S-EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-81-146 Oct. 1981
Project Summary
Use of Coal Cleaning for
Compliance with SO2
Emission Regulations
E. H. Hall, A. W. Lemmon, Jr., G. L Robinson, F. K. Goodman, J. H. McCreery,
R. E. Thomas, and P. A. Smith
The results of an overall evaluation
of the potential role for coal cleaning
as a means of controlling S02 emis-
sions from coal-fired stationary
sources are presented in this report.
The objectives were to examine the
capabilities of coal cleaning in the light
of various existing and proposed SOz
emissions regulations to determine
the applications in which the tech-
nology would be most useful, to
identify the barriers which exist to
prevent wider application of coal
cleaning, and to describe actions
which should be taken to overcome
these barriers.
Much information about coal is
compiled as resource data, including
data on the coal reserve base and coal
cleanability. It also includes present
and projected coal production and use
by utilities and industry, as well as the
nature of coal contracts and the size
and age distribution of coal-fired
facilities.
The environmental impacts of coal
cleaning are compared with other
sulfur removal strategies such as flue
gas desulfurization (FGD) and the use
of low-sulfur coal; similarly, cost
comparisons are made between var-
ious alternatives for SO2 control. The
results of the cost analyses show,
when all costs and benefits to utilities
of using physical coal cleaning (PCC)
are properly evaluated, an economic
superiority for physical coal cleaning,
even if supplemental application of
another method, FGD, must be used
to achieve full compliance with appli-
cable New Source Performance Stan-
dards (NSPS) or State Implementation
Plan (SIP) emission limits. Compari-
sons also are made between the
quantities of coal which could be
made available through the use of
various coal cleaning processes to
meet different emission standards and
the quantities of coal currently required
by utility and industrial facilities
operating under each standard. The
results show clearly the usefulness of
coal cleaning in producing coal to
satisfy SIPs or the 1971 NSPS.
Barriers to the implementation of
coal cleaning are identified in several
areas: technical, institutional, envi-
ronmental, economic and social,
legislative and regulatory, and trans-
portation. The common theme is that
of uncertainty. Investments in coal
cleaning facilities may be deferred
because of such uncertainties as:
• Questions related to technical
details; e.g., lack of performance
data from a commercial plant
showing that clean coal can be
produced with the reduced sulfur
content predicted by experimen-
tal washability data.
• Changing environmental regula-
tions.
• Ultimate profitability of the in-
vestment.
Actions recommended to overcome
these barriers include nine technical
-------
research and development programs,
and various actions to implement one
of two policies: either to provide
growth in coal cleaning by ensuring
that coal cleaning is competitive in the
marketplace and that coal users
believe that it is worth the investment,
or to require that all high sulfur coal be
cleaned before it is burned.
This Project Summary was devel-
oped by EPA's Industrial Environ-
mental Research Laboratory. Research
Triangle Park. NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
What is the best way to control the
emission of S02 resulting from coal
combustion? The a nswer to this complex
question depends on such factors as the
characteristics of the coal being burned,
the size and type of the combustion
facility, whether the facility is existing or
being planned, the location of the
facility, and the emission regulations
the facility is required to meet.
Physical coal cleaning has been used
for many years to remove ash from coal
before combustion or coke manufacture.
Conventional coal cleaning processes
also remove part of the sulfur from the
coal, and modified coal cleaning
processes for enhancing sulfur removal
are being implemented. Thus, coal
cleaning is one way to reduce S02 emis-
sions. The usefulness of coal cleaning in
this role depends on the factors just
listed, and this study was undertaken to
evaluate the potential for coal cleaning,
in the light of these factors, and to
determine the applications in which the
technology would be most useful. A
further objective of this study has been
to identify barriers which hinder the
adoption of coal cleaning for SO2 control
and to recommend actions to overcome
these barriers.
This report includes the results of the
broad range of analyses required to
meet the objectives. For many of these
analyses summaries of the findings are
given in the body of the report with
details of the methodology and the
results given in appendices.
