The creation and testing of a fully continuous tubular crystallization device suited for incorporation into flow chemistry setups

The study presents the use of a continuous crystallization device that can be directly incorporated into flow chemistry setups. Inside this device spontaneous nucleation and growth of organic molecules are controlled and maintained, using Aspirin as model molecule. The identification of the optimal crystallization scenario is discussed in view of the chemical stability of Aspirin and based on the determination of the solubility and the metastable zone width corresponding to the presented experimental setups. Physicochemical analyses combined with heat transfer modeling of the solution whilst flowing through a capillary placed inside a thermostated water bath provide the desired cooling profile and hence the degree of supersaturation along the system. The crystalline quality and stability of the crystalline output is evidenced for two different pump setups having distinguished flow patterns to show the independence on the flow stability, an important parameter for the success rate of the complete reaction scheme and in the perspective of operation scale-up. Reproducible output of material with narrow size distributions is obtained throughout all experiments.SCOPUS: ar.j