INTEGRATED AMMONIA-BASED DESULFURIZATION AND DECARBONIZATION APPARATUS AND METHOD
20220362706 · 2022-11-17
Inventors
Cpc classification
Y02P20/151
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02A50/20
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C05C9/00
CHEMISTRY; METALLURGY
B01D53/1481
PERFORMING OPERATIONS; TRANSPORTING
C05C3/00
CHEMISTRY; METALLURGY
Y02C20/40
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C02F2103/18
CHEMISTRY; METALLURGY
International classification
B01D53/18
PERFORMING OPERATIONS; TRANSPORTING
C05C3/00
CHEMISTRY; METALLURGY
C05C9/00
CHEMISTRY; METALLURGY
Abstract
Apparatus and methods for desulfurization and decarbonization of a process gas containing sulfur oxides and CO.sub.2. Ammonia may be used as a desulfurizing and decarbonizing agent. The gas may enter a desulfurization apparatus for desulfurization, and to produce an ammonium sulfate fertilizer. The desulfurized gas may enter a decarbonization apparatus to remove carbon dioxide in the gas, and to produce an ammonium bicarbonate fertilizer. The decarbonized gas may contain free ammonia. The decarbonized gas may be washed with a desulfurization circulating fluid and then with water. The washing fluid may be returned to the desulfurization apparatus for use as an absorbing agent for desulfurization. Acidic desulfurization circulating fluid may be used to wash ammonia, thereby achieving a high ammonia washing efficiency, and a low ammonia slip during the decarbonization process.
Claims
1. A desulfurization and decarbonization method using ammonia to remove sulfur oxides and CO.sub.2 in process gas that is fed into a desulfurization apparatus, the method comprising: in order: 1) removing, using desulfurization circulating fluid, SO.sub.2 from the process gas. 2) removing, using a decarbonization circulating fluid, CO.sub.2 from the process gas; and 3) removing, using desulfurization circulating fluid, free ammonia from the process gas; and returning the desulfurization circulating fluid to the desulfurization apparatus.
2. The method of claim 1 further comprising producing fertilizer.
3. The method of claim 2 wherein the fertilizer includes ammonium sulfate.
4. The method of claim 2 wherein the fertilizer includes ammonium bicarbonate fertilizers.
5. The method of claim 1 wherein the removing CO.sub.2 removes from 30-98% of the CO.sub.2.
6. The method of claim 1 further comprising: producing from the decarbonization circulating fluid ammonium bicarbonate fertilizer; and regenerating gaseous CO.sub.2 from the decarbonization circulating fluid; wherein the regenerating is performed in a regeneration system having a tower that includes a tower bottom and a tower top.
7. The method of claim 6 wherein an operating temperature at the tower bottom is in a range from 90-150° C.
8. The method of claim 7 wherein the range is from 100-130° C.
9. The method of claim 6 wherein an operating temperature at the tower top is in a range from 6-100° C.
10. The method of claim 9 wherein the range is from 70-90° C.
11. The method of claim 6 wherein a regeneration pressure at the tower bottom is in a range from 0.2-0.7 MPa.
12. The method of claim 11 wherein the range is from 0.3-0.5 MPa.
13. The method of claim 6 further comprising flowing gas in the tower at a gas velocity in a range from 0.2-3 m/s.
14. The method of claim 13 wherein the range is 0.3-2 m/s.
15. The method of claim 1 further comprising producing from the decarbonization circulating fluid ammonium bicarbonate fertilizer.
16. The method of claim 1 further comprising producing, from gaseous CO.sub.2 removed from the process gas, a downstream product.
17. The method of claim 16 wherein the downstream product includes urea.
18. The method of claim 16 wherein the downstream product includes soda ash.
19. The method of claim 16 wherein the downstream product includes sodium bicarbonate.
20. The method of claim 16 wherein the downstream product includes polycarbonate.
21. The method of claim 16 wherein the downstream product includes CO.sub.2 gas fertilizer.
22. The method of claim 16 wherein the downstream product includes potassium bicarbonate.
23. The method of claim 16 wherein the downstream product includes food-grade CO.sub.2.
24. The method of claim 1 further comprising recovering, using gaseous CO.sub.2 removed from the process gas, oil.
25. The method of claim 24 further comprising sequestering gaseous CO.sub.2 removed from the process gas.
26. The method of claim 25 wherein the sequestering includes performing marine sequestration.
27. The method of claim 25 wherein the sequestering includes performing underground sequestration.
28. The method of claim 1 further comprising sequestering gaseous CO.sub.2 removed from the process gas.
29. The method of claim 28 wherein the sequestering includes performing marine sequestration.
30. The method of claim 28 wherein the sequestering includes performing underground sequestration.
31. The method of claim 1 further comprising: between step 2) and step 3), removing, using process water, free ammonia from the process gas; and, after step 3), removing, using process water, free ammonia from the process gas.
32. The method of claim 1 further comprising, after step 3), removing, using process water, free ammonia from the process gas.
33. The method of claim 1 wherein: the desulfurization circulating fluid comprises: a concentrated circulating fluid and; an absorbing circulating fluid; the concentrated circulating fluid has: ammonium sulfite at a concentration of 0-0.2%; and ammonium sulfate at a concentration of 10-60%; and the absorbing circulating fluid has: ammonium sulfite at a concentration of 0.1-3%; and ammonium sulfate at a concentration of 10-38%.
34. The method of claim 33 wherein: the concentrated circulating fluid has a pH of 1-6; and the absorbing circulating fluid has a pH of 4.5-6.5.
35. (canceled)
36. The method of claim 33 wherein: the concentrated circulating fluid has a pH of 2-4.5; and the absorbing circulating fluid has a pH of 4.8-6.2.
37. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 7-13; ammonium bicarbonate at a concentration of 3-40%; and an NH.sub.3/CO.sub.2 molar ratio of 0.6-4.
38-42. (canceled)
43. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 7.5-11; ammonium bicarbonate at a concentration of 3-40%; and an NH.sub.3/CO.sub.2 molar ratio of 0.6-4.
44-48. (canceled)
49. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 8-9.5; ammonium bicarbonate at a concentration of 3-40%; and an NH.sub.3/CO.sub.2 molar ratio of 0.6-4.
50-51. (canceled)
52. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 8-9.5; ammonium bicarbonate at a concentration of 10-22%; and an NH.sub.3/CO.sub.2 molar ratio of 0.6-4.
53. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 8-9.5; ammonium bicarbonate at a concentration of 10-22%; and an NH.sub.3/CO.sub.2 molar ratio of 1.2-3.
54. The method of claim 1 wherein the decarbonization circulating fluid has: a pH of 8-9.5; ammonium bicarbonate at a concentration of 10-22%; and an NH.sub.3/CO.sub.2 molar ratio of 2-2.5.
55. The method of claim 1 wherein: the desulfurization includes absorbing SO.sub.2 at a temperature in a range from 5-55° C.; and the decarbonization includes absorbing CO.sub.2 at a temperature in a range from 0-45° C.
56-58. (canceled)
59. The method of claim 1 wherein: the desulfurization includes absorbing SO.sub.2 at a temperature in a range from 15-50° C.; and the decarbonization includes absorbing CO.sub.2 at a temperature in a range from 5-40 CC.
60-62. (canceled)
63. The method of claim 1 wherein: the desulfurization includes absorbing SO.sub.2 at a temperature in a range from 20-40° C.; and the decarbonization includes absorbing CO.sub.2 at a temperature in a range from 10-30° C.
64. Apparatus for implementing the method of claim 1, the apparatus comprising: an ammonia-based desulfurization functional area that is configured to apply a desulfurizing agent to a process gas; an ammonia-based decarbonization functional area that is configured to apply a decarbonizing agent to the process gas; an ammonia washing functional area; an ammonium sulfate post-processing system; and an ammonium bicarbonate post-processing system; wherein: the desulfurizing agent is ammonium; the decarbonizing agent is ammonium; the desulfurization functional area is further configured to: receive the process gas; and desulfurize the process gas; the decarbonization functional area is further configured to: receive the process gas after the process gas exits the desulfurization functional area; remove carbon dioxide from the process gas; and produce an ammonium bicarbonate-containing material; the ammonia washing functional area is configured to: receive process gas after the process gas exits the decarbonization functional area; wash the process gas with a desulfurization circulating fluid; and, then, wash the process gas with process water; and the desulfurization functional area is further configured to: receive the process gas after the process gas exits the ammonia washing functional area; receive the process water after the process water exits the ammonia washing functional area; spray the process gas and the process water as an absorbing agent for desulfurization; and receive ammonium sulfate-containing ammonium bicarbonate solution after the ammonium bicarbonate solution exits the decarbonization functional area.
65. The apparatus of claim 64 wherein the process gas includes free ammonia.
66. The apparatus of claim 64 wherein: the ammonia washing functional area is further configured to wash the process gas with the process water before washing the process gas with the desulfurization circulating fluid; and the ammonia-based desulfurization functional area, the ammonia-based decarbonization functional area, and the ammonia washing functional area are disposed in a tower.
67. The apparatus of claim 64 wherein the desulfurization functional area includes: a cooling and concentrating segment that includes a first spraying layer; an absorbing segment that: includes a second spraying layer; and is in fluid communication with the cooling and concentrating segment via a first device that is configured to allow gas to pass; and a particulate removing segment that is in fluid communication with the absorbing segment via a second device that is configured to allow gas to pass; wherein each of the segments: includes at least one spraying layer; and is in fluid communication with another segment via a device that is configured to allow gas to pass.
68. The apparatus of claim 67 further comprising, in the particulate removing segment: a first washing part configured to wash with concentrated, circulating ammonium sulfate-containing solution; and a second washing part that: is configured to wash with dilute, circulating ammonium sulfate-containing solution; and is in fluid communication with the first washing part via a device that allows gas to pass.
