U.S. Environmental Protection Agency
Office of Research and Development
Industrial Environmental Research
Laboratory
Cincinnati. Ohio 45268
EPA-600/7-76-034a
December 1976
ENVIRONMENTAL
CONSIDERATIONS OF
SELECTED ENERGY
CONSERVING MANUFACTURING
PROCESS OPTIONS:
Vol. I Industry Summary
Report
Interagency
Energy-Environment
Research and Development
Program Report
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S.
Environmental Protection Agency, have been grouped into seven series.
These seven broad categories were established to facilitate further
development and application of environmental technology. Elimination
of traditional grouping was consciously planned to foster technology
transfer and a maximum interface in related fields. The seven series
are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
A. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from
the effort funded under the 17-agency Federal Energy/Environment
Research and Development Program. These studies relate to EPA's
mission to protect the public health and welfare from adverse effects
of pollutants associated with energy systems. The goal of the Program
is to assure the rapid development of domestic energy supplies in an
environmentallycompatible manner by providing the necessary
environmental data and control technology. Investigations include
analyses of the transport of energy-related pollutants and their health
and ecological effects; assessments of, and development of, control
technologies for energy systems; and integrated assessments of a wide
range of energy-related environmental issues.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
-------
EPA-600/7-76-034a
December 1976
ENVIRONMENTAL CONSIDERATIONS OF SELECTED
ENERGY CONSERVING MANUFACTURING PROCESS OPTIONS
Volume I
INDUSTRY SUMMARY REPORT
EPA Contract No. 68-03-2198
Project Officer
Herbert S. Skovronek
Industrial Pollution Control Division
Industrial Environmental Research Laboratory - Cincinnati
Edison, New Jersey 08817
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental.Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.
11
-------
FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL-Ci) assists in developing and demonstrating new and im-
proved methodologies that will meet these needs both efficiently and
economically.
This study, consisting of 15 reports, identifies promising industrial
processes and practices in 13 energy-intensive industries which, if imple-
mented over the coming 10 to 15 years, could result in more effective uti-
lization of energy resources. The study was carried out to assess the po-
tential environmental/energy impacts of such changes and the adequacy of
existing control technology in order to identify potential conflicts with
environmental regulations and to alert the Agency to areas where its activi-
ties and policies could influence the future choice of alternatives. The
results will be used by the EPA's Office of Research and Development to de-
fine those areas where existing pollution control technology suffices, where
current and anticipated programs adequately address the areas identified by
the contractor, and where selected program reorientation seems necessary.
Specific data will also be of considerable value to individual researchers
as industry background and in decision-making concerning project selection
and direction. The Power Technology and Conservation Branch of the Energy
Systems-Environmental Control Division should be contacted for additional
information on the program.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
-------
EXECUTIVE SUMMARY
This project has examined 13 energy-intensive industrial manufacturing
segments from the standpoint of identifying environmental impact of energy-
conserving changes in processes or practices with high probability of being
implemented during the next 10 to 15 years. Changes possible without major
process modification, such as improved housekeeping and thermal efficiencies,
were not considered. Within the context of the project, conservation was
considered achievable by two possible routes: direct thermal savings and
also savings in the domestically more scarce energy forms by switching direct-
fired fuels and feedstocks from natural gas and light petroleum streams to
heavier petroleum fractions- and coal.
Within each industry segment, several of the more probable processes
were selected for detailed analysis and were compared to a conventional
technology base case. Over 80 conventional and new process alternatives
were evaluated.
Although actual process changes are expected to occur slowly on the
average, specific changes at specific sites could occur at any time, includ-
ing the immediate future, and could require EPA regulatory attention. The
most serious environmental problems will result from switching to direct-
fired fuels and feedstocks containing higher concentrations of sulfur and
other components that will lead to greater quantities of SOX, NQX, particu-
lates, toxic materials, and sludges. Options that would lead to both energy
savings (Btu's) and environmental benefits were also identified. Examples
of these options are given in Table ES-1. The need for more cost effective
pollution control, for better instrumentation, and for health effect studies
were stressed.
First and second-level priorities for research, development, and
demonstration can be placed on areas in each industry examined as has been
done in Table ES-2. In the context of this study, the industries of greatest
need of environmental technology RD&D are iron and steel, petroleum refining,
aluminum, and pulp and paper. Of the remaining industries included in the
table, all require additional environmental RD&D, except for chloralkali and
fertilizer mixing, which are judged to be industries for which adequate
control technology is available.
Generic technologies which cross several industries were also identified
where RD&D efforts should be placed. These areas of generic technology
consist of: preheating of feedstocks, sulfur removal from hot gases, fluid-
ized bed technology, heat recovery, NOX emission control, use of oxygen
rather than air for more efficient process combustion or reaction, application
of electric furnaces, and use of solvent-based rather than aqueous-based
processes.
iv
-------
TABLE ES-1
EXAMPLES OF ENERGY-CONSERVING (FEWER BTU'S) PROCESS TECHNOLOGY
HAVING POTENTIALLY SMALLER POLLUTION CONTROL COSTS
Aluminum (Volume VIII*)
- Alcoa chloride
Cement (Volume X)
- Suspension preheater/flash calciner
Chloralkali (Volume XII)
- Dimensionally stable anodes with microporous or ion exchange membranes
Copper (>90% sulfur recovery) (Volume XIV)
- Noranda smelting process
- Flash smelting
Glass (Volume XI)
- Preheating/batch agglomeration
Iron and Steel (Volume III)
- Collection of CO gases from Basic Oxygen Process
- External desulfurization of blast furnace pig iron
Phosphoric Acid (detergent grade) (Volume XIII)
- Cleanup of wet acid by neutralization/precipitation
Phosphoric Acid via Strong Acid Process (Volume XIII)
Pulp and Paper (Volume V)
- Rapson effluent free process
- Alkaline-oxygen process
Textiles (Volume IX)
- Advanced aqueous processing
*Volume numbers refer to individual reports from the project.
v
-------
TABLE ES-2
AREAS FOR RESEARCH AND DEVELOPMENT IN POLLUTION CONTROL
Fine part iculate removal technology- This
would Include especially those participates
resulting from metallic smokes and sublimed
substances such as Mercury, arsenic, zinc, etc.
Collection or control of fugitive emissions
trom process equipment
Better definition of the environmental and
biological impacts of the following emissions
with respect to obtaining more quantitative
knowledge for establishing emission regulations,
a. Gases such as SOX, NOX, CO, F, Cl, NKj
b. Mecallie smokes
c. Organic compounds that have high smog
characteristics or carcinogenic aspects
Odor Control
Improved instrumentation for rapid monitoring
and recording of airborne emissions
Better definition of the environr>entai and
biological impact of substances which cannot
be removed by best available technology
economically achievable. This will include,
principally, metals and organic compounds
that have long biological half-lines or
carcinogenic effects.
Suspended solids removed from treated
waatewaters
Removal of refractory organic compounds not
achievable by technologies now designated as
BATEA by EPA
Color removal
Removal of dissolved metals
Improved instrumentation for rapid monitoring
and recovery of waterborne pollutants
Solid Wastes
Demonstration of adequate landfill Disposal
techniques
Demonstration of thermal destruction
technologies
Research into the methods of categorization,
regulation and legal methodologies for
controlling rhe disposal of solid wastes
(1) Denotes First Level Priority
(2) Denotes Second Level Priority
( "
I
1
1
1
I
I
1
1
]
I
1
1
2
]
f
I
2
1
2
1
I
2
1
1
2
2
1
1
1
/*<:
i
2
1
'1
1
1
1
j
1
1
2
2
2
/ O ฃ
2
2
2
1
2
2
2
1
1
/ ^
1
1
1
1
1
1
2
2
1
f
1
1
1
1
1
1
1
2
2
1
1
1
1
I
1
1
1
1
2
2
2
/ฐc:
i
2
1
1
2
2
1
1
/ซe
i
i
i
i
2
2
1
/ ^
1
2
2
2
2
2
/
1
2
1
1
1
2
1
1
/ w
1
1
1
1
1
I
2
2
2
1
f
1
1
1
vi
-------
TABLE OF CONTENTS
FOREWORD ill
EXECUTIVE SUMMARY iv
LIST OF TABLES ix
ACKNOWLEDGMENTS x
CONVERSION TABLE xii
I. INTRODUCTION 1
II. SCOPE 4
III. APPROACH 10
IV. FINDINGS 13
A. POLLUTION CONTROL 13
1. Overview 13
2. Pollution Control of Industrial Processes 14
B. NEW PROCESS TECHNOLOGY 19
1. Alumina and Aluminum 20
2. Ammonia 22
3. Cement 22
4. Chlor-alkali 26
5. Copper 27
6. Fertilizers 29
7. Glass 30
8. Iron and Steel 31
9. Olefins 35
10. Petroleum Refinery 36
11. Phosphorus 38
12. Pulp and Paper 41
13. Textiles 44
C. IDENTIFICATION OF CROSS INDUSTRY TECHNOLOGY 46
1. Preheating 47
2. Sulfur Removal from Hot Cases 47
vii
-------
TABLE OF CONTENTS (Cont.)
3. Fluidized Beds 48
4. Heat Recovery 49
5. NOX Emissions 49
6. Use of Oxygen 49
7. Electric Furnaces 49
8. Use of Solvent 50
V. PROCESS RESEARCH AREAS 51
1. Aluminum 51
2. Ammonia 51
3. Cement 51
4. Chlor-alkali 52
5. Copper 52
6. Fertilizers 53
7. Glass 54
8. Iron and Steel 54
9. Olefins 55
10. Petroleum Refining 55
11. Phosphorus 56
12. Pulp and Paper 56
13. Textiles 57
VI. FUTURE REASSESSMENT OF PROCESS OPTIONS 59
viii
-------
LIST OF TABLES
Number Page
1 Distribution of Energy Consumption by Sector (1971) 2
2 Distribution of Energy Consumption Within the Manufacturing
Sector (1971) 2
3 Summary of 1971 Energy Purchased in Selected Industry Sectors 6
4 Processes Selected for Detailed Analysis 7
5 Benchmark Energy Costs for Coal, Oil, Gas, and Electric
Power (March 1975) 11
ix
-------
ACKNOWLEDGMENTS
This study could not have been accomplished without the support of a
great number of people in government agencies, industry, trade associations
and universities. Although it would be impossible to mention each individual
by name, we would like to take this opportunity to acknowledge the particular
support of a few such people.
Dr. Herbert S. Skovronek, Project Officer, was a valuable resource to us
throughout the study. He not only supplied us with information on work
presently being done in other branches of EPA and other government agencies,
but served as an indefatigable guide and critic as the study progressed. His
advisors within EPA, FEA, DOC, and NBS also provided us with insights and
perspectives valuable for the shaping of the study.
During the course of the study we also had occasion to contact many
individuals within industry and trade associations. Where appropriate we
have made reference to these contacts within the various reports. Frequently,
however, because of the study's emphasis on future developments with compara-
tive assessments of new technology, information given to us was of a confiden-
tial nature or was supplied to us with the understanding that it was not to be
credited. Therefore, we extend a general thanks to all those whose comments
were valuable to us for their interest in and contribution to this study.
Finally, because of the broad range of industries covered in this study,
we are indebted to many people within Arthur D. Little, Inc. for their parti-
cipation. Responsible for the guidance and completion of the overall study were
Mr. Henry E. Haley, Project Manager; Dr. Charles L. Kusik, Technical Director;
Mr. James I. Stevens, Environmental Coordinator; and Ms. Anne B. Littlefield,
Administrative Coordinator.
Members of the environmental team were Dr. Indrakumar L. Jashnani,
Mr. Edmund H. Dohnert and Dr. Richard Stephens (consultant).
Within the individual industry studies we would like to acknowledge the
contributions of the following people.
Iron and Steel; Dr. Michel R. Mounier, Principal Investigator
Dr. Krishna Parameswaran
Petroleum Refining; Mr. R. Peter Stickles, Principal Investigator
Mr. Edward Interess
Mr. Stephen A. Reber
Dr. James Kittrell (consultant)
Dr. Leigh Short (consultant)
-------
Pulp and Paper:
Oleftns:
Ammonia:
Aluminum:
Textiles:
Cement:
Glass:
Chlor-Alkali:
Phosphorus/
Phosphoric Acid;
Primary Copper;
Fertilizers:
Mr. Fred D. lannazzi, Principal Investigator
Mr. Donald B. Sparrow
Mr. Edward Myskowski (consultant)
Mr. Karl P. Pagans
Mr. G. E. Wong
Mr. Stanley E. Dale, Principal Investigator
Mr. R. Peter Stickles
Mr. J. Kevin O'Neill
Mr. George B. Hegeman
Mr. John L. Sherff, Principal Investigator
Ms. Nancy J. Cunningham
Mr. Harry W. Lambe
Mr. Richard W. Hyde, Principal Investigator
Ms. Anne B. Littlefield
Dr. Charles L. Kusik
Mr, Edward L. Pepper
Mr. Edwin L. Field
Mr, John W. Rafferty
Dr. Douglas Shooter, Principal Investigator
Mr, Robert M. Green (consultant)
Mr, Edward S, Shanley
Dr, John Willard (consultant)
Dr, Richard F. Heitmiller
Dr, Paul A. Huska, Principal Investigator
Ms. Anne B. Littlefield
Mr, J, Kevin O'Neill
Dr. D. William Lee, Principal Investigator
Mr, Michael Rossetti
Mr, R. Peter Stickles
Mr, Edward Interess
Dr, Ravindra M. Nadkarni
Mr. Roger E. Shamel, Principal Investigator
Mr, Harry W. Lambe
Mr, Richard P. Schneider
Mr. William V. Keary, Principal Investigator
Mr. Harry W. Lambe
Mr, George C, Sweeney
Dr, Krishna Parameswaran
Dr. Ravindra M. Nadkarni, Principal Investigator
Dr, Michel R. Mounier
Dr. Krishna Parameswaran
Mr. John L. Sherff, Principal Investigator
Mr. Roger Shamel
Dr. Indrakumar L. Jashnani
xi
-------
ENGLISH-METRIC (SI) CONVERSION FACTORS
To Convert From
Acre
Atmosphere (normal)
Barrel (42 gal)
British Thermal Unit
Centipoise
Degree Fahrenheit
Degree Rankine
Foot
Foot /minute
Foot3
Foot2
Foot/sec
2
Foot /hr
Gallon (U.S. liquid)
Horsepower (550 ft-1
Horsepower (electric)
Horsepower (metric)
Inch
Kilowatt-hour
Litre
Micron
Mil
Mile (U.S. statute)
Poise
Pound force (avdp)
Pound mass (avdp)
Ton (assay)
Ton (long)
Ton (metric)
Ton (short)
Tonne
To
Metre2
i Pascal
Metre3
.t Joule
Pascal-second
Degree Celsius
Degree Kelvin
Metre
0
Metre /sec
Metre3
Metre2
Metre/sec
2
Metre /sec
1) Metre3
Ibf/sec) Watt
.c) Watt
Watt
Metre
Joule
Metre3
Metre
Metre
Metre
Pascal-second
Newton
Kilogram
Kilogram
Kilogram
Kilogram
Kilogram
Kilogram
Multiply By
4,046
101,325
0.1589
1,055
0.001
t^'- (tJ-32)/1.8
^ o _ ^^/l fi
0.3048
0.0004719
0.02831
0.09290
0.3048
0.00002580
0.003785
745.7
746.0
735.5
0.02540
3.60 x 106
1.000 x 10~3
1.000 x 10~6
0.00002540
1,609
0.1000
4.448
0.4536
0.02916
1,016
1,000
907.1
1,000
Source: American National Standards Institute, "Standard Metric Practice
Guide," March 15, 1973. (ANS72101-1973) (ASTM Designation E380-72)
-------
I. INTRODUCTION
In many industrial sectors significant reductions in energy usage can
be achieved by better maintenance and housekeeping (e.g., shutting off standby
furnaces, automatic thermostat control, elimination of steam and heat leaks,
and the like) and greater emphasis on the optimization of energy usage.
Because of shortages or risk of shortages of a specific fuel form, economic
pressures, changes in feedstocks, and the like, further improvements in energy
conservation can be expected from the introduction of new industrial pro-
cesses. Such process alternatives will undoubtedly result in changes in air,
water, and solid waste discharges.
Process changes introduced by the major industrial sectors can indeed
impact energy consumption because industry accounts for about 40% of total
energy use (when electric power use is allocated to the various industry
sectors), as shown in Table 1. The other 60% or so of energy use can be
attributed to the household/commercial segment and the transportation sector.
Table 2 shows that five industry groups accounted for about three-quarters of
the total energy consumption in the manufacturing sector as follows:
The Primary Metals Industry group (SIC 33) accounted for 25% of
total manufacturing energy used.
The Petroleum and Coal Products group (SIC 29) accounted for about
16 to 18%, depending on whether electricity is valued on a thermal
equivalent or fossil fuel basis.
The Chemical and Allied Products group (SIC 28) accounted for about
17-18%.
The Paper and Allied Products group (SIC 26) accounted for about
8%.
The Stone, Clay, and Glass Products group (SIC 32) accounted for
about 8%.
Each of these industry sectors has experienced environmental problems of
one type or another. The nature of these problems can be expected to change
as industry introduces new processes and implements new technology for a
variety of reasons including efforts to reduce energy use or the use of certain
fuel forms.
