Synthesis Of Renewable Jet Fuel With Chemicals Derived Form Benzaldehyde Derivatives

With the development of economy and the progress of society,the demand for energy is constantly increasing.It is important to develop new renewable energy and adjust the energy structure because the traditional fossil energy is non-renewable and causes serious environmental pollution.Jet fuel is a crucial transportation fuel which usage is increasing year by year.Lignocellulose is the main component of agriculture waste and forest residues.It is cheap,common,avoiding the using of food and arable land.The catalytic conversion of lignocellulose to renewable jet fuel is of strategic importance.In this work,a new route was developed for the synthesis of jet fue range cycloalkanes with methyl isobutyl ketone（MIBK）and methyl benzaldehyde which can both be obtained from lignocellulose.This work mainly contains the following contents:First,oxygenates were prepared by performing C-C coupling through aldol condensation reactions.Aldol condensation reaction of 2-methyl benzaldehyde with MIBK was conducted over the solid-base catalysts under solvent-free conditions or liquid base.After screening a series of liquid base catalysts and solid base catalysts,it was found that LiOH in liquid alkali showed good catalytic activity due to moderate alkalinity and K₂CO₃/Al₂O₃ exhibited the highest activity among the investigated solid base catalysts.Based on the characterizations,the outstanding activity of K₂CO₃/Al₂O₃ was attributed to its a relatively higher surface area and larger amount of base sites.Using LiOH or K₂CO₃/Al₂O₃ as catalyst,the conversion of 2-methylbenzaldehyde and the yield of the product were both higher than 85%by optimizing the reaction conditions.The stability of LiOH and K₂CO_3/Al₂O₃ were investigated.The results showed that these two catalysts both had good stability.The aldol condensations of different lignocellulosic ketones and aldehydes were carried out by using LiOH or K₂CO₃/Al₂O₃ as catalysts.It was found that both catalysts had certain activities and a series of oxygenates were obtained.Finally,the aldol condensation products were converted to cycloalkanes by hydrodeoxygenation（HDO）using batch reactor.Under certain conditions,the obtained oxygenates were subjected to aqueous phase hydrodeoxygenation in a high pressure reactor with Pt/C as a catalyst to obtain different monocyclic or multicyclic aviation fuel range alkane compounds,and all the carbon yield were higher than 80%.According to our measurements,the cycloalkanes as obtained have low freezing points（227.7-240.0 K）and high densities(0.857-0.944 g mL^-1).