United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-453/R-01-008 tX
September 2001
Air
& EPA
Background Information Document:
National Emission Standards for
Hazardous Air Pollutants (NESHAP)
for the Friction Materials
Manufacturing Industry
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EPA-453/R-01-008
Background Information Document
National Emission Standards For
Hazardous Air Pollutants (NESHAP)
for the Friction Materials
Manufacturing Industry
U.S. Environmental Protection Agencr
J2 Region 5, Library (Pi- 12J)
^ 77 West Jackson Boulevard, 12th Floor
o, Chicago, IL 60604-3590
Emission Standards Division
U. S. Environmental Protection Agency
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
September 2001
-------
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
ofcthis report are available through the Library Services Office (MD-35), U. S. Environmental
Protection Agency, Research Triangle Pirk, NC 27711. (919) 541-2777, or from National
Technical Information Services, 5285 Port Royal Road, Springfield, VA 22161, (703) 487-4650.
t.
11
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Table of Contents
'Jaee
LISTOFFIGURES vi
LISTOFTABLES vii
LIST OF ACRONYMS AND UNITS OFMEASURE viii
1.0 INTRODUCTION 1-1
1.1 Statutory Basis 1-1
1.2 Source Category Listing -.1-3
1.3 References . . 1-4
t
2.0 FRICTION MATERIALS MANUFACTURING SOURCE CATEGORY 2-1
2.1 Industry Profile 2-1
2.1.1 Data Gathering 2-2
2.1.2 Industry Overview 2-3
2.1.3 Major Sources 2-5
2.1.4 Source Types Not Regulated 2-6
2.1.5 SIC and NAICS Codes 2-7
2.1.6 Small Businesses 2-7
2.1.7 Markets 2-9
2.2 Resin-Based Friction Materials Manufacturing Process 2-10
2.2.1 Raw Material Preparation 2-13
2.2.2 Forming 2-14
2.2.3 Curing 2-14
2.2.4 Assembling and Finishing 2-15
2.3 Characterization of HAP Emissions from Resin-Based Friction Materials
Manufacturing Emission Units 2-15
2.4 Emission Test Data 2-17
2.5 Existing State Regulations 2-17
2.6 References 2-18
3.0 EMISSION CONTROL TECHNIQUES 3-1
3.1 Condensers 3-2
3.1.1 Factors Affecting Performance 3-3
3.1.2 Control Efficiency 3-4
3.1.3 Current Monitoring Practices 3-5
3.2 Carbon Adsorbers 3-6
3.2.1 Factors Affecting Performance 3-9
3.2.2 Control Efficiency 3-11
3.2.3 Current Monitoring Practices 3-11
3.3 Pollution Prevention Techniques 3-12
3.4 References 3-13
4.0 MACT FLOOR AND REGULATORY OPTIONS 4-1
iii
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Table of Contents (continued)
Page
4.1 Clean Air Act Requirements 4-1
4.2 MACT Determinations 4-2
4.2.1 Performance of Solvent Recovery Systems on Solvent Mixers 4-2
4.2.2 Selection of MACT 4-5
4.2.3 Selection of the Standard 4-9
* 4.3 Monitoring Options 4-9
4.4 References ". 4-12
5.0 MODELPROCESS UNIT 5-1
5.1 General Approach ,. 5-1
5.2 Solvent Mixers 5-2
5.2 References 5-3
6.0 ENVIRONMENTAL AND ENERGY IMPACTS 6-1
6.1 Basis for Impacts Analysis 6-2
6.2 Primary Air Pollution Impacts 6-2
6.3 Secondary Air Pollution Impacts .6-3
6.4 Water Pollution Impacts 6-5
6.5 Solid Waste Disposal Impacts 6-5
6.6 Energy Impacts 6-5
6.7 References 6-6
7.0 COST OF CONTROLS 7-1
7.1 Basis for Control Cost Analysis 7-2
7.2 Control Device Costs 7-4
7.3 Initial Compliance Costs 7-5
7.4 Monitoring Costs 7-5
7.5 Reporting and Recordkeeping Costs 7-5
. 7.6 Cost Effectiveness 7-6
7.7 New Sources 7-7
7.8 Small Businesses 7-7
7.9 References 7-7
APPENDIX A. EVOLUTION OFTHE STANDARD - A-l
APPENDIX B. EMISSION ESTIMATION METHODOLOGY B-l
B.I Plant A B-l
B.I.I Baseline and Uncontrolled Emissions B-l
B.I.2 MACT Floor and Beyond-the-Floor Emissions B-2
B.2 . Plant B B-2
B.2.1 Baseline and Uncontrolled Emissions B-2
B.2.2 MACT Floor and Beyond-the-Floor Emissions B-6
B.3 Plant C B-6
iv
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Table of Contents (continued)
B.3.1 Baseline and Uncontrolled Emissions B-6
B.3.2 MACT Floor and Beyond-the-Floor Emissions B-8
B.4 Plant D B-8
B.4.1 Baseline and Uncontrolled Emissions B-8
B.4.2 MACT Floor and Beyond-the-Floor Emissions B-8
B.5 References B-9
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List of Figures
Figure 2-1. Geographic distribution of friction products manufacturing facilities 2-3
Figure 2-2. Simplified process flow diagram for the manufacture of brake shoes
and strip lining 2-11
Figure 2-3. Simplified process flow diagram for the manufacture of disc brake pads
*,. and pucks 2-12
Figure 3-1. Typical shell-and-tube condenser .... 3-2
Figure 3-2. Typical stationary-bed, regenerable carbon adsorption system 3-8
VI
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List of Tables
Pas
Table 2-1. Friction Products Manufacturing Processes 2-4
Table 2-2. Distribution of SIC Codes Reported in ICR Responses for Major Sources in the
Friction Materials Manufacturing Source Category 2-8
Table 2-3. Small Business Association Cutoffs for SIC Codes Reported by Major Sources . 2-8
TSble 2-4. Distribution of Product Market Segments for Major Sources 2-9
Table 2-5. Distribution of Product Type for Major Sources 2-9
Table 2-6. Reported 1996 Production and Capacity for Major Sources 2T10
Table 2-7. Potential and Baseline Annual HAP Emissions from Friction Materials
Manufacturing Major Sources 2-16
Table 3-1. Condenser Operating Parameters Reported in ICR Responses 3-4
Table 3-2. Summary of Performance Indicators for Condensers 3-5
Table 3-3. Condenser Monitoring Procedures Reported in ICR Responses 3-6
Table 3-4. Summary of Performance Indicators for Carbon Adsorbers 3-11
Table 4-1. Existing Control Technologies for Potential Sources of Organic HAP Emissions
at the Four Major Source Facilities in the Friction Materials Manufacturing
Industry 4-3
Table 4-2. Summary of MACT Determinations 4-5
Table 4-3. Summary of Monitoring Options for Solvent Mixers at Friction Materials
Manufacturing Facilities 4-11
Table 5-1. Exhaust Stream Characteristics for Closed-Vent Solvent Mixer Systems 5-3
Table 5-2. Model Process Unit Exhaust Parameters for Closed-Vent Solvent Mixer Systems 5-3
Table 6-1. Nationwide Primary Air Impacts for Existing Friction Materials
Manufacturing Facilities 6-3
Table 6-2. Nationwide Secondary Air and Energy Impacts for Existing Friction Materials
Manufacturing Facilities 6-4
Table 7-1. Assumptions for Annual Cost Calculations 7-3
Table 7-2. Control Costs for Condensers Installed on Individual Solvent Mixers 7-4
Table 7-3. Nationwide Cost-effectiveness for Existing Friction Materials Manufacturing
Facilities 7-6
Table A-l. Evolution of the Standard A-l
Table B-l. Facility-Specific Uncontrolled HAP Emissions B-3
Table B-2. Facility-Specific Baseline HAP Emissions B-3
Table B-3. Facility-Specific MACT Floor HAP Emissions B-4
Table B-4. Facility-Specific Beyond-the-Floor HAP Emissions B-4
vn
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List of Acronyms and Units of Measure
BID background information document
Btu/lb British thermal unit(s) per pound
CAA Clean Air Act
CFR Code of Federal Regulations
CO carbon monoxide
CRF capital recovery factor
EPA U.S. Environmental Protection Agency
gal gallon(s)
HAP hazardous air pollutant
ICR information collection request
Ib pound(s)
Ib/gal pdund(s) per gallon
MACT maximum achievable control technology
MMBtu million Btu
mm Hg millimeter(s) of mercury
NAICS North American Industry Classification System
NESHAP national emission standards for hazardous air pollutants
NOX nitrogen oxides
NSPS new source performance standards
NTI National Toxics Inventory
OAQPS Office of Air Quality Planning and Standards
PEC purchased equipment cost
PM paniculate matter
PM10 PM with an aerodynamic diameter at or below 10 micrometers
ppm part(s) per million
SBA Small Business Administration
SIC Standard Industrial Classification
SO2 sulfur dioxide
TCE trichloroethylene
tpy ton(s) per year
TRI Toxics Release Inventory
VOC volatile organic compound
vm
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Chapter 1
Introduction
The purpose of this background information document (BID) is to summarize the background
information gathered and the analyses performed during the development of the proposed friction
materials manufacturing national emission standard for hazardous air pollutants (NESHAP). This
chapter presents the statutory basis for the NESHAP, and a discussion of the source category
listing. Chapter 2 characterizes the friction materials manufacturing industry, including an industry
profile, process description, characterization of organic hazardous air pollutant (HAP) emissions,
and a summary of existing State regulations applicable to friction materials manufacturing
facilities. Chapter 3 describes organic HAP emission control techniques that are currently being
used at friction materials manufacturing facilities and discusses pollution prevention options for
reducing air emissions of HAP. Chapter 4 describes the rationale for the determination of
maximum achievable control technology (MACT) floors, regulatory options for specific segments
of the friction materials manufacturing industry, and compliance assurance monitoring options.
Chapter 5 describes the model process units developed to evaluate the effects of the various
control options. Chapter 6 presents estimates of primary air impacts, secondary environmental
impacts, and energy impacts for existing sources resulting from the control of HAP emissions
under the proposed standards. Chapter 7 presents the cost of applying the control options and
monitoring required to meet the MACT standards and to ensure continuous compliance.
1.1 STATUTORY BASIS
Section 112 of the Clean Air Act (CAA) requires the U. S. Environmental Protection Agency
(EPA) to establish technology-based emission standards for all categories and subcategories of
major and area sources emitting one or more of the HAPs listed in §112 (b) of the CAA. These
NESHAP must represent the MACT for all major sources. Additional standards may be
1-1
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developed later under §112 (f) of the CAA to address residual risk that may remain even after
application of the technology-based controls. Section 112 (a) of the CAA defines a major source
as:
"... any stationary source or group of stationary sources located within a contiguous area
^ and under common control that emits or has the potential to emit considering controls, in
the aggregate, 10 tons per year or more of any hazardous air pollutant or 25 tons per year
or more of any combination of hazardous air pollutants."
« t
\
Potential to emit is defined in Part 70 of the Code of Federal Regulations (CFR) as, "... the
maximum capacity of a stationary source to emit any air pollutant under its physical and
operational design." Part 70 of the CFR further explains that, ". .. any physical or operational
limitation on the capacity of a source to emit an air pollutant, including air pollution control
equipment and restrictions on hours of operation or on the type or amount of material combusted,
stored, or processed, shall be treated as part of its design if the limitation is enforceable by the
Administrator."
An area source is defined as ". . . any stationary source of hazardous air pollutants that is not a
major source." The regulation of area sources is discretionary. If there is a finding of a threat of
adverse effects on human health or the environment, then the source category can be added to the
list of area sources to be regulated.
The Clean Air Act Amendments of 1990 prescribe an analytical framework that EPA is to apply in
developing NESHAP for major sources. A key concept in this framework is the establishment of
the MACT floor. Section 112 (d) of the CAA specifies that NESHAP for existing sources are to
be no less stringent (but may be more stringent) than, "... the average emission limitation achieved
by the best-performing 12 percent of the existing sources (for which the Administrator has
emissions information). .." for categories and subcategories with 30 or more sources. For
categories or subcategories with fewer than 30 sources, the MACT floor cannot be less stringent
than the average emission limitation achieved by the best-performing 5 sources. The MACT floor
1-2
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for new sources cannot be less stringent than the level of emission control that is achieved in
practice by the best-controlled similar source.
A second key feature of the NESHAP development process is that of determining subcategories.
Section 112 (d) of the CAA allows the EPA Administrator to, "... distinguish among classes,
types, and sizes of sources within a category or subcategory in establishing such standards...."
**,
The effect of this provision is that for each.category or subcategory for which EPA is developing
NESHAP, the resulting standards could be tailored to account for significant differences in
classes, types, and sizes of sources. For each of the resulting classifications, a separate MACT
»
floor determination is required.
1.2 SOURCE CATEGORY LISTING
Section 112 of the CAA requires us to list all categories of major HAP emitting sources and to
promulgate regulations for their control. An initial list of source categories and accompanying
schedules for regulation were published on December 3, 1993 (58 FR 63941).' Friction materials
manufacturing was not among the initially listed source categories. A subsequent notice published
on June 4, 1996 (61 FR 28197) added friction products manufacturing to the list of major source
categories scheduled for regulation by November 15, 2000.2 The listing was based on information
obtained in a 1992 survey of the industry from which we concluded that some facilities that
manufacture friction products have the potential to be major sources of HAP emissions. Friction
products manufacturing includes facilities that manufacture, assemble or rebuild friction products
such as brakes, or clutches. Based on additional information obtained during the development of
this proposed rule, we have determined that only facilities that manufacture friction materials have
the potential to emit HAP at major source levels. As such, this proposed rule will affect only
frict in materials manufacturers.
1.3 REFERENCES
1. U. S. Environmental Protection Agency. National Emission Standards for Hazardous Air
Pollutants Schedule for the Promulgation of Emission Standards Under Section 112(e) of
1-3
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the Clean Air Act Amendments of 1990. 58 FR 63941. Washington, DC. U. S.
Government Printing Office. December 3, 1993.
2. U. S. Environmental Protection Agency. National Emission Standards for Hazardous Air
Pollutants; Revision of Initial List of Categories of Sources and Schedule for Standards
Under Sections 112(c) and (e) of the Clean Air Act Amendments of 1990. 61 FR 28197.
Washington, DC. U. S. Government Printing Office. June 4,1996.
1-4
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Chapter 2
Friction Materials Manufacturing
Source Category
%
Friction materials manufacturing is a subset of friction products manufacturing. This chapter
characterizes the friction materials manufacturing industry source category, including facilities,
products, manufacturing processes, sources of HAP emissions, emission reduction techniques, and
summarizes applicable State regulations. The sources of information presented in this chapter
include the literature, industry representatives, site visit reports, information collection requests
(ICRs), and State and local air pollution control agencies.
Section 2.1 provides a profile of the friction materials manufacturing industry. Section 2.2
describes the friction materials manufacturing process. Section 2.3 characterizes friction materials
manufacturing HAP emission sources. Section 2.4 summarizes the available emission test data.
Section 2.5 summarizes existing State regulations that pertain to friction materials manufacturing
facilities. Section 2.6 contains a list of references.
2.1 INDUSTRY PROFILE
Broadly speaking, the friction products manufacturing industry includes any facility that
manufactures or re-manufactures friction products such as brakes and clutches. A friction product
is defined as a device that uses friction to accelerate or decelerate a vehicle or moving element of
a machine. Brakes use friction materials to slow, stop, or hold stationary a vehicle or machine
part. Clutches use friction materials to transfer kinetic energy from a power source to a
transmission to rotate wheels or equipment parts.'
