Experimental study of CO2 adsorption using activated carbon

The current study aimed to investigate the CO2 adsorption isotherms of activated carbon (AC), prepared from olive waste via chemical activation by H3PO4. The textural parameters, the microstructural and morphological characterization of the AC were characterized by N2 adsorption-desorption, SEM and XRD. The AC presented the best textural properties with a BET surface area of 1565 m2 g−1 and a micropore volume of 0.649 cm3 g−1. The CO2 adsorption was measured with a volumetric method at three various temperatures: 298 K, 308 K and 318 K. Different models, such as the Langmuir and Freundlich isotherms, were applied to model the CO2 adsorption. Based on the correlation coefficient (R2), the Langmuir model provided a the best fit with the experimental data. Different thermodynamic functions, such as Gibbs free energy and entropy, were calculated using Van Hoff’s formulation. These thermodynamic parameters indicated that the CO2 adsorption is an exothermic and spontaneous process. The results obtained in this study can serve as a benchmark while designing an adsorption-based gas storage system. the Freundlich