Direct Liquefaction of Biomass in a 1-(4-Sulfobutyl)-3-methylmidazolium Hydrosulfate Ionic Liquid/1-Octanol Catalytic System

Abstract

The 1-(4-sulfobutyl)-3-methylmidazolium hydrosulfate ionic liquid/1-octanol catalytic system is quite suitable to produce high-octane-rating fuel from direct liquefaction of biomass. The liquefaction of sawdust in this system was further investigated in this paper. The results show that the liquefaction yield is affected significantly by reaction conditions because of the presence of the competition relationship between degradation and polycondensation reactions. However, the mass percentage of biomass oil always increases with the liquefaction yield rising, indicating that the distribution of liquefaction products directly depends upon the liquefaction yield rather than the reaction parameters. At the optimum conditions of sawdust, 10 g; mean particle size, 1.265 mm; temperature, 423 K; catalyst concentration, 5%; mass ratio of solvent/solid, 6:1; and time, 60 min, the liquefaction yield is 78%. The liquefaction products of lignin and cellulose are enriched in the heavy and light oils, respectively.