Upgrading Bio-oil Over Solid Acid And Base By Catalytic Esterification

The research on alternative liquid fuel development has been carried out extensively as s result of rising price of international crude oil and tension of oil supply. Biomass pyrolysis is an efficient process of biomass conversion with high yield of liquid fuel, which makes biomass the most promising renewable energy to substitute the conventional fossil fuel. But the negative properties of bio-oil, such as the high viscosity, instability, severe corrosiveness and complicated composition put a lot of obstacles for its replacing process consequently, and have become a bottle-neck in its full applications. An urgent necessity to upgrade bio-oil is demanding. So the study in this dissertation combining bio-oil upgrading and catalytic esterification deserves great value and realistic significance.Among present bio-oil upgrading techniques, hydrodeoxygenation process needs complicated equipments, superior techniques and excessive cost and usually is halted by catalyst deactivation and reactor clogging. Although catalytic cracking is regarded as a cheaper route by converting oxygenated feedstocks to lighter fractions, the results seem not promising due to high coking and poor quality of the fuels obtained. Emulsification does not demand redundant chemical transformations, but the high cost and energy consumption input cannot be neglected. The accompanying corrosiveness to the engine and the subassemblies is inevitably serious. Based on the characteristic of high total amount (10-20wt%) and multi-organic acids existence, solid acid and solid base catalysts with high esterification activity were screened out and put into bio-oil upgrading investigation by esterification in order to lower the operation cost and improve the bio-oil quality.Solid acid "mix 40STS400" was chosen and accepted for its high esterification activity by model reaction of ethanol and acetic acid esterification. The physical characterization proved that the connection between high activity and crystalline phase composition, crystallographic state of Ti and existence of SiO₂. And the combination of tetragonal anatase TiO₂, orthorhombic crystal titanium oxide sulfate and cubic crystal titanium with highly-scattered and amorphous SiO₂ ensured the...