Considering the unreacted reactant p-xylene and by-product methyl acetate as feed impurities in the industrial acetic acid dehydration process using n-propyl acetate as entrainer

HOC and UNIQUAC models were chosen respectively to compute the strong nonideality of vapor and liquid phase of the quinary system.The binary parameters in the UNIQUAC model of methyl acetate-p-xylene and n-propyl acetate-p-xylene systems were obtained by regressing the phase equilibrium data from experiment.Combining with binary parameters of the other binary systems built-in simulation software

the mechanism model of heterogeneous azeotropic distillation was developed and the simulation of the industrial HAc dehydration process including dehydration column

PX pure column and entrainer recovered column was conducted with Aspen Plus.The simulation results of key parameters agree well with the process data with the errors within ?6%.Thus

the model can describe the HAc dehydration process accurately

and it lays a solid foundation for the further study of industrial acetic acid dehydration process.