EPA-
Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the
MAJOR ORGANIC PRODUCTS
Segment of the Organic
Chemicals Manufacturing
Point Source Category
APRIL 1974
1 U.S. ENVIRONMENTAL PROTECTION AGENCY
\ ^vT/2 * Washington, D.C. 20460
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»*
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DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES
and
NEW SOURCE PERFORMANCE STANDARDS
for the
MAJOR ORGANIC PRODUCTS SEGMENT OF THE
ORGANIC CHEMICALS MANUFACTURING
POINT SOURCE CATEGORY
Russell E. Train
Administrator
James L. Agee
Acting Assistant Administrator for Water and Hazardous Materials
Allen Cywin
Director, Effluent Guidelines Division
John Nardella
Project Officer
April, 1974
Effluent Guidelines Division
Office of Water and Hazardous Materials
U.S. Environmental Protection Agency
Washington, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $3.60
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ABSTRACT
A study of the major organic chemicals segment of the organic
chemicals manufacturing industry was conducted by Roy F. Weston
Company for the Environmental Protection Agency. The purpose of
this study was to establish effluent limitations guidelines for
existing point source discharges and standards of performance and
pretreatment standards for new sources. This study and
subsequent proposed regulations were undertaken in fulfillment of
Sections 304, 306, and 307 of the Federal Water Pollution Control
Act Amendments of 1972.
For the purposes of this study, 41 major product-process segments
of the industry were investigated. These product-processes and
others significant segments to be covered in the second phase of
this study were categorized into four subcategories based on
process technology as related to process water requirements.
Industry segments were further subcategorized wherever
appropriate on the basis of raw waste loads. Effluent
limitations guidelines and standards of performance were then
developed for 7 subcategory groups which include 40 product-
processes on the basis of treatment and control technologies.
Supportive data and rationale for development of the proposed
effluent limitations guidelines and standards of performance are
contained in this report.
11
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CONTENTS
Section
"'ABSTRACT ii
CONTENTS iii
FIGURES V
TABLES x
I CONCLUSIONS 1
II RECOMMENDATIONS 27
III INTRODUCTION 33
Purpose and Authority 33
Methods for Development of the Effluent 34
Limitations Guidelines
Description of the Organic Chemicals Manufacturing 36
Water Usage Associated with Chemical Plants 47
Types of Manufacturing Processes 56
Relationship to Chemical Process Economics 59
IV INDUSTRY SUECATEGORIZATION 62
Discussion of the Rationale of Categorization 62
Descriptions of Subcategories 63
Basis for Assignment to Subcategories 64
Process Descriptions 69
V WASTE CHARACTERIZATION 244
VI SELECTION OF POLLUTANT PARAMETERS 265
ill
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CONTENTS (cont« d)
VII CONTROL AND TREATMENT TECHNOLOGIES 281
In-Process Systems 282
End-of-Pipe Treatment Systems 296
VIII COST, ENERGY, AND NON-WATER QUALITY ASPECTS 315
IX BEST PRACTICAL CONTROL TECHNOLOGY CURRENTLY AVAILABLE 327
EFFLUENT LIMITATIONS
X BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE 331
EFFLUENT LIMITATIONS
XI NEW-SOURCE PERFORMANCE STANDARDS 334
XII PRETREATMENT GUIDELINES 337
XIII ALLOWANCE FOR VARIABILITY IN TREATMENT PLANT PERFORMANCE 339
XIV ACKNOWLEDGEMENTS 343
XV BIBLIOBRAPHY 345
XVI GLOSSARY 354
IV
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FIGURES
.S2i Title
1-1 Subcategory A - Nonaqueous Processes 23
1-2 Subcategory B - Processes With Process Water 24
Contact as Steam Diluent or Absorbent
1-3 Subcategory C- Aqueous Liquid Phase 25
Reaction Systems
1-4 Subcategory D - Semicontinuous and 26
Batch Processes
111-1 Petrochemicals from Methane 42
111-2 Petrochemicals from Ethylene 43
111 - 3 Petrochemicals from Propylene and 44
Butylenes
111 - 4 Cyclic Petrochemicals 45
111 - 5 Plot Plan for Chemical Plant 51
Illustrating Four-Area Layout
111 - 6 Closed System 55
111-7 Relationship Between Selling Price 61
and Total Industry Production
IV - 1 Cyclohexane 70
IV - 2 Ethyl Benzene 73
IV - 3 Vinyl Chloride, Acetylene Addition 77
with Anhydrous Hydrogen Chloride
IV - 4 Benzene-Toluene-Xylene (BTX) from Petroleum 79
Naphtha
IV - 5 Ethylene, Propylene - Pyrolysis of 86
Ethane Propane Mix
IV - 6 Water Quench With Condensate Stripper 93
IV - 7 Water Quench Without Condensate Stripper 94
IV - 8 Butadiene, Dehydrogenation of n-Butane 99
IV - 9 Methanol 104
IV - 10 Acetone, Dehydrogenation of Isopropanol 109
v
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IV - 11 Acetaldehyde, Oxidative Dehydrogenation 113
IV - 12 Acetylene 117
IV - 13 Ethylene Oxide ' 120
IV - 14 Formaldehyde, Methanol Oxidation 125
IV - 15 Ethylene Bichloride (EDC) by Oxy- 131
chlorination and Direct Chlorination
IV - 16 Vinyl Chloride by Thermal Cracking of 135
Ethylene Dichloride
IV - 17 Styrene, Dehydrogenation of Ethyl Benzene 139
IV - 18 Styrene-Ethyl Benzene Distillation, 141
via Vacuum Two-Stage Steam Ejector
IV - 19 Styrene - Ethyl benzene Distillation, 142
Vacuum via Vacuum Pumps
IV - 20 Methylamines 149
IV - 21 Vinyl Acetate, from Ethylene and Acetic Acid 153
IV - 22 Phenol, via Cumene 157
IV - 23 Phenol,1 from Mono-Chlorobenzene 158
IV 24 Oxo-Chemicals 164
IV - 25 Acetaldehyde (Single-Stage Wacker Process) 168
IV - 26 Acetic Acid, Acetaldehyde Oxidation 172
IV - 27 Methacrylate - Acetone Cyanohydrin Process 176
IV - 28 Spent Acid Recovery Units 178
IV - 29 Ethylene Glycols, from Ethylene Oxide 184
IV - 30 Acrylic Acid, from Acetylene 188
IV - 31 Acrylates, from Alcohol 192
IV - 32 Terephthalic Acid (TPA), p-Xylene to Polymer 195
Grade TPA
IV T 33 Dimethyl Terephthalate, Esterification 201
of Terephthalic Acid
IV - 34 P-cresol 205
VI
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IV - 35 Aniline 209
IV - 36 Aniline Stripper 211
IV - 37 Bisphenol-A 215
IV - 38 Caprolactam 220
IV - 39 Long Chain Alcohol 225
IV - 40 Tetraethyl Lead 228
IV - 41 Coal Tar Distillation 232
IV - 42 Anthracene Refining 233
IV - 43 Pitch Forming 234
IV - 44 Extraction and Naphthalene Refining 235
IV - 45 Dyes 238
V - 1 Relationship Between BOD Raw Waste Load 249
and Flow RWL for Subcategory A
V - 2 Relationship Between COD RWL and Flow 250
RWL for Subcategory A
V - 3 Relationship Between TOG RWL and Flow 251
RWL for Subcategory A
V - 4 Relationship Between BOD RWL and Flow 254
RWL for Subcategory B
V - 5 Relationship Between COD RWL and Flow 255
RWL for Subcategory B
V - 6 Relationship Between TOC RWL and Flow 256
RWL for Subcategory B
V - 7 Relationship Between BOD RWL and Flow 258
RWL for Subcategory C
V - 8 Relationship Between COD RWL and Flow 259
RWL for Subcategory C
V - 9 Relationship Between TOC RWL and Flow 260
RWL for Subcategory C
V - 10 Relationship Between BOD RWL and Flow 263
RWL for Subcategory D
V - 11 Relationship Between COD RWL and Flow 264
RWL for Subcategory D
VI1
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VII - 1 Barometric Condenser 283
VII - 2 Process Steam Condensate 284
VII - 3 Noncondensible Removal 286
VII - U Water Scrubbing 287
VII - 5 Oil and Water Separation 288
VII - 6 Oil and Water Separation 289
VII - 7 BPCTCA Waste Treatment Model 310
VII - 8 BATEA Waste Treatment Model 311
Vlll
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TABLES
Table_No.. Title £aa£_N
1-1 chemicals Listed Under SIC Code 2815 5
1-2 Chemicals Listed Under SIC Code 2818 6
1-3 Products and Manufacturing Processes Listed 8
by Subcategory
1-4 Products and Processes Covered in Raw Waste 19
Load Sampling
1-5 Major RWL's of Pollutants Based on Contact 22
Process Wastewater
11-1 Subcategories based on Major Organic Chemicals 28
11-2 Effluent Limitations for BPCTCA 30
11-3 Effluent Limitations for BATEA 31
11-4 Effluent Limitation for New Sources 32
III - 1 Raw Materials Precursors, Intermediates Ul
and Finished Products Frequently
Found in the Organic Chemicals Industry
III - 2 Fifty Largest Chemical Producers in the 48
United States
III - 3 Establishments by Employment Size in the 49
Organic Chemicals Manufacturing Industry
IV - 1 U.S. Cyclohexane Capacity 71
IV - 2 Estimated Economic For Cyclohexane 71
IV - 3 U.S. Ethylbenzene Capacity 74
IV - 4 U.S. Benzene and Toluene Capacity 81
IV - 5 Xylene Capacity 84
IV - 6 U.S. Ethylene Capacity 88
IV - 7 Investment for Condensate Stripping 92
IV - 8 Incremental Operating Costs for Condensate 95
Strippers
IV - 9 U, c Ethylene Plants Using Condensate 97
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Strippers
IV - 10 U.S. Butadiene Capacity 102
IV - 11 Estimated Economics for Butadiene 102
IV - 12 U.S. Methanol Capacity (1972) 106
IV - 13 Estimated Economics for Methanol 107
IV - 14 U.S. Acetone Capacity 111
IV •* 15 Estimated Economics for Acetone 111
IV - 16 U. S. Acetaldehyde Capacity 115
IV - 17 U.S. Acetylene Capacity 118
IV - 18 U.S. Ethylene Oxide Capacity 122
IV - 19 Estimated Ethylene Oxide Economics 123
IV - 20 U.S. Formaldehyde Capacity 127
IV - 21 Estimated Economics for Formaldehyde 129
Production
IV - 22 U.S. Ethylene Dichloride Capacity (1972) 133
IV - 23 Estimated Economics for Ethylene Dichloride 133
IV - 24 U.S. Vinyl Chloride Capacity 136
IV - 25 Estimated Vinyl Chloride Economics 137
IV - 26 Operating Cost of Two-Stage Steam Ejectors 143
Styrene-Ethyl Benzene Distillation
IV - 27 Organic Compounds in Exhaust Air from Vacuum Pumps 144
IV - 28 Operating Costs for Vacuum Pumps 145
Styrene-Ethyl Benzene Fractionation
IV - 29 U.S. Styrene Capacity 146
IV - 30 Estimated Economics for Styrene 147
IV - 31 U.S. Methyl Amines Capacity (1970) 151
IV - 32 Estimated Economics fro Methylamines 151
IV - 33 U.S. Vinyl Acetate Capacity 154
IV - 34 Camparative Vinyl Acetate Economics 155
IV - 35 U.S. Phenol Capacity 161
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IV - 36 Estimated Economics for Phenol Production 162
IV - 37 U.S. Oxo-Chemicals Capacity 166
IV - 38 Estimated Economics for Oxo-Chemicals 166
IV - 39 Estimated Economics for Acetaldehyde 170
IV - 40 Acetic Acid Capacity (1972) 174
IV - 41 Economics of Spent Acid Recovery by 179
Neutralization
IV - 42 Economics of Spent Acid Recovery by 181
Complete Combustion
IV - 43 U.S. Methyl Methacrylate Capacity 182
IV - 44 Estimated Economics for Methyl Methacrylate 182
Production
IV - 45 U.S. Ethylene Glycol Capacity (1972) 185
IV - 46 Estimated Economics for Ethylene Glycol 186
IV - 47 U.S. Acrylic Acid and Acrylates Capacity 190
IV - 48 Estimated Acrylic Acid Economics 190
IV - 49 U.S. Terephthalic Acid Capacity 198
IV - 50 Estimated Economics for Terephthalic Acid 199
IV - 51 U.S. Dimethyl Terephthalate Capacity 206
IV - 52 U.S. Cresol Capacity (1972) 207
IV - 53 Economic Evaluation of Activated Carbon 207
System for Wastewater from p-Cresol
IV - 54 Aniline Stripper Economics 212
IV - 55 U.S. Aniline Capacity (1972) 213
IV - 56 Estimated Economics for Aniline 213
IV - 75 U.S. Bisphenol-A Capacity 217
IV - 58 Estimated Economics for Bisphonol-A 218
IV - 59 U.S. Caprolactam Capacity 222
IV - 60 Estimated Economics for Caprolactam 223
XI
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IV - 61 U.S. Long-Chain Alcohol Capacity 226
IV - 62 U.S. Tetraethyl Lead Capacity 230
IV - 63 Estimated Economics for Tetraethyl Lead 230
IV - 64 U.S. Production of Dyes, by Classes of 239
Application, 1965
IV - 65 U. S. Production and Sales of Dyes, by Chemical 240
Classification, 1964
IV - 66 Production and Shipment of Selected Pigments 241
in the United States, 1958 and 1963
V - 1 Subcategory A Raw Waste Load Data 248
V - 2 Subcategory B Raw Waste Load Data 253
V - 3 Subcategory C Raw Waste Load Data 257
V - 4 Subcategory D Raw Waste Load Data 262
VI - 1 List of Pollutants Examined for the Organic 267
Chemicals Industry
VI - 2 Miscellaneous RWL Loads for Subcategory B 277
VI - 3 Miscellaneous RWL Loads for Subcategory C 27$
VII - 1 Typical Efflicincies of Oil Separation 291
Units
VII - 2 Organic Chemical Study Treatment Technology 297
Survey
VII - 3 Historic Treatment Plant Performance Data 298
VII - 4 Treatment Plant Survey Data 300
VII - 5 Removal Efficiency by Filtration 302
VII - 6 Activated Carbon Plants Treating Raw Waste Waters 303
VII - 7 Summary COD Carbon Isotherm Data 305
VII - 8 Summary BOD Carbon Isotherm Data 306
VII - 9 Summary TOG Carbon Isothern Data 307
VII - 10 BPCTCA Model Treatment System Design Summary 312
VII - 11 BATEA End-of-Pipe Treatment System Design Summary 314
Xll
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VIII - 1 Total Capital and Annual Costs - BPCTA 319
VIII - 2 Total Costs and Effectiveness - BPCTA 320
VIII - 3 Total Capital and Annual Costs for 324
New Sources (BADCT)
VIII - U Total Capital and Annual Costs - BATEA 326
IX - 1 Effluent Limitations - BPCTCA 330
X - 1 Effluent limitations - BATEA 333
XI - 1 Effluent Limitations for New 336
Sources (BADCT)
XIII - 1 Effluent Variation of Biological Treatment 340
Plant Effluent
Xlll
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SECTION I
CONCLUSIONS
The organic chemicals manufacturing industry is a complex one in
which interrelated chemicals compete for raw materials and
markets via increasingly complex technologies. The water usage
and subsequent waste water discharges are closely related to this
mix of products and processes. The effluent limitations
guidelines and standards presented in this document were
developed with full recognition of these complexities.
The industry is net readily defined in terms of the Standard
Industrial Classification (SIC) system. However, commodities
included under SIC 2815 (Cyclic Intermediates and Crudes) and SIC
2818 (Industrial Organic Chemicals) provide a reasonable
approximation and have been used to define the limitations of the
industry for the current study. Primary petrochemical
processing, plastics, fibers, agricultural chemicals, pesticides,
detergents, paints, and Pharmaceuticals have been excluded.
Lists of the specific products covered by SIC 2815 and 2818 are
presented in Tables 1-1 and 1-2.
The diversity of products and manufacturing operations to be
covered indicates the need for separate effluent limitations for
different segments within the industry. To this end, process-
oriented subcategories have been developed as follows:
Subcategory^A Nonaqueous Processes
Contact between water and reactants or products is minimal.
Water is not required as reactant or diluent, and is not formed
as a reaction product. The only water usage stems from periodic
washes or catalyst hydration.
£l Process with Process Water Contact as Steam
Absorbent
Process water is in the form of dilution steam, direct product
quench, or absorbent for effluent gases. Reactions are all
vapor- phase over solid catalysts. Most processes have an
absorber coupled with steam stripping of chemicals for
purification and recycle.
Subcategory_C; Aqueous Liquid-Phase Reaction Systems
Reactions are liquid- phase, with the catalyst in an aqueous
medium. Continuous regeneration of the catalyst requires
extensive water usage, and substantial removal of spent inorganic
by-products may be required. Additional 'process water is
involved in final purification or neutralization of products.
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§ub.£3£§22£.Y_P. • Batch and Semi continuous Processes
Many reactions are liquid-phase with aqueous catalyst systems.
Requirements for very rapid process cooling necessitate
provisions for the direct addition of contact quench water or
ice. Reactants and products are transferred from one piece of
equipment to another by gravity flow, pumping, or pressurization.
Much of the materials handling is manual, and there is only
limited use of automatic process controgL. Filter presses and
centrifuges are commonly used for solid-liquid separations, and
air or vacuum ovens are used for drying. Cleaning of
noncontinuous production equipment constitutes a major source of
waste water.
Sample flow diagrams illustrating typical unit operations and
chemical conversions for a process in each subcategory are
provided in Figures 1-1, 2, 3, and U. Table 1-3 is a
comprehensive listing of the chemicals and processes assigned to
each subcategory. The products and processes covered in Phase I
are listed, by subcategory, in Table 1-4. The raw waste load
(RWL) data obtained in the field surveys are summarized in Table
1-5. Subcategories B and C were further subcategorized on the
basis of raw waste loads. For subcategories B and C, product-
processes were classified by subcategory groups: Bl, B2, Cl, C2,
C3, and CU. The groups consist of porduct-process segment with
similar raw waste load characteristics for the major pollutant
parameter, BODS. Effluent limitations and guidelines for
Subcategory D have been deleted from Phase I regulations as a
result of the limited available data base and will subsequently
be covered in Phase II proposed regulations.
The effluent limitations proposed herein are based primarily on
the dissolved organic pollutant contaminants in the process waste
waters associated with the processes listed in the various
subcategories. No specific limitations are proposed for
pollutants associated with noncontact waste waters, such as
boiler and cooling tower. These are primarily inorganic
materials, and it is difficult to allocate such wastes among
specific processes in many multi-product plants. Since raw waste
loads are based on process waste waters, it is assumed that all
noncontact waters be segregated from process waste waters.
Otherwise, combined waste waters are subject to effluent
limitations.
Separate limitations are presented for each of the seven
subcategory groups. The parameters involved are: biochemical
oxygen demand (BOD5), chemical oxygen demand (COD), total
suspended solids (TSS) and phenols.
Other possible RWL parameters were considered during the study:
total organic carbon, ammonia, cyanide, extractable oils and
various metals, but were found to be in concentrations
substantially lower than those which would require specialized
end-of-pipe for the entire industry. Effluent limitations are
not established for cyanide and cadmium pollutants although these
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have been designated as toxic substances. It is expected that
the best practicable control technology currently available end-
of-process treatment will substantially reduce these pollutants
in the effluent stream. Effluent standards will be established
for toxic pollutants wherever applicable.
Effluent Limitations for the Best Practicable Control Technology
Currently Available and New Source Performance Standards (BADCT)
were based upon three significant pollutant parameters: BOD!5,
total suspended solids (TSS) and phenols. Effluent limitations
guidelines for phenolic compounds applicable only to the cumene
process, bisphenol A, and p-cresol manufacturing for BPCTCA,
BATEA and BADCT. The application of alternate oxygen demand
parameters such as COD or TOC in lieu of the BOD5 parameter may
be possible, in situations where a direct correlation with BOD.5
has been satisfactorily established. For Best Available
Technology Economically Achievable, four significant pollutant
parameters are specified: BOD5, COD, TSS, and phenols.
End-of-process treatment for the 1977 standard is defined as
biological treatment as typified by current exemplary processes:
activated sludge, trickling filters, aerated lagoons, and
anaerobic lagoons. These systems will be adequately equipped
with pH control and equalization in order to control variable
waste loads and clarification with the addition of chemicals to
aid in removing suspended solids where this is required. These
systems do not preclude the use of equivalent chemical-physical
systems such as activated carbon in situations where necessary
land area is not available. Additionally, suitable in-process
controls are also applicable for the control of those pollutants
which are inhibitory to the biological waste treatment system.
Best Available Technology Economically Achievable, BATEA, (1983
Standard) is based upon the addition of activated carbon to
biological systems. This technology is based upon substantial
reductions of dissolved organics compounds which are
biorefractory as well as those which are biodegradable.
Exemplary in-process systems are also applicable to this
technology. End-of-process activated carbon treatment does not
preclude the use of such treatment as an in-process technology.
The following in-process controls are applicable to BATEA:
1. the substitution of noneontact heat exchangers for direct
contact water cooling;
2. the use of nonaqueous quench media as a substitute for
water where direct contact quench is required;
3. the recyle of process water, such as between absorber and
stripper;
U. the reuse of process water (after treatment) as a make-up
to evaporative cooling towers through which noncontact
cooling water is circulated;
5. the use of process water to produce low pressure steam by
non-contact heat exchangers in reflux condensers of
distillation columns;
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6. the recovery of spent acids or caustic solutions for
reuse;
7. the recovery and reuse of spent catalyst solutions; and
8. the use of nonaqueous solvents for extraction of
products.
End-of-process technology for new sources utilizing the best
available demonstrated control technology (BADCT) is defined as
biological treatment with suspended solids removal via
clarification, sedimentation, sand, or dual-media filtration. In
addition, exemplary in-process controls, as previously
enumerated, are also assumed to be applicable, particularly where
biotoxic pollutants must be controlled. This technology does not
preclude the use of equivalent chemical-physical systems such as
activated carbon as either an in-*proces or end-*of -process
treatment. This may be advantageous in areas where land
availability is limited.
Effluent limitations for BPCTCA, BATEA, and New Sources {BADCT)
were developed on the basis of mean subcategory group raw waste
loads and the degree of reduction achievable by each level of
technology. Performance of exemplary treatment plants were
considered in deriving the BPCTCA limitations for each category.
Performance of BATEA and BADCT systems, together with in-process
controls were considered in determining effluent limitations for
each level of technology. It was determined that Subcategories B
and C would be further subcategorized on the basis of raw waste
loads. In these cases, median raw waste loads for subcategory
groups were determined for Bl, B2, Cl, C2, C3 and CU.
Finally, time based effluent limitations were derived on the
basis of the maximum of any one day and the maximum average of
daily values for a period of thirty consecutive days. The
factors used in deriving these time based limitations were
determined from long term performance (i.e. daily, weekly,
monthly) from the test treatment systems evaluated. Time based
limitations consider the normal variations of exemplary designed
and operated waste treatment systems.
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Table l-l
Chemicals Listed Under SIC Code 2815
Cyclic Intermediates, Dyes, Organic Pigments (Lakes and
Toners), and Cyclic (Coal Tar) Crudes
Acid dyes, synthetic
Acids, coal tar: derived from coal
tar distillation
Alkylated diphenylamines, mixed
Alkylated phenol, mixed
Aminoanthraquinone
Ami noazobenzene
Ami noazotoluene
Aminophenol
Ani1i ne
Ani1ine oil
Anthracene
Anth raqu i none dyes
Azine dyes
Azobenzene
Azo dyes
Azoic dyes
Benzaldehyde
Benzene, product of coal tar dis-
til lation
Benzoic acid
Benzol, product of coal tar distilla-
tion
Biological stains
Chemical indicators
Chips and flakes, naphthalene
Chlorobenzene
Chloronaphthalene
Chlorophenol
Chlorotoluene
Coal tar acids, derived from coal
tar disti1lation
Coal tar crudes, derived from coal
tar disti1lation
Coal tar distillates
Coal tar intermediates
Color lakes and toners «
Color pigmen-ts, organic: except
animal black and bone black
Colors, dry: lakes, toners, or full
strength organic colors
Colors, extended (color lakes)
Cosmetic dyes, synthetic
Cresols, product of coal tar distilla-
tion
Creosote oil, product of coal tar dis-
tillation
Cresylic acid, product of coal tar
distillation
Cyclic crudes, coal tar: product of
coal tar distillation
Cyclic intermediates
Cyclohexane t.
Diphenylamine
Drug dyes, synthetic
Dyes, synthetic organic
Eosine toners
Ethyl benzene
Food dyes and colors, synthetic
Hydroquinone
Isocyanates
Lake red C toners
Lithol rubine lakes and toners
Maleic anhydride
Methyl violet toners
Naphtha, solvent: product of coal
tar disti1lation
Naphthalene, product of coal tar
disti1lation
Naphthol, alpha and beta
Naphtholsulfonic acids
Nitroani1ine
Nitrobenzene
Nitro dyes
Ni trophenol
Nitroso dyes
Oils: light, medium, and heavy—
product of coal tar distillation
Orthodichlorobenzene
Paint pigments, organic
Peacock blue lake
Pentach1o rophenol
Persian orange lake
Phenol
Phloxine toners
Phosphomolybdic acid lakes and
toners
Phosphotungstic acid lakes and
toners
Phthalic anhydride
Phthalocyanine toners
Pigment scarlet lake
Pigments, organic: except animal
black and bone black
Pitch, product of coal tar distilla-
tion
Pulp colors, organic
Quinoli ne dyes
Resorcinol
Scarlet 2 R lake
StiIbene dyes
Styrene
Styrene monomer
Tar, product of coal tar distillation
Toluene, product of coal tar distilla-
tion
Toluol, product of coal tar distil-
lation
Toluidines
Toners (reduced or full strength
organic colors)
Vat dyes, synthetic
Xylene, product of coal tar distil-
lation
Xylol, product of coal tar distilla-
tion
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Table 1-2
Chemicals Listed Under SIC Code 2818
Industrial Organic Chemicals, Not Elsewhere Classified
Accelerators, rubber processing:
cycli c and acycli c
Acetaldehyde
Acetates, except natural acetate of
cl ime
Acetic acid, synthetic
Acetic anhydride
Acetin
Acetone, synthetic
Acids, organic
Acrolein
Acryloni tri1e
Adipic aci d
Adiponi trile
Alcohol, aromatic
Alcohol, fatty: powdered
Alcohols, industrial: denatured
(nonbeverage)
Algin products
Amines of polyhydric alcohols, and
of fatty and other acids
Amyl acetate and alcohol
Antioxidants, rubber processing:
cycli c and acyclic
Bromochloromethane
Butadiene, from alcohol
Butyl acetate, alcohol, and pro-
pionate
Butyl ester solution of 2, 4-D
Calcium oxalate
Camphor, synthetic
Carbon bisulfide (disulfide)
Carbon tetrachloride
Casing fluids, for curing fruits,
spices, tobacco, etc.
Cellulose acetate, unplasticized
Chemical warfare gases
Chloral
Chlorinated solvents
Chloroacetic acid and metallic salts
Chloroform
Chloropierin
Ci tral
Citrates
Ci t ri c acid
Citronellol
Coumarin
Cream of tartar
Cyclopropane
DDT, technical
Decahydronaphthal ene
Dichlorodiflouromethane
Diethylcyclohexane (mixed isomers)
Diethylene glycol ether
Dimethyl divinyl acetylene (di-
isopropenyl acetylene)
Dimethylhydrazine, unsymmetrical
Enzymes
Esters of phthalic anhydride: and
of phosphoric, adipic, lauric,
oleic, sebacic, and stearic acids
Esters of polyhydric alcohols
Ethanol, industrial
Ether
Ethyl acetate, synthetic
Ethyl alcohol, industrial (non-
beverage)
Ethyl butyrate
Ethyl cellulose, unplasticized
Ethyl chloride
Ethyl ether
Ethyl formate
Ethyl nitrite
Ethyl perhydrophenanthrene
Ethylene
Ethylene glycol
Ethylene glycol ether
Ethylene glycol, inhibited
Ethylene oxide
Ferric ammonium oxalate
Flavors and flavoring materials,
synthetic
Fluorinated hydrocarbon gases
Formaldehyde (formalin)
Form/ic acid and metallic salts
Freon
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Table 1-2
(continued)
Fuel propellants, solid organic
Fuels, high energy, organic
Gases, fluorinated hydrocarbon
Geraniol, synthetic
Glycerin, except from fats (syn-
thetic)
Grain alcohol, industrial
Hexamethy1ened i am i ne
Hexamethy1enetetrami ne
High purity grade chemicals, or-
ganic: refined from technical
grades
Hydraulic fluids, synthetic base
Hydrazine
Industrial organic cyclic compounds
lonone
Isopropyl alcohol
Ketone, methyl ethyl
Ketone, methyl isobutyl
Laboratory chemicals, organic
Laurie acid esters
Lime citrate
Malononitrile, technical grade
Metallic salts of acyclic organic
chemicals
Metal 1ic stearate
Methanol, synthetic (methyl alco-
hol)
Methyl chloride
Methyl perhydrofluorine
Methyl salicylate
Methylamine
Methylene chloride
Monochlorod i f1uoromethane
Monomethylparaminophenol sulfate
Monosodium glutamate
Mustard gas
Nitrous ether
Normal hexyl decalin
Nuclear fuels, organic
Oleic acid esters
Organic acids, except cyclic
Organic chemicals, acyclic
Oxalates
Oxalic acid and metallic salts
Pentaerythri tol
Perch 1o roethy1ene
Perfume materials, synthetic
Phosgene
Phthalates
Plasticizers, organic: cyclic and
acyclic
Polyhydric alcohols
Potassium bitartrate
Propellants for missiles, solid, or-
ganic
Propy1ene
Propylene glycol
Quinuclidinol ester of benzylic acid
Reagent grade chemicals, organic:
refined from technical grades
Rocket engine fuel, organic
Rubber processing chemicals, or-
ganic: accelerators and antioxi-
dants—cyclic and acyclic
Saccharin
Sebacic acid
Si 1icones
Soaps, naphthenic acid
Sodium acetate
Sodium alginate
Sodium benzoate
Sodium glutamate
Sodium pentachlorophenate
Sodium sulfoxalate formaldehyde
Solvents, organic
Sorbitol
Stearic acid esters
Stearic acid salts
Sulfonated naphthalene
Tackifiers, organic
Tannic acid
Tanning agents, synthetic organic
Tartaric acid and metallic slats
Tart rates
Tear gas
Terpineol
Tert-butylated bis (p-phenoxy-
phenyl) ether fluid
Tetrachloroethylene
Tetraethyl lead
Thioglycolic acid, for permanent
wave lotions
Tri chloroethylene
Trichloroethylene stabilized, de-
greasing
Trichlorophenoxyacetic acid
Trichlorotrifluoroethane terachloro-
difluoroethane isopropy1 alcohol
Tricresyl phosphate
Tridecyl alcohol
Trimethyltrithiophosphite (rocket
propellants)
Triphenyl phosphate
Urea
Van! 11 in, synthetic
Vinyl acetate
-------
Table 1-3
Products and Manufacturing Processes Listed by Subcategory
Product Manufacturing Process
Subcategory A (Continuous Non-Aqueous Processes)
Mixed aromatics with saturates
(reformate)
Mixed aromatics concentrate
Benzene
Toluene
Mixed xylenes (o-X,- m-X, p-X, EB)
Ortho-xylene
Para-xylene
Petroleum naphthalene
Ethyl benzene
Cumene
Cyclohexane
Phosgene
Ethyl chloride
Cyclopropane
Hydrogenation of pyrolysis gasoline
from ethylene manufacture
Naphtha reforming
Solvent extraction
Fractional distillation
Toluene disproportionation
Toluene hydrodealkvlation
Fractional distillation
Fractional distillation
Toluene disproportionation
Fractional distillation
Fractional distillation
Isomerization
Crystallization and filtration
Fractional distillation
Hydrodealkylation of alkyl
naphthalenes
Alkylation of benzene with
ethylene
Alkylation of benzene with
propylene
Hydrogenation of benzene
CO and chlorine synthesis
Hydrochlorination ot euiyiene
Chlorination of ethane
Extraction from LPG gas
Subcategory B (Continuous Vapor Phase Processes)
WHERE WATER IS USED AS DILUENT OR ABSORBENT)
Ethylene
Propylene
Butadiene
Methanol
Ethanol
Isopropanol
Acetone
Maleic anhydride
Pyrolysis of hydrocarbons
Pyrolysis of hydrocarbons
Pyrolysis of hydrocarbons
Dehydrogenation of N-butane,
N-butylene (catalytic with
steam d!lution)
Catalytic oxidative dehydrogenation
Purification by extractive dis-
tillation
Steam reforming of natural
gas--CO & CO. synthesis
Catalytic hydration of ethylene
Catalytic hydration of propy 1 ere
Dehydrogenation of isopropanol
Air oxidation of benzene or butene
-------
Table 1-3
Product
Subcategory B (continued)
Phthalic anhydride
Mdnufacturinq Process
Acetaldehyde
Acetylene
Acetic anhydride
Ethylene oxide
Acryloni tri le
Formaldehyde
Acrylic acid
Ethylene dichloride
Vinyl chloride
Ethyl ether
Isoprene
Vinyl acetate
Mixed cresols and xylenols
Methyl amines
Methyl halides
Dichlorodi fluoromethane
Fluorinated hydrocarbons
Trlchlorotrifluoroethane
Phthalates
Hexamethy1ened i am i ne
Air oxidation of ortho-xylene
or naphthalene
Oxidative-de.hydration of ethanol
Calcium carbide process
Wulff process (thermal cracking)
BASF process (methane partial
oxidat ion)
Absorption of ketone (by cracking
of acetic acid) in acetic acid
Catalytic oxidation of ethylene
Ammoxidation of propylene
Oxidation of methanol
Catalytic oxidation of propylene
Oxychlorination of ethylene by
HC1
Direct chlorination of ethylene
Thermal cracking of ethylene
dichloride
Acetylene and anhydrous HC1
By-product of ethanol production
via catalytic hydration of
ethylene
P ropy 1ene d i me r i iat i on/i some r i zat i on/
cracking
Dehydrogenation of 1 seamy 1ene
Acetylene and acetic acid process
Vapor phase ethylene and acetic
acid process
Phenol and methanol synthesis
Methanol and ammonia reacted over
dehydration catalyst
Gaseous methanol and halogen acid
passed through thermal converter
Reaction of hydrofluoric acid
with chloroform
Reaction of hydrofluoric acid
with carbon tetrachloride
Reaction of perchloroethylene
and hydrofluoric acid
Reaction of phthalic anhydride
and alcohol
From adipic acid by reaction with
NH_ followed by hydrogenation of
adfponitrile
From butadiene
From acryloni t ri le
-------
Product
Urea
Acrolein
Ally! chloride
Fatty acids
Fatty amines
Table 1-3
(cont inued)
Manufacturing Process
Subcategory B (Continued)
NH and CO synthesis
Direct oxidation of ethylene
High temperature chlorinatton
of propy lene
Oxidation of N-paraffins
Ammoniation of fatty acid
followed by catalytic
hydrogenation of aminonitriles
Benzoic acid
Benzaldehyde
Chloronaphthalenes
Higher alcohols
Methyl and ethyl acrytates
Trichloroethylene
Tetrachloroe thy lene
Chloroform
Methyl chloride
P/0-dichlorobenzene
Glycerol
Hexamethylene tetramine
Decahydronaphthalene
Carbon tetrachloride
Carbon bisulfide (disulfide)
Benzene hexachloride
Air oxidation of toluene in L.P.
Air oxidation of toluene V.P.
Chlorination of naphthalenes
High-pressure hydrogenolysls
Acetylene, nickel carbonyl and
methyl or ethyl alcohol
Catalytic-thermal dehydrochlor-
ination of tetrachloroethane
Chlorination of ethylene to 1, 2
dlchloroethane and conversion
to T.C.E.
Chlorination of methane in atmosphere
of carbon tetrachloride
High temperature Chlorination of
ethylene dichloride
Methane Chlorination
Direct methane Chlorination
Esterification of methanol with
hydrochloric acid
Chlorination of chlorobenzene
Hydrolysis of epichlorohydrin
with NaOH
Catalytic hydrogenation of nlgor
From acrolein and isopropanol
NH + formaldehyde
Hydrogenation of naphthalene
Chlorination of carbon disulfide
From chlorinated methanes production
Sulfur and methane
Sulfur and charcoal in electric
arc furnace
Benzene Chlorination in presence
of actimic 1ight
10
-------
Table 1-3
(continued)
Product
Manufacturing Process
Subcategory C (continued)
Acetophenone
Acrolei n
Ethylacetate
Propyl acetate
Acetin (glyceryl monoacet
-------
Table 1-3
(continued)
Product Manufacturing Process
Subcategory C (Liquid Phase Reaction Systems)
Ethanot Sulfuric acid hydrolysis of ethylene
Isopropanol Sulfuric acid hydrolysis of
propylene
Acetone Cumene oxidation with cleavage of
hydroperoxide in sulfuric acid
Phenol Raschig process
chlorobenzene process
Sulfonation process
Cumene oxidation with cleavage
of hydroperoxide in sulfuric
acid
Oxo-chemicals
Includes: N-buty! alcohol
Isobutyl alcohol
2-ethyIhexanol
Isooctyl alcohols
Decyl alcohols
Acetaldehyde
Acetic acid
Methyl ethyl ketone
Methyl methacrylate
Ethylene oxide
Acryloni tri le
Ethylene glycol
Acryl ic acid
Ethyl acrylate
Styrene monomer
Adiptc acid
Oxo-process (carbonylation and
condensation)
Ethylene oxidation via Wacker
process
Oxidation of LPG (butane)
Oxidation of acetaldehyde
Carbonylation of methanol
Sulfuric acid hydrolysis of
butene-2, dehydrogenation of
sec-butanol
Oxidation of LPG (butane)—By-
product of acetic acid manufacture
Acetone cyanohydrin process
Chlorohydrin process
Acetylene-HCN process
Sulfuric acid catalyzed hydration
of ethylene oxide
CO synthesis with acetylene
Acetylene and ethanol in presence
of nickel carbonyl catalyst
Oxidation of propylene to acrylic
acid followed by esterification
Reaction of ketone with formalde-
hyde followed by esterification
Alkylation of benzene with ethylene,
dehydrogenation of ethylbenzene
with steam
Oxidation of cyclohexane/cyclohexanol/
cyclohexanone
Direct oxidation of cyclohexane
wi th ai r
12
-------
Product
Table 1-3
(continued)
Subcategory C (continued)
Manufacturing Process
Terephthalic acid
Dimethyl terephthalate
Para-cresol
Cresy 1 ic acids
Aniline
Chloroprene
Bis-phenol-a
Propylene oxide
Propylene glycol
Vinyl acetate
Anthraquinone
Beta naphthol
Caprolactam
Toluene di-isocyanate
Si 1icones
Oxidation of para-xylene with
nitric acid
Catalytic oxidation of para-xylene
Esterification of TPA with methanol
and sulfuric acid
Vapor phase methylation of phenol
Oxidation of para-cymene with
cleavage in sulfuric acid
Caustic extraction from cracked
naphtha
Nitration of benzene with nitric
acid (L.P.), hydrogenation
of nitrobenzene
Dimerization of acetylene to vinyl
acetylene followed by hydro-
chlorination
Vapor phase chlorlnation of butadiene
followed by isomerization and
reaction
Condensation of Phenol and Acetone
in presence of HC1
Addition of propylene and CO- to
agueous calcium hypochlorite
Liquid phase oxidation of isobutane
followed by liquid phase epoxi-
dation
Hydration of propylene oxide
catalyzed by dilute H2SOJ+
Liquid phase ethylene and acetic
acid process
Catalytic air oxidation of
anthracene
Naphthalene sulfonation and
caustic fusion
Hydroxyl amine production,
cyclohexanone production,
cyclohexanone oximation,
oxime rearrangement, purification,
and ammonium sulfate recovery
Toluene nitrification, toluene
diamine production, HC1
electrolysis, phosgene production,
TDI production, purification
Reaction of silicon metal
with methyl chloride
13
-------
Table 1-3
(cont i nut:d}
.Product
Naphthemic acids
Ethyl cellulose
Cellulose acetate
Chlorobenzem0
Chlorophenol
Chlorototuene
Hydroquinone
Naphthosulfonic acids
Ni trobenzene
Amyl acetate
Amy) alcohol
Ethyl ether
Ethyl butyrate
Ethyl formate
Tetraethyl lead
Formic acid
Methyl isobutyl ketone
Naphthol
Pentachlorophenol
Soduim pentachlorophenate
Han_ufacturing Process
Subcategory C (continued)
From gas-oil fraction of
pet roleum•• by extraction with
caustic soda solution and
acidi ficat ion
From alkali cellulose and ethyl
chloride or sulfate
Ace.tyiation of cellulose with
acetic acid (followed by
saponification with sulfuric
acid for diacetate)
Raschig process
Direct chlorination of phenol
From chloroani1ine through
diazonium salt
Catalytic chlorination of toluene
Oxid. of aniline to quinone
followed by hydrogenation
Sulfonation of B-naphthol
Caustic fusion of naphthalene
sulfonic acid
Benzene and HNO, in presence
of sulfuric acid
Esterification of amyl alcohol
with acetic acid
Pentane chlorination and
alkalin hydrolysis
Dehydration of ethyl alcohol by
sulfuric acid
Esterification of ethyl alcohol
with butyric acid
Esterification of ethyl alcohol
with formic acid
Reduction of ethyl chloride with
amalgam of Na and Pb
Sodium hydroxide and carbon
monoxide
Dehydration of acetone alcohol
to mesityl oxide followed by
hydrogenation of double bond
High-temperature sulfonation of
naphthalene followed by
hydrolysis to B-naphthol
Chlorination by phenol
Reaction of caustic soda with
pentachlorophenol
14
-------
Table 1-3
(conti nued)
Product
Toluidines
Hydrazi ne
Oxalic acid
Oxalates
Sebacic acid
Giycerol
Diethylene glycol diethyl ether
Manufacturing Process
Subcategory C (continued)
Reduction of nitrotoluenes
with Fe and H SO^
Indirect oxidation of ammonia
with sodium hypochlorite
Sodium formate process
Sodium formate process
Caustic hydrolysis of ricinoleic acid
(castor oi1)
Acrolein epoxidation/reduction
followed by hydration
Propylene oxide to allyl alcohol
followed by chlorination
Ethylene glycol and ethyl alcohol
condensation dehydration
Dichloro-diphenyl-trichloroethane (DDT) Monochlorobenzene and chloral
in presence of sulfuric acid
Pentach1oroethy 1ene
Methylene chloride
Pentaerythri tol
Chloral (trichioroacetic aldehyde)
Triphenyl phosphate
Tridecyl alcohol
Tricresyl phosphate
Ami 1 alcohol
Acrylamide
Higher alcohols
synthetic amino acids
Organic esters
Trialkylacetic acids
Fatty acids
Laurie acid esters
Oleic acid esters
Chlorination of acetylene
Methane chlorination
Methanol esterification
followed by chlorination
Acetaldehyde and formaldehyde in
presence of basic catalyst
Chlorination of acetaldehyde
Phenol and phosphorous oxychloride
From propy 1 ene tetramer
Cresylic acid and phosphorous
oxychloride
Chlorination of pentanes and
hydrolysis of amyl chlorides
Acrylonitrile hydrolysis with
Sodium reduction process
Acrolein and mercaptan followed
by treatment with Na_CO, and
NaCN i
Alcohol and organic acid, HLSO^f
catalyst
Olefins and CO followed by hydrolysis
Batch or continuous hydrolysis
Esterification of lauric acid
Esterification of oleic acid
15
-------
Table 1-3
(conti nued)
Product
Manufacturing Process
Subcategory C (continued)
I socyanates Phosgene and Amines
Coal tar cyclic intermediates Coal tar distillation
Subcategory D (Batch Processes)
C ouma r i n
Resorcinal
Phosphotungstic acid lakes
Methyl violet
Lake red
Lithol rubine
Eosin toners
Amino anthraquinone
Ami no azobenzene (para)
Aminoazotoluene (ortho)
Amino phenol (0, M, P)
Anthraquinone (dyes)
Azine dyes
Heating salicylic aldehyde,
sodium acetate, and acetic
anhydride
Fusing benzene-meta-disulfonic
acid with sodium hydroxide
Precipitation of basic dyestuffs
with solutions of phosphotungstic
acid
Derivatives of paranosani1ine
Coupl ing 2-chloro-5-aminotoluene-it
sulfonic acid with B-naphthol
Diazotization of p-toluidine
meta sulfonic acid followed
by coupling with 3-hydropy-2-
naphthic acid
Bromination of fluorescin
Reduction of nitroanthraquinone
Substitution of sulfonate with
ami no group
Catalytic heating of diazoamino-
benzene
Aniline solution and aniline
hydrochloride
From o-toluidine by treatment
with nitrite and HC1
(meta) Fusion of sulfanilic acid
with NaOH and ether extraction
(ortho) H.S reduction of 0-nitro-
phenol and aqueous ammonia
(para) Reduction of p-nitrophenol
by Fe and HC1
Electrolytic reduction of nitro-
benzene in sulfuric acid
Heating phthalic anhydride and
benzene in presence of A1C1,
catalyst and dehydrating
From phenazine
16
-------
Product
Table 1-3
(con'.! r;-icd)
Subcategory D (continued)
fianuf ucturi :iq Process
Azobenzene
Azo dyes (generic)
Monosodium glutamates
Flavors
Camphor, synthetic
Cltral
Citric acid
Lime citrate (calcium citrate)
Citronellol
Peacock blue
0/P nitrophenol
Vanillin
Diphenylamine
Alkylated diphenylamines
Ethyl nitrite
Ferric ammonium oxalate
Calcium oxalate
Calcium steatite
Methyl sal icy late
Calcium tartrate
n of nitrobenzene with
sodi'.im '.tj
-------
Product
Table 1-3
(continued)
Subcategory D (continued)
Manufacturing Process
Alkylated phenols
Acetamide
Organic esters
Nit roani1ine
Sorbitol
Terpineol
Saccharin
Tannic acid
Algin (sodium alginate)
Mustard gas (dichlorodiethyl sulfide)
lonone
Geraniol
Sodium citrate
Calcium citrate
Cream of tartar (potassium bitartrate)
Dimethyl hydrazine
Nltrophenol
Alkylation with lewis acid
catalyst
Distillation of ammonium acetate
Steam distillation of naturally
occuring esters
p-nitrochlorobenzene and ammonia
Hydrogenation of fructose-free
glucose
Hydratlon of pinene
From o-toluene sulfonamide
From phthalic anhydride via
anthrani 1 ic acid
Extraction of powdered nutgalls
Extraction from brown algae
Ethylene and sulfur chloride
Thyoglycol and hydrogen chloride
Condensation of citronellal from
lemon-grass oil with acetone
From geranium oil, citronellal
and palmarosa
From myrcene
Sodium sulfate and calcium citrate
By-product In manufacture of
citric acid
From argols by extraction with
water
Dimethylamine and chloramine
Dimethylamine and sodium nitrite
followed by reduction
Catalytic oxidation of dimethyl-
ami ne and ammonia
Nitrochlorobenzene and caustic
soda
18
-------
Table 1-4
Products and Processes Covered in Raw Waste Load Sampling
Subcategory A (Continuous Non-Aqueous Processes)
Product
Cyclohexane
Ethyl Benzene
Vinyl Chloride
BTX Aromatics
k Products
Process
Hydrogenation of Benzene
Alkylation of Benzene with Ethylene
Acetylene and HC1
Co-Product of Ethylene Mfg.
Fractional Distillation
5 Manufacturing Processes
Phase I
Survey Vib'ts
1
1
1
1
1
6 Visits
19
-------
Table 1-4
Products and Processes Covered in Raw Waste Load Sampling
Subcategory B (Continuous Vapor Phase Processes)
WHERE WATER IS USED AS DILUENT OR ABSORBENT)
Product
Ethylene/Propylene
Butadiene
Methanol
Acetone
Acetaldehyde
Acetylene
Ethylene Oxide
FormaIdehyde
Ethylene Dichloride
Vinyl Chloride
Styrene
12 Products
Process
Pyrolysis of Hydrocarbons
Co-Product of Ethylene Mfg.
Dehydrogenation of N-Butane
Steam Reforming of Natural Gas
Dehydrogenation of Isopropanol
Oxidative Dehydration of Ethano'
Partial Oxidation of Methane
Catalytic Oxidation of Ethylene
Oxidation of Methanol
Direct Chlorination of Ethylene
Cracking of Ethylene Dichioride.
Dehydrogenation of Ethylbenzene
12 Manufacturing Processes
Phase I
Survey Visits
2
2
2
2
2
1
2
1
1
1
2
25 Visits
20
-------
Table 1-4
Products and Processes Covered in Raw Waste Load Sampling
Subcategory C (Liquid Phase Reaction Systems)
Product
Phenol
Phenol/Acetone
Oxo-Chemicals
Acetaldehyde
Acetic Acid
Methyl Methacrylate
Ethylene Glycol
Acrylic Acid
Acrylates
Terephthalic Acid
Dimethyl Terephthalate
Para-Cresol
Ani1ine
Bisphenol-A
Vinyl Acetate
Caprolactam
Long-Chain Alcohols
Tetraethyl Lead
Coal-Tar Products
20 Products
Process
Chlorobenzene Process
Cumene Oxidation and Cleavage
Carbonylation and Condensation
Oxidation of Ethylene (Wacker Process)
Oxidation of Acetaldehyde
Acetone Cyanohydrin Process
Hydration of Ethylene Oxide
Carbon Monoxide Synthesis with Acetylene
Esterification of Acrylic Acid
Nitric Acid Oxidation of Para-Xylene
Catalytic Oxidation of Para-Xylene
Esterification of TPA
Sulfonation of Toluene
Hydrogenation of Nitrobenzene
Condensation of Phenol and Acetone
Synthesis with Ethylene and Acetic Acid
Oxidation of Cyclohexane
Ethylene Polymerization
Addition of Ethyl Chloride to Lead Amalgam
Coal Tar Disti1lation
20 Manufacturing Processes
CATEGORY D (BATCH PROCESSES)
Product
Dyes/Pigments
Process
Phase I
Survey Visits
1
2
1
2
2
1
1
1
1
1
It
5
1
1
1
1
2
1
1
1
31 Visits
Phase I
Survey Visits
Batch Mfg.
21
-------
Table 1-5
Major RWL's of Pollutants Based on
Process Wastewater
Category
Cone. Range (mg/L)
B
Cone. Range (mg/L)
Cone. Range (mg/L)
Cone. Range (mg/L)
Flow RWL
BODs RWL
COD RWL
TOC RW
gals./1 ,000 Ibs
0.25 -
50 -
30 -
10,000 -
2,000
3,000
3,000
100,000
lbs/1 ,000 Ibs
0.1 -
(4oo -
0.09 -
(50 -
1.3 -
(3,000 -
52 -
(100 -
0.13
1 ,000)
7.0
500)
125
10,000)
220
3,000)
lbs/1 ,000 Ibs
0.3
(200
0.47
(200
1.9
(10,000
180
(1 ,000
- 3.7
- 10,000)
- 21.5
- 5,000)
- 385
- 50,000)
- k, 800
- 10,000)
lbs/1 ,000
0.03^
(50
0.2
(100
1.5
(3,000
60
(200
- 0.!
- 2,1
- 4o
- 2,1
- 15C
- 15,
- 1,6
- 2,0
-------
SUBCATEGORY A
FIGURE I—1
NON-AQUEOUS PROCESSES
MINIMAL CONTACT BETWEEN WATER AND REACTANTS OR PRODUCTS WITHIN THE PROCESS. WATER IS
NOT REQUIRED AS A REACTANT OR DILUENT AND IS NOT FORMED AS A REACTION PRODUCT. THE
ONLY WATER USAGE STEMS FROM PERIODIC WASHES OF WORKING FLUIDS OR CATALYST HYDRATION.
HEATING AND COOLING ARE DONE INDIRECTLY OR THROUGH NON-AQUEOUS ( HYDROCARBON ) WORKING
FLUIDS. PROCESS RAW WASTE LOADS SHOULD APPROACH ZERO WITH ONLY VARIATIONS CAUSED BY
SPILLS OR PROCESS UPSETS.
CYCLOHEXANE
H GAS RECYCLE
T. ENDS
BENZENE/HYDROGEN
^•CYCLOHEXANE
-------
FIGURE 1—2
SUBCATEGORY B PROCESS WATER CONTACT AS STEAM DILUENT AND/OR ABSORBENT
PROCESS WATER "USAGE IS IN THE FORM OF DILUTION STEAM, A DIRECT CONTACT QUENCH, OR AS
AN ABSORBENT FOR REACTOR EFFLUENT GASES. REACTIONS ARE ALL VAPOR PHASE AND CARRIED OUT
OVER SOLID CATALYSTS. MOST PROCESSES HAVE WATER ABSORBER COUPLED WITH STEAM STRIPPING
OF CHEMICALS FOR PURIFICATION AND RECYCLE. STEAM IS ALSO USED FOR DE-COKING CATALYST.
APPEARS FEASIBLE TO REDUCE PROCESS RAW WASTE LOADS TO NEAR ZERO THROUGH INCREASED
RECYCLE AND/OR REUSE OF CONTACT WATER.
ACETONE
ISOPROPANOL
OFF GAS
RECYCLE
REACTOR
91 % ISOPROPANOL
HASTEWATER (3)
-------
FIGURE 1—3
AQUEOUS LIQUID PHASE REACTION SYSTEMS
SUBCATEGORY C
LIQUID PHASE REACTIONS WHERE CATALYST IS IN AQUEOUS MEDIA SUCH AS DISSOLVED OR EMULSIFIED MINERAL SALT,
ACID/CAUSTIC SOLUTION. CONTINUOUS REGENERATION OF CATALYST SYSTEM REQUIRES EXTENSIVE WATER USAGE.
SUBSTANTIAL REMOVAL OF SPENT INORGANIC SALT BY-PRODUCTS MAY ALSO BE REQUIRED. WORKING AQUEOUS CATALYST
SOLUTION IS NORMALLY CORROSIVE. ADDITIONAL WATER REQUIRED IN FINAL PURIFICATION OR NEUTRALIZATION OF
PRODUCTS. REQUIREMENTS FOR PURGING LIMITING WASTE MATERIALS FROM SYSTEM MAY PREVENT PROCESS RAW WASTE
LOAD FROM APPROACHING ZERO.
OR
bo
tn
PHENOL
ACETONE
'ACETONE
WATER/NaCOj
METHYL STYRENE
PHENOL £ WATER
HATER (4)
ACETOPHENONE
WASTEWATER (3)
WASTEWATER (1 )
-------
FIGURE 1—4
SUBCATEGORY D
SEMI-CONTINUOUS AND BATCH PROCESSES
PROCESSES ARE CARRIED OUT IN REACTION KETTLES EQUIPPED WITH AGITATORS,SCRAPERS, REFLUX CONDENSERS, ETC.
DEPENDING ON THE NATURE OF THE OPERATION. MANY REACTIONS ARE LIQUID PHASE WITH AQUEOUS CATALYST SYSTEMS
REACTANTS AND PRODUCTS ARE TRANSFERRED FROM ONE PIECE OF EQUIPMENT TO ANOTHER BY GRAVITY FLOW, PUMPING
OR PRESSURIZATION WITH AIR OR INERT GAS. MUCH OF THE MATERIAL HANDLING IS MANUAL WITH LIMITED USE OF
AUTOMATIC PROCESS CONTROL. FILTER PRESSES USED TO SEPARATE SOLID PRODUCTS FROM LIQUID. WHERE DRYING IS
REQUIRED, AIR OR VACUUM OVENS ARE USED. CLEANING OF NON-CONTINUOUS PRODUCTION EQUIPMENT CONSTITUTES
MAJOR SOURCE OF WASTEWATER. ANTICIPATED WASTE LOADS FROM PRODUCT SEPARATION AND PURIFICATION WILL BE AT
LEAST TEN TIMES THOSE FROM CONTINUOUS PROCESSES.
DYE MANUFACTURE
RAW MATERIAL
BATCH PROCESSES
(DYE
FILTRATION
(FILTER PRESS)
COOLING WATER
& PROCESS WATER
DRYING
(DRUM DRYERS
TRAY OVENS)
BLENDING
'PRODUCT
lr FILTRATE
COPPER TREATMENT
& FILTRATION
:r+
EQUALIZATION
A > CITY SEWER
BLEACH
-------
SECTION II
RECOMMENDATIONS
Effluent limitations communsurate with the best practicable
control technology currently available are presented for each
industrial subcategory group of the organic chemicals
manufacturing industry. Major productTprocess segments which
are applicable to these limitations are listed in Table II-1.
Effluent limitations are presented in Table II-2 for the 1977
standard (BPCTCA). It should be noted that process waste waters
subject to these limitations include all process water exclusive
of auxilary sources such as boiler and cooling water blowdown,
water treatment back wash, laboratories and other similar
sources.
End-of-process technology for BPCTCA involves the application of
biological treatment systems as typified by activated sludge,
trickling filters, aerated lagoons and anaerobic lagoons.
Equalization with pH control and oil separation is provided in
order to smooth out raw waste variations. Chemical flocculation
aids, when necessary, are added to the clarification system in
order to control suspended solids.
In-process controls as previously described in Section I are
provided to remove those pollutants which interfere with
biological waste treatment systems. Biological waste treatment
does not preclude the use of equivalent chemicalphysical systems.
It may be advantageous to provide such systems within the process
or at the end of process, especially where land availability is a
limiting factor.
Effluent limitations to be attained by the application of the
best available technology economically achievable are presented
in Table II-3 for the major product-process segments listed in
Table II-l for each subcategory group. End-of-process treatment
for BATEA include the addition of activated carbon systems to
biological waste treatment processes. Exemplary in-process
controls, as discussed in the previous section of this document,
are also applicable to this technology. It is emphasized that
the model treatment system does not preclude the use of activated
carbon within the plant. Such systems are frequently employed
for recovery of products, by-products, and catalysts.
The best available demonstrated control technology for new
sources includes the most exemplary process controls, as
previously enumerated, with biological waste treatment and
filtration for removal of suspended solids. Effluent limitations
for the major product-process segments are presented in Table II-
4.
27
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Table II-l
Subcateggries_Qf_the_Organic__ Chemicals Manufacturing
(Ph§.se_i_-_M3Jor_Product-Processes]_
Products
BTX Aromatics
BTX Aromatics
Cyclchexane
Vinyl Chloride
Rl^Prcducts
Acetone
Butadiene
Ethyl benzene
Ethylene and Propylene
Ethylene dichloride
Ethylene oxide
Formaldehyde
Methanol
Methyl amines
Vinyl acetate
Vinyl chloride
B2_Products
Acetaldehyde
Acetylene
Butadiene
Butadiene
Styrene
Hydrotreatment of pyrolysis gasoline
Solvent extraction from reformate
Hydrogenatiori ot benzene
Addition of hydrochloric acid
to acetylene
Proces^_with_Proces§_Water_Contact
a s_Steam_ni;l.li§Iit_or_ Absorbent
Dehydrogenation of isopropanol
Co-product of ethylene
Alkylation ot benzene with
ethylene
Pyrolysis of naphtha or liquid
petroleum gas
Direct chlorination of ethylene
Catalytic oxidation of ethylene
Oxidation ot methanol
Steam reforming of natural gas
Addition ot ammonia to methane
Synthesis of ethylene and acetic acid
Cracking of ethylene ddchloride
R2_Process_Descrip.ti.ons
Dehydrogenation of ethanol
Partial oxidation ot methane
Dehydrogenation of n-butane
Oxidative - denyarogenation
of n-butane
Dehydrogenation or ethylbenzene
-------
Cl_Prgducts
Acetic acid
Acrylic acid
Coal tar
Ethylene glycol
Terephthalic acid
Terephthalic acid
C2_Prgducts
Acetaldehyde
Caprolactam
Coal Tar
Oxo Chemicals
Phenol and Acetone
C3 Products
Acetaldehyde
Aniline
Bisphenol A
Dimethyl terephthalate
CU_Product§
Acrylates
p-cresol
Methyl methacrylate
Terephthalic acid
Tetraethyl lead
Cl_Process Descriptions
Oxidation of acetaldehyde
Synthesis with carbon monoxide
and acetylene
Distillation of coal tar
Hydrogenation of ethylene oxide
Catalytic oxidation of p-xylene
Purification of crude terephthalic acid
C2_Process_De scrijot ions
Oxidation of ethlene with oxygen
Oxidation of cyclohexane
Pitch forming
Carbonylation and condensation
Cumene oxidation and cleavage
Oxidation of ethylene with air
Nitration and hydrogenation of benzene
Condensation of phenol and acetone
Esterif ication of terephthalic acid
Esterif icaticn of acrylic acid
Sulfunation of toluene
Acetone cyanohydrin process
Nitric acid process
Addition of ethyl chloride to
lead arnalgum
29
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Table II- 2
Effluent Limitations for the Best Practicable Control Technology
Currently Available (BPCTCA) Organic Chemicals Manufacturing
Industry (Phase I- Major Product-Process by Subcategory)
Effluent Characteristics
Effluent Limitations
kg/kkg production
Subcategorv A
BOD 5
TSS~
0.045
0.067
.__
period^ofrthirty
consecutj ye days
0.02
0.03
Subcategprv B
Bl ^Product-Processes
BOD5
TSS
B2± Product; Processes
BOC5
TSS~
Subcategory C
Cl^Prcduct-Processes
BOD 5
1SS
0.13
0.20
0.95
1.42
0.28
O.U2
0.058
0.088
0.42
0.64
0.12
C.19
-Processes
BOD 5
TSS
Phenols(Cumene process only)
C3 Product-Processes
BOD 5
TSS
Phenols(Bisphenol A process only)
C4 Product-Processes
BOD 5
TSS~
Phenols(p-cresol process only)
0.55
0.56
O.OU5
1.15
0.15
0.045
3.08
2.80
0.045
0.25
0.25
0.02
0.51
0.068
0.02
1.37
1.25
0.020
pH for all Subcategories between 6.0 - 9.0
30
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Table 11-3
Effluent Limitations for the Best Available Technology
Economically Achievable (BATEA) - Organic Chemicals Manufacturing
Industry (Phase I- Major Product-Process by Sufccategory)
Effluent characteristics
kg/kkg production
Maximum_for 51§£i2Lyni_A..y.eracje_of
consecutive days
COD 0.062
BODS 0.015
TSS~ 0.022
Sutcatecjor2_B_
Bl_Prcduct-Processeg
COD 0.80
BOD5 0.044
TSS~ 0.066
B2_Product-Prgcessgs
COD 1.32
BOD5 0.32
TSS~ 0.48
Subcateqory c
Cl_Product-Processes
COD 0.52
BOD5 0.093
TSS~ 0.14
C2 Product-Processes
COD 1.75
BOC5 0.12
TSS 0.19
Phenols(Cumene process only) 0.003
Cj^Product-Prgcesses
COD 6.07
BOD5 0.067
TSS~ 0.05
Phencls(Bisphenol process only) 0.003
C4 Product-Processes
0.045
0.0085
0,013
0.58
0.025
O.OU
0.95
0.18
0.29
0. 37
0.053
0.085
0.98
0.068
0.11
0.0017
4. 37
0.043
0.031
0.0017
COD 39.25
BOD5 0.62
TSS~ 0.94
Phenols (p-cresol process only) 0.003
28.26
0.35
0.57
0.0017
pH for all Subcategories between 6.0 - 9.0
31
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Table II-4
Standards of Performance for New Organic Chemicals
Manufacturing Sources
(Phase I - Major Product-Processes by Subcategory)
Effluent characteristics
Subcategory A
BOBS
TSS~
Subcategory R
Bl Product-Processes
BOD5
TSS
B2^Prgduct^Processes
BOC5
TSS~
-
kg/kkg production
Maximum_for
any one day
0.037
0.034
0.11
0.10
0.76
0.72
Maximum Average of
daily _yalues_.for_an.y.
