Mass Transfer Parameters for Packings: Effect of Viscosity

The effect of liquid viscosity (μ_L) on the effective mass transfer area (a_e) and liquid film mass transfer coefficient (k_L) of packing must be known to determine packing height. Most existing correlations are based on water and are not applicable to viscous systems. In this work, a_e, k_L, and gas film mass transfer coefficient (k_G) were measured in a 0.43 m ID packed column with 0.5–3 m of packing. Liquid viscosity was varied from 0.8 to 70 mPa·s by adding glycerol to water. Liquid viscosity has an insignificant effect on a_e over the range of μ_L investigated. The total dependence of k_L on μ_L is −0.75, of which −0.35 is indirect influence through diffusivity, and −0.4 is direct influence through liquid turbulence. Universal mass transfer models for packing were developed as functions of packing geometry, operating condition, and fluid property.