KINETIC STUDY OF FLUE GAS DESULPHURIZATION WITH SODIUM CARBONATE AT LOW TEMPERATURE

This paper presents the kinetic study of the dry desulphurization process at low temperature using solid adsorbents by thermogravimetric analysis technique. Experiments are performed in isothermal conditions, at three temperatures (373 K, 473 K and 573 K) with diameters of sodium carbonate granules of 31.5 mu m and 900 mu m and sulfur dioxide concentration of 0.5 % and 1.0 %. The particle size, temperature and gas flow rate show a dominant influence on the variation of carbonate conversion. The obtained activation energy values are in the range from 4.234 KJ/mol to 12.275 KJ/mol showing that the diffusion through the solid product layer is the determinate rate step of the process. The experimental results confirm that the shrinking Unreacted Core Model can be used to describe the sulfation of sodium carbonate at low temperature.