Process for producing high-carbon biogenic reagents

Patent metadata

Field	Value
Publication number	US-10174267-B2
Application number	US-201615180650-A
Country	US
Kind code	B2
Filing date	Jun 13, 2016
Priority date	Apr 15, 2011
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

This invention provides processes and systems for converting biomass into high carbon biogenic reagents that are suitable for a variety of commercial applications. Some embodiments employ pyrolysis in the presence of an inert gas to generate hot pyrolyzed solids, condensable vapors, and non-condensable gases, followed by separation of vapors and gases, and cooling of the hot pyrolyzed solids in the presence of the inert gas. Additives may be introduced during processing or combined with the reagent, or both. The biogenic reagent may include at least 70 wt %, 80 wt %, 90 wt %, 95 wt %, or more total carbon on a dry basis. The biogenic reagent may have an energy content of at least 12,000 Btu/lb, 13,000 Btu/lb, 14,000 Btu/lb, or 14,500 Btu/lb on a dry basis. The biogenic reagent may be formed into fine powders, or structural objects. The structural objects may have a structure and/or strength that derive from the feedstock, heat rate, and additives.

First claim

What is claimed is:

1. A process for producing a high-carbon biogenic reagent, the process comprising:
(a) providing a carbon-containing feedstock comprising biomass;
(b) optionally drying the feedstock to remove at least a portion of moisture contained within the feedstock;
(c) optionally deaerating the feedstock to remove at least a portion of interstitial oxygen, if any, contained with the feedstock or the dried feedstock;
(d) in a pyrolysis zone, pyrolyzing the feedstock in the presence of a substantially inert gas for at least 10 minutes and with a pyrolysis temperature selected from about 250° C. to about 700° C., to generate hot pyrolyzed solids, condensable vapors, and non-condensable gases;
(e) separating at least a portion of the condensable vapors and at least a portion of the non-condensable gases from the hot pyrolyzed solids;
(f) in a cooling zone, cooling the hot pyrolyzed solids, in the presence of the substantially inert gas for at least 5 minutes and with a cooling zone temperature less than the pyrolysis temperature, to generate warm pyrolyzed solids;
(g) in an optional cooler that is separate from the cooling zone, cooling the warm pyrolyzed solids to generate cool pyrolyzed solids; and
(h) recovering a high-carbon biogenic reagent comprising at least a portion of the cool pyrolyzed solids.

2. The process of claim 1 , the process comprising drying the feedstock to remove at least a portion of moisture contained within the feedstock.

3. The process of claim 1 , the process comprising deaerating the feedstock to remove at least a portion of interstitial oxygen contained with the feedstock.

4. The process of claim 1 , the process further comprising, prior to step (d), preheating the dried feedstock in a preheating zone in the presence of the substantially inert gas for at least 5 minutes and with a preheating temperature selected from about 80° C. to about 500° C.

5. The process of claim 4 , wherein the preheating temperature is selected from about 80° C. to about 150° C.

6. The process of claim 1 , wherein the pyrolysis temperature is selected from about 400° C. to about 600° C.

7. The process of claim 1 , wherein pyrolysis in step (d) is carried out for at least 20 minutes.

8. The process of claim 1 , wherein pyrolysis conditions of step (d) are selected to maintain the structural integrity or mechanical strength of the high-carbon biogenic reagent relative to the feedstock.

9. The process of claim 1 , wherein the cooling zone temperature is selected from about 150° C. to about 350° C.

10. The process of claim 1 or 4 , wherein each of the zones is located within a single reactor.

11. The process of claim 1 or 4 , wherein each of the zones is located in a separate reactor.

12. The process of claim 1 , wherein the substantially inert gas is selected from the group consisting of N 2 , Ar, CO, CO 2 , H 2 , CH 4 , and combinations thereof.

13. The process of claim 1 , wherein at least some of the substantially inert gas includes one or more non-condensable gas species recycled from step (e).

