Separation And Purification Of L-proline From The Fermentation Broth

In this study, the separation and purification conditions of L-Proline including filtration,ion-exchange, decoloration, concentration and crystallization were studied systematically, in orderto increase the recovery efficiency and quality of L-proline from the fermentation broth．Among the three filtration methods of fermentation broth, the effect of plate and frame filter isthe best method. The best condition for filtration is:50-70℃, pH3.0-5.0, working pressure0.02-0.2Mpa, carbon amount of6-8%. Based on static adsorption and elution experiments, the highestadsorption and elution efficiency of L-proline on001x7cation exchange resin and201x7anionexchange resin were obtained．Through the static adsorption experiment, the influence of the temperature, pH and L-prolineconcentration to the equilibrium adsorption of001x7cation exchange resin and201x7anionexchange resin are investigated. The results show that two kinds of resin’s adsorption for L-prolinetakes on a downward trend slightly with temperature increases; The effect of pH on the adsorptionis not obvious. With the increase of L-proline’s concentration in the solution, the adsorptionquantity increases accordingly, but the adsorption rate decreases. Through the dynamic adsorptionexperiment, the best feeding flow rates for001x7cation exchange resin and201x7anion exchangeresin are1.6ml/min and1.3ml/min, respectively. The static elution experiment and dynamicelution experiment reveal that the best elution condition for001x7cation exchange resin is2.0mol/L of ammonia and the elution flow rate1.0ml/min, and for201x7anion exchange resin is0.3mol/L of hydrochloric acid, the elution flow rate0.7ml/min.Through the reverse osmosis experiment, the combined use of the reverse osmosis and thethree-way concentration is determined for the eluent. After through K-15predecolorizing carboncolumn and then decoloring further with5%powder carbon, the concentrate’s transmittance isimproved. Adding4%crystal seed, cooling the concentrated filtrate to40℃and then rising to50℃,can obviously improve crystal shape.