Preparation Of 5-hydroxymethylfurfural Via The Catalytic Hydrolysis Of Cellulose In The Ionic Liquid

As the decreases of the fossil energy , there is in the short of non-renewable energy. 5-hydroxymethylfurfural is an important platform chemical. The production of 5-hydroxymethylfurfural ,wich is obtained directly from renewable biomass is a promising route. 5-hydroxymethylfurfural can be transfered to the biofuels by the next reaction wich would alleviate the energy crisis .We studied the preparation of 5-hydroxymethylfurfural derived from the catalytic hydrolysis of microcrystalline cellulose in the 1-butyl-3-methylimidazolium chloride (BMIMCL) .In this reaction, the catalysts is the metal chlorides and at the low temperature and the atmospheric pressure. We studied the effects of different factors on the yield of 5-HMF, including the mass ratio of water and cellulose, the mass ratio of H2SO4and cellulose, reaction temperature, reaction time, different catalysts,the concentration of raw materials.We obtained that the optimal mass ratio of microcrystalline cellulose and ionic liquid is 1:10,the molar ratio of two metal chlorides(CrCl2 and CuCl2)is 4:1. By designing orthogonal experiments,the optimal conditions of 5-hydroxymethylfurfural obtained from microcrystalline cellulose were as follows: the temperature is 150℃, reaction time 4h, the mass ratio of H2O and microcrystalline cellulose is 1:1, the mass ratio of H2SO4 and microcrystalline cellulose is 0.025, the yield of 5-hydroxymethylfurfural is 43.41%.Further, we studied the decomposition of wheat straw, wich can convert into 5-hydroxymethylfurfural and furfural by dehydration in the ionic liquid. In this reaction, the ionic liquid is1-butyl-3-methylimidazolium chloride(BMIMCL), the catalysts are CrCl2 and CuCl2. We studied the effects of the raw materials'concentration, the wheat straw'particle size, reaction time, reaction temperature, the concentration of HCl on the yield of products. We obtained the optimal mass ratio of wheat straw and ionic liquid is 1:10, the optimal particle size of wheat straw is 20~40mu. By designing orthogonal experiments, the optimal reaction conditions of 5-hydroxymethylfurfural obtained from wheat straw are as follows: the reaction temperature is 170℃,the reaction time is 2h, the mass ratio of HCl and wheat straw is 0.09, and the molar yield of 5-hydroxymethylfurfural is 48.02%, the molar yield of furfural is 20.31%.