-------
TABLE I
DISTRIBUTION OF ENERGY CONSUMPTION BY SECTOR (1971)
Sector
Industrial
-Manufacturing
-Non-Manufacturing
Total Industrial
Household/Commercial
Transportation
Electrical Generation
Total
Purchased Fuels
Purchased Fuels Purchased Fuels
Plus Electricity* Plus Electricity
Valued on Thermal Valued on Fossil
Basis Fuel Basis**
1012 Btu
14,329
5.965
20,294
14,281
16,971
17,443
%
20.8
8.6
29.4
20.7
24.6
25.3
1012Btu
16,085
6,538
22,623
17,441
16,989
-
7.
27.9
11.7
39.6
30.6
29.8
-
10l2Btu
19.732
7,728
27.460
24,006
17,026
-
%
28.8
U . 3
40.1
35.0
24.9
-
68,989 100.0
57,053 100.0
68,492T 100.0
Purchased electricity valued at its thermal equivalence of 3,412 Btu/kWh and
allocated to consuming sectors.
Purchased electricity valued at an approximate fossil fuel equivalence
of 10,500 Btu/kWh and allocated to consuming sectors.
Totals would be equivalent if all electric energy were generated from
fossil fuels at a rate of 10,500 Btu/kWh.
Source: FEA, Project Independence, Blueprint, Vol. 3, November 1974, and
Arthur D. Little, Inc. estimates.
TABLE 2
DISTRIBUTION OF ENERGY CONSUMPTION WITHIN THE MANUFACTURING SECTOR (1971)
Five Energy Intensive
Manufacturing Industries
(1) Primary Metals Industry
(2) Chemicals & Coal Products
(3) Petroleum & Coal Products
(4) Paper & Allied Products
(5) Stone, Clay & Class Products
Total of Five
Other Manufacturing
Total Manufacturing
Puchased
Fuels only
1012Btu
3,613
2,443
2,877
1,196
1.291
11,420
2.909
14,329
Purchased Fuels Purchased Fuels
and Electricity and Electricity
Valued on . . Valued on Fossil
Thermal Basil ; Fuel Basis(**)
% 1012Btu Z
25.2
17.0
20.1
8.3
9.0
79.6
20.3
99.9(t)
4,030
2,783
2,956
1,315
1,367
12,451
3.634
16,085
25.1
17.3
18.4
8.2
8.5
77.5
22.6
100. l(t
1012Btu %
4,896
3.489
3,120
1,562
1.525
14.592
5.140
* 19,732
24.8
17.7
15.8
7,9
7,7
73.9
26.0
99.9(tl
(*)
(**)
(t)
Purchased electricity valued at its thermal equivalence of 3,412 Btu/kWh.
Purchased electricity valued at an approximate fossil fuel equivalence of
10,500 Btu/kWh.
Failure to sum to 100% due'to rounding error.
Source: FEA Project Independence Blueprint, Vol. 3, November 1974. Based
largely on purchased fuels except for primary metals industries and
petroleum and coal products where captive consumption of energy from
byproducts is included.
-------
Thus the purpose of this study was to address the environmental/energy
impacts of new technology by:
defining the environmental/energy implications of new process
technology in key industry sectors;
assessing the implementability of such new technology;
alerting the EPA to areas where its activities and policies could
influence the choice of process alternatives;
identifying processes demanding additional research and development
in order to
a) provide further information on pollutant loads or environmental
consequences, or
b) provide economically viable pollution control techniques.
The focus of the study was based on examining potential alternative
technology in new facilities. In addition an attempt was made to identify
where such technology could be retrofitted to currently practiced processes.
This report was submitted in partial fulfillment of Contract 68-03-2198
by Arthur D. Little, Inc. under sponsorship of the U.S. Environmental Protec-
tion Agency. This report covers a period from June 9, 1975 to May 14, 1976.
-------
II. SCOPE
During the first month of work under this contract, a priority ranking
of 25 industry sectors was established. It was largely based on judgment of
selected senior ADL staff members; the ranking was then supplemented by readily
available energy consumption data as detailed in the Industry Priority Report
(Vol. II). The scope of this study includes the following 13 industry sectors
which were identified as having the primary opportunities for energy conserva-
tion through new technology or modifications to existing process technology.
Primary Metals Industry (SIC 33)
Blast furnaces and steel mills
Alumina and primary aluminum
- Primary copper
Petroleum and Coal Products (SIC 29)
Petroleum refining
Chemical and Allied Products (SIC 28)
Olefins
- Ammonia
- Fertilizers
Alkalies and chlorine
Phosphorus and phosphoric acid
Paper and Allied Products (SIC 26)
Stone, Clay and Glass Products (SIC 32)
Cement
Glass
Textile Mill Products (SIC 22)
-------
Annual energy consumption for these 13 industry sectors, shown in
Table 3, amounts to about 12 quads,* accounting for about 60 to 65% of the
energy purchased in the manufacturing sector.
Several hundred processes and process options were screened in this
study with over 100 being at least discussed qualitatively in these reports.
Table A shows the 80 processes or process steps which were included for
detailed analyses. Fifty-five of these represent new technological process
options, while the remaining 25 represent "base line or current processes"
against which environmental/energy/cost impacts were gauged.
In selecting changes to be included in this study, criteria were estab-
lished as delineated in the Industry Priority Report. For example, energy
conservation is defined broadly to include conservation of form value of
energy by a process change, e.g., conserving natural gas even while using
more energy units of coal, or a feedstock change. Moreover, energy conserva-
tion resulting from changes in either industrial practice or pollution con-
trol methods is included within the scope, of this study. Emphasis was
placed on process changes with near-term rather than longer term potential
within an approximate span of the next 15 years to 1990. Because of work
funded under other Government contracts** and the desire to focus this study
on process changes, the following were not considered to be within the scope
of this present study:
Improved waste heat utilization;
Energy conservation as a result of better maintenance or "house-
keeping" (e.g., shutting off standby furnaces);
Power generation;
Steam generation by alternative fuels (e.g., use of coal for oil
or gas, carbon monoxide boilers);
Fuel substitution in fired process heaters;
Mining and milling, animal husbandry, agriculture;
Substitution of scrap such as iron, aluminum, or glass, and materials
based on virgin materials, except for the de-inking of waste paper
which has some unusual environmental problems with energy
implications;
*quad = 10 Btu
**A compilation of research in the energy field being conducted by the U.S.
Government, industry, universities, and foreign institutions is contained
in "Energy Conservation Research and Development," Vol. 2.
Nov. 21, 1975, ICF Incorporated, Wash. D.C. This report was sponsored by
EPA under Contract 68-01-3414, BOA 68-01-2472, Task 2.
-------
TABLE 3
SUMMARY OF 1971 ENERGY PURCHASED IN SELECTED INDUSTRY SECTORS
SIC Code
, ,. In Which
Industry Sector 10 Btu/Yr Industry Found
1. Blast furnaces and steel mills 3.49^ 3312
2. Petroleum refining 2.96 ' 2911
3. Paper and allied products 1.59 26
4. Olefins 0.984^ 2818
5. Ammonia 0.63^ 287
6. Aluminum 0.59 3334
7. Textiles 0.54 22
8. Cement 0.52 3241
9. Glass 0.31 3211, 3221, 3229
10. Alkalies and chlorine 0.24 2812
11. Phosphorus and phosphoric ,_.
acid production 0.12ฐ' 2819
12. Primary copper 0.081 3331
13. Fertilizers (excluding ammonia) 0.078 287
Estimate for 1967 reported by FEA Project Independence Blueprint, p. 6-2,
USGPO, November 1974.
(2)
Includes captive consumption of energy from process byproducts (FEA Project
Independence Blueprint)
(3)
Olefins only, includes energy of feedstocks: ADL estimates
(4)
Ammonia feedstock energy included: ADL estimates
'ADL estimates
Source: 1972 Census of Manufactures, FEA Project Independence Blueprint,
USGPO, November 1974, and ADL estimates.
-------
TABLE 4
PROCESSES SELECTED FOR DETAILEb ANALYSIS
Industry Sector
Alumina and
primary aluminum
Armenia
Process Selected
Baseline Process
Product
Nitric acid leaching process
Hydrochloric 'acid leaching process
Toth alumina process
Alcoa chloride electrolysis process
Application of titanium dlboride cathodes
to the existing Hall-Heroult cells
Toth Alumina with Alcoa Chloride process
Ammonia via coil gasification
Ammonia via heavy oil gasification
Bayer
Bayer
Bayer
Hall-Heroult
Hall-Heroult
Bayer with Hall Heroult
Ammonia via natural gas
Ammonia via natural gas
Alumina
Alumina
Alumina
Aluminum
Aluminum
Aluminum
Ammonia
Ammonia
Cement
Chloralkali
Fertilizers
Class
Iron and steel
Olefins
Flash calciner
Fluid-bed cement process
Suspension preheater
Conversion to coal from oil & natural gas'a)
Dlmensionally stable anodes-conventional
Dimensionally stable anodes-expandable
Dinensionally stable anodes-polymer membrane
Dimenslonally stable anodes-ion exchange membrane
Moderii mercury cell
Nitric acid with catalytic reduction for NO
Nitric acid with molecular sieve for HO x
Nitric acid with Grande Paroisse for NO*
Nitric acid with CDL/Vitok for NO x
Nitric acid with Masar for NOX x
Fuel oil firing of fertilizer dryers where emissions
are controlled by bag filters
Coal gasification & glassmaking
Direct coal firing
Electric melting
Coal, hot gas generation & glassmaking
Batch preheating & glassmaking
CO collection from BOP
Direct reduction-electric furnace
External desulfurization of blast furnace hot metal
Dry quenching of coke
Naphtha coil cracking
Gas oil coil cracking
Natural gas or oil fired long kiln
Natural gas or oil fired long kiln
Natural gas or oil fired long kiln
Natural gas or oil fired long kiln
Graphite anode
Graphite anode
Graphite anode
Graphite anode
Graphite anode
diaphragm cell
diaphragm cell
diaphragm cell
diaphragm cell
diaphragm cell
Nitric acid
Nitric acid
Nitric acid
Nitric acid
Nitric acid
Natural gas
with no NOX abatement
with no NOV abatement
with no NO- abatement
f-j red dryers
Natural gas fired furnace with cold charge^)
Natural gas fired furnace with cold charge(b>
Natural gas fired furnace with cold charge^)
Natural gas fired furnace with cold charge^*3'
Natural gas fired furnace with cold charge(b)
Combustion of offgases
Coke oven, blast furnace, BOP
Desulfurization in blast furnace
Wet quenching
Ethane-propane coil cracking
Ethane-propane coil cracking
Portland cement
Portland cement
Portland cement
Portland cement
Chlorine-caustic soda
Chlorine-caustic soda
Chlorine-caustic soda
Chlorine-caustic soda
Chlorine-caustic soda
Nitric acid
Nitric acid
Nitric acid
Nitric.acid
Nitric acid
Mixed fertilizers
Glass (soda-lime)
Glass (soda-lime)
Glass (soda-lime)
Glass (soda-lime)
Glass (soda-lime)
Steel
Steel
Blast furnace hot metal
Quenched coke
Ethylene
Ethylene
-------
TABLE 4
PROCESSES SELECTED FOR DETAILED ANALYSIS (Cont.)
oo
Industry Sector
Paper and
Allied Products
Process Selected
Baseline Process
Product
Alkaline-oxygen pulping
Rapson effluent-free kraft process
Deinking of waste news as a substitute for
mechanical pulping
Thermo-mechanical pulping (IMP)
Petroleum Refining Direct combustion of asphalt in heaters/boilers
Asphalt conversion by hydrocracking (H-OIL)
Asphalt conversion by flexicoking
Internal power generation using asphalt
Hydrogen generation by partial oxidation
Phosphorus
Primary Copper
Textile
Chemical cleanup of wet-process phosphoric acid
Solvent extraction process for wet-process
phosphoric acid
"Strong acid" systems for wet-process phosphoric
acid via "strong acid" process
Outokumpu flash smelting
Noranda process
Mitsubishi process
Oxygen use in flash smelting
Metal recovery from slags by flotation
Arbiter process
Integrated knit fabric mill using advanced aqueous
processing^0)
Integrated knit fabric mill using solvent
processing^0)
Integrated woven fabric mill using advanced aqueous
processing''*)
Conventional kraft
Conventional kraft
Refiner mechanical pulp (RMP)
Refiner mechanical pulp (RMP)
Regional cluster model for 1985 product mix
Regional cluster model for 1985 product mix
Regional cluster model for 1985 product mix
Regional cluster model for 1985 product mix
Regional cluster model for 1985 product mix
Electrothermal phosphoric acid
Electrothermal phosphoric acid
Conventional wet-process phosphoric acid
Reverb./converter
Reverb./converter
Reverb./converter
No oxygen use in flash smelting metal
recovery in electcic furnace
Reverb./converter/electrolytic refining
Knit fabric mill using current aqueous pro-
cessing
Knit fabric mill using current aqueous pro-
cessing
Woven fabric mill using current aqueous pro-
cessing
Slush pulp
Slush pulp
Slush pulp
Slush pulp
Refinery products
Refinery products
Refinery products
Refinery products
Refinery products
Detergent grade phosphoric acid
Detergent grade phosphoric acid
Detergent grade phosphoric acid
Blister copper
Blister copper
Blister copper
Blister copper
Refined copper
Refined copper
Knit fabrics
Knit fabrics
Woven fabrics
(a) Forms part of baseline technology
(b) Side port-regenerative furnace
(c) 100% polyester fiber
(d) 50/50 polyester cotton fiber mix
-------
Production of synthetic fuels and coal (low- and high-Btu gas,
synthetic crude, synthetic fuel oil, etc.)ป
All aspects of industry-related transportation (such as transporta-
tion of raw materials).
While the scope of this study is not meant to be an all-inclusive
assessment of all potential processes within the 13 industry sectors, we
believe it does represent a realistic mix of alternative new processes likely
to be considered in new plants for implementation by industry and, if imple-
mented, having energy/environmental impacts.
-------
III. APPROACH
The methodology used for analysis of the 80 processes identified for
in-depth evaluation within the 13 industry sectors is outlined in the Industry
Priority Report. Important aspects of the methodology include:
Establishing a base line technology against which tne process changes
could be assessed. Normally this base line technology was currently
practiced technology used in a major portion of the industry to
make a given product. In choosing the base line and alternative pro-
cesses, a deliberate attempt was made to start with the same or
similar raw materials and produce the same or similar end-products.
Determining the character and quantity of the pollutants emitted
from the base line and alternative technology. Air, water, and
solid waste were included in this assessment.
Determining the energy requirements and the form of the fuel used
in the base line technology. This included establishing whether oil,
gas, or coal was needed as fossil fuel, for example. The differ-
ent forms of energy were converted to a Btu basis, using common
factors to the extent possible, as discussed in the Priority Report.
Determining the investments and operating costs (both variable and
fixed costs as well as a pretax return on investment) for pollu-
tion control and the basic processing operation.
In choosing base line and alternative technology, no attempt was made to
determine the market acceptability of a product, such as an offcolor paper
that might otherwise meet market requirements. However, when product quality
might become an issue, it was pointed out in our discussion of the alternative
process.
To establish uniformity in the costing methodology, we settled on the
first half of 1975 as the basis for estimating capital investments in operat-
ing costs. Common unit energy costs by geographical region, as shown in
Table 5, were used in this study. Again, where better information on the cost
of various forms of energy was obtained from industry sources, we used the
industry information and so identified it. In addition, labor rates by SIC
classification were used as benchmarks within the industry assessment reports.
Where such labor rates were close to those found in the Bureau of Labor
Statistics information, we normally rounded off the hourly labor rates. In
other cases where a particular industry segment had different labor costs,
as determined from our industry contacts, the industry figures were used and
so identified.
10
-------
TABLE 5
BENCHMARK ENERGY COSTS FOR COAL, OIL, GAS, AND ELECTRIC POWER (MARCH 1975)
State
Arizona - Phoenix
California - Los Angeles
Florida - Tampa
Georgia - Savannah
Illinois - Chicago
Indiana - Indianapolis
Kentucky - Louisville
Louisiana - Baton Rouge
New Mexico - Albuquerque
New York - Buffalo
North Carolina - Greensboro
Ohio - Cincinnati
Oregon - Portland
Pennsylvania - Pittsburgh
South Carolina - Charleston
Tennessee - Memphis
Texas - Houston
Utah - Salt Lake City
'Virginia - Norfolk
Washington - Seattle
West Virginia - Charleston
Wyoming - Cheyenne
Coal
Fuel Prices*
(C/106 Btu;
Oil
69.7
_
97.7
82.4
70.8
58.4
65.7
21.9
119.9
106.3
100.2
-
92.1
119.7
83.6
21.0
50.3
120.3
57.2
82.8
27.7
195.9
241.0
188.7
184.2
154.5
204.4
198.0
172.6
209.7
201.0
217.1
223.9
184.9
214.4
118.2
214.6
186.9
158.6
183.1
-
222.6
Gas
61.4
80.4
71.3
77.3
84.
101.
55.1
58.9
56.
80.
141.6
119.7
105.7
74.5
69.8
55.1
56.0
Estimated
Power Costs
(mil/kWh)
.6
,5
.5
.1
.6
,1
,5
.7
,2
,5
20.
