EPA
October 1974
BACKGROUND INFORMATION
FOR STANDARDS OF PERFORMANCE:
COAL PREPARATION PLANTS
VOLUME 1: PROPOSED STANDARDS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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EPA 450/2-74-021a
BACKGROUND INFORMATION
FOR STANDARDS OF PERFORMANCE:
COAL PREPARATION PLANTS
VOLUME 1: PROPOSED STANDARDS
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
October 1974
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations as supplies permit from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22161.
Publication No. EPA-450/2-74-021a
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PREFACE
A. Purpose of this Report
Standards of performance under section 111 of the Clean
Air Act— are proposed only after a very detailed investigation
of air pollution control methods available to the affected
industry and the impact of their costs on the industry. This
report summarizes the information obtained from such a study
of coal preparation plants. It is being distributed in
connection with formal proposal of standards for that industry
in the Federal Register. Its purpose is to explain the
background and basis of the proposal in greater detail than
could be included in the Federal Register, and to facilitate
analysis of the proposal by interested persons, including those
who may not be familiar with the many technical aspects of the
industry. For additional information, for copies of documents
(other than published literature) cited in the Background
Information Document, or to comment on the proposed standards,
contact Mr. Don R. Goodwin, Director, Emission Standards and
Engineering Division, United States Environmental Protection
Agency, Research Triangle Park, North Carolina 27711 [(919)688-8146].
B. Authority for the Standards
Standards of performance for new stationary sources are
promulgated in accordance with section 111 of the Clean Air Act
(42 USC 1857c-6), as amended in 1970. Section 111 requires
T7Sometimes referred to as "new source performance
standards" (NSPS).
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the establishment of standards of performance for new stationary
sources of air pollution which "... may contribute significantly
to air pollution which causes or contributes to the endangerment
of public health or welfare." The Act requires that standards
of performance for such sources reflect "... the degree of
emission limitation achievable through the application of the best
system of emission reduction which (taking into account the cost
of achieving such reduction) the Administrator determines has
been adequately demonstrated." The standards apply only to
stationary sources, the construction or modification of which
commences after regulations are proposed by publication in
the Federal, Register.
Section 111 prescribes three steps to follow in establishing
standards of performance.
1. The Administrator must identify those categories of
stationary sources for which standards of performance
will ultimately be promulgated by listing them in the
Federal Register.
2. The regulations applicable to a category so listed must
be proposed by publication in the Federal Register within
120 days of its listing. This proposal provides Interested
persons an opportunity for comment.
3. Within 90 days after the proposal, the Administrator
must promulgate standards with any alterations he deems
appropriate.
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It Is Important to realize that standards of performance,
by themselves, do not guarantee protection of health or welfare;
that 1s, they are not designed to achieve any specific air
quality levels. Rather, they are designed to reflect best
demonstrated technology (taking into account costs) for the
affected sources. The overriding purpose of the collective
body of standards is to maintain existing air quality and to
prevent new pollution problems from developing.
Previous legal challenges to standards of performance for
Portland cement plants, steam generators, and sulfuric acid
plants have resulted in several court decisions-/ of Importance
in developing future standards. In those cases, the principal
issues were whether EPA: (1) made reasoned decisions and
fully explained the basis of the standards, (2) made available
to interested parties the information on which the standards
were based, and (3) adequately considered significant comments
from Interested parties.
Among other things, the court decisions established:
(1) that preparation of environmental impact statements 1s not
necessary for standards developed under section 111 of the Clean
Air Act because, under that section, EPA must consider any
counter-productive environmental effects of a standard 1n
determining what system of control 1s "best;" (2) 1n considering
costs 1t 1s not necessary to provide a cost-benefit analysis;
27 Portlant Cement Association v Ruckelshaus, 486 F. 2nd
375 (D.C. Cir. 1973); Essex Chemical Corp. v Ruckelshaus, 486
F. 2nd 427 (D.C. Cir. 1973).
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(3) EPA is not required to justify standards that require different
levels of control in different industries unless such different
standards may be unfairly discriminatory; and (4) it is
sufficient for EPA to show that a standard can be achieved
rather than that it has been achieved by existing sources.
Promulgation of standards of performance does not prevent
State or local agencies from adopting more stringent emission
limitations for the same sources. On the contrary section 116
of the Act (42 USC 1857-D-l) makes clear that States and other
political subdivisions may enact more restrictive standards.
Furthermore, for heavily polluted areas, more stringent standards
may be required under section 110 of the Act (42 USC 1857c-5) in
order to attain or maintain national ambient air quality standards
prescribed under section 109 (42 USC 1857c-4). Finally, section 116
makes clear that a State may not adopt or enforce less stringent
standards than those adopted by EPA under section 111.
Although it is clear that standards of performance should be
1n terms of limits on emissions where feasible,—' an alternative
method of requiring control of air pollution is sometimes
necessary. In some cases physical measurement 'of emissions
from a new source may be impractical or exorbitantly expensive.
37"'Standards of performance,1 ... refers to the degree of
emission control which can be achieved through process changes,
operation changes, direct emission control, or other methods. The
Secretary [Administrator] should not make a technical judgment
as to how the standard should be implemented. He should determine
the achievable limits and let the owner or operator determine the
most economical technique to apply." Senate Report 91-1196.
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For example, emissions of hydrocarbons from storage vessels for
petroleum liquids are greatest during storage and tank filling.
The nature of the emissions (high concentrations for short
periods during filling and low concentrations for longer
periods during storage) and the configuration of storage tanks
make direct emission measurement highly impractical. Therefore,
a more practical approach to standards of performance for
storage vessels has been equipment specification.
C. Selection of Categories of Stationary Sources
Section 111 directs the Administrator to publish and from
time to time revise a list of categories of sources for which
standards of performance are to be proposed. A category is to
be selected "... if [the Administrator] determines it may contribute
significantly to air pollution which causes or contributes to the
endangerment of public health or welfare."
Since passage of the Clean Air Amendments of 1970, considerable
Attention has been given to the development of a system for
assigning priorities to various source categories. In brief,
the approach that has evolved is as follows.
First, we assess any areas of emphasis by .-considering the
broad EPA strategy for implementing the Clean Air Act. Often,
these "areas" are actually pollutants which are primarily emitted
by stationary sources. Source categories which emit these
pollutants are then evaluated and ranked by a process involving
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such factors as (1) the level of emission control (1f any)
already required by State regulations; (2) estimated levels
of control that might result from standards of performance for the
source category; (3) projections of growth and replacement ,
of existing facilities for the source category; and (4) the
estimated Incremental amount of air pollution that could be
prevented, 1n a preselected future year, by standards of
performance for the source category.
