&EPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-82-003
February 1982
Air
Vinyl Chloride-
A Review
Of National Emission
Standards
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EPA-450/3-82-003
Vinyl Chloride - A Review
Of National Emission Standards
Prepared by TRW, Inc.
P.O. Box 13000
Research Triangle Park, North Carolina 27709
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
February 1982
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DISCLAIMER
This draft report was submitted to the Emission Standards and
Engineering Division of the Office of Air Quality Planning and Standards
of the Environmental Protection Agency by TRW Environmental Engineering
Division, Research Triangle Park, North Carolina in fulfillment of
Contract No. 68-02-3063. The contents of this report are reproduced
herein as received from TRW. The opinions, findings, and conclusions
expressed are those of the authors and not necessarily of the Environ-
mental Protection Agency. Mention of company or product names is not to
be considered as an endorsement by the Environmental Protection Agency.
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ACKNOWLEDGEMENTS
This study was performed under NSS Contract No. 68-02-3063 with the
U.S. EPA Office of Air Quality Planning and Standards. The success of
the study was dependent on information submitted voluntarily by the
industries regulated under the VC NESHAP- Many representatives of those
industries were very cooperative, and their contributions are cited
throughout this report. The authors would like to acknowledge their
assistance.
Several regional EPA personnel also contributed extensive
information and provided data necessary to evaluate the current status
of emission control in the industry.
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ABBREVIATIONS AND ACRONYMS USED IN THIS REPORT
AAQS Ambient Air Quality Standard
APRS Automatic Pressure Reduction System
BACT Best Available Control Technology
BAT Best Available Technology
BID Background Information Document
CAA Clean Air Act
CARB California Air Resources Board
CFR Code of Federal Regulations
CMA Chemical Manufacturers Association
CTA Chain Transfer Agent
CTG Control Techniques Guidelines
DOT Department of Transportation
DSSE Division of Stationary Source Enforcement
EDC Ethylene Dichloride
EPA Environmental Protection Agency
FDA Food and Drug Administration
FID Flame ionization detector
FR Federal Register
HC Hydrocarbon
KO Knock-out (vessel)
LEL Lower explosive limit
NAAQS National Ambient Air Quality Standards
NESHAP National Emission Standard for Hazardous Air Pollutants
NIOSH National Institute for Occupational Safety and Health
iv
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NPDES National Pollution Discharge Elimination System
NSPS New Source Performance Standards
OAQPS Office of Air Quality Planning and Standards
OSHA Occupational Safety and Health Administration
OVA Organic vapor analyzer
PMN Premanufacturing Notice
ppm Parts per million
PSD Prevention of significant deterioration
PVC Polyvinyl chloride
RACT Reasonably Available Control Technology
RCRA Resource Conservation and Recovery Act
ROL Reactor opening loss
RVC Residual vinyl chloride
RVD Relief valve discharge
SCAQMD South Coast Air Quality Monitoring District
SIP State Implementation Plans
SOCMI Synthetic Organic Chemical Manufacturing Industry
SPI Society for the Plastics Industry
SSEIS Standard Support and Environmental Impact Statement
TSCA Toxic Substances Control Act
VC Vinyl chloride
VOC Volatile organic compounds
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TABLE OF CONTENTS
Section Page
1.0 EXECUTIVE SUMMARY 1-1
1.1 Introduction 1-1
1.2 Process Developments 1-1
1.3 Control Technology Summary 1-2
1.4 Primary Controls 1-2
1.5 Relief Valve Discharges 1-4
1.6 Resin Stripping 1-4
1.7 Fugitive Emissions 1-5
1.8 Reactor Opening Loss 1-6
1.9 Enforcement and Compliance Experience 1-6
1.10 Unregulated Sources 1-7
1.11 Impact of Other Regulations 1-7
2.0 INTRODUCTION 2-1
2.1 Background Information 2-1
2.2 Scope of Review Study 2-2
2.2.1 Areas of Concern 2-2
2.2.2 Review Study Methods 2-9
2.3 The Vinyl Chloride Emitting Industry 2-9
2.3.1 Current Number and Geographical Distribution. . 2-9
2.3.2 Influence of the Standard on Industry 2-11
2.3.3 Industrial Trends 2-12
2.5 References for Chapter 2 2-14
3.0 PROCESS DESCRIPTION 3-1
3.1 Introduction 3-1
3.2 Production of Ethylene Dichloride 3-4
3.2.1 Direct Chiorination of Ethylene 3-5
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Section Page
3.2.2 Oxychlorination of Ethylene 3-5
3.2.3 Purification of Ethylene Dichloride 3-7
3.3 Production of Vinyl Chloride 3-9
3.3.1 Formation of Vinyl Chloride by
Dehydrcchlorination of Ethylene Dichloride. . . 3-9
3.3.2 Purification of Vinyl Chloride 3-10
3.3.3 Emissions for Typical EDC/VC Plants 3-10
3.4 Production of Polyvinyl Chloride 3-11
3.4.1 Free Radical Polymerization 3-16
3.4.2 Unloading of VC at PVC Plant Sites 3-17
3.4.3 Mixing, Weighing and Holding Vessels 3-18
3.4.4 Suspension Polymerization 3-18
3.4.5 Dispersion Polymerization 3-21
3.4.6 Bulk Polymerization 3-23
3.4.7 Solution Polymerization 3-28
3.4.8 Polymerization Reactors 3-32
3.4.9 Emissions for a Typical PVC Plant 3-37
3.5 References for Chapter 3 3-39
4.0 CONTROL TECHNIQUES USED TO COMPLY WITH THE EXISTING
EMISSION STANDARD 4-1
4.1 Discharge of Exhaust Gases to the Atmosphere 4-1
4.1.1 Introduction 4-1
4.1.2 Incineration 4-7
4.1.3 Steam Boilers 4-11
4.1.4 Flares 4-11
4.1.5 Carbon Adsorption 4-13
4.1.6 Solvent Absorption 4-14
4.1.7 Refrigeration 4-15
4.1.8 Other Controls 4-16
4.2 Relief Valve Discharges 4-17
4.2.1 Introduction 4-17
4.2.2 Emissions from Safety Relief Valves 4-18
4.2.3 Relief Valve Discharges from Reactors 4-23
4.2.3.1 Process Variations 4-23
4.2.3.2 Causes of Reactor Discharges 4-25
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Section Page
4.2.3.3 Prevention of Reactor Discharges . . . 4-28
4.2.3.3.1 Current generic preventive
methods 4-28
4.2.3.3.2 Preventive systems
currently in use 4-40
4.2.4 Non-Reactor Relief Valve Discharges 4-48
4.3 Resin Stripping 4-52
4.3.1 Introduction 4-52
4.3.2 Suspension Resin Stripping 4-54
4.3.3 Emulsion Resin Stripping 4-57
4.3.4 Bulk (Mass) Resin Stripping 4-58
4.3.5 Solution Resin Stripping 4-58
4.3.6 Other Stripping Technologies 4-59
4.4 Fugitive Emissions 4-59
4.4.1 Introduction 4-59
4.4.2 Equipment Specifications 4-62
4.4.3 Operational Procedures 4-66
4.4.4 Leak Detection and Elimination Programs ..... 4-67
4.4.5 Inprocess Wastewater 4-80
4.5 Reactor Opening Loss 4-81
4.5.1 Introduction 4-81
4.5.2 Solvent Cleaning 4-82
4.5.3 Steam Piston 4-84
4.5.4 Water Piston 4-85
4.5.5 Reactor Purge Air Blower 4-85
4.5.6 Steam Purge 4-85
4.5.7 Redox Catalysis 4-86
4.5.8 Water Jet Cleaning 4-86
4.5.9 Clean Reactor (Closed Cleaning) Technology. . . 4-86
4.5.10 Nitrogen Purge 4-87
4.5.11 Slurry Backfill 4-87
4.5.12 Calculated Emissions 4-88
4.6 References for Chapter 4 4-90
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Section Page
5.0 ENFORCEMENT AND COMPLIANCE EXPERIENCE 5-1
5.1 Introduction 5-1
5.2 Intent of the Standard 5-1
5.3 Standards for EDC and VC Plants 5-2
5.4 Exhaust Gases to the Atmosphere 5-2
5.5 Inprocess Wastewater 5-3
5.6 Reactor Opening Loss 5-3
5.7 Relief Valve Discharge 5-4
5.8 Resin Stripping 5-5
5.9 Sources After the Stripper 5-7
5.10 Fugitive Emissions 5-7
5.11 Leak Detection and Elimination Programs 5-8
5.12 Emissions Testing and Analysis 5-8
5.13 Reporting 5-10
5.14 Recordkeeping 5-10
5.15 NESHAP Applicability Determinations 5-10
5.16 References for Chapter 5 5-13
6.0 UNREGULATED SOURCES OF VINYL CHLORIDE 6-1
6.1 Introduction 6-1
6.2 Sources Identified During Original Study 6-1
6.2.1 Fabricating Operations 6-1
6.2.2 Miscellaneous Sources 6-4
6.3 New Sources Identified During Review Study 6-5
6.3.1 Mobile Sources of Emissions 6-5
6.3.2 Nonplant Transfer Facilities 6-6
6.3.3 Solid Waste Drying Facilities 6-7
6.3.4 Disposal Facilities (Landfill) 6-7
6.4 References for Chapter 6 6-8
7.0 IMPACT OF OTHER REGULATIONS 7-1
7.1 Introduction 7-1
7.2 Clean Air Act (CAA) 7-2
7.2.1 Carcinogen Rule 7-3
7.2.2 Prevention of Significant Deterioration (PSD) . 7-3
7.2.3 NESHAP Delegation to States . 7-7
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Section Page
7.3 Resource Conservation and Rcovery Act (RCRA) 7-10
7.4 Toxic Substances Control Act (TSCA) 7-11
7.5 Clean Water Act 7-12
7.6 Safe Drinking Water Act 7-12
7.7 Hazardous Materials Transportation Act 7-13
7.8 Occupational Safety and Health Act 7-13
7.9 Superfund Legislation 7-13
7.10 Food and Drug Administration Regulations 7-14
7.11 Other State and Local Regulations 7-14
7.12 References for Chapter 7 7-15
APPENDIX A - Vinyl Chloride NESHAP
APPENDIX B - Regional EPA and Industrial Contacts
APPENDIX C - Current Industrial Sources
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LIST OF TABLES
Table Page
2-1 Emission Standards in the VC NESHAP 2-3
2-2 Summary of Reporting and Recordkeeping Requirements
in the VC NESHAP 2-6
2-3 Geographic Distribution of Operating VC-Emitting Plants. . 2-10
3-1 Point Source Emissions - "Balanced Process" EDC/VC
Plants 3-3
3-2 Point Source Emissions Typical of Suspension and
Dispersion PVC Plants 3-13
3-3 Point Source Emissions Typical of Bulk PVC Plants 3-25
3-4 Point Source Emissions Typical of Solution Process PVC
Plants 3-30
4-1 Point Source Emissions and Technologies for Control in
Typical Suspension, Dispersion, and Bulk PVC Plants. . . . 4-2
4-2 Point Source Emissions and Technologies for Control in
"Balanced Process" EDC/VC Plants 4-4
4-3 Emissions Reduction for 316 M kg/yr EDC/VC Facility in
Compliance with Current Regulation 4-5
4-4 Emissions Reduction for 68 M kg/yr PVC Facility in
Compliance with Current Regulation 4-6
4-5 Total Relief Valve Discharges for 32 Regulated Sources
From 1977 to 1980 4-20
4-6 Relief Valve Discharges from PVC Plants 4-21
4-7 Relief Valve Discharges from EDC/VC Plants 4-22
4-8 Estimated Costs for an Auxiliary Venting System 4-32
4-9 Typical Gasholder Specifications for 38,000 Liter
(10,000 Gallon) Reactor 4-35
4-10 Estimated Cost for Installation of a Gasholder 4-36
4-11 Percent Distribution of Stripping Levels Being Achieved
by Industry 4-55
4-12 Approved or Conditionally Approved Equipment Equivalency
Determinations 4-64
4-13 Leak Detection and Elimination Programs 4-70
4-14 Variability in Leak Definitions 4-72
4-15 Calibration Results for Area-Wide Monitor 4-75
4-16 Reactor Opening Loss Reported by Representative Companies. 4-83
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LIST OF FIGURES
Figure Page
3-1 EDC/VC "Balanced Process" Flow Diagram 3-2
3-2 Suspension and Dispersion Process Flow Diagram 3-12
3-3 PVC Resins, PVC Compounds, and PVC Fabrication Processes .... 3-15
3-4 Bulk Process Flow Diagram 3-24
3-5 Solution Process Flow Diagram 3-29
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1.0 EXECUTIVE SUMMARY
1.1 INTRODUCTION
This Phase I review study assesses the current National Emission
Standard for vinyl chloride (VC) by investigating emission control
techniques. This review evaluates technological developments in the
industry and provides a preliminary basis for possible standard revision.
Recommendations to revise the standard would be supported by a more
detailed Phase II study that would develop a Background Information
Document (BID). This review study was conducted under a contract awarded
to TRW's Environmental Engineering Division by the U.S. Environmental
Protection Agency (EPA).
The review study focused on four areas which are summarized below:
• Technologies currently used for compliance.
• Existing sources identified during the original support study
but not subject to the current regulation.
t Emission sources not identified during the original support
study.
• Enforcement and compliance experience.
Additional details can be found in corresponding sections of the
text (indicated in parentheses). A description of the processes involved
in VC production and polymerization is presented in Chapter 3.
1.2 PROCESS DEVELOPMENTS
The sources subject to the VC regulation are ethylene dichloride
(EDC) produced by oxychlorination, VC, and polyvinyl chloride (PVC)
facilities. Recent modifications of processes in these facilities
include:
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t EDC/VC - The "balanced process" utilizing direct chlorination
and oxychlorination is the most common process used for pro-
duction of EDC and VC. Many newer plants and some existing
plants have incorporated oxygen oxychlorination plants as part
of the EDC process. The change from air to pure oxygen as a
feedstock can make combustion more feasible and therefore
could result in reduced emissions from the oxychlorination
vent.
(Section 3.2.1 and 3.2.2)
• PVC - Newer plants are incorporating larger reactor systems
resulting in increased capacity, fewer reactor openings and
reduced emissions. These large reactor systems have also
accounted for a decrease in the production of specialty PVC
resins.
(Section 4.2.3.1)
1.3 CONTROL TECHNOLOGY SUMMARY
Most of the discussion regarding VC control technology is focused
on PVC plants because these facilities contribute proportionately more
emissions. For this reason, most of the requirements in the VC regu-
lations pertain to PVC plants. The characteristics inherent in the
batch processes of these plants account for the relative difficulty in
emission control implementation.
1.4 PRIMARY CONTROLS
Control devices, applied to reduce VC emissions when exhaust gases
are discharged to the atmosphere, include:
• Incineration - This method represents the most prevalent means
of primary control and is the only one used by both EDC/VC and
PVC plants. (Solvent absorption and carbon adsorption are
also used as primary controls in PVC plants, but in EDC/VC
plants they are used on a smaller scale as part of the process
or as a means to reduce fugitive emissions.)
Although thermal incineration is most commonly used, two
plants are using catalytic oxidation systems. In most cases,
1-2
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thermal incineration is reducing emissions below the required
10 ppm. Most units have scrubbers to prevent HC1 emissions.
(Section 4.1.2)
Solvent Absorption - This method is effective in reducing
emissions below 10 ppm. It is used as primary control only in
PVC plants. VC is recovered by this method rather than
destroyed (as with incineration).
(Section 4.1.6)
Carbon Adsorption - As a primary control, this method is not
as effective (in most cases) as incineration or solvent
absorption in achieving the 10 ppm level. Usually, carbon
adsorbers must be supplemented by other primary controls
(e.g., incineration). Some plants that initially selected
carbon adsorption as a primary control for exhaust gases have
replaced the carbon beds totally with another control device.
Carbon adsorption is effective on a smaller scale for reducing
fugitive emissions or for recovering VC from some exhaust
gases.
(Section 4.1.5)
Other Controls - These include steam boilers, flares,
refrigeration systems and containment devices. Boilers are
not usually used for primary control due to corrosion problems.
Efficiency of VC reduction in flares has not been determined.
Secondary pollutants (e.g., noise, smoke) have also been noted
as a disadvantage of flares. Refrigeration systems are generally
used as part of recovery systems or as back-up control in case
of primary control breakdown. Containment devices are used to
reduce emissions to the atomosphere and include gasholders and
pressurized holding vessels. These devices collect vapors
from various equipment vents and feed the VC recovery system
and/or primary control device. They are also used in some
cases to collect and hold emissions when the primary control
is down for maintenance.
(Sections 4.1.3, 4.1.4, 4.1.7, 4.1.8, and 4.2.3.3.1)
1-3
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1.5 RELIEF VALVE DISCHARGES
Relief valve discharges cause short term excursions of VC emissions
and, according to EPA regional enforcement personnel, represent the
single most difficult enforcement problem.
• Contention is caused by the wording in the regulation that
allows only "emergency" relief valve discharges.
(Sections 4.2.1 and 5.7)
• Regional personnel indicate relief valve discharges continue
to occur, but the frequency and magnitude vary throughout the
industry. PVC reactors are responsible for the greatest
frequency and largest quantities of emissions, but nonreactor-
related discharges contribute approximately 34 percent of the
relief valve events and 20 percent of the total quantity
discharged.
(Section 4.2.2)
• Reactor releases are affected by the type of polymerization
process and whether the newer reactors are employed. The
newer reactors are larger and incorporate more instrumentation.
They appear to provide better control over upset conditions
that could result in a relief valve discharge.
(Section 4.2.3)
• Procedures for prevention of relief valve discharges vary from
plant to plant. Many of these procedures have reduced the
frequency of discharges.
1.6 RESIN STRIPPING
Because stripping techniques are different for each type and grade
of resin, a wide range of residual VC (RVC) content in the stripped
resin has been noted.
t Suspension Resins - These resins represent the highest
percentage of total PVC production. The most widely used
stripping method is continuous steam stripping. Many
processors are attaining levels much lower than the required
400 ppm RVC - some less than 20 ppm.
(Section 4.3.2)
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• Dispersion Resins - Dispersion or emulsion resins are usually
vacuum stripped batchwise in the reactor or in separate batch
stripping vessels. Continuous stripping technologies for
dispersion resins are not as advanced as for suspension resins.
Required emission levels for dispersion resins (2,000 ppm) are
being met and, in some cases, processors are regularly achieving
levels below 1,000 ppm. Latex resins, produced by the dispersion
process and usually sold undried, are required to meet a 400
ppm level. These resins are sensitive to heat and shear
stress, creating difficulties in stripping efficiently.
(Section 4.3.2)
• Bulk Resins - The characteristics of these resins (e.g.,
uniform porosity and size) enhance stripping efficiency.
Steam stripping (under vacuum) in the reactor is used for
these resins.
(Section 4.3.4)
• Solution Resins - Only one plant produces solution resins.
This process is unique among stripping procedures because no
particulate resin form exists. Stripping is a distillation
process with a high efficiency averaging levels of 10 ppm RVC.
(Section 4.3.5)
1.7 FUGITIVE EMISSIONS
Fugitive emissions represent one of the larger contributions to VC
emissions at EDC/VC and PVC plants.
• PVC plants appear to contribute more fugitives because of the
batch process characteristics and the prevalence of plants
with many old small reactors. One study done by a PVC pro-
cessor indicated that, after installation of required equipment
to control fugitives and implementation of leak detection and
elimination programs, a large reduction was achieved in fugitive
emissions. Emissions from their old small reactor system are
now 75 percent lower than the industry average fugitive emissions
as estimated in the original standard support study. Those
1-5
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from their newer large reactor systems are now 95 percent
lower.
(Section 4.4.1)
• EPA Regional personnel indicate that almost all plants have
installed the required equipment specified in the current
regulation and are following the required operational proce-
dures. Some plants have received approval for equivalent
equipment.
(Sections 4.4.2 and 4.4.3)
• The leak detection and elimination programs represent the
greatest variability among plants surveyed. Leak detection
programs and routine surveys with portable monitors vary
widely among the plants. In most cases, other requirements
have been addressed adequately (e.g., area monitoring and
plans to eliminate leaks) and fugitives have been lowered.
(Section 4.4.4)
1.8 REACTOR OPENING LOSS (ROL)
Control of this emission source is achieved through various
technologies and process modifications. Several methods have been
developed that are effective in reducing ROL emissions to levels below
those required by the regulation. "Clean reactor" technology has also
contributed to a reduction in emissions from this source. Selection of
the type of control (reactor purging) is based primarily on operating
preferences and economics.
There is a problem in emission level determination for those
processors whose resins are stripped in the reactor. Because actual
measurements cannot be made to ascertain RVC levels, determination is
based on calculations. These may not always be indicative of actual
emissions.
(Section 4.5)
1.9 ENFORCEMENT AND COMPLIANCE EXPERIENCE
Industrial representatives and regional EPA personnel cited several
areas of concern regarding enforcement and compliance experiences under
the existing VC NESHAP. While many of these points were specific to
either industry or the EPA, several areas reflected viewpoints common to
1-6
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both. Chapter 5 lists and discusses these concerns. Enforcement of
relief valve discharges is the most common concern.
(Chapter 5)
1.10 UNREGULATED SOURCES
Many of the sources not currently regulated under the VC standard
were identified during the original study. These include PVC compounders
and fabricators as well as processors using VC as a chemical inter-
mediate or producing it as a byproduct. The implementation of the OSHA
workplace standard for VC has resulted in fabricators' receiving resins
with RVC levels of 10 ppm or lower. This has greatly reduced emission
levels from fabricating facilities. Facilities manufacturing certain
pesticides and trichloroethanes use VC as an intermediate, and emission
information on these processes was not obtained during this study phase.
Unregulated sources producing VC as a byproduct were contacted and
they reported that the small amount of VC involved was either incinerated
or recycled through recovery systems for use in polymerization processes
in another facility.
Other sources include mobile sources, nonplant transfer facilities,
solid waste drying facilities and disposal sites (landfills). Each of
these represents a potential VC emission source and each has been
identified as an area of concern by regional EPA personnel.
(Chapter 6)
1.11 IMPACT OF OTHER REGULATIONS
There has been substantial regulatory activity since promulgation
of the current VC NESHAP. The new regulations that will have an effect
in reducing VC emissions to the atmosphere are Prevention of Significant
Deterioration (PSD) of Air Quality, plans for nonattainment review, and
delegation of NESHAP authority, all under the Clean Air Act. These
regulations call for the reduction of VC emissions below those previously
required by the VC NESHAP. Other new regulations that will also have an
effect on levels of VC emissions include the Resource Conservation and
Recovery Act (RCRA) for the control of hazardous wastes, the Toxic
Substances Control Act (TSCA) which regulates any new chemicals involved
in polymer development, and the Clean Water Act requiring the development
of effluent guidelines for VC as well as a possible VC drinking water
standard.
(Chapter 7)
1-7
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2.0 INTRODUCTION
2.1 BACKGROUND INFORMATION
The vinyl chloride (VC) standard was promulgated in 1976 under
Section 112 of the Clean Air Act (CAA), National Emission Standards for
Hazardous Air Pollutants (NESHAP), and is applicable to new and existing
sources of VC - those plants producing VC and/or polymerizing VC into
polyvinyl chloride (PVC). The proposed NESHAP "Policy and Procedures
for Identifying, Assessing, and Regulating Airborne Substances Posing a
Risk of Cancer" would require that emission standards promulgated under
Section 112 be reviewed at intervals of no more than 5 years. These
reviews would be used to determine the need for revision of the emission
standard.
VC was first implicated as a highly specific cause of angiosarcoma,
a rare cancer of the liver, by evidence from occupational exposures.
Following intensive study, the Occupational Safety and Health Administra-
tion (OSHA) promulgated a standard in 1975 to reduce occupational exposure
to VC, and the EPA promulgated a standard in 1976 to reduce atmospheric
VC emissions. Waivers of compliance were granted, in some cases for up
to 2 years, allowing industry to incorporate necessary controls.
The existing VC NESHAP (henceforth referred to as the regulation)
is one of the most complex air emissions standards promulgated by the
EPA. The regulation is applicable to three different types of facilities -
plants producing ethylene dichloride (EDC) by the reaction of oxygen and
hydrogen chloride with ethylene, plants producing VC by any process, and
plants producing one or more polymers containing any fraction of VC.
Research and development facilities containing a polymerization reactor
capacity greater than 0.2 cubic meters (50 gallons) but no more than
4 cubic meters (1100 gallons) are exempt from all parts of the regulation
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except the 10 ppm emission limit. Reactors less than 0.2 cubic meters
(50 gallons) are not regulated. Those reactors greater than 4 cubic
meters (1100 gallons) are subject to all requirements of the regulation.
Each of these facilities are subject to different standards at
numerous points in the manufacturing process - numerical emission limits,
equipment specifications, and work practice requirements (i.e., working
procedures that must be followed by plant personnel). Table 2-1 lists
each section of the regulation requiring a specific standard and the
type of plant subject to that standard. The current regulation is
reproduced in Appendix A.
Compliance with the current regulation is determined through testing
and monitoring results and extensive reporting and recordkeeping require-
ments (all of which are conducted by the plant). The plants are required
to report to the responsible Regional EPA office and EPA enforcement
personnel conduct standard compliance tests and review plant procedures
and records periodically. Requirements for reporting and recordkeeping
are summarized in Table 2-2.
2.2 SCOPE OF THE REVIEW STUDY
Periodic review of regulations is an important part of the standards
development program. The purpose of these reviews is to investigate the
control techniques applied to industrial processes for reducing VC air
emissions.
2.2.1 Areas of Concern
The review study conducted to assess the current VC regulation
concentrated on four areas of concern:
• Technologies being used for compliance,
• Existing sources identified during the original support study
but not subject to the current regulation,
• New emission sources not identified during the original support
study, and
• Enforcement and compliance experience.
Each of these areas served as focal points for research and appropriate
study methodology. The original study supporting the current regulation
(EPA, 1975) was thoroughly reviewed including all the information submitted
2-2
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Table 2-1. EMISSION STANDARDS IN THE VC NESHAP
Section
61.62(a)
61.62(b)
61.63(a)
61.64(a)(l)
61.64(a)(2)
61.64(a)(3)
61.64(b)
61.64(c)
61.64(d)
61.64(e)(l)
Applicability
Exhaust gases discharged to the atmosphere from any
equipment used in EDC purification.
Emissions of VC to the atmosphere from
oxychl or 1 nation reactors.
Discharge of exhaust gases to the atmosphere from any
equipment used in VC formation and/or purification.
PVC reactor exhaust gases discharged to the atmosphere.
Allowable reactor opening losses of vinyl chloride
based on the amount of product produced between
openings.
Discharge to the atmosphere from any manual vent valve
on a PVC reactor.
Exhaust gases discharged to the atmosphere from a
stripper.
Exhaust gases discharged to the atmosphere from
mixing, weighing, and holding containers which
precede reactors.
Exhaust gases discharged to the atmosphere from
monomer-recovery systems .
Emissions of vinyl chloride to the atmosphere from
the combination of all sources following the stripper.
Pertains to the requirements of residual VC (RVC)
levels attained with the stripping process.
Standard
<_ 10 ppm
Q.2 g/kg 1QQX EDC product
_< 10 ppm
<_ 10 ppm
0.02 g VC/kg PVC
none (except for an emergency)
i. 10 ppm
1 10 ppm
<_ 10 ppm
2000 ppm - dispersion resins
(excluding latex)
400 ppm - all other resins
(including latex)
Plants Involved
EDC
EDC
VC
PVC
PVC
PVC
PVC
PVC
PVC
PVC
ro
CO
(continued)
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Table 2-1. Continued
Section
Applicability
Standard
Plants Involved
61.64(e)(2)
l\3
I
61.65(a)
61.65(b)(l)
61.65(b)(2)
61.65(b)(3)
61.65(b)(4)
Emissions of vinyl chloride to the atmosphere from
the combination of all sources following the reactor
If the plant has no stripper; or from sources
following the stripper if the plant uses technology
in addition to stripping.
Discharge to the atmosphere from any relief valve
on any equipment in VC service (equipment contains or
contacts either a liquid at least 10% by weight VC or
gas 10% by volume VC).
Fugitive emissions to the atmosphere from loading
and unloading lines in VC service
(1) opening of the lines
(.11) VC removed from these lines to meet (1) and
ducted to a control system
Fugitive emissions to the atmosphere from slip gauges
(in VC service) used during loading and unloading
operations.
Fugitive emissions to the atmosphere from pump,
compressor, and agitator seal leakage.
Fugitive emissions to the atmosphere from leakage
of relief valves on equipment in VC service.
2 g/kg product from
the stripper (or reactor)
for dispersion PVC resins
(excluding latex)
0.4 g/kg product from the
stripper (or reactor) for
all other PVC resins
(including latex)
none (except for an emergency)
PVC
EDC, VC and PVC
EDC, VC, PVC
(i) 0.0038 nT VC 0 STP
(ii) <_ 10 ppm
<_ 10 ppm
'<_ 10 ppm
minimized by Installation of
a rupture disk or by connec-
tion of discharge to a process
line or recovery system
EDC, VC, PVC
EDC, VC, PVC
EDC, VC, PVC
(continued)
-------
Table 2-1. Concluded
Section
Applicability
Standard
Plants Involved
INJ
i
en
61.65(b)(5)
61.65(b)(6)
61.65(b)(7)
61.65(b)(8)
Fugitive emissions to the atmosphere from manual
venting of gases.
Fugitive emissions to the atmosphere from opening
of equipment.
(i) before opening
(ii) VC removed from equipment to meet (i) and
ducted to a control system
Fugitive emissions to the atmosphere from sampling.
• unused sample portions containing >_ 10%
by weight VC
• sample containers in VC service
VC emissions due to leaks from equipment in VC service.
^ 10 ppm
(.i) total amount discharged
per opening must be 23U
by volume VC or 0.95 m
(whichever is larger)
(ii) <_ 10 ppm
return to process
purge into closed process
system
minimize via formal
leak detection and
elimination (LD & E)
program, designed by
operator and approved
by the Administrator.
EDC, VC, PVC
EDC, VC, PVC
EDC, VC, PVC
EDC, VC, PVC
-------
Table 2-2. SUMMARY OF REPORTING AND RECORDKEEPING REQUIREMENTS IN VC NESHAP
Section
Applicability
Requirements
Category
61.69(a)
61.69(b)(l)
(2)
61.69(c)
ro
i
CT>
Owner or operator of any
source to which this
subpart applies
Existing source or new
source having start-up
date preceding effective
date of regulation.
New source having start-
up date after effective
date.
Owners or operators of
above sources
Initial Report: Notification that equipment and procedural
specifications required in Section 61.65 (fugitive emission
control) have been implemented.
Submittal of above notification within 90 days of effective
date of regulation (unless waiver granted).
Submittal of above notification within 90 days of Initial
start-up date.
Notification inclusions:
t List of equipment Installed for compliance
• Description of physical and functional characteristics
of equipment
• Description of methods used for measuring or calculating
emissions
• Statement verifying that equipment is installed and
procedures are being used
Initial Reporting
61.70(a)
61.70(b)(l)
(2)
Owner or operator of any
source to which this
subpart applies
Existing source or new
source having start-up
date preceding effective
date.
New source having start-
up date after effective
date.
Semi-annual reporting to Administrator (September 15 and
March 15 of each year) containing the information described
in subsequent sections.
Submittal of notification within 180 days of the effective
date (unless waiver granted).
Submittal of notification within 180 days of initial start-
up date.
Semi-Annual Reporting
(continued)
-------
Table 2-2. Continued
Section
Applicability
Requirements
Category
61.70(c)
(1)
Owner or operator of
above sources
Same
ro
(2)
Owner or operator of PVC
plants 1n which stripping
operations are used
(3)
Same
Use specified test methods (from Appendix B) unless
equivalency or alternative method approved.
Reporting of any emissions averaged over one hour which are
in excess of limits prescribed for emissions from:
EDC purification equipment
Oxychlorination reactors
Equipment used for VC formation/purification
PVC reactor exhaust gases
Control systems for reactor emissions for ROL
Fugitives from loading/unloading lines
Fugitives from slip gauges
Fugitives from manual venting of gauges
Fugitives from equipment opening emissions ducted through
a control system
• Fugitives from inprocess wastewater emissions ducted
through a control system
Reporting of a record of the VC content in the PVC resin
using method 107 as follows:
a If batch stripped, sample each batch of each grade of
resin immediately after stripping
• If continuously stripped, sample each grade of resin
or at 8 hour intervals (whichever is more frequent)
• Determine the Quantity of materials processed by the
stripper on a dry solids basis
• Report VC content found in each sample, averaged
separately for each type of resin, over each calendar
day and weighted according to the quantity of each grade
of resin produced that day
• Retain records for at least two years
Report record of Reactor Opening Loss (ROL) emissions
(continued)
Semi-Annual Reporting
-------
Table 2-2. Concluded
Section
Applicability
Requirements
Category
61.71(a)
(1)
(2)
(3)
(4)
Owner or operator of
any source to which
this subpart applies
Same
Same
Same
Same
Retention of the following information (for minimum of
two years):
• Record of leaks detected by the VC monitoring system
• Record of leaks detected during routine monitoring with
the portable hydrocarbon detector and action taken to
repair the leaks
• Record of emissions measured by the continuous VC
monitoring of sources listed in 61.70(c)(l)
• Daily operating record for each PVC reactor including
pressures and temperatures
Recordkeeping
61.64(a)(3)
INJ
I
CO
61.65(a)
PVC plants only
EDC, VC and PVC plants
Manual vent valve discharge.
Operator of source must notify Administrator within 10 days
of occurrence and submit a report containing the following:
Source of relief valve discharge
Nature and cause of discharge
Date and time of discharge
Approximate quantity of VC lost during discharge
Method used for determining VC loss
Action taken to stop discharge
Action to be taken to prevent future discharges
Relief valve discharge.
Operator of source must notify Administrator within 10 days
of occurrence and submit a report containing the following:
(Same as requirements for "Manual vent valve discharge"
abovel.
Exception Reporting
-------
to EPA under authority of Section 114 of the Clean Air Act (CAA).
Section 114 authority was also used to review Regional source files, but
no Section 114 information requests were sent to any subject sources.
All responses were given voluntarily and cleared of any confidential
material prior to inclusion in this report. The results presented here
will form the basis for preliminary recommendations for revision of the
current regulation and will identify additional research that is needed
to support these revisions.
2.2.2 Review Study Methods
The following methods were used to conduct the review study.
• A literature review was conducted using published and unpublished
information found in trade journals, EPA studies, EPA contractor-
conducted studies, other governmental agency studies, and
other pertinent references.
• EPA Regional personnel involved in enforcement and surveillance
of the VC emitting industries from Regions I, II, III, IV, V,
VI, and IX were consulted. Discussions were conducted during
regional office visits, by telephone, and by mail.
• Representative plants in each region were visited (three
EDC/VC plants and eight PVC plants). An effort was made to
include old and new plants of each type as well as plants
using the various process types.
• Meetings were held with industrial representatives to discuss
control technologies currently used by their plants. Discussions
were also held with representatives of two of the industry's
trade organizations - the Society for the Plastics Industry
(SPI) and the Chemical Manufacturers Association (CMA).
• The EPA OAQPS and the Division of Stationary Source Enforcement
(DSSE) were also consulted.
Appendix B lists the locations, dates, and purposes of the meetings held
with industry and EPA personnel.
2.3 THE VC EMITTING INDUSTRY
2.3.1 Current Number And Geographical Distribution
There are 39 operating PVC plants and 18 operating EDC/VC plants (1
producing EDC only) in 18 states and 7 EPA regions. Table 2-3 shows the
2-9
-------
Table 2-3. GEOGRAPHIC DISTRIBUTION OF OPERATING
VINYL CHLORIDE-EMITTING PLANTS
Region
I
II
III
IV
V
VI
IX
State
Massachusetts
New Jersey
New York
Delaware
Maryland
Pennsylvania
West Virginia
Florida
Georgia
Kentucky
Mississippi
Illinois
Michigan
Ohio
Louisiana
Oklahoma
Texas
California
TOTAL PLANTS
No. of PVC plants
3
6
1
2
1
1
1
1
1
2
1
2
1
2
5
2
4
_3
39
No. of EDC/VC plants
0
0
0
0
0
0
0
0
0
1
0
0
0
0
11
0
5
_1
18
2-10
-------
distribution of these plants throughout the United States. (See Appendix C
for identification of these plants). The number of EDC/VC plants has
increased from 15 prior to promulgation of the regulation to 17 plants
currently in operation. Two of the original plants discontinued operation
and four new plants began operation. These new plants are identified in
Appendix C. During this period the approximate VC nameplate production
capacity increased from 3.1 teragrams (6820 million pounds) per year in
1974 to 3.7 teragrams (8200 million pounds) per year in 1980 (EPA, 1975;
Chemical Week, 1980a).
The number of operating PVC plants has remained consistent since
promulgation of the regulation. Of the 41 original PVC plants, 4 plants
have discontinued operation and 3 new plants have begun operation.
These newer larger plants, along with extensive expansions at several
other existing plants, have resulted in an approximate increase in PVC
nameplate production capacity from 2.6 teragrams (5739 million pounds)
per year in 1975 to 3.4 teragrams (7600 million pounds) per year in 1980
(EPA, 1975; Chemical Week, 1980b).
2.3.2 Influence of the Standard on Industry
Promulgation of the regulation was followed by significant changes
in the VC industry. These changes included plant and equipment moderni-
zation, process modifications, and redirection of some research and
development resources from the product itself to the areas of environ-
mental control. Economically, these changes were felt most acutely by
the older PVC plants that had to retrofit their processes with new
controls. Several EDC/VC and PVC plants were still in the design phase
during development of the regulation and the engineering was altered to
accommodate the new requirements.
The cost (of compliance) to the VC industry for a 10-year period
(1977-1986) is estimated to be $765.7 million (1977 dollars). This
includes investments, capital, operating and maintenance costs for new
and existing plants (EPA, 1979).
A survey of 14 PVC producers indicated a 10-to-12 percent average
loss in production capacity as a result of compliance requirements
(Chemical Week, 1979). The reasons for lost capacity were due mainly to
the time needed to clean reactors and purge the different systems in an
2-11
-------
effort to reduce VC emissions prior to opening to the atmosphere. The
PVC process may also need to be operated at a slower rate to strip
residual VC (RVC) from PVC resins in order to reduce emissions. The
production loss varies with the type of resin produced and stripping
technology used.
EDC/VC plants have expended capital to comply with the regulations,
mainly for add-on control equipment and modifications to processes.
Furthermore, state agencies regulating hydrocarbon emissions are stimu-
lating new technology for emission reduction. The main emphasis has
been in changing from air processes to oxygen processes in the EDC
process. This results in a lower volume emission to be combusted.
At the time of this review study, most of the EDC/VC and PVC plants
have completed many of the modifications discussed above and are
channeling their research and development resources back to product
development. Relatively few plants have ceased production during the
last 4 years. No EDC/VC plants have shut down; seven PVC plants have
closed (four on a temporary basis). Construction of new or modified
sources is currently underway in many regions.
2.3.3 Industrial Trends
From the standpoint of process and control, there is a significant
trend in the industry towards automation and computerization. Among
plants surveyed during the review study, processors utilizing these
types of advanced systems have attained a high level of compliance.
There is a definite trend toward the use of larger reactors in the
PVC industry. Economic and emission control advantages of these larger
systems are discussed in Section 4.0.
The tendency to minimize the number of PVC resin grades has also
been noted. The "grocery store" processor, with many small reactors
producing multiple grades of resin, is leaning towards the processing of
fewer grades. One reason for this change is the difficulty and amount
of time required for stripping RVC from certain specialty resins (as
mentioned above).
Reduction of energy consumption at EDC/VC plants is also being
achieved through various process modifications. Steam consumption has
been greatly reduced by Stauffer Chemical who uses the EDC reactor heat
2-12
-------
in their purification reboilers and B.F. Goodrich who uses the heat of
reaction for purification (McPherson, 1979). Many companies are also
devoting more effort to make the "cracking" of EDC to form VC more
efficient and eliminate unwanted byproducts originating from side
reactions during the cracking. These trends will be discussed in more
detail in later sections.
The VC industry is currently experiencing a sales decline due to
the recession that occurred in early 1980. This decline is due mainly
to the depressed construction industry, a major consumer of PVC pipe.
(Forty percent of the PVC used in the United States goes into the
manufacture of pipe.) Because 96 percent of the VC produced by EDC/VC
plants is used in the PVC industry, a domino effect occurs. Currently,
EDC/VC producers are running their plants at an average 86 percent of
the first-quarter 1980 nameplate capacity while PVC producers are
running their plants at an average 65 percent of the first-quarter 1980
nameplate capacity (Chemical and Engineering News, 1980a; 1980b).
2-13
-------
2.5 REFERENCES FOR CHAPTER 2
Chemical and Engineering News. 1980a. "Vinyl Chloride." July 7, 1980,
p. 9.
Chemical and Engineering News. 1980b. "Polyvinyl Chloride." October 6,
1980, p. 13.
Chemical Week. 1979. "At PVC Plants, Compliance Curbs Capacity." March 28,
1979, p. 36.
Chemical Week. 1980a. "PVC Growth Plans Lead to Big VCM Expansions."
February 13, 1980, p. 26.
Chemical Week. 1980b. "PVC: Big Plans Match Growth Forecasts." January 16,
1980, p. 33.
Environmental Protection Agency. 1975. Standard Support and Environmental
Impact Statement: Emission Standard for Vinyl Chloride, EPA-450/2-75-009.
October 1975.
Environmental Protection Agency. 1979. Report to Congress. Document
#96-38. "Cost of Clean Air and Clean Water," Vinyl Chloride Air
Pollution Control Costs. December 1979, p. 56.
McPherson, R. W.; Starks, C. M.; and Fryar, G. I. 1979. "Vinyl Chloride
Monomer . . . What You Should Know," Hydrocarbon Processing. March 1979,
p. 36.
2-14
-------
3.0 PROCESS DESCRIPTION
3.1 INTRODUCTION
This chapter describes processes used to produce vinyl chloride
(VC) and to polymerize VC into polyvinyl chloride (PVC) resins. The
most common method used for production of VC is dehydrochlorination
(cracking) of ethylene dichloride (EDC). Currently, there are four
polymerization processes being used to produce polyvinyl chloride resins
from VC.
Approximately 87 percent of the EDC, or 1,2 dichloroethane, produced
in the United States is used to produce VC. Current commercial processes
that manufacture EDC for production of VC use a combination of ethylene,
chlorine, and oxygen (usually in the form of air) for feedstocks.
Hydrogen chloride (HC1) recycled from the cracking of EDC is also used
as feedstock. In general, the production of EDC is an intermediate step
in a combination of processes known as the "balanced process" for the
production of VC. Figure 3-1 shows a simplified process flow diagram of
an EDC/VC plant using the "balanced process." Table 3-1 summarizes the
potential emission points and regulation requirements for control of
each point in each process step shown in Figure 3-1. The requirements
of the regulation will be discussed in more detail as the different
process steps are described.
Polyvinyl chloride is one of the most versatile thermoplastics
manufactured in the United States today. PVC resins are noted for their
excellent chemical and physical properties. They are easy to process,
cost relatively little to make, are self-extinguishing (when ignition
source is removed) and can be compounded with other resins (Shreve,
1977, p. 589). Products fabricated from PVC resins can be either
flexible or rigid.
-------
CO
ro
Proem Sttpt
Olnct ChlorlMtlm
T) EOC PurirtcitlM
T) -In Prams' MitMter Jtrlpfwr
7) tayctilorlMtlan
T) VC Crtcklng ind hiHflcitton
VC Ludlng and Stor«jt
Figure 3-1. EDC/VC "Balanced Process" flow diagram.
-------
Table 3-1. POINT SOURCE EMISSIONS
"BALANCED PROCESS" EDC/VC PLANTS
Process step
Potential emission points
Regulation requirements
1 Direct chlorination
2 EDC purification
CO
CO
"Inprocess" wastewater
stripper
Oxychlorination
VC cracking and
purification
VC loading and storage
Product condenser
EDC crude storage, light ends
column condenser, light ends
storage tank, heavy ends
column condenser, heavy ends
storage tank
Wastewater storage tank
Wastewater stripper column
Water wash column
Oxychlorination process vent
Separator tank
EDC quench column
HC1 column vent
VC column condenser
Loading lines
VC storage tanks
Not regulated
All emission points are required
to be controlled to._<_ 10 ppm
VC removed from inprocess water is
to be ducted to a control system from
which concentration of VC in exhaust
gas does not exceed 10 ppm
Emissions from reactor are not to
exceed 0.2 g VC/kg of the 100 percent
EDC product
Concentration in all exhaust gases
must not exceed 10 ppm
Emissions from loading lines must be
reduced so that upon opening of line
to the atmosphere emissions do not
exceed 0.0038m3 of VC at STP. VC
removed from lines to meet this
criteria must be controlled to _<_ 10
ppm upon exhaust to the atmosphere.
Concentration of VC in exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
-------
Consumption of PVC resins totalled 2.6 teragrams (5.6 x 109 pounds) in
the United States in 1978, and consumption of PVC thermoplastics was
second only to consumption of low density polyethylene (Hatch, 1979,
p. 176).
3.2 PRODUCTION OF ETHYLENE BICHLORIDE (EDC)
In the "balanced process" (see Figure 3-1), ethylene dichloride is
produced by two different methods 1) direct chlorination, and 2) oxy-
chlorination. EDC is first produced by direct chlorination of ethylene
(CH2CH2) with chlorine (CU). Direct chlorination may be simply expressed
as
CH2CH2 + C12 catalyst> CH2C1CH2C1.
This process varies with the technology employed but usually yields a
high conversion rate; approximately 95 percent to 98 percent of the
ethylene reacts and 99 percent of the chlorine reacts (Nass, 1977,
p. 20). Byproducts and unreacted chlorine and ethylene are removed
during purification by scrubbing and distillation. The purified and
dried EDC is then "cracked" (dehydrochlorination by pyrolysis) to produce
VC. Approximately one mole of hydrogen chloride (HC1) is produced for
every mole of VC formed during the cracking process.
The HC1 byproduct from cracking is recycled as a feedstock to form
EDC by a second process, oxychlorination. The reaction that occurs in
the oxychlorination reactor may be simply expressed as
CH2CH2 + 2HC1 + J$02 catalyst } o^ClO^Cl + H20.
An oxychlorination reactor uses the available HC1 formed from the EDC
cracking process in the "balanced process." EDC produced in the oxy-
chlorination reactor is usually routed through the same purification
system used for the direct chlorination reactor.
There are currently a number of licensed process variations for
EDC/VC production. The most common licensors in the United States are
B. F. Goodrich, Stauffer Chemical, Pittsburgh Plate Glass, Dow Chemical,
and Ethyl. In some instances, combinations of these process variations
are used.
Section 61.60(a)(l) of the regulation states that EDC production by
reaction of 02 and HC1 with CH2CH2 (oxychlorination) is subject to
3-4
-------
requirements in the regulation of EDC production (see Table 2-1). The
direct chlorination step used to produce EDC is not required to meet
stipulations of the regulation. Regulation of the oxychlorination step
is needed because HC1 generated in the cracking furnace, which is recycled
for oxychlorination feedstock, contains VC, which is also formed as a
byproduct in the oxychlorination reactor. Therefore, VC may be released
from the oxychlorination vent and may contaminate the EDC product stream.
3.2.1 Direct Chlorination of Ethylene
Typically, direct chlorination of ethylene is carried out in a
liquid-phase reactor. Although vapor-phase reactors are available,
better temperature control is realized with the liquid EDC medium, and
dilution gas for safety reasons is not necessary. In the liquid-phase
reactor, the reactants (ethylene and chlorine) are bubbled up through
liquid EDC. Mechanical agitation may also be used to promote solubility
(Nass, 1977). Operating temperatures normally range from 50°C (120°F)
to 70°C (160°F) and pressures range from 400 kilopascals to 500 kilo-
pascals (4 atmospheres to 5 atmospheres) (Nass, 1977, p. 20). Metallic
chlorides may be used as catalysts for this free radical process. Iron
chlorides seem to be most prevalant in commercial processes, although
aluminum, copper, and antimony chlorides are also used (Milby, 1978,
p. 16).
The EDC product from direct chlorination may be contaminated with
1,1,2 trichlorethane and the metal chloride catalyst, both of which must
be removed before the EDC can be cracked to VC. Although direct chlori -
nation has not been cited as being a source of VC emissions and is not
subject to the regulation, the operations could possibly become contami-
nated by VC. If ethylene separated from vent or product gases in the
oxychlorination reactor is recycled to the direct chlorination process
(McPherson, 1979, p. 78), the ethylene could be contaminated by VC
formed as a byproduct in the oxychlorination reactor.
3.2.2 Oxychlorination of Ethylene
An important development in the "balanced process" was the start-up
of the first large scale oxychlorination unit in 1958. The oxychlori-
nation process (see Figure 3-1) allows the production of VC from two
3-5
-------
chemical feedstocks, chlorine and ethylene, without coproduct formation
(McPherson, 1979). The process can take place in two types of reactors,
a fixed-bed reactor or fluidized-bed reactor. Fluidized-bed reactors
are capable of better temperature control because of the excellent
intermixing of reactants and catalyst.
In the fixed-bed reactor, the catalyst is packed in tubes; however,
hot spots can form in the reactor tubes if the catalyst migrates (usually
in the direction of process flow). Heavy concentrations of catalyst in
one or more areas accelerates the reaction rate and the subsequent
heating may cause an increase in byproduct formation.
Temperature control in the oxychlorination reactor is important
whether fixed-bed or fluidized-bed configurations are used. If tempera-
tures exceed 325°C (600°F), an increase in byproducts such as VC is
noted along with the burning of ethylene to form carbon monoxide (CO)
and carbon dioxide (C0?). An increased deactivation of the catalyst may
also occur at the higher temperatures (McPherson, 1979, p. 78).
All oxychlorination reactors use copper chloride for the reaction
catalyst (Albright, 1967, p. 219). Sodium or potassium chloride can be
mixed with the copper chloride to lower the melting temperature of the
salt mixture and to reduce the vapor pressure of the copper chloride,
hence increasing catalyst life. Catalyst for both types of reactors is
supported on a solid porous material such as alumina or silica.
A new oxychlorination process has been developed by the M. W. Kellogg
Company. In this process an aqueous solution of copper chlorides is
used as catalyst and reactants are bubbled up through the catalyst.
Some of the advantages of this process are high product yield, excellent
temperature control, the use of aqueous solutions of HC1 as feedstock,
and simultaneous chlorination as well as oxychlorination (Nass, 1977,
p. 23). There are no known commercial producers currently using the
M. W. Kellogg process of oxychlorination.
Oxychlorination reactors incorporate large rupture discs as a
safety measure. The rupture disc would allow pressure to escape to the
atmosphere in the event of an explosion. Over-pressure due to an
accelerated reaction is not an item of concern (DiBernardi, 1980).
Thus, there are no specific requirements in the regulation for rupture
discs on oxychlorination reactors.
3-6
-------
The oxychlorination process vent is subject to the current regulation.
Emissions from oxychlorination reactors must not exceed 0.2 grams of VC
per kilogram of the 100 percent EDC product. This emission limit can be
met by an add-on control device such as an incinerator or by process
modifications.
The use of oxygen instead of air in the formation of EDC by this
process greatly affects the quantity of inerts (e.g., nitrogen) that are
vented from the oxychlorination process. When air is used as a feedstock
material, emissions from the oxychlorination vent are large in volume
and low in hydrocarbon content. Large amounts of inerts increase the
work that must be done to condense the product stream in order to separate
EDC and unreacted ethylene.
Byproducts found in the oxychlorination product stream can include
VC, vinylidene chloride, ethyl chloride, 1,1-dichloroethane, 1,2-dichloro-
ethylene, trichloroethylene, chloroform, carbon tetrachloride, methyl
chloride, methylene chloride, chloral, and high boiling compounds (McPherson, 1979,
p. 78). These byproducts must be removed prior to cracking the EDC to
produce VC.
Acetylene in the HC1 feedstock recycled from the cracking furnace
is used to form 1,1,2 trichloroethylene. This byproduct is not easily
removed in the EDC purification step and reduces product yield in the
cracking furnace. One method of eliminating 1,1,2 trichloroethylene
formation is hydrogenation of the HC1 feedstock. Hydrogenation is a
catalytic reaction that eliminates the acetylene by converting it to
ethylene.
3.2.3 Purification of Ethylene Pi chloride
In order to prevent fouling of the dehydrochlorination reactor
(cracking furnace), the EDC cracked to form VC must be highly pure, at
least 99.5 percent. Also, any moisture in the stream must be removed to
prevent corrosion in equipment from the HC1 generated during the cracking
process. Typically, process vent streams purified are those from direct
chlorination of ethylene, oxychlorination of ethylene, and EDC recovered
from the dehydrochlorination process (see Figure 3-1). Because the
purification process is used to purify EDC recycled from the oxychlorination
3-7
-------
unit and the cracking furnace, VC contamination is possible. For this
reason Section 61.62 requires that all exhaust gases discharged to the
atmosphere from the purification process not exceed 10 ppm VC unless the
equipment is out of service or opened. Prior to opening any equipment,
Section 61.65(b)(6) of the regulation requires that the quantity of VC
in the purification equipment be reduced to 2.0 percent by volume or
0.0950 cubic meters (25 gallons), whichever is larger, at standard
temperature and pressure (STP).
The first step of EDC purification is usually a water quench followed
by caustic scrubbing. This step removes catalyst and unreacted chlorine
from the direct chlorination process stream.
Water that comes in contact with VC is termed "inprocess wastewater."
This water is returned to the process or must meet "inprocess wastewater"
requirements of the regulation before being discharged to other wastewater
treatment facilities. The current regulation prohibits the discharge of
"inprocess wastewater" containing more than 10 ppm VC.
