&EPA
INDUSTRIAL
ENVIRONMENTAL
RESEARCH
LABORATORY
FGD
QUARTERLY
REPORT
VOL 4 NO. 2
NOVEMBER 1980
RESEARCH TRIANGLE PARK, NC 27711
IN THIS ISSUE
This issue of the FGD Quarterly Report summarizes results
from several ongoing and completed studies of flue gas desulfuri-
zation (FGD). Topics include economic and energy evaluations of
established and emerging FGD processes and a major technology
assessment of waste and water management for conventional
coal combustion. Also discussed are the results from EPA's dual
alkali demonstration acceptance test at a full-scale utility boiler.
Several additional FGD-related papers and reports are now
available. Two reports have been prepared as part of EPA's
Energy/Environment R & D series: one gives an overview of SO,
control in Japan, and the other evaluates sulfur emission control
technology and waste management. The recent annual meeting
of the Air Pollution Control Association (APCA) also featured
several presentations on FGD; paper titles and ordering informa-
tion are available on page 5. The "FGD Reports and Abstracts"
section presents abstracts from 10 additional EPA-sponsored
studies. Please note the new procedure for ordering EPA/ORD
reports; they may only be obtained from the two sources listed.
The next issue of the FGD Quarterly Report will include a
special supplement describing highlights of the Sixth FGD
Symposium, held October 28-31 in Houston, Texas. Major topics
of the symposium were the impacts of recent regulations, utility
and industrial applications, byproduct disposal/utilization, and
dry scrubbing.
The FGD Quarterly Report summarizes recent developments
in EPA-sponsored and -conducted activities in FGD. It is
distributed by EPA's Industrial Environmental Research
Laboratory at Research Triangle Park, NC (IERL-RTP), without
charge, to persons interested in FGD. Please note that a return
mailer subscription renewal notice is included with this issue. The
mailer must be returned if you wish to continue receiving this
report, even ij this is the first issue you have received. The mailer
is preaddressed. Simply tear it out, check the proper box, affix a
stamp, and drop it in the mail.
STUDY COMPARES ECONOMICS AND ENERGY DEMANDS
OF THREE FGD PROCESSES
Under EPA sponsorship, the Tennessee Valley Authority
(TVA) recently completed an economic and ground-to-ground
energy evaluation of three FGD processes: limestone slurry, lime
slurry, and magnesia FGD. The TVA/EPA study (EPA-600/7-80-
001) reports that, although the capital investments and annual
revenue requirements for all three processes have increased sub-
stantially since 1975, their relative ranking remains the same. In
order of increasing capital investment, the base-case ranking is
(1) lime, (2) limestone, (3) lime with onsite calcination, and (4)
magnesia. For base-case conditions the ranking of increasing
annual revenue requirements is (1) limestone, (2) lime, (3) lime
with onsite calcination, and (4) magnesia.
Process- and Site-Specific Factors Affect
Economic and Energy Needs
The range of annual revenue requirements is significantly
narrower than the range of capital investments. The difference in
base-case revenue requirements between the limestone and
magnesia processes is less than 26%, while the base-case capital
investment for the magnesia process is more than 45% greater
than that for lime FGD. The annual revenue requirements for the
magnesia process include a credit for byproduct sulfuric acid
sales that reduces the gross revenue requirements by about 13%.
The great difference in capital investment costs is due primarily
to the requirements for slurry processing in magnesia FGD. The
costs of the additional equipment required are not fully offset by
elimination of the ponding costs.
The study also reports ground-to-ground energy requirements
for each process. These consist not only of the FGD energy
requirements but also the energy for production of the raw
materials, disposal of wastes, and an energy credit for the sulfuric
acid produced. The assessment represents, in a sense, the energy
removed from a hypothetical energy reservoir because of the
operation of the FGD systems. Credit is given for the sulfuric acid
because it replaces acid that would be produced from sulfur, and
thus the energy that would have been consumed in mining and
transporting the sulfur and producing the acid.
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FGD QUARTERLY REPORT
NOVEMBER 1980
The ground-to-ground energy comparison shows considerably
different relationships than comparison of FGD energy require-
ments alone. The FGD energy requirements of the magnesia
process (typical of regeneration processes) are about twice those
of the limestone and lime processes. The absorbent energy
requirements are low for the magnesia process because only
makeup magnesia is used. In contrast, the lime process, which
has the lowest FGD energy requirements, has much higher
energy requirements when the energy is' included for calcining
lime. With the byproduct credit included, the magnesia process is
not appreciably more energy intensive than the lime process.
The study also addresses some of the many site-specific
variables that can affect economic and energy requirements.
