EPA-453/R-94-064a
VOC Emissions from SOCMI Wastewater-
Background Information for
Proposed Standards
Emission Standards Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park North Carolina 27711
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August 1994
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(Disclaimer)
This Report has been reviewed by the Emission Standards Division
of the Office of Air Quality Planning and Standards, EPA, and
approved for publication. Mention of trade names or commercial
products is not intended to constitute endorsement or
recommendation for use. Copies of this report are available
through the Library Services Office (MD-35), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711, or from the
National Technical Information Service, 5285 Port Royal Road,
Springfield, VA 22161.
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ENVIRONMENTAL PROTECTION AGENCY
Background Information for Proposed Standards
VOC Emissions From SOCMI Wastewater
Prepared by:
Bruce Jordan (Date)
Director, Emission Standards Division
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
1. The proposed standards would regulate emissions of volatile
organic compounds (VOC) emitted from wastewater generated by
Synthetic Organic Chemical Manufacturing Industry (SOCMI)
process units and are limited to emission points in the
associated process unit's wastewater collection and
treatment systems. These standards implement section 111 of
the Clean Air Act based on the administrator's determination
that VOC emissions from SOCMI cause, or contribute
significantly to, air pollution that may reasonably be
anticipated to endanger public health or welfare.
2. Copies of this document have been sent to the following
Federal Departments: Labor, Health and Human Services,
Defense, Office of Management and Budget, Transportation,
Agriculture, Commerce, Interior, and Energy; the National
Science Foundation; and the Council on Environmental
Quality. Copies have also been sent to members of the State
and Territorial Air Pollution Program Administrators; the
Association of Local Air Pollution Control Officials; EPA
Regional Administrators; and other interested parties.
3. The comment period for this document is 90 days from the
date of publication of the proposed standards in the Federal
Register. Ms. JoLynn Collins may be contacted at
919-541-5671 regarding the date of the comment period.
4. For additional information contact:
Mr. Robert Lucas
Chemicals and Petroleum Branch (MD-13)
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Telephone: 919-541-0884
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Copies of this document may be obtained from:
U.S. EPA Library (MD-35)
Research Triangle Park, NC 27711
Telephone: 919-541-2777
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
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TABLE OF CONTENTS
1.0 INTRODUCTION 1-1
1.1 BACKGROUND AND AUTHORITY OF STANDARDS 1-1
1.2 SELECTION OF STATIONARY SOURCES 1-3
1.3 PROCEDURE FOR DEVELOPMENT OF STANDARDS OF
PERFORMANCE 1-3
1.4 COST CONSIDERATIONS 1-5
1.5 ENVIRONMENTAL IMPACTS 1-5
1.6 IMPACT ON EXISTING SOURCES 1-6
2.0 INDUSTRY DESCRIPTION 2-1
2.1 DESCRIPTION OF SOCMI 2-1
2.2 CHARACTERIZATION OF THE INDUSTRY 2-2
2.3 REFERENCES 2-2
3.0 PROCESS DESCRIPTION AND EMISSION POINTS 3-1
3.1 SOURCES OF ORGANIC COMPOUND-CONTAINING WASTEWATER . 3-1
3.1.1 Direct Contact Wastewater 3-1
3.1.2 Indirect Contact Wastewater 3-2
SOURCES OF AIR EMISSIONS 3-2
3.2.1 Drains 3-3
3.2.2 Manholes 3-3
3.2.3 Junction Boxes 3-3
3.2.4 Lift Stations 3-3
3.2.5 Trenches 3-4
3.2.6 Sumps 3-5
3.2.7 Weirs 3-5
3.2.8 Oil/Water Separators 3-5
3.2.9 Equalization Basins 3-5
3.2.10 Clarifiers 3-6
3.2.11 Aeration Basins 3-6
3.2.12 Treatment Tanks 3-7
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3.2.13 Surface Impoundments 3-7
3.3 REFERENCES 3-7
VI
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4.0 CONTROL TECHNOLOGY AND PERFORMANCE OF CONTROLS 4-1
4.1 WASTE MINIMIZATION 4-1
4.2 SUPPRESSION AND TREATMENT TECHNOLOGIES 4-2
4.2.1 Organic Compound Treatment Technologies . . 4-2
4.2.1.1 Steam Stripping 4-2
4.2.1.2 Air Stripping 4-3
4.2.3 Biological Treatment Technology 4-4
4.2.4 Other Organic Compound Removal
Technologies 4-4
4.3 EMISSIONS SUPPRESSION 4-4
4.4 ADD-ON CONTROLS 4-5
4.4.1 Carbon Adsorbers 4-6
4.4.2 Thermal Vapor Incinerators 4-7
4.4.3 Combination Adsorption-Incineration .... 4-7
4.4.4 Catalytic Vapor Incinerators 4-8
4.4.5 Flares 4-8
4.4.6 Boilers and Process Heaters 4-8
4.4.7 Condensers 4-9
4.5 REFERENCES 4-9
5. MODIFICATION AND RECONSTRUCTION 5-1
5.1 SELECTION OF AFFECTED FACILITY 5-1
5.2 MODIFICATION 5-2
5.2.1 Feedstock, Catalyst, or Reactant
Substitution 5-4
5.2.2 Process Equipment 5-5
5.2.3 Combination of Changes 5-5
5.3 RECONSTRUCTION 5-5
5.4 REFERENCES 5-6
6.0 METHODOLOGY FOR ESTIMATING BASELINE AND CONTROLLED
ORGANIC EMISSIONS 6-1
6.1 BASELINE CHARACTERIZATIONS 6-1
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6.2 BASELINE AND CONTROLLED EMISSIONS ESTIMATES .... 6-2
6.3 REFERENCES 6-5
7.0 NATIONWIDE ENVIRONMENTAL AND ENERGY IMPACTS 7-1
7.1 BASIS FOR IMPACTS ESTIMATION 7-1
7.2 ESTIMATION OF CONTROLLED EMISSIONS 7-2
7.3 ESTIMATION OF NSPS IMPACTS 7-3
7.3.1 Approach to Impacts Estimation 7-3
7.3.2 Results of Impacts Estimation 7-4
7.3.2.1 Incremental Approach Based on HON
Impacts 7-4
7.3.2.2 Wastewater Flow Rate Approach . . . 7-7
7.3.2.3 Combined Results 7-10
7.4 OTHER ENVIRONMENTAL AND ENERGY IMPACTS 7-11
7.4.1 Secondary Air Pollution Impacts 7-12
7.4.2 Other Impacts 7-12
7.4.2.1 Water Pollution Impacts 7-12
7.4.2.2 Solid and Hazardous Waste Impacts . 7-12
7.4.2.3 Energy Impacts 7-13
7.4.3 Impacts Estimates 7-13
7.5 REFERENCES 7-14
ENHANCED MONITORING 8-1
8.1 ENHANCED MONITORING FOR CONTROL DEVICES 8-1
8.2 MONITORING OF WASTEWATER TREATMENT DEVICES .... 8-3
8.3 ENHANCED MONITORING OF TANKS 8-3
8.4 ENHANCED MONITORING OF CONTAINERS 8-4
8.5 ENHANCED MONITORING OF CLOSED VENT SYSTEMS .... 8-4
8.6 REFERENCES 8-5
9.0 CONTROL COST ESTIMATES 9-1
9.1 STEAM STRIPPER DESIGN 9-1
9.1.1 Feed Tank 9-2
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9.1.2 Steam Stripper 9-2
9.1.3 Emissions Control 9-2
9.1.4 Product Recovery 9-3
9.1.5 Stripper Efficiency 9-3
9.1.6 Applicability 9-3
9.2 STEAM STRIPPER COSTS 9-4
9.2.1 Design Considerations 9-4
9.2.2 Capital Costs 9-4
9.2.3 Annual Costs 9-5
9.4 REFERENCES 9-5
Appendix A List of SOCMI Chemicals A-l
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List of Tables
3-1 Emission Sources in Wastewater Collection and Treatment
Systems 3-4
4-1 Emission Suppression Controls for Wastewater Collection
System Components 4-6
7-1 NSPS Regulatory Alternatives 7-4
7-2 Emission Reductions and Costs for HON and NSPS 7-6
7-3 Nationwide Impacts of NSPS Options 7-6
7-4 Emission Reductions and Costs for NSPS Alternatives in the
Fifth Year After Promulgation 7-8
7-5 Nationwide Impacts of NSPS Options in the Fifth Year After
Promulgation 7-8
7-6 Estimated NSPS Impacts Based on Averaging 7-11
7-7 Total Capital Costs Based on Averaging of Two Methods 7-11
7-8 Other Environmental and Energy Impacts in teh Fifth Year
After Promulgation 7-14
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1.0 INTRODUCTION
1.1 BACKGROUND AND AUTHORITY OF STANDARDS
Standards of performance for new stationary sources are
established under Section 111 of the Clean Air Act (42 U.S.C.
7411), as amended, herein referred to as the Act. Section 111
directs the Administrator to establish standards of performance
for any category of new stationary source of air pollution that
"causes, or contributes significantly to air pollution which may
reasonably by anticipated to endanger public health or welfare."
The Act requires that standards of performance for
stationary sources reflect "the degree of emission reduction
achievable which (taking into consideration the cost of achieving
such emission reduction, and any nonair quality health and
environmental impact and energy requirements) the Administrator
determines has been adequately demonstrated for that category of
sources." The standards apply only to stationary sources, the
construction or modification of which commences after regulations
are proposed by publication in the Federal Register.
Standards of performance, by themselves, do not guarantee
protection of health or welfare because they are not designed to
achieve any specific air quality levels. Rather, they are
designed to reflect the degree of emission limitation achievable
through application of the best adequately demonstrated
technological system of continuous emission reduction, with the
cost of achieving such emission reduction, any nonair quality
health and environmental impacts, and energy requirements being
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considered.
Promulgation of standards of performance does not prevent
State or local agencies from adopting more stringent emission
limitations for the same sources. States are free under Section
116 of the Act to establish even more stringent emission limits
than those established under Section 111 or those necessary to
attain or maintain the National Ambient Air Quality Standards
(NAAQS) under Section 110. Thus, new sources may in some cases
be subject to limitations more stringent than standards of
performance under Section 111.
Although standards of performance are normally structured in
terms of numerical emission limits, where feasible, alternative
approaches are sometimes necessary. In some cases physical
measurement of emissions from a new source may be impractical or
exorbitantly expensive. Section 111(h) provides that the
Administrator may promulgate a design or equipment standard in
cases where it is not feasible to prescribe or enforce a standard
of performance. For example, emissions of hydrocarbons from
storage vessels for petroleum liquids are greatest during tank
filling. The nature of the emissions--high concentrations for
short periods during filling and low concentrations for longer
periods during storage—and the configuration of storage tanks
make direct emission measurement impractical. Therefore,
equipment specification has been a more practical approach to
standards of performance for storage vessels.
In addition, Section lll(j) authorizes the Administrator to
grant waivers of compliance to permit a source to use innovative
continuous emission control technology. In order to grant the
waiver, the Administrator must find that the technology meets a
specific set of conditions. Waivers may have conditions attached
to assure that use of the innovative technology will not prevent
attainment of any NAAQS. Any such condition will have the force
of a performance standard. Finally, waivers have definite end
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dates and may be terminated earlier if the conditions are not met
or if the system fails to perform as expected. In such a case,
the source may be given up to 3 years to meet the standards with
a mandatory progress schedule.
1.2 SELECTION OF STATIONARY SOURCES
The Clean Air Act amendments of August 1977 establish
specific criteria to be used in determining priorities for
regulating source categories. These are (1) the quantity of air
pollutant emissions that each such category will emit, or will be
designed to emit; (2) the extent to which each such pollutant may
reasonably be anticipated to endanger public health or welfare;
and (3) the mobility and competitive nature of each such category
of sources and the consequent need for nationally applicable new
source standards of performance.
After the source category has been chosen, the types of
facilities within the source category to which the standard will
apply must be determined. A source category may have several
facilities that cause air pollution, and emissions from some of
these facilities may vary from insignificant to very expensive to
control. Economic studies of the source category and of
applicable control technology may show that air pollution control
is better served by applying standards only to the more severe
pollution sources. For this reason, and because there is no
adequately demonstrated system for controlling emissions from
some types of facilities, standards often do not apply to all
facilities at a source. For the same reasons, the standards may
not apply to all air pollutants emitted. Thus, although a source
category may be selected to be covered by a standard of
performance, not all pollutants or facilities within that source
category may be covered by the standards.
1.3 PROCEDURE FOR DEVELOPMENT OF STANDARDS OF PERFORMANCE
Standards of performance must (1) realistically reflect best
demonstrated control practice; (2) adequately consider the cost,
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the nonair quality health and environmental impacts, and the
energy requirements of such control; (3) be applicable to
existing sources that are modified or reconstructed, as well as
new installations; and (4) meet these conditions for all
variations of operating conditions being considered anywhere in
the country. The objective of a program for developing standards
is to identify the best technological system of continuous
emission reduction that has been adequately demonstrated.
As a part of the studies, hypothetical "model plants" are
defined to provide a common basis for analysis. The model plant
definitions, national pollutant emission data, and existing State
regulations governing emissions from the source category are then
used in establishing "regulatory alternatives." These regulatory
alternatives are essentially different levels of emission control
applicable to the source.
The EPA conducts studies to determine the impact of each
regulatory alternative on the economics of the industry and on
the national economy, on the environment, and on energy
consumption. From several possibly applicable alternatives, the
EPA selects the single most plausible regulatory alternative as
the basis for a standard of performance for the source category
under study. In the final phase of a project, the selected
regulatory alternative is translated into a standard of
performance, which, in turn, is written in the form of a Federal
regulation. The Federal regulation, when applied to newly
constructed plants, will limit emissions to the levels indicated
in the selected regulatory alternative. The information acquired
in the project is summarized in the Background Information
Document (BID).
A "proposal package" is assembled and sent through the
offices of EPA Assistant Administrators for concurrence before
the proposed standard is officially endorsed by the EPA
Administrator. After being approved by the EPA Administrator,
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the preamble and the proposed regulation are published in the
Federal Register.
As a part of the Federal Register announcement of the
proposed regulation, the public is invited to participate in the
standard-setting process. The EPA invites written comments on
the proposal and also holds a public hearing to discuss the
proposed standards with interested parties. All public comments
are summarized and incorporated into a second volume of the Bid.
All information reviewed and generated in studies in support of
the standard of performance is available to the public in a
"docket" on file in Washington, DC.
Comments from the public are evaluated, and the standard of
performance may be altered in response to the comments. The
significant comments and the EPA's position on the issues raised
are included in the "preamble" of a "promulgation package," which
also contains the draft of the final regulation. The regulation
is then subjected to another round of review and refinement until
it is approved by the EPA Administrator. After the Administrator
signs the regulation, it is published as a "final rule" in the
Federal Register.
1.4 COST CONSIDERATIONS
Section 317 of the Act requires an economic impact
assessment of any standard of performance established under
Section 111. That assessment must include analyses of the costs
of compliance, potential inflationary or recessionary effects,
small business impacts, effects on consumer costs, and effects on
energy usage. The analysis should include any costs associated
with environmental effects of a regulation. For example,
captured potential air pollutants may pose a solid waste disposal
problem.
