abstract |
Digesting cellulosic biomass solids in the presence of a well-distributed slurry catalyst capable of activating molecular hydrogen may limit the amount of degradation products that form during digestion. Methods for digesting cellulosic biomass solids can comprise: providing cellulosic biomass solids and a slurry catalyst in a hydrothermal digestion unit, the slurry catalyst being capable of activating molecular hydrogen; distributing the slurry catalyst within the cellulosic biomass solids using upwardly directed fluid flow in the hydrothermal digestion unit; heating the cellulosic biomass solids in the hydrothermal digestion unit in the presence of the slurry catalyst, a digestion solvent, and molecular hydrogen, thereby forming a liquor phase comprising soluble carbohydrates; and performing a first catalytic reduction reaction on the soluble carbohydrates within the hydrothermal digestion unit, thereby at least partially forming a reaction product comprising a triol, a diol, a monohydric alcohol, or any combination thereof in the hydrothermal digestion unit. |