Membrane Crystallization for Process Intensification and Control:A Review

Crystallization is a fundamental separation technology used for the production of particulate solids.Accurate nucleation and growth process control are vitally important but difficult.A novel controlling technology that can simultaneously intensify the overall crystallization process remains a significant challenge.Membrane crystallization(MCr),which has progressed significantly in recent years,is a hybrid technology platform with great potential to address this goal.This review illustrates the basic concepts of MCr and its promising applications for crystallization control and process intensification,including a state-of-the-art review of key MCr-utilized membrane materials,process control mechanisms,and optimization strategies based on diverse hybrid membranes and crystallization processes.Finally,efforts to promote MCr technology to industrial use,unexplored issues,and open questions to be addressed are outlined.

Progress in membrane distillation crystallization： Process models, crystallization control and innovative applications

Membrane distillation crystallization （MDC） is a promising hybrid separation process that has been applied to seawater desalination, brine treatment and wastewater recovery. In recent years, great progress has been made in MDC technologies including the promotion of nucleation and better control of crystallization and crystal size distribution. These advances are useful for the accurate control of the degree of supersaturation and for the control of the nucleation kinetic processes. This review focuses on the development of MDC process models and on crystallization control strategies. In addition, the most important innovative applications of MDC in the last five years in crystal engineering and pharmaceutical manufac- turing are summarized.

High-efficient crystal particle manufacture by microscale process intensification technology

High-end crystal manufacture has drawn a permanent concern on the high-efficient manufacture of crystal particles,especially in fine chemical,pharmaceutical,electronics,biological and relative engineering fields.In recent years,a series of microscale process intensification(MPI)technologies have been widely used in crystal particles preparation via addressing the control of nucleation and growth process.Herein,we review the research progresses of microscale process intensification technology from three aspects,microfluidics devices,microscale force field technology and membrane-based microchannels and interface transfer process.Firstly,the principle of microfluidic and relative microscale device on improving micro-mixing and mass transfer are briefly described.The advantage of microfluidic in continuous nano particle preparation is outlined.Microscale external force field(ultrasonic,high-gravity,electric and magnetic fields)is then introduced as another novel approach for ultrafine nanoparticles and continuous drug crystallization process.Further,in view of the micro-scale intensified mass transfer and microscale interfacial force field established on membrane technology,the basic mechanism of membrane crystallization(microscale 2D supersaturation degree control,auto seed detachment,microporous membrane dispersion,etc.)is reviewed.The process coupling and design strategy aiming for enhancing the manufacture capacity is also illustrated.Finally,the developing tendency and key challenges of high-efficient crystal particle preparation technology via microscale processes are overviewed.