Progress and Opportunities for Utilizing Seeding Techniques in Crystallization Processes

Seeding is a significant but challenging task for optimizing crystallization process operation, product quality, and process efficiency. With the development of modern crystallization technology, there have been considerable advancements in seeding techniques in recent years. This article elaborates on how seeds affect the crystallization process, clarifies the qualitative connection between seeding parameters, defines the variables and product quality attributes based on a variable-based causal graph, and analyzes various possible factors that result in seeding-technique failure based on an Ishikawa diagram. The development of seeding-technique studies and existing problems are then systematically reviewed and discussed based on the qualitative and quantitative characteristics of seeds and the factors that influence seeding efficiency. Based on extensive research accomplishments, the challenges and opportunities for utilizing seeding techniques are analyzed, and potentially valuable seeding-technique topics and directions for improving crystallization are presented. In addition, a framework to guide seed recipe design and optimization is defined by combining simulation and experimental verification.