Integrated ammonia desulfurization and decarbonation apparatus and method

Abstract

This technology applies to the desulfurization and decarbonation of process gases containing sulfur oxides and CO2, contributing to environmental conservation. Ammonia is used as a desulfurization and decarbonation agent. The gas is first desulfurized in a desulfurization unit to produce ammonium sulfate fertilizer. The desulfurized gas then enters a decarbonation unit to remove carbon dioxide from the gas and produce ammonium bicarbonate fertilizer. The decarbonated gas containing free ammonia is scrubbed with a desulfurization circulating solution and then with water. The scrubbed solution is returned to the desulfurization tower and used as an absorbent for further desulfurization. This technology organically integrates decarbonation and desulfurization technologies, achieving high ammonia scrubbing efficiency by scrubbing ammonia with an acidic desulfurization circulating solution and eliminating the ammonia slip problem that often occurs in the decarbonation process. The process is simple, requires low investment and operating costs, and can simultaneously produce ammonium sulfate fertilizer and ammonium bicarbonate fertilizer, eliminating the need for underground injection and sequestration of the entire CO2. Instead, part of the CO2 can be used to produce downstream products such as urea and soda ash. By flexibly adjusting the product mix and using the by-product ammonia, it is possible to treat waste with waste and realize a circular economy.

Description

[Technical field]

[0001] The present disclosure relates to the technical field of environmental protection, and in particular to an apparatus and method for the removal of sulfur oxides and CO2 using ammonia. [Background technology]

[0002] Gaseous species such as CO2 and methane in the atmosphere allow short-wavelength solar radiation to pass through but can block long-wavelength radiation from the Earth's surface to space. When concentrations of greenhouse gases such as carbon dioxide become high, the incoming energy exceeds the outgoing energy, causing the temperature of the Earth's atmosphere to rise. This is called the greenhouse effect.

[0003] Carbon dioxide is the most important greenhouse gas, and the main source of carbon dioxide emissions is the use of fossil fuels. China ranks first in the world in terms of total carbon dioxide emissions. China's coal-centered energy structure will continue for some time, and coal energy will remain the basis for peak shaving and energy security through new energy. China has committed to the world that it will cap its carbon emissions by 2030 and achieve carbon neutrality by 2060. The capture, storage and utilization of CO2 in flue gases play an important role in controlling and reducing greenhouse gas emissions and addressing the greenhouse effect and global warming issues.

[0004] At present, the mainstream carbon capture technology adopted worldwide is the amine process. The amine process has problems such as high operating costs and large amounts of waste that are difficult to treat. Research into new decarbonation technologies is being actively conducted in China and other countries. The ammonia process is easier to regenerate and has lower operating costs than the amine process, and produces ammonium bicarbonate fertilizer as a by-product of decarbonation. In addition, a part of the decarbonation circulation liquid can be regenerated to obtain CO2 that can be used for the production of downstream products such as urea, soda ash, and polycarbonate, as well as for enhanced oil recovery, beverage production, and welding, and can also be directly returned to the ground or ocean. Ammonium bicarbonate is a representative complex multi-nutrient fertilizer that can simultaneously supply nitrogen and CO2 to plants, and is particularly suitable for modern agriculture in which soilless cultivation and greenhouse plant growth are performed, realizing the recycling of CO2 and the reuse of carbon, and avoiding secondary pollution and environmental accidents that may occur due to underground carbon storage. Compared with decarbonation by the amine method, ammonia has a higher CO2 absorption efficiency and is easier to regenerate ammonium bicarbonate, significantly reducing the cost of decarbonation.

[0005] Ammonia-based decarbonation technology has been the focus of research as the best way to solve greenhouse gases. However, ammonia is volatile and decarbonation needs to be carried out under alkaline conditions, which increases ammonia slip. Unless these problems are solved, ammonia slip may cause increased decarbonation costs and secondary pollution.

[0006] China Patent Publication No. 104707451 discloses a method for ammonia-based carbon capture and chemical synthesis from flue gas, which is carried out in a flue gas absorption synthesis unit. The flue gas absorption synthesis unit includes a flue gas path, an absorption tower and a carbonization tower connected in parallel, an ammonia removal tower, and a solid-liquid separation unit. Ammonia water is used as an absorbent to capture CO2 in the flue gas, and sodium sulfate is used as a conversion medium to produce chemical products such as sodium carbonate and sodium bicarbonate. For the ammonia-containing tail gas after decarbonation, a simple water washing method is used to remove ammonia, which results in high ammonia slip.

[0007] Chinese Patent Application No. 201110039363.2 discloses a system and process for capturing and absorbing sulfur dioxide and carbon dioxide under normal pressure using an ammonia-based process, in which desulfurization is performed, followed by decarbonation, and the desulfurization and decarbonation units are equipped with multiple heat exchangers to control the absorption temperature. At the same time, concentrated ammonia water is first used for desulfurization and decarbonation, and then dilute ammonia water is used for desulfurization and decarbonation. After decarbonation, the gas is discharged as it is. Absorption using ammonia water cannot sufficiently reduce ammonia slip at low temperatures and low concentrations. In addition, the concentration of ammonia water cannot be made too low, and low concentration ammonia water will bring in a large amount of water, which will inhibit the crystallization of the desulfurization product ammonium sulfate and the decarbonation product ammonium bicarbonate.

[0008] China Patent Publication No. 104874272 discloses an integrated desulfurization and carbon dioxide recovery device and method, in which the SO2 in the flue gas is first removed by an ammonia-based desulfurization device, and then the flue gas is cooled by a direct contact cooling device before entering the decarbonation tower. After decarbonation, the gas enters the ammonia scrubbing tower where it is washed with water. After washing, the flue gas enters a direct contact heating device, and some ammonia is removed in the spray contact heating process. The aqueous solution discharged from the direct contact cooling tower is used as the spray contact liquid, and the solution after direct contact spraying is cooled in a cooling tower and used for direct contact cooling spraying. The aqueous ammonia solution in the water scrubbing tower enters the decarbonation tower to be decarbonated or enters the stripping tower to remove ammonia. In the regenerative contact tower, sulfuric acid, an acidic reagent, is added to promote ammonia washing. This method has the following problems: If the water after direct water washing is returned to decarbonation, a large amount of water is added to the decarbonation system, which increases capital and operating costs. In addition, sulfuric acid is consumed to wash ammonia with sulfuric acid. The need for separate contact cooling and contact reheating equipment complicates the process, resulting in high capital and operating costs. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] China Patent Application Publication No. 104707451 [Patent Document 2] Chinese Patent Application No. 201110039363.2 [Patent Document 3] China Patent Application Publication No. 104874272 Summary of the Invention

[0010] In view of the above problems, the present inventors have developed an integrated technology for ammonia-based desulfurization and decarbonation based on the experience of ammonia-based desulfurization. In the desulfurization process, the temperature of the absorption liquid and / or process gas is cooled to meet the temperature requirements of the subsequent decarbonation, the ammonia-containing process gas after decarbonation is first absorbed in the desulfurization circulation liquid, and the absorbed circulation liquid is returned to the desulfurization function area for desulfurization, thereby reducing the amount of ammonia added for desulfurization, the exhaust gas after decarbonation is further washed with clean water, and after washing, the ammonia-containing washing water is also returned to the desulfurization function area as a replenishment of washing water for desulfurization fine particle washing, the condensed water generated in the desulfurization fine particle washing is purified by membrane separation, the obtained purified water is used as make-up water for ammonia washing, and the surplus is discharged from the device for external use. Effect of the Invention

