No description available.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on July 10, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Mechanical Engineering, University of Alberta." Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains v, 126 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 59-69).

Thesis (M.S.)--University of Alabama at Birmingham, 2006. / Description based on contents viewed Jan. 29, 2007; title from title screen. Includes bibliographical references (p. 42-44).

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.

Thesis (Ph. D.)--Brigham Young University Dept. of Chemical Engineering, 2006. / Includes bibliographical references (p. 141-150).

Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (p. 108-112). Also available via the World Wide Web.

No description available.

Tars have been identified as one of the major impurities associated with the utilization of biomass gasification fuel gas. Tars may result in blockages, plugging, corrosion and catalyst deactivation, leading to serious operational and maintenance problems during biomass gasification. Therefore, tar removal is essential to insure economic and effective fuel gas utilization. This study investigates the catalytic activity of zeolites, and nickel-supported zeolites for tar removal. Tests were conducted using a bench scale reactor and naphthalene as a model tar compound. Zeolites with varying pore sizes and acidity were tested to evaluate the effect of pore size and acidity on tar removal. Test results suggested that the catalytic activity increased with an increase in pore size and the number of acidic sites on the zeolite. The steam reforming ability of nickel towards naphthalene removal was evaluated by impregnating nickel on zeolites; this impregnation improved the activity of the catalysts significantly. Long term catalytic activity tests were performed, which showed that nickel supported ZY-30 and ZY-80 had the best naphthalene conversion, with naphthalene conversions of greater than 99%, followed by nickel- supported ZY-5.2, SiO2/Al2O3, and chabazite, respectively. This study also evaluated the catalytic activity of montmorillonite and nickel- supported montmorillonite as tar removal catalysts. Montmorillonite, and Ni-montmorillonite were tested for their efficiency in reforming tars. Also, the efficacy of nickel-supported montmorillonite catalyst was tested as a function of nickel content, reaction temperature, naphthalene loading, and the steam to carbon ratio. The results demonstrated that montmorillonite was catalytically active in removing naphthalene. In addition, Ni-montmorillonite had very high activity towards naphthalene removal via steam reforming, with removal efficiencies of greater than 99%. The activation energy was calculated for Ni-montmorillonite assuming first order kinetics and was found to be 84.5 kJ/mole. Long-term activity tests showed that the catalyst was active with naphthalene removal efficiencies of greater than 95%, which were maintained over a 97-hour test period. Very little loss of activity was observed with a drop in removal from 97 to 95%. The drop in catalytic activity was attributed primarily to a decrease in catalyst surface area, nickel sintering, and coke formation.

Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 194-196). Also available via the World Wide Web.