1.5 ENVIRONMENTAL IMPACTS
The EPA routinely prepares estimates of environmental
impacts for regulatory actions under Section 111 of the Act.
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This analysis is devoted to assessing potential environmental
impacts of a standard and addresses both adverse and beneficial
impacts. These impacts could occur in such areas as air and
water pollution, increased solid waste disposal, and increased
energy consumption. Estimates of the impacts of the NSPS are
presented in a separate chapter of this Background Information
Document.
1.6 IMPACT ON EXISTING SOURCES
Standards of performance under Section 111 of the Act apply
to "new sources" which are defined as "any stationary source, the
construction or modification of which is commenced" after the
proposed standards are published. An existing source is
redefined as a new source if "modified" or "reconstructed" as
defined in the general provisions of Subpart A of 40 CFR Part 60.
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2.0 INDUSTRY DESCRIPTION
The purpose of this chapter is to briefly describe and
characterize the Synthetic Organic Chemical Manufacturing
Industry (SOCMI). The chapter also discusses chemical production
processes (CPP's) that are considered a part of SOCMI and
describes waste and wastewater generation and handling. The
discussion presented here is a summary of information in the
Background Information Document for the Hazardous Organic NESHAP
(HON) l and the reader is referred to that document for a more
detailed discussion.
2.1 DESCRIPTION OF SOCMI
The SOCMI is one segment of the entire chemical industry and
can be represented as an expanding system of production stages
producing a multitude of organic chemicals from 11 basic
chemicals. The first stage of the chemical industry which
supplies the 11 basic chemicals includes refineries, natural gas
plants, and coal tar distillation plants. The SOCMI consists of
the remaining stages of this expanding production system. Within
the SOCMI, the 11 basic chemicals are processed through one or
more CPP's to produce intermediate and finished chemicals.
Within the SOCMi, there are often multiple means of
manufacturing a given chemical. For example, the production of
allyl alcohol is possible using three different raw materials.
Also, an entire family of chemicals can often be produced
sequentially from one chemical. Generally, there is a shift from
high-volume production of SOCMI intermediates at the front end of
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the chemical family to low-volume production of finished
chemicals (e.g., ethyl acrylate) at the farthest end of the
chemical family. All of these production processes, regardless
of capacity, are considered a part of SOCMI if they generate
wastewater and would be subject to regulation under the NSPS for
wastewater.
Organic chemicals are produced at a wide range of
facilities, from large facilities manufacturing a few chemicals
in large volumes, to smaller facilities manufacturing many
different finished chemicals in smaller volumes. Facilities
producing chemicals at the end of a chemical family are usually
smaller operations that produce a variety of closely-related
finished chemicals.
The products of the SOCMI are used in many different
industrial markets. Many SOCMI chemicals serve as the raw
materials for deriving non-SOCMI products such as plastics,
synthetic rubbers, fibers, protective coatings, and detergents.
Few SOCMI chemicals have direct consumer uses. The impacts
analysis for this project considers only the production of SOCMI
chemicals and does not cover the production of non-SOCMI
products.
The SOCMI can be characterized geographically by identifying
those states that should be analyzed to determine current levels
of control and to establish baseline control requirements. A
large percentage of the total number of process units in the
SOCMI are found in only a few states, with Texas and Louisiana
having the greatest number. Specifically, more than 70 percent
of the SOCMI process units are located in only nine states.
Forty of the 50 States have SOCMI process units, and 18 of the
40 States have less than 1 percent of the national total number
of process units. Thus, it was not necessary to analyze all
States for baseline control requirements.
2.2 CHARACTERIZATION OF THE INDUSTRY
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In previous standards-setting programs, the EPA has
characterized the SOCMI as a group of process units manufacturing
or processing one or more chemicals included in a specific list.
This approach has also been used for the NSPS analysis. There
are a total of 735 chemical manufacturing processes subject to
the proposed regulation. To make the scope of the NSPS as broad
as possible, the list of chemicals proposed to be regulated under
this rule is a composite list derived from several sources.
These sources include: (1) "Industrial Organic Chemical Use
Trees," EPA/ORD, October 1992; (2) Standards of Performance for
Equipment Leaks of VOC in SOCMI, 40 CFR Part 60, Subpart W; (3)
Proposed Standards of Performance for SOCMI Reactor Processes,
55 FR 26953, June 29, 1990; (4) Standards of Performance for
SOCMI Distillation Operations, 40 CFR Part 60, Subpart NNN; and
(5) Standards of Performance for SOCMI Air Oxidation Processes,
40 CFR Part 60, Subpart III. The chemicals are listed in
Appendix A of this document.
The SOCMI can be characterized in terms of production
capacity and production rate where the difference between the two
is capacity utilization. Without complete information for
capacity utilization, capacity can be used as an indicator of
rate. This information is important because emissions generally
are closely tied to production rate. The characterization found
that production capacities for process units range from less than
20 Gg/yr (22 million tpy) to greater than 600 Gg/yr (660 million
tpy). The complete range of production volumes is included in
the impacts evaluation.
2.3 REFERENCES
1. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Hazardous Air Pollutant Emissions
From Process Units in the Synthetic Organic Chemical
Manufacturing Industry—Background Information for Proposed
Standards Volume 1A. Research Triangle Park, NC. November
1992. Chapter 3.
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3.0 PROCESS DESCRIPTION AND EMISSION POINTS
Individual facilities within the SOCMI generate wastewater
streams that contain organic compounds. These wastewaters are
collected and treated in a variety of ways, some of which result
in the emission of volatile organic compounds (VOC's) from the
wastewater to the air. This chapter provides a discussion of
potential VOC emissions from wastewater sources. Information in
this chapter is primarily a summary of information contained in
the Industrial Wastewater CTG1 and the reader is referred to that
document for a fuller discussion.
3.1 Sources of organic compound-containing wastewater
Organic compound-containing wastewater streams are generated
by direct contact of water with organic compounds and by
contamination of indirect contact wastewater through equipment
leaks in chemical processing. Each of these two mechanisms are
briefly described below.
3.1.1 Direct contact wastewater. Water may come into direct
contact with organic compounds during a variety of different
chemical processing steps, thus generating wastewater streams
that must be discharged for treatment or disposal. Direct
contact wastewater includes:
! Water used to wash impurities from organic compound
products or reactants;
! Water used to cool or quench organic compound vapor
streams;
! Condensed steam from jet eductor systems pulling vacuum
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on vessels containing organic compounds;
! Water from raw material and product storage tanks;
! Water used as a carrier for catalysts and neutralizing
agents (e.g., caustic solutions); and
! Water formed as a byproduct during reaction steps.
Direct contact wastewater is also generated when water is
used in equipment washes and spill cleanups. This wastewater is
normally more variable in flow rate and concentration than the
streams listed above and may be collected in a way that is
different from process wastewater.
3.1.2 Indirect contact wastewater. Wastewater streams generated
by unintentional contact with organic compounds through equipment
leaks are defined as "indirect contact" wastewater. Indirect
contact wastewater may become contaminated as a result of leaks
from heat exchangers, condensers, and pumps. These indirect
contact wastewaters may be collected and treated differently from
direct contact wastewaters. Pump seal water is often collected
in area drains that tie into the process wastewater collection
system. This wastewater is then combined with direct contact
wastewater and transported to the wastewater treatment plant.
Wastewater contaminated from heat exchanger leaks is often
collected in different systems and may bypass some of the
treatment steps used in the treatment plant.
3.2 Sources of air emissions
Wastewater streams are collected and treated in a variety of
ways. Generally, wastewater passes through a series of
collection and treatment units before being discharged from a
facility. Many of these collection and treatment system units
are open to the atmosphere and allow organic compound-containing
wastewaters to contact ambient air, thus creating a potential for
VOC emissions. The magnitude of VOC emissions is somewhat
dependent on factors such as the physical properties of the
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Table 3-1. EMISSION SOURCES IN WASTEWATER COLLECTION
AND TREATMENT SYSTEMS
Drains
Manholes
Junction boxes
Lift stations
Trenches
Sumps
Weirs
Oil/water separators
Equalization or neutralization basins
Clarifiers
Aeration basins
Treatment tanks
Surface impoundments
pollutants, the temperature of the wastewater, and the design of
the individual collection and treatment units. Climatic factors
such as ambient temperature and wind speed and direction also
affect VOC emissions at many wastewater collection and treatment
units.
Collection and treatment schemes for wastewater are facility
specific. The flow rate and organic compound composition of
wastewater streams at a particular facility are functions of the
processes used and influence the sizes and types of collection
and treatment units needed. Table 3-1 lists potential sources of
emissions in facility collection and treatment systems. The
following sections briefly discuss each of these emission
sources.
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3.2.1 Drains. Waste streams from various sources throughout a
given process are introduced into the collection system through
process drains. Individual drains usually connect directly to
the main process sewer line, but may drain to trenches, sumps, or
ditches. Drains may be dedicated to a single piece of equipment
or may serve several sources. Many drains are open to the
atmosphere.
3.2.2 Manholes. Manholes provide access into process sewer
lines for inspection and cleaning activities. They are normally
placed at periodic distances along a sewer line and frequently
occur where sewers intersect or change significantly in
direction, grade, or sewer line diameter. Typically, manholes
are covered with a heavy cast-iron plate that contains two or
more holes.
3.2.3 Junction boxes. A junction box combines multiple
wastewater streams into a single stream. Generally, the flow
rate from the junction box is controlled by the liquid level
within the junction box. Junction boxes are typically open, but
may, for safety reasons, be closed and vented to the atmosphere.
3.2.4 Lift stations. Lift stations accept wastewater from one
or more sewer lines and are usually the last collection unit
before the treatment system. Lift stations collect and transport
wastewater to the treatment system. Pumps designed to turn on
and off in response to preset high and low liquid levels provide
the necessary head pressure for wastewater transport. Lift
stations are typically either open or closed and vented to the
atmosphere.
3.2.5 Trenches. Trenches are used to transport wastewater from
the point of discharge from a process to wastewater collection
units such as junction boxes and lift stations. In older plants,
trenches are often the primary mode of wastewater transportation
in the collection system. Trenches are often interconnected
throughout a process area and handle equipment pad water runoff,
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water from equipment wash downs and spill cleanups, and process
wastewater discharges. Trenches are typically open or covered
with grates.
3.2.6 Sumps. Sumps are used to collect and equalize wastewater
flow from trenches before treatment. They are usually quiescent
and open to the atmosphere. Sump size depends on the total flow
rate of the incoming wastewater stream(s).
3.2.7 Weirs. Weirs act as dams in open channels. The weir face
is usually aligned perpendicular to the bed and walls of a
channel. Water from the channel may overflow the weir or may
pass through a notch, or opening, in the weir face. Because of
their configuration, weirs provide some control over the level
and flow rate through the channel. Weirs may also be used for
wastewater flow rate measurement.
Water overflowing a weir may proceed down stair steps that
serve to aerate the wastewater thus increasing diffusion of
oxygen into the wastewater. The increased oxygen may improve
biodegradation processes which often follow weirs. However, this
increased contact with air also accelerates the volatilization of
organic compounds contained in the wastewater.
3.2.8 Oil/water separators. An Oil/water separator is often the
first step in wastewater treatment, although they are also found
in process areas. These units provide gravity separation and
removal of oils, scum, and solids from the wastewater. Most
separation occurs as the wastewater passes through a quiescent
zone in the unit. Oils and scum with specific gravities less
than water float to the top of the aqueous phase while heavier
solids sink to the bottom. Some organic compounds in the
wastewater partition into the oil phase and can be removed with
the skimmed oil leaving the separator.
3.2.9 Equalization basins. Equalization basins are used to
reduce fluctuations in wastewater temperature, flow rate, and
organic compound concentrations. Equalization of wastewater flow
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rate results in more uniform effluent quality from downstream
units and can benefit biological treatment performance by damping
fluctuations of influent organic concentration and flow rate.
This damping protects biological processes from upset or failure
due to shock loadings of toxic or treatment-inhibiting compounds.
Equalization basins normally use hydraulic retention time to
ensure equalization of the wastewater effluent leaving the basin.
However, some basins are equipped with mixers or surface aerators
to enhance the equalization, accelerate wastewater cooling, or
saturate the wastewater with oxygen before secondary treatment.
Equalization basins are almost always open to the atmosphere. In
some more recent wastewater collection and treatment systems,
tanks, rather than basins, are used for equalization.
3.2.10 Clarifiers. The primary purpose of a clarifier is to
separate solids from the wastewater through gravitational
settling. Most clarifiers are equipped with surface skimmers to
clear the water of floating oil deposits, grease, and scum.
Clarifiers also have sludge raking arms that remove any
accumulation of organic solids collected at the bottom of the
tank. Clarifiers are designed to provide sufficient retention
time for the settling and thickening of these solids.
3.2.11 Aeration basins. Biological waste treatment is normally
accomplished through the use of aeration basins. Microorganisms
require oxygen to carry out the biodegradation of organic
compounds, which results in energy and biomass production. The
aerobic environment in the basin is normally achieved with
diffused air or by mechanical aeration. This aeration also
serves to maintain the biomass in a well mixed regime. The
performance of aeration basins is particularly affected by: (1)
mass of organic compound per unit area of wastewater; (2) ambient
temperature and wind patterns; (3) hydraulic retention time; (4)
dispersion and mixing characteristics; (5) availability of
sunlight energy; and (6) availability of essential microbial
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nutrients.
Three mechanisms affect organic compound removal in aeration
basins: biodegradation, adsorption onto the sludge, and air
emissions. Because these three mechanisms compete against each
other, factors affecting biodegradation and adsorption mechanisms
will also have an effect on air emissions.
Typically, aeration basins are equipped with aerators to
introduce oxygen into the wastewater. The biomass uses this
oxygen in the process of biodegrading organic compounds.
However, aeration of wastewater also increases air emissions.
Some plants have replaced open aeration basins with aerated tanks
to reduce VOC emissions to the atmosphere.
3.2.12 Treatment tanks. Several different types of treatment
tanks may be used in wastewater treatment systems. Tanks
designed for pH adjustment typically precede the biological
treatment step. In these tanks, the wastewater pH is adjusted,
using acidic or alkaline additives, to prevent shocking the
biological system downstream. Flocculation tanks are typically
used to treat wastewater after biological treatment.
Flocculating agents are added to the wastewater to promote
formation or agglomeration of larger particle masses from the
fine solids formed during biological treatment. In the
clarifier, which usually follows the flocculation tanks in the
system, these larger particles precipitate more readily out of
the wastewater.
3.2.13 Surface impoundments. Surface impoundments are used for
evaporation, polishing, storage before further treatment or
disposal, equalization, leachate collection, and as emergency
surge basins. They may be quiescent or mechanically agitated.
3.3 References
1 U.S. Environmental Protection AGency, Office of Air Quality
Planning and Standards. Guideline Series Control of
Volatile Organic Compound Emissions from Industrial
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Wastewater. Research Triangle park, NC. Draft. September
1992. Chapter 3.
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4.0 CONTROL TECHNOLOGY AND PERFORMANCE OF CONTROLS
There are two fundamentally different approaches to
controlling VOC emissions from SOCMI wastewater sources. The
first is a source reduction or waste minimization approach in
which there is a reduction in the quantity of wastewater
generated and/or a reduction in the VO content of the wastewater
as a result of process modifications, modifications of operating
practices, improved preventative maintenance activities,
increased recycling, or segregation of VO containing waste
streams. The second approach involves emission suppression and
treatment of wastewater streams to remove organic compounds. The
following paragraphs present a brief discussion of these two
approaches. The discussions are derived primarily from
information presented in the Industrial Wastewater CTG1 and the
reader is referred to that document for further details of the
two approaches.
