Integrated system for regenerating sodium bicarbonate and recovering ammonia

Abstract

The present application relates to an integrated system for regenerating sodium bicarbonate and recovering ammonia, and an integrated method for regenerating sodium bicarbonate and recovering ammonia by using same. According to the integrated system for regenerating sodium bicarbonate and recovering ammonia, and the integrated method for regenerating sodium bicarbonate and recovering ammonia by using same, of the present application, sodium bicarbonate can be regenerated and ammonia can be recovered from ammonium sulfate wastewater, generated during sodium bicarbonate regeneration, so as to be reused as ammonia water, and thus the cost of purchasing ammonia water required for process operation can be reduced, and additional operating revenue can be created through the commercialization of the generated ammonia water.

Description

Integrated system for bicarbonate regeneration and ammonia recovery

[0001] The present application relates to an integrated system for regeneration of sodium bicarbonate and ammonia recovery, and an integrated method for regeneration of sodium bicarbonate and ammonia recovery using the same.

[0002] The exhaust gas generated during the sintering process in steel mills contains sulfur oxides (SO X ) and other harmful substances. The process of removing sulfur oxides from exhaust gas is called the desulfurization process, and the desulfurization agent sodium bicarbonate (NaHCO3) is used to remove sulfur oxides from exhaust gas. In this desulfurization process, desulfurization waste containing sodium sulfate (Na2SO4), called sodium bicarbonate dust, is generated. Desulfurization waste has high solubility and contains a large amount of impurities, making it difficult to recycle, so it is usually disposed of entirely by landfill.

[0003] However, landfilling desulfurization waste incurs excessive costs, driving up process and product prices. It also negatively impacts the local environment, including the ecosystem. Consequently, the treatment of waste generated during desulfurization processes has been identified as a critical area for improvement, and ongoing research and technological development are underway.

[0004] To solve this problem, Patent Document 1 proposed a sodium bicarbonate regeneration process in which desulfurization waste is reacted with ammonia and carbon dioxide to regenerate sodium bicarbonate (NaHCO3), a desulfurization agent, and then used.

[0005] However, Patent Document 1 performs the sodium bicarbonate regeneration without recovering ammonia in the ammonium sulfate ((NH4)2SO4) wastewater generated during the sodium bicarbonate regeneration, and thus has a disadvantage in that the operating cost increases due to the additional input of ammonia water in the sodium bicarbonate regeneration process.

[0006] Therefore, to compensate for these shortcomings, an integrated system for sodium bicarbonate regeneration and ammonia recovery is required, which can recover ammonia from ammonium sulfate wastewater generated during sodium bicarbonate regeneration and reuse it as ammonia water.

[0007] The object of the present application is to provide an integrated system for regenerating sodium bicarbonate and recovering ammonia, which can recover ammonia from ammonium sulfate wastewater generated during regeneration of sodium bicarbonate and reuse it as ammonia water, and an integrated method for regenerating sodium bicarbonate and recovering ammonia using the same.

[0008] In addition, the object of the present application is to provide an integrated system for regeneration of sodium bicarbonate and ammonia recovery that can further improve efficiency, and an integrated method for regeneration of sodium bicarbonate and ammonia recovery using the same.

[0009] In order to solve the above problems, the integrated system for regenerating and recovering sodium bicarbonate of the present application includes a sodium bicarbonate dust dissolution tank for dissolving sodium bicarbonate dust to produce a sodium bicarbonate dust solution; an ammonium bicarbonate production reactor for reacting carbon dioxide and ammonia water to produce an ammonium bicarbonate solution; a carbonation reactor for reacting the sodium bicarbonate dust solution and the ammonium bicarbonate solution to produce a regenerated sodium bicarbonate solution; a first dehydrator for dehydrating the regenerated sodium bicarbonate solution produced in the carbonation reactor to separate it into regenerated sodium bicarbonate and ammonium sulfate wastewater; an ammonia recovery tower for recovering ammonia from the ammonium sulfate wastewater; at least one condenser for condensing ammonia recovered in the ammonia recovery tower to form ammonia water; and an ammonia water storage device for storing ammonia water and supplying the stored ammonia water to the ammonium bicarbonate production reactor.

[0010] The above-described integrated system for regeneration of sodium bicarbonate and recovery of ammonia may further include an ammonia scrubber capable of introducing ammonia discharged into the atmosphere from at least one of the ammonium bicarbonate production reactor, the carbonation reactor, the first dehydrator, the ammonia recovery tower, one or more of the condensers, and the ammonia water storage device, adding sulfuric acid to the introduced ammonia to form ammonium sulfate, and supplying the formed ammonium sulfate to the ammonium sulfate wastewater.

[0011] In addition, the integrated system for regeneration of the bicarbonate and recovery of ammonia may further include a flue gas pretreatment device capable of pretreating flue gas to supply flue gas containing carbon dioxide to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor, and may further include a gas holder capable of recovering and storing gas discharged from at least one of the ammonium bicarbonate production reactor and the carbonation reactor, and supplying the stored gas to the flue gas containing carbon dioxide or the ammonia scrubber.

[0012] In addition, the above-described integrated system for regeneration of carbon dioxide and recovery of ammonia can supply the gas as flue gas containing carbon dioxide when the concentration of carbon dioxide in the gas stored in the gas holder is 10% or more, and can supply the gas to the ammonia scrubber when the concentration of carbon dioxide in the gas stored in the gas holder is less than 10%.

[0013] Additionally, the above-described integrated system for regeneration of sodium bicarbonate and recovery of ammonia may further include a cooler that supplies a cooling medium to at least one of the ammonium bicarbonate production reactor, the carbonation reactor, and the one or more condensers.

[0014] In addition, the above-described integrated system for regeneration and ammonia recovery may further include a first heat exchanger provided at the front end of the ammonia recovery tower, in which heat of the ammonia-degassed wastewater discharged from the ammonia recovery tower is exchanged with the ammonium sulfate wastewater.

[0015] Additionally, the latent heat of the ammonia-degassed wastewater may be 80°C or higher and 100°C or lower.

[0016] In addition, the above-described integrated system for regeneration and ammonia recovery may further include a separator provided in front of the first heat exchanger to separate solids from ammonium sulfate wastewater, and a second heat exchanger provided in front of the separator to exchange heat between the wastewater from which ammonia has been removed and discharged from the first heat exchanger and the ammonium sulfate wastewater.

[0017] In addition, the above-described integrated system for regeneration and ammonia recovery may further include a water jacket that is provided to surround the periphery of the above-described powder dissolution tank and to which heat of the wastewater from which ammonia is degassed and discharged from the second heat exchanger is supplied.

[0018] In addition, the integrated method for regenerating and recovering sodium bicarbonate of the present application comprises: a sodium bicarbonate dust dissolution step of dissolving sodium bicarbonate dust in a sodium bicarbonate dust dissolution tank to produce a sodium bicarbonate dust solution; an ammonium bicarbonate production step of reacting carbon dioxide and ammonia water in an ammonium bicarbonate production reactor to produce an ammonium bicarbonate solution; a carbonation reaction step of reacting the sodium bicarbonate dust solution and the ammonium bicarbonate solution in a carbonation reactor to produce a regenerated sodium bicarbonate solution; a first dehydration step of dehydrating the regenerated sodium bicarbonate solution produced in the carbonation reaction step in a first dehydrator to separate it into regenerated sodium bicarbonate and ammonium sulfate wastewater; an ammonia recovery step of recovering ammonia from the ammonium sulfate wastewater using an ammonia recovery tower; a condensation step of condensing the ammonia recovered in the ammonia recovery step in one or more condensers to form ammonia water; And it includes an ammonia water storage step capable of storing ammonia water in an ammonia water storage device and supplying the stored ammonia water to the ammonium bicarbonate production reactor.

[0019] In addition, the integrated method for regenerating sodium bicarbonate and recovering ammonia may further include an ammonia scrubbing step in which ammonia discharged into the atmosphere in at least one of the ammonium bicarbonate production step, the carbonation reaction step, the first dehydration step, the ammonia recovery step, the condensation step, and the ammonia water storage step is introduced into an ammonia scrubber, sulfuric acid is added to the introduced ammonia to form ammonium sulfate, and the formed ammonium sulfate is supplied to the ammonium sulfate wastewater.

[0020] In addition, the integrated method for regenerating and recovering ammonia may further include a pretreatment step in which exhaust gas is pretreated in a exhaust gas pretreatment device to supply exhaust gas containing carbon dioxide to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor, and may further include a gas holding step in which gas discharged from at least one of the ammonium bicarbonate production step and the carbonation reaction step is recovered and stored in a gas holder, and the stored gas is supplied to the exhaust gas containing carbon dioxide or the ammonia scrubber.