21.
21.
18.8
19.2
16.
12.
14.
16.8
24.8
17.9
17.0
5.7
24.6
16.5
11.9
13.6
16.5
21.3
3.9
17.8
12.5
^Average fuel prices paid by steam-electric plants, statewide.
**
C1974 average statewide industrial power costs multiplied by 1.17 which is
the electric power price index ratio of March 1975 to 1974 average (DOC)
Source: Chemical Week, October 22, 1975.
11
-------
We believe that the benchmark oil prices used in this study, which are
in the nature of $2/10^ Btu, are a reasonable reflection of the cost in
1975 of energy for new facilities. However, the gas and electric power
industries are largely regulated, and we believe that many times the prices
for gas and oil are not an accurate reflection of their value in the market.
If deregulated, we would expect that the price of natural gas would be very
close to that of oil. Making judgments about the future cost of electric
power in 1975 dollars is a bit more difficult, however, because of the inter-
play between fossil fuel-based utility stations (oil, gas, or coal); the cost
of pollution control equipment, if burning a high-sulfur fuel; the advent of
nuclear power; and other reasons. Both investments in power plants, whether
nuclear or thermal, and energy costs have risen dramatically in the past few
years, and thus one can expect substantially higher power costs in the future.
The availability and cost of such power can have an important influence on
the future choice of alternative technologies and should be borne in mind
when examining the cost tables presented for each one of the process options
that we have analyzed. However, the tables will allow readers to make any
corrective changes desired based on their own estimates of future energy
costs.
The Industry Priority Report (Vol. II) describes in further detail the
cost categories and methodology used in allocating investments and fixed costs,
as well as the methodology used in establishing the pollution control tech-
nology, along with investments and operating costs.
12
-------
IV. FINDINGS
Industries using large quantities of energy tend to be mature, enjoying
relatively long plant lives in which rates of equipment renewal are low.
Moreover, these industries are generally capital-intensive and changes are
implemented gradually, resulting in considerable time spans before a signifi-
cant portion of industry capacity is affected by any process changes.
If not in commercial operation abroad, the process changes considered in
these reports have mostly been piloted - at least on .a fairly large scale -
and thus are seriously being considered by industry. Our findings on
environmental/energy impacts of such new technologies are discussed below
under two main topic headings:
Pollution Control, and
New Process Technology.
A. POLLUTION CONTROL
1. Overview
Using current environmental regulations as a guide, an examination of
the new process technologies which might be installed indicates that there is
little likelihood that the nature of the pollution control problems would be
significantly altered from those now facing each of the industries studied.
Clearly, the geographical location, mix of pollutants and volumes of parti-
cular wastes may well change (e.g., CaSO^ generation and disposal from stack
gas scrubbing). In some instances there is clearly a lack of technology to
cope with the removal of fine particulates, such as metallic smokes from
air streams; however, the most frequent reason for industrial resistance to
the installation of pollution control equipment is based either on the costs
or the lack of long-term demonstrated performance capabilities. Although
the pollution control problems of the new processes will undoubtedly be con-
siderably ameliorated by greater attention to the design and operation of the
processes, all of the processes will produce air and water streams which must
be emitted to the environment. Consequently, pollution control technologies
for application at the end-of-the-pipe will still be of importance.
Undoubtedly there will be increased recycle of treated wastewater within
Industrial plants, a situation rarely achievable with gaseous streams, except
perhaps in an installation such as dry quenching of coke. Nevertheless, sys-
tem designs relying on large amounts of recycle are not achieved without
penalties, such as the possible deterioration of product quality, or increased
production of solid wastes, such as sludges, which must be disposed of in an
environmentally acceptable manner. Consequently, research and development
13
-------
efforts on pollution control technologies must be focussed not only on
technology, but also researchers must be continually cognizant of their
effects on the economy, while keeping in perspective the probable cost/
benefits to the ecosystem. As Dr. Peter Lederman* has said (Industrial Water
Engineering - February/March 1976), "The constraints are severe and fly in
the face of the Third Law of Thermodynamics in that we are, during the manu-
facturing, adding entropy to the system which we now wish to remove at mini-
mum energy cost. This is analogous to going uphill while expending no more
energy than to go downhill. While we cannot realistically do this, we need
to accept the challenge to approach it." In accepting this challenge, both
industry and government must critically evaluate not only the technological
objectives of research and development of pollution control systems, but must
also carefully assess the results of these efforts in line with a cost/benefit
analysis. As Dr. Barry Commoner** has pointed out: (1) everything is con-
nected to everything else, and (2) there is no such thing as a "free lunch."
2. Pollution Control of Industrial Processes
Thus, in general, as a result of this study we have found:
There are only a few new processes for which pollution control
energy usage will be significantly different from present processes.
The energy and capital requirements for controlling pollution to
presently established levels usually do not represent a large por-
tion of total production costs. The problem is usually the avail-
ability of capital and the costs incurred in a non-productive
(pollution control) system.
In going from gas to oil to coal, increased environmental impact
in both obtaining the fuel and in using it can be expected.
There is a relatively small amount of statistically significant
data on the amounts of pollutants emitted from present manufactur-
ing processes. At best, estimates of emissions from new processes
can only be qualitative.
Pollution control research and development (R&D) monies from
private sources will always continue to be minimal, because operat-
ing companies rarely see an opportunity for a profit, and equipment
manufacturers have not traditionally expended significant funds for
research and development on pollution control equipment. Thus the
bulk of R&D program support in such areas is dependent on Govern-
ment agencies.
*At the time this report was prepared, Dr. Lederman was on the EPA Head-
quarters staff and was actively advising the Project Officer on this study.
**Dr. Barry Commoner, Closing Circle, published by Knopf, 1971.
U
-------
Research in pollution control technology over the past decade has
resulted in improved efficiency of operation, but no startling
breakthroughs in technology. In the large majority of cases, pol-
lution control technology is known and the major problem is the
demonstration of more efficient operating systems at reduced capital
and operating costs.
Areas in which the EPA might fund research and development efforts within
the 13 industry categories studied in these reports are expected to be largely
in the technologies either for removal of pollutants from air and water
streams, or for preventing the widespread environmental dispersion of concen-
trated pollutants emanating from the process operation. It became apparent
that increased attention must be given to multimedia (air, water, land) effects
and to the total environmental impact, e.g., determining whether the increased
electrical energy used for particulate removal at an industrial plant results
in more emissions (or more tolerable emissions) at the steam-generating plant.
As the effectiveness of pollution control technologies improves, it will become
more difficult to make further improvements technically or economically. Con-
sequently, establishing emission limits which are consonant with the capabili-
ties of the ecosystem to tolerate these emissions will become of increasing
importance. This type of information is needed especially for gaseous pollu-
tants such as (1) SOX, NOX, etc.; (2) organic compounds that may have high
smog-forming characteristics, long biological half-lives, or carcinogenic
potential, and (3) fine particulates, especially metallic smokes. Of course,
the organic compounds mentioned above are of equal interest in water pollution
control where, in addition, the removal of dissolved metals and suspended
solids are other areas of major concern.
In both the air and water pollution control field, there is a need for
improved instrumentation for rapid monitoring and recording of the pollutants
of concern. Increasing problems in the field of solid wastes require not only
demonstration of control technologies, but also establishing the categorization,
and legal methodologies to be utilized in regulating this waste problem. Areas
where research and development efforts should be concentrated and a ranking of
the relative importance within an industry sector are further discussed below.
a. Air Pollution Control Technology
With regard to air emissions in the new technology investigated, we have
identified the following to be deserving of R&D attention:
Improving fine particulate removal technology. This would include
especially those particulates resulting from metallic smokes and
sublimed substances such as mercury, arsenic, zinc, etc. Further
information on the source of pollutants and nature of the problems
in new technology examined in this study is found in the Industry
Assessment Reports dealing with aluminum, ammonia, cement, copper,
fertilizer, glass, iron and steel, petroleum refining, phosphorus,
and pulp and paper.
Collection or control of fugitive emissions from process equipment.
Further information on the source of pollutants and nature of the
15
-------
problems In new technology examined in this study is found in the
Industry Assessment Reports dealing with aluminum, ammonia, copper,
fertilizers, iron and steel, and textiles.
To a lesser extent, it is also a problem in the following industry
sectors: cement, olefins, petroleum refining, phosphorus, and
pulp and paper.
Better definition of the environmental, health, and ecological impacts
of gaseous emissions (such as SOX, NOX, CO, HF, Cl2, NH3> with respect
to obtaining more quantitative knowledge for establishing appropriate
emission regulations. Further information on the source of pollu-
tants and nature of the problems in new technology examined in this
study is found in the Industry Assessment Reports dealing with alu-
minum, ammonia,,cement, chlor-alkali, copper, glass, iron and steel,
petroleum refining, and pulp and paper.
To a lesser extent-, it is also a problem in the olefins industry.
Better definition of the environmental, health, and ecological impacts
of metallic smoke emissions with respect to obtaining more quantita-
tive knowledge for the purpose of establishing appropriate emission
regulations. Further information on the source of pollutants and
nature of the problems in new technology examined in this study is
found in the Industry Assessment Reports dealing with aluminum,
ammonia, cement, copper, glass and iron and steel.
To a lesser extent, it is also a problem in the olefins and petroleum
refining industry sectors.
Better definition of the environmental, ecological, and health impacts
of organic compounds that have a high smog characteristic or poten-
tial carcinogenic properties. More quantitative knowledge is needed
for the purpose of establishing appropriate emission regulations.
Further information on the source of pollutants and nature of the
problems in new technology examined in this study is found in the
Industry Assessment Reports dealing with aluminum, iron and steel,
olefins, petroleum refining, and textiles.
To a lesser extent, it is also a problem in the pulp and paper industry,
Improvements in odor control. Further information on the source of
pollutants and nature of the problems in new technology examined
in this study is found in the Industry Assessment Reports dealing
with petroleum refining and pulp and' paper.
To a lesser extent, it is also a problem in the olefins industry.
Improved instrumentation for rapid monitoring and recording of air-
borne emissions. Further information on the source of pollutants
and nature of the problems in new technology examined in this study
16
-------
is found in the Industry Assessment Reports dealing with aluminum,
copper, glass, iron and steel, and pulp and paper.
To a lesser extent, it is also a problem in the following industry
sectors: cement and petroleum refining.
b. Water Pollution Control Technology
With regard to water pollution control in new technology investigated in
this study, we have identified the following as deserving consideration for
additional research and development.
Better definition of the environmental, health, and ecological impact
of substances which cannot be removed by Best Available Technology
Economically Achievable (BATEA). This will include principally
metals and organic compounds that have long biological half-lives or
carcinogenic effects. Further information on the source of pollu-
tants and nature of the problems in new technology examined in this
study is found in the Industry Assessment Reports dealing with alu-
minum, ammonia, copper, iron and steel, petroleum refining, phosphorus,
and pulp and paper.
Improvements in suspended solids removal from treated wastewaters.
Further information on the source of pollutants and nature of the
problems in new technology examined in this study is found in the
Industry Assessment Reports dealing with ammonia, iron and steel,
petroleum refining, phosphorus, and pulp and paper.
To a lesser extent, it is also a problem in the aluminum, cement,
chlor-alkali, and copper industry sectors.
Removal of refractory organic compounds not achievable by technologies
now designated by EPA as BATEA. Further information on the source
of pollutants and nature of the problems in new technology examined
in this study is found in the Industry Assessment Reports dealing
with iron and steel and textiles.
To a lesser extent, it is also a problem in the aluminum industry.
Improvements in color removal. Further information on the source of
pollutants and nature of the problems in new technology examined in
this study is found in the Industry Assessment Reports dealing with
pulp and paper, and textiles.
To a lesser extent, it is also a problem,in the petroleum refining
industry.
Removal of dissolved metals or inorganic salts. Further information
on the source of pollutants and nature of the problems in new tech-
nology examined in this study is found in the Industry Assessment
Reports dealing with aluminum, iron and steel, and phosphorus.
To a lesser extent, it is also a problem in the chlor-alkali, copper,
glass, and petroleum refining industry sectors.
17
-------
Improved instrumentation for rapid monitoring and recovery of water-
borne pollutants. Further information on the source of pollutants
and nature of the problems in new technology examined in this study
is found in the Industry Assessment Reports dealing with iron and
steel, and pulp and paper.
To a lesser extent, it is also a problem in the ammonia, olefin,
phosphorus, and textile industry sectors.
c. Solid Waste Disposal
With regard to solid wastes emanating from new ^echnology investigated in
this study, the following have been identified as deserving R&D attention.
Demonstration of adequate landfill disposal techniques. Further
information on the source of pollutants and nature of the problems
in new technology examined in this study is found in the Industry
Assessment Reports dealing with aluminum, cement, iron and steel,
petroleum refining, and phosphorus.
To a lesser extent, it is also a problem in the ammonia, chlor-alkali,
copper, glass, olefins, pulp and paper, and textile industry sartors.
Demonstration of thermal destruction technologies. Further informa-
tion on the source of pollutants and nature of the problems In new
technology examined in this study is found in the Industry Assessment
reports dealing with aluminum, olefins, and petroleum.
To a lesser extent, it is also a problem in the chlor-alkali, iron
and steel, and pulp and paper industry sectors.
Additional research into the methods of categorization, regulation
and legal methodologies for controlling the disposal of solid wastes.
Further information on the source of pollutants and nature of the
problems in new technology examined in this study is found in the
Industry Assessment Reports dealing with aluminum, ammonia, cement,
copper, fertilizers, glass, iron and steel, olefins, petroleum
refining, and phosphorus.
To a lesser extent, it is also a problem in the chlor-alkali, pulp
and paper, and textile industry sectors.
Thus, in each case, the direction of research programs should be viewed with
the objective of attaining the maximum effectiveness tor removal or controlling
pollutants at the minimum economic penalty, since it is rarely possible to
remove or control pollutants to present and anticipated standards without entail-
ing cost penalties. Consequently, research programs must be examined within
the framework of cost/benefits to the environment, to health, and to the economy.
18
-------
B. NEW PROCESS TECHNOLOGY
In presenting our findings, we recognize that the quality of the reported
estimates is highly variable; it is influenced by the development stage of the
emerging technology, and hence the amount and type of laboratory data and
operating experience that have been accumulated. The stage of commercializa-
tion is an implicit indication of the quality of the reported data and is
reported in the Industry Assessment Reports (Volumes III-XV), along with the
details of the process evaluation. Thus, conclusions should not be derived
from the findings summarized here without at least a careful reading of the
appropriate Industry Assessment Reports.
Within the processes considered in this study, the major findings are:
Coal is being considered as an alternative fuel or feedstock in many
industries, including ammonia, cement, copper, glass, and iron and
steel (steam coal for metallurgical coal). Thus, pollution problems
associated with the use of coal can be expected to increase.
Pollution control legislation is forcing industry to consider new
process technologies, many of which are energy-conserving. Examples
are found in copper (flash smelting, Mitsubishi, and Noranda proc-
esses) , nitric acid plants (NO abatement using newer technology),
pulp and paper (Rapson process;, and textiles.
Preheating is being considered in many industry sectors. Examples
are found in the glassmaking and cement industries.
Relative energy costs (e.g., cost of natural gas vs. oil vs. coal)
can affect the relative economics of process options rather signifi-
cantly in some industry sectors. Examples can be found in the ammonia
and glassmaking industries.
Changes in raw materials or feedstock availability are causing many
new processes to be examined. Examples are found in alumina (clay
leaching process), ammonia, olefins, and petroleum refining.
High-cost electric power and its availability are prompting the
examination of newer technology. Examples are found in chlor-alkali
production (new cell technology), phosphoric acid (cleanup of wet-
process acid to meet furnace-acid specifications), and aluminum
(Alcoa process).
From a technical viewpoint, energy can be recovered using new process
technology, such as carbon monoxide collection from basic oxygen
furnaces in steelmaking and in the dry quenching of coke. However,
some of these technologies, such as dry quenching, do not appear to
be economically viable in the United States at present day energy costs.
The alternative technologies considered and base line processes are shown
in Table 4, along with products produced. Further details are contained below
with findings in each of the industry sectors presented in alphabetical order.
19
-------
1. Alumina and Aluminum
a. Alumina
(1) Solid Waste
It is clear that more solid waste will be produced from treating clays to
recover alumina by any of the new processesnamely, nitric acid or hydrochloric
acid leaching or the Toth chlorination process than is produced by the exist-
ing Bayer alumina process. This is because bauxite used in the Bayer process
contains about 50% alumina, while clay typically contains only 30-35% alumina
so that there is simply more inert material. However, with the processing
plant near the clay mines, the waste could be returned to mined-out areas,
whereas in the case of a Bayer alumina plant the bauxite is imported and space
must be found to dispose of the solid wastes ("red mud") from the Bayer plants.
(Of course, additional solid waste is generated where bauxite is mined.)
(2) Liquid Waste
In the case of the nitric acid leaching process, the liquid wastes will
contain soluble nitrates, along with other tramp elements, whereas with the
hydrochloric acid and Toth chlorination processes the wastes will contain sol-
uble chlorides. The latter are generally less objectionable than soluble
nitrates. If complete impoundment in an impervious, barrier-lined disposal
area ("zero discharge") were utilized, the pollution control costs would be
greater for any of the clay-based processes than for the presentPSJayer alumina
plants.
