Biodiesel production from rapeseed oil using supercritical methyl acetate with water addition has been developed to attain a higher biodiesel yield than that of supercritical methyl acetate without water. We newly constructed a plug flow reactor for the supercritical reaction usage system. We examined the effect of process variables by utilizing response surface methodology to optimize the process. As a result, the maximum biodiesel yield of 97 wt% was achieved at water addition of 8.2 wt%, reaction temperature of 578 K, and space time of 30 min. From the pseudo-first order reaction model, it was found that water addition under supercritical methyl acetate escalates reaction rate and reduces the activation energy of the reaction. The water addition improved the thermodynamics activation parameters, including enthalpy, entropy, Gibb’s energy, and equilibrium constant based on the transition-state theory. The thermodynamics activation parameters obtained show that the reaction was endothermic and unspontaneous.

已经开发了使用超临界乙酸甲酯加水由菜籽油生产生物柴油，以实现比不加水的超临界乙酸甲酯更高的生物柴油收率。我们为超临界反应使用系统新建了活塞流反应器。我们通过利用响应面方法优化过程来检查过程变量的影响。结果，在添加8.2重量％的水，578K的反应温度和30分钟的时空时，获得了97重量％的最大生物柴油产率。从拟一级反应模型发现，在超临界乙酸甲酯下加水会提高反应速率并降低反应的活化能。加水改善了热力学激活参数，包括焓，熵，吉布能，和基于过渡态理论的平衡常数。所获得的热力学活化参数表明该反应是吸热的且不自发的。