Recovery system for reactive nitrogen in combusion process and power generation facility

Abstract

The present invention comprises: a combustion means 1 that involves the discharge of NOX; an oxidation means 2 that oxidizes the NOX discharged by the combustion means 1 to obtain water-soluble N2O5; a dissolution / oxidation means 3 that dissolves the N2O5, which was obtained as a result of the oxidization, to form NO3 -; a first conversion means 4 that converts the NO3 -, which was obtained as a result of dissolution, to a nitrate and recovering the same; a reduction means 5 that reduces the NO3 -, which was obtained as a result of dissolution, to form NH4 + and that converts the NH4 +, which was obtained as a result of reduction, to NH3 or an ammonium salt and recovering the same; and a NH3 conversion means 6.

Description

Reactive nitrogen recovery systems in combustion processes, power generation equipment

[0001] The present invention relates to a method for producing insoluble NOx emitted in a combustion process, the method comprising the steps of: Ｘ The present invention relates to a recovery system for recovering nitrogen as valuable reactive nitrogen, and a power generation facility.

[0002] Nitrogen is essential for life and ammonia (NH ３ ) and is used as a reactive nitrogen, for example, in fertilizers. Its use as a fuel for combustion is also being investigated. ３ It is believed that using it as a fuel for combustion can meet the demand for a decarbonized society. Most of the reactive nitrogen emitted after use (nitrogen-containing gas and nitrogen-containing wastewater) is N ２ (nitrogen molecules) can be made harmless (for example, Patent Document 1).

[0003] NH ３ To obtain this, external energy is used to convert atmospheric N ２ and H produced from fossil fuels ２ (hydrogen molecules) are reacted with NOx contained in the combustion exhaust gas. Ｘ is the external energy and NH ３ Using N ２ It is decomposed into and rendered harmless (denitrified).

[0004] In this way, NH ３ Reactive nitrogen such as NH is currently used in various fields. ３ It is expected that the demand for carbon-free fuels such as fossil fuels will increase significantly. In this situation, there has been a demand for the development of a technology that can effectively utilize reactive nitrogen, which has been neutralized using energy, while significantly reducing the amount of energy used.

[0005] JP 2017-189719 A

[0006] The present invention has been made in view of the above circumstances, and provides a method for treating insoluble NOx, which is emitted in a combustion process and mainly contains NOx that is insoluble in water. ＸThe present invention aims to provide a system for recovering reactive nitrogen in a combustion process, which can significantly reduce energy consumption and effectively utilize (reuse) the reactive nitrogen by recovering reactive nitrogen as reactive nitrogen.

[0007] The present invention has been made in view of the above circumstances, and provides a method for producing insoluble NOx, which is emitted in a combustion process and mainly contains NOx that is insoluble in water. Ｘ The present invention aims to provide a power generation facility equipped with an exhaust gas treatment means that can recover reactive nitrogen as reactive nitrogen, thereby significantly reducing energy consumption and effectively utilizing (reusing) the reactive nitrogen.

[0008] In order to achieve the above object, the reactive nitrogen recovery system in the combustion process of the present invention according to claim 1 is a system for recovering insoluble NO mainly containing NO that is insoluble in water. Ｘ and (arranged in an exhaust system of the combustion means) emitting insoluble NOx mainly containing NOx insoluble in water, which is emitted by the combustion means. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － and a first conversion means for converting the above-mentioned nitrate into nitrate and recovering it.

[0009] In the present invention according to claim 1, insoluble NOx mainly containing NOx insoluble in water is extracted from the exhaust gas of the combustion means. Ｘ Therefore, insoluble NO, which mainly contains water-insoluble NO, can be recovered by obtaining nitrates from the Ｘ For example, the ratio of two-stage combustion (two-stage combustion rate) can be increased or the air ratio can be decreased to reduce the amount of insoluble NOx mainly containing NOx that is insoluble in water. Ｘ Therefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. ＸThis allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0010] "Insoluble NO, mainly containing NO that is insoluble in water Ｘ The "water" in "water-soluble nitrogen oxides" does not only mean "pure water" but also includes "aqueous solutions, slurries, etc."