Water and low-boiling impurities such as VC, ethyl chloride,
vinylidene chloride, chloroform, and methyl chloride, generated in the
oxychlorination reactor, are removed by a light ends distillation column.
Pure, dry EDC is taken overhead from a second distillation column which
removes compounds of a higher boiling temperature. Gases taken overhead
from the light ends distillation column are stored in a recovery tank
and may subsequently be sold. Tars from the heavy ends distillation
column can be fractionated to recover soluble components and the remains
incinerated to recover chlorine as HC1 (McPherson, 1979, p. 80). All
vent gases from processes and storage vessels in VC service (defined in
the regulation as containing 10 percent by volume or more VC) are required
to be controlled to 10 ppm or less VC.
Ethylene dichloride condensed from the dehydrochlorination process
stream requires purification to remove byproducts formed during cracking.
Special treatment is needed to remove chloroprene which can polymerize
inside the light ends distillation column and trichloroethylene which
forms an azeotrope (mixture with constant boiling point and distilling
off in a fixed ratio) with EDC. Trichloroethylene may inhibit dehydro-
chlorination if allowed to accumulate in the EDC. These two byproducts
3-8
-------
are usually removed by chlorination prior to distillation (McPherson,
1979, p. 79).
A method for formation of HC1 from the light and heavy ends
distillation column byproducts has been developed. The method employs
catalytic oxidation of the byproducts separated by the purification
columns with air and other added reactants. The HC1 formed by this
method is used as feedstock for the oxychlorination unit.
3.3 PRODUCTION OF VINYL CHLORIDE
All VC is currently produced in the United States jointly with EDC
using the "balanced process" method; however, VC manufactured by any
process is covered by the current regulation (see Table 2-1). VC
concentrations in all exhaust gases from the formation (cracking) and
purification of VC cannot exceed 10 ppm.
3.3.1 Formation of Vinyl Chloride by Dehydrochlorination of EDC
Thermal dehydrochlorination, commonly known as cracking, is the
separation of hydrogen and chlorine from 1,2-dichloroethane (EDC) yielding
vinyl chloride (CH2=CHC1) and hydrogen chloride (HC1) at about a one to
one molar ratio. The cracking of EDC may be simply expressed as
CH2C1CH2C1 »• CH2CHC1 + HC1.
The non-catalytic method seems to be preferred over the catalytic method
(Nass, 1977). The typical cracking furnace operates at pressures between
2 megapascals to 3 megapascals (20.0 atmospheres to 30.0 atmospheres)
and at temperatures between 450°C to 650°C (840°F to 1,200°F) (Albright,
1967, p. 223). Operating the furnace at high pressures results in an
increased yield, fewer byproducts, and allows easier separation of the
VC product from unreacted EDC and byproducts. Conversion rates are
normally kept between 50 percent and 60 percent in order to minimize
byproduct formation. Research is continuing in the development of
cracking promoters and inhibitors of side reactions in pyrolysis chemistry.
Considerable energy and cost savings could be achieved through increased
conversion levels without concurrent losses of EDC to undesirable side
reactions (McPherson, 1979, p. 87).
The process stream from the cracking furnace is condensed to separate
the VC product and unreacted EDC which is recycled back to the process
3-9
-------
(see Figure 3-1). Some systems quench the process stream with crude EDC
to reduce formation of byproducts and to partially condense EDC from the
product. Byproducts formed in the furnace reactor tubes in addition to
HC1 are tars, carbon, chloroprene, butadiene, and trichloroethane.
Carbon and tars tend to foul reactor tubes in the furnace so the tubes
need to be opened and cleaned periodically.
3.3.2 Purification of Vinyl Chloride
The VC in the product stream from the cracking furnace must be
separated from byproducts formed during cracking and unreacted EDC (see
Figure 3-1). The first step in purification of the product stream as
mentioned above is normally a quench of the hot effluent with liquid EDC
or the condensation product from the cracking furnace. The product
stream exits the quench column and is condensed and fed to a distillation
column. In this column, HC1 is separated from the product stream.
Acetylene and some ethylene byproducts will also come off with the HC1,
and HC1 treatment by hydrogenation may be necessary if the HC1 is to be
used as a feedstock for the oxychlorination step. The EDC, VC, and
remaining byproducts are then fed to a second distillation column where
VC is distilled.
Methyl chloride and butadiene will come off with VC, depending on
the efficiency of the fractional distillation system. Methyl chloride
formation in the cracking furnace can be reduced by addition of chlorine
or anhydrous HC1, or by selective hydrogenation (Nass, 1977). The
remaining crude EDC is returned to the EDC purification step of the
process. The VC taken overhead from the second column is stored in
pressurized vessels for eventual shipment to PVC plants or other
facilities using VC. In instances where the PVC plant is very close to
the VC producer, VC can be delivered by pipeline.
3.3.3 Emissions for Typical EDC/VC Plants
Prior to promulgation, EPA estimated VC emissions from the 17
existing EDC/VC plants to be approximately 11 gigagrams (24.2 million
pounds) or approximately 15 percent of the nationwide VC emissions (EPA,
1975). The original study done in support of the existing regulation
identified uncontrolled VC emissions from four areas within an EDC/VC
3-10
-------
plant producing 316 gigagrams per year (700 million pounds per year).
These four areas were the EDC purification light ends vents, the VC
finishing column, the oxychlorination vent and fugitive emissions sources
(see Figure 3-1). Total emissions from this plant were calculated to be
approximately 1.4 gigagrams (3.1 million pounds) of VC per year.
3.4 PRODUCTION OF POLYVINYL CHLORIDE
Four polymerization processes are being used currently to manufacture
PVC resins:
• suspension,
• dispersion (emulsion),
• bulk (mass), and
• solution.
Figure 3-2 shows a generic flow diagram for PVC production by the suspension
and dispersion processes. The potential emission points for each of the
process steps shown in Figure 3-2 are listed in Table 3-2 along with a
summary of regulation requirements for control of emissions.
Many companies have licensed some phase of their particular process
such as stripping technology or clean reactor technology which will be
discussed in subsequent sections. The licensing of these process phases
has evolved from the intensive research work done to reduce residual VC
(RVC) levels in finished resins, limit worker exposure, and reduce
emissions to the atmosphere.
After polymerization, VC may be present in any of three forms in
the polymerization reactor depending on the particular process. VC will
always be present separately as a gas or liquid in the reactor and will
also be trapped within the newly formed polymer resin. In the suspension,
dispersion, and solution processes, VC will also be trapped in the
process water.
The resins produced by a process are categorized as to the "type"
of resin. Those processes responsible for more than one variation of
their type of resin are further subdivided into "grades." The resin
grade is developed to allow compounding and fabrication to yield the
desired product. Figure 3-3 shows the resin types, the compounds, and
the various fabrication processes. PVC fabrication will be discussed in
more detail in Section 6.1.1.
3-11
-------
Recovered VC
CO
i
«-•
ro
ID
!2>
!«
T r
j Lv
"In Process"
Uaste Water
from Double Mechanical
on all Pumps,
Compressors and Agitators
H20 from Reactor Evacuating
Prior to Opening
Knock-out Pots
H20
Seals
PVC Storage
md Shlpplnc
Polymerization
Reactor
Polymer
Stripping
Vessel
¥ i
Blend Tanks
i
^J/ n vfc^
f"i
entrlfuqe I
I
Vent to
Control Device
Process Steps
VC Unloading and Storage
Nixing. Weighing and Holding
Polymerization Reaction
Resin Stripping
Recovery System
Blending
Drying
PVC Storage
"In Process" Wastewater Stripping
Figure 3-2. Suspension and dispersion processes flow diagram.
-------
Table 3-2. POINT SOURCE EMISSIONS TYPICAL OF
SUSPENSION AND DISPERSION PVC PLANTS
Process step
Potential emission points
Regulation requirements
VC unloading and storage
u>
Mixing, weighing and
holding tanks before
stripping operation
Polymerization
Stripping
Loading lines, VC storage tank
Mixing, weighing and holding
tank vents
Polymerization reactor opening
loss (ROL)
Polymerization reactor relief
valve discharges
Polymerization reactor rupture
disc discharges
Stripping vessel vent
Emissions from loading lines must be
reduced so that upon opening of line
to the atmosphere emissions do not
exceed 0.0038nr of VC at STP.
VC removed from lines to meet this
criteria must be controlled to <_ 10
ppm upon exhaust to the atmosphere.
Concentration of exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
ROL from each reactor is not to exceed
0.02 g VC/kg PVC products.
No discharge to the atmosphere except
for an emergency relief discharge
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm. Not required to be
reported.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
(continued)
-------
Table 3-2. Concluded
Process step
Potential emission points
Regulation requirements
co
i
8
9
Monomer recovery system
Blending (mixing,
weighing and holding
tanks after stripping
operation)
Drying, sizing, screening
of dewatered resin
PVC loading and storage
"In Process" wastewater
stripper
Recovery system exhaust
vent knock-out pot
Slurry blend tanks and
holding tank vents
Centrifuge vents, dryer vent
stacks, storage silos, baghouse
vents, screening operation vents
Storage silos
Waste-water storage tank
waste-water stripper column
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
Not regulated.*
Not regulated.*
Not regulated.*
VC removed from in process water is
to be ducted to a control system from
which concentration of VC in exhaust
gas does not exceed 10 ppm.
*If a PVC plant is using stripping to control VC emissions, emission sources beyond the stripper
are not regulated.
-------
CO
i
Polymerization
Process
Suspension*
Bulk
(Mass)
Dispersion
(Emulsion)
Solution
Resin
Type
Suspension
Blending
->- Bulk
Dispersion
Latex --
Solution
Compound
Rigid
Flexible^-V -
Plastisol
$»- Organosols O
\. \
Latex
Solution— _
Fabrication Process
Extrusion
Calendering
Injection Molding
Compression Molding
- .^Low-Pressure
Injection Molding
\ Blow Molding
\
X> ^
x v Slush Molding
i
Rotational Casting
Coating & Casting
Processes
*Latices are usually sold directly to the consumer rather than being used in later
fabrication processes.
Figure 3-3. Polyvinyl chloride resins, PVC compounds and PVC fabrication processes.
-------
A plant manufacturing polymers containing any amount of polymerized
VC is subject to the current regulation. The requirements of the regulation
listed in Table 3-2 will be discussed in more detail below.
3.4.1 Free Radical Polymerization
Polymerization is the chemistry of combining simple molecules
(monomers) into long chains of repeating molecular units (polymers).
There are two types of polymerization - addition and condensation. PVC
resins are commerically produced by addition polymerization and, in
general, polymerization is induced by the use of free radical initiators
(Nass, 1977, p. 34). Thermal decomposition of the initiator, which is
combined with the VC and other constituents in the polymerization reactor,
yields free radical molecules having one unshared electron. This free
radical reacts with additional VC molecules by removing an electron from
the VC double covalent bond and sharing an electron with the free radical.
The remaining unshared electron moves along the chain becoming the new
radical bond site. Another VC molecule may then become a part of the
polymer chain by reacting with the polymer radical,
H Cl H Cl
'I I !
R- + C = C » R - C - C-
I ! II
H H H H
Radical + VC molecule »• Polymer radical
Radicals are transferred from the polymer by a reaction with a VC
monomer to yield a polymer and free radical. The transfer reaction
increases with increasing temperatures. This characteristic of the
reaction kinetics allows a desired molecular weight to be obtained by
controlling reaction temperature (Cameron, 1979, p. 39). Radicals are
also transferred by reacting with hydrogen atoms obtained from VC or
solvent in the reactor. Another way of transferring radical sites from
the growing polymer chain is by using chain transfer agents (CTA).
These CTA's are used to regulate the molecular weight of the polymer to a
desired level. In all transfer reactions, the radical is released and
able to initiate another polymerization reaction. The reaction is
terminated when two polymers with radical sites are combined. Polymerization
rate is controlled by choice of the appropriate initiator.
3-16
-------
The polymerization reaction is exothermic and the reaction rate
must not be allowed to accelerate to the extent that the heat of reac-
tion cannot be removed by reactor cooling devices. Reaction rates tend
to increase as the temperature increases. If the heat of reaction is
not removed, a runaway reaction can develop and the rapid increase in
temperature will increase the pressure inside the reactor vessel beyond
safe limits.
The monomer structure of VC is capable of several variations in
chain structure, but free radical polymerizations generally produce
atactic structures (random orientation of monomer unit in chain struc-
ture) (Nass, 1977, p. 46). Tendency towards syndiotactic structure
(regular alternating orientation of the monomer unit in the chain struc-
ture) and crystal!inity are both increased by reduced polymerization
temperatures.
3.4.2 Unloading of VC at PVC Plant Sites
Under the current regulation VC emissions from loading and unloading
lines, which are opened to the atmosphere, must be reduced in the opened
lines to 0.0038 cubic meters (0.13 cubic feet) or less at standard
temperature and pressure. Also, the VC removed from loading and unloading
lines in order to meet this requirement of the regulation must be vented
to a control system from which the concentration of VC in the exhaust
gas does not exceed 10 ppm (see Table 3-2). When PVC plants are not
located close enough to receive VC by pipeline, it is shipped by railcar,
tank car, barge or marine vessels.
The VC is normally unloaded at PVC plants by displacement. This is
accomplished by pumping vapor from storage tanks into the transfer
vessel which displaces the liquid VC from the transport vessel through
the unloading line. When the liquid VC is displaced, the compressor
line is reversed and used as suction to evacuate remaining liquid as
vapor. The remaining liquid VC is allowed to boil during tank car
evacuation for its removal as a gas. This vaporization of the VC usually
takes 20 to 30 minutes (Mukerji, 1977, p. 155). Lines between tank car
compressor and storage tank can be switched without disconnection by
incorporating a 4-way valve in the pumping lines. Instrumentation of
3-17
-------
the system usually incorporates a turbine meter, a flow totalizer to
measure the VC flowrate and quantities unloaded, and storage tank level
indicators.
Unloading and transfer lines may be purged with nitrogen to reduce
VC to the required level before disconnection of the unloading lines.
In some cases, the portion of the unloading line which is opened to the
atmosphere has been reduced to diminish the amount of VC that will
escape to levels below those required by the regulation.
3.4.3 Mixing, Weighing and Holding Vessels
Storage spheres, storage tanks, weigh tanks, gasholders, wastewater
storage tanks, knockout pots, and surge tanks are representative of
vessels covered under Section 61.64(c) of the regulation for mixing,
weighing, and holding vessel (see Table 2-1). These vessels are used to
hold liquid or gaseous VC and PVC slurry during various stages of the
PVC process. Some of these vessels were open to the atmosphere prior to
promulgation of the VC regulations, but have since been enclosed and are
usually ducted to the recovery system and/or the primary control device.
The number and types of vessels will vary from plant to plant depending
on the size and type of process used to produce the PVC resin.
Section 61.64(c) of the regulation requires the concentration of VC
in all exhaust gases discharged to the atmosphere from mixing, weighing,
and holding containers "in-VC-service" not to exceed 10 ppm (see Table 3-2).
Any piece of equipment that contains or contacts a fluid that is 10 percent
by weight, VC, or gas that is at least 10 percent by volume, is considered
"in-VC-service." There are no requirements in the regulation for mixing,
weighing or holding containers used in the process after the stripping
of the PVC resin provided resin stripping is used.
3.4.4 Suspension Polymerization
The suspension process for producing PVC resins (see Figure 3-3) is
characterized by the formation of polymers in droplets of the liquid VC
(or other co-monomers) suspended in water. These droplets are formed by
agitation and the use of protective colloids or suspending agents.
Protective colloids commonly used are water-soluble polymers such as
modified cellulose or partially hydrolyzed polyvinyl acetate. The
3-18
-------
process is started by evacuating the polymerization reactor to remove
oxygen and other contaminants that may inhibit the reaction initiator
(see Section 3.3.1). Water and VC may be simultaneously added to
the reactor with the protective colloids, or they may be added separately
(water and colloids first, followed by the liquid monomer). The water
used is deionized and deaerated in order not to inhibit free radical
initiator formation. Water and other ingredients charged to the reactor
must be carefully measured prior to charging because a level indicator
for reactors has not been commercially developed. In some cases the
reactor is on a scale and the amount of material charged is weighed in
the reactor. More often, a separate weigh tank is used to measure
materials charged to the reactor. A flow meter can be used to record
the amount of water added. Reactor operators manually charge additives
that are used in small proportions. The initiator is usually the last
ingredient charged to the reactor. Initiators commonly used in the
suspension process are peresters, peroxycarbonates, peroxides, or azo
compounds. The initiators are soluble in VC and allow formation of PVC
in the monomer droplets.
After all materials are in the reactor, the batch is brought up to
the reaction temperature by passing steam through the reactor jackets
which allows free radical initiators to be formed. Reaction temper-
atures are varied in order to produce a resin grade of a particular
molecular weight. Once polymerization is initiated, the reaction becomes
exothermic and cooling water must be circulated through the reactor
jacket to remove heat of reaction. In some instances reflux condensers
have also been used to control reaction temperature and remove excess
heat.
After approximately 6 hours in the reactor, the batch temperature
and pressure drop. This signifies that nearly all the VC has reacted
(75 percent to 90 percent of the VC usually reacts) and the remaining or
residual VC (RVC), which is in a liquid or gaseous state or trapped in
the resin particles, must be stripped. This RVC is usually stripped
with steam under vacuum. The suspension process yields a particle size
distribution of a much wider range than the other polymerization pro-
cesses. Particle size may range from 90 micrometers to 130 micrometers
(0.0035 inches to 0.0050 inches) with low to medium molecular weights.
3-19
-------
The regulation requires that RVC levels for suspension resins not
exceed 400 ppm of the PVC product. PVC resin, unreacted VC (in the
water, in the headspace, and trapped in the resin) and water are the
constituents remaining in the reactor after polymerization. This polymer
slurry may be steam-stripped of RVC batchwise in the reactor or in a
separate vessel. B. F. Goodrich has developed a continuous stripping
operation which strips the resin with steam running countercurrent to
the PVC slurry. Most plants strip batchwise with steam in separate
vessels or in the continuous stripping column. In all cases, water
accompanying the PVC product is stripped with the slurry and then removed
by centrifugation.
Batch stripping procedures use temperatures up to 87°C (190°F) and
a vacuum of 91 kilopascals (27 inches of mercury) or more (Mass, 1977,
p. 83). Heat is applied by steam injected directly into the batch or by
steam passed through the reactor wall jackets. If stripping is used to
meet RVC levels, any downstream processes or equipment (e.g., water
treatment, vents from mixing tanks, centrifuges, dryers, etc.) are not
required to meet any other requirements of the regulation.
After stripping, the batch is transferred to blend tanks which mix
the batch with other batches to ensure product uniformity. The mixed
batches are then fed to a continuous centrifuging operation that separates
the polymer from the water in the slurry. Both mixing tanks and centri-
fuges are vented to the atmosphere if stripping is utilized. The water
from centrifuging is not required to be stripped of VC because most of
the VC is removed during resin stripping. Therefore, the centrifuge
water is recycled back to the process or discharged to the plant's
wastewater treatment system.
The wet cake from centrifuging is conveyed to a rotary dryer for
further removal of the remaining (usually 25 percent) moisture (Mass,
1977, p. 83). Most of the RVC not removed during stripping will be
released during the drying operation. Counter-current air temperatures
in the dryer range from 65°C to 100°C (150°F to 210°F). Drying time is
generally short, but large volumes of air containing RVC are released.
After drying, the resin may be screened to remove agglomerates. The
resin is then bagged or stored in silos for bulk shipment by trucks or
rail car.
3-20
-------
Uniformity of suspension resin batches is dependent on control of
variables such as:
• impurities (noncondensable gases present in the reactor prior
to polymerization or impurities in raw materials charged to
the reactor),
• rate of temperature increase to reaction temperature,
• agitation speed and schedule (speed varies as the slurry
becomes more dense),
t charging rate of raw materials, and
• temperatures of raw materials charged.
In some of the newer PVC facilities these variables are closely monitored
by levels of computer control. In the older plants many variables such
as cooling water flow rates, pump operation, agitator motors, temperature,
and pressure are monitored and controlled manually from the control room
panel or at the reactor. More versatility is possible with computer
assistance. A reactor linked to computerized control elements can
produce different grades of resin by using programs designed to yield
specific reactor conditions (e.g., agitation, temperature, amount, and
type of materials charged) that will produce the desired resin product.
Computers can also monitor operating conditions and respond to emergencies
(such as high pressure in the reactor). They can be programmed to take
necessary action to bring an upset condition under control, e.g., choosing
the best compensatory action.
The use of large reactor systems has increased quality control and
allowed incorporation of equipment and procedures that reduce VC emissions.
Large reactors, approximately 8,000 gallons (30 cubic meters) and up,
offer lower plant cost, improved product uniformity, and increased
productivity. A more detailed discussion of reactors is included in
Section 3.4.8.
3.4.5 Dispersion Polymerization
Although dispersion (emulsion) resins are formed in reactors similar
to those used for suspension type resins, reaction kinetics of polymer
formation vary greatly. In general, dispersion resins are of a high
density with small particle size. The process is initiated by charging
the necessary ingredients (water, liquid, VC, emulsifiers, and a free
3-21
-------
radical initiator) to an evacuated reactor. Proportions of these
ingredients and other minor additives will vary depending on the type of
resin and the resin grade. Emulsifiers (soaps and surfactants) are used
to disperse VC in the water phase. Soap micelles (i.e., colloidal
aggregates that are formed above a critical emulsifier concentration)
also contain small amounts of VC and are the site of polymer formation.
Initiators used are water soluble (versus VC soluble initiators used in
suspension polymerization) and penetrate soap micelles to begin poly-
merization. Commonly used initiators are hydrogen peroxide, organic
peroxides, and peroxydisulfates.
Two general types of resin are produced by the dispersion process -
latex and dispersion. If the latex type resin is to be produced, only a
small amount of VC and initiator are normally charged. The reactor is
heated by injecting steam into the reactor jackets to initiate formation
of free radicals. Agitation is used to disperse the monomer and other
ingredients in the water medium. Once polymerization begins, the heat
of reaction is removed by circulation of cooling water through the
reactor jackets. Small amounts of initiator and monomer are then con-
tinuously added during polymerization until the correct particle size is
attained. Conversion of VC to latex polymer is almost complete. Latex
resin particle sizes range from 0.05 micrometers to 2 micrometers.
The residual VC is removed from latex resins by completely reacting
the free VC with additional catalyst (post-catalysis). This is done in
the reactor or in a separate vessel. The regulation requires that latex
resins be stripped to 400 ppm RVC. Latex resins are usually sold in
solution, and drying or separation of resin from the polymer slurry is
not necessary.
The process for formation of dispersion type resins follows that
described for latex resins except that more monomer is added to allow
particles to grow to a larger size. In some cases the process may call
for "seed" latex. The "seed" latex is formed by starting a batch in a
separate reactor. Before this batch reaches 60 percent conversion it is
transferred to other reactors with more VC and emulsifiers. This allows
formation of larger emulsion particles which are used in plastisol and
stir-in resins. These dispersion type resins range from 0.2 micrometers
3-22
-------
to 5 micrometers in particle size and are more sensitive to heat and
mechanical agitation than suspension resins. Because the dispersion
resins are more sensitive, stripping the resin may take longer because
lower stripping temperatures are used. The regulation requires that
dispersion type resins be stripped to 2,000 ppm RVC.
After polymerization is complete, the dispersion resins are usually
spray dried. Spray-dried resins contain emulsifiers that inhibit the
absorption of plasticizers. In many applications where heat is applied
during fabrication, this property is acceptable because the heat melts
the resins which allows plasticizer absorption. In some fabrication
processes (such as calendering), plasticizers must be absorbed prior to
fabrication because temperatures used are not high enough to melt the
resin. If removal of the soaps from the dispersion resin is desired,
coagulation of emulsifiers with salts is usually performed. The salts
(calcium or magnesium) are added to the polymer slurry and the emulsi-
fiers precipitate and are rinsed out with water. The resin and water
are then separated and the resin is dried in a rotary or pan dryer
(Erdman, 1980).
3.4.6 Bulk Polymerization
Bulk (mass) polymer resins are produced by a two-stage polymerization
process. A simple diagram of the bulk process is shown in Figure 3-4
and requirements of the regulation for bulk plants are summarized in
Table 3-3. The first stage is the formation of a "seed" resin in a
vertical pre-polymerization (Pre-Po) reactor. The "seed" resin is
transferred to a horizontal post-polymerization (Po-Po) reactor in the
second stage of the process. More VC is added to the Po-Po which allows
the "seed" resin to grow in size to the finished resin product. The
bulk process differs from the dispersion process in that no water is
used in the reaction - the process is anhydrous. The bulk process used
in this country is licensed by Rhone-Poulenc of France. A new version
of the Rhone-Poulenc process utilizing a vertical Po-Po reactor is now
available, but is not currently being used in the United States.
The Pre-Po reactor is charged with liquid VC and enough initiator
to carry the reaction to approximately seven to twelve percent conversion.
Initiators used are those commonly used in the suspension process - an
3-23
-------
Recovered VC
CO
i
ro
Pre-Polymer1zat1on
Reactor
"Inprocess
Wastewater
Post-Polymerization
Reactor
Vent to
Control Device
H20 from Double Mechanical
Seals on all Pumps.
Condensed Steam from
Reactor Evacuating
Condensed Steam from
Polymer Stripping
Reflux
Condenser!
Process Steps
Product Storage
and Shipping
VC Unloading and Storage
Mixing. Weighing and Holding
Pre-Polymerlzatlon
Post-Polymerization
Recovery System
Blending and Screening
"In Process" Uastewater Stripping
PVC Storage
I
-------
Table 3-3. POINT SOURCE EMISSIONS TYPICAL OF BULK PVC PLANTS
Process step
Potential emission points
Regulation requirements
CO
i
ro
en
1 VC unloading and storage Loading lines, VC storage tank
Mixing, weighing and
holding tanks before
stripping operation
Pre-polymerization
Post-polymerization
(stripping in reactor)
Mixing, weighing and holding
tank vents
Polymerization reactor opening
loss (ROL)
Polymerization reactor relief
valve discharges
Polymerization reactor rupture
disc discharges
Polymerization reactor opening
loss (ROL)
Emissions from loading lines must be
reduced so that upon opening of line
to the atmosphere emissions do not
exceed 0.0038m"5 of VC at STP.
VC removed from lines to meet this
criteria must be controlled to <_ 10
ppm upon exhaust to the atmosphere.
Concentration of exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
ROL from each reactor is not to exceed
0.02 g VC/kg PVC products.
No discharge to the atmosphere except
for an emergency relief discharge.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm. Not required to be
reported.
ROL from each reactor is not to exceed
0.02 g VC/kg PVC products.
"(continued)
-------
Table 3-3. Concluded
Process step
Potential emission points
Regulation requirements
CO
i
ro
en
Monomer recovery system
Blending (mixing,
weighing and holding
tanks after stripping
operation)
"Inprocess" wastewater
stripper
8 PVC loading and storage
Polymerization reactor relief
valve discharges
Polymerization reactor rupture
disc discharges
Recovery system exhaust
vent knock-out pot
Dry resin blend tanks and
screening operation
baghouse vents
Wastewater storage tank
Wastewater stripper column
Storage silos
No discharge to the atmosphere except
for an emergency relief discharge
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm. Not required to be
reported.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
Not regulated.*
VC removed from in process water is
to be ducted to a control system from
which concentration of VC in exhaust
gas does not exceed 10 ppm.
Not regulated.*
*If a PVC plant is using stripping technology to control VC emissions, emission sources beyond the stripper
are not regulated.
-------
oil soluble, free radical catalyst (Mass, 1977). The Pre-Po reactor is
brought to an operating temperature of 40°C to 70°C (130°F to 184°F) by
injecting steam into the reactor jackets. Strong agitation is used to
form small particles of approximately 1 micrometer (Mass, 1977, p. 75).
These small particles provide the "seed" that grows in size to form
resin beads in the Po-Po reactor. The remaining liquid VC and seed
resin are pumped to the Po-Po reactor at approximately 7 to 12 percent
conversion.
Total cycle time for the Pre-Po is 2 hours (Dubec, 1980) which is
normally one-fifth the duration of the Po-Po cycle. Thus, one Pre-Po
reactor can be used to feed as many as six Po-Po reactors.
After the "seed" polymer and remaining liquid VC is pumped from the
Pre-Po to the Po-Po, more VC and initiator are added to the Po-Po for
completion of the reaction. Small amounts of additional additives may
be charged to the reactor for heat stability and particle size control
(Dubec, 1980). The number of PVC particles in the Po-Po is determined
by the amount of seed resin charged from the Pre-Po. The "seed" resin
absorbs the VC and at about 20 percent conversion the batch becomes
solid and powdery, thus the agitator in the Po-Po must be of rugged
construction. When the conversion to PVC has reached 70 percent to
90 percent, steam is injected and a vacuum is pulled on the reactor to
remove RVC from the resin particles. This represents the bulk stripping
procedure that takes place in the Po-Po reactor. Exhaust gases from
this stripping procedure are vented to recovery and the primary control
so that VC emissions do not exceed 10 ppm. VC recovered from the reactors
is sent back to the charge tank for reuse. The regulation requires bulk
resins to be stripped to 400 ppm RVC as determined on a dry solids
basis.
In producing PVC resins by the bulk process, temperature is the
major control variable for determining the molecular weight of the
polymer. One disadvantage of the bulk process is that there is not a
good medium for heat transfer from the polymer reaction to the reactor
wall. Reflux condensers are used to help control the reactor vessel
temperature. The condensers remove gas from the reactor headspace,
condense the gas, and then return the liquid VC to the reactor. Heat
from the gas is removed by cooling water in the reflux condensers.
3-27
-------
The Po-Po is opened after every batch for cleaning. VC concentrations
that are emitted when the Po-Po reactor is opened may be determined by
actual measurement or by calculation as approved by the Administrator.
Polymer removed from the Po-Po reactor (already dry) is pneumatically
conveyed to screens that remove oversize particles. Batches may be
blended to improve product uniformity.
Bulk resins range in size from 0.1 to 1.0 micrometers and exhibit
excellent qualities for dry-blending compounds. The beads are of uniform
size and porosity which allows uniform absorption of plasticizer. Also,
because suspending agents and surfactants are not used, the finished
resin has a higher purity and therefore better heat stability than
suspension or dispersion resins (Nass, 1977, p. 75).
3.4.7 Solution Polymerization
PVC produced by the solution process typically consists of copolymers
of VC and polyvinyl acetate. Only one company is producing resins by
this process in the United States. A simple diagram of the solution
process is shown in Figure 3-5 and requirements of the regulation are
summarized in Table 3-4.
The solution process is continuous and liquid VC, vinyl acetate,
solvent, and initiator in solution are fed to a polymerization reactor
which operates at low temperatures. Conversion to copolymer is approxi-
mately 60 percent to 70 percent. The copolymer resin solution is removed
continuously and fed to a stripping operation that removes the solvent.
VC and vinyl acetate are soluble in the solvent. The monomers and
solvents are mixed and charged to the reactor separately from the initiator
solution. The copolymer formed is soluble in the solvent and forms a
homogeneous solution. Typical solvents listed in the literature for
this type of process are N-butane; aliphatic alcohols, ketones, esters,
and hydrocarbons; aromatic hydrocarbons; and chlorinated hydrocarbons.
No resin particles are formed by the solution process and RVC is
stripped by distillation. Distillation takes place in a conventional
trayed column. Acetone vapors are used to strip VC from the copolymer
resin solution. The acetone vapors taken overhead from the distillation
column are sent to a VC recovery system and then recycled back to the
process.
3-28
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VC and
[ Co-Monomer]
Storage
VC unloading
CO
ro
Solvent i
Solution
Polymerization
Reactor
Coagulation
aj L _' J
PVC Storage
and Shipment
Solvent to
^
Solvent Recovery
Process Steps
VC Storage and Unloading
Mixing
Solution Polymerization Reactor
VC Recovery
Coagulation
Drying
PVC Storage and Shipment
Figure 3-5. Solution process flow diagram.
-------
Table 3-4. POINT SOURCE EMISSIONS TYPICAL OF SOLUTION PROCESS PVC PLANTS
Process step
Potential emission points
Regulation requirements
VC unloading and storage
Loading lines, VC storage tanks
CO
I
CO
o
Mixing, weighing and
holding tanks before
stripping operation
Solution Polymerization
Reactor
VC recovery (stripping)
Mixing, weighing and holding
tank vents
Polymerization reactor opening
loss (ROL)
Polymerization reactor relief
valve discharges
Polymerization reactor rupture
disc discharges
Recovery condenser vent
Emissions from loading lines must be
reduced so that upon opening of line
to the atmosphere emissions do not
exceed 0.0038mJ of VC at STP.
VC removed from lines to meet this
criteria must be controlled to < 10
ppm upon exhaust to the atmosphere.
Concentration of exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
ROL from each reactor is not to exceed
0.02 g VC/kg PVC products.
No discharge to the atmosphere except
for an emergency relief discharge.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm. Not required to be
reported.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
(continued)
-------
Table 3-4. Concluded
CO
I
CO
Process step Potential emission points Regulation requirements
5 Coagulation Resin solution storage tank Not regulated.
condenser vent, resin
precipitation vent
6 Resin drying Dryer vent Not regulated.
7 PVC storage and loading Silo vents Not regulated.
-------
After stripping, the resin in solution is recovered by precipitation.
A constituent is added to the solution reducing the solution solubility
of the copolymer resin and allowing the copolymer to precipitate.
Copolymer resins are then separated by centrifugation. The resins are
rinsed with water to prevent the particles from sticking together. The
rinsed resins are flash dried and then are penumatically conveyed to
storage silos or packaged for shipment. Solution resins are used by
casting and coating fabricators to provide thin coatings for food and
beverage containers. Solution resins are highly pure because emulsifiers
or suspending agents are not used in the process.
3.4.8 Polymerization Reactors
The design of the reactors used in the various polymerization
processes is important for controlling resin quality. Polymerization
conditions (e.g., temperature, pressure, and agitation) within the
reactor are primary control variables in the production of PVC resins.
These operating conditions along with reactive constituents charged to
the reactor produce the various resin grades.
Reactor emissions are subject to several sections of the current
regulation (see Table 2-1). Requirements of Section 61.64 of the
regulation specify the following emissions limits:
o Concentration of VC in all exhaust gases discharged to the
atmosphere must not exceed 10 ppm except for emergency relief
valve discharges.
o Reactor opening loss (ROL) emissions are not to exceed 0.02 grams
VC per kilogram of PVC product.
Leakage from reactor agitator seals and relief valves are covered under
subsections 61.65(b)(3v) and 61.65(b)(4), respectively, which require
installation of double-mechanical seals on agitator shafts and installation
of rupture discs upstream of relief valves; connecting relief valves to
process lines or recovery system or equivalent as approved by the
Administrator. Equivalency clauses for these equipment requirements are
included under Sections 61.65(b)(3v) and 61.65(b)(4).
Both suspension and dispersion (emulsion) type resins are produced
in a similar reactor under similar conditions and thus will be discussed
together. Bulk (mass) type resins are produced in a two-reactor system.
Solution type resins are the only PVC resins commercially produced by a
3-32
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continuous process in a reactor similar to a distillation column. A
discussion of various reactors follows.
Reactors for Suspension and Dispersion (Emulsion) Type Resins
The following reactor parameters are common to suspension and
dispersion processes:
t Reactor Size and Number - each plant may have from 4 to more
than 50 reactors. Reactors currently being used in the United
States range in size from 11.3 cubic meters to 169.5 cubic
meters (3,000 gallons to 45,000 gallons) (Khan, 1978, p. 17).
The larger reactors with a 23 cubic meter (6,000 gallon)
capacity and larger are relatively new (early 1970's) and are
being used to reduce variability in product quality and increase
production capacity. With larger and fewer reactors, incorporation
of sophisticated controls is less expensive on a cost-per-pound
basis.
• Reactor Construction - reactors are of stainless steel,
glass-lined carbon steel, glass-lined stainless steel or
stainless steel-lined carbon steel construction. Choice of
material is dependent on corrosion resistance required and
desired lifetime of reactors (Khan, 1978, p. 17). In larger
reactors where wall thickness approaches 0.025 meters (1 inch),
a stainless steel-lined carbon steel reactor offers an advantage
for thermal conductivity (Cameron, 1979, p. 45). This is
necessary in order to dissipate heat of reaction from the
larger amounts of polymer slurry. In small reactors, where
heat conduction is not as critical, glass-lined reactors are
used. The glass lining on the smaller reactors helps to
prevent polymer build-up on the reactor wall which will normally
be hotter than the reactor wall on a large reactor.
• Operating Temperature and Pressure - for suspension resins,
temperature of the reactor is usually about 55°C (Khan, 1979,
p. 75) and is maintained as a function of the resin properties
desired. This normally produces reactor pressures of 515 kilo-
pascals to 810 kilopascals (5.1 to 8.0 atmospheres). Dispersion
resins are more sensitive to heat and are processed at lower
temperatures (Lamorte, 1978, p. 23).
3-33
-------
Agitation - mixing blades are usually of either retreat curve
or turbine-type and provide the agitation speed that directly
affects product quality (Cameron, 1979, p. 45). In suspension
polymerization, agitation is often operated at lower speeds
than in dispersion polymerization because intense agitation of
dispersion resins results in poor control of particle size
(Mass, 1977, p. 94). Agitation speed is variable and is
determined by the type of resin particle desired. The use of
baffles in the reactor is also important to produce a better
size distribution of particles. The tubular-finger baffle and
single-blade baffle are used and in some instances their
positioning can be set from outside the reactor. Power require-
ments of the agitator drive motor are usually monitored by an
amperage meter. This monitoring instrument is important
because loss of agitation reduces heat transfer to reactor
walls and a runaway reaction could occur.
Cleaning - in order to produce high quality resins, the internal
surface of the reactor must be kept clean. After several
batches, polymer build-up occurs where liquid polymer slurry
contacts the reactor walls. Polymer build-up is also formed
on areas of the reactor that are not in contact with the
slurry. This formation on surfaces other than the walls is
due mostly to a reaction of VC in the gas phase with oxygen, a
common contaminant in the reactor. Regardless of cause, if
polymer build-up is not removed, small flakes of the polymer
will contaminate the next batch. These flakes do not absorb
compounding ingredients (e.g., plasticizers, stabilizers) and
produce areas known as "fish eyes" in the finished resin
product.
The most common cleaning practice involves opening the
reactor manways to allow plant personnel access to clean the
reactor interior. This may be done manually by scraping the
walls or by fitting a high pressure water cleaning system into
the reactor manway. Prior to opening, the ROL requirement
must be attained. In order to meet this requirement some
3-34
-------
method of reactor evacuation is required. The evacuation
method used to attain the ROL is usually a time-consuming
procedure and results in reduced production capacity. These
procedures will be discussed in detail in Section 4.5. To
reduce these reactor openings for cleaning purposes, high
pressure water jets have been installed within some of the
newer reactor vessels. Also, solvent cleaning systems have
been used by several companies - a solvent solution is passed
through the reactor several times to remove polymer build-up.
Some have found this technique successful while others have
abandoned the approach because of high cost and potential
toxicity of the solvent. The use of a chemical treatment of
the the reactor walls after cleaning has also been successful
in preventing polymer build-up. This chemical, which is
usually proprietary, is applied to the reactor walls prior to
polymerization.
• Relief Valves and Rupture Disks - relief valves and rupture
discs are safety devices on the polymerization reactor vessel.
These devices open directly to the atmosphere under abnormal
high-pressure conditions. If the pressure in the reactor
vessel increases beyond a safe limit, the relief valve or
rupture disc relieves the pressure in the vessel. Without
this safety feature a vessel could rupture. Causes of increased
pressure conditions will be discussed in Section 4.2. Relief
valves used for reactor safety are set at approximately 50 to
100 pounds over normal operating pressure. Conventional
relief valves allow a reactor to depressurize and, if operating
properly, the relief valve will close or reseat again after
pressure is reduced.
Reactors for Bulk Resins
A description of bulk reactors follows:
• Reactor Size and Number - the bulk process uses two types of
reactors for polymerization of VC - the pre-polymerization
(Pre-Po) reactor where the reaction is initiated and the
3-35
-------
post-polymerization (Po-Po) reactor where the reaction is
completed. The Pre-Po reactor usually has a 2,200 gallon
capacity (Dubec, 1980) and cycle time is short (about 2 hours)
in order to supply seed resins to other Po-Po reactor. The
Po-Po capacity is normally 4,400 gallons (Holbrook, 1980).
Reactor Construction - both Pre-Po and Po-Po reactors are of
stainless steel construction with water jackets for cooling.
The Pre-Po reactor vessel stands upright with the agitator
shaft entering at the top. The Po-Po reactor vessel is
horizontal with the agitator shaft entering at one end.
Operating Temperature and Pressure - polymerization temperature
in the reactors is normally between 40°C to 70°C (120°F to
158°F) producing VC vapor pressures in the reactor of between
500 kilopascals to 1,200 kilopascals (5 atmospheres to 12
atmospheres). Temperature control is much more critical in
the bulk process because there is no water to transfer heat to
reactor walls. In addition to reactor jacket cooling water,
reflux condensers are used to remove heat by condensing gaseous
VC from the reactor and returning it as liquid VC.
Agitation - agitation in the Pre-Po is by a flat bladed,
turbine-type agitator and is much stronger than the agitation
used in the Po-Po. This stronger agitation is necessary to
produce small seed particles of the required size distribution
(Goiran, 1980). Baffles are used to prevent formation of a
vortex (whirlpool). Agitation in the Po-Po is by a ribbon
blender which results in less extensive and slower agitation
(Schoultz, 1977, p. 654). The particle size produced is
dependent on the agitation history in the Pre-Po reactor.
Cleaning - polymer build-up in the Pre-Po is slow because
polymerization only reacts to 7 to 12 percent conversion.
Cleaning may only be necessary every 5 to 50 batches depending
on the resin product (Dubec, 1980). The Po-Po is opened for
cleaning after every batch for manual cleaning because the
dry, powdery resin adheres to the reactor walls and agitator
blades (Dubec, 1980).
3-36
-------
t Rupture Disc and Relief Valves - the same as those used on
suspension/dispersion reactors.
Reactors for Solution Resins
Polymerization reactors in the solution process operate on a continuous
cycle as opposed to the batch cycle of reactors used in suspension,
dispersion, and bulk processes. Heating to initiate the solution process
is supplied by hot water that is passed through coils inside the reactor.
The solution process is run at lower temperatures than the other processes
and over-pressure problems are rare (Erdmann, 1980). Heat of reaction
is removed by reflux condensers. Agitation is provided by an external
pump cycle that circulates the reactants through the reactor.
Relief valves and rupture discs are used on the solution reactor
for safety purposes. Rupture discs are set at pressures higher than the
relief valve. Reactor relief valve discharges from an accelerated
reaction are uncommon in the solution process. Most relief valve releases
that occur are due to premature rupture disc failure.
Polymer build-up is not a problem in the solution reactors. When
cleaning is necessary, pure solvent is circulated through the reactors
for cleaning. Reactors are only opened for maintenance and inspection
procedures.
3.4.9 Emissions for a Typical PVC Plant
The study done in support of the current regulation identified 41
existing PVC plants. The VC emissions from these 41 PVC plants totaled
85 gigagrams (187 million pounds) per year in 1974, which represented
approximately 85 percent of the total nationwide emissions of VC.
Emissions data submitted by PVC producers were used to calculate emissions
estimates for seven areas within a typical PVC plant producing 68 gigagrams
(150 million pounds) of PVC resin per year. These four areas of potential
emissions from the typical plant were as follows:
• Reactor and Stripper Losses - this area includes safety relief
valve and reactor opening losses.
• Monomer Recovery System - after recovery of VC from the process,
the unrecoverable VC was discharged to the atmosphere (these
emissions are now controlled with the primary control device).
3-37
-------
• Slurry Blend Tank. Centrifuges, Dryers and Storage Silos -
these four areas are combined into sources after resin stripping.
• Fugitive Emissions Sources.
The total emissions from the typical PVC plant were approximately
2.7 gigagrams (6.0 million pounds) of VC per year.
Emission data were also compiled for VC losses during equipment
purges. These purges represent VC lost when equipment is taken out of
service for maintenance or inspection. This equipment purging contributed
an additional 833 kilograms (1834 pounds) per year.
3-38
-------
3.5 REFERENCES FOR CHAPTER 3
Albright, Lyle F. 1967a. Manufacture of Vinyl Chloride. Chemical
Engineering (a).
Albright, Lyle F. 1967b. Vinyl Chloride Polymerization by Suspension
Process Yields Polyvinyl Chloride Resins. Chemical Engineering (b).
Cameron, J. B. Lundeen, A. J. McCulley, J. H. , Jr. 1979. Trends in
Suspension PVC Manufacture. Hydrocarbon Processing.
Chemical Week. 1976. PVC Rolls Out of Jeopardy into Jubilation.
DeBernardi, James, Plant Manager, Lake Charles, La. Conoco Plant.
Telecon with Matthew Boss, TRW, November 26, 1980.
Dubec, Harold. 1980. Manager of Environmental Compliance. Trip report -
visit to Hooker Chemical Company, Ruco Division. Burlington, N. J.
September 15, 1980.
Erdman, J. F., Environmental Protection Coordinator, Union Carbide
Corporation, Texas City, Texas. Telecon with Matthew Boss, TRW
Environmental Engineering Division. December 14, 1980.
Goiran, L. Polyvinyl Chloride (PVC) Manufacturing Equipment: Permit
Application for Approval of Modification. Letter to David C. Hawkins,
May 4, 1980.
Hatch, Lewis F., and Matar, Sami. 1979. From Hydrocarbons to
Petrochemicals. Hydrocarbon Processing.
Holbrook, W. C., Director of Toxicology and Environmental Affairs.
Trip report - visit to B. F. Goodrich Chemical Company, Pedricktown
Plant. Pedricktown, N. J. September 17, 1980.
Khan, Z. S., and Hughes, T. W. 1978. Source Assessment: Polyvinyl
Chloride. Industrial Pollution Control Division, Industrial Environmental
Research Laboratory. Cincinnati, Ohio.
Lamorte, Michael F. 1978. National Emission Standards for Hazardous
Air Pollutants Inspection Manual for Vinyl Chloride. Research Triangle
Institute.
Little, Arthur D., Inc. Vinyl Chloride Monomer Emissions From the PVC
Processing Industries. Contract No. 68-02-1332, Task No. 10. August
1975.
3-39
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McCulley, J., Process Engineer, Conoco. Telecon with Matthew Boss, TRW.
November 24, 1980. Use of Relief Valves and Rupture Discs at PVC
Facilities.
McPherson, R. W.; Starks, C. M.; Fryar, G. J. 1979. Vinyl Chloride
Monomer . . . What You Should Know. Hydrocarbon Processing.
Milby, Thomas H. 1978. Vinyl Chloride an Information Resource. Stanford
Research Institute. Menlo Park, California.
Mukerji, Asu. 1977. Unloading and Storage Technique for Vinyl Chloride
Monomer. Chemical Engineering.
Nass, Leonard I. 1977. Encyclopedia of PVC. Society of Plastic Engineers,
Inc., Vol. 3. New York. Marcel Dekker, Inc.
Schoultz, Kenneth S. ; Bochinski, Julius H. ; Goeon, James A. 1977.
Engineering Control Assessment of the Plastics and Resins Industry . . .
Case Study: Manufacture of PVC by Bulk Polymerization. American
Industrial Hygiene Association Journal.
Shreve, R. N. ; Brink, Joseph A., Jr. Chemical Process Industries.
McGraw-Hill Book Company. New York, N. Y. 1977.
Sorenson, Wayne R. 1977. A Close Look at PVC Today. Plastics Engineering.
U.S. Environmental Protection Agency. 1975. Standard Support and
Environmental Impact Statement: Emission Standard for Vinyl Chloride.
Emission Standards and Engineering Division. Research Triangle Park,
North Carolina.
3-40
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4.0 CONTROL TECHNIQUES USED TO COMPLY WITH THE
EXISTING EMISSION STANDARD
Tables 4-1 and 4-2 identify control technologies that can be applied
to potential emission points from EDC/VC and PVC plants. Tables 4-3 and
4-4 show the estimated emissions reductions that result when the typical
EDC/VC and PVC plants, developed during the original standard support
study (EPA, 1975), comply with the applicable current standard. Actual
emissions are lower because the majority of plants surveyed have lower
levels than required by the current standard with the possible exception
of relief valve discharges. Primary control devices are reducing
emissions, in most cases, well below the 10 ppm level for exhaust gases.
EDC/VC plants using a pure oxygen (or combination oxygen and air) feed-
stock for the oxychlorination reactor and/or incinerating the oxy vent
have reduced emissions below the standard. Fugitive emissions from new
large reactor plants are 95 percent lower than those emissions from
typical plants in 1975 (Holbrook, 1980a). Most PVC plants are stripping
resins to lower levels than required and new purging methods have been
developed to reduce reactor opening losses.
The following sections discuss the control technologies that industry
is currently using to accomplish the various requirements of the regulation
and to achieve actual emissions reductions. Improvements and new
developments in control technology since promulgation of the regulations
are also discussed.
4.1 DISCHARGE OF EXHAUST GASES TO THE ATMOSPHERE
4.1.1 Introduction
The current regulations require that the discharge of exhaust gases
to the atmosphere be controlled to meet a set standard. The sources of
these exhaust gases, the applicable standards, and control technologies
-------
Table 4-1. POINT SOURCE EMISSIONS AND TECHNOLOGIES FOR CONTROL IN TYPICAL SUSPENSION,
DISPERSION AND BULK PVC PLANT
Process step
Potential emission points
Regulation requirements
Control technology
1 VC unloading and storage Loading lines, VC storage tank
i
ro
Mixing, weighing and
holding tanks before
stripping operation
Polymerization
Stripping
Monomer recovery system
(Blending, Mixing.
weighing and holding
after stripping
operation)
Mixing, weighing and holding
tank vents
Polymerization reactor opening
loss (ROL)
Polymerization reactor relief
valve discharges
Stripping vessel vent
Recovery system exhaust
vents and knock-out pot
Slurry blend tanks and holding
tank vents
Emissions from loading lines must be
reduced so that upon opening of line
to the atmosphere emissions do not
exceed 0.0038mJ of VC at STP.
VC removed from lines to meet this
criteria must be controlled to <
10 ppm upon exhaust to the atmosphere.
Concentration of exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
Concentration of VC exhaust gases
discharged to the atmosphere must
not exceed 10 ppm.
ROL from each reactor Is not to exceed
0.02 g VC/kg PVC products.
No discharge to the atmosphere except
for an emergency relief discharge.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
Concentration of VC exhaust gases
discharged to the atmosphere must not
exceed 10 ppm.
Controlled by stripping standards
Purged to monomer recovery system
Incineration, solvent absorption or
carbon adsorption
Vented to monomer recovery system
followed by Incineration, solvent
absorption, carbon adsorption, or
combinations of these
Solvent cleaning, steam piston.
water piston, reactor purge air
blower, steam purge, etc., used
before opening
Vented to atmosphere or monomer
recovery system
Shortstop, containment, instrumentation,
Improved operator training, etc.
Vented to monomer recovery systen
followed by Incineration, solvent
absorption or carbon adsorption
Gasholders used In some Instances to
collect all recovery vents and/or
refrigeration to condense VC followed
by Incineration, solvent absorption
or carbon adsorption
Stripping technology
(contlnuoH)
-------
Table 4-1. Concluded.
Process step
Potential emission points
Regulation r
Control technology
Drying, sizing, screening
of dewatered resin
Centrifuge vents, dryer vent
stacks, storage silos, bag-
house vents, screening
operation vents
PVC loading and storage Storage silos
"Inprocess" wastcwater
stripper
10 All of the above process
steps
Wastewater storage tank
Uastewater stripper column
Fugitive emissions sources
Controlled by stripping standards.
Controlled by stripping standards.
VC removed from In process water Is
to be ducted to a control system from
which concentration of VC In exhaust
gas does not exceed 10 ppm.
Equipment specifications, operational
procedures and leak detection and
elimination programs.
Stripping technology
Stripping technology
VC removed from wastewater by steam
stripping in column or batch vessel,
vented to monomer recovery system followed
by Incineration, solvent absorption or
carbon adsorption
Double mechanical seals, double outboard
seals, rupture discs or equivalent
equipment; closed systems and equipment
purging to monomer recovery system; area
monitors, portable monitors, routine leak
surveys and maintenance programs
I
CO
VC collected from equipment seals and
operational procedures are to be
controlled to £_ 10 ppm upon exhaust
to atmosphere.
Vented to monomer recovery systta followed
by Incineration, solvent absorption or
carbon adsorption
-------
Table 4-2. POINT SOURCE EMISSIONS AND TECHNOLOGIES FOR CONTROL IN
"BALANCED PROCESS" EDC/VC PLANTS
Process step
Potential emission points
Regulation requirements
Control technology
1 Direct chlorination
2 EDC purification
3 "Inprocess" wastewater
stripper
4 Oxychlorlnatlon
5 VC cracking and
purification
6 VC loading and storage
All of the above process
steps
Product condenser
EDC crude storage, light ends
column condenser, light ends
storage tank, heavy ends
column condenser, heavy ends
storage tank
Wastewater storage tank
Uastewater stripper column
Water wash column
Oxychlorinatlon process vent
Separator tank
EDC quench column
HC1 column vent
VCH column condenser
Loading lines
VC storage tanks
Fugitive emissions
Not regulated.
All emission points are required
to be controlled to <_ 10 ppm.
VC removed from Inprocess water 1s
to be ducted to a control system from
which concentration of VC in exhaust
gas does not exceed 10 ppm.
Emissions from reactor are not to
exceed 0.2 g VC/kg of the 100 percent
EDC product.
Concentration in all exhaust gases
must not exceed 10 ppm.
Emissions from loading lines (and any
other equipment In VC service) must
be reduced so that upon opening of
line to the atmosphere emissions do
not exceed 0.0038mJ of VC at STP.
VC removed from lines to meet this
criteria must be controlled to <
10 ppm upon exhaust to the atmosphere.
