Ultramicroporous carbon granules with narrow pore size distribution for efficient CH 4 separation from coal‐bed gases

• Published in: AIChE journal 2021-09, Vol.67 (9)
• Main Authors: Dong, Ze, Li, Bei, Shang, Hua, Zhang, Peixin, Chen, Shixia, Yang, Jiangfeng, Zeng, Zheling, Wang, Jun, Deng, Shuguang
• Format: Article
• Language: English
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.17281

The adsorptive separation of CH 4 from low‐grade coal‐bed gas can be performed at decentralized and remote coal mines, and it uses more energy‐ and is cost‐efficient than the traditional cryogenic distillation process. Herein, we present a facile method to prepare ultramicroporous carbon granules with a narrow pore‐size distribution at 0.5–0.6 nm. To our knowledge, such centered and uniform pore‐size distribution in carbon granules has never been reported. The carbon granules can be directly utilized in adsorption columns without a granulation or pelletization process. The granular oil‐tea‐shell‐derived porous carbon (GOC‐2) exhibited a record‐high CH 4 uptake of 1.82 mmol/g and CH 4 /N 2 selectivity of 5.8 at 1.0 bar and 298 K among carbon granules. The excellent CH 4 /N 2 separation performances were confirmed from the results of dynamic breakthrough experiments and pressure swing adsorption simulations. This work provides a novel strategy for developing ultramicroporous carbon granules and guides the future design of efficient CH 4 /N 2 separation adsorbents.