Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/83536
Title: Catalytic upgrading of biofuel
Authors: Lee, Hang Wai
Degree: Ph.D.
Issue Date: 2018
Abstract: In view of depletion of fossil fuel sources, it is in urgency to explore and develop renewable energy for substitution. In the past decade vast efforts have been devoted to the exploration of biomass derived energy sources, vegetable oils were found to be potential renewable energy sources however its application as transportation fuel was retarded due to its incompatibility with current engine design. Therefore biofuel upgrading processes such as cracking, transesterification and deoxygenation reactions (decarboxylation/decarbonylation/hydrodeoxygenation) were in great interest. Since biomass derived hydrocarbon could be compatible to our current engine thus deoxygenation reactions drew much attention and were interested by industrial sector. Extensive studies were focused on the development of heterogeneous catalytic system towards deoxygenation reactions however there was drawback that drastic conditions (>300oC) were often required. Therefore it was in great interest to develop homogenous catalyst to catalyze deoxygenation reactions under mild reactions. Numerous studies were done on exploration of homogenous catalyst such as palladium, rhodium, iridium and iron were found to be active towards decarbonylation of carboxylic acids. Palladium catalyst gave superior results however only biaryl ether phosphine ligand (DPEPhos, XantPhos) work well towards decarbonylation reactions. Thus in my study I would like to explore if there is another catalytic system towards decarbonylation of biomass derived compounds, in particularly fatty acids. During my exploration of feasible catalytic system for decarbonylation of carboxylic acids, indolylbisphosphine ligand was firstly reported for decarbonylation of long chain fatty acids. By employing 1mol% palladium-indolylbisphosphine catalyst, various carboxylic acids were converted to their corresponding alpha olefins in satisfied yields and selectivity. It was in doubt that whether monophosphine could be employed to catalyze decarbonylation leading to alpha olefins in good yield and selectivity. Therefore two sets of new developed monophosphine with quinolinyl and naphthyl scaffold were synthesized and employed to test for their catalytic activity. After optimizing reaction conditions, employing 1-3mol% palladium-monophosphine ligand could catalyze decarbonylation of various carboxylic acids into alpha olefins in good and selectivity. Glycerol, which is the by-product from biofuel refinery process, could be utilized as solvent and hydrogen source for catalytic transfer hydrogenation. During my study inexpensive commercial available 2-aminobenzyl alcohol was combined with [Ru(p-cymene)Cl₂]₂ as catalyst to catalyze transfer hydrogenation of ketones. Various kinds of aryl ketones, heteroaryl ketones, diaryl ketones as well as cyclic ketones were smoothly converted into alcohol in good yields by our catalytic system under mild condition (120℃) within 6-18 hours.
Subjects: Hong Kong Polytechnic University -- Dissertations
Biomass energy
Catalysis
Pages: xv, 178 pages : color illustrations
Appears in Collections:Thesis

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