69. The apparatus of claim 68 wherein: the first part is further configured to maintain: an ammonium sulfate concentration of the concentrated ammonium sulfate-containing solution in a range that is 10-38%; and a pH of the concentrated ammonium sulfate-containing solution in a range that is 2.5-7.5; and the second part is further configured to maintain: an ammonium sulfate concentration of the dilute ammonium sulfate-containing solution in a range that is 0-5%; and a pH of the dilute ammonium sulfate-containing solution in a range that is 3-7.
70-75. (canceled)
76. The apparatus of claim 68 wherein: the first part is further configured to maintain: an ammonium sulfate concentration of the concentrated ammonium sulfate-containing solution in a range that is 12-30%; and a pH concentrated ammonium sulfate-containing solution in a range that is 3-5.5; and the second part is further configured to maintain: an ammonium sulfate concentration of the dilute ammonium sulfate-containing solution in a range that is 0.02-2%; and a pH of the dilute ammonium sulfate-containing solution in a range that is 3-7.
77. The apparatus of claim 67 wherein the desulfurization functional area includes a cooling apparatus that is configured to maintain a temperature of process gas in a range that is 5-55° C.
78. The apparatus of claim 77 wherein the range is 15-50° C.
79. The apparatus of claim 77 wherein the range is 20-40° C.
80. The apparatus of claim 67 wherein the decarbonization functional area includes a cooling apparatus that is configured to maintain a temperature of process gas in a range that is 0-45° C.
81. The apparatus of claim 80 wherein the range is 5-40° C.
82. The apparatus of claim 80 wherein the range is 10-30° C.
83. The apparatus of claim 77 further comprising a circulating pipeline configured to transport desulfurization circulating fluid; wherein: the cooling apparatus is: arranged on the circulating pipeline; and configured to: cool: the circulating desulfurization fluid; and the process gas; and circulate water as a coolant.
84. The apparatus of claim 83 further comprising a process gas conduit; wherein the cooling apparatus is: arranged on the process gas conduit; and configured to cool the process gas.
85. The apparatus of claim 84 wherein the cooling apparatus is further configured to circulate water as a coolant.
86. The apparatus of claim 64 wherein: the ammonia washing functional area is further configured to: (A) receive desulfurization fluid from the ammonia-based desulfurization functional area; using the desulfurization fluid, absorb ammonia from post-decarbonization process gas; and, then, return the desulfurization fluid to the desulfurization functional area; and (B) collect aqueous solution during ammonia washing; provide the aqueous solution to the desulfurization functional area; the desulfurization functional area is further configured to use: the returned desulfurization fluid to desulfurize the process gas; and the provided aqueous solution for particle removal; and a pH of ammonium sulfate washing solution is controlled at 2.5-7.5.
87. The apparatus of claim 86 wherein an ammonia concentration in an ammonia washing circulating solution in the ammonia washing functional area is controlled at 0-5%.
88. The apparatus of claim 86 wherein an ammonia concentration in an ammonia washing circulating solution in the ammonia washing functional area is controlled at 0-1%.
89. The apparatus of claim 68 further comprising: a purification membrane separation apparatus; and a conduit; wherein: the particulate removing segment is configured to provide dilute ammonium sulfate solution; the purification membrane separation apparatus is configured to: receive the dilute ammonium sulfate solution; and produce purified water from the dilute ammonium sulfate solution; and the conduit is configured to convey a fraction of the purified water to the ammonia washing functional area.
90. The apparatus of claim 89 wherein the ammonia washing functional area is further configured to use the purified water to replenish circulating washing water in the ammonia washing functional area.
91. The apparatus of claim 90 wherein the ammonia washing functional area is further configured to use the purified water to control a concentration of ammonia in the washing water.
92. The apparatus of claim 90 wherein the ammonia washing functional area is further configured to use the purified water to control a concentration of ammonium sulfate solution for return to the desulfurization functional area.
93. The apparatus of claim 89 further comprising, when the conduit is a first conduit, a second conduit that is configured to convey concentrated solution to a desulfurization absorption area of the desulfurization functional area.
94. The apparatus of claim 64 further comprising an ammonium bicarbonate post-processing system; wherein: the decarbonization functional area is further configured to produce an ammonium bicarbonate slurry; and the ammonium bicarbonate post-processing system is configured to: remove solution from the slurry; pack the slurry into a product; and and return the solution to the decarbonization functional area.
95. The apparatus of claim 94 further comprising a CO.sub.2 regeneration system that is configured to: heat ammonium bicarbonate from the decarbonization functional area to produce: CO.sub.2; and an ammonia solution; and provide the ammonia solution to the decarbonization functional area.
96. The apparatus of claim 64 wherein the ammonia-based desulfurization functional area is further configured to control: a gas velocity at 0.5-5 m/s; a circulating fluid spraying density for a spray layer at 4-100 m.sup.3/m.sup.2-h; a circulating fluid temperature at 5-55° C.; and a circulating fluid pH at 1-7.
97-102. (canceled)
103. The apparatus of claim 64 wherein the ammonia-based desulfurization functional area is further configured to control: a gas velocity at 2-4 m/s; a circulating fluid spraying density for a spray layer at 8-80 m.sup.3/m.sup.2-h; a circulating fluid temperature at 20-40° C.; and a circulating fluid pH at 1-7.
104. The apparatus of claim 64 wherein the ammonia-based decarbonization functional areas is further configured to control: a gas velocity at 2-4 m/s; a gas temperature at 5-40° C.; and circulating fluid pH at 7-11.
105. The apparatus of claim 64 wherein the ammonia-based decarbonization functional areas is further configured to control: a gas velocity at 2-4 m/s; a gas temperature at 10-30° C.; and circulating fluid pH at 7-11.
106. The apparatus of claim 64 wherein the ammonia washing functional area is further configured to control: a velocity at 0.25-5 m/s; a temperature at 0-50° C.; and a circulating fluid pH at 3-10.
107. The apparatus of claim 64 wherein the ammonia washing functional area is further configured to control: a velocity at 0.25-5 m/s; a temperature at 3-40° C.; and a circulating fluid pH at 3-10.
108. The apparatus of claim 64 further comprising a heat pump system that that is configured to: receive water, at a temperature from 3-25° C., from a chilled water cooler that is in thermal communication with the CO.sub.2; and return the chilled water to the chilled water cooler.
109. The apparatus of claim 64 further comprising a heat pump system that that is configured to: receive water, at a temperature from 5-10° C., from a chilled water cooler that is in thermal communication with the CO.sub.2; and return the chilled water to the chilled water cooler.
110. The apparatus of claim 64 further comprising a CO.sub.2 regeneration tower that is configured to: extract CO.sub.2 from the process gas; and maintain: a temperature of the process gas at a bottom of the tower at 90-150° C.; a temperature of the process gas at a top of the tower at 6-100° C.; a pressure of the process gas at a bottom of the tower at 0.2-0.7 MPa; and a gas velocity at 0.2-3 m/s.
111-124. (canceled)
125. The apparatus of claim 64 further comprising a CO.sub.2 regeneration tower that is configured to: extract CO.sub.2 from the process gas; and maintain: a temperature of the process gas at a bottom of the tower at 100-130° C.; a temperature of the process gas at a top of the tower at 70-90° C.; a pressure of the process gas at a bottom of the tower at 0.3-0.5 MPa; and a gas velocity at 0.3-2 m/s.
126. The apparatus of claim 64 further comprising a process water inlet that is disposed on an upper part of a CO.sub.2 regeneration tower.
127. The apparatus of claim 64 further comprising: a solution heat exchanger; a reboiler; a circulating water cooler; a chilled water cooler in fluid communication with the circulating water cooler; a CO.sub.2 buffer tank, and a CO.sub.2 compressor, wherein: a decarbonization circulating pump provides a fraction of the bicarbonate-containing material, via the solution heat exchanger, to a CO.sub.2 regeneration tower; the chilled water cooler is configured to receive CO.sub.2, via the circulating water cooler, from a top of the tower; and the CO.sub.2 compressor is configured to: receive CO.sub.2, via the CO.sub.2 buffer tank, from the chilled water cooler, compress the CO.sub.2; and discharge the CO.sub.2.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
[0019]
[0020]
[0021]
[0022] In
DETAILED DESCRIPTION
[0078] Apparatus and methods for ammonia-based desulfurization and decarbonization are provided. The apparatus and methods may use ammonia to remove sulfur oxides and CO.sub.2 to produce ammonium sulfate and ammonium bicarbonate fertilizers. The apparatus may include one or more of an ammonia-based desulfurization functional area, an ammonia-based decarbonization functional area, an ammonia washing functional area, an ammonium sulfate post-processing system, and an ammonium bicarbonate post-processing system. Ammonia may be used as a desulfurizing agent and a decarbonizing agent. A gas may first enter the desulfurization functional area for desulfurization to produce ammonium sulfate fertilizer. At least part of the desulfurization may be performed in a tower associated with the desulfurization functional area. The desulfurized gas may enter the decarbonization functional area for removal of carbon dioxide for the production of ammonium bicarbonate fertilizer. At least part of the decarbonization may be performed in a tower associated with the decarbonization functional area. The decarbonized gas may include free ammonia. The decarbonized gas may enter the ammonia washing functional area for washing with an ammonium sulfate solution for desulfurization, and then with water. At least part of the washing may be performed in a tower associated with the ammonia washing functional area. After the washing, the ammonia-containing ammonium sulfate solution and aqueous solution may be returned to the desulfurization functional area, where they may serve as an absorbing agent for desulfurization. The above functional areas may be combined in one tower or more than one tower. The above functional areas may be disposed in one tower or more than one tower. The above functional areas may include towers, such as a desulfurization tower associated with the desulfurization functional area, a decarbonization tower associated with the decarbonization functional area, and an ammonia washing tower associated with the ammonia washing functional area. The desulfurization functional area may be divided into a plurality of segments. The segments may include one or more of a cooling and concentrating segment, an absorbing segment, and a particulate removing segment. Each segment may be provided with at least one spraying layer. A device/part may be arranged between segments to allow a gas to pass. The particulate removing segment may be divided into two parts: for spray washing in the first part, an ammonium sulfate-containing concentrated solution may be used for circulated washing. An ammonium sulfate-containing dilute solution may be used in the second part for circulated washing. A device/part may be arranged between the two parts to allow a gas to pass. The concentration of the concentrated ammonium sulfate solution in the first part may be controlled at 5-40%, preferably 10-30%, and the pH may be controlled at 3-7, preferably 3-5.5. The concentration of the dilute ammonium sulfate solution in the second part may be controlled at 0.02-10%, preferably 0.03-5%, and the pH may be controlled at 3-7.
