共沸-反应精馏隔壁塔制备乙酸乙酯的实验与模拟研究

Experiment and simulation study of azeotropic-reactive distillation dividing wall column for production of ethyl acetate

针对反应精馏中部分物系存在反应物与生成物相对挥发度较小、难以分离的问题,提出共沸-反应精馏隔壁塔结构。以酯化法制备乙酸乙酯为研究对象,对共沸-反应精馏隔壁塔的操作性能进行了分析。在搭建的1套反应精馏隔壁塔实验装置内进行了相应的实验研究,并用Aspen Plus进行了模拟,模拟结果与实验结果一致性良好;对共沸剂用量、液相分配比、塔顶回流比以及原料乙酸质量分数等因素的影响进行了模拟研究;对共沸-反应精馏隔壁塔进行了节能分析。与传统反应精馏相比,共沸-反应精馏隔壁塔可实现重组分乙酸和中间组分水的清晰分离,有效避免中间组分的返混,提高热力学效率。

The relative volatility between the reactant and the product is close to 1 for some mixtures,so they are hard to separate clearly by reactive distillation. The azeotropic-reactive distillation dividing wall column structure is proposed to solve such difficulties. Taking the synthesis of ethyl acetate with the esterifying method as study object,the operational performance of azeotropic-reactive dividing wall column is analyzed. An azeotropic-reactive dividing wall column experimental equipment is built up.The synthesis of ethyl acetate is studied through experiment in this equipment and also simulated by Aspen Plus.The results of simulation agree with the experiment ones very well. The influences of the amount of azeotropic agent,liquid phase split ratio,reflux ratio and the concentration of acetic acid in feedstock are simulated by Aspen Plus. The energy saving analysis is carried out for the azeotropic-reactive distillation dividing wall column.Compared with the traditional reactive distillation,the azeotropic-reactive dividing wall column can achieve clear separation between the heavy component acetic acid and intermediate component water,avoid the back-mixing of the intermediate components effectively,and improve thermodynamic efficiency.