Power plant size and coal sulfur content have large effects on
total cost, although unit costs (in terms of sulfur removed)
decrease significantly as power plant size increases. Power plant
remaining life affects the waste-producing processes because
pond requirements decrease with age. Increased removal effi-
ciency (from 79% to 90% for 3.5% sulfur coal) has relatively
little impact on costs.
Lime and limestone FGD are the most highly developed and
utilized systems in the United States. The magnesia process,
however, is relatively undeveloped. It requires additional develop-
ment and demonstration before long-term reliability can be deter-
mined.
Additional Studies Evaluate FGD
This report is one in a series of TV A/EPA economic and
conceptual design studies of FGD systems. These evaluations are
based on certain design and economic premises established to
permit comparisons between different systems. Both the
evaluations and the premises must be periodically updated and
refined to reflect changing FGD technology.
Two previous studies (EPA-R2-73-244 and EPA-600/2-75-
006) have investigated the limestone, lime, and magnesia scrub-
bing processes. Since these earlier reports, technical and
operating information on these systems has greatly increased.
Definitive SO* Control Process Evaluations: Limestone, Lime,
and Magnesia FGD Processes (EPA-600/7-80-001) incorporates
recent technological developments and extends the earlier design
and economic evaluations of these processes. TVA and EPA have
also recently published a comparison of limestone, dual alkali,
and citrate FGD processes (EPA-600/7-79-177. see the FGD
Quarterly Report, Volume 3; Number 4). A third study of recently
developed recovery FGD processes is underway.
Additional information is available from W. E. O'Brien of
TVA's Office of Power; Energy, Demonstration, and Operations;
501 CEB; Muscle Shoals, Alabama 35660. (See also "FGD
Reports and Abstracts" in this issue.)
ECONOMIC ANALYSIS FAVORS DRY FGD
A preliminary economic analysis of generic lime spray dryer
FGD and wet limestone FGD indicates lower capital investment
costs and annual revenue requirements for the dry process. The
TVA study, performed under an interagency agreement with EPA,
also includes sensitivity analyses of raw material costs and
stoichiometries on the annual revenue requirements. Preliminary
Economic Analysis of a Lime Spray Dryer FGD System (EPA-
600/7-80-050) evaluated both processes for a new 500-MW
power plant burning western coal and meeting the current New
Source Performance Standards (NSPS) of 70% SO, removal and
13 ng/J (0.03 lb/10* Btu) particulate emission. The generic lime
spray dryer process used a baghouse for particulate collection,
while the wet limestone slurry process had an electrostatic
precipitator (ESP) for particulate control.
The base-case comparison of capital investments and annual
revenue requirements is shown below.
Generic Lime
Spray Dryer
Process
Limestone
Slurry
Process
Capital Investment (1982 $)
10* $
$/kW
66.2
132.3
93.2
186.4
Total First-Year Revenue Requirements (1984 $)
10'$
mills/kWh
17.04
6.20
23.50
8.55
Levelized Annual Revenue Requirements (1984 $)
10'$
mills/kWh
23.52
8.55
32.19
11.71
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FGD QUARTERLY REPORT
NOVEMBER 1980
This comparison indicates that, for the assumed design and
economic premises, the generic lime spray dryer process has a
•significant economic advantage over a conventional limestone
slurry process.
The dry process maintains its economic advantage at all
ranges of raw material costs and raw material stoichiometries
studied. In addition, waste disposal for the wet process, even with
fixation and landfill, is more expensive than for the generic lime
spray dryer process.
Dry FGD technology is receiving much attention because of
its potentially significant technical advantages over conventional
wet FGD: process design for dry FGD is relatively simple, stack
gas reheat may be substantially reduced or eliminated, and the
product is a dry waste rather than a wet material. A major
disadvantage of dry scrubbing, however, is that it requires an
expensive lime or soda ash absorbent. Thus in order for spray
dryer systems to be economically competitive with wet limestone
systems, the raw material cost penalty for using lime or soda ash
must be offset by savings in capital charges and maintenance
costs. For this reason the first commercial utility applications of
dry FGD are on boilers firing lignite and subbituminous western
coals. Both coals are low in sulfur, thereby minimizing the
amount of expensive alkali raw material needed for FGD. These
fuels also produce a highly alkaline ash which can be recycled
through the spray dryer to further reduce makeup raw material
requirements.
The TVA study recommends a definitive economic analysis of
the generic lime spray dryer process. This would increase the
accuracy of the base-case capital investment and annual revenue
requirements. In addition, several case variations (such as power
unit size, coal sulfur content, and SO, removal efficiency) could
be evaluated.
