IMPROVED PROCESS FOR RECOVERING HYDROGEN IN PRODUCING PURE TEREPHTHALIC ACID

摘要

A method for recovering and recycling excess hydrogen from process vent streams in the production of highly pure terephthalic acid where the production of the pure terephthalic acid comprises catalytically hydrogenating impure terephthalic acid, which typically contains 4-carboxybenzaldehyde (4CBA), color bodies and other impurities, in aqueous liquid phase solution at elevated temperature and pressure.