Abstract Palm oil is one of the most rapidly expanding equatorial crops, which is suitable for feedstock of biodiesel production. In this work, production of methyl esters from palm oil transesterification in a microwave heated continuous flow system was investigated. Choline hydroxide (ChOH) was employed as a green ionic liquid catalyst. The oil to methanol molar ratio, flow rate, power of the microwave, and catalyst loading were varied and optimized by response surface methodology combined with the Box-Behnken design of experiments for maximum biodiesel yield. The ionic liquid proved to be effective in tranesterification of palm oil. The quadratic regression model can be used to forecast the resulting methyl esters content. The optimum condition was identified at molar ratio between oil to methanol of 1:13.2, flow rate of 20 ml/min, microwave power of 800 W and catalyst loading of 6% (w/w), giving the methyl esters content almost 90% in EN 14103 standard test. In addition, most properties of the biodiesel considered were observed to meet the fuel specifications from the ASTM D6751 and Thai standards (community use). Reusability of the ionic liquid for several times was demonstrated before it was contaminated and decomposed, leading to a marked drop in catalytic activity.

中文翻译：

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在微波加热连续流动反应器中使用 ChOH 离子液体将棕榈油酯交换为生物柴油

摘要 棕榈油是赤道地区发展最快的作物之一，适用于生产生物柴油的原料。在这项工作中，研究了在微波加热连续流系统中通过棕榈油酯交换生产甲酯。氢氧化胆碱 (ChOH) 用作绿色离子液体催化剂。油与甲醇的摩尔比、流速、微波功率和催化剂负载量通过响应面方法结合 Box-Behnken 实验设计进行改变和优化，以获得最大的生物柴油产量。离子液体被证明在棕榈油的酯交换中是有效的。二次回归模型可用于预测所得甲酯含量。确定最佳条件为油与甲醇的摩尔比为 1:13.2，流速为 20 ml/min，800 W 的微波功率和 6% (w/w) 的催化剂负载，使 EN 14103 标准测试中的甲酯含量接近 90%。此外，观察到的生物柴油的大多数特性符合 ASTM D6751 和泰国标准（社区使用）的燃料规格。在离子液体被污染和分解之前，证明了离子液体的可重复使用性，导致催化活性显着下降。