4.1 Waste minimization
Waste minimization may be achieved by source reduction or
recycling. Source reduction involves the implementation of steps
that reduce either the amount of wastewater generated or the
amount of volatile organic matter contained in wastewater
streams. Recycling includes recovery and/or reuse of potential
wastes. There are several means of achieving the objectives of
either of these waste minimization alternatives. Many waste
minimization techniques are process specific and the degree of
emission reduction achieved depends on the operating parameters
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of the individual process. The general approach to either source
reduction or recycling includes three steps: (1) gathering
baseline data on individual waste stream characteristics, (2)
identifying and ranking sources for reduction, and (3)
implementation of reduction/recycling alternatives. Selecting
and implementing waste minimization activities can be enhanced by
reviewing case studies and reports on pollution prevention or by
obtaining information from State assistance programs, vendors, or
consultants. Because of the site-specific nature of this
approach, no estimates of emission control efficiency were made.
4.2 Suppression and treatment technologies
Under this emission control strategy, VOC emissions are
reduced by a three-step program that includes: (1) suppression
of emissions from collection and treatment system components up
to the point of treatment; (2) treatment of wastewater streams to
remove organic compounds: and (3) treatment of residuals such as
oil phases, condensates, and sludges from nondestructive
treatment operations.
4.2.1 Organic compound treatment technologies. There are three
primary treatment technologies that are generally applicable and
effective in reducing the VO content of wastewater streams. They
are steam stripping, air stripping, and biological treatment.
There are also several other methods of treatment that may be
applicable to particular situations.
4.2.1.1 Steam stripping. Steam stripping is a proven technology
that involves the fractional distillation of wastewater to remove
organic compounds. Steam strippers may be operated in batch or
continuous mode depending on the characteristics of the
wastewater streams being treated. Steam stripping systems
include enclosed wastewater collection and handling units up to
the treatment unit, which includes a covered feed tank, a steam
stripping tower, and controls on associated tank and condenser
vents.
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Although the VOC removal efficiency of steam strippers
depends on the characteristics of both the steam stripper and the
wastewater stream, steam stripping is the most universally
applicable VOC removal technology for treating wastewater streams
such as those generated by SOCMI processes. Data collected by
EPA related to steam stripper performance for the treatment of
wastewaters indicate organic compound removal efficiencies
ranging from 76 percent to 99.9 percent. The Agency used that
information in conjunction with model waste streams to develop
equations to predict steam stripper removal efficiency as a
function of the Henry's Law Constant for individual organic
constituents of wastewater streams. These equations were then
used to estimate VOC removal efficiencies and emission reductions
for several industries. The four equations developed are as
follows:
Henry's Law Constant (H)
25 °F range (atm ! mVmol!
Fraction Removed (FJ
H > 0.00105
H < 3.3 x ID'7
3.3 x 10~7 < H < 8.9 x 10~6
8.9 x ID'6 < H < 1.05 x ID'3
Fr = 1.0
Fr = 0
Fr = 4.168 + 0.6430 * log H
Fr = 1.115 + 0.03865 * log H
4.2.1.2 Air stripping. Air strippers operate on the principle
of vapor-liquid equilibrium. The technology is applicable to
compounds with a wide range of volatilities and is most generally
applicable to streams that contain dilute organic compound
concentrations. Air strippers are most efficient in the removal
of highly volatile, water insoluble compounds.
As with steam stripping, air strippers may be operated in
either batch or continuous mode and operate as part of a system
that includes enclosed wastewater collection and handling units
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up to the treatment unit. The overhead from the treatment unit
including the feed tank is covered and vented to a control
device, which may be an on-site boiler. Data collected by EPA
indicate that the organic removal efficiency of air strippers
ranges from about 58 to 99.9 percent for a range of organic
compounds.
4.2.3 Biological treatment technology. Biological waste
treatment is normally accomplished through the use of aeration
basins. Microorganisms require oxygen to carry out the
biodegradation of organic compounds. The aerobic environment is
normally achieved by the use of diffused or mechanical aeration.
Although the aeration is necessary to provide the oxygen
necessary to maintain and promote biological degradation of the
organic compounds, aeration also increases the liquid surface
area exposed to ambient air. This action reduces both the liquid
and gas phase resistance to mass transfer and thus causes an
increase in air emissions relative to quiescent, flow-through
type units.
Biological treatment in open basins is unlikely to result in
the same level of VOC emission reduction that can be achieved by
steam or air stripping. However, some biological treatment
systems that make use of covered tanks vented to a control device
may achieve emission reductions equivalent to that of strippers.
4.2.4 Other organic compound removal technologies. In addition
to the three primary technologies for removing organics from
wastewater, there are certain applications where other
technologies may be more appropriate. These other technologies
include chemical oxidation, carbon and ion exchange adsorption,
membrane separation, and liquid-liquid extraction (or solvent
extraction). These technologies rely on a variety of mechanisms
to remove organic compounds from wastewater. They are used in
different applications by facilities and may be effective at
removing certain organic compounds.
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4.3 Emissions suppression
VOC emissions from wastewater collection and treatment
systems can be controlled either by hard piping or by enclosing
the transport and handling system from the point of wastewater
generation until the wastewater is treated to remove or destroy
the organic compounds. Suppression techniques can be broken down
into four categories: collection system controls, roofs,
floating membranes, and air-supported structures. These devices
and their associated VOC suppression efficiencies are discussed
in detail in the Wastewater CTC Document.2 Suppression of VOC
emissions merely keeps the organic compounds in the wastewater
until they reach the next potential VOC emission source.
Therefore, these techniques are not effective unless the VOC
emissions are suppressed until the wastewater reaches a treatment
device where the organic compounds are either removed or
destroyed.
Wastewater collection systems are made up of components such
as drains, junction boxes, sumps, trenches, and lift stations.
Other wastewater system components may include storage and
treatment tanks, oil/water separators, and surface impoundments.
Suppression controls can be applied to most of these components
to reduce the potential for VOC emissions during wastewater
collection. These controls involve the use of physical covers
and water seals to minimize the contact between ambient air and
the wastewater flowing through the component. Table 4-1 lists
some of the controls that are applicable to collection system
components. A complete description of each suppression control
device can be found in the Wastewater CTC Document.2
Table 4-1. EMISSION SUPPRESSION CONTROLS FOR WASTEWATER
COLLECTION SYSTEM COMPONENTS
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Collection System Component
Drains
Junction boxes
Sumps
Lift stations
Storage tanks
Treatment tanks
Oil/water separators
Surface impoundments
Suppression Control Options
Hard piping
P-leg seals
Seal pots
Gas-tight covers
Fixed roof
Fixed roof with internal
floating roof
Fixed roof vented to control
device
Floating roof
Fixed roof
Floating roof
Floating membrane covers
Air-supported structures
4.4 Add-on controls
Add-on controls serve to reduce VOC emissions by destroying
or extracting organic compounds from gas phase vent streams
before they are discharged to the atmosphere. Add-on controls
are applicable to vents associated with collection and treatment
covers, such as drain covers, fixed roofs, and air-supported
structures, and with organic compound removal devices, such as
air strippers and steam strippers. Add-on controls for VOC
emissions are classified into four broad categories: adsorption,
combustion, condensation, and absorption. The type of add-on
control best suited for a particular wastewater emission source
depends on the size of the source and the characteristics of the
wastewater in the source.
Combustion destroys the organic compounds in the gas stream
by oxidation of the compounds primarily to carbon dioxide and
water. Because essentially all organic compounds will burn,
combustion add-on controls are applicable to all emission sources
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for which the organic vapors can be captured. Combustion add-on
controls are thermal vapor incinerators, flares, boilers, and
process heaters.
4.4.1 Carbon adsorbers. Carbon adsorbers make use of carbon
that has been processed or "activated" to have a porous
structure. In that state, carbon provides a large surface area
upon which organic molecules can attach when an organic-
containing gas stream is passed through the carbon bed. Carbon
adsorbers are used in two main forms: fixed-bed and carbon
canisters. In fixed-bed systems, when the carbon becomes
saturated with organic material, it is regenerated to desorb the
attached organic material. In most situations, fixed-bed systems
make use of multiple carbon beds such that when one bed is in the
process of regeneration, the other beds are on-line to adsorb
organic material from a gas stream.
Carbon canisters are simple drums filled with activated
carbon and equipped with inlet and outlet openings. Carbon
canisters are used mostly with low volume gas streams with low
organic concentrations. When the carbon in the canister become
saturated, the canister is replaced and the carbon is either
incinerated or recycled.
4.4.2 Thermal vapor incinerators. Thermal vapor incinerators
consist of an enclosed chamber in which the oxidation process
occurs. They may be refractory-lined with one or more discrete
burners that premix organic vapor gas with combustion air and
supplemental fuel or, they may use plate-type burners to produce
a flame zone through which organic vapors pass. Packaged thermal
vapor incinerators are commercially available in sizes ranging
from 8 to 1,400 m3/min (300 to 47,000 ftVmin) . When properly
designed and operated, thermal vapor incinerators can achieve
organic compound destruction efficiencies in excess of 98
percent.
4.4.3 Combination adsorption-incineration. In some cases, it is
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advantageous to combine carbon adsorption and thermal vapor
incineration into a single control system. In these systems, the
carbon adsorption unit serves to increase the organic
concentration of the gas stream delivered to the thermal vapor
incineration unit thus reducing the requirements for auxiliary
fuel. These combination systems eliminate the need for solvent
recovery in situations where recovery of the organics is not
desirable or economically attractive.
Combination systems may be operated either continuously or
on an intermittent basis. Packaged units are available in a wide
range of capacities and operate at organic compound destruction
efficiencies of 95 to 99 percent.
4.4.4 Catalytic vapor incinerators. Catalytic vapor
incinerators are basically a flameless combustion process in
which organic vapor streams are passed through a catalyst bed to
promote oxidation at temperatures of 320 to 650 °C (600 to 1,200
°F). These incinerators may not be applicable for vapor streams
with a high organic concentration because of the likelihood that
the temperature limits would be exceeded thus leading to damage
to the catalyst. In most installations, heat recovery is
employed to heat the inlet vapor stream using heat from the hot
exhaust gases. Organic compound destruction efficiencies in the
range of 97 to 98 percent can be achieved by these systems.
4.4.5 Flares. Flares consist of an open combustion process in
which oxygen for the combustion process is provided by ambient
air around the flare. Mixing of air and organic vapors may be
enhanced or "assisted" by injecting steam or air at the flare tip
or by using a high-velocity nozzle. Flares are primarily used to
burn waste gases from industrial processes such as those at
petroleum refineries, blast furnaces, and coke ovens. Combustion
efficiencies of up to 98 percent are achievable for assisted
flares under most operating conditions.
4.4.6 Boilers and process heaters. Thermal destruction of
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organic vapors may be achieved in boilers and process heaters at
many plants. The two processes currently being used for this
application include: (1) premixing the organic vapor with a
gaseous fuel and firing through an existing burner and (2) firing
the organic vapor through a special retrofitted burner.
Destruction efficiencies of 98 to 99 percent have been achieved
by boilers and process heaters in this application.
4.4.7 Condensers. Condensation may be used on organic vapor
streams to recover the organic material by converting the vapors
to a liquid form. In most applications, the conversion is
achieved by lowering the temperature, although increasing the
pressure may also be used. The efficiency of condensers is
highly dependent on the vapor pressure of the organic
constituents in the vapor stream. Field measurements of
efficiency have shown values ranging from 6 to 99.5 percent for
different chemical compounds.
4.5 References
1 U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Guideline Series Control of
Volatile Organic Compound Emissions from Industrial
Wastewater. Research Triangle park, NC. Draft. September
1992. Chapter 4.
2. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Industrial Wastewater Volatile
Organic Compound Emissions—Background Information for
BACT/LAER Determinations. July 1990.
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5. MODIFICATION AND RECONSTRUCTION
New Source Performance Standards (NSPS) apply to new,
modified, and reconstructed (i.e., whose components are replaced
to the extent that the source is, in effect, a new source)
sources for which construction, modification, or reconstruction
commenced (as defined under 40 CFR 60.2) after the date of
proposal of the standards. Under Section 111 of the Clean Air
Act, a source can be any building, structure, facility, or
installation which emits or may emit any air pollutant. The
sources to which each NSPS apply are defined in the standard as
the "affected facility". Regulations governing modification and
reconstruction are found in §60.14 and §60.15 of 40 CFR Part 60.
This chapter will discuss the selection of affected
facility, and provide some general examples of the applicability
of modification and reconstruction to affected facilities in the
SOCMI.
5.1 SELECTION OF AFFECTED FACILITY
The Synthetic Organic Chemical Manufacturing Industry
(SOCMI) is normally represented as a system of production stages
that produces a wide range of organic chemicals. For the purpose
of this NSPS, the SOCMI is defined as the production of organic
chemicals, at a wide range of facilities, through different
production stages known as process units. In the manufacture of
organic chemicals, wastewater streams containing organic
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compounds may be generated from several sources. Organic
compounds in the wastewater can volatilize and be emitted to the
atmosphere from wastewater collection and treatment units if
these units are open to the atmosphere. Potential sources of VOC
emissions associated with wastewater collection and treatment
include: individual drain systems, which are comprised of
equipment such as open trenches, drains, sumps, manholes,
junction boxes, lift stations, and weirs; surface impoundments;
wastewater storage and/or treatment tanks; clarifiers; oil/water
separators; and biological treatment units. At these points, VOC
can be transferred from the wastewater to the air.
For the purpose of this NSPS, the affected facility is
defined as each individual process unit, i.e., each SOCMI process
unit which includes the equipment (e.g., mixers, reactors,
distillation units) assembled and connected by pipes or ducts to
produce, as intermediates or final products, one or more of the
chemicals listed in the NSPS applicability section. This
regulatory format avoids the problems associated with having
multiple individual collection and treatment system components
classified as affected facilities and also provides a definition
that is sufficiently narrow in scope as not to totally eliminate
the potential for existing sources becoming subject to NSPS
through the modification and reconstruction provisions. In
addition, this format will allow the plant to make modifications
to update wastewater collection and treatment systems as
necessary to enhance their performance without causing the system
to be classified as an affected facility under this NSPS.
5.2 MODIFICATION
Regulations governing modification determination for the
purposes of applying NSPS are contained in §60.14 of the General
Provisions to 40 CFR Part 60. With certain exceptions, any
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physical or operational change to an existing process unit that
would increase the emission rate from that process unit of any
pollutant covered by the standard would be considered a
modification within the meaning of Section 111 of the Clean Air
Act. The key to determining if a change is considered a
modification is whether actual emissions to the atmosphere from
the process unit have increased on a mass per time basis (kg/h)
as a result of the change. Changes in emission rate may be
determined by the use of emission factors, by material balances,
by continuous monitoring data, or by manual emission tests in
cases where the use of emission factors does not clearly
demonstrate that emissions do or do not increase. Under the
current regulations, an emission increase from one process unit
may not be offset with a similar emission decrease at another
process unit to avoid becoming subject to NSPS. If an existing
facility is determined to be modified, it becomes an affected
facility, subject to the standards of performance for the
pollutant or pollutants that have increased due to modification.
