毕业设计（论文）-植物籽油制备生物柴油的工艺研究.doc

植物籽油制备生物柴油的工艺研究
摘要
由于环境问题和能源问题的日益严重,对可再生能源的开发已经逐步成为当今科学研究的热点。生物柴油是以动、植物油脂以及废弃的油脂为原料与甲醇经酯交换反应制备的新型替代能源,其主要成分是脂肪酸甲酯。生物柴油具有粘度低、闪点高、十六烷值高、无毒和可生物降解等优点,而且可以减轻大气的温室气体浓度。对解决地球升温、酸雨问题、改善人类的生存环境、实现经济的可持续发展具有重要的意义。
本课题以油树籽油为原料油,采用酸、碱催化剂经“两步法”工艺将“油树”籽油转化为生物柴油,即先用酸催化剂催化油树籽油中的游离脂肪酸转化为脂肪酸甲酯,经过预酯化反应将原料油的酸值降低到碱催化剂适宜的范围后,再以碱催化剂催化脂肪酸甘油酯经酯交换反应生成生物柴油。本课题主要分为三个步骤来研究:
第一、与以其他油品为原料来合成生物柴油的工艺参数做比较得出该工艺的最优参数范围为:最适醇油比的范围为4 :1~12:1,%~%,反应温度的范围为50℃~65℃和反应时间的范围为90min~180min。
第二、假定反应时间为180min ,通过单因素法设计出13组实验粗略得出植物籽油制备生物柴油的最优工艺参数为最适醇油比为6 :1,%,反应温度60℃。
第三、在此基础上通过三因素三水平Box-Behnken实验设计法设计出13组实验得出该工艺的最优工艺参数为::1,%,反应温度为63℃,反应时间为60min。
关键词: 生物柴油,最适醇油比,催化剂的用量,反应温度,反应时间
STUDY ON THE PRODUCTION OF BIODIESEL
FROM PLANT SEED OIL
ABSTRACT
As environmental issues and energy crisis e serious, developing renewable energy has gradually caught much more attentions. Biodiesel is an alternative to petroleum fuel. It can be produced by trans-esterification of vegetable oil, animal fat, or recycle greases with methanol in the presence of a catalyst. The ponent in the biodiesel is fatty acid methyl esters. Biodiesel has various advantages including low viscosity, high flash point, high cetane number, non-toxic and biodegradable. Furthermore, the concentrations of greenhouse gases in atmosphere can be reduced by using the biodiesel as motor fuels. It is of a great significance for solving the global warming and acid rain, improving the human environment and achieving sustainable economic development.
In this study, cornus macrophylla oil was utilized as feedstock. The biodiesel was produced with a two step trans-esterification. The first step of the process was to convert free fatty acid to fatty acid methyl esters in the presence of acid catalyst. After the pre-esterification, the acid value of oil was dropping down to the suitable range, and then in the second step the triglyceride was converted to the fatty acid methyl esters by trans-esterification in the pre