High Pressure Direct Contact Oxy-Fired Steam Generator

• US 20110232545A1
• Filed: 12/10/2009
• Published: 09/29/2011
• Est. Priority Date: 12/10/2008
• Status: Active Grant

• Current Assignee: Her Majesty The Queen In Right Of Canada (Government of Canada)
• Original Assignee: Her Majesty The Queen In Right Of Canada (Government of Canada)
• Inventors: Clements, Bruce
• Granted Patent: US 9,512,999 B2
• Time in Patent Office: Days
• US Class Current: 110/234
• CPC Class Codes: F22B 1/1853 coming in direct contact with water in bulk or in sprays
• CPC Class Codes: F22B 1/22 using combustion under pressure substantially exceeding atmospheric pressure
• CPC Class Codes: F22B 1/26 Steam boilers of submerged-flame type, i.e. the flame being surrounded by, or impinging on, the water to be vaporised , e.g. water in sprays
• CPC Class Codes: F22B 37/48 Devices for removing water, salt, or sludge from boilers cleaning internal or external surfaces of water tubes F28G; Arrangements of cleaning apparatus in boilers cleaning external surfaces of tubes by soot blowers F23J; Combinations thereof with boilers
• CPC Class Codes: F22B 37/52 Washing-out devices
• CPC Class Codes: F23J 15/06 of coolers
• CPC Class Codes: F23L 7/007 Supplying oxygen or oxygen-enriched air
• CPC Class Codes: Y02E 20/30 Technologies for a more efficient combustion or heat usage
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply

Abstract

A method and apparatus for direct contact steam generation for a variety of industrial processes including heavy oil recovery, power generation and pulp and paper applications. The steam generation system consists of a combustor (10) and a steam generator (70) and is constructed to be operable at elevated pressures. The fuel, at least one oxidant and a fluid supply including water are supplied at pressure to the combustor. Flue gas from the combustor (10) is delivered to the direct contact steam generator (70) at pressure, and upon direct contact with water, produces a flue gas stream consisting primarily of steam. This product stream can then be cleansed and used for industrial applications. The combustor (10) can be operated with low grade fuel and low quality water with high solids and hydrocarbon contents. The apparatus and method reduce the environmental footprint by reducing air emission, concentrating CO₂ to enable capture and reducing clean water requirements. The removal of solids from the combustor (10) at its second end (62) as well as at the second end of the steam generator (70) as at (78), the use of water injection-type steam quality control and a steam feedback inlet (46) to the combustor (10) from the steam generator (70) enhance the efficiency of the apparatus.

Claims

1. An apparatus for direct contact steam generation comprising a combustor and a steam generator operatively connected to the combustor,

(a) the combustor being constructed and arranged to be selectively operable at a pressure exceeding atmospheric pressure, and having a first combustor end and a second combustor end, and comprising

(i) a combustor wall comprising an outer wall and a refractory liner having an inner surface defining a combustion space;

(ii) a burner proximate the first combustor end;

(iii) at least a first fuel inlet proximate the first combustor end and constructed and arranged to deliver a first fuel to the burner at a delivery pressure exceeding atmospheric pressure;

(iv) at least one oxidant inlet proximate the first combustor end and constructed and arranged to deliver a supply of oxygen to the burner at a delivery pressure exceeding atmospheric pressure;

(v) a plurality of fluid inlets operatively connected to the combustion space and constructed and arranged to deliver a supply of a fluid including water at a delivery pressure exceeding atmospheric pressure; and

(vi) an outlet region proximate the second combustor end and having a flue gas outlet and a combustor residue outlet;

(b) the steam generator having

(i) a housing body having a first generator end, a second generator end and an intermediate region;

(ii) a steam generation fluid inlet proximate the first generator end and constructed and arranged to receive a supply of steam generation fluid including water at a supply pressure greater than the selected combustor operating pressure;

(iii) a flue gas inlet proximate the second generator end and operatively connected to the flue gas outlet of the combustor;

(iv) a steam outlet located in the intermediate region between the flue gas inlet and the first generator end and operatively connected to a steam output delivery means;

and

(v) a residue receiving region proximate the second generator end and having at least one steam generator residue outlet.

