Highly Efficient Separation of CH4/C2H6/C3H8 from Natural Gas on a Novel Copper-Based Metal–Organic Framework

• Published in: Industrial & engineering chemistry research Vol. 62; no. 12; pp. 5252 - 5261
• Main Authors: Lin, Danxia, Tu, Shi, Yu, Liang, Yuan, Yinuo, Wu, Ying, Zhou, Xin, Li, Zhong, Xia, Qibin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 29.03.2023
• Subjects: Separations
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.2c04286

The separation of light hydrocarbons like methane, ethane, and propane is an important section of the chemical industry. Herein, we reported a novel porous metal–organic framework (MOF) Cu-IPA and investigated its CH4/C2H6/C3H8 separation performance, particularly for efficient capture of C2H6 and C3H8 at low concentrations. Cu-IPA featured 1D hexagonal channels and triangular channels decorated with extensive oxygen atoms. It showed high C2H6 and C3H8 capacities in the low-pressure region, where C3H8 uptake at 5 kPa was 1.62 mmol/g and C2H6 uptake reached 1.33 mmol/g at 10 kPa, suggesting the strong adsorption affinities toward C2H6 and C3H8. For an equimolar C2H6/CH4 mixture, Cu-IPA exhibited a considerable IAST selectivity of 40, exceeding most reported MOF adsorbents. Excellent CH4/C2H6/C3H8 separation performance for Cu-IPA can be attributed to its appropriate pore size and abundant accessible oxygens atoms in the triangular channel. The molecular simulation revealed that Cu-IPA tended to form stronger C–H···O interactions with C2H6 and C3H8 due to the higher polarizabilities, resulting in larger interaction differences between C2H6/CH4 and C3H8/CH4. Breakthrough tests also supported the excellent dynamic separation performance and recyclability of Cu-IPA.