatory of-
ficials in specifying air pollution control strategies and enforcement actions.
Characterization of Coke Oven Door Emissions
Gases, particulates, and condensible organic materials being emitted from
ineffective coke oven door seals are suspected of containing a number of toxic
substances. Since these emissions have not been sufficiently quantified or
analyzed, it is the purpose of this task to do so. The results of the study
will be used to set future program priorities.
The sampling method being used was developed under contract with Battelle-
Columbus Laboratories. During early trial runs, the system for capturing emis-
sions worked well except that the hood and door temperatures rose sufficiently
181
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high to cause excessive door leakage, making the test nonrepresentative. De-
tailed thermal analyses were performed on the coke oven door and sampling
apparatus; modifications to the hood solved the temperature problem. Samples
taken included coke and coal, gaseous, particulate, and condensible organic
samples. Analyses performed included GC-MS, Spark Source MS, High Resolution
MS, and toxicology studies. This study will be completed in January 1977.
Improved Coke Oven Door Seals
The leakage of gases and organic volatiles from coke oven end closures is
a major pollution problem in the iron and steel industry. The problem can be
partially solved by good operating practices and maintenance. However, com-
pletely solving the leakage problem will require significant advancement in the
state-of-the-art of coke oven end closure. To this end, a program has been
undertaken by IERL-RTP, cofunded on a 50-50 bas.is with the American Iron and
Steel Institute (AISI). The first phase of the program, started in June 1975,
was recently completed. The study by Battelle-Columbus Laboratories was de-
signed to define the causes of the leakage, identify the operating conditions
which must be tolerated by the sealing material, investigate other work being
done in this area, and conceptualize improved methods to eliminate coke oven
.door leakage. Of the 45 sealing concepts produced by Phase I, two were selected
(one an alternative) for further development and demonstration. The primary con-
cept is of the metal-to-metal type; the alternative concept is of the compres-
sible, elastomer type.
The Phase II contract was signed in August 1976. This phase will develop,
fabricate, and test selected sealing concepts. This will be accomplished in
eight tasks, including:
0 Mathematical modeling and analysis of coke oven sealing systems.
0 Physical modeling and laboratory experimentation.
0 Field data collection.
0 Analysis, evaluation, and recommendations.
0 Full-scale unit design and component testing.
0 Fabrication and installation.
0 Planning and completion of field evaluation.
0 Analysis and preparation of manuals and final report.
SINTERING
Sinter, in the iron and steel industry, is an iron-bearing material suit-
able for charging into a blast furnace. The sintering process combines natural
182
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ores of fine particle size and iron-bearing wastes recovered from various other
steelmaking processes (e.g., flue dust, mill scale, and settling basin solids)
with coke breeze and limestone. Limestone is added to provide the required
flux for the iron-bearing material when processed in the blast furnace; the
coke breeze is used for ignition purposes. This raw material is then charged
onto pallets, which retain the material while permitting combustion air to
pass through the bed, igniting the coke breeze and fusing the other material
into a cake. The cake layer is then broken, cooled, classified, and finally
charged to the blast furnace to recover the iron metal.
The combustion gases and excess air handled by the main exhaust fans as a
result of the sintering process force large volumes of air to pass though the
long, moving sinter bed. This exit stream contains particles and gases of
varying chemical composition. First-generation air pollution abatement equip-
ment in the form of cyclone separators is incapable of achieving desired levels
of pollutant control. These cyclones remove the large particles thus prolong-
ing fan life; but the fine particles, hydrocarbons, and gaseous pollutants are
not removed.
Wide experience in the United States indicates that electrostatic precipi-
tators are not effective in controlling emissions to meet no-visible-emission
standards. The problem is due both to the hydrocarbon content of the gases,
and the high basicity of the particulate matter which causes increased
resistivity. Baghouse tests indicate that the blinding of bags is a problem
due to the moisture/hydrocarbon/dust mixture found in the exhaust gases. Wet
scrubbers, at present, appear to be most likely to succeed in removing con-
taminants including hydrocarbons from the exhaust gases; however, substantial
power is required to get the necessary pressure drop across the scrubber for
these volumes of gases.
A new concept in sintering practice (see following illustration) recycles
gas, after preliminary cleaning and prior to final cleaning, back to the
sinter bed. Field testing information and engineering evaluations indicate
that this recycling reduces both the emissions of unoxidized hydrocarbon
particulates and the final gas volume being discharged. Although the emission
reduction may be substantial, it is anticipated that a low-energy air pollu-
tion control system must be used along with'recycling to remove remaining
.contaminants, primarily particulates.
183
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RE'CYCLE HOOD
STACK IGNITION FURNACE
RECYCLE GAS
CONTROL HOUSE
WASTE GAS
CONTROL HOUSE
Weirton Steel Division sinter plant gas recirculation syste;,i.
-------
A project was initiated in mid-1973 covering two phases. Phase I consisted
of an historical review and a detailed engineering design. This was completed
,in 1975: the final report included a theoretical analysis of recycle applica-
tion to the Weirton No. 2 machine showing optimum level of-recycle to be 39
percent.
The Phase II contract, for test and evaluation, was awarded in February
1975; the final report is scheduled for February 1978. The contractor is to
perform an optimization of the recycle system, followed by an extensive emis-
sion testing and system evaluation program. Also to be tested is a large-scale
gravel bed filter on the sinter plant exhaust both with and without recycle.
The recycle system was installed (at company expense) and has been operat-
ing for 18 months. Sinter machine operation and sinter quality have shown an
improvement as a result of recycle. The optimization program will continue to
investigate recycle rates greater than the theoretical optimum. Tests to date
have shown that recycle as high as 40.7 percent can be achieved without adverse
effects on sinter quality or machine operation.