After the relative ranking is complete, an estimate
must be made of a schedule of activities required to develop
a standard. In some cases, 1t may not be feasible to immediately
develop a standard for a source category with a very high
priority. This might occur because a program of research
and development is needed or becaMse techniques for sampling
and measuring emissions may require refinement before study
of the Industry can be initiated. The schedule of activities
must also consider differences in the time required to complete
the necessary investigation for differenl source categores.
Substantially more time may be necessary, for example, if a
number of pollutants must be investigated in a single source
category. Even late in the development process the
schedule for completion of a standard may change. For
example, inability to obtain emission data from
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well-controlled sources In time to pursue the development
process in a systematic fashion may force a change in
scheduling.
Selection of the source category leads to another major
decision: determination of the types of sources or facilities
to which the standard will apply. A source category often
has several facilities that cause air pollution. Emissions
from some of these facilities may be insignificant and, at the
same time, very expensive to control. An investigation of
economics may show that, within the costs that an owner could
reasonably afford, air pollution control is better served by
applying standards to the more severe pollution problems. For
this reason (or perhaps because there may be no adequately
demonstrated system for controlling emissions from certain
facilities), standards often do not apply to all sources within
a category. For similar reasons/the standards may not apply
to all air pollutants emitted by such sources. Consequently,
although a source category may be selected to be covered by a
standard of performance, treatment of some of the pollutants or
facilities within that source category may be deferred.
D. Procedure for Development of Standards of Performance
Congress mandated that sources regulated under section 111
of the Clean Air Act be required to utilize the best practicable
air pollution control technology that has been adequately
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demonstrated at the time of their design and construction. In so
doing, Congress sought to:
1. maintain existing high-quality air,
2. prevent new air pollution problems, and
3. ensure uniform national standards for new facilities.
The selection of standards of performance to achieve the
intent of Congress has been surprisingly difficult. In general,
the standards must (1) realistically reflect best demonstrated
control practice; (2) adequately consider the cost of such control;
(3) be applicable to existing sources that are modified as well
as new installations; and (4) meet these conditions for all
variations of operating conditions being considered anywhere in
the country.
A major portion of the program for development of standards
is spent identifying the best system of emission reduction which
"has been adequately demonstrated" and quantifying the emission
rates achievable with the system. The legislative history of
section 111 and the court decisions referred to above make clear
that the Administrator's judgment of what is adequately demonstrated
is not limited to systems that are in actual rodtine use.
Consequently, the search may include a technical assessment
of control systems which have been adequately demonstrated but
for which there is limited operational experience. To date,
determination of the "degree of emission limitation achievable"
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has been commonly based on (but not restricted to) results
of tests of emissions from existing sources. This has
required worldwide investigation and measurement of emissions
from control systems. Other countries with heavily populated,
industrialized areas have sometimes developed more effective
systems of control than those used in the United States.
Because the best demonstrated systems of emission reduction may
not be in widespread use, the data base upon which the standards
are established will necessarily be somewhat limited. Test
data on existing well-controlled sources are an obvious starting
point in developing emission limits for new sources. However,
since the control of existing sources generally represents
retrofit technology or was originally designed to meet an
existing State or local regulation, new sources may be able
to meet more stringent emission standards. Accordingly, other
information must be considered and judgment is necessarily
involved in setting proposed standards.
Since passage of the Clean Air Amendments of 1970, a
process for the development of a standard has evolved. In
general, it follows the guidelines below.
1. Emissions from existing well-controlled sources
are measured.
2. Data on emissions from such sources are assessed with
consideration of such factors as: (a) the representativeness
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of the source tested (feedstock, operation, size, age,
.etc.); (b) the age and maintenance of the control
equipment tested (and possible degradation in the
efficiency of control of similar new equipment even
with good maintenance procedures); (c) the design
uncertainties for the type of control equipment being
considered; and (d) the degree of uncertainty affecting
the judgment that new sources will be able to achieve
similar levels of control.
3. During development of the standards, information from
pilot and prototype installations, guarantees by vendors
of control equipment, contracted (but not yet constructed)
projects, foreign technology, and published literature
are considered, especially for sources where "emerging"
technology appears significant.
4. Where possible, standards are set at a level that is
achievable with more than one control technique or
licensed process.
5. Where possible, standards are set to encourage (or at least
permit) the use of process modificatio'ns or new processes
as a method of control rather than "add-on" systems of
air pollution control.
6. Where possible, standards are set to permit use of
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systems capable of controlling more than one pollutant
(for example, a scrubber can remove both gaseous and
partlculate matter emissions, whereas an electrostatic
precipitator is specific to particulate matter).
7. Where appropriate, standards for visible emissions are
established in conjunction with mass emission standards.
In such cases, the standards are set in such a way that
a source meeting the mass emission standard will be able
to meet the visible emission standard without additional
controls. (In some cases, such as fugitive dust, there
is no mass standard).
Finally, when all pertinent data are available, judgment
is again required. Numerical tests may not be transposed directly
Into regulations. The design and operating conditions of those
sources from which emissions were actually measured cannot be
reproduced exactly by each new source to which the standard of
performance will apply.
E. How Costs are Considered
Section 111 of the Clean Air Act requires that cost be
considered in setting standards of performance: To do this requires
an assessment of the possible economic effects of implementing
various levels of control technology in new plants within a
given industry. The first step in this analysis requires the
generation of estimates of installed capital costs and annual
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operating costs for various demonstrated control systems,
each control system alternative having a different overall
control capability. The final step in the analysis 1s to
determine the economic impact of the various control alternatives
upon a new plant in the industry. The fundamental question to
be addressed in this step is whether or not a new plant would
be constructed given that a certain level of control costs would
be Incurred. Other Issues that would be analyzed 1n this step
would be the effects of control costs upon product prices and the
effects on product and raw material supplies and producer
profitability.
The economic Impact upon an industry of a proposed standard
1s usually addressed both 1n absolute terms and by comparison
wfth the control costs that would be incurred as a result
of compliance with typical existing State control regulations.
This Incremental approach is taken since a new plant would
be required to comply with State regulations 1n the absence
of a Federal standard of performance. This approach requires
a detailed analysis of the Impact upon the Industry resulting
from the cost differential that usually exists between the
standard of performance and the typical State standard.
It should be noted that the costs for control of air
pollutants are not the only control costs considered. Total
environmental costs for control of water pollutants as well
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as air pollutants are analyzed wherever possible.
