TVA
EPA
Tennessee Valley Authority Energy Demonstrations
Office of Power and Technology
Muscle Shoals Al 3566O
EOT-105
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-80-022
February 1980
Economics of Disposal
of Lime/Limestone
Scrubbing Wastes:
Surface Mine Disposal and
Dravo Landfill Processes
Interagency
Energy/Environment
R&D Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
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The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
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tems. The goal of the Program is to assure the rapid development of domestic
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essary environmental data and control technology. Investigations include analy-
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This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EOT-105
EPA-600/7-80-022
February 1980
Economics of Disposal
of Lime/Limestone
Scrubbing Wastes:
Surface Mine Disposal
and Dravo Landfill Processes
by
J.D. Veitch, A.E. Steele,
and T.W. Tarkington
TVA Office of Power
Division of Energy Demonstrations and Technology
Muscle Shoals, Alabama 35660
EPA Interagency Agreement No. D8-E721-BI
Program Element No. INE624A
EPA Project Officer: Julian W. Jones
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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DISCLAIMER
This report was prepared by the Tennessee Valley Authority and has
been reviewed by the Office of Energy, Minerals, and Industry, U.S.
Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and
policies of the Tennessee Valley Authority or the U.S. Environmental
Protection Agency, nor does mention of trade names or commercial products
constitute endorsement or recommendation for use.
ii
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ABSTRACT
Economic evaluations were made of flyash and limestone scrubbing
waste disposal in a surface mine and in a landfill after treatment with
a Dravo Lime Company chemical additive. For the base-case (new 500-MW
midwestern plant burning 3.5% sulfur, 16% ash, 10,500 Btu/lb coal),
capital investment for the mine disposal process is 16.0 $/kW and annual
revenue requirements are 0.98 mill/kWh, compared with 20.0 $/kW and 1.44
mills/kWh for the Dravo landfill process, excluding dry flyash collection
costs of 19.2 $/kW and 0.56 mill/kWh. A moderate cost reduction is
obtained for mine disposal, compared with landfill disposal of the same
waste, by elimination of disposal land requirements and reduction of
earthmoving equipment requirements. Purchase and handling of the chemi-
cal additive for the Dravo landfill process account for most of the cost
differences between the two processes. Power plant size, coal sulfur
and ash contents, and distance to the disposal site have major effects
on costs for both processes. Modular cost breakdowns show purchase and
handling of fixatives, thickening, ESP units, and disposal labor to be
major cost elements.
iii
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CONTENTS
Abstract ............................. ii:L
Figures .............................
Tables ............................. viil
Abbreviations and General Conversion Factors ........... x
Executive Summary ........................ xi
Introduction ........................... 1
Background ............................ 3
Flue Gas Cleaning Waste .................... 3
Dravo Process ......................... 4
Disposal in Coal Surface Mines ................. 5
Design and Economic Premises ................... 10
Design Premises ........................ 1°
Emission Standards ...................... 10
Fuel ............................. 11
Power Plant ......................... H
Power Plant Operation .................... 11
Flue Gas Composition ..................... 12
Scrubber Design ....................... 12
Waste Treatment and Disposal ................ 13
Case Variations ....................... 13
Economic Premises ....................... 13
Capital Costs ........................ 14
Annual Revenue Requirements ................. 16
Systems Estimated ........................ 19
Mine Disposal ......................... 19
Major Equipment ....................... 22
Other Equipment ....................... 22
Dravo Landfill Process .................... 26
Major Equipment ....................... 29
Other Equipment ....................... 29
Waste Quantities ....................... 29
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Results 37
Base Case 37
Case Variations 39
Power Plant Size and Operating Schedule 41
Power Plant Remaining Life 45
Sulfur in Coal 47
Ash in Coal 49
Distance to the Disposal Site 51
Modular Cost Comparisons 53
Waste Quantities 59
Base-Case Modular Cost Comparisons 72
Capital Investment Comparisons 74
Annual Revenue Requirements Comparison 75
Conclusions 76
Case Variations 76
Modular Cost Comparisons 77
Recommendations 79
References 80
Appendix
A. Capital Investment and Annual Revenue Requirement Tables . . 83
vi
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FIGURES
Number
S-l Process flow diagrams xxii
1 Approximate areas of coal surface mining in the United
States 6
2 Area surface mine 9
3 Mine disposal base-case flow diagram and material balance . 20
4 Mine disposal base-case equipment layout 21
5 Dravo landfill process base-case flow diagram and
material balance 27
6 Dravo landfill process base-case equipment layout 28
7 Effect of power plant size on disposal costs 44
8 Effect of power plant remaining life on disposal costs . . 46
9 Effect of coal sulfur content on disposal costs 48
10 Effect of coal ash content on disposal costs 50
11 Effect of distance to disposal site on disposal costs ... 52
12 Process flow diagrams 54
vii
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TABLES
Number ?age
S-l Waste Produced xv
S-2 Annual and Lifetime Waste Quantities and Disposal Area
Requirements . » . . . xvi
S-3 Base-Case Capital Investment xvii
S-4 Base-Case Annual Revenue Requirements xviii
S-5 Capital Investment Summaries Mine Disposal and Bravo
Landfill Processes xx
S-6 Annual Revenue Requirements Summaries Mine Disposal and
Dravo Landfill Processes xx
S-7 Modular Costs by Processing Area for Eight Disposal
Processes xxiii
1 Coal Compositions and Base-Case Flow Rates 11
2 Flue Gas Compositions, New 500-MW Units 12
3 Cost Indexes and Projections 14
4 Projected 1980 Unit Costs for Raw Materials, Labor,
and Utilities I6
5 Annual Capital Charges for Power Industry Financing ... 18
6 Mine Disposal Base-Case Equipment List 23
7 Dravo Landfill Base-Case Equipment List 30
8 Waste Produced 34
9 Annual and Lifetime Waste Quantities and Disposal Area
Requirements 36
10 Capital Investment Summaries Mine Disposal and Dravo
Landfill Processes 38
11 Annual Revenue Requirements Summaries Mine Disposal and
Dravo Landfill Processes 38
12 Effect of Case Variations on Unit Costs, Relative to
Base-Case Costs 40
13 Power Plant Size Variations, Declining Load, Capital
Investment 42
14 Power Plant Size Variations, Declining Load, Annual
Revenue Requirements 43
15 Constant Load Versus Declining Load 45
16 Modular Capital Investment - Ponding 55
17 Modular Annual Revenue Requirements - Ponding 56
18 Modular Capital Investment - Dravo Ponding 57
19 Modular Annual Revenue Requirements - Dravo Ponding ... 58
20 Modular Capital Investment - IUCS Process 60
21 Modular Annual Revenue Requirements - IUCS Process .... 61
22 Modular Capital Investment - Chemfix Process ....... 62
viii
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TABLES (continued)
Number
23 Modular Annual Revenue Requirements - Chemfix Process ... 63
24 Modular Capital Investment - Sludge - Flyash Blending ... 64
25 Modular Annual Revenue Requirements - Sludge -
Flyash Blending 65
26 Modular Capital Investment - Gypsum 66
27 Modular Annual Revenue Requirements - Gypsum 67
28 Modular Capital Investment - Mine Disposal 68
29 Modular Annual Revenue Requirements - Mine Disposal .... 69
30 Modular Capital Investment - Dravo Landfill 70
31 Modular Annual Revenue Requirements - Dravo Landfill ... 71
ix
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ABBREVIATIONS AND GENERAL CONVERSION FACTORS
ABBREVIATIONS
Btu
cc
ESP
0F
FGC
FGD
ft
ft/sec
g
gal
gpm
hp
hr
in.
k
kW
kWh
Ib
M
MW
NSPS
sec
British thermal unit
cubic centimeter
electrostatic precipitator
degrees Fahrenheit
flue gas cleaning
flue gas desulfurization
feet
feet per second
gram
gallon
gallons per minute
horsepower
hour
inch
thousand
kilowatt
kilowatthour
pound
million
megawatt
new source performance standards
second
CONVERSION FACTORS
To convert from
English units
To
Multiply by
acres
British thermal units
degrees Fahrenheit -32
feet
square feet
cubic feet
gallons
inches t^O head
miles
pounds
pounds per square inch
pounds per cubic foot
short tonsa
hectares
kilocalories
degrees Celsius
meters
square meters
cubic meters
liters
bars
meters
kilograms
bars
grams per cubic centimeter
metric tons
0.405
0.252
0.555
0.3048
0.093
0.0283
3.785
0.0025
1609
0.454
0.069
0.016
0.907
a. All tons are expressed in short tons in this report
x
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ECONOMICS OF DISPOSAL OF LIME-LIMESTONE SCRUBBING WASTES:
SURFACE MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
EXECUTIVE SUMMARY
INTRODUCTION
Large volumes of flyash and flue gas desulfurization (FGD) wastes
are produced by flue gas cleaning (FGC) processes. Disposal of these
wastes is an important concern for operators of coal-fired power stations.
Increased use of coal for electricity generation, increased use of
waste-producing FGD processes, and more stringent environmental regula-
tions for waste disposal are expected to complicate this concern in the
coming years. The Waste and Water Program sponsored by the U.S. Environ-
mental Protection Agency (EPA) deals with the numerous aspects of power
plant waste control and water pollution control. As part of this program
the Tennessee Valley Authority (TVA) has conducted several economic
evaluations of FGC waste disposal processes. This phase of the study
consists of economic evaluations of disposal in a surface mine and
landfill disposal of waste from a Dravo Lime Company fixation process.
In addition, costs for the base-case conditions of six processes evaluated
previously are included for comparison.
BACKGROUND
Lime and limestone scrubbing FGD processes produce a waste slurry
of 10% to 15% solids consisting of calcium sulfites and sulfates, unre-
acted absorbent, and flyash. Under the conditions used in this study
the slurry typically has a high sulfite to sulfate ratio, appreciable
unreacted limestone and limestone impurities, and trace amounts of
flyash. The high-sulfite sludge can be mechanically dewatered to about
50% to 60% solids and without further treatment is a poorly handling
semisolid of doubtful stability in landfill disposal.
Flyash, a simultaneously generated large volume waste, may be
disposed of separately or with the FGD waste. As a dry material it may
also be blended with the dewatered FGD waste to obtain additional dewater-
ing and increased stability, although flyash blending alone does not
produce a solid waste of satisfactory stability under all power plant
conditions.
XI
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FGD waste can be disposed of by direct ponding, by ponding after
dewatering to various degrees, or by dewatering and treatment with
additives to produce a solid waste for landfill disposal. Additives
such as flyash or purchased chemicals, or both, may be used to improve
handling and postdisposal characteristics. Several commercial fixation
processes are available in which additives such as lime, portland cement,
or proprietary materials are used, often in conjunction with flyash, to
produce hydraulic-cement reactions in the waste ingredients. The Dravo
process uses Calcilox,® a processed blast-furnace slag, as the fixative.
Surface coal mines are an attractive possibility for FGC waste
disposal because of their geographic distribution and the large volume
of excavation they represent. The use of the mine eliminates the need
for additional large areas of land for disposal and site maintenance can
be combined with or replaced by the extensive reclamation procedures now
practiced in surface mining.
Surface mining is extensively practiced in the Appalachian regions,
the Interior basins of the central Mississippi Valley, and in the Rocky
Mountains and Great Plains. Surface mines in the Appalachians are
typically smaller than those of other regions and often disadvantageous
in form and topographical location for use as waste disposal sites.
Area mining, in which a large area is progessively mined by successive
cuts, is more widely practiced in the Interior basins and the West.
Many western mines are very large, producing several million tons of
coal per year. Their ratio of overburden removed to coal removed
(stripping ratio) is also relatively low, leaving more volume for poten-
tial waste disposal. Although no geographic area is precluded from mine
disposal, western mines appear generally more adaptable to mine disposal.
Some surface mines are used for ash disposal. Two western area-
type surface mines are used for disposal of dewatered FGD waste disposal.
One of these, the Baukol Noonan, Inc., Mine near Center, North Dakota,
is used as a model for the mine disposal process evaluated in this
study. About A million tons per year of lignite in a main seam about 11
feet thick is recovered from beneath 50 to 150 feet of overburden. The
FGC waste is dumped from trucks on the pit floor or between spoil banks
before reclamation.
DESIGN AND ECONOMIC PREMISES
The premises used in this study are the same as those used for the
previous TVA studies of FGC waste disposal economics. A midwestern
power plant operating under regulated-utility economics and burning a
typical eastern bituminous coal is used as the basis for the evaluations.
Case variations, in which one design premise is varied to evaluate its
economic effects, are included. The plant is assumed to meet 1971 new
source performance standards (NSPS) of 0.10 Ib/MBtu flyash emission and
1.2 Ib/MBtu S02 emission.
xii
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Design Premises
The base case is a new 500-MW power plant with a 9000 Btu/kWh heat
rate. A 30-year declining-load operating schedule of 127,500 hours and
a 7,000-hour first-year operating schedule are used. Case variations
consist of 200- and 1500-MW new power plants, existing power plants with
25, 20, and 15 years remaining life, and a constant-load 7,000 hr/yr
(210,000 hours total) operating schedule. A 9200 Btu/kWh heat rate is
used for the 200-MW and existing 500-MW power plants.
The base-case fuel is a 3.5% sulfur, 16% ash coal with a 10,500
Btu/lb high heating value. Case variations for fuel consist of coals
with 2% and 5% sulfur and 12% and 20% ash. The flue gas composition is
based on an air rate of 133% of stoichiometric requirements and emission
of 80% of the ash in the coal as flyash and 95% of the sulfur in the
coal as sulfur oxides.
The scrubber waste is based on a 15% total solids effluent sludge
produced by a limestone system operating at a CaC03 to sulfur removed
stoichiometric molar ratio of 1.5, using 95% CaC03 limestone. The
sulfur species in the sludge is assumed to be 85% CaS03-l/2H20 and 15%
CaSO^^HoO. The remaining solids are unreacted limestone and limestone
impurities. Waste treatment consists of dewatering the scrubber effluent
and blending the dewatered sludge with dry flyash (and Calcilox for the
Dravo landfill process). The waste is trucked to the disposal site.
For the base case the disposal site is located 1 mile from the
power plant. Case variations of 5 and 10 miles are also included. For
the mine disposal process, the waste is dumped between spoil banks. For
the Dravo landfill process an area landfill with a 30-foot waste depth
is used. Land costs are based on requirements for the life of the power
plant.
jjconomic Premises
Capital investment using mid-1979 costs and first-year annual
revenue requirements using mid-1980 costs are calculated based on a
60:40 debt to equity ratio, 10% interest on bonds, and a 14% return to
stockholders. Process costs consist of all waste processing and disposal
costs downstream from the scrubber effluent waste line and the electrostatic
precipitator (ESP) ash collection hoppers. ESP costs are included as a
separate entity.
Capital costs consist of direct costs for process equipment and its
installation, all ancilliary equipment, and other supportive installa-
tions; indirect construction costs; contingencies; land; and working
capital. Annual revenue requirements (based on 7000 hours of operation)
consist of raw materials costs; direct costs for labor and supervision,
maintenance, utilities, and disposal operations; and indirect costs for
capital charges and overheads.
xiii
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PROCESS DESCRIPTIONS
Mine Disposal
The 15% solids scrubber effluent is thickened to 35% solids in a
thickener. The thickener underflow is filtered on rotary vacuum filters
to 60% solids and conveyed to a pug mill mixer. Flyash, pneumatically
conveyed from the ESP units to storage silos, is also fed to the mixer
using a weigh feeder. The blended waste, containing 74% solids in the
base case, is conveyed to an adjacent concrete storage area. The waste
is loaded into dump trucks with a front loader and hauled to the mine
over mine haul roads. The waste is dumped between spoil banks. A
crawler dozer is used to maintain access to the dumping area and manage
the waste. The waste is covered during normal reclamation operations.
It is assumed that no additional mining or reclamation costs are incurred
by the mine operator and that no fees are paid by the power plant.
Dravo Landfill Process
The same thickening and filtration operations are performed on the
FGD sludge as described for the mine disposal process. The dewatered
waste is blended in the mixer with flyash. In addition, Calcilox is
added to the mixer at a rate of 7% of the solids in the FGD sludge. The
Calcilox is received by rail and pneumatically unloaded into 30-day-
capacity storage silos. From the silos it is conveyed to a weigh feeder
that meters it to the mixer. The blended waste, containing 75% solids,
is conveyed by belt conveyors to a roofed concrete-floored storage area.
The waste is loaded and transported in the same manner as the mine
disposal process waste.
At the landfill site successive blocks are stripped of topsoil and
the waste is deposited to a depth of 30 feet. The waste is covered
daily with 1 foot of subsoil and given a final 3-foot topsoil cover. A
scraper, crawler dozer, roller, and watering truck are used to maintain
the site.
Waste Produced
The waste is assumed to have a bulk density of 97 Ib/ft^ and the
physical characteristics of a loose soil. The waste quantities and
compositions are shown in Table S-l. The yearly quantities and disposal-
area requirements are shown in Table S-2.
RESULTS
The capital investment and annual revenue requirements for the base
cases are shown in Tables S-3 and S-4. These results and other results
in the text do not include ESP capital investment of $9,614,000 (19.2
$/kW) and annual revenue requirements of $1,975,000 (0.56 mill/kWh),
which may be added for comparison with other FGD processes. ESP costs
are included as a separate entity to allow comparison with previously
xiv
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TABLE S-l. WASTE PRODUCED
Scrubber sludge - Ib/hr
Base case
Variations from base case
200 KW
1500 MU
25 years remaining life
20 years remaining life
15 years remaining life
27, sulfur in coal
5% sulfur in coal
12% ash in coal
W7. ast\ in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
J500 MW, constant load
Sulids
61,400
25,100
184,300
62,800
62,800
62,800
27,iOO
95,700
57,200
b&.lOQ
61,400
61,400
25,100
61,400
184,300
Water
41 ,000
16,700
122,800
41,900
41,900
41,900
18,100
63,800
38,100
44 , 100
41,000
41,000
16,700
41,000
122,800
Flyash - Ih/hr
54,400
22,300
163,200
55,600
55,600
55,600
53,400
54 , 900
38,500
72,300
54,400
54,400
22,300
54,400
163,200
Calcilox - lb/hra
4 , 300
1,800
12,900
4/.00
4,400
4,400
1,900
6,700
4,000
'i,600
4,300
'\ , 300
1,800
4 , 300
1? ,900
Total - mine disposal
Lb/hr
156,800
64,100
470,300
160,300
160,300
160/300
98,600
214,400
133.800
182,500
156,800
156,800
64,100
156,800
470.300
% solids
74
74
74
74
74
74
32
70
72
76
74
74
74
74
74
Total - Dravo landfill
Lb/hr
161,100
65,900
483,200
164,700
164,700
164,700
100,500
221,100
137,800
187,800
161,100
161,100
65,900
161,100
483.200
% solids
75
75
75
75
75
75
82
71
72
76
75
75
75
75
75
a. Dravo process onlv; 7% Calcilox, based on scrubber solids.
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TABLE S-2. ANNUAL AND LIFETIME WASTE QUANTITIES AND DISPOSAL AREA REQUIREMENTS
Mine disposal
Acres/first year
Tons/first year (5 ft depth)
Base case
Case variations
200 MW
1500 MW
25 years remaining lifea
20 years remaining life*5
15 years remaining lifec
2% sulfur in coal
5% sulfur in coal
122 ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
7,000 hr/yr constant schedule
200 MW
500 MW
1500 MW
548,800
224,400
1,646,100
561,100
561,100
561,100
345,100
750,400
468.30Q
638,800
548,800
548,800
224,400
548,800
1,646,100
52
21
156
53
53
53
33
71
44
61
52
52
21
52
156
Acres/lifetime
(5 ft depth)
947
386
2,838
702
436
247
595
1,293
807
1,102
947
947
636
1,560
4,674
Dravo landfill
Acres/first year
Tons/first year (30 ft depth)
563,900
230,700
1,691,200
576,500
576,500
576,500
351,800
773,900
482,300
654,900
563,900
563,900
230,700
563,900
1,691,200
8.9
3.6
26.7
9.1
9.1
9.1
5.6
12.2
7.6
10.3
8.9
8.9
3.6
8.9
26.7
Acres/lifetime
(30 ft depth)
162
66
486
120
75
42
101
222
139
188
162
162
109
267
800
Basis: 97 lb/ft^ bulk density, wet waste, no in-place compaction. First year based on 7,000 hours of operation. Lifetime operation
127,500 hours except as noted, a. 92,500 lifetime hours, b. 57,500 lifetime hours, c. 32,500 lifetime hours, d. 210,000
lifetime hours.
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TABLE S-3. BASE-CASE CAPITAL INVESTMENT
Capital investment, k$
Process equipment
Piping and Insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Mine disposal
1,985
139
242
53
345
56
504
3,324
50
3,374
559
3,933
322
81
686
272
5,294
1.059
6,353
579
762
7,694
14
288
7,996
16.0
Dravo landfill
2,161
151
264
58
367
60
654
3,715
56
3,771
790
4,561
426
107
752
301
6,147
1.229
7,376
659
885
8,920
581
523
10,004
20.0
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash (and
Calcilox in Dravo landfill process), and trucked 1 mile to disposal;
mid-1979 cost basis.
xvii
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TABLE S-4. BASE-CASE ANNUAL REVENUE REQUIREMENTS
Annual revenue requirements, k$
Mine disposal Dravo landfill
Direct Costs
Delivered raw materials
Calcilox 966
Total raw material costs 966
Conversion costs
Operating labor and supervision
Plant 438 *38
Disposal equipment 596 745
Plant maintenance - 4% of
direct investment 157 182
Landfill operation
Landfill preparation
Truck fuel and maintenance 33 3Zt
Earthmoving equipment fuel
and maintenance 66 "
Electricity 108 108
Analyses 12. —
Total conversion costs 1,383 1,629
Total direct costs 1,383 2,595
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment 602 698
Average cost of capital and taxes
at 8.6% of total capital investment 688 860
Overhead
Plant, 50% of conversion costs less
electricity 653 76°
Administrative, 10% of total labor
and supervision 103 118
Total indirect costs 2,047 2,437
Total annual revenue requirements 3,430 5,032
Equivalent unit revenue requirements
Mills/kWh 0.98 1.44
$/ton waste 6.3 8.9
$/ton solids 8.5 11.9
Basis: One-year, 7,000-hour operation of system described in capital
investment summary; mid-1980 cost basis.
xviii
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evaluated processes, some of which utilized wet-scrubbing flyash removal.
Capital investment is $7,996,000 (16.0 $/kW) for the mine disposal
process and $10,004,000 (20.0 $/kW) for the Dravo landfill process.
Higher direct costs for process equipment and higher mobile equipment
and land costs in the Dravo landfill process account for most of the
differences in costs. Annual revenue requirements are $3,430,200 (0.98
mill/kWh) for the mine disposal process and $5,032,400 (1.44 mills/kWh)
for the Dravo landfill process. The differences are due to the cost of
Calcilox, higher disposal labor costs, and higher indirect costs based
on capital investment for the Dravo landfill process. The cost of
Calcilox, which accounts for 37% of the Dravo landfill process direct
costs, accounts for 60% of the annual revenue requirement cost difference
between the processes. Labor and supervision, particularly disposal
labor and supervision, is the dominant direct cost element in both
processes, accounting for 75% of the mine disposal process direct costs
and 46% of the Dravo landfill direct costs.
Case Variations
Capital investment and annual revenue requirements summaries for
the case variations are shown in Tables S-5 and S-6. Power plant size
variation has the largest effect on costs for both processes. For 200-,
500-, and 1500-MW power plants, the capital investments are 29.6, 16.0,
and 10.9 $/kW for the mine disposal process and 35.9, 20.0, and 13.8
$/kW for the Dravo landfill process. For the same 200-, 500-, and 1500-
MW power plants, annual revenue requirements are 1.79, 0.98, and 0.60
mills/kWh for the mine disposal process and 2.43, 1.44, and 0.98 mills/kWh
for the Dravo landfill process. Economy of scale in equipment and in
labor and supervision is responsible for the variations in cost. The
rate of increase in costs with power plant size is greater for the Dravo
landfill process because of its raw material and disposal-area land
costs, which increase linearly with size.
Reductions in remaining lives to 25, 20, and 15 years increase the
mine disposal process costs slightly because of the higher heat rate for
existing plants and the accelerated depreciation schedule. These same
effects in the Dravo landfill process are counteracted by decreasing
disposal-area land costs, resulting in a slight decrease in the capital
investment with age. Annual revenue requirements for the Dravo landfill
process increase slightly with age because of the accelerated depreciation
schedule.
The sulfur content of the coal has an appreciable effect on the
cost of both processes. For coal sulfur contents of 2.0%, 3.5%, and
5.0%, capital investment is 14.1, 16.0, and 18.3 $/kW for the mine
disposal process and 17.2, 20.0, and 23.8 $/kW for the Dravo landfill
process. For the same coal sulfur contents, annual revenue requirements
are 0.84, 0.98, and 1.14 mills/kWh for the mine disposal process and
1.12, 1.44, and 1.90 mills/kWh for the Dravo landfill process. Raw
material, disposal labor and supervision, and mobile equipment costs are
most affected. The Dravo landfill process annual revenue requirements
xix
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TABLE S-5. CAPITAL INVESTMENT SUMMARIES
MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
Mine disposal
Condition
Base case
Variations from base case
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
k$
7,996
5,917
16,306
8,067
8,067
8,067
7,056
9,161
7,422
8,589
8,554
8,846
5,917
7,996
16,308
$/kW
16.0
29.6
10.9
16.2
16.2
16.2
14.1
18.3
14.8
17.2
17.1
17.7
29.6
16.0
10.9
$/tona
0.80
1.46
0.55
1.09
1.75
3.10
1.12
0.67
0.87
0.74
0.86
0.88
0.88
0.80
0.33
Dravo landfill
k$
10,004
7,180
20,632
9,960
9,793
9,677
8,586
11,923
9.3Q2
10,749
10,573
10,843
7,330
10,392
21,783
$/kW
20.0
35.9
13.8
19.9
19.6
19.4
17.2
23.9
18.6
21.5
21.2
21.7
36.7
20.8
14.5
$/ton'
0.97
1.71
0.67
1.31
2.07
3.6.?
1.34
0.85
1.06
0.90
1.03
1.06
1.74
1 01
0.71
Based on total dry solids,as disposed of, during the life of the
power plant.
TABLE S-6. ANNUAL REVENUE REQUIREMENTS SUMMARIES
MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
Mine disposal
Condition
Base case
Variations from base case
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
kS
3,430
2,508
6,336
3,523
3,562
3,679
2,938
3,974
3,294
3,604
4,128
4,545
2,508
3,430
6,336
Mills/
kWh
0.98
1.79
0.60
1.01
1.02
1.05
0.84
1.14
0.94
1.03
1.18
1.30
3 .79
0.98
0.60
$/ton
waste3
6.25
11.18
3.85
6.28
6.35
6.56
8.51
5.30
7.03
5.64
7.52
8.28
11.18
6.25
3.85
$/ton
solids
8.45
15.10
5.20
8.49
8.58
8.86
10.38
7.46
9.77
7.42
10.17
11.19
15.10
8.45
5.20
k$
5,032
3,397
10,322
5,149
5,179
5,304
3,910
6,666
4,799
5,297
5,735
6,185
3,410
5,066
10,421
Dravo landfill
Mills/
kWh
1.44
2.43
0.98
1.47
1.48
1.52
1.12
1.90
1.37
1.51
1.64
1.77
2.44
1.45
0.99
$/ton
wastea
8.90
14.72
6.10
8.93
8.98
9.20
11.11
8.61
9.95
8.09
10.17
10.97
14.78
8.98
6.16
$/ton
solids
11.90
19.63
8.14
11.91
11.98
12.27
13.55
12.13
13.82
10.64
13.56
14.62
19.71
11.98
8.22
a. Wet waste, as disposed of, based on 7,000 hours of operation.
