화학공학소재연구정보센터
Powder Technology, Vol.373, 446-458, 2020
Fixed bed adsorption as affected by thermodynamics and kinetics: Yellow tuff for CO2 capture
In this work, a yellow tuff has been proposed for the first time as sorbent for CO2 capture. Dynamic breakthrough experiments have been performed in a fixed bed reactor at different temperatures (25-150 degrees C) and CO2 partial pressures (0.01-020 atm), focusing on the process thermodynamics and kinetics. The thermodynamic and kinetic studies highlighted that the CO2 adsorption on the tuff in the low pressure region typical of combustion flue gases can be properly described by Freundlich's isotherm model and by the pseudo-first order kinetic model, respectively, thus indicating a physical, multilayer and heterogeneous surface binding mechanism. Based on the results obtained, it has been demonstrated that, in the framework of a real application for post-combustion CO2 capture, the natural tuff, i.e. a low-cost natural sorbent, could be more conveniently employed in vacuum swing or mixed mode in order to minimize the energy penalty of the process. (C) 2020 Elsevier B.V. All rights reserved.