Adsorption characteristics of flue gas components on zeolite 13X and effects of impurity

Abstract

Most of combustion processess used in industries require recovering or removing flue gas components. Recently a new MBA (moving bed adsorption) process for recovering CO2 using zeolite 13X was developed. In this study, adsorption experiments for carbon dioxide, nitrogen, sulfur dioxide, and water vapor on zeolite 13X were carried out. Adsorption equilibrium and adsorption rate into solid particle were investigated. Langmuir, Toth, and Freundlich isotherm parameters were calculated from the experiment data at various temperatures. Experimental results were consistent with the theoretically predicted values. Also CO2 adsorption amount was measured under the conditions with impurities such as SO2 and H2O. Binary adsorption data were well fitted to the extended Langmuir isotherm using parameters obtained from pure component experiment. However, H2O impurity less than, roughly, ∼10-5 H2O mol/g zeolite 13X enhanced slightly CO2 adsorption. Spherical particle diffusion model well described experimentally measured adsorption rate. Diffusion coefficients and activation energies of CO2, SO2, N2, H2O were obtained. Diffusion coefficients of CO2 and SO2 decreased with small amount of preadsorbed impurity. Parameter values from this study will be helpful to design of real commercial adsorption process.