【作者】 周丽亚；

【导师】 高静；

【作者基本信息】 河北工业大学 ， 化学工艺， 2003， 硕士

【摘要】 本文介绍了一种合成乳酸乙酯的新工艺，即采用催化精馏技术，以乳酸和乙醇为原料、以强酸性离子交换树脂为催化剂催化合成乳酸乙酯，将催化精馏技术应用于乳酸乙酯的合成是一项新的尝试，它的研究对于促进我国乳酸乙酯工业的发展具有重要的意义。 本文探讨了用强酸性离子交换树脂为催化剂合成乳酸乙酯的反应动力学。通过对实验结果的分析，得出如下结论：酯化反应为二级反应，水解反应为零级反应，其反应动力学模型为：其中，且发现在温度较低时这一反应存在诱导期问题。 本文在自行设计安装的高度为1100mm、直径为40mm的催化精馏塔内，用θ网环填料装填催化剂NKC-9构成反应段，考察了回流比、进料位置、进料流量、醇酸比等参数对催化精馏过程的影响，得到了最佳反应条件：回流比为1:1、进料位置为反应段顶部进酸反应段底部进醇、乳酸进料流量为0.6482mol/h、醇酸比为4:1。 在实验结果的基础上，以动力学模型为基础，借助ASPEN软件用平衡级模型进行了催化精馏塔的模拟，塔内温度分布和塔釜、塔顶组成的模拟结果与实验测定结果吻合较好，表明模拟结果是可靠的。对于催化精馏过程合成乳酸乙酯的工业化生产具有一定的指导意义。 研究结果表明，催化精馏技术应用于乳酸乙酯的合成可以提高产品的收率，反应过程对环境无污染，对设备无腐蚀，产品乳酸乙酯又是一种“绿色溶剂”，因此该技术是一项绿色技术，有很好的工业前景。更多还原

【Abstract】 A new technique is introduced for the synthesis of ethyl lactate. Namely, under ion-exchange resin catalyst a process of catalytic distillation is applied in synthesis of ethyl lactate with lactic acid and ethanol. It is a new try for synthesis of ethyl lactate through catalytic distillation and is very important for the development of ethyl lactate industries if it will be a successful study.We selected ion-exchange resin as the catalyst of this experiment. Reactive kinetics using ion-exchange resin catalyst is experimentally determined, and the equation of the reaction rate is established. The conclusion is obtained by analyzing the experiment result: the esterification is second-order reaction, and the hydrolysis is zero-order reaction, so the model for reactive kinetics is obtained:where k+ = 0.06429<T265161IRT and k. = 840.3345<T43182 9/;r/’ .The problem of inducement period is also found when the temperature is lower.Catalytic distillation integrates the reaction and distillation into one reactor and realizes ethyl lactate produced continuously. Catalytic distillation experiments for synthesis of ethyl lactate are carried out in a 1100 mm high and 40mm diameter column filled with the novel catalyst bed-NKC-9 sandwiched between 9 sheets with wire gauze. The effect of reflux ratio, feed location, feed flow rate and the ratio of ethanol to lactate in feeds is investigated. By analyzing the experimental data, the optimum conditions are obtained. That is, the reflux ratio is 1:1, feed locations are lactic acid fed at the top and ethanol at the bottom of the reactive region, lactic acid feed flow rate is 0.6482mol/h, the feed ratio of ethanol to lactic acid is 4:1.Based on the experiment and the reaction rate equation, ASPEN software is chosen to simulate the temperature, concentration and other profiles of the catalytic distillation column by equilibrium-staged model. The results of the temperature profile along the column height and components of the tower top and bottom are in agree with the experimental data, and are satisfactory. So it provides the basic guideline to industrial production of ethyl lactate usedcatalytic distillation.The study results indicate the catalytic distillation process, in which realistic conversion and higher purity product are obtained, is applied for synthesis of ethyl lactate. The process is little pollution on the environment and little erosion on the equipment, and ethyl lactate is a "green" solvent, so the technology is a "green" technique and will have good prospective applications in the future.更多还原