Technology Profile: Vinyl Acetate from Acetic Acid and Ethylene
By Intratec Solutions |
This column is based on “Vinyl Acetate from Acetic Acid and Ethylene — Cost Analysis,” a report published by Intratec. It can be found at: www.intratec.us/analysis/vinyl-acetate-production-cost.
Vinyl acetate (vinyl acetate monomer; VAM) is an important vinyl ester, primarily used in the production of polymers and copolymers for coatings, paints and sealants, as well as for binders and in textile and paper processing.
The following paragraphs describe a typical vapor-phase oxidation process for VAM production from acetic acid and ethylene. Figure 1 presents a simplified flow diagram of the process.
Figure 1. This diagram shows a typical vapor-phase oxidation process for vinyl acetate production[/caption]
Reaction. Make-up and recycled acetic acid pass through a vaporizer, along with fresh and recycled ethylene. The feed stream, containing excess of ethylene over acetic acid, is mixed with oxygen, preheated and fed to multi-tube reactors. The reaction occurs over palladium and gold catalysts. Heat is removed by evaporative cooling on the reactors’ shell. At the end of this stage, 8–10 wt.% of ethylene and 15–35 wt.% of acetic acid are converted to VAM. Water, CO2 and small quantities of ethyl acetate, ethylidene…