All emissions, not just the incremental increase in emissions, of
the pollutants that have increased from the affected facility
must be in compliance with the applicable standards.
Under the General Provisions to 40 CFR Part 60, certain
physical or operational changes are not considered to be
modifications even though emissions may increase as a result of
the change (see 40 CFR 60.14(e)). The following physical or
operational changes are not considered to be modifications, even
though they may cause emissions to increase:
1. Routine maintenance, repair, and replacement (e.g.,
lubrication of mechanical equipment; replacement of pumps,
motors, and piping; cleaning of equipment);
2. An increase in production rate without a capital
expenditure (as defined in 40 CFR 60.2);
3. An increase in the hours of operation;
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4. Use of an alternative fuel or raw material if, prior to
proposal of the standard, the existing facility was designed to
accommodate that alternative fuel or raw material;
5. The addition or use of any system or device whose
primary function is to reduce air pollutants, except when an
emission control system is replaced by a system determined by EPA
to be less environmentally beneficial; and
6. Relocation or change in ownership of the existing
facility.
An owner or operator of an existing facility who is planning
a physical or operational change that may increase the emission
rate of a pollutant to which a standard applies shall notify the
appropriate EPA regional office 60 days prior to the change, as
specified in 40 CFR 60.7 (a) (4).
The following discussion identifies some possible changes to
process unit operations used in SOCMI which might be considered
modifications. The magnitude of the industry covered and the
complexity of the manufacturing process permit only a general
discussion of these possible changes. Furthermore, the list of
potential modifications for process units is not exclusive. The
following general types of process modifications are identified
for SOCMI process units:
1. Feedstock, catalyst, or reactant substitution;
2. Process equipment changes; and
3. Combinations of the above.
Feedstock, catalyst, or reactant substitution is dictated by
economics and the level of availability of the feedstock,
catalyst, or reactant. Depending upon the specific process,
change in feedstock or catalyst may require substantial capital
investment to modify the process to accommodate the change. The
magnitude of the capital investment may prohibit feedstock or
catalyst substitution for many chemicals.
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Many of the chemicals produced in the SOCMI can be
manufactured from two or more different feedstocks. For example,
cyclohexane can be manufactured using either phenol or
cyclohexanol as the feedstock. In most cases, however, feedstock
substitution would likely require both equipment and process
changes.
Reactant substitutions within the SOCMI process units is
also a likely change that could constitute a modification. For
example, for many chemicals, the potential exists to substitute
air for pure oxygen or a chemical oxidant as a reactant or vice
versa. Changing to an air oxidation process may be an advantage
because (1) air is readily available and (2) expensive corrosion-
resistant materials are not required compared to the use of
chemical oxidants. However, there may be major disadvantages in
changing from an oxygen or chemical oxidation process to an air
oxidation process, including a substantial reduction in plant
capacity, a large increase in the reactor-related process vent
stream flowrate (i.e., increased VOC emissions), and an altered
product mix. Either of these (i.e., using pure oxygen or the
oxygen in the air) may be substituted for chemical oxidation
processes as well. Reactant substitutions of this type may
increase process unit VOC emissions to the atmosphere and as a
result may constitute a modification (unless the fixed capital
expenditure exceeds 50 percent of the fixed capital cost required
to construct a comparable new facility, in which case it would be
considered reconstruction).
Process equipment changes may also constitute modifications.
Examples of potential modifications are replacing a fixed-bed
reactor with a fluidized-bed reactor, increasing the plant
capacity by increasing the size of the reactor or adding
additional reactors, and changing the product recovery system
(e.g., from an absorber to a condenser). Such changes might be
considered modifications since they can result in increased VOC
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emissions. Again, capital expenditures may be a factor in
determining whether it is modification or reconstruction.
A combination of the changes described above would be chosen
in any given situation with the decision based on the most
advantageous economics for the site-specific conditions. The
combination of changes might be considered a potential
modification if they resulted in an increase in emissions. The
most common combinations are plant expansions or simultaneous
changes in feedstock and catalyst as described earlier. Other
combinations however are possible.
The enforcement division of the appropriate EPA regional
office will make the final determination as to whether an
existing facility is modified and, as a result, subject to the
standards of performance of an affected facility.
5.3 RECONSTRUCTION
An existing facility may become subject to NSPS if it is
reconstructed. Reconstruction is defined in 40 CFR 60.15 as the
replacement of the components of an existing facility to the
extent that (1) the fixed capital cost of the new components
exceeds 50 percent of the fixed capital cost required to
construct a comparable new facility and (2) it is technically and
economically feasible for the facility to meet the applicable
standards. Because EPA considers reconstructed facilities to
constitute new construction rather than modification,
reconstruction determinations are made irrespective of changes in
emission rates.
The purpose of the reconstruction provisions is to
discourage the perpetuation of an existing facility for the sole
purpose of circumventing a standard that is applicable to new
facilities. Without such a provision, all but vestigial
components (such as frames, housing, and support structures) of
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the existing facility could be replaced without causing the
facility to be considered a "new" facility subject to NSPS. If
the facility is determined to be reconstructed, it must comply
with all of the provisions of the standards of performance
applicable to that facility. If an owner or operator of an
existing facility is planning to replace components and the fixed
capital cost of the new components exceeds 50 percent of the
fixed capital cost of a comparable new facility, the owner or
operator must notify the appropriate EPA regional office 60 days
before construction of the replacement commences, as required
under 40 CFR 60.15(d).
The enforcement division of the appropriate EPA regional
office will make the final determination as to whether an
existing facility is reconstructed and, as a result, subject to
the standards of performance of an affected facility.
5.4 REFERENCES FOR CHAPTER 5
1. The U.S. Environmental Protection Agency. Code of Federal
Regulations. Title 40, Chapter I, Subpart A, part 60.
Washington, B.C., Office of the Federal Register.
2. The U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards, Research Triangle Park, N.C.
Distillation Operations in Synthetic Organic Chemical
Manufacturing - Background Information For Proposed
Standards. EPA-450/3-83-005a. December 1983.
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6.0 METHODOLOGY FOR ESTIMATING BASELINE AND CONTROLLED ORGANIC
EMISSIONS
This chapter presents a general discussion of the
methodology used to develop estimates of volatile organic
compound (VOC) emissions from wastewater operations within the
SOCMI source category. The chapter includes: (1) an explanation
of the assumptions used to establish the regulatory baseline for
the impact analyses, (2) descriptions of the control options used
in the impact analyses, and (3) the techniques applied to
estimate both baseline and controlled emissions.
6.1 BASELINE CHARACTERIZATIONS
The EPA has recently been involved with two regulatory
efforts that relate to air emissions from wastewater streams at
SOCMI facilities: development of the Industrial Wastewater
Control Techniques Guidelines (CTG) document,1 and development of
the Hazardous Organic NESHAP (HON).2 In support of those
efforts, the EPA conducted a survey of SOCMI facilities under the
authority of Section 114 of the Clean Air Act. In that survey,
owners and operators of facilities within nine corporations
completed questionnaires asking for information on wastewater
streams from SOCMI production processes. The questionnaires
included information on the flow rate and concentration of
individual hazardous air pollutants (HAP's) and total VOC's in
each wastewater stream. The Agency used the survey responses to
establish a data base (referred to herein as "the SOCMI data
base") with data for a total of 461 wastewater streams generated
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by 110 SOCMI process units at 25 plant sites. The survey
responses provided sufficient information to allow the
characterization of flow rate, VO concentration, emission
potential, and strippability of individual wastewater streams.
VO concentration refers to the volatile organic
concentration of a wastewater stream as measured by EPA Method
25D. The regulatory alternatives considered for this NSPS are
based on controlling wastewater streams with a VO concentration,
as measured by Method 25D, above specified trigger or action
levels. The EPA calculated values for VO concentration for the
SOCMI wastewater streams from reported values of the
concentrations of individual volatile organic constituents. In
that calculation, each reported individual constituent
concentration in a waste stream is multiplied by an estimated
fraction of the total that would be detected by EPA Reference
Method 25D and summed across all constituents. This procedure
can be expressed in an equation as follows:
vo = Y, (voci *fm)
/
/
Where,
VO = Volatile organic concentration as measured by EPA Method
25D;
VOC± = Total concentration of volatile organic compound i; and
fm± = The fraction of total volatile organic compound i
measured by EPA Method 25D, predicted for compounds of
interest using a theoretical analysis.
This VO concentration calculation allows analyses to be made of
the SOCMI data base that involves control of those wastewater
streams with VO concentrations above specified levels.
6.2 BASELINE AND CONTROLLED EMISSIONS ESTIMATES
The environmental and other impacts of alternative standards
are evaluated by establishing a baseline to which all regulatory
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alternatives are compared. For the SOCMI secondary sources NSPS,
VOC emissions at affected facilities in the absence of the NSPS
represent baseline. As discussed in Chapter 1, air emissions
from SOCMI secondary sources are already covered by air emission
regulations at what is likely to be a large fraction of
facilities. The HON applies to SOCMI wastewater sources that
contain HAP's in concentrations above the trigger level. In
addition, some SOCMI wastewater sources may be covered by either
the NESHAP for vinyl chloride or the NESHAP for benzene waste
operations. Sources that would be subject to this NSPS include
process units that have HAP concentrations in their wastewater
below the cutoff level for the HON and process units for which
the wastewater contains VOCs that are not classified as HAPs.
This category of sources has the potential to be a significant
source of VOC air pollutant emissions and is the primary focus of
the NSPS.
Baseline emissions for SOCMI wastewater streams are
calculated using the information and methodology presented in the
BID for the HON as previously referenced. Baseline emissions are
calculated as uncontrolled emissions using emission factors
developed as a part of the analysis of waste stream data for the
HON. That analysis involved development of emission factors for
individual organic constituents found in SOCMI wastewater streams
based on information in the SOCMI data base.3 Those emission
factors (or fractions emitted, fe) were developed using
theoretical mass transfer equations to calculate emission factors
for individual organic chemical constituents in a wastewater
stream as the stream passes through individual wastewater
collection and treatment units. The calculated individual values
for fraction emitted were used to establish a relationship
between fraction emitted and Henry's Law constant for individual
organic constituents. That relationship is used to estimate the
fraction emitted for constituents that do not have a value
6-3
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calculated for fraction emitted based on theoretical
considerations .
Uncontrolled VOC emissions from typical wastewater
collection and treatment systems are estimated as the sum of the
products of the fraction emitted and the individual constituent
concentration of a waste stream. The calculations are made using
the following equation:
E = £ (Q * VOC, * fe,.)
/
Where :
E = Annual VOC emissions from the wastewater stream, (Mg/yr) ,
Q = Annual wastewater stream flow (calculated based on the
reported stream flow in 1pm and full time operation for 351
days/yr) , (M3/yr) ,
VOC± = Concentration of constituent i, (ppm) ,
fe± = Fraction emitted for constituent i.
Annual emissions from individual units can be calculated by
summing across all wastewater streams generated by the unit.
Annual emissions from a plant can be calculated by summing across
all units at the plant.
Calculations are also made to estimate total VOC emissions
after the controls required by the NSPS have been installed. For
those calculations, emission control was assumed to be
accomplished by processing the waste streams through a steam
stripper. The fraction of VOC that would be removed by steam
stripping was estimated by first predicting the VOC removal
efficiency of a model steam stripper for each individual volatile
organic constituent and then summing across all constituents.
This analysis can be expressed in an equation as follows:
6-4
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FR = £ (VOC, * fr,)
Where,
FR = The fraction of total VO removed from a wastewater stream
due to steam stripping, or the fractional reduction in
emission potential;
6-5
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VOC± = The VOC concentration of compound i;
fr± = The fraction of compound i removed by steam stripping
from a wastewater stream.
Estimates of steam stripper efficiency for individual compounds
are based on the predicted efficiency of the design steam
stripper as described in Chapter 4 of the Industrial Wastewater
CTG.4
6.3 REFERENCES
1. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Guideline Series Control of
Volatile Organic Compound Emissions from Industrial
Wastewater. Research Triangle Park, NC. Appendix B.
Draft. September 1992.
2. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Hazardous Air Pollutant Emissions
from Process Units in the Synthetic Organic Chemical
Manufacturing Industry -- Background Information for
Proposed Standards Volume 1C: Model Emission Sources. EPA-
453/D-92-016c. Research Triangle Park, NC. p. 5-10 - 5-29.
November 1992.
3. Reference 1.
4. Reference 1. Chapter 4.
6-6
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7.0 NATIONWIDE ENVIRONMENTAL AND ENERGY IMPACTS
As part of the rulemaking process, EPA estimates the
nationwide impacts of various regulatory alternatives in terms of
primary air pollutant impacts, cost impacts, and other
environmental and energy impacts. These estimates represent the
impacts of applying emission controls on all emission points
nationwide that are required to apply additional control as a
part of complying with the NSPS. These estimated impacts are
factored into decisions regarding selection of the most
appropriate regulatory alternative to serve as the basis for a
proposed standard.
In estimating nationwide impacts, EPA estimates the quantity
of emissions from the affected industry in the absence of
national standards to serve as a baseline emission level, and
then calculates potential emission reductions under alternative
emission control scenarios (i.e., regulatory alternatives).
Studies are then made to estimate impacts of these alternatives
on the environment, the economics of the industry and the nation,
and on energy consumption. Collectively, these estimates
represent the impacts of the standard. For this NSPS, impact
estimates were made on both a model plant basis and on a national
basis. The impacts of regulatory alternatives for emission
control include emission reductions, costs, impacts to other
environmental media, and changes in energy usage.
7.1 BASIS FOR IMPACTS ESTIMATION
7-1
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Impacts of the regulatory alternatives for the SOCMI
secondary sources NSPS were estimated as an increment to the
impacts calculated for the hazardous organic NESHAP (HON). In
effect, the level of emissions after implementation of the HON
serves as the baseline for the NSPS.
The estimated nationwide impacts of the NSPS are based on
detailed analyses of the SOCMI data base described in Chapter 6.0
of this document. For the purposes of the analysis, the EPA
assumed that the information in that data base is representative
of new process units that will be subject to control by the NSPS.
The analysis examined each individual wastewater stream in the
SOCMI data base to determine if emission controls would be
required by the HON. The determination was based on the HON
criteria for new sources, which differ from the criteria for
existing sources. The estimated emission reductions and costs of
controlling these waste streams were then calculated using the
procedures discussed in Chapter 6.
Following the examination of the wastewater streams based on
the HON criteria, each wastewater stream not requiring control by
the HON was reexamined to identify those streams that would
require control by the NSPS. Emission reductions and costs of
controlling those streams represent the impacts of the NSPS.
NSPS impacts were analyzed in this way for a series of 5
regulatory alternatives with progressively more stringent
criteria for wastewater streams that require control.