XX
-------
increase more rapidly with increase in coal sulfur content than those of
the mine disposal process because of the raw material costs for Calcilox.
Coal ash content has a moderate effect on costs, similar to but
less than the effect of coal sulfur content. For coal ash contents of
12%, 16%, and 20% capital investment is 14.8, 16.0, and 17.2 $/kW for
the mine disposal process and 18.6, 20.0, and 21.5 $/kW for the Dravo
landfill process. Annual revenue requirements are 0.94, 0.98, and 1.03
mills/kWh for the mine disposal process and 1.37, 1.44, and 1.51 mills/kWh
for the Dravo landfill process.
Distances to the disposal site of 5 and 10 miles instead of the
base-case 1-mile distance produce slight increases in capital investment
because of increased truck requirements. The annual revenue requirements
for the 1-, 5-, and 10-mile distances are 0.98, 1.18, and 1.30 mills/kWh
for the mine disposal process and 1.44, 1.64, and 1.77 mills/kWh for the
Dravo landfill process. The increases are largely due to increased
trucking labor and operating costs.
Modular Cost Comparisons
Base-case cost breakdowns by processing area were made for the two
processes evaluated in this study and the six processes previously
evaluated. Schematic flow diagrams are shown in Figure S-l. Two of the
six processes are ponding processes—untreated ponding and a Dravo
fixation process in which the sludge is thickened and mixed with lime
and Calcilox before ponding. Two are landfill fixation processes in
which the sludge is thickened, filtered, and blended with fixatives.
The IUCS process fixative is lime. The Chemfix process fixatives are
Portland cement and sodium silicate. In the IUCS process the waste is
processed at the power plant and trucked to the landfill. In the Chemfix
process the thickened sludge is pumped to the landfill where it is
filtered, fixed, and distributed on the landfill with scrapers. One
process consists of a sludge - flyash blending process in which the
sludge is thickened, filtered, blended with dry flyash, and trucked to a
landfill. The remaining process uses an air-oxidation scrubber modifica-
tion to produce a high-sulfate (gypsum) sludge that is thickened, filtered,
and trucked to a landfill without further treatment. In all processes
not using dry flyash, the flyash is removed in the scrubber. Flyash is
included on the FGD sludge, and the equipment is sized accordingly, for
processes not requiring dry flyash because of the design premises in use
at the time of the earlier studies. For comparison purposes the additional
costs of ESP units and scrubber effluent air-oxidation modifications are
included as additional costs. The modular cost breakdowns are shown in
Table S-7.
In those cases in which flyash is collected separately the cost of
ESP units constitutes about one-half of the capital investments. In
annual revenue requirements separate flyash collection accounts for
about one-third of the total for these three processes. In comparison,
simultaneous flyash removal results in relatively modest increases in
thickening and filtration costs. Separate collection of flyash is,
xxi
-------
UNTREATED PONDING
POND
DRAVO PONDING
THICKENER
CALCILOX
^
1
LIME
MIXER
*.
POND
IUC5
THICKENER
FILTER
MIXER
LANDFILL
CHEMFIX
THICKENER
CEMENT
FILTER
1
SILICATE
MIXER
/
SLUDGE -FLYASH BLENDING ^
THICKENER
• • w
FILTER
MIXER
LANDFILL
GYPSUM
AIR
OXIDATION
THICKENER
FILTER
LANDFILL
MINE DISPOSAL
THICKENER
*-
FILTER
^
MIXER
"TMINEJ—
DRAVO LANDFILL
Figure S-l. Process flow diagrams.
LANDFILL
xxii
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TABLE S-7. MODULAR COSTS BY PROCESSING AREA FOR EIGHT DISPOSAL PROCESSES
X
X
Capital investment by processing area. $/kW
uther Raw materials Thickening Filtration
Ponding
Dravo ponding 9.0
IUCS 4,2
Chemf ix 7 m 4
Sludge - fly ash blending 19. 2a 4.4
Gypsum 4 . fib
Mine disposal 19.2& 4.4
Dravo landfill 19.2a 6.2
Annual
Ponding
Dravo ponding 0.91
IUCS 0.44
Chemf ix 0.94
Sludge - fly ash blending 0.56C 0.22
Gypsum 0.29^
Mine disposal 0.56C 0.22
Dravo landfill 0.56C 0.57
Basis: 500-MW power plant, 127,500-hour life, 7,
fly ash removal in scrubber where cost is
waste to disposal system.
8.4
8.5
8.7
6.3
5.2
6.2
6.0
4.1
4.2
2.5
3.0
2.5
2.2
Mixing
1.4
0.5
1. 1
1.5
0.9
0.9
0.8
Storage Disposal
33.0
30.3
Q z.
•j . ~j
5.3
1. 1
•J . -1.
") ft
£- . O
o 0
£. m\J
1.1 3.8
Total
34 4
-J^T * *T
48.2
71 A
t- 1 . *t
77 i
£- f . 1
OfL /.
JD . f
1 C A
1 J . t
oc q
JJ . j
39.4
revenue requirements by processing area, mills /kWh
0.24
0.29
0.28
0.24
0.29
0.25
0.22
000 hr/yr
not shown
0.18
0.17
0.11
0.16
0.11
0.10
revenue requirement
0.14
0.03
0.06
0.05
0.05
0.05
0.05
basis:
Limestone scrubber, 1.5
0.80
0.74
0.54
0.56
0.45
0.44
0.36
0.03 0.47
3.5% sulfur, 16% ash
0 Q4
U « 37H
1.91
1.51
2 00
^ • \J \J
1.64
1 18
J- • ±. \J
1 54
X • J*T
2.00
coal;
stoichiometry, 15% solids
a. $9,614,000 ESP cost for separate fly ash collection.
b. $2,303,000 air-oxidation modifications.
c. $1,975,000 ESP operating costs.
d. $1,005.000 air-oxidation operating costs.
-------
of course, possible with all of the processes evaluated and would require
similar costs for all processes. In comparison of landfill processes
with separate flyash collection, cost differences would largely be
reduced to cost differences in the raw material portion of the cost
breakdown.
For processes using purchased fixatives raw materials are an
important element of both capital investment and annual revenue require-
ments. Flyash handling is also a relatively expensive element. The
advantage of a single fixative is illustrated by comparison of raw
material costs for the Dravo ponding and Chemfix processes, which use
two additives, with the IUCS process which uses one. The IUCS process
has raw material capital investment and annual revenue requirements
about one-half those of the others.
Thickening is the largest capital investment cost element, excluding
ESP costs, for all of the nonponding processes and is also a large cost
element in annual revenue requirements. The gypsum process has a major
advantage over the other processes in thickening capital investment but
little in thickening annual revenue requirements.
Filtration is also a large cost element, though considerably less
so than thickening. Filtration costs for the gypsum process are lower
than the other simultaneous flyash-FGD waste filtration processes because
of the superior filtration characteristics of the high-sulfate sludge.
Mixing costs are a minor part of both capital investment and annual
revenue requirements.
Transportation and disposal-site costs illustrate fundamental
differences between ponding and solid waste disposal methods. Capital
investment for pond construction is an order of magnitude greater than
the capital investment for trucks and landfill site operations. Capital
investment for transport lines is also an important element. For the
Chemfix process, in which the thickened sludge is pumped to the disposal
site for further treatment, the cost of transport lines is not offset by
the minor savings in mobile equipment. Among the landfill and mine
disposal processes, transportation and disposal-site costs are a relatively
minor element of total capital investment. As a percentage of total
capital investment disposal land costs for all the processes (excluding
mine disposal which has none) are similar, ranging from 8% for untreated
ponding to 5% for the Chemfix process.
Annual revenue requirements for ponding process transportation and
disposal-site operations are also higher than the same costs for landfill
and mine disposal processes, although the differences are less pronounced
than the capital investment differences. About two-thirds of the annual
revenue requirement direct costs for ponding consist of pond operations.
Transportation of the waste is a relatively minor cost element. In
contrast, about four-fifths of the direct costs for transportation and
disposal-site operations in the landfill and mine disposal processes are
for loading and hauling.
xxiv
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Process Comparisons
In overall comparison of the processes evaluated, the most important
capital investment cost elements are separate flyash collection, raw
material handling, thickening, and pond waste disposal. Untreated
ponding, with almost all of the capital investment in transportation and
pond costs, has a relatively high capital investment. Dravo ponding
which combines high raw material costs for two additives, thickening
costs, and ponding costs has the highest capital investment. Among
landfill fixation processes the Dravo landfill process has the highest
capital investment, almost half of which is ESP costs for separate
flyash collection.
Sludge - flyash blending and mine disposal differ only slightly in
capital investment. The reduction in mobile equipment and land require-
ments effected by use of the mine as a disposal site accounts for the
difference in capital costs between the two processes.
The difference in capital investments between the IUCS and Chemfix
processes is largely in raw material handling costs as a result of the
additional fixative. However, additional costs for transportation of
the waste also occur because the waste is processed at the disposal
site. A similar effect in raw material costs between one- and two-
fixative processes is seen in the two-fixative Dravo ponding process.
The considerably lower capital investment of the gypsum process is
a result of the low cost of the necessary scrubber modifications, improved
thickening and filtration characteristics, and a reduction in transporta-
tion and landfill costs.
Large cost elements in annual revenue requirements are separate
flyash collection, raw material purchase and handling, and disposal.
Untreated ponding has the lowest annual revenue requirements, almost all
of them for disposal. The Dravo landfill process (with costs for both
separate flyash collection and a fixative) and the Chemfix process (with
costs for two fixatives and higher transportation costs) both have high
annual revenue requirements. Dravo ponding, with two fixatives, but no
ESP and filtration costs, has slightly lower annual revenue requirements.
The IUCS process, with one fixative, and no ESP costs, has the lowest
annual revenue requirements of the fixation processes. If dry flyash
were used in the IUCS process, however, it would be similar in cost to
the other fixation processes.
The small difference in annual revenue requirements between the
sludge - flyash blending and mine disposal processes is a result of
reduced landfill costs and lower indirect costs based on capital invest-
ment .
The gypsum process annual revenue requirements are second only to
ponding. The low cost is a result of relatively modest additional costs
for air oxidation, the absence of raw material and mixing costs, and
lower transportation and landfill costs than other landfill processes.
xxv
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CONCLUSIONS
Mine disposal is approximately one-fifth lower in capital investment
and one-third lower in annual revenue requirements than the Dravo landfill
process. The cost differences are largely a result of additional costs
for purchase and handling of Calcilox. Reduced disposal costs for the
mine disposal process are minor.
Cost reductions directly associated with mine disposal are a result
of reductions in land and mobile equipment requirements and reduced
disposal labor and mobile equipment operating costs. The costs associated
with the use of a fixative lie largely in purchase of Calcilox and instal-
lation of equipment for handling it. Waste processing and disposal
costs are not greatly affected by the use of the fixative. ESP costs
are a large part of the total FGC costs for both processes.
Other large capital investment cost elements for both processes are
raw materials handling (which includes flyash) and thickening. Labor
and supervision costs, particularly for disposal operations, are the
largest direct cost element in annual revenue requirements. Disposal-
site operations, consisting of fuel, maintenance, and land preparation
are minor costs. Utility costs are also minor.
Power plant size has the largest effect on costs of the case vari-
ations studied, largely because of economy of scale, particularly in
process equipment, and lower labor and supervision costs, relative to
plant size, at the larger power plant sizes. The effect of power plant
size on the Dravo landfill process annual revenue requirements is less
pronounced because it has raw materials and disposal land costs linearly
related to waste quantities.
Coal sulfur content produces large differences in the capital
investments and annual revenue requirements for both processes. The
variations are greater for the Dravo landfill process because of the
effects of disposal-area land requirements and raw material require-
ments, which are not factors in the mine disposal process. Coal ash
content also had an important effect on capital investment and annual
revenue requirements, although less than coal sulfur content in the
ranges evaluated.
The increased distance to the disposal site produces a moderate
increase in capital investment and a large increase in annual revenue
requirements for both processes. The results indicate that hauling
distance is an important consideration. Mine disposal is an economically
favorable disposal option in comparison to on-site disposal only for the
more favorable circumstances of mine location. For the five-mile dis-
tance to the disposal site the increase in trucking costs eliminate the
cost savings associated with mine disposal instead of on-site landfill.
Breakdown of costs into modular processing areas for the eight
processes evaluated in this series of studies illustrates the effect of
various process functions. ESP costs, for processes in which flyash is
xxvi
-------
collected separately, are a large part of both capital investment and
annual revenue requirements. Excluding ESP costs, raw material purchase
and handling, thickening capital investment, and pond capital investment
are high-cost areas.
Raw material costs are also an important part of annual revenue
requirements when purchased fixatives are used. The use of more than
one fixative compounds the costs in these areas because they are almost
completely additive. Flyash handling, although larger in volume, is not
greatly higher in cost than purchased fixative handling.
Thickening is a large cost element. Filtration is less costly and
mixing is a minor cost.
Capital investment for transport lines and pond construction is an
order of magnitude greater than mobile equipment and landfill-site
capital investment.
In comparison of the seven processes for high-sulfite waste, ponding
is shown to be a low-cost disposal option, if practical, if there is no
treatment of the sludge. Treatment and fixation before ponding add the
high-cost processing areas without materially reducing pond costs.
Landfill processes, excluding ESP costs, are lower in capital investment
than ponding processes. This advantage is reduced when purchased fixa-
tives are used, particularly if two are used. Landfill annual revenue
requirements are only competitive with ponding if no purchased fixatives
are used.
The gypsum process results illustrate the large decrease in capital
costs attainable by improvement in stoichiometry and the dewatering
characteristics of the waste. Annual revenue requirements for the
gypsum process are intermediate between untreated ponding or landfill
without purchased fixatives and the landfill processes with purchased
fixatives.
RECOMMENDATIONS
The results indicate that certain cost-sensitive areas, such as
thickening and filtration, can be studied as modules applicable to
several processes. Such comparisons would more clearly illustrate cost
similarities and differences among processes.
Transportation whether by truck or pipeline is also an important
cost factor, many elements of which are independent of particular processes.
Transportation alternatives should particularly be investigated in
greater variety and with emphasis on energy requirement costs. Landfill
preparation and operation should be investigated with emphasis on definition
of additional costs for site investigations, pollution control, monitoring,
xxvii
-------
and reclamation costs associated with existing and pending legislation.
Legislation, such as the Resources Conservation Recovery Act, should be
continually kept in perspective. In addition, the rapidly increasing
body of information on waste chemical and physical characteristics and
disposal data from evolving technologies should be incorporated into
future studies. Processes, such as the gypsum process, that have not been
commercially demonstrated could change significantly in cost as information
on them develops.
xxviii
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ECONOMICS OF DISPOSAL OF LIME-LIMESTONE SCRUBBING WASTES:
SURFACE MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
INTRODUCTION
An important part of the operation of a modern coal-fired power
plant is the disposal of flue gas cleaning (FGC) wastes. These wastes
include large quantities of flyash (produced by particulate matter
removal) and sulfur-salt sludge (produced by the majority of present
flue gas desulfurization—FGD—processes). Disposal of these wastes
presents problems because of the volume of material and the environmental
effects their transportation and disposal may create. The increased use
of coal for electricity generation projected for the next 20 years
(Hayes, 1979, and Griffith, 1979, summarize a number of these projections)
can be expected to intensify these problems.
Numerous regenerable FGD processes are in various stages of develop-
ment and application; numerous studies of useful applications for FGC
products are also in progress. The prospect for the foreseeable future,
however, is an increasing production of waste from emission control
processes which must be disposed of (Santhanam and others,. 1979).
Laseke and Devitt (1979) list 16,000 MW of utility FGD systems in opera-
tion and an additional 46,000 MW under construction or planned, most of
which are waste-producing processes. It is predicted that 25% of coal-
fired facilities will be equipped with FGD systems by 1986. Leo and
Rossoff (1978a) projected production of FGD wastes to 1998 for a number
of control strategies and emission limits. Their projections for waste-
disposal land requirements in 1998 range to an extreme of 350 square
miles nationally for exclusive use of limestone-scrubbing FGD.
Environmental concerns about FGC waste disposal center on chemical
and physical characteristics of the wastes which affect pollution of
ground and surface waters and physical characteristics which affect
reclamation and subsequent use. Failure of impoundments, fugitive dusts
and gases, and visual affects of large waste sites are other concerns
which impinge on waste disposal considerations. The influence of environ-
mental legislation, particularly the Resource Conservation and Recovery
Act (RCRA) of 1976, has not been fully assessed. Some disposal methods
may be precluded or circumscribed, either generally or on an individual
basis (Duvel and others, 1979).
-------
During the past several years EPA has sponsored the Waste and Water
Program which is concerned with the numerous aspects of power plant
waste control and water pollution control. The program deals in part
with the technology and economics of FGC waste disposal. TVA has con-
ducted two previous studies under this program on the economics of
several alternative FGD waste disposal methods (Barrier and others,
1978, 1979). This study continues these studies with economic evaluations
of disposal of FGC waste in a surface mine and landfill disposal of FGC
waste chemically treated in a Dravo Lime Company fixation process.
Disposal of FGC waste in mines is an obviously attractive disposal
method. Large disposal-site land requirements are eliminated. In most
cases extensive reclamation is required following mining operations,
which can replace or be combined with similar operations required for
FGC waste disposal sites. In some cases the FGC waste might serve a
useful function in subsidence control or in control of mine runoff
acidity. Lunt and others (1977) made an extensive assessment of FGC
waste disposal in mines, finding both underground and surface mine
disposal technically feasible though subject to numerous site-specific
factors. A few power plants dispose of flyash in surface mines (Kelley,
1979). In early 1979 there were two commercial utility applications of
FGD waste disposal in mines, both in Western area-type strip mines.
Texas Utilities Company uses mine disposal at their Martin Lake power
station. The FGD sludge is dewatered, blended with dry flyash, and
transported to the nearby mine by rail cars. At the Minnkota Power
Cooperative Milton R. Young Power Station near Center, North Dakota, FGC
waste is trucked to the nearby Baukol Noonan, Inc. , mine serving the
power plant. The sludge is the product of a wet-scrubbing system using
flyash from the plant electrostatic precipitator (ESP) units and lime as
the absorbents. The disposal operation is being evaluated by EPA through
a grant to the University of North Dakota (Manz and Gullicks, 1979) for
field measurements and a contract with Arthur D. Little for overall
assessment of the operation. The mine disposal evaluation in this study
is modeled in part on this operation.
This study deals primarily with FGD waste disposal costs. These
costs are therefore treated as an entity, separate from other control
procedures which may be necessary in the power plant operation. Flyash
removal is treated as a separate cost. Other waste collection and
disposal procedures which may be necessary, such as bottom ash and waste
water disposal, are not included. With the increasing comprehensiveness
of pollution control regulations, however, an integrated system incorpo-
rating all aspects of waste disposal may prove economically advantageous.
-------
BACKGROUND
FLUE GAS CLEANING WASTE
The waste product in most lime and limestone scrubbing processes
consists of a 10% to 15% solids slurry of calcium sulfur salts, unreacted
absorbent, and flyash. The calcium salts consist primarily of calcium
sulfite hemihydrate (CaS03-l/2H20) and gypsum (CaSO^-2H20), either of
which can be the dominant species, depending on the flue gas and scrub-
bing conditions. The ratio of sulfite to sulfate is a primary factor
in determining sludge characteristics affecting both dewatering and
postdisposal behavior. The properties of FGD sludges related to sulfite
to sulfate ratio have been summarized by Leo and Rossoff (1976, 1978b),
and Santhanam and others (1979). Limestone scrubbing wastes also contain
appreciable quantities of unreacted limestone and limestone impurities.
Flyash is present in trace to major quantities depending on upstream
removal efficiencies.
Under the conditions in this study, using a typical eastern bitumi-
nous coal and scrubbing with limestone slurry to meet the 1.2 Ib S02/MBtu
new source performance standards (NSPS), the scrubber effluent typically
has a high sulfite to sulfate ratio. The slurry can be dewatered to
about 60% solids, in which condition it is a poorly handling material of
uncertain stability. Different fuel and scrubbing conditions or forced-
air oxidation can produce a high-gypsum sludge with improved dewatering
and stability characteristics. Disposal of gypsum from forced-air
oxidation was evaluated in a previous phase of these studies (Barrier
and others, 1979).
The collection and disposal of flyash is closely bound, if not
integral, to considerations of FGD waste disposal. As a simultaneously
generated large volume of waste, codisposal with FGD waste may offer
economic and practical benefits. In addition, flyash can aid in dewater-
ing and stabilization of the FGD waste. Flyash is, however, enriched in
the many trace and minor elements in coal and can contribute to con-
taminants in leachate from the waste. The characteristics of flyash,
both as a separate material and as a component of FGC waste, have been
extensively reported. Leo and Rossoff (1978b) and Coltharp and others
(1979) provide recent summaries of pertinent studies. The behavior of
heavy metals associated with flyash-soil environments has been reported
by Theis and others (1977).
Several alternatives are available for disposal of FGD wastes from
wet-scrubbing processes. It can be pumped directly to a disposal pond
-------
which serves as a settling basin for partial water recovery. It can be
dewatered to various degrees by intermediate ponding or by mechanical
methods before being ponded or impounded. In addition, flyash or
chemical additives, or both, can be added to improve handling or post-
disposal properties. All of these methods have been or are used. The
present trend is toward increased dewatering and stabilization (Santhanam
and others, 1979).
Stabilization using additives is attractive because it can reduce
uncertainties of both short- and long-term behavior of FGD wastes.
Treatments which reduce permeability, decrease liquefaction tendencies,
or improve compressive strength reduce concerns about seepage and runoff
contamination, structural failure, and land reuse. In addition, handling
properties can be improved, allowing a wider selection of transportation
and emplacement methods.
Stabilization by addition of non-FGC additives, some in conjunction
with flyash, has been widely investigated. Fling and others (1978) have
described field tests in progress at the EPA-TVA Shawnee test facility.
Leo and Rossoff (1976, 1978b) summarize these and other investigations.
A number of companies offer or have offered fixation processes, most of
them proprietary. Duvel and others (1978) have summarized these processes.
The Dravo Lime Company and IU Conversion Systems (IUCS) presently operate
commercial facilities. Other utilities operate nonproprietary fixation
processes. Leo and Rossoff (1978b) report 15 power plants operating or
committed to chemical treatment of FGD waste by 1979.
Most chemical treatment, or fixation, processes employ additives
which produce a series of hydraulic reactions between lime, silica, and
alumina similar to those that occur in the setting of hydraulic cement.
Flyash is often used to provide the silica and alumina. Lime is often
used as an additive to supplement low-calcium flyashes. Fixation processes
can be designed to compensate for the numerous site-specific conditions
associated with FGC wastes and to produce a product adapted to specific
disposal requirements. This degree of flexibility is not as great in
sludge - flyash blending processes, since the composition is fixed by the
amount and composition of FGC wastes being produced. In some cases flyash
alone is not sufficient to produce a solid waste of acceptable handling
and postdisposal properties.
DRAVO PROCESS
The Dravo process is based on a patented fixation process of the
Dravo Lime Company. The Dravo process uses a proprietary material
called Calcilox® derived from blast-furnace slag. Calcilox, which is
sometimes compared to portland cement, has a similar composition, though
higher in alumina. Its reactions in water are similar to those of a
hydraulic cement. When Calcilox is added to wet FGD sludge these reac-
tions, and reactions into which the gypsum in the sludge also enters,
produce a sludge of increased strength and reduced permeability. The
curing period is dependent on the amount of Calcilox used, the solids
-------
content of the waste, and chemical and physical conditions such as pH
and temperature. Lime is sometimes used to accelerate the reactions.
The Dravo process can be used in three variations. In the full
impoundment method the Calcilox is mixed with thickened sludge and
pumped to a pond for final disposal. This method is used in a commercial
operation at the Pennsylvania Power Company's Bruce Mansfield Station.
Alternately, the treated sludge can be pumped to a pond for curing,
after which it is excavated and disposed of as landfill material. This
interim ponding method was used at the Duquesne Light Company's Phillips
Power Station. Both of these methods were included in a previous TVA
economic evaluation of sludge disposal methods (Barrier and others,
1978).
The third method consists of mechanical dewatering of the FGD
sludge to the extent that it can be handled as a solid and disposed of
directly as landfill. The Calcilox is added either during dewatering or
after dewatering in a separate mixing step. The latter method is used
in this study.
DISPOSAL IN COAL SURFACE MINES
With the exception of stone quarrying, surface mining of coal is
the most geographically diffuse of U.S. mining operations. Figure 1
shows the general distribution of coal surface mining in the United
States. In 1975 coal surface mining was conducted in 24 states
(Westerstrom and Harris, 1977). Not shown is a large area of northern
California and eastern Oregon and Washington where scattered operations
have been or are conducted (Westerstrom, 1976). With the exception of
the Pennsylvania anthracite regions these areas represent bituminous,
subbituminous, and lignite mining operations that can be divided into
three regional groupings: the Appalachian region, the Interior basins,
and the Rocky Mountains and Great Plains. Each region is characterized
by conditions of terrain, geology, and climate which differentiate it to
some degree from the other regions. Mining methods are adapted to these
conditions and consequently follow regional patterns. Chironis (1978)
summarizes modern surface mining techniques on a regional basis. Environ-
mental regulations have led to considerable modification of surface
mining techniques in recent years. The additional effect of regulations
stemming from the Surface Mining Control and Reclamation Act of 1977 is
likely to lead to additional changes in techniques and mining patterns
(Todd, 1979). The use of surface mines as FGC waste disposal sites is
influenced both by the regional patterns of mining techniques and by the
environmental regulations that affect these operations.
In the Appalachians (excluding the eastern Pennsylvania anthra-
cite regions) variations of contour stripping and box cut mining are
widely used surface-mining methods designed to cope with rugged terrain.
The coal outcrop is followed along a hillside, mining into the slope as
far as overburden removal is economically feasible. Additional coal may
-------
Figure 1. Approximate areas of coal surface mining in the United States.
(derived from Chironis, 1978, Averitt, 1975)
-------
be removed by augering or other mining methods. In the past the spoil
was dumped downslope and the mined area was left as a sinuous hillside
bench with a highwall on the upslope side.
Environmental regulations controlling downslope spoil casting and
requiring restoration of original contours have led to modifications of
these methods (Coal Age, 1978). Reclamation methods using haulback
techniques or block cutting are widely used. Haulback consists of
continual transportation of spoil to the previously mined area where it
is emplaced to restore original contours. Block cutting involves mining
of blocks in successions designed to allow spoil from each block to be
placed in the previously mined block.