£eriod_of_thirty
consecutive Delays
0.017
0.015
O.OU8
0.044
0. 34
0.32
Ci^Prcduct- Processes
BOD 5
TSS~
0.23
0.21
C2 Product^Processes
BOC5 0.45
TSS~ 0.28
Phenols (Cuirene process only) 0.045
C3mProduct-Processes
BOC5 0.9U
TSS~ 0.076
Phenols (Eisphenol process only) O.OU5
CU Product-Processes
BOC5 2.56
TSS~ 1-^0
Phencls(p-cresol process only) 0.0U5
0.10
0.094
0.20
0.12
0.02
0.42
0.034
O.G2
1.14
0.63
0.02
pH for all Subcategories between 6.0 - 9.0
32
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SECTION III
INTRODUCTION
Purpose and Authority
Section 301(b) of the Act requires the achievement, by not later
than July 1, 1977, of effluent limitations for point sources,
other than publicly-owned treatment works, which are based on the
application of the best practicable control technology currently
available as defined by the Administrator pursuant to Section
304 (b) of the Act. Section 301(b) also requires the achievement,
by not later than July 1, 1983, of effluent limitations for point
sources, other than publicly-owned treatment works, which are
based on the application of the best available technology eco-
nomically achievable which will result in reasonable further
progress toward the national goal of eliminating the discharge of
all pollutants, as determined in accordance with regulations
issued by the Administrator pursuant to Section 304 (b) to the
Act. Section 306 of the Act requires the achievement, by new
sources, of a Federal standard of performance providing for the
control of the discharge of pollutants which reflects the
greatest degree of effluent reduction which the Administrator
determines to be achievable through the application of the best
available demonstrated control technology, processes, operating
methods, or other alternatives, including, where practicable, a
standard permitting no discharge of pollutants.
Section 304(b) of the Act requires the Administrator to publish,
within one year of enactment of the Act, regulations providing
guidelines for effluent limitations setting forth the degree of
effluent reduction attainable through the application of the best
practicable control technology currently available and the degree
of effluent reduction attainable including treatment techniques,
process and procedure innovations, operation methods, and other
alternatives. The regulations proposed herein set forth effluent
limitation guidelines pursuant to Section 304(b) of the Act for
the organic chemicals industry.
Section 306 of the Act requires the Administrator, within one
year after a category of sources is included in a list published
pursuant to Section 306 (b) (1) (A) of the Act, to propose
regulations establishing Federal standards of performances for
new sources within such categories. Section 307(c) of the Act
also requires the Administrator to propose pretreatment standards
for new sources discharge to publicly owned waste treatment
plants. The Administrator published, in the Federal Register of
January 16, 1973 (38 F.R. 1624), a list of 27 source categories.
Publication of the list constituted announcement of the
Administrator's intention of establishing, under Section 306,
standards of performance applicable to new sources within the
organic chemicals industry, which was included in the list
published January 16, 1973. This document is published under
authority of section 304 (c) of the Act which requires that
33
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information be made available in the form of a technical report
on alternate treatment methods to implement effluent limitations
and standards of performance for new sources.
Methods Used for Development of the Effluent Limitations and
Standards of Performance
The effluent limitations guidelines and standards of performance
proposed herein were developed in the following manner. The
point-source category was first subcategorized for the purpose of
determining whether separate limitations and standards are
appropriate for different segments within a point-source
category. Such subcategorization was based upon raw material
used, product produced, manufacturing process employed, and other
factors. The raw waste characteristics for each subcategory were
then identified. This included an analysis of: 1) the source
and volume of water used in the process employed and the sources
of waste and waste waters in the plant; and 2) the constituents
(including thermal) of all waste waters (including toxic
constituents and other constituents) which result in taste, odor,
and color in water or aquatic organisms. The constituents of
waste waters which should be subject to effluent limitations
guidelines and standards of performance were identified.
The full range of control and treatment technologies existing
within each subcategory was identified. This included an
identification of each distinct control and treatment technology,
including both in plant and end -of-pipe technologies, which are
existent or capable of being designed for each subcategory. It
also included an identification of the effluent level resulting
from the application of each of the treatment and control
technologies, in terms of the amount of constituents (including
thermal) and of the chemical, physical, and biological
characteristics of pollutants. The problems, limitations, and
reliability of each treatment and control technology and the
required implementation time were also identified. In addition,
the nonwater quality environmental impact (such as the effects of
the application of such technologies upon other pollution
problems, including air, solid waste, noise, and radiation) was
also identified. The energy requirments of each of the control
and treatment technologies were identified, as well as the cost
of the application of such technologies.
The information, as outlined above, was then evaluated in order
to determine what levels of technology constituted the "best
practicable control technology currently available", "best
available technology economically achievable", and the "best
available demonstrated control technology, processes, operating
methods, or other alternatives". In identifying such
technologies, various factors were considered. These included
the total cost of application of technology in relation to the
effluent reduction benefits to be achieved from such application,
the age of equipment and facilities involved, the process
employed, the engineering aspects of the application of various
types of control techniques, process changes, nonwater quality
34
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environmental impact (including energy requirements), and other
factors.
During the initial phases of the study, an assessment was made of
the availability, adequacy, and usefulness of all existing data
sources. Data on the identity and performance of waste water
treatment systems were known to £»e included in:
1. Letter surveys conducted by the Manufacturing Chemists
Association (MCA) .
2. Corps of Engineers Permit Applications. .
3. Self-reporting discharge data from various states.
Limited data on process raw waste loads were also known to be
included in previous MCA survey returns.
A preliminary analysis of these data indicated an obvious need
for additional information.
Refuse Act Permit Applications data are limited to identification
of the treatment system used and reporting of final
concentrations (which were diluted with cooling waters in many
cases); consequently, operating performance could not be
determined.
Texas, where there is a high concentration of organic chemical
plants, has a self-reporting discharge system. These reports
again show only final effluent concentrations and identify the
system used; only rarely is there production information
available which would permit the essential determination of unit
waste loads.
Additional data in the following areas were therefore required:
1) process RWL (Raw Waste Load) related to production; 2)
currently practiced or potential in-process waste control
techniques; and 3) the identity and effectiveness of end-of-pipe
treatment systems. The best source of information was the
chemical manufacturers themselves. New information was obtained
from direct interviews and sampling visits to organic chemical
producing facilities. This additional data was obtained from
direct interviews and from inspection and sampling of organic
chemical manufacturing and waste water treatment facilities.
Collection of the data necessary for development of RWL and
effluent treatment requirements within dependable confidence
limits required analysis of both production and treatment
operations. In a few cases, the plant visits were planned so
that the production operations of a single plant could be studied
in association with an end-of-process treatment system which
receives only the wastes from that production. The RWL for this
plant and associated treatment technology would fall within a
single category. However, the unique feedstock and product posi-
35
-------
tion applicable to individual manufacturers made this idealized
situation rare.
In the majority of cases, it was necessary to visit individual
facilities where the products manufactured fell into several
subcategories. The end-of-process treatment facilities received
combined waste waters associated with several subcategories
(several products). It was necessary to analyze separately the
production (waste generating) facilities and the effluent (waste
treatment) facilities. This required establishment of a common
basis, the Raw Waste Load (RWL), for common levels of treatment
technology for the products within a subcategory and for the
translation of treatment technology between categories.
The selection of process plants as candidates to be visited was
guided by the trial subcategorization, which was based on
anticipated differences in RWL. Process plants which manufacture
only products within one subcategory, as well as those which
cover several sutcategories, were scheduled, to insure the
development of a dependable data base.
The selection of treatment plants was developed from identifying
information available in the MCA survey returns. Corps of
Engineers Permit Applications, state self-reporting discharge
data, and contacts within the industry. Every effort was made to
choose facilities where meaningful information on both treatment
facilities and manufacturing processes could be obtained.
Survey teams composed of project engineers and scientists
conducted actual plant visits. Information on the identity and
performance of wastewater treatment systems were obtained
through:
1. Interviews with plant water pollution control personnel.
2. Examination of treatment plant design and historical
operating data (flow rates and analyses of influent and
effluent).
3. Treatment plant influent and effluent sampling.
The data base obtained in this manner was then utilized by the
methodology previously described to develop recommended effluent
limitations and standards of performance for the organic chemical
industry. All of the references utilized are included in Section
XV of this report. The data obtained during the field data
collection program are included in Supplement B.
Description of the Organic Chemicals Industry
General Considerations
Synthetic organic chemicals are derivative products of naturally-
occurring raw materials (petroleum, natural gas, and coal) which
36
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have undergone at least one chemical conversion. The organic
chemicals industry was initially dependent upon coal as its sole
source of raw materials. However, during the last two decades it
has moved rapidly from coal to petroleum based feedstocks.
Although the cost of coal is less than half that of most liquid
fuels, the handling and processing of liquids is much cheaper.
In addition, the extraction of coal is much more labor-intensive
than is the extraction of liquid fuels.
In recognition of the change in origin of raw materials, the term
"petrochemical" has come into common usage. Although a precise
definition of "petrochemicals" has yet to gain universal
acceptance, it commonly refers to all organic chemical products
derived from petroleum fractions and by-products or from natural
gas constituents.
From its modest beginnings in the 1920's with the manufacture of
isopropanol from refinery off-gas propylene, petrochemistry has
by now not only made possible the almost total elimination of
coal and coal-tar as sources of chemical raw materials, but has
also gone a long way towards replacing such methods of obtaining
organic chemicals as fermentation, extraction of compounds from
materials occurring in nature, and chemical transformation of
vegetable fats and oils.
Until the late 1930*s, petrochemistry was limited in its scope to
the synthesis of oxygenated solvents, most of them previously
obtained by fermentation. World War II ushered in the age of
synthetic polymeric substitutes for natural and inorganic
material: metals, leather, wood, glass, rubber, waxes, gums,
fibers, glues, drying oils, etc. The production of these
materials on a large scale sufficient to satisfy their enormous
potential markets required raw materials far in excess of those
available from refinery off-gas. Therefore, additional olefins
began to be produced by cracking light saturated hydrocarbons
present in the offgas, and later by resorting to similar
materials recovered from natural gas.
A parallel phenomenon was the extremely rapid growth in the need
for ammonia and nitrogen fertilizers all over the world. Whereas
synthesis gas was originally obtained primarily from coal and by
upgrading coke oven gases, the surge in ammonia requirements made
it necessary to tap other sources of raw materials. In the
regions of the world where natural gas was found, this alternate
source of synthesis gas became the stream-reforming of methane.
So far, petrochemistry had become exlusively a source of
aliphatic chemicals. The next step was the development of
processes for extracting aromatic hydrocarbons from catalytic
reformate. This was to be followed by methods for correcting the
imbalance between toluene and benzene in reformed naphtha by
dealkylating the former and producing additional benzene. With
these developments, the elimination of coal as a necessary base
for the synthetic organic chemical industry was practically
completed.
37
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The most economical techniques for producing olefins and
synthesis gas are, respectively, cracking in a tubular furnace
and steam reforming. For purely technical reasons, these methods
were restricted at first to materials no heavier than butane. A
natural advantage was conferred on those regions of the world
where natural gas was found, or those where liquid fuels had
acquired such a large share of the total demand for energy that
enough by-products were available for the chemical industry.
In the early 1960's, one of the most important stages in the
evolution of petrochemistry was reached. It became possible to
apply the techniques of steam reforming and tubular furnace
cracking to liquid feedstocks, thereby freeing the industry from
the requirement of locating in the vicinity of petroleum
refineries or in regions rich in natural gas. This stage was
that of "chemical refinery" a chemical complex feeding on liquid
feedstocks that are totally converted to petrochemical raw mate-
rials.
A further trend within the chemical industry has been the
extraordinary simplification of numerous organic syntheses made
possible during the last ten years. This is due particularly to
developments in catalysis and automatic control. Oxygenated,
unsaturated, and nitrogenated compounds, formerly obtained via
routes involving several steps, are gradually being produced by
direct oxidation, nitration, amination, or dehydrogenation.
Petrochemicals generally tend to be made from hydrocarbon raw
materials having the same number of carbon atoms as the finished
product. This, combined with the construction of ever larger
production units, has been the cause of the drop in the price of
organic chemicals to an extent that would have seemed unthinkable
a few years ago.
However, these trends are counterbalanced by a crisis which is
rapidly developing for the organic chemical industry: i.e.
concer- ing the availability of economical new materials. After
having become accustomed to relatively cheap energy and plant
feedstocks, chemical makers must now pay more for these materials
as other demands crowd in on their traditional sources.
The alternate use for natural gas is as fuel. In the past, this
alternate value as fuel set a base price of about 0.40/lb on
chemical feedstocks such as ethane and propane. With chemical
producers willing to pay 0.70/lb for these feedstocks, the
natural gas industry found it advantageous to sell them for
chemical usage. However, recent drastic increases in demand for
natural gas as a pollution-free fuel, coupled with a leveling off
of gross gas production, have more than tripled the base fuel
value for ethane and propane as chemical feedstocks. This has
led most chemical producers to plan future production of
chemicals such as ethylene on processes that use heavier
feedstocks such as liquid crude oil distillates.
Light liquid distillates, however, have an alternate use and
value as gasoline. A typical barrel of crude oil usually
38
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contains only about 20 percent light distillates in a boiling
range suitable for use as gasoline. All of this must be
processed at some expense, and, in order to satisfy the
automobile-oriented society in the United States, another 25
percent of the higher boiling crude oil distillates must be
converted into the gasoline boiling range by cracking and other
refinery processing.
With crude oil valued at 7.52/gal ($3.15/bbl), the final gasoline
product, representing U5 percent of the barrel, must be valued at
close to 12
-------
reactive precursors, and possible intermediates or finished
products manufactured by chemical conversion.
The lower members of the paraffin and olefin series of organic
raw materials are the basic starting point in the manufacture of
a large number of important organic chemicals. Diagrams which
depict the many possible derivatives obtained through chemical
conversion are presented for:
Methane (Figure III-1)
Ethylene (Figure III-2)
Propylene, n-butylenes, and iso-butylene (Figure III-3)
BTX aromatics (Figure III-4) .
These representations are called "end-use diagrams" and serve to
illustrate the many complex interactions which are possible
between raw materials, precursors, intermediates, and final
products.
The precise definition of a specific manufacturer's production
activities within this matrix poses a difficult problem.
Traditionally, the industry has been studied according to
chemical function. There are cases of firms specializing in the
production of compounds having a common chemical function or that
are made by a given unit process. For example, some companies
produce several nitration derivatives, or fatty amines, or
isocyanates. These cases are often the result of a favorable raw
material positon enjoyed by specific companies.
More important from the standpoint of the actual behavior of
chemical companies is horizontal integration. This can be a
powerful motivation due either to a desire to provide hedges
against changes in market structures (as in the case of firms
that produce various types of polymers or synthetic fibers) or to
complement a line of products (e.g. when a company making polyols
decides also to produce isocyanates) .
Despite the significance of these types of motivation in the
chemical industry, however, the main influence in recent years
has been the need to integrate vertically. Firms that until
recently were content to produce intermediates or end-products
have been under constant pressure either to integrate backwards
by acquiring their own sources of raw materials, or to integrate
forward by gaining control of their clients. The percentage of
captive utilization of most major chemical intermediates is
growing steadily. This is attributable chiefly to the
circumstance that unit profits generally are higher at the
finished-product end of the chain. Consequently, many large oil
and chemical companies have rapidly enlarged the scope of their
activities (both by acquisition and by internal expansion), and
have gradually increased their position in the market vis-a-vis
those companies which have been content to maintain their
original structure.
40
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Table IIl-l
Raw Materials, Precursors, Intermediates, and Finished Products
Frequently Found in The Organic Chemicals Industry
Precursors
Raw Materials
By Disti 1 lation
Paraffins and
cycl ics
Natural gas
Hydrogen
Methane
Refinery gases
Ethane*
Propane*
n-Butane*
(Basic Chemicals)
By Conversion
Olefins, diolefins,
acetylene, aromatics
Acetylene
1 sobutene
Ethy lene
Propy lene
n-Butanes
1 ntermediates
By Conversion
Various inorganics
and organics
Synthesis gas
Acetic acid
Acetic anhydride
1 soprene
Ethylene oxide, etc.
Butadiene
Finished Products
By Conversion
Inorganics and
organics
Carbon black
NH-
Methanol
Formaldehyde
Acetates
Fibers
Rubber
Rubber and fiber
Rubber
Hexane
Heptanes
Refinery naphthas
Naphthenes
Benzene
Toluene
Xylenes
Cyclopentadiene
Toluene
o-m-p-xylene
Adi pic acid
Ethylbenzene
Styrene
Cumene
Alky1 benzene
Cyclohexane
Phenol
Benzoic acid
Phthalic anhydride
Phthalic anhydride
Fibers
Styrene
Rubber
Phenol, acetone
Plastics
Plastics
Plastics
Methyl naphthanes Naphthalene
-'"From LPG and refinery cracked gas.
Note: Aromatics are also obtained by chemical conversions (demethylation, etc.).
41
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FIGURE Ill-l
PETROCHEMICALS FROM METHANE
1
1
(MAJOR SOURCE)
NITR
PYROLYSIS (MINOR SOURCE)
/ \STEAM OR HYDROGEN STEAM HYDROGEN
nAINt /OXYGEN MONOXIDL— , DIOXIDE
/ T ^.
^^ AIR |. HvnnnFM rYANIRF
ACETYLENE ^ ^F*
| AlKT LUN ! 1 K 1 LL
\
DIMER
A 1 R
1^
' '
HYDROGEN AMMON UM
1 TR ATE
—(MAJOR
SOURCE)
— — — ^ ' ^ 'UREA
CARBON
D OX ^E
AIR
HYDROGEN CHLORIDE
, , -\
METHYL CHLOR DE
HYDROGEN HYDROGEN CHLORIDE CHLORINE „_+
CHLOR DE OR ACETIC ACID ALMLI
V 1 ' ^ ' ^
CHLOROPRENE v ! JJL^ ^JR^DE CHLOROETHYL ENES ~^
CHLORINE ^"*
METHYLENE DICHLORIDE
CHLOROMFTinwr1;
CHLOROFORM
CARBON TETRACHLORIDE
s
-------
FIGURE 111-2
PETROCHEMICALS FROM ETHYLENE
REFINERY-
CRACKED
GAS
(CATALYST)
POLYETHYLENE
OXYGEN (CATALYST)
HYPO-
CHLOROUS
ACID
CHLORINE
ETHYLENE
CHLOROHYDRIN
ALKALI
ETHYLENE
DICHLORIDE
BROMINE
HYDROGEN
CHLORIDE
ETHYLENE
D1BROMIDE
ETHYL CLORIDE
WATER
(CATALYST)
SULFURIC ACID
SULFURIC ESTERS
WATER
BENZENE
ETHYLBENZENE
ETHANOLAMINES
AMMONIA
ETHYLENE OXIDE
-H
-*
HYDROGEN
CYANIDE
WATER
DEHYDRO-
GENATION
ACRYLONITRILE
VINYL CHLORIDE
ETHYL ALCOHOL
STYRENE
POLYGLYCOLS
ETHYLENE GLYCOL
OI-AND TRIETHYLENE
GLYCOLS
ALCOHOLS OR
ALKYL PHENOLS
GLYCOL ETHERS AND
POLYGIYCOL ETHERS
ACETALDEHYDE
-------
FIGURE 111-3
PETROCHEMICALS FROM PROPYLENE AND BUTYLENES
( CATALYST)
SULFURIC ACID OR SULFUR DIOXIDE
OXIDATION OR OEHYDROGENATI OH
CUMENE HYOROPEROXIDE
CARBON HONOXIOE,
ALDEHYDES CONTAINING
8 CARBON ATOMS
ACID »| HEPTEHES
ISOOCTYL ALCOHOL
») SEC-BUTYL ALCOHOL[
METHYL ETHYL KETONE
(SULFURIC
n-BUTYLENES I ACID)
DEHYDROGENATION
POLYMERS (AND COPOLYMERS WITH
STYRENE AND ACRYLONITRILE)
OEHYDRO- 'I BUTADIENE
GENATION JCHLORINE
SODIUM CYANIDE, HYDROGEN
ADIPONITRILE, THEN
HEXANETHLENEDIANINE
»|t-BUTYl ALCOHOL [
\ (SULFURIC ACID)
ISOBUTYLENE
COPOLYMER WITH 2',
ISOPRENE ( BUTYL RUBBER)
»| DI-AND TRIISOBUTYLENE I
BORON TRIFLUORIDE (LOW TEMPERATURE)
-------
FIGURE 111-4
CYCLIC PETROCHEMICALS
tn
REFORMING OF CYCLOPENTANES,
CYCLOHEXONES, AND PARAFFINS
BENZENE
TOLUENE
XYLENES
ETHYL-
ENZENE
TOLUENE | N|TRIC >CIIV[HITROT01.UENE$ [
PROPYLENE
TETRAMER
-------
The specific set of feedstocks, intermediates, and products which
are associated with the operation of any facility represents the
sum of these considerations as they relate to an individual
company. For this reason there is no effective method by which
manufacturing operations may be correlated between any two
separate plants. Each plant's production and set of process
operations constitute a unique contribution toward the
profitability of the operation.
The true production associated with a given plant must include
the captive utilization of feedstocks and intermediates within
the plant's boundaries. Actual production would be the total of
all intermediate processing steps between the initial feedstock
(e.g. LPG or naphtha) and the final products. A typical sequence
of processing operations is illustrated below:
Raw Material: LPG (Ethane and Propane)
Process I: Steam Cracking
Intermediate: Ethylene
Process 2: Oxidation
Intermediate: Acetaldehyde
Process 3: Oxidation
Final Product: Acetic Acid
In this simplified example, the production at the facility would
represent the sum of the ethylene, acetaldehyde, and acetic acid
produced by Processes 1r 2, and 3 respectively.
In order to insure the smooth operation of the different segments
within a producing facility, manufacturers maintain inventories
of feedstocks, intermediate products, and final products
available for subsequent processing or for shipment from the
plant. Depending on the nature of the operation, these
inventories are updated on a monthly, weekly, or even daily
basis. The examination of historical production inventories and
associated manufacturing processes for a given facility provides
the most meaningful picture as to the nature of the activities
within its boundaries. This is directly related to the type and
quantity of wastes which are generated.
Scope of Work Related to Actual Industry
In order to establish boundaries on the scope of work for this
study, the organic chemicals industry was defined to include all
commodities listed under SIC 2815 (Cyclic Crudes and
Intermediates) and SIC 2818 (Industrial Organic Chemicals Not
Elsewhere Classified). A list of the specific products included
under these two SIC numbers was presented in Tables 1-1 and 1-2.
The study has been further limited by the exclusion of plastics,
fibers, agricultural chemicals, pesticides, fertilizers,
detergents, paints, and pharmaceuticals.
46
-------
The effluent, limitations presented in this report for many of
these chemicals should be applied only where their production is
not associated with refining operations such as crude topping,
cracking and reforming.
Because of the diverse nature of the organic chemicals industry,
there will always be gray areas where definitive boundaries
cannot be established. The Government's Standard Industrial
Classification system for classifying industrial enterprises by
their major lines of activity puts producers of chemicals,
plastics materials, and synthetics in industry group 281.
However, Table III-2, a tabulation of the fifty largest producers
of chemicals in the U.S. (compiled by the Chemigal and
SasiHSSiina News, April 30,1973), contains only twenty-one firms
from the 281~ group. The relative sizes of establishments by
numbers of employees are shown in Table III-3 The companies in
the list that are not members of the 281 group are classified in
industries ranging from meat and dairy products to photographic
and optical equipment. Nearly half of them are petroleum
refiners. When approaching a specific facility for the purpose
of applying effluent limitations, it is necessary to gain some
background information on the exact nature of its operations and
not to rely entirely on the SIC number under which the company
owning the facility is listed.
The data collection effort associated with this study has been
divided into two parts, Phase I and Phase II. The information
and effluent limitations presented in the report are based on
Phase I, where major emphasis was placed upon high production
volume commodities. The subsequent effort in Phase II will
concentrate on smaller-volume products.
Water Usage Associated with Different Segemnts of a Chemical
Plant
At first glance, an organic chemicals plant often appears to be a
chaotic maze of equipment, piping, and buildings that is totally
unlike any other facility, even those which manufacture the same
product. Nevertheless, there are certain basic components common
to almost all chemical planes: a process area; storage and
handling facilities for raw materials, intermediates, and
finished products; electrical, steam, air, and water systems with
associated sewers and effluent treatment facilities; and, in most
cases, a laboratory, an office, control rooms, and service roads.
The process area is normally referred to as the "battery limit",
while the remainder of the plant is called the "off-sites". The
off-sites can be broken down into their components: the storage
and handling facilities, the utilities, and the services. This
four-area concept in plant layout is illustrated by the plot plan
shown in Figure III-5.
The storage facilities associated with any chemical plant
obviously depend upon the physical state (i.e. solid, liquid, or
gas) of the feedstocks and products. Storage equipment
47
-------
Table I I I - 2
Fifty Largest Chemical Producers in the United States
1972
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
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Note
Rank
1971
1
2
4
3
5
6
7
8
9
10
12
11
14
13
15
16
19
20
17
18
21
23
29
22
25
26
27
32
28
30
31
34
33
36
41
44
41
40
35
43
47
48
46
38
49
50
37
39
: SIC cl
DuPont
Union Carbide
Dow Chemical
Monsanto
Celanese
Exxon
W.R. Grace
Allied Chemical
Occidental Petroleum
Hercules
Eastman Kodak
FMC
Shell Oil
American Cyanamid
Rohm and Haas
Stauffer Chemical
Phillips Petroleum
Borden
Mobil Oil
Ethyl Corp.
Cities Service
Gulf Oil
NL Industries
Standard Oil (Ind.)
PPG Industries
Diamond Shamrock
Akzona
B.F. Goodrich
Ashland Oil
U.S. Steel
Air Products
3M Co.
Olin
Standard Oil of California
BASF Wyandotte
Airco
Ciba-Geigy
Tenneco
El Paso Natural Gas
Goodyear Tire
Merck
Baychem
Chemetron
Pfizer
American Hoechst
Lubrizol
Reichhold Chemicals
Atlantic Richfield
Swift 6- Co.
Koppers
Chemica1
Sales
$ Millions
$3550
2185
2103
1924
1279
1258
1088
1001
831
795
694
657
645
644
588
543
490
475
470
458
424
420
415
410
405
404
391
363
352
350
342
330
329
304
301
283
280
277
254
250
235
230
224
222
220
217
217
216
210
204
Net
Sales
$ Millions
$ 4,366
3,261
2,404
2,225
1,385
20,310
2,315
1,501
2,721
932
3,478
1,498
4,076
1,359
619
543
2,512
2,193
9,166
632
1,862
6,243
1,014
4,503
1,396
617
572
1,507
1 ,780
5,429
351
2,114
1,098
5,829
301
402
625
3,275
1,097
4,072
958
230
314
1,093
260
217
217
3,321
3,241
613
Chemical
Sales as
Per Cent
of Total
Sales
81%
67
87
86
92
67
31
85
20
44
16
47
95
100
19
22
5
73
23
7
41
9
29
65
68
24
20
6
97
16
30
5
100
57
45
8
23
6
25
100
71
20
85
100
100
7
6
33
SIC
Class
281
281
281
281
281
291
281
281
509
281
383
281
291
281
281
281
291
202
291
281
291
291
285
291
321
281
281
301
291
331
281
383
281
291
281
291
492
301
283
281
283
289
281
291
201
281
SIC classifications are as follows: 201 Meat; 202 Dairy; 281 Basic chemicals; 283 Drugs; 285 Paints;
289 Other chemicals; 291 Petroleum; 301 Tires; 321 Glass; 331 Iron and steel; 383 Photo equipment;
492 Gas; 509 Miscellaneous wholesalers.
Source: Chemical and Engineering News, April 30, 1973
48
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10
TABLE III-3
ESTABLISHMENTS BY EMPLOYMENT SIZE
IN THE ORGANIC CHEMICALS
MANUFACTURING INDUSTRY
Establishments
By Size
(No. of Employees)
< 10
< 50
< 100
< 250
< 500
<1,000
<2,500
>2,500
Total
SIC 2815
46
97
113
150
163
170
177
0
SIC 2818
174
289
339
409
447
468
481
7
Total
Companies
Total Employment
(1,000)
Total Payroll
($Million)
177
115
30
251.1
488
339
95.1
844.9
No.
220
386
452
559
610
638
658
665
665
454
125.1
1,096.0
33
58
67
84
92
96
99
100
* 1967 US Census Data
-------
frequently utilized includes: cone-roof tanks, with or without
"floating" roofs, for storage of liquid hydrocarbons; cylindrical
or spherical gas-holding tanks; and concrete pads or silos for
storage of solids.
Waste water emanating from this part of the plant normally
results from storm run-off, tank washing, accidental spills, and
aqueous bottoms periodically drawn from storage tanks. Although
the generation rate is sporadic and the volume small, these waste
waters have in most cases contacted the chemicals which are
present in this area. For this reason, they are normally sent to
a process sewer and given the same effluent treatment as contact-
process waste waters.
Utility functions such as the supply of steam and cooling water
generally are set up to service several processes. Boiler feed
water is prepared and steam is generated in a single boiler
house. Noncontact steam used for surface heating is cirqulated
through a closed loop whereby varying quantities are made
available for the specific requirements of the different
processes. The condensate is nearly always recycled to the
boiler house, where a certain portion is discharged as blowdown.
The three major uses of steam generated within a chemical plant
are:
1. For noncontact process heating. In this application,
the steam is normally generated at pressures of 125 to
650 psig.
2. For power generation such as in steam-driven turbines,
compressors, and pumps associated with the process. In
this application, the steam is normally generated at
pressures of 650 to 1500 psig and requires superheating.
3. For use as a diluent, stripping medium, or source of
vacuum through the use of steam jet ejectors. This
steam actually contacts the hydrocarbons in the
manufacturing processes and is a source of contact
process waste water when condensed. It is used at a
substantially lower pressure than the foregoing and
frequently is exhaust steam from one of the other uses.
Steam is supplied to the different users throughout the plant
either by natural-circulation, vapor-phase systems, or by forced-
circulation liquid heat-transfer systems. Both types of system
discharge some condensate as blowdown and require the addition of
boiler makeup water. The main areas of consideration in boiler
operation are normally boiler efficiency, internal deposits,
corrosion, and the required steam quality.
Boiler efficiency is dependent on many factors. One is the
elimination of boiler-tube deposition that impedes heat transfer.
The main contributors to boiler deposits are calcium, magnesium,
silicon, iron, copper, and aluminum. Any of these can occur in
50
-------
FIGURE 111-5
PLOT PUN FOR CHEMICAL PLANT
ILLUSTRATING FOUR-AREA LAYOUT
I
UTILITIES
STEAM
GAS
AIR
REFRIGERATION
ELECTRIC WATER
TANK ) ( FARM
STORAGE AND HANDLING
PROCESS AREA
OO
BATTERY LIMIT
STORAGE
o o o
•• Or
II Mill MM Illlll II Mill
RAILWAYS
n
SERVICES
J
SHOPS
OFFICE
ROADS
L
-------
natural waters, and some can result from condensate return-line
corrosion or even from makeup water pretreatment. Modern
industrial boilers are designed with efficiencies on the order of
80 percent. A deposit 1/8 inch in depth will cause a 2-3 percent
drop in this efficiency, depending on the type of deposit.
Internal boiler water treatment methods have advanced to such a
stage that corrosion in the steam generation equipment can be
virtually eliminated. The control of caustic embrittlement in
boiler tubes and drums is accomplished through the addition of
sodium nitrate in the correct ratio to boiler water alkalinity.
Caustic corrosion in high heat transfer boilers can also be
controlled by the addition of chelating agents.
This type of solubilizing internal boiler water treatment has
been shown to be more effective than previous precipitation
treatment using phosphate.
Other factors influencing boiler efficiency include reduction of
the amount of boiler blowdown by increasing cycles of
concentration of the coxier feedwater, efficiency of the blowdown
heat recovery equipment, and the type of feed used.
Flash tanks are used in many plants to recover, as low-pressure
steam, as much as 50 percent of the heat lost from continuous
boiler blowdown. The steam is then used for the boiler feed
water deaerator or other low pressure applications. Additional
heat is recovered in some plants by installing heat exchangers
following the blowdown flash tank. The blowdown is used to
preheat the makeup boiler feed water in these exchangers.
Steam purity is of prime importance if:
1. The boilers are equipped with superheaters.
2. The boilers supply power generation equipment.
3. The steam is used directly in a process where
contamination could affect product quality or destroy
some material (such as a catalyst) essential to the
manufacture of the product.
The minimum purity required for contact steam (or contact process
water) varies from process to process. Limits for suspended
solids, total solids, and alkalinity vary inversely with the
steam pressure. The following tabulation summarizes boiler water
concentration limits for a system providing a steam purity of
0.5-1.0 ppm total solids, which is required for most noncontact
steam uses. It should be noted that the boiler operation must
incorporate the use of antifoam agents and steam separation
equipment for the concentrations shown to be valid.
52
-------
Parameters _ Boiler Pressure, Psig
IE!!! ~ 301-450" 45_li6C)£~ 601-750
Total Solids (mg/1) 6,000 5,000 4,000 2,500~"
Suspended Solids (mg/1) 1,000 200 100 50
Total Alkalinity (mg/1) 1,000 9CO 800 750
The concentrations of these contaminants found in actual boiler
blowdowns were generally within the ranges shown above.
Water conditioning or pretreatment systems are normally part of
the Utilities Section of the most plants. From the previous
discussions, it is obvious that the required treatment may be
quite extensive. Ion-exchange demineralization systems are very
widely employed, not only for conditioning water for high
pressure boilers, but also for conditioning various process
waters. Clarification is also widely practiced and usually
precedes the ion exchange operation.
Noncontact cooling water also is normally supplied to several
processes from the Utilities area. The system is either a loop
which utilizes one or more evaporative cooling towers, or a once
through system with direct discharge.
Cooling towers accomplish the cooling of water circulated over
the tower by moving a predetermined flow of ambient air through
the tower with large fans. The air-water contact causes a small
amount of the water to be evaporated by the air. Thus, through
latent heat transfer, the remainder of the circulated water is
cooled.
Approximately 1,000 BTU are removed from the total water
circulation by the evaporation of 1 Ib of water. Therefore, if
100 Ibs of water are introduced at the tower inlet and 1 Ib is
evaporated to the moving air, the remaining 99 Ibs of water are
reduced in total heat content by 1,000 BTU, or about 10 BTU/lb.
The 99 Ibs of water leaving the tower have been cooled 1°F/lb/BTU
removed, and the exit temperature is reduced by about 10°F This
leads to the common rule of thumb: 1 percent evaporation loss
for each 10°F.
Since cooling is primarily by transfer of latent heat, cooling
tower selection is based on the total heat content or enthalpy of
the entering air. At any one enthalpy condition, the wet bulb
temperature is constant. Therefore cooling towers are selected
and guaranteed to cool a specific volume of water from a hot
water temperature to a cold water temperature while operating at
a design wet-bulb temperature. Design wet-bulb temperatures vary
from 60°F •* 85°F depending on the geographic area, and are
usually equalled or exceeded only 2.5 percent to 5 percent of the
total summer operating time.
Hot water temperature minus cold water temperature is termed
cooling range, and the difference between cold water and wet-bulb
temperature is called approach.
53
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A closed system is normally used when converting from once-
through river cooling of plant processes. In the closed system,
a cooling tower is used for cooling all of the hot water from the
processes. Figure III-6 illustrates this method. With the
closed system, makeup water from the river is required to replace
evaporation loss at the tower.
Two other water losses also occur. The first is drift, which is
droplet carry-over in the air as contrasted to evaporative loss.
The cooling tower industry has a standarized guarantee that drift
loss will not exceed 0.2 percent of the water circulated. The
second loss in the closed system is blowdown to sewer or river.
Although blowdown is usually taken off the hot water line, it may
be removed from the cold water stream in order to comply with
regulations that limit the temperature of water returned to the
stream. Blowdown from a tower system will vary depending on the
solids concentration in the make-up water, and on the occurrence
of solids that may be harmful to equipment. Generally, blowdown
will be about 0.3 percent per 10°F of cooling, in order to
maintain a solids concentration in the recirculated water of
three to four times that of the make-up water.
The quantity and quality of the blowdown from boilers and cooling
towers depend on the design of the particular plant utility
system. The heat content of these streams is purely a function
of the heat recovery equipment associated with the utility
system. The amounts of waste brine and sludge produced by ion
exchange and water treatment systems depend on both the plant
water use function and the intake source. Usually none of these
utility waste streams can be related directly to specific process
units.
Quantitative limitations on parameters such as dissolved solids,
hardness, alkalinity, and temperature, therefore, cannot be
allocated on a production basis. The limitations on such
parameters associated with non-contact utility effluents will be
considered under Phase II.
The Service area of the plant contains the buildings, shops, and
laboratories in which most of the plant personnel work. The
sanitary wastes from this area obviously depend on the number of
persons employed. It should be noted that most chemical plants
run continuously and have 3 operating shifts per day. There are
also wastes associated with the operation of the laboratory,
machine shops, laundry, etc. The wastes from the Service area
normally are combined with the wastes from the process area prior
to treatment.
As was mentioned previously, there are a large number of process
combinations possible within rhe "Battery limits" of the typical
multiprocess plant. Choosing one of the many commercially viable
processes for the manufacture of a specific chemical at a
particular location or time is a decision based on a particular
manufacturer's unique situation.
54
-------
t-ri
Ln
FIGURE HI-6
CLOSED SYSTEM
HOT WATER
-------
Each process is itself a series of unit operations which causes
chemical and physical changes in the feedstock or products. In
the commercial synthesis of a single product from a single
feedstock, there generally are sections of the process associated
with: the preparation of the feedstock; the chemical reaction;
the separation of reaction products; and the final purification
of the desired product. Each unit operation may have drastically
different water usages associated with it. The type and quantity
of contact waste water are therefore directly related to the
nature of the various processes. This in turn implies that the
types and quantities of waste water generated by each plant's
total production mix are unique.
The production from a given process module is obviously related
to the design capacities of the individual unit operations within
it. In many cases the unit operations are arranged as a single
train in series. In other cases, some unit operations such as
the reaction are carried in several small reactors operating in
parallel.
The flow of material between unit operations within a process may
be either a continuous stream or through a series of batch
transfers. Both types of processes normally have an associated
design capacity which is generally expressed as millions of
pounds of product per year.
Typ.es Qf_Manufacturing Processes
There are two major types of manufacturing process within the
industry:
1. Continuous Processing Operations.
2. Batch Processing Operations.
Facilities utilizing continuous processes manufacture products in
much greater volumes than do batch operations. Although the
initial manufacture of many chemicals was first done by batch
processing, changes to continuous processing were made when
markets were enlarged to meet increasing and changing demands.
The reduction in plant cost per unit of production was the major
driving force behind this change.
Batch processing is still extensively practiced, particularly
when the production is small or where safety demands that small
quantities be handled at one time. Furthermore, batch operations
are more easily controlled when varying reaction rates and rapid
temperature changes are key considerations.
Demarcation between batch and continuous operations provides the
first working division of the industry into subcategories. Most
of the products and processes covered in Phase I are related to
continuous operations. This has provided sufficient information
to sub divide the continuous processes into three subcategories.
These will be fully defined later in this report.
56
-------
There is frequently a segregation of the equipment associated
with large continuous operations to the extent that each process
module is located in its own building or plant location. The
management of a large continuous process to be competitive,
efficans and profitable, may be the responsibility of an entire
division of the company. In such cases, the plant manager may
function as a landlord whose responsibility is to provide the
required utilities for each process module. In such operations,
there is usually complete segregation of contact process waters
from noncontact cooling water and steam.
Flow charts are normally used to show the coordinated sequence of
chemical conversions and unit operations within a continuous
process module. They indicate the points of entrance of raw
materials, noncontact media for heating and cooling, and the
places where products and wastes are removed. A flow chart can
normally be used to divide the process module into four
subsections:
Feed Preparation
Reaction
Product Separation
Product Purification
Each of these subsections can include several unit operations or
chemical conversions.
The feed preparation section may contain equipment such as
furnaces where the liquid feed is vaporized or heated to reaction
temperature, or large steam driven compressors for compressing
gaseous feed to the reaction pressure. It may contain
distillation columns to separate undesired feed impurities which
might damage the catalyst in the reactor or cause subsequent
unwanted side reactions. Impurities may also be removed by
preliminary chemical conversion (such as the hydrogenation of
diolefins) or by physical means such as silica gel driers to
remove trace amounts of moisture.
The reaction section of the process-module is where the principal
chemical conversions are accomplished. The reactor may be as
simple as a hollow tube used for noncatalytic vapor-phase
reactions. However, most industrial reactions are catalytic and
generally require more complex reactor designs. The specific
reactor design is usually governed by the required physical state
of the reactants and catalyst.
Catalysts are of two types: heterogeneous and homogeneous.
Heterogeneous catalysts are usually solids which may be composed
of chemically inactive material such as finely, ground aluminum or
contain metals such as cobalt, platinum, iron, or manganese which
are impregnated on a solid support. In heterogeneous reaction
systems, the reactants are usually in the vapor phase. The
conversion proceeds in three steps: adsorption of the reactants
upon the surface of the catalyst; chemical reactions on the sur-
57
-------
face of the catalyst; and desorption of the products from the
catalyst surface.
Homogeneous catalysts exist in the same physical state as the
reactants and products. This may require the use of an aqueous
or non-*aqueous solvent to provide a reaction media. Typical
homogeneous catalysts include strong acids, bases, and metallic
salts which may be in the form of a solution or a slurry. It
should be noted that the recovery, reconcentration, or
regeneration of these catalysts may require the use of processing
equipment much more elaborate than the reactor itself.
The recovery of reaction products may involve a wide variety of
processing operations. If the reactor effluent is a vapor, it
may be necessary to condense and quench the products in a direct
contact medium such as water. In many instances the desired
products are absorbed in water and are subsequently stripped from
the water by heating. Liquid reactor effluents are separated
from solvents (and catalysts) by distillation. In almost all
cases, the conversion of feed is not complete, so that continuous
separation and recycle of unconverted feed to the reactor is nec-
essary.
Final purification of the products is normally required both when
they are to be sold and when they are used as intermediates.
Most specifications restrict contaminant levels to the range of
parts per million. Because of this, additional operations such
as distillation, extraction, crystallization, etc. are necessary.
The product is pumped from the battery limits to tanks in the
storage area.
In large-scale continuous processes, all of the subsections of
the process module are operated with the use of automated
controls; in some cases, complete automation or computer control
is utilized. Recording instruments maintain continuous records
of process variables such as temperature, pressure, flow of
fluids, viscosity, and the composition of various process
streams. Instrumentation for the indicating, recording, and
control of process variables is an outstanding characteristic of
modern chemical manufacture. In many processes, the instrument
expense costs up to 5 percent of the total expenditure for the
process module. The function of the operators, mechanical
technicians, and supervising engineers in this type of operation
is to maintain the process module in proper running order.
When chemical manufacturing is on a small scale, or when it is
not adaptable to continuous procedures, a batch sequence is
frequently used. This requires more supervision on the part of
operators and engineers, because the conditions and procedures
usually change from the start to the finish. Batch operations
with small production and variable products also transfer
equipment from the making of one chemical to that of another
based on the same type of chemical conversion. Hundreds of spe-
cific products may be manufactured within the same building.
58
-------
This type of processing requires the cleanout of reactors and
other equipment after each batch. Purity specifications may also
require extensive purging of the associated piping. Rapid
changes in temperature during the batch sequence may also require
the direct addition of ice or quench water as opposed to slower
non-contact cooling through a jacket or coils.
Process waters from batch or continuous processes within the bat-
tery limits include not only water produced or required by the
chemical reactions but also any water which comes in contact with
chemicals within each of the process modules. Although the flows
associated with these sources are generally much smaller than
those from non-contact sources, the organic pollution load
carried by these streams is greater by many orders of magnitude.
The process RWL's from the battery limits can be put on a
meaningful production basis and form the basis for the effluent
limitations developed in this report.
Relationship._to Chemical_Process Economics
Each process module within the plant functions as a separate
economic entity, with a real or artificial price attached to the
final product or intermediate which it manufactures. This
selling price (or transfer price) is usually expressed as a
required realization including the cost of raw materials,
manufacturing cost, and return on the capital investment
associated with the process module.
The total materials cost is based on the price of the feedstock
minus any credits obtained for the concurrent production of co-
products or byproducts. Co-products are normally defined to be
salable commodities with their own markets. By-products are
normally materials such as gases produced by undesired side
reactions; these are usually credited only for use as auxiliary
fuel.
Manufacturing costs normally include the following items:
1. Labor and supervision.
2. Direct overhead.
3. General overhead.
4. Depreciation.
5. Repairs.
6. Utilities (power, steam, fuel, cooling water,
and process water)
7. Miscellaneous chemicals associated with catalyst
replacement, etc.
These items are added to give a total manufacturing cost.
The return on the total capital investment for the process module
is normally based on some specific pretax return (such as 20
percent) which the manufacturer charges or must pay for the
initial use of capital. The total capital investment normally
59
-------
includes the cost of the process module, initial working capital,
and startup costs.
when the three components are added together and divided by the
production of the desired product, they provide a required
realization or unit price which the manufacturer attaches to that
product. Other factors such as market penetration, sales build-
up, and overall trends in total industry capacity and industry
demand will then drive the actual selling price upward or
downward.
When the organic chemicals industry is considered as a whole,
there is a definite relationship between the total production and
the selling price for a specific chemical. This relationship is
illustrated in Figure III-7. As would be anticipated, high-
volume chemicals manufactured in large scale continuous processes
have a much lower selling price than do small volume batch
chemicals. As shown in Figure III-7, this relationship may be
correlated with the continuous and batch process categories for
the industry.
Required realizations based on typical size process modules
(production capacity indicated as millions of pounds per year)
are presented for the chemicals studied in this report. These
unit costs are expressed as cents per pound. They have been
broken down into the three components previously described.
Costs are also presented for the pollution control systems which
may be utilized tc comply with the effluent limitations. The
pollution control costs may be put on the same cents-per-pound
basis and added to the required realization to provide a
meaningful assessment of the economic impact on specific
products. Performing this calculation for several of the
products within a subcategory or between subcategories will
provide a basis for general conclusions relating to the industry
as a whole.
60
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FIGURE 111-7
RELATIONSHIP BETWEEN SELLING PRICE AND
TOTAL INDUSTRY PRODUCTION
I
3
1
g s z =
i Si
5 i ° 3
= t=
£ g 5
£
5
1
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u z
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oz z £ -
«z = " -
f = 1
_,
g
-I
ai
A
i
*
' ^
•
£^
?°z£ ° £° £~
oS = 8
^ oi^
0 « =
SS Q
(EQ. ZUJ
zz "z :
* *
*
A «A
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* A A
IssSss
°" m S0 Z «
= 1 "sji
11 "Is"
_1 CC
a:
« ^
1
t
A '
A- *
•
i
Z S^|S =
S z " o* S
I
S 5 5 :
S "g
z
A «
A A
A •
A
A
AA
•
i
is is^S^is
~< "S"- ^«
£_, »=»_. |jj
^u,:s! §"
S S z "
a s
A
A
• A
•A
A .
• A
* AA
-sill li
= S1S5 si
- S z >^ z •« £
§i L^r
5 x z
O-J
££ =
PHTHALIC AN
A
A
A •
• • •
V
•
•
•
•
CO Z Z —
£ ^ S "-
i ^
1 5
"*
-
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- «.-
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•
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ill mi
™s s ^ s £
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- ^ ^ a
i
• A
1* i
•
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S z z
= z >-
S °° £
=
S
UJ
• CATEGORY
• CATEGORY
A CATEGORY
>. •'
i
z
UJ
A (CCNTINUCUS
PROCESSES)
B (CONTINUOUS
ABSORBENT)
C (CONTINUOUS
AQUEOUS LI
SYSTEMS)
•
NON-AQUEOUS
PROCESSES Wl TH
PROCESSES WITH
QUID PHASE REACTION
500
100
100 200 500 1000 2000
TOTAL INDUSTRY PRODUCTION AS MILLIONS OF POUNDS PER YEAR
5000
10,000
20,000
50.000
-------
SECTION IV
INDUSTRY SUBCATEGORIZATION
Discussion of the Rationale of^ Subcategorization
The goal of this study is the development of effluent limitations
commensurate with different levels of in-process and end-of-pipe
pollution control technology. These effluent limitations will
specify the quantity of pollutants which will ultimately be
discharged from a specific manufacturing facility, and will be
related to the quantity of product produced.
The diverse range of products and manufacturing processes to be
covered suggests that separate effluent limitations be designated
for different segments within the industry. To this end, a
subcategorization of the Organic Chemicals Industry has been
developed. The subcategorization is process oriented. Chemical
commodities have been grouped according to the RWL associated
with their specific manufacturing process.
The relationship between the process raw waste load (RWL), pro-
cess water usage, and those specific unit operations and chemical
conversions which define the nature of the process is shown
below:
RAW "1
WASTE A
LOAD /
CONTACT ""I
PROCESS I
WATER )
USAGE I
NATURE
OF
PROCESS
MODULE
UNIT OPERATIONS
'(PHYSICAL SEPARATIONS)
CHEMICAL
CONVERSIONS
(REACTIONS)
Manufacturing processes have been examined for type of process
water usage associated with each. Process water is defined to be
all water which comes in contact with chemicals within the
process and includes:
1.
2.
3.
Water required or produced (in
quantities) in the chemical reaction.
stoichiometric
5.
Water used as a solvent or as an aqueous medium for the
reactions.
Water which enters the process with any of the reactants
or which is used as a diluent (including steam).
Water associated with the catalyst system, either during
the reaction or during catalyst regeneration.
Water used as an absorbent or as a scrubbing medium for
separating certain chemicals from the reaction mixture.
62
-------
6. Water introduced as steam to strip certain chemicals
from the reaction mixture.
7. Water used to wash, remove, or separate chemicals from
the reaction mixture.
8. Water associated with mechanical devices such as steam-
jet ejectors for drawing a vacuum on the process.
9. Water used as a quench or direct contact coolant such as
in a barometric condenser.
10. Water used to clean or purge equipment used in batch
type operations.
11. Runoff or wash water associated with battery limits
process areas.
The type and quantity of process water usage are related to the
specific unit operations and chemical conversions within a
process. The term "unit operations" is defined to mean specific
physical separations such as distillation, solvent extraction,
crystallization, adsorption, etc. The term "chemical conversion"
is defined to mean specific reactions such as oxidation,
halogenation, neutralization, etc.
Description of Subcategories
Four process subcategories have been established. Subcategories
A, B, and C relate to continuous processes, while Subcategory D
relates to batch processes. The subcategories are described as
follows:
Subcategory A - Nonaqueous Processes
Minimal contact between water and reactants or products
within the process. Water is not required as a reactant or
diluent and is not formed as a reaction product. The only
water usage stems from periodic washes of working fluids or
catalyst hydration.
Subcategory B - Processes^With Process Water Contact
as Steam Diluent or Absorbent
Process water usage is in the form of dilution steam, a
direct contact quench, or as an absorbent for reactor
effluent gases. Reactions are all vapor-phase and are
carried out over solid catalysts. Most processes have an
absorber coupled with steam stripping of chemicals for
purification and recycle. Steam is also used for de-coking
of catalyst.
Subcategory C - Continuous_Liguid-Phasg Reaction Systems
63
-------
Liquid-phase reactions where the catalyst is in an aqueous
medium such as dissolved or emulsified mineral salt, or acid-
caustic soution. Continuous regeneration of catalyst system
requires extensive water usage. Substantial removal of spent
inorganic salt by-products may also be required. Working
aqueous catalyst solution is normally corrosive. Additional
water may be required in final purification or neutralization
of products.
Subcategory D - Eatch^and_Semicontinuous Processes
Processes are carried out in reaction kettles equipped with
agitators, scrapers, reflux condensers, etc. depending on the
nature of the operation. Many reactions are liquid-phase
with aqueous catalyst systems. Reactants and products are
transferred from one piece of equipment to another by gravity
flow, pumping, or pressurization with air or inert gas. Much
of the material handling is manual with limited use of
automatic process control. Filter presses and centrifuges
are commonly used to separate solid products from liquid.
Where drying is required, air or vacuum ovens are used.
Cleaning of noncontinuous production equipment constitutes a
major source of waste water. Waste loads from product
separation and purification will be at least ten times those
from continuous processes.
Sample flow diagrams illustrating typical unit operations and
chemical conversions for a process within each category are
provided in Figures 1-1, 2, 3, and 4. The raw waste loads (RWL)
associated with each of the continuous process subcategories (A,
B, and C) are based on contact process water only. Most
continuous processes are able to achieve segregation and do not
include noncontact cooling water or steam. Subcategory D in-
cludes all water usage associated with the process in that rapid
cooling with direct contact is required in the manufacture of
dyes.
Basis for Assignment to Subcategories
The subcategorization assigns specific products to specific
subcategories according to the manufacturing process by which
they are produced. Where more than one process is commercially
used to produce a specific chemical, it is possible that the
chemical may be listed in more than one Subcategory, because the
unit operations and chemical conversions associated with dif-
ferent feedstocks may differ drastically in regard to process
water usage and associated RWL.
A comprehensive listing of the chemicals and manufacturing
processes which have been assigned to each of the four
subcategories is provided in Table 1-4. This listing includes
both the products and processes for which actual RWL data has
been obtained, as well as the remaining chemicals and associated
processes included under SIC 2815 and 2818.
64
-------
It is possible to assign products and processes to subcategories
based on a knowledge of the aqueous waste sources within a
specific process. This was initially done prior to the
collection of any quantitative field data, through a knowledge of
the specific unit operations and chemical conversions associated
with the process. RWL data obtained by field sampling and manu-
facturers' historical records were then used to confirm the
subcategorization and to provide quantitative boundaries. The
products and processes covered in Phase I are listed in Table 1-5
by subcategory.
The quantity of process water entering the process is normally
set by the requirements of chemical conversion. The most common
chemical conversions used within the industry were therefore
examined and are themselves subeategorized in the tabulation
below:
Subcatec[ory_A Sutcategprv B Subcate£or^_C Subcateqory__D
Acylation Amination Alcoholysis Alkylation
Alkylation Hydration Ammonolysis Amination
Aromatization Dehydration Dehydration Condensation
Friedel-Crafts Hydrogenation Esterification Nitration
Reactions Dehydrogenation Hydroformulation
Halogenation Oxidation Hydration
Pyrolysis Neutralization
Nitration
Oxidation
Many of these chemical conversions are quite complex.
Consequently, they are defined, along with the rationale for
their subcategorization, in the Glossary Section (XVI) of this
report. It should be noted that many of the more complex
processes and batch sequences incorporate several of these
chemical conversions.
Water may also enter the process through unit operations which
follow the chemical conversions and are required in the
separation or final purification of products. Some of these are:
1. Direct-contact quenching.
2. Absorption of gaseous chemicals in water.
3. Scrubbing of less volatile chemicals from a gaseous
product stream.
4. Stripping of more volatile chemicals from a product
stream (water enters as steam).
5. Vacuum distillation columns and the associated
condensate from steam jet ejectors.
6. Washing of chemicals from solid products.
65
-------
7. Washing or purging process lines and equipment in batch
sequence operations.
Water leaves the process through another group of unit operations
associated with the physical separation of water from
hydrocarbons. Some of these are:
1. Liquid-liquid separation equipment, such as decant
drums.
2. Vapor-liquid separation equipment, such as distillation
columns or flash chambers.
3. Solid-liquid separation equipment, such as crystallizers
and filters.
To be considered within Subcategory A, the unit operations and
chemical conversions within a process module must be essentially
anhydrous. Contact water usage shall be only in the form of
periodic washes or steaming used to treat non-aqueous catalysts
or working solvents. The other sources of waste water are from
external washing and maintenance operations within the process
battery limits. External water sprays utilized to provide
cooling on the outside of process pipes are considered as contact
process water. Such waste waters generally are contaminated
through contact with chemicals present on the ground within the
battery limits; consequently, they should be collected and
discharged to a process sewer for subsequent treatment.
Subcategory B processes are characterized by unit operations and
chemical conversions where the primary contact between water and
chemicals is through vapor-liquid interfaces. Although final
separation and discharge of water from the process may be as a
liquid from a decant drum, contact within the process is
normally: 1) through the mixing of steam with hydrocarbon
vapors; 2) gaseous chemicals passing counter-currently through an
aqueous absorption or quench medium; or 3) steam used to strip
more volatile chemicals from liquid hydrocarbon mixtures. In all
of these cases, the ultimate concentration of contaminants in the
aqueous stream is governed by the specific vapor-liquid
equilibria between the aqueous phases and the chemical phases.
Hydrocarbon concentrations as total organic carbon (TOO are
generally less than 1 mg/1 or 1,000 mg/1 in the aqueous streams
associated with this type of processing.
The chemical conversions associated with Subcategory C processes
are characterized by intimate contact between water and the
reaction mixture or catalyst system. Water is used as a reaction
medium in many of these systems because both the chemicals and
the catalyst are infinitely soluble. The chemical conversions
are generally multi-step reactions and generally more complicated
than the vapor-phase reactions in Subcategory B. (The Glossary
of Chemical Conversions provides specific examples.) The
Subcategory C reactions are also generally less selective in
66
-------
their yield to desired products and subsequently produce more by
products which must be removed from the system.
Typical unit operations involve liquid-solid interfaces where
water is used to wash contaminants from solid chemical products.
Because of the much larger quantities of chemicals and catalyst
present in aqueous soltion, most Subcategory C processes utilize
many of the same unit operations as in Subcategory Br for the
purpose of recovering these materials prior to discharging the
water. There is also much more extensive internal recycling of
aqueous process streams.
The hydrocarbon concentrations (as TOC) in the process waste
waters which are ultimately discharged are in some cases 10-fold
those for Subcategory B or approximately 10 g/1 or 10,OOQ mg/1.
The amount of contaminants, when expressed on a production basis,
is also higher because of the required removal of by-products
which are necessarily present in aqueous solutions.
Subcategory D refers to batch processes. These operations are
characterized by small production volumes and highly variable
mixtures of products. A typical batch dye plant manufactures a
wide variety of products at any specific point in time. This
product mix itself may change completely on a schedule basis as
short as one week. The segregation and characterization of
process waste water associated with the production of any one
specific dye is not possible, nor is it practical as a basis for
establishing effluent limitations. Instead, the total waste
water emanating from the batch plant is considered.
It is an economic necessity that equipment be transferred from
the making of one chemical to that of another in multi-product
batch plants. Although certain items may be used for only one
type of chemical conversion, product purity requires that process
lines and vessels be purged and cleaned between batches. Water
is the most common cleaning solvent used in such applications,
both because of the relatively low cost associated with its use
and because other organic solvents cannot provide the required
removal of contaminants. Wastewater from cleaning is, therefore,
a major contributor to the RWL of Subcategory D processes.
Additional considerations include the fact that most of the
chemical conversions are carried out in aqueous media and are
generally much
more complex than those done continuously. The reactions are
generally less selective and produce greater quantities of waste
by-products. They also frequently require rapid cooling which
can be provided only through the direct addition of ice or
refrigerated quench water.
Field sampling within Subcategory D in Phase I of this study was
limited primarily to dye plants. The sampling results indicate
that both contaminant loadings and process waste water flows are
higher than for continuous processes. Supplementary information
67
-------
on other batch operations, to be obtained in Phase II, may show
that these processes are not subject to all of the waste-
generating operations associated with dyes. If this proves to be
the case, additional subcategories will be established.
In subsequent sections, separate effluent limitations are
established for each subcategory. The process modules within
each subcategory generate a certain range of raw waste load,
which is characteristic of the subcategory. The effluent
limitations are then based on the characteristics and
treatability of each subcategory^ RWL.
By its very nature, the subcategorization implicitly considers
factors such as raw materials, production processes, and
products, as well as the quantity and treatability of the wastes
generated. Additional factors, (such as plant size or plant age)
were examined, but did not justify further subcategorization
based on the Phase I coverage.
It should be noted that the intensely competitive nature of this
industry requires continual process modification and improvement
of product yields. Process modules may in many instances contain
chemical conversion steps or unit operations which were not
originally part of the process. Also, no definable trend between
waste water flow or RWL (on a production basis) and the
production rate from a given process module was detected. The
only discernible difference appeared to be between low-volume
batch and high-volume continuous processes, which had already
been divided into separate subcategories.
The following pages contain individual profiles of the products
and processes studied in Phase I sampling visits. The profiles
are grouped according to category. They develop a complete
technical and economic picture for each of the processes studied.
68
-------
SUBCATEGQRY A
Product Process
Cyclohexane Hydrogenation of Benzene
Cyclohexane can be obtained as a naturally occuring petroleum
fraction or through the hydrogenation of benzene. The chemical
reaction for the production of Cyclohexane from benzene is given
below:
C6H6 + 3H2 _+ C6H1.2
Benzene Hydrogen Cyclohexane
The reaction is usually carried out in the liquid phase with a
nickelpalladium or platinum catalyst at elevated temperature and
pressure. Fresh feed (benzene) is combined with makeup and
recycle hydrogen and preheated to reaction temperature by heat
exchange first with reactor effluent and then with steam. The
reaction effluent is cooled and flashed. Part of the vapor is
used as recycle hydrogen, while the forward-flow vent gas is
chilled by refrigeration to minimize Cyclohexane losses and is
available as high-pressure fuel gas. The separated liquid is
sent to a column where the light-end impurities are taken
overhead.
A flow sheet for this process is shown in Figure IV-1.
The Cyclohexane process surveyed utilized a C6, hydrocarbon
feedstock containing a high concentration of benzene. The only
contact process waste water associated with the process is a
spent caustic wash containing 5-10 wt.X NaOH. The flow raw waste
load for this stream is quite low and amounts to only 0.24 gal
per 1,000 Ib of Cyclohexane when expressed on a production basis.
The contact caustic wash was necessary in the operation of this
process because of the high sulfur content of the feedstock.
This sulfur would reduce the useful life of the precious metal
catalyst if it were not removed prior to the hydrogenation
reaction. It was not possible, based on this one survey visit,
to determine if the sulfur content of the feed was abnormally
high and whether or not other Cyclohexane units would require
this type of caustic treatment of the feed.
The U.S. Cyclohexane capacity and estimated economics for
Cyclohexane are presented in Tables IV-1 and IV-2.
69
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FIGURE IV-1
CYCLOHEXANE
HYDROGEN
BENZENE
DRYER
VENT (TO FLARE)
OFF-GAS RECYCLE
REACTOR
V/L
SEPARATOR!
l
FUEL GAS
DISTILL
PRODUCT
CYCLOHEXANE
-------
Table IV-I
U.S. Cyclohexane Capacity
(MM gal)
Company
Ashland (Catlettsburg, Ky.)
Arco (Wilmington, Calif.)
Conoco (Lake Charles, La.)
(Ponca City, Okla.)
Cosden (Big Spring, Texas)
Enjay (Baytown, Texas)
Gulf (Port Arthur, Texas)
Phillips (Borger, Texas)
(Las Mereas, P.R.)
(Sweeney, Texas)
Pontiac (Corpus Christ!, Texas)
Shell-Corco (Guayanilla Bay, P.R.)
Texaco (Port Arthur, Texas)
Union (Nederland, Texas)
Total,
Totar (MM Ib)
19671
20
15
4o
4o
8
40
33
47
46
30
12
30
40
434
2,820
19722
30
15
shut down
shut down
8
40
33
47
46
53
12
30
40
Process
Benzene
Petroleum
Benzene
Petroleum
Benzene
387
2,520
»82% based on benzene hydrogenation.
,74% based on benzene hydrogenation.
^6.5 Ib/gal.
Source: Oil. Paint & Drug Reporter Prof Me. Jan, 1, 1969.
Table IV-2
Estimated Economics for.Cyclohexane
(100 MM Ib. plant)
Total Fixed Capital= $0.5 MM
Estimated Operation Cost
Cost.
Benzene (at 3.4«;/lb.)
