Abstract: A reaction vessel including: a material input receiving cellulosic material and a material discharge for the cellulosic material, wherein the cellulosic material flows through the reaction vessel from the material input to the material discharge; a hydrolysate and liquid extraction screen; a hydrolysis zone between the material input and the hydrolysate and liquid extraction screen; a wash zone between the hydrolysate and liquid extraction screen and a wash liquid extraction screen; a wash liquid inlet port for introducing a wash liquid into the wash zone, wherein at least a portion of the wash liquid entering the wash liquid inlet port flows through the wash zone and is extracted by the hydrolysate and liquid extraction screen; a cooking zone between the wash zone and the material discharge and a cooking liquor extraction screen at or below the cooking zone and above the material discharge.

Abstract: A reactor vessel system including: a first reactor vessel having a hydrolysate and liquid extraction screen, a first region above the extraction screen that is maintained at conditions promoting a hydrolysis reaction in the cellulosic material, a second region below the extraction screen in which the hydrolysis is substantially suppressed and a wash liquid inlet below the extraction screen providing wash liquid at a temperature below a hydrolysis temperature; a transport pipe having an inlet coupled to the first reactor vessel and an outlet coupled to a second reactor vessel, and the second reactor vessel includes a liquid discharge that extracts a portion of liquid from the second reactor vessel and directs the portion of liquid to the first reactor vessel or to the transport pipe.

Abstract: Systems are provided for continuously producing chemical cellulose pulp from a slurry of comminuted hardwood material by subjecting the slurry of comminuted hardwood material to a first cooking stage under conditions sufficient to reduce syringyl lignin (s-lignin) content in the hardwood material as compared to guaiacyl lignin (g-lignin) content therein, and thereafter subjecting the slurry of comminuted hardwood material to a second cooking stage under conditions sufficient to reduce the g-lignin content remaining therein after the first cooking stage.

Abstract: Process for bleaching of pulps following cooking of the lignocellulosic material with soda and anthraquinone. The process may produce a whiteness on par with the bleaching of kraft pulp when using a similar bleaching sequence. In some instances, the bleaching sequence may be O-A-Do-Eop-D, O-A-ZDo-Eop-D, A-Do, or A-ZDo.

Abstract: A system and method for extracting C5 sugars including pentose and/or C6 sugars including hexose from a slurry of cellulosic material comprising cellulose, water, and optionally acid.

Abstract: A system and method for extracting pentose from a slurry of cellulosic material comprising cellulose, water, and optionally acid in a two-stage process.

Abstract: A system and method for extracting C5 sugars including pentose and/or C6 sugars including hexose from a slurry of cellulosic material comprising cellulose, water, and optionally acid.

Abstract: A system and method for extracting pentose from a slurry of cellulosic material comprising cellulose, water, and optionally acid in a two-stage process.

Abstract: A method to chemically treat light weight, bulky cellulosic material including: introducing the material to an upper inlet of a substantially vertical treatment vessel; maintaining the material in the vessel at a pressure of at least 20 bar and at a temperature of at least 200° C.; treating the material with a cooking liquor in the vessel; moving the material past at least one anti-compression ring on an inside surface of the vessel, as the material moves downward through the vessel; agitating the material in the vessel, and discharging the treated material from a lower discharge port of the vessel.

Abstract: A method for converting a vapor phase continuous digester to a hydraulic digester including the steps of: operating the vapor phase digester in a vapor phase mode wherein a chip slurry enters the vessel of the digester through a lower chip inlet port, moves up through a top separator, discharges from an upper chip discharge chute of the separator to an upper vapor region of the vessel and falls to a liquor filled region of the vessel; ceasing the flow of the chip slurry to the separator; establishing a chip slurry flow path to an upper portion of top separator, and filling the vessel with liquor and chips such that the chip discharge chute is immersed in liquor.

Abstract: A system and method for extracting pentose from a slurry of cellulosic material comprising cellulose, water, and optionally acid in a two-stage process.

Abstract: A system and method for extracting C5 sugars including pentose and/or C6 sugars including hexose from a slurry of cellulosic material comprising cellulose, water, and optionally acid.