2. An apparatus according to claim 1, wherein the supply of fluid includes at least one hydrocarbon material.

3. An apparatus according to claim 1 or claim 2, wherein the refractory liner comprises a set of cooling tubes, and at least one cooling fluid inlet operatively connected to the set of cooling tubes and at least one cooling fluid outlet operatively connected to the set of cooling tubes.

4. An apparatus according to any one of claims 1 to 3, wherein the apparatus further comprises an air separation unit constructed and arranged to be operatively coupled to the at least one oxidant inlet.

5. An apparatus according to any one of claims 1 to 4, wherein the combustor further comprises at least one wash fluid inlet constructed and arranged to selectively deliver wash fluid into the combustor.

6. An apparatus according to claim 5, wherein the combustor comprises at least two wash fluid inlets, constructed and arranged to deliver the wash fluid to contact different surfaces within the combustor including the inner surface of the refractory liner and an inner surface of a region proximate the second combustor end.

7. An apparatus according to any one of claims 1 to 6, wherein the combustor further comprises a water inlet proximate the first combustor end and constructed and arranged to deliver water to the burner at a delivery pressure exceeding atmospheric pressure.

8. An apparatus according to any one of claims 1 to 7, wherein the intermediate region of the steam generator comprises a cleaning zone located between the steam outlet and the second generator end.

9. An apparatus according to claim 8, wherein the cleaning zone comprises at least one of a packed bed, a venturi scrubber, a spray chamber and at least one water reservoir.

10. An apparatus according to any one of claims 1 to 9, wherein the steam generator fluid inlet comprises at least one nozzle, each nozzle having a plurality of jets.

11. An apparatus according to any one of claims 1 to 10, wherein the steam generator further comprises a demister located proximate the steam outlet.

12. An apparatus according to any one of claims 1 to 11, wherein the steam generation fluid comprises water including contaminants.

13. An apparatus according to any one of claims 1 to 12, wherein the steam output delivery means comprises at least one steam quality adjustment means.

14. An apparatus according to claim 13, wherein the steam quality adjustment means comprises a secondary liquid delivery inlet constructed and arranged to deliver a supply of a secondary liquid including water to the steam output delivery means.

15. An apparatus according to any one of claims 1 to 14, wherein the combustor further comprises a steam inlet proximate the first combustor end, and the steam delivery means comprises a recirculation means constructed and arranged to selectively deliver part of the steam output to the steam inlet.

16. An apparatus according to any one of claims 1 to 15, wherein the combustor further comprises at least a second fuel inlet proximate the first combustor end.

17. An apparatus according to any one of claims 1 to 16, wherein the fuel delivered to each fuel inlet is selected from the group consisting of a liquid fuel, a gaseous fuel and a solid fuel and mixtures thereof.

18. An apparatus according to claim 17, wherein the solid fuel is a slurry comprising a liquid and at least one of bitumen, asphaltene, coal, and petroleum coke.

19. An apparatus according to claim 18, wherein the solid fuel is a slurry and comprises an emulsifier.

20. An apparatus according to any one of claims 1 to 19, wherein the outlet region of the combustor comprises a combustor residue grinder.

21. An apparatus according to any one of claims 1 to 20, wherein the combustor has an operable pressure range of between 3 bar and 175 bar, and each fuel inlet, each oxidant inlet and each fluid inlet and each steam generation fluid inlet is constructed and arranged to provide a delivery pressure exceeding each corresponding selected operating pressure of the combustor.

