Ni–Cu Bimetallic Catalytic System for Producing 5-Hydroxymethylfurfural-Derived Value-Added Biofuels
Nerea Viar, Jesús Requies, Ion Agirre, A. Iriondo, Miryam Gil-Calvo, P.L. Arias
Abstract
Biomass is the only renewable carbon source capable of replacing conventional production of chemicals and fuels derived from nonrenewable resources. The cellulose monomers derived from lignocellulosic biomass can be transformed into 5-hydroxymethylfurfural (HMF), which can be further converted into 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF). These products can be used as substitutes for standard gasoline or as additives. This study has shown that by using Ni–Cu catalysts supported on ZrO2, DMF can be obtained with a yield of 70% after 25 h on stream. Experiments were carried out in a continuous fixed-bed reactor, and complete HMF conversion was achieved by the formation of Ni–Cu species. The importance of Ni active sites in the hydrogenation of DMF to obtain DMTHF was shown, observing how the progressive Ni oxidation phenomenon during the reaction favors DMF production to the detriment of DMTHF. Catalyst evolution was corroborated by different characterization techniques after carrying out several experiments with different durations.