[0021] In addition, the integrated method for regeneration of the ammonia and recovery of the ammonia can supply the gas as flue gas containing carbon dioxide when the concentration of carbon dioxide in the gas stored in the gas holder is 10% or more, and supply the gas to the ammonia scrubber when the concentration of carbon dioxide in the gas stored in the gas holder is less than 10%.

[0022] In addition, the integrated method for regeneration of the sodium bicarbonate and recovery of ammonia may further include a cooling step of supplying a cooling medium from a cooler to at least one of the ammonium bicarbonate production reactor, the carbonation reactor, and the at least one condenser.

[0023] In addition, the above-described integrated method for regeneration of the ammonia and recovery of the ammonia may further include a first heat exchange step in which a first heat exchanger is provided at the front end of the ammonia recovery tower, and heat of the ammonia-degassed wastewater discharged from the ammonia recovery tower is exchanged with the ammonium sulfate wastewater.

[0024] In addition, the integrated method of regeneration of the ammonia and recovery of the ammonia may have a latent heat of the wastewater from which the ammonia has been removed of 80°C or more and 100°C or less.

[0025] In addition, the integrated method for regeneration of the sodium bicarbonate and recovery of ammonia may further include a separation step in which a separator is provided in front of the first heat exchanger to separate solids from the ammonium sulfate wastewater, and a second heat exchange step in which a second heat exchanger is provided in front of the separator to exchange heat between the wastewater from which ammonia is degassed and discharged in the first heat exchange step and the ammonium sulfate wastewater.

[0026] In addition, the integrated method for regeneration of the sodium bicarbonate and recovery of ammonia may further include a heat supply step in which a water jacket is provided to surround the periphery of the sodium bicarbonate dust dissolution tank, and heat of the wastewater from which ammonia has been degassed and discharged in the second heat exchange step is supplied to the water jacket.

[0027] According to the integrated system for regeneration and ammonia recovery of the present application, and the integrated method for regeneration and ammonia recovery using the same, it is possible to recover ammonia from ammonium sulfate wastewater generated during regeneration of sodium bicarbonate along with regeneration of sodium bicarbonate and reuse it as ammonia water, thereby reducing the cost of purchasing ammonia water required for process operation, and generating additional operating profits through commercialization of the generated ammonia water.

[0028] In addition, the integrated system for regeneration and ammonia recovery of the present application and the integrated method for regeneration and ammonia recovery using the same can not only reduce costs by further improving efficiency, but also provide a more environmentally friendly process by significantly reducing energy.

[0029] FIG. 1 is a block diagram schematically illustrating an integrated system for regeneration of ammonia water and recovery of ammonia water according to one embodiment of the present application.

[0030] Hereinafter, the integrated system for regeneration of sodium bicarbonate and recovery of ammonia water of the present application will be described with reference to the attached drawings. The attached drawings are exemplary, and the integrated system for regeneration of sodium bicarbonate and recovery of ammonia water of the present application is not limited to the attached drawings.

[0031] FIG. 1 is a block diagram schematically showing an integrated system for regeneration of sodium bicarbonate and recovery of ammonia water according to one embodiment of the present application. As shown in FIG. 1, the integrated system for regeneration of sodium bicarbonate and recovery of ammonia water of the present application includes a sodium bicarbonate dust dissolution tank (1), an ammonium bicarbonate production reactor (2), a carbonation reactor (3), a first dehydrator (4), an ammonia recovery tower (5), a condenser (6), and an ammonia water storage device (7). According to the integrated system for regeneration of sodium bicarbonate and recovery of ammonia of the present application, it is possible to recover ammonia from ammonium sulfate wastewater generated during regeneration of sodium bicarbonate and reuse it as ammonia water, thereby reducing the purchase cost of ammonia water required for process operation, and generating additional operating profits through commercialization of the generated ammonia water.

[0032] The above-mentioned sodium bicarbonate dust dissolution tank (1) uses sodium bicarbonate (NaHCO3 (solid)), a desulfurizing agent, from the exhaust gas generated during the sintering process of a steel mill to remove sulfur oxides (SO). X ) is supplied as a treatment tank for producing a sodium bicarbonate dust solution by dissolving the supplied sodium bicarbonate dust in a solvent. At this time, water (H2O(liquid)) can be used as the solvent. In addition, when producing the sodium bicarbonate dust solution, the sodium bicarbonate dust and the solvent can be stirred at a temperature of 20°C or more and 30°C or less. In addition, the sodium bicarbonate dust may have a solubility in the solvent of 210 g / L or more and 450 g / L or less, or 210 g / L or more and 440 g / L or less.

[0033] In one example, the above-described integrated system for regeneration and ammonia recovery may further include a sodium bicarbonate dust storage device (8). The sodium bicarbonate dust storage device (8) is a device that stores sodium bicarbonate dust for supply to the sodium bicarbonate dust dissolution tank (1), and may be provided at the front end of the sodium bicarbonate dust dissolution tank (1) and connected to the sodium bicarbonate dust dissolution tank (1) through a pipe. As used herein, the term "provided at the front end" means located at the front end in the process flow. In addition, the term "provided at the rear end" as used herein means located at the rear end in the process flow.

[0034] In another example, the integrated system for regeneration and ammonia recovery may further include a second dehydrator (9). The second dehydrator (9) is a treatment tank into which the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution tank (1) is introduced, and which dehydrates the introduced sodium bicarbonate dust solution to separate it into insoluble matter and a sodium bicarbonate dust solution (Na2SO4(aq.)) from which the insoluble matter has been removed. The second dehydrator (9) may be provided at the rear end of the sodium bicarbonate dust dissolution tank (1) and may be connected to the sodium bicarbonate dust dissolution tank (1) through a pipe. The integrated system for regeneration and ammonia recovery may further include the second dehydrator (9), thereby producing a sodium bicarbonate dust solution from which insoluble matter has been removed from the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution tank (1).

[0035] In another example, the above-described integrated system for regeneration and ammonia recovery may further include a sodium bicarbonate dust solution storage device (10). The sodium bicarbonate dust solution storage device (10) is a device that receives the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution tank (1), specifically, the sodium bicarbonate dust solution from which insoluble matter has been removed through the second dehydrator (9), and stores the introduced sodium bicarbonate dust solution. The sodium bicarbonate dust solution storage device (10) may be provided at the rear end of the sodium bicarbonate dust dissolution tank (1) and connected to the sodium bicarbonate dust dissolution tank (1), or may be provided at the rear end of the second dehydrator (9) and connected to the second dehydrator (9). The above-described integrated system for regeneration of sodium bicarbonate and ammonia recovery further includes the sodium bicarbonate dust solution storage device (10), so that the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution tank (1) or the sodium bicarbonate dust solution from which insolubles have been removed through the second dehydrator (9) can be stored in the sodium bicarbonate dust solution storage device (10), and thus, without waiting until the reaction in the carbonation reactor (3) is completed and the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution tank (1) or the sodium bicarbonate dust solution from which insolubles have been removed through the second dehydrator (9) can be supplied to the carbonation reactor (3), the sodium bicarbonate dust solution in the sodium bicarbonate dust dissolution tank (1) or the second dehydrator (9) can be supplied to the next step, and the process of producing the sodium bicarbonate dust solution in the sodium bicarbonate dust dissolution tank (1) or the second dehydrator (9) can be continuously performed. In addition, the above-mentioned sodium bicarbonate solution storage device (10) can store the above-mentioned sodium bicarbonate solution while maintaining a temperature of 20°C or higher and 30°C or lower.

[0036] The above ammonium bicarbonate production reactor (2) is a reactor that produces an ammonium bicarbonate solution (NH4HCO3(aq.)) for producing a regenerated sodium bicarbonate solution by reacting with the above sodium bicarbonate dust solution, and produces an ammonium bicarbonate solution by reacting carbon dioxide (CO2(gas)) and ammonia water (NH4OH(liquid)).

