INDUSTRIAL ENVIRONMENTAL RESEARCH
LABORATORY-RTF
ANNUAL REPORT
1975
'"**•••/
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
1975
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
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
1i
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FOREWORD
This annual report presents the highlights of the programs and
accomplishments of EPA's Industrial and Environmental Research Laboratory--
Research Triangle Park, between January 1 and December 31, 1975. 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 the first such report identified with the abbreviated
title, IERL-RTP, it is not a new one. Rather it is a continuation of a
series of such reports describing the activities of people who have 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 implemen-
tation 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, processing, 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 interagency agreements, contributes
significantly to the protection of National health and welfare through the
research and development of timely and cost-effective pollution control
technologies.
iii
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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 the affected industry, but ultimately every-
one. 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 indicates 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, 1976 Dr. John K. Burchard
Director
Industrial Environmental
Research Laboratory, RTP
IV
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TABLE OF CONTENTS
Foreword i i i
Illustrations xi
INTRODUCTION 1
ENVIRONMENTAL POLLUTION CONTROL 5
Sulfur Oxides (SO ) 5
A
Nitrogen Oxides (NO ) 8
Particulates x 10
Other Pollutants 10
PROGRAM METHODOLOGY 12
IERL-RTP PROGRAM AREAS 13
Utility and Industrial Power 13
Flue Gas Desulfurization Technology 13
Waste and Water Pollution Control 15
Flue Gas Treatment for NO Control 16
Thermal Pollution Control 16
Particulate Control Technology 17
Energy Assessment and Control 18
Nitrogen Oxides Control 18
Fluidized-Bed Combustion 23
Coal Cleaning 24
Synthetic Fuels 27
Advanced Oil Processing 29
Other Support 30
Industrial Processes 32
Chemical Processes 32
Metallurgical Processes 33
Transient Operation 33
Process Measurements 34
Program Operations 34
Special Studies 34
ENERGY ASSESSMENT AND CONTROL 37
COMBUSTION RESEARCH 37
Fundamental Research 39
Combustion Chemistry 40
Combustion Aerodynamics 42
Fuels Research and Development 44
Process Research and Development 48
Field Testing and Assessment 52
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Table of Contents (con.)
ENERGY ASSESSMENT AND CONTROL (con.)
FUEL PROCESSES 58
Fossil Fuels—Coal 59
Coal Contaminant Characterization 59
Coal Cleaning 61
Technology Development 63
Physical/Mechanical Coal Cleaning 63
Chemical Coal Cleaning 65
Synthetic Fuels 67
Environmental Assessment 68
High-Btu Gasification 68
Low-Btu Gasification 68
Liquefaction 69
Control Technology Development 70
Fossil Fuels—Oil 72
Oil Composition 72
Oil Treatment/Processing 72
Demetallization 72
Desulfurization 72
Denitrification 73
Effluent Controls 73
Fossil Fuels—Gas 73
Fossil Fuels—Other 74
Waste as a Fuel 74
ADVANCED PROCESSES 77
Fluidized-Bed Combustion 77
Fluidized-Bed Combustion of Coal 77
Fluidized-Bed Gasification/Desulfurization
of Residual Fuel Oil 82
Advanced Low-Emission/Energy-Conserving Systems/
Strategies 82
EPA-Van 83
Heat and Emission Loss Prevention System
(HELPS) 83
Electrical Energy and Waste Heat 85
Fuel Distribution Pattern Flexibility 85
UTILITIES AND INDUSTRIAL POWER 87
PROCESS TECHNOLOGY 87
Flue Gas Desulfurization—Regenerable Processes 87
Magnesium Oxide (Chemico Mag-Ox) Scrubbing 87
Sodium Sulfite/Bisulfite Scrubbing with
Thermal Regeneration 89
Catalytic Oxidation (Monsanto Cat-Ox) 92
Citrate Process 95
Sodium Hydroxide Scrubbing with Electrolytic
Regeneration 95
vi
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Table of Contents (con.)
Page
UTILITIES AND INDUSTRIAL POWER (con.)
Ammonia Scrubbing with Bisulfate Regeneration 99
Activated Carbon 101
Reductant Gases 103
Non-Utility Combustion Source Control 103
Marketing Abatement Sulfur/Sulfuric Acid 105
Engineering Applications/Information Transfer 106
Flue Gas Treatment/NO Removal 107
J\
Catalytic Reduction of NO with Ammonia 107
xv
Catalysts for Controlling NO Emissions 108
A
Advanced Concepts for NO Control 109
J\
NO Control Strategy Assessment 109
/{
NO Flue Gas Treatment Pilot and Prototype Projects 110
EMISSIONS/EFFLUENT TECHNOLOGY 111
Flue Gas Desulfurization—Non-regenerable Processes 111
Lime/Limestone Wet Scrubbing 111
TVA's Shawnee Power Plant 112
lERL-RTP's Pilot Plant 114
City of Key West 116
Bahco Process 117
Double-Alkali 117
Technology Development 118
General Motors Industrial Demonstration 118
Full-Scale Utility Demonstration 119
Survey of FGD Systems 119
Flue Gas Desulfurization—Waste and Water Pollution
Control 119
FGC Waste Disposal Methods 121
FGC Waste Characterization, Disposal Evaluation,
and Transfer of FGC Waste Disposal Technology 121
Shawnee FGD Waste Disposal Field Evaluation 121
Louisville Gas and Electric Evaluation of FGD
Waste Disposal Options 121
Lime/Limestone Scrubbing Waste Characterization 123
Characterization of Effluents from Coal-Fired
Power Plants 123
Ash Characterization and Disposal 123
Alternative Methods for Lime/Limestone
Scrubbing Waste Disposal 124
Alternative FGC Waste Disposal Sites 124
FGC Wastes Utilization ._ 124
VI1
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Table of Contents (con.)
UTILITIES AND INDUSTRIAL POWER (con.)
Lime/Limestone Scrubbing Waste Conversion
Pilot Studies 124
Gypsum By-product Marketing 125
Fertilizer Production Using Lime/Limestone
Scrubbing Wastes 125
Power Plant Water Reuse 125
Thermal Pollution Control 126
Cooling Technology 126
Waste Heat Utilization 128
PARTICULATE TECHNOLOGY 129
lERL-RTP's Parti oil ate Program 130
Measurement 130
Characterization and Improvement of Conventional
Control Equipment and Assessment of the
Collectability of Dusts 130
New Particulate Control Technology Development 131
New Idea Evaluation and Identification 131
High-Temperature and High-Pressure Particulate
Control 131
Accelerated Pilot Demonstrations 131
Current Program Status 131
Measurement 131
Characterization and Improvement of Conventional
Control Equipment 132
Electrostatic Precipitators 132
Scrubbers 133
Fabric Filters 137
Assessment of the Collectability of Dusts 139
New Particulate Control Technology Development 139
New Idea Evaluation and Identification 141
High-Temperature/High-Pressure Particulate Control 142
Accelerated Pilot Demonstrations 143
INDUSTRIAL PROCESSES 145
CHEMICAL PROCESSES 145
Fabricated Metal Products 148
Petrochemicals 149
Ethylene Dichloride (EDC) Processes 149
Vinyl Chloride (VC) 150
Polychlorinated Biphenyls (PCBs) 150
Inorganic Chemicals 151
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Table of Contents (con.)
INDUSTRIAL PROCESSES (con.)
Agricultural Chemicals 152
Fertilizer 152
Pesticides 154
Herbicides 156
Food Products 157
Combustion 157
Mechanical Cooling Devices 158
Hazardous and Toxic Emissions from Industrial
and Utility Boilers 159
Refineries 159
Sulfur Oxides Control 160
Automobile Filling Station Control 161
Construction 161
Textiles 161
Miscellaneous Industries 165
Asphalt Roofing 165
Glass Manufacture 166
Asbestos Materials Fabrication 166
Flare Systems 167
Vegetative Stabilization of Mineral Waste Heaps 167
GUIDELINES FOR ENVIRONMENTAL ASSESSMENT OF ENERGY SYSTEMS 168
METALLURGICAL PROCESSES 169
Ferrous Metallurgical Processes 169
Mining, Beneficiation, and Pelletizing 170
Steelmaking 172
Coke Oven Emission Control 172
Smokeless Coke Charging 172
Enclosed Coke Pushing and Quenching 178
Smokeless Coke Pushing 180
Guidelines for Coke Oven Pollution
Control Applicability 182
Characterization of Coke Oven Door
Emissions 183
Improved Coke Oven Door Seals 184
Blast Furnace Cast House Emission Control 185
Sinter Plant Windbox Emission Control 185
Basic Oxygen Process Charging Emission
Control 188
Iron Foundry Processes 190
Characterization and Control of Ferroalloy
Furnace Emissions 192
Fugitive Emissions 196
Control of Effluent Discharges 198
U.S./USSR Task Force on Abatement-of Air
Pollution from the Iron and Steel Industry 201
IX
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Table of Contents (con.)
INDUSTRIAL PROCESSES (con.)
Non-ferrous Metallurgical Processes 201
Control of Lean S02 Streams 201
Application of Flue Gas Desulfurization
Technology 202
Application of Gas Stream Blending Technology 202
Application to Specific Smelters 203
Control of Fugitive Emissions 203
Environmental Evaluation of New Metal-winning
Processes 204
Development of Emission and Control Data Base 204
Emission Characterization and Control—Transient
Operation 205
.PROCESS MEASUREMENTS 207
Control Equipment Evaluation 207
Particle Measurement 207
Chemical Analysis and Sampling 208
Environmental Assessment Testing Strategies 210
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 NOX emissions from coal-fired
utility boilers 9
4 Environmental assessment/control technology
development diagram 19
Total NOX emitted in the U.S. from stationary
sources (1972) 38
Experimental system for combustion modification
and future fuel studies 45
225-KW gas turbine used for IERL-RTP in-house
studies 49
Precombustion chamber diesel (300 HP) for
stationary engine controls development 50
Scotch marine boiler (60 HP) for emission control
equipment evaluation 57
Hypothetical simplified gasification flow
diagram 62
TRW Meyers process for coal desulfurization 66
Controlling hydrocarbon emissions from gasoline
bulk storage/loading terminal 75
The City of St. Louis municipal incinerator
demonstrates recycling of household solid
waste 76
630-KW Exxon mini pi ant for pressurized
(10 atm) fluidized-bed combustion of coal 80
Artist's conception of EPA-Van - - 84
EPA/Boston Edison demonstrate Mag-Ox process 88
XI
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Illustrations (con.)
Figure No. Title Page
Wellman-Lord process to be demonstrated 91
EPA/Illinois Power demonstrate Cat-Ox process 93
The Citrate process 96
WEPCO's Valley plant pilots Stone & Webster/Ionics
process 98
Ammonia scrubbing with bisulfite regeneration 100
Activated carbon process 102
Versatile lime/limestone wet scrubbing demonstration
at Shawnee plant 113
IERL-RTP lime/limestone scrubber pilot plant 115
Three 20-MW prototype FGD systems at Gulf Power's
Scholz plant 120
Test pond for disposal of Shawnee's chemically
treated scrubber waste 122
Capital cost of ESP's vs. computed performance 134
Scrubber operating cost vs. aerodynamic cut
diameter 136
Mining, beneficiation, and pelletizing operation 171
Iron and steel industry unit operations (sheet
1 of 2) 173
Iron and steel industry unit operations (sheet
2 of 2) 174
Discharges from iron and steel industry (sheet
1 of 2) 175
Discharges from iron and steel industry (sheet
2 of 2) 176
EPA/AISI coke charging system 177
EPA/National Steel coke pushing and quenching system 179
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Illustrations (con.)
Figure No. Title Page
Koppers/Ford coke oven smoke emission
abatement system 181
Weirton Steel Division sinter plant gas
recirculation system 187
Basic oxygen process 1-ton capacity pilot
vessel 189
Iron foundry process emission sources 191
Ferroalloy production process 193
Open-hooded ferroalloy furnace 195
Enclosed ferroalloy furnace with fixed seals 195
Particle sizing instruments evaluated in
lERL-RTP's aerodynamic test facility study 209
Source assessment sampling system (SASS) 212
A-l Organization of the Industrial Environmental
Research Laboratory, Research Triangle Park A-5
A-2 The basis for IERL-RTP programs A-6
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INTRODUCTION
Since 1967 the Federal Government, in cooperation with industry,
has made a determined effort to develop technology to control environ-
mental pollution produced by both stationary and mobile sources.
An organization which is 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 ORD's June 30, 1975, reorganization, however, lERL-RTP's pollu-
tion control efforts have been more encompassing. Since that date,
and with the cooperation and assistance of EPA sister laboratories pre-
viously charged with appropriate pollution control responsibilities,
IERL-RTP has effectively 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 Pollu-
tion 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 "de-
velop technology necessary to eliminate the discharge of pollutants in-
to the navigable waters, waters of the contiguous zone, and the oceans."
Sec. 105 of the Act authorizes "research and demonstration projects
for prevention of pollution of any waters by industry including, but
not limited to, the prevention, reduction, and elimination of the dis-
charge 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
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research and development program to achieve the prevention and control
of air pollution "
Two other sections of the Air Quality Acts are also significant,
indicating Congressional support of specific activities of IERL-RTP:
Section 103 (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 con-
trol of air pollution and, as part of that program, to conduct and pro-
mote the coordination and acceleration of research, investigations,
experiments, training, demonstrations, surveys, and studies relating
to the causes, effects, extent, prevention, and control of air pollu-
tion. Section 104 specifically emphasizes research into and develop-
ment of new and improved methods, with industry-wide application, of
preventing and controlling air pollution resulting from fuels combustion.
Figure 1 displays the energy requirements* that relate the problem
of air pollution 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 in a substantial manner. 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-
sufficiency 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, how-
ever, 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.
*Although 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 x 10*8 Btu
COAL (USGS TOTAL ESTIMATED): 77 x 10*8 Btu
URANIUM (LIGHT WATER REACTOR): 0.84 x 10*8 Btul
URANIUM (BREEDER REACTOR): 18.5 x 10*8 Btu
OIL
1985 -116 X 1015 Btu
100-
COAL
SSSi&d NUCLEAR AND OTHER
1972 - 72 X 1015 Btu
100-
90—
80—
I
O
O.
S 60—|
a:
LLl
S 50—1
_i
£ 40-
CXI
2 30—
20—
10—
fl-
90—
80 —
70-
60—
ea
a:
UJ
50-
40—
30—
20—
10—
'
/'
/X
0
25 50 75
IMPORTS, percent
100
I I 1"
25 50 75
IMPORTS, percent
100
Figure 1. Total U.S. energy requirement.
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9375
7500
5625
Ul
o
cc
3
O
t/j
ESSENTIALLY ALL KNOWN RESERVES MADE
AVAILABLE BY 95% EFFICIENT FLUE GAS
CLEANING PROCESSES (EXAMPLE: WELLMAN-
LORO PROCESS)
o
CJ
o
LU
3750
1875
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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ENVIRONMENTAL POLLUTION CONTROL
The development and demonstration of environmental pollution con-
trol technology is one of EPA's largest tasks. Approximately $58
million were devoted to this effort in FY 75. 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 expanded programs addressing the environmental aspects of accel-
erated energy resource development in the United States.
lERL-RTP's goal in stationary source air pollution control de-
velopment is fourfold:
0 To describe at least one method for control of each major
source of pollution.
0 To provide a technical base for the Agency's enforcement
activities.
0 To establish technical and economic data to support New
Source Performance Standards (NSPS).
0 To provide information required to make environmentally
sound decisions on energy development policy.
Sulfur Oxides (SO..)
X
Consistent with Congressional guidelines and the energy/pollution
relationships, lERL-RTP's major concern has been with the control of
sulfur oxides from fuel combustion. About 80 percent of the Laboratory's
total expenditures to date have been in this area and have been concen-
trated on flue gas cleaning.
This emphasis has been dictated by its economic feasibility, and
by its availability for near-term application as compared to other SO
X
control options. IERL-RTP has funded, either totally or partially, a
number of major projects over the past several years, including those
tabulated below.
The major demonstration projects are supported and supplemented
by other full scale testing, numerous engineering studies, and smaller
scale hardware projects. The commercial economics of FGD byproduct
marketing and disposal options, and the evaluation of new processes
and process improvements are the subjects of continuing engineering
efforts. A major effort underway in technology transfer will promote
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PRESENT AND PROJECTED FLUE GAS CLEANING DEMONSTRATIONS
Removal
Process (application) Startup efficiency. %
Large-Scale Electric Utility Application
Wet limestone scrubbing
{Shawnee-TVA: 30 MW,
coal) 4/72 75-90
MgO scrubbing
(Chemico: 155 MW, oil) 5/72 85-90
MgO scrubbing
(Chemico: 100 MW, coal) 7/74 85-90
Cat-Ox
(Monsanto: 100 MW,
coal) 12/74 85-90
Wellman-Lord
(115 MW, coal) 12/75 90-95
Smaller Scale Industrial/Commercial Application
Double alkali
(General Motors: 30 MW,
coal) 3/74 85-95
Wet limestone scrubbing
(Key West: 40 MW, oil) 1/74 60-80
aSystem has operated only for very short test
periods.
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use of the best and most reliable techniques and equipment for future
FGD installations.
A second method of reducing SO emissions is to remove sulfur and
J\
other contaminants from the fuel prior to combustion. This pretreat-
ment method of control is appropriate to SO sources smaller than
X
electric utility size; e.g., boilers and fuel-burning equipment. IERL-
RTP is supporting programs for research, development, and environmental
assessment of several approaches for removing pollutants from fuels.
One technique—coal cleaning—involves methods of physically and/or
chemically cleaning coal of moderate sulfur content so that it can be
burned in conformance with clean air standards. lERL-RTP's objectives
in this area are to develop commercially available processes for remov-
ing inorganic sulfur and ash from medium sulfur coal and, at the same
time, rendering the coal-cleaning wastes suitable for reclamation or
disposal in an environmentally acceptable manner. Another IERL-RTP
program area involves clean synthetic fuels (high- and low-Btu gasified
coal and liquefied coal). The major objectives are to determine the
potential environmental impacts of synthetic fuel processing, and to
develop control technology to minimize the negative effects of these
environmental impacts.
A third method for controlling SO involves modification of the
A
combustion process. Fluidized-bed combustion (FBC) is the primary
approach under consideration. As part of the National Fluidized-Bed
Combustion Program coordinated by ERDA, EPA is conducting R&D to de-
termine potential environmental problems arising from alternative de-
signs and use of fluidized-bed combustors. IERL-RTP's participation
in the interagency program consists of conducting environmental assess-
ments of FBC systems; optimization for control of S02> NO , fine
.A
particulates, and other pollutants; and by continued testing of IERL-
RTP's small (0.63 MW) FBC pilot miniplant.
In addition to combustion sources, industrial processes make a
significant contribution to the ambient SO problem. An effort is
X
underway to evaluate and demonstrate SO controT" by a commercial mo-
A
lecular sieve process (PuraSiv S) on tail gases from sulfuric acid
production. The evaluation shows that the molecular sieve process is
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capable of limiting the SO concentration to 100 ppm in tail gases for
A
most sulfuric acid plants. Work has also been initiated to identify
alternate technologies for reducing petroleum refinery SO emissions
to 80-90 percent below 1974 levels.
Nitrogen Oxides (NO )
A
Combustion modification is the primary existing control technique
for preventing or minimizing NO emissions from fossil-fuel burning.
X
Efforts supported and directed by IERL-RTP have shown that recircula-
ting flue gas is a most effective technique for controlling NO emis-
X
sions originating from thermal fixation of atmospheric nitrogen during
the combustion of clean fuels (natural gas and distillate oils).
Staged combustion (often combined with low excess air) is an effective
method for controlling NO emissions derived both from the thermal
X
fixation of nitrogen emissions in the combustion air and from the con-
version of nitrogen atoms chemically bound in the fuel (heavy oils and
coal). Additional IERL-RTP R&D efforts are aimed at: burner/combustor
system redesign; investigating novel combustion modification approaches
(such as catalytic combustion, advanced power cycles, and alternate
fuels) for emission reduction; and providing a basic understanding of
the physical and chemical factors influencing the formation and degra-
dation of pollutants through fundamental combustion research.
NO flue gas treatment (FGT) is a relatively new control technique
X
under investigation for its potential in accomplishing high efficiency
control of large stationary sources. A program, eventually leading to
a demonstration of the technique on large coal-fired sources, is in
direct response to increasing evidence that high level control may be
required to meet future NO standards. Since NO FGT processes are now
X X
being applied commercially in Japan on gas- and oil-fired sources, the
IERL-RTP program approach will be to import the best Japanese processes
and adapt these systems for coal-fired sources.
Figure 3 is a graphic representation of IERL-RTP's efforts to
achieve effective and economic control of NO in coal combustion, a
A
most difficult area.
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1200
innn
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as
CO
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2 600
FIELD TESTING
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71
/- PROJECTED
/ r ACTUAL
K
\ ^-.
(700 ppm) *. . . _
^. FIELD TEST *\
Vv. RESULTS. \
^°< \
RESULTS FROM FIELD x s ' v NSPS (W ^ * W$ OKI GNED
ADDI ir>ATinM nc ICT V -«w ^ '' ' uuiuctij utaiuiicu
APPLICATION OF 1ST ^v X ., WITH LOW NOX
GENERATION RETROFIT — ^^^ X. /' CAPABILITY
TECHNOLOGY — ' *>CX> ^ • *^/
"•^-o^-^.
ENGINEERING R, D & D (300 ppm) ' ' — *^
\ \
•
\ _
FUNDAMENTAL COMBUSTION RESEARCH (150 ppm) ' ' x^
\
72 73 74 75 76 77
CALENDAR YEAR
FigureS. Control of NOX emissions from coal-fired utility boilers.
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Finally, in the industrial area, IERL-RTP is currently supporting
a project to evaluate and demonstrate NO control by a commercial mo-
J\
lecular sieve process (PuraSiv N) on tail gases from nitric acid
plants. The evaluation demonstrates that the molecular sieve process
is capable of economically limiting NO concentrations to at least 100
/\
ppm and quite possibly to 50 ppm on tail gases from absorbers in nitric
acid production.
Particulates
Control technology for large particulates has been fairly well
established. lERL-RTP's efforts are now mainly concerned with develop-
ing techniques to control 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. Control technology for fine particu-
lates is still seriously deficient. lERL-RTP's present efforts center
on developing adequate detection and measurement methods and on develop-
ing and field testing control methods. Additionally, IERL-RTP is work-
ing to improve and demonstrate existing collection capability for fine
particulate control and to identify and ultimately to demonstrate novel
techniques which will offer both economic and performance advantages
over current methods.
Other Pollutants
IERL-RTP control technology research efforts are underway for a
number of noncriteria pollutants, for which no emissions standards
have been established, and for the three noncriteria pollutants
(asbestos, mercury, and beryllium) for which National Emissions Stan-
dards for Hazardous Pollutants now exist. These potentially harmful
materials ("other" pollutants) include: trace metals, polycyclic organic
matter (POM), miscellaneous hydrocarbons, fluorides, and odors.
To assess the emission of these pollutants, several tasks are being
funded by IERL-RTP for the field testing of coal-fired utility and in-
dustrial boilers, and for limited source characterization for gas- and
10
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oil-fired units. A field testing program is also planned for residen-
tial and commercial heating units.
Source assessment has also been started for certain chemical proc-
essing industries. Objectives of this IERL-RTP program are to assess
the environmental impact of sources of toxic and potentially hazardous
air emissions in the organic materials, inorganic materials, combustion,
and open source categories, and to determine the need for control tech-
nology development for given source types. Sources being assessed in-
clude petroleum refining, acrylonitrile, asphalt paving, solvent evapor-
ation operations, rubber and plastic processing, phthalic anhydride,
polyvinyl chloride, glass manufacturing, barium chemicals, fertilizer
mixing plants, brick kilns, lead storage batteries, and ammonium nitrate.
Control technology for the ferrous metallurgical industries is
under extensive development by IERL-RTP. Included in this area are
emissions from coke-making, sintering, iron-making in the blast furnace,
and steel-making in the basic oxygen furnace. Additional programs are
underway to assess and characterize fugitive emissions from integrated
iron and steel plants and from the mining, beneficiation, and pelletizing
of iron ores.
IERL-RTP efforts are underway to establish control techniques both
for open sources and for selected closed sources of asbestos. The key
sources include mining, milling, and manufacturing sites. Manufacturing
sites tend to be located predominantly in urban areas and, thus, sub-
stantially increase human exposure to asbestos. The objectives here
are to develop and demonstrate control technology for handling, unload-
ing, and disposal operations, and to demonstrate a specific methodology
for controlling closed sources of asbestos in manufacturing operations.
Completed programs include a study to identify the sources of asbestos
in the mining industry and a project to identify the optimum operating
mode for maximum efficiency of baghouses for control of asbestos fibers.
This work is undertaken to supplement control via National Emission
Standards for Hazardous Air Pollutants, since their effectiveness is
still unknown.
11
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Lastly, IERL-RTP is continuing development at the pilot plant
level for the following sources: glass manufacturing plants, refinery
crackers, asphalt roofing plants, ethylene dichloride plants, coating
operations for metal cans, hydrocarbon control for gasoline distribu-
tion systems, and odor control for the rendering industry.
PROGRAM METHODOLOGY
Over the past 7 years, the Federal Government has gained perspec-
tive and experience concerning its most effective involvement in pol-
lution control activities. The following considerations support a
federally coordinated environmental pollution control research and
development effort:
0 In order to achieve cost-effective environmental pollution con-
trol to protect health and welfare, it seems clear that regula-
tions 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 concen-
trations, 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 benefitting 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 ef-
fective 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 technically 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.
12
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IERL-RTP PROGRAM AREAS
Programs being pursued by IERL-RTP's Divisions and Branches have
been realigned to reflect the multimedia and energy-related innovations
resulting from EPA's recent Office of Research and Development re-
organization.
The newly aligned functions fall into three natural categories:
utilities and industrial power, energy assessment and control, and
industrial processes. 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
The lERL-RTP's Utilities and Industrial Power program was formu-
lated to ensure that adequate controls are available to prevent and
abate pollution from utility and industrial power sources. To achieve
this objective, the program involves multimedia research, development,
demonstration, and environmental assessment. Major elements of this
program include: flue gas desulfurization technology, waste and water
utilization control, flue gas treatment for NO removal, thermal pol-
A
lution control, and particulate control technology.
FLUE GAS DESULFURIZATION TECHNOLOGY
Flue gas desulfurization (FGD) technology is the only near-term
technological approach to utilizing plentiful high-sulfur coal supplies
without excessive deleterious SO emissions. FGD technology develop-
J\
ment and assessment, therefore, are afforded a high priority. Studies
indicate that FGD will be competitive in cost with advanced control
methods (e.g., chemical coal cleaning, fluidized-bed combustion);
therefore, FGD may play an important role in controlling emissions
even in the post-1980 time period.
FGD technology has progressed rapidly over the past 3 years.
Several commercial FGD installations are achieving high SO removal
.A
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
13
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work remains to be done in the FGD technology area, including the de-
velopment of cost-effective environmentally acceptable disposal tech-
nology for the large quantities of sludge produced from lime and lime-
stone 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 7 years, IERL-RTP has been conducting a comprehensive
FGD development and technology transfer program, which has been instru-
mental in accelerating the commercial viability of FGD technology.
This program has aimed at demonstrating reliable and cost-effective
FGD processes, yielding both nonregenerable (throwaway) products and
regenerable (or saleable) sulfur products.
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 letter's Shawnee Steam Plant. This
program has been instrumental 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 evaluation of appropriate
control practices. In order to provide a nonregenerable alternative to
lime/limestone systems, IERL-RTP is now undertaking the demonstration
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 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. EPA and TVA are working together to
-------
develop another advanced process known as amnonium scrubbing—ammonium
bisulfate regeneration. Other regenerate processes which have proven
to be promising at pilot- or prototype-scale are being, or will be,
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 a second generation
process (producing sulfur) to be selected.
WASTE AND WATER POLLUTION CONTROL
A comprehensive research and development program is being conducted
by IERL-RTP to evaluate, develop, demonstrate, and recommend environ-
mentally acceptable, cost-effective techniques for disposal and utiliza-
tion 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 dis-
posal, and ocean disposal); bench- and pilot-scale testing of FGD
sludge utilization schemes (e.g., sludge conversion to sulfur [with
regeneration of calcium carbonate]); and pilot/prototype testing of
water treatment schemes for maximizing overall power plant water recycle/
reuse. Engineering cost studies of each process/technique being de-
veloped 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 fertilizer; 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 an annual summary
report, the first of which will be issued in early 1976. Plans are to
continue current efforts to expand efforts in FGD waste utilization.
15
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FLUE GAS TREATMENT FOR NOV CONTROL
A
Another important part of lERL-RTP's environmental program relat-
ing to coal combustion is the NO flue gas treatment (FGT) program.
X
This program is designed to produce a detailed state-of-the-art tech-
nology assessment as well as an assessment of the extent to which FGT
could be used in an optimized control strategy for stationary sources.
Based on these assessments, the program is designed to provide for the
development and demonstration of FGT technology and to produce infor-
mation concerning the economic, energy, and environmental aspects of
commercial application.
The FGT program has four major elements:
0 Ongoing bench- and pilot-scale efforts directed toward NO
A
removal in the presence of low SO concentrations.
A
0 Development of control technologies to remove both SO and
NOX.
0 Evaluation of both U.S. and foreign technologies to identify
the most promising for U.S. application.
0 Larger scale prototype testing and demonstration.
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. Cur-
rent projections 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 Pollu-
tion Control Act Amendments of 1972, EPA is required to regulate thermal
effluents. lERL-RTP's research and development program in the thermal
control area is supportive of 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 1st generation cooling system performance
and economics, assessment of advanced heat rejection techniques, and
development of control technology for treatment and reuse/recycle of
cooling system effluent streams. Waste heat utilization studies pres-
ently underway involve primarily agricultural applications. Aquaculture
16
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uses may merit future consideration.
PARTICULATE CONTROL TECHNOLOGY
lERL-RTP's program for particulate control is designed to establish
engineering design techniques and performance models, and to improve the
collection capability 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; attain-
ment of the Secondary Standard (or a more stringent Primary Standard)
appears impossible without improved technology. There are two basic
causes for this: (1) particulate control technology has limited control
capability, in many cases even for coarse particulate; and (2) 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 par-
ticulates which persist in the atmosphere, comprise a variety of known
toxic substances, and are major contributors to atmospheric haze and
visibility problems. The objective is the development and demonstra-
tion of control technologies capable of effectively removing large frac-
tions of the under-3 \im size particles from effluents. The technical
approach is to identify capabilities of existing equipment (electro-
static precipitators [ESPs], filters, scrubbers, and proprietary de-
vices), to determine deficiencies in present design and operating pro-
cedures, and to pursue remedies for the deficiencies through research
and development. New concepts will be applied as discovered, and
successful 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 emitting 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 developing dust conditioning techn-iques and by modifying
the design of charging sections and collecting electrodes. During 1975,
17
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a mathematical model for the design of ESPs was completed; this will
allow cost-effective design for specific participate control tech-
nology applications. Also completed was the total characterization of
seven ESPs operating on a number of sources ranging from power plants
to aluminum plants; results show that ESPs can collect particles of
all sizes with high efficiency when dust resistivity is not a problem.
Field tests on eight scrubbers show that scrubbers are not good
collectors of fine particulate at a reasonable energy consumption.
lERL-RTP's program to improve scrubbers is directed toward using con-
densation to reduce these energy requirements.
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 objec-
tives are several energy technology areas:
0 Nitrogen oxides control.
0 Fluidized-bed combustion.
0 Coal cleaning.
0 Synthetic fuels.
0 Advanced oil processing.
0 Other support (wastes-as-fuel, conservation, advanced energy
systems).
The major activities of these programs, environmental assessment
and control technology development, can best be described in terms of
the components and their relationships as depicted in the upper (En-
vironmental Engineering) portion of Figure 4. EPA has been given re-
sponsibilities for environmental assessment and control technology
development in the energy area to ensure an independent and timely
environmental consideration of this national priority.
NITROGEN OXIDES CONTROL
IERL-RTP activities relating to NO and other combustion pollutant
.A
control include the following subobjectives:
0 NO.. Environmental Assessment/Applications Testing—Determination
""""A
of the environmental emissions of NO and other combustion-related
X
pollutants from stationary combustion sources. Evaluation of the
18
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ENVIRONMENTAL DATA ACQUISITION
Existing Data
Identify Sampling and Analytical
Techniques
Ttjl Program Dev.
Comprehensive Wisti Stream
Characterization
Input-Output Materials Characterization
CURRENT ENERGY TECHNOLOGY
BACKGROUND
Process Info
Schedules
Status
Priorities
CONTROL TECHNOLOGY DEVELOPMENT
Engineering Analysis
Basic and Applied Processes Oev.
Specific Process Dev. and Eval.
CURRENT ENVIRONMENTAL
BACKGROUND
Potential Pollutants and Impacts
in all Media
Doie/Responsi Data
Fed./State Stds. Criteria
Transport Models
ENVIRONMENTAL ENGRG
ENVIRONMENTAL SCIENCES
ENVIRONMENTAL SCIENCES
TECHNOLOGY TRANSFER
CONTROL TECH. ASSESSMENT
Control System and Disposal Option
Info and Design Princ.
Control Process Pollution and Impacts
Process Engrg. Pollutant/Cost
Sensitivity Studies
Accidental Helejj», Malfunction,
Transient Operation Studies
Field Testing
Define Best Control Tech. for Each Goa
Control Tech. R&O Recommen.
