Study On The Kinetics Of Synthesis Of Isobutyl Acetate By Transesterification And Simulation Of Reactive Distillation

Isobutyl acetate is an organic solvent widely used in the chemical industry,and it is also a raw material for perfumes,coatings,inks,adhesives,detergents and degreasing agents.As a by-product in the industrial production process of polyvinyl alcohol,methyl acetate is often treated by hydrolysis,which consumes a lot of energy.Therefore,the use of methyl acetate and isobutanol transesterification to produce isobutyl acetate is a way worth trying.In this paper,methyl acetate and isobutanol are used as raw materials for the transesterification reaction.The cation exchange resin NKC-9 is used as the catalyst.The reaction conditions are optimized,the thermodynamic parameters of the reaction are calculated,and the kinetics of the reaction process of methyl acetate and isobutanol is simulated.On this basis,the reactive distillation process is designed and simulated.The progress made in this research is as follows:1.Study on the synthesis of isobutyl acetate catalyzed by cation exchange resinIn the intensified fixed bed reactor,the cation exchange resin NKC-9 is used to catalyze the transesterification reaction of methyl acetate and isobutanol.The optimized process conditions are: the liquid circulation flow rate is set to 2.4 L·h^-1,the catalyst loading is 15 wt%,the initial molar ratio of methyl acetate to isobutanol is 2:1and the reaction temperature is 323.15 K.After using the UNIFAC group contribution method to modified the non-ideality of the solution,the expression of the reaction equilibrium constant with the reaction temperature can be expressed as follows:The Pseudo-homogeneous kinetic model is used to study the kinetics of the reaction between methyl acetate and isobutanol catalyzed by the NKC-9 cation exchange resin in IFBR.Under the experimental conditions,the kinetic equation can be expressed as:Where2.Simulation of Reactive Distillation Process in Transesterification Synthesis of Isobutyl AcetateUsing the thermodynamic and kinetic parameters obtained from the kinetic experiment,the rectification process of the transesterification reaction is designed and simulated by the Rad Frac module in Aspen Plus software.The entire reactive distillation process includes a reactive distillation column,a high pressure column and an atmospheric column.The result of optimizing the operating parameters is: the number of theoretical plates in the rectification section of the reactive distillation column is 6,the number of theoretical plates in the stripping section is 3,the number of theoretical plates in the reaction section is 35,isobutanol and methyl acetate The feed ratio is 1:1.5,feed from the seventh and the forty-first plates respectively,and the reflux ratio is selected as 1.The number of theoretical plates in the atmospheric column is 14,and the material is fed from the fifth plate,and the reflux ratio is 4.The number of theoretical plates of the high-pressure column is 17,and the material is fed from the fifth plate,and the reflux ratio is 1.5.The conversion rate of isobutanol in the reactive distillation column and the purity of isobutanol acetate at the bottom of the column both exceed 99.5%.The mole fraction of methyl acetate in the bottom distillate of the high pressure column and the mole fraction of methanol in the bottom distillate of the atmospheric column are both close to 100%.