Adsorption equilibrium and kinetics of SO2 on activated carbon

Abstract：The adsorption equilibrium and kinetics of the flue gas SO2 removal on activated carbon were investigated based on a fixed bed reactor.The results show that there is a rapid SO2 adsorption rate on activated carbon in the initial stage,which is determined by the surface adsorption,after that the adsorption rate drops sharply due to the effect of intraparticle diffusion,and then the adsorption rate drops slowly and the amount of SO2 adsorbed increases slowly until the adsorption equilibrium,which is determined by the desorption rate of H2SO4.The SO2 adsorption rate and the amount of SO2 adsorbed increases with decreasing the particle size of activated carbon and increasing SO2 inlet concentration.The Bangham kinetic model can be used to predict the kinetics of SO2 adsorption on activated carbon of different particle size under different SO2 inlet concentration.Compared with Langmuir adsorption isotherm model,Freundlich adsorption isotherm model presents better fitted results for SO2 adsorption equilibrium on activated carbon of different particle size.