[0011] The present disclosure may have the following advantages. 1. Good cleaning efficiency achieved by using acidic desulfurization absorption liquid to clean ammonia-containing process gas. 2. The desulfurization circulating liquid is used to remove ammonia in the process gas after decarbonation, and the desulfurization circulating liquid obtained as a result of ammonia washing is directly used in decarbonation, thereby simplifying the process and realizing the integration of desulfurization and decarbonation. 3. After ammonia washing, the ammonia-containing washing water is directly used as makeup water for desulfurization fine particle washing, thereby reducing the amount of desulfurization makeup water. 4. The process is simplified since there is no need for separate contact cooling equipment. 5. Eliminate wastewater discharge by reusing condensed water after purification by membrane separation. 6. The possibility of recovering some or all of the recovered ammonium sulfate and ammonium bicarbonate fertilizers and decarbonation circulating liquid to obtain CO2 that can be used in beverage production, enhanced oil recovery, welding, and the manufacture of downstream products including urea, soda ash, sodium bicarbonate, polycarbonate, polyurethane, food grade CO2, CO2 gas fertilizer, potassium bicarbonate, etc., without the need to inject and sequester all the CO2 underground, truly realizing carbon emission reductions. 7. There is no need to control the SO2 concentration at the outlet of the desulfurization functional area to below 2 ppm, and the capital and operating costs of the desulfurization equipment are reduced by removing sulfur oxides that cannot be completely removed in the desulfurization functional area using the decarbonation equipment. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an exemplary block flow diagram in accordance with an embodiment of the process of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an integrated ammonia-based desulfurization and decarbonation apparatus according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing the CO2 regeneration section of an integrated ammonia-based desulfurization and decarbonation apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An integrated ammonia-based desulfurization and decarbonation apparatus and method are provided. The apparatus and method use ammonia to remove sulfur oxides and CO2 to produce ammonium sulfate fertilizer and ammonium bicarbonate fertilizer. The apparatus includes an ammonia-based desulfurization functional area, an ammonia-based decarbonation functional area, an ammonia washing functional area, an ammonium sulfate post-treatment system, and an ammonium bicarbonate post-treatment system. Ammonia is used as a desulfurization agent and a decarbonation agent. The gas first enters the desulfurization functional area to be desulfurized and produce ammonium sulfate fertilizer. The desulfurized gas enters the decarbonation functional area where carbon dioxide is removed and produce ammonium bicarbonate fertilizer. The decarbonated gas containing free ammonia enters the ammonia washing functional area to be washed with ammonium sulfate solution for desulfurization and then washed with water. After the ammonia washing, the ammonia-containing ammonium sulfate liquid and aqueous solution can be returned to the desulfurization tower and serve as an absorbent for desulfurization. The above functional areas may be combined into one tower or multiple towers. The desulfurization functional area may be divided into multiple sections, including a cooling concentration section, an absorption section, and a particulate removal section. Each zone may be provided with at least one sprayed layer, and between the zones may be located devices / components through which gas can pass.

[0014] In some preferred embodiments, the fine particle removal zone is divided into two parts, the first fine particle removal part of which performs circulatory spray cleaning using a concentrated solution containing ammonium sulfate, and the second fine particle removal part of which performs circulatory cleaning using a dilute solution containing ammonium sulfate. A device / component for passing gas may be disposed between the two parts. The concentration of the concentrated ammonium sulfate solution used in the first fine particle removal part may be controlled to 5-40%, preferably 10-30%, and the pH may be controlled to 3-7, preferably 3-5.5. The concentration of the dilute ammonium sulfate solution used in the second fine particle removal part may be controlled to 0.02-10%, preferably 0.03-5%, and the pH may be controlled to 3-7.

[0015] In some preferred embodiments, an apparatus according to the present disclosure comprises a desulfurization circulation vessel including an oxidation chamber and an ammonia addition chamber in fluid communication with each other, the oxidation chamber configured to allow contact and reaction of at least a portion of the reflux liquid from the absorption section with an oxygen-containing gas and to remove at least a portion of its liquid phase for circulation to the first particulate removal section and the ammonia scrubbing functional area, and the ammonia addition chamber in fluid communication with the oxidation chamber and configured to allow mixing of at least a portion of the reflux liquid from the absorption section with an ammonia absorbent and to remove therefrom a liquid phase for circulation to the absorption section.

[0016] The integrated desulfurization and decarbonation process includes: 1) removing a portion of the SO2 in the process gas using a desulfurization circulating liquid; 2) removing a portion of the CO2 in the process gas using a decarbonation circulating liquid; and 3) A process in which a portion of the free ammonia in the process gas is removed using the desulfurization circulating liquid, and the desulfurization circulating liquid after absorbing the free ammonia is returned to the desulfurization equipment. Includes sequentially.

[0017] In some preferred embodiments, step 3) utilizes the desulfurization circulating liquid from the oxidation chamber of the desulfurization circulating tank to remove a portion of the free ammonia in the process gas, and returns the desulfurization circulating liquid after absorbing the free ammonia to the desulfurization apparatus.

[0018] In some embodiments, steps 1) and 2) provide a product comprising ammonium sulfate fertilizer and ammonium bicarbonate fertilizer.

[0019] In some embodiments, the CO2 removal efficiency in step 2) may be in the range of 30-98%.

[0020] In some embodiments, at least a portion of the decarbonated recycle may be sent to an ammonium bicarbonate post-treatment unit to produce ammonium bicarbonate fertilizer, or at least a portion of the decarbonated recycle may be sent to a CO2 regeneration unit to obtain gaseous CO2. The CO2 so produced may be used in one or more of beverage production, enhanced oil recovery, and welding, or may be used to produce one or more downstream products including urea, soda ash, sodium bicarbonate, polycarbonate, polyurethane, food grade CO2, CO2 gas fertilizer, potassium bicarbonate, etc.

[0021] In some embodiments, the method according to the present disclosure further comprises between steps 2) and 3) 4) removing a portion of the free ammonia present in the process gas using process water, and / or after step 3) 5) further removing a portion of the free ammonia present in the process gas using process water.

[0022] The desulfurization circulation liquid as used herein includes concentrated circulation liquid and absorption circulation liquid. In some embodiments, the concentrated circulation liquid has a pH of 1 to 6, preferably 2 to 4.5, an ammonium sulfite concentration of 0 to 0.2%, and an ammonium sulfate concentration of 10 to 60%, and the absorption circulation liquid has a pH of 4.5 to 6.5, preferably 4.8 to 6.2, an ammonium sulfite concentration of 0.1 to 3%, and an ammonium sulfate concentration of 10 to 38%.

[0023] In some embodiments, the decarbonation circulating fluid used herein has a pH of 7 to 13, preferably 7.5 to 11, more preferably 8 to 9.5, an ammonium bicarbonate concentration of 3 to 40%, preferably 10 to 22%, and an NH3 / CO2 molar ratio of 0.6 to 4, preferably 1.2 to 3, more preferably 2 to 2.5.

[0024] In some embodiments, the desulfurization absorption temperature is in the range of 5 to 55°C, preferably 15 to 50°C, and more preferably 20 to 40°C, and the decarbonation absorption temperature is in the range of 0 to 45°C, preferably 5 to 40°C, and more preferably 10 to 30°C. A refrigeration technique using a heat pump may be used for cooling the decarbonation circulating liquid and the desulfurization circulating liquid. The temperature of the cold water obtained by the heat pump may be in the range of 3 to 25°C, and preferably 5 to 10°C.

[0025] The power source of the heat pump may include one or more of hot water, steam, and electricity. The cold source may be circulating water or desalinated water. If desalinated water is used, the desalinated water after heat exchange may be sent to a low-temperature coal economizer to reduce the coal consumption per ton of steam.

[0026] In some embodiments, the desulfurization functional area is equipped with a cooling device for controlling the temperature of the desulfurized flue gas in the range of 5 to 55 ° C, preferably 20 to 40 ° C. This range may meet the temperature requirements for the subsequent decarbonation. The cooling device may be arranged on the circulation path of the desulfurization circulation liquid and may cool the desulfurization circulation liquid. After cooling, the cooled desulfurization circulation liquid may further cool the desulfurized flue gas. The cooling device may be provided in multiple locations, for example on the circulation and absorption paths in the absorption section and the fine particle removal section, preferably on the wash water path in the second fine particle removal section. The wash condensate may be purified by membrane separation. The concentrated liquid enters the desulfurization absorption area, and the clean water may be used as makeup water for ammonia washing or may be used externally.

[0027] In some embodiments, the cooling equipment may be located in the process gas path, at the inlet, inside or outlet of the desulfurization functional area. As a coolant, circulating water or cold water may be used individually or in combination.

[0028] In some embodiments, the desulfurization circulating liquid for ammonia washing may be taken from the circulating washing liquid of the desulfurization tower, and after ammonia washing, returned to the ammonia-based desulfurization functional area for desulfurization. The pH of the desulfurization circulating liquid for ammonia washing may be controlled to 2.5 to 7.5, preferably 3 to 5.5. In some embodiments, the desulfurization circulating liquid for ammonia washing may be taken from the oxidation chamber of the desulfurization circulating tank.

[0029] In some embodiments, the pH of the washing process water used in the ammonia washing functional area may be controlled to 3 to 7. At least a part of the aqueous solution obtained by the ammonia washing with the process water may enter the circulation liquid for the second fine particle removal section of the desulfurization tower as makeup water. Therefore, the ammonium sulfate concentration in the circulation liquid can be controlled to 0 to 5%, preferably 0.02 to 2%.

[0030] In some embodiments, a part of the water washing circulation liquid in the second particulate removal section may be pumped and sent to the purification membrane separation device. The purified water produced may be used as make-up water for the ammonia washing function area to control the ammonia concentration in the wash water and thus the concentration of the dilute ammonium sulfate liquid for the desulfurization section. The concentrate coming from the membrane separation device may enter the desulfurization absorption section.

