Evaluation of Silica gel adsorbent potential for carbon dioxide capture: experimental and modeling

In this research, silica gel as a low-cost adsorbent for carbon dioxide uptake was investigated experimentally. The samples were characterized by XRD, BET and FT-IR. It shows that as pressure was increased from 2 to 8 bar, CO2 adsorption capability improved over time. At a pressure of 6 bar and a dose silica gel of 1 g, the impact of temperature (25, 45, 65, and 85 °C) on CO2 adsorption capacity (mg/g) was determined. The process behavior was investigated using isotherm, kinetics and thermodynamic models. As the temperature rises at a constant pressure, the adsorption capacity decreases. The experimental data of carbon dioxide adsorption using silica gel have a high correlation coefficient with both Langmuir (0.998) and Freundlich (0.999) models. The results of the carbon dioxide adsorption kinetics with the silica gel adsorbent show that the correlation coefficient ( ) of the second-order model and Ritchie's second model are equal to 0.995 and have the highest value. The total pore volumes was 0.005119 (cm3 g-1) and the specific surface areas was 2.1723 (m2g−1). Maximum CO2 adsorption capacity at 25 °C near 8 bar was 195.8 mg/g.