Hydrodynamics of gas-liquid microfluidics: A review

Gas-liquid multiphase process occupies a significant part in the chemical industry, and the emerging gas-liquid microfluidic technology provides a highly efficient and controllable tool for gas-liquid systems such as chemical product synthesis, gas separation, and environmental protection. To point out the microscale gas-liquid multi-phase process from the fundamental study to its utilization, this review mainly focuses on advances in the hy-drodynamics of the gas-liquid microdispersion and microflow for the design of the gas-liquid microfluidic device. The progress of the gas-liquid flow pattern is first introduced, and then the microdispersion in both single-channel and multi-channel are summarized from the bubble size prediction model and operating condi-tions. Besides, the microflow characteristic of bubble movement velocity and pressure drop in a single-channel and flow distribution in multi-channels for scaling-up are presented, and the design procedure of gas-liquid microreactors is proposed. Finally, a summary and perspective are provided.