Preparation of activated carbon from fly ash and its application for CO2 capture

Abstract

Power and desalination plants are one of the main anthropogenic sources for CO2 generation, which is one of the key elements to cause greenhouse gas effect and thus contribute to the global warming. Fly ash (FA) generated in desalination and power plants was converted into activated carbon (AC) treated with KOH at higher temperature and tested for CO2 capturing efficiency. Morphological characteristics of FA such as BET specific surface area (SSA), pore volume, pore diameter, and pore size distribution (PSD) were performed using N2 adsorption isotherm. CO2 adsorption capacity and adsorption isotherms of CO2 over AC were measured by performing thermogravimetric analysis at different temperatures. BET SSA of 161 m2g−1 and adsorption capacity of 26mg CO2/g AC can be obtained by activation at KOH/FA ratio of 5 at 700 °C and activation time of 2 h. Therefore, great potential exists for producing AC from FA, which will have the positive effect of reducing the landfill problem and global warming.