Controllability of separate heat pump distillation for separating isopropanol-chlorobenzene mixture

The isopropanol-chlorobenzene mixture is separated via separate heat pump distillation (SHPD) to achieve significant energy savings. Rigorous steady state and dynamic characteristics for this SHPD process are simulated using Aspen Plus and Aspen Plus Dynamics. Optimized operation conditions including vapor flow rate to compressor are developed on the condition of minimum total annual cost. Two control strategies are proposed to solve feed disturbance issues and the improved structure with Q Re /F (lower column reboiler duty/feed flow rate) ratio scheme can maintain the two product purities requirement with smaller transient deviation and shorter settling time.