National Seminar Creating Infrastructure for adoption of fuel cell Technology in India April 15, 200

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National SeminarCreating Infrastructure for
adoption of fuel cell Technology in IndiaApril
15, 2004
Recent Trends in Production of Hydrogen from
Biomass
Dr. A. K. GuptaINDIAN INSTITUTE OF
PETROLEUMDEHRADUN, INDIA
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• Why Biomass to hydrogen?
• Biomass has the potential to accelerate the
  realization of hydrogen as a major fuel of the
  future.
• Biomass is renewable, consumes atmospheric CO2
  during growth and is a CO2 neutral resource in
  life cycle.
• It can have a small net CO2 impact compared to
  fossil fuels.

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Routes to H2 From Biomass

• Biomass conversion technologies can be divided
  into two categories.
• Direct production routes (simplicity of process).
• Conversion of storable intermediates (additional
  production steps, distributed production of
  intermediates, lower transportation costs of
  biomass, larger-scale H2 production facilities.)
• Both categories involve thermochemical and
  biological routes.

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Pathways From Biomass to H2
Biomass
Thermochemical
Gasification
Pyrolysis
High Pressure Aqueous
Severe
H2/CO
CH4/CO2
CH4/CO2
CH1.4O.6
Synthesis
Bio-shift
CH3OH/CO2
Reforming shift
Reforming shift
Shift
Reforming shift
H2/CO2
H2/CO2
H2/CO2
H2/CO2
H2/CO2
H2/C
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Pathways from Biomass to H2
Biomass
Biological
Anaerobic Digestion
Fermentation
Metabolic Processing
CH3CH2OH/CO2
CH4/CO2
Bio-shift
Reforming shift
Reforming shift
Photo- biology
Pyrolysis
H2/CO2
H2/CO2
H2/CO2
H2/C
H2/O2
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Metabolic Processing of Biomass

• H2 from biomass can also be produced by metabolic
  processing to split water via photosynthesis or
  to perform the shift reaction by photo biological
  organisms. The use of microorganisms to perform
  the shift reaction is of great relevance to
  hydrogen production because of the potential to
  produce CO in the product gas far below than in
  water gas shift catalysts.

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Direct Production of H2 From Biomass

• Gasification coupled with water-gas shift is the
  most widely practiced process route for biomass
  to H2.
• Thermal, steam and partial oxidation gasification
  technologies are under development around the
  world.
• Feedstocks include both dedicated crops and
  agricultural and forest product residues of
  hardwood, softwood and herbaceous species.

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Oxidative Pyrolysis

• By including O2 in the reaction separate supply
  of energy is not required
• Biomass O2 CO H2 CO2
  Energy
• If air is used to supply O2 then N2 is also
  present.
• Examples GTI high pressure O2 blown gasifier,
  CFBD (TPS Termiska), High pressure slurry bed
  entrained flow gasifier (Texaco)

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Direct Solar Gasification

• Several investigators have examined the use of
  solar process heat for gasification or organic
  solid wastes to produce H2.
• Studies have shown favourable economic
  projections for solar gasification of
  carbonaceous materials such as agricultural waste
  to produce syn gas for producing H2.

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Other Direct Processes Explored..

• Several other heat sources and chemistries have
  been explored for H2 from biomass/organic
  materials.
• Use of thermo-nuclear device to vaporize waste
  organic materials in an underground large-scale
  plasma process.
• Electrochemical oxidation of solid carbonaceous
  wastes.

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Biomass Derived Synthesis Gas (Syn Gas) Conversion

• Sponge Iron and related processes
• Steam Iron processes is one of the oldest
  processes for producing H2 from syngas.
  (developed as early as 1910).
• Fe3O4 4CO 3Fe 4CO2
• 3Fe 4H2O Fe3O4 4H2
• Recently sponge Iron process has been extended to
  FeO
• 3FeO H2O H2 Fe3O4
• Metal hydrides (e.g. LaNi5, and La Ni4.7 Al0.3)
  has also been investigated for continuous
  hydrogen recovery from biomass gasification
  mixtures lean mixtures.

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Supercritical Conversion of Biomass

• Aqueous conversion of whole biomass to H2 under
  low temperature supercritical conditions in
  another area of investigation in recent years.
• Corrosion, pumping of biomass slurry, improvement
  in heating rates, heat transfer, commercial
  reactor system development are some of the
  problems need attention.