(3) Gaseous Emissions
The gaseous emissions from the existing Bayer alumina plants are minor,
limited largely to emissions from the boiler house; these are S02, in amounts
depending on the fuel used, and dust from alumina and lime calcination, all of
which can be controlled to a level meeting existing or anticipated regulations.
In the case of the nitric acid and hydrochloric acid leaching processes,
the tail gases from the decomposition-acid recovery operation could be removed
by caustic scrubbing, but would result in water soluble nitrates and chlorides.
Removal of these dissolved inorganic salts would be costly and, in some removal
systems, energy-intensive. Existing or anticipated effluent limitations for
biologically non-nutritive inorganic salts would not preclude their emission.
However, the nutritive nitrate salts from the nitric acid process will probably
require more extensive control than might be required from the hydrochloric
acid, Toth chlorination, and Bayer alumina processes.
(4) Costs
In the Bayer process, the cost of pollution control at $1.40/ton of alumina
is minor, considering the present value of alumina at $125/ton. The cost for
complete environment control of the new nitric acid and Toth clay-based proc-
esses is estimated to be significantly higher ($4 to $20/ton alumina), which
compares with total estimated production costs of over $200/ton alumina.
20
-------
(5) Energy
Energy consumption for alumina production based on clay is least for the
Toth chlorination, followed by the acid leaching processes. However, all are
higher than the on-site usage for production of alumina from bauxite which
does not include the energy consumption for mining the bauxite or transporta-
tion to the United States.
b. Aluminum
(1) Air Pollution
It seems that the Alcoa process and the use of titanium diboride cathodes
will reduce air pollution problems from the cells and from the anode-making/
baking operations. In the case of the Alcoa chloride process, the anodes will
be inert; this means that anodes would be purchased rather than produced at
the plant, so that air pollution from anode-making in the Alcod process would
be completely eliminated from the aluminum plant. In the case of the use of
titanium diboride cathodes, the fluoride emissions per ton of aluminum pro-
duced would remain the same, but the gas volume to be scrubbed would be lower.
Moreover, we would expect less carbon monoxide emissions per ton of aluminum
produced.
It appears that costs for air pollution control from the cells and cell
rooms of the new Alcoa process and for the use of titanium diboride cathodes
in the Hall process would be less than the costs of producing aluminum in the
existing Hall-Heroult cells. The Alcoa process would be completely closed to
recover chlorine for reuse and, while there might be some losses of chlorine
and/or HC1 to the atmosphere, these would not be as serious as fluoride emissions.
However, the Alcoa process would add a new source of gaseous emissions, namely,
sulfur from the coking step and hydrogen chloride from the chlorinator tail
gas. Of course, both can be removed as required.
(2) Liquid and Solid Waste
The use of titanium diboride would not significantly change the liquid
waste problem from that of the present operations. However, the new Alcoa
process may introduce a new source of liquid and solid waste, which would
consist of sludge and sodium chloride from the cells to bleed off impurities
from the electrolyte.
(3) Costs
The estimated cost of complete environmental control of aluminum plants
is a significant factor in both the capital and operating costs of aluminum
smelters, amounting to 6% of the cost of aluminum from present day plants,
using prebaked electrodes. We are not suggesting reducing standards, but we
believe that the requirements could be reviewed and possibilities for improv-
ing the pollution control systems should be considered. On the other hand,
the new Alcoa process offers a substantial reduction in pollution control
costs, largely because of the elimination of the use of fluoride compounds.
Total production costs are estimated to be 5% lower for the Alcoa chloride
process.
421
-------
(4) Energy
Total energy consumption for production of aluminum via use of titanium
diboride or the Alcoa chloride process can be expected to be 10-20% less tha.
in conventional Hall-Heroult cells.
2. Ammonia
a. Ammonia from Coal
The problems associated with coal gasification are usually gaseous sulfur,
non-methane hydrocarbons formed in the gasifier, wastewater, ash and slag. In
making ammonia from gasified coal, the sulfur must be removed for process
reasons and, once removed, it requires a relatively minor addition of a sulfur-
recovery plant to handle the environmental factors.
The methane and any traces of higher hydrocarbons, which do not take part
in the synthesis, are removed from the ammonia loop in a purge stream which is
used as supplemental fuel.
The wastewater volume is less in making ammonia feedstock than in other
coal gasification processes, because the water is recycled to the reactor to
provide steam. The components of the ash and slag are similar to those pro-
duced in normal industrial coal-fired boilers.
There will be few problems for commercial ammonia plants based on coal
feedstock in meeting the anticipated environmental standards. Difficulties
will be no greater than those encountered in electric power generation, or in
industrial coal-fired boilers and attributable to coal.
In certain geographical areas, use of strip-mined coal is attractive for
this process alternative, since it provides a lower cost feedstock and a poten-
tial place in which to dispose of the large quantities of ash and slag. State
and EPA regulatory policy in developing groundrules related to strip mining
can affect costs and influence the trend of the ammonia industry in choosing
feedstock and slag-disposal methods.
b. Ammonia from Heavy Fuel Oil Alternative
As in the coal alternative, the significant potential environmental prob-
lem is associated with sulfur. The sulfur must be removed for process reasons
and is controlled by the addition of a sulfur recovery plant. The process
wastewater is treatable in conventional biological treatment plants. Therefore,
there will be no unique problems for commercial ammonia plants based on oil
feedstock in meeting the anticipated environmental standards.
3. Cement
Our findings indicate that the quantities and compositions of the various
effluent and process streams associated with the alternative processes con-
sidered in this study are essentially the same as those associated with the
22
-------
conventional long rotary kiln. In all cases, a hydrocarbon fuel is burned with
air to generate the heat required for the cement clinker production. The com-
bustion gases carry dust and volatilized elements from the reactor (i.e., rotary
kiln or fluidized bed). The percent excess air, chemical composition, and
particle distribution of the particulates will change, but it appears that
there are no new species of pollutants and no new effluent streams created.
Nitrogen oxide concentrations may well be lower with the flash calciner and
fluid bed process. In addition, the fluid bed process claims to have a smaller
amount of particulate emissions with higher amount of potentially valuable
alkali sulfates in the collected particulates.
The changes in both cement industry practice and process technology which
we have studied will not result in any potential conflict with anticipated
environmental regulation. For all alternative processes examined, energy use
for pollution control is under 0.1 x 10^ Btu/ton cement with process energy
requirements being about 3 to 6 x 10$ Btu/ton cement. Costs of environmental
control are about $1.90 ฑ$.50 for all alternatives, or about 4% of calculated
operating costs in a new plant. Significant environmental aspects of the indus-
try practice and process changes studied are summarized below.
a. Suspension Preheater
The suspension preheater-equipped rotary kiln is a well-developed, estab-
lished cement clinker production step outside the United States. Although it
gained rapid acceptance in the United States in the 1950's, this clinkering
alternative fell into total disfavor with the U.S. cement industry due to
operating and cement quality problems. However, the present high fuel costs,
combined with continued and apparently successful development and operation
of the suspension preheater outside the United States, has led to its recent
reexamination. Because of extensive experience with actual commercial-scale
operations in a large number of plants throughout the world, the environmental
aspects of the suspension preheater-equipped rotary cement kiln are quite well
known.
Suspension preheater-equipped cement plants are dry process plants, and
therefore have no process water discharge. Typically, suspension preheater-
equipped plants operate with a total dust return to the clinkering step, and
therefore have no waste kiln dust-disposal problem. Occasionally, to meet
alkali specification in the finished cement, preheater kilns are operated with
a bypass of some of the kiln exit gases. The dust collected from this bypass
is discarded, since it is high in alkali content and thereby provides an alkali
purge stream from the process. The quantities of particulates and 862 from a
suspension preheater kiln are well known and present no problems in either
magnitude or nature different from those with which the cement industry is
presently familiar.
If waste kiln dust from a suspension preheater bypass system is discarded,
its physico-chemical characteristics are similar to kiln dusts from cement
plants operating in the United States today. Therefore, the rainwater run-off
and leaching problems associated with the disposal of waste kiln dust from
such a system should also be no different from those associated with the dis-
posal of kiln dust from plants operating today.
2.3
-------
b. Flash Calciner
This is a significant new variation of the suspension preheater rotary kiln
which has gained wide acceptance in Japan and Europe. The first commercial
installation in the United States is presently nearing completion. Since the
flash calciner is a dry process, the same observations and comments made on
the suspension preheater apply. Approximately 50% of the total fuel required
for the clinker production step is burned at a relatively low temperature,
with a low percent excess combustion air and quite uniform combustion gas com-
position throughout the combustion chamber. It has been reported that these
characteristics are responsible for the NOX produced by a flash calciner-equipped
kiln being significantly lower than for either the suspension preheater or long
rotary kiln.
The particulates and S02 emissions from the flash calciner-equipped rotary
kiln are expected to be approximately the same as those from a suspension pre-
heater, except when part or all of the rotary kiln combustion gas bypasses
the flash calciner and suspension preheater vessels in order to produce low
alkali cement. Although no data are presently available on the efficiency of
502 collection within the rotary kiln by chemical reaction with the calcined
cement, it is expected to be quite high. However, there remains the possibility
that the 862 emissions from a partial or total bypass system may be in conflict
with air pollution regulations.
c. Fluidized-Bed Cement Process
The fluidized-bed cement process utilizes a fluidized-bed reactor, rather
than a rotary kiln, for the production of Portland cement clinker. Although no
commercial plant has yet been built using the fluidized-bed clinkering reactor,
a semi-commercial-scale plant of 100-ton/yr capacity was built and operated
successfully for a period of several years.
The data reported indicate that the combustion gases leaving the fluidized-
bed reactor are as low in S(>2 as those of a rotary kiln and also significantly
lower in particulates. The fluidized-bed cement process is a dry process, and
therefore has none of the process water effluent which is common to the con-
ventional wet-process plant.
This process, offered to the cement industry by two U.S. firms, employs
the generation of steam as one mode of process heat recovery, and is reported
to be equivalent in overall thermal efficiency to the suspension preheater-
equipped rotary kiln which uses about 4.2 x 10& Btu/ton cement compared to
about 6 x 10ฐ/ton cement for the conventional long rotary kiln. Within the
scope of this study, such energy usage represents, the lowest consumption of
Btu per ton of cement produced.
The fluidized-bed clinkering reactor will produce cement clinker of sig-
nificantly lower alkali concentration than any of the rotary kiln-type clinker-
ing processes, all other things, such its the chemical and physical character-
istics of the raw material, being constant. This results from the significantly
higher extent of alkali volatilization in the fluidized-bed reactor and the
-------
indirect means of heat recuperation from the hot combustion gases exiting the
reactor. In the rotary-kiln types of clinkering process alternatives, heat
recuperation is by direct contact of air with raw material particles.
Therefore, the majority of the particulates contained in the combustion
gases leaving the fluidized-bed reactor are quite different from those from
any of the rotary kiln-type processes. Approximately 97% are water-soluble
potassium and sodium sulfate, and the remaining 3% are finished clinker
particles. Also, since the extent of alkali volatilization in the fluidized-
bed process is significantly greater than in the rotary kiln-type clinkering
process, the quantity of alkali sulfate emitted in the effluent combustion gas
stream discharged will be significantly highermaybe by a factor of 2 or 3
than in a comparable rotary kiln-type clinkering process. Since most of these
particulates are alkali sulfates which have been volatilized from the clinker-
ing raw materials, they are expected to be extremely fine and are more appro-
priately defined as a fume. Glass cloth filters should serve to suitably col-
lect these particulates. Although no specific data are reported concerning
the operation of such a collection device, the total pounds of particulates
emitted per ton of cement clinker produced are expected to be considerably
less than from any of the rotary kiln-type clinkering processes. This should
result in a significant economic benefit of this process in the discarding or
disposal of the particulates, especially if these alkali sulfates have a value
as a chemical raw material or plant nutrient, for example.
Actual data obtained from the operation 6f a pilot-scale, fluidized-bed
cement reactor show that the NOX concentration in the combustion gases is
significantly less than from an equivalent rotary-kiln process. The reasons
for this are that the fluidized bed reactor operates at a lower temperature
and the combustion of fuel in the fluidized-bed reactor can be carried out with
only a very small quantity of excess air. Also the high heat and mass-transfer
rates which are exhibited by fluidized beds reduce oxygen concentration gradients
within the gas phase to very low levels.
d. Conversion to Coal from Natural Gas and Oil
Coal firing of long kilns can be considered part of the base line tech-
nology, since it accounts for some 40% of the portland cement production. With
recent gas shortages and high oil prices, coal firing is expected to play a
larger role in the future. Pulverized coal can be successfully burned as the
fuel in any of the rotary kiln cement installations in the United States today.
The two main environmental consequences of switching from natural gas or oil
to coal are:
Fugitive particulate emissions and rainwater run-off which come from
the storage and handling of coal; and
the presence of coal fly ash in kiln dust which is discarded.
Coal-fired steam electric generating facilities handle and store large
quantities of coal today. The equipment and handling techniques used by these
utilities should prove equally satisfactory for the control of fugitive emissions
-------
which will attend the use of coal in cement plants. The presence of coal fly
ash In the kiln dust will increase the number of elements, and possibly the
concentration of presently existing elements, in the dust. However, this does
not appear to be in potential conflict with any environmental regulations.
4. Chlor-alkali
During the next 15 years the following evolutionary changes in the industry
are expected in approximately the order listed:
Existing graphite anode plants will be converted to dimensionally
stable anode (DSA) cells;
Deposited asbestos diaphragms will be replaced by stabilized asbestos
diaphragms.
New plants will use combinations of expandable DSA-type cells, or
wide DSA's with stabilized asbestos diaphragms;
Microporous membranes will supersede the use of asbestos in new plants
and probably be used for some existing plant modernizations;
Mercury cells which expose the industry to considerable risk in the
form of plant maloperation or accidents and which use more energy
(combining both electrical and thermal forms) than the newest DSA-
modified diaphragm cells will be slowly phased out over the next
10 years;
Perfection of the ion-exchange membrane cell will enable it to replace
economically mercury cells in existing mercury cell plants.
The effect of these changes will be a reduction of 15% or more in the
average energy consumed by the industry per ton of product. Although the present
environmental problems of the industry, with the exception of mercury cell
plants, are comparatively minor, these changes will ease existing problems.
The already small volume of chlorinated organic waste associated with the use
of graphite anodes will be eliminated, as will the solid graphite waste from
spent anodes. Traces of lead in wastewater arising from the lead used to set
the graphite will also be eliminated. Stabilized asbestos diaphragms will
greatly reduce solid asbestos waste from spent diaphragms and will essentially
eliminate asbestos fibers in wastewater. Polymer membranes, either microporous
or ion exchange, ultimately will eliminate all asbestos from the plant. Higher
purity cell gas from DSA cells will reduce the amount of gas necessarily vented
from the chlorine liquefaction system. In summary, none of these process changes
in themselves is expected to create new environmental problems. On the contrary,
the changes are expected to further reduce the amount of pollution by industry.
In all cases the environmental costs are small and these changes will be evo-
lutionary, based primarily on process economics.
26
-------
5. Copper
a. Pyrometallurgical Processes
The new pyrometallurgical processes (Outokumpu, Noranda, and Mitsubishi)
have two characteristics which make them more energy-efficient and less pol-
luting compared to conventional reverb smelters:
They utilize the heat of oxidation of sulfur and iron to supply a
part of the process energy requirements; and
They produce steady concentrated streams of SC^ suitable for the
manufacture of sulfuric acid.
The reduction in energy consumption is significant, amounting to about 30-50%
(the latter when using oxygen enrichment). The processes are quite flexible
in their ability to use any form of energy: gas, oil or coal. The reduction
in SC>2 emissions is also significant. Compared to sulfur capture of 50-70%
for conventional smelting, the new processes achieve a sulfur capture of more
than 90%. Since only concentrated SC>2 streams are produced, the cost of con-
trolling over 90% S02 in the new processes is about the same as that for 50-
70% control for conventional smelting.
The forces which would make U.S. industry adopt this technology would be
EPA regulations limiting S02 emissions and high-energy costs in the future.
Other factors should also be considered, however, The U.S. copper industry
has traditionally increased capacity by expanding and modifying existing
smelters and refineries because of the large capital investment per dollar
of revenue potential, relatively low growth in demand, cyclical nature of
demand, and international trade in refined metal. In an inflationary economy
the costs of production from existing, partially depreciated facilities would
be much lower than production costs for new facilities. New source performance
standards affecting the copper industry will constrain certain modes of capacity
expansion at existing smelters.
The sulfuric acid produced would have to be utilized or means found for
disposal. The typical^estern U.S. smelter locations are distant from major
sulfuric acid markets, and the sulfuric acid has been utilized for leaching of
marginal resources (mine dumps, tailings, oxide ores, etc.), or for making
wet-process phosphoric acid. The leaching of dumps and surface deposits with-
out contamination of groundwater is possible in the arid West, but might not
be possible in other parts of the United States. As a last resort, neutraliza-
tion with limestone or the reduction of concentrated S02 streams to elemental
sulfur would have to be considered. These options would have their own impacts
in terms of solid waste disposal.
