Method and apparatus for removing sulfur oxides from gas

• US 10,207,220 B2
• Filed: 04/07/2017
• Issued: 02/19/2019
• Est. Priority Date: 03/15/2017
• Status: Active Grant

• Current Assignee: Jiangnan Environmental Protection Group Inc.
• Original Assignee: Jiangnan Environmental Protection Group Inc.
• Inventors: Luo, Jing, Xu, Changxiang
• Primary Examiner(s): Vanoy, Timothy C
• Application Number:
  US15/481,736
• Publication Number:
  US 20180264402A1
• Time in Patent Office: 683 Days
• CPC Class Codes: B01D 2009/0086 Processes or apparatus therefor
• CPC Class Codes: B01D 2247/04 Regenerating the washing fluid recovering paint spray booth B05B14/462
• CPC Class Codes: B01D 2251/10 Oxidants
• CPC Class Codes: B01D 2252/102 Ammonia
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/406 Ammonia
• CPC Class Codes: B01D 47/06 Spray cleaning
• CPC Class Codes: B01D 51/10 Conditioning the gas to be cleaned
• CPC Class Codes: B01D 53/501 by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
• CPC Class Codes: B01D 53/502 characterised by a specific solution or suspension
• CPC Class Codes: B01D 53/504 characterised by a specific device
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: B01D 9/0018 Evaporation of components of the mixture to be separated
• CPC Class Codes: C01C 1/24 Sulfates of ammonium C01C1/14 takes precedence

Abstract

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Claims

1. An apparatus for cleaning gas, the apparatus comprising:

a chamber that includes;

a gas input;

a first liquid spray array;

a second liquid spray array; and

a demister;

the first liquid spray array and the second liquid spray array being located at different locations within the chamber;

a first source of ammonia bearing liquid having a conduit to the first liquid spray array;

a second source of ammonia bearing liquid having a conduit to the second liquid spray array;

wherein the first source and the second source are configured so that the first source produces ammonia bearing liquid that has a different sulfur absorbing capacity than that produced by the second source.

2. The apparatus of claim 1 wherein the first source produces ammonia bearing liquid having an ammonia concentration that is different from the ammonia concentration of the liquid produced by the second source.

3. The apparatus of claim 1 wherein the ammonia bearing liquid of the first source has a pH greater than 4.6.

4. The apparatus of claim 1 wherein the chamber is configured to be maintained at an operating temperature between 30°

C. (86°

F.) and 70°

C. (158°

F.).

5. The apparatus of claim 1 wherein the demister is within the chamber.

6. The apparatus of claim 1 wherein the spray array includes a pattern of cone-shaped sprays that together are angled consistent with reaching inner walls of a vessel having a width no less than 110% the maximum horizontal width of the chamber.

7. The apparatus of claim 1 wherein the spray arrays, in aggregate, are configured to deliver no less than 0.2 L of liquid per cubic meter (1.5 gallon liquid per 1000 cubic feet) of gas flow volume.

8. The apparatus of claim 1 further comprising a particle control chamber, the particle control chamber:

situated downstream from, and in gaseous communication with, the chamber;

separated from the chamber by a liquid-collector that allows vapor to pass downstream; and

including;

a washing spray array; and

a conduit connecting the washing spray array to a particle washing liquid source.

9. The apparatus of claim 8 wherein:

the demister is a first demister; and

the particle control chamber includes a second demister.

10. The apparatus of claim 9 wherein the second demister is a baffle plate type.

11. The apparatus of claim 9 wherein the second demister is a ridge type.

12. The apparatus of claim 9 wherein the second demister is a packing type.

13. The apparatus of claim 9 wherein the second demister includes a wire-mesh type.

14. The apparatus of claim 9 wherein the second demister includes one or more of a baffle plate type, a ridge type, a packing type and a wire-mesh type.

15. The apparatus of claim 8 wherein the particle control chamber is configured to be maintained at a temperature between 30°

C. (86°

F.) and 65°

C. (149°

F.).

16. The apparatus of claim 1 wherein the first and second sources are in fluid communication with an inlet that is configured to receive the liquid from the first and second spray arrays.

17. The apparatus of claim 1 further comprising a pre-washing chamber upstream from the gas input and in gaseous communication with the gas input, the pre-washing chamber including a temperature reducing spray array.

18. The apparatus of claim 17 wherein the pre-washing chamber is configured to be maintained at a temperature between 35°

C. (95°

F.) and 80°

C. (176°

F.).

19. The apparatus of claim 17 further comprising a crystallization basin that is located at the bottom of the pre-washing chamber and positioned downstream from a spray array of the spray arrays.

