Reactive Distillation-Pervaporation Hybrid Process for the Production of Ethyl Acetate & Isopropyl Acetate

This study raises a pervaporation (PV) – reactive distillation (RD) hybrid configuration for producing high purity ethyl and isopropyl acetate product. impure acetic acid and alcohol are the reactants to the system. From the residue curve map of these two systems, it was found that the overhead products of the RD column are the alcohol-water-acetate ternary azeotrope which are inside the liquid-liquid boundary. By implementing an overhead decanter, the water generated from the esterification can be removed effectively. Via the total reflux of the organic phase, a side stream with extremely high acetate purity can be drawn from the rectifying section of the RD column. Finally, pervaporation units are applied to remove water for producing high specification product. The total annual cost (TAC) analysis is used to determine the optimal design configuration. Compare to the traditional two column processes[1], the hybrid process for ethyl and isopropyl acetate can save about 13% and 20% reboiler duty respectively. Based on the optimized hybrid process, two different control strategies – the single-point temperature control and the dual-point temperature control – are proposed to examine the performance of rejecting main disturbances to the process. A lot of simulation tests show that the single-point temperature control structure fails to maintain adequate product specification should the acid purity in feed is lower than a specific value. However, the dual-point temperature control structure can handle both throughput and feed composition disturbances quite well.