Immobilization Of Lipase On Novel Chitosan Carirer And Synthesis Of Biodiesel From Waste Oil

With the worldwide shortage of fossil energy and environmental pressure, as a typical sustainable energy source, biodiesel has become more attractive recently due to its environmental friendliness. Enzymatic synthesis of biodiesel has become a prime interest in recent works owing to mild reaction conditions, low energy consumption, simple post-processing and non-pollutant emissions. The industrialization of biodiesel is limited by high production cost, short lifetime of lipase, long reaction time, low catalytic efficiency. In this article, the immobilization of lipase and process of biodiesel production with waste oil are investigated to reduce production cost, enhance productivity.1. In this paper, the macroporous resin was used as the carrier,10mg/mL chitosan was first attached to macroporous resin, and then was cross-linked through glutaraldehyde0.125%(resin). Lipase immobilized on the carrier kept4100U/g when the immobilization condition was:lipase loading10%(carrier), isooctane,4℃for5h. SEM and FT-IR demonstrated the surface of resin attached with chitosan was smooth, and the surface of immobilized lipase had obvious embossment. Compared with free lipase, immobilized lipase showed good storage, thermal stability and tolerance to organic solvents. Olive oil hydrolysis remained65%after10cycles in batch operation.2. The catalysis of immobilized lipase for the production of biodiesel from soybean oil containing fatty acids was conducted. The results showed when the lipase quantity for8%, the water quantity for6%, the hexane quantity for0.5mL/g, the molar ratio of methanol and oil3:1, methanol added equally by three-step (0h,5h,10h), reaction time for15h, temperature40℃, the esterification achieved more than80%. The immobilized lipase kept its activity after reused over6times.3. The preprocessing procedure of illegal cooking oil was studied. The optimal treatment conditions could be obtained:certain impurities and phospholipid of the illegal cooking oil was removed by centrifugation and deguming. The illegal cooking oil was bleached for30min at60℃with5%hydrogen peroxide based on illegal cooking oil weight, then was treated for20min at70℃with5%mixed adsorbent (the ratio of active carbon and bentonite is1:1) based on illegal cooking oil weight. By several steps processing the quality of illegal cooking oil had a significant improved.4. The production of biodiesel from illegal cooking oil was catalyzed by immobilized lipase. Based on batch process conditions, a self-designed circulation reactor was developed to conduct the transesterification, the result showed that:lipase density0.2g/mL, flow velocity0.6mL/min, the reaction time of12h, the biodiesel conversion could be up to90%. Compared with batch process, continuous process can be more suitable for the industrialized production of biodiesel.