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. 24, 2000
Filed:
Jun. 07, 1995
Donald W McQuigg, Mooresville, IN (US);
Charles Marston, Midland, MI (US);
Gina Fitzpatrick, Indianapolis, IN (US);
Ernest Crowe, Beech Grove, IN (US);
Susan Vorhies, Indianapolis, IN (US);
Reilly Industries, Inc., Indianapolis, IN (US);
Abstract
Described are preferred processes for recovering citric acid from a medium in which it is contained. The citric acid is recovered both effectively and in a form which is readily purifiable. In one preferred process, the citric acid-containing medium is contacted with a solid-phase free base resin having tertiary amine groups to adsorb the citric acid. The citric acid is then desorbed by displacement with a stronger acid, and a citric acid-containing fraction is collected substantially free from contamination by the stronger acid. In another preferred process, a citric acid-containing medium is contacted with a solid-phase divinylbenzene-crosslinked polymer having pyridine or aliphatic tertiary amine functions to adsorb citric acid, the contacting being at a temperature below about 40.degree. C. Adsorbed citric acid is then desorbed with hot H.sub.2 O at a temperature of at least about 75.degree. C. Unnecessary impurities such as those arising from the use of organic solvent or throughput inorganic acid desorbents are thereby avoided while at the same time achieving a commercially attractive recovery of the citric acid. Additional preferred modes and process features are also described.