Preparation 5-hydroxymethylfurfural And Furfural From Lignocellulose In The Ionic Liquids

With the rapid consumption of non-renewable resources, the renewable biomass resources, in particular lignocellulosics biomass, have attracted more attention in producing chemicals. Lignocellulose can be converted into bulk chemicals by a hydrolysis reaction. During hydrolysis, the lignocellulose is cleaved to give monosaccharide, which can be decomposed further into useful chemicals.5-hydroxymethyl-furaldehyde (5-HMF) and furfural, which can be directly converted into fuel through further reaction or useful chemicals, are believed to be very important intermediates for the use of biomass.In this work, the process of lignocellulose degradation to 5-HMF and furfural by using BMIMCl as solvent, HCl and metal chlorides as catalysts was studied. The effects of reaction temperature, reaction time, HCl amount, metal chlorides type, metal chlorides amount and lignocellulose content on the yield of 5-HMF and furfural were investigated. The results showed that high-temperature rapid reaction favor high yield of 5-HMF and furfural. The optimal conditions with wood chip were found as follows: reaction temperature 200℃, reaction time 4 min, HCl∶CrCl₃·6H₂O∶BMIMCl=0.04∶0.012∶1 (mol ratio), 10 wt% wood chip (based on BMIMCI), under these conditions, the yields of 5-HMF and furfural respectively were 55% and 22.9%. The optimal conditions with corncob were found as follows: reaction temperature 200℃, reaction time 6 min, HCl∶CrCl3·6H2O∶BMIMCl=0.04∶0.8%∶1 (mol ratio), 10 wt% corncob (based on BMIMCI), under these conditions, the yields of 5-HMF and furfural respectively were 51% and 31.9%.