Efficient adsorption separation of xylene isomers using a facilely fabricated cyclodextrin-based metal-organic framework

BackgroundMetal-organic frameworks (MOFs) are energy-efficient adsorbents for separating industrial chemical feedstocks. A type of MOF containing an extended porous network of -cyclodextrin (-CD) and alkali metal salts, CD-MOF, has potential applications in adsorption separation processes in the petrochemical industry. This study aims to present the adsorption efficiency of CD-MOF-1 in separating xylene regioisomers. ResultsThe adsorption separation of xylene regioisomers on layered CD-MOF-1 microcrystals was studied using batch vapor-phase adsorption and liquid-phase breakthrough adsorption. CD-MOF-1 showed preferable adsorption of o-xylene over the other two isomers, with adsorption strength in the order o-xylene (oX)>m-xylene (mX)>p-xylene (pX). With increased temperature, high adsorption capacities of oX and mX over pX were detected. However, this also resulted in a decrease of the separation factors of oX/pX and mX/pX. ConclusionThe high resolution and large separation factors for oX/pX and mX/pX make CD-MOF-1 an efficient and reliable alternative adsorbent to the isolation protocols for xylene isomers currently used in the petrochemical industry. (c) 2018 Society of Chemical Industry