Hilltop or mountaintop removal, in which the coal is mined completely
across a hilltop, is also used in the Appalachian regions. Area mining
is used in locations where the terrain is suitable.
Considerable attention is placed on spoil control in most of these
mining operations. Segregation of topsoil and toxic materials is often
necessary. Drainage and seepage are also important concerns. Topographi-
cal control of runoff, structured fills, catchment areas, and reduction
of unreclaimed area are important in reducing potential water pollution
problems.
Considered as potential disposal sites Appalachian surface mines
suffer several disadvantages less pronounced in surface mines of other
regions. The mines are smaller and often located in remote and rugged
terrain. They may also be poorly sited topographically to be used as a
disposal site for wastes with a potential for water pollution. Mining
operation modifications designed to meet environmental regulations also
complicate the use of the mines for disposal. The unreclaimed area is
reduced and pit congestion is increased, making coordination of a major
waste disposal operation with the mining operation more difficult.
Although not precluding waste disposal, these conditions may make it less
generally applicable in the Appalachian region than elsewhere.
Area-type surface-mining methods can be used where relatively flat-
lying beds and low relief permit mining over a large continuous area.
Area mining is most used in the Interior basins and particularly in the
Great Plains and Rocky Mountain Regions. In the Western United States,
area mines producing several million tons per year, and eventually to
mine coal from thousands of acres, are not uncommon. Jackson (1978)
describes a number of these mines. Area mining begins with an initial
longitudinal cut of convenient width to accommodate the equipment used.
A subsequent cut is made along the highwall of this pit and the spoil is
dumped into the first cut. Mining continues in this manner over the
area to be mined, with the spoil from each cut being dumped into the
preceeding cut. The dumped spoil forms long rows and conical piles
which may fill the mined-out pit or only partially cover the floor,
depending on the ratio of overburden to coal removed (stripping ratio)
and the increase in volume of the spoil over the undisturbed overburden
volume (swell ratio). Reclamation follows as closely as practical
-------
behind the mining operation to minimize potential pollution and erosion
problems. This generally consists of leveling and contouring of the
spoil, replacement of topsoil, and revegetation.
Area surface mines appear to be best suited to FGC waste disposal.
They are generally larger size and the volume of production provides a
potentially greater volume for disposal. In larger mines the scale of
waste disposal operations is less likely to approach the scale of mining
operations, reducing the effect of mutual interference and the necessity
of close coordination. The shape of the mined area and the generally
less-rugged terrain may reduce difficulties of seepage control and
monitoring. In addition reclamation is usually to restore a rolling
terrain in which concerns of slope stability are less extensive than in
steeply sloping areas. In area mines of extensive size, waste placement
so that it does not interfere with future mining of unrecovered coal is
also more feasible. In mining operations such as contour stripping
waste disposal could be objectionable on the grounds that unrecovered
coal could be contaminated or its recovery hindered.
Area surface mines, of course, have as wide a geographical distribu-
tion as surface mines in general. Smaller area mines are not uncommon
in Ohio, Pennsylvania, and Alabama. Large area mines are common in the
Interior basins, though Illinois and western Kentucky, the major producers,
produced almost as much coal by underground mining as by surface mining
of all types in 1975 (Westerstrom, 1977). In contrast, the West and
Southwest are predominately area-type surface-mining regions. Only in
Utah (which has no surface mines) and Iowa did underground production
exceed surface production in 1975 (Westerstrom, 1977).
A large, area mine with a relatively low stripping ratio is used as
the basis for the mine disposal process in this study. A conceptual
model of such a mine is shown in Figure 2. Such a mine is represented
by the Baukol-Noonan, Inc., Center Mine near Center, North Dakota, that
supplies lignite to the adjacent Minnkota Power Cooperative, Inc.,
Milton R. Young Power Station. The main lignite seam is about 11 feet
thick and is overlain by 50 to 150 feet of poorly consolidated to uncon-
solidated clays and underlain by a similar clay. Production capacity is
over 4 million tons per year. In 1978 these mining operations extended
over three sections of rolling grassland. Overburden was being stripped
by dragline from the highwall side and dumped in irregular rows in the
previous cut. The lignite was removed by a shovel on the pit floor and
hauled to the power plant in off-road trucks. The exposed pit floor
remaining was generally about 200 feet wide. Roads were bulldozed
between the spoil pile rows. Reclamation proceeded at a sufficient
distance behind stripping to leave an area more than sufficient for
waste disposal.
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Figure 2. Area surface mine.
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DESIGN AND ECONOMIC PREMISES
The premises used in this evaluation are the same as those used in
the two previous TVA evaluations of FGC waste disposal (Barrier and
others, 1978, 1979). The design premises specify the location, design,
and operation of the power plant. The economic premises specify the
economic conditions under which the plant is built and operated and the
methodology of cost calculations. The premises specify a midwestern
power plant burning an eastern coal and operating under regulated-
utility economics. Case variations in which one condition is varied to
evaluate the economic effects of changes in certain conditions are also
included.
DESIGN PREMISES
The utility plant design and operation is based on Federal Energy
Regulatory Commission (FERC) historical data and TVA experience. The
conditions used are representative of a typical modern boiler for which
FGD systems would be most likely considered. A midwestern location
typical of Illinois, Indiana, and Kentucky is used. The design for both
processes is assumed to be proven in commercial operation. No provisions
are made for additional spares or special sizing to compensate for
unknown design and operating factors.
Emission Standards
NSPS established by EPA in 1971 (Chaput, 1976, summarizes these
regulations) are used in this study. These specify a maximum emission
of 0.10 Ib/MBtu for particulate matter and 1.2 Ib/MBtu for S02- The
flyash and scrubber efficiencies required for the coal ash and sulfur
contents evaluated are:
% in coal Removal efficiency - % in flue gas
Sulfur Ash Sulfur Flyash
2.0 16 63 99.5
3.5 16 79 99.5
5.0 16 85 99.5
3.5 12 79 99.3
3.5 20 79 99.6
Detailed cost estimates in this study include both particulate
removal by ESP and all waste-related costs beginning with the FGD scrubber
effluent. Costs for a limestone scrubber without waste processing and
disposal facilities, calculated using the same premise conditions, are
included as a total sum.
10
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Fuel
The coal compositions are composites of several hundred samples
representing major U.S. coal production areas. Sulfur contents of 2.0%,
3.5%, and 5.0% dry basis and ash contents of 12%, 16%, and 20% wet basis
are used. The coal has a heating value of 10,500 Btu/lb, as fired. The
as-fired compositions and flow rates for the 500-MW unit size are shown
in Table 1.
TABLE 1. COAL COMPOSITIONS AND BASE-CASE FLOW RATES
2.0% sulfur 3.5% sulfur 5.0% sulfur
Component
C
H2
N2
02
s
Cl
Ash
H20
Total
Wt %
58,03
4.17
1.30
7.81
1.80
0.15
16.00
10.74
100.00
Lb/hr
248,700
17,900
5,600
33,500
7,700
600
68,600
46,000
428,600
Wt %
57.56
4.14
1.29
7.00
3.12
0.15
16.00
10.74
100.00
Lb/hr
246,800
17,700
5,500
30,000
13,400
600
68,600
46,000
428,600
Wt %
56.89
4.09
1.27
6.40
4.46
0.15
16.00
10.74
100.00
Lb/hr
244,000
17,500
5,400
27,400
19,100
600
68,600
46,000
428,600
Power Plant
A single, balanced-draft, horizontal, frontal-fired boiler design
is used. For the base case a 500-MW net output unit is used as repre-
sentative of units now being constructed or planned (Kidder, Peabody &
Co., 1978). Case variations of 200-MW and 1500-MW (composed of three
500-MW units) are used to represent the size ranges most commonly encoun-
tered in current utility construction.
Power Plant Operation
A power plant operating life of 30 years with a declining number of
operating hours per year is used. The operating schedule is shown
below:
Operating
Operating year Capacity factor, % hours per year
1-10
11-15
16-20
21-30
Total
Average
80
57
40
17
48.5
7,000
5,000
3,000
1,500
127,500
4,250
11
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The same schedule is used for existing plants; existing units 5,
10, and 15 years old have remaining operating lives of 92,500, 57,500,
and 32,500 total hours. Case variations representing a 30-year life
with a constant 7000 hours per year operating schedule are also evaluated.
A heat rate of 9000 Btu/kWh is used for new 500-MW units. A heat rate
of 9200 Btu/kWh is used for existing 500-MW units and new 200-MW units.
Flue Gas Composition
Flue gas composition is the result of fuel, boiler design, and a
variety of operating conditions. The compositions used in this study
were calculated for the boiler and coals described above. A total air
rate of 133% of stoichiometric requirements was used. This consists of
20% excess air to the boiler and 13% inleakage. These values represent
TVA experience with this type of boiler design. It is assumed that 80%
of the ash in the coal and 95% of the sulfur in the coal are emitted in
the flue gas. It is also assumed that 99% of the sulfur emitted is SC>2
and the remainder is 803. The flue gas compositions used for new 500-MW
units are shown in Table 2.
TABLE 2. FLUE GAS COMPOSITIONS, NEW 500-MW UNITS
Flue gas
component
N2
02
co2
S02
so3
NO
HC1
H20
Flyash
2.0% sulfur,
Ib/hr
3,439,000
257,400
911,600
14,500
183
3,002
661
265,400
54,880
3.5% sulfur,
Ib/hr
3,450,000
258,200
904,200
25,130
317
3,009
661
264,500
54,880
5.0% sulfur,
Ib/hr
3,443,000
257,800
894,700
35,920
454
3,000
661
262,400
54,880
Scrubber Design
The scrubber system is a wet limestone slurry system. The design
is generic, based on TVA operating experience, general industry informa-
tion, and information from process equipment vendors. Four parallel
trains are used for the 500-MW units and two parallel trains are used
for the 200-MW units. A single mobile-bed scrubber with a presaturator
and mist eliminator is used in each train.
Scrubber stoichiometry is 1.5 moles of CaC03 Per m°le °f SOX
removed. The limestone is assumed to be 95% CaCOo and 5% inert minerals
which are discarded in the waste. The scrubber slurry is assumed to
contain 15% total solids, consisting of sulfur salts, unreacted limestone,
12
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and inert material from the limestone. The sulfur salts are assumed to
be 85% calcium sulflte hemihydrate (CaS03'l/2H20) and 15% calcium
sulfate dihydrate
Waste Treatment and Disposal
The sludge from the scrubbers is dewatered with conventional thick-
eners and vacuum filtration to a solids content of 60%. Recovered water
is returned to the scrubber system. The sludge and dry flyash (and
Calcilox® in the Dravo landfill process) are mechanically blended to
form a waste of 70% to 82% solids. This material is assumed sufficiently
dewatered to be handled on conveyors and loading equipment as a soillike
material. The bulk density is assumed to be 1.56 g/cc (97 Ib/ft^).
Front loaders and rear-dump on-road trucks are used for loading and
transporting the waste. Conventional earthmoving equipment is provided
for the disposal site.
The landfill site is assumed to be level and suitable for typical
landfill use. The size of the landfill is based on the lifetime volume
of waste produced and a fill depth of 30 feet.
Case Variations
Case variations, consisting of a change in one design premise while
holding the others at the base-case conditions, are included to determine
the sensitivity of the process economics to operating condition variations.
The case variations used in this study are shown below.
Case variations
Premise condition Base case Mine disposal Dravo landfill
Both processes
Power plant size, MW 500 200, 1,500 200, 1,500
Remaining life, years 30 25, 20, 15 25, 20, 15
Lifetime operating hours 127,500 210,000 210,000
Sulfur in coal, % 3.5 2, 5 2, 5
Ash in coal, % 16 12, 20 12, 20
Miles to disposal site 1 5, 10 5, 10
ECONOMIC PREMISES
The economic premises are based on regulated utility economics.
They are designed to provide a breakdown of capital investment costs for
construction of the system and first-year annual revenue requirements
for its operation. The capital structure is assumed to be 60% debt and
40% equity. Interest on bonds is 10% and the return to stockholders is
14%. The premise criteria define cost indexes; equipment installation,
land, and other construction costs; capital charges and interest; and
operating costs. Capital costs are obtained from engineering, processing,
and equipment manufacturing firms, and TVA cost data. Procedures are
13
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developed from publications dealing with costs and estimating such as
Peters and Timmerhaus (1968) and Popper (1970). Revenue requirement
direct costs are based on current labor and supervisory rates, current
material and utility costs, and industry practices.
The premises represent projects in which design begins in mid-1977
and construction is completed in mid-1980, followed by a mid-1980 startup.
Capital costs are assumed 50% expended in mid-1979. Capital costs are
projected to mid-1979 and revenue requirements are projected to mid-
1980. Scaling to other time periods can use mid-1979 as the basis for
capital costs and mid-1980 as the basis for revenue requirements.
Capital Costs
Capital costs are categorized as direct investment, indirect invest-
ment, contingency, other capital charges, land costs, and working capital.
Total fixed investment consists of the sum of direct and indirect capital
costs and a contingency based on direct and indirect investment. Total
depreciable investment consists of total fixed investment plus the other
capital charges. Investment costs are projected from historical Chemical
Engineering annual cost indexes (1974-1976) as shown in Table 3. The
costs are based on construction of a proven design and an orderly
construction program without delays or overruns caused by equipment,
material, or labor shortages.
TABLE 3. COST INDEXES AND PROJECTIONS
Year 1974 1975 1976 1977a 1978* 19793 198Q3 198ia
Plant
Material13
Labor0
165.4
171.2
163.3
182.4
194.7
168.6
197.9
210.3
183.8
214.7
227.1
200.3
232.9
245.3
218.3
251.5
264.9
237.9
271.6
286.1
259.3
293.3
309.0
282.6
a. Projections.
b. Same as index in Chemical Engineering for "equipment, machinery,
supports."
c. Same as index in Chemical Engineering for "construction labor."
Mobile equipment is assigned a 6-year life, based on industry
practice. Replacement is covered by an increased interim replacement
allowance in revenue requirements.
Direct Investment—
Direct capital costs consist of all costs, excluding land, for
materials and labor to install the complete waste disposal system.
Included are site preparation, excavation, buildings, storage facilities.
landscaping, paving, fencing, and 6600 feet of paved road. Process
equipment includes all major equipment and all equipment ancillary to
14
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the major equipment, such as piping, instrumentation, electrical equip-
ment, and vehicles. Services, utilities, and miscellaneous costs
involved in construction are 1.5% of the direct investment.
Indirect Investment—
Indirect investment costs consist of various contractor charges and
fees and construction expenses. The following cost divisions and determi-
nations are used.
Engineering design and supervision—This cost is calculated as a
function of the complexity of the system as determined by the number of
major equipment items, excluding mobile equipment. The empirical formula
used is:
Engineering design and supervision = (8900)(1.294)(number of
major equipment pieces)
Architect and engineering contractor expense—This expense is
calculated as 25% of the engineering design and supervision costs for
major equipment items.
Construction expense:—This expense includes temporary facilities,
utilities, and equipment used during construction. The expense is
calculated as an empirical function of direct investment:
Construction expense = 0.25 (direct investment excluding
landfill equipment in M$)0.83
Contractor fees—Direct investment is also used to determine con-
tractor fees:
Contractor fees = 0.096 (total direct investment in M$)
Cont ingency—
Contingency is 20% of the sum of direct investment and indirect
investment.
Other Capital Charges—
Other capital charges consist of an allowance for startup and
modifications and interest during construction. The allowance for
startup and modifications is 10% of the total fixed investment excluding
mobile equipment. Interest during construction is 12% of the total
fixed investment. It is based on the simple interest which would be
accumulated at 10% per year under the premise construction and expendi-
ture schedule.
Land—
Total land requirements, including the waste disposal area, are
assumed to be purchased at the beginning of the project. A land cost of
$3500 per acre is used.
15
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Working Capital—
Working capital consists of money invested in raw materials and
supplies, products in process, and finished products; cash retained for
operating expenses; accounts receivable; accounts payable; and taxes
payable. Working capital is assumed to be equivalent to the sum of 3
weeks of raw material costs, 7 weeks of direct costs, and 7 weeks of
overhead costs.
Annual Revenue Requirements
Annual revenue requirements are based on a 7000 hr/yr operating
schedule using the same operational profile and remaining life assumptions
that were used for the power plant design premises. Costs are projected
to 1980 dollars to represent a mid-1980 startup. The revenue requirements
are divided into direct costs for raw materials and conversion and
indirect costs for capital charges and overheads.
Direct Costs—
Projected direct costs for raw materials, labor, and electricity
are shown in Table 4. Operating labor and supervision is based on the
quantity, size, and complexity of the major process equipment. Labor
for analyses is based on the number of chemical analyses and physical
tests needed for process control. Electrical requirements are determined
from the operating horsepower of electrical equipment. The rates are
based on purchase from an independent source with full capital recovery
provided and are adjusted for the quantity used.
TABLE 4. PROJECTED 1980 UNIT COSTS
FOR RAW MATERIALS, LABOR, AND UTILITIES
$/unit
Calcilox 64.00/ton
Labor
Operating labor 12.50/man-hr
Analyses 17.00/man-hr
Mobile equipment 17.00/man-hr
200 MW 500 MW 1500 MW
Utilities
Electricity, kWh 0.031 0.029 0.027
Fuel and maintenance costs for mobile equipment are based on informa-
tion from companies operating similar disposal and transportation systems.
A cost of $0.16 per ton of waste is used for earthmoving equipment for
16
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the Dravo landfill process. A cost of $0.12 per ton of waste is used
for mine disposal because only a bulldozer is required. Truck rates for
the different distances are:
Distance traveled, miles $/ton of waste
1 0.06
5 0.20
10 0.39
Landfill operation costs for the Dravo landfill process are assigned
a value of $1700 per acre of landfill required. These costs are allocated
by acreage actually used—filled to 30 feet and covered with soil—
during the period costed.
Other maintenance costs are based on the direct investment costs.
They are adjusted for the size and complexity of the system and are
assumed to be constant over the life of the plant, the increase in costs
balanced by the decline in operating hours. Maintenance costs of 4% of
the direct investment are used for all conditions.
Indirect Costs—
Indirect costs consist of capital charges and overheads. A summary
of capital charges, based on regulated utility economics, is shown in
Table 5. Straight-line depreciation is used, based on the remaining
life of the power plant when the FGC system is installed. The allowance
for interim replacement is increased to 2.1% to 2.5%, depending on the
age of the power plant, from the usual average of about 0.35% because of
the unknown life span of FGC systems and the short life (6-year) of the
mobile equipment. The insurance and property tax allowance is 2.0% of
the total depreciable capital investment. Cost of capital is based on
the assumed capital structure. Plant overhead is assumed to be 50% of
the total conversion cost less the cost of utilities. Administrative
overhead is assumed to be 10% of the total labor and supervision cost.
17
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TABLE 5. ANNUAL CAPITAL CHARGES FOR POWER INDUSTRY FINANCING
Years remaining life
Depreciation - straight line (based on
years remaining life of power unit)
Interim replacements (equipment having
less than 30-year life)
Insurance and property taxes
Total rate applied to original
investment
Percentage of total depreciable
capital investment
30 25 20 15
3.3 4.0 5.0 6.7
2.5 2.4 2.3 2.1
2.0 2.0 2.0 2.0
7.8 8.8 9.3 10.8
Cost of capital (capital structure
assumed to be 60% debt and 40% equity)
Bonds at 10% interest
Equity3 at 14% return to stockholder
Income taxes (Federal and State)
Percentage of unrecovered
capital investment
6.0
5.6
5.6
Total rate applied to depreciation base
17.
a. Contains retained earnings and dividends.
b. Applied on an average basis. The total annual percentage of
original fixed investment for new plants would be 7.8% + 1/2
(17.2%) = 16.4%.
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SYSTEMS ESTIMATED
The generic designs used in this study were developed from material
balances, flowsheets, and layout diagrams using the design premises as
specifications. Major equipment design and costs were obtained from
equipment vendors, engineering firms, and internal TVA information.
Other equipment such as piping, electrical equipment, instrumentation,
and structures is based on standard engineering design methods and
industry practice.
The evaluations are limited to the dewatering and disposal require-
ments of the processes. Both processes begin with the equipment which
receives the 15% solids slurry from the limestone scrubber and the dry
flyash from the ESP units. For purposes of comparison with complete FGC
processes, costs of the ESP units and a limestone scrubber without waste
disposal facilities are included as a single sum.
MINE DISPOSAL
This process consists of a conventional thickener and vacuum filter
dewatering system for the FGD slurry, followed by blending of the FGD
sludge with dry flyash. The blended waste is loaded, trucked to the
mine, and emplaced using standard solids-handling equipment. The base-
case flow diagram and material balance is shown in Figure 3. The equip-
ment layout is shown in Figure 4.
The 15% solids slurry from the scrubber purge streams is pumped to
an agitated thickener feed tank with a 45-minute capacity. The slurry
is pumped to the 160-foot-diameter thickener where it settles to form a
35% solids underflow. Thickener overflow is returned to the scrubber
feed preparation area. Thickener underflow is filtered on rotary vacuum
filters to form a 60% solids cake. Filtrate is returned to the scrubber
feed preparation area. The filter cake is conveyed to a pug mill mixer
where it is mixed with a metered quantity of dry flyash to form a 74%
solids waste. The waste is conveyed to a concrete pad storage area.
Flyash collected in the ESP unit collectors is pneumatically con-
veyed to two steel storage silos with a combined capacity of 60 hours.
The flyash is fed by gravity to a feed bin supplying a belt weigh feeder
which meters it to the mixer.
The waste is loaded in rear-dumping on-road trucks for transporta-
tion to the mine. A wheeled front-end loader is used to manage the
storage pile and load the trucks.
19
-------
RAW MATERIALS
N3
O
TRANSPORTATION AND DISPOSAL
STREAM NO
DESCRIPTION
LB/HR
GPM
UN01SSOLVEO SOLIDS, H
SLURRY
TO
FEED TANK
409.480
745
1.10
19
2
SLURRY
TO
THICKENER
409,460
745
1.10
15
3
RECYCLE
WATER TO
ABSORBER
239.989
468
0
4
UNDERFLOW
TO
FILTER
175.491
277
1.27
35
5
RECYCLE
H.O FROM
FILTER
75.121
146
1.00
6
FILTER
CAKE TO
MIXER
102.3 7O
131
1.56
60
7
FLYASH
TO
MIXER
54.407
zoo
6
MATERIAL
TO
DISPOSAL
156.777
no
74
Figure 3. Mine disposal base-case flow diagram and material balance,
-------
ROAD
ROAD
THICKENER
FEED TANK
THICKENER
OVERFLOW
TANK
CONTROL
BUILDING
FLYASH STORAGE SILOS
r
i
i
I 1
] FILTER
1
FLYA
9FEED
1
SH
BIN
1
MIXER
ROAD
Figure 4. Mine disposal base-case equipment layout.
-------
For the base case the mine is assumed to be located one mile from
the power plant. The waste is assumed to be dumped between the spoil
pile rows. A crawler dozer is provided to maintain access roads and for
control of the waste as required. It is assumed the waste will not be
piled to depths greater than that obtained in dumping from the trucks to
insure deep burial and minimize ground movement resulting from differen-
tial settling between localized beds of waste in the spoil. It is also
assumed that reclamation is unaffected by the presence of the waste and
that leveling of the spoil will cover the waste with the upper portions
of the spoil piles. Similar assumptions would apply for the alternates
of dumping the waste in mined portions of the working cut (leaving room
for movement of mining equipment) or from roads constructed across the
spoil piles. These methods are considered more likely to affect mining
operations and are thus less generally applicable in a conceptual model.
No costs other than those associated with transportation of the
waste and maintenance of the disposal area are assigned to the disposal
operation. Other costs would depend on site-specific factors such as
lease relationships, the relationship between the mine operator and the
power plant, the operator's valuation of possible effects on his operation,
and actual effects created by conditions at a specific mine.
Major Equipment
The base-case major equipment list is shown in Table 6. The equip-
ment list is divided into major processing areas representing the modular
division of cost by area. For purposes of comparison with other processes
flyash handling is included in the raw materials handling area because
it is similar in handling characteristics and process effects to a
purchased raw material. The waste storage area is a concrete pad with
concrete retaining walls and is not equipped with process equipment.
Other Equipment
Other equipment consists of all ancillary equipment such as struc-
tures, piping, electrical equipment, and mobile equipment necessary for
the process.
Piping-
Stainless steel is used for slurry lines under 3 inches in diameter.
Rubber-lined carbon steel is used for slurry lines 3 inches and larger
in diameter. Carbon steel is used for all process and utility water
lines.
Foundation and Structural—
Foundations and supporting structures are based on the size and
weight of the equipment and necessary supporting structure.
Electrical—
Electrical equipment consists of feeder lines from the power plant
transformer yard, transformers and motor control centers, lines to
22
-------
TABLE 6. MINE DISPOSAL
BASE-CASE EQUIPMENT LIST
Area 1—Raw Materials Handling
Item
No.
Description
1. Pneumatic conveyor 1
system, flyash
2. Storage silo, 2
flyash
3.
Feeder,
discharge
Vibrator, fly-
ash storage silo
4.
5. Feed bin, flyash
6. Feeder, bin
discharge
7. Vibrator, feed
bin
8. Weigh feeder,
flyash
16
Complete system with blower, cyclone receiver,
receiver filter, 200 hp motor, 28 tons/hr
82,000 ft3, 1,600 tons, field erected, 41 ft
dia, 62 ft high, carbon steel with top, 60°
cone bottom
Rotary airlock type, 28,000 Ib/hr, 9 in. dia x
9 in. long, carbon steel
Electromechanical, rotary vibrators, 1 hp
motor
11,000 ft3, 19 ft dia, 38 ft high, with top,
60° cone bottom, carbon steel
Rotary airlock type, 9 in. dia, 9 in. long,
carbon steel
Electromechanical, rotary vibrators, 1 hp
motor
5 ft long, 24 in. belt, 2 hp motor, carbon
steel, 27 tons/hr
Area 2—Thickening
Item
No.
Description
1. Tank, thickener
feed
2. Agitator,
thickener
feed
34,000 gal, field erected, 18 ft dia, 18 ft
high, open top, carbon steel, rubber lined
with four 18 in. x 18 ft baffles, offset
3-1/2 in. from wall
25 hp, 72 in. dia blade, rubber coated
(continued)
23
-------
TABLE 6 (continued)
3.
4.
5.
6.
7.
8.
Area
1.
Item
Pump, thickener
feed
Thickener
Tank, thickener
overflow
Pump, thickener
overflow recycle
Pump, thickener
underflow to
filter
Sump pump ,
thickener
tunnel
3 — Filtration
Item
Filter, rotary
No.
Description
2 745 gpm, 75 ft head, rubber
motor
1 160 ft
basin
1 8,000
steel,
lined, 40 hp
dia, 10 ft high, rubber lined concrete
with rake and motor (1 spare motor)
gal, 12 ft dia, 10 ft high, carbon
rubber lined with flat bottom
2 468 gpm, 75 ft head, rubber
motor
2 277 gpm, 75 ft head, rubber
motor
1 5 gpm,
motor
No.
