CO2 selectivity and adsorption performance of K2CO3-modified zeolite: a temperature-dependent study.

Abstract

High-performing zeolite materials for carbon dioxide capture are promising for applications such as flue gas CO₂ capture. Potassium carbonate-loaded zeolites can offer a plethora of benefits. In this work, for the first time, zeolite-Y impregnated with K₂CO₃ was studied as a gas adsorbent (CO₂, CH₄, and N₂) and characterized using TGA (thermogravimetric analyzer), XRD, BET, FTIR, FETEM (Field-Emission Transmission Electron Microscope), and XPS. The effect of carbonate loading, temperature, and pressure was particularly targeted and assessed. Accordingly, for a variation in K₂CO₃ loading from 5 to 15 wt.%, the CO₂ adsorption capacity reduced from 3.61 to 1.73 mmol g^-1 in the synthesized adsorbents. Among all the cases, KYZC10 exhibited very good cyclic adsorption-desorption performance and thermal stability. Further equilibrium modeling studies indicate that the stable and optimally K₂CO₃-loaded adsorbent (KYZC10) demonstrates effective adsorption isotherm behavior, making it suitable for different temperature variation processes in commercial carbon dioxide capture applications. The KYZC10 adsorbent's stable performance at varying temperatures contributes to its enhanced economic feasibility. This study also used the ideal adsorbed solution theory (IAST) to predict CO₂ selectivity over other gases (CH₄ and N₂).