Daniel A. Green, DuPont Engineering Research & Technology, DuPont Experimental Station, Building E304-A222, Wilmington, DE 19880-0304 and Changzai Chi, Enginenering Research and Technology, DuPont Engineering Research & Technology, DuPont Experimental Station, Building E304-A222, Wilmington, DE 19880-0304.
Most industrial crystallization process technology is well established, with many years in operation. Consequently, there have been relatively few major improvements recently. Most industrial crystallization is done by creating supersaturation in stirred tanks with simultaneous crystal nucleation and growth. Since both nucleation and growth are strong functions of supersaturation, they can not in general be controlled individually in traditional crystallizers. In addition, new process technology is needed that can commercialize recent advances in the application of molecular and supramolecular control of crystallization, such as template directed crystal nucleation. We will review alternate crystallization process strategies that enable greater control of crystal properties. In particular, we will present research leading to a system that separates crystal nucleation and growth, and that can create templated nuclei.