One‐step purification of ethylene from acetylene and carbon dioxide by ultramicroporous carbons
Zhiwei Zhao, Yueyue Liu, Xing Liu, Yuan Liu, Jingwen Chen, Shixia Chen, Shuguang Deng, Jun Wang
Abstract
Abstract The one‐step adsorptive separation of high‐purity ethylene (C 2 H 4 ) from a ternary gas mixture (C 2 H 2 /C 2 H 4 /CO 2 ) is challenging and has not been reported on porous carbons. Herein, we report camphor seeds husk‐derived ultramicroporous carbons (CSHs) show high affinities toward acetylene (C 2 H 2 ) and carbon dioxide (CO 2 ) over C 2 H 4 . The optimized CSH‐2‐700 with high heteroatom contents and centered pore size distributions shows high C 2 H 2 adsorption capacity (2.24 mmol g −1 ) and record ideal adsorbed solution theory (IAST) C 2 H 2 /C 2 H 4 selectivity (10.2) among one‐step C 2 H 4 purification adsorbents. Meanwhile, CSH carbons are the only carbon adsorbents that preferentially adsorb CO 2 over C 2 H 4 , with a CO 2 /C 2 H 4 selectivity of 1.9 under ambient conditions. Furthermore, dynamic breakthrough experiments verified its feasibility for one‐step C 2 H 4 purification from a three‐component C 2 H 2 /C 2 H 4 /CO 2 gas‐mixture.