Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... ·...
Transcript of Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... ·...
![Page 1: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/1.jpg)
Fuel Cell Program
Diesel Reforming for Fuel Cell Auxiliary Power Units
SECA Core Technology Program ReviewAlbany NY, Sept 30 – Oct 1.
Rod Borup, W. Jerry Parkinson, Michael Inbody, Jose Tafoya, Will J. Vigil, and Dennis R. Guidry
Los Alamos National Laboratory
DOE Program ManagersSECA – Daniel Driscoll/Wayne Surdoval
POC: Rod Borup:[email protected] - (505) 667 - 2823
![Page 2: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/2.jpg)
Fuel Cell Program
Potential Applications of Diesel Reformers in Transportation Systems
Diesel Exhaust
POx/SRLean NOxCatalyst
Fuel TankNOx Reductant
SOFCEngineEGR
SOFC Fuel
ReducedNOx ExhaustDiesel Engine
The reforming of diesel fuel potentially has simultaneous on-board vehicle applications:• SECA application: reforming of diesel fuel for SOFC / APU• reductant to catalyze NOx reduction• Hydrogen addition for high engine EGR • fast light-off of catalytic convertor
![Page 3: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/3.jpg)
Fuel Cell Program
Diesel Reforming Tasks and Activities • Objectives: Develop technology suitable for on-board reforming of diesel fuel for transportation SOFC auxiliary power units
• Develop fundamentals (kinetics ….), models, examine components• Approach: Examine Catalytic partial oxidation and steam reforming• Modeling
• Carbon formation equilibrium modeling• Reformer operation with anode recycle
• Experimental• Development of direct diesel fuel injection• Adiabatic reformer operation
• Catalyst evaluation, activity measurements• Hydrocarbon breakthrough speciation
• Anode recycle simulation• Iso-thermal reforming and carbon formation measurements
• Carbon formation rate development• Catalyst regeneration due to carbon formation
![Page 4: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/4.jpg)
Fuel Cell Program
Diesel Reforming MeasurementsAdiabatic Reactor with nozzle
ModelingEquilibrium
KineticCompositionIso-thermal Microcatalyst
Iso-thermal system• Measure kinetics• Steam reforming / POx• Light-off• Carbon formation
NozzleAir / anode recycle Catalyst(Pt/Rh)
Furnace
Window for Catalyst Reaction Zone Observation
Windows forlaser diagnostics
![Page 5: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/5.jpg)
Fuel Cell Program
Relative Carbon Formation from Fuel Vaporization
-0.02
0
0.02
0.04
0.06
0.08
0.1
Diesel(commercial)
Diesel (low - S)
Kerosene(commercial)
Kerosene(low-S)
Hexadecane Dodecane
Rel
ativ
e C
arbo
n Fo
rmat
ion
Dur
ing
Fuel
Ref
luxi
ng
• Saturated pure diesel components do not show pyrolysis• S removal, decreases carbon formation (removes PAHCs)• Diesel fuel injection require technology to avoid carbon formation
during vaporization
![Page 6: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/6.jpg)
Fuel Cell Program
Direct Fuel Nozzle Operation
Simulated Anode ExhaustRecycle (H2, CO, CO2, N2, H2O, HCs)
POx/SR
Noble metalReticulated foam
Supported Catalyst
Fuel Tank
Air
Fuel PressureRegulator
P
Nozzle
• Directly inject fuel to reforming catalyst• Commercial nozzle, control fuel pressure for fuel flow (~ 80 psi)• Air / anode recycle (H2 / N2) distribute in annulus around fuel line / nozzle
• Experimental results• Operated successfully at steady state
• Minimum fuel flow dictated by fuel distribution from nozzle• Requires control of fuel/air preheat, limiting preheat (~ < 180 oC)
• Prevents fuel vaporization/particulate formation
Flowmeter
![Page 7: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/7.jpg)
Fuel Cell Program
SOFC Anode Recycle to Reformer! Water Addition
POx/SR
Fuel Tank
SOFC
Anode RecycleStream
Exhaust
AirReformate
• Methods for water introduction and availability:• Separate water tank (tank, freezing)• Anode water recovery by condensation (heat ex., cond., tank, pump freezing)• Anode recycle to reformer (blower)
Currently simulating anode recycle with N2/H2 mixture
![Page 8: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/8.jpg)
Fuel Cell Program
SOFC Anode Recycle Modeling
