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Date Permissions Signed

11-1-2011

Date of Award

2011

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Advisor

Bussell, Mark E.

Second Advisor

Gilbertson, John D.

Third Advisor

O'Neil, Gregory (Gregory W.)

Abstract

As the demand and price for crude petroleum continues to increase, unconventional sources of petroleum, including tar sands, oil shales, and bio-derived oils have become economically viable feedstocks. Previously, these oil reserves were deemed too costly to process into fuels due to the high impurity content (S, N, O) of the unrefined feedstocks. The decline in conventional oil reserves has focused increasing attention on utilizing these unconventional feedstocks. However, stringent environmental regulations governing fuel impurity content require refineries to remove these impurities in increasing amounts. Current hydrotreatment catalysts are unable to effectively remove theses impurities in sufficient quantities to meet government regulation. The goal of this research is to develop more effective hydrotreatment catalysts for upgrading unconventional feedstocks and producing ultra clean fuels. Previous research in the Bussell laboratory has shown that silica-supported nickel phosphide (Ni2P/SiO2) catalysts were highly effective at processing high boiling-point, organosulfur impurities and had excellent resistance to sulfur deactivation. In this research, several silica-supported noble metal phosphide catalysts were prepared and their hydrodesulfurization (HDS) and hydrodeoxygenation (HDO) properties were evaluated and compared with several commercial catalysts. Silica-supported rhodium phosphide (Rh2P/SiO2) had a higher dibenzothiophene (DBT) HDS activity than either silica-supported rhodium metal (Rh/SiO2) or rhodium sulfide (sulf. Rh/SiO2), and was also more active than a Ni-Mo/Al2O3 commercial catalyst. Due to limited active site densities in the as-prepared catalysts, silica-supported palladium phosphide (Pd3P/SiO2, Pd5P2/SiO2) catalysts were less active than the commercial Ni-Mo/Al2O3 catalyst. However, turnover frequencies (TOFs) and sulfur analyses of the HDS-tested palladium phosphides revealed high DBT HDS activity on a per site basis, and an increased resistance to sulfur incorporation compared to Pd/SiO2, suggesting a high HDS potential for the palladium phosphide catalysts if the site density can be optimized. Silica-supported ruthenium phosphides (RuP/SiO2 and Ru2P/SiO2) were also prepared and tested for furan HDO activity. Ru2P/SiO2 outperformed silica-supported ruthenium (Rh/SiO2) and RuP/SiO2 catalysts, as well as a Co-Mo/Al2O3 commercial catalyst, while exhibiting excellent selectivity toward C4 hydrocarbon products.

Type

Text

Publisher

Western Washington University

OCLC Number

768770422

Digital Format

application/pdf

Genre/Form

Academic theses

Language

English

Rights

Copying of this thesis in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Included in

Chemistry Commons

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