Abstract:
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.
Abstract:
A method for digesting cellulosic biomass solids in a hydrothermal digestion unit comprises providing a reactor, a gas feed line, a system for feeding biomass into the reactor, a fluid circulation system including a fluid inlet, pump, and injector; providing a digestion medium containing a slurry catalyst in the digestion unit; circulating the digestion medium through the circulation system; supplying an upward flow of hydrogen through the biomass solids; and maintaining the biomass solids and catalyst at a temperature sufficient to cause digestion of cellulosic biomass solids into an alcoholic component; wherein the fluid inlet includes a stinger unit having an upper surface, an inner volume in communication with the catalyst circulation system, and an opening in the upper surface for allowing fluid to enter the inner volume; and allowing digestion medium to flow into the catalyst circulation system via the catalyst stinger.
Abstract:
Digestion units for processing cellulosic biomass can comprise a chamber having a height that is greater than its width, the chamber having an opening suitable for solids introduction located within the upper 20% of its height; one or more first fluid conduits connected to the chamber within the lower 20% of its height, at least one of the first fluid conduits extending into the chamber and being elevated above the bottom of the chamber; one or more second fluid conduits connected to the chamber within the upper 20% of its height, at least one of the first fluid conduits being fluidly coupled to at least one of the second fluid conduits; a porous medium located in the chamber within the lower 20% of its height; and a movable pressure isolation device covering the opening; wherein the digestion unit is operable to maintain a pressure of at least about 30 bar.
Abstract:
Digestion of cellulosic biomass solids can be enhanced in the presence of a phenolic solvent. Methods for digesting cellulosic biomass solids can comprise providing cellulosic biomass solids containing up to about 50% water by mass in a digestion medium comprising about 50% or more of an organic solvent by volume; heating the cellulosic biomass solids and the digestion medium in a digestion unit in the presence of molecular hydrogen and a slurry catalyst capable of activating molecular hydrogen, thereby forming an alcoholic component derived from the cellulosic biomass solids and liberating lignin therefrom; wherein the digestion medium and the water form a biphasic mixture in which the alcoholic component, slurry catalyst, and lignin are contained; removing at least a portion of the biphasic mixture from the digestion unit; converting at least a portion of the lignin into a phenolic solvent; and returning the phenolic solvent to the digestion unit.
Abstract:
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; combining at least the phenolics liquid phase and the aqueous phase with one another, thereby forming a combined phase; and separating at least a portion of the alcoholic component from at least a portion of the combined phase.