Study On Synthesis Of Levulinic Acid

In this thesis, a variety of new methods toward syntheses of levulinic acid wereinvestigated, including ultrasound-microwave assisted hydrochloric acid generateslevulinic acid by hydrolysis of glucose; Production of levulinic acid from browngranulated sugar catalyzed by aluminum chloride; Production of levulinic acid frombrown granulated sugar catalyzed by silica supported ferric sulfate; Production ofLevulinic Acid from sucrose catalyzed by S₂O₈^2-/Al₂O₃-Fe₂O₃. The specific resultsare as follows:Taked the sucrose as row material to prepare for levulinic acid by usingS₂O₈^2-/Al₂O₃-Fe₂O₃, the reaction temperature, concentration of sucrose, reaction time,amount of catalyst on the yield of levulinic acid were investigated by Single-FactorExperiment and optimized the conditions. The result showed that the best high-yieldof levulinic acid was35.03%under the optimal condition: reaction at30g/L sucroseconcentration and catalyst0.2g after2hours at200°C.Taked the brown granulated sugar as row material to prepare for levulinic acidby using silica supported ferric sulfate, the optimal reaction condition was determinedby orthogonal design, the concentration of brown granulated sugar, amount of catalyst,reaction time, reaction temperature on the yield of levulinic acid were investigated bySingle-Factor Experiment and optimized the conditions. The result showed that thebest high-yield of levulinic acid was39.95%under the optimal condition: reaction at20g/L brown granulated sugar concentration and catalyst1.5g after30minutes at200°CProduction of levulinic acid from brown granulated sugar catalyzed by aluminumchloride was studied, the effects of technological condition such as the concentrationof brown granulated sugar, reaction temperature, amount of catalyst, reaction time onthe yield of levulinic acid were investigated by orthogonal design, the optimalreaction conditions were determined by Single-Factor Experiment. The result showedthat the best high-yield of levulinic acid was42.59%under the optimal condition:reaction at20g/L brown granulated sugar concentration and catalyst2g after20minutes at160°C.Taked the glucose as row material to prepare for levulinic acid by usingultrasound-microware assisted method, the optimal reaction condition was determinedby Single-Factor Experiment. The result showed that the best high-yield of levulinic acid was49.1%under the optimal condition: reaction at5mol/L hydrochloric acidconcentration and the ratio of glucose to hydrochloric acid of1:0.7after60minutes at100°C.The new proposed method is simple and rapid compared to those reported inrelated literatures.A high performance liquid chromatographic method was established for theseparation and determination of levulinic acid,5-hydroxymethyl furfural and formicacid in the synthetic products, with a simple sample pretreatment, good separationeffect, accurate results. The chromatography conditions were as follows: AgilentTC-C18（2）（4.6×250mm,5μm） column, and Agilent1200series RID refractive indexdetector, using acetonitrile: phosphate-sodium dihydrogen: phosphate （pH=2.6）=15:85（volume ratio） as mobile phase; injection temperature at30℃; flow rateof liquid at1mL/min; wavelength:210nm; sample volume:20μL; eternal standardmethod for quantitative peak area.The sample of levulinic acid was characterized with Mass Spectrometry.