Mixing and mass transfer at high liquid rates in the steady state counterflow operation of packed columns



Carbon dioxide absorption profiles have been measured for high liquidgas ratios in an absorption column operated at atmospheric pressure under steady state counterflow conditions. Mixing and mass transfer parameters were extracted from these profiles using an extension of the technique described by Brittan (1967). The flow ranges covered are 15 < Res < 100 and 300 < ReL < 1 600.

The dispersion data reflect the same trends as shown by dynamic testing methods (Woodburn, 1974). However, with decreasing liquid-gas ratios the effect of dispersion on steady state mass transfer becomes less significant than would be inferred from dynamic testing results.

Under reverse gas flow conditions, the mass transfer coefficients corrected for the effects of axial dispersion show the same functional dependency on liquid rate as given by the Sherwood and Holloway (1940) correlation and provide a quantitative explanation for the anomalous behavior exhibited by their results in this liquid range.