蛋白包覆微晶固定化脂肪酶的制备及催化合成生物柴油的研究

Preparation of protein coated micro-crystals and its application in biodiesel production

研究了蛋白包覆微晶固定化脂肪酶(PCMC)的制备和性质,并用于催化麻疯树油合成生物柴油.研究表明:以K2SO4为赋形剂、丙酮为脱水剂制备固定化脂肪酶PCMC,在40℃异辛烷中浸泡72 h后,PCMC活性可保持初始活性的70%;在80℃的异辛烷中浸泡4 h后,PCMC活性为初始活性的81%;通过催化月桂酸与正辛醇的酯化反应,考察了脂肪酶PCMC的酯化性能,重复使用9次后,月桂酸转化率可保持在61%以上.并进一步优化了脂肪酶PCMC催化麻疯树油制备生物柴油的反应条件,正己烷为溶剂,麻疯树油与正己烷物质的量之比为1∶2,醇油比为4∶1,酶用量为20%(基于麻疯树油质量),反应温度为50℃,反应时间12 h.在该条件下,生物柴油的最高产率为94%.

The PCMC was used to prepare immobilized lipase. The preparing conditions and stabilities of immobilized lipase were studied and the biocatalysts were used for biodiesel production from Jatropha oil. K2SO4 was used as excipient and acetone as water miscible organic solvent to prepare lipase PCMC. The obtained PCMC exhibited excellent stability and reusability. The PCMC retained 70% of its initial activity after incubating in iso-octane for 72 h, and retained 81% of the initial activity after incubating in iso-oetone at 80 ℃ for 4 h. The conversion of lauric acid can be retained more than 61% after 9 successive reaction cycles. The reaction parameter biodiesel production were optimized and the optimum conditions were as follows： molar ratio of Jatropha oil to n-hexane 1 ： 2, temperature 50 ℃, molar ratio of ethanol to oil 4 ： 1, the dosage of PCMC 20% （w/w PCMC to oil）. Under these conditions, the maximum biodiesel yield could reach 94%.