14. The process of claim 1 , wherein the pyrolysis zone and the cooling zone each comprise a gas phase containing less than 5 wt % oxygen.

15. The process of claim 14 , wherein the pyrolysis zone and the cooling zone each comprise a gas phase containing about 1 wt % oxygen or less.

16. The process of claim 1 or 4 , wherein the process is continuous or semi-continuous.

17. The process of claim 16 , wherein the inert gas flows substantially countercurrent relative to the direction of solids flow.

18. The process of claim 16 , wherein the inert gas flows substantially concurrent relative to the direction of solids flow.

19. The process of claim 1 or 4 , the process further comprising monitoring and controlling the process with at least one reaction gas probe.

20. The process of claim 19 , wherein at least two reaction gas probes are utilized to monitor and control the process.

21. The process of claim 19 , wherein the monitoring and controlling the process improves process energy efficiency.

22. The process of claim 19 , wherein the monitoring and controlling the process improves a product attribute associated with the high-carbon biogenic reagent.

23. The process of claim 22 , wherein the product attribute is carbon content.

24. The process of claim 22 , wherein the product attribute is energy content.

25. The process of claim 22 , wherein the product attribute is structural integrity or mechanical strength.

26. The process of claim 1 or 4 , the process further comprising process gas heating of at least a portion of the condensable vapors with an oxygen-containing gas.

27. The process of claim 26 , wherein the process gas heating is assisted with combustion of natural gas.

28. The process of claim 26 , wherein the process comprises drying the feedstock to remove at least a portion of moisture contained within the feedstock, and wherein heat produced from the process gas heating is utilized, at least in part, for the drying.

29. The process of claim 26 , wherein heat produced from the process gas heating is utilized, at least in part, to heat the substantially inert gas.

30. The process of claim 29 , wherein at least a portion of the substantially inert gas is heated and then introduced to the pyrolysis zone.

31. The process of claim 1 or 4 , the process further comprising combining at least a portion of the condensable vapors, in at least partially condensed form, with the cooled pyrolyzed solids, to increase the carbon content of the high-carbon biogenic reagent.

32. The process of claim 1 or 4 , the process further comprising combining at least a portion of the condensable vapors with the warm pyrolyzed solids, to increase the carbon content of the high-carbon biogenic reagent.

33. The process of claim 1 , the process further comprising introducing at least one additive selected from acids, bases, or salts thereof.

34. The process of claim 33 , wherein the additive is selected from the group consisting of sodium hydroxide, potassium hydroxide, magnesium oxide, hydrogen bromide, hydrogen chloride, sodium silicate, potassium permanganate, and combinations thereof.

35. The process of claim 1 , the process further comprising introducing at least one additive selected from the group consisting of a metal, a metal oxide, a metal hydroxide, a metal halide, and combinations thereof.

36. The process of claim 35 , wherein the additive is selected from the group consisting of magnesium, manganese, aluminum, nickel, chromium, silicon, boron, cerium, molybdenum, phosphorus, tungsten, vanadium, iron chloride, iron bromide, magnesium oxide, dolomite, dolomitic lime, fluorite, fluorospar, bentonite, calcium oxide, lime, and combinations thereof.

37. The process of claim 33 or 35 , wherein the additive is selected to maintain the structural integrity or mechanical strength of the high-carbon biogenic reagent relative to the feedstock.

38. The process of claim 33 or 35 , wherein the presence of the additive in the process increases the carbon content of the high-carbon biogenic reagent compared to an otherwise-identical process without introduction of the

Assignees

• Carbon Tech Holdings Llc

Inventors

• Mennell James A
• Despen Daniel J

Classifications

• C01B32/318

  characterised by the starting materials · CPC title

• C10L2290/145

  of air · CPC title

• C10L2200/025

  Halogen containing compounds · CPC title

• C10L2290/50

  Screws or pistons for moving along solids · CPC title

• C10L2290/52

  Hoppers · CPC title