Selective organic phase hydrodeoxygenation of typical phenolic monomers and two lignin oils over highly active Pd/Hβ catalyst for high-grade bio-fuel production

Abstract

The selective hydrodeoxygenation (HDO) of lignin-derived bio-oil still meets the great challenges due to its complex oxygenated organic component. In this research, first time, Pd-based zeolite catalysts were prepared by the modified deposition-precipitation (DP) method for the HDO conversion of guaiacol. Notably, for the same Si/Al ratio of zeolite, Pd2%/Hβ catalyst showed the higher catalytic activity on the HDO of guaiacol than that Pd2%/M and Pd2%/HZSM-5 catalyst, which mainly originated from the synergetic effect between metal nanoparticles size and acid sites of catalyst. As one of typical phenolic monomers, guaiacol can be converted into high yield of hydrocarbons under the condition of 220 °C, 3 MPa H2, and 4 h in n-hexane over Pd2%/Hβ (DP) catalyst. This highly active catalyst exhibited the good recyclability in the HDO conversion of guaiacol. In addition, other typical phenolic monomers can be converted into high yield of hydrocarbons over this highly active catalyst. Considering this, after HDO upgrading, real lignin oil (RLO) can be converted into high yield of hydrocarbons with the carbon number (CN) in range of C7-C15. This work highlighted that the depolymerization monomers from lignin can be further upgraded by this high active catalyst through HDO to obtain jet hydrocarbons fuel.