A thorough study of the profitability and price-setting
mechanisms of the industry is essential to the analysis so
that an accurate estimate of potential adverse economic impacts
can be made. It is also essential to know the capital requirements
placed on plants in the absence of Federal standards of performance
so that the additional capital requirements necessitated by these
standards can be placed in the proper perspective. Finally, it
is necessary to recognize any constraints on capital availability
within an industry as this factor also influences the ability
of new plants to generate the capital required for installation
of the additional control equipment needed to meet the standards
of performance.
The end result of the analysis is a presentation of costs
and potential economic impacts for a series of control
alternatives. This information is then a major factor which
the Administrator considers in selecting a standard.
F. impact on Existing Sources
Proposal of standards of performance may affect an existing
source in either of two ways. First, if modiffed after
proposal of the standards, with a subsequent increase in
air pollution, it is subject to standards of performance as
if 1t were a new source. (Section 111 of the Act defines a
new source as "any stationary source, the construction or
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modification of which is commenced after the regulations are
proposed.")^/
Second, promulgation of a standard of performance requires
States to establish standards of performance for the same pollutant
for existing sources in the same industry under section lll(d) of
the Act; unless the pollutant limited by the standard for new
sources is one listed under section 108 (requiring promulgation of
national ambient air quality standards) or one listed as a
hazardous pollutant under section 112. If a State does not act,
EPA must establish such standards. Regulations prescribing
procedures for control of existing sources under section lll(d)
will be proposed as Subpart B of 40 CFR Part 60.
G. Revision of Standards of Performance
Congress was aware that the level of air pollution control
achievable by any industry may improve with technological
advances. Accordingly, section 111 of the Act provides that
the Administrator may revise such standards from time to time.
Although standards proposed and promulgated by EPA under section 111
are designed to require installation of the "... best system of
emission reduction ... (taking into account the cost)..."
the standards will be reviewed periodically. Revisions will be
proposed and promulgated as necessary to assure that the.standards
|7Specific provisions dealing with modifications to existing
facilities are being proposed by the Administrator under the
General Provisions of 40 CFR Part 60.
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continue to reflect the best systems that become available
in the future. Such revisions will not be retroactive but
will apply to stationary sources constructed or modified after
proposal of the revised standards.
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TABLE OF CONTENTS
Section Pa9e
Introduction 1
Summary of Proposed Standards 2
Description of Process 3
Wet Cleaning Systems 4
Dry Cleaning Systems 7
Emissions and Methods of Control 9
Wet Cleaning Systems 9
Dry Cleaning Systems 10
Existing Air Pollution Standards 10
Rationale for Proposed Standards H
Selection of Pollutants for Control 11
Selection of Units for Standard 13
Selection of Sampling and Analytical Methods 16
Discussion of Standards Development 17
Wet Cleaning Systems 23
Dry Cleaning Systems 27
Visible Emission Data 29
Conclusions 30
Environmental Impact of Proposed Standards 31
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Economic Impact of Proposed Standards 32
References 39
Bibliographic Data Sheet 40
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INTRODUCTION
*
"Coal preparation" is one segment of the coal industry. Coal
preparation encompasses operations between the mining of raw coal
and the distribution of product coal.
The extent of preparation and type of processing depend upon
the physical character and chemical composition of the raw coal and
the customer specifications on product coal. Coal preparation is
therefore a function of the demand for an improved quality product.
Coal preparation plants were specifically named as major sources
of air pollution in 40 CFR Part 52 "Prevention of Significant Air
Quality Deterioration," published as proposed in the Federal Register.
July 16, 1973. One study on emissions from coal preparation esti-
mated that particulate emissions from thermal dryers alone exceeded
150,000 tons in 1968.
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SUMMARY OF PROPOSED STANDARDS
»
Standards of performance are being proposed for new coal
preparation plants. The proposed standards would limit emissions
of particulates (including visible emissions) from the following
sources, which are the affected facilities: thermal driers,
pneumatic coal-cleaning equipment (air tables), coal processing
and conveying equipment (including breakers and crushers), screen-
ing (classifying) equipment, coal storage, coal transfer points,
and coal loading facilities.
The standards apply at the point(s) where undiluted gases are
discharged from the air pollution control system or from the affected
facility if no air pollution control system is utilized. If air or
other dilution gases are added prior to the measurement point(s),
the owner or operator must provide a means of accurately determining
the amount of dilution and correcting the pollutant concentration to
the undiluted basis.
The proposed standards for these sources would limit parti oil ate
emissions to the atmosphere as follows:
Particulate Matter from Thermal Driers
1. No more than 0.070 gram per dry standard cubic meter (0.031 grain
per dry standard cubic foot).
2. Less than 30 percent opacity.
Particulate Matter from Pneumatic Coal-Cleaning Equipment
1. No more than 0.040 gram per dry standard cubic meter (0.018
grain per dry standard cubic foot).
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2. Less than 20 percent opacity.
Particulate Matter from Other Affected Facilities
Less than 20 percent opacity.
DESCRIPTION OF PROCESS
Coal in its natural state contains impurities such as sulfur,
clay, rock, shale and other inorganic materials, generally called
ash. Coal mining also adds more impurities.in the form of mine rock,
dirt, tramp iron and wood. To remove these impurities, coal prepara-
tion plants utilize the difference in specific gravities to separate
coal from the heavier contaminants.
Since this separation depends on the coal and impurities already
being separate entities, the larger coal lumps must be.broken up to
free entrapped impurities. Thus impurities which occur as finely
divided mixtures in coal are more difficult to remove than the coarser
materials, e.g., pyritic sulfur is much more difficult to remove than
rock or shale. Scalpers and magnets remove wood and iron prior to
size reduction.
Coal preparation plants prepare various types of coal in response
to market demand. Three types of preparation plants are common:
(1) "complete preparation," those that clean both coarse and fine
coal; (2) "partial preparation," those that clean only coarse coal;
and (3) "coal crushing," where the coal is merely crushed to a
specified maximum size. Since all features of the two other types
are incorporated into the complete preparation plant, only it will
be described.
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Figure 1 is a schematic diagram of a complete coal preparation
facility. Coal from the mine is broken and screened to remove over-
size material, then stored until the batch processing in the plant
is begun. Secondary breaking or crushing is sometimes necessary to
ensure good separation of coal from impurities in the cleaning plant.
Classifying screens separate coal particles by size and route them
to various cleaning processes represented by the "cleaning process"
portion of the diagram. In general this cleaning process may be
wet, dry, or a combination of both.
