SYSTEM AND METHOD FOR PREEXTRACTION OF HEMICELLULOSE THROUGH USING A CONTINUOUS PREHYDROLYSIS AND STEAM EXPLOSION PRETREATMENT PROCESS

• US 20120041186A1
• Filed: 10/25/2011
• Published: 02/16/2012
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Andritz Incorporated
• Original Assignee: Andritz Incorporated
• Inventors: Pschorn, Thomas, Shin, Namshee, Stromberg, Bertil
• Granted Patent: US 8,512,512 B2
• Time in Patent Office: Days
• US Class Current: 536/56
• CPC Class Codes: B27N 1/00 Pretreatment of moulding material
• CPC Class Codes: B27N 3/04 from fibres
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: D21B 1/36 Explosive disintegration by sudden pressure reduction
• CPC Class Codes: D21C 1/02 with water or steam
• CPC Class Codes: D21C 3/22 Other features of pulping processes
• CPC Class Codes: D21C 3/26 Multistage processes
• CPC Class Codes: D21C 7/00 Digesters

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.

Claims

1. A method for pretreating cellulosic biomass feed stock comprising:

pretreating the feed stock in a first pressurized reactor, wherein the feed stock undergoes hydrolysis in the first pressurized reactor;

transferring the feed stock from the first pressurized reactor to a pressurized sealing device;

maintaining a vapor phase in the first pressurized reactor by injecting steam into the first pressurized reactor, wherein the injected steam provides heat energy to the feedstock in the first pressurized reactor;

washing the feed stock in a downstream region of the first pressurized reactor or in the pressurized sealing device;

draining a liquid including dissolved hemi-cellulosic material extracted from the feed stock from at least one of the first pressurized reactor and the pressurized sealing device;

discharging the feed stock from the pressurized sealing device through a second pressurized coupling to a second pressurized reactor, wherein the feed stock is maintained at a higher pressure in the second pressurized reactor than in the first pressurized reactor;

in the second pressurized reactor, infusing cells of the feed stock with steam or water vapor by injecting steam or water vapor into the second pressurized reactor, and

rapidly releasing a pressure applied to the feed stock infused with water to cause steam expansion in the cells of the feed stock and refine the feed stock.

2. The method of claim 1 further comprising introducing at least one of mild acid, sulfur dioxide gas (SO₂), oxygen, compressed air, steam, water and catalyzing agents to the feed stock in at least one of the first pressurized reactor and the second pressurized reactor.

3. The method of claim 1 wherein the step of pretreating the feed stock occurs in the first pressurized reactor having an internal temperature in a range of 110 degrees Celsius to 160 degrees Celsius, and a pressure in a range of 150 kilopascals to 600 kilopascals, and wherein the feed stock remains in the first pressurized reactor for a period of ten minutes to sixty minutes.

4. The method of claim 1 wherein the step of pretreating the feed stock occurs in the first pressurized reactor having an internal temperature in a range of 110 degrees Celsius to 175 degrees Celsius, and a pressure in a range of 150 kilopascals to 1000 kilopascals, and wherein the feed stock remains in the first pressurized reactor for a period of ten minutes to sixty minutes.

5. The method of claim 1 wherein the feed stock flows as a continuous stream through the first pressurized reactor, the pressurized sealing device, the second pressurized reactor and to the rapid release of pressure downstream of the second pressurized reactor.

6. The method of claim 1 wherein the rapid release of pressure reduces the pressure of the feed stock by at least ten bar.

7. The method of claim 1 wherein the washing step is between said transferring step and said draining step and washes the dissolved hemi-cellulosic material from said feedstock between said first pressurized reactor and said second pressurized reactor.

8. The method of claim 1 wherein said washing step is performed at a temperature below 160°

C.

9. The method of claim 1 wherein said washing step is performed at a temperature below 140°

C.

10. The method of claim 1 wherein the infusion of the steam or the water vapor into the second reactor forms a vapor phase in the second pressurized reactor.

11. 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 into the first pressurized reactor;

washing the feed stock in or downstream of the first pressurized reactor;

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

subjecting the feed stock with the infused cells to a rapid pressure release to cause expand and burst the cells of the feed stock.

12. The method of claim 11 further comprising introducing at least one of mild acid, sulfur dioxide gas (SO₂), oxygen, compressed air, steam, water and catalyzing agents to the feed stock in at least one of the first pressurized reactor and the second pressurized reactor.

13. The method of claim 11 wherein the step of pretreating the feed stock occurs in the first pressurized reactor having an internal temperature in a range of 110 degrees Celsius to 160 degrees Celsius, and a pressure in a range of 150 kilopascals to 600 kilopascals, and wherein the feed stock remains in the first pressurized reactor for a period of ten minutes to sixty minutes.

14. The method of claim 11 wherein the step of pretreating the feed stock occurs in the first pressurized reactor having an internal temperature in a range of 110 degrees Celsius to 175 degrees Celsius, and a pressure in a range of 150 kilopascals to 1000 kilopascals, and wherein the feed stock remains in the first pressurized reactor for a period of ten minutes to sixty minutes.

15. The method of claim 11 wherein the feed stock flows as a continuous stream through the first pressurized reactor, the pressurized sealing device, the second pressurized reactor and to the rapid release of pressure downstream of the second pressurized reactor.

16. The method of claim 11 wherein the rapid release of pressure reduces the pressure of the feed stock by at least ten bar.

17. The method of claim 11 wherein the washing step is performed between said discharging step and draining step and washes the dissolved hemi-cellulosic material from said feedstock between said first pressurized reactor and said second pressurized reactor.

18. The method of claim 11 wherein said washing step is performed at a temperature below 160°

C.

19. The method of claim 11 wherein said washing step is performed at a temperature below 140°

C.

20. The process of claim 11 wherein the feedstock flows through said first and said second pressurized reactor as a continuous flow.

21. The process of claim 11 wherein the injection of the steam or the water vapor into the second reactor forms a vapor phase in the second pressurized reactor.

22. A process for pretreatment of lignocellulosic biomass, comprising the steps of:

heating the lignocellulosic biomass with steam to a preselected temperature, at a preselected pressure and for a preselected time to hydrolyze and solubilize hemicelluloses in the lignocellulosic biomass,

explosively decomposing the lignocellulosic biomass by rapidly releasing the pressure to break down the lignocellulosic biomass into fibers, and

extracting a liquefied portion of the lignocellulosic biomass to remove compounds from the lignocellulosic biomass which are inhibitory to enzymatic cellulose hydrolysis and sugar fermentation to ethanol.

23. The process of claim 22, wherein the liquid extraction step is carried out by separating fibrous solids from the liquid of the pretreated lignocellulosic biomass.

24. The process of claim 22, wherein the liquid extraction step is carried out with a sealed mechanical compression device.

25. The process of claim 22, wherein the liquid extraction step is carried out under a pressure of between 1.5 bar to 25 bar with a sealed mechanical compression device.

26. The process of claim 22, wherein the removal step is carried out for the removal of water soluble hydrolyzed hemicellulose.

27. The process of claim 26, wherein the water soluble hydrolyzed hemicellulose includes one or more of xylose, arabinose, C5 sugars, acetic acid and formic acid.

28. The process of claim 22, wherein the lignocellulosic biomass is pretreated by auto-hydrolysis or dilute acid solutions.