Nanofiltration of L-phenylalanine and L-aspartic acid aqueous solutions

The permeation experiments Of L-phenylalanine (L-Phe) and L-aspartic acid ( L-Asp) aqueous solutions were carried out with two commercial nanofiltratio n (NF) membranes, ESNA2 membrane and ES20 membrane. The rejections to L-Phe and L-Asp by ESNA2 membrane are about 0 and 90%, respectively, at the pH v alue ranging from 4 to 9, while the rejections to L-Phe and L-Asp by ES20 m embrane are almost 100% irrespective of pH value. The results show that the se two NF membranes are possible to concentrate and separate L-Phe and L-As p effectively by choosing proper condition such as the pH value of solution . Based on the experimental results, a simple batch-wise NF process system was design for concentration and diafiltration of virtual L-Phe enzymatic r eaction solution with Some L-Asp. The simulation results show that it is fe asible to separate L-Phe and L-Asp in viewpoint of technology. (C) 2002 Els evier Science B.V. All rights reserved.