In situ nitrogen enriched carbon for carbon dioxide capture

Abstract

In situ nitrogen enriched carbon was synthesized from locally available low cost soybean as the proteinaceous source. The material was synthesized by chemical activation using zinc chloride followed by physical activation using CO 2. The surface area of synthesized nitrogen enriched carbon was found to be 811 m 2/g which is comparable with commercially available activated carbon. The nitrogen enriched carbon was having a breakthrough adsorption capacity of 23 mg/g at 120 °C which was almost three times higher in comparison with the commercially available activated carbon for a gas mixture comprising 15% CO 2 balanced with helium. This high adsorption capacity was attributed to the presence of nitrogen group within the carbon matrix, which was estimated to be about 0.64% as determined using the Kjeldahl’s method. The presence of different nitrogen containing groups assisting the adsorption of CO 2 in the synthesized sample was also confirmed by infrared analysis. For checking the consistent performance of the synthesized carbon, multi-cycle adsorption–desorption studies were carried out at 30 and 75 °C in binary mixture of CO 2/N 2.