Recovery of PVA by-product methyl acetate via reactive and extractive distillation

• A RED process was proposed to recover MA from the PVA production process.
• The effects of heat loss in RED column under different RR were investigated.
• The effects of several operation parameters for this system were investigated.

A packed-bed reactive and extractive distillation column was proposed to recover polyvinyl alcohol by-product methyl acetate. The azeotrope of methyl acetate and methanol from a polyvinyl alcohol plant was used as experimental material. In the reactive and extractive distillation column, methanol was transformed to methyl acetate over a cation-exchange resin. The simulation for this process was carried out by means of the RADFRAC equilibrium stage model in Aspen Plus. The equilibrium-stage model can describe the reactive and extractive distillation column, but heat loss of the laboratory-scale distillation column should be taken into account in the simulation at a low reflux ratio. The effects of several operation parameters, such as the stage number of reaction section, and stage number of non-reaction section, the reflux ratio, the volume ratio of the extractive solvent to the feed mixture, and the feed location on the performance of the reactive and extractive distillation column were investigated. According to the simulation results, a novel process for methyl acetate recovery was developed, and the methyl acetate purity in the distillate and the methanol conversion can reach higher than 99% and 94%, respectively.