Process Design for Continuous Crystallization of l-Tryptophan in Water–Alcohol Solvent Mixtures

The study of solid–liquid equilibria in small molecules such as l-tryptophan (l-Trp), which possesses an α-amino group, an α-carboxylic acid group, and an indole compound, presents significant challenges. This research introduces several findings aimed at enhancing process efficiency and sustainability in downstream processing of l-Trp from fermentative origin via crystallization. Transitioning from batch to continuous processes allows for improved scalability and resource management. Furthermore, solubility measurements combined with thermodynamic data from the literature will provide deeper insights into molecular interactions and allow for systematic and data-driven process design. Lab-scale crystallization experiments in both batch and continuous operation allow for the assessment of the process feasibility and solvent impacts on the process and product. The focus is on process development that emphasizes material savings through strategic solvent selection and co-solvent choices.