Biomass conversion systems having a fluid circulation loop containing backflushable filters for control of cellulosic fines and methods for use thereof

• US 8,846,993 B2
• Filed: 12/20/2011
• Issued: 09/30/2014
• Est. Priority Date: 12/16/2011
• Status: Active Grant

• Current Assignee: Shell USA Incorporated (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Powell, Joseph Broun
• Primary Examiner(s): BHAT, NINA NMN
• Application Number:
  US13/332,309
• Publication Number:
  US 20130152456A1
• Time in Patent Office: 1,015 Days
• Field of Search: 585/240, 585/242, 446/05, 127/37, 530/302, 435/166
• US Class Current: 585/240
• CPC Class Codes: B01D 29/56 in series connection
• CPC Class Codes: B01J 8/00 Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
• CPC Class Codes: C10G 1/002 in combination with oil conversion- or refining processes
• CPC Class Codes: C10G 1/06 by destructive hydrogenation
• CPC Class Codes: C10G 1/065 in the presence of a solvent
• CPC Class Codes: C10G 2300/1014 of vegetal origin
• CPC Class Codes: C10G 3/00 Production of liquid hydrocarbon mixtures from oxygen-containing organic materials, e.g. fatty oils, fatty acids production from non-melting solid oxygen-containing carbonaceous materials C10G1/00
• CPC Class Codes: C10G 3/42 Catalytic treatment
• CPC Class Codes: C10L 1/02 essentially based on components consisting of carbon, hydrogen, and oxygen only
• CPC Class Codes: Y02P 30/20 using bio-feedstock

Abstract

Digestion of cellulosic biomass to produce a hydrolysate may be accompanied by the formation of cellulosic fines which may be damaging to system components. Biomass conversion systems that may address the issue of cellulosic fines may comprise a fluid circulation loop comprising: a hydrothermal digestion unit; a solids separation unit that is in fluid communication with an outlet of the hydrothermal digestion unit; where the solids separation unit comprises a plurality of filters and the filters are in fluid communication with the fluid circulation loop in both a forward and a reverse flow direction; and a catalytic reduction reactor unit that is in fluid communication with an outlet of the solids separation unit and an inlet of the hydrothermal digestion unit; where at least one of the plurality of filters is in fluid communication with an inlet of the catalytic reduction reactor unit.

Claims

1. A method comprising:

providing a biomass conversion system that comprises a fluid circulation loop comprising;

a hydrothermal digestion unit;

a solids separation unit that is in fluid communication with an outlet of the hydrothermal digestion unit;

wherein the solids separation unit comprises a plurality of filters; and

a catalytic reduction reactor unit that is in fluid communication with an outlet of the solids separation unit and an inlet of the hydrothermal digestion unit;

providing a cellulosic biomass in the hydrothermal digestion unit;

at least partially digesting the cellulosic biomass in the hydrothermal digestion unit to form a hydrolysate comprising soluble carbohydrates and cellulosic fines within a liquor phase;

flowing the liquor phase through at least one of the filters to sequester the cellulosic fines; and

backflushing at least a portion of the cellulosic fines to the hydrothermal digestion unit while the liquor phase continues to flow through one or more of the filters to the catalytic reduction reactor unit; and

converting the hydrolysate into higher hydrocarbons.

2. The method of claim 1, further comprising:

forming a reaction product in the catalytic reduction reactor unit.

3. The method of claim 2, wherein the reaction product is used to backflush the cellulosic fines.

4. The method of claim 1, wherein the fluid circulation loop is configured such that countercurrent flow is established in the hydrothermal digestion unit.

5. The method of claim 1, wherein at least one of the plurality of filters comprises a catalytic filter comprising a solid support and a catalyst that is capable of activating molecular hydrogen.

6. The method of claim 5, further comprising:

at least partially converting the soluble carbohydrates into a reaction product on the catalytic filter.

7. The method of claim 6, further comprising:

further converting the soluble carbohydrates into the reaction product in the catalytic reduction reactor unit.

8. The method of claim 1, wherein the plurality of filters are connected in parallel to one another.

9. The method of claim 1, wherein the plurality of filters are arranged on a rotatable filter array.

10. The method of claim 1, further comprising:

reversing a direction of fluid flow in the filters being backflushed; and

reversing a direction of fluid flow in one or more of the other filters so as to backflush cellulosic fines therefrom.

11. The method of claim 1, wherein at least about 60% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.

12. The method of claim 1, wherein at least about 90% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.

13. The method of claim 1, further comprising:

converting the hydrolysate into a biofuel.

14. A method comprising:

providing a biomass conversion system that comprises a fluid circulation loop comprising;

a hydrothermal digestion unit;

a solids separation unit that is in fluid communication with an outlet of the hydrothermal digestion unit;

wherein the solids separation unit comprises a plurality of filters; and

a catalytic reduction reactor unit that is in fluid communication with an outlet of the solids separation unit and an inlet of the hydrothermal digestion unit;

providing a cellulosic biomass in the hydrothermal digestion unit;

at least partially digesting the cellulosic biomass in the hydrothermal digestion unit to form a hydrolysate comprising soluble carbohydrates and cellulosic fines within a liquor phase;

flowing the liquor phase through at least one of the filters to sequester the cellulosic fines;

at least partially converting the soluble carbohydrates into a reaction product in the catalytic reduction reactor unit; and

backflushing at least a portion of the cellulosic fines to the hydrothermal digestion unit using at least a portion of the reaction product; and

converting the hydrolysate into higher hydrocarbons.

15. The method of claim 14, wherein backflushing takes place while the liquor phase continues to flow through one or more of the filters to the catalytic reduction reactor unit.

16. The method of claim 14, wherein the fluid circulation loop is configured such that countercurrent flow is established in the hydrothermal digestion unit.

17. The method of claim 14, wherein at least one of the plurality of filters comprises a catalytic filter comprising a solid support and a catalyst that is capable of activating molecular hydrogen.

18. The method of claim 17, further comprising:

at least partially converting the soluble carbohydrates into the reaction product on the catalytic filter.

19. The method of claim 14, wherein the plurality of filters are connected in parallel to one another.

20. The method of claim 14, wherein the plurality of filters are arranged on a rotatable filter array.

21. The method of claim 14, further comprising:

reversing a direction of fluid flow in the filters being backflushed; and

reversing a direction of fluid flow in one or more of the other filters so as to backflush cellulosic fines therefrom.

22. The method of claim 14, wherein at least about 60% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.

23. The method of claim 14, wherein at least about 90% of the cellulosic biomass, on a dry basis, is digested to produce hydrolysate.

24. The method of claim 14, further comprising:

converting the hydrolysate into a biofuel.