Simulation study on a reactive distillation process of methyl acetate hydrolysis intensified by reaction of methanol dehydration

Methyl acetate (MeOAc) recovery from the polyvinyl alcohol (PVA) production is a difficult and heavy energy consuming process. In this work, a reactive distillation (RD) process of MeOAc hydrolysis intensified by methanol (MeOH) dehydration, as an auxiliary reaction, was proposed. Two different feeds with the mole ratio of MeOAc to MeOH at 1:1 and 1:9 were studied, and the effect of the operating pressure, the feed location and the reflux ratio on the RD column was analyzed. The simulations of reactive distillation were performed using a three phase non-equilibrium model implemented by gPROMS. As the limit of the reaction rate of MeOH dehydration, it is impossible to get 100% conversion of MeOAc and MeOH by a single RD column. Therefore, two novel processes for recovery of methyl acetate in PVA production were developed. The simulation results show that the high purity of dimethyl ether (DME) could be achieved with a complete conversion of MeOAc, and a large amount of energy demand and equipment costs can be reduced.

► We introduce methanol dehydration as auxiliary reaction to intensify methyl acetate hydrolysis. ► Two novel processes of recovery of PVA effluent were designed by introduction of methanol dehydration. ► No additional H2O was needed as feed of reactive distillation column while high methyl acetate conversion could be achieved. ► The simulation results show that a large amount of energy consumptions and cost of equipments could be saved. ► High purity of DME could be produced in the process of recovery of PVA effluent.