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Brake friction products can be further subclassified according to design as one of the following:
brake pads, as used in light vehicle disc brakes; brake linings, as used generally in light vehicle
drum brakes; brake segments, which are strip linings used in medium-sized truck drum brakes;
brake blocks, which are brake pads used in heavy duty truck and off-road vehicle drum brakes; and
brake discs, as used in aircraft brakes. Brake pads that are manufactured and sold separately for
aftermarket use also are referred to as pucks.1
*
Clutches can be classified as wet or dry according to the type of transmission with which they are
used. Dry clutches are used with manual or standard vehicle transmissions; vehicles with
t
automatic transmissions use wet clutches, in which kinetic energy is transferred through a viscous
fluid. The friction material component of clutches is referred to as the clutch facing.1
2.1.1 Data Gathering
In 1997, ICRs were mailed to friction products manufacturing facilities to obtain detailed process
and emissions data in order to characterize the industry. These ICRs requested data for the 1996
manufacturing ydar. Information collection request responses were received from 147 facilities
(100 companies) that manufacture friction products in 34 states. These responses are believed to
represent all of the friction products manufacturing facilities in the United States. Figure 2-1
presents the geographical distribution of the 147 friction products manufacturing facilities
identified in the project database.
In addition, EPA conducted 11 site visits to 10 facilities in 7 states (including visits to 3 of the
4 facilities estimated to be major sources). Telephone cr.lls were made to many of the ICR
respondents to clarify and/or complete ICR responses and to gather additional information. The
EPA also contacted several State agencies, including Colorado, Georgia, Indiana, North Carolina,
Tennessee, and Wisconsin, for permits and emission test data
Industry information collected by the U. S. Census Bureau on the friction products industry is
contained in the "Motor Vehicle Brake System Manufacturing 1997 Economic Census Report."2
However, the data collected covers the manufacture of the entire motor vehicle brake system;
friction materials manufacturing statistics are not specified. Additional U. S. Census Bureau
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Figure 2-1. Geographic distribution of friction products manufacturing facilities.
information on the transportation industry in general is included in the Statistical Abstract of the
United States.3
2.1.2 Industry Overview
Based on a review of the ICP responses, the 147 friction products manufacturing facilities can be
organized into three basic categories: assemblers, rebuilders, and friction materials manufacturers.
Of the 147 friction products manufacturers, there are!6 friction products assemblers, 78 friction
products rebuilders and 53 friction materials manufacturers. Of the 53 friction materials
manufacturers, 2 facilities manufacture sintered friction materials, 4 facilities manufacture carbon-
based friction materials, and 47 facilities manufacture resin-based friction materials. Table 2-1
lists the manufacturing processes for which data were collected, provides the number of facilities
for each process type, and lists the products manufactured with each process. During the review
of the available information on this source category, we found that these types of friction products
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manufacturing facilities are generally different from each other with respect to types of raw
materials, process operations, and emission characteristics.
Table 2-1. Friction Products Manufacturing Processes
Manufacturing process
Assemblers3
Rebuildersb
No. of facilities
16
78 -
Product type(s)
Brake shoes; disc pads; clutches
Brake shoes; clutches
Friction Materials Manufacturers
Sintered
Carbon-based
Resin-based
Total
2
»
4
47
147
Brake discs; clutch facings
Brake discs (aircraft)
Disc brake pucks; disc brake pads; brake lining;
brake segments; brake block; brake shoes; clutch
facings; friction material
a Assemblers purchase new friction material and attach it to new steel backing plates or shoes; no new friction
material is manufactured at the facility.
b Rebuilders purchase new friction material and attach it to reconditioned brake shoes or clutch plates; no new
friction material is manufactured at the facility.
Assemblers purchase new friction material from other manufacturers and attach it to new backing
plates or shoes. Rebuilders purchase new friction material from other manufacturers and attach it
to reconditioned brake shoes or clutch plates. None of these facilities manufacture friction
material and none are major sources of HAP. Consequently, none of these facilities will be
regulated under the friction materials manufacturing NESHAP.
Friction materials manufacturers make brake and clutch linings, and in most cases assemble
finished products. Friction materials manufacturers can be classified into three classes based on
the friction material manufactured: sintered material, carbon-based material, and resin-based
material.
Two facilities manufacture sintered friction materials. Both use high-temperature sintering ovens
to fuse the non-HAP metal and mineral ingredients into a consolidated product. Neither facility is
2-4
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believed to be a major source of HAP, and, therefore, neither will be regulated under the friction
materials manufacturing NESHAP.
Four facilities manufacture carbon-based friction materials in which carbon is impregnated into a
synthetic mesh to create a friction material. Hydrogen cyanide is the only HAP known to be
emitted from this process. All four existing facilities have Federally enforceable control
requirements that limit hydrogen cyanide emissions to well below the major source threshold of
10 tons per year (tpy). In addition, we do not anticipate that any new carbon-based facilities will
be built. As a result, manufacturers of carbon-based friction materials will not be regulated under
the friction materials manufacturing NESHAP.
Forty-seven facilities manufacture resin-based friction materials. At these facilities, friction
ingredients are mixed with resins which when cured bind the friction ingredients together. In most
cases, mixing can be done without the aid of a solvent. However, for some friction materials,
solvents are needed to enhance mixing and as a process aid in later stages. Of the 47 facilities that
manufacture resin-based friction materials, only four use solvents to mix friction materials. All
four are believed to be major sources of HAP due to releases of the solvents used. The HAP-
containing solvents include n-hexane, toluene, and trichloroethylene.
Based on our review, we believe that solvent mixing is the only significant HAP emission source
associated with friction materials manufacturing. Therefore, the friction materials manufacturing
NESHAP establishes emission limitations for HAP emissions only from solvent mixers at new and
existing sources that manufacture resin-based friction materials.
2.1.6 Major Sources
The number of major sources in the source category is estimated by calculating total HAP
emissions for each facility at production capacity, considering controls already in place. Of the
147 friction products manufacturing facilities for which ICR responses were submitted, 4 were
estimated-lo be potential major sources. The emission estimation methodology is presented in
Appendix B. All four of the major sources are resin-based friction materials manufacturers that
utilize solvent mixers in the manufacturing process. These four facilities are located in Indiana,
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North Carolina, Tennessee, and Wisconsin. The remainder of this chapter will address only the
resin-based friction materials manufacturing process and the four facilities estimated to be major
sources.
There may be some friction materials manufacturing facilities which are not major for processes
included in the friction materials manufacturing source category, but which may be major for
>,
surface coating or degreasing operations. Jhese types of operations are subject to other standards
and are not regulated under the proposed friction materials manufacturing NESHAP. The specific
types of operations not included in the proposed regulation are discussed in Section 2.1.4 below.
*
2.1.4 Source Types Not Regulated
As described above, assemblers, rebuilders, sintered friction materials manufacturers, carbon-
based friction materials manufacturers, and resin-based friction materials manufacturers that do not
use solvents as process aid in mixing friction ingredients will not be included in the proposed
friction materials manufacturing NESHAP. Additionally, there are other processes that are
covered under other standards as described below.
During the manufacture of friction products, a painting process and/or an adhesive application
process may be included in the process line. The application of paints and adhesives (coatings),
including drying ovens and equipment cleaning, will be covered under the Miscellaneous Metal
Parts and Products Surface Coating NESHAP (40 CFR Part 63, Subpart MMMM), or the Plastic
Parts Surface Coating NESHAP (40 CFR Part 63, Subpart PPPP). As a result, the proposed
friction materials NESHAP will not regulate any surface coating processes. Many facilities also
perform metal preparation processes that include degreasing operations. Degreasing equipment
that uses halogenated solvents will be covered under the Halogenated Solvents Cleaning NESHAP
(40 CFR Part 63, Subpart T) and, therefore, will not be regulated under the proposed friction
materials NESHAP.
In recent years, some friction products manufacturing facilities have changed their product
formulations to remove some of the more hazardous components, such as lead and asbestos. Based
on the responses to the ICR, only three facilities reported currently using asbestos in their product
2-6
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formulations; none of these three facilities are estimated to be major sources. The asbestos
contents reported range from 43 to 75 percent, with an average of 60 percent. Asbestos emissions
from the use of asbestos-containing materials are covered under the Asbestos NESHAP (40 CFR
Part 61, Subpart M) and, therefore, are not included in the proposed friction materials
manufacturing NESHAP.
2.1.5 SIC and NAICS Codes
Friction materials manufacturing is covered by several Standard Industrial Classification (SIC)..
codes and North American Industry Classification System (NAICS) codes. Friction materials
«
manufacturing is typically classified under SIC 3714, Motor Vehicle Parts and Accessories, Brake
and Brake Systems, Including Assemblies and NAICS 33634, Motor Vehicle Brake System
Manufacturing. Some facilities manufacture other products in addition to friction materials, and
may have reported the SIC code for the product which makes up the majority of their annual
production. A summary of SIC codes reported in the ICR responses for the four major facilities,
and their respective NAICS codes, is presented in Table 2-2.
2.1.6 Small Businesses
Of the four major sources, one was determined to be a small business, based on SIC codes
reported in the ICRs and on the Small Business Association's (SBA) small business size
regulations. The SBA small business cutoffs for the SICs reported by the four major sources are
presented in Table 2-3. Small business cutoffs for the SICs reported were either 500 or 750
employees, with most cutoffs being 500 employees.4
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Table 2-2. Distribution of SIC Codes Reported in ICR Responses for Major Sources in the
Friction Materials Manufacturing Source Category
SIC code
3292
fc 3299
3499
3568
3714
Not
reported0
SIC definition
Asbestos Products
(Asbestos Brake Linings
and Pads)
Nonmetallic Mineral
Products, N.E.C. (Other
Nonmetallic Mineral
Products)
Fabricated Metal
Products, N.E.C. (Other
Metal Products)
Mechanical Power
Transmission
Equipment, N.E.C.
Motor Vehicle Parts and
Accessories (Brakes
and Brake Systems,
Including Assemblies)
Number of
facilities3
1
1
1
t
1
1
1
NAICS
code
33634
327999
332999
333613
33634
NAICS definition15
Motor Vehicle Brake System
Manufacturing (pt)
All Other Miscellaneous
Nonmetallic Mineral Product
Manufacturing (pt)
All Other Miscellaneous
Fabricated Metal Product
Manufacturing (pt)
Mechanical Power
Transmission Equipment
Manufacturing
Motor Vehicle Brake System
Manufacturing (pt)
a Total is greater than four as some facilities reported two SIC codes.
b If more than one definition was available for a specific SIC or NAICS Code, the most appropriate definition was
chosen.
0 Facilities not reporting an SIC code were assigned SIC 3714 for determining small business status.
Table 2-3. Small Business Association Cutoffs for SIC Codes
Reported by Major Sources
SIC code
3292
3299
3499
3568
3714
Small business size cutoff, no.
of employees
750
500
500
500
750
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2.1.7 Markets
The resin-based friction materials produced using solvent as a process aid are used by numerous
market segments, including railroad, automotive, and industrial. Table 2-4 summarizes the
distribution of market segments for products manufactured by the four major source friction
materials manufacturing facilities. Table 2-5 lists the product types produced by the four major
facilities. Table 2-6 summarizes the 1996 production and production capacity data reported in the
ICR responses for the four major facilities.
Table 2-4. Distribution of Product Market Segments
for Major Sources
Product market
Automotive
Railroad
Industrial
Other
Number of facilities3
2
1
1
1
Total is greater than four because one facility manufactures products for more than one
market segment.
Table 2-5. Distribution of Product Type for Major Sources
Product type
Brake lining
Brake shoe
Brake pad
Brake puck
Friction material
Industrial friction
Number of facilities3
1
1
1
1
1
1
Total is greater than four because one facility manufactures more than one product type.
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Table 2-6. Reported 1996 Production and Capacity for Major Sources3
Range (tpy)
100 to 500
501 to 1,000
* 1,001 to 10,000
10,001 to 20,000
20,001 to 40,000
Number of facilities
1996 production
2
1
0
1
0
Capacity
0
1
2
0
1
a Includes production of resin-based products only.
2.2 RESIN-BASED FRICTION MATERIALS MANUFACTURING
PROCESS
Resin-based friction materials are used to make a variety of products. Figures 2-2 and 2-3 present
simplified process flow diagrams for the manufacture of brake shoes and linings, and disc pads
and pucks, respectively. These products are manufactured primarily for the automotive industry,
but are also produced for industrial and railroad applications.
All four of the major sources reported both their actual annual production and annual production
capacity in their ICR responses. Total 1996 annual production of resin-based products where
solvent is used at these four facilities is approximately 13,000 tpy. Total 1996 annual production
capacity for these products at the four facilities is approximately 39,000 tpy. In general, the
industry is operating well below its capacity for these products, with an overall production
utilization of approximately 33 percent.
The principal operations included in the manufacture of resin-based friction materials can be
classified into four general areas: (1) raw material preparation; (2) forming; (3) curing; and
(4) assembling and finishing. These four areas, and the specific equipment types (emission units)
found in each area, are described in the following sections.5'6'7
2-10
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Non-solvent mixer
Solvent mixer
(optional)
Forming
(roll machine)
Shoe preparation
(degreasing, painting)
Curing
(curing oven, post-bake
oven)
Assembling
(adhesive application,
bonding oven, riveter)
J
Finishing
(grinding, drilling,
packaging)
Finishing
(grinding, packaging)
Finished Product:
Strip Lining
Finished Product:
Brake Shoe
Figure 2-2. Simplified process flow diagram for the manufacture of
brake shoes and strip lining.
2-11
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Non-solvent mixer
Assembling
(riveter) .
Solvent mixer
(optional)
Forming
(pre-press, hot press)
Curing
(curing oven, post-bake
oven)
Finishing
(grinding, drilling,
sawing, packaging)
Finishing
(grinding, painting,
packaging)
Finished Product:
Disc Puck
Finished Product:
Disc Brake Pad
Figure 2-3. Simplified process flow diagram for the manufacture of
disc brake pads and pucks.
2-12
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2.2.1 Raw Material Preparation
The equipment in the raw material preparation area accomplishes the blending of individual
ingredients (reinforcement material, property modifiers, resins, solvents, and other additives) in
the proportions necessary to manufacture a friction product with the desired specifications.
Process units in the raw material preparation area include mixers, granulators, and dryers.
.*»
Mixing is accomplished in discreet batches. Double-arm mixers are the most common type of
mixer used. A typical batch includes between 300 and 1,000 pounds (Ib) of friction ingredients,
and takes between 20 minutes and 1 hour, to mix. When solvents are used in the preparation of
friction materials, the solvents are typically added as a process aid to obtain a homogenous mix of
material. After mixing, most of the solvent is extracted from the friction material. However, some
solvent is allowed to remain in the friction mix as a process aid for further process operations.
Solvent mixers are typically batch mixers operated at slightly elevated temperatures. Typically,
the reinforcement material, property modifiers, resin (if any), and any other additives are loaded
into the mixer, and then the solvent is added. Some solvent mixers are completely enclosed,
having lids that seal. With this type of mixer, the solvent is pumped into the mixer after the other
ingredients have been added and the lid has been closed and sealed. After mixing, the solvent is
removed under vacuum and recovered in a solvent recovery system. The recovered solvent may
be reused in future batches of friction material mix. Other solvent mixers have covers that do not
seal; with this type of mixer the solvent is not recovered.
Batches of mixed friction material may then be processed through a granulator to obtain a uniform
particle size in the friction material. A granulator extrudes the material through a 0.25 to 0.5 inch
die, and then cuts the extruded material into 0.5 to 1 inch lengths. Uniform particle size is
important in obtaining the proper distribution of materials and optimum curing characteristics.
In some cases, friction material is dried after mixing, but before the forming step. Material dryers
use indirect heat to remove most of the remaining solvent from the mix. Natural gas or
steam is ufsd to heat the dryer to around 150°F. Fumes from the dryer may be vented through a
stack to the atmosphere, or may be released inside the manufacturing building as fugitive
emissions.
2-13
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2.2.2 Forming
The blended and prepared friction material is then transferred from the raw material preparation
area to the forming area, where the material is formed into shapes. Forming equipment includes
extruders, roll machines, and hot presses.
*;
Extruders are used to form tapes and pellets of friction material. Pellets are formed by forcing the
moist friction material through perforations in a metal die and cutting the continuously formed
strands to a predetermined length. Tapes,are formed by forcing the friction material through a
metal die with an appropriately-shaped slot in a heated extruder head.
Roll machines are used to form flat, pliable tapes, similar to those produced by an extruder, and
are also used to produce wider sheets of friction material. The moist friction material is metered
between a series of rollers which form a continuous strip of friction material with a preset width
and thickness.