The gravel bed filter system was placed in operation in February 1976, 1
month ahead of schedule. A number of problems have arisen with this first-of-
a-kind installation which have delayed the start of the emissions testing pro-
gram. Several problems associated with mechanical deficiencies (e.g., poorly
designed backflush valve guides which resulted in insufficient cleaning of
the filter beds, and inadequate filter media support screens which led to
screen failures and loss of media) have been effectively resolved. The most
serious problem is the growth in the physical size of the original filter media
(natural garnet) due to accretion of the particulate in the gas. After this
phenomenon became apparent alternative media materials were evaluated. It was
found that steel grit does not "grow." All filter beds were changed
over to steel grit during the fall of 1976; the filter system was restored to
operation on December 1, 1976, and after 1 month's operation, there did not
appear to be any increase in media size. Testing will now get underway to
evaluate both the recycle system and the gravel bed filter system.
A 1976 task evaluated the desulfurization of sinter plant gases using data
from power plants, a USSR sinter plant, and a Japanese sinter plant. Conceptual
designs and cost estimates were made on both a normal, once-through system and
a wind-box recirculation system.
185
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Basic oxygen process 1 ton capacity pilot vessel.
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IRON AND STEELMAKING
Blast Furnace Cast House Emission Control
There is a need to develop technology for controlling emissions from
blast furnace cast houses. The cast house is the semi-enclosed area around
the blast furnace base containing the furnace tapping equipment and molten pig
iron (hot metal) and slag distribution systems. The hot metal, the principal
emission source, is saturated with carbon as it exits from the furnace. Re-
jection of the graphite, in the form of flakes, begins as soon as the hot metal
starts to cool. Thermal air currents sweep these flakes into the air. Addi-
tionally, particles of iron oxide are formed and carried away simultaneously.
In 1976, a study was completed by Betz Environmental Engineers for pre-
liminary designs of cast house emission control schemes: first, as tailored to
existing cast houses, as defined by model cast houses which encompass the
existing population; and second, as an integral feature of a new installation.
Each cast house/control system combination was analyzed in detail to establish
the emission control potential, capital and operating costs, impact on current
operating practices, potential risks involved, and follow-on development needs.
Another 1976 study on blast furance slips was completed by Battelle-
Columbus Laboratories. This study focused on contributing factors to hangs
and slips, determining the frequency of slips, evaluating slips as sources of
air pollution, and evaluating options for control or elimination of slips.
Basic Oxygen Process Charging Emission Control
The rate of growth of the Basic Oxygen Process (BOP) for making steel has
been phenomenal. In a relatively short time, it has become the dominant steel-
making process in the U.S. iron and steel industry.
The basic operations involved in producing steel by the BOP process are
charging scrap, charging hot metal, oxygen blow, chemical tests, and tapping.
The emissions evolved during charging of the BOP furnace include extremely
fine particles of iron oxide, hydrocarbons present on the cold metal portion
of the charge, graphite particles, and volatile materials that may be present
on the cold metal. These could include potentially hazardous emissions from
elements such as cadmium, which is often present as plating on the metal.
lERL-RTP's approach to solving this problem was first to construct the 1
ton capacity pilot vessel facility (shown abovei) to be used as the vehicle for
evaluating a wide range of methods to control the charging emissions.
187
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Accordingly, a contract was signed in mid-1973 with the National Steel
Corporation: to review past efforts to control BOP charging emissions; to
characterize operation, emissions, and BOP vessel and shop configurations; to
project future construction trends; and to define charging control concepts
and (from them) to develop technology for controlling the particulates, gases,
and fumes emitted during charging of BOP steelmaking vessels. This develop-
ment program concentrated on process modifications that will allow the emis-
sions to be collected. Consideration was also given to suppression of the
emissions within the vessel. Specifications and conceptual designs were
developed for prototype emission collection systems. Additional specifica-
tions were developed for a gas cleaning system to be added to the prototype
collection system. The development program is structured so that the results
will be applicable to the total industry. The final report was completed in
1976. ._ _ '._ ......
A project started in 1975 by Dravo Corporation evaluated the composition,
quantities, methods of disposal, and resource recovery state-of-the-art for
sludges and dusts collected by air and water pollution control equipment in the
steel industry. This study was completed in 1976.
A follow-on study assessed the potential for the creation of environmental
problems from the disposed residues from steelmaking furnaces. This 1976
study by the Research Triangle Institute examined chemical and physical prop-
erties of the residues, assessed the leaching of hazardous metals and organics
from the residues, and examined the potential for metals to migrate through
soil, water (both surface and subsurface), and air.
Ferroalloy Production
The ferroalloy industry's principal source of emissions is the submerged
arc electric furnace. (See ferroalloy production process diagram, following.)
In this furnace, ferroalloys are usually-smelted by reducing the ore with car-
bon, producing both the desired metal lies and substantial quantities of CO (in
some cases, more CO is produced than metal!ics). Gases evolved from ferroalloy
furnaces entrain large quantities of particulates which, because of the high
temperatures involved in the reaction zone, are primarily in the submicron
size range. Domestic ferroalloy furnace practice has been to leave the furnace
top open, thus allowing the CO to mix with large volumes of air and burn above
the furnace. This mixture is then collected and treated with conventional
particulate control equipment before being vented to the atmosphere.
. 188
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RAW MATERIALS HANDLING, PREPARATION AND CHARGING-
MELTING AND CASTING-
^FUGITIVE EMISSIONS^
oo
VO
JHMDDST
— OFFGASES-t I
SOLIDS
CRUSHING WEIGH-FEEDING
PRODUCT SIZING AND HANDLING
I
SURFACE WATER
RUN-OFF
Ferroalloy production process.
