EPA-650/2-75-057-J
Octobei 1975
Environmental Protection Technology Series
RVEY
OF FLUE GAS
DESULFURIZATION SYSTEMS
REID GARDNER STATION, NEVADA POWER CO.
U.S. Environmental Protection Agency
Office of Research and Development
Washington, D. C. 20460
-------
EPA-650/2-75-057-J
SURVEY
OF FLUE GAS
DESULFURIZATION SYSTEMS
REID GARDNER STATION, NEVADA POWER CO.
by
Richard W. Gerstle and Gerald A. Isaacs
PEDCo-Environmenlal Specialists, Inc.
Suite 13, Atkinson Square
Cincinnati, Ohio 45246
Contract No. 68-02-1321, Task 6]
ROAP No. 21AXC-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
October 1975
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EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection
Agency and approved for publication. Approval does not. signify that
the contents necessarily reflect the views'and policies of the Environ-
mental Protection Agency, nor doe's mention ,of trade names or commer-
cial 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' Into7 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 unproved
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 2216! .
Publication No. EPA-650/2-75-057-J
11
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ACKNOWLEDGMENT
This report was prepared under the direction of Mr.
Timothy W. Devitt. The principal authors were Mr. Richard
W. Gerstle and Dr. Gerald A. Isaacs. Mr. Charles D. Fleming
was responsible for editorial review and preparation of
graphic materials.
Mr. Wade H. Ponder, former EPA Project Officer, had
primary responsibility within EPA for this project report.
Information and data on the plant operation were supplied by
Mr. David G. Barneby, Nevada Power Company, by Mr. R. S.
Sommer, Combustion Equipment Associates, Inc., and Mr. D. C.
Philp, Bechtel Corporation during and subsequent to the
plant survey visit.
The authors appreciate the efforts and cooperation of
everyone who participated in the preparation of this report.
111
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November 20, 1975
ERRATA
Page vii --At end of 8th line from bottom of page: change "have not"
to read "have."
Page B-5 --In 7th line of block 16. ABSTRACT: change "did not meet"
to read "met."
(Please make the above two changes in your copy of:
EPA-650/2-75-057-J, Survey of Flue Gas Desulfurization Systems;
Reid Gardner Station, Nevada Power Co. , October 1975)
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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
3.0 DESULFURIZATION SYSTEM 3-1
3.1 Process Description 3-1
3.1.1 Flue Gas Flow 3-1
3.1.2 Liquor Flow 3-4
3.2 Design Parameters 3-6
3.3 Installation Schedule 3-8
3.4 Cost Data 3-8
4.0 FGD SYSTEM PERFORMANCE 4-1
4.1 FGD Problems and Solutions 4-1
APPENDIX A PLANT SURVEY FORM A-l
APPENDIX B PLANT PHOTOGRAPHS B-l
V
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LIST OF FIGURES
Figure
3.1
3.2
Simplified Flow Diagram of FGD System,
Reid Gardner Station - Nevada Power
Company
Liquor Flow System - Reid Gardner FGD
System
Page
3-2
3-5
LIST OF TABLES
Table
2.1
3.1
Pertinent Data on Plant Design, Operation
and Atmospheric Emissions - Reid Gardner
Station
2-3
Typical Pressure Drop Across FGD Components 3-8
VI
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SUMMARY
Flue gas desulfurization (FGD) systems have been designed
and installed to control sulfur dioxide and particulate
emissions from two existing 125 MW generating units at the
Reid Gardner Station of Nevada Power Company (NPC). Two
additional 125 MW units, originally planned for installation
in 1976 and 1977, are to incorporate similar FGD equipment.
The installation of the second new unit has been indefinitely
postponed.
The FGD systems utilize a sodium carbonate scrubbing
process developed, designed and supplied by Combustion
Equipment Associates, Inc. (CEA) and its joint venture
partner, Arthur D. Little, Inc. (ADL). Bechtel Corp. performed
the architectural/engineering work for the systems. The
systems were placed in operation in April 1974, and have not
met S02 and particulate performance guarantees during the
first year of operation. Each system utilizes twin parallel
Venturis followed by an absorber tower. As of August 1,
1975, System 1 had operated for 3814 hours and System 2 had
operated for 2947 hours. Potential availabilities for the
systems seem to be near 100 percent, but the plant has not
had access to an adequate supply of trona, a sodium carbonate
-------
ore that constitutes the scrubbing medium. Alternate sodium
carbonate sources recently have been secured. Pertinent
operational data are summarized in the following table.
SUMMARY OF FGD DATA, REID GARDNER UNITS 1 AND 2
Unit rating, MW (net)
Fuel
Gross heating value, BTU/lb
Ash, percent
Sulfur, percent
FGD process design
Process
New or retrofit
Start-up date
FGD modules
Efficiency, percent
Particulates
Scrubber and multicyclone
so2
Make-up water, gpm/MW
Disposal
Unit cost, $/KW (net)
110'
Coal
12,500
9
0.6
Combustion Equipment
Associates Inc./
Arthur D. Little, Inc.
