【作者】 周翠芳；

【导师】 何杰；

【作者基本信息】 天津大学 ， 化学工程， 2008， 硕士

【摘要】 醋酸甲酯(MeOAc)作为一种化工原料,其主要用途是作为硝基纤维素和醋酸纤维素的快干性溶剂;还可以作为油漆涂料、人造革和香料制造的原料以及用作油脂的萃取剂等,但与同族其它酯类相比,其需求量不是很大。它在工业生产中,往往作为副产品大量出现,如聚乙烯醇(PVA)生产过程中有大量的副产物醋酸甲酯,据估计,每生产一吨PVA将副产1.5～1.7吨的醋酸甲酯。目前,PVA生产厂家均采用将其水解生成醋酸和甲醇的方法加以利用,因醋酸和甲醇可用作生产PVA的原料。醋酸正丁酯为无色透明液体,是重要的有机溶剂、萃取剂和脱水剂,在工业上用途广泛。本文采用酯交换法将醋酸甲酯转化为醋酸丁酯,可以为醋酸甲酯提供一种效益更高的利用方法。本论文对反应动力学进行实验研究,计算出活化能及指前因子,为后续的精馏实验及模拟提供依据。通过催化精馏实验,改变操作条件,考察进料方式、进料组成、回流比及进料总量等操作条件的变化对醋酸甲酯转化率的影响,并根据结果选择最优的操作条件。在实验范围内,催化精馏过程适宜的操作条件为:回流比10;进料醇酯摩尔比3:1;进料总量22mol/h;进料采用重组分正丁醇在反应段上部进料,轻组分醋酸甲酯在反应段下部进料。借助ASPEN PLUS软件对反应精馏制醋酸正丁酯的过程进行模拟计算,将模拟值与实验值进行对比,从而验证计算的可靠性。进一步模拟优化,以模拟计算结果为依据,为后续的实验研究提供指导依据。结果显示,该模拟结果与实验值的相对误差最大不超过8%,在可接受范围内,故认为模拟值是可靠的。分别改变正丁醇和醋酸甲酯的进料位置,结果表明,反应段的长度越大转化率越高。增加反应段的理论塔板数,在实际实验中则表现为反应段与填料段交叉排列,能提高醋酸甲酯的转化率。更多还原

【Abstract】 As a chemical raw material methyl acetate (MeOAc) mainly is used as a fast-drying solvent of nitro-cellulose and cellulose acetate; it can also be raw materials for paint, leather and spices, and for oil extraction etc., but comparing with other esters in the same race, its demand is not great. In industrial production, it is often used as a by-product, such as in process of polyvinyl alcohol (PVA) with a large number of by-products of methyl acetate. It is estimated that it will produce 1.5 to 1.7 tons of MeOAc for each ton product of PVA. At present, PVA manufacturers are used to hydrolyze methyl acetate, because acetic acid and methanol can be used for the production of PVA as raw materials. N-butyl acetate is a colorless, transparent liquid, which is important organic solvent, extractant and dehydrating agent, widely used in industry. In this paper, methyl acetate will be converted into n-butyl acetate by transesterification, which can provide a more efficient use of methyl acetate.In this paper, reaction kinetics was experimentally studied and pre exponential factor and the activation energy were calculated for follow-up experimental research and simulation. Then, catalytic distillation experiment was done while changing operating conditions to inspect the influence of feed mode, feed composition, reflux ratio and total feed flow on conversion of methyl acetate. According to the results the best operating conditions have been chosen. Best operating conditions for catalytic distillation process are as follows: reflux ratio 10; mole ratio of alcohol and ester 3:1; total feed flow 22mol/h; n-butanol feed at the upper part, methyl acetate feed at the lower part.Process simulation data done by Aspen Plus was compared with experimental data. The error being within an acceptable bound, the results of process simulation are credible. After the simulation process further optimized, the results can provide guidance for following experimental study. The results revealed that the error between the simulation and experiment was less than 8% within an acceptable range, so the simulation is reliable. By respectively changing the feed position of n-butanol and methyl acetate, results showed that the greater the length of reaction part was, the higher the conversion rate would be. Increasing the theory plate number of reaction part by adding certain height of packing in actual experiment can increase the conversion rate of methyl acetate.更多还原