Selective extraction of methane from C1/C2/C3 on moisture-resistant MIL-142A with interpenetrated networks

Abstract

The development of efficient technology for the purification of methane from natural gas becomes imperative for the industrial processes. We herein reported a Fe-MOF with interpenetrated networks, MIL-142A, further investigated its separation performances of C3H8/CH4 and C2H6/CH4. At 298 K, MIL-142A takes up 5.32 mmol/g C3H8 and 3.82 mmol/g C2H6, while its CH4 uptake is merely 0.54 mmol/g. Its C3H8/CH4 IAST-selectivity was high up to 1300 at 298 K, exceeding most reported MOF materials. Molecule simulation disclosed that the adjacent BTB3- ligands in interpenetrated networks collectively afford stronger adsorption affinity for propane by providing more van der Waals interactions, leading to the striking separation efficiency of C3H8/CH4. Moreover, MIL-142A shows good moisture stability even after exposure in the highly humid environment (RH 80%) for 7 days. Cyclic breakthrough tests further corroborated its commendable dynamic separation performance of CH4/C2H6/C3H8 mixtures and recyclability. Therefore, MIL-142A possesses the enormous potential to readily extract methane from C1/C2/C3 ternary gas mixtures.