Adsorption of Biomass-Derived Polyols onto Metal–Organic Frameworks from Aqueous Solutions

Adsorption of biomass-derived polyols from dilute aqueous solutions as an alternative to energy-intensive distillation has a significant impact on the economics of biorefinery. A series of metal–organic frameworks (MOFs) which differ in chemical functionality and topology (SOD and RHO) are screened as adsorbents in this study. It has been demonstrated that SIM-1 (Zn(almeIm)2, SOD topology, almeIm = 4-methylimidazole-5-carbaldehyde) outperforms other studied MOFs, namely ZIF-8, ZIF-90, ZIF-93, and ZIF-97, in terms of the adsorption capacity. The hydrophobic/hydrophilic balance and aperture/pore size of adsorbents are two key factors controlling the adsorption capacity. The adsorption of C2–C3 polyols onto SIM-1 increased in the order of glycerol < ethylene glycol < 1,3-propanediol, which has a positive correlation with their octanol–water partition coefficients (Kow). In addition, SIM-1 exhibited preferential adsorption of 1,3-propanediol over glycerol, indicating the promising application of SIM-1 as adsorbent in the fermentation process of glycerol to 1,3-propanediol.