ENVIRONMENTAL OBJECTIVES
DEVELOPMENT
Est. Permissible Media Cone, for
Control Dev. Guidance (Goal III)
Define Emission Goals
Prioritize Sources Problems
Prioritize Pollutants
Control R&D Goals
Nonpollutant Impact Goals
ENVIRONMENTAL SCIENCES R&D
Health/Ecological Effects Research
Transport/Transformation Research
ENVIRONMENTAL ENCRO
TECHNOLOGY TRANSFER
MEDIA DEGRADATION AND
HEALTH/ECOLOGICAL
IMPACTS ANALYSIS
Air.Water&Land
Quality
Increiied Sickness
& Death
Ecology Related
Effects
Material Related
Effects
Quantified
Effects
Alternatives
Figure 4. Environmental assessment/control technology development diagram.
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environmental effectiveness and impact (as compared to the uncontrolled
state) of combustion control modifications including alternative operat-
ing conditions, retrofit control, maximum stationary source technology
(MSST) for existing units—extensive retrofit, and MSST for new units-
optimized design or alternate processes.
0 Develop Combustion Modification Technology for NO —Development
A
and demonstration of practical combustion modification technology for
controlling NO and related combustion generated pollutants from
A
utility boilers, commercial boilers, industrial boilers, residential
heating systems, industrial process furnaces, stationary engines, and
advanced processes.
In order to carry out this program a major contractor will be used
to perform a detailed environmental assessment and systems analysis of
the effect of application of NO combustion modification technology to
A
major stationary combustion sources. The effect on equipment and system
performance and economics will be evaluated in addition to the effect
on emission of NO and a wide range of other combustion-related pollu-
A
tants. Analyses will be performed to assess the impact of the control
technologies as applied to various sources on the environmental quality
of various regions or areas, and to investigate various NO strategy
A
options.
A series of field testing and characterization studies are being
performed for various source categories or equipment types to determine
the level of emissions without controls (baseline), as well as the
levels achievable with optimized operating conditions, with state-of-
the-art control technology, and with extensive retrofit of technology
to existing sources. Generalized engineering and analytical support
studies are being undertaken as required to accomplish objectives.
Since over 98 percent of the NO from stationary sources are
X
formed during the combustion of fuels, the logical approach to control
is the modification of the conditions under which fuel combustion
takes place. The techniques which can be used are well documented and
offer potential for substantial control of NOV (50- to 90-plus percent),
A
depending on a variety of factors. In addition, these techniques can
20
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be optimized to reduce or eliminate emissions of other pollutants
(such as CO, unburned hydrocarbon, and carbon particulate) and to in-
crease system efficiency by optimizing system design and operating
characteristics.
The approach builds on a solid technology base for conventional
fossil fuels and generates new technology for both conventional and
alternate fuels. The emphasis is on source-specific field application
of control techniques to a variety of stationary sources, including
utility, industrial, and commercial boilers; residential furnaces;
industrial process furnaces; stationary engines; and advanced processes.
The applications range from minor hardware changes on existing sources
for establishing short-term control technology to complete system
redesign for optimizing all energy and emission aspects of specific
equipment classes. The field application studies are supported and
guided by activities in: generalized burner and system development,
advanced system development based on novel concepts, combustion evalua-
tion of alternate fuels, and fundamental and analytical research.
Field application of techniques for many optimized conventional
fossil fuel combustion systems will be completed by June 1980, and
design criteria for alternate fuels and advanced systems will be de-
veloped and partially demonstrated by that time. Due to lags between
development and application of technology attributable to normal
scheduling and logistic considerations, it can be expected that field
application of concepts in the latter class will be accomplished be-
tween 1980 and 1985. In carrying out this program, a combination of
numerous contract, research grant, interagency, and in-house projects
are being undertaken.
Significant accomplishments of lERL-RTP's combustion control pro-
gram include:
0 Identification and characterization of stationary NO source
A
categories.
0 Collection of field test data and established state-of-the-art
combustion control for domestic and commercial heating systems.
0 Determination that flue gas recirculation is the most effective
21
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combustion technique for controlling NO emissions originating
-A
from thermal fixation of atmospheric nitrogen during the com-
bustion of clean fuels (natural gas and distillate oils) and
that staged combustion (often combined with low excess air)
is a very effective method for controlling NO emissions derived
J\
both from the thermal fixation of nitrogen in the combustion
air and from the conversion of nitrogen atoms chemically bound
in the fuel (heavy oils and coal).
0 Completion of the analysis of combustion control data for gas-
and oil-fired utility boilers. The application of combustion
modification has controlled NO emissions for these sources
.A
to a level of 100 to 200 ppra.
0 Extension of the application of combustion modification to
coal-fired utility boilers and reduced NO emissions by up to
J\
50 percent for this source category.
0 Initiation of mini-demonstration test programs for use of
Western coal in intermediate sized boilers.
0 Demonstration of staged combustion on a retrofitted 125 MW
tangential coal-fired utility boiler.
0 Determination of the effect of combustion variables on pollu-
tant emissions and equipment performance for 47 industrial
boilers.
0 Performance of pilot-scale research which showed that optimized
burner and furnace design can further reduce NO emission levels
J\
and should be applicable to a wide range of combustion sources.
Future R&D efforts are planned to demonstrate the beneficial re-
sults of this research on existing and new combustion sources in all
size categories. A potential problem in the application of combustion
modification to practical combustion systems is increased tubewall
corrosion. This problem is a subject of studies in the combustion mod-
ification program which will quantify the degree of corrosion and rec-
ommend practical solutions.
Long-term NO goals for oil- and gas-fired utility boilers are
A
50 to 90 ppm and, for coal-fired units, 100 ppm. Continued R&D efforts
22
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in combustion modification are directed at approaching these levels du-
ring the next 10 years. The 1985 goals could possibly entail the redesign
of some equipment types or require the use of novel combustion and/or
flue gas treatment schemes.
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 atmos-
pheric and pressurized FBC processes; development of environmental
objectives; publication of a best-available-technology manual, and pro-
vision of an overall preliminary environmental impact analysis.
0 FBC (Control Technology Development)—Development of laboratory
and bench scale multimedia control technology for SO , NO , total particu-
A A
lates, hydrocarbons, CO, and hazardous and other pollutants from FBC.
Development of treatment and final disposal techniques for spent
sorbent and ash. Demonstration of techniques at available pilot
facilities.
A major contractor will be utilized to conduct environmental assess-
ments of FBC systems and will also provide needed systems analysis and
program support for the FBC program. Comprehensive characterization
studies will be done on all available atmospheric and pressurized
systems. Supporting technical tasks will provide near-term preliminary
environmental assessment information, identify the effects of scale on
emissions from fluid bed units, provide sampling and analytical manuals,
consider the problem of special liquid and solid wastes, and evaluate
the applicability and problems associated with industrial-scale fluid
bed boilers.
Bench and pilot scale fluid bed studies will be continued to
characterize and develop existing and new control technology associated
with FBC applications. A large number of factors will be studied in-
cluding pretreatment of input streams (e.g., sorbent precalcination),
modification of design conditions, modification oT operating conditions,
and add-on control devices for gaseous, liquid, and solid streams.
23
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Air pollutant emissions and disposition of ash and spent sorbents will
be given special consideration. Engineering and small scale experi-
mental support will focus on optimization of SO control using a
A
calcium-based sorbent, alternate sorbents and means for SO control,
X
NO formation and control (especially for atmospheric systems), specific
/\
particulate control requirements, trace pollutants control, and means
for disposal and utilization of ash and spent sorbent.
lERL-RTP's program to evaluate FBC has produced the following
accomplishments:
0 Development of the environmental potential of atmospheric and
pressurized FBC (Westinghouse, Exxon, Argonne, National Coal
Board, PER).
0 Development of plans for a complete FBC environmental assess-
ment activity, and initiation of procurement action to obtain
an environmental assessment contractor.
0 Development of plans for comprehensive analysis of emissions
from all existing and planned FBC units. (Combustion Power
Co., BCURA, Battelle, Exxon).
0 Continued bench-scale investigation of air and solid emissions
control from FBC units, including sorbent regeneration (Argonne,
Exxon).
0 Completion of shakedown of the combustor of the 0.63 MW FBC
(coal) Miniplant, including 100- and 240-hour runs reaching
98 percent S02 removal and NO levels less than 25 percent of
/\
the New Source Performance Standard (NSPS) (Exxon).
0 Provision of substantial environmental support to ERDA's FBC
program.
COAL CLEANING
IERL-RTP subobjectives relating to coal cleaning are:
0 Physical/Chemical Coal Cleaning (Environmental Assessment)--Com-
plete 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 relation to these goals; publication of a manual
24
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of recommended practice for near-term goals; and modeling of the appli-
cability of coal cleaning on a national and regional basis.
0 Physical/Chemical Coal Cleaning (Control Technology Development)
A. Cleaning and Handling Facilities--Development and demonstra-
tion, where needed, of the best available technology for multimedia
pollution control from coal-cleaning plants, coal storage, and coal
transportation systems in coordination with the standards-setting
timetables.
B. 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 commer-
cialization of promising processes.
A major environmental assessment contractor will be responsible
for collecting information and conducting sampling and analysis programs,
This activity will provide the necessary multimedia data on coal trans-
portation and storage required to identify environmental problems and
efficiency of existing control techniques and to develop an overall
environmental assessment. Specific process assessments will be con-
ducted on the specific technologies that either have significant en-
vironmental problems or are the result of unsolicited or proprietary
proposals received during the year. Supporting tasks will consist of
task orders or contracts that will aid in technology transfer and pro-
vide quick and flexible technical and systems support to the program.
A major technology development contractor will investigate unit
operations, and processes for physical and chemical coal cleaning and
for pollution control from these processes will be evaluated. On-site
testing and evaluation of commercially used or developed equipment will
be made. Technology assessment studies will be performed and rec-
ommendations will be made on the development of new equipment and unit
operations. Emphasis will be placed on development of control tech-
nology and technology needed for EPA/DOI/ERDA funded demonstration
projects. Specific control system or disposal technique evaluation of
development will be undertaken on specific technologies which are
shown to have the potential for improved control or are the results of
25
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unsolicited or proprietary process proposals received during the course
of the year. Technological development of physical coal cleaning will
support development of new cleaning techniques and the demonstration of
a deep coal-cleaning plant with multiproduct stream capabilities.
Technological development of chemical coal cleaning will be conducted
through a series of contracts to identify new chemical approaches for
removal of sulfur, nitrogen, and other pollutants from coal; evalua-
tion of existing concepts or technology; and of operating bench-scale
testing programs and a versatile chemical cleaning technology facility.
Supporting technical studies will include contracts and task orders
to characterize coal residues, report on contaminants in coals, and
provide the necessary program and technical support required.
The physical/chemical coal-cleaning segment of lERL-RTP's fuels
program has produced:
0 Computerized data base for the characteristics of some 450
different U.S. coals.
0 Demonstration that existing technology used for removal of
inert matter from coal can also be used for removal of pyritic
sulfur.
0 Cost benefits for recovery of sulfur and energy values from
reject material from coal-cleaning processes.
0 Preliminary designs of plants for removing pyritic sulfur from
coal and for recovering sulfur and energy from the reject
material.
0 Bench-scale demonstration of effectiveness of pyrite leaching
as a means of removing pyritic sulfur from a variety of coals,
*
including those not amenable to physical desulfurization.
0 Identification of specific U.S. coals amenable to desulfuri-
zation by pyrite leaching.
0 Preliminary design of a facility to demonstrate pyrite leach-
ing at the pilot plant scale.
0 Independent review (currently being initiated) of pilot plant
designs to identify alternative concepts and equipment and
evaluate their technical merit.
0 Economic and engineering design analyses of commercial scale
chemical processes for extraction of pyritic sulfur from coal.
26
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SYNTHETIC FUELS
lERL-RTP's program on synthetic fuels includes the following sub-
objectives:
0 Synthetic Fuels from Coal (Environmental Assessment)— Characten'za-
tion 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 provi-
sion of an overall preliminary environmental impact analysis.
0 Synthetic Fuels from Coal (Control Technology Development)--De-
velopment, 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 assessment studies.
Major environmental assessment contractors will be utilized for
each synthetic fuel technology area: low-Btu gasification, high-Btu
gasification, and liquefaction. Each will be responsible in its own
area for providing the information and bases for assessing sources,
levels and fates of pollutants, and applicability of existing controls.
Environmental assessment of specific control processes will be conducted
on one or two selected proprietary processes, working with the developer.
Key pollutants system studies will be conducted on specific pollutants
that constitute major emissions or environmental effects. Technical
support tasks include work on input material characterization (which
is necessary input to the environmental assessment of any conversion
process) and test work on various conversion processes as products.
Major control technology contractors will be utilized in three
areas (pretreatment and waste management, converter output streams,
and product and byproducts) to evaluate, develop, and demonstrate en-
vironmental controls for synthetic fuels. The contractors will uti-
lize other organizations as necessary, but the major contractors will
be the focal points for accomplishing the required work of assessing
control applicability, determining effectiveness, developing controls,
integrating controls in processes, and other required activities.
27
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Basic and applied process evaluation and development will be obtained
via in-house facilities to fill information gaps, to verify informa-
tion generated by others, and to assess control potentials of systems.
The information may be used internally or to support major contractors,
depending on need. Specific control process development and evaluation
will be performed in areas of gas treatment, liquids treatment, solids
treatment, final disposal, and fugitive emissions. Supporting technical
studies are required for quick turnaround studies in areas which sud-
denly become important in program or Agency activities.
The synthetic fuels program has produced substantive results:
0 Analysis of over 100 coal samples from Eastern and Midwestern
coal sources (over 1,500 individual trace element analyses).
0 Identification of potential pollutant releases by several con-
version processes: Koppers-Totzek gasification, Synthane gas-
ification, Lurgi gasification, C02 acceptor gasification, BI-GAS
gasification, COED liquefaction, and SRC liquefaction.
0 Development and bench-scale demonstration of highly effective
desulfurization process for high-temperature gas stream.
0 Completion of an analysis of high- versus low-temperature
cleanup of gas streams, with emphasis on application of combined
cycles. (High-temperature cleanup was about 5 percent more
efficient.)
0 Completion of an analysis of problems and opportunities in
retrofitting industrial processes to utilize low-Btu gas. (In-
dustrial processes, representing a significant portion of ener-
gy use in industry, can be adapted to low-Btu gas use.)
0 Examination of commercial-scale gasification plants in five
foreign countries, and contracting for operational data and
pollutant-emission measurement on Lurgi units in several coun-
tries.
0 Sponsorship of a 1974 symposium that produced a comprehensive
report on the state-of-knowledge on environmental effects on
fuel conversion processes.
28
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0 Publication of a survey of potentially hazardous emissions from
the extraction and processing of coal and oil.
0 Initiation of a comprehensive, multimedia environmental assess-
ment program on shale oil recovery technology.
ADVANCED OIL PROCESSING
Advanced oil processing activities in which IERL-RTP is involved
include the following subobjectives:
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.
0 Advanced Oil Processing (Environmental Assessment)--Characteriza-
tion 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 time-
tables.
0 Advanced Oil Processing (Control Technology Development)—Development
and demonstration, where needed, of technologies for the removal of
sulfur, nitrogen, and potentially hazardous trace materials from petro-
leum, petroleum derivatives, and other liquid fuels. Development and
evaluation of the best practical control technologies for commercial
or near-commercial processes.
A major contractor will be used to provide comprehensive environ-
mental assessment of the various methods of utilizing petroleum residuals,
including the CAFB process. Supporting studies will provide for pre-
liminary environmental assessment of the CAFB process, environmental
assessment of solid and liquid waste problems, and residual oil dispo-
sition information.
A prime contractor will be utilized to design, construct, and
operate a small prototype unit (~20 MW) at a utility boiler site.
Supporting pilot and engineering projects will be'conducted to provide
needed background quick-response problem solving. This includes
29
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operation of batch and semicontinuous pilot systems, and engineering
work in such areas as sulfur removal systems, stone disposal and mar-
ket alternatives, advanced concepts such as pressurized CAFB, and other
control technology evaluation and development.
Other areas of advanced oil-processing work consist of: (1) basic
research on the thermodynamics, kinetics, and mechanisms involved in
sulfur and nitrogen release by catalyzed hydrogen attack and review of
the other applicable technology; and (2) development of existing de-
metallization catalytic hydrotreatment technology to maximize sulfur
and nitrogen removal and evaluation of USSR catalyst (cooperative U.S./
USSR effort).
lERL-RTP's program to evaluate advanced oil processing has pro-
duced:
0 Success in the pilot plant program with design work begun on
demonstration of CAFB process on utility boiler as an environ-
mentally sound fuel switching technique.
0 An inventory of potential pollutants in crude oils from specific
locations (domestic and foreign).
0 Determination of the fundamental characteristics of the reac-
tions involved in simultaneous hydrodesulfurization and denitri-
fication.
0 Identification of specific catalysts that tend to optimize de-
metallization of oils, and preliminary estimates of catalytic
deinstallization and desulfurization of specific Venezuelan,
Soviet, and Iranian oils.
OTHER SUPPORT
lERL-RTP's work in support of other subobjectives (wastes-as-fuel,
conservation, advanced energy conversion systems) includes the following:
0 Wastes-as-Fuel
- St. Louis/Union Electric Refuse Firing Demonstration and
Evaluation
- Fine Shredding Study
- Oil-Fired Boiler Study
- Utilization of Waste as Fossil Fuel Energy Substitutes
30
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- Wood Derived Fuel Program
- Environmental Assessment of Wastes-as-Fuel Processes
- Control Technology Development
0 Advanced Low-Emission/Energy Conserving Systems and Strategies
- EPA Van
- Heat and Emission Loss Prevention System (HELPS)
- Electrical Energy as a Substitute for Clean Fuels
- Fuel Distribution Pattern Flexibility
- Indoor Air Quality
0 Advanced Energy Conversion Technologies (Environmental Assess-
ment)
lERL-RTP's program in these support areas has produced:
Wastes-as-Fuel
0 Demonstration of technology for combined-firing of refuse in
coal-fired power plants and near-completion of environmental
evaluation. Initiation of studies to extend technology to
residual oil firing and use in stoker boilers.
0 Near-initiation of projects for detailed technology assessment
and environmental assessment of waste-to-fuel processes.
0 Control development/application for existing technologies.
0 Completion of evaluation of potential for waste-wood-derived
fuels.
Advanced Low-Emission/Energy Conserving Systems and Strategies
0 Completion of the construction of an advanced domestic energy
utilization 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.
0 Completion of a paper feasibility study indicating potential
for Heat and Emission Loss Prevention System (HELPS) employing
direct contact water heat exchanger to scrub fuel gas from
residential/commercial furnaces and bring furnace efficiency
from 80 to almost 97 percent.
31
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0 Definition of the potential for low environmental impact use of
electrical energy as a substitute for clean fuels which can go
a long way toward helping the United States meet the goals of
Project Independence.
0 Near-completion of a preliminary study on the extent to which
clean and dirty fuels can be switched to oil in reduction of
pollution.
0 Near-startup of a comprehensive program to evaluate indoor air
quality and its relationship to energy conservation.
Advanced Energy Conversion Technologies
0 Final negotiation of competitive contract system study to pro-
vide preliminary environmental assessment of advanced energy
conversion technologies such as magnetohydrodynamics (MHD).
Industrial Processes
The Industrial Processes program seeks to identify, develop, and
demonstrate cost-effective technologies for the abatement of multimedia
pollution associated with industrial processing and manufacturing.
The program involves the identification, characterization, and quantifi-
cation of polluting sources; the experimental modification of process
equipment, operations, raw materials, and products; and the application
of control processes, devices, or systems.
CHEMICAL PROCESSES
lERL-RTP's program toward controlling pollution from chemical
processes continues to receive emphasis. Previous work has been aimed
at developing particulate and odor removal technology for pulp and
paper mills, odor reduction technology for rendering plants, and con-
trols for asbestos emissions.
Chemical processes problem definition projects are on-going for
the following industries: fabricated metal products, petrochemicals,
inorganic chemicals, agricultural chemicals, asphalt roofing, glass
manufacture, asbestos materials fabrication, food products, combustion,
petroleum refineries and storage, construction, resources extraction,
and textiles.
Details of Chemical Processes projects appear later in this report.
32
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METALLURGICAL PROCESSES
Metallurgical industries, those that convert naturally occurring
or recycled metals into useful products, involve processing of ores or
scrap into pure metals or alloys, and the finishing of the metals into
consumer products. They include large integrated operations (such as
the iron and steel industry) as well as small one-owner operations (such
as iron foundries).
Because of the different nature of each metal industry and dif-
ferent technical and economic constraints confronting them, programs
to develop pollution control technology must be tailored to each in-
dustry segment. lERL-RTP's efforts in the metals industry began in
1969 with engineering studies of the major metal processes to define
both the extent of the problems and the effort required to develop
feasible control technology. Based on these engineering studies, a
program of research and development was undertaken directed at the
highest priority sources in the metallurgical industries.
This program, details of which appear later in this report, en-
compasses further definition and engineering studies, development of
new technology on laboratory and pilot scale, and full scale demonstra-
tions of control systems. Major emphasis has continued to be, for the
ferrous metals industries, on control of emissions from coke ovens,
from blast furnace cast houses, from sinter plant windboxes, from
basic oxygen process (BOP) charging, from iron foundry cupolas, and
from ferroalloy furnaces. Projects address the problems of control of
all effluent discharges, as well as fugitive emissions. In the nonfer-
rous metallurgy industries emphasis continues to be directed towards
the control of lean S02 streams from smelters, the control of fugitive
emissions, and an environmental evaluation of new metal-winning processes.
TRANSIENT OPERATION
IERL-RTP continues its efforts to achieve better control of emis-
sions during transient operations (process startups, shutdowns, up-
sets, or changes). IERL-RTP's program, described in detail later in
this report, involves the characterization of the- various industrial
emissions and measurement of the performance of the best current
33
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emissions control equipment during transient conditions. Reports from
IERL-RTF-monitored studies will help regulatory agencies decide
whether or not waivers from New Source Performance Standards should be
allowed for specific sources during periods of unsteady state process
operation. IERL-RTP studies will also identify any additional require-
ments for emissions control research and development.
PROCESS MEASUREMENTS
The major new thrust of Process Measurements work during 1975 was
in support of lERL-RTP's environmental assessment program, with the
objective of developing a conceptual approach to a coherent sampling
and analytic program suitable for application to the wide variety of
environmental assessment aspects of IERL-RTP's program. Concurrently,
work continued in the area of quality assurance: a specific quality
assurance program is now being developed for the Shawnee limestone
scrubber facility. Techniques, methodology, and instrumentation con-
tinued to be improved and expanded, with emphasis in the fields of fine
particulates and fugitive emissions.
Details of the Process Measurements program applicable to the
overall IERL-RTP program are described in a later section of this
report.
Program Operations
A majority of this report deals with details of programs relating
to the three IERL-RTP Divisions. The fourth IERL-RTP organizational
group, the Program Operations Office, serves as the technical support
staff and program administration support staff to the Office of the
Director, IERL-RTP, providing a vital function encompassing program
and project analysis, review, planning, and quality assurance.
SPECIAL STUDIES
Within the Program Operations Office, special studies are con-
ducted to provide a technical analysis and evaluation support function
to the Office of the Director. This function includes broad technical
assistance in program planning, guidance, and review; recommendations
to the Laboratory Director for program direction; and technical
evaluation of projects or programs as may be requested by the Labora-
tory Director or other Laboratory components. In addition, special
34
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studies provide other Laboratory components with statistical support
and consultation, computer application consultation, and management
of engineering services contracts.
During the past year, special studies have covered a wide range
of activities. Early in the year, reviews of three generic program
areas were prepared at the request of the. Laboratory Director. The
program areas reviewed included particulate technology, hazardous
pollutants, and NO and combustion research. The reviews provided
J\
management with a summary overview of program activities and addressed
possible enhancements to the programs. Special studies also included
detailed technical analyses of specific projects. These include chemi-
cal coal cleaning (TRW-Meyers Process), high-temperature gas clean-up
(CONSOL Process), and the catalytic oxidation (Cat-Ox) flue gas
desulfurization process. Relating to current Laboratory programs,
special studies have included the examination of subjects closely re-
lated to specific program areas but which are not directly a part of
those program areas. Such studies include a comparability analysis
of the economics and technical applicability of FGD processes, the im-
pact of clean fuels combustion on primary particulate emissions, and
maintaining a state-of-the-art knowledge of hazardous pollutants and
associated health effects. 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 significant impact upon control technology development.
The term "special studies" implies that certain investigations
will be made into areas of special interest or of special relevance to
the Laboratory's objectives. During the past year, special studies
have included several major projects in support of special Laboratory
interests. These include the development of an Environmental Assess-
ment Guideline Document, the creation of a computerized information
system on fine particle emissions from stationary sources, the de-
velopment of an Environmental Catalog of Industrial Processes (ECIP),
35
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and a feasibility study of developing a computerized information sys-
tem for data generated by IERL-RTP environmental assessment projects.
The Environmental Assessment Guideline Document is being produced
by a task force composed of Special Studies Staff personnel and one
representative from the Process Measurements Branch. This document
is intended to help establish conceptual guidelines for lERL-RTP's
environmental assessment projects. Related to these projects, the
feasibility of developing a computerized data system to centrally
store and manipulate the anticipated large volume of environmental
assessment data is being investigated.
The computerized Fine Particle Emissions Information System (FPEIS)
is being developed to replace the Fine Particle Inventory produced
by Midwest Research Institute in 1971. The FPEIS will contain data
from emissions testing of various stationary sources. Data to be
stored include particle size distributions; physical, chemical, and
biological analysis results; applied control technology design and
operating parameters; and the sampling and analytical techniques used
in collecting the data.
The ECIP presents a detailed description of selected industrial
processes identifying process inputs, the end products, the quantity
and type of waste streams to be expected, and the quantity and types
of utilities (water, energy, etc.) required by each process. To date,
24 chemical and metallurgical process industries have been incorporated
into the first edition of the catalog.
36
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ENERGY ASSESSMENT AND CONTROL
lERL-RTP's work in the area of energy assessment and control can be
subdivided 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 activities of IERL-RTP are directed to the
characterization, assessment, and control of the environmental impact of
energy conversion technologies. Programs are underway to study the multi-
media pollution problems associated with combustion processes (i.e., re-
lated to residential, commercial, industrial, and utility burners; fur-
naces and boilers; and stationary gas turbine and reciprocating 1C
engines) utilizing conventional fossil and alternate new fuels.
The major goals of these efforts are the development and demonstra-
tion of combustion modifications and control techniques or devices to
prevent or minimize pollution problems for these processes in a cost-
effective, energy-conserving, process-efficient, and environmentally
acceptable manner. Although the major emphasis of the program is on
investigation of technology for NO control, efforts are also underway
X
to reduce or eliminate other pollutants (such as unburned hydrocarbon,
carbon particulate, smoke, carbon monoxide, and various potentially
hazardous species) while simultaneously maximizing system efficiency by
optimizing system design and operating characteristics.
Combustion sources contribute about 98 percent of the total NO
J\
(nitrogen oxides) emissions from stationary sources. Some NO is formed
J\
in all fossil fuel combustion processes. Recent estimates of NO emissions
X
from major source categories in 1972 are shown in the following figure.
Control technology development studies to date indicate that combustion
modification is the primary near-term method of controlling NO emissions
A
from the combustion of fossil fuels.
IERL-RTP supported and directed efforts have shown that promising
combustion modification techniques include combustion with low excess
37
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INCINERATION 0.4%
NON-COMBUSTION 1.3%
GAS TURBINES 2.5%
INDUSTRIAL PROCESS HEATING 3.3%
COMMERCIAL & RESIDENTIAL
SPACE HEATING 7.1%
INDUSTRIAL
BOILERS
18.0%
RECIPROCATING
I.C. ENGINES
18.8%
SOURCE
UTILITY BOILERS
RECIPROCATING I.C. ENGINES
INDUSTRIAL BOILERS
COMMERCIAL & RESIDENTIAL SPACE HEATING
INDUSTRIAL PROCESS HEATING
GAS TURBINES
NON-COMBUSTION
INCINERATION
TOTAL
ESTIMATED NOx EMISSIONS
TONS/year
5,670,000
2,189,000
2,108,000
826,800
390,200
291,000
149,000
41,000
11,665,000
% OF TOTAL
48.6
18.8
18.0
7.1
3.3
2.5
1.3
0.4
100.0
Total NOX emitted in the U.S. from stationary sources (1972).
38
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air, recirculation of flue gas in the fuel/air mixture, staged combustion,
and burner/combustor system redesign.
The application of combustion modifications has controlled NO emis-
J\
sions from gas- and oil-fired utility boilers to a level of 150-250 ppm,
and reduced NO emissions from commercial coal-fired utility boilers by
A
up to 50 percent. Recent research has shown that changes in burner and
furnace design variables cause widely varying NO emission levels in all
X
boiler categories. Future R&D efforts are planned to demonstrate the
results of this research on existing and new combustion sources in all
size categories.
The results of this program, in the form of reports and design and
guideline manuals, provide information which will aid manufacturers and
users in producing and operating combustion equipment in a manner that
will be acceptable from an environmental and energy conservation point
of view. The information is also of benefit to environmental planners
and Federal, State, and local regulatory groups since it provides data
on the performance of equipment and the levels of control of the pollu-
tants under consideration when optimum combustion control methods are
applied.
For the purposes of this report, lERL-RTP's combustion modification
R&D program is classified under the headings: fundamental research,
fuels R&D, process R&D, and field testing and assessment.
Fundamental Research
lERL-RTP's fundamental research studies are providing an understand-
ing of the important phenomena in the formation and destruction of pollu-
tants during combustion. This understanding can then be used to optimize
existing combustion control techniques and to suggest other techniques
with even greater promise for control of pollutants. For purposes of
planning and discussion, the fundamental studies have been broadly grouped
into two categories: chemistry of pollutant formation and destruction,
and physical processes. Each category includes complementary experimental
and mathematical efforts.
39
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COMBUSTION CHEMISTRY
Combustion chemistry is a complex process involving both fuel decom-
position reactions and reactions of other flame species resulting in
formation and destruction of pollutant species. The pollutant species
of interest are oxides of nitrogen (NO ), carbon monoxide (CO), unburned
X
hydrocarbons (UHC), polycyclic organic matter (POM), carbon particulate,
fuel ash, and oxides of sulfur (SO ). The emphasis in this program is
A
on NO , with primary concern on nitric oxide (NO), the principal oxide
A
formed in combustion.
The combustion chemistry area can further be subdivided into two
areas: pollutant formation related to combustion conditions, and
pollutant formation related to fuel composition. These areas are reflect-
ed by the characterization of NO formed by fixation of atmospheric
A
nitrogen at high temperature in the combustion process as thermal NO ,
X
and that formed from oxidation of nitrogen chemically bound in solid and
liquid fossil fuels as fuel NO . For most fuels the total NO is
X X
composite formed by both mechanisms.
The thermal NO is thought to be formed by the Zeldovitch mechanism
A
and is dependent on both the temperature of the reaction and available
oxygen concentration. In the combustion reactions atomic oxygen is
formed in significant quantities which may exceed the equilibrium level
for a particular temperature by an order of magnitude or more. This
atomic oxygen combines with molecular nitrogen to form NO and atomic
nitrogen in a reaction which has a high activation energy, thereby
making the reaction rate highly temperature dependent. The atomic nitro-
gen produced can subsequently react with molecular oxygen to form NO.
To more completely define the important reactions and their rate
constants, a contract to study the reaction chemistry of pollutant forma-
tion has been underway with Exxon Research and Engineering for several
years. A complete survey of all possible fundamental chemical reactions
related to NO formation in combustion systems has been completed. Recom-
A
mendations of the best rate data, for those reactions which are mentioned
in the combustion literature, have been compiled and are now available.
40
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The remaining reactions, those not mentioned in the literature, have
been reviewed for potential importance in the NO formation and destruc-
A
tion process. These reactions were then turned over to Stanford Research
Institute, under grant to develop techniques for predicting rate data of
reactions not experimentally measured. Through the above prescribed
process, a complete library of rate data, either measured or estimated,
has been compiled for important NOV formation and destruction reactions,
A
and is now available as an EPA report.
Under an Exxon Research and Engineering contract, an experimental
study has been recently completed, utilizing a combustion apparatus in
which all conditions (including wall temperature) can be controlled pre-
cisely, to confirm the combustion chemistry and/or identify areas of
important uncertainty. The results are currently being evaluated.
Ultrasystems, Inc., has developed a rapid computerized technique to
allow evaluation of combustion kinetics of numerous simultaneous reac-
tions and to screen the reaction set to determine the important reactions.
At the present time the model incorporates only simplified flow fields:
the streamtube and the well-stirred reactor. By means of both an Ultra-
systems contract and in-house efforts, the chemistry of NO is being
A
investigated, and experimental results explained. These efforts have
uncovered the unexpected result that a large percentage of thermal NO
J\
appears to be formed by non-Zeldovitch reactions of the type:
CH + N2 -> HCN + N
In addition to Ultrasystems1 computer code, a computer program is current-
ly being developed at Aerotherm to analyze premixed flat flames, including
diffusional effects. Primary efforts have been directed at code develop-
ment. Plans call for using the code to explain combustion chemistry and
to interpret experimental data.
IERL-RTP in-house studies, and studies by others, have established
that the nitrogen chemically bound in most solid and liquid fossil fuels
can be converted to NO in the combustion process. It has been shown
A
that only about 50 percent of the bound nitrogen.is converted to NO; the
balance goes to other product(s), probably molecular nitrogen. The degree
41
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of conversion decreases as the available oxygen is decreased and can be
substantially reduced by a fuel-rich primary combustion zone. To optimize
control techniques (e.g., staged combustion), it is necessary to better
understand the chemistry of fuel nitrogen conversion and to establish
what conditions can reduce or eliminate NO formation.
