Study On Synthesis Of High Density Fuel Components From Lignocellulose Derivatives

High density fuel,which is composed of cyclic hydrocarbons and can provide more volumetric energy,is widely used in the field of rocket and missile.However,with the increasing consumption of fossil fuels and environmental concerns,using renewable resources-biomass for the preparation of high density biofuel is attracting increasing interests.In this work,we converted the platform molecules coming from the lignocellulose hydrolysis into oxygen-containing intermediates via C-C coupling reaction?alkylation,aldolandDiels-Alderreaction?,followedwith hydrodeoxygenation to obtain branched monocyclic fuel,multi substituted cycloalkanes and multi-cyclic fuels,and tested the properties of these fuels.Alkylation reaction of aromatic oxygenates?anisole,guaiacol and phenol?with hemicellulose/cellulose-derived furfural alcohol?furfuryl alcohol and 5-hydroxymethylfurfural?,followed with hydrodeoxygenation for branched monocyclic fuel has been investigated.In this work,we studied the effects of catalysts,reactant ratio and different feeding ways on the reactions.FeCl₃ exhibits relatively high activity and selectivity for the alkylation of anisole?guaiacol?with furfuryl alcohol,and AlCl₃is the best catalyst for the alkylation of phenol with furfuryl alcohol.The selectivity of targeted product increases with the increase of aromatic oxygenates/furfuryl alcohol.A semi-continuous operation was also adopted for the alkylation of furfuryl alcohol to improve the conversion of aromatic oxygenates and the selectivity of targeted products.When furfuryl alcohol is replaced by 5-hydroxymethylfurfural,the selectivity reaches almost 100%,but the reaction is a little slower and longer time is needed to get full conversion.After hydrodeoxygenation,branched cyclohexane with density of 0.804g/cm³ at 20°C was obtained.Aldol condensation reaction of isophorone and furan aldehyde catalyzed by NaOH,followed with hydrodeoxygenation for synthesis of multi substituted cycloalkanes has been studied.This process was greatly affected by the catalyst dosage,temperature,different base catalysts and the bifunctional HDO catalysts.Increasing catalyst dosage or increasing the temperature can improve the conversion of reactants and the selectivity of target products,the presence of water reduced the basicity of catalyst and slowed down the conversion rate.The activity of 5-hydroxymethyl furfural is higher than that of furfural.After hydrodeoxygenation,the intermediate products can be converted into multi substituted cyclohexane with a density of 0.833 g/cm³.Diels-Alder reaction of dicyclopentadiene and 2-methyl furan followed with hydrodeoxygenation has been researched.In this work,we discussed the influence of zeolites and reactant ratio on the reaction.HY exhibits good catalytic effect.The higher the temperature,the higher the conversion rate and the more the side reaction.The side reaction can be effectively inhibited by adjusting the reactants ratio.After hydeoxygenation,multicyclic hydrocarbons with density of 0.98 g/cm³ were obtained.