For additional information, contact the IERL-RTP Project
Officer. T. G. Brna, (919) 541-2683 or (FTS) 629-2683. See also
"FGD Reports and Abstracts" in this issue.
TECHNOLOGY ASSESSMENT SERIES NOW AVAILABLE
A 5-volume 1100-page assessment report is the first in a series to
evaluate the technology for controlling pollution from conven-
tional coal-fired combustion sources. The EPA study. Waste and
Water Management for Conventional Combustion: Assessment
Report—1979, is an extensive review of waste characterization
and R, D & D studies sponsored by EPA, the Electric Power
Research Institute (EPRI), and others. It covers power plant
water management as well as disposal and utilization of flue gas
cleaning (FGC) wastes. (FGC wastes are coal ash and FGD
wastes.) Some of the major conclusions of the assessment report
are summarized in the following paragraphs.
needed to develop regulations and Resource Conservation and
Recovery Act (RCRA)-related guidelines. Many of the chemical,
physical, and engineering properties of FGC wastes have been
characterized. Disposal options have been increased by such
practices as dewatering and stabilization of FGC wastes. Several
of these options have been assessed for potential environmental
effects; however, full-scale disposal operations require additional
study. The economics of FGC waste disposal must also be further
examined; specific areas include forced oxidation to gypsum.
improved FGC dewatering equipment, codisposal of ash and FGD
wastes, and stabilization practices.
Overall Power Plant Water Management
Much progress has been made in characterizing all major
wastewater power plant streams. Studies of overall water
management have shown that, in many cases, more efficient
water recycle and reuse are economically feasible. Treatment
systems to maximize water reuse are being evaluated by EPA and
by privately funded studies. Improved evaporative systems have
already resulted from these efforts. Other studies are underway to
examine the use of effluent treatment for removing priority
pollutants listed under the Clean Water Act of 1977.
FGC Waste Disposal
Substantial data on FGC waste characterization and disposal
are available and provide a portion of the technical baseline
FGC Waste Utilization
Increased utilization of FGC wastes is technically possible
but may be discouraged by regulatory and institutional con-
straints. Coal ash is already used as structural fill, in building
and paving materials, and in other construction and agricultural
applications. FGD byproducts can be marketed as gypsum (for
wallboard manufacture and cement production), sulfur, or sulfuric
acid. FGD wastes can also be used to construct artificial reefs
and control mine subsidence.
For more information on the assessment report (EPA-600/7-
80-012a, b, c, d, and e), see 'FGD Reports and Abstracts" in this
issue. Detailed questions should be directed to the EPA/IERL-
RTP Project Officer, Julian W. Jones. (919) 541-2489 or (FTS)
629-2489.
LOUISVILLE GAS AND ELECTRIC DUAL ALKALI
DEMONSTRATION ACCEPTANCE TEST
An acceptance test has been successfully concluded on EPA's
utility full-scale dual alkali demonstration system at Louisville
Gas and Electric's (LG&E's) 280 MW Cane Run No. 6 boiler. The
12-day test, conducted between July 17 and July 28. 1980.
measured the performance of the FGD demonstration unit with
respect to guarantees stated in the contract between EPA and
LG&E. Preliminary results indicate that the test was highly
successful, as shown below:
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FGD QUARTERLY REPORT
NOVEMBER 1980
Parameter
Test
Result
Guarantee
Requirement
Unit of
Measure
SO, Emission
150
(94.2% removal)
200 max.
ppm
Lime Consumption 1.04
Soda Ash Makeup 0.042
Power Consumption 1.14
1.05 max.
0.045 max.
1.2 max.
Moles CaO/mole SO, removed
Moles Na,CO,/mole SO, removed
% power generated by the unit
Waste Solids Properties 52
55 min.
% insoluble solids in waste
Paniculate Matter
88:0.1
No net addition of participate matter by % removal; based on particulate
the FGD system to the ESP outlet gas emissions measured in lb/10' Btu heat
input
System performance exceeded all guarantee requirements
excepting waste solids properties which measured about 6%
lower than the guarantee requirement. However, the contract
permits a 30% variation on this guarantee with the expectation
that process improvements, during the demonstration year to
follow, will raise the percentage above the minimum guarantee
level. Furthermore, the waste produced during the acceptance
test was considered to be of high quality, since it could be readily
fixed in LG&E's IUCS waste stabilization process.
During the 4-month period preceding the acceptance test
(March-June 1980). unit dependability was excellent (99.6%
availability); total system utilization averaged 81.7%.
Detailed questions should be directed to EPA/IERL-RTP
Project Officer Norman Kaplan, (919) 541-2556 or (FTS) 629-
2556.
