Document Type: Research Article
Department of Chemistry, Faculty of Science, Islamic Azad University, North Tehran Branch, Tehran, I.R. IRAN
Department of Chemical Engineering, University of Science and Technology, Tehran, Iran.
In this research, activated carbon (AC) was modified using sodium hydroxide solution for CO2 adsorption. Adsorption experiments were carried out in a batch reactor at a temperature range of 20-80°C and a pressure range of 2-10 bars in order to investigate kinetic, isotherm and thermodynamic of the CO2 adsorption process. Activated carbon was modified with NaOH solution concentration in the range of 10-40%. Response surface methodology (RSM) was used to assess the combined effect of adsorption CO2 pressure and temperature on CO2 adsorption capacity. Also, RSM was used to obtain the optimum operational conditions. The results showed that modified activated carbon with 30% NaOH concentration (30SH-AC) provided the best performance for CO2 adsorption. The optimum CO2 adsorption capacity was obtained 104.32 mg/g for 30SH-AC at temperature of 20°C and pressure 6 bars. The sips model was found to be the best for fitting the CO2adsorption isotherm. Also, the kinetic study indicated that pseudo-second-order model is well-fitted with the experimental data. The thermodynamics parameter shows that the CO2 adsorption process is exothermic in nature.