Production of carbon nanochains and nanotubes from biomass

Patent metadata

Field	Value
Publication number	US-11975970-B2
Application number	US-202117384364-A
Country	US
Kind code	B2
Filing date	Jul 23, 2021
Priority date	Sep 22, 2020
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

High quality carbon nanochains or carbon nanotubes are produced by methods that include mixing a carbon-containing feedstock with a catalyst to form a feedstock/catalyst mixture, or coating a catalyst with a carbon-containing feedstock, and subjecting the feedstock/catalyst mixture or feedstock-coated catalyst to irradiation with a laser to convert the feedstock into carbon nanochains or carbon nanotubes in the presence of the catalyst. In some instances, the feedstock is converted to a char by pyrolysis and the char is instead subjected to laser irradiation. The carbon-containing feedstock can be a biomass or a carbonaceous material. In some instances, the catalyst is a metal salt, preferably a transition metal salt. In some instances, the catalyst is an elemental metal, an alloy, or a combination thereof.

First claim

What is claimed is:

1. A method for producing carbon nanochains, the method comprising:
subjecting a feedstock/catalyst mixture comprising a carbon-containing feedstock and a catalyst to irradiation with a laser to convert the feedstock into carbon nanochains in the presence of the catalyst, wherein
the carbon-containing feedstock is a biomass, a carbonaceous material, or a combination thereof; and
the catalyst is a transition metal salt.

2. The method of claim 1 , further comprising converting the feedstock/catalyst mixture to a powdered form prior to being subjected to irradiation with the laser.

3. The method of claim 1 , wherein
the carbon-containing feedstock is a biomass, the biomass comprising one or more of lignin, lignocellulose, microcrystalline cellulose, wood flour, sawdust, a dehydrated agricultural product, dehydrated food waste, dehydrated livestock feces, miscanthus , switchgrass, hemp, poplar, willow, sorghum, sugarcane, bamboo, agave, alfalfa, a grain, algae, and oil palm, or
the carbon-containing feedstock is a carbonaceous material, the carbonaceous material comprising one or more of an artificial polymer, a natural polymer, a plastic, peat, coal, pitch, coke, a carbon black, an activated carbon, a mesophase carbon, and charcoal.

4. The method of claim 1 , wherein the laser is immobile and the method further comprises:
forming the mixture into a solid form prior to subjecting to laser irradiation; and
rotating or rastering the solid form while subjecting the solid form to the laser irradiation.

5. The method of claim 1 , wherein the feedstock/catalyst mixture has a feedstock to catalyst ratio ranging from about 93:7 to about 99.7:0.1 by weight.

6. A method for producing carbon nanotubes, the method comprising:
subjecting a feedstock/catalyst mixture comprising a carbon-containing feedstock and a catalyst to irradiation with a laser to convert the feedstock into carbon nanotubes in the presence of the catalyst, wherein
the carbon-containing feedstock is a biomass, a carbonaceous material, or a combination thereof; and
the catalyst is an elemental metal, an alloy, or a combination thereof.

7. The method of claim 6 , further comprising converting the feedstock/catalyst mixture to a powdered form prior to being subjected to irradiation with the laser.

8. The method of claim 6 , wherein
the carbon-containing feedstock is a biomass, the biomass comprising one or more of lignin, lignocellulose, microcrystalline cellulose, wood flour, sawdust, a dehydrated agricultural product, dehydrated food waste, dehydrated livestock feces, miscanthus , switchgrass, hemp, poplar, willow, sorghum, sugarcane, bamboo, agave, alfalfa, a grain, algae, and oil palm, or
the carbon-containing feedstock is a carbonaceous material, the carbonaceous material comprising one or more of an artificial polymer, a natural polymer, a plastic, peat, coal, pitch, coke, a carbon black, an activated carbon, a mesophase carbon, and charcoal.

9. The method of claim 6 , wherein the laser is immobile and the method further comprises:
forming the mixture into a solid form prior to subjecting to laser irradiation; and
rotating or rastering the solid form while subjecting the solid form to the laser irradiation.