INTERAGENCY DECISION SERIES FEATURES FGD
Two publications are now available which consider various
aspects of FGD. One gives an overview of SO, control in Japan,
including the observations and findings of the U.S. Interagency
Task Force which visited 11 FGD plants in Japan. Sulfur
emission control technology and waste management is the topic
of the second report, which assesses control technologies in
addition to FGD. Both reports were prepared as part of the
Energy/Environment R & D series, which presents the key issues
and findings of the Interagency Energy/Environment Research
and Development Program.
Success of FGD in Japan
Sulfur Oxides Control In Japan (EPA-600/9-79-043) con-
cludes that Japanese FGD technology is successful in both utility
and industrial applications. Scrubber installations on coal-fired
power plants routinely attain SO, removal efficiencies in excess of
90% and operational reliabilities of over 96%. Installations on
oil-fired and industrial units achieve similar efficiencies and
reliabilities.
Although Japan and the U. S. have emerged as world
leaders in developing and applying FGD technology, Japan has
generally moved faster than the U. S. because of its more serious
air pollution problems. The report discusses the technical, admin-
istrative, and government factors which must be considered when
making this comparison.
Among the FGD processes used in Japan are:
• The lime/limestone process producing usable gypsum
(45% of total FGD plant capacity).
• The indirect lime/limestone process—dual alkali type
(15%).
• Regenerate processes producing sulfuric acid, elemental
sulfur, and ammonium sulfate as byproducts (13%).
• Sodium scrubbing to yield soditfn sulfite or sulfate (27%).
The sodium sulfite is used by paper mills; it is also oxidized
to sulfate for use in the glass industry or discharged in
treated wastewater.
The report discusses in detail four Japanese plants similar to
U. S. utility scrubber installations. They are all coal-fired. Three
are utility applications using the limestone process and producing
gypsum. The fourth is an industrial boiler equipped with a lime
throwaway FGD system. Process descriptions and design/per-
formance data are presented for each plant.
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FGO QUARTERLY REPORT
NOVEMBER 1980
FGD Most Common Approach to SO2
Emission Control
The second report addresses the environmental consequences
of SOt pollution and some of the control technologies that can be
applied to alleviate these problems. Sulfur Emission: Control
Technology and Waste Management (EPA-600/9-79-019) con-
cludes that FGD is the only commercially available control tech-
nology that can be used to reduce SO, emissions to comply with
the Clean Air Act. Because FGD is an "add-on" or post-
combustion type of system, it can be retrofitted with minimum
modification to existing boilers. Over the next 5 years or so, the
only other available options capable of some degree of SO,
control are (1) the use of low-sulfur coal and (2) physical coal
cleaning.
About 90% of the FGD systems currently operational, under
construction, or planned are lime or limestone scrubbers. Other
FGD systems important for near-term (through 1985) SO,
control include dual alkali scrubbing, magnesium oxide FGD, the
Wellman-Lord process, and citrate adsorption. The report also
discusses fluidized-bed combustion (FBC) as an emerging tech-
nology with the potential for clean combustion.
Effective management of FGD wastes must consider the
relevant state and federal regulations, the various disposal and
treatment alternatives, possibilities for commercial utilization of
FGD wastes, and economics. The report discusses these aspects
of waste management.
Copies of both reports are available by contacting:
ORD Publications
Center for Environmental Research Information
USEPA
26 W. St. Claire St.
Cincinnati. OH 45268
The reports are also available through the National Technical
Information Service, 5285 Port Royal Road, Springfield, Virginia
22161. (The NTIS ordering number of the first report is PB-80-
181159. An ordering number has not been assigned for the
second.)
FGD PAPERS AVAILABLE FROM APCA MEETING
FGD was the topic of several technical papers presented at
the 73rd annual meeting and exhibition of the Air Pollution
Control Association (APCA), June 25-27 in Montreal. The annual
APCA meeting, the largest of its kind, is the only exhibition in
North America that concerns air pollution control exclusively.
This year it included several technical tours, exhibits, and poster
sessions in addition to the formal presentations.
The FGD-related papers addressed such current concerns as
status of the technology, waste disposal, industrial applications,
and regulatory implications. Specific titles, authors, and paper
numbers were:
• Sulfur Gas Emissions from Stored Flue Gas Desulfurization
Sludges, D. F. Adams and S. O. Harwell, University of
Idaho, Moscow, ID (Paper No. 80-5.2).
• An Evaluation of FGD Systems for Thermally Enhanced
Oil Recovery Operations in California, A. N. Patkar and
S. P. Kothari, PEDCo Environmental, Inc., Cincinnati, OH
(Paper No. 80-13.3).
• Status of Pollution Control Technologies for Industrial
Boilers, D. G. Streets and I. J. Weisenberg. Pacific En-
vironmental Services, Santa Monica, CA (Paper No. 80-
14.4).
