Method of controlling swelling and shrinkage during synthesis of coke
Methods of treating a carbon foam precursor to facilitate subsequent foaming of the material at low pressures, which may be on the order of about 0.5 to 1.5 atmospheres, are disclosed. In one embodiment, the carbon foam precursor is subjected to partial devolatilization under controlled conditions with subsequent foaming being effected at low pressure. The carbon foam precursor may be one of various forms of coal including raw coal, coal extract mesophase pitch, synthetic mesophase pitch or petroleum based pitch. The performing treatment of the carbon foam precursor may remove a portion of the internal blowing agent and may alter the fluidity of the carbon foam precursor matrix. In another embodiment, the precursor after being converted into a powder is subjected to oxidation prior to foaming. In another embodiment of the invention a high density carbonaceous material is produced by oxidizing a carbonaceous feedstock to remove from the feedstock volatile gases followed by solvent treatment to remove hydrocarbons thereby providing a carbonaceous feedstock which when coked will produce a material of higher density.
1. A method of making a carbon material comprising
providing a carbonaceous feedstock,
oxidizing said carbonaceous feedstock to remove a portion of the volatiles therefrom and create a partially devolatilized precursor extract,
cooling said devolatilized precursor extract,
converting said devolatilized extract into a powder,
treating said powder with a solvent to dissolve at least a portion of the hydrocarbon molecules contained therein,
separating said solvent and said dissolved hydrocarbons from said powder,
introducing said powder into a sealed vessel,
coking said devolatilized carbonaceous extract powder, and
cooling said coked material.
2. The method of claim 1 including
effecting said oxidation at a temperature of about 100 to 500° C.
3. The method of claim 2 including
effecting said oxidation on said powder having a mesh size of about 60 to 200.
4. The method of claim 3 including
effecting said oxidation at a pressure of about 0.5 to 1.5 atmospheres.
5. The method of claim 1 including
effecting by said oxidation removal from said carbon feedstock of volatile gases.
6. The method of claim 5 including
effecting by said oxidation reduction in hydrogen content of said carbon feedstock.
7. The method of claim 1 including
effecting by said oxidation depletion of the transferable hydrogen in said carbon feedstock to thereby decrease the fluidity thereof.
8. The method of claim 1 including
effecting said separation of solvent and dissolved hydrocarbons by at least one method selected from the group consisting of filtration, centrifugation and evaporation.
9. The method of claim 1 including
producing by said method a carbon material having a density of at least 1.4 g/cm 3 .
10. The method of claim 1 including
selecting said carbonaceous feedstock from the group consisting of petroleum pitch, petroleum tar, coal pitch, coal tar, gasification tar, rubber, and combinations thereof.
11. The method of claim 1 including
selecting said carbonaceous feedstock from the group consisting of recycled motor oil, biomass derivatives, shale oil and combinations thereof.
12. The method of claim 1 including
selecting said solvent from the group consisting of acetone, quinoline, toluene, alcohol, xylene, methylethylketone, carbon tetrachloride, trichloroethylene and combinations thereof.
13. The method of claim 1 including
selecting as said solvent an organic solvent.
14. The method of claim 1 including
wherein said solvent is an ionic liquid.
15. The method of claim 1 including
effecting said coking in an inert gas environment.
16. The method of claim 1 including
creating said powder with a size of about 10 to 325 mesh, and
effecting said partial devolatilization under an inert gas environment.
17. The method of claim 1 including
effecting said foaming under an inert gas environment.
18. The method of claim 1 including
effecting said foaming at a pressure of about 0.5 to 1.5 atmospheres.
19. The method of claim 18 including
effecting said coking at a temperature of about 330° to 600° C. for about 1 minute to 6 hours.
20. The method of claim 19 including
effecting said heating to devolatilize said carbon foam precursor to a temperature of about 100° to 720° C.
21. The method of claim 19 including
creating said devolatilized carbon foam precursor powder with a size of about 10 to 325 mesh.
22. The method of claim 1 including
effecting by said partial devolatilization of said carbon foam precursor by alteration of the fluid nature of the matrix of said heated carbonaceous feedstock.
23. The method of claim 1 including
employing bituminous coal as said carbonaceous feedstock.
24. The method of claim 1 including
employing coal extract as said carbonaceous feedstock.
25. The method of claim 24 including
employing a material selected from the group consisting of de-ashed coal extract and un-ashed coal extract as said carbonaceous feedstock.
26. The method of claim 1 including
employing mesophase pitch as said carbonaceous feedstock.
27. The method of claim 1 including
employing petroleum based pitch as said carbonaceous feedstock.
28. The method of claim 1 including
after said partial devolatilization, but before said coking, storing said devolatilized powder.
29. The method of claim 2 including
employing stagnant inert gas as said inert gas environment.
30. The method of claim 2 including
employing flowing inert gas as said inert gas environment.
31. The method of claim 17 including
employing stagnant inert gas as said inert gas environment.
32. The method of claim 17 including
employing flowing inert gas as said inert gas environment.
33. A method of making a carbon foam material comprising
providing a carbonaceous feedstock,
creating a powder of said carbonaceous feedstock,
heating said powdered carbonaceous feedstock at a pressure of about 0.5 to 1.5 atmospheres at a temperature of about 100 to 500° C.,
treating said powder with a solvent to dissolve at least a portion of the hydrocarbon molecules contained therein,
heating said oxidized carbonaceous feedstock in an inert gas environment to a temperature of about 330° C. to 600° C. to coke said powdered precursor, and
cooling said foam to room temperatures.
34. The method of claim 33 including
effecting said coking an inert gas environment.
35. The method of claim 33 including
employing bituminous coal as said carbon foam precursor.
36. The method of claim 33 including
employing coal extract as said carbon foam precursor.
37. The method of claim 33 including
employing a material selected from the group consisting of de-ashed coal extract and un-ashed coal extract as said carbon foam precursor.
38. The method of claim 33 including
employing hydrogenated coal extract as said carbonaceous feedstock.
39. The method of claim 33 including
employing hydrogenated coal extract as said carbonaceous feedstock.
40. The method of claim 33 including
employing mesophase pitch as said carbon foam precursor.
41. The method of claim 33 including
employing petroleum based pitch as said carbon foam precursor.
42. The method of claim 33 including
effecting said carbonaceous feedstock oxidation in the presence of at least one material selected from the group consisting of water and steam.
43. The method of claim 33 including
devolatilizing said feedstock prior to said oxidation.
44. The method of claim 33 including
creating said precursor powder in the range of about 10 to 325 mesh.
45. The method of claim 33 including
after said oxidation, but prior to said foaming, storing said oxidized precursor.
46. The method of claim 33 including
effecting said coking at a pressure of about 0.5 to 1.5 atmospheres.
47. The method of claim 33 including
after said coking calcining said material.