Industrial Crystallization – the Intersection of Solid State Chemistry and Process Engineering

Crystallization is a complicated molecular recognition and self-assembly process that is completely managed by manipulating macroscopic process variables. Oftentimes, the crystallographic state of the resulting product is critial to its performance. The efficacy of products as diverse as pharmaceuticals and pesticides is often very sensitive to polymorph, for example. In addition, the particle size distribution depends on multiple process parameters in complicated, often nonlinear ways. As many crystallized products have become more advanced, with increasing demands on product performance, industrial crystallization has had to adapt. Pratitioners tend to come to the field from either process engineering or solid state chemistry. While it is possible to stay in one’s own “lane” and contribute to the field, most successful practioners today are at least conversant with both sides of the chemistry/engineering “divide”. Cross-training and collaboration often contribute greatly to successful crystalline product development and scale-up.

I come to industrial crystallization from process engineering, but have come to appreciate the necessity of understanding solid-state chemistry to adequately develop processes and products. I’ll illustrate the interplay between process engineering and solid-state chemistry with several examples from several industries, and review where I think continued collaboration can lead to crystalline product control and improvement.