Conclusions and
Recommendations
The major findings of this study are
derived from an assessment of the
cleanability of U.S. coals, from an
analysis of the increase in the quantities
of compliance coals achievable through
coal cleaning, from a comparative
evaluation of the costs of various SC>2
control methods, and from an analysis
of barriers to the expanded use of coal
cleaning. Additional background in-
formation had been developed and
compiled, including: considerations of
the variability of sulfur in coal; data on
coal production, coal use, coal reserves,
coal contracts, and constraints to
increased coal production; an overview
of coal cleaning technologies; and a
comparison of the environ mental effects
of various S02 control methods. Brief
summaries of the major findings are
presented as background for the con-
clusions and recommendations.
Summary of Major Findings
Coal Cleanability
The potential for coal cleaning as an
SOz emission control technique depends
on the coal cleaning processes employed
and on the characteristics of the coal
being cleaned. To estimate the clean-
ability of the entire U.S. coal reserve
base, many coal cleaning processes
must be considered with respect to
specific coal properties. To accomplish
this, a computer model was developed
which combines three sets of coal data
and allows a variety of analyses to be
performed on the resultant data base. It
is called the Reserve Processing As-
sessment Model (RPAM).
The data base is composed of an
overlay of the reserve base of U.S. coal,
washability data for coal from sample
mines, and about 50,000 detailed
sample coal analyses. All three sets of
data were obtained from the U.S.
Bureau of Mines or Department of
Energy in the form of computer tapes.
The resulting overlay contains 36,000
coal resource records which have the
following information for each:
• Region, state, county, and bed.
• Weight in tons of both strip and
underground coal.
• Mean percent by weight of ash,
organic sulfur, and pyritic sulfur.
• Mean heat content expressed in
Btu/lb.*
• Float-sink distribution of the mined
coal for different size fractions and
media densities.
(*) Metric equivalents are given elsewhere in this'
Summary.
From this consolidated data base, the
effects of a coal cleaning process on the
reserve resources can be calculated.
The coal cleaning process specified can
be real or hypothetical, physical or
chemical processes.
Programs were written to permit
various analyses to be made on the
combined data base, permitting:
• Calculation of the quantities of coal
which could be upgraded to be in
compliance with variousfixed-limit
SO2 emission standards through
coal cleaning by various processes.
These were calculated on a regional
basis, and include consideration of
sulfur-content variability.
• Calculation of the quantities of coal
which could be produced by dif-
ferent coal cleaning processes to
meet standards which require
removal of a stated percentage of
the sulfur in the raw coal. These
were calculated by region and for
various emission-averaging times
to reflect sulfur variability.
• Calculation of quantities of coal
which could be burned in compli-
ance with various percentage-
removal standards using combined
coal cleaning and flue gas desulfuri-
zation (FGD). These were calcu-
lated as a function of the FGD <
removal efficiency required. The
results show, for example, that for
13 percent of the coal in the
Northern Appalachian Region, a
simple cleaning process consisting
of crushing to 1.5 in. top size and
separation at 1.6 specific gravity
would allow the FGD system to
operate at only 80 percent sulfur
removal efficiency,and still meet a
90 percent removal standard.
Similarly, 45 percent of the coal of
that region could be used with FGD
operating at 85 percent removal
efficiency to meet the same
standard.
• Calculation of the S02 reduction
which would be achieved if all of
the coal produced annually were
cleaned before combustion. The
cleaning process assumed was
3/8 in. top size separated at 1.3
specific gravity followed by separa-
tion of the refuse at 1.6 specific
gravity with combination of the two
float fractions. These were calcu-
lated on a state-by-state basis. The
results show that a 32.4 percent
reduction in national SOa emissions
•could be achieved, at a Btu loss in
-------
Coal Availability
Existing coal-fired facilities must
meet SC>2 emission standards prescribed
by the states in the State Implementation
Plans (SIPs).'The SIPs for SO2 vary
widely from state to state and often
within a state. Coal-fired electric utility
boilers built since 1971 must meet the
New Source Performance Standards
(NSPS) of 1.2 Ib S02/106 Btu. An
evaluation of the usefulness of coal
cleaning in providing compliance coal
must consider not only the cleaning
characteristics of coal produced in
different regions but also the amounts
of coal required by facilities under each
of the various SIP regulations. A
procedure was developed for making
such an evaluation. A computer file was
developed to store data on existing
utility and industrial energy demand in
which each facility was classified by
state, actual SIP requirement, capacity,
and fuel. The location, capacity, and fuel
data for utility boilers were obtained
from EPA's Energy Data Systems (EDS)
file, and the corresponding information
for industrial facilities was obtained
largely from the Federal Energy Admini-
stration (FEA) survey of "Major Fuel
Burning Installations" (MFBI). The SIP
regulation applicable to each facility
was assigned using a separately con-
structed matrix relating ZIP code and
SIP regulations.