Concentration of exhaust gases
discharged to the atmosphere from
storage tanks must not exceed 10 ppm.
Equipment specifications, operational
procedures and leak detection and
elimination programs.
VC collected from equipment seals and
operational procedures controlled to
10 ppm upon exhaust to the atmosphere.
Not regulated
Incineration
Wastewater steam stripped in column or
batch vessel, VC can be recovered by
refrigeration and exhaust gases
Incinerated
Process modifications; incineration;
pure oxygen feed and Incineration
Incineration
Closed systems, carbon adsorption and
purge to monomer recovery system
Incineration
Double Mechanical seals, double outboard
seals, rupture discs or equivalent; purge
to monomer recovery system; and area
monitors, portable monitors, routine
leak surveys and maintenance programs
Incineration
-------
Table 4-3. EMISSION REDUCTION FOR 316 Gg/yr EDC/VC FACILITY IN
COMPLIANCE WITH CURRENT REGULATION
Emission
source
Relief valve
discharges
Primary control
Oxychlori nation
vent
Fugitive
emissions
Total
Current
standard
Non-preventable
discharges only
10 ppm
0.02 kg/ 100 kg
EDC product
Work practice and
equipment standard
emissions
Uncontrolled3
emissions
(kg/yr)
Unknown
916,400
113,760
379,200
1,409,360
Regulated
emissions
(kg/yr)
Non-preventable
discharge
3,160
50,150e
37.9209
91,230
+ non-preventable
discharges
Estimated
actual
emissions
(kg/yr)
1,950C
3,160d
25,000f
10,000h
40,110
Based on EPA emissions estimates developed from emissions data submitted by industrial sources.
Represents emissions from EDC/VC meeting current standard; actual emissions are lower.
c Based on relief valve discharge data from Table 4-7 and EDC/VC production data for 1977-1980 (Chemical
and Engineering News, 1980a). Production for the 9 EDC/VC plants was estimated to be 6,325 million
kg for the 4-year period. An emission factor of 6.2 kg VC per million kg produced was used.
Due to the relatively small amount of emissions involved, a new estimate of emissions was not made in
this study. Data on hand indicate that emissions may be lower than those shown.
e Assumes balanced process and 100 percent conversion during EDC cracking.
Estimate represents an average of emission levels ranging from plants using only air and not incinerating
the oxy vent (and still meeting the standard) to those using oxygen and incinerating. This estimate is
based on very limited data (DeBernardi, 1981).
9 Assumes 90 percent reduction following installation of required equipment and implementation of leak
detection and elimination programs.
Based on results of a fugitive emission study done in an EDC/VC plant (Blacksmith, et al., 1980).
4-5
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Table 4-4. EMISSIONS REDUCTION FOR 68 Gg/yr PVC FACILITY IN
COMPLIANCE WITH CURRENT REGULATION
Emission
source
Primary control
Relief valve
discharges
Combined sources
after resin
stripping
Fugitive
emissions
Reactor opening
loss
Total
Current
standard
10 ppm
Non-preventable
discharges only
400 ppm - suspension,
latex, and bulk
[2000 ppm - dispersion]
Work practice and
equipment standard
0.002 kg/100 kg
PVC product
emissions
Uncontrolled*
emissions
(kg/yr)
326,400
136,000
850,000
1,040,400
312,800
2,665,600
Regulated
emissions
(kg/yr)
680
Non-preventable
discharges
27,200
[136,000]
108,800
1,360
138,040
[246,840]
+ non-preventable
discharges
Estimated
actual
emissions
(kg/yr)
680C
4,780d
13,600s
[74,800]
25,500f
1.3609
45,920
[107,120]
Based on EPA emissions estimates developed from emissions data submitted by industrial sources.
Represents emissions from PVC plant meeting current standard; actual emissions are lower except for
relief valve discharges.
c Because of the relatively small amount of emissions involved, a new estimate of emissions was not
made in this study. Emissions may be lower than those shown here because plants are presently
controlled lower than 10 ppm.
d Based on relief valve discharge data from Table 4-6 and total PVC production for 1977-1980 (Chemical
and Engineering News, 1978; ibid. 1980b). Emission value includes 580 kg/yr for nonreactor relief
valve discharges and 4,200 kg/yr for reactor relief valve discharges. Production for the 23 PVC
plants was estimated to be 5800 million kg for the 4-year period. An emission factor of 70.2 kg VC
per million kg PVC product was used.
e Based on an average of stripping levels reported by industrial sources.
f Estimation quoted from SPI, based on B.F. Goodrich fugitive emission study (delaCruz, 1981).
9 Because of the relatively small amount of emissions Involved, a new estimate of emissions was not
made. Emissions may be lower than those shown.
4-6
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are presented in Tables 4-1 and 4-2. (See Figure 3-1 and 3-2 in
Section 3.0 (Process Description) for locations of process steps). A
complete copy of the regulation can be found in Appendix A.
The most common primary control technologies currently used for
exhaust gases from EDC/VC plants and PVC plants are incineration, solvent
absorption, and carbon adsorption.
Because only emission levels greater than 10 ppm are currently
reported, there is no way to know how effectively exhaust gas controls
are working. In fact, levels may be much less than 10 ppm most of the
time. Results of the initial compliance tests required for primary
control devices following the 2 year waiver period give an indication of
the effectiveness of these devices. However, only one initial source
test was required and, in most cases, the control device was operating
at peak performance. The effectiveness of the control devices over long
periods of time and under variable plant conditions is not known.
The current standard allows no excess emissions during periods
of control equipment shutdown and for this reason most plants maintain
back-up control equipment to provide emission control when primary
exhaust gas control equipment is not operating. Some of these secondary
devices are duplicates of the primary systems (e.g., parallel
incinerators) that are capable of handling 100 percent of plant exhaust
gas discharge emissions, enabling the plant to maintain full production
status. Other back-up systems are potential primary control devices
(e.g., incinerator back-up for a solvent absorption system). Some
plants use temporary measures for back-up control such as short term
storage vessels while others merely maintain an inventory of spare parts
for the single primary control device. There are several plants that do
not have any back-up control systems.
In the original standard support document, several technologies
were identified for possible control of VC emissions in exhaust vents.
These control technologies are being used by the industry and are
discussed in the following sections.
4.1.2 Incineration
In the plants surveyed during this review study, incineration
represented the most prevalent method of exhaust gas emission control.
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In those plants not using incineration as primary control, it is usually
used as a back-up for the primary control system. Many of the plants
maintain two incinerators so that control is provided if one is out of
service.
Waste streams containing chlorinated hydrocarbons such as VC are
more difficult to combust and higher temperatures of combustion are
usually required in comparison with non-chlorinated hydrocarbon waste
streams. Combustion temperatures of 980° to 1,100°C (1,800° to 3,000°F)
have been recommended for efficient destruction of halogen-containing
hydrocarbons by thermal oxidation. However, many of the VC sources
surveyed that use thermal oxidation are operating their incinerators at
much lower combustion temperatures.
A disadvantage to incineration is that it is a destructive
control method. No VC is recovered and in those cases when waste heat
has been recovered, no return has been shown.
The methods of incineration used in the VC industry are thermal and
catalytic. The incineration method used most often is thermal oxidation.
Incineration temperatures for VC emission control range from 760°C to
1,290°C (1,400°F to 2,350°F) with residence times of 0.5 seconds to
2.0 seconds. One company has recently tested a back-up incinerator at a
combustion temperature of 540°C (1,000°F). Results showed average VC
concentrations of 0.26 ppm. The following data show the results of
their tests with a range of incineration temperatures. These tests were
performed to determine compliance and were observed by a Region IV
representative as well as members of the Kentucky Division of Air
Pollution Control. At the time of the tests, the plant (an EDC/VC
facility) was operating under conditions stipulated by EPA compliance
test parameters, i.e., at least 90 percent capacity (Holbrook, 1980b).
Combustion Average VC
temperature concentration
540°C (1,000°F) 0.26 ppm
650°C (1,200°F) None detected
870°C (1,600°F) None detected
980°C (1,800°F) 0.18 ppm
4-8
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One of the major VC and PVC producers has extensively studied
incineration technology and they report that the large size and high
temperatures (used in conventional thermal incineration) are not always
necessary for efficient combustion of VC. This manufacturer uses a
smaller (Brule) incinerator as a back-up control in its PVC plants. The
incinerator and stack are lined with a ceramic material that allows the
unit to reach optimum temperature within a few hours. A large surge
tank contains the exhaust gases until the incinerator comes up to
temperature and regulates the flow to the unit. The incinerator is
heated to 704° to 760°C (1,300° to 1,400°F) using supplemental fuel. At
this point the vinyl chloride waste stream is fed to the incinerator
which raises the energy content of the stream, thus causing a reduction
of the supplemental fuel feed. A temperature of 870° to 980°C (1,600°
to 1,800°F) is maintained which burns the exhaust gases to less than
10 ppm VC (Varner, 1980).
Auxiliary fuel usage in thermal oxidation systems varies according
to processes. One EDC/VC plant adds methane during direct chlorination.
This both enhances the combustion of vinyl chloride as well as provides
a "fuel-rich" mixture in the reactor to avoid explosion. Some EDC/VC
plants use pure oxygen instead of air as feedstock for the oxychlorination
reactor. As mentioned in Section 3.1.2, this minimizes the venting of
inerts, provides more efficient incineration, and greatly reduces auxiliary
fuel usage. These plants view the reduced energy consumption as an
economic advantage. The use of pure oxygen would seem to be a measure
to attain compliance with other hydrocarbon standards (such as volatile
organic compounds (VOC)) (Brittain, 1980a).
There are several approaches to the control of the EDC oxychlorination
reactor vent (oxy vent). Some EDC/VC plants do not incinerate the
oxychlorination vent gas but, instead, meet the standard by process
modifications (e.g., incorporation of vapor phase catalytic reaction)
(DeBernardi, 1980). There may be high concentrations of VC emissions
during start-up, shutdown and unstable operating conditions. Some
plants incinerate the oxy vent during these periods (Brittain, 1980b).
Oxy vent emissions are potential candidates for regulation (for VOC) by
State Implementation Plans (SIP) and New Source Performance Standards
(NSPS) programs.
4-9
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Incinerators are equipped with flame arresters or flash-back
preventative devices necessitated by the hydrocarbon-oxygen content of
the waste streams. Because combustion of halogen-containing hydrocarbons
results in the formation of HC1, quench systems for cooling and caustic
scrubbers for HC1 removal are incorporated when required by state
regulations.
Continuous monitoring of incineration stacks and compliance tests
have shown VC levels ranging from "non-detectable at 0.1 ppm" to "less
than 10 ppm" according to regional enforcement personnel.
The following problems have been identified with thermal incineration
systems.
• Incinerator overloading. When VC levels are too high the rich
mixture of combustibles leads to elevated temperatures and
results in maintenance problems. Some plants have solved this
problem by using a surge vessel (such as a gasholder) to
provide a constant feed to the incinerator.
• The thermal incineration process can be a source of secondary
air and water pollution (e.g., HC1 and CK generation from
combustion and high total dissolved solids (TDS) levels from
scrubbing).
• Supplemental fuel and high maintenance requirements represent
additional expenses. One of the major maintenance
items - "downcomers" (connections between furnace and quench
system) - has been estimated to cost $6,000 to replace when
corroded, and replacement may be necessary as often as once
each month. Overall annual maintenance costs for incineration
have been reported around $100,000 (for PVC plant incinerators
designed to handle over 45 kilograms per hour VC). A PVC plant
(with a production rate of 68 gigagrams of PVC resins
per year) uses 26.5 cubic meters (7,000 gallons) of No. 2
fuel oil per month to keep their dual incincerators hot
(Dubec, 1980).
• Monitoring is difficult due to temperature fluctuations and
moisture condensation. Some plants have solved this problem
4-10
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by using a system that removes moisture prior to analysis
(Laundrie, 1980).
• Location of the incinerator requires "safe radius" considerations.
Catalytic incineration systems are currently used by at least one
plant for primary control, and at least one other plant is experimenting
with them. Energy requirements for catalytic oxidation are approximately
one-third of that used for thermal oxidation without heat recovery. The
plant using catalytic incineration passes the exhaust gas vapors through
a wash oil scrubbing system. This hydrocarbon oil contacts the stream
in the vent condenser line countercurrently, recovers vinyl chloride,
and provides a stable load to the incinerator. This is an experimental
procedure serving more of a VC recovery function than an emission control
purpose.
Problems with catalytic incineration include:
• Surge capacity. Assuring even flow into the incinerator
has presented a problem for some plants.
• Catalyst pollution. Organic halides pollute and degrade the
catalyst which is expensive to replace.
e Conversion to other chlorinated hydrocarbons.
• Efficiency. These units reportedly remove less than 60 percent
of the VC in the oxychlorination process.
Waste heat boilers can be used in conjunction with incinerators;
they are used for steam generation for heat recovery.
4.1.3 Steam Boilers
None of the plants surveyed use steam boilers as primary control.
When used, they are maintained for back-up control. The long term
reliability of these units is limited by the corrosivity of the vinyl
chloride stream. One plant is considering the use of "expendable"
boilers as a back-up for this reason.
4.1.4 Flares
The use of flares is generally restricted to back-up control.
Generally speaking, a flare would be installed to accommodate streams
from a large chemical complex in order to reduce hydrocarbon emissions.
One plant uses a flare as an equivalency to the use of a rupture disc
4-11
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upstream from the safety valve. (This represented an approval on the
basis of an equipment standard as opposed to an emission standard.) In
this case the relief valve would discharge directly to the flare.
Parameters for usage were specified (Brittain, 1980a). Regional EPA
personnel discourage the use of flares because they cannot be tested or
monitored reliably. There are other objections to the use of flares.
• A destruction efficiency of 90 percent can be calculated and
therefore it is Agency policy to allow their use only on
exhaust gas streams containing 100 ppm VC or less (Ullrich,
1981).
t There is a need for a large capacity, low pressure vapor/
liquid separator.
• The safe radius restriction can be prohibitive for flare
location. For example, this radius would be 170 meters
(560 feet) for a 17,000 kilojoule per square meter (1,500 Btu
per square foot) per hour radiation density at ground level
(Finch, 1980).
• Secondary pollutants (e.g., noise, hydrogen chloride, smoke)
are produced by the flaring process, thus elevation or
isolation of the flare is required.
• Capital costs. Installed capital costs for elevated flares
range between $40,000 and $700,000; ground flares cost between
$30,000 and $900,000.
• Energy use consideration. For general consideration, the
quantity of steam required can be assumed to be 0.4 kilogram
steam per kilogram of hydrocarbon (0.4 pounds of steam per
pound of hydrocarbon) (Neveril, 1978, p. 5-76). Also, the
dilute gas streams present in both EDC/VC and PVC plants
cannot burn without the addition of natural gas or other fuel.
All the heat produced is wasted.
One company has two flares - one servicing the large chemical
complex and the other installed specifically for PVC process emissions.
The latter was originally designed for emergency releases. The stack is
99 meters (325 feet) tall, thus overcoming the "safe radiation distance"
4-12
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problem. Two vessels (one dry knock-out (KO) drum and one water-sealed
drum) provide enough knock-out volume capacity to keep the liquid from
the top of the stack. The flare has never been used for that "worst-
case" condition but it does handle periodic small relief valve discharges
(non-routine emergencies). Ninety-eight percent of the rupture
disc/relief valve combinations are tied into the flare at that facility.
One disadvantage of the use of a flare for VC emissions is the smoke
inherent in burning the emissions. Even with a discharge of 15 to
20 seconds duration, the smoke emanating from the flare lasts for 1 to
2 hours, creating problems with state opacity regulation (Kachtick,
1980).
4.1.5 Carbon Adsorption
This method is used as primary control in only a few of the plants
surveyed. More often it is used in conjunction with other control
devices (usually incineration). Most of the regional EPA personnel and
industrial representatives felt that carbon adsorption alone is not
effective in reducing discharge emissions to below 10 ppm.
PVC plants are successfully using carbon adsorption systems as
primary control. (It is possible that the competition from hydrocarbons,
other than VC, found in exhaust streams at EDC/VC plants prevent the use
of carbon adsorption systems.) The most practical application of carbon
adsorption control technology would be in PVC plant monomer recovery
systems, closed slurry blend tanks, and storage areas because of the
high VC concentration and low volume streams found in these areas. One
EDC/VC plant uses a very small carbon adsorption system - two 0.4 cubic
meter (110 gallon) carbon-filled vessels run in series - at their marine
loading dock. This is a portable system which is regenerated by passing
hot nitrogen through the carbon beds and into the incinerator
(DeBernardi, 1980).
Two PVC plants using carbon adsorption as primary control for
exhaust gases use a double bed system. When a probe at the outlet of
the bed indicates an approaching 5 ppm level (as an indicator of break-
through), the waste stream is diverted to the other bed while the first
bed is being regenerated. Continuous monitors on these units show the
systems to be effective in reducing VC emission levels to below 10 ppm
4-13
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(Battye, 1978). Back-up control for one plant is a boiler. With the VC
levels from carbon adsorption below 10 ppm, the boiler can also
accommodate effluent from the adsorber without HC1 corrosion problems.
The following disadvantages have been cited for carbon adsorption
systems.
• Regeneration of the beds requires high energy usage.
• Treatment of regenerating gas streams requires another control
device (e.g., incineration).
• Polymerization of VC on the carbon beds is a potential problem.
t With new regulations on hazardous waste treatment and disposal
(RCRA), eventual disposition of the contaminated carbon could
be a problem.
t Carbon adsorption represents higher capital costs than solvent
absorption and incineration.
4.1.6 Solvent Absorption
Four of the plants surveyed use solvent absorption as primary
control for exhaust gases. (All of these are PVC plants although the
principles of solvent absorption can apply to exhaust gas control in
EDC/VC plants.)
The vent gas absorber system used by the major producers incorporates
the same figure-eight solvent absorption technology described in the
original standard support document, with proprietary modifications to
improve efficiency. The function of the vent gas absorber is to strip
and recover residual VC. The recovered VC is then reused in polymerization.
The vent gas absorber system consists of two packed columns. In
the first column the VC gas is absorbed by the lean solvent which enters
at the top. The non-absorbables and a small quantity of solvent are
then vented to the atmosphere from the top of the column.
The VC-rich solvent is passed through a heat exchanger on its way
to the stripping column. In the stripping column the solvent is heated
to remove the VC that comes off at the top and is returned to the process.
The lean solvent comes off at the bottom of the column. The warm, lean
solvent passes back through the heat exchanger and another cooler before
returning to the stripping column for another cycle. The vent gas
4-14
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absorber system described above was developed by B. F. Goodrich who
plans to license the technology; it is commercially available. The only
other solvent absorption system used by the plants surveyed in this
study is a proprietary system designed by the company using it.
The efficiency claimed by the plants using the vent gas absorber
system is 99.99 percent. Capital investment is slightly more than for
incineration but less than for carbon adsorption. Utility costs for the
solvent absorption system are greater than for incineration but less
than those for carbon adsorption; however, VC recovery, achieved in the
vent gas absorber system, results in a substantial credit to the system.
B. F. Goodrich regards the safety advantages of their vent gas
absorber system as significant. The VC from the feed stream is absorbed
in cold solvent and the non-absorbables (containing oxygen) and a small
quantity of solvent are vented to the atmosphere at the top of the
absorbing column. In this operation the cold solvent acts as a built-in
heat sink. As the VC is absorbed by the solvent, it is removed from the
absorber and further contact with any oxygen in the feed stream. Even
though a small volume of gas passes through the explosive range, the
cold solvent heat sink makes the operation safe.
Because there is no flame associated with the operation of a vent
gas absorber (as with incineration) it can be located close to other
parts of the PVC process. In addition, B. F. Goodrich claims that the
unit has a low environmental pollution potential even though some small
amount of solvent is released to the atmosphere. The solvent is
proprietary, commercially available, inexpensive, and reputed to be low
in toxicity.
4.1.7 Refrigeration
This method of controlling exhaust gases is used only in conjunction
with other control devices to reduce the load on these downstream systems.
Condensation of VC and water reduces the volume of gases to be handled
by primary control systems. Use of refrigeration is usually limited to
monomer-recovery systems and in some cases, installation of refrigeration
units was in response to hydrocarbon control for SIP compliance.
4-15
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A typical application of this control technology in a recovery
system can be illustrated as follows: Vents from compressor relief
valves, pumps, transfer lines, weigh scales, condensers and knockout
pots, and slurry and wastewater strippers would go to a common holding
vessel. VC from this vessel would be recovered through compressing and
condensing the monomer in a refrigeration unit. The noncondensable
stream from the recovery system would be vented to a surge tank or
gasholder which would vent to the incinerator (Laundrie, 1980).
The above description represents a monomer-recovery system for a
plant utilizing 18 reactors with an average capacity of 19 cubic meters
(5,000 gallons). Equipment includes seven 0.2 cubic meters per second
(400 cfm) vacuum pumps, two compressors (one 0.2 cubic meters per second
(400 cfm) and one 0.1 cubic meters per second (200 cfm)) and two
0.01 cubic meters per second (30 cfm) vent compressors.
4.1.8 Other Controls
One EDC/VC plant in Region VI uses a separate fixed-bed oxychlorination
reactor to receive only the oxy vent exhaust stream. The reactor converts
VC to heavier chlorinated hydrocarbons which are used in other processes
(Brittain, 1980a).
In the past several years a number of procedures have been proposed
for the removal of vinyl chloride from gas streams. Some of these
systems that have been developed, but are not in current use by the
plants surveyed in this study, follow (Sittig, 1977).
Reaction with ozone. The disadvantage of this method is that it is
slow and requires long residence times to reduce the VC content of the
gas stream to 1 ppm or less. In addition, it is difficult to meter
ozone into the gas streams in amounts that will destroy substantially
all of the VC without leaving an appreciable amount of ozone in the
effluent gas. There are also environmental problems arising from the
presence in the effluent gas of ozonides formed by the reaction of vinyl
chloride with ozone.
Reaction with ozone in the presence of activated carbon. This
process (patent assigned to Tenneco Chemicals, Inc.) is one in which VC
is removed from gas streams that contain from 10 ppm to 1,000 ppm of VC
by contacting the gas stream with ozone in the presence of activated
4-16
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carbon. The gas streams treated in this way contain less than approximately
1 ppm of vinyl chloride and no detectable amount of ozone or ozonides.
Another process (patent assigned to Stauffer Chemical Company) is also
one in which the stream contacts ozone but without activated carbon.
The process can be used to treat gas streams that arise in the ethylene
oxychlorination processes, ethylene dichloride cracking operations, VC
polymerization processes in which VC is a monomer or comonomer, ventilation
streams from areas in which VC is or may be present, processes for
preparing vinylidene chloride, and polymerization processes in which
vinylidene chloride is utilized as a monomer or comonomer.
After reaction with ozone, the gas stream contains hydrogen chloride,
oxygenated compounds such as carbon dioxide and water, and can contain
phosgene and partially oxygenated hydrocarbons such as methanol.
Contacting the treated gas stream with an aqueous medium is
advantageous because products of the reaction are removed from the gas
stream and partially oxidized hydrocarbons can further react with any
unreacted ozone present in the gas stream. The aqueous medium also aids
in hydrolysis of reaction products of ozone and the chlorinated hydrocarbons
present.
4.2 RELIEF VALVE DISCHARGES
4.2.1 Introduction
Pressure vessels, transfer lines, and other equipment in EDC/VC and
PVC plants are equipped with safety relief valves, rupture discs or a
combination rupture disc/relief valve assembly to prevent overpressurization
which might cause a rupture to occur. The size of polymerization reactors,
which can range from several thousand liters for the older reactors to
the new reactors of up to approximately 190,000 liters (50,000 gallons)
used by Huls of Germany (the largest reactors currently being used in
the United States range from 35,000 to 40,000 gallons) plus the close
proximity of the reactors to each other, represents the greatest potential
for an explosion hazard. It is for this reason that existing safety
regulations and insurance companies require and strictly enforce the use
of safety relief devices on pressurized equipment.
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Relief valve discharges, which cause short-term peak emissions,
represented approximately 4 percent of total emissions from a typical
PVC plant prior to promulgation of the regulation (EPA, 1975, p. 5-6).
Relief valve discharge emissions were not quantified for a typical
EDC/VC plant. The major concern during the original standard support
study was for relief valves located on PVC reactors because these relief
valves represented a large source of emissions. PVC plants prevented
reactor relief valve discharges by equipping reactors with instruments
to warn personnel of an emergency condition. Preventive measures could
then be taken such as injecting a short-stop agent to kill the reaction
or manually relieving pressure to the recovery system. One plant used a
gasholder to prevent relief valve discharges and EPA indicated that a
gasholder could be sized to hold all the VC present in an entire reactor
batch (EPA, 1975, p. 4-30).
Based on this information, relief valve emissions were addressed in
Section 61.65(a) which states,
Except for an emergency relief valve discharge, there is
to be no discharge to the atmosphere from any relief
valve on any equipment in vinyl chloride service. An
emergency relief discharge means a discharge [that] could
not have been avoided by taking measures to prevent the
discharge.
When a relief valve discharge occurs, the plant is required to notify
EPA and submit such data as the source (specific piece of equipment),
cause, quantity, and measures that would be taken to prevent future
discharges.
4.2.2 Emissions from Safety Relief Valves
The intention of Section 61.65(a) was to reduce relief valve
discharges through the proper combination of control equipment and
operating procedures. If a release then occurred, it would be considered
either an emergency condition or one in which a plant had not implemented
the proper combination of control techniques.
EPA Regional enforcement personnel indicate that releases are
continuing to occur. As mentioned, the concern during the original
standard support study was for relief valve discharges from PVC reactors
4-18
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that have the potential to discharge the entire reactor contents. Prior
to the regulation, relief valve discharges were not accurately measured
but typically 2,200 kg (5,000 Ib) of VC was released in a 5 to 10 minute
period (EPA 1975, p. 4-30). With the change to larger reactor systems,
the potential quantity of emissions from the relief valve is increased.
Relief valve discharge data from EPA Regional Offices substantiate
the fact that releases are continuing to occur and reactors account for
the largest quantities per release. Table 4-5 shows a compilation of
reactor and non-reactor relief valve discharge data for 32 regulated
sources (55 percent of all sources) for the period 1977 to 1980
(Brittain, 1980; Diem, 1980; Aronson, 1980; West, 1981). These 32
plants were responsible for 533 relief valve discharge events totalling
approximately 450,000 kilograms (1 million pounds) of VC emissions over
the 4 year period.
PVC plants experience both reactor and non-reactor relief valve
discharges. Table 4-6 shows that portion of the relief valve discharge
data in Table 4-5 contributed from PVC plants, which is approximately
82 percent of the total events and 91 percent of the quantity of VC
emitted. Based on these data, an average reactor relief valve discharge
accounted for approximately 1,025 kilograms (2,275 pounds) of VC being
released to the atmosphere. The time period for a reactor relief valve
discharge event ranged from less than 1 minute to 115 minutes, with
typical events less than 10 minutes in duration. The average PVC
non-reactor relief valve discharge was approximately 540 kilograms
(1,200 pounds) of VC emissions over a period of 10 minutes or less.
EDC/VC plants experience non-reactor related relief valve discharges.
Table 4-7 shows that a portion of the relief valve discharge data in
Table 4-5 was contributed from EDC/VC plants. Based on these data, the
average non-reactor relief valve discharge from EDC/VC plants was approxi-
mately 430 kilograms (950 pounds) of VC emissions. The duration of the
EDC/VC non-reactor relief valve discharges was not determined. Together,
the EDC/VC and PVC non-reactor relief valve discharges represented
34 percent of the total events and 20 percent of the total quantity of
VC emitted by relief valve discharge.
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Table 4-5. TOTAL NUMBER OF RELIEF VALVE DISCHARGES AND QUANTITY
OF VC EMITTED FROM 32 REGULATED SOURCES3 FOR THE PERIOD
1977 to 1980
Reactor and non-reactor relief
valve discharges
1977b
1978b
1979
1980C
TOTALS
Events
149
130
156
97
533
kg VC
90,804
126,835
153,212
75,718
446,569
(Ib VC)
(201,787)
(281,856)
(340,472)
(168,260)
(992,375)
The 32 regulated sources are 9 EDC/VC plants and 23 PVC plants.
Relief valve discharge data for 1977 does not reflect data from 1 EDC/VC
plant and 5 PVC plants; these same plants reported data for only 3 months
of 1978.
Relief valve discharge data for 1980 ranges from 8 to 12 months.
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Table 4-6. RELIEF VALVE DISCHARGES FROM PVC PLANTS FOR
THE PERIOD 1977 to 1980
1977
1978b
1979
1980°
PVC
plants9
18
23
23
23
TOTALS
Non- reactor
Events
9
6
50
26
91
relief valve
kg vc
17,550
1,742
11,912
17,998
49,202
discharges
(Ib VC)
(38,999)
(3,869)
(26,471)
(39,996)
(109,335)
Reactor
Events
118
102
77
53
350
relief valve
kg vc
65,028
111,375
129,689
52,174
358,266
discharges
(Ib VC)
(144,507)
(247,500)
(288,199)
(115,941)
(796,147)
aThe 23 PVC plants represent 58 percent of the total number of PVC plants in the U.S.; 2 of these PVC plants
reported no relief valve discharges for the 4 year period.
bRelief valve discharge data from 5 plants is for 3 months of 1978.
GRelief valve discharge data for 1980 ranges from 8 to 12 months.
-------
Table 4-7. RELIEF VALVE DISCHARGES FROM EDC/VC PLANTS FOR THE
PERIOD 1977 to 1980
1977
1978b
1979
1980C
EDC/VCa
plants
8
9
9
9
TOTALS
Non- reactor
Events
22
22
29
18
91
relief valve
kg VC
8,226
13,719
11,611
5,545
39,101
discharges
(Ib VC)
(18,281)
(30,487)
(25,802)
(12.323)
(86,893)
*The 9 EDC/VC plants represent 50 percent of the total number of EDC/VC
plants in the U.S.
DRelief valve discharge data from 1 plant is for 3 months of 1978.
:Relief valve discharge data for 1980 ranges from 8 to 10 months.
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Based on the relief valve discharge reports submitted to Regional
offices, the rate of reactor and non-reactor discharges are not consistent
throughout the industry. Many sources have reported few, if any, releases
during the past several years, while other sources continue to have
releases on a regular basis. The decline (or absence) of any relief
valve discharges may also be due to the wording of the regulation that
states only "relief valve" discharges are required to be reported.
Plants using other safety relief devices (e.g., rupture discs only) are
not required to report discharges through these devices. The reported
releases that continue to occur are more prevalent among the older
sources using small reactor technology; however, some of these older
sources have reduced releases through application of available control
technology.
4.2.3 Relief Valve Discharges from Reactors
Relief valve discharges are classified as either reactor releases
or non-reactor releases - PVC plants experience both types while EDC/VC
plants only experience non-reactor releases. The causes of reactor
releases and measures that can be taken to prevent them are discussed in
the following sections.
4.2.3.1 Process Variations. The frequency of, and ability to
control, relief valve discharges from reactors vary among the different
polymerization processes. In addition, the frequency of discharges is
dependent on the age of the plant. Newer (and larger) reactor systems
are replacing the older systems which usually consisted of many small
reactors. These newer reactor systems provide better process control,
fewer upset conditions, and fewer emissions to the atmosphere.
Suspension/dispersion.
The newer and larger reactors are most often applied to the
suspension and dispersion processes. As mentioned above, these newer
systems provide better process control and reduce emissions. Newer
reactors have fewer piping connections, valves, and mechanical operations
per kilogram of monomer transformed to resin. The fewer number of
batches and reactors that need to be monitored when larger reactors are
utilized results in a lessened probability of relief valve discharges.
Also, relief valve discharge control equipment and procedures can be
more economically applied to new plants with large reactors.
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Older smaller reactors are usually operated closer to the rated
pressure and when an upset condition develops it becomes more difficult
to short-stop the reaction before the relief valve set pressure is
attained. Construction materials in the newer reactor systems (e.g.,
stainless steel, carbon steel) contribute to better heat transfer and
control of the reaction. The older smaller reactors are usually glass-
lined which has an insulating effect on the reactor and results in
poorer heat transfer and less control over the reaction.
Bulk polymerization.
The bulk (or mass) polymerization process has some advantages over
polymerization conducted in the aqueous medium used in the suspension
and dispersion processes. Because the bulk process is anhydrous and no
water or suspending agents are used, the process generates no foam and
energy consumption is low. Exothermic heat is removed by water-cooled
reflux condensers. The bulk process currently used in the United States
utilizes a vertical pre-polymerization (Pre-Po) reactor and a horizontal
post-polymerization (Po-Po) reactor. A new bulk process has been developed
that utilizes a vertical Po-Po reactor, but it is not currently in use
in the United States. These bulk processes have several unique aspects
that affect relief valve discharges.
Relief valve discharges from the Pre-Po reactor are unlikely because
the reaction only goes to 8 to 12 percent conversion. If a high tempera-
ture or pressure is detected in the Pre-Po, the slurry can be dropped to
an empty Po-Po reactor where the larger volume allows the low level of
initiator charged to the Pre-Po to be used up and complete the reaction.
However, reaction control is more difficult in the Po-Po reactor because
the bulk reaction is anhydrous and this results in less efficient heat
transfer to the walls of the reactor. Almost all of the liquid VC
charged to the Po-Po is used during the early stages of the reaction and
it is during this early stage that auto-acceleration of the reaction and
a rapid increase in temperature can occur. Therefore, process control
is more critical during this initial reaction stage.
If an upset situation is detected in the Po-Po reactor, the
conventional short-stopping techniques, effectively used in the suspen-
sion and dispersion processes, can not be used to terminate the bulk
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reaction because the contents of the Po-Po reactor are not fluid and
mixing is not turbulent. As a result, the short-stop agent is not
distributed rapidly or completely enough throughout the slurry.
Rhone-Poulenc has developed a short-stopping procedure, but it is only
applicable to their newer process technology utilizing vertical Po-Po
reactors (Dubec, 1980). B. F. Goodrich operates two bulk plants in the
United States and has developed a more effective gaseous short-stop
system that may be available for licensing in the future (Dubec, 1980).
Solution process.
Union Carbide operates the only facility in the United States using
the solution polymerization process. The solution process is a continuous,
homogeneous process - it is not a batch flow system like the other
processes. The solvent, which is always present, provides a heat sink
capable of preventing an accelerated reaction. In over 30 years of
operating the solution process, Union Carbide has not experienced a
reactor relief valve discharge to the atmosphere caused by an accelerated
reaction. Reactor relief valve discharges that have occurred were due
to a premature failure of the rupture disc under the relief valve
(Erdman, 1980).
4.2.3.2 Causes of Reactor Discharges. There can be many causes of
reactor relief valve discharges ranging from total power failure caused
by a natural disaster to mechanical failure of process equipment to
operator errors. Two of the more frequent causes of relief valve
discharges common to suspension and dispersion processes follow.
• The hydraulically full (hydroful) condition resulting from too
much liquid or the presence of noncondensable gases in the
reactor. This condition can be caused by instrumentation
errors or an overcharging of the reactor and usually results
in a small release to the atmosphere.
• High temperature in the reactor from an accelerated reaction.
This condition is caused by inadequate cooling and can result
in a discharge of the entire reactor contents.
Both of these conditions can result in high pressure in the reactor and
a substantial, multiphase discharge through the relief valve to the
atmosphere.
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Hydroful condition.
The VC liquid charge expands up to 13 percent when heated to reaction
temperature. Therefore, an overcharging of the reactor may not be
detected when raw materials are initially charged and the resulting
increase in pressure above the normal operating pressure will open the
relief valve when the slurry reaches the top of the reactor. Overcharging
of the reactor can result from charge meter or weigh tank errors, leaking
reactor valves, and wash-water or solvent cleaning solution incompletely
drained from the reactor.
The presence of noncondensable gases in the reactor will also cause
high pressure to develop resulting in a hydroful condition. The operating
procedure for a typical suspension or dispersion process is to charge a
reactor with water, initiator, and other constituents (depending on the
process and resin qualities desired) to about 50 percent of reactor
volume. Pressure is then reduced to about 5 kPa (0.05 atmospheres).
Vaporization of the water will sweep some noncondensable gases from the
reactor if present. Liquid VC is added under vacuum to raise the slurry
level to about 80 percent reactor volume. Liquid expansion from the
reaction temperature then raises the slurry level to about 90 percent
reactor volume. The concentration of any noncondensable gases present
at 50 percent reactor volume can be increased by up to five times.
Because the combined VC and water vapor pressure at normal operating
temperatures can reach about 1,000 kPa (150 psia) and relief valve
systems are usually set at 1,300 kPa (195 psia), the presence of only
5 percent noncondensable gases in the vapor space prior to VC liquid
charging could trigger a release. The sources of noncondensable gases
in the reactor include:
• gases not removed by initial evacuation during preparation for
a new batch,
• gases dissolved or entrained in the VC liquid charge, and
• leakage from reactor valves into the reactor after vacuum
treatment and before heating to reaction temperature.
In the case of a hydroful condition caused by overcharging or the
presence of noncondensable gases, the increased pressure causing the
relief valve to open is quickly relieved by liquid and vapor flows
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through the valve. The relief valve will reseat itself under most
circumstances after pressure is released. However, if the relief valve
does not reseat properly or pieces of a blown rupture disc become lodged
in the valve preventing complete closure, a larger volume of reactor
contents will continue to be discharged until temperature and pressure
are brought under control.
Accelerated reaction.
The polymerization reaction is exothermic and the reaction heat
produced is controlled by circulating cooling water through the reactor
jacket. The reaction normally takes place at a temperature and pressure
of approximately 55°C (130°F) and 1,000 kPa (150 psia). As the reaction
proceeds, the polymer tends to coat the inner walls of the reactor
reducing heat transfer effectiveness and, because reactors are no longer
opened as often, more consecutive batches are run and polymer continues
to coat the inner reactor walls. However, new clean reactor technology
has reduced this polymer build-up even though reactors are not opened as
often. In some of the newer systems, water jets clean the inner walls
after each batch to prevent polymer build-up and loss of heat transfer
effectiveness. The use of clean reactor technology or other proprietary
methods for reduction of polymer build-up allows the most efficient heat
transfer through reactor walls and thus reduces the danger of
auto-acceleration due to high reaction temperatures.
For suspension and dispersion processes, an auto-acceleration of
the reaction occurs with increased heat evolution at some point around
the 50 percent conversion level. Heat transfer effectiveness and control
of the reaction during this period depend on vigorous agitation of the
slurry and an adequate supply of cooling water applied to the reactor
jacket. A malfunction of these systems will result in rapid heating and
an increase in pressure that could cause the relief valve to open.
The loss of agitation is the greatest concern because heat transfer
is significantly reduced. Inadequate heat removal during the auto-
acceleration period will usually result in a major discharge (possibly
the entire contents of the reactor) because of the rapid rise in
temperature. An increase from the normal reaction temperature of 55°C
(130°F) to 72°C (162°F) or a total increase of 17C° (32F°) can result in
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the sum of the VC and water vapor pressures reaching the relief valve
discharge pressure setting.
However, if the reaction is in its later stages (greater than
80 percent conversion), most of the VC will have been used up. This
decreases the potential quantity of emissions through the relief valve.
In the earlier stages of the reaction all of the VC would be vaporized,
unless a shortstop agent were added to the reactor to kill the reaction.
Addition of a shortstop agent usually requires that agitation still be
available for distribution throughout the slurry. Conoco has developed
a shortstop agent that is effective without agitation. This new
development will be discussed in a subsequent section.
4.2.3.3 Prevention of Reactor Discharges. Proper instrumentation
to detect upset conditions, gasholder equipment, and an automatic inhibitor
solution (shortstop agent) addition systems can be used to eliminate
many of these relief valve discharges (EPA, 1975). However, there are
many other variables that must be considered for the above three controls
to be successful. The following sections discuss other generic control
measures, in addition to the EPA-recommended methods, used in the VC
industry to prevent relief valve discharges.
4.2.3.3.1 Current generic preventive methods. Methods currently
used by PVC plants to prevent emergency relief valve discharges follow.
Shortstop systems.
A shortstop or kill agent system can be used to stop the polymerization
reaction when upset conditions develop. A shortstop system injects a
chemical agent into the reactor which terminates the reaction by inhibiting
the action of the initiator. The system is either manual, automated, or
a combination of the two. The manual system generally uses high pressure
water injection with the same equipment used to charge the reactor with
initiator (Ledvina, 1980). Depending on the kill agent system used,
success of the manual system is usually dependent on having agitation
for complete dispersion of the shortstop throughout the slurry, the
charge manifold being clear (this is a manifold used to charge ingredients
to the reactor) and the availability of necessary personnel.
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Several variations of the automated shortstop system exist. The
newer computer-controlled plants have built-in programs that recognize
the upset condition by monitoring operating parameters and automatically
injecting the shortstop agent. For example, one plant has installed
motion sensors on the reactor agitator that sense when power has been
lost and a pressure build-up is beginning. A shortstop agent is then
automatically injected into the reactor (Ethyl, 1980). Under this
particular condition, an alternative source of pressure would be needed
to open the valve and inject the shortstop agent if power loss were the
cause of agitator failure. Any shortstop system employed would have to
be connected to other vessels that might receive the slurry under upset
conditions because active initiator may still be present in the slurry
even if it is dumped to a blowdown or holding tank.
Instrumentation.
The degree of instrumentation is important in preventing relief
valve discharges and varies greatly among plants. Those plants most
successful in preventing discharges have several levels of back-up
instrumentation. The instrumentation monitors reactor operating para-
meters (e.g., pressure, temperature) and either warns operators of an
emergency condition or takes action automatically. Instruments
monitoring the reaction can be tied into a computer system receiving
data from instruments on and in the reactor or they can be locally
mounted units on each reactor. Selection of operating parameters to be
monitored is critical. For example, a temperature sensor mounted on a
baffle can become fouled by polymer build-up. The temperature reported
by the sensor can lag behind the actual temperature of reaction.
Therefore, pressure sensors may be a better indicator of the actual
temperature. In most cases a combination of the two is more reliable.
Other instruments, in addition to those monitoring actual reaction
conditions, will contribute to the prevention of an upset condition.
For example, overcharging a reactor is a common cause of relief valve
discharges. A metering system for charging exact amounts of liquid VC
and other ingredients in combination with accurate weigh tanks can
prevent overcharging and the subsequent hydroful condition. Dual
metering in series for both VC and water can help prevent overcharging.
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Upstream filters can help maintain meter accuracy (Ullrich, 1981). A
level control on the reactor that is attached to an alarm system would
indicate overcharging. One company indicated success in using a
radioactive source detected by ion chamber sensing to determine the
level in the reactor prior to beginning the reaction. Reactors mounted
on scales help to prevent overcharging. Agitator seal-water leaking
back into reactors could also cause an overcharging condition. This
leakage can be prevented with an electrically operated shut-off valve
for the seal-water system. Other examples of instrumentation to prevent
relief valve discharges will be discussed in more detail in the next
section describing some of the preventive systems currently used by the
VC industry.
Auxiliary power supply.
The effectiveness of the above examples of instrumentation systems
as well as other preventive systems is dependent on the availability of
power to run these systems. Auxiliary sources of power are necessary to
maintain agitation, cooling, and instrumentation in the event of losing
the main power source to a plant. No auxiliary power systems currently
found in PVC plants are designed to operate the entire plant -- enough
power is usually only available to safely shut down the plant by allowing
those polymerization reactions in progress to be terminated or finished.
Most plants have dual power lines into the plant to provide primary
power. The dual lines keep power constant and prevent sudden surges and
dips in power or a complete loss of power. Emergency back-up power is
usually supplied by diesel-driven generators.
Back-up power may also be supplied in the form of an auxiliary
source of instrument "air" that would be necessary to open valves to
recovery or for the injection of shortstop agents. One plant uses high
pressure, precharged nitrogen to provide pressure. All other valves
needed for operation during an upset condition for an orderly shut-down
are also nitrogen operated (Ledvina, 1980).
Auxiliary venting system.
An auxiliary venting system could be used to prevent the minor
releases usually caused by the hydroful condition. The venting system
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would be connected to existing recovery systems or control devices.
Variations of this type of system are currently used by some PVC plants.
The auxiliary venting system is designed for two-phase relief and
blowdown flows and can-be used for minor events in which removal of a
small quantity of material from the reactor will prevent over-pressuring
and a more serious condition from developing. This auxiliary venting
system could be used for the following conditions:
• overcharge of the reactor,
• presence of noncondensable gases,
• moderate reaction rate increase, and
t heat transfer reduction.
The vent line would be set at a pressure above normal operation pressure,
but below the safety relief valve pressure. The vent line would then
automatically open at this pressure or it could be activated from the
control panel.
A computer program developed for two-phase flow through a relief
valve is used in conjunction with the specific process design to select
the relief valve opening pressure and size the necessary equipment. The
program simulates the rate of pressure rise in the reactor and rate of
venting from the reactor. Using this program, the relief valve and
header system are sized and the pressure profile in the relief header is
determined for the required relief flow rate so that all back pressure
limitations at various points along the system are met. The program
also determines maximum possible blowdown flow rate for given inlet and
outlet pressures and for a given pipe header configuration (Richter, 1978,
pp. 145-152).
A typical auxiliary relief valve system would consist of the following:
t polymerization reactor,
• relief valve (not open to atmosphere),
• knock-out drum for liquid/vapor separation,
• header system connecting relief valve and knock-out drum,
• blowdown tank, and
• blowdown header system.
The auxiliary vent line would be connected into a knock-out tank to
prevent a carryover of liquid or solid. Vapor from the knock-out drum
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can be vented to the existing recovery system, a gasholder, or control
device; slurry is pumped from the blowdown tank. It is assumed that
pressure in the system is atmospheric and back-pressure from the vent to
recovery or control is negligible (which may not always be the case
(Richter, 1978)). Sizing of all equipment is based on the computer
program results that also give a history of conditions in the reactor
and determine when the relief valve will close. The estimated the cost
of an auxiliary venting system for a 38,000 liter (10,000 gallon) reactor
system, assuming availability of a blowdown tank, using December, 1979,
dollars. These costs are shown in Table 4-8.
Table 4-8
ESTIMATED COSTS FOR AN AUXILIARY VENTING SYSTEM
Auxiliary venting Eight 38,000 liter
system (10,000 gallon) reactor*
Knockout tank 419,300
Pump and motor 15,800
Piping 224,500
Instruments, control valves 65,200
and safety devices
Building and site development 95,700
Total Physical Cost $820,500
*The venting system proposed would accommodate an eight reactor line.
Chilled Water System
Many plants maintain a separate supply of chilled water other than
normal jacket cooling water for upset conditions resulting from reduced
heat transfer. The water is usually brine-cooled and temperatures range
from 4°C (40°F) to 10°C (50°F). In the event of an increase in tempera-
ture, the chilled water can be pumped into the reactor jacket to slow
the reaction. This replacement can be done in approximately 5 minutes.
The chilled water can also be injected directly into the batch or into a
blowdown tank where the batch might be dumped.
Operator Training Programs
A staff of qualified operators able to recognize a potential emergency
situation and take appropriate measures to prevent the situation will
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help to minimze relief valve discharges. The different levels of computer
control help to eliminate common operator errors and aid the operator in
detecting potential problems, but the computer does not provide the
decision-making capabilities that are only found in experienced operations
personnel. The right combination of operator experience and computer
control can help to eliminate relief valve discharges.
Operator training programs vary from company to company. Training
programs range from several weeks to over a month with year-to-year
retraining and refresher programs also offered. Polymer operators are
trained to deal with run-away reactions - how to recognize them and what
steps are necessary to bring them under control. At least one company
has instituted a disciplinary system for those operators responsible for
a run-away reaction and the relief valve discharge if it occurs (Laundrie,
1980).
Flares.
A flare can also be used to help control a relief valve discharge.
As mentioned in Section 4.1.4, one company uses a flare as an equivalency
to a rupture disc in order to prevent fugitive emissions through the
relief valve - the relief valve is connected directly to the flare. The
flare is designed for relief valve discharges originating from upset
process conditions and will accommodate two reactors simultaneously. A
knock-out drum is installed between the relief valve and flare to prevent
liquid entrainment. The flare has only handled minor discharges but
could receive the entire reactor contents (i.e., worst-case condition).
This method does not eliminate relief valve discharges, but only helps
to minimize the emissions from this source. Safety and cost considera-
tions (e.g., supplemental fuel needs) must be evaluated before applying
this control method to relief valve discharges.
Gasholders and other containment methods.
A gasholder is a cylindrical, variable-volume vessel. The most
common type of gasholder is a vessel with a floating roof with either a
water seal or a double inner synthetic seal that expands to accommodate
the influx of gas. The water-sealed gasholder has a longer life because
there is no seal failure, but the water seal is a constant source of VC
fugitive emissions and freezing must be prevented in colder climates.
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The operating principle of a gasholder is based on piston displacement.
A frictionless movable piston floats on the confined gas - rising and
falling with changes in the volume of stored gas. As gas enters and
builds up to the designed operating pressure, the piston rises and
floats on the gas.
Gasholders are currently being used as part of the recovery system
to contain and store VC gas collected from various emission sources in
the plant. The gases stored can be fed to the recovery system or the
gasholder can serve as a surge vessel feeding the primary control device
(incinerators must receive a near constant flow and concentration of
combustibles for proper operation).
Gasholders can be used to help prevent relief valve discharges
without actually receiving or containing the entire reactor charge.
Currently there is no plant that has connected a relief valve directly
to a gasholder or uses a gasholder only for relief valve discharges.
One plant manually relieves pressure to the monomer recovery system
gasholder when a batch is out of control (Brumbaugh, 1980). The plant
identified several problems that can occur if the gasholder is used for
this purpose. As discussed previously, a multi-phased discharge can
occur and slurry can carryover to the gasholder. The plant installed a
knock-out tank to prevent this carryover, but it does not always handle
the relief valve flow. Also, this plant's gasholder is part of the
recovery system and capacity is not always available to handle the
entire VC charge to a reactor.
The auxiliary vent system previously described for minor relief
valve discharges would not be as effective in preventing a discharge
caused by an accelerated reaction that could result in a major release
or release of the entire reactor batch. Prevention of the major relief
valve discharge would require two different types of control technology -
the auxiliary vent system and a containment system such as a gasholder.
A gasholder for the purpose of containing a major relief valve
discharge would have to be designed to accommodate a worst-case condition
for one reactor (the entire reactor charge), and would have to be dedicated
to that service only. Simultaneous discharges from many reactors would
require many gasholders. The same knock-out tank described for the
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auxiliary venting system would be a part of the gasholder containment
system. There would be a separate line from the knock-out tank that
would go directly to the existing recovery system or control device for
the purpose of controlling minor releases. However, the knock-out tank
would have a back pressure valve set to open to the gasholder in the
event of a major release.
This review study, Conoco Research Division (Ledvina, 1980) and the
B.F. Goodrich Chemical Group (Holbrook, 1980b) have evaluated the gasholder
potential for containing relief valve discharges only and the following
discussion is based on this research.
Typical specifications for a gasholder to contain a relief valve
discharge from a 38,000 liter (10,000 gallon) reactor (assuming 1.4:1.0
water to VC charge ratio) is shown in Table 4-9.
Table 4-9
TYPICAL GASHOLDER SPECIFICATIONS
FOR 38,000 LITER (10,000 GALLON) REACTOR
Dimension Specification
Volume 5,700 m3 (200,000 ft3)
Diameter 24 m (75 ft)
Height 15 m (48 ft)
Seal water
The estimated capital costs for installation of the above gasholder for
a 38,000 liter (10,000 gallon) reactor, assuming the use of an existing
recovery system for the vapors in the gasholder, based on December, 1979,
dollars is indicated in Table 4-10. The estimated total cost does not
include the cost of the auxiliary vent system with knockout tank in
Table 4-8 which increases the total system cost by approximately $821,000
to $4,802,100. Accuracy of these costs are ± 30 percent. Insurance,
taxes, recovery credits and other miscellaneous charges are not included.
B.F. Goodrich estimated the cost of a similar gasholder system with
14,000 m3 (500,000 ft3) capacity to be approximately $3,000,000
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Table 4-10. ESTIMATED COST FOR INSTALLATION OF A GASHOLDER
Pnirinman* C°St f°r 38,000 liter
Equlpment (10,000 gallon) reactor
Gasholder $ 883,400
Piping 382,200
Safety 70,400
Site development 232,900
Header extension from KO tank 600,000
Engineering and construction 1,070,000
Contingency 648,000
Operation and maintenance 94,200
Total System Cost $3,981,100
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(Holbrook, 1979). Their cost was based on earlier dollar values and did
not include operation and maintenance costs. Conoco estimated a gasholder
system alone without the auxiliary venting system (i.e., knock-out tank
and blowdown tank) to be between $2,000,000 and $4,000,000 for fabrication
o
and installation of a gasholder with synthetic rubber seal and 14,000 m
(500,000 ft3) to 42,000 m3 (1,500,000 ft3) capacity. The life of the
synthetic rubber seal is estimated at about 2 years and the replacement
cost is 5 to 10 percent of the original gasholder cost. Replacement
time is 4 to 6 weeks and seal delivery takes 20 to 22 weeks. Thus, a
second gasholder would be required to prevent potential emissions from
relief valves during downtime for seal replacement.
Therefore, the estimated capital cost for installation of a gasholder
system for containment of a relief valve discharge will approach $5,000,000
(and several gasholders may be required). This system would be for
containment of one 38,000 liter (10,000 gallon) reactor and does not
take into consideration the possibility of multiple reactor relief valve
discharges.
Experience with gasholders indicates that the following conditions
and considerations must be evaluated to ensure trouble-free operation:
• The gas from the reactor must be clean and free of suspended
solids and liquids. Polymer carryover could cause line
plugging which can result in backpressure to the reactor.
• The gas or mixture must be unreactive, non-corrosive, and
non-explosive.
• There must be no condensation in the gasholder system or
transfer lines could freeze.
t Water seals probably represent the best type of seal for
trouble-free operation.
