Delignification of biomass with sequential base treatment

摘要

A method for the production of a saccharification product is provided, the method comprising: a) providing a cellulosic feedstock comprising lignin; b) contacting, in water, the feedstock of (a) with at least one metal carbonate at time 0 hour under suitable initial reaction conditions to produce a first delignification slurry; c) contacting the first delignification slurry with a nucleophilic base at time (0+n) hour, where n represents a number greater than zero, under suitable secondary reaction conditions to form a second delignification slurry comprising a lignin-containing liquid fraction and a polysaccharide-enriched solid fraction; d) separating the lignin-containing liquid fraction from the polysaccharide-enriched solid fraction; and e) contacting at least a portion of the polysaccharide-enriched solid fraction with an enzyme consortium to produce a saccharification product comprising xylose and glucose monomers wherein the overall yield of xylose and glucose monomers in the saccharification product are individually at least about 50%.