[0037] The above carbon dioxide may be carbon dioxide obtained from exhaust gas in the atmosphere. In one example, the integrated system for regeneration and ammonia recovery may further include a exhaust gas pretreatment device (11). The exhaust gas pretreatment device (11) pretreats exhaust gas existing in the atmosphere to remove dust and sulfur oxides (SO) from the exhaust gas. X ), and nitrogen oxides (NOx) to generate exhaust gas containing carbon dioxide, and supply the generated exhaust gas containing carbon dioxide to the ammonium bicarbonate production reactor (2), or to both the ammonium bicarbonate production reactor (2) and the carbonation reactor (3), wherein the device is provided at a front end of the ammonium bicarbonate production reactor (2) and can be connected to the ammonium bicarbonate production reactor (2) through a pipe. The integrated system for sodium bicarbonate regeneration and ammonia recovery can further include an exhaust gas pretreatment device (11), thereby reducing the purchase cost of the carbon dioxide.

[0038] When carbon dioxide is generated through the aforementioned flue gas pretreatment device (11), the carbon dioxide may be generated in a state where it is included in the flue gas, resulting in low purity. To solve this problem, the integrated system for sodium bicarbonate regeneration and ammonia recovery may further include a carbon dioxide capture device (12). The carbon dioxide capture device (12) is a device that receives flue gas containing carbon dioxide, captures and stores carbon dioxide from the introduced flue gas containing carbon dioxide, and additionally supplies the stored carbon dioxide to the ammonium bicarbonate production reactor (2), or to both the ammonium bicarbonate production reactor (2) and the carbonation reactor (3), and is provided at the rear end of the flue gas pretreatment device (11), is connected to the flue gas pretreatment device (11) through one pipe, and is connected to the ammonium bicarbonate production reactor (2) through another pipe, or may be connected to both the ammonium bicarbonate production reactor (2) and the carbonation reactor (3). The above-mentioned integrated system for regeneration of the bicarbonate and recovery of ammonia can further improve the purity of carbon dioxide by further including the carbon dioxide capture device (12).

[0039] The ammonia water can be supplied from the ammonia water storage device (7) described later, or can be supplied from ammonia water manufactured at a concentration of 20% or more and 30% or less, specifically 25% or more and 30% or less, and the ammonia water supplied to the ammonium bicarbonate manufacturing reactor (2) can be stored in the ammonia water supply device (22).

[0040] In another example, the ammonium bicarbonate production reactor (2) may further include a cooling device (not shown). The cooling device may be provided within the ammonium bicarbonate production reactor (2) as a device for maintaining the internal temperature of the ammonium bicarbonate production reactor (2). At this time, the internal temperature of the ammonium bicarbonate production reactor (2) may be maintained at 10°C or higher and 15°C or lower.

[0041] The above-described integrated system for regeneration of sodium bicarbonate and recovery of ammonia may further include an ammonium bicarbonate storage device (13). The ammonium bicarbonate storage device (13) is a device into which the ammonium bicarbonate solution produced in the ammonium bicarbonate production reactor (2) is introduced and which stores the introduced ammonium bicarbonate solution. The ammonium bicarbonate storage device (13) is provided at the rear end of the ammonium bicarbonate production reactor (2) and may be connected to the ammonium bicarbonate production reactor (2) through a pipe. The above-described integrated system for sodium bicarbonate regeneration and ammonia recovery further includes the ammonium bicarbonate storage device (13), so that the ammonium bicarbonate solution produced through the ammonium bicarbonate production reactor (2) can be stored in the ammonium bicarbonate storage device (13), and thus, the ammonium bicarbonate solution can be supplied to the next step without waiting until the reaction in the ammonium bicarbonate production reactor (2) is completed and can be supplied to the carbonation reactor (3), and the process of producing the ammonium bicarbonate solution in the ammonium bicarbonate production reactor (2) can be continuously performed.

[0042] The above carbonation reactor (3) is supplied with a sodium bicarbonate dust solution and an ammonium bicarbonate solution, and the supplied sodium bicarbonate dust solution and ammonium bicarbonate solution are reacted to produce a regenerated sodium bicarbonate solution (2NaHCO3(solid)). + 2(NH4)2SO4(aq.)) is a reactor for producing the sodium bicarbonate dust solution and the ammonium bicarbonate solution. The sodium bicarbonate dust solution and the ammonium bicarbonate solution may be produced in the sodium bicarbonate dust dissolution tank (1) or the second dehydrator (9), and the ammonium bicarbonate production reactor (2), respectively, and may also be stored in the sodium bicarbonate dust solution storage device (10) and the ammonium bicarbonate storage device (13), respectively. The carbonation reactor (3) is provided at the rear end of each of the sodium bicarbonate dust dissolution tank (1) or the second dehydrator (9), and the ammonium bicarbonate production reactor (2), and is connected to each of the sodium bicarbonate dust dissolution tank (1) or the second dehydrator (9), and the ammonium bicarbonate production reactor (2) through a pipe, or specifically, is provided at the rear end of each of the sodium bicarbonate dust solution storage device (10) and the ammonium bicarbonate storage device (13), and is connected to each of the sodium bicarbonate dust solution storage device (10) and the ammonium bicarbonate storage device (13) through a pipe. At this time, the sodium bicarbonate dust solution and the ammonium bicarbonate solution supplied to the carbonation reactor (3) can be produced as the regenerated sodium bicarbonate solution at a molar ratio of sodium (Na) and ammonia (NH3) of 1:0.9 or more and 1.1 or less.

[0043] In one example, the carbonation reactor (3) may further include supplying carbon dioxide from the exhaust gas pretreatment device (11) or the carbon dioxide capture device (12). That is, the carbonation reactor (3) may be provided at the rear end of the exhaust gas pretreatment device (11) and further connected to the exhaust gas pretreatment device (11) through a pipe, or may be provided at the rear end of the carbon dioxide capture device (12) and further connected to the carbon dioxide capture device (12) through a pipe. By further supplying carbon dioxide to the carbonation reactor (3) from the exhaust gas pretreatment device (11) or the carbon dioxide capture device (12), the reaction efficiency can be further improved.

[0044] In another example, the carbonation reactor (3) may further include a cooling device (not shown). The cooling device may be provided within the carbonation reactor (3) as a device for maintaining the internal temperature of the carbonation reactor (3). In this case, the internal temperature of the carbonation reactor (3) may be maintained at 10°C or higher and 15°C or lower.

[0045] The above first dehydrator (4) is a treatment tank into which the regenerated sodium bicarbonate solution produced in the carbonation reactor (3) is introduced, and which dehydrates the introduced regenerated sodium bicarbonate solution to separate it into regenerated sodium bicarbonate (NaHCO3 (solid)) and ammonium sulfate wastewater ((NH4)2SO4 (aq.)). It is provided at the rear end of the carbonation reactor (3) and is connected to the carbonation reactor (3) through a pipe. The above-described integrated system for regeneration of sodium bicarbonate and ammonia recovery can produce regenerated sodium bicarbonate from which ammonium sulfate wastewater has been removed from the sodium bicarbonate solution produced in the carbonation reactor (3) by including the first dehydrator (4).

[0046] In one example, the integrated system for regeneration and ammonia recovery of the sodium bicarbonate may further include a dryer (14). The dryer (14) is a device for drying the regenerated sodium bicarbonate dehydrated in the first dehydrator (4), and may be provided at the rear end of the first dehydrator (4) and connected to the first dehydrator (4) through a pipe. At this time, the drying may be performed at a temperature of 20°C or more and 40°C or less for 48 hours or more, and then at a temperature of 90°C or more and 110°C or less for 5 minutes or less. By drying the regenerated sodium bicarbonate dehydrated in the first dehydrator (4) through the dryer (14), regenerated sodium bicarbonate that can be reused as a desulfurization agent can be manufactured.

[0047] In another example, the above-described integrated system for sodium bicarbonate regeneration and ammonia recovery may further include an ammonium sulfate wastewater pretreatment device (15). The ammonium sulfate wastewater pretreatment device (15) is a device that removes impurities contained in the ammonium sulfate wastewater discharged from the first dehydrator (4), and may be installed at the rear end of the first dehydrator (4) and connected to the first dehydrator (4) through a pipe. At this time, the impurities may be chlorine and / or particulate matter.

[0048] In another example, the above-described integrated system for regeneration of sodium bicarbonate and ammonia recovery may further include an ammonium sulfate wastewater storage device (16). The ammonium sulfate wastewater storage device (16) is a device that receives pretreated ammonium sulfate wastewater from the ammonium sulfate wastewater pretreatment device (15) and stores the introduced ammonium sulfate wastewater. The ammonium sulfate wastewater storage device (16) is provided at the rear end of the ammonium sulfate wastewater pretreatment device (15) and may be connected to the ammonium sulfate wastewater pretreatment device (15) through a pipe. The above-described integrated system for sodium bicarbonate regeneration and ammonia recovery further includes the ammonium sulfate wastewater storage device (16), so that ammonium sulfate wastewater from which impurities have been removed through the ammonium sulfate wastewater pretreatment device (15) can be stored in the ammonium sulfate wastewater storage device (16), and thus, the ammonium sulfate wastewater from which impurities have been removed can be supplied to the next step without waiting until it has been pretreated in the ammonium sulfate wastewater pretreatment device (15) and can be supplied to the ammonia recovery tower (5), and the process of pretreating ammonium sulfate wastewater in the ammonium sulfate wastewater pretreatment device (15) can be repeatedly performed.

