An experimental study of pressure drop characteristics under single-phase flow through packed bed microreactors

Packed bed microreactors offer a promising platform for intensifying heterogeneously catalyzed reactions. To understand hydrodynamics therein, N₂ or water flow was investigated experimentally through microreactors packed with glass beads in this work, corresponding to a microreactor to particle diameter ratio (D/d) of 1.29–25.12. The porosity of a single pellet string microreactor (D/d < 1.866) agrees with the literature's theoretical equation. For microreactors with larger D/d ratios, an empirical porosity correlation is proposed to address the dense packing nature of the bed. The existing correlations are inadequate to describe the pressure drop data in microreactors within the entire D/d ratios and modified Reynolds numbers (Re_m < 291). At D/d ≥ 3, the measured pressure drop is described by the modified Ergun equation using properties of the bulk bed zone to exclude the wall effect. At D/d < 3, it can be predicted by introducing a correction term for the wall effect into the Ergun equation.