Kusdiana Dadan, Saka Shiro
Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
Bioresour Technol. 2004 Feb;91(3):289-95. doi: 10.1016/s0960-8524(03)00201-3.
In the conventional transesterification of fats/vegetable oils for biodiesel production, free fatty acids and water always produce negative effects, since the presence of free fatty acids and water causes soap formation, consumes catalyst and reduces catalyst effectiveness, all of which result in a low conversion. The objective of this study was, therefore, to investigate the effect of water on the yield of methyl esters in transesterification of triglycerides and methyl esterification of fatty acids as treated by catalyst-free supercritical methanol. The presence of water did not have a significant effect on the yield, as complete conversions were always achieved regardless of the content of water. In fact, the present of water at a certain amount could enhance the methyl esters formation. For the vegetable oil containing water, three types of reaction took place; transesterification and hydrolysis of triglycerides and methyl esterification of fatty acids proceeded simultaneously during the treatment to produce a high yield. These results were compared with those of methyl esters prepared by acid- and alkaline-catalyzed methods. The finding demonstrated that, by a supercritical methanol approach, crude vegetable oil as well as its wastes could be readily used for biodiesel fuel production in a simple preparation.
在用于生物柴油生产的脂肪/植物油的传统酯交换反应中，游离脂肪酸和水总是会产生负面影响，因为游离脂肪酸和水的存在会导致皂的形成，消耗催化剂并降低催化剂的有效性，所有这些都会导致转化率较低。因此，本研究的目的是研究水对甘油三酯酯交换反应和脂肪酸甲酯化反应中甲酯产率的影响，这些反应由无催化剂的超临界甲醇处理。水的存在对产率没有显著影响，因为无论水的含量如何，总是能实现完全转化。事实上，一定量的水的存在可以促进甲酯的形成。对于含水的植物油，发生了三种类型的反应；在处理过程中，甘油三酯的酯交换反应和水解反应以及脂肪酸的甲酯化反应同时进行，以产生高产率。将这些结果与通过酸催化和碱催化方法制备的甲酯的结果进行了比较。研究结果表明，通过超临界甲醇方法，粗植物油及其废料可以很容易地用于生物柴油燃料的生产，制备过程简单。
