(45)  Date of Patent:  Aug. 19, 2014  (IO)  Patent No.:  US 8,809,576 B2  c12)  United States Patent  Schraven et al.  (54)  METHOD FOR PRODUCING A FREE ACID  FROM THE SALT THEREOF  (75)  Inventors:  Alexander Schraven,  Issum (DE);  Thomas Tacke,  Alzenau (DE);  Thomas  Haas,  Muenster (DE);  Christoph  Kobler,  Alzenau (DE);  Dieter Buss,  Aschaffenburg (DE);  Axel Ronneburg,  Erlensee (DE);  Olivier Zehnacker,  Recklinghausen (DE)  (73)  Assignee:  Evonik Degussa GmbH,  Essen (DE)  ( *)  Notice:  Subject to any disclaimer, the term ofthis  patent is extended or adjusted under 35  U.S.C. 154(b) by 506 days.  (21)  Appl. No.:  13/141,456  (22)  PCT Filed:  Feb.1,2010  (86)  PCT No.:  PCT /EP2010/051170  § 371 (c)(l),  (2), ( 4) Date:  Jun.22,2011  (87)  PCT Pub. No.:  WO2010/094554  (51)  Int. Cl.  C07F  9122  (2006.01)  (52)  U.S. Cl.  USPC ..............................................................  562/8  ( 58)  Field of Classification Search  None  See application file for complete search history.  (65)  Prior Publication Data  (30)  Foreign Application Priority Data  (56)  References Cited  U.S. PATENT DOCUMENTS  FOREIGN PATENT DOCUMENTS  OTHER PUBLICATIONS  (57)  ABSTRACT  12 Claims, 3 Drawing Sheets  5,817,870 A  10/1998 Haas et al.  5,831,121 A  11/1998 Haas et al.  6,291,708 Bl  9/2001 Cockrem  7,393,972 B2  7/2008 Pascaly et al.  8,372,595 B2  2/2013 Schaffer et al.  8,604,227 B2  12/2013 Petrat et al.  2004/0210087 Al  10/2004 Meng eta!.  2010/0068773 Al  3/2010 Marx et al.  2010/0190224 Al  7/2010 Poetter et al.  2010/0210871 Al  8/2010 Kobler et al.  2010/0261237 Al  10/2010 Verseck et al.  2010/0291644 Al  11/2010 Marx et al.  2010/0324257 Al  12/2010 Karau et al.  2011/0039313 Al  2/2011 Verseck et al.  2011/0118433 Al  5/2011 Potter et al.  2011/0118504 Al  5/2011 Haas et al.  2012/0034665 Al  2/2012 Haas et al.  2012/0041216 Al  2/2012 Sieber et al.  2012/0245375 Al  9/2012  2012/0264182 Al  10/2012  2013/0035403 Al  2/2013  2013/0052700 Al  2/2013  2013/0092233 Al  4/2013  2013/0130319 Al  5/2013  2013/0165672 Al  6/2013  2013/0165685 Al  6/2013  2013/0183725 Al  7/2013  2013/0245276 Al  9/2013  2013/0331580 Al  12/2013  Hannen et al.  Reinecke et al.  Schaffer et al.  Poetter et al.  Pawlik et al.  Schaffer et al.  Klasovsky et al.  Hannen et al.  Poetter et al.  Klasovsky et al.  Klasovksy et al.  DE  WO  WO  WO  WO  WO  WO  WO  WO  WO  WO  10 2006 052 311  00 64850  02 90312  2006 069129  2006 124633  WO 2006124633 Al *  WO 2008042958 A2 *  2009 156214  2010 000506  2010 006834  2010 094630  5/2008  11/2000  11/2002  6/2006  11/2006  11/2006  4/2008  12/2009  1/2010  1/2010  8/2010  PCT Pub. Date:  Aug. 26, 2010  US 2011/0257429 Al  Oct. 20, 2011  Feb. 19, 2009  (DE) ......................... 10 2009 009 580  US008809576B2  McMaster et al., The Neutral Ammonium Salts of Organic Acids and  their substituted Derivatives, J. Amer. Chem. Soc., 1918, 40(4), 683- 693.*  International Search Report issued Apr. 12, 2010 in PCT/EPl0/  51170 filed Feb. 1, 2010.  U.S. Appl. No. 13/001,204, filed Dec. 23, 2010, Reinecke, et al.  U.S. Appl. No. 13/002,519, filed Jan. 4, 2011, Haas, et al.  U.S. Appl. No. 14/126,607, filed Dec. 16, 2013, Hass, et al.  U.S. Appl. No. 61/239,634, filed Sep. 9, 2009, Kobler, et al.  U.S. Appl. No. 14/237,121, filed Feb. 4, 2014, Haas, et al.  U.S. Appl. No. 14/233,505, filed Jan. 17, 2014, Poetter, et al.  U.S. Appl. No. 14/238,591, filed Feb. 12, 2014, Schaffer, et al.  * cited by examiner  U.S. Appl. No. 14/238,576, filed Feb. 12, 2014, Schaffer, et al.  Primary Examiner  - Porfirio Nazario Gonzalez  Assistant Examiner  - Kofi Adzamli  (74)  Attorney,  Agent,  or  Firm  -Obion,  Spivak,  McClelland, Maier & Neustadt, L.L.P.  The invention relates to an improved method for releasing an  organic acid, preferably a carbon, sulfone or phosphone acid,  particularly an alpha or beta hydroxycarbon acid, from the  ammonia salt thereof by releasing and removing ammoniac  and simultaneous extraction of the released acid, having an  amine as a suitable extraction means from the aqueous phase.  This method corresponds to a reactive extraction. The reac› tive extraction of an organic acid from the aqueous ammonia  salt solution thereof can be significantly improved by the use  of a strip medium or carrier gas, such as nitrogen, air, water  vapor or inert gases such as argon. The released ammoniac is  removed from the aqueous solution by the continuous gas  flow and can be resupplied into a production process. The free  acid can be obtained by a method such as distillation, rectifi› cation, crystallization, reextraction, chromatography, adsorp› tion or by a membrane method from the extraction means. 