【作者】 李杰；

【导师】 黄耀东； 于春杰；

【作者基本信息】 天津大学 ， 制药工程， 2008， 硕士

【摘要】 固体酸催化剂是石油化工和有机合成工业中比较有前途的催化剂之一,本文研究了以2-酮基-L-龙酸、甲醇为原料,以沉淀浸渍法制备的SO₄^2-/Fe₂O₃为催化剂,催化合成2-酮基-L-古龙酸甲酯的酯化反应体系。根据对SO₄^2-/Fe₂O₃和SO₄^2-/ZrO2两种固体酸催化剂催化活性和寿命的研究对比,筛选出较为理想的SO₄^2-/Fe₂O₃作为催化剂。在实验中,研究了影响2-酮基-L-古龙酸甲酯化反应的主要操作条件:催化剂用量、反应温度、反应时间、醇酸的摩尔比对酯化反应的影响,并利用正交实验设计法筛选出最佳的酯化反应工艺条件,即催化剂用量为2～3%,反应温度在66～68℃,反应时间为2.5～3h,甲醇与2-酮基-L-古龙酸的摩尔比为19～20。结果表明,采用酯化新工艺进行维生素C中间体维生素C钠的合成,2-酮基-L-古龙酸与甲醇反应的酯化率可达到93.87%以上,比原工艺提高了2.37%,维生素C钠干品质量明显提高,含量达到了91.5%,提高了2%。同时,考察了通过过滤方法回收催化剂的情况。研究结果表明,SO₄^2-/Fe₂O₃作为维生素C生产中2-酮基-L-古龙酸与甲醇的酯化反应的催化剂所确定的新工艺与原工艺相比,无论从酯化反应的收率及中间体的质量方面都有明显提高。而SO₄^2-/Fe₂O₃作为反应的催化剂具有易分离、无污染、无腐蚀性,克服了浓硫酸的缺点,是一种极具潜力的新型绿色环保催化剂。更多还原

【Abstract】 Solid acid catalyst is the petrochemical and industrial organic synthesis in the future more of a catalyst, In this paper, a 2-Keto-L-Lung acid, methanol as raw materials and precipitation prepared by soaking the SO₄^2-/Fe₂O₃ as a catalyst, Synthesis of 2-Keto-L-Gulong methyl esterification system.According to SO₄^2-/Fe₂O₃ and SO₄^2-/ZrO2 two solid acid catalyst activity and life of contrast, Screening to a more satisfactory SO₄^2-/Fe₂O₃ as a catalyst. In the experiment to study the impact of 2-Keto-L-Gulong reaction of methyl the main operating conditions: The amount of catalyst, temperature, reaction time, the ratio of alkyd esterification of the impact and use of orthogonal experimental design selected the best esterification process, That is, the amount of catalyst for 2 to 3 percent, the reaction temperature in the 66 68℃, the reaction time is 2.5 3 h, methanol and 2-Keto-L-Gulong acid ratio of 19 to 20. The results showed that the use of new technology esterification intermediate vitamin C synthesis of vitamin C sodium, 2-L-gulonic acid and methanol reaction yield up to 93.87 percent more than the original process than the 2.37 percent increase, Vitamin C sodium dry goods significantly improve the quality, content reached 91.5 percent, increased by 2%. At the same time, inspected the catalyst for recovery through the filter approach the situation.The results show that SO₄^2-/Fe₂O₃ as the production of vitamin C 2-L-gulonic acid and methanol catalyst identified by the new technology compared with the original process, Whether from the yield and the quality of both intermediate increased significantly. The reaction SO₄^2-/Fe₂O₃ as a catalyst for easy separation and pollution-free, non-corrosive, has overcome the shortcomings of concentrated sulphuric acid, is a great potential of the new green catalyst.更多还原