Impact of the Channel-\nto Particle-Diameter Ratio\non the Liquid–Liquid Mass Transfer and Pressure Drop in Micro\nPacked Bed Reactors

Micro packed bed reactors (MPBRs) operated by feeding\nwith two\nimmiscible liquids are of increasing importance in the chemical, biochemical,\nand energy industries. Herein, the impact of the channel- to particle-diameter\nratio (<i>N</i>) on the liquid–liquid mass transfer\nand pressure drop in MPBRs is experimentally investigated. The experimental\nresults reveal that both the overall volumetric liquid–liquid\nmass transfer coefficient (<i>k</i><sub>L</sub><i>a</i>) and pressure drop per unit length (Δ<i>P</i>/<i>L</i><sub>c</sub>) increase with the total flow rate (<i>Q</i><sub>tot</sub>) for MPBRs of low to high <i>N</i>. The wall effects depend on <i>Q</i><sub>tot</sub>, and\nthe larger the <i>Q</i><sub>tot</sub>, the more significant\nthe wall effects. At small values of <i>Q</i><sub>tot</sub>, <i>k</i><sub>L</sub><i>a</i> decreases slightly\nwith <i>N</i> and increases marginally with the organic-\nto aqueous-phase flow rate ratio (φ); Δ<i>P</i>/<i>L</i><sub>c</sub> increases inappreciably with <i>N</i> and <i>φ.</i> At large values of <i>Q</i><sub>tot</sub>, <i>k</i><sub>L</sub><i>a</i> declines significantly with <i>N</i> and increases appreciably\nwith φ; Δ<i>P</i>/<i>L</i><sub>c</sub> increases significantly with <i>N</i> and φ. Correlations\nfor calculating <i>k</i><sub>L</sub><i>a</i> and\nΔ<i>P</i>/<i>L</i><sub>c</sub> of the MPBRs\nare developed, yielding predictions that are in reasonably good agreement\nwith the corresponding experimental data.