Catalytic Transfer Hydrogenolysis and Hydrogenation of Pyrolytic Lignin towards Green Chemicals and Biofuels – CaTHBio

The valorization of lignin into biofuels and high-value added chemicals offers a new avenue for decarbonation of chemical industry to tackle environmental concerns. The depolymerization of lignin by fast pyrolysis process leads to the production of a bio-oil rich in phenolic monomers. These molecules can be valorized using different hydrogenation and/or deoxygenation reactions requiring the supply of hydrogen. Catalytic Transfer Hydrogenolysis/Hydrogenation (CTH), usually performed in a closed reactor, is an environmentally-friendly approach which uses light organic molecules as a source of hydrogen. The objective of CaTHBio project is to enable the valorization of the vapors obtained from the pyrolysis of lignin by CTH process in continuous condition. For reach this goal, the project proposes (i) the design of original bifunctional catalysts based on transition metals (Ni and Fe) combined with oxophilics oxides (MoO3, ZrO2, Nb2O5), dispersed and stabilized on hierarchically porous support, (ii) catalytic investigation in a fixed bed reactor of the CTH reaction using phenolic molecules representative of lignin (guaiacol and vanillin) with molecules also obtained from biomass (ethanol, isopropanol and formic acid) as hydrogen donors. Particular attention will be devoted to understanding the reaction mechanism involved in hydrogen transfer reactions, in particular through kinetic studies combined with accompanying in situ infrared spectroscopy and the use of labeled molecules. Particular attention will be also done to the study of catalyst stability, more easily demonstrated by the type of reactor used.