[0079] An ammonia-based desulfurization and decarbonization method may include the following steps, which may be performed in the order below:
[0080] 1) using a desulfurization circulating fluid to remove part of SO.sub.2 in the process gas;
[0081] 2) using a decarbonization circulating fluid to remove part of CO.sub.2 in the process gas; and
[0082] 3) using a desulfurization circulating fluid to remove part of free ammonia in the process gas, and returning the desulfurization circulating fluid to a desulfurization apparatus.
[0083] Step 1) and step 2) may be followed by production of ammonium sulfate and ammonium bicarbonate fertilizers.
[0084] The CO.sub.2 removal efficiency in step 2) may be in the range 30-98%.
[0085] Part of the decarbonization circulating fluid may be sent to an ammonium bicarbonate post-processing apparatus to produce ammonium bicarbonate fertilizer, and/or part of the decarbonization circulating fluid may be sent to a CO.sub.2 regeneration apparatus to obtain gaseous CO.sub.2. The CO.sub.2 regeneration apparatus may include a regeneration tower. Part of the CO.sub.2 may be used for one or more of beverage production, enhanced oil recovery, and welding. Part of the CO.sub.2 may be used for production of one or more downstream products including urea, soda ash, sodium bicarbonate, polycarbonate, polyurethane, food-grade CO.sub.2, CO.sub.2 gas fertilizer, potassium bicarbonate, and the like.
[0086] The methods may include performing, between step 2) and step 3), a step 4) that may use process water to remove some or all of the free ammonia that may be present in the process gas. The methods may include performing, after step 3), a step 5) that may use process water to remove some or all of the free ammonia that may be present in the process gas.
[0087] The desulfurization circulating fluid may have a concentrated circulating fluid and an absorbing circulating fluid. The concentrated circulating fluid may have a pH of 1-6. The concentrated circulating fluid may have a pH of 2-4.5. The concentrated circulating fluid may have an ammonium sulfite concentration of 0-0.2%. The concentrated circulating fluid may have an ammonium sulfate concentration of 10-60%. The absorbing circulating fluid may have a pH of 4.5-6.5. The absorbing circulating fluid may have a pH of 4.8-6.2. The absorbing circulating fluid may have an ammonium sulfite concentration of 0.1-3%. The absorbing circulating fluid may have an ammonium sulfate concentration of 10-38%.
[0088] The decarbonization circulating fluid may have a pH of 7-13. The decarbonization circulating fluid may have a pH of 7.5-11. The decarbonization circulating fluid may have a pH of 8-9.5. The decarbonization circulating fluid may have an ammonium bicarbonate concentration of 3-40%. The decarbonization circulating fluid may have an ammonium bicarbonate concentration of 10-22%. The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 0.6-4. The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 1.2-3. The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 2-2.5.
[0089] The desulfurization absorption temperature may be in the range 5-55° C. The desulfurization absorption temperature may be in the range 15-50° C. The desulfurization absorption temperature may be in the range 20-40° C. The decarbonization absorption temperature may be in the range 0-45° C. The decarbonization absorption temperature may be in the range 5-40° C. The decarbonization absorption temperature may be in the range 10-30° C. A heat pump refrigeration technology may be used to provide cooling for cooling the decarbonization circulating fluid and the desulfurization circulating fluid. The temperature of the chilled water obtained by the heat pump may be in the range 3-25° C. The temperature of the chilled water obtained by the heat pump may be in the range 5-10° C.
[0090] Power for the heat pump may include one or more of hot water, steam, and electricity. Circulating water or desalted water may be used as a cold source. When desalted water is used, the desalted water after heat exchange may be sent to a low-temperature coal economizer to lower coal consumption per ton of steam.
[0091] The desulfurization functional area may be provided with a cooling apparatus to control the temperature of desulfurized flue gas in the range 5-55° C. The range may be 20-40° C. The ranges may meet temperature requirements for subsequent decarbonization. The cooling apparatus may be arranged on the circulating pipeline for the desulfurization circulating fluid to cool the desulfurization circulating fluid. After the cooling, the cooled desulfurization circulating fluid may further cool the desulfurized flue gas. A plurality of cooling apparatus may be provided, for example, on the circulating and absorbing pipeline in the absorbing segment and the particulate removing segment. Cooling apparatus may be provided on the water washing pipeline in the particulate removing segment. The washing condensate may be purified through membrane separation. The concentrated solution may enter the desulfurization absorbing area. The clean water may be used as makeup water for ammonia washing or may be used externally.
[0092] The cooling apparatus may be arranged in the process gas pipeline, at the inlet, inside of, or at the outlet of the desulfurization functional area. The circulating water or chilled water may be used as a cooling agent, which may be used individually or may be combined. The desulfurization circulating solution for ammonia washing may be taken from the circulating washing solution of the desulfurization tower and, after the ammonia washing, may be returned to the ammonia-based desulfurization functional area for desulfurization. The pH of the ammonium sulfate washing solution may be controlled at 2.5-7.5. The pH of the ammonium sulfate washing solution may be controlled at 3-5.5.
[0093] The pH for washing the process water may be controlled at 3-7. Part of the water solution absorbed during the ammonia washing circulation may enter, as makeup water, the circulating fluid for the particulate removing segment of the desulfurization tower. The ammonium sulfate concentration in the circulating solution may be controlled at 0-5%. The ammonium sulfate concentration in the circulating solution may be controlled at 0.02-2%.
[0094] Part of the water washing circulating solution may be pumped out and sent to a purification membrane separation apparatus. The produced purified water may be used as makeup water for the desulfurization and washing functional areas to control the ammonia concentration in the washing water and the concentration of the dilute ammonium sulfate solution for desulfurization and washing. The concentrated solution may enter the desulfurization absorption area.
[0095] The decarbonization functional area and the ammonia washing functional area may include one or a combination of a sprayer, a plate, and packed and floating-valve absorption columns.
[0096] The ammonium sulfate slurry produced from desulfurization may enter an ammonium sulfate post-processing system. After solid-liquid separation, wet ammonium sulfate may be dried and packed into an ammonium sulfate product. A wet ammonium sulfate product may be output directly. Solution from the solid-liquid separator may be returned to the desulfurization functional area. If an ammonium sulfate solution is produced, the solution may be evaporated and crystallized to form an ammonium sulfate slurry before entering the solid-liquid separation apparatus.
[0097] The ammonium bicarbonate slurry produced from the decarbonization tower may enter the solid-liquid separation apparatus. The solution may be returned to the decarbonization functional area. The wet ammonium bicarbonate may be dried and packed into a product. A wet ammonium bicarbonate product may be output directly. Part of the ammonium bicarbonate produced from the decarbonization may be heated to produce CO.sub.2 and an ammonia solution. The ammonia-containing solution may be returned to the decarbonization functional area for further use.
[0098] Main parameters of the desulfurization functional area may include: [0099] Empty tower gas velocity controlled at 0.5-5 m/s [0100] Empty tower gas velocity controlled at 2-4 m/s [0101] Circulating fluid spraying density of each layer at 4-100 m.sup.3/m.sup.2.Math.h [0102] Circulating fluid spraying density of each layer at 8-80 m.sup.3/m.sup.2.Math.h [0103] Circulating fluid temperature controlled at 5-55° C. [0104] Circulating fluid temperature controlled at 20-40° C. [0105] Circulating fluid pH controlled at 1-7
[0106] Main parameters of the decarbonization functional area may include: [0107] Empty tower gas velocity controlled at 0.1-5 m/s [0108] Temperature controlled at 5-40° C. [0109] Temperature controlled at 10-30° C. [0110] Circulating fluid pH controlled at 7-11
[0111] Main parameters of the ammonia washing functional area may include: [0112] Empty tower gas velocity controlled at 0.25-5 m/s [0113] Temperature controlled at 0-50° C. [0114] Temperature controlled at 3-40° C. [0115] Circulating fluid pH controlled at 3-10
[0116] A strong acid, such as sulfuric acid, nitric acid, or hydrochloric acid, may be added into the desulfurization functional area and/or the ammonia washing functional area to adjust the pH of the circulating fluid.
[0117] The apparatus may include a heat pump system. Heat pump refrigeration technology may be used to provide cooling capacity for cooling the decarbonization circulating fluid and the desulfurization circulating fluid. The temperature of the chilled water obtained by the heat pump may be in the range 3-25° C. The temperature of the chilled water obtained by the heat pump may be in the range 5-10° C. The chilled water inlet/return pipelines may be connected with some or all chilling heat exchangers.
[0118] The apparatus may include a CO.sub.2 regeneration tower in which regeneration of decarbonization circulating fluid proceeds. CO.sub.2 regeneration tower operating parameters may include: [0119] At tower bottom, a regeneration temperature in the range 90-150° C. [0120] At tower bottom, a regeneration temperature in the range 100-130° C. [0121] At tower top, a regeneration temperature in the range 6-100° C. [0122] At tower top, a regeneration temperature in the range 70-90° C. [0123] At tower bottom, a regeneration pressure in the range 0.2-0.7 MPa [0124] At tower bottom, a regeneration pressure in the range 0.3-0.5 MPa [0125] A regeneration tower gas velocity in the range 0.2-3 m/s [0126] A regeneration tower gas velocity in the range 0.3-2 m/s
[0127] The apparatus may include one or more of a solution heat exchanger, a reboiler, a circulating water cooler, a chilled water cooler, a CO.sub.2 buffer tank, and a CO.sub.2 compressor.
