PB-226 420
SOLID WASTE MANAGEMENT IN THE INDUSTRIAL CHEMICAL
INDUSTRY
RESEARCH CORP, OF NEW ENGLAND
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
1973
DISTRIBUTED BY:
Mnri
National Technical Information Service
U. S. DEPARTMENT OF COMMERCE
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SHEET
4. Title and Subtitle
FPA/S30/SW..3V
5. Report Date
1Q71
Solid waste management in the industrial chemical industry
6.
7. Author(s)
T V4*>Ku VJnlromh*
nH
U-
8. Performing Organization Kept.
No.
t. Performing Organization Name and Address
Research Corporation of New England
125 Silas Dean Highway
Hartford, Connecticut 06109
10. Project/Task/Work Unit No.
11. Contract 7«¥i!PNo.
CPE 69-5
12. Sponsoring Organization Name and Address
y. S. Environmental Protection Agency
'Office of Solid Waste Management Programs
Washington, D.C. 20460
13. Type of Report & Period
Covered
Final report
14.
15. Supplementary Notes
16. Abstracts This report presents the results of a national study to evaluate the
solid waste management practices of the industrial chemical industry, embodied by
Standard Industrial Classification (SIC) Number 281. Data and information on solid
waste management within the industry were obtained through literature review,
a questionnaire mailed to a selected group of Industrial chemical plants, and field
interviews with chemical plant personnel throughtout the country. Presented in the
report are the following information and data for the industrial chemical industry on
a national basis: (1) quantity and quality (character) of solid waste generated; (2)
universal parameters affecting solid waste generation; (3) current storage,
collection, and disposal practices; (4) annual operating.expenses; (5) analysis of >
the future trends in solid waste management within the industry and factors might
influence them.
17. Key Words and Document Analysis. 17o. Descriptors
Chemical industry, Industrial wastes, disposal, recycling, incineration, storage
transporation
17b. Identifiers/Open-Ended Terms
^Chemical waste, sanitary landfill, hazardous wastes
17e. COSATI Fie Id/Group 13B
18. Availability Statement
FORM NTIS-35 (REV. 3-72)
19. Security Class (This
Report)
UNCLASSIFIED
20. Security Class (This
Page
UNCL
ASS1F1ED
21. No. of Pages
22. Pfic,e *
USCOMM'DC I4952-P7Z
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This report has been reviewed by the U.S. Environmental
Protection Agency and approved for publication. Approval
does not signify that the contents necessarily reflect
the views and policies of the U.S. Environmental Protection
Agency, nor does mention of commerical products constitute
endorsement or recommendation for use by the U.S. Government.
An environmental protection publication (SW-33c) in the
solid waste management series
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PREFACE
This report on the solid waste management practices of the industrial
chemical industry was prepared by The Research Corporation of New England
(TRC) pursuant to Contract No. CPE 69-5, for the solid waste management
program of the U.S. Environmental Protection Agency. The statements,
findings, conclusions, recommendation, and data in this report are not
necessarily those of the Agency nor does mention of commerical products
imply endorsement by the U.S. Government.
The study was carried out by the Engineering Division of TRC, John E.
Yocom, Director. The Program Manager was Peter W. Kalika, and the Project
Engineer was J. Kirby Holcombe. Harold Jacobs, Wilmington, Delaware,
served as chemical waste consultant. Other participants for TRC were
Peter N. Formica, Associate Project Engineer; Scott G. Shanks, Senior
Research Scientist; and Charles R. Case, Programmer. Rodney L. Cummins,
and George L. Huffman, served as Project Officer for Federal solid Vaste
management programs.
Preceding page blank
iv
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ACKNOWLEDGMENTS
The authors wish to acknowledge the kind assistance of the many industry
representatives who gave so generously of their time during the formative
phases of the program. We are particularly grateful to the plant managers
or their designated representatives who welcomed the survey teams for many
hours of valuable consultation. Those who took the time to provide useful data
in the mail questionnaires are also gratefully acknowledged.
Special thanks are extended to George Best, Technical Director, and his
staff of the Manufacturing Chemists Association, whose suggestions and help
at several critical points in the program were invaluable. Rodney L. Cummins,
George Huffman, and George Garland of the Federal solid waste management program
also provided guidance at several stages of the study.
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TABLE OF CONTENTS
SECTION ONE: SUMMARY AND CONCLUSIONS 1
SECTION TWO: INTRODUCTION 11
SECTION THREE: THE INDUSTRIAL CHEMICAL INDUSTRY 15
Scope of the Industry 17
Evolution of the Industrial Chemical Industry in the United States 21
Geographic Distribution of the Industry 24
Characteristics of the Producing Companies 32
Role of the Industry in the Economy 37
Growth of the Industry 42
SECTION FOUR: SOLID WASTES OF THE INDUSTRIAL CHEMICAL INDUSTRY 47
Non-Process Wastes 49
Process Wastes 52
Process Waste Categorization 52
Process Waste Generation 56
Chemical Conversions 57
Unit Operations 59
Other Sources of Process Waste 62
Parameters Which Influence Solid Waste Generation 68
SECTION FIVE: INDUSTRIAL CHEMICALS GENERATING SOLID WASTES 71
Organic Chemicals 75
Coal Chemicals 75
Petrochemicals 79
Solid Waste Generation 83
Inorganic Chemicals 99
Solid Waste Generation-Alkalies and Chlorine Industry
(SIC #2812) 101
Solid Waste Generation-Industrial Gases (SIC #2813) Oxygen,
Nitrogen, Hydrogen, and Carbon Dioxide 106
Solid Waste Generation-Inorganic Pigments (SIC //2816) 111
Solid Waste Generation-Miscellaneous Inorganic Chemicals
(SIC #2819) 119
SECTION SIX: MANAGEMENT OF SOLID WASTES 139
Storage, Collection,and Transportation 141
Non-Process Waste 141
Process Wastes 142
Disposal 143
Non-Process Waste 143
Process Waste 145
Disposal Agencies 157
Development of the Management System 159
Non-Process Waste 159
Process Wastes 161
Recycling, Utilization, and Recovery of Prorp«»«< Wocst-eq 162
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SECTION SEVEN: SURVEY PROGRAM AND RESULTS 167
Purpose 169
Approach and Methodology 169
Development of Questionnaire Format and Survey Plan 169
Data Analysis 175
Distribution and Industry-Wide Coverage 177
Distribution 177
Industry-Wide Coverage 181
Discussion 182
Question 1-General Plant Information 182
Question 2-Non-Process Solid Waste Quantities and Activities 185
Question 3-Identification of Process Wastes 199
Question 4-Quantlties and Sources of Process Wastes 199
Question 5(a)-Storage and Disposal of Process Wastes 206
Question 5(b)-Cost of Disposal of Process Waste 212
Question 6-Physical and Chemical Characteristics of Process
Wastes 215
Question 7-Waste Generation Parameters 215
Question 8-Five Year Projection as to Waste Quantities,
Disposal Practices and Costs 215
Plant Visits 215
Municipal Questionnaire 219
PART A Municipal Refuse Disposal 220
PART B Non-Municipal Refuse Disposal 221
PART C Assessment of Chemical Plant Solid Waste 222
SECTION EIGHT: DISCUSSION OF FINDINGS, PROPOSED SOLUTIONS AND
RECOMMENDATIONS 225
Magnitude of the Solid Waste Disposal Problem 227
Solid Waste Management System Characteristics 235
Solutions to the Solid Waste Management Problems 239
Recommendations for Further Research and Development 244
APPENDIX
List of References 249
vii
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LIST OF TABLES
1 Summary of disposal costs and solid waste generation average
response to mail survey 4
2 Summary of management system charactristics mean responses
to mail survey (A) non-process waste 6
(B) process waste 7
3 Percent distribution of value of shipments for industries in
the chemicals and allied products group (1967) 19
4 The ten metropolitan areas with the highest chemical manufacturing
activity, chemical and allied products Industry-SIC #28 (1967) 29
5 The six states with the greatest number of industrial chemical
plants, 1967 30
6 The six states reporting the highest value added by manufacture
for industrial chemicals, 1967 31
7 The fifty largest companies in chemical sales in the United States 34-35
8 Percent of value of shipments accounted for by the largest
companies in the industrial chemical industry: 1967 and
earlier years 38
9 Size of chemical plants by numbers of employees (1967) (including
plants with less than 20 employees) 39
10 Economic position of the industrial chemical industry (1967) 41
11 Growth statistics for the industrial chemical industry, 1958-1967 43
12 Process waste categorization used in this study 54
13 Principal chemical conversions 58
14 Common unit operations 60
15 Value of shipments of organic chemicals (1967) 76
16 Principal coal chemicals 77
17 U.S. production of tar crudes, 1953 and 1967 78
18 Raw materials and basic petrochemicals produced from petroleum
and natural gas 80
19 Production and sales of crude products from petroleum and natural
and gas chemical conversion, 1967 81
20 Production of chlorine and alkalies-1963 and 1967 102
21 Production of industrial gases-1963 and 1967 109
22 Major inorganic pigments, SIC 2816, 1963 and 1967 114
23 Major inorganic chemicals, SIC 2819, production 1963 and 1967 120
24 Production of sodium phosphates-1967 130
25 Summary of questionnaire response distribution 173
26 Distribution of responses to mall questionnaire by plant size
and SIC classification 178
27 Distribution of responses to mail questionnaire by plant size
and geographical classifications 179
28 Mail survey coverage of industrial chemical plants by region 180
29 Summary of quantities of sludge process wastes (tons per year) 200
30 Summary of quantities of filter residue process wastes (tons
per year) 202
31 Summary of quantities of tar process wastes (tons per year) 203
32 Comparison of process waste quantities as determined by the
mail and plant visit surveys 205
33 Summary of mail survey responses regarding process waste storage 207
34 Summary of mall survey responses regarding process waste transport 208
viii
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35 Summary of mall survey responses regarding process waste
disopsal
36 Summary of mail survey responses regarding process waste
disposal costs
37 Summary of mail survey responses regarding process waste
characteristics
38 Summary of mall survey responses regarding process waste
generation parameters
39 Summary of mall survey response regarding process
quantities in 1975
40 Comparison of solid waste management characteristics by region
.^A ^.Y.aB5£8e8. °* centralized^ industrial waste disposal facilities
42 Industrial chemical manufacture SIC #281 by State and region
210
213
216
217
218
234
245_
254
ix
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LIST OF FIGURES
1 U.S. Bureau of Census Regions (1969) 25
2 Areas of concentration of industrial chemical manufacture, 1967 26
3 Total U.S. population, urban and rural, by states (1960) 28
4 Manufacture of industrial chemicals by SIC subgroup for selected
regions, 1967 33
5 Solid waste generation from a typical chemical plant 50
6 Interrelationship of chemicals from natural gas, petroleum cuts,
and coal 74
7 Schematic diagram for manufacture of toluene, benzene, and
xylene from petroleum by hydroforming 82
8 Schematic diagram for manufacture of toluene, benzene, and
xylene from coal gas and tar light oil by acid washing 84
9 Schematic diagram for manufacture of phenol by the benzenesulfonate
process 86
10 Schematic diagram for manufacture of phenol from toluene 88
11 Schematic diagram for manufacture of phthalic anhydride from
ortho-xylene 90
12 'Schematic diagram for manufacture of nitrobenzene from benzene
and nitric acid 92
13 Schematic diagram for manufacture of aniline from nitrobenzene by
reduction 93
14 Schematic diagram for manufacture of toluene diisocyanate from
toluene and phosgene 94
15 Schematic diagram for manufacture of ethyl chloride from ethylene
and hydrogen chloride 96
16 Schematic diagram for manufacture of citric acid from molasses by
fermentation 98
17 The alkalies and chlorine industry 100
18 Schematic diagram for manufacture of soda ash by the Solvay Process 104
19 Major production processes for industrial gases 108
20 Schematic diagram for manufacture of acetylene from paraffin
hydrocarbons by pyrolysis. (Wulff Process) 112
21 Schematic diagram of manufacture of acetylene from natural gas
by partial oxidation. (Sachsse Process) 113
22 Schematic diagram for manufacture of titanium dioxide from
ilmenlte 116
23 Schematic diagram for manufacture of titanium dioxide from rutile
by chlorination and oxidation 118
24 Schematic diagram for manufacture of alumina from bauxite by the
Bayer Process 122
25 Schematic diagram for manufacture of phosphoric acid from phosphate
rock by the wet process 128
26 Schematic diagram for manufacture of phosphoric acid and phosphorus
from phosphate rock by blast furnace 129
27 Schematic diagram for manufacture of disodium phosphate and
trisodlum phosphate from phosphoric acid and sodium carbonate 132
28 Schematic diagram for manufacture of Glauber's salt from salt
and sulfurlc acid 136
29 Schematic diagram for manufacture of hydrofluoric acid from
fluorspar and sulfuric acid 138
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30 Schematic diagram of combined process and non-process waste
incinerator 146
31 Schematic diagrams of tar burners 148
32 Schematic diagram of open pit Incinerator 150
33 Schematic diagram of chemical plant non-process solid waste
disposal alternatives 158
34 Schematic diagram of chemical plant process solid waste
disposal alternatives 160
35 U.S. Public Health Service Regional Designations, 1969 172
36 Mail survey results for mean quantities of non-process waste
distributed by plant-size classification 186
37 Mail survey results for mean quantities of non-process waste
distributed by SIC classification 188
38 Mail survey results for mean quantities of non-process waste
distributed by regional classification 189
39 Mail survey results for mean disposal costs of non-process waste
distributed by plant-size classifications 194
40 Mail survey results for mean disposal costs of non-process waste
distributed by SIC classification 195
41 Mail survey results for mean disposal costs of non-process waste
distributed by regional classification 196
xi
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SOLID WASTE MANAGEMENT
IN THE INDUSTRIAL CHEMICAL INDUSTRY
SECTION ONE: SUMMARY AND CONCLUSIONS
With the passage In October 1965 of the Solid Waste Disposal Act, the
Federal Government accepted the responsibility to assist in the improvement
of solid waste management practices on a national basis. Upon assuming this
responsibility, the Federal solid waste management program was confronted with
a lack of comprehensive information with which to define solid waste problems
of municipalities and industries in specific terms. A series of industrial
studies was instituted by the program in a number of areas, including the
packaging industry, the plastics industry, the drug industry, and others, to
define industrial solid waste management practices. As one of the series,
this study is directed entirely at the industrial chemical industry. The
scope of the industrial chemical industry was defined as Bureau of the Census
Standard Industrial Classification (SIC) No. 281, and includes all plants
producing industrial organic and inorganic chemicals in commercial quantities.
The objective of the study was to evaluate the solid waste management
practices of the industrial chemical industry. Information and data were
collected for the following items on a national basis: (1) total number of
industrial plants, employment, value added by manufacture, and quantities and
types of products produced; (2) past development and production patterns within
the Industry, with an indication of present trends, new technology and future
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development; (3) flow diagrams for the basic production processes, showing
points of solid waste generation; (4) location of industries with identification
of production centers in the country; (5) the quantity (weight) and quality
(character) of solid waste generated; (6) universal parameters that affect solid
waste generation; (7) current storage, collection, treatment, and disposal of
solid waste for the industry; (8) analysis of the future trends of solid waste
management within the Industry and factors which might influence them.
In 1967, the industrial chemical industry consisted of 2,030 plants, and
employed 252,000 people. Its value of shipments in 1967 was $14,100 million.
The economic importance of this industry to the Nation is emphasized by the
fact that it contributes one-third of both value of shipments and value added
by manufacture to the chemical and allied products industry, which in turn
represents nine percent of value added for all manufacturing industry.
Growth in value added by manufacture for the industry was 83 percent
during the 1958-to-1967 period. This figure was not as large as the chemicals
and allied products major group (90 percent), and only slight greater than
all manufacturing industry (80 percent). Growth of different chemicals has
been varied within the industry, however, with some classes of chemicals growing
at rates greater than 100 percent over the same period. Recently, growth has
been more rapid and value of shipments is predicted to approach $17 billion
in 1970.
The middle-Atlantic and north-central regions of the country are the
areas of greatest industrial chemical manufacturing activity, on the basis of
value added by manufacture. An analysis by state revealed that Texas and New
Jersey have the greatest concentration of industrial chemical manufacture,
containing over 21 percent of the chemical manufacturing plants in the United
States. This figure represents 30 percent of the value added by manufacture
of the industry.
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Solid waste from industrial chemical plants was categorized as process
wastes which are those generated directly from chemical processes and non-process
wastes. An average of 690 tons per year per plant of non-process waste was
reported by those plants responding to the mail questionnaire, as shown on
Table 1. The average process waste quantities were found to be considerably
greater, at approximately 33,000 tons per year per plant.
Process wastes were categorized as follows: sludges, filter residues,
tars, flyash, off-quality product, and other. These process wastes were found
to be extremely variable in quantities generated, with some large responses
considerably influencing the average value. The largest quantities of process
wastes reported were filter residues and sludges, with average waste quantities
of 43,000 and 25,000 tons per year, respectively for those plants reporting
these waste categories. Other average quantities reported were tars at 600
tons per year, flyesh at 22,000 tons per year, off-quality product at 960 tons
per year, and other process wastes at 990 tons per year.
The 28 in-depth plant visits confirmed, in most cases, the results obtained
from the mail survey.
The survey showed that non-process waste generation is generally a function
of plant size, in terms of employees; i.e., the larger the plant, the more
waste generated. The generation of process waste, however, is not necessarily
related to plant size, but is probably more closely related to the types and
quantities of industrial chemicals produced and the processes employed. The
quantity of solid waste generated by a particular chemical production process
was found to be Influenced by a number of parameters related to processing raw
materials and operations. The five which seemed to be the most prominent were:
(1) total production volume; (2) purity of raw materials; (3) efficiency of
reaction; (4) general maintenance and (5) process control.
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TABLE 1
SUMMARY OF DISPOSAL COSTS AND SOLID WASTE GENERATION
AVERAGE RESPONSE TO MAIL SURVEY
Disposal cost Average generation Total yearly
Solid waste type (weighted $/t) (tons) disposal costs
Non-process waste $14.10 690
Process waste 4.10 33,000
$ 9,730
135,000
Total (weighted) 4.30 33,700 145,000
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The survey indicated that industrial chemical plants expect future solid
waste generation to increase significantly. Present generation of sludges
and filter residues is expected to Increase by 50 percent by 1975, due mainly
to increased production rates. New sources of process waste generation, such
as additional chemical production processes, will also add to the increase in
plant process waste generation. Other factors which may influence future solid
waste quantities are air and water pollution regulations and the success of
chemical salvage operations.
Management of solid wastes at industrial chemical plants involves large
annual operating -expenditures. The average cost of disposal (including
collection) of non-process combustible materials, as indicated by the mail
survey results, was $32.80 per ton. Small plants exhibited the highest per
ton cost for combustibles. The corresponding cost for non-process noncumbustible
waste was $23.80 per ton, with extra large plants incurring the highest per ton
cost. The weighted average cost for all non-process waste was $14.10 per ton.
Disposal costs for process wastes were found to be highly variable from
plant to plant. The overall average for process waste was $44.70 per ton,
computed as the average of each plant's dollar per ton cost. The weighted average
cost was considerably less, at $4.10 per ton. The effect of quantity of solid
waste on unit disposal cost is dramatically illustrated by the substantial
difference between these figures. Using the weighted average disposal cost
and the average waste quantities for all wastes, the average annual cost for
management of solid wastes at typical industrial chemical plants is $145,000.
\
The average responses to the mall survey for management system
characteristics are summarized on Table 2. The source areas for non-process
combustible and noncumbustible waste are fairly evenly divided between plant
production and non-production areas. The majority of salvageable metal Is
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TABLE 2
SUMMARY OF MANAGEMENT SYSTEM CHARACTERISTICS
MEAN RESPONSES TO MAIL SURVEY*
(A) NON-PROCESS WASTE
Was tea
Source
area
Storage
Percent
production
percent non-
production
Bulk
Containers
Compaction
Casual
Multiple
Other
Storage period, days
Ultimate
disposal
site
Ultimate
disposal
method
Agency for
Disposition
Percent
Landfill
Incineration
Other (open burning,
dump, etc.)
off-site disposal
Combustibles (%) (paper,
wood, bags, etc.)
49
51
55
4
22
16
3
10
on-site off-site
35 64
43
25
dump 13 other 14
open 5
govt. 52 private 44
capt. 2 mult. 2
Noncombustibles (%)
(glass, drums, etc.) Salvageable metal (%)
58 67
42 33
52 35
3 0
27 51
11 10
7 4
22 119
on-site off-site on-site off-site
33 66 -
73
0
dump 13
other 14
govt. 47 Private 50
capt. 2 mult. 1
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TABLE 2 (continued)
SUMMARY OF MANAGEMENT SYSTEM CHARACTERISTICS
MEAN RESPONSES TO MAIL SURVEY*
(B) PROCESS WASTE
Container 59
Storage Casual 11
(percent)
Ponds 14
No storage 16
Storage period (days) 74
Truck 76
Transport Pipeline 22
method
(percent) Barge 1_
Rail
On-site 39
Disposal
(percent) Off-site 61
Captive 8
Nature
off-site Private
disposal contract 70
(percent)
Government 22
Land disposal 72
Disposal
method Incineration 8
(percent)
Lagoon 10
Other 10
Note:
Government (govt.)-Sites owned by federal, state and local government
Captive (capt.)-Sites owned by the chemical plant.
Private-Sites owned by a private individual (waste disposal contractor).
Multiple (mult.)-Use of more than one type of site as listed above.
^Percentages shown relate to the proportion of those plants responding
to the particular questions.
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generated in production areas. Over 50 percent of the non-process waste is
stored in containers, and very little use of compaction was reported. Storage
periods for combustible waste were well over one week, and for noncumbustible,
over three weeks. Sixty percent or more of nonprocess waste was disposed of
off-site, and approximately 50 percent is disposed of at government facilities.
Landfill is the dominant disposal method, but 13 percent reported dumps and 5
percent burned combustibles in the open.
Process waste management characteristics are somewhat similar to those
of non-process waste with over 50 percent stored in containers and 56 percent
disposed of off-site, while land disposal is the dominant disposal method for
each. The mean storage period for all process waste, however, is considerably
longer at well over two months, and only 30 percent of the process waste disposed
of off-site is at government facilities. It is significant to note that about
half of the process wastes reported were disposed of by parties other than the
plants themselves.
Efforts to control the quantity of solid waste produced by industrial
chemical plants should be directed first towards reduction of solid waste
generation at the source, i.e., the basic process operations. Once a solid
waste is generated, however, two alternatives to its disposition exist—
disposal or salvage. The disposal methods used for process wastes are essentially
the same as those utilized for municipal refuse, i.e., landfill and incineration.
New, more effective methods must be developed for disposal of these process
wastes emphasizing abatement of environmental pollution, reduction of the
waste to the smallest possible volume, and recovery of valuable constituents
within the waste.
It is more desirable to salvage the waste through recycling, recovery,
and utilization. The variable characteristics of process waste, however, dictate
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that salvage possibilities and procedures be developed or adopted by each
plant to suit its own individual wastes. Prospects for solid waste salvage
will increase if private contract disposal companies are successful in
obtaining large process waste quantities amenable to centralized reprocessing.
Observers visited a number of plants with exceptionally well-designed
and controlled disposal facilities; the potential for pollution was minimized
at these plants. The majority of plant disposal operations, however, were
potentially capable of polluting either air, water, or land. This study
recommends that guidelines for the disposal of chemical process waste be
developed, detailing the best procedures for disposal of sludges, filter
residues, tars, etc. by means of the common currently available disposal
methods: landfill, incineration, lagooning, etc. These guidelines would
immediately assist this industry in improving its disposal practices to
minimize adverse environmental effects.
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SECTION TWO: INTRODUCTION
This document Is the final report on a national industrial solid waste
management study o$ the industrial chemical industry conducted for the solid
waste management program of the U.S. Environmental Protection Agency under
contract No. CPE 69-5. The study program was initiated by The Travelers
Research Corporation and has been completed by The Research Corporation of
New England (TRC), formerly the Environmental Quality and Waste Management
Department of The Travelers Research Corporation.
The program's objective was to study and evaluate solid waste management
practices in the industrial chemical industry by surveying manufacturing
processes dealing with the manufacture of industrial chemicals. For purposes
of establishing program scope, the study was to be limited to Standard
Industrial Classification (SIC) 281.
The program was conducted as one of a series sponsored by the Federal
solid waste management program to obtain basic information regarding the
nature and dimensions of the solid waste problem in a number of industrial
areas. Industrial solid wastes are, by definition, any discarded solid
materials resulting from an industrial operation or coming from an industrial
establishment. They include processing waste, general plant waste, packaging
and shipping waste, office waste, and cafeteria waste.
The study was carried out primarily by means o'f direct contact with
industrial chemical Industry manufacturing establishments. This was accomplished
by a mail survey and by plant visits. Simultaneously available information
on industry statistics, technology, future plans, and waste disposal practice
were obtained from a number of traditional sources and analyzed. The mail
survey responses were programmed for computer analysis, and the plant visit
data were used both for confirmation of the mail results and for detailed
Preceding page blank
11
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insight into industry solid waste practices.
The study was initiated in May 1969 with a pilot plant visit program.
During this first step, selected industry representatives and plants assisted
in the development of the questionnaire format for the mail survey. During
these early interviews, it became apparent that the scope of the study had to
be limited. The industry representatives were quite firm in their position
that data on company or plant fiscal matters and production quantities would
not be made available. It was also apparent that responses to questionnaires
on various environmental matters had become a very time-consuming task for
many plants, and that an overly comprehensive questionnaire would very likely
be ignored. It was strongly suggested that the questionnaires be restricted
to queries regarding solid wastes and that they be kept reasonably brief.
A further and more significant finding of the pilot study was the need
to restrict the level of detail applied to the identification of specific
chemical solid wastes. The complexity of the industry in its many manufacturing
processes and its myriad products and wastes made it apparent that the
identification of individual wastes would be out of the question except in
Isolated instances. In many cases the Industry itself does not know the
specific chemical identification of a waste stream, since many are mixtures
of residues from several processes. Thus the most pertinent accomplishment
of the pilot study portion of the program was the adoption of several general
process waste categories to be used in the balance of the program. This step
and the formulation of the questionnaire represented a compromise which held
the promise of maximizing the industry's response to the program.
The questionnaire formats were submitted for Budget Bureau approvals in
September 1969. The approvals were received in January 1970, and the program
was resumed on February 1, 1970. Mail questionnaires were distributed on
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March 1, 1970, followed by the completion of the plant visits in August 1970.
Response to both was slower than expected. Many larger corporations adopted
a comprehensive review and approval procedure, delaying their plants' responses
for several months. Arrangements for plant visits were also difficult to
accomplish, not necessarily because of resistance on the part of the plants,
but simply because of scheduling problems. The overall response provided a
return of 12 percent in usable replies, and this was considered adequate for
the realization of the objectives of the study. Response tabulation and data
analysis were carried out through November 1970, and report preparation through
January 1971.
The report consists of eight sections and several appendices. Section
Three describes the nature of the industrial chemical industry and its position
in the national economy. This discussion was included as a necessary part of
the contract to provide those unfamiliar with the industry with a basis for
understanding the nature and scope of the industry's solid waste problems.
Section Four defines the solid waste categories of the industry and their
sources.
Section Five reviews a number of chemical processes in detail and traces
their potential for generation of solid wastes. Solid waste generation in
this industry is fundamental to the chemical manufacturing process. In the
production of chemicals, generation of solid waste varies both in quantity and
composition with the manufacturing process used. It can also vary within the
same manufacturing process due to such factors as the raw material used,
temperature conditions, design of equipment, and choice of catalyst. In order
to adequately describe this variability to those unfamiliar with chemical
engineering, it was deemed necessary to provide a discussion of the nature of
chemical manufacture.
13
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Those people far.illiar with the industrial chemical industry will be
mostly interested in Sections Six, Seven and Eight. Section Six presents an
analysis of current solid waste management practices in the industrial chemical
industry, while Section Seven presents the results of the survey program both
from mailed questionnaires and plant visits. Section Eight provides a
discussion of the program findings.
14
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SECTION THREE: THE INDUSTRIAL CHEMICAL INDUSTRY
Scope of the Industry 17
Evolution of the Industrial Chemical Industry in the United States 21
Geographic Distribution of the Industry 24
Characteristics of tiie Producing Companies 32
Role of the Industry in the Economy 37
Growth of the Industry 42
Figures
1 U.S. Bureau of Census Regions (1969) 25
2 Areas of concentration of industrial chemical manufacture,
1967 26
3 Total U.S. population, urban and rural, by states (1960) 28
4 Manufacture of industrial chemicals by SIC subgroup for
selected regions 1967 33
Tables
3 Percent distribution of value of shipments for industries
in the chemicals and allied products group (1967) 19
4 The ten metropolitan areas with the highest chemical
manufacturing activity, chemical and allied products
industry-SIC#28 (1967) 29
5 The six states with the greatest number of industrial
chemical plants, 1967 30
6 The six states reporting the highest value added by
manufacture for industrial chemicals, 1967 31
7 The fifty largest companies in chemical sales in the United
States 34-35
8 Percent of value of shipments accounted for by the largest
companies in the industrial chemical Industry: 1967
and earlier years 38
9 Size of chemical plants by numbers of employees (1967)
(inducing plants with less than 20 employees) 39
10 Economic position of the industrial chemical Industry (1967) 41
11 Growth statistics for the industrial chemical industry,
1958-1967 43
15
-------
SECTION THREE: THE INDUSTRIAL CHEMICAL INDUSTRY
Scope of the Industry
The industrial chemical industry, which manufactures a wide variety
of chemicals and chemical products, is one of a number of sub-industries
comprising the broad chemical industry. The parent chemical industry includes
all those industries whose manufacturing operations are composed of processes
which are predominantly chemical.
In its industrial classification, the Bureau of the Census has grouped
the entire chemical industry into one classification called Chemicals and
Allied Products. This group comprises all those establishments producing
chemicals and those producing finished chemical products. The industry,
Standard Industrial Classification (SIC) #28, is defined by the Bureau as
follows:
This major group includes establishments producing basic
chemicals, and establishments manufacturing products by
predominantly chemical processes. Establishments classified
in this major group manufacture three general classes of
products: (1) basic chemicals such as acids, alkalies,
salts, and organic chemicals; (2) chemical products to be
used in further manufacture such as synthetic fibers,
plastics materials, dry colors and pigments; (3) finished
chemical products to be used for ultimate consumption
such as drugs, cosmetics, and soaps; or to be used as
materials or supplies in other industries such as paints,
fertilizers, and explosives. The mining of natural rock
salt is classified in mining industries. Establishments
primarily engaged in manufacturing nonferrous metals and
high percentage ferroalloys are classified in Major Group
33; silicon carbide in Major Group 32; baking powder,
other leavening compounds, and starches in Major Group 20;
and embalming fluids and artists' colors in Major Group 39.
Establishments primarily engaged in packaging, repackaging
and bottling of purchased chemical products, but not engaged
in manufacturing chemicals and allied products, are classified
in trade industries.
Appearing under the broad heading of chemicals and allied products, SIC #28,
are eight major categories as follows:
Preceding page blank 17
-------
SIC No. Major Categories
281 Industrial inorganic and organic chemicals
282 Plastics materials and synthetic resins, synthetic
rubber, synthetic and other man-made fibers,
except glass
283 Drugs
284 Soap, detergents, and cleaning preparations, perfumes,
cosmetics and toilet preparations
285 Paints, varnishes, lacquers, enamels, and allied
products
286 Sum and wood chemicals
287 Agricultural chemicals
289 Miscellaneous chemical products
This study is concerned with solid waste generated by industries
producing chemicals within the first category only, SIC #281, Industrial
Inorganic and Organic Chemicals, sometimes called Basic Chemicals, or
Industrial Chemicals. Organic chemicals have been defined as those compounds
containing carbon atoms in a form similar to those in plant and animal matter,
and conversely, inorganic chemicals are defined as compounds usually not
containing carbon (except compounds such as carbides and carbonates) but
derived from atmospheric gases, minerals, water, and other matter that was
never, of itself, a part of living organisms.
Industrial chemicals, SIC #281, is the largest of the eight subgroups
under SIC #28 Chemicals and Allied Products. In 1967 its value of shipments
amounted to over $14 billion, or just over 33 percent of the total value of
shipments for the Chemical and Allied Products industry. Table 3 shows the
relationship, in terms of value of shipments, between the industrial chemical
industry and the other subgroups in SIC #28. The basic chemicals necessary
to produce the chemical products included in the other subgroups are supplied
primarily by this industry.
The industrial chemical Industry, SIC #281, is composed of basic chemical
manufactures and does not include producers of allied chemical products.
Processes and plants producing the following material are not Included in SIC #281
-------
TABLE 3
PERCENT DISTRIBUTION OF VALUE OF SHIPMENTS
FOR INDUSTRIES IN THE CHEMICALS AND ALLIED PRODUCTS GROUP (1967)*
Value of shipments
SIC No.
281
282
283
284
285
286
287
289
Chemical group
Industrial inorganic and organic chemicals
Fibers, plastics, rubber
Drugs
Cleaning and toilet goods
Paints and varnishes
Gum, wood chemicals
Agricultural chemicals
Miscellaneous chemical products
Total
Millions of dollars
14,100
7,430
5,260
6,450
2,920
224
2,690
3,110
42,200
% Total
33.0
18.0
13.0
15.0
7.0
0.0
6.5
7.5
100.0
*From Reference #67.
19
-------
and are therefore excluded from this study: pesticides; medicinal chemicals
and medicines; wood distillation products; naval stores; cosmetics; plastics
such as polyvinyl chloride, polyethylene, polypropylene, and polyurethanes;
synthetic rubber; rayon; and other synthetic fibers such as nylon, polyesters,
acrylics and modacrylics, vinyls, etc.; paints; and drugs. In addition, the
following basic "raw material" industries that have been included in other
SIC classifications are not included in this study, namely: industries
manufacturing coal tar crudes in chemical recovery ovens (coking plants);
petroleum refineries; and plants primarily engaged in mining, milling, or
otherwise preparing naturally occurring ores and other similar materials.
To further classify the industrial chemical industry, the Bureau of the
Census has defined six subcategories within SIC #281 as follows:
SIC #2812: Establishments primarily engaged in manufacturing alkalies
and chlorine;
SIC #2813: Manufacture of industrial gases, Including acetylene, carbon
dioxide, hydrogen, nitrogen, etc.;
SIC #2815: Manufacture of cyclic intermediates, dyes, organic pigments,
and cyclic crudes. This subcategory includes lakes and toners; coal tars;
derivatives of benzene; toluene; and other cyclic chemical products of medium
and heavy oil, such as creosote oil, naphthalene and anthracene;
SIC #2816: Manufacture of inorganic pigments, including iron colors,
lead pigments, titanium pigments, and zinc oxide pigments;
SIC #2818: Manufacture of organic chemicals not Included in the previous
categories. This subcategory includes a wide variety of chemicals, solvents,
polyhydric alcohols, synthetic perfume and flavoring materials, rubber processing
chemicals, plasticizers, and synthetic tanning agents;
SIC #2819: Manufacture of inorganic chemicals not included in the previous
-------
categoeries, such as inorganic salts of sodium, potassium, aluminum, calcium,
etc.; inorganic compounds such as alums and ammonia compounds, rare earth metal
salts and elemental bromine, fluorine and alkali metals.
The industries included in these six subcategories are the basis of
this solid waste study. A more detailed list of the chemicals whose manufacture
is included in these subcategories will be found in the appendix Table 43.
There is often a marked overlap of manufactured chemicals, allied products,
and even nonchemical products in many chemical plants. Two prominent examples
of this overlap which occur in many plants are in plastics and synthetic fibers.
All of the basic chemicals used to produce these two products are included in
SIC #281, including phenol, plasticizers, and styrene for plastics; adiplc
acid, sebacic acid, and other acids for nylon; acrylonitrile for acrylics;
and others, but the plastics and fibers themselves are not included. Every
effort was made when visiting plants and analyzing mail questionnaire returns
to include only solid wastes associated with industrial chemical, SIC #281,
production.
Evolution of the Industrial Chemical Industry in the United States
During the last two centuries, the United States has progressed from a
country with little or no chemical production to a world leader in chemical
technology and sales. The availability of raw materials, both domestic and
Imported, the availability of power, and the demand for chemical products
have helped to shape the types and quantities of chemicals produced, the
processes used, and the location of chemical centers.
The use of chemical products began very early in young America. The
early colonists produced simple tanning, bleaching, and dyeing products. As
early as 1635, industry in Boston was producing saltpeter for gunpowder and
21
-------
alum for tanning.
The colonists established an export trade with England in the early
18th century for potash and naval stores. One of the causes for America's
drive for independence was Parliament's forced duties on white lead and other
chemical products.
It was the 19th century, however, that saw the real beginnings and growth
of chemical production. Chemical plants sought to locate themselves in those
geographic areas where natural raw materials for chemical production existed.
Thus, as the industry grew, those areas rich in these materials became the
centers for chemical production.
In 1802 Wilmington, Delaware, was selected for the site of a powder mill
by a French pupil of the chemist Lavoisier. This student was Euthere Irenee
du Pont who founded the company which now bears his name. Philadelphia was
the site of the first sulfuric acid plant built in 1793. This first plant
used the batch lead chamber process, but by 1829, the first continuous
production operation was installed. By 1829, Philadelphia had developed into
a chemical center with merchants producing white lead, acetic acid, linseed
oil, and paste pigments.
St. Louis industrialists began production of red lead in 1811, and in
the same year, the gold rush brought acid manufacturing to the West Coast
to meet gold refining needs. In 1850 the agricultural chemical industry was
born, and sulfuric acid plants moved south to the source of phosphate rock.
Salt and lime deposits at Syracuse, New York, were exploited in 1884 when an
ammonia-soda plant using the Solvay process was built. One soda ash plant
built over Michigan salt deposits and another built over salt domes in southwest
Virginia in 1895 helped to bolster production of alkalies which were previously
imported from Great Britain. In 1896 the first cholerine process was established
-------
by Herbert H. Dow, and bromine was extracted from Michigan brine deposits.
At the same time that the chemical industry was utilizing Michigan's brine
deposits, Niagara Falls, New York was developing into a chemical center,
primarily due to the availability of cheap hydroelectric power. Niagara Falls
became a center for production of chlorine, caustic soda, sodium and potassium
chlorates, yellow phosphorus, and calcium carbide.
At the beignning of the present century, chemical production was primarily
inorganic. Allied products, such as patent medicines, paints and varnishes,
and soap and fertilizers were the largest commodities. The primary industrial
chemicals at this tine were soda ash, sulfuric acid, caustic soda, nitric acid,
and glycerin.
