Method of devolatilizing recycled carbon black and associated method
View Patent ↗A method for controlling volatiles in recycled carbon black, such as from pyrolysis of tires, includes deagglomerating the recycled carbon black to substantially reduce the carbon black particle size and impinging an air current on the carbon black particles, preferably in a countercurrent direction, to increase the processing temperature and thereby enhance the release of volatiles. Associated apparatus is disclosed.
1. A method of devolatilizing recycled carbon black comprising
introducing said recycled carbon black into a reactor,
mechanically deagglomerating said carbon black in said reactor,
devolatilizing said carbon black in said reactor,
during said devolatilizing of said deagglomerated carbon black subjecting said carbon black to air flow which results in the oxygen in said air reacting with organics on said carbon to evolve heat in order to to establish a high temperature zone in said reactor and thereby increase the temperature at which said devolatilizing is effected, and
employing said method on recycled carbon black which has been obtained by pyrolysis of vehicle tires in a pyrolysis reactor.
2. The method of claim 1 including
employing said method on carbon black having a size of about 100 to 25000 microns.
3. The method of claim 1 including
effecting flow of said carbon black in a first direction, and
effecting said air flow in a countercurrent direction with respect to the direction of flow of said carbon black.
4. The method of claim 3 including
employing a ratio of air to carbon black of about 0.02 to 0.3.
5. The method of claim 4 including
performing said devolatilizing in an inert gas environment.
6. The method of claim 5 including
employing as said inert gas a gas selected from the group consisting of nitrogen, carbon dioxide and combinations thereof.
7. The method of claim 3 including
increasing the temperature of said carbon black by about 100° F. to 350° F. during said devolatilizing.
8. The method of claim 7 including
cooling said carbon black subsequent to said high temperature devolatilizing.
9. The method of claim 7 including
thermally insulating said high temperature zone.
10. The method of claim 9 including
removing by said method about 15 to 30% of said volatiles in said recycled carbon black.
11. The method of claim 1 including
employing an auger to mechanically deagglomerate said carbon black.
12. The method of claim 11 including
said auger being inclined upwardly from entry to exit.
13. The method of claim 12 including
said auger angle being about 1° to 60°.
14. The method of claim 11 including
introducing said air at an upper portion of said auger.
15. The method of claim 1 including
rotating said auger at about 20 to 100 rpm.
16. The method of claim 1 including
performing said deagglomeration and said devolatilization method on recycled carbon black having a size of about 50 to 5000 microns.
17. The method of claim 1 including
introducing said recycled carbon black to said high temperature zone at about 350° F. to 850° F., and
effecting through said air flow elevation of said carbon black temperature to about 900° F. to 1200° F.
18. The method of claim 1 including
effecting said pyrolysis at a temperature of about 350° F. to 1050° F.
19. The method of claim 1 including
effecting said devolatilization in said reactor which receives recycled carbon black from said pyrolysis reactor.
20. The method of claim 1 including
effecting said air flow co-currently with the direction of flow of said carbon black.
21. The method of claim 1 including
said devolatilization in said high temperature zone taking about 1 to 60 minutes.
22. The method of claim 1 including
delivering at least a portion of said volatiles removed from said recycled carbon black to said pyrolysis reactor.
23. The method of claim 1 including
effecting said deagglomeration by a method selected from the group consisting of the flow of gas through a high velocity gas jet which causes the gas to impinge on said recycled carbon black, a fluid bed reactor, high speed rotating apparatus and combinations thereof.
24. The method of claim 1 including
said air being introduced at a temperature of about 50° F. to 500° F.
25. The method of claim 1 including
effecting preheating of said air before it enters said high temperature zone.
26. The method of claim 25 including
effecting said air preheating by recycled carbon black which has passed through said high temperature zone.
27. The method of claim 1 including
effecting preheating of said recycled carbon black before it enters said high temperature zone.
28. The method of claim 27 including
effecting said recycled carbon black preheating by air which has passed through said high temperature zone.
29. The method of claim 1 including
analyzing gases which have passed through said high temperature zone for oxygen content.
30. The method of claim 1 including
thermally insulating at least a major portion of said high temperature zone.
31. The method of claim 1 including
said deagglomeration reducing said recycled carbon black to an average particle size of about 20 to 200 microns.
32. The method of claim 1 including
exposing said recycled carbon black to said high temperature zone for about 1 to 60 minutes.
33. The method of claim 1 including
monitoring the inert gases and stripped volatiles processed by said deagglomeration and high temperature zone to determine the amount of volatiles removed.