A "coal use" model was developed
which relates the energy requirement
taken from the facilities file to the
quantities of raw coal in the reserve and
to the quantities of coal that could be
made available by application of various
coal cleaning processes to meet the
prescribed SCfc emission standards. The
coal quantities were obtained from the
RPAM model. The analysis was by
region, with facilities in a region using
coal produced in the same region, and
for the entire U.S. The model produced,
for each SIP range, the ratio of the total
amount of compliance coal in the
reserve, either raw or cleaned by one of
eight processes, to the current annual
demand. This ratio is, in effect, the years
of availability of compliance coal for
each SIP at the current annual rate of
consumption.
As an example of the results obtained,
four bar charts are shown in Figure 1 for
facilities in the northeastern U.S. using
coal from the Northern Appalachian
Region. In each chart the ratio of total
coal to annual demand (or years of
availability) is plotted against annual
demand. The width of each bar repre-
sents the aggregate demand of all
facilities in the region which operate
under SIPs in the range shown at the top
of the bar, while the height of the bar
represents the number of years that
compliance coal would be available if
used at the current rates. The area of
each bar represents the total quantity,
in 1015 Btu, of coal in the reserves of the
Northern Appalachian Range which can
satisfy the SIPs in the indicated range.
The horizontal dotted line shows the
years of coal availability, at the current
rates, if used without regard to sulfur
content, and the area under the dotted
line represents the total Btu's of coal in
the Northern Appalachian reserve.
The four bar charts show the results
for raw coal and for coal produced by
three cleaning processes:
(A) Physical coal cleaning using 1-
1 /2 in. coal separated at 1.6 s.g.
(specific gravity).
(B) Physical coal cleaning using 3/8-
inch coal separated at 1.6 s.g. if
this produced coal to meet the
standard; otherwise, separation
at 1.3 s.g. was used. An operating
penalty of 1 percent energy use in
the cleaning process was
assumed.
(C) Meyer's process for raw coal with
greater than 0.2 percent pyritic
sulfur, the level of pyritic sulfur is
reduced to 0.2 percent. No sulfur
reduction takes place if the raw
coal pyritic sulfur level is less
than 0.2 percent. A 5 percent
energy loss was assumed plus an
operating penalty of 2 percent
energy loss and a weight loss of
10 percent.
The charts show clearly the usefulness
of these coal cleaning processes in
producing coal to satisfy SIPs or 1971
NSPS. The chart for raw coal shows that
no coal in the region could be burned in
compliance with a SIP of 0.32 (New
Jersey, industrial, metropolitan areas),
and only limited quantities of raw coal
are sufficiently low in sulfur content
that SIPs of 0.5 to 0.8 could be met. On
the other hand, the charts for coal
cleaned by Processes A, B, and C show
progressively increasing quantities
(increases in the shaded areas) of coal in
compliance with low SIPs which can be
produced by these cleaning processes.
Results of this type were produced for
eight real or hypothetical coal cleaning
processes, for six regions, and for the
entire U.S. These results show how
valuable coal cleaning is as a means of
satisfying SIP regulations and 1971
NSPS.
Cost Comparisons
A comparative analysis was conducted
of the current technologically feasible
SO: emission control methods: naturally
occurring low-sulfur coal, FGD, PCC,
and FGD + PCC. The procedure utilized
has been (1) to compare and analyze the
results of previous studies; (2) to utilize
these results and comparisons to
develop further more nearly accurate,
reliable estimates of direct costs and
benefits; and (3) to evaluate the in-
fluence of the performance of complete
energy conversion systems on the cost
and attractiveness of the competing
control methods.
In addition to the costs associated
with each technology which is tradi-
tionally included in a cost analysis,
emphasis was placed in this work on
identifying and quantifying the benefits
of coal cleaning. In the past, these
benefits have been largely ignored in
comparative cost analyses. The benefits
attributed to burning clean coal are: (1)
transportation costs are reduced be-
cause less coal is shipped due to the
increased heating value; (2) ash disposal
costs for the utility are decreased; (3)
coal pulverizing costs are reduced; (4)
benefits paid to the mine operations
Pension and Benefit Trust Fund are
reduced because fewer tons of coal are
shipped from the mine to equal the
same heating value; and (5) power plant
maintenance costs are reduced by using
coal with lower ash and sulfur content.