Hydrogen
Labor and overhead
Utilities, catalyst
Capital charges
Total
cyclohexano
3.15
0.38
0.08
0.03
0.16
71
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SUBCATEGORY A
Product Process
Ethyl benzene Alkylation of benzene with ethylene
Some ethyl benzene is recovered in refinery fractionation
operations, but the majority is manufactured via the alkylation
of benzene with ethylene. The alkylation reaction is:
C6H6 + C2H2 C6H5C2H5
Benzene Ethylene Ethyl Benzene
A process flow sheet is shown in Figure IV-2. Ethylene and feed
benzene are combined with recycle benzene and polyaromatics,
heated to reactor temperature, and introduced to the alkylation
reactor. Off-gases from the reactor pass to the scrubbing
system. The reactor effluent is passed to the separation
section. Unreacted benzene is recycled, ethyl benzene is drawn
off as the product, and polyethyl benzenes are recyled or drawn
off as waste effluents.
If high purity benzene feedstock is used, the crude product is
not required to be washed with caustic solution and water.
However, the plant visited during the survey employs a feedstock
containing some organic contaminants, and washing is necessary
before the crude product is sent to the separation step. The
washing step also removes any traces of the BF3_ promoter.
The major waste streams of this process are the spent caustic and
washing streams used to wash the crude alkylate. Significant
amounts of tars, benzene, ethyl benzene and other polymers will
be found in these streams. Heavy aromatics fractions from the
separation column are disposed of by incineration.
The data obtained from the plant survey are summarized in the
following tabulation:
Flow 37.7 gallons/1,000 Ib
COD 5,980 mg/1
1.88 lb/1,000 Ib
BODS 433 mg/1
0.136 lb/1,000 Ib
TOG 2,091 mg/1
0.66 lb/1,000 Ib
Ethyl benzene was recategorized under Subcategory Bl since the
washing step is considered a common industry practice.
The alternate route in manufacture of ethyl benzene is a liquid-
phase reaction using aluminum chloride catalyst. The process
requires much more extensive washing to remove highly acidic
aluminum chloride catalyst. It is usually employed in
72
-------
s dehy<*rogenation step to produc*
U.S. ethyl benzene capacity is shown in Table IV-aT
FIGURE IV-2
ETHYLBENZENE
BENZENE RECYCLE
OFF GAS
CAUSTIC SOLUTION
WATER
INDIRECT STEAM
WATER AND CAUSTIC
WASH
IHD. STEAM'
RECYCLE
ETHYL BENZENE
•IND. STEAM
' WASTEWATER 1
-*WASTEWATER 2
PURGE (HEAVY AROMATICS)
73
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Table IV-3
U.S. Ethyl Benzene Capacity
Estimated Mid-1970 Capacity
Producer
Amoco
Coastal States
Corco
Cosden
Cos-Mar
Dow
El Paso
En jay
Foster Grant
Monsanto
Shell
Signal
Sinclai r-Koppers
Sun
Tenneco
UCC
Plant Location
Texas City, Texas
Corpus Christ!, Texas
Penuelas, P.R.
Big Springs, Texas
Carvi 1 le, La.
Freeport, Texas
Midland, Michigan
Odessa, Texas
Bay town, Texas
Baton Rouge, La.
Alvin, Texas
Texas City, Texas
Torrance, California
Houston, Texas
Houston, Texas
Corpus Christ!, Texas
Port Arthur, Texas
Chalmette, La.
Institute, W.Va.*
Seadrift, Texas
Alkylation
950
-
-
110
650
750
if 50
200
175
800
900
280
-
85
550
-
130*
350
Recovery
35
100
25
-
-
-
70
-
50
-
35
100
30
-
20
-
TOTAL
6,250
* Plant not currently operating but not dismantled.
Not included in total.
** MM Ibs/yr.
74
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SUBCATEGORY_A
Product Process
Vinyl Chloride Acetylene and HC1
The classical acetylene addition reaction proceeds in the vapor
phase with high-purity acetylene and anhydrous hydrogen chloride
as reactants. The chemical reaction is given below:
C2H2 + HC1 —+• C2H3C1
Acetylene Hydrogen Vinyl Chloride
Chloride
A process flow sheet is shown in Figure IV-3. The feed stocks,
acetylene and anhydrous hydrogen chloride, are fed into tubular
reactors which are packed with mercuric chloride impregenated on
granular activated carbon. The reactor effluent is sent to a
three column distillation system for purification, and purified
vinyl chloride is taken as bottoms of the last column.
Because no water comes into direct contact with the reactants and
products and no reaction water is generated, there is no direct"
contact process waste water. However, in the plant visited a
"Mercury Treatment System" is associated with this process. This
system is used for treating rainfall (which picks up traces of
mercuric salts on the surface of the concrete pads and equipment)
and periodic distillation column and reactor cleanouts. It is
also used to treat the water from surface sprays which cool the
outsides of process lines within the process battery limits.
Based on flow measurements and sampling of these waste waters,
the following RWL was calculated:
Flow RWL (gal/1,000 Ib) 240
COD RWL (lb/1,000 Ib) 3.7
The waste water is collected by a segregated sewer and is pumped
into one of two alternate storage tanks. When the storage tank
is full, sodium sulfide is added to precipitate mercuric sulfide.
Two activated carbcn columns, connected in series, are used to
polish the filtrate.
The Mercury Treatment System is a batch operation. The effluent
from the activated carbon column is totally recycled to the
storage tank until the mercuric concentration has been decreased
to approximately 0.5 micrograms/1. The mercury sludge from the
filter press as well as saturated activated carbon is placed in
drums and buried or removed by a contractor who recovers mercury.
The analytical results for a single batch are presented below:
Before After
Treatment Treatment
75
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COD(mg/l) 1,836 1,306
TOC(mg/l) 448 33
SS(mg/l) 1,124 24
Hg (micro-
grams/1) 2,600 4.1
A more recent, process for manufacture of vinyl chloride is by the
route of thermal cracking of ethylene dichloride. This process
will be discussed in Subcategory B.
76
-------
FIGURE IV - 3
VINYL CHLORIDE, ACETYLENE ADDITION
WITH ANHYDROUS HYDROGEN CHLORIDE
ANHYDROUS HCI
VENT GAS
VINYL CHLORIDE
ACTIVATED
CARBON COLUMNS
Na2S
DISCHARGE
-------
SUBCATEGORY_A
Product Process
Benzene, Toluene and Xylene(BTX) 1. Hydrogenation Pyrolisis
Aromatics Gasoline from Ethylene
Manufacture
2. Solvent Extraction
A mixture of BTX aromatics and saturates may be obtained as a by-
product of ethylene manufacturing (by pyrolysis of naptha
feedstocks). This mixture must first be stabilized by
hydrotreating prior to the recovery of BTX aromatics by solvent
extraction.
Two-Stage Hydrolysis Gasoline Hydrotreater
The first stage hydrotreating of pyroiysis gasoline differs from
convention hydrotreating of virgin stocks in that the feedstock
is difficult to handle and cannot be heated to the 500-700°F
temperatures needed for conventional hydrotreating. Water
injection is not required and the process itself should be non-
polluting. In the low temperature processes, diolefins and other
reactive compounds are hydrogenated to yield a product which can
be stored or handled in conventional refinery and petrochemical
processing.
The second stage hydrotreater is similar to the conventional
refinery hydroterater with a colbalt/moly catalyst. Under
certain conditions it may be necessary to prefractionate the feed
to these processes as heavy polymers can rapidly deactivate
catalyst. Frequently steam stripping, or steam injection with
the fractionator feed is used in these operations. The
condensate must then be disposed of.
The catalysts used for the first stage hydrotreating operation
contain either nickel or a noble metal. They require more
frequent regeneration than most refinery catalysts. Once in
about four months may be a reasonable number. The steam-air
decoking may result in an air pollution problem.
Some plants contain a provision to inject water to wash out
ammonium bisulfite salts which might be formed in the reaction.
In this case, a coalescer, or water separator, would be used to
separate this water. This operation would only be performed
intermittently, and would not be a major source of waste water.
A flow diagram for the pyrolysis gasoline hydrotreater is shown
in Figure IV-4. The feedstock and recycled hydrogen gas are
preheated and passed through a series of hydrotreating reactors
containing platinum catalyst. The reactor effluent is cooled and
then discharged into a separator, where the gas stream taken
overhead is recycled back to the reactor after being scrubbed
with caustic solution. The liquid phase from the reactor is
passed through a coalescer (where water is used to trap coke
78
-------
r
i
t
t
EXTRACTOR
WATER
STILL
SOLVENT
REGENERATION
•"^t
5 O
i c
<~>
c m
09 '"*'
S 5 3
C I °
zo S
—i *» —
m
X -0
-H -<
ij -<
O
o
r—
Z
-------
particles formed in the pyrolysis reactor) and a stabilizer
(where light hydrocarbons are removed).
They survey data obtained from a plant with pyrolysis gasoline as
feedstock are shown in the following tabulation. The data
presented can be considered as the standard for all levels of
control technology of this process.
Flow 13.6 gal/1,000 Ib
COD 2,755 mg/1
0.31 lb/1,000 Ib
BOD5 914 mg/1
0.104 lb/1,000 Ib
TOC 306 mg/1
0.034 lb/1,000 Ib
As shown in Figure IV-3 the only sources of waste water are in
the hydrotreating section of the process.
BTX Extraction
The stabilized liquid is then extracted with a solvent (di- and
tri-ethylene glycol) to recover the aromatics, and the raffinate
(containing paraffins) is sent to a cracking furnace to produce
olefins. The dissolved aromatics (BTX) are separated from the
solvent by distillation, and the solvent-free aromatics are water
washed and then separated into the individual components:
benzene, toluene, and xylene. The separated solvent
regenerated and recycled to the process, while the sludge
produced is disposed by landfill. There are many solvents that
will extract aromatics from napthas at high recoveries and
purities, but for many reasons only a few are used commercially.
In recent years, several refiners have switched from di- and tri-
ethylene glycol to tetra ethylene glycol. A change to tetra
ethylene glycol can usually be achieved with minor equipment
modifications and no change in royalty status. The most recent
development shows that sulfolene has established itself in the
U.S. as the preferred solvent for BTX extraction. Although the
results and economics of using sulfolene have not been published,
it is known that drastic changes in process conditions and a
relatively high solvent cost cause a large capital investment for
this solvent change. The sulfolene system differs from other
solvent systems in that the solvent regeneration is under vacuum.
If steam ejectors with barometric condenser are used to produce
the vacuum, the resultant oily water will be a significant water
pollution source. Therefore, BPCTCA and BATEA levels of control
technology for the sulfolene system will require vacuum pumps
with surface condensers to produce vacuum for process needs, and
the resulting oily stream should be disposed of by incineration.
The U.S. capacity for Benzene and Toluene is presented in Table
IV-4.
80
-------
Table IV-U
U.S. Benzene and Toluene Capacity
Benzene and toluene capacity, 1965
MM Ibs/yr
Producer
Location
Benzene
from petroleum
Extraction Dealkylation
All ied
Amoco
Ashland
Atlas Processing
Conoco
Cosden
Crown Central
Dow
En jay
Gulf
Hess
Leonard
Marathon
Monsanto
Phillips
Pont iac
Richfield
Shell
S ignal
S i nclai r
Socony-Mob i 1
South Hampton
Standard (Calif.)
Sun
Sunray-DX
Sunt ide
Tenneco
Texaco
Union-At lant ic
Union Carbide
Union Oil
Vickers
Subtotals
Total from petroleum
Total from coal
Grand Total
.ource: Based on Oil.
Winnie, Texas
Texas City, Texas
Buffalo, N.Y.
Catlettsburg, Ky.
Shreveport, La.
Lake Charles, La.
Ponca City, Okla.
Big Spring, Texas
Houston, Texas
Bay City, Mich.
Freeport, Texas
Baton Rouge, La.
Bay town, Texas
Philadelphia, Pa.
Port Arthur, Texas
Corpus Christ! , Texas
Mount Pleasant, Mich.
Detroit, Mich.
Texas City, Texas
Alvin, Texas
Sweeney, Texas
Corpus Christ!, Texas
Wi Imi ngton , Cal i f .
Houston, Texas
Odessa, Texas
Wi 1m! ngton , Ca 1 i f .
Wood River, Calif.
Houston, Texas
Houston, Texas
Marcus Hook, Pa .
Beaumont, Texas
S i 1 sbee, Texas
El Segundo, Cal i f .
Ri chmond, Cal i f ,
Marcus Hook, Pa.
Tulsa, Okla.
Corpus Christ! , Texas
Chalmette, La.
Port Arthur, Texas
Nederland, Texas
S. Charleston, W. Va.
Lemont, 111.
Potwin, Kans.
Paint & Drug Reporter. June
30.0
110.0
75.0
100.0
75.0
^5.0
^5.0
65.0
**5.0
175.0
180.0
110.0
230.0
220.0
55.0*
^5.0
250.0
160.0
65.0
130.0
220.0
35.0
110.0
220.0
20.0
220.0
180.0
70.0
110.0
80.0
70.0
110.0
220.0
130.0
75.0
160.0
20.0
k, 3^*0.0
5,965.0
130.0
6,095.0
1**, 1965
1*5.0
110.0
95.0
11*5.0
220,0
220.0
90.0
20.0
185.0
110.0
11*0.0
1*5.0
90.0
110.0
1 ,625.0
To 1 uene
1^*5.0
60.0
80.0
110.0
70.0
125.0
110.0
360.0
110.0
35.0
130.0
25.0
120.0*
85.0
230.0
95.0
175.0
220.0
70.0
70.0
110.0
110.0
11*5.0
1*5.0
180.0
1+5.0
175.0
60.0
180.0
30.0
95.0
60.0
11+5.0
11+5.0
70.0
70.0.
35.0
l+, 125.0
1*. 125.0
50.0
l*. 175.0
; Hydrocarbon Processing,
February 1966.
--Toluene and benzene shipped as a
essed there.
blend to Dow at Bay City, Mich., and finally proc-
81
-------
SUBCATEGORY A
Product_ Process
BTX Aromatics Solvent Extraction from Reformate
Alternately, solvent extraction may be employed on Cj5-C_8
reformate cuts to extract aromatics from low octane paraffins.
The raffinate could be fed to synthetic natural gas(SNG)
generation or a petrochemical facility or, alternately, recycled
to the catalytic reformer. The extraction unit here might be of
different design than a unit for chemical production in that high
purities and recoveries are not required.
As the refinery picture is complex, similarly it is difficult to
predict the growth of extraction processes.
Sulfolene, or other solvent, become a loss in three ways which
affect waste disposal:
1. Solvent degradation - Units have provision for solvent
regeneration but periodically heavy materials must be purged,
2. Losses to products due to incomplete water wash.
3. Leaks
A recent estimate in a sulfolene unit was that 30 Ib of sulfolene
make-up were required for 1,000,000 Ibs of feed. Published
information on Udex operation indicated losses about three times
as great. (For Udex, .031b/barrel of feed. Oil and Grease
Journal 5/7/62.) These then represent the material, either as
solvent, or degradation products, which can go to waste streams.
It appears that sulfolane has established itself in the U.S. as
the preferred solvent for BTX extraction. A recent article
^Hydrocarbon Processing, 3/73) advocates digylcloamine as a
superior solvent. It would require major design revisions to
convert a Udex Unit to sulfolane operation. The article
apparently concedes that sulfolane is preferred for completely
new installations.
The sulfolane system differs from other solvents in that the
solvent regeneration is under vacuum, in a 1000 BPSD feed plant,
about 5,0001b/hr of lOOlb steam might be required to maintain the
necessary vacuum for one design, and this quantity of oily
condensate must be disposed of. If surface condensing is not
used, but barometric condensers used, the quantity of oily water
to be disposed of increases by a factor of 10-50 (water required
to condense the steam).
It is difficult tc project the future requirements for new
solvent extraction units. With high severity reforming required
for low-lead or no-lead gasoline, there should be ample benzene
in reformate so that there should be no need to extract toluene
for conversion to benzene. Furthermore, for other chemical
82
-------
purposes toluene requirements are small and consequently toluene
will be left in the gasoline pool. In high severity reforming
the C8 aromatic fraction contains very little paraffins and
paraxylene can be produced by crystallization without solvent
etraction. With this argument, solvent extraction will only be
used on reformate for benzene where the solvent/feed requirements
are minimal. Consequently, existing facilities may be adequate
and no new units may be required for refineries.
RWL data for the UDEX solvent extraction process are summarized
below:
Flow RWL (gal/1,000 Ib BTX extract): 60.4
TOC RWL (lbs/1,000 Ib BTX extract): 0.144
The U.S. xylenes producers are shown in Table IV-5.
83
-------
Table IV-5
U.S. Xylene Capaci ty
(MM gal Ions/year)
Producer
Ashland
Atlantic Richfield
British Petroleum
Chevron Chemical
Cities Service
Coastal States
Commonwea 1 th
Cosden Oi 1
Crown Central
Enjay Chemical
Hess Oi 1
Leonard Refineries
Marathon Oi 1
Mobi 1
Monsanto
Phi 11 ips
Pontiac Refining Co.
Shell Chemical
Si gnal Oi 1 and Gas
Southwestern Oi 1
Standard Oil (1 ndiana)
Sun Oi 1
Tenneco, Inc.
Union Oi 1 Co.
Union Oi l/Arco
Union Carbide
TOTAL
Plant Location
Catlettsburg, Ky.
Buffalo, N.Y.
Houston, Texas
Marcus Hook, Pa.
El Segundo, Calif.
Richmond, Calif.
Lake Charles, La.
Corpus Christ!, Texas
Guayani 1 la Bay, P.R.
Big Spring, Texas
Houston, Texas
Baton Rouge, La.
Baytown, Texas
Corpus Christ!, Texas
Mt. Pleasant, Mich.
Detroit, Mich.
Texas City, Texas
Beaumont, Texas
Chocolate Bayou, Texas
Guayamas, P.R.
Corpus Christ! , Texas
Houston, Texas
Houston, Texas
Corpus Christ!, Texas
Texas City, Texas
Marcus Hook, Pa.
Corpus Christ!, Texas
Chalmette, La.
Lemont , 111.
Nederland, Texas
Ponce, P.R.
Source
a
a
a ,c
a
a
a
a
a
a.b
a
a
a,b
a
a
a
a
a
a,b
b
a
a
a
a
a
a
a
a
a
a
a
b
Estimated
Capaci ty*
35
10
60
30
23
49
72
2k
79
18
10
41
50
30
3
15
14
1+1
41
55
18
70
22
18
124
30
35
50
39
46
73
1,225
-'••From reformate and pyrolysis gasoline.
Does not include coke oven operations.
a = Reformate
b = Pyrolysis gasoline
c = Toluene DiSproportionation
84
-------
SUBCATEGQRY B
Product Process
Ethlyene and Propulene Pyrolysis of Hydrocarbons
Ethylene and proylene are produced primarily by the pyrolysis of
saturated hydrocarbons. In the U.S., ethane and propane
currently predominate as feedstock material. The chemical
reactions for their pyrolysis are given below:
C2H6 C2HU + H2
Ethane """^ Ethylene Hydrogen
2 C3H8 C3H6 + H2 + C2Hjf + CHU
Propane "•*• Propylene Hydrogen Ethylene Methane
A process flow sheet is shown in Figure IV-5. The hydrocarbon
feedstock is diluted with steam and passed thourgh a pyrolysis
furnace, where cracking takes place. Normal temperatures in the
cracking section of the furnace are 1,500 to 1,600 F, and
residence time is one second or less. The purpose of steaqm
dilution is to depress any coking tendency within the furnace
tubes.
In order that only the desired degree of cracking be obtained,
the hot reactor effluent gases are cooled rapidly to a
temperature which will quench the cracking reaction.
Consequently, the cracked gases are cooked in a variety of ways,
but usually at some point by direct contact with water in the
quench tower.
After quenching, the cracked gases are compressed prior to
treatment for removal of the contained acidic gases (CO2 and
H2S) . The acid gases are usually absorbed by some combination of
systems using monoethanol amine (MEA), caustic, and water. The
purified gas stream is then dried and further compressed before
f ractionation.
After compression, the dried, cracked gas is cooled to cryogenic
temperatures, and hydorgen is flashed off and sent either to
additional purification facilities or burned as fuel. The
dehydrogenated stream flows to the demethanizer, where overhead
methane is sent to fuel, and the C^+bottoms flow, un,der pressure,
to the de-ethanizer.
At the de-ethanizer the C3, and heavier materials are taken off as
a bottoms stream and are sent to the de-propanizer. The de-
ethanizer overhead is selectively hydeogenated in the light
acetylene converter, in order to remove trace amounts of
acetylene; this stream then goes to the C2_ splitter, where the
ethylene and ethane are sepatated. Ethane is recycled to the
cracking furnace, and the overhead from the splitter is the
product ethylene and is sent to storage.
85
-------
FIGURE IV-5
ETHYLENE, PROPYLENE- PYROLYSIS OF HYDROCARBONS
SURFACE
TRANSFER LINE
HEAT EXCHANGERS
ETHANE AND
PROPANE
STEAM
H.P. STREAM
BOILER FEED WATER
COOLING AND
PRIMARY
FRACTIONATION
]
COMPRESSION
ACIDGAS
* REMOVAL ~~
1
lUHPTruiJiTrn
COMPRESSION REFRIGERATION
CONOENSATE
WASTEWATER
WASTEWATER
METHANE
I
CH4
COLUMN
— ft
r
C2
COLUMN
i
r
L
_»ETHYLENE
C2
SPLIT-
TER
1
ETHANE
-»
|~
C3
COLUMN
L
I * PROPYLENE
C2
SPLIT-
TER
* PROPANE
•^•^
C4
COLUMN
PYROLYSIS GASOLINE
-------
The ££ + depropanizer bottoms are sent to the debutanizer, and
the overhead is selectively hydrogenated in the heavy acetylene
splitter in order to remove trace amounts of methyl acetylene and
propadiene. The de-propanizer overhead goes to the C3 splitter
where the propane and propylene are separated. The final tower
in the fractionaticn train is the debutanizer, where various CU
compounds are separated from the dripolene or pyrolysis gasoline
fraction. The C5 and heavier materials may be rejected as waste
or amy be used as a source of aromatics. U.S. ethylene capacity
is shown in Table IV-6.
The major areas ©f water usage in the cracking process relate to
dilution steam requirements and the contact quench waters
required in the cooling and primary separation of the cracked gas
products.
Pressure and hydrocarbon partial pressure are extremely important
variables in the design and operation of ethylene plants. From
an ethylene yield viewpoint, it is best to minimize pressure, or
more specifically, hydrocarbon partial pressure. Low pressure is
an economic problem since it increases the compression
requirements following reaction. Instead of running the reaction
at low pressure, steam is used as a diluent to reduct the
hydeocarbon partial pressure. The steam also serves as a heating
the cold feed.
For each feed there is an economic optimum of pressure and steam
rate as the affect investments operating costs and product
yields. Typical weight ratios of steam to hydrocarbon feed are
as follows: gas feeds - 0.3 naphtha feeds - 0.5; gas oil feeds -
0,7.
After cooling in the surface transfer line heat exchangers, the
pyrolysis furnace effluent must be cooled* further to a
temperature suitable for economic compression. This cooling is
generally carried out" in a tray tower of more than one section.
In addition to cooling the gases, heavy ends present in the
furnace effluent must be scrubbed out. Because the quantity of
heavy .ends is very different when cracking gasoil, naphtha or
ethane and propane, the tower design and function is different
for each case.
In a plant where ethane or propane is cracked, the pyrolysis
effluent contains very little hudeocarbon material that will
condense at atmospheric conditions. Thus, when the gas is cooled
to compressor suction conditions, only water and trace quantities
of hydrocarbons condense. However, it is important that the
hydrocarbon be removed from the gas since it is a tarry material
that will foul the downstream processing equipment. The paint
includes a sketch of a typical quench tower system for an ethane-
propane plant. The hot gases enter the tower at the bottom and
pass up through a baffled section passing through curtains of
downflowing water. The gas is cooled to approximately 200 F
(93.5 C) in the baffled section, and then pases to a tray section
where cooling to approximately 105°F (UO°C^ takes place, the
87
-------
Table IV-6
U.S. Ethylene Capacity (1972)
Company
Allied Chemical (Geismar, La. )
Arco (Wilmington, Calif.)
Chemplex (Clinton, La.)
Cities Service (Lake Charles, La.)
Conoco (Lake Charles , La).
Corco (Penuelas, P. R.)
Dow (Bay City, Michigan)
(Freeport, Tx.)
(PIaquemi ne, La.)
DuPont (Orange, Tx.)
Eastman (Longview, Tx.)
El Paso (Odessa, Tx.)
Enjay (Batone Rouge, La.)
(Baytown, Tx.)
(Bayway, N. J.)
Goodrich (Calvert City, Ky.)
Gulf (Cedar Bayou, Tx.)
(Port Arthur, Tx.)
Jefferson Chemical (Port Neches, Tx.)
Mobil (Beaumont, Tx.)
Monsanto (Alvin, Tx.)
(Texas City, Tx.)
National Distillers (Tuscol.a, 111.)
Northern Petrochemicals (Joliet, 111.)
Olin (Brandenberg, Ky.)
Phillips (Sweeny, Tx.)
Phillips-Houston (Sheeny, Tx.)
Shel1 (Deer Park, Tx.)
(Norco, La.)
(Torrance, Calif.)
Sinclair-Koppers (Houston, Tx.)
Sun Olin (Claymont, Delaware)
Union Carbide (Institute, W. Va.)
(Ponce, P.R.)
(Seadrift, Tx.)
(S. Charleston, W.Va.)
(Taft, La.)
(Texas City, Tx.)
(Torrance, Calif.)
(Whiting, Ind.)
Feedstock
ethane-propane
refinery gas
ethane-propane
propane
ethane-propane
naphtha
naphtha
ethane-propane
ethane-propane
ethane-propane
ethane-propane
ethane-propane
ethane., gas oi 1 &
naphtha
refinery gas
ref i nery gas
propane
propane
refinery gas &
propane
refinery gas, ethane
& propane
refinery gas £•
naphtha
refinery gas
refinery gas
ethane-propane
ethane-propane
ethane
ethane-propane &
refinery gas
ethane-propane
propane & refinery
gas
ethane-propane &
refinery gas
propane
ethane-propane &
refinery gas
refinery gas
ethane-propane
refinery gas &
naphtha
ethane-propane
ethane-propane
ethane-propane &
naphtha
ethane-propane
refinery gas
refinery gas
MM 1 b
500
100
500
1,000
500
1,000
170
1 ,400
600
750
450
400
1,000
85
175
250
400
1,000
500
500
600
100
350
800
90
600
500
1,200
500
70
500
220
350
1,000
900
400
Source: Informations Chiemie. May, 1970 p. 157
-------
exact, temperature being: a function ot the available cooling water
temperature. Fractionation
between the heavy materials and the gasoline and lighter overhead
also takes place in this trayed section. Heat is recovered in
two stages so that maximum use is made of the heat in the gas. A
larger settling drum is required to provide the separation
between water, oil and tar.
In a plant where naphtha is being cracked, significant quantities
of fuel oil are produced which can be sepatated int he quench
tower, ferquent-.ly termed the primary fractionator. There are a
number of different designs for this area. One common design is
a combination oil and water tower which eliminates overhead
condensers and their attendant pressure drop ahead of the
compressors. The lower section is a fractionator refluxed with
cracked gasoline distillate which knocks down any fuel that might
otherwise flow up the tower with the cracked gas. The upper
section i& a water wash tower or spray condenser, where raw
gasoline and dilution steam are condensed. The gasoline and
water mixture is withdrawn from the bottom of this section as
reflux while the net production goes to a distillate stripper,
before delivery to battery limits as raw product. The wash water
can be used for certain low level heating services such de-
ethanizer and propylene splitter rebelling before returning to
the top section of the tower.
Gas oil cracking requires yet another type of design due to the
very much larger quantity of gasoline and heavier material. The
design of this tower begins to approach the design of crude oil
distillation column. There are many possible designs for this,
depending upon the products required. The lower sections of the
primary fractionator constitute distillation similar to a crude
column, while the top sections are water wash sections. The
bottoms from the fractionator are shown going to a vacuum flash
tower to rpoduce an additional vacuum distillate; this additional
product would notmally be required only when cracking heavy
gasoils and when the fuel oil product is substantial.
The major waste water sources in the cracking process are draw-
off s from the water quench tower and the scrubber for removal of
acid gases. Other possible sources are the water draw-offs from
compressor interstages. The data obtained from the sampling
program are summarized in the following tabulation.
o... Flow _ _COD BOD5 TOO
gal/1,000 Ib lb/1,000 Ib Ib/l7o<30 Ib lb/1,000 Ib"
(mg/1) (mg/1) (mg/1)
364 1.75 0.39 0.48
(533) (130) (259)
150 2.29 0.35 2.02
(1,827 (279) (1,617)
89
-------
5
6
554
52.5
145
167
3.16
(684)
0.66
(1,502)
N.A.
6.16
(5,110)
0.65
(467)
0.88
(189)
0.088
(200)
N.A.
0.32
(265)
0.27
(192)
1.12
(242)
0.43
(980)
N.A.
2.14
(1,770)
0.75
(538)
Historical RWL data were also collected wherever they were
available, and were subjected to analysis for probability of
occurrence. The following tabulation presents the results of the
analysis.
Plant 3
Plant 5
Occurrence
10%
50%
90%
10%
50%
90%
Flow
N.A.
N.A.
N.A.
305
410
515
COD
lb/1,000lb
1.6
4.0
6.4
0.40
1.98
3.60
_ _TOC_
Ib/l7o00~lb
0.6
1.05
1.51
N.A.
N.A.
N.A.
The probability analysis for Plant 5 covered monthly average data
for a period of 12 months; for Plant 3 it covered seven random
daily samples for a period of 3 months. For the other plants
there was not sufficient historical data for a full statistical
analysis and comparison of the sampling data of all the plants.
Review of the available data reveals significant variations of
RWL among the plants. The volume of wastwater per unit of
product varies dependent primarily on the extent of scrubber
water. At some plants, the use of steam strippers facilitates
the reuse of quench water and minimizes the loss of hydrocarbons,
thus generating a lower RWL; the organic loading in the wastwater
is also affected by the performance of the quench towers and
scrubbers. Higher RWL's in some cases are the result of
contaminants in the feedstock.
The noncontact steam used in an ethylene plant is generated from
extremely pure water because of the high pressure conditions.
Most of this steam is recovered as condensate and returned to
the boilers. A large quantity of steam, however, is used to
contact dilution steam in the cracking reaction. When this steam
is condensed from the process gases it is recovered as a fouled
condensate and is not suitable for use as boiler feed water or
90
-------
any other purpose. In some locations, even disposal of this
steam is a problem.
Most of the boiler feed water make-up in an ethylene unit is
requied to replace this condensed material. Since the boiler
feed water make-up must be suitable for high pressure steam
generation, the net result is the extremely pure water is
degraded to fouled condensate. As plants have increased in size
and steam pressures have increased, the differential cost in
boiler feed water treating has become significant and directed
consideration to recovery of this water. The obvious recovery
method is to generate steam that is suitable for use as dilution
in the cracking furnaces. This steam is required at 100-150
pounds per square inch guage pressure (psig) and the water
quality is not critical as in the case of high pressure steam.
By removing the dilution steam requirement from the main steam
system, the high pressure steam system becomes a closed loop and
the only losses are to leaks and blowdown.
The principles of recovery of the condensed dilution steam for
reuse are simple. In order for the condensed material to be used
as feed water for a vaporization system, it must be stripped of
oils which would rapidly foul an exchanger used to vaporize this
water. Then, since the water contains solids that must be
purged from the system, heavy blowdown from the vaporizer is
required to remove these solids. A well designed water system
permits recovery of 90 percent of the steam used in hydrocarbon
dilution and reduces the overall boiler feed water make-up
requirements to less than 20 percent of the requirements without
a clean-up system. Unless boiler feed water make-up is
inexpensive because of existing high purity treating facilities,
water clean-up is an economic addition to a new paint and is
always included.
Since 1967, ethylene plants have incorporated the use of steam
condensate strippers in order to reuse waste water effluent and
minimize hydrocarbon effluent in waste waters.
These facilities will generally require the use of a steam
strippper and steam dilution. In addition, 2 pumps, and a steam
reboiler are required. Investments for these facitities for a 5
x 108 Ib/yr gas cracker are shown in Table IV-7 as $240,000.
Figures IV-6 and IV-7 are process flowsheets for quench tower
loops without and with a condensate stripper.
The increment operating costs are shown in Table IV-8. On
ethylene product, it represents an increase of about .010 and on
the waste water reduction it represents .150/U.S. gal of water
saved.
T'
The water draw-off from compressor interstages could be combined
with the condensate stripping operation since it would only
increase the quantity of water handled by about 20-25 percent
without incurring any other handling problems. This water would
probably be returned to the quench tower for re-processing.
91
-------
Table IV-7
Investment for Condensate Stripping*
I. Process Water Stripper k1 & 8' I.D. x 39' High
Including:
12 - Trays
1 - 240 GPM Pump
1 - 250 GPM Pump
1 - Filter
Instruments, Piping, Foundations, etc. $160,000
II. Dilution Steam Drum 7' I.D. x 20' High
Including:
2 Heat Exchangers
Instruments, Piping, Foundations $ 80,000
TOTAL $240.000
*For a 500 MM Ib/yr ethylene plant using C?/C, feed,
totally installed, U.S. Gulf Coast location, 1973.
92
-------
FIGURE IV-6
WATER QUENCH WITHOUT CONDENSATE STRIPPER
(500MM LB./YR. ETHYLENE PLANT WITH C2/C FEEDSTOCK)
100°F COOLED GAS TO COMPRESSION
153,500 #/HR.
105°F 430,000 #/HR.
c.w. - >
FURNACE EFFLUENT FROM
TRANSFER LINE HEAT
EXCHANGERS
187,000 #/HR.
BOO°F
130°F 1,182,250 #/HR.
LOW LEVEL
HEAT REMOVAL
HIGH LEVEL
HEAT
RECOVERY
1,645,750 #/HR.
T
CONDENSED OIL
180°F
I I
43,000 #/HR.
WATER
Y
CIRCULATING WATER
2850 #/HR.
WATER MAKE-UP
12,350 #/HR.
1,599,900 #/HR.
-------
FIGURE IV-7
WATER QUENCH WITH CONDENSATE STRIPPER
(500 MM LB./YR. ETHYLENE PLANT WITH C2/C3 FEEDSTOCK)
110 °F COOLED GAS TO COMPRESSION
153,500 #/HR.
105°F 430,000 #/HR.
C.W.
3260 #/HR.,
FURNACE EFFLUENT
FROM TRANSFER LINE HEAT
EXCHANGERS 187,000 #/HR.
4
TAR
TO
Dl
cunouti i v
SPOSAL
7con\
(
180°F
1
1 vL
1
1,
r
/•
n —
BOOPF,
8 PSIG
130°F 1, 182,250 #/HR.
LOW LEVEL
HEAT REMOVAL
HIGH LEVEL
HEAT
RECOVERY
r
CONDENSED OIL
2850 #/HR.
DILUTION STEAM
43,000 #/HR.
110 PSIG
TO FURNACE
STEAM
3000 #/ HR.
MAKE-UP
WATER
12,250 #/HR
CIRCULATING
WATER
1,600,000 #/HR.
X 38'
130°F
t
6000 #/HR SLOWDOWN
94
-------
Table IV-8
Incremental Operating Costs
for Condensate Strippers*
Incremental:
Steam - 6500 Ib/hr (Stripping + Vaporization)
Electricity-Pumps - 40,000 Kwh
Saving of 74 GPM of wastewater or boiler feedwater
Operating Cost/Year
Steam $32,000
Powe r 400
32,400
B.F.W. Ik GPM $.40/MUSG (14^400) Credit
Net Utility Cost $18,000
Investment Items:
Depreciation 24,000
Maintenance, Insurance and Other 11,000
$35,000
TOTAL $53,000/Year
Cost/lb of C2 = .011$
Cost/gallon of water saved =
*Note: For a 500 MM Ib/yr ethylene plant using C /C, feed.
95
-------
Table IV-9 presents the U.S. plants which are known to operate
with condensate strippers.
To define BADCT and BATEA technology, a steam stripper is
required to reuse the waste water from the quench tower. With
the installation of steam stripper, contamination attributable to
the quench water would be eliminated, and the resulting RWL's
would be as follows:
Plant No
—•—•
Flow
COD
BOD5
gal/1,000 Ib
364
50
11
52.5
10
lb/1,000 Ib
(mg/1)
1.57
(533)
1.83
(a,400)
0.77
(8,550)
0.66
(1,500)
0.48
(5,860)
Ib
(mg/1)
0.39
(130)
0. 19
(450)
0.43
(4,800)
0.09
(200)
0.12
(1,500)
jroc
ib/i7boo ib
(mg/1)
0.48
(159)
1.77
(4,250)
0. 13
(1,450)
0.43
(980)
0.63
(7,700)
The RWL's of plants 1 and 4 are the same as in the previous
tabulation because steam stripping has already been implemented
at those plants. Plant 6 is missing from this tabulation because
sampling at that plant (of the combined streams of quench water
and scrubber water) precluded separate calculation of RWL without
quench water.
The high waste water flow of Plant 1 is attributed to high water
usage in the scrubber; recycle of scrubber water could reduce the
waste water flow but not the organic loading. The calculated
data for Plants 3, 4, and 7 can be considered as representative
of the RWL for the process and can be used as criteria for BATEA
and BADCT control technology.
96
-------
Table IV-9
U.S. Ethylene Plants Using Condensate Strippers
1. Al1ied, Geismar
2. DuPont, Orange
3. Northern Petrochemical
4. Monsanto, Alvin
5. Union Carbide, Seadrift
6. Union Carbide, Texas City
7. Shel1, Deer Park
8. Continental, West Lake
9. Cities Service, Lake Charles
10. Dow, Freeport
11. Union Carbide, Taft
12. Enjay, B.R.
13. Dow, Freeport
14. Amoco, Texas City
15. Shell, Norco
600
750
800
650
,400
,250
,000
550
1 ,000
500
1,200
500
750
1 ,000
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
MM Ib/yr Ethylene
In construction
Announced
97
-------
SUBCATEGORY B
Product __________ Process ________________
Butadiene 1. Co-Product of Ethylene Manufacture
2. Dehydrogenation of n-Butane
Butadiene is produced as the by-product of the cracking of
hydrocarbons or by dehydrogenation of Cf*. hydrocarbons, such as n-
butane or butylenes, or as a co- product of ethylene manufacture.
1 . Dehvdrogenation cf n-butane
The one-step catalytic dehydrogenation of n-butane is carried
out in the vapor phase with solid chromium-on-alumina
catalyst. The reactors operate under vacuum at approximately
3 pounds per square inch absolute (psia) to obtain low
hydrocarbon partial pressures. This prevents excessive
coking on the catalyst. The chemical reaction is given
below:
CH3CH2CH2CH3 — 4» CH2 = CHCH = CH2 + 2H2
n-butane 1-3 butadiene Hydrogen
A process flowsheet is shown in Figure IV-8. The feedstock
(n-butane) and recycled butane and butenes are fed into a
battery of fixed-bed reactors. The reactor effluent is oil-
quenched, compressed, and sent to an absorption column, where
hydrocarbon vapor is absorbed with light oil. The effluent
from the absorber is then passed through a series of
distillations where unreacted butane and butene are separated
for recycle to the dehydrogenation reactors. Butadiene is
separated from the butene splitter overhead by extractive
distillation with furfural or cuprous ammonium acetate (CAA)
extraction.
A different process for producing butadiene from C4
hydrocarbons was employed by one plant visited. The process
dehydrogenates butane to butylenes using superheated steam as
a diluent. After separation from light and heavy by-
products, the butylenes are converted to butadiene by
oxidative dehydrogenation. This reaction is illustrated
below:
CUH8 + 1/2 02 ««*. C4H6 + H2.0
Butylene Oxygen Butadiene Water
2 • Co- product of ethvlene manufacture
Butadiene is also produced by extraction from the Gj£ and
heavier residue produced in ethylene manufacture. As shown
in Figure , the C± residue goes to an extractive
distillation with furfural or cuprous ammonium acetate (CAA)
extraction. The effluent is then sent to a steam stripper
98
-------
66
r
P
EXTRACTIVE
DISTILLATION
STRIPPING
COLUMN ""I
DISTILLATION
COLUMN
CO
3
DO
c
D
m
Z
s <
o
z
CP
c
m
-------
and fractionator, where heavy ends are removed. The stream
taken overhead from the fractionator is further washed with
water to remove solvents.
The dehydrogenation of n-butane produces waste waters from
scrubbing the gases used to periodically burn coke from the
catalyst surface, and from the steam ejector-barometric condenser
systems used to obtain vacuum in the reactors. The process also
produces wastewaters from the final recovery of butadiene
product. Waste waters generated by the process wherein butadiene
is formed as a co-product of ethylene manufacture are essentially
the same as those from the final recovery unit in the
dehydrogenation process. Survey data obtained from plant visits
are summarized in the following tabulation:
Plant
No.
Process £122 COD
gal/l7o001b lb/1,000lb
(mg/1) (mg/1)
1 Dehydrogenation, 1,160 3.23
Extractive Distillation (334)
2 Dehydrogenation, 1,451 245
Extractive Distillation (20,200)
3 Co-product of ethylene 88 1.120
Extractive Distillation (1,525)
4 Co-product Ethylene 339 3.899
Extractive Distillation (1,378)
5 Co^product of Ethylene 183 1.042
Extractive Distillation (683)
BOD5
lb/1,000~lb
(mg/1)
2.96
(306)
72
(5,960)
0.547
(745)
1.183
(418)
0.165
(102)
TOC
Ib
(mg/1)
Since furfural has a relatively high boiling point, it can be
easily separated from product butadiene by distillation.
Furfural loss in the waterwashing step is minimal. The process
(Plant 4) utilizing extraction with cuprous ammonium acetate must
be equipped with a water scrubber to remove CAA from the final
product and therefore produces considerable more waste water as
well as a higher RWL. The data presented by Plants 3, 4, and 5
confirm the above argument and can be considered, respectively,
as representatives of BPCTCA for the ethylene co-product process
with extractive distillation and extraction. However, to define
BPCTCA and BATEA control technology, a steam stripper should be
used to recover solvents, furfural, or CAA from the scrubber
water, which would then be recycled. With this in- process can be
reduced to the following levels:
Flow
COD
BOD5
65 gallons/1,000 Ib
0.43 lb/1,000 Ib
0.18 lb/1,000 Ib
0.554
(755)
1.545
(546)
0.313
(205)
100
-------
TOC 0.21 lb/1,000 Ib
As indicated in the data tabulation, RWL's presented by the two
dehydrogenation plants show a significant variation. Although
these two plants represent two different dehydrogenation routes,
as described in the preceding paragraph the variation is due
mainly to less effective operation of wash columns and strippers
rather than to differences in the processes. Consequently, the
data presented by Plant 1 should be considered as representative
of BPCTCA.
Since the dehydrogenation reactor is operated at approximately 3
psia, steam ejectors with barmetric condensers are used to
produce the vacuum, and these generate an excessive amount of
waste water. A vacuum pump system, such as that described in the
Styrene section can substantially reduce the amount of waste
water and also eliminate organic losses in the exhaust stream.
To define BADCT and BATEA control technology for the
dehydrogenation process, steam ejectors should be replaced with
vacuum pumps and a steam stripper should be installed to recover
organic solvent, as described in the ethylene co-product
processes.
An alternate route for butadiene manufacturing is the
dehydrogenation of n-butene. It is a vapor phase reaction with a
catalyst of iron oxide promoted by chromium oxide, magnesium-iron
oxide, or calcium nickel phosphate. Butadiene is produced
through several dehydrogenation reactors (in parallel) containing
fixed bed catalysts. The reaction gases are quenched and cooled
in a series of quench towers. The condensate containing CJ4-
hydrocarbons is charged to a fractionating column where it is
stabilized. The stabilized condensate is then treated for the
removal of polymerized materials. Finally, the crude butadiene
is purified by absorption or extractive distillation.
The U.S. butadiene capacity and the estimated economics for a
one-step dehydrogenation plant are presented in Tables IV-10 and
IV-11.
101
-------
Table IV-10
U. S. Butadiene Capacity (19&5)
From butane
El Paso
Firestone
Phil lips
Petro-Tex
Shell
ARCO
Sub Total
From butylenes
Gopolymer
Goodr ich-GuIf
Enjay
PCI (Cities Service)
Texas-U. S.
Petro-Tex
Sub Total
Olef in plant Clt
Chevron Chem.
Dow
Enjay
Mobi I
Monsanto
Union Carbide
T idewater
Sub Total
Grand Total
Location
Odessa, Texas
Orange, Texas
Borger, Texas
Houston, Texas
Torrance, Calif.
Channelview, Texas
Baton Rouge, La.
Port Neches , Texas
Baytown, Texas
Lake Charles, La.
Port Neches, Texas
Houston, Texas
MM Ibs/yr.
130.0
220.0
224.0
220.0
140.0
242.0
,176.0
120.0
320.0
66.0
160.0
320.0
280.0
1,266.0
El Segundo, Calif.
Freeport, Texas
Baton Rouge, La.
Beaumont, Texas
Alvi n, Texas
Seadrift, Texas, etc.
Delaware C i ty, Del.
32.0
64.0
110.0
50.0
100.0
140.0
14.0
510.0
2,952.0
Source: .Oil. Paint and Drug Reporter, October 24, 1966.
Table IV-11
Estimated Economics for Butadiene
[100. MM Ib. plant, One-Step Dehydrogenation
Total Fixed Capital=$17. MM
Estimated Operation Cost
Cost
Butane (at 1.4
-------
SUBCATEGORY B
Methanol
Process
Steam Reforming of Natural Gas
All of the processes for synthetic methanol involve the basic
steps of steam reforming of natural gas plus addition of carbon
dioxide to adjust the C/H ratio, compression, synthesis in a
catalytic converter, and distillation for purification. The
following reactions summarize the basic chemistry:
1. CH4
Methane
H20
Water
2.
3.
CO
Carbon
Monoxide
C02
Carbon
Dioxide
2H2
Hydrogen
3H2
Hydrogen
CO +
Carbon
Monoxide
CH3OH
Methanol
CH3OH
Methanol
3H2 (synthesis)
gas)
Hydrogen
H20
Water
The optimum atomic ratio for C/H in methanol synthesis is 1/U as
indicated above. However, carbon dioxide is added to take care
of extra hydrogen resulting from steam reforming of natural gas.
The traditional conversion to methanol is carried out at high
pressure (4,500 psig) in the presence of a chromium oxide-zinc
oxide catalyst at about 650°F. However, a new process operates
at only 750 psig and 500°F. by using a new active copper
catalyst. The much lower pressures allow the use of centrifugal
compressors rather than reciprocating compressors, and also allow
use of hydrogen-rich synthesis gas without having to add carbon
dioxide. Also, the conversion of natural gas to methanol is much
higher in the low-pressure process than that in the high-pressure
process.
A flow sheet for methanol synthesis is shown in Figure IV-9. The
synthesis gas, after compression, is charged together with
recycle gas to the reactor. The methanol-bearing gas leaving the
reactor is cooled by heat exchange with air or water. The
condensed crude methanol is separated from unreacted gas, which
is recycled to the reactor. The flashed, gas-free crude methanol
from the separator is purified by distillation.
The only waste water stream from methanol plants using lOOSt
natural gas feedstock is the aqueous stream from the final
methanol distillation column. Processes which utilize off-gases
from acetylene manufacture as feedstock introduce impurities into
103
-------
FIGURE IV-9
METHANOL
NATURAL GAS
BY- PRODUCTS
STEAM
METHANOL
WASTE WATER
ADDITION OF C02 (SUCH AS FROM
ACETYLENE PLANT OF B.O.F. FOR
ADJUSTMENT OF C TO H RATIO)
-------
the system. These impurities must be removed before crude
methanol can be purified. Usually, the impurities are first
oxidized by a strong oxidizing agent; this is followed by
sedimentation, filtration, and cation exchange. The results of
survey data are shown in the following tabulation:
FLOW
COD
BOD5
TOC
Plant I
59 gallons/1,000 Ib
320 mg/1
0.16 lb/1,000 Ib
119 mg/1
0.059 lb/1,000 Ib
107 mg/1
0.053 lb/1,000 Ib
Plant 2
U2.2 gallons/1,000 Ib
4,930 mg/1
1.74 lb/1,000 Ib
2,620 mg/1
0.92 lb/1,000 Ib
583 mg/1
0.21 lb/1,000 Ib
Plant I utilizes the low-pressure system with natural gas as
feedstock; Plant 2 uses off-gases from acetylene manufacturing as
part of its feedstock. The RWL of Plant I is representative of
the low-pressure process, and can be considered as standard for
BADCT and BATEA. The higher RWL of Plant 2 is due to impurities
introduced with the off-gases. A preliminary fractionator can
take the place of a series of treatments of crude methanol, and
the impurities can be removed from the fractionator and disposed
of by incineration. The RWL could then be e'xpected to approach
that of the low-pressure process. There is no significant
difference in waste water characteristics between the high- and
low- pressure processes. Only minimal carryover of metal
catalyst is expected.
The U.S. production of methanol and the estimated economics are
shown in Tables IV-12 and IV-13, respectively.
105
-------
Company
Table IV-12
U.S. Methanol Capacity (1972)
Location
Allied
Borden
Celanese
Commercial Solvents
DuPont
Escambia
Georgia-Pacific
Hercules
Monsanto
Rohm and Haas
Tenneco
Union Carbide
South Point, Ohio
Geismar, La.
Bishop, Texas
Clear Lake, Texas
Sterlington, La.
Orange, Texas
Beaumont, Texas
Huron, Ohio
Pensacola, Fla.
Plaquemine, La.
Plaquemine, La.
Texas City, Texas
Deer Park, Texas
Pasadena, Texas
Texas City, Texas
TOTAL
MM qa11ons
25
160
100
200
50
130
200
30
50
100
80
100
22
60
k2
1.3^9*
*8.9 billion Ib/yr
Source: Oil, Paint and Drug Reporter, Chemical Profile,
September 27, 1971.
106
-------
Table IV-13
Estimated Economics for Methanol
(costs in C/gal)
Capacity in tons/day
Output, MM gal/yr
Process
Compressor
Capital cost, $ million
Variable costs, e/gal*
Labor, maintenance,
supervi sion
Fixed costs (plant,
depreciation)
Cost to manufacture
S, G & A
20% return, BFIT
Sales value (FOB)
Sales value (FOB)
(same basis, naphtha
6.5£/gal)
Symbols: Ip = low-pressure
hp = high-pressure
c = centrifugal
r = reciprocal
"Natural gas at 20
-------
SUBCATEGORY B
Product_
Acetone
Process
Dehydrogenation of Isopropanol
Acetone is produced by dehydrogenation of isopropanol.
Fresh and recycle isopropanol are vaporized and fed to a tubular
reactor at typical operating conditions of 5 psig and 450-550°C.
A brass catalyst is commonly used. Conversion of isopropanol is
about 90 percent per pass, and selectivities to acetone are above
95 percent. The reactor effluent is passed into an absorption
tower to clean up the hydrogen formed in the reaction. The water
solution from the absorption tower is then purified by
conventional fractionation techniques, and unconverted
isopropanol is recycled back to the reactor. Figure IV-10
summarizes the important process units in the dehydrogenation
process, and the cheirical reaction is given below:
^ CHOHCH3
Isopropanol
CH3COCH2
Acetone
+ Eg
Hydrogen
In this process, water is used to absorb product acetone and
unreacted isopropanol from the hydrogen produced. After
fractionation, one or two waste water streams are produced as
bottoms from the isopropanol stripping still or as bottoms from
the intermediate flash column. The waste water contains acetone,
isopropanol, and small quantities of heavier organic substances.
RWL of this process from survey data in plant visits is
summarized as follows:
Flow
COD
BOD5
TOC
Plant_l
230 gallons/1000 Ib
246 mg/1
0.47 Ib./lOOO Ib
91 mg/1
0.18 Ib./lOOO
Ib
132 mg/1
0.25 Ib./lOOO Ib
Plant 2
120 gallons/1000 Ib
1,720 mg/1
1.72 Ib./lOOO Ib
338 mg/1
6.34 lb/1000 Ib
473 mg/1
0.47 Ib./lOOO Ib
Based on process information, it is concluded that the RWL of
Plant 1 is representative of BPCTCA. Since the contaminants in
the bottoms of the isopropanol stripping still have low
concentrations of volatile organic compounds, this stream can be
totally recycled to the absorber as absorbing water. The waste
water stream from the intermediate flash column can also be
recycled to reduce fresh water usage, contaminant concentration
in the intermediate flash column waste water is a function of the
column design; recycle of the above mentioned streams will not
108
-------
FIGURE IV-10
ACETONE, DEHYDROGENATION OF ISOPROPANOL
o
to
ACETONE
ISOPROPANOL
REACTOR
C.W.
AVENT
ADSORDER
WATER
c.w.
WASTEWATER
WASTEWA TER
-------
change the characteristics of the existing waste stream. With
this process modification, RWL of BADCT and BATEA can be expected
to achieve the following values:
Flow 100 gallons/1000 Ib
COD 103 mg/1
0.086 }b./1000 Ib
BOD5 53 mg/1
0.044 Ib./lOOO Ib
TOC 52 mg/1
0.043 Ib./lOOO Ib
The difference in RWL between the two plants is attributed to
poor performance of the isopropanol stripping still of Plant 2.
Average process water usage of this process is about 1.18 pounds
water per pound of acetone, while cooling water usage amounts to
119 pounds water per pound of product.
Acetone can also be produced by several alternate routes. The
most important recent development has been production of acetone
as a co-product in the cumene-to-phenol process. Another
alternate process is the oxidation of isopropanol. The oxidation
process is also vapor-phase and is carried out with brass or
copper catalysts.
The economics of the acetone market are conditioned by the fact
that the acetone produced as a co-product in the cumene-to-phenol
process can be credited at a low price. The U.S. acetone
capacity by various processes is shown in Table IV-13. Estimated
economics for acetone via vapor-phase dehydrogenation appear in
Table IV-14. The estimated economics for acetone via vapor-phase
dehydrogenation and the U.S. acetone capacity by various
processes are shown in Tables IV-14 and IV-15.
110
-------
Table IV-14
U.S. Acetone Capacity
(MM Ib)
Location
1967
1970 1972
Process
Amoco
Al1ied Chemical
Celanese
Chevron
Clark Oil
Dow
Eastman
En jay
Georgia Pacific
Hercules
Monsanto
Shel1 Chemical
Skelly Oil
Union Carbide
USS Chemicals
Texas City, Texas
Philadelphia, Pa.
Bishop, Texas
Ri chmond, Cali f.
Chi cago, 111.
Freeport, Texas
Kingsport, Tenn.
Bayway, N.J.
Plaquemine, La.
Gibbstown, N.J.
Alvin, Texas
Houston, Texas
Dominquez, Calif.
Norco, La.
Houston, Texas
El Dorado, Kansas
Marietta, Ohio
Bound Brook, N.J.
Institute, W. Va.
Texas City, Texas
Whi t i ng , Ind.
Ponce, P.R.
Haverhill, Ohio
Total
% cumene based
% isopropanol based
% propane based
1967
29. 4
68.3
2.3
-
150
35
35
35
-
90
110
-
30
35
30
150
100
180
30
-
87
120
130
120
-
-
1,467
1968
33.4
64.3
2.3
-
190
35
35
35
-
90
110
-
30
80
30
150
100
180
30
-
87
120
130
120
-
-
1.552 1
1970
34.3
63.8
1.9
-
190
35
35
35
-
90
110
120
30
80
30
150
100
245
30
-
87
120
130
120
-
120
,857
240
300
35
35
35
240
90
110
120
-
225
30
150
100
400
30
175
87
120
130
120
120
120
3,012
1972
46.4
52.5
1.1
Isopropanol
Cumene
Propane
Cumene
Cumene
Cumene
Isopropanol
Isopropanol
Cumene
Cumene
Cumene
Cumene
1 sopropanol
1 sopropanol
Isopropanol
Cumene
Cumene
Cumene
1 sopropanol
1 sopropanol
1 sopropanol
Cumene
1 sopropanol
Source: Oil. Paint £- Drug Reporter. Oct. 4, 1970.
Table IV-15
Estimated Economics for Acetone
(50. MM Ib. plant)
Total Fixed Capital=$0.6 MM
Estimated Operation Cost
Cost.
Isopropanol
Utilities
Labor and overhead
Capital charges
Hydrogen
Total
C/lb. acetone
4.7
0.9
0.3
0.4
-0.2
6.1
111
-------
SUBCATEGORY B
Product
Acetaldehyde
Process
1. Oxidative-Dehydrogenation of Ethyl Alchohol
2. Dehydrogenation of Ethyl Alcohol
Acetaldehyde is produced in the United States by processes using
ethylene, ethyl alcohol, or liquified petroleum gas as feedstock.
The breakdown of 1970 U.S. capacity for each route is shown
below:
Feedstock
Ethylene
Ethyl Alcohol
LPG
Process
Oxidation
Oxidative-
Dehydrogenation
Oxidation
Percent of 1970
U^Sj Capacity
56
36
8
The following discussion is of the ethyl alcohol route;
remaining routes will be discussed under Subcategory C.
the
In the oxidative-dehydrogenation process, ethanol and air enter
an oxidation furnace. The primary reaction is given below:
C2H5OH
Ethanol
1/2 02
CH3CHO
H20
Oxygen
Acetaldehyde Water
The reaction is vapor-phase and is carried out over a solid
silver gauze catalyst at about 1,000°F. The reactor effluent is
condensed and is passed to a phase separator. The gaseous phase
is absorbed in refrigerated water. Off-gases pass from the
system, and the wash is combined with the liquid stream. The
combined liquid stream is fractionated into product acetaldehyde,
alcohol for recycle, and waste water.
Dehydrogenation of ethanol is based on the chemical reaction:
C2H5)OH
Ethanol
CH3CHO
Acetaldehyde
H2
Hydrogen
This reaction is also vapor phase and is carried out over a solid
copper catalyst promoted by cobalt or chromium on an asbestos
support at 500°F.
A flow sheet for the oxidative dehydrogenation process
in Figure IV-11.
is shown
112
-------
FIGURE IV-11
ACETALDEHYDE, OXIDATIVE DEHYDROGENATION
H,0
OFF GAS
STEAM
REACTOR
OXIDIZER
AIR
ETHANOL
AND H20
t
SCRUBBER
i
AUtlALUtHTUt
FLASH COLUMN
ACETALDEHYDE
STILL
WASTEWATER
ETHANOL
-------
These processes yield from 85 to 95 percent of the stoichiometric
amount of acetaldehyde. The only waste water stream generated in
these processes is either from the acetaldehyde flash column or
the ethanol recovery still, and contains liquid by-products such
as acetic acid. The survey data are shown in the following
tabulation:
Plant_l
Flow 1,600 gallons/1,000 Ib
COD 186 mg/1
2.48 lb/1,000 Ib
BODS 84 mg/1
1.12 lb/1,000 Ib
TOC N.A.
Plant_2
140 gallons/1,000 Ib
N.A.
N.A.
N.A.
14,400 mg/1
16.7 lb/1,000 Ib
Although direct comparison of COD, BOD5., or TOC values between
two plants was not possible, the magnitude of the above
parameters and the general relations between COD and TOC, and
between BOD5 and TOC, show a significant difference in RWL for
the two plants. The difference is attributed mainly to differing
efficiencies of acetaldehyde flash columns and ethanol recovery
stills. By improving operating conditions of those stills, Plant
2 should be able to reduce its RWL to the representative RWL of
Plant 1.
BADCT and BATEA control technology are defined by an in-process
modification of the water scrubbing system, entailing division of
the scrubber into a fresh-water scrubbing portion and a bulk
recycle water portion. Such a division can significantly reduce
fresh-water usage by permitting recycle of four-fifths of the
existing waste stream. The amount of waste water flow from the
scrubber is thus one-fifth of the original flow. However,
because the concentrations of contaminants in this waste stream
will increase proportionally, no reduction in RWL will occur.
Total process water and cooling water usages of the two plants
are summarized as follows:
Plant
Plant 1
Plant 2
Process Water
Ib/lb product
13
1
Cooling Water
Ib/lb product
104
100
Process water is applied mainly to the scrubber. The more water
used, the larger the amount of waste flow.
Acetaldehyde capacity in the U.S. is presented in Table IV-16.
114
-------
Acetaldehyde capacity in the U.S. is presented in Table IV-16.
Table IV-16
Acetaldehyde Capacity
(MM Ib )
Company
1972
Process
Celanese
Commercial Solvents
Dupont Company
Eastman
Goodrich
Hercules
Monsanto
Publicker
Shell
Union Carbide
Bay City, Texas
Bishop, Texas
Clear Lake, Texas
Pampa, Texas
Agnew, Calif.
Loui sviIle, Ky.
Kingsport, Tenn.
Longview, Texas
Calvert City, Ky.
Parlin, N. J.
Texas City, Texas
Philadelphia, Penn.
Norco, La,
Institute, W. Va.
S. Charleston, W. Va.
Texas City, Texas
Totals
210
200
175
10
1
10
200
250
1
35
5
80
5
210
200
375
10
1
10
-
500
1
-
5
80
5
Ethy lene
LP-gas
Ethy lene
Byproduct
petroleum gas
Ethanol
Byproduct
petroleum gas
Ethanol
Ethy lene
Byproduct
petroleum gas
Ethanol
Byproduct
petroleum gas
Ethanol
Byproduct
650
650
petroleum gas
Ethanol
1,832 2,0^7
115
-------
SUBCATEGORY B
Product
Acetylene Partial Oxidation of Methane
Acetylene is manufactured by burning preheated natural gas and
pure oxygen in specially designed burners. The natural gas is
partially oxidized with oxygen, and the evolved heat cracks the
hydrocarbon to acetylene.
CH4 + 202 ""* C02 + 2H20
Methane Oxygen Carbon Dioxide Steam
2CH4 _* C2H2 + 3H2
Methane Acetylene Hydrogen
Cracking occurs at 1,500°C with a residence time of 0.01 to 0.1
seconds. The resulting gases are rapidly quenched with water to
prevent acetylene decomposition. A gas cooler and a series of
distillation columns are then used to separate acetylene from by-
products.
Large quantities of carbon (coke) are produced by burning of the
natural gas, and these fine particles are trapped in the quench
stream. An air flotation unit or similar device must be provided
to remove coke from the quench water before the water can be sent
to a cooling tower and recycled. The solids removed can be
dewatered and disposed of by incineration. The only waste water
stream from the process results from the cooling water system,
which must be continually bled and replenished with fresh water
to avoid build-up of dissolved substances.
A flow sheet of this process is shown in Figure IV-12.
The results of survey data on cooling tower draw-off stream are
shown in the following tabulation:
Flow 561 gallons/1,000 Ib
COD 1,27U mg/1
5.95 lb/1,000 Ib
BOD5 410 mg/1
1.92 lb/1,000 Ib
TOC 393 mg/1
1.80 lb/1,000 Ib
116
-------
FIGURE IV-12
ACETYLENE
NATURAL GAS
OXYGEN
PRODUCT ACETYLENE
INCINERATION
| COLD QUENCH WATER
/7
"COOLING^
TOWER j
i i
DRAW-OFF
-------
Comparing these data with those for the cooling water just prior
to being discharged to the cooling tower inlet indicates that a
significant amount of hydrocarbons are evaporated into
atmosphere. In order to further reduce the RWL and not sacrifice
ambient air quality, a steam stripper can be installed to remove
hydrocarbons from the waste stream before the waste water is sent
to the cooling tower. The collected hydrocarbons can then be
disposed of by incineration. RWL of BADCT and BATEA will require
this in-process modification to achieve lower waste loads.
Acetylene can also be produced by two other routes. The first is
pyrolysis of a mixture of lime and coke at 2,000°C in an electric
furnace to form calcium carbide. The calcium carbide is ground
under anhydrous conditions and then treated with a limited
quantity of water to produce acetylene. Calcium hydroxide is a
by-productc. The second, called the Wulff Process, produces
acetylene by pyrolysis of ethane, propane, naphtha, or similar
material. An alternating cycle is used wherein hydrocarbons are
heated by a hot tile checker work (1,100°C) to produce acetylene.
Following this, there is a combustion step during which the
bricks are heated in air to burn off tar deposits. The pyrolysis
gases are contacted initially with dimethyl formamide (DMF) to
remove water, diacetylene, and other products. This is followed
by absorption of the acetylene in DMF and final recovery of the
acetylene by stripping.
Acetylene production had grown 10S& annually from 1960 to 1965.
