ABSORPTION OF GASES INTO ACTIVATED CARBON WATER SLURRIES IN A STIRRED CELL

A surface-aerated stirred cell with a flat liquid surface was used to investigate the absorption of propane and ethene gas into slurries of activated carbon and water. Slurries with a solids concentration up to 4% by weight and particle diameters up to 565-mu-m were used. The experimental mass transfer data were interpreted using a three-resistance model (gas-liquid, liquid-solid and intraparticle resistance). The gas-liquid mass transfer coefficient was found to be enhanced by the presence of small carbon particles in the slurry, the maximum enhancement factor being 3.5. This enhancement was not influenced by the addition of 0.6% by weight of large particles (d(p) = 565-mu-m) to the liquid phase. Intraparticle resistance to mass transfer is low, which can be explained by assuming surface diffusion of the adsorbed molecules on the porous carbon.