Methods and systems for processing lignin during hydrothermal digestion of cellulosic biomass solids

摘要

Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods for digesting cellulosic biomass solids may comprise: providing cellulosic biomass solids in a digestion solvent; at least partially converting the cellulosic biomass solids into a phenolics liquid phase comprising lignin, an aqueous phase comprising an alcoholic component derived from the cellulosic biomass solids, and an optional light organics phase; and separating the phenolics liquid phase from the aqueous phase.

主权项

1. A method comprising:
providing cellulosic biomass solids in a digestion solvent; at least partially converting said cellulosic biomass solids into a phenolics liquid phase comprising lignin, an aqueous phase comprising an alcoholic component derived from the cellulosic biomass solids, and an optional light organics phase, at a temperature of between about 150° C. and about 250° C. in a hydrothermal digestion unit in the presence of molecular hydrogen and a slurry catalyst capable of activating molecular hydrogen; separating the phenolics liquid phase from the aqueous phase; at least partially depolymerizing the lignin in the phenolics liquid phase, in the lignin depolymerization unit, that comprises heating the phenolics liquid phase to a temperature in the range of from about 270° C. to about 290° C. in the presence of molecular hydrogen and a catalyst capable of activating molecular hydrogen; forming a reaction product comprising methanol in the phenolics liquid phase while at least partially depolymerizing the lignin;separating at least a portion of the reaction product comprising methanol from the lignin depolymerization unit; and
combining the methanol with the alcoholic component.