Gas phase axial dispersion in a packed column oxygen absorber

Gas phase axial dispersion was characterized within an enclosed packed column receiving oxygen and water under counter-current flow conditions. Steady-state gas phase profiles (longitudinal) were measured during a series of 90 column runs in which, at each of three bed depths (0·362, 0·699, and 1·041 m), all combinations of the following independent variables were tested: influent volumetric oxygen-liquid ratio, 0·8, 1·6, 2·6, 4·0, and 8·0%; hydraulic loading, 32·0 and 61·2 kg/m² s; and packing type, 2·54 cm Tri-Pack^®, 3·81 cm Nor-Pac^® and 5·08 cm Nor-Pac^®. Over the range of operating conditions tested, gas phase mixing was extensive and for all practical purposes could be considered complete. A homogeneous gas phase within the column, unlike true counter-current flow, results in an exponential decay in dissolved gas deficits as the liquid passes through the packing. Thus, increases in packed bed depth will result in diminishing increases in gas absorption/desorption.