EPA-650/2-75-057-d
August 1975
Environmental Protection Technology Series
OF FLUE GAS
DESULFURIZATION SYSTEMS
PADDY'S RUN STATION,
LOUISVILLE GAS AND ELECTRIC
01
O
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EPA-650/2-75-057-d
SURVEY
OF FLUE GAS
DESULFURIZATION SYSTEMS
PADDY'S RUN STATION,
LOUISVILLE GAS AND ELECTRIC
by
Gerald A. Isaacs
PEDCo-Environmental Specialists, Inc.
Suite 13, Atkinson Square
Cincinnati, Ohio 45246
Contract No. 68-02-1321, Task 6d
ROAP No. 21ACX-130
Program Element No. 1AB013
EPA Project Officer: Norman Kaplan
Industrial Environmental Research Laboratory
Office of Energy , Minerals , and Industry
Research Triangle Park, North Carolina 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, D. C. 20460
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EPA REVIEW NOTICE
This report has been reviewed by the National Environmental Research
Center - Research Triangle Park, Office of Research and Development,
liPA. and approved lor publication. Approval cJoes not signify that the
contents necessarily reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environ-
mental Protection Agency, have been grouped into series. These broad
categories were established to facilitate further development and applica-
tion of environmental technology. Elimination of traditional grouping was
consciously planned to foster technology transfer and maximum interface
in related fields. These 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
9. MISCELLANEOUS
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to
develop and demonstrate instrumentation, equipment and methodology
to repair or prevent environmental degradation from point and non-
point sources of pollution. This work provides the new or improved
technology required for the control and treatment of pollution sources
to meet environmental quality standards.
This document is available to the public for sale through the National
Technical Information Service, Springfield, Virginia 22161.
Publication No. EPA-650/2-75-057-d
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ACKNOWLEDGMENT
This report was prepared under the direction of Mr.
Timothy W. Devitt. The principal author was Dr. Gerald A.
Isaacs.
Mr. Wade H. Ponder, former EPA Project Officer, had
primary responsibility within EPA for this project report.
Information and data on plant operation were provided by Mr.
R. P. Van Ness, Louisville Gas and Electric Company and by
Mr. Peter Maurin, Combustion Engineering, Inc. during and
subsequent to the survey visit. Mr. Charles D. Fleming was
responsible for editorial review of this report.
The author appreciates the efforts and cooperation of
everyone who participated in the preparation of this report,
111
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TABLE OF CONTENTS
Page
ACKNOWLEDGMENT iii
LIST OF FIGURES vi
LIST OF TABLES vi
SUMMARY vii
1.0 INTRODUCTION 1-1
2.0 FACILITY DESCRIPTION 2-1
2.1 Plant Location 2-1
2.2 Boiler Data 2-1
2.3 Pollution Controls 2-1
3.0 FLUE GAS DESULFURIZATION SYSTEM 3-1
3.1 Process Description 3-1
3.2 Design Parameters 3-5
3.3 Installation Schedule 3-6
3.4 Cost Data 3-9
4.0 FGD SYSTEM PERFORMANCE 4-1
4.1 Start-up Problems and Solutions 4-1
4.2 Performance Test Run 4-3
4.3 Performance Parameters 4-3
4.4 Process Modifications for Future 4-3
Installations
APPENDIX A PLANT SURVEY FORM A-l
APPENDIX B PLANT PHOTOGRAPHS B-l
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LIST OF FIGURES
No.
3.1 General Flow Diagram of the FGD System at 3-3
Paddy's Run
LIST OF TABLES
No. Page
2.1 Pertinent Data on Plant Design, Operation 2-3
and Atmospheric Emissions
3.1 Summary of Data - FGD Scrubbers 3-7
3.2 Summary of Data - FGD System Tanks 3-8
4.1 Availability Summary - Paddy's Run 4-4
VI
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SUMMARY
The flue gas desulfurization (FGD) system on Unit No. 6
at the Paddy's Run Power Station of Louisville Gas and
Electric Company was designed by Combustion Engineering,
Inc. System start-up occurred in April 1973. The system
utilizes a slurry of carbide lime in a marble-bed scrubber.
The carbide lime, a waste by-product obtained from a nearby
acetylene manufacturing plant, contains 90 to 92 percent
calcium hydroxide, 2 to 2.5 percent silica, 3 to 8 percent
calcium carbonate, and 0.1 percent magnesium oxide. The
system operates in a closed-loop mode. Sludge is stabilized
by mixing thickener underflow with carbide lime before
vacuum filtration. The sludge, containing about 40 percent
solids, is trucked to a nearby ten-acre borrow pit that is
used as a landfill area.
The Paddy's Run Power Station is used primarily to meet
summer peaking loads. The No. 6 boiler is operated infre-
quently because of its low thermal efficiency (heat rate is
about 13,000 BTU/KWH). The entire station may be phased-out
in the near future. However, on the basis of the perform-
ance of the Paddy's Run FGD system, Louisville Gas and
Electric Company is pursuing plans to install similar car-
bide lime FGD systems at other power stations.
vn
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SUMMARY OF FGD DATA, PADDY'S RUN UNIT NO. 6
Unit rating
Fuel characteristics
FGD vendor
Process
New or retrofit
Start-up date
FGD modules
Efficiency, %
Particulates
so2
Make-up water
Sludge disposal
Unit cost
65 MW (nameplate), 70 MW (maximum
continuous, net)
Coal: 11,000 BTU/lb;, 14% ash,
3-4% sulfur (as-received)
Combustion Engineering, Inc.
Lime scrubbing
Retrofit
April 1973
Two
99.1 (precipitator)
85
0.7 gpm/MW (net)
Stabilized sludge disposed in
off-site landfill
$3.7 million ($53/net KW) - Capital
$905,000 (2.5 mills/net KWH) - Operating'
Annualized cost projected for 60% capacity factor includes
15% fixed charge.