Other indirect benefits to the power
plant associated with burning clean coal
result from increased boiler efficiencies,
longer plant life, and increased boiler
availability.
For an emission control system
combining physical coal cleaning and
flue gas desulfurization, it is necessary
to determine the effects of physically
cleaned coal on the FGD system. The
benefits to the FGD system result from
less flue gas to be treated and, con-
sequently units of smaller size and
capacity can be used. Therefore, there
will be reduced costs for energy, labor,
chemicals, maintenance, supplies,
overhead, working capital, sludge
disposal, and land requirements for
both the scrubber system and sludge
disposal system.
For this analysis a single-unit power
plant with a nominal capacity of 500
-------
7000
500
600
400
I 200
to
-
-
.50
:50-r
.60{
L ^^^^C
1
Range -j
,
7.20-
1.50
i
1 1 I
Raw Coal 4"
p"--*- /. 60-4. 00
'
i t J •
5.1
4
0
w
10-9.1.
r *
f
30
*
—
-
-
1000
800
600
400
200
32 -^
0
*-
-
.8
-
-.50-
.60
r
0
1.20-
1.50
t
1 1 fin —i
1 1 1
Process A
4.6
1.60-4.00
1 i 1
5.
*
"0
PW*
00-9. <
d J
*.
30
h»
-
*"
-
-
0 0.5 7.0 7.5 2.0 2.5 3.0
0 0,5 7.0 7.5 2.0 2.5 3.0
Coal Demand. 7015 Btu/yeart
03
Cb
5
^
-2
2
2
n
K
^ IUUU
OQ
05
i 500
3
•§ 600
c
fc
0 400
.32^*
200
0
-
1
h
rf
• .6
50-
60
wrw+
0
1
7.20-
1.50
I '.
I I \
Process B
7.60-4.00 4.
t * *
50
I
5.0(
9.0(
1
—
3-
3 -
-
_
—
-
-
7UUU
800
600
400
.32-*-
200
0
-
—
- .5
-
r50-
60
r
0
1
7.20-
7.50
.1
1 1 1
Process C
1.60-4.00 4.L
k «. — — -
1 t. . 1
50
if •*
1
5.0C
9.0C
f
—
-
i — B
-
_
-"•
-
—
0
0.5
7.0
7.5
2.0
/.O
7.5
2.0
2.5 3.0
2.5 3.0 0 0.5
Coal Demand, 7015 Btu/yearM
'"Northeast U S utility and industrial coal demand met by coal produced in the Northern Appalachian region.
Figure 1. Increase in the quantities of SIP-compliance coal achievable by coal cleaning (see text for definition of processes).
MW was selected. For each alternative
SOz control method, the system per-
formance, availability, and costs were
evaluated. A summary of the costs is
given in Table 1.
The results show that, when all costs
and benefits to utilities of using physical
coal cleaning are properly evaluated,
physical coal cleaning has a definite
economic superiority, even if supple-
mental application of another method,
PGD, must be used to achieve full
compliance with applicable NSPS or SIP
emission limits.
The Total Costs column of Table 1 is
interesting. First, the systems which
include coal cleaning provide the least
cost methods of producing electricity.
Comparison of the two systems not
providing sufficient control to meet
1971 NSPS, Cases 1 and 3, shows that
physical coal cleaning of the fuel
provides for an overall lower cost of
generation than does the use of raw
coal (about 2.4C/kWh versus about
2.5C/kWh). This results despite the
cleaning costs and the loss of some
4
-------
'able 1. Summary of Costs for Power Generation Using Various Control Modes
Number
Case Description
Emission Operating Power plant Costs- c/kwh
Regulations Hours per Produc- Incremental
Met Year"" Fixed Fuel tion Maintenance Fixed
FGD Costs.