Hot presses are used to form disc brake pucks, integrally-molded disc brake pads, brake segments,
and brake blocks. Hot presses apply heat and pressure over time to consolidate the friction mix
into a solid product. Premeasured quantities of friction mix are poured into each press cavity. As
heat and pressure are applied, the material is partially cured. For some IM pads, the friction
material is simultaneously attached to the metal backing plate during hot pressing; in this way they
are formed, partially cured, and assembled in one step. Hot presses may be single- or
multi-opening. Most hot presses are electrically- or steam-heated. Press temperatures range from
285° to 450°F, with an average operating temperature of 315°F. Press cycle times range from 0.2
to 240 minutes, with an average press time of about 20 minutes. Both press temperature and cycle
time vary, depending on product size and composition.
2.2.3 Curing
After the friction shapes are formed, they must be cured. Curing equipment includes curing ovens
and post bake ovens. Hot presses used to form friction material also begin the curing process;
2-14
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however, a post bake or curing oven is used to ensure that the friction material is fully cured.
Where hot presses are not used to form the friction material, uncured friction material from the
forming process is cured in batch or continuous curing ovens. Oven cycle times vary from 1 to
46 hours, with an average cycle time of 13 hours. Oven temperatures ramp up and then down over
the cycle. Oven temperatures range from 180° to 500°F, with an average temperature of 370°F.
Qj/en cycle times and temperatures vary with product size and composition.
2.2.4 Assembling and Finishing
Once the friction material is formed and cured, it is finished and assembled with some type of
metal backing. Friction material to be sold to assembly plants or to rebuilders is sold as-is, and is
not assembled with the metal backing. Finishing operations bring the friction product to final
specifications. These operations include machining, painting, and edge coding. Assembly
operations include steel preparation (i.e., degreasing), adhesive application, oven bonding,
riveting, and attachment of hardware (e.g., mounting brackets, wear sensors, and noise
suppressors).
2.3 CHARACTERIZATION OF HAP EMISSIONS FROM RESIN-BASED
FRICTION MATERIALS MANUFACTURING EMISSION UNITS
The nature and quantity of HAP emissions from the manufacturing of friction materials is driven
almost entirely by whether HAP containing solvents are used in mixing. The primary HAP emitted
from the major source friction materials manufacturing facilities are HAP solvents from mixing
operations. Currently, these include n-hexane, toluene, and trichloroethylene. The main sources of
these HAP emissions are the solvent mixers. Other potential sources of HAP solvent emissions
include granulators, dryers, extruder^, roll machines, hot presses, and ovens.
Baseline emissions are defined as actual HAP emissions from facilities in the absence of
additional regulation. Baseline emissions are estimated by calculating total HAP emissions for
each facility at actual production levels, considering controls already in place. The HAP solvent
emission estimates were developed using a mass balance approach and control technology
efficiencies. The emissions estimates for resin components (phenol and formaldehyde) are based
2-15
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on the available emission test data.8 Table 2-7 presents the potential and baseline organic HAP
emissions from the four major source friction materials manufacturing facilities.
Table 2-7. Potential and Baseline Annual HAP Emissions
from Friction Materials Manufacturing Major Sources
HAP compound
Phenol
Formaldehyde
Toluene
i
Trichloroethylene
n-Hexane
Total HAP
Potential emissions,
tpy
5.7
1.4
222.0
192.1
2,644.2
3,065.5
Baseline emissions,
tpy
2.0
0.5
62.5
18.4
556.4
639.9
Emissions from mixers can occur as solvent is added to the mixer, during the mixing cycle, and as
fugitive emissions when the mixed material is transferred from the mixer to the next process
operation. The type and quantity of organic HAP emissions from solvent mixers varies depending
on the type of solvent used, the amount of solvent used per batch, the configuration of the mixer,
and the presence or absence of a solvent recovery system. The three HAP solvents used at
solvent-based friction materials manufacturing facilities are n-hexane, toluene, and
trichloroethylene. Three of the seven solvent mixers are equipped with solvent recovery systems
designed to minimize HAP emissions and to reclaim solvent for reuse. For these mixers, the
solvent is removed from the mixed material by vacuum extraction and collected in either a
condenser (two mixers) or a carbon adsorber (one mixer). The reclaimed solvent is reused in the
process by the two facilities with condensers, and sold by the facility with the carbon adsorber.
Residual solvent that is not recovered or is emitted at the solvent mixer can be emitted in
subsequent processes as the friction material is processed through extruders, roll machines,
granulators, dryers, hot presses, and ovens. The potential for emissions from these downstream
processes is proportional to the quantity of residual solvent retained in the friction material after
mixing.
2-16
-------
Small amounts of phenol and formaldehyde (HAP components of phenolic resins) are emitted from
hot presses and curing ovens. At the four major HAP sources, phenol and formaldehyde emissions
account for less than 1 percent of the total HAP emitted. None of the existing hot presses or curing
ovens at the four major sources are equipped with HAP emission controls. Available test data
indicate that the phenol and formaldehyde emissions are on the order of 5 parts per million (ppm)
or less, which is below the level which can effectively be controlled by add-on controls.8
2.4 EMISSION TEST DATA
Minimal emission test data were received with the ICR responses. Additional test reports and
summary emission data were received from States and from follow-up calls to individual
facilities. Eight complete emission test reports and six partial or summary reports were received.
These reports include emissions data for mixers, hot presses, and curing ovens. The pollutants
tested include n-hexane, trichloroethylene, toluene, phenol, formaldehyde, and total hydrocarbons.
A summary of the available emission test data is presented in a separate memorandum.8
2.5 EXISTING STATE REGULATIONS
As mentioned previously, there are several emission units at friction materials manufacturing
facilities that are covered under other Federal emission standards; specifically, degreasing
operations, coating operations, and asbestos operations. Many States have regulations applying to
these operations. However, because these emission units are not regulated under the proposed
friction materials manufacturing NESHAP, these State regulations are not summarized in this
report. The only State regulations that have been found to be applicable to the friction materials
manufacturing sources covered under this standard are general manufacturing volatile organic
compound (VOC), particulate matter (PM), and combustion source regulations.
In addition to general VOC regulations, many States have their own air toxics programs that may
apply to friction materials manufacturing facilities. These regulations typically regulate a large
number of chemical compounds. Many States have their own list of air toxics, many of which are
also designated as organic HAP under the Clean Air Act. These air toxics regulations typically
specify allowable fenceline concentrations for the individual air toxics. If a facility's annual
emissions of a regulated compound exceed a specified level, the State may require a facility to
2-17
-------
perform dispersion modeling to determine whether the allowable concentration is exceeded at any
point beyond the fenceline. The decision to require modeling depends on several factors,
including the toxicity of the pollutant, its status as a VOC or organic HAP, the attainment status of
the location, and other considerations. If emissions exceed the allowable concentration, the
facility must reduce emissions.
*r.
One facility has a State operating permit with requirements specific to the solvent recovery system
controlling emissions from the solvent mixer at the facility. For product batches that are mixed
onsite at the facility, the State operating permit for this facility requires that the facility collect at
»
least 85 percent (by weight) of the solvent that is added to those batches, averaged over any-week.
The permit further requires that the facility calculate and record a unique batch identification
number for each batch mixed, the weight of solvent added to each batch, the weight of solvent
recovered for each batch, and the weekly average solvent collection efficiency for the recovery
system. Solvent recovery records from this facility show that a 7-day block average of 85 percent
solvent recovery has been consistently achieved.9
2.6 REFERENCES
1. Kirk-Othmer Encyclopedia of Chemical Technology. Kroschwitz, J. I. (Ed.). New York,
John Wiley & Sons. 1985.
2. U. S. Census Bureau. Motor Vehicle Brake System Manufacturing 1997 Economic Census
Report.
3. U. S. Census Bureau. Statistical Abstract of the United States: The National Data Book.
4. U. S. Small Business Administration. Small Business Size Standards. October 2000.
5. Memorandum from Midwest Research Institute, to Zapata, S., EPA/ESD. Site Visit
Report-Plant A.
6. Memorandum from Midwest Research Institute, to Cavender, K., EPA/ESD. Site Visit
Report-Plant B.
7. Memorandum from Midwest Research Institute, to Zapata, S., EPA/ESD. Site Visit
Report-Plant C.
2-18
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8. Memorandum from Abraczinskas, M., Bullock, D., Holloway, T., and Turner, M., Midwest
Research Institute, to Cavender, K., EPA/ESD. August 3, 2001. Summary of Emission Test
Data.
9. Air Pollution Control Construction and Operation Permits for Plant A.
2-19
-------
Chapter 3
Emission Control Techniques
This chapter discusses organic HAP emission control techniques that are currently being used in
%
the friction materials manufacturing industry to control emissions from solvent mixers. There are
two general approaches to reducing organic HAP emissions resulting from solvent mixers: add-on
control devices and pollution prevention.
The first approach tc limiting organic HAP emissions from solvent mixers utilizes capture systems
and add-on control devices to remove the HAP from the air stream. Recovery devices are used to
collect organic HAP (typically solvents) for reuse in the process; consequently, they are not
emitted to the atmosphere. Organic HAP in an exhaust gas stream can be collected through
condensation, or by adsorption of the contaminants onto a porous bed. Both condensers and
carbon adsorbers are used to recover HAP solvents from solvent mixers. Design, factors affecting
performance, control efficiency, and monitoring of condensers and carbon adsorbers are described
in sections 3.1 and 3.2, respectively.
An alternative approach to limiting organic HAP emissions, focusing on pollution prevention, is
highly dependent on the specific product being manufactured and its applications. Generally, the
idea is to substitute currently used materials with low-HAP or HAP-free materials (solvents,
resins, property modifiers, etc.). Section 3.3 provides a discussion of pollution prevention
opportunities in the friction materials manufacturing industry.
3-1
-------
3.1 CONDENSERS
Condensers are used to separate one or more volatile components of a vapor mixture from the
remaining vapors through saturation followed by a phase change. The phase change from gas to
liquid can be achieved in two ways: (1) by increasing the system pressure at a given temperature,
or (2) by lowering the temperature at a constant pressure.1'3 Because condensers typically reduce
the temperature of the gas stream with a coolant, this section addresses the latter method. A
schematic diagram of a typical condenser is provided in Figure 3-1.
inlet
Vapor
inlet
NoBcondcming
vapor outlet
Straight Kunk«
tube*
t
Revcnmf
channel
Inlet
Coolant channel
outlet
Condenute
outlet
Figure 3-1. Typical shell-and-tube condenser.3
Condensers can generally be classified as either surface condensers or contact condensers.
Surface condensers are usually shell-and-tube heat exchangers. The coolant typically flows
through the tubes and the vapors condense on the shell outside the tubes. The condensed vapors
form a film on the cool tubes and drain by gravity to a collection tank for storage or disposal. No
secondary pollutants are generated from the operation of surface condensers because the coolant
flows thrangh a closed system.1"3 Based on the responses to ICRs, the condensers in place at
friction materials manufacturing facilities are surface condensers.
3-2
-------
Contact condenser designs are similar to spray towers. In contrast to surface condensers where
the coolant does not contact either the vapors or the condensate, in contact condensers, the vapor
mixture is cooled by spraying a cool liquid directly into the gas stream.1"3
Condensation occurs when the partial pressure of the condensible pollutant in the waste gas stream
is equal to its vapor pressure as a pure substance at the operating temperature of the condenser.
*_
The waste gas stream is cooled by transfer_of its heat to a refrigerant or coolant; the waste gas
becomes saturated with one or more of its pollutants at the dew point or saturation temperature,
and as the gas continues to cool, the pollutants condense. The dew point temperature can be
»
predicted from the temperature-vapor pressure curve for the pollutant and its mole fraction in the
waste gas stream. The temperature required to achieve a given removal efficiency or outlet
concentration depends on the outlet vapor pressure of the pollutant at vapor-liquid equilibrium.
When the partial pressure is known, the condensation temperature can be determined (using
temperature-vapor pressure relationship, such as Antoine's equation).1'3
3.1.1 Factors Affecting Performance
The design and operation of a condenser are affected significantly by the number and nature of the
components present in the emission stream. For example, condenser efficiency is sensitive to the
inlet HAP concentration. In most HAP control applications, the emission stream will contain large
quantities of noncondensible and small quantities of condensible compounds. To separate the
condensible component from the gas stream at a fixed pressure, the temperature of the gas stream
must be reduced. The more volatile a compound (i.e., the lower the normal boiling point), the
larger the amount that can remain as vapor at a given temperature; hence the lower the temperature
required for saturation (condensation).2
The coolant used in a condenser depends upon the saturation temperature needed to condense the
pollutants of interest in the gas stream. Chilled water can be used for condensation temperatures
that are below 7°C (45°F), brines for below -34°C (-29°F), and chlorofluorocarbons for
condensation temperatures below -34°C (-29°F). Temperatures as low as -62°C (-80°F) may
be necessary to condense some streams. When such low temperatures must be achieved to reach
3-3
-------
the dew point for a particular pollutant, other components of the waste gas stream, such as water,
can solidify and foul the heat transfer surface.13
Table 3-1 summarizes the condenser operating parameters provided in the ICR responses.
Table 3-1. Condenser Operating Parameters Reported in ICR Responses
Condenser type
Non Contact
Non Contact
Vertical
n/a
Shell and Tube
Shell and Tube
Shell and Tube
Surface (Indirect)
Coolant
freon
water
water
refrigerant
water
water
water
glycol
Inlet gas temperature,
°C (°F)
40 (100)
65 (150)
90 (190)
n/a
90 (190)
n/a
n/a
90 (190)
Outlet gas temperature,
°C (°F)
10 (50)
15 (60)
25 (80)
n/a
50 (120)
65 (150)
65 (150)
15 (60)
n/a = not available
3.1.2 Control Efficiency
Condensers generally achieve removal efficiencies ranging from 50 to 95 percent. The removal
efficiency of condenser systems designed to control exhaust streams containing air/organic HAP
mixtures depends primarily on the following parameters:
Inlet and outlet waste gas temperature;
Volumetric flow rate of the waste gas stream;
Inlet and outlet coolant temperature;
Concentrations of the organic HAP in the exhaust stream;
Absolute pressure of the vent stream; and
Properties of the organic HAP in the vent stream (dew points, heats of condensation,
heat capacities, and vapor pressures).1'3
3-4
-------
The performance of two existing condensers installed as solvent recovery devices on solvent
mixers at friction materials manufacturing facilities was evaluated. For the first condenser, only
anecdotal information on recovery efficiency was available. However, reliable data documenting
>
recovery efficiency is available for the second condenser. Solvent recovery records from this
facility show that a 7-day block average of 85 percent solvent recovery has been consistently
achieved.
**
3.1.3 Current Monitoring Practices
The primary indicators of the performance of condensers are the condenser outlet VOC
concentration, condenser outlet temperature, and coolant inlet temperature. Other parameters that
indicate condenser performance include coolant outlet temperature, exhaust gas flow rate, pressure
drop across condenser, coolant flow rate, pressure drop across coolant recirculation system, and
condensate collection rate. Table 3-2 lists these indicators and briefly describes the relationship
of the indicator to condenser performance. A summary of ICR responses indicating the existing
monitoring procedures for condensers at friction materials manufacturing facilities is presented in
Table 3-3. Generally, the existing parameters monitored include outlet gas temperature, outlet
coolant temperature, and system pressure drop.
Table 3-2. Summary of Performance Indicators for Condensers
Parameters
Performance indication
Comments
Primary indicators of performance
Outlet VOC concentration
Outlet temperature
Coolant inlet temperature
Direct measure of outlet
concentration.
Indicates if gas is being cooled
to/below dewpoint of target
compounds; indicator of level of
condensation.
Indicates if condenser is operating
as designed
Best indicator of condenser performance, can be
monitored continuously or periodically.
Too high indicates condensation to the level expected wil
not occur; decrease in outlet temperature may indicate
plugging or fouling problems.
If inlet gas temperature and flow rate do not vary, is
comparable to outlet gas temperature as indicator of
condenser performance; increase in coolant inlet
temperature indicates lower organic compound removal
rate.
