【作者】 周慧；

【导师】 梁斌；

【作者基本信息】 四川大学 ， 化学工艺， 2006， 硕士

【摘要】 传统柴油来源于石油,但是由于石油储量的下降以及燃烧对环境造成的污染,促使人们不断寻找可再生并且对环境友好的替代燃料,生物柴油应运而生。生物柴油是以可再生的植物油或动物脂肪等为原料制备的长链脂肪酸的低碳醇单酯。但目前生物柴油较高的价格影响了其广泛应用,采用廉价原料是降低生产成本的重要途径之一。本文以价格低﹑产量大的麻疯树油为原料,通过预酯化和酯交换两步反应制备生物柴油。预酯化反应是甲醇和原料油中的游离脂肪酸反应,从而降低原料油的酸值;酯交换反应利用预酯化后的酸值较低的原料油和甲醇反应制备生物柴油。为了深入了解反应特性以及麻疯树油甲酯和甘油对反应的影响,研究了麻疯树油﹑甲醇﹑麻疯树油甲酯﹑甘油的溶解情况,绘制了麻疯树油甲酯-甲醇-甘油﹑麻疯树油-麻疯树油甲酯-甲醇﹑麻疯树油-甘油-甲醇﹑麻疯树油甲酯-麻疯树油-甘油四个三元体系的相图。从相图研究中可以看出,当麻疯树油甲酯含量达到70%时,麻疯树油-甲酯-甲醇呈一相存在。甘油在油和甲酯中的溶解性较差,很容易从反应体系中分离出来,因此甘油对反应几乎没有抑制作用。本文系统考察了甲醇用量﹑催化剂用量﹑反应温度﹑反应时间等对预酯化和酯交换反应的影响。研究结果表明,甲醇用量对预酯化反应结果影响较大,当使用油质量的12%以上的甲醇时,反应进行1h后,酸值就可降至1.5mgKOH/gOil左右。反应时间和催化剂用量的影响次之。预酯化反应的适宜条件为:甲醇用量为麻疯树油质量的12%,使用油质量的1%的硫酸(98%)为催化剂,在70℃下反应2h,用15%油质量的甘油洗涤后酸值可以降至1mgKOH/gOil以下,使用蒸馏水和甲醇洗涤的效果也很好。预酯化后的麻疯树更多还原

【Abstract】 As fossil fuel reserves rapidly decline, renewable alternative fuels are more and more attractive. Biodiesel is renewable, biodegradable and environmentally benign. The use of biodiesel is growing quickly because of its excellent fuel properties. Biodiesel chemically consists of mono-alkyl esters of long chain fatty acid, which is often manufactured by trans-esterification of vegetable oils or animal fats with methanol.However, the price of the bio-diesel inhibits its popularity. Using cheaper feedstock is a major way to reduce the cost of the biodiesel.In this work, a kind of cheap, abundant raw material, Jatropha curcas L. oil was used to produce biodiesel through a pre-esterification, trans-esterification two-step reaction process. In the pre-esterification reaction, the free fatty acids in the feedstock were reacted with methanol to form esters, hereby resulted in reduction of the acid value (A?V). In the followed trans-esterification reaction, the processed Jatropha curcas L. oil with the lower acid value reacted further with methanol to produce biodiesel.Inter-solubility of the reaction components is essential data for the production design and process operation. The inter-solubility of FAME-methanol-glycerol, oil-FAME-methanol, oil-glycerol-methanol, and oil-FAME-glycerol in the range from 298.15K to 333.15K has been measured. Methanol is completely soluble in both FAME and glycerol, but insoluble in oil. With increasing the mass fraction of FAME,更多还原