The experimental and kinetic insights into innovative K2SnO3 as a high-performance CO2 sorbent

This study explores the potential of potassium stannate (K₂SnO₃) as an effective sorbent for carbon dioxide (CO₂) capture, addressing the urgent need for advanced carbon capture technologies to mitigate climate change. Isothermal Thermogravimetric Analysis (ISO-TGA) and non-isothermal Thermogravimetric Analysis (nonISO-TGA) were utilized to examine the changes in mass as a result of temperature variations and exposure to a CO2 gas atmosphere. In order to assess the CO2 adsorption reaction mechanism, studies were conducted on the adsorption kinetics, activation energy, and CO2 adsorption. The optimal temperature for CO2 adsorption was found to be 773 K, which resulted in the maximum saturation of the adsorbent with low activation energy. Furthermore, it was observed that K2SnO3 exhibited a higher adsorption capacity, with 115 mg/g of maximum mass CO2 adsorbed, compared to other alkali stannate compounds (Ca, Na, Li) and stable oxide compounds (Zr, Sn). Employing various kinetic models, reveals that the adsorption process is predominantly governed by diffusion mechanisms, with a mean correlation coefficient (R²) exceeding 0.95 for the most suitable models. Additionally, the activation energy for the adsorption process was calculated at 73.55 kJ/mol, highlighting the efficiency of K₂SnO₃ in high-temperature environments. The findings from the reaction kinetic analyses provide valuable insights into the suitability and performance of this adsorbent for large-scale carbon capture applications.