超声作用下碱催化大豆油酯交换反应制备生物柴油

采用低频率超声（40kHz）强化KOH催化大豆油和甲醇酯交换反应制备了生物柴油。结果表明，超声空化作用的传质和乳化效果较传统机械搅拌作用显著。不同超声功率对酯交换反应的强化作用不同，超声功率60-80W对生物柴油制备影响显著。此外，超声作用下酯交换反应时间大大缩短，催化剂和甲醇的用量也有所减少。在催化剂用量为1．0％、醇油摩尔比为6：1、45℃水浴条件下，超声作用10min，甲酯含量高达99％。

Alkali-Catalyzed Transesterification of Soybean Oil for Biodiesel Production by means of Ultrasonication

The transesterification of soybean oil with methanol, in the presence of potassium hydroxide as catalyst, by means of irradiation of low frequency uhrasound(40 kHz) was studied. It was found that cavitation of ultrasonication had more effect on mass transfer and emulsion of methanol/soybean oil (M/O) than that of conventional mechanical agitation. Different ultrasonic powers had different effects on the reaction (methanol and soybean oil), the ultrasonic power from 60 W to 80 W had significant effects on biodiesel production. It also was found that the reaction time was much shorter than that of conventional mechanical agitation, meanwhile,amount of the catalyst and methanol was reduced. Under this proper low ultrasonic frequency, the methyl ester content achieved almost 99% in 10 minutes at the water bath temperature 45℃ with molar ratio of methanol to soybean oil 6:1 and KOH mass fraction 1.0%.