Adsorption of 5-Hydroxymethyl-Furfural (HMF) From Liquid Water/Dimethyl Sulfoxide (DMSO) Solutions Onto Hydrophobic Zeolites: An Experimental and Simulation Study

The adsorption of 5-hydroxymethylfurfural (HMF), dimethyl sulfoxide (DMSO), and water from binary and ternary mixtures in hydrophobic silicalite-1 and dealuminated Y (DAY) zeolites at ambient conditions was studied via experiments and molecular modeling. HMF and DMSO adsorption isotherms were measured and compared to those calculated using a combination of grand canonical Monte Carlo and expanded ensemble (GCMC-EE) simulations. A method based on GCMC-EE simulation for dilute solutions combined with the Redlich-Kister (RK) expansion (GCMC-EE-RK) is introduced to calculate the isotherms over a wide range of concentrations. The simulations, using literature force fields, are in reasonable agreement with the experimental data. In HMF/water binary mixtures, large pore hydrophobic zeolites are much more effective for HMF adsorption but less selective because large pores allow water adsorption due to H2O-HMF attraction. In HMF/DMSO/water ternary mixtures, the HMF loading decreases with increasing DMSO fraction, rendering separation of HMF from water/DMSO mixtures by adsorption difficult. We show that the ratio of the energetic interaction in the zeolite to the solvation free energy is a key factor in controlling separation from liquid mixtures. Overall, our findings could have an impact on the separation and catalytic conversion of HMF and the rational design of nanoporous adsorbents for liquid-phase separations in biomass processing.