Processes for producing biocarbon pellets with high fixed-carbon content and optimized reactivity, and biocarbon pellets obtained therefrom

Patent metadata

Field	Value
Publication number	US-11987763-B2
Application number	US-202217859115-A
Country	US
Kind code	B2
Filing date	Jul 7, 2022
Priority date	Jul 9, 2021
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

Some variations provide a process for producing biocarbon pellets, comprising: pyrolyzing a biomass-containing feedstock in a first pyrolysis reactor to generate a first biogenic reagent and a pyrolysis vapor; introducing the pyrolysis vapor to a separation unit, to generate a pyrolysis precipitate in liquid or solid form; contacting the first biogenic reagent with the pyrolysis precipitate, thereby generating an intermediate material; pelletizing the intermediate material, to generate intermediate pellets; optionally, drying the intermediate pellets; separately pyrolyzing the intermediate pellets in a second pyrolysis reactor to generate a second biogenic reagent and a pyrolysis off-gas; and recovering the second biogenic reagent as biocarbon pellets. Some variations provide a similar process that utilizes a carbon-containing condensed-matter material, which is not necessarily a pyrolysis precipitate. The disclosure provides improved processes for producing biocarbon compositions, especially with respect to carbon yield and biocarbon properties, such as reactivity.

First claim

We claim:

1. A biocarbon pellet composition, wherein the biocarbon pellet comprises a fixed carbon content of at least 60 wt % and wherein the biocarbon pellet requires at least 240 minutes to reach 99% carbon oxidation, as determined by thermogravimetric analysis and recorded to a thermogravimetric analysis graph of weight loss versus time from a thermogravimetric analysis that measures the oxygen reactivity of the biocarbon pellet, wherein the thermogravimetric analysis is performed using a 40° C./min temperature ramp from 25° C. to 950° C. in the presence of pure oxygen.

2. The biocarbon pellet of claim 1 , wherein, according to the TGA graph of weight loss versus time from the thermogravimetric analysis, the biocarbon pellet requires at least 270 minutes to reach 99% carbon oxidation.

3. The biocarbon pellet of claim 1 , wherein, according to the TGA graph of weight loss versus time from the thermogravimetric analysis, the biocarbon pellet requires at least 300 minutes to reach 99% carbon oxidation.

4. The biocarbon pellet of claim 1 , wherein thermogravimetric analysis is performed on an anthracite control sample, wherein the anthracite control sample requires a control time to reach 99% carbon oxidation, and wherein the time required for the biocarbon pellet to reach 99% carbon oxidation is from about 85% to about 100% of the control time.

5. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises volatile carbon, and wherein the TGA graph shows a first carbon-oxidation regime associated with oxidation of volatile carbon, which is succeeded by a second carbon-oxidation regime associated with oxidation of fixed carbon.

6. The biocarbon pellet of claim 5 , wherein the thermogravimetric analysis shows a first-derivative curve peak within the first carbon-oxidation regime for the biocarbon pellet at a temperature of at least about 500° C.

7. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at least 60 wt % fixed carbon.

8. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at least 70 wt % fixed carbon.

9. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at least 80 wt % fixed carbon.

10. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at least 85 wt % fixed carbon.

11. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at least 90 wt % fixed carbon.

12. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at most 10 wt % ash.

13. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at most 5 wt % ash.

14. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at most 1 wt % ash.

15. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at most 20 wt % total volatile matter.

16. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises at most 10 wt % total volatile matter.

17. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises a binder.

18. The biocarbon pellet of claim 17 , wherein the binder is selected from starch, thermoplastic starch, crosslinked starch, starch polymers, cellulose, cellulose ethers, hemicellulose, methylcellulose, chitosan, lignin, lactose, sucrose, dextrose, maltodextrin, banana flour, wheat flour, wheat starch, soy flour, corn flour, wood flour, coal tars, coal fines, met coke, asphalt, coal-tar pitch, petroleum pitch, bitumen, pyrolysis tars, gilsonite, bentonite clay, borax, limestone, lime, waxes, vegetable waxes, baking soda, baking powder, sodium hydroxide, potassium hydroxide, iron ore concentrate, silica fume, gypsum, Portland cement, guar gum, xanthan gum, polyvidones, polyacrylamides, polylactides, phenol-formaldehyde resins, vegetable resins, recycled shingles, recycled tires, a derivative thereof, or a combination of any of the foregoing.

