Mass transfer in high-pressure bubble columns with organic liquids

Oxygen desorption from organic liquids (ethanol (96 %), 1-butanol, toluene) and water into nitrogen gas has been studied with an optical sensor. Gas hold-ups and volumetric mass transfer coefficients have been determined in the pressure range of 1-10 bar. In this range both quantities are found to increase with the gas density to the power of 0.24. However, by comparison with literature data and on theoretical grounds, the gas density effect can be shown to depend on the gas velocity and on gas density itself. The effect becomes negligible at gas velocities below 0.01 m/s and at gas densities below about 0.1 kg/m³.