CO2 adsorption on oxygen enriched nanostructured carbons derived from silica templated resorcinol-formaldehyde

Abstract

Carbon dioxide capture needs development of cost effective CO2 capture technologies. This paper describes oxygen enriched nanostructured carbons synthesized from nanocasting technique using mesoporous silica as template and resorcinol-formaldehyde as precursor. Carbonization at various temperatures (600°C–800°C) was carried out to develop range of carbon adsorbents. Thorough characterization of textural, surface and chemical properties was carried out on prepared carbons and evaluated for CO2 capture performance using thermogravimetric analyser under dynamic conditions. Highest dynamic CO2 uptake capacity was reported to be 1.5mmolg−1 by SRF-700 at 30°C in 100% pure CO2. The CO2 uptake performance of the prepared carbons is affected by both the textural properties and surface chemistry. Four adsorption–desorption cycles established the material with complete stability and regenerability. Fractional order kinetic model completely described CO2 adsorption on prepared carbons. Thermodynamic parameter values suggested spontaneous, random and exothermic nature of the process. Energetically heterogeneous surface of adsorbent was confirmed by best fitting of Temkin isotherm and random pattern of isosteric heat of adsorption with surface coverage. Approximately, 1.82MJ per kg CO2 thermal energy is required for desorption process.