Study On Green Reaction Process Of Cellulose Based Succinic Anhydride And 5-hydroxymethylfurfural Conversion

The rapid development of global industrialization and modern economy and society has resulted in the sharp consumption of traditional fossil fuels and the serious deterioration of the environment.Energy shortage and environmental degradation have greatly hindered the sustainable development of human society.Therefore,in the face of the problems of exhaustion of fossil energy and environmental pollution,the development of green and sustainable new energy is an important task to solve the problems in the 21st century.The exploiting and utilization of renewable energy resources including solar,wind,water and geothermal energy have greatly alleviated the energy crisis and environmental problems.Unlike clean energy resources such as wind,solar,tidal energy and geothermal energy,biomass energy is the only renewable source of organic carbon in nature.Lignocellulose is considered a major source of biofuel and other value-added products.The effective utilization of biomass base resources can replace petroleum-based chemical products.Therefore,making full use of the abundant natural lignocellulose to produce bio-fuels and chemical products is an important research in the future.In this paper,two research topics are reported.First,the commercially available zinc oxide was used as the catalyst to convert succinic anhydride into dimethyl succinate.Second,the reaction of 5-hydroxymethylfurfural using isopropanol as the liquid hydrogen source into 2,5-dimethylfuran over CuO/MgO/ZrO₂ catalyst was studied.Both green reaction process for the full utilization of cellulose based biological platform compounds to make the high value-added chemical products were developed.Firstly,the conversion of succinic anhydride to dimethyl succinate with methanol as solvent was reported.The influence of catalyst,the loading of catalyst,the volume of solvent,reaction temperature and reaction time on the yields of dimethyl succinate was investigated respectively.The best reaction conditions as follows:0.2 mmol succinic anhydride,6 mg ZnO,1.2 mL methanol,at 140℃ for 10 h,the highest yield was 100%,and the selectivity was 100%.The result indicated that zinc species formed in the reaction process can be deposited again to form zinc oxide,the formed zinc oxide was used for many times,after five times cycle,the yield of dimethyl succinate was still 100%.In addition,this study compared the catalytic properties of zinc oxide with different physicochemical properties and the extending of different substrate and solvent.It was found that the reaction of succinic anhydride and ethanol under the optimal conditions could also obtained a high yield of diethyl succinate（92%）.At the same time,the reaction mechanism by the characterization of intermediate zinc species in the reaction was provided.Finally,the conversion of 5-hydroxymethylfurfural into 2,5-dimethyl furan was reported.Several parameters,such as catalyst,the loading of catalyst,different liquid hydrogen source,reaction temperature and reaction time on the influence of the target product yield were investigated.The yield of 2,5-dimethylfuran was 63.6%in the presence of 0.2 mmol5-hydroxymethylfurfural,25 mg CuO/MgO/ZrO₂ catalyst,3 mL isopropanol at 250℃ for 4 h.