Development of an Ultra-Low NOx Integrated System for Pulverized Coal
Fired Power Plants
Galen H. Richards
May 16, 2002May 16, 2002
DOE NOX\Technical Papers\Clearwater_3-6-02
Authors
Galen H. Richards, John L. Marion, Charles Q. Maney,
Power Plant Laboratories
ALSTOM Power, Inc.
Robert Lewis and Doug Hart
Performance Projects Businesses
ALSTOM Power, Inc.
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Participants
U.S. Department of EnergyNational Energy Technology LaboratoryPittsburgh, PA
Progress Materials, Inc.Tampa, FL
Kennecott Energy Co.Gillette, WY
U.S. Power Plant LaboratoriesALSTOM Power, Inc.Windsor, CT
Performance ProjectsUtility Boilers BUALSTOM Power, Inc.Windsor, CT
Environmental Systems Utility Boilers BUALSTOM Power, Inc.Knoxville, TN
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Objectives
Develop low cost, retrofit NOx control technologies to address current and anticipated, near term emissions control legislation for existing coal fired utility boilers.
Specific goals include:
– Achieve < 0.15 lb/MMBtu NOx for Eastern bituminous coals (current <0.25 lb/MMBtu)
– Achieve < 0.10 lb/MMBtu NOx for Western sub-bituminous coals (current < 0.15 lb/MMBtu)
– Total cost at least 25% less than SCR-only technology
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Strategy
Build upon commercially proven TFS 2000™ technology
Integrated systems solution to further reduce boiler emissions by:
– Enhancing current system components
– Optimizing fuel and air distributions
– Adding post combustion measures (as needed)
– Incorporating advanced sensor and control technology to assist in achieving and maintaining desired boiler performance
DOE NOX\Technical Papers\Clearwater_3-6-02
TFS 2000™ Firing System
• Features Include: - Flame Front Control Coal
Nozzle Tips- Concentric Firing System
(CFS™) Nozzles- Close-Coupled Overfire Air- Multi-level Separated
Overfire Air- Dynamic™ Classifiers
DOE NOX\Technical Papers\Clearwater_3-6-02
Enhancements Under Study
Optimized Transport Air to Fuel Ratio Coal & Air Flow BalancingLNCFSTM P2 Coal Nozzle TipsVariable Velocity Overfire Air Coal Fineness ImprovementAdvanced (Neural Net Based) Control SystemCarbon Burn Out™ Bubbling Bed Char Oxidizer
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Tasks
Fuels CharacterizationCFD ModelingLarge Pilot-Scale Combustion TestingEngineering & Economic Analysis
DOE NOX\Technical Papers\Clearwater_3-6-02
Fuels CharacterizationFuels Characterization
ASTM ASTM
Drop Tube Furnace SystemDrop Tube Furnace System(DTFS)(DTFS)
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Fuels Characterization
0
20
40
60
80
100
0.5 1.0 1.5 2.0 2.5 3.0Stoichiometry
Car
bon
in F
ly A
sh, W
eigh
t %
subbithvbmvb
subbit hvb mvbProximate
After Pulverization
VM 35.6 37.7 22.5FC 39.6 51.4 63.1FC/VM 1.1 1.4 2.8
UltimateMoisture 18.9 4.3 0.9Hydrogen 3.7 4.9 4.0Carbon 56.4 71.6 74.7Sulfur 0.4 2.5 1.4Nitrogen 0.9 1.5 1.3Oxygen 13.8 7.9 4.2Ash 5.9 7.2 13.6Total 100.0 100.0 100.0
HHV, BTU/lb 9890 13088 13109
0
10
20
30
40
50
60
70
80
subbit hvb mvb
Vol
atile
Mat
ter,
% D
ry-A
sh-F
ree
ASTM DTFS-1
DTFS
DOE NOX\Technical Papers\Clearwater_3-6-02
DTFS - Nitrogen Evolution
50
60
70
80
90
100
110
0.50 1.00 1.50 2.00 2.50 3.00Stoichiometry
Fuel
Nitr
ogen
Evo
lutio
n, W
eigh
t %
subbithvbmvb
Subbit. & hvb coals release nitrogen more readily than mvb coal
mvb coal retains larger fraction of nitrogen in the charChar nitrogen more likely to form NOx
