文摘
Ni-Based catalysts using mixed oxides of Al2O3鈥揝iO2, Al2O3鈥揟iO2, TiO2鈥揝iO2, and TiO2鈥揨rO2 as supports were evaluated for hydrotreatments using guaiacol as the model compound and characterized by N2 physical adsorption, X-ray diffraction (XRD), temperature-programmed desorption of ammonia (NH3-TPD), and temperature-programmed reduction of hydrogen (H2-TPR) techniques. The influence of the support, solvent, reaction temperature, and pressure on guaiacol conversion and product distributions were determined. Guaiacol conversion of 100% with cyclohexane selectivity of 86.4% was obtained over the Ni/TiO2鈥揨rO2 catalyst at the conditions of 300 掳C, 4.0 MPa H2 pressure, and decalin solvent. Furthermore, this system is also efficient for real bio-oil, where nearly 19.3% of the upgraded bio-oil yield was achieved under the optimal conditions determined for guaiacol. Gas chromatography鈥搈ass spectrometry (GC鈥揗S) analysis showed that the principal components were phenolic compounds, while the content of acids and aldehydes was negligible. The pH of bio-oil increased from 2.38 to 4.21, and the high heating value drastically increased from 13.1 to 25.8 MJ/kg.