Influence of feeding mode on cooling crystallization of L-lysine in Couette-Taylor crystallizer

A continuous Couette-Taylor (CT) crystallizer was used to apply a multiple feeding mode strategy to enhance the crystal size and size distribution of L-lysine crystals in cooling crystallization. With a 5-min mean residence time, feed concentration of 900 g/l, and rotation speed of 700 rpm, the multiple feeding mode strategy Run-III (D21) produced a large crystal size of 139 μm and coefficient of variation (CV) for the size distribution of 0.39, both of which were significantly enhanced when compared with the conventional feeding mode Run-I (D1) that produced a crystal size of 82 μm and CV for the size distribution of 0.53. Essentially, the crystal size was enhanced around 70%, while the size distribution was improved around 28%. Finally, the impact of the multiple feeding mode strategy on the crystal size and size distribution is explained in terms of effective control of the supersaturation.