FIELD TEST OF A 1.5 MW INDUSTRIAL GAS TURBINE WITH A LOW EMISSIONS
CATALYTIC COMBUSTION SYSTEM
Ralph A. Dalla BettaSarento G. NickolasChrisK. WeakleyKare LundbergCatalytica Combustion Systems, Inc.
Combustion Systems
Tim J. CaronJohn ChamberlainAgilis Group, Inc.
Kevin GreebWoodward Governor Company
Catalytica Combustion Systems, Inc.
Program Objectives and Strategy
Combustor to be a demonstrator of catalytic technology– Materials selected to minimize development time– No size limitations
Basic engine/combustor approach– No modifications to gas turbine– Combustor change out at combustor flange– Natural gas fuel only
Performance targets– Emissions over 90 to 100% load range and wide ambient
NOx < 3 ppmCO < 5 ppmUHC < 5 ppm
– Minimal impact on turbine performanceCombustor outlet temperature of 1300°C (2400°F) to demonstrate catalytic combustion technology for wide range of engines
Catalytica Combustion Systems, Inc.
Schematic of combustor configuration
Preburner provides required catalyst inlet temperatureCatalyst fuel injector produces a uniform fuel/air mixture for the catalystHigh post catalyst temperature oxidizes CO to < 10 ppmBypass and cooling air provides required turbine inlet temperature
CompressorPr
ebur
nerCat a lyst Burn out
zoneT urb ine
Byp ass/ cooling airFu
el I
njec
tor
330°C 630°F
450°C 840°F
1300°C 2370°F
1010°C 1850°F
Catalytica Combustion Systems, Inc.
One Aspect of Catalyst System
Metal or ceramic substrate
Washcoat layer
Gas flow
High surface area oxide support
Catalytic component dispersed on the oxide support
Monolith
Catalytic
Non-Catalytic
Temperature controlled by “Integral Heat Exchange” structure that limits catalyst temperature below adiabatic combustion temperature
Catalytica Combustion Systems, Inc.
Integral Heat Exchange
Integral heat exchange (IHE) limits catalyst temperature
Bulk flow
Boundary layerCatalyst
Foil substrate
Boundary layer
Bulk flow
ProductsReactants Rxn heat
Rxn heat
Ts = Tin + ² Tad
2
• Solid cross-section essentially isothermal • Equal heat transferred to catalyzed and non-catalyzed channels • Maximum conversion = 50% • Maximum wall temperature = Tin + ² Tad • Example: Inlet gas T = 700°C (1290°F) Tad = 1300°C (2370°F) non-IHE wall T = 1300°C(2370°F) IHE wall T = 1000°C (1830°F)
12
Catalytica Combustion Systems, Inc.
XONON 1 Catalyst performance and operating line
1 3 0 01 2 0 01 1 0 01 0 0 09 0 08 0 07 0 07 0 03 0 0
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
Burnout z one t emperat ure ( °C)
Cat
alys
t in
let
tem
pera
ture
(°C
)
0 22 36 55 70 84 10 0Load ( %)
Syst em limit
CO < 1 0 pp m
UHC < 1 0 0 ppm
UHC < 1 0 0 0 ppm
Comp resso r discharg e
Op erat ing line
• Measured on Sub-scale rig at operating conditions
Catalytica Combustion Systems, Inc.
XONON design flexibility
Surface
All of fuel
All of airInlet
catalystOutlet
catalystHomogeneous
combustion
Tad
TemperatureGas
• Higher wall T (designlimits max wall T)
• High outlet gas T
• High activity• Low lightoff T• Designed for low wall T
Sufficient time to:• Complete CH4 combustion• Complete UHC and CO burnout
Catalytica Combustion Systems, Inc.
Combustor cross section
Stage 1 catalystStage 2 catalyst
Post catalyst reaction zone
Infrared camera
Primary tube exit
Secondary tube
Preburner
Preburner exit gas sample
Catalyst fuel injector/mixer
Catalyst inlet gas sample
Slots
Catalytica Combustion Systems, Inc.
Preburner Design
RequirementsTemperature rise of 700°C (1200°F) during starting and accelerationLow emissions load range requires 80 to 150°C(150 to 270°F) temperature rise NOx contribution at engine exhaust < 2 ppm over low emissions load range
DesignLean premix swirl stabilized primary
– Operates from LBO+20% to NOx limitLean premixed parallel secondary ignited by primaryMore then 50% of combustor air flow is added downstream of the primary and secondary prior to catalyst inlet
Catalytica Combustion Systems, Inc.
