Dissertation
SEQUENTIAL HYDROTHERMAL LIQUEFACTION OF YEAST BIOMASS AND SUBSEQUENT CATALYTIC HYDROTHERMAL DEOXYGENATION OF LIPID TO HYDROCARBON
Doctor of Philosophy (PhD), Washington State University
01/2014
Handle:
https://hdl.handle.net/2376/111077
Abstract
Fatty acids and their derivatives are considered to be promising precursors for producing diesel and jet-fuel range hydrocarbons. Oleaginous microbes, including algae, yeast, and fungi, are receiving increasing interest for use in fatty acid production due to their short life cycles, rapid growth rates, and high oil yields. An integrated hydrothermal process to produce hydrocarbon biofuels from microorganism was developed. This integrated process consisted of two major components: (i) two-step sequential hydrothermal liquefaction to produce bio-oil as well as carbohydrate and protein; (ii) hydrothermal catalytic deoxygenation of bio-oil to produce biofuel that is rich in hydrocarbon.
Hydrothermal liquefaction is considered to be a favorable process to produce bio-oil from aquatic biomass as it avoids the biomass-drying expenses. A unique two-step sequential hydrothermal liquefaction method was developed for concomitant extraction of lipid, protein and carbohydrates from the microbial biomass. In step 1, co-products such as carbohydrates and proteins were isolated; and in step 2, bio-oil rich in lipids was produced from the remaining biomass. Compared to the traditional hydrothermal liquefaction, separating valuable co-products helps to make the integral bio-oil production process economically.
The produced bio-oil from hydrothermal liquefaction tends to be viscous, tar-like, and contains significant amount of oxygen. Thus, the bio-oil needs to be deoxygenated as a part of further processing. The traditional hydrotreating method consumes a significant amount of H2. Therefore, a hydrothermal catalytic deoxygenation process was developed to deoxygenate fatty acid and bio-oil with in-situ self-sustaining H2. This method effectively converted more than 80% fatty acid to hydrocarbon with no external supply of H2. By investigating the reaction pathway and fatty acid and glycerol reforming, water-gas shift reactions were found as the major reactions for the in-situ H2 generation. Decarbonylation was found as the major route for fatty acid and bio-oil deoxygenation. Fatty acid reforming and hydrogenoloysis reactions were found as the major reactions for producing short-chain hydrocarbon (C8-C16).
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Details
- Title
- SEQUENTIAL HYDROTHERMAL LIQUEFACTION OF YEAST BIOMASS AND SUBSEQUENT CATALYTIC HYDROTHERMAL DEOXYGENATION OF LIPID TO HYDROCARBON
- Creators
- Chao Miao
- Contributors
- Shulin Chen (Advisor)Manuel Garcia-Pérez (Committee Member)Yong Wang (Committee Member)Oscar Marin Flores (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 146
- Identifiers
- 99900581532601842
- Language
- English
- Resource Type
- Dissertation