• Coke Oven Gas Desulfurization by the Vacuum Carbonate
Process, R. G. Phelps, Inland Steel Company, (Paper No.
80-17.2a).
• Coke Oven Gas Desulfurization by the Carl Still Process,
R. E. Knight, Wheeling-Pittsburgh Steel Corporation,
Follansbee, WV (Paper No. 80-17.26).
• Removal of Hydrogen Sulfidefrom Coke Oven Gas by the
Stretford Process, J. E. Ludberg, Dominion Foundries and
Steel. Limited, Hamilton, Ontario (Paper No. 80-172C).
• Operation and Maintenance of Air Pollution Control in
Industry, C. A. Sellers, William T. Lorenz & Co., Boston
MA (Paper No. 80-28.4).
• Future Use of Air Pollution Control Equipment on In-
dustrial Boilers, M. Ardell, The Mcllvaine Company,
Northbrook. IL (Paper No. 80-30.2).
Reprints of these papers are available at $3.50 per copy ($2.50
for members) from APCA. Payment must accompany order. The
address is:
Air Pollution Control Association
P. O. Box 2861
Pittsburgh, PA 15230
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FGD QUARTERLY REPORT
NOVEMBER 1980
FGD REPORTS AND ABSTRACTS
This section of the FGD Quarterly Report contains abstracts
of recently completed reports relating to flue gas desulfurization.
Each listing includes date of the report. National Technical In-
formation Service (NTIS) accession number, and other identifying
numbers when available.
Requests for EPA reports should be directed to:
U. S. Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, Ohio 45268
(513) 684-7562
Each report with an NTIS number can also be ordered from
NTIS. The cost of paper copies varies by page count ($5.00
minimum); microfiche copies are $3.50. Payment must accom-
pany order. The address is:
National Technical Information Service
U. S. Department of Commerce
5285 Port Royal Road
Springfield, Virginia 22161
Definitive SOX Control Process Evaluations:
Limestone, Lime, and Magnesia FGD Processes
K. D. Anderson, J. W. Barrier, W. E. O'Brien, and S. V.
Tomlinson, Tennessee Valley Authority,. Muscle Shoals,
Alabama. January 1980. EPA-600 77-80-001. (NTIS No. PB-80-
196-314.) EPA Project Officer: M. Maxwell, 1ERL-RTP.
The report gives economic and ground-to-ground energy
evaluations of limestone slurry, lime slurry, and magnesia
(producing sulfuric acid) flue gas desulfurization (FGD) processes.
The lime slurry process, using purchased lime and lime calcined
onsite, remains lower in capital investment ($90/kW for the base-
case 500-MW power plant burning 3.5% sulfur coal) than the
limestone slurry process ($98/kW). The limestone slurry process
remains lower in annual revenue requirements (4.02 mills/kWh)
than the lime slurry process (4.25 mills/kWh). The magnesia
process is about one-third higher in capital investment
($132/kW) and one-fourth higher in annual revenue requirements
(5.05 mills/kWh including credit for acid sales) than the
limestone slurry process, because of absorbent-recovery and acid-
producing complexities. The lime slurry process using purchased
lime is more economical than the limestone slurry process at low
absorbent consumption rates (below about 200 MW or 2% sulfur
coal). Onsite lime calcination becomes economical compared to
purchased lime for larger power plants and higher coal sulfur
levels (about 1000 MW with 3.5% sulfur coal. 750 MW with 5%
sulfur coal). The limestone slurry process has the lowest overall
(raw material, FGD, and disposal) energy requirements (26% less
than lime and 30% less than magnesia).
EPA Utility FGD Survey: October-December 1979
M. Smith. M. Melia, and N. Gregory, PEDCo Environmental,
Inc.. Cincinnati. Ohio. January 1980. EPA-600/7-80-029a. (NTIS
No. PB-80-176-811.) EPA Project Officer: N. Kaplan, IERL-RTP.
problems and solutions associated with the boilers and FGD
systems. Process flow diagrams and FGD system economic data
are appended to the report.
EPA Utility FGD Survey: April-June 1980
M. Smith, M. Melia, and N. Gregory. PEDCo Environmental,
Inc.. Cincinnati, Ohio, July 1980. EPA-600/7-80-029c. (NTIS
No. Unavailable.) EPA Project Officer: N. Kaplan, IERL-RTP.
