Crystallization technology: selective polymorphism of L-glutamic acid in anti-solvent crystallization

Nguyen Thi Ngoc Phuong, Khuu Chau Quang, Nguyen Dinh Tuyet, Tran Thi Dieu Thuy, Trinh Thi Thanh Huyen, Le Thi Hong Nhan, Phan Thanh Thao, Nguyen Anh Tuan

Abstract


The selective polymorphism of L-glutamic acid was firstly investigated in anti-solvent crystallization with a high productivity. When the ratio of feed solution and anti-solvent was varied from 90:10 to 80:20, the pure metastable α-form crystal was crystallized at 300C, 18.5g/l feed concentration and 360rpm of agitation speed. However, when the ratio of feed solution and anti-solvent was varied from 70:30 to 40:60, the mixture of α-form and b-form crystal product was precipitated. Further decreasing the ratio of feed solution and anti-solvent from 30:70 to 10:90, the only pure stable b-form crystal was crystallized. The results indicated that the supersaturation determined by the ratio of feed solution and anti-solvent was a key factor to impact on the nucleation process, in which the nucleation of α-form and b-form was favorably crystallized at a low and high supersaturation, respectively, which resulted in the selective polymorphism of L-glutamic acid in the anti-solvent crystallization.

Keywords. Crystallization, polymorphism, phase transformation, anti-solvent crystallization.

Keywords


Crystallization, polymorphism, phase transformation, anti-solvent crystallization