Separating Xylene Isomers with a Calcium Metal-Organic Framework

Angew Chem Int Ed Engl. 2023 Oct 9;62(41):e202310672. doi: 10.1002/anie.202310672. Epub 2023 Aug 17.

Abstract

The purification of p-xylene (pX) from its xylene isomers represents a challenging but important industrial process. Herein, we report the efficient separation of pX from its ortho- and meta- isomers by a microporous calcium-based metal-organic framework material (HIAM-203) with a flexible skeleton. At 30 °C, all three isomers are accommodated but the adsorption kinetics of o-xylene (oX) and m-xylene (mX) are substantially slower than that of pX, and at an elevated temperature of 120 °C, oX and mX are fully excluded while pX can be adsorbed. Multicomponent column breakthrough measurements and vapor-phase/liquid-phase adsorption experiments have demonstrated the capability of HIAM-203 for efficient separation of xylene isomers. Ab initio calculations have provided useful information for understanding the adsorption mechanism.

Keywords: Adsorptive Separation; Metal-Organic Frameworks; Size-Exclusion; Xylene Isomers.