The report is the second of three supplements updating the
October-December 1979 report (EPA-600/7-80-029a) and should
be used in conjunction with it. The report, generated by a
computerized data base system, presents a survey of operational
and planned domestic utility flue gas desulfurization (FGD)
systems, operational domestic particle scrubbers, and Japanese
coal-fired utility boiler FGD installations. It summarizes in-
formation contributed by the utility industry, process suppliers,
regulatory agencies, and consulting engineering firms. Domestic
FGD systems are tabulated alphabetically by development status
(operational, under construction, or in planning stages), utility
company, process supplier, process, and waste disposal practice.
It presents data on boiler design, FGD system design, fuel
characteristics, and actual performance. It includes unit by unit
dependability parameters and discusses problems and solutions
associated with the boilers and FGD systems. Process flow
diagrams and FGD system economic data are appended.
Lime FGD Systems Data Book
T. C. Ponder, Jr.. J. S. Hartman. H. M. Drake, R. P. Kleir, J. S.
Master. A. N. Patkar. R. D. Terns, and J. D. Turtle. PEDCo
Environmental. Inc.. Cincinnati. Ohio, April 1979. EPA-600/8-
79-009. (NTIS No. PB-80-188-824.) Project Officers: W. D.
Peters, EPA/IERL-RTP, and T. A. Morasky, Electric Power
Research Institute.
The report is the first full compilation (not a supplement)
since the December 1978-January 1979 report. Because the next
three reports are to be supplements, this issue should be retained
for reference throughout the year. The report, which is generated
by a computerized data base system, presents a survey of utility
flue gas desulfurization (FGD) systems in the U. S. and Japan. It
summarizes information contributed by the utility industry.
process suppliers, regulatory agencies, and consulting
engineering firms. Systems are tabulated alphabetically by
development status (operational, under construction, or in
planning stages), utility company, process supplier, process, and
waste disposal practice. It presents data on boiler design. FGD
system design, fuel characteristics, and actual performance. It
includes unit by unit dependability parameters and discusses
The Data Book is intended to aid engineers in understanding
the process design features that are uniqoV to lime flue gas desul-
furization (FGD) systems. It is intended to supplement, not
replace, basic information on engineering design. It is addressed
to engineers who must design, evaluate, or operate lime FGD
systems. The information may also be useful to persons who are
familiar with utility operation, but unfamiliar with chemical
operation. The Data Book covers the entire process of lime-based
FGD. The gas-side battery limits extend from the discharge of
the steam generator to the discharge of the stacks. The ab-
sorbent-side battery limits extend from receipt of the lime to
sludge discharge to the final sludge disposal site.
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FGD QUARTERLY REPORT
NOVEMBER 1980
Preliminary Economic Analysis of a Lime Spray
Dryer FGD System
T. A. Burnett and W. E. O'Brien, Tennessee Valley Authority,
Muscle Shoals, Alabama. March 1980. EPA-600/7-80-050.
(NTIS No. PB-80-190-051.) EPA Project Officer: T. G. Brna,
1ERL-RTP.
The report gives results of a preliminary economic analysis
of two FGD processes (one dry and one wet) for a new 500-MW
power plant burning Western coal having 0.7 percent sulfur, 9.7
percent ash, a heating value of 9700 Btu/lb, and meeting current
new source performance standards (70 percent SO, removal and
0.03 Ib/MBtu particulate emission). The generic lime spray-dryer
process used a baghouse for particulate collection, while the wet
limestone slurry process had an electrostatic precipitator (ESP)
for particulate control. (In addition to the coal noted, the final
report will include an economic evaluation for both low- and
high-sulfur Eastern coals.) The analysis shows capital investment
costs of $132/kW for the lime process for SO, and particulate
removal, and $186/kW for the limestone process. First year and
levelized annual revenue requirements are 6.20 and 8.55
mills/kW, respectively, for the lime process; and 8.55 and 11.71
mills/kW, respectively, for the limestone process. Sensitivity
analyses indicate that: (1) delivered raw material costs do not
significantly affect the annual revenue requirements for either
process; (2) annual revenue requirements for the spray dryer are
insensitive to the raw material stoichiometry; and (3) waste
disposal for the wet process, even with fixation, is more expensive
than for the dry process.
Waste and Water Management for Conventional
Coal Combustion Assessment Report—1979,
Volume I. Executive Summary
C. J. Santhanam, R. R. Lunt, C. B. Cooper, D. E. Kleinschmidt,
I. Bodek. and W. A. Tucker (ADL) and C. R. Ullrich (U. of Louis-
ville), Arthur D. Little, Inc.. Cambridge, Massachusetts, January
1980. EPA-600/7-80-012a. (NTIS No. PB-80-158-884.) EPA
Project Officer: J. W. Jones, 1ERL-RTP.
