Adsorption Kinetics for CO2 Capture using Cerium Oxide Impregnated on Activated carbon

Abstract

Various metal oxides of CeO₂, ZnO, and Co₃O₄ impregnated on activated carbon (AC) were synthesized to determine the CO₂ capture efficiency and analyse with adsorption kinetics model. Batch kinetic studies showed that CeO₂/AC is the most efficient adsorbent with an equilibrium time of 10 minutes that was needed to obtain adsorption capacity of 52.68 mg/g. CO₂ adsorption at 30 °C exhibits the optimum temperature with only 6.53% loss in adsorption capacity after 5 cycles of CO₂ adsorption-desorption. The CeO₂ on AC was detected through X-ray diffraction and the scanning electron microscope image shows well-distributed CeO₂ particles on AC surfaces. CO₂ adsorption at 30 °C is best fitted with the pseudo-second-order kinetics with R² = 0.9994 and the relative error between calculated and experimental adsorption capacity only 1.32%. The adsorption considering chemisorption is responsible for improving adsorption capacity. The addition of CeO₂ on AC enhanced the adsorption capacity by providing active sites to attract CO₂.