/\
Rockwell International's Rocketdyne Division is working, under an
IERL-RTP contract, to establish the mechanism and chemistry of fuel nitro-
gen conversion to NO and other products. An experimental and analytical
,A
study was carried out to investigate the chemical mechanisms involved
in the conversion of fuel nitrogen to NO in combustion. The pyrolysis
J\
of fossil fuels and model fuel nitrogen compounds was investigated as
a function of temperature: it was observed that HCN was the major
nitrogen-containing pyrolysis product, and that the amount formed in-
creased with temperature. NH., was a minor product, and little if any Np
was formed. To investigate the combustion reactions of the pyrolysis
intermediates, premixed flat-flame burner experiments were conducted to
study in detail the conversion of HCN and NH, to NO in low-pressure
%5 X
CH.-Op-Ar flames. Based on the results of these studies, a mechanism
was proposed in which fuel NO forms via the reaction:
0 + NCO + NO + CO
This study is being continued to examine the decomposition of other
solid and liquid fuels, with emphasis on high-nitrogen synthetic fuels.
The flame studies are directed to further examination of the NCO mechanism
and to study of thermal and fuel NO reactions in CH.-Np-O^ flames.
COMBUSTION AERODYNAMICS
Although combustion chemistry is responsible for the formation and
destruction of pollutants, the actual conditions that exist in the flame
zone are a strong function of the physical processes of combustion. Most
practical combustors operate with diffusion flames where the fuel and
air are introduced separately and mixing depends on the manner of intro-
duction. Therefore, the flame zone is not a homogeneous composition,
and it is necessary to understand the role of combustion aerodynamics in
pollutant formation.
42
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United Technologies Research Center (UTRC), formerly United Aircraft
Research Laboratory, is under IERL-RTP contract to investigate the inter-
action of aerodynamics and combustion chemistry (in an idealized single-
burner combustor) as a function of fuel type and various inlet parameters.
The contract calls for detailed mapping of the local chemical composition,
temperature, velocity, and turbulence profiles. Preliminary testing on
gaseous fuels and liquid propane has been completed. Current testing is
employing a laser-doppler-velocimeter (LDV) which provides a measure of
the turbulence level as well as the mean velocity. The LDV results have
revealed that the ratio of the fluctuating component to the mean compo-
nent of velocity is on the order of 2.0; a value on the order of 0.1
was expected. This result has a major effect on the ability to measure
flow with in-situ probes, such as the impact static probe. The LDV shows
significantly more structure to the flow field than the impact static
probe. Preliminary results with an LDV in the newly constructed IERL-RTP
in-house aerodynamic test facility confirm the values measured at UTRC.
Further, tests are underway or planned for liquid propane, iso-octane,
and No. 2 fuel oil.
Because the chemical and physical effects of actual combustion are
closely related, it is necessary to have a method of tying these efforts
together and generalizing the results for a variety of systems. The tool
to be used is mathematical simulation of combustion by modeling. UTRC
has been working to improve a computer code for rigorous solution of the
Navier-Stokes flow equations. Major effort has been on improving the
turbulence model and comparison of model predictions with cold- and hot-
flow furnace data. Simple chemical kinetics have been used. Ultimately,
the kinetics and fluid-flow programs must be applied together to give a
realistic description of any practical system; however, more development
is needed before this synthesis can be accomplished.
The Jet Propulsion Laboratory (JPL) has entered into an interagency
agreement with IERL-RTP to establish the role of flame interactions in
multiple-burner systems. Although single-burner design criteria are
being determined in the fuels R&D work, the effects- of the interaction
43
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of adjacent flames in multiburner systems on the emission properties of
the system have not been defined previously. JPL has utilized a small-
scale versatile experimental apparatus to examine the interactions of
flow fields and associated thermal characteristics of the system for a
ring-type gas burner, a spud-type burner, and firing natural gas, liquid,
and solid fuels. Results of the study have shown the potential for
combustion zone interactions which significantly affect MO emission
/\
characteristics and will be valuable input to larger scale multiple-
burner research.
Another report published during 1975 was a NO control technique/
A
cost summary study by Aerotherm.
Fuels Research and Development
These studies are conducted on versatile experimental combustion
systems. The studies are designed to develop generalized combustion
control technology which is applicable to the control of NO and other
A
pollutant emissions from the combustion of conventional fuels, waste
fuels, and new fuels to be used in the future. Studies conducted to date
have been designed to develop combustion control technology for a specific
fuel through single-burner design criteria or combustion modification
techniques.
Contract studies (IGT) on natural gas fuel have been directed toward
establishing the relationship between combustion aerodynamics and air
pollutant emission characteristics of industrial gas burners. Three
types of burners were studied: a scaled-down utility power boiler burner,
a kiln burner, and a baffle burner for steel reheat furnaces. A final
report has been issued. On-going work is assessing combustion and emis-
sion characteristics of low-Btu gases.
Contract studies (Rocketdyne) on distillate oil fuel have developed
single-burner designs for minimum emissions and maximum fuel use effi-
ciency. These optimum burner designs produce up to 50 percent less NO
than the conventional design burners tested. Based on the results of
this study, a follow-on contract was negotiated to design and test an inte-
grated residential furnace system utilizing the optimum burner concepts
44
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t-.
I) I
Experimental system for combustion modification and future fuel studies.
-------
to obtain both low emissions and high efficiency. The initial experi-
mental phase has identified criteria for matching combustion chamber heat
removal and size to the optimum burner for both water- and air-cooled
furnaces. The resultant system will operate with no increase of CO or
UHC and a 75-percent reduction of NO relative to residential oil furnaces.
A
A prototype furnace system has been constructed, and its performance is
being evaluated. In addition, techniques for mass production of the
optimum head have been evaluated, and several stamped steel designs are
being tested.
Contract studies (Babcock and Wilcox) on coal fuel have been com-
pleted determining the effectiveness of NO control methods on coal-fired
A
utility boilers. The final report has been issued. The most effective
means of controlling NO emissions from a single-burner operational stand-
point is to control excess air, air preheat, and load simultaneously:
they are heavily interdependent. If load cannot be varied, control of
the combination of lower preheat and excess air is no more effective than
control of excess air alone. The results indicate that the concept of
staged combustion or delayed fuel/air mixing is the most effective com-
bustion modification technique for NO reduction. Acceptance of staged
A
combustion now requires field demonstration to establish the long-term
effect of operation with this modification. This is being pursued in
projects in the process R&D area.
Contract studies (International Flame Research Foundation) on funda-
mentals of burner design for coal, oil, and gas fuel combustion have
identified concepts for combining low emission and acceptable flame shape
with the same burner configuration. Exploration of triple concentric
burner concepts has shown the potential for achieving NO emissions of
X
200-300 ppm from a coal flame while maintaining a flame shape quite
similar to current practice. The study also included an examination of
residual oil and indicated that low levels of NO (about 100 ppm) can be
achieved.
As a result of the IFRF study findings, a contract was negotiated
with Ultrasystems, Inc., to define criteria for scale-up from the
46
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5 million Btu/hr size to practical size burners (125 million Btu/hr)
and to define the burner interactions which occur on a large scale. The
emphasis is on coal burners, although residual oil and combined coal/low-
Btu gas are also to be studied. The facility has been designed to allow
evaluation of the performance of single burners of capacity up to 125
million Btu/hr and multiple burners totaling 60 million Btu/hr in com-
bustion chambers simulating commercial practice as closely as possible.
The site has been selected, all local clearances received, and construc-
tion should be completed in mid-1976.
Another new study is expected to generate low emission burner con-
cepts for residual oil combustion in package boilers. The study consists
of an experimental phase (for the development of burner design concepts
applicable to package boiler geometry) and an application phase (for
testing a prototype burner in a field operating boiler). The results of
this study have shown important effects of oil type and atomizer con-
figuration. Although the goal of 100 ppm NO for residual oil has not
been reached, there is good reason to believe that it can be achieved
early in 1976. Concepts for improved application of staged combustion
and flue gas recirculation have also been identified.
A recently initiated pilot plant study is underway with Aerotherm.
The program is being conducted on a versatile 3 million Btu/hr experi-
mental furnace. The study will evaluate novel combustion concepts for
fossil and waste fuels. The program duration is 30 months.
A novel combustion concept being explored in this area is catalytic
combustion. A contract was let (Aerotherm) to establish catalyst charac-
teristics and system concepts for very low emission combustion of clean
conventional and alternate fuels. The effort also includes development
of scale-up criteria to allow application to a wide size range of future
practical equipment. Initial catalyst screening and design work is in
progress.
Past in-house work has led to significant understanding of the forma-
tion and control of fuel NO produced from chemically bound nitrogen.
The study has examined burner design, staged combustion, flue gas recir-
culation, and other techniques for control of both thermal and fuel NO
47
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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. In addition, combus-
tion modification techniques can be studied in a variety of applications.
The initial fuel class evaluated was alcohol fuels, which may be pro-
duced from coal gasification. They appear to have low emissions of NO
and favorable combustion characteristics relative to conventional clean
fossil fuels. The next class of fuels to be studied will be low-Btu
gas. A fuel gas generator has been designed and built by JPL under an
interagency agreement and will be delivered early in 1976. The key
variables will be CO/Hp/Np, fuel gas temperature, and NH3 content.
Process Research and Development
lERL-RTP's process research and development work involves the applica-
tion of optimum NO control technology to existing and new combustion
A
systems. The results of these studies provide the basis for the demon-
stration of combustion control technology. During the past year, interest
in projects in this area has continued to develop.
A study, completed under contract to IERL-RTP by Combustion Engi-
neering, developed detailed cost information for applying various com-
bustion modification techniques to new and existing tangentially coal-
fired utility boilers. The study substantiated the relatively low cost
of providing NO control through combustion modification. The second
J\
phase of this study, just completed, modified a 125-MW tangentially coal-
fired utility boiler with overfire air ports and evaluated and optimized
this control technique. Special emphasis was on the effects that this
technique had on unit performance and fireside corrosion. A final report
on this study has been written, and additional work with CE is evaluating
this technique with sub-bituminous coal in a separate program.
48
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225-KW gas turbine used for IERL-RTP in-house studies.
-------
C71
O
Precombustion chamber diesel (300 HP) for stationary engine controls development.
-------
Under an interagency agreement with IERL-RTP, TVA is evaluating
biased firing and will possibly investigate overfire air injection on a
125-MW wall-coal-fired utility boiler. This study also evaluated the
long term effects that these techniques have on unit performance and
fireside corrosion. The study is nearly complete.
A research grant (Aerospace Corp.) evaluated the applicability of
automotive-developed technology for control of NO and related emissions
/\
to stationary gas turbines and internal combustion engines. Additional-
ly, a research and development plan has been proposed for emission con-
trol studies based on the potential applicability of automotive-oriented
technology.
Aerospace is also compiling and correlating field test data collect-
ed by the Los Angeles Department of Water and Power during the past 3
years from some of their gas- and oil-fired utility boilers. (This is
also funded by an IERL-RTP grant.) In addition to correlating emission
data with combustion modification techniques, Aerospace will perform a
stability analysis to determine how a boiler can be redesigned to allow
more latitude when using combustion modification. They are also updat-
ing an emissions inventory for IERL-RTP.
A contract has recently been signed with Pratt and Whitney Aircraft
directed toward development of low NO gas turbine combustor technology.
J\
This study will focus primarily on dry control techniques because of
fuel economy and operational considerations and will specifically ad-
dress 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 NOX from fuel nitrogen.
IERL-RTP has initiated an in-house investigation of stationary
engine emissions control. Two engines have been installed at the RTP
laboratory: a gas turbine and a precombustion chamber diesel. Initial
studies indicate that CO, UHC, and fine particulate emissions are serious
problems in the gas turbine. An emulsion of fuel oil and water could
reduce NO significantly, but at the price of increased CO emissions.
/\
51
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No energy savings resulted from the use of the emulsion fuel. Studies
on the characteristics of the diesel engine are continuing.
A contract survey was initiated at the end of FY 74 to develop
information for an R&D program in industrial process combustion. This
survey will identify the most energy-intensive, nonsteam-raising indus-
trial combustion sources and determine the potential emissions and
energy benefit of an R&D program in this area.
Contracted studies (Ultrasystems, Inc.) related to combustion
modifications for package boilers are underway. These studies, concen-
trating on heavy-oil firing, have evaluated various burner parameters
considered significant in NO formation. They have emphasized staged
J\
combustion and flue gas recirculation. In the laboratory, NO reduc-
A
tions of about 40 percent have been achieved with staging, and flue gas
recirculation tests indicate that 30 to 40 percent reductions are possi-
ble. Initial application to field units is complete. In this applica-
tion phase, two package boilers were modified for flue gas recirculation
and staged combustion. The field results generally equaled or exceeded
the laboratory results. This study is complete and will be followed by
a second generation application to optimize the techniques.
Studies by KVB Engineering, Inc., are assessing the environmental
impact of converting industrial size boilers from bituminous to low-
sulfur sub-bituminous coal during a 30-month program.
Two other reports were published in 1975: one on a study by Mon-
santo Research Corporation of Western coal utilization and combustion
experience; the other on a study by M. W. Kellogg Co. on mixed and
waste fuel usage.
Field Testing and Assessment
Field testing and surveys include studies designed to determine
what can be done today to control NO emissions. This work is conduct-
J\
ed on commercial equipment and is performed generally by R&D organiza-
tions familiar with the specific combustion systems being studied, and
with the financial and technical assistance of manufacturers, users, and
trade associations. In addition to developing trends and providing
52
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directional recommendations for industry to use to minimize emissions
with today's technology, the work also defines where the R&D efforts
should be concentrated by developing emission factors as a function of
equipment type and size, and fuel consumed. The field testing and survey
studies are the initial efforts in the development of control technology
and are designed to provide the state-of-the-art in control of NO and
/\
combustible emissions from today's commercial combustion systems.
In November 1969, Exxon Research and Engineering completed the
"Systems Study of Nitrogen Oxide Control Methods for Stationary Sources"
for EPA, then known as the National Air Pollution Control Administration.
As a result of this study EPA's NO combustion control program was in-
/\
itiated in June 1970 when Exxon R&E began field-testing utility boilers.
As a result, it was found that NO emissions from gas- and oil-fired
/\
boilers could be reduced by 50 to 60 percent by using combustion modifi-
cation 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 secondary air ratio. Of these,
the first two were found to be most applicable and cost effective.
Combustion modification with coal-fired boilers was more difficult
because of operating problems and less success with NO reduction.
J\
Since the Exxon systems study identified coal-fired utility boilers as
the top ranking source of NO emissions from stationary sources, it was
A
decided to concentrate the efforts on this source. As a result, Exxon
was awarded a 2-year field test program which was completed in December
1973. These tests were very successful and showed that combustion modi-
fications have a good potential for reducing NO emissions from coal-
X
fired utility boilers without undesirable side effects. Reducing the
excess air level and staging combustion, as with gas- and oil-fired boil-
ers, resulted in significant NO reductions, averaging about 40 to 50
/\
percent for the boilers tested. The degree of reduction, as well as base-
line NO emission levels, varied with the design and size of coal-fired
J\
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. Also,
53
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by use of specially designed corrosion probes, comparison of accelerated
corrosion rates measured under "low NO operation" and those measured
X
under normal firing conditions did not reveal major differences. How-
ever, to confirm these results, longer term (1-month) corrosion tests
are being conducted with staged combustion and low excess air level
while firing high-sulfur, Eastern bituminous coal in a 125-MW utility
boiler.
The preliminary results of these tests demonstrate the need for
a more thorough investigation; new long-term (6- to 12-month) tests are
planned.
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, or gas and oil) fired 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.
In June 1973, a major field test program with industrial boilers
was initiated. KVB Engineering was awarded a contract to test approxi-
mately 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 emissions of NO , SO , HC, CO,
A X
smoke, and particulate mass. The tests were short-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 modifications,
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) toxic element emissions were meas-
ured. In addition to the final report, a manual will be published giv-
ing operating guidelines for these boilers.
On the basis of field measurements on industrial boilers, it appears
to be possible to reduce total NO^ emissions by 10 to 30 percent without
impairing boiler efficiency by reducing excess air, by staged combustion,
54
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and by flue gas recirculation. The excess air reduction is most attrac-
tive because, if properly applied, particulate emissions do not increase
as with other NOX reduction methods; combustion efficiency can also be
improved.
The residential and commercial boiler field tests were performed
by BatteHe-Columbus Laboratories under the joint sponsorship of the
American Petroleum Institute and IERL-RTP. The tests, with oil- and some
gas-fired equipment, were performed on boilers ranging from 80,000 to
about 20 million Btu/hr. The major conclusion was that combustible
emissions from residential equipment can be greatly reduced by proper
equipment servicing. By replacing old worn-out units, CO emissions were
reduced by more than 65 percent, HC emissions by 87 percent, filterable
particulate by 17 percent, and total particulate (filterable and condens-
able) by 33 percent. Tuning the burner by proper service methods
further reduced CO emissions for a total reduction of more than 81
percent. The Bacharach smoke number was reduced by 59 percent. This
strongly indicates that emissions from residential sources could be
reduced to an insignificant level by proper maintenance which would
identify units in need of replacement and by tuning the remainder. Sig-
nificant NO reductions should result from burner redesign programs
A
described elsewhere in this report.
The major results with commercial boilers were that emissions are
mainly affected by boiler and/or burner design and by fuel type. Also,
it was found that, for commercial boilers operating at steady state
conditions, Bacharach smoke numbers showed consistent trends in relation-
ship to filterable particulate when firing different oil in the same
boiler. Manuals giving operational guidelines for this equipment are
now available for servicemen and residential furnace manufacturers.
The manuals give instructions for the ways of reducing emissions, either
in servicing or in design of new equipment.
A contract has been negotiated with KVB for a field test study of
industrial process equipment (e.g., furnaces, kilns, ovens, and driers),
55
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stationary gas turbines, and stationary internal combustion engines.
Some of these types of equipment are significant sources of NO emis-
/\
sions and have the potential for emission reduction via combustion
modification.
In-house studies closely related to the field testing are being
conducted in emission characterization and design evaluation for com-
mercial combustion systems. The objective of this work is to investi-
gate, under controlled laboratory conditions, the emission performance
of existing/prototype commercial combustion systems and components and
to evaluate effects of new burner/combustor designs and modifications
on the emission and energy efficiency performance. Two different
equipment systems have been baselined; that is, the best conditions
for minimum emissions with unaltered equipment have been established.
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 Total emulsifier and the
Cottell ultrasonic emulsifier. 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. The Gotten device provided significant reductions
in smoke number and particulate emissions. Neither emulsifier reduced
NO emissions significantly when firing residual oil (which has a
X
high fuel nitrogen content); however, a significant NO reduction was
J\
observed when distillate oil was fired. Some emulsion devices may
have a small potential for energy conservation by permitting boiler
operation 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
A fuel injection equipment program has been carried out to determine
56
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Scotch marine boiler (60 HP) for emission control equipment evaluation.
-------
emission characteristics from air, high pressure, and sonic atomiza-
tion of No. 6 residual oil.
In addition to the field testing activities, a major contract
effort is being developed for a multimedia environmental assessment
and systems analysis of NO combustion modification control techniques.
J\
This effort is to determine the technical soundness and environmental
acceptability of these control methods, and to ensure that any defici-
encies or potential problems are identified and corrected in a timely
fashion, before the technologies are adopted commercially. A contract
is expected to be awarded early in 1976.
A project has been initiated 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 lERL-RTP's
in-house combustion research laboratory. This project is to provide
for: comprehensive analyses of emissions from FBC; testing of alterna-
tive sampling and analytical procedures for FBC; and investigation of
alternative add-on environmental control devices for FBC.
FUEL PROCESSES
The fuel processes program of IERL-RTP is primarily concerned
with three major aspects of environmental control:
0 Assessment of, and development of control technology for,
all environmental discharges associated with processes for the
cleaning of fossil fuels.
0 Analysis of the emerging coal-based synthetic fuel industry in
the United States, assessment of its environmental problems, and
development of appropriate control technology.
0 Direct development of technology for the selective chemical and
physical cleaning of fossil fuels for environmental control.
IERL-RTP is concerned with the availability of fossil fuels used
for combustion purposes—coal, oil, and gas. All aspects of synthetic
fuels are being considered including high-Btu gasification, low-Btu
gasification, and liquefaction. In addition, IERL-RTP is continuing to
carry out a successful program in the utilization of refuse as fuel.
58
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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 multi-
faceted effort toward this goal is currently underway at IERL-RTP.
A report issued as a result of an extensive literature survey pre-
sents and analyzes data on the sulfur, nitrogen, and other potential pol-
lutants (e.g., lead, cadmium, beryllium, mercury) found in coals consumed
in the United States. Data are characterized according to the location of
the raw coal and are analyzed for geographic effects on composition.
Recognizing that existing data are inadequate for many constit-
uents, both from the quantity available and from their accuracy,
lERL-RTP's interest is both in developing analytical techniques for
trace elements and in the analyses themselves. Techniques being
utilized include neutron activation, X-ray fluorescence., atomic absorp-
tion, ion specific electrode, direct reading optical emissions, and
photographic optical emission. Analyses have been completed for coal
samples and 23 trace elements with results published in a report.
Additional analyses are continuing. Since the form in which a con-
stituent is present in coal may affect its pollution potential, an
effort is also underway to define the nature and composition of
coal's mineral matter. Areas being investigated include the mineral-
ogical affinities of trace elements in coal, mineral distribution in
coal, and effects of high and low temperature on coal's mineral matter.
Additional studies have been initiated to determine the potential
pollutants in coal that are organically combined, the chemistry of
coal pollutants and removal technology, and the pollutants/byproduct
recovery of coal refuse. These studies are providing information which
will be helpful in determining the quantity and fate of potential pol-
lutants in coal utilization, processing, or conversion to clean coal.
Since coal is utilized not only in raw form, but'is also processed
or converted into more conveniently useful or environmentally sound
59
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forms, it is necessary to know more about coals than their natural com-
position.
An effort has been initiated to determine the fate of potential
pollutants in coal processing and conversion (to liquid and gas) sys-
tems. At present, the major effort is aimed at collecting and analy-
zing all pertinent information on the effluent and process streams
from coal treatment and/or conversion processes that exist or are
being developed by either the Government or private industry. Sev-
eral reports issued on various processes provide preliminary environ-
mental evaluation. Additionally, a major symposium, the second of its
type, v/as sponsored by IERL-RTP and held in Hollywood, Fla., in
December 1975. This symposium, "Environmental Aspects of Fuel Conver-
sion Technology, II," provided an overview of the state-of-the-art
and was attended by a broad spectrum of attendees from industry,
Government, and research organizations.
Previous and current efforts to define raw coal composition pro-
vide an initial list of potential pollutants. Each operation to which
the coal is subjected must then be evaluated to determine the fate of
these potential pollutants; also, the process must be evaluated to
determine if any new potential pollutants have been generated as a
result of the process.
In addition to the trace elements that are potential pollutants in
air, water, and solid waste, many others must be considered. For air,
these include SO , NO , total suspended particulates, fine particulates,
X X
CO, HC, toxic pollutants, odor, and thermal pollutants. For water they
include dissolved oxygen, biological and chemical oxygen demand, total
organic carbon, total dissolved salts, oils, mercaptans, phenols, pH,
color, and thermal pollutants. For solid waste, composition and quan-
tity are the concerns. Other environmental considerations include
temporary or permanent land use, occupational safety and health, com-
munity noise, historical and cultural considerations, and the endangering
of animal species and ecosystems.
60
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Since currently available information is inadequate for most coal
constituents, an effort has been initiated to sample and analyze coal
processing effluent streams to determine the fate of the potential
pollutants. The primary concern is that the treatment and/or conver-
sion process that generates the clean fuel does not itself become a
major pollution source, as reflected in the following hypothetical
simplified gasification flow diagram. Having quantified the potential
problems, an evaluation will be made to determine the potential prob-
lems that require controls. Existing techniques for controls will
then be evaluated and utilized where applicable and new controls will
be developed and demonstrated as necessary to permit the coal treat-
ment and/or process for producing a clean fuel to be commercialized
with minimum delay.
COAL CLEANING
One solution to the problem of reducing the pollutants produced
by combustion is to burn a clean, low-polluting fuel. For example, SO
X
emissions can be reduced by burning low sulfur content fuels. Unfortu-
nately, abundant domestic supplies of low sulfur fuels are limited in
the coal regions of the Eastern United States which supply most of the
combustion coals. The largest low sulfur coal reserves are in the
Western United States, far from major utilization points, and relative-
ly undeveloped.
An alternative to a ready supply of clean fuel is the burning of
fuels that have been cleaned sufficiently to meet established pollution
criteria. Coal cleaning could provide relief in areas of severe SO
J\
pollution where other control techniques, such as flue gas cleaning,
are impractical.
lERL-RTP's coal cleaning program includes two approaches—physical
and chemical cleaning of coal. Previous IERL-RTP activities under the
program have included washability and coal availability studies, opti-
mization of physical coal cleaning techniques that have the potential
61
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ro
I COAl
1 MINE
*
Icoo
•
TARS AND .
OILS "*""
\~*\ PREPARATION |~^| STORAGE |~*"| PRETREATMENT |"**| GASIFICATION |
1 |
1
UTILIZATION •«— ^"JJ10 --*•
•
i. |
DISPOSAL
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-*M SHIM 1 >| COOLING 1— >| HURIHCAIION 1 >| MblHANAIlUN 1 M COMPRESSION |~ CNQ ' *"
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NOTE: NOT ALL STREAMS ARE SHOWN.
SULFUR _^ TAILGAS
ECOVERY "*" TREATMENT
Hypothetical simplified gasification flow diagram.
-------
for significantly reducing the sulfur levels in coal, and the develop-
ment of a two-stage froth flotation process for removing pyritic
sulfur from fine sized coal.
The program currently includes the development and demonstration
of chemical processes for the removal of sulfur and other pollutants
from both coal and residual oils, and the review of processes being
developed by others to ensure that they are environmentally sound.
Technology Development
Physical/Mechanical Coal Cleaning—Removing ash from coal mechani-
cally (by physical separation) is not new to the coal industry: it is
used both to maintain Btu levels of coal used for combustion and to pre-
pare metallurgical grade coal.
lERL-RTP's program of optimizing coal desulfurization recognizes
that deep-cleaning methods (used to maximize pyrite separation) involve
a significant increase in the cost of coal. However, since a very
significant portion of the cost increase is due to the loss of coal in
the deep-coal cleaning rejects, subsequent recovery of Btu, sulfur, and
metal oxide values from rejects would tend to reduce or eliminate this
economic barrier to deep-coal cleaning.
The Laboratory's extramural coal-cleaning program includes specific
investigations to fill in existing information gaps. The program is
aimed toward the eventual demonstration of a prototype coal-cleaning
plant.
Pyritic sulfur and ash washability studies consist of separating
material based on specific gravity differences between coal and its
various impurities. These evaluations were performed by the U.S. Bureau
of Mines (USBM), Commercial Testing and Engineering Co. (CTE), and the
Illinois State Geological Survey (ISGS). The USBM and ISGS are still
actively engaged in these evaluations. The ISGS completely evaluated
all physical and chemical characteristics of Illinois coals. This
effort, by far the most broadbased cleaning study that has been performed
on available coals, will probably be continued until all available mines
have been evaluated. Additional effort is being made" to identify trace
element levels and their fate during coal cleaning.
63
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Other ongoing major projects being conducted by USBM (with IERL-
RTP funding and direction) concern: (1) control of cleaning plant
black water, (2) study of surface phenomena and coal dewatering, (3)
absorption/desorption reactions in coal pyrite flotation, (4) coal
preparation with stack gas scrubbing, (5) specifications for pyrite
flotation circuits, (6) coal preparation pilot plant facility, (7)
magnet type/small media magnetic recovery circuits, (8) instrumentation
of coal preparation plants, (9) magnetic separation of pyrite from coal,
and (10) computer simulation.
The USBM has investigated the operating characteristics and per-
formance of various other types of coal-cleaning methods such as froth
flotation, hydrocyclones, dense media cyclones, electrokinetics, and
agglomoseparation. Major results have been the development of the
two-stage froth flotation concept and the construction of a demonstration
unit for obtaining pyrite separation from fine sized coal (the lack of a
technique to desulfurize fine coal has been a major gap in the area of
physical coal cleaning).
Based on prior studies of operating parameters and performance of
various coal-cleaning techniques, coal characterization, and pilot plant
design, the USBM is now developing a computer model to predict coal-
cleaning plant configuration and performance. To date, major segments of
the model have been completed and are operational. Current studies will
provide additionally required model components such as crushing, sizing/
screening, and froth flotation.
An assessment has been completed of the use of a high sulfur com-
bustor, capable of burning coal-cleaning plant refuse and gob pile re-
jects which are characterized by high ash and high sulfur content. This
study also assessed ignifluid boiler technology, pulverized coal boiler
technology, and the flue gas cleaning process in comparison to the high
sulfur combustion preliminary design.
Studies are currently underway for the environmental assessment of
coal-cleaning techniques and evaluation of methods and commercial equip-
ment for physical coal cleaning. The scope of these efforts includes
64
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physical coal-cleaning techniques for pyrite removal from fine coal,
coal sulfur reduction potential, coal-cleaning equipment performance,
and evaluation of overall final data. Further equipment and plant
system data will be generated through field testing. There will also
be evaluations of dewatering and coal handling techniques, and of
coal preparation requirements for synthetic fuel processes. The use
of coal-cleaning plant products will be studied, and engineering trade-
off studies are planned for coal preparation equipment processes.
A Process Design Manual for physical coal cleaning is near com-
pletion.
Chemical Coal Cleaning—lERL-RTP's active efforts in chemical
coal cleaning began with the development of a processing technique
initially shown to be feasible by the Systems Group of TRW, Inc. This
technique, the Meyers' process, involves chemically extracting pyritic
sulfur from coal. It is illustrated by the chemical desulfurization
flow scheme below. Industrial applications of this particular process
include processing coal into clean combustible fuel and processing
waste coal from sludge ponds. lERL-RTP's objectives for this process
have included the realization of a cost equal to or less than the
cost of flue gas desulfurization (or other clean fuel) processes, and
the reduction of pollutant emissions as follows:
0 Meeting or exceeding New Source Performance Standards (or 95
percent removal) for pyritic sulfur.
0 Simultaneous removal of trace metals.
0 Minimal environmental impact of water and solid waste.
In the past year, a pilot plant construction plan has been modified
to provide a 250-pound-per-hour reactor test unit and to evaluate the
feasibility of testing other coal-cleaning processes.
A survey of the applicability of chemical desulfurization of coal
technology to 35 different U.S. coals has been completed and results
published. This initial survey confirmed the general applicability of
the technology.
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en
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TRW Meyers process for coal desulfurization.
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IERL-RTP has initiated a program with Battelle to conduct an
environmental analysis of their hydrothermal coal process, and an
evaluation of the combustion characteristics of the product coal.
Also, some supporting analytical measurements studies have been started
to characterize the spent leachant from the process. The objectives
of these studies are to determine the environmental effects and dis-
charges produced by the process and to determine the environmental
impact of the combustion of the process product.
The Laboratory is also supporting work to develop a method for
the chemical hydrotreatment (flash desulfurization) of coal to produce
a clean fuel; this work involves feasibility testing and optimizing
concepts as identified by the Institute of Gas Technology.
IERL-RTP is in the process of evaluating new chemical coal-cleaning
processes to be considered for possible future support. Emphasis is
being placed on examination of those processes that promise to remove
both pyritic and organic sulfur from coal.
SYNTHETIC FUELS
The Laboratory is very much involved in the emerging industry of
coal conversion or synthetic fuels. There is a great need for ongoing
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 perplexing questions concerning the environ-
mental 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 technol-
ogy and pollution determination. The degree of control of discharges
from existing control techniques has not been quantified. IERL-RTP's
programs for environmental assessment and control technology development
are currently addressing these problems.
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Environmental Assessment
The goal of defining a synthetic fuel industry that is environmentally
sound is being approached through:
° The use of existing multimedia environmental source assessments.
0 Identification of information gaps and needs, by conducting
in-house studies, updating environmental source assessments,
and exchanging information with those involved in health effects
and control technology development.
0 The integration of all data into a total environmental assessment.
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 gasifi-
cation processes and specific listings of probable pollutants from
processes such as the Hygas process. Two more trace element reports are
in preparation. Individual reports 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 conver-
sion processes. This will include a complete environmental assessment of
emissions and effects. An in-house gas cleaning test rig is planned, and
new data acquisition capability is being developed.
Low-Btu Gasification—The Laboratory continues to place emphasis on
the various aspects of low-Btu fuel, including its near-term use in
various industrial commercial and utility applications. Although some
commercial gasification processes exist to produce low-Btu fuel from coal,
several questions need to be asked concerning their application: Do low-
Btu gas characteristics apply to this situation? Are space requirements
met? What is its reliability? What is its load-varying capability? Is
it economical? What are the environmental considerations? What are the
offsite requirements? Is sufficient water available? In general, is it
a viable alternative?
These are some of the questions for which quantified answers are being
sought in determining the near-term impact that existing processes could
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have on the energy supply and in evaluating the potential problems that
must be solved to accomplish their environmentally sound use in existing
complexes.
For new installations, a study of combined-cycle plants utilizing
coal gasification is in progress. It is evaluating the total environmental
impact of coal gasification (low-Btu) with combined-cycle electrical
power generation process. Major considerations will be the evaluation of
the alternatives of high- vs low-temperature cleanup of raw fuel gas and
NO control.
A
Two fuel gas generator types are being considered: one represents
a high-temperature gas with little or no condensibles in the gas; the
other, a moderate-temperature gas with condensible constituents. The
study will then evaluate the most efficient and economical means of
utilizing each gas in a combined-cycle operation considering such factors
as capital cost, energy usage efficiency, generated electricity cost,
environmental impact, and impact on energy supplies for given time periods.
