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:
Oct. 27, 1998
Filed:
Sep. 02, 1997
Steven W Felman, Granger, IN (US);
Chetna Patel, Naperville, IL (US);
Bhalchandra H Patwardhan, Granger, IN (US);
David J Solow, Elkhart, IN (US);
Bayer Corporation, Elkhart, IN (US);
Abstract
The disclosed invention provides for two improved processes for recovering citric acid and other organic acids. The process for recovering citric acid from an impure process stream includes concentrating the impure process stream to obtain a concentrated solution of citric acid, adding a sufficient amount of a strong acid or salt to the solution in order to crystallize citric acid and separating the resulting citric acid crystals from the mother liquor. The useful strong acids or salts thereof are sulfuric acid, hydrochloric acid, sodium chloride, sodium sulfate and nitric acid. Also ion exchange resins may be utilized in order to recover additional yields of citric acid. Further, the impure process stream is obtained by a solvent extraction process or a lime and sulfuric acid process. The other useful process provided for by the invention includes recovering organic acid from an impure process stream, such as a fermentation broth. However, the acid is added to the impure process stream in the first step and then concentrating the resulting impure process stream to recover crystals from the concentrate thereof. This particular improved process is essentially one step purification without the waste disposal problems or large capital investment required by either the conventional lime/sulfuric or solvent extraction recovery processes.