2 500 ft
lined, 20 hp
lined, 15 hp
10 ft head, carbon steel, 1/4 hp
Description
^ surface area, 12 ft
dia, 14 ft long
drum
2. Pump, filtrate
recycle
3. Conveyor, hori-
zontal belt
4. Conveyor,
sloping belt
drum, stainless steel (wetted parts), vacuum
and filtrate pumps included
146 gpm, 75 ft head, rubber lined, 15 hp
motor
52 tons/hr, 16 ft long, 24 in. belt,
100 ft/min, 3/4 hp
52 tons/hr, 30 ft long, 24 in. belt,
100 ft/min, 1 hp
(continued)
24
-------
TABLE 6 (continued)
Area 4—Mixing
1. Mixer, pug
mill
2. Conveyor,
sloping belt
2 78 tons/hr, 75 hp motor each, carbon steel
1 79 tons/hr, 30 ft long, 25 ft rise, 24 in.
belt, 100 ft/min, 5 hp
Area 5—Storage
No process equipment,
Area 6—Disposal
Item
No.
Description
1. Wheel loader
2. Disposal truck
3. Dozer
o
1 Front-end wheel loader with 4.5 yd bucket
3 35 ton capacity, 13 yd^, rear dump
1 Crawler dozer, 300 hp
25
-------
individual equipment items, and miscellaneous items required for the
electrical system. Line and equipment sizes are based on the connected
horsepower.
Instrumentation—
Instrumentation consists of all required sensors and control equip-
ment, graphic boards, annunciators, piping and wiring systems, and
panels.
Excavation and Site Preparation—
All excavation, grading, and installation of subbases required for
installation of foundations and roadways are included. The estimates
are based on the volume of material removed or emplaced.
Buildings—
A 1600 ft 12-foot-high control room building is provided for all
cases. A 3800 ft2 40-foot-high process building is used for the 200-
and 500-MW plant sizes. A 7500 ft2 40-foot-high building is used for
the 1500-MW plant size.
Roadways—
The equivalent of 6600 feet of bituminous-surfaced road is included
for all cases. This includes access roads, parking areas, and access
roadways for waste haulage.
DRAVO LANDFILL PROCESS
The mechanical dewatering and dry blending variation of the process
is used in this evaluation. For purposes of comparison the basic sludge -
flyash blending process is used to produce dewatered sludge. Additional
equipment for handling and blending of the Calcilox with the dewatered
sludge, along with the dry flyash, is included. The dry flyash provides
additional increase in solids content, insuring a short curing time and
a readily handling material. At the suggestion of Dravo a covered 72-
hour storage area was also included in the process. The base-case flow
diagram and material balance is shown in Figure 5. The equipment layout
is shown in Figure 6.
The FGD sludge dewatering system used is identical to the dewatering
system used for the mine disposal process. The 15% solids slurry from
the FGD system is dewatered to 35% solids in a thickener and filtered to
60% solids in a rotary vacuum filter. Thickener overflow and the filtrate
are returned to the scrubber feed preparation area. The filter cake is
transferred to a pug mill mixer by belt conveyor.
A pneumatic conveyor system is used to transport the flyash from
the ESP collectors to two steel storage silos with a total storage
capacity of 60 hours. Flyash flows by gravity from the storage silos
into the weigh feeder feed bin from which it is metered to the mixer in
a belt weigh feeder.
26
-------
STREAM NO
DESCRIPTION
LB/HR
SP GR
UND4SSOLVED SOLIDS. %
.
SLURRY
TO
FEED TANK
4O9.480
i to
13
2
SLURRY
TO
THICKENER
409,480
1 10
15
RECYCLE
WATER TO
ABSORBER
233.969
1 00
0
UNDERFLOW
TO
FILTER
1 79.491
1.27
35
3
RECYCLE
H.O FROM
FILTER
73,121
100
0
«
FILTER
CAKE TO
MIXER
102, 370^
1.56
60
FLYASH
TO
MIXER
94.407
2.OO _,
IOO
•
CALCILOX
TO
MIXER
4.5OO
1 36
100
9
BLENDED
PRODUCT TO
STOCKPILE
161 .077
).«0
74.6
Figure 5. Dravo landfill process base-case flow diagram and material balance,
-------
J I
ROAD
ROAD
RAILROAD
NJ
00
THICKENER
FEED TANK
THICKENER
OVERFLOW
TANK
RAILROAD
RAILROAD
CALCILOX
STORAGE
SILO
CONTROL
BUILDING
FLYASH STORAGE SILOS
CALCILOX
FEED BIN
FLYASH
BIN
FILTER
MIXER I
ROAD
Figure 6. Dravo landfill process base-case equipment layout.
-------
Calcilox is received by rail hopper car and unloaded into a steel
storage silo. The Calcilox is pneumatically conveyed to a feed bin and
metered to the mixer in a belt weigh feeder.
The blended waste from the mixer is transported by belt conveyor to
a roofed 72-hour storage area. A horizontal belt conveyor with a traveling
tripper distributes the waste along the 150-foot length of the storage
area.
A wheeled front-end loader is used to maintain the storage area and
load the on-road, rear-dump trucks which transport the waste to the
landfill.
The landfill is located one mile from the power plant. An area-
type fill is used in which blocks are successively cleared of topsoil,
filled to a 30-foot depth, and covered with soil. Equipment and pro-
visions are included for grading, soil covering, and site maintenance to
control runoff and erosion.
Major Equipment
The base-case major equipment list is shown in Table 7. The equip-
ment is divided into major process areas in a manner analogous to the
modular division of the mine disposal process. In this process a covered
waste area with a 3-day storage capacity is also provided.
Other Equipment
Other equipment such as piping, foundations and structures, and
electrical equipment is determined as discussed for the mine disposal
process. In addition to this equipment the storage area building and
equipment and a railway spur are included for this process. The spur is
assumed to connect to an existing spur adjacent to the FGD site.
WASTE QUANTITIES
The waste produced is calculated from the premise conditions of
sulfur oxides and flyash emitted and the amount removed to meet NSPS.
The scrubber sludge composition includes unreacted limestone and lime-
stone impurities based on the premise stoichiometry and limestone with
5% insoluble impurities. No flyash is included in the scrubber sludge.
The total quantity of waste is based on scrubber sludge dewatered to 60%
solids, completely dry flyash, and—for the Dravo landfill process—
addition of Calcilox equal to 1% of the weight of the scrubber sludge
solids. The waste quantities produced by the processes evaluated in
this study are shown in Table 8,
Many bulk density data on sludge - flyash mixtures are based on
measurements of core samples from impoundments and laboratory tests of
blends from scrubber systems. Leo and Rossoff (1978b) summarize results
of 92 lb/ft3 (1.48 g/cc) to 111 lb/ft3 (1.78 g/cc) for vacuum-filtered
29
-------
TABLE 7. DRAVO LANDFILL
BASE-CASE EQUIPMENT LIST
Area 1—Raw Materials Handling
Item
No.
Description
1. Pneumatic conveying 1
system, flyash
2. Storage silo,
flyash
3. Feeder, discharge
4. Vibrator, flyash 16
storage
5. Feed bin, flyash 1
6. Feeder, bin 1
discharge
7. Vibrator, feed bin 8
Weigh feeder,
flyash
Pneumatic conveying
system, Calcilox
10. Storage silo,
Calcilox
11. Feeder, discharge
Complete system with blower, cyclone
receiver, receiver filter, 200 hp motor,
28 tons/hr
82,000 ft3, 1,600 tons, field erected, 41 ft
dia, 62 ft high, carbon steel with top, 60°
cone bottom
Rotary airlock type, 28,000 Ib/hr, 9 in. dia
x 9 in. long, carbon steel
Electromechanical, rotary vibrators, 1 hp
motor
11,000 ft3, 19 ft dia, 38 ft high, with top,
60° cone bottom, carbon steel
Rotary airlock type, 9 in. dia, 9 in. long,
carbon steel
Electromechanical, rotary vibrators, 1 hp
motor
1 5 ft long, 24 in. belt, 2 hp motor, carbon
steel, 28 tons/hr
1 Complete system with blower, cyclone
receiver, receiver filter, 50 hp motor,
3 tons/hr
1 13,000 ft3, 550 tons, field erected, 19 ft
dia, 29 ft high, carbon steel with top, 60°
cone bottom
1 Rotary airlock type, 4,300 Ib/hr, 9 in. dia
x 9 in. long, carbon steel
12. Vibrator, Calcilox 8
storage silo
Electromechanical, rotary vibrators, 1 hp
motor
13. Feed bin, Calcilox 1 860 ftj, 9 ft dia x 18 ft high, with top,
60° cone bottom, carbon steel
(continued)
30
-------
TABLE 7 (continued)
Item
No.
Description
14. Feeder, discharge
15. Vibrator, feed bin 4
16. Weigh feeder,
Calcilox
Rotary airlock type, 4,300 Ib/hr, 9 in. dia
x 9 in. long, carbon steel
Electromechanical, rotary vibrators, 1 hp
motor
5 ft long, 12 in. belt, 1/3 hp motor, carbon
steel, 3 tons/hr
Area 2—Thickening
Item
No.
Description
1. Tank, thickener
feed
2. Agitator, thickener 1
feed
34,000 gal, field erected, 18 ft dia, 18 ft
high, open top, carbon steel, rubber lined
with four 18 in. x 18 ft baffles, offset
3-1/2 in. from wall
25 hp, 72 in. dia blade, rubber coated
3. Pump, thickener
feed
4. Thickener
5. Tank, thickener
overflow
6. Pump, thickener
overflow recycle
7. Pump, thickener
underflow to filter
8. Sump pump,
thickener tunnel
745 gpm, 75 ft head, rubber lined, 40 hp
motor
160 ft dia, 10 ft high, rubber lined
concrete basin with rake and motor
(1 spare motor)
8,000 gal, 12 ft dia, 10 ft high, carbon
steel, rubber lined with flat bottom
468 gpm, 75 ft head, rubber lined, 20 hp
motor
277 gpm, 75 ft head, rubber lined, 15 hp
motor
5 gpm, 10 ft head, carbon steel, 1/4 hp
motor
(continued)
31
-------
TABLE 7 (continued)
Area 3—Filtration
Item
No.
Description
1. Filter, rotary
drum
2. Pump, filtrate
recycle
3. Conveyor, hori-
zontal belt
4. Conveyor, sloping
belt
500 ft2 surface area, 12 ft dia, 14 ft long
drum, stainless steel (wetted parts), vacuum
and filtrate pumps included
146 gpm, 75 ft head, rubber lined, 15 hp
motor
52 tons/hr, 16 ft long, 24 in. belt,
100 ft/min, 3/4 hp
52 tons/hr, 30 ft long, 24 in. belt,
100 ft/min, 1 hp
Area 4—Mixing
Item
No.
Description
1. Mixer, pug mill 2
2. Conveyor, sloping 1
belt
81 tons/hr, 75 hp motor, carbon steel
81 tons/hr, 30 ft long, 25 ft rise, 24 in,
belt, 100 ft/min, 5 hp
Area 5—Storage
Item
No.
Description
1. Storage shed
2. Conveyor, hori-
zontal belt with
traveling tripper
Concrete pad with roof only, 150 ft long,
50 ft wide, 40 ft high
81 tons/hr, 150 ft long, 30 in. belt,
100 ft/min, 5 hp
(continued)
32
-------
TABLE 7 (continued)
Area 6—Disposal
Item
No.
Description
1. Wheel loader 1
2. Disposal trucks 3
3. Dozer 1
4. Scraper grader 1
5. Roller 1
6. Water tank truck 1
7. Pickup truck 1
Front-end wheel loader with 4.5 yd3 bucket
35 ton capacity, 13 yd-*, rear dump
Crawler dozer, 300 hp
11 yd3, 150 hp
4x4 sheeps foot, towed
6,000 gal
33
-------
TABLE 8. WASTE PRODUCED
CJ
Scrubber sludge - Ib/hr
Solids Water
Base case
Variations from base case
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
61,400
25,100
184,300
62,800
62,800
62,800
27,100
95,700
57,200
66,100
61,400
61,400
25,100
61,400
184,300
41,000
16,700
122,800
41,900
41,900
41,900
18,100
63,800
38,100
44,100
41,000
41,000
16,700
41,000
122,800
Flyash - Ib/hr
54,400
22,300
163,200
55,600
55,600
55,600
53,400
54,900
38,500
72 , 300
54,400
54,400
22,300
54,400
163,200
Calcilox lb/hra
4,300
1,800
12,900
4,400
4,400
4,400
1,900
6,700
4,000
4,600
4,300
4,300
1,800
4,300
12,900
Total - mine
T h /ViT- "/
156,800
64,100
470,300
160,300
160,300
160,300
98,600
214,400
133,800
182,500
156,800
156,800
64 , 100
156,800
470,300
disposal
74
74
74
74
74
74
82
70
72
76
74
74
74
74
74
Total - Dravo
Lb/hr %
161,100
65,900
483,200
164,700
164,700
164,700
100,500
221,100
137,800
187,800
161,100
161,100
65,900
161,100
483,200
landfill
solids
75
75
75
75
75
75
82
71
72
76
75
75
75
75
75
a. Dravo process only: 7Z Calcilox. based on srr,,hh01- <^i,-^
-------
limestone scrubber sludges of 53% to 80% solids and unspecified flyash
content. Hagerty and others (1977) evaluated samples of actual scrubber
sludge and sludge - flyash blends. They obtained dry bulk densities of
about 75 to 100 lb/ft3 (100 to 120 lb/ft3 wet bulk density) at optimum
moisture contents of about 15% to 30% using the standard Proctor test.
Coltharp and others (1979) evaluated a variety of sludge - flyash mix-
tures using sludges of different sulfite contents and flyash from different
coal types. They obtained dry bulk density results of 52 to 94 lb/ft3
at optimum moisture contents of 16% to 35%, with one exception of 65%.
High sulfite sludge - flyash blends of 50% each had dry bulk densities
of 70 to 89 lb/ft3 (92 to 111 lb/ft3 wet bulk density) at optimum moisture
contents of 25% to 35%.
The data illustrate, as the investigators themselves have emphasized,
the wide variations in bulk densities of FGD sludges, flyashes, and
sludge - flyash blends. The many variations of sludge type, flyash type
and content, and moisture content, as well as sampling and testing
methods, make extension of these data to other compositions difficult.
Site-specific factors will necessarily be important factors in determining
waste volumes for particular FGD waste disposal systems.
This study assumes a single waste wet bulk density of 97 lb/ft3
(1.55 g/cc) for both processes. This represents a dry bulk density of
77 lb/ft3 for the base-case mine disposal process and 78 lb/ft3 for the
base-case Dravo landfill process. The relationships of wet (yni) and
dry (yd) bulk densities and moisture content (w) are based on the ASTM
Method 698-70 relationship:
yd = [ym/(u + 100)] x 100
The waste quantities produced by the processes in this study are
shown in Table 9. No in-place compaction is assumed. Acreage requirements
are based on a 30-foot depth for the landfill process, in which earthmoving
equipment is used to pile and grade the fill, and a 5-foot depth for the
mine-disposal process, in which the waste'is simply dumped between the
spoil rows.
35
-------
TABLE 9. ANNUAL AND LIFETIME WASTE QUANTITIES AND DISPOSAL AREA REQUIREMENTS
OJ
01
Mine disposal
Acres/first year Acres/lifetime
Tuns/first year (5 ft depth) (5 ft depth)
Base case
Case variations
200 HW
1500 MW
25 years remaining life3
20 years remaining life
15 years remaining lifec
27, sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
7,000 hr/yr constant schedule
200 MW
500 MW
1500 MW
548,800
224,400
1,646,100
561,100
561,100
561,100
345,100
750,400
468,300
638,800
548, 8pO
548,800
224,400
548,800
1,646,100
52
21
156
53
53
53
33
• 71
44
61
52
52
21
52
156
947
386
2,838
702
436
247
595
1,293
807
1,102
947
947
636
1,560
4,674
Dravo landfill
Acres/first year
Tons/first year (30 ft depth)
563,900
230,700
1,691,200
576,500
576,500
576,500
351,800
7/3,900
482,300
654,900
563,900
563,900
230,700
563,900
1,691,200
8.9
3.6
26.7
9.1
9.1
9.1
5.6
12.2
7.6
10.3
8.9
8.9
3.6
8.9
26.7
Acres/lifetime
(30 ft depth)
162
66
486
120
75
42
101
222
139
188
162
162
109
267
800
Basis: 97 Ib/ft bulk density, wet waste, no in-place compaction.
127,500 hours except as noted. a. 92,500 lifetime hours.
lifetime hours.
First year based on 7,000 hours of operation. Lifetime operation
b. 57.500 lifetime hours. c. 32,500 lifetime hours. d. 210,000
-------
RESULTS
Capital investment and annual revenue requirements for the base
case and each case variation are shown in Appendix A. Table 10 shows a
summary of capital investments for the mine disposal and Dravo landfill
processes. Table 11 shows a summary of annual revenue requirements for
both processes.
The estimates reported in Appendix A and in the text are for waste
processing costs; they do not include either scrubber costs or ESP
costs. For comparison with complete FGC systems the following costs for
a limestone scrubber system without waste disposal facilities and for
ESP units can be combined with the disposal costs:
Capital investment Annual revenue requirements
Scrubber $36,368,000 $11,842,000
ESP system 9,614,000 1,975,000
The scrubber and ESP costs are based on a 500-MW power plant, using the
same design and economic premises that were used for the waste disposal
process evaluations.
In addition, the base cases of the two processes evaluated in this
study and the six processes previously evaluated (Barrier and others,
1978, 1979) are included in modular form.
BASE CASE
Capital investment for the base-case mine disposal process is
$7,996,000 (16.0 $/kW). Direct investment for process requirements is
42% of the total capital investment. Mobile equipment—consisting of
loaders, trucks, and a dozer—is 7% of the total. Land cost is insignifi-
cant. Including ESP costs of $9,614,000 the total capital investment is
$17,610,000 (35.2 $/kW).
Capital investment for the base-case Dravo landfill process is
$10,004,000 (20.0 $/kW). Direct investment for process requirements is
37% of the total capital investment. Mobile equipment is 8% of the
total and land is 6% of the total. Including ESP costs the total capital
investment is $19,618,000 (39.2 $/kW).
Annual revenue requirements for the mine disposal process are
$3,430,200 (0.98 mill/kWh). Direct costs, consisting entirely of con-
37
-------
TABLE 10. CAPITAL INVESTMENT SUMMARIES
MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
Mine disposal
Condition
Base case
Variations from base case
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
k$
7,996
5,917
16,306
8,067
8,067
8,067
7,056
9,161
7,422
8,589
8,554
8,846
5,917
7,996
16,308
$/kW
16.0
29.6
10.9
16.2
16.2
16.2
14.1
18.3
14.8
17.2
17.1
17.7
29.6
16.0
10.9
$/tona
0.80
1.46
0.55
1.09
1.75
3.10
1.12
0.67
0.8?
0.74
0.86
0.88
0.88
0.80
0.33
Dravo landfill
k$
10,004
7,180
20,632
9,960
9,793
9,677
8,586
11,923
9,302
10,749
10,573
10,843
7,330
10,392
21,783
$/kW
20.0
35.9
13.8
19.9
19.6
19.4
17.2
23.9
18.6
21.5
21.2
21.7
36.7
20.8
14.5
$/tona
0.97
1.71
0.67
1.31
2.07
3.6.?
1.34
0.85
1.06
0.90
1.03
1.06
1.74
1.01
0.71
a. Based on total dry solids,as disposed of, during the life of the
power plant.
TABLE 11. ANNUAL REVENUE REQUIREMENTS SUMMARIES
MINE DISPOSAL AND DRAVO LANDFILL PROCESSES
Condition
k$
Mine disposal
Mills/ $/ton
kWh waste3
$/ton
solids
Dravo landfill
k$
Mills/
kWh
$/ton
waste3
$/ton
solids
Base case
Variations from base case
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
3,430
2,508
6,336
3,523
3,562
3,679
2,938
3,974
3,294
3,604
4,128
4,545
2,508
3,430
6,336
0.98
1.79
0.60
1.01
1.02
1.05
0.84
1.14
0.94
1.03
1.18
1.30
] .79
0.98
0.60
6
11
3
6
6
6
8
5
7
5
7
8
11
6
3
.25
.18
.85
.28
.35
.56
.51
.30
.03
.64
.52
.28
.18
.25
.85
8.45
15.10
5.20
8.49
8.58
8.86
10.38
7.46
9.77
7.42
10.17
11.19
15.10
8.45
5.20
5
3
10
5
5
5
3
6
4
5
5
6
3
5
10
,032
,397
,322
,149
,179
,304
,910
,666
,7P9
,297
,735
,185
,410
,066
,421
1
2
0
1
1
1
1
1
1
1
1
]
2
1
0
.44
.43
.98
.47
.48
.52
.12
.90
.37
.51
.64
.77
.44
.45
.99
8.90
14.72
6.10
8.93
8.98
9.20
11.11
8.61
9.95
8.09
10.17
10.97
14.78
8.98
6.16
11.90
19.63
8.14
11.91
11.98
12.27
13.55
12.13
13.82
10.64
13.56
14.62
19.71
11.98
8.22
a. Wet waste, as disposed of, based on 7,000 hours of operation.
38
-------
version costs, account for 40% of the annual revenue requirements. The
largest element of direct costs is disposal labor, followed by process
labor. Maintenance, fuel, and utilities account for only 25% of direct
costs. The remaining 60% of annual revenue requirements consists of
indirect costs for capital charges and overheads based on capital
investment and direct costs. Including annual revenue requirements of
$1,975,000 for ESP operation, the annual revenue requirements for the
mine disposal process are $5,405,200 (1.54 mills/kWh).
Annual revenue requirements for the base-case Dravo landfill process
are $5,032,400 (1.44 mills/kWh). Direct costs for this process account
for 52% of the total. The cost of Calcilox® is the largest direct cost
element; it constitutes 37% of direct costs. Disposal labor and process
labor are the other large direct cost elements, together accounting for
46% of direct costs. Again, maintenance, fuel, and utilities constitute
a relatively minor portion of direct costs. Including ESP operation
annual revenue requirements for the Dravo landfill process are $7,007,100
(2.00 mills/kWh).
Both processes are labor intensive. The major portion of labor
costs is involved in handling and transporting the waste. Mine disposal,
which requires fewer man-hours at the disposal site, has lower disposal
labor costs ($595,700 compared to $744,600 for the Dravo landfill process).
Labor requirements for loading and transportation, which are identical
for both processes, account for the major portion of disposal labor
costs, however. Consequently, the savings in disposal labor requirements
by mine disposal are relatively minor. The greatest difference in costs
between the two processes is the cost of raw material, which accounts
for 60% of the difference in annual revenue requirements between the two
processes.
In terms of waste quantities, the mine disposal process annual
revenue requirements are 6.3 $/ton of wet waste, as disposed of at 74%
solids, and 8.5 $/ton of dry solids. The Dravo landfill annual revenue
requirements are 8.9 $/ton of 75% solids wet waste and 11.9 $/ton of dry
solids. Including ESP costs the mine disposal costs are 9.9 $/ton of
wet waste and 13.3 $/ton of dry solids. With ESP costs the Dravo landfill
process costs are 12.4 $/ton of wet waste and 16.6 $/ton of dry solids.
CASE VARIATIONS
Case variations for both processes were calculated to evaluate the
effect of different conditions on costs. A constant 7000 hr/yr operating
profile, power plant size and age, coal sulfur and ash content, and dis-
tance to the disposal site were evaluated. The effects of case variations,
as a percentage change from the base case in $/kW and mills/kWh, are
shown in Table 12.
39
-------
TABLE 12. EFFECT OF CASE VARIATIONS ON UNIT COSTS,
RELATIVE TO BASE-CASE COSTS
Percent change from base case3
Case variation
200 MW
1500 MW
25 years remaining life
20 years remaining life
15 years remaining life
2% sulfur in coal
5% sulfur in coal
12% ash in coal
20% ash in coal
5 miles to disposal
10 miles to disposal
200 MW, constant load
500 MW, constant load
1500 MW, constant load
Mine
Capital
investment
+85
-32
+ 1
+ 1
+ 1
-12
+11
- 8
+ 8
+ 7
+11
+85
0
-32
disposal
Annual revenue
requirements0
+83
-39
+ 3
+ 4
+ 7
-14
+16
- 4
+ 5
+20
+33
+83
0
-39
Dravo
Capital
investment
+80
-31
- 1
- 2
- 3
-14
+19
- 7
+ 8
+ 8
+ 9
+84
+ 4
-28
landfill
Annual revenue
requirements0
+69
-32
+ 2
+ 3
+ 6
-22
+32
- 5
+ 5
+14
+23
+69
+ i
-31
a.
Base case is 500-MW, new (30-year life), 3.5% sulfur, 16% ash, 1 mile to
disposal.
b. Percent difference in $/kW.
c. Percent difference in mills/kWh.
40
-------
Power Plant Size and Operating Schedule
Declining-Load Operating Schedule—
Power plant size variations of 200- and 1500-MW were evaluated
using the same declining-load operating schedule used for the 500-MW
base case. Capital investment for both processes at the three power
plant sizes is shown in Table 13. Annual revenue requirements are shown
in Table 14. The same data are summarized graphically in Figure 7.
The data illustrate the decline in unit disposal costs with increas-
ing power plant capacity. Capital investment for the mine disposal
process is 29.6 $/kW for the 200-MW power plant size. It decreases to
16.0 and 10.9 $/kW for the 500- and 1500-MW power plants. Similarly,
capital investment for the Dravo landfill process is 35.9 $/kW for the
200-MW power plant and decreases to 20.0 and 13.8 $/kW for the 500- and
1500-MW power plants.
In terms of percentage increase in total capital investment from
200- to 500- to 1500-MW power plant sizes, using the 200-MW size as the
basis, the capital investments increase 35% and 175% for the mine disposal
process and 39% and 187% for the Dravo landfill process. On the same
basis power output increases 150% and 650%.
A similar relationship occurs in annual revenue requirements. The
mine disposal process annual revenue requirements are 1.79 mills/kWh for
the 200-MW power plant, 0.98 mill/kWh for the 500-MW power plant, and
0.60 mill/kWh for the 1500-MW power plant. The Dravo landfill process
annual revenue requirements are 2.43 mills/kWh for the 200-MW power
plant, 1.44 mills/kWh for the 500-MW power plant, and 0.98 mill/kWh for
the 1500-MW power plant.
In terms of percentage increase in total annual revenue require-
ments, again using the 200-MW size as a basis, the mine disposal process
annual revenue requirements increase 37% and 153% and the Dravo landfill
process annual revenue requirements increase 48% and 204% for power
output increases of 150% and 650%.
The economy of scale realized in both capital investment and annual
revenue requirements is largely the result of general economies in
process equipment, mobile equipment, labor, and related indirect costs.
The Dravo landfill process has a slightly larger percentage increase in
capital investment with size because of disposal-area land requirements,
which increase linearly with waste volume, and thus with power plant
output. The considerably larger percentage increase in annual revenue
requirements with power plant size for the Dravo landfill process is
largely a result of the raw material costs, which also increase linearly
with power plant size.