Wet Cleaning Systems2
Wet cleaning systems utilize centrifugal or gravity separation
of heavier rejects from coal (see Figure 2). None of the variety
of wet cleaning methods emit pollutants. However, the auxiliary pro-
cesses of handling and drying can be major sources. After the coal
is wetted by the cleaning process, it is dried mechanically by de-
watering screens followed by centrifugal driers. Removing excess
moisture from coal decreases shipping costs, increases the higher
heating value of coal, and prevents freezing in very cold climates.
Where customer demand is for low surface moisture (3 to 6 percent)
of finer coal sizes, secondary drying is required. Such low moisture
levels can best be accomplished by thermal drying. It appears that
new coal preparation plants that install thermal driers will use a
fluid-bed type.
In the fluid-bed drier, hot combustion gases from a coal-fired
furnace are passed upward through a moving bed of wet coal of fine
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BREAKER
FROM
MINE
STORAGE
SILO
FIRST
SCREENS
CRUSHER
SECOND CLEANING
SCREEN PROCESS
EQUIPMENT
STORAGE
SILO
LOAD-
OUT
Figure 1. Flow diagram for coal cleaning plant (for section A - A', see Figures 2 and 3).
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RAW COAL IN
TO
STORAGE
Figure 2. Wet cleaning circuit process.
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particle size. As the bed fluidizes, the coal is dried as the
fine particles come into intimate contact with the hot gases.
Particulate emissions occur predominately from ultrafine (-200 mesh)
coal particles which are entrained and carried from the drier by the
combustion gases.
The primary control device, a dry centrifugal collector (orig-
inally justified primarily to recover product, thereby increasing
yield), can retain up to 95 percent of the entrained fines. These
are returned to the product coal. All secondary emission control
systems are wet collectors. The high dew point and explosion potential
of the exhaust gas make other emission control systems impractical.
The dried coal is conveyed to storage where it remains until being
loaded into railroad cars, trucks, or barges.
Dry Cleaning Systems
Since 1966, all dry coal cleaning systems in operation have used
2
pulsating air columns to separate coal from reject material. Figure
3 is a schematic diagram of such a system. Coal containing refuse
particles enters the air table where it is stratified into a bed by
pulsating air. The heavier refuse settles in a layer beneath the
coal. As the bed travels forward, the refuse drops into packets or
wells from which it is withdrawn to the refuse bin. The upper layer
of coal is removed as it completes its travel over the slowly moving
bed of refuse. Dust, entrained and airborne by the pulsating air,
is drawn into an overhead hood to be recovered by cyclone dust
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RAW COAL IN
CO
SECONDARY
COLLECTORS
PRIMARY
COLLECTORS
TO
/ STORAGE SILO
Figure 3. Dry cleaning process.
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collectors which have been installed based on economical product
recovery. Secondary collectors, which are added for control of air
pollution, are usually fabric filters.
EMISSIONS AND METHODS OF CONTROL
Emissions from uncontrolled coal preparation plants include
NO , SO , CO and fine particulates from thermal drying. Particulate
A C>
emissions come from crushing, screening, storage, transfer, grinding,
conveying, or loading operations. Particulate emissions, at times
severe and highly visible, increase as the surface moisture in the
coal decreases. Their control requires good capture of the emissions
which must then be fed to a control device. None of the plants
attempt to control combustion products or S02>
Met Cleaning Systems
Thermal driers in a coal plant which uses wet cleaning incorporate
cyclones as an integral part of the coal cleaning process. Potential
particulate emissions upstream of the cyclone have been measured in
the range of 50 to 200 grains per dry standard cubic foot (gr/dscf)
for fluid-bed driers.3 Emissions measured downstream ranged from
0.7 to 14 gr/dscf. An average emission factor often used for fluid-
bed driers without secondary control is 3.0 gr/dscf. (With 3.0
gr/dscf, a 500-ton-per-hour thermal drier would emit over 5,000
pounds of particulates per hour.)
Well-controlled thermal driers with high-efficiency, venturi-
type wet scrubbers reduce particulate emissions to less than 0.03
gr/dscf. This is equivalent to about 99 percent control efficiency.
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Dry Cleaning Systems
Implementation of new health and safety regulations within the
coal mines resulted in addition of increasing amounts of water to
coal to minimize dust inhalation and reduce its explosive hazard.
This has resulted in a rise in the surface moisture of coal from
underground mines and has caused a corresponding reduction in emis-
sions from air tables which have a control device. Measurements
prior to 1970 indicated grain loadings of 0.16 gr/dscf from plants
which had only a primary control device. A 70-tons-per-hour air
table with such control could emit up to 50.pounds per hour. In
1973 this same facility would emit only 10-15 pounds per hour. Fabric
filter secondary collectors have been reported to further reduce emis-
sions to less than 0.01 gr/dscf.3 A fabric filter collector is a dry
process and all dust which it recovers becomes part of the product.
EXISTING AIR POLLUTION STANDARDS
Most States do not have specific air pollution limitations for
coal preparation plants but rather make them subject to a general
process weight regulation. This type of restriction is not uniform.
For example, under the most restrictive such regulation, a 500-tons-
per hour thermal drier could emit 70 pounds of particulate each hour,
approximately equivalent to an exit-gas concentration of 0.035 gr/dscf.
A smaller air table with a capacity of 75 tons per hourVould be allowed
to emit 48 pounds per hour, an exit-gas concentration of approximately
0.150 gr/dscf.
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Three States have codes applicable exclusively to coal prepara-
tion plants.4 The most restrictive is 0.02 gr/dscf for thermal driers
and air tables with capacities above 100 tons per hour. However, it
permits exit concentrations to increase with decreasing capacity.
All coal-producing States have a general visible emission re-
striction that limits all sources to a maximum 20 percent opacity.
RATIONALE FOR PROPOSED STANDARDS
Selection of Pollutants for Control
The only pollutant evolved from air tables is particulate. Emis-
sions from thermal driers include combustion products from the coal-
fired furnace, but these quantities of emissions are a small fraction
of the particulates entrained by the flue gases passing through the
fluidized bed of coal. Initial emission samples from thermal driers
were analyzed for products of combustion and heavy metals. Table 1
presents the results of the analyses of combustion products. The table
permits a comparison with the standards of performance for coal-fired
power plants.
Both NOX and S02 emissions were found below the performance
standards required of new coal-fired power plants. Admittedly the
driers tested were processing (and using as fuel) low-sulfur coal.
However, only 12 percent of all thermally dried coal is greater than
2 percent sulfur, primarily because thermal drying of lower quality
coals is not generally an economically attractive alternative.
