Methods, compositions, and burner systems for reducing emissions of carbon dioxide gas into the atmosphere
A method of preparing an oxidant stream comprising: burning a combustion mixture comprising (a) one or more fuel composition and (b) oxidant comprising a first oxygen content of about 10 mole % or more and a first carbon dioxide (CO 2 ) gas content of about 68 mole % or more on a dry basis, the burning producing a flue gas comprising CO 2 gas, water vapor, and unreacted oxygen; separating from the flue gas a recycle stream; mixing at least a portion of the recycle stream having a first pressure with a sufficient amount of an oxygen stream having a second pressure which is sufficiently higher than the first pressure to entrain at least a portion of the recycle stream in the oxidant stream and to produce the oxidant stream having a second oxygen content of 10 mole % or more and a second CO 2 gas content of about 68 mole % or more on a dry basis.
1. A method, comprising:
burning with a burner of a furnace a combustion mixture comprising a fuel composition and an oxidant stream, which comprises a first oxygen content of about 10 mole % or more and a first carbon dioxide (CO 2 ) gas content of about 68 mole % or more, on a dry basis, the burning of which produces a flue gas comprising CO 2 and water;
recovering a recycle stream from the flue gas;
removing water from said recycle stream;
separating at least a portion of the carbon dioxide from said recycle stream for capture or storage;
providing a final recycle stream upon removing said water and separating said at least a portion of the carbon dioxide from said recycle stream; and
mixing at least a portion of said final recycle stream with a sufficient amount of an oxygen stream to produce said oxidant stream.
2. The method of claim 1 wherein the first CO 2 gas content is about 70 mole % or more on a dry basis.
3. The method of claim 1 wherein the first oxygen content is from 21 mole % to 32 mole %.
4. The method of claim 1 wherein the first oxygen content is from 21 mole % to 30 mole %.
5. The method of claim 1 wherein the first oxygen content is from 25 mole % to 32 mole %.
6. The method of claim 1 wherein the first oxygen content is from 25 mole % to 30 mole %.
7. The method of claim 1 wherein the mixing comprises injecting the oxygen stream into the final recycle stream at a velocity of from 100 ft/s to about 1400 ft/sec.
8. The method of claim 3 wherein the mixing comprises injecting the oxygen stream into the final recycle stream at a velocity of from 100 ft/s to about 1400 ft/sec.
9. The method of claim 8 further comprising providing a static pressure of about 2 inches of water or more downstream of the injecting.
10. The method of claim 1 further comprising: varying the first oxygen content and the first carbon dioxide gas content to control heat flux and heat transfer in the furnace or inside a burner.
11. The method of claim 10 wherein heat flux and heat transfer in the furnace is controlled by controlling one or more of the flame temperature, operating temperature, flame emissivity, and a combination thereof.
12. The method of claim 10 comprising varying the first oxygen content within from about 21 mole % to about 32 mole %.
13. The method of claim 10 comprising varying the first oxygen content within from about 21 mole % to about 30 mole %.
14. The method of claim 10 comprising varying the first oxygen content within from about 25 mole % to about 32 mole %.
15. The method of claim 10 comprising varying the first oxygen content within from about 25 mole % to about 30 mole %.
16. The method of claim 12 wherein the fuel composition is natural gas.
17. The method of claim 1 further comprising storing said at least a portion of the carbon dioxide.
18. The method of claim 1 wherein the method increases the burner turn-down ratio by a factor of about 1.5 or more.
19. The method of claim 1 wherein the method increases the burner turn-down ratio by a factor of about 1.8 or more.
20. The method of claim 15 wherein the method increases the burner turn-down ratio by a factor of about 2 or more.
21. A method according to claim 1 , wherein the method comprises:
controlling the temperature of a flame produced by said burner of said furnace by;
controlling the flame temperature over flame length by varying said first oxygen content and said first CO 2 gas content of said oxidant stream.
22. The method of claim 21 comprising varying the first oxygen content of the oxidant stream within from about 21 mole % to about 32 mole %.
23. The method of claim 21 comprising varying the first oxygen content of the oxidant stream within from about 21 mole % to about 30 mole %.
24. The method of claim 21 comprising varying the first oxygen content of the oxidant stream within from about 25 mole % to about 32 mole %.
25. The method of claim 21 comprising varying the first oxygen content of the oxidant stream ithin from about 25 mole % to about 30 mole %.
26. The method of claim 22 comprising increasing the oxygen content of the first oxidant stream to increase the flame temperature.
27. The method of claim 22 comprising decreasing the oxygen content of the recycle first oxidant stream to decrease the flame temperature.
28. A method according to claim 1 , wherein the method comprises:
controlling the emissivity and heat transfer properties of said furnace by;
controlling said first oxygen content and said first CO 2 gas content of said oxidant stream.
29. The method of claim 28 wherein the fuel composition is natural gas.