Preparation and Its Excellent CO2/CH4/N2 Adsorption Selectivity of Novel Glucose-Based Adsorbents (C-GLC) with High BET Surface Area

Preparation and Its Excellent CO₂/CH₄/N₂ Adsorption Selectivity of Novel Glucose-based Adsorbents (C-GLC) with High BET Surface Area

Xingjie Wang, Binqin Yuan, Xin Zhou**, Qibin Xia, Zhong Li*

School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, PR China

*Corresponding author e-mail address: cezhli@scut.edu.cn

**Corresponding author e-mail address: xinzhou@scut.edu.cn

Abstract

In this work, we used starch sugar£¨e.g. glucose£©, a relatively inexpensive and renewable source, as carbon source to prepare glucose-based carbons (C-GLCs) materials with high specific surface area and pore volume. The resultant C-GLCs were characterized, and the CO₂/CH₄/N₂ adsorption isotherms of C-GLCs were measured at different temperatures separately. The isosteric heats of CO₂/CH₄/N₂ adsorption on the samples were estimated. IAST theory was also applied to predict the selectivity of the samples toward binary gas mixture. Results showed that BET area and pore volume of C-GLC-4 were up to 3153 m²/g and 2.056 cm³/g, respectively. C-GLCs possessed not only excellent stability, but also super-high CO₂ adsorption capacity up to 22.4 mmol/g at 30 bar, much higher than many metal-organic frameworks (MOFs). More importantly, C-GLC-4 possessed excellent adsorption selectivity toward CO₂/N₂ and CO₂/CH₄ binary mixtures, which increased with pressure. For CO₂/N₂ binary mixture, its IAST-predicted selectivity at 30 bar reached as high as 20 for CO₂/N₂ (0.5:0.5) mixture and 66 for CO₂/N₂ (0.15:0.85) mixture separately. For CO₂/CH₄ binary mixture, its IAST-predicted selectivity at 30 bar reached as high as 4.5 for CO₂/CH₄ (0.5:0.5) mixture and 27 for CO₂/CH₄ (0.1:0.9) mixture separately. The multiple cycles of CO₂ adsorption-desorption experiment showed that the C-GLC-4 has excellent regenerability. C-GLCs is a promising adsorbent for the separation of CO₂/N₂ and CO₂/CH₄ mixtures

Keywords: Glucose-based carbon, CO₂ adsorption, Isotherms, CO₂/CH₄/N₂ selectivity, Isosteric heats

Fig. 1 SEM images of C- GLCs	Fig. 2 CO2/CH4/N2 adsorption isotherms of C-GLC-4 at 298 K