• Based on a computer simulation assuming adiabatic cooling
conditions for the reactor, transfer of reactor contents at a
limited rate that would allow only vapor to be vented would
result in a gain of 0.1 to 1.5 minutes until the safety device
to the atmosphere would open. Transfer is limited to this
rate to avoid slurry (and foam) carryover.
• The maximum fill rate of a conventional gasholder, which is
limited by expansion of the inner seal, will also limit the
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venting rate. The maximum piston velocity for a rubber-sealed
gasholder is approximately 4.6 m (15 ft) per minute and would
require about 6 to 8 minutes to fill - this seal expansion
rate thus may limit the venting rate of the reactor contents.
A venting system to the atmosphere must be present on the
gasholder should the gasholder not be able to accommodate the
discharge.
3 3
• For a gasholder with a capacity of 14,000 m (500,000 ft ) to
42,000 m3 (1,500,000 ft3) a horizontal knock out vessel with a
capacity of 8,000 m3 (300,000 ft3) to 14,000 m3 (500,000 ft3)
would be required. The length of the vessel would be 46 m
(150 ft) to 54 m (175 ft). The pressure drop in the line from
the gasholder to the knock out drum can not be controlled,
therefore the KO drum pressure must be atmospheric.
• The potential for back-pressure on the reactor relief valve
must be evaluated. Conventional relief valves can take up to
10 percent of the set pressure before it reseats. A balanced-
bellows relief valve can take 40 to 50 percent of the set
pressure. A pi tot-operated relief valve can be opened on a
differential pressure basis, but because of the small pitot
tube diameter, this type is only intended for clean service.
• Relief valves to the atmosphere are designed to discharge
directly to the atmosphere such that the explosion risk caused
by VC flammability levels of 3 to 30 percent and worker exposure
are minimized. Failure of the gasholder during an upset
condition could result in a vapor cloud at low level because
of the high concentration of VC at low pressure in the gasholder
and low velocity of the vapor.
The above gasholder containment system could be designed into a PVC
plant. Techniques such as elaborate monitoring and alarm systems,
freeze protection, inert gas purging systems, strict personnel training
programs, and inspection routines would be necessary to minimize some of
the safety hazards. There are other systems that minimize relief valve
discharges, including the use of a gasholder to help prevent these
discharges. However, no matter what system or combination of systems is
4-38
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utilized, a safety relief device directly to the atmosphere will always
be required.
Another containment device that can be used to help prevent relief
valve discharges is a blowdown or spare slurry-holding vessel. These
vessels are usually used for stripping the batch of residual VC or for
blending with other batches. A blowdown or holding tank is a constant
volume, nonpressurized vessel (some may be pressurized) that would allow
an influx of gas until the pressure of the tank and the source of pressure
are equalized. The tank can also take the slurry directly and have
chilled water and short-stop agent waiting for control of a run-away
reaction. Discharge of the slurry to this tank can be manual or auto-
activated. The timing of gas venting, slurry dump, or both, is critical
in order to prevent the relief valve on this holding vessel from opening.
These holding vessels can be used in combination with a gasholder or the
recovery system to successfully control an upset condition—the reactor
vapors are vented to the gasholder or recovery while the polymer slurry
is dumped to the blowdown tank, or the entire reactor contents are
dumped to the blowdown tank and pressure relieved from this tank to the
gasholder or recovery system.
Pressurized containment can also be used to help prevent a relief
valve discharge. B.F. Goodrich replaced their gasholders with this type
of pressurized containment which they refer to as a "burp" tank. The
purpose of the burp tank is to prevent emissions to the atmosphere as
part of the VC recovery system, but the tank can also be used to assist
in preventing relief valve discharges (Hoibrook, 1980a). This automatic
pressure reduction system usually will open at a pressure between
operating pressure and the pressure relief valve setting. The vapors
from this system go to recovery or the primary control device.
Other methods for preventing relief valve discharges.
Periodic pressure tests run on the reactor will decrease the
likelihood of premature failure of rupture discs. Other preventive
maintenance areas pertaining to rupture discs include (Ullrich, 1981):
0 Premature disc failure can be caused by defective metal. This
can be minimized by paying the disc supplier to pre-test a
fraction of the lots before shipment.
4-39
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• Premature disc failure is likely if the maximum operating
pressure is exceeded. This pressure ranges from 70 to
90 percent of the burst pressure, depending on the type of
disc. Once the maximum operating pressure is exceeded, the
disc is deformed and must be replaced to ensure that it does
not fail below the burst pressure. It is believed that in a
computer-controlled plant, the chance of exceeding the maximum
operating pressure, and thus the frequency of premature disc
failure, is reduced.
• Rupture discs in vinyl chloride service, particularly on PVC
ractors, are subject to pressure cycling, and therefore must
possess the best fatigue resistance. The discs should also be
replaced at a frequency determined by operating experience.
One plant also monitors all plant devices (e.g., valves, pumps, flowmeters,
instruments, controllers) before charging the reactor to verify their
successful operation and ensure safe operation during the polymerization
reaction (Holbrook, 1980).
Another newer preventive method is a multiple initiator system.
This system maintains a high initiator rate early in the reaction cycle
and a slower initiator rate during that part of the cycle when auto-
acceleration is expected to occur. The system thus maintains a near
constant temperature and pressure during the reaction.
4.2.3.3.2 Preventive systems currently in use. Several systems
for prevention of relief valve discharges have been installed by PVC
plants. These plants all use a combination of equipment and work practice
procedures to prevent or minimize relief valve discharges to the atmosphere.
Several of these systems are discussed in the following subsections.
B. F. Goodrich Company. B. F. Goodrich produces PVC resins by the
suspension, dispersion, and bulk polymerization processes. The new,
larger reactors as well as the older, smaller reactors are utilized in
their processes. B. F. Goodrich used gasholders extensively as part of
their recovery system, but have since replaced the gasholders with
pressurized burp tanks (that provide direct recovery) with high volume
liquid ring compressors. Following is a discussion of their relief
valve discharge prevention systems (Holbrook, 1980c).
4-40
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B. F. Goodrich has reduced releases from reactor safety relief
valves in their large reactor suspension PVC systems. This was accom-
plished through process control with emphasis on early detection and
analysis of abnormal conditions. A totally computer-controlled system
was installed to detect these abnormal conditions and take the appropriate
action with a minimum of operator involvement. A thermal model was
developed to simulate the typical controlled polymerization reaction and
a kinetic model was developed to compare the typical reaction with an
actual reaction. When the computer recognizes a potential upset
condition, preventive control methods can be implemented and the upset
conditions are then brought under control.
B. F. Goodrich identified three conditions that can result in a
relief valve discharge from the large reactors - equipment failure,
hydroful conditions, and an accelerated polymerization reaction. Some
equipment can be kept in service with an emergency generator and back-up
instrumentation. Equipment failure can be minimized by preventive
maintenance following a regular schedule. The other conditions are
minimized by computer control, but in the event of a high pressure
situation in the reactor preventive steps are taken immediately. The
large suspension reactor system is followed by a larger blowdown or
flash tank which is generally 1.5 times as large as the reactor.
Normally, the purpose of the blowdown tank is to receive the polymer
slurry before the process is complete so the reactor can be prepared for
the next charge. The blowdown tank has both an agitation and a shortstop
system and thus can also receive the slurry under upset conditions so
that an accelerated reaction can be brought under control. A recovery
separator tank, preceding the recovery system, knocks out entrained
liquid that would be vented during an abnormal condition. To relieve
reactor pressure, if a hydroful condition exists, the computer
immediately stops the addition of reaction ingredients. If the pressure
is not due to a hydroful condition, but is due to a runaway reaction,
the following control functions are triggered:
• Full cooling to the reactor and blowdown tank.
• Addition of reaction shortstop.
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• Recovery of VC from the reactor.
• Opening of exhaust vents to a recovery separator to relieve
pressure.
• Pump-out of reactor into a blowdown tank.
In addition to the above process controls, all plant devices (e.g.,
valves, pumps, flowmeters, instruments, and controllers) are monitored
before the reactor is charged to verify their successful operation and
ensure safe operation during the polymerization reaction.
The computer control system information display has been
centralized and the following back-up systems have been installed:
• Dual power lines into the plant.
• Emergency power generation to maintain cooling and agitation
should a primary power failure occur.
t Emergency power supply for computer and instruments.
• Manual control of instruments should a power failure occur.
• Instrumentation backup for computer.
• Installation of redundant equipment (pumps, compressors, and
flowmeters).
The above combination of control technologies for relief valve
discharge prevention has resulted in no reactor relief valve releases
for 31,000 charges at their large reactor facilities.
B. F. Goodrich has also developed an effective relief valve discharge
prevention program for their smaller reactors using many of the preven-
tive measures described earlier. Similar to the large reactor systems,
there are three conditions that B. F. Goodrich feels can result in
releases from the small reactor suspension and dispersion processes
- equipment failure, hydroful conditions and accelerated polymerization.
Equipment failure is prevented by an emergency generator, backup
instrumentation, and preventive maintenance that follows a regular
schedule.
A hydroful condition is controlled in a manner similar to the large
reactor system described above. When the computer detects excessive
pressure in the reactor caused by a hydroful condition, all valves are
closed to the reactor except cooling water, charging is stopped, the
4-42
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slurry is sent to a blowdown tank, and vents are opened to a separator
recovery tank (knockout tank) to relieve reactor pressure. The accelerated
polymerization reaction (high reactor pressure and temperature) prevention
follows the same initial preventive steps for the hydroful condition.
In addition, water is injected directly into the reactor to cool the
contents. The reactor is then vented to the prevent or burp tank
(pressurized containment vessel) to relieve pressure, and a shortstop
agent is injected to kill the reaction.
Conoco Chemical Division. Conoco has done research at their pilot
facility to develop a prevention for relief valve discharges. An elaborate
kill system is the primary method for preventing a discharge to the
atmosphere. Tests were conducted in Conoco's large reactor pilot plant
to determine the effectiveness of their kill system in stopping the
polymerization reaction and the resulting pressure rise in a PVC reactor
(McCulley, 1980). The tests were planned to simulate the concurrent
loss of reactor agitation and cooling that would occur during a power
failure or a worst-case situation. In each of the test runs, the simulated
power failure was started 3 hours into the polymerization reaction to
ensure that the reaction rate was near its maximum. Also, the reactor
pressure was allowed to increase from its normal pressure of 118 to
119 psig up to 140 psig before injecting the killing agent. The 7 to 11
minutes required for this pressure increase provided sufficient time for
the swirling inside the reactor to stop; this minimized mixing of the
kill agent with the reaction mass.
The kill agent was pressured through a nozzle (no spray nozzle or
other distribution device was used) into the vapor space of the reactor.
The investigators suspected that the kill agent simply ran down the
sides of the reactor into the slurry and did not benefit from injection-
caused mixing. The liquid kill agent used is soluble in the liquid VC.
Results showed that after injection of the killing agent at 140 psig,
reactor pressure continued to increase to a maximum of 150 psig over
approximately 8 minutes (about 20 minutes into test). The reactor
pressure then slowly decreased to 146.5 psig 70 minutes into the test
run - the gradual pressure drop probably was due to heat losses from the
reactor to the atmosphere.
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These tests confirmed that, if sufficient killing agent is injected,
the polymerization reaction can be stopped and the rising reactor pressure
can be controlled during a major power failure or other condition that
results in total loss of cooling and/or agitation.
Early detection of an upset condition and control equipment redundancy
are the most important requisites to preventing an emergency situation
from reaching the kill system stage of control.
Conoco feels there are four major causes of a relief valve discharge:
• operator error,
• general equipment malfunction,
• events external to the system, and
• specific failure of the kill system.
In order for any of the first three events to result in a release,
the fourth event, failure of the kill system, must occur. Specific
examples of operator error and equipment malfunction (overcharging
reactor, cooling system failure, etc.) have already been discussed.
Examples of external events are power failures, fires, or some natural
disaster.
The early detection program includes the following:
• Two sets of reactor temperature and pressure indicators on the
control panel (from separate transmitters) are supplemented by
pressure gauges on each reactor. (Use of temperature indicators
represents a level of redundancy because an increase in VC vapor
pressure will be accompanied by a rise in temperature.)
• Operators are always in 2-way radio contact with control panel
personnel.
• High pressure and high temperature alarms sound in the control
room and, if acknowledged, turn off. If the pressure continues
to rise, a second alarm, set at a higher pressure, sounds and
cannot be shut off until the reactor pressure drops below its
set point. This alarm also sets off a siren which can be
heard throughout the plant.
• A temperature control instrument on the control panel regulates
the water flow to a reactor. If this flow is improperly regulated,
4-44
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a panel switch can be used to override the controller, sending
maximum cooling water flow to the reactor.
• The panel has reactor amperage indicators with alarms. A low
amperage reading is used to confirm that the reactor has emptied
after stripping to avoid overfilling the reactor on the next charge.
Low amperage can result from a failure in the agitation system.
• There is a back-up power system for the control panel.
• Cooling water for reactors. Provisions are made to supply water
to the reactor from cross-ties with city water or from the fire-
water pumps (diesel-driven). Each of these capabilities is checked
once each week. Also, instrumentation prevents this backup
cooling water flow from going to users other than the reactors.
• A severe-weather radio provides current weather conditions that
may affect the plant (e.g., storm conditions that could cause
a total power failure to the plant).
t A reactor can be vented to an empty vessel or the recovery
system to reduce pressure.
If the above early-detection prevention methods and redundant equipment
are not adequate to bring the reaction under control, then the kill system
is implemented. Two kill systems are maintained. The first kill system
uses high pressure water injection. It is a completely manual system
and is used to control reactor pressure increases during normal plant
operation. It cannot be used in the event of a power failure.
If agitation is lost due to equipment failure or loss of power, the
second kill system can be used. This second system uses high pressure
nitrogen injection (precharged), and is a remotely operated system
backed up by a manual injection line. In this situation, valves are
also nitrogen operated. This kill agent is effective without mixing.
The system has been tested in Conoco's pilot plant and has proven to be
effective under worst-case conditions including loss of reactor cooling
or agitation.
The kill systems for each reactor can be activated from the control
board or locally at the reactor. The system from one reactor can be
used on a different reactor, and each system contains enough shortstop
4-45
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agent for two complete kills in one reactor. Two racks of back-up
nitrogen bottles are available for instrumentation use.
To contain a plant fire, which could result in an an emergency
discharge, a fixed-spray fire fighting system was installed throughout
the VC areas of the plant. Hydrocarbon (HC) sensors detect explosive
concentrations with an alarm set at 20 percent of the lower explosive
limit (LEL) and watering systems are triggered at 40 percent of the LEL.
These HC detectors are independent of the fugitive emission detection
system required by the current regulation. Fire sensors throughout the
areas where VC is handled monitor on a rate-of-temperature-rise basis.
Back-up cooling is used instead of a back-up power system. The
rationale is that if the emergency situation is due to a broken agitator
shaft, motor, pump, etc., back-up power will not alleviate the situation.
The second kill system described above always accommodates these types
of situations.
Both of Conoco's plants use an extensive interlock system to prevent
mistakes that could release VCM to the atmosphere, damage equipment, or
otherwise seriously effect the plant operation. For example, there is
an interlock which prevents the reactor dump valve from opening if the
reactor is under pressure, thereby avoiding the accidental dumping of a
reactor containing a large amount of VCM. The Aberdeen plant uses
programmable logic controllers for its interlock control system. The
Oklahoma City plant uses a hard-wired relay logic system.
Hooker Chemical Company. As discussed previously, the bulk
polymerization process presents some disadvantages for prevention of a
relief valve discharge. The process is anhydrous resulting in poor heat
transfer and agitation is slow which makes shortstop agents difficult to
disperse throughout the dry slurry. Pre-Po reactor control is easier
because the reaction only goes to 8 to 12 percent conversion and if a
high pressure condition develops, the slurry is dropped to an empty,
larger Po-Po reactor where the initiator is used up and the reaction
brought under control. Also, the liquid VC charged to a Pre-Po provides
some heat transfer and better temperature monitoring. Therefore, Po-Po
reactor control is more important in the bulk process.
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Hooker Chemical Company prevents relief valve discharges through a
combination of equipment installations and work practice procedures
(Dubec, 1980). Pre-Po and Po-Po reactors are mounted on scales that
provide back up control for overcharging of reactors. In order to
better monitor temperature in the Po-Po, reflux condensers were
retrofitted to the reactor so exothermic heat of reaction can be removed
by the circulation of water through the condensers.
If upset conditions develop in the Po-Po reactor, the following
manual procedure is followed:
• The Po-Po reactors are equipped with pressure alarms that activate
when the reaction pressure increases above normal operating
pressure, thus alerting operators of the upset condition.
• The reflux condensers are flooded with water to control the
temperature.
• The Po-Po reactor undergoes degassing.
• Valves are opened back to the recovery system which is a
brine-cooled system.
t Cooling water at 10°C (50°F) from chilled tanks (also a
brine-cooled system) is pumped into the reactor jacket to slow
the reaction.
• At this point if the above steps have not brought the reaction
under control and time is still available, pressure will be
manually released to keep the rupture disc from blowing.
When the above steps are not effective, then the rupture disc will
eventually rupture and the reactor will discharge to the atmosphere. As
mentioned previously, the critical time for the bulk process is the
first half of the reaction. Beyond this midway point, the unreacted VC
has been substantially reduced and the reaction is more easily controlled.
This particular plant does not use a shortstop agent in the procedure,
but such an agent may be available in the future.
Also, two power lines have been run into the plant to prevent a
total loss of power. In the event that total power is lost to the
plant, two emergency generators provide the power necessary to control
the reactions in progress and safely bring the plant down in about 12
hours without any relief valve discharges.
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General Tire Chemical Division. General Tire has older, small
reactor technology for the suspension process and uses a gasholder with
a capacity of 1,400 m3 (50,000 ft3) to help prevent relief valve dis-
charges from the suspension reactors (Laundrie, 1980). The main purpose
of the gasholder is for venting compressor relief valves, pumps, transfer
lines, weigh scales, condensers and knock-out tanks. Emissions from
reactor opening and the slurry and wastewater strippers are also vented
to the gasholder. VC collected in the gasholder is recovered and returned
to the process.
When an upset situation is detected in a reactor, the following
procedure is followed:
• Each reactor is equipped with a high pressure alarm which
signals a potential upset situation.
• If possible, the reaction is vented to the gasholder to relieve
pressure. A KO tank prevents entrained slurry from reaching
the gasholder, but this is not always possible.
• A chemical shortstop agent is manually added to the reactor.
• The batch is dropped into a stripper vessel or pressure is
equalized to an empty reactor.
• Cooling water pumps are on separate electrical circuits to
prevent a loss of cooling water during power supply outages.
A back-up water supply is available if primary cooling water
is lost.
• Electrical power is supplied to the plant by two separate
feeders. The system automatically switches to the other
feeder if power fails on one feeder.
If the above procedure is not successful, then the reactor is manually
vented to the atmosphere. Because this is an older plant with less
sophisticated instrumentation, more responsibility for prevention
of relief valve discharges falls upon the operators. Polymer operators
have been trained to deal with runaway reactions - how to recognize them
and what steps are necessary to bring them under control.
4.2.4 Non-Reactor Relief Valve Discharges.
Safety relief devices are found on all pressurized equipment in
EDC/VC plants and PVC plants. These devices may be rupture discs,
4-48
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single or in series, or combination in-line rupture disc and relief
valve. In most cases non-reactor relief valves discharge less than
reactor relief valves. During the original standard-support study
(EPA, 1975), emphasis for control was placed on reactor safety relief
valves. However, Regional offices indicate that the non-reactor releases
are equally important. Tables 4-6 and 4-7 shows the frequency and
quantity of VC discharged through non-reactor relief valves.
The following section describes some of the typical causes of
non-reactor relief valve discharges and some of the actions taken to
prevent their occurrence. Some of the discussion pertains to reactor
relief valve discharges where common equipment is utilized.
Failure of rupture discs. The premature failure of rupture discs
alone, in series or in combination with relief valves is the most common
cause of discharges. Section 61.65(b)(4) requires a rupture disc to be
installed between equipment and relief valves to prevent fugitive emis-
sions from these relief valves. Rupture discs were installed for this
purpose and failure of these discs was responsible for the majority of
the non-reactor (as well as reactor) relief valve discharges reported
initially after the waiver period. Some of the causes (and corrective
measures taken) for rupture disk failure include:
• Overrated pressure capacity. Many rupture disc manufacturers
rated their discs at a specific pressure, but failure sometimes
occurred at a much lower pressure. This problem was usually
solved by a reliable quality-assurance program that guarantees
the rated capacities on the discs.
• Compatibility with process design. There are several types of
rupture discs commercially available, but not all are compatible
with a specific process design. For example, one bulk plant
installed rupture discs on all pressure vessels and they
continually failed below their rated capacity even though
testing showed the disc capable of handling that capacity.
After experimentation with several different types, reverse
buckling discs were found to be successful, but only after the
process piping was replaced. Another plant could not use
knife-head discs because, with their process, these discs were
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susceptible to cracking at the welds. Finding the compatible
rupture disc sometimes requires trial-and-error.
• Corrosion of rupture discs. Failure of many discs is caused
by corrosion from process material coming into contact with
the disc. Corrosion caused by plant location is also a problem.
Plants located near ocean shorelines experience corrosion
problems caused by the salt-water mist. Corrosion problems
are usually solved by finding the right disc material such as
nickel or stainless steel, or by coating the disc with a
material such as teflon.
• Disc leakage. Leaks are caused by pin-holes and irregularities
already present in the disc, or result from improper handling
by plant personnel. The first cause is a function of cost.
The more a plant is willing to pay for a disc, the more the
manufacturer will test and guarantee their disc. Although
even with the most expensive discs, there is always the possi-
bility of a poor quality disc in a batch. Most plants maintain
a rigorous inspection program for discs prior to installation.
A potential stress problem that results in a leak can also be
detected by gauging the space between the rupture disc and
relief valve for pressure - many plants currently follow this
practice even though it is not required by the regulation.
The other cause of failure, poor handling, is minimized by
instituting good maintenance and installation procedures.
Failure of rupture discs from most of the above causes can be reduced by
following a good quality control program. Many plants have found it
necessary to bring in a representative from the rupture disc manufacturer
to train plant personnel in proper handling and installation procedures.
In most cases this has eliminated failure of rupture discs. An example
of Conoco's testing/maintenance program includes the following
(Ledvina, 1980):
• The rupture disc is assembled in the shop between two flanges
prior to installation below the relief valve on a reactor or
other piece of equipment. This allows the disc to be pre-torqued
in a safety head device and reduces handing during installation.
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• After installation and before the equipment is put in service,
discs are hydrostatically tested to insure reliability. The
discs are tested up to 90 percent of burst pressure after
installation. (Reactors are pressurized above normal operating
pressure before charging).
• Upon receipt of a disc shipment a percentage of each lot is
randomly selected and pressure checked for quality and actual
pressure. The lot is rejected or accepted by this procedure.
• Discs are changed every 6 months and those removed are
tested to verify actual rupture pressure.
• Relief valves are replaced every twelve months.
t Emergency procedures involving non-reactor and reactor discharges
are updated once every year.
• The rupture disc manufacturer's representative visits the
plant each year for retraining purposes.
Failure of level controls. Slip gauges, which have a probe that
moves through the gas/liquid interface in storage or transfer vessels
indicating the level in the vessel by the physical state of the material
discharged, have been replaced with more sophisticated level controllers.
The new level controllers are used on charge tanks, storage spheres and
tanks, rail cars, tank cars and marine transport vessels, all of which
are under pressure and have some type of safety relief valve. However,
the new level controllers are not always reliable and inaccurate readings
on these controllers can cause an overpressurized condition during the
filling operation resulting in a relief valve discharge.
Many times these discharges are significant. One plant released
approximately 17,200 kg (38,000 pounds) of liquid VC from a storage
sphere during barge unloading (Battye, 1978). This was a combination
operator error and level control failure. Most of the discharges are
much lower and usually involve operator error caused by inattentiveness
during the filling operation.
High pressure in transfer lines and equipment. An overpressurization
can develop in the transfer lines during transfer of VC from storage
areas to process units. The pressure surge (hydraulic hammer) may be
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caused by closing a valve too quickly and can be prevented by manually
closing the valve slowly or instrumenting the valve to close slowly.
This condition can also be prevented by installing an emergency
high-pressure trip-switch or using a small, in-line surge vessel
(Brittain, 1980a). The high-pressure-sensitive switches can be used to
prevent relief valve discharges from other equipment such as recovery
compressors. The compressor automatically shuts off when overpressured,
a condition usually caused by clogging of the compressor lines
(Moulthrop, 1980).
Other causes of non-reactor discharges. Cold weather can be a
cause for non-reactor discharges. For example, one plant had an automatic
valve (to the VC reclaim vent) freeze shut causing the secondary decant
tank to overpressurize which caused a rupture disc to burst
(Battye, 1978).
4.3 RESIN STRIPPING
4.3.1 Introduction
Because one of the greatest sources of emissions is from those
points downstream of the resin stripper, the effectiveness of the polymer
stripping process is of prime importance in controlling emissions of RVC
lost to the atmosphere. The release of unreacted VC from the polymer
resin in the stripper is a function of time, temperature, and pressure
of the stripping process, in addition to particle size distribution and
porosity of the resin.
Prior to the current VC standard, stripping was done by PVC manu-
facturers for economic reasons; i.e., recovery of VC for reuse in the
process. Reduction of RVC concentration in the resin to meet regulated
emission levels now represents a primary reason for stripping to lower
levels.
In PVC plants using stripping technology to control vinyl chloride
emissions, the daily weighted average of the residual VC (RVC) concen-
tration in the stripped resin must meet the following limits as required
by Section 61.64(e)(l):
• 2,000 ppm for dispersion resins (excluding latex).
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t 400 ppm for all other resins (including latex) averaged
separately for each type of resin. Included in this category
are suspension, bulk and solution resins.
The prescribed emission levels are assigned without regard to
grades of the resin types although different grades of resin have unique
characteristics with respect to stripping efficiencies. Determination
of the RVC concentration is to be made by sampling immediately after the
stripping process and using a prescribed method (EPA Method 107). The
quantity of materials processed by each stripper is determined on a dry
solids basis. If batch stripping is used, one representative sample of
PVC resin is taken from each batch of each grade resin. If continuous
stripping is used, one representative sample of PVC resin is taken for
each grade of resin processed or at 8 hour intervals. Results of the
RVC analyses are submitted in the semi-annual report required from each
processor regulated by the standard.
Variables that affect stripping levels are: batch vs. continuous
stripping, homopolymer vs. copolymer resins, and reactor vs. non-reactor
stripping. Molecular weight and porosity of the resins influence
stripping rates. Stripping VC from PVC resin involves (Ullrich, 1981):
• VC migration to resin particle surface,
• VC dissolution in slurry liquid, and
0 VC vaporization and evacuation.
The first step is rate controlling. Suspension resin particles are
porous while dispersion and latex resin particles are not. Dispersion
particles are smaller than suspension, and latex smaller than dispersion.
For suspension resin, particle porosity enhances migration and allows
stripping below the 400 parts per million (ppm) residual vinyl chloride
(RVC) standard. For latex resin, the short migration distance allows
stripping below the 400 ppm RVC standard. For dispersion resin, the
longer migration distance and the particle non-porosity, in addition to
thermal and mechanical stress sensitivity, make stripping more difficult.
Each of these determines resin stripping methodologies.
Lower stripping levels, required by the standard, sometimes result
in the resin being excessively exposed to high temperatures that adversely
affect the resin's heat history. This heat history is a critical parameter
for the fabricator.
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Table 4-11 shows comparative stripping levels reported by PVC
plants producing various resin types and using different stripping
methods.
4.3.2 Suspension Resin Stripping
Of the 40 operating PVC plants in the United States, 32 of these
use the suspension polymerization process. (See Section 3.3.4 for a
process description.) These resins are homopolymers and copolymers and
are stripped batchwise or continuously, in the reactor or in a separate
vessel. Suspension resins have many grades with variable heat and
shear-stress tolerances.
One continuous stripping system for suspension resins has been
developed by B. F. Goodrich and is widely used throughout the industry.
In this process a pressurized stripping column feed tank is used to
release excess VC. This tank forms a transition from the batch reactor
to the continuous, multi-stage stripping column. The hot slurry is
pumped continuously from the feed tank to the stripping column through a
vapor liquid separator. The liquid slurry enters the top of a counter-
current steam stripping column and the vapor streams from the feed tank
separator and column are sent to the VC recovery system. The system can
be designed to handle porous or non-porous slurry feed with RVC content
ranging from 5,000 to 200,000 ppm. This process uses high temperatures
80° - 90°C (180° - 190°F) and a short residence time (Varner, 1980).
Levels attained in this process are often less than 10 ppm RVC in the
stripped slurry. Disadvantages of continuous column stripping are
(Fannin, 1981):
• Decreased scheduling flexibility. Processors requiring frequent
changes in batch sizes and/or recipe modifications cannot use
column stripping efficiently.
• Difficulty in cleaning column. Due to the column's shape,
internal cleaning is not as convenient as in an open vessel.
• Increased potential for burned particles. Crevices within the
column, resulting from the contact of trays and relatively
greater number of joints, tend to retain resin particles.
This results in a long exposure to heat and consequent burned
particles.
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Table 4-11. PERCENT DISTRIBUTION OF STRIPPING LEVELS
BEING ACHIEVED BY INDUSTRY*
Suspension
Plant
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Method0
c
b
c
c
b
b
b
c
c
c
b
b
b
Concentration of residual vinyl chloride
in ppm
b
Range of
dally average
(ppm)
High
123
1,629
388
303
576
634
631
382
1,214
1,385
541
514
684
1,099
1,056
Low
0.5
0.4
3
19
3
5
8
16
4
22
70
51
63
71
96
400
100
98.8
100
100
96.8
98.3
98.4
100
81.8
82.5
92.7
93.2
95.0
93.8
75.9
350
100
98.8
99.4
100
96.8
95.7
95.9
98.3
75.5
74.6
90.2
85.7
90.8
86.9
60.3
300
100
98.8
98.9
99.4
95.5
89.7
87.7
94.5
67.8
65.8
78.0
72.9
80.9
81.8
46.6
250
100
98.3
97.7
97.6
94.2
84.5
81.1
89.5
58.7
58.8
63.4
59.4
63.8
68.7
37.9
200
100
98.3
96.0
93.9
91.6
75.9
68.0
72.9
46.2
50.0
41.5
37.6
41.1
51.1
20.7
150
100
96.5
89.3
89.0
80.6
61.2
50.8
47.5
40.6
35.1
26.8
21.8
20.6
15.9
6.9
100
99.3
95.9
80.2
72.6
54.8
45.7
29.5
24.9
35.0
17.5
14.6
9.8
6.4
2.8
0
50
97.3
89.0
42.9
27.4
30.3
19.0
11.5
3.3
30.1
1.8
0
0.8
0
0
0
Bulk
1
2
3
b
b
b
166
293
672
12
3
56
100
100
84.3
100
100
77.7
100
100
58.1
100
99.3
46.4
100
99.3
25.1
99.4
97.9
8.9
97.5
95.2
1.1
78.3
84.9
0
Latex
1
2
b
b
15
310
0.2
8
100
100
100
100
100
99.4
100
99.4
100
98.3
100
96.9
100
74.5
100
24.2
aBased on EPA semi-annual reports for March through September 1980 obtained
from Regional EPA offices. Data represents approximately 50% of suspension,
75% of bulk, and 33% of latex plants.
blndividual data are percentages of time that concentration falls below
specified levels. Values represent daily averages weighted on a production
basis.
cMethod: b * batch; c « continuous
(continuedl
4-55
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Table 4-11 (Concluded)
Dispersion Concentration of residual vinyl chloride in ppm
Range of
daily average
(ppm)
Plant
1
2
3
4
5
6
7
Method1"
b
c
b
b
b
b
c
High
1,245
1.949
2,364
5,515
14,092
4.129
6,066
Low
15
132
418
49
297
89
644
2000
100
100
99.4
85.6
80.3
83.8
70.7
1900
100
99.3
96.6
83.5
78.0
80.2
62.6
1800
100
93.7
92.2
81.4
76.4
78.4
58.5
1700
100
90.9
87.2
79.4
76.4
74.3
55.3
1600
100
84.6
82.7
76.3
74.0
71.3
45.5
1500
100
79.0
70.9
73.7
72.4
67.1
37.4
1400
100
71.3
62.0
73.2
71.7
64.1
26.0
1300
100
61.5
50.8
68.6
68.5
56.9
22.8
1200
99.4
54.5
43.0
65.0
66.1
52.7
14.6
1100
98.8
42.7
33.5
61.3
59.1
45.5
10.6
1000
98.8
39.9
27.4
55.2
51.2
39.5
8.9
900
98.8
32.2
21.2
51.5
37.8
31.1
7.3
800
98.2
20.3
11.2
45.9
23.6
24.0
4.1
700
97.6
19.5
8.4
36.6
15.0
16.2
0.8
600
97.6
14.0
3.9
28.4
7.9
10.2
0
500
95.8
9.1
1.7
18.6
3.1
7.8
0
400
89.3
6.3
0
9.3
1.6
4.2
0
300
75.0
2.8
0
5.1
0.8
2.4
0
200
38.1
1.4
0
2.1
0
0.6
0
100
9.5
0
0
0.5
0
0
0
CD u
aBased on EPA semi-annual reports for March through September 1980 obtained from Regional EPA offices. Data represents approximately 40% of
dispersion plants.
Individual data are percentages of time that concentration falls below specified levels. Values represent daily averages weighted on a
production basis.
cMethod: b = batch; c = continuous
-------
• Mechanical stress. Because of the pumping system used in
continuous stripping columns, mechanical stress is imposed on
the slurry. For resins with a high sensitivity to this stress,
the particles can agglomerate resulting in poor uniformity and
an increased tendency for those particles to be retained and
burned. An extreme of this situation can be equipment fouling
(i.e., plugging of filters, screens, and orifices).
• Complex process control. Continuous stripping columns must be
fed at a rate controlled to maintain certain target temperatures
and pressures. There are more variables to be controlled
simultaneously than in an open vessel.
Continuous steam stripping represents the most widely used method
for suspension resins. Many of the processors using this technology are
achieving less than 400 ppm stripping levels ranging as low as 25 ppm
RVC (Pucci, 1980). One plant using a steam stripping method, but stripping
batchwise, reports typical daily averages of 200 - 250 ppm RVC (Laundrie,
1980). Reportedly, this plant is unable to use continuous stripping due
to the many (17) different grades of resins produced. Generally speaking,
those plants attaining the lowest RVC levels have chosen to produce one
or two resin grades with heat and shear stresses compatible with their
continuous stripping technology. In some cases "specialty" has been
sacrificed for increased production capacity.
Firestone Corporation continuously strips suspension resins to
levels less than 100 ppm RVC using their own proprietary technology.
This system uses less steam than other known counter-current continuous
strippers and may be marketed in the future (Schaul, 1980).
4.3.3 Emulsion Resin Stripping
About half (21) of the PVC plants have dispersion polymerization
facilities. Of these, 6 are latex resin processes. Dispersion resins
are more sensitive to heat and shear stress than are suspension resins.
Latexes are susceptible to these stresses and when exposed to shear the
emulsion can degrade into an unstable latex with a poor heat transfer
property. (See Section 3.3.5.1 for Emulsion Resin Stripping Process
description.)
4-57
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Dispersion resin slurry is usually either vacuum stripped in the
reactor or transferred to a separate vessel (blowdown tank) where it is
steam sparged. Due to their thermal instability, dispersion resins are
most often batch stripped under vacuum. Inert-gas sparging is sometimes
used instead of steam when dilution of the emulsion has to be avoided.
At least one manufacturer (B. F. Goodrich) does use a continuous
stripping procedure for its dispersion resins. The process was developed
by the company specifically for one of its dispersion facilities
(Holbrook, 1980c).
Daily averages of stripping levels for dispersion resins have been
reported as low as 15 ppm for one plant (Gilmore, 1980). Typical RVC
levels for dispersion resins in comparison to other resins are shown in
Table 4-11.
4.3.4 Bulk (Mass) Resin Stripping
Four of the forty PVC manufacturing plants produce bulk resins.
Characteristics of bulk resins resemble those of suspension resins but
the bulk resin beads are more uniform in porosity and size. These
characteristics enhance stripping efficiency. Three of the bulk poly-
merization plants surveyed strip in the reactor using steam stripping
technologies. In bulk resin stripping processes, steam must be injected
under a vacuum to avoid contaminating the process with water because
bulk polymerization is a dry process. One plant reports achieving daily
emission levels of less than 150 ppm RVC and another, less than 250 ppm
RVC.
Because the bulk polymerization process is anhydrous there are no
dryer emissions. However, those emission downstream of the stripping
process are still governed by the level of RVC removal during stripping.
4.3.5 Solution (Solvent) Resin Stripping
Only one plant produces PVC by the solution process. This plant
operates a process for the copolymerization of vinyl chloride with vinyl
acetate and other comonomers. The solvent process is unique, from the
standpoint of stripping procedures, in that no particulate resin form
exists and thus stripping can be accomplished by distillation. The
efficiency of the distillation process results in average levels of
10 ppm RVC or less on a consistent basis.
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The stripper still operates on a conventional distillation principle
using acetone and acetone vapors. The column is fitted with perforated
trays designed to accommodate the viscous resin solution.
This company is seeking approval for a less rigorous (and less
costly) sampling/analysis plan to assure compliance (Erdman, 1980).
4.3.6 Other Stripping Technologies
A short-residence-time device, adaptable to continuous processing,
is a proprietary thin-film evaporator. This device is reported to
exhibit diffusivities of 1,000 to 10,000 times greater than those for
simple molecular diffusion. In this system, heat is transferred through
a metallic wall to a thin film of liquid. A mechanical agitator dis-
tributes the liquid evenly over the heat-transfer surface. Disadvantages
of this device are: design criteria limits heat transfer area of each
unit, more maintenance is required than for a non-mechanical device, and
foaming may occur.
Another device, the Parkson stripper, is a non-mechanical, plate-type,
dispersed-flow contactor. The latex is dispersed into a controlled,
high velocity stream of steam and the resulting two phase flow passes
turbulently through a plate-type stripper. The stripped latex then
discharges into a cyclone separator, usually operated under vacuum, where
the latex is disengaged from the vapor. Multistage units may be used to
achieve desired residual monomer level. This unit is applicable to
foamy, heat-sensitive or viscous products. Its advantages are: complete
absence of foam, lack of moving parts, low holdup, low residence time,
and reduced surface fouling. The main disadvantage is that the plate
design permits only a limited capacity range.
One company's latex emulsion PVC facilities do not strip the resin
but instead uses a proprietary post-polymerizer. This involves the use
of a catalyst to react left-over VC. This process yields RVC levels
less than 10 ppm, which is a level mandated by the company's internal
standard for their particular product (Smith, 1980).
4.4 FUGITIVE EMISSIONS
4.4.1 Introduction
Fugitive emissions represent one of the most difficult emission
sources in EDC/VC and PVC plants to quantify and control. Most of the
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original fugitive emissions estimates were calculated by a mass balance.
For EDC/VC plants a mass balance calculation is less accurate because
several gas streams into and out of the plant are not measured accurately
(e.g., gaseous chlorine and ethylene feedstocks). PVC plant liquid and
solid streams are somewhat easier to measure and fugitive emission
estimates are more accurate. The accuracy of fugitive emissions estimates
is also affected by whether the plant is open or enclosed, and new or
old. An enclosed plant's fugitive emissions can be determined by using
roof monitors and ventilation flow rates through the building. Fugitive
emissions from an open plant are more difficult to measure because of
the variable wind patterns causing dispersion. The newer sources have
larger and fewer reactors and fewer piping connections which reduces
fugitive emissions. These variables must be considered when assessing
fugitive emissions losses from EDC/VC and PVC plants.
Based on a recent study done by B. F. Goodrich (Hoibrook, 1980a),
fugitive emissions from their enclosed existing small reactor suspension
and dispersion processes were determined (by actual measurement) to be
0.034 kg/100 kg of PVC produced or approximately 20 percent of the EPA
estimated controlled 1975 rate (de la Cruz, 1981). New large reactor
suspension processes were determined to be 0.0085 kg/100 kg of PVC
produced or only 5 percent of the EPA estimated controlled 1975 rate
(de la Cruz, 1981). This study was conducted following the implementation
of controls required by the current regulation and reflects the effect
of the regulation and new process technology on fugitive emissions
reduction. Sources of fugitive emissions in EDC/VC and PVC plants
include the following common equipment and operations:
• Pump; compressor and agitator seals,
• Loading, unloading and storage operation,
• Inprocess wastewater,
• Sampling and laboratory analysis,
• Equipment opening for cleaning and maintenance,
• Pipe and equipment flanges,
• Process drains and manhole cover seals,
• Process valves and pressure relief valves, and
4-60
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• Open-ended lines.
In order to reduce the fugitive emissions from the above sources,
Section 61.65(b) outlined the following three requirements for EDC/VC
and PVC plants:
• Equipment modifications,
• Operational procedures, and
• Leak detection and elimination programs.
These three requirements will be discussed in detail in the subsequent
sections.
In addition to the above three requirements for control of equipment
leaks, fugitive emissions that could originate from water used in the
various processes or water used to meet other requirements of the regu-
lation (e.g., reactor purging at PVC plants) are required to be controlled.
Control of these inprocess wastewater fugitive emissions will also be
discussed in a subsequent section.
EPA has published an advanced notice of proposed rulemaking for
generic standards for airborne carcinogens (44 FR 58662). These generic
standards would reduce fugitive emissions of organic chemical carcinogens
listed in the future under Section 112 of the CAA. The standards will
provide a quick and simplified first step in regulating chemical air
carcinogens by leak detection and repair programs.
The generic standards are independent of process or chemical and
are based on the similarity of operations and equipment throughout an
industry such as the Synthetic Organic Chemical Manufacturing
Industry (SOCMI). Depending on the nature of the listed organic chemical
and emission sources of this chemical, the generic standards may require
"tailoring" in certain cases to reflect unique and unusual situations.
Generic standards would be followed in most cases by additional standards
that would be developed under the proposed Policy and Procedures for
Airborne Carcinogens.
The draft generic standards need not be considered in any revision
to the VC NESHAP. The standards focus primarily on reducing fugitive
emissions through the use of an effective leak detection and repair
program. This type of program is similar to the programs currently
being used in the VC industry. In addition, EPA recently proposed
4-61
-------
regulations under Section 112 of the CAA that would limit benzene
emissions from fugitive sources in new and existing petroleum refineries
and organic chemical plants. The proposed regulation is similar in many
ways to requirements that the VC NESHAP outlined for prevention of
fugitive emissions (e.g., leak detection and repair program and equipment
specifications).
The following sections describe requirements of the regulation for
control of VC fugitive emissions. These sections also discuss new
developments resulting from the above draft generic standards and proposed
benzene regulations.
4.4.2 Equipment Specifications
Valves, pumps, flanges and other pieces of equipment are used to
move streams of liquid VC, PVC slurry, and VC-contaminated gases to and
from various process vessels or control devices. Equipment incorporating
sealed interfaces develop leaks after some period of operation, usually
because of seal failure. The regulation requires specifications for the
following equipment used in VC service:
• loading/unloading lines,
t slip gauges,
• pump seals,
• compressor seals, and
• agitator seals.
Double mechanical seals are required on rotating pumps, rotating compressors,
and agitators. Double mechanical seals are preferred over conventional
seals to provide the greatest reduction of fugitive emissions because
they have less leakage over a long service life. The inner and outer
mechanical seals of this system provide double seal protection from
leaks, where failure of either seal does not result in emissions to the
atmosphere.
Some plants are using tandem mechanical seals instead of double
mechanical seals for better product control. Typically, EDC/VC plants
are using tandem seals to prevent contamination of the VC product stream
by water. The double mechanical seal allows seal fluid to leak into the
product line while the tandem seal arrangement allows product to leak
4-62
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into the seal fluid. When water is used as sealing fluid, the water is
required to be collected and stripped to 10 ppm or less VC. Other
sealing fluids (e.g., oils) are not required to be collected and stripped
of VC contamination.
Regulations proposed for benzene fugitive emissions specify properties
of the seal or barrier fluid. The fluid must have a vapor pressure less
than 0.4 kPa (0.1 lb/in2) at 20°C (68°F) or it can be a heavy fluid such
as kerosene or diesel oil. No such requirement is specified by the VC
regulation.
Other equipment requirements are double outboard seals on
reciprocating pumps and compressors, and rupture discs upstream from
relief valves. The double outboard seals provide double protection
against leakage of emissions to the atmosphere. Relief valves can be a
continuous source of fugitive emissions especially those that do not
reseat properly after relieving pressure. Rupture discs installed under
the relief valve prevent this leakage if properly installed.
Slip gauges are no longer being used to measure the level of VC in
storage, holding, and transfer vessels. These gauges have been replaced
by more reliable level controllers that are not a source of fugitive
emissions. Loading and unloading lines have been modified in most cases
to reduce the VC remaining to required levels following purging and
prior to opening.
Section 61.65(b)(4) allows an equivalency to the rupture disc and
Section 61.66 allows equivalent equipment to be proposed other than that
required by the regulation. For example, instead of installing a rupture
disc, leakage through the relief valve can be eliminated by connecting
the discharge line from the relief valve to process equipment or the
recovery system. As mentioned in a previous section (Section 4.1.4),
one PVC plant has connected many of their safety relief valves on reactors
to a flare as an equivalency for a rupture disc. VC emissions from the
polymerization reactor leaking through the relief valve are combusted in
the flare. Table 4-12 lists equivalency determinations approved or
conditionally approved by the EPA since promulgation of the standard
(Brittain, 1980c; Legro, 1977).
4-63
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Table 4-12. APPROVED OR CONDITIONALLY APPROVED EQUIPMENT EQUIVALENCY DETERMINATIONS
Equipment Required
By Regulation
Equipment Equivalency
Request
Discussion
er»
Rupture discs under
all relief valves (RV)
(Section 61.65(b)(4))
1.
Double outboard seals
on all reciprocating
compressors (Section
61.65(b)(3)(iv))
1.
2.
Double mechanical
seals on rotating
compressors and
vacuum pumps (Section
61.65(b)(3)(i) and
(111))
RV's equipped with "0"
ring seat pressure
seals
Pressurized system —
the vent space between
the two seals is
pressurized with inert
gas
Packing rings in place
of seals
1. Liquid seals with
packing modified by
adding two "boxes"
placed over idle and
drive ends of unit
2. Labyrinth seals
1. Approved under following conditions:
• Ethylene propylene rubber (EPR) rings must be used
unless other material approved.
• Only can be used with RV having disc seat such that
no leaks occur during simmering.
• Must be maintenance program for replacement (per
year, each RV event and when leakage occurs).
• Maintenance program records (keep 2 years).
• Describe affected RV's prior to modification.
1. Volume between the inboard and outboard seals will be
pressurized with inert gas that will be continuously
purged to recovery and primary control device.
Leakage is into the compressor rather than to the
atmosphere and less maintenance is required.
2. Conditional approval if packing rings are vented at
low pressure to a control device. Venting at pressures
below atmosphere could lead to dilution with ambient
air. Pressure between seals must be specified and
flow rate monitored for leakage.
1. Conditional approval provided mechanical seal used
on drive shaft. Idle end will not penetrate "box"
which has a vapor tight seal. Drive end will have
similar "box" containing mechanical seal. Both
"boxes" are vented back into process at 1 psig to
reduce emissions.
2. Used on centrifugal compressors.
(continued)
-------
Table 4-12. Concluded
Equipment Required
By Regulation
Equipment Equivalency
Request
Discussion
en
Double outboard seals
on reciprocating
pumps (Section 61.65
Double mechanical
seals for horizontal
agitators (Section
61.65(b)(3)(v))
1. Reciprocating Hill-McCanna
Type K pump with seals,
shaft lubrication, regular
leakage inspections and
monitoring
2. Double packing pumps with
venting of water lubricant
to a control device
1. Pressurized grease system
This pump equipped with four separate layers of
packing material combined with a Merco Nardstrom
lubricator. A sealed pump must be used to
lubricate the stuffing box and lubricant levels
checked on regular basis. A VC monitoring point
must be close.
Water lubricant between the seals would be vented
to the wastewater stripper which controls VC
emissions to 10 ppm or less.
Would only be applicable to the bulk PVC process
which employs horizontal agitation.
-------
The "0" ring equivalency determination for rupture discs listed in
Table 4-12 can represent a reduction in emissions and equipment main-
tenance. In the normal operation of a relief valve without a rupture
disc, the relief valve seat (metal to metal seat) lifts off the nozzle
slightly as the operating pressure approaches the set pressure of the
relief valve, and the relief valve begins to "simmer." "Simmering"
occurs with fluctuations in operating pressures, but many times the
"simmering" does not cause the relief valve to fully open. The result
can be a misalignment of the relief valve seat and continuous leakage
when the operating perssure returns to normal. If properly installed
and maintained, the use of an "0" ring between the relief valve metal-
to-metal seat prevents the continual leakage from improper reseating.
The purpose of the relief valve/rupture disc combination was to eliminate
"simmering." If the rupture disc bursts, however, and the relief valve
does not reseat properly, then "simmering" will occur until the rupture
disc is replaced. The "0" ring does not completely eliminate "simmering"
if it is improperly installed or not maintained, but it will eliminate
the need to replace the rupture disc every time a relief valve opens.
4.4.3 Operational Procedures
The regulation requires EDC/VC and PVC plants to use the following
operational procedures to reduce fugitive emissions:
• Manual (non-emergency) venting of equipment. All gases vented
from equipment in VC service are to be ducted through a
control device which reduces emissions to 10 ppm or less.
• Opening of equipment (including loading and unloading lines).
Before opening equipment in VC service, the quantity of VC in
the equipment is to be reduced to no more than 2.0 percent by
3
volume or 0.0950 m (25 gallons) of VC, whichever is larger,
at standard temperature and pressure. The quantity of VC
removed in order to meet the requirement is then to be ducted
to a control device that reduces VC in the exhaust gases to 10
ppm or less.
• Sampling procedures. Unused samples containing at least 10
percent VC by weight are to be returned to the process and
sampling techniques should employ closed-loop systems.
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Requirements of this section of the regulation have been met through
modification of equipment that formerly discharged directly to the
atmosphere. In most cases, the vents from equipment subject to these
requirements have been enclosed and are ducted to the plant's VC
recovery system which is then ducted to the final control device to
reduce VC emissions to the atmosphere to 10 ppm or less. All routine
manual venting of equipment is to the recovery system. Most plants use
a positive-displacement unloading procedure and transfer lines are only
open to the atmosphere when maintenance is required. When disconnection
for maintenance is required, transfer lines are purged to the recovery
system. One plant has modified the unloading lines from rail cars so
that after purging the lines to recovery, the volume remaining in the
lines is less than the allowed volume of 0.0950 m (25 gallons)
(Laundrie, 1980). Plants surveyed during this study sample with
closed-loop systems and return unused sample to the process.
4.4.4 Leak Detection And Elimination Programs
The third requirement for reducing fugitive emissions from EDC/VC
and PVC plants is instituting and implementing a leak detection and
elimination program. As mentioned above, the major focus of the draft
generic standards is a leak detection and elimination program. The VC
sources were given the opportunity to develop their own program and
submit it to the responsible Regional office for approval. The regulation
listed the following six requirements for an adequate program:
• a reliable and accurate VC area or fixed monitoring system,
t a reliable and accurate portable hydrocarbon (HC) detector to
be used to pinpoint leaks indicated by the area monitoring
system and to make routine checks of the plant for small
leaks,
• an acceptable calibration and maintenance schedule for the
area monitoring system and the portable HC detector,
t an acceptable number and location of monitoring points and an
acceptable frequency of monitoring,
• an acceptable plan of action to be taken when a leak is detected,
and
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• a definition of a leak which is acceptable when compared with
the background concentration in the plant.
In addition, plants are required to maintain records for at least two
years. A record of leaks detected by the area monitors must include VC
concentrations measured and recorded, and the location, date, and time
of each measurement. A record of the leaks detected during routine
monitoring by the portable HC detector must also include action taken to
repair the leak in addition to the above same area monitor recordkeeping
requirements.
The intention of the fugitive emissions control requirements is to
first establish a background level of VC in the plant following instal-
lation of required equipment and implementation of operational procedures
described above. A leak definition would then be set based on the
plant's background level of fugitive emissions. The purpose of the leak
detection and elimination program would then be to monitor for leaks
based on the definition and eliminate these leaks over time, thus con-
tinuously lowering the background levels as well as fugitive emissions.
The background levels and leak definition would be reevaluated and
redefined as the fugitive emissions level decreased over time.
After any initial waiver period for compliance, a few of the EPA
Regions evaluated the adequacy of the leak detection and elimination
programs (Battye, 1978; Battye and Hall, 1978). Evaluations were also
made during these review study plant visits. These evaluations provide
the background for the following discussion of leak detection and
elimination program requirements.
Many inconsistencies were found among the plants because each plant
designed their own leak detection and elimination programs based on the
above six requirements for an adequate program. The site-specific
differences among the plants also contributed to inconsistencies. In
most cases the requirements were addressed adequately with minimal
changes recommended by the EPA Regions (e.g., number and location of
area sampling probes). However, other requirements such as leak defini-
tions, background concentrations and routine plant surveys were not
adequate in many cases. An example of the variability of the leak
detection and elimination programs among five plants is shown in
4-68
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Table 4-13. Each of the requirements for an adequate program are
discussed in more detail in the following subsections.
Leak definition.
A leak is defined on the basis of the plant's background concentration
of VC which not only varies among plants but may vary among different
areas of a plant. The background level for open plants or outdoor
equipment is usually set at zero. The regulation requires that the leak
concentration initially defined is to be reduced over time as background
concentrations in the plant are reduced. It is for these reasons that
leak definitions varied among plants and that one definition cannot be
applied to all plants. In most cases the leak definition was regarded
by the Regions to be adequate while in other cases the defined value was
too high.
