| 摘要 |
A process for making an aromatic carboxylic acid of high purity by feeding an essentially equilibrium hydrolysis mixture of an aromatic nitrile to a reactive distillation column operated at a temperature of from about 200.degree.C. to about 325.degree.C. at autogenous pressure where the equilibrium mixture is subjected simultaneously to countercurrent contact with steam, ammonia and carbon dioxide, and to further hydrolysis and distillation of ammonia, removing water vapor, carbon dioxide and ammonia from the top of the column, subjecting remaining equilibrium hydrolysis mixture to further hydrolysis and distillation in a reboiler to which carbon dioxide is added, returning carbon dioxide, water and ammonia vapors from the reboiler to the distillation column, removing an aqueous solution of product acid from the reboiler, cooling said separated solution, and separating acid product of improved purity. In one embodiment of the invention the hydrolysis mixture is obtained by subjecting a nitrile from the ammoxidation of an alkyl aromatic compound to aqueous hydrolysis in a closed reactor at about 200.degree. to about 325.degree.C. until an essentially complete equilibrium is obtained. |