[0011] In order to achieve the above object, the reactive nitrogen recovery system for a combustion process of the present invention according to claim 2 is a system for recovering insoluble NOx mainly containing NOx that is insoluble in water. Ｘ and a combustion means that discharges insoluble NOx, mainly containing NOx that is insoluble in water, discharged by the combustion means. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － NH ３ or ammonium salts, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

[0012] In the present invention according to claim 2, insoluble NOx mainly containing NOx insoluble in water is extracted from the exhaust gas of the combustion means. Ｘ From NH ３ or ammonium salts, or NH ３ Therefore, the insoluble NOx, which mainly contains NOx that is insoluble in water, can be recovered by obtaining and recovering the ammonium salt. Ｘ For example, the ratio of two-stage combustion (two-stage combustion rate) can be increased or the air ratio can be decreased to reduce the amount of insoluble NOx mainly containing NOx that is insoluble in water. ＸTherefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. Ｘ This allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0013] In order to achieve the above object, the reactive nitrogen recovery system for a combustion process of the present invention according to claim 3 is a system for recovering insoluble NOx mainly containing NOx that is insoluble in water. Ｘ and a combustion means that discharges insoluble NOx, mainly containing NOx that is insoluble in water, discharged by the combustion means. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － a first conversion means for converting NO into nitrate and recovering it; and a second conversion means for recovering NO dissolved or dissolved and oxidized by the dissolution and oxidation means. ３ － NH ３ or ammonium salts, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

[0014] In the present invention according to claim 3, insoluble NOx mainly containing NOx insoluble in water is extracted from the exhaust gas of the combustion means. Ｘ From nitrate, NH ３ or ammonium salts, or NH ３ Therefore, the insoluble NOx, which mainly contains NOx that is insoluble in water, can be recovered by obtaining and recovering the ammonium salt. Ｘ For example, the ratio of two-stage combustion (two-stage combustion rate) can be increased or the air ratio can be decreased to reduce the amount of insoluble NOx mainly containing NOx that is insoluble in water. ＸTherefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. Ｘ This allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0015] In the reactive nitrogen recovery system for a combustion process according to claims 1 to 3, the insoluble NO mainly containing NO that is insoluble in water is Ｘ is composed mainly of NO and does not contain other NO Ｘ It is considered to be a whole substance containing trace amounts of ingredients.

[0016] The water-soluble nitrogen oxides in the reactive nitrogen recovery system in the combustion process are NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ It is preferable that the oxidation means includes a means for injecting ozone.

[0017] Therefore, in the system for recovering reactive nitrogen in a combustion process of the present invention, insoluble NOx, which mainly contains NOx that is insoluble in water, emitted in the combustion process is recovered. Ｘ By recovering the reactive nitrogen, it becomes possible to significantly reduce energy consumption and effectively utilize (reuse) the reactive nitrogen.

[0018] The reactive nitrogen recovery system for a combustion process according to the present invention, as set forth in claim 4, is the reactive nitrogen recovery system for a combustion process according to claim 2 or 3, wherein the second conversion means converts the NO dissolved or dissolved and oxidized by the dissolution / oxidation means into a reactive nitrogen. ３ － is reduced to NH ４ ＋ and reduced NH ４ ＋ NH ３or ammonium salts, or NH ３ and recovering the ammonium salt.

[0019] In the present invention according to claim 4, dissolved or dissolved and oxidized NO ３ － is reduced to NH ４ ＋ and reduced NH ４ ＋ NH ３ or ammonium salts, or NH ３ and converted to the ammonium salt.

[0020] The reactive nitrogen recovery system for a combustion process according to the present invention, according to claim 5, is the reactive nitrogen recovery system for a combustion process according to claim 2 or 3, wherein the NH converted by the second conversion means is ３ is used as fuel (all or part) for the combustion means.

[0021] In the present invention according to claim 5, insoluble NOx mainly containing NOx insoluble in water is extracted from the exhaust gas of the combustion means. Ｘ NH obtained from ３ The insoluble NOx that flows out, mainly containing NOx that is insoluble in water, can be used as fuel for combustion means (nitrogen recycling). Ｘ This can almost completely eliminate the need for energy to neutralize the waste.

[0022] Furthermore, the reactive nitrogen recovery system for a combustion process of the present invention according to claim 6 is characterized in that in the reactive nitrogen recovery system for a combustion process according to any one of claims 1 to 3, the combustion means obtains a high-pressure fluid by burning fuel.

[0023] In the present invention according to claim 6, a boiler for obtaining steam for driving a steam turbine and a combustor for obtaining combustion gas for driving a gas turbine can be applied as the combustion means.