This growth has been stimulated primarily by demand for vinyl
chloride, vinyl acetate, and chloroprene. However, acetylene
demand has exhibited a marked decline since then. 1972 acetylene
capacity in U.S. is presented in Table IV-17.
Table IV-17
U.S. Acetylene Capacity (1972)
Company
Diamond Shamrock (Houston, Texas)
Dow (Freeport, Texas)
Monochem (Geismar, La.)
Rohm and Haas (Houston, Texas)
Tenneco (Houston, Texas)
Union Carbide (Seadrfft, Texas)
(Taft, La.)
(Texas City, Texas)
Other
Total
MM lb
40
15
165
35
100
15
18
80
—Z35.
1,203
Source: ON. Paint & Drug Reporter. April 5, 1971,
Process
Partial oxidation
11
11
Ethylene byproduct
Wulff
Pa rial oxidation
Calcium carbide
P. 9.
118
-------
SUBCATEGORY B
Product
Ethylene Oxide
Process
Catalytic Oxidation of Ethylene
Most ethylene oxide manufacture is based on the direct
phase oxidation of ethylene over a silver oxide catalyst:
vapor-
C2H4
1/2 02
Ethylene Oxygen
H2COCH2
Ethylene Oxide
Oxidation takes place in the main reactor. Partial oxidation of
ethylene to ethylene oxide and total oxidation to carbon dioxide
and water are the two primary reactions. Ethylene oxide is
recovered from the reactor effluent by absorption in a dilute
aqueous solution.
A flow sheet for the oxidation process is shown in Figure IV-13.
In the process using high purity oxygen, the main absorber off-
gas passes through a carbon dioxide removal system and is
recycled to the reactor to reduce the ethylene partial pressure.
When air is used as the oxidant, a secondary reactor system is
employed to scavenge the remaining ethylene in the main absorber
off-gas. Ethylene oxide is separated from water in the desorber,
and the residual gases are discharged from the system. The
combined liquid stream is fed to the ethylene oxide still, where
the oxide product and residual water are separated.
The only waste stream generated in the direct oxidation process
is the draw-off from the ethylene oxide separator bottoms.
Process raw waste loads of this process obtained from plant
visits are shown in the following tabulation:
Plant 1
Flow
COD
BOD5
TOC
Plant_2
17.8 gallons/1,000 Ib 131.a gallons/1,000 Ib
52,000 mg/1
7.7 lb/1,000 Ib
4,800 mg/1
0.71 lb/1,000 Ib
19,650 mg/1
2.91 lb/1,000 Ib
4,800 mg/1
5.26 lb/1,000 Ib
650 mg/1
0.71 lb/1,000 Ib
2,699 mg/1
2.95 lb/1,000 Ib
The survey data show the same order of magnitude of raw waste
loads in these two plants. However, the Plant 1 ethylene oxide
separator operates more effectively and, consequently, generates
a lesser volume of wastewater. Further reduction of RWL of Plant
1 is deemed unfeasible, and it should be considered as a
representative RWL of this process in BPCTCA standards.
119
-------
FIGURE IV-13
ETHYLENE OXIDE
LIGHT ENDS
ETHYLENE
02, AIR_
ETHYLENE OXIDE
ABSQR
1
BER
*-
i
1
DESORBER
i
STEAM
NaOH
H20
WASTEWATER
HEAVY ENDS
-------
Ethylene oxide manufacture is usually accompanied by ethylene
glycol manufacture. Since the waste water from ethylene oxide
contains 2% or more of ethylene glycol, this waste stream is
usually sent to an ethylene glycol plant for further processing
instead of being discharged into sewer lines. BADCT and BATEA
standards, therefore, should require zero discharge from the
direct oxidation process.
The high sulfate concentration in waste streams would disrupt the
normal operation of biological treatment systems. Therefore,
pretreatment or proper dilution with other waste streams is
required.
Total process water usage (including steam directly supplied to
the process) of this manufacturing process is approximately 0.25
Ib water per Ib of ethylene oxide, while cooling water usage is
0.096 Ib water per Ib of ethylene oxide.
An alternate route in the manufacture of ethylene oxide (used
only by one chemical plant) is the chlorohydrin process.
Ethylene, chlorine, and water are passed into a packed reactor,
where they form ethylene chlorohydrin. The ethylene chlorohydrin
is then reacted with hydrated lime to produce ethylene oxide.
This process produces an aqueous lime slurry. The generation of
this minimum-value by-product has led some producers to phase
this process out.
Ethylene oxide production has grown nearly threefold in the last
decade. Accompanying this growth has been a continuous increase
in plant size, which has led to a corresponding decline in sales
price. The U.S. ethylene oxide capacity and estimated economics
for ethylene oxide are shown in Tables IV-18 and IV-19.
121
-------
Table IV-18
Ethylene Oxide Capacity
(MM Ib)
Company
Calcasieu Chemical
Celanese
Dow
Eastman
GAP
Houston Chemical
Jefferson Chemical
Matador Chemical
Northern Natural Gas
01 in Mathieson
Shell
Sun 01 in
Union Carbide
Loca t i on
Lake Charles, La.
Clear Lake, Texas
Freeport, Texas
Placequemine, La.
Long view, Texas
Linden, N.J.
Beaumont, Texas
Port Neches, Texas
Orange, Texas
Jol iet, 1 1 linois
Brandenberg, Ky.
Geismar, La.
Claymont, Del.
Institute, W.Va.
Seadrift, Texas
S. Charleston, W.Va.
Texas City, Texas
Tor ranee, Calif.
Whiting, Ind.
Ponce, P.R.
Taft, La.
1970
150
300
425
150
60
65
80
500
45
240
100
125
80
220
330
60
700
50
150
100
350
1972
150
300
425
150
60
-
80
500
45
240
100
125
80
220
430
60
500
50
150
100
450
TOTAL
1
4,280 4,215
One unit shut down at this site.
Source: Oil. Paint & Drug Reporter. Oct. 1, 1969.
122
-------
Table IV-19
Estimated Ethylene Oxide Economics
(300-MM-lb plant; 1972 construction)
Total Fixed Investment Cost
_. Process $ MM
Chlorohydrin 15.20
Catalytic air oxidation 38.60
Estimated Operation Cost
Cost
Raw materials
Utilities
Labor
Maintenance (6% ISBL + 3% OSBL)
Overhead (45% maint. + labor)
Taxes & insurance (1.5% of invest.)
Depreciation (10 years)
TOTAL
e/lb ethylene
Chlorohydrin Ai
9.611
0.78
0.20
0.2k
0.20
0.08
0.50
11.61
oxide
r Oxidation
3.302
0.28
0.14
0.64
0.35
0.20
1.32
6.23
1Ethylene at 0.75 lb/lb and 3.3e/1b; and chlorine at 1.8 Ib/lb
and 3.250/lb.
2Ethylene at 1.0 lb/lb and 3.3
-------
SUBCATEGORY B
Product; Process
Formaldehyde Oxidation of Methanol
In the plant visited, formaldehyde is manufactured by oxidation
of methanol. The process is a gas-phase reaction, operated with
an iron-molybdenum oxide catalyst and a lean methanol-air
mixture. The chemical reaction is given below:
CH3OH + 1/2 02 HCHO + H20
Methanol Oxygen Formaldehyde Water
A flow sheet for the methanol oxidation process is shown in
Figure IV-14. A mixture of methanol and water is vaporized by a
closed steam loop, which circulates between the reactor and feed
vaporizer. The reactants, mixed with air, flow through a thin
layer of catalyst crystals in the reactor. The product gases are
cooled by water, and product formaldehyde is recovered as a 50-52
percent aqueous solution by two-stage absorption. Product
concentration is adjusted by controlling the amount of water sup-
plied to the second stage absorber. The remaining unabsorbed
gases from the absorber are disposed of by incineration.
A portion of the formaldehyde product may be passed through an
anion exchanger to produce high purity formaldehyde by removing
formic acid and sodium formate.
Waste water streams generated in this process are intermittent.
For example, waste water from the washing of the absorber occurs
at most twice per year. The contaminants in this stream are
formic acid, methanol, formaldejiyde, and ammonia. Wastewater
created by regenerating the ion exchange units occurs three times
per month at the plant visited. Another possible waste stream is
withdrawn as an aqueous slip stream from the bottom of the feed
vaporizer whenever heavy impurities (such as acetone and
oxygenated organics) occur in the methanol feed; the total flow
of this waste stream, estimated by plant personnel, is about 131
gallons per 1,000 pounds of formaldehyde. A sample was not taken
for analysis, since a continuous and representative sample is not
available.
The alternate approach for formaldehyde manufacture from methanol
involves a combined dehydrogenation and oxidation reaction over a
silver or copper catalyst. This process operates with a rich
methanol-air mixture.
About 90 percent of the formaldehyde produced in the U.S. is
based on methanol as a raw material. The balance of the
formaldehyde production is as a co-product of butane oxidation.
The basic chemical reaction is summarized as follows:
124
-------
FIGURE IV- 14
FORMALDEHYDE, METHANOL OXIDATION
to
Ln
METHANOL & WATER
AIR
VAPORIZER
STEAM
CATALYST
REACTOR
ABSORBER
CONDENSATE
DRAW OFF OF HEAVY
FEED IMPURITIES
ABSORBER
,OFF GAS (INCINERATION)
• WATER
-INTERNAL WATER
RECYCLE LOOP
-> INTERMITTENT REACTOR WASH WATER
ION EXCHANGE
WASTEWATER
FORMALDEHYDE
WATER
-------
2C3H8 + 2C4HJO + 902 * 14HCHO + UH2O
Propane Butane Oxygen Formaldehyde Water
The U.S. formaldehyde capacity and the estimated economics for
formaldehyde production of a 100 million pounds per year (100
percent) unit based on iron-molybdenum catalyst process are shown
in Tables IV-20 and IV-21.
126
-------
Producer
Allied
American Petrofina
Borden
Celanese
Commercial Solvents
DuPont
GAP
Georgia Pacific
Gulf
Hercules
Monsanto
Table IV-20
U. S. Formaldehyde Capacity
Plant Location
Ironton, Ohio
Calumet City, 111.
Bainbridge, N. Y.
Demopolis, Ala.
D ibolI, Texas
Fayettevilie, N. C.
Fremont, Calif.
Kent, Washington
La Grande, Oregon
Loui sviIle, Ky.
Missoula, Mont.
Sheboygan,Wi sc.
Springfield, Oregon
Bishop, Texas
Newark, N. J.
Rock Hill, S. C.
Agnew, Calif.
Seiple, Pa.
Ster1i ng, La.
Belle, W. Va.
LaPorte, Texas
Perth Amboy, N. J.
Toledo, Ohio
Calvert City, Ky.
Coos Bay, Ore.
Columbus, Ohio
Crosett, Ark.
Vicksburg, Miss.
Hercules, Calif.
Louisiana, Mo.
Addyston, Ohio
Eugene, Ore.
Springfield, Mass.
Estimated Capacity"
(MM Ibs. 37% Soln./Yr.)
310
75
40
80
70
200
80
70
4o
70
80
120
250
1,170
115
115
30
65
30
490
200
150
150
100
80
100
160
95
170
100
100
280
127
-------
Producer
Occidental
Reichhold
Rohm and Haas
S ke11 y
Tenneco
U.C.C.
Wright
Table IV-20
(con't)
Plant Location
N. Tonawanda, N. Y,
Charlotte, N. C.
Hampton, S. C.
Kansas City, Kan.
Moncure, N. C.
Racoma, Wash.
Tuscaloosa, Ala.
White City, Ore.
Bristol, Pa.
Philadelphia, Pa.
Springfield, Ore.
Fords, N. J.
Garfield, N. J.
Boundbrook, N. J.
Acme, N. C.
Malvern, Ark.
Estimated Capacity*
(MM Ibs. 37% Soln. /Yr.)
135
10
40
ko
100
ko
70
50
25
25
70
160
175
150
150
100
TOTAL
6.570
Capacity data are as reported by Stanford Research Institute,
C.E.H. for late 1970
128
-------
Table IV-21
Estimated Economics for Formaldehyde Production
(100 MM Ib. 100% Formaldehyde Plant)
Total Fixed Capital=$0.45 MM
Estimated Operation Cost
Methanol
Catalyst and Chemicals
Utilities (including demineralized
process water)
Labor and overhead
Capital charges
TOTAL
Captive
methanol
(j.OC/lb.)
3.5
0.3
0.8
6.5
Merchant
methanol
5.2
0.3
O.k
0.8
1.5
8.2
129
-------
SUBCATEGORY B
Product Process
Ethylene Bichloride Direct Chlorination of Ethylene
The direct chlorination of ethylene is carried out in the presence of a
ferric chloride catalyst suspended in liquid ethylene dichloride.
C2H4 + C12 —* C1CH2 CHC1
Ethylene Chlorine Ethylene Dichloride
The gas stream from the reactor is passed through a caustic
scrubber, where the unreacted gases and a trace amount of
hydrogen chloride are removed by a caustic solution. The liquid
stream from the reactor is first sent to a distillation column to
remove heavy ends and then to a wash tower, where a caustic
solution is used to remove some impurities. The crude product is
finally discharged to a distillation column for purification. A
process flow sheet is shown in Figure IV-15.
There are two waste streams in this process. One is liquid
effluent from the scrubber and the other is the waste water from
the wash tower. The results of a survey at one plant are shown
in the following tabulation:
Flow 96 gallons/1,000 Ib
COD 6,050 mg/1
4.84 lb/1,000 Ib
BODJ3 Inhibitory
TOG 1,106 mg/1 ;
0.89 lb/1,000 Ib
A surface heat exchanger can be used to condense water vapor in
the offgas to the scrubber, while the remaining uncondensed gas
from the reactor (which contains primarily unreacte'd ethylene and
chlorine) can be totally recycled to the reactor. The scrubber
and its waste water can then be eliminated. With this
modification, RWL of BADCT and BATEA for this.process can be
expected to have low values of 0.072 pounds of COD and 0.106
pounds of TOC per 1,000 pounds of ethylene dichloride.
Total process water usage of this process is 0.82 pound of water
per pound of ethylene dichloride, and cooling water usage is 93
pounds of water per pound of product.
An alternate route in manufacturing EDC is oxychlorination of
ethylene with hydrochloric acid and air over a supported copper
chloride catalyst. The characteristic waste water stream from
130
-------
FIGURE IV-15
ETHYLENE DICHLORIDE (EDC) BY OXYCHLORINATION AND DIRECT CHLORINATION
VENT
DILUTE NaOH SOLUTION
ETHYLENE
WATER »
IIP 1 . h
AIR
M p „
OXYC
DIRE
^
^
QC
O
1 —
CO
LU
Q=
Q£
S
GO
&
CO
CO
T
WASTEWAT
HLORINATION
CT CLORINATION yENT
OC
C3
t—
CO
^
LU
QC
SCRUBBER
J
ER
\
i
DILUTE
NaOH
J SOLUTION
k-
LIG
r CRUDE EDC^
> >
HT ENDS
_J
1 —
CO
1
-*
HE
, .. w
|
_l
_1
te
1
AVY ENDS
EDC
WASTEWATER
-------
this process will contain most of the same impurities found in
the direct chlorination process.
Ethylene dichloride has moved from fifth to third place in
consumption of ethylene in the last decade. This growth has been
at the expense of acetylene. The common point of intersection is
vinyl chloride, which accounts for 15% of ethylene dichloride
usage. Ethylene dichloride production has grown more than four-
fold since 1961 with a concomitant decline in price to about 32
per pound. The U.S. ethylene dichloride capacity and estimated
economics of EDC are presented in Tables IV-22 and IV-23,
respectively.
132
-------
Table IV-22
U.S. Ethylene Dichloride Capacity (1972)
Company
Allied
American Chemical
Continental Oil
Diamond Shamrock
Dow
Ethyl Corp.
B.F. Goodrich
PPG
Shell
Union Carbide
Vulcan
(Baton Rouge, La.)
(Long Beach, Calif.)
(Lake Charles, La.)
(Deer Park, Texas)
(Freeport, Texas)
(Plaquemine, La.)
(Baton Rouge, La.)
(Houston, Texas)
(Calvert City, Ky.)
(Lake Charles, La.)
(Guayanilla, P.R.)
(Deer Park, Texas)
(S. Charleston, W. Va.)
(Texa s City, Texa s)
(Geismar, La.)
,100
Total
Source: Oil. Paint, and Drug Reporter. Sept. 20, 1971
Table IV-23
Estimated Economics for Ethylene Dichloride
(100. MM Ib. plant)
Total Fixed Capital=$1.0 MM
Estimated Operation Cost
Cost.
Ethylene
Chlorine
Uti1ities
Labor and overhead
Capital charges
Total
C/lb. EDC
1.2
1.8
0.1
0.1
0,2
133
-------
CATEGORY-!
Product Process
Vinyl Chloride Cracking of Ethylene pichloride
Recent developments in ethylene technology, coupled with the low
cost and ready availability of ethylene, dictate ethylene as
feedstock in all new vinyl chloride plants. Vinyl chloride
monomer is produced by cracking purified Ethylene Dichloride
(EDC) in a pyrolysis furnace as follows:
C2H4C12 t C2H3C1 + HCl
EDC Vinyl Chloride Hydrochloric Acid
After quenching by direct contact coo-ling, the furnace products
are separated into HCl and high-purity vinyl chloride monomer.
The liquid streams from the quencher are fractionated to separate
the vinyl chloride product from unreacted EDC, which is then
recycled. A flow sheet for this process is shown in Figure IV-
16.
The major waste water sources are the effluents from scrubbing
systems required for hydrogen chloride removal, recycle
purification of EDC, and the effluent from associated aqueous
acid by-product production units. The survey data for one plant
are presented in the following tabulation.
FLOW 336 gallons/1,000 Ib
COD 2,733 mg/1
7.661 lb/1,000 Ib
BOD5 Not available
TOC 120 mg/1
0.33 lb/1,000 Ib
A large fraction of the RWL shown above is contributed by the
aqueous acid production unit. If the by-product were left in an
anhydrous form, the anhydrous acid by-product could actually re-
place the aqueous acid by-product. The RWL of this process will
be reduced to 85 gallons of flow per 1,000 Ib of product, 0.203
Ib COD/1,000 Ib, and 0.054 Ib TOC/1,000 Ib; this level of RWL
will be considered as the standard of BADCT and BATEA control
technology for vinyl chloride manufactured by EDC cracking.
Total process water usage in existing processes is 2.80 pounds
per pound of vinyl chloride, and cooling water usage amounts to
3,464 pounds per pound of product.
134
-------
FIGURE IV-16
VINYL CHLORIDE BY THERMAL CRACKING OF ETHYLENE DICHLORIDE
HCI RECYCLE
ETHYLENE
DICHLORIDE
*• VINYL
CHLORIDE
HEAVY ENDS
-------
An alternate route in manufacturing of vinyl chloride is the
classical acetylene addition reaction. This has been covered
under the discussion in Category A.
Table IV-24 presents the \3»S. vinyl chloride capacity, and
IV-25 estimated economics for various processes.
Table
Company
Allied Chemical (Moundsvi1le, W.
(Geismar, La.)
American Chemical (Long Beach, Calif.)
Continental Oil (Lake Charles, La.)
Cumberland Chemical (Calvert City, Ky.)
Diamond Shamrock (Deer Park, Tx.)
Dow Chemical (Freeport, Tx.)
(Plaquemine, La.)
Ethyl Corp. (Baton Rouge, La.)
(Houston, Tx.)
General Tire (Ashtabula, Ohio)
B. F. Goodrich (Calvert City, Ky.
(Niagara FalIs, N.
Goodyear (Niagara Falls, N.Y.)
La.)
La.)
Rico)
Tx.)
Tx.)
Charleston, W. Va.)
Table \\l-2k
U.S. Vinyl chloride capacity
(MM Ib)
Va.)
,)
.Y.!
Monochem (Geismar
PPG (Lake Charles
PPG-Corco (Puerto
Shel1 (Deer Park,
Tenneco (Houston,
Union Carbide (S.
Totals
(Texas City, Tx.)
1967
100
-
170
-
60
100
200
250
270
150
75
4oo
40
70
250
_
200
120
230
2,685
1969
_
300
170
600
-
100
200
300
270
150
-
400
-
-
250
300
200
120
230
3,590
1972
550
170
600
525
575
270
150
400
250
300
500
700
200
120
5,310
Process
Acetylene
Ethylene
Ethylene
Ethylene
Acetylene
Acetylene
Ethylene
Ethylene
Ethylene
Ethylene
Acetylene
Ethylene
Acetylene
Acetylene
Acetylene
Ethylene
Ethylene
Ethylene
Acetylene
Ethylene &
Acetylene
1
Based on Oil. Paint & Drug Reporter. March 17, 1969.
136
-------
Table IV-25
Estimated vinyl chloride economics
(500-MM-lb plant; 1972 construction)
Total fixed capital
Process
Acetylene
Ethane (transcat)
$ MM
Raw materials
Ethane (0.59 lb/lb at 0.9<£/lb)
Ethylene (0.49 lb/lb at 3.0i/lb)
Chlorine (0.6? lb/lb at 2.5«/lb)
Acetylene (0.44 lb/lb at S.Ot/lb)
HCI (0.60 lb/lb at 2.5C/lb)
Subtotal
Labor
Utilities
Maintenance (6% ISBL + 3% OSBL)
Overhead (45% maint. + labor)
Taxes £• ins. (1.5% of investment)
Depreciation (10 years)
Total
orinat ion
:t)
Product
Process:
•)
ion cost
Ethylene
1.46
1.68
-
-
3.14
0.09
0.22
0.17
0.12
0.05
0.36
4.15
17.9
18.9
18.0
C/lb
Acetylene
:
3.52
1.49
5.01
0.06
0.08
0.18
0.11
0.06
0.38
5.88
Ethane
0.53
1.4V
-
-
1.98
0.09
0.22
0.17
0.12
0.05
0.36
2.99
1
0.58 lb/lb at 2.5c/lb.
137
-------
SUBCATEGORY B
Product
Styrene
Process
Dehydrogenation of Ethyl Benzene
Styrene is produced by vapor-phase dehydrogenation of ethyl
benzene over supported zinc oxide, magnesium oxide, and iron
oxide catalysts. Steam is used as the diluent.
C6H5 C2H5-*C6H5 C2H3
Ethyl Benzene
Styrene
H2
Hydrogen
A flow sheet for Styrene via the dehydrogenation of ethyl benzene
is shown in Figure IV-17. Feedstock ethyl benzene and
superheated steam are mixed in a dehydrogenation reactor. After
being condensed, the reactor effluent goes to a separator, where
three phases are formed. The uncondensed gases are passed
through a scrubber where organic vapors are removed by the
scrubbing water. The water phase is removed from the separator
and discharged from the system, and the organic dehydrogenated
mixture passes to the distillation section.
Since the dehydrogenation reaction operates at about 60% ethyl
benzeneconversion, it is necessary to fractionate the process
unreacted ethyl benzene for recycle. Styrene will polymerize at
temperatures approaching its normal boiling point; therefore, it
is necessary to operate the styrene ethyl benzene distillation
under vacuum to prevent styrene loss due to polymerization.
The draw-offs from separator and scrubber are two of the three
major waste water pollution sources in the process. The other
source is a steam-ejector system used to produce vacuums for
distillation columns. The survey data derived from plant visits
are summarized as follows:
Plant_l
Flow 2,810 gallons/1,000 Ib
COD 219 mg/1
5.13 lb/1,000 Ib
BODS 69 mg/1
1.62 lb/1,000 Ib
TOC 22 mg/1
0.53 lb/1,000 Ib
Plant_2
657 gallons/1,000 Ib
426 mg/1
2.34 lb/1,000 Ib
70 mg/1
0.381 lb/1,000 Ib
22 mg/1
0.12 lb/1,000 Ib
138
-------
FIGURE IV-17
STYRENE, DEHYDROGENATION OF ETHYL BENZENE
STEAM
FEEDSTOCK
ETHYL BENZENE
REACTOR
SUPER HEAT
HEAT
EXCHANGER
BENZENE
TOLUENE
DISTILL
COL.
DISTILL
COL.
c.w.
DECANT
DRUM
TO FULE
•H20
SCRUBBER
API
SEPARATOR
c.w.
VAC.
ni STILL
RECYCLE
ETHYL BENZENE
STEAM JET
WASTEWATER
WASTEHATER
STYRENE
YAC.
DISTILL
WASTEWATER
TO INCINERATION
-------
The smaller amount of waste water in Plant 2 is attributed to its
use of steam jets with surface heat exchangers in contrast to the
steam jets with barometric condensers used in Plant 1, and also
to effective operation of the scrubber system. Use of untreated
river water as quenching water for the barometric condensers at
Plant 1 introduces some contaminants into the waste water stream.
Plant 2 discharges uncondensible vapors (consisting of some
organic contaminants) from surface heat exchangers into the
atmosphere.
To achieve BADCT and BATEA control technology, the steam jets
(with either surface or barometric condensers) should be replaced
by vacuum pumps. RWL for BADCT and BATEA can then be expected to
be lower than that represented by Plant 2.
An example based on a 5 x 108 Ib per year styrene plant has been
devised for illustrating the advantages of vacuum pumps over
steam jets. A description is given in the following paragraphs.
A two-stage steam ejector system is currently used to obtain the
vacuum in the distillation section. The ejector system
illustrated uses surface exchangers for both inter and after
condensers. A schematic flow sheet, depicting steam and effluent
flow rates and effluent composition, is presented in Figure IV-
18. The effluent steam from the ejectors contains a fair amount
of organics and represents a source of pollution. The cost of
operating the two-stage ejector system is presented in Table IV-
26. Some producers reportedly fractionate the ejector effluent
srream and recycle the organics back to the process. However, it
is not known if this technique is widespread or successful. Note
that the use of barometric condensers will result in an
excessively large effluent stream.
The vacuum pump most suitable for this application is a two-stage
unit which uses a rotating mass of liquid to draw the vacuum. In
this case, the compressant liquid would be essentially ethyl
benzene. Most of the organics in the inlet vapor stream from the
tower condense in the compressant fluid and can be recycled back
to the process. Process flow sheets showing the use of vacuum
pumps are presented in Figure IV-19. The amount of organic
substances actually leaving the vacuum system in the exhaust air
is extremely small and is itemized in Table IV-27. The amount
shown in this table as recycled is actually discharged from the
system via the steam ejector system. The operating costs of
using vacuum pumps are summarized in Table IV-28.
It is evident that a two-stage, liquid-sealed vacuum pump is more
economical than a two-stage steam ejector using surface
condensers. The economic advantage is due to the extremely low
loss of ethyl benzene and styrene in the exhaust stream from the
vacuum pumps. In ether words, this modification not only has an
aconomic advantage, but also reduces the RWL of the process.
Styrene is used exclusively for homo-, co-, and terpolymers and
is produced on the Gulf Coast. Production capacity has grown
rapidly to accommodate demand. Installed styrene capacity is
140
-------
FIGURE IV- is
STYRENE- ETHYLBENZENE DISTILLATION, VACUUM VIA TWO-STAGE STEAM .EJECTORS
LBS/HR.
COOLING WATER RETURN 105"F
COOLING WATER SUPPLY 85°F
PRODUCT STYRENE
0.2 WT.% ETHYLBENZENE
O TEMPERATURE, C
DPRESSURE, MM Hg ABS
-------
FIGURE IV-19
STYRENE - ETHYLBENZENE DISTILLATION, VACUUM VIA VACUUM PUMPS
FEED
c.w.
VACUUM
PUMP
* 1 STEAM
SEPARATOR
LIQUID COOLER
RECYCLE TO PROCESS (ETHYLBEKZENE)
•NONCONDENSIBLES
NONCONDENSIBLES
-*• ETHYLBENZENE RECYCLE
VACUUM
PUMP
*| STEAM
SEPARATOR
LIQUID COOLER
»
C.W.
1
RECYCLE TO
PROCESS
(ETHYLBENZENE)
PRODUCT STYRENE
-------
Table IV-26
Operating Cost of Two-Stage Steam Ejectors
Styrene-Ethyl Benzene Distillation
500 MM Ibs/yr Styrene, 8,200 hrs/yr
Two-Tower System
Investment, $ (for ejectors etc.)
Ut.i 1 ities
Steam, x 55C/M Ib
Cooling Water, 2.5e/M gal
AT=20°F
Total Utilities, $/Yr
Investment Related
Maintenance Material and Labor,
2% of Investment
Plant Overhead, 65% of Maintenance
Insurance and Taxes, 1.5% of
Investment
Depreciation, 10% of Investment
Total Investment Related Expenses, $/Yr.
Product Losses
Styrene, 7.0
Ethylbenzene, 3.5
Total Product Losses, $/Yr
Total Operating Costs, $/Yr
Tower No. 1
10,000
Lb/Hr $/Yr
1,330 6,000
GPM $/Yr
150 1.800
7,800
$/Yr
200
130
150
1,000
1,480
Lb/Hr $/Yr
13 7,500
340 97.600
105,100
114.380
Tower No. 2
7,^00
Lb/Hr $/Yr
790 3,600
GPM $/Yr
89 1.100
4,700
$/Yr
150
100
110
740
1,100
Lb/Hr $/Yr
95 54,500
41 11.800
66,300
72.100
186,480
Total Operating Costs, £/lb Styrene produced
0.037
143
-------
Table IV-27
Organ!cs in Exhaust Air From Vacuum Pumps
500 MM Lbs/yr Styrene-8,200 hrs/yr
(Ibs/hr)
Two-Tower System
Tower No. 1 Tower No. 2
Styrene
In 13 95
Out In Exhaust _8 J±
Amount Recycled 5 91
Ethylbenzene
In 3^0 41
Out In Exhaust 11 _5
Amount Recycled 329 36
144
-------
Table IV-28
Operating Costs For Vacuum Pumps*
Styrene-Ethyl Benzene Fractionation
500 MM Lbs/yr Styrene, 8,200 hrs/yr.
Two Tower System
Tower
Investment, $ (vacuum pumps etc.)
Utilities
Power, 0.800 e/kwh
Cooling Water, 2.5 C/Mgal
AT=20°F.
Total Utilities, $/yr
Investment Related Expenses
Maintenance Materials and Labor,
4% of Investment
Plant Overhead, 65% of Maintenance
Insurance, Taxes, 1.5% of Investment
Depreciation, 10% of Investment
Total Investment Related Expenses, $/yr
Product Losses
Styrene, 7C/1b.
Ethylbenzene, 3.5
-------
presented in Table IV-29, and estimated economics
competitive 5 x 10« Ib plant are shown in Tatole IV-30.
for
Amoco
Cosden
Cos-Mar
Dow
El Paso
Foster-Grant
Gulf Oil
Ma rbon
Monsanto
Shell
Sinclai r-Koppers
Sun Oil ,
Union Carbide
Table IV-29
U.S. Styrene Capacity
(MM Ib)
Company
(Texas City, Texas)
(Big Spring, Texas)
(Carville, La.)
(Freeport, Texas)
(Midland, Mich.)
(Odessa, Texas)
(Baton Rouge, La.)
(Donaldsvi1le, La.)
(Baytown, Texas)
(Texas City, Texas)
(Torranee, Calif.)
(Houston, Texas)
(Kobuta, Pa.)
(Corpus Christ!, Texas)
(Sea Drift, Texas)
(Institute, W. Va.)
19671
1970'
1972
Total
300
100
-
500
300
85
200
-
125
650
210
70
200
60
300
110
3,210
800
100
500
650
350
120
250
-
135
800
2kO
110
1*30
80
300
shut down
^, 865
800
100
500
650
350
120
250
500
shut down
i,3o
-------
Table IV-30
Estimated Economics For Styrene
(500 MM-lb plant; 1972 construction period)
A. Total fixed capital=$35.0 MM
B. Production costs
styrene
2
Raw materials 3.95
Labor 0.13
Utilities 0.91
Maintenance 0.3^
(6% ISBL + 3% OSBL)
Overhead
(45% maint + labor)
Taxes
(1.5% of invest)
Depreciation (10 yr)
Total
_Dehydrogenation process.
1.10 Ib ethybenzene at 3.50tf/lb + catalyst and chemicals.
147
-------
SUBCATEGQRY B
Process
Methyl Amines Synthesis of Methanol and Ammonia
Methyl amines are synthesized by methanol and ammonia in the
presence of catalyst to form a mixture of mono-, di-, and
trimethylamine.
CH30H + NH3 —* (CH3NH2 + H20
Methanol Ammonia Monomethylamine Water
2C30H + NH3 """* (CH3J2NH + H2O
Dimethylamine
3CH3OH + NH3 (CH3J3N + H2O
Trimethylamine
Reactants are first preheated by the converter effluent, thereby
recovering some of the exothermic reaction heat. The product
stream is then flashed to remove the noncondensibles and is sent
to the recovery system. First, ammonia is taken overhead and
recycled, together with some trimethylamine. Next, water is
added to break the TMA-Ammonia azeotrope, and pure TMA is taken
overhead from a distillation column. The mixture of mono- and
dimethylamine is first dehydrated and then fractionated to
separate DMA and MMA. The ratios of three amines can be varied
by changing reaction conditions. The process flow diagram is
shown in Figure IV-20.
This process uses water to scrub ammonia from all off-gases. The
liquid effluent from the absorber is then flashed to recover
ammonia. The major waste water source, containing a significant
amount of unrecoverable ammonia, is the bottoms from the flash
column. The other two waste water streams are the bottoms from
the separation fractionators. The characteristics of the waste
water are summarized in the following tabulation.
Sample No. 1 Sample No. 2
Flow 429 gallons/1,000 Ib 429 gallons/1,000 Ib
COD 6,303 mg/1 1,178 mg/1
22.56 lb/1,000 Ib 4.21 lb/1,000 Ib
BODS 99 mg/1 174 mg/1
0.351 lb/1,000 Ib 0.62 lb/1,000 Ib
TOC 11,634 mg/1 3,808 mg/1
148
-------
RECYCLE
FIGURE IV-20
METHYLAMINES
METHANOL
AMMONIA
DMA
PRODUCT
STEAM WASTE
-------
U1.65 lb/1,000 Ib 13.63 lb/1,000 Ib
The above data show significant variation. The extraordinarily
high ratio of COD/BOD^ is due to the ammonia contaminant which
contributes to the measurement of COD but not to that of BOD5.
It is believed that Sample I was taken under the upset operating
condition of the ammonia flash column.
Total process water usage, including steam directly supplied to
the process, is 3.1 pounds water per pound of methylamines, while
cooling water usage amounts to 16,700 pounds water per pound of
product.
Minor process modifications such as reusing waste waters from
fractionators as ammonia absorption water can reduce the amount
of waste water. The ammonia content in the waste water can be
treated only by end-<-of-pipe treatment.
Investment for a methylamines plant depends somewhat on the
intended product mixture; a unit to produce 10 million pounds per
year costs around $1.5 million. A summary of U.S. production
capacity and estimated production costs for dimethylamine are
presented in Tables IV-31 and IV-32.
150
-------
Table IV-31
U.S. Methyl Amines Capacity (1970)
Company Locat ion Capacity
MM Ibs.
Commercial Solvents Terre Haute, Ind. 18
DuPont Belle, W. Va. 75
Strang, Texas 26
Escambia Pace, Fla. 50
GAP Calvert City, Ky. 10
Pennwalt Wyandotte, Mich. 10
TOTAL 189
Table IV-32
Estimated Economics for Methylamines
(10 MM Ib. Plant)
Total Fixed Capital =$1.5 MM
Estimated Production Cost
Cost
. DMA
Methanol (captive, 3.0Vlb.) k.6
Ammonia (merchant, 4.06/lb.) 1.6
Utilities 1.5
Labor and Overhead 1.2
Capital charges 5.0
Total 13.9
151
-------
SUBCATEGORY B
Product
Vinyl Acetate Synthesis with Ethylene and Acetic Acid
Fresh ethylene, oxygen, and acetic acid are combined with their
respecttive recycle streams, and then are vaporized and fed to a
fixed-bed reactor. Typical operating conditions are 5 psig and
250°C. Conversion per pass is about 5 percent, with very high
(99 percent) selectivity. The catalyst is usually a mixture of
palladium, copper, and iron chloride on alummina. The acetic
acid-*to-water mole ratio in the reactor is kept at about 40:1 to
suppress acetaldehyde formation. Reactor effluent vapor is
partially condensed to recover some of the acetic acid for
recycle. Further cooling and fractionation separate a crude
product stream from ethylene, which is recycled to the reactor.
The crude product stream is then fed to a series of fractionators
for further removal of acetic acid and light ends. Hydroquinone
is usually added as a polymerization inhibitor before vinyl
acetate is sent to storage. The process flow diagram is shown in
Figure IV-21.
Since the process is a vapor-phase reaction, waste water is
minimal. The major waste water stream is generated as bottoms
from one of the fractionators. The light ends and heavy ends
separated out are either recycled, sold, or disposed of by
incineration.
Results of survey data are summarized in the following
tabulation:
Flow 28 gallons/1,000 Ib
COD 516 mg/1
0.13 lb/1,000 Ib
BODS 150 mg/1
0.04 lb/1,000 Ib
TOC 220 mg/1
0.25 lb/1,000 Ib
This level of RWL can be considered as standards for BADCT and
BATEA control technology for this process.
The classical alternate route in manufacturing of vinyl acetate
is the simple vapor-phase reaction of acetylene and acetic acid
in the presence of a zinc acetate catalyst on a carbon support.
Acetylene conversion is about 60 percent per pass at high (96
percent) selectivity.
A third route is by liquid-phase synthesis if ethylene and acetic
acid. The reaction is carried out in a palladium chloride
solution at 450 psig and 250°C. Conversion per pass is about 5
percent with 97-98 percent slectivity. Acetaldehyde co-product
152
-------
FIGURE IV-21
VINYL ACETATE, FROM ETHYLENE AND ACETIC ACID
RECYCLE ACETIC ACID
LIGHT ENDS
ETHYL EN E
VINYL ACETATE
WASTEWATER
STEAM
WASTEWATER
HEAVY ENDS
-------
yield is controlled by suitable adjustment of the water content,
and this co-product is oxidized in-situ to form acetic acid,
which is used for the main reaction. The literature indicates
that this route produces the best economics.
The U.S. vinyl acetate capacity and comparative economics of the
acetylene and ethylene processes are presented in Tables IV-33
and IV-34.
Table IV-33
U.S. Vinyl Acetate Capacity
Producer
Air Products
Borden Chemical
Celanese Chemical
DuPont Company
Monsanto Company
National Starch
Union Carbide
U.S. Industrial Chemical
Total
% acetylene
Locati on
Calvert City, Texas
Geismar, La.
Geismar, La.
Bay City, Texas
Pampa, Texas
Clear Lake, Texas
Niagara Falls, N.Y.
La Porte, Texas
Texas City, Texas
Long Mott, Texas
S. Charleston, W.Va.
Texas City, Texas
La Porte, Texas
1967
MM Ib
95
90
100
65
75
65
50
55
H+5
~
71*0
78
1969
MM Ib
95
115
100
65
75
65
50
55
195
-.--,*"_
815
80
1970 '
MM Ib
95
115
75
100
200
75
80
60
55
300
300
1.1+55
59
1972
MM Ib
115
75
200
1+00
-
60
300
300
1 ,1+50
38
Process
Acetylene
Acetylene
Acetylene
Ethylene
Acetaldehyde-
acetic anhydride
Ethylene
Acetylene
Ethylene
Acetylene
Acetylene
Acetylene
Acetylene
Ethylene
Source: Oil . Paint £. Drug Reporfgr Profile, Jan. 1, 1970 and other trade publication
154
-------
Table IV-34
Comparative Vinyl Acetate Economics
(300-MM-lb plants; 1972 construction period)
Estimated Total Investment Cost
Acetylene process = $12.6 MM
Ethylene process (gas phase) = $17.3 MM
Raw materials
Acetic acid (6.0
-------
SUBCATEGORY C
Process
Phenol 1. Cumene Oxidation and Cleavage
2. Chlorobenzene Process
1. Cumene Oxidation and Cleavage
The cumene process is currently the most popular route and the
one upon which most expansions will be based. The manufacture of
phenol from cumene is carried out by a process involving the
following basic steps:
a. Oxidation of cumene with air to form cumene hydroperoxide.
C6H5CH (CH3) 2O2 —*• C6H5C (CH3)200H
Cumene Oxygen Cumene Hydroperoxide
b. cleavage of cumene hydroperoxide to form phenol and acetone.
C6H5C (CH3) 20OH —* C6H5OH + CH3 COCH3
Cumene Hydroperoxide Phenol Acetone
A process flow sheet is shown in Figure IV-22. Cumene and air
are fed to a liquid-phase reactor, operating at 25-50 psig and
130-mO°C, in the presence of a small amount of alkali, to
produce the hydroperoxide intermediate. Reactor liquid effluent
is fed to a fractionating tower, where unreacted cumene is
recovered and recycled to the reactor.
Cumene hydroperoxide from the fractionator is fed to a hydrolysis
reactor where the cumene hydroperoxide is cleaved to phenol and
acetone with the aid of a sulfuric acid catalyst. Typical
operating conditions are 5 psig and 150-200°F, and conversion is
essentially complete, with minimal formation of undesired by-
products. The crude phenol-acetone mixture if passed through an
ion exchange system and then fed to a series of tower
fractionation trains, where pure phenol and co-produced acetone
are separated from light and heavy ends and other by-products.
2. Chlorobenzene Process
The process flow diagram of chlorobenzene process is shown in
Figure IV-23, and the basic reactions are summarized below:
C6 H5C1 + 2NaOH (Excess) —* C6H5 ONa + NaCl + H2O
Chlorobenzene Sodium Hydroxide Sodium Sodium Water
Phenate Chloride
156
-------
01
BENZENE
PROPANE
PROPENE
A
ALKYLATION
REACTOR
FIGURE IV-22
PHENOL, VIA CUMENE
t
PROPANE
OXIDATION
REACTOR
CUMENE
PROPANE
COLUMN
I
BENZENE
COLUMN
CUMENE
COLUMN
I
WASTE
AIR
RECYCLE
I
VENT
d . D
TO WASTE,
CRYSTALLIZER
a-METHYLSTYRENE
HYDROGENATION
DILUTE
H2S04
TO VACUUM ,
CUMENE
COLUMN
PHENOL
COLUMN
PHENOL
I
a-METHYLSTYRENE
COLUMN
ACETONE
COLUMN
ACETOPKENONE ETC.
t
I
T
4
i
ACETONE
f
i
SEPARATOR
(
1
1
WASTE
p
\
'
h«
V*
M-,
\
j '
HYDROLYSIS
REACTOR
-------
SSI
NEUTRALIZA-I
TION
TANK
BRINE DISTIL-
LATION COLUMN
DECANT TANK
•z.
o
70
O
O w
z m
9 <
n '
I N>
i— CO
O
70
O
OB
m
Z
M
PHENOL
DISTILLATION
COLUMN
-------
C6H 50Na +HC1 •"* C6H50H + NaC1
sodium Hydrochloric Phenol sodium
Phenate Acid chloride
The feed materials (chlorobenzene and excess caustic solution)
are fed into a liquid-phase reactor, and the effluent is
discharged into a decanter. The upper layer of unreacted
chlorobenzene is recycled back to the reactor. The bottom layer
of sodium phenate is neutralised to produce a mixture of phenol
and brine; this mixture is then decanted. The upper layer is
sent to a fractionator, where pure phenol is obtained, and the
bottom brine stream is passed through an activated carbon bed to
remove the reamining phenol, which is eventually recycled back to
the reactor.
The chlorobenzene process is used by only one company in the U.S.
The major waste water source in this process is the brine
solution from the second decanter, which is contaminated with
phenol and acetic acid. However, an activated carbon system and
chlorination reactor, both being considered as parts of an
integral system of the process, are used to remove phenol by
adsorption and to destroy the acetic acid component. The
effluent from the system is totally recycled for chlorine
production. The adsorbed phenol is desorbed with caustic
solution to form sodium phenate, which is recycled back to the
reactor. Therefore, the process is free of discharge and can be
considered as a standard for BADCT and BATEA.
The cumene oxidation process recycles the water present in the
hydroperoxide reactor. Water from the dilute sulfuric acid in
the cleavage reactor is also recycled. The only significant
waste water stream is generated by water scrubbing the vapor
effluent from the cleavage reactor; this stream contains
dissolved sulfuric acid, sulfates, and oxygenated organic
compounds.
The major paramters of surveyed RWL data from two cumene
oxidation plants are summarized in the following tabulation. The
results of the analyses also show that phenol and oil
contaminants in waste waters from both plants are in excess of
general discharge criteria for biological treatment processes and
would interfere with the normal functioning of such processes.
Plant I Plant 2
Flow 279.6 gallons/1,000 Ib 164 gallons/1,000 Ib
COD a,770 mg/1 84,304 mg/1
11.1 lb/1,000 Ib 11.5 lb/1,000 Ib
BODS 2,410 mg/1 17,575 mg/1
5.6 lb/1,000 Ib 24 lb/1,000 Ib
159
-------
TOG 194 mg/1 77,406 mg/1
0.45 lb/1,000 Ib 105.6 lb/1,000 Ib
The survey data show a significant difference in RWL between two
plants. The lower RWL of Plant 1 is attributed to the
installation of dephenolizer facilities (steam stripper). These
facilities are considered as part of the process rather than end-
of^pipe treatment, since phenol is recovered at this unit and
recycled back to the oxidation reactor. The higher RWL of Plant
2 is attributed mainly to the disposal of concentrated light ends
and heavy ends from acetone and phenol fractionators into the
sewers, instead of by incineration as commonly practiced. RWL
represented by Plant 1 can be logically considered as standard
for BPCTCA control technology.
The activated carbon system mentioned in the chlorobenzene
process has been claimed to be effective in reducing phenol
concentration from about 100 mg/1 down to 1 mg/1. The saturated
activated carbon beds can be regenerated with caustic solution by
desorbing phenol into phenate salt. The salt is then recycled to
the oxidation reactor. With this system, phenol is recovered for
reuse, and the RWL of the process is reduced as well.
Consequently, BADCT and BATEA should require a steam
stripper/dephenolizer with an activated carbon system to achieve
a low RWL standard.
Gross cooling water usages for the two processes discussed above
differ greatly: 3.85 and 463 pounds of water per pound of
phenol, respectively, for the clorobenzene and cumene processes.
Several other process routes in manufacturing of phenol are
currently practiced. These include the Hooker-Raschig process,
toluene oxidation, and sulfonation. Again, the cumene route is
by far the most important, and it is predicted that all phenol
capacity installed over the next ten years will be based on this
process. The current U.S. phenol production capacity and its
estimated economics are presented in Tables IV-35 and IV-36.
The Hooker-Raschig and sulfonation processes are briefly
described in the following paragraphs.
The Hooker-Raschig process is a two-step, vapor-phase reaction.
A benzene chlorination reaction is carried out at 400°F with air,
over a copper and iron chloride catalyst. The copper-iron
catalyst oxidizes the hydrogen chloride to chlorine and water.
The chlorine attacks the benzene ring to yield chlorobenzene and
additional hydrogen chloride. The chlorobenzene is then
hydrolyzed over silica at 900°F to yield phenol and hydrogen
chloride. There is no net production of hydrogen chloride since
it is continually convereted to usable chlorine. The net
products are, therefore, phenol and water.
The sulfonation process is a liquid-phase reaction. Benzene is
first reacted with sulfuric acid to produce benzenesulfonic acid.
160
-------
which is then converted to phenol by caustic fusion. The
sulfuric acid employed in this process is totally lost.
Producer
Table IV-35
U.S. Phenol Capacity-
Plant Location Estimated Capacity Process Route
Allied
Chevron
Clark Oil
Dow
Hercules
Hooker
Monsanto
Reichold
Shell
Skelly
Union Carbide
Natural phenol
Frankford, Pa,
Richmond, Ca 1 .
Blue Island, 1 IK
Kalama, Wash.
Midland, Mich.
Gibbstown, N.J.
N. Tonawanda, N.Y.
S. Shore, Ky.
A 1 v i n , Texa s
Monsanto, 1 1 1.**
Tuscaloosa, Ala.
Houston, Texas
El Dorado, Kansas
Bound Brook, N.J.
Marietta, Ohio
produced
TOTAL
MM Ibs/yr
420
50
70
40
230
100
65
65
375
115
90
50
50
150
125
90
2*085
Cumene
Cumene
Cumene
Toluene oxidation
Ch lorobenzene
Cumene
Raschig
Raschig
Cumene
Sulfonation
Sulfonation
Cumene
Cumene
Cumene
Raschig
-''As of mid-1970. Estimated based on trade literature.
-'-'(•Reported shut down.
161
-------
Table IV-36
Estimated Economics for Phenol Production
(ifOO-MM-lb plant; 1972 construction)
FIXED INVESTMENT COSTS
Process $MM
Cumene 26.6
Toluene 30.0
Raschig 36.1
PRODUCTION COSTS
Raw materials
Labor
Utilities
Maintenance
(6% 1SBL + 3% OSBL)
Overhead
(45% maint. and labor)
Taxes and insurance
(1.5% of investment)
Depreciation (10%)
By-product credit
TOTAL
NET
)umene
e/lb
5.811
0.29
0.92
0.32
0.27
0.10
0.67
8.38
2.74
5.64
Tol uene
t/lb
3.452
0.29
0.71
0.36
0.30
0.11
0.76g
5.98
M .
5.98
Raschicj
C/lb
3.673
0.29
0.78
0.43
0.32
0.13
0.91
6.53
_
6.53
1
1.45 Ib cumene/lb at 3.7C/lb + catalyst and chemicals.
Includes 1.3 Ib toluene at 2.5<£/lb.
•3
J0.94 Ib benzene/lb at 3.4
-------
SUBCATEGORY C
Product Process
Oxo Chemicals Carbonylation and Condensation
The oxo process is a broadly applicable technology which is used
to produce aldehydes which are usually converted to the
corresponding alcohols. The process is used on a number of
feedstocks, the twc most important being propylene and alpha
olefins, to produce linear alcohols for plasticizers and
surfactant usage.
2-ethylhexanol, produced primarily from propylene via n-
butyraldehyde, is the most important oxo chemical in terms of
volume. A process flowsheet describing the manufacture of 2-
ethylhexanol is shown in Figure IV-24 and the basic chemical
reactions are given below:
CH3
C3H6 + CO + Eg —* CH3CH2CH2CHO + CH3 CHCHO
Propylene Carbon Hydrogen n-butyraldehyde iso-butyraldehyde
Monoxide
2CH3 CH2 CH2 CHO _^. CH3 CH2 CH2 CH=C-CHO + H2O
CH2H5
n-butyraldehyde 2-ethylhexanal Water
H
i
CH3 CH2 CH2 CH=C-CHO + H2 —+ CH3 CH2 CH2-CH2-C-CH20H
r H ~ " ~CH2H5
C2H5
2-ethylhexenal Hydrogen 2-ethylhenanol
Carbon dioxide, natural gas, and steam are passed into a
synthesis gas reactor to produce water gas (1:1 ratio of H20 and
CO) which is then mixed with propylene in a liquid-phase reactor
in the presence of a cobalt solution. The reaction is carried
out under pressure and the reactor is maintained approximately
isothermal. A liquid-gas mixture of aldehydes and unreacted
materials is taken overhead from the reactor, cooled, and then
separated in successive high- and low-pressure flashing stages,
whence unreacted synthesis gas is recycled to the oxo reactor.
The catalyst cobalt is then removed continuously from the liquid
phase. The liquid product, containing n-butyraldehyde, iso-
butyraldehyde, and solvent, is separated in two distillation
columns.
N-butyraldehyde is then sent to a condensation reactor, where the
subsequent reaction is carried out at moderate temperature and
atmospheric pressure in the presence of strong base such as
sodium or potassium hydroxide. Continuous removal of the water
163
-------
CO
PROPYLENE
FIGURE IV-24
OXO - CHEMICALS
HYDROFORMYLATION
RECOVERY
ISO-BUTANOL
HEAVY ENDS
WASTEWATER
WASTEWATER
-------
produced during reaction drives the aldol condensation to
completion. The unreacted c°4° aldehyde is separated from the
product 2-ethylhexenal by distillation and is recycled to the
condensation reactor.
The 2-ethylhexenal produced is then hydrogenated to 2-
ethylhexanol in the presence of a solid nickel catalyst in a
pressurized reactor at 50 to 100 atmospheres. After being washed
with caustic solution and water, the reactor effluent is sent to
a fractionator to recover the product 2-ethylhexanol.
The major waste water streams in oxo-chemical manufacturing are
the water removed from the aldol condensation and the water used
in washing the crude product before fractionation into final
product. The waste water may contain some intermediates,
product, and by-product losses. No significant catalyst loss
from the reactor is expected. Heavy ends from various stills are
disposed of by incineration.
The characteristics of the waste water obtained from the plant
survey are summarized in the following tabulation. It should
also be noted from the results of analyses that the oil
concentration in the waste stream is beyond the limits of the
general discharge criterion for biological treatment processes.
Flow 420 gallons/1,000 Ib
COD 1,212 mg/1
4.25 lb/1,000 Ib
BODS 900 mg/1
3.15 lb/1,000 Ib
TOG 549 mg/1
1.92 lb/1,000 Ib
other than reusing the aldol condensation water as wash water, it
is deemed unfeasible tc further reduce RWL of the process by any
in-process modification. Consequently, RWL presented can be
considered as standards for BADCT and BATEA control technology
for this manufacturing process.
An alternate route in oxo chemical manufacturing is based on a
new catalyst system. By carrying out the hydroformation reaction
in an alkaline medium using phosphine-promoted cobalt carbonyl
processes, 2-ethylhexanol and butanol can be produced directly in
one step. Olefin feed and the recycled catalyst stream are
charged to the first of a series of packed reactors at control
rates. Synthesis gas (H2/CO molar ratio = 2/1) is fed separately
to each reactor. The stream taken overhead from the final
reactor is directly sent to the product recovery column. The
bottoms from the product recovery column will contain the
catalyst complex dissolved in a mixture of alcohols and heavy
ends. This stream is recycled to the first reactor with
periodical purging to remove the built-up heavy ends.
165
-------
The U.S. capacity for production of oxo chemicals is presented in
Table IV-37 and the estimated economics for a 40 million pounds-
per-year plant to produce 2-ethylhexanol from propylene is shown
in Table IV-38.
Table IV-37
The U.S. Oxo-Chemicals Capacity
(Millions of pounds)
Company
Dow Badische
Eastman
Enjay
Getty-Air Products
Oxochem
Shell
Union Carbide
USS Chemicals
TOTAL
Locat ion
Freeport, Texas
Longview, Texas
Baton Rouge, La.
Delaware C ity, Del.
Penuelas, P.R.
Geismar, La.
Houston, Texas
Ponce, P.R.
Seadrift, Texas
Texas City, Texas
Haverhi11, Ohio
Capaci ty
200
275
200
40
250
150
200
140
120
200
70
1,845
Source: Oil, Paint and Drug Reporter, Chemical Profile,
April 1, 1971
Table IV-38
The Estimated Economics for Oxo-Chemicals
(40. MM ib. 2-ethylhexanol-from-propylene plant)
Total Fixed Capital=$5.7 MM
Estimated Operation Cost
Cost
Propylene
Synthesi s gas
Catalyst and chemicals
Uti1ities
Labor and overhead
Capital charges
Total
. 2-ethylhexanol
2.1
1.5
2.4
1.6
1.2
4.7
13.5
166
-------
SUBCATEGQRY C
Product_ Process
Acetaldehyde Oxidation of Ethylene (Wacker Process)
The Wacker process employs an aqueous catalyst solution of
palladium chloride, promoted (for metal oxidation) by copper
chloride. The chemistry involved in the process can be
summarized as follows:
C2H4 + 1/2 O2 _»• CE3CHO + Heat
Ethylene Oxygen or Air Acetaldehyde
The catalyst acts as the oxygen carrier and causes selective
conversion of ethylene to acetaldehyde. The reaction steps
essentially are:
Reaction:
C2H4 + 2CUC12 + H2Q PdC1 CH3CHO + 2HC1 + 2CuC1
Ethylene Cupric Water —*• Acetaldehyde Hydrochloric Cuprous
Chloride Acid Chloride
Regeneration:
2CuCl + 2HC1 + 1/2 02 «^. 2CuCl2. + H2O
Cuprous Hydrochloric Oxygen Cupric Water
Chloride Acid or Air Chloride
There are two basic process variations, and choice depends upon
such factors as oxygen cost, utilities prices, and available
ethylene purity. In the single-stage process, pure oxygen is
employed as the oxidant. The reactor effluent is condensed and
water-scrubbed. Unreacted gas is recycled into the reactor. By-
products and water are separated from the acetaldehyde product by
distillation. Both the reaction and regeneration are effected at
the same time.
In the two-stage process, the oxidant is air. The reaction is
carried out with catalyst solution and ethylene in one reactor,
and the regeneration is carried out with air in a separate
reactor. Lowerpurity ethylene can be used with this version of
the process. However, this process forms more by-products and
requires high operating pressures.
The process flow sheet for two-stage Wacker process is shown in
Figure IV-25. The major waste water sources in this process are
the effluents from the scrubber that is required for removal of
unreacted ethylene and uncondensed acetaldehyde vapor, and from
the aqueous bottoms of the acetaldehyde still. The
167
-------
FIGURE IV - 25
ACETALDEHYDE (SINGLE-STAGE WACKER PROCESS)
ETHYLENE
REACTION
J GASES
WATER
SEPARATOR
i fc
a ^^""^^^
WA
OXYGEN
> ^
i •
i
A
I
TER 1
ETALDEHYDE 1
i
V
CATALYST
REGENERATION
SECTION
AIR STEAM
t \
JURGE ACETALDEHYDE ^
1 STRIPPER FRACTIONATOR
WATER
STEAM
I I
1 4 WATER AND
HEAVY IMPURITIES
r
-------
characteristics of the wastewater are shown in the following
tabulation.
Plant I Plant 2 Plant_3
Flow 90 gallons/1,000 Ib 61 gallons/1,000 Ib 35 gallons/1,000 Ib
COD 58,718 mg/1 11,400 mg/1 20,240 mg/1
BOD5 3,700 mg/1 11,500 mg/1
TOC 7,000 mg/1 12,500 mg/1
The foregoing data show the same order of magnitude of raw waste
loads in Plants 2 and 3, and this level of RWL can be considered
as standard for BPCTCA. The high RWL of Plant I is mainly due to
sloppy operation of the acetaldehyde still. To define BADCT and
BATEA control technology, it is required that a steam stripper be
installed to recover and reuse the organic contaminants in the
waste water. A description of the steam stripper, as well as its
estimated economics has been given in the section on aniline.
Because of the aqueous-phase reaction, catalyst metals are
present in the waste water from the acetaldehyde still bottoms as
a result of carry-over from the reactor. The aqueous catalyst
solution is also quite acidic and corrosive. Survey data also
shows that, in addition to metallic contaminants in waste water
stream, sulfate and oil contaminants are found at concentrations
in excess of general criteria for biological treatment processes.
Pretreatment or dilution to reduce their concentrations is
required.
Average process water usage for this process, including steam
directly supplied to the process, is 0.92 pounds per pounds of
acetaldehyde, while cooling water usage amounts to 330 pounds per
pound of product.
Alternate routes for manufacturing of acetaldehyde as well as
U.S. production capacity have been discussed under Acetaldehyde
in Subcategory B. Estimated economics for production of
acetaldehyde by the ethylene route are shown in Table IV-39.
169
-------
Table IV-39
Estimated Economics for Acetaldehyde
(200 MM-lb plant; 1972 construction)
Fixed Capital Investment
Process $ MM
Ethylene 1^.80
Estimated Operation Cost
Raw materials
Utilities
Labor
Maintenance (6% ISBL + 3% OSBL)
Overhead (k5% labor and maintenance)
Taxes and insurance (1.5% of investment)
Depreciation (10 years)
TOTAL
Cost
C/lb ethylene
2. k5
0.82
Q.2k
0.35
0.27
0.11
0.75
1
Includes 0.68 Ib ethylene/lb at 3.3C/lb.
170
-------
SUBCATEGQRY C
Product__ Process
Acetic Acid Oxidation of Acetaldehyde
Acetic acid is produced by the liquid-phase oxidation of
acetaldehyde, using either air or oxygen according to the
reaction given below:
CH3CHO + 1/2 02 —* CH3COOH
Acetaldehyde Oxygen Acetic Acid
The reaction is carried out in the liquid phase at 150°F and 60
psig, with manganese acetate dissolved in aqueous solvent as
catalyst.
The process flow sheet is shown in Figure IV-26. Acetaldehyde
and solvent are fed to the oxidation reactors with a manganese
acetate catalyst solution. The reactor effluent (containing
unreacted oxygen, nitrogen, acetaldehyde, and solvent) is cooled,
and the acetaldehyde and solvent are condensed and recycled back
to the reactor. The non-condensibles are water-washed before
being discharged into the atmosphere. The degassed liquid stream
as well as water from the scrubber are sent to a light-ends
column, where the light ends are distilled overhead. The bottoms
from these distillation columns are sent to a dehydration column
in which water is removed overhead using benzene as the
azeotropic agent. The aqueous phase in the distillate stream is
sent to a solvent stripping column, where acetic acid is removed
as distillate while the bottoms are sent to a waste disposal
unit.
The major waste water source in this process is the water taken
overhead from the dehydration column. The possible contaminants
are unrecovered formic acid and acetic acid. The characteristics
of the waste water obtained from plant surveys is presented in
the following tabulation:
Plant 1 Plant 2
Flow 500 gallons/1,000 Ib 10.2 gallons/1,000 Ib
COD 186 mg/1 306,100 mg/1
0.78 lb/1,000 Ib 26.18 lb/1,000 Ib
BODS 84 mg/1 64,000 mg/1
0.35 lb/1,000 Ib 5.44 lb/1,000 Ib
The foregoing data show a significant variation in RWL between
two plants. Examination of each process shows that the
concentrated light ends and heavy ends from distillation columns
171
-------
FIGURE IV -26
ACETIC ACID, ACETALDEHYDE OXIDATION
i
VAPOR WASH
COLUMN
OXIDIZER
WATER
ACETALDEHYDE
AIR, ACETALDEHYDE
ACETALDEHYDE
STRIPPER
I
.AIR
ACETIC CONDENSER
ACID
STRIPPER
AIR
I
WATER
DEHYDRATION
COLUMNS
I
ACETIC
ACID
-------
are discharged into sewer lines by Plant 2 instead of being
disposed of by incineration as commonly practiced. If these
concentrated streams are excluded, the RWL of Plant 2 as shown
below is comparable to RWL of Plant 1.
Flew 1.48 gallons/1,000 Ib
COD 7,500 mg/1
0.925 lb/1,000 Ib
BODS 26,700 mg/1
0.33 lb/1,000 Ib
There is a slight difference in manufacturing process between
Plants 1 and 2. Plant 1 utilizes ethanol as part of its
feedstock and generates at most 35 gallons of reaction water per
1,000 pounds of product, based on 100X ethanol feedstock. Also,
instead of combining scrubber water with aqueous reactor
effluent. Plant 1 sends scrubber water directly to an
acetaldehyde recovery still and disposes of the bottom stream of
the distillation column. This modification allows Plant 1 to use
more scrubbing water in the scrubber and results in a high amount
of wasteflow.
Based on the foregoing analysis, the RWL of Plant 1 can be
considered the standard of BADCT and BATEA of this process. The
standards of BADCT and BATEA should require recycling of scrubber
water in Plant 1. This modification when implemented will reduce
the flow of BPCTCA to one-tenth its current level, and the RWL by
one half.
Total process water usage of this process is directly
proportional to the amounts of waste water generated. The survey
data show a variation from 4.2 pounds of process water per pound
of acetic acid at Plant 1 to 0.024 at Plant 2. The gross cooling
water usages are 54 and 185 pounds per pound of product for
Plants 1 and 2, respectively.
Several other process routes to acetic acid are also practiced
commercially. The specific processes utilized by each firm with
their respective capacities are presented in Table IV-40. The
CO-Methanol and Petroleum Gases (n-butane) processes are
discussed briefly in the following paragraphs.
Direct liquid-phase oxidation of n-butane in petroleum gases is
normally carried out at 300-350°F under a pressure of 700-800
psig, and the chemical reactions taking place are extremely
involved. The reactor effluent is sent to a vapor-liquid
separator, the gaseous products from this separator are scrubbed
with a heavy hydrocarbon to recover unreacted n-butane, and the
liquid product from the separator is split into an organic and
aqueous phase. The organic phase is recycled, while the aqueous
phase is fractionated to remove intermediate by-products.
