No abstract

The membrane assisted cooling crystallization was proposed and investigated by the simulation and experiments. The developed process model concerned the supersaturation evolution on the membrane interface, the combined nucleation rate in the crystallizer. The impact of different membrane on reducing the nucleation barrier was investigated by introducing the metastable zone width theory. The influence of membrane distillation conditions on the crystal nucleation and growth kinetic was uncovered based on the simulation and experiments results. The experimental results indicated that membrane assisted cooling mode with optimized profiles did improve the crystal size distribution and crystal habit comparing with conventional cooling mode. Terminal coefficient of variation decreased from 55.4 to 33.9 under similar mean crystal growth rate, 2.27 3 10 27 m s 21 (conventional cooling) and 1.98 3 10 27 m s 21 (membrane assisted cooling). Finally, the brief summary on the advantages and key issues of this propose membrane assisted crystallization operation were concluded. V C 2015 American Institute of Chemical Engineers AIChE J, 62: [829][830][831][832][833][834][835][836][837][838][839][840][841] 2016

Herein, a novel hollow fiber membrane‐assisted antisolvent crystallization (MAAC) was proposed to enhance the mass transfer control over the antisolvent crystallization. A polyethersulfone membrane module was introduced as the key device for antisolvent transfer and solution mixing. An antisolvent liquid film layer was formed on the membrane surface and mixed with the solution. The liquid film also prevented the membrane from directly contacting with crystallization solution. By controlling both the shell side flow velocity and the antisolvent transfer, the antisolvent permeation rate achieved sensitive, stable, and accurate control during long‐term and repeated utilization. The interfacial mass transfer rate of MAAC was 0.66 mg cm−2 s−1, which was only 1/50 that of conventional droplet antisolvent crystallization. MAAC also provided crystal products with better morphologies and narrower size distributions than the conventional process. The stable performances of MAAC in terms of its accurate antisolvent mass transfer and antifouling capabilities were also highlighted. © 2018 American Institute of Chemical Engineers AIChE J, 65: 734–744, 2019