Study On L-phenylalanine Separation By Simulated Moving Bed

L-phenylalanine(L-Phe) is a kind of essential amino acids, it is a essential raw material of edulcorant: Aspartame and other intermediates, there are many demands of this amino acid. There are some flaw in L-Phe production inland, such as underproduction and in miniature. So it is an main research subject to reduce the cost of L-Phe separation. In this disquisition, the way of L- L-Phe separation by Simulated Moving Bed based on strong acid type ion exchange resin is studied. The Simulated Moving Bed separation technology is optimized by Standing Wave Design and applied to L-Phe production.The ammonia type resin WH6 has high adsorption capacity and favorable preferential adsorption to L-Phe in liquid of transformation after pretreatment. In static test, Optimized adsorption condition is adsorbed in normal temperature(10-25℃) for 6h, pH is 1.5. Adsorption capacity is 0.083g/g. In dynamic test, Optimized adsorption condition for column A(Φ40×227) is adsorbed in 5.5mL/min and fed 2.5L. Adsorption capacity is raised to 0.12g/g. Aqua pura washing condition is optimized, washing rate is 5.5mL/min, 750mL, the lost is about 0.96%. Desorption by ammonia concentration gradient to column A is optimized. Desorption temperature is 50℃, L-aspartic acid(L-Asp) and protein are first extracted from resin by aqua ammonia(0.2mol/L), then most L-Phe is extracted by stronger ammonia(0.5mol/L). When pH≤3.3 , L-Asp and protein are separated; the range of collection for L-Phe in extract is from pH3.3 to pH10.7, the recovery of L-Phe desorption is 95% , concentration is 30g/L in extract; when pH≥10.7, some residual L-Phe in extract is recovered.In Standing Wave Design of SMB, axial dispersion coefficient, film mass-transfer coefficient, internal and external diffusion are not negligible, process parameters are calculated and applied to SMB experiment and production. SMB experiment steady running for 4 days separated 110L transformation, adsorption and desorption waves of L-Phe or L-Asp are stable in relevant zones in continuous...