A pillared-layer metal–organic framework for efficient separation of C3H8/C2H6/CH4 in natural gas

Abstract

Metal-organic frameworks (MOFs) have great potentials as adsorbents for natural gas purification. However, the trade-off between selectivity and adsorption capacity remains a challenge. Herein, we report a pillared-layer metal-organic framework Ni(HBTC)(bipy) for efficiently separating the C 3 H 8 /C 2 H 6 /CH 4 mixture. The experimental results show that the adsorption capacity of C 3 H 8 and C 2 H 6 on Ni(HBTC)(bipy) are as high as 6.18 and 5.85 mmol·g −1 , while only 0.93 mmol·g −1 for CH 4 at 298 K and 100 kPa. Especially, the adsorption capacity of C 3 H 8 at 5 kPa can reach an unprecedented 4.52 mmol·g −1 and for C 2 H 6 it is 1.48 mmol·g −1 at 10 kPa. The ideal adsorbed solution theory predicted C 3 H 8 /CH 4 selectivity is as high as 1857.0, superior to most of the reported materials. Breakthrough experiment results indicated that material could completely separate the C 3 H 8 /C 2 H 6 /CH 4 mixture. Therefore, Ni(HBTC)(bipy) is a promising material for separation of natural gas.