Impact of CO2 cycloaddition reaction on hydrodynamics and mass transfer behavior of CO2-ionic liquid system in a capillary reactor

Gas-liquid hydrodynamic characteristics under chemical reaction-enhanced mass transfer are crucial parameters for analyzing mass transfer behavior in microreactor, which can facilitate the optimization of the reaction conditions to achieve efficient mass transfer and improve catalytic performance. Herin, the movement and shrinkage of CO 2 bubbles in the microreactor were visualized and monitored using a high-speed camera. Four typical patterns such as bubble flow, bubble-Taylor flow, Taylor flow and Taylor-annular flow were observed, and the impact of temperature on flow pattern transition lines was investigated. Furthermore, the correlation models for predicting dimensionless initial CO 2 bubble length ( L B / d ) and liquid-side volumetric mass transfer coefficient were developed to illustrate the effects of reaction conditions on the hydrodynamics and mass transfer behavior of CO 2 bubble accompanying the chemical reaction. This work deepens the understanding of the hydrodynamics and mass transfer characteristics in a real CO 2 cycloaddition reaction system and provides a theoretical basis for the design and optimization of gas-liquid microreactor.