Low-Btu gasification has been the subject of various reports: the
Koppers-Totzek, Winkler, and U-Gas concepts; and one concerning industrial
utilization of low-Btu gasification. Planned programs for the very near
future include an extensive data acquisition and evaluation program, and
an environmental source assessment of overseas commercial installations
possibly including gasification plants in South Africa, Poland, and
Yugoslavia.
An in-house gasification and gas cleanup test rig will enable IERL-
RTP to conduct basic studies to identify pollutants, the applicability
of generic types of controls, and thermal discharge problems.
An earlier figure diagrams a hypothetical simplified gasification
system.
Liquefaction—The conversion of coal to a clean combustible oil prod-
uct is another viable option being closely studied by IERL-RTP.
A recently completed study provides a complete analysis of the sulfur
and nitrogen balances in the Solvent Refined Coal (SRC) process. Ongoing
projects involved with this process include:
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0 An examination of the design possibilities for producing clean
gas and other clean liquids from the SRC process.
0 Preparation of an environmental test plan for the SRC pilot plant.
Reports have been issued on individual liquefaction processes such as
SRC, COED, and H-Coal. New programs will be initiated concerning data
acquisition and environmental assessment of specific control processes.
An in-house coal hydrogenation test rig will be forthcoming to pro-
vide much needed data on this phase of liquefaction. Also, a program of
synthetic liquid denitrification has been initiated.
Control Technology Development
The objectives for the development of synthetic fuel control tech-
nology include evaluation of the applicability of existing methods and
the development of new methods for abating both synthetic fuel process
environmental problems and also problems resulting from the utilization
of products and byproducts from synthetic fuel processes. Field testing
and in-house experimental facilities will provide evaluation of existing
and new technology.
Activity and current work areas have already produced some results
which are most helpful in developing planned extensive new programs and
control technology development. A design of an in-house laboratory scale
and environmental assessment control testing unit for coal-derived liquids
(previously referred to as a coal hydrogenation facility) is near com-
pletion. This facility will test systems which produce liquids from
coals, such as solvent extraction and hydro-liquefaction.
Another facility to implement a gas cleaning test program has been
designed. This gasifier will help IERL-RTP define the applicability and
performance of fuel gas cleaning and other coal processes, and to determine
the fate of pollutants generated by the gasifier or cleanup process.
The Consolidation Coal Company has produced a report for IERL-RTP on a
fluidized-dolomite-bed, a fuel gas cleanup system which comes under the
category of new/novel control method development. MIT is preparing a
report on liquid fuel, simultaneous hydrodesulfurization/hydrodenitrifica-
tion describing experimental studies which they have been carrying out for
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IERL-RTP. Other reports, dealing with existing control technology evalua-
tion, discuss hydrocarbon emission control methods, refinery control
methods, and environmental problem definition. Another report, con-
cerned with control technology associated with the Solvent Refined Coal
clean fuel process, is also being prepared.
A broad program of future activities in control technology develop-
ment in the synthetic fuel area is planned. It includes:
0 Control Technology Evaluation—
Simultaneous hydrodesulfurization/hydrodenitrification of
synthetic liquids.
Hydrodenitrification of synthetic liquids.
General program support for systems analyses and reviews.
Technical/economic studies of control methods and applications.
New control process evaluation.
Test criteria specification for control process examination.
0 New/Novel Control Method Development--
Pilot plant studies of dolomite cleanup system.
New gas treatment process development.
New liquid treatment process development.
New solid waste treatment process development.
Final disposal technique development.
Fugitive emission control technique development.
Prime contractors' control development areas.
0 Existing Control Method Field Testing--
Control technology evaluation in foreign conversion facilities.
Interagency cooperation with ERDA on field testing of existing
control systems.
Prime contractors' field testing for existing control techniques,
0 Field Demonstration of Control Methods—
Interagency cooperation with ERDA on field demonstration of
control systems.
Prime contractors' field demonstration of control techniques.
0 In-House Experimental Studies—
Construction/operation of in-house acid gas cleanup facility.
71
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Construction/operation of an in-house coal hydrogenation control
unit.
Construction/operation of an in-house oil treatment facility
for denitrification.
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 sur-
vey 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 proces-
sing and utilization.
OIL TREATMENT/PROCESSING
lERL-RTP's oil treatment/processing program concerns itself with four
areas of interest: demetallization, desulfurization, denitrification, and
effluent controls.
Demetallization
Much of the U.S. oil available for fuel is high-sulfur, high-metals
content residual oil. Currently, residual oil cannot be desulfurized
economically to meet environmental requirements because metals in the oil
poison the desulfurization catalyst. Since vanadium and nickel are two
of the major poisons, a program is underway to develop a low-cost method
for removing them prior to conventional desulfurization. The program is
evaluating various scavenger and catalyst combinations in a continuous
downflow reactor. The residual oils being used in the investigation are
vacuum bottoms with 3 to 3.5 percent sulfur and 400 to 1000 ppm total
vanadium and nickel. Successful completion of this project will result
in an economic and clean fuel for use in existing large installations,
permitting higher premium fuels to be used by smaller area sources.
Desulfurization
Reduction of the sulfur content of liquid fuels has traditionally
involved the use of fuel desulfurization with hydrogen. Such hydrodesul-
furization involves a large capital investment cost that generally limits
its use to major refineries. Technologies for nonhydrogen desulfurization
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of liquid fuels, which could apply to all sizes of refineries as well as
to smaller industrial consumers of high-sulfur liquid fuels, would have
significant potential for development into commercial fuel desulfurization
availability. Such a technology, being developed by others, is currently
being evaluated by IERL-RTP to determine its potential for the control of
sulfur (and other pollutants) in a spectrum of fuels encompassing gasoline,
distillate fuels, shale oil, crude oil, and residual oil.
Denitrification
For high-nitrogen content oils, research is underway to investigate
the kinetics of simultaneous hydrodesulfurization and hydrodenitrification
of liquid fuels. These reactions are being studied to determine the con-
ditions at which they are competitive and those at which they may be aiding
each other. Results of this type of work are aimed at long-term applica-
tions and may be most useful in producing clean fuels from liquids derived
from coal or oil shale.
Effluent Controls
In addition to studying techniques for pretreating oils for the control
of pollutant emissions, IERL-RTP is currently studying the types of control
devices being used to control emissions from all phases of the liquid fuel
industry. These phases include crude oil production, field treatment,
transportation, refining, and product marketing and distribution. The
nature of emissions from all of these industrial stages is being evaluated.
Existing and emerging emission control methods will be evaluated to determine
their potential for meeting industry's control needs. Gaps in control tech-
nology requiring the development of new methods will be identified.
Fossil Fuels—Gas
Natural gas is a clean fuel, compared to coal and oil. Since the
potential gas demand is so much greater than its supply (or total resource
base), it is important for the long-run to ensure adequate supplies of other
clean fuels in order that the premium gas may be used most effectively.
An alternative to natural gas is a substitute natural gas to increase
the supplies of gas. This possibility is being investigated by various
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groups; however, a main concern is the environmental aspects of the produc-
tion process itself, described in more detail in the "Fossil Fuels—Coal"
portion of this report.
Fossil Fuels—Other
IERL-RTP has completed the environmental test portion of a demonstra-
tion to effectively and economically reduce hydrocarbon emissions from
small to medium size gasoline bulk storage/loading terminals. The figure
below shows an installation for controlling hydrocarbon emissions from a
gasoline bulk storage/loading terminal.
Waste as a Fuel
Using refuse as a fuel can help solve the municipal waste disposal
problem, reduce air pollution, and provide at least a partial response to
the current energy crisis. Burning refuse (instead of high-sulfur fossil
fuels) in utility grade boilers can reduce sulfur dioxide (S02) emissions,
and selling the generated steam or electric power can help lower the costs
of waste disposal.
A demonstration of the feasibility of burning refuse as a supplementary
fuel in utility boilers is underway at St. Louis, Missouri. It is being
funded cooperatively by the City of St. Louis, Union Electric Company, and
two EPA organizations, IERL-RTP and the Resource Recovery Division. Refuse
processing and firing facilities are operational and testing is near com-
pletion. It is pictured below.
Refuse is processed, including the shredding and classification of
municipal waste, at a 300-ton/day processing plant. The refuse is stored
on-site and is later transported 18 miles by truck to Union Electric's
Meramec power plant where it is burned to generate electricity. Facilities
at the power plant include a receiving building, surge silo, and pneumatic
transfer equipment. At the power plant, the shredded refuse is pneumatically
conveyed 600 feet from the surge silo to a 125-MW corner-fired, pulverized-
coal-burning boiler where it is burned to provide about 10 percent of
the boiler's total heat input. Particulate emissions from the boiler are
controlled by an electrostatic precipitator (ESP).
To date, over 20,000 tons of refuse have been processed and fired.
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LOW-TEMPERATURE
THERMAL OXIDIZER
INSTRUMENTATION CONTROLS
PROPANE '
STORAGE
VAPOR
SAVER
Controlling hydrocarbon emissions from gasoline bulk storage/loading terminal.
75
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en
The City of St. Louis municipal incinerator demonstrates recycling of household solid waste.
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Early problems with jamming of the pneumatic feeder valves at the firing
site have been resolved by the installation of an air classification system
at the processing plant to remove heavy material from the processed solid
waste. Removal of about 16 percent of the heavier (mostly nonburnable)
wastes has also reduced the formerly large amount of boiler residue. A
ferrous metal recovery system, installed at the same time as the air
classifier, reclaims ferrous scrap which is sold for about $20/ton. The
most persistent problem has been pipe erosion in the pneumatic transfer
system at the power plant. New pipe elbow materials which promise to re-
duce pipe maintenance are being experimentally evaluated.
Preliminary pollution testing indicates that refuse firing does
not appreciably affect the emission of gaseous pollutants, but that ESP
performance (hence, particulate emissions) is adversely affected. Ad-
ditional pollution testing has now been completed, and an evaluation of
the results is underway.
ADVANCED PROCESSES
Fluidized-Bed Combustion
Within the area of fluidized-bed combustion, lERL-RTP's current efforts
are in two distinct areas: fluidized-bed combustion of coal and fluidized-
bed gasification/desulfurization of residual fuel oil.
FLUIDIZED-BED COMBUSTION OF COAL
lERL-RTP's program goal in the area of fluidized-bed combustion (FBC)
of coal is to develop all necessary environmental data over the full range
of variables for all variations of the FBC process. It is desired to ob-
tain these data on a suitable experimental scale and on a time schedule
compatible with the development schedule envisioned in the national FBC
development effort.
During 1975, lERL-RTP's on-going FBC program was expanded toward
the objective of complete environmental characterization of the process.
Development was initiated of a major contract for complete environ-
mental assessment of the FBC process. This environmental assessment will
include: identification of current process/environmental background;
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comprehensive analysis of emissions from operating units; development of
environmental objectives for the process; assessment of control technol-
ogy for use with the process; analysis of the environmental impact of the
process; and development of a program designed to obtain missing data and
enable achievement of the environmental objectives. This contract will
be awarded early in 1976.
In the meantime, GCA/Technology Division is carrying out a prelim-
inary environmental assessment of FBC. A key task in this effort is the
application of theoretical calculations and engineering considerations
to project deductively what the emissions may be from FBC units of poten-
tial pollutants which have received little, if any, attention in past
experimental studies. This project is to be completed in 1976.
Several projects are planned for completion in 1976 involving com-
prehensive analysis of emissions from FBC units. Battelle-Columbus Labora-
tories will propose an approach for comprehensive analysis of emissions,
and will test this approach on a 6-inch i.d. atmospheric FBC unit. Com-
prehensive analyses will also be conducted on: a 2- by 3-foot (cross-
section) pressurized FBC unit at the British Coal Utilization Research
Association; a 7-foot i.d. pressurized FBC pilot plant operated by Com-
bustion Power; and the pressurized bench-scale equipment and the FBC
Miniplant at Exxon Research and Engineering. Comprehensive analyses will
also be conducted on other units as plans develop and as these other
units become available. Comprehensive analyses will involve testing not
only for the pollutants which have received emphasis in the past, such
as S02 and NO, but will include: S02; S03: sulfides, sulfites, and sul-
fates in solid streams; reduced sulfur species in the flue gas, such as
H2S, COS, and CS2; NO; N02: nitrites and nitrates; all individual organic
compounds, such as polycyclic organic matter and polychlorinated bi-
phenyls; halogens; all trace elements and trace element compounds that
might be expected based upon the coal ash and sorbent composition;
particulates (total mass, size distribution and morphology); and bio-
logical testing.
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Mitre is developing manuals for alternative variations of the FBC
process which will outline available sampling/analytical technology for
comprehensive analysis on these variations, including recommendation of
tentative sampling/analytical procedures, and identification of sampling/
analysis R&D needs.
Three experimental and engineering -studies are underway, including:
engineering and primarily small-scale experimental work, being conducted
by Westinghouse Research; laboratory-scale and bench-scale studies by
Argonne National Laboratory (including work on a 6-inch i.d. pressurized
combustor and a 4-inch i.d. pressurized sorbent regeneration vessel) in a
project cofunded with the U.S. Energy Research and Development Administra-
tion (ERDA); and bench-scale and Miniplant studies by Exxon R&E. These
three studies involve, in general: (1) investigation of SO control using
A
limestone/dolomite and alternative sorbents, and of regeneration of
these sorbents; (2) NO formation and control in FBC; (3) particulate
X
control requirements and control device testing; (4) emissions and
control of other pollutants, such as trace elements and hydrocarbons; and
(5) minimization of other environmental impacts.
A major accomplishment during 1975 was the successful shakedown of
the combustor on the FBC Miniplant at Exxon. (See photo.) The Miniplant
system, built under IERL-RTP sponsorship, is the largest existing FBC
facility capable of operating at its full range of conditions. The Mini-
plant combustor, which is 12.5 inches i.d., is capable of burning up to
480 pounds of coal per hour (0.63 MW equivalent). As part of the shake-
down operation, the combustor was operated for a sustained run at steady
conditions lasting over 100 hours. Interruptions during the 100-hour
period totaled less than 3 hours. The bed material during the run con-
sisted of limestone particles which reacted with the S02 generated by
combustion of the coal. Emissions of NO were suppressed during the run
/\
to levels well within EPA's current New Source Performance Standard for
coal-fired boilers. The Miniplant system also includes an 8-inch i.d.
sorbent regenerator, for which shakedown has not yet _been completed.
A second major accomplishment on the Miniplant was operation of the
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SORBENT
REGENERATOR
630-KW Exxon miniplant for pressurized (10atm) fluidized-bed combustion of coal.
80
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combustor at controlled conditions for a sustained period lasting 240 hours.
Interruptions during the 10-day operation totaled only 4 hours. The
240-hour run demonstrated the long-term operability of the Miniplant com-
bustor, and provided environmental data over a range of operating con-
ditions. S02 removals of greater than 95 percent were achieved by addition
of dolomite particles at rates such that the ratio of the moles of calcium
in the sorbent feed to the moles of sulfur in the coal feed was 2.0 to 2.5.
Dolomite feed at a calcium-to-sulfur mole ratio in the range of 0.5 to 1.0
was adequate, with the 2 percent sulfur coal burned during this run, to
reduce S02 emissions sufficiently to meet EPA's New Source Performance
Standard for coal-fired boilers (1.2 Ib S02/106 Btu heat input, or 0.51
g/106 J). NO emissions during the run averaged 135 ppm, which corre-
y\
spends to an emission level of 0.17 lb/106 Btu heat input (0.074 g/106 J)
expressed as N02. This level is well below EPA's New Source Performance
Standard for coal-fired boilers of 0.7 lb/106 Btu (0.30 g/106 J).
A small, flexible, atmospheric-pressure Sampling and Analytical Test
Rig is planned by EPA for comprehensive analysis activities, for testing
of sampling and analytical procedures, and for investigation of alternative
add-on pollution control devices.
Two projects are planned aimed specifically at the disposal and/or
utilization of liquid and solid wastes from FBC systems. One project will
be with a contractor to be selected early in 1976; the second, with the
Tennessee Valley Authority.
Finally, three paper studies are being conducted. Dow Chemical is
projecting the effect of experimental scale on emissions from FBC units.
This project should provide an initial indication of the scale on which
environmental data must be generated in order to be scaled up reliably to
commercial-scale FBC systems. Exxon R&E is conducting an energy, economic,
and environmental analysis of FBC of coal for industrial applications (in
a study cofunded with the Federal Energy Administration and ERDA). TVA
is conducting a cost comparison of atmospheric-pressure and pressurized
FBC with conventional boilers involving flue gas desulfurization. The
results of these projects should be available in 1976.
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FLUIDIZED-BED GASIFICATION/DESULFURIZATION OF RESIDUAL FUEL OIL
The Chemically Active Fluid-Bed (CAFB) process for gasifying and de-
sulfurizing 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 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 approximately
400 hours' duration. In addition to 90 percent sulfur removal at a cal-
cium-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 NO emissions from 263 ppm (when the boiler was oil-
A
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 demonstration of a nominal 10 MW unit is being
considered at San Benito, Texas. A contract has been executed between
Foster Wheeler Energy Corporation (FWEC) and IERL-RTP for the engineering
and testing portion of the proposed demonstration. The private utility
and Foster Wheeler are cooperating in the design phase with support
from Esso England, developer of the process. Arrangements for the con-
struction and fabrication of the CAFB unit at San Benito are between the
utility and FWEC.
Contracts for the multimedia environmental assessment of the CAFB
and other methods of utilization of residual oil fuels have been awarded
to Westinghouse Research and are pending to other contractors. The objec-
tive of the program is the environmentally acceptable use of residual
fuels.
Advanced Low-Emission/Energy-Conserving Systems/Strategies
IERL-RTF's efforts in this area are directed in four channels: the
EPA-Van, a heat and emissions loss prevention system (HELPS) for area
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source furnaces, electrical energy and waste heat as clean energy for area
sources, and fuel distribution patterns as a means of controlling area
source pollution.
ERA-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 commer-
cial buildings. The pollution control technique used here is an energy
supply system containing environmentally clean and energy-saving compo-
nents. The EPA-Van's integrated system includes fuel cells, solar energy
collectors, a specially-designed heat pump, and catalytic burners. This
equipment is nonpolluting and is designed to optimize the energy-conserv-
ing features of each of the components. The system provides all the energy
needed for space heating, cooling, and ventilating; cooking; lighting;
food refrigeration; water heating; and appliances.
Engelhard Industries Division, under contract to IERL-RTP, has
designed and is building the Van. Delivery is scheduled for early 1976.
The testing program for the Van is scheduled to begin soon after its de-
livery to Research Triangle Park.
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 result-
ing from use of the coupled solar-energy/heat-pump system and the in-
herently 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 con-
sumable fuel, and the economic impact of the presently expensive fuel
cells and catalytic combustors. The EPA-Van is shown in the photo.
HEAT AND EMISSION LOSS PREVENTION SYSTEM (HELPS)
An lERL-RTP-funded study was undertaken by Aerotherm to assess the
potential for reducing environmental emissions from residential furnaces
by improving furnace energy efficiency. Such emission-reduction/efficiency-
improvement might be achieved by retrofitting heat-recovery/cleanup equip-
ment to existing furnaces, or by developing new furnace designs which
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Artist's conception of EPA-Van.
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are inherently more efficient and/or lower in emissions.
The initial phase of the effort showed that a direct-contact heat
exchanger in an oil-fired furnace could achieve a reduction in emitted
pollutants along with a decrease in fuel consumption. A feasibility study
is being carried out to evaluate the overall balance for retrofitting
furnaces with these heat exchangers.
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, com-
mercial, and industrial sectors as a supplement or substitute for clean
premium fuels such as natural gas, distillate oil, SN6, 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 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 end-
use sectors can be implemented. Electrical substitution does offer the
potential for significant future reductions in the amount of natural gas
and distillate fuel oil consumed in the residential, commercial, and
industrial sectors.
FUEL DISTRIBUTION PATTERN FLEXIBILITY
Battelle, funded by IERL-RTP, has completed a study designed to quanti
fy the amount of clean fuels (natural gas, distillate fuel oil, low-sulfur
residential 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 is
currently being written, with publication anticipated early in 1976.
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Under the study, an evaluation was made of factors affecting the
ability to switch fuels between users (e.g., equipment-related factors,
business factors, fuel supply network factors), and the quantities of
fuel affected by each factor.
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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 tech-
nology, emissions and effluent technology, and particulate technology.
The following subsections of this report discuss these groupings sepa-
rately.
PROCESS TECHNOLOGY
Flue Gas Desulfurization—Regenerable Processes
MAGNESIUM OXIDE (CHEMICO MAG-OX) SCRUBBING
The Mag-Ox scrubbing process, developed and currently offered com-
mercially by Chemical Construction Company (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 oxides and
particulates 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 ca-
pable 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). Scrub-
bing, centrifuging, and drying operations were located at Boston Edison's
oil-fired Mystic Station; a regeneration system was constructed as Essex
Chemical's sulfuric acid plant in Providence, R.I. The system was
87
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_ABSORBER
V INLET
\ 1 DUCTWORK
'
MgO STORAGE
SILO
ABSORBER
OUTLET
BREECHING
DUCTWORK
FROM BOILER
RECYCLE
PUMPS
(NOT VISIBLE)
.
EPA/Boston Edison demonstrate Mag-Ox process.
-------
started up in April 1972. Results obtained during 2 years of operation
indicate that sulfur dioxide removal efficiencies in excess of 90 per-
cent were obtained consistently, using both virgin and regenerated mag-
nesium oxide. Additionally, more than 5,000 tons of commercially sale-
able sulfuric acid of high quality was produced from the sulfur recover-
ed from the stack gas. A number of problems were solved that were pri-
marily equipment (rather than process) related. Consequently, continu-
ous, long-term, reliable operation was not achieved. However, from mid-
February until June 1974, the scrubbing system demonstrated an avail-
ability 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 scrub-
bing system at its coal-fired Dickerson Station. Since completion of
the EPA/Boston Edison program in June 1974, EPA has provided the Provi-
dence Mag-Ox regeneration system for Potomac Electric1s use in process-
ing spent scrubber sorbent. Potomac Electric is supplying data relative
to overall system operation on coal-fired plants. Results indicate SO
/\
removal efficiencies greater than 90 percent with few discernible dif-
erences between coal- and oil-fired 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 is evaluating the feasibility of producing
elemental sulfur directly from magnesium sulfite. This would expand the
applicability of current Mag-Ox processes. Another study is concerned
with the mechanism of formation of tri- and hexa-hydrate forms of mag-
nesium sulfite (MgS03 • 3H20, MgS03 • 6H20). 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 will
attempt to generate information on formation mechanisms and operating
conditions that can be used to control the type of crystal formed.
SODIUM SULFITE/BISULFITE SCRUBBING WITH THERMAL REGENERATION
(WELLMAN-LORD)
IERL-RTP and Northern Indiana Public Service Company (NIPSCO) are
jointly funding the design and construction of a flue gas cleaning
89
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demonstration system utilizing the Wellman-Lord S02 recovery process.
The Allied Chemical SOa 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 startup is being borne
equally by IERL-RTP and NIPSCO. The operational costs for the system
will be borne solely by NIPSCO, and a detailed test and evaluation pro-
gram will be funded by IERL-RTP. The demonstration system is being
retrofitted to the 115 MW, coal-fired Boiler No. 11 at the D.H. Mitchell
Station in Gary, Indiana. (See photo.)
Phase I of the three-phase program, completed in December 1972,
entailed the development of a process design, major equipment specifi-
cations, and a detailed cost estimate. During Phase II, initiated in
June 1973, the final design and construction will be completed by Davy
Powergas, Inc. (owner of the W-L process). Davy is constructing both
the W-L and Allied portions of the system. At the completion of startup
activities, scheduled for April 1976, 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 solu-
tion to absorb S02 from gas streams containing a wide range of inlet S02
concentrations. Spent absorbent, rich in bisulfite, is processed in a
steam-heated evaporator/crystallizer, regenerating active sodium sulfite
and a stream of S02 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 ^ Na2S03i + S02+ + H20+
heat
The process generates inactive sodium sulfate by three mechanisms: S03
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 an
additional system product as well as loss of useful sodium ion, much
90
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Wellman-Lord process to be demonstrated.
-------
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 the most saleable and
environmentally sound product, elemental sulfur. The Allied process
utilizes natural gas as a reductant in a novel catalytic reactor system.
The process has been demonstrated on a large scale, treating a 12-per-
cent 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,
product quality, and material and utility requirements. This confidence
is based on the already appreciable quantity of successful operating
experience to date for W-L systems on various applications including acid
plants, Glaus plants, and oil-fired boilers. About 20 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 requirement, 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 test-
ing 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 accepted. 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
92
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ELECTROSTATIC
PRECIPITATOR
LJUNGSTROM
HEAT
EXCHANGER
i
EPA/Illinois Power demonstrate Cat-Ox process.
93
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problems have precluded successful initial operation and initiation of
the comprehensive 1-year test program.
The Cat-Ox system is available in two configurations: the Reheat
system for retrofitting existing plants, and the Integrated system for
incorporation into new power generating facilities. The Reheat system
(being demonstrated at Wood River) operates with the flue gases first
passing through a high efficiency (99.6 percent) electrostatic precipit-
ator. Then, in preparation for the catalytic conversion of the S02 to
S03, the temperature must be raised to about 850°F. This heat is added
in three increments: a primary input from an external combustor, a gas
heat exchanger, and a secondary input from the external combustor. After
being heated, the S02 contained in the flue gases is converted to S03 by
catalyzed reaction with 02. Exiting the converter, the hot flue gases
pass through the high-temperature side of the gas heat exchanger and on
to the acid production section. The sulfuric acid is formed by the stand-
ard S03/H20 absorbing tower contact process. The product acid is cooled
and sent to storage, while the flue gases pass through a fiber-packed
mist eliminator (where the residual traces of sulfuric acid mist are
removed), and then to the stack where the clean gases exit to the atmos-
phere. At this point, essentially all particulate matter, as well as
85 percent of the S02, has been removed from the stream.
Trace and hazardous element analyses account for an important por-
tion of the overall Cat-Ox test program. A complete characterization
of Wood River Unit No. 4 (prior to Cat-Ox equipment tie-in) included
analyses for some 30 trace elements in the coal, hopper ash, and slag
as well as in the fly ash (where elemental analysis has been done for a
complete range of size fractions). These tests will be repeated during
a 1-year test program to determine the effects of the system on the
concentration and distribution of trace elements.
Several studies are underway on Cat-Ox system design and operational
changes (if necessary), repair/refurbishment requirements, cost/schedule
impacts, and current process viability. A decision on the future of the
Cat-Ox demonstration program will be made following completion of these
studies.
94
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CITRATE PROCESS
IERL-RTP and the U.S. Bureau of Mines have entered into a coopera-
tive agreement to pool funds and technical talents in the interest of
demonstrating 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 are initi-
ating the demonstration of this technology on a nominal 100-MW coal-
fired utility boiler (coal to be at least 2.5 percent sulfur). Negotia-
tions are currently underway with prospective host sites and process
vendors. Contracts are to be signed in the spring of 1976 for this
project, which will include substantial cost sharing by the host site.
As shown in the generalized flow sheet, the Citrate process consists
of five steps: gas cleaning and cooling, S02 absorption, sulfur precipi-
tation and solution regeneration, sulfur separation, and H2S generation.
After gas cleaning and cooling (to remove particulates and to reduce
flue gas temperature), an aqueous solution containing sodium sulfite,
sodium bisulfite, sodium thiosulfate, and other sulfur compounds absorbs
S02 from the flue gas stream. The solution is buffered with citric acid
to maintain pH at an optimum level for high efficiency scrubbing and high
S02 loading capacity. The S02-rich scrubber liquor is then fed to a
series of reactors where gaseous H2S 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
H2S generator where it is reacted with reducing gas; the remainder is
sent to product storage for subsequent sale. The regenerated solution
is returned to the scrubber, and the H2S generator product is sparged
into the regeneration reactors.
SODIUM HYDROXIDE SCRUBBING WITH ELECTROLYTIC REGENERATION (STONE &
WEBSTER/IONICS)
In July 1972, IERL-RTP and Wisconsin Electric Power Company (WEPCO)
95
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ID
GAS CLEANING
AND
COOLING
CLEANED AND
COOLED GAS
FLUE
GAS
H20-
S02 ABSORPTION
TO ATMOSPHERE
SULFUR PRECIPITATION
AND
SOLUTION REGENERATION
H2S GENERATION
S02
LIQUOR
STEAM
REDUCTANT
GAS
The Citrate process.
-------
initiated a potential 3-1/2 year, three-phase program involving the
Stone & Webster/Ionics (SWI) sodium hydroxide scrubbing process.
During Phase I, an integrated pilot plant was built (see photo),
operating tests were performed over an approximate 1-year period, and
a prototype-scale electrolytic cell system was designed, fabricated, and
tested. Preliminary design of a 75-MW prototype system and development
of detailed test programs and operating schedules for the prototype sys-
tem were also accomplished. The Phase I final report was published in
May 1975.
A 16-month Phase II effort had been considered for the detailed
design, procurement, and installation of a 75-MW prototype. This would
have been followed by Phase III, a 12-month startup and operational
period for the 75-MW prototype. Based on an assessment of Phase I
results, however, work will not continue into Phases II and III.
The SWI process is a cyclic method of flue gas desulfurization
that was developed by SWI during the 5 years prior to the IERL-RTP/WEPCO
program. The process consists of four basic steps:
0 Absorption of SO from waste stack gas by sodium hydroxide.
A
0 Neutralization of the reacted sodium hydroxide solution (sodium
sulfite and bisulfite) with electrolytically produced sulfuric
acid to produce a sodium sulfate solution and to release and
recover sulfur dioxide.
0 Recycle of the sodium sulfate solution to an electrolytic cell
system.
0 Electrolytic conversion of the sodium sulfate solution into sul-
furic acid and sodium hydroxide for recycle.
Chief advantages of the process (expected to apply to both existing
and new power plants over a broad range of sizes) are: highly efficient
removal of SO ; production of easily handled nonslurry flow streams; no
/\
solid waste; and recovery of S02 for subsequent processing into lique-
fied S02, sulfuric acid, or elemental sulfur.
Disadvantages of the process include: power requirements for
electrolytic regeneration; unfavorable economic factors; and the need
to remove from the system any sulfates produced by oxidation in the
scrubber.
97
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CLEAN FLUE GAS-
ABSORBER TO STACK
FLUEGAS--PRECIPITATOR
OUTLET TO FD FAN
FLUE GAS-FD FAN
TO ABSORBER
• l. I
STRIPPER
BOTTOMS
DRUM
j I
WEPCO's Valley plant pilots Stone & Webster/Ionics process.
98
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The Phase I final report presents the pilot plant results and eval-
uates and assesses the process.
AMMONIA SCRUBBING WITH BISULFATE REGENERATION
Stack gases have been commercially desulfurized by contact with
solutions of ammonium sulfite and bisulfite since the mid-1930's. 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, is developing a completely cyclic ammonia-
scrubbing/bisulfate-regene'ration 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 absorp-
tion 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 evapor-
ated and the ammonium sulfate crystallizes. After separation, the
ammonium sulfate crystals are thermally decomposed into ammonium bisul-
fate 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 is being 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 ofxthe system
except the decomposer. S02 removal has generally been 90 percent or
greater, although overall operation has been successful. However, the
problem of eliminating the fine particulate ammonia-sulfur salts which
form in the scrubber has not been completely solved, and work is con-
tinuing. Efforts to solve the problem include improved mist elimination,
99
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CLEAN
GAS
I
SCRUBBED GAS RATE = 3,000 scfm
NH3
S
C
R
U
B
B
E
R
I
DIRTY GAS
J r
*"" SOLUTION
TANK
H20
S02
(NH4)2s33
1
ACID
STRIPPER
|
_ NH4 HS04
EVAPORATOR/
CRYSTALLIZER
^
1 ' II1U4J/OU4
SOLUTION
•
xV
(/)
/**
j
f
CONDENSER '
Hifl "" o
^
(NH4)2S04
(NH4)?S04 " DECOMPOSER
CRYSTALS -
Ammonia scrubbing with bisulfite regeneration.
100
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a prewash stage, scrubber modifications, and changes in operating pro-
cedures.
During 1976, work will continue on controlling plume formation and
on improving de-entrainment and mist elimination. If the plume can be
controlled and economic studies indicate that the process may be com-
petitive with existing processes, the system will be operated continuously
to evaluate long-term performance and reliability and to assess process
viability.
ACTIVATED CARBON
The use of multistage, dry fluidized beds of recycling activated
carbon appears attractive both for sorption of SO from flue gases and
A
for converting the removed SO to elemental sulfur. Under an IERL-RTP
A
contract, development of the activated-carbon-based flue gas desulfuri-
zation process was advanced to a stage where three major process units—
sorber, sulfur generator, and carbon regenerate)—were integrated for
continuous and cyclic operation.
In the sorption stage, shown schematically, combustion flue gas is
contacted with the activated carbon, and the contained sulfur dioxide
(in the presence of oxygen and moisture) is first catalytically convert-
ed 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 car-
bon is reacted with a measured quantity of reducing gas which sweeps
out the deposited sulfur. About 25 percent of deposited sulfur is re-
covered as a byproduct; 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.
