N‐shape Pressure Drop Curve of Gas–liquid Microchannel Reactor and Modeling

Accurate prediction of gas-liquid pressure drop is essential to microreactors design; however, the understanding of general rules of pressure drop in a wide gas-liquid flow ratio, especially smaller than 1.0, remains insufficient, Accordingly, this work systematically studies the pressure drop rule within the gas-liquid flow ratio of 0.2-2.0. The results show that, under a given gas velocity, the pressure drop first increases and then decreases, and finally back increases with the liquid flow velocity, and the named N-shape pressure drop curve could be clearly observed. Besides, the rules of gas-liquid unit length and gas-phase holdup are explored to reveal the mechanism behind the N-shape pressure drop curve. Finally, three semi-empirical correlations based on the gas-liquid unit length and separated flow model are successfully proposed for the N-shape pressure drop. This work provides some important fundamental information for the reliable design of gas-liquid microreactors.