3-5
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Table 3-2. (continued)
Parameters
Performance indication
Comments
Other performance indicators
>,
Coolant outlet temperature
Exhaust gas flow rate
Pressure drop across
condenser
Coolant flow rate
Pressure drop across
coolant recirculation system
Condensate collection rate
Periodic inspection
If coolant inlet temperature and are
flow rates also are measured,
indicates level of heat transfer from
inlet exhaust stream.
Determines residence time within
condenser.
Indicator of plugging or fouling
within condenser.
Affects heat transfer rate.
Indicates plugging and/or fouling of
condenser coolant tubes.
Organic compound removal rate.
Fouling of tubes, corrosion.
By itself, would be less reliable indicator of performance
than other parameters listed above; increase would
indicate decrease in organic compound removal rate.
Increase in flow rate could indicate a decrease in
condenser performance.
Increase in pressure drop indicates obstruction in
condenser and likely decrease in condenser performance;
fouling decreases heat transfer rate.
Decrease indicates decrease in condenser performance;
parameter is of limited use without coolant temperature
data.
Comparable to monitoring coolant flow rate (see above).
Useful indicator of condenser performance only if procesi
gas stream characteristics do not vary.
Fouling decreases heat transfer.
Table 3-3. Condenser Monitoring Procedures Reported in ICR Responses
Parameters
monitored
Different
pressures
Temperature
Vacuum pressure
Temperature
Water & gas outlet
temperature
Monitoring
frequency
Daily
Daily
Continuous
Continuous
Daily
Type of device used
Pressure gauge
Built in gauge
Pressure gauge
Temperature gauge
Dial thermometers
Recordkeeping
procedures
Recorded manually
Recorded manually
Manually recorded
per batch
Manually recorded
per batch
Maintain log of
water temperature
Operation and maintenance
Equipment
As needed
As needed
Check per batch
Check per batch
Control device
Visual inspection of
structure, daily
Visual inspection of
cooling and filter
chamber, weekly
Visual inspection
Visual inspection
Clean condensers as
required
3.2 CARBON ADSORBERS
3-6
-------
Carbon adsorbers are used for both air pollution control and solvent recovery. The carbon
adsorption process used to control organic HAP and VOC emissions from waste gas streams can
be subdivided into two sequential processes. The first process involves the adsorption cycle, in
which the waste gas stream is passed through the adsorbent bed for contaminant removal. The
second process involves regeneration of the adsorbent bed, in which contaminants are removed
using a small volume of steam or hot air and recovered using condensation, so that the adsorbent
At
(carbon) can be reused for contaminant removal. ,
Adsorption is the capture and retention of a contaminant (adsorbate) from the gas phase by an
adsorbing solid (adsorbent). The four types of adsorbents most typically used are activated
carbon, aluminum oxides, silica gels, and molecular sieves. Activated carbon is the most widely
used adsorbent for air pollution control and is the only type of adsorbent discussed in this section.4
The two main mechanisms of adsorption are physical adsorption and chemisorption. Physical
adsorption (otherwise known as van der Waals adsorption) uses a weak bonding of the adsorbate
molecules to the adsorbent. The van der Waals forces within the bond are similar to the forces
that attract molecules in a liquid and are easily overcome by the application of heat or the
reduction of pressure. Chemisorption uses chemical bonding by inducing a reaction between the
adsorbate and the adsorbent.5
There are three basic types of adsorption systems, which can be categorized by the manner in
which the adsorbent bed is maintained or handled during the adsorption and regeneration cycles.
These three types of systems are: (1) fixed or stationary bed, (2) moving bed, and (3) fluidized
bed. The stationary bed design is the most common and is the only design described in this
section.
A stationary-bed, regenerable carbon adsorption system is depicted in Figure 3-2. The
components of the carbon adsorption system include a fan (to convey the waste gas into the carbon
beds); at least two stationary-bed carbon adsorption beds; a stack for the treated waste gas outlet;
a steam valve for introducing desorbing steam; a condenser for the steam/contaminant desorbed
stream; and a decanter for separating the organic HAP condensate and water.
3-7
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Exhaust air
Vapor-ladto
air inltt
Activtwd carbon
1
carbon
IJ
Continuous
r.
Low-praurt nwn
Figure 3-2. Typical stationary-bed, regenerable carbon adsorption system.1
In a typical dual stationary-bed system, the vapor is collected from various sources, transported
through a particulate filter and into one of two carbon adsorption beds. As the carbon adsorber
operates, three zones form within the bed: the saturated zone, mass transfer zone, and fresh zone.
In the saturated zone, which is located at the entrance to the bed, the carbon has already adsorbed
its working capacity of VOC; no additional mass transfer can occur in this zone. The mass transfer
zone is where VOC is removed from the gas stream. The carbon in this zone is at various degrees
of saturation, but is still capable of adsorbing VOC. The fresh zone is the region of the bed that
has not encountered VOC-laden air since the last regeneration. This zone has a full working
capacity available for adsorption of additional VOC.
As the carbon bed operates, the mass transfer zone moves through the bed in the direction of flow
toward the bed outlet. Breakthrough occurs when the mass transfer zone first reaches the bed
3-8
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outlet. At this point, a sharp increase in the outlet VOC concentration occurs. The available
adsorption time (the time before breakthrough occurs) depends on the amount of carbon in the bed,
the working capacity of the bed, and the VOC concentration and mass flow rate of the gas stream.
Once the breakthrough point is reached, the carbon bed must be regenerated. When this occurs, the
flow of VOC-laden air is redirected to the second bed, while the first bed undergoes a
regeneration cycle.
Regeneration is the process of desorbing (that is, reversing the adsorption process and separating
the contaminants from the carbon), and is accomplished by increasing the temperature and/or
%
reducing the system pressure. The most common method of regeneration is steam stripping. Low-
pressure, superheated steam is introduced into the carbon bed. The steam desorbs and carries the
VOC through a condenser, then through a decanter and/or distillation column for separation of the
VOC from the steam condensate.
Another regeneration method is the use of hot, inert gas or hot air. With either steam or hot air
regeneration, the desorbing agent flows through the bed in the direction opposite to the waste
stream, allowing the exit end of the carbon to remain contaminant-free. The regenerated carbon
bed is then ready to be put back on-line when the second bed reaches breakthrough.13>4
3.2.1 Factors Affecting Performance
Several factors affect the amount of material that can be adsorbed onto the carbon bed. These
factors include type and concentration of contaminants in the waste gas, system temperature,
system pressure, humidity of waste gas, and residence time.6
The type and concentration of contaminants in the waste stream'are major factors in the adsorption
capacity of the carbon. In general, adsorption capacity increases with a compound's molecular
weight or boiling point, provided all other parameters remain constant. There is also a
relationship between concentration and the carbon adsorption capacity. As concentration
decreases, so does the carbon capacity. However, the capacity does not decrease proportionately
with the concentration decrease.6
3-9
-------
Increases in operating temperature decrease adsorption efficiency. At higher temperatures, the
vapor pressures of the contaminants increase, reversing the mass transfer gradient. Contaminants
would then be more likely to return to the gas phase than to stay on the carbon. At lower
temperatures, the vapor pressures are lower, so the carbon will likely retain the contaminants.7
Increases in the system pressure improve the effectiveness of adsorption. Increases in the gas
phase pressure promote more effective and rapid mass transfer of the contaminants from the gas
phase to the carbon. Therefore, the probability that the contaminants will be captured is
increased.4
*
Although water vapor is not preferentially adsorbed over the contaminants, increases in the
relative humidity or moisture content of the gas phase generally reduce adsorption efficiency.
However, the effect of humidity in the gas phase is insignificant for VOC concentrations greater
than 1,000 parts per million (ppm) and during the initial startup of the adsorption cycle (when the
carbon is drier). In some instances moisture content in the gas phase can be beneficial. For
instance, when high concentrations of contaminants with high heats of adsorption are present, the
temperature of the carbon bed may rise considerably during adsorption due to the exothermic
nature of the process. The presence of water may minimize the temperature rise.6
Adsorption efficiency may also be reduced if contaminants do not have enough contact (residence)
time with the active sites of the carbon to allow mass transfer to occur. Contaminants especially
need this time if many molecules (high-concentration streams) are competing for the same sites.
Residence time of the contaminants with the active sites can be increased by using larger carbon
beds, but then the pressure drop across the system increases, resulting in increased operating
cos^.4
3.2.2 Control Efficiency
Carbon adsorption recovery efficiencies of 95 percent and greater have been demonstrated to be
achievable in well-designed and maintained units.2 The performance of the carbon adsorption unit
is negatively affected by elevated temperature, low pressure, and high humidity, as previously
3-10
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discussed. One carbon adsorber is in use on a solvent mixer and halogenated solvent degreaser at
a major friction materials manufacturing facility. The adsorber system has demonstrated a VOC
capture efficiency of 94 percent and a VOC removal efficiency of 99.8 percent, which yields a
VOC control efficiency of 93.8 percent for the solvent mixing and degreasing operations.8
However, this system was not operating under representative conditions during the test, and these
non-representative data were not sufficiently reliable to use in establishing the level of the
>.
standard. Additionally, the overall control efficiency does not equate to solvent recovery because
it does not account for the residual solvent remaining in the mixed material.
3.2.3 Current Monitoring Practices
The primary indicators of the performance of carbon adsorbers are the adsorber outlet VOC
concentration, regeneration cycle timing, and integrated steam flow. Other indicators of adsorber
performance include bed operating temperature, inlet gas temperature, gas flow rate, inlet VOC
concentration, pressure drop, and inlet gas moisture content. Table 3-4 lists these indicators and
briefly describes the relationship of the indicator to adsorber performance. The only monitoring
practice reported in the ICR responses was taking semi-annual samples of the carbon for bed
breakthrough and carbon quality.
Table 3-4. Summary of Performance Indicators for Carbon Adsorbers
Parameters
Performance indication
Comments
Primary indicators of performance
Outlet VOC
concentration
Regeneration
cycle timing
Integrated steam
flow
Direct measure of outlet
concentration.
Key factor in determining adsorptive
capacity of bed.
Determines extent to which bed is
desorbed (regenerated).
Best indicator of adsorber performance; can be
monitored continuously or periodically.
If regeneration cycles are too infrequent, VOC
emissions may be excessive; if regeneration
times are too short, the adsorption capacity of the
bed is reduced.
Decreases in steam flow result in a shorter time
period to reach breakthrough.
Other performance indicators
Bed operating
temperature
Affects adsorptive capacity of bed.
Adsorptive capacity decreases with increasing
temperature.
3-11
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Table 3-4. (continued)
Parameters
Inlet gas
lemperature
Gas flow rate
Inlet VOC
concentration
Pressure drop
across adsorber
Inlet gas moisture
content
Performance indication
Indicator of bed operating
temperature (see above).
Adsorption capacity of bed.
System is operating within design
limits.
Indicator of fouling or channeling
within bed.
Adsorptive capacity of bed.
Comments
Not as useful as bed operating temperature as an
indicator of performance, but is an alternative to
monitoring bed operating temperature.
Increases in flow rate result in a shorter time
period to reach breakthrough.
Increases in VOC concentrations may require
adjustments to regeneration cycle timing.
Increase in pressure drop can indicate fouling of '
bed; decrease in pressure drop can indicate
channeling.
High moisture content can result in reduced
adsorptive capacity of bed; applies to inlet VOC
concentrations less than -1,000 ppm.
3.3 POLLUTION PREVENTION TECHNIQUES
Pollution prevention alternatives for reducing air emissions associated with friction materials
manufacturing can vary widely. The pollution prevention practices involving friction material
formulations are influenced by the specific product being manufactured, and the product
performance requirements that must be met. Therefore, specific pollution prevention techniques
will vary with different products and applications.
Generally, replacing HAP-containing organic process solvents and resins with non-HAP materials
has been demonstrated in several products and applications. A specific reformulation technique
that may have been employed at one facility to reduce air emissions, however, may not work for
another facility. Techniques involving the reuse of scrap materials, reject products, and baghouse
catches have also been demonstrated as pollution prevention practices.
3.4 REFERENCES
3-12
-------
1. Air Pollution Engineering Manual. Buonicore, A. J. and Davis, W. T. (Eds.)- New York,
Van Nostrand Reinhold Company. 1992.
2. U. S. Environmental Protection Agency. Handbook: Control Technologies for Hazardous
Air Pollutants. EPA 625/6-91/014. Cincinnati, OH. July 1991.
3. U. S. Environmental Protection Agency. APTI Course 415, Control of Gaseous Emissions,
Student Manual. EPA 450/2-81-005. Research Triangle Park, NC. December 1981.
At
4. Bethea, R. M. Air Pollution Control Technology. New York, Van Nostrand Reinhold
Company. 1978.
5. Cooper, C. D. and Alley, F. C. Air Pollution Control: A Design Approach. Prospect
Heights, IL, Waveland Press, Inc.« 1994.
6. Calgon Corporation. Introduction to Vapor Phase Adsorption Using Granular Activated
Carbon.
7. Prudent Practices for Disposal of Chemicals from Laboratories. Washington, D.C.,
National Academy Press. 1983.
8. Emi s si on Test Report for PI ant C.
3-13
-------
Chapter 4
MACT Floor and Regulatory Options
This chapter describes the CAA requirerrtents for MACT standards, the methodology and
conclusions of the MACT floor analyses for the friction materials manufacturing source category,
regulatory options considered, and monitoring options identified for the emission units and HAP to
be regulated.
4.1 CLEAN AIR ACT REQUIREMENTS
The amended CAA contains requirements for the development of NESHAP for sources of HAP
emissions. The statute requires the standards to reflect the maximum degree of reduction in
emissions of HAP that is achievable for new and existing sources. This control level is referred to
as MACT. The amended CAA also provides guidance on determining the least stringent level of
control allowed for a MACT standard; this level is termed the "MACT floor."
The approach to selecting the MACT floor depends on the number of major and synthetic area
sources in each source category. Section 112 (d)(3) of the CAA specifies that NESHAP for
existing sources are to be no less stringent (but may be more stringent) than, ". . . the average
emission limitation achieved by the best-performing 12 percent of the existing sources (for which
the Administrator has emissions information). . . ." We have interpreted the "average" emission
limitation as the median of the best-performing 12 percent, or the 94th percentile. In categories or
subcategories with fewer than 30 major and synthetic area sources, the MACT floor is to be based
on the average emission limitation achieved by the best-performing five sources. We have
interpreted the "average" emission limitation as either the mean or median emission limitation of
4-1
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those best-performing five sources. The MACT floor for new sources corresponds to the level of
emission control that is achieved in practice by the best controlled similar source.
4.2 MACT DETERMINATIONS
For NESHAP developed to date, we have used several different approaches to determine the
MACT floor and beyond-the-floor options for individual source categories depending on the type,
quality, and applicability of available data. These approaches are based on: (1) emissions test
data that characterize actual HAP emissions from presently controlled sources included in the
source category'; (2) existing federally-enforceable emission limitations specified in air
regulations and facility.air permits applicable to the individual sources comprising the source
category; and (3) application of a specific type of control technology for air emissions currently
being used by sources in the source category or by sources with similar pollutant stream
characteristics. The available emission test data and the existing State regulations and permit data
are inadequate for establishing the MACT floor for the friction materials manufacturing industry;
therefore, the MACT floor will be technology-based.
4.2.1 Performance of Solvent Recovery Systems on Solvent Mixers
As reported previously, we surveyed the entire friction materials manufacturing industry and
determined that four facilities with solvent mixers emit HAP in excess of the major source levels.
Combined, these four facilities (Plants A, B, C, and D) operate a total of seven solvent mixers, of
which three are equipped with air pollution controls (solvent recovery systems), and four have no
control. Table 4-1 lists the control technologies in place on the various emission sources at the
four major source facilities in the friction materials manufacturing industry. The following
paragraphs briefly describe the solvent mixers in place at each of the four facilities and the
performance of the solvent recovery systems.
4-2
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Table 4-1. Existing Control Technologies for Potential Sources of Organic HAP Emissions
at the Four Major Source Facilities in the Friction Materials Manufacturing Industry
Emission unit
Extruder
Granulator
ftot press
Material dryer
Mixer (solvent)
Oven
Roll machine
Total number
6
3
104
16
7
42
4
No controP
No.