A separate leak definition was usually identified for area monitors
versus portable monitors. Table 4-14 shows the range of leak definitions
for 12 PVC plants. As indicated by these leak definitions, there is a
great deal of variability. Many plants had not compiled data from which
to determine background levels, others had not defined a distance from
the leak for the portable monitoring leak definition and many plants
neglected the storage and handling areas completely.
Area monitoring system.
According to EPA Regional personnel an adequate area monitoring
system should accomplish four purposes:
• monitor processes for leaks,
• protect employees from occupational exposures (OSHA requirements),
• identify process conditions (e.g., start-up, shut-down, upset
conditions) that precipitate VC fugitive emissions, and
• provide background data base for relocation of sampling probes
and redefinition of leak.
The draft generic standards considered continuous area-wide monitoring
to measure ambient concentrations of hazardous chemicals, but found this
type of monitoring not as effective in locating leaks as a seal-by-seal
routine inspection. Any added effectiveness from area-wide monitoring
is minimal, plus it is a capital intensive technique. In the VC industry
4-69
-------
Table 4-13. LEAK DETECTION AND ELIMINATION PROGRAMS
^J
O
5
Type
of area
Plant monitor/
points
A Gas chromatograph
B Mi Han II Infrared
Analyzers
Six twelve-stream
units.
Total of 66 points.
r Mi Han 11 Infrared
Spectrometers
One six-stream unit
Two twelve-stream
units
Areas gas chroma-
tograph with FID
One six-stream unit
Total of 42 points.
Area
monitoring
sampling
interval
Each unit samples
one stream per
minute
Each unit samples
one stream per
mi nute
Samples one
stream per
mi nute
Action
level
for area
monitor
background party
concentration responsible
level for repair
25 ppm Two consecutive
readings greater
than 5 ppm
Foreman - non-
written
Area Three consecutive
Averages- readings greater
1 K nnm tha" Z5 PP"1'
I - b ppm
j! - 5 ppra Monitor print
c t , reading once per
Farm - b ppm u/eok
Foreman - written
(OSHA Work) 1st)
5 ppm One reading greater
than 25 ppft or four
consecutive readings
of 10 ppm above
background level.
Area monitor checked
every shift by
portable HC detection
operation.
Portable HC detector
operator - non-written.
Calibration
and
maintenance
schedules
Area monitor-
span checked
daily, GC's
calibrated
weekly;
equipment
checked
weekly,
annual tear-
down.
Portable-
calibrated
and checked
weekly.
Area monitor-
calibrated
daily with
10 ppm
standard.
Portable-
100 ppm
standard.
Area monitor-
calibrated
daily with
15.5 ppm
Standard.
Equipment
checked
weekly.
Portable-
calibrated
weekly.
Process Action
HdU- equipment level for
through check portable
program program H.C.
No program- None. 25 ppm
areas above
checked back-
dictated by ground
area level.
monitoring
system.
All areas
checked
occasionally
No program- No pro- N/A
weekly area gram,
checking as checked
directed by about
area once
monitoring every
system. two
weeks .
No program- None. N/A
areas
checked
three
shifts
daily as
directed
by
area
monitoring
system.
(continued)
-------
Table 4-13. Concluded
Type
of area
Plant monitor/
points
D EOCOM Fourier
Multiplex I.R.
spectrometer
sensitive to
less than 1 ppm.
Incorporates
microcomputer
(Indoor area).
Two Mirian I.R.
spectrometers
(Outdoor area).
Total of
47 points
c Three Areas 505
"• G.C.'s with
FID.
Total of
48 points
Area
monitoring
sampling
interval
EOCOM - non-cyclic,
may mix streams to
find a group with
highest ppm, then
breaks down this
group. Computes
statistical prob-
abili ty of an excur-
sion in a given area.
Can analyze a sample
in 20 seconds.
Mirian - continuous
monitor.
Each stream every
ten minutes.
One screen per
minute.
Action
level
for area
monitor
Response/
Background party
concentration responsible
level for repair
1-2 ppm 100 ppm concen-
tration over a
5 minute period.
Respond with
portable H.C.
checking.
Foreman
Less than Two consecutive
1.2 ppm readings greater
than 25 ppm for
area monitor.
Portable - 25
ppm reading.
Respond with
portable H.C. chuck.
Calibration
and
maintenance
schedules
EOCOM -
claims no
calibration
is needed.
Checked
twice daily
with
oscilloscope.
Portable
(Century)
calibrated
electronically
once daily.
G.C. checked
dai ly and
calibrated
twice a week
with three
different
standards.
Portable -
calibrated
weekly.
Walk-
through
program
Entire
plant
three
times
each
week.
Thorough
check of
reactors
daily;
other areas
checked
thoroughly
once per
month.
Data is
recorded.
Process
equipment
check
program
None.
Reactors
are checked
daily at
manifolds.
agitator
seals, rup-
ture disks.
manways ,
condensers
and piping.
Action
level for
portable
H.C.
N/A
Single
2.5 P(J,i.
reading
Operator - for
minor repairs;
shift foreman for
more extensive
problems.
-------
Table 4-14. VARIABILITY IN LEAK DEFINITIONS
Plants
A
B
C
D
-P»
-j
1X0 F
G
H
I
J
K
L
Area
Leak
Definition
(ppm)
3
>100
3
>5
>100
25
20-25
1
25
5
100
25
25
>5
Monitoring System
Consecutive
Readings (or
Persistent Time
Period)
2 (10 min.)
1
1
2
1
60 min.
1
1
2
2
5 min.
1
4
3
3
Background
Level
(ppm)
0.50
0.82
None
Determined
1
0.5
1.2
Confidential
1 to 2
5
1-10
0.5-5
Portable
Leak
Definition
(ppm)
>100
100
>50
50-300
>300
10
50
25
25
100
*
*
>5
Monitoring System
Inches From
Source (or Background
Persistent Level
Time Period) (ppm)
0.5
1 in. 0.82
6 in.
3 in. (30 min) None
Determined
3 in. 1
12 in. 0.5
1.2
Confidential
1 to 2
* *
* *
0.5-5
Storage
Leak
Definition
(ppm)
2500
5
>100
50
5
25
5
25
25
>5
and Handling Facilities
(Area Monitor)
Consecutive
Readings (or
Persistent Time
Period)
1
2
1
1
1
2
2
1
4
3
3
Background
Level
(ppm)
0.1
0
<0.5
1.2
Confidential
5
0.5-5
0.5-5
* Routine survey conducted only if area monitor printout indicates leaks.
-------
the leak detection and repair programs are based on area-wide monitoring
for ambient VC concentrations. The effectiveness of this monitoring is
discussed below.
The most important variable for an adequate area monitoring system
is the location of sampling probes. The number and location of sampling
probes for the area monitoring system will vary among plants -- this
requirement is too site-specific to set exact numbers and locations.
Many plants already had area monitors to protect work areas as required
by OSHA. As a result, this same system was utilized for EPA require-
ments and many probes were located in worker breathing zones instead of
fugitive emissions sources. OSHA probes were located where workers
spend most of their time, thus many areas (which have a potential for
fugitive emissions) are not monitored. Some plants completely neglected
storage and handling areas which can be a significant source of fugitive
emissions. For example, the area monitors are set at different concen-
tration levels which set off an alarm when this level is exceeded. Some
alarm levels were set only for personnel safety, which can be higher
than the leak definition for a particular plant, and the EPA leak defi-
nition level was neglected. In other cases where the alarm is set to
detect fugitive emissions, the alarm is set at a level higher than the
leak definition.
Many of the plants had insufficient background data to determine if
area sampling locations and background levels set were adequate. Some
plants determine how often an alarm is sounded for a particular
concentration in different areas of the plant over time and relocate
sample probes based on these alarm frequencies. In some cases, background
levels, as well as leak definitions, may vary in different areas of a
plant. Some plants have located area probes close to exhaust fans and
equipment near air ventilation intake fans. The probe near an exhaust
fan responds to all leaks but there is a dilution effect, while the
probe near the intake fan does not respond at all. A compromise between
these two locations based on air flow patterns through enclosed buildings
results in the proper placement of probes. The sampling location near
an exhaust fan has been used in some cases to provide data for revaluation
4-73
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of the program because VC concentrations at this point should decrease
with time.
Area sampling lines in some cases are manifolded to two or more
sampling probes. The result is that a localized leak near one probe
will often be diluted by air from other probes and thus, the leak will
not be detected until the concentration is higher than the actual leak
definition. Also, there is no way to determine if one probe becomes
clogged or broken unless sample line integrity is checked on a regular
basis. Probes close to reactors can be easily broken by reactor vibrations.
Particle filters or metal shields on outdoor probes help to provide
protection from probe and sample contamination and breakage.
Continuous air purging of probes and sample lines is recommended to
ensure that the concentration recorded is indicative of the current
reading. Also, gases used to calibrate the area monitor provide more
representative results when injected at the sampling probe. In a recent
study (EPA 1980) done in support of the proposed standard for benzene
fugitive emissions, these recommendations were followed. Calibration
gases were injected directly into the sample probe to evaluate the
response of the area-wide monitor. Results of the calibration are
indicated in Table 4-15. The concentrations measured by the area-wide
monitor were much lower than the actual concentrations of the calibration
gases. The gases were adsorbed to the inner walls of the sampling lines
because concentrations continued to increase and then slowly decreased
as the gases were desorbed from the sampling line inner walls.
Another important aspect of the area monitoring system is the time
interval used to cycle all sampling points. Most plants use more than
one instrument and usually each instrument has 10 to 16 sampling streams.
Analysis of a sample collected by a stream takes about 1 minute (20 to
90 second range), thus each stream is monitored once every 10 to 16
minutes. However, some plants have different systems, whereby cycle
time selection is more elaborate. For example, one plant that produces
other chemicals in addition to VC, uses a halogen analyzer and gas
chromotograph which chose the point to be analyzed based on four classes
of information collected - a halogen alarm level sounded, maximum time
4-74
-------
Table 4-15. CALIBRATION RESULTS FOR AREA-WIDE MONITOR
Calibration
gases
Benzene
Toluene
(para)xylene
(ortho)xylene
Vendor analysis
(ppm)
5.37
54.30
28.10
22.00
Laboratory analysis
(ppm)
Sample 1
5.00
53.00
48.00*
Sample 2
6.00
52.00
45.00*
Area-wide monitor
reading (ppm)
Probe 1 Probe 2
0.04 0.00
18.16 44.39
21.29* 19.40*
>
The laboratory analysis and area-wide monitor measured total xylene.
-------
for a cycle, any alarm level sounded, and if no alarm level is sounded
(this is the most frequent choice of system and results in a sample once
every 40 to 50 minutes). The maximum sampling time between each point
is 1.5 to 3.0 hours with all points monitored at least eight times every
24 hours.
Another plant does not cyclically monitor but instead uses a micro-
processor that computes statistically the probability of an excursion
over the leak definition in each sampling area and selects the area most
likely to be near an excursion. This selection is based on historical
data and time elapsed since last analysis. This system also mixes
streams to save time and if after mixing the VC concentration is high,
the instrument immediately analyzes each stream separately. An operator
can also select a stream to see if an excursion has been corrected and
review an hourly printout showing time weighted concentration averages.
Plants surveyed use one or more of the following area monitoring
systems:
• Areas 505 gas chromatograph with flame ionization
detection (FID),
• Bendix 6000 series gas chromatograph with FID,
• EOCOM Fourier multiplex infrared spectrometer (FMS-7200) with
minicomputer, and
• Miran II Infrared Analyzers with infrared spectrophotometry.
The gas chromatographs use columns to separate the VC from other compounds.
The FMS-7200 uses two wavelength bands and is therefore more specific
for VC. Sensitivity of the FMS-7200 is less than 1 ppm. The Miran II
is not as specific or accurate for VC and is usually used to monitor
outdoor equipment only. There are other Miran instruments that are more
appropriate for indoor monitoring.
Routine surveys with portable detector.
As mentioned above, the draft generic standards emphasize routine
leak detection surveys with a portable monitor over area-wide monitors,
or a combination of the two. The VC industry uses a combination of
routine surveys and area-wide monitors. The portable hydrocarbon (HC)
detector is used to immediately identify the leaking equipment source
4-76
-------
when an area alarm is sounded and to conduct leak surveys throughout the
plant on a regular schedule. The following portable HC detectors were
used by the plants surveyed:
• Century Systems Organic Vapor Analyzer (OVA) - the instrument
measures total HC by flame ionization.
• H Nu Systems Photoionization Detector (Model P1101) - the
instrument has three concentration ranges for total HC.
Some plants favor one of these portable meters over the other or use
both, one as primary and one as back-up; both are regarded as adequate
for leak detection.
The routine surveys that are required to be conducted on a regular
basis probably represented the least consistent area in the leak detection
and elimination programs reviewed. The schedule for routine portable
monitoring, other than following up an area monitor alarm, varied among
the plants -- from a once per shift basis to a weekly or monthly basis
or no regular schedule at all. In some cases, the routine survey was
conducted on a regular basis and in other cases, on an irregular basis
depending on area monitoring print-outs for a particular shift or day.
For PVC plants, the most thorough routine programs consisted of monitoring
the reactor daily and other equipment and areas of the plant on a weekly,
monthly, or quarterly basis. Usually the weekly, monthly, or quarterly
frequencies in most cases are determined by historical data and type of
equipment service.
Routine leak surveys usually follow an equipment checklist so that
the same pieces of equipment are consistently monitored. This not only
provides consistency, but also identifies those pieces of equipment that
chronically leak and may require more frequent monitoring.
Instrument calibration and maintenance.
Most plants surveyed follow the instrument manufacturer's recommended
calibration and maintenance procedures. Standard gases were usually
used for instrument calibration and the concentration of these gases was
in most cases close to the leak definition. Some plants calibrated
portable monitors with a Wheatstone bridge which only provides a check
on the internal electronics. As mentioned above for the area monitors,
4-77
-------
calibration gases injected at the sample-probe location provided the
best method for calibration as opposed to injecting the gas directly
into the instrument. Also, there can be interference if other chemicals
are being produced at a facility. This should be taken into consideration
when developing a calibration and maintenance procedure as well as when
locating area sampling probes and conducting routine leak surveys.
Plan of action when leak detected.
In most cases, when an alarm is sounded by the area monitoring
system, the following actions are usually activated:
• a leak search is initiated with a portable monitor in that
area of the plant,
• the leaking piece of equipment is identified, and
• the leak is eliminated.
There is some variation in procedures taken once the leak is identified,
but most plants follow similar actions for elimination based on the
severity of the leak. Some leaks can be stopped immediately by turning
a valve or tightening a flange or the leak may be severe enough to cause
immediate equipment decommissioning, which requires that the equipment
be immediately put on recovery and shut down at the earliest and safest
time. The leak may also be somewhere between these two extremes, in
which case the leaking equipment can be enclosed and ducted out of the
building until the maintenance personnel can repair the leaking equipment.
In all cases, it is important that an accurate log be kept on the
leaking equipment - date, time, location, cause of leak, quantity of
emissions (if possible), corrective action taken, and time until repair.
Shift supervisors are usually made responsible for seeing that the leak
is properly eliminated. The equipment usually is monitored again imme-
diately after repair to verify repair and elimination of the leak. An
accurate record of these leak abatement steps is not only required but
also identifies those pieces of equipment that chronically leak and may
require more frequent monitoring.
Recordkeepinq requirements.
As mentioned previously, detailed records are to be maintained at
the facility for at least two years. These data are maintained for
4-78
-------
review by EPA personnel during inspections - no records on fugitive
emissions are required to be submitted to EPA. Only the original proposed
program was to be submitted for approval. Some plants maintain records
for their own benefit that are not required by the regulation, such as
the number of times a specific area alarm is activated or identification
of equipment leaking below the leak definition. These extra data, in
conjunction with required data, can be used to determine trends - the
number of leaks found as a function of time or the background levels as
a function of time. This information can then be evaluated periodically
to identify problem areas and seek ways to eliminate the problems (e.g.,
replace chronically leaking equipment with new or different equipment).
The information can also be used periodically to improve the program and
reevaluate the leak definition.
Adequate leak detection and elimination programs.
EPA Region VI, which is responsible for the majority of subject
sources, evaluated the programs submitted and based on these evaluations
and follow-up inspections, determined the following minimum requirements
for an acceptable program (Ramirez, 1978):
• A sufficient number of sampling points must be utilized to
detect a leak no matter which direction the wind is blowing.
• A leak patrol must survey the entire plant at least once a
week.
t An accuracy test of the leak detection system should be
conducted by introducing a known concentration of VC into a
sampling probe. The complete system should be checked once a
year and reported in the semi-annual report.
• The VC calibration gas cylinders should be analyzed when they
are received by utilizing Method 106.
• There must be an alarm system (visual or audio) to notify the
plant personnel of a leak. This alarm must continue until
acknowledged.
• There must be an instantaneous printout showing location and
concentration of leaks when they occur.
4-79
-------
• The evaluation of each company's background level will be made
on a case-by-case basis in order to evaluate their definition
of a leak.
• The portable hydrocarbon detector must be calibrated at least
once a week.
An additional important requirement is the development of a data base
for fugitive emissions through accurate recordkeeping. In some instances,
this recordkeeping may require additional data collection other than
that required by the regulation. The data base developed could then be
evaluated on a regular basis to reevaluate a plant's background level
and redefine the leak definition.
4.4.5 Inprocess Wastewater
Water used in the EDC/VC and PVC processes can become contaminated
with VC and be a source of secondary emissions if not contained and con-
trolled. Even though the above requirements of the regulation discussed
for fugitive emission control (equipment specifications, operational
procedures and leak detection and elimination programs) are not applicable
to inprocess wastewater, it is still categorized as a fugitive emissions
source. The regulation requires the concentration of VC in each waste-
water stream containing greater than 10 ppm VC measured immediately as
it leaves a piece of equipment, and before being mixed with other waste-
water, be reduced to 10 ppm VC or less. This concentration in the water
must be attained prior to mixing with other inprocess wastewaters con-
taining 10 ppm or less VC, before being discharged to a wastewater
treatment process or plant, or before being discharged untreated to a
body of water.
There are several sources of inprocess wastewater in EDC/VC and PVC
plants. In EDC/VC plants, water from EDC purification and VC cracking
and purification (as shown in Figure 3-1) and equipment seals is con-
taminated with VC at levels greater than 10 ppm. In PVC plants, VC-
contaminated inprocess wastewater is generated from the following sources:
• water used to evacuate reactors prior to opening in order to
meet reactor opening loss (ROL) requirements,
0 water used as sealing fluid for double mechanical seals on
pumps, compressors and agitators,
4-80
-------
• water removed by knock-out pots used in the monomer recovery
system, and.
• water used to seal gasholders.
Depending on the methods used to attain the ROL requirement (e.g., water
piston which is discussed in Section 4.5), large quantities of inprocess
wastewater can be generated.
Inprocess wastewater from ROL methods, seals, and knock-out pots is
usually collected in a vessel and then steam stripped of VC. Water used
to seal gasholders is in contact with VC-contaminated gases and by
definition is an inprocess wastewater. This water is always exposed to
the atmosphere without treatment. Actual VC concentrations of this seal
water were not available, but for one plant using a water-sealed gasholder,
emissions to the atmosphere from the seal were calculated to be
approximately 0.79 kilograms (1.75 pounds) per year (Battye, 1978).
Removal of VC dissolved in water is usually accomplished by a
distillation column. The water collected by fugitive emissions sources,
and usually held in a vessel prior to the column, is close to saturation.
Thus, separation in the stripping column is simple because the vapor
pressure of VC is much greater than water.
4.5 REACTOR OPENING LOSS
4.5.1 Introduction
The VC emissions resulting from venting a polymerization reactor to
the atmosphere (other than an emergency relief discharge as defined in
Section 61.65(a)) constitute reactor opening loss (ROL). The ROL standard
is only applicable to PVC plants. These emissions are regulated under
Section 61.64(a)(2) and are limited to 0.02 grams VC per kilogram PVC
produced (on a dry solids basis). This regulation applies to any vessel
used as a reactor or as both a reactor and a stripper.
Determination of ROL emission levels is made by actual sampling and
analysis of VC levels at the bottom, middle, and top of the reactor
(methodology specified in the standard). A calculation option is pri-
marily used by processors stripping in the reactor and is based on
number of evacuations, vacuum applied, and volume of gas. The calcu-
lation (if approved) represents a waiver from testing, not an equivalent
4-81
-------
method of ROL determination. When the reactor serves as the stripping
vessel, the resin (after stripping is completed) contributes VC to the
headspace concentration and consequently to the ROL measurement. Reporting
of ROL emission levels is made in the semi-annual report submitted by
regulated facilities to Regional EPA offices. (See Table 4-16 for
representative reported ROL levels).
To maintain product quality, reactors are opened for maintenance or
inspection and for removal of residual polymer adhering to reactor
walls. The frequency of openings is a function of resin types and
grades, reactor size and construction, location and method of the
stripping process, and effectiveness of reactor cleaning methods.
ROL emissions control can be achieved through various technologies
and process modifications. Basically, the objective is to:
• minimize the amount of VC in the gas phase prior to opening,
and/or
• maximize the total PVC production per reactor opening.
Reducing the amount of gaseous VC can be accomplished by evacuation to a
low absolute pressure, by displacement with water or an inert gas, by
steaming, or by a combination of these. Increasing total PVC production
may be achieved by reducing reactor opening frequency. (This also has
the advantages of reducing turn around time and minimizing employee
exposure to VC). Technologies available for controlling ROL emissions
have been developed by the various plants to suit their individual
processes. The method identified in the original standard support
document, water piston, is not applicable to all processes (EPA, 1975).
The water piston method as well as other methods are discussed below.
4.5.2 Solvent Cleaning
Solvent cleaning systems reduce the number of times a reactor has
to be opened for cleaning. The solvent, circulated through the reactor,
dissolves the solid scale present on the reactor walls, eliminating the
need for manual scraping. Several solvents, suitable for reactor cleaning,
have been tried by PVC processors. These include di-methylformanride
(DMF), tetrahydrofuran (THF) and dichloroethane. However, there are
serious disadvantages to the use of these solvents for reactor cleaning.
These include:
4-82
-------
Table 4-16. REACTOR OPENING LOSS REPORTED BY REPRESENTATIVE COMPANIES
(Data from September 1980 Semi-Annual Reports)
Company
(code)
A
B
C
D
E
F
G
H
I
J
Resin
type
suspen.
suspen.
suspen.
suspen.
disper.
dlsper.
disper.
bulk
bulk
latex
Number of
openings
72
47
757
215
60
766
5668
1340
Number out of
compl 1 ance
2
1
2
0
2
0
0
18
0
0
Compliance
rate
97.2%
97.9%
99.7%
100%
96.7%
100%
100%
99.7%
100%
100%
Concentration
calculated
or actual
actual
calculation
actual
actual
calculation
Control
technology
Water Piston (Displacement)
Steam Sweep Technology
Solvent Cleaning/Closed Charge Technology
Steam Injection
Steam Sweep Technology
Redox Catalysis
CO
CO
-------
• The expense of the solvents. THF is approximately $2.00 per
liter ($7.00 per gallon). One plant experimenting with this
chemical for ROL reduction lost 76,000 to 114,000 liters
(20,000 to 30,000 gallons) of solvent per month through the
process. This represents a loss of up to $210,000 per month.
• The creation of secondary sources of pollution (solvents
appropriate for reactor cleaning pose environmental and work-
place hazards).
• The requirement for energy-intensive stripping operations to
remove PVC from the solvent so that the solvent can be reused.
• The hydrocarbons present due to solvent cleaning may require
that ROL be measured by Method 106 to demonstrate compliance,
or that many more batches be produced between reactor opening.
This is because the hydrocarbon detector (alternative to using
Method 106) will measure these hydrocarbons along with VC
(Ullrich, 1981).
Nevertheless, a few processors using solvent cleaning are reporting low
ROL levels. A solvent cleaning process using DMF has been patented by
Air Products and Chemicals Incorporated and is probably available for
license. This process involves filling the reactor with solvent under
an inert atmosphere. The reactor is heated and stirred while a small
continuous flow of solvent overflows the reactor top. After sufficient
time elapses, the solvent is transferred to storage and the reactor is
rinsed several times with water. The reactor is then ready for another
polymerization cycle. Solvent regeneration includes precipitation of
solids, centrifuging to remove solids, and distillation to purify the
solvent.
4.5.3 Steam Piston
One PVC manufacturer surveyed uses this technology to control ROL
emissions for their suspension and dispersion reactors. The process
involves draining the reacted slurry from the reactor and placing a
puddle of water in the bottom of the reactor. A vacuum is pulled and
steam is applied to the vessel jacket. Under vacuum the water boils and
evaporates at low temperatures. The steam rises through the vessel in a
4-84
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"piston like" manner and is exhausted to the VC recovery system. This
technique has proven effective in reducing ROL emissions.
4.5.4 Water Piston
An application of this technology was noted in a PVC suspension
homopolymer plant and identified in the standard support document.
After the slurry is discharged to another vessel for stripping, the
reactor is hydraulically filled to the nozzles with water, displacing VC
vapors to recovery. Steam is applied to the jacket to heat the water in
the reactor and vacuum is pulled from the top of the reactor. The
vapors in the head space are exhausted to the recovery system by way of
a knock-out pot (Laundrie, 1980).
One problem encountered in this method is the generation of large
amounts of water contaminated with VC. Another consideration is the
type of polymer involved. Diffusion rates of VC out of the polymer are
not only temperature dependent but also depend on the resin character-
istics. If the jacket temperature is too high, polymer degradation can
proceed to the point where removal of polymer build-up is difficult
after the reactor is opened. Jacket temperatures that are not hot
enough result in decreased VC diffusion rates, thereby extending the
time required for adequate VC removal and increasing emissions when
opened.
4.5.5 Reactor Purge Air Blower
This technology is used by a suspension-polymerization plant
manufacturing homopolymer and copolymer resins. This facility strips
the slurry in the reactor. Prior to reactor opening, a purge air blower
sweeps the vapor space above the slurry. The blower discharges directly
to the incinerator. ROL compliance is then determined by calculation
(Schaul, 1980).
4.5.6 Steam Purge (Sweep)
This represents the most widely used technology for control of ROL
emissions. It involves the injection of live steam under vacuum, con-
densing the waste steam, and subsequent stripping of the water. Less VC
contaminated water is generated by this process. Parameters for this
process, reported by a suspension and dispersion resin plant, consist of
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a 15-minute purge under vacuum. This procedure has consistently
resulted in ROL emission levels well below the standard for this plant
(Battye, 1978, Vol. II, p. 30). Vacuum pressures and temperatures vary
from plant to plant depending on resin characteristics and process
variables.
One problem encountered by a plant using this steam sweep technology
involves leakage by shut-off valves back into the reactor, resulting in
ROL excursions. This has been attributed to scoring of the valves and
subsequent failure to reseal properly.
4.5.7 Redox Catalysis
One company, whose latex PVC facilities substitute a
post-polymerization process for resin stripping, eliminates ROL emissions
entirely. The method involves removing all equipment from VC service
prior to opening by using a caustic wash and pickle rinse. These rinses
are treated with a catalyst which scavanges unreacted VC and the rinses
are monitored for VC until they are shown to be below 10 ppm prior to
release to the sewer. The technology is proprietary (Ferrell, 1980).
4.5.8 Water Jet Cleaning
A procedure reported for suspension resin reactor cleaning - Hydraulic
Reactor Cleaning (HRC) - used 28,000 to 41,000 kPa (4,000 to 6,000 psi)
water in a water jet cleaning system with the water jet collar fitted
directly into the reactor manway. This equipment allowed 25 to 30
batches to be run between reactor openings instead of opening between
each batch. An identical system for dispersion resin reactors allowed 5
to 15 batches between openings. With some development expense, a spray
system of the type could be developed by any PVC producer. The HRC
technology described was developed by B. F. Goodrich and is probably
available for licensing.
4.5.9 Clean Reactor (Closed Cleaning) Technology
This technology encompasses a wide range of techniques used to keep
reactor walls free of deposits. Included are wall coatings, recipe
modifications and mechanical cleaning devices. In conjunction with
large reactor utilization, which allows more room for internal cleaning
devices, clean reactor technology affords abatement of emissions from
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other sources in addition to the ROL. High pressure spray systems and
nozzle designs (for removal of deposits) and formulations of dispersants,
catalysts and additives (for reduction of deposits) are incorporated in
this technology. These are patented and some are available for license.
4.5.10 Nitrogen Purge
Nitrogen, used to purge the reactor under a vacuum, is
non-condensable and therefore this method is not easily adaptable to
monomer recovery without increased expense. Primary applications of
this ROL emissions control method are in Pre-Po reactor preparation for
opening. The vacuum is broken three or four times with nitrogen - the
final break being made with air. The nitrogen gas, which contains
recovered monomer, is subsequently incinerated.
4.5.11 Slurry Backfill
One plant is known to use this method to control ROL emissions for
reactors used as strippers. The process involves dispersion resins
which are stripped in the reactor. Following polymerization, the slurry
is stripped under vacuum in the reactor vessel until the required resin
RVC level is attained. The reactor is then backfilled with previously
stripped slurry forcing headspace vapors out of the reactor to the
recovery system, and thus also eliminating the reactor headspace. No
further vacuum is applied because liquid slurry would be evacuated at
this point. The ROL requirement is met by this method because the
headspace vapors have been eliminated (Konter, 1980). A waiver of
testing requirements has been obtained from the Region. Resin RVC
emissions lost during transfer of the slurry to another vessel cannot
contribute to ROL emissions because these emissions would be considered
beyond the stripping operation and therefore not regulated (Section
The main advantage of the slurry backfill control technique for ROL
is the small amount of water used, eliminating the need for a large
VC-contaminated wastewater stripper. In addition to the pumps required
for backfilling, a level sensor is required to insure that the slurry is
not backed into the recovery system. This process would also appear to
be adaptable to suspension processes.
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4.5.12 Calculated Emissions
In processes where resin stripping takes place in a separate vessel,
the reactor is under pressure which allows the slurry to be evacuated
without opening the reactor. The methods described above can then be
applied prior to opening in order to attain the ROL standard. However,
when the reactor also serves as the stripping vessel, the vacuum (pulled
when the slurry is being stripped) must be broken prior to slurry dis-
charge and this constitutes a reportable reactor opening. The required
testing procedure for ROL can not be applied until the slurry is removed.
The slurry may contribute enough RVC so that the ROL standard is
unattainable and these measurements cannot be made until the reactor has
cooled.
The prescribed method for measuring ROL is impractical and unsafe
for those plants stripping in the reactor. If the probe measurement is
taken while the reactor is hot immediately after stripping, the high
vapor temperatures present a safety problem to the person making the
measurements. If the reactor is allowed to cool, this not only affects
productivity (because several hours are required for cooling) but also
results in measurements that are not representative.
When ROL measurements are made according to the present regulation,
the same VC is essentially "counted twice" (i.e., once in the resin and
once in the vapor space).
Through waivers of emission testing for reactor opening loss, PVC
plants whose stripping operations take place in the reactor, are con-
sidered to be in compliance with Section 61,64(a)(2) if the measured
reactor opening loss added to the measured resin RVC is less than the
sum of allowable ROL and the allowable resin RVC. For plants stripping
below the RVC standard, the processor is not penalized for that portion
of the RVC (removed by stripping) that contributes to the ROL. The ROL
levels are allowed to be higher when the reduced stripping emissions are
used as a credit.
The calculation may present a problem even though the results as
calculated are correct. The calculation will not include those emissions
from leaking valves or broken equipment that may contribute to ROL
emissions, but are only found by an actual test.
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It is the policy of some Regions, in keeping with the intent of the
standard, to grant waivers of testing to those processors in the above
category. These waivers are made on a case-by-case basis, and with the
provisions that RVC samples must be taken on each batch. A calculation
may then be used to establish ROL. Formulas developed for these calcu-
lations are generally treated as confidential by the plants using them
because the formulas are considered to be potentially marketable and
they can reveal some of the nature of the process. The basis for
the ROL calculation is Raoult's Law. The general requirements for using
calculated ROL's are:
(1) Calculations must be done for each grade of resin,
(2) Parameters such as number of times a vacuum is pulled, must
remain constant, and
(3) Tests must be confirmed by standard methods.
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4.6 REFERENCES FOR CHAPTER 4
Aronson, Wayne, J. 1980. Enforcement Division, EPA Region IV,
Atlanta, Georgia. Freedom of Information Request from J. W. Bodamer, Jr.,
TRW Environmental Engineering Division. October 1980.
Battye, William. 1978. GCA Corporation, Technology Division. "Technical
Assistance to Region III for Enforcement of Vinyl Chloride Regulations,"
Contract No. 68-01-4143, Task No. 35, Volumes I, II, III, V and VI.
December 1978.
Battye, William and Hall, Robert R. 1978. GCA Corporation, Technology
Division, "Technical Assistance to Region V for Evaluating Vinyl Chloride
Leak Detection and Elimination Programs," Contract No. 68-01-4143, Task
No. 16, Volumes I, III, V, VI and VII. July 1978.
Blacksmith, J.R., G.E. Harris, G.I. Langley. 1980. Radian Corporation,
"Frequency of Leak Occurrence for Fittings in Synthetic Organic Chemical
Plant Process Units," Contract No. 68-02-3171, Task No. 001.
September 1980.
Brittain, Martin. 1980(a). NESHAP Coordinator for EPA Region VI. Meeting
report - TRW visit to Region VI offices, Dallas. July 23, 1980.
Brittain, Martin. 1980(b). NESHAP Coordinator for EPA Region VI. Telecon
with J. W. Bodamer, Jr., TRW Environmental Engineering Division.
November 7, 1980.
Brittain, Martin E. 1980(c). Environmental Protection Agency, NESHAP
Coordinator, Region VI. Information supplied during meeting between
Region VI and TRW. July 1980.
Brumbaugh, Gerry. General Tire and Rubber Company. Telecon with
J. W. Bodamer, Jr., TRW Environmental Engineering Division.
November 14, 1980.
Chemical and Engineering News, 1978. "Key Polymers." September 4,
1978, p. 13.
Chemical and Engineering News, 1980(a). "Key Chemicals." July 7, 1980,
p. 9.
Chemical and Engineering News, 1980(b). "Key Polymers." October 6,
1980, p. 13.
DeBernardi, James. 1980. Plant Manager, Conoco Chemicals, Lake Charles,
Louisiana, EDC/VCM plant. Telecon with M. A. Cassidy, TRW Environmental
Engineering Division. November 18, 1980.
DeBernardi, James. 1981. Plant Manager, Conoco Chemicals, Lake Charles,
Louisiana, EDC/VCM plant. Telecon with M.A. Cassidy, TRW
Environmental Engineering Division. March 6, 1981.
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de la Cruz, Peter L., 1981. Assistant General Counsel to the Society of
Plastics Industry, Inc. Letter with attachments to Don R. Goodwin,
EPA. May 18, 1981.
Diem, Conrad. 1980. Special Enforcement Section, EPA Region III. Letter
to J. W. Bodamer, Jr., TRW. December 1980.
Dubec, Harold F. 1980. Manager of Environmental Compliance, Hooker
Chemical. Trip report - visit to Hooker Chemical Company, Ruco Division,
Burlington, New Jersey. September 1980.
Environmental Protection Agency. 1980. "Emission Test Report Benzene,
Fugitive Emissions - Petroleum Refineries," EMB Report No. 78-OCM-12B,
October 1980.
Environmental Protection Agency. "Proposed National Emission Standards
for Identifying, Assessing and Regulating Airborne Substances Posing a
Risk of Cancer," Federal Register/Volume 44, No. 197/Wednesday.
October 10, 1979.
Environmental Protection Agency. 1975. Standard Support and Environmental
Impact Statement: Emission Standard for Vinyl Chloride.EPA-450/2-75-009,
October 1975.
Erdmann, John F. 1980. Environmental Protection Coordinator,
Union Carbide. Telecon with J. W. Bodamer, Jr. , TRW Environmental
Engineering Division. November 4, 1980.
Erdmann, John F. 1980. Environmental Protection Coordinator,
Union Carbide Corporation, Texas City, Texas. Telecon with
M. A. Cassidy, TRW Environmental Engineering Division.
December 4, 1980.
Ethyl Corporation. 1980. Telecon with Joy Reed of TRW Environmental
Engineering Division. July 1980.
Fannin, James. 1981. B. F. Goodrich Chemical Division. Telecon with
M. A. Cassidy, TRW Environmental Engineering Division. February 18, 1981.
Ferrell, John. 1980. Union Carbide Corporation, Tucker, Georgia PVC
Plant. Telecon with M. A. Cassidy, TRW Environmental Engineering Division.
December 5, 1980.
Finch, Walter. 1980. Senior Process Engineer, Conoco Chemicals. Meeting
report - Conoco/EPA/TRW meeting at RTP. October 17, 1980.
Gilmore, J. M. 1980. Plant Manager, Goodyear Tire and Rubber Company,
Niagara Falls, New York PVC plant. Semi-Annual Report.
September 10, 1980.
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Holbrook, W. C. 1979. Director of Toxicology and Environmental Affairs,
B. F. Goodrich Chemical Group. Letter with attachments to
Donald R. Goodwin, U.S. EPA. November, 19, 1979.
Holbrook, W. C. 1980(a). Director of Toxicology and Environmental
Affairs, B. F- Goodrich Chemical Group. Telecon with J. W. Bodamer, Jr.,
TRW Environmental Engineering Division. October 17, 1980.
Holbrook, W. C. 1980(b). Director of Toxicology and Environmental
Affairs, B. F. Goodrich Chemical Division. Letter with attachments
to J. W. Bodamer, Jr., TRW Environmental Engineering Division.
December 12, 1980.
Holbrook, W. C. 1980(c). Director of Toxicology and Environmental
Affairs, B. F. Goodrich Chemical Division. Trip report - visit to
the Pedricktown Polyvinyl Chloride Plant. September 17, 1980.
Kachtick, James. 1980. Tenneco Chemicals, Pasadena Texas PVC plant.
Telecon with M. A. Cassidy, TRW Environmental Engineering Division.
December 2, 1980.
Konter, Ken. 1980. Senior Environmental Engineer, B. F. Goodrich
Chemical Division. Telecon with Matthew Boss, TRW Environmental Engineering
Division. December 5, 1980.
Laundrie, Robert. 1980. General Tire and Rubber Company, Chemical and
Plastics Division. Trip report - visit to General Tire's polyvinyl
chloride facility in Ashtabula, Ohio. September 10, 1980.
Ledvina, Joseph C. 1980. Director of Environmental Activities, Conoco,
Inc. Meeting report - representatives from Conoco, TRW, and EPA.
October 17, 1980.
Legro, Stanley W. 1977. Environmental Protection Agency, Division of
Stationary Source Enforcement. Letter to Regional Enforcement Directors
containing determinations of equivalent compliance methods for vinyl
chloride. May 26, 1977.
McCulley, John H. 1980. Chemicals Division, Conoco Inc. Letter to
J. W. Bodamer, Jr., TRW. December 16, 1980.
Moulthrop, Samuel P. 1980. Enforcement Division, EPA Region II.
Telecon with J. W. Bodamer, Jr. of TRW Environmental Engineering Division.
November 10, 1980.
Neveril, R. B. 1978. Capital and Operating Costs of Selected Air Pollution
Control Systems, CARD, Inc., 1978. EPA Contract No. 68-02-2899.
December 1978.
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Pucci, Michael. 1980. NESHAP Coordinator for EPA Region II. Meeting report
TRW visit to Region II Offices, New York. August 12, 1980.
Richter, S. H. 1975. Arthur G. McKee and Company, Cleveland, Ohio. "Size
Relief Systems for Two-Phase Flow," Hydrocarbon Processing. July 1975.
Schaul, Peter. 1980. EPA Region III. Meeting report - TRW visit to
Region III Offices, Philadelphia. September 16, 1980.
Sittig, Marshall. 1977. How to Remove Pollutants and Toxic Materials
From Air and Water. Noyes Data Corporation. 1977.
Smith, Cornelius. 1980. Chief Environmental Attorney, Union Carbide
Corporate Headquarters, New York, New York. Telecon with M. A. Cassidy,
TRW Environmental Engineering Division. December 5, 1980.
Ullrich, David A. 1981. Chief, Air Enforcement Branch EPA Region V.
Letter to Jack R. Farmer, EPA. April 28, 1981.
Varner, Bruce. 1980. NESHAP Coordinator for EPA Region V. Meeting
report - TRW visit to Region V offices, Chicago. August 19, 1980.
West, Michael. 1981. Air Facilities Branch, EPA Region II. Letter to
J. W. Bodamer, Jr., TRW Environmental Engineering Division.
January 21, 1981.
Wu, James. 1980. NESHAP Coordinator for EPA Region IV. Telecon with
J. W. Bodamer, Jr., TRW Environmental Engineering Division.
November 7, 1980.
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5.0 ENFORCEMENT AND COMPLIANCE EXPERIENCE
5.1 INTRODUCTION
Industry representatives and Regional EPA personnel presented their
viewpoints drawn from experience with enforcement and compliance under
the existing VC NESHAP. Many of these points were common to industry
and EPA regional personnel while others were specific to enforcement
problems or compliance experiences. These comments are reviewed below
and have been categorized as they pertain to requirements in the
regulation. (All of the following are opinions expressed by industry
and/or EPA personnel.)
5.2 INTENT OF THE STANDARD
t Health effects: Nearly all of the industrial representatives
contacted (and one Regional EPA person) expressed concern over
the potential revision of the NESHAP without a health effects
basis (Baise, 1980).
• The intent of the standard (with regard to emergency releases)
could be achieved by using a "bubble concept" total plant
control as an endpoint (Hoibrook, 1980). It is not always
possible to achieve the 100 percent compliance required by the
current regulation. There should be "malfunction language"
written into a revision. A source should be allowed to offset
emissions in another area of the plant until inoperative
control equipment is repaired. For example, if the source's
primary stripping unit goes down but stripping can also be
done in the reactor, the slowing of production to allow longer
residence time in the reactor is a self-imposed economic
penalty and would allow the source to continue operating under
a "short-term bubble." In California (South Coast Air Quality
-------
Management District) a bubble or group of emissions from a
plant is allowed. Their discharge limit (50 grams per hour)
is based on a Dames and Moore study (Fannin, 1980). The
California Air Resources Board (CARB) set an ambient VC stan-
dard of 10 ppb. This ambient level was based on the lowest
possible detectable limit for VC at that time. Dames and
Moore then calculated that an emission limit of 50 grams per
hour would maintain the ambient level of 10 ppb. (See Chapter
7 for further discussion).
• PVC plants that are regulated by more stringent requirements
should receive a blanket exemption from NESHAP (Holbrook, 1980).
NESHAP regulations are designed to protect the public from
hazardous air pollutants. However, in some cases, regulations
designed to protect the public from nonhazardous air pollutants
are more stringent than a NESHAP. For example, a new PVC
plant constructed in a nonattainment area for hydrocarbons (an
area of the country that does not meet the required criteria
pollutant limits) may be forced to control VC emissions more
strictly than the VC NESHAP requires. A PSD permit will not
be issued unless the new plant can show that the lower levels
can be attained.
5.3 STANDARDS FOR EDC AND VC PLANTS
• Industry feels that there should be separate sections in the
regulation specifically for EDC, VC, and PVC plants (Oubre, 1980).
The regulation should identify more specifically those requirements
applicable to each plant.
• Regional EPA personnel and industry note that the classification
of "in VC service" is a point of contention.
5.4 EXHAUST GASES TO THE ATMOSPHERE
• Industry feels that an allowance should be made for a reasonable
amount of down time for control equipment. Emissions from
shutdown may actually be greater than emissions that would
occur if the plant were to continue operating (Ledvina, 1980;
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Holbrook, 1980). The shutdown, as well as start-up, of an
EDC/VC plant can create more emissions than are discharged by
a plant that is allowed to run for a certain period of time
without control devices.
5.5 INPROCESS WASTEWATER
• Under the current regulation, industry is required to measure
VC concentration in wastewater following stripping only at the
time of start-up of the stripper. Unless monitoring is required
on a regular basis, the effectiveness of the wastewater stripper
cannot be determined.
• One region felt that daily sampling of inprocess wastewater
(following stripping) should be required to ensure proper
stripper operation and maintenance. (One plant in that region,
Borden Chemical, routinely tests wastewater stripper VC concen-
trations.) Compliance with the regulations has drastically
increased the quantity of inprocess wastewater discharged from
many plants (Varner, 1980).
• The wording of the current inprocess wastewater definition
includes that water used to seal gasholders. This seal water
should be made exempt from the inprocess wastewater definition
(Wyatt, 1980).
5.6 REACTOR OPENING LOSS (ROL)
• Industry and regional EPA personnel see a need for a separate
standard for processors stripping in the reactor. The current
regulation assumed the stripping operation was separate from
the polymerization reactor (i.e., took place in a different
vessel), which is not always the case. The resulting problem
is that the test method developed for measuring the ROL is not
applicable to plants stripping iji the reactor. It is possible
to use the headspace volume of gas above the resin slurry, but
the slurry and reactor are too hot to measure immediately, and
after the resin is stripped to the required limit, it continues
to emit VC into the headspace (Wyatt, 1980). The proposed
revision of the standard would be based on a combination of
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ROL requirements and resin stripping levels (Ledvina, 1980;
Brittain, 1980; Varner, 1980; Hoi brook, 1980). Currently,
processors stripping in the reactor show compliance by stripping
to the required levels and calculating the ROL emissions. The
only problem with this method is that the calculation does not
show valves that may be leaking back into the reactor, causing
emissions to be higher than calculated.
• Industry would like to see a provision for monthly or semi-annual
averaging of the ROL (Hoibrook, 1980). This would apply
mainly to bulk processors and other plants stripping in the
reactor.
• Concern was expressed about the prevalence of "ritualistic
sampling," in which the reactor is opened before analytical
results of the resin samples are available and/or slurry
transferred to another vessel. The current regulation requires
that the resin must sampled to determine compliance with
stripping levels; but before the analysis can be completed,
the slurry has already been transferred to the next vessel
(Pucci 1980).
• Regional EPA personnel see a need for a prescribed method of
testing for opening of the Pre-polymerizer (Pre-Po) in the
bulk process. Because the Pre-Po is involved in only 10 percent
of the polymerization reaction and is currently defined as a
"reactor" under the standard, there are problems associated
with determining compliance for these vessels; i.e., should
equipment opening loss or reactor opening loss standards be
applied. Post-polymerization (Po-Po) reactors are opened
after every batch, whereas Pre-Po reactors are not opened as
frequently (Brittain, 1980). The intention of the regulation
was that the Pre-Po and Po-Po combined meet the ROL standard.
Industry currently applies the ROL to each reactor.
5.7 RELIEF VALVE DISCHARGES
• The primary concern about relief valve discharges, shared by
industry and regional EPA personnel, is how to determine what
5-4
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is "preventable." This point was raised more frequently than
any other by EPA regions and industries.
• All of the industrial representatives stated that the zero
concept for relief valve discharges was unrealistic. Many
felt that frequency of discharge and the quantity of VC dis-
charged should be the basis for determining the level of
compliance (Holbrook, 1980; Laundrie, 1980).
• Industry pointed out that controls for dispersion, suspension,
bulk, and solution processes differ. They suggest that the
prevalence of reactor discharges by resin types should be
studied (Holbrook, 1980).
• Industrial personnel have cautioned against recommending
gasholders as containment for relief valve discharges. They
regard this as a safety and economic issue (Holbrook, 1980;
Laundrie, 1980; Ledvina, 1980).
• An opinion expressed by industry is that 100 percent compliance
100 percent of the time should not be required and cannot be
attained. They suggest that a malfunction clause be incorporated
(Holbrook, 1980; Ledvina, 1980).
• Industry suggested that the VC standard could be made more
consistent with other standards (e.g., proposed benzene)
standards with regard to control of equipment breakdown that
results in emergency discharges of a certain level.
• Two regions pointed out that due to substitutions of other
devices in place of relief valves (e.g., double rupture discs)
the standard should be reworded to change "relief valve
(discharge)" to "relief device, including but not limited to
..." (Brittain, 1980).
5.8 RESIN STRIPPING
• Industry feels that the language used to describe resin "grade"
is ambiguous and this affects the resin stripping regulations.
• Industry and Regional EPA personnel state because each resin
grade has unique characteristics that require different stripping
techniques, allowance should be made in the standard for
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stripping levels reflecting pertinent resin requirements
(Holbrook, 1980; Laundrie, 1980; Shaul, 1980).
Industry would like relief from the daily calibration and
monitoring requirements of the current regulation (Wyatt, 1980).
For example, the suggestion was made by industry that longer
averaging periods should be permitted for determining stripping
level compliance (Laundrie, 1980; Mercier, 1980). Daily
compliance with resin stripping levels could be shown by
reporting certain process parameters (e.g., vacuum pulled,
temperature, time in stripper) that industry has proven achieve
the required levels. Sampling could then be required on a
less frequent basis to support the process parameters. (Note:
The preamble to the regulation, published in the Federal
Register, does make provisions for using process parameters to
demonstrate compliance. The preamble states that, "For both
reactor opening and improved stripping, it is possible that
the relationship between the emissions measured and the corres-
ponding operating procedures used to attain the emissions
measured can be established." (40 FR 59543.)
One region suggested the possibility of applying a standard for
new sources (under NESHAP) for stripping with retrofitting
requirements for existing sources. This would encourage the
industry to pursue the technology available for reducing emission
levels below current requirements. Several plants are stripping
suspension resins to less than 400 ppm by continuous stripping
(Brittain, 1980).
Sampling and analytical requirements for resin stripping in
the solution polymerization process need to be reviewed (Brittain,
1980). The stripping requirements (in the current regulation)
were developed for the removal of unreacted VC from solid
particles of PVC. However, there is no particulate resin form
for solution resins. Solution resin stripping involves a
distillation mechanism rather than a diffusion mechanism as in
solid particles. Accordingly, solution resins can be stripped
to an average level of 10 ppm or less. Therefore, the sampling
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and analytical procedures to ensure that the 400 ppm level is
met for solution resins are relatively extensive.
5.9 SOURCES AFTER THE STRIPPER
• Regional EPA personnel suggest that dryer emissions be reevaluated.
Based on a Prevention of Significant Deterioration (PSD)
application, an average suspension plant producing 90 gigagrams
(100,000 tons) of PVC resin per year will emit 36 megagrams
(40 tons) of VC per year out of the dryer stack. Indirect
drying (which would reduce drying air and make add-on control
more economical) followed by a control or product recovery
device, may be a better way to reduce these emissions (e.g.,
one PVC plant uses steam coils that indirectly heat the
resin in a rotary dryer) (Pucci, 1980).
t Blend tanks and centrifuges, the next steps following the
stripping operation, have been suggested as potentially
significant emission sources (Pucci, 1980).
• One region's PSD Best Available Control Technology (BACT)
analysis shows that 20 to 40 times as much VC is allowed to
escape from process units following the stripper as is allowed
from ROL and the 10 ppm exhaust emissions (Varner, 1980).
5.10 FUGITIVE EMISSIONS
• One region proposed that plants submit representative data on
ambient (background) levels in annual report form, similar to
the draft generic standards. This would provide a means to
determine the plant's progress in lowering background levels
and to establish criteria for evaluating fugitive control. A
certain percent deviation would be permitted and if the plant
achieved an average of a prescribed level, it would be in
compliance (Brittain, 1980b).
• The submission of an annual report as mentioned above would
also allow the responsible EPA Region to reevaluate the Leak
Detection and Elimination Programs and, thus, reject a previously
approved program (Flynn, 1980).
• An industrial source maintains that the levels for fugitives
predicted in the Standard Support and Environmental Impact
5-7
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Statement document for the original standard were considerably
higher than actual levels. This company has determined the
relationship of fugitive emissions to production rate and has
measured suspension and dispersion process fugitives to be 25
percent of the predicted levels for their older small reactor
suspension and dispersion plants (Holbrook, 1980).
5.11 LEAK DETECTION AND ELIMINATION PROGRAMS
• Many industrial sources, as well as regional EPA personnel,
regard the definition of a leak in the standard as unclear.
"Small" and "major" leaks need to be defined. The setting of
a de minimus level was suggested (Yonge, 1980; Oubre, 1980;
McNair, 1980; Pucci, 1980; Wu, 1980; Flynn, 1980).
• As previously mentioned, regional personnel have no way of
determining the success of the programs in lowering fugitive
emissions background levels in the plants (Brittain, 1980).
• One region commented that the location of monitors, while
serving OSHA purposes, may not be optimal for fugitive detection
(e.g., many sources do not monitor storage areas) (Pucci,
1980).
• Several industrial representatives said that their Leak Detection
Programs, submitted to Regional EPA offices, are rarely
acknowledged (Yonge, 1980; Oubre, 1980; DeBernardi, 1980).
5.12 EMISSIONS TESTING AND ANALYSIS
t Region II commented that the units for allowable emissions
from equipment opening are inconsistent. For larger pieces of
equipment, such as a surge tank serving an incinerator, the
allowable emissions should be similar to the ROL standard.
Only the smaller pieces of equipment (e.g., loading/unloading
lines) should have the 2 percent by volume or 25 gallon cutoff
(Pucci, 1980).
• The continuous emission monitoring standard for the primary
control device does not specify whether a "minute to minute"
monitor (as for a NSPS) or a sequential leak detection monitor
is required (Pucci, 1980). No performance specification
5-8
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exists for these continuous emission monitors in the current
regulation; this requirement of the regulation should be made
consistent with the NSPS requirements so that continuous
monitoring results can be used for determining violations of
emission standards (Varner, 1980; Pucci, 1980).
Sampling regulations for RVC are currently under the section
(61.70(c)(2)(ii) for semi-annual reporting in the standard.
It would be more appropriate to locate this regulation under
testing (Section 61.67) and monitoring (Section 61.68)
(Brittain, 1980).
Sampling bag sizes, specified in methods 106 and 107, are too
large for the sample (Ledvina, 1980).
Methods 106 and 107 call for "zero-grade" gas for analysis.
