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PP-III-18Figure 1. Influence of temperature on phenolconversion with Ni-based catalysts.Figure 2. Influence of temperature onproducts selectivity with Ni-based catalysts.For the catalysts studied the products with the highest selectivity wascyclohexanol at low temperatures and cyclohexane at high temperatures (Figure 2).The most important products were cyclohexanol, cyclohexane and benzene. This factindicates a unique reaction pathway in the HDO of the phenol, which is thehydrogenation-hydrogenolysis. First hydrogenation took place converting phenol intocyclohexanol, especially at low temperatures. Then, hydrogenolysis occurred throughthe breakage of the oxygen-carbon bond and finally a subsequent hydrogenationconverted the cyclohexanol into cyclohexane. It is noteworthy that at hightemperature (573 K) and a WHSV of 0.5 h –1 , in the catalysts supported with ceriashowed the direct hydrogenolysis contribution started and benzene as productappeared. Also at the highest temperature methylcyclopentane was also formed fromcyclohexane isomerization.ConclusionsThe main conclusions of this research are: i) Ni-based catalysts are verypromising in biomass derived liquids HDO; ii) for the Ni-based catalysts the phenolconversion is very high and it seems that the preference route of reactions is thehydrogenation-hydrogenolysis; iii) with these catalytic systems alicyclic products areformed and the corresponding alicyclic alcohols appear as short-lived intermediatesspecially at low temperatures; iv) the stability in these catalysts seems to be quiethigh although a small deactivation was found where Al 2 O 3 was used as support.References[1]. E. Furimsky, Appl. Catal., A 199 (2000), 147-190.[2]. Viljava T.R., Doctoral Thesis, Helsinki University of Technology, Espoo, Finland, 2001.[3]. I. Gandarias, V.L. Barrio, J. Requies, P.L. Arias, J.F. Cambra, M.B. Güemez. Int. J. HydrogenEnergy 33(13) (2008) 3485-3488.AcknowledgementsThe authors thank financial support from the MICINN (project HIREUS) and the BasqueAutonomous Government.473