[0024] Furthermore, the reactive nitrogen recovery system for a combustion process of the present invention according to claim 7 is characterized in that in the reactive nitrogen recovery system for a combustion process according to any one of claims 1 to 3, the combustion means is an engine that obtains power by burning fuel.

[0025] In the present invention according to claim 7, an internal combustion engine having a combustion chamber (such as a diesel engine for a large vehicle or ship) can be applied as the combustion means.

[0026] In order to achieve the above object, the power generation facility of the present invention according to claim 8 is a power generation facility that generates insoluble NOx mainly containing NOx that is insoluble in water. Ｘ an expansion turbine that expands a high-pressure fluid obtained by combustion in the combustion means to obtain power for generating electricity; and exhaust gas treatment means that treats the exhaust gas after the power for generating electricity has been obtained, and the exhaust gas treatment means is configured to treat insoluble NOx in the exhaust gas, which mainly contains NOx that is insoluble in water. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － and a first conversion means for converting the nitrate into nitrate and recovering the nitrate.

[0027] In the present invention according to claim 8, insoluble NOx mainly containing NOx insoluble in water is extracted from exhaust gas (boiler exhaust gas, gas turbine exhaust gas) after generating power. Ｘ Therefore, insoluble NO, which mainly contains water-insoluble NO, can be recovered by obtaining nitrates from the Ｘ For example, by increasing the ratio of two-stage combustion or decreasing the air ratio, the insoluble NOx mixture containing mainly water-insoluble NOx can be reduced. Ｘ Therefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. ＸThis allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0028] In order to achieve the above object, the power generation facility of the present invention according to claim 9 is characterized in that it is a power generation facility that generates insoluble NOx mainly containing NOx that is insoluble in water. Ｘ an expansion turbine that expands a high-pressure fluid obtained by combustion in the combustion means to obtain power for generating electricity; and exhaust gas treatment means that treats the exhaust gas after the power for generating electricity has been obtained, and the exhaust gas treatment means is configured to treat insoluble NOx in the exhaust gas, which mainly contains NOx that is insoluble in water. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － NH ３ or ammonium salts, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

[0029] In the present invention according to claim 9, insoluble NOx mainly containing NOx insoluble in water is extracted from exhaust gas (boiler exhaust gas, gas turbine exhaust gas) after generating power. Ｘ From NH ３ or ammonium salts, or NH ３ Therefore, the insoluble NOx, which mainly contains NOx that is insoluble in water, can be recovered by obtaining and recovering the ammonium salt. Ｘ For example, the ratio of two-stage combustion (two-stage combustion rate) can be increased or the air ratio can be decreased to reduce the amount of insoluble NOx mainly containing NOx that is insoluble in water. Ｘ Therefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. ＸThis allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0030] In order to achieve the above object, the power generation facility of the present invention according to claim 10 is characterized in that it is a power generation facility that uses insoluble NOx mainly containing NOx that is insoluble in water. Ｘ an expansion turbine that expands a high-pressure fluid obtained by combustion in the combustion means to obtain power for generating electricity; and exhaust gas treatment means that treats the exhaust gas after the power for generating electricity has been obtained, and the exhaust gas treatment means is configured to treat insoluble NOx in the exhaust gas, which mainly contains NOx that is insoluble in water. Ｘ to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO. ３ － and a dissolving / oxidizing means for dissolving or oxidizing NO dissolved or dissolved and oxidized by the dissolving / oxidizing means. ３ － a first conversion means for converting NO into nitrate and recovering the nitrate; and a second conversion means for recovering the NO dissolved or dissolved and oxidized by the dissolution and oxidation means. ３ － NH ３ or ammonium salts, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

[0031] In the present invention according to claim 10, insoluble NOx mainly containing NOx insoluble in water is extracted from exhaust gas (boiler exhaust gas, gas turbine exhaust gas) after generating power. Ｘ From nitrate, NH ３ or ammonium salts, or NH ３ Therefore, the insoluble NOx, which mainly contains NOx that is insoluble in water, can be recovered by obtaining and recovering the ammonium salt. Ｘ For example, the ratio of two-stage combustion (two-stage combustion rate) can be increased or the air ratio can be decreased to reduce the amount of insoluble NOx mainly containing NOx that is insoluble in water. ＸTherefore, when coal is used as fuel, for example, combustion can be performed to reduce unburned carbon, and the quality of ash can be improved. Ｘ This allows combustion that emits NH3, which reduces restrictions on combustion and reduces the amount of NH4 in the exhaust gas. ３ Since there is no need to add denitration gas, corrosion of pipes can be suppressed.

