Patent ID: 8729324

Claim:
A method comprising: providing a biomass conversion system comprising: a first fluid circulation loop comprising: a hydrothermal digestion unit; and a first catalytic reduction reactor unit in fluid communication with an inlet and an outlet of the hydrothermal digestion unit; wherein the first catalytic reduction reactor unit contains at least one first catalyst that is capable of activating molecular hydrogen; and a second fluid circulation loop comprising: a reaction product take-off line in fluid communication with the first fluid circulation loop; a second catalytic reduction reactor unit in fluid communication with the reaction product take-off line; wherein the second catalytic reduction reactor unit contains at least one second catalyst that is capable of activating molecular hydrogen; and a recycle line establishing fluid communication between the first fluid circulation loop and an outlet of the second catalytic reduction reactor unit; providing a cellulosic biomass in the hydrothermal digestion unit; heating the cellulosic biomass in the hydrothermal digestion unit to digest at least a portion of the cellulosic biomass and form a hydrolysate comprising soluble carbohydrates within a liquor phase; wherein at least about 70% of the heat added to the cellulosic biomass in the hydrothermal digestion unit is generated internally in the first catalytic reduction reactor unit and the second catalytic reduction reactor unit; transferring at least a portion of the liquor phase to the first catalytic reduction reactor unit; forming a first reaction product in the first catalytic reduction reactor unit; recirculating at least a portion of the liquor phase to the hydrothermal digestion unit at a first flow rate; and altering the first flow rate to increase or decrease a temperature of the liquor phase in the first fluid circulation loop.