The major shortcoming of the new processes is that their applicability to
"impure" concentrates (concentrates high in As, Sb, Bi, Pb, Zn, Se, Te, etc.)
is unproven. Until this issue is resolved, the new processes would be utilized
for building large smelters to smelt "clean" concentrates in regions where acid
markets are available and at a time when anticipated demand can no longer be
fulfilled via expansion of existing smelters.
n
-------
In spite of this, we believe that three or four new pyrometallurgical
plants (Outokumpu, Noranda, etc.) will be built in the United States by 1985-1990.
b. Oxygen Use in Smelting
The use of oxygen in smelting decreases fuel requirements and is energy-
efficient overall, because the decrease in fuel requirements is usually larger
than the energy required for oxygen separation. The use of oxygen enrichment
can increase capacities of existing units and decrease capital costs per unit
of output from new facilities. Smaller benefits are the ability to melt more
scrap and the production of more concentrated S02 streams suitable for econom-
ical recovery as I^SO^ in some cases. (Use of oxygen in place of air also largely
eliminates any NOX problems.) We believe that these advantages (and the absence
of disadvantages other than higher operating temperatures and consequently
increased maintenance) will lead to the widespread adoption of oxygen enrichment.
c. Recovery of Metals from Slag
The new pyrometallurgical processes are economically viable only if the
metal contained in the slag from the ptrimary smelting unit can be recovered.
Thus, these processes (i.e., slag laundering) are important adjuncts to the new
smelting processes and, in addition, might be used in existing smelters (e.g.,
treatment of converter slags via flotation). The processes can decrease flux
requirements, improve smelting unit operations, and aid conservation by increas-
ing the overall recovery of copper in some cases. Of the two processes, elec-
tric furnace cleaning entails somewhat lower cost, but the higher copper recovery
in slag flotation compensates for its higher costs. The energy requirements
are about equal for both processes.
Although slag flotation produces a finely ground slag which is different
from the slag from conventional processing, this slag can be placed into land
disposal areas which have been especially prepared to mitigate the possibility
of long-term emissions to the environment. Although the particular handling
method will be unique to the geological aspects of the area, it is not expected
that slag disposal will present environmental problems significantly different
from disposal of mine tailings.
d. Hydrometallurgy
(1) The Arbiter Process
We estimate that the Arbiter process would be significantly more expen-
sive for treating chalcopyrite concentrates compared to conventional smelting
and refining. We believe that this process will be used on other concentrates
with favorable mineralogy, e.g., chalcocite concentrates, in locations distant
from sulfuric acid markets and where a full-sized pyrometallurgical plant is
risky because of the cyclical nature in copper demand.
The Arbiter process and hydrometallurgical processes in general are not
energy-efficient and utilize the same or slightly more energy than conventional
smelting and refining. The leached solid wastes will require land disposal into
areas prepared so as to prevent groundwater leaching of soluble substances and
28
-------
to prevent airborne particulates. Because the plant will be located generally
in the semi-arid western United States, establishing such a disposal area can
be carried out with a high degree of confidence so that the environmental
impact would probably be no worse than with slag disposal from conventional
pyrometallurgical operations.
6. Fertilizers
a. Nitric Acid
The manufacture of nitric acid generates significant emissions of nitrogen
oxides to the atmosphere. The most widely used process for pollution control
is the catalytic decomposition of these nitrogen oxides to nitrogen and oxygen.
This process is energy-intensive and is particularly expensive for those nitric
acid plants which cannot recover this energy in the form of usable steam. The
problem is aggravated because natural gas is the required energy source. Most
existing plants are limited by regulation on the quantities of gas they can
purchase, and such natural gas is critical and non-substitutable for the manu-
facture of ammonia, which in most cases occurs at the same site. Natural gas
use for pollution control reduces the amount available for other purposes, thus
effectively reducing production. The natural gas requirement for pollution
control of a 300-ton/day nitric acid plant is 232.6 x 109 Btu/yr. This amount
could be used to produce 6,600 tons of ammonia, including process fuel require-
ments, or about 11,000 tons if used only for feedstock.
The catalytic reduction process produces steam which may be used else-
where in the plant complex, and it may be argued that this reduces the energy
input at some other point. Such an argument may not be valid for two reasons:
Not all plants have use for the steam; and
Such steam, if needed, could otherwise be provided with a fuel other
than natural gas.
Other abatement systems are becoming available and hold the promise of
lower investment and operating costs, significantly lower energy requirements,
and no need for natural gas as the energy source. Also, since the catalyst
reduction process is usually too expensive to operate in plants using low-
pressure processes to manufacture nitric acid, two or three of these alternate
processes allow more economical recovery for such plants. However, these other
processes suffer from problems of maintenance of stringent operating conditions
("molecular sieve"), inapplicability to low-pressure nitric acid processes
(Grand Paroisse), and too little actual experience (CDL/Vitok).
Costs for pollution control can be significant. The catalyst reduction
process for controlling nitrogen oxide emissions would require a 25% addition
in investment and an 11% increase in the total cost of manufacture.
The four alternative processes studied improve on these costs. The molecular
sieve and Grande Paroisse processes entail investments on the order of $1.2 and
$1.0 million, respectively, for a 300-ton/day nitric acid plant, and add $4.01
and $2.30/ton, respectively, to the cost of nitric acid. These figures are still
significant but lower than those for the catalyst reduction process. Energy
29
-------
requirements are also much lower in each of the four alternatives when compared
to the catalyst reduction process. Not only is energy use lower in these other
processes, but there is also no requirement for natural gas. Energy is consumed
as electricity only in three of the options, and electricity and fuel oil in
the molecular sieve option.
b. Fertilizer Mixing
In the drying of mixed granular fertilizers, considerable dust is generated.
It has to be removed from the process air stream before venting to the atmosphere.
In switching from natural gas to fuel oil for firing the fertilizer dryer, manu-
facturers have encountered operating difficulties with the bag filter. The
problem arises from premature clogging of the filter for a variety of reasons,
including incomplete combustion of the fuel oil, increased soot and ash forma-
tion, and, in the case of high-sulfur fuel oil, deposition of sulfate salts on
the bag. To avoid these problems, some plants have switched to propane rather
than to fuel oil. The scarcity and high price of propane make this an unlikely
alternative to be considered in the future. Based on the results of our analysis
and discussions with mixed fertilizer producers, we believe that it will be
possible to upgrade burner equipment and operating procedures and to avoid the
other two alternatives.
We estimate that only approximately 20% of the estimated 200 ammoniation-
granulation plants being considered use bag filters to collect these dusts;
the remainder use scrubbers. Thus, while the switch from natural gas to fuel
oil will present problems to a few plants, the problem is not highly signifi-
cant when viewed in an industry-wide context.
7. Glass
In the manufacture of glass products, the melting unit process is by far
the most energy-intensive. Natural gas, because of its ease of handling, clean-
liness, consistency and, until recently, its availability and low cost, is the
primary energy form used to melt glass in the United States. Because of its
scarcity and increased cost, alternative-fuel processes, principally coal-based,
will be considered. All the coal-based alternatives considered hereviz.,
coal gasification, hot gas generation, and direct coal firinggreatly increase
the emission loads from the glass furnace and, therefore, if used, will demand
larger emission control systems. Additional solid-waste and water effluent
streams also are involved in the separate processes of coal gasification and
hot gas generation and require further pollution controls. Estimated cost of
water pollution control (BATEA) ranges from $7/ton of glass for a natural gas-
fired furnace to $9/ton with coal, using best available technology. However,
one should note that at the present time, there are no proven technologies for
the effective control of air emissions from a glass furnace fired with natural
gas, nor any for the alternative fuel forms listed above. Effective scrubbing
and filter systems have not yet been demonstrated.
Except for direct coal firing, the total energy consumption of these
alternative glass melting unit processes using coal is about 25% greater than
with natural gas. As a result of substantial investments and about a 30%
30
-------
increase in operating costs, we find that processes such as coal gasification
are not economically attractive alternatives to natural gas-fired furnaces at
this time. Although economically attractive and energy-conserving, direct
firing with coal is presently beset with serious technical problems which are
related to the effect of the ash on glass furnace refractories and on glass
quality; as such, its viability as an alternative is uncertain.
The electric melting process appears to be a technically and economically
competitive alternative to gas-fired furnaces, although comparably sized fur-
naces have not yet been demonstrated. Air emissions from the glass furnace are
substantially reduced in volume in electric melting, and therefore the cost of
pollution control required is much less. However, the use of electricity as an
alternative fuel increases the pollution control problems at the power-generating
plant. Regulations relating to the environmental quality of effluents and emis-
sions from coal generation of electricity will have impacts on the availability
and cost of power for melting glass.
Process modification to utilize heat from the melting furnace for preheat-
ing the batch reduces overall energy consumption by an estimated 20 to 30%.
Air emissions from the glass furnace are reduced due to the lower fuel require-
ment. Elimination of the need for sophisticated pollution control equipment has
yet-to be demonstrated.
In general, emission species from the glass furnace, with few exceptions,
remain essentially the same, regardless of which fuel form or process modifica-
tion is used. By and large, the volume of air emission from the furnace increases
for all coal-based alternatives, whereas electric melting and batch preheat
reduce exhaust volume. Future air emission standards for glass furnaces relating
to NOX, SOX, and particulates will determine the costs of control. The choice
of alternatives would be influenced by these added costs, and the potential
high cost of pollution control could deter further development.
8. Iron and Steel
a. Recovery of Carbon Monoxide from the Basic Oxygen Process (BOP)
BOP off-gases, consisting largely of carbon monoxide, are highly combus-
tible. In conventional practice spontaneous combustion with air occurs in the
gas-collecting hood. Non-combustion systems prevent this air infiltration; they
cool and clean the CO-rich gases without burning them and make them available
as a gaseous fuel for general purposes. The recovered gas has a heating value
of about 200 to 250 Btu/scf, representing 0.4 to 0.5 x 106 Btu per ton of raw
steel. In the CO collection system, the dust is less oxidized than in the con-
ventional combustion system, contains a smaller percentage of submicron par-
ticles, and is easier to collect. Treatment of water used in scrubbing is
facilitated because of the more rapid settling characteristics that result.
Solid waste disposal methods are unaffected.
Compared with a total combustion system, the CO collection system with a
gas holder will cost about 60% more in capital, mainly because of the need for
a separate and independent hood and scrubber for each furnace.
31
-------
Because of the cyclic pattern of gas generation, the need for a gas holder
of several million cubic feet capacity or larger, the land needs associated
with the gas holder, and the logistical problems in piping a collected gas to
end-users, we find that industry regards this source of fuel gas to be sup-
plemental to its other fuel sources. However, if the collected gas can be
utilized and credited at $2/10^ Btu, the non-combustion collection system offers
lower operating costs than the conventional BOP pollution control equipment.
Overall we believe that the iron and steel industry is expected to imple-
ment non-combustion collection and recovery of the fuel value in BOP off-gases
in new installations built over the next 15 years. Because a large proportion
of the remaining open-hearth capacity will be replaced by BOP, and the total
capacity of the industry will increase at an average rate of about 2.5%/yr,
BOP capacity by 1990 may be expected to increase 80-100 million tons above the
1973 level. A significant fraction of such capacity can be expected to be
achieved by "rounding out" (i.e., capacity increases achieved by going from a
two-vessel to a three-vessel BOP shop). Logistical factors, such as plant lay-
out and location, are likely to have a major influence on the actual number of
steel plants adopting the non-combustion recovery system. However, for every
million tons of installed production capacity adopting the non-combustion sys-
tem, about 4.4 x 1QH Btu are recoverable in the form of a supplemental fuel
source.
b. External Desulfurization of Hot Metal
In the blast furnace the sulfur content is controlled by adding limestone
to form a sulfur-bearing slag and by limiting the sulfur content of the metal-
lurigcal coke. External desulfurization is achieved by injecting sulfur-retaining
reagents (e.g., calcium or magnesium compounds in an inert gas such as nitrogen)
into the hot metal from the blast furnace. These compounds form a sulfide slag
that must be skimmed off prior to pouring into the BOP. This latter procedure
either permits limestone and coke rates to be reduced, or alternatively allows
the sulfur content in the coke to be increased without charging more limestone
to the blast furnace.
Since sulfur content specifications in finished steels are decreasing
slowly with time, an important parameter in sulfur control is the quality of
the coke (or coal) supply available to each company. When the coke contains
more than 1.2 - 1.5% sulfur, we believe that external desulfurization becomes
economical. Aside from coke-rate implications, external desulfurization per-
mits a better consistency in the sulfur content of the hot metal charged to
the BOP, thereby smoothing the steelmaking operation and increasing its yield.
From an environmental viewpoint, external desulfurization represents a
potentially new source of air pollution, including fine carbon particles, the
characteristics of which have yet to be defined. (In addition, demand for
desulfurizing agents may have an environmental impact in industries producing
such compounds.) From an energy-usage viewpoint, external desulfurization
allows substitution of higher sulfur metallurgical coal for less plentiful,
low-sulfur metallurgical coal, thus expanding the domestic reserves.
32
-------
We believe that this process option looks sufficiently attractive, so
that several external desulfurization installations can be expected to be built
during the next 15 years.
c. Dry Quenching
The dry quench system replaces the wet one using water to quench the incan-
descent coke pushed from a coke oven. In the dry quench system, sensible heat
from the coke is transferred to the inert gas and can then be partially recovered.
The physical facilities involved in either method of quenching are physically
separate from the coke ovens. The incandescent coke is pushed from the oven and
falls into a tracked car in which it is transported to the quenching area. Thus
the emissions which occur during the pushing operations from the ovens are
altogether a different concern from the emissions which occur during quenching
operations, but there can be a relationship in current design concepts, depend-
ing on the type of tracked vehicle used to transport the incandescent coke.
While dry quenching of coke is practiced in the U.S.S.R., there are no
installations in the United States. Russian authors claim that dry quenching
produces a higher grade coke and reduces coke rate in a blast furnace. However,
this claim has to be demonstrated for U.S. coals. Moreover, less production of
coke breeze is claimed for dry quenching, but many situations may exist in
which this could generate a shortage of breeze for sintering plants. In addition,
the physical installation is more complex than that for wet quenching, and this
complexity increases the capital cost significantly. The difference between a
dry coke quenching station with the associated tracked vehicle and a wet quench-
ing station is at least $7 million and possibly twice as much as this for an
annual production of 1 million tons of coke. Moreover, it appears that a standby
quenching station would be needed as a backup quench system which could add
another $2.5 million to the capital investments. Only very large plants, using
several quenching towers, could waive the requirement for a standby quenching
unit. The only demonstrated benefit of dry coke quenching is the significant
amount of energy recovery. This energy represents about 1.1 million Btu per ton
of coke, which is equal to the energy needs of the coke byproduct plant.
The ircm and steel industry probably will not adopt dry quenching of coke
on any significant scale during the next 15 years. This situation could change
if it can be demonstrated that dry-quenched coke from U.S. coals can measurably
reduce blast-furnace coke rates. Supporting experimental evidence so far is
lacking.
d. Direct Reduction
New iron units (oxide pellets, lump ore, etc.) can be partially reduced
in the solid state by reaction with a reducing gas mixture (CO and H2) at
temperatures ranging from 1470ฐF to 2000ฐF. These prereduced materials are
also called sponge-iron or metallized materials, because up to 95% of their iron
content exists in the metallic state. They can partially replace scrap in the
steelmaking electric arc furnace, be charged to the blast furnace to increase
its productivity, or used In the oxygen steelmaking shop in lieu of scrap.
-------
The uiost advanced direct reduction technology proven to date is based
on the use of natural gas or a petroleum-based hydrocarbon as the energy
source. Technology based on coal employing the rotary kiln, is also available
(SL/RN*, Krupp, Kawasaki), but demonstration on a large scale for acceptance
in the United States is still at least several years away. A successful large
demonstration is vital for widespread application of this technology in the
United States.
The alternative use of coal for direct reduction purposes would be a
gas-oriented process utilizing a coal gasification step to produce the necessary
.high-temperature reducing gases. Although the technological approaches are
clear and research and development are underway, commercial demonstration of
this alternative lies farther in the future because it has not proven econom-
ically attractive.
Pollution control problems with the direct-reduction electric furnace
route are generally less severe than with the blast furnace route. A major fac-
tor in this respect is the elimination of the need for coke ovens. While the
rotary kiln, direct-reduction electric "furnace steelmaking route eliminates
dependence on metallurgical coal, it consumes about 40% more energy per ton of
steel than the blast furnace, coke oven, basic oxygen furnace route. Its energy
conservation potential is one of form rather than quantity.
The two routes are about equally costly, in terms of both capital and
operating expenses. Transportation costs and other site-specific economic con-
ditions, together with reliability expectation differences, presently favor
(he traditional approach via the blast furnace for the bulk of the steel
industry. Because these total cost estimates represent relatively small dif-
ferences between large numbers, it will be worthwhile to re-examine this judg-
ment periodically.
Certain locations in the world have the potential for low-cost manufacture
of semi-finished steel products via direct reduction and electric furnace steel-
making, e.g., Venezuela with iron ore and surplus natural gas resources and the
Middle East with surplus natural gas resources. Long-distance movement of metal-
lized pellets, or even of semi-finished products in international trade, could
become of major importance in facilities planning within the next 15 years.
In view of these findings, the industry should be expected to treat the
subject of direct reduction and the production of metallized iron units cautiously
It may be more realistic to expect that the U.S. industry will import increasing
quantities of metallized or partially reduced pellets within the next 15 years.
