Reduction of free fatty acid of vegetable oil by immobilized lipase

Abstract

Due to the decreasing size of the crude oil resource in the world, there is an urgent need to search for new alternatives to meet the daily energy requirements. Among all the alternatives available, biodiesel is consider to have high potential and thus been the focus of many research studies. This is due to the advantage of biodiesel being renewable, biodegradable and environment friendly as there are less harmful substances such as sulphur compounds in the exhaust of biodiesel. Biodiesel is defined as the mono alkyl esters of long chin fatty acids derived from vegetable oil or animal fats, for use in compression-ignition engines. [1] For this project, the focus would be on the reduction of free fatty acid in vegetable oil by utilizing Pseudomonas cepacia lipase immobilized on modified zirconia support. Factors affecting the reaction such as the presence of co-solvent, concentration of methanol and water would be investigated. Experimental results indicate that the yield had a positive relationship with the methanol concentration provided that there was a solvent used as yield decreases by around 50 times in a solvent free system. In addition, water appears to have a positive effect on the yield. Based on the results obtained so far, the best experimental conditions is the use of zirconia support modified with stearic acid in the presence of 10% water which was able to produce yield of 70%. Future works includes increasing the loading of lipase on the support, studying of oil and free fatty acid system and recycling of the immobilized lipase.