Gas-liquid two-phase flow in a square microchannel with chemical mass transfer: Flow pattern, void fraction and frictional pressure drop

The dynamics of the gas-liquid two-phase flow are of great significance for the heat and mass transfer performance in a microreactor. In this paper, the flow pattern, void fraction and frictional pressure drop of gas-liquid two-phase flow of CO2 and MEA/[Bmim][BF4] aqueous solution accompanied by the chemical reaction in a 400 μm square microchannel were investigated experimentally by a high-speed camera and pressure sensor. Three kinds of flow regimes were observed: slug-bubbly flow, slug flow and slug-annular flow. The void fraction and frictional pressure drop in the slug flow regime were mainly investigated, and the applicability of models without consideration of the mass transfer proposed in the literature was assessed. Considering the effect of chemical absorption, two correlations were proposed with the Hatta number for predicting the two-phase void fraction and Chisholm parameter C, which showed good prediction performance.