Selective Adsorption of C2+ Alkanes over Methane by Using a Zinc Tris-Pyrazolate Framework

Abstract

The upgrading of natural gas is an essential step before its further utilization, wherein the recovery of C2+ alkanes (ethane, propane, and n-butane) is of economic interest. The adsorptive separation based on metal-organic frameworks (MOFs) has attracted intensive attentions for separating these light hydrocarbons. In this study, we have utilized a zinc tris-pyrazolate MOF, MAF-68, for efficient capture of C2+ alkanes from methane. At 298 K and 5 kPa, MAF-68 exhibits remarkably high uptakes for n-C4H10 (5.08 mmol g-1) and C3H8 (3.01 mmol g-1), which are 84.9% and 48.1% of their maximum adsorption capacities, respectively. Subsequently, the adsorptive selectivities for n-C4H10/CH4 and C3H8/CH4 are 804 and 121, respectively. Breakthrough experiments validate the application potential of MAF-68 for energy-efficient alkanes separation.