Synthesis of vinyl acetate monomer from synthesis gas

Previous attempts to synthesize vinyl acetate monomer (VAM) from synthesis gas involve routes that require a costly recycle of acetic acid through a c arbonylation reactor. Two new routes to VAM from synthesis gas that avoid t his acetic acid recycle have been investigated. One of these new routes syn thesizes VAM from acetic acid via the intermediacy of ketene. Ketene is hyd rogenated to acetaldehyde, and the acetaldehyde is reacted directly with ke tene to produce VAM. The second route synthesizes VAM from the carbonylatio n of dimethyl ether to acetic anhydride followed by reaction of the acetic anhydride with acetaldehyde in a reactive distillation column to produce VA M and acetic acid. The co-produced acetic acid is hydrogenated to form the acetaldehyde required in the reactive distillation. (C) 2000 Elsevier Scien ce B.V. All rights reserved.