Systems capable of adding cellulosic biomass to a digestion unit operating at high pressures and associated methods for cellulosic biomass processing
View Patent ↗When processing cellulosic biomass, it may be desirable for a digestion unit to operate without being fully depressurized for process efficiency purposes. Methods for processing cellulosic biomass may comprise providing a biomass conversion system comprising a pressurization zone and a digestion unit that are operatively connected to one another; providing cellulosic biomass at a first pressure; introducing at least a portion of the cellulosic biomass into the pressurization zone and pressurizing the pressurization zone to a second pressure higher than the first pressure; after pressurizing the pressurization zone, transferring at least a portion of the cellulosic biomass from the pressurization zone to the digestion unit, which is at a third pressure that is less than or equal to the second pressure but higher than the first pressure; and digesting at least a portion of the cellulosic biomass in the digestion unit to produce a hydrolysate comprising soluble carbohydrates.
1. A method comprising:
providing a biomass conversion system comprising a pressurization zone and a digestion unit that are operatively connected to one another;
providing a cellulosic biomass at a first pressure;
introducing at least a portion of the cellulosic biomass into the pressurization zone and then pressurizing the pressurization zone to a second pressure that is higher than the first pressure;
after pressurizing the pressurization zone, transferring at least a portion of the cellulosic biomass from the pressurization zone to the digestion unit, which is at a third pressure that is less than or equal to the second pressure but higher than the first pressure; and
digesting at least a portion of the cellulosic biomass in the digestion unit to produce a hydrolysate comprising soluble carbohydrates within a liquor phase.
2. The method of claim 1 , wherein providing a cellulosic biomass and introducing at least a portion of the cellulosic biomass take place at the same time.
3. The method of claim 1 , wherein introducing at least a portion of the cellulosic biomass into the pressurization zone comprises a technique or apparatus selected from the group consisting of a screw feeder, a conveyer, a bin dispenser, manual addition, and any combination thereof.
4. The method of claim 1 , wherein, after transferring at least a portion of the cellulosic biomass, the digestion unit is at a pressure of at least about 30 bar.
5. The method of claim 1 , further comprising:
converting the hydrolysate into a biofuel.
6. The method of claim 1 , wherein at least about 60% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.
7. The method of claim 1 , wherein at least about 90% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.
8. The method of claim 1 , further comprising:
before transferring at least a portion of the cellulosic biomass, reducing the pressure in the digestion unit to a fourth pressure that is at least about 75% of the third pressure.
9. The method of claim 1 , wherein the third pressure ranges between about 30 bar and about 430 bar.
10. The method of claim 1 , wherein the third pressure ranges between about 50 bar and about 330 bar.
11. The method of claim 1 , wherein the third pressure ranges between about 70 bar and about 130 bar.
12. The method of claim 1 , wherein pressurizing takes place, at least in part, by introducing at least a portion of the liquor phase into the pressurization zone.
13. The method of claim 12 , wherein the liquor phase comprises an organic solvent.
14. The method of claim 12 , wherein pressurizing takes place, at least in part, by introducing a gas into the pressurization zone.
15. The method of claim 1 , wherein the cellulosic biomass comprises wood.
16. A method comprising:
providing a biomass conversion system comprising a pressurization zone and a digestion unit that are operatively connected to one another;
providing a cellulosic biomass;
introducing at least a portion of the cellulosic biomass into the pressurization zone and then pressurizing the pressurization zone, at least in part, with a liquor phase comprising an organic solvent;
after pressurizing the pressurization zone, transferring at least a portion of the cellulosic biomass from the pressurization zone to the digestion unit, wherein the digestion unit is at a pressure that is less than or equal to the pressure of the pressurization zone; and
digesting at least about 90% of the cellulosic biomass, on a dry basis, to produce a hydrolysate comprising soluble carbohydrates within a liquor phase.
17. The method of claim 16 , wherein introducing at least a portion of the cellulosic biomass into the pressurization zone comprises a technique or apparatus selected from the group consisting of a screw feeder, a conveyer, a bin dispenser, manual addition, and any combination thereof.
18. The method of claim 16 , wherein pressurizing takes place, at least in part, by introducing a gas into the pressurization zone.
19. The method of claim 16 , further comprising:
converting the hydrolysate into a biofuel.
20. The method of claim 16 , wherein, after transferring at least a portion of the cellulosic biomass, the digestion unit is at a pressure of at least about 30 bar.
21. The method of claim 16 , wherein the pressure of the digestion unit ranges between about 30 bar and about 130 bar.
22. The method of claim 16 , wherein the pressure of the digestion unit ranges between about 50 bar and about 330 bar.
23. The method of claim 16 , wherein the pressure of the digestion unit ranges between about 70 bar and about 130 bar.
24. The method of claim 16 , further comprising:
recirculating at least a portion of a reaction product produced from the hydrolysate back into the digestion unit.