C/kWh
O&M
Coal Cleaning Costs and
Savings, C/kWh Tofa/
PCC PCC/FGD Costs,
Fixed O&M Savings Savings C/kWh
1 Raw high-sulfur eastern coal. None
no FGD (baseline/
2 Raw low-sulfur western coal, NSPS(a
no FGD
3"" Cleaned high-sulfur eastern Various
coal, no FGD SIPs
4 Raw high-sulfur eastern coal, NSPS""
with FGD (4 modules + 7 spare)
(Boiler = 0.8, FGD = 0.65/
module)
5 Cleaned high-sulfur eastern NSPSM
coal, with FGD (3 modules +
1 spare) (Boiler - 0.9.
FGD = 0 75/'module)
6 Cleaned high-sulfur eastern NSPS""
coal, with FGD (3 modules +
2 sparest (Boiler - 0.9,
FGD = 0.75/module)
70O8 1446 0.840 0.148 0.093
6132 1.652 1.410 0.248 —
7884 1.285 0.898 0.158 0.015
5493 1845 0.840 0.148 0.093
— — 0.041 0.089 -0.041
0.389 0.230 — — —
2.527
3.310
2.445
3.545
7061 1.435 0.898 0.158 0.015 0.270 0.230 0.046 0.089 -0.041 -0,031 3.069
7569 1.339 0.898 0.158 0.015 0.282 0.230 0.043 0.089 -0041 -0.031 2.982
(a) Not in compliance with NSPS promulgated December 23, 7977 (36FR24876).
(b) Based on postulated availabilities.
fc) Only 1971 NSPS calling for maximum emissions of 1.2 lb/SOi/10* Btu.
(d)Either 1971 or 1979NSPS, but greater scrubber capability would be needed to meet the 1979NSPS. Differences in costs of scrubbers to achieve higher SOzremovals
have been ignored. A more rigorous treatment has been provided by Kilgroe (1979).
Btu's, because of the greater, more
efficient utilization of the generation
facility and a consequent lower fixed
charge per kWh generated.
Second, for the systems which
achieve full compliance with 1971
NSPS, the two cases which incorporate
physical coal cleaning with FGD are by
far more economical (about 3.00/kWh
for Cases 5 and 6 and about 3.5C/kWh
for Case 4 for FGD alone).
Finally, the example shown for the
use of low-sulfur western coal (Case 2)
indicates no cost benefit in comparison
with any other case except Case 4; i.e.,
FGD not in combination with physical
coal cleaning. The cost here is about
3.3c/kWh for Case 2 versus about
3.5C/kWh for Case 4. This result tends
to confirm the conclusion made by some
utilities that the use of low-sulfur
western coal to achieve compliance with
the 1971 NSPS would cost less than the
use of FGD.
In summary, the use of physical coal
cleaning with FGD is significantly more
attractive economically in the examples
presented than either FGD alone or
western low-sulfur coal. It is evident,
also, that in any case where physical
coal cleaning alone will permit com-
pliance with 1971 NSPS or with SIPs, its
use will provide the lowest cost solution.
However, in any specific case, the
comparisons must be evaluated inde-
pendently to account for site-specific
variables such as coal composition,
transportation requirements, and plant
utilization.
Barriers to Expanded
Coal Cleaning
A number of factors which might
inhibit expansion of the use of coal
cleaning were examined. The common
theme encountered is uncertainty. In-
vestments in coal cleaning facilities
may be deferred because of uncertainty
regarding technical details, emission
limits or other environmental regula-
tions, or the ultimate profitability of the
investment. The general types of
barriers and examples of each are:
(a) Technical
• Data needed to relate wash-
ability results to commercial
plant performance are lacking.
• Improved quality control tech-
niques are needed.
• Better techniques for separation
of fine pyrite need to be devel-
oped and proven.
• More extensive data on bene-
fits accruing to a boiler burning
cleaned coal need to be ob-
tained.
(b) Environmental
• Solid waste disposal requires
control of leaching, fugitive
dust emissions, and fires.
• Trace elements are concen-
trated in the refuse, a benefit
with respect to the clean coal
product, but they require care-
ful waste disposal.
• Land-use options in the im-
mediate area of the cleaning
plant are restricted.
(c) Transportation
• Increased coal use will place
stress on the transportation
system.
• Coal cleaning will help in
mitigating transport problems
because of the higher Btu
content per unit weight of
cleaned coal.
• However, accelerated use of
coal cleaning could add to the
problem in certain areas in
which cleanable coals predom-
inate. For example, traffic from
the Appalachian region to the
middle Atlantic states would be
expected to increase dispropor-
tionately as 'coal cleaning ex-
pands.