-------
Some newer furnaces in Europe and Japan are hooded tightly so that no ex-
cess air is entrained in the furnace off-gas and combustion does not take place
above the furnace. When such a system (known as a totally enclosed furnace)
is used, the volume of gas is decreased by 20 to 200 times, since excess air
is not entrained. This decreased quantity of emissions can be cleaned to the
.same level as emissions from an open furnace; therefore, total particulate
emitted is decreased by approximately the same factor of 20 to 200. Addition-
ally this gas, which is no longer burned over the furnace, can then be used as
a low-Btu fuel after cleaning.
United States ferroalloy producers hesitate to install totally enclosed
furnaces (diagram follows), feeling that they may reduce the ability to change
from one ferroalloy product to another. (The standard of performance reflects
this industry position.) Under contract to IERL-RTP, Battelle-Columbus Lab-
oratories published a report, "A Study of Ferroalloy Product Flexibility," in
1975 that essentially supported the industry's arguments. Battelle concluded
in general: (1) that totally enclosed furnaces are not as flexible as open
furnaces of the same size; (2) that large furnaces are less flexible than
smaller ones; (3) that research should be undertaken to investigate approaches
(such as the substitution of iron ore pellets for ferrous scrap) to smooth out
furnace operation, thereby improving the flexibility problem; and (4) that EPA
should undertake an investigation of the overall pollution problems (including
air, water, and solid wastes) associated with ferroalloy production.
A number of ferroalloy furnace particulate emission samples were obtained
from EPA's Office of Air Quality Planning and Standards for detailed analysis.
These samples had been taken in conjunction with the development of New Source
Performance Standards for ferroalloy furnaces. However, they were never
analyzed for specific organic constituents or trace metals. Subsequent tests
performed by Battelle-Columbus Laboratories identified extremely high concen-
trations of polycyclic organic materials (POM) in samples from totally enclosed
ferromanganese furnaces. Since the samples had been in storage over a year
before analysis and the exact history of the samples is not known, further
testing and analysis is being accomplished to confirm these preliminary results.
Depending on the outcome of the tests and how thoroughly the ROMs are
destroyed by flaring and by conventional wastewater treatment, a decision will
be made as to the priority to be given this problem in future programs.
190
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ELECTRODES
IGAS OFFTAKE
INDUCED
. AIR
FEED
TAP
HOLE
FURNACE
INDUCED;
AIR
Open-hooded ferroalloy furnace.
FIXED:
SEALSi
lCOVER
ELECTRODES
r^
MIX
H
.MIX
GAS'OFFTAKE
FURNACE
Enclosed ferroalloy furnace with fixed seals.
191
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SURFACE PREPARATION AND FINISHING
As a result of hot-forming operations, a black oxide scale is formed on
the surface of the steel. This scale must be removed prior to the finishing
steps. Pickling is normally used for scale removal.
Pickling is accomplished by immersing the steel in acid baths (usually
using hydrochloric or sulfuric acid) and then rinsing with water to remove the
excess acid. The content of metal salts increases in the bath to the extent
that the acid must be replenished. Waste streams from the process include the
acid waste (pickle liquor) and the acidic rinse water. These wastes can pre-
sent considerable environmental problems.
In 1974, "-a 3 year"grant "was" awarded to Crown""Chemical" for the develop-
ment of a closed-loop recycle system for waste sulfuric acid pickle liquor.
The process, designed to eliminate all discharges from the pickling process,
uses:" "a" continuous couhTercurrent~fori" exchange""contactorTorTron recovery
from a ferrous sulfate feed, nitric acid stripping, air oxidation, and a
hydrolizer.
Many basic steel products require surface treatments prior to use. One
of these is tinning. Wastes from the tinning operation are usually handled in
the same manner as pickling. A project, started in 1973 and finished in 1976,
assessed the use of countercurrent rinsing using a compartmentalized Hnsing
tank to reduce the amount of water required and to facilitate recovery of
chemicals from the wastewater. Thus, this system reduces the amount of blow-
down and increases the concentration of the plating solution in the blowdown,
making it easier to treat subsequently.
FUGITIVE EMISSIONS AND SURFACE RUNOFF
During the past several years, it has become increasingly obvious that
significant amounts of particulate and gaseous emissions are being emitted to
the atmosphere from sources other than the stacks in a number of Industrial
operations, An Investigation performed by The Research Corporation (TRC) for
EPA Indicates that several metallurgical processes are Included 1n those In-
dustries which most characteristically demonstrate a high degree of fugutlve
emissions. Several additional EPA Investigations have similarly suggested the
need for fugitive emission research and the development of control techniques
for metallurgical processes.
IERL-RTP contracted with Midwest Research Institute (MRI) in June 1975 for
the first phase of a program which is intended to define or develop techniques
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or systems for the control of fugitive emissions from a number of metallurgical
processes. The purposes of Phase I are: (1) to characterize fugitive emis-
sion sources in integrated iron and steel plants, primary copper and lead
smelters, and iron foundries; (2) to prioritize these emissions; (3) to deter-
mine the environmental impact of these emissions; and (4) to make recommenda-
tions for future research, development, and/or demonstration projects to aid in
the reduction of fugitive emissions from those sources determined to be most
critical.
Thus far, MRI has identified the specific fugitive emission sources within
the subject industries and prepared generalized process diagrams indicating
these sources. An effort is currently being made to quantify each of the iden-
tified emissions. It is expected that this project will be completed in 1977.
Surface runoff from steel mills has become of increasing concern due to
an awareness that runoff can have a potentially serious environmental effect.
A current contract with The Research Corporation (TRC) is evaluating sources
of surface runoff within the iron and steel industry, assessing the overall
problem of runoff, determining the contribution of individual sources to the
overall problem, and determining control technology needs. It is anticipated
that this project will be completed by mid-1977.
ABNORMAL OPERATING CONDITIONS
Operational "upsets" are frequent causes of violation of air and water
pollution standards. To supplement and support efforts being made to minimize
the adverse effects of upsets, there is a need for information concerning mal-
functions" an"d~th"e"fr~Tdehtity,~causeV~resultTng" discharges", prevention, and mini•
mization. A contract was awarded to the Research Triangle Institute (RTI) in
1976 to study this problem.
