Design of integrated crystallization systems



A systematic procedure is developed for designing an integrated crystallization system by considering the interaction between crystallization and downstream processing. Potential problems related to unit operations such as filtration, washing, dewatering, recrystallization, and drying are anticipated and resolved by determining an operating policy and configuration for the crystallizer as well as the downstream units. The approach can be applied to both batch and continuous crystallizers. First, the possible impacts of particle-size distribution (PSD) on the downstream processing units are identified. This forms the basis for determining a target PSD in the second step. Third, possible means by which the desired PSD can be achieved are selected. Fourth, the alternatives thus generated are evaluated and compared to identify the best design. Heuristics are provided along the way to guide the decision making. Shortcut equipment models are used to compare the performance of the alternatives. The procedure is illustrated with two industrial examples, including the production of adipic acid.