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 encouraging results. Estimated process economics,
101
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T.flAI flRNATIIRAI
GAS GAS
*• PRODUCER i
/
AC1
CAR
FLUE GAS (S02)
H;
t*-H2 —
IVE
BON
\
^ SULFUR GENERATOR
i
f 1 *
SULFUR STRIPPER
1 ^
1
^ HYDROGEN SULFIDE GENERATO
\
SULFUR DIOXIDE SORBER
/~y SULFUR ^_
>Y^ PRODUCT
-rV
^>
R
_. CLEAN
FLUE GAS
Activated carbon process
102
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based on these results, appear to compare favorably with those of other
flue gas desulfurization processes. Westvaco, under contract to IERL-RTP,
will provide a detailed final report on this process early in 1976. The
report will include 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
.A
technology 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. Elemental sulfur may be the most desirable form
J\
for recovery of SO because it is the minimum quantity of any FGD waste
J\
or byproduct and because of its saleability, ease of transport, and suit-
ability for long-term storage.
Production of sulfur from SO requires the use of a reductant for
.A
conversion of the SO to sulfur: to date, major emphasis has been on the
X
use of 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 utilized in the future. IERL-RTP has embarked on a program lead-
ing to the demonstration of processes and equipment for economical genera-
tion of reductant gases from more plentiful ultimate sources, such as
coal, coke, residual oil, and petroleum coke.
As a first step, IERL-RTP has retained Battelle-Columbus Laboratories
to conduct process evaluation and cost estimates of gasification processes
which are suited for application to FGD requirements, and to recommend
avenues of continuing development and demonstration. The draft report on
this study is being reviewed. Publication of the final report is antici-
pated in the spring of 1976. Current plans call for the use of a reduc-
tant gas other than natural gas in the advanced regenerable FGD process
demonstration under consideration.
NON-UTILITY COMBUSTION SOURCE CONTROL
Modeling studies have shown that the impact of non-utility combustion
103
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(NUC) source S02 emissions on ambient air concentrations is higher than
anticipated from their fraction of the amount of S02 emitted. For exam-
ple, in St. Louis, area sources accounted for 15 percent of the S02 mass
emissions, but contributed 40 percent of the ultimate ambient concentration.
The first step in lERL-RTP's approach to reducing NUC source sul-
fur dioxide emissions has been to compile and standardize a data base
that characterizes 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 emission. 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 de-
scribed above, as well as from residential sources. Initial activity
is directed toward extending the characterization of NUC sources down
to small combustion sources. Recommendations of strategies and technol-
ogies 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 installa-
tion, off-the-shelf availability (essentially shop-fabricated), easy
operation by nonspecialized personnel, low capital and operating costs,
minimum waste products, useful or marketable byproducts, and multipol-
lutant control capability. All of this work was included in the final
report, "S02 Reduction in Non-utility Combustion Sources."
PEDCO-Environmental, Inc., under contract to IERL-RTP, is evaluating
the relative impact of SO emitted from utility and non-utility combus-
A
tion 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
104
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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 of SO emissions. Meetings will be held with
.A
regulatory agencies and industrial 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
Byproducts of flue gas desulfurization processes fall into two
categories: throwaway and saleable. In the latter category are sul-
fur, 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 pro-
duced from its coal-fired plants. The study assumed that TVA would be
the only utility producing abatement acid and that the existing produc-
tion, 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 re-
duce 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.
105
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A second phase of the marketing study is also underway. In this
phase, TVA is considering all potential abatement acid or elemental sul-
fur 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, Ne-
braska, 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
compliance 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. The report on this work is expected early in 1976. Results
are expected to be available to utilities and other interested organiza-
tions through a time-sharing computer program.
ENGINEERING APPLICATIONS/INFORMATION TRANSFER
The Process Technology Branch of IERL-RTP has initiated a program
to more effectively disseminate air pollution control technology data
and information to meet the needs of the user community. In the past
the Laboratory has attempted to meet its technology/information dis-
semination responsibility primarily through periodic symposiums, reports,
and personal communications. These activities will be continued, but
they will be augmented by a comprehensive Engineering Applications/In-
formation 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 in-
formation 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
106
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develop and implement effective mechanisms for dissemination of the
programs and materials to the user community.
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, 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 requirements/restrictions. Thus, the FGC-DM will make
available a means of effective, informed FGC decisionmaking which should
result in earlier operational dates, lower costs, and increased operability/
availability.
Flue Gas Treatment/N0x Removal
CATALYTIC REDUCTION OF N0y WITH AMMONIA
/\
Under contract to IERL-RTP, Environics, Inc., has completed a
program to demonstrate the feasibility of reducing nitrogen oxide (NO )
J\
emissions from natural-gas-fired boilers, using ammonia as a reductant
and platinum as a catalyst. The program involved a pilot plant opera-
tion, using flue gas (at a 250,000-scfh flow rate) at the Valley Steam
Plant of the Los Angeles Department of Water and Power.
The system involves contacting the flue gas with ammonia and then
passing the gas over a ceramic monolith coated with platinum. Reduction
efficiencies of between 85 and 90 percent were achieved at 450°F and at
a space velocity of 45,000 reactor volumes per hour.
Parametric testing was continued in 1974; i.e., varying space
velocity and temperature in conjunction with analysis for possible N20
formation. Approximately 2,000 hours of intermittent testing were accu-
mulated with no degradation of performance. Testing with natural gas
firing was suspended because of the shortage of natural gas. As a re-
sult of the shortage, the boiler was fired with low-sulfur oil distillate.
A flue gas heater was installed to permit raising the flue gas tempera-
ture to the range where the catalyst is most effective for flue gases
107
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containing some SO . The pilot plant was restarted in late-1974, at
A
which time the utility plant was firing oil. The platinum/ammonia sys-
tem was evaluated to determine the effects of S02 on the performance of
the catalyst. Results indicate that platinum is not a suitable catalyst
for oil-fired flue gas. The final report on this work is being com-
pleted for publication in the spring of 1976.
CATALYSTS FOR CONTROLLING NOV EMISSIONS
A
Under contract to IERL-RTP, a technical and economic assessment of
catalysts for controlling NO emissions from stationary power plants
X
was performed by TRW Systems Group. The effort began in February 1973,
and the final report was issued early in 1975.
The objectives of Phase I were: to review and evaluate domestic and
foreign developments in catalytic abatement of NO , to determine the tech-
A
nical and economic feasibility of abatement schemes, to evaluate the desir-
ability of adapting these schemes to power generating plants, and to
identify approaches best suited to this source of NO .
/\
Approximately 40 catalysts were screened to determine their poten-
tial for: nonselective reduction with hydrogen and CO; oxidation and
decomposition of NO; and selective reduction with ammonia, hydrogen,
and CO. A data bank of NO catalysts and catalytic processes was com-
A
pleted. This bank, as well as many other sources, was used to estimate
the cost effectiveness of various catalysts in reducing NO emissions
A
from stationary power plants. This work is described in detail in the
final report.
As a follow-on to this work, a research grant is underway with the
University of California at Los Angeles, to further characterize the
performance of nonnoble metal catalysts, primarily vanadia and iron/
chromium oxide, in the reduction of NO with ammonia in the presence
A
of oxygen and S02. This study would extend the catalyst screening
work performed earlier by UCLA, under contract with TRW, which indicated
that these two nonnoble metal catalysts were promising. The overall
objective of the project is to obtain the necessary data at the bench-
scale level of operation that will permit scale-up to the next level of
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equipment size. Various concentrations of V205 catalyst on alumina and
other carrier materials will be evaluated. Different Fe-to-Cr ratios
and different catalyst-carrier concentrations will also be tested to
optimize the iron oxide-chromium oxide catalyst. Promoters frequently
used to increase catalytic activity for S02 oxidation will be evaluated
for their effect on NO reduction. Once the optimum catalyst's specifica-
tions are determined, the effects of process variables will be examined
over broad ranges of temperature and residence time. Extended durability
testing will be performed to determine if slow accumulative catalyst
poisoning exists. Pre- and post-reactor gas stream analyses will be
performed to monitor the major components and to determine possibly
deleterious secondary effects. Working rate expressions will be devel-
oped for scale-up use.
ADVANCED CONCEPTS FOR NOV CONTROL
X
Under a task order to IERL-RTP, the Research Triangle Institute is
evaluating advanced effluent treatment concepts which may have potential for
NO control. Work has concentrated on scrubbing NO with various
X x
organic compounds. The project involves studies and laboratory evalua-
tion of promising concepts. The technical evaluation considers the
effect of effluent gases, liquids, and solids which may be generated as
a result of the treatment process. The task was oriented recently to
include an evaluation of technology and economics of the generation of
ozone for use in wet scrubbing of NO from flue gases. Ozone is used
A
in nearly all of the well developed wet scrubbing systems now-being
tested in Japan. This information is necessary for comparison of wet
and dry NO control techniques for development in the United States.
NO CONTROL STRATEGY ASSESSMENT
J\
The techniques for controlling NO emissions from stationary
A
sources are combustion modification and flue gas treatment. Combustion
modification reduces the amount of NO formed while flue gas treatment
A
removes the NO from the stack gases after it has been formed.
A
Currently, there are five Air Quality Control Regions (AQCR's) that
are classified Priority I with respect to nitrogen dioxide. These AQCR's
are Chicago, Los Angeles, New York, Baltimore, and Wasatch Front (Salt
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Lake City, Utah). It is possible that these AQCR's could be brought
into compliance by the application of NO control technology to the
A
stationary sources in these regions.
Radian Corporation, under contract to IERL-RTP, is to determine
the effect on ambient MO levels of applying NO control technology to
A X
stationary sources in one of these AQCR's where NO problems currently
A
exist. Another related task will result in a model of one of the five
Priority I AQCR's suitable for use in determining the effects on air
quality of various levels of emission reduction for various stationary
sources in the region. NO emissions reductions and costs will be
A
determined for combustion modification and for flue gas treatment
applications. The ambient air quality that would result from applying
various mixes of the NO control techniques will be determined. The
X
results will be assessed to determine if compliance for the selected
AQCR is achieved; assessment results will be extrapolated to the other
four NO Priority I Regions. The results will also assist in determine-
A
tion of control efficiency and performance requirements, and will aid
in assessment of research, development, and demonstration needs. The
results of this effort and recommendations for future work will be
presented in a final report in mid-1976.
NO FLUE GAS TREATMENT PILOT AND PROTOTYPE PROJECTS
A
In Japan, NO Flue Gas Treatment (FGT) is well advanced with a
X
number of processes at pilot, prototype, and commercial levels. This
results from more stringent standards which require the high level of
NO control that can only be achieved by flue gas treatment. Applica-
X
tions are on gas- and oil-fired combustion sources. IERL-RTP is pro-
moting the adaptation of this technology to a U.S. coal-fired situation.
Importation of the technology could lead to large savings in research
and development time and money.
IERL-RTP personnel have visited Japan to examine those processes
which appear amenable to coal-fired application, and to discuss U.S.
development work with the appropriate vendors. It is anticipated that
the funding provided for FGT in 1976 will be supplemented by utility
industry participation so as to initiate meaningful "hardware" projects
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in 1976-77. The effort in this pilot and prototype development program
will center on importing the best of the Japanese technologies and
adapting them to U.S. coal-fired sources.
EMISSIONS/EFFLUENT TECHNOLOGY
Flue Gas Desulfurization—Non-regenerable 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 lime-
stone or lime slurries to remove sulfur oxide and particulate pollutants.
Results of many studies, ranging in size from pilot to full scale, in-
dicate that the processes are capable of high-pollutant removal rates
with acceptable reliability.
IERL-RTP is supporting several lime/limestone research, develop-
ment, 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
in-house pilot plant, located at Research Triangle Park, N.C. A demon-
stration on a 37-MW unit is being conducted at the City of Key West
(Florida) Stock Island power plant. A program involving carbide and
commercial lime scrubbing tests and an evaluation of scrubber waste
treatment disposal options (being negotiated with Louisville Gas and
Electric Co.) is discussed later, under Waste and Water Pollution Con-
trol. Under an interagency agreement with the U.S. Air Force, IERL-RTP
is funding a comprehensive test program to characterize the Swedish
Bahco lime scrubbing process at a site being built at Rickenbacker Air
Force Base, near Columbus, Ohio. The Bahco test program is expected to
begin early in 1976.
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. Process disadvan-
tages 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
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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 facil-
ity, consisting of three different (but parallel) scrubber circuits, can
handle about 90,000 cfm (30-MW equivalent) of the output of one of the
10 coal-fired Shawnee boilers. The versatile facility is being used to
evaluate the performance and reliability characteristics of lime/lime-
stone 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 com-
pleted 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).
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 (in-
cluding chemical fixation) for disposal 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 reported
periodically in progress reports, the first of which was published in
September 1975.
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 (lime scrubbing) was
achieved at greater than design gas velocities. The TCA system was
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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 lime/limestone wet scrubbing demonstration at Shawnee plant.
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operated on limestone at design gas rates and without a wash tray. Vari-
able load operation of the venturi/spray tower scrubber 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 variation in inlet S02 concentration. Both ranges
are much more severe than expected in most commercial applications. Op-
eration of the scrubber was entirely satisfactory throughout the period.
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 3-
stage TCA scrubber, scrubber effluent hold tank, lime slaker, fans,
thickeners, and rotary vacuum filters. Their compactness permits mate-
rial balances to be performed on each component to determine the extent
of all reactions occurring within it. Operating variables are investi-
gated over ranges that cannot be achieved (or are not practical to
attempt) in the larger units, such as operating without chloride, with-
out fly ash, and at varying inlet oxygen and sulfur dioxide levels in
the flue gas.
During 1975, work at the pilot unit was concentrated on improving
limestone utilization and on forced oxidation of limestone sludge to
gypsum. In cooperation with the Bureau of Mines and Sanderson-Porter
Engineers, some work was also done on the scrubbing of S02 with lignite
fly ash. This concept was found to work well when sufficient fly ash
was available.
The results of the limestone utilization work at the pilot unit have
been very encouraging. The problem was approached from two directions:
that the utilization was limited by contact efficiency in the scrubbers;
and that utilization was limited by the kinetics of the reactions which
occur in the holding tank. Both assumptions were true. The use of
multiple-stirred holding tanks, rather than a single tank, allowed the
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SCRUBBER
EFFLUENT
HOLD TANK
IERL-RTP lime/limestone scrubber pilot plant.
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reactions to go to a greater degree of completion and led to higher
utilization. The use of greater scrubber bed depth also increased lime-
stone utilization.
To further improve utilization, the pilot unit was set up as a two-
stage scrubber with a primary TCA scrubber at 7 to 8 in. H20 pressure
drop, and a secondary spray scrubber at 0.5 in. H20 pressure drop. This
two-stage scrubber, with multiple-stirred holding tanks on the primary
scrubber and using the forced conversion to gypsum described below, was
able to achieve a 96 percent utilization of limestone and 85 percent S02
removal. This can be compared to a base case (one-stage scrubber at 7.5
in. H20 pressure drop, one stirred holding tank) which yields 83 percent
limestone utilization and 76 percent S02 removal. In larger scale units,
limestone utilization is normally even lower--60 or 70 percent.
The forced oxidation of limestone sludge to gypsum was achieved at
the pilot unit by sparging air into the first-stage holding tank. Com-
pletely oxidized sludge has a greatly improved settling rate and also
settles to a more compact solid. This has been demonstrated before, but
the pilot unit was able to obtain complete conversion to gypsum with an
air stoichiometry of 3 and at atmospheric pressure. Previous work had
required more air and elevated pressures, plus the addition of catalysts.
In combination, these improvements make a considerable difference
in the amount of limestone which is consumed by a scrubber. There is
also an attendant reduction in the amount of sludge generated. Compar-
ing the recent work to typical limestone unit utilization, there is a
17 percent reduction in the amount of sludge produced. The application
of these techniques to full-scale units will be a significant advance in
the technology.
City of Key West
The variation of the limestone wet scrubbing process being tested
in Key West includes most of the general concepts of the basic process.
Because of the City's unique location, coral marl (a relatively pure
form of calcium carbonate) and seawater compose the sorbent slurry. An
unusual scrubber design allows both relatively good liquid/gas contact
and a high liquid/gas ratio at a relatively low pressure drop. The
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system operates as an open loop; i.e., without recirculation of the
clarified liquor.
The City of Key West, under an IERL-RTP demonstration grant that
provided partial funding, has installed the process on a new 37-MW oil-
fired boiler. Under an IERL-RTP contract, Engineering Science, Inc.
is continuing a test program to characterize this type of system. The
program includes primary variable testing and optimization tests. Op-
eration during 1975 has been limited, due primarily to mechanical and
corrosion problems associated with the scrubbing system.
Banco Process
In 1971, Research Cottrell 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 particu-
late removal system followed by a unique, two-stage, 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 indus-
trial boiler applications.
There are about 20 Bahco scrubbers in operation in Sweden and Japan;
however, the installation at Rickenbacker Air Force Base will be the
first in the United States, and the first on a coal-fired boiler any-
where. The boiler on which the Bahco module is being placed is a 24-MW
unit operated only during the heating season. The lERL-RTP-sponsored
test program is expected to follow the startup early in 1976.
DOUBLE-ALKALI
The double-alkali process, like the lime/limestone wet scrubbing
processes, produces a throwaway product consisting of fly ash and cal-
cium sulfite/sulfate. The process, in its various forms, was developed
in an effort to avoid the problems associated with the use of absorbent
slurries in the lime/limestone processes.
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Flue gases are scrubbed, using a soluble alkali (usually sodium-
based) solution as the absorbent. The spent absorbent solution is treat-
ed with lime and/or limestone in a regeneration system to produce a re-
generated soluble alkali for recycle to the scrubber system and a throw-
away product for disposal.
Although less developed than lime/limestone wet scrubbing processes,
double-alkali systems show potential for attaining high sulfur oxide re-
moval efficiency and good reliability at relatively low cost.
Technology Development
To more fully test and characterize double-alkali systems, IERL-RTP
contracted with Arthur D. Little, Inc., to conduct laboratory, pilot
plant, and prototype studies of attractive double-alkali operating
schemes. These studies were initially supplemented by an in-house IERL-
RTP laboratory program. The pilot plant testing, at a 2,000-cfm facil-
ity owned by A. D. Little, was started in November 1973 and is still in
progress.
Prototype testing of the double-alkali process is being conducted at
a 20-MW facility installed by the Southern Company at Gulf Power Com-
pany's Scholz power station. The system is being tested under typical
power plant operating conditions, and has averaged 98 percent availability
during 6 of the 11 months from startup to January 1976. Overall avail-
ability during the period was 69 percent. The system has been removing
90 to 98 percent of the inlet S02. The work at the prototype unit is
continuing, with emphasis on optimizing process variables while operating
with a more typical coal sulfur content.
General Motors Industrial Demonstration
IERL-RTP and General Motors are participating in a cooperative test
program on GM's 32-MW double-alkali sulfur dioxide control system in-
stalled on a coal-fired boiler at the Chevrolet transmission plant in
Parma, Ohio. GM designed and built the system, which went into opera-
tion in March 1974. IERL-RTP is funding a test program, initiated in
August 1974, to characterize the system. The final report for the test
program is scheduled for issue in 1976.
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Full-Scale Utility Demonstration
A full-scale demonstration of the double-alkali process is planned
for operation and evaluation in the late 1970's, with construction to
start in 1976. Contract proposals have been received and are being
evaluated by IERL-RTP. This demonstration unit will be at a high-sulfur
coal-fired boiler of at least 100-MW capacity: boilers in proposals
under consideration have capacities ranging from 150 to 575 MW. The
project is presently being planned in four phases: (1) design and cost
estimation; (2) engineering design, construction, and mechanical testing;
(3) startup and performance testing; and (4) 1 year of operation and
long-term testing.
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, 12 systems had been visited and detailed reports issued concerning
their operation. 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 are to be included
in future work.
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 con-
struction, or planned in the United States, and the MW capacity controlled
or to be controlled. As of November 1975, 115 such systems are planned
to control over 44,000 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 con-
trol program is a continuation and expansion of modest efforts initiated
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ro
C >
Three 20-MW prototype FGD systems at Gulf Power's Scholz plant.
-------
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, described 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 Cincin-
nati 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 to IERL-RTP,
has been conducting a broad-based study to: (1) identify environmental
problems associated with FGC waste disposal; (2) assess current FGC
waste disposal methods, including feasibility, performance, and costs;
(3) make recommendations 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 the current program, initiated in 1974, the Chemfix, Dravo,
and IUCS processes for chemical fixation of scrubber wastes are being
evaluated in three separate disposal ponds. (See photo of one of the
ponds.) Untreated lime and limestone wastes are placed in two addition-
al ponds. 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. Future plans call for evaluation of
other disposal approaches, including gypsum disposal.
Louisville Gas and Electric Evaluation of FGD Waste Disposal Options
As part of a contract currently being negotiated, Louisville Gas
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ro
(X)
Test pond for disposal of Shawnee's chemically treated scrubber waste.
-------
and Electric Company is to conduct 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 stabilization of scrubber sludge will
be conducted and samples will be mixed with fly ash alone or fly ash
and one of several additions. The field studies will consist of small-
scale impoundment tests and larger scale (about 76-cubic-meter) landfill
tests in which leachate migration, runoff, and physical stability tests
of unstabilized and stabilized waste material will be conducted.
Lime/Limestone Scrubbing Haste Characterization
This project involves the physical and chemical characterization
of lime/limestone waste solids as a function of scrubber operating con-
ditions. Under these studies, lime/limestone scrubbing waste materials
from the Shawnee facility (and possibly other facilities) will be
characterized and the properties will be correlated with the scrubber
operating conditions. If feasible, a means of controlling waste char-
acteristics to improve disposal or utilization economics will be recom-
mended.
Characterization of Effluents from Coal-Fired Power Plants
This 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 adjust-
ment of pH to meet effluent standards, (3) evaluate an ash pond monitor-
ing program to determine the sampling and analyses necessary to obtain
representative 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
characterization efforts described below.
Ash Characterization and Disposal
This project involves TVA efforts to: (1) summarize and evaluate
existing data on the characteristics of coal ash and asTi effluents from
in-house TVA studies and from studies made by other organizations; (2)
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perform chemical and physical analyses on coal, coal ashes, and ash
effluents to obtain a complete characterization of these materials 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.
Alternative Methods for Lime/Limestone Scrubbing Waste Disposal
This project is one of several tasks which make up the economic
studies of major FGD processes being conducted by IERL-RTP. Several FGD
waste disposal methods and FGD system design and operating premises will
be selected for a detailed economic evaluation of FGD waste disposal.
Currently available information will be used in the initial efforts, with
updating as additional information becomes available.
Alternative FGC Waste Disposal Sites
This project is being conducted to identify, assess, and demonstrate
on a pilot scale, alternate FGC waste disposal methods (other than local
ponding and landfill ing). 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 economics of the alternate disposal methods, as well as a study
of applicable Federal and State regulations. Recommendations and con-
ceptual designs for the pilot demonstrations will be based on all of the
initial efforts.
FGC WASTES UTILIZATION
Lime/Limestone Scrubbing Haste Conversion Pilot Studies
In a cost-shared contract (currently being negotiated) 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 will be generated to allow scale-up to a large (prototype)
test unit for a power plant.
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Gypsum Byproduct Marketing
This project is one of several tasks which make up the F6D byproduct
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 eco-
nomic advantage over FGD waste disposal. These new studies include a
thorough economic evaluation of gypsum producing processes (e.g., Chiyoda,
carbon absorption, CaS03 oxidation) and a detailed U.S. marketing study
of abatement gypsum for wallboard. Future plans include studies of
abatement gypsum for use in Portland cement manufacture.
Fertilizer Production Using Lime/Limestone Scrubbing Wastes
One of several tasks being conducted by TVA under an Interagency
Agreement with IERL-RTP involves the use of lime/limestone scrubbing
wastes as a filler material for fertilizer. This study is a continuation
and expansion of previous bench-scale laboratory production tests and
small field plot application tests with rye grass.
POWER PLANT WATER REUSE
This program area currently consists of a single project—a study on
minimizing water use and wastewater discharges from coal-fired steam-
electric power plants. The study consists of six tasks: (1) Selection
and characterization of three or four specific 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 mini-
mize 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. (6) Detailed
presentation of program results, including recommendations of the re-
cycle/reuse options to be used at each of the plants studied. Future
plans call for pilot plant testing of one or more of the recycle/reuse
options.
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Thermal Pollution Control
COOLING TECHNOLOGY
lERL-RTP's programs in thermal pollution control technology fall in-
to two broad areas: cooling technology and waste heat utilization.
Cooling technology programs include studies on cooling system economics,
advanced heat rejection techniques, and the development of control tech-
nology for the treatment and possible reuse/recycle of cooling system
effluent streams. Waste heat utilization studies at present involve ag-
ricultural applications, although aquacultural and residential/industrial
uses also merit consideration.
In the past year, IERL-RTP initiated several studies on cooling
system performance and economics. The objectives of these projects in-
clude the definition of costs and other penalties imposed on power gen-
eration and the examination of environmental factors (i.e., drift, fog-
ging, water consumption) associated with various types of cooling devices.
In one such study, the contractor is developing a methodology and rigor-
ous computational techniques for optimizing the design of large dry cool-
ing systems. The design variables for the heat exchanger include tube
length, bundle width, and the number of rows and passes. Other parameters
which will be considered are site-specific factors (e.g., climate) and
cost factors (e.g., fuel, fixed charges, lost capacity, auxiliary power).
The objective is a user-oriented optimization procedure to examine the
effect of each variable on cooling system design and performance and its
relationship to the cost of power generation.
IERL-RTP is participating with the Town of Braintree, MA, in a sig-
nificant dry cooling tower demonstration and performance study. This
project, initiated late in 1975, involves the application of a direct
condensing system to a combined cycle (60-MW gas turbine/25-MW steam
cycle) power plant. Specific objectives include: (1) assessment of
steam flow distribution and temperatures to better define optimal design
characteristics, (2) meteorological effects from the plant and meteoro-
logical impacts on plant operation and performance, (3) noise generation
monitoring and control, (4) air quality considerations on or from the
plant, and (5) economic impact of design and operational factors.
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Two important considerations in power plant siting and cooling sys-
tem selection are consumptive water use and vapor plume emissions. Both
are inherent in the use of evaporative (wet) cooling towers. IERL-RTP
has initiated a study of the feasibility of utilizing wet/dry cooling
towers for water conservation and plume abatement. These towers use
both evaporative and convective heat exchange surfaces. Increasing dry
heat exchanger size reduces both water consumption and vapor plume emis-
sions. These reductions are obtained, however, at the expense of in-
creased capital and operating costs. For this study, the contractor will
conduct 10 site-specific evaluations in two phases. Five of these studies
will be concerned with minimizing water use: most of these sites will be
in the arid coal-rich region of the Western United States. The other
five plants will be at urban sites, where vapor plume abatement is the
objective. The technical and economic feasibility of using wet/dry
cooling at these sites will be evaluated, with due consideration to plant
operating characteristics, economic factors, and site-specific constraints.
IERL-RTP is supporting a TVA research program aimed at reducing the
effects of once-through cooling intake structures on the aquatic environ-
ment. A demonstration study to evaluate fish pumps for preventing the
impingement of fish against the intake screens at TVA's Browns Ferry
Nuclear Plant is nearing completion.
IERL-RTP is pursuing a program to develop and demonstrate control
technology for wastewater streams generated by evaporative cooling sys-
tems. In one study, the University of California is developing a system
for renovating cooling tower blowdown for recycle or reuse using new
evaporation technology. The project will use evaporators requiring sub-
stantially less capital and operation maintenance costs as compared to
those of the best present practice. Objectives are, first, to obtain
test data on the concentration of the Mohave power plant cooling tower
blowdown with a 5,000 gpd vertical tube evaporator (VTE) pilot plant,
both with and without the addition of a selected surfactant, to the
point of incipient crystallization of solutes. Test data will provide
an evaluation of heat transfer performance, upflow VTE stability/ foul-
ing tendency, and concentration factor obtainable. Secondly, the
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concentrated VTE blowdown will be foam-fractionated to remove the sur-
factant for recycle to the process, and to remove suspended particulate
matter such as dust. The concentrate will then be further evaporated in
a forced-circulation, crystallizing evaporator. Test data obtained from
this operation will be used to evaluate its heat transfer performance
and the chemical species and amounts of crystalline or solid materials
precipitated. This work, nearing completion, will provide a definition
of the problems inherent in this procedure for the renovation of cooling
tower blowdown, the best operating conditions and methods of process con-
trol, and an evaluation of the feasibility and costs. Future work will
involve the operation and testing of a mobile unit of 25,000 gpd capa-
city. This large mobile unit will be constructed and then serially lo-
cated at several utilities for an onsite evaluation of performance on
cooling tower blowdown streams. An evaluation of the benefits of using
the product water in various recycle/reuse schemes within the plants
will also be carried out.
Another alternative for renovating cooling tower blowdown and other
power plant wastewater streams for possible recycle/reuse within the
plant is treatment with membrane processes. lERL-RTP-supported research
in this area is being conducted by TVA. This project involves evaluation
of reverse osmosis and ultrafiltration systems supplied by major vendors
to determine their capability for treating the major wastewater streams
found in most fossil-fired power plants (i.e., ash pond discharge, cool-
ing tower blowdown, boiler blowdown, and S02 scrubber slurry waste
streams). Effluents will be supplied from various power plants through-
out the United States. The wastewater streams sampled will be chemically
characterized by TVA. The data will be used to design and then operate
the experimental treatment systems in an effort to minimize treatment
costs. An economic and technical evaluation will then determine the
feasibility of the prototype systems.
WASTE HEAT UTILIZATION
Beneficial use of warm condenser water has potential for alleviating
thermal pollution problems, generating secondary profits, and reducing
the fuel and energy demands of the use to which the waste heat is applied.
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During 1975, EPA, Northern States Power Company, and the University of
Minnesota initiated,a demonstration of the use of waste heat in a green-
house operation. A halfacre greenhouse was erected at NSPCo.'s Sherburne
County generating plant, which is under construction. Experiments will
be conducted using soil warming and heating/cooling of the air in the
growth chamber. In a related program of waste heat utilization, TVA is
cooperating with IERL-RTP in soil warming experiments to extend the crop
growing season. TVA is also studying the feasibility of using waste heat
to optimize 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 iden-
tified as transport vehicles for gaseous pollutants. The health hazards
of fine particulates are intensified by the tendency of metallic mate-
rials from high-temperature processes, such as pyrometallurgical and com-
bustion processes, to condense as chemically and catalytically active
fine particulates. Many toxic and potentially hazardous compounds are
also emitted as fine particulate. Particulate matter formed in the at-
mosphere from the reaction and condensation of reactions makes it diffi-
cult to relate atmospheric particulate pollution levels to specific
sources. This has hampered the development of effective control strate-
gies 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
formation 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.
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EPA has established a goal of setting fine participate standards.
To develop these standards, research and development is necessary to pro-
vide a minimum data base. This data base and the necessary adequate con-
trol technology 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 34 months, the Laboratory's Particulate Technology
Branch (PTB) has been engaged in a program aimed at determining the lim-
itations of conventional particulate control devices and defining an R&D
program which will eventually produce the needed technology for the con-
trol of fine particulate matter.
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 divided into six major areas:
0 Measurement.
0 Characterization and improvement of conventional control equip-
ment and assessment of the collectability of dusts.
0 New particulate control technology development.
0 New idea evaluation and identification.
0 High-pressure and high-temperature 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 sup-
port of the entire particulate control program; and (2) develop instru-
ments capable of determining efficiencies of control equipment on parti-
cle 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)
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develop a data base for decisions and judgements with respect to the
capability of commercially available control equipment; (3) develop im-
provements in conventional control devices which will eliminate deficien-
cies in their potential for fine particle control; and (4) determine
the ease or difficulty with which any given industrial 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 and the system required for control of almost any particulate
problem.
NEW PARTICULATE CONTROL TECHNOLOGY DEVELOPMENT
The goals for this area are: (1) assess all potential collection
mechanisms; (2) initiate exploratory projects to evaluate feasibility of
concepts and/or mechanisms; and (3) develop pilot units for promising
systems.
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 promising devices.
HIGH-TEMPERATURE AND 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 me-
chanics of aerosols at high temperature and high pressure; (2) using this
fundamental information, choose the most promising collection mechanisms,
and mount an R&D effort aimed at exploiting these mechanisms; and (3)
develop the devices necessary to ensure the environmental acceptability
of the advanced energy systems.
ACCELERATED PILOT DEMONSTRATIONS
Work in this area will be dedicated to the early pilot demonstration
of candidate fine particle control equipment to real world problems.
Current Program Status . _
MEASUREMENT
Current devices used for measuring particle size on control equip-
ment include impactors, optical counters, diffusion batteries, and
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condensation nuclei counters. These devices require lengthy manual tech-
niques for operation, and their reliability is less than satisfactory.
For instance, with current measurement technology, it is not always pos-
sible to discern the difference between a device collecting 90 percent of
particles less than 0.5 microns in size 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 mea-
sure 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 op-
erating on a number of sources ranging from power plants to aluminum
plants. Data from these tests clearly show that ESPs can collect parti-
cles of all sizes with high efficiency when dust resistivity is not a
problem. Data and theoretical predictions indicate that high dust re-
sistivity 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 be-
ing extended to low temperatures in an FY 75 funded program. One outcome
of this work has been the recognition of sodium as a potential condition-
ing 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 possi-
ble means of improving the collection of fine high resistivity particles.
A fundamental study and limited pilot plant work on fine particle charg-
ing were funded in FY 74.
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 sizes ap-
proaching 0.01 microns. Programs currently underway will improve the
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model by better defining 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 collecting high resistivity fly ash.
The broad objective of the ESP improvement program is to develop an
ESP of moderate size (specific collection area < 300 ft2/!000 acfm @
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 effi-
cient 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 com-
pletion 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/!000 acfm at 700°F or 690 ft2/!000 cfm at 300°F. The object
ESP would require an SCA of only 180 ft2/!000 cfm at 300°F for the same
efficiency.
Scrubbers
The Industrial Environmental Research Laboratory has tested approximately
eight scrubbers of conventional design on a variety of particulate sources.
