Investigation of the CO2 adsorption isotherms on activated carbon by statistical physics treatment.

The aim of this paper was to study CO2 adsorption on the activated carbon (AC) prepared from olive waste. The AC was characterized via X-ray diffraction, Scanning Electron Microscopy (SEM) and N2 adsorption-desorption. The adsorption isotherms were measured at various temperatures, namely, 298 K, 308 K, and 318 K. Based on the experimental result, a new model was generated and evaluated by means of a multilayer model with saturation. The physicochemical properties that characterize the CO2 adsorption mechanism have been established using a physical statistical approach. The parameters which characterize the CO2 adsorption isotherm, such as the number of carbon dioxide molecules per site (n), the receptor site densities [Formula: see text], and the energetic parameters (ΔE1, ΔE2) were studied. In addition, thermodynamic functions such as internal energy (Eint) and Gibbs free energy (G), were established using a physics model. Thus, the obtained results indicated that the CO2 adsorption on the AC was exothermic and physisorption in nature. Furthermore, the results achieved with this model can be used to design and optimize an adsorption unit for CO2 capture.