10. The method of claim 6 , wherein the feedstock/catalyst mixture has a feedstock to catalyst ratio ranging from about 93:7 to about 99.7:0.1 by weight.

11. A method for producing carbon nanochains, the method comprising:
subjecting a feedstock/catalyst mixture comprising a carbon-containing feedstock and a catalyst to pyrolysis to convert the mixture to a feedstock/catalyst-containing char; and
subjecting the char to irradiation with a laser to convert the feedstock into carbon nanochains in the presence of the catalyst, wherein
the carbon-containing feedstock is a biomass, a carbonaceous material, or a combination thereof; and
the catalyst is a transition metal salt.

12. The method of claim 11 , further comprising converting the feedstock/catalyst mixture to a powdered form prior to being subjected to irradiation with the laser.

13. The method of claim 11 , wherein
the carbon-containing feedstock is a biomass, the biomass comprising one or more of lignin, lignocellulose, microcrystalline cellulose, wood flour, sawdust, a dehydrated agricultural product, dehydrated food waste, dehydrated livestock feces, miscanthus , switchgrass, hemp, poplar, willow, sorghum, sugarcane, bamboo, agave, alfalfa, a grain, algae, and oil palm, or
the carbon-containing feedstock is a carbonaceous material, the carbonaceous material comprising one or more of an artificial polymer, a natural polymer, a plastic, peat, coal, pitch, coke, a carbon black, an activated carbon, a mesophase carbon, and charcoal.

14. The method of claim 11 , wherein the laser is immobile and the method further comprises:
forming the mixture into a solid form prior to subjecting to pyrolysis; and
rotating or rastering the solid form char while subjecting the solid form char to the laser irradiation.

15. The method of claim 11 , wherein the feedstock/catalyst mixture has a feedstock to catalyst ratio ranging from about 93:7 to about 99.7:0.1 by weight.

16. A method for producing carbon nanotubes, the method comprising:
subjecting a feedstock/catalyst mixture comprising a carbon-containing feedstock and a catalyst to pyrolysis to convert the mixture to a feedstock/catalyst-containing char; and
subjecting the char to irradiation with a laser to convert the feedstock into carbon nanotubes in the presence of the catalyst, wherein
the carbon-containing feedstock is a biomass, a carbonaceous material, or a combination thereof; and
the catalyst is an elemental metal, an alloy, or a combination thereof.

17. The method of claim 16 , further comprising converting the feedstock/catalyst mixture to a powdered form prior to being subjected to irradiation with the laser.

18. The method of claim 16 , wherein
the carbon-containing feedstock is a biomass, the biomass comprising one or more of lignin, lignocellulose, microcrystalline cellulose, wood flour, sawdust, a dehydrated agricultural product, dehydrated food waste, dehydrated livestock feces, miscanthus , switchgrass, hemp, poplar, willow, sorghum, sugarcane, bamboo, agave, alfalfa, a grain, algae, and oil palm, or
the carbon-containing feedstock is a carbonaceous material, the carbonaceous material comprising one or more of an artificial polymer, a natural polymer, a plastic, peat, coal, pitch, coke, a carbon black, an activated carbon, a mesophase carbon, and charcoal.

19. The method of claim 16 , wherein the laser is immobile and the method further comprises:
forming the mixture into a solid form prior to subjecting to pyrolysis; and
rotating or rastering the solid form char while subjecting the solid form char to the laser irradiation.

20. The method of claim 16 , wherein the feedstock/catalyst mixture has a feedstock to catalyst ratio ranging from about 93:7 to about 99.7:0.1 by weight.

Assignees

• Univ George Washington

Inventors

• Wagner Michael J
• Banek Nathan A
• Abele Dustin T
• Mckenzie Jr Kevin R

Classifications

• C01B32/18 Primary

  Nanoonions; Nanoscrolls; Nanohorns; Nanocones; Nanowalls · CPC title

• B01J19/121

  Coherent waves, e.g. laser beams (lasers per se H01S3/00) · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01B32/162

  characterised by catalysts · CPC title

• B01J2219/02

  Apparatus characterised by their chemically-resistant properties · CPC title