Abstract

CO2 emissions have raised alerts worldwide due to their contribution to global warming. Thus, many efforts have been made to develop technologies to capture CO2 from the atmosphere and interest in utilizing adsorbents originating from natural raw sources increasing sustainability. In this work, Zeolite-A was synthesized from Kaolin material. Kaolin was previously calcined at 650 degrees C to form the Metakaolin. The obtained Metakaolin was submitted to hydrothermal treatment in an aqueous solution of sodium hydroxide and treated at 60 degrees C for 24 h without using other sources of silica and alumina species. The materials were characterized by X-ray diffraction (XRD), Al-27 NMR, infrared spectroscopy (FTIR), N-2-physisorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The synthesized Zeolite-A material was evaluated in the CO2 adsorption on a fixed bed reactor using a continuous flow system. The Yoon-Nelson model was used to predict the breakthrough behavior of CO2 adsorption in a fixed bed reactor using Zeolite-A material as an adsorbent. The role of pretreatment temperature of Zeolite-A prior to the CO2 adsorption capacity was accessed. Three different pre-treatment temperatures were used: 100 degrees C, 300 degrees C, and 400 degrees C. The Zeolite-A pretreated at 400 degrees C (Zeolite-A-400) exhibited the highest surface area. The CO2 adsorption kinetics of the Zeolite-A materials indicated a pseudo-first-order (PFO) kinetics suggesting physical adsorption of CO2 species on the Zeolite materials along with an intraparticle diffusion as the rate-controlling step of the whole adsorption process. The Yoon-Nelson rate constant (k(YN)) values and the time (tau) required for 50% adsorbate breakthrough offered pieces of evidence for the rationalization of the superior adsorption capacity noticed for the Zeolite-A-400 sample.