Claims
- 1. A process for producing a pitch product having a mesophase content of from 50 to 100% by volume and a melting point below 360.degree. C. and suitable for carbon fiber manufacture which comprises heating a molten carbonaceous feedstock substantially free of mesophase pitch in the presence of an oxidatively reactive sparging gas at a temperature of from about 200.degree. C. to about 350.degree. C. and for a time period sufficient to increase the oxygen content and/or molecular weight of the carbonaceous feedstock, said carbonaceous feedstock remaining substantially free of mesophase pitch after such treatment, and thereafter heating the oxidatively treated carbonaceous feedstock to a melt phase at a higher mesophase-forming temperature while passing a non-oxidative sparging gas therethrough for a time period sufficient to produce a pitch product having said mesophase content and a melting point of below 360.degree. C.
- 2. The process of claim 1 in which the oxidatively reactive gas is selected from the group consisting of oxygen, ozone, hydrogen peroxide, nitrogen dioxide, formic acid vapor, hydrogen chloride vapor, and mixtures thereof.
- 3. The process of claim 2 in which the oxidatively reactive gas is used in admixture with an inert gas.
- 4. The process of claim 3 in which the oxidatively reactive gas is a mixture of oxygen and nitrogen.
- 5. The process of claim 2 wherein the pitch product is substantially 100 percent mesophase with a melting point not greater than 360.degree. C.
- 6. The process of claim 5 in which the feedstock is a pitch.
- 7. The process of claim 6 in which the feedstock is a petroleum pitch.
- 8. A process for producing an anisotropic pitch having a mesophase content of from 50 to 100% and having a melting point of below 360.degree. C., and suitable for carbon fiber manufacture, which comprises heating a carbonaceous feedstock substantially free of mesophase pitch in the presence of an oxidatively reactive sparging gas at a temperature between about 200.degree. C. and about 350.degree. C. and a sparging gas rate from about 1.0 to about 20 SCFH per pound of feedstock for about 2 to about 100 hours to increase the oxygen content and/or molecular weight of the carbonaceous feedstock, said carbonaceous feedstock remaining substantially free of mesophase pitch after such treatment, thereafter heating the oxidatively treated carbonaceous feedstock to a melt phase at a higher mesophase-forming temperature while passing a non-oxidative sparging gas through said molten feedstock to produce a pitch product having said mesophase content, said mesophase having a melting point not greater than 360.degree. C.
- 9. The process of claim 8 in which the feedstock is a pitch.
- 10. The process of claim 9 in which the anisotropic pitch product contains from about 90 to 100% mesophase.
- 11. The process of claim 10 in which the oxidatively reactive sparging gas is air.
- 12. The process of claim 8 in which the oxidatively treated carbonaceous feedstock is heated in the presence of the non-oxidative sparging gas at a temperature of about 350.degree. C. to about 500.degree. C. for about 2 to about 60 hours at a sparging gas rate of from about 1.0 to about 20 SCFH per pound of feedstock.
- 13. The process of claim 12 in which non-oxidative sparging gas is selected from the group consisting of nitrogen, argon, xenon, helium, methane, hydrocarbon-based flue gas, steam, and mixtures thereof.
- 14. The process of claim 13 in which the inert gas is nitrogen.
- 15. The process of claim 14 in which the oxidatively reactive sparging gas is air.
- 16. The process of claim 15 in which the feedstock is a pitch.
- 17. The process of claim 16 in which the feedstock is a petroleum pitch.
RELATED APPLICATIONS
This application is a continuation-in-part of co-pending application Ser. No. 07/099,033, filed Sept. 21, 1987 now abandoned.
US Referenced Citations (17)
Foreign Referenced Citations (1)
Number |
Date |
Country |
65090 |
Apr 1985 |
JPX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
99033 |
Sep 1987 |
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