山苍籽核仁油合成生物柴油研究

Preparation of biodiesel from litsea cubeba kernel oil

以山苍籽核仁油为原料,采用固体酸催化酯化-相转移催化酯交换反应合成生物柴油。从固体酸SO42-/ZrO2为催化剂进行酯化反应降低酸值,以十六烷基三甲基溴化铵(CTMAB)/NaOH为相转移催化剂进行酯交换反应,得到合成生物柴油的优化工艺条件。研究结果表明,固体酸SO42-/ZrO2催化酯化反应的最佳条件为:油重4%的SO42-/ZrO2,醇油摩尔比为10-1,温度为68℃,反应时间为4h,原油酸值降到2.52mg/g;该法相对浓硫酸催化酯化法具有不需耐酸设备、催化剂易回收、无废水排放等优点;相转移催化酯交换反应的最佳条件为:温度为25℃,0.5%的十六烷基三甲基溴化铵,油重1%的NaOH,醇油摩尔比为6-1,反应15min,原油酯交换率达到97.6%;采用相转移催化技术,反应在常温下进行,大大减少了能耗,缩短了反应时间,具有的产业化前景。

The production technology of biodiesel from litsea cubeba kernel oil with solid acid-esterification and phase transfer catalyst-transesterification was studied. First, litsea cubeba kernel oil was esterified with methanol catalyzed by solid acids SO42-/ZRO2, and then the first reaction product was transesterified with methanol catalyzed by the phase transfer catalyst of hexadecyl-trimethyl-ammonium bromide （CTMAB）/NaOH. The results show that the optimal parameters of esterification are as follows： 4% of SO42-/ZRO2, molar ratio of methanol to litsea cubeba kernel oil 10：1, 68 ℃ of reaction temperature and 4 h of reaction time, the acid value decreases to 2.52 mg/g. Compared with the traditional acidic-catalyzed method, this method has the advantages of no acid proof equipment, easy to recycle catalyst and no acidic waste water emission. The optimal parameters of transesterification are as follows： 25 ℃ of reaction temperature, 0.5% of hexadecyl-trimethyl-ammonium bromide, 1% of NaOH, molar ratio of methanol to the oil 6：1 and 15 min of reaction time. The ester exchanging rate is 97.6%. This method adopts phase transfer catalyst and produces industry prospect, which has many advantages such as energy-saving and time-saving under room temperature.