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2.6
99.9
CAPITAL COST, $10^/1000 acfm
7.8 10.4
15.6
COMPUTED PERFORMANCE
AT 40 NA/CM2
TEMPERATURE ~300°F
200 300 400
SPECIFIC COLLECTING AREA, FT2/ 1000 acfm
Capital cost of ESP's vs. computed performance.
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In general, the performance or efficiency of a scrubber drops off rather
rapidly as the particle size decreases. Also efficiency is directly re-
lated to the energy consumed by the scrubber.
The broad objective of the fine particle scrubber program is to de-
velop 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 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
developing 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 collection. 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 un-
knowns at present. Since answers to both questions are likely to be
source specific, pilot demonstrations on a variety of sources are neces-
sary to provide required data. A pilot demonstration is underway and an
additional one is planned for FY 76.
With two possible exceptions, all the non-FF/C scrubber work con-
firms these data. The first possible exception resulted from liquid
utilization research at Standford Research Institute: it indicated that
a series of low-energy, low-efficiency scrubbers might achieve much high-
er total efficiency at a given energy consumption than could a single
high-energy scrubber. This lead, plus final confirmation of the graph,
will be followed up by research funded in FY 75.
The other possible exception to the figure is the TCA or mobile bed
scrubber. The figure shows data from field tests of TCA scrubbers. Note
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CO
0.12
OPERATING COST, $103/yr/1000 acfm
0.24 0.48 1.44 2.4
ASSUME: POWER COST 2.54/KWHR 8000 MRS OPERATION
PER YEAR
3 4 56789
20 30 50 70 90
PRESSURE DROP, cm HzO
Scrubber operating cost vs. aerodynamic cut diameter.
200 300
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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 multistage) are less efficient
than venturi scrubbers. An FY 75 program will provide the explanation
for the observed performance and design equations and theoretical models
for mobile bed scrubbers. FY 76 funds will be used to investigate ef-
fects of slurry scrubbing on mobile bed scrubber performance.
The overall efficiency of a scrubber system is determined by the
efficiency 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 nearly completed a systems study of entrainment separators.
FY 76 funds will be used to develop and demonstrate high-efficiency and
trouble-free entrainment separators in conjunction with SO scrubbing
R&D.
Fabric Filters
The performance of baghouses has been completely characterized on
three sources: two utility boilers and one industrial boiler. The data
obtained from these tests show that baghouses are relatively good fine
particle collectors and that their performance is not very sensitive to
particle size down to at least 0.3 microns. A major advantage of fabric
filters is that they will not require increases in size or energy usage
for efficient collection of fine particles.
The current purpose in maintaining an R&D program in fabric filtra-
tion is to promote increased capabilities and extend the range of appli-
cability in control of fine particulates. Of the three conventional de-
vices which can collect fine particles, fabric filters have been in in-
dustrial service longest, but the least information is known about their
operation from a theoretical standpoint. Although the filter is a simple
device in operation, there are complex problems in describing it mathe-
matically. These 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
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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 mathematical models for fil-
tration processes.
Filtration work performed under lERL-RTP's Particulate Technology Branch
(PTB) has been aimed at acquiring information for a twofold use: incor-
poration into mathematical models, and addition to the empirical knowl-
edge 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; development of mathematical descriptions for
specific parts of the filtration process; characterization of fabric fil-
ters in the field; investigation of electrostatic effects; support of a
pilot program to apply fabric filtration to industrial boilers at a sev-
eral-fold increase over normal filtration velocity; and studies of clean-
ing and energy consumption in bag filters.
Industry can handle most of the filtration problems for sources which
are already controlled by fabric filters. Help is needed for sources
which present 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 R&D program in fabric fil-
tration, IERL-RTP also maintains a hands-on in-house program. Its objec-
tive is to identify superior fabric filter materials and operating condi-
tions by conducting screening studies on in-house equipment. It has pro-
vided 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 when tested on in-house equipment.
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Laboratory work to complement and support grants, contracts, and
other in-house tasks will continue. Tests such as studies of fabric
type, cleaning variables, effects of humidity, 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. Preliminary
tests are being conducted to determine the optimum utilization of a Cli-
met Particle counter, a Thermo-Systems Electrical Aerosol Counter, and
a condensation nuclei counter. The overall objective of using these in-
struments is to determine the collection profile of a complete filter
cycle.
A new versatile fabric (baghouse) test chamber was ordered in FY 75.
This device will be capable of testing bags at both high and normal tem-
peratures 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 trans-
ported from source to source and tested is being constructed and will be
used in support of this program.
A mobile fabric filter and a mobile scrubber unit have been complet-
ed and a mobile ESP unit is scheduled to be completed by early 1976.
These mobile units are highly versatile and will be used to investigate
the applicability of these control methods to the control of fine parti-
culate 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 particulate programs, will permit selection by equipment users of
collection systems that are technically and economically optimum for spe-
cific applications.
NEW PARTICULATE CONTROL TECHNOLOGY DEVELOPMENT
This program area has become known as "New Concepts." As the
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requirement to collect finer and finer participate 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 ex-
pensive. The objective of new concepts R&D is to develop new mechanisms
or new combinations of well-studied mechanisms in order to achieve cost
effective control of fine particulate not easily controlled by conven-
tional 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,
interception, and diffusion; and by ESPs, are field and diffusion charg-
ing. 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 con-
ditions such as high temperature, high ash resistivity, sticky particu-
late, 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
removal mechanisms with scrubbing or filtration mechanisms. The first
area to be developed was charged droplet scrubbing with a feasibility
study at M.I.T. and a pilot demonstration at TRW on a Kaiser coke oven.
Electrostatics and filtration are being studied at both BNW and Carnegie
Mellon: the former with bed filters; the latter with baghouses. A new
concept in the use of electrostatics is under development at the Univer-
sity of Illinois, using a.c. fields. At least two new concepts—a ceramic
membrane filter and a magnetic metallic fiber bed—are oriented toward
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 the early stages of development so that
no demonstration data is available. The TRW charged droplet scrubber is
currently being demonstrated and will provide an indication of possible
technology advances. IERL-RTP has evaluated nearly 30 new concepts
HO
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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
soliciting, stimulating, and identifying new ideas for fine particulate
control.
As a part of this latter objective, lERL-RTP's Particulate Technol-
ogy Branch has planned and sponsored four symposiums and one seminar
aimed at fine particle control. PTB 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 de-
velopers. Under this program area, all such novel devices will be re-
viewed 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 30 novel particulate devices have been identified. About
half of these are of sufficient interest to justify evaluation by IERL-
RTP. So far, the following devices have been tested:
0 Braxton--Sonic Agglomerator
0 Lone Star Steel--Steam Hydro Scrubber
0 R. P. Industries--Dynactor Scrubber
0 Aronetics--Two-Phase Wet Scrubber
0 Purity Corporation—Pentapure Impinger
0 Entoleter—Centrifield Scrubber
0 Johns-Manville—CHEAF Filter
0 Rexnord—Granular Bed Filter
0 Air Pollution Systems—Electrostatic Scrubber
0 Air Pollution Systems—Electrotube 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
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to the Lone Star unit, but (in one test) did not appear to be as efficient.
In a field test, the CHEAP filter had an overall mass efficiency of 95
percent but maintained the efficiency down to about 0.3 microns. Labora-
tory tests are now underway to determine if this new 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. Results
of the APS electrotube tests have not been received. None of the other
devices tested had acceptable fine particulate collection efficiencies.
The following devices are now being considered for testing:
0 United McGill—MAFCO ESP
0 Combustion Power—Dry Scrubber
0 Dart Industries—Hydro-Precipitrol Wet ESP
0 Ceilcote Company—Ionizing Wet Scrubber
0 Union Carbide—Petersen Separator
0 Celesco--Low Energy Wet Scrubber
0 Du Pont—Du Pont Scrubber
A University of Washington Charged Droplet Scrubber is being fabri-
cated as a portable unit for evaluation on a power plant. If this unit
shows promise, it will be evaluated on other sources.
Parallel to the field testing effort, a small in-house facility for
testing novel devices is being operated. Currently, a small foam scrub-
ber is being constructed to complement work currently in progress as a
new concept.
HIGH-TEMPERATURE/HIGH-PRESSURE PARTICULATE CONTROL
This program area was added in FY 75 as a result of the critical
particulate and fine particulate cpllection 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 pro-
cesses 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/high-pressure particulate
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collection research and development.
The state-of-the-art of high-temperature/high-pressure participate
collection is very unclear. There is no clear specification of the
degree of participate collection needed by advanced energy processes.
Also, there are no reliable data for the performance of the participate
collection devices proposed by various companies; e.g., granular bed
filters and high-pressure-drop cyclones. There are few data, correla-
tions, 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 as-
suming that either cyclones or granular bed filters will provide the
degree of particulate 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/high-pressure on basic particle
collection mechanisms (literature search funded in FY 75; experimental
study funded in FY 76); and determine the estimated particulate clean-up
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 (Consolidation Coal) for use in particular
energy processes.
IERL-RTP, as part of the Novel Particulate Device Program, is at-
tempting to evaluate either or both the Rexnord or CPC granular bed
filters. IERL-RTP, as part of the New Concepts in Particulate Collection
Program, is supporting work on the previously mentioned high-temperature/
high-pressure particulate collection.
ACCELERATED PILOT DEMONSTRATIONS
This program area is described in more detail in each of the pre-
ceding sections. In general, IERL-RTP has currently funded two pilot
scale demonstrations and will fund one additional demonstration in .FY
76. Although these projects are demonstrations of technology only and
are "pilot scale," it has been customary, where possible, to put them on
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a small source at full scale and thus accomplish a complete process
control demonstration.
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INDUSTRIAL PROCESSES
lERL-RTP's work in the area of industrial processes can be subdivided
into three distinct functional groupings: chemical processes, metallurgi-
cal processes, and process measurements (the last-mentioned applicable to
the entire IERL-RTP program). The following subsections of this report
discuss these groupings separately.
CHEMICAL PROCESSES
IERL-RTP's Chemical Processes activities are grouped into four cate-
gories:
0 Combustion sources.
0 Inorganic material processing sources.
0 Organic material processing sources.
0 Open sources.
Within these four categories are all chemical process activities not
specifically assigned to other IERL-RTP programs. The first three categories
are "point" sources; the fourth category, open sources, consists of "area"
sources. Fugitive emissions from materials handling operations, raw material
and waste storage piles, and agricultural operations are part of this fourth
category.
In order to define control technology development needs for sources in
the four categories, information relating the characteristics of emissions
to their probable impact on receptors must be assessed. Presently, much of
the information 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 decisionmaking,
regarding control technology development needs for specific sources.
Efforts to determine which pollution sources should be characterized
first are complete. The sources were organized into the four categories
previously discussed. A model was then developed to estimate the relative
environmental impact of each source within each category. Factors included
in the model were the pollutant type, the mass emissions, the atmospheric
reactivity or stability of the emissions, number of the source type, the
growth pattern for the industry, the location of the plants, population
densities at the source locations, the relationship between source emissions
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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 environ-
mental impact number. By this means, a priority listing based on relative
potential for adverse environmental impact was developed for the sources
in each of the four categories.
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 fac-
tors 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 are:
Combustion Sources
Coal-fired Utility Boilers
Coal-fired Industrial Boilers
Oil-fired Industrial Boilers
Agricultural Open Burning
Prescribed Burning
Stationary Turbines
Stationary Reciprocating Engines
Inorganic Material Processing Sources
Glass Manufacturing
Barium Chemicals
Fertilizer Mixing
Brink Kilns
Lead/Acid Batteries
Ammonium Nitrate Production
Cotton Gin Operation
Ammonia Production
Organic Material Processing Sources
Acrylonitrile
Asphalt Paving Hot Mix
Surface Coating
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Degreasing Processes
Rubber Processing
Plastic Processing
Phthalic Anhydride Production
PVC Production
Neoprene Production
Textiles
Polyvinyl Chloride
Charcoal Manufacture
Organic Sources
Carbon Black
Maleic Anhydride
Acrylic Acid
Open Sources
Beef Cattle Feedlots
Defoliation of Cotton
Harvesting of Grain
Loading and Transport of Cotton
Handling, Transport, and Storage of Grain
Coal Storage Piles
Transport of Sand and Gravel
Open Mining of Coal
Crushed Stone
Crushed Sandstone and Quartz
Crushed Granite
Crushed Limestone
Coal Refuse Piles
Effluents from each source will be identified and characterized in
terms of emission rates, potential for adverse health effects, and environ-
mental stability. Ambient pollutant levels will be determined for typical
sources by means of accepted dispersion equations. The source distribution
will be presented and related to affected population. Studies of the avail-
ability and performance of viable control technology will be presented.
While the emphasis of future IERL-RTP control programs for industrial
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chemical processes depends largely on the conclusions of the SADs now being
prepared, a wide variety of control activities in chemical processes are
already underway. The goals and status of these varied activities are
described in the following subsections.
Fabricated Metal Products
In the course of manufacturing metal products, conventional procedures
call for the use of large quantities of organic solvents to clean and pre-
pare surfaces for joining and coatings. These solvents are often highly
volatile and can emit large quantities of hydrocarbons into the atmosphere.
A methodical study of this problem began in 1975 with the awarding of a
contract to DeBell and Richardson, Inc., for an assessment of the environ-
mental impact of organic emissions from solvent evaporation sources (the
Hydrocarbon Program of EPA's Office of Air Quality Planning and Standards).
Purposes of this program are:
0 To develop a body of information and data upon which EPA can make
decisions regarding the need for and the feasibility of control
technology to limit emissions of organic compounds from various
industrial surface coating operations.
0 To develop various alternative New Source Performance Standards
limiting emissions of organic compounds and to develop Standards
Support Documents supporting these standards, for various indus-
trial surface coating operations.
The program is, therefore, divided into two phases. Phase I (July
1975 to July 1976) consists of:
0 A review of a number of industrial surface coating operations to
develop all information relevant to emission problems such as in-
dustry statistics, emission sources, quantities of emissions,
emission control techniques, and an initial estimate of emission
control costs.
0 Identification of the technological deficiencies in air pollution
control technology currently in use which restrict further reduc-
tion in emissions, and recommendation of R&D programs that would
produce the greatest improvement in control technology.
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0 Recommendation of various surface coating operations for the
development of Mew Source Performance Standards and Standard Sup-
port Documents in Phase II.
Phase II (July 1976 to July 1977) will consist of:
0 Identification of various alternative New Source Performance
Standards that could be developed for each surface coating operation.
0 Analysis of the economic impact associated with various alternative
New Source Performance Standards on both new and modified industri-
al surface coating operations for which standards are being developed.
0 Analysis of the environmental impact associated with various alterna-
tive New Source Performance Standards that could be developed.
In addition to this general study, a specific process modification is
now being evaluated on a pilot scale by Battelle and Continental Can. This
evaluation measures the hydrocarbon emissions and energy consumption of a
conventional can coating line with those of a coating line employing an
ultraviolet base coat. The goal is to reduce hydrocarbon emissions by 70
percent and energy consumption by 50 percent. A final report on this par-
ticular process should be available in the latter half of 1976.
Petrochemicals
Petrochemical processing includes all industrial processes that use
petroleum as a feedstock. Because of the size and importance of the oil
and petrofuel industries, oil refineries are considered separately later.
Considered here are special multimedia pollution problems from nonfuel uses
of petrochemicals.
ETHYLENE DICHLORIDE (EDC) PROCESSES
Hydrocarbon emissions are the major pollution problem 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 inerts, along with about
0.03 tons of hydrocarbon per ton of EDC, to the atmosphere. EDC production
is now about 5 billion pounds per year.
At present there is no practical way to eliminate the oxyhydrochlorina-
tion vent from existing processes; the gases are too dilute for incineration,
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and the addition of natural gas to make the gases combustible is an extrava-
gance. Furthermore, incineration would form hydrochloric acid which would
have to be controlled by scrubbing.
The objective of a project now underway by Allied Chemical is to demon-
strate that emissions can be reduced by at least 90 percent from the levels
encountered with typical existing processes. The modified process employs
recycling of reactor exit gas, oxygen feed, and whatever additional proc-
essing steps are determined to be necessary to control build-up of byproducts
in the recycle stream. The modified process is to be economically competitive
with present day processes. The process performance is being evaluated on
a pilot scale so that a preliminary study of technical and economic feasi-
bility can be carried out.
Successful completion of the recycling system test (1975) will be fol-
lowed by a test program (estimated completion late in 1976) to demonstrate
an instrumental control system that will provide on-stream reliability with
comparable manpower equivalent to typical 1974 operation of EDC plants.
VINYL CHLORIDE (VC)
An activity carried out during 1975 was a sampling of the interiors
of eight different models of new U.S. automobiles in order to measure VC
concentrations 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, should be available in February 1976.
POLYCHLORINATED BIPHENYLS (PCBs)
This effort makes use of the special expertise and equipment available
at Envirogenics Systems Division of the Chemical Process Plants Company to
extend the application of a metal/metal couple reduction process to the
treatment of another EPA "toxic/hazardous" material, PCB. The work is ex-
pected to proceed rapidly from laboratory scale through bench scale opti-
mization (6-inch diameter, 1 to 3 gallons per minute). The process will be
optimized for treatment of PCBs in: (1) PCB manufacturing effluent; (2)
PCB user effluent (e.g., electric transformer and condenser manufacturer,
industrial HC1 compressors using PCB as sealant, heat exchangers using PCB
coolant); and (3) treatment of accidental discharges and leachates from
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areas where PCB-containing equipment has been dumped, is being stored, or
is being operated.
In addition to the above PCB work, the reduction process will be
screened for the first time for its effectiveness in treating various
light-end chlorocarbons often found industrially with PCBs; e.g., ethylene
di- and tri-chlorides, carbon tetrachloride, and chloroform.
The feasibility project is scheduled for completion in January 1977,
after which a demonstration model will be built, if warranted.
Inorganic Chemicals
Inorganic chemical processing, as discussed here, includes three major
investigations: control of tail gas from nitric and sulfuric acid plants,
and control of mercury emissions from chlor-alkali plants. In each inves-
tigation, the Battelle-Columbus Laboratory is evaluating the technical and
economic feasibility of using the appropriate Union Carbide PuraSiv molecu-
lar sieve system to control the specific air pollutant to the following
goals:
0 PuraSiv M--to reduce NO emissions from nitric acid plants to 50
A
ppm or less.
0 PuraSiv S—to reduce SCL emissions from sulfuric acid plants to
100 ppm or less.
0 PuraSiv Hg--to reduce Hg emissions from chlor-alkali plants to
60 ppb (by volume) or less.
Conclusions will be drawn after an engineering analysis of data avail-
able from the open literature, from molecular sieve vendor(s), and from
test data acquired in the field by monitoring the three control systems.
Field testing is being carried out at the following locations:
0 Nitric Acid Plants--Holston Army Ammunition Plant, Kingston,
Tennessee (tests by Department of the Army, Picatinny Arsenal).
--Hercules, Bessemer, Alabama (tests by
Engineering Science).
0 Sulfuric Acid Plant--Coulton Chemical, Oregon, Ohio (tests by
York Research).
0 Chlor-Alkali Plant--Sobin Chemical, Bangor, Maine (tests by
Commonwealth Laboratories).
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All tests and demonstrations should have been completed by December
1975 with final reports available shortly thereafter.
Agri cultural Chemi cals
Pollution problems arising from the production of agricultural chemi-
cals involve both air and water pollutants. They are associated with the
production of fertilizers as well as with the production of pesticides and
herbicides.
FERTILIZER
lERL-RTP's chief air pollutant activity related to fertilizer produc-
tion is a study to determine the extent to which gypsum ponds are sources
of atmospheric fluoride emissions from the wet process phosphoric acid and
to define control techniques for reducing fluoride emissions from gypsum
ponds. An emission factor for fluoride from gypsum ponds will be derived
from this study by evaluation of: previous studies in the literature, gyp-
sum pond chemistry, and the description of the process and the identifica-
tion of the sources of fluorides to the pond. Fluoride concentrations in
the vicinity of a typical gypsum pond will be calculated from the emission
factor developed.
Effects of various control strategies are being evaluated with respect
to reduction of gypsum pond fluoride emissions and costs. Techniques con-
sidered are control at the pond, in-process modifications, and pretreatment
of the phosphate rock. A final report on this task will be issued early
in 1976.
In a jointly funded project with the State of Florida's Department of
Pollution Control, IERL-RTP is developing technology to minimize both the
production of slime ponds and fluorine air emission from the phosphate
manufacturing industry. The goal is to avoid the proliferation of slime
ponds.
A dry-mining/beneficiation/calcination/acidification process was pro-
posed. The dry-mining process proved not to be technically feasible be-
cause of aluminum contamination in the product phosphoric acid and because
of filtering problems.
Studies of effluent cleanup from fertilizer production were also
assumed by IERL-RTP during 1975 in another jointly funded (with Farmers
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Chemical Assoc., Inc.) project at the former Athens Field Station.
The objective of this project is to: evaluate all conventional and
several experimental methods for inorganic nitrogen removal from water,
determine the optimum process(es), and demonstrate at full scale on waste-
water from a balanced-N fertilizer production complex; i.e., one contain-
ing ammonia, urea, nitric acid, and ammonium nitrate units. In the demon-
stration model, high ammonia concentrations are to be reduced by air
stripping. Oxidation of residual ammonia to nitrate is accomplished by
trickling filter biological action using sewage as the carbon source.
Denitrification of nitrates is accomplished by anerobic 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 is also to be established. Advanced physico-chemical
processes (such as ion exchange, reverse osmosis, electrodialysis, and
mixed-salt precipitation) 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 performance
are still underway. The complete air/water impact of the system is still
to be determined.
A third related project is beginning in Yugoslavia. An air dispersion
and transport model for fluoride-containing particulates from a TVA-type
granulation plant is to be postulated and tested via actual calibration
data at the FMK, Novi Sad plant site and its surroundings. Stock testing
(source quantification) as a function of production rate and feed stock
will be included. Use of Autoclave (hydroclave) separation in series with
a phosphoric acid scrubber to reduce these emissions will be tested and
quantified. Double liming treatment of fluoride washwaters will be in-
vestigated and subsequent water reuse in the scrubbers evaluated. A final
report is scheduled for mid-1978.
In a jointly funded program with the Louisiana Chemical Association,
IERL-RTP plans to demonstrate at full scale a steam stripping process for
treatment of ammonia plant condensate. Ten ammonia manufacturing companies
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are developing the new technology required to reduce ammonia in existing
plant effluents by stripping the contaminants and reinjecting them into
the process. Stripped condensate can then be recycled as boiler feed
water. When completely satisfactory, this new technology will reduce
process effluent to zero discharge from this source, while avoiding air
pollution from stripper overhead venting.
Excessive costs, particularly in energy, thwarted the initially pro-
posed solutions; however, the future of this research is still open.
A second resource extraction development in fertilizer production is
a program to develop and demonstrate at pilot scale the optimum process
flow sheet and plant design for making a high analysis, slow release
N-P-K-S granular fertilizer with "zero" pollutant discharge. Its princi-
pal feedstock is industrial byproduct ammonium sulfate—itself a major
pollutant threat from any industrial operations. In addition to the ob-
vious environmental and cost benefits derived by using a major industrial
waste (i.e., ammonium sulphate), the production process design for this
new product will emphasize environmental control at all stages. Omission
of the conventional rock acidulation step will eliminate granulation plant
fluorine emissions. Exploitation of favorable heat and water balance will
be evaluated for elimination of any effluent other than product. Corrosion
protection, instrumentation, and novel process equipment requirements will
be assessed with respect to product economics. Full-scale process design
specifications will be established for both new units and conversion of
existing outdated granulation plants.
PESTICIDES
In a project jointly funded with Velsicol Chemical, IERL-RTP is cur-
rently developing, demonstrating, and evaluating two processes for nonbrine
chlorocarbon pesticide wastewater. The demonstration tests involve the
heptachlor and endrin wastewater effluent from Velsicol's Memphis, Tennessee,
plant. The processes of choice are resin adsorption removal and in situ
metal/bimetal catalytic reduction (dechlorination). Rohm and Haas XAD-U
resins are used to remove heavy-end chlorocarbons from the wastewater.
Solvent regeneration of the resin permits reuse of resin, solvent, and
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some product recovery. Metal reduction focuses on the use of copper-
catalyzed iron powder to dechlorinate/dehydrochlorinate the light and
heavy components alike, reducing waste toxicity and bioaccumulative prop-
erties. 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 January 1977.
Over the past several years the Envirogenics Systems Division of
Chemico Process Plants has been developing processes for treating various
chlorinated pesticide wastewaters. The compounds tested included DDT
(isomers), heptachlor, endrin, chlordane, and toxaphene. The candidate
processes investigated included catalytic reduction, solvent extraction/
condensation, UV photolysis, and promoted photolysis.
Targets for the candidate treatment processes were a 99 percent or
greater conversion of DDT (and major isomers) to products of demonstrably
reduced hazard to the environment, and 95 percent conversion for toxaphene
and chlordane.
These goals have been met and a demonstration grant will be awarded
to Montrose Chemical so that their DDT plant at El Monte, California, can
be used by Envirogenics to apply this technology to a DDT waste stream.
The waste stream will be contacted with heptane in a high shear pump to
solvent-extract the DDT. Solvent recovery will be by distillation with
the residues at the bottom of the still being polymerized into an insolu-
ble waste via A1C13 Fried!-Crafts synthesis. The waste will be removed
and buried in a landfill.
A third major pesticide program being studied by Repro Chemical is
the conversion of chlorocarbon and pesticide wastes by complete or par-
tial chlorolysis. The technical feasibility of the process is demonstrated;
the major question now is one of economic feasibility. Under the present
contract Repro is studying the economic impact of implementing chlorolysis
on a large scale such as a regional chlorocarbon disposal ^facility.
Assessment of such parameters as the magnitude of the potentially
available U.S. organic wastes suitable for chlorolysis feedstock and the
markets for the chlorolysis conversion products (carbon tetrachloride,
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carbonyl chloride, and anhydrous hydrochloric acid) will determine the
most practical chlorolysis process and a specific design will be formu-
lated in conjunction with the herbicide activities of the Hoechst-Uhde
Corp.
With partial IERL-RTP support, Dow Chemical plans to demonstrate at
full scale (200 gpm) a UV chlorination process to remove acetic acid from
carbon-bed-treated phenol and/or 2,4-D manufacturing waste brines. Eco-
nomic and design data are to be catalogued, including the effects of light
placement, flow rate (residence time), and chlorine and chloride ion con-
centration. Also to be studied are: material and energy balances—par-
ticularly with respect to byproduct methyl chloride conversion and recovery
from the vent gas; corrosion protection and full scale instrumentation
requirements; and automated operation potential. Brine quality and evalu-
ation as caustic cell feed will also be monitored. Laboratory scale tests
to define the kinetics, products, and optimum reaction conditions for other
organic acids (such as glycolic, lactic, chloroacetic, propionic, butyric,
and chloropropionic) will also be performed. Phenol (chlorophenol) plant
waste brine from which the solids and organic "heavies" have been removed
by carbon are to be fed to a two-stage UV chlorination reactor. Adjust-
ment of pH and addition of chlorine will produce C02 plus a volatile or-
ganic chloride which is vented from the reactor. Excess chlorine in the
vent gas is separated from the organo-chloride and C02 and recirculated
to the reactor.
HERBICIDES
Bench-scale tests have demonstrated the ability of the chlorolysis
process (Hoechst) to convert Dioxin-contaminated, high-sulfur Herbicide
Orange (alone and in blends with typical U.S. chlorocarbon residues) into
recoverable product.
These tests showed that U.S. vinyl chloride, chlorinated solvents,
and vinylidene chloride residues are readily chlorolyzed to carbon tetra-
chloride and hydrogen chloride. Orange chlorolyzes adiabatically but its
high sulfur content causes severe, but local reactor corrosion. Use of
a segmented reactor combined with feed blending suggests that a regional
plant (capable of handling industrial residues plus Orange and/or other
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military pesticides) is feasible. The purpose of the present investiga-
tion is to provide a completely integrated regional conversion plant de-
sign and economic feasibility study for a 25,000 ton/year chlorocarbon
residue feed rate plant in cooperation with Repro Chemical. This design
should be ready during the first half of 1977.
Food Products
The problem addressed by IERL-RTP in the food rendering industry is
control of odors. In a program jointly funded with the Fats and Protein
Research Foundation, IITRI began the design and evaluation of a scrubber
design condition that will effectively remove rendering odors from plant
ventilating air and process air. During the first stage of the program,
a horizontal 3-stage spray scrubber which was tested and evaluated removed
92 percent of the initial odor concentrations for a cost of 18<£/l000
cfm-hr.
The research effort was expanded to include development of a scrub-
ber system to remove odors from high intensity cooker streams (10,000 to
70,000 odor units). During the initial testing of a packed scrubber for
high intensity odors, sufficient data were obtained for preliminary design.
This design should be verified by January 1976.
Combustion
Assessment and definition of the problem of emissions from combustion
sources is a major concern to IERL-RTP. In addition to the Source Assess-
ment Documents (SADs) being prepared for combustion sources by Monsanto
Research, independent environmental and emissions assessments of conven-
tional combustion systems are being prepared for IERL-RTP by GCA.
The GCA emission assessments will specify the potential air, water,
and solid waste pollutants associated with each conventional combustion
system on a unit operations level (e.g., fuel storage, fuel combustion,
waste disposal). This includes specifying the physical and chemical state
in which the pollutant is emitted. The emission rates of the pollutants
will be determined by the most appropriate means, such as field sampling,
material balance calculations, or manipulation of existing data.
Preliminary environmental assessments will establish an identity
matrix across air, water, and solid waste pollutants that will: summarize
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ongoing and planned work in conventional combustion environmental assess-
ment; list the known pollutants being emitted from each combustion system
studied; rank pollutants according to the expected intensity of their im-
pact on the environment; delineate the established or potential impact in
the areas of air, water, and solid waste pollution; and define the major
gaps in the pollutant data base by combustion system type and operating
parameters deemed relevant to the composition and quantity of pollutant
emissions.
The goal of these detailed analyses is to clearly define the signifi-
cant emission sources that require control, permitting investment of the
limited control technology funds in those problem areas that will provide
the greatest return in terms of improved air quality. Again, the major
impact of these assessments will be reflected in IERL-RTP programs of
future years.
IERL-RTP1s presently active programs in emissions from combustion-
related processes range from evaporative cooling devices to industrial
and utility boilers.
MECHANICAL COOLING DEVICES
Interest in the use of cooling towers, power spray modules, and
related cooling devices at locations with available brackish or salt water
has created a need for data to quantitatively evaluate the air pollution
emissions from this type source. In August 1973, IERL-RTP initiated a
program at Florida Power and Light's Turkey Point facility to characterize
emissions from a mechanical draft cooling tower and power spray modules
circulating salt water. A major problem with such evaporative cooling
devices is the entrainment of small particles having approximately the
mineral content of the circulating water and the transport of these par-
ticles by the warm, moist, rising plume into the ambient atmosphere.
Deposition of these particles onto the surrounding biota may generate
undesirable environmental effects.
At Turkey Point, IERL-RTP participated in studies conducted by the
National Thermal Pollution Research Programs (NTPRP) and the former
National Ecological Research Laboratory (NERL) at Con/all is, Oregon.
The overall problem was divided into three segments: characterizing
the drift sources, characterizing the drift transport, and comparison of
ambient deposition with ambient-plus-source-drift residue deposition.
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Ambient or background salt levels were measured so that salt drift
contributed by the devices could be determined. Characteristics (e.g.,
size, number of particles, mass) of the drift from the devices were deter-
mined. Meteorological data were collected during the study. Statistical
analysis of the data is being accomplished by Adapt Corp., Reading, Massa-
chusetts, under the sponsorship of the NTPRP.
Preliminary analysis of the data indicates that the air particulate
samplers were located such that statistically valid differences in salt
concentrations could be detected near (200 to 300 meters) the cooling
devices. As expected, meteorological conditions have an important impact
on the distribution of salt particles.
HAZARDOUS AND TOXIC EMISSIONS FROM INDUSTRIAL AND UTILITY BOILERS
Boiler flue gas has been identified as a major potential source of
both gaseous and particulate toxic and hazardous emissions. Under IERL-
RTP sponsorship, the Midwest Research Institute (MRI) has developed a
comprehensive plan for measuring hazardous constituents in representa-
tive utility boiler exhaust streams.
This plan has been implemented on a full scale utility boiler, TVA's
Widow Creek steam-electric power plant. In addition to providing data on
hazardous pollutants, the study also checked the reliability and accuracy
of the sampling and analysis methods, as detailed in the final report now
available.
Refineries
Petroleum refineries consist of a complex of physical and chemical
transformation 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 requiring air, solid, or water effluent control, IERL-
RTP is now carrying out a detailed assessment of the environmental efflu-
ents associated with oil refining. The study will quantify the potential
for emissions in each step of the physical and chemical transformation of
petroleum. Particular attention will be given to "fugitive" or previously
unaccounted for emissions, to operations expected to utilize heavier feed-
stocks, and to practiced control technology. The assessment includes a
field sampling program to verify the quantified emissions identified in
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the study and will lead to a guideline document for determining the en-
vironmental impact of existing and new petroleum refineries.
From this assessment and guideline document, the major control program
emphasis of future years will be defined. Ongoing investigations are de-
scribed in the remainder of this section.
SULFUR OXIDES CONTROL
Petroleum refineries are a major industrial emitter of sulfur oxides
(SO ). In 1969 the estimated SO emissions from 262 refineries (charging
X X
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 SO emissions from petroleum refineries con-
A
tinues to grow. IERL-RTP is therefore vigorously seeking methods for
suppressing SO emissions from petroleum refining operations.
