Pelletization and calcination of green coke
A method of calcining green petroleum coke which includes separating the green coke having a particle size of between 0.1 mm and 50 mm into undersized and oversized fractions, pelletizing the undersized fraction with a binder to form pelletized coke, combining the oversized fraction and the pelletized coke to form a feed mixture, and calcining the feed mixture to form calcined coke. The method includes the addition of a pulverization step wherein all the green coke is pulverized before pelletization and the pellets are then calcined to produce a pelletized calcined coke product.
1. A method of calcining green petroleum coke, said method comprising:
separating green coke having a particle size of between 0.1 mm and 50 mm into an undersized and oversized fraction, where the undersized fraction comprises a particle size of less than about 3 mm and the oversized fraction comprises a particle size of more than about 3 mm;
pelletizing the undersized fraction with a binder to form pelletized coke;
combining the oversized fraction and the pelletized coke to form a feed mixture; and
calcining the feed mixture to form calcined coke.
2. The method according to claim 1 wherein calcining the feed mixture includes using a shaft, rotary or rotary hearth, kiln.
3. The method according to claim 1 wherein pelletizing the undersized fraction includes using the binder in the amount of less than or equal to 15% by weight.
4. The method according to claim 3 wherein the binder comprises a coal tar pitch with a softening point of about 90 to about 120° C.
5. The method according to claim 3 wherein the binder comprises any organic based binder at a concentration providing sufficient strength to enable mechanically handling the pellets after production.
6. The method according to claim 5 further comprising the step of heating the undersized fraction to a temperature of about 150° F. before pelletizing.
7. The method according to claim 6 wherein pelletizing the undersized fraction includes producing pellets with a pellet size of between about 2 mm to 25 mm.
8. A method of calcining green petroleum coke, said method comprising:
milling green coke to a particle size of <3 mm;
heating the milled coke to a temperature of about 150° F. before pelletizing;
pelletizing the milled coke with a binder to form pelletized coke; and
calcining the milled coke to form calcined coke.
9. The method according to claim 8 wherein calcining includes using a shaft, rotary or rotary hearth, kiln.
10. The method according to claim 8 wherein pelletizing the milled coke includes using the binder in the amount of less than or equal to 15% by weight.
11. The method according to claim 10 wherein the binder comprises a coal tar pitch with a softening point of about 90 to about 120° C.
12. The method according to claim 11 wherein pelletizing the milled coke includes producing pellets with a pellet size of between about 2 mm to 25 mm.
13. A method of calcining green petroleum coke, said method comprising:
separating green coke having a particle size of between 0.1 mm and 50 mm into an undersized and oversized fraction, where the undersized fraction comprises a particle size of less than about 3 mm and the oversized fraction comprises a particle size of more than about 3 mm;
briquetting the undersized fraction with a binder to form briquetted coke;
combining the oversized fraction and the briquetted coke to form a feed mixture; and
calcining the feed mixture to form calcined coke.
14. The method according to claim 13 wherein calcining the feed mixture includes using a shaft, rotary or rotary hearth, kiln.
15. The method according to claim 13 wherein briquetting the undersized fraction includes using the binder in the amount of less than or equal to 15% by weight.
16. The method according to claim 15 wherein the binder comprises a coal tar pitch with a softening point of about 90 to about 120° C.
17. The method according to claim 13 wherein the binder comprises any organic based binder at a concentration providing sufficient strength to enable mechanically handling the briquettes after production.