The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1977
Filed:
Jun. 17, 1975
Allen W Hancock, II, Media, PA (US);
William D Vanderwerff, West Chester, PA (US);
Sun Ventures, Inc., St. Davids, PA (US);
Abstract
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 further hydrolysis and distillation of ammonia, removing water vapor and ammonia from the top of the column, subjecting remaining equilibrium hydrolysis mixture to further hydrolysis and distillation in a reboiler, returning vapor from the reboiler to the distillation column, removing an aqueous solution of product acid from the reboiler, cooling said separated solution, separating acid product, and in order to improve product purity, returning the aqueous filtrate from said separated acid product to a lower portion of said column. 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.