Experimental Study On Transesterification Of Plant Oil To Produce Biodiesel Catalyzed By Novo435

Biodiesel, fatty acid alkyl ester, is made from renewable bioenergy such as vegetable oils and animal fats. Although conventional chemical technology using alkaline catalysts has been applied to the industrial production of biodiesel fuel, there are several drawbacks to this approach, including excessive methanol, high energy consumption, difficulties in the recovery of products, environmental pollution caused by lye exclusion, strict requests for material and so on, and all of them reduce exorbitant cost. Compared with those, the enzymatic transesterification of biodiesel attracts widely attention because of circumventing these problems and lots of advantages, such as mild reaction conditions, low dosage of alcohol, easy recovery of products and no waste production and so on. Presently, the domestic studies about the enzymatic transesterification mainly concentrate on the soybean oil so far reported, and other rich feedstock still doesn't touch. Based on this context, the transesterification conditions from rapeseed oil and tung oil by the immobilized lipase Novo435 were studied in this paper, aimed to find the optimum reaction condition and preliminarily decrease the production of biodiesel. The effects of influences in the reaction such as the amount of catalyst, the molar ratio of methanol to oil, temperature, the rate of rotation, time and the water content were investigated respectively by single factor and then response surface methodology in detail, moreover, the preliminary studies of the adding way of methanol and reaction batch on lipase were made. The results show that the optimal reaction conditions of rapeseed oil are the rotation rate 200rpm, the molar ratio of methanol to oil 1.5:1,the reaction temperature 50℃ and 10% lipase amount(based on oil weight), by which the transesterification degree can reach 48%(theoretic 50% convention rate of oil) after 10h. Water addition is not favorable for the reaction. A three-step transesterication will be available: 1.5, 0.75 and 0.75 molar equivalent of methanol was successively added at reaction time of 0, 10, 26h, by which the transesterication degree could reach up to 95%, and after continuous reaction of 400h there are not apparent decrease of the lipase effect. Meanwhile, the optimal reaction conditions of tung oil are the rotation rate 200rpm, the molar ratio of methanol to oil 2.2:1 ,the reaction temperature 43 ℃ and 14% lipase...