[0032] In the power generation equipment according to claims 8 to 10, the insoluble NO mainly containing NO that is insoluble in water is Ｘ is composed mainly of NO and does not contain other NO Ｘ It is considered to be a whole substance containing trace amounts of ingredients.

[0033] Water-soluble nitrogen oxides in power generation facilities are NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ It is preferable that the oxidation means includes a means for injecting ozone.

[0034] Therefore, in the power generation equipment of the present invention, insoluble NOx, which is mainly composed of NOx insoluble in water, emitted in the combustion process, is Ｘ By recovering reactive nitrogen, it becomes possible to provide a power generation facility equipped with an exhaust gas treatment means that can effectively utilize (reuse) reactive nitrogen while significantly reducing energy consumption.

[0035] The power generating facility of the present invention according to claim 11 is the power generating facility according to claim 9 or claim 10, wherein the second conversion means converts NO dissolved or dissolved and oxidized by the dissolution / oxidation means into NO ３ － is reduced to NH ４ ＋ and reduced NH ４ ＋ NH ３ or ammonium salts, or NH ３and recovering the ammonium salt.

[0036] In the present invention according to claim 11, dissolved or dissolved and oxidized NO ３ － is reduced to NH ４ ＋ and reduced NH ４ ＋ NH ３ or ammonium salts, or NH ３ and converted to the ammonium salt.

[0037] The power generation facility of the present invention according to claim 12 is the power generation facility according to claim 9 or 10, wherein the combustion means is configured to combust a part or all of the fuel with NH ３ The combustion means is configured to include NH recovered by the second conversion means. ３ is supplied.

[0038] In the present invention according to claim 12, insoluble NOx mainly containing NOx insoluble in water is extracted from the exhaust gas of the expansion turbine. Ｘ NH obtained from ３ The insoluble NOx that flows out, mainly containing NOx that is insoluble in water, can be used as fuel for combustion means (nitrogen recycling). Ｘ This can almost completely eliminate the need for waste, reducing the energy required to neutralize it.

[0039] The reactive nitrogen recovery system for a combustion process of the present invention is a system for recovering insoluble NOx, mainly containing NOx that is insoluble in water, emitted in a combustion process. Ｘ By recovering the reactive nitrogen, it becomes possible to significantly reduce energy consumption and effectively utilize (reuse) the reactive nitrogen.

[0040] The power generation equipment of the present invention also has a function of reducing insoluble NOx, which is emitted in the combustion process and mainly contains NOx, which is insoluble in water. Ｘ By recovering reactive nitrogen, it becomes possible to provide a power generation facility equipped with an exhaust gas treatment means that can effectively utilize (reuse) reactive nitrogen while significantly reducing energy consumption.

[0041] 1 is a block diagram of a reactive nitrogen recovery system in a combustion process according to an embodiment of the present invention. Ｘ 10 is a graph showing the relationship between the concentration and the proportion of unburned carbon.

[0042] FIG. 1 shows a block diagram for explaining an outline of the entire system for recovering reactive nitrogen in a combustion process according to one embodiment of the present invention.

[0043] As shown in the figure, the reactive nitrogen recovery system in the combustion process of the present invention recovers insoluble NO, which mainly contains NO that is insoluble in water. Ｘ The combustion means 1 is equipped with a combustion unit 1 that emits coal and NH ３ Nitrogen-containing fuels such as the above are used, and insoluble NOx, which mainly contains NOx that is insoluble in water, is used. Ｘ (Mainly fuel No. Ｘ Even if fuels that do not contain nitrogen, such as natural gas or hydrogen, are used, the nitrogen contained in the combustion air ２ Insoluble NO mainly containing NO that is insoluble in water Ｘ (Thermal No. Ｘ ) is emitted.

[0044] Insoluble NOx in the exhaust gas from the combustion means 1, mainly containing NOx insoluble in water Ｘ (NO emitted from the combustion means Ｘ ) is converted into water-soluble nitrogen oxides (NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ For example, mainly N ２ O ５ Nitrogen oxides including: N ２ O ５ ) is oxidized to

[0045] As the oxidation means 2, a means configured to supply oxygen is applied. Alternatively, a means for injecting ozone can be applied. Furthermore, as the oxidation means, the combustion means 1 and the oxidation means 2 can be omitted, and water-soluble nitrogen oxides (NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ For example, mainly N ２ O ５ Nitrogen oxides including: N ２ O ５ In this case, the "combustion appliance" as the oxidation means corresponds to the "combustion means" and "oxidation means" described in claim 1.

