Fractionation of lignocellulosics. Solubilization of corn stalk hemicelluloses by autohydrolysis in aqueous medium

This paper discusses the variation profiles of the three main polymeric families (hemicelluloses, cellulose and lignin) of milled corn stalk (Zea maÿs) after aqueous thermomechanochemical treatment. The experimental system used combine explosion and shear effects facilitating the solubilization of hemicelluloses in the aqueous medium. Two starting materials (ethanol–benzene extracted and ethanol–benzene and water extracted) was used. Hemicelluloses are totally solubilized at 220°C (10 min) although there is a loss of lignin (up to a third); cellulose is practically unaffected. A kinetic analysis for the solubilization step was done for calculating the frequency factor and the activation energy for the main treatment using the analytical characterization data from the obtained solid residues.