Research Of Biodiesel Production Catalyzed By Acidic Ionic Liquid

As a kind of green, recyclable, and environmental-friendly energy, biodiesel is the best choice of fossil fuel’s substitution in the future. However, due to some problems like high cost and low conversion, biodiesel has not been used industrially on a large scale.This thesis is using algae to produce biodiesel aiming to provide theoretical basis for the industrial utilization of algal biodiesel. In this thesis, four points are discussed: Chlorella cell wall breaking, Chlorella lipid extraction, catalytic effect of acid ionic liquid [Hmim]HSO4on biodiesel production, and catalytic effect of three heterpolyanion-based ionic liquids [Hmim]4PMo11VO40,[Hmim]5PMo10V40, and [Hmim]6PMo9V304o on biodiesel production. The main research contents are as follows:(1) Use ultrasonic method, oscillametric method, high temperature and high pressure, and microwave method to break the Chlorella cell wall. The results show that ultrasonic method is obviously better than the other three methods. Cell wall broken rate can reach75.3%when processing duration is10min.(2) Use ethyl ether, petroleum ether, and n-hexane to extract lipid from Chlorella cell by Soxhlet extraction and study the effects of extraction time and temperature. The results show that extraction efficiency increases with the increase of extraction time and temperature. No obvious distinction is found among three extraction agents, ethyl ether has the highest extraction efficiency9.97%when extraction time is12h and extraction temperature is90℃.(3) Prepare acid ionic liquid [Hmim]HSO4for catalyzing transesterification. The results show that the optimum reaction condition is as follows:reaction time7h, reaction temperature70℃, catalyst dosage7%, and molar ratio of methanol to lipid9:1. Under these conditions, the biodiesel yield is65.4%.(4) Prepare heteropolyanion-based acid ionic liquid [Hmim]4PMo11VO40,[Hmim]5PMo10V2O40and [Hmim]6PMo9V3O40for catalyzing transesterification. The results show that the optimum reaction condition is as follows:reaction time7h, reaction temperature70℃, catalyst dosage7%, and molar ratio of methanol to lipid9:1. Catalytic efficiency of three catalysts increases orderly. Under these conditions, the biodiesel yields of three catalysts are69.4%,72.2%, and75.0%, respectively.