Under this contract, abnormal operations in coking, sintering, blast
furnace ironmaking, and in open hearth, basic oxygen, and electric furnace
steelmaking will be studied. Products of this study will include:
0 A description of abnormal conditions, their cause, their adverse ef-
fect on pollutant discharges, and the total environmental problem that
they represent.
0 An evaluation of the state-of-the-art for preventing and controlling
abnormal operations.
0 Prioritized lists of technology development needs to increase the capa-
bility to control pollutants during period of abnormal operations.
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0 Manuals of practice to eliminate or reduce discharge from abnormal
operations and conditions.
Iron and Steel Foundry Processes
The cupola (see following illustration) is a vertical shaft furnace into
which ferrous scrap and pig iron, coke, and limestone are charged. The combus-
tion of the coke provides heat to melt the metal!ics, forming cast iron which
is poured into molds. The limestone serves as a fluxing agent, removing im-
purities in the other charge materials. The cupola has been in widespread use
for centuries; however, over the past 10 to 15 years its position has been
severely challenged by electric arc and induction furnaces due to their rela-
,tive ease of emission control. However, since the oil embargo and subsequent
large increases in the cost of electrical energy, there has been a definite
reversal of this trend. The control of cupola emissions is costly; technology
for improving the cupola's energy utilization to offset these costs is
available but has not realized widespread application in the U.S.
lERL-RTP's principal effort in this vital industry involved a program
directed toward an in-depth engineering analysis of the various integrated
systems for energy conservation and air pollution control which are or have
been in commercial use, or which appear to offer potential for commercial de-
velopment. The analysis of each system utilized actual operating data when-
ever possible to determine capital and operating costs, emission control
capability, energy savings, and operating and maintenance procedures and re-
quirements.
This effort showed that many foundries can achieve substantial energy
savings just by paying closer attention to operating and 'maintenance procedures,
with little or no added cost. Additionally, 20 to 30 percent coke savings can
be realized either by changing to a divided blast (two rows of tuyeres, instead
of the usual single row) for cold-blast cupolas, or by installing recuperators
in the exhaust to recover the now-wasted heat, transferring it to the blast air.
The divided blast option requires a small capital investment. The recuperator
is somewhat more expensive; however, if used to replace a separately fired
blast air heater (as is often the case in systems now in operation), the fuel
savings will pay for the recuperator in a year or two. The final report on
this effort was published in May 1976.
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METAUICS
in
^—-^ ~i^^>
COOLING AND
CLEANING
SAND
PREPARATION
Iron foundry process emission sources.
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Nonferrous Metallurgy
Although lERL-RTP's nonferrous smelting program was transferred to IERL-
Cincinnati in late 1975, two projects in this area remained at IERL-RTP be-
cause of the nearness of their completion and this Laboratory's long-term
familiarity with the projects.
These projects are separate efforts conducted under EPA's Special Foreign
Currency Program (PL-480) in Yugoslavia to define emissions from copper, lead,
and zinc smelting'. The projects were conducted by the Bor Copper Institute
and the Trepca Lead and Zinc Institute, respectively. Objectives of both
projects are similar: (1) to determine emissions from the smelting processes
under study, (2) to relate amounts of emissions to changes in feed and process
conditions, and (3) to determine the effect of SOX control equipment on emis-
sion of other pollutants, particularly hazardous particulates. An extensive
sampling and analysis program was conducted to determine both the input
materials and their fate in out-going streams for each smelter unit operation.
Mineralogical and elemental analyses were made on all solid material streams;
gaseous streams were analyzed for SOX, NOX, CO, COg* and other gaseous pollu-
tants and for particulate mass and size distribution.
Although project final reports have been prepared by the Yugoslavs, they
have had to be Anglicized by a domestic contractor to be suitable for U.S.
publication. These Anglicized final reports are now being reviewed in draft
form prior to official publication.
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PROCESS MEASUREMENTS
The main areas of activity within lERL-RTP's Process Measurements Branch
(PMB) are directed toward development of measurement methods for testing and
quality assurance. The current major thrust of the PMB's work is in support
of lERL-RTP's environmental assessment program.
CONTROL EQUIPMENT EVALUATION
In conjunction with efforts aimed at control equipment evaluation, two
major program areas are active. These areas are Particulate Measurement and
Chemical Analysis and Sampling.
Particulate Measurement
Beginning with efforts that led to the EPA method 5 mass sampling train
in the mid-1960's, the PMB has been involved in developing the particulate
mass measurement techniques required by control equipment engineers to evalu-
ate particulate abatement systems. High-volume mass measurement equipment has
been developed to obtain accurate samples from high-efficiency control devices
in a reasonable and cost-effective period. Instrumental methods including
optical transmission, charge transfer and beta gauging have been tested for
use as continuous monitors for specific processes.
PMB initiated activities in 1972 to develop and apply particle sizing
techniques, recognizing that the fractional efficiency of particulate control
devices may be very important from a biological standpoint. In situ sizing
was established as the only reliable technique due to serious problems with
loss of particles in probes and changes in sample integrity. An intensive
method evaluation program was initiated, and manual sizing based on inertial
fractionation has been developed into a useful tool. A standard procedures
manual for the use of cascade impactors has been published. Cyclone separators
have been developed for obtaining large quantities of sized material for
subsequent chemical and biological tests. Cyclones have been constructed with
Sharp cut points at as low as 0.3 microns, and a system (which can potentially
replace impactors) is being built.
Instrumental techniques evaluated for particle sizing include optical
single particle counters and automatic readout of inertial separators for
particles greater than 0.2 microns. Diffusion/condensation and electrical
mobility for ultrafines are in use and are being further developed.