Vlll
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1.0 INTRODUCTION
The Control Systems Laboratory (CSL) of the U.S. Environ-
mental Protection Agency (EPA) has initiated a study to
evaluate the status of flue gas desulfurization (FGD) systems
on coal-fired boilers in the United States. This report on
the Paddy's Run Power Station of the Louisville Gas and
Electric Company (LG&E) is one of a series of reports on
such systems. It presents values of key process design and
operating parameters, describes the major start-up and
operational problems encountered at the facility and the
measures taken to alleviate such problems, and identifies
total installed and annualized operating costs.
This report is based upon information obtained during a
plant inspection on July 9, 1974, and on data provided by
LG&E and Combustion Engineering, Inc. personnel.
Section 2.0 presents pertinent data on facility design
and operation, including actual and allowable particulate
and SO- emission rates. Section 3.0 describes the FGD
system and Section 4.0 analyzes FGD system performance.
Appendices present details of plant and system operation and
photos of the installation.
1-1
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2.0 FACILITY DESCRIPTION
2.1 PLANT LOCATION
The Paddy's Run Power Station of Louisville Gas and
Electric Company is located on the Ohio River in Rubbertown,
about 10 miles southwest of the center of Louisville, Kentucky,
The terrain around the Paddy's Run Station is relatively
flat and highly industrialized.
Of the six generators at Paddy's Run only the boiler on
Unit 6 is retrofitted with an FGD system.
2.2 BOILER DATA
The boiler on Unit 6, is a dry-bottom, pulverized-coal-
fired unit designed and installed by Foster-Wheeler in 1951.
The generator operates as a peaking unit and has a nameplate
rating equivalent to 65 MW. Its maximum electrical gener-
pt-ing capacity is 70 MW. The station operated at an approxi-
mate 5 percent load factor in 1974. The heat rate for Unit
6 ranges from 13,000 to 13,500 BTU/KWH.
The coal now being burned has an average heating value
(as-received) of 12,400 BTU/lb. Ash and sulfur contents are
14 and 3-4 percent, respectively.
2.3 POLLUTION CONTROLS
A Research-Cottrell electrostatic precipitator (ESP),
2-1
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operating with an efficiency of 99.1 percent provides primary
control of particulate emissions. Particulate loading at
the outlet of the ESP unit is approximately 0.05 grains per
standard cubic foot (gr/scf).
The maximum particulate emission allowed under the Air
Pollution Control Regulation No. 3.1.3 of Jefferson County,
dated April 19, 1972 is 0.1 Ib/MM BTU of heat input. Present
particulate emissions from the unit were indicated to be in
*
compliance with that regulation.
Atmospheric emissions of sulfur dioxide are limited by
Regulation No. 4.0.1 to 1.2 Ib/MM BTU of heat input.
Continuous monitoring equipment shows that SO- emissions are
within the 1.2 Ib/MM BTU limit.
All six generators at the Paddy's Run Station operate
intermittently, on demand, to meet peak load demands only.
For that reason there are no plans to retrofit additional
boilers at the station with FGD systems. Data on plant
operation and emissions appear in Table 2.1.
2-2
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Table 2.1 PERTINENT DATA ON PLANT DESIGN,
OPERATION AND ATMOSPHERIC EMISSIONS
LG&E - PADDY'S RUN, UNIT NO. 6
Boiler Data
Item
Maximum continuous generating capacity,
MW (net)
Average capacity factor (1974), %
Boiler manufacturer
Year placed in service
Maximum heat input, MM BTU/hr
Stack height above grade, ft
Maximum flue gas rate, acfm @ 335°F
Emission controls:
Particulate
S02
Particulate emission rate:
Allowable, Ib/MM BTU
Actual, Ib/MM BTU
SO2 emission rate:
Allowable, Ib/MM BTU
Actual, Ib/MM BTU
70
5.0
Foster-Wheeler
1951
910
250
400,000
Electrostatic precipitator
Marble-bed tower
0.1
0.1
1.2
1.2
2-3
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3.0 FLUE GAS DESULFURIZATION SYSTEM
3.1 PROCESS DESCRIPTION3
The FGD system at the Paddy's Run Station of LG&E was
designed by Combustion Engineering, Inc. Start-up for the
FGD plant occurred in April 1973. The lime scrubbing system
utilizes calcium hydroxide sludge which is generated as a
waste by-product from a nearby acetylene manufacturing
plant. In this FGD process a slurried mixture of calcium
hydroxide and calcium sulfite in water constitutes the
scrubbing liquor. Reaction with S02 in the flue gas takes
place in the liquid phase, where dissolution of calcium
sulfite is the rate-controlling step for S02 absorption.
Following are the principal chemical reactions involved
in this FGD process:
Sulfite formation Ca(OH)2 + S02 — *> CaSO3 + H2O (1)
Bisulfite formation CaSO-j + SO2 + H2O - »-Ca(HS03)2 (2)
Bisulfite neutralization
Ca(HS03)2 + Ca(OH)2 — >• 2 CaSO^ + 2H2O (3)
Sulfate formation 2 CaSO, + 02 — *• 2 CaSO4 (4)
Sulfate formation (Reaction 4) is detrimental to FGD
systems because the sulfate scales and plugs process equipment.
Adapted from "The Combustion Engineering Lime Wet Scrubbing Pro-
cess: from Concept to Commercial Operation," by J.R. Martin,
B.M. Minor, and A.L. Plumley, Combustion Engineering, Inc. October
22-24, 1974, and supplemented with information obtained during
plant visit.
3-1
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The FGD system consists of two identical modules each
sized to handle 175,000 acfm of flue gas at 350°F. Figure
3.1 is a general process flow diagram for the installation.