173
-------
The CO-Methanol process is the most recent commercial route.
Carbon monoxide and a liquid stream containing the catalyst
system of cobalt iodide and cobalt carbonyl hydride are fed to a
sparged reactor operating at 500°F and 10,000 psig. Product
acetic acid is recovered by fractionation. The methanol
feedstock is normally not introduced directly to the oxidizer,
but rather is used to scrub the reactor offgases, which contain
catalyst in the form of methyl iodide vapor.
Producer
Borden
Celanese
Eastman
FMC
Hercules
Monsanto
Publicker
Union Carbide
Others
Table IV-^0
Acetic Acid Capacity (1972)
Location
Geismar, La.
Bishop, Texas
Pampa, Texas
Clear Lake, Texas
Kingsport, Tenn.
Bayport, Texas
Pa r 1 i n, N, J.
Texas City, Texas
Philadelphia, Pa.
Brownsville, Texas
Texas City, Texas
S. Charleston, W.Va,
Taft, La.
TOTAL
MM Ib
100
200
600
300
325
Process
CO-methanol
Petroleum gases
Petroleum gases
AcetaIdehyde
Aceta1dehyde-ethanol
AcetaIdehyde
AcetaIdehyde
CO-methanol
Aceta1dehyde-ethanol
Petroleum gases
Petroleum gases
Petroleum gases
AcetaIdehyde
174
-------
SUBCATEGORY_C
Product Process
Methyl Methacrylate Acetone Cyanohydrin Process
Methyl Methacrylate is produced by the acetone cyanohydrin
process. The overall chemical reactions are given below:
CH3COCH3 + HCN —* (CH3) 2OHC (CN)
acetone Hydrogen Cyanide Acetone Cyanohydrin
H2SO4
(CH3) 20HC (CN) -1* CH_CH2CONH3HSOU
Acetone Cyanohydrin Methacrylamide Sulfate
CH3OH
CH3CH2CONH3KSO4 -H> CH3CH2CCOOCH3 + NH4HSOU
Methacrylamide~Sulfate Methyl Methacrylate Ammonium Bisulfate
A process flow diagram is shown in Figure IV-27. Acetone
cyanohydrin is
produced by the reaction of hydrogen cyanide and acetone with an
alkaline catalyst in a cooled reaction kettle. The excess
catalyst is neutralized, and crude acetone cyanohydrin passes to
holding tanks. The salt formed by neutralization of the catalyst
is removed in a filter press before the crude acetone cyanohydrin
is fed to a two-stage distillation unit. Most of the water and
acetone are removed and recycled overhead from the first column,
and the remainder of the water is removed at high vacuum from the
second column.
Acetone cyanohydrin and concentrated sulfuric acid are pumped
into a cooled hydrolysis kettle to make the intermediate,
methacrylamide sulfate, which is then sent to an esterification
kettle to react with methanol continuously. To prevent
polymerization, inhibitors are added at various points in the
process. The esterified stream is pumped to the acid stripping
column, from which the acid residue, made up of sulfuric acid
(40% by weight), ammonium sulfate (28%), water (20%) and organic
substances (10%) is sent to a Spent Acid Recovery unit (SAR).
The recovered sulfuric acid is recycled back to the hydrolysis
reactor.
The overhead stream from the acid-stripping column is then
distilled to remove methyl metacrylate and unreacted methanol,
which is recycled. The last traces of methanol in the methyl
metacrylate are removed by water extraction, after which the
monomer is finally purified in a rerun tower.
The acid residue from the acid-stripping column is the major
waste stream generated in the process, and this waste stream is
either sent to the SAR unit previously mentioned or is discharged
into sewers. The waste streams generated as bottoms from various
stills are combined with the acid residue for spent acid
recovery. Water samples from streams leading to and leaving the
SAR unit were taken for analysis, and the results are shown in
the following tabulation:
175
-------
FIGURE IV-27
METHYL METHACRYLATE - ACETONE CYANOHYDRIN PROCESS
HYDROGEN CYANIDE
NaOH
t
TO VAC
CONCENTRATORS
I
TO VAC
HASTE
Na2S04
DISTILL
CYANOHYDRIN
REACTOR
FILTER
SODIUM
DISTILL
SULFATE
ACETONE CYANOHYDRIN
SULFURIC ACID
HYDROLYSIS
REACTOR
TO HIGHER
ACRYLATE
PRODUCTION
ESTERIFICATION REACTOR-
METHANOL SOLUTION
1
^.^
1
RECTI
_***•
r
FIER
t
STEAM
ACID
STRIPPER
COLUMN
ACID RESIDUE
TO HASTE
CRUDE
METHYL METHACRYLATE
DISTILL
DISTILL
.HATER
PURE
METHYL METHACRYLATE
METHANOL RECOVERY COLUMN
DISTILL
EXTRACTION
COLUMN
RERUN
COLUMNS
I
DISTILL
I
TO HASTE
176
-------
Into SAR From SAR
Flow 260 gallons/1,000 Ib 213 gallons/1,000 Ib
COD 178,000 mg/1 110 mg/1
BOD5 20,700 mg/1 15 mg/1
TOC 69,998 mg/1 18 mg/1
A high concentration of floating solids was observed in the
stream leading to the SAR, and it was impossible to obtain a
well-mixed sample. Therefore, samples from the stream were
actually taken from the aqueous phase beneath the floating
solids. The floating solids removed in the SAR were disposed of
by incineration. High concentrations of metal contaminants such
as copper and iron are indicated by the results of the analysis.
Although a large portion of these metals are removed along with
floating solids in the SAR unit, the metal concentrations in the
streams discharged to sewers are still beyond the general
discharge criteria for biological processes. Although sulfuric
acid concentration had been reduced from UQ% by weight in the
influent to the SAR to 1% by weight in the effluent, the sulfate
concentration in the discharge stream was still high enough to
inhibit the normal functioning of the biological treatment
process.
Because of the highly exothermic reactions involved, the process
requires a large amount of cooling water. The survey data show
that gross cooling water usage amounts to 366 pounds per pound of
methyl metacrylate. Process water is introduced into the system
in the form of direct steam stripping in the amount of 0.56
pounds per pound of product.
To define BADCT and EATEA, this process should have a Spent Acid
Recovery unit. Two types of SAR units have been devised, and
descriptions of the equipment processing required, and estimated
economics are presented in the following paragraphs.
1• Spent Acid Recovery by Neutralization
As shown in Figure IV-28, spent acid is neutralized with ammonia
gas to form ammonium sulfate. The effluent from the neutraliza-
tion tank is sent to crystallization and filtration units to
separate ammonium sulfate from the aqueous solution. The econ-
omics of this unit are shown in Table IV-U1.
2. Spent Acid Recovery by Complete^Cgmbustipn The spent acid
solution (see Fig. IV-28) is heated to such a high temperature
(about 1,000°C) that sulfuric acid decomposes into SO2, 02, and
water vapor. Simultaneously, the organic substances are
oxidized, and the contained ammonia converted to N2 and water.
The SO2 gas stream is passed over a catalytic converter to
oxidize the S(D2 to SO3, which is then absorbed to form
177
-------
FIGURE IV-28
SPENT ACID RECOVERY UNITS
1 NEUTRALIZATION
HN3 RR MM LR/HR. . .. 4 AOIIFnilS
CD CUT A P I n fe
2 COMPLETE COMBUST
1 I
CRYSTALIZATION
HFIITR'I I7ATI1N lllk niTDATinid
ON iniiFnm: F
FUEL _
OXYGEN
ENT ACID _^
nnMRUSTinU fc DEHYDROGENATION
9 S02 UXIUAI IUN
OVERHEAD
... . ... ^ AMMONIA SULFATE
390 MM LB/HR.
URGE FRESH WATER
* ABSUHPIION ^ ai)'« SULFURIC ACID
?Rfl MM 1 R/HR
1
WASTEWATER
-------
Table IV-*(1
Economics of Spent Acid Recovery by Neutralization"
Investment
Battery Limits = $2,200,000
Off-site 800.000
Total Investment $3,000,000
Operating Costs
Utilities $/yr
Steam: 720,000 M Ib <5> 60<;/M Ib = $ 430,000
Power: 10,000,000 Kwh <® 0.8 0.70c/lb = $2,730,000
'Based on 485,000,000-lbs/yr Spent Acid Recovery plant.
179
-------
concentrated acid for recycle. The economics of this unit are
shown in Table IV-42.
The economic analyses are based on the following flow rate and
composition of spent acid.
H2SO4 = 245,000-Ib/hr
(NH4J2S04 = 16,500 Ib/hr
H20 = 13,500 Ib/hr
Organic substances = 6,150 Ib/hr
60,650 Ib/hr
The acetone cyanohydrin process is the only methacrylate process
used commercially in the U.S. An alternate route used in Japan
is nitric acid oxidation of isobutylene to metacrylic acid,
followed by esterification with methanol.
Producers of methyl methacrylate in the U.S. are shown in Table
IV-43. The estimated economics of production, based on a unit
that produces 40 million pounds per year, are presented in Table
IV-4 4
180
-------
Table \M-k2
Economics of Spent Acid Recovery by Complete Combustion
Investment
Battery Limits = $3,000,000
Off-site = 1.000.000
Total Investment $4,000,000
Operating Costs
Utilities $/yr
Fuel: 800,000 MM BTU/yr (?) 50<;/MM BTU = $ 400,000
Power: 3,000,000 Kwh (5> 0.8i/Kwh = 24,000
Cooling Water: 750,000 M gal <5> 3i/M gal 22.500
$ 446,500
Amortization = $ 600,000
Labor = 100.000
$ 700,000
Return on Total Investment (5) 20% = $ 800,000
Total Annual Cost = $1.946.500
Net Revenue on Recovered H2SOif
144,000 tons/yr $20/ton = $2,880,000
'Based on 485,000,000-lbs/yr Spent Acid Recovery plant.
181
-------
Table IV-43
U.S. Methyl Methacrylate Capacity
Producer Location Capacity Route
MM Ibs/yr.
Rohm and Haas Houston, Texas
Louisville, Ky. 2UO.O Acetone-HCN
Bristol , Pa.
DuPont Belle, W. Va. 80.0 Acetone-HCN
American Cyanamid Fortier, La. kO.O Acetone-HCN
Escambria * Pensacola, Fla. 20.0 Isobutylene oxidation
TOTAL 380.0
* Shut Down
Source: Oil, Paint and Drug Reporter, March 6, 1967
Table IV-M»
Estimated Economics for Methyl Methacrylate Production
kO. MM Ib. plant
Total fixed capital=$3.2 MM
Acetone Cyanohydrin Process
Estimated Operation Cost
Cost
C/lb. methyl methacrylate
Acetone 5.7
HCN 2.9
Methanol 2.6
Catalyst and chemicals (net) 1.2
Utilities 0.6
Labor and overhead 1.0
Capital charges 2.6
TOTAL 16.6
II. Isobutylene Process
Cost
i/lb. methyl methacrylate
Raw materials 9.3
Utilities 1.8
Labor and overhead 1.0
Total 12.1
182
-------
SUBCATEGQRY C
Product ...
Ethylene Glycol Hydration of Ethylene Oxide
Ethylene glycol is produced from ethylene oxide by liquid-phase,
acidcatalyzed hydration.
H2COCH2 + H2O —+• HOCH2CH2OH
Ethylene Oxide Water Ethylene Glycol
Ethylene oxide and water are reacted at about 300 psig and 180°C
in the presence of sulfuric acid solution. By selection of the
oxide-to-water ratio, it is possible to control the production of
the mono-, di-, and higher glycols produced. Excess water is
required for temperature control and to prevent the formation of
undesirable by-products. Reactor effluent is dehydrated in a
multiple-effect evaporator system. The effluent from the
dehydration section is fed to a series of fractionators. The
first tower removes water and traces of the light-ends, the
second produces fiber-grade mono-ethylene glycol, and the
subsequent towers produce diethylene and higher glycols.
A flow sheet for this process is shown in Figure IV-29.
The condensate from the dehydrator is partially recycled, and the
remainder of this stream is the only source of water pollution in
the process. The characteristics of this waste stream obtained
from survey data is shown in the following tabulation:
Flow 584 gallons/1,000 Ib
COD 1,800 mg/1
8.77 lb/1,000 Ib
BOD5 69 mg/1
0.34 lb/1,000 Ib
TOC 929 mg/1
4.53 lb/1,000 Ib
The high flow of the waste stream is caused by steam jets with
barometric condensers which are utilized to produce vacuum for
the multipleeffect evaporator system. If vacuum pumps with
surface heat exchangers were to replace steam jets and barometric
condensers, the flow of this waste stream could be significantly
reduced. The condensate from the dehydrator could then be
totally recycled back to the reactor. Consequently, BADCT and
BATEA standards should require zero discharge from this process.
The manufacture of ethylene glycol is invariably associated with
ethylene oxide production, and glycol growth rates are moderate.
The U.S. ethylene glycol capacity is presented in Table IV-45.
183
-------
FIGURE IV-29
ETHYLENE GLYCOLS, FROM ETHYLENE OXIDE
00
Ji.
GLYCOL FRACTIONATION COLUMN
ETHUENE OXIDE
—*—•
Jl,
( REACTOR~P
I
.». ETHYLENE GLYCOLS
l?_»
DIETHYLENE GLYCOLS
-------
Estimated economics for ethylene glycol, based on ethylene oxide
availability at 8.50 per pound, are presented in Table IV-46.
Table IV-45
U.S. Ethylene Glycol Capacity
Producer
Allied
Calcasieu
Celanese
Dow
Eastman
GAP
Houston-PPG
Jefferson
Matador
Olin
Shell
Union Carbide
Location
Orange, Texas
Lake Charles, La.
C1ea r La ke, Texa s
Freeport, Texas
Plaquemine, La.
Longview, Texas
Linden, N.J.
Beaumont, Texas
Port Neches, Texas
Orange, Texas
Brandenburg, Ky.
Giesmar, La.
Institute, W.Va.
Ponce, P.R.
S. Charleston, W.Va.
Texas City, Texas
Torrance, Calif.
Seadrift and Taft, Texas
Wyandotte
Giesmar, La.
TOTAL
Mid-1970
Estimated Capacity
MM Ib/yr
60
180
300
500
175
75
35
85
360
35
110
100
230
130
120
220
50
130
150
3.0^5
185
-------
Table IV-A6
Estimated Economics for Ethylene Glycol
(80 MM Ib plant)
Total Fixed Capital = $0.8 MM
Estimated Production Cost
ethylene glycol
Ethylene oxide 6.3
Utilities 0.2
Labor and overhead 0.2
Capital charges 0.3
TOTAL 7.0
186
-------
SUBCATEGQRY C
Product _ _____ Process ___________________________
Acrylic Acid Carbon Monoxide Synthesis with Acetylene
Acrylic acid is synthesized from acetylene anc carbon monoxide in
a catalytic solution. The chemistry can be represented by the
following reaction:
C2H2 + H^O + CO - t C2H3COOH
Acetylene Water carbon Monoxide Acrylic Acid
The acetylene feedstock is first dissolved in THF
(tetrahydrofuran) in an absorption tower. This solution and
carbon monoxide are then mixed in a reactor, and the reaction is
carried out at approximately 450°F and 1,500 psig in the presence
of a nickel bromide and cupric bromide solution. The off-gas
from the reactor is passed through a THF absorber to remove
acrylic acid vapor and unreacted acetylene, and is then scrubbed
by caustic water for further removal of THF and carbon monoxide
from the gas stream. The liquid reactor effluent, a mixture of
acrylic acid, byproduct acetaldehyde, and catalyst solution, is
fed to a separtion column. The overhead is extracted with water
to recover THF and is distilled to yield purified acetaldehyde.
The raffinate from the separation column is sent to a series of
vacuum distillation and extraction columns. The THF and catalyst
solution are recovered and recycled to the acid reactor.
Technical grade glacial acrylic acid is produced in final
distillation columns.
The process flow diagram is shown in Figure IV-30.
The major waste water source is the caustic scrubber water. The
contaminants are THF and Na2CO3_. The characteristics of waste
water samples obtained during recent plant surveys are summarized
in the following tabulation:
Flow 475 gallons/1,000 Ib
COD 414 mg/1
1.64 lb/1,000 Ib
BOD 5 186 mg/1
0.737 lb/1,000 Ib
TOC 387 mg/1
1.53 lb/1,000 Ib
Historical data over a period of two months show that TOC ranges
from 1.73 to 6.92 pounds per 1,000 pounds of acrylic acid and
probability analysis indicates that 50 percent occurrence is
equivalent to 3.08.
187
-------
OFF GAS
SOLVENT fc
THF *
C 2H 2
UJ
CD
DC
CD
CO
CO
«t
H20
§' TF
CD
I—
C-D
FIGURE IV-30
ACRYLIC ACID, FROM ACETYLENE
1
CD
CO
CO
CO
NaOH & WATER
WASTEWATER
CD
CC.
CO
CD
THF
* H20
CD
CO
CO
CO
C3
ACETALDEHYDE
BY-PRODUCT
RECYCLE THF
CATALYST
SOLUTION
CRUDE ACRYLIC
ACID
CATALYST
PREPARATION
N i B r;
Cu Br'
RECYCLE
ACETYLENE
RECYCLE WATER
TECH.GRADE
ACRYLIC ACID
VACC.
RECYCLE CATALYST SOLUTION
(Ni Br2,CuBr2,WATER)
RECYCLE THF
^ MEK
— o
I— CJ
CO LLJ
— CC
1— ^
r
o=
1—
CJ
QC
X
LLJ
^mtm
•^
VAC
z
CD
-------
The high waste water flow rate is attributed to the utilization
of steam jets used to produce a vacuum in the distillation
columns. Converting steam jets to vacuum pumps can certainly
reduce the amount of waste water generated, although the RWL in
terms of COD, BOD5, etc. will remain the same. Other than
reducing waste water flow rate, in-process modification is deemed
unfeasible to further reduce RWL, and consequently, the data
presented can be considered as standards for BADCT and BATEA.
A wide range of technology is used to produce acrylic acid. The
other important route is based on propylene technology. A
mixture of propylene, air, and steam is fed to two tubular
catalytic reactors in series and cooled by circulation of molten
salt. Most of the acrylic acid is condensed and separated from
the gaseous stream by quenching. The resulting aqueous solution
is then subjected to an extraction with solvent, followed by
distillation for purifying the product and recovering the
solvent.
U.S. manufacturing capacity of acrylic acid and the individual
specific processes used are presented in Table IV-47, and an
estimated economic comparison of the acetylene- and propylene-
based technologies is shown in Table IV-48.
189
-------
Producer
Celanese
Dow Badische
Dow Chemical
Goodrich
Rohm and Haas
Union Carbide
TOTAL
Table
U.S. Acrylic Acid and Acrylates Capacity
Plant Location
Pampa, Texas
Freeport, Texas
Freeport, Texas
Calvert City, Ky.
Bristol, Pa.
Houston, Texas
Institute, W. Va.
Taft, La.
Est. Capacity
(MM Ibs./yr.)
80
kO
10
10
250
70
200
660
Process
Used
b-propiolactone
Acetylene-CO
Propylene
b-Propiolactone
Acetylene-CO
Ethylene oxide-HCN
Propylene
^Capacities as of m.id-1970 estimated by Stanford Research Institute, CEH . CEH
comments that the Dow facility is not due for start-up until late 1970 and the
Carbide cyanohydrin plant will be shut down when the propylene plant is up to
full capacity by early 1971.
Table IV-48
Estimated Acrylic Acid Economics
(150-MM Ib. plant; 1972 Construction )
Total Investment Cost
Process
Acetylene
Propylene
10.0
16.9
Production Cost
Raw material s
Util ities
Labor
Maintenance (6% ISBL +- 3% OSBL)
Overhead (4570maint. * labor)
Taxes and insurance (1.5% of invest.)
Depreciation
, TOTAL
C/lb.
Route: Acetylene
6.85 ]
0.80
0.27
0.32
0.27
0.10
0.67
9.28
Propylene
3.24 2
1.12
0.33
0.54
0.39
0.17
1.14
6.93
0.42 Ib./lb. at 8.0e/lb.
20.88 Ib./lb. at 3.0tf/lb.
190
-------
SUBCATEGORY C
Product Process
Acrylates Esterification of Acrylic Acid
Acrylates are manufactured by esterification of acrylic acid.
There are four main acrylates plus a large number of specialty,
smaller-volume derivatives. The main four are ethyl, 2-
ethylhexyl, methyl, and n-butyl in decreasing order of market
share. The 2-ethylhexyl and butyl acrylates are produced in a
separate facility from the methyl and ethyl esters due to their
differences in volatility and solubility.
In the manufacture of methyl or ethyl acrylates, acrylic acid is
reacted with an excess amount of methanol or ethanol in a
concentrated sulfuric acid solution. The effluent from the
reactor goes to an extraction column, where caustic removes the
excess alcohol. The effluent water stream is sent to a
distillation column; alcohol is recovered overhead and recycles,
while the acrylate stream is purfied in two distillation columns
by removal of light and heavy ends.
In the manufacture of butyl, 2-ethylhexyl, and higher acrylates,
the esterification is conducted in the presence of cyclohexane,
which is used to remove the water of reaction. The reactor
effluent is first neutralized with caustic and then sent to a
series of distillation columns. Acrylate is purified, while the
excess alcohol is recovered and recycled.
The major process units of the first process are shown in Figure
IV-31, and the chemical reaction can be expressed by the
following formula:
C2H3COOH + R-OH H2S04 C2H3COOR H2O
Acrylic Acid Alcohol Acrylates Water
The two main sources of water pollution in acrylate manufacture
are the bottoms of the alcohol recovery still and the effluent of
the saponification kettle. The possible contaminants in the
waste stream are acrylic acids, alcohols, and sodium salts of
various acids. The results of the plant survey are presented in
the following tabulation:
Flow 2,856 gallons/1,000 Ib
COD 4,870 mg/1
117.5 lb/1,000 Ib
BODS 1,942 mg/1
47.1 lb/1,000 Ib
191
-------
FIGURE IV-31
ACRYLATES
H2S04
CAUSTIC WATER
o
IN)
1H OR CHgOH
ACRYLIC ACID
I
ESTER1FICATION
REACTOR
L
RECYCLE ROH
EXTRACTION
COLUMN
STILL
ALCOHOL
RECOVERY
STILL
I
SAPONIFICATION
KETTLE
METHYL ACRYLATE
OR ETHYL ACRYLATE
STILL
HEAVY ENDS (BURNED)
WASTEWATER
WASTEWATER
-------
TOC 3,290 mg/1
79.5 lb/1,000 Ib
Historical data over a period of two months show that total
carbon in the waste stream ranges from 15.50 to 46.36 pounds per
1,000 pounds of acrylate produced. Probability analysis of the
data indicates that 50 percent occurrence is equivalent to 30.8
pounds per 100 pounds of product.
From the data presented in the preceding paragraphs, it is known
that inefficient operation of distillation columns causes
significant losses of organics such as alcohol, acrylic acid, and
acrylates into the waste stream. Recovery of these organics can
be achieved by modification of the distillation columns or by
installation of a steam stripper. The amount of waste flow can
also be reduced by recycling the waste water to an extraction
column.
BADCT and BATEA in-process controls should require a steam strip-
per to recover organic contaminants in the waste stream and thus
achieve a low RWL.
The U.S. acrylate capacity is presented in the same table used
for acrylic acid (Table IV-47).
193
-------
SUBCATEGORY C
Product Processes
Terephthalic Acid "l. Nitric Acid Oxidation of Para-Xylene
2. Catalytic Oxidation of Para-Xylene
Terephthalic acid (TPA) constitutes virtually the sole use for p-
Xylene. Based on the mode of oxidation, manufacturing processes
can be divided into the following two classifications:
1. Oxidation of p-Xylene with nitric acid,
2. Catalytic oxidation of p-Xylene.
Only one company is using the nitric acid oxidation of p-xylene
in the United States. This process is a liquid-phase reaction at
approximately 300°F and 125-200 psig in dilute HNO3 (about 30-40
weight percent). Oxygen or air is passed into the reactor, where
oxidation of p-xylene and lower oxides of nitrogen takes place
simultaneously. The nitric oxides can be used for nitric acid
regeneration.
The second reaction, represented by at least three commercial
processes, utilizes acetic acid as a reaction medium and also
involves a heavy metal oxidation catalyst. The most widely used
commercial process is the Mid-Century process, in which the
oxidation is reported to be based upon a bromine-promoted heavy
metal catalyst, such as cobalt-manganese. Reaction conditions
are 350-450°F and 200-400 psig. The second process utilizes
acetaldehyde as a promoter in place of bromine compounds, and the
reaction is carried out at 250-350°F and 100-200 psig. The third
process uses methyl ethyl ketone as the catalyst activator and
operates at 200-300°F and 50-150 psig.
A typical flow sheet for the catalytic oxidation process is shown
in Figure IV-32. Preheated acetic acid, p-xylene and bromine
catalyst, together with high-pressure air are charged to a well-
agitated reactor operating at moderate temperature and pressure.
The reactor contents are continuously discharged from the bottom
of the reactor as a hot slurry into a crystallizer vessel, where
cooling takes place by flashing off part of the acetic acid,
unreacted xylene, and some water of reaction. The terephthalic
acid slurry is passed to a centrifuge for removal of acetic acid
and xylene. The filter cake is washed to remove the remaining
reactants and then is dried to give the terephthalic acid
product. The spent reaction liquor and condensate from the
crystallizer vessel are distilled to remove water, recover
unreacted Xylene and acetic acid, and remove any other by-
products. The acetic acid is recycled. The off-gas from the
reactor is scrubbed with water before being discharged into the
atmosphere. TPA obtained from this process is considerably purer
than that produced by nitric acid oxidation, usually more than 99
weight percent TPA in contrast to 93 weight percent TPA of the
other process.
194
-------
MEK
10
on
FIGURE IV-32
TEREPHTHALIC ACID, P-XYLENE TO POLYMER GRADE TPA
OXIDATION-LEACH STACK
SCRUBBER
STEAM
LENb '
GAS SEPARATION
~* RFACTOR , -. »
r»
1 1
RFrvn r SOLVENT
« CYC Lt RECOVERY t
SYSTEM
|
KASTEWATER
WATER
k WASTEWATER
ORGAt
RECYCLE ACETIC ACID
i 4
t CRUDE TPA
iEPARATIOh
1 '
— T LKTil
-fc — fei ^
SLURRY LEACH
TANK FURNACE
fr RECYCLE
ties
RECYCLE
ALIZER ACRTIC AC
^ LEACH TPA _,
1 SEPARATIQf
1 INERT
NiTfinRFL
SYSTEM
D
LEACHED * '
ft PRODUCT
Dj^lV^R
GAS , .
' ' TD»r
CARRIER
ACETIC ACID STORAGE TANK
RECYCLE ACETIC
NITROGEN
TPA(TECHYICAL GRADE*
r
FPU
FEED TANK
Lr
4 ,
WATER 1 T
1
CONDENSATION
I V * W 6CU 1 IUI1 »•
STEAM »-/\/\,T *SH
.ry-'W-
JJ
UJ CO
C3 >-
O —1
Of <
^ " (
1 CATALYST 1
^ FILTER
TO CATALYST . rnnniirr
RECOVERY COOLER
1 1
• • INtKr UAS UARRItR rULYMtK UKAUt I V A
STEAM SUPERHEATER
AND TPA VAPORIZER FURNACE
g i
-------
At some plants, the TPA product is further purified to produce
fibergrade material. The TPA is washed with hot water to remove
traces of catalyst and acetic acid. The hot water slurry is then
heated and pumped into fixed-bed reactors and hydrogenated. This
is followed by crystallization and drying to recover the fiber-
grade TPA.
The major waste water streams in the oxidation process are the
bottoms from the solvent recovery unit and the effluent of the
off-gas scrubber, and the major waste source in the purification
process is the discharged mother liquid from the centrifuge. The
characteristics of the wastewater obtained from plant visits are
summarized in the following tabulation.
Plant Process
Catalytic
Purification
Catalytic
10% Occurrence
50% occurrence
gal/1,000lb~
43.4
715
186
186
COD
1.95
(5,400)
8.22
(1,380)
0.915
1.72
__BOD5
lb/1,000 Ib
(mg/1)
1.30
(3,600)
5.15
(865)
0.51
0.82
TOC
1.52
(4,200)
3.53
(510)
0.55
0.86
90% Occurrence 186
Catalytic 1,090
Nitric Acid 659
2.52
227
(24,950)
104
(18,900)
1.18
68.3
(7,500)
58.7
(10,700)
1. 16
34
(3,730)
44.9
(8, 180)
Plant 2 has five indentical modules operating in parallel. Data
obtained at this plant over a two day period were analyzed for
probability of occurrence.
Historical RWL data on process waste water flow and COD were
obtained for the catalytic oxidation process at Plant 1. At this
plant, there are actually two oxidation process modules, which
operate in parallel. The data from these two units were
subjected to analysis for probability of occurrence. The
following tabulation summarizes the results of this analysis:
Probability of Occurrence Ratio
To%~ 50% 90% 90/50
Flow RWL,
gallons/1,000 lb
196
-------
Oxidation Unit A 132 174 217 1.25
Oxidation Unit B 95 137 181 1.32
Purification Unit 754 969 1,185 1.22
COD RWL,
lb/1,000 Ib
Oxidation Unit A 8.5 12.5 16.5 1.33
Oxidation Unit B 4.9 11.2 25.5 2.28
Purification Unit 12.8 27.4 58.5 2.14
The probability analysis was conducted on monthly average data
taken by the manufacturer over a period of twenty-four months.
Comparison of the sampling results and historical results for
Plant 1 shows that both the measured process waste water flow and
the COD RWL were significantly lower at the time of sampling.
This is attributed to the fact that the historical data include
surface runoff from the battery limits area. This amounts to
approximately 85 gallons/1,000 Ib of product, with an associated
COD loading of 3.5 Ib per 1,000 Ib of product.
The differences in RWL among the plants can be explained. The
nitric acid oxidation process produces nitric oxides which are
supposed to be used in producing nitric acid. However, it is
likely that these nitric oxides are discharged into sewer at the
plant which was visited during the survey. This results in a
high organic loading in the waste water. The high RWL of Plant 3
is due to poor process performance. Since both Plant 3 and Plant
4 are scheduled to be phased out in the very near future, further
investigation of possible in-process modifications to reduce RWL
is not warranted.
Both Plant 1 and Plant 2 utilize steam ejector systems to obtain
vacuum for process needs. In contrast to discharging the exhaust
stream into the atmosphere, as at Plant 1, Plant 2 employs
barometric condensers to condense the exhaust stream. This
causes a significant difference in the amounts of waste water
generated.
To define BADCT and BATEA of the oxidation process, vacuum pumps
with surface condensers should take the place of steam ejectors
and barometric condensers, to reduce the amount of waste flow as
well as to preserve the ambient air quality. If a steam stripper
like that described in the discussion of aniline should be
installed to recover organic contaminants in the waste water of
the purification process, RWL can be reduced approximately by
about three-fourths.
Process water usages as well as gross cooling water usages are
varied among plants and processes. Information obtained from the
plant survey is shown in the following tabulation. Plants are
identified with the same identification as that used for RWL.
Plant Process Water Usage Cooling Water Usage
197
-------
1 (Oxidation)
1 (Purif ica-tion)
2
3
4
Ib/lb product
N.A.
N.A.
N.A.
N.A.
4
Ib/lb product
N.A.
N.A.
188
N.A.
20,000
Several approaches to manufacture of TPA are under investigation,
but none of them has been commercialized in the United States.
The current U.S. capacity for TPA is presented in Table IV-49.
The estimated economics for TPA manufacture bythe oxidation
process are shown in Table IV-50.
Table IV-49
U.S. Terephthalic Acid Capacity
Producer Plant Location
Est. Crude
TPA Capacity
(MM Lbs./Yr.)
Amoco
DuPont
Eastman
Mobil
Total
Decatur, Ala.
Joliet, IH.*
Gibbstown, N. J.
Old Hickory, Tenn.
Kingsport, Tenn.
Beaumont, Texas
'-''May be shut down or switched to isophthalic acid produc-
tion.
Source: Chem Systems' estimates as of mid-1970.
198
-------
Table IV-50
Estimated Economics for Terephthalic Acid
(400-MM 1b plant--I972 construction)
Investment cost
Process
Oxidation (Bromine compound) 52.9
Oxidation (Methylethyl Ketone) 58.6
Production costs
C/1b
1 2
Amoco Mob i1
Raw materials 6.62
Utilities 0.65
Labor 0.09
Maint. (6% ISBL + 3% OSBL) 0.64
Overhead (kS% maint. + labor) 0.33
Taxes & insurance (1.5% of invest.) 0.20
Depreciation (10 yr) 1.32
Total 9.85
By-product credit _-_
Net 9.85 ToTfO
2lncludes 0.6? lb p-xylene at 6.5C/lb.
P-xylene at 6.5^/lb and methylethyl ketone at 10e/lb;
0.67 lb p-xylene/lb and 0.25 lb MEK/lb; .20 lb acetic
acid at 6.0£/1b as by-product credit.
199
-------
SUBCATEGORY C
Product Process
Dimethyl Terephthalate Esterification of TPA
The high-purity monomer required for the development of polyester
fibers and films is produced by converting terephthalic acid
(TPA) to dimethyl terephthalate (DMT) . However, with improved
technology for the manufacture of fiber-grade TPA, it is expected
that most of the new fiber and film capacity installed will be
based on purified TPA.
In the process for the esterification of TPA to DMT, preheated
TPA and methanol are fed to a reactor in the presence of sulfuric
acid as a catalyst. DMT in the reactor effluent is recovered and
purified by conventional methods such as crystallization and
distillation.
A flow sheet for this process is shown in Figure IV-33.
The water separated after condensation and the benzene used in
the reactor to prevent the methanol from vaporizing too rapidly
are the major water pollution sources. The waste water may
contain some alcohol, benzene, and proproduct or by-product
losses. Another water pollution source is the waste stream
resulted from cleaning up scattered product resulting from leaks
in various portions of the equipment. The characteristics of the
waste water obtained from plant surveys are shown in the
following tabulation:
Plant 1 Plant 2 jglant_3
Flow, gal/1,000 Ib 68.8 388 1,070
COD,
lb/1,000 Ib 8.93 55.2 0.91
mg/1 15,000 17,000 102
BODS,
Ib/1,000 Ib 4.81 31.0 0.19
mg/1 8,400 9,580 21
TOC,
lb/1,000 Ib 3.88 22.5 0.62
mg/1 6,800 6,950 69
Historical RWL data on process waste water flow and COD were
obtained at Plant 1. At this plant, there are actually two
modules, with different production capacities, operating in
parallel. The results of the analysis for probability of
occurrence are summarized in the following tabulation:
200
-------
TOZ
METHANOL
RECOVERY
REACTOR
DISTILLATION
DISTILLATION
DISTILLATION
m
•H
I
rn
70
m
-o
I
m
x
m
-H Tl
m f*.
70 *>
5 £
O m
^. _
^j <
O co
Z to
O
TO
m
-o
O
>
O
O
-------
Flow RWL
(gal/1.000 Ib)
Unit AUnit B
COD RWL
Ob/1.0.QO l£)_"
Unit A ~ Unit B
10% Occurrence
50% Occurrence
90% Occurrence
Ratio 90%/50%
167
313
461
1.47
150
248
344
1.39
13.5
34.
86.5
2.54
16.1
33.7
70.5
2.06
The analysis was based on consecutive 30-day average data
collected by the manufacturer over a period of 24 months. The
data show that there is only a slight variation between two units
of different sizes at the same plant. However, the measured RWL
is significantly lower than that from historical data. Again,
the difference is due to the fact that historical data includes
surface runoff caused by rainfall and housekeeping.
The survey data also reveal significant variations among plants.
The high waste water flow of Plant 3 is caused by steam jets with
barometric condensers, while the Ic ; flow of Plant 1 is due to
discharging steam jets directly into the atmosphere. The
variation in organic loadings between Plant 1 and Plant 3 is due
mainly to different performance efficiencies of the solvent
recovery units and to varying effectiveness of preventive
measures for process leakages. The high RWL presented by Plant 2
is attributed to the low-purity TPA manufactured by nitric acid
oxidation. Plant 2 is scheduled to be phased out in the very
near future.
To define BADCT and BATEA, it is certain that vacuum pumps with
surface heat exchangers should be utilized in producing vacuum
for process needs and that good performance of solvent recovery
units should be required. Also, excellent preventive maintenance
should be emphasized to reduce RWL.
Process water usage and gross cooling usage are presented in the
following tabulation:
Plant
Plant 1
Plant 2
Plant 3
Process Water Usage
Ib/lb product
N.A.
2
N.A.
Cooling Water Usage
Ib/lb product
N.A.
23,000
150
An alternate route in the manufacture of DMT is the Hercules
process. This synthesis involves liquid-phase oxidation of p-
Xylene in acetic acid with a cobalt acetate or naphthenate as a
catalyst to produce ptoluic acid. This is subsequently
esterified with methanol to produce diethyl hydrogen
terephthalate, which is finally esterified to form DMT.
The U.S. capacity for DMT is shown in Table IV-51.
202
-------
Table IV-51
U.S. Dimethyl Terephthalate Capacity
(Million Ibs./yr.)
Estimated Capacity
Producer Plant Location
Amoco Joliet, 111.
Decatur, Ala.
DuPont Gibbstown, N.J.
Old Hickory, Tenn
Eastman Kingsport, Tenn.
Hercules Burlington, N.J.
Spartenburg, S.C.
Wilmington, N.C. ^00
Total 600
p-Xylene
__
—
—
.
—
100
100
koo
Crude TPA
150
150
250
250
300
—
—
—
Total
150
150
250
250
300
100
100
koo
1100
1700
203
-------
SUBCATEGORY_C
Product Process
Para-Cresol Sulfonation of Toluene
As in the case with other coal-tar derivatives, the supply of
coke-oven by-product cresylics has failed to keep up with demand.
P-cresol was the first isomer to be synthesized commercially and
is produced by sulfonation of toluene. The basic chemical
equations are given below:
C6H5CH3 + H2S04 —* (SO3H) C6H4CH3
Toluene Sulfuric Acid
(S03H)C6H4CH3 + NaOH l (OH) C6H4CH3 + Na2SO3
P-Cresol ~ ~
A process flow sheet is shown in Figure IV-34. Toluene and a gas
mix ture of sulfur dioxide and sulfur trioxide are fed into a
sulfonation reactor. The reactor effluent gas is passed through
a caustic scrubber to remove unreacted sulfur dioxide. The
liquid effluent from the reactor is first diluted with steam and
then sent to a caustic fusion column, where crude p-cresol is
produced. The crude product is then sent to a washing-separation
column, where excess caustic solution is neutralized and two
phases are formed. The aqueous phase is discharged from the
system, and the organic phase is fractionated to obtain pure p-
cresol.
Since the sulfonation reaction approaches 100 percent conversion
of sulfur dioxide and trioxide, the vent gas scrubber water does
not present a significant water pollution source. The major
waste water stream is the aqueous phase discharged from the
sulfuric washing/separation column. The average composition of
this stream is 77 percent water, 15.2 percent sodium sulfite, 5.1
percent sodium sulfate, 0.4 percent cresylic compounds, and 1.7
percent other organic substances such as cresols, phenols, etc.
The data obtained from Plant 1 are shown in the following
tabulation:
Flow 1,291 gallons/1,000 Ib
COD 23,800 mg/1
256 lb/1,000 Ib
BOD5 11,400 mg/1
123 lb/1,000 Ib
TOC 5,020 mg/1
54 lb/1,000 Ib
The sulfite and organic contaminants cause the high oxygen demand
in the waste water, while the eresol contaminant (10 mg/1)
constitutes an odorous nuisance in the atmosphere.
204
-------
S07
-------
According to the literature, the organic contaminants in the
waste water exhibit very strong anti-oxidant properties and
present a difficulty to ordinary biological treatment processes.
Several possible methods of controlling this waste water
discharge have been investigated. The most promising scheme
appears to be activated carbon adsorption of organic contaminants
prior to oxidation, followed by chemical regeneration of cresylic
compounds adsorbed on the carbon, to return a valuable product to
the process, eliminate the odor problem, and reduce the discharge
of pollutants.
A demonstration plant and its economics are briefly described in
the following paragraphs. The system consists of two 4ft-
diameter by 30ft high columns of 304 L stainless steel. Each
column is loaded to a height of 18.5 ft. with approximately 6,000
pounds of activated carbon. The system was designed to have
sufficient capacity for a one-day operational cycle, requiring
one column to be regenerated each 24 hours. Ten percent sodium
hydroxide solution is used to regenerate spent activated carbon,
and the desorbed cresylic compounds are recycled back to the
process. During a seven-month period, the columns were operated
at an average superficial velocity of 3.2 gpm/ft. Influent
concentrations during the period were 3,500 to 6,500 mg/1
cresylic compounds, and effluent concentrations were between 0
and 700 mg/1 cresylic compounds. During this time, 271,600
pounds of p-cresol were returned to the process. This amount of
p-cresol represents a value of $114,000.
As demonstrated, the activated carbon system not only can recover
p-cresol from the waste water and turn it into profit, but also
can decrease the RWL of the system. Furthermore, it improves the
treatability of the waste water. Consequently, to define BATEA
and BADCT control technologies, an activated carbon system should
be incorporated into the process.
Two other process routes for the manufacture of p-cresol are
currently practiced: vapor-phase methylation of phenol over
alumina catalysts, and liquid-phase oxidation of meta- and para-
cumene.
Producers of p-cresol in the U.S. and the economic of production
are presented in Tables IV-52 and IV-53
206
-------
Table IV-52
U.S. Cresol Capacity (1972)
Company MM 1b Process
Hercules, Inc. (Gibbstown, N.J.) 6 p-cymene oxidation
Koppers (Follansbee, W. Va.) 10 phenol and methanol
Pitt-Consol (Newark, N.J.) 80 phenol and methanol
Sherwin Wil1iams (Chicago, 111.) 10 toluene sulfonation
Total 106
Table IV-53
Economic Evaluation of Activated Carbon System
for Wastewater from p-Cresol*
1. Annual Operational Cost
Depreciation (10 year straight line) $ 14, 400
Maintenance (5% of installed cost) 7,000
Utilities 1,050
Raw Materials (NaOH and Filter Aid) 17,250
Labor (using existing manpower) 0
Carbon Make-Up 4.000
$ ^3,700
11. Annual Net Revenue $210,320
(500,770 pounds p-cresol recovered/year,
sale price= $0.42/pound)
111. Analysis
Gross Profit= $210,320 — $43,700= $166,620
Tax (50%) = 83.310
After Tax Profit = $ 83,310
After Tax Cash Flow= $83,310 + $14,400= $97,710
After Tax RD '^ x 100%= 67.9
Payout Time = = 1 .47 yrs.
^"Recovery of P-Cresol from Process Effluent," Baber, C.D., Clark,
E.W. , Jesernig, W.V., and Huether, C.H., Presented at the 74th
AlChE, New Orleans, La., March 1973.
207
-------
SUBCATEGORY C
Product Process
Aniline Nitration and Hydrogenation of Benzene
Benzene is first converted to nitrobenzene in a mixture of nitric and sul-
furic acids:
H2S04
C6H6 + HNO3 f C6H5N02 + H20
Benzene Nitric Acid Nitrobenzene Water
The reactor effluent is decanted into a liquid/liquid separator,
where crude nitrobenzene is separated from the acid solution.
The acid solution is concentrated by steam stripping and recycled
back to the reactor. Crude nitrobenzene is washed, vaporized,
and fed to a fluidized-bed reactor containing a copper-silica
hydrogenation catalyst, where the following hydrogenation
reaction occurs:
C6H5NO2 + 3H2 _«* C6H5NH2 + 2H2O
Nitrobenzene Hydrogen Aniline Water
The unreacted hydrogen is recycled to the reactor. Reactor
effluent goes to a separator, where two phases are formed. The
organic phase contains water, and is fractionated in a two-tower
system to remove heavy residue and water from the aniline
product. The aqueous layer, formed by the water of reaction,
contains some aniline and is discharged into sewers.
The process flow diagram is shown in Figure IV-35.
The major waste water sources in this process are the crude
nitrobenzene wash water and aniline water formed in the final
separator. RWL survey data of this process are shown in the
following tabulation:
Flow 190 gallons/1,000 Ib
COD 13,400 mg/1
21.2 lb/1,000 Ib
BOD5 15 mg/1
0.02 lb/1,000 Ib
TOC 12,150 mg/1
19.2 lb/1,000 Ib
Results of analyses indicate that, in addition to the parameters
shown above, sulfate concentrations in waste water streams are at
levels inhibitory to biological treatment processes. The high
RWL of this process is attributed to the high aniline
208
-------
FIGURE IV-35
ANILINE
C6HG
K)
O
ANILINE
ANILINE WATER
STEAM
-------
concentration (3 percent) in aniline water from the final
separator. It is a common practice to recover aniline by
extraction either with incoming nitrobenzene or with benzene.
However, such recovery was not practiced at the plant visited
during the survey.
BADCT and BATEA in-process controls are defined by implementing
an aniline recovery system to reduce process RWL. Instead of
using a nitrobenzene extraction scheme, an effective steam-
stripping system has been devised, and the following is a
description of the equipment and processing required.
Water from a 108 Ib/yr aniline plant is steam stripped in a 2.51
x 40« tower. The feed to the stripper is 17 gpm containing 3.1
percent aniline by weight. The bottoms from the stripper will
contain about 0.2 percent aniline. The overhead, essentially a
50/50 mixture of aniline and water is sent to incineration.
Figure IV-36 is a process flowsheet of the proposed aniline
stripper system.
With this modification, RWL can be expected to achieve the
following values:
Flow 184 gallons/1,000 Ib
COD 1,390 mg/1
2.13 lb/1,000 Ib
TOG 1,490 mg/1
2.29 lb/1,000 Ib
The totally installed cost for the stripper, including heat
exchange, pumps, instrumentation, piping, foundations, electrical
wiring, structures, etc. is $115,000. The total annual operating
cost, including depreciation, is about $45,900. For the 108
Ib/yr aniline plant, this adds about .052/lb to the cost of the
aniline. Table IV-54 presents the economics of the proposed
aniline stripper.
The alternate routes in manufacturing aniline are the traditional
technique of nitrobenzene liquid-phase reduction with iron
filings and the liquid-phase nitrobenzene hydrogenation
technique. U.S. aniline capacity from these processes is
presented in Table IV-55. Assuming that nitric acid and sulfuric
acids are available at $30 per ton, estimated production costs
for a 40.0 million pounds per year aniline plant, including
benzene nitration facilities, are shown in Table IV-56.
210
-------
FIGURE IV-36
ANILINE STRIPPER
100 °F
«—I
248# ANILINE
230# WATER
TO INCINERATOR
8236 #/HR.
WATER
264#/HR.
ANILINE
20 PSIG
150° F
180°F
.2-1/2 0 x 40
18 TRAYS
2500 #/
40 PSIG
STEAM
HR.
C.W.
95°F
8006# WATER
16# ANILINE
211
-------
Table IV-5*t
Aniline Stripper Economics
Investment
Tower Cost, including trays, pumps, exchanges, _ . nnnTni-allv inst
instruments, piping, foundations, etc. ~ >"!!>,UUU totally Inst.
Operating Costs
Uti1ities
C/Gal Handled 0.55 C/Gal.
£/lb Aniline removed 2.36<£/lb
In 100 MM #/yr Facility 0.045
-------
Table IV-55
U.S. Aniline Capacity (1972)
Company
Allied
American Cyanamid
DuPont
First Chemical
Mobay
Rubicon
Total
Locat ion
Moundsvilie, W. Ma
Bound Brook, N.J.
Wi How Island, W.Va.
Gibbstown, N.J.
Beaumont, Texas
Pascagoula, Miss
Hew Martinsvi1le, W. Va.
Geismar, La.
MM Ib
60
60
40
130
200
35
70
kQ
585
Table IV-56
Estimated Economics for Aniline
( 40. MM Ib. plant)
Total Fixed Capital=$3.2 MM
Estimated Operation Cost
Cost
Benzene
Nitric Ac i d
Hydrogen
Catalyst and chemicals
Uti1ities
Labor and overhead
Capital charges
<;/lb. ani1ine
3.1
2.4
0.8
0.3
0.4
0.6
2.6
foTi
213
-------
SUBCATEGORY C
Product Process
Bisphenol-A Condensation of Phenol and Acetone
Diphenyl propane, also known as bisphenol-A, is produced by
reacting phenol with acetone in the presence of acid catalyst,
and the chemical reaction is given below:
2C6H50H + CH3COCH3 ^+ CH3C (C6HUOH) 2CH, * H^°
Phenol Acetone Bisphenol-A~ 3 Water
A number of by-products are formed in conjunction with the main
reaction. The earlier processes eliminated these impurities by
batchwise crystallization, while the new process, the Hooker
process, employs a continuous distillation and extractive
crystallization under pressure to purify the product.
A process flow diagram of the Hooker process is shown in Figure
IV-37. Phenol and acetone at a molar ratio of .approximately
three to one are mixed, saturated with hydrogen chloride gas, and
sent to the reaction vessel. Reaction conditions are about 40°C,
close to atmospheric pressure, with a mercaptan used as a
catalyst. The crude product is stripped of HC1 and water of
reaction. The overhead is decanted into an organic phase
(consisting mainly of phenol which is recycled) and an aqueous
phase. The latter goes on to an HCl-recovery unit, and water is
sent to disposal.
Bottoms from the stripper are sent to a series of purification
distillation chambers, where excess phenol, isomers, and heavy
ends are removed from the system for either recycle or disposal.
Distillate from the last chamber is sent to the extraction
operation, which produces a slurry of pure crystals. The
filtrate from the centrifuge is partially recycled to the
crystallizer, and the remainder is concentrated in an evaporator
to produce liquid bisphenol-A.
The water separated from the HCl recovery unit, the extracted
aqueous phase from the crystallizer, and the condensate from the
final evaporator are the major waste water sources. The
characteristics of the waste water obtained from survey data are
presented in the following tabulation:
Flow 66.8 gallons/1,000 Ib
COD 30,699 mg/1
17.11 lb/1,000 Ib
TOC 9,216 mg/1
5.13 lb/1,000 Ib
Phenol 12,713 mg/1
7.1 lb/1,000 Ib
214
-------
FIGURE IV-37
BISPHENOL A
RECYCLE HCI
t^o
h-1
U-l
ACETONE
PHENOL
RECYCLE PHENOL
1
<
1
REACTORS
HCL
r
STILL
1
— >
<
L/L
SEP.
L
-»
w
HCI
RECOVERY
f~
I
4STEWATER
-» STILL
I
HEAVY
ENDS
1
1
EXCESS PHENOL AND ISOMERS
'FLAKE BISPHENOL
-^LIQUID BISPHENOL
CRYSTALLIZER
WATER
WASTEWATER
BISPHENOL A
*• WASTEWATER
LIQUID
BISPHENOL
SEPARATOR
MAKE-UP WATER
-------
The high concentration of phenol produces an inhibitory effect
and interferes with the BODj> measurement. The organic
contaminants in the waste water are mainly phenol, bisphenol, and
organic solvent. Incomplete separation of the aqueous and
organic phases in the decanter causes the high loss of organics
into the waste water. Organic vapor escaping from the final
evaporator also contributes a significant amount of contaminants.
To define BADCT and BATEA, a steam stripper should be required to
recover and recycle these organic contaminants in the two major
waste streams. The specification and the estimated economics of
a steam stripper have been presented in the discussion of
Aniline.
The total process water usage of this process is approximately
0.25 pounds per pound of bisphenol-A, while the gross cooling
water usage is about 197 pounds per pound of product.
The U.S. Bisphencl-A capacity and estimated economics are
presented in Tables IV-57 and IV-58.
216
-------
Producer
Dow
General Electric
Monsanto
Shell
Union Carbide
Table IV-57
U.S. Bisphenol-A Capacity
Location
Midland, Mich.
Mt. Vernon, Ind.
St. Louis, Mo.
Houston, Texas
Marietta, Ohio
Estimated Capacity*
MM Ib/yr
58
25
30
100
25
TOTAL
*As of mid-1969. Reported by Chemical Profiles 7/1/69.
Shell is reportedly expanding to 100 MM Ib/yr by 1/1/71,
and Dow is reportedly planning a new 100 MM Ib/yr plant
for Freeport, Texas due in 1972.
217
-------
Table IV-58
Estimated Economics for Bisphenol-A
(20 MM Ib plant)
Total Fixed Capital = $1.9 MM
Estimated Operation Cost
-------
SUBCATEGQRY C
Product_ Process
Caprolactam Oxidation of Cyclohexane
Caprolactam is produced in the BecJcman process by the addition of
hydroxylamine sulfate to cyclohexanone, which is derived from
cyclohexane. The basic chemical equations are given below:
H3BO3 H2NOH-HSOU
C6H1.2 + 02 __^ C6H11.0 «^. ~" C6H1JINOH
Cyclohexane Oxygen Cyclohexanone Cyclohexanone Oxime
or Air
H2S04
CH(CH2)5CONH + (NHU) 2SO«
"•*• Caprolactam Ammonium Sulfate
A process flowsheet is shown in Figure IV-38. Feed and recyled
cyclohexane are mixed with air in an oxidation reactor in the
presence of boric acid, which minimizes adipic acid production.
The oxidation is carried out at approximately 150 psig and 160°C.
The gaseous effluent is scrubbed to separate unreacted
cyclohexane from what is essentially nitrogen. The liquid
effluent is flashed with water and separated into an organic
phase and an aqueous catalyst phase, which is then sent to a
catalyst recovery unit. The organic phase is essentially a
mixture of unreacted cyclohexane, cyclohexanone, and
cyclohexanol. This mixture is first distilled to recover
unreacted cyclohexane and followed by saponification and
fractionation to separate cyclohexanone from cyclohexanol, which
is then converted to cyclohexanone by denydrogenation.
The hydroxylamine sulfate is obtained from ammonium nitrates and
sulfur dioxide. Ammonia gas and air are fed to a converter where
ammonia is burned at about 700°C in the presence of a catalytist
and converted to disulphonate by contacting with ammonium
carbonate and sulfur dioxide in series. The disulphonate is then
hydrolyzed to hydroxylamine.
By addition of cyclohexanone to hydroxylamine sulfate,
cyclohexanone oxime is first produced and rearranged in nearly
quantitative yield tc Caprolactam in the presence of concentrated
sulfuric acid. The product is neutralized, and the ammonium
sulfate solution is extracted with benzene to recover the lactam
product and discharged to a concentration and recovery step.
The major water pollution sources in this process are the draw-
off s from catalyst recovery unit, saponification and wash tower,
and the final product purification step. The contaminants in the
waste stream are small amounts of diacids formed during the
oxidation step, sodium salts, and unrecovered intermediate
products. The characteristics of the waste water obtained from
the plant survey are summarized in the following tabulation:
219
-------
FIGURE IV-38
CAPROLACTAM
RECYCLE CYCLOHEXANE
AIR
XANE
i
A OFF GAS
4
^ , !
^ tlXIUAHUN * " J
^ REACTORS
RECYCLE CATALYST
I WATER
r~
FLASH
1
WATER
CATAl
RECO\
i
YST
fERY
t
STILL
WASTEWATER
CYCLOHEXANONE
SAPONIF.
& WASH
TOWER
(NH4)2 CO3
A (WON.! A
AIR
PURE CAPROLACTAM
TO NITRITE
REACTOR
WASTEWATER
-------
Plant 1 Plant 2
Flow 1,334 gallons/1,000 Ib 2,500 gallons/1,000 Ib
COD 358 mg/1
4.0 lb/1,000 Ib N.A.
BODS 147 mg/1
1.64 lb/1,000 Ib 11.2 lb/1,000 Ib
TOC 109 mg/1
1.22 lb/1,000 Ib N.A.
Since it is deemed unfeasible to reduce RWL of this process by
any in-process modification, the RWL presented in the preceding
tabulation can be considered as standard for BADCT and BATEA.
Several other commercial routes to caprolactam are available, and
process highlights of each route are summarized in the following
paragraphs.
In the Toyo Rayon process, nitrosylchloride is first manufactured
by reacting ammonia gas with air at 700°C and atmospheric
pressure using platinum-rhodium gauze as a catalyst, then with
concentrated sulfuric acid, and finally with hydrogen chloride.
The nitrosylchloride gas mixture is then reacted with cyclohexane
to give the cyclohexane oxime hydrochloride. The reaction is
carried out in the liquid phase, using the visible light emitted
by mercury lamps to induce the photonitrosation. Subsequently,
cyclohexanone oxime hydrochloride is treated with oleum to
produce a sulfuric acid solution of caprolactam, which is then
purified by a series of purification steps.
The Snia Viscosa process is based on the nitrosation of
hexahydrobenzoic acid with sulfuric acid in oleum. The feed
toluene is oxidized with air and then hydrogenated over a
palladium catalyst to form hexahydrobenzoic acid. Caprolactam is
then formed by reacting hexahydrobenzoic acid with
nitrosyl sulfuric acid, which is prepared by bubbling N2O3_ into
the cyclohexane carboxylic acid dissolved in oleum.
The other route (referred to as the Caprolactone Process)
produces caprolactam without any ammonium sulfate by-product.
Caprolactone is first produced by oxidation of cyclohexanone with
peracetic acid, which is produced by acetaldehyde oxidation. The
resulting Caprolactone is distilled under vacuum and reacted with
ammonia at high pressure to form caprolactam, which is purified
using conventional distillation techniques.
Although many processes exist for caprolactam production, the
only process used coirmercially in the U.S. as shown in Table IV-
59 is the Beckmann process. The relative economics for the
Beckmann, Caprolactone and Toyo Rayon processes are summarized in
221
-------
Table IV-60 which shows that, the Beckmann has the lowest
investment cost.
Table IV-59
Caprolactam Capacity
(MM Ib.)
Company
Al1ied Chemical
Columbia N1PRO
Dow Badische
DuPont
Union Carbide
TOTAL
Location
Hopewel1, Va.
Augusta, Ga.
Freeport, Texas
Beaumont, Texas
Taft, La.
1972
300
kk
90
50
19
534
300
150
176
shut down
shut down
626
Process
Beckmann
Beckmann
Beckmann
N i t rocyc1ohexane
Caprolactone
222
-------
Table IV-60
Estimated Economics for Caprolactam
(150-MM-lb. plant; 1972 construction)
TOTAL FIXED CAPITAL
Process
Beckmann
Caprolactone
Toyo Rayon
S MM
37.4'
39.82
40.0
Investment includes cyclohexanone
and oximation.
Investment includes peracetic acid
and caprolactone units.
PRODUCTION COST
C/lb. caprolactam
Raw mater i a 1 s
Ut i 1 i t ies
Labor
Mai ntenance
(67-, ISBL + 3% OSBL)
Overhead
(45% of ma int. & labor)
Taxes and insurance
(1.5% of inv.)
Depreciation (10 yr.)
TOTAL
By-product credit
NET
Beckmann
1I.431
1.60
0.58
1.20
0.80
0.38
18.49
4.44
14.05
Caprolactone
10. 712
1.91
0.40
1.28
0.76
0.41
2.66
18.13
6.22
11.91
Tovo Ravon
9. 14
2.25
0.36
1.28
0.74
0.41
2.66
16.84
1.58
15.26
Includes cyclohexane (0.88 Ib. at 3.3c/lb.), NH3 (1 Ib. at 2 e/lb.) and
oleum (1.7 Ib. at $36/ton). Ammonium sulfate credit at $23/ton.
Includes cyclohexane (1.0 Ib. at 3.3c/lb.) and acetaldehyde (0.62 Ib. at
S.Oe/lb.). Acetic acid credit at 6c/lb.
Includes cyclohexane (0.95 Ib. at 3.3
-------
SUBCATEGORY C
Product E£2£®ss
Long Chain Alcohols Ethylene Polymerization
Long-chain alcohols are manufactured from ethylene in the
presence of Ziegler catalysts. The process begins by reacting
aluminum metal with ethylene and hydrogen to form triethyl
aluminum (TEA). Ethylene is added to this compound at high
pressures to give trialkyl aluminum compounds, which are then
oxidized with dry air to aluminum trialkoxides. These are
hydrolyzed by sulfuric acid to primary alcohols having an even
number of carbon atoms. The basic chemical equations are
summarized as follows:
3C2H4 + 1 1/2H2 + Al _+, (C2H5) 3A1
Ethylene Hydrogen Aluminum Triethyl Aluminum
(C2H5)3A1 + nC2H4 —* Rlv ,
Triethyl Ehtylene Triethyl Aluminum
Aluminum
R.-O ^
+°2 __* R^-0 - Al
Aluminum Trialkoxides
H2SO4
R10H + R20H + R30H + A12 (SO4) 3
> ~ - ~ ~
H2O Long-Chain Alcohols Alum
•A simplified flow diagram is shown in Figure IV-39. An atomized
aluminum powder is first activated in a non-aqueous slurry media
and next hydrogenated with dry hydrogen gas under pressure to
give diethyl aluminum hydride. The hydride is then contacted
with ethylene to produce TEA. Approximately two moles of TEA are
recycled to the hydrogenator and one mole goes to the
polymerization step. Recycle TEA solvent and aluminum are
separated by means of a centrifuge.
In the polymerization section, TEA is reacted with ethlyene under
pressure to make trialkyl aluminum, which is then oxidized to
produce alkoxides. A non-aqueous solvent such as toluene is
circulated and recycled in this section. In the hydrolysis
section, the alkoxides are hydrolyzed with sulfuric acid and
water to yield alcohols and a solution of alum and water. The
224
-------
FIGURE IV -
LONG CHAIN ALCOHOL
TRIALKYL ALUMIN.
TO OLEFINS REC.
ETHYLENE
SOLVENT (TOLUENE)
ALUMINUM POWDER
tx}
en
AIR
RECYCLE AL, SOLVENT AND TEA
CRUDE ALCOHOLS
r~
UtlANl .
ALUMINUM SOLVENTT
WASTEWATER
fc.
~w
CAUSTIC WASH
STEAM
TO VAC.
ALCOHOLS
SPLITTER
ALCOHOLS
DEHYDRATOR
WASTEWATER
STEAM
JET
\-
WASTEWATER
•ALCOHOL PRODUCTS
VACUUM DISTILLATION
—* RESIDUE
DECANT.
\
WATER
WATER WASH
DECANT.
\
WASTEWATER
WASTEWATER
-------
alum solution is separated from the alcohols in a decanter. The
sulfuric acid residue 'is first neutralized with dilute caustic
solution and next washed with hot water to remove sodium sulfate.
In both the neutralization and wash steps, the alcohols are
separated from the aqueous phase in decanters.
The crude alcohols are then dehydrated and fractionated in a
series of distillation columns to obtain pure alcohol products.
Steam jets are used to produce vacuum in the stills.
The major water pollution sources in this process are the draw-
off s from decanters and the condensate of the steam jets.
Depending upon the desired concentration of the alum solution
recovered, the cycle of decanter draw-off waters, and the modes
of condensing ejected steam, the volume of waste water per unit
production will vary.
Straight-chain alcohols are also obtained by the oxo reaction
starting from straight-chain - olefins and by direct oxidation of
normal paraffins. Producers of long-chain synthetic alcohols in
the U.S. are presented in Table IV-61.
Table IV-61
U.S. Long-Chain Alcohol Capacity
Producer
Continental
Ethyl
Shell
Shell*
Location
Lake Charles, La.
Houston, Tex.
Houston, Tex.
Geismar, La.
Union Carbide Texas City, Tex.
1965
Capacity
MM lbs/y_r.
Type of
Alcohol
Process
100.00
50.00
50.00
100.00
Primary
Primary
80% Primary
20% Secondary
80% Primary
Z i eg 1 e r
Ziegler
Oxo
Oxo
20% Secondary
^0.00 Secondary Oxidation
Raw Material
Ethylene
Ethylene
Cracked wax
Cracked wax
n-paraff ins
»Due on stream in 1966.
Source: Oil. Paint, and Drug Reporter. August 26, 1965.
