Geopolymers produced with fly ash and rice husk ash applied to CO2 capture

Abstract

The cement normally applied in carbon capture and storage sites as well lining or plugs may undergo degradation due to carbon dioxide (CO2) exposure, increasing the risk of CO2 gas leakage to the surface. Thus, finding a substitute is urgently necessary. This study reports the application of geopolymers produced with fly ash and rice husk ash as an adsorbent material for the capture of CO2. Different geopolymer formulations were used to produce mechanical resistance and CO2 adsorption capacity materials. The quantification of the reactive oxides in the precursor materials was carried out to obtain a better degree of geopolymerization. The geopolymers were characterized by X-ray diffraction (XRD), Brunauer - Emmett – Teller (BET), Scanning electron microscopy (SEM) and compressive strength analysis. Calcined rice husk ash activated by NaOH was found to be the most suitable precursor material to produce a geopolymer for CO2 adsorption, with a capacity 24.4% higher than the best geopolymer adsorbent reported in the literature to date.