Semicontinuous Separation of Bio-Dimethyl Ether from a Vapor–Liquid Mixture

In this work, a semicontinuous system is investigated for the separation of biomass-derived dimethyl ether from a vapor–liquid mixture. This novel semicontinuous system operates in a cyclic campaign and utilizes one partial condenser column coupled with a middle vessel to achieve the separation typically carried out using two continuous distillation columns. The performance of six control configurations based on composition or temperature inferential control were analyzed. Dynamic simulation results demonstrate the effectiveness of the semicontinuous system and its temperature inferential control configuration in achieving the separation objectives, remaining within operational limits and rejecting fresh feed disturbances. Finally, the semicontinuous system is compared to the traditional continuous system from an economic standpoint with the sensitivity of operating cost to middle vessel product target purity highlighted.