Preparation Of High Value-added Liquid Biofuels By Hydrolyzing Cellulose In Biphasic System

Economic and social development has brought us the better life, meanwhile, the energy crisis and environmental pollution. Because biomass is the most abundant renewable resource on earth, the conversion of biomass into liquid fuels is important for the sustainable development of human.Here, microcrystalline cellulose and paper pulp were used as raw material to produce furfural derivates that can be easily converted into liquid biofuels, and the effect of three catalysts, LiCl, ZnCl2/LiCl, and ZnCl2 on the produce yields was investigated. We also researched on the reaction conditions of converting cellulose into furfural derivates, the qualitative and quantitative analysis for the products, the performance of the catalysts, and the catalytic mechanism.The resultant product was detected with ultraviolet spectroscopy (UV), high performance liquid chromatography (HPLC), H-nuclear magnetic resonance spectroscopy (1HNMR) for qualitative analysis. The results show that, there were mainly three furfural product formed, namely:5-(hydroxymethyl)furfural (HMF), furfural (FF) and 5-(chloromethyl)furfural (CMF) in the reaction of conversion. All of them can be used to generate liquid biofuels or fuel addictives through simple conversion.When ZnCl2/LiCl was used to catalyze the conversion of cellulose into furfural derivates in the HCl/1,2-dichloroethane biphasic system with 1:4 of the mass ratio of ZnCl2 to LiCl, both of the produce yield and the selectivity of the catalyst were increased by 1.5 times compared with the results reported on the literature as only LiCl catalyst under the same reaction conditions. Furthermore, the catalyst was used to catalyze the hydrolysis of the paper pulp, and the yield of 5-(chloromethyl)furfural was close to the yield of microcrystalline cellulose as raw material, which means that ZnCl2/LiCl could be used as a potential catalyst for the conversion of cellulose.The reason why the addition of ZnCl2 could improve the catalytic efficiency of LiCl may be that ZnCl2 can catalyze 5-(hydroxymethyl)furfural to convert 5-(chloromethyl)furfural, while the latter is hydrophobic, and more easily transformed into the organic phase, thus avoiding to be hydrolyzed further, and then the yield of furfural compounds were increased. Meanwhile, ZnCl2 had a strong effect on the hydrogen bond between the cellulose, which can accelerate the hydrolysis of cellulose.The mixture of ZnCl2/LiCl is an effective catalyst for conversion of cellulose into liquid biofuels under mild reaction conditions. Our research results will be important for the prodution of liquid biofuels and the effective conversion of biomass.