[0049] In another example, the integrated system for sodium bicarbonate regeneration and ammonia recovery may further include a pH adjustment tank (17). The pH adjustment tank (17) is a treatment tank into which ammonium sulfate wastewater separated from the first dehydrator (4), ammonium sulfate wastewater pretreated in the ammonium sulfate wastewater pretreatment device (15), or ammonium sulfate wastewater stored in the ammonium sulfate wastewater storage device (16) flows, and which increases the pH of the flowing ammonium sulfate wastewater to form a solid content in the ammonium sulfate wastewater, and is provided at the rear end of the first dehydrator (4), the ammonium sulfate wastewater pretreatment device (15), or the ammonium sulfate wastewater storage device (16), and may be connected to the first dehydrator (4), the ammonium sulfate wastewater pretreatment device (15), or the ammonium sulfate wastewater storage device (16) through a pipe. At this time, the pH adjustment tank (17) can add a basic pH adjuster to increase the pH of the ammonium sulfate wastewater, and can increase the pH to 11 to 13. As a result, a solid may be formed in the ammonium sulfate wastewater, and the solid may be gypsum (CaSO4). As the basic pH adjuster, a pH adjuster known in the art can be used, and for example, sodium hydroxide or ammonium hydroxide can be used.

[0050] In another example, the integrated system for regeneration of sodium bicarbonate and ammonia recovery may further include a separator (18). The separator (18) is a device that receives ammonium sulfate wastewater that has passed through the pH adjustment tank (17), pressurizes the introduced ammonium sulfate wastewater, and separates it into solids and ammonium sulfate wastewater from which the solids have been removed. The separator (18) is provided at the rear end of the pH adjustment tank (17), and may be connected to the pH adjustment tank (17) through a pipe, or may be connected to a second heat exchanger (20) to be described later. The integrated system for regeneration of sodium bicarbonate and ammonia recovery may further include the separator (18), thereby separating solids from the ammonium sulfate wastewater, and using the separated solids as a product through an additional drying process.

[0051] The above ammonia recovery tower (5) is a device that receives ammonium sulfate wastewater separated from the first dehydrator (4), specifically, ammonium sulfate wastewater whose pH has been adjusted in the pH adjustment tank (17) or ammonium sulfate wastewater that has passed through the separator (18), and recovers ammonia from the introduced ammonium sulfate wastewater, and is provided at the rear end of the first dehydrator (4) and connected to the first dehydrator (4) through a pipe, or specifically, is provided at the rear end of the pH adjustment tank (17) and connected to the pH adjustment tank (17) through a pipe, or is provided at the rear end of the separator (18) and connected to the separator (18) through a pipe, or is provided at the rear end of the first heat exchanger (19) to be described later and connected to the first heat exchanger (19) through a pipe. Specifically, the ammonia recovery tower (5) includes three or more stages, and may be provided with a filling material to maximize the reaction efficiency of liquid and gas within the stages. At this time, stainless steel, plastic, or ceramic may be used as the filling material.

[0052] Ammonium sulfate wastewater is introduced into the uppermost stage of the multiple stages of the ammonia recovery tower (5), and steam of 1.5 bar or more and 5 bar or less can be injected into the lowermost stage of the multiple stages of the ammonia recovery tower (5). At this time, the steam injected into the ammonia recovery tower (5) can heat the interior of the ammonia recovery tower (5) to maintain an appropriate recovery temperature of 80°C or more and 120°C or less.

[0053] The steam injected into the lowest stage among the multiple stages of the ammonia recovery tower (5) meets the ammonium sulfate wastewater injected into the highest stage among the multiple stages of the ammonia recovery tower (5), and the ammonia can be discharged through the outlet of the highest stage among the multiple stages of the ammonia recovery tower (5) in a state in which the ammonia is absorbed by the steam. At this time, the wastewater from which ammonia has been stripped can be discharged through the outlet of the lowest stage among the multiple stages of the ammonia recovery tower (5). The latent heat of the ammonia-stripped wastewater discharged from the ammonia recovery tower (5) can be 80°C or more and 100°C or less, and specifically, 80°C or more and 95°C or less. Therefore, the wastewater from which ammonia has been stripped can supply heat to the first heat exchanger, the second heat exchanger, and the water jacket described below. In addition, the ammonia-degassed wastewater may contain unreacted sodium (Na+), and thus may be used as a reactant for an additional sodium bicarbonate regeneration process of an integrated sodium bicarbonate regeneration and ammonia recovery system.

[0054] In one example, the integrated system for regeneration of ammonia and recovery of ammonia may further include a first heat exchanger (19). The first heat exchanger (19) is a device that receives wastewater from which ammonia is degassed and discharged from the ammonia recovery tower (5) and ammonium sulfate wastewater from which ammonium sulfate is discharged, and exchanges heat between the introduced wastewater from which ammonia is degassed and the ammonium sulfate wastewater, and is provided at a front end of the ammonia recovery tower (5), specifically, between the separator (18) and the ammonia recovery tower (5), so that the ammonium sulfate wastewater can be connected to the ammonia recovery tower (5) through one pipe through which the ammonium sulfate wastewater can move, and the ammonia-degassed wastewater can be connected to the ammonia recovery tower (5) through another pipe through which the ammonia-degassed wastewater can move. The above-described integrated system for regeneration and ammonia recovery further includes the first heat exchanger (19), so that the ammonium sulfate wastewater flowing into the ammonia recovery tower (5) can be preheated before flowing into the ammonia recovery tower (5), thereby improving the efficiency of the system and saving energy.

[0055] In another example, the integrated system for sodium bicarbonate regeneration and ammonia recovery may further include a second heat exchanger (20). The second heat exchanger (20) is a device that receives wastewater from which ammonia is degassed and discharged from the first heat exchanger (19) and ammonium sulfate wastewater from which ammonium sulfate is discharged, and exchanges heat between the introduced wastewater from which ammonia is degassed and the ammonium sulfate wastewater, and is provided in front of the separator (18), specifically, between the pH adjustment tank (17) and the separator (18), so that the ammonium sulfate wastewater can be connected to the separator (18) through one pipe through which the ammonium sulfate wastewater can move, and the wastewater from which ammonia is degassed can be connected to the first heat exchanger (19) through another pipe through which the ammonia is degassed. The above-described integrated system for regeneration and ammonia recovery further includes the second heat exchanger (20), so that the ammonium sulfate wastewater flowing into the ammonia recovery tower (5) can be preheated before flowing into the ammonia recovery tower (5), thereby improving the efficiency of the system and saving energy.

[0056] The above-described integrated system for regeneration of sodium bicarbonate and recovery of ammonia may further include a water jacket (21). The water jacket (21) is a passage that supplies heat of wastewater from which ammonia has been removed, discharged from the second heat exchanger (20), to the sodium bicarbonate dust dissolution tank (1), specifically, to the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10), and is provided to surround the periphery of the sodium bicarbonate dust dissolution tank (1), specifically, to the periphery of the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10), and the wastewater from which ammonia has been removed may be connected to the second heat exchanger (20) through a movable pipe. The above-described integrated system for regeneration and recovery of sodium bicarbonate further includes the water jacket (21), thereby maintaining the interior of the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10) at an appropriate temperature by the heat of the wastewater from which the ammonia has been removed, which moves around the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10). For example, the water jacket (21) may be a heating circulator that maintains the internal temperature of the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10) at 20°C or higher and 30°C or lower. In one embodiment, in the winter season when the temperature is high, the internal temperature of the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10) is maintained within the aforementioned temperature range, so the water jacket (21) may not be driven, and in the winter season when the temperature is low, the internal temperature of the sodium bicarbonate dust dissolution tank (1) and the sodium bicarbonate dust solution storage device (10) is below the lower limit of the aforementioned temperature range, so the water jacket (21) may be driven.

