Catalytic fast pyrolysis of biomass for the production of fuels and chemicals |
Posted on:2011-12-14 | Degree:Ph.D | Type:Thesis |
University:University of Massachusetts Amherst | Candidate:Carlson, Torren R | Full Text:PDF |
GTID:2442390002466702 | Subject:Alternative Energy |
Abstract/Summary: | |
Due to its low cost and large availability lignocellulosic biomass is being studied worldwide as a feedstock for renewable liquid biofuels. Currently there are several routes being studied to convert solid biomass to a liquid fuel, which involve multiple steps at long residence times thus greatly increasing the cost of biomass processing. Catalytic fast pyrolysis (CFP) is a new promising technology to convert directly solid biomass to gasoline-range aromatics that fit into the current infrastructure. CFP involves the rapid heating of biomass (~500˚C sec-1) in an inert atmosphere to intermediate temperatures (400 to 600 ˚C) in the presence of zeolite catalysts. During CFP, biomass is converted in a single step to produce gasoline-range aromatics which are compatible with the gasoline of the current market. CFP has many advantages over other conversion processes including short residence times (2-10 s) and inexpensive catalysts. The major impediment to the further development of CFP is the lack of fundamental understanding of the underlying chemistry of the process.;The first goal of this thesis is to study the underlying chemistry of the CFP process using model compounds in a small pyroprobe micro reactor. For this part of the study the homogeneous thermal decomposition routes of glucose were identified along with the key intermediates. Through isotopic labeling studies the heterogeneous C-C bond forming reactions were determined. Lastly, the relative rates of the homogeneous and heterogeneous reactions were estimated.;Since CFP in the small pyroprobe reactor is not scalable the second part of the study focused on designing and building a bench scale fluidized bed reactor to demonstrate CFP on a larger scale. This fluidized bed reactor was used to optimize the CFP of pine wood with ZSM-5 catalyst. The effect of reaction conditions such as temperature and biomass space velocity on the aromatic yield and selectivity was determined. The long term stability of the catalyst was also studied. |
Keywords/Search Tags: | Biomass, CFP, Studied |
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