226
-------
SUBCATEGORY C
Product
Tetraethyl Lead Addition of Ethyl Chloride to
Lead in Sodium - Lead Alloy
Over 90 percent of all tetraethyl lead is produced by some
version of a conventional forty-year-old batch process in which
an alkyl halide reacts with sodium-lead alloy. The reaction,
occur ing in a horizontal autoclave provided with a reflux
condenser to recover any vaporized alkyl halide, yeilds a mixture
of TEL, salt, and lead. The reaction, carried out at 60 psig and
70°C, is given below:
4PbNa + 4C2H51 — * (C2H5)4Pb + 3Pb
Sodium Lead Ethyl~~chloride TEL Lead
Alloy
The product mixture is fed batchwise to a still, where the
tetraethyl lead is separated from the by-product lead and sodium
chloride by direct steam stripping. The tetraethyl lead and
stripping steam are condensed and sent to a decanter, where
tetraethyl lead is drawn off as a bottoms stream. The upper
aqueous layer in the decanter, containing unreacted ethyl
chloride and dissolved organic by-products, is discharged into a
process ditch.
The salty sludge bottoms from the still are sent to a lead
recovery unit, and the centrate is combined with the supernatant
from the TEL decanter before being discharged into a settling
basin for final recovery of solid lead.
The process flow sheet is shown in Figure IV- 40.
Since recovery of by-product lead is considered an integral part
of the TEL manufacturing process, the effluent from the settling
basin is considered as the waste water source of the process.
The waste water characteristics obtained from the plant visit are
shown in the following tabulation:
Flow 12,000 gallons/1,000 Ib
COD 1, 100 mg/1
110 lb/1,000 Ib
BODS 40 mg/1
4 lb/1,000 Ib
TOC 56 mg/1
5.6 lb/1,000 Ib
The high amount of waste water is due mainly to the nature of
batch processes, which require a large quantity of water in
cleaning up the reactor between reaction batches. Another cause
of high water use is the vent-gas scrubber at the "lead" recovery
227
-------
NaPb
ETHYL CHLORIDE
tx
K)
STEAM
LEAD, WATER
SODIUM CHLORIDE
FIGURE IV- 40
TETRAETHYL LEAD
WASTEH/ATER
FUEL ANTIKNOCK COMPOUND
-------
unit. The intermittent, dosage of "still-aids" such as soap or
iron to control the plating out of lead on the still walls, as
well as unrecovered ethyl chloride, TEL, and metallic lead, all
contribute to the high chemical oxygen demand.
In defining levels of control technology, it is suggested that
recycling of the aqueous layer in the decanter to reduce fresh
water usage, and consequently the amount of waste water
discharged, can be considered for BPCTCA. BADCT and BATEA should
have a steam stripper for effective recovery of unreacted ethyl
chloride and product TEL from the stream prior to their discharge
into the settling basin.
An alternate process, which is based on the electrolysis of an
alkyl Grignard reagent, is used by only one company in the world.
This involves a totally different approach and offers at least
three advantages: 1) it gives higher product yields; 2) it does
not make by-product lead, hence eliminating the inefficient
recovery and recycle of metallic lead; and 3) it can produce TEL
as well as alkyl lead compounds. The first processing step is
the preparation of the Grignard reagent. Agitated propane-cooled
reactors receive metallic magnesium that reacts exothermically
with fresh and recycled alkyl halide in the presence of an
electrolytic solvent consisting of a mixture of ethers such as
tetrahydrofuran and diethylenegylcol dibutyl ether. The yield of
alkylmagnesium halide is over 98%. The effluent of the
electrolysis cell is sent to a stripper, where a separation of
alkyl halide and alkyl lead is performed.
The U.S. tetraethyl lead capacity and the estimated economics for
tetraethyl lead production are presented in Tables IV-62 and Iv-
63.
229
-------
DuPont
Ethyl
Houston Chem.
Nalco Chem.
Total
Table IV-62
U.S. Tetraethy? Lead Capacity
Plant Location
Antioch, Calif.
Deepwater, N.J.
Baton Rouge, La.
Houston, Texas
Beaumont, Texas
Houston, Texas
Est. 1970 Capacity
(Million Pounds/Year)
340
390
100
_65_
895
Table IV-63
Estimated Economics for Tetraethyl Lead
(40. MM Ib. plant)
Total Fixed CaptiaI=$IO.O MM
Estimated Operation Cost
Ethyl chloride
Sodium
Lead (17<5/lb.)
Utilities
Labor and overhead
Capital charges
Total
Cost,
tf/lb. TEL
4.9
3.8
11.4
1.5
1.6
31.5
230
-------
SUBCATEGORY_C
Product
Coal Tar Products Coal Tar Distillation
Coal tar is a mixture of many chemical compounds (mostly
aromatic) which vary widely in composition. The process of coal
tar distillation separates these fractions into commercially
valuable products.
In the plant visited, crude coke-oven tar is fractionally
distilled into solvent, carbolic oil, road tar, creosote, and
pitch fractions. These products are then purified or further
fractionated into fine products. The processes of coal tar
distillation, anthracene refining, pitch forming, and naphthalene
refining, together with their associated waste water sources, are
briefly described in the following paragraphs; simplified process
diagrams are presented in Figures IV-41 through IV-44.
Crude coke-oven tar and dilute caustic solution are fed into a
dehydration column. The vapor stream taken overhead from the
column is condensed, and water is removed from the solvent and
discharged to a sewer line. The liquid stream is sent then to a
vacuum still and tc a series of fractionators where crude
carbolic oil, road tar, creosote, and pitch fraction are
generated. There are two steam jets associated with the
distillation columns; the condensates of these jets contain
organic contaminants and are the major water pollution sources.
In the anthracene refining process, creosote is first washed with
water in a crystallizer, and the creosote anthracene slurry is
passed through filters and centrifuges to produce crude
anthracene. The crude product is then sent to a crystallizer,
where furfural is used to purify the product. Refined solid
anthracene is obtained after solid separation and drying steps.
The liquid streams from the second-stage purification units are
collected for furfural recovery. The acqueous stream discharged
from the first-stage purification unit and the condensate of the
steam jet associated with the furfural recovery unit are major
waste water sources. The liquid pitch from tar distillation is
cooled by direct contact with water and then dried to form the
final product. The contact cooling water is another major waste
water source.
The first step in naphthalene refining is extraction of topped
carbolic oil with a caustic solution. The bottom layer in the
extractors is the by-product of carbolate. The upper aqueous
layer in the extractors is sent to a series of stills where
naphthalene and intermediate products are generated. The only
water pollution source is the condensate of the steam jets which
are used to produce vacuum in the naphthalene stills.
End-of-pipe treatment and in-plant abatement have been achieved:
segregation of clean water from process waste water, replacement
of barometric condensers with indirect condensers, installation
231
-------
STEAM
C & W
LIGHT OIL
FIGURE IV-41
COAL TAR DISTILLATION
SOLVENT
LIGHT CREOSOTE
LIGHT CREOSOTE
WATER
PITCH
-------
FIGURE IV-42
ANTHRACENE REFINING
CREOSOTE
WATER
DIRECT
CONTACT
SOLIDS
SEPARATION
& DRYING
REFINED
ANTHRACENE
VfASTEWATER
WASTEWATER
-------
FIGURE IV-43
EXTRACTION AND NAPHTHALENE REFINING
INTERMEDIATE
NAPHTHALENE
C & W
C & W
EXTRACTED TOPPED CARBOLIC OIL
.<£ TOPPED
CARBOLIC
OIL
INTERMEDIATE
NAPHTHALENE
DISTILLATION
DILUTE
CAUSTIC
NAPHTHALENE
DISTILLATION
NAPHTHALENE
JETS
STEAM
WATER
WASTEWATER
FURNACE
CARBOLIC OIL RESIDUE
-------
FIGURE IV-44
PITCH FORMING
WATER
t-> LIQUID PITCH FROM
S TAR DISTILLATION
DIRECT COOLING
DRYING
HASTEWATER
LOADING
I
FORMED
PITCH
-------
of phenol recovery units, etc. These modification have resulted
in a low RWL.
The characteristics of waste water obtained from the plant survey
are shown in the following tabulation:
Coal Tar Pitch
Pi s t i 1 1 at ion
405.3 gallons/ 1,000 gallons 126.1 gallons/1,000 Ib
COD 2,570 mg/1 61 mg/1
8.68 lb/1,000 gallons 0.061 lb/1,000 Ib
BOD 5 833 mg/1
~ 2.81 lb/1,000 gallons N.A.
TOC 3,010 mg/1
10.16 lb/1,000 gallons N.A.
The historical data provided by the plant indicate that pitch
forming has a waste flow of 200 gal/1,000 Ib of product, with
0.13 pounds of COD while the naphthalene refining has a waste
flow of 408 gal/1,000 Ib of product, with 0.86 pounds of COD.
Although there is a variation between the survey and the
historical data, the raw waste loads derived from the above-
mentioned abatements can be considered as" representative of
BPCTCA control technology of eacn individual process. However,
standards for BATEA and BADCT should require that the remaining
barometric condensers be converted to indirect condensers. Thus,
the quantities of waste water from the processes of coal tar
distillation and naphthalene refining can be reduced, although
RWL may not be correspondingly reduced.
236
-------
SUBCATEGQRY P
Product Process ___
Dyes and Pigments Batch Manufacture
The manufacture and use of dyes and pigments constitute an
important part of modern chemical technology. Because of the
variety of products that require a particular material to give
maximum coverage, economy, opacity, color, durability, and
desired refluctance, manufacturers now offer many hundreds of
distinctly different dyes and pigments. Usually dyes are
classified according to both the chemical makeup and the method
of application. The manufacturers look at dyes from the chemical
aspect, and arrange and manufacture them in groups, usually of
like chemical conversions, while the users of dyes group them
according to the methods of application. Table IV-6U lists the
principal types of dyes by application classification, and Table
IV-65 by chemical arrangement. The selected pigments and their
corresponding production figures are presented in Table IV-66.
The raw materials for the manufacture of dyes are mainly aromatic
hydrocarbons, such as benzene, toluene, naphthalene, anthracene,
pyrene, and others. These raw materials are almost never
directly useful in dye synthesis. It is necessary to convert
them to a variety of derivatives, which are in turn made into
dyes. These derivatives are called intermediates. However, the
industries which utilize either raw materials or intermediates to
produce final-product dyes are all subcategorized as the dye
industry.
Because of the large number of compounds that are required, often
in limited amounts, most dyes, if not all, are manufactured in
batches. Since the purpose of this project is to investigate
process-related waste water generation sources rather than to
examine detailed unit processes/operations of manufacturing
processes for each class of dyes/ pigments, a typical
manufacturing process for dyes is given to illustrate the waste
water sources.
A typical process flew sheet for manufacture of azo dyes is
presented in Figure IV-45. Raw materials (which include aromatic
hydrocarbons, intermediates, various acids and alkalies, and
solvents) are simultaneously or separately fed into the reactor,
where the reaction is carried out ordinarily at atmospheric
pressure. Because the reactions are exothermic, adequate
temperature control is required to avoid side reactions.
Temperature control is accomplished primarily by direct additon
of ice to the reaction tank, when the reaction is complete, the
dye particles salt out from the reaction mixture. The vent gases
taken overheads from the reactor are continuously passed through
a water scrubber before being discharged into the atmosphere.
The liquid effluent from the reactor is then sent to a plate-and-
frame filter press where the dye particles are separated from the
mother liquor. The mother liquor is either directly discharged
237
-------
FIGURE IV-45
DYES
VENT
Ol
0=
HYDRO CARBON
«ID OR ALKALIES
INTERMEDIATES
SOLVENT
SCRUBBER
BATCH
REACTOR
(DYE
SYNTHESIS)
ICE
WSTEWATER
FILTRATION
(FILTER PRESS)
WASTEWATER
DRYING
(DRUM DRYERS
OR TRAY OVENS)
BLENDING
AND
STANDARDIZATION
PRODUCT
WASTEWATER
FILTER PRESS
(METAL SALT RECOVERY)
I
->SLUDGE
WSTEWATER
-------
Table IV-6J*
U. S. Production of Dyes,
by Classes of Application, 1965
Sales
Production ,
Class of application 1,
000 Ib.
Total 207,193
Acid
Azoic dyes and components:
Azoic compositions
Azoic diazo components, bases
(fast color bases)
Azoic diazo components, salts
(fast color salts)
Azoic coupling components
(naphthol AS and derivatives)
Basic
Di rect
Di sperse
Fiber-reactive
Fluorescent brightening agents
Food, drug, and cosmetic colors
Mordant
Solvent
Sulfur
Vat
All other
20,395
2,100
1,558
2,835
3,172
10,573
36,080
15,51**
1,586
19,420
2,923
4,745
9,837
18,648
57,511
296
Quantity,
1 ,000 Ib.
189,965
18,666
2,043
1,310
2,646
2,429
9,553
33,663
13,522
1,558
18,284
2,736
4,246
8,930
17,471
52,439
469
Value,
$1 ,000
292,284
39,025
3,968
2,057
2,683
4,669
23,907
50,970
32,878
6,744
34,516
10,238
5,706
15,351
9,960
48,728
884
Unit
value,
n i u c1*
HP r 1 n S
I c- 1 i u . y
1.54
2.09
1.94
1.57
1.01
1.92
2.50
1.51
2.43
4.33
1.89
3.74
1.34
1.72
0.57
0.93
1.88
Source: Synthetic Organic Chemicals. U. S. Tariff Commission
239
-------
Table IV-65
U.S. Production and Sales of Dyes,
by Chemical Classification, 1964
Chemical class;
Total
Anthraquinone
Azo, total
Azoic
Cyanine
Indigo id
Ketone imine
Methine
Nitro
Oxazine
Phthalocyanine
Quinoline
StiIbene
Sulfur
Thiazole
Triarylmethane
Xanthene
All other
Production,
1,000 Ib.
184,38?
41,661
57,897
8,787
373
5,729
731
1,074
720
172
1,987
637
18,488
17,776
462
5,607
1,312
20,974
Quantity,
1,000 Ib.
178,273
^0,675
57,367
7,399
362
6,144
782
974
679
144
1,868
519
17,640
17,268
480
5,312
: 737
19,923
Value,
$1,000
264,023
66,889
96,579
12,149
1,113
3,302
1,614
3,367
1,258
601
4,800
1,658
29,166
9,798
1,043
12,682
3,473
14,531
Unit value
n^r 1 k £
1.48
1.64
1.68
1.64
3.07
0.54
2.06
3.46
1.85
4.17
2.57
3.19
1.65
0.57
2.17
2.39
4.71
0.73
Source: Synthetic Organic Chemicals. U.S. Tariff Commission
In 1965 total dye production increased
207 million Ib.
240
12.5% to
-------
Table IV-66
Production or Shipment of Selected Pigments in the United States, 1958 and 19&3
Short tons
Pigments
Titanium pigments, composite and pure (100%)
White lead, except white lead in oil:
Basic lead carbonate
Basic lead sulfate
Zinc oxide pigments:
Lead-free zinc oxide
Leaded zinc oxide
Lithopone
White extender pigments:
Barites, etc. (excluding whiting)
Whiting (calcium carbonate)
Color pigments and toners (except lakes), chrome colors:
Chrome green
Chromium oxide green
Chrome yellow and orange
Molybdate chrome orange
Zinc yellow (zinc chromate)
Iron oxide pigments
Colored lead pigments:
Red lead
Litharge
Iron blues (Prussian blue, Milori blue, etc.)
Blacks:
Bone black
Other blacks (carbon black)
1958
403,867
14,527
130,075
23,127
1963
555,211*
162,281*
12,281*
28,393
3,907
4,820
22,365
5,675
6,005
62,923
23,311
121,698
4,265
823,625
158,773
2,867
6,473*
26,620*
) 9,400*
73,251
25,780
93,958
5,030
11,471
1,138,500*
Source: Chemical Statistics Handbook. 5th ed., Statistical Summary 4,
Manufacturing Chemists'Association, Washington, D.C., August, 1961.
*1964
241
-------
into sewers or sent, to another filter press to recover some of
the metal salts. The filter cake is first washed with compressed
air while still in the press. The moist cake is discharged into
shallow trays which are placed in a circulating air drier,
wherein the moisture is removed at temperatures between 50 and
120°C. Vacuum driers and drum driers may also be used. The
dried dye is ground and mixed with a diluent, such as salt, to
make it equal in color strength to a predetermined standard.
Dilution is necessary because batches differ in their content of
pure dye. Uniformity is assured by dilution to a standard
strength.
The great majority of dyes and pigments are manufactued by the
typical process flow diagram described. However, the manufacture
of some special dyes or pigments may require more or fewer
processing steps. For example, in the manufacture of alkali-blue
pigment, the process requires a steam ejector to produce vacuum
for the batch reactors. The barometric condenser is then used to
condense the exhaust steam. In the manufacture of Direct Blue 6
dye, the filter cake is not washed but merely freed from the
adhering liquid by air drying.
The major water pollution sources of this process are the mother
liquor from the filter press, the intermittent reactor clean-up
waters, the draw-off from the .vent gas scrubber, and the
housekeeping cleaning waters. The data obtained from the plant
survey are summarized in the following tabulation. Multiple data
were collected at one of the plants, and these data were
subjected to the analysis for probability of occurrence. The
results of probability analysis are also shown in the tabulation.
Summary of Survey Wastewater Data
Product Samgle_I..jD.._ Flow COD
BOD5
TOC
gal/1,000 Ib lb/1,000 Ib lb/1,000 Ib
(mg/1) (mg/1)
1; Dye Sample 1 13,700
2; Dye Sample 2 13,700
2; Dye 21,050
3; Dye 10% 95,069
occurrence
50% 95,069
Occurrence
1,075
(9,400)
652
(5,700)
175
(997)
50
(63)
1,850
(2,331)
220
(1,920)
126
(1,100)
59
(337)
5
(6)
79
(100)
lb/1,000 Ib
(mg/1)
450
(3,945)
269
(2,350)
60
(360)
40
(51)
790
(995)
242
-------
90* 95,069 3,700 156 1,580
Occurrence (4,662) (197) (1,991)
4; Pigment 124,000 4,925 1,470 819
(4,764) (1,422) (792)
Because of frequent changing of feed materials and desired
products, dyemaking requires large amounts of water and of
cleaning aids (such as detergent and bleach) to clean up reactors
and filter presses on each reaction cycle. Chemical reactions
involved are often exothermic and require strict temperature
control. Due to the necessity of rapid cooling in order to avoid
side reactions, direct cooling with ice, in addition to jacket
cooling, is commonly practiced, and this also contributes a
significant amount of waste water. While the high organic
loading in the waste water is primarily the result of incomplete ^
crystallization and separation of dye products from the mother
liquor, organic losses and cleaning aids from clean-up operations
also contribute. Different from other organic chemical
industries, jacket cooling water is required to be discharged
into sewers to dilute the waste water to be treated.
Reuse or recycle of waste water from this type of process is
deemed unfeasible, because the waste waters are contaminated with
many different salts, metal ions, and a high intensity of color,
which will in turn contaminate the product.
Phase I Subcategory D raw waste load data base for organic dyes
and pigments is not considered to be adequate to support effluent
limitations guidelines for this segment of the industry.
Coverage of Subcategory D segment has been expanded in the Phase
II study. Effluent limitations guidelines will be proposed in
the Phase II proposed regulation for organic dyes and pigments.
243
-------
SECTION V
WASTE CHARACTERIZATION
In order to develop production based effluent limitations and
performance standards (expressed as unit weight of pollutant per
unit weight of product), it is first necessary to define a raw
waste load (RWL) for the process. Appropriate reduction factors
can then be applied to the RWL to establish the desired
production based restrictions.
The choice of the specific pollution parameters for which
restrictions are to be recommended is to a large extent governed
by existing conventions which have been established within the
water pollution control field. Although it would be desirable to
identify the specific chemicals which are present in the waste
water streams associated with the organic chemicals industry,
many of these would be present in the waste water from only a few
processes so that the development of generalized restrictions
which are applicable to large categories would not be possible.
For this reason conventional general parameters related to oxygen
demand, toxicity, turbidity, color, and taste were examined
during the course of this study.
The waste water associated with each process was differentiated
according to whether it was considered as contact waste water or
non-contact waste water. It is impossible to equitably define
production based RWL for the noncontact water streams. This is
caused by the fact that these streams are always associated with
a number of different processes with no equitable means available
for allocating the pollutants which are present.
In a typical chemical process plant, utility functions such as
the supply of steam and cooling water are set up to service
several processes. Boiler feed water is prepared, and steam is
generated in a single boiler house. Noncontact steam used for
surface heating is circulated through a closed loop whereby
varying quantities are made available for the specific
requirements of the different processes. The condensate is
nearly always recycled to the boiler house, where a certain
portion is discharged as blowdown.
Noncontact cooling waters are also supplied to several processes.
The system generally is either a closed loop utilizing one or
more evaporative cooling towers, or a once-through system with
direct discharge.
The amounts of blowdcwn from boilers and cooling towers are not
directly related to individual processes but depend rather on the
design of the particular plant utility system. Although
noncontact steam and cooling water requirements were presented
for the processes which have been examined, the quantities of
blowdown associated with utility recycle loops cannot be
correlated back to individual processes. Similarly, the amounts
244
-------
of waste brine and sludge produced by ion exchange and water
treatment systems cannot be allocated among the individual
processes within a plant*
The quantities of pollutants such as dissolved solids, suspended
solids, alkalinity, and other parameters which are associated
with the noncontact streams and water treatment equipment were
not included in the calcualtion of the production based RWL for
each process. Subsequently, no production based limitations or
standards are recommended for these parameters at this time.
Studies currently underway will establish bases for development
of effluent limitations for noncontact waste waters at a future
date. Instead, contact process waste water streams formed the
basis for all RWL calculations included in this study.
The RWL data to be presented in this section was based on past
historical data supplied by some of the manufacturers surveyed as
well as actual data obtained by sampling.
The RWL for each process was calculated by taking 24 hour
composite samples of the contact process waste water streams.
The pollutant concentrations obtained from the analysis of these
samples were multiplied by the associated waste water flow during
the same 24 hour period to give pollutant generation rate as Ib
per day. These generation rates were divided by the
corresponding production to provide a series of production based
RWL's.
It should be noted that many of the processes examined generate
nonaqueous wastes. These may be liquid or semi-liquid materials,
such as tars, or gaseous materials, such as by-product
hydrocarbon vapors. As such, these wastes are normally burned as
auxiliary fuel or are disposed of in some way that is unrelated
to the contact process waste water. These materials were not
included as part of the RWL calculated for the processes
examined.
The RWL for a specific process module is based on the actual
production rate of the principal product and the measured contact
process waste water flow. Co-products are not included in the
RWL calculation unless they have specific waste waters asscoiated
with their own purification or processing. An example of this
situation is the RWL associated with butadiene as a co-product of
ethylene manufacture. In this case, butadiene purification has a
specific waste water flow and loading; therefore, a separate RWL
has been defined.
Dissolved oxygen demanding material was found to be the major
pollutant associated with production operations in this industry.
Standard Raw Waste Loads (SWRL), expressed as average or median
values, have been developed for the industrial subcategories.
Four major parameters were considered:
1. Process Wastewater Flow Loading
(expressed as liters/kKg and
245
-------
gal/1,000 Ibs of product)
2. BOD5 Raw Waste Loading
(expressed as kg BOD5/kkg and
Ib BO 5/1,000 Ib of product)
3. COD Raw Waste Loading
(expressed as kg COD/kkg and
Ib COD/1,000 Ib of product)
U. TOC Raw Waste Loading
(expressed as kg TOC/kkg and
Ib TOC/1,000 Ib of product)
The RWL data relating to individual manufacturing processes were
first grouped according to the sutcategory in which the process
is assigned. The data for the processes within each subcategory
were then plotted as pollutant raw waste loading versus contact
process waste water flow loading. These plots are shown in the
following figures:
Subcategory A
BOD5> vs. Flow (Figure V-1)
COD vs. Flow (Figure V-2)
TOC vs. Flow (Figure V-3)
Subcategory B
BOD5_ vs. Flew (Figure V-U)
COD vs. Flow (Figure V-5)
TOC vs. Flow (Figure V-6)
Subcategory C
BOD5 vs. Flow (Figure V-7)
COD vs. Flow (Figure V-3)
TOC vs. Flow (Figure V-9)
Subcategory D
BODjj vs. Flow (Figure V-*10)
COD vs. Flow (Figure V-11)
Since both the loading (ordinate) and flow {abscissa) are
expressed on a production basis, dividing the loading by the flow
gives a slope which may be expressed as a concentration. For
orientation, reference lines of constant concentration have been
drawn diagonally across each of the plots. Relating a specific
data point to one of these lines provides a convenient estimate
as to the raw waste concentration.
The five manufacturing processes examined in Subcategory A were
described in the previous section. No clear range or SRWL can be
defined for this category. This may partially be caused by the
fact that external runoff, washings, and contaminated spray
cooling water amount to a significant portion of the waste water
flow in each case.
246
-------
One of the major difficulties in obtaining meaningful RWL data
for Subcategory A processes is the fact that a large portion of
the waste water comes from sources which are difficult to sample
or where pollutant loadings result from contact with chemicals on
the ground. Unlike other process sutcategories where specific
process pipes or sewers can be used to sample and measure all
process flows, Subcategory A waste waters are intermittently
dumped directly into open ditches or common sewers within the
process area. In some cases, Subcategory A waste waters flow by
gravity to holding tanks where batch treatment is provided; in
other cases, they are discharged directly into the overall plant
treatment system.
There is also a question as to whether the continuous water
washes are truly representative of the process or are
necessitated by a specific feed impurity (ethyl benzene) or
nonaqueous absorbent (Benzene, Toluene, Xylene recovered by
solvent extraction) used by the particular manufacturers sampled.
When compared with the range of pollutant loadings presented for
the other subcategories, it is apparent that those from
Subcategory A are generally lower. The RWL for Subcategory A
products-processes are summarized in Table V-1. The ethyl
benzene process was determined to be a Subcategory B type process
due to the washing step in purifying the product.
The individual process RWL data for Subcategory B are plotted in
Figures V-4 through V-6. General increasing trends between
pollutant RWL and flow RWL appear to exist within the category.
The BOD5 RWL for 13 Subcategory B processes generally falls in a
concentration range of 100 to 500 mg/1. Loadings vary from 0.09
to 7.0 Ib COD/1,000 Ib of product. The corresponding range of
flows increases from 50 to 3,000 gal/1,000 Ib of product. It
should be noted that two of the processes in Subcategory B
ethylene dichloride (EDC) manufactured by the chlorination of
ethylene, and vinyl chloride monomer (VCM) manufactured by the
purolysis of EDC product contact process waste waters which are
not amenable to the BODjj test. This was caused by objectionable
conditions related to the high concentrations of wastes. In such
cases, the wastes may still be degraded biologically, but require
dilution with other less concentrated wastes or noncontact
cooling water.
The COD RWL concentrations for 16 Subcategory B processes are
bewteen 100 and 5,000 mg/1. Loadings vary from 0.5 to 21.5
lb/COD/1,000 Ib of product within the same range of flows as
presented for the BOD.5 RWL.
The TOC RWL concentrations for 16 Subcategory B processes are
generally between 100 and 2,000 mg/1. TOC loadings vary from a
minimum of 0.2 to a maximum of 40 Ibs TOC/1,000 Ib of product.
247
-------
Product/Proces s
BTX Aromatics
(Hydrotreatment)
BTX Aromatics
(Solvent Extractin)
Cyclohexane
Vinyl Chloride
Mean Value
Table V-l
Summary of Raw Waste Load Data
Subcategory A - Nonaqueous Processes
Flow
Vkkg
114.0
504.0
No Discharge
2;004.0
873.0
gal/1000 Ib
13.6
60.4
240
105.0
BODS
kg/kkg (lb/1000 Ib)
0.10
GOD
kg/kkg (lb/1000 Ib)
0.31
0.10
0.12
0.22
KJ
-p*
OO
-------
FIGURE V-l
RELATIONSHIP BETWEEN BOD RWL AND FLOW RWL FOR SUBCATEGORY A
10' i— 10'
10U
_ 10"
- 10-1
,0-2 L_ ,0-2
10'
LEGEND:
1. BTX AROMATICS
2. ETHYL BENZENE
• SURVEY SAMPLING DATA
102
10*
R0« ML (GAL. / 103 LBS PRODUCT)
103 104
FLO* R»L (LITER/103 KILOGRAM PRODUCT)
249
-------
FIGURE V-2
RELATIONSHIP BETWEEN COD RWL AND FLOW RWL FOR SUBCATEGORY A
10'
10°
10°
B
&
10-'
ID-2 L 10-2
f
f
'
•1
X
^
*y
/
/
x
/
/
/
/
/
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x
/
2
/
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/
/
/
/
/
/
/
/
/
^
f
^
f
f
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S
*3
/
/
/
7
7
/
/
/
/
/
/
/
/
f
'
/
/
/
/
/
ND:
1. BTX ABQUATICS
2. ETHYL BENZENE
3. VINYL CHLORIDE
• SURVF.Y SAMPLING DATf
,
o' io2 to3 u
FLO* MIL (GAL./ IO3 LBS. PRODUCT)
II 1 1 1 1 1
IO2 IO3 IO4
FLO* RB. (LITER/103 KILOGRAM PRODUCT)
250
-------
FIGURE V-3
RELATIONSHIP BETWEEN TOC RWL AND FLOW RWL FOR SUBCATEGORY A
io' r- 10'
100
&
is
O
t~-
§
10-
— 10-
io-2L- 10-
10'
/
LEGEND:
I. BTX AROMATICS
2. ETHYL BENZENE
3. VINYL CHLORIDE
• SURVEY SAMPLING DATA
102 103
FLO* R»L (GALS/103 LBS. PRODUCT)
I I
10 3 10
FLO* RKL ( LITER/103 KILOGRAM fRj3U(.,')
251
-------
There is no definite correlation Between the BOD5 and COD RWL
within Subcategory B. COD/BOD5 ratios generally vary between 2/1
and 10/1. This is urderstandable since there is still a wide
variety of specific chemicals which may be present in the waste
waters from this process category.
The wide spread in RWL data obtained for Subcategory B has led to
the establishrnnet of two subcategories designated as BJ and B2.
The individual products, processes, and associated RWL~asllocated
to each Subcategory are indicated in Table V-2. It can be seen
that the average flows and RWL for the two subcategories conform
to the general relationship of increased loadings being
associated with increased flows.
The individual process RWL data for Subcategory C are plotted in
Figures V-7 through V-9.
As with Subcategory B, there appears to be an increasing trend
between BOD5 RWL and flow RWL. This relation is not nearly so
definitive for the COD and TOG parameters.
The BOD5 RWL for the Subcategory C processes generally fall in a
concentration range of 3,000 to 1-0,000 mg/1. Loadings vary from
1.3 to 125 Ib BOD5/1,000 Ib of product. The corresponding range
of flows increases from 30 to 3,000 gal/1,000 Ib of product.
The COD RWL data for the Subcategory C processes are between
10,000 and 50,000 mg/1. Loadings vary from 5.5 to 385 Ib
COD/1,000 Ib of product within the same range of flows as
presented for the BODjj RWL.
The TOC RWL concentrations for the Subcategory C processes are
generally between 3,000 and 15,000 mg/1. TOC loadings vary
between 1.5 and 150 lb/1,000 Ib of product. An envelope drawn
around the TOC data commensurate with the BPCTCA technology is
shown in Figure 1-7.
As with Subcategory B, there is no definite correlation between
the BOD5 and COD RWL within this Subcategory. COD/BOD5 ratios
generally vary between 3/1 and 5/1. However, some specific
processes vary widely outside this range.
There is quite a wide spread in the RWL obtained for the
processes surveyed within Subcategory C. For this reason, four
subcategories designated as Cl, C2, C3 and C4 have been
established. The specific products, processes, and associated
RWL assigned to each Subcategory are indicated in Table V-3.
The individual process RWL data for the_ batch plants in
Subcategory D are plotted in Figures V-10 and V-11. As with
Subcategory A, the data are insufficient to establish any clear
relationships between pollutant loading and flow. The ranges of
loadings and flows are quite wide. This is caused mainly by the
highly variable product mix and the inclusions of contact cooling
and cleaning waters.
252
-------
TABLE V-2
Summary of Raw Waste Load Data by Subcategory Group
Subcategory B - Processes with Process Water Contact as Steam Diluent
or Absorbent
Flow
B]^ Product - Processes
Ethyl benzene
Ethylene and Propylene
Butadiene (from ethylene
Methai.ol
Acetone
Vinyl Acetate
Formaldehyde
Ethylene Oxide
Ethylene Dichloride
Vinyl Chloride (from ethylene dichloride)
Methyl Amines
BI Mean Value
82 Product - Processes
Acetaldehyde (from ethanol)
Butadiene (from n - butane)
Acetylene
Styrene
Bo Mean Value
gal/1000 Ib.
38
355
203
50
175
28
131
74
96
336
439
175
1600
1160
561
1733
1264
Flow
Liters/kkg
317
2961
1693
417
1460
234
1093
617
800
2802
3661
1460
13,344
9,674
4,679
14,453
10,541
BOD5
kg/kkg (lb/1000 Ib)
0.13
0.35
0.63
0.49
0.26
0.04
0.7
0.48
0.38
1.12
,96
,92
,00
COD
kg/kkg(Ib/lOOOlb)
1.86
2.36
2.04
0.94
1.10
0.13
6.48
4.84
7.66
12.8
4.0
48
23
95
74
1.75
3.85
253
-------
FIGURE V-4
RELATIONSHIP BETWEEN BOD RWL AND FLOW RWL FOR SUBCATEGORY B
10?
10'1
10-2
10'
)'
10"
io-i
in-2
*"^
CS.X 10
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LEGEND
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ACETALDEHYDE FROM ETHANOL
OXIDATIVE-DEHYOROGENATION
ACETONE FROM 1 PA DEHYDROGENAT
BUTADIENE FROM C2H4
EXTRACTIVE DISTILLATION
BUTADIENE FROM N-BUTANE
DEHYDROGENATION (HOUDRY)
STYRENE FROM E. B.
ETHYLENE FROM C2H5
ETHYLENE FROM LPG
ETHYLENE FROM NAPHTHA
ETHYLENE FROM CjHj
ETHYLENE OXIDE
METHANOL
METHYL AMINES
ACETYLENE
SURVEY SAMPLING DATA
90% OCCURRENCE
HISTORICAL PLANT DATA
50% OCCURRENCE
10% OCCURRENCE
i 7
*
ON
FLO* RKL (GAL/103 LB PRODUCT)
103
10*
FLO* RUIL (LITER/103 KILOGRAM PRODUCT)
254
-------
FIGURE V-5
RELATIONSHIP BETWEEN COD RWL AND FLOW RWL FOR SUBCATEGORY
ID2
10'
ID-' L
1.
2
3
4
5
B
7.
a
102
to'
1—
C3
d
O
cc
o_
CD
en
is
s
CQ
or
Q
8 ,.
10-1
LEGEND
ACETALDEHY OE FROM ETHANOL 9. ETHYLENE FROM C3HB «
OXIOATIYE-DEHYDROGENATION ,„ ETHUE|E ^
ACETONE FROM IPA DEHYDROGENATION ,, „„„,,,„,
II. M t 1 n A NU L
BUTADIENE FROM C2H4 )2 M[mi AM,NES I
EXTRACTIVE DISTILLATION n SCEmENE
BUTADIENE FROM N-BUTANE
DEHYDROGENATION (HOUDRY)
STYRENE FROM E. B.
ETHYLENE FROM C2H5 l5' EDC FRDM C2H4
ETHYLENE FROM LPG i6' yal rm EDC
ETHYLEU FROM NAPHTHA
10 •
-Jt
r
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» SURVEY SAMPLING DATA
90« OCCURRENCE
HISTORICAL PLANT DATA
' 508 OCCURRENCE
IDS OCCURRENCE
/
/
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(
1
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ID1 102 103
FLO* RWL (GAL/103 LBS PRODUCT)
I | 1
10 2 10 3 ID4
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x
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f
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FLO* R»L (LITER/103 KILOGRAM PRODUCT)
255-
-------
TOC RWL (KILOGRAM TOC/103 KILOGRAM PRODUCT)
TOC RWL (LBS TOC/103 LBS PRODUCT)
Ol
O)
33
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-
-------
TABLE V-3
Summary of Raw Waste Load Data by Subcategory Group
Subcategory C - Aqueous Liquid Phase Reaction Systems
Flow
Flow
C1 Product - Processes
Coal Tar (pitch Forming)
Acetic Acid
Acrylic Acid
Ethylene Glycol
Terephtalic Acid
gal/1000 Ib.
500
475
584
186
1iters/kkg
1,043
4,170
3,962
4,871
1,551
BOD5
kg/kkg (lb/1000 Ib)
COD
0.35
0.74
0.34
0.82
kg/kkg (lb/1000 Tb)
0.06
0.78
1.64
8.76
1.72
Cl Mean Value 374
C2 Product - Processes
Acetaldehyde (ethylene and oxygen) 61
Phenol and Acetane (cumene process)* 280
0X0 Chemicals 420
Coal Tar (distillation) 400
Caprolactam 1,300
C2 Mean Value 492
C3 Product - Process
Acetaldehyde (ethylene and air) 90
Aniline 190
"isphenol A * 67
Dimethyl Terephthalate 270
C3 Mean Value 154
C4 Product - Processes
Acrylates 2,856
P - Cresol * 1,291
Methyl Methacrylate 200
Terephthalic Acid (nitric acid Process) 659
Tetraethyl Lead 12,000
C4 Mean Value
3,401
3,119
509
2,335
3,503
3,336
10,842
4,103
751
1,585
E59
2,252
1,284
23,819
10,767
1,668
5,496
100,000
28,366
0.56
1.9
5.6
3.2
2.8
1.6
3.03
26.6
24.4
25.5
47
123
45
59
68.5
2.59
5.8
11.0
4.25
8.7
4.0
6.75
44
21.2
17.1
38.2
30.1
118
256
386
104
110
195
* Phenols raw waste load - 10 kg/1000 kkg (lb/1000 Ib)
257
-------
BOD R»L (KldffiRAW BOD /I03 KILOGRAM PRODUCT)
10 ! 10 3 104 10s 106
FLO« R»L (LITEfVlO3 KILOGRAM PRODUCT)
° <=f =, °. "& '& 'S.
I 1
1
ID' to2 io3 io4
FLOW R»L (GAL/103 LBS PRODUCT)
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6 TETRAETHYL LEAD
7 PHENOL/ACETCNE
8 ACETALDEHYDE
9 ACETIC ACID
10 ANILINE
12 ETHYLENE GLYCOL
• SURVEY SAMPLING DATA
5 ACRYLATES
1
3
x>
I
3 DIMETHYL TEREPHTHALATE
, 1 METHYL METHACRYLATE
2 TEREPHTHALIC ACID ' 'POLYMER GRADE' '
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COD R»L (KILOGRJW COO/IO3 KILOGRWI PRODUCT)
<£,
COD R«L (LB COO/103 LBS PRODUCT)
\
\
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S 5
I I
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VI
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z
o
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a
70
-------
FIGURE V-9
RELATIONSHIP BETWEEN TOC RWL AND FLOW RWL FOR SUBCATIGORY D
103 -
102
10'
10-2 L
10"
103
in7
10'
10"
10-1
in ?
- LEGEND
1 M
2 T
3 D
4 T
5 A
7 P
8 A
11 B
12 E
14 0
15 A
16 C
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/
/
16
p
|
^3
/
^
/
X
/I
/
^
/
/
/
/
/
/
/
/
/
y
/
-^
/
r7
/
^
y
/
/
x
/
/
/
//
-'
IIP
10'
102
FLOK ML (GAL/103 LBS PRODUCT)
10"
10?
FLOW °WL (LITER/103 KILOGRAM PRODUCT)
260
-------
It should be noted that the loadings shown for Subcategory D are
based on the entire production from the batch plant. The RWL for
Subcategory D were subjected to analysis for probability of
occurrence and are summarized in Table V-4. Subcategory D
(organic dyes and pigments) has been deleted from Phase I and
included under Phase II coverage of the organic chemicals
manufacturing industry.
261
-------
Table V-4
Subcategory D - Batch and Semi Continuous Processes
Summary of Raw Waste Load Data
JD. - Batch Organic Azo Dyes
Flow
@5Q% occurrence
Mean Value
liters/1000 kg (gal/1000 Ib)
793,826 (95,069)
114,395 (13,700)
175,768 (21,050)
361,329 (43,273)
BOD COD TOC
kg/1000 kg or lb/1000 Ib
79
220
59
119
1,850
1,075
175
1,033
790
450
60
433
-o
262
-------
FIGURE V-10
RELATIONSHIP BETWEEN BOD RWL AND FLOW RWL FOR SUBCATEGORY D
104 r 104
LEGEND
1 PLASTICIZERS
2 DYES-PIGMENTS
• SURVEY SAMPLING DATA
102
1,02
10'
100
10'
102
I03
FLO« R«L (GAL/103 LBS PRODUCT)
105
10
FLO* R«L (LITER/103 KILOGRAM PRODUCT)
263
-------
FIGURE V-ll
RELATIONSHIP BETWEEN COD RWL AND FLOW RWL FOR SUBCATEGORY D
10-
10"
• "s io3
i|
CO
i
0=
Q
S
•f*-
,*.^>/
/
s
LEGE
2
/
y
jr.
X
/
f
NO:
DYES -
SURVEY
/
/
1/1
/
'
/
f
f
PIGMENTS
SAMPLING DATA
/
/
/
^
,
/
'
103
/
x^
/
/
/
/
/
J\ 2
/ 1
^ 1
1
•
2 <
f'
f
/
/
/
/
y
/
/
i/
/
^
/I
i
i
x
/
/
'
/•
/
2
2
/
/
/
/
/
/
,
/
/
> '
/
/
'
ID4 105 10B 107
FLO* R»L (GAL./ I03 LBS PRODUCT)
l i . J _ J_^ 1
FLOW RWL (LITER/103 KILOGRAM PROOUCU
264
-------
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
An extensive literature review resulted in the selection of
twenty five parameters which were examined during the field data
collection program. These parameters are listed in Table VI- 1,
and all field data are summarized in Supplement B. Miscelleneous
raw waste loads are also presented in Table VI-2 and Table VI-3.
The rationale and justification for pollutant subcategorization
within the above groupings will be explored. This discussion
will provide the basis for selection of parameters upon which the
actual effluent limitations were postulated and prepared. In
addition, particular parameters were selected for discussion in
the light of current knowledge as to their limitations from an
analytical as well as from an environmental standpoint.
Pollutants observed from the field data as present in sufficient
concentrations to interfere with, be incompatible with, or pass
thru inadequately treated in a publicly owned works are discussed
in Section XII.
Pollutants of Significance
Parameters of pollutional significance for which effluent
limitations were developed in the organic chemicals industry are
the major organic parameters of BOD5, COD and TOC.
n Demand JBOD}_
Biochemical oxygen demand (BOD) is a measure of the oxygen
consuming capabilities of organic matter. The BOD does not in
itself cause direct harm to a water system, but it does exert an
indirect effect by depressing the oxygen content of the water.
Sewage and other organic effluents during their processes of
decomposition exert a BOD, which can have a catastrophic effect
on the ecosystem by depleting the oxygen supply. Conditions are
reached frequently where all of the oxygen is used and the
continuing decay process causes the production of noxious gases
such as hydrogen sulfide and methane. Water with a high BOD
indicates the presence of decomposing organic matter and
subsequent high bacterial counts that degrade its quality and
potential uses.
Dissolved oxygen (DO) is a water quality constituent that, in
appropriate concentrations, is essential not only to keep
organisms living but also to sustain species reproduction, vigor,
and the development of populations. Organisms undergo stress at
265
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reduced D.O. concentrations that make them less competitive and
able to sustain their species within the aquatic environment.
For example, reduced DO concentrations have been shown to
interfere with fish population through delayed hatching of eggs,
reduced size and vigor of embryos, production of deformities in
young, interference with food digestion, acceleration of blood
clotting, decreased tolerance to certain toxicants, reduced food
efficiency and growth rate, and reduced maximum sustained
swimming speed. Fish food organisms are likewise affected
adversely in conditions with suppressed DO. Since all aerobic
aquatic organisms need a certain amount of oxygen, the
consequences of total lack of dissolved oxygen due to a high BOD
can kill all inhabitants of the affected area.
If a high BOD is present, the quality of the water is usually
visually degraded by the presence of decomposing materials and
algae blooms due to the uptake of degraded materials that form
the foodstuffs of the algal populations.
266
-------
Table VI-1
List of Pollutants Surveyed for the Organic Chemicals Industry
Chemical Oxygen Demand (COD)
Biochemical Oxygen Demand (BOD5)
Total Organic Carbon (TOG)
Total Suspended (Nonfilterable)
Solids (TSS)
Oil and Grease
Ammonia Nitrogen
Total Kjeldahl Nitrogen (TKN)
Phenols
Cyanide, Total
Color
Sulfate
PH
Acidity
Alkalinity
Total Dissolved (Filterable)
Solids
Chloride
Hardness - Total
Total Phosphorus
Calcium - Total
Magnesium - Total
Zinc -* Total
Copper - Total
Iron - Total
Chromium - Total
Cadmium - Total
Cobalt - Total
Lead - Total
267
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cop
Chemical oxygen demand (COD) provides a measure of the equivalent
oxygen required to oxidize the organic material present in a
waste water sample, under acid conditions with the aid of a
strong chemical oxidant, such as potassium dichromate, and a
catalyst (silver sulfate). One major advantage of the COD test
is that the results are available normally in less than three
hours. However, one major disadvantage is that the COD test does
not differentiate between biodegradable and nonbiodegradable
organic material. In addition, the presence of inorganic
reducing chemicals (sulfides, etc.) and chlorides may interfere
with the COD test.
&%Standards Methods for the Examination of Water and Wastewater,
the principal reference for anlaytipal work in this, f jeld^
cautions that aromatic compounds, and straight-chain alphatic
compounds^ both prevalent in the organic chemicals industry^ are
not completely oxidized during, the COD test.. The addition of
silver sulfate, a catalyst, aids in the oxidation of the
straight-chain alcohols and acids but does not affect aromatic
hydrocarbons. The exact extent of this gartial oxidation has not
been documented Jin the literature^
COD RWL data for the four subcategories is presented in Figures
V-2, V-5, V-8, and V-ll. A summary of the concentration range is
presented below:
Subcategory COD RWL^Range
mg/1
A 100-10,000
B 200-5,000
C 10,000-50,000
D 1,000-10,000
Typical COD values for municipal waste waters are between 200
mg/1 and 400 mg/1.
Effluent limitations guidelines were not established for the COD
pollutant parameter for BPCTCA and New Sources although its use
is not precluded if a suitable correlation with BODS is
established,
TOC
Total organic carbon (TOC) is a measure of the amount of carbon
in the organic material in a waste water sample. The TOC
analyzer withdraws a small volume of sample and thermally
oxidizes it a 150C. The water vapor and carbon dioxide is
monitored. This carbon dioxide value corresponds to the total
inorganic value. Another portion of the same sample is thermally
oxidized at 950°C, which converts all the carbonaceous material;
this value corresponds to the total carbon (carbonates and water
vapor) from the total carbon value*
268
-------
The TOC value is affected by any one or more of the following:
1. One possible interference in the measurement occurs
when the water vapor is only partially condensed.
Water vapor overlaps the infrared absorption band
of carbon dioxide and can therefore inflate the
reported value.
2. The sample volume involved in the TOC analyzer is
so small (approximately 40 microliters) that it can
easily become contaminated, with dust, for example.
3. Industrial wastes from the organic chemicals
industry with low vaporization points may vaproize
before 150C and therefore be reported as inorganic
carbon.
TOC RWL data for Subcategories A, B, and C are shown in Figures
V-3, V-6, and V-9. A summary of the concentration ranges are
presented below:
Subcategory TOC RWL Range
mg/1
A 100-3,000
B 100-2,000
C 3,000-5,000
Typical values for municipal waste waters range between 50 and
250 mg/1.
Effluent limitations were not established for the TOC parameter,
although its use is not precluded if a suitable correlation with
BOD5 or COD is established.
Other Significant Pollutants
Suspended solids, oil, ammonia nitrogen, total Kjeldahl nitrogen,
phenols, dissolved solids, cyanide, sulfate, and color, in
general were present in smaller concentrations. Effluent
limitations are specified for TSS in all subcategories.
Phenols are limited for the cumene process, bisphenol and p-
cresol since concentration of phenols are considerably high for
these process. Other pollutant parameters which are discussed in
this section but no effluent limitations established are not
present in all subcategories, and are generally controled at the
source. These may, however, present environmental problems where
water quality standards dictate and may ultimately be limited.
Total Suspended Solids
Suspended solids include both organic and inorganic materials.
The inorganic components include sand, silt, and clay. The
organic fraction includes such materials as grease, oil, tar,
animal and vegetable fats, various fibers, sawdust, hair, and
269
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various materials from sewers. These solids may settle out
rapidly and bottom deposits are often a mixture of both organic
and inorganic solids. They adversely affect fisheries by
covering the bottom of the stream or lake with a blanket of
material that destroys the fish-food bottom fauna or the spawning
ground of fish. Deposits containing organic materials may
deplete bottom oxygen supplies and produce hydrogen sulfide,
carbon dioxide, methane, and other noxious gases.
In raw water sources for domestic use, state and regional
agencies generally specify that suspended solids in streams shall
not be present in sufficient concentration to be objectionable or
to interfere with normal treatment processes. Suspended solids
in water may interfere with many industrial processes, and cause
foaming in boilers, or encrustations on equipment exposed to
water, especially as the temperature rises. Suspended solids are
undesirable in water for textile industries; paper and pulp;
beverages; dairy products; laundries; dyeing; photography;
cooling systems, and power plants. Suspended particles also
serve as a transport mechanism for pesticides and other
substances which are readily sorbed into or onto clay particles.
Solids may be suspended in water for a time, and then settle to
the bed of the stream or lake. These settleable solids
discharged with man's wastes may be inert, slowly biodegradable
materials, or rapidly decomposable substances. While in
suspension, they increase the turbidity of the water, reduce
light penetration and impair the photosynthetic activity of
aquatic plants.
Solids in suspension are aesthetically displeasing. When they
settle to form sludge deposits on the stream or lake bed, they
are often much more damaging to the life in water, and they
retain the capacity to displease the senses. Solids, when
transformed to sludge deposits, may do a variety of damaging
things, including blanketing the stream or lake bed and thereby
destroying the living spaces for those benthic organisms that
would otherwise occupy the habitat. When of an organic and
therefore decomposable nature, solids use a portion or all of the
dissolved oxygen available in the area. Organic materials also
serve as a seemingly inexhaustible food source for sludgeworms
and associated organisms.
Turbidity is principally a measure of the light absorbing
properties of suspended solids. It is frequently used as a
substitute method of quickly estimating the total suspended
solids when the concentration is relatively low.
Oil and Grease
Oil and grease exhibit an oxygen demand. Oil emulsions may
adhere to the gills of fish or coat and destroy algae or other
plankton. Deposition of oil in the bottom sediments can serve to
exhibit normal benthic growths, thus interrupting the aquatic
food chain. Soluble and emulsified material ingested by fish may
270
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taint the flavor of the fish flesh. Water soluble components may
exert toxic action on fish. Floating oil may reduce the re-
aeration of the water surface and in conjunction with emulsified
oil may interfere with photosynthesis. Water insoluble
components damage the plumage and costs of water animals and
fowls. Oil and grease in a water can result in the formation of
objectionable surface slicks preventing the full aesthetic
enjoyment of the water.
Oil spills can damage the surface of boats and can destroy the
aesthetic characteristics of beaches and shorelines.
Ammonia
Ammonia is a common product of the decomposition of organic
matter. Dead and decaying animals and plants along with human
and animal body wastes account for much of the ammonia entering
the aquatic ecosystem. Ammonia exists in its non-ionized form
only at higher pH levels and is the most toxic in this state.
The lower the pH, the more ionized ammonia is formed and its
toxicity decreases. Ammonia, in the presence of dissolved
oxygen, is converted to nitrate (N03.) by nitrifying bacteria.
Nitrite (NOJ) , which is an intermediate product between ammonia
and nitrate, sometimes occurs in quantity when depressed oxygen
conditions permit. Ammonia can exist in several other chemical
combinations including ammonium chloride and other salts.
Nitrates are considered to be among the poisonous ingredients of
mineralized waters, with potassium nitrate being more poisonous
than sodium nitrate. Excess nitrates cause irritation of the
mucous linings of the gastrointestinal tract and the bladder; the
symptoms are diarrhea and diuresis, and drinking one liter of
water containing 500 mg/1 of nitrate can cause such symptoms.
Infant methemoglobinemia, a disease characterized by certain
specific blood changes and cyanosis, may be caused by high
nitrate concentrations in the water used for preparing feeding
formulae. While it is still impossible to state precise
concentration limits, it has been widely recommended that water
containing more than 10 mg/1 of nitrate nitrogen (NOJ3-N) should
not be used for infants. Nitrates are also harmful in
fermentation processes and can cause disagreeable tastes in beer.
In most natural water the pH range is such that ammonium ions
(NH4+) predominate. In alkaline waters, however, high
concentrations of un-ionized ammonia in undissociated ammonium
hydroxide increase the toxicity of ammonia solutions. In streams
polluted with sewage, up to one half of the nitrogen in the
sewage may be in the form of free ammonia, and sewage may carry
up to 35 mg/1 of total nitrogen. It has been shown that at a
level of 1.0 mg/1 un-ionized ammonia, the ability of hemoglobin
to combine with oxygen is impaired and fish may suffocate.
Evidence indicates that ammonia exerts a considerable toxic
effect on all aquatic life within a range of less than 1.0 mg/1
271
-------
to 25 mg/1, depending on the pH and dissolved oxygen level
present.
Ammonia can add to the problem of eutrophication by supplying
nitrogen through its breakdown products. Some lakes in warmer
climates, and others that are aging quickly are sometimes limited
by the nitrogen available. Any increase will speed up the plant
growth and decay process.
Phenols
Phenols and phenolic wastes are derived from petroleum, coke, and
chemical industries; wood distillation; and domestic and animal
wastes. Many phenolic compounds are more toxic than pure phenol;
their toxicity varies with the combinations and general nature of
total wastes. The effect of combinations of different phenolic
compounds is cumulative.
Phenols and phenolic compounds are both acutely and chronically
toxic to fish and other aquatic animals. Also, chlorophenols
produce an unpleasant taste in fish flesh that destroys their
recreational and commercial value.
It is necessary to limit phenolic compounds in raw water used for
drinking water supplies, as conventional treatment methods used
by water supply facilities do not remove phenols. The ingestion
of concentrated solutions of phenols will result in severe pain,
renal irritation, shock and possibly death.
Phenols also reduce the utility of water for certain industrial
uses, notably food and beverage processing, where it creates
unpleasant tastes and odors in the product.
In natural waters the dissolved solids consist mainly of
carbonates, chlorides, sulfates, phosphates, and possibly
nitrates of calcium, magnesium, sodium, and potassium, with
traces of iron, manganese and other substances.
Many communities in the United States and in other countries use
water supplies containing 2000 to 4000 mg/1 of dissolved salts,
when no better water is available. Such waters are not
palatable, may not quench thirst, and may have a laxative action
on new users. Waters containing more than 4000 mg/1 of total
salts are generally considered unfit for human use, although in
hot climates such higher salt concentrations can be tolerated
whereas they could not be in temperate climates. Waters
containing 5000 mg/1 or more are reported to be bitter and act as
bladder and intestinal irritants. It is generally agreed that
the salt concentration of good, palatable water should not exceed
500 mg/1.
Limiting concentrations of dissolved solids for fresh-water fish
may range from 5,000 to 10,000 mg/1, according to species and
272
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prior acclimatization. Some fish are adapted to living in more
saline waters, and a few species of fresh-water forms have been
found in natural waters with a salt concentration of 15,000 to
20,000 mg/1. Fish can slowly become acclimatized to higher
salinities, but fish in waters of low salinity cannot survive
sudden exposure to high salinities, such as those resulting from
discharges of oil-well brines. Dissolved solids may influence
the toxicity of heavy metals and organic compounds to fish and
other aquatic life, primarily because of the antagonistic effect
of hardness on metals.
Waters with total dissolved solids over 500 mg/1 have decreasing
utility as irrigation water. At 5,000 mg/1 water has little or
no value for irrigation.
Dissolved solids in industrial waters can cause foaming in
boilers and cause interference with cleaness, color, or taste of
many finished products. High contents of dissolved solids also
tend to accelerate corrosion.
Specific conductance is a measure of the capacity of water to
convey an electric current. This property is related to the
total concentration of ionized substances in water and water
temperature. This property is frequently used as a substitute
method of quickly estimating the dissolved solids concentration.
Cyanide
Cyanides in water derive their toxicity primarily from
undissolved hydrogen cyanide (HCN) rather than from the cyanide
ion (CN~). HCN dissociates in water into H* and CM- in a pH-
dependent reaction. At a pH of 7 or below, less than 1 percent
of the cyanide is present as CN^; at a pH of 8, 6.7 percent; at a
pH of 9, 42 percent; and at a pH of 10, 87 percent of the cyanide
is dissociated. The toxicity of cyanides is also increased by
increases in temperature and reductions in oxygen tensions. A
temperature rise of 10°C produced a two- to threefold increase in
the rate of the lethal action of cyanide.
Cyanide has been shown to be poisonous to humans, and amounts
over 18 ppm can have adverse effects. A single dose of 6, about
50-60 mg, is reported to be fatal.
Trout and other aquatic organisms are extremely sensitive to
cyanide. Amounts as small as .1 part per million can kill them.
Certain metals, such as nickel, may complex with cyanide to
reduce lethality especially at higher pH values, but zinc and
cadmium cyanide complexes are exceedingly toxic.
When fish are poisoned by cyanide, the gills become considerably
brighter in color than those of normal fish, owing to the
inhibition by cyanide of the oxidase responsible for oxygen
transfer from the blood to the tissues.
273
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Color is objectionable from an aesthetic standpoint and also
because it interferes with the transmission of sunlight into
streams, thereby lessening photosynthetic action. Color is
measured against a platinum cobalt standard which is basically a
yellow-brown hue. This color shading was developed to simulate
domestic waste waters. The use of the procedure on highly
colored industrial waste waters is subject to question. During
Phase II of this study, a more intensive investigation will be
made as to the most appropriate procedure for reporting color.
Color RWL data for Subcategories B and C are generally not a
major consideration. However, in Subcategory D color is as high
as 50,000 Pt-Co-units for pigment and dye waste waters. There
were two major reasons for not trying to set limitations for
Subcategory D:
1. Sufficient RWL data were not collected during the sampling
program. (This will be remedied during Phase II of this
project).
2. Scarcity of treatment data on color removal presented major
technological questions concerning levels of color removal
for various types of dyes and pigments. This situation can be
be remedied during Phase II of our study by a concentrated
study of the color removal of various waste water unit
processes. However, there is recent evidence that carbon
filters can be a satisfactory treatment agent for many
color problems.
Many of the specific comments made previously regarding dissolved
solids* are directly applicable to these parameters of minimal
significance. Concentrations of calcium, magnesium, chorides and
hardness are generally higher for Subcategory C because of
extensive recycling. In addition, particular processes in
Subcategory C product Nad as a product of reaction, e.g.
tetraethyl lead production. Subcategory D waste waters likewise
have high concentrations as a result of inorganic chemical
additions.
Phosphorus
During the past 30 years, a formidable case has developed for the
belief that increasing standing crops of aquatic plant growths,
which often interfere with water uses and are nuisances to man,
frequently are caused by increasing supplies of phosphorus. Such
phenomena are associated with a condition of accelerated
eutrophication or aging of waters. It is generally recognized
that phosphorus is not the sole cause of eutrophication, but
there is evidence to substantiate that it is frequently the key
element in all of the elements required by fresh water plants and
is generally present in the least amount relative to need.
Therefore, an increase in phosphorus allows use of other, already
present, nutrients for plant growths. Phosphorus is usually
described, for this reasons, as a "limiting factor."
274
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When a plant population is stimulated in production and attains a
nuisance status, a large number of associated liabilities are
immediately apparent. Dense populations of pond weeds make
swimming dangerous. Boating and water skiing and sometimes
fishing may be eliminated because of the mass of vegetation that
serves as an physical impediment to such activities. Plant
populations have been associated with stunted fish populations
and with poor fishing. Plant nuisances emit vile stenches,
impart tastes and odors to water supplies, reduce the efficiency
of industrial and municipal water treatment, impair aesthetic
beauty, reduce or restrict resort trade, lower waterfront
property values, cause skin rashes to man during water contact,
and serve as a desired substrate and breeding ground for flies.
Phosphorus in the elemental form is particularly toxic, and
subject to bioaccumulation in much the same way as mercury.
Colloidal elemental phosphorus will poison marine fish (causing
skin tissue breakdown and discoloration). Also, phosphorus is
capable of being concentrated and will accumulate in organs and
soft tissues. Experiments have shown that marine fish will
concentrate phosphorus from water containing as little as 1 ug/1.
pH, Acidity and Alkalinity
Acidity and alkalinity are reciprocal terms. Acidity is produced
by substances that yield hydrogen ions upon hydrolysis and
alkalinity is produced by substances that yield hydroxyl ions.
The terms "total acidity" and "total alkalinity" are often used
to express the buffering capacity of a solution. Acidity in
natural waters is caused by carbon dioxide, mineral acids, weakly
dissociated acids, and the salts of strong acids and weak bases.
Alkalinity is caused by strong bases and the salts of strong
alkalies and weak acids.
The term pH is a logarithmic expression of the concentration of
hydrogen ions. At a pH of 7, the hydrogen and hydroxyl ion
concentrations are essentially equal and the water is neutral.
Lower pH values indicate acidity while higher values indicate
alkalinity. The relationship between pH and acidity or
alkalinity is not necessarily linear or direct.
Waters with a pH below 6.0 are corrosive to water works
structures, distribution lines, and household plumbing fixtures
and can thus add such constituents to drinking water as iron,
copper, zinc, cadmium and lead. The hydrogen ion concentration
can affect the "taste" of the water. At a low pH water tastes
"sour". The bactericidal effect of chlorine is weakened as the
pH increases, and it is advantageous to keep the pH close to 7.
This is very significant for providing safe drinking water.
Extremes of pH or rapid pH changes can exert stress conditions or
kill aquatic life outright. Dead fish, associated algal blooms,
and foul stenches are aesthetic liabilities of any waterway.
Even moderate changes from "acceptable" criteria limits of pH are
deleterious to some species. The relative toxicity to aquatic
275
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life of many materials is increased by changes in the water pH.
Metalocyanide complexes can increase a thousand-fold in toxicity
with a drop of 1.5 pH units. The availability of many nutrient
substances varies with the alkalinity and acidity. Ammonia is
more lethal with a higher pH.
The lacrimal fluid of the human eye has a pH of approximately 7.0
and a deviation of 0.1 pH unit from the norm may result in eye
irritation for the swimmer. Appreciable irritation will cause
severe pain.
276
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Table VI-2
Miscellaneous RWL Loads for Subcategory B
Product
Flow
gal/1000 lb
Acetone via 1 PA
Butadiene via C4
Butadiene via 0^4
Styrene via E. B.
EDC via Direct Chlorination
Ethyl ene/Propylane via Pyrolysis
Ethylene Oxide
Methyl Amines
Acetylene
120
1,742
183
88
339
657
15.4
336
130
364
52.5
150
554
167
131
17.8
429
560
Phenol
mg/L
0.1815
18.5
0.01
0.024
0.02
2.0
0.13
0.006
6.78
0.36
2.36
5-59
8.25
7.24
0.048
0.154
0.031
0.76
lb/1000 lb
1.815x10"
0 . 2691
1.6xlO-5
1.8x10"'
6.3x10"'
0.011
2.0x10"'
1.7x10"'
7-33x10"'
1 . 08x10"'
1 . 03X10"5
0.007
0.038
0.01
5.3x10"'
2.3x10"'
1.12X10"1*"
3.55x10"'
mg/L
11.2
2.8
0.97
43.2
5907
4.2
0.5
1.7
6.44
19.6
< 0.5
3-9
2.2
1.4
< 0.5
5.6
7-9
5.6
NH3-N
lb/1000 lb
1. 12x10 "2
o . o4o4
1.47x10"'
0.0317
16.6
0,023
7.0x!0"5
4.62x10"'
6.96;;10"'
< 0.058 k
< 2.2x10";:
4.9x10"'
1.02x10"^
1.94x10"'
< 5.5X10"11
3.7X10"1*
2.82xlO"2
0.0262
mg/L
12.6
5.0
2.6
235
12,200
7.0
2.9
4.6
65.5
25.2
< 0.5
9.7
9.0
2.6
2.8
14
26.3
84
TKN
lb/1000 lb
0.0126
0.0728
4.02x10"'
0.172
34.4
0.0383
3.7xlO"4
0 . 0127
0.071
0.075 k
< 2.2x10
0.012
0.041
3.6x10"'
3 . 08x10"'
2.1x10"'
0.0941
0.3927
CN
mg/L lb/1000 lb
-
< 0.1 1.63x10"'
0.19 3.0x10";:
< 0.04 < 3.0x10"?
