High coking value pitch
A high coking value pitch prepared from coal tar distillate and has a low softening point and a high carbon value while containing substantially no quinoline insolubles is disclosed. The pitch can be used as an impregnant or binder for producing carbon and graphite articles.
1. A method of creating a pitch, comprising:
a) heating a coal tar distillate having a boiling range beginning from at least 270° C. under pressure to obtain a tar;
b) distilling the tar to create a pitch having a coking value of at least 55% and a softening point of at least 110° C. and less than 140° C., wherein the pitch has less than about 0.5% quinoline insolubles by weight.
2. The method of claim 1 wherein the boiling range begins at about 315° C.
3. The method of claim 1 wherein the boiling range begins at about 355° C.
4. The method of claim 1 wherein the pressure of step a) is of from about 0.345 MPa(g) to about 0.83 MPa(g).
5. The method of claim 4 wherein the pressure is up to 0.69 MPa(g).
6. The method of claim 1 wherein the coal tar distillate of step a) is heated to a temperature of from about 400° C. to about 525° C.
7. The method of claim 6 further comprising heating the coal tar distillate of step a) at a rate of from about 1° C. per hour to about 10° C. per hour.
8. The method of claim 6 further comprising holding the temperature of step a) for about 1 hour to about 7 hours.
9. The method of claim 1 wherein the coking value of step b) comprises a Modified Conradson Carbon coking value of from about 55% to about 70%.
10. A continuous method of creating a pitch, comprising:
a) heating a coal tar distillate having a boiling range beginning at 270° C. to a temperature of at least about 450° C. under pressure while the coal tar distillate is flowing through a reactor, to obtain a tar;
b) distilling the tar to create pitch, having a coking value of at least 55% and a softening point of at least 110° C. and less than 140° C., wherein the pitch has less than about 0.5% quinoline insolubles by weight.
11. The method of claim 10 further comprising the coal tar distillate having a boiling range beginning from about 315° C.
12. The method of claim 10 further comprising the coal tar distillate having a boiling range beginning from about 355° C.
13. The method of claim 10 wherein the coking value of step b) comprises a Modified Conradson Carbon coking value of from about 55% to about 70%.