Study Of Synthesis Of High Density Jet Fuel Range Alkanes From Lignocellulose Derivatives

Liquid jet fuel is an important aerospace fuel,which provides propulsion energy for aerospace vehicle.The density of jet fuel is one of the key determinants of the aircraft performance.In order to reduce the dependency on fossil resources,the conversion of renewable biomass resources to high density jet fuel has gradually become an important research object.In this work,high density jet fuel range cycloalkanes were synthesized from lignocellulose platform compounds by the alkylation reaction of phenol with benzyl acetate and aldol condensation of cyclopentanone with 2-methylbenzaldehyde,followed by the hydrodeoxygenation of condensation products.The main contents in this work are as follows:(1)The alkylation reaction was investigated when phenol and benzyl acetate were used as feedstocks.Montmorillonite(MMT)catalyst was found to be most active for the alkylation reaction of phenol with benzyl acetate.The yield of the alkylation reaction products 2-benzylphenol and 4-benzylphenol achieved up to 70% under the conditions of reaction temperature 140°C and reaction time 2 h.The Lewis acid sites of montmorillonite catalyst could promote the formation of benzyl carbocation.The alkylation products were hydrodeoxygenated on Pd/C catalyst.Besides dicyclohexylmethane,a high proportion of perfluorene was obtained through intramolecular alkylation reaction.The density and heating value of hydrodeoxygenation(HDO)products were 0.956 g/m L and 38.9 MJ/L respectively,which can be used as high density jet fuel component or additive.(2)The solvent-free aldol condensation reaction was investigated when cyclopentanone and 2-methylbenzaldehyde were used as feedstocks.The highest yield of products(62.99%)was obtained when calcium oxide(Ca O)acted on the solvent-free aldol condensation reaction of cyclopentanone and 2-methylbenzaldehyde.The impact of the properties of base amount,base strength and specific surface area on the catalytic effect was analyzed by the characterization of catalysts.The homogeneous distribution of acid and base of calcium oxide(Ca O)might be the reason for the better catalytic effect.The influence of the reaction temperature,reaction time,catalyst dosage and reactant ratio on the reaction efficiency was examined.The hydrodeoxygenation(HDO)reaction of aldol condensation product was carried out in the presence of Pd/C catalyst,and the branched polycyclic alkane fuel(7-methyldodecahydrocyclopenta[a]indene)was obtained.The density and heating value of hydrodeoxygenation(HDO)products were 0.976 g/m L and 37.53 MJ/L respectively,which can be used as high density jet fuel component or additive.(3)The solvent-free aldol condensation reaction was investigated when cyclopentanone and 2-methylbenzaldehyde were used as feedstocks.The highest yield of products(96.49%)was obtained when Strontium Oxide(Sr O)acted on the solvent-free aldol condensation reaction of cyclopentanone and 2-methylbenzaldehyde.The impact of the properties of base amount,base strength and specific surface area on the catalytic effect was analyzed by the characterization of catalysts.More strong base sites of strontium oxide might be the reason for better catalytic performance.The influence of the reaction temperature,reaction time,catalyst dosage and reactant ratio on the reaction efficiency was examined.The hydrodeoxygenation(HDO)reaction of aldol condensation product was carried out in the presence of Pd/C and HZSM-5catalyst,and the branched polycyclic alkane fuel(1,3-bis((2-methylcyclohexyl)methyl)cyclopentane)was obtained.The density and heating value of hydrodeoxygenation(HDO)products were 0.901 g/m L and 39.75 MJ/L respectively,which can be used as high density jet fuel component or additive.