Each scrubber module is constructed of mild steel coated
with a 1/2-in.-thick fiberglass reinforced polyester (FRP)
flake lining. Internal supports are constructed of type 316
stainless steel. Flue gas enters each scrubber module near
the base and contacts nonatomizing sprays which provide a
constant supply of slurry to the underside of the two stages
of marble beds. This slurry of calcium sulfite and calcium
hydroxide also serves to cool the flue gas adiabatically to
its saturation temperature before it enters the marble bed.
The wetted flue gas rises through the bed (consisting of a
3-inch-thick layer of 1-inch-diameter marbles when at rest)
and carries the slurry with it. The vigorous action of the
marbles mixes the flue gas and slurry to form a "turbulent
layer" above the marble bed. The thickness of the layer is
controlled by the height of the overflow pots. The turbu-
lent layer provides necessary retention time and mixing
intensity to obtain the required degree of S02 absorption
and particulate removal. After emerging from the second
marble bed, the clean flue gas passes through a two-stage
chevron mist eliminator where entrained water droplets are
agglomerated and removed. The flue gas then passes through
a gas-fired reheater, through a booster fan, and out the
stack.
3-2
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GA*. TC STAC*
U)
(*} GAS RfHEfil r ft
4DOITIVE '/STEM
«.»OC IS/MR ORY CilOK,
iLJRRT 2S°/<, t2%
I
GAS INLFT
J2S.OOC CFM EACH
MOTE-
CPU FISU"t5 REPKESENT 30'I RATIO
GPW/IOOC CFU
GAS i^LtT STEAM BLO»EBS
SPDAV WATC*
POT DRAIN WATER
ADDITIVE SLURRr WATER
JCRUBBCR DISCMAROE MATfR
•- CLARITIER BUCHAROE
Figure 3.1 General flow diagram of the FGD system at Paddy's Run.
(Courtesy: Combustion Engineering, Inc.)
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The underflow from the thickener is sent to a rotary
vacuum filter. Filter cake is trucked to an off-site land-
fill area. Vacuum filtrate is recycled to the thickener,
and pumped back to the reaction tank to close the liquid
effluent loop.
Slurry rejected from below the first bed falls onto a
sloping screen in the scrubber bottom. Large particles in
the slurry, such as mud or stray marbles are pulverized and
purged periodically from the system to the thickener via a
comminutor unit. Most of the remainder of the reject slurry
is returned to the reaction tank for reuse. All the calcium
bisulfite slurry that leaves the beds through the overflow
pots is fed by gravity back to the reaction tank, where it
is contacted by fresh slaked carbide lime and converted to
calcium sulfite. Other streams entering the reaction tank
include weir water from the thickener, return water from the
vacuum filter, make-up water, and slurry additives. Me-
chanical agitators in the tank thoroughly blend the in-
gredients to maximize the dissolution of additives and to
complete calcium salt precipitation reactions. A reaction
surge tank downstream from the reaction tank further ensures
that if any short circuiting of the reaction tank occurs,
precipitation of calcium salts (scale) will occur in the
surge tank rather than in the slurry piping. Slurry is
pumped back to the scrubber spray nozzles from the reaction
surge tank via two half-size slurry pumps. Part of the
slurry is bled to the thickener tank to prevent buildup of
waste by-product solids in the scrubber.
3-4
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3.2 DESIGN PARAMETERS
Unit 6 at the Paddy's Run Station is a 65 MW generator
with a maximum continuous output capability of 70 MW. At
peak load the gas flow from the boiler is 400,000 acfm at
335°F. This exhaust gas is handled by two absorber modules,
each 17 x 18 ft x 50 ft high overall. System design incor-
porates the use of an existing ESP operating at a particu-
late removal efficiency of 99.1 percent.
The solids content of the slurry leaving the absorber
ranges between 9.5 and 10.5 percent. The ratio of sulfite
to sulfate in the recirculating slurry ranges between 40 and
50 on a weight basis. Liquid to gas ratio (L/G) ranges
between 15 and 18 gal./lOOO ft of gas at 125°F per stage.
Slurry additive contains 20 to 30 percent solids and has a
pH of 12.6. Lime is added to the thickener tank to stabilize
the sludge that is formed. Lime consumption at that point
is about 100 Ib/ton of dry sludge solids generated. The
sludge is trucked and landfilled in a ten-acre borrow pit
that ranges from 20 to 30 feet in depth. Solids content of
the effluent from the thickener averages about 25 percent.
This material is then dewatered by vacuum filtration to form
a stabilized sludge containing 45 percent solids. An ex-
periment is planned in which the thickener effluent will be
mixed with dry fly ash and lime to form stabilized sludge
with a 45 percent solids content.
The liquid system operates in a closed-loop mode.
About 40 gallons of make-up water are added per Ib-mol of
3-5
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S0~ removed. Pressure drop across the absorber ranges from
11 to 12 in. H2O. Total pressure drop across the FGD system
is 15 to 16 in. H20. Two rotary drum filters, each having
an effective filtering area of 150 ft , are used to dewater
sludge. The filters utilize nylon cloth and do not require
a precoat. Each filter has a wet cake capacity of approxi-
mately 10 ton/hr. Operating parameters are summarized in
Tables 3.1. and 3.2.
3.3 INSTALLATION SCHEDULE
In 1970 LG&E requested Combustion Engineering, Inc. to
determine if their lime scrubbing system could be adapted to
the Paddy's Run Power Station. The unique aspect of this
station is that it is located near an Airco acetylene
manufacturing plant that generates a calcium hydroxide
sludge by-product that can be used as a scrubbing agent in
the FGO process. Laboratory pilot plant studies were conducted
in early 1971, and a process was developed and tested using
a prototype 12,000 acfm scrubber in June 1971. After the
successful completion of a 100-hour continuous test, Com-
bustion Engineering, Inc. was given a contract to design and
build a full-size system to control Boiler 6 at the Paddy's
Run Power Station (July 1971). On-site construction of the
FGD system was begun in June 1972 and completed in April
1973. Initial start-up occurred on April 5, 1973. No major
delays or start-up problems were indicated. System shake-
down was completed by July 1973.
