Cu-TDPAT, an rht-Type Dual-Functional Metal–Organic Framework Offering Significant Potential for Use in H2 and Natural Gas Purification Processes Operating at High Pressures

Abstract

The separations of CO2/CO/CH4/H2, CO2/H2, CH4/H2, and CO2/CH4 mixtures at pressures ranging to 7 MPa are important in a variety of contexts, including H2 production, natural gas purification, and fuel-gas processing. The primary objective of this study is to demonstrate the selective adsorption potential of an rht-type metal–organic framework [Cu3(TDPAT)(H2O)3]·10H2O·5DMA (Cu-TDPAT), possessing a high density of both open metal sites and Lewis basic sites. Experimental high pressure pure component isotherm data for CO2, CO, CH4, and H2 are combined with the Ideal Adsorbed Solution Theory (IAST) for estimation of mixture adsorption equilibrium. The separation performance of Cu-TDPAT is compared with four other microporous materials, specifically chosen in order to span a wide range of physicochemical characteristics: MgMOF-74, MIL-101, LTA-5A, and NaX. For all mixtures investigated, the capacity of Cu-TDPAT to produce the desired product, H2 or CH4, satisfying stringent purity requirements, in a fixed bed ...