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Pyrolysis to Hydrogen and Carbon or Methanol

• This is a high temperature two-step process
  involving
• Conversion of biomass to methane
• Thermal decomposition of methane to H2 and clean
  carbon-black
• Typical overall stoichiometry is
• CH1.44 O0.66 ? C 0.6 H2 0.66 H2O
• The process is called Hydrocarb process
• In another process Carnol Process methanol is
  produced with H2
• CH1.44 O0.66 0.30 CH4 0.64 C 0.66
  CH3OH

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Storable Intermediates

• Bio-oil reforming
• Pyrolysis of biomass produces liquid product
  called bio-oil or pyrolysis oils which is the
  basis of several processes for producing H2 via
  catalytic steam reforming of bio-oil at
  750-850C.
• Bio-oil H2O CO2 H2
• CO H2O CO2 H2
• Pyrolysis is endothermic
• Biomass Energy ? Bio-oil Char Gas
• Over all stoichiometry gives a maximum yield of
  17.2 gH/100 g bio-oil i.e. about 11.2 based on
  wood.
• Typical over all stoichiometry based on wood is
• CH1.9 O0.7 1.26 H2O CO2 2.21 H2

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• Storalable Intermediates
• Regional networks of pyrolysis plants can be
  established to provide bio-oil to a central steam
  reforming facility
• Methanol/Ethanol can also be produced from
  biomass by a variety of technologies and used for
  on-board reforming for transportation
• Methane could be produced by anaerobic digestion
  which on steam reforming produce H2
• Methane could be pyrolysed to H2 and carbon, if
  markets for carbon black are available.

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Co-production of Methanol and Hydrogen

• Both methanol and H2 are well suited for fuel
  cell vehicles (FCVs)
• Methanol and H2 can be produced from biomass via
  gasification
• Overall efficiencies of around 55 for methanol
  and around 60 for hydrogen may be obtained.
• Using liquid phase methanol synthesis and ceramic
  membranes for gas separation are crucial to
  lowering the cost of production.
• All larger scales, conversion and power systems
  (especially the combined cycle) may have higher
  efficiencies.
• RD is necessary to verify and improve the
  performance.

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KEY PROCESS STEPS IN BIOMASS TO METHANOL AND H2
Methanol
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ExampleHynol Process

• This process produces H2 and methanol from
  biomass with reduced CO2 emissions. Steps
  involved
• Hydrogasification of biomass
• Steam reforming
• Methanol synthesis from Syn gas produced.

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Areas of Research and Development

• Feed stock preparation For thermochemical
  routes, variety and nature of feeds for high
  temperature and pressure reactors. For biological
  routes, pretreatment to increase accessibility.
• Gasification gas conditioning Key to
  utilization of H2 in fuel cells.
• In Gasification presence of Hydrocarbons, N2,
  sulfur, chlorine compounds must be addressed not
  only for end use applications shift gas reaction
  catalyst and separation systems such as PSA.
• System integration Integration of several
  steps, Techno-economics of process alternatives
  to match the optimum technology with the
  available feedstocks.

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• Modular systems approach There is an
  opportunity for biomass systems to address small
  scale and remote applications. These systems will
  require novel conversion and gas conditioning
  technologies, designed for the resources
  available in a particular region.
• Value Co-product integration Appropriate
  systems for conversion of by-product streams from
  chemical and biological conversion of biomass,
  are the best prospect for near-term development.
• Larger-scale demonstration Most promising
  technologies will need to be selected at larger
  scale with successful utilization of H2 (i.e.
  fuel cells, IC engines, turbine etc.)
• There are other challenges of storage and
  utilization technologies.

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ISSUES

• Since H2 content in Biomass is low the yield of
  H2 is low (Approx. 6 vs. 25 of CH4)
• Energy content of biomass is also low due to 40
  O2 content.
• Low energy content of biomass is inherent
  limitation of the process since over half of H2
  from biomass comes from splitting of water in
  steam reforming.

continued
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ISSUES

• Even at reasonable high efficiency, production of
  H2 from biomass is not presently economically
  competitive with natural gas steam reforming
  without the advantage of high-value co-products,
  very low cost biomass and potential environmental
  incentives.
• There are no completed technology demonstrations.

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THANK YOU