Anthracite coal-derived activated carbon as an effectiveness adsorbent for superior gas adsorption and CO2 / N2 and CO2 / CH4 selectivity: Experimental and DFT study

Abstract

Here and in this research we synthesized and applied the anthracite coal derived activated carbon as an appropriate adsorbent for uptaking CO2, N2 and CH4. With alteration of different parameters such as activation time, the temperature and KOH /anthracite mass ratio, we synthesized several adsorbents based on anthracite. The synthesized adsorbents created a huge surface area (up to 4012 m2/g) with total pore volume (up to 2.07 cm3/g) and pore diameter (up to 3.56 nm). According to the results Iranian anthracite based activated carbon (IACAC) adsorbents within the low and high pressure range (1–35 bar) and at the temperature of 25 °C enhanced CO2 uptake up to 10.51 mmol/g and 27.58 mmol/g, respectively, highlighting a highly functionality of adsorbent in uptaking CO2. Our results also demonstrated that the synthesized adsorbents provided an enhanced CO2 and CH4 uptake within the high and low pressure range. The synthesized adsorbents provided a remarkable selectivity for CO2/N2 (25.67) and CO2/CH4 (10.17), suggesting a high performance and functionality of adsorbents in gas separating. The density functional theory (DFT) calculations was also evaluated and analyzed in order to understand the binding energetic and adsorption mechanism. These findings demonstrated that the anthracite coal derived activated carbon possessing a huge surface area and excellent features could contribute to an enhanced gas uptake in large scale.