Abstract: A method for feeding a cellulosic fibrous material to a high pressure processing vessel including: pressurizing a low pressure flow of the fibrous material in a high pressure transfer device; discharging a high pressure flow of the fibrous material from the transfer device to a conduit in fluid communication with the processing vessel; discharging a low pressure flow of fluid and fibrous material from the transfer device; downstream of the transfer device, pressurizing the discharged low pressure flow; merging the pressurized low pressure discharge flow with the discharged high pressure flow, and transferring the merged flow to the processing vessel.

Abstract: A method to chemically treat light weight, bulky cellulosic material including: introducing the material to an upper inlet of a substantially vertical treatment vessel; maintaining the material in the vessel at a pressure of at least 20 bar and at a temperature of at least 200° C.; treating the material with a cooking liquor in the vessel; moving the material past at least one anti-compression ring on an inside surface of the vessel, as the material moves downward through the vessel; agitating the material in the vessel, and discharging the treated material from a lower discharge port of the vessel.

Abstract: Method and apparatus for minimizing adherence of lignin to an extraction screen in a semi-chemical pulping process. The method and apparatus generally relate to supplying white liquor and NaOH to as to increase the pH of cooking liquor at or near an extraction screen.

Abstract: Process for bleaching of pulps following cooking of the lignocellulosic material with soda and anthraquinone. The process may produce a whiteness on par with the bleaching of kraft pulp when using a similar bleaching sequence. In some instances, the bleaching sequence may be O-A-Do-Eop-D, O-A-ZDo-Eop-D, A-Do, or A-ZDO.

Abstract: An impregnation vessel including: a vessel container including an upper inlet to receive cellulosic material; a lower discharge port to discharge the cellulosic material from a discharge section of the vessel container; a convergence section internal to the vessel through which passes a flow of the cellulosic material in the vessel; a cavity between an internal wall of the vessel and the convergence section, wherein the cavity has a lower opening to the cellulosic material in the vessel and an upper section shielded from the flow of cellulosic material in the vessel, and an input port in the vessel and opening to the cavity, wherein the input port is connectable to a source of hot liquid to be added to the cellulosic material in the vessel.

Abstract: A reactor vessel system including: a first reactor vessel having a hydrolysate and liquid extraction screen, a first region above the extraction screen that is maintained at conditions promoting a hydrolysis reaction in the cellulosic material, a second region below the extraction screen in which the hydrolysis is substantially suppressed and a wash liquid inlet below the extraction screen providing wash liquid at a temperature below a hydrolysis temperature; a transport pipe having an inlet coupled to the first reactor vessel and an outlet coupled to a second reactor vessel, and the second reactor vessel includes a liquid discharge that extracts a portion of liquid from the second reactor vessel and directs the portion of liquid to the first reactor vessel or to the transport pipe.

Abstract: A reaction vessel including: a material input receiving cellulosic material and a material discharge for the cellulosic material, wherein the cellulosic material flows through the reaction vessel from the material input to the material discharge; a hydrolysate and liquid extraction screen; a hydrolysis zone between the material input and the hydrolysate and liquid extraction screen; a wash zone between the hydrolysate and liquid extraction screen and a wash liquid extraction screen; a wash liquid inlet port for introducing a wash liquid into the wash zone, wherein at least a portion of the wash liquid entering the wash liquid inlet port flows through the wash zone and is extracted by the hydrolysate and liquid extraction screen; a cooking zone between the wash zone and the material discharge and a cooking liquor extraction screen at or below the cooking zone and above the material discharge.

Abstract: A method for adding cooking liquor into a vapor phase continuous digester for producing chemical cellulose pulp from cellulose chips including: introducing a slurry of the cellulose chips from a feed system to an inverted top separator in a top vapor phase section of the digester; distributing the slurry of the cellulose chips from the top separator into the vapor phase section of the digester; passing liquor through a conduit included with the drive shaft assembly of the top separator, and introducing the liquor from the conduit into the slurry as the slurry flows through the top separator or is distributed from the separator into the vapor phase section.