[0046] Insoluble NO, mainly consisting of water-insoluble NO Ｘ is mainly N in oxidation means 2 ２ O ５ The water-soluble nitrogen oxides include ２ O ５ We will explain this as a representative example. ２ O ５ When the above method is applied, it is preferable to use a means for injecting ozone as the oxidation means 2.

[0047] Oxidized, N ２ O ５ is dissolved by the dissolving / oxidizing means 3 and NO ３ － In other words, N ２ O ５ If applies, N ２ O ５ Even if it is not oxidized, NO ３ － Therefore, the dissolution and oxidation means 3 is N ２ O ５ It is considered to be a means of dissolving only N ２ O ５ is dissolved and NO ３ －is converted to nitrate (for example, crystallized) by the first conversion means 4 and recovered. The recovered nitrate is used as agricultural fertilizer (water-insoluble NOx mainly containing NOx). Ｘ Reuse of nitrogen in the atmosphere: the nitrogen cycle).

[0048] The water-soluble nitrogen oxides include NO ２ , N ２ O ３ , N ２ O ４ When the dissolution and oxidation means 3 is applied, NO ２ , N ２ O ３ , N ２ O ４ is dissolved and oxidized to NO ３ － That is, the dissolving / oxidizing means 3 dissolves or dissolves and oxidizes the water-soluble nitrogen oxides to form NO ３ － It has become a means to

[0049] In addition, the oxidation means 2 and the dissolving / oxidizing means 3 are omitted, and a "dissolving / oxidizing device" is separately provided, and NO Ｘ No ２ , N ２ O ３ , N ２ O ４ And at the same time, NO ２ , N ２ O ３ , N ２ O ４ No ３ － In this case, the "dissolving / oxidizing device" corresponds to the "oxidizing means" and "dissolving / oxidizing means" recited in claim 1.

[0050] On the other hand, the NO dissolved by the dissolving / oxidizing means 3 ３ － is reduced to NH by a reduction means 5 (second conversion means) that performs reduction by, for example, a biological reaction, an electrode reaction, a chemical reaction, or the like. ４ ＋ Then, the NH ４ ＋is converted to NH by stripping conversion means (second conversion means) 6, for example. ３ The recovered NH ３ is used as a fuel for the combustion means 1 (fuel for other combustion means), a reducing agent for external flue gas treatment (for denitration), etc. (insoluble NOx mainly containing NOx insoluble in water Ｘ Reuse of nitrogen in the atmosphere: the nitrogen cycle).

[0051] In addition, in the conversion means 6, NH ４ ＋ can also be converted to an ammonium salt. ３ and can be converted to the ammonium salt.

[0052] Recovered NH ３ as a fuel for the combustion means 1, the insoluble NOx that mainly contains NOx that is insoluble in water is reduced. Ｘ This can almost completely eliminate the need for detoxification, reduce the energy required for detoxification, and achieve the recycling of nitrogen.

[0053] In the reactive nitrogen recovery system for the combustion process having the above configuration, insoluble NOx mainly containing NOx insoluble in water is recovered from the exhaust gas of the combustion means 1. Ｘ From nitrate, NH ３ (ammonium salt) can be obtained and recovered (insoluble NO mainly containing water-insoluble NO Ｘ Reuse of nitrogen: nitrogen cycle). Insoluble NOx, mainly containing water-insoluble NOx, emitted in the combustion process. Ｘ By recovering reactive nitrogen, N ２ This makes it possible to effectively utilize (reuse) reactive nitrogen without detoxifying it, thereby significantly reducing energy consumption and enabling the recycling of reactive nitrogen.

[0054] The reactive nitrogen recovery system in the combustion process of the present invention omits the reduction means 5 and conversion means 6, and uses the NO dissolved or dissolved and oxidized by the dissolution / oxidation means 3. ３ －It is also possible to omit the first conversion means 4 and recover the dissolved or dissolved and oxidized NO by the dissolution and oxidation means 3. ３ － is converted to NH by reduction means 5 and conversion means 6. ３ It is also possible to simply convert the ammonium salt into the ammonium salt and recover it.