22. An apparatus for direct contact steam generation comprising a combustor constructed and arranged to be operatively connected to a steam generator, wherein the combustor is constructed and arranged to be selectively operable at a pressure exceeding atmospheric pressure, and comprises

(i) a first combustor end and a second combustor end;

(ii) a combustor wall comprising an outer wall and a refractory liner having an inner surface defining a combustion space;

(iii) a burner proximate the first combustor end;

(iv) at least a first fuel inlet proximate the first combustor end and constructed and arranged to deliver a first fuel to the burner at a delivery pressure exceeding atmospheric pressure;

(v) at least one oxidant inlet proximate the first combustor end and constructed and arranged to deliver a supply of oxygen to the burner at a delivery pressure exceeding atmospheric pressure;

(vi) a plurality of fluid inlets operatively connected to the combustion space and constructed and arranged to deliver a supply of a fluid including water at a delivery pressure exceeding atmospheric pressure; and

(vii) an outlet region proximate the second combustor end and having a flue gas outlet and a combustor residue outlet;

wherein the flue gas outlet is constructed and arranged to deliver a stream of flue gas to the steam generator for direct contact with a steam generation fluid including water to generate a steam product.

23. An apparatus according to claim 22, wherein the supply of fluid includes at least one hydrocarbon material.

24. An apparatus according to claim 22 or claim 23, wherein the refractory liner comprises a set of cooling tubes, and at least one cooling fluid inlet operatively connected to the set of cooling tubes and at least one cooling fluid outlet operatively connected to the set of cooling tubes.

25. An apparatus according to any one of claims 22 to 24, wherein the apparatus further comprises an air separation unit constructed and arranged to be operatively coupled to the at least one oxidant inlet.

26. An apparatus according to any one of claims 22 to 25, wherein the combustor further comprises at least one wash fluid inlet constructed and arranged to selectively deliver wash fluid into the combustor.

27. An apparatus according to claim 26, wherein the combustor comprises at least two wash fluid inlets, constructed and arranged to deliver the wash fluid to contact different surfaces within the combustor including the inner surface of the refractory liner and an inner surface of a region proximate the second combustor end.

28. An apparatus according to any one of claims 22 to 27, wherein the combustor further comprises a water inlet proximate the first combustor end and constructed and arranged to deliver water to the burner at a delivery pressure exceeding atmospheric pressure.

29. An apparatus according to any one of claims 22 to 28, wherein the combustor further comprises a steam inlet proximate the first combustor end, and the steam delivery means comprises a recirculation means constructed and arranged to selectively deliver part of the steam output to the steam inlet.

30. An apparatus according to any one of claims 22 to 29, wherein the combustor further comprises at least a second fuel inlet proximate the first combustor end.

31. An apparatus according to any one of claims 22 to 30, wherein the fuel delivered to each fuel inlet is selected from the group consisting of a liquid fuel, a gaseous fuel and a solid fuel and mixtures thereof

32. An apparatus according to claim 31, wherein the solid fuel is a slurry comprising a liquid and at least one of bitumen, asphaltene, coal, and petroleum coke.

33. An apparatus according to claim 31, wherein the solid fuel is a slurry and comprises an emulsifier.

34. An apparatus according to any one of claims 22 to 33, wherein the outlet region of the combustor comprises a combustor residue grinder.

35. An apparatus according to any one of claims 22 to 34, wherein the combustor has an operable pressure range of between 3 bar and 175 bar, and each fuel inlet, each oxidant inlet and each fluid inlet and each steam generation fluid inlet is constructed and arranged to provide a delivery pressure exceeding each corresponding selected operating pressure of the combustor.

