Synthesis Of Renewable High-density Fuels With Furfural Compounds And Their Derivatives From Lignocellulose

The synthesis of jet fuel with high density,good low-temperature performance and high thermal stability is of great significance to the aerospace industry.Most of jet fuel usually are synthesized from fossil resources.However,with the depletion of fossil resources and the deterioration of environment,the synthesis of high-density fuels from renewable biomass resources has attracted widespread attention.As the main component of agricultural and forestry waste,lignocellulose is cheap,available and has a wide variety of platform compounds.It is the best candidate to replace fossil resources for the synthesis of high-density fuels.It should be noted that furfural compounds are the most important and widely used among lignocellulose platform compounds.In this paper,the furfural compounds and derivatives,cyclopentanol,methylcyclopentane and 5-methylfurfural,were used to synthesize two kind of high-density fuel.By adding reduced graphene oxide（r GO）to a one-pot H₂SO₄-catalytic reaction of cyclopentanol and methylcyclopentane,a high-performance jet fuel containing bi-and tri-cycloalkanes（C10～C16）was synthesized.The reaction occurs through a consecutive way of dehydration,alkylation,rearrangement,hydrogen transfer and proton transfer.Carbon-based materials,especially r GO,are used as additives to increase the carbon yield by promoting the emulsification of reactants in sulfuric acid.The increased emulsification promotes the alkylation reaction of cyclopentanol with methylcyclopentane and makes proton transfer easier,thereby greatly improves the conversion of methylcyclopentane（54.9%）,the carbon yield（83.2%）and the selectivity of products（97.3%）.Finally,a jet fuel mixture was obtained by distillation with a total yield of 71.8%,showing a high density of 0.90 g/m L,a low freezing point of<-72 ^oC and a high oxidation onset temperature of 195.0 ^oC.This work provides a simple,efficient,and low-cost way to synthesize high-performance jet fuels from biomass.Using 5-methylfurfural as a raw material,a great performance fuel with tetrahydrodimethylcyclopentadiene（THDMCPD）and tetrahydrotrimethylcyclopent-adiene（THTMCPD）as major component was first obtained through a 6-step synthetic route including hydrolysis,dehydration,aldol condensation,Luche reduction,Diels-Alder reaction and hydrogenation.The experimental conditions of each step of the reaction,such as temperature,catalyst,reaction time and solvent,were optimized.The experimental mechanism of each step of the reaction was explored.Finally,a high-density fuel was obtained with a total yield of 65.8%.After measurement,the fuel showed a high density of 0.956 g/m L,a low freezing point of<-70 ^oC,and a high volumetric calorific value of 40.39 MJ/L.Compared with RJ-4and RJ-4-I whose major component are THDMCPD,this fuel has better performance.