Green – Fractional increase in flow due to increasing gas volume due torecycle ratio, leads to larger reformer
800
820
840
860
880
900
920
940
960
0 10 20 30 40 50 60
Recycle Rate / %
Out
let T
empe
ratu
re /
o C
0
0.2
0.4
0.6
0.8
1
1.2
S/C
and
Ref
orm
er O
utle
t Flo
wra
te
Frac
tiona
l Inc
reas
e
Outlet Temp at O/C = 1
S/C
Reformer Outlet FlowrateFractional Increase
![Page 9: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/9.jpg)
Fuel Cell Program
Hydrogen / CO production
Pt / Rh supported catalystResidence time ~ 20 msecAnode recycle simulated with H2, N2, H2O
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.8 0.9 1 1.1 1.2 1.3 1.4
Oxygen / Carbon Ratio
Con
cent
ratio
n / %
H2 (40% Recycle)CO (40% Recycle)H2 + CO (40% Recycle)H2 (30% Recycle)CO (30% Recycle)H2 + CO (30% Recycle)
CO
H2
H2 + CO
30 % Recycle
30 % Recycle
30 % Recycle
40 % Recycle
40 % Recycle
40 % Recycle
![Page 10: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/10.jpg)
Fuel Cell Program
760
780
800
820
840
860
880
900
920
940
0.8 0.9 1 1.1 1.2 1.3 1.4
Oxygen / carbon ratio
Ref
orm
er O
utle
t Tem
pera
ture
/ o C
40 % Recycle30 % Recycle
Reformer temperature during diesel reforming
• Higher recycle reduces operating temperature• Operation with recycle < 30 % difficult due to high operating
temperatures and catalyst sintering
Model Pts
![Page 11: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/11.jpg)
Fuel Cell Program
Reformer Outlet Hydrocarbon Speciation
• Complete hydrocarbon conversion:• Higher O/C reduces HCs• Higher residence and catalyst loading reduces HCs
• Gasoline/PEM reforming durability work shows HCbreakthrough at ~ 500 – 750 hours
0
0.2
0.4
0.6
0.8
1
1.2
0.8 0.9 1 1.1 1.2 1.3
Oxygen / Carbon Ratio
Hyd
roca
rbon
Con
cent
ratio
n / %
.
C1C2C3C4
![Page 12: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/12.jpg)
Fuel Cell Program
Light-off of Reformer with Diesel
• Light-off requires preheating of catalyst • Degree of preheat depends upon fuel• Higher HCs and aromatics require higher
Preheat temperatures for light-off
Repeated light-offs show an increase in temperature required to achieve light-off
100
120
140
160
180
200
220
240
260
280
iso-
octa
ne
Isoo
ctan
e X
ylen
e
Isoo
ctan
e an
thra
cene
Isoo
ctan
e n
apth
alen
e
RFG
Kero
sene
Low
S D
iese
l
Die
sel
Ligh
t-off
Tem
pera
ture
/ o C
150
175
200
225
250
275
300
1 2 3 4 5 6 7 8 9 10
Run #
Tem
pera
ture
/ o C
Low Sulfur Diesel Fuel - CatalystDiesel Fuel (Set #2) - Catalyst T
![Page 13: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/13.jpg)
Fuel Cell Program
Carbon Formation Equilibrium Modeling• Various forms of carbon exist
• (different forms of carbon exist in the literature, and different forms have been observed during reforming)• Commercial codes handle vapor, liquids
• Difficult to deal with solids as 3rd phase • Difficult to input of thermodynamics components
• Different carbon forms have different thermodynamic characteristics
• Developed chemical equilibria code to analyze conditions for carbon formation• Includes 3 types of amorphous carbon
• Dent Carbon (C1)• Boudart Carbon (C2)• Water gas carbon (C3) – (limited thermodynamic data)
• Operation of model in iso-thermal modes (adding adiabatic)• C++ Code operates on Windows PC
![Page 14: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/14.jpg)
Fuel Cell Program
Model Operation & Availability• Specify:
• Isothermal• Adiabatic (needs improvement for amorphous Carbon)
• Gas phase components & concentrations• Equilibrium temperature• Pressure• Types of solid phase
• Output yields (code works where carbon formation is observed)• gas phase concentration• solid phase quantities• (Delta H reaction, outlet temperature – for adiabatic case)
•Model is (will be) available • no-cost (or nominal), non-exclusive to SECA industry teams
![Page 15: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/15.jpg)
Fuel Cell Program
Carbon Disappearance Temperature with Recycle Ratio
500
600
700
800
900
1000
1100
1200
1300
0 10 20 30 40 50 60Recycle Rate / %
Car
bon
Dis
appe
aran
ce T
empe
ratu
re /
o C
Disappearance of all types of amorphous carbon
![Page 16: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/16.jpg)
Fuel Cell Program
Carbon Formation Dependence on Recycle Ratio