50
60
70
80
90
100
110
50 60 70 80 90 100 110Carbon Conversion Efficiency, Weight %
Fuel
Nitr
ogen
Evo
lutio
n, W
eigh
t %
subbithvbmvb
DOE NOX\Technical Papers\Clearwater_3-6-02
Large PilotLarge Pilot--Scale Scale Combustion TestingCombustion Testing
DOE NOX\Technical Papers\Clearwater_3-6-02
Boiler Simulation Facility (BSF)
• Large-pilot scale, utility boiler design combustion test facility
• Models hopper through economizer region
• 60 MMBtu/hr firing rate
• Coal, oil, or natural gas capable
• Tangential or wall fired operating modes
• Used for the development of ALSTOM Power’s TFS 2000™ Firing System
DOE NOX\Technical Papers\Clearwater_3-6-02
BSF Test Results - NOx
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
subbit hvb mvb
NO
x [lb
/MM
Btu
]
Baseline TFS 2000 Ultra Low NOx System Microfine
0.15 lb/MMBtu
65% -200 mesh 85% -200 mesh 85% -200 mesh96% -325 mesh
DOE NOX\Technical Papers\Clearwater_3-6-02
BSF Test Results -Carbon in Fly Ash
0
2
4
6
8
10
subbit hvb mvb
% C
arbo
n in
Fly
Ash
Baseline TFS 2000 Ultra Low NOx System Microfine
65% -200 mesh 85% -200 mesh 85% -200 mesh96% -325 mesh
DOE NOX\Technical Papers\Clearwater_3-6-02
Engineering & Economic Engineering & Economic AnalysisAnalysis
DOE NOX\Technical Papers\Clearwater_3-6-02
Scope of Analysis
3 T-Fired Utility Boilers in U.S.– Unit A: 400 MW, East Coast, Eastern Bit. compliance coal– Unit B: 500 MW, Midwest U.S., Midwestern Bit. coal
– Unit C: 330 MW, Western U.S., PRB coal
NOx Reduction Options Evaluated– Buying NOx Credits– TFS 2000™ Firing System– Ultra Low NOx Firing System– SCR– Fuel Switching to PRB– Use of Carbon Burnout Device™ (bubbling bed)
DOE NOX\Technical Papers\Clearwater_3-6-02
Scope of Analysis (cont.)
Boiler performance modeling to determine:– Net plant heat rate– Net electric output– Scope of surface modifications required
Budgetary pricing of hardware modificationsALSTOM POWER economic model
DOE NOX\Technical Papers\Clearwater_3-6-02
Economic Model Assumptions
Parameter Value UnitsDepreciable Life 15 YearsEquity 50 %Interest Rate 9 %Capacity Factor 70 %Ash Disposal Cost 10 $/tonAsh Value 5 $/tonNOx Limit 0.15 lb/106 BtuSO2 Credits 150 $/tonNOx Credits 1500 $/tonSCR Efficiency 80 %SCR Installed Cost 100 $/kw
DOE NOX\Technical Papers\Clearwater_3-6-02
Delivered Fuel Costs
2001 plant fuel costsPRB fuel switch - coal supplier estimate
$/MMBtuUnit A East. Bit. 1.83 PRB 2.10Unit B Midwest. Bit. 0.88 PRB 1.10Unit A PRB 0.50
DOE NOX\Technical Papers\Clearwater_3-6-02
Predicted NOx Emissions for Economic Study
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Baseline BuyCredits
TFS 2000 ULN ULN +CBO
TFS2000+ PRB
ULN +PRB
SCR TFS2000+ SCR
NO
x Em
issi
ons,
lb/M
MB
tu
Unit A - 400MW, East. Bit
Unit B - 500MW, Midwest. Bit
Unit C - 330MW, PRB**
* Post NSPS Units
0.15 lb/MMBtu
DOE NOX\Technical Papers\Clearwater_3-6-02
Project Capital Cost
0
10
20
30
40
50
60
70
BuyCredits
TFS2000
ULN ULN +CBO
TFS2000+ PRB
ULN +PRB
SCR TFS2000+ SCR
Cap
ital C
ost,
$MU
SD
Unit A - 400MW, East. Bit
Unit B - 500MW, Midwest. Bit
Unit C - 330MW, PRB
DOE NOX\Technical Papers\Clearwater_3-6-02
Impact on Cost of Electricity
-1.5
-0.5
0.5
1.5
2.5
3.5
4.5
BuyCredits
TFS 2000 ULN ULN +CBO
TFS2000+ PRB
ULN +PRB
SCR TFS2000+ SCR
Leve
lized
Incr
ease
in C
ost o
f Ele
ctric
ity, (
mill
s/kW
h)
-2
-1
1
2
3
4
5Unit A - 400MW, East. BitUnit B - 500MW, Midwest. BitUnit C - 330MW, PRB
Note: All cases meet NOx compliance by performance or purchased credits.