[0031] In some embodiments, the decarbonation and ammonia wash functional areas may utilize one or a combination of spray absorption, plate absorption, packed column absorption, and floating valve absorption columns.

[0032] In some embodiments, the ammonium sulfate slurry produced from the desulfurization may enter an ammonium sulfate post-treatment system. After solid-liquid separation, the wet ammonium sulfate may be dried and packaged into an ammonium sulfate product. Alternatively, wet ammonium sulfate may be produced directly. The liquor from the solid-liquid separator may be returned to the desulfurization functional area. If ammonium sulfate liquor is produced, it should be evaporated and crystallized to form an ammonium sulfate slurry before entering the solid-liquid separation equipment.

[0033] In some embodiments, the ammonium bicarbonate slurry produced from the decarbonation tower may enter a solid-liquid separation device. The resulting liquid may be returned to the decarbonation functional area. The wet ammonium bicarbonate may be dried and packaged as a product. Alternatively, the wet ammonium bicarbonate product may be produced directly. In some embodiments, at least a portion of the ammonium bicarbonate produced from the decarbonation may be heated to produce CO2 and an ammonia solution, which may be returned to the decarbonation functional area for further use.

[0034] In some embodiments, the main parameters of the desulfurization functional area are as follows: Superficial gas velocity controlled to 0.5 to 5 m / sec, preferably 2 to 4 m / sec 4~100m 3 / m 2 Time, preferably 8-80m 3 / m 2 -Time, circulating fluid spray density of each layer The temperature of the circulating fluid is controlled to 5 to 55°C, preferably 20 to 40°C. · Circulating fluid pH controlled between 1 and 7 may include:

[0035] In some embodiments, the main parameters of the decarboxylation functional region are as follows: Superficial gas velocity controlled between 0.1 and 5 m / sec Temperature controlled between 5 and 40°C, preferably between 10 and 30°C - pH of circulating fluid controlled between 7 and 11 may include:

[0036] In some embodiments, the main parameters of the ammonia wash functional area are as follows: Superficial gas velocity controlled between 0.25 and 5 m / sec Temperature controlled to 0-50°C, preferably 3-40°C · Circulating fluid pH controlled between 3 and 10 may include:

[0037] In some embodiments, strong acids such as sulfuric acid, nitric acid, or hydrochloric acid may be added in the desulfurization and / or ammonia wash functional areas to adjust the pH of the circulating liquid.

[0038] In some embodiments, the apparatus further includes a heat pump system to provide cooling capacity for cooling the decarbonation circulation liquid and the desulfurization circulation liquid using heat pump refrigeration technology. The temperature of the cold water provided by the heat pump may range from 3 to 25°C, preferably 5 to 10°C. The cold water supply path / return path are connected with the respective cold heat exchangers.

[0039] In some embodiments, the apparatus further comprises a CO2 regeneration tower in which regeneration of the decarbonated circulating liquid proceeds. The operating parameters of the CO2 regeneration tower are: At the bottom of the column, the regeneration temperature is in the range of 90 to 150°C, preferably 100 to 130°C. At the top of the column, the regeneration temperature is in the range of 6 to 100°C, preferably 70 to 90°C. At the bottom of the column, a regeneration pressure in the range of 0.2 to 0.7 MPa, preferably 0.3 to 0.5 MPa Regeneration tower gas velocity in the range of 0.2 to 3 m / s, preferably 0.3 to 2 m / s may include:

[0040] In some embodiments, the apparatus further comprises one or more of a solution heat exchanger, a reboiler, a circulating water chiller, a cold water chiller, a CO2 buffer tank, and a CO2 compressor.

[0041] In some embodiments, the ammonium bicarbonate solution / slurry coming from the decarbonation functional area can be sent to a CO2 regeneration unit to produce CO2 and ammonia solution.

[0042] In some embodiments, after gas-liquid separation, the gaseous CO2 obtained from the regeneration may be used to produce downstream products such as urea, soda ash, sodium bicarbonate, polycarbonate, food grade CO2, CO2 gas fertilizer, potassium bicarbonate, etc., or may be used in enhanced oil recovery, beverage production, or welding, or may be used for marine or underground sequestration. The separated liquid may be returned to the CO2 regeneration tower.

[0043] The embodiment of the present invention integrates the decarbonation process with the desulfurization process. The embodiment of the present invention addresses the problem of ammonia slip in the decarbonation process by using an acidic desulfurization circulation liquid to wash the ammonia so as to achieve high ammonia washing efficiency. The process is simpler, has lower investment and operating costs, can co-produce ammonium sulfate fertilizer and ammonium bicarbonate fertilizer, and can also inject part of the CO2 underground for sequestration. This will flexibly adjust the amount of ammonium bicarbonate produced, the amount of sequestered CO2, and the amount of CO2 downstream products produced.

[0044] According to the embodiment of the present invention, the by-product ammonia will be used in the process, which will realize a circular economy by treating waste with waste.Comparing (a) the embodiment of the present invention with (b) calcium-based desulfurization / sodium-based desulfurization method + amine-based decarbonation + carbon sequestration device, The device of the present invention will have a small footprint and flexibly adjust the amount of sequestered CO2; ·The present invention has a simple process and can adjust the by-product production more flexibly, and the CO2 can be used to produce urea, sodium bicarbonate, soda ash, food-grade CO2, polycarbonate, methanol, syngas, and polyurethane, enhanced oil recovery, welding, gas fertilizer, etc. The total demand in China is close to 150 million tons / year; ·When decarbonating with amine after calcium-based desulfurization, an alkaline deep desulfurization device needs to be prepared, and the desulfurization capital cost may increase by 60-80% compared with the existing desulfurization device. In addition, the capital cost of the conventional ammonia-based desulfurization is about 85-95% of that of calcium-based desulfurization, and the capital cost of ammonia-based decarbonation may be about 60% of that of amine-based decarbonation. The integrated desulfurization and decarbonation may further reduce the capital cost by about 10-20%. Therefore, the capital cost of the integrated ammonia-based desulfurization and decarbonation technology may be 40-50% lower than that of calcium-based desulfurization + sodium-based desulfurization + amine-based decarbonation. Furthermore, the present invention does not generate wastewater or waste residues.

[0045] The operating costs of the integrated ammonia-based desulfurization and decarbonation technology can be 50-60% lower than those of calcium-based desulfurization + alkali-based desulfurization + amine-based decarbonation.

[0046] Comparison between (a) integrated ammonia-based desulfurization and decarbonation technology and (b) calcium-based desulfurization + alkali-based desulfurization + amine-based decarbonation technology

[0047] [Table 1]

[0048] Technical features of the present apparatus and method may include: The decarbonation efficiency is 50% or more, and the CO2 (including fine particles) content in the exhaust gas at the outlet of the decarbonation tower is controlled to 6% or less. Outlet SO2 content is 5mg / Nm 3 Is less than or equal to Ammonia recovery (the proportion or percentage of ammonia added to the gas scrubbing process and then recovered and extracted from the process) is greater than 98% and ammonia slip at the process outlet is less than or equal to 10 ppm ·Electricity consumption is 250kW·hour / ton CO2 or less Steam consumption is 1.2 tons / ton CO2 or less

[0049] Unless otherwise specified, concentrations (%) used herein are % by volume for gases and % by weight for liquids.

[0050] BRIEF DESCRIPTION OF THE DRAWINGS Next, an ammonia-based desulfurization and decarbonation apparatus and method according to some embodiments of the present invention will be described with reference to the accompanying drawings.

[0051] FIG. 1 is an exemplary block flow diagram in accordance with an embodiment of the process of the present invention.

[0052] 2 and 3 are diagrams illustrating an integrated ammonia-based desulfurization and decarbonation apparatus according to some embodiments of the present invention. Referring to FIG. 2, a process gas 1 containing sulfur oxides and CO2 may enter the desulfurization functional area 2. The desulfurization circulation pump a5 may be used for spraying and circulation. This may cool the process gas and concentrate the ammonium sulfate aqueous solution into a slurry. The ammonium sulfate slurry, which may contain solid precipitates, may be sent to the ammonium sulfate solid-liquid separator 31 via the ammonium sulfate discharge pump 6. The solids may be dried in the ammonium sulfate dryer 32 and packaged in the ammonium sulfate packaging machine 33 to obtain the ammonium sulfate product 34. The circulation pump b3 and the desulfurization circulation tank 13 in the desulfurization functional area 2 may be used for absorption spraying and circulation to absorb sulfur oxides (sulfur dioxide and sulfur trioxide) in the process gas. The desulfurization heat exchanger a4 may be used to control the desulfurization temperature. The desulfurization circulation pump c10 and the desulfurization circulation water tank 9 may be used for washing spraying and circulation. The desulfurization heat exchanger b11 may be used to control the washing temperature and the temperature of the desulfurized tail gas 12. The exhaust gas condensate 14 may be treated in a membrane separation device 15. The concentrated liquid obtained from the membrane separation 16 may be returned to the desulfurization functional area 2 for use. A portion 18 of the purified water may be used as makeup water for the ammonia washing tower. A portion 17 of the purified water may be discharged to the outside. Ammonia 8 may be measured and then sent to the ammonia addition chamber of the desulfurization circulation tank 13 as ammonia addition. Oxidation air 7 may be sent to the oxidation chamber of the desulfurization circulation tank 13 to oxidize the desulfurization circulation liquid.

