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:
Mar. 16, 2010
Filed:
Jul. 11, 2006
Hiroyuki Miura, Himji, JP;
Hidetaka Kojima, Himeji, JP;
Hiroyuki Miura, Himji, JP;
Hidetaka Kojima, Himeji, JP;
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
A process for producing a purified carboxylic acid having 'n+1' carbon atoms comprises feeding a carboxylic acid stream containing a carboxylic acid having 'n+1' carbon atoms, a hydrogen halide, a lower boiling point (bp) component, a higher bp component, and others to a first distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the first column; withdrawing a side stream containing at least the carboxylic acid by side cut from the first column; feeding the side stream to a second distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the second column; and withdrawing a side stream containing the carboxylic acid by side cut from the second column to recover a purified carboxylic acid; and the process further comprises feeding at least one first component (A) selected from the group consisting of an alcohol, corresponding to the carboxylic acid, having “n” carbon atom(s), and an ester of the alcohol with the carboxylic acid to the first column, and if necessary water. Such a process ensures reduction of the concentration of the hydrogen halide in the purified carboxylic acid.