Mine disposal, regardless of the process used to produce the waste,
has a minor advantage in economy of scale through elimination of disposal-
area land requirements. This advantage would, of course, be diminished
or eliminated by fees to the operator or leasers if the fees were related
41
-------
TABLE 13. POWER PLANT SIZE VARIATION, DECLINING LOAD,
CAPITAL INVESTMENT
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Mine
200 MW
1,211
117
122
40
284
52
504
2,330
35
2,365
476
2,841
288
72
511
212
3,924
785
4,709
423
565
5,697
11
209
5,917
29.6
disposal,
500 MW
1,985
139
242
53
345
56
504
3,324
50
3,374
559
3,933
322
81
686
272
5,294
1,059
6,353
579
762
7,694
14
288
7,966
16.0
, k$
1500 MW
4,152
214
1,264
85
540
80
954
7,289
109
7,398
1,104
8,502
438
110
1,316
488
10,854
2,171
13,025
1,192
1,563
15,780
28
498
16,306
10.9
Dravo
200 MW
1,320
126
132
44
300
56
564
2,542
38
2,580
707
3,287
392
98
549
237
4,563
913
5,476
477
657
6,610
242
328
7,180
35.9
landfill
500 MW
2,161
151
264
58
367
60
654
3,715
56
3,771
790
4.561
426
107
752
301
6,147
1,229
7,376
659
885
8,920
581
523
10,004
20.0
, k$
1500 MW
4,498
234
1,389
95
579
87
1,404
8,286
124
8,410
1,335
9,745
438
109
1,464
542
12,298
2,460
14,758
1,342
1.771
17,871
1,729
1,032
20,632
13.8
Basis
ISIS
New midwestern plant with 30-year, 127,500-hour Ife and 9,000 Btu/kWh heat rate; 3.5% sulfur,
16% ash, 10,500 Btu/lb coal; 1.5 stoichiometry limestone scrubbing and ESP flyash collection
to NSPS; 15% solids slurry dewatered to 60% solids, blended with flyash, and trucked 1 mile
to surface mine; mid-1979 cost basis.
42
-------
TABLE 14. POWER PLANT SIZE VARIATIONS, DECLINING LOAD,
ANNUAL REVENUE REQUIREMENTS
Mine disposal. k$ Dravo landfill. k$
200 MW 500 MW 1500 MW 200 MW 500 MW 1500 MW
Direct Costs
Delivered raw materials
Calcilox 403 966 2.893
Total raw material costs 403 966 2,893
Conversion costs
Operating labor and supervision
Plant 329 438 548 329 438 548
Disposal equipment 447 596 1,042 596 745 1,191
Plant maintenance - 4Z of
direct investment 114 157 340 131 182 390
Landfill operation
Landfill preparation 6 15 45
Truck fuel and maintenance 14 33 99 14 34 102
Earthmovlng equipment fuel
and maintenance 27 66 198 37 90 271
Electricity 55 77 162 72 108 224
Analyses 1_7 1J 2£ 17 17 26
Total conversion costs 1.002 1.383 2,414 1,201 1,629 2.796
Total direct costs 1,002 1,383 2,414 1,605 2,595 5,688
Indirect Costs
Capital charges
Depreciation, interim replacement.
and Insurance at 7.83Z of total
depreciable Investment 446 602 1,236 518 698 1,399
Average cost of capital and taxes
at 8.6* of total capital investment 509 688 1,402 618 860 1,774
Overhead
Plant, 50% of conversion costs less
electricity 473 653 1,126 565 761 1,286
Administrative, 10% of total labor
and supervision 78 103 159 92 118 174
Total indirect costs • 1.506 2,047 3,923 1,792 2,437 4,634
Total annual revenue requirements 2.508 3,430 6,336 3,397 5,032 10,322
Equivalent unit revenue requirements
Mllls/kWh 1.79 0.98 0.60 2.43 1.44 0.98
$/ton waste 11.2 6.3 3.9 14.7 8.9 6.1
$/ton dry solids 15.1 8.5 5.2 19.6 11.9 8.1
Basis
One-year, 7,000-hour operation of systems described in capital investment summary; mid-1980
cost basis.
43
-------
40 -
f\
H
H
w
u
P-i
30
20
10
Mine
disposal
I I I I I I I I I I I I I
200
500
1500
to
H
£5
W
o-
w
W
W
£
2.5 ~
2.0
1.5
1.0
0.5
Mine
disposal
I i i i I I I U_J 1—I 1 I |_L
200
500
POWER PLANT SIZE, MW
1500
Figure 7. Effect of power plant size on disposal costs.
44
-------
to waste volume. The mine disposal process evaluated in this study has
a more significant advantage in economy of scale because it requires no
purchased raw materials whose quantities are linearly related to waste
volume.
Constant-Load Operating Schedule—
A constant-load operating schedule of 7,000 hr/yr for 30 years
(210,000 lifetime operating hours, compared to 127,500 hours for the
declining-load schedule) was evaluated for the three power plant sizes.
The effect on both capital investment and first-year annual revenue
requirements is negligible as shown in Table 15. The only capital
investment cost element significantly affected is disposal-area land
requirements. First-year annual revenue requirements are affected by
increased indirect costs.
TABLE 15. CONSTANT LOAD VERSUS DECLINING LOAD
Mine disposal, k$
Capital
investment
Dravo landfill, k$
Annual revenue
requirements5
Capital
investment
Annual revenue
requirements5
Constant Load
200 MW
500 MW
1500 MW
5,917
7,996
16,308
2,508
3,430
6,336
7,330
10,392
21,783
3,410
5,066
10,421
Declining Loadc
200 MW
500 MW
1500 MW
5,917
7,996
16,308
2,508
3,430
3,336
7,180
10,004
20,632
3,397
5,032
10,322
a. Based on 7,000 hr/yr operation.
b. 210,000 lifetime operating hours.
c. 127,500 lifetime operating hours.
Power Plant Remaining Life
In addition to the base-case new power plant with a 30-year remaining
life, existing power plants with remaining lives of 25, 20, and 15 years
were evaluated. These are shown below, compared to the base case, and
graphically in Figure 8.
45
-------
H
H
-------
Remaining life, years
30 25 20 15
Mine disposal
Capital investment, k$ 7,996 8,067 8,067 8,067
Annual revenue requirement, k$ 3,430 3,523 3,562 3,679
Dravo landfill
Capital investment, k$ 10,004 9,960 9,793 9,677
Annual revenue requirement, k$ 5,032 5,149 5,179 5,304
Power plant age has little effect on either capital investment or
annual revenue requirements. Capital investment is affected by increased
process equipment costs resulting from the higher heat rate. In addition,
the Dravo landfill process capital investment is reduced by the reduction
in disposal-area land requirements. The result is an increase in capital
investment for the mine disposal process of about 1% and a maximum
decrease in capital investment of 3% for the Dravo landfill process.
Annual revenue requirements are increased a maximum of 7% for the
mine disposal process and a maximum of 5% for the Dravo landfill process.
The increases are a result of slight increases in raw material (for the
Dravo landfill process) and conversion costs, but primarily they are a
result of increased indirect costs. Capital charges, particularly
depreciation, interim replacement and insurance, account for the major
increase in annual revenue requirements.
Sulfur in Coal
Coal sulfur contents of 2.0% and 5.0% were evaluated in addition to
the base-case 3.5% sulfur coal. Coal sulfur content has a considerable
influence on both capital investment and annual revenue requirements
because of its effect on process equipment size, raw material requirements,
and disposal costs. The mine disposal process, with neither raw material
nor disposal-area land requirements, is less economically sensitive to
coal sulfur content.
Capital investment is primarily affected by process equipment and
(for the Dravo landfill process) disposal area land requirements as
shown below and in Figure 9. Mobile equipment costs are relatively
insensitive to coal sulfur content because of the highly incremental
nature of the equipment requirements.
Sulfur in coal, wt % dry 2.0 3.5 5.0
k$ $/kW k$ $/kW k$ $/kW
Mine disposal
Process equipment 1,532 3.1 1,985 4.0 2,465 4.9
Mobile equipment 559 1.1 559 1.1 642 1.3
Total capital investment 7,056 14.1 7,996 16.0 9,161 18.3
Dravo landfill
Process equipment 1,665 3.3 2,161 4.3 2,700 5.4
Mobile equipment 790 1.6 790 1.6 873 1.7
Land 364 0.7 581 1.2 795 1.6
Total capital investment 8,586 17.2 10,004 20.0 11,923 23.9
47
-------
H
5S
W
CO
W
40
30
20
10
Dravo landfill
Mine disposal
V!
CO
CO
H
sz
W
S
W
o-
w
w
td
>
W
2.5
a 2.0
1.5
1.0
0.5
Dravo landfill
Mine disposal
I
I
I
12 345
SULFUR IN COAL, %
Figure 9. Effect of coal sulfur content on disposal costs,
48
-------
The annual revenue requirement direct costs most affected by coal
sulfur content are raw material, disposal labor and supervision, and
mobile equipment operating costs. Of these, raw material cost for the
Dravo landfill process has the largest effect on total costs. Disposal
labor and supervision increases considerably with increasing coal sulfur
content because of increased trucking requirements. Mobile equipment
fuel and maintenance costs have large increases but do not constitute as
large a part of annual revenue requirements. Process operating labor
and supervision cost is not affected.
Sulfur in coal, wt % dry 2.0 3.5 5.0
k$ Mills/kWh k$ Mills/kWh k$ Mills/kWh
Mine disposal
Disposal labor 447 0.13 596 0.17 745 0.21
Mobile equipment 62 0.02 99 0.03 135 0.04
Total annual revenue
requirements 2,938 0.84 3,430 0.98 3,974 1.14
Dravo landfill
Raw materials 429 0.12 966 0.28 1,504 0.43
Disposal labor 596 0.17 745 0.21 894 0.26
Mobile equipment 77 0.02 124 0.04 161 0.05
Total annual revenue
requirements 3,910 1.12 5,032 1.44 6,666 1.90
Ash in Coal
Coal ash contents of 12% and 20% were evaluated in addition to the
16% ash base-case coal. Coal ash content has a moderate effect on
capital investment and annual revenue requirements. As in the case of
coal sulfur content the primary effect on capital investment direct
costs is on process equipment, mobile equipment, and disposal-area land
requirement costs. These are shown below and the totals are shown
graphically in Figure 10.
Ash in coal, wt % 12 16_ 20
k$ $/kW k$ $/kW k$ $/kW
Mine disposal
Process equipment 1,788 3.6 1,985 4.0 2,173 4.3
Mobile equipment 559 1.1 559 1.1 642 1.3
Total capital investment 7,422 14.8 7,996 16.0 8,589 17.2
Dravo landfill
Process equipment 1,939 3.9 2,161 4.3 2,343 4.7
Mobile equipment 790 1.6 790 1.6 873 1.7
Land 497 1.0 581 1.2 676 1.4
Total capital investment 9,302 18.6 10,004 20.0 10,749 21.5
-------
H
I—i
CL,
<
U
40
30
« 20
10
12
Dravo landfill
Mine disposal
16
20
PC
en
2.5
S 2.0
r.
CO
1.5
o-
w
w
w
1.0
0.5
O
12
Dravo landfill
Mine disposal
I
16
ASH IN COAL, %
-o—
20
Figure 10. Effect of coal ash content on disposal costs.
50
-------
k$
1,354
3,294
896
1,591
Mills /kWh
0.39
0.94
0.26
0.45
k$
1,383
3,430
966
1,629
Mills/kWh
0.40
0.98
0.28
0.47
k$
1,446
3,604
1,030
1,696
Mills/kWh
0.41
1.03
0.29
0.48
Annual revenue requirements are affected by a modest increase in
conversion costs (process maintenance, mobile equipment fuel and mainte-
nance, and electricity). In addition, the Dravo landfill process has an
increase in raw material costs because of the decreasing heat content of
the coal as the ash content increases. More coal is burned, producing
more FGD waste upon which the raw material consumption is based. There
is no increase in labor and supervision costs.
Ash in coal, wt % 12 16 20
Mine disposal
Conversion
Total annual revenue
requirements
Dravo landfill
Raw materials
Conversion
Total annual revenue
requirements 4,799 1.37 5,032 1.44 5,297 1.51
Distance to the Disposal Site
Distances of 5 and 10 miles to the disposal site were evaluated in
addition to the base-case 1-mile distance. The only direct costs affected
by distance are capital investment mobile equipment cost and annual
revenue requirements disposal labor and supervision and truck fuel and
maintenace.
Capital investment, shown below and in Figure 11, is little affected
because of the minor portion composing mobile equipment costs.
Distance to disposal site 1 mile 5 miles 10 miles
k$ $/kW k$ $/kW k$ $/kW
Mine disposal
Mobile equipment 559 1.1 890 1.8 1,055 2.1
Total capital investment 7,996 16.0 8,554 17.1 8,846 17.7
Dravo landfill
Mobile equipment 790 1.6 1,121 2.2 1,286 2.6
Total capital investment 10,004 20.0 10,573 21.2 10,843 21.7
Annual revenue requirements, shown below and in Figure 11, are more
affected. Mine disposal annual revenue requirements increase 20% for
the 5-mile distance and 34% for the 10-mile distance, as compared to the
base case. The Dravo landfill increases are 15% and 24% for the same
distances. The increase is a result of greatly increased disposal labor
for truck operation and truck fuel and maintenance costs.
51
-------
40
3
w
3
H
h-1
Pn
U
30
20
10
W
Pi
w
Pi
w
3
z
w
>
w
2.5
2.0
1.5
1.0
0.5
Dravo landfill
Mine disposal
J I I I I
Dravo landfill
I I I I
I I
J L
I I
DISTANCE TO DISPOSAL SITE, MILES
10
10
Figure 11. Effect of distance to disposal site on disposal
costs.
52
-------
Distance to disposal site 1 mile 5 miles 10 miles
k$ Mills/kWh k$ Mills/kWh k$ Mills/kWh
Mine disposal
Disposal labor 596 0.17 894 0.26 1,042 0.30
Trucks 33 0.01 110 0.03 214 0.06
Total annual revenue
requirements 3,430 0.98 4,128 1.18 4,545 1.30
Dravo landfill
Disposal labor 745 0.21 1,042 0.30 1,191 0.34
Trucks 34 0.01 113 0.03 220 0.06
Total annual revenue
requirements 5,032 1.44 5,735 1.64 6,185 1.77
MODULAR COST COMPARISONS
Cost breakdowns of the base cases by processing areas were made to
facilitate identification of cost elements and comparison of different
disposal processes. In addition to the mine disposal and Dravo landfill
processes evaluated in this study, the six processes previously evaluated
(Barrier and others, 1978, 1979) are also included in this comparison.
Schematic flow diagrams are shown in Figure 12. Although evaluated over
a 2-year period all of the processes are based on the same design and
economic premises and the costs are projected to the same time period.
All of the disposal costs are for both flyash and FGD waste. The flyash
is either removed simultaneously with S02 in the scrubber or is collected
separately and used in the FGD waste treatment process. Flyash is
collected in the scrubber simultaneous with the sulfur oxides for
processes not using dry flyash because of the design premises in use at
the time of the earlier two studies. The six processes from the previous
evaluations consist of two ponding processes and four landfill processes.
In the untreated ponding process (Tables 16 and 17) the 15% solids
slurry from the absorbers, consisting of simultaneously collected flyash
and sulfur salts, is collected in an agitated 63,000-gallon pond feed
tank from which it is pumped to the pond. Excess water is pumped back
into the FGD system. The material balance for the ponding process
consists of 772,000 Ib/hr of 15% solids feed to the pond, a return water
rate of 540,000 Ib/hr, and 232,000 Ib/hr of 50% solids settled sludge at
a specific gravity of 1.45.
The Dravo ponding process (Tables 18 and 19) is based on the Dravo
Lime Company fixation process which uses Calcilox and lime as additives.
In this variation the 15% solids slurry, consisting of simultaneously
collected flyash and sulfur salts, is thickened to 35% solids and mixed
with 7% Calcilox and 1% lime, both percentages based on total slurry
solids. The treated sludge is then pumped to the pond where it is
assumed to settle to a solids content of 50% and solidify over a period
of about 20 days. The same pond design and recycle water system is used
as is used for the untreated ponding process. In addition to the thickener
and mix tank, the process includes equipment for unloading, storing, and
metering the Calcilox and lime. The overall material balance consists
of 772,000 Ib/hr of sludge to the thickener.; 331,000 Ib/hr of sludge,
53
-------
UNTREATED PONDING
DRAVO PONDING
IUCS
THICKENER
FILTER
MIXER
LANDFILL
CHEMFIX
THICKENER
CEMENT
FILTER
to
1
SILICATE
MIXER
— /
SLUDGE -FLYASH BLENDING ^
THICKENER
FILTER
— to
MIXER
LANDFILL
GYPSUM
AIR
OXIDATION
THICKENER
FILTER
-^
*
LANDFILL
—| MINE |~
DRAVO LANDFILL
LANDFILL
Figure 12. Process flow diagrams.
54
-------
TABLE 16. MODULAR CAPITAL INVESTMENT - PONDING
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage , building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
Costs by area, k$
Raw
material Thickening Filtration Mixing Storage
37
35
2
21
115
53
263
3
266
266
80
11
51
31
439
88
527
53
63
643
14
60
717
1.4
Disposal
91
86
1,109
5
52
280
1,623
25
1,648
7,251
8,899
287
38
1,051
486
10,761
2,152
12,913
566
1,550
15,029
1,409
56
16,494
33.0
Total
128
121
1,109
7
73
395
53
1,886
28
1,914
7,251
9,165
367
49
1,102
517
11,200
2,240
13,440
619
1.613
15,672
1,423
116
17,211
34.4
Basis: Base-case conditions; 15% solids slurry from simultaneous flyash and SOX removal in the scrubber
pumped directly to the pond; pond water is recycled; 116,000 Ib/hr solids in waste.
55
-------
TABLE 17. MODULAR ANNUAL REVENUE REQUIREMENTS - PONDING
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
Costs by area, k$
Raw
material Thickening Filtration Mixing Storage
170,800
54,900
3,100
8,500
237,300
237,300
40,600
60,300
117,100
17,100
235,100
472,400
0.14
0.2
1.2
Disposal
48,200
21,700
217,500
52,200
339,600
339,600
899,700
1,419,800
143,700
4,800
2,468,000
2,807,600
0.80
1.0
6.9
Total
219,000
76,600
217,500
55 , 300
8,500
576,900
576,900
940,300
1 ,480,100
260,800
21 ,900
2,703,100
3,280,000
0.94
1.2
8.1
56
-------
TABLE 18. MODULAR CAPITAL INVESTMENT - DRAVO PONDING
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Elect rical
Inst rumen t at ion
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
Raw
material
636
165
197
34
614
71
81
1,798
46
1,844
1,844
339
67
434
97
2,781
556
3,337
334
400
4,071
5
_4M
4,522
9.0
Costs by area, k$
Thickening Filtration Mixing Storage Disposal
1,545
58
69
83
214
25
28
2,022
16
2,038
2,038
180
35
479
107
2,839
568
3,407
340
409
4,156
10
33
4,199
8.4
46
10
13
3
39
5
6
122
3
125
125
11
2
29
7
174
35
209
21
25
255
1
11
267
0.5
45
29
657
34
44
107
12
928
8
936
7,410
8,346
291
58
685
438
9,818
1,963
11,781
437
1,414
13,632
1,434
60
15,126
30.3
Total
2,272
262
657
313
164
974
113
115
4,870
73
4,943
7,410
12,353
821
162
1,627
649
15,612
3,122
18,734
1,132
2,248
22,114
1,450
550
24,114
48.2
Basis: Base-case conditions; 35X solids thickened waste from simultaneous flyash and SOX removal in the
scrubber is treated with lime and Calcilox and pumped to the disposal pond; pond water is recycled;
125,000 Ib/hr solids in waste.
57
-------
TABLE 19. MODULAR ANNUAL REVENUE REQUIREMENTS - DRAVO PONDING
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Raw
49,800
10,700
461,000
2,301,400
Costs by area, k$
material Thickening Filtration Mixing Storage Disposal Total
1,840,400
275,900 96,400
124,600 43,500
18,600
3,700
162,200
162,200
17,500
7,900
11,000
2.600
39,000
39,000
1,840,400
48,200 438,000
21,700 197,700
222,300 222,300
24,300 103,700
17,000
316,500 978,700
316,500 2,819,100
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
244,300
388,900
205,600
27.600
3,167,800
0.91
2.6
7.2
249,400
361,100
71,800
9.60.0
866,400 691,900
854,100
0.24
0.7
2.0
15,300
23,000
14,000
1.800
54,100
93,100
0.03
0.1
0.3
817,800 1,326,800
1,300,800 2,073,800
146,100
4.800
437,500
... 43.800
2,269,500 3,881,900
2,586,000 6,701,000
0.74 1-91
2.1
5.9
5.5
15.3
58
-------
8,100 Ib/hr of Calcilox, and 1,160 Ib/hr of lime to the mix tank; 347,000
Ib/hr of 36% solids sludge to the pond; and 97,000 Ib/hr of recycle pond
water.
The IU Conversion Systems, Inc. (IUCS) fixation process (Tables 20
and 21) produces a soillike material that is transported to the disposal
site as a solid and disposed of in a landfill. The fixative is 4% lime,
based on total slurry solids. The 15% solids slurry from the absorbers,
consisting of simultaneously collected flyash and sulfur salts, is
thickened to 35% solids, filtered to 60% solids on rotary drum filters,
blended with the lime in blade-type mixers, and conveyed to a storage
pile. The waste is then loaded into dump trucks with a front loader and
hauled to the landfill site. The slurry feed rate is 772,000 Ib/hr, the
lime feed rate is 4,600 Ib/hr, and 198,000 Ib/hr of waste is produced.
The Chemfix process (Tables 22 and 23) differs from the other
landfill processes in that the filtration and mixing facilities are
situated at the disposal site. The 35% solids thickened sludge, con-
sisting of simultaneously collected flyash and sulfur salts, is pumped
to the disposal site. It is filtered to 60% solids and blended with
6.9% portland cement and 1.8% sodium silicate, based on total solids.
The waste is then distributed in the landfill using scrapers. The
slurry feed rate is 772,000 Ib/hr, the cement and silicate feed rates
are 8,000 and 2,100 Ib/hr, and 203,000 Ib/hr of waste is produced.
In the sludge - flyash blending process (Tables 24 and 25) the
flyash is collected separately by an ESP, the absorber sludge is dewatered
by thickening and filtration to 60% solids, and the two are blended in a
blade-type mixer. The waste is then trucked to the landfill. The
flyash from the ESP units is handled pneumatically and metered to the
mixer using a weigh feeder in the same manner as the fixative additives.
The slurry feed is 410,000 Ib/hr, the flyash feed is 54,000 Ib/hr, and
157,000 Ib/hr of waste is produced.
In contrast to the other landfill processes, the gypsum process
(Tables 26 and 27) uses the superior dewatering characteristics of high-
sulfate sludges rather than additives to produce a landfill material.
The scrubber slurry system is modified to provide for forced-air oxida-
tion sufficient to produce a 15% solids slurry in which 95% of the
sulfur is in the form of gypsum. The slurry, consisting of simultaneously
collected flyash and sulfur salts, is thickened to 35% solids and filtered
to 80% solids on rotary filters. The waste is then trucked to the
landfill. The slurry feed rate is 756,000 Ib/hr and 142,000 Ib/hr of
waste is produced.
The mine disposal process is shown in Tables 28 and 29 and the
Dravo landfill process is shown in Tables 30 and 31.
Waste Quantities
Table 32 shows the amount of waste disposed of and the land require-
ments for the disposal area. Although the quantity of both flyash and
59
-------
TABLE 20. MODULAR CAPITAL INVESTMENT - IUCS PROCESS
Costs by area, k$
Raw
material Thickening
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
In s t rument a t ion
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
383
55
42
36
198
22
171
907
20
927
927
95
24
181
61
1,288
258
1,546
155
186
1,887
5
213
2,105
4.2
1,556
54
42
36
198
22
170
2,078
20
2,098
2,098
181
45
409
138
2,871
573
3,444
344
412
4,200
5
44
4,249
8.5
Filtration
510
49
38
32
179
19
154
981
18
999
999
91
23
195
65
1,373
275
1,648
165
198
2,011
4
40
2,055
4.1
Mixing Storage Disposal Total
102
18
14
11
64
7
55
271
6
277
277
25
6
54
18
380
76
456
46
55
557
2
16
575
1.1
2,551
176
136
115
639
70
550
4,237
64
4,301
581 581
581 4,882
392
98
839
38 320
619 6,531
124 1.306
743 7,837
16 726
89 940
848 9,503
660 676
225 538
1,733 10,717
3.5 21.4
Basis: Base-case conditions; 60% solids thickened and filtered waste from simultaneous flyash and SOX
removal in the scrubber is mixed with lime and trucked to the disposal site; 120,000 Ib/hr solids
in waste.
60
-------
TABLE 21. MODULAR ANNUAL REVENUE REQUIREMENTS - IUCS PROCESS
Costs by area, $
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
Raw
material
859,400
135,800
53,300
47,100
5,300
241,500
1,100,900
147,700
181,000
97,200
13,600
439.500
1,540,400
0.44
2.2
3.7
Thickening
135,800
53,300
24,600
5 , 300
219,000
219,000
328,900
365,400
97,200
13.600
805,100
1,024,100
0.29
1.5
2.4
Filtration
122,600
48,200
18,200
4,700
193,700
193,700
157,500
176,700
87,700
12.300
434.200
627,900
0.18
0.9
1.5
Mixing
43,800
17,200
17,100
1,700
79,800
79,800
43,600
49,500
31,400
4.400
128.900
208,700
0.06
0.3
0.5
Storage Disposal
893,500
11,000
41,600
110,900
1,057,000
1,057,000
66,400
149,100
528,500
89,300
833,300
1,890,300
0.54
2.7
4.5
Total
859,400
438,000
893,500
172,000
11,000
41,600
110,900
107,000
17,000
1,791,000
2,650,400
744,100
921,700
842,000
133,200
2,641,000
5,291,400
1.51
7.6
12.6
61
-------
TABLE 22. MODULAR CAPITAL INVESTMENT - CHEHFIX PROCESS
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
Raw
material
521
109
100
78
409
51
264
1,532
23
1,555
1,555
156
39
354
96
2,200
440
2,640
265
317
3,222
5
488
3,715
7.4
Thickening
1,579
55
50
39
205
26
132
2,086
31
2,117
2,117
186
47
422
132
2,904
581
3,485
350
418
4,253
5
37
4,295
8.7
Costs
Filtration
523
52
48
37
196
25
126
1,007
15
1,022
1,022
97
24
220
63
1,426
2»5
1,711
171
205
2,087
3
34
2,124
4.2
by area. k$
Mixing Storage Disposal
262
11
11
8
43
5
28
368
6
374
374
33
8
76
23
514
103
617
62
74
753
1
9
763
1.5
697
697
10
707
442
1,149
71
1,220
244
1,464
100
176
1,740
679
215
2,634
5.3
Total
2,885
227
697
209
162
853
107
550
5,690
85
5,775
442
6,217
472
118
1,072
385
8,264
1 653
9,917
948
1,190
12,055
693
783
13,531
27.1
Basis: Base-case conditions; 603! solids waste from simultaneous flyash and SOX removal in the scrubber is
mixed with portland cement and sodium silicate and trucked to the disposal site; 125,800 Ib/hr
solids in waste.