This method is very expensive to use on a day-to-day basis.
Stack sampling should utilize zero-grade gas, but it is not
necessary for daily analyses (Hoibrook, 1980).
Industry feels that instrumental calibration on a daily basis
is not necessary. Drift history, etc., should be allowed to
establish the reliability of the instruments (Holbrook, 1980;
Oubre, 1980; DeBernardi, 1980).
One region said that a source reported calibration requirements
for a daily span check actually caused an increase in emissions
(Pucci, 1980).
Industry would like to establish its own program for calibration
procedures with periodic checking of internal standard operating
procedures by regional EPA personnel (DeBernardi, 1980).
Some industrial representatives feel that the standard should
not restrict analysis to specific instruments. There are
questions as to reliability and availability of parts for some
of the required instruments (Ledvina, 1980).
Method 106 for ROL measurements is not considered to be reliable.
Corrections for condensing water vapor in the sample cannot be
made reliably (Ledvina, 1980).
Region VI suggested the need for a monitoring performance
standard for backup as well as primary control devices. When
5-9
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VC emissions are bypassed to the atmosphere (e.g., in the case
of a malfunction or shutdown of a primary control device), a
backup incinerator, or a flare, the downstream monitor does
not measure any VC. Region VI feels that monitors for VC
should be located so that actual emissions of VC to the
atmosphere are always measured during all process operating
conditions (Harrison, 1979).
5.13 REPORTING
• Industry made several comments regarding the lack of uniformity
in reporting requirements among the regions. Frequency of
reports and level of detail required were given as examples of
differences (Hoibrook, 1980; Laundrie, 1980).
• Industry suggests that the possibility of consolidation of
permits be considered (Holbrook, 1980).
• Many comments were made by Regional EPA personnel regarding
semi-annual report requirements. The regions do not consider
the semi-annual reports effective for enforcement purposes.
They feel that excursions should be reported on a 10-day basis
or immediately, with a minimum frequency of four times a year
(Thompson, 1980; Aronson, 1980; Varner, 1980).
• Industry feels that semi-annual reporting should be replaced
with exception reporting (Holbrook, 1980).
5.14 RECORDKEEPING
• Industry feels recordkeeping should be reduced to include only
exception or noncompliance data for the pertinent time frame
(Holbrook, 1980). This would reduce the amount of records
required to be maintained onsite.
• One region pointed out that the standard does not specify a
time limit for retention of ROL records (Varner, 1980).
5.15 NESHAP APPLICABILITY DETERMINATIONS
Since promulgation of the VC NESHAP, several inquiries have been
made regarding the applicability of VC-use situations to the standard.
The following are examples of the type of inquiries directed to the
Division of Stationary Source Enforcement (DSSE) (Reich, 1980; King,
1980).
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Question
Are duplicate continuous
monitoring systems needed
for vinyl chloride plants?
Determination
No
Is EPA concerned with
short-term monitoring
malfunctions?
Are relief valve
discharges which are
due to operator error
considered violations
of section 61.65(a)?
Yes
Conditional
Can a demonstration of
noncompliance of the
reactor opening loss
standard, using an
unapproved test method,
support an enforcement
action?
When is a relief valve
discharge a violation
of section 61.65(a)?
No
What measures can be
taken to prevent relief
valve discharges?
Discussion
Although backup moni-
toring equipment is not
required, it is the
responsibility of the
source to ensure that
the monitoring equipment
operates continuously.
The vinyl chloride stan-
dard does not provide for
monitoring malfunctions
of any duration - EPA is
concerned about any
malfunction.
Relief valve discharges
resulting from operator
error are considered
violations if the errors
are preventable. The fol-
lowing are examples of
preventable operator
errors:
1. Errors due to lack
of training
2. Negligence
If a source is using a
test method which has not
been approved by EPA as
an equivalent or alter-
nate test method,
information pertinent to
the method should be
submitted to EPA for
evaluation.
A relief valve discharge
is a violation if it
could have been antici-
pated and preventative
measures could have been
taken or prevented by
proper operating, main-
taining and inspecting
equipment.
Examples of measures that
can be taken to prevent
relief valve discharges
include:
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Question
Determination
Discussion
1. Properly instru-
menting the reactor to
detect upset conditions.
2. Injecting chemicals
to stop polymerization
reaction during upset
conditions.
3. Venting reactor con-
tents to a gasholder and
ultimately to a recovery
system.
4. Maintaining a backup
source of power.
5. Proper training of
employees.
No Tank cars are not subject
to the vinyl chloride
regulations, except to
the extent that the
requirements for purging
of loading and unloading
apply.
No The regulation applies to
plants which produce EDC,
VC, or PVC. The standard
specifically places
requirements on the
reactor, stripper, con-
tainers (mixing,
weighing, and holding),
monomer recovery system,
and sources following the
stripper. If all dis-
charged material meets
the requirements of this
subpart prior to its
exposure to the atmos-
phere, this subpart does
not apply to the PVC
sludge drying facility
because the process is
not considered part of
the production processes
of EDC, VC, or PVC plants.
These are representative questions directed to many of the EPA
Regions and are indicative of the need to clarify some points in the
regulation.
Are vinyl chloride tank
cars that are transported
by rail to a vinyl
chloride plant, "equip-
ment in vinyl chloride
service"?
Is a PVC sludge-drying
facility, designed to
accommodate sludge with
some low residual VC
content, subject to the
VC NESHAP regulations?
5-12
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5.16 REFERENCES FOR CHAPTER 5
Aronson, Wayne, EPA Region IV, Air Enforcement Branch. Meeting report -
TRW visit to Region IV offices. September 3, 1980.
Baise, Gary, Attorney, Beveridge, Fairbanks and Diamond. Meeting report -
TRW/EPA/SPI meeting at Durham, N. C. July 31, 1980.
Brittain, Martin, NESHAP Coordinator, EPA Region VI. Meeting report -
TRW visit to Region VI offices. October 27, 1980.
DeBernardi, James, Plant Manager, Lake Charles, La. Conoco Plant. Meeting
report - TRW visit to Conoco Plant. August 7, 1980.
Fannin, James, B. F. Goodrich Chemical Division. Meeting report - TRW
visit to B. F- Goodrich Cleveland office. October 30, 1980.
Environmental Protection Agency. 1975. "NESHAP Proposed Standard
for Vinyl Chloride," Federal Register, Vol. 40, No. 248. December 24, 1975.
Flynn, Peter M. Environmental Engineer, Air Facilities Branch, EPA
Region II. Letter to J. W. Bodamer, Jr., December 2, 1980.
Fradkoff, Steve, Region I EPA. Meeting report - TRW visit to Region I
offices. August 13, 1980.
Harrison, Arlene, Regional Administrator, EPA Region VI. Letter to
Don Goodwin. January 29, 1979.
Holbrook, W. C., Director of Toxicology and Environmental Affairs,
B. F. Goodrich Chemical Division. Trip report - visit to the
Pedricktown Polyvinyl Chloride Plant. September 17, 1980.
King, J. A., DSSE, USEPA. Letter to Regina E. Thompson, EPA Region III,
1980.
Laundrie, Robert W., General Tire and Rubber Co. Trip report - TRW
visit to the Ashtabula, Ohio PVC plant. September 10, 1980.
Ledvina, Joseph C., Director of Environmental Activities, Conoco, Inc.
Meeting report - representatives from Conoco, TRW and EPA. October 17,
1980.
McNair, Cathy, NESHAP Coordinator, EPA Region I. Meeting report - TRW
visit to Region I offices. August 13, 1980.
Oubre, Robert, Technical Manager, Dow Chemical Corp., Oyster Creek
Division. Trip report - TRW visit to Oyster Creek plant. August 5,
1980.
Pucci, Michael, NESHAP Coordinator for EPA Region II. Meeting report -
TRW visit to Region II offices, New York. August 12, 1980.
5-13
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Reich, Edward, DSSE, USEPA. Letter to EPA Regional Directors regarding
Summary of NESHAP Determinations, 1980.
Schaul, Peter, EPA Region III. Meeting report - TRW visit to Region III
offices, Philadelphia. September 16, 1980.
Thompson, Jean, NESHAP Coordinator, EPA Region III. Meeting report -
TRW visit to Region III offices. September 16, 1980.
Varner, Bruce, NESHAP Coordinator for EPA Region V. Meeting report -
TRW visit to Region V offices, Chicago. August 19, 1980.
Wu, James, NESHAP Coordinator for Region IV. Meeting report - TRW visit
to Region IV offices. September 3, 1980.
Wyatt, Susan R. 1980. Office of Air Quality Planning and Standards.
U.S. EPA Meeting report - TRW visit to OAQPS. June 16, 1980.
Yonge, John, Environmental Control Supervisor, Shintech, Inc. Trip
report - TRW visit to Shintech Plant, Freeport, Texas. August 5, 1980.
5-14
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6.0 UNREGULATED SOURCES OF VINYL CHLORIDE
6.1 INTRODUCTION
The current regulation is applicable to the following types of
facilities:
(1) plants producing EDC by the reaction of oxygen and hydrogen
chloride with ethylene,
(2) plants producing VC by any process, and
(3) plants producing one or more polymers containing any fraction
of VC.
There are, however, several categories of VC-emitting facilities that
are not regulated under the current VC NESHAP. Many of these sources
were identified during the original study. These include PVC compounders
and fabricators, and processors who use VC as a chemical intermediate or
produce it as a byproduct.
New sources of unregulated VC emissions have been identified during
this review study. They include mobile-mounted sources, nonplant transfer
facilities, solid waste drying facilities, and disposal sites.
Many of the sources not regulated by the VC NESHAP are subject to
state hydrocarbon-emission control standards, specifically those plants
located in nonattainment areas.
6.2 SOURCES IDENTIFIED DURING THE ORIGINAL STUDY
6.2.1 Fabricating Operations
Following polymerization of VC, two major processes are involved in
the conversion of VC to a finished PVC product - compounding and fabricating.
Compounding involves the mixing of PVC resins with additives such as
plasticizers, stabilizers, pigments, blowing agents and anti-oxidants.
These additives impart certain properties that are required for handling
the polymer during fabrication as well as in the final product. Compounding
-------
may be done by the fabricator, the resin producer, or by independent
compounders.
Fabrication of the polymer consists of melting and shaping the
compound by various processes. Some of the major processes are:
t Extrusion - This process consists of mixing and melting a
continuous stream of plastic and generating sufficient pressure
to force the compound through a die.
• Calendering - The compound is fed through sets of rollers to
form continuous sheets of plastic.
• Molding - Several types of molding are used; injection,
compression, vacuforming, and embossing constitute the more
common processes.
• Bonding - The joining of two or more pieces of PVC can be
accomplished using heat (or heat and pressure), adhesives, or
hot gas welding.
Most of the residual VC (RVC) in the resin is lost at the PVC
plant. Following stripping operations (which remove RVC to levels at or
below those required by the regulation) further losses of RVC occur in
drying, bagging, and storage operations. More RVC can be lost while the
resin is in transit. Thus, operations following the stripper (and prior
to compounding operations) account for the reduction in RVC levels
entering compounding and fabricating facilities as compared with those
found in the stripped resin. The application of heat and pressure
during fabrication can cause some of the remaining RVC to diffuse from
the resin particles.
A.D. Little (1975) prepared a report on VC emissions from PVC
processing industries for the EPA in August 1975. This report
quantified the VC emissions from compounders and fabricators of PVC
resins. The conclusions drawn from the study were:
• There are more than 8000 PVC fabricating facilities in the
United States,
• Emissions from compounding and subsequent fabrication processes
together accounted for less than one-half of one percent of
the total United States emissions, and
6-2
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• The most promising control technique to limit VC emissions to
the atmosphere from compounding and fabricating facilities
appeared to be further reduction of RVC levels in incoming
resins. At the time of the 1975 study, average VC content of
raw resin was reported to be 300 ppm (in 1974), with PVC
q
production rates of 2.0 teragrams (4.4 x 10 pounds). Total
VC release from compounding and fabricating facilities during
1974 was 600 megagrams (1.3 x 10 pounds).
Since promulgation of the OSHA VC workplace standard (permissible
occupational exposure level), PVC manufacturers have reduced the RVC
content in the resins supplied to compounders and fabricators. To
control VC exposure in fabrication facilities, the PVC industry has
established a 10 ppm VC concentration limit in dried PVC resins.
Surveillance and enforcement of this requirement has been delegated to
the Plastic Pipe Institute (Cameron et al., 1980, p. 43).
In addition to the influence of the OSHA standard, requirements by
the Food and Drug Administration (FDA) have contributed to the reduction
of RVC levels in resins supplied to fabricators. PVC products that will
come into contact with humans are required to have very low levels of
RVC. Therefore, resins to be used for blood bags, food wrap, drug and
beverage bottles, etc., enter the fabricating facilities with RVC levels
well below 1 ppm. Bottle resin, for example, is currently provided at
levels less than 0.05 ppm (Ter Haar, 1980.)
Of the PVC plants surveyed, all report that average PVC levels in
resin leaving the plant range from <0.002 ppm to 10 ppm. Many plants
report levels of <0.5 ppm to 1 ppm. Typical reductions in resin RVC
since promulgation of the VC NESHAP are shown by the following data from
a PVC resin manufacturer (Ter Haar, 1980):
Resin type
Emulsion Resins
Bottle Resins
Other Suspension Resins
RVC Levels
Prior to 1974
3.0
—
935
(ppm)
Current
0.5
<0.05
2.6
6-3
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In 1979, PVC production rates were reported to be 2.8 teragrams (6.1 x
9
10 pounds) (Chemical and Engineering News, 1980, p. 13). Assuming that
the average RVC content of the resins supplied to compounders and
fabricators is 10 ppm and that all of the VC is lost to the atmosphere
during fabrication (worst case assumption), total emissions from these
A
sources for 1979 would have been 28 megagrams (6.1 x 10 pounds) VC.
The emission levels from these sources would actually be much lower
than those cited above since average RVC content of incoming resin is
probably less than 10 ppm. In addition, VC migration studies indicate
that a very low percentage of monomer is released during fabrication.
During extrusion, for example, 10 percent of the monomer is typically
released (Ter Haar, 1980).
EPA conducted ambient air studies in which five PVC fabrication
plants were monitored. There were no measured concentrations of VC
emitted from three of these plants. The highest measured concentration
was 0.006 ppm, 24-hour average (Padgett, 1980).
6.2.2 Miscellaneous Sources
In a study done by Arthur D. Little, Inc. for the EPA (Lyman,
1976), miscellaneous sources of VC emissions were categorized as follows:
• Industrial processes in which VC is used as a chemical
intermediate for the production of other chemicals,
• Industrial processes in which VC is used as a minor
constituent (<50 percent by weight) for the production of
resins, and
• Industrial processes in which VC is produced as a byproduct of
the chemical reaction involved.
The second category, use of VC as a minor constituent in resin
production, no longer represents an unregulated source, as these
processes are now subject to the current VC NESHAP regulations (i.e.,
any amount of VC used for polymerization constitutes a regulated process),
Within the first category (use of VC as a chemical intermediate),
two main sources were identified by the Arthur D. Little study:
(1) production of 1,1,1-Trichloroethane (1,1,1-TCE) and 1,1,2-Trichloro-
ethane (1,1,2-TCE); and (2) production of other special chemicals such
as certain pesticides.
6-4
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A more recent survey conducted by Conoco (McPherson, 1979, p. 75)
attributes three to four percent VC usage to the manufacture of 1,1,1-TCE.
Information pertaining to the current status of VC emissions from the
manufacture of 1,1,1-TCE and 1,1,2-TCE was not obtained during the
review study.
VC emissions from pesticide manufacturing facilities were identified
in the Arthur D. Little report. Total VC consumption was estimated to
be only two percent of the amount estimated for TCE production. One of
the two plants cited in the study, an insecticide manufacturing facility,
was contacted during the current VC NESHAP review study. It appears
that VC consumption, control technology, and emissions are essentially
the same as they were when the Arthur D. Little study was done (Vines,
1981). At that time, VC emissions to the atmosphere were estimated to
be about 0.14 kilograms (0.3 pounds) per day.
The third category (VC as a byproduct) encompassed the following
processes existing in the United States:
(1) the manufacture of EDC via oxychlorination, and
(2) the manufacture of ethylene amines and ethylene imines from
EDC.
The first process is now regulated under the existing VC NESHAP. Current
information on VC emissions from ethylene amine production confirms that
VC, as a byproduct in these processes, represents a very minor source of
emissions (actual amounts not known). A representative of a plant
manufacturing ethylene amines stated that the small amount of VC involved
is directly vented to the incinerator in one plant. In another plant,
VC is sent to the VC recovery column at their PVC facility. In either
case, storage and handling of VC is not a factor. VC fugitive emission
surveillance in these plants has shown no detectable VC levels (Wise,
1981).
6.3 NEW SOURCES IDENTIFIED DURING THE REVIEW STUDY
6.3.1 Mobile-mounted Sources of Emissions
Three areas of mobile-mounted emission sources have been noted by
some regional EPA personnel. These are rail cars, tank cars, and marine
unloading facilities. Department of Transportation (DOT) and Coast
6-5
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Guard regulations are primarily concerned with flammability and water
pollution parameters. No designation of responsibility for VC emissions
into the air has been assigned for rail car leaks (Aronson, 1980).
Several companies have reported relief valve discharges associated with
the unloading of VC from ships at marine unloading facilities (Brittain,
1980).
Facilities used for cleaning rail and tank cars transporting liquid
VC are often remote from regulated sources. There is a question as to
whether these facilities or the VC supplier should assume responsibility
for resultant VC emissions.
6.3.2 Nonplant Transfer Facilities
Terminals for transfer and short term storage of VC from marine
vessels are under the jurisdiction of the Coast Guard and are not regu-
lated by the VC NESHAP. The significance of emissions from these
intermediate facilities is a concern of Regions I and VI (Pucci, 1980;
Brittain, 1980). Because 16 of the 18 operating EDC/VC plants are
located in Region VI and most of these plants are proximate to marine
waters, this potential source of VC emissions is of major concern to
Region VI as well as the plants who normally take responsibility for the
emissions. In addition, many sources are clustered in the northeastern
United States and VC can be transferred by marine vessels to transfer
facilities near the sources. One' of these transfer facilities was
identified in Region II, but has temporarily been shut down.
The unregulated source of emissions is usually from a safety relief
valve on the marine vessel (barge or ship) that discharges when overpres-
surization occurs during loading and unloading. One plant in Region VI
reported a total of 871 kilograms (1936 pounds) of VC emitted from
marine vessel relief valves over a 3.5 year period since 1977. This is
comparable to 58 percent of the total quantity of relief valve discharges
reported during this same time period. However, in most cases, the
discharges from marine vessels are not reported because this source of
emissions is not regulated (Brittain, 1980).
6-6
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Tank farms, used for temporary VC storage and potentially for
emergency stockpiling (due to rail strikes, etc.)> are not currently
regulated under the standard (Schaul, 1980; Varner, 1980).
6.3.3 Solid Waste Drying Facilities
One facility is currently installing a PVC sludge drying operation,
designed to accommodate sludge with some low residual VC content. Such
facilities are considered to be potential VC emission sources (Schaul,
1980). However, the sludges to be dried at these facilities contain PVC
resins that have already met requirements for resin stripping levels.
6.3.4 Disposal Facilities (Landfill)
VC emissions were recently detected in vents from a landfill in
Region II. These vents were installed mainly for the release of methane
from the landfill. It is thought that PVC wastes, generated prior to
the VC NESHAP's stripping requirements (and therefore unregulated), were
disposed of in the landfill (Pucci, 1980). Measurements made at the
landfill vents showed levels as high as 90.2 ppm. A review of the
design proposed for the new venting system for the landfill included an
evaluation of the number and spacing of the vents as well as an accept-
able means for dealing with the VC emissions. The recommendation report
stated that a manifold burner system would substantially reduce VC
concentration, although the report did not state the level of reduction.
The burner systems suggested included a Hirt Ground Flare and other
waste gas burners. Interim control devices are being evaluated, and
these include activated charcoal cannisters and activated charcoal
tubes. VC has been measured in another landfill nearby, and Region II
suspects that many more exist (Spatola, 1981).
Disposal of off-specification batches of PVC resin has been
identified as a potential VC emission problem. These batches cannot
always be stripped by conventional methods and thus may contain high
levels of RVC. Some off-specification batches can be sold, but many are
discarded. The State of California requires that all of these batches
be stripped to levels appropriate to that resin type, but industry
states that this is not always possible (Fannin, 1980). Ultimate
disposition of the off-specification batches has not been determined.
6-7
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6.4 REFERENCES FOR CHAPTER 6
Aronson, Wayne. 1980. EPA Region IV, Air Enforcement Branch. Meeting
report - TRW visit to Region IV offices. September 3, 1980.
Brittain, Martin. 1980. NESHAP Coordinator, EPA Region VI. Meeting
report - TRW visit to Region VI offices. October 27, 1980.
Cameron, J. B., A. J. Lundeen, and J. H. McCully, Jr. 1980. "Trends in
Suspension PVC Manufacture." Hydrocarbon Processing. March 1980.
Chemical and Engineering News. 1980. "Key Polymers." October 6, 1980.
Fannin, James. 1980. B. F. Goodrich. Meeting with TRW in Cleveland, Ohio.
October 30, 1980.
Little, Arthur D., Inc. 1975. Vinyl Chloride Monomer Emissions From the
PVC Processing Industries. Contract No. 68-02-1332, Task No. 10.
August 1975.
Lyman, Warren J., Arthur D. Little, Inc. 1976. Miscellaneous Industrial
Sources of Vinyl Chloride Emissions i_n the U.S.. Contract
No. 68-02-1332, Task No. 13 (Part 1-A, B, C). March 1976.
McPherson, R. W., C. M. Starks, G. F. Fryer. 1979. "Vinyl Chloride
Monomer . . . What You Should Know." Hydrocarbon Processing. March 1979.
Padgett, Joseph. 1980. Director SASD, EPA. Letter with enclosures to
Al Montague, SAD, EPA. September 23, 1980.
Pucci, Michael. 1980. NESHAP Coordinator for EPA Region II. Meeting
report - TRW visit to Region II offices, New York. August 12, 1980.
Schaul, Peter. 1980. EPA Region III. Meeting report - TRW visit to
Region III offices, Philadelphia. September 16, 1980.
Spatola, Joseph. 1980. EPA Region II, Air and Hazardous Materials.
Telecon with M. A. Cassidy, TRW. January 13, 1981.
Ter Haar, Gary L. 1980. Director of Toxicology and Industrial Hygiene,
Ethyl Corporation. Letter with attachments to Docket Officer, DOL - OSHA.
May 7, 1980.
Varner, Bruce. 1980. NESHAP Coordinator for EPA Region V. Meeting
report - TRW visit to Region V offices, Chicago. August 19, 1980.
Vines, J. H. 1981. Manager Insecticide Production, Chemagro Division of
Mobay Chemical Co., Kansas City, Mo. Telecon to M. A. Cassidy, TRW.
January 6, 1981.
Wise, R. C. 1981. Union Carbide Corp. Telecon to M. A. Cassidy, TRW.
January 7, 1981.
6-8
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7.0 IMPACT OF OTHER REGULATIONS
7.1 INTRODUCTION
The original study, which was done to support the current regulation,
found that existing regulations as well as proposed regulations had
little effect, if any, on the reduction of atmospheric VC emissions from
EDC/VC and PVC plants. The Occupational Safety and Health Administra-
tion's (OSHA) regulations required a combination of ventilation techniques,
engineering and work practice controls, and respirators to reduce worker
exposure. Many of the engineering controls reduced atmospheric emissions,
for example, portable and fixed point monitoring, improved sealing
techniques, transfer line purges, reactor cleaning methods, and improved
stripping, which not only reduced emissions from PVC plants but satisfied
the demands of the fabricators (EPA 1975, p. 9-5). However, it was felt
that compliance with the standard would not be uniform throughout the
industry or significantly reduce VC emissions to the atmosphere.
Some state regulations existed for hydrocarbons and new construction
and they indirectly reduced VC emissions at some plants. Texas regulations
required two EDC/VC plants to reduce hydrocarbon emissions from the
oxychlorination reactor, thus indirectly reducing VC emissions. Louisiana
had similar regulations. New Jersey and Texas both required what was
specified by each state as best control technology for any pollutant,
including VC, when a source was newly constructed or modified (EPA 1975,
p. 9-10). Other regulations concerning water pollution, transport of
VC, aerosol products, and food packaging had no effect on reducing VC
emissions.
However, since promulgation of the standard in October 1976, other
regulations have evolved that can have a potentially greater effect on
VC emitted to the total environment. The following is a list of the new
-------
regulations, policies and requirements that have been established or
proposed.
• Policy and Procedures for Identifying, Assessing and Regulating
Airborne Substances Posing a Risk of Cancer (Proposed Carcinogen
Rule)
• Prevention of Significant Deterioration (PSD)
• Resolution of the South Coast Air Quality Management District
Board (SCAQMD) adopting Rule 1005.1 - Control of Vinyl Chloride
Emissions
• Resource Conservation and Recovery Act (RCRA)
• Toxic Substances Control Act (TSCA)
• Toxic Pollutant Effluent Standards as required by the Clean
Water Act of 1977
• Proposed Primary Drinking Water Regulations
• Potential Revision to the OSHA Workplace Standard for VC
• Transport of Hazardous Wastes and Hazardous Substances
• Food and Drug Administration (FDA) regulations
• Other state and local air pollution regulations
These new regulations have made the acquisition of permits necessary
for construction and operation increasingly complex. The effect of the
new regulatory requirements of the VC NESHAP will be discussed below
with the federal and state laws responsible for implementation.
7.2 CLEAN AIR ACT
The Clean Air Act (CAA) Amendments of 1977 provided a mechanism for
instituting a program for Prevention of Significant Deterioration (PSD)
of Air Quality and plans for nonattainment areas. These regulations
provide for continued protection of the existing ambient air quality
and, in some cases, have had an effect on reducing VC emissions from new
and modified sources. The CAA recently proposed a rule for regulating
airborne carcinogens. The proposed Carcinogen Rule directly affects any
recommended revisions to the current standard that may result from this
review study. In addition, the state of California has established the
first ambient air quality standard for VC and the regulations necessary
for its enforcement.
7-2
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7.2.1 Carcinogen Rule
The Carcinogen Rule, proposed on October 10, 1979, considered
policies and procedures to:
• determine the carcinogenicity and risks for a specific pollutant,
• establish priorities for regulatory action,
• specify degree of control, and
• provide public input to the decisionmaking process. The
proposed rule's requirement for periodic review of NESHAP
regulations triggered this review of the current VC regulation.
At least every 5 years, regulations would be reviewed for
possible modification incorporating technological developments
and health effects information. These reviews provide the
opportunity to consider revising the standard (EPA, 1979a).
7.2.2 Prevention of Significant Deterioration
The original, and more recently revised, PSD and related nonattainment
regulations have been responsible for reducing VC emissions from EDC/VC
and PVC plants, in certain respects, beyond the reductions required by
the current VC NESHAP. The goal of PSD is to ensure that air quality in
clean areas does not significantly deteriorate and yet maintains a
margin for future industrial growth. Clean areas, or those areas meeting
the National Ambient Air Quality Standards (NAAQS) for criteria pollutants,
are classified as attainment areas. New construction or a modification
to an existing applicable source may be subject to PSD review and specific
required analyses.
New construction or a modification to an existing source in a
nonattainment area (an area not achieving the NAAQS) must be reviewed
in accordance with the nonattainment provisions of the applicable State
Implementation Plan (SIP). SIP's represent the plan of action that a
state follows to restore non-attainment areas to attainment areas. EPA
is continuing to publish control techniques guidelines (CTG) for those
industries that emit significant quantities of air pollutants in areas
of the country where NAAQS are not being achieved. CTG's provide infor-
mation to state and local agencies that can be used in maintaining air
quality (i.e., for developing an SIP). The CTG identifies reasonably
available control technology (RACT) that can be applied to the industries
7-3
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to reduce emissions, taking into account technological and economic
feasibility. No CTG currently exists that would directly affect a
regulated VC source. CTG's are in the developmental stages for air
oxidation processes, polymers and resins, which could affect VC sources
in the future.
PSD review is required for sources locating in PSD areas, in areas
designated attainment, or in areas that are unclassifiable for any
criteria pollutant. PSD areas, however, can also be designated non-
attainment for one or more pollutants. In such areas, significant
increases in pollutants for which the area is designated nonattainment
under Section 107 of the CAA are exempt from PSD review. If this is the
case, the facility will still be subject to review according to that
state's applicable SIP. Therefore, a newly constructed EDC/VC and/or
PVC plant (or modification to an existing plant) may be subject to PSD
or non-attainment review or both.
PSD applicability is first determined for the new source or for the
modification to an existing source. A new source is subject to PSD
review if it is: (1) one of the 28 listed sources with the "potential"
to emit 100 tons per year or more of a regulated pollutant, or (2) any
unlisted source with the "potential" to emit 250 tons per year of a
regulated pollutant. Regulated pollutants are the five criteria pollutants
and nine non-criteria pollutants (of which VC is one). "Potential"
emissions incorporate controls, any federal or state permit requirements
and fugitive emissions. A modification to a major source is subject to
PSD review if the physical change or change in operation results in a
significant net emissions increase. The significance level above which
PSD review is required is 1 ton per year for VC and 40 tons per year for
volatile organic compounds.
Once it is determined that the source is subject to PSD review, the
following three analyses are required:
• Best Available Control Technology (BACT) analysis,
• air.quality analysis, and
• additional impact analyses.
The BACT analysis is the most important requirement and it provides
the data for the other two requirements. Because NESHAP regulations do
7-4
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not necessarily require BACT, PSD regulations can override NESHAP
provisions and the resulting requirements for BACT may represent a more
stringent emission control. NESHAP regulations require best available
technology (BAT) which differs from BACT in the procedure used for its
selection. BAT is selected on a nationwide basis considering economic,
energy and environmental impacts, whereas BACT is selected on a plant-
by-plant basis considering economic, energy and environmental impacts.
For this reason, BAT and BACT may not necessarily reflect the same level
of control. Therefore, a new VC source undergoing PSD review may be
required to implement a level of control (i.e., BACT) that is more
stringent than the BAT required by the VC NESHAP.
The primary purpose of BACT is to minimize consumption of increments
(i.e., allowable growth within an attainment area) and thus expand the
area's potential for future growth by addressing the interrelated impacts
of energy availability, economy and environment. BACT determinations
are made on a case-by-case basis, and the results form the basis for
control strategy decisions. A BACT application may exempt a regulated
pollutant from PSD review; for example, a company requesting a permit to
construct an EDC/VC and PVC plant on the same site calculated potential
hydrocarbon emissions to be approximately 5,000 tons per year thus
making the source subject to PSD review (actual quantities of VC emissions
were not determined). However, after application of BACT, the hydrocarbon
emissions, including VC, were reduced to less than 50 tons per year
which resulted in an exemption from PSD review. The BACT determination
required more stringent control of specific VC emission point sources
within the plant to levels less than those required by the VC NESHAP
(Winkler, 1980). In another example an EDC/VC plant was allowed to
discharge approximately 80 tons per year of VC from the oxy vent under
NESHAP. However, the plant chose to incrementally remove 79 tons per
year rather than go through PSD review (Brittain, 1980).
The BACT process involves four steps. The first, pollutant
applicability, has already been discussed. The second step is deter-
mining the emissions unit applicability for the source. All applicable
emissions units must be analyzed. A chemical complex producing EDC, VC
and PVC provides a good example. Each chemical and polymer is made in
7-5
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separate processing equipment with each piece of equipment containing
several emission units. Emissions from all of the units must be summed
for the entire complex which then constitutes one source. Fugitive
emissions are included in determining quantities of emissions from each
unit. Secondary pollutants (i.e., those emissions associated with a
source but not emitted from the source itself) are also included if they
cause a potential air quality standard or increment violation.
The third step in BACT review is to identify sensitive concerns
(i.e., local air quality concerns and potential environmental impacts).
These concerns should be quantifiable, if possible, so that various
control alternatives can be compared. This step also encourages public
involvement.
The last step is to select alternative control strategies. A base
case is first established in order to rank the alternatives and consider
them quantitatively. The base case can be considered the case that
would be applied in the absence of the BACT decisionmaking process.
The choice of the base case is dictated by existing regulations such as
New Source Performance Standards (NSPS) or NESHAP requirements. Selection
of alternatives is usually based on technical feasibility -- previously
demonstrated technology. Innovative technology can be selected also and
PSD allows special consideration for its use.
With the creation and analysis of the base case, alternative control
strategies affording greater degrees of continuous emission reduction
than the base case are ranked in order of control efficiency. The
applicant then conducts an economic, energy and economic impact analysis
for each alternative control strategy. Upon completion of these analyses,
the information will be available to perform the final evaluations that
will lead to proposal of BACT.
The other analyses required after the BACT analysis are an air
quality analysis and an additional impact analysis, both of which rely
on the BACT results. The air quality analysis must demonstrate that
NAAQS or PSD increments will not be violated. This is done for each
regulated pollutant and is accomplished by projecting the air quality
that would exist when the new construction or modification is operating.
Dispersion modeling is used to project this air quality. The modeling
7-6
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takes into consideration the impact area, other sources in the areas,
and existing ambient concentrations. The complexity of the analysis
depends on location, and in some cases, ambient monitoring will be
required. Finally, the additional analysis considers the impact on
soils, vegetation, and visibility in the affected area from the
increased emissions.
The applicant now has conducted the required analyses and based on
the results proposes BACT to the reviewing agency that has responsibility
for approval. The reviewing agency's determination is made on a case-by-
case basis and the emission rates proposed as BACT may not necessarily
be the rate ultimately specified in the PSD permit.
7.2.3 NESHAP Delegation to States
Section 112(d)(l) of the CAA allows each state to develop and
submit to the Administrator a procedure for implementing and enforcing
emission standards for hazardous air pollutants for sources in their
state. If the Administrator finds the state procedure adequate, he
shall delegate to the state the authority under the CAA to implement and
enforce the NESHAP standards. Currently, those states that have received
NESHAP delegation that contain VC sources are Texas, Georgia, and
California. The state program must be as least as stringent as the
Federal VC NESHAP. The state can also develop a program that is more
stringent. California has developed a more progressive program that
exemplifies the effect that NESHAP delegation can have on reducing VC
emissions below those levels required by the Federal VC NESHAP.
The California Air Resources Board (CARB) was delegated NESHAP
authority and, in response, adopted a state ambient air quality standard
(AAQS) for VC of 10 parts per billion (ppb). CARB chose the 10 ppb
level as the state AAQS because it was the lowest detectable limit for
VC at that time. Responsibility for implementing the standard was then
delegated to the local Districts (county-wide areas) within California.
The Districts' mandate is to attain and maintain the AAQS's adopted by
California, although the Districts' rules and regulations apply
specifically to the sources within their jurisdiction.
All of the five VC sources in California are located in the South
Coast Air Quality Management District (SCAQMD). In response to the
7-7
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10 ppb AAQS, SCAQMD adopted the Federal NESHAP (Rule 1005) as their
authority for enforcement of the AAQS and proposed a resolution adopting
Rule 1005.1 as their program for controlling VC emissions to 10 ppb.
Some of the major differences between Rule 1005.1 and the Federal NESHAP
will be discussed in the following subsections.
Ambient monitoring. Designated plants, or those plants subject to
Rule 1005.1, are not allowed to discharge VC in quantities that result
in ambient concentrations greater than 10 ppb, 24-hour average, measured
at any point beyond the property line of the plant where people reside
and work. Sources are required to operate up to eight air monitoring
stations in the vicinity of the plant to ensure that the 10 ppb level is
being attained. These stations are selected and approved based on
meteorological data, other available monitoring data, and location of
populations around the plant. Meteorological data must also be
monitored at these stations. Records of all the data must be maintained
and monthly summaries submitted to SCAQMD. A plant can reduce the
number of required stations if no violations occur in any period of 6
consecutive months. This exemption becomes void if a significant
violation occurs. Minor, nonperiodic and infrequent breakdowns may be
overlooked.
Primary control device. All equipment containing more than 10 ppm
VC is required to be vented to the primary control device. The control
device must then be operated at an efficiency to limit total emissions
from the stack to less than 50 grams per hour. Selection of the emission
limit was based on worst case modeling indicating that this level of
emissions would maintain the 10 ppb AAQS. The 50 gram per hour limit
sets a ceiling on growth (which the VC NESHAP 10 ppm limit does not;
plants can continue to grow and discharge larger quantities of VC under
the 10 ppm Federal standard).
Bubble concept. Rule 1005.1 allows a source to "bubble" or group
their emissions to the degree that the 50 gram per hour limit is
maintained. If a source requests this method of emissions reduction,
all original construction and operation permits must be submitted to
SCAQMD and new permits filed for approval. SCAQMD reissues these permits
specifying emission levels or any other conditions necessary to ensure
all emission limits are met.
7-8
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Reactor opening loss (ROL). ROL emissions have been reduced to a
10 ppm concentration rather than the Federal standard of 0.02 gram VC
per kilogram of PVC produced.
Operational Requirements. All vent valves and relief devices
(other than emergency relief valves) upstream of stripping must be
vented to a receiving vessel. Off-specification polymer batches must be
discharged to a sealed container or stripped to required levels. Failure
of a rupture disc preceding an emergency relief valve is a violation
unless vented to control equipment.
Management plan. A management plan must be submitted for the
reduction of VC emissions. The plan should include, but is not limited
to,
• A plan and schedule to locate and identify all emissions
sources that may cause the AAQS to be exceeded;
• An outline of employee training programs for preventing
emissions;
• A method for screening operating data to identify operators
most often responsible for excessive emissions; and
• An outline of a special training program or other methods to
eliminate excessive emissions.
Leak detection. A leak is the detection of VC from any location,
other than a stack vent or designed equipment opening, from which VC
exceeds the background level of 10 ppm (measured 5 centimeters from
source). All equipment containing or using VC shall be free of leaks.
Equipment is to be inspected on a regular basis and records kept - all
leaks are to be eliminated within 24 hours. Any leak detected during a
SCAQMD inspection is a violation.
New or modified plants. The builder must demonstrate that the
ambient air quality will not exceed the 10 ppb AAQS as a result of any
emission from a new or modified source.
Relief valve discharges. Designated plants must install and operate
pressure indicating and recording instruments (or approved equivalents)
monitoring the discharge of emergency relief valves and manual vent
valves. Data from these instruments must be summarized monthly and
submitted to SCAQMD.
7-9
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Current status of Rule 1005.1. The above subsections represent a
summary of the major differences between the Federal NESHAP and the
SCAQMD Rule 1005.1. Rule 1005.1 is currently being challenged in court
by Stauffer Chemical and the B.F. Goodrich Chemical Group on the basis
that the Rule is unconstitutional.
7.3 RESOURCE CONSERVATION AND RECOVERY ACT (RCRA)
RCRA was established in 1976 for the protection of public health
and welfare by supplying guidelines to protect the quality of ground-
water, surface water, and ambient air from contamination by solid waste.
Draft regulations were issued in 1978 and final regulations in May 1980.
These regulations control hazardous wastes from "cradle-to-grave" or
from the point of generation through transportation, storage and ultimate
disposal. This will be accomplished by a manifest system. If the
generator produces hazardous wastes in sufficient quantities (greater
than 1,000 kilograms per calendar month, except for some highly toxic
wastes with lower limits of 1 kilogram per calendar month), he is
responsible for their disposal. On-site disposal will require a permit
with strict requirements for siting, operating, and monitoring the
facility. Otherwise, the waste must be disposed of in a facility with a
permit subject to the same strict requirements. The generator remains
responsible for off-site disposal.
RCRA will probably have more of an effect on EDC/VC plants than PVC
plants. The following EDC/VC processes have been identified as sources
of hazardous wastes (EPA, 1979b, p. 181), 1) heavy ends from distillation
of VC in production of VC from EDC, 2) heavy ends from distillation of
EDC in VC production, and 3) heavy ends from distillation of EDC in EDC
production. PVC sludge is not designated as a hazardous waste.
These solid wastes have been specifically listed as hazardous but
it will still be the responsibility of the generator to show that other
solid wastes originating from his facility are not hazardous. VC has
been identified as a pollutant that could cause a solid waste to be
classified hazardous (EPA, 1979b, p. 175). Also, surface impoundments,
utilized by EDC/VC and PVC plants to collect waste streams, represent
disposal sites and may require upgrading to meet RCRA standards of
performance (Hanrahan, 1979, p. 23).
7-10
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One of the more common methods being proposed for disposal of
hazardous wastes is incineration. RCRA has extensive permit requirements
for direct land disposal plus long term liabilities for generators using
this method. However, incineration disposes of wastes without pretreatment
and without incurring the long term liabilities of the manifest system.
EDC/VC plants or PVC plants incinerating their hazardous wastes will be
required to obtain a permit to operate the incinerator under RCRA.
7.4 TOXIC SUBSTANCES CONTROL ACT (TSCA)
TSCA was enacted in 1976 and provides EPA with the authority to
secure information on all new and existing chemical substances and to
control the substances determined to be hazardous to public health and
the environment. Basically, TSCA was instituted to control the commerce
of toxic products and the regulations provide EPA with powers that do
not exist under any other Federal toxics-related laws. The other environ-
mental laws (e.g., Clean Air Act, Clean Water Act, RCRA) are concerned
with the control and disposition of gaseous, liquid and solid wastes and
byproducts. OSHA focuses directly on worker exposure problems. However,
TSCA deals with chemicals and products throughout their life cycle -
manufacturing, distribution, use, and disposal (EPA, 1979b).
EPA will control the chemicals by requiring submission of a
Premanufacture Notification (PMN) before marketing a new substance not
listed in the TSCA 1979 Inventory of Toxic Substances. The PMN contains
extensive background information including test data and literature
predicting the effect that substances may have on workers, the
environment, and consumer populations. Exceptions to TSCA are foods,
drugs and pesticides that must be registered with specific agencies
(e.g., FDA for foods and drugs, and EPA for pesticides). Any chemicals
in the 1979 Inventory that are released to the environment by discharge
must be listed in any state permits (to construct and operate), RCRA
permits, and National Pollutant Discharge Elimination System (NPDES)
permits under the Clean Water Act.
EDC, VC and many polymers of VC are already listed in the Inventory,
and public health and environmental effects have been well established
for these substances. A PMN is not required unless the "old" or listed
7-11
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substance is used in a significantly new way (as determined by EPA).
However, any new chemicals used in polymer development (e.g., new
copolymers containing VC) will require a PMN prior to marketing.
7.5 CLEAN WATER ACT
Section 307 of the Clean Water Act required the EPA to publish a
list of toxic pollutants and authorized EPA to promulgate effluent
standards for those pollutants. In addition to these listed toxic
pollutants, amendments to the Clean Water Act in 1977 required that
"Consent Decree Pollutants" be added to the list of toxic pollutants if
effluent limits failed to achieve water quality criteria (EPA, 1979b).
VC is one of these "Consent Decree Pollutants" for which effluent guide-
lines were developed (see Federal Register, Nov. 28, 1980; 45 FR 79318).
These effluent limitations are listed on, and enforced through, the
discharge permit required under the National Pollutant Discharge
Elimination System (NPDES).
Section 311 entitled "Oil and Hazardous Substance Liability,"
authorizes EPA to promulgate Hazardous Spill Regulations. Under these
regulations EPA designated as hazardous those substances which, when
discharged, present an imminent and substantial danger to the public
health or welfare. An additional 28 chemicals have been added to the
existing list of 271 hazardous substances published in 1978 — ethylene
dichloride (EDC) used to produce VC and vinylidene chloride (used as a
comonomer with VC) are on the proposed list (EPA, 1979b). Any spill
consisting of these chemicals would result in a penalty, which is
determined on a case-by-case basis. Sources in compliance with effluent
standards established for these chemicals in other sections of the Clean
Water Act are exempt from these requirements.
7.6 SAFE DRINKING WATER ACT
The Safe Drinking Water Act of 1974 was established to ensure that
the public is provided with safe drinking water. This protection of
public health is accomplished by EPA through the adoption of National
Interim Primary Drinking Water Regulations that specify maximum levels
for certain toxic contaminants in public drinking water. Secondary
drinking water regulations have been proposed as guidelines to the
states to ensure non-health related qualities of drinking water.
7-12
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As a guideline, a list of chemicals indicative of industrial
pollution has been published by EPA — VC is one of these indicators
(EPA, 1979b). In addition, the EPA Office of Drinking Water, Criteria
and Standards Division, has drafted a criteria document that would be
used to establish a drinking water standard for VC.
7.7 HAZARDOUS MATERIALS TRANSPORTATION ACT
The Department of Transportation (DOT) under the Hazardous Materials
Transportation Act of 1974 has promulgated final regulations on the
transport of hazardous wastes and hazardous substances. VC, EDC, and
several comonomers are subject to these regulations. The principal
objective of this rule, as it pertains to the use of identification
numbers for the regulated substances, is to improve the efficiency of
civil emergency personnel (such as firemen and policemen) in the
identification of hazardous materials, and to facilitate the accurate
transmission of information to and from the scenes of accidents involving
hazardous materials.
7.8 OCCUPATIONAL SAFETY AND HEALTH ACT
OSHA recently published a request for information on VC and PVC in
the Federal Register on December 18, 1979 (44 FR 74928). This request
was for voluntary submission of data and information that could be used
as part of a review of the current OSHA VC standard. OSHA is concerned
primarily with PVC dust and that the dust might cause pneumoconiosis.
OSHA is investigating to determine whether the disease is caused by
residual levels of VC in the dust or by the actual dust itself. The
progress of this investigation has not been determined to date.
7.9 SUPERFUND LEGISLATION
The Comprehensive Environmental Response, Compensation and Liability
Act of 1980 (Superfund) was recently signed into law to further the
control of hazardous substances in the environment. The purpose of
superfund is to:
• establish a federal cause of action against those responsible
for the release of a hazardous substance into the environment;
• create a $1.6 billion trust fund to be used for cleaning up
hazardous substances released into the environment or for
taking action to prevent a threatened release; and
7-13
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• create a $200 million fund for surveillance, care and
maintenance of RCRA-closed hazardous substance disposal sites,
and for any damages or environmental cleanup costs associated
with such a site.
The $1.6 billion cleanup fund will be created from $1.38 billion in
industry taxes and $0.22 billion in government revenues. The $200 million
surveillance, care and maintenance fund will be created from industry
taxes. These taxes will be on crude petroleum products, chemicals
produced, and hazardous wastes generated. Regulations for implementing
the superfund will be promulgated in the near future.
7.10 FOOD AND DRUG ADMINISTRATION REGULATIONS
The Food and Drug Administration (FDA) establishes requirements for
PVC resins fabricated into products that come into human contact (e.g.,
beverage containers, baby bottle nipples, blood bags, pharmaceutical
products, and food wrap). A processor producing these resins must meet
requirements specifying operational procedures, resin characteristics
(e.g., clarity, purity), and residual levels of VC (RVC). The FDA puts
restrictions on all process steps from polymerization through
fabrication. These resins are usually small-batch specialty resins that
are stripped under controlled conditions because of their heat
sensitivity. Also, reactors must be maintained differently (e.g.,
cleaning requirements are specified) and frequency of reactor opening is
dictated.
7.11 OTHER STATE AND LOCAL REGULATIONS
The state regulations having the greatest impact on reducing VC
emission are those mentioned previously under the Clean Air Act. Prior
to construction or modification of a source and subsequent operation,
companies will be required to obtain permits to construct and operate.'
It is through these permits that states will set limitations and
conditions for emission reduction in nonattainment areas. These
limitations may require further reduction of VC emissions below NESHAP
limits, either through a reduction in hydrocarbons or VC specifically.
7-14
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7.11 REFERENCES FOR CHAPTER 7
Brittain, Martin. 1980. NESHAP Coordinator, EPA Region VI. Meeting Report.
July 23, 1980.
Environmental Protection Agency. 1979(a). "National Emission Standards for
Identifying, Assessing and Regulating Airborne Substances Posing a
Risk of Cancer," Proposed Rules, Federal Register. Vol. 44, No. 197.
October 10, 1979(a).
Environmental Protection Agency. 1979(b). A Handbook of Key Federal Regulations
and Criteria for Multimedia Environmental Control. EPA-600/7-79-175.
August 1979(b).
Environmental Protection Agency. 1975. Standard Support and Environmental
Impact Statement: Emission Standard for Vinyl Chloride, EPA-450/
2-75-009. October 1975.
Hanrahan, David. 1979. "Hazardous Wastes: Current Problems and Near-Term
Solutions," Technology Review. November 1979.
Hoi brook, W.C. 1980. Director Toxicology and Environmental Affairs,
B.F. Goodrich Chemical Division. Meeting Report: B.F. Goodrich,
General Tire and TRW representatives. October 30, 1980.
Winkler, Joe. 1980. Technical Support Section, EPA Region VI. Preliminary
Determination for Formosa Plastics Company, PSD-TX-226. February 22,
1980.
7-15
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APPENDIX A
VINYL CHLORIDE NATIONAL EMISSIONS STANDARD FOR HAZARDOUS AIR POLLUTANTS
-------
TKto 4O—Protection of Environment
CHAPTER 1—ENVIRONMENTAL
PROTECTION AGENCY
SUBCHAFTCft C—AIM PMOQMAMS
PART 61—NATIONAL EMISSION STAND-
ARDS FOR HAZARDOUS AIR POLLUTANTS
81.01
11.09
81.04
fl.06
81.08
tun
tl.0»
61.10
•1.11
01.13
•US
•1.18
81.17
Applicability.
Definition*.
Abbreviations.
Address.
Prohibit*! activities.
Determination, of construction or
modification.
Application for approral of construo-
tion or modification.
Approval by Administrator.
Notification of startup.
Sourc* reporting and waiver request.
Walvtr of compliance.
Emission testa and monttortnf.
WalTer of emission tests.
Soon* tot and analytical methods.
Availability of Information.
Stau authority.
Circumvention.'
l«*p»rt» M«U«ii«l Einlesls)
Asttsstoi
61.30 AppllcabDlty.
81 Jl Definition!.
•1.33 Emission standard.
61.23 Air-cleaning.
•1.34 Reporting.
81M Waste disposal sites.7
BwyOlum
•1M Applicability.
81J1 Definitions.
01.32 Emission standard.
8133 Stack sampling.
•1.34
81.83 Kmlulon nandard for Tlnyl chloride
plants.
01.84 Emission standard lor polyvlnyl chlo-
ride plants.
81.8S Emission standard for ethylene dl-
chlortde, vinyl chloride and poly-
vinyl chloride plants.
61.68 Equivalent equipment and procedures.
61.67 Emission tests.
61.88 Emission monitoring.
61 89 Initial report.
61 70 Semiannual report.
61.71 Rccordkeeplng.
Appendix A—Compliance Status Information.
Appendix B—Test Methods.
Method 101—Reference method for determi-
nation of paniculate and gaseous mercury
emissions from stationary sources (air
streams).
Matted 103—Reference method for determi-
nation of paniculate and gaseous mercury
emissions from stationary sources (hydro-
gen streams).
Method 103—Beryllium screening method.
Method 104—Reference method for determi-
nation of beryllium emissions from sta-
tionary sources.
Method 106—Method for determination of
mercury In wastewater treatment plant
sewage sludges.'
Method 106—Determination of vinyl chloride
from stationary sources. *•
Method 107—Determination of vinyl chloride
of Inprocess wastewater samples, and vinyl
chloride content of polyvlnyl chloride
resin, slurry, wet cake, and latex samples.2"
Aumoarrr Sec. 112. JOKa) of the Clean
Air Act a* amended [42 U.S.C. 1412.
7Ml(a)l. unless otherwise noted.
tubeeit O—Nettonel bnlnlon Stondsrt fe>
Beryllium Rocket Motor Firing
•1.40 Applicability.
61.41 Definitions.
61.43 Emission standard.
fll.41 emission testing—rocket nring or pro-
pellant disposal.
H.44 Stack sampling.
Subpert I—National Imleeien ttandanl ft*
MsreniT
81 JO Applicability.
81 Jl Definitions.
81J3 Smlsalon standard.
81 .S3 Stack sampling.
81.44 Sludge sampUag.'
61M Emission monitoring.7
Subpart F—Netlonel Cmlssl«
-------
Subpart A—Omiwil Provteloni
161.01 Applicability.
The provisions of this part apply to
the owner or operator of any stationary
source for which a standard is prescribed
under this part
g 61.02 Definition*.
As used In this part, all terms not de-
fined herein shall have the meaning given
them lr. the act:
(a) "Act" means the Clean Air Act (42
U.S.C. 1857etseq.).
"Administrator" means the Ad-
ministrator of the Environmental Pro-
tection Agency or his authorized repre-
sentative. _
(c) "Alternative method" means any
method of sampling and analyzing for
an air pollutant which is not a reference
method or an equivalent method but
which has been demonstrated to the
Administrator's satisfaction to produce.
In specific cases, results adequate for
his determination of compliance.3
(d) "Commenced" means that an own-
er or operator has undertaken a con-
tinuous program of construction or
modification or that an owner or operator
has entered Into a contractual obligation
to undertake and complete, within a rea-
sonable time, a continuous program of
construction or modification.
(e) "Compliance schedule" means the
date or dates by which a source or cate-
gory of sources Is required to comply with
the standards of this part and with any
steps coward such compliance which are
set forth In a waiver of compliance under
161.11.
"Equivalent method" means any
method of sampling and analyzing for
an air pollutant which has been demon-
strated to the Administrator's satisfac-
tion to have a consistent and quantita-
tively known relationship to the reference
method, under specified conditions.
(1) "Existing source" means any sta-
tionary source which Is not a new source.
til "Modification" means any physical
change In. or change In the method of
operation of. a stationary source which
Increases the amount of any hazardous
air pollutant emitted by such source or
which results In the emission of any
hazardous air pollutant not previously
emitted, except that:
(1) Routine maintenance, repair, and
replacement shall not be considered
physical changes, and
<2> The following shall not be con-
sidered a change in the method of
operation:
(I) An Increase In the production rate.