Mist eliminator efficiency measurements were identified as being required
to evaluate particulate and sulfur dioxide scrubbing systems. Manual methods
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. were adapted from solids measurements for short-term information. An instru-
ment development program for droplet sizing was started using a hot wire
detection technique. A prototype unit demonstrated the viability of the
concept both in the laboratory and field situation. A second-generation unit
has been developed utilizing more rugged probes. A system for automatic and
continuous determination of efficiency is being developed based on the newer
model.
The trends in particle measurement are toward high bulk size separation
using manual methods for environmental assessments and automatic continuous
,mass and size for control device evaluation. The manual methods are more
cost-effective for the environmental assessment activities and the basic
techniques have been established. Automatic methods can drastically reduce
the time and cost of parametric research studies and are also necessary for
non-steady state processes.
High-Temperature/Hiah-Pressure Sampling and Measurement
The initial efforts by PMB to develop measurement techniques for high-
temperature and/or high-pressure (HTHP) gas streams were in support of the dry
limestone S02 control process in the late 1960's. Specially designed water-
cooled, gas-moderated probes were used to extract samples from the firebox to
determine the reaction chemistry of the process. During the same period, a
. holographic system was used on a large operating boiler to determine the
distribution of the limestone cloud within the boiler.
During 1972, projects were initiated on probe sampling of flames for
major chemical species and on holographic interferometry for determining
.turbulence and temperature profiles in the flame zone. In 1973, development
of a laser velocimeter for particle velocities in flames was undertaken. A
contract effort has recently been started to develop in situ techniques for
flame composition.
Particle sizing systems were designed for laboratory- and miniplant-scale
fluidized-bed combustion (FBC) projects. The laboratory scheme involved
sampling the whole streams while an HTHP extractive system was installed at
the miniplant. Both units operated successfully.
Recently, sampling metFods have been developed" for permanent installation
and long-term operation. The high pressures (300 psig) and temperatures
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(1800°F) have significant safety problems associated with them for both the
personnel and the process hardware. Two probe systems for gaseous and particu-
late sampling will be installed at the Exxon miniplant. A water-cooled liquid-
moderated probe has also been developed for sampling high-temperature sources.
Future developments in the area of HTHP will be aimed at extending the tech-
nology to include HTHP sampling and measurement in coal liquefaction and
gasification processes.
Inorganic'Sampling and Analysis
The Process Measurements Branch has been involved in the sampling and
analysis of inorganic species since 1967. The early program focused on the
manual methods for the analysis of S02, S03, HF, and NOX emission from sta-
tionary sources. In 1968, the direction of the inorganic sampling and analyti-
cal efforts was expanded to include process measurements to support the develop-
ment and engineering evaluation of limestone injection and wet limestone flue
gas desulfurization programs. The process measurements which were evaluated
and implemented included S02, S0o» Ca, Mg, SO^, and SO^ analysis in scrubber
process liquor streams, effluent gas from the scrubber, and inlet gas to the
scrubber. Overall material balance closures for 90 percent calcium and sulfur
were achieved. A program to monitor trace inorganic elements was initiated to
.evaluate the effects of selected elements on scrubber chemistry! e.g., oxida-
tion of sulfite to sulfate. This program was expanded to develop and promul-
gate sampling and analytical systems for a broad range of inorganic elements
in a variety of process streams which include liquids, slurries, solids,
particulate matter, and gases.
Chemical analysis of species in low-Btu gasification dates back to 1972
when emissions from the Applied Technology molten iron combustor system were
evaluated. Recently, the first-generation procedures to evaluate the environ-
mental effects associated with coal gasification processes were published.
Technical assistance has been provided to the following programs: flue
gas desulfurization (measurements of SO^SO.,, scrubber liquor concentrations,
composition of emitted particulates); fluid bed combustion (analysis of bed
.material, emitted particulates, and S03); physical coal cleaning (development
of a trace elements sampling and analytical program); and the combustion modi-
fication program (effects of low NOV emission combustion on trace elements
A
distributions).
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In response to changing information needs of IERL-RTP, programs have been
initiated in the following areas: development and promulgation of a sampling
and analytical system for identification of oxidized inorganic compounds;
development and promulgation of a sampling and analytical system for the
quantisation of reduced inorganic species (^S, COS, AshL, H^Se, etc.); and
development of techniques to determine coal sulfur forms to support the physical/
chemical coal cleaning program.
Organic Measurements
Organic materials emitted to the environment have received increasing
attention, especially in the last several years. Past programs concentrated
on measurements of specific compounds, such as the carcinogenic polycyclic
hydrocarbons. In the last year, the emphasis of development programs has
shifted to less specific, less quantitative, but much more comprehensive
survey techniques. The survey methods have many applications, but are being
developed primarily for application to environmental assessment programs being
carried but by the engineering branches of IERL-RTP. Survey methods for a
wide range of organics have been evaluated and a cost-effective system chosen
for use in assessment programs. Testing and evaluation of survey methods
continues, and revisions will be made when needed.
Important advances have been made in both sampling and analysis of the
polycyclic organic materials (POM). The number of compounds analyzed has been
increased, and heterocyclic carcinogens are now included in the analysis for
POM, although they had been traditionally ignored. Sampling for organics has
evolved from the use of liquid-filled impingers to the modern porous polymer
adsrrbent systems. Studies are underway at present to further extend knowledge
of trapping efficiencies, capacities, and general properties of adsorbent
materials, especially XAD-2 and Tenax GC.
A program of method evaluation and application for analysis of pollutants
of special interest is underway. Analysis of polychlorinated biphenyls in
stack effluent, water streams, and fish is required for several IERL-RTP
programs. Sampling for these compounds does not appear to be especially
-problematical, but analysis techniques are very difficult and prone to error.
