VERFAHREN ZUR ISOLIERUNG VON L-AMINOSAEUREN.

摘要

Sepn. of L-amino acids (I) from reaction solns. of the acylase-catalysed decomposition of N-acetyl-D,L-amino acids (II) uses a strongly acidic ion exchanger in proton form. The exchanger, at 30-90 (60-80) deg.C, is first treated with the mother liquor from a previous processing cycle, then with the reaction soln. and finally with wash water. The effluent is split into 3 fractions: (1) until the pH has fallen to 2; (2) until the pH, which falls further initially, has increased back to 2, and (3) until pH has increased to 5. The third fraction is combined with the effluent generated while waste water is applied, and the mixt. adjusted to pH 4-6 (4.5-5.5) by adding fresh reaction soln.. (I) is crystallised conventionally from this mixt. and the residual mother liquor used in the next processing cycle.