Jatropha Seed Oil Preparation Of Unsaturated Carboxylic Ester Efficient Catalyst Screening

Preparation of fatty acid methyl esters by transesterification process is usually carried out by homogeneous, heterogeneous and enzymatic catalytic techniques and also by supercritical method. While the homogeneous catalytic process easily leads to pollution, the enzymatic method is expensive and the lipase can be easily poisoned, and supercritical method demands special equipments due to operational constraints at high temperature and pressure.In allusion to the problems concerning methods mentioned above, we hoped to seek a solid-base catalyst with high activity, selectivity and good stability to heat in the heterogeneous catalytic method. The alkali metal and alkali earth metal oxides, acetic acid salts etc. were loaded onto the carriers, includingγ-Al₂O₃, CaO, MgO, ZnO etc., by impregnation method. The catalyst of better activity was identified by random screening. Bake-temperature, bake-time and ratio of catalyst which had a great influence on the preparation were optimized by orthogonal experiments to find the optimum preparation conditions, in order to screen out an effective solid-base catalyst. The effective catalyst was employed to catalyse the transesterification of crude oil of Jatropha curcas L., the yield of the fatty acid methyl esters was 93.6% under the conditions of the molar ratio of oil to methanol 1:10, the reflux reaction temperature, reaction time 5 h and a catalyst amount 2% of the raw material oil. The present operation is simple, and can directly lead to the formation of the fatty acid methyl esters and glycerol as by-product. No pollution has been found during all these processes.