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OPERATION OF THE PSDF TRANSPORT GASIFIER
Session: New DevelopmentsGasification Technologies 2002
October 30, 2002
Peter V. Smith Kellogg Brown & Root, Inc. (KBR)
Brandon M. DavisP. Vimalchand
Guohai Liu Southern Company Services
James Longanbach National Energy Technology Laboratory
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What Is The PSDF?
The PSDF is a joint-DOE/industry research facility
where advanced power systems can be tested in an
integrated environment at a scale sufficient to provide
confidence and data for commercial design.
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Power Systems Development Facility Program Objective
Develop advanced coal-based power generation
technologies that can produce electricity at
competitive cost while meeting all environmental
standards and support Vision 21.
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PSDF Participants•U.S. Department of Energy - National Energy Technology Laboratory •Southern Company•KBR•Siemens-Westinghouse•Electric Power Research Institute•Peabody Holding Company•Southern Research Institute
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America’s Advanced Coal Research Center
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Transport Reactor SystemCoalSorbent
AirSteam
Ash
Flue Gas
airSyngas Combustor
Baghouse
Stack
Pressure LetdownGas Cooler
Recycle Gas
cooling
N2 or Air
cooling
cooling
Ash
Ash Hopper
cooling
AFBC
cooling
Screw Cooler
AshLockhoppers
TransportReactor
Disengager
StartupBurner
Cyclone
Gas Cooler
Lockhoppers
Char/Ash
Siemens -Westinghouse PCD
Gas Cooler
Air
ScrewCooler
ScrewCooler
AirSteamOxygen
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Transport Reactor
Sorbent
AirSteam
Coal
MixingZone
Riser
Disengager To PrimaryGas Cooler
Loopseal
Cyclone
Standpipe
J-leg
StartupBurner
(propane)
AirOxygenSteam
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CoalSorbent
Air
ProcessGas
SpentSolids
Advantages of Pressurized Transport Reactor
•Excellent Gas-Solids Contact.
•Low Mass Transfer Resistance between Gas and Solids.
•Highly Turbulent Atmosphere
•High-coal throughput
•High Heat release
•Designed without expansion joints
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Loop Seal Modification
Original Design
ModifiedAreas
Loop SealLayout
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Lower Mixing Zone Modification
Replaced
•Existing piping unsuitable for oxygen •Test different method for distributing steam and oxygen•No internals in design
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Lower Mixing Zone ModificationOxygen Blown Design
4 O2 + H2O Nozzles
N2
Steam
O2
N2Air
O2 + H2O
4 H2O Nozzles
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Gasification Summary
309Air & Oxygen
Bituminous HiawathaSeptember 2002TC09
442AirPRBAlabama Bituminous
January – April 2002
TC07
364Air & Oxygen
PRBJune 2002TC08
1025AirPRBJuly –September 2001
TC06242AirPRBMarch 2001GCT4183AirPRBJanuary 2001GCT3217AirPRBApril 2000GCT2
233AirPRBAlabama BituminousIllinois #6
September –December 1999
GCT1HoursModeFuelsDatesTest Run
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Coal PropertiesPRB Hiawatha
Moisture, wt% 20.93 9.80Carbon, wt% 57.02 64.70Hydrogen, wt% 3.74 4.40Nitrogen, wt% 0.66 1.10Sulfur, wt% 0.26 0.37Ash, wt% 5.23 8.50Volatiles, wt% 37.39 35.90Fixed Carbon, wt% 36.46 45.80Higher Heating Value, Btu/lb 9,391 11,400Lower Heating Value, Btu/lb 8,828 10,891CaO, wt % 1.27 1.11Ca/S, mole/mole 2.83 1.67
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Typical Operating Conditions
Fuel Type Powder River Basin, Alabama Calumet Bituminous, Hiawatha.
