A Robust Ca-Based Microporous Metal–Organic Framework for Thermodynamic Separation of Hexane Isomers

Abstract

Adsorptive separation of alkane isomers, especially the efficient separation of mono-and dibranched alkanes, remains challenging in the petrochemical industry. We report here the discrimination of alkane isomers through a thermodynamically driven mechanism by a highly stable calcium-based metal−organic framework. This newly developed 3D structure is built on a tetracarboxylate linker, featuring 1D channels with optimal pore dimensions to discriminate alkane isomers.

Metal‐Organic Frameworks for C6 Alkane Separation

“…HIAM-202: reproduced with permission. [32] Copyright 2022, American Chemical Society. CAU-10-H/Br: reproduced with permission.…”

“…Copyright 2018, Springer Nature. HIAM‐202: reproduced with permission [32] . Copyright 2022, American Chemical Society.…”

Nonlinear 3D Ligand-Based Metal–Organic Framework for Thermodynamic–Kinetic Synergistic Splitting of Mono-/Dibranched Hexane Isomers

“…Metal–organic frameworks (MOFs) are well-known porous materials for their exceptional structural diversity and tunability, a property derived from their modular construction. − This unique feature makes them very promising for the separation of hexane isomers, particularly for achieving improved separation performance between mono- and dibranched hexane isomers compared to traditional molecular sieves. − While some reported MOFs exploit the thermodynamic affinity difference of isomers to separate 3MP from 22DMB, their separation selectivities are generally restricted due to the ability of both isomer molecules to enter the pore channels, and it is difficult to realize a dynamic exclusion of 22DMB from 3MP during fixed-bed separation processes, resulting in inadequate yields of pure 22DMB. − Kinetic separation mechanism employs differences in the diffusion rates of isomers within pore channels to distinguish 3MP/22DMB, , and a dynamic exclusion of 22DMB from 3MP can be achieved in the fixed-bed process when 22DMB has a slow diffusion in the adsorbent (e.g., MIL-53­(Fe)-(CF 3 ) 2 ) . However, a significant challenge existing in such adsorbents is that most of them have relatively insufficient 3MP affinity and a 3MP/22DMB affinity difference, leading to limited 3MP capacity and 22DMB productivity.…”