< 0.04 1.2x10
< 0.04 < 0.002
o . 046 i . Oxio"?
0.12 3.3x10
0.11 1.2xl0"jj
0.12 3.6x10";:
< 0.04 2.0x10"'
o . 043 5 • Oxio"?
0.055 2.6x10
-
0.44 4.8xlO"x
< o.o4 < 6.0x10
< 0. 04 <1. 42x10
0.312 1.46x10"'
Sulfate
mg/L
-
149
15.8
190
64
< l
503
78
649
120
73.6
280
0.98
1.5
510
5,4oo
< 1
280
lb/1000 lb
-
2.158
0.024
0 . 0142
0.18
< 0.0055
0.065
0.218
o . 7013
0.36
0.032
0.35,
4.5x10 '
2.13x10"'
0.56
0.81
1.309
mg/L
-
20.4
8.6
7.4
93
38
74
26
483
11.7
172
11
188
10.1
3-3
1.8
4.6
1.4
Oil
lb/1000 lb
-
0.2965
0.013
o . 0053
0.261
0.208
9.5x10"'
o . 0712
0.522
0.035
0.075
0.014
0.87
0.014
3.3x10"?
3.2x10
o . 0163
6.55x10"'
-------
00
Table VI-2
(continued)
"roduct
Acetone via 1 PA
Butadiene via C4
Butadiene via C.2H4
Styrene via E.B.
EDC via Direct Chlorination
Ethyl ene/Propylene via Pyrolysis
Ethylene Oxide
Methyl Amines
Acetylene
mg/L
-
1.93
31.5
0.77
3.50
0.66
0.544
0.09
1.30
5.5
1,469
0.6l
0.196
494
0.144
1.2
0.066
0.25
T-P
lb/1000 Ib
-
0.02795
5. 6x10 ~4
0.0098
o . 0036
7.0x!0"5
2 . 5xlO"4
1.41x10"'
0.017
0.64 ,
7.6x107
9-lxlO
0.686
l.SxlO-1*
2.37X10"1*
1.17xlO"3
mg/L
-
0.37
0.12
-
0.14
0.62
-
< 0.05
3.2
0.671
0.37
0.153
0.29
0.33
o.i4
0.2
Zn
lb/1000 Ib
-
5.34x!0"3
1.8x10-"
-
7.67x10
8.0xlO"5
-
< 5.6xlo"5
0.001^
2.9x107
4.6x107
T.ixioT;
4.1x10
3.6x10"^
2.1x10"'
i.
9.35x10"*
mg/L
-
0.273
0.17
0.17
0.36
0.21
0.24
0.14
0.14
0.15
0.08
0.19
0.1
0.76
1-25
0.4l
0.25
< 0.05
Cu
lb/1000 Ib
-
3.97xlO"3
2.6x!0"\
1.28X10"4
0.001
1.15x10"^
3.0xlo"5,
3.77xlo"4
1.48x1 or1*
4. 5x10 7
3.0x10"?
2.4xlO"J;
4 . 6x10
1.05xlO"3
1.38xlO~3
6.0x10"'
9.0X10"1*
i
< 2.3xlO~*
mg/L
-
45.1
5-6
0.65
0.5
0.5
1.06
3-4
1.22
3-8
1.17
0.83
0.64
0.62
1.5
1-33
3.38
0.4
Fe
lb/1000 Ib
-
0.655
8.5x10-3
4.8x10"%
1 . 52x10"'
2. 74x10 "5
1.4X10"4
9.42xlO"5
1. 32x10 "5
0.011^
5.1x10
0.001
2.95x10,
8 . 5x10"
1.65x10"?
2 . 0x10
0.0121
_,
l . 87x!0"5
mg/L
-
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.04
< 0.05
^.35
1.86
< 0.05
0.197
< 0.06
< 0.05
0.07
< 0.05
Cr
lb/1000 Ib
-
< 7.26xlO"6
4.0x10"?
< 1.5x10
< 2.74xlO"5
< l.Oxlo"5,
< 1.04x10
< 5. 44x10 "5
0.013^
8.2x10
< 6.0xlor?
9.1x10
< 7.7xlO"5
< 6-OxlO"14"
l.lxlO"5
i.
< 2.34xlO"4
mg/L
-
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.021
0.143
0.051
< 0.06
< 0.05
< 0.05
< 0.05
Cd
lb/1000 Ib
-
< 7. 46x10"**
< 7.6xlO"5
< 4.0x107
< 1.5x10
<2.74x!0"5
<1.0xlO"5
< i.49xio
< 5.56xlo"5
< 1.5x10-%
< 1. 07x10"'
1.8xlo7
2.4xio7
7.7x10"'
< 6.0x10"^
< 8.0x10
-4
< 2.34x10"*
-------
Table VI-3
Miscellaneous RWL Loads for Subcategory C
Product
Acetaldehyde
Acetic Acid
Ethylene Glycol
Phenol/acetone
Terephthalic Aci d
Dimethyl Terephthalate
Oxo-chemi cals
Acrylic Acid
Acrylates
Caprolactam
An i1i ne
Bi sphenol-A
Vinyl Acetate
Tetraethyl Lead
Methyl Methacrylate (wi th acid recovery)
Methyl Methacrylate (without acid recovery)
Flow
ga 1/1000 Ib
90
61
35
10.22
584
164
1,090
43.4
715
593
68.8
325
420
475
2,895
1,334
190
66.8
28
12,000
213
260
Phenol
mg/L
1.81
0.22
5.3
2.7
0.14
6,100
0.23
0.13
1.75
0.018
.-
0.093
0.36
0.17
0.229
9.9
12,600
17
0.301
0.06
2.38
lb/1000 Ib
1.36x10"'
1.1x10"*
1.6x10"'
2.3x10"*
6.8X10"1*
8.3
2.1x10"'
4.7x10"'
0.01
-
l.OxlO"5
-
3.2X10"1*
1.43x10"'
3 . 98x10"'
2.55x10"'
0.0156
7.0
4.1x10"'
0.0301
I.o6xl0"5
0.0052
NH-.-N
mg/L
0.7
0.7
0.7
1.12
0.7
1.47
1.4
1.4
2.1
3.58
0.7
4.2
4.2
0.7
t
0.7
906
3,607
1.8
0.7
0.7
2.1
-
lb/1000 Ib
5.2x10^
2.0x10
9.6xlO"5
0.0034
2.0x10"'
0.0127,,
5.0x10"*
0.013
0.018
4.0x10"*
9.47x10"'
0 . 0147
2.77x10"'
0.0167
10.081
5.7
1.02x10"'
1.7X10"1*
0.07
3.7x10"'
-
mg/L
1.7
1.4
1.4
2.2
3-5
2.2
4.2
2.8
2.8'
63
1.4
75
9.1
3-5
42
956
3730
15.5
2.1
2.1
2.8
-
TKN-N
lb/1000 Ib
1.3X10JJ
7-ixioT;
4.1x10
1.85x10"*
0.017
3.0x10"'
0.038
1.0x10"'
0.017
0.3117
S.OxlO"1*
0.1905
0.032
1.39xlO~2
1.015
10.635
5-9
8.59x10"'
5.X10-4
0.21
4.96x10"'
mg/L
2.7
< 0.04
< 0.04
_
0.056
< 0.04
0.80
< 0.04
< 0.04
-
< 0.04
-
0.05
< o.o4
<0.04
0.047
0.14
0.32
< o.o4
0.12
< o.o4
< 0.04
CN
lb/1000 Ib
2.0x10"'
2.0x10"'
1.0x10"'
-
2.7x10"*
4.0xlO"5
T.4xlO~'
< 1.4x10"?
< 2.3x10"*
-
< 2.3xlO"5
-
1.74x10
1.58X10"1*
< 9. 55x10
5.22x10
-4
2.3x10
1.8x10"*
<1.0xlO~5
0.012
7.09xlO~5
8.69x!0"5
Sulfate
mg/L
373
1.0
1.0
10.7
1,170
154
260
300
896
-
47
-
130
90
232
89.5
10,200
138
2500
440
4,400
-
lb/1000 Ib
0-23^
5.1x107
2.9x10
9.1x10
5.7
0.21
2.4
0.110
5.3
-
0.027
-
0.4535
0.3564
5.60
0.9953
16.1
0.077
0.6
44
7.80
-
mg/L
105
1
11
1,294
2
1,230
29.4
-
-
30
-
151
11.4
55
10.8
17.1
-
0.7
11.4
0.2
703
Oil
lb/1000 Ib
0.0794
5.6x10 ,
3-3x10"'
0.11
9.7x10"'
1.67
0.011
«
-
0.017
-
0.5268
0.0451
1.33
0.1203
0.027
-
-4
1.7x10
1.14
3.55x10"*
1.52
-------
Table VI -3
(continued)
Product
Acetaldehyde
Acetic Acid
Ethylene Glycol
Phenol/acetone
Terephthalic Acid
DO
OO Dimethyl Terephthalate
O
Oxo-chemi cats
Acrylic Acid
Acrylates
Caprolactam
An i 1 i ne
Bisphenol-A
Vinyl Acetate
Tetraethyl Lead
Methyl Methacrylate (with acid recovery)
Methyl Methacrylate (without acid recovery)
mg/L
2.58
17.4
7.6
0.55
0.194
0.16
20
2.61
4.5
-
0.854
-
0.65
0.32
0.064
0.11
4.3
-
2.43
1.024
-
-
T-P
lb/1000 Ib
1.94x10"'
8.9x10°
2.2x10"'
4.7x!0"5
9.5x10"^
-4
2.2x10
°-l8_4
9.4x10
0.027
-
4.8x10"^
-
2.27x10"'
1.27x10"'
1.45x10"'
1.26x10"'
0.8x10"'
-
5.8x10"^
0.1024
-
-
mg/L
0.36
0.05
0.1
0.06
0.22
0.22
0.90
1.57
0.19
-
1.11
-
-
-
-
-
0.35
0.56
0.12
0.98
-
-
Zn
lb/1000 Ib
2. 7x10 "^
3.0x10"'
3.0x10"'
5.0X10"6
1.07x10"'
3. 1x10 "^
8.1x10^
5.6x10
0.0013
-
6.3x10
-
_
_
_
-
5.6X10"1*
3.1X10"1*
-4
2.9x10
0.098
-
-
mg/L
16
0.42
1.7
0.11
0.3
0.70
0.40
0.36
0.23
24.6
0.25
29.7
0.54
0.08
0.08
0.94
0.05
0.31
0.07
1.30
52.2
288
Cu
lb/1000 Ib
0.012^
2.1x10 k
5.0x10
9.0x10
1.46x10"'
9.5x10"'
3.6xlOjJ
1 .3x10
0.0014
0.1213
1.4x10
0.081
1.88x10"'
3.17x10"^
1.9x10"'
1.04x10"'
7.3xlO"5
1 . 7x10
1.7xlO~5
0.13
0.0926
6.25x10"'
mg/L
2.3
0.5
0.74
0.36
1-5
0.7
12.7
5.4
6.7
-
1.77
-
3-5
0.5
0.73
2.22
0.28
10
0.50
1.0
1.14
500
Fe
lb/1000 Ib
1.73x10:'
S.6xlOT;
2.2x10
3.1X10"5
7.3x10"'
9.56x10"*
0.12
1.9x10"'
0.04
-
1.0x10"'
-
0.0122
1.98x10"'
0.0176
2.47xlO"2
4.4X10"4
5.56x10"'
-4
1.2x10
0.1
2.02x10"'
1.085
mg/L
2.7
<0.05
<0.05
<0.05
<0.05
< 0.05
0.6
4.58
< 0.05
-
3-51
-
0.4
<0.55
0.143
<0.05
2.7
< 0.05
0.07
< 0.05
-
-
Cr
lb/1000 Ib
1.99x10"'
< 3. 0x10"'
< 2. Oxlt)"'
< 5-Oxlo"6
< S.4X10"1*
<4.6xlO"5
5.4x10"'
1.65x10;?
< 3.0x10
-
2.0x10"'
-
1.396x10"'
< 2. 18x10"'
3.27x10"'
< 5.52X10"1*
4.2x10"'
< 2.8xlO"5
1.7xlO"5
< 0.005
-
-
mg/L
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
< 0.05
_
< 0.05
0.05
0.05
0.05
< 0.05
< 0.02
< 0.05
< 0.05
< 0.05
-
-
Cd
lb/1000 Ib
<3.7xlO"5
< 3. 0x10"'
< 3.0x10"'
< 5.0x10
< 2.4x10
< 9.1X10"5
< 4.5x10"^
< 1.8x10 7
< 3.0x10
-
<2.8x!0"5
-
-4
1.74x10
1.98X10"1*
1.19x10"'
5.52x10
< 3.1xlOA
< 2.8xlO"5
< 1.2xlO"5
< 0.005
_
-
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGIES
It is the aim of this section to describe and present available
data on the different pollution control and treatment
technologies which are applicable to the organic chemicals
industry. Based on that data avilable, conclusions have been
drawn relative to the reduction of various pollutants which is
commensurate with three distinct levels of technology. These
levels are defined as;
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE (BPCTCA)
BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE (BATEA)
BEST AVAILABLE DEMONSTRATED CONTROL
TECHNOLOGY (BADCT)
The conclusions relative to what combination of control and
treatment technologies are consistent with these definitions are
embodied in the reduction or removal of pollutants specified for
each level. In later sections of this report specific reduction
factors are applied to the process RWL developed for each
industrial category to obtain numerical values for effluent
limitations and new source performance standards. These
reductions are general and are considered to be attainable by all
of the rpocesses considered within the category.
The costs associated with these effluent limitations and new
source performance standards have been estimated based on model
systems which are considered capable of attaining the reduction
factors associated with each technology. It should be noted and
understood that these particular systems chosen for use in the
economic models are not the only systems which are capable of
attaining the specified pollutant reductions. There exist many
alternate systems which either taken singly or in combination are
capable of attaining the effluent limitations and standards
recommended in this report. These alternate choices include:
1. different types of end-of-pipe waste water
treatment,
2. different in-process modifications and pollution
control equipment,
3. different integrated combinations of end-of-pipe
and in-process technologies.
It is the intent of this study to allow the individual
manufacturers within the organic chemicals industry to make the
ultimate choice of what specific combination of pollution control
281
-------
measures is best suited to his situations in complying with the
limitations and standards presented in this report.
In-Process Systems
It is not possible to recommend a general list of process
modifications or control measures which are applicable to all of
these processes within the organic chemicals industry or even to
the processes within one industrial subcategory. The following
discussions deal with individual techniques which may be
applicable to groups of processes or to single processes. The
techniques described are based on both the practices observed
during the sampling visits as well as those which have been
described in the literature. In most cases, they can both be
implemented with existing processes or designed into new ones.
The general effect of these techniques is to reduce both the
pollutant RWL and the volume of contact process water discharged
for end-of-pipe treatment. This corresponds to moving the data
shown in Figures V-1 through V-11 toward the lower left side of
the RWL envelopes.
The control technology described in the following paragraphs
starting on page VII- 1 to page VII- 4 comes from:
Thompson, S.J., "Techniques for Reducing Refinery Wastewater,
"Oil_and Gas^, Journal , Vol. 68, No. 10, 1970, pp. 93-98.
Substitution of Surface Heat Exchangers for Contact
Water Used in Barometric Condensers
Figure VII-1 illustrates the classic barometric condenser. In
the typica^. example shown, the volume of water being contaminated
can be decreased from 260,000 Ib/hr to 10,000 Ib/hr for a
condensing duty of 10,000,000 BTU/hr. This can be accomplished
by substituting an air exchanger for water sprays. This type of
process modification can be sized to cover almost an infinate
number of specific process cooling duties.
It should be noted that water cooled surface condensers can also
be used in this application. However, these require the use of
non- contact cooling water.
Regeneration of Contact __ Process Steam from Contaminated
Condensate
Figures VII-2 illustrates the trade-off between contaminated
contact process steam condensate and non-contact steam blowdown.
The contact process waste water is reduced to a small amount of
condensate. This scheme can be used to regenerate stripping
steam in distillation towers or dilution steam in pyrolysis
furnaces. Heat exchange is through a surface shell- and-tube heat
exchanger, which can be sized for a wide variety of heat transfer
duties. A system similar to this was described in detail for
ethylene manufacture in Section IV.
282
-------
FIGURE Vll-l
BAROMETRIC CONDENSER
CUSTOMARY
WATER VAPOR IN
COOLING WATER
FOR 10-MILLION-BTU/HR DUTY,
COOLING WATER AT 85°,
OUTLET TEMPERATURE AT 125°
PROCESS WATER 10,000 LB/HR
COOLING WATER 250,000 LB/HR
TOTAL 260,000 LB/HR
CONTAMINATED WATER
SUBSTITUTION OF AN AIR FAN
WATER VAPOR IN
PROCESS WATER
COOLING WATER
TOTAL
10,000 LB/HR
0
10,000 LB/HR CONTAMINATED WATER
L^J
-------
FIGURE VII-2
PROCESS STEAM CONDENSATE
CONTAMINATED PROCESS
REGENERATED
PROCESS STEAM
STEAM CONDENSATE
NON-CONTACT STEAM
SLOWDOWN
(CONTACT PROCESS
KASTEIKATER)
NON-CONTACT
CONDENSATE
284
-------
Substitution of Vacuum Pumps for Steam Jet. Electors
The use of vacuum pumps in place of steam jet ejectors is shown
in Figure VII-3. This practice can be used to eliminate process
RWL from the condensed steam used to draw a vacuum on the
process. A specific vacuum pump system has been sized and priced
for application in the process for manufacturing styrene by the
dehydrogenation of ethyl benzene (Section IV). This same type of
system is applicable to many other processes where operation
under vacuum is necessary.
It should be noted that in many cases the steam jet ejector
system may be coupled with a barometric condenser instead of the
surface cooler shown in Figure VII-3. In this case, the volume
reduction of contact process waste water will be quite
substantial. It may also be possible to use the hydrocarbon
vapors from the vacuum pump in the plant fuel-gas system (because
of the reduced moisture content) rather than venting theirt to a
flare.
The liquid compressant in a vacuum pump can protect it from
corrosion. The manufacturers have accumulated operating data on
performance of many liquids with different gas mixtures. It has
been concluded that ordinary cast iron will often stand up well
in resisting corrosive gases. More expensive materials for pump
construction, such as monel or hastelloy C are available for
particularly corrosive gases such as halogens.
Recycle of ^Scrubber Water
Figure VII-4 illustrates a method of concentrating contaminants
in scrubber bottoms nearly to their saturation point. This is
accomplished by recirculation of the scrubbing or wash water.
Theoretically< the tower would require more trays or contacts, as
dictated by the specific vapor-liquid equilibrium of the system.
However, in many cases, existing towers can be modified to work
in the manner illustrated.
Recovery of_lnsoluble Hydrocarbons
Two methods for improving the separation of insoluble
hydrocarbons from water are shown in Figures VII-5 and 6. This
type of separation is usually done by gravity in tanks which are
similar to the oil/water separators used in refineries. The
first technique involves the mixing of lighter oils to make the
total hydrocarbon stream lighter and easier to separate. The
second is the use of fuel gas to create an upward current in the
separator. These techniques are widely used in ethylene plants
to separate insoluble hydrocarbon by-products from the cracked
gas quench water. Other systems such as filters and coalescers
are also used for this type of separation.
The separation of oil by gravity is a common unit process in the
cleanup of any oily waste water. The primary method of
separation is to provide holding time so that the flow can be
285
-------
FIGURE VII-3
NON-CONDENSIBLE REMOVAL
CUSTOMARY - VACUUM JETS
COOLING
WATER
FLARE
POLLUTED WATER
ALTERNATE - VACUUM PUMP
TO FUEL-GAS HEADER OR FLARE
286
-------
FIGURE VII-4
WATER SCRUBBING
CUSTOMARY
ALTERNATE
CLEAN
MATERIAL
OUT
CONTAMINATED .
MATERIAL IN
FRESH WATER
CONTAMINATED
MATERIAL IN
i CONTAMINATED
WATER
CLEAN
MATERIAL
OUT
FRESH WATER
A LESS WATER, MORE
* ' CONTAMINANTS
PER POUND
287
-------
FIGURE VII-5
OIL AND WATER SEPARATION
LIGHT-OIL ADDITION
LIGHT OIL
OIL AND WATER
MIXTURE
RELATIVELY LIGHT OIL
OIL TO
PROCESSING
WASTE WATER
288
-------
FIGURE VII-6
OIL AND WATER SEPARATION
FUEL-GAS ADDITION
OIL AND
WATER IN
PROCESS
GAS IN
FUEL GAS OUT
OIL OUT
WATER OUT
289
-------
maintained in a quiescent condition. Typical efficiencies of oil
separation units are presented in Table VII-1.
Spent Caustic and Oily Sludge Incinerator
The final disposal of spent caustic and oily sludges has been
successfully accomplished by using a fluid-bed incinerator. As
the sludge is burned, the solids remain in the bed, while the
gaseous products of combustion and water vapor discharge through
the gas-cleaning system. When the operation on oily sludge has
been stabilized, spent caustic is introduced. Water in the
caustic solution is vaporized and the combustible material is
oxidized; the solids accumulate in the fluid bed. The bed level
is maintained by withdrawing ash as it accumulates from the
deposition of solids. Solids removed from the process consist of
iron oxide, sodium sulfate, sodium carbonate, and other inert
solids, and have been used for landfill. Stack gases from the
incinerator consists of water vapor, nitrogen, oxygen, carbon
dioxide, and a few tenths of a part per million of sulfur
dioxide.
Various phenol recovery systems using solvent extraction, carbon
adsorption, and caustic precipitation are also described in
Section IV. These recovery processes are all associated with
phenol manufacturing processes.
Ph e no1jRemova j.
Solvent Extraction
Solvent extraction has been used very effectively by the
petroleum industry to remove phenols from various streams. Some
of these solvents which have been used to extract phenols are
aliphatic esters, benzene, light cycle oil, light oil, and tri-
cresyl phosphates. Among those solvents, tri-cresyl phosphates
are excellent solvents due to their low solubility in water and
their high distribution coefficients for phenol but they are
expensive and deteriorate at high distillation temperatures.
However, it might be used when high phenol recoveries are desired
for economic reasons. Most of the other solvents are consierably
cheaper to use in waste treatment operations. Several types of
extraction equipment such as centrifugal extractors,
electrostatic extractors, etc., are available and the type of
extraction equipment required for the use of a particular solvent
is an important economic consideration. Reported efficiencies of
some solvent extraction for phenol removal are given in the
following tabulation.
290
-------
TABLE VIl-l
Typical Efficiencies of Oil Separation Units'-
Oi 1
1 nf 1 uent
(mq/L)
7000-8000
3200
400-200
220
108
108
90-98
50-100
42
Content
Effluent
(mq/L)
125
10-50
10-40
49
20
50
40-44
20-40
20
Oi 1 Removed
%
98-99+
98-99+
90-95
78
81.5
54
55
60
52
Type of
Separator
Ci rcular
Impound!ng
Parallel Plate
API
Ci rcular
Ci rcular
API
API
API
"'"Petrochemical Effluents Treatment Practices," Federal Water Pollution
Control Administration, U.S. Department of the Interior, Program No. 12020--2/70.
291
-------
Typical Efficiencies for Phenol Removal by Solvent
Extraction*
__ Phenol __ Phenol
Solvent ______ Influent^ mq/1 Effluentx_mg/l
Aromatics, 7555 200 0.2 99.9
Paraffins, 25 %
Aliphatic Esters 4,000 60 98.5
Benzene 750 3U 95.5
Light Cycle Oil 7,300 30 90
Light Oil 3,000 35 99
Tri-cresyl Phosphates 3,000 300-150 90-95
* "Petrochemical Effluents Treatment Practices", Federal Water
Pollution Control Administration, U. S. Department of the
Interior, Program No. 12020, February 1970.
Steam Stripping
Steam stripping method has also been successfully used in
removing phenol from waste streams. The method involves the
continuous downward flow of the waste water through a packed or
trayed tower while the stripping steam flows upward removing the
desired constituent. The removed phenols are recycled back to
the appropriate process. This stripping method can achieve at
least a phenol reduction of 90 percent.
Chlorine Oxidation
Chlorine has been applied in oxidizing phenol in waste waters.
The oxidation of phenol must be carried to completion to prevent
the release of chlorophenols. An excess of chlorine is usually
required because of the reaction with various other chemical
compounds such as ammonia, sulfides, and various organics which
can interfere with the chlorination process. Despite the
potential for formation of chlorophenolics, chlorine can be used
to completely (10 OX) oxidize phenolics under proper conditions.
Ammonia and Sulfide stripper
Removal of hydrogen sulfide and ammonia from sour water can also
be accomplished by stripping methods. Most of these stripping
methods also involve the continuous downward flow of the waste
water through a packed or trayed tower while the stripping gas or
steam flows upward removing the desired constituent. Steam is
considered to be the preferred heating and stripping agent, since
hydrogen sulfide, which is concentrated in the steam condensate,
may be further treated. Flue gases are frequently used because
carbon dioxide produces a slightly stronger acid than hydrogen
sulfide thus releasing hydrogen sulfide from the solution. The
typical removal efficiencies are:
removal 98-99+X
292
-------
NH3 removal 95-97%
In many cases steam stripping may also remove as much as 20-40
percent of any phenols present.
Cyanide Removal
Cyanide can be oxidized to carbon dioxide and nitrogen by
chlorination. The waste water must be kept at a pH value greater
than 8.5 during treatment to prevent the release of toxic
cyanogen chloride. The reaction time usually is one to two hours
and the process is subject to the interference of various
compounds such as ammonia, sulfides, and various organic
substances.
O zone^Tr ea tirvent
Ozone has been proposed as an oxidizing agent for phenols,
cyanides, and unsaturated organic substances, since it is a
considerably stronger oxidizing agent than chlorine. The chief
disadvantages are the high initial cost of the equipment for
energy needs and cooling water requirements for ozone generation.
Ozone has several advantages, the most important being its
ability to rapidly react with phenol and cyanide. The optimum pH
for phenol destruction is 11 to 12. Thiocyanates, sulfates,
sulfides, and unsaturated organic compounds will also exert an
ozone demand which must be satisfied. This demand serves as the
basis of design for an ozonation unit treating a waste water
containing these compounds. Sulfides also can be removed from a
waste water which is to be ozonated by air stripping them at low
pH values, thus economically reducing the ozone demand. The pH
of the waste water can then be raised to the appropriate level
required for optimum ozonation.
Recent investigations have indicated the applicability of
ozonating wastes from the manufacture of chlorinated
hydrocarbons. The optimum pH for ozonation of this waste water
was found to be 12.6, and as much as 90 percent of the waste COD
was removed. This waste contains large quantities of unsaturated
hydrocarbons, which are readily amenable to ozonation. Ozonation
of a waste water can be either a batch or continuous operation,
depending on the characteristics of the waste and the waste flow
rate.
Incineration of Chlorinated^Hydrocarbons
There are a limited number of devices currently available for
burning waste chlorinated hydrocarbons with the recovery of by-
product HCJ,. In the past, the traditional disposal routes for
these waste materials have been ocean discharge, open-pit
burning, drum burial, and deep-well injection. Recently, more
stringent regulations have disallowed many of these methods.
Subsequently, there has been an increase in activity by industry
aimed at the development of systems for these hard-to-treat
293
-------
wastes. The weight of these materials is estimated at 350,000
tons/year of chlorinated hydrocarbon residues generated during
production of almost 10 million tons/year of chlorinated
hydrocarbons by chemical companies. It should be noted that
there are still serious drawbacks associated with most
incineration systems. These relate to both the emissions from
the systems as well as corrosion and other operating
difficulties. The following paragraphs describe the systems
currently utilized. It is not clear whether or not systems such
as these truly represent a viable alternative for the disposal of
hard-to-treat wastes. However, incineration is an alternative
which will receive additional consideration by manufacturers
whose processes generate concentrated reduced volume waste
streams.
More chemical companies now incinerate wastes that cannot be
treated. For example, one chemical company uses a high-
temperature incinerator to dispose of polych^orinated biphenyls.
Another chemical company has developed an efficient tar-burning
unit. A system based on this technology was recently completed.
Some plants have also added scrubbers to clean emissions from
incinerators. But for highly chlorinated hydrocarbon wastes--
i.e., those containing more than 50% chlorine--the emission of
gaseous hydrogen chloride is more than ordinary incinerator-
scrubber units can cope with.
For example, a neoprene plant at one time operated a horizontal
incinerator and vertical scrubber with a packed column in the
stack. Maintenance costs were excessive (about $40,000/year) and
hydrogen chloride emissions were too high.
This plant has since turned to the only system for chlorinated
hydrocarbon disposal and by-product recovery now operated in this
country.
Four units are now operating at different chemical plants. In
addition, another unit is scheduled to go on stream shortly.
There is only one company which is not recovering by-product
hydrogen chloride. The company decided against recovery because
high-pressure operating conditions at the plant would have
required the addition of equipment to compress the gas stream
before stripping hydrochloric acid.
The system incincerates chlorinated liquid waste, cools the
combustion gases, strips the aqueous product and turns out
anhydrous HC1.
Hydrogen chloride gas is soluble in water. But, absorption is
complicated by the heat generated in large quantities during
combustion. For example, 36.4 million BTUs/hour must be removed
from a 4,000 Ibs/hr unit.
In the system, the sticky chlorinated hydrocarbon residue is
atomized and incinerated in a combustion chamber that has a
294
-------
vortex-type burner supplied by Thermal Research. The incinerated
material is cooled from 2,500°F to 800°F in a graphite cooling
chamber, where it is sprayed with 27% HC1.
The cooled gas passes through three falling-film acid absorbers
made of impervious graphite. Stripped liquid is recycled through
the absorbers in reverse order, removing heat of absorption and
HC1 from the gas stream.
Gas from the last absorber enters a final scrubber to reduce HC1
emissions about 5 ppm. This scrubber is 5 ft. in diameter,
contains 3 ft. of 1-inch-diameter plastic packing and includes a
spray header and a demister made of polypropylene.
At some plants, the gas is released to the atmosphere through a
stack designed for silencing the exhaust. It is a packed
centrifugal unit with a diameter enlargement before the stack
outlet to reduce gas velocity and permit entrained liquid
particles larger than 100 microns to settle out.
The major problem with units has been the junction between the
combustion and cooling chambers. The carbon blocks of the
cooling chamber oxidize at 750°F and all parts of the chamber
must be covered with liquid. If the spray is not properly
adjusted, liquid HC1 backs up into the combustion chamber and
attacks the mortar joints and steel outer shell. A ceramic
sleeve is now used to protect the furnace refractory at the joint
from the HC1 spray.
•
One company has also switched from field-erected to preassembled
cooling chambers. Field-erected units were made of dense (100
Ibs./cu.ft.) carbon blocks, keyed together by graphite rods,
cemented with a special carbonaceous cement and reinforced by
rubber-covered steel bands. The preassembled chambers have
graphite wall units, eliminating the possibility of leaky joints.
From a pollution-control standpoint, the most significant change
that can be made in process chemistry is from a "wet" process to
a "dry" process, that is the substitution of some other solvent
for water in which to carry out the reaction or to purify the
product.
If any organic solvent can be used, the process can probably be
worked out to produce an organic concentrate that will contain
all the undesirable impurities and by-products. Their disposal
in an organic concentrate is much simpler and cheaper than coping
with them in an aqueous medium. Incinceration costs for
descruction of organic concentrates by contractors usually run
between $0.01/lb. and $0.03/lb., depending on the halogen content
and the presence of ether inorganic compounds.
If water must be used in the process, its use should be
restricted, and every opportunity for the replacement of fresh
water with recycle water should be explored and implemented.
(This is especially important in the inorganic chemical
295
-------
processes.) Use of water can be restricted by countercurrent
washing techniques. Discarding of waste water used for pruifying
a reaction product when fresh water is used for the reaction
medium is also uncalled for. Similarly, another useful water-
conservation practice is collection of vacuum-jet condensate,
rain water, and floor water for reuse.
Another process change that can yield significant pollution-
control benefits is the elimination of troublesome by-products by
a change in the reactants, or a change in the catalyst. An
example of the former is the emergency of oxychlorination
processes (that generate by-product hydrochloric acid).
From these discussion it is apparent that significant reductions
in the quantity of pollutants generated by a process are
possible. Quantitative estimates for specific processes indicate
that in some cases waste water flows can be reduced to
approximately 10 gallons/1,000 Ib of product, and corresponding
COD loadings of 0.1 Ib of COD/1,000 Ibs of product. In some
specific cases the discharge of pollutants can be reduced to near
zero through the use of by-product recovery processes such as
adsorption. Such systems generally take advantage of the
specific characteristics of the chemicals in questions. It is
not possible to specify a uniform restriction based on such
systems that could be applied throughout the indistry, or even
one category.
End-pf-Pipe Treatment System
General Considerations
Raw Waste Load data from the Phase I field survey was handled as
a separate report. However, because of the scarcity of treatment
plant performance data, it was decided to combine the Phase I and
Phase II data for this study. A summary of the types of
treatment technology which were observed during both phases are
listed in Table VII-2. During the Phase II study, 70 individual
plants were surveyed however, 6 of the 70 plants were previously
surveyed during the Phase I study. Table VTI-2 has been prepared
taking this duplication into consideration.
Biological Treatment
During the plant survey program, historic wastewater treatment
plant performance data were obtained when possible. The data
were statistically analyzed, and, when possible, the individual
plant performance was evaluated with respect to the original
design basis. Subsequent to this evaluation, a groups of plants
were selected as being exemplary in performance. These
particular exemplary plants are indicated in Table VII"3 which is
a summary of all of the historic performance data made available
by industry for the purposes of the study. The amount of
analytical data used in the statistical analyses are indicated in
the "data base column" of Table VII-3. The following is a
summary of the average reductions capable of exemplary treatment
plants:
296
-------
Table Vll-2
Organic Chemicals Study
Treatment Technology Survey
Type of Treatment or Disposal Facility
Activated Sludge
Activated Sludge-aerated lagoon
Activated Sludge-polishing pond
Activated Sludge-solar evaporation pond
Trickling Filter-activated sludge
Aerated lagoon-settling pond
Aerated lagoon-no solids separation
Facultative Anaerobic lagoon
Stripping Tower
No current treatment -
system in planning stage
To Municipal Treatment Plant
Deep-wel1 disposa1
Physical Treatment, e.g. API Separator
Activated Carbon
Inci nerati on
TOTAL
Number of Plants Observed
Phase 1
7
2
0
0
1
3
2
k
1
3
5
2
k
0
_0
3k
Phase I 1
9
0
1
1
0
1
1
k
1
7
23
6
3
6
_J_
6k
297
-------
Table VI1-3
Historic Treatment Plant Performance
50% Probability of Occurrence
COD
BOD
TOC
SS
Data Base
Plant
No.
1'
21,2
3'
4!
51,2
6
7
81
91
10'
,,1,2
12
13
14
15
161
1?1
18
191
201
Exemplary
Exemplary
Treatment
System
AL
AS-AL
AS
AS
TF-AS
AL
AL
AL
AS
AS
AS-AL
AS
AS
AS
AL
AS
AS
AS
AS
AS
Plant Average
Single Stage
Category /
0
C
0
B
B
B-C
C
B
C
B
C
A-B
B-C
B
D
D
0
0
C
Plants - Average
o Remova 1
75
96.4
63
64.2
73.5
-
-
-
-
74.5
-
85
-
--
--
-
67
25.4
--
--
74
69
Effluent
320
4?0
200
120
83
--
165
75
-
80
-
97
610
-
226
-
1,760
1,520
-
296
378
% Remova 1
97
-
93.5
-
-
-
~
-
83
90.1
99.7
-
-
73
-
82.5
-
63.6
97.6
98.8
93
92
Effluent „, „ , Effluent
,. % Remova 1 .,
10
-
16
15
-
291
9.9
23.5
152 60 170
20
20 97 100
59
294 — 295
410 42 780
63
362
-
303
157 — — .
46.9
82.2 79 135
60
0. „ , Effluent
% Remova 1 , ,
__
163
55
--
-
665
81
24.3
130
-
-370 145
-
189
280
-
289
..
480
-
-
134
-
Durat i on
(mojrt: h sj
6(Sept-Feb)
12
12
14
14
12
12
12
7(Aug-Feb)
12
12
12
14
14
6(july-Dec)
S(Aug-Mar)
6(june-0ct)
12
5(June-Sept)
S(June-Sept)
Performance
Pe r i od
daily average
da i ly average
monthly average
monthly average
month ly average
weekly average
monthly average
month 1 y average
da i 1 y average
weekly average
dai ly average
month 1 y average
monthly average
monthly average
weekly average
month ly average
da i ly average
weekly average
month ly average
weekly average
Plants considered to be exemplary in performance.
Multipie-stage biological treatment.
Plant 16 is not included in average.
-------
COD BOD TOC Effluent
^Removal Removal Removal TSS
percent percent percent mg/1
Exemplary Single - and
Multiple-Stage Plants 74 93 79 134
Exemplary Single-stage
Plants 69 92 60 65
The major differences observed in performance from the previous
analyses are in the TOC removals. This is because only two
historic TOC data points are available.
During the survey program, 24-hour composite samples were
obtained in order to verify the plant's historic performance
data, as well as to provide a more complete waste water
analytical profile. These results are presented in Table VII-4.
The following is a summary of the average reductions capable of
being attained by exemplary treatment as verified by composite
sampling:
COD BOD TOC
_Removal Removal Removal
percent percent percent
Exemplary Treatment
Plants 72 87 58
Considering the variability associated with daily composite
sample, testing and treatment plant performance, these
efficiencies agree with the long term historical data.
The TOC removal of 58 percent would seem to substantiate the
lower value of 60 percent as previously indicated for the
historic values appearing in Table VII-3. As indicated by the
TSS removal data, 9 of the 17 plants surveyed had negative TSS
removal and over 75 percent of the plants had inadequate solids
handling facilities.
The impact of TDS and oil on the TSS levels for the plants
surveyed is indicated in Table VII-4. There is a trend
indicating that high TDS and oils in the plant effluent
contribute to high TSS levels, e.g. note the direct effect of TDS
on the TSS is not clear from the sampling data, e.g. Plants 21
and 22 have high TDS and relatively low TSS, while Plant 19 has a
high TDS as well as TSS in it effluent.
During the course of the plant surveys, three plants were
observed to have multiple-stage biological treatment. Plant 5
(see Table VII-3) required two-stage treatment for phenol
removal, while Plants 2 and 11 required it because of relatively
high raw waste loads.
Filtration
299
-------
Table Vll-4
Treatment Plant Survey Data
Plant No.
22
11
13
162
172
18
192
202
21
22
23
AS-AL
AS
AS
TF-AS
AL
AL
AS
AS-AL
AS
AS
AS
AS
AS
AS
AL
AS
AS
B-C
B
C
C
B-C
0
D
D
D
C
C
COD
% Removal
64
71
57
59
66
69
75
94
65
54.8
60.0
77.3
22.1
59.5
96.2
62
16.1
95.4
72
Effluent
mg/L
2,300
284
214
133
980
92
595
337
940
1 ,650
1 ,400
1 ,000
2,680
5,100
317
600
1,370
147
Total
% Removal
90
73
82
92
73
84
92
99
90
82.1
81.4
90.0
16.7
69.8
99.5
78
47.5
92.6
87
BOD
Effluent
mg/L
427
74
13
12
235
6
75
16
177
300
240
310
650
1 ,800
19
27
210
41
TOC
% Removal
mg/L
32
71
35
43
11
26
69
27
64
80.8
63.4
76.8
-
55.8
96.6
66
8.3
95.4
58
Effluent
mg/L
2,710
132
80
61
573
52
242
343
470
280
410
360
1 ,025
1 ,700
114
47
550
35
TSS
% Removal
Negative
Negative
40
97
Negative
99
Negat i ve
Negat i ve
120
43.6
Negative
42.9
Negative
Negat i ve
89
53.4
Negative
Effluent
mg/L
4,700
62
14
44
362
3
50
145
338
552
1 ,300
732
1 ,170
2,500
100
30
82
37
TDS
Effluent
mg/L
2,300
3,100
2,900
1 ,430
3,000
690
3,810
2,690
1 ,520
10,990
3,750
4,060
2,050
8,360
1 ,950
9,800
15,400
580
Oil £- Grease
Effluent
mg/L
-
,3
43
23
113
-
123
,3
63
2264
22*
106^
-
194
-
-------
Supplement organics and solids removal is being practiced within
the industry in one particular case using a polishing pond. One
major problem during summer solids periods is algal blooms which,
if unchecked, can drastically increase the TSS and COD of the
polishing pond effluent. In addition, the acreage requirements
of this system limits its potential uniform application.
In contrast, filtration has many of the advantages of polishing
ponds and few of the disadvantages. In order to quantify the
effectiveness of effluent filtration, samples of biological
treatment plant effluents were collected and filtered using
filter paper. The results are presented in Table VII-5. Average
percent COD, BOD, and TOC removals associated with filtration are
20, 17, and 20 respectively,
Carbon Adsorption
Granular activated carbon technology is continuously being
developed and is beginning com compete actively with biological
treatment as a viable treatment alternative or as a biological
treatment effluent polishing process for some industrial wastes.
There exists a limited amenability of many low molecular weight,
oxygenated chemicals to adsorption on activated carbon. In
addition, experience has indicated that TSS in amounts exceeding
50 mg/1 and oils above concentrations of 10 mg/1 should not be
applied directly to carbon beds. These materials tend to clog
and coat the carbon particles, thereby reducing the adsorption
effectiveness.
During the plant survey program, 6 activated carbon plants
treating raw wastewaters were surveyed, and the results are
presented in Table VII-6. The most interesting fact is that
domestic wastewater treatment experience indicates that efficient
treatment is provided with contact times between 10 and 50
minutes, while the design contact times in Table VII-6 vary
between 22 and 660 minutes (calculated on an empty column basis.
These higher contact times are required because of the much
higher raw waste laods generated by industry.
The major porblems encountered in trying to compare design
criteria and present performance of carbon plants are as follows:
1. In most cases, design loadings, both organic and
hydraulic, have not been attained. This means the
new plants are sometimes grossly under-loaded.
2. Thermal carbon regeneration is presently an art
which is acquired only with actual operating
experience. For this reason, start-up problems
are often extended, and it is not unusual for the
pollutant concentrations of the activated carbon
effluent to be higher than the design value. This
situation continues until the carbon is regenerated
thoroughly.
301
-------
Table VI1-5
Removal by Filtration
(Performed on Biological Treatment Plant Effluent)
Plant
% COD
3
15
15
14
9
9
13
4
24
12
21
16
25
20
35
26
27
18
17
19
Average ^
9
87
85
24
11
10
32
—
8
21
3
84.3
39.3
8.5
51.4
26.2
—
86.8
88.4
33.3
20
°/0 BOD
4
56
28
36
57.8
17.2
71.4
12.5
72.1
55.6
17
% TOC
3
78
82
14
5
17
20
7
8
75.9
39-4
33.0
27.7
41.2
25.0
90.6
91.6
66.0
20
Average does not include plants 15, 16, 17, 18, and 26, since these plants
have excessively high effluent TSS and would bias the results.
302
-------
Table VII-6
Activated Carbon Plants Treating Raw Wastewaters
Plant
28
29
30
31
32
33
Removal Ef f iciencies-%
Pretreatment Design Present
Solids Removal and Polyol-11
Equal i zat i on 9-hr
detention time
Equalization 150- TOC -94 TOC -89
day detention time
Equalization, Neu- Phenol-89 Phenol-94
trail zat ion and
solids removal
Equalization and TOC-91
Neutra 1 i zat ion
Equal ization and Phenol-99.9 Phenol-95
Neutra 1 i zat i on
Equalization, Neu- Color-90
t ral l zat ion and
sol i ds remova 1
Hydraul ic Loadi ng
Flows-qpd gpm/sq.ft.
Desiqn Present Design Present
100,000 55,000 5.6 3.0
20,000 7,000 0.49 0.17
750,000 500,000 4.6 3.1
30,000 20,000
72,000 22,000 2.0 0.6
800,000 7.7
Contact Time-minutes
Carbon Exhaustion Rate
22
540
69
660
215
27
40
1,550
104
912
75
Desi qn
0.4 Ib. polypi
Ib. carbon
0.07 Ib. TOC
Ib. carbon
.028 Ib. pheno
Ib. carbon
Isotherm
5.4 Ibs. color
Ib. carbon
0.19 Ib. TOC
Ib. carbon
-------
3. Plants with insufficient spill protection
and/or inadequate housekeeping practices
may discharge specific low molecular weight
hydrocarbons which are not amenable to adsorption.
This situation results in an erratic plant
performance.
The carbon adsorption isotherm is widely used to screen the
applicability of different activated carbons and to calculate
theoretical exhaustion rates. The comparison of isotherm and
design exaustion rates for Plant 29 in Table VII-6 further
substantiates the fact that isotherm data is preliminary and
should not be used for design purposes. However, carbon isotherm
data does indicate relative amenability of the particular
wastewater to treatment and to fairly typical removal
efficiencies.
To investigate the possibility of using activated carbon
technology on the effluents from biological treatment plants
treating organic chemical wastewaters, a series of carbon
isotherms were run at standards conditions using a contact time
of 30 minutes. The results of the isotherms are presented in
Tables VII-7 through VII-9. Average performance values are
presented as follows:
Soluble
Pollutant
Parameter Carbon B^Exhauston Rate Removal
Lbs removal/lb carbon percent
COD 0.41 69
BOD 0.03 20
TOG 0.06 87
Inspection of the specific data in Tables VII-7 through VII-8
indicates that carbon adsorption has varying degrees of
amenability with regard to cost effective wastewater treatment.
However, the data does indicate that specific wastewaters are
readily treatable using activated carbon.
BPCTCA_Treatment Systems
The major purpose for the review of the historic treatment plant
data was to be able to quantify BPCTCA reduction factors, which
would then be applied to BPCTCA raw waste load figures for each
subcategory in order to generate recommended effluent limitations
guidelines. Based on the previous discussions of biological
treatment, the following pollutant reduction factors are
considered achievable with BPCTCA treatment technology:
304
-------
Table Vll-7
Sum-nary COD Carbon Isotherm Data
(Performed on Biological Treatment Plant Effluent)
Carbon Exhaustion Rate
Plant No.
14
15
15
3
9
9
13
13
4
2k
12
21
16
25
20
35
26
18
23
17
Average^
Ibs COD Removed
Ib Carbon
0.035
0.8
0.2
1.35
0.30
0.36
0.42
0.36
0.51
0.3^
4.5
0.11
.12
4.0
.45
.069
0.094
.41
Ibs Carbon
1 .000 qal 'ons
232
8.9
28.6
1.87
13.9
13.3
10.6
12.6
2.2
32.2
0.27
21.4
29-5
.25
2.0
3.9
44.3
15.7
Max. Soluble
COD Removal (%)
22
87
87
87
74
84
79
75
70
57
69
87
3
50.2
57 8
41.6
42 4
72.8
83 4
63.6
93.9
69.0
Category
B
D
C
B-C
B
B
B
C
D
C
B-C
A
D
B
g
D
The average does not include Plants No. 12, 14, 20 and 21.
305
-------
Table VI]-8
Summary BOD Carbon Isotherm Data
(Performed on Biological Treatment Plant Effluent)
CO
o
Plant
16
25
20
35
26
18
23
27
17
19
Averages 1
I nf luent
(soluble)
mg/L
165
12
2k
<1
6.3
78
2
7
166
Effluent
(soluble)
mg/L
82
1
9
5.2
0
<1
1
20
BOD Carbon Exhaustion
Removal Ibs BOD Removal Ibs Carbon
% Ib Carbon 1 ,000 gal
50.3
91.6 .021 k.S
62.6
17.5
100
>50
85.7
88.1 .039 35.5
89 .03 20.1
Average includes only Plant No. 17 and 25
-------
Table Vll-9
Summary TOC Carbon Isotherm Data
(Performed on Biological Treatment Plant Effluent)
CO
o
lant
16
25
20
35
26
18
23
27
17
19
Influent TOP.
(soluble)
mg/L
87
43
28
34
20
104
6
148
Effluent TOC
(sol ub le)
mg/L
58
5
12
4
2
19
3
20
TOC
Remova 1
%
33.4
88.4
37.2
88.3
90.0
81.6
50.0
86.6
Carbon Exhaustion
Ibs. TOC Removed Ibs. carbon
Ib. carbon 1 ,000 gal .
.01 35.9
— —
.13 2.25
1.35 .12
.0036 241
— —
.0485 25.4
Average
87
.063
21.77
Average includes Plant Nos. 17, 25i and 35.
-------
Percent Reduction Factors Monthly Min. Average
Range Average Effluent_Concen., mg/1
BODi 83-99 93 20
COD 63-96 74
TSS 65 mg/12 30
1. Controlling Parameters
2. Monthly Average
The BPCTCA effluent discharge recommendations will be made only
for BOD. The major source of TSS in biological treatment plant
effluents are biological solids which, in many cases, are
intentionally not wasted for further sludge dewatering but rather
are permitted to pass out in the plant effluent. This situation
is further compounded in certain plants which have very high TDS,
oil, and grease concentrations which tend to hinder settling and
thereby contribute to the high effluent TSS.
The major justification for minimum effluent concentration is
that a number of the BPCTCA BODS RWL data are in the vicinity of
100 mg/1. If BPCTCA reduction factors are applied without due
consideration, the resulting effluent concentrations will be
below what is achievable with BPCTCA technology. The recommended
minimum effluent concentrations were selected based on EPA's
preliminary definition of BPCTCA municipal secondary treatment.
The minimum TSS concentration is specified for plants attaining
the minimum BODS concentration. This insures that adequate
solids handling facilities will be provided.
To evaluate the economic effects of the BPCTCA effluent
limitations on the organic chemicals industry, it was necessary
to formulate a BPCTCA treatment model. The model selected was
single stage activated sludge. (See Figure VII-7). The BPCTCA
design basis are described in Table 11-10.
BATEA Treatment Systems
Based on the previous performance data from multiple-stage
biological treatment plants, existing carbon treatment plants and
various carbon isotherms, it has been possilbe to formulate waste
reduction factors commensurate as BATEA treatment technology:
Percent Reduction Factors Minimum Monthly Average
Applied to BPCTCA
Parameter Effluent Limitations Effluent Concentration
BOD 90 10
COD 69 50
TSS 15 mg/1 10
The BATEA effluent discharge limitations will have two
controlling parameters, i.e., BOD and COD. The major emphasis,
however, should be on COD removalb since the major portion of the
308
-------
carbonaceous oxygen demanding materials should have been removed
with BPCTCA technology.
The BATEA treatment model used for economic evaluation of the
proposed limitations inclused the BPCTCA treatment model followed
by the dual media filtration and carbon adsorption. A typical
flow diagram is shown in Figure VII-8. The BATEA design basis
and the unit sizing criteria are discussed in Table VII-11. The
carbon regeneration facilities were sized using 0.41 lb COD
removed/lb carbon which is the average result as determined from
the carbon isotherm data.
BADCT Treatment Systems
Based on the previous filtration data, it has been possible to
formulate waste reduction factors commensurate as BADCT treatment
technology:
Percent Reduction Factors Minimum Monthly Average
Applied to BBPCTCA Average Effluent
Parameter Effluent Limitation Concentration
mg/liter
BOD 17 10
COD 20
TSS 10 mg/1 10
The BADCT treatment model used for economic evaluation of the
proposed limitations includes the BPCTCA treatment model followed
by dual media filtration.
309
-------
Figure Vll-7
BPCTCA Waste Treatment Model
LEGENO
I UIRI
I FLOI
I IHDIC«TO«
U LIOUIO LEVEL
pH pH
I RECORDER
S SMPLEU
T TOTUIIER
SLUDGE t±J «EROBIC SLUDGE SWP
TH!C«E«E» SLUBGE IHNSFER PUWS DIGESTION B»SI«
POL»ELECI«a»I£
SOLUTION TANKS
-txl-CHxl—•
U-
SLUDGE
CHE
STORAGE
TRUCK PICK UP TO
SUNITMV LANDFILL
-------
Figure Vll-8
BATEA Waste Treatment Model
r-txh-
BIOLDSICAL TREATMENT
SACK HASH
HOLDING TANK
PLANT EFFLUENT
FILTER INLET
IELL
— ^-fc-txi-L
L, (v
DUAL MEDIA
GRAVITI FILTERS
REGENERATED CARBON
STORAGE TANK
DRV ING TANK
AIR BLOIER
SCREI FEEDER
REGENERATION FURNACE
VIRGIN
CARBON
STORAGE
-------
Table VII-10
BPCTCA Model Treatment System Design Summary
Treatment System Hydraulic Loading
(capacities covered, in gpd)
7,200
43,200
72,000
216,000
360,000
720,000
1,440.000
2,160,000
Pump. Station
Capacity to handle 200% of the average hydraulic flow
Equalization
One day detention time is provided for Subcategories A,
B, and C, and three days for Subcategory D. Floating
mixers and provided to keep the content completely
mixed.
Neutralization
The two-stage neutralization basin is sized on the basis
of an average detention time of twenty minutes. The
lime-handling facilities are sized to add 2,000 Ib of
hydrated lime per mgd of wastewater, to adjust the pH.
Bulk-storage facilities (based on 15 days usage) or bag
storage is provided, depending on plant size. Lime
addition is controlled by two pH probes, on in each
basin. The lime slurry is added to the neutralization
basin from a lime slurry recirculation loop. The lime
handling gacilities are enclosed in a building.
Nutrient Addition
Facilities are provided for the addition of phosphoric
acid and aqua ammonia to the biological system in order
to maninain the ratio of BOD:N: at 100:5: 1/
Aeration Basin
Platform-mounted mechnaical aerators are provided in the
aeration basin. In addition, concrete walkways are
provided to all aerators for access and maintenance.
The following data were used in sizing the aerators:
Oxygen utilization
alpha factor
beta factor
1.5 Ib 02/lb BOD removed
0.9
0.9
312
-------
wastewater Temperature 20 C
Oxygen transfer 3.5 Ib O^/hr/shaft hp
at 20 C and zero DO in tap water
Motor Efficiency 35%
Minimum Basin DO 1 mg/1
Oxygen is monitored in the basins using D.O. probes.
Secondary Clarifiers
All secondary clarifiers are rectangular units with a
length-to-width ratio of 3 to U. The side water depth
is 10 ft. and the overfolw rate varies between 100 and
500 gpd/sq ft depending on plant size. Sludge recycle
pumps are sized to di liver 100X of the average flow.
Air Flotation
The air flotation units recommended for Subcategory C
plants are sized on a solids loading of 20 Ibs/sq/ft/day. In
addition, liquid polymer facilities are provided to add up to 50
mg/1 of polymer to enhance solids separation.
Sludge Holding Tan k- Thickener
For the smaller plants, a sludge- holding tank is
provided, with sufficient capacity to hold 5 days flow from the
aerobic digester. The thickener provided for the large plants
was designed on the basis of 6 Ib/sq/ft/day and a side water
depth of 10 ft.
Aerobic Digester
The aerobic digester is sized on the basis of a
hydraulic detention time of 20 days. The sizing of the
aerator-mixers was based on 1.25 hp/1,000 cu ft of
digester volume.
Vacuum Filtration
The vacuum filters were sized on a cake yield of 2
Ib/sq/ft/hr, and a maximum running time of 18 hr/day.
The polymer system was sized to deliver up to 10 Ib of
polymer/ton dry solids.
Disposal
Sludge is disposed of at a sanitary landfill assumed to
be 5 miles from the wastewater treatment facility.
The plant's forward flow units are designed for parallel
flow, i.e., either half of the plant can be operated
independently, thus providing reliablility as well as
flexibility in operation. The sludge facilities are
designed on the basis of series flow. All outside
tankage is reinforced concrete. The 'tops of all outside
tanks are assumed to be 12" above grade.
313
-------
Table VII-11
BATEA End Qf^Pipe Treatment System
Design Summary
Filtration
The filters are sized on the basis of an average hydraulic
loading of 3 gpm/sq ft Backwash facilities are sized to provide
rates up to 20 gpm/sq ft and for a total backwash cycle of up to
20 minutes in duration. The filter media are 24" of (No, 1 1/2)
and 12" of sand (0.4-0.5 mm sand).
SS-SDiliJE Carbon Columns
The carbon columns are sized on a hydraulic loading of 4 gpm/sq
ft and a column detention time of 40 minutes. A backwash rate of
20 gpm/sq ft was assumed for 40% bed expansion at 70°F.
Design Comments:
Subcategory A and B are fixed-bed downflow units, while the
Subcategories C and D systems are pulsed-bed upflow unit,
with the carbon being wasted over a prescribed time sequence,
e,g, wasted for 15 minutes every two hours.
Silter-Column Decant Sump
Tanks are provided to hold the backwash water and decant it back
to the treatment plant over a 24 "hour period. This will
eliminate hydraulic surging of the treatment units.
Regeneration Furnace
The following exhaustion rates were used for the sizing of the
regeneration facilities:
Influent COD Exhaustion Capacity
Subcategory mg/1 Ib COD/lb carbon
A 100 4.5
B 120 4.5
C and D 1200 0.35
These exhaustion capacities were selected, based on the carbon
isotherm data previously presented in Table VII- 8.
A multiple-hearth furnace is employed for regeneration of the
carbon only for Subcategory D. The quantities of carbon
exhausted based on the previous exhaustion capacities for
Subcategories A and B are not sufficiently large to warrant the
investment in a regeneration furnace.
Exhausted Carbon Storage
Tanks are provided to handle the regenerated and exhausted carbon
both before and after regeneration.
314
-------
Section VIII
COST, ENERGY, AND NONWATER QUALITY ASPECTS
This section provides quantitative information relative to the
suggested end-of-pipe treatment models.
The cost, energy, and nonwater quality aspects of in-plant
controls are intimately related to the specific processes for
which they are developed. Although there are general cost and
energy requirements for equipment items (e.g. surface air
coolers) , these correlations are usually expressed in terms of
specific design parameters, such as the required heat transfer
area. Such parameters are related to the production rate and
specific situations that exist at a particular production site.
Reference to the Tables in Section IV, which show plant sizes for
specific process modules, indicates that even in the manufacture
of a single product there is a wide variation between process
plant sizes. When these production ranges are superimposed on
the large number of processes within each subcategory, it is
apparent that many detailed designs would be required to develop
a meaningful understanding of the economic impact of process
modifications. Such a development is really not necessary, be-
cause the end-of'pipe models are capable of attaining the
recommended effluent limitations at even the highest RWL within
any subcategory. The decision to attain the limitations through
in-plant controls or by end-of-pipe treatment should be left up
to individual manufacturers. Therefore, a series of designs for
the end-of-pipe treatment models are provided. These can be
related directly to the range of influent hydraulic and organic
loadings within each subcategory.
The range of costs associated with these systems can then be
divided by the range of production rates for any single process
within any category. This will show the maximum range of impact
on the required realization of any single product (i.e. the range
of impact in terms of $/lb of product). Total industry cost for
BPCTCA is estimated at $1,030 billion ("Economic Impact of Water
Pollution Control an this Organic Chemicals Industry, "Arthur D.
Little, Inc., Cambridge, Mass., 1973). It is estimated that this
cost includes a substantial portion of capital investment as of
1973.
The major nonwater quality consideration which may be associated
with in-process control measures is the use of alternative means
of ultimate disposal. As the process RWL is reduced in volume,
alternate disposal techniques such as incineration, ocean
discharge, and deep-well injection may become feasible. Recent
regulations are tending to limit the applicability of ocean dis-
charge and deep-well injection because of the potential long-term
detrimental effects associated with these disposal procedures.
Incineration is a viable alternative for concentrated waste
streams, particularly those associated with Subcategory C.
315
-------
Associated air pollution and the need for auxiliary fuel,
depending on the heating value of the waste, are considerations
which must be evaluated on an individual basis for each use.
Other nonwater quality aspects, such as noise levels, will not be
perceptibly affected. Most chemical plants generate fairly high
noise levels (85-95 dB(A>) within the battery limits because of
equipment such as pumps, compressors, steam jets, flare stacks,
etc. Equipment associated with in-process or end-of-pipe control
systems would not add significantly to these levels. In some
cases, substituting vacuum pumps for steam jets would in fact
reduce plant noise levels.
As discussed previously, design for the model treatment systems
proposed in Section VII were costs estimated in order to evaluate
the economic impact of the proposed effluent limitations. The
design consideration (namely, the influent RWL) was selected so
that it represented the highest expected RWL within each
category. This resulted in the generation of cost data for each
level of technology
Activated sludge was proposed in Section VII as the BPCTA model
treatment system. The plant designs were varied to generate cost
effectiveness data within each subcategory. Dual-media
filtration and activated carbon adsorption were proposed in
Section VII as best available technology economically achievable
(BATEA) treatment for Categories A, B, and C. New source end-of-
process treatment involves the addition of dual media filtration
to biological waste treatment model processes.
Capital and annual cost data were prepared for each of the
proposed treatment systems previously discussed in Chapter VII.
The capital costs were generated on a unit process basis, e.g.
equalization, neutralization, etc. The following "percent add
on" figures were applied to the total unit process costs in order
to develop the total capital cost requirements:
Item Percent of Unit
Process Capital Cost
Electrical 12
Piping 15
Instrumentation 8
Site work 3
Engineering design and
Construction supervision fees 15
Construction contiguency 15
Land costs were computed independently and added directly to the
total capital costs.
Annual costs were computed using the following cost basis:
316
-------
Item
Amortization
Operations and
Maintenence
Power
Cost Allocation
20 years for capital recovery at 8 percent
(10.2% of capital costs)
Includes labor and supervision, chemicals, sludge
hauling and disposal, insurance and taxes (com-
puted at 2 percent of the capital cost), and
maintenance (computed at 4 percent of the capi-
tal cost).
Based on $0.02/kw hr for electrical power. Only
BATEA Subcategory D (activated carbon regeneration)
has a fuel oil allocation.
The following is a qualitative as well as a quantitative
discussion of the possible effects that variations in treatment
technology or design criteria could have on the total capital
costs and annual costs:
TechnoloqY or Design Criteria
1. Use aerated lagoons and sludge de- 1.
watering lagoons in place of the
proposed treatment system.
2. Use earthen basins with a plastic 2.
liner in place of reinforced con-
crete construction, and floating
aerators versus platform-mounted
aerators with permanent-access
walkways.
3. Place all treatment tanks above 3.
grade to minimize excavation, es-
pecially if a pumping station is
required. Use all-
steel tanks to minimize capital
cost.
4. Minimize flow and maximize concen- 4.
trations through extensive in-plant
recovery and water conservation, so
that other treatment technologies
(e.g. incineration) may be economi-
cally competitive.
Cost Differential
The cost reduction could be
60 to 70 percent of the pro-
posed figures.
Cost reduction could be 10
to 15 percent of the total
cost.
Cost savings would depend
on the individual situation.
Cost differential would de-
pend on a number of items,
e.g. age of plant, accessibil-
ity to process piping,
local air pollution
standards, etc.
The recommendation of a level of treatment for BPCTCA comparable
to biological treatment fixes the minimum organic removal
(expressed as BOD5) at approximately 90 percent.
The total cost requirements for implementing BPCTCA effluent
standards are presented in Table VIII-1. Annual cost adjustment
317
-------
factors are also shown for 95, 90, and 85 percent removal BOD5.
These factors are shown below:
Percent
Removal BODS Subcateqory
ABC
95 1.19 1.0 1.0
90 1.00 0.84 0.88
85 0.86 0.72 0.87
All cost data were computed in terms of August, 1971 dollars,
which corresponds to an Engineering News Records Index (ENR)
value of 1580. The model treatment system is activated sludge.
