Conversion Of Biomass Into Furan Compounds

Biomass is the most important renewable hydrocarbon resources,which is widespread in nature.The conversion of biomass into platform molecules,which can be widely used in materials,energy,food,and pharmaceutical,are important means for the high-value utilization of biomass resources.However,several shortcomings such as harsh reaction conditions,low products yields,occurrence of several side products,etc.still remain in the processes of conversion of biomass into furans.In this paper,the conversion of biomass into 5-hydroxymethylfurfural and furfural was investigated by building up suitable reaction systems and catalysts.The main contents and conclusions include:（1）The influences of reaction systems on furfural production from xylose were investigated.Results showed that the biphasic system of MIBK（methyl isobutyl ketone）/water-NaCl exhibited the best performance,and the xylose conversion rate and furfural yield were up to 85.3% and 42.5%,respectively.After pretreated by this biphasic system,82.0% of hemicelluloses in Eucalyptus could be successfully converted into furfural and the digestibility of the pretreated Eucalyptus was greatly enhanced.（2）CuO was synthesized via precipitation method.The effects of calcination temperature,reaction time,temperature,feedstock concentration,and catalyst dosage on glucose isomerization into fructose were investigated.The morphology of the CuO was characterized.Results showed that a fructose yield of 38.5% was obtained at the optimum reaction condition.（3）D-Xylonic acid was used as an effective catalyst for the conversion of fructose and glucose into 5-hydroxymethylfurfural.The influences of solvents,reaction temperature,time,catalyst dosage,feedstock concentration on the yield of 5-hydroxymethylfurfural were investigated.A 5-hydroxymethylfurfural yield of 84.8% was observed at the optimum reaction condition.（4）Concentrated ZnCl₂ solution was employed for the preparation of furfural and 5-hydroxymethylfurfural from xylose,glucose,and Eucalyptus powder.Results showed that Zn²⁺ could coordinate with carbohydrates and further facilitate the formation of furfural and 5-hydroxymethylfurfural.In 56 wt% ZnCl_2-Boric acid system,9.6% of cellulose and 46.2% of hemicelluloses in Eucalyptus could be successfully converted into 5-hydroxymethylfurfural and furfual,respectively.Interestingly,when Eucalyptus powder was impregnated with 56 wt% ZnCl2 solution before the conversion process,a high yield of furfural（97.8%）accompanied by some amount of glucose and xylose could be obtained.