3-6
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Table 3.1 SUMMARY OF DATA - SCRUBBER MODULES
Item
L/G ratio
gal./lOOO acf @ 125°F
Superficial gas
velocity, ft/sec
Module size, (2 modules)
Equipment intervals
Material of construction
Shell
Internals
15 - 18
8-10
17' x 18' x 50' high
Marble bed
Mild steel 2 1/2"
thick FRP flake
lining
316 stainless
3-7
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Table 3.2 SUMMARY OF DATA - FGD SYSTEM TANKS
Item
No. of units
Unit size and
capacity
Retention time
at full load
Temp. , °F
PH
Solids Cone. , %
Specific gravity
Material of
construction
Scrubber
recircu-
lation
tank
2
15' x 17' x 16'
high (16,300
gal. )
3 min
126
4.6-5.3
10
1.1
mild steel
with 1/2"
thick FRP
flake lining
Thickener
1
50' dia x 14'
high (205,500
gal.)
4.3 hr
100-110
5-6
10 in
20-24 out
1.1
mild steel
Reaction
tank
1
48' dia x 17'
high (210,000
gal.)
20 min
125
8
10
1.1
mild steel
Reaction
surge
tank
1
20' dia x 15'
high (35,200
gal.)
3 min
125
8
10
1.1
mild steel
Additive
slurry
tank
1
8 dia x 17'
high (6,400
gal.)
2 1/2 hrs
ambient
12.6
30
1.2
mild steel
I
CO
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3.4 COST DATA
The installed capital cost for this unit was,S3.7
million ($53/net KW). Annualized operating costs are pro-
jected to be $350,000 at a 60 percent load factor for the
unit, in addition to fixed charges (14 to 17%). Using a
fixed charge factor of 15 percent, the annualized cost is
calculated to be $905,000 or 2.5 mills/net KWH.
3-9
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4.0 FGD SYSTEM PERFORMANCE
4.1 START-UP PROBLEMS AND SOLUTIONS3
No major start-up problems were encountered that were
associated with the scrubbers. Problems with other system
components were described as follows:
Thickener Size - The original thickener was undersized
to handle the untreated slurry at full load. Preliminary
data had indicated that the slurry material entering the
thickener would contain more calcium sulfate than was actually
encountered. The slurry actually contained a high ratio of
calcium sulfite to calcium sulfate. Calcium sulfite crystals
are flakier and less dense than calcium sulfate crystals
and, having a high surface area, require a flocculant to aid
settling. The flocculant, Betz 1100, agglomerated the
calcium sulfite crystals so that settling was sufficiently
improved and a larger thickener did not have to be installed.
The flocculant was injected into the thickener at a rate
sufficient to maintain a 4-7 ppm concentration in the
thickener.
Carbide Lime Feed System - Some early problems were
experienced with plugging of the mesh strainer on the
Adapted from "Operational Status and Performance of the Louis-
ville FGD System at the Paddy's Run Station," R.P. Van Ness,
Louisville Gas and Electric Co., Nov. 2-7, 1974 and supplemented
with data obtained during plant visit.
4-1
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additive tank. This problem was solved by installing a
Rietz mechanical disintegrator in the carbide feed line to
the additive tank.
Mist Eliminator Wash System - The original mist elimi-
nator wash system consisted of rotating nonretractable wash
lances with 3/16-inch diameter nozzles every 6 inches. The
system would not efficiently clean the upper mist elimi-
nator. The nonretractable lances were replaced with re-
tractable half-track lances with oscillating 1/2 inch
nozzles. The larger solid stream of water from these
nozzles keeps the mist eliminators clean. At full load 200
gal./min of river water are required per scrubber for about
8 to 12 minutes every 8 hours for demister washing.
Scaling - At this plant scale formation does not occur
as long as both of the following conditions are met: 1) fly
ash must not constitute more than about 6 percent of the
slurry solids, and 2) slurry pH must be maintained between
8.0 and 9.5. Slurry pH is measured downstream from the
reaction tank. Additive lime is pumped to the reaction tank
from the additive slurry tank. Scaling potential does not
seem to be influenced by the oxygen content of the exhaust
gas which typically ranges between 6 and 9 percent.
On one occasion while burning low sulfur coal calcium
sulfite scale deposits began to accumulate on the upper bed
because the S02 concentration there was too low to keep the
bed pH less than 6.2. The scale was dissolved by temporar-
ily lowering the overall system pH.
4-2
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Damper Leakage - The FGD system can be bypassed by
means of louvered dampers. Deposits on these dampers were
found to prevent them from sealing completely so that leakage
through the dampers resulted in the formation of a visible
plume. By cleaning the dampers periodically the leakage was
maintained at a minimum, and the plume effectively suppressed,
4.2 PERFORMANCE TEST RUN
Efficiency tests on the FGD system were performed
during a 35-day demonstration period beginning October 26,
1973. The "B" scrubber module was operated continuously at
full load conditions throughout the test period, and an SO_
removal efficiency exceeding 85 percent was demonstrated.
4.3 PERFORMANCE PARAMETERS
System availability has been tabulated by LG&E since
April 1973. Availability is defined as the percent ratio of
FGD module operating hours to boiler operating hours. Since
the unit is a peak load boiler, boiler runs are frequently
short, and on several occasions the FGD system was bypassed
although it could have been operated. Thus, in some months
the availability figures would have been higher if the
system had been operated to its full potential. Table 4.1
lists the availability figures for both modules of the
system.