Aqueous sodium carbonate
scrubbing
Retrofit
April 1974
One per unit
99+
90+
1.3
Evaporation ponds
50
Vlll
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1.0 INTRODUCTION
The Industrial Environmental Research Laboratory (formerly
Control Systems Laboratory) of the U. S. Environmental
Protection Agency (EPA) has initiated a study to evaluate
the performance characteristics and degree of reliability of
flue gas desulfurization (FGD) systems on coal-fired utility
boilers in the United States. This report on the Reid
Gardner Station of Nevada Power Company (NPC) is one of a
series of reports on such systems. This report presents
data on key process design and operating parameters, describes
the major start-up and operational problems encountered at
the facility and the steps taken to alleviate such problems,
and identifies the total installed and annualized operating
costs.
This report is based upon information obtained during a
plant inspection on October 8, 1974, and on data provided by
NPC and Combustion Equipment Associates, Inc. (CEA).
Section 2.0 presents pertinent data on facility design
and operation. 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
The Reid Gardner Station of NPC is located near Moapa,
Nevada, about 50 miles northeast of Las Vegas. This is a
sparsely populated, arid part of Nevada. The station has
two electric power generating units, (Reid Gardner Units 1
and 2) each rated at 125 MW (gross).
Both units are identical in design and operate under
base load conditions. The pulverized-coal-fired boilers
were manufactured by Foster-Wheeler. Unit No. 1 was placed
in service in 1965 and Unit No. 2 started operation in 1968.
Utah coal is burned, having an average gross heating value
of 12,500 BTU/lb and average ash and sulfur contents of 9
and 0.6 percent, respectively.
Reid Gardner Unit 3 is presently under construction
with a start-up date scheduled for 1976. Its design capacity
is 125 MW. Reid Gardner Unit 4 was in the planning stage
but has been indefinitely postponed.
Enforcement action by Clark County in 1970 led NPC to
contract with Bechtel Corporation for design and instal-
lation of an FGD system. Bids for FGD systems were solicited
in 1971. CEA was the only vendor that proposed a soluble
reagent (sodium carbonate) scrubbing medium, and they were
2-1
-------
selected for the work. In early 1972, CEA/ADL designed,
built and operated a 7000 to 9000 acfm pilot unit at the
plant to better define operating variables using less
expensive trona as a source of sodium carbonate. Two full-
scale scrubbers were placed in service in April 1974. Table
2.1 summarizes pertinent data for the boilers and the
atmospheric emissions.
Clark County, Nevada limits SO- emissions to 0.15 Ib/MM
BTU input. The State of Nevada limits SO- emissions to 0.21
Ib/MM BTU input.
2-2
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Table 2.1 PERTINENT DATA ON PLANT DESIGN, OPERATION AND
ATMOSPHERIC EMISSIONS - REID GARDNER STATION
Boiler data
Rating generating capacity, MW (gross)3
Average capacity factor (1973), %
Boiler manufacturer
Year placed in service
Maximum coal consumption, ton/hr
Maximum heat input, MM BTU/hr
Stack height above grade, ft
Flue gas rate - maximum, acfm
Flue gas temperature, °F
Emission controls
Particulate
so2
Particulate emission rate
Allowable, Ib/MM BTU
Actual, Ib/MM BTU
SO- emission rate
Allowable, Ib/MM BTU
Actual, Ib/MM BTUC
1
125
73
F-W
1965
47.5
1187.5
200
473,000
350
Multicyclone and
venturi scrubber
Venturi scrubber
and absorber tower
0.12
0.055
0.15
0.115
2
125
73
F-W
1968
47.5
1187.5
200
473,000
350
Multicyclone and
venturi scrubber
Venturi scrubber
and absorber tower
0.12
0.55
0.15
0.115
N)
I
LJ
Net without scrubber is 112 MW. With scrubber and reheat, net is 106.5 MW.
Calculated value.
Based on 84% removal efficiency (310 ppm inlet, 50 ppm outlet) and a 0.72 Ib/MM BTU
inlet concentration.
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3.0 DESULFURIZATION SYSTEM
3.1 PROCESS DESCRIPTION
The sodium carbonate based FGD systems on Reid Gardner
Units 1 and 2 were placed in operation in April 1974. The
design of these systems was based on data gathered from the
operation of an 8000 acfm pilot plant which operated at the
Reid Gardner Station during 1971 and 1972.
The FGD system on each boiler consists of a single
module, designed to handle 473,000 acfm of gas at 350°F.
The module is made up of two parallel variable throat
venturi scrubbers followed by a single-stage perforated
plate washing tower. The FGD modules on both boilers share
a common trona (sodium carbonate ore) storage and beneficia-
tion system. Beneficiation consists of settling out in-
solubles (mainly sand) in a clarifier. Bypassing of each
module is possible through the use of leaf and guillotine
isolation dampers.