For those few driers that may thermally dry high-sulfur coal in
the future, the cost of controlling S02 emissions is considered un-
reasonable. The largest thermal driers at 500 tons per hour bum
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TABLE 1
COMBUSTION PRODUCT EMISSIONS FROM
WELL-CONTROLLED THERMAL DRIERS
Pollutant Concentration, ppm
N0x
S0x
HC (as methane)
CO
40 to 70
0 to 11.2
20 to 100
< 50
L-iiii^aiuii r a it*? ,
0.39 to 0.68
0 to 0.09
0.07 to 0.35
<0.30
Coal-fired power.piant»e
lh/(Rtu Y in6)
0.70
1.20
Standards of Performance for Fossil-Fuel-Fired Steam Generators as promulgated in
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approximately 5 tons per hour coal as fuel. The accompanying
furnace would be rated at 130 million BTU/hr which is less than
the smallest power plants required to control S02 emissions under
standards of performance.
Finally the wet scrubbers used to control particulate emis-
sions from thermal driers also appear to control S02 emissions.
The two driers tested emitted S02 at 0-10 percent of the levels
expected, based on firing rate and fuel sulfur content.
For these reasons no standards for S02 or NOX were proposed.
Standards for hydrocarbons and carbon monoxide were also rejected
because the emission levels were low.
Table 2 shows a typical analysis of the heavy metals content
of particulates emitted from thermal driers. The largest well-
controlled thermal driers (500 tons/hr feed and 50 Ib/hr emissions)
would discharge less than 0.005 Ib/hr arsenic. Emissions of other
heavy metals are somewhat lower. Since most heavy metals are emitted
as particulates, a particulate standard limitation will also control
these pollutants. Hence, only standards of performance have been
recommended for particulate emissions from coal preparation plants.
Selection of Units for the Standard
Both mass and concentration units were considered for the stand-
ard. A limitation on mass (such as pounds of particulate emission
per ton of coal feed) has the advantage of being universally restric-
tive in that it precludes circumvention by the addition of dilution
-------
TABLE 2
"PACE METALS ANALYSIS OF PARTICULATE EMISSIONS FROM A COAL DRIER
Concentration, Concentration,
Element ppmwa Element ppmwa
Be
Cd
As
V
Mn
Ni
Sb
Cr
Zn
Cu
Pb
Se
B
F
Li
Ag
Sn
Fe
Sr
Na
1
«50
< 100
50
50 to 100
20 to 30
< 50
30
< 100
30
< 30
—
10
--
< 10
< 1
< 50
5000
100
300
K
Ca
Si
Mg
Bi
Co
Ge
Mo
Ti
Te
Zr
Ba
Al
Cl"
so"
4
1000 to 2000
3000
1.5%
1000
< 10
< 10
< 30
< 10
500
< 100
10
200
1.0%
40 to 118
1040 to 3920
a Parts per million by weight.
14
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air. Such a standard would require an accurate determination both
of mass emission rate and the weight of the feedstock to the pro-
cess. Also an operator could defeat a mass standard by adding
coarse coal to the drier feed, resulting in a significantly larger
process weight and little change in emissions.
A limitation based on concentration (such as 0.03 grain per
dry standard cubic foot) requires limited knowledge of coal feed
rates. Although this type of standard could conceivably be
circumvented by dilution, such action would not be an economically
viable option to the operator for the following reasons:
1. A thermal drier operates most efficiently with a maximum
temperature differential (limited only by safety considera-
tions) between the hot combustion gases and the coal bed.
Consequently dilution of the hot combustion gases with much
cooler ambient air would reduce drying efficiency and
increase fuel costs.
2. Introduction of air between the drier and the final control
device would not achieve any operating cost savings since
the horsepower required to move the greater volume of air
at lower pressure through a lower energy control device is
equivalent to that required to move the lower volume of
air at the greater pressure with the higher energy venturi
type scrubbers.
3. Introduction of air downstream of the control device is not
only specifically precluded, but such adulterations to the
typical control device would be obvious.
15
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It was concluded that concentration units, grains per dry
standard cubic foot (gr/dscf), should be used for the standards
of performance for coal preparation plants, with a suitable in-
clusion to prevent circumvention by dilution air. This conclusion
is based on the following:
1. Only precise measurement of emissions is required to
enforce a concentration standard.
2. Less precise information on feedstock or product weights
is required for a concentration standard than for a mass
standard.
3. Emission data used as a basis for development of the stand-
ards of performance were measured in concentration units.
Since process feed rates were merely estimated, data to
support a mass standard would be less reliable.
4. A mass standard based on process weight would be ineffective.
An operator could circumvent the standard by passing the
larger sizes of coal through the drier, which could increase
process weight significantly without increasing emissions.
Selection of Sampling and Analytical Methods
All tests of particulate emissions conducted under EPA contract
to provide a basis for proposing standards of performance have used
Method 5, "Determination of Particulate Emissions from Stationary
Sources," as described in Appendix A of 40 CFR Part 60. Therefore,
i
it was concluded that the proposed standards should be based on the
same method.
16
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Most control devices now in operation discharge exhaust gases
in a swirling pattern. Any flow pattern other than one parallel
to the stack wall has a detrimental effect on the accuracy of standard
measurement techniques. For this reason, it was concluded that the
standard should require new control systems for thermal driers and
air tables to discharge exhaust gases in parallel flow and to pro-
vide sufficient stack height for representative sampling according
to EPA Method 5.
Discussion of Standards Development
Early investigation (which included the preliminary results of
an industry study by EPA and discussion with local control agencies,
manufacturers of control equipment, and the industry trade association)
revealed the location of several reportedly well-controlled coal
preparation plants. Of the approximately 130 in the nation which have
thermal driers or air tables, 31 were visited to obtain information
on the emission control system. During the visits, the plants were
critically appraised to determine those which represented the best
demonstrated air pollution control technology for the industry. The
general criteria used were: (1) the opacity of plant emissions,
(2) results of previous emission tests, (-3) air pollution control
equipment and operating techniques, (4) suitability of control equip-
ment for testing, and (5) maintenance practices.
Communications with persons knowledgeable in coal preparation
indicated the major variable which contributes to particulate emissions
17
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from thermal driers is the size distribution of the feed. To
ensure results of the program were not biased optimistically, it
was decided to test installations which processed the largest per-
centage of "fines" but utilized what appeared to be the best system
of emission reduction. Consequently, a specific criterion for
selection of test sites was high fines content in the feed ,to the
drier. Representatives of the coal industry, manufacturers of thermal
driers, and vendors of control equipment indicated coal from the
Pocahontas coal region of West Virginia and Virginia is the most
friable and hence most difficult to control. As a result, all but
one of the plants which was sampled processed coal from the Pocahontas
seam. In all tests by EPA, the maximum available amount of fines was
fed to the drier.