4.4 PROCESS MODIFICATIONS FOR FUTURE INSTALLATIONS
In the existing installation sludge filter cake con-
taining about 45 percent solids is trucked to a landfill
4-3
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Table 4.1 AVAILABILITY SUMMARY - PADDY'S RUN
Period
4/73
5/73
6/73
7/73
8/73
9/73
10/73
11/73
12/73
1/74
2/74
3/74
4/74
5/74
6/74
7/74
8/74
9/74
10/74
11/74
12/74
1/75
2/75
Boiler
operating
hours
320
265
255
240
330
390
690
720
190
0
142
54
52
167
5
306
31
43
245
122
0
0
0
FGD operating hours
Module A
58
29
0.25
50
175
332
338
252
84
0
0
0
0
0
0
156
15.5
0
245
0
0
0
0
Module B
179
172
15
50
211
281
649
720
148
0
0
0
0
0
0
248
24
0
245
0
0
0
0
Availability, %a
Module A
18
11
0.1
21
53
85
49
35
44
0
0
0
0
0
0
51
50
0
100
0
0
0
0
Module B
56
65
6
21
64
72
94
100
78
0
0
0
0
0
0
81
77
0
100
0
0
0
0
Availability is defined as the percent ratio of FGD module
operating hours to boiler operating hours.
4-4
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area and mixed with fly ash to produce a reasonably stable
material. In future installations it is anticipated that
the sludge handling system will be considerably modified.
It has been suggested that material from the thickener or
filter should be thoroughly mixed with appropriate quan-
tities of fly ash and lime at the power plant and pumped to
the landfill area. The fixated material would then solidify
to an environmentally acceptable material.
4-5
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APPENDIX A
PLANT SURVEY FORM
A-l
-------
PLANT SURVEY FORM
NON-REGENERABLE FGD PROCESSES
A. COMPANY AND PLANT FNFORMATION
1. COMPANY NAME
2 . MAIN OFFICE
3. PLANT MANAGER
4. PLANT NAME
5. PLANT LOCATION
Louisville Gas and Electric Co.
311 West Chestnut Street
Walter Carter
Paddy's Run
Rubbertown, Kentucky
6. PERSON TO CONTACT FOR FURTHER INFORMATION R.P. Van Ness
7. POSITION Manager-Environmental Affairs
8. TELEPHONE NUMBER
9 . DATE INFORMATION GATHERED
10. PARTICIPANTS IN MEETING
R. P. Van Ness
John Busik
T. W. Devitt
F. K. Zada
_(502) 582-3511 Ext. 216
July 9, 1974
AFFILCATION
_LG&E
U.S. EPA
PEDCO
PEDCO
These data were reported on July 9, 1974. Some data have been
updated in the text of the report.
A-2
5/17/74
-------
H. PLAIV11 DATA. (APPLIES TO ALL BOTLFRS AT Ti!!: I'LAl.'l).
CAPACITY, MW
SLRVLCE (I'.A.'JL:, PEAK)
FCI) SYSTLfl USIIID
1 & 2
30 each
PEAK
No
IX
3
65
PEAK
NO
)ILI:K no.
4
65
PEAK
No
5
65
PEAK
No
6
65
.JP.EAK
Yes
C. JlOlJJillJMT/^. COMPJ.i'JTL SECTIONS (C) THROUGH (K) I'Oi: KACJll
B01LLR HAVING AN FC.D SYSTJiM.
I. UOTLKR IDENTIFICATION NO.
2. MAXIMUM CONTINUOUS lli'.AV INPUT 810. M4_BTU/hr_
3. MAXIMUM CONTINUOUS GENERATING CAPACITY _70. . . ._ MW
4. MAXIMUM CONTINUOUS FLUC GAS RATK , ^PPfOX^ J_50 ,_000AcrM (i350_°r
5. noiLEK MANUFACTURUR Foster Wheeler
6. YEAR BOILER PLACED IN H1.RVIC1-: ..j-i^ .
7. I'.OLLKR SKRV1CK (UASI? LOAD, PKAK, ETC. ) PEAK
8. STACK IIJ: I GUT 250'
9. 1301 U;R OPERATJ ON HOURS/YEAR (1973) 36j57_
10. liOILER CAPACITY FACTOR * 5% (1974)
11. RATIO OF FLY ASH/BOTTOM ASH
8 to 1
FI.' YliAR
"IIK/YR
A-3
ri/!7/71
-------
D.
DATA
COAL ANALYSIS (as received)
GUV (UTU/LU.)
_13tOOO
S '. _^.r.§_
ASH ?. _15±J.
FULL OJ I, ANALYSIS (excJudc- f,L.iLt-up CuoJ)
GRADE
i • ft
A:. 11 ;.
f IIJ
9.4
AV( ,
12,400
3^71
13.8
i-:.
ATKOSPHER LC__EJ
1. APPLICABLE IIIHSSIOil KLGULAT fON!J
d) CURRi:iJT RLOUIREMEN'l'S
AQCR PRJ OR I.TY CLASS I F1CAT I ON
Ri:(;iJI,AT10N &. SECTION NO.
MAX. ALLOWABLE CM1S5JIONS
J.DS/MM BTU
h) KUTUKE Rli^UI RKfllJN'J'S ,
COMPI.1ANCK DA'J'E
REGULATION S, SECTION NO.
MAXIMUM AJ.I-OWAULi: i:,MISSJuNS
J,US/MM 15TLI
I'AHTIC'JLATJJS
.1
SO-,
. .1.2L -
_1
. APC Regs. of Jefferson Cnty
Dated 4/19/72
1.2
2. PLANT PROGRAM I-'OR PARTiCULATES COMPI, LANCE
In compliance
3. IT,ANT J'UOC.RAM FOR K()2 COMPLIANCE
, NO .fusther .compliance planned due.
... .Plant, being, a peaking facility.
A-4
-------
F . PART LCUI.ATE REMOVAL
1. TYPE
MANUFACTURER
H ECU .
EFFICIENCY: DESIGN/ ACTUAL
MAX. EMISSION RATE *
GK/SCF
LB/MMBTU
Res. Cot.
97.5/99.1
9-9.5
.05
C.E.