[0053] The tail gas 12 after desulfurization may enter the decarbonation functional area 19. A decarbonation circulation pump 21 may be used for absorption spraying and circulation, and the solution / slurry may be sent to the ammonium bicarbonate solid-liquid separator 37 by the decarbonation discharge pump 22. The solids may be dried in the ammonium bicarbonate dryer 38 and packaged in the ammonium bicarbonate packaging machine 39 to obtain the ammonium bicarbonate product 40. The ammonia 24 is metered and then sent to the decarbonation tower 19 as ammonia addition.

[0054] The tail gas 23 after decarbonation may enter the ammonia washing function area 25. The circulation pump a 26 for the ammonia washing tower may be used for the first stage of washing. The washing liquid of the first stage may come from the acidic desulfurization liquid 35 of the fine particle washing circulation pump of the desulfurization circulation tank 13 and be continuously added to the bottom of the ammonia washing tower 25. Preferably, the acidic desulfurization liquid 35 is from the fine particle washing circulation pump connected to the oxidation chamber of the desulfurization circulation tank 13. The desulfurization liquid 36 that has absorbed ammonia may be returned to the desulfurization circulation tank 13, preferably to the oxidation chamber. The circulation pump b 27 for the ammonia washing function area and the circulating water tank 28 for the ammonia washing function area may be used for the second stage of washing. The washing liquid of the second stage may come from the purified water 18. After washing, the liquid may be returned to the desulfurization function area 2. After washing, the clean flue gas 30 may be discharged.

[0055] Referring to FIG. 3, the decarbonation circulation pump 22 may output a portion of the solution to a heat exchanger 42 for heat exchange. The solution may then enter a CO2 regeneration tower 41. After the bottom of the tower is heated by steam in a reboiler 43, CO2 gas may be recovered at the top of the tower. This gas is two-stage cooled by a circulating water cooler 44 and a cold water cooler 45. The gas may then be sent to a CO2 buffer tank 46, where it may be buffered for a certain period of time and then compressed by a CO2 compressor 47. A portion of the CO2 may then be sent to a downstream production device 49 to produce downstream products including urea, soda ash, etc. Another portion may be loaded into a bottle or tanker 48. Condensate may be taken from the bottom of the reboiler 43.

[0056] Process water 53 may be added to the top of the CO2 regeneration tower 41.

[0057] The apparatus may further include a heat pump system 50. The heat pump system may generate chilled water. The chilled water supply 54 may be sent to heat exchangers including the chilled water cooler 45, the desulfurization heat exchanger a5, and the desulfurization heat exchanger b3 to cool one or more of the process gas (exhaust gas), the CO2 gas, and the circulating liquid. The chilled water return 55 may be returned to the heat pump system 50.

[0058] The present disclosure provides the following embodiments. Embodiment 1. 1. An integrated desulfurization and decarbonation process for removing sulfur oxides and CO2 in a process gas using ammonia, the process comprising: 1) Removal of part of the SO2 from the process gas using a desulfurization circulating liquid; 2) Removing a portion of the CO2 from the process gas using a decarbonated circulating liquid; 3) removing a portion of the free ammonia from the process gas using a desulfurization circulating tank, preferably a desulfurization circulating liquid coming from an oxidation chamber of the desulfurization circulating tank, and returning the desulfurization circulating liquid having absorbed the free ammonia to the desulfurization device; This includes performing the steps in sequence.

[0059] Embodiment 2. Features include: the products of the process include ammonium sulfate fertilizer and ammonium bicarbonate fertilizer; The CO2 removal rate in step 2) is in the range of 30 to 98%. The method comprises: producing ammonium bicarbonate fertilizer from a portion of the decarbonated circulating liquor in an ammonium bicarbonate post-treatment unit; and / or a part of the decarbonation circulating liquid is supplied to a CO2 regeneration system for regeneration, thereby obtaining gaseous CO2, wherein the regeneration is carried out in the CO2 regeneration system, and in this case, the operating parameters preferably further include an operating temperature at the bottom of the tower in the range of 90 to 150°C, preferably 100 to 130°C, an operating temperature at the top of the tower in the range of 6 to 100°C, preferably 70 to 90°C, a regeneration pressure at the bottom of the tower in the range of 0.2 to 0.7 MPa, preferably 0.3 to 0.5 MPa, and a gas velocity in the tower in the range of 0.2 to 3 m / sec, preferably 0.3 to 2 m / sec; the process further comprises producing downstream products from the gaseous CO2, preferably including urea, soda ash, sodium bicarbonate, polycarbonate, food grade CO2, CO2 gas fertilizer, potassium bicarbonate, using the gaseous CO2 for enhanced oil recovery, and / or sequestrating the gaseous CO2 at sea or underground, 2. The method of embodiment 1, comprising at least one of:

[0060] Embodiment 3. Between steps 2) and 3), 4) removing free ammonia from the process gas using process water, and / or 2. The method of embodiment 1, further comprising, after step 3), 5) removing free ammonia from the process gas using process water.

[0061] Embodiment 4. Features include: The desulfurization circulating liquid includes a concentrated circulating liquid and an absorption circulating liquid, The concentrated circulating liquid has a pH of 1 to 6, preferably 2 to 4.5, an ammonium sulfite concentration of 0 to 0.2% and an ammonium sulfate concentration of 10 to 60%, and The absorption circulation liquid has a pH of 4.5 to 6.5, preferably 4.5 to 6.2, an ammonium sulfite concentration of 0.1 to 3%, and an ammonium sulfate concentration of 10 to 38%, the decarbonation circulating liquid has a pH of 7 to 13, preferably 7.5 to 11, more preferably 8 to 9.5, an ammonium bicarbonate concentration of 3 to 40%, preferably 10 to 22%, and an NH3 / CO2 molar ratio of 0.6 to 4, preferably 1.2 to 3, more preferably 2 to 2.5; The desulfurization absorption temperature is in the range of 5 to 55°C, preferably 15 to 50°C, and more preferably 20 to 40°C; The temperature of the decarbonation absorption is in the range of 0 to 45°C, preferably 5 to 40°C, and more preferably 10 to 30°C; 2. The method of embodiment 1, comprising at least one of:

[0062] Embodiment 5. An apparatus for carrying out any one of the methods of embodiments 1 to 4, the apparatus comprising an ammonia-based desulfurization functional area, an ammonia-based decarbonation functional area, an ammonia washing functional area, an ammonium sulfate post-treatment system, and an ammonium bicarbonate post-treatment system, ammonia is used as a desulfurization agent and a decarbonation agent, the process gas first enters the desulfurization functional area to be desulfurized and produce ammonium sulfate fertilizer, the desulfurized process gas enters the decarbonation functional area to remove carbon dioxide and produce an ammonium bicarbonate solution / slurry, the decarbonated process gas containing free ammonia enters the ammonia washing functional area to be washed with the desulfurization circulating liquid, and then with the process water, after washing, the ammonia-containing desulfurization circulating liquid and the process aqueous solution are returned to the desulfurization functional area to become the desulfurization absorbent, and a part of the ammonium sulfate-containing ammonium bicarbonate solution is returned to the desulfurization functional area.