7.2 ESTIMATION OF CONTROLLED EMISSIONS
The control technology evaluated for wastewater collection
and treatment operations was a steam stripper followed by an air
emissions control device (i.e., the emission potential of the
wastewater stream is reduced by removing the organics from the
wastewater prior to management in units that result in air
emissions). Steam stripping achieves variable emission
reductions depending on the volatility and strippability of the
7-2
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organics (e.g., VOC or HAP's) in the wastewater. For the purpose
of estimating the control impacts, it was assumed that the air
emissions control device was an existing combustion device such
as a thermal vapor incinerator or process heater.
Control impacts for wastewater collection and treatment
operations were estimated on a facility basis. Control costs
were evaluated based on the total facility-wide wastewater flow
as related to production rate. Emission reductions, a function
of strippability and the quantity of wastewater treated, were
estimated for each wastewater stream.
7.3 ESTIMATION OF NSPS IMPACTS
7.3.1 Approach to Impacts Estimation
The NSPS will require control of all wastewater streams that
contain VOC's in excess of a specified trigger level and, in some
cases, that also have a stream flow rate above a specified
minimum value. Thus, the NSPS will require SOCMI plants to
control some wastewater streams that do not require control under
the HON or other air rules. Many of the plants that are affected
by the NSPS will also be affected by the HON and are anticipated
to be required to install a steam stripper for treating those
wastewater streams regulated by the HON. In estimating cost
impacts of the NSPS, EPA assumed that those plants affected by
the NSPS that are also affected by the HON would increase the
capacity (or operating hours) of the steam stripper required
under the HON to handle the additional wastewater streams that
would require control under the NSPS. The cost associated with
the NSPS for those plants is the difference in costs for two
steam strippers, one with the capacity and operating hours to
handle wastewater streams regulated by the HON and the other with
the capacity and operating hours to handle wastewater streams
regulated by both the HON and the NSPS. Plants affected by the
NSPS that are not affected by the HON are assumed to install a
new steam stripper to comply with the NSPS.
7-3
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The Agency evaluated two different approaches for projecting
the results of the impacts estimates for the SOCMI data base to
nationwide impacts. In the first, nationwide impacts are
estimated as an increment to the impacts previously calculated
for the HON. In the second approach, nationwide impacts are
estimated based on the ratio of the total quantity of wastewater
generated by the facilities in the SOCMI data base and the total
quantity of wastewater generated nationwide by SOCMI plants. The
analyses were completed for 5 regulatory alternatives under
consideration as a basis for the NSPS. Each alternative is
defined by a specified action level defined in terms of a VO
concentration and stream flow. All wastewater streams having a
VO concentration and stream flow at or above the action level
would be subject to an NSPS based on that alternative. In
addition, under each alternative, streams with a VO concentration
above a specified maximum level also would be subject to the rule
regardless of the stream flow rate. Action levels for each of
the 5 regulatory alternatives are listed in Table 7-1.
7-4
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Table 7-1. NSPS Regulatory Alternatives
Alternative
No.
Baselineb
1
2
3
4
5°
VO Concentration
(ppmw)
1,000
800
500
100
0
Flow Rate
Cutoff
(1pm)
10
5
1
1
0
Maximum VO
Concentration3
(ppmw)
10,000
10,000
10,000
10,000
a Wastewater streams with a VO content above this level must be controlled regardless of
flow rate.
b Baseline is the level of control that would be applied to new sources without the NSPS.
0 Alternative 5 is total industry control (i.e., control all wastewater streams).
7.3.2 Results of Impacts Estimation
7.3.2.1 Incremental approach based on RON impacts. Under
this approach, nationwide impacts for the NSPS are estimated as
an increment applied to the HON impacts that were estimated as
part of the regulatory development effort in support of the HON.
To obtain the incremental impacts, an analysis consisting of
three steps was performed as follows:
1. Using the HON impacts as a baseline, incremental emissions
and cost impacts for each of the five NSPS regulatory
alternatives were calculated using the SOCMI data base.
2. Using the SOCMI data base analysis, the percentage increase
in emission reductions and costs for each NSPS alternative
relative to the emission reductions and costs for the HON
were calculated.
3. The percentage changes in emissions and costs were applied
to the estimated industry-wide emissions and costs for new
plants as calculated for the HON. (The HON impacts for new
plants in the fifth year is estimated at 16 percent of the
total impacts in the fifth year.)
7-5
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The results of steps 1 and 2 of this approach are presented in
Table 7-2. That table, based on analyses of the SOCMI data base,
shows the estimated VOC emission reduction and costs for
complying with the HON and the VOC emission reductions and costs
of complying with each of the five NSPS regulatory alternatives.
7-6
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Table 7-2. Emission Reductions and Costs for HON and NSPS*
Regulatory
Alternative
1
2
3
4
5
VOC Emission
Reductions (Mg/yr)
HON
5,626
5,626
5,626
5,626
5,626
NSPS
7,007
7,112
7,340
7,589
8,053
Percent
Increase
24.55%
26.41%
30.47%
34.89%
43.14%
Total Annual Costs
($106)
HON
$5.32
$5.32
$5.32
$5.32
$5.32
NSPS
$6.00
$6.18
$6.92
$8.29
$13.34
Percent
Increase
12.78%
16.17%
30.08%
55.83%
150.75%
*Based on SOCMI data base.
Table 7-3. Nationwide Impacts of NSPS Options
Regulatory
Alternatives
1
2
3
4
5
Emission
Reduction
(Mg/yr)
14,534
15,635
18,038
20,655
25,539
Total Annual
Costs ($)
$1,022,556
$1,293,233
$2,406,015
$4,466,165
$12,060,150
Cost
Effectiveness
($/Mg)
$70
$83
$133
$216
$472
Incremental Cost
Effectiveness ($/Mg)
-
$246
$463
$787
$1,555
7-7
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The percentage increase in both emission reduction and cost are
also presented for each regulatory alternative.
The results of step 3 are presented in Table 7-3, which
shows calculated nationwide VOC emission reductions and costs
attributable to the NSPS under each of the regulatory
alternatives. The basis for these numbers is the estimated
nationwide fifth year impacts estimated for the wastewater
portion of the HON which are as follows:
VOC emission reduction - 370,000 Mg/yr
Total annual cost - $50,000,000
Total capital Investment - $140,000,000
Sixteen percent of these estimated total nationwide emission
reductions and cost are attributable to new sources of emissions
constructed during the first 5 years of the rule. Fifth year
impacts of the NSPS were estimated by escalating the new source
impacts for the HON by the calculated fractional increases shown
in Table 7-2.
Equation 1 is an example calculation for estimating the
emission reduction associated with regulatory alternative 1 using
the above steps.
Er = 0.16 x 370,000 x 0.2455 = 14,534 Mg/yr (1)
Where:
Er = emission reduction (Regulatory alternative 1 in Table 7-
3),
0.16 = percentage of estimated total HON emissions reduction
attributable to new sources,
370,000 = Estimated nationwide emission reduction from wastewater
sources due to the HON, and
0.2455 = Fractional increase in emission reduction for the NSPS
relative to the HON (Regulatory Alternative 1 in Table
7-2) .
-------
7-9
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Table 7-4. Emission Reductions and Costs for NSPS Alternatives*
In the Fifth Year After Promulgation
Regulatory
Alternative
1
2
3
4
5
Controlled
Wastewater
Flow (1pm)
1,309
1,675
3,221
6,049
20,289
Fraction
Wastewater
Controlled
0.043
0.055
0.105
0.197
0.661
Fmission
Reductions
(Mg/yr)
1,382
1,487
1,714
1,964
2,428
Total
Annual
Costs
($106)
0.696
0.874
1.609
2.982
8.165
Cost
Effectiveness
($/Mg)
$504
$588
$938
$1,518
$3,363
Emission Red.
Per Unit Flow
(Mg/yr/lpm)
1.056
0.888
0.532
0.325
0.120
*Based on SOCMI data base.
Table 7-5. Nationwide Impacts of NSPS Options
in the Fifth Year after Promulgation
Regulatory
Alternatives
1
2
3
4
5
Emission
Reduction
(Mg/yr)
11,678
12,560
14,365
16,465
20,399
Total Annual
Costs ($)
$5,886,000
$7,385,000
$13,474,000
$24,994,000
$68,602,000
Cost
Effectiveness
($/Mg)
504
588
938
1518
3363
Incremental Cost
Effectiveness ($/Mg)
-
1700
3373
5486
11085
7-10
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7.3.2.2 Wastewater flow rate approach. The results of the
impacts estimates using this approach for each of the five
regulatory alternatives are presented in Table 7-4. That table
shows the emission reduction estimated to be achieved by each
regulatory alternative, the estimated total annual costs of
control for each regulatory alternative, and the cost
effectiveness of controlling emissions under each alternative.
In addition, the quantity of wastewater controlled by each
alternative as well as the percentage of total wastewater flow
controlled under each alternative are also calculated. These
figures serve as part of the basis for projecting the results of
the SOCMI data base analysis to nationwide impacts. The emission
reduction per unit of controlled wastewater flow is also shown.
Estimates of nationwide impacts of the NSPS use the
information in Table 7-4 (based on the analysis of the SOCMI data
base) coupled with recent estimates of (1) industry growth over
the next five years and (2) the nationwide quantity of wastewater
generated by SOCMI process units. As a part of the analysis of
the HON,l separate estimates of the impacts on new and existing
process units were developed. Estimation of the impacts on new
facilities were based on estimated industry growth. Based on
current economic trends in the industry, a figure of 3.5 percent
7-11
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per year was derived as an estimate of growth over the next 5
years .2
The nationwide annual rate of wastewater generation at SOCMI
facilities was estimated as a part of the analysis for the
Control Techniques Guideline (CTG) document for industrial
wastewater.3 In that document, the nationwide wastewater flow
for the organic chemicals, plastics, and synthetic fibers (OCPSF)
industry was estimated at 1,374,800 liters per minute (1pm).
Elsewhere in the documentation for that study,4 it was estimated
that SOCMI facilities account for about 99.5 percent of the OCPSF
industry. The EPA assumes that these values represent conditions
within the SOCMI for the purposes of the NSPS impacts
calculations.
Using the nationwide flow estimates, the estimated industry
growth, and the results of the analysis of the SOCMI data base,
the EPA derived estimates of the NSPS impacts in the fifth year
after promulgation. At a growth rate of 3.5 percent per year,
the total growth over 5 years would be approximately 18.8
percent. When applied to the estimated nationwide wastewater
flow of 1,374,800 1pm, the increase in wastewater generation in
the fifth year is estimated as:
Q = 1,374,800 x 0.188 x 0.995 = 257,170 Ipm
Using that value, the nationwide emission reduction for each
regulatory alternative is estimated using the following equation:
E = Q x fq x er
Where:
E = Estimated annual nationwide VOC emission reduction, (Mg/yr),
Q = Estimated growth in wastewater generation in the first 5
years, (1pm),
7-12
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fq = The fraction of wastewater requiring control under the NSPS
(from Table 7-4),
er = Annual VOC emissions reduction per unit of flow (from
Table 7-4), (Mg/yr/lpm).
The nationwide costs of each regulatory alternative are estimated
as the product of the emission reduction and the cost
effectiveness calculated for each alternative as presented in
Table 7-4. Both the estimated emission reductions and estimated
costs of each regulatory alternative are presented in Table 7-5.
7.3.2.3 Combined results. The two approaches to estimating
impacts yield widely different nationwide impacts and cost
effectiveness for the 5 regulatory alternatives. The Agency's
goal in pursuing two approaches was to have two sets of results
that would be mutually supportive of one another. That goal was
not achieved although the Agency believes that both approaches
are legitimate means of estimating impacts. Because the Agency
did not identify a sound basis for selecting one set of estimates
over the other, rather than discard one set of results, the
Agency chose to average the results of the two approaches. Table
7.6 presents the calculated averages for nationwide emission
reduction and total annual costs of the two approaches. Cost-
effectiveness, in units of $/Mg are also shown in that table.
All of the nationwide cost figures in Table 7-6 include the
estimated cost associated with the reporting and recordkeeping
burden that would be imposed by a regulation. That cost was
estimated to be $859,436 as described in the Information
Collection Request and supporting statement for the rule.5
Estimated total annual capital cost of each regulatory
alternative over the first five years of the rule were also
calculated as the average of the values derived by each of the
7-13
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Table 7-6 Estimated NSPS Impacts Based on Averaging
Average Cost
Effectiveness
Regulatory Emission Reduction (Mg/yr)
Alternative SOCMI HON Average SOCMI
Total Annual Costs ($)
HON
Average
($/Mg)
1 11,678
2 12,560
3 14,365
4 16,465
5 20,399
14,534
15,635
18,038
20,655
25,539
13,106
14,097
16,202
18,560
22,969
$6,745,000
$8,244,000
$14,333,000
$25,853,000
$69,461,000
$1,882,000
$2,153,000
$3,265,000
$5,326,000
$12,920,000
$4,313,500
$5,198,500
$8,799,000
$15,589,500
$41,190,500
$329
$369
$543
$840
$1,793
Table 7-7 Total Capital Costs Based on Averaging of Two Methods
Regulatory
Alternative
1
2
3
4
5
SOCMI
$1,901,941
$2,432,128
$4,285,258
$8,087,457
$23,769,213
Fifth Year Capital Costs ($)
HON
$3,218,880
$4,114,880
$7,250,880
$13,684,160
$34,126,400
Average
$2,560,411
$3,273,504
$5,768,069
$10,885,809
$28,947,807
two approaches. These costs are presented in Table 7.7.
In both approaches to impacts estimation, the cost analysis
assumes a mix of individual plant costs depending on whether or
not a plant is affected by both the NSPS and the HON or is
affected only by the NSPS. The plant by plant cost analysis for
plants in the SOCMI data base indicate that the average NSPS
compliance costs for plants installing a new steam stripper are
approximately a factor of 3 higher than the costs for plants that
use the same steam stripper for compliance with both the HON and
the NSPS. The analysis also shows that approximately 12 percent
7-14
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of plants would need to install new steam strippers to comply
with the NSPS.
7.4 OTHER ENVIRONMENTAL AND ENERGY IMPACTS
Some adverse effects on air quality and other environmental
media and increased energy requirements are associated with the
use of emission control devices such as steam strippers to
control emissions from wastewater operations. Impacts associated
with air quality and other media include emissions of NOX and CO
and the generation of solid waste and water pollution. This
section presents a brief discussion of estimated environmental
and energy impacts associated with steam stripping wastewater
streams. The discussion is based on the analysis undertaken in
development of the HON6, which is briefly summarized here.
7.4.1 Secondary Air Pollution Impacts
Secondary air impacts associated with steam stripping can
occur from two sources: (1) combustion of fossil fuels for steam
and electricity generation, and (2) handling or combustion of
recovered organics. The analysis for the HON assumed proper
handling of recovered organics by either recycling to the process
or by combustion. The impacts of off-site electricity generation
were not estimated in the analysis and, as a result, the
calculated secondary air impacts are associated only with the
generation of steam for the steam stripping operations. Based on
industry-wide average fuel usage, secondary air pollution impacts
were estimated for both NOX and CO.
7.4.2 Other Impacts
Steam stripping also has impacts on other environmental
media and on energy consumption. Following are brief discussions
of these other impacts.
