Design and simulation of an entrainer-enhanced ethyl acetate reactive distillation process

This paper presents an approach to intensify a reactive distillation (RD) process for ethyl acetate (EtAc) production using a mass separation agent (entrainer), and a new process flowsheet with a sidedraw to the RD column. The heterogeneous azeotrope formed by water and EtAc contains less water than that is produced by the esterification reaction. N-butyl acetate is selected as an appropriate entrainer to withdraw the accumulated H2O from the RD column rectifying section. The equilibrium stage model based on the RADFRAC module of Aspen Plus is employed for the steady-state simulation of the improved process flowsheet. The stage number of the rectifying section and reactive section, sidedraw location and flowrate, sidedraw aqueous phase reflux flowrate, and overhead organic reflux flowrate are investigated to determine an optimal flowsheet design. The entrainer-enhanced EtAc RD process efficiently uses the raw materials and significantly increases the process efficiency, allowing significant energy savings. Remarkably, compared to previously reported RD processes, the energy consumption of this novel process is about 32% lower while the capital investment almost remains the same.

► A novel process flowsheet of a RD column with a sidedraw is presented in the presence of n-butyl acetate employed as a mass separation agent to intensify the EtAc production for better energy efficiency.
► A thermodynamic model of NRTL-HOC is screened to predict the behavior of the proposed quinary system.
► A simulation model is established in Aspen Plus environment to optimize the presented flowsheet.
► The improved process decreases the overall energy requirements by about 32%.