• Dent Carbon (C1)• Boudart Carbon (C2)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
600 700 800 900 1000 1100 1200 1300
Temperature / oC
Rel
ativ
e C
arbo
n Fo
rmat
ion
/ Mas
s
C12 - 0% RecycleC12 - 10% RecycleC12 - 20% RecycleC12 - 30% RecycleC12 - 40% RecycleC12 - 50% Recycle
![Page 17: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/17.jpg)
Fuel Cell Program
Carbon Formation:Competing effects kinetics vs. equilibrium
0
0.05
0.1
0.15
0.2
0.25
500 550 600 650 700 750 800 850
Reforming Temperature / oC
Rel
ativ
e C
arbo
n fo
rmat
ion
/ g
Low Sulfur DieselCommercial Diesel
Conditions:Iso-thermal operationTotal O/C = 1.0Pt/Rh support catalystResidence Time = ~ 30 msec
Low temperature – high equilibrium / low kineticsHigh temperature – low equilibrium / high kinetics
![Page 18: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/18.jpg)
Fuel Cell Program
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.00088 0.00092 0.00096 0.001 0.00104
1/Temperature (K)
Car
bon
Form
atio
n
Carbon Formation MeasurementsIso-thermal operationCarbon formation trends with equilibrium at high temperatures
Trends with T (kinetic effect) at lower temperaturesCarbon Formation linear vs. 1/T
Adiabatic operationCarbon formation trends with equilibrium
Carbon decreases with increasing temperatureCarbon Formation linear vs. T
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
950 1000 1050 1100 1150Temperature / K
Car
bon
Form
atio
n
0
0.1
0.2
0.3
0.4
0.5
0.6
0.001 0.00104 0.00108 0.00112 0.00116 0.00121/Temperature (K)
Car
bon
Form
atio
n
Commercial DieselLow Sulfur Diesel
![Page 19: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/19.jpg)
Fuel Cell Program
Carbon AnalysisThermal Gravimetric analysis of catalyst post-carbon forming measurements
Carbon is not typically ‘bound’ to catalyst surface (for noble metal catalysts)
Carbon removal is about 0.4 % catalyst weight
90
92
94
96
98
100
102
0 200 400 600 800 1000 1200
Temperature / oC
Cat
alys
t wei
ght /
%
![Page 20: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/20.jpg)
Fuel Cell Program
Summary/Findings• Direct fuel injection via fuel nozzle
• Control of fuel temperature critical• Prevent fuel vaporization, fuel pyrolysis / clogging of nozzle• Potentially limited turn-down with nozzle
• Reformer operation with SOFC anode recycle• High adiabatic temperatures at low recycle rates
• Leads to catalyst sintering• Limits light-off of reformer
• High recycle increases reformer size, parasitic losses• Operation at 30 – 40 % recycle rate reasonably successful
• Limited success at lower (<20 % recycle rates due to high adiabatic T)• Carbon Formation
• Equilibrium carbon formation modeling• Equilibrium code available for iso-thermal carbon formation cases
• Experimental carbon formation measurements show kinetic effects and equilibrium effects
![Page 21: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/21.jpg)
Fuel Cell Program
Future Activities - Modeling
• Modeling • Make model available for SECA industrial teams (Beta version)
• (no or nominal cost , non-exclusive license)• Model improvements
• Incorporate other carbon species enthalpies (CH0.2)• Incorporate sulfur into equilibrium code• Improve code robustness & make ‘user friendly’
• Examine system effects of anode recycle (efficiency and parasitics)
![Page 22: Diesel Reforming for Fuel Cell Auxiliary Power Units Library/Research/Coal/energy systems... · Diesel Reforming for Fuel Cell Auxiliary Power Units ... Examine Catalytic partial](https://reader034.fdocuments.us/reader034/viewer/2022050813/5aa6971c7f8b9a517d8eb0b7/html5/thumbnails/22.jpg)
Fuel Cell Program
Future Activities - Experimental• Experimental
• Examine reformate effect on SOFC• Effect of hydrocarbon ‘breakthrough’ on SOFC
• incorporate SOFC ‘button’ cell operating on reformate• Sulfur effect on reforming kinetics• Carbon formation as function of catalyst, recycle ratio
• Reformer design considerations• Durability – catalyst sintering• Turndown – fuel / air feed preparation• Stand-alone start-up & consideration to avoid C formation• Recycle ratios – evaluate various anode recycle ratios
• ‘real’ recycle – incorporate major/minor constituents