[0128] The circulating pump for the decarbonization tower may output a part of the decarbonization circulating solution to a solution heat exchanger for heat exchange. The solution may then enter the CO.sub.2 regeneration tower. After the tower bottom is heated by steam from the reboiler, CO.sub.2 gas may be collected at the top of the tower. The gas may be subjected to two-stage cooling by the circulating water cooler and the chilled water cooler. The gas may then be sent to the CO.sub.2 buffer tank. After a certain period of buffering, the gas may be sent out for compression by the CO.sub.2 compressor. Condensate may be taken out from the bottom of the reboiler.
[0129] Process water may be added to an upper part of the CO.sub.2 regeneration tower.
[0130] After the CO.sub.2 obtained from regeneration is subjected to gas-liquid separation, part of the gas may be used for production of downstream products or enhanced oil recovery. The downstream products may include one or more of urea, soda ash, sodium bicarbonate, polycarbonate, food-grade CO.sub.2, CO.sub.2 gas fertilizer, potassium bicarbonate, and the like. Part of the gas may be used for one or more of enhanced oil recovery, beverage production, and welding. Part of the gas may be used for marine sequestration or underground sequestration. Separation liquid from the gas-liquid separation may be returned to the CO.sub.2 regeneration tower.
[0131] The apparatus and methods may include interaction between decarbonization and desulfurization processes. The apparatus and methods may include using an acidic desulfurization circulating fluid to wash ammonia. This may help achieve a high ammonia washing efficiency, and may reduce or eliminate ammonia slip during the decarbonization process. Ammonium bicarbonate output, the amount of sequestered CO.sub.2, and the output of CO.sub.2 downstream products may be flexibly adjusted.
[0132] By-product ammonia may be used in the process, thereby realizing treating wastes with wastes and a circular economy. Comparison between (a) the apparatus and methods; and (b) the calcium-based desulfurization/sodium-based desulfurization method+amine-based decarbonization+carbon sequestration device (also referred to as the “other approaches”): [0133] The apparatus and methods, relative to the other approaches, may occupy a smaller land area and may flexibly adjust the amount of sequestered CO.sub.2; [0134] The apparatus and methods may more flexibly adjust the output of byproducts [0135] In the apparatus and methods, unlike in the other approaches, CO.sub.2 may be used for production of urea, sodium bicarbonate, soda ash, food-grade CO.sub.2, polycarbonate, methanol, synthesis gas, and polyurethane, and used for enhanced oil recovery, welding, gas fertilizer, and the like. The total demand in China is close to 150 million ton/year; [0136] Decarbonization with amines after calcium-based desulfurization may require the provision of an alkaline deep desulfurization device, and the decarbonization capital cost may be increased by 60-80% over that of the existing desulfurization device. The capital cost for ammonia-based desulfurization may be about 85-95% of the calcium-based desulfurization, and the capital cost for ammonia-based decarbonization may be about 60% of amine-based decarbonization. Integrated desulfurization and decarbonization may further reduce the capital cost by about 10-20%. Therefore, the capital cost of the integrated desulfurization and decarbonization technology may be 40-50% lower than that for the calcium-based desulfurization+sodium-based desulfurization+amine-based decarbonization. Moreover, it does not generate any wastewater or waste residues.
[0137] The operating cost of the integrated desulfurization and decarbonization technology may be 50-60% lower than those of the calcium-based desulfurization+alkaline desulfurization+amine-based decarbonization.
[0138] Comparison between (a) ammonia-based desulfurization and decarbonization technology and (b) the calcium-based desulfurization+alkaline desulfurization+amine-based decarbonization technology
TABLE-US-00001 Calcium-based desulfurization + alkaline washing + amine-based Integrated ammonia-based Technology decarbonization desulfurization and decarbonization Raw materials for Limestone powder CaCO3/liquid Anhydrous ammonia or aqueous desulfurization and caustic soda + ethanolamine ammonia decarbonization Byproducts of Gypsum (solid waste)/waste alkali Ammonium sulfate + ammonium desulfurization and bicarbonate (sold as fertilizers) decarbonization Wastewater Yes, about 0.35 t/104 kw No Waste residues Yes No Waste gas Production of CO.sub.2 from desulfurization No at 0.7 t/tSO.sub.2 Capital cost 1A 0.5-0.6A Operating cost 1B-2B 0.4-0.5B Land area Large Small Supporting High, requiring the marine or deep Low, and the product structure can be requirements geological structure layer for carbon flexibly adjusted sequestration
[0139] Technical metrics of the apparatus and methods may include: [0140] Decarbonization efficiency not lower than 50%, and the content of CO.sub.2 (including fine particulates) in the flue gas at the outlet of the decarbonization tower controlled at ≤6% by volume [0141] SO.sub.2 content at the outlet ≤5 mg/Nm.sup.3 [0142] Ammonia recovery (fraction or percentage of ammonia added to a gas cleaning process that is subsequently captured and extracted from the process) ≥98%, and ammonia slip at the decarbonization outlet ≤10 ppm [0143] Power consumption ≤250 kW.Math.h/t CO.sub.2 [0144] Steam consumption ≤1.2 t/t CO.sub.2
[0145] Apparatus and methods for ammonia-based desulfurization and decarbonization are provided. The ammonia may be used to remove sulfur oxides and CO.sub.2 in process gas. The process gas may be fed into a desulfurization apparatus.
[0146] The methods may include (1) removing, using desulfurization circulating fluid, SO.sub.2 from the process gas. The methods may include (2) removing, using a decarbonization circulating fluid, CO.sub.2 from the process gas. The methods may include (3) removing, using desulfurization circulating fluid, free ammonia from the process gas. The methods may include returning the desulfurization circulating fluid to a desulfurization apparatus. The methods may include performing two or more of the aforementioned steps in the order presented.
[0147] The methods may include producing fertilizer. The fertilizer may include ammonium sulfate. The fertilizer may include ammonium bicarbonate.
[0148] The removing of CO.sub.2 may be performed such that a CO.sub.2 removal efficiency from 30-98% is achieved.
[0149] The methods may include producing from the decarbonization circulating fluid ammonium bicarbonate fertilizer. The methods may include regenerating gaseous CO.sub.2 from the decarbonization circulating fluid. The regenerating may be performed in a regeneration system that includes a CO.sub.2 regeneration tower having a tower bottom and a tower top.
[0150] An operating temperature at the tower bottom may be in a range from 90-150° C. The range may be from 100-130° C.
[0151] An operating temperature at the tower top may be in a range from 6-100° C. The range may be from 70-90° C.
[0152] A regeneration pressure at the tower bottom may be in a range from 0.2-0.7 MPa. The range may be from 0.3-0.5 MPa.
[0153] The methods may include flowing gas in the tower at a gas velocity in a range from 0.2-3 m/s. The range may be from 0.3-2 m/s.
[0154] The methods may include producing from the decarbonization circulating fluid ammonium bicarbonate fertilizer. The methods may include producing, from gaseous CO.sub.2 removed from the process gas, a downstream product.
[0155] The downstream product may include urea. The downstream product may include soda ash. The downstream product may include sodium bicarbonate. The downstream product may include polycarbonate. The downstream product may include CO.sub.2 gas fertilizer. The downstream product may include potassium bicarbonate. The downstream product may include food-grade CO.sub.2.
[0156] The methods may include enhanced oil recovery, with gaseous CO.sub.2 removed from the process gas.
[0157] The methods may include sequestering gaseous CO.sub.2 removed from the process gas. The sequestering may include performing marine sequestration. The sequestering may include performing underground sequestration.
[0158] The methods may include, between step 2 and step 3, removing, using process water, free ammonia from the process gas. The methods may include, after step 3, removing, using process water, free ammonia from the process gas.
[0159] The desulfurization circulating fluid may include a concentrated circulating fluid. The desulfurization circulating fluid may include an absorbing circulating fluid. The concentrated circulating fluid may have ammonium sulfite at a concentration of 0-0.2%. The concentrated circulating fluid may have ammonium sulfate at a concentration of 10-60%. The absorbing circulating fluid may have ammonium sulfite at a concentration of 0.1-3%. The absorbing circulating fluid may have ammonium sulfate at a concentration of 10-38%.
[0160] The concentrated circulating fluid may have a pH of 1-6. The concentrated circulating fluid may have a pH of 2-4.5.
[0161] The absorbing circulating fluid may have a pH of 4.5-6.5. The absorbing circulating fluid may have a pH of 4.8-6.2.
[0162] The decarbonization circulating fluid may have a pH of 7-13. The decarbonization circulating fluid may have a pH of 7.5-11. The decarbonization circulating fluid may have a pH of 8-9.5.
[0163] The decarbonization circulating fluid may have ammonium bicarbonate at a concentration of 340%. The decarbonization circulating fluid may have ammonium bicarbonate at a concentration of 10-22%.
[0164] The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 0.6-4. The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 1.2-3. The decarbonization circulating fluid may have an NH.sub.3/CO.sub.2 molar ratio of 2-2.5.
[0165] The desulfurization may include absorbing SO.sub.2 at a temperature in a range from 5-55° C. The desulfurization may include absorbing SO.sub.2 at a temperature in a range from 15-50° C. The desulfurization may include absorbing SO.sub.2 at a temperature in a range from 20-40° C.
[0166] The decarbonization may include absorbing CO.sub.2 at a temperature in a range from 0-45° C. The decarbonization may include absorbing CO.sub.2 at a temperature in a range from 5-40° C. The decarbonization may include absorbing CO.sub.2 at a temperature in a range from 10-30° C.
[0167] The apparatus may be configured to perform one or more steps of the methods.