Department of the organic chemical industry occurred during World War
I. The German supply of organic chemicals upon which the U.S. depended were
cut off, and we had to develop our own production capabilities. A nitric acid
plant using cyanamid-derived ammonia was built in 1916 at Warners, New Jersey,
to help manufacture the large quantities of explosives required during World
War I. In 1907 at Joliet, Illinois, Dr. Heinrich Koppers developed an apparatus
and process for economical recovery of chemicals from coal in the coke-making
process, and the U.S. organic chemical industry was underway.
After World War I, growth in the chemical industry progressed rapidly
as America moved toward the 20th century technical leadership which required
greater and greater quantities of chemicals. Early in this period the industry
also recognized the importance of research to the development of new chemicals.
This awareness has led to the immense quantities and varieties of chemicals
presently produced. Today the American chemical industry produces nearly 50
percent of the free world's output of chemicals. (3,13)
23
-------
Geographic Distribution of the Industry
The industrial chemical industry is concentrated in certain areas of the
country rather than randomly distributed throughout the nation. These areas
coincide with those of high population concentration and other industrial and
commercial activity, along with easy access to raw materials necessary for
chemical manufacture. In addition, the industry requires a source of inexpensive
power, a good transportation system, and people for a work force.
Various sections of the country were evaluated to determine areas of intensive
industrial chemical manufacture. Regional evaluation was based on the U.S. Bureau
of the Census regions (Figure 1). Concentration of industrial chemical manufacture
was evaluated from "value added by manufacture" as reported by the Bureau of the
Census. Value added by manufacture is obtained by subtracting the total cost of
materials (including supplies, fuel, electric energy, cost of re-sales, and
miscellaneous receipts) from the value of shipments (including re-sales) and other
receipts, and adjusting the resulting amount by the net change in finished products
and work-in-process inventories between the beginning and end of the year. This
method is considered to be the best value measure for comparing the relative
economic importance of manufacturing among industries and geographic areas.
The west-south-central, middle-Atlantic and north-central regions of the
country are the areas of greatest industrial chemical manufacturing (Figure 2).
These regions also contain the majority of those metropolitan areas with over $100
million in value added by manufacture for chemicals and allied products in 1967.
The west-south-central region includes the cities of Dallas and Houston, the
middle-Atlantic region contains the cities of New York (and surrounding New Jersey
metropolitan areas), Philadelphia, Wilmington, Buffalo, Niagara Falls, and
Pittsburgh, while tha north-central region includes Chicago, Detroit, Cleveland,
Cincinnati and Indianapolis.
-------
,—f\
North
Dakota
South
Dakota
K>
01
Minn.
Kansas
IS
kla.
Mo. V
~*
Ark. >
/
Delaware
Maryland
D.C.
Figure 1. U.S. Bureau of Census Regions (1969). These regions are used
by the Bureau as a basis for compiling regional industrial statistics and are
slightly different from the U.S. Public Health Service Regions.
-------
V I . I
"7 ^
I
t
1
.
-t
1 X
1 A
1
r
i
A Y
~) *
1
,i
-----
I—
1
s
s
46
7 J~
Value added by manufacture,
industrial chemicals, SIC #281,
$ millions.
States with over $200 million
| States between $100 and $200 million
- Not reported
i Metropolitan areas with over $100 million in value
added by manufacture for chemicals and allied products, SIC #28
Figure 2. Areas of concentration of industrial chemical manufacture,
1*967. (From Reference #66)
-------
Two other areas of heavy industrial chemical manufacture are the east-
south-central region and the State of California. In the east-south-central
region the industry is centered in West Virginia and Kentucky, while in
California the industry is concentrated around the two large metropolitan areas
of San Francisco and Los Angeles.
Nationally, regions containing a high incidence of industrial chemical
manufacture coincide with areas of high population concentration (Figures 2
and 3). There Is a tendency for those states with a high proportion of their
population concentrated in urban areas to also contain substantial industrial
chemical manufacturing. A listing of the ten metropolitan areas with the
highest chemical manufacturing activity includes most of our largest urban areas
(Table 4). Although the listing is by chemical and allied product manufacture,
it is representative of the industrial chemical industry.
Another indication of basic chemical manufacturing activity is the total
number of chemical plants in an area. The number of manufacturing plants with
20 employees or more (for 1967) was tabulated by region and compared to value
added by manufacture. The complete table along with the states within each
region can be found in the appendix,. The middle-Atlantic, east-north-
central, and west-south-central regions were found to have the greatest industrial
chemical activity. The middle-Atlantic region contains over 24 percent of the
plants in the U.S. engaged in manufacturing industrial chemicals, and over 17
percent of value added by manufacture for the industry. The east-north-central
area contains over 18 percent of the plants and over 15 percent of value added
by manufacture, while the west-south-central area contains over 14 percent of
the plants and over 26 percent of the value added by manufacture.
The six states exhibiting the greatest concentration of industrial
chemical manufacture in terms of number of plants and dollar business size are
shown in Tables 5 and 6.
27
-------
•J
o
20,000,000
15,000,000
10,000,000
5,000,000
2,000,000
1.000,000
500,000
Figure 3.
1960 Census)
Total U.S. population, urban and rural, by states (1960). (From
-------
TABLE 4
THE TEN METROPOLITAN AREAS WITH THE HIGHEST CHEMICAL MANUFACTURING ACTIVITY
CHEMICAL AND ALLIED PRODUCTS INDUSTRY-SIC #28
(1967)*
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
*From
Metropolitan area
New York, N.Y. , Northeastern
New Jersey standard consolicated
area.
Chicago, 111., Northwestern
Indiana standard consolidated
area.
Chicago, 111.
Newark, New Jersey
Philadelphia , Perm .
New York City
Hous ton , Texas
Los Angeles-Long Beach, Cal.
Cincinnati, Ohio, Ky. , Ind.
St. Louis, Mo. -111.
Reference #66.
Value added by manufacture,
millions of dollars
3,290
1,310
1,120
1,120
1,020
895
836
575
529
487
29
-------
TABLE 5
THE SIX STATES WITH THE GREATEST NUMBER
OF INDUSTRIAL CHEMICAL PLANTS, 1967*
Industrial chemical plants
State (20 employees or more)
1.
2.
3.
4.
5.
6.
New Jersey
Texas
California
Ohio
Pennsylvania
Illinois
128
85
81
70
60
53
*From Reference *66.
-------
TABLE 6
THE SIX STATES REPORTING THE HIGHEST
VALUE ADDED BY MANUFACTURE FOR
INDUSTRIAL CHEMICALS, 1967*
Value added by manufacture
State Millions of dollars
1. Texas $1,450
2. New Jersey 787
3. West Virginia 582
4. Tennessee 522
5. Louisiana 507
6. Ohio 413
*From Reference #66.
31
-------
Texas Is second in number of plants, but has almost twice the value
added by manufacture for Industrial chemicals as the second highest state, New
Jersey. This figure illustrates graphically the importance of natural gas and
petroleum as raw materials for organic chemical synthesis.
The nature of the chemicals produced differs from region to region (Figure
4). In the middle-Atlantic region, miscllaneous organic chemicals predominate;
in the east-north-central region, there is an almost equal division between
organic and inorganic chemicals manufacture, while in the west-south-central
region, the manufacture of organic chemicals is predominant. In the Pacific
region, inorganic chemicals lead by a wide margin.
These regions have built up their chemical industry largely on the basis
of raw material availability and cost. Raw materials for use in manufacturing
inorganic chemicals depend to a large extent on water transportation, while
oil and gas for use in making organic chemicals are generally transported by
pipe line.
Characteristics of the Producing Companies
The companies which produce industrial chemicals range from small independent
companies with one or two products to giant multiplant corporations employing
thousands of people and making thousands of products. Chemical sales are
dominated by the large multiplant corporations, many of which produce chemicals
and allied products along with non-chemical products. The economy of scale
concept (large units operate more economically) seems to be generally applicable
for production of industrial chemicals. Thus the large companies produce
chemicals at lower prices in most instances and thereby obtain a larger share
of the market.
The major chemical producers include some of the largest corporations in
-------
1200_
1509
-------
TABLE 7
THE FIFTY LARGEST COMPANIES IN CHEMICAL SALES
IN THE UNITED STATES*
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Company
Du Pont
Monsanto
Union Carbide
Dow Chemical
W. R. Grace
Standard Oil (N.J.)
Celanese
Allied Chemical
Hercules
me
Occidental Petroleum
American Cyanamid
Shell Oil
Eastman Kodak
Stauffer Chemical
Uniroyal
Phillips Petroleum
Rohm and Haas
Mobil Oil
Cities Service
Borden
Standard Oil (Ind.)
Ashland Oil****
Continental Oil
IMC
Ethyl Corp
Gulf Oil
Diamond Shamrock
01 in
American Can
National Lead
PPG Industries
Air Reduction
Chemical sales
($ million)
$3250
1711
1675
1450
958
933
917
869
639
625
571
522
513
507
478
476
447
423
417
358
354
342
342
333
332
331
315
314
298
278
275
261
254
Total income** Chemical sales as percent
($ million) of total income
$3481
1810
2686
1723
1761
15873
1256
1278
718
1387
1815
1040
4008
2644
478
1436
2130
428
7089
1461
1681
3994
1082
2443
502
512
5657
528
1011
1633
876
1058
440
94%
94
62
84
54
6
73
68
89
45
31
55
13
19
100
33
21
99
6
25
21
9
32
14
66
65
6
59
29
17
32
25
58
Company S.E.C.
class***
281
281
281
281
281
291
281
281
281
281
509
281
291
383
281
301
291
281
291
291
202
291
291
291
287
281
291
281
281
341
285
321
281
-------
TABLE 7, continued
in
Rank
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Chemical sales
Company ($ million)
US Steel*****
Tenneco
B. F. Goodrich*****
American Enka
Witco Chemical
Pennwalt
Pfizer
Koppers
Air Products
Chemetron
Swift*****
Reichhold
Goodyear*****
GAP
Wyandotte
Sinclair Oil
National Distillers
250
242
240
239
221
208
200
199
185
179
170
161
160
150
147
143
136
Total income** Chemical sales as percent
($ million) of total income
4609
2101
1144
239
224
407
736
449
205
244
2832
161
2941
571
148
1478
958
6
12
21
100
99
51
27
44
90
73
6
100
5
26
99
10
14
Company S.E.C.
class***
331
291
301
281
281
281
283
281
281
281
201
281
301
281
281
291
208
*From Reference //10.
**A11 financial data for fiscal 1968.
***According to "66 Directory of Companies Filing Annual Reports with the Securities and Exchange Commission,
1967". SEC classifications are as
201 meat products
202 dairy products
208 alcoholic beverages
281 basic chemicals
283 drugs
follows:
285 allied products
287 agricultural chemicals
291 petroleum
301 tires
321 glass products
331 steel
341 metal cans
383 photo equipment
509 miscellaneous wholesaler
****Before extraordinary, non-recurring items.
*****Chemical and Engineering News estimate.
-------
the country. Of the 500 largest Industrial companies in 1963, 29 obtained
approximately one-third or more of their sales from chemicals, mainly industrial
chemicals.(3) A list of the 50 top firms in chemical sales for fiscal year 1968
(Table 7) was compiled by the staff of Chemical and Engineering News from data
of the Securities and Exchange Commission (SEC).' (10) Of these top 50 companies,
four are in the top 10 companies ranked by sales in the Fortune compilation
of the 500 largest industrial corporations—1968.(28) Nineteen are in the top
50, 29 are in the top 100, and all 50 appear within the Fortune top 500. The
Fortune listing also showed four predominantly industrial chemical companies
as members of the billion dollar sales club; these are du Pont, Monsanto, Union
Carbide and Dow Chemical, and three others were very close to this mark.
The SEC classifies industries according to their predominant manufacture
(Table 7). The SEC 281 classification, basic chemicals, is a broader definition
than the Bureau of the Census 281. It includes industrial chemicals and gases,
bulk specialty chemicals, plastic materials and resins, synthetic rubber,
man-made fibers, and some fertilizer and agricultural chemicals. Even with
this broad definition, however, only half of the top 50 chemical producers are
classified by SEC as basic chemical producers; the other 25 are scattered
among 13 other SEC groupings. An analysis of the 25 industrial chemical producers
shows their combined chemical sales of $16.77 billion to be only 71 percent
of their total sales. The 25 non-chemical corporations had combined chemical
sales of $8,26 billion—or 33 percent of their $25.03 billion in total sales.
These figures illustrate the diffuse nature of the chemical industry, in that
basic chemical companies produce significant volumes of non-chemicals, and
non-chemical companies, led by the major oil companies, produce large volumes
of industrial chemicals.
To reflect the activity and degree of dominance of the larger companies
-------
in a particular industrial sector, the Bureau of the Census has computed
production value (concentration) ratios. The total shipments in seven
categories of industrial chemicals and the percentages attributed to the top
4, 8, 20 and 50 companies are tabulated on Table 8.
Four of the companies shown on the table sold 43 percent of the
entire 1967 output, eight of them sold 52 percent, and the 20 largest sold
76 percent of the total. The eight largest dominated the sales by 2/3 of the
total or more in the fields of alkalies and chlorine, industrial gases, cyclic
compounds, intermediates and crudes, and inorganic pigments. The spread was
greatest in the manufacture of organic and inorganic chemicals.
When the 2,030 plants in the various #281 classifications are examined
relatively according to the number of employees (Table 9), it is interesting
to note that 1,600 plants, or 79 percent of the total of 2,030, have less than
100 employees. Only 105 plants, or 5 percent of the total have more than 500
employees, and less than half of these have over 1,000 employees. These
figures explain why industrial chemicals have remained relatively stable
in price over the years. Large-scale operation and automation have reduced
the labor portion of manufacturing cost to a minimum.
Practically all of the plants producing industrial gases are small; 98
percent have fewer than 100 employees. These plants are located throughout
the country, close to their markets, since transportation costs for these
gases are high.
Role of the Industry in the Economy
The chemical industry is a major segment of U.S. industry and produces
the basic builjing-blcck chemicals used either directly or indirectly in the
manufacturing activities of almost all other industries. Between 1958 and
37
-------
TABLE 8
PERCENT OF VALUE OF SHIPMENTS ACCOUNTED FOR BY THE LARGEST COMPANIES
IN THE INDUSTRIAL CHEMICAL INDUSTRY: 1967 AND EARLIER YEARS*
Value of shipments
Code
2812
2813
2815
2816
2818
2819
*From
Industry and
INDUSTRIAL
CHEMICALS
Alkalies ....
and ....
chlorine ....
• • • •
• • • •
• • • •
Industrial . .
gases ....
• * • •
• • • •
• • • •
• • » •
• • • •
Cyclic ....
intermediates
and
crudes
Inorganic ....
pigments ....
• • • •
• • • •
• • • •
Industrial . .
organic ....
chemicals . . .
El • c • C • ••••
• • • •
Industrial . .
inorganic . . .
chemicals . . .
n • c • c • ••••
(NA)
Reference #69.
year
Companies
(number)
Total
(million
dollars)
Percent accounted
4
Larg-
est
com-
panies
8
Larg-
est
com-
panies
20
Larg-
est
com-
panies
for by
50
Larg-
est
com-
panies
A "company" is defined for this
purpose as the total of its
industrial establishments.
1967.
1966.
1963.
1958.
1954.
1947.
1967.
1966.
1963
1958
1954.
1947.
1935.
1967.
1963.
1967.
1966
1963.
1958.
1954.
1967.
1966.
1963.
1958.
1954
1967.
1966.
1963.
1958.
not
19
(NA)
19
18
17
18
113
(NA)
104
111
101
69
(NA)
115
120
65
(NA)
69
67
73
339
(NA)
343
250
202
408
(NA)
404
(NA)
available
720
783
652
488
400
209
589
550
425
232
168
93
(NA)
1,597
1,213
549
582
485
403
371
6,380
6,540
4,840
3,070
2,200
4,250
3,840
3,490
2,610
63
63
62
64
69
70
67
72
72
79
84
83
79
45
53
59
64
68
69
67
45
46
51
55
59
27
29
31
34
(X) not
88
88
88
89
90
93
84
88
86
88
88
88
87
64
71
78
83
84
83
83
58
60
63
70
73
43
46
49
50
applicable
100
(NA)
100
100
100
100
95
(NA)
95
94
93
94
(NA)
83
88
95
(NA)
96
96
96
75
(NA)
79
85
87
64
(NA)
71
(NA)
(X)
(NA)
(X)
(X)
(X)
(X)
99
(NA)
99
98
(NA)
(NA)
(NA)
97
99+
99+
(NA)
99+
99+
(NA)
92
(NA)
93
96
(NA)
85
(NA)
88
(NA)
-------
TABLE 9
SIZE OF CHEMICAL PLANTS BY NUMBERS OF EMPLOYEES (1967)
(INCLUDING PLANTS WITH LESS THAN 20 EMPLOYEES)*
Total
SIC category no. plants
281
Industrial 2032
chemicals
2812
Alkalies & 44
chlorine
2813
Industrial 507
gases
2815
Cyclic
interned. & 177
coal tar
crudes
2816
I norganic 98
pigments
2818
Organic 488
chemicals
n.e.c.
2819
I norganic
chemicals 718
n.e.c.
Number of plants with an average of
1-100 employees 100-500 employees 500-1000 employees over 1000 employees
number percent number percent number percent number percent
1600 79 327 16 57 3 48 2
14 32 18 41 6 13.5 6 13.5
494 98 12 2 1 - -
113 64 50 28 744 4
71 73 23 23 1 13 3
339 70 108 22 21 4 20 4
569 79 116 16 21 3 12 2
-------
1967, shipments of the chemical and allied products industry have been at
levels equivalent to over 5 percent of gross national product.(8) In 1969 the
chemicals and allied products industry accounted for over 2 percent of the
national income for all Industries ($16.3 billion out of $769.5 billion), and
represented almost 18 percent of national Income for the nondurable goods
industry ($86.9 billion).(60)
The position of the chemical and allied products industry, and its largest
segment, the industrial chemical industry, relative to all U.S. industry is
shown in Table 10. Although the chemical and allied products industry accounts
for only 4.4 percent of all manufacturing employees, the value of the products
produced and Its dependence on large sophisticated production units, is reflected
by its contribution of 7.6 percent of the value of all shipments, 14 percent
of all new capital expenditures, and 9.1 percent of the value added by manufacture
for all industry. Of the 21 Census industrial groups, 11 had a greater total
employment than the chemical and allied products industry, but only four industries
(namely: food and kindred products; machinery, except electrical; electrical
equipment and supplies; and transportation equipment) had a greater value added
by manufacture. Only the above four, plus the primary metals industry, had a
greater value of shipments, and only the primary metals industry had greater new
capital expenditures. This last fact illustrates the importance of the chemical
industry to the existence and growth of many non-manufacturing industries such as
the construction industries and its allied businesses.
Almost a third of the value added by manufacture of the chemical and
allied products industry is contributed by the industrial chemical industry,
and a large 43 percent of the new capital expenditures are attributable to the
industrial chemical industry. Compared to all manufacturing industry, industrial
chemicals account for 1.3 percent of all employees, 2.5 percent of the value
of shipments, 3 percent of value added by manufacture, and 6 percent of new
-------
TABLE 10
ECONOMIC POSITION OF THE INDUSTRIAL CHEMICAL INDUSTRY (1967)*
Industry
All employes
Value added by manufacture
Value of shipments
New capital expenditures
Number Percent
of all
indus-
(Thous) try
Percent Total Percent Percent Total Percent Percent Total Percent Percent
of chem. dollars of all of chem. dollars of all of chem. dollars of all of chem.
& allied (mill.) indus- & allied (mill.) indus- & allied (mill.) indus- & allied
products try products try products try products
All manuf.
industry 19,400
$259,000
$555,000
$20,300
Chemical
and
allied
products
industry
834 4.4
$ 23,400 9.1
$ 42,200 7.6
$ 2,830 14.0
indus-
trial
chemical
industry
249 1.3
29.2 $ 7,700 3.0
33.0
$ 14,100 2.5
33.4
$ 1,220 6.0
43.0
*From Reference #67 and 68.
-------
capital expenditures. Only six of the 20 major industry groups had greater new
capital expenditures than the industrial chemical industry, and it contributed
more to value added by manufacture than half of the major industry groups.
Growth of the Industry
The growth rate of the chemicals and allied products industry during the
sixties has been above average. Value added by manufacture grew 90 percent
over the period from 1958 to 1967, compared to an 80 percent growth of all
manufacturing industry. From 1963 through 1968, the average annual growth
rate of shipments of this industry was 8 percent. In 1969 the growth fell to
6 percent, with this same comparatively low rate of growth forecast for 1970.(9)
Industrial chemical industry growth, as shown on Table 11 for the 1958-1967
period at 83 percent, was not as large as that of its major group, and just
slightly greater than for all manufacturing industries. Organic chemicals
SIC 2818, however, showed a 107 percent increase in value added by manufacture
over the same period, while Inorganic chemicals, SIC 2819, showed only a 56
percent increase. More recently, the increase in value of shipments for industrial
chemicals has been greater than that of chemicals and allied products. In
1969, industrial chemical shipments increased 8 percent to $16.6 billion. This
figure is expected to increase about 7 percent to $17 billion in 1970. Continuation
of this 7 percent annual increase has been forecast through 1975. The largest
contributor to this recent growth is organic chemical shipments. In 1969
miscellaneous organic chemicals showed an increase of 11 percent in value of
shipments. They are projected to show an 8 percent increase to $8.9 billion
in 1970. This is an overall increase of 35 percent from the $6.58 billion in
1958.(9)
Among the organic chemicals, the fastest growing group is the miscellaneous
-------
TABLE 11
GROWTH STATISTICS FOR THE INDUSTRIAL CHEMICAL INDUSTRY, 1958-1967*
Value of shipments
Industrial chemicals
(SIC #281)
% increase from 1958
Alkalies & chlorine
(SIC #2812)
% increase from 1958
Industrial gases
^ (SIC #2813)
Ul
% increase from 1958
Cyclic intermediates
(SIC //2815)
% increase from 1958
Inorganic pigments
(SIC #2816)
% increase from 1958
Organic chemicals
(SIC #2818)
% increase from 1958
All employees
1958 1963
238,000 237,000
-0.6
20,500 19,600
-4.0
10,600 9,810
-7.8
28,300 27,700
-2.0
11,400 11,500
+1.5
77,400 85,500
+10.4
(millions of dollars)
1967
249,000
+4.5
19,200
-6.2
10,300
-3.2
30,000
+6.0
12,600
+10.8
95,100
+23.4
1958 1963
7,980 11,100
+39.1
504 652
+29.4
277 425
+53.4
934 1,210
+29.8
418 485
+16.0
3,100 4,840
+56.2
1967
14,100
+76.3
720
+42.8
589
+112.6
1,600
+70.9
549
+31.3
6,380
+105.8
Plants
1958 1963
1,650 1,870
-KL3.1
34 38
+5.9
491 456
-7.1
115 141
+22.6
99 96
-3.0
334 464
+38.9
1967
2,030
+22.8
44
+29.4
507
+2.6
177
+53.9
98
-1.0
488
+46.1
Value added by mfr.
(millions of
1958 1963
4,210 6,170
+46.4
306 389
+27.1
174 260
+49.4
403 605
+50.1
236 286
+21.2
1,730 2,730
+58.0
dollars)
1967
7,730
+83.5
419
+36.9
401
+130.5
729
+80.9
316
+33.9
3,570
+107 . 1
Inorganic chemicals
(SIC #2819) 89,900 82,400 81,200 2,750 3,490 4,250 580 674 718 1,470 1,900 2,290
% increase from 1958 -8.3 -9.6 +26.8 +54.2 +16.2 +23.8 +29.5 +56.2
*From Reference
-------
acyclic organic chemicals commonly called "petrochemicals". Other rapidly
growing chemicals are gasoline and lubricating oil additives, photographic
chemicals, ore flotation reagents, flavor and perfume materials, rubber
processing chemicals, plasticlzers, and chemicals for pesticides and
agricultural applications.
The alkali and chlorine industry had the second smallest growth in value
of shipments of all the subgroups over the '58-'67 period, only 43 percent.
Shipments in 1970 are estimated to be about $832 million, up 65 percent from
1958. Production of chlorine for 1970 is estimated to be 10.6 million short
tons, up 6 percent from 1969. This continuing growth in chlorine production
is due to a number of important applications including vinyl chloride monomer,
other chlorinated hydrocarbons, pesticides, and paper and pulp bleaching.
On the other hand, production of soda ash is expected to increase only slightly
since increased demand is expected to be met by the natural form.
Growth of the industrial gas industry has been very high with an increase
of 113 percent in value of shipments from 1958 to 1967. In 1970 value of
shipments are expected to reach $715 million, or a 158 percent increase from
1958 levels. The greatest contributor has been the rapid growth of air
separation plants, where annual growth rates for the period 1958-68 of high
purity nitrogen were 37 percent, high purity oxygen 22 percent and argon 19
percent. During the same period, the annual growth rate for hydrogen was
15 percent, helium 12 percent, and nitrous oxide 8 percent. Future growth
does not appear as bright, however, with overcapacity indicated in some areas.
Growth will probably be selective until demand catches up to the available
supply.(9)
Cyclic intermediates and crudes saw a 71 percent increase in value of
shipments over the 1958-67 period. Total shipments are expected to reach
-------
$2.1 billion in 1970, up a large 125 percent from 1958. This accelerated growth
in intermediates is due to rising demand for production of man-made fibers and
polystyrene and phenolic resins, as well as ortho-xylene, cyclohxane, para-xylene,
phtKalic anhydride, aniline, bisphenol A, and urethane resin precursors.(1)(9)
The slowest growing group of basic chemicals are the inorganic pigments.
The Increase in value of shipments from 1958 to 1967 was only 31 percent. By
1970, value of shipments is expected to reach $725 million, a 74 percent increase
from 1958. One of the fastest growing pigments is titanium dioxide which makes
up about 50 percent cf the industries' sales. However, much of its recent
growth has been as a replacement for other pigments, such as lead.(9)
The inorganic chemicals industry has also exhibited a comparatively slow
rate of growth over the 1958-67 period, with an average annual rate of about
4 percent, and an overall Increase of 54 percent in value of shipments. In
recent years, demand has stagnated for a number of major chemicals used for
production of fertilizers and for industrial production of sulfuric acid and
inorganic compounds containing nitrogen, phosphorous, and potassium. During
1969 many operations were unprofitable, as new plant expansions encountered
reduced demand, which caused price reductions, and many obsolete plants and
marginal operations were phased out. Value of shipments in 1970 is expected to
increase only 4 percent to $4.5 billion, an increase of only 64 percent from
1958.(9)
Although the industrial chemical industry is growing at a fairly rapid
pace, there are two areas where very little growth, and in some cases a decrease
from 1958 levels, have resulted, namely in total employment and numbers of
plants. Total employment over the period Increased only 4.5 percent, a very
small figure considering the 83 percent Increase in value added by manufacture.
Three of the subgroups decreased total employment over the period. Miscellaneous
45
-------
inorganic chemicals exhibited a 9.6 percent decrease in total employment.
The organic chemical industry increased its employment 23 percent over the
period, but value added by manufacture increased 107 percent.
-------
SECTION FOUR: SOLID WASTES OF THE INDUSTRIAL CHEMICAL INDUSTRY
Page
Process Wastes 52
Process Waste Categorization 52
Process Waste Generation 56
Chemical Conversions 57
United Operations 59
Other Sources of Process Waste 62
Parameters Which Influence Solid Waste Generation 68
Figures
5 Solid waste generation from a typical chemical plant 50
Tables
12 Process waste categorization used in this study 54
13 Principal chemical conversions 58
14 Common unit operations 60
47
-------
SECTION FOUR: SOLID WASTES OF THE INDUSTRIAL CHEMICAL INDUSTRY
Industrial chemical plants generate solid wastes with characteristics
probably more diverse than in any other industry. The physical properties
of the solid wastes range from rock-hard clinkers of irregular shape to free
flowing organic tars. They include the normal municipal and commercial type
refuse, consisting of cans, bottles, paper, and garbage, in addition to chemical
wastes of varying composition and characteristics. These solid wastes arise
from all the functions of an industrial plant including administration,
maintenance, and manufacture wherein all materials used will leave the plant
either as a product, a salvageable material, or a waste.
The flow of materials and eventual solid waste generation for a typical
chemical plant is shown in Figure 5. As can be seen from this schematic
diagram, the necessasry materials for offices, cafeteria, manufacturing processes,
etc., are transported either directly to the appropriate plant area or to a
central shipping and receiving area from which they are distributed. Food and
cafeteria supplies and coal or other fuel are normally shipped directly to
the specific use area, while laboratory supplies are normally sent through
shipping and receiving. The materials consumed by the plant operations eventually
become part of the product, or are salvaged or wasted.
Two distinct waste categories are evident from the discussion of total
plant waste generation; these are wastes generated directly by the manufacturing
processes of the plant, or process wastes, and all other wastes, or non-process
wastes.
Non-Process Wastes
Non-process wastes are wastes which are not generated directly by a
chemical manufacturing process. They can be classified into tnree categories
-------
OB
Food and
cafeteria
supplies
Ul
o
NP
Garbage, cans,
cardboard,
bottles,
paper
Office
supplies
Maintenance
supplies
Laboratory
supplies
Process raw
materials
Construction
materials,
tools, etc.
Shipping and
receiving
Laboratory
research
development!
NP
Paper and
cardboard
Manufactur-
ing areas
J
Construction
demolition
renovation
NP
Wood, metal,
glass, plastic,
paper, card-
board
Off-quality
product
Chemical
wastes
NP
Power house
Bricks, con- .
crete, metal,
glass, wood
Flyash and
cinders
NP: Non-process wastes
P: Process wastes
Figure 5. Solid waste generation from a typical chemical plant.
-------
related to their disposal characteristics: namely, combustible waste which
includes paper, cardboard, wood, and plastic; noncombustible waste which
includes glass, brick, concrete, and certain metal wastes such as tin cans;
and salvageable metal which includes metallic wastes that can be sold for
scrap metal.
Chemical plant combustible waste usually contains a lower percentage of
garbage and a higher percentage of dry paper and plastics than municipal refuse,
and therefore has a higher heating value. In terms of the Incinerator Institute
of America's waste classifications,(34) combustible waste from plants with
cafeterias would be type //I waste, rubbish, and those without a cafeteria
would be type //O waste, trash.* Type #1 waste is defined as consisting of
20 percent garbage and 80 percent rubbish with a heat content of 6500 BTU per
lb.; type #0 waste is 100 percent trash and 8500 Btu per Ib. as fired.
Non-process solid wastes result' from the delivery of the materials
necessary to sustain, directly or indirectly, the life of the chemical process.
Practically every operating unit within a chemical plant generates non-process
waste through obsolescence or use of an auxiliary material. Non-process waste
generated by plant operations is specific to a particular operation (Figure 5).
Shipping and receiving operations encounter materials in various kinds
of packaging, e.g., cartons, paper bags, cloth sacks, steel drums, fiber drums,
etc. Most packaging material cannot be reused and is discarded. Steel drums
are an exception since they can often be reconditioned, but they have been
replaced for many applications by fiber drums which are seldom reused.
The use of wooden pallets has greatly increased in recent years as a
result of Improved methods of raw materials handling. The cost of reconditioning
*//] waste (rubbish): highly combustible waste, paper, wood, cardboard
cartons, including up -.o 10 percent treated papers, plastic or rubber scraps,
commercial and industrial sources. #0 waste (trash): combustible waste paper
cartons, bags, wood scraps, combustible floor sweepings, domestic and commercial
sources.
51
-------
pallets Is usually prohibitive, and broken pallets are discarded. Pallets
In good condition can sometimes be returned to the supplier. Where this is
not the case, they must either be used elsewhere in the plant, shipped with
outgoing material, or sent to disposal.
Other plant operations also carry out the same cycle of use, replacement,
and disposal. The cafeteria uses napkins, paper cups and plates, and replaces
broken or chipped glasses and dishes. The laboratory replaces broken or cracked
glassware, and maintenance personnel replace broken or obsolete equipment.
Demolition materials such as bricks and wood which are not economical for
further construction are replaced by new materials. All this used and replaced
material, if it cannot be salvaged or reconditioned, is wasted.
Process Wastes
Process wastes are wastes generated directly from a chemical process.
They are related to the wide variety of industrial chemicals and their
manufacturing processes. Just as the chemicals differ widely in character,
so are the process wastes from different processes and plants extremely variable
in composition and characteristics. Non-process waste composition and characteristics
have been reported in detail in a number of publications.(16,22,35,44) Industrial
chemical Industry non-process waste is quite similar in composition to those
reported. Chemical plant process waste is specific to the industrial chemical
industry and has received little attention. This lack of information was a
reason for the undertaking of this study.
Process Waste Categorization. A number of methods for categorization of
process wastes was considered, many quite detailed. The categories chosen
for this study were kept general to allow the industry-wide waste inventory to
be accomplished within the scope of the program. Specific categories based
-------
on waste characteristics or chemical composition would require a very large
number of categories and detailed information on each reported waste well
beyond the intended scope of this study. In addition, the categories selected
had to be expressed in terms familiar to plant personnel to assure a
consistent response on the mail questionnaire. Following discussions with
chemical plant personnel during initial plant visits, the categories defined
in Table 12 were decided upon.
Sludge. Sludge is a broad category including all types of solid wastes
except dry powder and granular material. Most filter residues and flyash and
some off-quality product are also sludges. Wastes were classified in the more
specific categories If possible, and classified as sludge only if they did
not fit these other classifications.
Sludges have a variety of physical and chemical characteristics. In terms
of moisture content, they can vary from a wet semisolid to a hard cake. Many
are wet when first removed from the process, and upon dumping will dry to a
hard solid. They can be either organic or inorganic and consist of a chemical
mixture such as the impurities in an ore, or they can be relatively pure
chemical compounds such as ferrous sulfate crystals or gypsum.
Filter Residue. Filtration is usually applied to remove product solids
from a process stream when the solids content is high and the liquid is to be
discarded. It is also applied when the solids content is low and high clarity
of product liquid is desirable. In the latter case, precoat filters are
applicable or filter aid is added to the filter feed.
Filter residues differ widely in physical characteristics but are
invariably considered as solid wastes together with a certain quantity of
filter membranes, whether they be cloth or paper.
Tars. Tars are associated with production of organic chemicals from
53
-------
TABLE 12
PROCESS WASTE CATEGORIZATION
USED IN THIS STUDY
Sludge:
Filter residue
Tars:
Off-quality
product:
Flyash:
Other:
A soft mud, slush or mire usually
resulting from dewatering of
slurries without filtration.
Material removed from the process
stream by a filtering device (filter
cake). It sometimes contains the
filter media also.
An organic residue of mixed chemical
composition usually appearing as a
still bottom or distillation residue.
A chemical product not meeting the
commercial specifications for the
particular product and not of
sufficient economic worth to warrant
further purification or recovery.
The residual solid ash remaining
from the combustion of coal, either
as furnace bottom ash or that
caught by stack emission controls.
Any chemical waste that does not
fit into one of the above categories.
Examples here are: spent catalysts;
contaminated containers, etc.
-------
coal and oil. There are usually impurities in the feedstock of a process,
which are removed as distillation residues or still bottoms. Most organic
substances when subjected to a high temperature in the absence of air,
undergo simultaneous decomposition to smaller molecules and polymerization to
higher molecular weight char or coke with the production of a dark-colored
byproduct called tar. The tar may contain many valuable chemicals which can
be extracted by refining. When all of the economically important chemicals
have been extracted from the tar, the residue is wasted. Waste tars are
usually mixtures of high boiling compounds, the composition of which is often
unknown. Tars can exist both as a solid or a liquid at room temperature,
depending upon their chemical composition. Both solid and liquid forms may
be generated through identical means, their chemical compositions may be
similar, and they are most often disposed of together, either by incineration
or land disposal but rarely into receiving waters. In this study all tars
were considered to be solid wastes.
Off-Quality Product. Improper conditions or faulty operation of a
process can result in a chemical product that does not meet commercial
specifications. In many cases, this means the product contains too great a
concentration of impurities or the chemical composition has been altered to
the extent that it is undesirable for its intended application. Such a material
is commonly called an off-quality product. Sometimes the material can be sold
as an inferior grade of the intended product, or recycled back into the
process, or separately refined to obtain the original product. Where it is
not economical to recover the material, it is wasted. Off-quality product
waste can be obtained from practically every chemical process, though Infrequently
in most cases, since wasting it is highly undesirable and often avoidable.
Thus, even some processes which do not generate solid wastes in normal operation
55
-------
nay occasionally have to dispose of some off-quality product solid waste.
Since off-quality product is obtained from many processes, the chemical and
physical characteristics of the waste are highly variable.
Flyash. Flyash was considered to be in the process waste category since
it is the result of the combustion of coal to produce heat energy. The heat
is usually in the form of steam which is utilized for plant operations. All
coals contain a certain percentage of inert material which on combustion is
not chemically converted to gaseous products but remains a solid, either as
flyash collected in stack control devices or as bottom ash or slag remaining
in the boiler. Typical coal ash contents range from 3 to 13 percent by weight.
Ordinarily the carbon content of flyash from an industrial powerhouse is much
higher than that from a utility. Industry is reluctant to operate its
powerhouses at a high efficiency of combustion because of much higher Investments
required. It is not unusual for the flyash from industry to contain up to 12
percent carbon. In addition to adding to the solids load, the high carbon content
prevents the use of the flyash in pozzolanic cement.
Other. In addition to the above waste types, a few wastes were found
that did not fall within one of the waste categories and were termed "other"
wastes. Included in this group are dry solid chemicals in powder, pellet, and
granular form, many of which were spent catalysts in pellet form. Some
chemically contaminated containers and similar materials were considered "other"
process wastes if they could not be handled with ordinary trash, but had to
be disposed of with the process wastes. In addition, certain major items of
equipment belonging to a chemical process were included if they were peculiar
to the particular process, and were not disposed of with non-process wastes.
An example would be the waste concrete cell parts from a chlorine-caustic cell.
Process Waste Generation. Process vastes are not the result of use or
-------
replacement but are generated by process operations associated with direct
chemical manufacture. The operations are either chemical conversions or
unit operations. Chemical conversions are processes where chemical changes
occur. The operations within a chemical manufacturing process are the sources
of solid wastes associated with the manufacture of a particular chemical.
Chemical conversions and unit operations are not necessarily tied to
production of a specific chemical. Frequently, the equipment used to carry
out the conversions and operations is used for manufacturing many different
chemicals. For example, the equipment for the chemical conversion of nitration
consists of a cast-iron reactor called a nitrator. It can be used in the
nitration conversion for many chemicals such as nitrobenzene, nitronaphthalene,
or TNT. Other examples are the unit operations of filtration and evaporation
which are universally used in chemical manufacturing processes.
