Abstract: A method including: pretreating biomass feed stock in a first pressurized reactor, wherein the feed stock undergoes hydrolysis in the first pressurized reactor; discharging the feed stock from the first pressurized reactor to a pressurized sealing device having a first pressurized coupling to a feedstock discharge port of the first pressurized reactor; maintaining a vapor phase in the first pressurized reactor by injecting steam; washing the feed stock; draining dissolved hemi-cellulosic material extracted from the feed stock; discharging the feed stock from the pressurized sealing device through a second pressurized coupling to a second pressurized reactor; in the second pressurized reactor, infusing cells of the feed stock with steam or water vapor, and rapidly releasing the pressure applied to the feed stock to cause steam expansion in the cells of the feed stock and refine the feed stock.

Abstract: A system has been developed for pretreating cellulosic biomass feed stock including: a first pressurized reactor receiving the feed stock, wherein the feed stock undergoes hydrolysis in the first pressurized reactor; a sealing device having a first pressurized coupling to a feedstock discharge port of the first pressurized reactor, and a second pressurized coupling to a second pressurized reactor; a drain for a liquid including dissolved hemi-cellulosic material extracted from the feed stock in at least one of the first pressurized reactor and the sealing and extraction device; the second pressurized reactor assembly receiving the pressurized feed stock from the sealing device at a pressure substantially greater than the pressure in the first pressurized reactor, wherein cells of the feed stock are infused with water in the second pressurized reactor, and an expansion device downstream of the second pressurized reactor assembly, wherein the expansion device rapidly releases the pressure of the feed stock disc

Abstract: A system has been developed for pretreating cellulosic biomass feed stock including: a first pressurized reactor receiving the feed stock, wherein the feed stock undergoes hydrolysis in the first pressurized reactor; a sealing device having a first pressurized coupling to a feedstock discharge port of the first pressurized reactor, and a second pressurized coupling to a second pressurized reactor; a drain for a liquid including dissolved hemi-cellulosic material extracted from the feed stock in at least one of the first pressurized reactor and the sealing and extraction device; the second pressurized reactor assembly receiving the pressurized feed stock from the sealing device at a pressure substantially greater than the pressure in the first pressurized reactor, wherein cells of the feed stock are infused with water in the second pressurized reactor, and an expansion device downstream of the second pressurized reactor assembly, wherein the expansion device rapidly releases the pressure of the feed stock disc