Today's chemical industry depends on fossil fuels, but this tendency must be reduced because of economical, social and environmental reasons. Biomass is regarded as an alternative source of chemicals. Lignin is a particularly interesting feedstock because of its low price, availability and rich chemical composition. When some thermal treatments (like pyrolysis) are applied to lignin lots of compounds are produced (mainly phenols). Guaiacol (2-methoxy phenols) is a well-known model compound of lignin pyrolysis vapours (also named tars ). The hydrogenation of lignin-based phenolic compounds into aromatic hydrocarbons (Benzene, Toluene, Xylene; named BTX) is considered economically attractive. The BTX mixture consumed by the industry today, is supplied by crude oils. Hydrogen is required to transform phenols in BTX and could be supplied by pyro-gasification of biomass (mixed with water CO, CO2 and CH4)