Although not apparent during the initial visits, the mode of
flow of the exhaust gas was to become a very important consideration
in the evaluation of the results of emission tests. Figure 4 repre-
sents the general type of control system used by all plants that were
selected for testing. Exhaust gases from the primary collector pass
through a venturi-type wet scrubber which may operate at pressure
differentials of 15 to 32 inches water gauge (but which may be raised
as high as 57 inches). Water consumption was about 8 gallons per
minute per 1,000 cubic feet per minute of gas cleaned.
The exhaust gases entrain water from the scrubber which is re-
moved by a mist eliminator. Gases enter the cylindrical mist
eliminator tangentially and flow upward in spiral flow. In theory,
18
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SAMPLING
PORTS
Figure 4. Venturi scrubber-mist eliminator.
19
-------
the water is centrifugally thrown to the cylinder wall where it
flows by gravity to a drain. Mist eliminators of this design can
present two problems to accurate emission mi surement:
1. The design parameters used by at least one manufacturer
appear inadequate because significant amounts of water
exit from the top of the mist eliminator. High gas velo-
cities in the stack continue to carry water up the stack
wall until it is ejected from the top of the stack by the
turbulent gas stream. A steady "rain" of black, dust-laden
water was evident in the vicinity of such stacks. Several
of these systems had been retrofitted with a "catch-ring"
as shown in Figure 5. It is designed to capture the water
which is carried over and return it to a drain. The effi-
ciency of these catch rings appears moderate to poor.
Obviously, the contribution to total emissions of the random
emissions of mist cannot be accurately measured.
A similar collector by another manufacture (Figure 6) differs
in three obvious aspects: (1) the length-to-diameter ratio
of the mist eliminator is greater, (2) it has a taller stack,
and (3) it has a proportionately larger stack diameter which
permits lower gas velocity within the stack. The exhaust
streams from mist eliminators made by this manufacturer con-
tain little or no entrained water.
20
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CATCH
RING
DRAIN
STACK WALL
Rgure 5. Retrofitted catch ring.
-------
SAMPLING
PORTS
STRAIGHTENING
VANES
L-.L-.J
VENTURI
THROAT
Figure 6. Venturi scrubber-mist eliminator with straightening vanes.
22
-------
2. The cyclonic flow patterns common to all cylindrical mist
eliminators make measurements of particulate emissions
suspect.
Wet Cleaning Systems
Twenty-eight thermal driers were inspected. These were of
various designs, processed a variety of coals, and utilized wet
scrubbers of various designs. Of these, five fluid-bed driers
were selected for emission measurement because it is expected that
new driers will be of the fluid-bed type. EPA tested three of these
facilities, designated C, D, and E in Figure 7. All utilize a mist
eliminator with the poorer efficiency. Plant C, the only plant with
permanent straightening vanes, was tested twice. The first test
(C,) showed average particulate emissions of 0.014 gr/dscf, the second
test (C2) 0.019 gr/dscf.
Emissions from Plant D were evaluated on two separate occasions.
The first test (D-j) indicated an average emission rate of 0.017 gr/dscf
(without vanes). Two additional series of tests at a later date were
taken in quick succession in an attempt to reveal the effect of
straightening vanes. Without vanes (test D2), average emissions were
0.024 gr/dscf. With temporary straightening vanes installed as shown
in Figure 8, three samples averaged 0.044 gr/dscf (test D3). Also,
with the vanes installed, the visibility of the particulate-laden "rain"
increased notably. As might be expected, the straightening vanes appear
to nullify the centrifugal flow and the effectiveness of the catch ring.
23
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0.06
0.05
0.04
I
i
! 0.03
UJ
LLJ
3
2 0.02
0.01
ft
I I
1^1
* t
t I
0
AVERAGE
d
• EPA TEST METHOD
O OTHER TEST METHOD
b
"PLANT G! C2 DI 02 03 EI ii F G H
NO. OF RUNS'3 3 33 3 2 2 4 3 2
0
2
FIGURE 7. Particulate emissions from thermal dryer exhausts controlled by wet scrubbers.
24
-------
SAMPLING
PORTS
STRAIGHTENING
VANES
WATER
INLET
MIST
ELIMINATOR
Figure 8. Venturi scrubber-mist eliminator with straightening vanes.
25
-------
The scrubber at Plant E operated with the lowest energy con-
sumption, 21 inches of water. This plant was also sampled on two
occasions. During the test labeled E, on Figure 7, the drier was
operating normally. The surface moisture content of the product coal
was about 3 percent. However, when the test represented by point E?
was made, the surface moisture content of the product coal was about
1.2 percent, far below normal. "Overdrying" of coal is generally
acknowledged to greatly increase particulate emissions. For this
reason, data from test E~ were not considered in the selection of
the standard.
Test results shown for Plants F, G, H and I were provided by the
industry. Only the results of the test on Plant H, 0.029 gr/dscf,
were reportedly obtained using EPA methods. The methods used at the
other plants is not known. The proposed standard of 0.031 gr/dscf
is supported by measurements of emissions at all plants tested. There
are two instances where the proposed standard was exceeded. The first
occurred when flow straighteners were inserted at Plant D. This ob-
viously increased emissions because the discharge of dirty water in-
creased. (Doubtlessly the particulate in the dirty water reentrained
from the stack wall after installation of flow straighteners was
largely responsible for the difference in test results D« and D~.)
Secondly, during test Ep coal was being dried to about 1 percent sur-
face moisture, well below the 2 percent threshold at which dust emis-
5
sions become severe. The overdrying was confirmed both by moisture
analysis on the product coal and the abnormally high temperatures
recorded on the drier exit monitor.
26
-------
Vendors of control equipment have guaranteed emissions of less
than 0.030 gr/dscf. 'One vendor has guaranteed 0.020 gr/dscf, while
another is considering such a guarantee. * Based on these findings
it is the Administrator's judgment that the achievability of the pro-
posed standard of 0.03 gr/dscf for partlculate emissions from thermal
driers has been adequately demonstrated.
Dry Cleaning Systems
Of the 37 plants that operated air tables in 1972, 13 had emis-
sion control equipment. EPA representatives visited three plants.
Two, which used fabric filters for control, exhibited no visible
stack emissions and were subsequently tested. The third, which had
no air pollution control ..device, showed visible emissions of greater
than 20 percent opacity. Results of the two series of tests on the
air tables with fabric filter controls are presented in Figure 9.
