【作者】 丁宇琦；

【导师】 楼辉；

【作者基本信息】 浙江大学 ， 化学， 2011， 硕士

【摘要】 以天然植物油或动物油脂与甲醇、乙醇或者其它短链醇通过酯交换反应制备的生物柴油是一种环境友好的、可生物分解的无毒燃料。采用固体碱作为酯交换反应的催化剂避免了传统均相酸碱催化法催化剂分离困难,以及废水污染环境的问题,同时也克服了固体酸反应时间过长的问题。研究固体碱催化剂、酯交换反应过程的优化以及产品的性质对于生物柴油技术的发展和生物柴油的推广应用具有重要的意义。(1)本研究用共沉淀法制备了不同比例的La-Zr催化剂。利用X—射线衍射(XRD)对催化剂的晶相进行分析,结果表明催化剂经过高温焙烧后有新的晶相形成。利用CO2-程序升温脱附(C02-TPD)对催化剂的碱中心强度和碱中心数量进行分析,结果表明随着La：Zr比例的变化,催化剂碱中心强度和碱中心数量也发生改变。催化剂的活性与其碱中心的性质直接相关。研究了不同比例的La-Zr催化剂、醇／油摩尔比、催化剂用量、反应时间等因素对催化剂催化菜籽油—甲醇酯交换反应的影响。在焙烧温度为700℃,醇油质量比为2：1,反应时间为5 h的条件下,使用Zr1La10-700催化剂可以达到最高的脂肪酸甲酯的产率(96.3%)(2)通过溶胶凝胶法成功制备了介孔的0.1M/ZrO2(M=Li,Na,K,Mg,Ca)固体碱催化剂。催化剂的活性评价是用大豆油和甲醇的酯交换反应实现的。在该反应中,催化剂0.1Mg/ZrO2和0.1Ca/ZrO2没有表现出催化活性,而Li和K改性的Zr02催化剂上得到了高产率的生物柴油。在最佳反应条件下,在经过650℃焙烧过的0.1Li/Zr02的催化剂上,脂肪酸甲酯的收率高达98.2%。更多还原

【Abstract】 Biodiesel produced by the transesterification of natural oils with methanol, ethanol or other short-chain alcohols is an environmental benefits, biodegradable and nontoxic fuel. With a traditional homogeneous acid or base catalyst, the transesterification product is difficult to be separated and the waste water from washing catalyst may pollute environmental. Using a solid base catalyst can obtain pure product and avoid the problem of catalyst deposition.As the same time, the problem of long reaction time with solid acid catalyst is overcame.(1) A series of Zr1Lax catalysts with La/Zr molar ratio of 1,2,3,5, and 10 were prepared by co-precipitation method. X-ray diffraction patterns of the catalysts revealed that some new substance was created. The strength and amount of basic sites on the catalyst surface was measured by temperature-programmed desorption of carbon dioxide (CO2-TPD). CO2-TPD profiles showed that the density and amount of basic sites on the surface of the catalyst changed with the different mole ratio of La:Zr. The catalytic activity of the catalyst was associated with the alkalescence on the surface of the catalyst.The effect of the different mole ratio of La:Zr, methanol to oil molar ratio, catalyst amount and the reaction time on the transesterification process of rapeseed oil with methanol was investigated. A highest FAME yield of 96.3% was achieved on the Zr1La10 catalyst calcined at 700℃at a reaction time of 5 h.(2) Mesoporous 0.1M/ZrO2 (M=Li, Na, K, Mg, Ca) solid base catalysts were successfully synthesized by using a sol-gel method. The catalytic activities of the catalysts were tested via transesterification reactions of soybean oil with methanol. Both 0.1Mg/ZrO2 and 0.1Ca/ZrO2 catalysts showed no catalytic activity in this reaction, while Li, K modified ZrO2 catalysts achieved high yield of biodiesel production. Besides, under the optimum reaction conditions, a FAME yield of as high as 98.2% was achieved on 0.1Li/ZrO2 catalyst calcined at 650℃.更多还原