The solid wastes generated by similar chemical conversions or unit
operations are not necessarily produced in the manufacture of all chemicals
which utilize these same basic steps. In fact when the same equipment is used
to produce a different chemical, no solid waste may be generated at all.
Chemical and physical operations many times act together in solid waste
generation. Quite frequently, chemical reactions will produce two products,
only one of which may be useful. When this happens, the useless reaction
product is generally separated by physical means such as filtration or distillation.
Chemical Conversions. There are a great many chemical conversions used
in the manufacture of industrial chemicals, some of which may generate solid
waste. The chenical conversions ara designations for groups of reactions
involving similar chemistry, such as: Sulfonation, which is the formation of
a sulfonic acid, a compound containing the sulfonic group in its molecular structure,
57
-------
TABLE 13
PRINCIPAL CHEMICAL CONVERSIONS*
Acylation
Alcoholysis
Alkylation
Amination by reduction
Ammonolysis
Aromatizatlon or cyclizatlon
Calcination
Carboxylation
Causticlzation
Combustion (uncontrolled
oxidation)
Dehydration
Diazotization and coupling
Double decomposition
Electrolysis
Esterification (sulfation)
Fermentation
Friedel-crafts (reactions)
Halogenation
Hydroformylation (oxo)
Hydrogenation and dehydrogenation
Hydrolysis and hydration
(saponification, alkali fusion)
Ion exchange
Isomerization
Neutralization
Nitration
Oxidation (controlled)
Polymerization
Pyrolysis or cracking
Reduction
Silicate formation
Sulfonation
*See Reference #49 for all chemical conversions.
-------
e.g., the conversion of benzene into benzene-sulfonic acid Halogenation,
which is the incorporation of one of the halogen elements, usually chlorine
or bromine, into a chemical compound, e.g., benzene treated with chlorine
to form chlorobenzene and, Hydrolysis, in which water acts upon another
substance to form one or more entirely new substances, e.g., the reaction
of the ions of a dissolved salt to form various products, such as acids,
complex ions, etc. The principal chemical conversions are listed in Table
13.
Solid waste generated by chemical conversions falls into four categories:
(a) Solid byproducts which are formed by the -process reactions and are not
further consumed in the process, (b) Solid catalysts necessary for the reaction,
not consumed during the reaction, and that cannot be reused, (c) Any solid
Impurities in the feed material or other compounds, which are not involved in
the reaction, (d) A portion of the feedstock material that did not undergo
the reaction and cannot be recycled back into the process. The discussion in
Section Five of solid waste generation from the manufacture of specific industrial
chemicals includes many examples of solid wastes generated by chemical conversions.
Unit Operations. Whereas chemical conversions change compounds into new
chemical entities, unit operations physically extract or separate desired chemicals
from parent materials. It is apparent that the common unit operations cover
many of the steps found in almost every process (Table 14). These physical
operations may comprise an entire chemical manufacturing process or operate
in conjunction with a chemical conversion, by preparing the feedstock material
before it enters the conversion vessel, separating the products and byproducts
produced from the conversion, and purifying the final product. Each of these
functions of unit operations may generate solid wastes by removing a solid
material from the process stream.
59
-------
TABLE 14
COMMON UNIT OPERATIONS*
Pumping
Conveying
Packaging
Storing
Grinding
Agglomerization
Compacting
Evaporation
Heat transfer
Precipitation
Condensation
Refrigeration
Distillation
Gas absorption
Solvent extraction
Humidification
Drying
Leaching
Crystallization
Sublimation
Screening
Flotation
Gaseous diffusion
Dialysis
Electrodialysis
Filtration
Mixing
Agitation
Ion exchange
Centrifuging
Thickening
Clarifying
Electrostatic separation
*See Reference #49 for all chemical conversions.
-------
Purification or separation by precipitation, filtration, and distillation
generate the largest quantities of solid wastes. These operations may remove
wastes formed by chemical conversions from the process stream, or they may
remove wastes originally present in the feedstock material as impurities.
Precipitation and Settling. The purification of solutions by the removal
of undesirable constituents as insoluble material is a well-known chemical
engineering principle. The physical state of the chemical impurity can be
changed in several ways, such as by raising or lowering the pH value by acid
or alkali addition. When the Impurity is present as a suspended solid, the
use of coagulants such as aluminum or iron salts may be called for. The
resulting solid may be separated from the puri'fied solution by settling,
centrifuging or filtration.
The most common means of separating solids from liquid is by sedimentation
in tanks or ponds. If the quantity to be removed is relatively small, ponds
which can be cleaned occasionally are feasible. Settling ponds are not
ordinarily used to purify liquids which are considered chemical products.
Ponds are used on water streams which are clarified for process or cooling
purposes. In most cases, the stream is the plant effluent, and clarification
is practiced to minimize pollution of watercourses.
Distillation and Evaporation. Distillation is used to separate compounds
in a liquid mixture by vaporization and condensation. Evaporation is akin to
distillation, although it is usually applied to concentrate a liquid by removal
of water. Solid wastes can result from either of these unit operations depending
on the chemicals involved. Distillation can produce "tars" as still-bottoms,
and evaporation can lead to crystallization of an impurity from a concentrated
liquid. Examples of tar generation from specific chemical processes are
discussed in Section Five.
61
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Other Sources of Process Waste. Significant solid waste quantities are
generated by other functions related to chemical processing which are not chemical
conversion processes or unit operations.
Power Generation. The solid wastes from the use of coal to produce
steam and/or power can be a major consideration, particularly in large chemical
plants. These wastes consist of bottom ash or slag and flyash. Flyash is no
longer acceptable for discharge into the atmosphere. It is usually removed
by electrostatic precipitation or other means, and becomes a solid waste. It
is usually collected in a dry state, but is frequently transported hydraulically
to a settling pond. Handling economics determine the method used.
Air Pollution Control. The capture of solid particulate matter by air
pollution control equipment usually results in solid waste. Solids removal
from gas streams can be accomplished by such equipment as baghouses, electrostatic
precipitators, single cyclones or multiclones, settling chambers, and various
scrubbers. Equipment using a liquid as the collection medium, such as scrubbers
and wet cyclones, may send the effluent directly to receiving waters or to
waste water treatment where the solids are removed. The solids removed in such
devices are usually not economically recoverable and are discarded.
Common applications for control equipment are for grinding, pu I vi-r I y 1 ny ,
drying, and combustion operations. Some drying nnd calclnlriK cipri ,-il Inn*:.
particularly rotary dryers and kilns, can be dusty. Heated air or combustion
products passing through the dryer or kiln also picks up dust. At times,
product quality control requirements do not permit recycling of the dust to the
process, and it is discarded.
Examples of processes emitting air-entrained dust requiring air pollution
control are: calcium carbide production in electric furnaces; lime production
in vertical and rotary kilns; and various materials handling operations. In
-------
the manufacture of calcium carbide, lime and coke are charged to an electric
furnace wherein the lime is reduced by coke to calcium carbide and carbon
monoxide. A carbide furnace may release as much as 96,000 cubic feet of gas
per minute containing approximately 1.0 to 3.0 grains of dust per cubic foot.(A)
A high-efficiency collector is necessary to remove the small particles of
lime present in the gas. An impingement scrubber is often used for this
purpose. The fluid waste from the collector is usually sent to ponds or
lagoons where the solids are removed through settling, or is sent first to
thickeners, where the thickened sludge is removed and disposed of in large
diked areas.
Coke used in the manufacture of calcium carbide must be crushed, sized,
and dried. This procedure generates substantial quantities of dust which are
controlled by mechanical and bag collectors. Additional dust is generated
when the calcium carbide is crushed and sized prior to commercial usage.
Lime kilns also release substantial quantities of dust. Rotary lime
kilns have been found to emit as much as 26,000 cubic feet of gas per minute
with a dust load of approximately 8 grains per cubic foot. Vertical kilns can
emit 33,500 cubic feet of gas per minute with a dust load of 0.9 grains per
cubic foot.(4) Total dust quantities can range from 5 to 15 percent by weight
of the lime produced for rotary kilns, to about one percent for vertical
kilns.(21) Multiple cyclones and wet scrubbing systems have also been used to
control dust emissions from this process.
Solid materials collected by air pollution control devices often can be
recycled back to the process. An example of partial recyling of materials
removed in control devices, although not part of SIC //281, is in a cement kiln
where relatively large particles caught In the primary collectors (cyclones)
are in essence partially calcined clinker and can be readily returned to the
63
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kiln. On the other hand, fine materials reaching the precipitator or baghouse
are rich in alkalis (because of the high volatility of sodium and potassium).
Such materials must be discarded; excessive amounts of these materials weaken
the cement.
Waste Water Treatment. Chemical plants usually have waste water streams
from both sanitary facilities and process operations. Normally the two streams
are treated and disposed separately, although some plants do have combined
treatment. Treatment facilities for this waste water stream may consist of
primary and/or secondary treatment.
Primary treatment consists mainly of removing suspended solids from
the waste stream. Settling tanks, thickeners, centrifuges, flocculation tanks,
ponds or lagoons, are used, depending on the degree of removal required and
the type of solids to be removed. The solids settle out to form a sludge
commonly called primary sludge.
Secondary water treatment usually involves biological treatment of the
waste waters. Waste waters will often contain dissolved organic materials,
particularly from chemical plants involved in organic syntheses. Such wastes
can contain alcohols, aldehydes, phenols, amino compounds, organic acids, and
others. Without secondary treatment, most of these compounds will break down
in the receiving waters to simpler organic reaction products through the
action of bacteria. In utilizing this organic matter as food, the bacteria
consume the oxygen present in the receiving water for their metabolism and
growth. If the quantity of organics is great enough, however, the oxygen content
can be completely depleted or dropped below levels which can support other
aquatic life. Present State and Federal laws prohibit such misuse of receiving
streams.
Sometimes the organic matter can be isolated or segregated so that
-------
salvage or chemical destruction can be undertaken. In many cases, however,
the organic matter reaches the plant's sewer system and is diluted too far for
economical recovery. In these instances, biological treatment may be the
only practical answer.
If the volume of the waste stream is relatively small, biological
treatment by a process known as "extended aeration" can be utilized. This
process usually involves facilities for 24-hour aeration, in conjunction with
sludge removal and recycling back to the aeration chamber. In this way, the
sludge is almost completely depleted so that the effluent carries very little
in the way of suspended solids to the receiving waters.
When flows become large, plant size becomes a limiting factor, and a
process known as "activated sludge" becomes applicable. This process involves
subjecting the wastes, inoculated with sewage bacteria, to a reaction period
of about four hours followed by "solids" separation in a clarifier. These
"solids" are the result of bacterial growth of the synthesizing of cellular
material. They act to absorb the organic matter in solution so that the
liquid portion is greatly reduced in its oxygen demand. While the waste water
is not completely "pure", the biochemical oxygen demand content is low enough
to permit discharge to a receiving waterway.
During the four-hour aeration period, the sludge content of the aerated
mixture must be controlled in order to maintain oxidizing conditions; i.e.,
a certain amount of sludge must be removed for disposal. This is accomplished
by passing the effluent from the aeration tank through a clarifier to separate
all of the solids by settling. Some of the sludge is sent to waste while the
rest is returned to the aeration tank.
The activated sludge is highly absorptive, and a large amount of the
organic matter In the original waste is removed with the wasted sludge. The
65
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proper disposal of this sludge is the major solid waste problem of the activated
aludge process. It will develop odors if piled in the open, and therefore
must be buried, burned, or barged to the ocean. Each of these methods can be
costly.
An accurate estimate of biological treatment used by the industrial
chemical industry has not been made. This survey was too broad to permit this
level of detail. It is certain, however, that with stricter enforcement of
regulations governing water quality, this method of treatment will expand sharply
within the next few years.
The removal of nonbiodegradable materials from waste waters may also
generate solid wastes. Such heavy metals as iron, copper, zinc, and cadmium
are removed by precipitation with the addition of alkali. Addition of soluble
barium salt, such as barium sulfide, is used to precipitate chromium (as
chromates). Acidic wastes are normally neutralized with lime and other
inexpensive alkali which may precipitate a solid calcium salt. Conversely,
sulfuric acid and waste hydrochloric acid are commonly used to neutralize
alkaline waste waters which may also precipate salts.
Pilot Plants. Pilot plants are used to evaluate a particular chemical
production process before construction of a full-scale units to large
tonnage quantity approaching full scale. During the testing procedures, a
variety of solid wastes may be generated.
Any waste which is inherent to the basic production process will be
generated by the pilot unit. In addition, certain malfunctions in the process
may produce undesirable side reactions or other abnormalities which may result
in solid wastes. Until ths process is operacing efficiently, quantities of
off-quality product may be produced.
-------
Solid wastes from pilot plants are usually generated in batch rather than
In continuous quantities. The pilot plant Is normally operated Intermittently
and disassembled after It has been tested sufficiently and has been either
rejected or accepted for full-scale construction. Since the wastes are often
generated by new and unproven processes, they may be dissimilar to other process
wastes generated by the plant, and as such, may present difficult disposal
problems.
Dredging. Dredging is used for the removal of process wastes from ponds
and lagoons, to build shipping facilities, and to clear waste water drainage
channels.
Many plants are located near ship channels where it is possible to build
their own piers for handling tankers or ore barges. While the maintenance of
these berths does not bear directly on chemical process wastes, the disposal
of the dredged material Is the plant responsibility. Such disposal problems
usually arise every three or four years but can be an annual problem in some
cases.
Some plants utilize open drainage ditches and channels for the flow of
waste water through the plant. In some cases, the silt from the bottoms of
these channels is removed and used as fill. Neither dredge spoils from
construction of shipping facilities nor maintenance of drainage channels was
reported on the mail questionnaire, indicating that the plants did not consider
the material a solid waste. It should be considered as such, however, since
it is associated with the plant's operations and in many cases, presents a
difficult disposal problem.
Floor Sweepings. In the course of cleaning around process equipment,
chemicals that have leaked cr spilled from the equipment are gathered with
other dirt. The chemicals are contaminated and discarded. Often the spillage is
67
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mixed with saw dust, diatomaceous earth, or similar material to facilitate
cleaning which further Increases Its bulk.
Equipment Cleanout. Periodically, process equipment such as bucket
elevators, belts, pipe lines, and tanks, along with storage tanks and tank
trucks, are cleaned. The accumulated solids in this equipment are usually
treated as solid wastes for disposal.
Parameters Which Influence Solid Waste Generation
The quantity of solid waste generated by a particular chemical production
process Is influenced by a number of parameters related to process raw materials
and operations. Four general parameters repeatedly reported by industry personnel
as influencing solid waste generation were: total production, purity of raw
materials, efficiency of reaction, and general maintenance of process control.
The first parameter, total production, generally applies to almost all processes
since solid waste generation is proportional to production volume.
The purity of process raw materials directly affects solid waste
generation where the impurities leave the process as solid waste. The effect
on waste quantities is proportional to the percentage of impurities.
The efficiency of reactions associated with chemical processes also
directly affects the quantity of solid waste generated. In many cases, chemical
reactions are stopped before they reach equilibrium or completion, and if the
unreacted material remaining cannot be recycled, it frequently appeals as a
solid waste. Undesirable side reactions can affect the efficiency of the main
reaction, and also produce solid compounds requiring disposal.
General maintenance and attention to process operation on the part of
operators exhibits a significant effect on solid waste generation. Off-quality
product waste is a direct result of process malfunction or carelessness which
-------
can usually be avoided through proper process control. It was pointed out by
process engineers during our investigation that there are many processes where
improper attention either to maintenance or direct controls will result in
solid wastes.
For many production processes, the influencing parameters can be related
quantitatively to solid waste generation. The relationships are only valid,
however, for the particular chemical processes for which they are developed.
Since this study grouped all solid wastes into general waste categories,
meaningful quantitative relationships could not be formulated for these
categories due to the variety of production processes generating each waste type.
69
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SECTION FIVE: INDUSTRIAL CHEMICALS GENERATING SOLID WASTES
Page
Organic Chemicals 75
Coal Chemicals 75
Petrochemicals 79
Solid Waste Generation 83
Inorganic Chemicals 99
Solid Waste Generation-Alkalies and Chlorine Industry
(SIC #2812) 101
Solid Waste Generation-Indus trial Gases (SIC //2813)
Oxygen, Nitrogen, Hydrogen, and Carbon Dioxide 106
Solid Waste Generation-Inorganic Pigments (SIC #2816) 111
Solid Waste Generation-Miscellaneous Inorganic Chemicals
(SIC #2819) 119
Figures
6 Interrelationship of chemicals from natural gas, petroleum
cuts, and coal 74
7 Schematic diagram for manufacture of toluene, benzene,
and xylene from petroleum by hydroforming 82
8 Schematic diagram for manufacture of toluene, benzene,
and xylene from coal gas and tar light oil by acid
washing 84
9 Schematic diagram for manufacture of phenol by the
benzenesulfonate process 86
10 Schematic diagram for manufacture of phenol from toluene 88
11 Schematic diagram for manufacture of phthalic anhydride
from ortho-xylene 90
12 Schematic diagram for manufacture of nitrobenzene from
benzene and nitric acid 92
13 Schematic diagram for manufacture of aniline from
nitrobenzene by reduction 93
14 Schematic diagram for manufacture of toluene diisocyanate
from toluene and phosgene 94
15 Schematic diagram for manufacture of ezhyl chloride from
ethylene and hydrogen chloride 96
16 Schematic diagram for manufacture of citric acid from
molasses by fermentation 98
17 The alkalies and chlorine industry 100
18 Schematic diagram for manufacture of soda ash by the
Solvay Process 104
19 Major production process for industrial gases 108
20 Schematic diagram for manufacture of acetylene from paraffing
hydrocarbons by pyrolysis. (Wulff Process) 112
21 Schematic diagram of manufacture of acetylene from natural
gas by partial oxidation. (Sachsse Process) 113
22 Schematic diagram for manufacture of titanium dioxide from
ilmenite
Preceding page blank
71
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Figures Page
23 Schematic diagram for manufacture of titanium dioxide
from rutile by chlorination and oxidation 118
24 Schematic diagram for manufacture of alumina from bauxite
by the Bayer Process 122
25 Schematic diagram for manufacture of phosphoric acid from
phosphate rock by the wet process 128
26 Schematic diagram for manufacture of phosphoric acid and
phosphorus from phosphate rock by blast furnace 129
27 Schematic diagram for manufacture of disodium phosphate
and trisodium phosphate from phosphoric acid and sodium
carbonate 132
28 Schematic diagram for manufacture of Glauber's salt from
salt and sulfuric acid 136
29 Schematic diagram for manufacture of hydrofluoric acid
from fluorspar and sulfuric acid 138
Tables
15 Value of shipments of organic chemicals (1967)
16 Principal coal chemicals
17 U.S. production of tar crudes, 1953 and 1967
18 Raw materials and basic petrochemicals produced from
petroleum and natural gas
19 Production and sales of crude products from petroleum
and natural gas for chemical conversion, 1967
20 Production of chlorine and alkalies-1963 and 1967
21 Production of industrial gases-1963 and 1967
22 Major inorganic pigments, SIC 2816, 1963 and 1967
23 Ma-or inorganic chemicals, SIC 2819, production 1963 and
1967
24 Production of sodium phosphates-1967
76
77
78
80
81
102
109
114
120
130
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SECTION FIVE: INDUSTRIAL CHEMICALS GENERATING SOLID WASTES
Solid waste generation from general chemical processes was analyzed in
detail. In most cases, the process involved the manufacture of a major chemical
wherein significant solid wastes were generated. The information on the processes
was obtained from the plant visits and from generalized flow diagrams contained
in the literature.
It was beyond the scope of this study to attempt to identify the solid
waste potential of every chemical production process and to identify each waste.
Indeed, this would be a monumental task, for there are over a million different
chemicals with almost as many waste products. Such a study would require lengthy
and detailed waste surveys at plants manufacturing these chemicals, to which the
industry would have to donate substantial amounts of time in a chemical by
chemical analysis of waste generation. Also, the industry is changing so rapidly
that this detailed a survey would never be truly finalized. Since the need to
provide an overall view of solid waste generation, indicating in relative terms
those chemical production areas of high waste generation and those where no
solid waste is produced. General waste categories were used, based on physical
characteristics and sources, thus eliminating the need for chemical identification
of the waste which is unknown in many cases.
The following sections discuss the nature of manufacture in each four
digit SIC category, including products produced and raw materials used, and
the types and quantities of solid wastes generated. A number of specific
processes are presented as examples for the industry. The background Information
on chemical manufacture for each SIC category will be elementary to those active
in the industry, but for those interested in industrial solid wastes who are
unfamiliar with chemical industry manufacturing practice, the information
73
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NATURAL GAS
PETROLEUM
COAL
Carbon black
Acetylene
Methane
Ethylene
Propylene
Butylene
Benzene
Toluene
^ Xylene
Naphthalene
Coke
Vinyl chloride
Acrylonitrile
Acetaldehyde
Methyl alcohol
Ethyl alcohol
•- Ethyl ene oxide
Isopropyl alcohol
Ethyl benzene
Polypropylene
Butadiene
Maleic anhydride
Phenol
*-Benzaldehyde
Benzoic acid
Phthalic anhydride
Figure 6. Interrelationship of chemicals from natural gas,
petroleum cuts, and coal. (From Reference #58)
-------
is essential to an understanding of the nature and origins of the wastes.
Organic Chemicals
Major raw materials for the production of organic chemicals are the
fossil fuels: coal, petroleum, and natural gas. Many of the same basic
chemicals are derived from more than one of these fuels. The interrelationship
of chemicals from each of the three raw materials is shown in Figure 6.
Competition exists among the raw materials, with petrolexm-basei chemicals
substantially replacing coal-derived chemicals in recent years.
The important classes of synthetic organic chemicals along with their
1967 value of shipments are shown in Table 15.
Coal Chemicals. The basic raw materials for the production of coal
chemicals are derived chiefly as byproducts from the production of coke, which
is consumed primarily in the steel industry. These raw materials, therefore,
depend on the demand for steel. Coke .is produced through the destructive
distillation of coal; it is thermally pyrolyzed by heating in the absence of
air, and is converted into solid, liquid, and gaseous products. The principal
product by weight is the remaining solid, coke; the other products are water,
tar, crude light oil, gas, and gas liquor. These are the raw materials for the
production of coal chemicals, which ars the principal chemicals used as the
basis for manufacture of countless other organic chemicals. These chemicals
and their sources are listed in Table 16.
Statistics for production of the major tar crudes from coal are shown
in Table 17, along with production of the same chemicals by petroleum companies.
The table shows that in 1967, the bulk benzene, toluene, and xylene was produced
by petroleum operators, whereas, as recently as 1953, coal was the leading
precursor for benzene. Also, production of many other tar crudes has decreased
75
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TABLE 15
VALUE OF SHIPMENTS OF ORGANIC CHEMICALS
(1967)*
Product
codii
2815
28151
28152
28153
28155
a3i'»o
2818
28181
28182
;.3183
28184
28185
28180
r.«.c.',.
Cres^.esj-
Cyclic i-:it/-;s.aGdi-£.sii
Cyclic 'Ia-L-'c.-r^.r;.;>-.
Synthetic orgai^ic
Synthetic OiCgi.r.iT
and tonsrc
Cyclic-. {'re;.-;.;?. ':r:r)
Cyclic ir.t'i ri^- . ' » .
• r „ e „ k ..
Induetria.3. organic
MtsceXIsi^otJCi. :•?--.
prater;*.
mocel.c.-.iOL : .-.:y
axid .:;;? evr.'. "• -•.'. y
?yt:^;-: , ::•.., v...
Total shipments
group including interplant
transfers (millions)
of dollars)
;) and crudes 1 ,650
.taa 1,070
dyes 325
" pigments 9 lakes ,
162
: r;?*(i'i^a 88
\" -'"**4 G*t /"I ^»"J~llH £*Q
1- L> -b^.U ^.JL l£UG«D ^
13
chamicalss n.e.c. 5,540
l^.c chemical
315
clic chemicals
rrcdncte 4,050
•-j;ru:ics.isi n.e.c. ' 586
Pesticides and other organic chemicals
(not fortnulr-.'ii
Ethyl alcohol and
organic chspii^
Iadt:a£Tir.'. afg.^i:
n o a . k . .
not els^w'iX" c.' ;^;- . ' •'•.
ons) 308
other industrial
als , n«e.c. ' 239
3 chemicals 9 n^e.c.,
39
n-c>k, -.not specified by kind
*Frotn Reference #680
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TABLE 16
PRINCIPAL COAL CHEMICALS*
From
Gas
From
Gas Liquor
From
Light Oils
From
Tar
From
Coke
Carbon monoxide Pyridine tar bases Carbon disulfide
Hydrogen sulflde Ammonia liquor Cyclopentadiene
Hydrogen cyanide Ammonium sulfate
Hydrogen
Ammonia
Nitrogen
Carbolic oil
• Phenols
Creosols
Xylenols
Water gas
Methyl alcohol
Ammonia
Graphite
Benzene
Xylene
Pyridine tar bases. Naphthalene Calcium carbide
Crude naphthas Creosote oil Calcium cyanamid
Toluene Anthracene
Refined tar
Pitch
77
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'TABLE 17
U.S. PRODUCTION OF.TAR CRUDES, 1953 AND 1967*
Product
Unit of.
quantity
Production Production
1967 1953
Crude light oil; Coke-s>vea
operators
Intermediate
Coke-oven
light oil ?
operators
1S000 gal
1,000 gal
252,000 304,000
5,560 1,060
Light oil "distillates i
Benzene, specification end
industrial gradess total 1S000 gal 969,000 273,000
Coke-oven operators 1S000 gal 90,600 178,000
Petroleum operators 1,000 gal 879,000 63,000
Toluene, all gradess total** 19000 gal 644,000 :156,000
Coke-oven operaf.ojrn 1S000 gal 19,400 36,000
Petroleum opsrs.t6i:3 ' 1,000 'gal 624,000 115,000
Xyletie, all grades,, toii&iV^ 1,000 gal 455,000 113,000
Coke-oven operators 1,000 gal 5,490 9,930
Petroleum op«?;ai:ptB 1S000 gal 449,000 103,000
Solvent naphtha.
Coka-oven bparaeora 1,000 gal 3,630 6,280
All other light oil distillates,,
total 1,000 gal 10,700 14,700
Coke-oven operators 1,000 gal 8,400 6,100
Tar distillers^* 1,000 gal 2,280 8,560
Naphthalene, crude (?.ar distil} ,ss.*3 '
and cqke-oveft oparr'^ora} s
total**** 1S000 Ib 521,000 276,000
Reference
'-^Includes data for icat«irisJ. produced for use in .blending motor fuels.
***Includes solvent napbaha and xtibber-reclaiming oils. •
****Statiatics represent combined 'data for the commercial grades of
naphthalene .
Because of convcaxsiou of inaptitib^iiene from one grade to another,, the figures
may include some duplication <,
-------
since 1953. Other miscellaneous coal tar chemicals, such as dyes, intermediates,
medicinals, flavors, perfumes, resins, rubber chemicals, and many more are
also increasingly being taken over by petroleum-based chemicals.
Petrochemicals. Petrochemicals are basic chemicals derived from the
raw materials petroleum and natural gas. It has been estimated that more than
80 percent of the organic chemicals of the entire chemical industry are based
on petrochemicals, with nearly 10 percent of the sulfur and most of the carbon
derived from natural gas or petroleum products. The basic raw materials for
petrochemicals supplied by petroleum refineries or natural gas companies are
liquid petroleum gas (LPG), natural gas, gas from cracking processes, liquid:
distillate, and distillates from special cracking processes, as well as
cyclic fractions for aromatics. : These raw materials are separated from
petroleum, usually within the petroleum refinery, by ,a wide range of physical
processes. The raw materials are then chemically converted into the reactive
precursors used in the manufacture of various industrial chemicals. Nearly all •
the petrochemicals are produced through reactions involving many chemical
conversions. Most often, these chemical reactions are involved and completed,
developed through the research and development efforts of the individual chemical
companies.
The major organic raw materials obtained from petroleum and natural gas
for the manufacture of petrochmicals are listed in Table 18, along with their
associated basic chemicals, intermediates, and final finished products. This
listing represents only a small portion of the great number of organic chemical
intermediates and products produced from petrochemicals.
Total production of crude products from petroleum and natural gas for
chemical conversion was 54.4 billion pounds in 1967, representing $858 million
in sales as shown in Table 19.
79
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TABLE 18
Haw materials
••y distillation
t ^x af fins and
aiural gas
ol fides
/drogen
finery gases
..finery naphthas
-...phthenes
Tylenes
naph thanes
SAW MATERIALS AND BASIC PETROCHEMICALS
D FROM PETROLEUM AND NATURAL GAS*
Basic chemicals
by cr,rwa i' s ion
Intermediates
by conversion
Finished products.
by conversion
Clef:?»-.£; -v :!* *?j.a3 Various inorganics
sc-^'cy; e:;'i:, ^;-:o'-aafc±cs and organics
Hydrogen
Acetylene
Etby'ic,.'.
ene
Sulfur
Synthesis gas
Acetic acid
Acetic anhydride
Isoprene
E'r.hylene oxide, etc,
Butadiene
Adipic acid
Ethybenzene
Si.yrene
Cuscene
Alky Ib enz ene
Cyclohexane
Phenol
Benzoic acid
Phthalic anhydride
Phthalic anhydride
Inorganics and
organics
Carbon black
Sulfuric acid
Ammonia
Methanol
Formaldehyde
Acetates
Fibers
Rubber
Rubber and fiber
Rubber
Fibers
Styrene
Rubber
Phenol
acetone
Plastics
Plastics
Plastics
Reference #58.
LPG and refinery crackaci g'as. Motes Aromatics are also o.btained by chemical
conversions
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TABLE 19
PRODUCTION AND SALES OF CRUDE PRODUCTS FROM PETROLEUM AND NATURAL GAS
FOR CHEMICAL CONVERSION, 1967*
Production Sales
Product (in 1,000 pounds) (in $1,000)
Grand total 54,438,000 858.000
AROMATICS and NAPHTHENES**
Total ............. 55.000 267,000
Benzene (1° and 2°) total..... 6,485,000 114,000
Naphthalene, all. grades....... 377,000 13,800
Naphthenic acids, total. 24,000 1,300
Toluene, all grades, total.... 4,540,000 68,200
Xylenes, mixed, total.... 3,240,000 48,600
All other aromatics and naphthenes*** 1,790,000 20,300
ALIPHATIC HYDROCARBONS
Total... 54,383,000 591.000
C-7 Hydrocarbons, total. 13,841,000
Acetylene****................ 429,000 •
Ethane 1,557,000 7,000
Ethylene ........ ... 11,854,000 133,000
C-3 Hydrocarbons, total...... 10,513,000 115,000
C-4 Hydrocarbons, total 8,226,000 232,000
C-5 Hydrocarbons,,total...... 784,000 6,200
All other aliphatic hydrocarbons
and derivatives, total.... 4,618,000 98,600
*From Reference #71.
**The chemical raw materials designated as aromatics are, in some cases,
identical with those,obtained from the distillation of coal tar; however,
the statistics given in the table above relate only to such materials as are
derived from petroleum, and natural gas. Statistics on aromatic chemicals
from all sources are given in Table 3 of the Preliminary Report, "Tar and
Tar Crudes, 1967", U.S. Tariff Commission.
***Includes data for 90 percent benzene, crude cresylic acid, crude
carbolate and phenate, slkyl aromatics, distillates, solvents, and
miscellaneous cyclic hydrocarbons.
****Prpduction figures on acetylene from calcium carbide for chemical
synthesis are collected by the U.S. Bureau of the Census.
81
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cs
N)
} I \\-Lfjr Oil-
L
~eed stock t-^ 1 «
r ••• • — <^- Piiyna/^B — J Qaaffrnv* • — uac . .• , ._., ,r— 9"h^hii 1 i 71
naohths^ ^ rurr!clLL - -i -•!-«^l-J' : oi-auiiizi
L ^ ' ; I , 1 spparaf-nr column
1'
Hydrofcrmste ?
1 (.
. - .-,„—, Toluene _..:._. .., ,, • . ,^_^^.- , • . Aoluene
* MEK" '^- ',„, ^|MIT,!!C ••
up— •— — •"•— column
Flash _ Crude Azeotr.ope
tower toluene column
1
.Sulfuric .Caustic JL ,„.
acid — j Fsoda water JSaSSLtlo
j 44
ui - ' J
rtixer ana : 1 Kptnnp
washer . - Refining - eecoverv
culul11" olant
ng
. |L.0Fuel gas .
"" {butenes)
-— O G ~- sol ins
~1
| H^Xylene
MEK - water
Tars to 'A \
primary '?•• ^.
column Nonaromatics
Toluene
Figure 7. Schematic diagram for manufacture of toluene, benzene, and xylene from
petroleum by hydroforming. (From Reference #58)
-------
Solid Waste Generation. The organic chemical industry is divided into
two SIC categories: 2815; cyclic intermediates, dyes, organic pigments (lakes
and toners), and cyclic crudes; and 2818: organic chemicals, riot elsewhere
classified. The four process waste categories directly associated with chemical
processing (sludges, tars, filters residues, and off-quality product) are
generated by organic chemical manufacture.
Toluene, Benzene, Xylerie. Two organic raw materials, coal and oil,
are important to solid waste generation only in that they are used
directly to produce the primary organic chemicals as shown in Figure 6. - In
most cases, the production of the primary organic chemicals from petroleum
results in little or no solid wastes as they are produced mainly during the
refinery process, whereas coal chemical production does generate significant
solid-waste quantities. For example, toluene,-benzene, and xylene can be
produced by catalytic reforming (hydroforming) of petroleum or by fractional
distillation of coal tar light oil. The two processes are shown in Figures
7 and 8.
The hydroformirig process shows no significant sources of solid wastes.
During the process, various other products and byproducts are produced such
as gasoline, fuel gas, and nonaromatics, all of which can be used or recycled
(such as the gases from the gas separator and tars' from the refining column)
back into the process.
The process using coal light oil generates sludges and tars as wastes.
In this process, light oil from coal carbonization gases containing the crude
products are refined by distillation and washing with sulfuric acid. The
procedures vary from plant to plant, but the normal processing steps are shown
on Figure 8. First the crude benzene, toluene, and naphthas are separated from
the light oil by a vacuum still. This oil contains the crude products and is
83
-------
oil
as-
r-J Vacuum
sti]1 :
5 , t
i Crude !
i . . __. j
! psru^ta- I
Cn*d£
i
I
Cruds
naphtha
i
g-j , —
Heavy
solvent
Ifeter - Sodi IKJ
jhydvoxide
Middle \
oil -*'•«•'-
- vi
Was
tar
nr ~~ . .^ fr
(,•• Wastes^_,f ] _ M , M , .
aC lu ^~^ • I
^ sludge 1 (t
' J
Washed
I
^ Fractionatinq ^ uon^one
\ column m loiuene
ly
^R ^^ y\/lonp
HCnT won't"
naphtha
iNwaSlA:
•^sludge
Figure 8.. Schematic diagram for manufacture of toluene, benzene, and xylene
from coal gas and tar light oil by acid: washing. (From. Reference ..#26)
-------
washed to remove the sulfur compounds, nitrogen bases, and unsaturated compounds.
The oil is first washed with sulfuric acid to dehydrate it.. It is then washed
one or more times with larger quantities of acid, which result in a thick,
black, acid sludge which is drawn off and sent to disposal or recovery
operations. The oil is then neutralized with a sodium hydroxide solution, again
resulting in a sludge. Loss of light oil during washing has been reported as
4 to 6 percent by volume. The acid-washed oil is distilled into benzene, toluene,
xylene, and solvent naphtha. Part of the distillation residue is reclaimed as
middle oil, and the other portion is disposed of as waste tars.
Benzene, toluene; and xylene are three of the most important and basic
organic chemicals .from which many chemicals are produced. In some cases, they
generate significant quantities of solid wastes.
Phenol. Phenol is .one of the most important aromatic chemicals, and is
synthesized from berzene or toluene. Phenolic resins consume 50 percent of
phenol production. About 30 percent of the remainder is used for production
of caprolactam, which is used in the manufacture of synthetic fibers (expecially
nylon 6) and. plastics, and in bisphenol A, used in the manufacture of epoxy
and polycarbonate resins. In 1967 total synthetic phenol demand was 1,300
million pounds. This figure is expected to reach 1,800 million pounds by 1970.(46)
Phenol does occur naturally in coal tar, but extraction from this source'
is declining in importance. There are six major processes used for the production
of synthetic phenol, all of which generate high boiling waste tars or substantial
quantities of byproducts or both. The major process in use is ,the cumene
peroxidation process developed by Hercules which produced 56 percent of the
phenol in 1967. In this process, cumene obtained from benzene is oxidized to
form phenol and acetone, a -readily salable byproduct.
The chlorobenzeine (caustic) process converts benzene into the sulfonic
85
-------
Benzene =-
., . Sulfuric
Vaporizer -, ac1d
a v
=-[> Lcr-.8enzena~-<=| Sulfonator „_ Neutral"!
fT • \ '^ tank
El3 _ -- J f '
"~~~ sulf'te • " !-' dio;dde
r \/
I _
Recovered p^^ Acidlfier- ~~
sodiun sulfite | -
sludge I
I—
j~~ iiteam
V- still
Crystal lizer |.
4 Dilute
Sodium sulfite phenol
by-product wash
water
Sodium
^sulfate
1 by-product
zing =- — cr= -Filter
f
i!' ' Ca
'i ;^ so
('' \'
Fusion =:?
not
^ Vacuum o
col umn
Waste
tar
ustlc
da
Water
J '
Water
1
Figure 9. Schematic diagram f.or manufacture of phenol by the benzenesulfonate
process. (From Reference, #26)
-------
acid and fuses the latter with caustic soda. The sulfonate is treated with
acid, liberating phenol which is then distilled off. The last distillation
column yields a residue of diphenyloxide which was a waste when the process
was first instituted. Today, however, a market has been developed and all
can-be sold.
In,the benzene sulfonate process shown in Figure 9, benzenesulfonic
acid is prepared in a sulfonator by the action of concentrated sulfuric acid on
benzene. After sulfonation, the product is added rapidly to a neutralizing
tank containing a solution of sodium sulfite or sodium carbonate. The
neutralization tank yields sodium sulfate (which precipitates out and is filtered
from the solution) and sodium benzenesulfonate liquor which is pumped to a
fusion pot. The pot, charged with fused caustic soda, yields sodium phenate,
sodium hydroxide, and sodium sulfate in solution. The solution is acidified
with sulfur dioxide, liberating phenol as an upper layer over an aqueous solution
of sodium sulfite ard sodium sulfate. The phenol is refined by distillation,
yielding a waste tfcr consisting of impurities. The sodium sulfite and sodium
sulfate are byproducts which .can usually be sold.