62
-------
TABLE 23. MODULAR ANNUAL REVENUE REQUIREMENTS - CHEMFIX PROCESS
Costs by area, $
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
Raw
material
2,177,000
210,300
90,400
33,100
8,200
342,000
2,519,000
252,300
319,500
154,500
21,000
747,300
3,266,300
0.94
4.5
7.4
Thickening
105,100
51,600
19,600
4,100
180,400
180,400
333,000
369,400
80,400
10,500
793,300
973,700
0.28
1.4
2.2
Filtration
100,700
45,700
15,000
3,900
165,300
165,300
163,400
182,700
75,200
10,100
431,400
596,700
0.17
0.8
1.4
Mixing
21,900
10,700
11,000
800
44,400
44,400
59,000
65,600
16,700
2.200
143,500
187,900
0.05
0.3
0.4
Storage Disposal
744,600
32,600
11,000
213,200
24,300
1,025,700
1,025,700
136,200
226,500
500,600
74,500
937,800
1,963,500
0.56
2.8
4.5
Total
2,177,000
438,000
744,600
231,000
11,000
213,200
103,000
17,000
1,757,800
3,934,800
943,900
1,163,700
827,400
118,300
3,053,300
6,988,100
2.00
9.8
15.9
63
-------
TABLE 24. MODULAR CAPITAL INVESTMENT - SLUDGE - FLYASH BLENDING
Costs by area. k$
Process equipment
Piping and Insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
Raw
material
495
53
92
20
159
21
192
1,032
19
1,051
1,051
104
26
214
73
1,468
293
1,761
176
211
2,148
5
53
2,206
4.4
Thickening
1,101
47
82
18
59
19
171
1,497
17
1,514
1,514
150
38
308
105
2,115
423
2,538
254
305
3,097
5
45
3,147
6.3
Filtration
333
24
41
9
79
10
86
582
9
591
591
59
14
120
41
825
165
990
99
119
1,208
2
24
1,234
2.5
Mixing Storage Disposal Total
56
15
27
6
48
6
55
213
5
218
218
21
5
44
15
303
61
364
36
44
444
2
16
462
0.9
1,985
139
242
53
345
56
504
3,324
50
3,374
581 581
581 3,955
334
83
686
39 273
620 5,331
124 1,066
744 6,397
17 582
89 768
850 7,747
522 536
184 322
1,556 8,605
3.1 17.2
Basis: Base-case conditions; 607, soils thickened and filtered FGD waste is blended with dry flyash and
trucked to the disposal site; 116,000 Ib/hr solids in waste. ESP costs of $9,614,000 not shown.
64
-------
TABLE 25. MODULAR ANNUAL REVENUE REQUIREMENTS -
SLUDGE - FLYASH BLENDING
Costs by area, ?
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
Raw
material
166,400
60,100
35,400
6,400
268,300
268,300
168,200
189,700
116,400
16,600
490,900
759,200
0.22
1.4
1.9
Thickening
148,900
53,800
13,100
5,800
221,600
221,600
242,400
270,700
104,200
14,900
632,200
853,800
0.24
1.6
2.1
Filtration
74,500
26,900
18,400
2,900
122,700
122,700
94,600
106,100
52,200
7,500
260,400
383,100
0.11
0.7
0.9
Mixing
48,200
17,400
10,000
1,900
77,500
77,500
34,800
39,700
33,800
4,800
113,100
190,600
0.05
0.3
0.5
Storage Disposal
744,600
8,700
32,900
87,800
874,000
874,000
66,600
133,800
437,000
74,500
711,900
1,585,900
0.45
2.9
3.9
Total
438,000
744,600
158,200
8,700
32,900
87,800
76,900
17,000
1,564,100
1,564,100
606,600
740,000
743,600
118,300
2,208,500
3,772,600
1.08
6.9
9. j
Note: ESP annual revenue requirements of $1,975,000 not shown.
65
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TABLE 26. MODULAR CAPITAL INVESTMENT - GYPSUM
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kU
Raw
material Thickening
686
117
17
28
147
35
117
1,147
18
1,165
1,165
131
32
285
90
1,703
341
2,044
204
245
2,493
8
81
2,582
5.2
Costs by area, k$
Filtration Mixing Storage
493
57
8
14
73
17
57
719
9
728
728
64
16
140
57
1,005
201
1,206
121
145
1,472
4
42
1,518
3.0
Disposal Total
1,179
174
25
42
220
52
174
1,866
27
1,893
498 498
498 2,391
195
48
425
39 186
537 3,245
107 649
644 3,894
15 340
77 467
736 4,701
391 403
184 307
1,311 5,411
2.6 10.8
Basis: Base-case conditions; waste from simultaneous removal of flyash and SOX in the scrubber is oxidized
to 95% sulfate by forced-air oxidation. Oxidized waste is thickened and filtered to 80% solids and
trucked to the disposal site; 113,000 Ib/hr solids in waste. Additional scrubber costs for air
oxidation of 52,303,000 not shown.
66
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TABLE 27. MODULAR ANNUAL REVENUE REQUIREMENTS - GYPSUM
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Raw
Costs by area, $
material Thickening Filtration Mixing Storage Disposal Total
293,500
64,100
20,300
11,400
389,300
389,300
144,500
31,500
29,000
5,600
744,600
6,600
29,800
79,400
438,000
744,600
95,600
6,600
29,800
79,400
49,300
17,000
860,400 1,460,300
860,400 1,460,300
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
195,200
222,100
184,500
29,400
631,200
1,020,500
0.29
2.1
2.6
115,300
130,500
90,800
14,400
351,000
561,600
0.16
1.1
1.4
57,600
112,700
430,200
74,500
675,000
1,535,400
0.44
3.1
3.8
368,100
465,300
705,500
118.300
1,657,200
3,117,500
0.89
6.3
7.9
Note: Scrubber modifications for air oxidation annual revenue requirements of $1,005,000 not shown.
67
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TABLE 28. MODULAR CAPITAL INVESTMENT - MINE DISPOSAL
Costs by area, kS
Raw
material Thickening Filtration
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Subtotal
Total fixed investment
Allowance for startup
Subtotal capital investment
Land
Total capital investment
$/kW
495
53
92
20
159
21
192
1,032
19
1,051
1,051
100
25
214
72
1,462
293
1,755
159
210
2,124
5
54
2,183
4.4
1,101
47
82
18
59
19
171
1,497
17
1,514
1,514
145
36
308
105
2,108
420
2,528
231
303
3,062
5
46
3,113
6.2
333
24
41
9
79
10
86
582
9
591
591
57
15
120
41
824
165
989
90
119
1,198
2
24
1,224
2.5
Mixing Storage Disposal Total
56
15
27
6
48
6
55
213
5
218
218
20
5
44
15
302
61
363
33
44
440
2
16
458
0.9
1,985
139
242
53
345
56
504
3,324
50
3,374
559 559
559 3,933
322
686
39 272
598 5,294
120 l.iP59
718 6,353
66 579
86 762
870 7,694
14
148 288
1,018 7,996
2.0 16.0
Basis: Base-case conditions; 60% solids thickened and filtered waste from the FGD system is blended with
dry flyash and trucked to a surface mine; 116,000 Ib/hr solids In waste. ESP costs of $9,614,000
not shown.
68
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TABLE 29. MODULAR ANNUAL REVENUE REQUIREMENTS - MINE DISPOSAL
Costs by area, $ ^^^^^
Raw
material Thickening Filtration Mixing Storage Disposal Total
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
166,400
59,700
35,400
6.400
267,900
267,900
166,300
187,700
116,300
16.600
486,900
754,800
0.22
1.3
1.8
148,900
53,400
13,100
5.800
221,200
221,200
239,700
267,700
104,100
14.900
626,400
847,600
0.24
1.5
2.0
74,500
26,600
17,700
2.900
121,700
121,700
93,800
105,300
52,000
7.500
258,600
380,300
0.11
0.7
0.9
48,200
17,300
10,700
1.900
78,100
78,100
34,500
39,400
33,700
4.800
112,400
190,500
0.05
0.3
0.5
595,700
32,900
65,900
694,500
694,500
68,100
87,600
347,200
59.600
562,500
1,257,000
0.36
2.2
3.0
438,000
595,700
157,000
32,900
65,900
76,900
17.000
1,383,400
1,383,400
602,400
687,700
653,300
103.400
2,046,800
3,430,200
0.98
6.0
8.2
Note: ESP annual revenue requirements of $1,975,000 not shown.
69
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TABLE 30. MODULAR CAPITAL INVESTMENT - DRAVO LANDFILL
Costs by area, k$
Process equipment
Piping and insulation
Transport lines
Foundation and structural
Site preparation
Electrical
Instrumentation
Process buildings
Storage building
Subtotal
Services and miscellaneous
Total
Pond construction
Total direct investment
Engineering design and supervision
Architect and engineering
Construction expense
Contractor fees
Subtotal
Contingency
Total fixed investment
Allowance for startup
Interest during construction
Subtotal capital investment
Land
Working capital
Total capital investment
$/kW
Raw
material
588
75
132
28
184
29
257
1,293
20
1,313
1,313
213
53
263
87
1,929
389
2,318
231
278
2,827
6
251
3,084
6.2
Thickening
1,093
40
68
15
95
16
136
1,463
21
1,484
1,484
111
28
295
98
2,016
403
2,419
242
291
2,952
3
36
2,991
6.0
Filtration
330
20
35
8
47
8
71
519
8
527
527
55
14
105
35
736
148
884
88
106
1,078
1
20
1,099
2.2
Mixing
56
12
21
5
30
5
40
169
3
172
172
34
9
35
12
262
52
314
31
37
382
1
12
395
0.8
Storage
94
4
8
2
11
2
150
271
4
275
275
13
3
54
18
363
72
435
44
52
531
1
4
536
1.1
Disposal Total
2,161
151
264
58
367
60
504
150
3,715
56
3,771
790 790
790 4,561
426
107
752
51 301
841 6,147
165 1.22?
1,006 7,376
23 659
121 885
1,150 8,920
569 581
180 503
1,899 10,004
3.8 20.0
Basis: Base-case conditions; 60% solids thickened and filtered waste from the FGD system is blended with
dry flyash and Calcilox and trucked to the disposal site; 120,000 Ib/hr solids in waste. ESP costs
of $9,614,000 not shown.
70
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TABLE 31. MODULAR ANNUAL REVENUE REQUIREMENTS - DRAVO LANDFILL
- - - - - — -
Costs by area, $
Direct Costs
Total raw materials
Conversion
Operating manpower
Disposal manpower
Process maintenance
Disposal operations
Land preparation
Trucks
Earthmoving equipment
Pond maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
Indirect Costs
Capital charges
Depreciation, interim replace-
ment, and insurance
Cost of capital and taxes
Overhead
Plant
Administration
Total indirect costs
Total annual revenue
requirements
Mills/kWh equivalent
$/ton wet sludge
$/ton dry sludge
Raw
material
966,400
219,000
91,000
55,000
8,500
373,500
1,339,900
221,400
265,200
159,300
21,900
667,800
2,007,700
0.57
3.5
4.7
Thickening
113,900
47,300
16,300
4,400
181,900
181,900
231,100
257,200
82,800
11,400
582,500
764,400
0.22
1.4
1.8
Filtration
56,900
23,600
22,700
2,200
105,400
105,400
84,400
94,500
41,400
5.700
226,000
331,400
0.10
0.6
0.8
Mixing
35,000
14,600
11,800
1,400
62,800
62,800
29,900
34,000
25,500
3.500
92,900
155,700
0.05
0.3
0.4
Storage
13,200
5,500
2,100
500
21,300
21,300
41,600
46,100
9,600
1 .300
98,600
119,900 1
0.03
0.2
0.3
Disposal
744,600
15,100
33,800
90,200
883,700
883,700
90,000
163,300
441,800
74,500
769,600
,653,300
0.47
2.9
3.9
Total
966,400
438,000
744,600
182,000
15,100
33,800
90,200
107,900
17,000
1,628,600
2,595,000
698,400
860,300
760,400
118.300
2,437,400
5,032,400
1.44
8.9
U .9
Note: ESP annual revenue requirements of $1,975,000 not shown.
71
-------
sulfur is the same in all cases, the weights, and particularly the
volumes, vary considerably. For the nongypsum processes, the largest
contributor to the weight and volume differences is the amount of water
in the waste, which varies from 50% to 25% of the total weight. Density
differences (90 lb/ft3 for the ponded waste and 97 lb/ft3 for the landfill
material) contribute less. The gypsum process has both the lowest
weight and lowest volume of waste. The low weight is a result of the
improved limestone utilization with the additional forced-air oxidation.
At the stoichiometries used, the gypsum process uses 48,000 tons/yr less
limestone, which appears in the other processes as unreacted absorbent.
This more than compensates for the 38,000 tons/yr larger weight of
sulfur salts (95% CaS04«2H20 instead of 15%) in the gypsum process
waste. The difference in waste volume is even more pronounced because
of the higher bulk density and lower water content of the gypsum waste.
At a density of 121 lb/ft3 and 80% solids it occupies only 45% of the
volume occupied by the settled untreated ponding waste and 72% of the
volume of the landfilled blended sludge and flyash. The differences in
volume between the gypsum waste and the fixed waste are more pronounced
depending on the quantities of fixatives in the waste.
The differences in solid waste quantities are reflected in disposal
costs although not to the same degree as they appear in weight and
volume comparisons. This is largely a result of the incremental nature
of the costs involved. Within broad ranges the same amount of earth-
moving equipment and number of trucks are needed for a range of waste
quantities. In general, the same quantity of earthmoving equipment is
needed whether the waste is high sulfite or gypsum.
Base-Case Modular Cost Comparisons
The sludge - flyash blending process, the mine disposal process, and
the Dravo landfill process require inclusion of ESP costs for comparison
with the other processes. Using the same premise basis, ESP capital
investment is $9,614,000 (19.2 $/kW) and annual revenue requirements are
$1,975,000 (0.56 mill/kWh). For similar comparisons air-oxidation
scrubber modification costs are included in the gypsum process costs.
Capital investment for air-oxidation modifications is $2,303,000 (4.6
$/kW) and annual revenue requirements are $1,005,000 (0.29 mill/kWh).
In those cases in which flyash is collected separately the cost of
ESP units and their operation is a major component of the waste disposal
costs. The capital investment for separate flyash removal is about one-
half of the sludge - flyash blending, mine disposal, and Dravo landfill
processes capital investments. In annual revenue requirements separate
flyash collection accounts for 28% to 36% of the total for these three
processes. In comparison, simultaneous flyash removal results in relatively
modest increases in thickening and filtration costs.
Separate collection of flyash is, of course, possible with all of
the processes evaluated and would require similar costs for all processes.
In comparison of landfill processes with separate flyash collection,
cost differences would largely be reduced to cost differences in the raw
material portion of the cost breakdown.
72
-------
The raw material costs include the cost of purchased raw materials,
their handling, and the handling of separately collected flyash. For
the processes using purchased fixatives raw materials are an important
element of both capital investment and annual revenue requirements. Fly-
ash handling is also a relatively expensive element (4.5 $/kW in capital
investment and 0.22 mill/kWh in annual revenue requirements). The
advantage of a single fixative is illustrated by comparison of raw
material costs for the Dravo ponding and Chemfix processes, which use
two additives, with the IUCS process which uses one. The IUCS process
has raw material capital investment and annual revenue requirements
about one-half those of the others.
Thickening is the largest capital investment cost element, excluding
ESP costs, for all of the nonponding processes. It is also a large cost
element in annual revenue requirements. The gypsum process, with a more
rapidly settling high-sulfate sludge, has a major advantage over the
other processes in thickening capital investment but little in thicken-
ing annual revenue requirements.
Filtration is also a large cost element, though considerably less
so than thickening. Both capital investment and annual revenue require-
ments for filtration are roughly one-half those for thickening. Filtra-
tion costs for the gypsum process are lower than the other simultaneous
flyash-FGD waste filtration processes because of the superior filtration
characteristics of the high-sulfate sludge. Filtration costs are lowest,
however, for the processes in which only FGD waste is filtered. Mixing
costs are a minor part of both capital investment and annual revenue
requirements.
Transportation and disposal site costs illustrate fundamental
differences between ponding and solid waste disposal methods. Capital
investment for ponding transportation and disposal site costs is an
order of magnitude greater than the capital investment for landfill
transportation and disposal site operations. Pond construction accounts
for 80% of the untreated ponding direct costs and 60% of the Dravo
ponding process direct costs. Capital investment for transport lines is
also an important element, accounting for 12% of the untreated ponding
capital investment direct costs and 5% of the Dravo ponding capital
investment direct costs. For the Chemfix process, in which the thickened
sludge is pumped to the disposal site for further treatment, the cost of
transport lines is not offset by the minor savings in mobile equipment.
(Scrapers distribute the waste on the site and trucks are not used.)
Mobile equipment capital investment is 0.9 $/kW for the Chemfix process,
however, compared with 1.2 $/kW for the IUCS process. In addition, the
Chemfix process requires an additional 1.4 $/kW for transport lines.
Disposal land costs for both ponding processes are two to nearly four
times greater than those for landfill processes. As a percentage of
total capital investment, however, disposal land costs for all the
processes (excluding mine disposal which has none) are similar, ranging
from 8% for untreated ponding to 5% for the Chemfix process.
73
-------
Among the landfill and mine disposal processes, transportation and
disposal site costs are a relatively minor element of total capital
investment. Direct capital investment consists of mobile equipment
costs. Land cost is the only other major capital investment cost element.
Both of these costs are a minor part of total capital investment in all
the processes evaluated. Mine disposal, with reduced equipment and no
disposal land requirements, has the lowest capital investment in this
area. The gypsum process, with the smallest waste volume, has a lower
transportation and disposal site capital investment than the other
landfill processes.
Annual revenue requirements for ponding transportation and disposal
site costs are also higher than those for landfill and mine disposal
although the differences are less pronounced. About two-thirds of the
annual revenue requirement direct costs for ponding transportation and
disposal site operations consist of pond maintenance. Transportation of
the waste is a relatively minor cost element. In contrast, about four-
fifths of the annual revenue requirements direct cost for landfill and
mine disposal transportation and disposal site operations is for labor
and supervision, much of it for mobile equipment operation.
Capital Investment Comparisons
In overall comparison of the processes evaluated, the most important
capital investment cost elements are separate flyash collection, raw
material handling, thickening, and pond construction. Untreated ponding,
with almost all of the capital investment in transportation and pond
costs, has a capital investment of 34.4 $/kW. Dravo ponding, which
combines high raw material costs for two additives, thickening costs,
and pond costs, has the highest capital investment, 48.2 $/kW. Among
landfill fixation processes the Dravo landfill process has the highest
capital investment, 39.4 $/kW, almost half of which is ESP costs for
separate flyash collection.
Sludge - flyash blending has a capital investment of 36.4 $/kW and
mine disposal has a capital investment of 35.3 $/kW. Both costs include
the 19.2 $/kW cost of ESP units for separate flyash removal. The reduction
in mobile equipment and land requirements effected by use of the mine as
a disposal site accounts for the difference in capital costs between the
two processes.
The IUCS process, with one fixative, has a capital investment of
21.4 $/kW. The Chemfix process, with two fixatives, has a capital
investment of 27.1 $/kW. The difference is largely in raw material
handling costs as a result of the additional fixative. However, addi-
tional costs for transportation of the waste also occur because the
waste is processed at the disposal site. A similar effect in raw material
costs is seen in the two-fixative Dravo ponding process.
The gypsum process has a capital investment of 15.4 $/kW. The
considerably lower capital investment is a result of a cost of only 4.6
74
-------
$/kW for the necessary scrubber modifications, improved thickening and
filtration characteristics, and a reduction in transportation and disposal
site costs.
Annual Revenue Requirements Comparison
Large cost elements in annual revenue requirements are separate
flyash collection, raw material purchase and handling, and disposal.
Untreated ponding has the lowest annual revenue requirements, 0.94
mill/kWh, almost all of them for transportation and disposal site operations.
The Dravo landfill process (with costs for both separate flyash collection
and a fixative) and the Chemfix process (with costs for two fixatives
and higher transportation costs) both have annual revenue requirements
of 2.00 mills/kWh. Dravo ponding, with two fixatives and ponding costs,
but no ESP and filtration costs, has annual revenue requirements of 1.91
mills/kWh. The IUCS process, with one fixative, has annual revenue
requirements of 1.51 mills/kWh, the lowest of the fixation processes.
If dry flyash were used in the IUCS process, however, it would be similar
in cost to the other fixation processes.
The sludge - flyash blending and mine disposal processes have
annual revenue requirements of 1.64 and 1.54 mills/kWh respectively.
The largest cost element in both is ESP costs. The difference is a
result of reduced disposal site costs and lower indirect costs based on
capital investment.
The gypsum process annual revenue requirements are 1.18 mills/kWh,
second only to ponding. The low cost is a result of relatively modest
additional costs for air oxidation, the absence of raw material and
mixing costs, and lower transportation and disposal site costs than
other landfill processes.
75
-------
CONCLUSIONS
In comparison with the Dravo landfill process, mine disposal is
approximately one-fifth lower in capital investment and one-third lower
in annual revenue requirements. The cost differences are largely a
result of additional costs for purchase and handling of Calcilox."
Reduced disposal costs for the mine disposal process account for a small
reduction in capital investment and annual revenue requirements.
Cost reductions directly associated with mine disposal are a result
of reductions in land and mobile equipment requirements and reduced
disposal labor and mobile equipment operating costs. The costs associated
with the use of a fixative lie largely in purchase of Calcilox and instal-
lation of equipment for handling it. Because the quantity used is small
relative to the wastes, processing and disposal costs are not greatly
affected. ESP costs are a large part of the total FGC costs for both
processes.
Other large capital investment cost elements for both processes are
raw materials handling (which includes flyash) and thickening. Labor
and supervision costs, particularly for disposal operations, are the
largest direct cost element in annual revenue requirements. Disposal
operations, consisting of fuel, maintenance, and land preparation for
the Dravo landfill process, are minor costs. Utility costs are also
minor.
CASE VARIATIONS
Power plant size has the largest effect on costs of the case vari-
ations studied. The differences are largely the result of economy of
scale, particularly in process equipment. The largest effect in annual
revenue requirement direct costs is a result of lower labor and super-
vision costs, relative to plant size, at the larger power plant sizes.
The effect of power plant size on the Dravo landfill process annual
revenue requirements is less pronounced because it has costs linearly
related to waste quantities, particularly raw materials and disposal
land, which the mine disposal process does not have.
Coal sulfur content produces large differences in the capital
investments and annual revenue requirements for both processes. The
variations are greater for the Dravo landfill process because of the
effects of disposal-area land requirements and raw material require-
ments, which are not factors in the mine disposal process.
76
-------
Coal ash content also had an important effect on capital investment
and annual revenue requirements, although less than coal sulfur content
in the ranges evaluated. The effect of ash content is essentially the
same for both processes.
Distance to the disposal site is essentially a measure of the
effects of variations in trucking costs on capital investment and annual
revenue requirements. The increased distances produce a moderate
increase in capital investment and a large increase in annual revenue
requirements for both processes. The results indicate that hauling
distance is an important consideration. Mine disposal is an economically
favorable disposal option in comparison to on-site disposal only for the
more favorable circumstances of mine location. For the five-mile dis-
tance to the disposal site the increase in trucking costs eliminate the
cost savings associated with mine disposal instead of on-site landfill.
MODULAR COST COMPARISONS
Breakdown of costs into modular processing areas for the eight
processes evaluated in this and the two previous studies illustrates the
effect of various process functions. ESP costs, for processes in which
flyash is collected separately, are a large part of both capital invest-
ment and annual revenue requirements. Excluding ESP costs, raw material
purchase and handling, thickening capital investment, and pond capital
investment are high-cost areas.
Raw material costs are also an important part of annual revenue
requirements when purchased fixatives are used. The use of more than
one fixative compounds the costs in these areas because they are almost
completely additive. Flyash handling, although larger in volume, is not
greatly higher in cost than purchased fixative handling, partially as a
result of reduced storage facilities.
Thickening is a large element in capital investment and important
in annual revenue requirements. Filtration is less costly in both.
Mixing is a minor part of both capital investment and annual revenue
requirements.
Capital investment for transport lines and pond construction is an
order of magnitude greater than mobile equipment and landfill-site capital
investment.
In comparison of the seven processes for high-sulfite waste» ponding
is shown to be a low-cost disposal option, if practical, if there is no
treatment of the sludge. Treatment and fixation before ponding add the
high-cost processing areas without materially reducing pond costs.
Landfill processes, excluding ESP costs, are lower in capital investment
than ponding processes. This advantage is reduced when purchased fixa-
tives are used, particularly if two are used. Landfill annual revenue
requirements are only competitive with ponding if no purchased fixatives
are used.
77
-------
The gypsum process results illustrate the large decrease in capital
costs attainable by improvement in the dewatering characteristics of the
waste. The additional costs for air oxidation increase the annual
revenue requirements about one-fourth. Annual revenue requirements for
the gypsum process are thus intermediate between untreated ponding or
landfill without fixation and the landfill fixation processes.
78
-------
RECOMMENDATIONS
This study and the two previous studies summarized in the analysis
of modular costs illustrate cost spectrums for a number of waste-disposal
methods. The results suggest that certain cost-sensitive areas, such as
thickening and filtration, may be studied from a functional viewpoint,
as modular components applicable to several processes to more clearly
delinate cost differences between processes. Transportation and disposal-
area operations are also important cost factors, many elements of which
are independent of particular processes. Transportation alternatives
should particularly be investigated in greater variety and with emphasis
on energy requirement costs. Landfill preparation and operation should
be investigated with emphasis on definition of additional costs for site
investigations, pollution control, and monitoring costs associated with
existing and pending legislation. The effects of legislation such as
the Resources Conservation and Recovery Act should always be kept in
perspective.
In addition, the rapidly increasing information on waste chemical
and physical characteristics and on evolving technologies such as the
gypsum process should be incorporated into development of the conceptual
designs upon which the economic evaluations are based. More accurate
and detailed data on waste characteristics such as dewatering capa-
bilities, bulk densities, and handling characteristics would greatly
improve delineation of cost differences between disposal processes.
Technological changes in evolving processes could radically alter their
cost relationship to more defined processes.
79
-------
REFERENCES
Averitt, P., 1975. Coal Resources of the United States, January 1,
1974. Bull. 1412, U.S. Geological Survey, U.S. Government Printing
Office, Washington, D.C.
Barrier, J. W., H. L. Faucett, and L. J. Henson, 1978. Economics of
Disposal of Lime/Limestone Scrubbing Wastes: Untreated and Chemically
Treated Wastes. Bull. Y-123, U.S. Tennessee Valley Authority, Muscle
Shoals, Ala.; EPA-600/7-78-023a, U.S. Environmental Protection Agency,
Washington, D.C.