If nich Increase does not exceed the op-
erating design capacity of the stationery
source;
(II) An Increase in hours of operation.
Ik) "New source" means any stationary
source, the construction or modification
of which Is commenced after the publi-
cation In the FIDEXAL Rscism of pro*
posed national emission standards for
hazardous air pollutants which will be
applicable to such source.
(1) "Owner or operator" means any
person who owns, leases, operates, con-
trols, or supervises a stationary source.
'm> "Reference method" means any
method of sampling and analyzing for an
air pollutant, as described In Appendix
B to this part.
(n) "Startup" means the setting In
operation of a stationary source for any
purpose.
(o) "Standard" means a national
emission standard for a hazardous air
pollutant proposed or promulgated under
this part.
liter
OBsounces
pal(=pounds per sqnan Inch cage
•a=degree Banklmt
*l=mlcnUt*rslO-* Uter
T/v=Toluma par volume
Td'=aquare yard*
yr=year
Be= beryllium
Hg= mercury
8,0= water
(d) Miscellaneous:
act=actual
avg= avenge
LD.= Inside dlame*.«r
M = molar
N = normal
O.D.= outside diameter
% = percent
std=standard
(Section* 113 and SOI (a) of the Clean Air
Act. as amended 1*3 C.S.C. lSJIc-7.
1857«a)).)
§ 61.04 Address.4
(a) All requests, reports, application!,
submlttals. and other communications to
the Administrator pursuant to this part
shall be submitted In duplicate and ad-
dressed to the appropriate Regional Of-
fice of the Environmental Protection
Agency, to the attention of the Director,
Enforcement Division. The regional of-
fices are as follows:
Region I (Connecticut, Maine, New Hamp-
shire. Massachusetts. Rhode Island, Ver-
mont), John P. Kennedy Federal Building,
Boston, Msmschusetts 03303.
Region II (New York, New Jersey. Puerto
Rico, Virgin Islands), Federal Office Build-
ing. 28 Federal Plaza (Foley Square) New
York. N.T. 10007.
Region m (Delaware. District of Columbia.
Pennsylvania. Maryland. Virginia, West Vir-
ginia). Curtis Building. Sixth and Walnut
Streeta, Philadelphia. Pennsylvania 19108.
Region IV (Alabama. Florida, Georgia. Mis-
sissippi, Kentucky, North Carolina South
Carolina, Tennessee), Suite 300. 1421 Peach-
tree Street. Atlanta, Georgia 30308.
Region V (nilnots. Indiana, Minnesota.
Michigan. Ohio. Wisconsin I. 230 Southnear-
born Street. Chicago. Illinois 60604.*3'
Region VI (Arkansas. Louisiana, New
Mexico. Oklahoma, Texas). 1800 Patterson
Street. Dallas. Texas 75201.
Region vn (Iowa, Kansas. Missouri. Ne-
braska) , 1735 Baltimore Street. Kansas City.
Missouri 93108.
Region vm (Colorado, Montana, North Da-
kota. South Dakota, Utah, Wyoming), 188
Lincoln Towers, 1800 Lincoln Street, Denver.
Colorado 80303.
Region IX (Arizona, California, Hawaii.
Nevada, Guam. American Samoa), 100 Cali-
fornia Street. San Francisco. California Mill.
Region X (Washington, Oregon, Idaho
Alaska). 1200 Sixth Avenue, Seattle Waab-
tngton 98101.
(b) Section 112(d) directs the Admin-
istrator to delegate to each State, when
appropriate, the authority to Implement
and enforce the national emission stand-
ards for hazardous air pollutants for sta-
tionary sources located In such State.
All Information required to be submitted
to EPA under paragraph (a) of this sec-
tion, must also be submitted to the ap-
propriate State Agency of any State to
which this authority has been delegated
(provided, that each specific delegation
may exempt sources from a certain fed-
eral or State reporting requirement). The
appropriate mailing address for those
States whose delegation request hu been
approved Is a* follows:
A-2
-------
l A) | Reserved)
IB) State or Alabama, Air Pollution Con-
ol Division, Air Pollution Control Commis-
sion. 845 S McDonougb Street. Montgomery.
Alabama 38104."
(01 (Reserved!
(Di Arizona-
Plma County Air Pollution Control Dis-
trict. 151 West Congress Street, Tucson AZ
85701.30
(E) [Reserved)
,P, California *.«.».».«.»«« 31
Bay Area Air Pollution Control District,
939 Ellis Street. San Francisco. CA 94109.
Del Norte County Air Pollution Control
District Courthouse. Crescent City. CA 95531.
Fresno County Air Pollution Control Dis-
trict. 515 S Cedar Avenue. Fresno. CA 93702.
Humboldt County Air Pollution Control
District. 5600 S. Broadway. Eureka. CA 95501.
Kern County Air Pollution Control Dis-
trict, 1700 Plower street (P.O. Box 997)
Bakersneld. CA 93302.
Madera County Air Pollution Control Dis-
trict. 139 W. Ycsemlte Avenue. Madera. CA
93637
Mendoclno County Air Pollution Control
District, County Courthouse. Uklah. CA
96482
Monterey Bay Unified Air Pollution Con-
trol District. 420 Church Street (P.O. Box
487). Salinas. CA 93901.
Northern Sonoma County Air Pollution
Control District. 3313 Chanate Road. Santa
Rosa. CA 95404
Sacramento County Air Pollution Control
District. 3701 Branch Center Road. Sacra-
mento. CA 95827
San Diego County Air Pollution Control
District. 9150 Chesapeake Drive. San Diego.
CA 92123
San Joaquln County Air Pollution Control
district. 1601 E Hnzelton Street (P.O. Box
J009}. Stockton. CA 09201.
Santa Barbara Air Pollution Control Dis-
trict. 4440 Calle Real. Santa Barbara. CA
93110.
Stanislaus Countv Air Pollution Control
District. 820 Scenic Drive. Modesto. CA 95350.
Tnnltv Countv Air Pollution Control Dis-
trict. Box AJ. Weavervllle. CA 96093
Ventura Countv Air Pollution Control Dis-
trict. 625 E. Santa Clara Street. Ventura. CA
93001.
(O) State of Colorado. Colorado Air Pol-
lution Control Division. 4210 East nth Ave-
nue. Denver. Colorado 80220. *
(HI State of Connecticut. Department
of Environmental Protection. State Office
Bulldlne. Hartford. Connecticut 06115.
(I) State of Delaware (for foaill fuel-fired
•team generators: Incinerators: nitric acid
pUnu: asphalt concrete planu: iterate ves-
•els for petroleum liquids: and sewage treat-
ment plant* only): Delaware Department of
Natural Resource* and Environmental Con-
trol. Edward Tatnall Building, Dover. Del.
(TJ) State of Maine. Department of En-
vironmental protection. State House, Au-
gusta. Maine 04330.'1
(V) (Reserved)
(VI) Massachusetts Department of Envi-
ronmental Quality Engineering. Division of
Air Quality Control. 600 Washington Street.
Boston. Massachusetts 02111.17
(X) State of Michigan. Air Pollution Con-
trol Division. Michigan Department of Natu-
ral Resources. Stevens T. Mason Building.
8th Floor, Lansing. Michigan 48926."
(T) Minnesota Pollution Control Agency.
Division of Air Quality', 1B38 West county
Road B-2. RoaevUle. Minn. &5113.**
> Z l I Reserved ]
lAA) I Reserved |
CBB) Mate of laoatana. Department of
Bealtb and Environmental Science*, Cogs-
well Building, Helena, lion*. 69801. *J
(*)-(K) (Reserved!
(L) State of Oeorgla. Environmental Pro-
tection Division. Department of Natural Re-
sources. 270 Washington Street. S.W.. At-
lanta. Oeorgla 30334."
(M)-(O) | Reserved I
(P) State of Indiana. Indiana Air Pollu-
tion Control Board. 1330 West Michigan
Street, Indianapolis. Indiana 48208.'"
(Q)-(«) [Reserved)
(B) Division of Air Pollution Control. De-
partment for Natural Resource*) and Envi-
ronmental Protection, DA 117. Frankfort,
Ky. 40601.«
(T) I reserved |.
(EE) New Hampshire Air Pollution Con-
trol Agency. Department of Health and We).
rare. State Laboratory Building, Hazen Drive.
Concord, New Hampshire 03301.''
(FP)—State of New Jersey: New Jersey De-
partment of Environmental Protection,
John Pitch Plaza. P.O. Box 2807. Trenton.
New Jersey 08825,39
lOG) | Reserved |
l KH) New York: New York State Depart-
ment of Environmental Conservation. 60 Wolf
Road. Albany, New York 12233. attention:
Division of Air Resources.8
i II) North Carolina Environmental Man-
agement Commission. Department of Natural
and Economic Resources. Division of Envi-
ronmental Management. P.O. Box 27687, Ra-
leigh. North Carolina 27611. Attention: Air
Quality Sec lion.3*
IJJl State of North Dakota. State De-
partment or Health. State Capitol. Bismarck,
North Dakota 58501 i~
(KK)-(LLi (Reserved!
l MM) State or Oregon, Department of
Environmental Quality. 1934. SW Morrison
Street. Portland. Oregon 97808."
(NN)(a) Commonwealth of Pennsylvania
(except for City of Philadelphia and Alle-
gheny County i Pennsylvania Department of
Environmental Resources. Bureau of Air
Quality and NolYe Control. Post Office Box
2063. Harrisburg. Pennsylvania 17120.
(b) City of Philadelphia. Philadelphia De-
partment of Public Health Air Management
Services. 801 Arch Street. Philadelphia. Penn-
sylvania 19107. 35
IOO) [Reserved!
(PP) State of South Carolina. Offlce of En-
vironmental Quality Control. Department
of Health snd Environmental Control. 2800
Bull Street. Columbia. South Carolina 29201?*
IQQ)-(TT) (ReservedI
1UU) State of Vermont. Agency of Envi-
ronmental Protection. Box 489. Montpeller,
Vermont 05602.33
(W) Commonwealth of Virginia. Virginia
State Air Pollution Control Board, Room
1106. Ninth Street Office Building. Richmond.
Virginia 23219.1'
(WW) (l) Washington: state of Waahlng-
ton. Department of Ecology. Olympla. Wash-
ington 08604.
(11) Northwest Air Pollution Authority.
207 Pioneer Building. Second and Pin*
Streets. Mount Vernon. Washington 98278.
(Ill) Puget Sound Air Pollution Control
Agency. 410 West Harrison Street. Seattle.
Washington 98119.
(iv) Spokane County Air Pollution Con-
trol Authority. North 811 Jefferson, Spokane.
Washington 99301.
(v) Yaklma County Clean Air Authority,
Countv Courthouse. Yaklma. Washington
98B01. *.W
(vl) Olympic Air Pollution Control Au-
thority, 120 East State Avenue. Olympla.
Washington 98501.
(vil) Southwest Air Pollution Control Au-
thority. Suite 7801 B, NE Hazel Dell Avenue.
Vancouver. Washington 98665.13
(XX) (Reserved!
IYY1 Wisconsin—Wisconsin Department
or Natural Resources PO Box 7921. MaBi-
son. Wisconsin 53707 3'
l ZZ i 1 Reserved I
l AAAI | Reserved I
(BBB)—Commonwealth o( Puer.o Rico
Commonwealth of Puerto Rico Environ-
mental Quality Board. P.O Bov 11786 Sasi-
turce.PR 00910w
ICCC) U.S. Virgin Islands: U.S virgin
Islands Department or Conservation and
Cultural Affairs. P.O. Box 578. Charlotte
Amalle, St. Thomas. VS. Virgin Islands
00801. M
(Sees. 101. 110. 111. 112 and 301 of the Clean
Air Act. » amended. 42 U.S.C. 18S7. ISSTc-
5. 6. 7 and I857g.)
A-3
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§ 61.05 Prohlblird aetlvitie*.
(a) After the effective date of any
standard prescribed under this part, no
owner or operator shall construct or mod-
ify any stationary source subject to such
standard without first obtaining written
approval of the Administrator In accord-
ance with this subpart, except under an
exemption granted by the President
under section 112 (c) (2) of the act.
Sources, the construction or modification
of which commenced after the publica-
tion date of the standards proposed to
be applicable to such source, are subject
to this prohibition.
(b) After the effective date of any
standard prescribed under this part, no
owner or operator shall operate any new
source In violation of such standard ex-
cept under an exemption granted by the
President under section 112(c) (2) of the
ict.
(c) Ninety days after the effective date
of any standard prescribed under this
part, no owner or operator snail operate
any existing stationary source In viola-
tion of such standard, except under a
waiver granted by the Administrator In
accordance with this subpart or under
an exemption granted by the President
under section 112(c) (2) of the act.
(d) No owner or operator subject to
the provisions of this part shall fail to
report, revise reports, or report source
test results as required under this part.
I 61.06 Determination of coiulmetlon
or modification.
Upon written application by an owner
or operator, the Administrator will make
a determination of whether actions taken
or Intended to be taken by such owner
or operator constitute construction or
modification or the commencement
thereof within the meaning of this part.
The Administrator will within 30 days
of receipt of sufficient information to
evaluate an application, notify the owner
or operator of his determination.
} 61.07 Application for approval of
coiulruclion or modification.
(a) The owner or operator of any new
source to which a standard prescribed
under this part Is applicable shall, prior
to the date on which construction or
modification Is planned to commence, or
within 30 days after the effective date
In the case of a new source that already
has commenced construction or modifi-
cation and has not begun operation, sub-
mit to the Administrator an application
for approval of such construction or
modification. A separate application shall
be submitted for each stationary source.
(b) Each application shall include:
(1) The name and address of the ap-
plicant.
(3) The location or proposed location
of the source.
(3) Technical Information describing
the proposed nature, size, design, operat-
ing design capacity, and method of oper-
ation of the source. Including a descrip-
tion of any equipment to be used for
control of emissions. Such technical In-
formation shall Include calculations of
emission estimates In sufficient detail to
permit assessment of the validity of such
calculations.
I 61.08 Approval bj Administrator.
(a) The Administrator will, within 80
days of receipt of sufficient information
to evaluate an application under 9 81.07.
notify the owner or operator of approval
or intention to deny approval of con-
struction or modification.
(b) If the Administrator determines
that a stationary source for which an
application pursuant to § 61.07 was sub-
mitted will. If properly operated, not
cause emissions in violation of a stand-
ard, he will approve the construction or
modification of such source.
(c) Prior to denying any application
for approval of construction or modifica-
tion pursuant to this section, the Admin-
istrator will notify the owner or operator
making such application of the Admin-
istrator's Intention to Issue such denial.
together with:
(1) Notice of the information and
findings on which such Intended denial
Is based, and
(2) Notice of opportunity for such
owner or operator to present, within such
time limit as the Administrator shall
specify, additional Information or argu-
ments to the Administrator prior to final
action on such application.
(d> A final determination to deny any
application for approval will be In writ-
ing and will set forth the specific grounds
on which such denial Is based. Such final
determination will be made within 60
days of presentation of additional infor-
mation or arguments, or 60 days after
the final date specified for presentation.
If no presentation Is made.
(e) Neither the submission of an ap-
plication for approval nor the Admin-
istrator's granting of approval to con-
struct or modify shall:
(1) Relieve an owner or operator of
legal responsibility for compliance with
any applicable provision of this part or
of any other applicable Federal. State.
or local requirement, or
(2) Prevent the Administrator from
Implementing or enforcing this part or
talcing any other action under the act.
g 61.09 Notification of stamp.
(a) Any owner or operator of a source
which has an Initial startup after the
effective date of a standard prescribed
under this part shall furnish the Admin-
istrator written notification as follows:
(1) A notification of the anticipated
date of initial startup of the source not
more than 60 days nor less than 30 days
prior to such date.
(2) A notification of the actual date
of '"'«»' startup of the source within IS
days after such date.
(See. 114 of to* CTnui Air Act ai
<41 UJS.C. T414». «*"
3 61.10 Source reporting and waiver re*
quoit.
(a) The owner or operator of any
existing source, or any new source to
which a standard prescribed under this
part is applicable which had an initial
startup which preceded the effective date
of a standard prescribed under this part
shall, within 90 days after the effective
date, provide the following information
In writing to the Administrator:
(1) Name and address of the owner
or operator.
(2) The location of the source.
(3) The type of hazardous pollutants
emitted by the stationary source.
(4) A brief description of the nature.
size, design, and method of operation of
the stationary source Including the op-
erating design capacity of such source.
Identify each point of emission for each
hazardous pollutant.
(5) The average weight per month of
the hazardous materials being processed
by the siiirce, over the last 13 months
preceding the date of the report.
(6) A description of the existing con-
trol equipment for each emission point.
(1) Primary control device(s) for eaer,
hazardous pollutant.
(11) Secondary control devlce(s) for
each hazardous pollutant.
(1U) Estimated control efficiency (per-
cent) for each control device.
(7) A statement by the owner or oper-
ator of the source as to whether he can
comply with the standards prescribed In
this part within 90 days of the effective
date.
(b) The owner or operator of an exist-
ing source unable to operate In compli-
ance with any standard prescribed under
this part may request a waiver of com-
pliance with such standard for a period
not exceeding 2 years from the effective
date. Any request shall be in writing and
shall Include the following information:
(1) A description of the controls to
be installed to comply with the standard.
(2) A compliance schedule, including
the date each step toward compliance will
be reached. Such list shall include as a
minimum the following dates:
(1) Date by which contracts for emis-
sion control systems or process modifica-
tions will be awarded, or date by which
orders will be Issued for the purchase
of component parts to accomplish emis-
sion control or process modification:
(11) Date of initiation of onalte con-
struction or installation of emission con-
trol equipment or process change:
(111) Date by which onsite construc-
tion or installation of emission control
equipment or process modification 1* to
be completed: and
(iv) Date by which final compliance U
A-4
-------
to be achieved.
(I) A description of interim emission
control steps which will be taken during
the waiver period.
(e) Changes in the Information pro-
Tided under paragraph (a) of toll section
•hall be provided to the Administrator
within 30 days after such change, except
that if changes will result from modifica-
tion of the source, as defined In I 61.03
(]), the provisions of I 81.07 aad I 81.08
are applicable.
(d) The format for reporting under
this section is included as Appendix A of
this part. Advice on reporting the status
of compliance may be obtained from the
Administrator.
(•be. 114 at UM Clean Air Act is
(41 O.S.C. 14U». *MT
|61.11 Waiver of compliance.
(a) Based on the Information provided
In any request under I 61.10. or other In-
formation, the Administrator may grant
a waiver of compliance with a standard
for a period not exceeding 2 years from
the effective date of such standard.
(b) Such waiver will be In writing and
will:
(1) Identify the stationary source
covered.
(2) Specify the termination date of
the waiver. The waiver may be termi-
nated at an earlier date if the conditions
specified under paragraph (b) (3) of this
section are not met.
(3) Specify dates by which steps to-
ward compliance are to be taken; and
Impose such additional conditions as the
Administrator determines to be neces-
sary to assure Installation of the neces-
sary controls within the waiver period.
and to assure protection of the health
of persons during the waiver period.
(c) Prior to denying any request for
a waiver pursuant to this section, the
Administrator will notify the owner or
operator making such request of the Ad-
ministrator's Intention to issue such
denial, together with:
(1) Notice of the Information and
findings on which such intended denial
is based, and
(2) Notice of opportunity for such
owner or operator to present, within
such time limit as the Administrator
specifies, additional Information or argu-
ments to the Administrator prior to final
action on such request.
(d) A final determination to deny any
request for a waiver will be in writing
and will set forth the specific grounds on
which such denial is based. Such final
determination will be made within 80
days after presentation of additional in-
formation or arguments, or 60 days after
the final date specified for such presen-
tation. If no presentation Is made.
(e) The granting of a waiver under
tali section shall not abrogate the Ad-
ministrator's authority under section 114
of the act.
I 61.12 EmUdon totta and monitoring.
(a) Emission tests and monitoring
shall be conducted and reported as set
forth In this part and Appendix B to this
part.
(b) The owner or operator of a new
source subject to this part, and at the
or operator of an existing source sub-
ject to this part, shall provide or cause
to be provided, »mi««inn testing facili-
ties as follows:
(1) Sampling ports adequate for test
methods applicable to such source.
(2) Safe sampling platform (s).
(3) Safe access to sampling plat-
form (s) .
(4) Utilities for t«"r""g aad tasting
equipment.
(Bee. 114 of UM
(0 DJLC 7414H.
Atr Act u
| 61.13 Waiver of emiialoa tens.
(a) Emission tests may be waived
upon written application to the Admin-
istrator If, In his judgment, the source
is meeting the standard, or If the source
is operating under a waiver of compliance
or has requested a waiver of compliance.
(b) If application for waiver of the
emission test Is made, such application
shall accompany the Information re-
quired by I 81.10. The appropriate form
is contained in Appendix A to this part.
(c) Approval of any waiver granted
pursuant to this section shall not abro-
gate the Administrator's authority under
the act or In any way prohibit the Ad-
ministrator from later canceling such
waiver. Such cancellation will be made
only after notice Is given to the owner
or operator of the source.
(Sac 114 of UM Clean AH Act u
(43 O.H.C. 7414)1. W<
I 61.14 Source teat and analytical meth-
od*.
(a) Methods 101. 102, and 104 In Ap-
pendix B to this part shall be used for
all source tests required under this part
unless an equivalent method or an al-
ternative method has been approved by
the Administrator.
(b) Method 103 in Appendix B to this
part is hereby approved by the Admin-
istrator as an alternative method for
sources subject to I 81.32(a) and I 81.43
(b).
(c) The Administrator may, after no-
tice to the owner or operator, withdraw
approval of an alternative method
granted under paragraphs (a), (b) or
(d) of this section. Where the test results
using an alternative method do not ade-
quately indicate whether a source Is In
compliance with a standard, the Ad-
ministrator may require the use of the
reference method or its equivalent7
(d) Method 105 in Appendix B to this
part is hereby approved by the Adminis-
trator as an alternative method for
sources subject to I 81.B2tt» •
(•at 114 of the Qjyi Air Act as
<410.8.C. T414». **7
I 61.15 Availability of information.23
The availability to the public of in-
formation provided to, or otherwise ob-
tained by, the Administrator under this
part shall be governed by Part 2 of this
chapter.
>«*
I 61.17 Circnmrenlion.'
No owner or operator subject to the
provisions of this part shall build, erect,
Install, or use any article machine.
equipment, process, or method, the use of
which conceals an emission which would
otherwise constitute a violation of an
applicable standard. Such concealment
Includes, but Is not limited to, the use of
gaseous dilutants to achieve compliance
with a visible emissions standard, and
the piecemeal carrying out of an opera-
tion to avoid coverage by a standard that
applies only to operations larger than a
specified size.
A-5
-------
•I En
tarVbiylCMwM***
(a) Ibis subpart applies to plants
which produce:
(1) Ethylene dichlortde by reaction of
oxygen and hydrogen chloride with
ethylene,
<2> Vinyl chloride by any proceat,
•ad/or
(3) On* or more polymer* containing
my fraction of polymerised vinyl chlo-
ride.
(b) This subpart doee not apply to
equipment used in research and develop-
ment if the reactor used to polymerise
the vinyl chloride preceded in the equip-
ment ha* a capacity of no more than
0.19 m* (SO gal).
;
•1.67; 81.88; 61.68; 61.70; and 81.71 do
not apply to equipment used in research
and development if the reactor used to
polymerize the vinyl chloride processed
In the equipment has a capacity of
greater than 0.19 m* (SO gal) and no
more than 4.07 m • (1100 gal) .*
161.61 D*A»hiMu.
Terms used in this subpart are defined
m the Act. In Subpart A of this part, or
In this section as follows:
(a) "Ethylene dlehloride plant" In-
cludes any plant which produces ethyl-
ene dlehloride by reaction of oxygen and
hydrogen chloride with ethylene.
(b) "Vinyl chloride plant" Include*
any plant which produces vinyl chloride
by any process.
(c) "Folyvlnyl chloride plant" Include*
any plant where vinyl chloride alone or
In combination with other materials Is
polymerized.
(d) "Slip gauge" means a gauge which
has a probe that moves through the ga*/
liquid Interface In a storage or transfer
vessel and Indicate* the level of vinyl
chloride in the vessel by the physical
state of the material the gauge dis-
charges.
(ei "Type of resin" means the broad
classification of resin referring to the
basic manufacturing process for produc-
ing that resin. Including, but not limited
to. the suspension, dispersion, latex, bulk,
and solution processes.
"Dispersion resin" mean* a resin
manufactured in such away a* to font
fluid dispersions when dispersed in a
niaBticiTiftr or rlairtlf1*^iy/<^n"yTl^ nils-
tores.
(h) "Latex resin" means a resin which
Is produced by a polymeitaation peaces*
which Inlttates from free radical catalyst
sites and is aaWundrtad.
(1) "Bulk resin' •means a resin which
Is produced by a polymerization process
In which no water is used.
(]> "Inproeess wastewater" means any
water which, during manufacturing or
processing, comes into direct contact
with vinyl chloride or polyvinyl chloride
or result* from the production or use of
any raw material. Intermediate product,
finished product, by-product, or waste
product containing vinyl chloride or
polyvinyl chloride but which has not
been discharged to a wastewater treat-
ment process or discharged untreated as
wastewater.
(k) "Wastewater treatment process"
Includes any process which modifies
characteristics such as BOD, COD, TSS.
and pB, usually for the purpose of meet-
Ing effluent guideline* and standards; it
does not include any process the purpose
of which Is to remove vinyl chloride from
water to meet requirements of this
subpart.
(1) "In vinyl chloride service" means
that a piece of equipment contains or
contacts either a liquid that Is at least
10 percent by weight vinyl chloride or a
gas that is at least 10 percent by volume
vinyl chloride.
(m) "Standard operating procedure"
irnam a formal written procedure offi-
cially adopted by the plant owner or
operator and available on a routine basis
to those persona responsible for carrying
out the procedure.
(n) "Run" means the net period of
time during which an emission sample Is
collected.
(o> "Ethylene dlehloride purification"
Includes any part of the process of ethyl-
ene dlehloride production which follows
ethylene dichlortde formation and in
which finished ethylene dlehloride Is
produced.
(p) "Vinyl chloride purification" In-
cludes any part of the process of vinyl
chloride production which follows vinyl
chloride formation and In which finished
vinyl chloride Is produced.
(q) "Reactor" includes any vessel In
which vinyl chloride Is partially or totally
polymerized into polyvinyl chloride.
(r) "Reactor opening loss" means the
•missions of vinyl chloride occurring
when a reactor U vented to the atmos-
phere for any purpose other than an
emergency relief discharge as defined in
M1.65(a).
(s) "Stripper" Includes any vessel In
which residual vinyl chloride is removed
from polyvinyl chloride resin, except
bulk resin. In the slurry form by the use
of heat and/or vacuum. In the case of
bulk resin, stripper Includes any vessel
which Is used to remove residual vinyl
chloride from polyvinyl chloride resin
Immediately following the polymeriza-
tion step in the plant process flow.
(t) "Standard temperature" means a
temperature of 20* C (69* P).M
"Standard pressure" means a
pressure of 760 mm of Eg (39.92 in. of
Ht>.»
g 61.62 EmiMlon •UmUrd for ethylene
diehloride plant*.3*
(a) Ethylene dlehloride purification:
The concentration of vinyl chloride m
all exhaust gases discharged to the at-
mosphere from any equipment used In
ethylene dichlortde purification Is not
to exceed 10 ppm, except as provided In
|61.fiS(a). This requirement does not
apply to equipment that has been opened,
Is out of operation, and met the require-
ment In I 61.65 (b) (6) (1) before being
opened.
(b) Oxychlorinatlon reactor: Except
as provided in §61.65(a), emissions of
vinyl chloride to the atmosphere from
each oxychlorination reactor are not to
exceed 0.2 g/kg (0.0002 Ib/lb) of the 100
percent ethylene dlehloride product from
the oxychlorination process.
861.63 Emiwion itandird for vinyl
chloride pUnu.
An owner or operator of a vinyl chlo-
ride plant shall comply with the require-
ments of this section and j 61.65.
(a) Vinyl chloride formation and puri-
fication: The concentration of vinyl
chloride In all exhaust gases discharged
to the atmosphere from any equipment
used In vinyl chloride formation and/or
purification Is not to exceed 10 ppm, ex-
cept as provided In ] 61.65(a). This re-
quirement does not apply to equipment
that has been opened. Is out of operation,
and met the requirement In { 81.65 (b)
(•> (1) before being opened.
8 61.64 Emiuion ttAitdanl for polyvinjl
ehlorida pUnu.
An owner or operator of a polyvinyl
chloride plant shall comply with the re-
quirements of this section and I 61.65.
(a) Reactor. The following require-
ments apply to reactors:
(1) The concentration of vinyl chlo-
ride In all exhaust gases discharged to
the atmosphere from each reactor Is not
to exceed 10 ppm, except as provided In
paragraph (a) (2) of this section and
161.85 (a).
(2) The reactor opening loss from each
reactor Is not to exceed 0.02 g vinyl
chloride/kg (0.00002 Ib vinyl chloride/
Ib) of polyvinyl chloride product, with
the product determined on a dry solids
basis. This requirement applies to any
vessel which is used as a reactor or as
both a reactor and a stripper. In the
bulk process, the product means the
gross product of prepolymerizatlon and
postpolymerizatlon.
(3) Manual vent valve discharge: Ex-
cept for an emergency manual vent valve
discharge, there is to be no discharge to
the atmosphere from any manual vent
valve on a polyvinyl chloride reactor in
vinyl chloride service. An emergency
manual vent valve discharge means a
discharge to the atmosphere which could
not have been avoided by taking meas-
ures to prevent the discharge. Within 10
A-6
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dsvys of toy discharge to the atmosphere
from any manual vent valve, the owner
or operator of the uuree from which the
discharge occurs shall submit to the Ad-
ministrator a report In writing contain-
ing Information on the source, nature
and cause of the discharge, the date and
time of the discharge, the approximate
total vinyl chloride loss during the dis-
charge, the method used for determining
the vinyl chloride loss, the action that
was taken to prevent the discharge, and
measures adopted to prevent future dis-
charges.
(b) Srripper. The concentration of
vinyl chloride in all exhaust gases dis-
charged to the atmosphere from each
ttripper Is not to exceed 10 ppm. except
as provided In 181.65(a). This require-
ment does not apply to equipment that
has been opened. Is out of operation, and
met the requirement In | 61.65(b> (6) (1)
before being opened.
(c) Mixing, weighing, and holding
container}. The concentration of vinyl
chloride In all exhaust gases discharged
to the atmosphere from each mixing.
weighing, or holding container In vinyl
chloride service which precedes the
stripper (or the reactor If the plant has
no stripper) in the plant process flow Is
not to exceed 10 ppm. except as provided
in t 81.85(a). This requirement does not
apply to equipment that has been
opened, Is out of operation, and met the
requirement In { 61.65
-------
(tilling agitators with double mechani-
cal seals, or equivalent u provided in
181.88. If double mechanical seals are
used, vinyl chloride emissions from the
seals are to be minimized by maintaining
the pressure between the two seals so
that any leak that occurs Is Into the agi-
tated vessel; by ducting any vinyl chlo-
ride between the two seals through a
control system from which the concen-
tration of vinyl chloride in the exhaust
gases does not exceed 10 ppm; or equiva-
lent as provided in I 61.86.
(4) Leakage from relief valva. Vinyl
chloride emissions due to leakage from
each relief valve on equipment In vinyl
chloride service are to be minimized by
i n.t»inng a rupture disk between the
equipment and the relief valve, by con-
necting the relief valve discharge to a
process line or recovery system, or equiv-
alent as provided In ! 61.68.
(S) Manual venting of gases. Except
as provided In 8 61.64(a>(3>, all gases
which are manually vented from equip-
ment In vinyl chloride service are to be
ducted through a control system from
which the concentration of vinyl chloride
In the exhaust gases does not exceed 10
ppm; or equivalent as provided in I 61.86.
(6) Opening of equipment. Vinyl
chloride emissions from opening of
equipment (Including loading or unload-
ing lines that are not opened to the at-
mosphere after each loading or unload-
ing operation) are to be minimi*** as
follows:
(1) Before opening any equipment for
any reason, the quantity of vinyl chlo-
ride is to be reduced so that the equip-
ment contains no more than 2.0 percent
by volume vinyl chloride or 0.0950 m* (29
gal) of vinyl chloride, whichever Is
larger, at standard temperature and
pressure; and
(11) Any vinyl chloride removed from
the equipment In accordance with para-
graph (b) (6) (1) of this section Is to be
ducted through a control system from
which the concentration of vinyl chlo-
ride In the exhaust gases does not exceed
10 ppm, or equivalent as provided in
161.66.
(7) Samples. Unused portions of sam-
ples containing at least 10 percent by
weight vinyl chloride are to be returned
to the process, and sampling techniques
are to be such that sample containers In
vinyl chloride service are purged into a
closed process system.
(8) Leak detection and elimination.
Vinyl chloride emissions due to leaks
from equipment In vinyl chloride service
are to be minimized by instituting and
implementing a formal leak detection
and elimination program. The owner or
operator shall submit a description of
the program to the Administrator for
approval. The program is to be sub-
mitted within 45 days of the effective
date of these regulations, unless a waiver
of compliance is granted under I 61.11.
If a waiver of compliance la granted, the
program Is to be submitted on a date
scheduled by the Administrator. Ap-
proval of a program will be granted by
the Administrator provided he finds:
(1) It includes a reliable and accurate
Ttnyl chloride monitoring system for de-
tection of major leaks and Identification
of the general area of the plant where a
leak is located. A vinyl chloride monitor-
ing system means a device which obtains
air samples from one or more points on
a continuous sequential basis and ana-
lyzes the samples with gas chromatog-
raphy or. If the owner or operator as-
sumes that all hydrocarbons measured
are vinyl chloride, with infrared spectro-
photometry, flame Ion detection, or an
equivalent or alternative method.
(11) It Includes a reliable and accurate
portable hydrocarbon detector to be used
routinely to find small leaks and to pin-
point the major leaks Indicated by the
vinyl chloride monitoring system. A
portable hydrocarbon detector means a
device which measures hydrocarbons
with a sensitivity of at least 10 ppm
and Is of such design and size that It can
be used to measure emissions from local-
ized points.
(ill) It provides for an acceptable cali-
bration and maintenance schedule for
the vinyl chloride monitoring system and
portable hydrocarbon detector. For the
vinyl chloride monitoring system, a daily
span check Is to be conducted with a
concentration of vinyl chloride equal to
the concentration denned as a leak ac-
cording to paragraph (b) (8) (vl) of this
section. The calibration Is to be done
with either:
(A) A calibration gas mixture pre-
pared from the gases specified In sections
5.2.1 and 5.2.2 of Test Method 106 and
In accordance with section 7.1 of Test
Method 108, or'1
(B) A calibration gas cylinder stand-
ard containing the appropriate concen-
tration of vinyl chloride. The gas com-
position of the calibration gas cylinder
standard is to have been certified by the
manufacturer. The manufacturer must
have recommended a maximum shelf life
for each cylinder so that the concentra-
tion does not change greater than ±5
percent from the certified value. The date
of gas cylinder preparation, certified
vinyl chloride concentration and recom-
mended maximum shelf life must have
been affixed to the cylinder before ship-
ment from the manufacturer to the
buyer. If a gas chromatograph Is used as
the vinyl chloride monitoring system.
these gas mixtures may be directly used
to prepare a chromatograph calibration
curve as described in section 7.3 of Test
Method 106. The requirements in sec-
tion 6.2.3.1 and 5.2.3.2 of Test Method
108 for certification of cylinder stand-
ards and for establishment and verifica-
tion of calibration standards are to be
followed.3*
(iv) The location and number of points
to be monitored and the frequency of
monitoring orovided for in the program
are acceptable when they are compared
with the number of pieces of equipment
in vinyl chloride service and the size and
physical layout of the plant.
(v> It contains an acceptable plan of
action to be taken when a leak is de-
tected.
(vi) It contains a definition of leak
which is acceptable when compared with
the background concentrations of vinyl
chloride In the areas of the plant to be
monitored by the vinyl chloride monitor-
Ing system. Measurements of background
concentrations of vinyl chloride in the
areas of the plant to be monitored by the
vinyl chloride monitoring system are to
be Included with the description of the
program. The definition of leak for a
given plant may vary among the differ-
ent areas within the plant and Is also to
change over time as background con-
centrations in the plant are reduced.
(9> Inprocesa tocutcwater. Vinyl chlo-
ride emissions to the atmosphere from
Inprocess wastewater are to be reduced
as follows:
(1) The concentration of vinyl chlo-
ride In each Inprocess wastewater stream
containing greater than 10 ppm vinyl
chloride measured Immediately as it
leaves a piece of equipment and before
being mixed with any other Inprocess
wastewater stream is to be reduced to no
more than 10 ppm by weight before being
mixed with any other Inprocess wastewa-
ter stream which contains less than 10
ppm vinyl chloride: before being exposed
to the atmoshere; before being dis-
charged to a wastewater treatment proc-
ess: or before being discharged untreated
as a wastewater. This paragraph does
apply to water which Is used to displace
vinyl chloride from equipment before It
Is opened to the atmosphere In accord-
ance with i 61.64(a) (2) or paragraph
The requirements In paragraphs
(b)U). (b>(2), (b>(5). (b)(6),
and (b) (8) of this section are to be In-
corporated into a standard operating
procedure, and made available upon re-
quest for inspection by the Administra-
tor. The standard operating procedure Is
to Include provisions for measuring the
vinyl chloride in equipment ^4.75 m'
(1,250 gal) In volume for which an emis-
sion limit is prescribed In i 61.65(b) (6)
(1) prior to opening the equipment and
using Test Method 106, a portable hydro-
carbon detector, or an equivalent or al-
ternative method. The method of meas-
urement is to meet the requirements In
I 61.67(g) (5) (1) (A) or (g) ((5) (i) (B) .*
(Me. 114 of UM
OMB
Wf
Air Act as
A-8
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g 61.66 Equivalent equipment and pro-
cedures.
Upon written application from an own-
er or operator, the Administrator may
approve use of equipment or procedures
which have been demonstrated to his
satisfaction to be equivalent In terms of
reducing vinyl chloride emissions to the
atmosphere to those prescribed for com-
pliance with a specific paragraph of this
subpart. For an existing source, any re-
quest for using an equivalent method as
the Initial measure of control Is to be
submitted to the Administrator within
30 days of the effective date. For a new
source, any request for using an equiva-
lent method is to be submitted to the
Administrator with the application for
approval of construction or modification
required by I 61.07.
8 61.67 Emission test*.
(a) Unless a waiver of emission testing
b obtained under 161.13. the owner or
operator of a source to which this sub-
pan applies shall test emissions from
the source,
< 1) Within 90 days of the effective date
In the case of an existing source or a
new source which has an initial startup
date preceding the effective date, or
(2) Within 90 days of startup in the
case of a new source, initial startup of
which occurs after the effective date.
(b) The owner or operator shall pro-
vide the Administrator at least 30 days
prior notice of an emission test to afford
the Administrator the opportunity to
have an observer present during the test.
Any emission test Is to be con-
ducted while the equipment being tested
Is operating at the maximum production
rate at which the equipment will be op-
erated and under other relevant condi-
tions as may be specified by the Adminis-
trator based on representative perform-
ance of the source.
(d) [Reserved]3*
When at all possible, each sample
is to be analyzed within 24 hours, but In
no case in excess of 72 hours of sample
collection. Vinyl chloride emissions are
to be determined within 30 days after the
emission test The owner or operator
shall report the determinations to the
Administrator by a registered letter dis-
patched before the close of the next busi-
ness day following the determination.11
(f) The owner or operator shall retain
at the plant and make available, upon
request, for inspection by the Adminis-
trator, for a minimum of 2 years records
of emission test results and other data
needed to determine emissions.
(g) Unless otherwise specified, the
owner or operator shall use test Test
Methods In Appendix B to this part for
each test as required by paragraphs
(g)U>, (g)(2), (g)(3). (g)(4), and
(5) of this section, unless an equiva-
lent method or an alternative method
has been approved by the Administrator.
If the Administrator finds reasonable
ground* to dispute the results obtained
by an equivalent or alternative method.
he may require the use of a reference
method. If the results of the reference
and equivalent or alternative methods
do not agree, the results obtained by the
reference method prevail, and the Ad-
ministrator may notify the owner or
operator that approval of the method
previously considered to be equivalent or
alternative b withdrawn.
(1) Test Method 106 is to be used to
determine the vinyl chloride emissions
from any source for which an emission
limit Is prescribed in |(61.62(a) or (b)
| 61.63(a), or li 61.64(a) (1). (b), , or
(d), or from any control system to which
reactor emissions are required to be
ducted in 181.64 (a) (2) or to which fugi-
tive emissions are required to be ducted
Is I61.65(b)(l)(il>, (b)(2), (b)(5),
(b)(6)(U>,or (b)(9)(ll).
(1) For each run. one sample Is to be
collected. The sampling site Is to be at
least two stack or duct diameters down-
stream and one half diameter upstream
from any flow disturbance such as a
bend, expansion, contraction, or visible
flame. For a rectangular cross section an
equivalent diameter is to be determined
from the following equation:
tlon:
|C»(2.60)910-«| 1100|
equivalent diameter =
(length) (width)
' length + width
The sampling point in the duct b to
be at the centroid of the cross section.
The sample b to be extracted at a rate
proportional to the gas velocity at the
sampling point. The sample b to be
taken over a minimum of one hour, and
b to contain a minimum volume of 50
liters corrected to standard conditions.
(11) Each emission test b to consist of
three runs. For the purpose of determin-
ing emissions, the average of results of
all runs b to apply. The average b to be
computed on a time weighted basis.31
(ill) For gas streams containing more
than 10 percent oxygen the concentra-
tion of vinyl chloride as determined by
Test Method 106 b to be corrected to 10
percent oxygen (dry basis) for determi-
nation of emissions by using the follow-
ing equation:
._„. «>.«
20 a—percent O,
C»«r«rr~t«4i=The concentration of Tlnyl
chloride In the exhaust gaaea. correcMd
to 10-percent oxygen.
C>=The concentration of vinyl chloride as
measured by Teat Method 106.
30.9 = Percent oxygen tax the ambient air at
standard condition*.
10.9=Percent oxygen In the ambient air at
standard conditions, m<»^i« the 10.0-per-
cent oxygen to which the correction Is
being made.
Percent O3=Percent oxygen In the exhaust
gas aa measured by Reference Method 3
in Appendix A of Pan 60 of this chapter*
(iv) For those emission sources where
the emission limit Is prescribed in terms
of mass rather than concentration, mass
emissions In kg/100 kg product are to be
determined by using the following equa-
CVi=kg vinyl chloride/100 kg product.
C»=The concentration of vinyl chloride a*
measured by Test Method 106.
2.60=Density of vinyl chloride at one
atmosphere and 20* C In kg/m'.
Q=Volumetric flow rat* In m'/hr as de-
termined by Reference Method 2 of Ap-
pendix A to Part 60 of this chapter.
10"=Conversion factor for ppm.
Z=Productlon rate (kg/hr). *•
(2) Test Method 107 b to be used to
determine the concentration of vinyl
chloride in each Inprocess wastewater
stream for which an emission limit b
prescribed In I 61.6S(b) (9) d).
(3) Where a stripping operation b
used to attain the emission limit In {61.-
64(e), emissions are to be determined
using Test Method 107 as follows:
(1) The number of strippers and sam-
ples and the types and grades of resin to
be sampled are to be determined by the
Administrator for each Individual plant
at the time of the test based on the
plant's operation.
(11) Each sample b to be taken Imme-
diately following the stripping operation.
(Ill) The corresponding quantity of
material processed by each stripper b to
be determined on a dry solids basb and
by a method submitted to and approved
by the Administrator.
(Iv) At the prior request of the Ad-
ministrator, the owner or operator shall
provide duplicates of the samples re-
quired In paragraph (g)(3)(l) of thb
section.
(4) Where control technology other
than or In addition to a stripping opera-
tion b used to attain the emission limit
In I 61.64(e>, emissions are to be deter-
mined as follows:
(1) Test Method 106 b to be used to
determine atmospheric emissions from
all of the process equipment simultane-
ously. The requirements of paragraph
(g) (1) of thb section are to be met.
(11) Test Method 107 b to be used to
determine the concentration of vinyl
chloride In each inprocess wastewater
stream subject to the emission limit pre-
scribed In { 61.64(e). The mass of vinyl
chloride In kg/100 kg product in each
hi process wastewater stream b to be de-
termined by using the following equa-
tion:
[CtRlO-*] 11001
CM- z
where:
C«-kf vinyl chloride/100 if product.
C4«the concentration of vinyl chloride AS measured
by Ten Method 107.
/{•water Oow ntetn 1/hr. determined In accordance
with s method which has been submitted to
and approved by the Administrator.
l(r*-Convertlon (actor lor ppm.
Z^Prcductlon rate (kc/hr). determined In accord-
ance with a method which has been submitted
and approved by the Administrator.
(5) The reactor opening loss for which
an emission limit b prescribed in i 61.64
(a) (2) b to be determined. The numbei
of reactors for which the determination
A-a
-------
Is to be made li to be specified by the
Administrator for each Individual plant
at the time of the determination band
on the plant's operation. For a reactor
that la also used as a stripper, the deter-
mination may be made Immediately fol-
lowing the stripping operation.
(i) Except as provided in paragraph
(g)(5XU) of this section, the reactor
opening loss Is to be determined using
the following equation:
W (S.6O) (10-«) (Cb)
c=-
rz
where:
C- kg Tlnrl chloride emlaf ons/kf product.
IP-Capacity of the reactortn m1.
2JO- Density of Ttnyl chloride at one almof phere end
arcinkf/m'.
10"1- Conversion (actor for ppm.
Cft-ppm by Tolume vinyl chloride as determined by
Teat Method 10f or a portable hydrocarbon
detector which rneaanm hydrocarbona
with a aeoaltlrlty of at leaat 10 ppm.
J'-Number of bitches since the reactor wai Ian
opened to the atmosphere.
Z-Averaie k| of polyvlnyl chloride produced per
batch In the number of batchea alnce Ibe reactor
was Ian opened to the aunoaphere.
(A) If Method 106 Is used to deter-
mine the concentration of vinyl chloride
(Cb), the sample Is to be withdrawn at
a constant rate with a probe of sufficient
length to reach the vessel bottom from
the manhole. Samples are to be taken
for 5 minutes within 6 Inches of the ves-
sel bottom. S minutes near the vessel
center, and 5 minutes near the vessel top.
(B) If a portable hydrocarbon detec-
tor Is used to determine the concentra-
tion of vinyl chloride (Cb), a probe of
sufficient length to reach the vessel bot-
tom from the manhole Is to be used to
make the measurements. One measure-
ment will be made within 6 Inches of the
vessel bottom, one near the vessel center
and one near the vessel top. Measure-
ments are to be made at each location
until the reading is stabilized. All hydro-
carbons measured are to be assumed to
be vinyl chloride.
(C) The production rate of polyvlnyl
chloride (Z) is to be determined by a
method submitted to and approved by the
Administrator.
(11) A calculation based on the number
of evacuations, the vacuum Involved, and
the volume of gas in the reactor is hereby
approved by the Administrator as an al-
ternative method for determining reac-
tor opening loss for postpolymerlzatlon
reactors in the manufacture of bulk
resins.
g 61.68 Emieelon monitoring.
(a) A vinyl chloride monitoring sys-
tem is to be used to monitor on a con-
tinuous basis the emissions from the
sources for which emission limits are pre-
scribed In I 61.62, I 61.63(a),
and I 6l.64(a>U), (b), (c).and (d).and
for any control system to which reactor
emissions are required to be ducted in
I 61.64(a) (2) or to which fugitive emis-
sions are required to be ducted In i 81.65
(bHIHIl), and (b)(2>. (b)(5). (b) (fl)
(11),and (b) (9) (11).M
(b) The vinyl chloride monitoring sys-
tem (s) used to meet the requirement in
paragraph (a) of this section Is to be a
device which obtains air sampels from
one or more points on a continuous
sequential basis and analyzes the samples
with gas chromotography or, U the owner
or operator assumes that all hydrocar-
bons measured are vinyl chloride, with
infrared spectrophotometry. flame Ion
detection, or an equivalent or alterna-
tive method. The vinyl chloride monitor-
Ing system used to meet the requirements
in i 61.65(b) (8) (1) may be used to meet
the requirements of this section.
(c) A daily span check Is to be con-
ducted for each vinyl chloride monitor-
Ing system used. For all of the emission
sources listed In paragraph (a) of this
section, except the one for which an emis-
sion limit b prescribed in i 61.62(b), the
dally span check is to be concducted with
a concentration of vinyl chloride equal
to 10 ppm. For the emission source for
which an emission limit Is prescribed in
I 61.62(b), the daily span check Is to be
conducted with a concentration of vinyl
chloride which is determined to be
equivalent to the emission limit for that
source based on the emission test re-
quired by I 61.67. The calibration is to
be done with either:
(1) A calibration gas mixture pre-
pared from the gases specified in sections
5.2.1 and 5.2.2 of Test Method 106 and
in accordance with section T.I of Test
Method 106. or3*
(2) A calibration gas cylinder stand-
ard containing the appropriate concen-
tration of vinyl chloride. The gas com-
position of the calibration gas cylinder
standard Is to have been certified by the
manufacturer. The manufacturer must
have recommended a maximum shell
life for each cylinder so that the concen-
tration does not change greater than
:±5 percent from the certified value. The
date of gas cylinder preparation, certified
vinyl chloride concentration and recom-
mended maximum shelf life must have
been affixed to the cylinder before ship-
ment from the manufacturer to the
buyer. If a gas chromatograph is used as
the vinyl chloride monitoring system,
these gas mixtures may be directly used
to prepare a chromatograph calibration
curve as described in section 7.3 of Test
Method 106. The requirements in sec-
tions 5.2.3.1 and 5.2.3.2 of Test Method
106 for certification of cylinder stand-
ards and for establishment and verifica-
tion of calibration standards are to be
followed.'1
(Bee, 114 of th» Cl«an Air Act «
<«U.B.C. 7414)>.«W<
(b><6). (b>(7). and (b>(8) are being
Implemented.
(b) (1) In the case of an existing
source or a new source which has an
Initial startup date preceding the effec-
tive date, the statement is to be submit-
ted within 90 days of the effective date.
nni»« a waiver of compliance Is granted
under ! 61.11. along with the informa-
tion required under t 61.10. If a waiver
of compliance Is granted, the statement
Is to be submitted on a date scheduled
by the Administrator.
(2) In the case of a new source which
did not have an Initial startup date pre-
ceding the effective date, the statement
is to be submitted within 90 days of the
initial startup date.
(c) The statement Is to contain the
following Information:
(1) A list of the equipment Installed
for compliance,
(2) A description of the physical and
functional characteristics of each piece
of equipment.
(3) A description of the methods
which have been Incorporated Into the
standard operating procedures for meas-
uring or calculating the emissions for
which emission limits are prescribed In
i 61.65 (b) U) (1) and .
§ 61.70 Semiannual report.
(a) The owner or operator of any
source to which this subpart applies shall
submit to the Administrator on Septem-
ber 15 and March 15 of each year a report
in writing containing the Information
required by this section. The first semi-
annual report is to be submitted follow-
ing the first full 6 month reporting period
after the initial report Is submitted.10
(b) (1) In the case of an existing source
or a new source which has an initial
startup date preceding the effective date,
the first report Is to be submitted within
180 days of the effective date, unless a
waiver of compliance is granted under
i 61.11. If a waiver of compliance Is
granted, the first report is to be sub-
mitted on a date scheduled by the Ad-
ministrator.
(2) In the case of a new source which
did not have an Initial startup date pre-
ceding the effective date, the first report
Is to be submitted within 180 days of the
Initial startup date.
(c) Unless otherwise specified, the
owner or operator shall use the Test
Methods in Appendix B to this part to
conduct emission tests as required by
paragraphs (c)(2) and COO) of this
section, unless an equivalent or an alter-
native method has been approved by the
Administrator. If the Administrator
finds reasonable grounds to dispute the
results obtained by an equivalent or al-
ternative method, he may require the use
A-10
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ol a reference method. If the results of
the reference and equivalent or alterna-
tive methods do not agree, the results
obtained by the reference method pre-
vail, and the Administrator may notify
the owner or operator that approval of
the method previously considered to be
equivalent or alternative Is withdrawn.
(1) The owner or operator shall In-
clude In the report a record of any emis-
sions which averaged over any hour
period (commencing on the hour) are
In excess of the emission limits pre-
scribed in SS61.62(a) or (b), J61.83,
or ! 61.64(a)il). ib), , or (d), or for
any control system to which reactor
emissions are required to be ducted In
I 61.84(a) (2) or to which fugitive emis-
sions are required to be ducted In I 61.8S
(bHlMll). (b)(2), (b><5), (b)(6)(U).or
(b) (9) (11). The emissions are to be meas-
ured In accordance with § 61.68.
(2) In polyvlnyl chloride plants for
which a stripping operation is used to
attain the emission level prescribed In
I61.64(e>. the owner or operator shall
Include In the report a record of the
vinyl chloride content In the polyvinyl
chloride resin. Test Method 107 is to be
used to determine vinyl chloride content
as follows:
(1) If batch stripping Is used, one rep-
resentative sample of polyvlnyl chloride
resin Is to be taken from each batch of
each grade of resin Immediately follow-
ing the completion of the stripping op-
eration, and identified by resin type and
grade and the date and time the batch
Is completed. The corresponding quan-
tity of material processed In each strip-
per batch Is to be recorded and Identi-
fied by resin type and grade and the.,
date and time the batch Is completed?*
(11) If continuous stripping Is used,
one representative sample of polyvlnyl
chloride resin Is to be taken for each
grade of resin processed or at Intervals
of 8 hours for each grade of resin which
la being processed, whichever is more fre-
quent. The sample Is to be taken as the
resin flows out of the stripper and Iden-
tified by resin type and grade and the
date and time the sample was taken.