The regenerative (Raschig) process produces phenol from benzene and
hydrogen chloride. Like the benzenesulfonate process, a waste tar consisting
of high boiling materials is generated from the final refining column.
In a recent process developed by Dow Chemical Co. shown in Figure 10,
toluene is used as the starting material. This process is said to yield a
minimum of byproducts and waste materials. The process operates through oxidation
of toluene tc benzole acid, its conversion over copper catalyst to phenylbenzoate,
and hydrolysis to phenol. What waste tar'the process does produce is generated
from an extractor. The .extractor is used to purge the unwanted tars and recover
chemical and steam values from the reaction mass which is periodically withdrawn
87
-------
Inerts vent
Air-
Catalyst'
Toluene
feed
Inerts
R<
3actor !-,, Decanter ••%• &•
.-.is-x/is. — , Toluene
?
Absorber
reeve 10 r — •„.
.1
r
i r
*» Still
lO
jl
1
Wastes
c=>Pure benzole acid
i'teoic acit! feed
0
Catalyst•
l>
Reactor
Sie
Extract^
•Water
Waste
tars
Phenol,
Waters
benzoic acid
Benzoic acid
and aromatics
Phenol
Still
Crude
phenol
Benzoic
acid recycle
(unreacted
benzoic acid)
Figure 10. Schematic diagram for manufacture of phenol from toluene. (From Reference #48)
-------
from the reactor.
Phthalic Anhydride. Phthalic anhydride Is a derivative of xylene and
its production is a significant waste generator. It may be produced from air
oxidation of ortho-xylene as shown in Figure 11. A mixture of vaporized
ortho-xylene and preheated air is fed into a reactor, where under the
influence of vanadium pentoxide, a catalyst, the main reaction takes place
as follows:
ortho-xylene + oxygen = phthalic anhydride + water
The reactor gases containing the phthalic anhydride are cooled,
crystallized, and reuelted to form the crude product, which is approximately
99 percent phthalic anhydride. The residual impurities are removed in a
column under vacuum. The residue is a waste tar which is a brittle solid at
room temperature.
Another major process for production of phthalic anhydride uses
naphthalene as the f^ed stock in a very similar process. Again a brittle
tar waste is generated at the final purification columns. This process using
napththalene accounted for just over 50 percent of the total production of
727 million pounds in 1967.(71) Plasticizers and resins are the major uses
for this chemical.
Nitrobenzene. Nitrobenzene is derived directly from benzene. It is
primarily used for the production of aniline which consumes 90 percent of its
production; the remainder'is used for benzidine and solvent dinitrobenzene
manufacture. In 1967, 347 million pounds of nitrobenzene were produced with
a 5 percent per year growth rate predicted through 1972.(46,71)
89
-------
-o
o
Ortho-xyVene
Vaporizer
Mixer
Preheater
Filter
Stack gases
Vapor
cooler
_. Condenser
box
j
1
Flaker
t
Phth
anlry
-=— -e=
!*
al i c
dride
tank
j
Col umn
Haste
tars
Figure 11. Schematic diagram .for manufacture of phthalic anhydride from ortho-rxylene.
(From Reference //26)
-------
The production process as shown In Figure 12 utilizes a nitric acid-aulfuric
acid mixture to nitrate benzene. Crude nitrobenzene is separated from the spent
acid, washed with dilute sodium carbonate, and refined in a. distillation column.
The residue from this final distillation process is a waste tar. Crude
nitrobenzene is extracted from the process before refining for use in aniline
production.
Aniline. Aniline is one of the most important organic bases. It is a
poisonous oily liquid, 65 percent of which is used in the manufacture of rubber
chemicals and 25 percent In dyes, intermediates, and drug and pharmaceutical
production. In 1967, production was 112,778 short tons, and growth is predicted
at 6 percent per year through 1973.(46,71)
Production of aniline generates waste tars from the final distillation
process for recovery of the chemical that are similar to those of nitrobenzene
production. The process using crude nitrobenzene shown in Figure 13 operates
through reduction of the nitrobenzene with iron filings or borings with 30 ,
percent hydrochloric acid as a catalyst. Crude nitrobenzene, iron borings,
and hydrocholoric acid are fed to a reactor where the main reaction takes place
nitrobenzene -t- iron + water = aniline + ferric oxide
The ferric oxide comes out of the reactor as a sludge for disposal or
possible recovery. The sludge is sometimes sold to steel mills for use as a
substitute for iron ore. In the final distillation column, a residual waste
tar is generated and discarded.
Isocyanates. I-socyanate production generates tar wastes as the result
of polymerization and distillation. The organic isqcyanates are compounds in
which the isocyanate group, NCO, Is attached to an organic radical. They react
readily with a great variety of organic compounds and may also react with
91
-------
Nitric acid
Benzene
Sulfuric
acid — — "i>
Mixer
— «=• Mixed"
Nitrator
Separator
~f~
Spent
acid to
recovery
Cruae
nitrobenzene
Jo aniline
production
Water, dilute
sodium carbonate
- Masher
IV
If
{?
•
Column
Wash-water
waste
Waste
tar
Nitrobenzene
(refined)
Figure 12. Schematic diagram for manufacture of nitrobenzene from benzene and
nitric acid. (From Reference #26)
-------
Catalyst
Iron hydrochloric
borings
Crude
nitrobenzene
UJ
Reactor
Waste
sludge
(mostly
Fe3041
cid
Cooler and
separator
1
— — »
Column
Aniline waters-
13. Schematic diagram for manufacture of aniline from nitrobenzene
by reduction. (From Reference #26)
-------
Phosgene
COClo
H>
Cold.
phqsgenatdr
0-60 °C
Toluene
diAmine
solution
J
Hot
phosgenators
100-200 °C
Solvent.
Vapor
Separation
OD
1
HC1 to adsorption
to recovery
TO I product
TDI -..
recycle
Fractionating columns
(&)
Residue
waste
Figure 14. Schematic-diagram for. manufacture, of,toluene diisocyanate from toluene
and phosgene. (Front Reference //36)
-------
•themselves. The manufacture of flexible urethane foam utilizes 50 percent of
the isocyanates produced, with rigid foam consuming 23 percent, and coatings
and elastomers 5 percent. They have been an extremely rapid growth group of
chemicals, at 38 percent per year from 1957 to 1967, .and with future growth
predicted at 10 percent per year through 1972. In 1967 production of isocyanates
was 250 million pounds. Production is predicted to be 400 million pounds by
1972.(46)
Toluene diisocyanate is one of the major isocyanates, and is produced
from toluene derivatives and phosgene as shown in Figure 14. In .this process,
toluene diamine is produced by the successive nitration of toluene with mixed
nitric" and sulfuric acids. The toluene diamine, along with, an aromatic solvent
.such as xylene, monochlorobenzene, or orthene, is mixed with phosgene containing
the same solvent. This reaction mixture is digested in one to three stages
at progressively higher'temperatures with the injection of additional phosgene,
The resultant solution is .fractionated to recover hydrogen chloride, unreacted
phosgene, solvent, and the product toluene diisocyanate (TDI).., In the last
fractionating column, the remaining TDI is recovered and recycled back to the
second fractionating column leaving a waste distillation residue.
Ethyl Chloride. Ethylene-based chemical operations can generate a
variety of wastes. Sludges, tars, and filter residues were all reported in the
survey as wastes from these operations. An example of an ethylene-based process
is the production of ethyl chloride from ethylene and hydrogen chloride. Ethyl
chloride .is used mainly for production of tetraethyl lead with 675 million
pounds produced in 1968.(46)
The process, as shown in Figure 15, brings ethylene gas and anhydrous
hydrogen chloride together in approximately equimolecular proportions. The
mixture is passed into a reactor containing ethylene dichloride or a mixture
95
-------
Aluminum
chloride
Catalyst
Ethylene
gas _
Hydrogen
chloride
Ethylene
dichloride
Mixer
Reactor
Sppt
catalyst
waste
Ethyl
chloride
Separator
Fractionating
column
©
Waste
tars
Polymer
bottoms
to recovery
or waste
Figure 15. Schematic diagram for manufacture of ethyl chloride from ethylene
and hydrogen chloride. (From Reference #26)
-------
of ethyl chloride and ethylene dichloride. The hydrochlorinatipn reaction
takes place in the presence of a catalyst, aluminum chloride. The catalyst
is continually withdrawn and new makeup catalyst added with some of the spent
catalyst discarded. The reactor products are fed into a separator where the
lower boiling ethyl chloride is separated from the heavier polymers -which are
drawn off and either partially recovered or wasted. .The crude ethyl chloride
is further refined by fractionation, removing other high boiling organics to
waste.
Chloral. A waste sludge is generated from chloral production from
ethyl alcohol by chlorination. Chloral is used chiefly in the production of
DDT. Ethyl alcohol is first chlorinated, during which ethyl chloride is obtained
aa a byproduct.. The chlorinated mixture consists of 'chloral hydrate and chloral
hemiacetal. It is mixed with sulfuric acid to decompose the acetal. The
mixture is then distilled and the chloral cut taken off. The resultant crude
or technical-grade chloral may be used directly in the manufacture of DDT, or
it may be further refined.. The refining procedure uses calcium carbonate to
remove the remaining traces of acid. A waste sludge of calcium sulfate is
formed and drawn off to disposal.
Citric Acid. Organic chemicals from other than coal or oil derivatives
can also generate solid waste. Citric acid is an organic acid, produced from
sugar, whose production generates solid waste. Its uses include: beverages,
60 percent; Pharmaceuticals, 18 percent; arid sodium salts and esters, 10 percent.(46)
Mycological fermentation of carbohydrates is the most important commercial
source of citric acid. It also occurs naturally in citrus fruits and pineapple,
from which it is sometimes recovered. The mycological processes are complicated
fermentation processes where the factors governing citric acid accumulation
are .controlled to obtain maximum yields.
97
-------
o
D
•Water— *
Acidl FMold r«'
Moiasses^ } • \ - v
gj= A
Mi YOV* ;— J-PS: Fo»*fn*»n't'a1"i nn ^ptt"! i nn
a, . . A. ^^ chamber tank
Nutrient
Waste
mycel i urn
sludge
IT- Charcoal
I
. sz\ Filter =a-=— — — =» Purifier =^=— -
Spewt^ —
charcoal
i
{Lime water
^
Pypp-i ni-f atnr _— j— Fl
"^^ and separator
4
Calcium
oxalate
SulfuHc — — "C^j Acic
aciQ *
- — — Evaporator =c Fi
__- — , rir>\^f%p .t^*i n~t~Y
•|4.pr
o
Waste
liquid
"
lulator
t -'
Iter — ^k
WKte-
calcium
sulfate
%ic acid
Mother liquor
to recycle
Figure 16. Schematic diagram" for' manufacture of citric acid from molasses by
fermentation. (From Reference #26)
-------
The process as shown in Figure 16 uses a molasses to supply the necessary
carbohydrates, water, acid, and a nutrient to which a mold is added to induce
fermentation. The mixture is retained in the fermentation chamber until
sufficient mycelium has formed. The solution is withdrawn from the chamber,
and the mycelium settled out, washed, and filtered to remove residual'adhering
citric acid. Calcium hydroxide is added to neutralize the solution, and the
calcium citrate is filtered off and washed to remove adherent residual sugar,
polysaccharides, and nitrogenous constituents. The filtrate, a liquid waste,
is sent to disposal. The calcium citrate is sent to an acidulation tank where
a slight excess of sulfuric acid is added. This combination forms dilute
citric acid and calcium sulfate. The calcium sulfate is filtered off and
washed on a filter. The dilute citric acid is purified by decolorization and
demlneralization. This process involves treatment with activated carbon followed
by final filtration. The carbon is either wasted or reactivated and returned
to the process. The solution is then crystallized and the mother liquor removed
and returned to the process. The solid wastes from this process are the mycelium
removed as a filter cake, the hydrated calcium sulfate also removed as a filter
cake, and occasionally the spent carbon. Ergosterol has been obtained commercially
from the mycelium, but it still remains of little commercial value.' An additional
filter cake waste associated with this process is generated from the purification
of the syrup used as the raw material.
Inorganic Chemicals
Unlike, organic chemicals, whose primary derivation is from two basic
raw materials, coal and oil, inorganic chemicals are derived from numerous raw
materials, including atmospheric gases, minerals,[water, and other inorganic
matter. The major raw materials of this industry'are listed below:
99
-------
Limestone
.and fuel
Ammonia
Carbon
dioxide
Electrolytic
process
Chlorine
Pulp and paper
Solvents
Plastics
Pesticides
Sanitation
Antifreeze and
, antiknock compounds
Refrigeration fluidr
Various chemicals
Caustic
soda ,
Soap
Rayon
Dyes
Paper
Drugs
Foods
Rubber
Textiles '
Chemicals
Bleaching
Metallurgy
Petroleum
Sodium
chloride
Sodium
bicarbonate
Soap
61 ass
Drugs
Paper
Sugar
Foods
Dyes
Shellac
Cerami cs
Textiles
Metallurgy
Chemicals
Petroleum
Photography
Leather
Agriculture
Water softening
Illuminating gas
Drugs ,
Medicines
Beverages
Baking powder
Food products
Fire extinguishers
Figure 17. The alkalies and chlorine industry. (From Reference #58)
inn
-------
NON-METALS METALS
Limestone Salt Lead Chromium
Sulfur Sand Zinc Manganese
Phosphorus Clays Copper Lithium
Air Water Iron Aluminum
Boron Other ores
The industry has been divided into four categories: alkalies and
chlorine (SIC #2812), industrial gases (SIC #2813), inorganic pigments (SIC
#2816), and miscellaneous inorganic chemicals N.E.C. (SIC #2819). These
categories include some of the very largest production chemicals such as ammonia,
chlorine, and sulfuric acid. The numbers of different chemicals within thfe
industry are not as great as the number encompassed by the organic industry,
however;" there are only 30,000 inorganics vs. about one million organic compounds.
Solid Waste Generation-Alkalies and Chlorine Industry (SIC #2812). This
industry, although it contains relatively few chemicals, is one of the most
impprtant, producing many of the basic chemicals used in the manufacture of
many other industrial chemicals and allied products. In terms of dollar value,
these chemicals rank near the top of all the inorganic chemicals.
The major raw materials used in the industry are shown in Figure 17,
along with the four most important chemicals-chlorine, caustic soda, soda ash,
and sodium.bicarbonate-and some of the important products requiring these
chemicals for manufacture. Production of the important chemicals is shown in
Table 20.
Soda Ash and Sodium Bicarbonate. Soda ash and sodium bicarbonate are the
two most important chemicals of this group in terms of solid waste generation.
Both chemicals are produced together, in the same process, with soda ash obtained
fromi the,bicarbonate in a final calcining step. Soda ash has by far the largest
101
-------
TABLE 20
PRODUCTION OF CHLORINE AND ALKALIES-1963 AND 1967*
Chemical
Production
Short tons
1963
1967
Chlorine (gas and liquid)
Caustic soda (sodium hydroxide)
Soda ash (sodium carbonate)**
Sodium bicarbonate
Potassium hydroxide
8,380,000
5,810,000
4,460,000
108,000
130,000
11,600,000
7,920,000
4,700,000
128,000
175,000
*From Reference #65=
**Not including natural soda ash.
-------
volume of the two with 6,400,000 tons produced in 1966 and 7,160,000 tons
predicted for 1970. Its growth rate was 3.1 percent per year from 1955 to
1965, and was expected to continue at 3 percent through 1970. Uses include:
glass manufacture, 44 percent; chemicals, 25 percent; pulp and paper, 9 percent;
along with soap and detergents, aluminum, and water treatment.(46) It is probable
that future increases in demand for this chemical will be met by natural soda
ash, since costs for construction of synthesizing plants are high and the last
synthesis plant was built in 1934.
Sodium bicarbonate production was 128,000 tons in 1967, growing at a
rate of only 2.3 percent from 1956 to 1966. Its uses include the food industry,
40 percent; chemicals, 14 percent; and pharmaceuticals, 13 percent.(46)
Two sources of these chemicals exist: from natural deposits and brines,
particularly in California and Wyoming, and from the Solvay or ammonia-soda
process, which is the major source today.
The Solvay process generates large volumes of solid wastes. A flow chart
for this process is shown in Figure 18. An almost saturated sodium chloride
solution, which is usually taken from underground salt deposits, is the source
of salt for the process. Sea water contains too many impurities and is seldom
used. The brine is first purified by adding lime or soda ash to precipitate
calcium carbonate, magnesium carbonate and hydroxide, and iron hydroxide.
Settling vats remove the precipitates, which are sent to waste disposal. The
clarified brine flows to a strong ammonia absorber where it takes up the
necessary ammonia. The ammonia acts as a catalyst throughout the process.
The ammonia-brine solution flows to a c&rbonating tower containing rich carbon
dioxide gas. The carbon dioxide is obtained from a lime kiln which calcines
limestone mixed with coke. In the carbonator, aqueous ammonium hydroxide reacts
with the carbon dioxide to form ammonium carbonate, and then with water to form
103
-------
Brine
well
Srine
purification
., Ammonia
(to puriflnr ?"st••.•;}
2NaHCQ3+ Heat
— Na2C03+C02+ Heat
Impurities in limestone(sands,MgC03)
purification wastes(CaC03,MgC03>Mg(OH)2)
o waste disposal beds
Figure-IB1. Schematic diagram for manufacture of soda ash by the Solvay Process.
-------
ammonium bicarbonate. The ammonium bicarbonate reacts with sodium chloride brine
to form ammonium chloride and sodium bicarbonate. This is a liquid-gas absorption
with the precipitation of the sodium bicarbonate. The crude sodium bicarbonate
xv removed by vacuum filtration and washed on a drum to remove salt and ammonium
chloride. The washed sodium bicarbonate can either be sold directly or calcined
to obtain soda ash. The liquor from the bicarbonate vacuum filter is fed to a
strong ammonia liquor still for ammonia recover.
The economical operation of the Solvay process depends upon the efficiency
of ammonia recovery. At any time the value of the ammonia in the system is
several times the value of the soda ash produced. Milk of lime is added to
the ammonia still to free the ammonia. The ammonia-free liquor contains about
50 g/liter of residual and unreacted sodium chloride, along with some of the
formed calcium chloride and some calcium carbonate in suspension. The mixture
is sent to the waste disposal area.
The milk of lime is obtained from the lime kiln after the impurities
have been removed by the slaker. These impurities are mainly those existing
in the original limestone, and consist of sands and magnesium carbonate. This
source generates the largest volume of waste from the process, with the amount
depending on the purity of the limestone used.
All of these wastes, from the lime slaker, the ammonia still, and brine
purification, are slurries containing suspended solids. The wastes are usually
sent to large diked waste beds where the solids settle out and the clarified
liquor overflows to a water body. As the diked areas fill up with solids, they
are abandoned and new ones used.
Chlorine and Caustic Soda. Chlorine and caustic soda (sodium hydroxide)
are both produced from salt solution by electrolysis. The process usually employs
diaphragm or mercury cells where chlorine is liberated at the anode and caustic
105
-------
soda at the carthode. Chlorine is a very important basic chemical, with 53
percent of production going to orgaM-c chemical and 12 percent to Inorganic
chemical mffimfacture, Ths cellar large use is for disinfection in the water
treatment aad sewage.: treatment fields«
Production of chlorine in 1867 x«ras 7»5 million tons, and the growth
rate should be at 7 percent per year through 1971. The largest portion of caustic
soda. (40 percent) is also ussd in the manufacture of other chemicals. Production
in 1967 Was 7.7 -million cons ,,/it'h a predicted growth rate of 5 percent per
year through 1971,(46)
Chemical solid wastes from ths electrolytic process itself are not
significanto A small amour.: results from salt solutio'n purification. The
j
diaphragm callsD howevers irast be dismantled periodically for diaphragm
rei 1-^siienfe-o This is a got,-; ^sample of solid wastes resulting from necessary
equij;.'V.a'»it. rsplacement in wbich the parts cannot be salvaged. _ The diaphragm
ce3lo ass composed of concrete slabs in a roughly cubical arrangement. The
cells contain a porous asbestos diaphragm £o separate the anode from the cathode.
Thl.• j'.i^hrEQsa allots XOHB iv pass through1 by .electrical migration, but reduces
diffusion of products Diaph^agLiis bscome clogged with use, as indicated by
hlg;i.av vclr.age and iiyd/:o&t^-.j_c pressure on brine feed, and must be replaced
every IOC Co 200 'days. Ths anodes are grsphits plates, and the cathodes are
crimped bt.c:a", wire. The cpar;.,: graphite plates are sold'to salvage, and the
cathodes Q,-,>:Q oiefeor oa.lv£S3d or discarded „ Th® concrete slabs ^ the body of the '
cell, are teipeei isi piles en lar.dc, In many casess they, have been used as rip-rap
on river beakso
SulM Wasfee Qaasra/c/.ou-"lad^atrial Gapeo_. (SIC #2813) Oxygen, Nitrogen,
Hydrogen, aad Cagbpa Dioscidao Indust'srial'gases have many applications, 'from
essential ia^reaisats ±x. ••-'<<.*. iumr.-afact:i£rs of o£^aer chemicals' to- food additives.
Oxygen, nit"rogon9 .'aad siyd-.rage-.a ara the £bT®s sost important gases used as raw
-------
materials for other chemicals. Nitrogen is also used to preserve the flavor of
packaged foods and for refrigerated transport. One of the fastest growing uses
of these gases is in cryogenics, which is the production and use of extreme
cold at the range of temperatures below -150 F. Oxygen is finding new areas
of application in pollution control, such as increasing combustion efficiency
and treatment of waste water.
The predominant raw materials used for production of industrial gases
are natural gas and atmospheric air. An outline of the processes used to obtain
the gases is shown in Figure 19. Carbon dioxide is produced from burning natural
gas, or in some cases fuel oil or coke, and by extracting the carbon dioxide from
the flue gases. It is also produced as a byproduct from fermentation and lime kila
operations. Natural gas is used to produce acetylene by pyrolysis through either
partial oxidation, thermal cracking, or electric arc methods. Acetylene
is also produced from the reaction of calcium carbide with water.
A variety of methods exist for production of hydrogen. The most prominent
is steam-hydrocarbon reforming of natural gas. The air separation plant is the
main source of oxygen, nitrogen, and the rare gases. The principal gas produced
is oxygen, the highest volume industrial gas. Nitrogen is actually a byproduct
of oxygen production, and the rare gases of argon, helium, neon, xenon, and
krypton are obtained by side rectification columns from takeoffs at various
points in the air separation process. The quantities of the major industrial
gases produced in 1963 and 1967 are shown in Table 21.
Oxygen is produced both as lower purity or tonnage oxygen (95 percent to
99 percent pure) and high purity (99.5 percent pure). High purity is preferred
for medicinal use, ammonia, acetylene, ethylene oxide, and missile fuel. The
tonnage grade makes up about two-thirds of total oxygen production, with the
steel manufacturing industry its largest consumer. Carbon dioxide is the second
107
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-Controlled |
Cbmbuniioc']'
a 12 r
r T.-' y£-.;
Air Separation
(Liquifaction)
19.0 M£-IO,: o ,odu.c'-.ior. -orocesses for industrial gases.
-------
TABLE 21
PRODUCTION OF INDUSTRIAL GASES-1963 AND 1967*
Gas
United of
measure
Production
1963 1967
high purity
Oxygen
lower purity
Carbon dioxide
Hydrogen
Acetylene
Nitrogen
Argon
Million cu. ft. 128,000
Short tons 1,940,000
Short tons 977,000
Million cu. ft. , 95,600
Million cu. ft. 14,700
Million cu. ft. 50,900
Million cu. ft. 970
243,000
1,970,000
1,080,000
158,000
14,300
104,000
1,910
*From Reference #65.
109
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largest volume industrial gas, with over a million short tons produced in
1967. Considerable growth occurred In this industry from 1963 to 1967, with
high purity oxygen, hydrogen, nitrogen9 and argon leading with increases of
82 percent„ 65 percent, 105 percentB and 97 percent, respectively.(65)
Acetylene. Except for acetylenes production of the industrial gases
does not produce significant quantities of solid wastes. The air separation
plants are particularly els,?71 operations« Acetylene production generates
large solid waste quantiti^a using any of three major processes: the Wulff,
calcium carbide, and Sachsss processes„ The gas is used for manufacture of
vinyl chloride monomers 50 percent; vinyl acetate monomer, 24 percent; and for
neoprene, acrylates, and acrylonitrile. In 1967, 590 million pounds of
acetylene were produced„ Its growth rate from 1961 through 1967 was 23 percent
par yaars but through 1972 i: is predicted to be only 0,3 percent per year.(46)
The production process utilising calcium carbide as a raw material
generates large quantities of calcium hydroxide, most of which may end up as
w&sts, Calcium carbide is formed from a mixture of lime and coke heated in an
electric furnace. In the acetylene production process, water is added to the
ealuivcn carbide according to the following reaction;
calelraa carbide •$• water = calcium hydroxide + acetylene
Tb.eT.-e ar® two different processes based on the amount of water used.
The wet proesss consists of adding large quantities of water to the calcium
carbides, with the calcium hydrate residue discharged in the form of a lime
slurry containing approximately 90 percent water.
The dry process adds z. Limited amount of toater to the calcium carbide.
The heat of reaction vaporizes the excess itfater, leaving a dry 'calcium hydrate.
The large•quantities generated along with the other abundant supplies of lime
available. sjslci it difficult ;o use all the calcium hydrate generated. The
-------
present uses for this waste are discussed in Section Six.
The Wulff process for acetylene manufacture is shown in Figure 20. The
process operates by the thermal decomposition of hydrocarbons such as methane,
ethane, propane, butane, ethylene, and natural gas. The hydrocarbon feed stock
is first pyrolized in a furnace, and the products are then quenched in a tar
trap where various tars are removed. This process is followed by compression
and further tar removal by an electrostatic precipitator. The gases are then
purified to recover acetylene.
Other processes produce acetylene from high temperature cracking of
hydrocarbon feed stocks such as natural gas, LPG, naphtha, fuel oil, and crude
oil. The Sachsse process, as shown in Figure 21, uses methane (natural gas)
as the feed stock. The methane is partially oxidized with oxygen with the
excess methane cracked to acetylene by the heat evolved. The resultant gases
are quenched with water and run to a filter where carbon black is removed on
a moving bed of coke. Carbon black is also contained in the quench water.
About 52 pounds of carbon black is removed per ton of acetylene produced(26)
and most of this material is wasted. The clean gas is purified using procedures
similar to that of tha Wulff process.
An electric arc has also been utilized for hydrocarbon cracking to form
acetylene. The arc burners developed are said to have high acetylene yields
with lower carbon black and other byproducts.
Solid Waste Generation-Inorganic Pigments (SIC //2816). Paints are
pigmented liquid compositions containing film-forming materials, thinners,
driers, antiskinning agents, plasticizers, and extenders. The function of
pigments is to protect the paint film by reflecting destructive ultraviolet
light, to strengthen the film, and to give the paint its color. Pigments are
generally inorganic substances, but they may also be pure organic dyes called
111
-------
Fuel
Air
>team <«-^~— — . ~- ^— — - - ™—
Boi
^> ft
Stack =. !
O ,_ Excess ,rx_____J
— Furneoe " fuel 9as
— --- „, ' [j=Cool ing- vjater
1 Tar -j , ^ ,-r ,,0 ., i
1TC'i""£0 ; 1 " "• ~' "•' "
f
.,i
ler
Off gas
Electrostatic ;
p^ibipgtator |
. t
~1
':jf.'st,a.--tars
at ion
•and re-use
%==_
Acetyl
containing
dlacejylene
Stripping
column ,
Absorbgr
Ab^crber
Stabilizer
Figure 20. ' Schematic diagram for manufacture of acetylene from paraffin hydrocarbons by
pyroLysisj. (Wulff Process). .(from Reference #26)
-------
u>
Oxvaen - . ifr Preheater Water
Natural ^ PrphAitor 1 1
gas ^ Pieheatet j
1
Sooty
water
to Soot
filter
Waste
carbon
black
filter
cake
Rectifying
col umn
I
I
un-gas
T
Abs<
\
i
Stripper
Polymer
separation
Figure 21. Schematic diagram of manufacture of acetylene from natural gas by
partial oxidation. (Sachsse Process). (From Reference #26)
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TABLE 22
MAJOR INORGANIC PIGMENTS
SIC 2816
1963 AND 1967*
Production
Pigment
Titanium dioxide (composite and pure)
(100% titanium dioxide)
Chrome green (chrome yellow and iron
blue) (C.PJ
Chrome oxide green (CoP.)
Chrome yellow and orange (C=P,)
Molybdate chrome orange (CoP»)
Zinc yellow (zinc chrcmace) (CoP.)
Iron blues (Prussian blue)
Other major pigments; White lead. Litharge
1963
Short
tons
519,000
2,870
5,220
24,700
8,440
6,860
5,030
, Red lead,
1967
Short
tons
589,000
2,740
5,190
30,700
10,400
7,800
5,580
Zinc oxide
*From Reference #65.
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toners, or organic dyes precipitated on an inorganic carrier, such as aluminum
hydroxide, barium sulfate, or clay, called a lake. The major inorganic pigments
are listed in Table 22.
The major raw materials for inorganic pigment production are ores containing
the necessary metal, a metal compound, or the metal itself. When an ore is the
raw material, the metal must be extracted in the form necessary for pigment
production, such as in the manufacture of titanium dioxide, the most widely
used inorganic pigment. Impurities in the ores used can result in large
quantities of solid wastes.
Metal Based Pigments. Red lead is an example of a pigment produced from
a metal. One method of manufacture is to oxidize lead to litharge (Pbo) in
air, and then further oxidize the litharge to red lead. In another process,
called the fumed process, lead is atomized by compressed air, then forced throng!
the center of a gas flame, converting the lead to litharge which is then further
oxidized to red lead. Few impurities are present in the metallic lead, and
consequently little, if any, solid waste is produced from these processes.
Metal Compound Based Pigments. The compound ferrous sulfate is used to
produce iron blue pigments. Ferrous sulfate solutions are precipitated with
sodium ferrocyanide giving a white ferrous ferrocyanide, or ferrocyanide blues.
The most popular class of yellow pigments, chrome yellows, are produced by
mixing a solution of lead nitrate or acetate with a solution of sodium dichromate.
Ore Based Pigments. Titanium dioxide is an example of a pigment whose
manufacturing process generates large quantities of solid wastes, mainly ore
impurities. It is the largest seller of all white pigments, with 589,000
short tons produced in 1967 and a predicted demand of 790,000 tons in 1970.(46)
Either the sulfuric acid or the hydrochloric acid process (also known
as the sulfate or chloride processes) is generally used. The sulfuric acid
115
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Ilmenite(ground)
Sulfuric acid
Water -^
Scrap,
Iron -'
VV V
] Digester
Thickener
Cooler
Crystallizer
Centrifuge
Waste ife
Steam •--
hijter,
aid
Ferrou?
sulfate
-;'!"-'t2~1^m hydrat?" slurry
Hydrolysis^
tvaporator
to sate
or" disosal
Haste mud
To
. n.. j j
Repu'Jper
©
» HpS(L and FeSOr recovery
ir=Caustic soda
Thickener
1 '
To ••re-use
= Co<
»rse Ti02
=— Wa
Mill
Titanium
dioxide
Figure 22. Schematic diagram for manufacture of titanium dioxide .from ilmenite. (From Reference #26)
-------
process is shown in Figure 22. This process uses ground ilmenite as the
titanium ore, generally 50 to 70 percent titanium dioxide. The ore is digested
hot in sulfuric acid, and the resulting sulfates of iron and titanium are leached
from the reaction mass with water. Both ferrous and ferric sulfates are formed,
with the ferric ion reduced to ferrous by treatment with scrap iron. The
solution is then drawn out of the digester, leaving a residue of unreacted ore.
The residue is a mud containing silica, some titanium oxide, and other insoluble
matter. The mud is disposed of via landfill, or in some cases, hauled to sea.
The solution is clarified in a thickener, with generation of more waste
mud, and sent to a vacuum cyrstallizer. Ferrous sulfate (copperas) crystallizes
out of solution and is separated by centrifuging. There is a small market for
this copperas, but most of it must be disposed of at sea. The remaining liquor
is filtered to remove the impurities, which, as a mud, are sent to disposal.
The filtrate is heated, and the titanium content hydrolizes to insoluble
titanium hydroxide. It is washed and filtered, and the final filter cake is
calcined to yield titanium dioxide. The titanium dioxide is milled and dried to
form anatase titanium dioxide. The filtrate from the first filter contains ferrous
sulfate which did not crystallize and is wasted or recovered along with sulfuric acid.
The wash water from the filters contains titanium dioxide fines. The water can
be sent to recovery operations or directly to disposal. In some cases, the waters
are sent to lagoons where the titanium dioxide settles out. The lagoons are
periodically dredged, and the titanium dioxide mud stored for possible recovery
if economic conditions permit.
The choloride process uses rutile ore (See Figure 23) which is 90-95 percent
pure titanium dioxide with the remainder principally iron oxide and silica. It also
generates a waste mud consisting mainly of impurities in the ore. In the
process, chlorine, coke, and rutile ore are heated in a chlorination furnace
117
-------
R'rtile — ?
Coke— — T j[
Chi crl nati
,-ui • i\. furnace
Chi on me
Liquified
T1C14S
1
on =-o Washer
1
A
Centrifuge
Wests Silicon tetrachloride
]_*^^]_-e.
Column
Centrifuge
JUlaste
^sludge
4
(to recycle)
waste
f-1
00
Silicon
and
aluminum
^urner
Trlchloroethylene
Collector
• r
Alkali
Vent
Absorber
^-.
Strlpper
•^Titanium
dioxide
Chlorine
(to recycle)
Trichloroethylene
(to re=use)
Figure 23. Schematic diagram for manufacture of titanium dioxide from rutile by
chlorination and oxidation. (From Reference #26)
-------
to produce titanium tetrachloride. From the furnace, the material is washed
with liquified titanium chloride which solidifies and precipitates the iron
chloride. The iron chloride is removed by centrifuging as a solid waste. The
filtrate is passed through a column still, silicon tetrachloride is driven off,
and the remaining impurities are removed by a centrifuge. These impurities are
a titanium-rich waste which is added to the iron chloride for disposal. The
titanium chloride is hydrolized and converted to titanium dioxide in a flame
of oxygen and fuel gas.
Another example of a pigment produced from an ore is barium sulfate,
used principally for its stability. The pigment is produced from barytes ore,
and leaves a wet filter cake of ore impurities which must be discarded. Zinc
oxide production, using the American or direct process, also generates a waste
of ore impurities. Crushed Franklinite ore is mixed with anthracite coal and
fed to a furnace. Zinc vapors are released from the ore and oxidized with
air under controlled conditions to yield finely divided particles of zinc oxide.
The Franklinite ore is composed of manganous, ferrous, manganic, and ferric
oxides, along with the zinc oxides which account for 20 percent of the ore.
These impurities remain in the furnace as a residue along with unburned coal.
The clinker is either dumped as a waste or in some instances used for the
manufacture of Spiegeleisen, a manganese alloy useful in steel making.
Solid Waste Generation-Miscellaneous Inorganic Chemicals (SIC #2819).
This group of chemicals, containing many thousands of chemicals derived from
numerous raw materials, is the largest within the inorganic chemical industry.
The raw materials are found in many different mediums including ores, underground
deposits, sands, and sea water.
Within this chemical group are a number of chemical families consisting
of compounds of a basic inorganic chemical. These families are listed in Table
119
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TABLE 23
MAJOR INORGANIC CHEMICALS
SIC 2819
PRODUCTION 1963 AND 1967*
Production
1963
Short tons
1967
Short tons
(100%)
3,990,000 5,710,000
22,500 **
6,750,000 12,300,000
1,200,000 1,940,000
Aluminum compounds
Aluminum oxide (except natural alumina) (100%) 4,820,000 6,050,000
Aluminum sulfate 1,010,000 1,100,000
Aluminum hydroxide (1CC%) 230,000 275,000
Aluminum chlorids 51,800 60,200
Ammonium compounds
Ammonium nitrate (100%)
Ammonium chloride
Ammonia (100%)
Ammonium sulfate (100%)
Calcium compounds
Calcium carbide 1,110,000 912,000
Calcium carbonate (1CC%" 159,000 190,000
Calcium chloride 916,000 1,170,000
Calcium phosphaf.es (ICC") 240,000 392,000
Iron compounds
Ferric chloride (100%) 37,000 38,600
Ferrous sulfate 160,000 197,000
Phosphorus compounds
Phosphorus oxychloride (1CO%) 23,900 32,800
Phosphorus psntasulf:';•£ (:..;;"%) 34,000 48,700
Phosphorus trichloride. F.C>J/T; 26,800 51,100
Phosphorus elemental 488,000 587,000
Phosphoric acid (100%) 2,900,000 5,190,000
Potassium compounds
Potassium sulface (100%' 244,000 244,000
Sodium compounds
Sodium silicates 865,000 926,000
Sodium chlorate (100%) 124,000 155,000
Sodium (metal) (100%) 126,000 164,000
Sodium phosphates 1,110,000 1,370,000
Sulfur compounds
Sulfur (elemental) (lo •? .oi
-------
23, along with the production of the major chemicals within the family.
Aluminum Compounds. The basic raw material for production of aluminum
compounds and metallic aluminum is alumina or aluminum oxide, which is found
naturally as the mineral corundum or in the bauxite as hydrated aluminum oxide.
Bauxite is the source of the major aluminum compounds, namely commercial
aluminum oxide, aluminum sulfate (alum), aluminum chloride, and aluminum
hydroxide. The processes using bauxite generate large quantities of wastes
consisting mainly of unreacted ore.
Aluminum sulfate is used for water treatment, as well as a mild astringent
and antiseptic for the skin, for dyeing, and in sizing paper. Aluminum chloride
is used in the petroleum industry and in various phases of organic chemical
manufacture, such as a catalyst in alkylation of paraffins and aromatic hydrocarbons
by olefins, and as a catalyst in the formation of complex ketones, aldehydes,
and carboxylic acid derivatives.