X
Four approaches to SO control currently exist for petroleum refin-
X
eries: desulfurization of flue gases, desulfurization of in-process feed-
stocks, desulfurization of the whole crude feedstock, and combinations of
the above.
The technology required for each approach has been developed to dif-
ferent 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 inade-
quate technology need to be reviewed. IERL-RTP, with the assistance of
the American Petroleum Institute, has initiated a program to quantify the
impact of the alternative approaches, based on up-to-date technology and
economics.
Under this program, Arthur D. Little has developed a linear program
model for petroleum refining and is calibrating it against confidential
industrial and Bureau of Mines data for the year 1974. A base case and
two levels of SO control scenarios have been run for three time periods
X
(1977, 1980, 1985). The model can choose from among the four basic con-
trol approaches for reducing SO emissions (feed desulfurization to flue
X
gas scrubbing). For each specific process sequence identified, the asso-
ciated incremental economic impact is calculated. The project will result
in reports that will show possible petroleum processing configurations
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and costs. Some of these reports will be issued in 1976.
AUTOMOBILE FILLING STATION CONTROL
The objective of this study, initiated late in 1975 in response to a
request from EPA's Office of Air Quality Planning and Standards, is to
identify and determine the extent of hydrocarbon build-up on the charcoal
beds used to control gasoline vapors in service stations. Any decrease
in charcoal bed working capacity because of the build-up of hydrocarbon
"heavy ends" will be identified. The investigation will be carried out
as a laboratory or small pilot scale project.
Construction
Two construction-related IERL-RTP projects, recently transferred to
other EPA organizations, are summarized below.
Previous IERL-RTP studies showed that the major sources of fugitive
asbestos emissions are manufacturing waste piles and processing lines
rather than mining/milling operations. In a follow-up study, IITRI field
tested various control options for the abatement of asbestos emissions
from material transfer operations and wind erosion of the waste storage
piles created in the manufacture of asbestos cement products. Both poly-
meric coatings and vegetative stabilization are initially very effective
in reducing wind erosion of asbestos cement wastes. The long-term stability
and costs of each of these surface treatments are still being assessed.
Follow-on work will be out of EPA, Cincinnati.
Under a separate contract, IITRI studied the occurrence and properties
of various amphibole minerals in the Silver Bay area of Minnesota: from
this ore body, IITRI prepared respirable-sized samples of amphibole asbes-
tos to be used in health effects studies. Veins of very friable asbestos
were found in Reserve Mining's Peter Mitchell Pit: the conclusion is that
their presence will contribute substantial asbestos emissions to the air
during any subsequent mining operations.
The health effects samples will be used by EPA's Health Effects Research
Laboratory to develop better asbestos standards. Follow-up work under this
contract will be managed by HERL.
Textiles
Textile manufacturing processes generate voluminous wastewaters which
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are environmental polluters if not treated. If they can be reused, the
potential for lower manufacturing costs becomes large. A number of proj-
ects, 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.
Owens-Corning Fiberglas in Toledo is demonstrating, first in pilot
scale and then in full plant scale, the complete recirculation and reuse
of a complex 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 in-plant
water uses, (2) additional local water conditioning and recycle facilities
for cooling, scrubbing, and chain washing, and (3) improved wastewater
treatment so that remaining wastewater may be reused for nonprocess uses.
LaFrance Industries in LaFrance, South Carolina, is assessing the
technical feasibility of producing a reusable effluent from textile waste-
waters by applying hyperfiltration. The objective of this project is to
demonstrate pilot plant reverse osmosis treatment of dye house wastewaters
followed by reuse of both the resulting retentate and permeate. Cellulose
acetate and dynamic membrane systems will be evaluated for the separation
of dissolved solids and color concentrates. Engineering and economic
analyses will be performed for all aspects of the project, including reuse
in standard dyeing processes.
The South Carolina Textile Manufacturer's Association in Columbia is
also assessing the application of hyperfiltration technology to treat the
wastewaters, for eventual reuse, from eight textile plants in that state.
The textile plants represent most of the EPA dyeing and finishing guide-
lines categories. The effects of system pressure, fluid circulation veloc-
ity, and percent water recovery as well as the major economic parameters
on direct reuse will be evaluated. The reuse of the separated parts of
the waste streams will be tested in the industrial quality control labora-
tory at each site. In addition, a treatability study will be performed on
the concentrate from the hyperfiltration units to evaluate alternative dis-
posal methods.
J. P. Stevens & Co. in Greensboro, North Carolina, is evaluating treat-
162
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merit sequences for cleaning textile wastes including biological treatment,
multimedia filtration, and activated carbon/ion exchange. A key feature of
the research 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.
Beaunit Fibers Corporation is biologically treating nylon 6,6 waste-
waters using oxygen enriched off-gases (40 percent available oxygen) from
the nylon manufacturing process. The oxygen aerated activated sludge sys-
tem is monitored to determine raw waste characteristics, process kinetics,
and economic data. This unique system demonstrates treatment of nylon
wastewater and utilization of byproducts to achieve pollution abatement.
Clemson University is surveying the textile industry to determine the
quantity of energy that could be made available by recycling hot water in
current dyeing and finishing procedures. The project includes the evalua-
tion of the application of high temperature hyperfiltration membrane tech-
nology to a variety of high temperature, point source, process effluents.
Membrane performance will be evaluated in on-site plant scale experiments
for several point sources selected for maximum energy and/or resource
conservation through direct recycle.
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.
Canton Textile Mills in Canton, Georgia, is demonstrating biological
oxidation of textile finishing wastes supplemented by flue gas neutraliza-
tion of the waste stream for control of pH, and fly ash adsorption for
color removal. The design parameters for the pretreatment and tertiary
treatment processes were determined by pilot scale operation of the proc-
esses. The neutralization and color reduction processes are incorporated
into an existing bio-oxidation system at full-scale operation. The opera-
tion of a bench pilot scale electrochemical system was included'for recovery
of the dyeing chemicals. A final report of this operation is now available.
The American Textile Manufacturing Institute (ATMI) will cooperate
with EPA by participating in a court-ordered study to evaluate the treat-
163
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ment efficiency of technological processes defined by EPA as BATEA for the
textile industry and to evaluate the economic achievability and impact on
the industry resulting from the application of these technologies. The work
will be performed by a mutually agreed upon consultant under joint direction
of ATMI and EPA. The actual investigations will be carried out through the
use of tv/o mobile pilot treatment units. Approximately 20 plants will be
investigated. These 20 plants will be selected from among plants already
achieving the Effluent Guidelines Division's best practical control tech-
nology currently available (BPCTCA) level. The treatment processes will
include chemical treatment (including carbon adsorption) and multimedia
filtration. An economic study will be conducted by a mutually agreed upon
consultant evaluating the data collected in the pilot treatment study.
The Institute for Meteorology and Water Economy, Krakow, Poland, is
evaluating the effectiveness and economics of several tertiary treatment
processes/operations as applied to biologically treated municipal/textile
wastewaters. Seven unit processes are being investigated separately and
in various combinations including reverse osmosis, carbon adsorption, co-
agulation, multimedia filtration, ion exchange, catalyzed chlorine oxida-
tion, and ozone treatment. The information being generated will be useful
for pollution abatement not only in the United States but also in the
international community.
Blue Ridge Winkler Textiles in Bangor, Pennsylvania, is running a
full-scale demonstration of the operation of a newly constructed 750,000
gpd wastewater treatment plant for textile dye and finishing wastes. The
treatment system includes the following processes: equalization, pH and
nutrient control, activated sludge including secondary clarification, also
coagulation consisting of rapid mixing, flocculation, and clarification,
chlorination, and sludge dewatering. The systems have been operated for
the purpose of documenting and evaluating the wastewater and unit process
characteristics. A final report is now available which contains a detailed
summary of all data and engineering studies.
Hoi listen Mills, Inc. in Kingsport, Tennessee, is investigating on a
pilot scale the treatment of cotton textile waste by enzymes and a high
rate trickling filter.
In a novel approach based on a process modification, Auburn University
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is evaluating the impact of the use of solvent-based sizing techniques
on textile plant effluent parameters. The project includes economic and
technical evaluations. 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) evalu-
ate 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 dis-
charge quality and quantity, and (7) evaluate the effect of solvent substi-
tution on air pollution and ambient air quality.
Miscellaneous Industries
This section describes the remaining active projects of lERL's con-
trol program related to industrial chemical processing. Each project is
discussed in a separate subsection.
ASPHALT ROOFING
The objective of this project (at the Midwest Research Institute) is
to evaluate the technical and economic feasibility of control methods that
can achieve 99 percent reduction of particulate, hydrocarbon, and POM emis-
sions from the blowing stills and saturator operations used in the asphalt
roofing industry.
The approach to be used in accomplishing the objective of this task
consists of three subtasks:
0 Surveying the asphalt roofing industry, surveying the literature
and published reports, contacting equipment manufacturers to identify ex-
isting and potential control methods, and compiling information and data
on those methods.
° Evaluating the technical and economic feasibility of achieving 99
percent reduction of particulate, HC, and POM emissions from blowing stills
and saturator operations using the technology identified in the previous
subtask.
0 Recommending the most feasible control process(es) and preparing
estimates for conducting a demonstration program or, where necessary,
preparing a research plan for developing the technology to the point where
a demonstration program is warranted.
165
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A final report was expected in December 1975.
GLASS MANUFACTURE
Glass-melting furnaces are considered a potential source of fine
particulate, sulfur oxides, nitrogen oxides, and other gases that are
generally considered undesirable atmospheric emissions. In 1971, the
glass industry ranked ninth in total fuels purchased by manufacturing
industries. Two-thirds of the energy utilized by the glass industry was
consumed by the high-temperature melting furnaces in which raw materials
are converted into molten glass. With most high temperature operations,
the thermal efficiency is low, usually less than 35 percent. The product
of this work will be the development of technology that reduces air emis-
sions and improves the energy utilization of the glass-melting furnace.
The purpose of this project, therefore, is to develop control tech-
nology for the abatement of air emissions from glass-melting furnaces.
A secondary objective is to improve the thermal efficiency of the furnaces
and hence to conserve energy. The ultimate goal of this program is to
demonstrate the technical and economic benefits of this technology on a
commercial glass-melting furnace within the industry.
The work will be initiated in one of four phases:
0 Laboratory/bench scale process development.
0 Pilot plant development.
0 Construction, startup, and performance testing of full-scale unit.
° One-year demonstration of full scale unit on a commercial glass-
melting furnace.
The contract for this work is expected to be signed by April 1976.
ASBESTOS MATERIALS FABRICATION
Control of asbestos during manufacturing processes centered on bag-
house studies in 1975. IITRI conducted a test matrix of operating con-
ditions versus efficiency of asbestos removal. The objective of the test
program was to define and document the optimum operating mode, the highest
control efficiency possible, and the incremental cost of achieving improved
performance. Since EPA has not established a safe exposure level for asbes-
tos, this program was slanted at defining control benefit as a function of
cost, as opposed to achieving a particular targeted control efficiency. A
draft final report has been completed and should be available early in 1976.
166
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FLARE SYSTEMS
Flaring, while a relatively cheap method for disposing of certain in-
dustrial 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 provide the background to establish the base on which addition-
al work can be built in order to make flaring an economical and environ-
mentally sound method of waste gas control.
VEGETATIVE STABILIZATION OF MINERAL WASTE HEAPS
This project, conducted at the Research Triangle Institute, consisted
of an evaluation of the use of vegetation as a method for controlling fugi-
tive dust emissions from manmade 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 the Great Plains and Rocky
Mountains of the United States, they constitute a significant source of
fugitive 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 addition, emission of a toxic substance characteristic 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 revegetation of mineral waste piles were deduced.
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
surefire procedure can be specified as to optimum procedures for •
any given waste in a specific area.
0 Virtually any mineral waste pile can be stabilized with vegetation,
given enough time and resources; the trick is to know when it is
167
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economically reasonable to proceed with a vegetative control meth-
od and when it is foolhardy.
0 Little quantitative data exist by which to measure the magnitude
of the fugitive dust emitted by mineral waste piles or to assess
the improvement in air quality resulting from vegetative stabili-
zation.
GUIDELINES FOR ENVIRONMENTAL ASSESSMENT OF ENERGY SYSTEMS
To standardize the preparation of environmental assessment documents
in the general field of energy systems, GCA Corporation, under IERL-RTP
contract, prepared a guideline document containing, in a unit operations
format:
0 A description of process operations involved.
0 A definition of the potential environmental impact areas that need
to be addressed.
0 The methodology for determining the magnitude of the impact for
each energy system.
0 Procedures for conducting environmental assessments.
The guideline document enumerates:
0 Specific methods that can be used when conducting environmental
assessments.
0 Criteria to be used in assessing the magnitude of environmental
impacts.
0 The methodology for determining potential interactions between
the unit operations that may result in modified environmental
impacts.
0 Environmental impacts of pollution control systems associated
with any unit operation.
This guideline document is being field tested by Dow Chemical and
Lockheed. Dow is using it to prepare environmental assessments of geo-
thermal and power park energy systems. Lockheed is using it to prepare
environmental assessments of hydrogen combustion, magnetohydrodynamics,
and coal liquefaction. The experiences and problems of both contractors
in using the guideline document will assist in its modification and
improvement.
168
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METALLURGICAL PROCESSES
During 1975, EPA's Office of Research and Development underwent
a major reorganization. The reorganization resulted in lERL-RTP's
divesting itself of the non-ferrous metallurgical air pollution pro-
gram, but retaining the ferrous metallurgical program. In addition,
the ferrous metallurgical program became multimedia.
Ferrous Metallurgical Processes
The ferrous metals industry converts iron ore and scrap iron into
useful iron and steel products. 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 mixture is blown with oxygen which burns the carbon) to
produce steel. In the basic oxygen steel process, the carbon level is
reduced to the required level, impurities are removed, and alloying
agents are added. (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 roll-
ing 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
mi nip!ants, scrap steel is melted in electric arc furnaces with little .
or no refining, then rolled and formed into simple shapes (e.g., con-
create reinforcing rods) to meet local marketing needs. Other small
iron and steel plants melt scrap in cupolas or electric resistance
169
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furnaces. The molten iron and steel at these foundries is cast into
desired shapes.
Studies, started in 1968, have shown that atmospheric emissions
in the iron and steel industry are quite large and originate from a
multiplicity of sources.
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 is now expanding
its outlook—initiating projects in other areas of the industry, in
addition to cokemaking.
IERL-RTP's major ferrous emission control projects are related to:
the preparatory area of mining, beneficiation, and pelletizing of iron
ore; coke ovens; sinter plant windboxes; basic oxygen process (BOP)
furnaces; and iron foundry cupolas.
MIMING, 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 approximately 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.
A 1-year contract was let in July 1975 to Midwest Research Insti-
tute 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, beneficiation, 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
170
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CRUSHING PLANT
I COARSE ORE BINS
FINE ORE BINS
BLASTING LOADING HAULING
GYRATORY
3k CRUSHERS
CONE
CRUSHERS
% i»ROD MILLS
CONCENTRATE THICKENERS *
DISC FILTERS
VIBRATING
SCREENS
CONCENTRATOR
ADDITIVES
AGGLOMERATING PLANT
BALLING DRUMS
FINISHER
MAGNET
SEPARATORS
ROUGHER
MAGNETIC
SEPARATORS
CONCENTRATE
BINS
CLEANER MAGNETIC SEPARATORS
I TO TAILING
I DISPOSAL
AREAS
TAILING THICKENERS
RECOVERED
WATER
FURNACES
,JT OR KILNS
HYDRO SEPARATORS
TO STEEL MILLS
Mining, benefication, and pelletizing operation.
-------
research, development, and/or demonstration projects to reduce emis-
sions from those sources determined to be most critical.
The contract effort to date has been to accumulate data by litera-
ture search, by talking with industry and government personnel, and by
plant visits. Major effort has been on source identification and find-
ing source test data, noting plant-to-plant similarities and differ-
ences, and discussing with plant personnel the control devices attempted
on various process points and their reasons for selection of one device
over others.
The effort for these sources may ultimately be expanded to in-
clude water pollution aspects of the program.
STEELMAKING
Steelmaking processes and material flow patterns are shown below.
Pollutant discharges from the various processes are also shown below.
Coke Oven Emission Control
Control of emissions in cokemaking is a third major IERL-RTP con-
tribution to the iron and steel industry (see figure below). It is the
process which produces the most air pollution 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. It is expected that IERL-RTP's present
prototype demonstration will permit reduction of these pollutants by
90 percent.
Smokeless Coke Charging. IERL-RTP and the American Iron and Steel
Institute (AISI) have funded a demonstration for controlling coke oven
charging emissions, results of which can apply industrywide. Construction
of the demonstration unit, completed in February 1972, was followed by a
production operation and component-testing/reliability phase that was
completed in December 1973.
Coal, charged into a coking oven, is usually dropped from a por-
table hopper through openings in the top of the oven. The charged
coal, upon contacting the heated oven walls, starts to emit large
172
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jl
-RECOVERED FINES FROM
PARTICULATE CONTROL EQUIPMENT.
MILL SCALE
ORE
SINTER
STRAND
SINTER ^
PELLET&7
wnc. ^
PELLETS ^
ORE
YARD
f rtuutii,
\ LUMP ORE./
7'
COAL ^
COAL
YARD
COAL
COKING
FACILITY
1;
y
•x]
CO
PURCHASED,
SCRAP
TO SINTER
PLANT
B. F. GAS
CONVENTIONAL
INGOT
CASTING UNIT
1
CONTINUOUS
CASTING
BILLET UNIT
CONTINUOUS
CASTING
SLAB UNIT
|l s!4 Si I
I!i3l2 llS
Ul|p ==|UJ p- (0
|!g Ills §'§
TO PRIMARY
BREAKDOWN
TO PRIMARY
BREAKDOWN
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
->
i
FROM INGOT
CASTING
FROM CONTINUOUS
BILLET CASTING
^
— ^
h
U *
^ HOT S
r MIL
FROM CONTINUOUS
SLAB CASTING
6
PICKLING
AND
OILING
MILL SCRAP
HEAVY STRUCTURALS
AND RAILS
BAR AND ROD
SEAMLESS PIPE, TUBE
WELDED PIPE
DIRECT SHIPMENTS OF INGOTS, SLABS
BILLETS, BLOOMS
HEAVY STRUCTURALS,
RAILS
fc NAILS AND WIRE
WIRE , PRODUCTS
I
BARS,LIGHT STRUCTURA!
-> INCLUDING REBAR,
WIRE RODS
COLD FINISHED
BARS
COLD REDUCTION
AND FINISHING
PLATE MILL
GALVANIZING
TIN PLATING
AND OTHER
PLATED PRODUCTS
SEAMLESS PIPE,
TUBE
WELDED
HOT ROLLED
SHEET AND STRIPS
GALVANIZED PRODUCTS
TIN AND OTHER
PLATED PRODUCTS
COLD ROLLED SHEET
». AND STRIP, BLACK PLATI
*• PLATE
Iron and steel industry unit operations (sheet 2 of 2).
-------
j Fugitive ~)
Fine Particulates,
Hydrocarbons,
Carcinogens, CH,
NH_, Smoke
! Emissions <^ ,,„ T ,. . , ,
•— — -t — —-j + From Individual
processes
tn
Fine Particulates,
S02, F, Cl,
Volatilized Oil
L.c:^SW SINTER
PLANT
- Charging
- Leaking door seals
- Pushing
- Quenching
COKING PLANT
Excess NH^ Liquor
light oil recovery
wastes quench water
overflow waste water
coke wharf
en
-P
c
ro
o
a,
(0
U-i
- O
QJ
M
3
4-1
a,
us
u
Fine Particulates,
Fume
B.F. Gas
Fine Particulates,
N-, CO, CO , H.O,
HCN ^ i
CAST
HOUSE
Cooling Water
(once through)
Granulation!
Fine Particulates
C02, S0x, N0x, ZnO,
Fluorides
OPEN
HEARTH
FURNACE
BASIC
OXYGEN
FURNACE
Scrubbing Water
High Dissolve
Solids
1
SLUDGE
Fine Particulates
Fume, Smoke, CO,
C02, N02, ZnO, Oil
Vapor
Scrubber water,
phenols, solids,
fluorides-, etc.
Sludge
-*• SOLID DISPOSAL
*• SOLID DISPOSAL
Fine Particulates
"Kish" Fume, CO,
JT-\—| Fugitive Emissionsi m J
/ i ijr i
ELECTRIC FURNACE
CONTINUOUS CASTING
BILLET AND SLAB UNIT
I Surface runnoff |
j water l"
Discharges from iron and steel industry (sheet \ of 2).
-------
I Particulates, Fume
Grinding
Scarfing
(Tl
PRIM/
BREAKDOWN
MILL
'HOT STRIP
MILL
DIRECT SHIPMENTS OF
INGOTS, SLABS,
BILLETS AND BLOOMl
HEAVY STRUCTURALS
MILL
BAR AND ROD
NAIL AND WIRE
PRODUCTS MILL
Solids
Oil
Grease
SEAMLESla PIPE
AND TUBE
COLD FINISHING
BAR MILL
WELDED PIPE
WELDED PIPE
MILL
GALVANIZED
PRODUCTS
Contact Cooling
Water
Precleaning and
Rinse Waters
Solids
Acids
Oils
PLATE MILL
TIN
PLATING
TIN PLATE AND OTHER
COATED PRODUCTS
Discharges from iron and steel industry (sheet 2 of 2).
-------
quantities of pollutants to the atmosphere. The demonstration was
aimed at reducing (or eliminating) the smoke emissions.
In the EPA/AISI system (shown below), oven emissions during charg-
ing are controlled by an ascension pipe steam ejector, which can force
the gases (evolved during charging) through the ascension pipe into
the gas-collecting main. Free passage of the gas across the oven during
charging is controlled by a pusher machine leveler bar. Oven ports are
sealed (by mating with the drop sleeves on the hopper) during charging
to prevent air from being drawn into the oven and to prevent signifi-
cant emissions if the oven pressure rises.
A detailed emission-testing program was conducted to define the
control capabilities of the EPA/AISI coke oven charging demonstration.
The program included an analysis of particulate emissions to determine
amounts of all hazardous compounds that would be expected from coal
charging. A primary objective of the program was to develop a standard
analytical technique for measuring emissions evolved from coke oven
charging: simultaneously, such easily used methods as optical techniques
were checked against more rigorous analytical methods.
ASCENSION
PIPE AND ELBOW
FEED HOPPER
WITH SHUTOFF
VALVE
GAS COLLECTION MAIN
LEVELING BAR
PUSHER MACHINE
EPA/AISI coke charging system.
177
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As a result of the progress to date on this installation, several
coke producers are installing charging systems utilizing the basic
concepts of the EPA/AISI smokeless coke charging system.
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 incandescent coke from the
sealed coking oven through a guide into an open, shallow-bed car for trans-
port to a batch-type quenching station. Substantial emissions of smoke
and particulate are discharged into the atmosphere throughout this opera-
tion. This situation is aggravated if the push contains incompletely
carbonized coke. At the quench station, large quantities of water are
poured into the bed of hot coke. The instantaneous formation of steam re-
sults in the discharge of large quantities of entrained particulates to
the atmosphere.
In the EPA/National Steel system (shown below), the coke is complet-
ely enclosed from the moment it leaves the oven until after it is
quenched. . Emissions 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. Emissions evolved from the hot coke in the
underground track hoppers are also controlled 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 be-
cause 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 contin-
uous cokemaking processes may not be available until the end of that
period, most new batteries will be conventional slot ovens with useful
178
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COKE
HANDLING
EMERGENCY
COKE QUENCH
SYSTEM AND
WHARF
COKE
GUIDE
GAS HOOD
CLEANING \ DOOR
CAR v \ MACHINE
HOT COKE
TRANSFER
CAR
TRACK HOPPER
FUME EXHAUST
AND GAS
CLEANING SYSTEM
SPRAY WATER
. AND STEAM
EXHAUST SYSTEM
TRACK HOPPER
FUME EXHAUST
AND GAS
CLEANING SYSTEM
COKE
HANDLING
EMERGENCY
COKE DUMP
PIT
TRACK
RECEIVING
HOPPERS
EPA/National Steel coke pushing and quenching system.
lives extending well into the next century. Demonstration of this
system will provide proven emission control technology which can be
integrated into the initial plant design.
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)
Startup, originally targeted for December 1972, was delayed 6
months due to an explosion to the battery basement. Startup 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 difficult to obviate.
Presently the entire system, including instrumentation, is ready
179
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for testing. 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 essentially complete. The battery is
down now due to low steel demands. Testing will begin as soon as the
battery is up to production, probably early in 1976. Ambient air
measurements are being taken to develop data on background pollution
levels prior to restart of battery.
The Phase 2 effort will consist of long-term emission testing and
a system evaluation program to establish the system's emission control
potential; system operability, reliability, and maintainability, and
the system's operating cost. This will be 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 partic-
ulate at various locations around the coke plant.
0 Extensive measurements of water quality to identify water pol-
lutants in the effluents, as well as the potential air pol-
lutants 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-1976.
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 scrubber, and a modified quench
car with a synchronization system for coordinating the quench car's move-
ment 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
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CO
DOORS
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WATER RECIRCULATING
PUMPS RECIRCULATING
WATER TANK
Koppers/Ford coke oven smoke emission abatement system.
-------
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 complete control system can be installed.
The test and evaluation portion of the study includes 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 will be developed
as well as data on utility and labor requirements, system reliability,
and control effectiveness. The final report is anticipated early in
1976. The design manual was published in September 1974.
Guidelines for Coke Oven Pollution Control Applicability. To en-
courage industry application of EPA-demonstrated coke oven air pollu-
tion control technology, there is a strong need for a set of guidelines
showning 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 demonstra-
tions were designed and operated to coexist with existing features and
operating techniques of the host battery. 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
technique called "staged charging," first disclosed in 1961 by M. R.
Heades 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 some physical alterations to the charging com-
ponents but is mainly dependent on the precise manual execution of
specific procedures for good pollution control. On the other hand,
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the EPA/AISI Smokeless Coke Oven Charging System, also a sequential charg-
ing technique but of a different type, has the demonstrated potential
advantage of a fully automated system in achieving repeatability of opera-
tion. A system which adapts the automated methods of the EPA/AISI system
to the requirements of staged charging would be expected to perform, on a
repeatable basis, better than either of the two basic approaches. Therefore,
even though staged charging v/as not demonstrated by EPA, its apparent
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
control technology and U.S. coke batteries and show how the control
technology can be meshed with the batteries in the most technically
feasible and economical way.
Accordingly, a 15-month project has been designed to develop guide-
lines for application of demonstrated coke battery air pollution control
technology to existing and new coke batteries. Specific control tech-
nologies to be examined are the EPA/AISI Smokeless Coke Oven Charging
System, the Enclosed Coke Pushing and Quenching System, the Smokeless
Coke Pushing System, and staged charging (industrial development). The
guidelines will examine characteristics of the control system that are
important in design, construction, and operation and relate these
characteristics to application of the control systems to U.S. coke
batteries based upon examination of their characteristics and requirements.
The final report will be used by coke producers in planning the applica-
tion of the control technology and by regulatory officials in specifying
air pollution control strategies and enforcement actions. A contract
for this project is expected by early 1976.
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 and may be used in the
development of emission standards. Emission tests were planned to be
183
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completed in October 1975; however, because of a plant slow-down the
test was postponed until November. It now appears that the plant which
was to be tested is being shut down completely; therefore, a new test-
ing site is being sought.
The sampling method being used was developed under contract with
BatteHe-Columbus Laboratories. The system for capturing emissions
worked well except that the hood and door temperatures rose sufficiently
high to cause excessive door leakage, making the test nonrepresenta-
tive. Since then, detailed thermal analyses have been performed on the
coke oven door and sampling apparatus; modifications to the hood have
solved the temperature problem. Samples to be taken will include:
coke and coal, gaseous, particulate, and condensible organic samples.
Analyses to be performed include: GC-MS, Spark Source MS, High Resolu-
tion MS, and toxicology studies. This study is expected to be completed
by February 1976.
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, completely 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, co-funded on a 50-50 basis 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 designed to define the causes of the leakage,
identify the operating conditions which must be tolerated by the seal-
ing material, investigate other work being done in this area, and con-
ceptualize 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
concept is of the metal-to-metal type; the alternative concept is of
the compressible- elastomer type.
The procurement plan for Phase II is currently being prepared.
This phase will develop, fabricate, and test selected sealing concepts.
This will be accomplished in eight tasks, including:
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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.
Phase II is expected to begin early in 1976.
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 semienclosed
area around the blast furnace base containing the furnace tapping equip-
ment and molten pig iron (hot metal) and slag distribution systems.
The hot metal, the principal emission source, is saturated with carbon
as its exits from the furnace. Rejection 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. Additionally, particles of
iron oxide, are formed and carried av/ay simultaneously.
In September 1975, a contract was awarded to Betz Environmental
Engineers for preliminary 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 will be analyzed in detail to establish the emission
control potential, capital and operating costs, impact on current
operating practices, potential risks involved, and follow-on develop-
ment needs.
Sinter Plant Windbox Emission Control
Sinter, in the iron and steel industry, is an iron-bearing material
suitable for charging into a blast furnace. The sintering process com-
bines natural ores of fine particle size and iron-bearing wastes re-
covered from various other steelmaking processes (e.g., flue dust, mill
scale, and settling basin solids) with coke breeze and limestone. Lime-
stone is added to provide the required flux for the iron-bearing material
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when processed in the blast furnace; the coke breeze is used for igni-
tion 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 through the long, moving sinter bed. This exit stream contains
particles and gases of varying chemical composition. First generation
air pollution abatement equipment in the form of cyclone separators is
incapable of achieving desired levels of pollutant control. These
cyclones remove the larger particles thus prolonging fan life; but the
fine particles, hydrocarbons, and gaseous pollutants are not removed.
Wide experience in the United States indicates that electrostatic
precipitators 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 contaminants including hydro-
carbons 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 (shown below) recycles gas,
after preliminary cleaning and prior to final cleaning, back to the
sinter bed. Field testing information and engineering evaluations indi-
cate that this recycling reduces both the emissions of unoxidized hydro-
carbon particulates and the final gas volume being discharged. Although
the emission reduction may be substantial, it is anticipated that a
low-energy air pollution control system must be used along with recycl-
ing to remove remaining contaminants, primarily particulates.
A project was initiated in mid-1973 covering two phases. Phase I
consisted of an historical review and a detailed engineering design.
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RECYCLE HOOD
00
STACK IGNITION FURNACE
RECYCLE GAS
CONTROL HOUSE
WASTE GAS
CONTROL HOUSE
Weirton Steel Division sinter plant gas recirculation system.
-------
This was completed in 1975: the final report included a theoretical
analysis of recycle application 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 emission testing and system evaluation program. Also
to be tested is a large-scale gravel bed filter on the sinter plant
exhaust without recycle.
The recycle system was installed (at company expense) and placed
into operation in July 1975, one month ahead of schedule. The opti-
mization program is now underway. Tests to date have shown that re-
cycle as high as 40.7 percent can be achieved without adverse effects
on sinter quality or machine operation. Optimization will continue
with evaluation of the recycle with variations in the sinter mix.
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 steelmaking process in the U.S. iron and steel industry.
The basic operations involved in producing steel by the BOP proc-
ess are charging scrap, charging hot metal, oxygen blow, chemical tests,
and tapping.
Presently, there is no technology for effectively capturing the
emissions during charging. The emissions evolved during charging of
the BOP furnace include extremely fine particles of iron oxide, hydro-
carbons present on the cold metal portion of the charge, graphite par-
ticles, 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.
JERL-RTP's approach to solving this problem was first to con-
struct the 1-ton capacity pilot vessel (shown below) facility to be
used as the vehicle for evaluating a wide range of methods to control
the charging emissions.
Accordingly, a contract was signed in mid-1973 with the National
Steel Corporation: to review past efforts to control BOP charging
188
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Basic oxygen process 1-ton capacity pilot vessel.
189
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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 con-
trolling the particulates, gases, and fumes emitted during charging of
BOP steel making vessels. This development program concentrated on process
modifications that will allow the emissions to be collected. Considera-
tion was also given to suppression of the emissions within the vessel.
Specifications and conceptual designs will be developed for prototype
emission collection systems. Additional specifications will be developed
for a gas cleaning system to be added to the prototype collection sys-
tem. The development program is structured so that the results will be
applicable to the total industry. The final report is expected early
in 1976.
Iron Foundry Processes
The cupola (see iron foundry process emission sources, below) is
the device most often used to melt gray iron. However, in recent years,
two events have caused significant difficulties in the cupola's use:
first, enactment of air pollution regulations restricting cupolas'
voluminous, gaseous and particulate emissions; and second, substantially
increased fuel prices. These problems, added to the cupola's energy
wastefulness, represent the major difficulties involved in a successful
and economical cupola operation. However, technology does exist to
substantially alleviate all three problems.
lERL-RTP's first effort to solve these problems was aimed at
demonstrating the use of a dry, solid-media heat exchanger for the pro-
duction of hot blast air for the cupola as an integral component of
the air pollution control system. Environmental and economic advan-
tages were expected in the form of reductions in emissions, fuel costs,
operating costs, and air pollution control equipment costs. Data on
the operation of the cupola and heat exchanger were to be analyzed with
and used to refine a computer model. The refined model was then to be
used to extend the results to other related operations. This effort
was terminated when it became apparent that the system could not be
made operational because of problems in interfacing the operation of
the cupola, heat exchanger, and air pollution control equipment. The
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METAUICS
FINISHING
COOLING AND
CLEANING
Iron foundry process emission sources.
-------
final report describing this effort is due in January 1976.
lERL-RTP's second effort involved program redirection 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
development. The analysis of each system utilized actual operating
data whenever possible to determine capital and operating costs, emis-
sion control capability, energy savings, and operating and maintenance
procedures and requirements.