S02
2-9
.05G/SCF
1.2
DESIGN BASIS, LUJLFUR CONTENT
3.5
C, . DESULFUR I ZAT I ON SYSTEM UAT/\
1. PROCESS NAMii
jjime wet tail-end scrubbjer_.sy_st:ein
2. LICENSOR/DESIGNER NAME: .Combustion Engineering.
ADDRESS:
Pi.P.SON TO CONTACT:
TELEl-HOMi; NO. :
'./._Conn_. _
Peter_Maurin
^03-688-1911
"j. ARCH LTECTUKAL/ENGLNEERS, NAME: Z?-0^?6^^6^!0.?3
ADDRESS: Chicag_oi._I31linois. . . _ _.
PERSON TO CONTACT: Jack _Byrnes _
TELEPHONE NO.: 312-82_2-2_600
4. PRO.IECT CONSTRUCTION SCHEDULE: D/Yl E
<0 DATE OF PREPARATION OL' IJ1DS S-PKCS. ApprOX... _l^
10 DATE OF REQUEST FOR BIDS Dec. 1970
r;) DATE OF CONTRACT AWARD
d) DATE UN SITE CONSTRUCT.! ON UECAN
July .19 7_1_
June. 19.7.2.
<_•) DA'J'i: ON SITE CONSTRUCTION' rOMPLKTF.D Apri.LJJJ?!
[) DATE OF INITIAL, STARTUP 4/5/73
-------
5. LIST MAJOR DELAYS IN CONSTRUCTION SCHEDULE AND CAUSES;
No par"hi mil ay g .
6. NUMBER OF SO- SCRUBBER TRAINS USED
ji
7. DESIGN THROUGHPUT PER TRAIN, 7vCFM @ 350 °F
8. DRAWINGS: 1) PROCESS FLOW DIAGRAM AND MATERIAL BALANCE
2) EQUIPMENT LAYOUT
K. S02 SCRUBBING AGENT
1. TYPE Carbide Lime
2. SOURCES OF SUPPLY Airco, Inc.
3. CHEMICAL COMPOSITION (for each source)
Ca(OH)2 _i9±l_2_
SILICA _2_'_?_~fi-? _.
CALCIUM CARBONATE _}_~A . _. ... _.
MAGNESIUM OXIDE __J:
4. EXCESS SCRUBBING AGENT USKD ABOVE
STOIC1IIOMETRIC REQUIREMENTS
5. MAKE-UP WATER POINT OF ADDITION
MAKE-UP ALKALI POINT OF ADDITION _?9Z_-!°.%_S_9J!:i^i. from C^K?
Plant
A"6 r./17/7 4
-------
,J . SCrUWI»KR_ TRAIN SPKCIFICAT1ONS
1. bCKUBUKR MO. 1 (a) Two scrubbers in parallel.
TVPL (TOWKR/VGNTURI) . Tower
30-15/stage
8-12
L1OU ID/GAS RATIO, G/MCF @126°I'_
GAS VELOCITY THROUGH SCRUi3BiJR, FT/Si;C
MATlilUAf. OF CONSTRUCTION
'J'YI'i: Ol1 I.JNLNG
INTERNALS:
TYPL-: (FLOATING UIIl), MARIJLK BF,D, KTC. > _Marble.JBed
NUMmiR OF STACKS 2
TV PI; AND SUL; OF PACKING MATERIAL
PACKING TlirCKNKSS P
steel-rStainless
Fibre glass
Flake glass
GLi§ss_. marbles-1"
STACK (L>) 3"
Glass
316 stainless
MATI.R1AJ, OF CONSTRUCTION, PACK INC1,:
SUPPORTS: _. _
I. SCKUBBLR NO. 2 (a)
TYPK (TOV/IJR/VliNTURl)
LJQU1D/GAS RATIO, G/MCI1 (' °F
GAS VELOCITY THROUGH SCP.UUUKR, TT/SIIC'
HATURIAL OF CONSTRUCTION
•J'YPi: OF L.INHJG
INTERNALS:
TYPI: (FLOATINC; ui:u, HAKI-LL UF.IJ, I:TC.)
NUMIirU OI-1 STAGI.S _
TV PI: AND si XL: OF TALK INC MATI-JRIAL . _
;i) Sf rubber No. 1 is l:hc scrubber l:h.-it Llio Clue: (in<-.«is I i irsl
onLcr. Scrubber 2 (j.T nppl .icciblc) PoLlow? Sci:ubbcr No. I.
b) I-'or fJoatirui borl, ])acking l.hickncRS at ro-.l.
A-7
V I / '7.1
-------
PACKING THICKNESS PER STAGE(b)
MATERIAL OF CONSTRUCTION, PACKING:
SUPPORTS:
CLEAR WATER TRAY (AT TOP OF SCRUBBER)
TYPE
L/G RATIO NA
SOURCE OF WATER
DEMISTL:R
TYPE (CHEVRON, ETC.)
NUMBER OF PASSES (STAGES)
SPACE BETWEEN VANES
ANGLE OF VANES
TOTAL DEPTH OF DEMISTER
DIAMETER OF DEMISTER
DISTANCE BETWEEN TOP OF PACKING
AND BOTTOM OF DEMISTIJR
POSITION (HORIZONTAL, VERTICAL)
MATERIAL OF CONSTRUCTION
METHOD OF CLEANING
SOURCE OF WATER AND PRESSURE
FLOW RATE DURING CLEANINGS, GPM
Chevron
Two
45'
Rectangular
4'-5
Horizontal
Fibre Glass
Water Wash-River
River - 60 psi
100-200
FREQUENCY AND DURATION OF CLEANING 8-12 min/8 hours
REMARKS No problems of scaling or plugging.
5. REHEATER
TYPE (DIRECT, INDIRECT)
Direct
b) For floating bed, packing thickness at rest.
A-8
5/17/74
-------
DUTY, MMUTU/MU 10/Sc rubber. .....
