Abstract:

Oxime exchange is a novel process preparing acetaldehyde oxime, but some disadvantages in the reaction process also exist, such as easily oxidized acetaldoxime by air, many azeotropes in the reaction solution, and hardly separated and purified acetaldoxime.The oxidation of acetaldehyde oxime and volatilization of acetaldehyde and butanone oxime were avoided using 0.2 MPa nitrogen as protective gas during the reaction process. The selectivity of acetaldehyde oxime is 96.12%. Moreover, an effective purification process of the product was developed. Firstly, the basic process of separation of reaction liquid by vacuum distillation was simulated by Aspen plus. The influences of pressure, plate number, reflux ratio and feed position on the separation process were investigated. According to the operating parameters of simulation, the optimum separation and purification process in actual reaction were determined. In this condition, the purity of the resulting acetaldoxime is 95.33% with the yield of 94.31%. This work could provide guidance for the industrialization of acetaldehyde oxime by oxime exchange method.

Key words: Acetaldehyde oxime, Oxime exchange method, Nitrogen, Aspen Plus simulation, Vacuum distillation

摘要：

肟交换法是一种制备乙醛肟的新兴工艺，但反应过程存在乙醛肟易被空气氧化等问题，且反应液中存在多组共沸物，分离提纯得到高纯度的乙醛肟较为困难。以丁酮肟为原料，通过向反应器内充入0.2 MPa的氮气，有效避免了乙醛肟氧化与原料乙醛、丁酮肟的挥发，乙醛肟反应选择性达96.12%。开发了产物的提纯工艺，通过Aspen Plus模拟,初步确定减压精馏分离反应液的基本流程，考察了压力、塔板数、回流比、进料位置等操作参数对分离过程的影响。在此基础上，依据模拟确定的操作参数进行实验，确定最优分离提纯工艺，得到纯度为95.33%的乙醛肟产品，收率可达94.31%。本研究可为肟交换法制备乙醛肟的工业化提供一定的指导。

关键词: 乙醛肟, 肟交换法, 氮气, Aspen Plus模拟, 减压精馏