While a few plants may be built, the prospects for large-scale, direct-reduction
processing in the United States within the next decade do not look optimistic.
*SL/RN - Stelco-Lurgi/Republic Steel, National Lead.
34
-------
9. Olefins
The major impact of the current energy crisis on the olefin industry
will be to force the use of heavier feedstock in most new olefin plants.
These heavier feedstocks - naphtha and atmospheric gas oil - do not give as
high a yield of ethylene as do the lighter feedstocks - ethane and propane.
Furthermore, the conversion of naphtha or gas oil to ethylene is more complex
and requires a significantly higher plant investment than is required for an
ethane-propane (E-P) plant. The heavier liquids used to produce olefins almost
always contain more impurities than E-P, with sulfur being the major impurity
of environmental concern. The increased sulfur content of the feedstocks
increases the environmental controls necessary for the olefin facility.
Counterbalancing the drawbacks associated with the use of heavier feed-
stocks is a significant increase in the production of valuable byproducts
over those produced when using an E-P feed. Thus, although the total energy
required to produce a pound of ethylene increases with heavier feedstock, the
energy required per pound of useful product decreases. Nevertheless, the
estimated cost of producing ethylene from naphtha or gas oil would be about
30% higher than the cost of producing ethylene from an E-P feedstock, even
though reasonable byproduct credits were utilized.
The estimated costs for environmental controls to satisfy existing or
anticipated regulations fall between 0.5 and 1.75% of the cost of producing
ethylene. The lower percentage is for E-P cracking and the higher percentage
is for gas oil; the cost of environmental controls using naphtha feedstock
falls in between. The energy requirements for environmental control are less
than 0.1% of the total energy required for the production of ethylene. How-
ever, even small variations in relative pollution control costs or manufactur-
ing costs will have a significant impact due to the size and competitive,nature
of the industry.
One of the main environmental impacts resulting from the use of heavier
feedstocks is indirect. When naphtha or gas oil is cracked to produce olefins,
a significant quantity of pyrolysis fuel oil is produced as a byproduct. If
the sulfur content of the feedstock is above a certain level, the sulfur con-
tent of the byproduct fuel oil will be high enough to preclude its use as a
fuel without further desulfurization or flue gas desulfurization at the point
of use. Economical technology is not currently available for the direct de-
sulfurization of the pyrolysis fuel oil produced and flue gas desulfurization
is also not economically attractive for multiple combustion units. Therefore,
most olefin producers would prefer to choose heavy liquid feedstock materials
with a low enough sulfur content to ensure that the sulfur content of the by-
product fuel oil would be acceptable as a fuel under present regulations.
This preference puts undesirable restrictions on the choice of feedstock.
Alternatively, the olefin producer could desulfurize the feed in a petroleum
refinery-type operation prior to cracking. This would put the non-integrated
chemical companies at some disadvantage to the petroleum companies integrated
with olefin production.
35
-------
Other technology is being developed for producing olefins from other
feedstocks and for utilizing conventional feedstocks more efficiently.
Developmental work is underway to utilize vacuum gas oil, vacuum residues or
resids, crude oil, and coal as possible feedstocks for olefin production.
Developmental work is also being done on the thermal cracking of naphthas in
the presence of hydrogen to improve the yields of ethylene. The olefin industry
started this developmental work so that it could utilize these less desirable,
but more available, feedstocks. It is generally believed that this new tech-
nology will not have significant impact on the olefin industry within the next
10 years.
At present there are no federal standards on the control of fugitive
emissions from an olefin facility. Since olefins - ethylene, in particular -
have a very strong odor, the industry has apparently already controlled these
emissions. If very stringent controls on fugitive emissions were promulgated,
the economic impact of meeting them could be significant. Stringent control
of fugitive emissions would most likely have the same type of impact on all the
process options studied as well as on the technology that is still in the
development stage.
Regulations controlling emissions from sulfur-recovery facilities have
an impact on the olefin producers in their choice of sulfur-recovery technology
to be incorporated in the olefin production facility. The technology required
to meet the current regulations is well established and is not considered a
serious economic burden.
10. Petroleum Refinery
The five industry process changes assessed in this study included:
Direct combustion of asphalt in heaters/boilers;
Asphalt conversion by hydrocracking (H-oil);
Asphalt conversion by Flexicoking ;
Internal power generation; and
Hydrogen generation by partial oxidation.
These options were evaluated within the context of "typical" existing
refineries representing actual refinery clusters existing in the Petroleum
Administration for Defense (PAD) districts selected. Each of the above
options achieves an energy form value improvement.
Within the framework of the comparisons set forth, we find that the
implementation of the above changes will have a small impact on the control
of refinery wastewater. The effect on the characteristics of the treated
effluent, the type of treatment required to conform with regulatory require-
ments, and the cost of wastewater treatment would not preclude the selection
of any of the alternatives. Asphalt conversion by Flexicokingฎ has the
highest wastewater treatment cost, and the cost penalty is about 25% of the
36
-------
total pollution control cost and about 7% of total process operating costs,
including pollution controls.
There are, however, some identifiable impacts in regard to air pollution
regulations, particularly S02 emissions. All of the options involve utiliza-
tion or conversion of petroleum residues which contain a disproportionate part
of the sulfur found in crude oil. Removal of this sulfur to limits set for SOX
emissions has a significant impact on those options which involve the direct
combustion of asphalt (vacuum bottoms) for heaters/boiler or power generation.
In the case of asphalt combustion for heaters or boilers, operating costs for
flue gas desulfurization (FGD) account for more than half of the total operating
cost. This is indicative of why petroleum refiners'have preferred to comply
with sulfur dioxide regulation by fuel blending rather than by installing FGD
systems on process heaters and boilers. The reason FGD is not generally applied
in refineries is that there are numerous small (by electric utility scale)
sources within a specific refinery which require control- FGD systems for
the capacities normally encountered with process heaters have high unit costs.
"Internal power generation" is similarly impacted by the high cost of a
small flue gas desulfurization system. A potentially attractive modification
to Internal power generation is the integration of electric power generation
with process steam generation through the use of a topping cycle (steam pressure
reduction with back-pressure turbines). This approach could conserve total
energy in the refinery in contrast with the other options which just upgrade
form value. Hence, some movement in this direction may be mandated by FEA,
economics not withstanding. Asphalt combustion would be a natural choice of
fuel for this scheme, were it not for the high cost of stack pollution con-
trol. Again there is a case for developing small source FGD technology, per-
haps utilizing typical refinery resources such as CO, H2ป amine plants, and
sulfur reduction processes.
A possible alternative to asphalt combustion in a refinery is to sell the
asphalt to an electric utility for burning in large boilers equipped with FGD
systems. This would reduce the unit cost of pollution controls due to the
improved economies of scale, but would entail cost or technical difficulties
in handling and transporting the asphalt. Also, this may be in conflict with
efforts aimed at reducing the amount of petroleum used by electric utilities.
The Impact of EPA regulations on the residuum upgrading processes, such
as H-Oil and partial oxidation, is not unreasonable and, in most cases, the
additional control required represents an incremental change to an existing
sulfur recovery system*
The choice of alternates for heavy resid conversion is particularly
dependent upon the type of crudes processed at a given refinery and the par-
ticular markets for asphalt, coke and distillate fuels. Furthermore, the
impact of pollution regulations is not particularly great for these options;
consequently, pollution regulations are not seen as an impediment in the
application of these technologies.
37
-------
11. Phosphorus
Phosphorus and its compounds are important requirements for many indus-
tries, and the establishment of new plants to support the growth of phosphate
products is assured. The principal requirements are in fertilizers, food
chemicals, industrial phosphates, and detergents. Two different technologies
are currently practiced, and they serve two largely different market sectors:
The fertilizer requirement will continue to be supplied in the
conventional manner by digestion of phosphate rock with sulfuric
acid in the so-called wet-process route. The process produces
phosphoric acid containing many impurities, but it meets the re-
quirements set by the fertilizer industry.
Elemental phosphorus, food-grade chemicals, and industrial phos-
phates requiring high-purity phosphoric acid are based on elemental
phosphorus produced in an electric furnace.
From an overall energy standpoint, the wet process is much more efficient than
the electric furnace process. It requires about 16 x 10ฐ Btu/ton ?2ฎ5 product,
about one-fifth of the 79 x 10^ Btu/ton required for the electrothermal route
(when electric power is converted to an approximate fossil fuel equivalent
using 10,500 Btu/kWh).
a. Use of Byproduct Sulfuric Acid
The wet-process industry can operate with purchased byproduct sulfuric
acid rather than with sulfur which is converted on-site. The price of sulfuric
acid for such an operation would probably be negotiated with the result that
the cost of phosphoric acid product would be competitive with that from an
ordinary wet-process acid system. In addition to purchasing sulfuric acid, a
plant without an on-site sulfuric acid plant would require steam normally
supplied by the acid plant. This steam, amounting to about 3 million Btu/ton
P205, might be generated with an on-site steam boiler, or it could be purchased
from a utility if the plants are adjacent. Pollution problems directly asso-
ciated with phosphoric acid would be the same; the pollution problems normally
part of the sulfuric acid plant would be eliminated.
b. Strong Acid Process
An alternative for wet-process phosphoric acid production is to operate
the digestion system at phosphoric acid concentrations of about 50% P20c.
Evaporation of the product acid is not required under these conditions. The
digestion system must be operated at a temperature of about 212ฐF and the cal-
cium sulfate is separated as the hemihydrate. The process is claimed to be
competitive with the standard wet-process system and would be particularly
attractive at an integrated fertilizer production site where additional process
units could use the steam no longer required for evaporation. Evolution of
fluorides from the digestor could be expected to be more severe than with the
standard wet-acid system, but the evaporator vent stream is eliminated. On an
overall basis, pollution control problems could be expected to be about the
38
-------
same as with the standard wet-process system. The adoption of a strong acid
process with the use of byproduct sulfuric acid would be attractive on an
energy basis.
c. Cleanup Processes vs. Furnace Acid
To supply phosphoric acid for food-grade chemicals and industrial phos-
pha.tes, immediate expansion of the electric furnace industry is not foreseen
because of the high capital costs required, the shortage and cost escalation
of electric power, and the uncertainty of costs for pollution control. As
requirements for detergent phosphates increase, it is likely that the oppor-
tunity for their production by cleaning wet-process acid will be exploited.
There are two methods of modifying the wet'-process system so that the phos-
phoric acid produced is clean enough for production of detergent phosphates:
1) the chemical cleanup route, relying on sulfuric acid to digest
phosphate rock, and
2) the solvent extraction systems, using hydrochloric acid for diges-
tion of phosphate rock.
The economic viability of incorporating one of these methods with a wet-process
plant, instead of production from elemental phosphorus, depends to a large
extent on the price at which phosphate rock, sulfur, or hydrochloric acid can
be made available to a given plant. Compared with the 79 million Btu/ton
phosphoric acid required in the base line electric furnace route, both cleanup
alternatives are energy-efficient, requiring 3 to 16 million Btu/ton phosphoric
acid, depending on whether or not the heat of combustion of sulfur is credited.
The base line electrothermal phosphoric acid and both cleanup routes to phos-
phoric acid generate wastewater streams which must be treated prior to dis-
charge. Some of the pollutants present'in the treated effluent are common to
all three alternatives, while others are characteristic of specific alterna-
tives . In general terms:
All three alternatives produce treated effluents which contain low
(but not insignificant) amounts of soluble phosphates and fluorides.
The treated effluents from the elemental phosphorus alternative and
the chemical cleanup alternative both contain moderately high con-
centrations of sulfates.
The treated effluent from the wet process-solvent extraction alter-
native is generally devoid of sulfates, but contains an extremely
large quantity of calcium chloride. The wastewater also contains a
moderate amount of n-butanol solvent.
Economically feasible wastewater treatment control technology is available
for each of these alternatives. In our assessment, the high concentration
(13.6%) of calcium chloride present in the treated effluent from the wet process-
solvent extraction alternative will render it unsuitable for discharge into
most receiving streams. For estimation of pollution control costs we assumed
that the most feasible disposal method for this waste stream is deep-well
Injection (where permitted).
39
-------
The elemental phosphorus route alternative (furnace acid) is the most
expensive, while the wet process (chemical cleanup) alternative is the least
costly. The costs are sufficiently close to one another so that plant-to-
plant variations and site-specific factors could easily upset the relative
cost ratios. In general, it can be concluded that no one process has a very
significant treatment cost advantage over the other. It should be noted that
deep-well disposal, although perhaps economically feasible, is only a viable
option in regions where' geological formations are favorable and local and
Federal regulations permit such disposal. If the calcium chloride brines
were required to be converted to calcium chloride salt, the operation would
be energy-intensive. Furthermore, the major markets for calcium chloride are
in road deicing, especially in the northern tier of States and Canada, and in
the cement industry where it is used to remove sodium and potassium as the
chloride. In either instance the potential for high concentrations of chlo-
rides entering ground or surface waters has not been decreased from the poten-
tial that exists at the plant, although the distribution and localization would
change. In fact, road deicing would result in a much wider potential distri-
bution with probably greater impact on drinking and surface waters. Obviously,
the disposal of brines is a significant problem. The cost of wastewater treat-
ment (as arrived at within the bases of this study) is a relatively small
percentage of the total production cost.
None of the wastewater treatment processes are highly energy-intensive,
and even the highest wastewater treatment energy consumption is a very small
fraction of the total process energy consumption.
d. Solid Waste Related to Wastewater Treatment
f I- - I .. I. ...... Mill I I
All three systems process significant amounts of wastewater treatment
sludge. In each case the sludge contains large amounts of calcium fluoride
and calcium phosphates and cannot be disposed of indiscriminately. Estimated
quantities of wastewater treatment sludge are:
Elemental phosphorus route
84,750 ton/yr sludge wet basis;
Wet process - neutralization/precipitation
80,700 ton/yr sludge wet basis;
Wet process - solvent extraction
45,500 ton/yr sludge wet basis.
Although the mass of sludge from the solvent extraction alternative is
about one-half that of the other alternatives, it is more environmentally
objectionable due to the high concentration of soluble chemicals which could
rapidly leach from the sludge.
We conclude that, from a water pollution standpoint, the wet-process,
sulfuric-acid, chemical cleanup (neutralization/precipitation) alternative is
the most favorable from an energy/environmental viewpointป The wet process-
solvent extraction is the least favorable, solely due to the serious calcium
chloride brine disposal problem.
,40
-------
12. Pulp and Paper
Of the many processes considered in the pulp and paper sector, four were
selected for detailed evaluation in the Industry Assessment Report, namely:
Rapson effluent-free kraft process;
Alkaline-oxygen pulping;
Thermo-mechanical pulping; and
De-inking of old news for newsprint manufacture.
a. Rapson Effluent-Free Kraft Process
The first commercial installation of the Rapson effluent-free kraft process
is presently under construction at the Great Lakes Paper Company in Thunder
Bay, Ontario. The process is designed to p.roduce none of the BOD, suspended
solids, and color that characterize effluents from the chloride/caustic bleach-
ing system used with the conventional kraft process. (It does not affect the
solid waste or air emissions, however.) The process maintains all the desirable
physical characteristics of the product and reportedly can be retrofitted into
existing kraft mills.
When compared with the conventional kraft pulping and bleaching methods,
the technical/economic evaluation of the Rapson process indicates that it
would provide:
Significant energy savings (7 million versus 2 million Btu/air-dried
ton, respectively);
Cost savings ($290 vs. $259 per air-dried ton, respectively).
Further, since much of the overall water effluent associated with bleached
kraft pulp manufacture originates in the bleach plant, the elimination of
effluents from this source, as contemplated by the Rapson process, would cause
a major reduction in the overall water effluent from an integrated kraft pulp
and paper mill.
Should the first installation prove to be technically and economically
successful, the new process could greatly alleviate the water pollution prob-
lems confronting a large segment of the U.S. pulp and paper industry. It
might well be Included in the design of all new .bleached kraft pulp mills and
retrofitted into existing ones as a more convenient and less costly way of
avoiding the color produced by traditional kraft pulp bleaching processes.
The alternative color-removal technique, lime treatment, entails a lower initial
investment, but the potential annual savings with the Rapson process could
return the additional capital expenditure in 1 or 2 years.
41
-------
Results from the first commercial Installation should be available
within 2 or 3 years to validate the postulated benefits of the Rapson process.
If the experimental results are confirmed, the process could be adopted by a
significant portion of the bleached kraft industry within the next decade.
b. Alkaline-Oxygen (A-0) Pulping
The first A-0 pulp mill has been installed by Weyerhauser in Everett,
Washington. If the process is successful, adoption of the A-0 pulping process
by the industry could have some long-range beneficial effects; particularly
the alleviation of much of the air and water effluent problems presently con-
fronting conventional kraft mills. Although it would have no significant
effect upon solid -waste characteristics, the total reduced sulfur (TRS) and
the odor problem typically associated with the conventional kraft process
would be eliminated, and the color problem associated with the conventional
kraft pulping and chlorine/caustic bleaching processes would be reduced by
about 50%.
