Green Synthesis Of Bio-based Lubricant And Diesel

With the rapid development of transportation industry,civil industry and manufacturing industry,the demand for high-quality lubricating oil with excellent performance is also increasing.At the same time,the policy of low-carbon development makes the efficient conversion of biomass platform molecules with"zero CO₂emission"become a research highlight.Using cheap biomass resources to green synthesize high value-added chemicals,such as biomass-based lubricant base oil and diesel,is a competitive research route.The main research contents of this paper include:(1)Inspired by the comb-type structure of PAO long-chain branched alkanes,we developed a new strategy to prepare a T-type low-viscosity bio-lubricant base oil using lipid-derived fatty acid methyl esters(FAMEs)as raw materials with a total carbon yield of around 70%achieved.The fatty acid methyl ester compounds(R₁-COOCH₃)were converted to fatty alcohols using methanol as both the solvent and hydrogen donor over hydrothermally prepared Cu/Si O₂ catalyst.Subsequently,Grignard reagents(R₁-CH₂-Mg Br)were prepared by the reaction between the formed fatty alcohols and Mg.In a next step,the nucleophilic addition of Grignard reagents with fatty acid methyl ester(R₂-COOCH₃)generated long-chain symmetrical tertiary alcohol,which was dehydrated and hydrogenated over Pd/C to synthesize T-type C₂₀-C₃₂ fully synthetic bio-lubricant(R₁-C(R₂)-R₁).The properties of the branched representative bio-lubricant C_{32(12'10'10')}are comparable to commercial lubricant Exxon Mobil PAO-3.6.This offers a new promising route for the synthesis of high-quality bio-lubricant.(2)Then,we designed a new synthetic route to prepare alkane diesel from biomass cellulose and hemicellulose platform compounds,including two key steps:first,levulinic acid and furfural undergo aldol condensation reaction under alkaline conditions to construct oxidized diesel precursor,followed by hydrodeoxygenation reaction on the Pd/Nb₂O₅ catalyst to synthesize straight-chain and branched-chain alkane diesel.