Modeling, equilibrium and kinetics of CO2 adsorption in LTA zeolite obtained from clay

This paper discussed the synthesis of LTA zeolite from Pinheiro clay (PIN) aiming for adsorption of CO2. To obtain the LTA-PIN zeolite, the PIN was submitted to acid treatment, followed by calcination and hydrothermal treatment. These treatments promoted the reorganization of the crystalline structure of the PIN, leading to the LTA-PIN zeolite with 95.79% purity confirmed by XRD, SEM, XRF, and FTIR results. The performance of the LTA-PIN zeolite was similar to the one of the standard LTA zeolite. The CO2 adsorption by the zeolites could be properly described by the pseudo-second-order kinetic and Freundlich isotherm models, suggesting that physisorption was the main mechanism responsible for the deposition of CO2 at the surface of the zeolites. According to regeneration results, LTA-PIN zeolite can be reused five times without significant loss of CO2 adsorption capacity, contrary to the 12% reduction in CO2 adsorption capacity presented by the LTA-standard zeolite.