A PROCESS FOR CONVERTING LIGNOCELLULOSE INTO SUGARS

摘要

A process for converting lignocellulose into sugars comprising the following steps: (a) chemically pre-treating lignocellulose-comprising solid biomass by contacting the biomass with a cooking liquid comprising at least 40 vol% formic acid and at least 50 vol% organic acid, at a temperature in the range of from 90 to 180 °C, at a biomass to liquid ratio in the range of from 1:3 to 1:50 to obtain a pre-treated solid residue and spent cooking liquid; (b) separating the solid residue from the spent cooking liquid; (c) washing the solid residue with washing liquid comprising at least 40 vol% formic acid and at least 50 vol% organic acid to obtain washed solid residue and spent washing liquid; (d) separating the washed solid residue from the spent washing liquid; (e) supplying the spent washing liquid obtained in step (d) to step (a) to form part of the cooking liquid that is contacted with the biomass; (f) evaporating free organic acids from the washed solid residue to obtain evaporated washed solid residue; (g) subjecting the evaporated washed solid residue to enzymatic hydrolysis to obtain sugars.