The following costs data were abstracted from the proceeding
table for a flow of 720,000 gpd and the treatment system required
to meet the recommended BPCTCA effluent criteria:
Subcatecforv Capital Cost Annual Costs
$ 1/Y.ear $/iOOO_aal J/lb_BOD5 Percent
Removed BOD5T Removed
A 1,410,000 284,300 1.08 0.78 90
B 2,538,000 487,900 1.86 0.27 95
C 8,144,000 1,657,000 6.31 0.17 95
The following production capacities were selected for calculating
the $/lb BOD5 removed: Subcategory A-10 million Ib/day,
Subcategory B-5 million Ib/day, Category C-1 million lb/dayr
Higher annual costs for Subcategory C reflect present technology
in the industry toward water reuse, which tends to generate very
concentrated waste waters. These waste waters require relatively
longer aeration times and more extensive sludge handling
facilities. As indicated above, any criterion (such as flow)
which does not take into consideration the amount of organic
removal (e.g. Ib BODS removed/day), will not be meaningful in
describing the treatment system. The proceeding data on
decreasing annual unit cost illustrate treatment system economies
of.scale.
Total costs as $/year, $/1000 gallons and $/lb BOD5 Annual costs
and effectiveness data for BPCTCA are shown in Table VIII-2 for
95, 90, and 85 percent removal BODfj. Effluent concentration BOD5
is also shown for each removal efficiency and Subcategory.
Depending on the particular production mix of the individual
plant, floating oil could be a treatment consideration. For that
reason, an API separator was sized for 720,000 gpd. The capital
cost of the separator was then compared with the previously
reported capital cost for the 720,000 gpd treatment system
designed for each category. The following tabulation represents
the percentage increase in capital costs if a separator were
required:
318
-------
Table VIII-1
TOTAL ESTIMATED CAPITAL AND ANNUAL WASTE TREATMENT
COSTS FOR BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE BY PLANT SIZE AND SUBCATEGORY
ORGANIC CHEMICALS MANUFACTURING INDUSTRY
(Activated Sludge Treatment Model)
Production Capacity
Million Ib/day
Product
10
10
5
5
£ 5
to
1.0
1.0
1.0
Costs (1971 Basis)
Size of Treatment Plant
Flow mgd
Subcategory A
0.072
0.72^ 1
Subcategory B
0.072
0.72 2
2.16 3
Subcategory C
0.072 2
0.72 8
2.16 13
*Annual Cost Adjustment
Capital
588,000
,1*10,000
629 ,000
,538,000
,751* ,000
,895,000
,ll*l*,000
,290,000
Factors :
% Reduction BOD5. Subcategory A
95
90
85
1.19
1.00
0.86
Annual*
$/year
107,600
281*, 300
117,700
1*87,900
71*5,800
527,000
1,657,000
2,917,300
Subcategory B
1.00
0.81*
0.72
$/1000 gal
1*.09
1.08
1.86
0.9!*
20.05
6.31
3.70
Subcategory C
1.00
0.88
0.87
% Reduction
BOD5
90
90
95
95
95
95
95
95
$/lb BODJ?
Removed
0.29
0.78
0.06
0.27
0.41
0.05
0.17
0.30
-------
Table VIII-2
NJ
O
Annual Costs
$/year
$71000 gallons
$/lb BOD5
Removed
$/year
$/1000 gallons
$/lb BOD5
Removed
TOTAL COSTS** AND EFFECTIVENESS DATA - BPCTCA
ORGANIC CHEMICALS MANUFACTURING INDUSTRY
SUBCATEGORY A NON-AQUEOUS PROCESSES
Percent
Removal, BOJJ5.
95
*90
85
95
*90
85
95
*90
85
*95
90
85
*95
90
85
*95
90
85
Effluent
Concentration.
mg/liter BOD5.
15
30
45
15
30
45
15
30
45
0.072 mgd
128,OCO
107,600
92,500
4.87
4.09
3.52
0.32
0.28
0.25
Size of Treatment Plant.
mgd
0.72 mgd
338,300
284,300
244,500
1.28
1.08
0.93
0.88
0.78
0.71
2.16 mgd
No Data
Available
SUBCATEGORY B PROCESSES WITH PROCESS WATER CONTACT AS STEAM DILUENT OR ABSORBENT
30
60
90
30
60
90
30
60
90
117,700
98,900
84,700
4.48
3.76
3.22
0.060
0.059
0.049
487,900
409,800
351,300
1.86
1.56
1.34
0.27
0.27
0.22
745,200
626,000
536,500
0.94
0.79
0.68
0.41
0.41
0.33
Basis for recommended effluent limitations
-------
SUBCATEGORY C AQUEOUS LIQUID PHASE REACTION SYSTEMS
Annual Cost
$/1000 gallons
$/lb BOD5
Removed
Percent %
Removal. BODj.
*95
90
85
*95
90
85
*95
90
85
Effluent
Concentration.
mg/liter BOD5.
45
90
135
45
90
135
45
90
135
Size of Treatment Plant, mgd
0.072 mgd 0.36 mgd
527,000 No Data
463,800 Available
458,500
20.05
17.64
17.44
0.050
0.046
0.048
0.72 mgd i
1,657,000
1,458,000
1,441,600
6.31
5.55
5.48
0,17
0.16
0.17
2.16 mgd
2,917,300
2,567,200
2,538,000
3.70
3.26
3.22
6.30
0.28
0.29
-------
Subcategory
A
B
C
Percentage Increase
In Capital Costs
9
5
2
Sludge cake quantities from vacuum filtration corresponding to
each treatment system design are presented in Supplement A. The
following table summarizes the general ranges of sludge
quantities generated by plants in each subcategory:
Subcategorv
Cu yd/year*
A 30 - 200
B 30 - 2,000
C 1,500 - 44,000
*1% net-weight basis
Particular plants within Subcategory C may be amenable to sludge
incineration because of the large quantities of sludge involved.
For example, sludge incineration would reduce the previous
quantities by about 90 percent. Sludge cake is 80 percent water,
which is evaporated during incineration, and more than half of
the remaining (20 percent) solids are thermally oxidized during
incineration. Sludge incineration costs were not evaluated for
those specific cases in Subcategory C, because the particular
economics depend to a large degree on the accessibility of a
sanitary landfill and the relative associated haul costs.
Before discussing the actual variations in costs within each
cateogry, the following discussion is presented to help visualize
the complexities involved in evaluating cost effectiveness data.
Every treatment system is composed of units whose design basis is
primarily hydraulically dependent, organically dependent, or a
combination of the two. The following is a list of the unit
processes employed, and a breakdown of the design basis:
Organically
Dependent
Thickener
Aerobic digester
Vacuum filter
Hydraulically and
Organically Dependent
Aeration basin
Oxygen transfer eqpt.
Air flotation unit
Hydraulically
Dependent
Pump station
API separator
Equalization
Neutralization
Nutrient addition
Sludge recycle pump
Clarifier
The annual cost associated with the hydraulically dependent unit
processes is not a function of effluent level. On the other
hand, the sizing of the organically dependent units should
theoretically vary in direct proportion to the effluent level:
e.g. reducing the BOD5 removal from 95 tq 85 percent should
reduced the sizes of the sludge handling equipment by
322
-------
approximately 10 percent. However, there are two complicating
factors: 1) only a relatively few sizes of commercially available
equipment; and 2) broad capacity ranges. These two factors, es-
pecially in regard to vacuum filters, tend to negate
differentials in capital cost with decreasing treatment levels.
The relationship between design varying contaminant levels and
the design of aeration basins and oxygen transfer equipment is
somewhat more complex. The levels are dependent on the hydraulic
flow, organic concentration, sludge settleability, and the
relationship between mixing and oxygen requirements. For
example, to reach a particular effluent level, the waste water's
organic removal kinetics will require a particular detention time
at a given mixed-liquor concentration. The oxygen transfer
capacity of the aerators may or may not be sufficient to keep the
mixed liquor suspended solids in suspension within the aeration
basin. Therefore, the required horsepower would be increased
merely to fulfill a solids mixing requirement. Alternatively,
the oxygen requirements may be such that the manufacturer's
recommended minimum spacing and water depth requirments would
require that the basin volume be increased to accommodate oxygen
transfer requirements.
Capital and annual costs for new sources are presented in Table
VIII-3. The treatment model used, in developing the costs is
activated sludge followed by dual media filtration. The same
annual cost adjustment factors applicable to BPCTCA are also
relevant to new sources due to the similarity of these systems.
As expected, the end-of-pipe costs are not appreciably higher
than those for BPCTCA. The following information was extracted
from Table VII-3
Subcategory^ Capital Costs Annual Costs
$ ~$7year$/1000 gal $/lb~JQD5
gemovaj.
A l,524tOOO 302,900 1.15 0.83
B 2,652,000 511,000 1.94 0.28
C 8,258,000 1,710,700 6.51 0.17
The following production capacities were selected for calculation
of the $/lb BOD5 removed: Subcategory A-10 million Ib/day,
Subcategory B-5 million Ib/day, Subcategory C-1 million Ib/day
and
Capital and annual costs are calculated for the best available
technology economically achievable model treatment systems.
These systems are described as follows: two stage biological
treatment plus dual media filtration and activated carbon.
Activated carbon treatment for Subcategories A and B consists of
fixed bed columns. For Subcategories C pulsed bed columns with
a carbon regeneration system are recommended. Costs are
presented in Table VIII-4 for the BATEA model treatment system.
The following information is extracted from this table for a
720,000 gallon per day facility.
323
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Table VIII-3
TOTAL CAPITAL AND ANNUAL WASTE TREATMENT COSTS FOR
NEW SOURCES WITH BEST AVAILABLE DEMONSTRATED
CONTROL TECHNOLOGY BY PLANT SIZE AND SUBCATEGORY
ORGANIC CHEMICALS MANUFACTURING INDUSTRY
(Activated Sludge and Filtration Treatment Model)
Production Capacity
Million Ib/day
Product
10
10
Costs (19T1 Basis)
Size of Treatment Plant Capital
Flow mgd
Subcategory A
0.072
0.72
Subcategory B
0.072
0.72
2.16
Subcategory C
0.072
0.72
2.16
$
632,000
l,52!t ,000
673,000
2,652,000
3,93^,000
2,939,000
8,258,000
13,^70,000
Annual *
$/year
11^,300
302,900
12U,800
511,000
781,800
51*3,000
1,710,700
3,013,000
$/1000 gal
U.3U
1.15
U.75
1.91*
0.99
20.66
6.51
3.82
% Reduction
BOD.5
90
90
95
95
95
95
95
95
$/lb BOD5
Removed
0.31
0.83
0.07
0.28
0.43
0.055
0.17
0.31
*Annual Cost Adjustment Factors:
% Reduction BOD5 Subcategory A
95
90
85
1.19
1.00
0.86
Subcategory B
1.00
1.8U
0.72
Subcategory C
1.00
0.08
0.87
-------
Subcategory Capital Cost Annual Costs
$ $/vear $/1000 gal $/lb COD
Removal
A 2,498,000 477,100 1.82 0.47
B 3,626,000 682,500 2.60 0.11
C 10,410,000 2,110,500 8.03 0.10
The following production capacities were selected for calculation
of the $/lb COD removal: Subcategory A-10 million Ib/day,
Subcategory B-5 million Ib/day, Subcategory C-1 million Ib/day
325
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Table VHI-4
TOTAL ESTIMATED CAPITAL AND ANNUAL WASTE TREATMENT COSTS FOR
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE'
(1983 STANDARD) BY SIZE OF PLANT AND SUBCATEGORY
ORGANIC CHEMICALS MANUFACTURING INDUSTRY
(Biological Treatment»Filtration, and Activated Sludge Treatment Model)
Production Capacity
Million Ib/day
Product
10
10
5
5
lAl 5
K> J
ON
1
1
1
Costs (1971 Basis)
Size or Treatment r.
Flow mgd
Subcategorv A
0.072
0.720
Subcatepory B
0.072
0.72
2.16
Subcategory C
0.072
0.72
2.16
L*"L Capital
$
861,000
2,1*98,000
902,100
3,626,000
5,853,000
3,1*66,100
10,1*10,000
17,663,000
Annual
$/year
11*3,500
1*77,100
153,900
682,500
1,210,500
607,300
2,110,500
1*, 028, 700
$/1000 gal
1.82
5.86
2.60
1.53
23.10
8.03
5.11
Overall % Removed
COD
90
90
91*
91*
91*
I
&/lb COD
Removed
0.14
0.47
0.025
0.11
0.19
0.029
0.10
0.19
-------
SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY
AVAILABLE - EFFLUENT LIMITATIONS
Best practicable control technology currently available (BPCTCA)
for the organic chemical industry is based on the utilizations of
both in process controls and end-of-process treatment
technologi es.
Alternative in-process controls commensurate with BPCTCA include
the implementation of process observation and sampling to
determine the quantity, compositions, concentration, and flow of
the process waste streams. Such waste characterization studies
logically lead to the selection of various process waste sources
for segregation. Exemplary plants within the industry segregate
contaminated contact process water streams from non-contaminated
streams such as cooling water. This practice appreciably reduces
the waste volume to be treated in a centralized waste treatment
plant. In addition process water streams are segregated on the
basis of the ease with which certain constituents can be
recovered as well as the ease with which the wastes can
ultimately be treated.
Process modification consistant with BPCTCA include the
substitution of nonaqueous media in which to carry out the
reaction or to purify the products. In some cases aqueous waste
by-products are eliminated by changes in the reactants, reactant
purity, or catalyst system. Where waste is used in the process,
its use should be restricted and the possibility of using
recycled or reused water should be investigated. Examples of
this practice include recycle between an absorber and a steam
stripper, countercurrent washing techniques, and the collection
of vacuum-jet condensate, rain water and floor water for reuse.
Equipment associated with the separation of an organic phase from
an aqueous phase, such as decanters, are provided with backup
coalescers or polishing filters for the aqueous phase. Direct
vacuum-jet condensers are replaced with indirect condensers or
vacuum pumps.
In addition to waste reductions obtained through segregations and
process change, exemplary plants using BPCTCA combine recovery of
products and by-products with waste water purifications. The
recovery of chemicals from the waste waters includes both the
physical separation of chemicals from the waste water as well as
subjecting the waste water to additional chemical reactions that
will render them more aminable to recovery and purification.
Physical separation processes utilized by exemplary plants
include adsorption, solvent extration, and distillation.
Adsorbents in use include activated carbon, zeolites, and
synthetic resins. The adsorbed chemicals are recovered by
desorption which also serves to regenerate the saturated
adsorbent. One system for the non-destructive, inplace,
327
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regeneration of activated carbon is the use of pH change to cause
the adsorbed chemicals to desorb. Such a system has been used
successfully to recover phenol and acetic acid by the addition of
caustic.
Solvent extraction is used for the recovery of phenol from the
waste water of the cumene process for phenol manufacture.
Solvent extration is practiced when the chemical can be extracted
into a solvent already in use in the process. Excess solvent is
steam stripped from the effluent. Effluent phenol concentration
is expected to average less than 1 mg/liter from the treatment
system.
Distillation is used to recover by-products from reduced volume
waste water streams by steam stripping. This concentration step
rpoduces an overhead condensate containing the strippable organic
substances and water. This condensate is then reused in the
process. Exemplary plants utilizing either solvent extraction or
steam distillation of waste waters usually apply additional
polishing treatment to the effluent to removed the small
remaining quantities cf organic substances.
Chemical reactions such as chlorination, hydrolysis, cracking,
dechlorination and dealkylation have been used to convert
impurities into forms suitable for subsequent physical
separations. A typical example is the hydrolysis of aromatic
tars with caustic with subsequent acidification and physical
separation of the organic and aqueous phases.
It is not possible to delineate a specific sequence or
combination of in-process controls which could be considered as
an across the board definition of BPCTCA. However, methods taken
from those previously described and end-of-process treatment
systems should enable all processes within each category to
attain the BPCTCA effluent limitations. Mean raw waste loads
were calculated for each subcategory group and are shown in Table
IX-1. These raw waste loads were the basis for determining the
BPCTCA effluent limitations. This data is also presented in
Sections IV and V (Tables V-l, V-2 and V-3).
End-of-pipe treatment technologies commensurate with BPCTCA are
based on the ulitization of biological systems including the
activated sludge process, extended aeration, aerated lagoons,
trickling filters, and anaerobic and faculative lagoons. These
systems include additional treatment operations such as
equalization, neutralization, primary clarification with oil
removal, and nutrient addition. Because the removal of certain
organic materials may require the utilization of high
concentrations of biological solids, effluent polishing steps
such as coagulation, sedimentation, and filteration are
considered as commensurate with BPCTCA. Effluent suspenced
solids are expected to be maintained below 60 mg/liter for the
maximum 30 average limitation and 135 mg/liter for the maximum
daily limitation.
328
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Phenols limitations are based upon an average effluent 0.01
kg/kkg production for three product-process segments: cumene
process, bisphenol A and p-cresol manufacturing. This represents
99.9 percent reduction of the standard raw waste load of phenols
for these processes (10 kg/kkg production) .
Effluent limitations for BPCTCA have been listed in Table II~2.
Table IX«1 contains a summary of the raw waste load data for each
subcategory group. Detailed summaries have been presented in
Tables Y-l, V-2 and V-3. Table IX-1 shows the method utilized in
deriving BPCTCA effluent limitation guidelines.
It should be noted that because biological systems have been
proposed as the mode of treatment consistent with BPCTCA, the
BOD5 parameter is controlling and is the only one for which the
effluent limitations are to be applied. It may be desirable in
certain cases to establish limitations for COD or TOC instead of
the BOD5 parameter. The feasibility of such a substitution can
only de determined on an individual basis after adequate
correlation has been established.
Effluent limitations are specified on the bases of the maximum
for any one day and the maximum average of daily values for any
period of 30 consective days. The rationale and basis for
determining the daily amd monthly maximum variations are
presented in Section XIII.
329
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TABLE IX - 1
Summary of Mean Raw Waste Load Data (RWL) and Bases
for Effluent Limitations
BPCTCA
-BOD- (4)
Mean
RWL
kg/kkg
0.1
0.38
1.75
0.56
3.03
25.5
68.5
Reduction
Factor
N.S.
N.S.
N.S.
N.S.
0.96
0.99
0.99
Mean *••
BPCTCA
Effluent kg/kkg
0.01<3)
0.'21 (3)
0.062(3)
0.12
0.25
0.68
COD
Mean
RWL, kg/kkg
0.22
4.0
3.85
2.59
6.75
30.1
195
Reduction
Factor
0.74
0.74
0.74
0.74
0.74
0.74
0.74
Mean l
BPCTCA Effluent
kg/kkg
0.057
1.04
1.00
0.67
1.75
7.83
50.7
Subcategory Mean Process
Waste Flow,
liter/kkg
A 500 (5)
B! 1,460
82 10,550
CX 3,119
C2 4,103
C3 1,284
C4 23,819 (5)
U.S. indicates value not specified (less than 93 percent removal BODS required for 20 mg/liter BODS effluent).
(1) BOD5 is the control oxygen demand parameter for which effluent limits are calculated on the daily "iximum
basis (X 4.5) and maximum 30 day average basis (X 2.0).
(2) COD guidelines are calculated on basis of average performance of exemplary plants (74 percent removal COD)
and variability factors for daily maximum (X 3.4) and maximum 30 day average (X 2.0).
(3) Value derived by the mean flow X 20 mg/liter BODS
(4) BODS is the control oxygen demand parameter.
(5) Median value
0.015
0.044
0.32
0.094
0.12
0.034
0.63
Effluent limits for phenols are applicable to the cumene process (Subcategory C2), bisphenol A (Subcategory C3
and P - cresol (Subcategory C4) at average effluent concentration< 1 mg/liter (0.01 kg/kkg). Effluent limitations
are based on daily maximum ( x 4.5 ) and maximum 30 day average ( X 2.0 ).
-------
SECTION X
Best Available Technology Economically
Achievable (BATEA)
The best available technology economically achievable is based
upon the most exemplary combination of in-process and end-of-
process treatment and control technologies.
The full range of treatment and control technologies which are
applicable to the major organic chemicals segment of the organic
chemicals manufacturing industry has been described in Section
VII. This level of technology is primarily based upon
significant reductions in the chemical oxygen demand (COD), as
well as the biochemical oxygen demand pollutant parameters.
The model end-of-process treatment system has been determined to
be biological plus additional activated carbon treatment. It
must be noted that this does not preclude the use of activated
carbon as an in-process treatment in lieu of its use at the end-
of-process. This may be desirable when product can be recovered
or when harmful pollutants must be removed prior to treatment.
Two model systems are presented for cost estimation purposes:
1. Activated sludge treatment followed by filtation and
activated carbon adsorption in fixed-bed columns
(applied to Subcategories A and B)
2. Activated sludge treatment followed by carbon adsorption
in pulsed bed columns (applied to Subcategory C).
The performance of these treatment systems has been discussed in
Section VII - Control and Treatment Technologies.
These systems or equivalent combinations can provide the
reduction in BOD5 and COD pollutant parameters as listed below:
BOD 90 percent reduction (BATEA is
10 percent of BPCTCA effuent)
COD 69 percent reduction (BATEA is
31 percent of BPCTCA effluent)
Effluent limitations guidelines for BATEA were calculated by
appying these reduction factors to average effluent for BPCTCA.
These are specific subcategories where the direct use of these
reduction factors will still result in effluent concentrations
which are below the capabilities of the control systems
considered as BATEA. In the case of Subcategories A, Bl, B2, Cl,
C2, and CU, effluent limitations guidelines for BATEA were
obtained by applying minimum concentrations of 10 mg/liter BODS
to the mean waste water flow for each subcategory group. COD
effluent limitations were derived in a similar manner for
Subcategories A and B2 with a mean COD effluent concentration of
50 mg/liter.
331
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It is noted that the BATEA requires suspended solids removal to
an average concentration of 15 ing/liter through the use of
filtration. This concentration limitation should again be
applied to the tota^. effluent from any multi process facility.
Effluent limitations for phenolic compounds are based upon an
achievable concentration of 0.1 mg/liter phenolic compounds by
the model BATEA treatment system. These limitations apply to the
following product-process segments: cumene process, bisphenol A
and p-cresol manufacturing. Effluent limitation for phenols also
assure an achievable reduction of 99.99 percent of the initial
raw waste values.
Effluent limitations are based on the daily maximum and maximum
30 day average basis. Variability factors applicable to the
model system were based upon engineering judgements of the
variability associated with the 99/50 ratio of probability of
occurrence. For the COD parameter the following factors apply to
the daily maximum limitation and the maximum 30 day average
limitations: 2.5 and 1.8 respectively. For BOD5, TSS and phenols
the applicable ratios are 3.0 and 1.7 respectively.
332
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Table X-l
Summary of Basis for BATEA Effluent Limitations
Subeategory
B2
Cl
C2
C3
C4
Average BPCTCA
Effluent
0.01
0.029
0.21
0.062
0.12
0.25
0.68
-BOD5-
Reduction
Factor
N.S.
N.S.
N.S.
N.S.
N.S.
0.90
N.S.
Average (3)
BATEA
Effluent
0.005 (!)
0.014 (D
0.10 (1)
0.03 CD
0.04 CD
0.025
0.21 (1)
Average BPCTCA
Effluent
0.057
1.04
1.00
0.67
1.75
7.83
50.7
-COD-
Reduction
Factor
N.S. (2)
0.69
N.S. («
0.69
0.69
0.69
0.69
Average^/
BATEA
Effluent
0.025
0.32
0.53
0.21
0.54
2.43
15.7
TSS
BATEA Effluent OJ
@ 15 mg/liter
0.0075
0.022
0.16
0.047
0.062
0.017
N.S. indicates value not specified (less than 90% removal BODS and 69% removal COD.
(1) Value derived by minimum achievable effluent concentration of 10 mg/liter BOD5.
(2) Value derived by mimimum achievable effluent concentration of 50 mg/liter COD.
(3) Variability factors for daily maximum limit (X 3.0) and maximum 30 day average limit (X 1.7) are used to
derive limitations.
(4) Variability factors for daily maximum limit (X 2.5) and maximum 30 day average limit (X 1.8) are used to
derive limitations.
Phenols limits for cumene process (Subeategory £2), bisphenol A (Subeategory 03) and p cresol (Subeategory
C4) based on average concentration of 0.1 mg/liter (0.001 kg/kkg) and variability factors for daily maximum
(3.0) and maximum 30 day average (1.7)
-------
SECTION XI
New Source Performance Standards
Determination of the best available demonstrated control
technology (BADCT) for new major organic sources involves the
evaluation of the most exemplary in-process control measures with
exemplary end of process treatment. Some major in-process
controls which were fully desicribed in Section VII are
applicable to new sources as follows:
(1) The substitution of non-contact heat exchangers
using air, water or refrigerants for direct
contact water cooling equipment (barometric condensers);
(2) The use of nonaqueous quench media, e.g. hydrocarbons
such as furnace oil, as a substitute for water,
where direct contact quench is required;
(3) The recycle of process water, such as between absorber
and stripper;
(4) The reuse of process water (after treatment) as make-up
to evaporative cooling towers through which
noncontact cooling water is circulated;
(5) The reuse of process water to produce low
pressure steam by non-contact heat exchangers in reflex
condensers or distillation columns;
(6) The recovery or spent acid of caustic solutions for reuse;
(7) The recovery and reuse of spent catalyst solutions;
(8) The use of nonaqueous solvents for extraction of products.
Although these control measures are generally applicable, no
attempt was made to identify all of these or any single one as
universally applicable.
The end of process treatment model has been determined to be
biological treatment with the additional suspended solids removal
by clarification, sedimentation, sand and/or dual medai
filtration. The following system is proposed for cost estimating
purposes and does not limit the use of equivalent systems: two
stage activated sludge plus dual medium filtration. These costs
are presented in Section VIII.
Although biological treatment has been described as the basis for
the BADCT, it is recognized that chemical-physical systems such
as activated carbon may also be employed as an end-of-process
technology or as an in-process or by-product recovery system. It
may also be necessary to remove certain wastes which are toxic to
or interfere with biological waste treatment systems by in-
process chemical-physical control processes.
Reductions in the BODS and COD parameters were obtained through
laboratory evaluations of the effluent from activated sludge
treatment systems sampled during the Phase II study. These
334
-------
results have been incorporated in the Phase I report and are
indicated in Section VII, Control and Treatment Technology.
These reductions were applied to the effluent obtained from
BPCTCA and are listed in as follows:
BODS 17% reduction (BADCT effuent is 83% of BPCTCA effluent).
COD 20% reduction (BADCT effluent is 80% of BPCTCA effluent).
As with BPCTCA, the major oxygen demand pollutant parameter is
BODS for which effluent limitations guidelines are established.
TSS limitations are based upon an achievable concentration of 15
mg/liter. Phenolic compounds are limited for the cumene process,
bisphenol A and p-cresol manufacturing. These limits were
established on the same basis as BPCTCA with an achievable
effluent concentration of less then 1 mg/liters. This represents
a 99.9 percent reduction of the average raw waste load for
phenolics in each of these product-process segments.
The variability associates with the BADCT model treatment process
was determined to be the same as that for BPCTCA since both
systems are identical except for filtration which is added to the
biological system for BADCT. The factors which represent the
99/50 ratio of probability of qccurrence for daily maximum and
maximum 30 day average limitations are 4.5 and 2.0 respectively
and apply to the average limitations for BODS, phenols, and TSS.
335
-------
Subcategory
B2
Cl
C2
C3
C4
-BOD- (3)
Average BPCTCA
Effluent, kg/kkg
0.01
0.029
0.21
0.062
0.12
0.25
0.68
Reduction
Factor
0.17
0.17
0.17
0.17
0.17
0.17
0.17
Average
Effluent,
0.008
0.024
0.17
0.05
0.10
0.21
0.57
BADCT '
kg/kkg
TABLE XI -1
Summary of Basis for New Source Standard (BADCT)
"(I)
COD
Average BPCTCA
Effluent, kg/kkg
0.057
1.04
1.00
0.67
1.75
7.83
50.7
Reduction
Factor
0.20
0.20
0.20
0.20
0.20
0.20
0.20
Average BADCT (
Effluent kg/kkg
0.046
0.83
0.80
0.54
1.4
6.26
40.56
(1) Variability factors for the daily maximum (X 4.5) and maximum 30 day average (X 2.0) are used to
derive effluent limitations.
(2) Variability factors for daily maximum guideline (X 3.4) ar.d maximum 30 day average guideline (X 2.0)
were employed.
Average (1)
TSS
15 ms/liter
0.0075
0.022
0.16
0.047
0.062
0.017
0.32
(3) BOD5 is the control oxygen demand parameter.
Phenols limits for rumene process (Subcategory C2), bisphenol A (Subcategory 63) and p cresol
(Subcaregory €4) art based upon an average concentration of "L mg/liter 10.01 kg/kkg in the
effluent and variability factors for daily max (X
-------
SECTION XII
PRETREATMENT GUIDELINES
Pollutants from specific processes within the organic chemicals
industry may interfere with, pass through, or otherwise be incom-
patible with a publically owned treatment works. The following
section examines the general waste water characteristics of the
industry and the pretreatment unit operations which may be
applicable.
A review of the waste water characteristics indicated that
certain products can be grouped together on the basis of
pollutants requiring pretreatment. Accordingly, the previously
determined subcategories were divided into two Sub-groups as
follows:
Subgroup 1 Subgroup 2
Sutcategory A Subcategory C
Subcategory B
The principal difference in the general characteristics of the
process waste waters from the manufacture of chemicals in these
two Sub-Groups is that the waste waters of Subgroup 1 are more
likely to include significant amounts of free and emulsified
oils, whereas the wastewaters of Subgroup 2 are more likely to
include significant amounts of heavy metals.
Detailed analyses for specific products in the industry are
presented in Supplement B.
The types and amounts of heavy metals in the waste water depend
primarily on the manufacturing process and on the amounts and
types of catalysts lost from the process. Most catalysts are
expensive and, therefore, recovered for reuse. Only
unrecoverable catalysts (metals), generally in small
concentrations, appear in the waste water. The products and
processes in Subgroup 2 are most likely to have metals in their
waste water.
The manufacture of acrylonitrile (Subcategory C) produces a
harmful waste water which is difficult to treat biologically.
The harmful characteristics have been attributed to the presence
of hydrogen cyanide in excessive quantities (500 to 1,800 mg/1).
In addition, the waste water is generally acidic (pH U to 6) and
contains high concentrations of organic carbon. These waste
waters are generally segregated from other process wastes and
disposed of by other means (e.g. incineration), and they are not
generally discharged to municipal collection systems. For these
reasons, the pretreatment unit operations developed in the
following section do not include the process waste waters from
the manufacture of acrylonitrile.
337
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Table XII-I shows the pretreatment unit operations which may be
necessary to protect joint waste water treatment processes.
Oil separation may be required when the oil content of the waste
water exceeds 10 to 15 mg/1.
The heavy metals present in organic chemical wastes are in many
cases so low in concentration that metals removal is not required
from the standpoint of treatability characteristics. However the
effluent limitations for metals and harmful pollutants may
require additional pretreatment (chemical precipitation) for
removal of these materials.
The pretreatment unit operations generally consist of
equalization, neutralization, and oil separation. In addition,
phenol recovery (to reduce the phenol concentration) and spill
protection for spent acids and spent caustics may be required in
some cases.
Biological Treatment Inhibition
The survey data collected during the sampling program were
examined from the standpoint of the occurrence of specific
pollutants which may inhibit biological treatment. This review
indicated agreement with the results of the comprehensive study
of biological treatment in EPA's Federal Guidglines-Pretreatment
2.1 2i§£^§£3S§ £°. Publicly Owned Treatment Works, and no changes
in the lists of inhibitory pollutants are warranted.
The following is a brief discussion of the reference material
used to determine the phenol and iron values. Phenol is
biologically degradeable in an acclimated system. McKinney, for
example, reports that concentrations as high as 2,000 to 3,000
mg/1 of mixed phenolic substances are degradable in a properly
designed system. However, concentrations as low as 50 mg/1 can
inhibit biological treatment if the organisms are not properly
acclimated. Nemerow has reported in his literature review that
concentrations of iron on the order of 5 mg/1 can be inhibitory
to anaerobic sludge digestion.
Concentrations of iron on the order of 5 mg/1 have been reported
by Nemerow to be inhibitory to anaerobic sludge.
338
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SECTION XIII
ALLOWANCE FOR VARIABILITY IN TREATMENT PLANT PERFORMANCE
As previously discussed in End-of-Pipe Treatment in Section VII,
the historic treatment plant data were analyzed on the basis of
monthly averages. Subsequent effluent limitations for BPCTCA,
BADCT, and BATEA were based on both the maximum for any one day
(daily maximum) and maximum average of daily values for any
period of thirty consecutive days.
Daily historic data from two biological treatment plants treating
Subcategory C waste waters were reviewed; weekly and consecutive
thirty day averages were calculated, and then the data were
analyzed statistically. The results of these analyses are
summarized in Table XIII-1.
The significance of the data is that a biological treatment plant
on the average (50% of the time) is producing an effluent with a
BOD5 concentration of 20 mg/1, will also produce an effluent with
90 ing/1 of BOD5 5% of the time.
Variations in the performance of a treatment plant are
attributable to one or more of the following:
1. Seasonal variations in waste water temperature
which either accelerate or depress the biological
kinetics.
2. Variations in the sampling technique or in the
analytical procedures.
3. Variations in one or more operating parameters, e.g.,
amount of sludge recycle, dissolved oxygen in the
aeration basin, etc., which can affect performance.
U. The relationship of the plant's hydraulic and organic
loading to the plant's design values. The degree
of underloading or overloading could be reflected
in performance.
5. In-plant process bottle necking which can be responsible
for degrading the effluent when seasonal loadings
strain these particular facilities. For example,
inadequate sludge handling facilities during peak
periods of sludge production may require modified
wasting of the sludges. The overall effect would
manifest itself in an increase in TSS and BOD5 in
the plant effluent.
These variations are purely a function of the treatment plant
design and performance. They will still occur even if the
treatment plant has provisions for equalization of variations in
the influent raw waste load which it receives.
339
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Table XIIl-l
Effluent Variation of Biological
Treatment Plant Effluent
CO
-p>
o
Probabi1i ty
of Occurrence
% less than
or e?ual to
10
20
30
to
50
60
70
80
90
95
99
Da i 1 y
mg/L
6
9
13
16
20
25
30
to
60
90
160
BCD
Weekl y
mg/L
10
13
16
17
20
26
26
30
to
50
70
Monthly
mg/L
12
It
16
18
20
22
25
29
35
to
55
Da i 1 y
mg/L
180
250
320
390
t70
570
690
870
1200
1600
2500
COD
Weekly
mg/L
270
350
tl5
t85
555
6to
7to
880
1130
itoo
2000
Monthly
mg/L
too
con
s->v
560
630
700
780
880
1000
1230
lt30
I9to
Da i 1 y
mg/L
55
67
78
88
100
110
130
150
180
220
300
TOC
~^i7L*
65
7t
82
90
98
105
115
1JO
150
170
210
Monthly
mg/L
67
76
82
89
96
103
ill
122
ito
150
185
-------
Selected statistical data in Table XIII-1 were examined to
compare the ratios of the 99% probability of occurrence to the
50% probability of occurrence, the 95% to the 50% value, and the
90% to the 50% value, as shown below:
Ratio_of BQD5r Thirty Consecutive
Probability Daij.y Weekly Day Period
99/50 8.0 3.5 2.7~
95/50 U.5 2.5 2.0
90/50 3.0 2.0 1.7
COD
99/50 5.3 3.6 2.8
95/50 3.4 2.5 2.0
90/50 2.5 2.0 1.8
TOC
99/502 3.0 2.2 1.9
95/50 2.2 1.7 1.6
90/50 1.8 1.5 1.4
Plants A and B have primary settling and nutrient addition. In
Plant A, there are four parallel trains of 3 aeration basins each
for a total of 12 basins. Flow from each of the parallel trains
goes to a clarifier. Additional organic and solids removal is
accomplished by using an aerated polishing lagoon.
Plant B has two parallel trains of 3 aeration basins each for a
total of 6 basins. Clarification and air flotation are provided
in order to reduce the aeration basin mixed liquor (MLSS) which
average about 7-8,000 mg/1 of organics components and solids.
Plant A is located in the southern United States and not subject
to extreme seasonal temperature fluctuations. Plant B is in the
Midwest and it has been found necessary to add steam to the
aeration basin during the winter to maintain the basin
temperature above 45°F.
Daily analyses of TOC and BOD were available from Plant A and
only COD data were available from Plant B. Weekly and thirty
consecutive day period averages were calculated and then the data
were analyzed statistically. The results of the analyses were
summarized in Table XIII-2.
Treatment plant variability factors were used in deriving time
based limitations for the following pollutant parameters: BODS,
TSS, and phenols. These variability factors are 4.5 and 2.0
respectively, for the daily maximum and maximum 30 average
limitations. Although these factors represent the apparent 95/50
ratio of probability of occurrence, it is assumed that an
effectively higher probability, 99/50 ratio is actually
representative of these factors. The reasons for this are as
follows:
341
-------
1. Data used in caculating the variability of BODS contain
three weeks of unstabilized conditions for the model treatment
system. Excluding these data will provide an effectively higher
probability of occurrence for the variability factors associated
with the apparent 95/50 ratio.
2. The variability factors selected closely agree with the
factors associated with the 99/50 ratio of probability of
occurrence for other chemical industry treatment plants in the
plastics and synthetic products and petrochemical segments.
342
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SECTION XIV
ACKNOWLEDGEMENTS
This report was prepared for -the Environmental Protection Agency
by the staff of Roy F. Weston Co. under the direction of Mr.
James Dougherty, Project Director. The following individuals of
the staff of Roy F. Weston Co. made significant contributions to
this effort:
Mr. David Smallwood, Project Manager
Mr. Charles Mangan, Project Engineer
Mr. Kent Patterson, Project Engineer
Mr. James Weaver, Project Engineer
Dr. Sun-nan Hong, Project Engineer
The technical assistance provided by Chem Systems Inc. is also
acknowledged.
Mr. John A. Nardella, Project Officer, Effluent Guidelines
Division, contributed to the overall supervision of this study
and preparation of the draft report.
Mr. Allen Cywin, Director, Effluent Guidelines Division, and Mr.
Walter J. Hunt, Chief, Effluent Guidelines Development Branch,
offered guidance and helpful suggestions. Members of the Working
Group/Steering Committee who coordinated the internal EPA review
are acknowledged:
Mr. Walter J. Hunt, Effluent Guidelines Division
Mr. John Nardella, Effluent Guidelines Division
Mr. George Rey, Office of Research and Development
Dr. Thomas Short, Ada Laboratory, Office of Research
and Development
Mr. John Savage, Office of Planning and Evaluation
Mr. Alan Eckert, Office of General counsel
Mr. Wayne Smith, NFIC, Denver
Mr. John Lank, Region IV, Atlanta
Mr. Joseph Davis, Region III, Philadelphia
Mr. Ray George, Region III, Philadelphia
Mr. Albert Hayes, Office of Solid Waste Management
Mr. Frank Kover, Office of Toxic Substances
Acknowledgement and appreciation is also given to the secretarial
staffs of both Effluent Guidelines Division and Roy F. Weston Co.
for their efforts in the typing of drafts, necessary revisions,
and final preparation of the effluent guidelines document.
Appreciation is especially given to the following:
Ms. Kay Starr, Effluent Guidelines Division
Ms. Chris Miller, Effluent Guidelines Division
Ms. Brenda Holmone, Effluent Guidelines Division
Ms. Jane Mitchell, Effluent Guidelines Division
343
-------
Ms. Janet Gilbert, Roy F, Weston Co.
Ms. Kit Krickenberger, Effluent Guidelines Division
Ms. Sharon Ashe, Effluent Guidelines Division
Ms. Nancy Zrubek, Effluent Guidelines Division
Appreciation is also extended to both the Manufacturing Chemists'
Association and the Synthetic Organic Chemical Manufacturers'
Association for the valuable assistance and cooperation given to
this program. Appreciation is also extended to those companies
which participated in this study:
Allied Chemical Corp.
American Cyanamid Corp.
Amoco Chemical Corp.
Atlantic Chemical Corp.
Celanese Corp.
Chemplex Corp.
Crompton-Knowles Co.
Dow Corp*
Dow Badische Corp.
E.I. duPont de Nemours Co.
Eastman Kodak Corp.
Tennessee Eastman Div.
Texas Eastman Div.
Ethyl Corp.
Gulf Oil Corp.
Kay Fries Chemical Co.
Mobil Corp.
Monochem Corp.
Sherwin-Williams Corp.
Sinclair Koppers Corp.
Southern Dyestuffs Co.
Tenneco Corp.
Phillips Petroleum Corp.
Union Carbide Corp.
344
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SECTION XV
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Jaeschke, L., and Trobisch, K., "Treat HPI Wastes Biologically."
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Kumke, G.W., conway, R.A., and Creagh, J.P., "Compact Activated
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348
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349
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Summary of EPA Research Development and
Demonstration Projects Utilizing Activated
Carbon Adsorption Technology
(1) EPA Advanced Wastewater Treatment Demonstration
Grant No. 17080 EDV, "Tertiory Treatment by Lime
Addition at Santee, California, "Santee County
Water District, Santee, California, January 12, 1966.
(2) EPA Advanced Wastewater Treatment Demonstration Grant
No. 802719, "Interim Wastewater Treatment Plant
Demonstration, Covington Kentucky, "Campbell and Kenton
Counties Sanitation District, July 23, 1973.
(3) EPA Advanced Wastewater Treatment Demonstration
Grant No. 80266, "Physical Chemical Treatment Evaluation,"
Metropolitan Sewer Board Minneapolis, St. Paul Minn.,
January 1 , 1974.
(4) EPA Storm and Combined Sewer Research Grant No. 802433
Rice University, Houston, Texas, "Maximum Utilization of
Water Resources in a Planned Community, July 16, 1973.
(5) EPA Industrial Research Grant No. 17020 EPF, "Adsorption
from Aqueaus Solution," University of Michigan, Ann Arbor
Michigan, October 1, 1969.
(6) EPA Industrial Demonstration Grant No. 12050GXE, "Treatment
of Oil Refinery Wastewaters for Reuse Using a Sand Filter
Activated Carbon System, B.P. Oil Company, Marcus Hook,
Pennsylvania January 1, 1971.
(7) EPA Industrial Demonstration Grant No. 12020EAS "Recondition
and Reuse of Organically Contaminated Waste Sodium Chloride
Brines, Dow Chemical Company, Midland, Michigan, January 6, 1969.
(8) EPA Advanced Wastewater Treatment Demonstration Grant No.
11060 EGP," Advanced Waste Treatment at Painesville, Ohio,
City of Painesville, Ohio, December 15, 1969.
(9) EPA Research Grant No. 12040 HPK, "Organic Compunds
in Pulp Mill Lagoon Discharge," University of Washington.
(10) EPA Research Study No. 21ACU07, "Development of Analog
Chemical Treatment," EPA NERC Cincinnati, Ohio, January 7, 1972.
350
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(11) EPA Research Study No. 21 ABD 06, "Process Modification
to Enhance Removal of Heavy Metals, NERC Cincinnati, Ohio,
January 4, 1973.
(12) EPA Advanced Wastewater Treatment Demonstration Grant
No. 11010 EHI, "Teritory Treatment of Combined Storm
Water Sanitary Relief Discharge and Sewage Treatment
Plant Effluent," Sanitary District of East Chicago,
January 12, 1966.
(13) EPA Advanced Waste Treatment Demo Grant No. 11010 DAB,
"Chemical Clarification and Carbon Filtration and Adsorption
as Secondary Treatment for Rocky River Wastewater Treatment
Plant, Cuyahoga County, Ohio Sewer Dicstrict, August 16, 1968.
(14) EPA Industrial Demonstration Grant No. 801431, "An Activated
Carbon Secondary Treatment System for Purification of a
Chemical Plant Wastewater for maximum Reuse, "Hercules, Inc.,
January 3, 1973.
(15) EPA Demonstration Grant No. 800554, "Carbon Adsorption and
Regeneration for Petrochemical Waste Treatment," University
of Missouri, Columbia, Misssouri, January 6, 1972.
(16) EPA Research Contract No. 68-01-0183 "Physical Chemical
Treatment of Municipal Waste," Envirotech Corporation
Salt Lake City, Utah, July 4, 1972.
(17) EPA Research Contract No. 68-01-0137, "Development
and Demonstration of Device for on Board Treatment
of Wastes from Vessels," AWT Systems Inc, Wilmington
Delaware, March 6, 1971.
(18) EPA Research Contract No. 68-01-0130, "Device for On
Board Treatment of Wastes from Vessels," Fairs banks
Morse, Inc., Beloit, Wisconsin, March 6, 1971.
(19) EPA Research Contract No. 68-01-0104, "Recreational
Water Craft Waste Treatment System," Ametek/Calmec
Inc., Los Angeles California, March 6, 1971.
(20) EPA Research Contract No. 68-01-0099, "Development of
Modular Transportable Prototype System for Treating
Spilled Hazardous Materials," Hernord, Inc., Milwaukee,
Wisconsin, June 29, 1971.
351
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(21) EPA Research Contract No. 68-01-0077, "Process for
Housing and Community Development Industries," Levitt
and Son, Nassau County, New York, June 15, 1971.
(22) EPA Research Contract No. 68-01-0013, "Waste Heat
Utilization in Waste Water Treatment," URS Research
Company, San Mateo, California, December 31, 1970.
(23) EPA Research Contract No. 58-01-0901, "Study of
Improvements in Granular Carbon Adsorption Process,"
FMC Corporation, Princeton, New Jersey, June 26, 1970.
(24) EPA Advanced Waste Treatment Contract No. 58-01-0444,
"Carbon Adsorption and Electro dialipes for Demineralization
at Santee California," Santee County Water District,
Santee California, June 29, 1968.
(25) EPA Research Contract No. 58-01-0400, "Activated Carbon
Powder Treatment in Slurry Clarifiers," Infilco, Fullers
Company, Tucson, Arizona, June 9, 1968.
(26) EPA Research Contract No. 58-01-0075, "Study of Powdered
Carbons for Waste Water Treatment, "West Virginia Pulp
and Paper Company, Covington, Virginia, June 29, 1967.
(27) EPA Research Study No. 21ABK-31, "Treatability of Organic
Compounds," EPA NERC Cincinnati, Ohio, January 7, 1973.
(28) EPA Research Study No. 21 ABK 16, "Treatability of Organic
(29) EPA Research Study No. 21 ACP 09, "Removal of Toxi Metals
in Physical Chemical Pilot Plant," EPA NERC Cincinnati, Ohio
January 1, 1972.
(30) EPA Research Study No. 16 ACG-05, "Identify Pollutants
in Physical Chemical Treated Wastes," EPA NERC Corvallis,
Oregon, January 8, 1971.
(31) EPA Advanced Waste Treatment Demonstration Grant No. 800685,
"A Demonstration of Enhancement of Effluent from Trickling
Filter Plant," City of Richardson, Texas, December 24, 1971.
(32) EPA Advanced Waste Treatment Demonstration Grant No. 801026,
"Removal of Heavy Metals by Waste Water Treatment Processes,"
City of Dallas, Texas, January 2, 1972.
(33) EPA Advanced Waste Treatment Demonstration Grant No. 801401,
352
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"Piscataway Model advanced Waste Treatment Plant," Washington
Suburban Sanitary Commission, Hyattsville, Maryland, January
1, 1967.
(34) EPA Research Grant No. 800661, "Oxidation Mechanisms on
Supported Chromia Catalysts, "Purdue Research Foundation,
Lafayette, Indiana, January 6, 1970.
(35) EPA Research Grant No. 12130 DRO, "Deep Water Pilot Plant
Treatability Study," Delaware River Basin Commission,
Trenton, New Jersey, July, 1971.
353
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SECTION XVI
GLOSSARY
The terms defined here relate to common chemical conversions
utilized extensively in the organic chemicals industry.
Acylation Subeategory r A
The acylation reaction introduces an acyl group, RCO-, into an
aromatic ring. The product is an aryl ketone. The arylating
reagents commonly used are acid halides, ROCOCl, or anhydrides,
(RCO)20. The catlyst is aluminum chloride. The reaction is
usually carried out in an organic solvent, commonly carbon
disulfide or nitrobenzene.
Acylation is utilized in the manufacture of dye intermediates
such as acetanilide, and acetyl-p-toluidine. The reaction for
acetanilide is shown below:
AICU
C6H5NH2 + (CH3CO)20 -^ C,llrfJHCOCHo + CH.COOH
Catalyst J
Aniline Acetic Acetanilfde Acetic Acid
Anhydride
Although the reaction itself is nonaqueous (Subcategory A), water
may be used in the subsequent separation of the reaction
products. When carried out batchwise the reaction may fall
within the context of an overall Subcategory D system.
Alcoholvsis (Transesterification^ Subcategory C
Alcoholysis is the cleavage of an ester by an alcohol. It is
also called transesterification. The reaction is usually
catalyzed by aqueous sulfuric acid. A generalized equation for
the reactions is shown below:
H2SO,
RCOOR1 + R"OH ~± RCOOR" + R'OH
Transesterification is an equilibrium reaction. To shift the
equilibrium to the right it is necessary to use a large excess of
the alcohol whose ester is desired, or else remove one of the
products from the reaction mixture. The second approach is used
in most industrial applications, since in this way the reaction
can be driven to completion.
An excellent example of the application of transesterification is
found in the synthesis of the polymer, polyvinyl alcohol.
354
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H?SO,
-CH2CH- + CH3OH L *. CH3COOCH3 + -CH2CH-
0 Methanol flethyl OH
I Acetate
C = 0 Polyvinyl
Alcohol
Polyvlnyl
Acetate
Although there are hundreds of acetate groups in every modecule
of polyvinyl acetate, each of them undergoes the reactions
typical of any ester. In the presence of aqueous sulfuric acid,
polyvinyl acetate and methyl alcohol can exist in equilibrium
with methyl acetate and polyvinyl alcohol. The reaction mixture
is heated so that the lowest boiling compound, methyl acetate,
distills out and the reaction proceeds to completion.
Ammonoly.sis Subcategory^ C
The reaction is classified within Subcategory C as it is
conducted with an aqueous catalyst system.
Alkylation Subcategories_A^and_B
Alkylation refers to the addition of an aliphatic group to
another molecule. The media in which this reaction is
accomplished can be vapor or liquid phase, as well as aqueous or
nonaqueous.
Benzene is alkylated in the vapor phase over a solid catalyst
(silicaalumina impregnated with phosphoric acid) with propylene
to produce cumene.
C6H6 + C3H6 _> C6H5C3H7
Benzene Propylene Cumene
This reaction is nonaqueous and is considered within Subcategory
A.
Tetraethyl lead (the principal antiknock compound for gasolines)
is also a very important alkylated product. It is prepared by
the action of ethyl chloride on a lead-sodium alloy.
k PbNa + k C2H5C1 —»• Pb(C2H5)ll + 3 Pb + k NaCt
Alloy Ethyl Tetra Lead Sodium
Chloride Ethyl Chloride
Lead
355
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The reaction is carried out in an autoclave equipped with a
heating jacket, a stirrer to agitate the lead alloy, and a reflux
condenser. The mixture is heated at the start and then cooled
After 6 hours, the excess ethyl chloride is distilled off, and
the tetraethyl lead is steam stripped from the reaction mixture.
This type of staged batch reaction with direct contact steam is
considered typical of Subcategory D.
The alkylation reaction is also utilized in the manufacture of
dyestuffs and intermediates. Dimethylaniline is employed
intensively in the manufacture of triarylmethane dyes. It is
prepared according to the following reaction:
2 + 2 CH3OH W C6H5N(CH3>2 + 2 H20
Aniline Methanol Dimethylaniline Water
Aniline, with an excess of methanol and aqueous sulfuric acid, is
heated in an autoclave. The dealkylated product is discharged
through a cooling coil, neutralized, and vacuum distilled. This
is again typical of the chemical conversions with Subcategory D.
Amination, by Reduction Subcateqories_B^andmD
Amination by reduction involves the formation of an amino group
(-NH2) through the reduction of a nitro group (-NO2) . The
reaction can be carried out batchwise in an aqueous liquid phase
(Subcategory D) or continuously in the vapor phase (Subcategory
B) .
The reducing agents in the batch conversion are iron and an
aqueous acid catalyst (such as hydrochloric acid) . Aniline is
produced by the reaction as follows:
HCI
if C6H5N02 + 9 Fe + 4 H20 — * k CgHgNH., + 3
Nitrobenzene Iron Water Aniline IronOxfde
This batch reaction for reducing nitrobenzene with iron to
aniline is being replaced by the continuous vapor phase reduction
shown below:
C6HrN02 + 3 H2 — *• C6H5NH2 + 2 H2°
Nitrobenzene Hydrogen Aniline Water
The reaction is conducted with a very short contact time in a
tube packed with copper on SiO2 as the catalyst. The hydrogen is
adsorbed to the catalyst surface. Molecules of nitrobenzene are
next adsorbed on the hydrogenated surface. The reaction
products, aniline and water vapor, then desorb from the catalyst.
This type of vapor phase reaction is typical of Subcategory B.
356
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Subcatecrory C
Amination by ammonclysis relates to those reactions in which an
amino compound is formed using aqueous ammonia. Industrial
applications include the production of ethanolamines and
methylamines.
A mixture of mono-, dir, and triethanolamine is obtained when
ethylene oxide is bubbled through aqueous ammonia as shown by the
following equation:
fHOCH2CH2NH2 Monoethanolamine
n(CoH/.0) + NHo — *. < (HOCH2CH2)2NH D iethanolamine
Triethanolamine
H
Methylamines are formed similarly by the ammonolysis of methanol.
These continuous reactions are also considered within Subcategory
c.
Aroma tizat ion (Reforming) Subcategory A
Aromatization is the conversion of saturated cyclic compounds to
aromatic compounds. The reaction is illustrated by the following
equation:
Heat and
C6HnCH3 ^. C6H5CH3 + 3 H2
Catalyst
Methylcyclohexane Toluene Hydrogen
The reaction is carried out in the vapor phase with or without
catalysts. It is nonaqueous and considered within Subcategory A.
Condensation Subcategory D
Condensation reactions involve the closure of structural rings in
aromatic compounds. They are carried out batchwise in aqueous
acid solutions and are of great importance in the manufacture of
dye intermediates.
2js£y.^£££i°.£ Subcategories_B^andmC
Ethers are commonly produced by the dehydration of alcohols.
When carried out in the liquid phase using sulfuric acid as a
catalyst, the reaction is considered within Subcategory C.
However, it can also be accomplished in the vapor phase over
solid alumina catalysts within Subcategory B.
The following reaction for the production of ethyl ether from
ethanol can be accomplished by either route:
Ethanol Ethyl Ether Water
357
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Esterif ication gubcategorv C
Ssterif ication generally involves the combination of an alcohol
and an organic acid to produce an ester and water. The reaction
is carried out in the liquid phase with aqueous sulfuric acid as
the catalyst. The use of sulfuric acid has in the past caused
tnis type of reaction to be called sulfation. The equation for
aC6tate from acetic acid and ethanol is shown
CH3COOH — * C
Ethanol Acetic Acid Ethyl Acetate Water
Continuous ester if ication reactions are considered within
Subcategory C.
Friedel- Crafts Reactions Subcategorv A
Friedel-Crafts reactions involve the alkylation or acylation of
an aromatic ring in the presence of such catalysts as AICI3, BF3,
SnCIU, 12- These addition reactions are sensitive to trace
quantities of moisture and must be carried out under anhydrous
conditions.
Halogenation and Hydrohalogenation Subcategory^A
These reactions refer to the addition of a halogen (CI2, Br2f 12,
F2) to an organic irolecule. The various products are obtained
through both liquid and vapor phase reactions with or without
catalysts. Aliphatic compounds such as methane and ethane can
both be chlorinated in the vapor phase with the cocurrent
production of HCI gas.
CH3CH3 + CI2 — » CH3CH2CI + HCI
Ethane Chlorine Ethyl Hydrogen
Chloride Chloride
The by-product HCI can also be reacted with ethylene to form
ethyl chloride by hydrohalogenation. This later reaction is
carried out over an anhydrous aluminum chloride catalyst,
The addition of halogens to unsaturates (alkenes) serves to give
many other derivatives such as ethylene dichloride, ethylene
dibromide, dichloroethylene, trichloroethylene, and
tetrachloroethane. The preparation of ethylene dichloride is
typical:
C2H2Br2
C2H4 + CI2 .«*. C2H2CI2
Ethylene Chlorine Ethylene Dichloride
The chlorine gas is bubbled through a tank of liquid ethylene
dibromide (catalyst) , and the mixed vapors are sent to a
chlorinating tower where they meet a stream of ethylene. The
products from the tower pass through a partial condenser,
followed by a separator, with the crude ethylene dichloride
passing off as a gas and the liquid ethylene dibromide being
returned to the systems.
These reactions are all non-aqueous and are within Subcategory A.
However, it should be noted that some of these reactions may also
be carried out batchwise in dye manufacture and as such may fall
within the context of a Subcategory D system.
358
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Hydro formvlatipn __ (CXO Process) Subcategory C
The oxo process is a method of converting olefins to aldehydes
containing one additional carbon atom. The olefin is reacted in
the liquid phase with a mixture of hydrogen and carbon monoxide
in the presence of a soluble cobalt catalyst to produce the
aldehyde. A typical reaction follows, in which propylene is
converted to n- but yr aldehyde:
CO + H2
HCo(CO)i»
Propylene Carbon Hydrogen n-Butyraldehyde
Monoxide
The reaction itself is nonaqueous. However, the regeneration of
the cobalt carbonyl catalyst complex requires extensive usage of
aqueous solutions of sodium carbonate and sulfuric acid. This
aqueous catalyst regeneration causes the hydroformylation
reaction to be classified in Subcategory C.
^X.4£Q2£S^ioD_§n<^ Dehydrogenation Subcategor v B
The hydrogenation reaction involves the addition., while
dehydrogenation involves the removal of hydrogen from an organic
molecule. Both types of reaction are carried out in the vapor
phase, at elevated temperatures, over solid catalysts such as
platinum, palladium, nickel, copper, or iron oxides. Steam is
added in many cases as a diluent to reduce the partial pressure
of hydrocarbons in the reactor and prevent the formation of coke
on the catalyst. These reactions are considered within
Subcategory B.
Typical hydrogenation products include methanol produced from
carbon monoxide and hydrogen as well as other alcohols produced
from aldehydes. Dehydrogenation products include ketones, such
as acetone, produced from alcohols, such as isopropanol.
Hydration fHydrovlsis) Subcategories B and C
These reactions can be either liquid or vapor phase. Liquid
phase systems include the production of ethanol from ethylene
with aqueous sulfuric acid or isopropanol from propylene. The
corresponsing vapor phase routes are carried out over solid H^PO.4
catalysts. The equation shown for ethanol can be done either
way:
C2H4 + H,0 — * C2H5OH
Ethylene Water Ethanol
Ethylene glycol and ethylene oxide can also be produced by either
a liquid or vapor phase route. The liquid reaction involves the
359
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formation of ethylene chlorohydrin, which is produced by the
reaction of aqueous chlorine with ethylene.
CH2CH2
Ethylene
CI2 + H20—•*• CH2OH-CH2CI + HCI
Chlorine Water Ethylene Hydrogen
Chlorohydrin Chloride
The ethylene chlorohydrin is treated with aqueous sodium
bicarbonate solution to produce ehtylene glycol.
CH2OH-CH2CI
Ethylene
Chlorohydrin
NaHCOj
Sod Iurn
Bicarbonate
CH2OH-CH2OH
Ethylene
Glycol
NaCI
Sod I um
Chloride
C02
Carbon
Dioxide
More recently the chlorohydrin route to ethylene oxide and glycol
has been replaced by the reaction of ethylene with oxygen and
water:
Ethylene
1/2 02 —*• C2H/,0
Oxygen Ethylene Oxide
C2H!fO
Ethylene
Oxide
H20
Water
CH2OH-CH2OH
Ethylene Glycol
Ethylene and oxygen are charged to a tubular reactor which is
filled with silver catalyst (vapor phase) or sulfuric acid
(liquid phase). Ethylene oxide is recovered from the gaseous
reactor effluent by absorption in water. The wet ethylene oxide
is then reacted with water in the presence of sulfuric acid to
produce ethylene glycol.
Depending on whether these reactions are aqueous liquid phase or
vapor phase they may be considered in either Subcategory B or C.
Neutralization
Subcategory C
The treatment of reactor effluents with either caustic or acid is
a necessary part of many reaction systems. The neutralizing
reagents normally used are sulfuric acid or sodium hydroxide.
Gaseous effluents are normally treated in an absorber while
360
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liquid effluents are treated in a liquid- liquid contactor. Both
types of treatment are considered within Subcategory C.
Nitration SujbcategorJ.es C and p
This reaction involves the introduction of nitrogen onto a
hydrocarbon by the use of nitric acid. It is usually carried out
in the liquid phase and may be either continuous or batch.
Nitrobenzene is produced as a dye intermediate by the direct
nitration of benzene, using a mixture of nitric and sulfuric
acids according to the following equation:
C6H6 f HMO + H2S04 -» C6H5N02 + HjSO* + H.0
.,
Benzene Nitric Sulfuric Nitrobenzene Sulfuric Water
Acid Acid Ac?£)
This type of reaction is considered either in Subcategory C or D.
Oxidation Subcat egor i es B and^C
This family of reactions may be carried out either in aqueous
solutions or in the vapor phase. The oxidant may be either air
or oxygen.
The liquid phase systems all utilize dissolved mineral salts such
as cobalt acetate. A typical reaction is the oxidation of
acetaldehyde to give acetic acid in an aqueous mixture of cobalt
acetate and acetic acid.
CH3CHO + 1/2 02 -* CH3COOH
Acetaldehyde Oxygen Acetic Acid
Alternatively, acetadehyde can be produced by the vapor phase
oxidation of ethancl over a silver gauze catalyst.
C2H5OH + 1/2 Q2 —». H CHO +
Ethanol Oxyqen Acetaldehyde Water
Depending on whether the reaction is vapor or liquid phase it may
be considered within Subcategory B or C.
Pyrolysis (Cracking^ Subcategory B
These reactions involve the breaking of carbon chains in alkanes
with the subsequent formation of alkanes and alkenes of lower
molecular weight. The equation below illustrates the cracking
reaction by which ethylene is produced:
361
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The reactions are all carried out in the vapor phase at very high
temperature. Steam is usually added as a diluent to prevent the
formation of coke. For this reason, the reactions are considered
within Subcategory B.
CH3CH2CH3 —» CH2CH2 +
Propylene Ethylene Methane
362
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METRIC UNITS
CONVERSION TABLE
MULTIPLY (ENGLISH UNITS)
ENGLISH UNIT ABBREVIATION
acre ac
acre - feet ac ft
British Thermal
Unit BTU
British Thermal BTU/lb
Unit/pound
cubic feet/minute cfn
cubic feet/second cfs
cubic feet cu ft
cubic feet cu ft
cubic inches cu in
degree Fahrenheit °F
feet ft
gallon gal
gallon/rainute gpm
horsepower hp
inches in
inches of mercury in Hg
pounds Ib
Million gallons/day mgd
mile mi
pound/square inch psig
(gauge)
square feet sq ft
square inches sq in
tons (short) ton
yard yd
by TO OBTAIN (METRIC UNITS)
CONVERSION ABBREVIATION METRIC UNIT
hectares
cubic meters
kilogram, -calories
kilogran calories/
kilogram
cubic meters/minuts
cubic in e t e r s / m i n u t;
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
liters/second
killowatts
centimeters
atmospheres
kilograms
cubic meters/day
kilometer
atmospheres
(absolute)
square meters
square centimeters
metric tons
(1000 kilograms)
meters
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555(°
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
ha
cu m
kg cal
kg cal/kg
cu m/min
cu n/min
cu m
1
cu cm
F-32)* °C
m
1
I/sec
kw
cm
atm
kg
cu m/day
km
(0.06805 psig +l)*atm
0.0929
6.452
0.907
sq m
sq cm
kkg
0.9144
* Actual conversion, not a multiplier
363
AU.S. GOVERNMENT PRINTING OFFICE:1974 546-318/339 1-3
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