On the basis of available data, the A-0 process is not a direct substitu-
tion for the kraft pulping process, because the resultant product has inferior
strength characteristics. More promising areas of possible product/process
substitution would be in applications for bleached chemical pulp (both kraft
and sulfite) in which high strength properties are not essential. These poten-
tial applications comprise less than 50% of the total bleached chemical pulp
usage.
In view of the early stage of its commercial development, sufficient
"hard" data are unlikely to be available within 2 or 3 years to assess the
technical and economic viability of the A-0 process. The single installation
presently in the startup stage constitutes less than 0.5% of the total U.S.
bleached pulp capacity; accordingly, any beneficial impact from its commer-
cial development will not be felt within the next 3 years. Furthermore, because
of the extended lead time needed for the design and construction of a mill using
new technology, the successful development of A-0 pulping is likely to have
only a minimal impact upon the industry within the next decade.
c. Thermo-Mechanical Pulping
As an alternative to chemical processing, thermo-mechanical pulping (TMP)
is one of three methods by which mechanical techniques (grinding) are used to
reduce wood raw material to papermaking fiber; the other two are stone ground-
wood and refiner mechanical pulping (RMP).
TMP, a recently developed alternative technique, has been successfully
demonstrated in a few commercial installations. Its wider application is
assured because of overall cost savings in the manufacture of finished product.
This results from the fact that the physical strength properties of TMP pulp
are superior to those of conventional RMP. Most paper products are made from
a blend of chemical and mechanical pulps; chemical pulps are stronger, but
more expensive than mechanical pulps, so papermakers use as much of the latter
as they can without unduly weakening the product. The substitution of TMP for
RMP permits a higher percentage of mechanical pulp and thus a lower cost.
42
-------
The picture from an energy standpoint is somewhat different. In terms
of energy intensitivity, IMP and RMP are about equal, but both are higher
than chemical pulp. As a result, the higher proportion of mechanical pulp
that is made possible by the IMP process also slightly increases the amount of
energy used in making the finished product.
Water pollution resulting from the manufacture of the finished product
(made from a combination of chemical and mechanical pulps) is little affected
by TMP, although the BOD load is slightly higher (about 20%) than with the
conventional RMP process. Air emissions are not a problem with any of the
mechanical pulping processes, so the industry's acceptance of the TMP process
would not affect the characteristics of the mechanical pulping operation.
However, as less chemical fiber would be required in the finished product, a
smaller volume of air emissions would be produced in its manufacture.
The wider use of TMP could alter the disposal pattern of sawdust and
shavings, which are part of the solid waste from a lumber manufacturing opera-
tion. These materials are presently burned for their heat value, sold as
animal litter or, in some cases, used as cellulosic raw material in pulp manu-
facture. The higher pulp strength properties attainable via TMP vs RMP would
permit greater use of these byproducts in higher added-value applications.
Water pollution effluents could be affected by a significant modification
of the TMP process - cheml-thermo-mechanical pulping (CTMP). In this process,
small amounts of chemicals (1 to 2% caustic and sodium sulfite) are added to
the wood chips prior to their mechanical attrition. The purpose of the chemi-
cal is to solubilize some of the organic adhesive that binds the papermaking
fibers, thus facilitating their separation, while maintaining maximum strength
characteristics.
While there is little commercial experience to quantify the effect of
CTMP on energy and pollution, it is reasonable to postulate that there would
be a reduction in energy usage in the defibering operation and that additional
dissolved organic material would appear in the water effluent stream. Further,
it seems probable that the low quantity of organic materials (5-10%) and
chemicals (1-2%) appearing in the water effluent would make it economically
unattractive to burn the "spent liquor" to recover its heat and chemical value,
as is normally done in "full chemical pulping." Unfortunately, sufficient data
are not available at this time to quantify more precisely the pollution con-
sequences of this variation of the TMP process.
d. De-inking of Old News for Newsprint Manufacture
The de-inking of old news for newsprint manufacture uses only about 25%
as much energy as that required for the alternative manufacturing processes
used to produce the combination of chemical and mechanical pulps present in
de-inked pulp. Our contacts with mills that plan to install de-Inking facili-
ties indicate that they expect no problems in complying with water effluent
emission regulations; thus, there appears to be no potential conflict with the
regulations as the result of broader application of de-inking. Further, since
the amount of chemical fiber that is added to the de-inked fiber in the manu-
facture of recycled news may be reduced or entirely eliminated, air emissions
43
-------
associated with the production of kraft pulp* would be much less of a problem
in recycled newsprint manufacture.
With regard to solid waste, the use of de-inking would entail no signifi-
cant change at the plant site; the benefit that would accrue from recycling
newsprint would be to alleviate the solid waste problem facing major metro-
politan areas. Waste paper constitutes 30-40% (by weight) of our total
municipal solid waste, and about 15% of the waste paper is newsprint. Accord-
ingly, the de-inking of old news could make a measurable reduction in the
amount of solid waste in cities.
13. Textiles
There are many potential "energy-conserving" unit operations being intro-
duced commercially or under development, some with EPA sponsorship. In this
study we defined "model" textile mills which would maximize the use of energy-
conserving "unit process" options as follows:
Advanced aqueous processing (referred to as "advanced processing")
in which the sequence of unit operations is designed to minimize
water and energy use; and
fl Solvent processing in which a solvent (such as perchloroethylene) or
solvents are used rather than water to transfer chemicals to and
from the fabric.
a. Integrated Knit Fabric Mill
(1) Advanced Aqueous and Solvent Processing
In advanced aqueous and solvent processing overall energy use is decreased
by 50%, although electricity use is increased through substitution of air
extraction for conventional drying. The same substitution, together with more
efficient operation of the heat-set tenterframes** (drying frame), reduces
natural gas use considerably. Reduction in steam use is achieved through max-
imum water economy and recycle of rinsewaters.
Solvent processing shows a 70% reduction in overall energy use, although
steam is still required for evaporation and recovery of the solvent and for
stripping the solvent after the finishing operation.
Advanced aqueous processing does not reduce the pollution loading-because
the same chemicals are used, but the lower hydraulic load reduces pollution
control costs and improves the efficiency of effluent treatment. All solvent
*There are alternative methods for making chemical fiber that do not have an
air emission problem, but the quantity of these materials used is much
smaller than that of kraft pulp in this application.
**Although waste heat recovery per se is outside the scope of this study, we
have included a heat recovery unit attached directly to the tenterframe
which preheats the incoming air as a process modification.
44
-------
processing practically eliminates the water pollution potential, but the
chemicals removed from the solvent during recovery represent a solid waste
disposal problem. Recovery of solvent for recycling must be very high for
economic reasons, but the solvent losses may still represent an air pollution
problem. Solvent recovery systems are designed by the manufacturers to meet
present air pollution control regulations and environmental health regulations,
but there is considerable concern on the part of EPA and OSHA that chlorinated
solvents are a particular hazard which may require more stringent regulation.
This factor may be a potential deterrent to the adoption of solvent process-
ing, although at the present time the technical limitations are probably more
important.
The capital investment required for advanced aqueous processing is not a
great deal higher than that for the conventional technology; therefore, this
would not be the determining factor in introducing the technology to a new
plant or processing line. However, because of the small leverage of energy
costs compared to capital costs, there is no major advantage in terms of
reduced product costs which might encourage the adoption of this technology at
a rapid rate throughout the industry. The incremental capital costs for
advanced processing over the base line are adequately repaid from reductions in
operating costs and pollution control costs. Therefore, whenever new or
replacement capacity is required, advanced processing does have an economic
(and environmental) advantage. It also has lower energy costs, thus providing
the manufacturer with some protection against future fuel and energy price
increases. It is also feasible for the unit operations which make up the
advanced processing to be adopted piecemeal by existing plants with a con-
sequent energy saving and lowering of pollution control costs.
(2) Solvent Processing System
Similar comments apply to the solvent processing system, but there are
some additional reservations. Equipment for solvent processing is commercially
available and being used in textile mills, generally in more specialized appli-
cations where solvent processing is essential because of the nature of the
chemicals used or because an improved product is obtained. At present its
most widespread application is in scouring of knit goods. An all-solvent
processing line would have the advantage of completely eliminating the waste-
water effluent, but as yet, the technology is not sufficiently well demon-
strated to show that an all-solvent processing line is commercially feasible.
The dyeing step is particularly troublesome; in spite of much work, there are
still severe limitations in the type of dyes and range of colors that can be
applied from a solvent medium. In particular, the dyeing of polyester by
solvent methods has not been adequately demonstrated, and this is one of the
most Important fibers being used in knit fabric today.
b. Integrated Woven Fabric Mill
Advanced aqueous processing offers a 57% reduction in energy consumption
by reduction in the use of electricity, steam, and natural gas. Reduced
electricity and steam consumption results from better water economy and the
use of less energy-intensive technology. Lower natural gas use comes from
optimization of the tenterframe operations for drying and heat setting which
45
-------
Includes the addition of a heat recovery unit on each tenterframe. This reduc-
tion is a result of optimization of 23 different unit operations in a particu-
lar sequence for the processing of a 50/50 polyester/cotton fabric. Many
textile mills have much more diversified processing and the energy savings
may be less, but we would still expect them to be substantial.
It is assumed that the wastewater effluent from base line and advanced
processing are both treated by biological methods. As with the knit fabric
mill, the decreased hydraulic load will reduce treatment plant size and costs.
The use of polyvinyl alcohol (PVA) size and its recovery reduces the hydraulic
load and the pollution loading (BOD and COD). Potential air and solid waste
effluents are minor. Some organic compounds (degradation products of finish-
ing chemicals) escape with the flue gas, but with good operation the levels of
organics fall below the levels set by regulation. Other minor amounts of
finishing chemicals may end up as a tarry residue in the tenterframe, which is
periodically removed for disposal.
Adoption of advanced.processing does not greatly reduce product cost
because of the high capital investment required for a new woven mill. The
incremental costs of capital investment.for advanced processing over conven-
tional processing in a new mill are relatively small and show a good payback
in terms of lower energy use and resource recovery. The lower pollution load-
ing from PVA recovery and reduced water use will also reduce the size and cost
of the biological treatment plant for the wastewater effluent. Therefore,
adoption of advanced processing appears likely for much of capacity replace-
ment and expansion. PVA recovery is attractive economically and environ-
mentally, and will be used if it can be shown to be applicable to a wider
range of fiber combinations.
C. IDENTIFICATION OF CROSS INDUSTRY TECHNOLOGY
Within the industry sectors investigated in these studies, several generic
types of process technologies or problem areas were identified as follows:
Applications of preheating,
4 Sulfur removal from hot gases,
Use of fluidized bed,
Heat recovery,
NO emissions,
Use of oxygen,
* Use of electric furnace, and
Use of solvent.
46
-------
We recognized that some of these "common type" process concerns had
applications in fields outside the scope of this study, as further discussed
below.
1. Preheating
Preheating of solids prior to processing has been identified as an energy-
conserving process change. In the glass sector, agglomeration and preheating
of the charge offer the potential of reducing dust carryover from the glass-
making furnace and somewhat reducing NO and SOX emissions from high-sulfur fuel
because less fuel is used. In the cement sector, the suspension preheater/
flash calciner was shown to be an energy-conserving process change with the
potential of reducing NOX emissions because less fuel is used. In addition,
we are aware that in the industries examined preheaters are being considered
or used in:
producing of blast furnace coke from coal, and
preheating ferrous scrap charges to electric furnaces or basic
oxygen furnaces.
Preheaters take a variety of forms, including rotary kilns, shaft furnaces,
fluidized beds, batch devices, and the like, and each is designed with a
particular application in mind. Due to lower fuel usage, one can generally
expect reduced SOX, NOX, and particulate emissions.
2. Sulfur Removal from Hot Cases
In several process alternatives using gasified coal, particulates and
sulfur removal are accomplished at low temperatures, and the clean product
gases are then reheated to the temperature desired for the chemical reaction.
Examples are found in direct reduction of iron ore, glassmaking, and ammonia
manufacture. Considerable energy may be saved if particulates, heavy metals,
and sulfur could be removed at high temperatures. Such technology producing
a hot, clean reducing gas (consisting largely of Hฃ and CO) would have
applications in many other industrial sectors either as a clean fuel or as a
feedstock such as for substitute natural gas, methanol manufacture, and
hydrogen generation (via the water gas shift reaction) in petroleum refining.
Overcoming cooling/reheating of such gas streams reduces energy use and its
concomitant pollution.
47
-------
3. Fluidized Beds
Fluidized and ebullated beds are being considered as new processing
tecnniques in several industries. Examples include:
flash calciner/suspension preheaters in the cement industry,
fluidized bed cement process,
hydrocracking (H-Oil reactors) in the petroleum industry,
flexicoking which is a new process in the petroleum industry for
converting heavy bottoms to light liquids and gas. In this process
sulfur contained in the bottoms combines to form H_S which, in turn,
can be converted to elemental sulfur using conventional technology.
Since first applied commercially in 1942 to the catalytic cracking of
heavy petroleum fractions, fluid-bed technology has experienced widespread
application including:
fluid coking,
metallic sulfide and pyrite roasting,
direct reduction of iron ore,
phthalic anhydride production,
* lime production, and
* nuclear processing (denitrification, reduction, hydrofluorination,
and fluorination of uranium; separation of plutonium from uranium).
Other applications, such as a plasma-heated fluid bed for phosphorus production,
an electrically heated bed for HCN production, coal gasification, and fluidized-
bed steam boilers, have also been proposed. Fluid beds range from single-stage
units to multi-stage devices, as exemplified by the various configurations of
preheaters and flash calciners shown in the Cement Industry Report (Volume X).
The fluidizing media can be gas (as in a suspension preheater described in the
cement report), or liquid (as described in the H-Oil ebullated bed). One of
the major advantages of a fluid bed is close temperature control and high
heat-transfer rates. Thus, when used as a preheater for solids rather than a
kiln or reverberatory furnace, one can accomplish combustion and heat transfer
at much lower "flame temperatures" and thus reduce NOx emissions. Where
limestone is part of the mixture being preheated (as in cement manufacture),
sulfur emissions are also kept under control.
48
-------
4. Heat Recovery
Recovery of waste heat from solids discharged from furnaces or kilns can
yield energy savings as exemplified by cement kilns (preheating of air) and
dry quenching of coke in the steel industry to generate steam or a hot gas
stream. As discussed under dry quenching in the steel industry report,
environmental problems anticipated are particulate emissions from hoppers and
hot valves as the solids are discharged. In general removing heat from solid
materials will entail controlling particulate and fugitive emissions.
5. NOy Emissions
All other things being equal, NOX emissions can be expected to increase
from many processes for a variety of reasons including:
fuel switching from gas or oil to coal; coal will contain some fixed
nitrogen and generally requires a greater amount of excess air;
both factors will normally lead to higher NOx emissions;
fuel firing with air preheating which leads to higher flame temper-
atures, leading to greater NOX emissions; and
fuel firing with oxygen-enriched air which generally leads to higher
flame temperatures and greater NOX emissions.
The environment, health, and ecological impacts of NOX need to be better
defined with respect to obtaining more quantitative knowledge for establishing
appropriate emission regulations. Control of NOX emission in an economic way
will demand new technology. Technology for abatement of NC^ emissions of the
200 ppm range is discussed in the Fertilizer Industry Report under nitric acid
manufacture.
6. Use of Oxygen
Oxygen use can be expected to increase in many industrial sectors as a
result of attempts to reduce energy use and costs. When used to enrich air
with fossil fuel firing, NOX concentrations can be expected to increase, but
total off-gas volume should decrease (assuming everything else remains
constant). NOx emissions can be reduced by limiting excess air, while still
ensuring complete combustion as discussed in the cement report. When oxygen
is used in place of fossil fuel (as in flash smelting of copper concentrates),
the flame temperature is not expected to increase and consequently there
should be little or no increase in NOX emissions. Several other direct firing
situations not studied in this project may benefit from air enrichment.
7. Electric Furnaces
With concerns about pollution control in fossil fuel-fired furnaces,
electric furnaces are being considered as an alternative in many industry
sectors. An example discussed in these studies is the electrically heated glass
furnace (Glass Industry Report, Volume IX). We are also aware that applications
of electric furnace technology is also being considered in other new
applications as in the iron and steel industry (direct reduction) and smelting
49
-------
of copper concentrates. Use of an electric furnace in place of a fossil
fuel-fired furnace reduces substantially the volume of gas and its particu-
late loading. Moreover, the S02 emissions can be many times eliminated by
replacing a high-sulfur fossil fuel by electric energy. While a glass plant
may mitigate its environmental problems with an electric furnace, the environ-
mental problem is passed back to the power plant, especially those using high-
sulfur coal. Considering typical power plant thermal efficiencies of about
30 to 40%, we found in the glass industry study that more fossil fuel is used
in the electric furnace when comparing a fossil fuel fired furnace against
the system consisting of a power plant with electric furnace. However, this
difference in fossil fuel requirements is small and total uncontrolled sulfur
emissions are little affected. However, we feel that such results cannot be
generalized to other industry sectors because furnace efficiencies depend on
a variety of factors, including size, design, operating temperatures, need
for water cooling to prevent refractory erosion, degree of endothermic versus
exothermic reactions during processing, and the like.
8. Use of Solvent
In two sectors (textiles, and pulp and paper) use of solvent processing
in place of aqueous processing is discussed. Solvent processing involves
some new sources of pollution (hydrocarbon or solvent emissions in gas
streams). Additionally we have discussed the application of solvent extraction
in the copper sector (use of liquid ion exchange resins) and manufacture of
clean phosphoric acid via the wet acid route.