This second effort shows that many foundries can achieve substan-
tial 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 recuper-
ator 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 is due in February 1976.
Characterization and Control of Ferroalloy Furnace Emissions
The ferroalloy industry's principal source of emissions is the sub-
merged arc electric furnace. (See ferroalloy production process diagram,
following.) In this furnace, ferroalloys are usually smelted by reducing
the ore with carbon, producing both the desired metallics and substantial
quantities of CO (in some cases, more CO is produced than metallics).
Gases evolved from ferroalloy furnaces entrain large quantities of particu-
lates which, because of the high temperatures involved in the reaction
zone, are primarily in the submicron size range. Domestic ferroalloy fur-
nace 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 mix-
ture is then collected and treated with conventional particulate control
equipment before being vented to the atmosphere.
Some furnaces in Europe and Japan are hooded tightly so that no excess
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RAW MATERIALS HANDLING, PREPARATION AND CHARGING'
MELTING AND CASTING'
FUGITIVE EMISSIONS^-
FUMES
I! ihl II
PARTICULATES
JT
SOLIDS
us
co
CRUSHING WEIGH-FEEDING
PRODUCT SIZING AND HANDLING-
I
I
SURFACE WATER
RUN-OFF
Ferroalloy production process.
-------
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 par-
ti cul ate emitted is decreased by approximately the same factor of 20 to
200. Additionally 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 en-
closed furnaces (diagrammed below), feeling that they may reduce the
ability to change from one ferroalloy product to another. (The standard
of performance reflects this industry position.) lERL-RTP's efforts have
been directed toward the solution of this problem. Specific objectives of
lERL-RTP's work within the past year have been:
0 To compare the flexibility of open and totally enclosed ferro-
alloy furnaces and ascertain the true significance of the
flexibility problem.
0 To identify current practices which can be used to minimize
any flexibility problem which may arise in totally enclosed
furnaces.
0 To develop recommendations for an additional program to be
undertaken by EPA, and to develop or demonstrate techniques
or systems to minimize the problem.
Under contract to IERL-RTP, Battelle-Columbus Laboratories pro-
duced a report, "A Study of Ferroalloy Product Flexibility," that ad-
dresses these areas. 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 fur-
nace 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.
194
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INDUCED
AIR
FEED-
TAP
HOLE
ELECTRODES
"Q
GAS OFFTAKE
FURNACE
INDUCED
AIR
Open-hooded ferroalloy furnace.
ELECTRODES
FIXED
SEALS
MIX
FEED
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TAP *
HOLE \
\
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URN
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ACE
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/
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Enclosed ferroalloy furnace with fixed seals.
195
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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 Labora-
tories identified extremely high concentrations 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 needed to confirm these preliminary results.
Plans to test a totally enclosed silicomanganese and ferromanganese
furnace near Quebec, Canada, had been made. Because of an extended labor
strike and malfunctioning of the furnace scrubber system, it became neces-
sary to select an alternate site. Attempts are being made to identify an
alternate outside the United States.
Depending on the outcome of the tests and how thoroughly the POM's
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.
Fugitive Emissions
During the past 3 years it has become increasingly obvious that sig-
nificant amounts of particulate and gaseous emissions are being emitted
to the atmosphere from sources other than the stacks in a number of indus-
trial operations. An investigation performed by The Research Corporation
(TRC) for EPA indicates that several metallurgical processes are included
in those industries which most characteristically demonstrate a high degree
of fugitive emissions. Several additional EPA investigations have
similarly suggested the need for fugitive emission research and the devel-
opment of control techniques for metallurgical processes. One of these
investigations was performed to determine the probable cause of unusually
high concentrations of S02 detected by ambient air monitors at a specific
copper and lead primary smelter. This investigation, concurring with
196
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plant officials, concluded that the most probable cause of these high
S02 concentrations was fugitive emissions. Another EPA investigation
was performed to determine the cause of high ambient air concentrations of
arsenic and lead in areas surrounding a specific copper smelter. It was
likewise concluded here that the detected high concentration could not be
attributed to stack effluent but more probably to fugitive emissions.
Officials in the copper industry have strongly indicated that fugitive
emissions should not be neglected in the study of emissions from smelters
since they account for 5 to 8 percent of the S02 emitted.
The processes being considered in this study are all pyrometallurgical:
primary copper and lead smelters, integrated iron and steel plants, and
iron foundries. This study does not include mining or preliminary concen-
tration processes. Emissions from pushing, quenching, charging, and door
leakage of coke ovens also will not be included since current ongoing EPA
efforts are being directed to these sources; however, other potential
fugitive emissions sources associated with coke oven batteries, e.g., sizing,
screening, and storage of coke and coal will be included.
Although each of the subject processes is unique in many ways, a
number of similarities exist to which simultaneous analysis may be econom-
ically applied. Each of these processes has several raw material streams
typically consisting of a reductant and energy source (usually coke), metal-
bearing material (ore, scrap), and flux for removing impurities from the
metal. Each of these materials is stockpiled and often undergoes several
transfer steps before being charged to the reactor vessel. These stockpiling
and material-hand!ing operations are all potential fugitive emission sources.
Another potentially serious source of fugitive emissions in the subject in-
dustries is the reactor vessel itself. Gases, fumes, and particulates often
escape from the vessel during charging and discharging of batch or semicon-
tinuous operations and also from incomplete sealing of the vessel during
operation.
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 or systems for the control of fugitive emissions from a number of
metallurgical processes. The purposes of Phase I are: (1) to characterize
197
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fugitive emission sources in integrated iron and steel plants, primary
copper and lead smelters, and iron foundries; (2) to prioritize these
emissions; (3) to determine the environmental impact of these emissions;
and (4) to make recommendations 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 identified emissions.
CONTROL OF EFFLUENT DISCHARGES
In the manufacture of roughly 132 million tons of steel, about 4.4
trillion gallons of water are diverted through the industry's mills, an
average of about 36,700 gallons per ton of steel shipped. Most of this
water becomes heavily contaminated with solids, acids, heat, and various
other pollutants, some of which (like phenols, cadmium, and cyanide) are
considered to be hazardous or toxic.
Major sources of contaminated process water are coking, sintering,
blast furnace operation, steelmaking, continuous casting, scale removal
(pickling), cold rolling, and coating operations.
Coking produces from 19 to 40 gallons of highly contaminated water
for each ton of coke produced. The most critical constituents of the
wastewaters are ammonia, phenols, and cyanide. Ammonia is normally re-
moved by distillation followed by absorption in either sulfuric acid
(for sale as ammonium sulfate) or phosphoric acid (from which it is
stripped to be sold as anhydrous ammonia while the acid is reused). The
most economically practical proven system for control of phenol and
cyanide is biological oxidation. Breakpoint chlorination, ozonation,
and/or activated filtration have been found useful as final polishing
techniques but are unsuitable for treatment of raw wastes.
In sintering, the older dry dust collection technology for control
of pollutants in process gases has been replaced by wet gas cleaning methods
to achieve greater air pollution control. The wet scrubber effluents then
pose a water contamination problem. The solution would appear to lie in
198
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the development of nonwater-using methods of gas cleaning, or the develop-
ment of a closed-cycle treatment method.
In blast furnace operations, effluents from the wet scrubbers include
suspended solids, phenols, and cyanides. The scrubber water is customarily
treated and recycled, but the percentage of blowdown in nearly all in-
stances is higher than desirable.
For the steelmaking process also, the primary source of waterborne
waste is the use of wet fume collectors for air pollution control. By
use of nonwater-using air pollution control technology or by the applica-
tion of waste treatment methods with complete recycle, a steelmaking shop
could be operated with no aqueous discharge.
The continuous casting process, in addition to noncontact cooling
water, uses considerable quantities of contact cooling water. This water
becomes contaminated primarily with small particles of iron oxide (sus-
pended solids) and also picks up some small amount of oil and grease from
lubricants used on the equipment. The contact cooling water is an integral
part of this new process, and methods for materially reducing either the
volume or the level of contamination are not now available.
Waste pickle liquor (HPL) from pickling of steel contains unreacted
acid plus the ferrous salts of whatever acid or acids were used. There are
two separate problems: batch dumps of concentrated pickle liquor, and
rinse waters containing the same contaminants but in much greater volume
and much more dilute. Concentrated dumps of waste hydrochloric acid
pickle liquor can be thermally regenerated to yield high-purity acid for
recycle and a ferric oxide coproduct; a number of processes are now com-
merically available. Concentrated sulfuric acid WPL can be chilled or
evaporated to crystallize out the ferrous sulfate, and the remaining
unreacted acid can then be made up to full strength with fresh acid and
reused. There is still the major problem of what to do with the ferrous
sulfate, for which there is no market, and which is unsuitable for landfill
without further processing. The best technology available provides for
neutralization of the sulfuric acid with lime. This yields an effluent
satisfactory for discharge at most locations, but also yields quantities
of iron hydroxide/calcium sulfate sludge.
199
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For mixed acids, efforts have been made to develop advanced technology,
such as electromembrane regeneration of sulfuric acid EPL and ion exchange
treatment, but neutralization is the only technology to date with real-
world applicability. For rinse waters, too, neutralization is the best
available technology, with ion exchange and reverse osmosis showing
promise.
In cold reduction mills, a water/oil emulsion is sprayed directly on
the material and rolls as the material enters the rolls, generating heat
and oil as pollutants. While newer plants use a recycle system, there is
still the very serious problem of what to do with batch dumps of spent
emulsion. For large-scale operations, present established technology
calls for chemical emulsion breaking followed by dissolved air flotation.
Disadvantages of this process are: (1) it is costly for small-scale opera-
tions; (2) it greatly increases the dissolved solids level of the efflu-
ent; (3) the resulting oily sludge is heavily contaminated with dissolved
solids and usually has an undesirably high water content; and (4) the
process requires a lot of space.
Current studies are underway for the development and demonstration
of ultrafi.ltration as a means of concentrating oil emulsions, and of an
electrolytic separation process. Either or both of these processes promise
to provide the means of overcoming the primary disadvantages of the chemical
emulsion-breaking process.
In coating operations, concentrated plating baths and rinse waters are
effluent discharge problems. In general, suitable treatment methods have
been developed by the job-shop electroplating industry. What is still
needed is to adapt that technology to the larger and steadier volume and to
the much more constant composition encountered in this segment of the
industry.
To solve problems of discharges from ferrous metallurgical processes,
efforts are primarily directed to three ongoing projects: (1) treatment
of coke plant waste liquor; (2) demonstration and evaluation of counter-
current rinsing for reducing pollution from a halogen tinplating line; and
(3) regeneration of hydrochloric acid waste pickle liquor.
200
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U.S./USSR TASK FORCE ON ABATEMENT OF AIR POLLUTION FROM THE IRON
AND STEEL INDUSTRY
To provide for a cross-fertilization of technology on the control of
air pollution from the iron and steel industry, an extensive program
(under the auspices of the U.S./USSR Environmental Agreement of 1972) has
been underway between the U.S. and the USSR for the exchange of informa-
tion.
In March 1975, an agreement was undertaken with Battelle Memorial
Institute for technical and managerial work necessary for the successful
implementation of the U.S./USSR Task Force protocols. The contract pro-
vides for preparation of materials for transmittal as Protocol Reports
to the USSR; the review, analysis, and publication of Protocol Reports
received from the USSR; preparation for visits to the U.S. of USSR dele-
gates; and preparation for visits of U.S. delegates to the USSR.
Five protocol reports are in various stages of publication.
Non-ferrous Metallurgical Processes
Late in 1975, as a result of an EPA Office of Research and Develop-
ment reorganization, lERL-RTP's non-ferrous smelting program was transferred
to lERL-Cincinnati. The following description of the program is applicable
to the time of its transfer.
lERL-RTP's Non-ferrous Smelter Research and Development Program was
part of a total EPA research effort to ensure development of technology
required to control air pollution and to develop a complete data base of
emissions and control technology so that the Clean Air Act requirements
can be implemented for this industry. To meet this effort, projects under-
way in 1975 were concentrated in the four main areas of control of lean S02
streams, control of fugitive emissions, the evaluation of new metal-
winning processes, and the development of an emission and control data
base.
CONTROL OF LEAN S02 STREAMS
One of the most serious problems currently facing the U.S. smelting
industry (one preventing attainment of Ambient Air Quality Standards) is
the emission of large amounts of S02 in dilute gas streams. When S02
concentrations are above approximately 4 percent, it is feasible to pro-
duce sulfuric acid utilizing this strong S02 stream. However, at S02
201
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concentrations below 4 percent autothermal catalytic conversion cannot be
maintained. Therefore, alternate methods are being considered for lean
S02 streams.
Two alternatives exist for controlling lean S02 streams: application
of flue gas cleaning technology to existing streams, and modification of
existing lean streams to increase S02 content to enable control with a
sulfuric acid plant. The application of these approaches to specific
smelters must also be evaluated, due to significant differences of the
various smelters.
Application of Flue Gas Desulfurization Technology
One approach to control lean S02 streams in smelters is to make use
of SO control technology that has already been demonstrated in steam/
A
electric utility applications. The demonstration of feasibility would
be most concerned with showing that the process would operate on lean
smelter streams, which in actuality do not differ greatly from the flue
gas streams on which the processes currently operate.
An engineering feasibility study was completed in 1975, which:
0 Determined the range of S02 concentrations with which control
processes could operate.
0 Determined the particulate control capabilities of the S02
control processes.
0 Matched the control capabilities with specific smelter
emission reduction needs.
Processes evaluated included Well man-Lord, Limestone Scrubbing, Mag-Ox
Scrubbing, Citrate Process, Sulfuric Acid Plant, Double-Alkali Scrubbing,
DMA Xylidine, and Ammonium Scrubbing.
Application of Gas Stream Blending Technology
A possible technique for controlling lean smelter S02 streams in
copper smelters is to blend the lean stream with other, stronger S02 gases
so that the combined stream will still be able to be autothermally con-
verted to sulfuric acid. This technique came to lERL-RTP's attention as
a consequence of the PL-480 work in Yugoslavia.
In 1975, IERL-RTP contracted for a study of gas stream blending to
demonstrate (by a series of logical technical steps) how anticipated
202
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blending problems can be solved and the contained SO can be converted
y\
to sulfuric acid. The project focuses upon these technological problems
and limitations that may be inherent in the gas streams from concentrate
roasters, reverberatory furnaces, and converters as they relate to the
application of the vanadium-oxide catalyzed sulfuric acid process. It
will investigate the factors that affect the compatability of the acid plant
with the smelter gas streams and examine the possibility of modifying these
factors. The results will be applied in appraising the technical and economic
feasibility of using gas blending at those U.S. smelters to which it should
apply. This requires analysis of both the smelter gases as feed to the
acid plant, and the sulfuric acid plant itself, since both the feed gases
and the acid plant are expected to require adaptations. Additionally,
this technique was studied in conjunction with EPA's OAQPS as the basis
for lifting the exemption in the Standard of Performance for those smelters
whose concentrates contain large quantities of impurities.
Application to Specific Smelters
There are sufficient differences among smelters to require that once
feasibility is demonstrated, applicability must then be demonstrated on
a smelter-by-smelter basis. To this end, EPA has developed design infor-
mation for each U.S. copper smelter. Design parameters such as plant
layout, space availability, and gas analysis will be determined in
sufficient detail to permit engineering design of lean stream control
techniques for specific smelters.
Based on this analysis of individual smelters, the study of flue gas
desulfurization technology, and the study of gas stream blending, a summary
effort will be undertaken to prepare preliminary designs based on the best
matches between control scheme and smelter configuration and technology.
In most cases, alternate control schemes will be analyzed. With this in-
formation, decisions concerning the reasonableness of smelter lean S02
streams can be made by others.
CONTROL OF FUGITIVE EMISSIONS
Fugitive emissions (i.e., those that do not emanate from a well-
defined source) present possibly the most difficult control problem in
non-ferrous smelting. There is little available information concerning
203
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the types of pollutants, the amounts, their effects, or their controls.
Because of the similarity of fugitive emission problems in a number
of metallurgical industries, the problem has been approached from a pro-
gram aimed at several metallurgical industries. The first phase of the
program has: (1) identified fugitive emission sources within integrated
iron and steel plants, primary copper and lead smelters, and iron foundries;
(2) prioritized these emissions based on environmental impact; and (3) made
recommendations for future research, development, and/or demonstration
projects to aid in the reduction of fugitive emissions from those sources
determined to be most critical. Material balances developed across the
smelter and the individual unit operations, in the Yugoslavian PL-480
non-ferrous smelting projects, are expected to help define the magnitude
and process site for these fugitive emissions.
ENVIRONMENTAL EVALUATION OF NEW METAL-WINNING PROCESSES
Increasing emphasis is being placed on processes other than the
standard roaster, reverberatory furnace converter system for winning non-
ferrous metals from their ores and concentrates. These processes, which
use advanced pyrometallurgical and hydrometallurgical techniques, either
have recently been placed into use commercially, or are being readied for
it. As these processes are brought to commercial operation, especially
for incremental expansion and replacement of some retired current capacity,
they may cause new air pollution problems of which awareness should be
developed.
To this end, EPA entered into an Interagency Agreement with the
Bureau of Mines' Salt Lake City Metallurgy Research Center to investigate
the environmental and energy considerations of emerging non-ferrous copper
winning processes. Processes such as electric furnace smelting, Noranda
flash smelting, Hecla-El Paso roasting-hydrometallurgical, Arbiter, Sherritt-
Gordon-Cominco, Cymet, Duval "CLEAR," Mitsubishi, oxygen-enriched reverbera-
tory furnace, converter smelting, and top blown rotary converter (TBRC)
processes are being examined.
DEVELOPMENT OF EMISSION AND CONTROL DATA BASE
To enable EPA to deal effectively with the environmental problems
associated with non-ferrous smelters, there is a broad program to develop
204
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a complete data base of emissions and control technology. This informa-
tion is used to support ongoing EPA activities such as New Source Per-
formance Standard development, enforcement activities, and control tech-
nology research and development. Equally important, this data base will
ensure that the EPA assessment of existing problems is accurate and that
EPA will be in a position to address future potential smelter environ-
mental problems as more is learned in such related areas as health effects.
Two separate efforts have been 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 the two 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 SO control equipment on emission of other pollutants, particularly
A
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 SO , NO , CO, C02, and other gaseous pollutants and for
A A
particulate mass and size distribution. The final reports are being
readied for publication in early 1976.
Emission Characterization and Control--Transient Operation
A major concern of air pollution regulatory agencies is regulation
and control of high emission levels from stationary sources during trans-
ient operations: process startups, shutdowns, upsets, or changes. Such
control is particularly important in industries where New Source Perform-
ance Standards have been set: industrial plants must submit quarterly
reports notifying EPA when standards are violated because of an operation-
al upset.
IERL-RTP has initiated a program to characterize various process
emissions and to measure the performance of the "best" current emissions
control equipment during transient operations. Data developed will en-
able regulatory agencies to decide if specific industries should be
205
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allowed to deviate from air pollution standards during the periods of
unsteady-state process operations. The studies also identify any addition-
al requirements for R&D effort to improve emission control during these
operations.
In August 1975 a report was published giving results of a review
of information currently available on the effects of transient operating
conditions on air emissions from fossil-fuel-fired steam-electric gener-
ating plants. Information was obtained from scientific literature,
personal visits to utility companies, and correspondence with utility
companies and manufacturers of generating plant equipment. Emissions
of concern were NO , SO , particulates, and visible emissions. Particular
A X
attention was given to older coal-fired generators, used to provide the
cycling portion of the diurnal variation in electricity generated by
electric utilities. No consideration was given to flue gas desulfuriza-
tion processes used to remove SO . Transient conditions included in
/\
this study were startups, shutdowns, cycling, and upset conditions
caused by equipment malfunctions or changes in fuel characteristics
or load.
A second study in the utility area involved a 4-month continuous
monitoring study of emissions from a Magnesium Oxide (Mag-Ox) Scrubbing
System. In addition to determining steady-state emissions, the tests were
designed to monitor both operating parameters and emissions during start-
up, shutdown, and malfunctions to determine system characteristics during
these abnormal conditions. An engineering report will be completed in
February 1976, evaluating test results and outlining methods to reduce
emissions during malfunctions.
A final report on a study of sulfuric acid plant emissions during
startup, shutdown, and malfunctions will be published in January 1976.
The report will give results of a study of dual-absorption contact sul-
furic acid plants, as well as single-absorption plants equipped with vent
gas cleaning systems for removal of S02, to determine the relationship
between process parameters and air emissions. Processes studied were
dual-absorption acid plants and single-absorption acid plants equipped
with sodium scrubbers, ammonia scrubbers, and molecular sieve adsorbers.
206
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Emissions considered were S02 and acid mist emissions and vent gas
opacity. Relationships were developed for normal operations and compared
to off-normal operations such as shutdown, startup, malfunction, and
misoperation.
A followup study on sulfuric acid plants, to be published in February
1976, will examine maintenance procedures of critical equipment in both
single- and double-contact acid plants with the aim of reducing the number
of emission-causing malfunctions in the plants. Good maintenance practice
will be outlined and critical maintenance procedures will be suggested.
This program will continue with the responsibility for gathering
information on transient operation for specific sources and industries
relegated to IERL-RTP divisions and branches having delegated responsibility
for those sources and industries.
PROCESS MEASUREMENTS
lERL-RTP's activities relating to process measurements involve both
the development of sampling and analysis strategies, and staff reviews
of sampling and analysis portions of field test programs. In fulfillment
of these activities, lERL-RTP's work is categorized in three major areas:
sample acquisition, sample analysis, and acquisition of process stream
parameters (e.g., flow, temperature, pressure). The Laboratory's major
activities in these areas include the development of particulate sizing
techniques, the promulgation of gas volumetric flow measurement and gas
sample extraction methodologies, and the issuance of documentation
defining an environmental assessment sampling and analysis strategy.
To support all IERL-RTP program areas, the Laboratory's process
measurements efforts have been concentrated on the areas of control equip-
ment evaluation and environmental assessment.
Control Equipment Evaluation
One of two major areas of IERL-RTP process measurements activities,
control equipment evaluation, consists of two work areas—particle mea-
surement and chemical analysis and sampling.
PARTICLE MEASUREMENT
The development of particle sizing techniques continued to receive
considerable attention during 1975. Based on data from studies conducted
207
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by Southern Research in 1974, guidelines for the field use of inertial
impactors were presented at a conference of IERL-RTP contractors. These
guidelines have been published.
Programs were initiated in 1975 for the examination of new techniques
for the measurement of ultrafine particulate matter, and efforts were con-
tinued in the development and evaluation of in situ and real time particu-
late sizing instrumentation.
The prototype model of an automatic particle sizing device, developed
under contract by GCA, was completed and tested. Efforts were also made
to improve the reliability of the IERL-RTP developed droplet sizing and
counting device for the evaluation of demister efficiency. Other sizing
devices studied during 1975 included: a Pills IV laser light scattering
unit (Environmental Systems), a piezoelectric cascade impactor (Celesco),
a Brink impactor, and a series cyclone, all pictured below.
CHEMICAL ANALYSIS AND SAMPLING
Techniques for the sampling and analysis of trace inorganic materials
in gas, liquid, slurry, and solids process streams were tested during 1975
under an IERL-RTP contract with TRW. Particular attention was paid to
materials in their elemental and anion forms; e.g., As, Ba, Mg, Pb, N03~,
and P04~3. In addition, a manual was published, setting forth recommended
sampling and analytical procedures.
Another IERL-RTP contract with TRW concerned the recommendation of
sampling and analytical procedures for coal gasification plants. During
1975, a manual was published under this contract, reviewing techniques and
outlining procedures designed to have broad applicability in this field.
Extensive work was also done to develop methods for the collection
and analysis of organic materials in industrial gas streams. Particular
attention was paid to a technique, developed by Battelle, involving the
use of chromatographic support material. This technique is being evaluated
under both field and laboratory conditions.
In the area of development of new and better sampling techniques, an
important study of volumetric flow measurements was conducted by TRW for
IERL-RTP. Results of this study have been issued.
208
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x
IX)
1 >
Piezoelectric impactor. Pills IV laser light scattering unit.
Particle sizing instruments evaluated in (ERL-RTP's aerodynamic test facility study.
-------
Environmental Assessment Testing Strategies
lERL-RTP's Process Measurements Branch has extensively examined two
field test options for the performance of an environmental assessment. The
analytical goals of both options were identical: identification of specific
inorganic and organic compounds, cytotoxicity testing, mutagenicity test-
ing, and carcinogenicity testing. Both options would acquire samples of
each process feed stock stream, product stream, and waste stream in suf-
ficient quantity to complete the rigorous chemical and biological test
matrix. The basic differences between the two options are the mechanism
used to achieve the goals, and the resultant cost effectiveness of each.
The first option is a direct approach. It involves the planning
and execution of a single comprehensive sampling and analysis effort. The
direct approach is philosophically attractive and has been examined on
the basis of cost-to-implement at a constant level of information output.
The second option is a phased approach. It requires two separate,
distinct levels of sampling and analysis. Level 1 sampling and analysis
has goals of gross identification of the pollution potential of a source
and the setting of sampling and analysis priorities for level 2. Level 2
sampling and analysis has a goal of the refined accurate identification
of specific pollutants in specific streams from a given source.
Assuming a constant level of information output, TRW and Mitre esti-
mated the performance costs associated with the environmental assessment
of a limestone wet scrubber and a coal gasifier. Cost comparisons, using
both options, are tabulated below.
Option Limestone Wet Scrubbing Coal Gasifier
Phased approach--
Level 1 $ 24,380 $ 139,425
Level 2 294,550 1,179.510
Total $318,930 $1,318,935
Direct approach-- $424,300 $3,077,500
Based on the above analysis, the phased sampling and analysis option was
selected as the most cost effective for performing an environmental assess-
ment. This option required the development of novel sampling equipment
and the formulation of an analysis procedure.
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A high-volume, series cyclone sampling system was developed for IERL-
RTP under contract by McCrone and Southern Research. The design was fab-
ricated and field-tested at 10 industrial sites by TRW. The sampling sys-
tem operated during the field tests without a major failure. A new version,
shown in simplified form below, has been designed. Construction of the
prototype was initiated in 1975. The complete system, designated the
Source Assessment Sampling System (SASS), will be available commercially
by early 1976.
The analysis procedure which has been developed to support lERL-RTP's
environmental assessment program includes chemical analysis, physical
morphology, and bioassay. The level 1 samples which will be acquired will
be subjected to elemental analysis by spark source spectroscopy, to organic
class identification by both liquid chromatography and infrared spectros-
copy, and to bioassay. Each of these analytical systems has been tested
on both field-acquired and synthetic samples. To date, no deficiencies
have been identified in the analytical system. An interim report, "Evalua-
tion of Selected Methods To Assess the Potential Hazards Associated With
Industrial Particulate Emissions," has been issued. A final report will
be issued in 1976. Analysis options applicable to level 2 samples will
be issued as a series of technical manuals. The organic sampling and
analysis technical manuals will be issued early in 1976.
In summary, environmental assessment was lERL-RTP's major new em-
phasis during 1975 in the area of process measurements. Its goal is to
develop a conceptual approach to a coherent sampling and analytical pro-
gram for all types of environmental assessment projects. A special effort
is being made to evaluate all possible techniques, and to concentrate on
those most likely to give usable results.
211
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STACK T.C.
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SAMPLE
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CONTROLLED
COOLED
SECTION
IMP/COOLER
TRACE ELEMENT
COLLECTOR
GAS METERING
SYSTEM
VACOUM
GAGE
VACUUM
PUMP
Source assessment sampling system (SASS).
-------
Appendix A
THE INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY,
RESEARCH TRIANGLE PARK
The Industrial Environmental Research Laboratory, Research Triangle
Park (IERL-RTP) has completed its fifth full year of activity as part
of the U.S. Environmental Protection Agency. Formerly titled the Con-
trol Systems Laboratory, 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 in-
creased 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 Pollution 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 re-
search 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 leadership and support.
In December 1963, Congress passed the Clean Air Act when it was
evident that, although progress was being made toward a better under-
standing of pollution problems, comparable progress was not being made
toward controlling the problems. Basically, the 1963 Clean Air Act:
A-l
-------
(1) Authorizes awarding Federal grants to State and local
agencies to assist in developing, establishing, or im-
proving pollution control programs.
(2) Authorizes Federal action to abate interstate pollution
problems beyond the reach of individual States and cities.
(3) Expands the Federal pollution research and development
program.
(4) Emphasizes investigation of sulfur oxides pollution from
coal and oil combustion.
(5) Requires the development of criteria on effects of air
pollution on health and property.
(6) Emphasizes the role of the Federal Government on control-
ling air pollution 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 pollu-
tion 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:
(1) The entire Nation is covered by 247 Air Quality Regions.
(2) National Air Quality Standards have been established for
all pollutants covered by the air quality criteria docu-
ments .
(3) 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.
(4) EPA is establishing National Emission Standards for
Hazardous Pollutants.
(5) 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.
A-2
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(6) Emission limits have been established for designated
pollutants from motor vehicles, and a time frame for
achieving these standards has been defined.
(7) 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 improved methods (with industrywide application) for the prevention
and control of air pollution resulting from the combustion of fuels by:
0 Conducting and accelerating research programs directed toward
developing improved low-cost techniques for—
1. Control of fuel combustion byproducts.
2. Removal of potential air pollutants from fuels prior to
combustion.
3. Control of emissions from fuel evaporation.
4. Improving the efficiency of fuel combustion so as to de-
crease air pollution.
5. Producing synthetic or new fuels which, when used, result
in decreased air pollution.
0 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
commercially valuable byproducts resulting from the removal of
pollutants.
On July 9, 1970, the President sent Reorganization Plan Wo. 3 of
1970 to the Senate and the House of Representatives. This Plan, estab-
lishing EPA, combined certain of the pollution-control-related functions
of six Federal agencies:
A-3
-------
0 The Atomic Energy Conmission.
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 Program Operations Office functions
as a program monitoring and evaluating group. The other three groups,
all programrnatically (rather than functionally) oriented Divisions, are
engaged in work ranging from small-scale experimental work and explora-
tory 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 operations with multimedia environmental impacts associated with
the extraction, processing, conversion, and utilization of energy and
mineral resources and with industrial processing and manufacturing. The
Laboratory also supports the identification and evaluation of environ-
mental control alternatives of those operations as well as the assess-
ment of associated environmental and socioeconomic impacts. lERL-RTP's
program, consisting of in-house 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
inputs (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
A-4
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ADMINISTRATOR
EPA
ASSISTANT ADMINISTRATOR
RESEARCH AND DEVELOPMENT
I
PIRECTOR
OFFICE OF ENERGY,
MINERALS, AND INDUSTRY
1
UTILITIES AND
INDUSTRIAL POWER
DIVISION
Mi
MB
MM
PROCESS
TECHNOLOGY
(REGENERABLE)
BRANCH
EMISSIONS/EFFLU-
ENT TECHNOLOGY
(NON-REGENERABLE)
BRANCH
PARTICULATE
TECHNOLOGY
BRANCH
DIRECTOR
DEPUTY DIRECTOR
INDUSTRIAL ENVIRONMENTAL
RESEARCH LABORATORY, RTP
1
1 1
ENERGY ASSESS-
MENT AND CON-
TROL DIVISION
mm
mm
mm
COMBUSTION
RESEARCH
BRANCH
ADVANCED
PROCESSES
BRANCH
FUEL
PROCESSES
BRANCH
INDUSTRIAL
PROCESSES
DIVISION
CHEMICAL
PROCESSES
BRANCH
METALLURGICAL
PROCESSES
BRANCH
PROCESS
MEASUREMENTS
BRANCH
.
PROGRAM
OPERATIONS
OFFICE
SPECIAL
STUDIES
STAFF
PLANNING,
MANAGEMENT, AND
ADMINISTRATION
STAFF
TECHNICAL
INFORMATION
SERVICE
Figure A-1. Organization of the Industrial Environmental Research Laboratory,
Research Triangle Park.
-------
MANDATED
R&D RESPONSIBILITIES
INDUSTRY AND
POLLUTANT
IDENTIFICATION
I
R&D NEEDS FROM REGIONS,
ERC'S, OAWP, AND EPA
ADMINISTRATOR'S DIRECTIVES
INDUSTRY STUDY
t
PRESENT AMBIENT
CONCENTRATION
BY AQCR
SOURCE EMISSION
DATA
CURRENTLY AVAILABLE
CONTROL TECHNIQUES
CONTROL REQUIREMENTS
NAAQS, NSPS,
NESHAPS
I
CONTROL STRATEGY (REGIONAL AND NATIONAL)
I
CONCENTRATION OR EMISSION LEVEL WITH
BEST AVAILABLE TECHNOLOGY
(ECONOMICS INCLUDED)
JL
ADDITIONAL CONTROL REQUIRED
1
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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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 pollut-
ants. The list of pollutants (by priority) leads to industry studies
which determine the sources and amounts of pollutants emitted and iden-
tify the currently available control technology.
With the Ambient Air Quality Standards fixed, regions are identi-
fied 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 Standards to be met. If additional new
technology is required, IERL-RTP can mount an RD&D program to provide
this technology, in cooperation with the private sector.
A-7
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Appendix B
METRIC CONVERSION FACTORS
Although EPA's policy is to use metric units for quantitative de-
scriptions, 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.
Yields metric
2
kg(wt)/cm
liters
cal
°C
cm
liters
9
cm
kg
kg
Nonmetric
atm
bbl
Btu
°F
ft
ft3
gr
in.
Ib
ton (short)
Multiplied
1.03
158.99
252
5/9 (F -
30.48
28.32
0.06
2.54
0.45
907.18
by
32)
B-l
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