3.1.1 Flue Gas Flow
As shown in Figure 3.1, the hot flue gas from the
boiler passes through an existing mechanical collector
(multicyclone) where about 75 percent of the fly ash is
removed. The flue gas is then drawn through a 3000 hp fan
3-1
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DESIGN
5°F AM3IENT
67,000 acfm AIRi ,A
u>
I
NJ
473,000 acfm
350°F
ASH
EVAPORATION
t
SETJL.JNG
r
ASH REKOVAL
SYSTE!':
A
WATE
MUDC
STORAGE
TANK
I
COOLING
TO'.-JEiiS
WAT
R FROM
Y RIVER
STr
I
BYPASS
DAMPER ;
^
•) (f^
f ISOLATION ]
( DAMPER, 169°F ill9°F
' 486,000 acfm
X
3000 hp
ISOLATION BOOSTER
DAMPERS /— ,FAN
^ ^^ 1 1
,.., — A ID AD AM ri
PECH^CAL ^SuRis
| COLLECTOR \ /
'
i - *..'
BOILER £ E
•S «
i_j
TRO.NA SILO *°
pH 11
MIXING TANK g:;i V^
v ^'|g
CLARIFIER — *J
\x
<:
' 'S1^
474 psia
476.7 Ib/min
364,400 acfm
j
/^
DEMI
\
k
l}
«E
i
"1
'j
•>
\.
STER
~TRAT
/
f« 5
•z.
LiJ
31
Q.
cn
1 °
1 0
VENTURI
RECYCLE
TANK
^LS
* ' f^ \ _
ER FROM
WELLS
^ PO
NEUTRAL
TA
ST-
[ZAT
NK.
ION
Y ^
UJ ,
CJ3
o:
^ pH 11
•^ MAKE-UP WATER FROM ASH POND
3_ . '•* . 129 gpm 1
o> • J6 gpm
0 ' 4r
ro TRAY
\ /RECYCLE
\X TANK
[ALKALI
'I : SEiTLING FVAPOWTTf^J
pH-7
50 gpm
POND POND
Figure 3.1 Simplified flow diagram of FGD system, Reid Gardner Station -
Nevada Power Company.
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after which it splits into two streams and enters the twin
throat venturi scrubber. Here the hot flue gas is quenched
with circulated scrubbing liquor sprayed from tangential
nozzles located on the walls of the venturi. The gas-liquid
mixture then passes through the venturi throats and exits
into a sump, where the reduction in velocity causes the
liquor droplets to fall and separate from the gas stream. A
liquid-to-gas ratio (L/G) of 10 gal./lOOO acf of gas at
1.30°F and a pressure drop of about 15 inches of water are
maintained in the venturi for efficient removal of SO_ and
particulates. The rectangular venturi throat opening is 18
inches wide by 18 feet long. The scrubbed gas at a tempera-
ture of 130°F then tangentially enters the cylindrical
droplet separator tower. The centrifugal force created by
the tangential flow causes the finer droplets to coalesce
near the tower's wall and separate from the gas stream. The
scrubbed gas rises through the tower and bubbles through
3/16 in.-diameter holes in a single sieve tray. The tray is
flooded with clear water from the ash pond at a rate equiv-
alent to 1 gpm per 1000 acfm of gas. This tray is inter-
mittently washed with fresh water sprayed against the tray
bottom. More SO- is absorbed in the sieve tray and the pH
of the tray liquid drops from 6.2 to about 5. The cleaned
gas continues up the tower and passes through a single-pass,
horizontal radial vane-type mist eliminator where entrained
liquid droplets are removed. The vanes are type 316L stainless
steel. No demister washing is provided.
3-3
-------
In or.de.r to give buoyancy to the gas and to prevent
condensation on the duct and stack walls, the gas is re-
heated by direct mixing with hot air. This hot air is
generated by drawing ambient air through a separate fan and
indirectly heating it in a finned tube heat exchanger using
steam. The combined gas stream enters a 200-foot tall stack
and is.discharged to the atmosphere.
3.1.2 Liquor Flow
The FGD system water is supplied from the ash settling
pond (see Figure 3.1). This water is originally supplied to
the cooling towers from wells and from the Muddy River.
Trona, a low grad ore containing 60 percent sodium carbonate,
20 percent sodium chloride, 10 percent insolubles, 10 percent
sulfates and inert dissolved solids, is normally used as the
SO- scrubbing agent. Trona is shipped to the Reid Gardner
Station in powdered form. The trona is transferred pneumatically
to a silo having a 3-day storage capacity. From there it is
conveyed to a slurry tank and mixed with water from the ash
ponds to dissolve the sodium carbonate. The slurry, containing
such impurities as sand and sodium chloride, is mixed with a
portion of the supply water and is pumped to a clarifier
where insoluble impurities settle out. The clarified sodium
carbonate liquor is injected into the venturi recirculation
loop.. The remainder of the make-up water (pH 11) is injected
into the absorber circuit via the tray recycle tank. Slowdown
from the venturi recycle tank is mixed with the alkaline
3-4
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clarifier underflow stream and adjusted to pH 7 in the post-
neutralization tank. The spent liquor from the post-neutra-
lization tank amounts to about one percent of the recycle
liquor flow through the venturi and absorber. The spent
liquor is pumped to a 6-acre ash settling pond, and the
overflow from this pond flows to a 45-acre evaporation pond.
