Method for the recovery of aqueous solutions of free, neutral .alpha.-amino acids from aqueous solutions of their alkali-metal salts

US5049283A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Hans Joachim Hasselbach · Gelnhausen, DE
• Axel Kleeman · Hanau, DE
• Herbert Klenk · Hanau, DE
• Horst Weigel · Rodenbach, DE

Key dates

• Filing date: Feb 21, 1990
• Grant date: Sep 17, 1991
• Expiry date: Feb 21, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C227/16
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Aqueous solutions of free, neutral .alpha.-amino acids are recovered from aqueous solutions of their alkali-metal salts. Two equally large rectifying columns filled with a strongly acidic cation exchanger in the H.sup.+ form are used, the discharge of the first column being connected to the head of the second column. The solution of the alkali-metal salt is at first delivered to the head of the first column, then the residual solution, reduced by the alkali-metal cations adsorbed in the exchanger, is displaced to the second column by means of the addition of water. A product-free forerun is first separated at the discharge of the second column and, when free .alpha.-amino acid begins to exit in the flow-off from the second column, the receiver is changed and the delivery of water to the head of the first column continues further until a mixed pH between 5 and 7 has been achieved in the receiver. Then, the previously first column is decoupled and regenerated, the previously second column, which is now the first column, is coupled to a freshly regenerated column as second column and the entire process is repeated as often as desired.