6
3
104
16
4
42
4
%
100
100
100
100
57
100
100
Carbon adsorber
No.
1
%
14
Condenser
No.
2
%
29
" Includes emission units with fabric filters; fabric filters are expected to provide no control for organic HAP
emissions.
Plant A has one solvent mixer that uses toluene as the solvent.1 According to information on air
releases reported by the facility to the 1997 Toxics Release Inventory (TRI), air emissions of
toluene are on the order of 45 tpy.2 After mixing, solvent is drawn out of the mixer under a strong
vacuum.1 Data collected by facility personnel indicate that typically more than 95 percent of the
solvent is removed from the mixed material, with less than 5 percent remaining in the mix.1 The
evacuated solvent vapors are then condensed in a non-contact, glycol-chilled condenser which
cools the vapors to 32°F.' Liquid condensate is collected and recycled to the process, and
uncondensed vapor is exhausted to the atmosphere through a stack.1
Plant A has a State operating permit which requires that the facility collect at least 85 percent (by
weight) of the solvent that is added to the mixer, averaged over a calender week.1 The percent
solvent recovery is determined for each individual mix batch by weighing the amount of solvent
loaded into the mixer, and weighing the amount of solvent recovered by the. condenser.1 Plant A
began collecting solvent recovery data for each batch in January 1999. We reviewed the solvent
recovery records from January 1999 through October 1999 and found that the 85 percent solvent
recovery limit has been consistently achieved on a weekly, or 7-day block average, basis.3
4-3
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Plant B has four solvent mixers that use n-hexane as the solvent.4 Again,-based on self-reported
emissions data to TRI for 1998, Plant B emits approximately 450 tpy of n-hexane.5 Three of the
four mixers have no air pollution controls.4 All of the solvent added to these mixers is emitted to
the atmosphere. The fourth mixer has a solvent recovery system similar to the one described for
Plant A.4 Solvent is drawn out of the mixed material by vacuum.4'6 The solvent vapors are then
collected by a non-contact, Freon-cooled condenser, which cools the solvent vapor to 60 °F.4 Once
per quarter, Plant B performs a solvent mass balance for one batch to evaluate the performance of
the solvent recovery system.7 The amount of solvent added to the mixer is measured using a
calibrated flow meter, and the amount of solvent recovered by the condenser is weighed.8 The
results of these measurements indicate that approximately 70 percent of the solvent is recovered by
the solvent recovery system on average.4 Using these data and the overall system efficiency,
facility personnel have determined that approximately 90 percent of the solvent is removed from
the mix by the solvent recovery system, and that the condenser removes approximately 80 percent
of the solvent vapors.4
Plant C has one solvent mixer that uses trichloroethylene as the solvent.9 Based on the self-
reported emissions data to TRI for 1998, Plant C emits approximately 30 tpy of
trichloroethylene.10 As with the other two controlled mixers, solvent is removed from the mixer
under vacuum.9 No data are available on how much of the solvent is removed from the mixed
friction material by the vacuum system. The solvent vapors are combined with the emissions from
a solvent degreaser, and the commingled vapors are collected in a carbon adsorber.9 The
adsorbed solvent is recovered weekly by steam stripping the adsorber bed, and the recovered
solvent is sold. Performance data based on a single inlet/outlet emissions test conducted in 1996
indicate that the subject adsorber is capable of achieving 94 percent control.11 It should be noted
that control efficiency does not equate to solvent recovery because it does not account for the
residual solvent content remaining in the mixed material. If one assumes that the residual solvent
content is similar to that achieved at Plant A and Plant B (i.e., between 5 and 10 percent), then the
corresponding percent of solvent recovered would be on the order of 85 to 90 percent.
4-4
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Plant D has one solvent mixer that uses toluene as the solvent.12 Based on the self-reported
emissions data to TRI for 1998, Plant D emits about 40 tpy of toluene.13 Plant D has no air
pollution controls on its mixer, and 100 percent of the solvent used is emitted to the atmosphere.12
4.2.2 Selection of MACT
We have determined that the MACT floor for existing mixers is a solvent recovery system with a
70 percent solvent recovery efficiency, and the MACT floor for new mixers is a solvent recovery
system with a 85 percent solvent recovery efficiency. We have also determined that it is both
technically and economically feasible for, existing mixers to achieve better than the MACT floor
level of control. Therefore, we are establishing MACT for both new and existing solvent mixers
at 85 percent solvent recovery efficiency. Table 4-2 summarizes the MACT floor and MACT
determinations for the sources at the four major source facilities in the friction materials
manufacturing industry. The following paragraphs describe how we determined the MACT floors,
and our rationale for going beyond the MACT floor for existing mixers.
Table 4-2. Summary of MACT Determinations
Emission unit
Extruder
Granulator
Hot press
Material dryer
Mixer (solvent)
Oven
Roll machine
MACT floor
control technology
No control
No control
No control
No control
Solvent recovery
No control
No control
MACT floor for
existing sources
No control
No control
No control
No control
70% control
No control
No control
MACT for
existing sources
No control
No control
No control
No control
85% control
No control
No control
MACT floor for
new sources
No control
No control
No control
No control
85% control
No control
No control
Because there are only seven solvent mixers (fewer than 30 sources), the MACT floor for existing
solvent mixers is based on the best-performing five sources. The available information does not
allow for a floor calculation based on actual emissions data or State limits. However, ranking the
sources by the estimated performance of the control technology applied allows for a floor
determination based on the median of the best-performing five sources, i.e., the third best-
performing source.
4-5
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Each of the three mixers with control is equipped with a solvent recovery system comprised of
two components: a vacuum system to remove the solvent from the mixed material, and a control
device that recovers the solvent from the exhaust. The overall performance of these systems is
determined by the performances of the individual components, i.e., the efficiency of the vacuum
system at removing solvent from the mixed material, and the efficiency of the control device in
removing the solvent vapors from the vacuum exhaust.
Both Plant A and Plant B use a condenser to recover the solvent vapors. Based on the available
data, Plant A's recovery .system performs better than the recovery system used at Plant B. Plant
«
A's vacuum system removes 95 percent of the toluene from the mixer, and the condenser removes
90 percent of the solvent vapor, resulting in an overall solvent recovery efficiency of 85 percent.
Plant B's vacuum system is estimated to remove 90 percent of the n-hexane from the mixer, and the
condenser removes 80 percent of the n-hexane vapors from the. vacuum exhaust, resulting in an
overall solvent recovery efficiency of 70 percent.
Plant C uses a carbon adsorber to recover the trichloroethylene solvent vapors contained in the
vacuum exhaust coming from the mixer. The 94 percent control efficiency estimated for the carbon
adsorber is the highest of the three control devices applied. However, as stated previously, we
have no information from which to assess the effectiveness of the vacuum system at removing the
solvent from the mixed material. Without this information, we cannot determine the overall
solvent recovery efficiency achieved by the vacuum systems and carbon adsorbers together.
Therefore, for the purpose of determining the MACT floor, we have assumed that the recovery
system at Plant C is comparable to that of the system at Plant A, and we have assigned it an
85 percent solvent recovery efficiency.
Given the above, the ranking of the five best sources for purposes of the floor determination is as
follows: 85 percent for Plant A and Plant C, 70 percent for Plant B, and 0 percent recovery for
any two of the remaining mixers. The third best-performing source and, thus, the MACT floor for
existing solvent mixers is the mixer at Plant B with 70 percent solvent recovery'. The MACT floor
for new mixers is based on the best-performing solvent recover}' system. We have determined that
4-6
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Plant A has the best-performing solvent recovery system, and we have set the MACT floor for new
mixers at an 85 percent solvent recovery efficiency.
Next, we evaluated options that would be more stringent than the floor. Clearly, requiring existing
mixers to meet an 85 percent solvent recovery efficiency is an option for existing mixers. To
evaluate technical feasibility of this option, we examined whether a better-designed and operated
solvent recovery system could achieve an 85 percent solvent recovery efficiency on Plant B's
solvent mixing operation. Plant B was selected because it had the lowest performing solvent
recovery system of the three controlle'd mixers. We looked at the volatility of the three different
t
solvents used at the existing solvent mixers to determine if trie volatility of the solvents could limit
the vacuum system efficiency, such that, for certain solvents, an 85 percent solvent recovery
efficiency could not be achieved. Vacuum systems remove solvent from the mixed material by
evaporation at low pressure. Consequently, the higher the volatility of the solvent, the more easily
it can be removed by a vacuum system. Of the three solvents used, n-hexane is the most volatile,
while toluene is the least volatile. Based on the available data, Plant A's vacuum system
efficiency of 95 percent is the best of the existing systems. Because Plant A also uses the least
volatile solvent, it is clear that a vacuum system efficiency of 95 percent can be achieved for all
three of the solvents used at the existing facilities.
We then evaluated the condenser used at Plant B, the poorer performer of the sources with
condensers, to determine if improvements to condenser efficiency are possible. The key parameter
that determines condenser performance for a given solvent is the outlet temperature of the
condenser. The lower the outlet temperature of the condenser, the more solvent will be
condensed, and the higher the condenser efficiency will be. For Plant B, the condenser outlet
temperature is 60°F. This compares to an outlet temperature of 32°F at Plant A. Condenser outlet
temperatures of 32°F can be obtained with either a glycol-cooled condenser, or a Freon-cooled
condenser. The vapor pressure of n-hexane, the solvent used at Plant B, is estimated to be
approximately 100 millimeters of mercury (mm Hg) at 60°F. At 32°F, the vapor pressure of n-
hexane is estimated to be approximately 50 mm Hg. This indicates that the penetration (the amount
of solvent that is not condensed) would be halved by lowering the condenser outlet temperature at
Plant B from 60 °F to 32 °F. Because the current condenser is estimated to be 80 percent efficient,
4-7
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we would predict that a condenser with a 32 °F outlet temperature would achieve 90 percent
efficiency on this gas stream. If Plant B were to install both an improved vacuum system and an
improved condenser, we predict the overall solvent recovery would be 85 percent (0.95 x 0.90 x
100 percent = 85 percent). Based on the above analysis, we believe that it is technically feasible
to achieve 85 percent solvent recovery on each of the existing solvent mixers used at friction
manufacturing facilities.
We also believe that it is economically feasible to achieve 85 percent solvent recovery on each of
the existing solvent mixers. The incremental costs to install and operate a solvent recovery system
that achieves 85 percent over that of a system that would achieve 70 percent are minimal.
Furthermore, because the recovered solvent can be reused in the process, the costs of solvent
purchases will be greatly reduced, which we believe would more than offset the costs of installing
and operating the solvent recovery system.
We also evaluated and rejected an option that would prohibit the use of HAP solvents altogether.
The HAP solvent usage has declined significantly as friction material manufacturers develop
formulations and processes that either use non-HAP solvents or need no solvents in the mixing
process (i.e., dry mixing). Personnel at Plant B and Plant C are actively working to identify
alternatives to the HAP solvents they currently use. Plant B uses a dry mixer to mix many of the
formulations it currently makes, but they must use n-hexane to mix those formulations where the dry
mixing process cannot meet the performance characteristics needed. They have also investigated
several non-HAP solvents, but they have not yet identified an acceptable alternative to n-hexane.
Plant C uses non-HAP solvents to mix many of the friction materials they manufacture, but still
have a number of formulations that require the use of trichloroethylene to achieve the necessary
characteristics. While it may be possible in the future to eliminate the use of HAP solvents from
all friction materials manufacturing, we believe it is not currently feasible to eliminate HAP
solvents from all friction materials manufacturing.
4.2.3 Selection of the Standard
The CAA requires us to set numerical emission limitations if feasible, and it prohibits use of
operational standards, unless we can demonstrate that the setting and enforcement of an emission
4-8
-------
limitation is infeasible. Consequently, we have selected a format for the standard that expresses
the goal of 85 percent solvent recovery as an emission limit based on the amount of solvent loaded
into the mixer and the amount recovered. Specifically, the proposed standard would limit the HAP
solvent emissions to the atmosphere to no more than 15 percent of that loaded into the solvent
mixer.
*
We also evaluated several averaging times to determine an appropriate averaging time for the
standard. We determined that long averaging times (such as a 30-day or annual average) would
not be appropriate because they would allow for long periods of under-performance by the solvent
*
recovery system. In addition, one deviation from a 30-day or annual average would put the facility
at risk of being determined to be out of compliance for the entire period. We determined that
requiring compliance on a per-batch basis (i.e. no averaging) would also be inappropriate because
it would not accommodate normal variability in the residual solvent requirements for different
product mixes. The use of a 7-day block average provides time to detect and correct problems
(e.g., individual mix batches not achieving the emission limitation) without the risk of the longer
averaging periods. A 7-day block average is also consistent with the existing State operating
permit requirements for Plant A.
4.3 MONITORING OPTIONS
The applicable monitoring approach for any operation or facility depends on the control
technology used to meet the applicable emission limit. For processes with control devices, often
called add-on control devices, monitoring approaches will include continuous emission
monitoring systems and operating parameter monitoring devices, used in combination with regular
maintenance and corrective action as indicated. For other processes, improved recordkeeping and
repc.ting of pollution control activities may be sufficient.
The general approach to selecting monitoring options begins with identifying the emission units
and pollutants that are likely to be regulated. The emission units likely to be regulated under the
current regulatory approach for the friction materials manufacturing NESHAP are solvent mixers.
The pollutants to be regulated from these emission units are organic HAP, including n-hexane,
trichloroethylene, and toluene.
4-9
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Continuous monitoring of the regulated pollutants or surrogate pollutants is not recommended as a
means of ensuring continuous compliance with the HAP solvent recovery emission standard.
Neither of these monitoring options provides a means to measure, directly or indirectly, the solvent
recovery efficiency.
Continuous monitoring of selected control device operating parameters allows for real-time
*
measurements of parameters that generally are reliable indicators of control device performance.
The costs of monitoring control device operating parameters are reasonable. The parameter used
most often as an indicator of condenser performance is outlet gas temperature. For carbon
%
adsorbers, the parameters typically monitored include regeneration cycle frequency and steam
flow. The drawback to this option is that it does not provide adequate information to ensure
compliance with the solvent recovery standard, considering variations in the quantity of solvent
added to batches of different product mixes, variations in the amount of solvent remaining in
different products, and variations in the amount of solvent collected by the system.
For solvent recovery systems (e.g., carbon adsorbers and condensers), monitoring of solvent usage
and solvent recovered for each batch allows for measurement of actual solvent recovery
efficiency. The costs of monitoring these parameters are reasonable. For the proposed standard,
this would include monitoring the quantity of solvent introduced into the solvent mixer and the
quantity of solvent recovered by the solvent recovery system.
4.4 REFERENCES
1. Memorandum from Bullock, D., Midwest Research Institute, to Cavender, K., ESD/MG.
Site Visit Report-Plant A.
2. U. S. Environmental Protection Agency. Toxics Release Inventory for Reporting Year
1997 for Plant A.
3. Air Pollution Control Construction and Operation Permits for Plant A.
4. Memorandum from Bullock, D. and Turner, M., Midwest Research Institute, to Zapata, S.,
ESD/MICG. Site Visit Report-Plant B.
4-10
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5. U. S. Environmental Protection Agency. Toxics Release Inventory for Reporting Year
1998 for Plant B.
6. Memorandum from Schmitt, D., Bullock, D., and Abraczinskas, M., Midwest Research
Institute, to Cavender, K., ESD/MG. Site Visit Report-Plant B.
7. Telecon. Bullock, D. and Abraczinskas, M., Midwest Research Institute, with
representative of Plant B. Solvent recovery process at Plant B.
8. Informatiou from Plant B to Abraczinskas, M., Midwest Research Institute. Solvent
recovery process at Plant B.
9. Memorandum from Schmitt, D. and Turner, M., Midwest Research Institute, to Zapata, S.,
ESD/MICG. Site Visit Report-Plant C.
10. U. S. Environmental Protection Agency. Toxics Release Inventory for Reporting Year
1998 for Plant C.
11. Emission test report for Plant C.
12. Completed information collection request for Plant D.
13. U. S. Environmental Protection Agency. Toxics Release Inventory for Reporting Year
1998 for Plant D.
