N‐shape pressure drop curve of gas–liquid microchannel reactor and modeling

Abstract 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.