Particulate loadings averaged 0.008 gr/dscf and 0.005 gr/dscf for
Plant A and B, respectively. Figure 9 also presents, as test B2,
emission data provided by the operator of Plant B. Their results
averaged 0.007 gr/dscf and ranged from 0.004 to 0.011. Based on these
findings it is the Administrator's judgment that the achievability
of an 0.018 gr/dscf particulate emission standard for pneumatic
cleaning has been adequately demonstrated.
A projected decline in the use of air tables (substantiated by
the small number of new installations during the past 2 years) dimin-
ished the requirement for extensive testing. Although it is expected
27
-------
1 0.02
0.01
3
on
14
14
0
H-H AVERAGE
O
©EPA TEST METHOD
O OTHER TEST METHOD
17
PLANT A
NO. OF RUNS 2
10
FIGURE 9. Particulate emissions from air table exhausts controlled by fabric filters.
28
-------
that few new air tables will be constructed, the standard is proposed
because they are still available from equipment vendors.
Visible Emission Data
Visible emission readings were made at well-controlled
coal preparation plants operating at or near design rates. The
sources monitored at each of two plants were:
(1) thermal drier exhaust, controlled by 35" AP venturi
scrubber,
(2) breaker and raw coal transfer exhaust, controlled by a
fabric filter,
(3) cleaned coal transfer exhaust, controlled by a fabric
filter, and
(4) cleaned coal loadout exhaust, controlled by a 6" AP wet
scrubber.
One plant showed visible emissions of 10 percent or less from
all sources monitored during a 7-hour period. A second plant ex-
perienced frequent upsets in which visible emissions from all sources
exceeded 20 percent. Duuring normal operation visible emissions
from all sources at the second plant were 10 percent opacity or less.
Visible emissions from both thermal driers exceeded 20 percent
during routine startups and shutdowns. These periods of excessive
visible emissions were 10-20 minutes for startups and 10-15 minutes
for shutdown.
29
-------
Excessive visible emissions would be expected from a startup or
shutdown; however, these periods are exempt from the standards
[40 CFR 60.11(c)].
Furthermore, visible emissions from wet scrubber exhausts are
a function of ambient atmospheric conditions. Visible emissions
on a cold, damp day are masked by uncombined water vapor, hence may
be zero while the same exhaust on a hot, dry day may exhibit emis-
«
sions of 20 percent opacity. Therefore, it is concluded that a
"cushion" should be included in the opacity limits for thermal driers
to compensate for the seasonal variations in visible emissions.
It is the policy of EPA in proposing particulate emission stand-
ards to include visible emission standards as an enforcement tool.
Since the operator of an affected facility may be penalized for viola-
tion of these visible emission standards, they are established such
that a violation of a visible emission standard would unquestionably
indicate a simultaneous violation of the particulate standard.
Thus, a 30 percent opacity limit for thermal driers during normal
operation is proposed, while for all other sources which are unaffected
by operating parameters or seasonal variations, a 20 percent opacity
limit is proposed.
Conclusions
The proposed particulate emission standards of 0.031 gr/dscf for
thermal driers and 0.018 gr/dscf for pneumatic coal-cleaning equip-
ment are supported by emission measurements by EPA on Plant C, D, and
E and Plants A and B, as presented in Figures 7 and 9, respectively.
30
-------
Proposed opacity standards of less than 30 percent for thermal driers
and less than 20 percent for air tables and all other affected
facilities are supported by visible emission observations. The
standards will require installation and proper maintenance of equip-
ment representative of the best technology wh-ich has been demonstrated
for the industry. In the Administrator's judgment, the achievability
of the proposed standards has been adequately demonstrated.
ENVIRONMENTAL IMPACT OF PROPOSED STANDARDS
Coal preparation plants generate large quantities of solid wastes
and waste water. Solid wastes include mine rock scalped from raw coal
and fine impurities from wet coal cleaning. Liquid wastes are gen-
erated by wet coal washing and scrubber discharges.
For a typical coal preparation plant processing 600 TPH raw
coal, approximately 180 TPH of solid refuse and 4500 gpm waste water
are generated. A wet scrubber used to meet the proposed thermal
drier standard would contribute 640 gpm waste water and 1.54 TPH
solids in the waste water discharge.
Since all plant waste waters are clarified and reused in plant
processing no water pollution will result. Solids in the scrubber
liquid discharge may or may not be reclaimed as product coal. If the
scrubber solids are discharged with other solid refuse the contribu-
tion is less than one percent of total wastes. With the rising price
of coal, it seems unlikely that new preparation plants would discard
the 1.54 TPH fine coal in scrubber liquids.
31
-------
In dry coal processing, all material captured by emission
controls is returned to the process. No water is used by best
emission controls. Thus no water or solid waste pollution is
generated.
Energy requirements of emission controls used to meet the pro-
posed standards for thermal driers are roughly 3 kilowatt-hours per
ton of coal dried. Based on anticipated growth of 5.6 million tons
per year of dried coal, the annual energy consumed by new thermal
drier controls would be 16.8 x 106 kilowatt-hours. Of this, one-third
or 5.6 x 10^ kilowatt-hours would be used to meet Federal standards
over existing State standards.
Since zero growth is anticipated for dry coal cleaning, no
additional energy is required to meet the proposed standard.
ECONOMIC IMPACT OF PROPOSED STANDARDS
The outlook for growth in the coal cleaning sector is clouded
by several factors. Current restrictions imposed by State Implementation
Plans on the burning of high-sulfur coal could cause dislocations in
the Eastern coal-producing areas during the next few years. The use
of air tables, one of the two prime sources of particulate pollution,
may be discontinued. Compliance with Department of Interior dust
abatement regulations promulgated under the authority of the Coal Mining
Health and Safety Act results in a high moisture content in the coal
which renders the coal unsuitable for air table processing.
Nevertheless, long-term forecasts of energy requirements indicate
a rise in cleaned coal requirements from 323 million tons in 1970 to
580 million tons in 1985. The new thermal driers required for this
32
-------
expansion plus replacement driers, which historically have run at
about 4 to 5 percent of existing capacity per year, indicate that
nine new driers per year will be required. No new or replacement
air table installations are projected.
Essentially all of the current coal cleaning operations are
subject to particulate regulations. Figures 10 through 12 show the
proposed standard of performance in relationship to existing State
regulations covering 88 to 98 percent of the coal cleaned. Air
table operations are typically controlled by a fabric filter and
this control device is capable of meeting all existing State regula-
tions as well as the proposed standard of performance of 0.018 gr/dscf.
