Ranking of Metal–Organic Frameworks (MOFs) for Separation of Hexane Isomers by Selective Adsorption

Abstract

The work presented in this article is aimed to assess the performances of 4763 Metal−Organic Frameworks (MOFs) for separation of hexane isomers using computer simulation methods. These MOFs, taken from the Computational Ready Experimental (CoRE) MOF database, are ranked on the basis of various performance metrics, namely, adsorption selectivity, working capacity, and regenerability. We investigated six binary mixtures, one three-component equimolar mixture, and one five-component equimolar mixture of hexane isomers at temperatures of 383, 433, 483, and 533 K. The MOFs were ranked separately for separation of each of these mixtures. The rankings with respect to these three metrics were found to be mostly different with only a few MOFs in common. We also carried out the rankings at different temperatures close to the typical isomerization reactor temperature. It is observed that the orders of the rankings at different temperatures are different. However, the majority of the MOFs are found to be common in the rankings at different temperatures. MOFs BIMDOR and WAMRIN01 perform the best with high adsorption selectivity for all the mixtures. It is observed that the MOFs with very high adsorption selectivity do not have high working capacity and regenerability. However, MOFs VEHJOJ, VEHJUP, and NAYGUR are found to be potential candidates for practical application of separation of the hexane isomers as they have regenerability >80% and reasonably high working capacity and adsorption selectivity. Further, we looked at various structures' property correlations. These correlations reveal that the largest cavity diameter and pore volume are crucial structural properties to be adjusted for obtaining the best performing MOF structure with high selectivity, high working capacity, and high regenerability. MOFs with a largest cavity diameter close to 10 Å show high values of selectivity, working capacity, and regenerability.

High-Throughput Computational Screening of Metal–Organic Frameworks for the Separation of Methane from Ethane and Propane

“…The separation performances of the MOFs were assessed using four metricsadsorption selectivity, working capacity, regenerability, and adsorbent performance score (APS). Adsorption selectivity for a binary mixture is defined as 33,44 S q q f f / / ads 1 2…”

“…The separation performances of the MOFs were assessed using four metricsadsorption selectivity, working capacity, regenerability, and adsorbent performance score (APS). Adsorption selectivity for a binary mixture is defined as , where, q i is the loading and f i is the fugacity of the i th component. Working capacity ( C w ) is defined as the adsorption capacity of a MOF at the adsorption pressure (i.e., 1 bar in our case) minus the adsorption capacity at the desorption pressure (i.e., 0.1 bar in our case).…”

“…Adsorption selectivity for a binary mixture is defined as , where, q i is the loading and f i is the fugacity of the i th component. Working capacity ( C w ) is defined as the adsorption capacity of a MOF at the adsorption pressure (i.e., 1 bar in our case) minus the adsorption capacity at the desorption pressure (i.e., 0.1 bar in our case). For an adsorbent to be practically deployable in an adsorption–desorption-based cyclic separation system such as pressure swing adsorption, the regeneration of the adsorption sites during the desorption is very crucial for the reuse of the adsorbent.…”

“…The advent of the modern technology in high-performance computing can be handy to carry out such a screening. In the past, researchers have employed such high-throughput computational screening of various porous materials to identify the best candidate for a given application of interest. − In this article, we present a high-throughput screening of around 12,000 MOF structures adopted from the Computational Ready Experimental (CoRE) MOF database developed by Chung et al to screen out the best material that can separate methane from ethane and propane at ambient conditions. We have screened these MOFs for the separation of two equimolar binary mixturesethane/methane (50% ethane and 50% methane) and propane/methane (50% propane and 50% methane), and two ternary mixturesequimolar (33.33% methane, 33.33% ethane, and 33.33% propane) and 90:7:3 (90% methane, 7% ethane, and 3% propane).…”

Hexane isomers separation on an isoreticular series of microporous Zr carboxylate metal organic frameworks

“…[31][32][33][34][35] Regarding the separation of hexane isomers, several MOFs have been considered to date. [36][37][38][39][40][41][42][43][44][45][46] For instance ZIF-8, featuring a sodalite zeolite type structure, can completely remove nhexane from branched isomers with higher adsorption capacity than zeolite 5A. [40][41][42] Fe 2 (BDP) 3 , consisting in a framework of onedimensional triangular channels that can accommodate all hexane isomers, separates them by the degree of branching.…”