Investigating the effect of operation points on crystal quality in reactive crystallization using continuous flow with high shear stress

Abstract

To obtain crystalline particles with favorable quality, the relationship between operation points on the phase diagram during crystallization and the crystal quality in reactive crystallization has attracted significant attention. This study used a continuous flow with high shear stress (Taylor vortex flow) to elucidate the relationship and investigate an operation strategy to improve the crystal quality in reactive crystallization. This is because the continuous flow with high shear stress allows easy evaluation of the crystal quality at the various operation points estimated based on feed solution conditions by keeping the operation condition and suppressing agglomeration during the reactive crystallization. As a result, the crystal quality, such as the aspect ratio and crystal size distribution of crystalline particles, changed with solution pH and supersaturation. Furthermore, we produced crystalline particles with improved quality by designing an operation strategy due to the considering the influence of operation points on the crystal quality. Therefore, it is suggested that we have succeeded in clarifying the relationship between operation points and crystal quality, as well as in finding the operation strategy using the advantages of continuous flow with high shear stress.