Studies On The Theory Of Glutamic Acid Crystallization And Its Application

In this thesis, the theory of L-glutamic acid (GA) crystallization and its application was studied. Nucleation and growth rates of secondary nuclei of GA were investigated when different concentration of its anion form (GA~王) coexisted and different size and quantity of seeds were added. The application of the theory was also studied. The fine seed crystals with radius 20~80μm were prepared with inductor ultrasonic waves acting on supersaturated solution of GA, with which the broth was seeded in the proceeding of iso-electric point isolation of GA. A new method of GA crystallization in the broth with addition of fine seed crystals, instead of crude crystals of GA which often used as seeds in the traditional method of crystallization, was obtained. The results show that, the secondary nucleation rates increase with increases of size and quatity of seeds, and are suppressed by GA~王 at lower supersaturation, and promoted at higher one . The growth rates of crystals decrease with increases of crystal size and concentration of GA~王 coexisted. More uniform crystals are obtained when seeds with smaller size are added in the crystallization. By using the new method of crystallization with addition of fine seeds, larger and more uniform crystals are obtained, the yield increases 2~ 3%, and the period of crystallization and precipitation decreases 6 hours...