Nucleation and crystal growth in limited crystallization field

Abstract

The crystallization operation is widely used in chemical processes and is one of the unit operations which deals with crystallization phenomena. The purposes of crystallization are to separate desired component and to produce crystalline particles. However, phenomena of crystallization are not simple and the relationships between operation conditions and product specification are complicated. The driving force of crystallization is supersaturation in nonequilibrium process. So the operation strategy for designing supersaturation is important to keep the high quality of size distribution and crystal morphology. In the general crystallizer, nucleation and growth occur in the same location and at the same time, because the driving force of both phenomena is only supersaturation. However, if the location and start period of nucleation and growth can be limited separately, it becomes easy to control the quality of crystalline particles. In this chapter, the examples which controlled the quality of crystalline particles by designing both nucleation and growth phenomena in a limited crystallization field are introduced.