The production of alumina is one of the largest waste generators. The
bauxite generally used contains a high percentage of iron oxide, silica, and
other insolubles which are generated as solid wastes. A flowsheet of a modified
Bayer process is outlined in Figure 24. Bauxite ore is slurried with a caustic
solution and sent to the first of three digesters. The digester effluent
contains the alumina content as sodium aluminate; it is passed through flash
tanks in series. The cooled effluent, which contains about 3 percent red mud
residue depending on the bauxite used, flows to filter presses or mud settlers
where it is removed. The red mud is water washed to recover caustic, and
usually piped to large diked lagoons for disposal. The remaining traces of
mud are removed, and the filtrate passes to vacuum flash tanks. The cooled
liquor goes to precipitators, where seed crystals of aluminum hydrate are
used to precipitate aluminum hydrate from the solution. The coarse aluminum
121
-------
Bauxite
NaOH o
Lime (.
Stes
r Na2C(>3 — —
L± used/ =—
ia
-
Re co VG Jfe d
stem
Grinding
-» i
M-5 vf n a
i
V
--J
I
1
1
; c
/-jTP.'*.>O .
ratios
QJ:
Ejr^i-..-.-^ k
|
';
Dilution -
p^vioiSt.'TS
JlL^jh tanks
_ Separation af
red vauds
r~
Hashing of
red muds
1
Red muds
to waste
7inal
1 —-•'.-•-- s<-a--- |^
i a
i
i
filtering
- Wash water
' lias or EUSJL
oil
V
Calcination =*
-.- :rS?Sitlcn
v / 3
i
Separation of
AI(OH)3 '
r-
Hashing of
A1(OH)3
! '
Ai(OH)3
priming
Wash
water
\'
Calcined commercial
alumina
Figure 24. Schematic diagram for manufacture of alumina from bauxite
by the Bayer Process. (From Reference #36)
-------
hydrate crystals are washed, dewatered, and calcined to alumina.
For bauxites rich in ferric oxide the quantity of red mud generated is high,
resulting in mud quantities equal to greater than the quantity of alumina
produced. There are certain high-quality bauxites, however, such as those from
Guiana, which generate relatively small quantities of red mud.(36)
In one method of producing alum, a chemical-grade bauxite with a low iron
content is used. The waste from this process is less than that from alumina
production, and consists mainly of the ore impurities silica, titania, and
aluminum silicates. The mud produced when the bauxite is reacted with sulfuric
acid is removed in a settling tank and is pumped to diked waste beds.
Aluminum chloride can be produced both from bauxite, usually low in both
iron and silica, or directly from metallic aluminum. With aluminum as feed molten
aluminum is reacted with chlorine in a furnace. When primary ingots containing
few impurities are used, the aluminum is almost entirely consumed in the reaction.
When the ingots are secondary aluminum, the impurities settle out as a metal
dross. This dross, depending on its metallic content, is either sold for scrap
or discarded.
Amonia Compounds. Second only in importance to sulfuric acid, ammonia is
necessary for the manufacture of many 'chemicals such as calcium and sodium nitrate,
ammonium sulfate, nitrate and phosphate, ammoniated superphosphates, urea, aqueous
ammonia, soda ash, nitric acid, nearly all explosives, and other products. Ammonia
is produced by reacting hydrogen and nitrogen in a three-to-one ratio using many
variations of the original Haber process.
Ammonium nitrate and urea are both important nitrogen carriers for fertilizers
and are also used for manufacture of explosives such as dynamite. Urea is used as
a protein supplement feed for ruminants, and for plastics manufacture, in
combination with formaldehyde and furfural. Urea production in 1967 was over 4
billion pounds, and ammonium nitrate production over 5.7 million short tons.(65)
123
-------
In the production processes for both chemicals, a prilling tower is
sometimes used where the chemical is solidified into spherical pellets called
prills. The particles are dusted with clay or fine diatomaceous earth to
minimize caking tendencies. A sludge is produced from these operations consisting
of clay, small quantities of product, and clay from filters collecting unused
and contaminated dust.
Ammonium chloride, a chemical used largely in dry cells, may be produced
as a byproduct of the Solvay process for soda ash. The final waste liquor of
the Solvay process contains calcium chloride and sodium chloride. The liquor
may be evaporated to recover sodium chloride, leaving a 50 percent calcium
chloride solution. This solution is saturated with ammonia and carbon dioxide
in an autoclave. Calcium carbonate is precipitated and filtered off, and
ammonium chloride is crystallized from solution. The calcium carbonate is a
filter residue waste which is discarded.
Another process produces ammonium chloride from the reaction of ammonium
sulfate and sodium chloride solutions. The ammonium chloride is recovered by
crystallization. The reaction is as follows:
ammonium sulfate + sodium chloride = sodium sulfate + ammonium chloride
The byproduct sodium sulfate is separated from the ammonium chloride product and
if possible sold or converted to Glauber's salt, which is sodium sulfate decahydrate,
and sold. The market is poor for both sodium sulfate and Glauber's salt and much
of it is wasted. Production of ammonium chloride in 1965 was 27,400 tons with
only small growth predicted in the near future.(46)
Ammonia is also important to the production of nitric acid. In early
years, nitric acid was produced from Chile saltpeter. Current processes are
base'd on an oxidation reaction between ammonia and air or oxygen which generates
little or no solid wastes. Its major use is in the production of nitrates in
-------
both the inorganic end organic fields and nitro derivatives of organic chemicals.
Production of nitric acid in 1967 was 6,260,000 short tons.(65)
Calcium Compounds. Calcium compounds are generally derived from limestone
or lime, and gypsum. For chemical usage, a rather pure ore is preferred to
minimize byproduct wastes. Lime (calcium oxide) and gypsum (calcium sulfate)
also appear as wastes from certain chemical processes. Lime is a cheap commodity
since limestone deposits are abundant. In many cases where lime wastes are
generated, it is uneconomical to attempt to remove residual impurities in the
lime, and in other cases, available uses may not be able to consume all that is
generated. The same is true with calcium sulfate wastes generated by such
processes as hydrofluoric acid production. Gypsum can be used for making plaster
wall board, but the waste gypsums generated are generally of a form or contain
residual impurities that require additional processing before they can be used.
It is usually cheaper to use the ore, which is readily available at a low cost.
Calcium chloride is the other compound in the waste liquor of the Solvay
process. After the sodium chloride is removed, the solution is 50 percent
calcium chloride. The liquor is concentrated, and the calcium chloride
crystallized. Only selective quantities determined by demand are produced,
however, and the rest wasted. Calcium chloride is used in deicing roads, dust
control, and concrete treatment.
Iron Compounds. The most abundant industrial iron compound is ferrous
sulfate (copperas). It is a waste product of the pickling process in which
steel surfaces are cleaned preparatory to electroplating, tinning, galvanizing,
or enameling operations, and also of the sulfuric process for production of
titanium dioxide. It has been used to produce other iron compounds, and in
conjunction with chlorine, is used as an iron coagulant in treatment of sewage
and industrial wastes. These uses do not nearly consume all the ferrous sulfate
that is produced; nost is wasted.
125
-------
Ferric hydroxide is produced from ferrous sulfate, and is used in
production of other iron compounds such as ferric sulfate, ferric sodium
oxalate, and ferric malate. Ferric oxide, a red pigment, is produced by
calcining ferrous sulfate.
The demand for most iron compounds is small, with the result that
production processes are also relatively small. Solid wastes from these
production processes would normally be low volume and relatively easy to
handleo
Magnesium Compounds. Magnesium, one of the most widely distributed
elements, occurs generally as the chloride, silicate, hydrated oxide, sulfate,
or carbonate in either complex or simple salts. The principal sources of these
salts are sea water, certain salt wells, bitterns from sea brines, salines,
dolomite, and magnesite. Solid wastes, consisting mainly of impurities
in the feed material, are generated by many of the magnesium production
processes used.
The production of magnesium hydroxide from sea water generates a waste
sludge from a number of points in the process. In this process, sea water
is pumped to hydrotreaterss and just enough dolomitic or high calcium of lime
is added to precipitate carbonates which are raked off and disposed of. More
dolomite is added to the treated water, which precipitates magnesium hydroxide.
The magnesium hydroxide stays in suspension and is removed with the overflow.
The underflow is cycled to remove all cf the magnesium and the residue is
wasted. The residue is a sludge consisting mainly of silicacious material
and unreacted limestone.
Magnesium hydroxide is used to produce magnesium chloride by dissolving
the hydroxide in 10 percent hydrocholoric acid. The solution is concentrated
in direct-fired evaporators and dried. The magnesium chloride may be used
-------
in electrolytic cells to produce magnesium.
Phosphorus Compounds. Phosphate rock is the raw material used for
•manufacture of phosphoric acid, superphosphate, phosphorus, and other compounds.
The greatest consumer of phosphorus compounds is the fertilizer industry.
Impurities in the phosphate rock used in the various processes generally are
removed as solid wastes.
Two important processes for phosphoric acid use phosphate rock as the
feed material. These are the wet process and the furnace method, both of
which generate substantial quantities of solid wastes. The wet process for
phosphoric acid is shown in Figure 25. Ground phosphate rock is digested with
a mixture of sulfuric acid and recycled phosphoric acid to form phosphoric
acid and gypsum. From the digester, the slurry passes to tilting pan-type
washing filters where phosphoric acid is removed from the gypsum filter cake.
The filter cake gypsum (calcium sulfate) is ordinarily wasted by slurrying it
with waste water and piping it to a settling pond. The reaction which takes
place in the digester is as follows:
calcium phosphate + sulfuric acid + water = phosphoric acid +
calcium sulfate + water
The acid filtrate is evaporated to obtain the desired concentration of
phosphoric acid.
In the blast furnace method for phosphoric acid as shown in Figure 26,
pulverized phosphate rock is mixed with ground coke, a binder added, and the
mixture compressed into briquettes. The briquettes are charged into the blast
furnace along with sand and additional coke. The evolved gases contain carbon
monoxide, nitrogen, and phosphorus. The clean gas is split into two portions.
The first is passed through phosphorus condensers to produce elemental phosphorus.
The second portion is passed into regenerative stoves where it is oxidized to
phosphorus pentoxide. From the stoves, the produce is hydrated and cooled
127
-------
Sulfuric
acid
Gases
Absorption
tower
Dilute
phosphoric
acid
Phosphate
rock
— Water
—©FluorosTliac add
to recovery
Digestors
Cooling
air
Dilute phosphoric
acid to recycle
Wash water
Filter banks
Filtrate
receivers
\Uaste gypsum
filter cake
Evaporator
Phosphoric
acid
Figure 25. Schematic diagram for manufacture of phosphoric acid from phosphate
rock by the wet process. (From Reference #26)
-------
Phosphate
rock
B1
^
nder
I f
Briquet
press
Coke Sand
Phosphorus
/vapor
Y
Du
Blast
furnace
»• CO
Hot_
"* air"
st
Hector
Hot
blast
stove
J
1
Compressed
"* air
. o iu pnospr
Steam
t
"— - Ste
m boi
1
am
ler
Hy<
t
Water
_L
Carbon
dioxide
end other
gases
Hydrator
NJ
VO
Ferrophosphorus
Cottrell
precipitator
Phoshoric acid
Phosp
(90%)
Figure 26. Schematic diagram for manufacture of phosphoric acid and phosphorus from
phosphate rock by blast furnace. (From Reference #26)
-------
TABLE 24
PRODUCTION OF SODIUM PHOSPHATES-1967*
Production
Sodium Phosphate
1,000 Short tons
Monobasic (100%) 17.4
Dibasic (100%) 22.6
Tribasic (100%) 61.7
Tetrabasic (100%) 109.0
Meta (100%) 88.1
Acid pyro (100%) 25.2
Tripoly (100%) 1,050.0
*From Reference #65.
-------
and passed through Cottrell precipitators for removal of entrained phosphoric
acid The condensed acid is purified by treatment with hydrogen sulfide,
followed by filtration.
About 95 percent of the phosphorus in the rock raw material is volatilized,
and the remaining phosphorus, along with the impurities in the rock consisting
chiefly of calcium silicate and iron compounds, leave the blast furnace as
aolid wastes. During the time the rock mixture is in the blast furnace,
the furnace is tapped once an hour to remove the calcium silicate as a slag.
Every 12 hours the furnace is tapped to remove the iron impurities as a heavier
ferrophosphorus. The slag can be used for its calcium content in glass
manufacture, liming of soil, or as roadbed ballast. The ferrophosphorus can
be sold as a phosphorus additive to steel.
Elemental phosphorus is also produced using an electric furnace in place
of the blast furnace. The same solid wastes are generated from this furnace.
The phosphorus can then be used for production of phosphoric acid in a process
generating little or no solid waste. In 1967, 1.1 million short tons of
phosphoric acid were produced from phosphorus, and 4.0 million short tons from
phosphate rock.(65)
Sodium phosphates are the largest tonnage chemicals based on pure phosphoric
acid. Of these, disodium phosphate, is the base of all the other
phosphates. The most important use of sodium phosphates is in detergent
manufacture, which consumes 80 percent of the production. Production of the
important sodium phosphates is listed in Table 24.
The production process for manufacture of disodium phosphate and trisodium
phosphate is shown in Figure 27. A sodium carbonate (soda ash) solution and
phosphoric acid are added to a mixing tank under conditions promoting high
carbon dioxide liberation. The solution is boiled with steam until all of
131
-------
Sodium
carbonate
solution
Waste,
Phosphoric
acid
Sodium hydroxide
solution
Sodium sulfate
and
sodium carbonate
Di sodium
phosphate
Trisodium
phosphate
Figure 27. Schematic diagram for manufacture of disodium phosphate and trisodium
phosphate from phosphoric acid and sodium carbonate. (From Reference #26)
-------
the carbon dioxide has been driven off. The resulting disodium phosphate
solution is filtered hot and the filtrate split into two portions, one for
diosdium phosphate and the other for trisodium phosphate manufacture. The filter
residue is a white waste mud consisting of silica, iron, and aluminum phosphate.
One part of the solution is cooled in a crystallizer to yield crystals
of disodium phosphate which are filtered from the mother liquor and dried. A
50 percent sodium hydroxide (caustic soda) solution is added to the other
part of the solution. The hot solution is filtered and the filtrate crystallized
and dried to yield trisodium phosphate crystals. The filter residue is again
a white waste mud. The mother liquor is sent to a double-effect evaporator,
concentrated, and sent back to the mixing tanks for reprocessing. Sodium
sulfate and sodium carbonate are discharged from the bottom of the evaporator.
The sodium sulfate (salt cake) may be sold for sulfate pulping, detergent, or
glass manufacture. The sodium carbonate may be recycled back to the original
mixing tank. Manufacture of the other sodium phosphates is based on these two
phosphates.
Potassium Compounds. Potassium salts, chiefly potassium chloride and
potassium sulfate, are basic chemicals for production of potassium compounds.
Potassium chloride is obtained from deep deposits of sylvinite or langbenite.
Another important source of potassium chloride is Searles Lake at Trona,
California, a deposit of solid sodium salts permeated by a saturated complex
brine. The brine is processed to obtain potassium chloride along with borax
and other saline products.
Potassium chloride is obtained from sylvinite by two major processes:
fractional crystallization or flotation. Sylvinite ore is approximately 43
percent potassium chloride and 57 percent sodium chloride. Both processes
operate to remove the potassium chloride from the sodium chloride. In the
133
-------
process, sodium chloride is removed as a wet cake and discarded.
Potassium sulfate is produced by treatment of potassium chloride with
sulfuric acid or by fractional crystallization of kainite. Potassium chloride
and potassium sulfate are used as a source of potassium salts in fertilizers.
Other important potassium chemicals are potassium hydroxide, produced
from electrolysis of potassium chloride solution; production of potassium
carbonate from potassium hydroxide; and potassium nitrate produced from sodium
nitrate and solid potassium chloride.
Sodium Compounds. Most of the sodium compounds are derived directly or
indirectly from ordinary salt, sodium chloride. Salt is a mineral and must be
mined from the earth or the sea and refined. It is usually obtained in three
different ways: solar evaporation of sea water and salt-lake brines, mining
of rock salt, and from well brines.
In the chemical process using brines, the sodium chloride must be removed
from the brine impurities. This is usually accomplished by adding dilute
solutions of caustic soda and soda ash to remove the calcium, magnesium, and
iron compounds. These impurities are precipitated and settled out of solution
as a slurry. The slurry is sometimes sent to settling ponds where the waste
solids settle out.
The two most important sodium compounds, sodium carbonate (soda ash) and
sodium hydroxide (caustic soda) are alkalies and were discussed earlier along
with sodium bicarbonate. Sodium phosphates were also discussed earlier.
Sodium sulfate or salt cake is also a naturally occurring sodium salt
used as a raw material for other sodium chemicals. Glauber's salt, used in
large quantities by the kraft paper industry, is a form of salt cake. It is
also a byproduct of some chemical processes. It is produced directly from
natural brines, but also is produced from salt and sulfuric acid with additional
-------
production of hydrochloric acid. The process is shown in Figure 28. Salt
and sulfuric acid are charged to a furnace (MANNHEIM furnace) and slowly heated
to a temperature just below fusion. Hydrogen chloride gas is evolved and sent
to hydrochloric acid recovery. Salt cake (crude sodium sulfate) is obtained
from the periphery of the furnace. To obtain Glauber's salt, part of the salt
cake is dissolved in hot water and neutralized with soda ash and lime. The
neutralization precipitates iron and alumina which settle to the tank bottom.
The mud is filtered from the solution and the waste filter cake discarded.
The filtrate is crystallized to obtain Glauber's salt.
Sodium chromate and dichromate are produced by calcining a mixture of
chromite ore, limestone, and soda ash. Solid wastes generated from this
process are the impurities in the limestone and chromite ore used.
Sulfur Compounds. Sulfuric acid is considered to be one of the most
important chemicals in the industrial chemical industry. It is a strong and
relatively, cheap acid which is used by countless industries, but is not usually
present in finished products. Production is by two main processes, the Contact
process and the Chamber process; the Contact process is the primary producer.
Both processes use sulfur dioxide to produce sulfur trioxide which is converted
to sulfuric acid. Sulfur dioxide is obtained from burning elemental sulfur
which is greater than 99.5 percent pure. This method accounts for more than
70 percent of all U.S. acid production. The predominant sources of elemental
sulfur are mines on the Gulf Coast of Louisiana, Texas, and Mexico. The recovery
of sulfur from sour natural and refinery gas is a relatively small source.
Frasch-process sulfur contains 0.01 percent to 0.02 percent ash, and gas-recovered
sulfur only 0.001 to 0.003 percent ash.(55)
When the elemental sulfur is burned, a portion of the ash or inert materials
remains as a solid waste. The ash is only a small percentage of the elemental-
135
-------
Sulfuric
acid
o\
Hydrogen chloride gas (to recovery)
Water
Soda ash or lime
Steam
0
Salt cake
(sodium sulfate)
Waste
mud
Mother liquor
1
Crystallizer
^Glauber's salt
(Na2S04« 10H20)
Figure 28. Schematic diagram for manufacture of Glauber's salt from salt
and sulfuric acid. (From Reference #26)
-------
sulfur used and amounts to only very small quantities of waste at individual
plants. The balance of the process, however, is relatively clean.
Sulfur dioxide, an intermediate in the production of sulfuric acid, is
also used as a bleaching agent, a food preservative, in sulfite pulp manufacture,
and in the production of many other chemicals. Both sulfuric acid and sulfur
dioxide are the main chemicals used for sulfate formation and for sulfonation
to obtain the many chemical compounds containing sulfur. Many sulfates have
been discussed in previous sections.
Hydrofluoric Acid. The important inorganic acids, phosphoric, sulfuric,
and nitric, were discussed previously. Hydrofluoric acid, a major inorganic
acid whose production generates significant quantities of solid waste, should
also be included in this discussion. Hydrofluric acid (HF) is important to
manufacture of fluorocarbons and aluminum; the latter consumes 84 percent of
the HF produced. In 1967, production of HF was 190,000 short tons with a
growth rate forecast at 5 percent through 1971.(46,65)
The major process for production of hydrofluric acid is shown in Figure
29. Acid-grade fluorspar and sulfuric acid are continuously charged to a
reactor fired by fuel gas. The reaction is as follows:
calcium fluoride + sulfuric acid = hydrofluoric acid +
calcium sulfate
The calcium sulfate (gypsum) is a residue containing only 1 percent or less
of unreacted fluorspar, and is continuously discharged at weights equal to 1.75
times that of the spar charge. This waste is usually slurried and piped out
to waste beds where the solids settle out and eventually dry to a hard scaly
mass. The gas from the reaction is absorbed in water and concentrated by
distillation to yield the various grades of aqueous and anhydrous hydrofluoric
acid.
137
-------
00
Sutrfuric
fiCid (99%.)
Water.
Hydrofluoric
acid (80%)
Anhydrous
hydrogen
fluoride
Figure 29."s Schematic/.''diagram for-manufacture :6'f hydro fluoric acidffroiB fluorspar
• Ijil'furic'
-------
SECTION SIX: MANAGEMENT OF SOLID WASTES
Storage, Collection, and Transportation 141
Non-Process Waste 141
Process Wastes 142
Disposal 143
Non-Process Waste 143
Process Waste 145
Disposal Agencies 157
Development of the Management System 159
Non-Process Waste 159
Process Wastes 161
Recycling, Utilization, and Recovery of Process Wastes 162
Figures
30 Schematic diagram of combined process and non-process
waste incinerator 146
31 Schematic diagrams of tar burners 148
32 Schematic diagram of open pit incinerator 150
33 Schematic diagram of chemical plant non-process solid
waste disposal alternatives 158
34 Schematic diagram of chemical plant process solid waste
disposal alternatives 160
139
-------
SECTION SIX: MANAGEMENT OF SOLID WASTES
Management of solid wastes includes waste storage, collection,
transportation, preparation, and disposal. This section provides a brief
description of the methods and equipment used for management systems in the
industrial chemical industry, and discusses their suitability to the various
waste types, along with an analysis of system alternatives.
Storage, Collection, and Transporation
Non-Process Waste. The systems used by industrial chemical plants for
the storage, collection, and transportation of plant non-process waste are
the same as those used by other industrial plants and commercial establishments.
Containers for waste storage are located throughout the plant near generating
areas. The containers consist of a variety of receptacles such as boxes and
barrels, or those designed for solid waste storage, such as dumpster boxes
or concrete bins. The majority of plants salvage metal waste and provide
separate containers for metal and trash. Normally the wastes are collected
from the storage facilities by truck.
!
Systems vary for non-process waste collection and transportation to final
disposal. A plant may use trucks to pick up solid waste from each container
and haul it directly to disposal, or the smaller containers may be emptied into
larger ones and then hauled to disposal. In some cases one or two large
containers, sometimes large stationary compactors, are used to receive all
the wastes of the plant, which are periodically hauled to disposal. Many plants
have instituted a completely containerized system where large specially-designed
containers are located throughout the plant. They are picked up periodically
by trucks equipped to haul the entire container to disposal, after which the
container is returned to its location. The system chosen by a plant depends
Preceding page blank 141
-------
in part on the quantities of trash to be handled and on costs.
Process Wastes. Normally process wastes are handled separately from
non-process wastes. Storage facilities for process wastes consist of a variety
of bins9 barrels, .fiber drums, tanks, and luggers or dumpsters, as well as
pondss tank trucks, and railroad cars; they are sometimes piled casually on
the ground.
Heavy sludges that cannot be pumped are generally stored as described
above. Sludges stored in bins, or stored casually, must be removed and desposited
in trucks for transportation to disposal. If they are contained in fiber drums,
the drum is usually disposed of along with the sludge. Luggers and dumpsters
are metal containers which can be lifted and their contents dumped into a
truck, or the container carried to the disposal area and dumped. Sludges
stored in railroad cars are generally off-quality product which is stored longer
than usual to allow time for possible marketing opportunities. In many cases,
the railroads will haul sludges stored in their cars to land which they own.
Most filter residues would be handled in the same manner as sludges.
Tars and aqueous sludges that can be pumped are stored in barrels, tanks,
ponds, tank trucks, and railroad cars. Barrels are either emptied at the
disposal site or in landfills; sometimes,, they are buried along with the waste.
Tanks are often used both at the point of waste generation and at the disposal
site. They are used with tar incinerators not only to provide storage but
also to provide an opportunity to mix various wastes«to form a desirable blend
for burning. Some tanks are heated to liquify tars that would solidify at
normal temperatures. Similarly9 tanks are often equipped with agitating means
to prevent1 settling of suspended soliuj ^nr". to assist in preventing tars
from solidifying.,, When the waste is stored in ponds, it is either pumped by
pipeline directly from the pond to disposal or into tank trucks. As with
-------
sludge, railroad tank cars sometimes are used for off-quality tar wastes.
Flyash is either stored in bins or hoppers at the powerhouse or pumped
out to ponds or lagoons. Trucks, or in some cases rail cars, pick up the
flyash from hoppers and transport it to disposal. Depending on the capacity
of the pond or lagoon, the flyash either remains in the basin or is dredged
out and hauled to disposal.
Transportation equipment used for hauling process solid waste from storage
to disposal consists of open dump style trucks, tank trucks, railroad cars,
barges, and pipelines. As previously mentioned, some tank trucks must be
capable of heating and agitating the waste to prevent solidification. Barges
are used to transport some waste to ocean disposal. In most cases where pipelines
are used, the waste is not stored, since the pipeline carries the waste directly
from the generating process to disposal in a continuous operation.
Disposal
Non-Process Waste. Disposal methods for non-process wastes as used by
the chemical industry are essentially the same as those used for municipal and
commercial refuse. The methods are all variations of land disposal or
incineration. No plants were found that employed composting, and the few
governmentally operated composting plants in the country receive an insignificant
amount of non-process waste from industrial chemical plants.
Land disposal methods fall into the categories of burning dumps, open
dumps, landfills, and sanitary landfills. Dumps exist where the solid wastes
are deposited on the ground and left in the open for considerable period of
time. In some cases the dumps are deliberately fired to reduce waste volume.
This practice is increasingly running afoul of state regulations. In a landfill,
the solid wastes are periodically covered with fill material. A sanitary
143
-------
landfill is a particular type of landfill which must meet certain criteria—i.e.
(1) It must be operated without creating a nuisance or a hazard to public
health or safety; (2) The solid wastes must be confined to the smallest practical
area, reduced to the smallest practical volume, and covered with a prescribed
layer of earth at the conclusion of each day's operation; and (3) Ground water
contamination from leaching must be controlled. This is the most desirable
form of land disposal. The disposal of refuse by landfilling has been studied
extensively by a number of authors.(17,19,50)
Incineration of non-process waste is also accomplished by a number of
methods, including open burning, burning in tepees, and incineration in single
and multiple chamber incinerators with or without stack air pollution control
equipment. Incineration of refuse has been described in detail in a number
of publications.(16,42,62)
In the past, many chemical plants disposed of non-process waste by open
burning or in tepee burners, which are large tepee-shaped structures serving
to protect the burning material from blowing about, but having little beneficial
effect on reducing air pollution. Air pollution regulations have virtually
eliminated these two waste disposal forms at chemical plants, and they have
been replaced by incineration, landfilling, or hauling waste to nearby private
or municipal facilities.
Most landfills operated by industrial chemical plants do not meet all
the criteria to be considered sanitary landfills. They are often not covered
each day, but this is usually not as critical as with municipal refuse since
the small amount of garbage in the plant, trash is not as likely to attract .
rodents. In addition, most are not properly located or sealed to prevent
possible ground water pollution. These same conditions have been reported
for private and municipal landfills.(43) In addition, plant landfill operators
-------
may often experience difficulty in providing proper compaction of the waste,
thereby leaving voids which may cause uneven settlement. The difficulty stems
from the large quantities of discarded cardboard boxes, crates, and fiber drums
which are unusually hard to compact.
Process Waste. Disposal of process solid wastes is generally accomplished
by incineration, land disposal, settling in lagoons or ponds, and ocean dumping.
This section presents a brief description of each method.
Conventional Incineration. Many types of conventional incinerators designed
for combustion of refuse have been adapted for disposal of ehcmical process
solid wastes. The incinerators have been used for solid chemicals, sludges,
filter residues, off-quality product, and tars. The waste must contain a
sufficient percentage of combustible material and be physically compatible with
the Incineration equipment. For example, certain wastes such as sludges
may be dried from 80 percent moisture to 15 percent moisture before incineration.
Some incinerators have been designed to burn both process and non-process
wastes together. Figure 30 shows a typical incinerator equipped to incinerate
refuse, solid chemicals, heavy sludges, and tars. Plant refuse is dumped into
a storage pit and deposited by a bucket crane into a receiving hopper. The
waste is conveyed to a rotary kiln where primary combustion occurs. Other
units may have manual charging and either a grate furnace or a rotary hearth
furnace instead of the rotary kiln. At the end of the kiln, the ash is dropped
to a hopper and the combustion gases pass through a secondary combustion zone,
possible spray cooling and air pollution control equipment, and then to the
stack.
Tars or other combustible liquids are pumped to a burner and fired in
the primary combustion chamber of the furnace. Low ash content tars are most
desirable for this type of incineration, since the tars are burned in suspension
145
-------
Waste
gases
Stack
Solid and
bulk process
wastes
Secondary
combustion
chamber.
Air pollution
control
equipment
Tars and
combustible
slurries
Spray
cooling
chamber
To ash
disposal
system
\/
To waste
water
treatment
system
To ash disposal
or waste water
treatment systems
Figure 30. Schematic diagram of combined process and non-process waste incinerator.
-------
and any ash produced could cause air pollution problems. Solid chemicals and
sludges are also charged to the primary combustion chamber. In many cases
they are contained In fiber drums, and the whole package Is charged as a unit.
Shredding of the waste prior to Incineration Is normally not done.
Temperatures In these units will range from 1400 F to 2000 F. It is
desirable to maintain temperatures at the higher end of this range to insure
complete breakdown of organic materials. Generally, incinerators of this
type cannot handle materials which will produce corrosive combustion products
(e.g., HC1 from the destruction of chlorine-containing organics), unless special
materials of construction are used and precautions are taken to scrub such
reactive materials from the exhaust gases.
Tar Incinerators. Tar incinerators are specially designed for burning
tar wastes or other liquids such as acid wastes, contaminated solvents, and
slurries such as waste water sludge. The design of the incinerator depends
to a large extent on the combustion products of the tar to be burned. Tars
vary considerably in chemical composition, and thus in combustion characteristics
and products.
The four basic types of tar burners are shown in Figure 31. The primary
combustion zone and firing mechanism may vary (for some units) from those shown,
but the basic sequence of operation is essentially the same.
Units 1 through 4 provide for progressively greater control of
combustion. Burner //I is usually used to incinerate highly volatile waste
tars with negligible ash content and no gaseous pollutant combustion products.
The combustion flame burns completely in the open, and when properly operated
is smokeless. Burner //2 provides for greater control of the combustion process
by enclosing the combustion zone and providing a stack for discharge of gases.
A secondary mixing and combustion chamber and a settling chamber, as well
147
-------
Tar
Tar
Tar
Auxiliary
fuel
f
Atomizing
air
blower
Smokeless Tar
Burner #1
Stack
Secondary combustion zone
^Tempering
Combustion air blowers
air
blower
Stack
Stack
Air pollution
control equipment
Figure 31. Schematic diagrams of tar burners.
-------
as a higher stack, are provided In burner #3. This burner would be used for
tars which might generate small quantities of particulate matter on combustion.
The settling chamber would remove some particulate, and the taller stack would
assist in dispersion of partlculates to the atmosphere.
For tars which on combustion generate high quantities of particulates
or noxious gases, burner #4 is required. These tars require a highly refined
burner system and air pollution control equipment sufficient to control
pollutant emissions,
Types of tars which contain halogens require equipment for incineration
similar to that of burner //4. Burning this material might generate the elemental
halogen or the acid gas. Tar incinerators for this material are usually
designed to generate the acid gas which is then scrubbed.
An example of tars containing halogens are those from the production of
chlorinated organic chemicals. Large volumes of this waste, containing some
i
residual chlorine, are generated. The chlorine atom in the waste is not
combustible, but carbon and hydrogen are. Hydrogen will react with chlorine
to form the acid gas HC1, but unless there is sufficient hydrogen to combine
with all the chlorine, unreacted chlorine will be released to the atmosphere
in its elemental form.
In addition, with low combustion temperatures, Intermediates such as
methyl chloride and phosgene may be formed and released. Elemental chlorine
is difficult to scrub from a gas stream and requires special caustic scrubbing
solutions. Incinerator designs for this tar provide for excess hydrogen through
auxiliary fuel such as natural gas or steam at high temperatures. The acid
gas can then be scrubbed from the exhaust using water in either low-energy-packed
bed-type systems or high-energy venturi scrubbers. The scrubbing water becomes
a weak HC1 acid solution. It may either be reclaimed to produce various grades
149
-------
Air header
Loading
Furnace
and
retaining
wall
Figure 32. Schematic diagram of open pit incinerator.
-------
of hydrochloric acid or neutralized and sent to receiving waters, the usual
practice.
Tar burners operate over a wide range of temperatures from about 1800 F
to as high as 3500 F. At these high temperatures, and with the possible presence
of acid gases, corrosion and damage to fire brick can be a serious problem.
Tar burners can handle a variety of tars, slurries, gases, and liquids
including wastes with a high percentage of noncombustible matter or highly
aqueous wastes. Because the wastes are fired through a nozzle, there are
limitations of particle sizes in slurries and on certain characteristics of
tar wastes to prevent clogging of the nozzle. The waste tars which cannot
be incinerated must be treated by an alternate method. These practices usually
result in inadequate disposal.
Other Incineration Methods. An additional type of incinerator used to
handle both process and non-process waste is the open pit incinerator. It is
presently used to Incinerate trash, tars, and sludges. The incinerator is a
box-shaped pit with no top, permitting maximum radiation of the flame to the
sky. Depth of the pit ranges from 10 to 30 feet. Normally, all air is
supplied from an overfire position to produce maximum turbulence and recirculation
of the combustion gases.
A typical open pit incinerator is shown in Figure 32. For solids with
high calorific value and solids that tend to melt, the open pit incinerator
combustion rate and performance have been reported as high, particularly for
wastes with less than 1 or 2 percent ash. However, such an incinerator provides
little control over emission of particulate matter or noxious gases which are
generated by combustion of some wastes.
Fluidized, granular-bed incinerators have been used successfully with
volatile sludges which can be pumped or moved on a screw conveyor. These
151
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Incinerators cannot, however, handle sludges containing large particles, due
to bed plugging.
Waste Heat Recovery. Few industrial chemical plants recover waste heat
from incineration of solid wastes. Although in most cases a plant could use
the heat energy for production of steam, the design, operation, and maintenance
of a waste heat boiler is wrought with problems. Two boiler design problems
which must be given special consideration when firing solid wastes are fouling
of heating surfaces and potential corrosion. For chemical plant wastes, these
design considerations are even more critical due to the diffuse nature of
wastes incinerated and the increased possibility of acid corrosion. Despite
these problems and the expense involved, a few waste heat boilers do operate
successfully at chemical plants for both process and non-process waste
incinerators.
A more common method of utilizing the heat from combustion of wastes
is to fire the waste as a supplementary fuel into the main plant boilers. A
number of plants were found to be using this disposal method for certain tars,
solvents, and other organic liquids. Boilers were found with a waste fuel
burning capability of up to 20 percent of capacity. Little information is
available, however, on the design, operation, or applicability of this procedure
to specific waste types.
Land Disposal. Land disposal of solid wastes by chemical plants consists
of either dumping the waste in piles on the ground or burying it. All the
major types of process solid wastes are sometimes disposed of by this method,
including sludges, tars, off-quality product, filter residues, and flyash.
Wastes dumped on the ground are principally dry chemicals, filter residues,
and heavy sludges. They are generally inert and insoluble inorganic chemicals
which do not generate odors on decomposition or pollute surface and ground
-------
waters through leaching of pollutants. Other effects of some solid wastes
(such as emission of noxious gases, dusting, or esthetic problems) may prevent
disposal by this method. A large percentage of the solid wastes dumped on
the ground are sludges dredged from settling ponds or lagoons.
The second method of land disposal consists of direct burial or covering
the waste with earth. Generally, the plant area for land disposal of process
waste is separate from any landfills for non-process waste. The same problems
associated with landfilling refuse, however, occur when landfilling chemical
wastes. Pollution of surface or ground water is possible if proper precautions
are not taken, especially with readily soluble wastes. Decomposition of the
wastes may produce other chemical and biochemical products or gases which can
also affect water or air quality.
Very little information is available on the mechanism and rate of
decomposition of most chemical wastes when landfllled. The principal soil
transformation process is biological decomposition. Microorganisms are
capable of biological oxidation or reduction of both inorganic and organic
chemicals, resulting in a broad array of chemical and biochemical products.
It has been reported that most aliphatic hydrocarbons are rapidly
decomposed in soil. Hydrocarbons which are unsaturated, branched, and of
high molecular weight are generally more susceptible to degradation than their
saturated, unbranched, low-molecular-weight analogues. Aromatic materials,
on the other hand, are generally considered quite resistant to microbial
degradation in soil and water, and carbon in aromatic forms constitutes a
major portion of the relatively stable soil organic fraction. Once the
aromatic ring is cleaved, however, the resulting straight-chain hydrocarbons
are subject to relatively rapid degradation and oxidation to carbon dioxide
and water.(57)
153
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The rate, extent and direction of microbial transformations in soil,
however, are commonly dependent upon the type and quantity of available energy
sources, availability of essential nutrients, degree of aeration, temperature,
moisture, pH, and the presence of toxic substances. Large variations in these
factors exist in chemical landfills depending on the procedures used and the
chemical wastes disposed. In some cases, when disposing of solid chemicals
or sludges, the material will be mixed with the soil. In other cases no mixing
is practiced, resulting in large slugs of chemical wastes in the fill. Waste
tars or liquids contained in drums are often buried, and when the barrels
corrode, the contents leach into the landfill. More information is necessary
on the effect of these practices and on the fate of landfilled chemical wastes
before land disposal procedures can be formulated which adequately protect the
environment.
Lagoons and Ponds. Lagoons or ponds are both natural water bodies or
man-made water bodies constructed either by digging out a depression in the
earth or by erecting dikes. "Lagoons" normally refer to basins where the
overflow easily passes into receiving waters, and "ponds" are usually those
basins with no overflow. The liquid portion becomes permanently entrapped
in the pond and is reduced only through evaporation. Lagoons are better suited
for wastes with low solids content and ponds for those with high solids content.
Lagoons are used for clarification of both chemical plant process waters and
waste waters, and along with ponds are used for slurries and solids deliberately
slurried to enable transport by pipeline. As the basins fill, they are either
cleaned and the solids removed and discarded, or the solids are left to dry
and new basins are constructed. If the liquid portion of the waste can contaminate
underground water, special precautions must be used to seal the lagoon or pond
bottom to prevent leakage.
