Non-isothermal kinetic study of CO2 sorption and desorption using a fluidizable Li4SiO4
Abstract This study considers the CO 2 sorption–desorption kinetics on a promising acid treated fluidizable Li 4 SiO 4 sorbent. To accomplish this both carbonation and decarbonation including dynamic the thermodynamic equilibrium are considered using Temperature Programmed Carbonation (TPC) and Temperature Programmed Decarbonation (TPDC) experiments. The proposed phenomenological based kinetics model is established by comparing its suitability using correlation coefficients ( R 2 ), lowest sum of squares (SSQ) of residuals, parameter spans for the 95% confidence interval and cross-correlation coefficients matrix. It is found that a Langmuir Hinshelwood Model (LHM) is the best to describe the CO 2 adsorption on Li 4 SiO 4 , while a Nucleation and Nuclei Growth Model (NNGM) with three dimensional growths is required to model the CO 2 desorption process. On this basis, it is speculated that the CO 2 adsorption rate over the acid treated porous fluidizable Li 4 SiO 4 is dominated by a surface reaction, while the CO 2 desorption rate is ruled by the formation and three dimensional growths (as hemisphere) of nuclei.