Adapting Vinyl Acetate Monomer Plant for Manufacturing Allyl Acetate and Allyl Alcohol

An economically optimal process configuration was developed for manufacturing of Allyl acetate and Allyl alcohol by adapting Vinyl Acetate Monomer plant. Vinyl acetate monomer is manufactured by Acetoxylation of Ethylene in vapor phase reaction while Allyl acetate is manufactured by Acetoxylation of propylene. Water is formed as by-product in the reaction. Hydrolysis of Allyl acetate produces Allyl alcohol and acetic acid is formed as by-product. Allyl acetate, Allyl alcohol and light end impurities form several binary and ternary low boiling homogeneous and heterogeneous azeotropes with water, which makes purification of Ally acetate and Allyl alcohol a complex process.

A rigorous simulation model was built in Aspen Plus for Allyl acetate manufacturing by adapting process configuration of Vinyl Acetate Monomer plant. Suitable process modification were done in Feed system, Acetoxylation reactor effluent section, Recycle gas section and Purification section considering the difference in feedstock and water content in azeotrope of Allyl acetate-Water. Different process configurations were evaluated for purification of Allyl acetate by azeotropic distillation, to minimize the energy consumption and maximize product recovery.

For Allyl alcohol purification, various different processes were evaluated using advanced process simulation and azeotropic distillation route was found to be the most suitable one. The energy consumption was observed to be sensitive to water content in reaction product and at high water conent, the manufacturing of Allyl alcohol becomes economically non-viable. The trade-off between hydrolysis conversion with different molar ratio of Water to Allyl acetate and the operating cost of purification provided insights for optimizing reaction parameters and determining optimal process configuration for purification.

This paper describes process development approach using advanced process simulation, combined with process knowledge, to determine economically optimum and energy efficient process configuration for manufacturing.