Therefore, if a fabric filter capable of handling the entire air table
effluent is installed, it will, if adequately maintained, meet the pro-
posed standard and result in no adverse economic impact.
Emissions from thermal driers are universally controlled by wet
scrubbers. A significant explosion potential exists as hot gases come
in contact with finely divided coal. Electrostatic precipitators have
not been considered for this reason. Fabric filters are generally un-
suitable for the same reason and because the high dew point of the
gases could result in blinding the filtration surfaces. The degree
of control available from wet scrubbers is a function of the pressure
drop across the unit and thus cost is directly proportional to the
emission limits. Table 3 depicts the maximum impact of the proposed
standards of performance (0.031 gr/dscf) for driers by comparing it
to the 0.07 gr/dscf standard of a State where 49 percent of the thermally
33
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£ —
\/ \ \ \\\\\\
\ \ \ \\ 11
104
105
PROCESS WEIGHT, Ib/hr
SOURCE: STATE IMPLEMENTATION PLANS, BUREAU OF MINES
Figure 10. Proposed thermal drier regulation (0.031 gr/dscf) compared with existing State regulations
(62% of 1971 production represented) - basis: 24,000 dscf/ton.
34
-------
X
I I I I I MM
PROCESS WEIGHT, Ib/hr
SOURCE: IMPLEMENTATION PLANS
Figure 11. Proposed air table regulations (0.018 gr/dscf) compared with existing State regulations
(98% of 1971 production represented) - basis: 30.000 dscf/ton.
35
-------
o
S3
PROCESS WEIGHT, Ib/hr
THIS REGULATION WAS PROPOSED FOR UTAH IN THE FEDERAL REGISTF.r, JULY 27,1972, TO BE PROMULGATED BY EPA.
SOURCE: STATE IMPLEMENTATION PLANS, BUREAU OF MINES.
Figure 12. Proposed thermal drier regulation (0.031 gr/dscf) compared with existing State regulations
(26% of 1971 production represented) - basis: 24,000 dscf/ton.
36
-------
dried coal is produced. The State standard will require a unit
with 16 inches of water pressure drop. To meet the proposed
standard a pressure drop of 25 to 35 inches water gauge is required.
The operating costs are geared for that level. However, prudence
would dictate the purchase of equipment capable of doing better
than just meeting the current regulation. Therefore, where possible,
the equipment is sized to provide 10 more inches of water pressure
drop than that required by regulation.
Table 3 shows that the total drier investment will be increased
by about 3 percent.
Annualized operation costs including additional power, maintenance,
taxes, insurance, depreciation, and interest charges were in the
range of 6.5<£ per ton of coal cleaned for the plant sized considered.
The after-tax drop in net income, if the increase cannot be
passed on, is anticipated at less than 1 percent. However, since the
price of coal has risen $1.43/ton to $8.50/ton from 1971 to 1973,
the extra cost of 2 cents per ton representing the impact of Federal
standards over State standards should be easily passed along.
Since all States require particulate control, the impact of
standards of performance on equipment suppliers will amount to a
need to upgrade equipment rather than to increase the number of
units.
37
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TABLE 3
CONTROL COSTS FOR COAL CLEANING - WET SCRUBBING EQUIPMENT FOR THERMAL DRIERS
oo
00
Plant Size, Run of Mine
3,000,000 Tons/Year
5,000,000 Tons/Year
Drier Feed*
401 Tons/Hour
668 Tons/Hour
Drier Investment
$883,000
$1,199,000
Emission Standard
A State
Regulation
'(0.07 gr/dscf)
Proposed U.S.
Standard
(0.03 gr/dscf)
A State Proposed U.S.
Regulation Standard
(0.07 gr/dscf) (0.03 gr/dscf)
Control Investment**
Investment Increase
Required
Annual Cost
$256,000
$88,200
$284,000
2.5%
$118,200
$409,000
$142,600
$454,000
2.8%
$192,300
Cost Per Ton of Cleaned
Coal
*Based on 3480 hours/year and 46.5% feed to driers.
**Fabric filters for fugitive dust would add about $20,000 to each system and $5000 to annual costs.
-------
REFERENCES
1. "Background Information for Establishment of National Standards
of Performance for New Sources - Coal Cleaning Industry,"
Contract No. CPA 70-142, Task Order No. 7, Environmental
Engineering, Inc., and Herrick Associates, July 15, 1971.
2. Leonard, Joseph W. and Mitchell, David R., Coal Preparation. AIME,
New York, New York, 1968.
3. EPA Coal Preparation Industry Survey, conducted May-August, 1972,
Survey Form OMB No. 158-S 72008.
4. "Analysis of Final State Implementation Plans - Rules and
Regulations," Contract No. 68-02-0248, MITRE Corporation,
July 1972.
5. Private Communication, Joseph Notary, Heyl and Patterson, Inc.,
to Charles B. Sedman, Industrial Studies Branch, OAQPS, EPA,
January 17, 1973.
6. Letter, H. Soderberg, American Air Filter, Inc., to C. Sedman,
Industrial Studies Branch, Office of Air Programs, EPA,
November 2, 1972.
7. Letter, R. Dubrovsky, Research Cottrell, Inc., to J. McCarthy,
Performance Standards Branch, Office of Air Programs, August 10,
1972.
39
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TECHNICAL REPORT DATA
/flease read Instructions on the reverse before completing)
EPA-450/2-74-021a
3. RECIPIENT'S ACCESSIO(*NO.
PLE
) SUBTITLE
BACKGROUND INFORMATION FOR STANDARDS OF PERFORMANCE:
Coal Preparation Plants, Volume 1, PROPOSED STANDARDS
5 REPORT DATF
October 1974
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO
ME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, N.C. 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
2. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
rARY NOTES
This volume is the first of a series on standards of performance for coal
preparation plants. This volume presents the proposed standards and the
rationale for the degree of control selected. The volume also discusses
the analytical methods for sampling emissions and the environmental and
economic impact of the standards.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Air pollution
Pollution control
Performance standards
Coal Preparation Plants
Air pollution control
DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO, OF
20. SECURITY CLASS (Thispage/
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
40
U.S. GOVERNMENT PRINTING OFFICE) 1974 - 640-877/620 - Region 4
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ENVIRONMENTAL PROTECTION AGENCY
Technical Publications Branch
Office of Administration
Research Triangle Park. N.C. 27711
POSTAGE AND FEES PAID
ENVIRONMENTAL PROTECTION AGENCY
EPA - 335
OFFICIAL BUSINESS
AN EQUAL OPPORTUNITY EMPLOYER
Return this sheet if you do NOT wish to receive this material CD,
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