Patent ID: 8389253

Claim:
A method for producing fermentable sugars comprising: (a) providing lignocellulosic biomass comprising lignin; (b) suspending the biomass of (a) in an organic solvent solution comprising water and one or more alkylamines under alkaline conditions whereby a biomass-solvent suspension is formed; (c) heating the biomass-solvent suspension to a temperature of about 100° C. to about 220° C. for about 5 minutes to about 5 hours whereby lignin is fragmented and is dissolved in the suspension; (d) filtering free liquid under pressure whereby the dissolved lignin is removed and whereby carbohydrate-enriched biomass is produced; (e) optionally washing the carbohydrate-enriched biomass of (d) with an organic solvent solution producing a solvent-washed carbohydrate-enriched biomass; (f) removing solvent from the carbohydrate-enriched biomass of (e), or of (d) when (e) is omitted; wherein a readily saccharifiable carbohydrate-enriched biomass is produced; and (g) contacting the readily saccharifiable carbohydrate-enriched biomass of (f) with an enzyme consortium, whereby fermentable sugars are produced.