Process for pure carbon production, compositions, and methods thereof

Patent metadata

Field	Value
Publication number	US-10035709-B2
Application number	US-201715618804-A
Country	US
Kind code	B2
Filing date	Jun 9, 2017
Priority date	Mar 15, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

The disclosure provides for methods of oxidizing carbide anions, or negative ions, from salt like carbides at temperatures from about 150° C. to about 750° C. In another aspect, the disclosure provides for reactions with intermediate transition metal carbides. In yet another aspect, the disclosure provides for a system of reactions where salt-like carbide anions and intermediate carbide anions are oxidized to produce pure carbon of various allotropes.

First claim

The invention claimed is:

1. A method for producing diamond and/or graphene by chemically oxidatively reacting carbide with molten metallic halide salt at a reaction temperature range from about 150° C. to about 750° C. to form the diamond and/or graphene from the oxidation of the carbide and to form elemental metal from the cation of the metal salt, wherein the chemical oxidative reaction occurs in the molten metal salt.

2. The method of claim 1 , wherein said carbide is from calcium carbide, magnesium carbide, or aluminum carbide.

3. The method of claim 1 , wherein the carbide is from a carbide having a particle size from 30 microns to 200 microns.

4. The method of claim 1 , wherein said reaction temperature range is from about 250° C. to about 500° C.

5. The method of claim 1 , wherein said reaction temperature range is from about 400° C. to about 600° C.

6. The method of claim 1 , wherein said reaction temperature is in a range from about 250° C. to about 400° C.

7. The method of claim 1 , wherein the reaction is carried out at a temperature below 500° C.

8. The method of claim 1 , wherein the oxidizing reaction is carried out at a temperature below 400° C.

9. The method of claim 1 , wherein the oxidizing reaction is carried out at a temperature below 300° C.

10. The method of claim 1 , wherein said reaction produces the diamond.

11. The method of claim 1 , wherein said reaction produces the graphene.

12. The method of claim 1 , wherein said reaction produces the graphene and the diamond.

13. The method of claim 1 , wherein the yield of the diamond and/or the graphene from the carbide starting material is more than 30%.

14. The method of claim 1 , wherein the yield of the diamond and/or the graphene from the carbide starting material is more than 70%.

15. A method of claim 1 , wherein the reaction takes place under an environment that is void or substantially void of oxygen and/or moisture.

16. A method of claim 1 , wherein the metallic halide salt has a melting point of less than 280° C.

17. The method of claim 1 , wherein the metallic halide salt is in excess relative to the carbide.

18. The method of claim 1 , wherein the metallic halide salt is in excess relative to the carbide in at least twice the stoichiometric ratio.

19. The method according to claim 1 for producing diamond and/or graphene, consisting essentially of chemically oxidatively reacting carbide with molten metallic halide salt at a reaction temperature range from about 150° C. to about 750° C. to form the diamond and/or graphene from the oxidation of the carbide and to form elemental metal from the cation of the metal salt, wherein the chemical oxidative reaction occurs in the molten metal salt.

20. The method of claim 1 , wherein the oxidizing reaction is carried out without agitation.

21. The method of claim 1 , wherein the oxidizing reaction is carried out with agitation.

22. The method of claim 1 , wherein the oxidizing reaction is carried out in a sealed reactor which is loaded at atmospheric pressure and heated.

23. The method of claim 1 , wherein the oxidizing reaction is carried out in a horizontally oriented reactor.

24. The method of claim 1 , wherein the oxidizing reaction is carried out in stacked reactors.

25. The method of claim 1 , wherein the reaction is carried out with an additional material added to the reactor to alter heat and mass transfer during the reaction.

26. The method of claim 1 , wherein the reaction is carried out with use of dopants.

27. The method of claim 1 , wherein after the reaction is complete, the products of reaction are transferred to a separation vessel.

28. The method of claim 1 , wherein the product of the reaction is separated with use of surfactant.

29. The method of claim 1 , wherein the product of the reaction is separated with use of gravity separation.

30. The method of claim 1 , wherein after the reaction unreacted carbide is removed with use of water and acid.

31. The method of claim 1 , wherein after the reaction metal salts are removed with water, alcohol, surfactant, or acid.

32. The method of claim 1 , wherein after the reaction the reaction products are subjected to oxidation in a hot oven or a strong oxidative solution.

33. The method of claim 1 , wherein after the reaction the diamond and/or graphene is classified according to particle size.

34. The method of claim 1 , wherein as part of producing the diamond and/or graphene, the method further comprises removing material that is not element carbon from the products of the oxidizing reaction, and also removing any undesired elemental carbon produced by the oxidizing reaction.

35. The method of claim 1 for producing diamond and/or graphene, the method consisting essentially of chemically oxidatively reacting the carbide with the molten metallic halide salt at the reaction temperature range from about 150° C. to about 750° C. to form the diamond and/or graphene from the oxidation of the carbide and to form the elemental metal from the cation of the metal salt, wherein the chemical oxidative reaction occurs in the molten metal salt, and then separating and purifying the diamond and/or graphene.

36. The method of claim 1 , wherein the carbide is aluminum carbide, the metallic halide salt is stannous chloride, and the reaction temperature is below 300° C.

37. The method of claim 36 , wherein the stannous chloride is used in excess with respect to the aluminum carbide.

38. The method of claim 37 , wherein the excess is an excess of at least twice the stoichiometric ratio, the stannous chloride is anhydrous stannous chloride, the reaction is carried out in an oxygen free and moisture free environment, the reaction temperature is 280° C. or below, and the reaction produces diamond.

39. The method of claim 36 , wherein the stannous chloride is anhydrous stannous chloride.

40. The method of claim 36 , wherein the reaction is carried out in an oxygen free and moisture free environment.

41. The method of claim 36 , wherein the reaction temperature is 280° C. or below.

42. The method of claim 1 , wherein the carbide is calcium carbide, wherein the metallic halide salt is zinc chloride, and wherein the reaction temperature is below 600° C.

43. The method of claim 42 , wherein the zinc chloride is used in excess with respect to the calcium carbide.

44. The method of claim 43 , wherein the excess is an excess of at least twice the stoichiometric ratio, the zinc chloride is anhydrous zinc chloride, the reaction is carried out in an oxygen free and moisture free environment, the reaction temperature is 425° C. or below, and the reaction produces diamond.

45. The method of claim 42 , wherein the zinc chloride is anhydrous zinc chloride.

46. The method of claim 42 , wherein the reaction is carried out in an oxygen free and moisture free environment.

47. The method of claim 42 , wherein the reaction temperature is 425° C. or below.

48. The method of claim 1 , wherein the carbide is calcium carbide, wherei

Assignees

• Univ West Virginia

Inventors

• Stiller Alfred H

Classifications

• C01B32/05 Primary

  Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30 · CPC title

• C01B32/26

  Preparation (by using ultra-high pressure B01J3/06; by crystal growth C30B29/04) · CPC title

• C01B32/184

  Preparation · CPC title

• C01B32/942

  Calcium carbide · CPC title

• B01J19/24

  Stationary reactors without moving elements inside (B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02) · CPC title