36. A method of direct contact steam generation comprising the steps of

(a) providing

(i) a combustor having a burner and a refractory wall defining a combustion space and operable at a combustor operating pressure exceeding atmospheric pressure;

and

(ii) a steam generator operatively connected to the combustor and having an upper region, a lower region and an intermediate region;

(b) performing a pre-heating process at ambient pressure to raise the temperature of the refractory wall to a selected temperature;

(c) delivering a fuel and a supply of oxygen to the burner at a pressure exceeding a selected combustor operating pressure;

(d) burning the fuel and oxygen at the selected combustor operating pressure and substantially concurrently delivering to the combustion space a supply of a fluid including water at a pressure exceeding the selected combustor operating pressure to produce a stream of flue gas and a combustion residue;

(e) delivering the stream of flue gas to the lower region of the steam generator and substantially concurrently delivering to the upper region a supply of steam generation fluid including water at a pressure exceeding the selected combustor operating pressure;

(f) allowing the flue gas to contact the steam generation fluid to produce a stream of generated steam; and

(g) removing the stream of generated steam from the steam generator.

37. A method according to claim 36, wherein the selected combustor operating pressure is at least 3 bar.

38. A method according to claim 37, further comprising after step (b) the step of (b.1) providing a supply of nitrogen to the combustor to attain the selected combustor operating pressure, and the burning in step (d) maintains the selected combustor operating pressure.

39. A method according to claim 37, wherein the burning in step (d) is performed to attain and maintain the selected combustor operating pressure.

40. A method according to any one of claims 36 to 39, wherein the fuel in step (c) is selected from the group consisting of a liquid fuel, a gaseous fuel and a solid fuel and mixtures thereof.

41. A method according to claim 40, wherein the solid fuel is a slurry including at least one of bitumen, asphaltene, coal, and petroleum coke.

42. A method according to claim 41, wherein the solid fuel is a slurry and comprises an emulsifier.

43. A method according to any one of claims 36 to 42, wherein step (c) further includes providing a supply of water to the burner at a pressure exceeding the selected combustor operating pressure.

44. A method according to any one of claims 36 to 43, wherein in step (d) the fluid includes at least one hydrocarbon material.

45. A method according to any one of claims 36 to 44, wherein the combustor operating pressure is selected from between 3 bar and 175 bar.

46. A method according to any one of claims 36 to 45, wherein the supply of oxygen has a purity of at least 80%.

47. A method according to claim 46, wherein the supply of oxygen has a purity between 90% and 100%.

48. A method according to claim 47, wherein the supply of oxygen has a purity between 95% and 100%.

49. A method according to any one of claims 36 to 48, wherein step (a)(ii) further comprises providing a cleaning zone in the intermediate region of the steam generator.

50. A method according to claim 49, wherein the cleaning zone comprises at least one of a packed bed, a venturi scrubber, a spray chamber and at least one water reservoir.

51. A method according to any one of claims 36 to 49, wherein the steam generation fluid delivered in step (e) further comprises a sorbent comprising an alkali element selected from calcium, magnesium, sodium and potassium.

52. A method according to claim 51, wherein the alkali element is in a compound form selected from a hydroxide and a carbonate.

53. A method according to any one of claims 36 to 52, further comprising after step (f) the step of

(f.1) passing the generated steam through a demisting region.

54. A method according to any one of claims 36 to 53, wherein in step (e) the steam generation fluid comprises water including contaminants.

55. A method according to any one of claims 36 to 54, wherein step (g) further comprises at least one adjusting of quality of the stream of generated steam.

56. A method according to claim 55, wherein the at least one adjusting of quality comprises providing a supply of a secondary liquid including water to the steam output.

57. A method according to any one of claims 36 to 56, wherein step (g) comprises separating the steam output into a primary output and a secondary output, and recirculating at least part of the secondary output to the combustor.

58. A method according to any one of claims 36 to 57, further comprising the steps of

(h.1) selectively periodically removing residue from the combustor;

and

(h.2) selectively periodically removing residue from the steam generator.

59. A method according to any one of claims 36 to 58, wherein steps (d) and (e) further comprise concurrently substantially continuously removing residue from the combustor.

60. A method according to any one of claims 36 to 59, wherein steps (f) and (g) further comprise concurrently substantially continuously removing residue from the steam generator.