[0063] Embodiment 6. Features include: the apparatus comprises a desulfurization circulation vessel comprising an oxidation chamber and an ammonia addition chamber in fluid communication with each other, the oxidation chamber configured to allow contact and reaction of at least a portion of the reflux liquid from the absorption section with an oxygen-containing gas and to remove at least a portion of the liquid phase thereof for circulation to the particulate removal zone and the ammonia scrubbing functional area, the ammonia addition chamber in fluid communication with the oxidation chamber and configured to allow mixing of at least a portion of the reflux liquid from the absorption zone with an ammonia absorbent and to remove a liquid stream therefrom for circulation to the absorption zone, the ammonia scrubbing functional area is further configured to scrub the process gas with process water prior to scrubbing the process gas with the desulfurization circulation liquid, and the ammonia-based desulfurization functional area, the ammonia-based decarbonation functional area, and the ammonia scrubbing functional area are disposed in one or more columns; 6. The device of embodiment 5, comprising at least one of:

[0064] Embodiment 7. The desulfurization functional area is divided into a plurality of zones including a cooling concentration zone, an absorption zone, and a particulate removal zone, each zone being provided with at least one spray bed, and a device / component allowing gas passage is provided between any two adjacent zones; Preferably, the particulate removal zone comprises: a first particulate removal portion configured to be washed with a concentrated circulating ammonium sulfate-containing solution; and a second particulate removal section configured to be washed with a dilute, circulating ammonium sulfate-containing solution; a device / component is provided between the first particulate removal portion and the second particulate removal portion to allow gas to pass therethrough; the first particulate removal section utilizes a concentrated ammonium sulfate-containing solution having an ammonium sulfate concentration in the range of 10-38%, preferably 12-30%, and a pH in the range of 2.5-7.5, preferably 3-5.5; and The second particulate removal section utilizes a dilute ammonium sulfate-containing solution having an ammonium sulfate concentration in the range of 0 to 5%, preferably 0.02 to 2%, and a pH in the range of 3 to 7; Preferably, the desulfurization functional area includes a cooling device configured to maintain the temperature of the process gas after desulfurization in the range of 5 to 55 ° C, preferably 15 to 50 ° C, more preferably 20 to 40 ° C; Preferably, the cooling device is arranged on a circulation path configured to transport the desulfurization circulation liquid, and cools the desulfurization circulation liquid and thus the process gas after desulfurization, or alternatively, cools the process gas directly on the process gas / exhaust gas conduit of the desulfurization functional area; The apparatus of embodiment 5, wherein the circulating water and / or chilled water is used as a refrigerant in the cooling equipment.

[0065] Embodiment 8. The apparatus of embodiment 5, wherein the decarbonation functional area comprises a cooling device configured to maintain the temperature of the process gas after decarbonation in the range of 0 to 45°C, preferably 5 to 40°C, more preferably 10 to 30°C.

[0066] EMBODIMENT 9. Features include: The desulfurization circulating liquid used for ammonia washing is derived from the ammonium sulfate-containing washing liquid used in the particulate removal section of the ammonia-based desulfurization functional area, and the pH of the ammonium sulfate-containing washing liquid is controlled to 2.5-7.5. The desulfurization circulating liquid after being used for ammonia washing is returned to the ammonia-based desulfurization functional area for desulfurization. The desulfurization circulating liquid used for ammonia washing is from the ammonium sulfate-containing washing liquid used in the absorption section of the ammonia-based desulfurization functional area, and the pH of the ammonium sulfate-containing washing liquid is controlled to 3 to 7, and the desulfurization circulating liquid after being used for ammonia washing is returned to the absorption section of the desulfurization functional area for desulfurization; The ammonia concentration of the ammonia washing circulating liquid is controlled to 0-5%, preferably 0-1%, and a part of the aqueous solution obtained after the ammonia washing is introduced into the circulating liquid of the particulate removal zone of the desulfurization function area as makeup water; 6. The device of embodiment 5, comprising at least one of:

[0067] EMBODIMENT 10. The apparatus of embodiment 7, in which a part of the dilute ammonium sulfate washing solution is pumped out and sent to a purification membrane separation device, the purified water produced is used as make-up water for the ammonia washing function area to control the ammonia concentration in the washing water and the concentration of the dilute ammonium sulfate solution for desulfurization washing, the surplus is discharged from the device for external use, and the concentrated liquid enters the desulfurization absorption area.

[0068] Embodiment 11. Features include: Each of the desulfurization functional area, the decarbonation functional area, and the ammonia washing functional area uses one or a combination of a spray type absorber, a plate type absorber, a packed column type absorber, and a floating valve type absorber; The ammonium sulfate slurry produced by desulfurization is subjected to solid-liquid separation, dried, and packaged into ammonium sulfate products, or the wet ammonium sulfate products are directly produced; Separating the ammonium bicarbonate slurry produced by decarbonation into solid and liquid, returning the separated solution to the decarbonation device, and drying the separated wet ammonium bicarbonate, and packaging it into products or directly producing it as wet ammonium bicarbonate products; Heating some or all of the ammonium bicarbonate solution / slurry produced during decarbonation to produce CO2 and ammonia solution, and returning the ammonia solution to the decarbonation functional area for further use; Use of the CO2 for downstream production, enhanced oil recovery, beverage production or underground sequestration; Ammonia-based desulfurization functional area has the following process parameters: 1) A superficial gas flow velocity of 0.5 to 5 m / sec, preferably 2 to 4 m / sec; 2) 4 to 100 m 3 / m 2 Time, preferably 8-80m 3 / m 2 - time, circulating liquid spray density of each spray layer, 3) a circulating fluid temperature of 5 to 55°C, preferably 20 to 40°C, and 4) Circulating fluid pH of 1 to 7; 2. being configured to operate under The decarbonation functional area is determined by the following process parameters: 1) Superficial gas velocity of 0.1 to 5 m / s; 2) a temperature of 5 to 40°C, preferably 10 to 30°C, and 3) Circulating fluid pH of 7 to 11; 2. being configured to operate under Ammonia cleaning functional area has the following process parameters: 1) Superficial gas velocity of 0.25 to 5 m / sec. 2) a temperature of 0 to 50°C, preferably 3 to 40°C, and 3) Circulating fluid pH of 3 to 10; 2. being configured to operate under the device further comprises a heat pump system configured to supply the cold water required for cooling, the temperature of the cold water from the heat pump system being in the range of 3-25°C, preferably 5-10°C; The device operates according to the following process parameters: a regeneration temperature at the bottom of the column of 90 to 150° C., preferably 100 to 130° C.; a regeneration temperature at the top of the column of 6 to 100° C., preferably 70 to 90° C.; A regeneration pressure at the bottom of the column of 0.2 to 0.7 MPa, preferably 0.3 to 0.5 MPa, and A gas velocity in the regeneration tower of 0.2 to 3 m / s, preferably 0.3 to 2 m / s; Further comprising a CO2 regeneration tower configured to regenerate the decarbonated circulating liquid under and Preferably, the apparatus further comprises a process water inlet disposed at an upper portion of the regeneration tower; Preferably, the gaseous CO2 obtained from the regeneration tower is used for the production of downstream products including urea, soda ash, sodium bicarbonate, polycarbonate, food grade CO2, CO2 gas fertilizer, potassium bicarbonate, enhanced oil recovery, beverage production, or welding, or marine or underground sequestration; Preferably, the apparatus further comprises a solution heat exchanger, a reboiler, a circulating water cooler, a cold water cooler, a CO2 buffer tank, and a CO2 compressor, and the decarbonation circulation pump sends a part of the solution at its outlet to the CO2 regeneration tower via the solution heat exchanger, and takes out gaseous CO2 from the top of the tower, cools it in a cooler, sends it to the CO2 buffer tank, compresses it in the CO2 compressor, and sends it to the outside, in the apparatus of embodiment 5. EXAMPLES

[0069] The present invention will now be described in detail with reference to examples, but these are not intended to limit the scope of the present invention.

[0070] Example 1 Coal-fired boiler flue gas (process gas) containing sulfur oxides and CO2 was fed into an integrated desulfurization and decarbonation apparatus, the process flow of which is shown in Figure 2. The apparatus included a desulfurization functional area 2, a decarbonation functional area 19, and an ammonia washing functional area 25.

[0071] The process gas 1 containing sulfur oxides and CO2 entered the desulfurization functional area 2. Spraying and circulation were performed using the desulfurization circulation pump a5, and the process gas was cooled while concentrating the ammonium sulfate aqueous solution. The concentrated ammonium sulfate slurry containing solid precipitates was sent to the ammonium sulfate solid-liquid separator 31 via the ammonium sulfate discharge pump 6. The solid was dried in the ammonium sulfate dryer 32 and packaged in the ammonium sulfate packaging machine 33 to obtain the ammonium sulfate product 34. Absorption spraying and circulation were performed using the circulation pump b3 and the desulfurization circulation tank 13 (ammonia addition chamber) in the desulfurization functional area 2, and the sulfur oxides (sulfur dioxide and sulfur trioxide) in the process gas were absorbed, and the desulfurization temperature was controlled using the desulfurization heat exchanger a4. Washing spraying and circulation were performed using the desulfurization circulation pump c10 and the desulfurization circulation water tank 9, and the washing temperature and the temperature of the desulfurized tail gas 12 were controlled using the desulfurization heat exchanger b11. The exhaust gas condensate 14 was treated in the membrane separation equipment 15. The concentrated liquid obtained from the membrane separation 16 was returned to the desulfurization functional area 2. A portion of the purified water 18 was used as makeup water for the ammonia washing tower, and the remaining purified water 17 was discharged. Ammonia 8 was weighed and supplied to the ammonia addition chamber of the desulfurization circulation tank 13, and ammonia addition was performed. Oxidation air 7 was supplied to the oxidation chamber of the desulfurization circulation tank 13 to oxidize the solution.