↑ ↑ ↑↑ ↑
↑
↑ ↑ ↑↑ ↑ ↑
↑ = NOx compliant by performance.
DOE NOX\Technical Papers\Clearwater_3-6-02
Impact of PRB Fuel Cost - Unit A
0.0
1.0
2.0
3.0
4.0
5.0
Buy Credits TFS 2000 ULN TFS2000 +PRB
ULN + PRB SCR
Leve
lized
Incr
ease
in C
OE,
(mill
s/kW
h) PRB Cost = 2.1 $/MMBtu PRB Cost = 1.83 $/MMBtu
DOE NOX\Technical Papers\Clearwater_3-6-02
Impact of NOx Credit Price - Unit A
0.0
1.0
2.0
3.0
4.0
5.0
Buy Credits TFS 2000 ULN TFS2000 +PRB
ULN + PRB SCR
Leve
lized
Incr
ease
in C
ost o
f Ele
ctric
ity, (
mill
s/kW
h)
$1000/ton $1500/ton $3000/ton
DOE NOX\Technical Papers\Clearwater_3-6-02
Observations from Economic Analysis
“Best” NOx reduction strategy is unit specific.Unit A - Eastern U.S.– TFS 2000™(0.22 lb/MMBtu) best for hvb coal.– Economics are sensitive to PRB fuel and NOx credit price.
Unit B - Midwestern U.S.– Ultra low NOx system (0.18 lb/MMBtu NOx) best for hvb coal.– Best NOx solution - Comb. Mods with fuel switch to PRB coal.
Unit C - Western U.S.– Ultra low NOx system (0.13 lb/MMBtu NOx) best for PRB coal.
DOE NOX\Technical Papers\Clearwater_3-6-02
ALSTOM T-Fired Low NOx Experience
Rank Fuel TypeUnit Size
MWe Status
Low NOxSystemType
EPA 3rd Qtr2001 NOxLb/MMBtu
1 PRB 600 Complete SOFA 0.102 PRB 600 Complete SOFA 0.113 PRB 600 Complete SOFA 0.114 PRB 600 Complete SOFA 0.115 PRB 600 Complete SOFA 0.126 PRB 580 Complete SOFA 0.127 PRB 325 Complete SOFA 0.138 PRB 600 Complete SOFA 0.139 PRB 600 Complete SOFA 0.1410 PRB 600 Complete SOFA 0.1411 PRB 165 Complete Ext. WB 0.14 (CS)12 PRB 165 Complete Ext. WB 0.14 (CS)13 PRB 165 Complete Ext. WB 0.14 (CS)14 PRB 165 Complete Ext. WB 0.14 (CS)15 PRB 165 Complete Ext. WB 0.14 (CS)16 PRB 165 Complete Ext. WB 0.14 (CS)17 PRB 600 Complete SOFA 0.1518 PRB 600 Complete SOFA 0.1519 PRB 520 Complete In Windbox 0.1520 PRB 200 Complete SOFA 0.16
DOE NOX\Technical Papers\Clearwater_3-6-02
Conclusions
TFS 2000™ achieves good balance of NOx reduction and unburned carbon. Ultra Low NOx Integrated System achieves up to 0.03 lb/MMBtu additional NOx reduction over TFS 2000™. 0.15 lb/MMBtu can be achieved with T-firing and PRB coals.“Best” NOx reduction strategy is unit and fuel specific.
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