Impact of the Channel- to Particle-Diameter Ratio on the Liquid–Liquid Mass Transfer and Pressure Drop in Micro Packed Bed Reactors

Micro packed bed reactors (MPBRs) operated by feeding with two immiscible liquids are of increasing importance in the chemical, biochemical, and energy industries. Herein, the impact of the channel- to particle-diameter ratio (N) on the liquid–liquid mass transfer and pressure drop in MPBRs is experimentally investigated. The experimental results reveal that both the overall volumetric liquid–liquid mass transfer coefficient (kLa) and pressure drop per unit length (ΔP/Lc) increase with the total flow rate (Qtot) for MPBRs of low to high N. The wall effects depend on Qtot, and the larger the Qtot, the more significant the wall effects. At small values of Qtot, kLa decreases slightly with N and increases marginally with the organic- to aqueous-phase flow rate ratio (φ); ΔP/Lc increases inappreciably with N and φ. At large values of Qtot, kLa declines significantly with N and increases appreciably with φ; ΔP/Lc increases significantly with N and φ. Correlations for calculating kLa and ΔP/Lc of the MPBRs are developed, yielding predictions that are in reasonably good agreement with the corresponding experimental data.