(d) Institutional
• PCC benefits may not be fully
appreciated by potential in-
vestors.
• Commercial practicality of coal
cleaning as a sulfur removal
strategy may not be viewed as
adequately demonstrated.
• Uncertainty exists regarding
the Public Utility Commission's
-------
attitude toward allowing fuel
cost pass-through if a utility
were to invest in coal cleaning
facilities.
(e) Economic and Social
• Coal cleaning does not now
qualify for tax purposes as a
pollution control investment.
• Investment in coal cleaning
may be deferred because of the
possibility that, to increase
production of indigenous high-
sulfur coals, SIPs may be made
less stringent. This would
reduce the markets for cleaned
coal.
• Capital may be difficult to raise
because of the lack of informa-
tion on commercial coal clean-
ing operations.
(f) Regulatory and Legislative
• Uncertainties exist regarding
enforcement of SIPs, averaging
periods, and variances.
• Uncertainties exist surrounding
the permanence of any SC»2
emission standard.
• Uncertainties exist regarding
air and water pollution stan-
dards for coal cleaning plants.
• Uncertainties exist concerning
legislative incentives for the
industrial use of coal.
Conclusions
Coal cleaning is an effective, efficient,
and economical SOz emission control
technique. Accelerated development
and expanded deployment of the tech-
nology must be instituted.
• Physical coal cleaning is the least-
cost method of reducing sulfur
emissions from the combustion of
coal.
• Coal cleaning, with the proper
selection of sources and users, can
produce coal which can be burned
in compliance, over a period of
almost 200 years, with SIPs and
with 1971 NSPS without additional
control.
• The quantity of compliance coal
can be increased substantially by
coal cleaning. For example, in the
eastern midwest region the art-fount
of compliance coals capable of
meeting SIP requirements in the
range of 3 to 6 Ib SO2/106 Btu can
be doubled by the use of physical
cleaning techniques.
• Coal cleaning followed by flue gas
desulfurization can be an attractive
strategy for meeting the percentage
removal requirements of the 1979
NSPS. Because credit is allowed
for sulfur removal prior to com-
bustion, cleaning would permit the
scrubber to operate at a lower,
more readily achievable, sulfur-
removal efficiency and still achieve
the required percentage sulfur
removal.
• Preliminary data indicate that coal
cleaning reduces the variability of
sulfur in the product coal. If this is
substantiated, cleaned coal would
be preferred over raw coal. Reduced
variability would allow scaling
down of FGD capacities designed
to take sulfur variability into
account in meeting a percentage
reduction.
• Cleaned coals have lower concen-
trations of many of the trace
elements because of selective
concentration in the refuse com-
ponent.
• Substantial attendant benefits of
coal cleaning include reduced
transportation costs, reduced boiler
maintenance costs, reduced ash
disposal costs, and enhanced
boiler availability. When all benefits
are quantified for a given facility,
the net cost of coal cleaning will be
less than zero in many cases.
• Many of the barriers to increased
use of coal cleaning are due to
uncertainties regarding technical
questions, the level and type of
environmental regulations (now
and in the future), and the profit-
ability of investment in coal
cleaning.
Recommendations
This study leads to two basic con-
clusions: first, that widespread use of
physical coal cleaning would benefit the
entire nation; and second, that action by
the Federal government is the only way
to remove the barriers blocking expanded
use of this method of sulfur control.
Recommendations for technical research
and development and for coal cleaning
policy are based on these conclusions.
Recommended Research
and Development
Although coal cleaning has been
employed for years for ash removal and
for Btu enhancement, its use specifically
to remove sulfur is new. Adequate ash
removal technology exists, but coal
cleaning for sulfur removal remains an
art which must be advanced by applying
and improving the present technology
establish proven plant designs for sulf
removal. The non-uniform nature
coal underlies the major technic
problems to be overcome. As co
characteristics differ, their separatk
properties differ, and so does tf
optimum approach to cleaning. In tf
technical area, EPA and/or DOE shou
initiate the following research ar
development programs.
(1) Coal Washability Data. Ongoir
experimental determinatior
directed at obtaining addition
data on coal washability must t
greatly accelerated and expande
The washability data availab
now are extremely limited i
comparison to the unteste
reserves. Additional data ar
required because results froi
one seam cannot be applied 1
another. Correlational technique
should be further explored in a
effort to minimize the exper
mental data needed for eac
seam.
