Enzymatic Production Of Fatty Acid Methyl Esters And Extract Plant Sterols

Fatty acid methyl ester is an important chemical intermediates, mainly for the production of bio-diesel and surfactants. Bio-diesel is an environmentally green energy. Phytosterols are an important raw material for the production of steroid drugs. Both have very good market prospects. So there are economic and social benefits to produce bio-diesel and extract phytosterols from deodorizer distillate.The paper studies the process for producing fatty acid methyl ester and extracting phytosterol by using immobilized lipase. So the whole experiment can be divided into two parts, one for the production and separation of fatty acid methyl ester, the other for the extraction and purification of phytosterols.Experimental main contents are as follows:1. Comparing to the extraction methods at home and abroad and taking the environmental factors into consider, we determine to use lipase as a catalyst to extract physterols.2. Screening out the optimal transesterification experimental program.3. Discussion of the selection of the solvent which is used to refine phytosterols.4. Purified fatty acid methyl ester by distillation.In the production process of fatty acid methyl ester, the main affecting factors such as alcohol-oil ratio, enzyme amount, reaction temperature and time, water content was studied. Test results show that under the reaction conditions as followed: lipase amount of 10%(g/g), water content is 15%(ml/g) and adding methanol in batches, shaking at 30℃, for 2 hours, the life span of immobilized lipase up over 250h, the transesterification degree is 89.4% and the yield of phytosterols is 7.3%.Purification sterol products can be achieved by re-crystallization process, the optimal conditions for refining sterol are: the material to liquid ratio is 1:20(g/ml), crystal custody for 6 hours, the crystal growth temperature is 15℃, stirring at the speed at 10rpm. Under these conditions for refining, sterols, the average purity of phytosterols is 94.4%, yield is 77.66%.We can get more pure fatty acid methyl ester by distilling the transesterification products. Distillation conditions are as follows: collecting the 170～210℃fraction under (-0.095～-0.085)MPa vacuum, fatty acid methyl ester yield can reach above 90%.