No liquor is recycled to the modules from these ponds. This
method is appropriate for the disposal of spent liquor in
Nevada because of the low relative humidity in that area.
All make-up water is supplied from the ash settling pond.
3.2 DESIGN PARAMETERS
Design details of this scrubbing system are proprietary
to CEA. The system chemistry is based on the following
reactions:
Na2S03 + SO2 + H20 -»• 2NaHSO3
The first reaction predominates so that there is little
NaHSO, in the absorber effluent. Alkaline constituents in
the make-up water entering the sieve tray also aid the
absorption of S02 . A pH of approximately 6.2 is maintained
in the absorber inlet liquor. It is reported that 0.8 to
0.9 moles of Na2C03 are used per mole of S02 removed.
Make-up solution is fed at a rate of about 50 gpm into
the venturi recirculation loop. Within this loop, about
5000 gpm of liquor (L/G=10) , is injected into the two venturi
scrubbers where fly ash and some SO- is captured. A pressure
3-5
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drop of about 15 inches of water occurs across the venturi
at a throat velocity of approximately 165 ft/sec. The liquor
is partially separated from the flue gas in the lower portion
of the '30-foot diameter perforated plate tower where the gas
velocity is reduced to approximately 11 ft/sec. Liquor from
the bottom of this tower flows to a recirculation tank. The
underflow from this tank is mixed with fresh solution and
recycled to the venturi scrubbers. Underflow from the
recirculation tank which amounts to-approximately 50 gpm
(1%) is bled off to the ash settling pond.
Flue gas passing upward through the perforated plate at
a temperature of about 130°F is contacted with liquor which
is recirculated at a rate of 600 gpm. Wash water from the
tray recycle system is sprayed intermittently against the
bottom of this tray to prevent fly ash accumulation and to
provide make-up water to the venturi recycle loop.
The venturi throats are fabricated of Incoloy 825 and
the balance of the system is constructed of rubber-lined
mild steel. The demisters are fabricated from 316L stain-
less steel.
Pressure drops through the various system components
are shown in Table 3.1.
3-6
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Table 3.1 TYPICAL PRESSURE DROP ACROSS FGD COMPONENTS
Equipment
Venturi
Perforated Tray
Demister
Ductwork
TOTAL
Pressure
inches of
15
3
0.5
1.5
drop,
water
20
3.3 INSTALLATION SCHEDULE
A request for bids for design and installation of an
FGD system was issued by NPC in mid-1971, and a contract was
awarded to CEA in late 1971. A pilot plant was built and
operated in early 1972 and detailed engineering and design
were completed during that year. Construction started on
both modules in December 1972. The systems were started in
early 1974 and were in operation by March and April of that
year.
3.4 COST DATA
Detailed cost breakdowns are not available. The two
scrubbing systems along with all raw material handling and
pond equipment cost $11,000,000 or $50/KW (net). Operating
costs have not yet been tabulated due to limited operation.
3-7
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4.0 FGD SYSTEM PERFORMANCE
Since start-up in early 1974, both modules at the- Reid
Gardner Station have performed satisfactorily. However,
because of difficulties in obtaining a sufficient quantity
of trona, the operation of the modules has been subjected to
frequent interruptions. The FGD system has periodically
been bypassed to conserve trona. As of August 1, 1975,
Module 1 had operated for 3814 hours and Module 2 had
operated for 2947 hours.
4.1 FGD PROBLEMS AND SOLUTIONS
As noted above, the major problem in the continuous
operation of the FGD modules has been the lack of an adequate
supply of trona. In order to solve this problem, various
alternate sources of sodium carbonate have been used and the
present absorbent supply is made up of numerous small supplies,
The system had the usual start-up problems such as
rubber liners on recirculation lines becoming loose due to
poor fabrication, freeze-up of instruments and plugging of
control valve bypass lines. Another minor problem included
excessive leakage in the recirculation pumps' seals. Also
mechanical failure problems were experienced with the.
4-1
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guillotine dampers, which were later resolved with redesigned
drive train components.
An intensive evaluation of problems is not possible due
to the fairly brief operating period. However, the sim-
plicity inherent in an open-loop soluble system will naturally
minimize operating difficulties. The overall water loop for
the plant is closed now that the scrubbers are operational.
The scrubber evaporation has reduced the net amount of water
going to the evaporation ponds as cooling tower blowdown -so
that the evaporation pond level is now stable and no water
is running out of the pond into any other groundwater systems.