[0057] The above condenser (6) is a device into which ammonia recovered from the ammonia recovery tower (5), specifically ammonia absorbed into steam, is introduced and condenses the ammonia absorbed into the introduced steam to form ammonia water. At least one condenser (6) is provided at the rear end of the ammonia recovery tower (5) and is connected to the ammonia recovery tower (5) through a pipe. Through this, the ammonia absorbed into the steam discharged from the recovery tower can be phase-changed into a liquid form. At this time, the condensation of the ammonia absorbed into the steam through the condenser (6) can be performed by a cooling medium supplied from a cooler (25) described later.

[0058] The ammonia water storage device (7) is a device that receives ammonia water formed in the condenser (6), stores the introduced ammonia water, and supplies the stored ammonia water to the ammonium bicarbonate production reactor (2), specifically, to the ammonium bicarbonate production reactor (2) via the ammonia water supply device (22). The ammonia water storage device (7) is provided at the rear end of the condenser (6) and is connected to the condenser (6), the ammonium bicarbonate production reactor (2), or the ammonia water supply device (22) through respective pipes. For example, the ammonia water stored in the ammonia water storage device (7) can be transported and supplied to the ammonium bicarbonate production reactor (2) via the ammonia water supply device (22) or directly without passing through the ammonia water supply device (22) when the ammonia concentration is 20% or more and 30% or less.

[0059] In one example, the ammonia water storage device (7) may further include being connected to the ammonia recovery tower (5) via a pipe. When the ammonia concentration of the ammonia water stored in the ammonia water storage device (7) is less than 20%, it is transported and supplied to the ammonia recovery tower (5), and the supplied ammonia water comes into contact with steam together with the ammonium sulfate wastewater flowing into the ammonia recovery tower (5), so that the ammonia can be recovered.

[0060] In another example, the above-described integrated system for regeneration of sodium bicarbonate and ammonia recovery may further include an ammonia water supply device (22). The ammonia water supply device (22) is a device that stores ammonia water discharged from the ammonia water storage device (7) before it is supplied to the ammonium bicarbonate production reactor (2), further controls the concentration of ammonia in the stored ammonia water, and then supplies the stored ammonia water to the ammonium bicarbonate production reactor (2). The ammonia water supply device (22) is provided at the rear end of the ammonia water storage device (7) and may be connected to the ammonia water storage device (7) and the ammonia water supply device (22) through respective pipes.

[0061] For example, when the ammonia concentration in the ammonia water flowing into the ammonia water supply device (22) is 20% or more, the ammonia water is discharged from the ammonia water supply device (22) and supplied to the ammonium bicarbonate production reactor (2), and when the ammonia concentration in the ammonia water flowing into the ammonia water supply device (22) is less than 20%, the ammonia water produced in the ammonia water storage device (7) at a concentration of 20% or more is supplied to the ammonia water supply device (22) to adjust the ammonia concentration in the ammonia water in the ammonia water supply device (22) to 20% or more, and then the ammonia water is discharged from the ammonia water supply device (22) and supplied to the ammonium bicarbonate production reactor (2).

[0062] In another example, the above-described integrated regeneration and ammonia recovery system may further include an ammonia scrubber (23). The above ammonia scrubber (23) is a device capable of introducing ammonia discharged into the atmosphere from at least one of the ammonium bicarbonate production reactor (2), the ammonium bicarbonate storage device (13), the carbonation reactor (3), the first dehydrator (4), the dryer (14), the ammonia recovery tower (5), at least one condenser (6), and the ammonia water storage device (7), adding sulfuric acid (H2SO4) to the introduced ammonia to form ammonium sulfate, and supplying the formed ammonium sulfate to the ammonium sulfate wastewater, wherein each of the ammonium bicarbonate production reactor (2), the ammonium bicarbonate storage device (13), the carbonation reactor (3), the first dehydrator (4), the dryer (14), the ammonia recovery tower (5), at least one condenser (6), and the ammonia water storage device (7) is connected to the ammonia scrubber (23) through one pipe. Each of which is connected to one or more pipes, and can be connected to the ammonium sulfate wastewater storage device (16) through another pipe.

[0063] Ammonium sulfate formed in the ammonia scrubber (23) is supplied to the ammonia recovery tower (5) together with the ammonium sulfate wastewater, thereby enabling additional recovery of ammonia. By recovering ammonia that is discharged into the atmosphere in this way, not only can costs be reduced and reaction efficiency improved, but energy can also be saved.

[0064] In another example, the integrated system for bicarbonate regeneration and ammonia recovery may further include a gas holder (24). The gas holder (24) is a device that can recover and store gas discharged from at least one of the ammonium bicarbonate production reactor (2) and the carbonation reactor (3), and supply the stored gas to the flue gas containing carbon dioxide or the ammonia scrubber (23). The gas holder (24) may be provided between at least one of the ammonium bicarbonate production reactor (2) and the carbonation reactor (3), the flue gas pretreatment device (11), and the ammonia scrubber (23), and may be connected to each other through respective pipes. At this time, the gas supplied as the flue gas containing carbon dioxide may be supplied through a pipe connecting a pipe arranged on the outlet side of the flue gas pretreatment device (11) and the gas holder (24).

[0065] For example, when the concentration of carbon dioxide in the gas stored in the gas holder (24) is 10% or more, the gas may be supplied as flue gas containing carbon dioxide, and when the concentration of carbon dioxide in the gas stored in the gas holder (24) is less than 10%, the gas may be supplied to the ammonia scrubber (23). The gas supplied as flue gas containing carbon dioxide may be reused as carbon dioxide for producing an ammonium bicarbonate solution, and the gas supplied to the ammonia scrubber (23) may be supplied to the ammonia recovery tower (5) together with ammonium sulfate wastewater, thereby further recovering ammonia. Through this, carbon dioxide in the discharged gas may be reused for recapture and carbonation reactions, which may reduce costs and improve reaction efficiency, as well as reduce environmental pollution and save energy.

[0066] In another example, the above-described integrated system for sodium bicarbonate regeneration and ammonia recovery may further include a cooler (25). The cooler (25) is a device that supplies a cooling medium to one or more of the ammonium bicarbonate production reactor (2), the carbonation reactor (3), and the one or more condensers (6), and may be connected to one or more of the ammonium bicarbonate production reactor (2), the carbonation reactor (3), and the one or more condensers (6) through respective supply pipes and discharge pipes. At this time, cooling water having a temperature of 10°C or more and 15°C or less may be used as the cooling medium.

[0067] For example, when the cooler (25) supplies a cooling medium to the ammonium bicarbonate production reactor (2) through the supply pipe connected to the ammonium bicarbonate production reactor (2), the heat generated in the ammonium bicarbonate production reactor (2) can be cooled, the degree of dissociation of carbon dioxide can be increased, and the reaction rate can be increased. In addition, the cooling water that has passed through the ammonium bicarbonate production reactor (2) can be discharged through the discharge pipe connecting the ammonium bicarbonate production reactor (2) and the cooler (25) and re-introduced into the cooler (25).

[0068] In addition, when the cooler (25) supplies a cooling medium to the carbonation reactor (3) through the supply pipe connected to the carbonation reactor (3), it may be possible to cool the heat generated in the carbonation reactor (3), increase the degree of dissociation of carbon dioxide to increase the reaction rate, and lower the solubility of the sodium bicarbonate included in the regenerated sodium bicarbonate solution produced in the carbonation reactor (3) to precipitate it as a solid. The solubility of the sodium bicarbonate lowered by the cooling medium may be 80 g / L or more and 88 g / L or less at 10°C or more and 15°C or less. In addition, the cooling water that has passed through the carbonation reactor (3) may be discharged through the discharge pipe connecting the carbonation reactor (3) and the cooler (25) and re-introduced into the cooler (25).

[0069] In addition, when the cooler (25) supplies a cooling medium to one or more of the condensers (6) through the supply pipes each connected to one or more of the condensers (6), the ammonia introduced into one or more of the condensers (6) can be cooled and condensed. In addition, the cooling water that has passed through the one or more of the condensers (6) can be discharged through the discharge pipes each connecting one or more of the condensers (6) and the cooler (25) and be reintroduced into the cooler (25).

[0070] In this way, the reaction efficiency can be further improved by adjusting the temperature of each process using a cooler (25).

[0071] The present application also relates to an integrated method for regeneration of sodium bicarbonate and ammonia recovery. The integrated method for regeneration of sodium bicarbonate and ammonia recovery relates to an integrated method for regeneration of sodium bicarbonate and ammonia recovery using the integrated system for regeneration of sodium bicarbonate and ammonia recovery described above. Since the specific details of the integrated method for regeneration of sodium bicarbonate and ammonia recovery described below can be equally applied to the integrated system for regeneration of sodium bicarbonate and ammonia recovery described above, these details will be omitted.