4-11
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Chapter 5
Model Process Unit
This chapter describes the development of the model process unit for solvent mixers in the friction
t
materials manufacturing industry. The model process unit is designed to be representative of
solvent mixers found at friction materials manufacturing facilities and is used by EPA to estimate
industry-wide environmental and energy impacts, and costs of control options. These impacts and
costs are presented in Chapters 6 and 7, respectively.
Most of the information used in developing the model process unit comes from site visit reports for
three of the four facilities.1"3 This information has been supplemented by information from other
sources, including emission test reports and discussions with industry representatives.4"7
5.1 GENERAL APPROACH
The model process unit exhaust stream parameters that are required for the cost analysis include
the exhaust gas volumetric flow rate, exhaust gas temperature, and pollutant concentration in the
exhaust gas stream. Generally, multiple sizes of models are developed (e.g., small, medium, and
large) to represent the process units. The small population of solvent mixers in the friction
materials manufacturing industry and the limited data available do not support developing multiple
models for solvent mixers. Therefore, one solvent mixer model was developed. Also, because of
the limited available data, a simple approach was taken in choosing the model process unit exhaust
stream parameters. For parameters where only a single data point was available (e.g., pollutant
concentration in the exhaust stream), the single data point was used for the model process unit. For
parameters where multiple data points were available (e.g., exhaust gas flow rate and exhaust gas
temperature), the arithmetic average of the data points (rounded to two significant figures) was
used to represent the model process unit parameters.
5-1
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A model process unit was developed only for solvent mixers; no other models were developed
because no other emission units will be regulated under the proposed standard for friction
materials manufacturing. The model solvent mixer is characterized by the stack gas parameters
mentioned above, and VOC concentration. The VOC concentration is used as a surrogate for the
organic HAP concentration because actual HAP concentration data are not available. Section 5.2
i,
describes the development of the model solvent mixer. Chapter 2 describes solvent mixers in
more detail.
5.2 SOLVENT MIXERS
There are seven solvent mixers in operation at the four friction materials manufacturing facilities
estimated to be major sources. Of these four facilities, one facility operates four solvent mixers,
and the other three facilities operate a single solvent mixer each. The HAPs emitted from solvent
mixers include n-hexane, toluene, and trichloroethylene. Based on available data, a given facility
uses only one of these three solvents. Therefore, emissions from any single solvent mixer would
include only one of the above compounds.
The controlled solvent mixers for which data are available are controlled by dedicated solvent
recovery systems (i.e., one solvent recovery system for one mixer). The solvent mixers that
represent the MACT floor and beyond-the-floor are each characterized as having a closed-vent
system with a low-volume, high-concentration exhaust stream ducted to a condenser. It is assumed
that the four existing uncontrolled solvent mixers will be enclosed in order to vent emissions to a
condenser. The solvent mixer model process unit has been developed to reflect this application.
Table 5-1 presents the limited available data for closed-vent solvent mixer exhaust parameters.
Because inlet concentration data were available for only one of the solvents used, Antoine's
equation was used to calculate the inlet concentrations for the three solvents at the model
temperature, assuming a saturated stream.8 As a check of the reasonableness of assuming a
saturated stream, Antoine's equation was also used to calculate the inlet concentration for the one
facility where an inlet value was available. Using the actual temperature of that stream, the
calculated inlet concentration is within approximately 10 percent of the actual value.
5-2
-------
Table 5-1. Exhaust Stream Characteristics for Closed-Vent Solvent Mixer Systems
Facility
Plant A
Plant B
Average:
Flow rate
(dscfm)
50
39
45
Exhaust stream
temperature (°F)
145
110
128
VOC concentration
(ppm)
456,206
456,206
Table 5-2 presents a summary of the model process unit exhaust parameters for closed-vent
solvent mixers based on the data in Table 5-1 and the calculated inlet concentrations for each
solvent.
Table 5-2. Model Process Unit Exhaust Parameters for Closed-Vent Solvent Mixer Systems
Parameter
Flow rate (dscfm)
Exhaust stream temperature (°F)
Calculated volume fraction of solvent in the exhaust stream at
saturation:3
n-hexane
trichloroethylene
toluene
Model Process Unit Value
45
130
0.62
0.33
0.15
Volume fractions are for exhaust streams containing only one of the listed compounds. Based on available data.
a given mixer uses only one of the three listed solvents.
5.2 REFERENCES
1. Memorandum from Bullock, D., Midwest Research Institute, to Cavender, K., ESD/MG.
Site Visit Report-Plant A.
2. Memorandum from Bullock, D. and Turner, M., Midwest Research Institute, to Zapata, S.,
ESD/MICG. Site Visit Report-Plant B.
3. Memorandum from Schmitt, D. and Turner, M., Midwest Research Institute, to Zapata, S.,
ESD/MICG. Site Visit Report- Plant C.
4. Telecon. Bullock, D. and Abraczinskas, M., Midwest Research Institute, with
representative of Plant A. Solvent mixer and condenser system.
5-3
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5. Telecon. Bullock, D. and Abraczinskas, M., Midwest Research Institute, with
representative of Plant A. Solvent mixer condenser system and mixing process.
6. Telecon. Bullock, D. and Abraczinskas, M., Midwest Research Institute, with
representative of Plant B. Solvent mixer and recovery system.
7. Telecon. Abraczinskas, M., Midwest Research Institute, with representative of Plant C.
Solvent mixing process.
8. Memorandum from Randall, D., Midwest Research Institute, to project file. Volume
Fraction of Solvents. October 19, 2000.
5-4
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Chapter 6
Environmental and Energy Impacts
This chapter presents the environmental and energy impacts associated with controlling HAP
emissions from solvent mixers in the friction materials manufacturing source category.
Environmental impacts include primary and secondary air pollution impacts, water impacts, and
solid waste impacts, while energy impacts include electricity requirements. Environmental and
energy impacts were estimated for the control technique (solvent recovery system) likely to be
used to control emissions to the MACT floor and beyond-the-floor control levels for solvent
mixers.
Four friction materials manufacturing facilities were included in the MACT floor and beyond-the-
floor analyses. The potential and baseline HAP emissions and characterization of HAP emission
sources are provided in Chapter 2. The MACT floor and beyond-the-floor control options for
existing and new solvent mixers are provided in Chapter 4. The development of the model
process unit is described in Chapter 5. The emission estimation approach is described in
Appendix B.
This chapter contains seven sections. Section 6.1 discusses the basis for the environmental and
energy impacts analysis. Section 6.2 discusses the primary air pollution impacts. Section 6.3
discusses the secondary air pollution impacts. Section 6.4 discusses the water pollution impacts.
Section 6.5 discusses the solid waste disposal impacts. Section 6.6 discusses the energy impacts.
Section 6.7 provides a list of references.
6-1
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6.1 BASIS FOR IMPACTS ANALYSIS
This environmental and energy impacts analysis assumes that solvent mixers will be retrofitted
with condensers to control HAP emissions. This assumption is based on control techniques
demonstrated by friction materials manufacturing facilities. For the purposes of this analysis, it is
assumed that the four existing uncontrolled solvent mixers will be retrofitted with condensers in
older to meet the MACT floor and beyond-the-floor levels. It is also assumed that one existing
solvent mixer cuncntly controlled to the MACT floor level of 70 percent will have to install a
more efficient condenser to meet the beyond-the-floor level of 85 percent. This analysis also
assumes that multiple solvent mixers will not share a condenser.
Data on the number of motor vehicles in use and locomotives and railcars in use> were used to
project the change in the demand for friction materials over the next 5 years (i.e., from 2001 to
2006).' Based on the available data, an 8 percent increase in motor vehicles, locomotives, and
railcars in use is expected over the next 5 years. This increase is believed to be indicative of a
similar increase in the demand for friction materials. The annual growth rate in friction materials
sales over the next 5 years is estimated to be approximately 14 percent.1 The number of new
solvent mixers is assumed to correlate to the increase in friction materials production and sales.
Because the overall average production capacity utilization for the friction materials manufacturing
industry is approximately 50 percent, the current industry capacity is more than sufficient to meet
the increased demand. Therefore, it is projected that no new solvent mixers will be installed.
6,2 PRIMARY AIR POLLUTION IMPACTS
Primary air pollution impacts consist of the reduction of n-hexane and toluene emissions relative to
the baseline level directly attributable to the implementation of the control options. (No reduction
in trichloroethylene [TCE] emissions is expected at the MACT floor or beyond the floor because
the facility using this solvent is already in compliance with the beyond-the-floor control option.)
The MACT floor control option is estimated to reduce HAP emissions from existing friction
materials manufacturing facilities by approximately 200 tpy, or 31 percent, from a baseline HAP
emission level of approximately 640 tpy. The beyond-the-floor control option is estimated to
reduce HAP emissions by approximately 310 tpy, or 49 percent, relative to the baseline level. A
6-2
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summary of the primary air impacts associated with implementation of the MACT floor and
beyond-the-floor control options is shown in Table 6-1.
Table 6-1. Nationwide Primary Air Impacts for Existing Friction Materials
Manufacturing Facilities
Control level
MACT floor
Beyond the floor
Pollutant
n-Hexane
Toluene
TCE
Total HAP
n-Hexane
Toluene
TCE
Total HAP
Emissions, tpy3
Baseline
560
63
18
640
560
63
18
L_ 640
Post-MACT
380
36
18
440
280
30
18
330
Emission
reduction, tpy
170
27
0
200
280
33
0
310
Percent
reduction
31%
56%
0%
31%
50%
68%
0%
49%
a The baseline emissions are based on emissions from the four facilities estimated to be major sources and
equipped with HAP solvent mixers.
6.3 SECONDARY AIR POLLUTION IMPACTS
Secondary air pollution impacts consist of any adverse or beneficial air impacts other than the
primary air impacts described in Section 6.2. The secondary impacts are impacts that result from
the operation of any new or additional add-on control devices (e.g., condensers).
Secondary air impacts consist of: (1) byproducts generated from the fuel combustion necessary to
generate the electricity required to operate the control devices, and (2) VOC emissions reduced
due to the implementation of the control options. The estimated electricity requirements are
described in Section 6.6. The electricity is assumed to be generated at coal-fired utility plants
built since 1978. These plants are subject to the new source performance standards (NSPS) in
subpart Da of 40 CFR part 60. These NSPS emission limits were used to estimate secondary
emissions of sulfur dioxide (SO2), nitrogen oxides (NOX), and PM with an aerodynamic diameter
at or below 10 micrometers (PM10) from coal combustion.
6-3
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Because carbon monoxide (CO) emissions are not covered by the NSPS, the CO emission factor
for bituminous/subbituminous coal combustion from the AP-42 was used to estimate the CO
secondary emissions. The CO secondary emissions were estimated-assuming an average heating
value of 14,000 British thermal units per pound (Btu/lb) of bituminous/subbituminous coal.
A*summary of the estimated secondary air impacts is presented in Table 6-2. It is estimated that
the MACT floor control option will increase byproduct emissions from fuel combustion from
utility plants by less than 0.3 tpy, while the beyond-the-floor control option will increase
byproduct emissions by less than 0.5 tpy.t
Table 6-2. Nationwide Secondary Air and Energy Impacts for
Existing Friction Materials Manufacturing Facilities
Control level
MACT floor
Beyond the
floor
Model
Solvent mixers (n-
hexane)
Solvent mixers
(toluene)
Solvent mixer
(TCE)
Total
Solvent mixers (n-
hexane)
Solvent mixers
(toluene)
Solvent mixer
(TCE)
Total
Increased emissions, tpy"
S02
0.17
0.018
0
0.18
0.29
0.024
0
0.32
NOX
0.069
0.0074
0
0.076
0.12
0.0099
0
0.13
PM10
0.0041
0.0004
0
0.0046
0.0073
0.0006
0
0.0079
CO
0.0025
0.0003
0
0.0027
0.0044
0.0004
0
0.0047
Increased
electricity,
MMBtu/yr
280
30
0
300
490
39
0
530
a The SO2, NOX, and PM10 emissions were estimated using the NSPS emission limits of 1.2 Ib SO2, 0.5 Ib NOX,
and 0.03 Ib PM10 per MMBtu fuel input for coal-fired utility plants. The CO emissions were estimated using the
AP-42 emission factor of 0.5 Ib CO/ton of coal '"or bituminous and subbituminous coal combustion.
In addition to the generation of byproduct emissions from fuel combustion, secondary air impacts
also include the reduction of VOC emissions from the implementation of the control options. The
VOC compounds are precursors to tropospheric ozone formation. Emissions of VOC will be
reduced by approximately 200 tpy at the MACT floor and 310 tpy beyond the floor. These VOC
6-4
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emission reductions are identical to the primary organic HAP emission reductions because the
organic HAP reduced by the control options are also classified as VOC.
6.4 WATER POLLUTION IMPACTS
Friction materials manufacturing facilities impacted at the MACT floor or beyond the floor are
expected to install condensers with glycol rather than chilled water as the cooling medium.
*;
Therefore, no water pollution impacts are expected with the implementation of either the MACT
floor or beyond-the-floor option.
6.5 SOLID WASTE DISPOSAL IMPACTS
Friction materials manufacturing facilities impacted at the MACT floor or beyond the floor are
expected to install condensers to comply with the control options. Because condensers do not
generate solid waste, no solid waste disposal impacts are expected with the implementation of
either the MACT floor or beyond-the-floor option.
6.6 ENERGY IMPACTS
Energy impacts consist of the electricity required to operate the control devices (condensers) used
to comply with the control options. As noted in section 6.3, electricity is assumed to be generated
in coal-fired boilers at utility plants. The amount of fuel energy required to generate the electricity
was estimated using a heating value of 14,000 Btu/lb of coal and a utility plant efficiency of 35
percent. The electricity requirements were estimated by dividing the electricity costs for each of
the control devices by the unit cost for electricity ($0.06 per kilowatt-hour [kWh]) used in the cost
analyses, converting to million British thermal units (MMBtu), and multiplying by the number of
impacted units for each model process unit. Table 6-2 presents the annual electricity impacts
associated with operating the control devices. The overall energy demand (i.e., electricity) is
expected to increase by approximately 300 MMBtu/yr nationwide at the MACT floor and 530
MMBtu/yr beyond the floor.
6.7 REFERENCES
1. Memorandum from Bullock, D., Midwest Research Institute, to project file. May 17, 2001.
New Source Projections for the Friction Materials NESHAP.
6-5
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Chapter 7
Cost of Controls
This chapter presents the estimated costs associated with controlling HAP emissions from solvent
t
mixers in the friction materials manufacturing source category. Costs were estimated for the
control technique likely to be used to control emissions to the MACT floor and beyond-the-floor
control levels for solvent mixers, as well as for testing, monitoring, reporting, and recordkeeping
requirements.
Four friction materials manufacturing facilities were included in the MACT floor and beyond-the-
floor analyses. The MACT floor and beyond-the-floor control options for existing and new
solvent mixers are provided in Chapter 4. The development of the model process unit is described
in Chapter 5. In addition, estimates of baseline emissions and emission reductions achieved under
the MACT floor and beyond-the-floor control options are provided in Chapter 6.
This chapter contains eight sections. Section 7.1 discusses the basis for the control cost analysis.
Section 7.2 discusses the estimated control device costs. Section 7.3 discusses the costs
associated with initial compliance (performance tests and compliance demonstrations).
Section 7.4 discusses the estimated monitoring costs. Section 7.5 discusses the estimated
repc :ing and recordkeeping costs. Section 7.6 discusses the cost effectiveness of the MACT floor
and beyond-the-floor control options. Section 7.7 discusses the estimated number of new sources.
Section 7.8 discusses the estimated cost impacts on small businesses. Section 7.9 provides a list
of references.
7-1
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7.1 BASIS FOR CONTROL COST ANALYSIS
The controlled solvent mixers for which data are available are controlled by dedicated solvent
recovery systems (e.g., one condenser or carbon adsorber per mixer). The solvent mixers that
represent MACT floor and beyond-the-floor control are enclosed (i.e., sealed and under vacuum)
and have low-volume, high-concentration exhaust streams controlled with a condenser. In order to
rn^et the MACT floor and beyond-the-floor control levels, it is assumed that the four uncontrolled
solvent mixers will be enclosed in order tcrvent emissions to a comparable solvent recovery
system (e.g., a condenser). The solvent mixer model process unit has been developed to reflect
this application. It is also assumed that one existing solvent mixer currently controlled to the
MACT floor level of 70 percent will have to install a more efficient condenser to meet the
beyond-the-floor level of 85 percent.
