山苍籽核仁油合成生物柴油研究

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SO_4~2-/ZrO_2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,得到合成牛物柴油的优化工艺条件.研究结果表明,固体酸SO_4~(2-)/ZrO_2催化酯化反应的最佳条件为:油重4%的SO_4~(2-)/ZrO_2,醇油摩尔比为10:1,温度为68℃,反应时间为4 h,原油酸值降到2.52 mg/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15 min,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.

Preparation of biodiesel from litsea cubeba kernel oil

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 SO_4~2-/ZrO_2, and then the first reaction product was transesterified with methanol catalyzed by the phase transfer catalyst of hexadecyl-trirnethyl-ammonium bromide (CTMAB)/NaOH.The results show that the optimal parameters of esterification are as follows: 4% of SO_4~2-/ZrO_2, 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-ammoniurn 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.