[0072] The tail gas 12 after desulfurization entered the decarbonation functional area 19. Absorption spraying and circulation were performed using the decarbonation circulation pump 21, and the slurry was sent to the ammonium bicarbonate solid-liquid separator 37 by the decarbonation discharge pump 22. The solid was dried in the ammonium bicarbonate dryer 38 and packaged in the ammonium bicarbonate packaging machine 39 to obtain the ammonium bicarbonate product 40. Ammonia 24 was metered and supplied to the decarbonation tower 19 for ammonia addition. A part of the ammonium sulfate-containing ammonium bicarbonate solution was returned to the desulfurization functional area.

[0073] The tail gas 23 after decarbonation entered the ammonia scrubbing functional area 25. The first stage of scrubbing was carried out using the ammonia scrubbing tower circulation pump A 26. The first stage of scrubbing liquid coming from the acidic desulfurization liquid 35 of the fine particle scrubbing circulation pump connected to the oxidation chamber of the desulfurization circulation tank 13 was continuously added to the ammonia scrubbing tower 25. The desulfurization liquid 36 absorbing ammonia was returned to the desulfurization circulation tank 13. The second stage of scrubbing was carried out using the ammonia scrubbing functional area circulation pump B 27 and the ammonia scrubbing functional area circulating water tank 28. The second stage of scrubbing liquid came from the purified water 18. After scrubbing, the liquid was returned to the desulfurization functional area 2. After scrubbing, clean flue gas 30 was discharged.

[0074] 99.6% liquid ammonia was used as an absorbent for desulfurization and decarbonation. The process gas (boiler exhaust gas) parameters are shown in the table below.

[0075] [Table 2]

[0076] The main parameters of the desulfurization system are shown in the table below.

[0077] [Table 3]

[0078] The main parameters of the decarbonation tower are shown in the table below.

[0079] [Table 4]

[0080] The main parameters of the tail gas after treatment in the ammonia scrubber are shown in the table below.

[0081] [Table 5]

[0082] Example 2 Coal-fired boiler flue gas (process gas) containing sulfur oxides and CO2 was fed into an integrated desulfurization and decarbonation device. Figures 2 and 3 show the process flow diagrams. The device shown in Figure 2 included a desulfurization functional area 2, a decarbonation functional area 19, and an ammonia washing functional area 25.

[0083] The process gas 1 containing sulfur oxides and CO2 entered the desulfurization functional area 2. Spraying and circulation were performed using the desulfurization circulation pump a5, and the process gas was cooled while concentrating the ammonium sulfate aqueous solution. The concentrated ammonium sulfate slurry containing solid precipitates was sent to the ammonium sulfate solid-liquid separator 31 via the ammonium sulfate discharge pump 6. The solid was dried in the ammonium sulfate dryer 32 and packaged in the ammonium sulfate packaging machine 33 to obtain the ammonium sulfate product 34. Absorption spraying and circulation were performed using the circulation pump b3 and the desulfurization circulation tank 13 in the desulfurization functional area 2, and the sulfur oxides (sulfur dioxide and sulfur trioxide) in the process gas were absorbed, and the desulfurization temperature was controlled using the desulfurization heat exchanger a4. Washing spraying and circulation were performed using the desulfurization circulation pump c10 and the desulfurization circulation water tank 9, and the washing temperature and the temperature of the desulfurized tail gas 12 were controlled using the desulfurization heat exchanger b11. The exhaust gas condensate 14 was treated in the membrane separation equipment 15. The concentrated liquid obtained from the membrane separation 16 was returned to the desulfurization functional area 2. A portion of the purified water 18 was used as makeup water for the ammonia washing tower, and the remaining purified water 17 was discharged. Ammonia 8 was measured and supplied to the ammonia addition chamber of the desulfurization circulation tank 13, and ammonia addition was performed. Oxidation air 7 was supplied to the oxidation chamber of the desulfurization circulation tank 13 to oxidize the solution.

[0084] The tail gas 12 after desulfurization entered the decarbonation functional area 19. It was absorbed, sprayed, and circulated using the decarbonation circulation pump 21, and the slurry was sent to the ammonium bicarbonate solid-liquid separator 37 by the decarbonation discharge pump 22. The solid was dried in the ammonium bicarbonate dryer 38 and packaged in the ammonium bicarbonate packaging machine 39 to obtain the ammonium bicarbonate product 40. After the ammonia 24 was measured, it was supplied to the decarbonation tower 19 as an ammonia addition. A part of the ammonium sulfate-containing ammonium bicarbonate solution was returned to the desulfurization functional area.

[0085] The tail gas 23 after decarbonation entered the ammonia scrubbing functional area 25. The first stage of scrubbing was carried out using the circulation pump A 26 for the ammonia scrubbing tower. The first stage of scrubbing liquid coming from the acidic desulfurization liquid 35 of the ammonia-based desulfurization functional area was continuously added to the ammonia scrubbing tower 25. The desulfurization liquid 36 having absorbed ammonia was returned to the desulfurization circulation tank 13. The second stage of scrubbing was carried out using the circulation pump B 27 for the ammonia scrubbing functional area and the circulating water tank 28 for the ammonia scrubbing functional area. The second stage of scrubbing liquid came from the purified water 18, after scrubbing the liquid was returned to the desulfurization functional area 2. After scrubbing, clean flue gas 30 was discharged.

[0086] The apparatus further included a CO2 regeneration tower 41 in which the decarbonated circulating liquid was regenerated. The operating parameters of the CO2 regeneration tower 41 were: tower bottom temperature 100-130°C, tower top temperature 60-90°C, tower bottom operating pressure 0.3-0.4 MPa, and gas flow rate 0.6-0.8 m / sec.

[0087] The apparatus further included a solution heat exchanger 42, a reboiler 43, a circulating water cooler 44, a cold water cooler 45, a CO2 buffer tank 46 and a CO2 compressor 47.

[0088] A part of the solution extracted at the outlet of the decarbonation circulation pump 22 was sent to the ammonium bicarbonate post-treatment equipment (37-39) to obtain the ammonium bicarbonate product 40, and the remaining solution was sent to the solution heat exchanger 42 before entering the CO2 regeneration tower 41. A part of the solution at the bottom of the tower was heated by steam in the reboiler 43, and CO2 gas was recovered at the top of the tower. The gas was cooled by two-stage cooling with the circulating water cooler 44 and the cold water cooler 45 before being sent to the CO2 buffer tank 46. After being buffered for a certain period of time, the CO2 from the buffer tank was compressed in the CO2 compressor 47, and then 10% was sent to the CO2 downstream production equipment 49 for polycarbonate production, 5% was loaded into bottles or tankers 48, and 85% was sent to sequestration.

[0089] Condensate was removed from the bottom of reboiler 43.

[0090] Process water 53 was added to the top of the CO2 regeneration tower 41.

[0091] The apparatus further included a heat pump system 50. The heat pump system produced chilled water. The chilled water supply 54 was sent to heat exchangers including the chilled water cooler 45, the desulfurization heat exchanger a, and the desulfurization heat exchanger b for cooling the CO2 gas and the circulating liquid. The chilled water return 55 was returned to the heat pump system 50.

[0092] 99.6% liquid ammonia was used as the absorbent for desulfurization and decarbonation of the 600 MW unit. The process gas (boiler exhaust gas) parameters are shown in the table below.

[0093] [Table 6]

[0094] The main parameters of the desulfurization system are shown in the table below.

[0095] [Table 7]

[0096] The main parameters of the decarbonation tower are shown in the table below.

[0097] [Table 8]

[0098] The main parameters of the tail gas after treatment in the ammonia scrubber are shown in the table below.

[0099] [Table 9]

[0100] The main parameters of the CO2 gas after regeneration by the CO2 regeneration tower and two-stage cooling are shown in the table below.

