| 摘要 |
PCT No. PCT/GB97/00177 Sec. 371 Date Oct. 7, 1998 Sec. 102(e) Date Oct. 7, 1998 PCT Filed Jan. 21, 1997 PCT Pub. No. WO97/27170 PCT Pub. Date Jul. 31, 1997An indirect acidulation process for producing glutamic acid from an aqueous feed containing a glutamate resulting from fermentation includes: a) contacting an aqueous feed stream at an elevated temperature with a weak acid cation exchanger (WACE) which is at least partially in its acid form, whereby a part of the cations in the solution is taken up by the cation exchanger and protons are introduced into the solution; b) contacting a second aqueous feed containing glutamate and cations at an elevated temperature with a strong acid cation exchanger (SACE) that is obtained from a subsequent step and carries cationic glutamate, whereby the cationic glutamate is transferred into the solution and most of the cations in the second aqueous feed are taken up by the SACE; c) crystallizing glutamic acid from the effluent of step (b); d) contacting the mother liquor of step (c) with the SACE which is at least partially in its acid form whereby cationic glutamate is bound; e) utilizing the SACE obtained in step (d) in step (b); f) regenerating the SACE from step (b) to its at least partially acid form by a solution of a strong acid and utilizing the SACE in its at least partially acid form in step (d) while forming an effluent containing an acidic solution of salts, comprising cations bound to the cation exchanger in step (b) and the anions of the strong acid; g) regenerating the WACE from step (a) to its at least partially acid form by the effluent from step (f) and utilizing the WACE in its at least partially acid form in step (a) while forming an effluent containing a solution of salts, comprising cations bound to the cation exchangers in steps (a) and (b) and the anions of the strong acid; and h) directing the salt solution obtained as the effluent of step (g) for commercial use. |