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Lagoons sometimes cover many acres and receive thousand of tons of solid
wastes annually. Where a high degree of solids clarification is desired,
Arsons may be arranged in series with each successive lagoon providing
treatment until the desired water quality is reached. Under some conditions
r.erobic or possibly anaerobic decomposition of wastes may occur in the lagoons,
thereby providing further treatment.
Ocean Disposal. Although the mail questionnaire turned up only a
reltlvely small quantity of chemical wastes disposed to the ocean, ocean
disposal of solid wastes is known to be a well-established practice. Specific
areas in the ocean have been set aside for solid waste disposal, some
specifically for chemical wastes. Virtually all types of process wastes are
disposed of in the ocean except possibly flyash. Solid wastes for ocean disposal
are generally loaded aboard a barge and hauled to disposal areas at sea. The
wastes are transported and disposed in bulk or in barrels. Bulk wastes are
either dumped directly or discharged underwater and allowed to mix with the
barge wake. Barreled waste is pushed overboard and usually sinks, and those
that float are shot full of holes.
A preliminary report on ocean disposal off the West Coast indicates that
:uch industrial chemicals as acids, sludges, solvents, spent caustics, waste
liquors, and plating solutions are disposed of at sea.(29) It was estimated
that 1,254,000 barrels of these chemical wastes were discharged in 1968 off
the Pacific coast at a cost of $153,000. A portion of this waste was generated
by chemical plants. Considering the greatest number of large chemical plants on
the East and Gulf Coasts, a greater quantity of chemical wastes may be discharged
~o the Atlantic Ocean and the Gulf of Mexico.
Ocean disposal is said to be attractive for those process wastes that
nre difficult and expensive to treat and discharge without pollution of receiving
155
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waters. However, the referenced report failed to find in its survey any
comprehensive studies performed to determine potential harmful effects of
wastes upon the marine environment and its biota. It is evident from public
concern that these studies will be forthcoming with resultant legislation
regulating ocean disposal.
Deep Well Disposal. Very little use of deep wells for disposal of solid
wastes was reported on the questionnaire. The very nature of most deep wells
prohibits disposal of solid materials and even slurries. They are used
principally for disposal of liquid wastes, and are therefore a waste water
disposal technique.
The deep well disposal technique involves pumping a waste down a well
into a porous and permeable subsurface formation. The formation should be
porous and permeable over a large area and should possess adequate thickness.
Generally, disposal strata consist of sandstone or limestone and, occasionally,
fractured shales. The liquid is pumped into the formation, expanding out in
all directions. Most installations filter the liquid before injection to
remove suspended solids that would plug the formation and render the well
useless.
Our survey indicates that unusual conditions exist in certain areas of
Michigan. Some companies surveyed there used underground disposal methods
for waste liquors containing carbonates, sulfates, silica, and inerts. These
compounds are pumped underground with little trouble, although they are present
as high concentration slurries.
It must be pointed out, however, that this kind of underground disposal
does not fit into the usual category of deep wells. The underground formations
in these cases are actually caverns formed by the removal of brines. The
salt is in solid form and is dissolved with hot water and pumped to the surface,
-------
leaving large cavities.
The number of waste injection wells in use in the United States is not
definitely known, but those which are catalogued number slightly over 100.
They are scattered over sixteen states with Texas, Louisiana, and Michigan
having more than 20 each. A few states have passed laws prohibiting the use
of waste injection wells and, of course, such wells are not practical in some
areas because of unsuitable geologic formations.
Disposal Agencies
In the management of solid wastes, a plant can elect to buy collection,
transportation, and disposal services from either private or municipal sources,
rather than handle everything itself. Some plants, mainly small plants, are
provided with trash collection and/or disposal by their local municipality,
financed through general taxation. Most often, however, the plant must provide
transportation of trash to municipal facilities and pay by the ton for disposal.
Some chemical process wastes, including sludges and barreled tars, are
disposed of at public facilities. Many chemical plants which dispose of trash
at public facilities strive to provide private disposal for their process wastes
to avoid problems. Due to growing concern in recent years, regulations on
the types of waste that may be deposited at public facilities exclude chemical
waste. These regulations have increased the burden on chemical plants to
provide their own disposal facilities.
Along with municipal waste services, there are also many private companies
which provide either waste hauling, disposal facilities, or both, for process
and non-process waste. A plant may elect to have certain of its wastes handled
by such a company. Sometimes these private companies are also the main agency
for disposal of refuse for the surrounding community.
157
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_n
X
PLANT
1 1
Stone and Garbage
concrete
!
1
i 1 t 1
Clean
fill
1
Paper
\
Landfill
i
1
Ash-
I
Glass
1
1
i
\
*
,
Metal
i
\
!
Incineration
_J
1 1
Wood
Salvage
Figure 33. Schematic diagram of chemical plant non-process solid
waste disposal alternatives.
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Development of the Management System
The components of solid waste management systems used by Industrial
chemical plants have been described in the preceding sections. A chemical
plant's selection of which method to use for storage, collection, transportation,
and disposal involves many factors. The plant must choose a management system
which is economical, efficient, and conforms to health and safety standards.
The type and characteristics of plant solid waste are the most important
factors in the development of a management system. Non-process and process
wastes exhibit markedly different characteristics and are handled almost entirely
by separate systems, although certain operations, such as disposal, may be
combined.
Non-Process Waste. Plant non-process waste is generally compatible with
municipal refuse, and the decision of whether to use municipal or private
facilities or build plant facilities usually is based on local regulations,
comparative costs, and the adequacy of municipal or private facilities.
The choice of storage, collection, and transportation systems for non-process
waste involves such factors as the length of haul, the number of sources of
waste, and the quantity of waste. In addition, choice of equipment depends
on comparative costs, flexibility, conformance to health and safety guidelines,
ease of maintenance, and compatibility with other plant operations and facilities.
Disposal alternatives are relatively few and are illustrated on Figure 33.
Stone and concrete can be used as clean fill or dumped in a landfill. The
remaining non-process waste can be disposed by landfill or incineration. If
combustible and noncombustible waste Is separated prior to disposal, the glass
and metal waste can be sent directly to a landfill, while garbage, paper, and
wood waste are generally sent to an incinerator. Most chemical plants salvage
certain valuable metal wastes for sale. Other wastes such as paper, glass, and
159
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0)
I— >
^
mmm^mm^^m ••^•^
-^
Land fill
Incineration
Ocean disposal
Deep well disposal
Lagoons or ponds
Receiving waters
j— i
*••
1
• —
i- i
Figure 34. Schematic diagram of chemical plant process solid waste
disposal alternatives.
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wood are capable of salvage but in most cases it is uneconomical and not
practiced. The objectives of national solid waste management plans include
recycling this material. Salvage operators are available in some areas to
take both process and non-process plant wastes for recovery and recyling.
Process Wastes. Solid waste management systems for process wastes require
specialized equipment to handle the variety of waste types. Equipment for
storage, collection, and transporation of process wastes must be designed
for the chemical and physical characteristics of the waste to handle it
efficiently. The same factors that influence the choice of non-process waste
equipment as listed above influence the choice of process waste equipment.
It is of great importance that equipment conform to the intended disposal
method. For example, ocean disposal will require barges; ponds used for
storage must be lined, and will have to be pumped out into tank trucks or
pipelines; and incinerators must be provide/ with storage adequate for the
particular wastes to enable proper feeding and mixing.
If the plant elects to use private or municipal disposal facilities,
they are freed from the task of developing their own. However, certain process
wastes may cause problems with the public or private disposal facility,
resulting in adverse public reaction. There are a number of private disposal
facilities throughout the country, however, that do employ proper disposal
equipment to handle a variety of plant wastes, and where they exist, industries
are inclined to use these private facilities rather than build their own.
The disposal methods for process wastes are more varied than those for
non-process waste, since they depend on the type and characteristics of the
waste to be disposed. Disposal alternatives based on the common waste types
are shown in Figure 34. The method used for disposal of sludge or filter
cake depends on the consistency of the sludge. If it is a heavy sludge with
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low water content, three methods are used: (1) It can be landfilled; (2) It
can be incinerated either in bulk or in fiber drums; (3) It can be dumped in
the ocean either in bulk or in barrels. If the sludge has a high liquid
content or is slurried with water to allow pumping, it can be fired through
a nozzle and burned in an incinerator, pumped aboard barges and disposed at
sea, pumped into lagoons or ponds, or in few cases, pumped into underground
wells. Sludges generated by process waste water treatment may be handled
in a manner similar to other sludges.
Recycling, Utilization, and Recovery of Process Wastes
The best method of handling solid wastes is to use them to perform a
useful function. The industrial chemical industry has a long history of
converting wastes into such useful materials, as evidenced by the many
commercial products of today which were once considered unwanted chemicals.
The large well-staffed research and development departments within many chemical
industries are constantly striving to develop useful products from existing
or potential waste materials. For example, n-butanol was originally an
unwanted byproduct from production of acetone by fermentation. Today it has
many uses, such as in glycol ethers, amine resins, solvents, and n-butyl acetate.
Demand is predicted to be 580 million pounds by 1971. (46) As a further example,
p-toluene sulfonamide was once a residue from production of saccharin. Today it
is a useful material in the plastics industry.
The conversion of a waste to a valuable product has been assisted by
the stability of chemical markets. Once demand is established for a particular
chemical, it generally remains, so when a market is established for a waste,
the waste generally becomes a permanent plant product. This may be in part
why information was not available from the survey on the numbers and quantities
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of waste materials converted to useful products. When a waste is converted
to a product, it is not viewed by industry as a salvaged material or as a
saleable waste, but as a revenue-producing plant byproduct or product.
A benefit is realized from a'waste either by recycling, recovery, or
utilization of the waste. Recycling of a waste involves returning the waste
to the production cycle to be used again. This practice not only reduces or
eliminates unnecessary waste, but also is essential to the economic and
efficient operation of many processes. Some examples of recycling are described
in Section Five. The production of toluene, shown in Figure 7, generates a
still bottom from the final refining column. This material is recycled back
to the primary column, where it is consumed in the process. In the production
of toluene diisocyanate shown in Figure 14, a final fractionating column is
added to remove that portion of the residue containing toluene diisocyanate
and to recycle it back to the second fractionating column to undergo purification
again. In some cases where malfunction in a process results in off-quality
product, it is possible to reprocess the material by recycling it back into
the process. Waste recovery applies to the reclamation of valuable constituents
from waste matter. A prime example is heat recovery from organic waste with
usable BTU values, either by firing directly into power plant boilers or from
incinerators equipped with waste heat boilers.
Another example is the utilization of lime from acetylene manufacture
from calcium carbide. The chemical reaction is as follows:
calcium carbide + water • acetylene + calcium hydroxide
Some of this lime comes from a dry process, but the vast bulk of it is produced
as a 10 percent solids slurry. This slurry is almost invariably pumped to
diked areas where it eventually concentrates to some extent. In recent years,
the number of plants generating acetylene from calcium carbide have decreased,
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but the ponds remained as eyesores. Now, however, they are gradually disappearing
because of the efforts of a New Jersey-based salvage operator who is selling
the waste for acid neutralization. The lime can be converted back to quicklime
by calcination according to the reaction:
calcium hydroxide + heat = calcium oxide + water
The process has never been widely practiced because it is usually cheaper to
buy fresh quicklime than it is to convert the hydroxide.
Recovery of nickel from nickel catalyst used in hydrogenation processes
is an example of extraction of a valuable material from a waste. Spent nickel
catalyst consists of 10 percent nickel and 40-50 percent clay with the remainder
inert. The spent catalyst is sent to Europe where the valuable nickel is
recovered.
Other recovery operations consist of reclamation of contaminated chemicals.
The reclaiming of solvents is a good example of these operations. In many
cases solvents can be reclaimed by simple distillation. Purification or
upgrading of off-quality product waste would also be included.
Utilization of a waste is the act of using the waste to obtain a particular
benefit. The use of flyash in treatment of polluted water, neutralization
of acid mine drainage, and as a binder in soil or roadway conditioning are
good examples of waste utilization. Flyash is also used as a constituent in
concrete or related products, and in conditioning of wastewater sludge prior
to vacuum filtration. However, it has been estimated that only 10 percent
of the flyash generated is utilized to any degree.(63)
Other examples of waste utilization include the use of waste tar from
synthetic alcohol production in the manufacture of bitumen-type binder. A
mixture of bauxite residue and fuel that has been palletized and sintered,
has been used as lightweight aggregate. A relatively unsuccessful utilization
-------
of wastes was the use of red mud generated by alumina production to produce
iron, which turned out too hard, and in manufacture of bricks, which turned
out too soft.
Chemical plant operators are most familiar with the chemical and physical
properties of their waste, and are therefore best able to practice recycling,
recovery, or utilization of the waste. Benefit derived from recycling a waste
into a process must be significant in relation to the total volume of waste
recycled. If a large volume of waste must be recycled to obtain a relatively
small benefit, the process cannot operate efficiently or economically. Two
examples of wastes which would be uneconomical to recycle are wastes from
titanium dioxide production and red mud from alumina production, although these
waste muds and wash waters do contain substantial percentages of titanium dioxide
and aluminum oxide.
Recovery or utilization of wastes by the plant involves possible use in
other processes within the plant, sale to companies dealing in waste salvage,
or sale directly to consumers. The process of finding a market for a waste is
expensive and time-consuming. It is an "extra" task for the marketing staff,
who may not have experience in the necessary marketing area, and storage costs
for the waste are usually high. In addition, the waste may compete with a
customer's product, and too, there is the chance of divulging process secrets
by inference.
There are only a few Independent chemical waste salvage companies operating
in the country, but demand for their services is growing. This type of company
may be in the best position to find and develop markets for chemical wastes.
Their marketing staff is specifically oriented toward this area, and they are
better able to provide consistent and sufficient quantities to their customers.
These firms buy wastes and either process them into saleable materials
or sell them directly. The wastes must generally be obtained from a number of
165
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plants so that their investment in processing equipment and marketing is not
dependent on the operations of one company. Marketing of wastes is hampered
by high storage costs and high freight rates for both shipping and receiving
which increase the final price of the waste product to the consumer. In addition,
some wastes come in quantities that are too small to be attractive, or are
cyclic, prohibiting a continuous market, or their chemical content Is variable,
making it difficult to meet required chemical specifications.
The potential consumers of salvaged waste products are the most important
economic factor in development of markets. Their substitution of salvaged
wastes for production chemicals Is based almost entirely on economics. The
waste must be available at an attractive price, meet chemical specifications,
contain no deleterious impurities, and be available in significant quantities.
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SECTION SEVEN: SURVEY PROGRAM AND RESULTS
Purpose
Approach and Methodology
Development of Questionnaire Format and Survey Plan
Data Analysis
Distribution and Industry-Wide Coverage
Distribution
Industry-Wide Coverage
Discussion
Question 1-General Plant Information
Question 2-Non-Process Solid Waste Quantities and Activities
Question 3-Identification of Process Wastes
Question 4-Quantities and Sources of Process Wastes
Question 5(a)-Storage and Disposal of Process Wastes
Question 5(b)-Cost of Disposal of Process Waste
Question 6-Physical and Chemical Characteristics of Process
Wastes
Question 7-Waste Generation Parameters
Question 8-Five Year Projection as to Waste Quantities,
Disposal Practices and Costs
Plant Visits
Municipal Questionnaire
PART A Municipal Refuse Disposal
PART B Non-Municipal Refuse Disposal
PART C Assessment of Chemical Plant Solid Waste
Page
169
169
169
175
177
177
177
182
182
185
199
199
205
211
215
215
215
215
218
219
220
221
Figures
35 U.S. Public Health Service Regional Designations, 1969 172
36 Mail survey results for mean quantities of non-process waste
distributed by plant-size classification 186
37 Mail survey results for mean quantities of non-process waste
distributed by SIC classification 188
38 Mail survey results for mean quantities of non-process
waste distributed by regional classification 189
39 Mail survey results for mean disposal costs of non-process
waste distributed by plant-size classifications 194
40 Mail survey results for mean disposal costs of non-process
waste distributed by SIC classification 195
41 Mail survey results for mean disposal costs of non-process
waste distributed by regional classification 196
Tables
25
26
Summary of questionnaire response distribution
Distribution of responses to mail questionnaire by plant
size and SIC classification
173
178
167
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Tables
27 Distribution of responses to mail questionnaire by plant
size and geographical classifications 179
28 Mail survey coverage of industrial chemical plants by
region 180
29 Summary of quantities of sludge process wastes (tons per
year) 198
30 Summary of quantities of filter residue process wastes
(tons per year) 200
31 Summary of quantities of tar process wastes (tons per year) 202
32 Comparison of process waste quantities as determined by the
mail and plant visit surveys 204
33 Summary of mail survey responses regarding process waste
storage 206
34 Summary of mail survey responses regarding process waste
transport 208
35 Summary of mail survey responses regarding process waste
disposal 210
36 Summary of mail survey responses regarding process waste
disposal costs 212
37 Summary of mail survey responses regarding process waste
characteristics 214
38 Summary of mail survey responses regarding process waste
generation parameters 216
39 Summary of mail survey response regarding process waste
quantities in 1975 217
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SECTION SEVEN: SURVEY PROGRAM AND RESULTS
This section discusses the purpose, design, and results of the survey
carried out to identify the nature of the solid waste problem in the industrial
chemical industry.
Purpose
The purpose of the survey program was to obtain information directly
from chemical producers as to solid waste quantities, practices, and future
trends, and to relate these, where possible, to basic industry statistics,
manufacturing practices, and historical trends. The information was to be
analyzed on the basis of various industry classifications, plant size categories,
and geographical distributions.
The information was to be obtained by means of a mailed questionnaire
and by direct contact interviews. The latter were intended both to provide a
more detailed understanding of industry solid waste practices, and to assure
that the mail survey was providing representative information.
Secondary objeccives of the survey program included the identification
of information gaps, and the formulation of recommendations for action leading
to their elimination.
Approach and Methodology
Development of Questionnaire Format and Survey Plan. Pilot Program. A
pilot program of plant visits was conducted in the early months of the study.
This program was primarily intended to solicit industry participation in the
structuring of mail and Interview questionnaires and formats. The pilot program
169
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included contact with the individuals responsible for environmental activities
at the corporate level for each plant visited. The Manufacturing Chemists
Association provided valuable assistance in making the necessary contacts. Five
plants were visited.
The pilot program resulted in many suggestions and comments concerning
the content and structure of the questionnaires. Among these were strong warnings
against questions relating to plant production and fiscal matters. These, if
asked, would not be answered and would very likely prevent any response at all.
Other valuable information obtained through the pilot program included suggested
process waste categorizations, and the recommendation that the same questionnaire
be used for both the mail and plant visit portions of the survey.
After the pilot program was complete and the results reviewed with the
Federal program, the questionnaires were finalized for approvals. Samples of
both questionnaires are included herein for reference. In addition to the
industry questionnaire, a brief questionnaire for mailing to municipal solid
waste officials was also prepared. (See Municipal Questionnaire.) The approvals
of the questionnaires from the Bureau of the Budget required far more time than
was anticipated. The six week delay initially projected stretched to four months.
Survey Mailing. Based on 1967 industry statistics, there were 2,030
establishments engaged in the manufacture of industrial chemicals (SIC 281) in
the United States. Project officials intended to mall the Industry survey
questionnaires to as many of them as possible. The mailing list was developed
from the Stanford Research Institute's (SRI's) Directory of Chemical Producers.(20)
This directory does not segregate listings according to SIC classifications, so
that the products produced by each plant listed had to be checked against those
listed for SIC 281. This procedure involved considerable judgment. The address
list developed provided over 2100 establishments.
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The mailing list for municipal questionnaires was developed on the basis
of the geographical distribution of the industry, the distribution of
establishments to be sent questionnaires and from readily available listings of
municipal officials, such as the Municipal Index, published by the Buttenheim
Publishing Corporation.
There were no particular difficulties in preparing the lists or the
questionnaires for mailing. Each questionnaire was coded with an identification
number to aid in its subsequent classification if it was returned without the
plant name and address. No attempt was made to obtain specific names of plant
officials. The mailing was addressed to "Plant Manager" in all cases. The
identification number indicated the region in which the plant was located to
facilitate subsequent data analysis. The regions chosen for this analysis were
the Public Health Service Regional Designations of 1969, shown in Figure 35.
They were chosen to allow easy comparison of this study data with that developed
through other studies conducted by the Public Health Service.
Responses arrived almost immediately, primarily from the small plants.
These firms were apparently not constrained by extensive review and approval
procedures. In many cases, the company president completed the questionnaires.
Many of the larger corporations which replied required several months, and
frequently the replies from the various plants arrived in sizable groups,
indicating that a general corporate release had been granted. The mail strike,
which occurred shortly after the mailing, had little effect.
Table 25 summarizes the distribution of responses before processing.
As expected, because of the judgments applied to the SRI Director, many responded
negatively in terms of "Not SIC 281". In addition, a surprisingly high number
were initially returned because of "insufficient address" or "moved-forwarding
address unknown", etc. Even though some attempt was made to correct addresses
and remail these, a significant number of the mailings remained in this category.
171
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•i vi i
Dakota
South
Dakota
I.J.
Delaware
Maryland
D.C.
Figure 35, U.S. Public Health Service Regional Designations, 1969.
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TABLE 25
SUMMARY OF QUESTIONNAIRE RESPONSE DISTRIBUTION
No. of plants
receiving
Region questionnaire
I & II 491
III & IV 389
V & VI 414
VII 346
VIII & IX 318
Totals: 1,958
No. of mall ques-
tionnaires coded Plant *Response
for processing visits percentage
64 7
48 5
44 5
35 6
34 5
225 28
13.0
12.3
10.6
10.1
10.7
11.5
No. of mall questionnaires
coded for processing
^Response percentage +
No. of plants receiving
questionnaire
X 100
173
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There were originally over 2100 plants on the mailing list, but approximately
forty were held back because these were candidates for plant visits. Table 25
shows that a remarkably consistent response percentage was obtained throughout
the country. The overall response rate of about 12 percent was considered
satisfactory, although the original goal was 15 percent or better. Some
multlplant corporations limited their total number of responses, thereby
depriving the survey of responses where they had been expected.
Plant Visit Survey. Since the purpose of the plant-visit portion of
the survey program was largely to support and confirm the findings of the mail
survey, it was considered vital that the visit ditribution provide a representative
cross-section of the industry.
The geographic distribution of the visits was designed to match the
questionnaire mailout distribution as closely as possible. Table 25 shows that
this end was reasonably achieved. Only regions 1, VI, and VIII were not covered
by plant visits, as these regions account for only about 12 percent of the total
number of questionnaires mailed. The ratio of plant visits in each region to
total plant visits when compared to the ratio of questionnaires mailed in each
region to total questionnaires mailed, shows agreement.
In selecting the plant-visit distribution, an attempt was also made to
account for likely variations due to plant size and area of chemical manufacture.
Total plant employment was selected as the size parameter, and four digit SIC
classification (SIC 2812, 2813, 2815, 2816, 2818, and 2819) as the area of
manufacture category. Four plant size classifications were used: small (less
than 100 employees), medium (100 to 500 employees), large (500 to 1,000
employees), and extra large (more than 1,000 employees).
The desired combinations of size, SIC classification, and geographic
location were initially developed based on random selection. Then, these were
174
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adjusted during conferences with the Federal program, and finally adjusted to
reflect the realities of which plants were willing to be visited and when.
Originally the candidates for the visits were restricted to regions II, V,
and VII, the regions most active in chemical manufacture, and were to be limited
to a total of 24, including the pilot program. Economies in travel expenses
permitted the expansion of the visits to include California (region IX), and
scheduling difficulties led to the visits in regions III and IV.
During the pilot program, a few visits were made to municipal agencies
in the areas of the chemical plants visited and these are reported on later in
this Section. The information obtained was of limited value; thus these visits
were discontinued during the balance of the plant-visit program.
Data Analysis. Data processing was structured for computer techniques.
A coding form was developed which transferred the "raw" questionnaire replies
into a format amenable to keypunching. The coding of
the entire complement of usable replies was accomplished by the same individual,
thereby assuring a consistency of interpretation and judgment in those areas
where subjective aspects were involved. This same individual was also involved
in most of the plant visits.
There were no particular difficulties in coding the replies. The only
replies not coded were those from plants not under SIC 281 or those which
answered little or none of the questions on the form. In some cases, the
numerical replies seemed somewhat inconsistent; e.g., large waste tonnage for
small or medium-sized plants. Attempts were made to check the validity of the
responses by analyses of the processes involved and other means. It was decided,
however, not to make contact with Individual plants since if a few plants were
called, expecially those generating large waste quantities, this could bias the
data. In most cases a reply was accepted at face value, with only occasional
responses discarded due to obvious errors.
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Since we did not ask each plant to identify its applicable plant SIC
number, which would have meant including a detailed list of SIC numbers and the
products they included and thereby increasing the complexity of the questionnaire,
TRC assigned the appropriate SIC numbers to the questionnaire returns. Assignment
of SIC number was based on process wastes reported on the questionnaire and
data for the plant found in the SRI directory.
Since only 225 individual questionnaires were coded, it was decided
Jointly with the Federal solid waste management program not to program for
response analysis on the basis of complete combinations of four plant size
categories, six SIC classifications, and nine geographic regions. This practice
would lead to 216 combinations for each question, with about an equal number of
total replies. Most combinations would have registered either zero replies or
such a low number as to preclude any conclusions. It was therefore decided
to consider the combinations on the basis of three arrangements. Plant size
would be considered Jointly with SIC classification (24 combinations). The
geographical variations were reduced to five by combining regions I and II,
III and IV, V and VI, and VIII and IX. These geographical areas were then
analyzed with the six SIC classifications (30 combinations) and then with the
four size classifications (20 combinations; total of 74).
The 28 plant visits were coded and processed by the computer program in
the same manner as the mail responses. This decision was intended to permit
comparisons which might point to inconsistencies in the mail survey results.
Because of the small universe involved in the plant visits, only gross comparisons
were possible. Samples of the computer printout for the mail survey responses
are included in the appendix.
Data analysis is discussed in detail later in this Section. In general, many
combinations of size, SIC classification, and geographic region resulted in too
176
-------
small a response to permit analysis (i.e., small plants in region V of SIC #2818;
large plants in region I of SIC //2815; etc.). In many cases, meaningful comparisons
were possible only with the gross results (i.e., all small plants vs. all medium
plants; all SIC 2812 plants vs. all 2816 plants; etc.).
There were some comparatively high individual solid waste tonnages reported
which greatly influenced the mean calculated for the particular response
categories. In most cases, scrutiny of the questionnaire from which the value
was derived indicated that the reply was valid as provided by the respondent. In
these cases, although the standard deviation and mean calculated for the response
showed that the high value was clearly inconsistent with the rest of the individual
values, there was no choice but to accept the response. To arbitrarily delete
it because "it looked too high" would introduce an unwarranted bias in the results.
Distribution and Industry-Wide Coverage
Distribution. The distribution of responses to the mail questionnaire
is summarized in Tables 26 and 27. These tables illustrate the overall
"processed" response; that is, 225 responses were processed to the extent that
their major areas of activity were assigned (by SIC classification). The
distributions shown do not represent responses to all questions on the
questionnaire. For example, replies to Question //2 totaled 203 for quantities
of combustible waste, 179 for quantities of noncombustible waste, and 144 for
quantities of salvageable metal.
As a further example, replies to Question //4 gave 131 responses for
quantitites of sludge process waste, 72 for quantitites of filter residue process
waste, 37 for quantitites of tar process waste, 19 for quantities of flyash
process waste, 24 for quantities of off-quality product process waste, and 30
177
-------
TABLE 26
DISTRIBUTION OF RESPONSES TO MAIL QUESTIONNAIRE
BY PLANT SIZE AND SIC CLASSIFICATION*
Classification
Small plants (0-100 emp.)
Medium plants (100-500 emp.)
Large plants (500-1000 emp.)
Extra large plants (more than
SIC 2812
Small plants
Medium plants
SIC 2813
Small plants
Medium plants
SIC 2815
Small plants
Medium plants
Large Plants
Extra large plants
SIC 2816
Small plants
Medium plants
Extra large plants
SIC 2818
Small plants
Medium plants
Large plants
Extra large plants
SIC 2819
Small plants
Medium plants
Large plants
Extra large plants
Number of
responses
136
61
14
1000 emp.) 14
225
14
8
6
36
34
2
31
13
8
7
3
4
2
1
1
49
24
15
2
8
91
55
29
5
2
225
Percentage
60.4
27.0
6.3
6.3
100.0
6.3
16.0
13.0
1.7
21.8
40.4
100.0
^Processed responses only.
178
-------
TABLE 27
DISTRIBUTION OF RESPONSES TO MAIL QUESTIONNAIRE
BY PLANT SIZE AND GEOGRAPHICAL CLASSIFICATIONS*
Classification
Regions I & II
Small plants
Medium plants
Large plants
Extra large plants
Regions III & IV
Small plants
Medium plants
Large plants
Extra large plants
Regions V & VI
Small plants
Medium plants
Large plants
Extra large plants
Region VII
Small plants
Medium plants
Large plants
Extra large plants
Regions VIII & IX
Small plants
Medium plants
Number
responses
64
31
21
5
7
48
31
10
6
1
44
27
13
2
2
35
22
8
1
4
34
25
9
225
Percentage
28.4
21.3
19.6
15.6
15.1
100.0
^Processed responses only.
179
-------
TABLE 28
MAIL SURVEY COVERAGE OF INDUSTRIAL CHEMICAL PLANTS BY REGION
Region
On basis of
plants with 20
or more employees
percent
On basis of
value added
by manufacture
percent
Regions I & II
Regions III & IV
Regions V & VI
Regions VII
Regions VIII & IX
17
15
11
15
16
11
19
10
25
9
Overall
14
14
180
-------
for quantities of other process wastes. Thus a total of 333 responses were
received concerning quantities of process wastes.
Further detail Is presented later In this Section where the responses
to individual survey questions are analyzed.
Industry-Wlde Coverage. Comparison of Table 9 with Table 26 gives an
Indication of the depth of coverage of the survey response. In the medium,
large, and extra large categories, the response percentage exceeded the census
percentage, while in the small plant category, it fell substantially short.
These figures are perhaps indicative of the greater awareness of environmental
problems on the part of the larger plants. Thus, while the survey provided a
12 percent overall sample, it gave a 29 percent coverage of the extra large
plants, a 24 percent coverage of the large plants, and a 19 percent coverage
of the medium plants. The small plants were represented only to the extent
of 8.5 percent, however.
In SIC 2812, the response covered 32 percent while in SIC 2813 It covered
7 percent. For SIC 2815, the response provided an 18 percent coverage, while
in SIC 2816, only a 4 percent coverage was achieved. In SIC 2818, the coverage
was 10 percent, and in SIC 2819, it was 13 percent.
Table 42 of the appendix gives the value added by manufacture in 1967,
by geographical region and for plants with 20 or more employees. There is no
precise way to determine which of the 136 small plant responses to the survey
employ more than 20 persons. However, if there are 1600 total establishments
with less than 100 employees, 2030 total establishments and 989 establishments
with more than 20 employees, there are 35 percent (100[1 - 2030 - 989/1600] =
35 percent) of the plants in the 0-100 employee category who have more than 20
employees. If it is assumed that 35 percent do indeed have this characteristic,
then the survey response on a geographical basis is as shown in Table 28.
181
-------
In general, therefore, it appears the survey provides an adequate
coverage of the industry in terms of the plant size, SIC, and geographical
categories selected. Analysis of the data obtained during the 28 plant visits,
when compared to those obtained from the mail survey, pointed up no significant
deviations or contradictions. Thus the findings of the plant visits are
considered to have confirmed the results of the mail survey response. Further
details will be provided later in this Section.
Discussion
This Section will provide a question by question analysis of the survey
response.
Question 1-General Plant Information.
Total plant employment. The response to this question is summarized in
Table 26. While the response came largely from "small" plants (60.4 percent),
this figure fell short of the census of small plants (79 percent), while the
responses in the other categories exceeded census figures. This matter was
discussed in more detail previously in this Section.
Size of Plant Site. The average plant surveyed by mail occupied 199
acres, of which 44 percent was devoted to production facilities. The responses
ranged from one acre to 3,917 acres. The average acreage increased significantly
with the plant-size category (employment), ranging from 49 acres for small plants
to 823 acres for the extra large plants. The extra large plants utilized a
higher percentage (52.3 percent) of the plant area for production. SIC 2812
and 2813 plants occupied smaller average plant sites (76 and 69 acres, respectively^
than SIC 2815, 2818, and 2819 plants (252, 291, and 205 acres). The SIC 2816
response was too small for meaningful conclusions.
182
-------
All plant size categories in all SIC's exhibited considerable variability
in plant-site size. Even in SIC 2818, for extra large plants, the plant-site
size response ranged as low as 20 acres and as high as 3,917.
In all plant sizes, regions I and II and regions VIII and IX have plants
whose acreage is less than the average and which have a higher percentage of
plant area devoted to production facilities. For example, for medium plants in
regions I and II, 19 responses averaged 91 acres, whereas the overall average
for 57 medium-sized plants is 266 acres. Overall, regions I and II plants
devote 48.5 percent of plant area to production facilities, while in regions
VIII and IX, the figure is 57 percent.
In many cases, for subdivision into a specific SIC and plant size or a
specific geographic region and plant size, there were insufficient responses to
permit analysis.
The plant visit survey plants occupied an average site of 1,041 acres,
ranging from 4 to 7,300 acres. A mean of 52.6 percent was devoted to production
facilities. The visits surveyed a higher (63 percent) percentage of medium,
large and extra large plants, which accounts for the larger value. The tendency
for regions I and II and regions VIII and IX plant sizes to be smaller than the
mean was supported by the plant visit data.
Nature of Area Surrounding Plant Site. For the mail survey, 41 percent
of the responses indicated that the surrounding area was rural, 21 percent said
it was residential, 32 percent said it was urban, and 6 percent gave other
responses.
For regions I and II the surrounding area was 22 percent rural, 27 percent
residential, and 44 percent urban. The higher concentration of plants in urban
areas may partially explain why regions I and II exhibit a small average plant
site and greater area devoted to production facilities. Many of the plants in
183
-------
this region are located in the highly developed New York-New Jersey metropolitan
area. In addition, many of the plants are old and have expanded over considerable
portions of their original plant site.
There was no significant deviation from the above mean values in the
various size and SIC classifications. The plant visit survey showed fewer plants
surrounded by rural (21 percent) and more (36 percent) by residential areas.
These figures may be accounted for by the low percentage of small plants visited,
although there was no clear indication from the mail survey that small plants
were more usually surrounded by rural areas.
Does the Plant Use Public Solid Waste Disposal Sites? Those plants
surveyed by mail indicated that 42 percent used public solid waste disposal
sites, while 58 percent did not. This response was almost precisely verified
by the plant visit survey. The mall survey indicated that small plants (44 percent)
and extra large plants (64 percent) used the public waste disposal sites most,
while the medium (36 percent) and large (29 percent) used them the least.
SIC 2812 plants used them the most (71 percent), and SIC 2813 plants used them
the least (31 percent), followed closely by SIC 2819 plants (36 percent). The
rest of the SIC classifications were quite close to the overall response.
Plants located in regions I and II and VIII and IX use public sites most
(55 percent and 56 percent), while those in regions V and VI, and VII use them
the least (33 percent and 23 percent). Plants in regions I and II have indicated
a low mean plant site acreage and a high percentage of plant location in urban
areas. These figures are consistent with their greater use of public waste
disposal sites. Urban areas have fewer land areas suitable for disposal and
strict land use regulations which prohibit disposal operations in most areas.
In regions VIII and IX, the greater use of public sites is probably due to the
highly effective public solid waste disposal systems, although the plants in
184
-------
these regions indicated a much higher degree (46 percent) of rural land
surrounding them.
Are There Local, Regional, or State Regulations in Effect That Govern
Your Solid Waste Activities? The plants surveyed by mail indicated that 69 percent
were governed by solid waste regulations and 31 percent were not. In the plant
visit survey, the corresponding figures were 96 percent and 4 percent. Ninety
percent of the aggregate of the medium, large, and extra large plants in the mail
survey indicated that they were governed by regulations, compared to only
55 percent of the small plants. This seems to imply that regulations do exist
in most cases, but that about half of the small plants are not yet aware of them.
There were no significant deviations from the overall 69 percent to 31 percent
yes-no response in the SIC and geographical classifications.
Question 2-Non-Process Solid Waste Quantities and Activities.
Non-Process Solid Waste Quantities. The respondents were asked for
annual quantities of non-process solid waste, either measured or estimated.
Ninety-eight percent of them replied that the quantitative information provided
was based on estimated rather than measurements. For the plant visit survey,
14 percent indicated that their information was based on measurements.
The results for quantities of non-process solid waste as determined by
the mail survey are illustrated by Figures 36, 37, and 38. These figures are
bar charts of mean quantities of combustible and noncombustible wastes and
salvageable metal, distributed according to plant size, SIC, and geographic
classifications. Because of the extremely wide range of the average responses,
the charts are constructed on a three-cycle logarithmic scale. While this
negates some of the physical "feel" normally associated with bar charts, it
was considered necessary to present the Information as accurately and concisely
as possible.
185
-------
10,000
5,000
1,000
Overall mean
combustibles
(203 replies) 500
Overall_mean
noncombustibles
(178 replies)
100
Overall mean
salvageable metal
(144 replies)
i. 50
S Combustibles
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Figure 36. Mall survey results for mean quantities of non-process
waste distributed by plant-size classification.
-------
Figure 36 presents the mail response for non-process waste quantities
distributed according to plant-size classification. The mean annual tonnage
for combustible is seen to range from 37 tons for small plants to 5,340 tons
for extra large plants. The overall mean for combustibles is 562 tons per year.
The corresponding figures for the plant visit survey were 113, 6,580, and 2,820
tons per year. The higher values for the plant visits are again due to the
preponderance of larger plants in the visit program.
For noncombustibles, the overall mean is 207 tons per year, and the
relationship of increasing waste quantities with increasing plant size (employment)
is evident, ranging from 56 tons for small plants to 1,330 tons per year for the
extra large plants. The corresponding figures for the plant visit survey were
95 and 2,180 tons per year, with an overall mean of 1,040 tons per year.
Salvageable metal quantities are generally lower (overall mean of 89 tons
per year) with less of a variation due to plant size. The range is from 61 to
264 tons per year for the small to extra large plant-size categories, respectively.
One response from a small plant indicated an annual salvageable metal quantity of
3,620 tons. When this figure is deleted, the overall mean drops to 64 tons per
year, and for small plants, it is reduced to 10 tons per year. The plant visit
survey provided much higher salvageable metal results, ranging from 42 tons for
small plants to 3,670 for extra large plants. The overall mean was 1,270 tons
per year.
