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

Abstract

This paper discussed the synthesis of LTA zeolite from Pinheiro clay (PIN) aiming for adsorption of CO 2 . 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 CO 2 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 CO 2 at the surface of the zeolites. According to regeneration results, LTA-PIN zeolite can be reused five times without significant loss of CO 2 adsorption capacity, contrary to the 12% reduction in CO 2 adsorption capacity presented by the LTA-standard zeolite.

Extraction of silica from sugarcane bagasse ash and its utilization in zeolite 4A synthesis for CO2 adsorption

“…The results are consistent with the adsorption kinetic model of CO 2 on various zeolites including 13X, 5A, and 4A. 52,53…”

“…The results are consistent with the adsorption kinetic model of CO 2 on various zeolites including 13X, 5A, and 4A. 52,53 One should note that the capacity of dynamic CO 2 adsorption in commercial NaA is lower than those in NaA-P and NaA-PS, the opposite trend from the result of static adsorption isotherm measured by Autosorb IQ3 in Fig. 8.…”

“…Moreover, the adsorption kinetics of CO 2 was investigated and analyzed according to the pseudo-rst and pseudo-second order models reported in the literature on various zeolites. 52,53 The pseudo-rst-order model (eqn (4)) assumes that the concentration of one reactant is much higher than the concentration of the other reactants 52 ln(q e − q t ) = ln q e − k 1 t…”

“…Moreover, the adsorption kinetics of CO 2 was investigated and analyzed according to the pseudo-first and pseudo-second order models reported in the literature on various zeolites. 52,53 The pseudo-first-order model (eqn (4)) assumes that the concentration of one reactant is much higher than the concentration of the other reactants 52 ln( q e − q t ) = ln q e − k 1 t where q t (mmol g −1 ) is the amount of adsorbate adsorbed at the time of t (minute), q e (mmol g −1 ) is the adsorption capacity at equilibrium and k 1 (min −1 ) is the rate constant of the pseudo-first-order.…”