[0055] In addition, the NO dissolved or dissolved and oxidized by the dissolving / oxidizing means 3 ３ － NH ４ ＋ and the reduced NH ４ ＋ NH ３ It is made up of materials that have been converted into and recovered, but NO ３ － NH ３ (ammonium salt), the reduced NH ４ ＋ NH ３ However, the present invention is not limited to the configuration in which the image is converted into the image.

[0056] The above-mentioned combustion process corresponds to, for example, a process from a fuel supply system to an exhaust system in a boiler or combustor of a power generation facility (power generating equipment), or a process from a fuel supply system to an exhaust system in a diesel engine of a large vehicle or a ship, and by applying the reactive nitrogen recovery system in the combustion process of the present invention, insoluble NOx, which mainly contains NOx that is insoluble in water, can be recovered in the power generation facility or the diesel engine. Ｘ This allows for combustion that emits

[0057] An example of a power generation facility to which a system for recovering reactive nitrogen in a combustion process is applied will be described with reference to FIGS. 2 and 3. FIG.

[0058] Figure 2 shows a schematic diagram of the overall power generation facility to which the reactive nitrogen recovery system in the combustion process of the above configuration is applied, and Figure 3 shows the two-stage combustion rate and the insoluble NOx mainly containing NOx insoluble in water. Ｘ The relationship between the concentration and the unburned carbon fraction is shown.

[0059] As shown in Figure 2, the power generation facility (thermal power generation facility) 11 includes a boiler 12 that uses coal as fuel primarily to generate high-pressure steam, which is a high-temperature, high-pressure fluid, and the high-pressure steam generated in the boiler 12 is expanded and driven by a steam turbine 13, which is an expansion turbine, and power is generated by driving the steam turbine 13. The facility is also provided with exhaust gas treatment means 14 that treats exhaust gas from the boiler 12 (exhaust gas after generating power).

[0060] The exhaust gas treatment means 14 is provided with the system shown in Fig. 1. That is, insoluble NO in the exhaust gas, which mainly contains NO that is insoluble in water, Ｘ water-soluble nitrogen oxides (NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ For example, mainly N ２ O ５ Nitrogen oxides including: N ２ O ５ ) is provided, and the N oxidized by the oxidation means 2 is ２ O ５ Dissolve NO ３ － The NO dissolved in the dissolving / oxidizing means 3 is provided. ３ － into nitrates and recovering the nitrates as, for example, fertilizer.

[0061] The nitrogen oxides oxidized by the oxidation means 2 are N ２ O ５ In this case, the dissolution and oxidation means 3 is N ２ O ５ The nitrogen oxides oxidized by the oxidation means 2 are dissolved in N ２ O ５ If other than (NO ２ The dissolving / oxidizing means 3 dissolves and oxidizes nitrogen oxides, and the nitrogen oxides are dissolved and oxidized by the dissolving / oxidizing means 3 to produce NO ３ － It is said that.

[0062] Then, the NO dissolved by the dissolving / oxidizing means 3 ３ － is reduced to NH ４ ＋ (reduction means 5), and ４ ＋ NH ３ The apparatus is provided with a conversion means 6 that converts the ammonium salt into ammonium salt and recovers it. When the ammonium salt is recovered by the conversion means 6, the recovered ammonium salt is recovered as, for example, a fertilizer.

[0063] The boiler 12 is supplied with NH recovered by the conversion means 6 as part of the fuel. ３ When sulfur is contained in the fuel, the dissolving and oxidizing means 3 dissolves the SO ２ The exhaust gas treatment means 14 is appropriately equipped with a device for removing soot and dust and a device for removing impurities.

[0064] By providing the exhaust gas treatment means 14, insoluble NO mainly containing NO that is insoluble in water can be removed. Ｘ (Mainly fuel No. Ｘ In other words, when the staged combustion rate is increased, the amount of insoluble NOx mainly containing NOx that is insoluble in water increases, as shown by the solid line in FIG. Ｘ While the concentration of NOx decreases, the proportion of unburned carbon increases, as shown by the dotted line in Figure 3. Conversely, when the staged combustion ratio is reduced, the proportion of insoluble NOx, which mainly contains NOx that is insoluble in water, increases, as shown by the solid line in Figure 3. Ｘ While the concentration increases, the proportion of unburned carbon decreases, as shown by the dotted line in FIG.

