Separating L-Valine With Simulated Moving Bed Ion-exchange Chromatography

L-Valine is one of the necessary amino acid to human being, and it's also a basic stuff to synthesize proteins, which is applied in medical, chemical, agriculture and food industry widely. There's many byproducts during the process of producing L-Valine, in which Alanine is difficult to separate by traditional methods for its similar structure with Valine. The prize of L-Valine is restricted by its impurity, an effective separation tool is vital to the quality of L-Valine. Simulated Moving Bed technology is an advanced separation method with high resolution, it will gain a large economic and social benefit by means of SMB technology for separating Valine broth. First, the separation of L-Valine on a single chromatographic column was investigated. The ion-exchange condition and the ion-exchange resin was selected by a mass of static adsorption test and dynamic adsorption test. NH4+ ion form resin was chose to further test. The optimum adsorption pH is 2. Ammonia is selected as optimum eluent with concentration is 0.5 mol/L. The chromatographic model was established, which is based on general rate model. The simulation program is coded by MATLAB language, and was used in the simulation for the separating of L-Valine. The bulk-fluid phase and the particle equations are first discretized using the Finite Element and the Orthogonal Collocation methods, respectively. The simulation fits the experimental data well, which provides a foundation for further simulation of SMB system. The mathematical model of SMB chromatography was set up by TMB approach, and the theoretic optimum operation parameters were deduced by Massimo's Triangle Theory. The practical optimum parameters were identified by test around theoretic value. The Valine and Alaine were separated under this condition, and Valine was received in extract port with purity 98.6%,Alanine was received in raffinate port with purity 82.9%. For there's lots of pigment in extract stream, decoloring and crystallization process is needed in order to get qualified product. The optimum processing parameters were identified by orthogonal design method, with which result in qualified white scalelike Valine.