19. The biocarbon pellet of claim 17 , wherein the binder is selected from starch, thermoplastic starch, crosslinked starch, starch polymers, a derivative thereof, or a combination of any of the foregoing.

20. The biocarbon pellet of claim 1 , wherein the biocarbon pellet does not comprise a binder.

21. The biocarbon pellet of claim 1 , wherein the biocarbon pellet comprises an additive.

22. The biocarbon pellet of claim 21 , wherein the additive is selected from acids, bases, or salts thereof.

23. The biocarbon pellet of claim 21 , wherein the additive is selected from metals, metal oxides, metal hydroxides, metal halides, or a combination thereof.

24. The biocarbon pellet of claim 21 , wherein the additive is selected from sodium hydroxide, potassium hydroxide, magnesium oxide, hydrogen bromide, hydrogen chloride, sodium silicate, potassium permanganate, magnesium, manganese, aluminum, nickel, chromium, silicon, boron, cerium, molybdenum, phosphorus, tungsten, vanadium, iron halide, iron chloride, iron bromide, dolomite, dolomitic lime, fluorite, fluorospar, bentonite, calcium oxide, lime, titanium dioxide, or a combination thereof.

25. The biocarbon pellet of claim 1 , wherein total carbon within the biocarbon pellet is at least 50% renewable as determined from a measurement of the 14 C/ 12 C isotopic ratio of the total carbon.

26. The biocarbon pellet of claim 1 , wherein total carbon within the biocarbon pellet is at least 90% renewable as determined from a measurement of the 14 C/ 12 C isotopic ratio of the total carbon.

27. The biocarbon pellet of claim 1 , wherein total carbon within the biocarbon pellet is fully renewable as determined from a measurement of the 14 C/ 12 C isotopic ratio of the total carbon.

28. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized by a Hardgrove Grindability Index of at least 30.

29. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized by a bulk density of at least about 20 lb/ft 3 on a dry basis.

30. The biocarbon pellet of claim 1 , wherein the biocarbon pellet has an average pellet size selected from about 1 mm to about 10 cm, calculated as effective diameter of the biocarbon pellet.

31. The biocarbon pellet of claim 1 , wherein the biocarbon pellet has a pellet shape selected from sphere, cylinder, cube, octagon, hexagon, honeycomb, oval, column, bar, pillow, lentil, random granular, or a combination thereof.

32. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized by a pellet compressive strength at 25° C. of at least about 100 lbf/in 2 .

33. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized by a pellet compressive strength at 25° C. of at least about 150 lbf/in 2 .

34. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized by at most 20 wt % water uptake at 25° C. after 24 hours of soaking in water.

35. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is characterized as non-self-heating when subjected to a self-heating test according to Manual of Tests and Criteria , Seventh revised edition 2019, United Nations, Page 375, 33.4.6 Test N.4: “Test method for self-heating substances.”

36. The biocarbon pellet of claim 1 , wherein the biocarbon pellet is produced by a process comprising:
(a) pyrolyzing,

Assignees

• Carbon Tech Holdings Llc

Inventors

• Slack Dustin
• Mennell James A
• Daugaard Daren

Classifications

• C10L2200/0268

  Phosphor containing compounds · CPC title

• C10L2200/0245

  Lanthanide group metals: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu · CPC title

• C10L2200/0272

  Silicon containing compounds · CPC title

• C10L2200/0231

  Group VI metals: Cr, Mo, W, Po · CPC title

• C10L2200/024

  Group VIII metals: Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt · CPC title