The conversion of biomass-derived monosaccharides to value-added platform compounds, regarded as the alternative biofuels precursors, has attracted increasing attention. This work provides a novel approach on developing efficient and recyclable catalyst for biorefining. Herein, a titania-supported tungstophosphoric acid (TPA-TiO2) nanocomposite catalyst with advantages in acidity flexibility and catalytic stability was proposed for the efficient dehydration of xylose to furfural. The loading of the active component of TPA played an important role in the acidity and Lewis/Brønsted acids distribution of the catalyst. The structure characterization of the catalyst showed that the TPA particles were distributed well in TiO2 support. After the optimization of catalytic reaction conditions, the xylose conversion could approach to 96.12% while the furfural yield of 76.71% was obtained at 190 °C for 60 min catalyzed by TiO2-TPA-3 in a methyl isobutyl ketone (MIBK)–water biphasic solvent system. It was still about 80% of the initial yield after the fifth recycling of the TiO2-supported heteropolyacids catalyst. Furthermore, the reaction kinetics of xylose dehydration to furfural was investigated. The catalytic system in this work had a lower activation energy for xylose dehydration, and the decrease in furfural yield was mainly caused by the side reaction of furfural with intermediates. This work provides a novel approach on developing efficient and recyclable catalyst for biorefining.

Alkali lignin, which is derived from the pulping and paper-making process, has been recognized to have great potential in the preparation of chemicals and value-added renewable biofuels. In this report, saturated steam was applied simultaneously, a novelty procedure, to assist in lower-temperature pyrolysis (from 275 to 350 °C) of alkali lignin and selective production of guaiacol components in a fixed-bed reactor. The results indicated that the lower-temperature pyrolysis displayed a positive effect on the breaking of aliphatic C–O bonds of lignin (β-O-4 bond) and helped to increase the intensity of oxygenated aromatic carbons and aromatic CC structures. The guaiacol components were successfully removed from alkali lignin and extracted by saturated steam. This method displayed a useful effect on pyrolysis of lignin and on higher selectivity of guaiacol components. A relatively higher yield of stable solid carbon (from 68.45 to 88.67 wt %) and relative selectivity of guaiacol components (from 79 to 90.7%) were obtained. This novel method is quite a promising technique for simultaneous pretreatment of lignin and selective production of guaiacol components.