20. The apparatus of claim 1 further comprising:

a pre-washing chamber upstream from the chamber; and

a particle control chamber downstream from the chamber;

wherein;

the pre-washing chamber and the particle control chamber are in gaseous communication with the chamber; and

the pre-washing chamber, the particle control chamber, and the chamber are all positioned within a tower.

21. The apparatus of claim 20 further comprising a crystallization basin that is disposed exterior to the pre-washing chamber.

22. The apparatus of claim 21 wherein the crystallization basin holds a liquid that contains a sulfur oxide and has a pH less than 6.

23. The apparatus of claim 1 further comprising an oxidation tank disposed in a tower.

24. The apparatus of claim 1 further comprising:

a pre-washing chamber upstream from the chamber; and

a particle control chamber downstream from the chamber;

wherein;

the pre-washing chamber and the particle control chamber are in gaseous communication with the chamber; and

the pre-washing chamber, the particle control chamber, and the chamber are distributed among more than one tower.

25. The apparatus of claim 1 further comprising a crystallization basin that is positioned downstream from a spray array of the spray arrays.

26. The apparatus of claim 25 wherein the crystallization basin holds a liquid that contains a sulfur oxide and has a pH less than 5.5.

27. The apparatus of claim 1 further comprising:

a crystallization basin that is positioned downstream from a spray array of the spray arrays;

and a conduit that extends from the crystallization basin to a solid-liquid separation device.

28. The apparatus of claim 1 further comprising an oxidizing chamber in fluidic communication with the chamber via an oxidizing chamber conduit.

29. The apparatus of claim 28 wherein the oxidizing chamber includes the first source and the second source.

30. The apparatus of claim 29 in which the oxidizing chamber comprises 2-8 gas-liquid contactors.

31. The apparatus of claim 29 wherein the oxidizing chamber is configured to provide for a fraction of the ammonia bearing liquid a residence time within the oxidizing chamber of at least 20 minutes.

32. The apparatus of claim 28 further comprising:

an oxidizing gas input to the oxidizing chamber; and

a gas-liquid contactor inside the oxidizing chamber and positioned to be in gaseous communication with the oxidizing gas input and in fluidic communication with the oxidizing chamber conduit.

33. The apparatus of claim 32 in which the gas-liquid contactor includes a structured packing.

34. The apparatus of claim 32 in which the gas-liquid contactor comprises a random packing.

35. The apparatus of claim 32 in which the gas-liquid contactor comprises a perforated plate.

36. The apparatus of claim 32 in which the gas-liquid contactor comprises a bubble cap.

37. The apparatus of claim 32 in which the gas-liquid contactor comprises an aeration head.

38. The apparatus of claim 32 further comprising a gas delivery device that is configured to deliver through the gas input no less than 20% more than the minimum stoichiometric amount required to oxidize the ammonia bearing liquid for which the gas-liquid contactor is configured to contact.

39. The apparatus of claim 1 wherein the ammonia bearing liquid of the second source has a pH greater than 4.6.

40. An apparatus for cleaning gas, the apparatus comprising:

a chamber that includes;

a gas input;

a first liquid spray array;

a second liquid spray array;

the first liquid spray array and the second liquid spray array being located at different locations within the chamber;

a particle control chamber that includes a demister;

a first source of ammonia bearing liquid having a conduit to the first liquid spray array; and

a second source of ammonia bearing liquid having a conduit to the second liquid spray array;

wherein the first source and the second source are configured so that the first source produces ammonia bearing liquid that has a different sulfur absorbing capacity than that produced by the second source.

41. The apparatus of claim 40 wherein the first source produces ammonia bearing liquid having an ammonia concentration that is different from the ammonia concentration of the liquid produced by the second source.

42. The apparatus of claim 40 wherein the ammonia bearing liquid of the first source has a pH greater than 4.6.

43. The apparatus of claim 40 wherein the chamber that includes the spray arrays is configured to be maintained at an operating temperature between 30°

C. (86°

F.) and 70°

C. (158°

F.).

44. The apparatus of claim 40 wherein the demister is a first demister, and further comprising a second demister within the chamber that includes the spray arrays.

45. The apparatus of claim 40 wherein the spray array includes a pattern of cone-shaped sprays that together are angled consistent with reaching inner walls of a vessel having a width no less than 110% the maximum horizontal width of the chamber that includes the spray arrays.

46. The apparatus of claim 40 wherein the spray arrays, in aggregate, are configured to deliver no less than 0.2 L of liquid per cubic meter (1.5 gallon liquid per 1000 cubic feet) of gas flow volume.

