采用超临界甲醇法制备大豆生物柴油

Production of Soybean Bio-diesel by Supercritical Methanol

分析了超临界技术制备生物柴油的反应机理,重点阐述了温度、醇油比、压力、水和游离酸对超临界法制备生物柴油的影响。与其他化学法相比,超临界甲醇法的反应时间从1￣8h降低到4min,对原料油的要求也低,可使水含量及酸值较高的废油,未经处理即可制得转化率为98%以上的生物柴油。论述了反应机理,展望了超临界技术制备生物柴油的工业应用前景,并对超临界技术制备生物柴油的研究提出了建议。研究表明,采用超临界技术制备生物柴油,在反应时间、对原料要求和产物回收等方面均具有传统碱催化法无法比拟的优势。

The reaction mechanism of bio-diesel preparation by supercritical fluid technology is investigated. Some factors affecting the transformation reaction, such as temperature, mole ratios of alcohol to plant oil, pressure, water and free fatty acids, are presented emphatically. Compared with enzymic and chemical methods, supercritical methanol method not only reduces reaction time from 1-8 h to 4 min. but also needs less pretreatment for the fatty acids. Without any prereatment, nearly 98 waste oil with high acid value can be turned into biodiesel. Some factors affecting the transformation reaction are presented ： temperature, fatty acids, water, different alcohols and mole ratios of alcohol to plant oil. In addition, the future of bio-diesel production in supercritieal methanol are also discussed, and some adviees about the study of bio-diesel preparation by supcrcritical method are suggested. Compared with traditional methods, supercritical methanol method is a more attractive method.