【作者】 梁华；

【导师】 周小平； 苏胜培；

【作者基本信息】 湖南大学 ， 化学工程， 2013， 硕士

【摘要】 乙酰丙酸甲酯(methyl levulinate)是重要的有机化工原料,可作为燃油添加剂和食品添加剂等广泛地应用于医药、涂料、香料和增塑剂等行业。本文从生物质出发,以甲醇为介质,实现了一步法催化玉米粉制备乙酰丙酸甲酯的工艺,具有一定的环保和应用价值。本文首先考察了不同种类的酸性金属盐催化剂在甲醇中催化玉米粉转化制备乙酰丙酸甲酯的催化性能,发现铝盐(硫酸铝)对反应的催化活性较高。在此基础上将几种不同种类的离子液体对硫酸铝催化玉米粉转化制备乙酰丙酸甲酯反应的协同催化作用进行了对比,优选出效果较好的离子液体[DMIM]HSO4。以硫酸铝做催化剂,在150℃的反应温度下反应3h,乙酰丙酸甲酯的收率最高可达到49.0%；离子液体的加入对硫酸铝的催化性能影响不大,未能明显提高乙酰丙酸甲酯的收率。本文还考察了几种不同阴离子的铝盐催化剂(甲基磺酸铝,苯磺酸铝,对甲基苯磺酸铝,十二烷基苯磺酸铝)催化玉米粉转化制备乙酰丙酸甲酯的催化性能,以及离子液体1,3二甲基咪唑硫酸氢盐([DMIM]HSO4)对这些铝盐催化剂性能的影响。考察了反应温度、反应时间、催化剂的用量、甲醇的用量、离子液体的用量等对反应的影响。实验发现离子液体[DMIM]HSO4对这些铝盐的催化性能均有一定的促进作用,尤其是对甲基磺酸铝和苯磺酸铝有明显的促进作用。当以Al(CH3SO3)3-[DMIM]HSO4作为催化剂,反应温度为150℃时反应3h(玉米粉；Al(CH3SO3)3:[DMIM]HSO4:无水甲醇的质量比为0.8：0.7：0.3：6),乙酰丙酸甲酯的收率最高达到57.3%。以Al(C6H5SO3)3-[DMIM]HSO4作为催化剂,反应温度为170℃,反应3h(玉米粉：Al(C6H5SO3)3:[DMIM]HSO4:无水甲醇的质量比为0.8：0.5：0.3：7),乙酰丙酸甲酯的收率最高达到58.0%。当反应中不加入[DMIM]HSO4,而以铝盐单独催化反应时,以对甲基苯磺酸铝催化效果最好,能得到乙酰丙酸甲酯的最高收率为53.1%。更多还原

【Abstract】 Methyl levulinate (MLA) is an important organic chemical,which is considered as a promising platform compound. It can be considered as fuel additive and food additives.It is widely used in medicine, paint, spices, plasticizer and other areas of chemical industry. In this investigation, environmentally green reaction was developed to convert starch to methyl levulinate in the presence of catalyst in methanol.Acidic metal salts catalysts were tested for the conversion of corn starch to methyl levulinate. Aluminum salts (aluminum sulfate) were found to give relatively higher methyl levulinate yield. Based on the investigation, several ionic liquids were tested as co-catalysts of aluminum sulfate to catalyze the topic reaction. It was found that 1,3-dimethylimidazole hydrogen sulfate ([DMIM]HS04) is a good co-catalyst of the aluminum salt. At optimum reaction conditions (150℃,3h), methyl levulinate yield of 49.0% was obtained in the presence of aluminum sulfate catalyst. Adding [DMIM]HSO4 into the aluminum salt (Al2(SO4)3·18H2O) catalysts improves the methyl levulinate yield.A series of aluminum salts with different anions, such as (Al(CH3SO3)3, Al(C6H5SO3)3, Al(CH3C6H4SO3)3 and Al(C12H25C6H4SO3)， and aluminum salt-[DMIM]HSO4 were tested as the catalysts to conversion corn starch to methyl levulinate in the methanol. Reaction parameters temperature, reaction time, catalyst amount, ionic liquid amount, and methanol amount were optimized with regarding to methyl levulinate yield. The investigation shows that 1,3-dimethylimidazolium hydrogen sulfate has significant improvement effect on the catalytic activities of Al(CH3SO3)3 and Al(C6H5SO3)3 catalysts. They can significantly improve the yield of methyl levulinate. A yield of 57.1% could be obtained at 150℃ within 3h of reaction when the ratio of corn:Al (CH3SO3)3:[DMIM]HSO4:methanol equal to 0.8:0.7:0.3:6. Methyl levulinate yield of 58.0% could be obtained at 170℃ within 3h of reaction at the ratio of corn:Al(C6H5SO3)3:[DMIM]HSO4:methanol= 0.8:0.5: 0.3:7. When Al(CH3C6H5SO3)3 only was used, the highest yield of methyl levulinate was 53.1%.更多还原