4-2
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APPENDIX A
PLANT SURVEY FORM
A-l
-------
PLANT SURVEY FORM3
NON-REGENERABLE FGD PROCESSES
A. COMPANY AND PLANT INFORMATION
1. COMPANY NAME Nevada Power Company
2. MAIN OFFICE P.O. Box 230. Las Vegas. Nevada 89151
3. PLANT MANAGER A.T. (Al) Perry
4. PLANT NAME Reid Gardner Station
5. PLANT LOCATION Moapa, Nevada 89025
6. PERSON TO CONTACT FOR FURTHER INFORMATION P.G. (Dave) Barneby
7. POSITION Production Mechanical Engr.
8. TELEPHONE NUMBER (702) 385-5631
9. DATE INFORMATION GATHERED Form Completed Sept.23,1974
10. PARTICIPANTS IN MEETING AFFILIATION
Dave Barneby
Terry Levitt Nevada Power
W. H. Ponder U.S. EPA
John Busik U.S. EPA
R.W. Gerstle PEDCo
F.K. Zada PEDCo
These data were obtained from Nevada Power Co. on September
23, 1974. Some of the data have been updated in the text of the
report.
A-2 5/17/74
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B. PLANT DATA. (APPLIES TO ALL BOILERS AT THE PLANT).
C.
CAPACITY, MW
SERVICE (BASE, PEAK)
FGD SYSTEM USED
BOILER NO.
1
120
Base
, Throw
Sodium
2
120
Base
Away
Carbonat
a
BOILER DATA. COMPLETE SECTIONS (C) THROUGH (R) FOR EACH
BOILER HAVING AN FGD SYSTEM.
1. BOILER IDENTIFICATION NO. Reid Gardner No. 1
2. MAXIMUM CONTINUOUS HEAT INPUT H58 MM BTU/IIR
3. MAXIMUM CONTINUOUS GENERATING CAPACITY 126 MW (Gross)
MAXIMUM CONTINUOUS FLUE GAS RATE. 473,000 ACFM @ 350 °F
BOILER MANUFACTURER Foster Wheeler
YEAR BOILER PLACED IN SERVICE 1965
7. BOILER SERVICE (BASE LOAD, PEAK, ETC.) Base Load
8. STACK HEIGHT 20°
9. BOILER OPERATION HOURS/YEAR (1973) 7032;06
10. BOILER CAPACITY FACTOR * 73%
11. RATIO OF FLY ASH/BOTTOM ASH 80/20
* DEFINED AS: KwH GENERATED IN YEAR
MAX. CONT. GENERATED CAPACITY IN KW x 8760 HR/YR
A-3
5/17/74
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D. FUEL DATA
1. COAL ANALYSIS (as received)
GHV (BTU/LB.)
S %
ASH %
MAX.
12,900
0.7
. 12
MIN.
12,000
0.4
6
AVG.
12,500
0.55
9
2. FUEL OIL ANALYSIS (exclude start up fuel)
GRA'DE
s %
ASH %
E. ATMOSPHERIC EMISSIONS
1. APPLICABLE EMISSION REGULATIONS
a) CURRENT REQUIREMENTS
AQCR PRIORITY CLASSIFICATION
REGULATION & SECTION NO.
MAX. ALLOWABLE EMISSIONS
LBS/MM BTU
b) FUTURE REQUIREMENTS,
COMPLIANCE DATE
REGULATION & SECTION NO.
MAXIMUM ALLOWABLE EMISSIONS
LBS/MM BTU
PARTICULATES
SO-
Clark County
Less than
Ring. 1 0.12
Clark Coui
0.15
New Plants
Clark County
Ringleman 0
New Plants
Clark County
0.15
2. PLANT PROGRAM FOR PARTICULATES COMPLIANCE Completed
3. PLANT PROGRAM FOR SO2 COMPLIANCE
Completed
A-4
5/17/74
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F. PARTICULATE REMOVAL
1. TYPE
MANUFACTURER
MECH.
Research
Co.
/ACTUAL 88/75
* LB/HR
GR/SCFD .7940
T.R/MMRTI1
E.S.P.
FGD
Comb. Equip
Assoc.
0.0197
0.055
DESIGN BASIS, SULFUR CONTENT
1.0%
G. DESULFURIZATION SYSTEM DATA
1. PROCESS NAME
2. LICENSOR/DESIGNER NAME:
ADDRESS:
PERSON TO CONTACT:
TELEPHONE NO.:
Throw away sodium carbonate
Combustion Equipment Associates
555 Madison Ave.. N.Y., N.Y.
R. S. Sommer
(212) 980-3700
3. ARCHITECTURAL/ENGINEERS, NAME: Bechtel Power Corp.
ADDRESS: Norwalk, California
PERSON TO CONTACT: D.C. Philp
TELEPHONE NO.: (213) 923-9761 Ext. 284
DATE
1971
4. PROJECT CONSTRUCTION SCHEDULE:
a) DATE OF PREPARATION OF BIDS SPECS.