A condenser is the likely choice for the low-volume, high-concentration exhaust stream
represented by the model. For applications having a high-volume, low-concentration exhaust
stream (i.e., solvent mixers that are not enclosed), a carbon adsorber may be a viable option.
The control cost algorithm for the condenser is based on the control cost algorithm developed by
EPA's Office of Air Quality Planning and Standards (OAQPS).1 The assumptions and data used in
the algorithm were generated following guidelines in the OAQPS Control Cost Manual. The
refrigeration unit size (tons of cooling) is based on an energy balance around the unit when the
process is venting and the inlet stream contains its maximum HAP load. Costs were developed for
single-stage refrigeration units using the approach in the OAQPS Control Cost Manual.
The purchased equipment cost (PEC) for the refrigeration system is equal to the total equipment
cost plus 18 percent for instrumentation, sales tax, and freight. The installation cost for the
refrigeration system includes both direct and indirect installation costs. The direct installation
cost for the refrigeration system is equal to the PEC for the system plus 43 percent for foundations
and supports, handling and erection, electrical installation, piping installation, insulation for
ductwork, and painting. The indirect installation cost for the refrigeration system is equal to the
PEC for the system plus 31 percent for engineering, construction and field expenses, contractor
fees, start-up, performance test, and contingencies.
7-2
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The total capital cost is equal to the sum of the PEC for the refrigeration system, direct and indirect
installation costs of the refrigeration system. In estimating the total capital cost for control device
equipment, the equipment costs were based on data from various years and were scaled to
represent costs in December 2000 dollars.
The total annual c^st for the condenser consists of direct annual costs, indirect annual costs, and
recovery credits. Direct annual costs are costs for labor, maintenance materials, and electricity.--
Indirect annual costs are-costs for overhead, administrative charges, property taxes, insurance, and
%
capital recovery. Recovery credits are credits for the value of the recovered solvent and represent
the savings due to reduced solvent purchases. The unit costs and other factors used to estimate
these costs and credits are given in Table 7-1.
Table 7-1. Assumptions for Annual Cost Calculations
Direct annual costs
Operator labor wage rate
Maintenance labor wage rate
Supervisor labor cost
Maintenance materials cost
Maintenance labor requirements
Electricity unit cost
$19.72 per hour, based on December 2000 wage rate for
Manufacturing: Transportation Equipment (Monthly
Labor Review, Bureau of Labor Statistics)
$21 .69 per hour, based on 1 10 percent of operator labor
wage rate
15 percent of operator labor cost
100 percent of maintenance labor cost
0.5 hour per 8-hour operation
$0.06 per kWh
Indirect annual costs
Overhead
Administrative changes, property
taxes, and insurance
Capital recovery (condenser)
60 percent of all labor and maintenance material costs
4 percent of total capital cost
Capital recovery factor (CRF) times the total capital
cost. The CRF is 0.1098, based on a 15-year equipment
life and 7 percent interest rate.
Recovery credits
n-Hexane
Toluene
$0.26 per Ib
$0.28 per Ib
7-3
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Electricity requirements for the refrigeration unit were estimated using the tabulated data in the
OAQPS Control Cost Manual. Linear regression was used to develop an equation for electricity
requirements per ton of cooling as a function of the condenser temperature. The mechanical
efficiency of the compressor was estimated to be 85 percent. Electricity requirements for pumps
and blowers were considered to be negligible relative to the requirements for the refrigeration
*..
unit.
7.2 CONTROL DEVICE COSTS
%
Table 7-2 presents a summary of the estimated capital and annual control costs for condensers
installed on individual solvent mixers. Annual costs are presented without recovery credits.
Separate costs are presented for systems recovering toluene and n-hexane and for the MACT floor
and beyond-the-floor control requirements. Total facility control costs were estimated assuming
that separate recovery systems will be installed for each solvent mixer.
Table 7-2. Control Costs for Condensers Installed on Individual Solvent Mixers
Control level
MACT floorb
Beyond the floor0
Solvent used
n-Hexane
Toluene
n-Hexane
Toluene
Capita] cost, $
$39,000
$28,000
$50,000
$37,000
Annual cost, $/yeara
$19,000
$16,000
$21,000
$18,000
a Annual costs do not include solvent recovery credits.
b Condenser costs were estimated at 74 percent efficiency to achieve MACT floor level of 70 percent recovery.
c Condenser costs were estimated at 90 percent efficiency to achieve beyond-the-floor level of 85 percent
recovery.
The total capital control costs for the industry are estimated to be approximately $150,000 at the
MACT floor and $240,000 beyond the floor. The total annual control costs for the industry,
without recovery credits, are estimated to be approximately $72,000 at the MACT floor and
$100,000 beyond the floor. The total annual control costs for the industry, including recovery'
credits, are estimated to be net credits of approximately $33,000 at the MACT floor and $62,000
beyond the floor.2
7-4
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7.3 INITIAL COMPLIANCE COSTS
No performance testing would be required under the NESHAP for friction materials
manufacturing. Therefore, there are no costs associated with performance testing. However, an
initial compliance demonstration would be required under the friction materials manufacturing
NESHAP. The initial compliance demonstration would consist of monitoring and recording the
weight of HAP solvent delivered into each solvent mixer and recovered from each mix batch over
the first 7 consecutive days after the compliance date. Because this is also a monitoring activity,
the costs associated with the initial compliance demonstration are included in the monitoring costs
presented in the following section. ,
7.4 MONITORING COSTS
The friction materials manufacturing NESHAP would include requirements for monitoring and
recording the weight of HAP solvent delivered into solvent mixers and recovered from each mix
batch. Capital costs include costs for an industrial floor scale system to weigh the solvent loaded
into and recovered from the mixer, digital meter, installation, taxes, and freight. The total capital
cost for a scale system is estimated to be approximately $2,100.3 Annual costs include costs for
operating and maintenance labor, maintenance materials and supplies, taxes, insurance,
administrative charges, and capital recovery. The total annual cost for a scale system is estimated
to be approximately $3,700.3 Facility monitoring costs were estimated assuming that separate
scale systems will be installed and operated for each solvent mixer. Total capital monitoring
costs for the industry are estimated to be approximately $13,000 and total annual monitoring costs
are estimated to be approximately $22,000, both at the MACT floor and beyond the floor.2
7.5 REPORTING AND RECORDKEEPING COSTS
The proposed friction materials manufacturing NESHAP includes requirements for reporting and
recordkeeping. Capital reporting and recordkeeping costs include costs for file cabinets for
storing records. The total capital cost for the industry is estimated to be $940.2 Annual reporting
and recordkeeping costs include labor costs for reporting and recordkeeping, annualized capital
costs for the file cabinets, and operation and maintenance costs for photocopying and postage
associated with the reporting requirements. The total annual cost for the industry is estimated to be
7-5
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approximately $80,000.2 These costs do not include costs associated with monitoring, which are
discussed in the previous section.
7.6 COST EFFECTIVENESS
The cost effectiveness of the MACT floor and beyond-the-floor control options for friction
materials manufacturing is estimated as the total annual cost of the control option (control cost,
monitoring cost, and reporting and recordkeeping cost) divided by the amount (tpy) of HAP
recovered, which yields a cost per ton of HAP recovered. Table 7-3 presents the total HAP
emission reduction, total-annual costs, and the associated cost effectiveness. The cost
%
effectiveness of controlling HAP solvent emissions from existing solvent mixers at major sources,
without recovery credits, is estimated to be approximately $890/ton at the MACT floor and
$660/ton beyond the floor. The cost effectiveness of controlling HAP solvent emissions from
existing solvent mixers at major sources, including recovery credits, is estimated to be
approximately $360/ton at the MACT floor and $140/ton beyond the floor.
Table 7-3. Nationwide Cost-effectiveness for Existing
Friction Materials Manufacturing Facilities
Control level
MACT floor
Beyond the floor
Incremental
Nationwide annual cost, $/yr
Without
credits
$180,000
$210,000
$29,000
With
credits
$72,000
$43,000
($29,000)
Emission
reduction from
baseline, tpy
200
310
110
Cost effectiveness, $/ton
Without
credits
$890
$660
$260
With
credits
$360
$140
($260)
The incremental cost effectiveness of going from the MACT floor to beyond the floor for friction
materials manufacturing is estimated as the difference in the annual cost of the control options
divided by the difference in the number of tons of HAP recovered, which yields an incremental
cost per ton of HAP recovered. Table 7-3 presents the incremental HAP emission reduction,
incremental total annual cost, and the associated incremental cost effectiveness. The incremental
cost effectiveness of going from the MACT floor to beyond the floor is estimated to be
approximately $260/ton, without recovery credits, and a net credit of approximately $260/ton,
with recovery credits.
7-6
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7.7 NEW SOURCES
Data on the number of motor vehicles in use and locomotives and railcars in use were used to
project the change in the demand for friction materials over the next 5 years (i.e., from 2001 to
2006).3 Based on the available data, an 8 percent increase in motor vehicles, locomotives, and
railcars in use is expected over the next 5 years. This increase is believed to be indicative of a
similar increase in the demand for friction materials. The annual growth rate in friction materials
sales over the next 5 years is estimated to be approximately 14 percent.3 The number of new
solvent mixers is assumed to correlate to the increase in friction materials production and sales.
Because the overall average production capacity utilization for the friction materials industry is
«
approximately 50 percent, the current industry capacity is more than sufficient to meet the
increased demand. Therefore, it is projected that no new solvent mixers will be installed.
Consequently, there are no costs associated with new solvent mixers.
7.8 SMALL BUSINESSES
One small business is included in the population of facilities used for evaluating and determining
the MACT floor and beyond-the-floor control levels. This facility is estimated to be a major
source of HAP emissions and will have to meet the requirements of the friction materials
manufacturing NESHAP. This facility already has a solvent recovery system (condenser) in place
that can meet both the MACT floor and beyond-the-floor control levels. In addition, this facility
has the necessary monitoring equipment in place. The total annual cost for this facility is estimated
to be approximately $21,000, which is comprised entirely of reporting and recordkeeping costs.
7.9 REFERENCES
1. U. S. Environmental Protection Agency. OAQPS Control Cost Manual. Fifth Edition.
EP A/45 3/B-96-001. February'1996. Chapters. Refrigerated Condensers.
2. Memorandum from Bullock, D., Hanks, K., and Holloway, T., Midwest Research Institute,
to project file. July 24, 2001. Facility-Specific Costs for the Friction Materials
Manufacturing Industry.
3. Memorandum from Hanks, K., Midwest Research Institute, to project file. May 17, 2001.
Monitoring Costs for the Friction Materials Manufacturing NESHAP.
7-7
-------
4. Memorandum from Bullock, D., Midwest Research Institute, to project file. May 17, 2001.
New Source Projections for the Friction Materials Manufacturing NESHAP.
7-8
-------
Appendix A
Evolution of the Standard
This appendix summarizes the background information gathered and the analyses performed during
the development of the friction materials manufacturing standard. In developing the standard, the
following technical data were acquired from the friction materials manufacturing industry:
(1) equipment design and operating parameters, (2) types and quantities of HAP emitted, (3)
emission reduction techniques, and (4) the effectiveness of these control techniques in reducing
HAP emissions. The bulk of the information was gathered from the following sources:
1. Technical literature;
2. Industry representatives;
3. Site visit reports;
4. ICRs;
5. State and local air pollution control agencies; and
4. Emission test reports.
Significant events relating to the evolution of the friction materials-manufacturing standard
are listed in Table A-l.
Table A-l. Evolution of the Standard
Date
4/1/97
4/3/97
4/24/97
4/25/97
5/1/97
6/11/97 '
Event
Draft memo summarizing existing friction products information submitted to EPA
Site visit to Stone Heavy Vehicle Specialists, Inc., Raleigh, North Carolina
Site visit to Quality Automotive Co., Tappahannock, Virginia
Site visit to VAAPCO, Inc., Millers Tavern, Virginia
Site visit to The Hastings Co., King, North Carolina
Final site visit reports for Stone Heavy Vehicle Specialists. Inc.. Raleigh. North Carolina and
The Hastings Co., King, North Carolina
A-l
-------
Table A-1. (continued)
Date
6/24/97
8/27/97
9/4/97
9/23/97
11/7/97
12/12/97
1/2/98
1/16/98
2/27/98
3/12/98
5/7/98
5/11/98
6/18/98
7/22/98
7/30/98
8/4/98
8/25/98
8/27/98
10/8/98
10/21/98
12/11/98
12/11/98 .
1/19/99
2/8/99
Event
Meeting with representatives of the friction products industry to discuss the friction products
MACT standards development project, including draft ICR
Draft memo comparing generic ICR questionnaire with friction products ICR questionnaire
submitted to EPA
Final site visit report for VAAPCO, Inc., Millers Tavern, Virginia
Site visit to Performance Friction Corp., Clover, South Carolina
ICR questionnaires mailed out to friction products industry (responses due 60 days after
mailout)
First site visit to Railroad Friction Products Corp., Laurinburg, North Carolina
Final site visit report for Performance Friction Corp., Clover, South Carolina
Data base created to tabulate information in the ICR responses; responses (ICRs,
delay/exlension letters, not applicable letters) received for over 50 percent of mailouts by
deadline; updated docket index submitted to EPA
Memo describing current plans for emission testing at friction products facilities submitted to
EPA
Updated docket index submitted to EPA
Updated docket index submitted to EPA
Final site visit report for Quality Automotive Co., Tappahannock, Virginia
Updated docket index submitted to EPA
-Site visit to BF Goodrich Aerospace, Pueblo, Colorado
Updated docket index submitted to EPA
Site visit to Federal-Mogul, Smithville, Tennessee
Final site visit report for first trip to Railroad Friction Products Corp., Laurinburg, North
Carolina
All expected ICR responses/clarifications (97 percent) received; updated docket index
submitted to EPA
Updated docket index submitted to EPA
Site visit to Raybestos Products Co., Crawfordsville, Indiana
Data entry of ICR responses complete (about 90 percent of available data sets); poor ICR
responses (about 10 percent) not entered
Updated docket index submitted to EPA
Final site visit report for Raybestos Products Co., Crawfordsville, Indiana
Friction products National Toxics Inventory (NTI) template submitted to EPA
A-2
-------
Table A-1. (continued)
Date
7/8/99
3/14/00
3/8/00
3/17/00
4/5/00
4/13/00
4/19/00
4/26/00
5/31/00
6/13/00
6/30/00
7/13/00
8/17/00
10/26/00
11/9/00
11/14/00
11/16/00
12/22/00
1/16/01
2/6/01
3/27/01
4/17/01
4/27/01
5/8/01
5/10/01
6/11/01
Event
Updated friction products NTI template submitted to EPA
Second site visit to Railroad Friction Products Corp., Laurinburg, North Carolina
Draft BID Chapter 1 (Introduction) submitted to EPA
Draft outline of BID submitted to EPA
Draft BID Chapter 2 (Industry Profile) submitted to EPA
\
Meeting with EPA to review MACT floors
Final site visit report for BF Goodrich Aerospace, Pueblo, Colorado
Draft BID Chapter 3 (Emission Control Techniques) submitted to EPA
Draft BID Chapter 4 (MACT Floors and Regulatory Options) submitted to EPA
Meeting with EPA to review model process units; draft Appendix B to BID (Emission
Estimation Methodology) submitted to EPA
Draft BID Chapter 5 (Model Process Units) submitted to EPA
Meeting with EPA to discuss economics-related issues for friction products MACT standard
Drafts of BID Chapters 6 (Environmental and Energy Impacts) and 7 (Cost of Controls)
submitted to EPA
Draft proposal regulation submitted to EPA
Site visit to Thermoset, Inc., Jackson, Wisconsin
Non-CBI test report summary submitted to EPA for review by facilities
Meeting with representatives of the friction products industry to update the industry on the
status of the friction products MACT standards development project
Draft proposal preamble submitted to EPA
Draft new source projections memo submitted to EPA; draft monitoring costs memo submitted
to EPA
Draft memo transmitting facility-specific cost estimates submitted to EPA/ISEG; draft OMB
83-1 and supporting statement submitted to EPA
Final site visit report for Thermoset, Inc., Jackson, Wisconsin
Final site visit report for second trip to Railroad Friction Products Corp., Laurinburg, North
Carolina
Final site visit report for Federal-Mogul, Smithville, Tennessee
Final facility-specific cost estimates submitted to EPA
Final OMB 83-1 and supporting statement submitted to EPA
Revised draft BID Chapters 1-7 and Appendices A and B submitted to EPA
A-3
-------
Table A-1. (continued)
Date
8/3/01
Event
Final draft BID submitted to EPA
A-4
-------
Appendix B
Emission Estimation Methodology
This appendix presents the methodologies used in estimating HAP emissions from facilities in the
friction materials manufacturing industry. The methodologies for estimating uncontrolled and
controlled emissions are presented, as well as the methodologies for estimating emissions
associated with the MACT floor and beyond-the-floor options. The emissions estimates are
presented in Tables B-l through B-4 below. Emissions were estimated for the four friction
materials manufacturing facilities (Plants A, B, C, and D) with resin-based processes that are
major sources of HAP emissions. Sections B.I through B.4 present the emission estimation
methodologies for these four facilities. Section B.5 provides a list of references.
