PROCESS FOR THE PRODUCTION OF ALCOHOLS FROM BIOMASS

摘要

Alcohols useful as fuel compositions are produced from biomass by pretreating the biomass prior to hydrolysis and fermentation. In the pretreatment, the biomass is contacted with an aqueous solution containing a dilute acid with concentration of up to 10wt% producing a predigested stream containing an aqueous liquor that contains at least a portion of hemicelluloses and a residual biomass that contains celluloses and lignin; separating at least a portion of the aqueous liquor from the residual biomass providing an aqueous liquor stream and a pre-digested biomass stream; then contacting the pre-digested biomass stream with a cooking liquor containing at least one alkali selected from the group consisting of sodium hydroxide, sodium carbonate, sodium sulfide, potassium hydroxide, potassium carbonate, ammonium hydroxide, and mixtures thereof and water. A process that allows for higher recovery of carbohydrates and thereby increased yields is provided.