Novel glucose-based adsorbents (Glc-Cs) with high CO2 capacity and excellent CO2/CH4/N2 adsorption selectivity

Abstract We reported novel glucose-based carbon materials (Glc-Cs) with high surface area, high CO 2 adsorption capacity and excellent CO 2 /CH 4 /N 2 selectivity. Starch sugar (glucose) was used as carbon source to prepare Glc-Cs, and then the resultant samples were characterized by N 2 adsorption at 77 K, FTIR, TGA and SEM. CO 2 /CH 4 /N 2 adsorption isotherms of Glc-Cs were separately measured and the isosteric heats of CO 2 /CH 4 /N 2 adsorption on the samples were estimated. IAST theory was applied to predict the selectivity of the samples toward binary gas mixtures. The regenerability of the resultant materials was evaluated by means of experiments of CO 2 adsorption-desorption cycles. Results showed that BET surface area and pore volume of the resultant Glc-Cs reached as high as 3153 m 2 /g and 2.056 cm 3 /g, respectively. Glc-Cs possessed not only excellent stability, but also super-high CO 2 adsorption capacity up to 22.4 mmol/g at 30 bar, comparable or superior to many stable metal-organic frameworks (MOFs). Besides, Glc-Cs possessed excellent adsorption selectivity toward CO 2 /N 2 and CO 2 /CH 4 binary mixtures. For example, for CO 2 /N 2 binary mixture, its IAST-predicted selectivity at 30 bar reached as high as 20 toward CO 2 /N 2 (0.5:0.5) mixture and 66 toward CO 2 /N 2 (0.15:0.85) mixture separately. For CO 2 /CH 4 binary mixture, its IAST-predicted selectivity at 30 bar reached as high as 4.5 for CO 2 /CH 4 (0.5:0.5) mixture and 27 for CO 2 /CH 4 (0.1:0.9) mixture separately. Experiment of multiple cycles of CO 2 adsorption-desorption showed that the Glc-Cs has excellent regenerability. CO 2 desorption efficiency reached about 97–98%. Glc-Cs is a promising adsorbent for the separation of CO 2 /N 2 and CO 2 /CH 4 mixtures.