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:
Nov. 04, 2003
Filed:
Jan. 03, 2002
Michael Charles Milner Cockrem, Madison, WI (US);
Istvan Kovacs, Madison, WI (US);
Idris Mohamednur, Madison, WI (US);
David Heidel, Decatur, IL (US);
A. E. Staley Manufacturing Co., Decatur, IL (US);
Abstract
A process is disclosed for purifying an aqueous feed stream comprising a product organic acid, such as lactic acid, and a strong contaminant, such as pyruvic acid or oxalic acid. The molar concentration of the product organic acid in the feed stream typically is at least 20 times greater than the molar concentration of the strong contaminant. The aqueous feed stream is contacted with a first immiscible basic extractant that has at least a 3-fold greater affinity for the strong contaminant than for the product organic acid. The majority of the strong contaminant and some product organic acid become complexed with the first immiscible basic extractant. The complexed first immiscible basic extractant is separated from the aqueous stream, thereby producing a first effluent stream that comprises product organic acid and that has a greater ratio of molar product organic acid to molar strong contaminant than the aqueous feed stream did. The complexed first immiscible basic extractant is contacted with a displacing acid. The first immiscible basic extractant has a greater affinity for the displacing acid than it does for the strong contaminant or the product organic acid, and as a result, product organic acid and strong contaminant are displaced over a period of time from the complexed first immiscible basic extractant, producing a second effluent stream that comprises a major amount of product organic acid and a third effluent stream that comprises a major amount of strong contaminant.