A novel integration of reaction distillation and pervaporation membrane for producing n-propyl propionate

N-propyl propionate (N-ProPro), which is an essential chemical, can be produced via the esterification of n-propanol (ProOH) with propionic acid (ProAc). Aiming at improving the economic efficiency and saving the energy consumption of the esterification process, an intensified model hybridizing side-reactor column with pervaporation membrane (SRC-PV) configuration is proposed in this work. Mixture is drawn from the reaction distillation (RD) column after ProAc and ProOH are esterified in a side reactor, and then, a pervaporation membrane is assigned to remove water for producing high-purity N-ProPro products. The minimum total annual cost (TAC), an important parameter for evaluation of the economic efficiency, was obtained by the particle swarm optimization (PSO) algorithm. Results shows that the SRC-PV process could achieve 18.3% energy savings compared to the side-reactor column (SRC). Moreover, the value of CO2 emission was calculated, and that of the SRC-PV process was reduced by 6.7% compared with the SRC process. All of the results illustrate that the SRC-PV process presents significant economic and environmental advantages. Meanwhile, dual composition/temperature-proportional feed-forward control structure is designed to achieve high stability of the SRC-PV process.