7.4.2.1 Water Pollution Impacts. Steam strippers remove
organics from wastewater, thus improving the quality of
wastewater being discharged to a wastewater treatment plant or
7-15
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POTW. Therefore, their use has an overall positive impact on
water pollution.
7.4.2.2 Solid and Hazardous Waste Impacts. Solid and
hazardous waste can be generated from recovered organics, solids
removal, and control system vent emissions. Additional solid
waste may be generated in situations where system vent emissions
are collected on sorbent media that are not regenerated. For the
NSPS, solid waste impacts are estimated to be negligible.
7.4.2.3 Energy Impacts. Fossil fuel used to generate steam
for steam stripping systems can reduce available nonregenerable
resources such as coal, oil and natural gas. The impacts are
partially offset if recovered organics are recycled or used as
supplemental fuel.
7.4.3 Impacts Estimates
For the purpose of estimating secondary environmental and
energy impacts for the NSPS alternatives, it was assumed that the
secondary environmental and energy impacts are directly
proportional to the emission reduction achieved using the steam
stripping control options. Using the analysis from the HON, the
magnitude of each secondary impact per unit of emission reduction
was calculated. These values were then used to calculate
secondary environmental and energy impacts of the NSPS
alternatives. Estimated impacts for the HON are as follows:7
! Carbon monoxide emissions 100 Mg/yr
! NOX emissions 800 Mg/yr
! Electricity usage 13 x 106 kw-hr/yr
! Natural gas usage 3 x 109 Btu/yr
! Steam usage 3,000 x 109 Btu/yr.
These figures are used to derive a value for the magnitude of
each impact per unit of emission reduction by dividing each by
the estimated total emission reduction of 370,000 Mg/yr. The
resulting values are:
! Carbon monoxide emissions .00027 Mg/yr
7-16
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! NOX emissions
! Electricity usage
! Natural gas usage
! Steam usage
.00216 Mg/yr
.0000351 x 106 kw-hr/yr
3.00000811 x 109 Btu/yr
.00811 x 109 Btu/yr.
Nationwide impacts for the NSPS alternatives are obtained by
multiplying the unit impact values by the estimated emission
reduction for each alternative as estimated in Table 7-6. The
results of these calculations are provided in Table 7-8.
Table 7-8. Other Environmental and Energy Impacts
in the Fifth Year after Promulgation
Regulatory
Alternative
1
2
3
4
5
Carbon
Monoxide
(Mg/yr)
3.53
3.80
4.38
5.01
6.20
Nitrogen
Oxides (Mg/yr)
28.23
30.36
35.02
40.11
49.59
Electricity
Usage
(106 Kw-hr/yr)
0.459
0.493
0.569
0.652
0.806
Natural Gas
Usage
(109 Btu/yr)
0.106
0.114
0.131
0.150
0.186
Steam Usage
(109 Btu/yr)
105.85
113.87
131.33
150.41
185.96
7.5 REFERENCES
1. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Hazardous Air Pollutant Emissions
from Process Units in the Synthetic Organic Chemical
Manufacturing Industry -- Background Information for
Proposed Standards Volume 1A, IB, and 1C. Research Triangle
Park, NC. November 1992.
Reference 1. Volume 1A: National Impacts Assessment. p,
3.
5-
7-17
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U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Guideline Series Control of
Volatile Organic Compound Emissions from Industrial
Wastewater. Research Triangle Park, NC. Appendix B. Draft.
September 1992.
Memorandum from Cris Bagley, Radian, to Penny Lassiter,
EPA/CPB, "Development of National Impacts for the Industrial
Wastewater CTG." April 4, 1991.
ICR and Supporting Statement. Review Draft. U.S.
Environmental Protection Agency, Research Triangle Park, NC.
April 1994.
Reference 1, Volume 1A: National Impacts Assessment. p. 5-
10 - 5-18.
Reference 5 with updated values supplied by U.S.
Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research Triangle Park, NC. 1994.
7-18
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8.0 ENHANCED MONITORING
The 1990 Clean Air Act Amendments require that new EPA
regulations include monitoring strategies that incorporate the
concepts of enhanced monitoring. The purpose of enhanced
monitoring is to provide a means for major sources to demonstrate
that the affected facility is in continuous compliance with the
standards. Enhanced monitoring requirements are intended to
ensure that monitoring data can be used both to determine
compliance with each applicable standard and to determine the
existence of enforceable violations.
The preferred implementation of enhanced monitoring is the
use of a continuous emission monitor system (CEMS). However,
there are cases where CEMS are not technically feasible or
economically practical. In those cases, the EPA's approach is
generally to require the continuous monitoring of specified
operating parameters that are established as being directly
related to emission control performance. This chapter discusses
enhanced monitoring as it applies to the NSPS for SOCMI
wastewater.
8.1 ENHANCED MONITORING FOR CONTROL DEVICES
The EPA considered three monitoring options for control
devices: (1) the use of CEMS to measure total VOC; (2) the use
of CEMS for surrogate compounds such as total hydrocarbons (THC)
as surrogate for total VOC; and (3) the continuous monitoring of
control device operating parameters. The first two of these
8-1
-------
options were found not to be reasonable alternatives for this
rule.
Although continuous emission monitors for total VOC are
currently available, they are not universally applicable within
the SOCMI wastewater source category. Existing CEMS for total
VOC operate either by flame ionization detection (FID),
photoionization detection (PID), non-dispersive infrared (NDIR)
absorption, or other detection principles that respond to VOC
levels. In most cases, VOC monitors provide only a measure of
the relative concentration of a mixture of organics rather than
quantification of organic species.1 This characteristic leads to
the use of VOC CEMS as a relative indicator of emissions rather
than as a conventional emissions monitor. VOC CEMS would only
provide a quantitative measure of emissions in situations where
total VOC is represented by a single chemical compound or
compounds that generate equal responses by the monitoring
instrument. Such situations are unlikely at SOCMI process units.
SOCMI wastewaters generally have multiple chemical constituents
at variable concentrations, thus, even CEMS that use gas
chromatography, which are normally not usable if the number of
organic compounds exceeds five, may not be appropriate for this
application.2 In light of these considerations, the
implementation of CEMS to measure VOC emissions were determined
to be unreasonable costly. This conclusion is reinforced by
demonstrations that have shown parametric monitoring to be less
costly than CEMS but equally effective in indicating continuous
compliance. Consequently, owners, or operators that use control
devices such as incinerators or condensers to comply with the
proposed standards may use CEMS where applicable to demonstrate
continuous compliance, if they find it reasonable to do so.
However, parameter monitoring is also allowed.
Temperature is an acceptable parameter to monitor for both
incinerators and condensers. Incinerator monitoring would
-------
measure the combustion zone temperature in thermal incinerators
or the temperature upstream and downstream of the catalyst bed in
catalytic incinerators. Condenser monitoring would involve
temperature monitoring of the vapor exhaust stream.
Because CEMS are generally not applicable for determining
compliance for many SOCMI wastewaters, and because there
generally is a control device parameter such as temperature that
is a suitable indicator of control device performance, and
because temperature monitors are much less costly than CEMS,
parameter monitoring is judged to be the most appropriate means
of demonstrating compliance with the control device standards.
In many cases, such monitoring does not impose any additional
burden on the owner or operator because may operating parameters
are already routinely monitored for other purposes. To
demonstrate continuous compliance, a control device must maintain
parameter values within the ranges that represent compliance.
These ranges are established during an initial performance.
8.2 MONITORING OF WASTEWATER TREATMENT DEVICES
The primary technique by which owners and operators are
expected to comply with the SOCMI wastewater NSPS is by treating
the wastewater with a steam stripper followed by a control
device. Regulatory provisions in the NSPS describe design and
operating characteristics of a steam stripper. These design and
equipment standards require the installation, calibration,
operation, and maintenance of continuous monitors in accordance
with manufacturers specifications. The monitors are required to
continuously record: (1) the mass rate of wastewater entering
the stripper, (2) the mass rate of steam entering the stripper,
and (3) the wastewater column feed temperature. Acceptable
values for these parameters, indicating proper operation of the
treatment device, are established during the initial performance
test or according to design specifications in the regulation.
8-3
-------
These parameters are routinely monitored in the industry to
ensure proper operation of the steam stripper. Therefore,
continuous compliance for a steam stripper is assured without any
additional enhanced monitoring burden on the industry.
8.3 ENHANCED MONITORING OF TANKS
Emission controls for tanks are based on the use of covers,
which is an equipment requirement rather than a performance
standard. In some situations, the use of a fixed roof on a tank
may be adequate and in other cases a floating roof vented to a
control device may be needed. When tanks are vented to an
external control device, enhanced monitoring of the control
device may be required as discussed above. There are, however,
no continuous or enhanced monitoring alternatives for either
fixed or floating roofs. Tank monitoring requirements include
initial and periodic inspections coupled with adequate equipment
maintenance.
8.4 ENHANCED MONITORING OF CONTAINERS
The control of emissions from containers is based on the use
of covers and the use of a submerged fill pipe for container
loading. These control techniques are equipment requirements
rather than performance standards. Consequently, there are no
enhanced monitoring alternatives for containers.
8.5 ENHANCED MONITORING OF CLOSED VENT SYSTEMS
Monitoring requirements for closed vent systems includes an
initial performance test to ensure that the system is maintained
under negative pressure. This is followed by monthly inspections
to confirm that all openings in the system that were closed
during the performance test remain closed.
To ensure continuous compliance with the NSPS requirements
for no detectable leaks, closed vent systems are monitored
initially with a portable hydrocarbon detector. After that,
8-4
-------
monitoring consists of annual visual inspections of ductwork,
piping, covers, and connections for evidence of visible defects.
There are also requirements for prompt repair of any defects
found.
If the closed vent system includes a bypass line, a flow
indicator must be installed, calibrated, maintained, and operated
in accordance with manufacturer's instructions to provide a
record of emission point gas stream flow at least once every 15
minutes. Alternatively, bypass lines may be sealed is a closed
position and visually inspected to ensure that they are
maintained in the closed condition.
8.6 REFERENCES
1. Performance specification 101 - Performance Specifications
for Volatile Organic Compound Continuous Emission Monitoring
Systems in Stationary Sources, 58 FR 54693, October 22,
1993.
2. Performance Specification 102 - Performance Specification
for Gas Chromatographic Continuous Emission Monitoring
Systems in Stationary Sources, 58 FR 54694, October 22,
1993.
5-5
-------
9.0 CONTROL COST ESTIMATES
This chapter presents a brief discussion of the procedures
used to estimate the nationwide implementation costs of an NSPS
for SOCMI secondary sources. Cost impacts include total capital
costs, total annual costs, and average cost effectiveness (i.e.,
the cost per megagram of pollutant removed). Average cost
effectiveness is computed by dividing the national annual cost by
the national emission reductions relative to baseline. Cost
estimates for controlling emissions from wastewater operations
are based on facility-wide control because this is general
industry practice. The costs of wastewater treatment are based
on the use of steam strippers. Steam stripping systems contain
several components including feed tank, heat exchanger, steam
stripping column, condenser, overheads receiver, and an emission
control device. As has been discussed elsewhere in this BID, the
impacts of the NSPS are calculated as an increment to the impacts
calculated for the HON and steam stripping costs are calculated
as the difference between the cost of a steam stripper with the
capacity to handle the wastewater streams that require control
under the HON and a stripper with the higher capacity needed to
treat the combined wastewater streams that require treatment
under either the HON or the NSPS. Designing and costing steam
strippers to handle multiple wastewater streams at a facility
provides an economy of scale compared to the control of
individual wastewater streams. A brief summary of the approach
to designing and costing a steam stripping system is presented
9-1
-------
here. Details of the procedures can be found in the BID for the
HON.1
9.1 STEAM STRIPPER DESIGN
Steam stripping systems are designed in several different
configurations depending on a number of site-specific
circumstances. However, the components of most systems are
fairly uniform and include a feed tank, a feed/bottoms heat
exchanger, steam stripping column, vent lines, condenser system,
and ancillary pumps. The following paragraphs present a brief
description of the components of a steam stripping system.
Additional design details are available in the BID for the HON.2
9.1.1 Feed tank
A controlled sewer system or hard piping between the point
of generation and the feed tank can be used to prevent air
emissions from wastewater prior to a steam stripping operation.
The feed tank, which is covered and vented to a control device,
serves to collect and condition wastewater for conveyance to the
steam stripper. Feed tanks are sized to provide the retention
time needed to allow for variations in wastewater stream flow
rate and to allow for any needed conditioning of the wastewater.
Feed tanks are also used for phase separation when the waste
stream consists of both organic and aqueous phases and in these
cases must provide adequate retention time for phase separation
to occur. Solids tend to settle out in the feed tank and are
removed by periodic cleaning.
9.1.2 Steam stripper
From the feed tank, wastewater is pumped through the
feed/bottoms heat exchanger where it is preheated by the heated
effluent stream and then pumped into the top of the steam
stripping column. Steam is sparged into the stripper at the
bottom of the column. Uncondensed steam and vaporized organics
flow out the top of the column and the effluent leaving the
bottom is pumped through the feed/bottoms heat exchanger to heat
9-2
-------
the feed stream. The cooled effluent may be routed to a
wastewater treatment plant or discharged to a permitted outfall
or a publicly owned treatment works (POTW).
9.1.3 Emissions control
Steam stripper systems include vent lines to transport
gaseous organics, water vapor, and noncondensables between system
elements such as the stripper column and recovery device,
recovery device and feed tank, and feed tank and combustion
device. All vent lines are controlled by either a combustion
device or product recovery device. Combustion device
alternatives include thermal or catalytic incinerators, flares,
boilers, or process heaters. Product recovery devices include
condensers, carbon adsorbers, or absorbers. Openings in the
steam stripper system for pressure relief, venting, or
maintenance access are sealed unless in use.
9.1.4 Product recovery
Product recovery from a steam stripper is normally achieved
by a condenser system. In some cases, a secondary, refrigerated
condenser is needed to increase recovery efficiency. Recovered
organics are either recycled to the process or combusted in an
incinerator, boiler, or process heater. Noncondensibles in the
stripper overhead are routed to a control device such as a carbon
adsorber, boiler, process heater, or incinerator.
9.1.5 Stripper efficiency
The efficiency with which a steam stripper removes organic
compounds from a wastewater stream is highly dependent on the
volatility of the individual organic compounds and may range from
0 to more than 99 percent. Removal performance also depends on
the degree of contact between the steam and wastewater. The
degree of contact is determined by the design and operating
parameters of the system such as: (1) the height and diameter of
the column; (2) the selection of either trays or packing as the
contacting media; and (3) operating parameters such as steam-to-
9-3
-------
feed ratio, column temperature, and wastewater pH. Removal
efficiency of a steam stripper is lower for wastewater streams
with organic concentrations below a threshold of about 50 to 100
ppm. Above that threshold, efficiency is relatively constant but
declines rapidly below the threshold. Steam stripper efficiency
is higher for chlorinated compounds than for non-chlorinated
compounds.
9.1.6 Applicability
Steam stripping is most applicable to treating wastewaters
with organic compounds that are highly volatile and have a low
solubility in water. The VOC's that have low volatility tend to
volatilize less readily and thus are not easily stripped out of
the wastewater by steam. Similarly, VOC's that are very soluble
in water tend to remain in the wastewater and also are not easily
stripped out by steam. Oil, grease, and solids content as well
as pH of a wastewater stream also affect the applicability of
steam stripping to a particular wastewater stream. High levels
of oil, grease, and solids often create operational problems for
the system and high or low pH may produce equipment corrosion.