Inter-laboratory comparisons are underway as well as close scrutiny of methods
in use on IERL-RTP projects.
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ENVIRONMENTAL ASSESSMENT TESTING STRATEGIES
A major effort has been initiated by the IERL-RTP to provide a comprehen-
sive data base on the emissions from industrial and energy processes. In
order to implement the field work necessary for these studies, the Process
Measurements Branch has developed a phased sampling and analytical strategy to
provide comparable data from the many processes to be studied. The phased
approach was selected as the most cost-effective technique for insuring that
potential problem areas would be identified and resources expended on the most
critical problems. Strategies for fugitive emissions and biological testing
have also been developed for environmental assessment programs.
Phased Sampling and Analytical Strategy
The first phase, Level I, utilizes a series of qualitative, semiquantita-
tive (± 2) techniques to provide preliminary prioritization of future work.
The emphasis is directed toward completeness through evaluation of all poten-
tial sources of pollution. Physical, chemical and biological tests are per-
formed on all samples collected. The estimated costs of this phase range from
$25,000 to $105,000 depending on plant complexity. A sampling system for
survey work has been developed and tested, and a procedures manual for Level I
sampling and analysis has been issued.
A high-volume, series cyclone sampling system was developed for IERL-RTP
under contract by Walter C. McCrone and Southern Research Institute. The
design was fabricated and field-tested at ten industrial sites by TRW, Inc.
The sampling system operated during the field tests without a major failure.
A new version has been designed and construction of the prototype was begun in
1975. The complete system, designated the Source Assessment Sampling System
(SASS), illustrated below, is available commercially.
Level II efforts are directed toward identification and quantification of
specific compounds. Emphasis is on refinement of the data base for sources
which have been shown to be potential problems by Level I screening. The
costs of Level II are estimated to range from $250,000 to $1,250,000. These
costs are a function of plant complexity and the number of potential problem
areas identified.
Level III is envisioned as an evaluation of the time and process param-
eter effect on pollution problems. Based on Level II data, cost-effective
measurement technologies are used to monitor specific materials during contin-
, uous process operations. Cost data has not been developed for Level III
because it is a highly site-specific type of measurement.
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SASS equipment for environmental assessment sampling.
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Two aspects of environmental assessment receiving particular emphasis are
fugitive emissions and biological testing. Development of programs in both
these areas continues.
Fugitive Emissions
Fugitive air emissions are defined as those pollutants which are not
emitted from stationary sources through ducts of regular cross section. For
many industrial categories (e.g., oil refineries, coke plant nonferrous smelt-
ing, and coal gasification/liquefaction), fugitive emissions have been shown
by use of emission rate/ambient air dispersion predictive models to be a major
air problem. A program was developed to identify, validate, and promulgate
sampling and data reduction strategies for these emissions. Documents have
been developed for the following strategies: Upwind/Downwind, Roof Monitor,
and Quasistack. The strategies address two distinctly different IERL-RTP data
needs: a) environmental assessment which requires "screening" techniques and
b) techniques to evaluate the efficiency of fugitive emissions control technology.
Efforts have also been initiated for the measurement of fugitive water
pollution sources. Studies to develop a sampling strategy to evaluate and to
determine receiving body impacts of storm water runoff from material storage
piles in the iron and steel industry and from coal storage piles at power
generating stations are presently in progress.
The first symposium devoted solely to fugitive air and water emissions
was sponsored by PMB in Hartford, Connecticut, in May 1976.
Technical assistance on fugitive emissions will be continued and expanded.
Major activities include recommendation of a fugitive air/non-point source
water runoff program for a physical coal cleaning demonstration program, a
fugitive emissions program for the environmental assessment of the coal gasi-
fication complex at Kosovo, and cooperation with the National Institute of
Occupational Safety and Health (NIOSH) in collecting samples to evaluate the
fugitive emissions potential of the Hygas process.
Biological Testing
Biological testing of IERL-RTP samples has grown from novel curiosity
status to become an important part of the analysis schemes for environmental
assessment programs. The most attractive feature of biotesting is that it
provides direct evidence of complex synergistic, antagonistic, and bioavaila-
bility effects, which cannot usually be predicted from even the most complete
chemical analysis.
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Initial application of biotests to IERL-RTP samples was carried out by
Health Effects Research Laboratory-RTF using the rabbit alveolor macrophage
test for acute cellular toxicity. Results were sufficiently encouraging that
application was made to a series of carefully obtained and fractionated partic-
ulate samples. Extensive chemical analysis was also carried out on the same
series of samples, and the Bruce Ames test for mutagenic behavior was ultimately
added to the test program. It was found possible to rank the acute toxicity
behavior of the material, and two weakly positive tests for mutagenesis were
observed. One of the mutagenic samples has since been observed to be carcino-
genic when tested with the hamster embryo system.
Current and near-future work is centered about generation of approved
test batteries for application to IERL-RTP projects, especially environmental
assessments. A joint committee made up of members from ORD's Office of Energy,
Minerals and Industry (OEMI) and Office of Health. and Ecological Effects (OHEE) labora-
tories is resporisibleTor recommendation of~suTtable methods7~"Draft" outline""methods
for inclusion of initial survey studies have been received and are undergoing
further review. Tests included are the rabbit alveolor macrophage cytotoxicity
test, the bacterial mutagenesis test (Bruce Ames test), fathead minnow test,
algae growth, mouse range finding toxicity test, soil litter microcosm, and
plant stress ethylene production. This battery would give fundamental informa-
tion concerning toxicity, mutagenesis (presumptive carcinogenesis), and
aquatic and terrestrial ecology effects. Marine ecology tests are also being
generated for application where appropriate.
Application of these tests and improvement in sampling, sample handling,
.and the development of techniques for relating biological test data to chemical
information will be necessary for some time and are included in current plans.