[0072] The above integrated method for regenerating sodium bicarbonate and recovering ammonia includes a step of dissolving sodium bicarbonate dust, a step of producing ammonium bicarbonate, a carbonation reaction step, a first dehydration step, a step of recovering ammonia, a condensation step, and a step of storing ammonia water. According to the integrated method for regenerating sodium bicarbonate and recovering ammonia of the present application, it is possible to recover ammonia from ammonium sulfate wastewater generated during regenerating sodium bicarbonate and reuse it as ammonia water, thereby reducing the cost of purchasing ammonia water required for process operation, and generating additional operating profits through commercialization of the generated ammonia water.

[0073] The above-mentioned sodium bicarbonate dust dissolution step uses sodium bicarbonate (NaHCO3 (solid)), a desulfurizing agent, from the exhaust gas generated during the sintering process of a steel mill to remove sulfur oxides (SO). X ) is supplied to a sodium bicarbonate dust dissolution tank, which is a desulfurization waste generated when removing sodium bicarbonate dust, and the sodium bicarbonate dust supplied to the sodium bicarbonate dust dissolution tank is manufactured into a sodium bicarbonate dust solution. This is performed by dissolving the sodium bicarbonate dust supplied to the sodium bicarbonate dust dissolution tank in a solvent. Since a specific description of the sodium bicarbonate dust dissolution step is the same as that described in the sodium bicarbonate dust dissolution tank, it will be omitted.

[0074] In one example, the integrated method for regeneration and recovery of ammonia from the sodium bicarbonate may further include a storage step for the sodium bicarbonate dust. The storage step for the sodium bicarbonate dust is a step in which the sodium bicarbonate dust for supply to the sodium bicarbonate dust dissolution tank is stored in a storage device for the sodium bicarbonate dust. A detailed description of the storage step for the sodium bicarbonate dust is the same as that described for the storage device for the sodium bicarbonate dust, and thus will be omitted.

[0075] In another example, the integrated method for regenerating and recovering ammonia from the sodium bicarbonate may further include a second dehydration step. The second dehydration step is a step in which the sodium bicarbonate dust solution produced in the sodium bicarbonate dust dissolution step is introduced into a second dehydrator, and the introduced sodium bicarbonate dust solution is dehydrated to separate it into a sodium bicarbonate dust solution (Na2SO4(aq.)) from which insoluble matter and insoluble matter have been removed. A detailed description of the second dehydration step is the same as that described for the second dehydrator, and therefore will be omitted.

[0076] In another example, the integrated method for regenerating and recovering ammonia from the sodium bicarbonate may further include a step of storing a sodium bicarbonate solution. The step of storing a sodium bicarbonate solution is a step in which the sodium bicarbonate solution produced in the sodium bicarbonate solution dissolution step, specifically, the sodium bicarbonate solution from which insoluble matter has been removed through the second dehydration step, is introduced into a sodium bicarbonate solution storage device, and the introduced sodium bicarbonate solution is stored. A specific description of the sodium bicarbonate solution storage step is the same as that described for the sodium bicarbonate solution storage device, and thus will be omitted.

[0077] The above ammonium bicarbonate manufacturing step is a step of manufacturing an ammonium bicarbonate solution (NH4HCO3(aq.)) for manufacturing a regenerated sodium bicarbonate solution by reacting with the above sodium bicarbonate dust solution, and the ammonium bicarbonate solution is manufactured by reacting carbon dioxide (CO2(gas)) and ammonia water (NH4OH(liquid)) in an ammonium bicarbonate manufacturing reactor. A specific description of the above ammonium bicarbonate manufacturing step is the same as that described in the ammonium bicarbonate manufacturing reactor, and thus will be omitted.

[0078] In one example, the integrated method for the regeneration of sodium bicarbonate and ammonia recovery may further include a flue gas pretreatment step. The flue gas pretreatment step removes dust, sulfur oxides (SO) from the flue gas present in the atmosphere in a flue gas pretreatment device. X), and nitrogen oxides (NOx) are removed to generate flue gas containing carbon dioxide, and the generated flue gas containing carbon dioxide is supplied to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor. A specific description of the flue gas pretreatment step is the same as that described in the flue gas pretreatment device, and therefore, will be omitted.

[0079] In another example, the integrated method for regenerating sodium bicarbonate and recovering ammonia may further include a carbon dioxide capture step. The carbon dioxide capture step is a step in which flue gas containing carbon dioxide is introduced into a carbon dioxide capture device, carbon dioxide is captured from the introduced flue gas containing carbon dioxide, and the captured carbon dioxide is supplied to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor. A specific description of the carbon dioxide capture step is the same as that described for the carbon dioxide capture device, and thus will be omitted.

[0080] In another example, the ammonium bicarbonate production step may further include a cooling step. The cooling step is a step for maintaining the internal temperature of the ammonium bicarbonate production reactor, and may be performed by providing a cooling device within the ammonium bicarbonate production reactor. A specific description of the cooling step in the ammonium bicarbonate production step is the same as that described for the cooling device of the ammonium bicarbonate production device, and therefore will be omitted.

[0081] The above-described integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include an ammonium bicarbonate storage step. The ammonium bicarbonate storage step is a step in which the ammonium bicarbonate solution produced in the ammonium bicarbonate production step is introduced into an ammonium bicarbonate storage device and the introduced ammonium bicarbonate solution is stored. A detailed description of the ammonium bicarbonate storage step is the same as that described for the ammonium bicarbonate storage device, and thus will be omitted.

[0082] In the above carbonation reaction step, the sodium bicarbonate dust solution and the ammonium bicarbonate solution are supplied to the carbonation reactor, and the supplied sodium bicarbonate dust solution and the ammonium bicarbonate solution are reacted to produce a regenerated sodium bicarbonate solution (2NaHCO3(solid)). + 2(NH4)2SO4(aq.)) is produced. The carbon dioxide may be flue gas containing carbon dioxide pretreated in the flue gas pretreatment device, or carbon dioxide captured in the carbon dioxide capture step. The sodium bicarbonate dust solution may be produced in the sodium bicarbonate dust dissolution step, removed from the insoluble matter in the second dehydration step, or stored in the sodium bicarbonate dust solution storage step. In addition, the ammonium bicarbonate solution may be produced in the ammonium bicarbonate production step or stored in the ammonium bicarbonate storage step. Since a specific description of the carbonation reaction step is the same as that described in the carbonation reactor, it will be omitted.

[0083] In one example, the carbonation reaction step may further include supplying carbon dioxide from the exhaust gas pretreatment device or the carbon dioxide capture device. A detailed description of the supply of carbon dioxide in the carbonation reaction step is the same as that described for the carbon dioxide capture device, and thus will be omitted.

[0084] In another example, the carbonation reaction step may further include a cooling step. The cooling step is a step for maintaining the internal temperature of the carbonation reactor using a cooling device. A detailed description of the cooling step in the carbonation reaction step is identical to that described for the cooling device of the carbonation reactor, and thus will be omitted.

[0085] The first dehydration step is a step in which the regenerated sodium bicarbonate solution produced in the carbonation reaction step is introduced into the first dehydrator, and the introduced regenerated sodium bicarbonate solution is dehydrated to separate it into regenerated sodium bicarbonate (NaHCO3 (solid)) and ammonium sulfate wastewater ((NH4)2SO4 (aq.)). Since a specific description of the first dehydration step is the same as that described for the first dehydrator, it will be omitted.

[0086] In one example, the integrated method for regenerating and recovering ammonia from the sodium bicarbonate may further include a drying step. The drying step is a step of drying the regenerated sodium bicarbonate dehydrated in the first dehydration step in a dryer. A detailed description of the drying step is the same as that described for the dryer, and thus will be omitted.

[0087] In another example, the integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include an ammonium sulfate wastewater pretreatment step. The ammonium sulfate wastewater pretreatment step is a step of removing impurities contained in the ammonium sulfate wastewater discharged from the first dehydrator using an ammonium sulfate wastewater pretreatment device. A specific description of the ammonium sulfate wastewater pretreatment step is the same as that described in the ammonium sulfate wastewater pretreatment device, and thus will be omitted.

[0088] In another example, the integrated method for sodium bicarbonate regeneration and ammonia recovery may further include an ammonium sulfate wastewater storage step. The ammonium sulfate wastewater storage step is a step in which the pretreated ammonium sulfate wastewater from the ammonium sulfate wastewater pretreatment step flows into an ammonium sulfate wastewater storage device and the introduced ammonium sulfate wastewater is stored. A specific description of the ammonium sulfate wastewater storage step is the same as that described for the ammonium sulfate wastewater storage device, and thus will be omitted.

