Adsorptive Separation of Furfural/5-Hydroxymethylfurfural in MAF-5 with Ellipsoidal Pores

Abstract

The objective of this work is to study the adsorptive separation of the biomass-derived furfural (Fur) and 5-hydroxymethylfurfural (5-HMF). Because Fur and 5-HMF have similar ellipsoidal shapes, the diffusion of the larger 5-HMF may be blocked by the elliptical window of adsorbents. Thus, two zeolitic imidazolate framework (ZIF) materials with the identical chemical composition, MAF-6 and MAF-5, were used as spherical and ellipsoidal pore adsorbents, respectively. In the dynamic column adsorption of a binary-component system (Fur/5-HMF, 5/5 wt %) in an aqueous solution, the adsorption amounts of Fur on MAF-6 display a 13% decrease compared with the single-component system, whereas the adsorption amounts of Fur on MAF-5 are identical to those obtained in the single-component system and the amounts of adsorbed 5-HMF are almost negligible. Thus, the Fur/5-HMF selectivity is only 6.4 for MAF-6, whereas the selectivity reached 115.8 for MAF-5. The results show that the narrow elliptical window/ellipsoidal tile of MAF-5 enhanced separation selectivity compared with the larger circular window/spherical cage of MAF-6. In addition, the general rate model and density functional theory calculations further verify that the elliptical window of MAF-5 exhibits a strong mass-transfer barrier that must be overcome for the diffusion of the larger 5-HMF molecules.

Confinement effect and efficient adsorption of furfural onto ZIF‐8‐derived microporous carbon

“…The adsorption selectivity ( S ) of component i was calculated by Eqn (2). 17 …”

“…Zeolitic imidazolate frameworks (ZIFs)-derived porous carbon (C) materials are highly promising candidates when compared to previously reported adsorbents, including activated C, [6][7][8][9][10] polymers [11][12][13] and ZIFs. [14][15][16][17] The excellent adsorption behavior lies in the tunable surface chemistry/pore structure of C and its π-π interactions with furfural. 18 Our recent study demonstrated that furfural adsorption is closely related to the hydrophobicity, electrostatic interactions and π-π interactions of the adsorbent.…”

“…Zeolitic imidazolate frameworks (ZIFs)‐derived porous carbon (C) materials are highly promising candidates when compared to previously reported adsorbents, including activated C, 6‐10 polymers 11‐13 and ZIFs 14‐17 . The excellent adsorption behavior lies in the tunable surface chemistry/pore structure of C and its π–π interactions with furfural 18 .…”

Recent Progress of Adsorptive Ultrafiltration Membranes in Water Treatment—A Mini Review

“…Adsorbents are promising materials for capturing pollutants, such as low-molecular organics and heavy metal ions, because of their abundant sorption sites, large surface area, and fast adsorption kinetics [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. However, adsorbents are usually synthesized in the form of powders, which give rise to some problems in the separation and regeneration processes [ 15 , 16 ] and potential safety issues may occur due to leaching into water bodies [ 17 , 18 , 19 ].…”

Adsorption of 5-Hydroxymethylfurfural, Levulinic Acid, Formic Acid, and Glucose Using Polymeric Resins Modified with Different Functional Groups

“…However, 5-HMF can be further rehydrated into byproducts under acidic conditions, such as LA, FA, and humins, , which results in great difficulty to separate and purify 5-HMF from such diluted and complex multicomponent systems . In the last two decades, considerable efforts have been devoted to the selection and optimization of the catalyst systems to enhance C6 sugar conversion as well as 5-HMF yields. − However, only a few investigations have been focusing on the separation of 5-HMF from such dilute aqueous solutions or hydrolysates. − Separation and recovery of 5-HMF by distillation not only requires high energy consumption but also leads to a great risk of polymerization of 5-HMF due to instability at high temperature. Vinke and Bekkum first presented selectively recovered 5-HMF from aqueous mixtures with fructose and LA using three activated carbons in terms of R0.8 A, ROX 0.8, and C-granular.…”