Post on 25-Aug-2020
transcript
Institute of Chemical Engineering: Future Energy Technology Prof. Hermann Hofbauer www.vt.tuwien.ac.at
Chemical looping combustion using biomass as fuel Stefan Penthor, Tobias Pröll, Hermann Hofbauer
2nd Oxyfuel Combustion Conference, 12-16 September 2011, Yeppoon, Australia
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Outline
• Introduction
• Challenges and why biomass
• Solutions
• Modeling
• Results
• Conclusion/Outlook
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
What is CLC?
Cooling/
Condensation
Air
Air Reactor
(AR)
Fuel Reactor
(FR)
MeOx-1
MeOx N2, (O2) CO2, (H2O)
H2O
CO2
Steam
Solid Fuel
Unique potential for CCS - air and fuel are never mixed!
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Challenges • Decomposition of fuel
• Conversion of combustible gas species
• Avoiding loss of carbon to air reactor
• Separating ash from oxygen carrier
• Finding suitable oxygen carrier
• Finding suitable reactor concept
Objectives
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Why biomass?
Petroleum coke
South African coal
Woody biomass
Volatiles [%] 10 21.6 80
Moisture [%] 8 8.3 25
Ash [%] 0.5 15.9 1.5
• Reactive char (compared to coal)
• Carbon neutral, low sulfur
• Below zero emission
• Stopover to coal
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Solutions
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
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heig
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pressure gradient [mbar/m]
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pressure drop [mbar]
Cold flow model tests
Schmid J.C., et al., Int. Conference on Polygeneration Strategies, 2011
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Modeling
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
• Mass & energy balance
• Basic char gasification kinetics
• Chemical equilibrium for CO and H2 oxidation
• Solids segregation
Modeling approach
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Solids segregation
φi=mi,out,top
mi,out,bottom i=OC, Ash, Char
OC
AshSolids
Char
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
First results
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
• Pth = 1 MW
• Ilmenite as oxygen carrier
• • = 1.2
• Steam/Carbon = 0.5
• • OC = 0.05
• • Ash = 0.2
• • Char = 0.1
• •Char = 9 - 20 s
• TLLS = 950 C
Base case
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
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Reac
tion
Zone
[-]
Temperature [°C]
• TAR = 1015 C
• • sep, CO2 = 92.0 %
• Ash accumulation:
• xAsh,ILS = 37.4 %
• xAsh,LLS = 13.1 %
Fuel feed
Base case
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
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• _Ash [-]
LLS @ 5kg/h OC make up
ILS @ 5kg/h OC make up
LLS @ 10kg/h OC make up
ILS @ 10kg/h OC make up
• Ash variation
Base case
CLC using biomass as fuel Stefan Penthor
Institute of Chemical Engineering Future Energy Technology
Conclusions/Outlook
• Multistage CFB can be key to solid fuel CLC
• Gas-solid contact and residence time improved
• Selective ash removal possible
• Process model created, validation necessary
• Cold flow model testing
• Build 100 kW pilot plant
Institute of Chemical Engineering: Future Energy Technology Prof. Hermann Hofbauer www.vt.tuwien.ac.at
Thank you for your attention!
Contact: Stefan Penthor
stefan.penthor@tuwien.ac.at www.chemical-looping.at