Figures 37 and 38 present the non-process waste quantities distributed
according to SIC and geographical classifications. In general, SIC classifications
2812 and 2813 (alkali and chlorine and industrial gases, respectively) exhibit
lower non-process waste quantities, due to the preponderance of small and medium
plants in the response in these categories. Regions VIII and IX exhibit lower
quantities for the same reason, while conversely regions I and II exhibit higher
waste quantities because of the large and extra large plants participating in
the response.
187
-------
10,000
5,000 —
1,000 _
Overal1 mean
combustibles
(203 replies) 500
0_ye_ral l_me_aj!
noncombustibles
(178 replies)
100
Overall mean
salvageable metal
(144 replies)
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Flgtire 37. Mail survey results for mean quantities of
non-process waste distributed by SIC classification.
-------
10,000
_ 9 _ _ _
5,000
1,000
Overal 1 mean
combustibles
(203" replies) 500
Overall mean
noncombustibie
(178 replies)
100
Overall mean
salvageable metal
(144 replies)
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Number of replies 615641 444Q34 413525 3° 2426 27 2318
Regions IftH IllftlV V&VI VII VIIWIX
Figure 38. Mall survey results for mean quantities of
non-process waste distributed by regional classification.
189
-------
Analysis of responses to consider detailed combinations of plant-size
categories and SIC classifications, or plant-size categories and geographical
classifications was not considered plausible because of the small numbers of
responses Involved.
Non-Process Solid Waste Activities. A number of questions were posed as
part of Question 2 relating to waste sources, means and duration of storage,
ultimate disposal sites, methods, and costs.
...Waste Sources. On an overall basis, the mail survey respondents
indicated that 51 percent of their combustible waste, 42 percent of their
noncombustible waste, and 33 percent of their salvageable metal originated in
nonproduction areas. Deviations from these mean values for the various plant
sizes, SIC, geographical classifications, and combinations thereof were generally
not significant. The plant visit survey confirmed the above results with
reasonable accuracy (57 percent, 47 percent, and 26 percent respectively).
...Storage Type. Type of storage for combustible non-process waste was
reported by the mail survey as 55 percent bulk storage, 4 percent compaction,
and 22 percent casual storage. Sixteen percent reported the use of multiples
of the above storage methods, while the remaining 3 percent indicated the use
of other means. The corresponding values for noncombustible non-process waste
were 52 percent, 3 percent, and 27 percent for bulk, compaction, and casual
storage; 15 percent for multiple methods; and 7 percent, other means. Thus there
was little difference in storage types for non-process waste, whether combustible
or noncombustible. For salvageable metals, 35 percent Indicated bulk storage
and 51 percent casual storage, while 10 percent reported multiple methods and
4 percent other means.
Large and extra large plants showed less combustible non-process waste
stored casually and greater use of containerized systems than smaller plants.
-------
Large plants reported 75 percent bulk storage, 17 percent multiple-storage type
systems, and only 8 percent casual storage of combustibles. Extra large plants
reported only 38 percent bulk storage, but 15 percent compaction and 46 percent
multiple-storage systems. No single extra large plant reported all casual
storage. Larger plants probably require more efficient storage and collection
systems to handle their greater combustible waste quantities and are able to
justify purchase of efficient waste storage and collection equipment.
This relationship does not apply to noncombustible non-process waste,
and large and extra large plants indicate higher bulk storage of these wastes
(83 percent and 69 percent, respectively) than they do for combustibles.
...Storage Period. Overall mean storage period for non-process waste
varied from 10 days for combustibles and 22 days for noncombustibles to 119
days (4 months) for salvageable metals. There was little deviation from the
above mean values for small and medium plants, but the large and extra large
plants had substantially shorter periods. For combustible waste, these storage
periods were 3 and 1.5 days, respectively, and for noncombustibles, they were
4 and 2 days. For salvageable metals, the large plant storage period was 78
days, and for the extra large plants, 34 days.
Significant variations with respect to SIC classification, geographical
location, and combinations thereof with plant size were few, but Included the
following:
SIC 2813; Fourteen small plants reported an average storage
period of 50 days for noncombustibles.
SIC 2815; Ten small plants reported an average storage
period of 7 days for noncombustibles.
SIC 2813; Eleven small plants reported an average storage
period of 260 days for salvageable metal.
Ill
-------
The SIC 2813 plants (industrial gases) are generally small, with very
low non-process waste quantities. Since quantities are low, longer storage
periods are to be expected. There Is no apparent reason for the short storage
period for the ten SIC 2815 plants. The plant visit survey resulted In longer
mean storage periods for combustible and noncombustlble wastes (45 and 59 days,
respectively) and a shorter period for salvageable metal (89 days).
...Ultimate Disposal Site and Agency. Overall, 35 percent and 33 percent
of the mall survey respondents Indicated that their combustible and noncombustlble
wastes are disposed onslte, the balance offsite. The plant visit survey confirmed
the overall results for the combustible wastes, but Indicated a higher (46 percent)
disposal onslte for noncombustlbles.
For combustible waste, 52 percent of the offsite disposal takes place at
government-operated facilities, 44 percent at private facilities, 2 percent
at captive operations, and 2 percent at several of these. For noncombustlble
wastes, the corresponding results are 47 percent government, 50 percent private,
2 percent captive, and 1 percent multiple. The plant visit survey Indicated
an even 50-50 split between government and private facilities for both combustible
and noncombustible waste.
Except for SIC 2812, there is little deviation from the foregoing mean
values when consideration is given to combinations of plant size, SIC
classification, and geographic location. In SIC 2812 (alkali and chlorine),
six plants replied that 86 percent of their combustible and 71 percent of their
noncombustible wastes are disposed at government-operated facilities.
...Ultimate Disposal Method. Overall, according to the mail survey,
combustible non-process wastes are disposed of as follows: 43 percent in
landfills, 25 percent in incinerators, 13 percent in dumps, 5 percent by open
burning, and 14 percent by other methods. Noncombustibles are disposed of
73 percent in landfills, 13 percent in dumps, and 14 percent by other methods.
-------
On the plant visit survey, 75 percent reported the use of landfills for
combustibles, 18 percent incinerators, and 7 percent open burning. Landfill
was the only method reported for noncombustibles.
The large and extra large plants reported a slightly higher than overall
average use of incinerators (36 percent), but there were generally no significant
deviations from the overall mean in the various SIC and geographical classifications
or in their combinations with plant size. However, regions VIII and IX reported
a somewhat higher percentage of use of landfill for both combustible (59 percent)
and noncombustible (89 percent) non-process wastes. These figures may be related
to the high percentage of plants (45.5 percent) reported in rural areas, and
the strict air pollution control regulations in California.
...Cost of Disposal. The mean cost of disposal of combustible non-process
waste, according to the mail survey, was $32.80 per ton. This cost includes
collection costs and deducts any applicable credits. For noncombustibles, the
mean cost was $23.80 per ton, and for salvageable metals there was a $43.80
per ton (approximately $.02 per Ib.) credit.
The results for disposal costs and non-process wastes as determined by
the mail survey are illustrated by Figures 39,40, and 41.
When the mail response for non-process waste disposal costs was distributed
according to plant-size classification, the mean disposal cost for combustibles
was seen to range from $38.20 per ton for small plants to $18.60 per ton for
large plants (Figures 39 to 41). There is a decreasing per-ton cost with
increasing plant size for the small, medium, and large plants, but the trend
reverses for extra large plants, indicating possibly a more sophisticated (and
more costly) disposal system for these very large plant complexes.
For noncombustibles, the mean disposal cost ranges from $31.60 per ton
for extra large plants to $17.80 for large plants. Small plant disposal cost
193
-------
5U
45
40
35
Overall mean
combustibles
(145 replies)
30
25
Overall mean
noncombustlbles
(126 replies)
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Number of replies
79 66 44 39
Small
plants
(0-
100
EMP)
Medium
plants
(100-
500
EMP)
9 9
Large
plants
(500-
1000
EMP)
13 12
Extra-
large
plants
( 1000 EMP)
Figure 39. Mail survey results for mean disposal costs of
non-process waste distributed by plant-size classifications.
-------
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combustibles
(145 replies)
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noncombustibles
(126 replies)
to
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-------
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ns I&II III&IV V&VI VII VIII&IX
-------
is about the same as that for medium plants. Figure 39 shows that disposal costs
for combustible vs. noncombustible non-process waste are essentially the same
except for small plants.
Figures 40 and 41 present the non-process waste disposal costs distributed
according to SIC and geographical classifications. Except for SIC 2816, where
only two responses were obtained, the deviations from the overall mean in the
SIC classifications are not significant.
In the regional classifications, the mean combustible disposal cost for
regions III and IV was above the overall mean at $45.10 per ton, as was the cost
for region VII which was $48.50 per ton. The noncombustible disposal cost for
region VII was $46.50 per ton. The balance of the geographical distributions.
were not significantly different from the overall means. Regions III and IV,
and region VII comprise the southern states. Longer hauling costs to off-premise
disposal sites could be the predominant factor in these cases, as could difficulties
in landfilling due to high water tables and poor soil conditions (e.g., Louisiana
and Texas). In most cases, extensive analysis of responses to consider detailed
combinations of plant size categories and SIC classifications, or plant size
categories and geographical classifications was not considered because of the
small numbers of responses Involved. There were, however, some exceptions as
listed below:
SIC 2815; Eight small plants reported an average disposal
cost of $79.10 per ton for combustibles.
Regions V and VI; Eight medium plants reported an average
disposal cost of $11.60 per ton for combustibles. Six medium
plants reported an average disposal cost of $7.30 per ton
for noncombustlbles.
197
-------
Regions I and II; Eight SIC 2815 plants reported an average
disposal cost of $14.60 per ton for combustibles, and $11.60
for noncombustibles. Eight SIC 2818 plants reported an
average of $9.20 per ton for combustibles and $9.70 per ton
for noncombustibles.
Region VII; Eleven SIC 2818 plants reported an average of $57.60
per ton for combustibles.
The reasons for the above variations from mean values are difficult to
pinpoint. Earlier in this Section, a short, seven-day average storage period
for ten small plants in SIC 2815 was indicated. This figure would account in
part for the high disposal cost indicated above for SIC 2815, since more frequent
pickups mean greater costs. The regional variations seem to point to hauling
costs as the reason for large differences. Hauling distances are likely to be
higher in regions III and IV, and in region VII, and smaller in regions I and
II.
For the plant visit survey program, the mean disposal costs for combustible
and noncombustible non-process waste were $41.20 and $18.50, respectively,
which compare reasonably well with overall means obtained in the mall survey.
However, the seven extra large plants surveyed indicated a mean disposal cost
of $19.20 for combustibles, which is substantially below the mean and contradicts
the mail survey results which showed the extra large plants at approximately
the mean value. However, six of the seven plants visited were in regions I and
II and in regions V and VI, which in the mail survey exhibited the lowest mean
disposal costs for extra large plants.
With respect to salvageable metals, only 18 plants replied to this portion
of the mail survey, most of them in SIC 2819. With this size of overall response,
it is not possible to analyze beyond the mean value of $43.80 per ton credit
-------
reported. In the plant visit survey, only two replies were obtained, averaging
$54.50 per ton credit.
Question 3-Identification of Process Wastes. The respondents were asked
to identify the number of different process solid wastes which are handled at
their plants. They were asked to select from the categories: sludges, filter
residues, tars, flyash, off-quality product, and other. For the 213 responses
obtained, the average plant generated 1.5 different types of process waste. The
small plants averaged 0.9; the medium plants, 2.3; the large plants, 3.2; and
the extra large averaged 2.5 different process wastes. Regional and SIC
classifications and combinations did not exhibit appreciable variations.
Question 4-Quantities and Sources of Process Wastes.
Sludges. Table 29 summarizes the 131 mail survey responses which indicated
quantities of sludge process wastes. The responses ranged from 1 ton per year
to a high of 1.67 million tons per year. (This latter response was checked and
found to be valid.) The overall mean, and the means for medium plants, for
region VII, and for SIC 2819 are all significantly influenced by this value.
If it were discounted, the results would be as listed in parentheses on Table 29.
The medium plant, region VII, and SIC 2819 values would still be substantially
above the mean indicating other high response values in these categories. There
were 21 medium plant responses in SIC 2819 which averaged 138,000 (61,000) tons
per year, and six SIC 2819 responses in region VII which averaged 448,000
(204,000) tons per year. Thus it appears that sludge waste quantities are
significantly larger in the responses from medium plants, from SIC 2819, and from
region VII, than they were in other categories. On an individual response basis,
there are several plants in this region which manufacture chemicals through
processing of ores which leads to extremely large waste quantities.
199
-------
TABLE 29
SUMMARY OF QUANTITIES OF SLUDGE PROCESS WASTES (TONS PER YEAR)
Plant size
classifi-
cation
All
Small
Medium
Large
X-Large
All
All
All
All
All
All
All
All
All
All
All
SIC
classi-
fication
All
All
All
All
All
All
All
All
All
All
2812
2813
2815
2816
2818
2819
Geographical
classification
All
All
All
All
All
Reg. I & II
Reg. Ill & IV
Reg. V & VI
Reg. VII
Reg. VIII & IX
All
All
All
All
All
All
No. of
replies
131
52
42
23
14
41
23
26
16
25
16
11
18
5
25
56
Mean
responses
*25,400 (12
2,000
*69,400 (30
11,700
2,570
3,470
7,450
6,870
*169,000 (69
4,760
1,740
1,180
1,090
2,890
919
*57,600 (28
,700)
,400)
,400)
,300)
*These include the single high responses of 1.67 x 10(6) tons per
year. The value in parentheses deletes this high response.
-------
Filter Residues. Table 30 summarizes the 72 mail survey responses which
indicated quantities of filter residue process wastes. The responses ranged
from one ton per year to a high of 3.0 million tons per year. The overall
mean, and the means for medium plants, for region VII, and for SIC 2819 are all
significantly influenced by this high value. If it were discounted, the results
would be as listed in parentheses on Table 30. In this case, the consistency
obtained by deleting the 3.0 million value indicates that it was the only response
of this order of magnitude. In checking the individual questionnaire which
gave this response, it was found that the waste was solids (gypsum from the
filtration of phosphoric acid). Thus in spite of its drastic bias of the results
for filter residue wastes, it appears to be a valid response. If it is discounted,
then the filter residue waste quantities predominate in the responses from
SIC 2819 and from small and medium plants and regions VIII and IX where again
i
several high responses for plants processing ores influenced the mean results.
Tars. Table 31 summarizes the 37 mail survey responses which indicated
quantities of tar process wastes. With this number of overall responses, it is
apparent that even at the level of subdivision of Table 31, analysis of some
combinations is not possible. The mean responses for tar waste quantities are
seen to be quite consistent, with no significant deviations from the overall
mean value. As expected, the tar wastes are generated almost entirely from
SIC's 2815 and 2818 (organic chemicals), and largely in region VII which
predominates in organic chemical production as shown in Figure 4.
Flyash. Only 19 of the 313 process wastes accounted for by the mail
survey response indicated quantities of flyash. These responses averaged
21,830 tons per year per reply, and ranged from 150 to 160,000 tons per year
of flyash. The small size of the responses precludes any discussion regarding
distribution among plant size, SIC, and geographical classifications.
201
-------
TABLE 30
SUMMARY OF QUANTITIES OF FILTER RESIDUE PROCESS WASTES (TONS PER YEAR)
Plant size
classifi-
cation
All
Small
Medium
Large
X-Large
All
All
All
All
All
All
All
All
All
All
All
SIC
classi-
fication
All
All
All
All
All
All
All
All
All
All
2812
2813
2815
2816
2818
2819
Geographical
classification
All
All
All
All
All
Reg. I & II
Reg. Ill & IV
Reg. V & VI
Reg. VII
Reg. VIII & IX
All
All
All
All
All
All
No. of
replies
72
29
34
6
3
33
15
10
4
10
4
1
7
0
25
35
Mean
Responses
*42,900 (1,206)
1,040
*89,700 (1,544)
576
370
1,200
198
287
*750,000 (184)
3,920
49
6
447
0
193
*87,900 (2,280)
*These include the single high response of 3.0 x 10(6) tons per year.
The value in parentheses deletes this high response.
-------
TABLE 31
SUMMARY OF QUANTITIES OF TAR PROCESS WASTES (TONS PER YEAR)
Plant size
classifi-
cation
All
Small
Medium
Large
X-Large
All
All
All
All
All
All
All
i
All
All
All
All
SIC
classi-
fication
All
All
All
All
All
All
All
All
All
All
2812
2813
2815
2816
2818
2819
Geographical
classification
All
All
All
All
All
Reg. I & II
Reg. Ill & IV
Reg. V & VI
Reg. VII
Reg. VIII & IX
All
All
All
All
All
All
No. of
replies
37
12
16
3
6
9
12
7
4
5
2
0
16
0
14
5
Mean
responses
596
668
588
692
426
487
384
846
1,540
196
4
0
885
0
545
53
203
-------
Off-Quality Product. Twenty-four responses concerning quantities of
off-quality product process waste were received. These responses averaged
962 tons per year, and ranged from one ton per year to 9,060 tons per year.
There was an orderly progression of quantity with plant size: 25 tons per
year for small plants, 907 for medium plants, 1,410 for large plants, and
2,150 tons per year for extra large plants. This relationship may be expected,
since off-quality product quantities are directly related to production quantities.
Eighteen of the 24 responses were in SIC's 2818 and 2819, and they averaged
970 tons per year. Eight of the responses came from regions I and II, averaging
1,460 tons per year, while thirteen came from regions III and IV and regions
V and VI, averaging 169 tons per year.
Other Process Wastes. Thirty responses were received as to quantities
of "other" process wastes. These responses averaged 988 tons per year, and
ranged from 1 to 15,000 tons per year. Because of the many different types of
waste which could be lumped under this category, the responses in the various
plant size, SIC, and geographical classifications were quite varied and therefore
not amenable to analysis or discussion.
Plant Visits. Table 32 presents a comparison of process waste quantities
determined by the mai] survey and the plant visit survey. The table shows
excellent agreement in some cases and wide variation in others. In the case of
the plant visits, questioning of the validity of numerical response is ruled
out because of the opportunity to check the values "on the spot" with the
respondent. Thus the wide difference in the filter residue response is considered
to be real. All other mail responses are considered to be reasonably well
supported by the plant visit results. The off-quality product difference is
readily accounted for by the greater percentage (83 percent) of medium, large,
and extra large plants surveyed in the plant visits.
-------
TABLE 32
COMPARISON OF PROCESS WASTE QUANTITIES AS DETERMINED
BY THE MAIL AND PLANT VISIT SURVEYS
Process waste
Sludge
Filter residues
Tar
Flyash
Off-quality product
Other process waste
Mall
No. of
replies
131
72
37
19
24
30
survey
Mean waste
quantity
(TPY/reply)
25,000
(13,000)*
43,000
(1,200)*
600
22,000
960
990
Plant visit survey
No. of
replies
27
8
15
4
7
2
Mean waste
quantity
(TPY/reply)
34,000
149,000
1,750
20,000
3,300
600
Overall mean per
process waste type
Mean process waste
generation per plant
313
22,000
213** 33,000***
63
26**
36,000
86,000***
*The quantities given in parentheses are the mean values obtained when the
highest single response was deleted.
**Number of plants reporting process waste.
***Tona per year per plant.
205
-------
Question 5(a)-Storage and Disposal of Process Wastes. A number of
questions were posed relating to waste storage methods and duration, transportation
methods, disposal sites, and disposal methods for process wastes. These responses
will be summarized by a series of tables giving the overall results. Significant
departures from the overall means will be pointed out.
Waste Storage. Table 33 summarizes the overall process waste response
regarding waste storage.
The storage period for sludge wastes varied from 211 days for small plants
to 32 days for extra large plants. SIC 2813 and 2819 plants had the longest
storage periods for sludge waste, 319 and 170 days, respectively. Storage
periods for sludge were shorter for regions I and II and regions V and VI
(100 and 52 days, respectively).
For filter residue process waste, the storage period varied from 93 days
for small plants to one day for the four large plants responding. In SIC 2818,
21 plants averaged 8.5 days, while in SIC 2819, 27 plants averaged 125 days.
In regions VIII and IX, seven plants averaged 151 days, but in the rest of the
geographical classifications, the storage periods were reasonably close to the
mean value of 68 days.
The storage period for tar wastes varied from 52 days for medium plants
to four days for the two large plants responding. In regions I and II, seven
plants averaged 14 days, while in regions V and VI, six plants averaged 8 days.
Twenty-eight of the 32 responses were in SIC's 2815 and 2818, and these were
quite close to the mean storage period of 38 days.
For flyash wastes, eight large and extra large plants averaged six
days for storage, while four medium plants averaged 106 days.
Off-quality product waste storage periods varied from 51 days for small
plants to 5 days for the three large plants reporting. For responses of any
-------
TABLE 33
SUMMARY OF MAIL SURVEY RESPONSES REGARDING PROCESS WASTE STORAGE
Process waste
Sludge
Filter residue
Tar
Flyash
Off -quality
product
Other process
waste
All process
wastes
Mean storage
period (dfys)
115 days
(83 responses)
68 days
(52)
38 days
(33)
39 days
(12)
32 days
(22)
13 days
(15)
73 days
(217)
Storage method*
Container
45%
(56)
62%
(40)
85%
(28)
43%
(6)
88%
(22)
70%
(14)
59%
(166)
Casual
9%
(ID
15%
(10)
12%
(4)
15%
(2)
8%
(2)
10%
(2)
11%
(31)
Ponds
23%
(28)
8%
(5)
0
(0)
21%
(3)
4%
(1)
5%
(1)
14%
(38)
»
No storage
22%
(27)
15%
(10)
3%
(1)
21%
(3)
0
0
15%
(3)
16%
(44)
Other
1%
(1)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(1)
^Percentages shown relate to the proportion of those plants responding who utilize
the indicated storage method for the various process waste.
207
-------
TABLE 34
SUMMARY OF MAIL SURVEY RESPONSES REGARDING PROCESS WASTE TRANSPORT
Transport method*
Process waste
Sludge
Filter residue
Tar
Flyash
Off-quality
product
Other process
waste
All process
waste
Truck
61%
(77 replies)
78%
(55)
97%
(38)
65%
(11)
96%
(24)
97%
(28)
76%
(233)
Pipeline
35%
(44)
22%
(16)
3%
(1)
29%
(5)
4%
(1)
3%
(1)
22%
(68)
Barge
3%
(4)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
1%
(4)
Rail
1%
(2)
0
(0)
0
(0)
6%
(1)
0
(0)
0
(0)
1%
(3)
Captive
80%
(66 replies)
65%
(24)
70%
(14)
82%
(9)
82%
(9)
94%
(15)
77%
(137)
Transport agency*
Private contract
18%
(15)
32%
(12)
30%
(6)
18%
(2)
18%
(2)
6%
(1)
21%
(38)
Government
2%
(2)
3%
(1)
0
(0)
0
(0)
0
(0)
0
(0)
2%
(3)
*Percentages shown relate to the proportion of those plants responding who utilize the indicated transport
method or agency for the various process waste types (components).
-------
significant numbers, SIC and geographical classifications did not exhibit marked
deviation from the means.
For "Other" process wastes, five small and five medium plants reported
average storage periods of 31 and 5 days, respectively. Fourteen of the
fifteen responses were In SIC 2818 and 2819.
Storage methods did not deviate more than 10 percent from the mean
percentages given on Table 33 except for a few instances, when plant size, SIC
and geographic classifications, or combinations thereof, were considered. In
many of these cases, the number of responses comprising the mean value was
quite small and not amenable to analysis or discussion. A few examples include:
Filter residue waste; SIC 2819; Nineteen plants (83 percent)
indicated container storage, compared to an overall mean of
62 percent. Eleven plants (85 percent) in regions III and
IV indicated container storage compared to the overall mean
of 62 percent.
Tar Waste; SIC 2815; Fourteen responding plants (100 percent)
indicated container storage, as did ten in regions I and II
(100 percent), compared to an overall average of 85 percent.
Waste Transport. Table 34 summarizes the overall response regarding
process waste transport. Seventy-seven percent of the plants reporting
process waste employed captive transport facilities with very few reporting
government transport. The following are significant deviations from the overall
means for the various transport methods.
Eleven extra large plants reported transport of sludge to a greater
degree by truck than the overall mean response (79 percent vs. 61 percent),
and less by pipeline (21 percent vs. 35 percent). Only two large plants and
209
-------
TABLE 35
SUMMARY OF MAIL SURVEY RESPONSES REGARDING PROCESS WASTE DISPOSAL*
Site
Nature of
offsite
disposal
Disposal
method
Ons ite
Offsite
Captive
Private
contract
Govern-
ment
Land
disposal
Incinera-
tion
Lagoons
Ocean
disposal
Other
Sludge
46%
(63 replies)
54%
(73)
15%
(11)
58%
(41)
27%
(19)
68%
(91)
4%
(5)
15%
(20)
1%
(1)
12%
(17)
Filter
residue
36%
(26)
63%
(45)
11%
(5)
52%
(24)
37%
(17)
76%
(51)
10%
(7)
8%
(5)
0
(0)
6%
(4)
Tar
49%
(19)
51%
(20)
10%
(2)
58%
(11)
32%
(6)
71%
(27)
24%
(9)
0
(0)
0
(0)
5%
(2)
Process
Flyash
50%
(8)
50%
(8)
11%
(1)
78%
(7)
11%
(1)
59%
(10)
0
(0)
23%
(4)
0
(0)
18%
(3)
Waste
Off-quality
product
44%
(11)
56%
(14)
14%
(2)
57%
(8)
29%
(4)
83%
(20)
4%
(1)
0
(0)
0
(0)
13%
(3)
Other process
wastes
45%
(14)
55%
(17)
40%
(6)
20%
(3)
40%
(6)
80%
(24)
7%
(2)
3%
(1)
0
(0)
10%
(3)
All process
wastes
44%
(141)
56%
(177)
15%
(27)
54%
(96)
30%
(53)
72%
(223)
8%
(24)
10%
(30)
0
(1)
10%
(32)
^percentages shown relate to the proportion of those plants responding who utilize the indicated disposal
technique for the various process waste types (components).
-------
two medium plants indicated barge transport of sludges. Truck transport of
sludges predominated in regions I and II and in regions V and VI (77%, 31
responses and 77%, 17 responses, respectively), and was least in region VII
(35%, 7 responses). Pipeline transport predominated (60 percent, 12 responses)
in region VII. All sludge wastes reported in SIC 2815 (16 responses) were
transported by truck.
All sludge transport in extra large plants is accomplished by captive
facilities (nine responses). The same is true for the extra large plants in
SIC 2812 and SIC 2813 (13 responses). In SIC 2815, the transport was split
evenly between captive and private contract facilities (eight responses). In
regions I and II, 59 percent of the transport (13 responses) was captive, while
in regions V and VI and in region VII, transport was captive by 93%, 12 responses
and 93%, 14 responses, respectively.
Nine large and extra large plants reported all transport of filter
residue by truck. Twenty-four SIC 2818 plants reported 96 percent transport of
filter residue by truck. Twelve medium plants (52 percent) reported transport
by governmental facilities, as did five (83 percent) SIC 2812 plants.
Waste Disposal. Table 35 summarizes the overall response regarding
process waste disposal. The following are significant deviations from the
overall means.
Incineration of sludge waste is more prevalent in SIC 2818. Eighteen
(75 percent) of these plants indicated incineration of sludge wastes. Three
(23 percent) extra large plants are included. Most likely, the solids contained
in these sludge wastes are primarily organic materials generated from production
of miscellaneous organic chemicals, and therefore are amenable to Incineration.
Nine of the extra large plants (64 percent) Indicated onsite sludge disposal,
211
-------
as did 17 of regions III and IV extra large plants (77 percent). In regions
I and II, only 12 (29 percent) of the plants indicated onsite disposal.
In regions III and IV, eight plants (40 percent) responded that incineration
was their means for filter residue waste disposal. In SIC 2818, seven (30
percent) indicated incineration for filter residue waste disposal, which again
reflects the organic nature of solids in filter residues from this industry
segment.
In SIC 2815, seven plants (41 percent) indicated incineration for disposal
of tar wastes, as did seven plants (58 percent) in regions III and IV.
Question 5(b)-Cost of Disposal of Process Waste. The respondents were
asked to indicate the total disposal cost for each process waste generated as
well as the components of that cost (i.e. cost for process waste storage,
pretreatment or special handling, transportation, the ultimate disposal method,
and any credit). In some categories, a very sparse response was obtained. In
many cases the respondents did not segregate total cost into the various storage,
transport, etc. components, but did provide the total disposal cost. The
mean values reported for these costs are summarized in Table 36.
The component costs reported in columns 1 through 5 on Table 36 are
independent of the total disposal costs in column 6. Costs in columns 1 through
5 are the mean of the costs for the particular component operations as reported
by those replying to the question, and the costs in column 6 are the mean of
the total disposal costs reported by those replying. Therefore, the mean values
are based on a different quantity and possibly different types of plants and
the component costs (columns 1 through 5) do not add up to total disposal costs
(column 6) on the table. Total disposal costs (column 6) were found to be less
than the sum of the component costs, except for the off-quality product wastes
(credit not included). A possible reason for this is that the individual
-------
to
M
Ul
TABLE 36
SUMMARY OF MAIL SURVEY RESPONSES REGARDING PROCESS WASTE DISPOSAL COSTS*
Process waste
Sludge
Filter residue
Tar
Flyash
Off-quality
product
Other process
waste
All process
waste
1
Cost of
storage
$4.00
(14 replies)
$18.00
(8)
$50.60
(3)
$2.00
(4)
$1.70
(3)
$11.40
(32)
2
Cost of
pretreatment**
$14.70
(22)
$6.70
(4)
$34.20
(4)
$1.00
(2)
$6.00
(3)
$14.48
(35)
3
Cost of
transport**
$31.20
(47)
$22.40
(21)
$16.30
(16)
$1.00
(6)
%5.90
(ID
$7.30
(21)
$19.84
(122)
4
Cost of
disposal**
$13.10
(51)
$118.50
(22)
$20.10
(17)
$2.00
(5)
$7.60
(10)
$6.50
(13)
$32.09
(118)
5
Credit for
salvage***
$379.80
(5)
$420.00
(2)
$.40
(1)
$50.00
(1)
$50.00
(1)
$283.94
(10)
6
Total
disposal cost****
$33.00
(65)
$93.80
(46)
$41.70
(26)
$2.10
(9)
$25.70
(13)
$14.00
(20)
$44.67
(179)
*A11 costs shown are mean values and are in $/ton.
**Columns 1 through 5 report the mean of the reported cost for the particular component operations for
those replying to the question.
***Much fewer tons are salvaged than are stored, pretreated, transported and disposed of.
****Column 6 reports the mean of the reported total disposal cost for those replying to this equestion
and was not derived from the reported component costs.
-------
questionnaire replies of total disposal cost were probably obtained from
readily available cost Information, such as private contractor Invoices, and
did not Include costs for storage, pretreatment, and onslte transport. These
costs are more difficult to obtain, and are not readily available In many
plant records.
Study of Tables 32, 33, 34, and 35 In comparison to Table 36 provided
only limited Insight .as to relationships between cost differences and differences
In waste quantities, storage, transport, and disposal practices.
Filter residue process waste Indicated the highest disposal cost (Table
36). Table 35 shows that 32 percent of this waste Is transported by private
contract, and Table 34 indicates that 63 percent is disposed offsite, of which
52 percent is handled by private contract. These facts could account for the
high disposal cost.
The relatively low cost for storage of sludge wastes may be explained
by the fact that only 45 percent of the replies for sludge waste indicated
container storage whereas 62 percent and 85 percent of the replies indicated
container storage for filter residues and tars respectively.
Off-quality product and other process wastes exhibited lower transport
and disposal costs than did sludges, tars, and filter residues. These wastes,
largely stored in containers, and almost entirely transported by truck, are
probably capable of being packaged more efficiently with resulting economies.
Although the process waste cost distributions differed somewhat in the
various SIC and regional classifications, it is not considered worthwhile to
report these in any detail. In many cases, the storing, handling, or disposal
of a particular type of waste can be unusual enough to result in a high cost
response. This occurrence is felt to unduly bias the mean value in a particular
SIC, plant size, or geographical combination where only a small overall
-------
response was obtained. Therefore, deviations from the overall means do not
have sufficient significance to warrant detailed review.
Question 6-Physteal and Chemical Characteristics of Process Wastes.
The questionnaire asked for chemical and physical characteristics pertinent to
solid waste disposal activities. This question received rather sparse response,
and was analyzed only to the extent that a process waste was classified as toxic
or inert. Table 37 summarizes the results. In general, of the 44 total responses
obtained, less than half (40 percent) of the process wastes were considered
toxic by the respondents.
Question 7-Waste Generation Parameters. The questionnaire asked for
the plant operating parameter which most directly influences waste generation.
Table 38 summarizes the results of the response to this question. The response
was surprisingly good to the extent that various influencing parameters were
identified; however, virtually no quantitative relationships were supplied.
Question 8-Five Year Projection as to Waste Quantities, Disposal Practices
and Costs. Significant responses were received only about projected waste
quantites. These were expressed in a number of ways, including annual percentage
increases, overall (five year) percentage increases, and actual projected
tonnages for 1975. All replies were converted for expression in the latter
form. They are summarized on Table 39, and when compared with 1970 quantities,
it is apparent that substantial increases in most waste categories are anticipated,
particularly in the already large quantity areas. In the comparisons of Table
39, no attempt was made to delete the very high responses.
Detailed comparisons between 1970 and 1975 values for the plant size,
SIC, and geographical classifications were not considered since it was felt
that meaningful relationships could not be established from the limited data.
Plant Visits. The results obtained from the plant visits bear out those
215
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TABLE 37
SUMMARY OF MAIL SURVEY RESPONSES REGARDING PROCESS WASTE CHARACTERISTICS*
Process waste Toxic Inert
Sludge 35% 65%
(6 replies) (11)
Filter residue 20% 80%
(2) (8)
Tar 90% 10%
(9) (1)
Flyash 0 100%
(0) (4)
Off-quality
product
Other process 33% 67%
wastes (1) (2)
All process 40% 60$
wastes (18) (26)
^Percentages shown relate to the proportion of those plants responding who
indicated toxic or inert process waste characteristics.
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TABLE 38
SUMMARY OF MAIL SURVEY RESPONSES REGARDING
PROCESS WASTE GENERATION PARAMETERS*
Waste Generation Parameter
Process waste
Sludge
Filter residue
Tar
Flyash
Off-quality
product
Other process
wastes
All process
wastes
Purity of
raw material
48%
(43 replies)
41%
(19)
12%
(3)
89%
(8)
13%
. (2)
8%
(2)
37%
(77)
Degree of
reaction
11%
(10)
11%
(5)
44%
(ID
0
(0)
13%
(2)
8%
(2)
14%
(30)
Amount of
production
17%
(15)
20%
(9)
4%
(1)
0
(0)
0
(0)
38%
(10)
17%
(35)
General
maintenance
6%
(5)
2%
(1)
4%
(1)
0
(0)
27%
(4)
19%
(5)
8%
(16)
Other
18%
(16)
26%
(12)
36%
(9)
11%
(1)
47%
(7)
27%
(7)
24%
(52)
(Percentages shown relate to the proportion of those plants responding who
indicated waste generation parameters.
217
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TABLE 39
SUMMARY OF MAIL SURVEY RESPONSE REGARDING PROCESS WASTE QUANTITIES IN 1975
Process waste
Sludge
Filter residue
Tar
Flyash
Off-quality
product
Other process
Overall mean per
process waste type
1970 Quantities
(mean value tons
per year)
25,400
(131 replies)
42,900
(72)
596
(37)
21,800
(19)
962
(24)
988
(30)
22,000
(313)
1975 Quantities
(mean value tons
per year)
39,600
(92)
64,200
(50)
782
(27)
19,500
(10)
654
(14)
1,820
(17)
33,900
(210)
Increase or
decrease
%
55%
Increase
50%
Increase
31%
Increase
11%
Decrease
32%
Decrease
85%
Increase
54%
Increase
-------
obtained from the mall survey with remarkable consistency, where the size of
response Is sufficiently large to permit valid comparisons. The storage periods
for the various process wastes, as reported from the plant visits, deviate
somewhat In the direction of shorter storage Intervals. Since the plant visits
were predominantly to the three larger plant size categories, this was expected.
A higher degree of Incineration disposal was reported for tar In the
plant visits than It was for the mall survey (57 percent, 12 responses vs.
24 percent, 9 responses). Five plant visits also Indicated Incineration disposal
for off-quality product, whereas only one mall survey plant reported this
combination. These practices were reflected In greater onslte disposal for
both wastes In the plant visit survey.
The disposal costs for the plant visits were quite different from those
obtained for the mall survey for most process wastes. In most cases, the costs
were significantly lower. For example, the overall transport costs were $5.68
(29 responses) per ton for the plant visits and $19.84 (122 responses) per ton
for the mall survey. The same type of relationship existed for disposal costs
and total disposal costs. This trend Is again thought to be attributable to
the greater average size of the plant visited, compared to the mall survey.
The larger plants generally handled greater waste quantities and achieve lower
per ton costs.
The plant visit survey projected generally lesser Increases of process
wastes for 1975 than did the mall survey.
Municipal Questionnaire
A special questionnaire was sent to municipal and regional officials In
Jurisdictions where the manufacture of Industrial chemicals was known to be a
219
-------
major industry. This questionnaire was designed to supplement the industry
survey by providing insight regarding the view taken by governmental officials
of the disposal of solid waste from the chemical industry. A sample copy of
the questionnaire appears in the Appendix.
A total of 130 copies of this questionnaire were mailed, and 64 replies
were received for a response of 49 percent. The distribution in the geographical
regions approximated the distribution of mailings to the chemical plants in
those regions.
A question-by-question review of the response to this municipal survey
follows.
PART A Municipal Refuse Disposal.
Questions 1 and 2. The municipal officials were asked to identify the
disposal facilities in their areas of jurisdiction. Responses indicated that
12 percent operated dumps, 92 percent sanitary landfills, and 22 percent
incinerators. As can be seen by these figures more than one type of disposal
facility was often reported in a single jurisdiction.
Question 3. This question was inadvertently misstated, so that any
response received was invalid.
Question 4. The respondents were asked if chemical industries used the
reported facilities to dispose of solid wastes. The affirmative responses
totaled 66 percent, while 30 percent replied negatively. Of those replying
yes, 19 percent disposed of these wastes in dumps, 83 percent in landfills, and
2 percent in incinerators. (Here too there were some multiple replies.)
