Acid zeolites for glycerol etherification with ethyl alcohol: Catalytic activity and catalyst properties

[Display omitted] •An in-depth study of the influence of zeolite properties in the etherification of glycerol with ethyl alcohol was performed.•H-Beta and USY-650-L-2 zeolites showed the best glycerol conversions in the etherification with ethyl alcohol.•The hydrophobicity index of zeolites was measured and correlated with catalytic activity.•Lewis and Brønsted acid sites are active for glycerol and ethyl alcohol etherification through glycerol or ethanol adsorption. Platform molecules, such as glycerol, which is a by-product from biodiesel production, have been used to produce fuels and chemicals. A possibility to increase glycerol added value is through its transformation into ethers. In this work, the catalytic performance of USY, HZSM-5 and H-Beta zeolites was evaluated in the etherification of glycerol with tert-butyl and ethyl alcohols. The physicochemical and textural properties of these materials were characterized. For glycerol etherification, the best results were obtained for USY-650-L-2 (a Y zeolite submitted to two steaming cycles at 650°C followed by acid leaching) and H-Beta zeolites, which showed high conversions of glycerol up to 70% and were selective to mono- and disubstituted ethers, in both reactions. Hydrophobicity/hydrophilicity of the catalyst surface and reactants was crucial to glycerol conversion. Both Lewis and Brønsted acid sites were capable of catalyzing this reaction that can occur through the adsorption of glycerol or ethanol on active sites.