[0168] The apparatus may include an ammonia-based desulfurization functional area that may be configured to apply a desulfurizing agent to a process gas. The desulfurization functional area may include a desulfurization tower. The apparatus may include an ammonia-based decarbonization functional area that may be configured to apply a decarbonizing agent to the process gas. The decarbonization functional area may include a decarbonization tower. The apparatus may include an ammonia washing functional area. The ammonia washing functional area may include an ammonia washing tower. The apparatus may include an ammonium sulfate post-processing system. The apparatus may include an ammonium bicarbonate post-processing system.
[0169] The desulfurizing agent may include ammonium. The decarbonizing agent may include ammonium. The desulfurization functional area may be configured to receive the process gas. The desulfurization functional area may be configured to desulfurize the process gas. The decarbonization functional area may be configured to receive the process gas after the process gas exits the desulfurization functional area. The decarbonization functional area may be configured to remove carbon dioxide from the process gas. The decarbonization functional area may be configured to produce an ammonium bicarbonate-containing material. The material may include a solution. The material may include a slurry. The ammonia washing functional area may be configured to receive process gas after the process gas exits the decarbonization functional area. The ammonia washing functional area may be configured to wash the process gas with a desulfurization circulating fluid. The ammonia washing functional area may be configured to wash the process gas with process water. The ammonia washing functional area may be configured to wash the process gas with process water after the ammonia washing functional area washes the process gas with a desulfurization circulating fluid. The ammonia washing functional area may be configured to wash the process gas with a desulfurization circulating fluid after the ammonia washing functional area washes the process gas with process water.
[0170] The desulfurization functional area may be configured to receive the process gas after the process gas exits the ammonia washing functional area. The desulfurization functional area may be configured to receive the process water after the process water exits the ammonia washing functional area. The desulfurization functional area may be configured to spray the process gas and the process water as an absorbing agent for desulfurization. The desulfurization functional area may be configured to receive ammonium sulfate-containing ammonium bicarbonate solution after the ammonium bicarbonate solution exits the decarbonization functional area.
[0171] The ammonia washing functional area may be configured to wash the process gas with the process water before washing the process gas with the desulfurization circulating fluid.
[0172] The ammonia-based desulfurization functional area, the ammonia-based decarbonization functional area, and the ammonia washing functional area may be disposed in a tower.
[0173] The desulfurization functional area may include a cooling and concentrating segment that may include a first spraying layer. The desulfurization functional area may include an absorbing segment. The absorbing segment may include a second spraying layer. The absorbing segment may be in fluid communication with the cooling and concentrating segment via a first device. The first device may be configured to allow gas to pass. The desulfurization functional area may include a particulate removing segment. The particulate removing segment may be in fluid communication with the absorbing segment via a second device. The second device may be configured to allow gas to pass. Each of the segments may include at least one spraying layer. Each of the segments may include a device that may be configured to allow gas to pass between the segments.
[0174] The apparatus may include, in the particulate removing segment, a first washing part configured to wash with concentrated, circulating ammonium sulfate-containing solution. The apparatus may include, in the particulate removing segment, a second washing part. The second washing part may be configured to wash with dilute, circulating ammonium sulfate-containing solution. The second washing part may be in fluid communication with the first washing part via a device that allows gas to pass.
[0175] The first part may be configured to maintain an ammonium sulfate concentration of the concentrated ammonium sulfate-containing solution in a range that is 10-38%. The first part may be configured to maintain an ammonium sulfate concentration of the concentrated ammonium sulfate-containing solution in a range that 12-30%. The first part may be configured to maintain a pH of the concentrated ammonium sulfate-containing solution in a range that is 2.5-7.5. The first part may be configured to maintain a pH of the concentrated ammonium sulfate-containing solution in a range that is 3-5.5.
[0176] The second part may be configured to maintain an ammonium sulfate concentration of the dilute ammonium sulfate-containing solution in a range that is 0-5%. The second part may be configured to maintain an ammonium sulfate concentration of the dilute ammonium sulfate-containing solution in a range that is 0.02-2%. The second part may be configured to maintain a pH of the dilute ammonium sulfate-containing solution in a range that is 3-7.
[0177] The desulfurization functional area may include a cooling apparatus. The cooling apparatus may be configured to maintain a temperature of process gas in a range that is 5-55° C. The range may be 15-50° C. The range may be 20-40° C.
[0178] The decarbonization functional area may include a cooling apparatus. The cooling apparatus may be configured to maintain a temperature of process gas in a range that is 0-45° C. The range may be 5-40° C. The range may be 10-30° C.
[0179] The apparatus may include a circulating pipeline. The circulating pipeline may be configured to transport desulfurization circulating fluid. The cooling apparatus may be arranged on the circulating pipeline. The cooling apparatus may be configured to cool spraying fluid. The cooling apparatus may be configured to cool circulating desulfurization fluid. The cooling apparatus may be configured to cool the process gas. The cooling apparatus may be configured to circulate water as a coolant.
[0180] The apparatus may include a process gas conduit. The cooling apparatus may be arranged on the process gas conduit. The cooling apparatus may be configured to cool the process gas.
[0181] The ammonia washing functional area may be configured to receive desulfurization fluid from the ammonia-based desulfurization functional area. The ammonia washing functional area may be configured to, using the desulfurization fluid, absorb ammonia from post-decarbonization process gas. The ammonia washing functional area may be configured to, after absorbing the ammonia, return the desulfurization fluid to the desulfurization functional area. The ammonia washing functional area may be configured to collect aqueous solution during ammonia washing. The ammonia washing functional area may be configured to provide the aqueous solution to the desulfurization functional area. The desulfurization functional area may be configured to use the returned desulfurization fluid to desulfurize the process gas. The desulfurization functional area may be configured to use the provided aqueous solution for particle removal. A pH of ammonium sulfate washing solution may be controlled at 2.5-7.5. The pH may be a pH of the solution in a washing part of the particulate removing segment. The washing part may be a first washing part. For example, the pH may be a pH of the solution in a desulfurization circulating tank of the desulfurization functional area, a washing circulating pump of the particulate removing segment of the desulfurization functional area, or any other suitable location.
[0182] An ammonia concentration in an ammonia washing circulating solution in the ammonia washing functional area may be controlled at 0-5%. An ammonia concentration in an ammonia washing circulating solution in the ammonia washing functional area may be controlled at 0-1%.
[0183] The apparatus may include a purification membrane separation apparatus. The apparatus may include a conduit. The particulate removing segment may be configured to provide dilute ammonium sulfate solution. The purification membrane separation apparatus may be configured to receive the dilute ammonium sulfate solution. The purification membrane separation apparatus may be configured to produce purified water from the dilute ammonium sulfate solution. The conduit may be configured to convey a fraction of the purified water to the ammonia washing functional area.
[0184] The ammonia washing functional area may be configured to use the purified water to replenish circulating washing water in the ammonia washing functional area.
[0185] The ammonia washing functional area may be configured to use the purified water to control a concentration of ammonia in the washing water.
[0186] The ammonia washing functional area may be configured to use the purified water to control a concentration of ammonium sulfate solution for return to the desulfurization functional area.
[0187] The conduit may include a first conduit. The fraction may include a first fraction. The apparatus may include a second conduit. The second conduit may be configured to convey concentrated solution to a desulfurization absorption area of the desulfurization functional area.
[0188] The apparatus may include an ammonium bicarbonate post-processing system. The decarbonization functional area may be configured to produce an ammonium bicarbonate slurry. The ammonium bicarbonate post-processing system may be configured to remove solution from the slurry. The ammonium bicarbonate post-processing system may be configured to pack the slurry into a product. The ammonium bicarbonate post-processing system may be configured to return the solution to the decarbonization functional area.
[0189] The apparatus may include a CO.sub.2 regeneration system. The CO.sub.2 regeneration system may be configured to heat ammonium bicarbonate from the decarbonization functional area to produce CO.sub.2. The CO.sub.2 regeneration system may be configured to heat ammonium bicarbonate from the decarbonization functional area to produce an ammonia solution. The CO.sub.2 regeneration system may be configured to provide the ammonia solution to the decarbonization functional area.
[0190] The ammonia-based desulfurization functional area may be configured to control a gas velocity at 0.5-5 m/s. The ammonia-based desulfurization functional area may be configured to control a gas velocity at 2-4 m/s. The ammonia-based desulfurization functional area may be configured to control a circulating fluid spraying density for a spray layer at 4-100 m.sup.3/m.sup.2-h. The ammonia-based desulfurization functional area may be configured to control a circulating fluid spraying density for a spray layer at 8-80 m.sup.3/m.sup.2-h. The ammonia-based desulfurization functional area may be configured to control a circulating fluid temperature at 5-55° C. The ammonia-based desulfurization functional area may be configured to control a circulating fluid temperature at 20-40° C. The ammonia-based desulfurization functional area may be configured to control a circulating fluid pH at 1-7. The gas velocity may be an empty tower gas velocity.
[0191] The ammonia-based decarbonization functional area may be configured to control a gas velocity at 2-4 m/s. The ammonia-based decarbonization functional area may be configured to control a gas temperature at 5-40° C. The ammonia-based decarbonization functional area may be configured to control a gas temperature at 10-30° C. The ammonia-based decarbonization functional area may be configured to control circulating fluid pH at 7-11. The gas velocity may be an empty tower gas velocity.
[0192] The ammonia washing functional area may be configured to control a velocity at 0.25-5 m/s. The ammonia washing functional area may be configured to control a gas temperature at 0-50° C. The ammonia washing functional area may be configured to control a temperature at 3-40° C. The ammonia washing functional area may be configured to control a circulating fluid pH at 3-10.
[0193] The apparatus may include a heat pump system. The heat pump system may be configured to receive water, at a temperature from 3-25° C., from a chilled water cooler that may be in thermal communication with the CO.sub.2. The heat pump system may be configured to receive water, at a temperature from 5-10° C., from a chilled water cooler that may be in thermal communication with the CO.sub.2. The heat pump system may be configured to return the chilled water to the chilled water cooler.
