Process for making terephthalic acid

摘要

A process for making terephthalic acid of high purity by feeding an aqueous equilibrium hydrolysis solution of terephthalonitrile to a reactive distillation column operated at a temperature of from about 200 DEG C to about 260 DEG C at autogenous pressure where the equilibrium solution is subjected simultaneously to further hydrolysis and distillation of ammonia while maintaining the concentration of aromatic materials in the aqueous liquid in said column sufficiently high to effect precipitation of dissolved terephthalic acid, removing the water vapor and ammonia from the top of the column, subjecting bottoms product in said column to further hydrolysis and distillation in a reboiler, returning vapor from the reboiler to the distillation column, removing an aqueous slurry of terephthalic acid from the reboiler and separating terephthalic acid product.