侧反应器反应精馏方法生产醋酸甲酯的模拟

采用强酸性阳离子交换树脂催化醋酸与甲醇反应精馏生成醋酸甲酯,可避免硫酸作为催化剂的不足。但该非均相催化反应受平衡限制,且达到平衡时间较长,采用传统反应精馏塔难以提供足够反应空间。文中设计侧反应器与精馏塔耦合新工艺,采用Aspen Plus软件模拟研究了侧反应器数量、位置,原料进料位置,回流比,醇酸比等对反应精馏过程的影响。结果表明,当装置具有7个侧反应器,反应器间隔4块板,在优化的操作条件下,醋酸甲酯质量分数可达99.1%。

Simulation of methyl acetate synthesis in distillation column with external side reactors

The strong acidic ion exchange resin is used as catalyst to produce high purity methyl acetate from acetic acid and methanol by reactive distillation process,which can avoid the disadvantages when sulfuric acid is taken as catalyst.But heterogeneous reactive distillation is still limited for high purity methyl acetate synthesized by acetic acid esterification,mainly because the high liquid holdup in the reactive section for maximizing reactive retain time does not match the requirement of high interfacial area for good separation.This mismatch problem can be overcome by considering an alternative process flowsheet that features a distillation column with external side reactors.A distillation column with side reactors model was established in Aspen Plus,then the influence of device parameters and operation conditions such as numbers of side reactors,feeding location,reflux ratio and ratio of alcohol to acid on the reactive distillation was discussed.The results show that the mass fraction of methyl acetate achieves 99.1% under the optimal operation conditions in a column with 7 side reactors and 4 trays between two rectors.