(2) Equipment Performance Corre/a
tions. Correlations of performanc
for individual items of equipmer
are needed to permit optimur
design and control of cleanin
plants. Such correlations can b
obtained only by analysis c
experimental performance dat
recorded under a variety of cor
ditions with many different coal:
Much of the experimental dat
still need to be obtained.
(3) Plant Simulation Model. A com
prehensive coal cleaning plan
simulation model would perm
the optimization of plant design
and plant operations. This mode
when computerized, must b<
capable of processing input:
concerning a broad range of coa
characteristics, the range o
cleaning techniques available
the performance of individua
types of equipment when presentee
with different coals (as exempli
fied by their washability), am
costs of various plant designs.
(4) Advanced Separation Techniques.
Development of advanced sep
aration designed specifically foi
sulfur removal must be acceler-
ated—including research on fine
and ultrafine particle separatior
and on chemical cleaning tech
niques for organic sulfur removal
The goal of these development!
-------
must be maximum sulfur removal
at a specified cost or minimum
cost at a specified level of sulfur
removal.
(5) Process Control System and
Sensor Development. Systems for
the control of cleaning plant
product quality must be developed.
Sensors and control systems are
both necessary. Sensors detecting
changes in feed coal characteris-
tics and product coal quality
should provide inputs to the
control system, perhaps based on
the computer simulation model,
so that equipment control set
points would be changed. These
changes in set points would be
designed to moderate product
quality variations.
(6) Test Facilities. Commercial coal
cleaning test facilities should be
built to develop advanced separa-
tion techniques and flow circuits.
Analysis of the equipment and
circuit performance at these
plants will provide much needed
engineering and cost data.
(7) Variability of Sulfur in Coal.
Studies should be conducted to
determine the sulfur variability in
product coal as compared with the
feed coal. Using these collected
data, statistical studies must be
performed so that intelligent
selection can be made of sulfur
levels of coal to be burned in rela-
tion to the emission levels per-
mitted. Two candidate statistical
approaches, traditional and geo-
statistics, giving contrasting re-
sults, are currently available for
study.
(8) Boiler Performance Data. Existing
data must be collected and addi-
tional experimental data must be
generated on the effects of
cleaned coal combustion on boiler
performance. Only by analyzing
such data may the potential
benefits accruing from the burn-
ing of cleaned coal on boiler
availability, maintenance, capac-
ity, efficiency, etc., be evaluated.
(9) Environmental Control. Demon-
strations of acceptable practices
for solid waste disposal and for
the control of pollutants in water
effluents are needed. Few data
are available on trace element
migration and control and on
infiltration of pollutants into
groundwater. Acceptable practices
should be developed and demon-
strated in conjunction with plant
demonstrations.
Recommended Pol icy Approaches
To promote widespread use of coal
cleaning, the Federal government could
adopt one of the following approaches:
Policy A: Provide growth in the use of
coal cleaning by ensuring
that the technology is com-
petitive in the U.S. market-
place and by assuring coal
users that it is a sound
investment.
Policy B: Require that all coal be
cleaned before it is burned
anywhere in the U.S.
Policy A. Assuming a successful
outcome of the technical initiative just
outlined, the private sector will make
investment decisions on the basis of
"bottom-line" economics. In general,
institutional, legislative, and regulatory
barriers are barriers because they have
an impact on the economics. Therefore,
a policy to ensure competitiveness is
needed to promote rapid deployment of
the technology.
Initiatives designed to implement
Policy A could include:
(1) Promote Regulation Stability.
Federal and state EPA's could
remove the uncertainties regard-
ing both SOz emission regulations
and environmental regulations
pertaining to coal cleaning plants.
The private sector could then
make investment decisions based
on known costs of compliance
without fear that future changes
would cause the investment to
become unprofitable.
(2) Provide EPCA Loan Guarantees.
The Federal government could
provide loan guarantees under
Section 102 of the Energy Policy
and Conservation Act (EPCA) for
building centralized coal cleaning
facilities to be used for processing
the output of many small coal
producers.
