| Gas-liquid two-phase flow in microchannels has been the subject of increased research interest in the past few years. Microchannel reactors feature high surface to volume ratio, which greatly increase gas-liquid mass transfer and rapid heat transfer between the reactants. Microchannels have many critical applications, such as miniature heat exchangers, micro-scale process units, nuclear reactors. The development and implementation of micro-reactor technology provide new reaction pathways to find economical and environmentally benign solutions to chemical manufacturing. This work developed Eulerian--Volume of Fluid based numerical model using a commercial CFD code of Ansys Fluent to simulate CO2-H2O multiphase flow in micro-channels with mass transfer. The volumetric mass transfer coefficients of CO2 to water were determined from correlations developed from experiments.;The flow regimes of gas-liquid two-phase flow, including bubble, slug, slug-annular, annular, and flow region transition were reported in the simulation. The effects of flow rate, wall wettability, channel width, and inlet configuration were simulated. The critical hydrodynamic parameters, including bubble length, bubble velocity, and pressure drop, were analyzed. Pressure drops simulated are in good agreement with available experimental data reported. The two-phase frictional multiplier was determined accordingly. The new correlation considering inlet conjunction angle were developed to predict bubble length. This work provides theoretical support for the design of new CO2 absorption processes. |
