Improving CO₂ adsorption with new amine-functionalized Y-type zeolite

Abstract

In this work, a new synthesized Y-type zeolite with an Si/Al molar ratio of 2.5 (NaY) was modified with amines, in order to probe the influence of the modification of the adsorbent's surface on CO₂ adsorption. The three selected amines were diethanolamine, tetraethylenepentamine, and 2- methylaminoethanol. The surface nature of NaY was changed after amine modification, which causes a significant increase in the CO₂ adsorption capacity. The CO₂ adsorption capacity of the amine- modified NaY increased with temperature. The mechanism of CO₂ adsorption on NaY is usually a physical interaction, but it seems that after amine modification, chemical mechanism is the dominant mechanism for the chemical interaction between CO₂ and amine groups. The adsorbents were characterized by surface area and porosity analysis, X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. The CO₂ adsorption capacity was measured by the volumetric method at 298 and 348 K. The CO₂ adsorption capacity of TEPA-NaY, DEA-NaY, and 2-MAE-NaY at 298 K was 60.63. The CO₂ adsorption capacity of TEPA- NaY, DEA-NaY, and 2-MAE-NaY at 348 K were 92.9, 78, and 85.42, respectively. These results showed that amine-functionalized NaY zeolites have excellent adsorption potential for CO₂ adsorption at high temperatures.