Silica-Supported Ni₂P Catalysts For Liquid Phase Hydrodeoxygenation Of Guaiacol

With the dwindling of fossil fuels and the increase of greenhouse effect, combined with political and environmental concerns about clean energies, it is imperative to develop economical and energy-efficient processes for the sustainable production of fuels. Biomass widely existed in the world, and can be directly converted into liquid fuels, so is a preferable alternative to fossil fuels. Biomass pyrolysis oil is different from the traditional fuel, and its high oxygen content, causing it can not be directly used to launch the system, so the pyrolysis oil must be for further processing. The motheds of upgrading bio-oil contain hydrodeoxygenation (HDO), catalytic cracking and aqueous phase reforming. HDO has been widely used for upgrading the bio-oils as the most promising method.In this thesis, a series of silica supported M2P catalysts with different Ni/P molar ratios (2.0-0.5) and different total loadings of Ni2P/SiO2catalysts at Ni/P molar ratio of1.0were prepared by H2plasma reduction method in the dielectric barrier discharge (DBD) reactor and characterized by XRD and N2adsorption. Their catalytic activities were evaluated in the hydrodeoxygenation of guaiacol in the fixed bed reactor. The catalyst with Ni/P molar ratio of1.0and total loading of30wt%showed the highest HDO performance. At260℃and4.0MPa, the conversion of guaiacol reached100%and the only product was cyclohexane.Futher, the effect of solvents on the HDO activity of Ni2P/Si02catalysts were investigated as well. At300℃and4.0MPa, the order of guaiacol conversion is n-dodedane-decalin<tetralin. In the solvents of decalin and tetralin, the conversion of guaiacol and selevtivity of products changed greatly with the diversification of hydrogen pressure. However, in the solvent of n-dodedane, the conversion of guaiacol and selevtivity of products showed no obvious diversification to hydrogen pressure. The reaction temperature is also an important factor on the HDO activity of Ni2P/Si02catalysts. In the range of180-260℃, the conversion of guaiacol increases with increasing temperature. When the reaction temperature is higher than260℃, guaiacol conversion was100%.