b) DATE OF REQUEST FOR BIDS 1971
C) DATE OF CONTRACT AWARD 1971
d) DATE ON SITE CONSTRUCTION BEGAN Dec. 1972
e) DATE ON SITE CONSTRUCTION COMPLETED 1974
f) DATE OF INITIAL STARTUP April 1974
g) DATE OF COMPLETION OF SHAKEDOWN 1974
*At Max. Continuous Capacity
A-5
5/17/74
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6
7
8
LIST MAJOR DELAYS IN CONSTRUCTION SCHEDULE AND CAUSES:
Design changes
Additional pilot plant testing
Material delivery
Design errors
Labor disputes
Subcontractor delays
NUMBER OF S02 SCRUBBER TRAINS USED 1
DESIGN THROUGHPUT PER TRAIN, ACFM @ 350°F 473,000
DRAWINGS: 1) PROCESS FLOW DIAGRAM AND MATERIAL BALANCE
2) EQUIPMENT LAYOUT
H. SO2 SCRUBBING AGENT
1. TYPE
2 . SOURCES OF SUPPLY
5
6,
Pure or Impure
Sodium Carbonate
Morrison & Weatherly
Kerr McGee Chem., FMC Corp.,
3. CHEMICAL'COMPOSITION (for each source) Stauffer Chem.
SILICATES
SILICA
CALCIUM CARBONATE
MAGNESIUM CARBONATE
EXCESS SCRUBBING AGENT USED ABOVE
STOICHIOMETRIC REQUIREMENTS
MAKE-UP WATER POINT OF ADDITION
MAKE-UP ALKALI POINT OF ADDITION
Max. '10% sand
Max. 10% sand
NA
NA
Tray
Venturi
A-6
5/17/74
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J. SCRUBBER TRAIN SPECIFICATIONS
1. SCRUBBER NO. 1
TYPE (TOWER /VENTURI) Venturi
LIQUID/GAS RATIO, G/MCF <§ 350°F 10
GAS VELOCITY THROUGH SCRUBBER, FT/SEC (15" AP)
MATERIAL OF CONSTRUCTION Incolloy 825
TYPE OF LINING Rubber (Tri-Flex)
Bottom
INTERNALS:
TYPE (FLOATING BED, MARBLE BED, ETC.) *?A
NUMBER OF STAGES NA
TYPE AND SIZE OF PACKING MATERIAL NA
PACKING THICKNESS PER STAGED'
MATERIAL OF CONSTRUCTION, PACKING: NA
SUPPORTS:
SCRUBBER NO. 2 *a'
TYPE (TOWER/VENTURI)
LIQUID/GAS RATIO, G/MCF @ °F
GAS VELOCITY THROUGH SCRUBBER, FT/SEC .
MATERIAL OF CONSTRUCTION
TYPE OF LINING
INTERNALS:
TYPE (FLOATING BED, MARBLE BED, ETC.)
NUMBER OF STAGES
TYPE AND SIZE OF PACKING MATERIAL
a) Scrubber No. 1 is the scrubber that the flue gases first
enter. Scrubber 2 (if applicable) follows Scrubber No. 1.
b) For floating bed, packing thickness at rest.
A-7 5/17/74
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4.
PACKING THICKNESS PER STAGE
MATERIAL OF CONSTRUCTION, PACKING:.
SUPPORTS:.
CLEAR WATER TRAY (AT TOP OF SCRUBBER)
TYPE
L/G RATIO
SOURCE OF WATER
DEM1STER
TYPE (CHEVRON, ETC.)
NUMBER OF PASSES (STAGES)
SPACE BETWEEN VANES
ANGLE OF VANES
TOTAL DEPTH OF DEMISTER
DIAMETER OF DEMISTER
Sieve - 3/8" holes
1 gal/1000 acfm g 350°F
Ash pond
Radial vane
Air foil
30
DISTANCE BETWEEN TOP OF PACKING
AND BOTTOM OF DEMISTER
POSITION (HORIZONTAL, VERTICAL)
MATERIAL OF CONSTRUCTION
METHOD OF CLEANING
SOURCE OF WATER AND PRESSURE
FLOW RATE DURING CLEANINGS, GPM
foA
Horizontal
SS 316L
None
None
None
FREQUENCY AND DURATION OF CLEANING None
REMARKS 3 concentric rings of vanes w/gutter collectors
at outer edges.
5. REHEATER
TYPE (DIRECT, INDIRECT)
Indirect
b) For floating bed, packing thickness at rest.
A-8
5/17/74
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DUTY, MMBTU/HR
HEAT TRANSFER SURFACE AREA SQ.FT
TEMPERATURE OF GAS: IN OUT +50°F @ 32° ambient
HEATING MEDIUM SOURCE Boiler Secondary Super-
heater
TEMPERATURE & PRESSURE
FLOW RATE LB/HR
REHEATER TUBES, TYPE AND
MATERIAL OF CONSTRUCTION Aerofin - Extended Surf.