QUALITY ASSURANCE
The "Planning Document for Control Systems Laboratory Quality Assurance
Program," prepared for IERL-RTP in December 1974, was the initial effort in
this area. This report originally identified five categories of projects
having common characteristics as to size, duration, objectives, and data
quality requirements. Projects within a given category can thus effectively
use the same general set of quality control and quality assurance (QA) prac-
tices and procedures. More recently, an IERL-RTP Data Quality Manual has been
developed and issued. This manual incorporates concepts being developed in a
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continuing effort to provide IERL-RTP with an effective data quality program.
A sixth category has recently been added; the current list of categories is:
Environmental Assessments
Industry System Studies/Pollutant System Studies
Field Studies
Research and Bench-Scale Projects
Development of Pilot Programs
Demonstration Projects
During 1975 and early 1976, guidelines for implementation of quality
assurance and quality control on demonstration projects were developed and
trial-implemented in the field on the EPA/Shawnee wet limestone scrubber
project. After this test, a procedures manual was issued for quality assur-
ance on demonstration projects. A guideline document dealing with quality
assurance and control on environmental assessment projects is nearing comple-
tion, and establishment of an effective laboratory-wide program continues.
Procedures for QA programs will be developed for all six project categories
and will be the basis for implementing quality assurance on individual projects.
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Appendix A
THE INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY,
RESEARCH TRIANGLE PARK
The Industrial Environmental Research Laboratory, Research Triangle Park
(IERL-RTP) has completed its sixth full year of activity as part of the U.S.
Environmental Protection Agency. Formerly titled the Control Systems Labora-
tory, it is involved in a variety of technical and management functions
directly related to the research, development, and demonstration of equipment
and systems designed to abate environmental pollutants from stationary sources
to a level that is conducive to increased health and welfare.
Although the Laboratory officially came into being in 1970, along with
EPA, as a result of Reorganization Plan No. 3 it actually predates that.
Before its days with the Office of Research and Development, it was known as
the Control Systems Division, part of EPA's Office of Air Programs. IERL-RTP
traces its history through the Department of Health, Education, and Welfare
(HEW) where, as part of the Environmental Health Service, it was the Division
of Process Control Engineering (DPCE), a division of the National Air Pollu-
tion Control Administration (NAPCA). NAPCA's predecessors were the National
Center for Air Pollution Control (NCAPC) and the Division of Air Pollution.
Federal involvement with air pollution control actually dates back to
July 1955 when the U.S. Congress authorized a Federal program of research
and technical assistance to state and local governments. At that time, the
still-standing policy was established that: (1) state and local governments
have a fundamental responsibility for dealing with community air pollution
problems, and (2) the Federal government has an obligation to provide leader-
ship and support.
In December 1963, Congress passed the Clean Air Act when it was evident
that, although progress was being made toward a better understanding of pol-
lution problems, comparable progress was not being made toward controlling
the problems. Basically, the 1963 Clean Air Act:
0 Authorizes awarding Federal grants to state and local agencies to
assist in developing, establishing, or improving pollution control
programs.
0 Authorizes Federal action to abate interstate pollution problems
beyond the reach of individual states and cities.
A-l
-------
0 Expands the Federal pollution research and development program.
0 Emphasizes investigation of sulfur oxides pollution from coal and oil
combustion.
0 Requires the development of criteria on effects of air pollution on
health and property.
0 Emphasizes the role of the Federal government on controlling air pol-
lution from its own facilities.
The next significant step was Congressional passage of the Air Quality
Acts of 1967 and 1970, also referred to as the "Clean Air Act, as amended."
These amendments not only called for an attack on pollution on a regional
basis, but also provided a blueprint for action at all levels of government
and among all segments of industry. Features of the 1970 law are:
0 The entire nation is covered by 247 Air Quality Regions.
0 National Air Quality Standards have been established for all pollutants
covered by the air quality criteria documents.
0 EPA may establish emission performance standards on new stationary
sources which emit any substantial amount of pollutants so as to
'cause or contribute to endangerment of health or welfare.
0 EPA is establishing National Emission Standards for Hazardous Pollutants.
0 EPA may establish emission standards for new sources of pollutants
which have adverse effects on health and which are not covered by
National Ambient Air Quality Standards or by Hazardous Pollutant
Standards.
0 Emission limits have been established for designated pollutants from
motor vehicles, and a time frame for achieving these standards has
been defined.
0 The Federal standards do not preclude the setting of more stringent air
quality standards by the states.
The same 1970 law outlines a specific six-point research program to be
carried out by EPA, emphasizing research into and development of new and im-
proved methods (with industry-wide application) for the prevention and control
of air pollution resulting from the combustion of fuels by:
0 Conducting and accelerating research programs directed toward develop-
ing improved low-cost techniques for--
00 Control of fuel combustion by-products.
00 Removal of potential air pollutants from fuels prior to combustion.
A-2
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00 Control of emissions from fuel evaporation.
00 Improving the efficiency of fuel combustion so as to decrease air
pollution.
00 Producing synthetic or new fuels which, when used, result in de-
creased air pollution.
° Providing Federal air pollution control grants and contracts.
0 Determining, by laboratory- and pilot-scale testing, the results of
air pollution research and studies in order to develop new or improved
processes and plant designs to the point where they can be demonstrated
on a large and practical scale.
0 Constructing, operating, and maintaining (or assisting in meeting the
cost of) new or improved demonstration plants or processes which
promise to accomplish the purposes of the Clean Air Act.
0 Studying new or improved methods for recovering and marketing commer-
cially valuable by-products resulting from the removal of pollutants.
