Systems and apparatus for production of high-carbon biogenic reagents
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.
1. A process for producing a high-carbon biogenic reagent, the method comprising:
performing a first carbonization of a feedstock, thereby producing a first carbonized material, wherein the feedstock comprises biomass;
applying an additive to the first carbonized material, thereby achieving penetration of the additive into the first carbonized material, and thereby producing a treated first carbonized material;
drying the treated first carbonized material, thereby reducing a moisture content of the treated first carbonized material, thereby producing a dried material;
performing a second carbonization, of the dried material, thereby producing a second carbonized material, wherein the second carbonization is achieved using a sweep gas; and
cooling the second carbonized material;
wherein the additive is selected from an acid, a base, or a salt thereof or wherein the additive is selected from the group consisting of a metal, a metal oxide, a metal hydroxide, a metal halide, or a combination thereof.
2. The process of claim 1 , wherein the additive comprises an about 1% aqueous solution of potassium hydroxide.
3. The process of claim 1 , wherein achieving penetration of the additive into the feedstock is achieved by allowing the additive to penetrate the feedstock for about 30 minutes.
4. The process of claim 1 , wherein the performing the first carbonization is achieved using a temperature of about 650° C., a residence time of about 30 minutes, and a pressure of at least about −2 psi to at most about +2 psi.
5. The process of claim 1 , where the performing the second carbonization is achieved using a temperature of about 680° C., a residence time of about 30 minutes, and a pressure of at least about −0.1 psi to at most about −2 psi.
6. The process of claim 1 , further comprising removing interstitial oxygen from the feedstock or the dried material, thereby removing oxygen from the feedstock or dried material.
7. The process of claim 6 , wherein the removing is achieved by penetrating the biomass feedstock with a gas that has at most about 21 vol % of O 2 .
8. The process of claim 7 , wherein the gas comprises nitrogen, CO, CO 2 , or a combination thereof.
9. The process of claim 1 , further comprising, before the second carbonization: introducing the biomass feedstock, treated feedstock, or dried treated feedstock into an enclosed material transport unit; and introducing an inert gas into the enclosed material transport unit, thereby forcing ambient air out of the enclosed material transport system.
10. The process of claim 9 , further comprising heating the inert gas, wherein the heating the inert gas occurs before the introducing the inert gas into the enclosed material transport unit.
11. The process of claim 9 , wherein the forcing ambient air out of the enclosed material transport system achieves an oxygen level in the enclosed material transport unit of not more than about 2% oxygen, not more than about 1% oxygen, not more than about 0.5% oxygen, or not more than about 0.2% oxygen may not be achieved.
12. The process of claim 1 , wherein the oxygen level of the environment for the first carbonization, second carbonization, or the cooling is about 0.5% to about 1.0%.
13. The process of claim 1 , wherein the sweep gas comprises a substantially inert gas.
14. The process of claim 1 , wherein the sweep gas comprises about 32% carbon dioxide, 8% steam, 10% carbon monoxide, and 50% nitrogen.
15. The process of claim 1 , wherein a solids residence time for the first carbonization is at least about 5 min to at most about 60 min.
16. The process of claim 1 , wherein a solids residence time for the second carbonization is at least about 10 min to at most about 120 min.
17. The process of claim 1 , wherein the second carbonization is achieved using a temperature of at least about 250° C. to at most about 700° C.
18. The process of claim 1 , wherein the cooling is achieved using a temperature of at least about 100° C. to at most about 550° C.
19. The process of claim 1 , wherein, during the cooling, secondary pyrolysis reactions occur, wherein the secondary pyrolysis reactions comprise: condensation of carbon-containing gases, thereby forming additional fixed carbon, formation of bonds between adsorbed species and the fixed carbon, or conversion of carbon monoxide to carbon dioxide plus fixed carbon (Boudouard reaction).