Maleic Acid Catalyzed Conversion of Hemicellulose to Furfural

Direct catalytic conversion of lignocellulosic biomass to biofuels could improve the carbon efficiency of biofuel production.  We report the use of maleic acid, a dicarboxylic acid, to catalyze the fractionation of biomass into an aqueous solution of pentose (primarily xylose) and insoluble cellulose and lignin, followed by the conversion of the xylose to furfural under higher temperature and pressure.  This method achieved 80-90% yield of xylose through hydrolysis of the hemicellulose from various biomass sources (switchgrass, poplar, pine) and achieved 54-61% yield of furfural (based on original biomass).  We present a kinetic analysis of biomass hydrolysis and furfural formation and discuss application of results from pure sugars to results from biomass conversion.