Using modified Avrami kinetic and two component isotherm equation for modeling of CO2/N2 adsorption over a 13X zeolite bed

Abstract

Post combustion capture is one of the major strategies for removing dilute CO2 from flue gases. Using appropriate adsorbents is an effective approach for post combustion CO2 capture. An industrial application of the CO2 adsorption process as well as the design of the necessary equipment requires an accurate model to determine the effect of various operating factors on the efficiency of the process. Previous studies used linear driving force (LDF) approximation for the mass transfer and single component isotherm equation to describe the kinetics and equilibrium conditions of CO2 and N2 on an adsorbent. In spite of all previous models that had high significant error of about 10%, this research proposes a novel fixed bed model with outstanding accuracy. For the first time, a modified Avrami kinetic (as a new kinetic model) and two components Toth isotherm are used for estimating the kinetic and equilibrium data of CO2/N2 adsorption on 13X zeolite. Model estimated values were in good agreement with actual data with an error in the range of 3–5%. Finally, the effects of various operating conditions including temperature, inlet CO2 concentration, adsorbent particle and flowrate on adsorption performance were investigated and it was concluded that the temperature is the most important and effective operating parameter on CO2 adsorption performance.