Problems such as these can often be avoided by modifications to
the equipment design or by wastewater conditioning prior to
treatment.
9.2 STEAM STRIPPER COSTS
This section presents a brief overview of the approach to
estimating steam stripper costs. Additional details of the
approach are available in the BID for the HON.3
9.2.1 Design considerations
A primary determinant of steam stripper capital costs is the
size of the stripper which is a function of the design throughput
of the system and the design removal efficiency. Column diameter
is a function of design throughput and column height is a
function of design removal efficiency. Steam stripper annual
costs are a function of the annual steam requirement which is a
9-4
-------
function of both the steam-to-feed ratio and the annual
wastewater throughput. For highly corrosive wastewater streams,
capital costs may be increased because of the need to fabricate
the system using stainless steel rather than carbon steel.
9.2.2 Capital costs
Total capital investment is calculated as the sum of the
purchased equipment cost, direct installation costs, and indirect
installation costs. Purchased equipment costs is comprised of
the cost of basic equipment, auxiliary piping and equipment,
instrumentation, freight, and taxes. Direct installation costs
include such elements as electrical wiring, insulation, equipment
support and erection, and equipment painting. Indirect
installation costs include engineering, construction and field
expense, construction fee, start-up and testing, and contingency.
Total capital investment may also include costs for buildings,
off-site facilities, land, working capital, and yard
improvements. Equations for estimating the capital costs of the
various components of a steam stripping system and for estimating
the total capital investment of a system are described in the BID
for the HON.
9.2.3 Annual costs
Total annual cost is the total of all costs incurred to
operate the steam stripper system over an entire year and include
both direct and indirect charges. Direct annual costs consist of
normal operating expenses such as utilities, labor and
maintenance activities. Indirect operating costs include
overhead and capital recovery, which is calculated based on a
projected operating life of the equipment and anticipated
interest rates. Where organic materials are recovered from the
steam stripping system and a benefit is derived, total annual
costs are adjusted downward by the value of the recovered
materials. If no cost-effective use can be made for the
recovered organics, an additional disposal cost may be incurred.
9-5
-------
Factors for estimating direct and indirect annual costs and the
capital recovery factor are presented in the BID for the HON.
9.3 REFERENCES
1. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Hazardous Air Pollutant Emissions
from Process Units in the Synthetic Organic Chemical
Manufacturing Industry—Background Information for Proposed
Standards Volume 1A, Ib, and 1C. Research Triangle Park,
NC. November 1992.
2. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Hazardous Air Pollutant Emissions
from Process Units in the Synthetic Organic Chemical
Manufacturing Industry—Background Information for Proposed
Standards Volume IB Control Technologies. Research triangle
Park, NC. p. 2-33 - 2-42. November 1992.
3. Reference 2. p. 3-31 - 3-40.
4. Reference 2. p. 3-33 - 3-34.
5. Reference 2. p. 3-38 - 3-40.
9-6
-------
Appendix A
List of SOCMI Chemicals
-------
-------
Appendix A
List of SOCMI Chemicals
Chemical Name3
CAS Number
Acenaphthene
Acetal
Acetaldehyde
Acetaldol
Acetamide
Acetanilide
Acetic acid
Acetic anhydride
Acetoacetanilide
Acetone
Acetone cyanohydrin
Acetonitrile
Acetophenone
Acetyl chloride
Acetylene
Acetylene tetrabromide
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Adipic acid
Adiponitrile
Alcohols, C-ll or lower, mixtures
Alcohols, C-ll or higher, mixtures
Alizarin
Alkyl anthraquinones
Alkyl naphthalene sulfonates
Alkyl naphthalenes
83329
105577
75070
107891
60355
103844
64197
108247
102012
67641
75865
75058
98862
75365
74862
107028
79061
79107
107131
124049
111693
72480
008
A-3
-------
Chemical Name3
CAS Number
Allyl alcohol
Allyl bromide
Allyl chloride
Allyl cyanide
Aluminum acetate
Aluminum formates
Aminobenzoic acid (p-)
Aminoethylethanolamine
Aminophenol sulfonic acid
Aminophenol (p-)
Amino 3,4,6-trchlorophenol
Ammonium acetate
Ammonium thiocyanate
Amylene
Amylenes, mixed
Amyl acetates
Amyl alcohol (n-)
Amyl alcohol (tert-)
Amyl alcohols (mixed)
Amyl chloride (n-)
Amyl chlorides (mixed)
Amyl ether
Amyl mercaptans
Amyl phenol
Amylamines
Aniline
Aniline hydrochloride
Anisidine (o-)
Anisidine (p-)
107186
107051
109751
1321115
111411
0010
123308
123308
513359
628637,
123922
71410
71410
71410
543599
110667
1322061
110587
62533
142041
90040
29191524
A-4
-------
Chemical Name3
CAS Number
Anisole
Anthracene
Anthranilic acid
Anthraquinone
Azobenzene
Barium acetate
Benzaldehyde
Benzamide
Benzene
Benzenedisulfonic acid
Benzenesulfonic acid
Benzenesulfonic acid C10_16-alkyl
derivatives, sodium salts
Benzidine
Benzil
Benzilic acid
Benzoguanamine
Benzole acid
Benzoin
Benzonitrile
Benzophenone
Benzotrichloride
Benzoyl chloride
Benzoyl peroxide
Benzyl acetate
Benzyl alcohol
Benzyl benzoate
Benzyl chloride
Benzyl dichloride
Benzylamine
100663
120127
118923
84651
103333
100527
55210
71432
98486
98113
68081812
134816
76937
65850
119539
100470
119619
98077
98884
140114
100516
120514
100447
98873
100469
A-5
-------
Chemical Name3
CAS Number
Benzylideneacetone
Biphenyl
Bisphenol A
Bis(Chloromethyl)Ether
Brometone
Bromobenzene
Bromoform
Bromonaphthalene
Butadiene (1,3-)
Butadiene and butene fractions
Butane
Butanes, mixed
Butanediol (1,4-)
Butenes, mixed
1-Butene
2-Butene
Butyl acetate (n-)
Butyl acetate (sec-)
Butyl acetate (tert-)
Butyl acrylate (n-)
Butyl alcohol (n-)
Butyl alcohol (sec-)
Butyl alcohol (tert-)
Butyl benzoate
Butyl chloride (tert-)
Butyl hydroperoxide (tert-)
Butyl mercaptan (n-)
Butyl mercaptan (tert-)
Butyl methacrylate (n-)
Butyl methacrylate (tert-)
92524
80057
542881
108861
75252
27497514
106990
106978
110634
106989
25167673
123864
141322
71363
78922
75650
75912
A-6
-------
Chemical Name3
CAS Number
Butyl phenol (tert-)
Butyl toluene (tert-)
Butylamine (n-)
Butylamine (s-)
Butylamine (t-)
Butylbenzene (tert-)
Butylbenzoic acid (p-tert-]
Butylbenzyl phthalate
Butylene glycol (1,3-)
Butylenes (n-)
2-Butyne-l,4-diol
Butyraldehyde (n-)
Butyric acid (n-)
Butyric anhydride (n-)
Butyrolacetone
Butyronitrile
Calcium acetate
Calcium propionate
Caproic acid
Caprolactam
Carbaryl
Carbazole
Carbon disulfide
Carbon tetrabromide
Carbon tetrachloride
Carbon tetrafluoride
Cellulose acetate
Chloral
Chloranil
Chloroacetic acid
109739
13952846
75649
98737
85867
107880
110656
123728
107926
106310
96480
109740
105602
63252
86748
75150
558134
56235
75730
9004357
75876
79118
A-7
-------
Chemical Name3
CAS Number
Chloroacetophenone (2-\
Chloroaniline (m-)
Chloroaniline (o-)
Chloroaniline (p-)
Chlorobenzaldehyde
Chlorobenzene
Chlorobenzoic acid
Chlorobenzotrichloride (o-]
Chlorobenzotrichloride (p-]
Chlorobenzoyl chloride (o-)
Chlorobenzoyl chloride (p-)
2-Chloro-l,3-butadiene (Chloroprene)
Chlorodifluoroethane
Chiorodifluoromethane
2-Chloro-4-(ethylamino)-6-
(isopropylamino)-S-triazine
Chlorofluorocarbons
Chloroform
Chlorohydrin
Chloronaphthalene
Chloronitrobenzene (m-)
Chloronitrobenzene (o-)
Chloronitrobenzene (p-)
Chlorophenol (m-)
532274
108429
95512
106478
35913098
108907
118912,
535808,
74113
2136814,
2136892,
5216251
2136814,
2136892,
5216251
1321035
1321035
126998
25497294
75456
1912249
67663
25586430
121733
88733
100005
108430
A-i
-------
Chemical Name3
CAS Number
Chlorophenol (o-)
Chlorophenol (p-)
Chlorosulfonic acid
Chlorotoluene (m-)
Chlorotoluene (o-)
Chlorotoluene (p-)
Chlorotrifluoroethylene
Chlorotrifluoromethane
Choline chloride
Chrysene
Cinnamic acid
Citric acid
Cobalt acetate
Copper acetate
Cresol and cresylic acid (m-)
Cresol and cresylic acid (o-)
Cresol and cresylic acid (p-)
Cresols and cresylic acids (mixed)
Crotonaldehyde
Crotonic acid
Cumene
Cumene hydroperoxide
Cyanamide
Cyanoacetic acid
Cyanoformamide
Cyanogen chloride
Cyanuric acid
Cyanuric chloride
Cyclohexane
Cyclohexane, oxidized
95578
106489
7790945
108418
95498
106434
75729
218019
77929
108394
95487
106445
1319773
4170300
3724650
98828
80159
372098
506774
108805
108770
110827
68512152
A-9
-------
Chemical Name3
CAS Number
Cyclohexanol
Cyclohexanone
Cyclohexanone oxime
Cyclohexene
Cyclohexylamine
Cyclooctadiene
Cyclooctadiene (1,3-)
Cyclooctadiene (1,5-)
Cyclopentadiene (1,3-)
Cyclopropane
Decahydronaphthalene
Decanol
Decyl alcohol
Diacetone alcohol
Diacetoxy-2-Butene (1,4-)
Diallyl isophthalate
Dially phthalate
Diaminobenzoic acids
Diaminophenol hydrochloride
Dibromomethane
Dibutanized aromatic concentrate
Dibutoxyethyl phthalate
Dichloroaniline (mixed isomers)
Dichlorobenzene (p-)
Dichlorobenzene (m-)
Dichlorobenzene (o-)
Dichlorobenzidine (3,3'-)
1,4-Dichlorobutene
3,4-Dichloro-l-butene
Dichloro-2-butenes
108930
108941
100641
110838
108918
29965977
111784
111784
75194
91178
112301
123422
0012
27576041
137097
74953
27134276
106467
541731
95501
91941
110576
64037543
A-10
-------
Chemical Name3
CAS Number
Dichlorodifluoromethane
Dichlorodimethylsilane
Dichloroethane (1,2-) (Ethylene dichloride) (EDC)
Dichloroethyl ether (bis(2-chloroethyl)ether)
Dichloroethylene (1,2-)
Dichlorofluoromethane
Dichlorohydrin (a-)
Dichloromethyl ether
Dichloronitrobenzenes
Dichloropentanes
Dichlorophenol (2,4-)
Dichloropropane (1,1-)
Dichloropropene (1,3-)
Dichloropropene/dichloropropane (mixed)
Dichlorotetrafluoroethane
Dichloro-1-butene (3,4-)
Dichloro-2-butene (1,4-)
Dicyanidiamide
Dicyclohexylamine
Dicyclopentadiene
Diethanolamine (2,2*-Iminodiethanol)
Diethyl phthalate
Diethyl sulfate
Diethylamine
Diethylaniline (2,6-)
Diethylaniline (N,N-)
Diethylbenzene
Diethylene glycol
Diethylene glycol dibutyl ether
Diethylene glycol diethyl ether
75718
107062
111444
540590
75434
96231
120832
542756
1320372
760236
764410
101837
111422
64675
109897
579668
25340174
111466
112732
112367
A-11
-------
Chemical Name3
CAS Number
Diethylene glycol dimethyl ether
Diethylene glycol monobutyl ether acetate
Diethylene glycol monobutyl ether
Diethylene glycol monoethyl ether acetate
Diethylene glycol monoethyl ether
Diethylene glycol monohexyl ether
Diethylene glycol monomethyl ether acetate
Diethylene glycol monomethyl ether
Difluoroethane (1,1-)
Di-n-heptyl-n-nonyl undecyl phthalate
Dihydroxybenzoic acid (Resorcylic acid)
Diisobutylene
Diisodecyl phthalate
Diisononyl phthalate
Diisooctyl phthalate
Diisopropyl amine
Diketene
Dimethyl acetamide
Dimethylbenzidine (3,3'-)
Dimethyl ether
Dimethylformamide (N,N-)
Dimethylhydrazine (1,1-)
Dimethyl phthalate
Dimethyl sulfate
Dimethyl sulfide
Dimethyl sulfoxide
Dimethyl terephthalate
Dimethylamine
Dimethylaminoethanol (2-)
Dimethylaniline (N,N)
111966
124174
112345
112152
111900
112594
629389
111773
75376
27138574
25167708
26761400
28553120
27554263
674828
119937
115106
68122
57147
77781
75183
67685
120616
124403
108010
121697
A-12
-------
Chemical Name3
CAS Number
Dinitrobenzenes (NOS)C
Dinitrobenzoic acid (3,5-)
Dinitrophenol (2,4-)
Dinitrotoluene (2,3-)
Dinitrotoluene (2,4-)
Dinitrotoluene (2,6-)
Dinitrotoluene (3,4-)
Dioctyl phthalate
Dioxane (1,4-) (1,4-Diethyleneoxide)
Dioxolane (1,3-)
Diphenyl methane
Diphenyl oxide
Diphenyl thiourea
Diphenylamine
Dipropylene glycol
Di(2-methoxyethyl) phthalate
Di-o-tolyguanidine
Dodecandedioic acid
Dodecene (branched)
Dodecene (n-)
Dodecyl benzene (branched)
Dodecylbenzene, nonlinear
Dodecylbenzene sulfonic acid
Dodecylbenzene sulfonic acid, sodium salt
Dodecylmercaptan (branched)
Dodecyl phenol (branched)
Dodecylaniline
Dodecylbenzene (n-)
Dodecylphenol