The corresponding quantity of material
processed by each stripper over the time
period represented by the sample during
the eight hour period, is to be recorded
and Identified by resin type and grade
and the date and time It represents.
(Ill) The quantity of material proc-
essed by the stripper Is to be determined
on a dry solids basis and by a method
submitted to and approved by the Ad-
ministrator.
(Iv) At the prior request of the Ad-
ministrator, the owner or operator shall
provide duplicates of the samples re-
quired In paragraphs
-------
APPBOIX A
Rational Drlulon Standard! for Haardous Air Pollutant*
Coapltanct Sutui Information
KPOKT
mmucnOKSi Owwrtof epmtort eftwett of
kazardon pollutanti wbjoet to On National
Union Standards for Huirdout Air Pollutanti
tn raqirlrtd to iub»1t tin Infenatlon conttlnad
IB Sactlon I to tht approprlata U.S. Envlromntal
Protection Aoancy Raglona! Offlc* prior to 90 day*
•fur th« affaetlvo date of tny lUndard* or otnd>
•ntt «Meh roqulrt tin wMulOR of luch
Information.
A lilt of r*9lom1 offlett 1l pmlihd In IS1.04.
A. SPUME
1. Idtnt1f1e»t1on/l.»at1oii - tndleit* tin HIM ind iddrtit of «tek uurci.
1 t 14 » t t n 8 0 B 88 t
BgToa nn* Cowty Jburet Hiabtr 14 !• 17 II IT
IB g tS _ M ^ _ _ _ _
AQW r Cny tofli v souret nS T«
47 SCTNt MOItU (LOCttlOn Of F1UKJ W 85
_
213 - CttyXtoi S4 SH& Si »
40 Sttta Regti
eVSIC—B TF wP staff W
64 65
If VS SI> 1C SB*
30 II 41
> Indicate tht nan and telephone nuebar of tht owiar or operator
ntppnslbl*. official vhc* EPA ny contact concerning this report.
Ana coot 47 aoetr M V
3. Source Description - IHtfly state tht Mter* of the source (a.|., "Oilor-
alkali Plant' or TtacJllut Slwp').
4.
«.
1J 20 21
n continued
Alternetln Nalllno Addrtss - Ind1
to a location different than that
Oup 1-18 » 3
Duo 1-18 t 4
CngManee Status - The Hriuloni
flttcrlptlta H
79 M
cite en elternatlvt
1i to be directed
specified above.
if street or Ion KuBer 49 to
yi x
City IS state 41 Zip 44
fn» this sourct can cannot Beet
prior to 90 dajn afttr tht tfftctlvt datt of any itandardi or
•blcfe mfjlrt tht tu6«1ii1on of inch Intonation.
tqniturt or oxntr. Ootrator or otntr
r atspcnsibit Official
t By tnt PUtional
p"t- IT we emssions fro« the source will caceed those it*1ts set _, —
CTssloii Standar«i for Kaiardeus «1r relluuau, tke source Kill be In violation and
***4oct to Federal tnforcwut action* «\ni frented a «e1»er •< coecillance by the
Mrlnlitntor of tht U.S. Em.1rw.nu1 Protection Aftnc*. Tkt Information Mtded for
•ck «1«en It Hittd In Station 11 of tMs form.
A-12
-------
*. HOCtSS lyomtTMi. ».rt I itoultf b* o»»ltu« itwnulr for MC* ptnt of
•lition Tor lien Kiurdous pollnUnt. ESourcu lubjtct to fl.ZZ(l) •>» «•'!
4* talon*}
il-U
e o s
TTT* If
a »
Mr ts SIP
tl.
Miuunt
process.
32 33
Pollutint
Wtted .
Indlot*
34
Indlcat* thi typ*
•«• for asbestos,
Mfuittion
of hutnlous pollutant oritted by the
*ST for berylllui. or 'HS' for Mrcury.
46 49
EC
I. Proetss Oeterlptlon - Prav1d« t brUf dtscrlptlon of tieh proetis («.g.,
-lurdrogcn end oox' m i nercury ehlor-tlktll plant. 'Brlndlns MChlm' IB
a berylH» nachlne shop). Ust iddltlontl shetti If necessary.
Process Description
Bff
01
Oup 1-18
is a>
zr
"75
X Aneunt of Pollutint - Indicate the eveVage Might of the hazardous naterlal
nand in itm i which enters the process 1n pounds per conth (based on the
previous twelve tenths of operation).
29
lbj./BO.
is
V
Control Devices
T,indicate the type of pollution control devices, If any, used to reduce
the eorisslons froti the process (e.g., venturl scrubber, baghousa, wet
cyclone) and the estimated percent of the-pollutant which the device
ranoves froai the process gas stream.
Dup 1-18 6 4
19 2b 21
»s rrinary Device Nane
V
PRIMARY CONTROL DEVICE:
6E 70
64 Percent Ranovai 72
IS
19
DIB 1-n ( ,S
|_ T» 10 «1
SCOMVKIT C8KTWX BEVfCES:
' '" 45
47 Secondary Dtvlct HUH
I M 66 70
1 EFF1C.
72 7s Bfl
Efficiency
A-13
-------
ii.
A. MAIVER Of CCMPIIAHCE. Owners or operators of sources uniblt to operate In
compliance with the National Emission Standards for Hazardous Air Pollutants
prior to 90 days aftir the effective ditt of my standards or amendments which
require the submission of such Information may request a waiver of compliance
from tht Administrator of tht U.S. Environmental Protection Agtncy for tht
tint period ntctssiry to Instill appropriate control devices or make
modifications to achieve compliance. Tht Administrator nay grint I waiver
kf compliance with tht standard for a ptrlod not exceeding two years from
the effective date of the hazardous pollutant standards. If ht finds that
Inch period 1s necessary for the Instillation of controls and that steps
will be taken during the period of the waiver to assure that the health
•f persons will be protected from Imminent endangerment.
The report Information provided 1n Stctlo' I must ecco-wtny t*-is application.
Applications should be sent to the appropriate EPA regional office.
1. Processes Involved - Indicate tht process or process*? nlnlnr hizirdtus
polluunts to which i»1::1oi contrn'i are to bi ipp'--,J.
2. Controls
i. Describe the proposed type of control device to bt idded or
•edification to bt ndt to tht process to reduce tht emissions
of hazardous pollutants to in acceptable level. (Ust additional
sheets If necessiry.)
b. Describe tht measures thit 'will bt taken during tht waiver period
to issurt thit the heilth of persons will bt protected from
Imminent tndirigtmnt. (Uit tddltlonil shuts If nicessary.)
1. Increments of Progress - Specify tht dates By which tht following
Increments of progress (rill bt Ht.
• Date by which contracts for emission control syittis or process
codifications will bt awarded; or date by which orders will bt
Issued for tht purchase of tht component parts to accompllja
emission control or process aodlflcitlon.
Dup 1-16 0 1 7 .
17 T» S3"~5» 55 «J «1 */6V/Vft Gs 8T
• Date of Initiation of on-i1te connnictlon or Installation of
ealsslon control equipment or process clunje.
Oup 1-16 027
17 ft 51"~5» 55 fo 61 M/BV/rR 56 !?
• Oite by which on-s1tt construction or Instillation of emission control
equipment or process e»d1Hcat1=n 1s to be completed.
53 54 55 60 61 MO/cr/Yk 56 IT
Date by which final compliance 1s to bt achieved.
S3 54 55 60 61 ID/OY/TR 56 SB"
»V>IVER CF EMISSION TESTS. A nlvtr of emission ttstlnj nay be granted to
owners or operators of sources of beryl!inn or mercury pollutants If. 1n
the judgotnt of the Administrator of the Environmental Protection Agency
the emissions from the source comply wlin the appropriate standard or 1f
the owners or operators of the source hive requested a waiver of compliance
or have bttn granted a waiver of con>llance.
This application should iccoopiny the-report Information provided 1n
lection I.
1. Reason - State tht reasons for requesting a waiver of emission testing.
If the reason stated Is thit tht missions from tht source are within
tht prescribed limits, documtntitlon of this condition rust be attached.
Signature of the owner or operator
(Sec. 114 of tht Clemn Air Act u tnwcided
(43 U.B.C. 7414». «0,4T
A-14
-------
14XTHOD KM—DVTOlcrjf4TXOlf OF
CXLO&ZDX TBOM STATIONAaT SOTrBCXa
1M1 RUBUC'HOIf
Performance of this method should not be
attempted by persona iiTif.miii«f with the
operation of a gas chromatograph. nor by
those who an unfamiliar with source sam-
pling. as then are miny details that an
beyond the acope of thli presentation. Can
muit be exercised to prevent exposure of
sampling personnel to Tlnyl chloride, a car-
cinogen.
1. Principle and Applicability.
1.1 An Integrated bag sample of Rack
gas containing vinyl chloride (ehloroethene)
u subjected to chromatographlc analysis. lift-
Ing a flame lontzatlon detector. M
1.2 The method Is aopllcable to the meas-
urement of vinyl chloride In stack gases from
ethylene dlchlorlde. Tlnyl chloride and poly-
Tlnyl chloride manufacturing processes, ex-
oept when the Tlnyl chloride Is contained In
pmrtlculate matter.
3. Range and Sensitivity.
The lover limit of detection will vary ac-
cording to the chromatograph used. Values
reported Include 1 X 10-' mg and 4 X 10-'
m».
1. Interferences. Acetaldehyde. which can
occur In some Tlnyl chloride sources, will In-
terfere with the Tlnyl chloride peak from
tne Chromaeorb 103 * column. See section
4-JJ and 6.4. If resolution of the Tlnyl
chloride peak Is still not satisfactory for a
particular sample, then cbramatograph pa-
rameters can be further altered with prior
approTal of tbe Administrator. If alteration
of the chromatograph parameters falls to
resolTe the Tlnyl chloride peak, then sup-
plemental confirmation of the Tlnyl chloride
peak through an absolute analytical tech-
nique, such a* mass spectroscopy, must be
performed.w
4. Apparatus.
4.1 Sampling (Figure 109-1).
4.1.1 Probe—Stainless steel. Pyrei glass.
or Teflon tubing according to itack temper-
ature, each equipped with a glass wool plug
to remove partlculate matter.
4.1.2 Sample line—Teflon. 8.4 mm outside
diameter, of sutflclent length to connect
probe to bag. A new unused piece Is employed
for each series of bag samples that constitutes
an emission test.
4.1.3 Male (2) and female (2) stalnlees
stael quick-connects, with ball checks (one
pair without) located as shown In Figure
108-1.J8
4.1.4 Tedlar bags. 100 liter capacity—To
contain sample. Teflon bags are not accept-
able. Aliunlnlzed Mylar bags may be used.
provided that tbe samples are analyzed
within 24 hours of collection.
4.1.5 Rigid leakproof containers for 4.1.4,
with covering to protect contents from sun-
light.
4.1.8 Needle valve—To adjust sample flow
rate.
4.1.7 Pump—teak-free. Minimum capac-
ity 2 liters per minute.
4.1.8 Charcoal tube—To prerent admis-
sion of Tlnyl chloride to atmosphere In vicin-
ity of samplers.
4.1.9 Flow meter—For observing sample
now rate: capable of measuring a flow range
from 0.10 to 1.00 liter per minute.
4.1.10 Connecting tutting. Teflon. 8.4
mm outside diameter, to assemble sample
train (Figun 106-1).M
< Mention of trade names on specific prod-
uct* does not constitute endorsement by Ibe
EnTlronmsnteJ Protection Agency.
4.1.11 PItot tube—Type S (or equlTalent).
attached to the probe so that the sampling
flow rate can be regulated proportional to
the stack gas Telocity.
4.2 Sample recovery.
4.2.1 Tubing—Teflon, 8.4 mm outside
diameter, to connect bag to gas chromato-
graph sample loop. A new unused piece is
employed for each series of bag samples that
constitutes an emission test, and Is to be dis-
carded upon conclusion of analysis of those
bags.
4.3 Analysis.
4.3.1 Oas chromatograph—With flame
lonlzatlon detector, potentlometrle strip
chart recorder and 1.0 to 5.0 ml heated sam-
pling loop in automatic sample Talve.
4.3.2 C/iromaropraphfc column, stainless
steel. 2 mx3J mm, containing 80/100 meet
Chromasorb 102. A secondary column of OB
SF-98, 20 percent on 80/80 mesh AW Chroma-
sorb p. stainless steel, 2 m x 3.2 mm or Pora-
pak T. 80/100 mesh, stainless steel. 1 mxSJ
mm Is required If scetaldehyde Is present. If
used, a secondary column Is placed after the
Chromasorb 102 column. The combined^
columns should then be operated at 120* C?
4.3.3 Flow meters (2)—Rotameter type,
0 to 100 ml/mln capacity, with flow control
TalTes.
4.3.4 Oas regulators—For required gas
cylinders.
4.3.5 Thermometer—Accurate to one de-
gree centigrade, to measure temperature of
heated sample loop at time of sample Injec-
tion.
4.3.8 Barometer—Accurate to 5 mm Rg. to
measure atmospheric pressure around gas
ehromatograph during sample analysis
4.3.7 Pump—Leak-free. Minimum capac-
ity 100 ml/mln.
4.4 Calibration.
4.4.1 Tubing—Teflon, 6.4 mm outside
diameter, separate pieces marked for each
calibration concentration.
4.4.2 Tedlar bags—Slxteen-lnch square
size, separate bag marked for each calibra-
tion concentration.
4.4.3 Syringe—0.5 ml. gas tight.
4.4.4 Syringe—SOul. gas tight.
4.4.5 Flow meter—Rotameter type. 0 to
1000 ml/mln range accurate to =1%. to
meter nitrogen In preparation of standard
gas mixtures.
4.4.8 Stop watch—Of known accuracy, to
time gas flow In preparation of standard gas
mixtures.
5. Reagents. It Is necessary that all rea-
gents be of chromatographlc grade.
6.1 Analysis.
6.1.1 Helium gas or nitrogen gas—Zero
grade, for chromatographlc carrier gas.
6.1.2 Hydrogen gas—Zero grade.
6.1.3 Oxygen gas. or Air, as required by
the detector—Zero grade.
S3 Calibration. Use one of the following
options: either 5.2.1 and 5.2.2. or 6.2.3.J«
6.2.1 Vinyl ehlorUt, »9.9-i- percent. Pure
Tlnyl chloride gas certified by the manufac-
turer to contain a minimum of M.9 percent
Tlnyl chloride for use In the preparation of
standard gas mixtures In Section 7.1. If the
gas manufacturer malntitns a bulk cylinder
supply of 99.9-"- percent Tlnyl chloride, the
certification analysis may haTe been per-
formed on this supply rather than on each
gas cylinder prepired from this bulk supply.
The date of gas cylinder preparation and the
certified analysis must have been affixed to
the cylinder before shipment from the gas
manufacturer to tbe buyer.**
5.3.2 Nitrogen gat. Zero grade, for prepa-
ration of standard gas mixtures.'1
SJJ Cylinder standard* (I). O«e mix-
ture standard* (60, 10. and 6 ppm Tlnyl
chloride In nitrogen cylinders) for which the
gas composition lisa been certified by the
manufacturer. The manufacturer must have
recommended a maximum shelf life tor each
cylinder so that the concentration does not
change greater than =5 percent from the
certified value. The date of gas cylinder prep-
aration, certified vinyl chloride concentra-
tion and recommended maximum shelf life
must have been affixed to the cylinder before
shipment from the gas manufacturer to the
buyer. These gas mixture standards may be
directly used to prepare a chromatograph.
calibration curve as described In section 7 3M
5.2.3.1 Cylinder standards certification
The concentration of vinyl chloride In nitro-
gen In each cylinder must have been certified
by the manufacturer by a direct analysis of
each cylinder using an analytical procedure
that the manufacturer had calibrated on the
day of cylinder analysis. The calibration of
the analytical procedure shall, as a minimum,
have utilized a three-point calibration curve.
It Is recommended that the manufacturer
maintain two calibration standards and use
these standards In the following way: (1) A
high concentration standard (between 50 and
100 ppm) for preparation of a calibration
curve by an appropriate dilution technique:
(2) a low concentration standard (between
6 and 10 ppm) for verification of the dilution
technique used. 3&
5.2.3.2 Establishment and aerification of
calibration standards. The concentration of
each calibration standard must have been
established by the manufacturer using
reliable procedures. Additionally, each
calibration standard must have been veri-
fied by tbe manufacturer by one of the
following procedures, and the agreement
between the Initially determined concen-
tration value and the verification concen-
tration value must be within — 5 percent:
(1) verification value determined by com-
parison with a calibrated vinyl chloride
permeation tube. (2) verification value
determined by comparison with a gas mix-
ture prepared In accordance with the pro-
cedure described In section 7.1 and using
99.9-1- percent vlnyle chloride, or (3t verifi-
cation value obtained by having the
calibration standard analyzed by the Na-
tional Bureau of Standards. All calibration
standards must be renewed on a time
Interval consistent with the shelf life of
the cylinder standards sold. 3°
6. Procedure.
6.1 Sampling. Assemble the sample train
as In Figure 106-1. Perform a bag leak check
according to Section 7.4. Observe that all
connections between the bag and the probe
are tight. Place tbe end of the probe at the
centrold of the stack and start the pump
with the needle valve adjusted to yield a
flow of 0.5 Ipm. After a period of time suffi-
cient to purge the line several times has
elapsed, connect the vacuum line to the
bag and evacuate tbe bag until the rotam-
eter Indicates no flow. Then reposition the
sample and vacuum lines and begin the ac-
tual sampling, keeping the rate proportional
to the stack velocity. Direct the gas exiting
the rotameter away from sampling personnel.
At the end of the sample period, shut off ths
pump, disconnect the sample line from the
bag, and disconnect tbe vacuum line from
the bag container. Protect the bag container
from sunlight.
BJ Sample itoraye. Sample bags must be
kept out of direct sunlight. When at all
possible analysis Is to be performed within
34 hours, but in no case in excess of 72
noun of samole collection.3*
9J Sample recovery with a piece of Tef-
lon tubing Identified for that bag. connect a
A-15
-------
bag Inlet valve to the gu chromatograph
•ample valve. Switch the valve to withdraw
f*M tram tha bag through til* aample loop.
Plumb the equipment ao tha (ample gu
paaaea from the aample valve to the leak-free
pump, and then to a charcoal tube, followed
by a 0-100 ml/mln rotameter with flow con-
trol valve.
8.4 Analysis. Bet the column temperature
to 100* C, the detector temperature to 160*
C. and the aample loop temperature to TO* C.
When optimum hydrogen and oxygen flow
ratee have been determined vertly and main-
tain these flow rates during all chromato-
graph operations. Using zero helium or
nitrogen as the carrier gas. establish a flow
rate In the range consistent with the manu-
facturer's requirements for satisfactory de-
tector operation. A flow rate of approxi-
mately 40 ml/mln should produce adequate
separation*. Observe the base line periodi-
cally and determine that the nolae level haa
stabilized and that base line drift has ceased.
Purge the sample loop for thirty seconds at
the rate of 100 mi/mm, then activate the
aample valve. Record the Injection time (the
position of the pen on the chart at the time
of sample Injection), the sample number, the
sample loop temperature, the column tem-
perature, carrier gu flow rate, chart speed
and the attenuator setting. Record the lab-
oratory pressure. From the chart, select the
peak having the retention time correspond-
ing to vinyl chloride, u determined In Sec-
tion 7.2. Measure the peak area. A., by use
of a disc integrator of a planlmeter. Measure
the peak height, H». Record A>. H.. -and
the retention time. Repeat the Injection at
leut two times or until two consecutive vinyl
chloride peaks do not vary In area more than
»%. The average value for these two areu
will be used to compute the bag concentra-
tion. M
Compare the ratio of H. to A. for the vinyl
chloride sample with the same ratio for the
standard peak which Is closest In height. As
a guideline. If these ratios differ by more
tban 10%. the vinyl chloride peak may not
be pure (possibly acetaldehyde Is present)
and the secondary column should be em-
ployed (see Section 4.3.2).
8.6 Measure the ambient temperature and
barometric pressure near the bag. (Assume
the relative humidity to be 100 percent.)
From a water saturation vapor pressure table.
determine and record the water vapor con-
tent of the bag.30
7. Calibration and Standards.
7.1 Preparation of vinyl chloride stand-
ard gat mixtures. Evacuate a slxteen-lnch
square Tedlar bag that has passed a leak
check (described In Section 7.4) and meter
In 5 liters of nitrogen. While the bag Is
filling, use the 0.6 ml syringe to inject
260ol of 99.9+ percent vlnvl chloride
through the wall of the bag. Upon with-
drawing the syringe needle. Immediately
cover the resulting hole with a piece of
adhesive tape. Tbe bag now contains a
vinyl chloride concentration of 60 ppm. In
a like manner use the other syringe to
prepare gu mixtures having 10 and 6 ppm
vinyl chloride concentrations. Place each
bag on a smooth surface and alternately
depress opposite sides of the big 60 times
to further mix the gases. These gas mixture
standards may be used for 10 days from the
date of preparation, after which time prep-
aration of new gas mixture* I* required.
(CAOTIOH.—Contamination may be a prob-
lem when a bag Is reused If the new gu
mixture standard contains a lower con-
centration than the previous gu mixture
standard did.)iH
7.2 Determination of vinyl chloride re-
tention time. Title section can be oerformed
simultaneously with Section 7.3. Establish
chromatograph conditions Identical with
Have 1M-1. Uuint* Ms i—Hlii nil*.
those In Section 8.3, above. Set attenuator
to X 1 position. Flush the sampling loop
with zero helium or nitrogen and activate
the sample valve. Record the Injection time,
the sample loop temperature, the column
temperature, the carrier gu Cow rate, the
chart speed and the attenuator setting.
Record peaks and detector responses that
occur In the absence or vinyl chloride. Main-
tain conditions. With the equipment plumb-
Ing arranged Identically to Section 6.3. flush
the sample loop for 30 seconds at the rate of
100 ml/mln with one of the vinyl chloride
calibration mixtures and activate the sample
valve. Record the Injection time. Select the
peak that corresponds to vinyl chloride.
Meuure the distance on the chart from the
Injection time to the time at which the peak
maximum occurs. This quantity, divided by
the chart speed. Is denued ss the retention
time record.
7.3 Preparation o/ chromatoaraph cali-
bration curve. Make a gas chromatographlc
measurement of each gu mixture standard
(described In section 6.2.2 or 7.1) using con-
ditions Identical with those listed In sections
8.3 and 8.4. Flush the sampling loop (or 30
seconds at the rate of 100 ml/mln with each
standard gu mixture and activate the sam-
ple valve. Record C,. the concentration of
vinyl chloride Injected, the attenuator set-
ting, chart speed, peak area, sample loop
temperature, column temperature, carrier
gu flow rate, and retention time. Record the
laboratory pressure. Calculate At, the peak
area multiplied by the attenuator setting.
Repeat until two Injection areu are within
8 percent, then plot these points v. C,. When
the other concentrations have been plotted,
draw a smooth curve through the points.
Perform calibration dally, or before and after
each set of bag samples, whichever Is mom
frequent.38
7.4 Bag leak checks. While performance
of this section Is required subsequent to bag
use. It la also advised that It be performed
prior to bag use. After each use, make sure
a bag did not develop leak* u follow*. To leak
check, connect a water manometer and pres-
surlze the bag to 6-10 cm H,O (2-4 In H,O).
Allow to stand for 10 minute*. Any displace-
ment In the water manometer Indicate* a
leak. Also cheek the rigid container for leak*
In *>»!• manner.
(Note: An alternative leak cheek method
I* to pressurize the bag to 6-10 cm B,O or
2-4 In. R,O and allow to stand overnight.
A deflated bag Indicates a leak.) For each
sample bag la It* rigid container, place a
rotameter In-line between the bag and the
pump Inlet. Evacuate {be bag. Failure of the
rotameter to register zero flow when the bag
appears to be empty Indicates a leak.
8. Calculations.
8.1 Determine the sample peak area u
follows :
Equation 108-1
wbcre.
A ,*• The sample peak ana.
XB«The measured peak area.
Af— Tb« attenuation factor.
8.2 Vinyl chloride concentrations. Prom
the calibration curve described In Section
7.3. above, select the value of C, that cor-
responds to A,, the sample peak area. Cal-
culate Ck u follows :
C,=
C.P.T,
P.T, (1-Sr.)
Where:
Equation 109-2
S.»-Tb« wsltr 'spar content of the bat lamble. at
attaly ed.
Ci"The concentration of vinyl chloride In toe bat
sample In ppm.
C.-The concentration of vinyl chloride Indicated by
the gas cnromauitrsph. in ppm.
P,-The referrnc* pressure, the laboratory pressure
recorded during calibration, nun Hg.
7\«The sample Icop temperature on the absolute
scale at the tune of analysts. "K.
Pt-The laboratory pressure at time of analysis, ""«
Hg,
T,-The reference temperature, the sample loop
temperature recorded during caubnuon', *aV
9. References.
1. Brown, D. W.. Loy, E. W. and Stephen-
eon. M. H. "Vinyl Chloride Monitoring Near
the B. P. Qcodrlcb Chemical Company In
Louisville, Kentucky." Region IV. U.S. Envi-
ronmental Protection Agency, Surveillance
and Analysis Division, Athens, Georgia. June
24. 1974.
2. "Evaluation of A Collection and Analy-
tical Procedure for Vinyl Chloride In Air."
by O. D. Clayton and Associates, December
13, 1974. EPA Contract No. 88-02-1408, Tuk
Order No. 2, EPA Report ON. 76-VCIr-l.
8. "Standardization of Stationary Source
Emission Method for Vinyl Chloride," by Mid-
west Research Institute, 1978. EPA Contract
No. 88-02-1088. Task Order No. 7.
(Sec. 114 of the Clean Air Act u amended
(43 DAC. 7414)). *M7
A-16
-------
METHOD 107—DVTKMCINATION or VIHTL CHLO-
OZDX CONTXNT OF INPKOCZSB WAaTTWATEa
SAMPLES. AND Vnm. CKLOUDE CONTENT or
POLTVZKTI. CHLOEXDE Rcsm, SZ.UEEY. WET
f!*if» AND LATZX SAMPLES
ZNTBODUCTXON
Performance of this method should not b«
attempted by persons unfamiliar with the
operation of a gas chromatograph, nor by
thoae who are unfamiliar with sampling, as
there are many details that are beyond the
•cope of this presentation. Care must be
exercised to prevent exposure of sampling
personnel to vtnyl chloride, a carcinogen.
1. Principle and Applicability
1.1 The basis [or this method relates to
the vapor equilibrium which Is established
between RVCM. PVC, resin, water, and air
In a closed system. It has been demonstrated
that the RVCM In a PVC resin will equili-
brate In a closed vessel quite rapidly, pro-
vided that the temperature of the PVC resin
la maintained above the glass transition
temperature of that specific resin.
1.2 This procedure Is suitable for deter-
mining the vinyl chorlde monomer (VCM)
content of Inprocess wastewater samples, and
the residual vinyl chloride monomer
(RVCM) content of polyvlnyl chloride
(PVC) resins, wet cake, slurry, and latex
samples. It cannot be used for polymer In
fused forms, such as sheet or cubes. If a
resolution of the vinyl chloride peak Is not
satisfactory for a particular sample, then
chromatograph parameters may be altered
provided that the precision and reproducl-
blllty of the analysis of vinyl chloride cylin-
der standards are not Impaired. If there Is
reason to believe that some other hydro-
carbon with an Identical retention time Is
present In the sample, then supplemental
confirmation of the vinyl chloride peak
through an absolute analytical technique.
such as mass spectroscopy. should be per-
formed.3*
2. Range and Sensitivity.
The lower limit of detection of vinyl chlo-
ride will vary according to the chromato-
graph used. Values reported include 1 X 10-;
mg and 4X10-' ag. with proper calibration.
the upper limit may be extended as needed.
3. Precision and Reproduclblllty.
An Interlaboratory comparison between
•even laboratories of three resin samples.
each split Into three parts, yleldea a standard
deviation of 2.63", for a sample with a mean
of 2.09 ppm. 4.18'; for a sample with a mean
of 1.66 ppm. and 5.29"« for a sample with it
mean of 62.66 ppm.
4. Safety.
Do not release vinyl chloride to the labora-
tory atmosphere during preparation of stand-
ards Venting or purging with VCM/air mix-
tures must be held to a minimum. Wnen
they are required, the vapor must be routed
to outside air. Vinyl chloride, even at low
ppm levels, must never be vented Inside the
laboratory. After vials have been analyzed.
the pressure within the vial must be vented
prior to removal from the Instrument turn-
table. Vials must be vented Into an activated
charcoal tube using a hypodermic needle to
prevent release of vinyl chloride Into the
laboratory atmosphere. The charcoal mutt
be replaced prior to vinyl chloride break-
through.
8. Apparatus.
5.1 Sampling.
6.1.1 Bottle*—«0 ml (8 o»). with waxed
lined screw on tops, for PVC samples.
5.1.3 Vials—60 ml Hypo-vials,1 sealed with
Teflon faced Tuf-Bond discs for water sam-
ples.
5.1.3 Electrical tape—or equivalent, to
prevent loosening of bottle tops.
5.2 Sample recovery.
5.2.1 Vials—With seals and caps. Perkln-
Elmer Corporation No. 106-O118, or equiva-
lent.
6.2.2 Analytical balance—Capable of
weighing to £0.001 gram.
6.3.3. Syringe. 100 »1—Precision Series
"A" No. 010026, or equivalent.
6.2.4 Vial Sealer, Perkln-Bmer No. 108-
0106 or equivalent.
5.3 Analysis.
5.3.1 Oas chromatograph—Parkin-Elmer
Corporation Model F-40 head-space ana-
lyzer. No. 104-0001. or equivalent.
5.3.2 diromatographic column. Stainless
steel. 2 m X 3.2 ntrn containing 0.4 percent
Oarbowax 1900 on Carbopak A, Parkin-Elmer
Corporation No. 106-0133. or equivalent.
Carbopak C can bx used In place of Carbopak
A. If methenol and/or acetaldehyde Is pres-
ent In the sample, a pair of Poropak Q col-
umns In series (1 m x 3.2 mm followed by
2 m X 3.3 mm) with provision for backflush
of the first column has been shown to pro*.
vide adequate separation of vinyl chlorlder
6.3.3 Thermometer—0 to 100* C. accurate
to ±0.1* C. Perkln-Elmer No. 105-0109 or
equivalent.
6.3.4. Sample tray thermostat system—
Perkln-Elmer No. 106-0103. or equivalent.
5JJS Septa—Sandwich type, for auto-
matic dosing, 13 """. Perkln-Elmer No. 106-
1008. or equivalent.
6.3.8 Integrator - recorder — Bewlett -
Packard Model 3380A. or equivalent.
6.3.7 Filter drier assembly (3)—Perkln-
Elmer No. 2230117. or equivalent.
6.3.8 Soap nlm flowmeter—Hewlett Pack-
ard No. 0101-0113. or equivalent.
6.4 Calibration.
6.4.1 Regulators—for required gas cylin-
ders.
6. Reagents.
8.1 Analysis.
(.1.1 Hydrogen gas—zero grade.
6.1.2 Nitrogen gas—zero grade.
6.13 Air—zero grade.
8.2 Calibration.
6.2.1 Cylinder standards (4). Oas mixture
standards (60. 600. 2.000. and 4,000 ppm vinyl
chloride In nitrogen cylinders) for which the
gas composition has been certified by the
manufacturer. Lower concentration stand-
ards should be obtained If lower concentra-
tions of vinyl chloride samples are expected.
as the Intent Is to bracket the sample con-
centrations with standards. The manufac-
turer must bsve recommended a maximum
shelf life for each cylinder so that the con-
centration does not change greater than ±:6
percent from the certified value. The date
of gas cylinder preparation, certified vinyl
chloride concentration and recommended
m.Timum shelf life must have been affixed
to the cylinder before shipment from the
manufacturer to the buyer. 3*
6.2.1.1 Cylinder standards certification.
The concentration of vinyl chloride In nitro-
gen in each cylinder must have been certi-
fied by the manufacturer by a direct analysis
of each cylinder using an analytical proce-
dure that the manufacturer had calibrated
on the day of cylinder analysis. The calibra-
tion of the analytical procedure shall, aa a
minimum have utilized a three-point cali-
bration curve. It Is recommended that the
manufacturer maintain two calibration
standards and use these standards in the
following way: (1) A high concentration
standard (between 4.000 and 8,000 ppm) (or
1 Mention of trade names on specific prod-
ucts does not constitute endorsement by the
environmental Protection Agency.
preparation of a calibration curve by an ap-
propriate dilution technique: (3) a low con-
centration standard (between 50 and 800
ppm) for verification of the dilution tech-
nique used. 3"
6.2.1.2 Establishment and verification of
calibration standards. The concentration of
each calibration standard must have been
established by the manufacturer using reli-
able procedures. Additionally, each calibra-
tion standard must have been verified by the
manufacturer by one of the following proce-
dures, and 'the agreement between the Ini-
tially determined concentration value and
the verification concentration value must be
within =5 percent: (1) Verification value de-
termined by comparison with a gas mixture
standard generated In a similar manner to
the procedure described In section 7.1 of
Method 106 for preparing gas mixture stand-
ards using 99.9+ percent vinyl chloride, or
(3) verification value obtained by having the
calibration standard analyzed by the Nation-
al Bureau of Standards. All calibration stand-
ards must be renewed on a tune Interval
consistent with the shelf life of the cylinder
standards sold.3*
7. Procedure.
T.I Sampling.
7.1.1 PVC sampling—Allow the resin or
slurry to flow from a tap on the tank or silo
until the tap line has been well purged. Ex-
tend a 60 ml sample bottle under the tap, fill.
and Immediately tightly cap the bottle. Wrap
electrical tape around the cap and bottle to
prevent the top from loosening. Place an
Identifying label on each bottle, and record
the date. tune, and sample location both on
Uw bottles and In a log book.
7.1 J Water sampling—Prior to use, the
50 ml vials (without the discs) must be
capped with aluminum foil and muffled at
400*C for at least one hour to destroy or
remove any organic matter that could In-
terfere with analysis. At the sampling loca-
tion fill the vials bubble-free, to overflowing
so tha: a convex meniscus forms at the top
The excess water Is displaced as the sealing
disc Is carefully placed. Teflon side down, en
the opening of the vial. Place the aluminum
seal over the disc and the neck of the vial
and crimp Into place. Affix an Identifying
label on the bottle, and record the date. time.
and sample location both on the vials and
in a log book. All samples must be kept re-
frigerated until analyzed.
7.2 Sample recovery. Samples must be run
within 24 hours.
72.1 Resin samples—The weight of the
resin used must be between 0.1 and 4.6 grams.
An exact weight must be obtained (±0.001
gram) for each simple. In the case of sus-
pension resins a volumetric cup can be pre-
pared which will hold the required amount
of sample. The ismple bottle Is opened, and
the cup volume of ream Is added to the tared
sample vial (Including septum and alumi-
num cap). The viil is Immediately sealed
and the exact sample weight Is then obtained.
Report this value on the data sheet as It Is
required for calculation of RVCM. In the
case of relatively dry resin samples (water
content <0.3 weight «-,). 100 ,,1 of distilled
wat*r must be Injected Into the vlil, after
sealing and weighing, using a 100 ul syringe.
In the case of dl'penlon re'lnv the cup
cannot be used. The sample Is Instead
weighed approximately In an aluminum dl«h.
transferred to the tared vial and weighed
accurately In the vial. The sample Is then
placed in the Perkln-Elmer head space ana-
lyzer (or equivalent) and conditioned for one
hour at 90>C.
Norxt Some aluminum vial caps have a
center section which must be removed prior
to placing Into sample tray. If not removed.
A-17
-------
Hrloui damage to the Injection needle will
occur.
7.2.2 Suspension resin Blurry and wet cake
samples—Slurry mu« be altered using a
•null Bucbner funnel with vacuum to yield
wet cake. The filtering process must be con-
tinued only as long as a steady stream of
water l« exiting from the funnel. Exce*«lve
filtration time could result In some loss of
VCM. The wet cake sample (0.10 to 4.5 grams)
Is added to a tared vial (Including septum
and aluminum cap I and Immediately sealed.
Sample wMght Is then determined to 3 deci-
mal places. The sample Is then pi iced In the
Perkln-Elmer head space analyzer (or equiva-
lent) and conditioned for one hour at 90"C.
A sample of wet cake la used to determine
TS (total solids i. This Is required for calcu-
lating the RVCM.
7.2.3 Dispersion resin slurry samples.—
This material should nof be filtered. Sample
must be thoroughly mixed. Using a tared
vial (Including septum and aluminum cap)
add approximately 8 drops (0.25 to 035
grams) of slurry or latex using a medicine
dropper. This should be done immediately
after mixing. Seal the vial is soon as possible.
Oetermm: sample weight accurate to 0.001
grams. Total sample weight must not exceed
0.80 grams. Condition the vial for one hour
at 80*C in the analyzer. Determine the TS
on the slurry sample (Section 7.3.5).
7.2.4 Inprocess wastewiter samples—
Using a tared vial (Including septum and
aluminum cap) quickly add approximately
1 cc of water using a medicine dropper. Seal
the vial as :oo i as possible Determine
sample weight accurate to 0.001 gram Con-
dition the vial for two hours at 90'C In the
analyzer.
7.3 Analysis.
7.3.1 Preparation of gas chrcmatograph—
Instill the chromatographlc column and con-
dition overnight at I50-C. Do not connect the
exit end of the column to the detector while
conditioning.
7.3.1.1 Flow rate adjustments—Adjust
flow rate* n follows:
a. Nitrogen carrier gas—Set regulator on
cylinder to read 50 pslg. Set regulator on
ehromatograph to 1.3 kg'cnv. Normal flows
at this pressure should be 25 to 40 cc.'minute.
Check with bubble flow meter.
b. Burner air supply—Set regulator on cyl-
inder to read 50 pslg. Set regulator on
ehromatograph to supply air to burner at a
rate between 250 and 300 cc/mlnute. Check
with bubble flowmeter.
c. Hydrogen suoply—Set regulator on cyl-
inder to read 30 pslg. Set regulator on
ehromatograph to supply approximately
36*5 cc/mlnute. Optimize hydrogen flow to
yield the most sensitive detector response
without extinguishing the flame. Check flow
with bubble meter and record thl« flow
7.3.1.2 Temperature adjustments—Set
temperatures as follows:
a. Oven (chromatographlc column). 60*
C.
b. Dosing line. 140* C.
c. Injection block, 140* C.
d. Sample chamber, water temperature,
90' C±I.O' C.
7.3.13 Ignition of flame lonlzatlon detec-
tor—Ignite the detector according to the
manufactvrer's Instructions.
7.3.1.4 Amplifier balance—Balance the
amplifier according to the manufacturer's
Instructions.
73.2 Programming the ehromatograph—
Progrim the ehromatograph as follows:
a. I—Dosing time—The normal setting Is
3 seconds.
b. A—Analysis time—The normal setting
Is 8 minutes. Certain types of samples eon-
tain high boiling material* which can cause
interference wtlh the vinyl chloride peak on
subsequent analyses. In these cases tke
analysis time must be adjusted to eliminate
the Interference. An automated backflush
system can also be used to solve this prob-
lem.
e. B—Flushing—The normal setting Is 0.2
minutes.
d. W—Stabilization time. The normal set-
ting Is 0.2 mlnutes.39
e. X—Number of analyses per sample—The
normal setting Is I.
7.3.3 Preparation of sample turntable—Be-
fore placing any sample Into turntable, be
certain that the center section of the alu-
minum cap has been removed. The numbered
simple bottles should be placed In the cor-
responding numbered positions In the turn-
table. Insert samples In the following order.
Positions 1 i: 2—Old 2000 ppm standards
for conditioning. These are necessary only
after the analyzer has not been used for 24
hours or longer.
Position 3—50 ppm standard, freshly pre-
pared.
Position 4—500 ppm standard, freshly pre-
pared.
Position 6—2000 ppm standard, freshly
prepared.
Position 0—4000 ppm standard, freshly pre-
pared.
Position 7—Sample No. 7 (This Is the first
sample of the day, but Is given as 7 to be con-
sistent with the turntable and the Integrator
printout.)
Alter all samples have been positioned, In-
eert the second set of 50. 500. 2000. and 4000
ppm standards. Samples. Including stand-
ards must be conditioned In the bath of
90' C for 1 hour (not to exceed 5 hours).
73.4 Start ehromatograph program—
When all samples. Including standards, hive
been conditioner1 at 90' C for I hour, start
the analysis program according to the manu-
facturers' instructions. These Instructions
must be carefully followed when starting
and stopping program to prevent damage to
the dosing asiembly.
73.5 Determination of total solids (TS).
For wet cake, slurry, resin solution, and
PVC latex samples, determine TS for ezch
sample by accurately weighing approxim-
ately 3 to 4 grams of sample In an aluminum
pan before and after placing In a drift
oven (105 to 110* C). Samples must be dried
to constant weight. After first weighing re-
turn the pan to the oven for a short pe-
riod of tline and then rewelgh to verify com-
plete dryress. TS Is then calculated as the
final sample weight divided by Initial sam-
ple weight.
8. Calibration.
Calibration Is to be performed each eight-
hour period when the Instrument Is used.
Each day. prlrr to ruining samples, the col-
umn should be conditioned by running two
of the previous days 2000 ppm standards.
8.1 Preparation of Standards.
Calibration standards are prepared by fill-
ing the vials with the vinyl chloride/nitro-
gen standards, rapidly seating the septum
and sealing with the aluminum cap. Use a
stainless steel line frcm the cylinder to the
vial. Do not use rubber or tygon tubing. The
sample line from the cylinder must be
purged (Into hocdt for several minutes prior
to filling vials After purging, reduce the flow
rate to approximately 500-1000 cc mm Place
end of tubing Into vial (near bottom i and
after one minute slowly remove tub:r.£ Place
septum m vial as socn ac possible to mini-
mize mixing air w;t>. si-ole After the stand-
ard vials are sealed. Inject 100U1 of distilled
water.
8.2 Preparation of chromatogrzph calibra-
tion curve.
Prepare two 50 ppm. two 500 ppm. two 2000
ppm. and two 4000 ppm standard samples
Run the calibration samples in exictly the
same manner as regular samples Plot A..
the integratcr area counts for ea:!: standard
sample vs Cr. the concentration of vinyl
chloride In each standard sample. Draw a
line of best fit through the points.
9. Calculations
9.1 Response factor.
From the calibration curve described In
Section 8.2. above, select tje value of Cr
that corresponds to A. for each sample Com-
pute the response factor. H/. for each sample.
u follows:
Equation 107-1
92 Residual vinyl chloride monomer con-
centration. or vinyl chloride monomer con-
centration.
Calculate C,,, a« follows:
„ _A,P. (.M.Y, \
C-~ H,T, (-m^~^T:)
wherp :
Equation 107-2
r,.te = Concentration of vinyl chloride
in the -ample, in ppm.
P,= Laboratory atmo'plirre prt?-
=urp. mm Hg.
T\ = Room tempernture, °K.
M,= Molecular weight of VCM
V i = Volume of vapor phase ivlal volume
less sample volume i.
m r = Weight of sample, grams.
A = Gos constant [62.360 (cc-tnm-mole-
degrees Kelvin) I
K = Henry's Law constant. For VCM in PVC
at 90 C. K = 6.S2 >. 10"> = ff. For VCM In
1 cc I approximate I waste water sample at
90' C. if = 50 • 10-« = K .
7. = Equilibration temperature. 'K.
II the following conditions are met. Equa-
tion 107-2 can be simplified as follows-
1. T . = 22 C (295 Kl
2. T.' = 90- (363- Kl
3. P. = 750 mm Hg.
*~ ' T.4 ~ ' 1A
where
V r = Vlal volume, cc (23.5).
5. Sample contains less than 0.5 percent
water.
1 Equation 107-3
The following general equation can be used for any sample which contains VCM. PVC and
water.
Equation 107-4
A-18
-------
when: Reaulte calculated using Equation 107-4
TS = Total solids, represent concentration based on the total
Hoi.: K , must b« determined for sample. ""P14; T° obtain results baaed on dry PVC
with a vapor volume to liquid volume ratio content, divide by TS.
other than 33.5 to 1. Tills ratio can be ob- P" • l~cc wastewater sample (that la,
talned by adjusting the sample weight 33.5 to 1 vapor volume to liquid volume
through giving consideration to the total ratio). It . Is 8.0 x 10-'. Thus. Eiuatlon 107-
aollds and density ot the PVC. 4 can be simplified to the following:
C,,.-4-' r5'988X1°''+(2.066X 10-«)I Equation 107-5
K, L "i< J
(Bece. 113 and 301 (a) of the Clean Air Act. 43 C.S.C. 18S7C-7 and 1867g(a) .)3*
10. References.
a. Keddual Vinyl Chloride Monomer Con-
tent of Polyvlnyl Chloride Resins and Wet
Cake Samples. B. F. Qoodrlch Chemical Co.
Standard Test Procedure No. 1005-T. B. f.
Ooodrlch Technical Center, Avon Lake, Ohio.
January 30. 1975.
b. Berens. A. R, •The Solubility of Vinyl
Chloride In Polyvlnyl Chloride." ACS-Olvl-
slon of Polymer Chemistry, Polymer Pre-
prints 15 (3): 197.1974.
c. Berens, A. R.. -The Diffusion of Vinyl
Chloride in Polyvlnyl Chloride." ACS-Dlvl-
slon of Polymer Chemistry, Polymer Pre-
prints 15 (3) : 303, 1974.
d. Berens. A. R.. L. B. CMder, C. J. Toma-
nek and J. M. Whitney, Analysis for Vinyl
Chloride in PVC Powders by Head-Space Qas
Chromatograpby," to be published.
(Sec. 114 of the Clean Air Act as amended
(43 OAC. 7414)). 4W7
A-19.
-------
APPENDIX B
REGIONAL EPA AND INDUSTRIAL CONTACTS
-------
Table B-l. REGIONAL EPA AND INDUSTRIAL CONTACTS
Regi on/Company/Di vi si on
Date of
meeting
Place
Contact
Purpose of
meeti ng
CO
I
EPA/DSSE
Region I (Boston)
Region II (New York)
Region III (Philadelphia)
6-19-80 Washington,DC Rich Biondi
8-13-80 Boston
8-12-80 New York
9-16-80 Philadelphia
Cathy McNair
Michael Pucci
Jean Thompson
Obtain input from DSSE
personnel as to areas
of concern to be incor-
porated into the VC
Review Study
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
(continued)
-------
Table B-l. Continued
Regi on/Company/Di vi si on
Date of
meeting
Place
Contact
Purpose of
meeting
Region IV (Atlanta)
8-3-80
Region V (Chicago)
8-19-80
CD
ro
Region VI (Dallas)
7-23-80
10-27-80
South Coast Air Quality
Monitoring Division (SCAQMD)
Society of the Plastics
Industry
7-31-80
Atlanta
Wayne Aronson
Chicago
Bruce Varner
Dallas
Martin Brittain
10-28-80 El Monte, CA
Doug Newton
EPA, Durham, NC Robert Laundrie
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
Discuss the VC Review
Study and obtain input
from the Region to the
review study's areas
of concern.
(Region IX has designated
authority to SCAQMD)
Discuss VC Review Study;
discuss SCAQMD1s Rule
1005.1 which supercedes
the VC NESHAP.
Discuss the scope of the
VC Review Study.
(continued)
-------
Table B-l. Continued
Regi on/Company/Di vi si on
Date of
meeting
Place
Contact
Purpose of
meeting
Conoco Chemical Company
8-7-80
Lake Charles, LA Joseph Ledvina
Conoco Chemical Company
10-17-80 TRW, RTP
Joseph Ledvina
CD
I
CO
Diamond Shamrock Corp.
8-6-80
Deer Park, TX Alex Evins
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
containment devices.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
(continued)
-------
Table B-l. Continued
Region/Company/Division
Diamond Shamrock Corporation
Date 'of
meeting
8-6-80
Place
Independence ,TX
Contact
Alex Evins
Purpose of
meeting
Become familiar
with
Dow Chemical Company
8-5-80
Oyster Creek, TX Robert Oubre
CO
Dow Chemical Company
9-11-80
Midland, MI
Robert Ammons
General Tire & Rubber Co,
9-10-80
Astabula, OH
Robert Laundrie
new and existing air
pollution control
techniques currently
being used to control
VC emissions: discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions:, discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
(continued)
-------
Table B-l. Continued
Region/Company/Division
Date of
meeting
Place
Contact
Purpose of
meeting
B. F. Goodrich Chemical Div.
8-20-80
Henry, ILL.
W. C. Hoi brook
B. F. Goodrich Chemical Div.
9-17-80
Pedricktown, NJ
W. C. Hoi brook
CD
I
on
B. F. Goodrich Chemical Div. 10-30-80
Cleveland, OH
W. C. Hoi brook
Great American Chemical Corp. 8-13-80
Fitchburg, MASS
Russ Mercier
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
SCAQMD Rule 1005.1.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
(continued)
-------
Table B-l. Concluded
Regi on/Company/Di vi s i on
Date of
meeting
Place
Contact
Purpose of
meeting
Hooker Chemical Co.
9-15-80 Burlington, NO
Harold Dubec
Shintech, Inc.
8-5-80
Freeport, TX
John Yonge
to
en
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
Become familiar with
new and existing air
pollution control
techniques currently
being used to control
VC emissions; discuss
plant processes.
-------
APPENDIX C
CURRENT INDUSTRIAL SOURCES
-------
OPERATING ETHYLENE DICHLORIDE/VINYL CHLORIDE PLANTS
Region
Plant
Location
Process
o
IV
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
IX
B. F. Goodrich
Borden Chemical
Conoco Chemical
Diamond Shamrock
Diamond Shamrock
Dow Chemical
Dow Chemical
Dow Chemical
Ethyl Corporation
Georgia Pacific
ICI Americas
Monochem, Inc.
PPG Industries
Shell Chemical
Shell Chemical
Vulcan Materials
Stauffer Chemicals
Calvert City, Kentucky
Geismar, Louisiana
Westlake, Louisiana
*
Deer Park, Texas
LaPorte, Texas
Plaquemine, Louisiana
Oyster Creek, Texas
Freeport, Texas
Baton Rouge, Louisiana
Plaquemine, Louisiana
Baton Rouge, Louisiana
Geismar, Louisiana
Lake Charles, Louisiana
Norco, Louisiana
Deer Park, Texas
Geismar, Louisiana
Long Beach, California
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC (2)
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC/VC
EDC only
EDC/VC
Began operation since promulgation of the regulation (October, 1976)
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OPERATING POLYVINYL CHLORIDE PLANTS
Region
Plant
Location
Polymerization process
o
i
ro
I Borden, Inc.
I Great American
I International Materials
II B. F. Goodrich
II Goodyear Tire & Rubber
II Hooker Chemical
II Pantasote
II Tenneco
II Tenneco
II Union Carbide
III Diamond Shamrock
III Firestone
III Firestone
III Pantasote
III Stauffer
IV Air Products
IV Air Products
IV B. F. Goodrich
IV Conoco
IV Union Carbide
Leominster, Mass.
Fitchburg, Mass.
New Bedford, Mass.
Pedricktown, N.J.
Niagara Falls, N.Y.
Burlington, N. J.
Passaic, N. J.
Burlington, N. J.
Flemington, N. J.
Sommerset, N. J.
Delaware City, Del.
Perryville, Md.
Pottstown, Pa.
Point Pleasant, W. Va.
Delaware City, Del.
Calvert City, Ky.
Pensacola, Fla.
Louisville, Ky.
Aberdeen, Miss.
Tucker, Georgia
Suspension, latex
Suspension
Suspension
Suspension, dispersion,
Suspension, dispersion
Bulk
Suspension
Suspension, dispersion
Suspension
Latex
Suspension, dispersion
Suspension, dispersion
Suspension, dispersion
Suspension
Suspension, dispersion
Suspension, latex
Suspension
Suspension, latex
Suspension
Latex
bulk
Began operation since promulgation of the regulation (October, 1976).
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OPERATING POLYVINYL CHLORIDE PLANTS (Continued)
Region
Plant
Location
Polymerization process
o
i
CO
V
V
V
V
V
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
VI
IX
IX
IX
B. F. Goodrich
B. F. Goodrich
Borden
Dow
General Tire
B. F. Goodrich
Certainteed
Conoco
Conoco
Diamond Shamrock
Ethyl
Firestone
Georgia Pacific
Shintech
Tenneco
Union Carbide
B. F. Goodrich
Stauffer
Union Carbide
Henry, 111.
Avon Lake, OH
Illiopolis, 111.
Midland, Mich.
Ashtabula, OH
Plaquemine, LA
Sulphur, LA
Ponca City, OK
Oklahoma City, OK
Deer Park, TX.
Baton Rouge, LA
Addis, LA
Plaquemine, LA
Freeport, TX
Pasadena, TX
Texas City, TX
Long Beach, CA
Long Beach, CA
Torrance, CA
Suspension, dispersion
Suspension, dispersion, latex
Suspension, dispersion
Suspension, dispersion
Suspension
Bulk
Bulk
*
Suspension
Suspension
Suspension, dispersion
Suspension, dispersion
Suspension
Suspension
Suspension
Suspension
Solution
Suspension
Suspension
Latex
Began operation since promulgation of the regulation (October, 1976).
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3-82-003
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Vinyl Chloride
Standards
—A Review of National Emission
5. REPORT DATE
February 1982
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
TRW, Incorporated, P.O-. Box 13000
Research Triangle Park, NC 27709
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Tiangle Park, NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
Washington, D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA 200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This VC NESHAP Review Study assesses the current VC regulation
through an investigation of emission control techniques and techno-
logical developments in the industry. The study encompasses evaluations
of existing and new control technologies, sources not regulated by the
standard, and enforcement and compliance experience since promulgation
of the standard. Information and data evaluated during this study were
obtained through literature searches, plant visits, and interviews with
industrial representatives and EPA Regional Office personnel. The
results of this review study will form the basis for possible revison of
the existing standard.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
13 B
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
244
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-] (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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