PHYSICAL AND CHEMICAL MASS-TRANSFER ENHANCEMENT AT A GAS-LIQUID INTERFACE DUE TO FINE CATALYST PARTICLES

Sulphur dioxide absorption rate in sulphuric acid solutions and activa ted carbon slurries was studied in a flat interface stirred cell. Expe riments were performed in which the stirrer speed, the weight fraction of catalyst, the particle size and the partial pressures of both SO2 and O-2 were varied. The gas-liquid mass transfer rate was found to be enhanced by the presence of powder activated carbon in the liquid fil m close to the interface. As the heterogeneous oxidation rate of sulph ur dioxide was slow compared to the adsorption rate, and the activated carbon used had a very high adsorption capacity, the enhancement was probably due to both the shuttle effect and the adhesion of the powder ed catalyst to the gas-liquid interface.