制取无水叔丁醇的精馏工艺优化和对比

Optimization and comparison of different distillation schemes for anhydrous tert-butanol production

无水叔丁醇是一种重要的化工原料,然而在工业生产过程中会与水形成最低共沸物,难以通过简单精馏的方式获得。基于此,本文提出双塔萃取精馏、隔壁塔萃取精馏和反应精馏三种精馏工艺来制取高纯度叔丁醇。在双塔和隔壁塔萃取精馏的优化中,利用Aspen Plus软件模拟该分离过程,以年度总费用(TAC)为目标进行过程优化,得到最佳操作参数。在反应精馏塔中,采用环氧乙烷多股进料的方式,环氧乙烷可与水反应并打破叔丁醇/水的共沸平衡最终制得无水叔丁醇。鉴于反应精馏塔的复杂性,对于反应精馏塔的操作参数进行详细的灵敏度分析以确定反应精馏塔在叔丁醇除水的可行性和潜力。模拟结果表明,与双塔萃取精馏相比,隔壁塔萃取精馏虽然能降低能耗但是也会增加6.51%的TAC,因此隔壁塔萃取精馏并不具有经济性;而反应精馏塔则能降低47.69%的能耗和35.36%的TAC,显现出巨大的应用潜力。

Anhydrous tert-butanol(TBA)is an important chemical raw material.However,it can form a minimum azeotrope with water in industrial production,making it difficult to produce anhydrous TBA by simple distillation.In this article,the separation schemes for TBA dehydration of conventional twocolumn extractive distillation column(CEDC),extractive dividing-wall column(EDWC)and reactive distillation column(RDC)were proposed.In the design of CEDC and EDWC,the process was simulated via Aspen Plus software,and it was optimized with the total annual cost(TAC)as the target function to obtain the optimal operating conditions.In the RDC,multiple feeds of ethylene oxide(EO)were fed into the column,which could react with water and overcome the azeotropic equilibrium of TBA/water to obtain anhydrous TBA.Due to the complexity of RDC,the detailed sensitivity analysis of RDC was conducted to investigate the feasibility and potential of RDC in TBA dehydration.The computational results showed that the EDWC,compared with the CEDC,can reduce the energy consumption while increased 6.51%of TAC due to the requirement of more expensive utilities.Therefore,the EDWC was not economically superior to CEDC.Conversely,the RDC exhibited great application potential for TBA purification since it could reduce 47.69%of energy requirement and 35.36%of TAC.