(3) Appropriate Plant Construction
Funds and Permit Management-
Fee Plant Operation. Congress
could appropriate funds to con-
struct coal cleaning plants to be
operated by industry on a man-
agement-fee basis in a manner
similar to that used by the Recon-
struction Finance Corporation in
the building of synthetic rubber
plants during World War II. Pro-
vision could be made for the
private sector to buy the plants
once profitable commercial oper-
ation is demonstrated.
(4) Reduce Tax or Subsidize. Congress
could legislate provisions for a
lower income tax rate or for direct
subsidies based on the percent of
sulfur removed prior to the sale of
the coal.
(5) Permit Pollution Control Invest-
ments for Tax Purposes. The
Internal Revenue Service —
through Congressional interven-
tion if necessary—could reverse
their position so that coal cleaning
plants would qualify as pollution
control investments for tax pur-
poses. Arguments for revision can
be based on EPA's move to credit
precombustion sulfur removal
toward an S02 percentage re-
moval standard.
(6) Allow Unit Train Rates for Rail
Shipment. ICC regulations could
be changed to allow rail shipment
of cleaned coal at the same rates
as uncleaned coal. Permit the
shipment of less-than-unit train
lots of cleaned coal at unit train
rates.
(7) Establish Public Information Pro-
gram. EPA should create a task
force to establish a top-notch
information program to educate
utilities and potential industrial
users about the benefits of burning
cleaned coal.
Policy B. As an alternative to Policy A,
Policy B would require all coal to be
cleaned prior to combustion. Congres-
sional action would be necessary to
mandate nationwide coal cleaning, of
course. Coal cleaning as now practiced
could be used in the implementation of
this policy. However, the full benefits of
coal cleaning in reducing both SC*2
emissions and electric power gen-
eration costs will be realized only after
the recommended research and devel-
opment programs are successfully
completed and the results used to
optimize the design and operation of
coal cleaning plants.
Either policy has merit:
(1) Low Cost. Physical coal cleaning
is the least-cost method for
reducing SOZ emissions.
(2) Quick Results (No Retrofitting).
Cleaned coal could be used im-
mediately in all existing facilities.
There are essentially no "retrofit"
U. S. GOVERNMENT PRINTING OFFICE: 198I/559-092/3322
-------
problems. Thus, decreased SOz
emissions can be achieved as
soon as cleaned coal becomes
available. In contrast, the NSPS
for coal fired boilers will not
materially affect total SOz emis-
sions until & significant fraction of
existing boilers are retired and
replaced.
(3) Significantly Reduced SOi Emis-
sions. State-of-the-art (ash re-
moval) cleaning methods could
reduce uncontrolled emissions of
SOz from coal-burning facilities
by an estimated 32 percent if all
coal were cleaned. Even greater
reductions would be anticipated
as economically feasible advanced
processes capable of removing
organic sulfur are developed.
Scrubbers, operating at 85 percent
sulfur-removal efficiency, would
have to be installed on 38 percent
of the entire coal-burning capacity
to achieve an equivalent reduction
in SOz emissions.
(4) Extended Boiler Life, Etc. The use
of cleaned coal is expected to
extend boiler life, improve effi-
ciency, and increase the capacity
factor—all significant conserva-
tion, operation, and cost benefits.
Reference
Kilgroe, James D., "Combined Coal
Cleaning and FGD," Industrial Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
Research Triangle Park, North Carolina,
Presented at: Symposium on Flue Gas
Desulfurization, Las Vegas, NV, March
1979.
Metric Equivalents
EPA policy includes use of metr
units in all its documents. Although th
Summary uses nonmetric units fi
convenience, readers more familii
with the metric system are asked to u:
the equivalents below.
Nonmetric
1 Btu
1 in.
1 Ib
Metric
1055.06 J
2.54 cm
0.45 kg
£ H. Hall. A. W. Lemmon, Jr., G. L. Robinson, F. K. Goodman, J. H. McCreery,
R. E. Thomas, and P. A. Smith are with Battelle-Columbus Laboratories. 505
King Avenue, Columbus, OH 4320J.
James D. Kilgroe is the EPA Project Officer (see below).
The complete report, entitled "Use of Coal Cleaning for Compliance with S02
Emission Regulations." (Order No. PB 81-247 520; Cost: $30.50, subject to
change/ will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park. NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
PS
u s
KEtilON
?30 S i)E4*HUrttt STREET
CHICAGO 1L bU6U<4
AGENCY
------- |