The report is an executive summary, the first of five volumes
giving a detailed assessment of the state-of-the-art of water and
waste management technology for conventional combustion of
coal. Various R & D programs sponsored by EPA and private
industry have achieved significant results in many areas. Sub-
stantial progress has been made in characterizing major waste-
water streams and in determining physical, chemical, and
engineering properties of flue gas cleaning (FGC) wastes. Overall
water management studies have shown that more efficient water
recycle/reuse can be achieved, and can serve as models for water
management plans in new facilities. Generation of FGC wastes is
expected to increase dramatically. Utilization of FGC wastes is
also expected to grow, but much more slowly. Major FGC waste
disposal methods are ponding, disposal in managed fills, and
mine disposal. Progress in dewatering and stabilization processes
is expected to increase the relative attractiveness and viabilitiy of
the latter two methods. Potential environmental impacts are
primarily contamination of surface water and groundwater, and
land degradation (physical instability, large land requirements);
actual impacts are site- and system-specific. Applying appropriate
control technology can mitigate adverse impacts. Disposal costs
are $9-15 per dry ton of FGC wastes.
C. J. Santhanam, R. R. Lunt, C. B. Cooper, D. E. Kleinschmidt,
I. Bodek, and W. A. Tucker (ADL), and C. R. Ullrich (U. of
Louisville), Arthur D. Little, Inc., Cambridge, Massachusetts,
March 1980. EPA-600/7-80-012b. (NTIS No. PB-80-185-564.)
EPA Project Officer: J. W. Jones, 1ERL-RTP.
The second volume in the five-volume report describes water
management for conventional combustion sources and assesses
the current status of various studies and programs in water
management and trends in water recycle/reuse. A coal-fired
boiler produces both chemical and thermal pollution; this report
focuses on the former. Major use points for water and hence
generation points for effluents are of two types: continuous
(condenser cooling, steam generation, water treatment, ash
handling, FGD, and miscellaneous) and intermittent (mainte-
nance, cleaning, and drainage). The multiplicity of uses of water
in a power plant and the varying requirements of water quality in
those uses present major opportunities for water conservation and
pollution control through wastewater management, equalization,
and treatment of appropriate waste streams. While technology
exists for zero discharge of water, economics often preclude
recycle/reuse beyond a certain point. Water management studies
completed by EPA and industry can serve as models for new
facilities. Treatment systems to maximize water reuse are being
studied by the EPA and improved evaporators appear promising.
Effluent treatment to remove priority pollutants is also under
study. Important data gaps concern environmental impacts in
particular due to priority toxics in effluents due to four
operations—ash disposal, chlorination of cooling water, boiler
tube cleaning, and chemical additives in various systems.
Waste and Water Management for Conventional
Coal Combustion Assessment Report—1979,
Volume II. Water Management
Waste and Water Management for Conventional
Coal Combustion Assessment Report—1979,
Volume III. Generation and Characterization of FGC
Wastes
C. J. Santhanam, R. R. Lunt. C. B. Cooper, D. E. Kleinschmidt,
I. Bodek. and W. A. Tucker (ADL) and C. R. Ullrich (U. of Louis-
ville). Arthur D. Little, Inc., Cambridge, Massachusetts, March
1980. EPA-600/7-80-012c. (NTIS No. PB-80-222-489.) EPA
Project Officer: J. W. Jones. IERL-RTP.
The third volume of the five-volume report focuses on trends
in generation of coal ash and FGD wastes (together comprising
FGC wastes) and the characteristics of these wastes. With in-
creasing utilization of coal, the generation of FGC wastes is
expected to increase dramatically to about 115 million tons of
coal ash and 38 million tons of FGD wastes by the year 2000.
Most of these wastes will be disposed of on land. Data on the
chemical characteristics of fly ash. bottom ash, and both treated
and untreated FGD wastes in this report include data on principal
components, composition ranges for trace components, and
leaching behavior. Based on the characteristics of FGD wastes, a
categorization of these wastes is also presented. On-going
programs on chemical characterization are assessed. The funda-
mental physical properties of FGC wastes are density, size, and
crystal morphology. The critical physical and engineering
properties are those relating to handling characteristics, place-
ment and filling characteristics, long-term stability, and pollutant
mobility. The report includes information on index properties,
consistency-water retention, viscosity vs. water content, com-
paction/compression behavior, dewatering characteristics,
strength parameters, permeability, and weathering charac-
teristics. Further efforts in this area are recommended. Based on
the assessment of ongoing characterization programs, several
research needs are indicated; key need is characterization data
from full-scale FGC waste'disposal sites.