Barrier, J. W., H. L. Faucett, and L. J. Henson, 1979. Economics of
Disposal of Lime/Limestone Scrubbing Wastes: Sludge/Flyash Blending and
Gypsum Systems. Bull. Y-140, U.S. Tennessee Valley Authority, Muscle
Shoals, Ala.; EPA-600/7-79-069, U.S. Environmental Protection Agency,
Washington, D.C.
Chaput, L. S., 1976. Federal Standards of Performance for New Station-
ary Sources of Air Pollution - A Summary of Regulations. Jour. Air
Pollution Association, Vol. 26, No. 11, pp. 1050-1060.
Chemical Engineering, 1974-76. Economic Indicators. Chem. Engr. Vol.
81, 82, 83 (all issues).
Chironis, N.P., 1978. Regional Aspects Affect Planning of Surface
Mining Operations. In: Coal Age Operating Handbook of Coal Surface
Mining and Reclamation, N. P. Chironis, ed., McGraw-Hill, N.Y., pp. 3-21.
Coal Age, 1978. Specialized Stripping Techniques. In: Coal Age Oper-
ating Handbook of Coal Surface Mining and Reclamation, N. P. Chironis,
ed., McGraw-Hill, N.Y., pp. 71-136.
Coltharp, W. M., N. P. Meserole, B. F. Jones, K. Schwitzgebel, R. S.
Merrill, G. L. Sellman, C. M. Thompson, and D. A. Malish, 1979. Chemical/
Physical Stability of Flue Gas Cleaning Wastes. FP-671, Vol. 2, Electric
Power Research Institute, Palo Alto, Calif.
Duvel, W. A., Jr., D. M. Golden, and R. G. Knight, 1979. Sulfur Dioxide
Scrubber Sludge—What Options Are Still Available? Preprint, presented
at the 5th EPA Symposium on FGD, Las Vegas, Nev.
Duvel, W. A., Jr., W. R. Gallagher, R. G. Knight, C. R. Kolarz, and R.
J. McLaren, 1978. State-of-the-Art of FGD Sludge Fixation. EPRI
FP-671, Vol. 3, Electric Power Research Institute, Palo Alto, Calif.
80
-------
Fling, R. B., W. M. Graven, P. P. Leo, and J. Rossoff, 1978. Disposal
of Flue Gas Cleaning Wastes: EPA Shawnee Field Evaluation - Second
Annual Report. EPA-600/7-78-024, U.S. Environmental Protection Agency,
Washington, B.C.
Griffith, E. D., 1979. Coal in Transition: 1985-2000. Min. Cong.
Jour., Vol. 65, No. 2, pp. 29-33.
Hagerty, D. J., C. R. Ullrich, and B. K. Thacker, 1977. Engineering
Properties of FGD Sludges. In: Proceedings of the Conference on
Geotechnical Practice for Disposal of Solid Waste Materials, Ann Arbor,
Mich., American Society of Civil Engineers, N.Y., pp. 23-40.
Hayes, E. T., 1979. Energy Resources Available to the United States,
1985 to 2000. Science, Vol. 203, No. 4377, pp. 233-239.
Jackson, D., 1978. Outstanding Surface Mines and Their Operation. In:
Coal Age Operating Handbook of Coal Surface Mining and Reclamation,
N. P. Chironis, ed., McGraw-Hill, N.Y., pp. 343-414.
Kelly, W., 1979. Evaluation of the Environmental Effects of Western
Surface Coal Mining, Volume II: Mine Inventory. EPA-600/7-79-034, U.S.
Environmental Protection Agency, Washington, D.C.
Kidder, Peabody & Co., 1978. Status Report on Fossil Boilers as of June
30, 1978. Research Department, Kidder, Peabody & Co.
Laseke, B. A., and T. W. Devitt, 1979. Status of Flue Gas Desulfuriza-
tion in the United States. Preprint, presented at the 5th EPA Symposium
on FGD, Las Vegas, Nev.
Leo, P. P. , and J. Rossoff, 1976. Control of Waste and Water Pollution
from Power Plant Flue Gas Cleaning Systems: First Annual R&D Report.
EPA-600/7-76-018, U.S. Environmental Protection Agency, Washington, D.C.
Leo, P. P., and J. Rossoff, 1978a, Controlling S02 Emissions from Coal-
fired Steam-Electric Generators: Solid Waste Impact (Volume II. Techni-
cal Discussion). EPA-600/7-78-044b, U.S. Environmental Protection
Agency, Washington, D.C.
Leo, P. P., and J. Rossoff, 1978b, Control of Waste and Water Pollution
from Coal-Fired Power Plants: Second R&D Report. EPA-600/7-78-224,
U.S. Environmental Protection Agency, Washington, D.C.
Lunt, R. R., C. B. Cooper, S. L. Johnson, J. E. Oberholtzer, G. R.
Schimke, and W. I. Watson, 1977. An Evaluation of the Disposal of Flue
Gas Desulfurization Wastes in Mines and the Ocean: Initial Assessment.
EPA-600/7-77-051, U.S. Environmental Protection Agency, Washington, D.C.
Manz, 0. E., and H. A. Gullicks, 1979. Disposal of High Alkaline Fly
Ash in a Decoaled Mine Seam. In: Proceedings of the 5th International
Ash Utilization Symposium, Atlanta, Ga., National Ash Association,
Washington, D.C. (unpaged)
81
-------
Peters, M. S., and K. D. Timmerhaus, 1968. Plant Design and Economics
for Chemical Engineers. McGraw-Hill, N.Y.
Popper, H., 1970. Modern Cost Engineering Technique. McGraw-Hill, N.Y.
Santhanam, C. J., R. R. Lunt, and C. B. Cooper, 1979. Current Alterna-
tives for Flue Gas Desulfurization (FGD) Waste Disposal - An Assessment.
Preprint, presented at the 5th EPA Symposium on FGD, Las Vegas, Nev.
Theis, T. L., J. L. Wirth, R. 0. Richter, and J. J. Marley, 1977.
Sorptive Characteristics of Heavy Metals in Fly Ash-Soil Environments.
In: Proceedings of the 31st Industrial Waste Conference, May 1976,
Purdue University, Ann Arbor Science Publishers, Ann Arbor, Mich., pp.
312-324.
Todd, D. G., 1979. Surface Mining Regulations and Litigation for 1978.
Min. Cong. Jour. Vol. 65, No. 2, pp. 45-50.
Westerstrom, L. W., 1976. Bituminous Coal and Lignite. In: Mineral
Facts and Problems, Bull. 667, U.S. Bureau of Mines, U.S. Government
Printing Office, Washington, B.C., pp. 157-172.
Westerstrom, L. W., and R. E. Harris, 1977. Coal - Bituminous and
Lignite. In: Minerals Yearbook, 1975, Vol. 1, U.S. Department of the
Interior, U.S. Government Printing Office, Washington, D.C.
82
-------
APPENDIX A
CAPITAL INVESTMENT AND ANNUAL REVENUE REQUIREMENT TABLES
83
-------
TABLE A-l. MINE DISPOSAL
CAPITAL INVESTMENT
(Base case)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
7,694
14
288
7,996
16.0
of total
1,985
139
242
53
345
56
504
3,324
50
3,374
559
3,933
322
81
686
272
5,294
1,05_9
6,353
579
762
24.8
1.7
3.0
0.7
4.3
0.7
6.3
41.6
0.6
42.2
7.0
49.2
4.0
1.0
8.6
3.4
66.2
13.2
79.5
7.2
9.5
96.2
0.2
3.6
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000 Btu/kWh
heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5 stoichiometry
limestone scrubbing and EbP fly ash collection to NSPS; 15% solids slurry
dewatered to 60% solids, blended with fly ash, and trucked 1 mile to
surface mine; mid-1979 cost basis.
84
-------
TABLE A-2. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(Base case)
Annual quantity Cost,
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35
35
548
548
2,652
1
,080
,080
,800
,800
,800
,000
man-hr
man-hr
tons
tons
kWh
hr
12
17
0
0
0
17
$/unit
.50
.00
,06
.12
.029
.00
Annual revenue
requirements, $
438,
595,
157,
32,
65,
76,
17,
1,383,
1,383,
000
700
000
900
900
900
000
400
400
% of
12
17
4
1
1
2
0
40
total
.8
.4
.6
.0
.9
.2
.5
.3
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.60% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
0.98
6.25
602,400
687,700
653,300
103,400
2,046,800
3,430,200
17.6
20.0
19.0
3.0
59.7
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
85
-------
TABLE A-3. MINE DISPOSAL
CAPITAL INVESTMENT
(200 MW)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Capital investment,
k$
1,21]
117
122
40
284
52
504
2,330
35
2,365
476
2,841
288
72
511
212
3,924
785
4,709
423
565
% of total
20.5
2.0
2.1
0.7
4.8
0.9
8.5
39.4
0.6
40.0
8.0
48.0
4.9
1.2
8.6
3.6
66.3
13.3
79.6
7.1
9.5
Total depreciable investment 5,697
96.3
Land H 0-2
Working capital 209 3 5
Total capital investment r 017
$/kW 5£j
Basis
New 200-MW midwestern plant with 30-year, 127,500-hour life and 9,200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
86
-------
TABLE A-4. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(200 MW)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
26,280 man-hr 12.50
26,280 man-hr 17.00
224,400 tons 0.06
224,400 tons 0.12
1,788,500 kWh 0.031
1,000 hr 17.00
328,500
446,800
114,000
13,500
26,900
55,400
17,000
1,002,100
1,002,100
13.1
17.8
4.5
0.5
1.1
2.2
0.7
40.0
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
1.79
$/ton waste
11.18'
446,100
508,900
473,400
77,500
1,505,900
2,508,000
17.8
20.3
18.9
3.1
60.0
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
87
-------
TABLE A-5. MINE DISPOSAL
CAPITAL INVESTMENT
(1500 MW)
Capital investment ,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
4,152
214
1,264
85
540
80
954
7,289
109
7,398
1,104
8,502
438
110
1,316
488
10,854
2,17j.
13,025
1,192
1 , 563
15,780
28
498
16,306
10.9
% of total
25.5
1.3
7.8
0.5
3.3
0.5
5.9
44.7
0.7
45.4
6.8
52.1
2.7
0.7
8.1
3.0
66.6
13.3
79.9
7.3
9,6
96.8
0.2
3.0
• •
Basis
10 j-o
New 1,500-MW midwestern plant with 30-year, 127,500-hour life and 9 000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5 '
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS- 157
solids slurry dewatered to 60% solids, blended with fly ash, and trucked"
1 mile to surface mine; mid-1979 cost basis.
88
-------
TABLE A-6. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(1500 MW)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthraoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
A3,800 man-hr 12.50
61,320 man-hr 17.00
1,646,100 tons 0.06
1,646,100 tons 0.12
5,994,900 kWh 0.027
1,500 hr 17.00
547,500
1,042,400
340,000
98,800
197,500
161,900
25,500
2,413,600
2,413,600
8.6
16.5
5.4
1.6
3.1
2.5
0.4
38.1
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total Indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
0.60
3.85
1,235,600
1,402,300
1,125,900
159,000
3,922,800
6,336,400
19.5
22.1
17.8
2.5
61.9
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
89
-------
TABLE A-7. MINE DISPOSAL
CAPITAL INVESTMENT
(25 years remaining life)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,026
140
239
53
345
56
504
3,363
50
3,413
559
3,972
322
81
693
274
5,342
1,068
6,410
585
769
7,764
14
289
8,067
16.2
% of total
25.1
1.7
3.0
0.7
4.3
0.7
6.2
41.7
0.6
42.3
6.9
49.2
4.0
1.0
8.6
3.4
66.2
13.2
79.5
7.3
9.5
96.2
0.2
3.6
Basis
Existing 500-MW midwestern plant with 25-year, 92,500-hour life and 9,200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
90
-------
TABLE A-8. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(25 years remaining life)
Annual quantity Cost,
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% oi
direct investment
Mine disposal operation
Truck fuel and maintenance
Karthmovinn equipment fuel
and maintenance
El ect ricity
Analyses
Total conversion costs
Total direct costs
35
35
561
561
2,652
1
,040
,040
,100
,100
,300
,000
man-hr
man-hr
tons
tons
kWh
hr
12.
17.
0.
0.
0
17
$/unit
50
.00
.06
. 12
.029
.00
Annual revenue
requirements, $
438
595
159
33
67
76
1_7
1,387
1,387
,000
,700
,000
,700
,300
,900
,000
,600
,600
% of
12
16
4
1
1
2
_0
39
total
.4
.9
.5
.0
.9
.2
J>
.4
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 8.80% of total
depreciable investment
Average cost of capita] and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Mills/kWh $/ton waste
Equivalent unit revenue requirements 1.01 6.28
683,200 19.4
693,800 19.7
655,400 18.6
103,400 2.9
2,135,800 60.6
3,523,400
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
91
-------
TABLE A-9. MINE DISPOSAL
CAPITAL INVESTMENT
(20 years remaining life)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment ,
k$
2,026
140
239
53
345
56
504
3,363
50
3,413
559
3,972
322
81
693
274
5,342
1,068
6,410
585
769
7,764
14
289
8,067
16.2
% of total
25.1
1.7
3.0
0.7
4.3
0.7
6.2
41.7
0.6
42.3
6.9
49.2
4.0
1.0
8.6
3.4
66.2
13.2
79.5
7.3
9.5
96.2
0.2
3.6
Basis
Existing 500-MW midwestern plant with 15-year, 32,500-hr life and 9,200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
92
-------
TABLE A-10. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(20 years remaining life)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35,040 man-hr 12.50
35,040 man-hr 17.00
561,100 tons 0.06
561,100 tons 0.12
2,652,800 kWh 0.029
1,000 hr 17.00
438,000
595,700
159,000
33,700
67,300
76,900
17,000
1,387,600
1.387,600
12.3
16.7
4.5
0.9
1.9
2.2
0,5
39.0
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 9.30% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.02 ft."IS
722,100
693,800
655,400
103,400
2,174,700
3,562,300
20.3
19.5
18.4
2.9
61.0
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
93
-------
TABLE A-ll. MINE DISPOSAL
CAPITAL INVESTMENT
(15 years remaining life)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
7,764
% of total
2
3
3
3
5
1
6
,026
140
239
53
345
56
504
,363
50
,413
559
,972
322
81
693
274
,342
,068
,410
585
769
25.1
1.7
3.0
0.7
4.3
0.7
6.2
41.7
0.6
42.3
6.9
49.2
4.0
1.0
8.6
3.4
66.2
13.2
79.5
7.3
9. 5
96.2
Land
Working capital
Total capital investment
$/kW
14
289
8,067
16.2
0.2
3 6
~f • U
Basis
Existing 500-MW midwestern plant with 20-year, 57,500-hour life and Q
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1 5 >
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS- 57
solids slurry dewatered to 60% solids, blended with fly ash and t- \ A
1 mile to surface mine; mid-1979 cost basis. ' urucked
94
-------
TABLE A-12. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(15 years remaining life)
Annual quantity Cost,
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - k°L of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35
35
561
561
2,652
1
,040 man-hr
,040 man-hr
, 100 tons
,100 tons
,800 kWh
,000 hr
12.
17.
0.
0.
0.
17.
$/unit
50
00
.06
,12
,029
,00
Annual revenue
requirements, $
438
595
159
33
67
76
17
1,387
1,387
,000
,700
,000
,700
,300
,900
,000
,600
,600
% of total
11.
16.
4.
0.
1.
2.
0.
37.
9
2
3
9
8
1
5
7
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 10.8% Of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/kWh $/ton waste
1.05 6.56
838,500
693,800
655,400
103,400
2,291,100
3,678,700
22.8
18.9
17.8
2.8
62.3
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
95
-------
TABLE A-13. MINE DISPOSAL
CAPITAL INVESTMENT
(2% sulfur in coal)
Capital investment,
k$ % of total
Process equipment 1,532 21.7
Piping and insulation 140 2.0
Foundation and structural 236 3.3
Excavation and site preparation 44 0.6
Electrical 325 4.6
Instrumentation 54 0.8
Buildings 504 7.1
Total 2,835 40.2
Services and miscellaneous 43 0.6
Total 2,878 40.8
Mobile equipment 559 7.9
Total direct investment 3,437 48,7
Engineering design and supervision 322 4.5
Architect and engineering contractor 81 iti
Construction expense 601 8.5
Contractor fees 245 3.5
Total 4,686 66.4
Contingency 937 13.3
Total fixed investment 5,623 79.7
Allowance for startup and modifications 506 7.2
Interest during construction 675 9.6
Total depreciable investment 6,804 95 5
Land
Working capital
Total capital investment
$/kW
10
242
7,056
14.1
0.1
3.4
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 2.0% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5*
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
96
-------
TABLE A-14. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(2% sulfur in coal)
Annual quantity Cost,
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
El ectricity
Analyses
Total conversion costs
Total direct costs
35,
26,
345,
345,
2,015,
1,
040
280
100
100
700
000
man-hr
man-hr
tons
tons
kWh
hr
12
17
0
0
0
17
$/unit
.50
.00
.06
.12
.029
.00
Annual revenue
requirements, $
438
446
137
20
41
58
17
1,159
1 ,159
,000
,800
,000
,700
,400
,500
,000
,400
,400
% of total
14.
15.
4.
0.
1.
2.
0.
39.
9
2
7
7
4
0
6
5
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
0.84 8.51
532,800
606,800
550,500
88,500
1,778,600
2,938,000
18.1
20.7
18.7
3.0
60.5
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
97
-------
TABLE A-15. MINE DISPOSAL
CAPITAL INVESTMENT
(5% sulfur In coal)
—
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
- _
Capital investment,
k$
2,465
151
248
62
380
63
504
3,873
58
3,931
642
4,573
322
81
779
305
6,060
1,212
7,272
663
873
8,808
17
336
9,161
18.3
% of total
26.9
1 6
2.7
4.1
5'5
42.3
0.6
42.9
7.0
49.9
3.5
0.9
3 3
66.1
13.2
79.4
7 ">
9* 5
96.1
0.2
3.7
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9 000
Btu/kWh heat rate; 5.0% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5*
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS- 15?
solids slurry dewatered to 60% solids, blended with fly ash, and truck d°
1 mile to surface mine; mid-1979 cost basis.
98
-------
TABLE A-16. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(5% sulfur in coal)
Annual revenue
Annual quantity Cost, $/unlt requirements, $
of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35,040 man-hr 12.50
43,800 man-hr 17.00
750,400 tons 0.06
750,400 tons 0.12
3,519,600 kWh 0.029
1,000 hr 17.00
438,000
744,600
183,000
45,000
90,000
102,100
17,000
1,619,700
1,619,700
11.0
18.7
4.6
1.1
2.3
2.6
0.4
40.7
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.14
5.30
689,700
787,800
758,800
118,300
2,354,600
3,974,301)
17.4
19.8
19.1
3.0
59.3
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
99
-------
TABLE A-17. MINE DISPOSAL
CAPITAL INVESTMENT
(12% ash in coal)
Capital investment,
k$ % of total
Process equipment 1,788 z4 .1
Piping and insulation 139 1.9
Foundation and structural 184 2.5
Excavation and site preparation 52 0.7
Electrical 306 4.1
Instrumentation 54 0.7
Buildings 504 6.8
Total 3,027 40.8
Services and miscellaneous 45 0.6
Total 3,072 41.4
Mobile equipment 559 7.5
Total direct investment 3,631 48.9
Engineering design and supervision 322 4.3
Architect and engineering contractor 81 1.1
Construction expense 635 8.6
Contractor fees 238 3.2
Total 4,907 66.1
Contingency 981 13.2
Total fixed investment 5,888 79.3
Allowance for startup and modifications 533 7.2
Interest during construction 707 9.5
Total depreciable investment 7,128 96.0
Land 12 0.2
Working capital 282 3.8
Total capital investment 7,422
$/kW 14.8
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 12% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
100
-------
TABLE A-18. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(12% ash in coal)
Annual quantity
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35
35
468
468
2,558
1
,040 man-hr
,040 man-hr
,300 tons
,300 tons
,800 kWh
,000 hr
Cost,
12
17
0
0
0
17,
$/unit
.50
.00
.06
.12
.029
.00
Annual revenue
requirements. $
A 38
595
145
28
56
74
17
1,354
1,354
,000
,700
,000
,100
,200
,200
,000
,200
,200
7. of
13.
18,
4.
0.
1.
2.
0.
41 .
total
,3
. 1
4
9
7
2
5
1
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.67. of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Mills/kWh $/ton waste
Equivalent unit revenue requirements 0.94 7.03
588,100 16.9
638,300 19.4
640,000 19.4
103,400 3.1
1,939,800 58.9
3,294,000
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
101
-------
TABLE A-19. MINE DISPOSAL
CAPITAL INVESTMENT
(20% ash in coal)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,173
140
311
55
340
56
504
3,579
54
3,633
642
4,275
322
81
729
290
5,697
1,139
6,836
619
820
8,275
16
298
8,589
17.2
% of total
25.3
1.6
3.6
0.6
4.0
0.6
5.9
41.7
0.6
42.3
7.5
49.8
3.7
0.9
8.4
3.4
66.3
13.3
79.6
7.2
9.5
96.3
0.2
3.5
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 20% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
102
-------
TABLE A-20. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(20% ash in coal)
Annual revenue
Annual quantity Cost. $/unit requirements, $
% of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35,040 man-hr 12.50
35,040 man-hr 17.00
638,800 tons 0.06
638,800 tons 0.12
3,754,600 kWh 0.029
1,000 hr 17.00
438,000
595,700
171,000
38,300
76,700
108,900
17,000
1,445,600
1,445,600
12.2
16.5
4.7
1.1
2.1
3.0
0.5
40.1
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.03 5.64
647,900
738,700
668,400
103,400
2,158,400
3,604,000
18.0
20.5
18.6
2.9
59.9
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
103
-------
TABLE A-2.T. MINE DISPOSAL
CAPITAL INVESTMENT
(5 miles to disposal)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
1,985
139
242
53
345
56
504
3,324
50
3,374
890
4,264
322
81
686
289
5,642
1,128
6,770
588
812
8,170
14
370
8,554
17.1
% of total
23.2
1.6
2.8
0.6
4.0
0.7
5.9
38.9
0.6
39.4
10.4
49.8
3.8
0.9
8.0
3.4
66.0
13.2
79.1
6.9
9.5
95.5
0.2
4.3
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurrv dewatpred to 6O7 solids, blended with fly ash, and trucked
5 miles to surface mine; mid-1979 cost basis.
104
-------
TABLE A-22. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(5 miles to disposal)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35,040 man-hr 12.50
52,560 man-hr 17.00
548,800 tons 0.20
548,800 tons 0.12
2,652,800 kWh 0.029
1,000 hr 17.00
438,000
893,500
171,000
109,800
65,900
76,900
17,000
1,772,100
1,772,100
10.6
21.6
4.1
2.7
1.6
1.9
0.4
42.9
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 507, of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
639,700
735,600
847,600
133,200
2,356,100
4,128,200
15.5
17.8
20.5
3.2
57.1
Mills/kWh $/ton waste
1.18 7.52
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
105
-------
TABLE A-23. MINE DISPOSAL
CAPITAL INVESTMENT
(10 miles to disposal)
—
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
1,985
139
242
53
345
56
504
3,324
50
3,374
1,055
4,429
322
81
686
297
5,815
1.163
6,978
592
837
8,407
14
425
8,846
17.7
% of total
22.4
1.6
2.7
0.6
3.9
0.6
5.7
37.5
0.6
38.1
11.9
50.0
3.6
0.9
7.8
3.4
65.7
13.2
78.9
6.7
9.5
95.1
0.2
4.7
Basis
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3,5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
staichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
10 miles to surface mine; mid-1979 cost basis.
106
-------
TABLE A-24. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(10 miles to disposal)
Annual quantity
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35
61
548
548
2,652
1
,040
,320
,800
,800
,800
,000
man-hr
man-hr
tons
tons
kWh
hr
Cost,
12
17
0
0
0
17
$/unit
.50
.00
.39
.12
.029
.00
Annual revenue
requirements, $
438
1,042
177
214
65
76
17
2,031
2,031
,000
,400
,000
,000
,900
,900
,000
,200
,200
% of
9
22
3
4
1
1
0
44
total
.6
.9
.9
.7
.5
.7
.4
.7
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% Of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/ktfh
1.30
$/ton waste
8.28
658,300
729,800
977,200
148.000
2,513,300
4,544,500
14.5
16.1
21.5
3.3
55.3
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
107
-------
TABLE A-25. MINE DISPOSAL
CAPITAL INVESTMENT
(200-MW constant load)
Capital investment,
k$
% of total
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
1,211
117
122
40
284
52
504
2,330
35
2,365
476
2,841
288
72
511
212
3,924
785
4,709
423
565
5,697
11
209
5,917
29.6
20.5
2.0
2.0
0.7
4.8
0.9
8.5
39.4
0.6
40.0
8.0
48.0
4.9
1.2
8.6
3.6
66.3
13.3
79.6
7.2
9.5
96.3
0.2
3.5
Basis
New 200-MW midwestern plant with 30-year, 210,000-hour life and 9 200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5'
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS- 157
solids slurry dewatered to 60% solids, blended with fly ash, and trucked"
1 mile to surface mine; mid-1979 cost basis.
108
-------
TABLE A-26. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(200-MW constant load)
Annual quantity Cost,
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - k'/, of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
26,
26,
224,
224,
1,788,
1,
280
280
400
400
500
000
man-hr
man-hr
tons
tons
kWh
hr
12.
17,
0,
0.
0.
17.
$/unit
,50
.00
,06
,12
,031
,00
Annual revenue
requirements, $
328
446
114
13
26
55
17
1,002
1,002
,500
,800
,000
,500
,900
,400
,000
,100
,100
% of
13
17
4
0
1
2
0
39
total
.1
.8
.6
.5
.1
.2
.7
.9
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.79
11.18
446,100
508,900
473,400
77,500
1,505,900
2,508,000
17.8
20.3
18.9
3.1
60.1
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
109
-------
TABLE A-27. MINE DISPOSAL
CAPITAL INVESTMENT
(500-MW constant load)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
1,985
139
242
53
345
56
504
3,324
50
3,374
559
3,933
322
81
686
272
5,294
1,059
6,353
579
762
7,694
14
288
7,996
16.0
% of total
24.8
1.7
3.0
0.7
4.3
0.7
6.3
41.6
0.6
42.2
7.0
49.2
4.0
1.0
8.6
3.4
66.2
13.2
79.5
7.2
9.5
96.2
0.2
3.6
Basis
New 500-MW midwestern plant with 30-year, 210,000-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS; 15%
solids slurry dewatered to 60% solids, blended with fly ash, and trucked
1 mile to surface mine; mid-1979 cost basis.
