Integrated Production Of Bio-Jet Fuel Containing Lignin-derived Arenes Via Lipid Deoxygenation

With the development of the air transport industry,the consumption of aviation kerosene has increased year by year.As energy issues become more severe,there is an urgent need to develop new renewable energy sources?such as biomass feedstock?for the preparation of aviation kerosene.At present,the main problems in the preparation of aviation kerosene by biomass are the serious hydrogen consumption and the lack of aromatic components.We designed a new approach for one-pot production of bio-aviation jet fuel?containing arenes?from dehydro-aromatization of cycloalkanes?derived from lignin hydrodeoxygenation?and deoxygenation of lipid over Pt-Ir/Al₂O₃ in absence of hydrogen.We can obtain C₆-C₉ cycloalkane after catalytic hydrodeoxygenation of lignin.The cycloalkane is dehydrogenated and coupled with deoxidation of lipid to obtain aromatic hydrocarbon and aviation kerosene components.The exothermic?deoxygenation?-endothermic?dehydrogenation?reactions can be well balanced within the compatible working temperature ranges at around 400?.It is noted that the high concentrated CO produced from decarboxylation of fatty acids/esters tends to poison the metal center in the slurry-bed reactor,and meanwhile the coking olefin precursor formed from dehydrogenation of cyclic alkanes easily polymerizes into a polycyclic aromatics,both of which would deactivate the catalyst seriously.On the non-alloyed Pt-Ir/Al₂O₃ catalyst,the in-situ generated CO would be strongly adsorbed by Ir nanoparticles?as confirmed by Drifts IR of CO adsorption/desorption at different temperatures and DFT calculations?,and subsequently such CO would be hydrogenated to methane with hydrogen.Then on the reserved Pt nanoparticles,competitive adsorption of C₈ ethylcyclohexane and C₁₇ long-chain alkane?produced from pyrolysis of fatty acids?leads a bit slower dehydrogenation rate on ethylcyclohexane.In addition,the slight cracking on Al₂O₃ at 400? modifies the carbon chain numbers into the jet fuel range.The multi-functional nanoparticles of Pt and Ir as well as the Al₂O₃ support offers possibilities for constructing of high-grade jet fuel?containing arenes?from deoxygenation and dehydrogenation of lignin and lipid in an integrated process.