微藻原位萃取-酯交换法生物柴油的制备

Preparation of biodiesel from microalgae by in-situ transesterification

油脂萃取是许多生物柴油制备过程中的重要步骤.原位萃取-酯交换法可以将蛋白核小球藻藻粉直接的转化为生物柴油避免了单独从藻粉中萃取油脂.研究了以蛋白核小球藻藻粉和甲醇为原料,在浓硫酸作催化剂的条件下原位萃取-酯交换法制备生物柴油的工艺.考察了不同工艺条件对产率的影响.其适宜的反应条件为:用水量和藻粉质量比为1∶1,反应温度为65℃,催化剂用量为藻粉质量的3%,甲醇用量和藻粉质量比为8∶1,酯交换反应在8 h内完成.结果表明:以干藻粉质量为基准微藻粗生物柴油收率可达到16.0%,由高效液相色谱分析得知微藻粗生物柴油中生物柴油量为43.5%,以干藻粉质量为基准微藻生物柴油总收率为6.96%.

The extraction of oil is a primary step in biodiesel production system, but in-situ transesterification method can directly convert the chlorella pyrenoidosa powder into biodiesel, skipping the step of oil extracting. In this paper, biodiesel was prepared via in-situ tramesterification method using methanol as solvent,chlorella pyrenoidosa algae as precursor and sulfuric acid as catalyst. The effects of different process conditions on the biodiesel yield were investigated. The optimal conditions for the reaction were mass ratio of water to algae powder of 1∶1, mass fraction of catalyst(sulphuric acid)of 3%, reaction temperature of 65 ℃, mass ratio of methanol to algae powder of 8∶1 and reaction time of 8 h. The results show that the conversion rate of algae powder to crude microalgae biodiesel is 16.0%, the content of biodiesel in crude microalgae biodiesel is43.5% and the conversion rate of algae powder to microalgae biodiesel is 6.96%.