[0194] The apparatus may include a CO.sub.2 regeneration tower. The CO.sub.2 regeneration tower may be configured to extract CO.sub.2 from the process gas.
[0195] The CO.sub.2 regeneration tower may be configured to maintain a temperature of the process gas at a bottom of the tower at 90-150° C. The CO.sub.2 regeneration tower may be configured to maintain a temperature of the process gas at a bottom of the tower at 100-130° C.
[0196] The CO.sub.2 regeneration tower may be configured to maintain a temperature of the process gas at atop of the tower at 6-100° C. The CO.sub.2 regeneration tower may be configured to maintain a temperature of the process gas at a top of the tower at 70-90° C.
[0197] The CO.sub.2 regeneration tower may be configured to maintain a pressure of the process gas at a bottom of the tower at 0.2-0.7 MPa. The CO.sub.2 regeneration tower may be configured to maintain a pressure of the process gas at a bottom of the tower at 0.3-0.5 MPa.
[0198] The CO.sub.2 regeneration tower may be configured to maintain a gas velocity in the tower at 0.2-3 m/s. The CO.sub.2 regeneration tower may be configured to maintain a gas velocity in the tower at 0.3-2 m/s.
[0199] The apparatus may include a process water inlet. The inlet may be disposed on an upper part of the CO.sub.2 regeneration tower.
[0200] The apparatus may include a solution heat exchanger. The apparatus may include a reboiler. The apparatus may include a circulating water cooler. The apparatus may include a chilled water cooler in fluid communication with the circulating water cooler. The apparatus may include a CO.sub.2 buffer tank. The apparatus may include a CO.sub.2 compressor.
[0201] The decarbonization circulating pump may provide a fraction of the bicarbonate-containing material, via the solution heat exchanger, to the CO.sub.2 regeneration tower. The chilled water cooler may be configured to receive CO.sub.2, via the circulating water cooler, from the top of the tower. The CO.sub.2 compressor may be configured to receive CO.sub.2, via the CO.sub.2 buffer tank, from the chilled water cooler. The CO.sub.2 compressor may be configured to compress the CO.sub.2. The CO.sub.2 compressor may be configured to discharge the CO.sub.2.
[0202] The absorbing fluid and/or process gas may be cooled during desulfurization to prepare it for decarbonization. After the decarbonization, a desulfurization circulating fluid may be used for absorption of ammonia from the ammonia-containing process gas. After the absorption, the circulating fluid may be returned to a desulfurization functional area for desulfurization, thereby reducing the amount of ammonia added for desulfurization. After the decarbonization, fresh water may be used to wash the gas. Resultant ammonia-containing washing water may be returned, after the washing, to the desulfurization functional area to replenish washing water that is used to remove desulfurized particulates. Condensate produced from the particulate removing segment may be purified through membrane separation. Clean water may be used as makeup water for ammonia washing. Excess water may be discharged from the apparatus for external use.
[0203] Illustrative embodiments of apparatus and methods in accordance with the principles of the invention will now be described with reference to the accompanying drawings, which forma part hereof. It is to be understood that other embodiments may be utilized and that structural, functional and procedural modifications, additions or omissions may be made, and features of illustrative embodiments, whether apparatus or method, may be combined, without departing from the scope and spirit of the present invention.
[0204] All ranges and parameters disclosed herein shall be understood to encompass any and all subranges subsumed therein, every number between the endpoints, and the endpoints.
[0205] For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more (e.g. 1 to 6.1), and ending with a maximum value of 10 or less (e.g., 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.
[0206] Unless stated otherwise, %-concentrations are volume percentages for gas and weight percentages for liquid.
[0207]
[0208] The ammonia-based desulfurization system may provide liquid that is sent to the tail gas washing system. The tail gas washing system may provide liquid that is sent to the ammonia-based desulfurization system.
[0209] The ammonia-based desulfurization system may provide ammonium sulfate.
[0210] The ammonia-based decarbonization system may exchange material with a CO.sub.2 regeneration system. The ammonia-based decarbonization system may provide ammonium bicarbonate.
[0211] The CO.sub.2 regeneration system may provide CO.sub.2 to a CO.sub.2 compressor. The CO.sub.2 compressor may provide CO.sub.2 to downstream products or processes. The CO.sub.2 compressor may provide CO.sub.2 to a pipe network.
[0212]
[0213] In the apparatus shown in
[0214] Post-desulfurization tail gas 12 may enter the ammonia-based decarbonization system of decarbonization functional area 102 (shown in
[0215] Post-decarbonization tail gas 23 may enter the tail gas washing system of ammonia washing functional area 103 (shown in
[0216] In the apparatus shown schematically in
[0217] Process water 53 may be added to the upper part of CO.sub.2 regeneration tower 41. The apparatus may include heat pump system 50. The heat pump system may produce chilled water. Chilled water supply 54 may be sent to heat exchangers including desulfurization heat exchanger 4, desulfurization heat exchanger 11 (shown in
Example 1
[0218] A coal-fired boiler flue gas (process gas) containing sulfur oxides and CO.sub.2 was introduced into an integrated desulfurization and decarbonization apparatus.
[0219] Process gas 1, which contained sulfur oxides and CO.sub.2, entered desulfurization tower 2 of desulfurization functional area 101. Desulfurization circulating pump 5 was used for spraying and circulation, by which the process gas was cooled while the ammonium sulfate solution was concentrated. The concentrated ammonium sulfate slurry with solid precipitation was sent via ammonium sulfate discharge pump 6 to ammonium sulfate solid-liquid separator 31. The solid was dried in the ammonium sulfate dryer 32, and packed in the ammonium sulfate packing machine 33 to obtain ammonium sulfate product 34. Circulating pump 3 in desulfurization functional area 101 and desulfurization circulating tank 13 were used for absorption spraying and circulation to absorb sulfur oxides (sulfur dioxide and sulfur trioxide) in the process gas, and the desulfurization heat exchanger 4 was used to control the desulfurization temperature. Desulfurization circulating pump 10 and desulfurization circulating water tank 9 were used for washing spraying and circulation, and desulfurization heat exchanger 11 was used to control the washing temperature and the temperature of the post-desulfurization tail gas 12. Flue gas condensate 14 was processed by membrane separation apparatus 15. Concentrated solution 16 obtained from membrane separation was returned to desulfurization tower 2. Purified water was obtained from the membrane separation. Part 18 of the purified water was used as makeup water for ammonia washing tower 25, and part 17 of the purified water was discharged. Ammonia 8 was metered and provided to desulfurization circulating tank 13 for ammonia addition. Oxidation air 7 was provided to desulfurization circulating tank 13 for oxidizing the solution.
[0220] Post-desulfurization tail gas 12 entered decarbonization tower 19 of decarbonization functional area 102. Decarbonization circulating pump 21 was used for absorption spraying and circulation, and a resulting slurry was sent by decarbonization discharge pump 22 to ammonium bicarbonate solid-liquid separator 37. The resulting solid was dried in ammonium bicarbonate drier 38, and packed in ammonium bicarbonate packing machine 39 to obtain ammonium bicarbonate product 40. Ammonia 24 was metered and provided to decarbonization tower 19 for ammonia addition. Part of the ammonium sulfate-containing ammonium bicarbonate solution was returned to desulfurization functional area 101.
[0221] Post-decarbonization tail gas 23 entered ammonia washing tower 25 of ammonia washing functional area 103. Ammonia washing tower circulating pump 26 was used for first-stage washing. First-stage washing fluid coming from acidic desulfurization fluid 35 of particulate washing circulating pump 20 of desulfurization circulating tank 13 was continuously added to ammonia washing tower 25. Desulfurization fluid 36, having absorbed ammonia, was returned to desulfurization circulating tank 13. Circulating pump 27 for the ammonia washing functional area 103 and circulating water tank 28 for the ammonia washing functional area 103 were used for second-stage washing. Second-stage washing fluid came from purified water 18. After the washing, wash drainage liquid 29 was returned to desulfurization functional area 101. After the washing, clean flue gas 30 was discharged.
[0222] 99.6% anhydrous ammonia was used as an absorbing agent for desulfurization and decarbonization. Process gas (boiler flue gas) parameters are given in the table below:
TABLE-US-00002 No. Item Value 1 Flow rate, Nm.sup.3/h 560000 2 Temperature, ° C. 160 3 SO.sub.2 content, mg/Nm.sup.3 4500 4 CO.sub.2 content, v % 12 5 H.sub.2O content, v % 5.48 6 O.sub.2 content, v % 8.65
[0223] The main parameters of the desulfurization system are given in the table below:
TABLE-US-00003 No. Item Value 1 Gas flow rate at outlet of desulfurization tower, 528326 Nm.sup.3/h 2 Temperature at outlet of desulfurization tower, ° C. 18 3 SO.sub.2 content at outlet of desulfurization tower, ppm <5 4 CO.sub.2 content at outlet of desulfurization tower, v % 12.7 5 H.sub.2O content at outlet of desulfurization tower, v % 2.0 6 Output of byproduct ammonium sulfate, t/h 5.24 7 Desulfurization efficiency, % 99.9 8 Consumption of 99.6% anhydrous ammonia, t/h 1.34
[0224] The main parameters of the decarbonization tower are given in the table below:
TABLE-US-00004 No. Item Value 1 Gas flow rate at outlet of decarbonization tower, 468360 Nm.sup.3/h 2 CO.sub.2 content at outlet of decarbonization tower, v % 1.4 3 NH.sub.3 content at outlet of decarbonization tower, ppm 900 4 Decarbonization efficiency, % 90 5 Output of byproduct ammonium bicarbonate, t/h 221.9 6 Consumption of 99.6% anhydrous ammonia, t/h 46.0
[0225] The main parameters of the tail gas after treatment by the ammonia washing tower are given in the table below:
TABLE-US-00005 No. Item Value 1 Gas flow rate at outlet of ammonia washing tower, 467940 Nm.sup.3/h 2 CO.sub.2 content at outlet of ammonia washing tower, v % 1.4 3 NH.sub.3 content at outlet of ammonia washing tower, ppm <3 4 SO.sub.2 content at outlet of ammonia washing tower, ppm <2
Example 2
[0226] A coal-fired boiler flue gas (process gas) containing sulfur oxides and CO.sub.2 was entered into an integrated desulfurization and decarbonization apparatus.