-------
V. PROCESS RESEARCH AREAS
Potential areas of research identified in the process sections include
the following:
1. Aluminum
We suggest that consideration be given by the Government (not necessarily
EPA) to the possibility of undertaking or sponsoring materials research in the
field of producing titanium diboride cathodes suitable in quality to permit
long operating life in the Hall-Heroult cell environment. This development
would have a dramatic effect on energy savings in the aluminum industry; in
addition, there would be favorable environmental effects by reducing the
emissions from power plants per ton of aluminum produced as well as potentially
reducing CO emissions from alumina cells.
2. Ammonia
In assessing the pollution aspects of the coal alternative, it will be
necessary to measure and trace the materials of environmental interest in coal
gasification. This has been attempted and there are some preliminary data
available.
In design of recycle streams, such as the soot recycle to the gasifier,
it is apparent that certain trace elements may tend to build up since they may
not be able to escape. This could apply, for example, to volatile compounds
found in coal such as arsenic, lead, boron, and fluorine. More information
is needed to determine if this recycle buildup will be a problem.
3. Cement
We identified several areas in which additional data or information would
have been helpful. This forms the basis of our recommendations for additional
research into existing or future processes and industry practices in the U.S.
Portland cement industry. They are:
Develop and implement a commercial-scale test program to be imple-
mented on one or more flash calciner-equipped rotary kiln cement-
making facilities to characterize the gaseous and particulate
emissions. Of particular interest would be the emissions from a
flash calciner-equipped rotary kiln operating with a bypass of a
considerable amount of the combustion gases in order to eliminate
alkalies.
51
-------
Develop and implement a test program at a number of cement plants
with clinkering facilities employing long rotary kilns, suspension
preheaters, or flash calciners which burn coal as the fuel. Coal
of various sulfur levels should be tested to determine their effect
on operation and the level and nature of sulfur in the gas, dust,
and clinker. The benefits which derive from the physical and/or
chemical cleaning of coal to reduce pyritic sulfur levels in coal
for cement manufacturing could also be quantified.
Develop and implement a program to sample and analyze dust from
various kiln systems, especially those burning coal, in order to
correlate the trace elements, especially the heavy metals, in the
dust wastes, with the presence of those elements or constituents in
the raw materials and coal burned.
Develop and implement a program to analyze and study ways of using
waste kiln dust (for example, as a soil conditioner or plant nutrient,
or as the primafy or major raw material feed component to the
fluidized-bed cement process).
4. Chlor-alkali
Since the process changes in themselves are not expected to create new
environmental problems, but rather reduce the amount of pollution generated by
the chlor-alkali industry, we recommend that any research development or demon-
stration effort be oriented to accelerate and evaluate the introduction of the
newer, less polluting, energy-conserving technology.
5. Copper
The research we recommend in the following areas of the copper sector
would provide more information about these processes and might resolve the
problems preventing the adoption of these energy-conserving and envrionmentally
beneficial technologies.
a. Impurity Distribution
An understanding of impurity distributions is necessary for determining
emissions of trace metals and the need for pollution control or process change
to prevent these emissions. Such impurity distribution studies include:
The behavior of impurities in each process, their distribution in
gas, slag, matte, and metallic phases, and forms in which impurities
leave the process units (as particulates, slag, etc.);
In oxygen-enriched smelting, an examination and definition of the
changes in impurity distributions resulting from higher temperatures;
Impurity distributions in hydrometallurgy; and
Impurity forms in waste streams from pyrometallurgical and hydro-
metallurgical processes.
52
-------
b. Impurity Removal
Methods for removing impurities (e.g., Bi) from blister copper via
modified fire-refining procedures. If impurities can be removed from
copper, one-step smelting can be used. This would significantly
decrease fugitive 802 emissions from smelters;
Methods for removal of arsenic from elemental sulfur produced by SO
reduction;
Techniques for impurity removal from concentrates via pretreatment.
c. Feedstocks
Verifying the applicability of new smelting technology to impure
concentrates;
Verifying the applicability of new smelting technology to smelt
calcines from roasters.
d. Metal Recovery/Separation
Developing methods for separation and recovery of metals from flue
dust; in particular, the treatment of flue dust containing arsenic,
antimony, lead, and bismuth;
Methods for the recovery of precious and trace metals from hydro-
metallurgical residues;
Methods for the recovery of copper (also zinc and lead) from slag
flotation tailings;
Methods for reduction of copper in slag during pyro-
metallurgical slag cleaning, e.g., carbon reduction in a rotary
converter;
Conversion of ferric oxide sludge from hydrometallurgical processes
to a form suitable for use in other industries.
e. Miscellaneous
Developing high-temperature refractories for oxygen smelting;
Developing better process control techniques to reduce manpower
requirements, particularly in pyrometallurgy, which would reduce
hazards resulting from uncontrollable fugitive emissions.
6. Fertilizers
For nitric acid plants, it would be beneficial in terms of energy conserva-
tion to use processes other than catalytic reduction for NOX control.
Fortunately, such other processes require less capital and lower operating
costs. Thus, the industry will likely opt for such alternatives of free choice
53
-------
and will not require outside influence. In the process examined, control
appears adequate at steady state but not adequate during startup and shut-
down. Also, the NOX pollution control device is complex and may have to
be shut down, even though the basic plant continues to operate. Methods of
alleviating these problems are worthy of further study. Moreover, it would
be useful to study the applicability of these new processes to control NO
emissions from sources other than nitric acid plants.
For fertilizer drying, the most appropriate action is to disseminate
information on techniques for using bag filters in conjunction'with oil-
fired dryers.
7. Glass
A proven economically viable system to control glass furnace emissions of
SOX and particulates must be developed if cost-effective pollution control is
to be obtained. Such a system is required if any of the coal-related
processes is to be utilized.
The feasibility of a batch-preheating process modification needs to be
demonstrated to stimulate implementation of this technique for energy con-
servation and pollution reduction. (The technical and economic feasibility
of a preheat-agglomerate process modification is the subject of EPA's RFP
No. DU-75-A-291.)
Demonstration of the technical feasibility of producing quality glass
with economic furnace operation and life, using direct firing of pulverized
coal, would aid in conserving energy by utilizing the less critical form of
fuel with a minimum of intermediate steps and their cost in dollars and energy.
8. Iron and Steel
Five specific areas have been identified in this study where additional
research is needed:
a. The possibility of cyanide formation under the following circum-
stances should be investigated:
injection of nitrogen during external desulfurization, and
continuous recirculation of a CO-Nฃ mixture on incandescent
coke during dry quenching.
b. Quantitative measurements of fugitive and source emissions of carbon
monoxide with non-combustion BOP gas collection systems should prove
the acceptability of these hoods, including during the transition
periods at the beginning and end of the blow.'
c. A comparison of available equipment (lances, bells, etc.) for external
desulfurization should be made. At the same time, the exact nature
of the gaseous effluents should be determined according to the
exact type of reagent used.
54
-------
d. An increase In the quality of coke due to dry rather than wet
quenching has been reported in the Russian literature. Should
this be the case, a more efficient -operation of the blast furnace
would result and allow substantial savings, both in terms of coke
rate and furnace productivity. In order to substantiate this claim
using U.S. coals, a demonstration program is needed.
e. The chemistry of the rotary kiln (e.g., SL/RN, Krupp, Kawaski) is
still not well known. The pollution implications mentioned in this
study represent best engineering judgment and lack actual proof.
The composition of the off-gasefe and the leaching properties of the
coal, ash, and fine metallic discarded particles should receive the
attention of research organizations.
9. Olefins
The olefin industry can benefit from additional research on the removal of
sulfur from the cracked-gas stream. This stream contains hydrogen sulfide, some
carbonyl sulfides, and varying percentages of diolefins and other reactive com-
pounds which tend to foul the acid gas-removal system. As indicated in the
olefin report, this problem is now being handled by depropanizing the cracked-
gas stream -before acid gas is removed by scrubbing with diethanolamine. A
method of removing the sulfur compounds and acid gases from the cracked-gas
stream in the presence of diolefins (i.e., before the depropanizer) would be
of significant economic benefit to the olefin producers.
Naphtha and atmospheric gas oil feedstocks produce significant quantities
of byproduct pyrolysis fuel oil. If the feedstock material used in the
olefin plant has a sulfur content above a certain concentration, the byproduct
pyrolysis fuel oil has sulfur levels too high for its environmentally accept-
able use as a fuel without flue gas desulfurization. These byproduct fuel oils
also contain substantial amounts of unsaturates as well as other reactive
materials which tend to polymerize and form gums on handling. These present
problems when attempting to desulfurize the oils. It would be desirable to
develop an economically attractive process for desulfurizing the pyrolysis
fuel oil to a level where it would be environmentally acceptable as a fuel.
At present, most olefin producers limit the sulfur content of their feedstock
to circumvent this problem. As noted earlier, however, this limitation
severely restricts their choice of feedstocks.
10. Petroleum Refining
As a result of this assessment, two technology areas have been identified.
Through added research, each could increase energy conservation in terms of
form value availability. The first would have as an objective improving the
reliability and reducing the cost of flue gas desulfurization, especially in
the size range below 50 MW equivalent.
The second is concerned with developing rugged hydrocracking catalysts
which can withstand the poisons normally present in petroleum residues, or
alternatively an economic residual demetallization process. The objective in
this case would be to Increase space velocities (more activity) and yields.
Solvent de-asphalting of hydrocracker feedstocks is used for this purpose, but
55
-------
the energy requirement for solvent recovery is substantial. Technology
improvements in these areas could increase refinery yields of clean fuels
without sacrificing environmental quality.
11. Phosphorous
The wet process requires disposal of about four tons of gypsum per ton of
PjjC>5 product. The gypsum disposal problem can be managed to meet environmental
regulations through placement in settling basins for which precautions are
taken to prevent leaching into groundwaters or excessive surface run-off. The
gypsum wastes contain much of the fluorides which are a component of the
phosphate rock and which have been removed from gaseous streams by scrubbing.
The long-term containment of the large volumes of fluoride-containing gypsum
solids is a problem analogous to that facing the steam-electric generating
industry in its disposal of sludges from flue gas desulfurization and is an
area where research and development is needed to delineate the disposal methods
most acceptable to regulatory agencies. Many schemes have been proposed to
make use of the low-value byproduct gypsum, such as for wall board. Except in
unusual economic settings, most of these have not proven viable, but they do
represent a potential research area.
12. Pulp and Paper
Areas identified for further research demonstrations include the following:
The Rapson effluent-free kraft pulping process is the most signi-
ficant and imminent process industry change from the standpoint
of major energy and pollution implications. Therefore, EPA should
encourage its development by participation and, if necessary, pro-
vide support in bringing it to commercial fruition. Participation
would furnish EPA with environmental, energy, and cost data which
could then be made widely known to the industry.
* The alkaline-oxygen (A-0) process would apply to a much smaller
segment of the industry and thus lacks the potential impact of the
Rapson process in terms of reducing the industry's pollution
problems. On the other hand, the Rapson process would alleviate
only the water effluent problems, while the A-0 process would
alleviate both the air and water pollution problems presently
associated with the major alternative manufacturing method -
namely, kraft pulping and bleaching. We believe that EP'A should
participate in joint evaluation of this process.
The thermo-mechanical pulping (TMP) process is well established.
While it may be beneficial to obtain more precise analytical data
on its energy usage and pollution characteristics, all reports to
date indicate that (except for a 20% higher BOD load than with the
conventional RMP process) there is no significant difference
between the current and "new" technologies with regard to energy
usage or pollution.
-------
Hence, the IMP process does not warrant as much encouragement
and assistance in commercial evaluation as the two previously
listed process changes or the modification of the IMP process
(chemi-thermo-mechanical pulping - CTMP). Because CTMP offers
both significant advantages in increasing the available supply of
pulpwood and an inherently greater pollution problem than any of
the other mechanical pulping processes, an accurate evaluation of
its commercial potential appears appropriate when such data become
available.
The de-inking of old news for the manufacture of newsprint presents
an opportunity to save energy with no potential pollution problem.
Broader commercial application should be supported, because it
could reduce the amount of municipal solid waste.
Alternative drying techniques and displacement washing appear to
offer possibilities for significant energy savings with beneficial
effects on industry emissions. The potential energy savings appear
to be sufficiently attractive in paper drying to warrant further
pilot evaluation of the more promising techniques. Displacement
washing has reached commercial operation in a few installations, so
it does not require further development effort; nevertheless, its
impact upon energy and pollution considerations should be quantified
to verify the postulated benefits.
13. Textiles
a. Polyvinyl alcohol recovery has been shown to have economic and energy-
conserving advantages. So far it has only been demonstrated on
polyester/cotton sheeting. Its applicability to other products and
fibers should be demonstrated.
b. Energy saving is possible if the amount of water used for washing
can be reduced substantially. This would require an evaluation of
washing efficiency in the various types of washer used in the industry
and in the new units now available. Concurrently with this, a pro-
gram is required to demonstrate improved instrumentation and tech-
niques for monitoring washing in the various process steps and to
determine when adequate washing has been achieved.
c. Water reuse appears to be limited at present by the variety of
chemicals used in each process step. Development work is required to
minimize the amount of chemical used in each step and to make the
different chemicals more compatible with each other so that process-
ing steps may be combined and/or additional water recycled.
d. Recovery of chemicals other than FVA and caustic soda has not yet
achieved any major application, although work is in progress to
evaluate water and chemicals reuse in dyeing operations. Additional
methods for recovery of dyes, which are expensive and cause color
problems in waste treatment plants because of their refractory nature,
should be investigated.
,57
-------
e. A major obstacle to the demonstration of an all-solvent processing
system is the lack of acceptable techniques for solvent dyeing,
particularly of polyester and cotton/polyester blends. Pilot-scale
studies should be carried out to demonstrate the advantages and
limitations of the best processes described in the literature.
Similar work is also required to demonstrate the applicability of
solvent finishing systems.
f. It appears from the data available that solvent losses from an all-
solvent system are at present only marginally acceptable and may be
in excess of future occupational health or environmental regulations.
A study of an all-solvent system is required to define where and how
solvent losses occur and to develop better control technology for
solvent emissions. Otherwise, we believe this problem may represent
an obstacle to further development of solvent processing.
-------
VI. FUTURE REASSESSMENT OF PROCESS OPTIONS
As the various factors influencing the choice of process options change
with time, the evaluation system devised here should allow for easy reassess-
ment of the proposed process options. For example, capital investments and
operating costs were identified separately for the pollution control technology
and for the basic process operations. Similarly the unit consumption of
labor (man-hr/ton of product), power (kWh/ton), fuel oil (10& Btu/ton), etc.
was specified for both the base line and alternative technologies. Thus, as
the investment costs and operating cost factors (e.g., labor, 'fuel, and power)
change with time, these new values can be incorporated into the re-analysis of
the process options. Similarly should the impact of new or advanced pollution
control technology wish to be investigated, the investments, operating costs,
and energy consumption can easily be incorporated within the framework of a
reassessment study and compared with the base line technology as delineated in
this report. Furthermore we believe that the methodology used can be applied to
other industries and form the basis of a framework examining energy use and
pollutional consequences of new technology.
Since the analysis was performed on the basis of selecting a region of the
country and using applicable average cost factors within the industry, the
applicability of such new technology to other regions, sectors, or time frames
can also be easily accommodated by incorporating the appropriate new cost
factors, (e.g, labor rate, fuel cost, power cost, raw material cost, etc.).
Similarly, the impact of state or local environmental constraints can also be
examined where the differences from Federal regulations appear significant.
59
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA-600/7-76-034a
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE ENVIRONMENTAL CONSIDERATIONS OF
SELECTED ENERGY CONSERVING MANUFACTURING PROCESS
OPTIONS. Vol. I. Industry Summary Report
5. REPORT DATE
December 1976 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Arthur D. Little, Inc.
Acorn Park
Cambridge, Massachusetts 02140
10. PROGRAM ELEMENT NO.
EHE624B
11. CONTRACT/GRANT NO.
68-03-2198
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA-ORD
IB. SUPPLEMENTARY NOTES Vol. III-XV, EPA-600/7-76-034c through 034o, refer to studies of
specific industries as noted below; Vol. II, EPA-600/7-76-034b, is the Industry
Priority Report.
16. ABSTRACT
This study assesses the likelihood of new process technology and new practices being
introduced by energy intensive industries and explores the environmental impacts of
such changes.
Specifically, Vol. I presents the overall summation and identification of research
needs and areas of highest overall priority. Vol. III-XV deal with
the following 13 industries: iron and steel, petroleum refining, pulp and paper,
olefins, ammonia, aluminum, copper, textiles, cement, glass, chlor-alkali,
phosphorus and phosphoric acid, and fertilizers all in terms of relative economics
and environmental/energy consequences. Vol. II, prepared early in the study,
presents and describes the overview of the industries considered and presents the
methodology used to select industries.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Energy; Pollution; Industrial Wastes
Manufacturing Processes;
Energy Conservation
13B
8. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (ThisReport)
unclassified
20. SECURITY CLASS (Thispagef
unclassified
21. NO. OF PAGES
72
22. PRICE
EPA Farm 2220-1 (9-73)
60
------- |