PROCESSES AND APPARATUS FOR PRODUCING FERMENTABLE SUGARS, CELLULOSE SOLIDS, AND LIGNIN FROM LIGNOCELLULOSIC BIOMASS

摘要

In some variations, the invention provides a process for fractionating biomass, comprising: fractionating the biomass in the presence of a solvent for lignin, sulfur dioxide, and water, to produce a liquor containing hemicellulose, cellulose-rich solids, and lignin; hydrolyzing the hemicellulose contained in the liquor, to produce hemicellulosic monomers; hydrolyzing the cellulose-rich solids to produce glucose; and recovering the hemicellulosic monomers and the glucose, as fermentable sugars, wherein a metal sulfite or metal bisulfite additive is introduced to react directly or indirectly with lignin to produce sulfonated lignin. The disclosed processes may enhance lignin separations as well as promote the co-product potential of lignin.

主权项

1. A process for fractionating biomass, said process comprising:
(a) providing a biomass feedstock comprising cellulose, hemicellulose, lignin; (b) in a digestor, fractionating said feedstock under effective fractionation conditions in the presence of an acid catalyst, a solvent for lignin, and water, to produce a liquor containing hemicellulose, cellulose-rich solids, and lignin; (c) substantially removing said cellulose-rich solids from said liquor; (d) hydrolyzing said hemicellulose contained in said liquor, under effective hydrolysis conditions, to produce hemicellulosic monomers; (e) optionally hydrolyzing said cellulose-rich solids to produce glucose; and (f) recovering said hemicellulosic monomers, and optionally said glucose if step (e) is conducted, to produce fermentable sugars, wherein an additive is introduced in step (b) and/or step (d); wherein said additive is selected from the group consisting of sulfite anions, sulfite salts, bisulfite anions, bisulfite salts, and combinations thereof; and wherein at least a portion of said additive reacts, directly or indirectly, with said lignin to produce sulfonated lignin.