[0065] By providing the exhaust gas treatment means 14 (using the system shown in FIG. 1), the two-stage combustion rate can be increased and the air ratio can be reduced, thereby reducing the amount of insoluble NOx, which mainly contains NOx that is insoluble in water. Ｘ (Mainly fuel No. Ｘ ), and insoluble NO mainly containing water-insoluble NO Ｘ (Mainly fuel No. ＸThis allows for combustion that emits less carbon dioxide, thereby reducing restrictions on combustion. It also allows for combustion that reduces unburned carbon, improving the quality of the ash and promoting the use of ash.

[0066] Furthermore, NH ３ Since there is no need to add NH to denitrify the exhaust gas, corrosion of the pipes can be suppressed. ３ Since no NH3 is added, the dust collected in the dust removal equipment is ３ There is no adhesion.

[0067] Another embodiment of a power generation facility to which a system for recovering reactive nitrogen in a combustion process is applied will be described with reference to FIG.

[0068] FIG. 4 shows a schematic diagram of the overall system of a power generation facility to which the reactive nitrogen recovery system in the combustion process having the above-described configuration is applied.

[0069] As shown in Figure 4, a power generation facility (thermal power generation facility) 21 is equipped with a combustor 22 that uses natural gas as fuel to obtain combustion gas, and compressed air is supplied to the combustor 22 from a compressor 23. The high-temperature, high-pressure combustion gas (high-pressure fluid) from the combustor 22 is expanded and driven by an expansion turbine 24, and power is generated by driving the expansion turbine 24. An exhaust gas treatment means 25 is also provided to treat exhaust gas that has completed its work in the expansion turbine 24 (exhaust gas after generating power).

[0070] The exhaust gas treatment means 25 is provided with the system shown in Fig. 1, similar to the power generation facility shown in Fig. 2. That is, insoluble NOx in the exhaust gas, which mainly contains NOx insoluble in water, is treated. Ｘ (N contained in combustion air ２ NO derived from Ｘ : Thermal NO Ｘ ) into water-soluble nitrogen oxides (NO ２ , N ２ O ３ , N ２ O ４ , N ２ O ５ For example, mainly N ２ O ５ Nitrogen oxides including: N２ O ５ ) is provided, and the N oxidized by the oxidation means 2 is ２ O ５ Dissolve NO ３ － The NO dissolved in the dissolving / oxidizing means 3 is provided. ３ － to nitrates and recovering the nitrates.

[0071] The nitrogen oxides oxidized by the oxidation means 2 are N ２ O ５ In this case, the dissolution and oxidation means 3 is N ２ O ５ The nitrogen oxides oxidized by the oxidation means 2 are dissolved in N ２ O ５ If other than (NO ２ The dissolving / oxidizing means 3 dissolves and oxidizes nitrogen oxides, and the nitrogen oxides are dissolved and oxidized by the dissolving / oxidizing means 3 to produce NO ３ － It is said that.

[0072] Then, the NO dissolved by the dissolving / oxidizing means 3 ３ － is reduced to NH ４ ＋ (reduction means 5), and ４ ＋ NH ３ The apparatus is provided with a conversion means 6 that converts the ammonium salt into ammonium salt and recovers it. When the ammonium salt is recovered by the conversion means 6, the recovered ammonium salt is recovered as, for example, a fertilizer.

[0073] The combustor 22 contains NH recovered by the conversion means 6. ３ When sulfur is contained in the fuel, the dissolving and oxidizing means 3 dissolves the SO ２ are simultaneously absorbed.

[0074] By providing the exhaust gas treatment means 25 (using the system shown in FIG. 1), insoluble NO mainly containing NO that is insoluble in water can be removed. Ｘ (Mainly thermal NO Ｘ), and insoluble NO mainly containing water-insoluble NO Ｘ (Mainly thermal NO Ｘ ) combustion is possible, and restrictions on combustion can be reduced.

[0075] The reactive nitrogen recovery system in the combustion process of the present invention can be installed in the exhaust systems of diesel engines of large vehicles, ships, etc., as well as in power generating systems.

[0076] The present invention relates to a method for producing insoluble NOx emitted in a combustion process, the method comprising the steps of: Ｘ The present invention can be used in industrial fields such as recovery systems for recovering valuable reactive nitrogen, and power generation facilities.

[0077] REFERENCE SIGNS LIST 1 Combustion means 2 Oxidation means 3 Melting and oxidation means 4 First conversion means 5 Reduction means 6 Conversion means 11, 21 Power generation facility 12 Boiler 13 Steam turbine 14, 25 Exhaust gas treatment means 22 Combustor 23 Compressor 24 Expansion turbine

Claims

1. Insoluble NO, which mainly contains NO that is insoluble in water Ｘ and a combustion means for emitting insoluble NOx, mainly including NOx insoluble in water, emitted by the combustion means. Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － and a first conversion means for converting reactive nitrogen to nitrates and recovering the converted reactive nitrogen.