Question 5. The officials were asked if pretreatment of chemical wastes
was necessary prior to disposal. The responses were 16 percent positive, 58
percent negative, and 26 percent did not reply. Of those who replied
positively, the treatment methods mentioned included dilution, neutralization,
and assurance that contaminated containers are rendered totally useless.
-------
Question 6. The respondents were asked if their disposal facilities
have any special design features to accommodate waste from the chemical
industry. Only 6 percent (four replies) answered affirmatively, while 75
percent said no, and 19 percent did not reply. Two cities indicated special
pits and eventual cover for liquid chemical wastes and special cover of solid
chemical wastes in sanitary landfills.
Question 7. This question asked for special problems encountered with
waste from chemical industries. Problems were encountered by 30 percent, 31
percent indicated no problems, and 39 percent did not reply. Special problems
mentioned included odors, fire and explosion hazards, and leaching into
waterways. Fires are handled In one city by smothering If in solid materials,
or by allowing burnout, if in liquids. One respondent indicated a special
waste pit equipped with sprays for fire control. Several provide inspection
prior to permitting chemical waste to be disposed at their facilities, and
some indicated that special instructions are issued to haulers bringing in
such wastes.
PART B Non-Municipal Refuse Disposal.
Question 1. The officials were asked if any problems occurred with
private contract solid waste disposal facilities which handled waste from
chemical industries. Responses were 11 percent yes (seven responses), 48
percent no, and 41 percent no reply. Of the yes responses, some indicated that
problems with odors, fires, and leaching occurred with these operations. In
one case deliverate fires, contrary to regulations, were mentioned, and
another respondent indicated that the private operations in his jurisdiction
did not give proper attention to the hazardous aspects of chemical waste
disposal. Most of the negative or "no reply" respondents did mention a lack
of knowledge of private operations or their problems.
221
-------
Question 2. This question asked if chemical companies have difficulties
disposing of their own chemical waste. Of those replying 9 percent (six
replies) said yes, 33 percent said no, and the balance did not reply. Little
elaboration was received from those who did reply positively. As in Question 1
above, many of the negative or "no reply" responses mentioned a lack of
information on the internal waste disposal operations of chemical companies.
PART C Assessment of Chemical Plant Solid Waste.
Question 1. Officials were asked their opinion of the solid waste
disposal practices of the chemical industries in their area. Although 36
percent did not reply, 28 percent rated them good, 28 percent rated them fair,
and 8 percent rated them poor.
Question 2. The officials were also asked if restrictions on chemical
industry waste disposal are under consideration. Of the replies 17 percent said
yes, and 41 percent said no, with 42 percent not replying. Of those replying
positively, none cited specific restrictions, but some indicated that water
quality and sewer ordinances were presently being applied to regulate chemical
waste disposal.
Question 3. The officials were asked to indicate which of several items
best describe problems observed at chemical industry waste disposal sites. The
replies were as follows: 34 percent indicated odors, 11 percent listed
unsightly waste storage, 25 percent indicated potentially hazardous conditions,
8 percent cited standing water, 13 percent listed spillage from trucks hauling
wastes, 8 percent cited uncontrolled and smoky burning, 13 percent indicated
other problems. Of those mentioning other problems, several listed water
pollution, and one cited "fallout" from incineration.
Additional comments were provided by 45 percent of the officials. Many
of these were contacts suggested for additional information. The respondent
-------
from one large city indicated that there would be private disposal of
objectionable liquid wastes by deep wells in early 1971. Another in the same
area referred to a central multiplant disposal area under construction. Mention
was also made by one respondent of consolidation of municipal landfill areas,
with attendant improvements in control of types of waste disposed.
223
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SECTION EIGHT: DISCUSSION OF FINDINGS, PROPOSED SOLUTIONS AND RECOMMENDATIONS
Magnitude of the Solid Waste Disposal Problem
Solid Waste Management System Characteristics
Solutions to the Solid Waste Management Problems
Recommendations for Further Research and Development
Tables
40 Comparison of solid waste management characteristics by
region 232
41 Advantages of centralized industrial waste disposal
facilities 242
Preceding page blank
225
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SECTION EIGHT: DISCUSSION OF FINDINGS, PROPOSED SOLUTIONS AND RECOMMENDATIONS
Magnitude of the Solid Waste Disposal Problem
The magnitude of the problem of solid waste management in the industrial
chemical industry is exemplified in the diverse types and large quantities
of solid waste that must be handled, the expense of the required management
systems, and the environmental problems encountered in waste treatment.
The characteristics of solid wastes generated by the industrial chemical
industry are probably more varied than in any other industry. This is due to
the many types of process wastes generated from the production of many thousands
of different chemicals.
For those plants responding to the mail survey, the average quantity of
non-process waste reported was 690 tons per year. The breakdown of average
combustible and noncombustible non-process waste quantities was 562 tons per
year and 207 tons per year, respectively.
Considering that a 15 cubic yard dump truck can carry approximately one
ton of loose type //I waste (rubbish) and four tons of noncombustible waste,
a plant handling the average quantities of both combustibles and noncombustibles
would require 12 truck loads a week hauled to disposal, or two per day in a
six day week. The average storage period reported on the questionnaire was
10 days for combustible waste and 22 days for noncombustible waste. This
storage period, applied to the average waste quantities generated, indicates
a need by this average plant for 137 cubic yards of storage for non-process
waste, or about 70 two-cubic yard containers. It is thus apparent that the
average industrial chemical plant has a significant solid waste management
problem with non-process waste alone.
Industrial chemical plant process waste generation was reported to be
Preceding page blank
227
-------
far greater than non-process waste generation. For plants indicating process
waste generation the mean waste quantity for a single process waste type was
22,000 tons per year (Table 32). Ass timing that this single process waste type
is a sludge or filter residue at 75 pounds per cubic foot, and applying the
average reported storage period of 33 days for all process wastes (Table 33),
the mean storage capacity required would be 53,000 cubic feet. Considering
only the mean reported sludge waste generation of 25,000 tons per year which
has a far longer storage period of 115 days, the required storage capacity would
be 214,000 cubic feet. For average filter residue generation (43,000 tons per
year) with a storage period of 68 days, 213,000 cubic feet of storage capacity
would be required.
The major disposal method for both sludge and filter residue wastes is
landfill (68 percent of sludge and 76 percent of filter residue responses).
At a maximum landfill depth of 10 feet and excluding waste shrinkage or cover
material, land disposal area required for average sludge and filter residue
generation would be approximately 2 acres and 3.3 acres per year, respectively.
The industry's need for large storage and disposal facilities such as ponds
and lagoons is apparent from these figures.
The average quantity of tar waste generated by those plants reporting
tar waste generation was 596 tons per year. A tar burner of about 400 pounds
per hour capacity, operated 6 days per week, 12 hours per day, would be needed
for this quantity of waste. This is a small incinerator, but depending upon
the combustion characteristics of the tar, it may require complicated air
pollution control equipment.
Thus, the plant disposal system for process wastes must be large enough
to handle the substantial waste volumes and capable of handling different
types of wastes.
-------
Plants responding to the process waste questions of the mail survey
averaged 1.5 process waste types per plant, with all but small plants averaging
over two. The average industrial chemical plant responding to the mail
questionnaire generated approximately 33,000 tons per year of process waste of
more than one major waste type. Applying the generally accepted generation
rate of 5 pounds per person per day (0.8 tons per year) of municipal refuse
in the United States, our average plant generates the waste tonnage equivalent
of a city of 37,500 people. This result is based on the average of 690 tons
per year of non-process and 33,000 tons per year of process wastes, for a total
of 33,690 tons per year for the average plant.
While the survey results cannot be projected on a total national basis,
it is apparent that solid waste from the industrial chemical industry can be
as serious a problem in terms of quantities as that generated by Individuals.
The cost to the industry of solid waste management was found to be
substantial and of great concern to plant management. The average cost for
non-process waste disposal for plants responding to the mail survey, including
collection and transportation, was $32.80 per ton for combustible and $23.80
per ton for noncombustible solid waste. The corresponding weighted* average
cost was $14.98 per ton for combustibles and $12.35 per ton for noncombustibles,
while the overall weighted average cost was $14.11 per ton of non-process
waste. This result reflects the decrease of disposal costs as solid waste
quantities increase. These figures may be compared to typical costs of $20-$30
per ton for disposal and collection of municipal solid waste. The weighted
average cost and the annual average generation of non-process waste results
in a total yearly cost of approximately $9,700 for non-process waste management.
The cost of solid waste management from process waste fluctuates widely
*The average obtained by summing the product of per ton cost and tonnage
for each reply, divided by total tonnage reported.
229
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from plant to plant, due mainly to the variability of waste types, the extreme
range of annual process waste quantities (from one ton to over a million),
and the wide differences in disposal methods utilized (from complex incinerators
to simply dumping on the ground). This wide variability is illustrated by
comparison of the mean per ton cost with the weighted average for all process
wastes and all plants. The overall mean shown on Table 36 was $44.67 per ton,
computed as the average of each responding plant's dollar per ton cost. The
weighted mean was $4.10 per ton from the mail survey and $2.73 per ton from
the plant visits. The weighted mean cost from the mail survey can be applied
to the reported average annual plant process waste generation rate of 33,000
tons per year, to provide an average estimate of $135,000 per year for solid
waste management of process wastes. When this is added to the average cost
of non-process waste management, a total annual estimate of approximately
$145,000 is obtained for management of solid waste by the typical industrial
chemical plant responding to the mail questionnaire.
The relatively low weighted figure for process waste disposal costs is
significantly influenced by the low cost of disposal for extremely large
quantities of sludge and filter residue which are disposed of in lagoons or
diked areas. This type of disposal is generally coupled with pipeline transport
and is usually inexpensive.
Industrial chemical plants reported that they expect future solid waste
generation to increase significantly. Sludges and filter residues, the two
predominant process wastes, were expected to Increase 50 percent or more in
the five years between 1970 and 1975, as shown in Table 39. The decrease in
flyash generation is probably due to the conversion of many plants from the
burning of coal to low ash content fuels such as oil and gas. Off-quality
product waste also showed a projected decrease which may indicate the beginning
-------
of a trend within the industry to reduce this type of waste through increased
production efficiency. All responses for increased solid waste generation
'Were projected for existing solid waste streams. Plants did not report future
generation from expected new sources brought about by new processes or changes
in plant operations. These wastes would be projected increases to the existing
quantities. Although the survey indicates a rather definite trend for increasing
quantities of process waste, few respondents projected waste management costs
five years from now, except to the extent that they would be influenced by
Increasing quantities.
Environmental problems are potentially associated with disposal and industrial
chemical plant solid waste in all environmental mediums: air, water, and
land. The degree to which a waste can contribute to environmental pollution
is highly variable depending on waste characteristics and disposal methods
employed, yet all wastes can be a potential problem. Significant in this respect
is that almost as many process wastes were considered by responding plants to
be toxic as were considered to be inert (40 percent versus 60 percent).
Air pollution may occur when odors or noxious gases are emitted from
decomposition or incineration of the waste, requiring that special disposal
procedures be followed. Inert wastes may also contribute to air pollution
if they cause dusting when exposed to the elements. There is a current trend
toward stricter air pollution regulations which may prohibit or require modification
of certain plant solid waste disposal practices. For example, open burning
has been prohibited in many areas, and current emphasis appears to be on more
efficient air pollution control equipment for incinerators. More rigid control
of other air pollution sources at some plants may also result in additional
solid wastes (such as increased amounts of flyash withdrawn from boiler flue
gases).
Water pollution is associated with solid waste disposal under the following
231
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conditions: (1) When noxious liquid chemicals contained within the solid
waste leach into water supplies. This may occur in wet sludges and filter residues
or tars which are dumped on the ground or buried; (2) When soluble portions
of the solid waste are dissolved in ground or surface water; (3) When the
liquid portion of a slurry is passed into receiving waters; and (4) When
scrubbing liquids used to remove noxious gases and particulates from stacks of
solid waste Incinerators or powerhouse boilers are sent to receiving waters.
Regulations dealing with disposal of waste liquids are becoming Increasingly
more restrictive. Regulations dealing with groundwater contamination are similar
to those of surface waters, but to date have not been enforced as vigorously.
It is difficult to trace the source of groundwater contamination, and the
effects of the contamination may not be apparent for some time after the disposal
of the solid waste. Greater emphasis on eliminating sources of groundwater
pollution can be expected, probably resulting in increased restrictions on
the practices of burying, ponding, or otherwise exposing wastes to the land.
The concentration of suspended solids in waste streams is limited by
water pollution regulations. Any further reduction of permissible solids
concentration will result in additional solids removal and subsequent disposal
needs. In addition, as treatment requirements increase, more plants will
install biological treatment systems which will result in additional sludge
wastes.
Land pollution may occur If the solid waste contaminates the soil, rendering
it incapable of supporting plant growth or wildlife, or if it causes hazards
which preclude development of industry or dwellings. Rendering a relatively
small piece of land sterile was unimportant in the past when there was so much
land available, but as population grows, there will be greater emphasis on
preserving those natural areas which previously might have been prime sites
232
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for disposal operations. These Include marshes, lowlands, river banks, etc.
As land costs rise, the utilization of land at its highest level will be
Increasingly important to both industry and the public, and disposal operations
which remove land areas from consideration for future development will be
considered wasteful and expensive. At the present time, there is very little
legislation regarding land pollution, but it is expected that restriction of
land disposal to protect the soil and to preserve land areas will eventually
be instituted, and this will add still another factor to be considered in the
planning of disposal systems for chemical solid wastes, and indeed for all
solid wastes.
One responding plant reported a problem which serves as an excellent
example of land use difficulties brought about by inadequate solid waste
management practices. During the early days of the plant operation, chemical
wastes were buried in barrels, but accurate records of the waste characteristics
and disposal sites were not kept. Now as the plant expands and these areas
are built on, extreme precautions must be taken to avoid accidents during
excavation, since the nature of the waste is unknown and it may be hazardous.
Waste disposal methods and practices are aggravated not only by increasing
environmental and ecological restrictions, but also by the changing nature of
chemical wastes themselves. The trend in chemical production today is toward
more complex and highly reactive materials, and the waste from these new processes
will be equally complex and will require more sophisticated disposal methods.
The individual plant Is therefore challenged to examine its own wastes from
each process and to develop the best solid waste management plan. In contrast,
other industries such as steel, paper, brewing, and meat processing ordinarily
have waste problems which are common within the industry, and if a satisfactory
solution is developed by one plant, the disposal method often is adopted by
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TABLE 40
COMPARISON OF SOLID WASTE MANAGEMENT CHARACTERISTICS BY REGION
Characteristic
Size of plant (based
on employment)
Region
Nature of manufacture
General
Size of plant site
increasing plant site
size with increasing
size of plant
regions I & II and VIII
& IX have plant sites
smaller than the mean
SIC 2812 and 2813 plants
occupy smaller than
average sites
Nature of area
surrounding plant
regions I & II have higher
percent of plants in urban
areas
Use of public site
small and extra large
plants report greater
use
regions I & II and VIII &
IX report greater use, and
V & VI and VII lesser use
SIC 2812 plants use them
most, and SIC 2813 plants
use them least
Non-process
waste
Disposal cost
N>
U
•Cfc
decreasing cost with
increasing plant size
except for extra large
plants
regions VIII & IX and III
& IV have higher costs
Disposal method
large and extra large
plants have higher than
average use of in-
cinerators
regions VIII & IX have
higher use of landfill
Waste quantity
increasing quantities
with increasing plant
size
regions I & II have higher
generation, and regions
VIII & IX have lower
generation than the mean
SIC 2812 and 2813 generate
lower than average quan-
tities
Process
waste
Storage period
decreasing storage
period with increas-
ing plant size
regions VII and VIII & IX
utilize larger than average
storage period, and regions
V & VI the shortest period
SIC 2819 exhibits longer
than average storage perio
Storage type
progressively greater
use of containers
with increasing plant
size
regions VII and VIII & IX
have the lowest use of con-
tainers and highest per-
centage of no storage
(pipelines)
SIC 2815 has a greater use
of containers and lower th
average use of other stor-
age methods
Transport method
small and medium plants
exhibit the greatest
use of pipeline trans-
port
regions VII and VIII & IX
possess higher than average
use of pipelines
SIC 2815 has the highest
use of truck and lowest
use of pipeline, and SIC
2813 has the lowest use of
truck and highest use of
pipeline
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TABLE 40 (cont.)
Characteristic
Size of plant (based
on employment)
Region
Nature of manufacture
Process
waste
(cont.)
Disposal agency
Disposal cost
Disposal method
Waste quantity
extra large plants
exhibit lowest govern-
use, large plants use
private contract most,
medium plants exhibit
highest government use
regions V & VI lowest use of
captive and highest use of
private contract
SIC 2812 possesses high
use of government disposal
sites
medium plants exhibit
the highest cost and
large plants lowest
cost
regions I & II and III & IV
report the highest costs
SIC 2818 reports by far
the highest cost
extra large plants ex-
hibit greatest use of
incineration and large
plants the greatest
use of lagoons
regions III & IV report
lowest use of land disposal
and highest use of the
incineration
SIC 2818 and 2815 report
greatest use of incinera-
tion and lowest use of
lagoons
medium plants report
the highest quantity
and small plants the
lowest quantity
region VII report the highest
generation and regions I & II
the lowest generation
SIC 2819 reports the
highest generation and
SIC 2813 the lowest
generation
-------
the entire industry.
In general, the industrial chemical industry is well-equipped to solve
its solid waste disposal problems. Chemical markets remain relatively stable
over long periods, thereby providing a solid economic background. Investments
in pollution control can be expected to be repaid in the lifetime of most
chemical processes. As in other industries, the most economical point for
formulation of waste management policies is ast the process design stage.
Since pollution control is eventually reflected in higher prices, it is only
good competitive business to minimize such increases by controlling pollution
at this stage. The chemical industry has shown a willingness to take this
position in air and water pollution control, and as indicated by this survey,
is beginning to turn similar attention to solid waste disposal.
x
Solid Waste Management System Characteristics
The characteristics of a solid waste management system may vary with the
size of the plant, the location of the plant, and its predominant manufacturing
activity, as shown in Table 40. Two centers of industrial chemical manufacture
in terms of number of plants and value added by manufacture are the states of
New Jersey (region I) and Texas (region VII) (see Section Two). The chemical
plants in these states handle higher average quantities of non-process solid
wastes than plants located in the other states. The survey also showed that
non-process waste generation is generally a function of plant size, i.e., the
larger the plant, the more waste generated. Thus, the rate at which industrial
chemical non-process solid waste is generated in an area appears to be related
to industry concentration in the area.
Although plants in region VII responding to the mail survey also indicated
the highest quantities of each process waste type, the generation of process
235
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wastes Is not necessasrlly related to industry concentration in a geographic
area. Regions I and II, which contain the greatest number of plants, reported
the second highest average sludge waste quantities, while plants in regions
VIII and IX reported the second highest average filter residue waste quantities.
Plants in regions V and VI reported the second highest quantities of tars.
Process waste generation is also not related to plant size. For example,
medium-size plants reported the highest overall process waste quantity, and the
highest sludge and filter residue waste quantities. The quantity of process
waste generated in a geographic area is probably more related to the types
of industrial chemicals produced and the processes used by the individual
plants, than it is to industry concentration.
The availability of adequate land area on the plant site was found to
be a major factor in whether a plant operates onsite disposal facilities, or
must use its own offsite facilities, those of private contractors, or those
of the municipality in which it is located. If potential air, land, or water
pollution from onsite disposal operations is discounted, solid wastes from
industrial chemical operations have their greatest impact on the community
when public facilities are used. The mail questionnaire results indicated that
32 percent of the responding chemical plants are located in urban areas.
These plant sites would be expected to be smaller due to the high land costs
and general lack of undeveloped land, and they can be expected to make greater
use of public solid waste facilities. Forty-one percent replied that their
sites were located in rural areas where more land is available, and these
chemical plants could be expected to use public disposal sites to a lesser
degree. The average plant site size reported by the survey was 199 acres, of
which only 44 percent was devoted to production facilities. These figures
are strongly influenced by the large percentage of responses from plants
-------
located in rural areas.
In regions VIII and IX and I and II, much smaller plant sites were reported,
with greater percentages devoted to production facilities. These regions
contain some of the most densely populated urban areas in the country, and a
high percentage of plants did indicate their location to be in urban areas
(44 percent for regions I and II and 33 percent for regions VIII and IX).
These regions also reported the highest percentage of plants using public solid
waste disposal sites, 55 percent and 56 percent respectively, whereas the
overall average of plants using public solid waste disposal sites was 42 percent.
Most of the plants reporting use of public facilities used them for
non-process waste. Of the two-thirds of non-process waste disposed offsite,
52 percent was disposed at public facilities, whereas of the 61 percent of
process waste disposed offsite, 30 percent was disposed of at public facilities.
A large portion of the process waste disposed at public facilities was flyash
and "other process waste", relatively inert constituents.
Variations in management systems for non-process and process waste
characteristics are also shown on Table 40. Regions VIII and IX and III and
IV were found to have the highest unit disposal costs for non-process waste,
and costs increased with plant size (except for extra large plants which had
lower costs than large plants). Both large plants and extra large plants
exhibit a higher than average use of incineration for non-process waste, and
extra large plants apparently are able to reduce their unit disposal cost by
employing large scale disposal equipment. Plants in SIC 2812 and 2813 reported
a lower overall average non-process waste quantity than the other SIC categories,
probably due to the large number of small plants comprising the categories.
For process wastes, extra large plants were found to make the greatest
use of containerized storage, have the shortest storage period, the greatest
237
-------
use of Incineration, and used government disposal facilities least. Medium
size plants, on the other hand, reported the greatest use of government facilities,
the highest unit disposal cost, and the largest mean process waste quantity
of other size plants. These results point out that plant size categorization
based on numbers of employees is not indicative of process waste generation
or the impact in terms of solid waste that a plant will have on the surrounding
community.
Regions III and IV reported the lowest use of land disposal and highest
use of incineration, as well as a higher than average unit disposal cost for
process waste. Regions I and II also reported higher than average unit disposal
costs, but exhibited the lowest mean generation of process waste. Regions
VII, VIII and IX reported the least use of containers and the greatest use of
pipeline transport. The process waste generated in these regions was held
in storage for longer than the average period. Regions V and VI reported the
lowest use of captive diposal sites and the highest use of private contractors,
as well as a shorter than average storage period.
The variations in characteristics of management techniques among SIC
categories reflect the nature of the process waste generated. Plants in SIC
2819 produce inorganic chemicals, and the solid wastes generated are generally
also inorganic materials. A few processes within this category generate
unusually high quantities of solid waste, and as a result this group exhibited
the highest average generation of process waste. Inorganic wastes are most
amenable to long storage periods and disposal in lagoons, and are quite
difficult to Incinerate.
Solid wastes from organic chemical production, SIC 2818 and 2815, are
generally organic material. Organic wastes will tend to decompose if stored
too long, and are amenable to incineration. Survey results showed that SIC
-------
2815 wastes exhibited the greatest use of containerized storage and truck
transport, and along with SIC 2818, a greater than average use of incineration.
The highest unit cost for disposal of process waste was exhibited by SIC 2818.
The lowest generation of process waste was exhibited by SIC 2813, industrial gases,
the majority of which was waste lime from production of acetylene, normally
transported to disposal by pipeline.
The greatest impact on public disoposal facilities of solid wastes from
Industrial chemical plants appears to be due to chemically contaminated materials
that are mixed with non-process waste and the small quantities of process waste
disposed of at these facilities. Sixty-six percent of the officials responding
to the municipal questionnaire indicated that chemical industries used municipal
disposal facilities, at least somewhat. Of these, 30 percent indicated that
they encountered problems, such as odors, fire and explosion hazards, and
leaching. Sixteen percent also Indicated that pretreatment of this waste was
necessasry, including dilution, neutralization, and decontamination of containers.
When asked to describe the problems observed at disposal sites treating
industrial chemical plant wastes, the officials indicated that odors and
potentially hazardous conditions were the predominant problems. In rating these
disposal sites, 28 percent of the officials rated them "good" and 8 percent
rated them "poor". Their rating of private contract disposal sites was somewhast
similar, with 11 percent Indicating that problems did occur at these facilities
and 48 percent indicating no problems.
Solutions to the Solid Waste Management Problems
The most direct method of controlling the quantity of solid waste produced
by industrial chemical plants is the reduction of solid waste generation at
239
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the source; I.e., the basic process operations. The ideal point for application
of this approach is during the process design stage. When a waste is expected
to be produced, the process designer, who knows best the nature of the solid
waste, should be responsible for specifying the disposal system.
Many Individuals within the industry involved in solid waste disposal
advocate this approach, and argue that the time is rapidly approaching when
waste generation will become one of the most important factors in determining
the efficiency and worth of a process. Under these circumstances, there would
be far greater concern over the quantity and types of waste generated than
today when, for most chemical processes, the total quantity of waste material
emitted to air, water, and land is not well-known.
Once a solid waste is generated, there are two alternatives to its
disposition-disposal or salvage. The great majority of waste inventoried in
this study was discarded. Solutions to the problems of the disposal alternative
involve development of novel and improved ultimate disposal methods and more
efficient management systems.
One of the most immediate, yet usually simple improvements that can be
made in plant storage, collection, and transportation systems for solid wastes
is the elimination of obvious nuisances such as odors, spillage, and unsightliness,
A major objection to chemical plant disposal operations cited by municipal
facilities was the spillage of solid wastes. An example of a straightforward
correction of thi's type of problem was given by a company which hauled flyash
from their boilers to a landfill disposal area. They did so in trucks equipped
with metal covers which were clamped over the loads. This eliminated any
possible blowing or spillage of the flyash and provided a neater appearance
to the operation.
-------
New disposal methods must emphasize abatement of environmental pollution,
reduction of the waste to the smallest possible volume, and recovery of valuable
constituents within the waste. General examples of effective disposal operations
were observed during the plant visits conducted for the survey. An excellent
tar burner system was observed at one large plant, which included storage tanks
for tars of different characteristics to allow for blending to provide a proper
feed to the burner. Temperatures in this unit are maintained in the range of
2800-3000 F, and combustion gases are quenched in a spray chamber, followed
by a high-pressure drop venturi scrubber and a cooler mist-eliminator. All
waste water from the burner is piped to the plant waste water treatment system,
and the stack gases are periodically sampled to assure that air pollution
regulations are not violated.
Another tar burner was observed which was equipped with a waste heat
boiler. Although maintenance costs for this incinerator were high due to the
high furnace temperatures, a significant reduction in operating costs was
achieved by virtue of steam generation. The tar burner operating cost was
about $10 per ton of tar burned, while the waste heat boiler produced about
$7.50 per ton of tar in steam credits. Gas streams from other parts of the
plant were also piped to the burner for odor control.
In some of the more progressive plants, a solid waste sample is first
sent to the laboratory where its combustion products and characteristics are
determined. In this manner, potential air pollution problems or damage to the
incinerator can be assessed before full scale problems arise.
An example of an effective landfill disposal operation, which is used
for process wastes only and does not accept liquids, or oils in either bulk or
barrel form, was also observed. A crane is operated at the site for mixing
soil with all solid wastes to assist decomposition. A bulldozer is also used
to move waste materials and to provide cover and compaction. The landfill
241
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was sealed prior to the start of operations and a dike of hard packed clay
was constructed to keep liquids from leaching out of the fill. A drain is
provided within the dike to collect any liquids accumulating within the landfill,
so that they can be piped to the plant waste water treatment system. All
surface water is drained away from and around the landfill to assure that there
is no leaching into groundwater, and test borings have been drilled around the
site to monitor the groundwater quality. As in this case, proper monitoring
of possible environmental effects of disposal methods is essential to close
the loop on an effective system. Not enough is know today about the effects
of disposing of chemical process wastes to predict accurately all of the
potential environmental effects. Through monitoring, adverse effects can be
discovered early and remedial action can be promptly taken.
Salvage of solid waste, including recyling, recovery, and utilization
is preferable to disposal. A detailed discussion of solid waste recycling
recovery and utilization for the industrial chemical industry has been presented
in Section Five. In most cases, salvage possibilities and procedures must be
developed for each individual solid waste due to the variable characteristics
of process wastes of the industry. Combustion with heat recovery, however,
can be applied to many solid wastes. This process can be accomplished either
in Incinerators such as the tar burners previously mentioned or in the main
plant boilers as discussed in Section Five.
The trend toward incineration of process wastes should be accompanied by
a more frequent use of heat recovery systems. Some environmentalists contend
that destruction of potentially valuable resources by Incineration is poorly
compensated by the heat energy derived therefrom. Yet, an accepted environmental
policy allows the conversion of heat and power generating installations from
the burning of coal and oil to burning natural gas, which is one of the most
-------
valuable sources of raw chemicals. In view of this, the production of heat
energy from waste chemicals which would otherwise be discarded appears justifiable.
Other salvage possibilities can be determined only by thorough analysis
of the particular waste to assess its potential. Some examples of existing
solid waste salvage operations in the chemical industry are given in Section
Five. The U.S. Bureau of Mines conducts research programs aimed at developing
technically feasible and economical methods for treating solid wastes and
secondary raw materials to recover and recycle valuable metals and minerals.
One such project seeks to produce elemental sulfur from gypsum wastes such as
those generated by phosphoric acid production. The U.S. Environmental Protection
Agency too conducts extensive research in this area.
As disposal requirements become more extensive, many plants have begun
to look to outside companies for help, since they believe that extensive solid
waste disposal systems are not always compatible with industrial chemical
manufacture. These systems are generally a nonprofit function within the
chemical plant which many believe could best be handled at a profit by companies
specializing in this field.
In the past, many private contractors operated disposal facilities, which
were inadequate for chemical process wastes. Chemical plants have recently
become concerned with the disposal methods used by these contractors, since
the courts have found that damage caused by improper disposal can be partly
attributable to the originator of the wastes.
One situation was observed during the plant visit portion of the survey
where a number of companies in a particular area joined together and prevailed
upon a local contractor to operate a disposal site for certain process wastes.
The plants helped detail the correct disposal procedures, but the facility was
owned and operated by the contractor. Disposal was by ponds cut into dense
243
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clay, and the contractor had little trouble keeping the site neat and clean
with his substantial array of available earth moving equipment. Monitoring
of nearby streams indicated no detectable leaching.
Unfortunately, there exist very few companies today who are equipped to
handle a variety of industrial process wastes. Some chemical scrap companies
do exist, but they are quite selective in the waste chemicals they handle.
Most industrial representatives contacted during this study were very
receptive to the concept of effective contract disposal. If the few companies
now entering this field can succeed, undoubtedly they will be joined by many
others. In the future, this approach may then become a major solution to the
solid waste management problems of the industrial chemical industry.
A private disposal company is currently being formed in one section of
the country to handle industrial wastes, primarily from the refining, petrochemical,
and chemical industries. This company states that while an "in-plant" disposal
facility gives the plant complete control of disposal and allows design of
facilities for a specific mixture of wastes, it is far more expensive and
the disadvantages are many, when compared to centralized waste treatment.
This company lists the advantages of central industrial waste disposal facilities
as shown in Table 41.
Recommendations for Further Research and Development
The need for further research and development (R & D) applied to the
management of chemical process wastes was highlighted by a number of problem
areas uncovered by this study. These problem areas have just been discussed.
The R & D efforts should be concentrated in two areas: (1) the determination
of the environmental effects of current solid waste disposal practices of the
-------
TABLE 41
ADVANTAGES OF CENTRALIZED INDUSTRIAL WASTE DISPOSAL FACILITIES*
1. Economy of scale
2. Lower total cost
3. Zero capital investment by operating companies
4. Facility is not occupying operating companies' property
5. No reports, sampling, Inspections
6. No meteorological forecasting
7. Hazard- and nuisance-free
8. Wastes can be blended beneficially
9. Technical control
10. Full-time specialists
11. Continuous operation
12. Assurance of future means of disposal at lower cost regardless
of changes in law
13. Expansion and additions at low unit cost
14. Management free
15. Favorable community image
16. No project or startup problems
*From Reference #74.
245
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chemical industry; and (2) the development of improved waste management systems
and procedures, including investigations of techniques to render chemical solid
wastes innocuous.
From the industry's standpoint, the second area would be most valuable,
and to some extent its beginnings are already available from within the industry.
During the study, a number of exceptionally well-designed and controlled disposal
operations were encountered, where the potential for environmental pollution
was at a minimum. In contrast, there were also some extremely poor facilities
ft
with all potentials for pollution maximized. This current industry experience,
both good and bad, could be translated into guidelines for the appropriate
disposal of chemical process wastes.
These guidelines would detail the best procedures for disposal of sludges,
filter residues, tars, off-quality product, etc., by means of the common disposal
methods: landfill, incineration, ponding, lagooning, and ocean disposal.
In most cases encountered in the study where process wastes were inadequately
disposed of, the greatest contributing factors were a lack of knowledge of
correct facility design and disposal procedures, and a lack of understanding
of the necessity for these requirements. Guidelines for design and operation
would provide a meaningful start for the alleviation of these current situations
and to encourage planning and development of future improvements.
In addition to the proposed guidelines, other areas requiring research
attention are:
(1) The environmental effects of land disposal of chemical
process wastes. This area should be subjected to careful
study, including the mechanisms of process waste decomposition
in the soil and the effects on soil types, including the
biodegradability of the waste.
-------
(2) The development of techniques for recyling, recovery,
and utilization of chemical process solid wastes. This area
should be subjected to studies which concentrate on analysis
of new processes and the economics of waste salvage, including
the possibilities of economic incentives.
(3) The development of new solid waste disposal techniques
which accent reduced pollution and economic operation. This
area should be subjected to studies which incorporate the
total esystems aspects of the disposal problem. The Integration
of the disposal method into the total plant operation should be
emphasized, as should the integration of this method into the
chemical process at the time of process design.
(4) The effect on solid waste generation of more stringent
air and water pollution regulations. The extent to which
greater quantities of solid wastes are produced by virtue of
more effective controls in removing solids from chemical
plant gaseous and liquid discharges should be studied.
(5) The ecological effects of ocean disposal of chemical
process wastes. The quantities and types of wastes disposed
of in this manner should be determined, and their transport,
decomposition, and effect on the ocean environment should be
studied.
(6) The development of alternatives to landfill disposal.
It is probable that in the not too distant future, land
disposal of chemical wastes will be prohibited. At this
time alternative disposal methods should be available for
chemical wastes now disposed of in this manner.
247
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Industry statitics. pt. 1. Major groups 20-24. Washington, U.S.
Government Printing Office, Jan. 1971. p. 62-80.
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industry- groups and industries: 1967 and 1963. In 1967 Census of
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20-24. Washington, U.S. Government Printing Office, Jan. 1971.
p. 28-43.
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Census of manufactures, v. 2. Industry statistics, pt. 1. Major
groups 20-28. Washington, U. S. Government Printing Office. 1970.
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U.S. Government Printing Office, Aug. 1970. 40 p.
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production and sales, 1967. Preliminary Report. Washington, U.S.
Government Printing Office.
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Chemical Engineering Progress, 64(11):87-92, Nov. 1968.
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University of Houston, Mar. 26, 1970. 9 p.
253
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APPENDIX
TABLE 4 a
INDUSTRIAL CHEMICAL MANUFACTURE SIC #281 BY STATE AND REGION
I.
II.
III.
IV.
(U.
NEW ENGLAND
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
MIDDLE ATLANTIC
Delaware
New Jersey
New York
Pennsylvania
S. PUBLIC HEALTH SERVICE
1967
Value added by
manufacture
Millions Percent of
of dollars U.S. total
66 0.8
N.R.
N.R.
46 0.6
N.R.
19 0.2
N.R. N.R.
1334 17.2
N.R. N.R.
787 10.2
327 4.2
220 2.8
EAST SOUTH CENTRAL 1000 12.9
Kentucky
Maryland
North Carolina
Puerto Rico
Virginia
West Virginia
SOUTH ATLANTIC
Alabama
Florida
Georgia
Mississippi
South Carolina
Tennessee
179 2.3
88 1.1
46 0.6
N.R.
104 1.3
583 7.5
830 10.7
111 1.4
82 1.1
68 0.9
46 0.6
N.R.
522 6.7
REGIONS)*
1967
Number of
manufacturing plants
(20 employees or more)
Number
25
N.R.
N.R.
17
N.R.
8
N.R.
240
N.R.
128
52
60
90
18
21
15
N.R.
14
22
98
20
21
20
5
N.R.
32
Percent of
U.S. total
2.5
1.7
0.8
«—
24.3
t
12.9
5.3
6.1
9.1
1.8
2.1
1.5
1.4
2.2
9.9
2.0
2.1
2.0
.5
3.2
254
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TABLE 42 continued
V.
VI.
VII.
VIII.
IX.
of
EAST NORTH
CENTRAL
Illinois
Indiana
Michigan
Ohio
Wisconsin
WEST NORTH
CENTRAL
Iowa
Kansas
Minnesota
Missouri
Nebraska
North Dakota
South Dakota
WEST SOUTH
CENTRAL
Arkansas
Louisiana
New Mexico
Oklahoma
Texas
MOUNTAIN .
Colorado
Idaho
Montana
Utah
Wyoming
PACIFIC
Alaska
Arizona
California
Hawaii
Nevada
Oregon
Washington
TOTALS ALL STATES
Millions
dollars
1195
284
130
355
414
13
353
49
99
N.R.
162
43
N.R.
N.R.
2037
75
507
N.R.
7
1447
9
9
N.R.
N.R.
N.R.
N.R.
467
N.R.
6
303
N.R.
N.R.
21
137
7737*
Percent
of
U.S. total Number
15.4
3.7
1.7
4.6
5.3
0.2
4.6
0.6
1.3
-__
2.1
0.6
- —
...
26.3
1.0
6.5
0.1
18.7
0.1
0.1
_•_
6.0
0.1
3.9
__«
0.3
1.8
94**
184
53
23
30
70
8
50
9
14
N.R.
19
8
N.R.
N.R.
142
9
43
N.R.
5
85
9
6
N.R.
N.R.
3
N.R.
104
N.R.
3
81
N.R.
N.R.
6
14
989*
Percent
of
U.S. total
18.6
5.3
2.3
3.0
7.1
.8
5.1
N.R.
N.R.
- —
1.9
0.4
N.R.
•«
14.4
.9
4.3
.5
8.6
1.0
.6
___
.3
—
10.5
.3
8.2
_ —
___
.6
1.4
95.4**
N.R. - Not reported
*Totals including
those not
reported
**Percentages based on actual total;
for individual
states.
therefore do not equal 100 percent
*From Reference #66.
255
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