B.I Plant A
B.I.I Baseline and Uncontrolled Emissions
Uncontrolled emissions from Plant A were determined based on the annual consumption of toluene
solvent, assuming that the quantity of solvent consumed is equal to the quantity of solvent emitted.
According to the ICR response for Plant A, the annual consumption of toluene solvent for 1997
was expected to be 13,085 gal, and the HAP content of the solvent is 100 percent; this is
equivalent to an annual consumption of 46.98 tpy for toluene, based on a reported density of 7.18
lb/gal.5 Therefore, the total uncontrolled emissions for Plant A were estimated to be 46.98 tpy.
Using the equipment ratios from Plant B as a model (80.5 percent from solvent mixer, 10.5 percent
from extruder, 7.2 percent from granulator, 1.6 percent from dryers, and 0.2 percent from hot
presses), &0.5 percent of the uncontrolled emissions at Plant A were assumed to be from the
solvent mixer, and 10.5 percent were assumed to be from the extruder. Emissions from the oven
B-l
-------
were assumed to be equivalent to the remainder of the emissions (9.0 percent). Therefore, the
uncontrolled emissions for the solvent mixer were estimated to be 0.805 * 46.98 tpy = 37.82 tpy,
while the uncontrolled emissions for the rest of the solvent mixer line (extruder and oven) were
estimated to be 0.195 * 46.98 tpy = 9.16 tpy.
Baseline emissions for the solvent mixer were estimated based on the effectiveness of the vacuum
*-;
system used to capture and collect the toluene solvent and the control efficiency of the condenser
used to recover the toluene solvent. Based on the available data, Plant A's vacuum system
captures 95 percent of the toluene from the solvent mixer, and the condenser recovers 90 percent
i
of the captured solvent vapor, resulting in an overall solvent recovery of 85 percent, which the
facility has consistently achieved.6 Therefore, baseline emissions for the solvent mixer were
estimated to be 0.15 * 37.8*2 tpy = 5.67 tpy. Because the rest of the solvent mixer line (extruder
and oven) is uncontrolled, the emissions from these pieces of equipment would remain unchanged
(9.16 tpy).
B.I.2 MACT Floor and Beyond-the-Floor Emissions
The MACT floor and beyond-the-floor emissions for Plant A would be identical to baseline
emissions because the solvent mixer at this facility already achieves 85 percent solvent recovery.
Therefore, this solvent mixer is not impacted at the MACT floor and beyond-the-floor.
B.2 PlantB
B.2.1 Baseline and Uncontrolled Emissions
Baseline emissions from Plant B were determined based on the quantity of hexane solvent
purchased, assuming that the quantity of solvent purchased is equal to the quantity of solvent
emitted. According to the response to the ICR for Plant B, the annual purchase of hexane solvent
for 1997 was expected to be 317,914 gallons (gal), and the n-hexane content of the solvent
purchased was 62.3 percent.1 Using a reported density of 5.619 pounds per gallon (Ib/gal) for n-
hexane, this is equivalent to baseline emissions of 556.45 tpy of n-hexane for Plant B.'
B-2
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-------
The uncontrolled emissions for Plant B were back-calculated from the baseline emissions using
information provided by the facility on equipment ratios for their production lines and on their
solvent recovery system. Of the uncontrolled emissions, 35 percent of the emissions are estimated
to be emitted from the Ross mixers line and 65 percent from the Sigma rrixer line.1 For each mixer
line, 80.5 percent of emissions are estimated to be emitted from the mixer itself and 19.5 percent
of the emissions are estimated to be emitted from the rest of the line (10.5 percent from extruder,
7.2 percent from granulator, 1.6 percent from dryers, and 0.2 percent from hot presses).1
Based on information frpm the facility, the Sigma mixer is equipped with a solvent recovery
\
system, the rest of the Sigma mixer line (extruder, granulator, dryers, and hot presses) is
uncontrolled, and the Ross mixers line is also uncontrolled.1 The solvent is drawn out of the
mixed material from the Sigma mixer by vacuum.2 The facility estimates that the residual solvent
content is 10 percent, which means that 90 percent of the solvent is captured from the mixture.'
The solvent vapors are collected by a non-contact Freon-cooled condenser, which cools the
solvent vapor to 60 °F.' According to the facility, the condenser is 80 percent efficient in
recovering the captured solvent.2 The total solvent recovery is estimated at 70 percent recovery
on average. These data were based on informal mass balance measurements performed by the
facility personnel for facility purposes. Using this facility information, the total uncontrolled
emissions were estimated using the following equation:
Baseline emissions (556.45 tpy) = (0.35 * x) + [(0.65 * 0.805 * 0.30 * x) +
(0.65 * 0.195 * x)], where x is total uncontrolled emissions. Solving for x, total
uncontrolled emissions = 878.06 tpy.
The uncontrolled emissions were broken out for the Sigma mixer line using the following
equations:
Uncontrolled emissions (Sigma mixer) = (0.65 * 0.805 * 878.06 tpy) = 459.45 tpy.
Uncontrolled emissions (extruder, granulator, dryers, and hot presses) =
(0.65 * 0.195 * 878.06 tpy) = 111.29 tpy.
The uncontrolled emissions were broken out for the Ross mixers line using the following
equations:
Uncontrolled emissions (Ross mixers) = (0.35 * 0.805 * 878.06 tpy) = 247.39 tpy.
Uncontrolled emissions (extruder, granulator, dryers, and hot presses) =
(0.35 * 0.195 * 878.06 tpy) = 59.93 tpy.
B-5
-------
Based on 70 percent solvent recovery, the baseline (controlled) emissions for the Sigma mixer
were estimated to be 0.3 * 459.45 tpy = 137.83 tpy. The baseline emissions for the Ross mixers
line and the rest of the Sigma mixer line (extruder, granulator, dryers, and hot presses) are the
same as the uncontrolled emissions because there is no solvent recovery for these equipment.
4r,
B.2.2 MACT Floor and Beyond-the-Floor Emissions
To comply with the MACT floor option (70 percent solvent recovery for solvent mixers), Plant B
is expected to equip its uncontrolled Ros§ mixers with a solvent recovery system (condenser)
capable of achieving 70 percent solvent recovery (including capture and collection). Therefore,
the emissions associated with the MACT floor option for Plant B were estimated based on a
70 percent reduction in uncontrolled emissions for the Ross mixers (0.3 * 247.39 tpy = 74.22 tpy).
The emissions for the rest of the Ross mixers line and the entire Sigma mixer line would remain at
baseline levels.
To comply with the beyond-the-floor option (85 percent solvent recovery for solvent mixers),
Plant B is expected to equip its Sigma mixer and Ross mixers with solvent recovery systems
(condensers) capable of achieving 85 percent solvent recovery (including capture and collection).
Therefore, the emissions associated with the beyond-the-floor option for Plant B were estimated
based on an 85 percent reduction in uncontrolled emissions for the Sigma mixer and Ross mixers
(0.15 * 459.45 tpy + 0.15 * 247.39 tpy = 106.03 tpy). The emissions for the rest of the Sigma
mixer line and Ross mixers line would remain at baseline levels.
B.3 Plant C
B.3.1 Baseline and Uncontrolled Emissions
Uncontrolled emissions from Plant C were determined based on the annual consumption of
trichloroethylene solvent, assuming that the quantity of solvent consumed is equal to the quantity of
solvent emitted. According to the ICR response for Plant C, the annual consumption of
trichloroelhylene solvent for 1997 was expected to be 9,660 gal, and the HAP content of the
solvent is 100 percent; this is equivalent to an annual consumption of 58.39 tpy for
B-6
-------
trichloroethylene, based on a reported density of 12.09 lb/gal.3 Therefore, the total uncontrolled
emissions for Plant C were estimated to be 58.39 tpy.
Using the equipment ratios from Plant B as a model (80.5 percent from solvent mixer, 10.5 percent
from extruder, 7.2 percent from granulator, 1.6 percent from dryers, and 0.2 percent from hot
presses), 80.5 percent of the uncontrolled emissions at Plant C were assumed to be from the
*
solvent mixer. Emissions from the hot press were assumed to be equivalent to the total emissions
from the extruder and dryer (10.5 percent + 1.6 percent = 12.1 percent) because of the press'
relative position in the process and because it is heated. Emissions from the oven were assumed
to be equivalent to the remainder of the emissions (7.4 percent). Therefore, the uncontrolled
emissions for the solvent mixer were estimated to be 0.805 * 58.39 tpy = 47.00 tpy, while the
uncontrolled emissions for the rest of the solvent mixer line (hot press and oven) were estimated to
be 0.195* 58.39 tpy =11.39 tpy.
Baseline emissions for the solvent mixer were estimated based on the effectiveness of the vacuum
system used to capture and collect the trichloroethylene solvent and the control efficiency of the
carbon adsorber used to recover the trichloroethylene solvent. Based on information from Plant C,
the control efficiency of the carbon adsorber is 94 percent.4 No data are available on the
effectiveness of the vacuum system at removing the trichloroethylene solvent from the mixed
material. However, if the residual solvent content is similar to those at Plant B and Plant A (i.e.,
between 5 and 10 percent), the overall solvent recovery for the solvent mixer would be between
85 and 90 percent. To be conservative, a solvent recovery of 85 percent was assumed. Therefore,
baseline emissions for the solvent mixer were estimated to be 0.15 * 47.00 tpy = 7.05 tpy.
Because the rest of the solvent mixer line (hot press and oven) is uncontrolled, the emissions from
the?" pieces of equipment would remain unchanged (11.39 tpy).
B.3.2 MACT Floor and Beyond-the-Floor Emissions
The MACT floor and beyond-the-floor emissions for Plant C would be identical to baseline
emissions because the solvent mixer at this facility is assumed to already achieve 85 percent
B-7
-------
solvent recovery. Therefore, this solvent mixer is not impacted at the MACT floor and beyond-
the-floor.
>
B.4 Plant D
B.4.1 Baseline and Uncontrolled Emissions
Uncontrolled emissions from Plant D were determined based on the annual consumption of toluene
solvent, assuming that the quantity of solvent consumed is equal to the quantity of solvent emitted.
According to the ICR response for Plant D, the annual consumption of toluene solvent for 1997
was expected to be 13,069 gallons, and the HAP content of the solvent is 100 percent; this is
*
equivalent to an annual consumption of 47.70 tpy for toluene, based on a reported density of 7.3
Ib/gal for toluene.7 Therefore, the uncontrolled emissions for Plant D were estimated to be
47.70 tpy.
Using the equipment ratios from Plant B as a model (80.5 percent from solvent mixer, 10.5 percent
from extruder, 7.2 percent from granulator, 1.6 percent from dryers, and 0.2 percent from hot
presses), 80.5 percent of the emissions at Plant D were assumed to be from the solvent mixer.
Because Plant D has no granulator, ratios were used to apportion the granulator emissions to the
extruder (16.1 percent), dryer (2.9 percent), and hot press (0.5 percent). Therefore, the
uncontrolled emissions for the solvent mixer were estimated to be 0.805 * 47.70 tpy = 38.40 tpy,
while the uncontrolled emissions for the rest of the solvent mixer line (extruder, dryer, and hot
press) were estimated to be 0.195 * 47.70 tpy = 9.30 tpy.
B.4.2 MACT Floor and Beyond-the-Floor Emissions
To comply with the MACT floor option (70 percent solvent recovery for solvent mixers), Plant D
is expected to equip its uncontrolled solvent mixer with a solvent recovery system (condenser)
capable of achieving 70 percent solvent recovery (including capture and collection). Therefore,
the emissions associated with the MACT floor option for Plant D were estimated based on a
70 percent reduction in uncontrolled emissions for the solvent mixer (0.3 * 38.40 tpy = 11.52 tpy).
The emissions for the rest of the solvent mixer line would remain at baseline levels (9.30 tpy).
B-8
-------
To comply with the beyond-the-floor option (85 percent solvent recovery for solvent mixers),
Plant D is expected to equip its uncontrolled solvent mixer with a solvent recovery system
(condenser) capable of achieving 85 percent solvent recovery (including capture and collection).
Therefore, the emissions associated with the beyond-the-floor option for Plant D were estimated
based on an 85 percent reduction in uncontrolled emissions for the solvent mixer (0.15 * 38.40 tpy
= 5.76 tpy). The emissions for the rest of the solvent mixer line would remain at baseline levels
(9.30 tpy).
B.5 References
t
1. Completed information collection request for Plant A.
2. Memorandum from Bullock, D., Midwest Research Institute, to Cavender, K., EPA/ESD.
Site Visit Report Plant-A.
3. Completed information collection request for Plant B.
4. Memorandum from Schmitt, D., Bullock, D., and Abraczinskas, M., Midwest Research
Institute, to Cavender, K., EPA/ESD. Site Visit Report-Plant B.
5. Completed information collection request for Plant C.
6. Memorandum from Abraczinskas, M., Bullock, D., Holloway, T., and Turner, M., Midwest
Research Institute, to Cavender, K., EPA/ESD. August 3, 2001. Summary of Emission
Test Data.
7. Completed information collection request for Plant D.
B-9
-------
TECHNICAL REPORT DATA
1. REPORT NO.
EPA-453/R-01-008 -
2.
4. TITLE AND SUBTITLE
National Emission Standards for Hazardous Air Pollutants
(NESHAP) for the Friction Materials Manufacturing Industry-
Background Information Document
7. AUTHOR(S)
9. PERFORfrfiNG ORGANIZATION NAME AND ADDRESS
Midwest Research Institute
5520 Dillard Road, Suite 100
Gary, NC 27511
12 SPONSORING AGENCY NAME AND ADDRESS ,
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
August 2001
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D6-0012
13 TYPE OF REPORT AND PERIOD COVERED
Final (1997-2001)
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
National emission standards for hazardous air pollutants (NESHAP) for friction materials manufacturing
facilities are being proposed under the authority of Section 1 12(d) of the Clean Air Act as amended in
1990. These standards would reduce air toxics from all major source friction materials manufacturing
facilities (defined as those sources that emit or have the potential to emit 10 tpy or greater of individual
HAPs, or 25 tpy or greater of any combination of HAPs). This document contains background
information and environmental and cost impact assessments of the emission control options considered in
developing the proposed standards.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
n-Hexane
Solvent mixer
Solvent recovery
Toluene
Trichloroethylene
18. DISTRIBUTION STATEMENT
Release Unlimited
b. IDENTIFIERS/OPEN ENDED TERMS c COSATI Field/Group
Air pollution control
Friction materials manufacturing
Hazardous air pollutants
MACT
NESHAP
19. SECURITY CLASS (Report) 21. NO. OF PAGES
Unclassified
20. SECURITY CLASS (Page) 22. PRICE
Unclassified
EPA Form 2220-1 (Rev. 4-77)
PREVIOUS EDITION IS OBSOLETF
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