生物柴油的生产技术

Manufacture Technologies of Biodiesel

综述了生物柴油生产的原料、催化剂和生产工艺等相关研究进展。介绍了生物柴油的生产几乎可以采用所有的天然油脂作为原料,原料的来源对其性质有一定的影响。目前生物柴油工业化生产工艺主要是均相的酸、碱催化酯交换反应,很多都是在常压、低温下进行。均相酸碱催化剂的优点是反应转化率高,但是废催化剂会带来环境问题。非均相催化剂和酶催化剂则是目前研究的热点,固体碱、固定化酶等催化剂可以很容易从反应产物中分离出来。高温高压技术、超临界技术等被用于酯交换反应过程,反应可以在数分钟内完成。高速乳化技术、超声技术及微波技术等反应强化手段可以改善酯交换过程中的传质过程,有利于不完全互溶的醇油两相进行反应。

The article reviewed the progresses about materials, catalysts and production technologies of biodiesel production. Biodiesel, derivated from natural oil and fat, is an environmental benign alternative of fossil fuel production. The origin of oil/fat influences, more or less, on the properties of biodiesel. (Transesterification) is the standard method to manufacture biodiesel. Commercially used catalysts are (homogeneous) acids or bases. Most of the processes operate under atmospheric pressure and moderate (temperature.) They have rather high oil conversion. However, the seperation of waste catalysts brings about some enviromental problems. More and more researches focused on heterogeneous catalysts and enzyme (catalysts.) The heterogeneous catalysts can be easily separated from the product. Many new technologies, such as elevated temperature and pressure technique, supper critical technique, can greatly accelerate the transesterification reaction of biodiesel production. The reaction can complete in few minites. Because the reaction is conducted between two methanol/oil phases, it can be significantly enhanced with high speed shearing, ultrasounic and microwave techniques by (improving) the mass transfer.