用于生物柴油生产的固体碱催化剂CaO的低温活化

Low-temperature Activation of the Aolid Base Catalyst CaO for Biodiesel Production

分别研究了甲醇、甘油和水三种不同的活化剂对固体碱催化剂CaO在制备生物柴油中的活化作用,考察了活化时间对CaO活性的影响以及三种活化方式在空气中的耐失活能力,同时也探讨了三种活化方式的活化机理。结果发现:甲醇的活化效果不是很好,而甘油和水则对CaO有较好的活化效果,并且用水活化时不需要预先活化就有较高的活化作用;甘油活化后的CaO在空气中放置15d活性没有明显降低。无论是用甲醇、甘油还是用水来活化,它们对CaO活性的提高除了对酯交换反应体系的加速作用外,甲醇和水还有对CaO表面的去碳酸化作用,同时甘油还有去羟基化和去碳酸化作用。

Influences of methanol,glycerol and water on the activation of the solid base catalyst CaO in the biodiesel production were investigated respectively.In addition,the activation time,air tolerance and activation mechanism were also studied.The results showed that glycerol and water had better activation than methanol,the water with excellent activity on CaO even without pre-activation;and the catalyst CaO didn＇t have any activity loss even exposed in air for 15 days after the process of glycerol.The activation mechanism was that the activation agents,such as methanol,glycerol or water,accelerated the transesterification in biodiesel production,and the surface of CaO was decarbonated after the process of methanol or water,whereas the surface of CaO were dehydrated and decarbonated after the process of glycerol.