REHEATER LOCATION WITH RESPECT TO DEMISTERFollowinq
METHOD OF CLEANING None
FREQUENCY AND DURATION OF CLEANING None
FLOW RATE OF CLEANING MEDIUM None LB/HR
REMARKS
6. SCRUBBER TRAIN PRESSURE DROP DATA INCHES OF WATER
PARTICULATE SCRUBBER
S02 SCRUBBER
CLEAR WATER TRAY +3
DEMISTER + -5
REHEATER Nil
DUCTWORK +1'5
TOTAL FGD SYSTEM +20
A-9 5/17/74
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7.
8.
FRESH WATER MAKE UP FLOW RATES AND POINTS OF ADDITION
TO: DEMISTER None
QUENCH CHAMBER None
ALKALI SLURRYING
PUMP SEALS
OTHER
"20 qpm avg. 53 qpm max.
I 6 gpm
Wash tray 135 gpm
TOTAL
max. 190 gpm per unit
NA
FRESH WATER ADDED PER MOLE OF SULFUR REMOVED
BYPASS SYSTEM
CAN FLUE GAS BE BYPASSED AROUND FGD SYSTEMS Yes, @ 100% load
GAS LEAKAGE THROUGH BYPASS VALVE, ACFM Negligible
K. SLURRY DATA
LIME/LIMESTONE SLURRY MAKEUP TANK
PARTICULATE SCRUBBER EFFLUENT
HOLD TANK (a)
SO2 SCRUBBER EFFLUENT HOLD
TANK (a)
pH
%
Solids
Capacity
(gal)
Hold up
time
L. LIMESTONE MILLING AND CALCINING FACILITIES: INDICATE BOILERS
SERVED BY THIS SYSTEM.
TYPE OF MILL (WET CYCLONE, ETC.)
NUMBER OF MILLS
CAPACITY PER MILL
RAW MATERIAL MESH SIZE
PRODUCT MESH SIZE
A-10
T/HR
5/17/74
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Mixing tank
Ash pond
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 2 clarifying ponds
DIMENSIONS 6 acres, 8 acres
CONCENTRATION OF SOLIDS IN UNDERFLOW
ROTARY VACUUM FILTER
NUMBER OF FILTERS
CLOTH AREA/FILTER
CAPACITY
NA
.TON/HR (WET CAKE)
CONCENTRATION OF SOLIDS IN CAKE
PRECOAT (TYPE, QUANTITY, THICKNESS)
REMARKS
4.
SLUDGE FIXATION
POINT OF ADDITIVES INJECTION
FIXATION MATERIAL COMPOSITION
FIXATION PROCESS (NAME)
None
FIXATION MATERIAL REQUIREMENT/TONS OF DRY SOLIDS OF SLUDGE
A-ll
5/17/74
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ESTIMATED POND LIFE, YRS.
CONCENTRATION OF SOLIDS IN FIXED SLUDGE
METHOD OF DISPOSAL OF FIXED SLUDGE
INITIAL SOLIDIFICATION TIME OF FIXED SLUDGE
5. SLUDGE QUANTITY DATA
POND/LANDFILL SIZE REQUIREMENTS, ACRE-FT/YR
IS POND/LANDFILL ON OR OFFSITE On-site
TYPE OF LINER ' Natural -clay
IF OFFSITE, DISTANCE AND COST OF TRANSPORT
POND/LANDFILL DIMENSIONS AREA IN ACRES 45-acre evaporation
DEPTH IN FEET. pond
DISPOSAL PLANS; SHORT AND LONG TERM
N. COST DATA
1. TOTAL INSTALLED CAPITAL COST $11,000,000
2. ANNUALIZED OPERATING COST .
A-12 5/17/74
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3.
COST BREAKDOWN
COST ELEMENTS
CAPITAL COSTS
S02 SCRUBBER TRAINS
LIMESTONE MILLING
FACILITIES
SLUDGE TREATMENT &
DISPOSAL POND
SITE IMPROVEMENTS
LAND, ROADS, TRACKS,
SUBSTATION
ENGINEERING COSTS
CONTRACTORS FEE
INTEREST ON CAPITAL
DURING CONSTRUCTION
ANNUALIZED 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
ED ED
ED ED
ED a
ID
ED
ED
ED
ED
ED
ED
ED
ED
ED
ED
ED
1
a
ED
ID
a
ED
ED
ED
a
ED
1
a
ESTIMATED AMOUNT
OR % OF TOTAL
INSTALLED CAPITAL
COST
A.
B.
A-13
5/17/74
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4- COST FACTORS
a. ELECTRICITY
b. WATER
C. STEAM (OR FUEL FOR REHEATING)
d. FIXATION COST
e. RAW MATERIAL PURCHASING COST
f. LABOR: SUPERVISOR
OPERATOR
OPERATOR HELPER
MAINTENANCE
$/TON OF DRY SLUDGE
$/TON' OF DRY SLUDGE
_ HOURS/WEEK WAGE
O. MAJOR PROBLEM AREAS: (CORROSION, PLUGGING, ETC.)
1. SO- SCRUBBER, CIRCULATION TANK AND PUMPS.
a.
