Acetic Acid
Acetic acid feeds into a variety of derivatives and is thus influenced by many downstream markets. In addition, acetic acid is generated as a coproduct in some processes, which influences acetic acid supply/demand as well. The recovered acid is often recycled and reused within the same facility, but can also be purified and sold on the merchant market. This makes the determination of exact acetic acid consumption levels by derivatives difficult to discern. The picture is further complicated because the recovered acetyl group might be recovered as acetic acid, but could also be recovered as an acetate ester. For example, polyvinyl alcohol is produced from polyvinyl acetate, which is made from vinyl acetate monomer (VAM). If the polyvinyl acetate is hydrolyzed (with water), acetic acid is recovered. If the polyvinyl acetate is reacted with methanol or ethanol, then methyl acetate or ethyl acetate, respectively, are recovered along with the polyvinyl alcohol.
The largest end-use for acetic acid is the production of Vinyl Acetate Monomer (VAM). VAM in turn is primarily converted to polyvinyl acetate, some of which is used directly as the homopolymer or in various copolymers, or further converted into polyvinyl alcohol (PVOH), which results in recovered acetic acid.