[0227] Process gas 1 containing sulfur oxides and CO.sub.2 entered desulfurization tower 2 of desulfurization functional area 101. Desulfurization circulating pump 5 was used for spraying and circulation, which cooled the process gas while concentrating the ammonium sulfate solution. The resulting concentrated ammonium sulfate slurry with solid precipitate was sent via ammonium sulfate discharge pump 6 to ammonium sulfate solid-liquid separator 31. The solid was dried in ammonium sulfate drier 32, and packed in ammonium sulfate packing machine 33 to obtain ammonium sulfate product 34. Circulating pump 3 in desulfurization functional area 101 and desulfurization circulating tank 13 were used for absorption spraying and circulation to absorb sulfur oxides (sulfur dioxide and sulfur trioxide) in the process gas, and desulfurization heat exchanger 4 was used to control the desulfurization temperature. Desulfurization circulating pump 10 and desulfurization circulating water tank 9 were used for washing spraying and circulation. Desulfurization heat exchanger 11 was used to control the washing temperature and the temperature of post-desulfurization tail gas 12. Flue gas condensate 14 was processed by membrane separation apparatus 15. Concentrated solution 16 obtained from membrane separation was returned to desulfurization tower 2. Purified water was obtained from the membrane separation. Part 18 of the purified water was used as makeup water for ammonia washing tower 25, and part 17 of the purified water was discharged. Ammonia 8 was metered and then provided to desulfurization circulating tank 13 as ammonia addition. Oxidation air 7 was provided to desulfurization circulating tank 13 for oxidizing the solution.
[0228] Post-desulfurization tail gas 12 entered decarbonization tower 19 of decarbonization functional area 102. Decarbonization circulating pump 21 was used for absorption spraying and circulation, and a resulting slurry was sent by decarbonization discharge pump 22 to ammonium bicarbonate solid-liquid separator 37. The resulting solid was dried in ammonium bicarbonate drier 38, and packed in ammonium bicarbonate packing machine 39 to obtain ammonium bicarbonate product 40. Ammonia 24 was metered and then provided to decarbonization tower 19 as ammonia addition. Part of the ammonium sulfate-containing ammonium bicarbonate solution was returned to desulfurization functional area 101.
[0229] Post-decarbonization tail gas 23 entered ammonia washing tower 25 of ammonia washing functional area 103. Circulating pump 26 for ammonia washing tower 25 was used for first-stage washing. First-stage washing fluid coming from acidic desulfurization fluid 35 of particulate washing circulating pump 20 of desulfurization circulating tank 13 was continuously added to ammonia washing tower 25. Desulfurization fluid 36, having-absorbed ammonia, was returned to desulfurization circulating tank 13. Circulating pump 27 for ammonia washing functional area 103 and circulating water tank 28 for ammonia washing functional area 103 were used for second-stage washing. Second-stage washing fluid came from purified water 18. After the washing, wash drainage liquid 29 was returned to desulfurization functional area 101. After the washing, clean flue gas 30 was discharged.
[0230] The apparatus included CO.sub.2 regeneration tower 41 in which the decarbonization circulating fluid was regenerated. Operating parameters of CO.sub.2 regeneration tower 41 were: 100-130° C. at tower bottom, 60-90° C. at tower top, an operating pressure of 0.3-0.4 MPa at tower bottom, and a gas velocity of 0.6-0.8 m/s.
[0231] The apparatus included solution heat exchanger 42, reboiler 43, circulating water cooler 44, chilled water cooler 45, CO.sub.2 buffer tank 46, and CO.sub.2 compressor 47.
[0232] Solution extracted at the outlet of decarbonization circulating pump 21 was sent to solution heat exchanger 42 before entering CO.sub.2 regeneration tower 41. The solution at the bottom of tower 41 was heated by steam in reboiler 43, and CO.sub.2 gas was collected at the top of tower 41. The gas was cooled in two-stage cooling by circulating water cooler 44 and chilled water cooler 45, before being sent to CO.sub.2 buffer tank 46. CO.sub.2 from buffer tank 46 was compressed by CO.sub.2 compressor 47, and subsequently 10% thereof was sent to CO.sub.2 downstream production apparatus 49 for production of polycarbonate, 5% was loaded into bottles or into tanker 48, and 85% was sent for sequestration.
[0233] Condensate 52 was taken out from the bottom of reboiler 43.
[0234] Process water 53 was added to the upper part of CO.sub.2 regeneration tower 41.
[0235] The apparatus included heat pump system 50. Heat pump system 50 produced chilled water. Chilled water supply 54 was sent to heat exchangers including chilled water cooler 45, desulfurization heat exchanger 4 and desulfurization heat exchanger 11 for the cooling of CO.sub.2 gas and circulating fluids. Chilled water return 55 was returned to heat pump system 50.
[0236] 99.6% anhydrous ammonia was used as an absorbing agent for flue gas desulfurization and decarbonization for a 600 MW unit. Process gas (boiler flue gas) parameters are given in the table below:
TABLE-US-00006 No. Item Value 1 Flue gas flow rate, Nm.sup.3/h 2100000 2 Temperature, ° C. 150 3 SO.sub.2 content, mg/Nm.sup.3 7000 4 CO.sub.2 content, v % 12 5 H.sub.2O content, v % 6.1 6 O.sub.2 content, v % 5.9
[0237] The main parameters of the desulfurization system are given in the table below:
TABLE-US-00007 No. Item Value 1 Gas flow rate at outlet of desulfurization tower, Nm.sup.3/h 1923557 2 Temperature at outlet of desulfurization tower, ° C. 18 3 SO.sub.2 content at outlet of desulfurization tower, ppm <10 4 CO.sub.2 content at outlet of desulfurization tower, v % 13.1 5 H.sub.2O content at outlet of desulfurization tower, v % 2.0 6 Output of byproduct ammonium sulfate, t/h 30.6 7 Desulfurization efficiency, % 99.9 8 Consumption of 99.6% anhydrous ammonia, t/h 7.8
[0238] The main parameters of the decarbonization tower are given in the table below:
TABLE-US-00008 No. Item Value 1 Gas flow rate at outlet of decarbonization tower, 1698128 Nm.sup.3/h 2 CO.sub.2 content at outlet of decarbonization tower, v % 1.48 3 NH.sub.3 content at outlet of decarbonization tower, ppm 800 4 Decarbonization efficiency, % 90 5 Output of byproduct ammonium bicarbonate, t/h 83.3 6 Consumption of 99.6% anhydrous ammonia, t/h 17.3
[0239] The main parameters of the tail gas after treatment by the ammonia washing tower are given in the table below:
TABLE-US-00009 No. Item Value 1 Gas flow rate at outlet of ammonia 1696783 washing tower, Nm.sup.3/h 2 CO.sub.2 content at outlet of ammonia 1.49 washing tower, v % 3 NH.sub.3 content at outlet of ammonia <8 washing tower, ppm 4 SO.sub.2 content at outlet of ammonia <2 washing tower, ppm
[0240] The main parameters of the CO.sub.2 gas after regeneration by the CO.sub.2 regeneration tower and the two-stage cooling are given in the table below:
TABLE-US-00010 No. Item Value 1 Gas flow rate, Nm.sup.3/h 204313 2 CO.sub.2 content, v % 99.9 3 NH.sub.3 content in the gas, ppm <20 4 Water content in the gas, ppm <500 5 Gas pressure, MPa 0.3
Selected Embodiments
[0241] 1. An ammonia desulfurization and decarbonization method using ammonia to remove sulfur oxides and CO.sub.2 in process gas, characterized in that the method sequentially comprises the following steps: [0242] 1) removing part of SO.sub.2 in the process gas with a desulfurization circulating fluid; [0243] 2) removing part of CO.sub.2 in the process gas with a decarbonization circulating fluid; and [0244] 3) removing part of free ammonia in the process gas with the desulfurization circulating fluid, and returning the desulfurization circulating fluid to a desulfurization apparatus.
[0245] 2. The method according to selected embodiment 1, characterized by at least one of the following: [0246] products comprise ammonium sulfate and ammonium bicarbonate fertilizers; and [0247] the CO.sub.2 removal rate in step 2) is 30-98%.
[0248] 3. The method according to selected embodiment 1, characterized in that the steps further comprise: [0249] sending part of the decarbonization circulating fluid to an ammonium bicarbonate post-processing apparatus to produce ammonium bicarbonate fertilizer, [0250] and/or sending part of the decarbonization circulating fluid to a CO.sub.2 regeneration apparatus for regeneration to obtain gaseous CO.sub.2, [0251] wherein regeneration of the decarbonization circulating fluid proceeds in a CO.sub.2 regeneration system that includes a tower top and a tower bottom, the system with the following operating parameters: the regeneration temperature is 90-150° C. and preferably 100-130° C. at tower bottom, and 6-100° C. and preferably 70-90° C. at tower top; the regeneration pressure is 0.2-0.7 MPa and preferably 0.3-0.5 MPa at tower bottom; and the regeneration tower gas velocity is 0.2-3 m/s and preferably 0.3-2 m/s.
[0252] 4. The method according to selected embodiment 1, characterized in that part of the gaseous CO.sub.2 is used for production of downstream products or oil displacement, the downstream products comprising urea, soda ash, sodium bicarbonate, polycarbonate, food CO.sub.2, CO.sub.2 gas fertilizer, potassium bicarbonate, and the like, and/or part of the CO.sub.2 is used for marine sequestration or underground sequestration.
[0253] 5. The method according to selected embodiment 1, characterized in that the method further comprises step 4) between step 2) and step 3) in which process water is used to remove part of free ammonia in the process gas, and/or further comprises step 5) after step 3) in which the process water is used to further remove part of free ammonia in the process gas.
