A Study on Desulphurization of Flue Gases by the Active Carbon Process Using Steam Desorption (Part 1)

As one aspect of the studies concerning desulphurization of flue gases by active carbon, the desorption of sulphur dioxide from active carbon was investigated. The adsorption of sulphur dioxide into the active carbon from flue gases at 100∼150°C is an adsorption involving chemical reactions, and the sulphur dioxide changes into sulphuric acid on the active carbon. The desorption rate of sulphur dioxide by thermal desorption is affected greatly by the temperature. The desorption reaction begins gradually at 200°C and the rate increases rapidly at 300°C. Sulphur dioxide and carbon dioxide are formed during the desorption and adsorbed water is eliminated at the same time. The molar ratio of the carbon dioxide to the sulphur dioxide is fixed by the temperature of desorption regardless of the quantity of sulphur dioxide adsorbed, and it is less than 0.5 when the temperature is under 750°C. The desorption reaction with superheated steam is a 1.5-order reaction, and the energy of activation is 7.98kcal/mol.