Research On The Catalytic Hydrolysis Of Glucose Into 5-HMF In Novel Ionic Liqiud

The diminishing of non-renewable fossil materials, as well as haze and other environmental problems are plaguing the people. In order to solving the problems, developing renewable resources of bioenergy is attracting more and more attention all over the world. As an important platform product, 5-hydroxymethyl-furaldehyde (5-HMF) which is obtained from biomass and can be directly converted into useful chemicals for further reaction, attracted wide attention among most of the biomass product. Early studies showed that 5-HMF can be obtained in high yields from fructose using acids as catalysts. But there are many shortages in this pathway, such as high cost of raw materials, serious corrosion of equipment which lead more and more people to explore the methods for improvement.In this work, we ssynthesized series of polyethylene glycol bis-imidazol-4-toluenesulfonate [PEGn(mim)2][Ts2] (n=200,400,600,800) and used AlCl3·6H2O as a catalyst., and studied the process and reaction mechanism of glucose and cellulose as material to produce 5-HMF on the basis of previous works.Firstly using polyethylene glycol bis-imidazol-4-toluenesulfonate [PEGn(mim)2][Ts2] ionic liquids as solvent, we explored the effect of different influence factors on the target product yield. Studying the influence of diffient ionic liquid, the type of metal chloride catalyst, the dosage of catalyst, reaction temperature and reaction time on glucose dehydration to 5-HMF. T he optimal conditions of glucose dehydration to 5-HMF were found as follows: [PEG2oo(mim)2][Ts2] 1.0g, glucose 0.1g, AlCl3·6H2O 25mg, reaction temperature 130℃, reaction time 25min under these conditions by oil bath, the 5-HMF yield was 65.40%. [PEGn(mim)2][Ts2]/AlCl3·6H2O could be used and demonstrated stable activity after five successive runs.Then we explored the process of the conversion of cellulose into 5-HMF. Researching on the influence of the adding amount of hydrochloric acid and water content on the yield of 5-HMF, we choose hydrochloric acid adding amount is 40%, the mass of water content is 20% as the optimal reaction conditions. We study the influence of the mass ratio of cellulose with ionic liquid on the yield of 5-HMF. The experimental results which shown the optimal reaction conditions is that the mass ratio of cellulose with ionic liquid is 1:40. Then we study the influence of the pretreatment time on the yield of 5-HMF. Considering about saving cost, we choose pretreatment time was 2h. The better process for the catalytic conversion of cellulose was the following: reaction temperature 140℃, reaction time 2h, AlCl3·6H2O 25mg, the yield of 5-HMF is 44.63%.