Sepiolite-based adsorbents for carbon dioxide capture

Sepiolite and the sepiolite-based materials were studied in terms of carbon dioxide adsorption. The pore structure and the surface characterization of the obtained materials were specified based on adsorption-desorption isotherms of nitrogen measured at –196^oC and carbon dioxide at 0^oC. The specific surface area (SSA) was calculated according to the BET equation. The pore volume was estimated using the DFT method. Pristine sepiolite has shown the following value of SSA and CO₂ uptake at 0oC – 105 m²/g and 0.27 mmol/g, respectively. The highest value of these parameters was found for material obtained by KOH activation of mixture sepiolite and molasses (MSEP2) – 676 m²/g and 1.49 mmol/g. Sample MSEP2 also indicated the highest value of total pore volume and micropores volume with a diameter up to 0.8 nm.