[0089] In another example, the integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include a pH adjustment step. The pH adjustment step is a step in which the ammonium sulfate wastewater separated in the first dehydration step, the ammonium sulfate wastewater pretreated in the ammonium sulfate wastewater pretreatment step, or the ammonium sulfate wastewater stored in the ammonium sulfate wastewater storage device is introduced into a pH adjustment tank, the pH of the introduced ammonium sulfate wastewater is increased, and a solid content is formed in the ammonium sulfate wastewater. A specific description of the pH adjustment step is the same as that described in the pH adjustment tank, and thus will be omitted.

[0090] In another example, the integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include a separation step. The separation step is a step in which a separator is provided upstream of the first heat exchanger, the ammonium sulfate wastewater that has undergone the pH adjustment step flows into the separator, and the introduced ammonium sulfate wastewater is pressurized and filtered to separate the solids and the ammonium sulfate wastewater from which the solids have been removed. A detailed description of the separation step is the same as that described for the separator, and thus will be omitted.

[0091] The above ammonia recovery step is a step in which the ammonium sulfate wastewater separated in the first dehydration step, specifically, the ammonium sulfate wastewater whose pH has been adjusted in the pH adjustment step or the ammonium sulfate wastewater that has gone through the separation step, is introduced into an ammonia recovery tower, and ammonia is recovered from the introduced ammonium sulfate wastewater. A specific description of the above ammonia recovery step is the same as that described in the above ammonia recovery tower, and thus will be omitted.

[0092] In one example, the integrated method for sodium bicarbonate regeneration and ammonia recovery may further include a first heat exchange step. The first heat exchange step is a step in which wastewater from which ammonia has been degassed discharged from the ammonia recovery tower, ammonium sulfate wastewater separated in the first dehydration step, ammonium sulfate wastewater pretreated in the ammonium sulfate wastewater pretreatment step, ammonium sulfate wastewater stored in the ammonium sulfate wastewater storage device, ammonium sulfate wastewater whose pH has been adjusted in the pH adjustment step, or ammonium sulfate wastewater discharged from the separator is introduced into a first heat exchanger, and heat of the introduced ammonia-degassed wastewater and the ammonium sulfate wastewater is exchanged. A specific description of the first heat exchange step is the same as that described for the first heat exchanger, and thus will be omitted. At this time, the latent heat of the ammonia-degassed wastewater discharged from the ammonia recovery tower may be 80°C or more and 100°C or less, and specifically, may be 80°C or more and 95°C or less.

[0093] In another example, the integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include a second heat exchange step. The second heat exchange step is a step in which a second heat exchanger is provided in front of the separator, and the ammonia-degassed wastewater discharged from the first heat exchanger, the ammonium sulfate wastewater separated in the first dehydration step, the ammonium sulfate wastewater pretreated in the ammonium sulfate wastewater pretreatment step, the ammonium sulfate wastewater stored in the ammonium sulfate wastewater storage device, or the ammonium sulfate wastewater discharged from the pH adjustment tank are introduced into the second heat exchanger, and the heat of the introduced ammonia-degassed wastewater and the ammonium sulfate wastewater is exchanged. Since a specific description of the second heat exchanger is the same as that described for the second heat exchanger, it will be omitted.

[0094] The above-described integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include a heat supply step. The heat supply step is a step in which wastewater from which ammonia has been removed from the second heat exchanger is supplied to a water jacket surrounding the sodium bicarbonate dust dissolution tank, specifically, the sodium bicarbonate dust dissolution tank and the sodium bicarbonate dust solution storage device, and the inside of the sodium bicarbonate dust dissolution tank, specifically, the sodium bicarbonate dust dissolution tank and the sodium bicarbonate dust solution storage device, is maintained at an appropriate temperature by the heat of the supplied wastewater from which ammonia has been removed. A specific description of the heat supply step is the same as that described for the water jacket, and thus will be omitted.

[0095] The above condensation step is a step in which ammonia recovered in the above ammonia recovery step, specifically ammonia absorbed into steam, is introduced and the ammonia absorbed into the introduced steam is condensed into a condenser to form ammonia water. A specific description of the above condensation step is the same as that described for the condenser, and thus will be omitted.

[0096] The ammonia water storage step is a step in which the ammonia water formed in the condensation step is introduced into the ammonia water storage device, the introduced ammonia water is stored, and the stored ammonia water is supplied to the ammonium bicarbonate production reactor, specifically, to the ammonium bicarbonate production reactor via the ammonia water supply device. For example, the ammonia water stored in the ammonia water storage step can be supplied directly to the ammonium bicarbonate production reactor via the ammonia water supply device or without passing through the ammonia water supply device when the ammonia concentration is 20% or more and 30% or less. A specific description of the ammonia water storage step is the same as that described in the ammonia water storage device, and thus will be omitted.

[0097] In one example, the ammonia water storage step may further include supplying the stored ammonia water to the ammonia recovery tower. For example, if the ammonia concentration of the stored ammonia water in the ammonia water storage step is less than 20%, the ammonia water may be transported and supplied to the ammonia recovery tower, and the supplied ammonia water may come into contact with steam together with the ammonium sulfate wastewater flowing into the ammonia recovery tower, thereby recovering the ammonia.

[0098] In another example, the integrated method for regeneration of sodium bicarbonate and recovery of ammonia may further include an ammonia water supply step. The ammonia water supply step is a step of storing ammonia water in an ammonia water supply device before the ammonia water discharged from the ammonia water storage device is supplied to the ammonium bicarbonate production reactor, further controlling the concentration of ammonia in the stored ammonia water, and then supplying the stored ammonia water to the ammonium bicarbonate production reactor. A specific description of the ammonia water supply step is the same as that described for the ammonia water supply device, and therefore will be omitted.

[0099] In another example, the integrated method for sodium bicarbonate regeneration and ammonia recovery may further include an ammonia scrubbing step. The ammonia scrubbing step is a step in which ammonia discharged into the atmosphere from at least one of the ammonium bicarbonate production step, the ammonium bicarbonate storage step, the carbonation reaction step, the first dehydration step, the drying step, the ammonia recovery step, the condensation step, and the ammonia water storage step is introduced into an ammonia scrubber, sulfuric acid (H2SO4) is sprayed onto the introduced ammonia to form ammonium sulfate, and the formed ammonium sulfate is injected into the ammonium sulfate wastewater. A specific description of the ammonia scrubbing step is the same as that described for the ammonia scrubber, and thus will be omitted.

[0100] In another example, the integrated method for regenerating sodium bicarbonate and recovering ammonia may further include a gas holding step. The gas holding step is a step in which gas discharged from at least one of the ammonium bicarbonate production step and the carbonation reaction step is recovered and stored in a gas holder, and the stored gas can be supplied to the flue gas containing carbon dioxide or the ammonia scrubber. A detailed description of the gas holding step is the same as that described for the gas holder, and thus will be omitted.

[0101] For example, in the gas holding step, if the concentration of carbon dioxide in the gas stored in the gas holder is 10% or more, the gas may be supplied as the flue gas containing carbon dioxide, and if the concentration of carbon dioxide in the gas stored in the gas holder is less than 10%, the gas may be supplied to the ammonia scrubber. The gas supplied as the flue gas containing carbon dioxide may be reused as carbon dioxide for producing an ammonium bicarbonate solution, and the gas supplied to the ammonia scrubber may be supplied to an ammonia recovery tower together with ammonium sulfate wastewater, thereby further recovering ammonia. Through this, carbon dioxide in the discharged gas may be reused for recapture and carbonation reactions, which may not only reduce costs and improve reaction efficiency, but also reduce environmental pollution and save energy.

[0102] In another example, the integrated method for regeneration and recovery of ammonia from the bicarbonate can further include a cooling step. The cooling step is a step of supplying a cooling medium from a cooler to at least one of the ammonium bicarbonate production reactor, the carbonation reactor, and one or more condensers. A detailed description of the cooling step is the same as that described for the cooler, and thus will be omitted.

