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:
Jan. 09, 1990
Filed:
Apr. 27, 1989
Applicant:
Inventors:
Hobe Schroeder, Warrenville, IL (US);
David E James, Batavia, IL (US);
Assignee:
Amoco Corporation, Chicago, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ; B01J / ;
U.S. Cl.
CPC ...
562487 ; 502185 ; 562485 ; 562486 ;
Abstract
Aqueous solutions of crude terephthalic acid are purified by hydrogenation in the presence of plural noble metal catalysts in separate layers. Initially, the solution to be purified is passed through a layer of ruthenium-on-carbon catalyst, rhodium-on-carbon catalyst, or platinum-on-carbon catalyst, and thereafter through a layer of palladium-on-carbon catalyst. Optionally, the purified aqueous terephthalic acid solution can be treated further to decrease the 4-carboxybenzaldehyde content thereof by passing it through a layer of rhodium-on-carbon catalyst downstream from the palladium-on-carbon catalyst layer.