Role of ultrasonic oscillation in chemical processes in microreactors: A mesoscale issue

The integration of microreactor and ultrasound represents an emerging area for process intensification and has attracted considerable attention in recent years. One of the most important meso-scientific issues in ultrasound techniques is acoustic cavitation, which plays a vital role in the macroscopic performance of an ultrasonic microreactor. In this review, we first briefly summarize the latest research on acoustic cavitation phenomena in microreactors. The effects of channel configuration, solvent properties, and ultrasound parameters are systematically reviewed. In addition, the role of acoustic cavitation in various chemical processes (e.g., mixing, absorption, emulsification, and particle synthesis) is presented from a mesoscale perspective, which in turn provides guidance for ultrasound applications. A thorough understanding of the ultrasound intensification mechanism will contribute to the future development of this promising technology. (C) 2019 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.