Pelletization and calcination of green coke using an organic binder
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 75 mm into undersized and oversized fractions, where the undersized fraction comprises a particle size of less than about 4.75 mm and the oversized fraction comprises a particle size of more than about 4.75 mm;
providing an organic based binder to the undersized fraction;
pelletizing the undersized fraction with the binder to form pelletized coke, the binder being at a concentration providing sufficient strength to enable mechanical handling the pelletized coke after production;
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 the binder is present in an amount less than 15% by weight of the undersized fraction.
4. The method according to claim 1 wherein the binder is selected from a group consisting of starch, sugar, carboxyl methyl cellulose, polyvinyl alcohol, lignosulphonate, or hemicellulose.
5. The method according to claim 4 wherein pelletizing the undersized fraction includes producing pellets with a pellet size of between about 1 mm to 25 mm.
6. The method according to claim 1 further comprising milling or pulverizing the undersized fraction before providing the organic based binder and pelletizing.
7. The method according to claim 6 wherein the milled or pulverized undersized fraction has a particle size of <2 mm.
8. A method of calcining green petroleum coke, said method comprising:
milling green coke to a particle size of wherein 95% is less than 75 microns;
pelletizing the milled coke with an organic base binder to form pelletized coke, wherein the organic base binder is present in an amount less than 5% by weight of the milled 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 pelleting the milled coke includes the binder present in an amount providing sufficient strength to enable mechanical handling of the pelletized coke.
11. The method according to claim 10 wherein the binder is a water soluble organic binder.
12. The method according to claim 11 wherein pelletizing the milled coke includes producing pellets with a pellet size of between about 1 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 75 mm into undersized and oversized fractions, where the undersized fraction comprises a particle size of less than about 4.75 mm and the oversized fraction comprises a particle size of more than about 4.75 mm;
providing an organic binder to the undersized fraction;
briquetting the undersized fraction with the binder to form briquetted coke, the binder being present at a concentration providing sufficient strength to enable mechanical handling the briquetted coke after production;
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 a binder in the amount less than about 15% by weight.
16. The method according to claim 13 further comprising milling or pulverizing the undersized fraction before briquetting the undersized fraction.
17. The method according to claim 6 , wherein the milled or pulverized undersized fraction has a particle size as fine as 95% passing a 200 Tyler mesh screen.
18. The method according to claim 1 , wherein the organic based binder comprises a water soluble organic based binder.
19. The method according to claim 8 , wherein the organic base binder is present in an amount less than 1% by weight of the milled coke.