Theses and Dissertations

Yan Luo

Issuing Body

Mississippi State University

Advisor

Shmulsky, Rubin

Committee Member

Yu, Fei

Committee Member

DuBien, Janice

Committee Member

Steele, Philip H

Committee Member

Hassan, El Barbary M

Other Advisors or Committee Members

Borazjani, Abdolhamid

Date of Degree

12-11-2015

Document Type

Dissertation - Open Access

Major

Forest Resources

Degree Name

Doctor of Philosophy

College

College of Forest Resources

Department

Department of Sustainable Bioproducts

Abstract

Future predicted shortages in fossil fuel resources and environmental regulations from fossil fuel combustion have led to great research interest in developing alternatives to fossil fuels. Biomass-derived bio-oils will have the potential to replace conventional transportation fuels because of their sustainability and environmental advantages. However, the presence of high percentages of chemical oxygenates cause negative properties such as high water content, low volatility, lower heating value, corrosiveness, immiscibility with fossil fuels and instability during storage and transportation. Moreover, polymerization, esterification, condensation and other reactions occur between these highly reactive oxygenates in bio-oil (Diebold 2000). These negative properties hinder both bio-oil direct use as a fuel and the fuel conversion process (Mohan, et al. 2006). Hydrodeoxygenation has proven itself effective in converting of bio-oil to pure hydrocarbons. However, the large consumption of expensive hydrogen prevents the industrialization of bio-oil. Therefore, development of more efficient hydrodeoxygenation approaches with less capital cost will be desirable. The objective of this current research was to upgrade raw and distilled bio-oil by oxidation to a stabilized precursor to the final hydrocracking step of hydrodeoxygenation. In the second chapter, raw bio-oil, two pretreated bio-oils and hydrotreated bio-oil were hydrodeoxygenated to produce liquid hydrocarbons in the continuous reactor. In the third chapter, raw bio-oil, oxidized raw bio-oil, distilled bio-oil and oxidized distilled bio-oil were hydrodeoxygenated to liquid hydrocarbons with hydrogen in the batch reactor. In the fourth chapter, oxidized distilled bio-oil was hydrotreated with model syngas to organic liquid products followed by hydrocracking with hydrogen to produce liquid hydrocarbons. In the fifth chapter, oxidized distilled bio-oil was upgraded with syngas (H2/CO molar ratios of 4:6) in a single stage to produce organic liquid products. The resultant stabilities of these organic liquid products were investigated by application of accelerated aging. The research results showed that oxidized distilled bio-oil could be upgraded by the syngas in a single stage to produce stabilized bio-oil. This success will replace hydrogen by syngas for first stage hytrotreating and save shipping fee by transportation less weight of upgraded bio-oil rather than the bulky and high moisture content biomass.

URI

https://hdl.handle.net/11668/19006

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