[0101] [Table 10] [Explanation of symbols]

[0102] In Figures 2 and 3, the reference numerals have the following meanings: 1 Process gas 2 Desulfurization functional area 3 Desulfurization Circulation Pump 1# 4 Desulfurization heat exchanger a 5. Desulfurization Circulation Pump a 6 Ammonium sulfate discharge pump 7. Oxidizing Air 8. Head to the desulfurization system for adding ammonia 9 Desulfurization circulation tank 10 Desulfurization Circulation Pump b 11 Desulfurization heat exchanger b 12 Tail gas after desulfurization 13 Desulfurization circulation tank 14 Exhaust gas condensate 15 Membrane separation equipment 16 Concentrate from membrane separation 17 Purified water discharged from membrane separation 18 Purified water heading to the ammonia cleaning function area 19 Decarboxylation functional area 20. Particle cleaning circulation pump 21 Circulation pump for decarbonation tower 22 Discharge pump for decarbonation tower 23 Tail gas after decarbonation 24 Head to the decarbonation system for adding ammonia 25 Ammonia cleaning functional area 26 Circulation pump for ammonia cleaning function area a 27 Circulation pump for ammonia cleaning function area b 28 Ammonia cleaning tank 29 Ammonia cleaning water drainage 30 Clean exhaust gas 31 Ammonium sulfate solid-liquid separator 32 Ammonium sulfate dryer 33 Ammonium sulfate packaging machine 34 Ammonium sulfate products 35 Acidic desulfurization liquid 36 Returned desulfurization liquid 37 Ammonium bicarbonate solid-liquid separator 38 Ammonium bicarbonate dryer 39 Ammonium bicarbonate packaging machine 40 Ammonium Bicarbonate Products 41 CO2 regeneration tower 42 Solution heat exchanger 43 Reboiler 44 Circulating water cooler 45 Chilled water cooler 46 CO2 Buffer Tank 47 CO2 Compressor 48 Bottles or loaded into tank trucks 49 CO2 downstream production equipment 50 Heat Pump System 51 Steam 52 Condensate 53 Process Water 54 Cold water supply 55 Cold water return

Claims

1. Using ammonia to reduce sulfur oxides and CO in process gas 2 An integrated desulfurization and decarbonation process for removing 1) Using the desulfurization circulating liquid, SO is removed from the process gas. 2 providing a desulfurized process gas; 2) Removal of CO from the desulfurized process gas using a decarbonation circulating liquid 2 to provide a decarbonated process gas; and 3) removing free ammonia from the decarbonated process gas using the desulfurization circulating liquid from the oxidation chamber of the desulfurization circulating tank, and returning the desulfurization circulating liquid having absorbed the free ammonia to the desulfurization device; The method includes the steps of: The desulfurization circulating liquid includes a concentrated circulating liquid and an absorption circulating liquid, The concentrated circulating liquid has a pH of 1 to 6, an ammonium sulfite concentration of 0 to 0.2% and an ammonium sulfate concentration of 10 to 60%, and The absorption circulation liquid has a pH of 4.5 to 6.5, an ammonium sulfite concentration of 0.1 to 3% and an ammonium sulfate concentration of 10 to 38%, The decarbonation circulating liquid has a pH of 7-13, an ammonium bicarbonate concentration of 3-40% and an NH 3 / CO 2 molar ratio of 0.6-4.

2. Features: - the products of the process include ammonium sulfate fertilizer and ammonium bicarbonate fertilizer; CO in step 2) 2 The removal rate is in the range of 30 to 98%. The method comprises: producing ammonium bicarbonate fertilizer from a portion of the decarbonated circulating liquid in an ammonium bicarbonate post-treatment unit; and / or A part of the decarbonated circulating liquid is treated with CO 2 The gaseous CO 2 and the regeneration of the decarbonated circulating liquid is performed by CO 2 This is done in the playback system. The method comprises the step of: 2 Produce downstream products from gaseous CO 2 and / or using gaseous CO 2 and isolating said The method of claim 1 , comprising at least one of:

3. The CO 2 The operating parameters of the regeneration system include an operating temperature at the bottom of the column in the range of 90 to 150°C, an operating temperature at the top of the column in the range of 70 to 100°C, a regeneration pressure at the bottom of the column in the range of 0.2 to 0.7 MPa, and a gas velocity in the column in the range of 0.2 to 3 m / s; The downstream products are urea, soda ash, sodium bicarbonate, polycarbonate, food grade CO 2 , CO 2 comprising at least one of gas fertilizer and potassium bicarbonate; The method of claim 2 , further comprising at least one of:

4. Between steps 2) and 3), 4) removing free ammonia from the process gas using process water; and / or After step 3), 5) removing free ammonia from the process gas using process water; The method of claim 1 further comprising:

5. Features: SO from the process gas 2 The temperature of the removal is in the range of 5 to 55°C. CO from the process gas 2 The temperature of the removal is in the range of 0 to 45° C. The method of claim 1 , comprising at least one of:

6. Features: The desulfurization circulating liquid includes a concentrated circulating liquid and an absorption circulating liquid, The concentrated circulating liquid has a pH of 2 to 4.5, an ammonium sulfite concentration of 0 to 0.2% and an ammonium sulfate concentration of 10 to 60%, and The absorption circulation liquid has a pH of 4.8 to 6.2, an ammonium sulfite concentration of 0.1 to 3% and an ammonium sulfate concentration of 10 to 38%; The decarbonation circulating liquid has a pH of 7.5 to 11, a concentration of 10 to 22% ammonium bicarbonate and a concentration of 1.2 to 3 NH 3 / CO 2 having a molar ratio of SO from the process gas 2 The temperature of the removal is in the range of 15 to 50° C. CO from the process gas 2 The temperature of the removal is in the range of 5 to 40°C. The method of claim 1 , comprising at least one of:

7. An apparatus for carrying out the method according to any one of claims 1 to 6, the apparatus comprising an ammonia-based desulfurization functional area, an ammonia-based decarbonation functional area, an ammonia washing functional area, an ammonium sulfate post-treatment system, and an ammonium bicarbonate post-treatment system, ammonia is used as a desulfurization agent and a decarbonation agent, a process gas is first entered into the ammonia-based desulfurization functional area to be desulfurized and produce ammonium sulfate fertilizer, the desulfurized process gas enters the ammonia-based decarbonation functional area to remove carbon dioxide gas and produce an ammonium bicarbonate solution / slurry, the decarbonated process gas containing free ammonia enters the ammonia washing functional area to be washed with a desulfurization circulation liquid and further washed with process water, after the washing, the desulfurization circulation liquid and the process water solution are returned to the ammonia-based desulfurization functional area to become a desulfurization absorbent, and a part of the ammonium sulfate-containing ammonium bicarbonate solution is returned to the ammonia-based desulfurization functional area, 1. The apparatus includes a desulfurization circulation vessel having an oxidation chamber and an ammonia addition chamber in fluid communication with each other, the oxidation chamber configured to allow contact and reaction of at least a portion of the reflux liquid from the absorption section with an oxygen-containing gas and to remove at least a portion of its liquid phase for circulation to a particulate removal section and an ammonia scrubbing section of the ammonia-based desulfurization functional area, and the ammonia addition chamber in fluid communication with the oxidation chamber and configured to allow mixing of at least a portion of the reflux liquid from the absorption section with an ammonia absorbent and to remove a liquid stream therefrom for circulation to the absorption section.

8. 8. The apparatus of claim 7, wherein the ammonia scrubbing functional area is further configured to scrub the process gas with process water prior to scrubbing the process gas with the desulfurization circulation liquid, and wherein the ammonia-based desulfurization functional area, the ammonia-based decarbonation functional area, and the ammonia scrubbing functional area are disposed in one or more columns.

9. 8. The apparatus according to claim 7, wherein the ammonia-based desulfurization functional area is divided into a plurality of zones including a cooling concentration zone, an absorption zone, and a particulate removal zone, each zone being provided with at least one spray bed, and a device / component that allows gas to pass between any two adjacent zones.

10. The particulate removal zone comprises: a first particulate removal portion configured to be washed with a concentrated circulating ammonium sulfate-containing solution; and a second particulate removal section configured to be washed with a dilute, circulating ammonium sulfate-containing solution; a device / component is provided between the first particulate removal portion and the second particulate removal portion to allow gas to pass therethrough; the first particulate removal section utilizes a concentrated ammonium sulfate-containing solution having an ammonium sulfate concentration in the range of 10-38% and a pH in the range of 2.5-7.5; and 10. The apparatus of claim 9, wherein the second particulate removal portion utilizes a dilute ammonium sulfate containing solution having an ammonium sulfate concentration in the range of 0-5% and a pH in the range of 3-7.

11. The ammonia-based desulfurization functional area includes a cooling device configured to maintain the temperature of the desulfurized process gas in the range of 5 to 55 ° C., 10. The device according to claim 9, wherein circulating water and / or cold water is used as a coolant for the cooling equipment.

