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

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.