47. The apparatus of claim 40 wherein the particle control chamber is:

situated downstream from, and in gaseous communication with, the chamber; and

separated from the chamber by a liquid-collector that allows vapor to pass downstream; and

includes;

a washing spray array; and

a conduit connecting the washing spray array to a particle washing liquid source.

48. The apparatus of claim 47 wherein the demister is a baffle plate type.

49. The apparatus of claim 47 wherein the demister is a ridge type.

50. The apparatus of claim 47 wherein the demister is a packing type.

51. The apparatus of claim 47 wherein the demister includes a wire-mesh type.

52. The apparatus of claim 47 wherein the demister includes one or more of a baffle plate type, a ridge type, a packing type and a wire-mesh type.

53. The apparatus of claim 40 wherein the particle control chamber is configured to be maintained at a temperature between 30°

C. (86°

F.) and 65°

C. (149°

F.).

54. The apparatus of claim 40 wherein the first and second sources are in fluid communication with an inlet that is configured to receive the liquid from the first and second spray arrays.

55. The apparatus of claim 40 further comprising a pre-washing chamber upstream from the gas input and in gaseous communication with the gas input, the pre-washing chamber including a temperature reducing spray array.

56. The apparatus of claim 55 wherein the pre-washing chamber is configured to be maintained at a temperature between 35°

C. (95°

F.) and 80°

C. (176°

F.).

57. The apparatus of claim 55 further comprising a crystallization basin that is located at the bottom of the pre-washing chamber and positioned downstream from a spray array of the spray arrays.

58. The apparatus of claim 40 further comprising a pre-washing chamber upstream from the chamber;

wherein;

the particle control chamber is situated downstream from the chamber;

the pre-washing chamber and the particle control chamber are in gaseous communication with the chamber; and

the pre-washing chamber, the particle control chamber, and the chamber are all positioned within a tower.

59. The apparatus of claim 58 further comprising a crystallization basin that is disposed exterior to the pre-washing chamber.

60. The apparatus of claim 59 wherein the crystallization basin holds a liquid that contains a sulfur oxide and has a pH less than 6.

61. The apparatus of claim 40 further comprising an oxidation tank disposed in a tower.

62. The apparatus of claim 40 further comprising a pre-washing chamber upstream from the chamber;

wherein;

the particle control chamber is situated downstream from the chamber;

the pre-washing chamber and the particle control chamber are in gaseous communication with the chamber; and

the pre-washing chamber, the particle control chamber, and the chamber are distributed among more than one tower.

63. The apparatus of claim 40 further comprising a crystallization basin that is positioned downstream from a spray array of the spray arrays.

64. The apparatus of claim 63 wherein the crystallization basin holds a liquid that contains a sulfur oxide and has a pH less than 5.5.

65. The apparatus of claim 40 further comprising:

a crystallization basin that is positioned downstream from a spray array of the spray arrays; and

a conduit that extends from the crystallization basin to a solid-liquid separation device.

66. The apparatus of claim 40 further comprising an oxidizing chamber in fluidic communication with the chamber via an oxidizing chamber conduit.

67. The apparatus of claim 66 wherein the oxidizing chamber includes the first source and the second source.

68. The apparatus of claim 67 in which the oxidizing chamber comprises 2-8 gas-liquid contactors.

69. The apparatus of claim 67 wherein the oxidizing chamber is configured to provide for a fraction of the ammonia bearing liquid a residence time within the oxidizing chamber of at least 20 minutes.

70. The apparatus of claim 66 further comprising:

an oxidizing gas input to the oxidizing chamber; and

a gas-liquid contactor inside the oxidizing chamber and positioned to be in gaseous communication with the oxidizing gas input and in fluidic communication with the oxidizing chamber conduit.

71. The apparatus of claim 70 in which the gas-liquid contactor includes a structured packing.

72. The apparatus of claim 70 in which the gas-liquid contactor comprises a random packing.

73. The apparatus of claim 70 in which the gas-liquid contactor comprises a perforated plate.

74. The apparatus of claim 70 in which the gas-liquid contactor comprises a bubble cap.

75. The apparatus of claim 70 in which the gas-liquid contactor comprises an aeration head.

76. The apparatus of claim 70 further comprising a gas delivery device that is configured to deliver through the gas input no less than 20% more than the minimum stoichiometric amount required to oxidize the ammonia bearing liquid for which the gas-liquid contactor is configured to contact.

77. The apparatus of claim 40 wherein the ammonia bearing liquid of the second source has a pH greater than 4.6.