Integrated process for the selective fractionation and separation of lignocellulose in its main components

摘要

A method for processing lignocellulose comprises the step of contacting a lignocellulosic substrate with a biphasic liquid system in a reaction vessel, the biphasic liquid system comprising a first, aqueous phase and a second, organic phase which is at least partially immiscible with the first, aqueous phase under the conditions under which step a) is performed. The first, aqueous phase further comprises a carboxylic acid catalyst and the second, organic phase comprises a solvent selected from the group comprising esters, lactones, ethers and/or cyclic ethers with the proviso that said solvent does not comprise a hydroxyl group or hydroxyl groups. Preferred are oxalic acid as a catalyst and 2-methyltetrahydrofuran as the organic solvent. The set-up of a two-phase system affords the selective hemicellulose hydrolysis, together with efficient in situ cellulose-pulp delignification and in situ lignin extraction. Overall, all components are easily separated and are ready for further bio-refinery processing.