Application Of Response Surface Methodology In The Production Of Isopropanol By Pressure Swing Reaction Rectification

Isopropanol is an excellent organic raw material and industrial solvent in the chemical industry.Mainly,it is used as pharmaceutical intermediates,an intermediate in chemical synthesis,or as an important solvent in the ink,cosmetics,and coatings industries.Conventionally,there are two commercial routes to produce isopropanol:direct hydration and indirect hydration of propylene.However,it mainly suffers from the complexity of the process,a low selectivity,high energy requirement,and serious corrosion to equipment because of the use of sulfuric acid as catalyst.Also,the separation of IPA from the azeotropic mixture is technically difficult and expensive.Therefore,in this paper,a reactive distillation process is used to produce isopropanol by transesterification of isopropyl acetate with methanol using sodium methoxide solution as catalyst,which is a simpler and less expensive alternative to the conventional processes.In this paper,the Aspen plus simulation software was used to steady-state simulate the conventional reactive distillation process and the pressure-swing reactive distillation process for the production of isopropanol by transesterification process.Based on the results of the sensitivity analysis of the pressure-swing reactive distillation process,the reaction distillation column RD operation pressure(P1),purification and recovery column RC operation pressure(P2),isopropyl acetate feed stage(NF),RD tower reflux ratio(R1),RC tower reflux ratio(R2)and reaction distillation column RD total theoretical stage number(NT),etc.6 key operation parameters of the pressure swing reactive distillation process were optimized by the CCD response surface optimization method.Combined with the actual production process,the combination of the optimal operating parameters after the round setting P1=0.734atm,P2 =4.244 atm,NF=11,R,=3.758,R2=2.923,NT =26 were obtained.Through the establishment of the model,the quadratic regression equations were respectively obtained for the mole purity of isopropanol in the RC column bottom and the total energy consumption of the twin columns.Compared the pressure-swing reactive distillation process optimizedby response surface methodology with the conventional reactive distillation method,the reactive distillation method without the response surface method and the reactive dividing-wall-column in literature were simulated in the Aspen Plus results and column equipment parameters,respectively.The results showed that the pressure-swing reactive distillation process optimized by response surface methodology could get higher purity isopropanol product while consuming the same raw materials,and the total energy consumption was significantly reduced.Therefore,the optimization of pressure-swing reactive distillation for isopropanol production by response surface methodology has obvious advantages in improving product purity and reducing process energy consumption,and has great industrial application value.