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FGD QUARTERLY REPORT
NOVEMBER 1980
Waste and Water Management for Conventional
Coal Combustion Assessment Report—1979,
Volume IV. Utilization of FGC Wastes
C. J. Santhanam, R. R. Lunt, C. B. Cooper, D. E. Kleinschmldt,
I. Bodek. and W. A. Tucker (AOL) and C. R. Ullrich (U. of Louis-
ville), Arthur D. Little, Inc., Cambridge, Massachusetts, March
1980. EPA-600/7-80-012d. (NTIS No. PB-80-184-765.) EPA
Project Officer: J. W. Jones. IERL-RTP.
Waste and Water Management for Conventional
Coal Combustion Assessment Report—1979,
Volume V. Disposal of FGC Wastes
C. J. Santhanam, R. R. Lunt, C. B. Cooper, D. E. Klelnschmldt,
I. Bodek. and W. A. Tucker (ADL) and C. R. Ullrich (U. of Louis-
ville), Arthur D. Little, Inc., Cambridge, Massachusetts. March
1980. EPA-600/7-80-012e. (NTIS No. PB-80-185-572). EPA
Project Officer: J. W. Jones, IERL-RTP.
The fourth volume of the five-volume report focuses on
utilization of coal ash and FGD wastes. With increasing
utilization of coal, generation of these wastes is expected to grow
dramatically. Utilization is expected to grow but at a slower rate
than generation, thus increasing the volume of wastes sent to
disposal. Numerous uses for coal ash have been developed in
three categories: as fill material, in the manufacture of cement,
concrete, and pavements, and in miscellaneous uses such as ice
control and blasting grit. In 1977, about 21% of the 61.6 million
tons of coal ash generated was utilized. Current R & D projects
on ash focus on understanding existing uses and development of
new uses Including mineral recovery. FGD wastes are not
presently used in the U. S. Potential FGD utilization options may
include use as gypsum substitutes, as fillers and soil conditioners,
in cement and concrete manufacture, and in construction of
artificial reefs. A combination of technical, environmental, and
institutional barriers (the last being the most important) con-
strains utilization. Data gaps remain in quality requirements for
using coal ash and FGD wastes in specific applications and
understanding the institutional constraints to utilization.
The fifth volume of the five-volume report focuses on
disposal of coal ash and FGD wastes (which together comprise
FGC wastes). Disposal of these wastes represents significant
sources of environmental pollution unless proper disposal tech-
nologies are employed. Continued R & D efforts have provided
substantial baseline information on environmentally sound
disposal methods. This volume assesses the various options for
the disposal of FGC wastes with emphasis on disposal on land. It
appears that a number of technical, economic, and regulatory
factors will encourage increasing use of dry disposal methods.
Regulatory considerations impacting FGC waste disposal are
assessed. Regulations under the Resource Conservation and
Recovery Act, the major Federal legislation impacting FGC waste
disposal, are still emerging. An assessment of the monitoring
requirements from the viewpoints of regulation and environ-
mental control is reported. Ongoing studies on the economics of
FGC waste disposal are reported and assessed. Cost estimates for
sound disposal practices are $9.00 to $15.00 per dry metric ton
of waste. Environmental impact issues concerning disposal op-
tions include physical stability, public policy and land use] and
leachate mobility. A summary of data gaps and research needs in
this area is outlined.
The FGD Quarterly Report is part of a comprehensive EPA Engineering Application/Information Transfer (EA/IT) Program on flue gas
desulfurization (FGD). The report is designed to meet four objectives: (1) to disseminate information concerning EPA-sponsored and -conducted
research, development, and demonstration activities in FGD; (2) to provide progress updates on selected ongoing contracts; (3) to report final
results of various FGD studies; and (4) to provide interested persons with sources of more detailed information on FGD. The EA/IT Program is
sponsored by EPA's Industrial Environmental Research Laboratory. Research Triangle Park, North Carolina (IERL-RTP).
The FGD Quarterly Report Is prepared by Radian Corporation under EPA Contract No. 68-02-3171. The EPA Project Officer is J. E.
Williams, MD-61, USEPA, IERL-RTP, Research Triangle Park, NC 27711, (919) 541-2483 or (FTS) 629-2483. The Radian Project Director is
Elizabeth D. Gibson, Suite 820, 40 Broad Street, Boston, MA 02109, (617) 482-5666.
The Report is distributed, without charge, to persons interested in FGD. Those wishing to report address changes, or Initiate or cancel their
free subscriptions to the FGD Quarterly Report may do so by contacting the EPA Project Officer or Radian Project Director named above.
The views expressed in the FGD Quarterly Report do not necessarily reflect the views and policies of the Environmental Protection Agency.
Mention of trade names or commercial products does not constitute an endorsement or recommendation for use by EPA.
ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, N. C. 27711
FGD Quarterly Report
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