Epichlorohydrin (l-chloro-2,3-epoxypropane)
25154545
99343
51285
121142
606202
117817
123911
646060
101815
101848
102089
122394
110985
97392
693232
25378227
123013
27176870
25155300
121158585
28675174
121013
27193868
106898
A-13
-------
Chemical Name3
CAS Number
Ethane
Ethanol
Ethanolamine
Ethyl acetate
Ethyl acetoacetate
Ethyl acrylate
Ethylbenzene
Ethyl bromide
Ethyl chloride (Chloroethane)
Ethyl chloroacetate
Ethyl cyanide
Ethyl ether
Ethyl hexanol (2-)
Ethyl mercaptan
Ethyl orthoformate
Ethyl oxalate
Ethyl sodium oxalacetate
Ethylamine
Ethylaniline (n-)
Ethylaniline (o-)
Ethylcellulose
Ethylcyanoacetate
Ethylene
Ethylene carbonate
Ethylene chlorohydrin
Ethylene dibromide (Dibromoethane)
Ethylene dichloride
Ethylene glycol
Ethylene glycol diacetate
Ethylene glycol dibutyl ether
64175
141435
141786
141979
140885
100414
74964
75003
105395
107120
60297
104767
122510
95921
41892711
75047
103695
578541
9004573
105566
74851
96491
107073
106934
107062
107211
111557
112481
A-14
-------
Chemical Name3
CAS Number
Ethylene glycol diethyl ether (1,2-diethoxyethaneJ
Ethylene glycol dimethyl ether
Ethylene glycol monoacetate
Ethylene glycol monobutyl ether acetate
Ethylene glycol monobutyl ether
Ethylene glycol monoethyl ether acetate
Ethylene glycol monoethyl ether
Ethylene glycol monohexyl ether
Ethylene glycol monomethyl ether acetate
Ethylene glycol monomethyl ether
Ethylene glycol monooctyl ether
Ethylene glycol monophenyl ether
Ethylene glycol monopropyl ether
Ethylene oxide
Ethylenediamine
Ethylenediamine tetraacetic acid
Ethylenimine (Aziridine)
2-Ethylhexanol
Ethylhexanoic acid
Ethylhexyl acrylate (2-isomer)
2-Ethylhexyl alcohol
(2-Ethylhexyl) amine
Ethylhexyl succinate (2-)
Ethylmethylbenzene
6-Ethyl-l,2,3,4-tetrahydro-9, 10-
antracenedione
Fluoranthene
Formaldehyde
Formamide
Formic acid
629141
110714
542596
112072
111762
111159
110805
112254
110496
109864
002
122996
2807309
75218
107153
60004
151564
104767
103117
104767
104756
25550145
15547178
206440
50000
75127
64186
A-15
-------
Chemical Name3
CAS Number
Fumaric acid
Furfural
Glutaraldehyde
Glyceraldehyde
Glycerol
Glycerol dichlorohydrin
Glycerol tri(polyoxypropylene)ether
Glycidol
Glycine
Glycol ethers
Glyoxal
Guanidine
Guanidine nitrate
n-Heptane
Heptenes
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexadecyl alcohol
Hexadecyl chloride
Hexadiene (1,4-)
Hexamethylenediamine
Hexamethylene diamine adipate
Hexamethylene glycol
Hexamethylenetetramine
Hexane
Hexanetriol (1,2,6-)
2-Hexenedinitrile
3-Hexenedinitrile
110178
98011
111308
367475
56815
26545737
25791962
56406
107222
142825
118741
87683
67721
36653824
592450
124094
3323533
629118
100970
110543
106694
13042029
1119853
A-16
-------
Chemical Name3
CAS Number
Hexyl alcohol
Hexylene glycol
Higher glycols
Hydrogen cyanide
Hydroquinone
Hydroxyadipaldehyde
Hydroxybenzoic acid (p-)
Iminodiethanol (2,2-)
Isoamyl alcohol
Isoamyl chloride (mixed)
Isoamylene
Isobutane
Isobutanol
Isobutyl acetate
Isobutyl acrylate
Isobutyl alcohol
Isobutyl methacrylate
Isobutyl vinyl ether
Isobutylene
Isobutyraldehyde
Isobutyric acid
Isodecanol
Isodecyl alcohol
Isohexyldecyl alcohol
Isononyl alcohol
Isooctyl alcohol
Isopentane
Isophorone
Isophorone nitrile
Isophthalic acid
74908
123319
141311
99967
26760645
75285
78831
110190
106638
115117
78842
79312
25339177
25339177
26952216
78784
78591
0017
121915
A-17
-------
Chemical Name3
CAS Number
Isoprene
Isopropanol
Isopropyl acetate
Isopropyl chloride
Isopropyl ether
Isopropylamine
Isopropylphenol
Ketene
Lactic acid
Lauryl dimethylamine oxide
Lead acetate
Lead phthalate
Lead subacetate
Linear alcohols, ethoxylated, mixed
Linear alcohols, ethoxylated and sulfated, sodium
salt, mixed
Linear alcohols, sulfated, sodium salt, mixed
Linear alkylbenzene
Linear alkyl sulfonate
Magnesium acetate
Maleic acid
Maleic anhydride
Maleic hydrazide
Malic acid
Manganese acetate
Melamine
Mercuric acetate
Mesityl oxide
Metanilic acid
78795
67630
108214
75296
75310
25168063
463514
123013
142723
110167
108316
123331
6915157
108781
141797
121471
A-18
-------
Chemical Name3
CAS Number
Methacrylic acid
Methacrylonitrile
Methallyl alcohol
Methallyl chloride
Methane
Methanol
Methionine
Methyl acetate
Methyl acetoacetate
Methyl acrylate
Methyl anthranilate
Methyl bromide (Bromomethane)
Methyl butenols
Methyl butynol
Methyl chloride (Chloromethane)
Methyl ethyl ketone (2-butanone)
Methyl formate
Methyl hydrazine
Methyl iodide
Methyl isobutyl carbinol
Methyl isobutyl ketone (Hexone)
Methyl isocyanate
Methyl mercaptan
Methyl methacrylate
Methyl phenyl carbinol
Methyl salicylate
Methyl tert-butyl ether
Methylamine
Methylaniline (N-)
ar-Methylbenzenediamine
79414
126987
563473
67561
63683
79209
105453
96333
74839
37365712
74873
78933
107313
60344
74884
108112
108101
624839
74931
80626
98851
1634044
74895
100618
25376458
A-19
-------
Chemical Name3
CAS Number
Methylbutanol (2-)
Methylcyclohexane
Methylcyclohexanol
Methylcyclohexanone
Methylene chloride (Dichloromethane)
Methylene dianiline (4,4'-isomer)
Methylene diphenyl diisocyanate (4,4*
Methylionones (a-)
Methylnaphthalene (1-)
Methylnaphthalene (2-)
Methylpentane (2-)
Methylpentynol
l-Methyl-2-pyrrolidone
Methylstyrene (a-)
Methyl-1-pentene (2-)
Monomethylhydrazine
Morpholine
Naphthalene
Naphthalene sulfonic acid (a-)
Naphthalene sulfonic acid (b-)
Naphthenic acids
Naphthol (a-)
Naphthol (b-)
Naphtholsulfonic acid (1-)
Naphthylamine sulfonic acid (1,4-)
Naphthylamine sulfonic acid (2,1-)
Naphthylamine (1-)
Naphthylamine (2-)
1-Naphthyl-N-methylcarbamate
Neohexane
(MDi;
108872
25639423
1331222
75092
101779
101688
79696
107835
77758
872504
98839
91203
85472
120183
90153
135193
567180
84866
81163
134327
91598
A-20
-------
Chemical Name3
CAS Number
Neopentanoic acid
Neopentyl glycol
Nickel formate
Nitriloacetic acid
Nitrilotriacetic acid
Nitroaniline (m-)
Nitroaniline (o-)
Nitroaniline (p-)
Nitroanisole (o-)
Nitroanisole (p-)
Nitrobenzene
Nitrobenzoic acid (m-)
Nitrobenzoic acid (o-)
Nitrobenzoic acid (p-)
Nitrobenzoyl chloride (p-]
Nitroethane
Nitroguanidine
Nitromethane
Nitronaphthalene (1-)
Nitrophenol (p-)
Nitrophenol (o-)
Nitropropane (1-)
Nitropropane (2-)
Nitrotoluene (all isomers!
Nitrotoluene (o-)
Nitrotoluene (m-)
Nitrotoluene (p-)
Nitroxylene
Nonene
Nonyl alcohol
75989
99092
88744
100016
91236
100174
98953
27178832
27178832
27178832
79243
75525
86577
100027
88755
25322014
79469
1321126
88722
99081
99990
25168041
27215958
1430808
A-21
-------
Chemical Name3
CAS Number
Nonylbenzene (branched)
Nonylphenol
Nonylphenol (branched)
Nonylphenol, ethoxylated
N-Vinyl-2-pyrrol!dine
Octane
Octene-1
Octylamine (tert-)
Octylphenol
Oil-soluble petroleum sulfonate calcium salt
Oil-soluble petroleum sulfonate sodium salt
Oxalic acid
Oxamide
Oxo chemicals
Paraformaldehyde
Paraldehyde
Pentachlorophenol
Pentaerythritol
Pentaerythritol tetranitrate
Pentane
Pentanethiol
Pentanol (2-)
Pentanol (3-)
Pentene (1-)
Pentene (2-)
Pentenes, mixed
3-Pentenenitrile
Peracetic acid
Perchloromethyl mercaptan
Phenacetin
1081772
25154523
9016459
111660
27193288
30525894
123637
87865
115775
109660
115775
109671
109671
109671
4635874
79210
594423
A-22
-------
Chemical Name3
CAS Number
Phenanthrene
Phenetidine (o-)
Phenetidine (p-)
Phenol
Phenolphthalein
Phenolsulfonic acids (all isomers)
Phenyl anthranilic acid (all isomers!
Phenylenediamine (m-)
Phenylenediamine (o-)
Phenylenediamine (p-)
1-Phenyl ethyl hydroperoxide
Phenylmethylpyrazolone
Phenylpropane
Phloroglucinol
Phosgene
Phthalic acid
Phthalic anhydride
Phthalimide
Phthalonitrile
Picoline (a-)
Picoline (b-)
Picramic acid
Picric acid
Piperazine
Piperidine
Piperylene
Polybutenes
Polyethylene glycol
Polypropylene glycol
85018
94702
156434
108952
77098
1333397
91407
106503
3071327
103651
108736
75445
88993
85449
85416
91156
108996
110850
9003296,
25036297
25322683
25322694
A-23
-------
Chemical Name3
CAS Number
Potassium acetate
Propane
n-Propanol
Propiolactone (beta-)
Propionaldehyde
Propionic acid
Propyl acetate (n-)
Propyl alcohol (n-)
Propyl chloride
Propylamine
Propylene
Propylene carbonate
Propylene chlorohydrin
Propylene dichloride (1,2-dichloropropane)
Propylene glycol
Propylene glycol monomethyl ether
Propylene oxide
Pseudocumene
Pseudocumidine
Pyrene
Pyridine
Pyrrolidone (2-)
p-tert-Butyl toluene
Quinone
Resorcinol
Salicylic acid
Sebacic acid
Sodium acetate
Sodium benzoate
Sodium carboxymethyl cellulose
74986
57578
123386
79094
71238
540545
107108
115071
108327
127004
78875
57556
107982
75569
129000
110861
98511
106514
108463
69727
127093
532321
9004324
A-24
-------
Chemical Name3
CAS Number
Sodium chloroacetate
Sodium cyanide
Sodium dodecyl benzene sulfonate
Sodium formate
Sodium methoxide
Sodium oxalate
Sodium phenate
Sodium propionate
Sorbic acid
Sorbitol
Stilbene
Styrene
Succinic acid
Succinonitrile
Sulfanilic acid
Sulfolane
Synthesis gas
Tannic acid
Tartaric acid
Terephthalic acid
Teraphthaloyl chloride
Tetrabromophthalic anhydride
Tetrachlorobenzene (1,2,3,5-)
Tetrachlorobenzene (1,2,4,5-)
Tetrachloroethane (1,1,2,2-)
Tetrachloroethylene (Perchloroethylene)
Tetrachlorophthalic anhydride
Tetraethyl lead
Tetraethylene glycol
Tetraethylenepentamine
3926623
143339
141537
124414
139026
110441
50704
588590
100425
110156
110612
121573
126330
1401554
526830
100210
632791
95943
79345
127184
117088
78002
112607
112572
A-25
-------
Chemical Name3
CAS Number
Tetrafluoroethylene
Tetrahydrofuran 109999
Tetrahydronapthalene 119642
Tetrahydrophthalic anhydride 85438
Tetramethylenediamine 110601
Tetra (methyl-ethyl) lead
Tetramethylethylenediamine 110189
Tetramethyllead 75741
Thiocarbanilide 102089
Thiourea
Tolidines
Toluene 108883
Toluene 2,4 diamine 95807
Toluene 2,4 diisocyanate 584849
Toluene diisocyanates (mixture) 26471625
Toluene sulfonamides (o- and p-) 1333079
Toluene sulfonic acids 104154
Toluenesulfonyl chloride 98599
Toluidine (o-) 95534
Tribromomethane 75252
Trichloroacetic acid
Trichloroaniline (2,4,6-) 634935
Trichlorobenzene (1,2,3-) 87616
Trichlorobenzene (1,2,4-) 120821
Trichlorobenzene (1,3,5-) 108703
Trichloroethane (1,1,1-) 71556
Trichloroethane (1,1,2-) (Vinyl trichloride) 79005
Trichloroethylene 79016
Trichlorofluoromethane 75694
Trichlorophenol (2,4,5-) 95954
A-26
-------
Chemical Name3
CAS Number
Trichloropropane (1,2,3-)
(1,1,2-) Trichloro (1,2,2-) trifluoroethane
Tricresyl phosphate
Tridecyl alcohol
Tridecyl mercaptan
Triethanolamine
Triethylamine
Triethylene glycol
Triethylene glycol dimethyl ether
Triethylene glycol monoethyl ether
Triethylene glycol monomethyl ether
Triisobutylene
Trimellitic anhydride
Trimethyl pentanol
Trimethylamine
Trimethylcyclohexanol
Trimethylcyclohexanone
Trimethylcyclohexylamine
Trimethylolpropane
Trimethylpentane (2,2,4-)
Trimethyl-1,3-pentanediol (2,2,4-)
Tripropylene glycol
Urea
Vinyl acetate
Vinyl chloride (Chloroethylene)
Vinyl toluene
Vinylcyclohexene (4-)
Vinylidene chloride (1,1-dichloroethylene)
Vinyl(N-)-pyrrolidone(2-)
Vinylpyridine
96184
76131
102716
121448
112276
112492
112505
112356
7756947
75503
933482
2408379
34216347
77996
540841
24800440
57136
108054
75014
25013154
100403
75354
88120
A-27
-------
Chemical Name3
CAS Number
Xanthates
Xylene sulfonic acid
Xylenes (NOS)C
Xylene (m-)
Xylene (o-)
Xylene (p-)
Xylenols (Mixed)
Xylenol (2,3-)
Xylenol (2,4-)
Xylenol (2,5-)
Xylenol (2,6-)
Xylenol (3,4-)
Xylenol (3,5-)
Xylidene
Xylidene (2,3-)
Xylidene (2,4-)
Xylidene (2,5-)
Xylidene (2,6-)
Xylidene (3,4-)
Xylidene (3,5-)
Zinc acetate
140896
25321419
1330207
108383
95476
106423
1300716
1300716
1300716
1300716
1300716
1300716
1300716
1300738
1300738
1300738
1300738
1300738
1300738
1300738
alsomer means all structural arrangements for the same
number of atoms of each element and does not mean salts,
esters, or derivatives.
Number = Chemical Abstract Service number.
CNOS = not otherwise specified.
A-28
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