HEAT TRANSFER SURFACE AREA SO. .FT ...7.7
TEMI'ERATURK Ol1 CAS: IN __126_ ._ . OUT . ..165
HEATING MEDIUM SOURCL ..Natura.l S3? ......
TEMPERATURE & PRESSURE _29 ........... ____
FLOW RATH — ___________ 1.I1/I1R
KKIIEATKR TUBES, TYPi: AMI)
MATKRJAL OF CONSTRUCTION ...N-A.-
KI:;ili:ATUI1 LOCATION WITH KLSl'KC'i TO L3J . Ml STKK _ Above
METHOD OF CLEANING _N?Bf__ ..... _________
FREQUKUCY AND DURATION OF CLEANING _________ ~..~
FLOW liATJ',1 OF CLEAtJFNlJ MEDIL.'.M .._!_.-. ______ L!i/H!<
RJIMAKKS ~ ~
6. SCUUUUUR TRAIN PRESSURE DUOP DATA LNCIILiS OF WATER
PARTICULATE SCRUHBliR _. . . - -._
S02 SCRUlllJIiR _ . 11-12
CLEAR V.'A'l'HR TRAY _. . - -
DEM1STER . 1.5 _
REHEATER _ .- ~._
PUCTUOKK 2. 5
'J'O'J'AL FC.IJ SVS'J'EM _. 15-16
A-9
-------
7.
8.
FRESH WATER MAKE UP FLOW RATES AND POINTS OF ADDITION
TO: DEMISTER Approx. 2500 gal ./scrubber/ 8 hrs
QUENCH CHAMBER - -
ALKALI SLURRYING - -
PUMP SEALS
OTHER
30-40 gallons/min.
5 qpm
TOTAL
Approx. 50 qpm ±
FRESH WATER ADDED PER MOLE OF SULFUR REMOVED 38 gal./lb mol
BYPASS SYSTEM
CAN FLUE GAS BE BYPASSED AROUND FGD SYSTEMS Yes
GAS LEAKAGE THROUGH BYPASS VALVE, ACFM Relatively small
K. SLURRY DATA
LIME/SLURRY MAKEUP TANK
PARTICULATE SCRUBBER EFFLUENT
HOLD TANK (a)
SO2 SCRUBBER EFFLUENT HOLD
TANK (a)
pll
12.6
NA
8-9.5
•1
o
Solids
20-30
NA
10±l/2
Capacity
(gal)
9000
NA
200,000
Hold up
time
1-2 hours
NA
30 min.
L. LIMESTONE MILLING AND CALCINING FACILITIES: INDICATE BOILERS
SEKVED BY THIS SYSTEM.
TYPE OF MILL (WET CYCLONT, ETC.)
NUMBER OF MILLS
CAPACITY PER MILL
RAW MATERIAL MESH SIZE
PRODUCT MESH SIZE
NA
T/IiR
A-10
5/17/74
-------
SLURRY CONCENTRATION IN MILL
CALCINING AND/OR SLAKING FACILITIES
SOURCE OF WATER FOR SLURRY MAKE UP OR
SLAKING TANK
M. DISPOSAL OF SPENT LIQUOR
1. SCHEMATICS OF SLUDGE & FLY ASH DISPOSAL METHOD
(IDENTIFY QUANTITIES OR SCHEMATIC)
2. CLARIFIERS (THICKENERS)
NUMBER I
DIMENSIONS 1
CONCENTRATION OF SOLIDS IN UNDERFLOW
3. ROTARY VACUUM FILTER
NUMBER OF FILTERS
CLOTH AREA/FILTER
CAPACITY
4.
22-24%
150 ft: /fiIter
Approx. 10 TON/HR (WET CAKE)
CONCENTRATION OF SOLIDS IN CAKE
35-45%
PRECOAT (TYPE, QUANTITY, THICKNESS)
REMARKS
None
SLUDGE FIXATION
POINT OF ADDITIVES INJECTION
FIXATION MATERIAL COMPOSITION
FIXATION PROCESS (NAME)
Thickener
Lime
Ours
FIXATION MATERIAL REQUIREMENT/TONS OF DRY SOLIDS UF SLUDGE
3-5%
A-ll
5/17/74
-------
ESTIMATED POND LIl'E, YRS.
CONCENTRATION OF SOLIDS IN FIXED SLUDGE 45
METHOD OF DISPOSAL OF FIXED SLUDGE Trucking
INITIAL SOLIDIFICATION TIME OF FIXED SLUDGE 30 days
SLUDGE QUANTITY DATA
POND/LANDFILL SIZE REQUIREMENTS, ACRE-FT/YR
IS POND/LANDFILL ON OR OFFSITE Landfill - offsite
TVPE OF LINER None
IF OFFSITE, DISTANCE AND COST OF TRANSPORT J:_Jl!le. ~ 50C/T
POND/LANDFILL DIMENSIONS AREA IN ACRES 10 approx.
DEPTH IN FEET 20-30
DISPOSAL PLANS; S1JORT AND LONG TERM Short
N. COST DATA
1. TOTAL INSTALLED CAPITAL COST
2. ANNUALIZED OPERATING COST _ $ 350,000
5/17/74
A-12
-------
177.