PROBLEM/SOLUTION.
2. DEMISTER
PROBLEM/SOLUTION.
3. REHEATER
PROBLEM/SOLUTION.
A-14
5/17/74
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4. VENTURI SCRUBBER, CIRCULATION TANKS AND PUMPS
PROBLEM/SOLUTION
5. I.D. BOOSTER FAN AND DUCT WORK
PROBLEM/SOLUTION
6. LIMESTONE MILLING SYSTEM OR LIME SLAKING
PROBLEM/SOLUTION
7. SLUDGE TREATMENT AND DISPOSAL
PROBLEM/SOLUTION
A-15 5/17/74
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8. MISCELLANEOUS AREA INCLUDING BYPASS SYSTEM
PROBLEM/SOLUTION
P. DESCRIBE FACTORS WHICH MAY NOT MAKE THIS A REPRESENTATIVE
INSTALLATION
Q. 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.
A-16 5/17/74
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R.
COMPUTATION OF FGD SYSTEM AVAILABILITY FACTOR
BOILER RATING OR MAXIMUM CONTINUOUS CAPACITY, MW
PERIOD
MONTH/YEAR
FLUE GAS DESULFURIZATION MODULES
MODULE A
DOWN DUE TO
BOILER
(HRS)
MODULE
(HRS)
MODULE B
DOWN DUE TO
BOILER
(HRS)
MODULE
(HRS)
MODULE C
DOWN DUE TO
BOILER
(HRS)
MODULE
(HRS)
MODULE D
DOWN DUE TO
BOILER
(HRS)
MODULE
(HRS)
Availability factor computation: 1,
Divide boiler capacity by the number of modules
and obtain MW/module = x
Multiply boiler capacity by number of hours
during period = a
Add all down times due to module trouble for all modules
during period = b
Add all down times due to boiler trouble or reduction
in electricity demand for all modules during period = c
Availability factor = [a ~^_(b + c)]10° = %
5/17/74
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APPENDIX B
PLANT PHOTOGRAPHS
B-l
-------
Photo No. 1 General view of the Reid Gardner Station
of the Nevada Power Company.
Photo No. 2 Stack plume-scrubber in operation,
B-2
-------
Photo No. 3 Scrubber module and gas outlet duct,
Photo No.. 4 Sludge pond and effluent stream,
B-3
-------
Photo No. 5 Duct after cyclone to I.D. fan. Note hot-
air duct into scrubber exhaust stream.
B-4
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TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1 REPORT NO
EPA-6bO/2-75-057-j
3 RECIPIENT'S ACCESSION NO
4 TITLE AND SUBTITLE
Survey of Flue Gas Desulfurization Systems
Reid Gardner Station, Nevada Power Co.
5 REPORT DATE
October 1975
6 PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
8 PERFORMING ORGANIZATION REPORT NO
Richard W. Gerstle and Gerald A. Isaacs
9 PERFORMING ORGANIZATION 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 6j
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 (
Task Final: 10/74-9/75
COVERED
SPONSORING AGENCV CODE
15 SUPPLEMENTARY NOTES
16 ABSTRACT
The report gives results of a survey of flue gas desulfurization (FGD) sys-
tems to control SO2 and particulate emissions from two existing 125 MW generating
units at Nevada Power Company's Reid Gardner Station. Two additional 125 MW
units, originally planned for installation in 1976 and 1977, are to incorporate
similar FGD equipment. (Installation of the second new unit has been postponed
indefinitely.) The FGD systems utilize a sodium carbonate scrubbing process. The
systems, placed in operation in April 1974, did not meet SO2 and particulate
performance guarantees during their first year of operation. Each system utilizes
twin parallel Venturis followed by an absorber tower. As of August 1, 1975, System
1 had operated for 3814 hours and System 2, for 2947 hours. Potential availabilities
for the systems seem to be near 100 percent, but the plant has not had access to an
adequate supply of trona, a sodium carbonate ore that constitutes the scrubbing
medium. Alternate sodium carbonate sources were secured recently.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Flue Gases
Desulfurization
Sulfur Dioxide
Scrubbers
Coal
Combustion
Absorbers (Equipment)
Sodium Carbonates Columns (Process
Trona Engineering)
Cost Effectiveness
b IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Particulate
Venturi Scrubbers
c COSATl Held/Group
13B
21B 21D
07A.07D
07B
08G
14A
3 DISTRIBUTION STATEMENT
Unlimited
19 SECURITY CLASS (This Report)
Unclassified
21. NO OF PAGES
43
20 SECURITY CLASS (Thispage)
Unclassified
22 PRICE
EPA Form 2220-1 (9-73)
B-5
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