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:
Apr. 25, 2000
Filed:
Jun. 16, 1998
Applicant:
Inventors:
Fu-Ming Lee, Katy, TX (US);
Wiston Lamshing, Katy, TX (US);
Randi Wright Wytcherley, Belgrade, MT (US);
Assignee:
HFM International, Inc., Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562487 ; 562485 ; 562414 ;
Abstract
A method and apparatus for preparing purified terephthalic acid and, optionally, isophthalic acid from mixed xylenes. The method of the present invention purifies the oxidation reactor effluent containing a mixture of terephthalic acid and isophthalic acid as well as minor amounts of 4-carboxybenzaldehyde (4-CBA), 3-carboxybenzaldehyde (3-CBA), and toluic acid isomers, to produce purified terephthalic acid and, optionally, purified isophthalic acid in an integrated process.