Gas absorption rates in a stirred cell with plane interface in the presence of fine particles

Abstract

Abstract The rates of absorption of carbon dioxide into water and into 0.5 mol/L equimolar carbonate buffer solutions (containing varying amounts of arsenite) were measured in a stirred cell with plane interface in the presence of fine solids (activated carbon, kieselguhr and alumina). Experiments show that the absorption rate increases significantly when the activated carbon loading increases up to about 0.2 g/L and thereafter remains constant. No significant effects were observed for other solids. The results could be explained in terms of a “shuttle” mechanism where particles adsorb gas near the interface which is then followed by desorption (or reactions) in the bulk. At very high loadings (above 10 vol.%), the absorption rate decreased for all particles and this could be explained by the blockage of the interface and/or by the sharp increase in the suspension viscosity.