US 20100210871Al  c19)  United States  c12)  Patent Application Publication  Kobler et al.  c10) Pub. No.: US 2010/0210871 Al  (43) Pub. Date:  Aug. 19, 2010  (54)  REACTIVE EXTRACTION OF FREE  ORGANIC ACIDS FROM THE AMMONIUM  SALTS THEREOF  (75)  Inventors:  Christoph Kobler,  Alzenau (DE);  Dieter Buss,  Aschaffenburg (DE);  Axel Ronneburg,  Erlensee (DE);  Christoph Weckbecker,  Grundau-Lieblos (DE)  (51)  Int. Cl.  (73)  Assignee:  EVONIK DEGUSSA GMBH,  Essen (DE)  (21)  Appl. No.:  12/706,512  (22)  Filed:  Feb.16,2010  (60)  Provisional application No. 61/239,634, filed on Sep.  3, 2009.  Feb. 19, 2009  (DE) ......................... 102009001008.4  The invention relates to a process for converting ammonium  salts of organic acids to the particular free organic acid,  wherein an aqueous solution of the ammonium salt is con› tacted with an organic extractant and the salt is dissociated at  temperatures and pressures at which the aqueous solution and  the extractant are in the liquid state, and a stripping medium  or entraining gas is introduced in order to remove NH$_{3 }$ from  the aqueous solution and transfer at least a portion of the free  organic acid formed to the organic extractant. The invention  described here thus provides an improved process for releas› ing an organic acid, preferably a carboxylic, sulphonic or  phosphonic acid, especially an alpha-hydroxycarboxylic acid  or beta-hydroxycarboxylic acid, from the ammonium salt  thereof by release and removal of ammonia and simultaneous  extraction of the acid released with a suitable extractant from  the aqueous phase. This process corresponds to a reactive  extraction. The reactive extraction of an organic acid from the  aqueous ammonium salt solution thereof can be improved  significantly by the use of a stripping medium or entraining  gas, for example nitrogen, air, steam or inert gases, for  example argon. The ammonia released is removed from the  aqueous solution by the continuous gas stream and can be fed  back into a production process. The free acid can be obtained  from the extractant by a process such as distillation, rectifi› cation,  crystallization,  re-extraction,  chromatography,  adsorption, or by a membrane process.  Correspondence Address:  LAW OFFICE OF MICHAEL A. SANZO, LLC  15400 CALHOUN DR., SUITE 125  ROCKVILLE, MD 20855 (US)  (52)  U.S. Cl.  .............  562/8;  562/400; 562/579; 562/587;  562/512; 562/100  C07F 9/535  (2006.01)  C07C 61/00  (2006.01)  C07C 59101  (2006.01)  C07C 59/10  (2006.01)  C07C 53/126  (2006.01)  C07C 309125  (2006.01)  Publication Classification  (57)  ABSTRACT  Related U.S. Application Data  (30)  Foreign Application Priority Data  AQUEOUS  AMMONIUM SALT  SOLUTION OF AN  ORGANIC ACID  JACKETED COIL  CONDENSER  RESERVOIR WITH  EXTRACTANT 