固定化脂肪酶催化桐油制备生物柴油的研究

摘要

The preparation of biodiesel from tung oil catalyzed by magnetic Fe3O4 nano-particles containing immobilized lipase was studied,and the effects of dosage of borate buffer,dosage of enzyme,molar ratio of methanol to oil,reaction temperature and cleaning immobilized lipase or not on transesterification were investigated,and the operational stability of the immbilized lipase was studied.The results showed that under the conditions of volume ratio of hexane to tung oil 2∶ 1,molar ratio of methanol to oil 1 ∶ 1 at 0,5,12 h (total molar ratio of methanol to oil 3 ∶ 1),dosage of borate buffer 6％ (based on the volume of tung oil),dosage of enzyme 7.5 mg/mL (based on the volume of tung oil),cleaning immobilized lipase by acetone before adding methanol,reaction temperature 45 ℃,reaction time 26 h and rotational speed 200 r/min,the conversion rate of methyl ester reached 91.2％.The conversion rate of methyl ester still reached 84.1％ after ten batches reactions catalyzed by the immobilized lipase,and it indicated that the immobilized lipase had a certain value of industrial applications.%对磁性Fe3O4纳米粒固定化脂肪酶催化桐油制备生物柴油进行了研究,分步探讨了硼酸盐缓冲液用量、固定化酶用量、醇油摩尔比、反应温度、固定化酶清洗与否对转酯反应的影响,以及固定化酶的操作稳定性.结果表明:将正己烷与桐油体积比定为2∶1,然后加入与桐油等摩尔的甲醇、桐油体积6％的硼酸盐缓冲波及7.5 mg/mL(以桐油体积计)固定化酶,反应5h和12 h各加入与桐油等摩尔的甲醇(总的醇油摩尔比3∶1),并每次添加甲醇前用丙酮清洗固定化酶,45℃、200 r/min反应26 h后,甲酯转化率可达91.2％.该固定化脂肪酶连续催化10批次反应后,甲酯转化率仍然可达84.1％,具有一定的工业应用价值.