[0103] <Explanation of symbols>

[0104] 1: Sodium bicarbonate powder dissolution tank

[0105] 2: Ammonium bicarbonate production reactor

[0106] 3: Carbonation reactor

[0107] 4: First dehydrator

[0108] 5: Ammonia recovery tower

[0109] 6: Condenser

[0110] 7: Ammonia water storage device

[0111] 8: Medium-sized dust storage device

[0112] 9: Second dehydrator

[0113] 10: Storage device for bicarbonate solution

[0114] 11: Exhaust gas pretreatment device

[0115] 12: Carbon dioxide capture device

[0116] 13: Ammonium bicarbonate storage device

[0117] 14: Dryer

[0118] 15: Ammonium sulfate wastewater pretreatment device

[0119] 16: Ammonium sulfate wastewater storage device

[0120] 17: pH adjustment tank

[0121] 18: Separator

[0122] 19: First heat exchanger

[0123] 20: Second heat exchanger

[0124] 21: Water jacket

[0125] 22: Ammonia water supply device

[0126] 23: Ammonia scrubber

[0127] 24: Gas holder

[0128] 25: Cooler

Claims

1. A sodium bicarbonate powder dissolution tank that dissolves sodium bicarbonate powder to produce a sodium bicarbonate powder solution; Ammonium bicarbonate production reactor that produces an ammonium bicarbonate solution by reacting carbon dioxide and ammonia water; A carbonation reactor for producing a regenerated sodium bicarbonate solution by reacting a sodium bicarbonate dust solution and an ammonium bicarbonate solution; A first dehydrator for dehydrating the regenerated sodium bicarbonate solution produced in the carbonation reactor and separating it into regenerated sodium bicarbonate and ammonium sulfate wastewater; Ammonia recovery tower for recovering ammonia from ammonium sulfate wastewater; One or more condensers for condensing ammonia recovered from the ammonia recovery tower to form ammonia water; and An integrated system for sodium bicarbonate regeneration and ammonia recovery, comprising an ammonia water storage device capable of storing ammonia water and supplying the stored ammonia water to the ammonium bicarbonate production reactor.

2. In paragraph 1, An integrated system for sodium bicarbonate regeneration and ammonia recovery, further comprising an ammonia scrubber capable of introducing ammonia discharged into the atmosphere from at least one of the ammonium bicarbonate production reactor, the carbonation reactor, the first dehydrator, the ammonia recovery tower, at least one condenser, and the ammonia water storage device, adding sulfuric acid to the introduced ammonia to form ammonium sulfate, and supplying the formed ammonium sulfate to the ammonium sulfate wastewater.

3. In paragraph 2, It further includes a flue gas pretreatment device capable of pretreating flue gas and supplying flue gas containing carbon dioxide to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor. An integrated system for bicarbonate regeneration and ammonia recovery, further comprising a gas holder capable of recovering and storing gas discharged from at least one of the above ammonium bicarbonate production reactor and the above carbonation reactor, and supplying the stored gas to the flue gas containing carbon dioxide or the above ammonia scrubber.

4. In paragraph 3, An integrated system for regeneration of carbon dioxide and recovery of ammonia, which supplies the gas as flue gas containing carbon dioxide when the concentration of carbon dioxide in the gas stored in the gas holder is 10% or more, and supplies the gas to the ammonia scrubber when the concentration of carbon dioxide in the gas stored in the gas holder is less than 10%.

5. In paragraph 1, An integrated system for regenerating and recovering ammonia, further comprising a cooler for supplying a cooling medium to at least one of the above-described ammonium bicarbonate production reactor, the above-described carbonation reactor, and the above-described one or more condensers.

6. In paragraph 1, An integrated system for regeneration and ammonia recovery, further comprising a first heat exchanger provided at the front end of the ammonia recovery tower, in which heat of ammonia-degassed wastewater discharged from the ammonia recovery tower is exchanged with ammonium sulfate wastewater.

7. In paragraph 6, An integrated system for regeneration of sodium bicarbonate and recovery of ammonia, wherein the latent heat of the ammonia-degassed wastewater is 80°C or higher and 100°C or lower.

8. In paragraph 6, It further includes a separator provided at the front end of the first heat exchanger to separate solids from ammonium sulfate wastewater, An integrated system for bicarbonate regeneration and ammonia recovery, further comprising a second heat exchanger provided in the front end of the separator, in which heat of the ammonia-degassed wastewater discharged from the first heat exchanger is exchanged with the ammonium sulfate wastewater.

9. In paragraph 8, An integrated system for regeneration and recovery of ammonia from ammonia, further comprising a water jacket that surrounds the periphery of the above-mentioned ammonia dust dissolution tank and is supplied with heat from wastewater from which ammonia has been degassed and discharged from the second heat exchanger.

10. A sodium bicarbonate dust dissolution step for producing a sodium bicarbonate dust solution by dissolving sodium bicarbonate dust in a sodium bicarbonate dust dissolution tank; An ammonium bicarbonate production step of producing an ammonium bicarbonate solution by reacting carbon dioxide and ammonia water in an ammonium bicarbonate production reactor; A carbonation reaction step for producing a regenerated sodium bicarbonate solution by reacting a sodium bicarbonate dust solution and an ammonium bicarbonate solution in a carbonation reactor; A first dehydration step of dehydrating the regenerated sodium bicarbonate solution produced in the above carbonation reaction step in a first dehydrator to separate it into regenerated sodium bicarbonate and ammonium sulfate wastewater; An ammonia recovery step for recovering ammonia from ammonium sulfate wastewater using an ammonia recovery tower; A condensation step of condensing the ammonia recovered in the above ammonia recovery step in one or more condensers to form ammonia water; and An integrated method for sodium bicarbonate regeneration and ammonia recovery, comprising an ammonia water storage step capable of storing ammonia water in an ammonia water storage device and supplying the stored ammonia water to the ammonium bicarbonate production reactor.

11. In paragraph 10, An integrated method for sodium bicarbonate regeneration and ammonia recovery, further comprising an ammonia scrubbing step in which ammonia discharged into the atmosphere in at least one of the ammonium bicarbonate production step, the carbonation reaction step, the first dehydration step, the ammonia recovery step, the condensation step, and the ammonia water storage step is introduced into an ammonia scrubber, sulfuric acid is added to the introduced ammonia to form ammonium sulfate, and the formed ammonium sulfate is supplied to the ammonium sulfate wastewater.

12. In paragraph 11, It further includes a pretreatment step in which the flue gas is pretreated in a flue gas pretreatment device and the flue gas containing carbon dioxide is supplied to the ammonium bicarbonate production reactor, or to both the ammonium bicarbonate production reactor and the carbonation reactor. An integrated method for regenerating and recovering ammonia, further comprising a gas holding step for recovering gas discharged from at least one of the above ammonium bicarbonate production step and the above carbonation reaction step and storing the recovered gas in a gas holder, and supplying the stored gas to the flue gas containing carbon dioxide or the ammonia scrubber.

13. In paragraph 12, An integrated method for regeneration of sodium bicarbonate and recovery of ammonia, wherein when the concentration of carbon dioxide in the gas stored in the gas holder is 10% or more, the gas is supplied as flue gas containing carbon dioxide, and when the concentration of carbon dioxide in the gas stored in the gas holder is less than 10%, the gas is supplied to the ammonia scrubber.

14. In paragraph 10, An integrated method for regenerating sodium bicarbonate and recovering ammonia, further comprising a cooling step of supplying a cooling medium to at least one of the ammonium bicarbonate production reactor, the carbonation reactor and the at least one condenser in a cooler.

15. In paragraph 10, An integrated method for regeneration of sodium bicarbonate and recovery of ammonia, further comprising a first heat exchange step in which a first heat exchanger is provided at the front end of the ammonia recovery tower, and heat is exchanged between wastewater from which ammonia is degassed and ammonium sulfate wastewater discharged from the ammonia recovery tower.

16. In paragraph 15, An integrated method for regenerating sodium bicarbonate and recovering ammonia, wherein the latent heat of the ammonia-degassed wastewater is 80°C or higher and 100°C or lower.

17. In paragraph 15, A separator is provided in the front end of the first heat exchanger, and further includes a separation step for separating solids from ammonium sulfate wastewater. An integrated method for regeneration of sodium bicarbonate and recovery of ammonia, further comprising a second heat exchange step in which a second heat exchanger is provided in the front end of the separator, and heat of the wastewater from which ammonia is degassed and the ammonium sulfate wastewater discharged in the first heat exchange step is exchanged.

18. In paragraph 17, An integrated method for regenerating and recovering ammonia, further comprising a heat supply step in which a water jacket is provided to surround the periphery of the above-mentioned mixed carbon dioxide dissolution tank, and heat from the wastewater from which ammonia has been removed and discharged in the second heat exchange step is supplied to the water jacket.

Images