Background
Production of renewable transportation fuels from biomass
has become an important priority to reduce the nation's dependence upon
imported oil and minimize the impact upon the environment. However, a
sustainable biofuels economy will require conversion processes that utilize the
lignocellulosic components of plants so as not to compete with food production.
[2] This research focuses on developing processes that use a variety of feed
stocks, such as agricultural residues, waste from forest thinning, and energy
crops. Biomass gasification combined with catalytic synthesis has the potential
to meet these criteria. This approach can potentially produce alcohols or Fischer-Tropsch
fuels from a variety of biomass sources. [3]
Key
to the economic viability of gasification/catalytic synthesis processes is the
production of a syngas with low concentrations of products which interfere with
the catalytic step, such as methane, tars and sulfur compounds. [4] Catalysts
play a role in producing clean gas. For instance, dolomite is a suitable
catalyst for the removal of hydrocarbons while Alkali catalysts reduce tars
significantly. Commercially available Nickel catalysts are effective at removal
of hydrocarbons and adjustment of syngas quality. [1] Developing an
understanding of the formation of these species as a function of feedstock is
critical for evaluating and optimizing gasification.
Methodology
In
this study, steam gasification will be conducted on pilot scale of mixed
hardwoods, corn Stover, switch grass and wheat straw. Process conditions such
as steam-to-biomass ratio and temperature are investigated and their effects
upon product formation. Real-time measurements of gaseous products will be
gathered, including sulfur compounds. The chemical composition of the tars
formed will be monitored in real time using a Molecular Beam Mass Spectrometer
(MBMS). The process and unit operations, operational lessons-learned, and results
from the experiments as they relate to the formation of undesirable products
will be discussed.
Benefits
The
research helps generate knowledge on processes for gasification wide variety of
agricultural lignocellulosic feed stocks and hence helping in design of
successful gasification units. This intern contributes a lot to advancement and
competitiveness of the gasification.
The
results of the study have also potential benefit in large scale development of
gasification reactors that produce better quality gas and hence contributing a
lot to increased use of gasification and biomass energy at national level.
The
research also generates knowledge on optimum values of steam to biomass ratio
and temperature to produce more and quality syngas. This helps determine the
economical variability of the technology and gives insights into the cost
reduction ways.
References
1. David Sutto
et.al, 2001, Review of literature on catalyst for biomass gasification, Fuel
processing technology, Elsevier publications
2. Biomass
research and development board, 2008, National biofuels action plan,
http://www1.eere.energy.gov/biomass/ as accessed Nov 2, 2009
3. Rapagna S
et.al, 1998, Catalytic gasification of biomass to produce
hydrogen rich gas, Volume 23, No.7, Elsevier
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