One‐step purification of ethylene from acetylene and carbon dioxide by ultramicroporous carbons

Abstract

AbstractThe one‐step adsorptive separation of high‐purity ethylene (C2H4) from a ternary gas mixture (C2H2/C2H4/CO2) 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 (C2H2) and carbon dioxide (CO2) over C2H4. The optimized CSH‐2‐700 with high heteroatom contents and centered pore size distributions shows high C2H2 adsorption capacity (2.24 mmol g−1) and record ideal adsorbed solution theory (IAST) C2H2/C2H4 selectivity (10.2) among one‐step C2H4 purification adsorbents. Meanwhile, CSH carbons are the only carbon adsorbents that preferentially adsorb CO2 over C2H4, with a CO2/C2H4 selectivity of 1.9 under ambient conditions. Furthermore, dynamic breakthrough experiments verified its feasibility for one‐step C2H4 purification from a three‐component C2H2/C2H4/CO2 gas‐mixture.