110
-------
TABLE A-28. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(500-MW constant load)
Annual quantity Cost, $/unit
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4X of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
35,040 man-hr
35,040 man-hr
548,800 tons
548,800 tons
2,652,800 kWh
1,000 hr
12.50
17.00
0.06
0.12
0.029
17.00
Annual revenue
requirements, $
438,000
595,700
157,000
32,900
65,900
76,900
17,000
1,383,400
1,383,400
% of total
12.8
17.4
4.6
1.0
1.9
2.2
0.5
40.3
Ijidirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 101 of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
0.98
$/ton waste
6.25
602,400
687,700
653,300
103.400
2,046,800
3,430,200
17.6
20.0
19.1
3.0
59.7
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
Ill
-------
TABLE A-29. MINE DISPOSAL
CAPITAL INVESTMENT
(1500-MW constant load)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment
k$
4,152
214
1,264
85
540
80
954
7,289
109
7,398
1,104
8,502
438
110
1,316
488
10,854
2,171
13,025
1,192
1,563
15,780
28
498
16,308
10.9
>
% of total
25.5
1.3
7.8
0.5
3.3
0.5
5.8
44.7
0.7
45.4
6.8
52.1
2.7
0.7
8.0
3.0
66.5
13.3
79.8
7.3
9.6
96.8
0.2
3.0
Basis
New 1,500-MW midwestern plant with 30-year, 210,000-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash, and
trucked 1 mile to surface mine; mid-1979 cost basis.
112
-------
TABLE A-30. MINE DISPOSAL
ANNUAL REVENUE REQUIREMENTS
(1500-MW constant load)
Annual quantity Cost, $/unit
Direct Costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Mine disposal operation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
43,800 man-hr
61,320 man-hr
1,646,100 tons
1,646,100 tons
5,994,900 kWh
1,500 hr
12.50
17.00
0.06
0. 12
0.027
17.00
Annual revenue
requirements, $
547,500
1,042,400
340,000
98,800
197,500
161,900
25,500
2,413,600
2,413,600
I of total
8.6
16.4
5.4
1.6
3.1
2.6
0.4
38.1
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
0.60
$/ton waste
3.85
1,235,600
1,402,300
1,125,900
159.000
3,922,800
6,336,400
19.5
22.1
17.8
2.5
61.9
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
113
-------
TABLE A-31. DRAVO LANDFILL
CAPITAL INVESTMENT
(Base case)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
?/kW
8,920
581
503
10,004
20.0
% of total
2
3
3
4
6
_1
7
,161
151
264
58
367
60
654
,715
56
,771
790
,561
426
107
752
301
,147
,229
,376
659
885
21.6
1.5
2.6
0.6
3.7
0.6
6.5
37.1
0.6
37.7
7.9
45.6
4.3
1.1
7.5
3.0
61.4
12.3
73.7
6.6
8.9
89.2
5.8
5.0
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
114
-------
TABLE A-32. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(Base case)
Annual revenue
Annual quantity Cost. $/unlt requirements, $ % of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4£ of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,100 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17.00
563,900 tons 0.06
563,900 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
966,400
966,400
438,000
744,600
182,000
15,100
33,800
90,200
107,900
17,000
1,628,600
2,595,000
19.2
19.3
8.7
14.8
3.6
0.3
0.7
1.8
2.1
0.3
32.4
51.6
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh ?/ton waste
1.44 8.9
698,400
360,300
760,400
118,300
2,437,400
5,032,400
13.9
17.1
15.1
2.4
48.4
Basis: One-year, 7,000 hour operation of system described in capital Investnent summary; mid-1980 cost basis.
115
-------
TABLE A-33. DRAVO LANDFILL
CAPITAL INVESTMENT
(200 MW)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
1,320
126
132
44
300
56
564
2,542
38
2,580
707
3,287
392
98
549
237
4,563
913
5,476
477
657
6,610
242
328
7,18Q
35.9
of total
18.4
1.7
1.8
0.6
4.2
0.8
7.9
35.4
0.5
35.9
9.9
45.8
5.5
1.4
7.6
3.3
63.6
12.7
76.3
6.6
9.2
92.1
3.4
4.6
Basis:
New 200-MW midwestern plant with 30-year, 127,500-hour life and 9,200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
116
-------
TABLE A-34. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(200 MW)
Annual revenue
Annual quantity Cost, $/unit requirements, $ % of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
6,300 tons 64.00
26,280 man-hr 12.50
35,040 man-hr 17.00
230,700 tons 0.06
230,700 tons 0.16
2,328,100 kWh 0.031
1,000 hr 17.00
403,200
403,200
328,500
595,700
131,000
6,200
13,800
36,900
72,200
17.000
1,201,300
1,604,500
11.9
11.8
9.7
17.5
3.7
0.2
0.4
1.1
2.1
0.5
35.3
47.2
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
2.43 14.72
517,600
617,500
564,600
92.400
1,792,100
3,396,600
15.2
18.2
16.6
2.7
52.8
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
117
-------
TABLE A-35. DRAVO LANDFILL
CAPITAL INVESTMENT
(1500 MW)
Capital investment,
k$ % of total
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
4,498
234
1,389
95
579
87
1,404
8,286
124
8,410
1,335
9,745
438
109
1,464
542
12,298
2,460
14,758
1,342
1,771
17,871
1,729
1,032
20,632
13.8
21.7
1.1
6.7
0.5
2.8
0.4
6.8
39.9
0.6
40.5
6.4
46.9
2.1
0.5
7.0
2.6
59.2
11.8
71.1
7.1
8.5
86.7
8.3
5.0
Basis:
New 1,500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
118
-------
TABLE A-36. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(1500 MW)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmovlng equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
45,200 tons 64.00
43,800 man-hr 12.50
70,080 man-hr 17.00
1,691,200 tons 0.06
1,691,200 tons 0.16
8,283,800 kWh 0.027
1,500 hr 17.00
2,892,800
2,892,800
547,500
1,191,400
390,000
45,400
101,500
270,600
223,700
25,500
2,795,600
5,688,400
28.0
28.0
5.3
11.5
0.4
1.0
2.6
2.2
0.2
27.0
55.0
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/kWh $/ton waste
0.98 6.10
1,399,300
1,774,400
1,286,000
173,900
4,633,600
10,322,000
13.6
17.2
12.5
1.7
45.0
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
119
-------
TABLE A-37. DRAVO LANDFILL
CAPITAL INVESTMENT
(25 years remaining life)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,202
152
260
59
368
61
654
3,756
56
3,812
790
A, 602
426
107
759
306
6,200
1,240
7,440
665
893
8,998
434
528
9,960
19.9
— — ... .
% of total
22.1
1.5
2.6
0.6
3.7
0.6
6.6
37.7
0.6
38.3
7.9
46.2
4.3
1.1
7.6
3.1
62.3
12.4
74.7
6.7
9 0
J t U
90.4
4.3
5.3
Basis:
Existing 500-MW midwestern plant with 25-year, 92,500-hour life and 9 200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS•
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
120
-------
TABLE A-38. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(25 years remaining life)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,400 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17.00
576,500 tons 0.06
576,500 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
985,600
985,600
438,000
744,600
184,000
15,500
34,600
92,200
107,900
17,000
1,633,800
2,619,400
19.1
19.1
8.5
14.5
3.6
0.3
0.7
1.8
2.1
0.3
31.8
50.9
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 8.80% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.47 8.93
791,800
856,600
763,000
118,300
2,529,700
5,149,100
15.4
16.6
14.8
2.3
49.1
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
121
-------
TABLE A-39. DRAVO LANDFILL
CAPITAL INVESTMENT
(20 years remaining life)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
2
3
3
4
6
JL
7
,202
152
260
59
368
61
654
,756
56
,812
790
,602
426
107
759
306
,200
,240
,440
655
893
22.5
1.5
2.7
0.6
3.8
0.6
6.7
38.4
0.6
39.0
8.0
47.0
4.3
1.1
7.8
3.1
63.3
12.7
76.0
6-7
9.1
8,988
111
528
9,793
19.6
91.8
2.8
5.4
Basis:
Existing 500-MW midwestern plant with 20-year, 57,500-hour life and 9 200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS-
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
122
-------
TABLE A-40. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(20 years remaining life)
Annual revenue
Annual quantity Cost, $/unlt requirements, $
of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct Investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,400 tons 64.00
35,040 man-hr 12.50
43,300 man-hr 17.00
576,500 tons 0.06
576,500 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
985,600
985,600
438,000
744,600
184,000
15,500
34,600
92,200
107,900
17,000
1,633,800
2,619,400
19.0
19.0
8.5
14.4
3.5
0.3
0.7
1.8
2.1
0.3
31.5
50.6
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 9.30% of total
depreciable Investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/kWh
1.48
$/ton waste
8.98
835,900
842,200
763,000
118,300
2,559,400
5,178,800
16.1
16.3
14.7
2.3
49.4
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
123
-------
TABLE A-41. DRAVO LANDFILL
CAPITAL INVESTMENT
(15 years remaining life)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,202
152
260
59
368
61
654
3,756
56
3,812
790
A, 602
426
107
759
306
6,200
1,240
7,440
655
893
8,988
161
528
9,677
19.4
% of total
22.7
1.6
2.7
0.6
3.8
0.6
6.8
38.8
0.6
39.4
8.2
47.6
4.4
1.1
7.8
3.2
64.1
12.8
76.9
6.8
9.2
92.9
1.6
5.5
Basis:
Existing 500-MW midwestern plant with 15-year, 32,500-hour life and 9,200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
124
-------
TABLE A-42. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(15 years remaining life)
Annual revenue
Annual quantity Cost. $/unit requirements, $
of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,400 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17.00
576,500 tons 0.06
576,500 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
985,600
985,600
438,000
744,600
184,000
15,500
34,600
92,200
107,900
17,000
1,633,800
2,619,400
18.6
18.5
8.3
14.0
3.5
0.3
0.7
1.7
2.0
0.3
30.8
49.4
indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 10.8% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
1.52
?/ton waste
9.20
970,700
832,200
763,000
118,300
2,684,200
5,303,600
18.3
15.7
14.4
2.2
50.6
Basis: One-year, 7,000 hour operation of system described in capital Investment summary; mid-1980 cost basis.
125
-------
TABLE A-43. DRAVO LANDFILL
CAPITAL INVESTMENT
(2% sulfur in coal)
Capital investment,
k$
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
1,665
152
256
48
353
59
594
3,127
50
3,177
790
3,967
426
107
644
274
5,418
1,084
6,502
571
780
19.4
1.8
3.0
0.6
4.1
0.7
6.9
36.4
0.6
37.0
9.2
46.2
5.0
1.2
7.5
3.2
63.1
12.6
75.7
6.7
9.1
7,853
364
369
8,586
17.2
91.5
4.2
4.3
Basis:
L£3-1-9 .
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 2.0% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly asb collection to NSPS•
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
126
-------
TABLE A-44. -DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(2% sulfur In coal)
Annual revenue
Annual quantity Cost. $/unit requirements. $ % of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct Investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmovlng equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
6,700 tons 64.00
35,040 man-hr 12.50
35,040 man-hr 17.00
351,800 tons 0.06
351,800 tons 0.16
2,743,300 kWh 0.029
1,000 hr 17.00
428.800
428,800
438,000
595,700
159,000
9,400
21,100
56,300
79,600
17,000
1,376,100
1,804,900
11.0
10.9
11.2
15.2
4.1
0.2
0.5
1.4
2.0
0.4
35.1
46.1
Indirect Costs
Capital charges
Depreciation, Interim replacement,
. and Insurance at 7.83% of total
depreciable Investment
Average cost of capital and taxes
at 8.6Z of total capital Investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total Indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/kwh
1.12
$/ton waste
11.11
614,900
738,400
648,300
103.400
2,105,000
3,909,900
15.7
18.9
16.6
2.6
53.9
Basis: One-year, 7,000 hour operation of system described in capital Investment summary; mid-1980 cost basis.
127
-------
TABLE A-45. DRAVO LANDFILL
CAPITAL INVESTMENT
(5% sulfur in coal)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,700
165
272
68
416
69
704
4,394
66
4,460
873
5,333
426
107
865
343
7,074
1,415
8,489
762
1,019
10,270
795
858
11,923
23.9
% of total
22.7
1.4
2 3
*- • J
0.6
3.5
0.6
5.9
37.0
0.6
37.6
7.3
44.9
3.6
0 9
V • j
1 7
/ * £-
1 9
*• • 7
59.5
11.9
71.4
ft /,
O • fJ.
8.5
86.3
ft f.
0 . O
7 1
• » J.
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9 000
Btu/kWh heat rate; 5.0% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5*
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS-
15% solids slurry dewatered to 60% solids, blended with fly ash and '
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
128
-------
TABLE A-46. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(5% sulfur in coal)
Annual revenue
Annual quantity Cost, $/unit requirements, $
% of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 43! of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
23,500 tons 64.00
35,040 man-hr 12.50
52,600 man-hr 17.00
733,900 tons 0.06
733,900 tons 0.16
4,717,200 kWn 0.029
1,000 hr 17.00
1,504,000
1,504,000
438,000
893,500
213,000
20,800
44,000
117,400
136,800
17,000
1,880,500
3,384,500
22.6
22.6
6.6
13.4
3.2
0.3
0.6
1.7
2.1
0.2
28.1
50.7
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 507, of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
1.90
$/ton waste
8.61
804,100
1,025,400
1,318,600
133.200
3,281,300
6,665,800
12.1
15.4
19.8
2.0
49.3
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
129
-------
TABLE A-47. DRAVO LANDFILL
CAPITAL INVESTMENT
(12% ash in coal)
Capital investment,
k$% of total
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
In s t rumen t at ion
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
1,939
151
200
56
332
59
634
3,371
51
3,422
790
4,212
426
107
694
286
5,725
1,145
6,870
608
824
8,302
497
503
9,302
18.6
20.8
1.6
2.2
0.6
3.6
0.6
6.8
36.2
0.6
36.8
8.5
45.3
4.6
1.1
7.5
3.1
61.6
12.3
73.9
6.5
8.9
89.3
5.3
5 .4
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 12% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
130
-------
TABLE A-48. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(12% ash in coal)
Annual revenue
Annual quantity Cost, $/unlt requirements, $ % of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct Investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmovlng equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
14.000 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17,00
482,300 tons 0.06
482,300 tons 0.16
3,615,300 kWh 0.029
1,000 hr 17.00
896,000
896,000
438,000
744.600
168,000
12,900
28,900
77,200
104,800
17,000
1,591,400
2,487,400
18.7
18.7
9.1
15.5
3.5
0.3
0.6
1.6
2.2
0.4
33.1
51.8
Indirect Costa
Capital charges
Depreciation, interim replacement,
and Insurance at 7. 83% of total
depreciable Investment
Average cost of capital and taxes
at 8.6% of total capital Investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Mllls/kWh $/ton waste
Equivalent unit revenue requirements 1.37 9.95
650,100
800,000
743,300
118.300
2,311,600
4,799,00
13.5
16.7
15.5
2.5
48.2
Baals: One-year, 7,000 hour operation of system described In capital Investment summary; mid-1980 cost basis.
131
-------
TABLE A-49. DRAVO LANDFILL
CAPITAL INVESTMENT
(20% ash in coal)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,343
151
335
59
367
60
684
3,999
60
4,059
873
4,932
426
107
800
323
6,588
1,318
7,906
703
949
9,558
676
515
10,749
21.5
% of total
21.8
1.4
3.1
0.5
3.4
0.6
6.4
37.2
0.6
37.8
8.1
45.9
4.0
1.0
7.4
3 0
61.3
12.3
73.6
6
-------
TABLE A-50. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(20% ash in coal)
Annual revenue
Annual quantity Cost, $/unit requirements, $
% of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - k"/« of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
16,100 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17.00
654,900 tons 0.06
654,900 tons 0.16
4,759,000 kWh 0.029
1,000 hr 17.00
1,030,400
1,030,400
438,000
744,600
197,000
17,600
39,300
104,800
138,000
17,000
1,696,300
2,726,700
19.5
19.5
8.3
14.1
3.7
0.3
0.7
2.0
2.6
0.3
32.0
51.5
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at S.dZ of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh S/ton waste
1.51
8.09
748,400
924,400
779,200
118,300
2,570,300
5,297,000
14.1
17.5
14.7
2.2
48.5
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
133
-------
TABLE A-51. DRAVO LANDFILL
CAPITAL INVESTMENT
(5 miles to disposal)
Capital investment,
k$ % of total
Process equipment 2,161 20.4
Piping and insulation 151 1.4
Foundation and structural 264 2.5
Excavation and site preparation 58 0.6
Electrical 367 3.5
Instrumentation 60 0.6
Buildings 654 6.2
Total 3,715 35.2
Services and miscellaneous 56 0.5
Total 3,771 35.7
Mobile equipment 1,121 10.6
Total direct investment 4,892 46.3
Engineering design and supervision 426 4.0
Architect and engineering contractor 107 1.0
Construction expense 752 7.1
Contractor fees 321 3.0
Total 6,498 61.5
Contingency 1,300 12.3
Total fixed investment 7,798 73.8
Allowance for startup and modifications 668 6.3
Interest during construction 936 8.8
Total depreciable investment 9,402 88.9
Land 581 5.5
Working capital 590 5.6
Total capital investment 10,573
$/kW 21.2
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 5 miles to landfill; mid-1979 cost basis.
134
-------
TABLE A-52. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(5 miles to disposal)
Annual revenue
Annual quantity Cost, $/unit requirements, $
% of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,100 tons 64.00
35,040 man-hr 12.50
61,320 man-hr 17.00
563,900 tons 0.20
563,900 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
966,400
966,400
438,000
1,042,400
196,000
15,100
112,800
90,200
107,900
17,000
2,019,400
2,985,800
7.6
18.2
3.4
0.3
2.0
1.6
1.9
0.3
35.3
52.1
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital Investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.64
10.17
736,200
909,300
955,800
148,000
2,749,300
5,735,100
12. 3
15.8
16.7
2.6
47.9
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
135
-------
TABLE A-53. DRAVO LANDFILL
CAPITAL INVESTMENT
(10 miles to disposal)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
2,161
151
264
58
367
60
654
3,715
56
3,771
1,286
5,057
A26
107
752
329
6,671
1.334
8,005
672
961
9,638
581
624
10,843
21.7
% of total
19.9
1.4
2.4
0.5
3.4
0.6
6.0
34.3
0.5
34.8
11.9
46.6
3.9
1.0
6.9
3.0
61.5
12.3
73.8
6 7
8'.9
88.9
5 L
J ' H
5.7
Basis:
New 500-MW midwestern plant with 30-year, 127,500-hour life and 9 000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5'
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS•
15% solids slurry dewatered to 60% solids, blended with fly ash and '
Calcilox, and trucked 10 miles to landfill; mid-1979 cost basis
136
-------
TABLE A-54. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(10 miles to disposal)
Annual revenue
Annual quantity Cost, $/unit requirements, $
of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,100 tons 64.00
35,040 man-hr 12.50
70,080 man-hr 17.00
563,900 tons 0.39
563,900 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
966,400
966,400
438,000
1,191,400
202,000
15,100
219,900
90,200
107,900
17,OOP
2,281,500
3,247,900
15.6
15.6
7.1
19.3
3.3
0.2
3.6
1.5
1.7
0.3
36.9
52.5
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh $/ton waste
1.77 10.97
754,700
932,500
12.2
15.1
17.6
2.6
47.5
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
137
-------
TABLE A-55. DRAVO LANDFILL
CAPITAL INVESTMENT
(200-MW constant load)
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
Capital investment,
k$
1,320
126
132
44
300
56
564
2,542
38
2,580
707
3,287
392
98
549
237
4,563
913
5,476
477
657
6,610
392
328
7,330
36.7
% of total
18.0
1.7
1.8
0.6
4 1
0.8
7.7
34.7
0.5
35.2
9.6
44.8
5.4
1.3
7.5
3.2
£. O O
D^ . 2.
12.5
74.7
6.5
9.0
90.2
5
4.5
Basis:
New 200-MW midwestern plant with 30-year, 210,000-hour life and 9 200
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5'
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS•
15% solids slurry dewatered to 60% solids, blended with fly ash and '
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis
138
-------
TABLE A-56. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(200-MW constant load)
Annual revenue
Annual quantity Cost, $/unit requirements, $ 7. of total
Direct Costs
Delivered raw materials
Calcllox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Trurk fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
6.300 tons 64.00
26,280 man-hr 12.30
35,040 man-hr 17.00
230,700 tons 0.06
230,700 tons 0.16
2,328,100 kWh 0.031
1,000 hr 17.00
403,200
403.200
328,500
595,700
131,000
6,200
13,800
36,900
72,200
17,000
1,201.300
1,604,500
Ik?
11.8
9.6
17.5
0.2
0.4
1.1
2.1
0.5
35.2
47.0
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.67, of total capital Investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
2.44
$/ton waste
14.78
517,600
630,400
564,600
92,400
1,805,000
3,409,500
15.2
18.5
16.6
2.7
53.0
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
139
-------
TABLE A-57. DRAVO LANDFILL
CAPITAL INVESTMENT
(500-MW constant load)
Capital investment,
k$
of total
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
S/kW
2,161
151
264
58
367
60
654
3,715
3,771
790
4,561
426
107
752
301
8,920
949
523
10,392
20.8
20.8
1.5
2.5
0.6
3.5
0.6
6.3
35.8
0.5
36.3
7.6
43.9
4.1
1.0
7.2
2.9
59.1
11.8
71.0
6.3
8.5
9.1
5.0
Basis:
New 500-MW midwestern plant with 30-year, 210,000-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS;
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
140
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TABLE A-58. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(500-MW constant load)
Annual revenue
Annual quantity Cost, ?/unlt requirements, $ % of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
15,100 tons 64.00
35,040 man-hr 12.50
43,800 man-hr 17.00
563,900 tons 0.06
563,900 tons 0.16
3,722,400 kWh 0.029
1,000 hr 17.00
966.400
966,400
438,000
744,600
182,000
15,100
33,800
90,200
108,000
17.000
1,628,700
2,595,100
19.1
19.1
8.6
14.7
3.6
0.3
0.7
1.8
2.1
0.3
32.1
51.2
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 10% of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mllls/kWh $/ton waste
1.45 8.98
698,400
893,700
760,400
118.300
2,470,800
5,065,900
13.8
17.6
15,0
2.3
48.8
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis.
141
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TABLE A-59. DRAVO LANDFILL
CAPITAL INVESTMENT
(1500-MW constant load)
Capital investment,
k$ % of total
Process equipment
Piping and insulation
Foundation and structural
Excavation and site preparation
Electrical
Instrumentation
Buildings
Total
Services and miscellaneous
Total
Mobile equipment
Total direct investment
Engineering design and supervision
Architect and engineering contractor
Construction expense
Contractor fees
Total
Contingency
Total fixed investment
Allowance for startup and modifications
Interest during construction
Total depreciable investment
Land
Working capital
Total capital investment
$/kW
A, 498
234
1,389
95
579
87
1,404
8,286
124
8,410
1,335
9,745
438
109
1,464
542
12,298
2,460
14,758
1,342
1,771
17,871
2,828
1,084
21,783
14.5
20.6
1.1
6.4
0.4
2.7
0.4
6.4
38.0
0.6
38.6
6.1
44.7
2.0
0.5
6.7
2.5
56.4
11.3
67.7
6.2
8.1
82.0
13.0
5.0
Basis:
New 1,500-MW midwestern plant with 30-year, 210,000-hour life and 9,000
Btu/kWh heat rate; 3.5% sulfur, 16% ash, 10,500 Btu/lb coal; 1.5
stoichiometry limestone scrubbing and ESP fly ash collection to NSPS •
15% solids slurry dewatered to 60% solids, blended with fly ash and
Calcilox, and trucked 1 mile to landfill; mid-1979 cost basis.
142
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TABLE A-60. DRAVO LANDFILL
ANNUAL REVENUE REQUIREMENTS
(1500-MW constant load)
Annual revenue
Annual quantity Cost. $/unit requirements. $ 7. of total
Direct Costs
Delivered raw materials
Calcilox
Total raw material costs
Conversion costs
Operating labor and supervision
Plant
Disposal equipment
Plant maintenance - 4% of
direct investment
Landfill operation
Landfill preparation
Truck fuel and maintenance
Earthmoving equipment fuel
and maintenance
Electricity
Analyses
Total conversion costs
Total direct costs
45,200 tons 64,00
43,800 man-hr 12.50
70,080 man-hr 17.00
1,691,200 tons 0.06
1,691,200 tons 0.16
8,283,800 kWh 0.027
1,500 hr 17.00
2.89 2,800
2.892,800
547,500
1,191,400
390,000
45,400
101,500
270,600
223,700
25.500
2,795,600
5,688,400
27.f
27.8
5.3
11.4
3.7
0.4
1.0
2.6
2.2
0.2
26.8
54.6
Indirect Costs
Capital charges
Depreciation, interim replacement,
and insurance at 7.83% of total
depreciable investment
Average cost of capital and taxes
at 8.6% of total capital investment
Overhead
Plant, 50% of conversion costs less
electricity
Administrative, 107, of total labor
and supervision
Total indirect costs
Total annual revenue requirements
Equivalent unit revenue requirements
Mills/kWh
0.99
$/ton waste
6.16
1,399,300
1.873,300
1,286,000
173,900
4,732,500
10,420,900
13.4
18.0
12.3
1.7
45.4
Basis: One-year, 7,000 hour operation of system described in capital investment summary; mid-1980 cost basis
143
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-80-022
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Economics of Disposal of Lime/Limestone Scrubbing
Wastes: Surface Mine Disposal and Dravo Landfill
Processes
5. REPORT DATE
February 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
J.D.Veitch, A.E.Steele, and T. W.Tarkington
8. PERFORMING ORGANIZATION REPORT NO.
EDT-105
9. PERFORMING ORGANIZATION NAME AND ADDRESS
TVA, Office of Power
Division of Energy Demonstrations and Technology
Muscle Shoals, Alabama 35660
10. PROGRAM ELEMENT NO.
INE624A
11. CONTRACT/GRANT NO.
IAG-D8-E721-BI
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD CC
Task Final; 6/78 - 8/79
COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES J.ERL-RTP project officer is Julian W. Jones, Mail Drop 61, 919/
541-2489.
is. ABSTRACT The repOr|- gives results of economic evaluations of flyash and limestone
scrubbing waste disposal in a surface mine and in a landfill after treatment with a
Dravo Lime Co. chemical additive. For the base case (new 500 MW midwestern
plant burning 3.5% S, 16% ash, 10,500 Btu/lb coal), capital investment for the mine
disposal process is 16. 0 S/kW and annual revenue requirements are 0. 98 mill/kWh,
compared to 20.0 #/kW and 1.44 mills/kWh for the landfill process, excluding dry
flyash collection costs of 19.2 #/kW and 0. 56 mill/kWh. A moderate cost reduction
is obtained for mine disposal, compared to landfill disposal of the same waste, by
eliminating disposal land requirements and reducing earthmoving equipment require-
ments. Purchasing and handling the chemical additive for the landfill process ac-
count for most of the cost differences between the two processes. Power plant size,
coal sulfur and ash contents, and distance to the disposal site have major cost ef-
fects for both processes. Modular cost breakdowns show purchase and handling of
fixatives, thickening, ESP units, and disposal labor to be major cost elements.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Economic Analysis
Waste Disposal
Gas Scrubbing
Calcium Oxides
Calcium Carbonates
Fly Ash
Surface Mining
Earth Fills
Additives
Pollution Control
Stationary Sources
Dravo Landfill Process
13B 21B
05C 081
13C
07A,13H 11G
07B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
173
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
144
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