Research Topic 3
Biomass Conversion
• Pyrolysis is the thermal decomposition of
biomass in the absence of oxygen or in amounts
of oxygen significantly less than required for
complete combustion
• Gasification is the chemical reaction of biomass
to syngas with careful control of the amount of
oxygen
Applications and New Concepts
Bioethanol Reforming
C2H5OH + 3H2O
6 H2 + 2 CO2
Ho298 = 173.5 kJ/mol
• Exploits advances in bioethanol production
• Allows CO2-neutral production of hydrogen
Pyrolysis Products
Gases (10-20%)
(Mainly CO, CO2, CH4, H2, H2O)
Solid Biomass
Tar (Bio-oil) (60-75%)
(High molecular weight liquids,
volatile at reaction temperature)
Char (10-20%)
(Solid carbonaceous residue)
Reaction Scheme
Gas + Bio-oil
425-600 oC
Char
Gas
Bio-oil
Char
Biomass
Physical
Processes
Heat transfer by conduction,
convection and radiation
Pressure gradients
Chemical
inside the degrading solid Processes
Surface regression,
crack formation,
swelling, shrinkage
Primary degradation to form
char and gases
Secondary reactions,
polymerization, cracking
Conventional Pyrolysis
4 Biomass feeder
3 Ceramic candle filter
2 Cyclone
7 Volumetric gas-meter
6 Blower
1 Fluidized-bed gasifier
5 Water and tar condensation system
Catalytic Processing of Pyrolysis Oil
Hydrodeoxygenation
(Conventional CoMoS/Al2O3, NiMoS/Al2O3)
(New: Ni2P, WP, VN, Mo2C)
Hydrocracking
(USY, SiO2-Al2O3, ZSM-5, Pt/Al2O3, )
Reforming
(Ni/Al2O3, Rh/Al2O3, Ni2P, Mo2C)
Other possibilities
Wide-pore zeolites, mesoporous solids
Project Concepts
• New reactor design for combined pyrolysis/catalysis
• Recycle of gases for fluidization and reaction