12. the first particulate removal section utilizes a concentrated ammonium sulfate-containing solution having an ammonium sulfate concentration in the range of 12-30% and a pH in the range of 3-5.5; and 11. The apparatus of claim 10, wherein the second particulate removal portion utilizes a dilute ammonium sulfate containing solution having an ammonium sulfate concentration in the range of 0.02-2% and a pH in the range of 3-7.

13. The apparatus of claim 10, wherein the ammonia-based desulfurization functional area includes cooling equipment configured to maintain the temperature of the desulfurized process gas in the range of 15 to 50°C.

14. 12. The apparatus according to claim 11, wherein the cooling equipment of the ammonia-based desulfurization functional area is arranged on a circulation path configured to transport the desulfurization circulation liquid and cools the desulfurization circulation liquid and thus the process gas after desulfurization, or alternatively, directly cools the process gas on the process gas / exhaust gas conduit of the ammonia-based desulfurization functional area.

15. 8. The apparatus of claim 7, wherein the ammonia-based decarbonation functional area includes cooling equipment configured to maintain the temperature of the decarbonated process gas in the range of 0-45°C.

16. 8. The apparatus of claim 7, wherein the ammonia-based decarbonation functional area includes cooling equipment configured to maintain the temperature of the decarbonated process gas in the range of 5 to 40°C.

17. Features: The desulfurization circulating liquid used for ammonia washing is derived from an ammonium sulfate-containing washing liquid used in the particulate removal section of the ammonia-based desulfurization functional area, and the pH of the ammonium sulfate-containing washing liquid is controlled to 2.5 to 7.5, and the desulfurization circulating liquid after being used for the ammonia washing is returned to the ammonia-based desulfurization functional area for desulfurization; The desulfurization circulating liquid used for ammonia washing is derived from an ammonium sulfate-containing washing liquid used in the absorption section of the ammonia-based desulfurization functional area, and the pH of the ammonium sulfate-containing washing liquid is controlled to 3 to 7, while the desulfurization circulating liquid after being used for the ammonia washing is returned to the absorption section of the ammonia-based desulfurization functional area for desulfurization; The ammonia concentration in the desulfurization circulating liquid used for ammonia washing is controlled to 0 to 5%, and a part of the aqueous solution obtained after the ammonia washing is introduced into the circulating liquid in the particulate removal zone of the ammonia-based desulfurization functional area as makeup water; The apparatus of claim 7 , further comprising at least one of:

18. The apparatus according to claim 10, wherein a part of the dilute ammonium sulfate-containing solution is pumped and sent to a purification membrane separation device for separation, the purified water produced is used as makeup water for the ammonia washing functional area to control the ammonia concentration in the washing water and the concentration of the dilute ammonium sulfate-containing solution for desulfurization washing, and the excess is discharged from the device for external use, and the concentrated liquid obtained by the separation is introduced into the absorption section of the ammonia-based desulfurization functional area.

19. Features: Each of the ammonia-based desulfurization functional area, the ammonia-based decarbonation functional area, and the ammonia washing functional area utilizes one or a combination of a spray type absorber, a plate type absorber, a packed column type absorber, and a floating valve type absorber; - subjecting the ammonium sulfate slurry produced by desulfurization to solid-liquid separation, drying, and packaging into ammonium sulfate product or directly producing wet ammonium sulfate product; - subjecting the ammonium bicarbonate slurry produced by the decarbonation to solid-liquid separation, returning the separated solution to the decarbonation equipment, and drying the separated ammonium bicarbonate for packaging as a product or directly producing it as a wet ammonium bicarbonate product; Heating a portion or all of the ammonium bicarbonate solution / slurry produced by decarbonation to produce CO 2 and generating an ammonia solution and returning said ammonia solution to said ammonia-based decarbonation functional area for further use. ・CO 2 for the production of downstream products, enhanced oil recovery, beverage production or underground sequestration; The ammonia-based desulfurization functional area is configured to have the following process parameters: 1) A superficial gas flow velocity of 0.5 to 5 m / s; 2) 4 to 100 m 3 / m 2 - Circulating liquid spray density of each spray layer over time; 3) a circulating fluid temperature of 5 to 55°C; and 4) Circulating fluid pH from 1 to 7; being configured to operate under The ammonia-based decarbonation functional area is controlled by the following process parameters: 1) a superficial gas velocity of 0.1 to 5 m / s; 2) a temperature of 5 to 40°C, and 3) Circulating fluid pH of 7 to 11; being configured to operate under The ammonia washing functional area is controlled by the following process parameters: 1) a superficial gas velocity of 0.25 to 5 m / s; 2) a temperature of 0 to 50°C, and 3) Circulating fluid pH of 3 to 10; being configured to operate under the device further comprises a heat pump system configured to provide the chilled water required for cooling, the temperature of the chilled water from the heat pump system being in the range of 3-25°C; The apparatus is adapted to control the following process parameters: A temperature for regeneration at the bottom of the column of 90 to 150° C. Temperature for regeneration at the top of the column from 6 to 100° C. A pressure for regeneration at the bottom of the column of 0.2 to 0.7 MPa; and Gas velocity in the regenerator of 0.2-3 m / s; and a CO regeneration system configured to regenerate the decarbonated circulating liquid under 2 further comprising a regeneration tower; The apparatus of claim 7 , further comprising at least one of:

20. Features: Each of the ammonia-based desulfurization functional area, the ammonia-based decarbonation functional area, and the ammonia washing functional area utilizes one or a combination of a spray type absorber, a plate type absorber, a packed column type absorber, and a floating valve type absorber; - subjecting the ammonium sulfate slurry produced by desulfurization to solid-liquid separation, drying, and packaging into ammonium sulfate product or directly producing wet ammonium sulfate product; - subjecting the ammonium bicarbonate slurry produced by the decarbonation to solid-liquid separation, returning the separated solution to the decarbonation equipment, and drying the separated ammonium bicarbonate for packaging as a product or directly producing it as a wet ammonium bicarbonate product; Heating a portion or all of the ammonium bicarbonate solution / slurry produced by decarbonation to produce CO 2 and generating an ammonia solution and returning said ammonia solution to said ammonia-based decarbonation functional area for further use. ・CO 2 for the production of downstream products, enhanced oil recovery, beverage production or underground sequestration; The ammonia-based desulfurization functional area is configured to have the following process parameters: 1) A superficial gas flow velocity of 2 to 4 m / s; 2) 8 to 80 meters 3 / m 2 - Circulating liquid spray density of each spray layer over time; 3) a circulating fluid temperature of 20 to 40°C; and 4) Circulating fluid pH from 1 to 7; being configured to operate under The ammonia-based decarbonation functional area is controlled by the following process parameters: 1) a superficial gas velocity of 0.1 to 5 m / s; 2) a temperature between 10 and 30°C, and 3) Circulating fluid pH of 7 to 11; being configured to operate under The ammonia washing functional area is controlled by the following process parameters: 1) a superficial gas velocity of 0.25 to 5 m / s; 2) a temperature of 3 to 40°C, and 3) Circulating fluid pH of 3 to 10; being configured to operate under the device further comprises a heat pump system configured to provide the chilled water required for cooling, the temperature of the chilled water from the heat pump system being in the range of 5-10°C; The apparatus is adapted to control the following process parameters: A temperature for regeneration at the bottom of the column of 100 to 130° C. Temperature for regeneration at the top of the column of 70-90° C. A pressure for regeneration at the bottom of the column of 0.3 to 0.5 MPa; and Gas velocity in the regenerator of 0.3 to 2 m / s; and a CO regeneration system configured to regenerate the decarbonated circulating liquid under 2 further comprising a regeneration tower; and the apparatus further comprising a process water inlet disposed at an upper portion of the regeneration tower; Gaseous CO obtained from the regeneration tower 2 However, urea, soda ash, sodium bicarbonate, polycarbonate, food grade CO 2 , CO 2 used in the manufacture of downstream products including gas fertilizer, potassium bicarbonate, enhanced oil recovery, beverage production, or welding, or marine or underground sequestration; The device includes a solution heat exchanger, a reboiler, a circulating water cooler, a cold water cooler, a CO 2 Buffer tank and CO 2 The decarbonation circulation pump further includes a compressor, and the decarbonation circulation pump circulates a part of the solution at the outlet through the solution heat exchanger to CO 2 The gas is sent to a regeneration tower, and gaseous CO is extracted from the top of the tower. 2 is taken out, cooled by the circulating water cooler and the cold water cooler, and then the CO 2 The CO is sent to a buffer tank. 2 The device according to claim 7, wherein the compressed material is compressed by a compressor and then discharged to the outside.

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