Preburner: Perspective View
Preburner liner
Axial entry secondary mixing tube
Tangnetial entry primary mixing tube
Dilution flow
Catalytica Combustion Systems, Inc.
Catalyst Fuel-Air Mixing System
RequirementsFuel-air mixture uniformity < ± 3% of mean at catalyst inletNo recirculation or stagnation zones that would hold flame downstream of fuel injection
DesignPreburner exhaust flow is reversed to enhance temperature uniformity upstream of the fuel injectorFuel is injected upstream of counter rotating swirlers
– 36 swirl vanes and 36 fuel injection pegs– Counter rotating flows promote mixing with low
tangential velocity just upstream of the catalyst
Catalytica Combustion Systems, Inc.
Catalytic Module
~95% open area for low pressure dropAll metal structure for thermal shock resistance
Catalytica Combustion Systems, Inc.
Engine Test Cell Layout
Air intakeDynamometer water cooling tower
Air eductor
Dynamometer
Air intake
Gear box
Gas turbine
Catalytica Combustion Systems, Inc.
On Engine Preburner Testing
Static pressure tap downstream of mixed preburner exhaust used to measure gas compositionEngine operated at part load Fuel to preburner primary and secondary could be varied over a reasonable range
– Must stay within catalyst operating zone– Engine was operated in speed control mode with set
dynamometer load
Catalytica Combustion Systems, Inc.
Primary Zone PerformanceMeasured at preburner exitNo secondary fuel
0
50
100
150
200
250
300
0.6 0.7 0.8 0.9 1 1.1
Equivalence ratio
CO
and
UH
C (p
pm)
-5
0
5
10
15
20
25
30
NO
x (p
pm)
NOxCO
UHC
Catalytica Combustion Systems, Inc.
Secondary Performance
Primary Ø=0.86Measured at preburner exit
0
1000
2000
3000
4000
0 0.1 0.2 0.3 0.4 0.5
Equivalence ratio
UH
C a
nd C
O (p
pm)
0
1
2
3
4
5
NO
x (p
pm)
UHC
NOx
CO
Catalytica Combustion Systems, Inc.
Secondary Performance
Primary Ø=0.86Measured at preburner exit
0
25
50
75
100
125
150
0 0.1 0.2 0.3 0.4 0.5
Equivalence ratio
Tem
pera
ture
rise
(°C
)
0
1
2
3
4
5
NO
x (p
pm)
Temperature rise
NOx
Catalytica Combustion Systems, Inc.
Fuel-Air Mixer Performance
18 sampling tubes at the catalyst inlet face used to extract mixture for analysis by FID hydrocarbon analyzer
Measurement done under constant dynamometer load with engine in speed control mode
Measurement time was ~20 minutes
Some measurement variation may arise from total fuel variation required for engine control
– Especially large at low catalyst fuel flow
Catalytica Combustion Systems, Inc.
F/A Map at Catalyst Inlet--1065 kW
Results
Relative F/A ratioMin 0.991Max 1.008
Range ± 0.9%O
O
O
O
O
OO
OO
O
O
O
OO
O
O
O
O
-8
-6
-4
-2
0
2
4
6
8
-8 -6 -4 -2 0 2 4 6 8
Y-C
oord
inat
e
X-Coordinate
1.00
1.00
1.00
1.00
1.00
0.990.99
1.001.00
1.00
1.00
1.00
1.011.01
1.00
0.99
1.00
0.99
Catalyst OD
Catalytica Combustion Systems, Inc.
Infrared Image at Full Load (EGT limit)
994125c4
903 C 891 C
870 C
Uniformity = ~ 75 C
Catalytica Combustion Systems, Inc.
Engine Performance
Measured at engine exhaustCorrected to 15% O2
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
0 200 400 600 800 1000 1200 1400
Load (kW)
NO
x (p
pm)
0
20
40
60
80
100
UH
C a
nd C
O(p
pm)
CO
UHC
NOx
Raw NOx
Catalytica Combustion Systems, Inc.
Summary
Combustor designed and fabricated to demonstrate catalytic combustion on a 1.5 MW industrial gas turbine
System operated at base load for 1000 hours
System provides emissions levels of:NOx < 3 ppmCO < 1 ppmUHC < 1 ppm
Catalyst shows good durability to high loading of air contaminants
Combustor dynamics were very low