Fuel Particle Size (mmd), µm 200 - 350 Average Fuel Feed Rate, pph 2,700 - 5,000Sorbent Type Ohio Bucyrus limestoneSorbent Particle Size (mmd), µm 10 - 30 Sorbent Feed Rate, pph 0 - 200 Reactor Temperature, °F 1670 - 1850Reactor Pressure, psig 140 - 270 Riser Gas Velocity, fps 40 – 60Riser Mass Flux, lb/s·ft2 150 - 700 Synthesis Gas Flowrate, pph 15,000 - 30,000 Air/coal ratio 2.5 – 3.5Steam/coal mass ratio 0.0 to 1.0
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Lower Heating Value
( ) ( )( ) ( ) 100/
%C1641%CH913
CO%322%H275F)LHV(Btu/SC
24
2
×+×
+×+×=
+
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Per Cent Oxygen Fed
22
222 OPureNPureSteamAir
OPureOAirO%+++
+=
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Raw LHV
0
20
40
60
80
100
120
8 9 10 11 12 13 14 15 16 17 18 19 20 21
Overall O2 in Feed Gas, %
Low
er H
eatin
g V
alue
, Btu
/SC
F
PRB Air blownPRB Oxygen BlownHiawatha Air BlownHiawatha Oxygen Blown
Overall % O2 in Feed GasEffect on Raw LHV
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Nitrogen Correction• Remove aeration & instrument nitrogen
– Commercial design will use recycle gas– Does not change Water Gas Shift
• Remove heat (coal) required to heat extra nitrogen– Removes N2, CO2, & H2O– Changes Water Gas Shift
• Adiabatic correction – Removes heat (coal) lost by reactor
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Corrected LHV
0
50
100
150
200
250
10 15 20 25 30 35 40 45Overall O2 in Feed Gas, %
Low
er H
eatin
g V
alue
, Btu
/SC
F
PRB Air BlownPRB Oxygen BlownHiawatha Air BlownHiawatha Oxygen Blown
N2 Corrected LHV Overall % O2 in Feed Gas
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Carbon Conversion
The per cent of fuel carbon that is converted to gaseous carbon- CO2, CO, CH4, C2
+.
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Carbon Conversion
50
55
60
65
70
75
80
85
90
95
100
1,660 1,680 1,700 1,720 1,740 1,760 1,780 1,800 1,820 1,840 1,860Riser Temperature, F
Car
bon
Con
vers
ion,
%
Powder River Basin
Hiawatha Bituminous
Riser TemperatureEffect on Carbon Conversion
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Reactor Inventory Change
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1,000Run Time, hours
Wei
ght %
SiO2
CaO
Al2O3
TC06 - PRB CoalStandpipe SiO2, CaO, & Al2O3
4 Week Break7/25/01 to 8/20/01
Bed Material Replaced
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H2S Capture - Theory
23 COCaOCaCO +↔
2232 COOHCaSCaCOSH ++↔+
OHCaSCaOSH 22 +↔+
OSH
OOH
22
2
PP
K = OSH
OCO
OOH
22
22
PPP
K =oCO1 2
PK =
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Equilibrium H2S
0
100
200
300
400
500
600
1,400 1,500 1,600 1,700 1,800 1,900 2,000Temperature, F
H2S
Con
cent
ratio
n, p
pm
Measured Sulfur emissions
Maximum Sulfur emissions
CaOCaCO3
TC06-32H2S-CO2-H2O-
CaCO3-CaO-CaSEquilibrium
Equilibrium H2S Concentration
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PRB Sulfur Emissions
0
100
200
300
400
500
600
700
0 100 200 300 400 500 600 700Measured Total Reduced Sulfur, ppm
Equi
libriu
m H
2S, p
pm
PRB - Sorbent AddedPRB - No Sorbent Added45 Degree Line
Total Reduced Sulfur Emissions &Equilibrium H2S - PRB Coal
Data taken at start of run
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TC08 Sulfur Emissions
0
100
200
300
400
500
600
700
0 50 100 150 200 250 300 350 400Run Time, hrs
TRS
or E
quili
briu
m H
2S, p
pm
0
2
4
6
8
10
12
14
Stan
dpip
e C
aO, w
t%
Measured TRSEquilibrium H2SStandpipe CaO
Unit tripped,sand added
Unit tripped,sand added
TC08 - PRB Coal, No Sorbent Added
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Hiawatha Sulfur Emissions
0
100
200
300
400500
600
700
800900
1,000
0 50 100 150 200 250 300 350Run Time - Hours
TRS
or H
2S, p
pm
TRS EmissionMax Coal TRSEQM H2S
TC09 Hiawatha Bituminous
Sulfur EmissionsOutage
O2 - Blown
Outage
No Sorbent Added
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Future Plans• Connect Transport Reactor to Combustion
Turbine• Test Other Coals, Petroleum Coke• Test Improved Coal Feeder• Commission Recycle Gas System• Demonstrate Hot Gas Emissions Control
Techniques
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Conclusions•Met commercial goals for gas heating values and carbon conversions for subbituminous PRB coal. •Hiawatha bituminous coal was successfully gasified in air and oxygen blown mode.•Hiawatha gas heating values consistent with PRB, but Hiawatha carbon conversions lower than PRB•Sulfur emissions were as predicted from thermodynamic equilibrium at low sulfur emissions when injecting limestone. •The Powder River Basin coal ash alkalinity was nearly sufficient to remove the equilibrium amount of synthesis gas sulfur. •The oxygen delivery and new lower mixing zone operated well, permitting stable Transport reactor operation on both enriched air and full oxygen-blown service.