[0254] 6. The method according to selected embodiment 1, characterized in that the desulfurization circulating fluid comprises a concentrated circulating fluid and an absorbing circulating fluid, [0255] the concentrated circulating fluid has [0256] a pH of 1-6 and preferably 2-4.5, [0257] ammonium sulfite at a concentration of 0-0.2%, and [0258] ammonium sulfate at a concentration of 10-60%, and [0259] the absorbing circulating fluid has [0260] a pH of 4.5-6.5 and preferably 4.8-6.2, [0261] ammonium sulfite at a concentration of 0.1-3%, and [0262] ammonium sulfate at a concentration of 10-38%.
[0263] 7. The method according to selected embodiment 1, characterized in that the decarbonization circulating fluid has a pH of 7-13, preferably 7.5-11, and more preferably 8-9.5, ammonium bicarbonate at a concentration of 3-40% and preferably 10-22%, and an NH.sub.3/CO.sub.2 molar ratio of 0.6-4, preferably 1.2-3, and more preferably 2-2.5.
[0264] 8. The method according to selected embodiment 1, characterized in that the desulfurization absorption temperature is 5-55° C., preferably 15-50° C., and more preferably 20-40° C.; and the decarbonization absorption temperature is 0-45° C., preferably 5-40° C., and more preferably 10-30° C.
[0265] 9. An apparatus for implementing the method according to any one of selected embodiments 1-8, characterized in that an ammonia desulfurization functional area, an ammonia decarbonization functional area, an ammonia washing functional area, an ammonium sulfate post-processing system, and an ammonium bicarbonate post-processing system are provided; ammonium is used as a desulfurizing and decarbonizing agent; process gas first enters the desulfurization functional area for desulfurization to produce an ammonium sulfate fertilizer; the desulfurized process gas enters the decarbonization functional area to remove carbon dioxide in the process gas and produce an ammonium bicarbonate-containing solution/slurry; the decarbonized process gas contains free ammonia and enters the ammonia washing functional area for washing with a desulfurization circulating fluid and then with the process water; after the washing, the ammonia-containing desulfurization solution and process water solution are returned to the desulfurization functional area and serve as an absorbing agent for desulfurization; and part of the ammonium sulfate-containing ammonium bicarbonate solution is returned to the desulfurization functional area.
[0266] 10. The apparatus according to selected embodiment 9, characterized in that the ammonia washing functional area further comprises washing with the process water before washing with the desulfurization circulating fluid, and the ammonia desulfurization functional area, the ammonia decarbonization functional area, and the ammonia washing functional area are combined in one tower or multiple towers.
[0267] 11. The apparatus according to selected embodiment 9, characterized in that the desulfurization functional area is divided into a plurality of segments, comprising a cooling and concentrating segment, an absorbing segment, and a particulate removing segment, each segment being provided with at least one spraying layer, and a device/part allowing gas to pass through being arranged between the segments.
[0268] 12. The apparatus according to selected embodiment 11, characterized in that the particulate removing segment is divided into two parts; for spray washing in the first part, an ammonium sulfate-containing concentrated solution is used for circulated washing; an ammonium sulfate-containing dilute solution is used in the second part for circulated washing; and a device/part allowing gas to pass through is arranged between the two parts; the concentration of the concentrated ammonium sulfate solution in the first part is controlled at 10-38%, preferably 12-30%, and the pH is controlled at 2.5-7.5, preferably 3-5.5; and the concentration of the dilute ammonium sulfate solution in the second part is controlled at 0-5%, preferably 0.02-2%, and the pH is controlled at 3-7.
[0269] 13. The apparatus according to selected embodiment 11, characterized in that the desulfurization functional area is provided with a cooling apparatus to control the temperature of desulfurized flue gas at 5-55° C., preferably 15-50° C., and more preferably 20-40° C.
[0270] 14. The apparatus according to selected embodiment 11, characterized in that the decarbonization functional area is provided with a cooling apparatus to control the temperature of decarbonized flue gas at 0-45° C., preferably 5-40° C., and more preferably 10-30° C.
[0271] 15. The apparatus according to selected embodiment 13, characterized by at least one of the following: the cooling apparatus is arranged on the circulating pipeline for the desulfurization circulating fluid to cool the spraying and circulating desulfurization fluid and to further cool the desulfurized flue gas; or the cooling apparatus is arranged on the process gas pipe/flue in the desulfurization functional area to directly cool the gas; and circulating water and/or chilled water is used as a cooling agent.
[0272] 16. The apparatus according to selected embodiment 9, characterized by at least one of the following: [0273] the ammonia washing circulating solution is taken from the ammonia desulfurization functional area to wash ammonia, and then returned to the ammonia desulfurization functional area for desulfurization, and the pH of the ammonium sulfate washing solution is controlled at 2.5-7.5; and [0274] part of the water solution absorbed during the ammonia washing circulation enters replenishing water for the circulating fluid for the particulate removing segment of the desulfurization functional area, and the ammonia concentration in the ammonia washing circulating solution is controlled at 0-5%, preferably 0-1%.
[0275] 17. The apparatus according to selected embodiment 12, characterized in that part of the dilute ammonium sulfate solution is pumped out and sent to a purification membrane separation apparatus, the produced purified water is used as replenishing water for the deamination and washing functional area and the excess part is for external use to control the ammonia concentration in the washing water and the concentration of the dilute ammonium sulfate solution for desulfurization and washing, and the concentrated water enters a desulfurization absorption area.
[0276] 18. The apparatus according to selected embodiment 9, characterized by at least one of the following: [0277] desulfurization, decarbonization, and ammonia washing functional areas, wherein one or a combination of spraying absorption, plate absorption, filler absorption, and float valve absorption is adopted in the decarbonization functional area; [0278] the ammonium sulfate slurry produced from desulfurization is packed into a product after solid-liquid separation and drying, or is output directly as a wet product; [0279] the ammonium bicarbonate slurry produced from decarbonization is partially packed into a product after solid-liquid separation and drying, or is output directly as a wet product; the solution obtained from the separation is returned to the decarbonization apparatus; and [0280] the ammonium bicarbonate slurry or ammonium bicarbonate solution produced from decarbonization is further heated, partially or wholly, to produce CO.sub.2 and an ammonia solution, the ammonia solution is returned to the decarbonization functional area for further use, and CO.sub.2 is used for production of downstream products, oil displacement, beverage production, sequestration, and the like.
[0281] 19. The apparatus according to selected embodiment 9, characterized in that main parameters of the ammonia desulfurization functional area are as follows: [0282] 1) empty tower gas velocity controlled at 0.5-5 m/s, preferably 2-4 m/s; [0283] 2) circulating fluid spraying density of each layer at 4-100 m.sup.3/m.sup.2.Math.h, preferably 8-80 m.sup.3/m.sup.2.Math.h; [0284] 3) circulating fluid temperature controlled at 5-55° C., preferably 20-40° C.; and [0285] 4) circulating fluid pH controlled at 1-7.
[0286] 20. The apparatus according to selected embodiment 9, characterized in that main parameters of the decarbonization functional area are as follows: [0287] 1) empty tower gas velocity controlled at 0.1-5 m/s; [0288] 2) temperature controlled at 5-40° C., preferably 10-30° C.; and [0289] 3) circulating fluid pH controlled at 7-11.
[0290] 21. The apparatus according to selected embodiment 9, characterized in that main parameters of the ammonia washing functional area are as follows: [0291] 1) empty tower gas velocity controlled at 0.25-5 m/s; [0292] 2) temperature controlled at 0-50° C., preferably 3-40° C.; and [0293] 3) circulating fluid pH controlled at 3-10.
[0294] 22. The apparatus according to selected embodiment 9, further comprising a heat pump system, wherein the heat pump system provides the chilled water required for cooling, and the temperature of the chilled water obtained by the heat pump is 3-25° C., preferably 5-10° C.
[0295] 23. The apparatus according to selected embodiment 9, further comprising a CO.sub.2 regeneration tower having a tower top and a tower bottom, wherein regeneration of the decarbonization circulating fluid proceeds in the CO.sub.2 regeneration tower.
[0296] 24. The apparatus according to selected embodiment 23, characterized in that the operating parameters are as follows: the regeneration temperature is 90-150° C. and preferably 100-130° C. at tower bottom, and 6-100° C. and preferably 70-90° C. at tower top; the regeneration pressure is 0.2-0.7 MPa and preferably 0.3-0.5 MPa at tower bottom; and the regeneration tower gas velocity is 0.2-3 m/s and preferably 0.3-2 m/s.
[0297] 25. The apparatus according to selected embodiment 23, characterized in that a process water inlet is provided on an upper part of the regeneration tower.
[0298] 26. The apparatus according to selected embodiment 23, characterized in that the gaseous CO.sub.2 obtained by the regeneration tower is partially used for production of downstream products comprising urea, soda ash, sodium bicarbonate, polycarbonate, food CO.sub.2, CO.sub.2 gas fertilizer, potassium bicarbonate, and the like, partially used for oil displacement, beverage production, and gas welding, and partially used for marine sequestration or underground sequestration.
[0299] 27. The apparatus according to selected embodiment 23, further comprising a solution heat exchanger, a reboiler, a circulating water cooler, a chilled water cooler, a CO.sub.2 buffer tank, and a CO.sub.2 compressor, wherein the decarbonization circulating pump outputs a part of the solution to the solution heat exchanger for heat exchange, the solution then enters the CO.sub.2 regeneration tower, the CO.sub.2 gas collected at the top of the tower is cooled by the coolers, then sent to the CO.sub.2 buffer tank, and is sent out after compression by the CO.sub.2 compressor.
[0300] Thus, apparatus and methods for desulfurization and decarbonization have been provided. Persons skilled in the art will appreciate that the present invention may be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation. The present invention is limited only by the claims that follow.