COST ELEMENTS
CAPITAL COSTS
SO- SCRUBBER TRAINS
2
LIMESTONE MILLING
FACILITIES
SLUDGE TREATMENT &
DISPOSAL POND
SITE IMPROVEMENTS
LAND, ROADS, TRACKS,
SUBSTATION
ENGINEERING COSTS
CONTRACTORS FEE
INTEREST ON CAPITAL
DURING CONSTRUCTION
ANNUAL! ZED OPERATING COST
FIXED COSTS
INTEREST ON CAPITAL
DEPRECIATION
INSURANCE & TAXES
LABOR COST
INCLUDING OVERHEAD
VARIABLE COSTS
RAW MATERIAL
UTILITIES
MAINTENANCE
INCLUDED IN
ABOVE COST
ESTIMATE
YES NO
DO CH
n n
m n
x LJ
E CD
13 n
ra
E CH
1 X 1
E n
QD rj
[xi n
x "1
fzi n
ESTIMATED AMOUNT
OR n6 OF TOTAL
INST/ALLED CAPITAL
COST
. . ^_ . ._
)
/
( 14 - 17%
.11
.. . — —
A-13
5/17/7-1
-------
4. COST r'ACTORS
a. ELECTRICITY
b. WATER
C. STEAM (OR FUEL FOR REHEATING)
d. FIXATION COST $/TON OF DRY SLUDGE
e. RAW MATERIAL PURCHASING COST $/TON OF DRY SLUDGE
f. LABOR: SUPERVISOR HOURS/WEEK WAGE
OPERATOR
OPERATOR HELPER
MAINTENANCE
O. MAJOR PROBLEM AREAS: (COKR05-.ION, PLUGGING, ETC.)
1. S02 SCRUBBER, CIRCUL7\TION TANK AND PUMPS.
a. PROBLEM/SOLUTION None (normal wear_and__tear)_
2. DEMISTER
PROBLEM/SOLUTION
3. REHEATER
PROBLEM/SOLUTION None
5/17/74
A-14
-------
4. VENTURI SCRUBBER, CIRCULATION TANKS AND PUMPS
PROBLEM/SOLUTION NA
5. I.D. BOOSTER FAN AND DUCT WORK
PROBLEM/SOLUTION No particular problem
6. LIMESTONE MILLING SYSTEM OR LIME SLAKING
PROBLEM/SOLUTION NA.
7. SLUDGE TREATMENT AND DISPOSAL
PROBLEM/SOLUTION No problem to date.
A-15
-------
8. MISCELLANEOUS AREA INCLUDING BYPASS SYSTEM
PROBLEM/SOLUTION Ngne.,... Leakage, of .loiuter.ed--dampers...
.n.Q£_serjLoiis._.(adjustments)..
P. DESCRIBE FACTORS WHICH MAY NOT MAKE THIS A REPRESENTATIVE
INSTALLATION _,.
DESCRIBE METHODS OF SCRUBBER CONTROL UNDER FLUCTUATING
LOAD. IDENTIFY PROBLEMS WITH THIS METHOD AND SOLUTIONS,
IDENTIFY METHOD OF pH CONTROL AND LOCATION OF pH PROBES,
Automatic _pH control ~_Cp_ntrql occurs after
reaction tank.
5/17/74
A-16
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APPENDIX B
PLANT PHOTOGRAPHS
B-l
-------
Photo No. 1 View away from Paddy's Run Power Station.
The large supply pile of carbide lime shows lightly
across the background of the picture.
Photo No. 2 View of Paddy's Run sludge disposal area in
borrow pit near highway.
B-2
-------
Photo No. 3 Carbide lime supply truck. The lime slurry
mix tank appears at the left side of the picture. The
Ohio River is in the background.
Photo No. 4
Run.
View looking down on the reaction tank at Paddy's
B-3
-------
Photo No. 5 Internal view of scrubber showing marble bed
and screened overflow pots.
Photo No. 6 View of scrubber switchgear building showing
conduit run for FGD system power supply.
B-4
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO
EPA-650/2-75-057-d
3 RECIPIENT'S ACCESSION NO.
4 TITLE AND SUBTITLE
Survey of Flue Gas Desulfurization Systems
Paddy's Run Station, Louisville Gas and Electric
5. REPORT DATE
August 1975
6 PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
8 PERFORMING ORGANIZATION REPORT NO
Gerald A. Isaacs
9 PERFORMING OR6ANIZATION NAME AND ADDRESS
PEDCo-Environmental Specialists, Inc.
Suite 13, Atkinson Square
Cincinnati, Ohio 45246
10 PROGRAM ELEMENT NO.
1AB013; ROAP 21ACX-130
11 CONTRACT/GRANT NO.
68-02-1321, Task 6d
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 C
Task Final; 7/74 - 7/75
OVER§D
14. SPONSORING AGENCY £ODE
15 SUPPLEMENTARY NOTES
. ABSTRACT
rep()rf gives results of B. survey of the flue gas desulfurization (FGD)
system on Unit 6 of Louisville Gas and Electric Co.'s Paddy's Run Power Station. The
closed-loop system, which was started up in April 1973, utilizes a slurry of carbide
lime in a marble-bed scrubber. The carbide lime, a waste by-product from a nearby
acetylene manufacturing plant, contains 90-92 percent calcium hydroxide, 2-2.5
percent silica, 3-8 percent calcium carbonate, and 0.1 percent magnesium oxide.
Sludge is stabilized by mixing thickener overflow with carbide lime before vacuum
filtration. The sludge, containing about 40 percent solids, is trucked to a nearby
10-acre borrow pit, used as a landfill area. The Paddy's Run Station is used
primarily to meet summer peaking loads. Boiler No. 6 is operated infrequently
be luse of its low thermal efficiency (heat rate is about 13,000 BtuAWhr). On
the basis of the performance at Paddy's Run, Louisville Gas and Electric Co.
is pursuing plans to install similar carbide lime FGD systems at other power
stations.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b IDENTIFIERS/OPEN ENDED TERMS
• ir Pollution
' Flue Gases
desulfurization
Scrubbers
iKur Dioxide
Ca'cium Oxides
Carbides
Coal
Combustion
Cost Engineering
Air Pollution Control
Stationary Sources
Marble-Bed Scrubber
Carbide Lime
Parti culate
c. COSATI Field/Group
13B 21D
21B
07A,07D 14A
07B
18 LJIsIRIfa ITION STATEMENT
Unlimited
19 SECURITY CLASS (This Report)
Unclassified
21 NO. OF PAGES
47
20 SECURITY CLASS (Thispage)
Unclassified
22 PRICE
EPA Form 2220-1 (9-73)
B-5
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