On July 9, 1970, the President sent Reorganization Plan No. 3 of 1970 to
the Senate and the House of Representatives. This Plan, establishing EPA, com-
bined certain of the pollution-control-related functions of six Federal
agencies:
0 The Atomic Energy Commission.
0 The Council on Environmental Quality.
0 The Department of Agriculture.
0 The Department of Health, Education, and Welfare.
0 The Department of the Interior.
0 The Federal Radiation Council.
lERL-RTP'S ORGANIZATION
The position of IERL-RTP in EPA is shown in Figure A-l. The Laboratory
has four main groups. The Office of Program Operations functions as a program
monitoring and evaluating group. The other three groups, all programmatically
(rather than functionally) oriented Divisions, are engaged in work ranging
from small-scale experimental work and exploratory research, through pilot-
plant-size experimental work, to prototype evaluations of equipment large
enough to permit confident scale-up to full-size commercial installations. The
title of each Division indicates its area of concentration.
lERL-RTP's objective is to ensure the development and demonstration of
cost-effective technologies to prevent, control, or abate pollution from
A-3
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ADMINISTRATOR
EPA
ASSISTANT ADMINISTRATOR
RESEARCH AND DEVELOPMENT
I
DIRECTOR
OFFICE OF ENERGY,
MINERALS, AND INDUSTRY
1
UTILITIES AND
INDUSTRIAL POWER
DIVISION
^m
M
^m
PROCESS
TECHNOLOGY
(REGENERABLE)
BRANCH
EMISSIONS/EFFLU-
ENT TECHNOLOGY
(NON-REGEIMERABLE)
BRANCH
PARTICULATE
TECHNOLOGY
BRANCH
DIRECTOR
DEPUTY DIRECTOR
INDUSTRIAL ENVIRONMENTAL
RESEARCH LABORATORY, RTP
1
1 1
ENERGY ASSESS-
MENT AND CON-
TROL DIVISION
•
PH
••
COMBUSTION
RESEARCH
BRANCH
ADVANCED
PROCESSES
BRANCH
FUEL ~~
PROCESSES
BRANCH
1
INDUSTRIAL
PROCESSES
DIVISION
CHEMICAL
PROCESSES
BRANCH
METALLURGICAL
PROCESSES
BRANCH
PROCESS
MEASUREMENTS
BRANCH
OFFICE OF
PROGRAM
OPERATIONS
SPECIAL
STUDIES
STAFF
PLANNING,
. MANAGEMENT, AND
ADMINISTRATION
STAFF
TECHNICAL
INFORMATION
SERVICE
Figure A-1. Organization of the Industrial Environmental Research Laboratory,
Research Triangle Park.
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operations with multimedia environmental impacts associated with the extrac-
tion, processing, conversion, and utilization of energy and mineral resources
and with industrial processing and manufacturing. The Laboratory also sup-
ports the identification and evaluation of environmental control alternatives
of those operations as well as the assessment of associated environmental and
socioeconomic impacts. lERL-RTP's program, consisting of inhouse activities,
contracts, grants, and inter-agency agreements, contributes significantly to
the protection of the national health and welfare through the research and
development effort of timely and cost-effective pollution control technology.
It is much easier to state lERL-RTP's objective than to acquire the in-
puts (shown in Figure A-2) which are required to develop a rational program
for this Laboratory. Fortunately, EPA "sister" laboratories possess all the
necessary expertise to carry out this function.
As in most activities, problem definition is the first key event in
solving the air pollution problem. EPA's regional offices play a major role
in this activity by determining the research and development needs of each
region. The other major inputs come from our legally mandated responsibility
and other designated EPA sources. This information, along with health effects
data, allows priorities to be set for pollutants. The list of pollutants (by
priority) leads to industry studies .which determine the sources and amounts
of pollutants emitted and identify the currently available control technology.
With the Ambient Air Quality Standards fixed, regions are identified
where the standards are violated. Next, the complicated problem of relating
emissions to ambient concentrations of pollutants must be solved. Following
the solution of the problem, IERL-RTP determines what emission reductions can
be attained with best-available technology and how much this reduction will
cost: modeling determines if reductions will allow Ambient Air Quality Stand-
ards to be met. If additional new technology is required, IERL-RTP can
mount a research, development, and demonstration program to provide this
technology, in cooperation with the private sector.
A-5
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MANDATED
R&D RESPONSIBILITIES
INDUSTRY AND
POLLUTANT
IDENTIFICATION
t
.INDUSTRY STUDY
»
-^
R&D NEEDS FROM REGIONS,
ERG'S, OAWP, AND EPA
ADMINISTRATOR'S DIRECTIVES
PRESENT AMBIENT
CONCENTRATION
BY AQCR
SOURCE EMISSION
DATA
CURRENTLY AVAILABLE
CONTROL TECHNIQUES
CONTROL REQUIREMENTS
NAAQS, NSPS,
NESHAPS
CONTROL STRATEGY (REGIONAL AND NATIONAL)
CONCENTRATION OR EMISSION LEVEL WITH
BEST AVAILABLE TECHNOLOGY
(ECONOMICS INCLUDED)
ADDITIONAL CONTROL REQUIRED
I
IERL-RTP
PROGRAM
I
IMPACT NEW AMBIENT CONCENTRATIONS
EMISSIONS, ECONOMICS
PRIORITIES
FINANCIAL AND
OTHER CONSTRAINTS
Figure A-2. The basis for IERL-RTP programs.
A-6
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Appendix B
METRIC CONVERSION FACTORS
Although EPA's policy is to use metric units for quantitative descrip-
tions, this report uses certain nonmetric units where it is felt that doing
so will facilitate understanding by a majority of the readers of this report.
Readers more familiar with metric units may use the following factors to
convert to that system.
Nonmetric
atm
bbl
Btu
°F
ft
ft3
gr
in.
Ib
ton (short)
Multiplied by
1.03
158.99
252
5/9 (F - 32)
30.48
28.32
0.06
2.54
0.45
907.18
Yields metric
2
kg(wt)/cm
liters
cal
°C
cm
liters
g
cm
kg
kg
B-l
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