2. Insoluble NO, which mainly contains NO that is insoluble in water Ｘ and a combustion means for emitting insoluble NOx, mainly including NOx insoluble in water, emitted by the combustion means. Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － NH ３ Or ammonium salt, or NH ３ and a second conversion means for converting the reactive nitrogen into an ammonium salt and recovering the same.

3. Insoluble NO, which mainly contains NO that is insoluble in water Ｘ and a combustion means for emitting insoluble NOx, mainly including NOx insoluble in water, emitted by the combustion means. Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － a first conversion means for converting NOx into nitrate and recovering it; and a second conversion means for recovering NOx dissolved or dissolved and oxidized by the dissolution and oxidation means. ３ － NH ３ Or ammonium salt, or NH ３ and a second conversion means for converting the reactive nitrogen into an ammonium salt and recovering the same.

4. In the system for recovering reactive nitrogen in a combustion process according to claim 2 or 3, the second conversion means converts the NO dissolved or dissolved and oxidized by the dissolution and oxidation means into ３ － is reduced to NH ４ ＋ At the same time, reduced NH ４ ＋ NH ３ Or ammonium salt, or NH ３ and recovering the reactive nitrogen from a combustion process by converting the reactive nitrogen into an ammonium salt.

5. In the system for recovering reactive nitrogen in a combustion process according to claim 2 or 3, the NH converted by the second conversion means is ３ is used as fuel for said combustion means.

6. A system for recovering reactive nitrogen in a combustion process according to any one of claims 1 to 3, characterized in that the combustion means obtains a high-pressure fluid by burning a fuel.

7. A system for recovering reactive nitrogen in a combustion process according to any one of claims 1 to 3, characterized in that the combustion means is an engine which obtains power by burning fuel.

8. Insoluble NO, mainly consisting of NO that is insoluble in water Ｘ the combustion means emitting NOx, an expansion turbine expanding a high-pressure fluid obtained by the combustion in the combustion means to obtain power for generating electricity, and an exhaust gas treatment means treating the exhaust gas after the power for generating electricity has been obtained, the exhaust gas treatment means treating insoluble NOx mainly including NOx that is insoluble in water in the exhaust gas, Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － and a first conversion means for converting the above-mentioned nitrate into nitrate and recovering the nitrate.

9. Insoluble NO, mainly consisting of water-insoluble NO Ｘ the combustion means emitting NOx, an expansion turbine expanding a high-pressure fluid obtained by the combustion in the combustion means to obtain power for generating electricity, and an exhaust gas treatment means treating the exhaust gas after the power for generating electricity has been obtained, the exhaust gas treatment means treating insoluble NOx mainly including NOx that is insoluble in water in the exhaust gas, Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － NH ３ Or ammonium salt, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

10. Insoluble NO, mainly consisting of NO that is insoluble in water Ｘ the combustion means emitting NOx, an expansion turbine expanding a high-pressure fluid obtained by the combustion in the combustion means to obtain power for generating electricity, and an exhaust gas treatment means treating the exhaust gas after the power for generating electricity has been obtained, the exhaust gas treatment means treating insoluble NOx mainly including NOx that is insoluble in water in the exhaust gas, Ｘ an oxidation means for oxidizing the water-soluble nitrogen oxides to water-soluble nitrogen oxides; and dissolving or dissolving and oxidizing the water-soluble nitrogen oxides oxidized by the oxidation means to produce NO ３ － a dissolving / oxidizing means for dissolving or oxidizing NOx into NOx, ３ － a first conversion means for converting NO into nitrate and recovering the nitrate; and a second conversion means for recovering the NO dissolved or dissolved and oxidized by the dissolution and oxidation means. ３ － NH ３ Or ammonium salt, or NH ３ and a second conversion means for converting the ammonium salt into an ammonium salt and recovering the ammonium salt.

11. In the power generation facility according to claim 9 or 10, the second conversion means converts the NO dissolved or dissolved and oxidized by the dissolution and oxidation means into ３ － is reduced to NH ４ ＋ At the same time, reduced NH ４ ＋ NH ３ Or ammonium salt, or NH ３ and recovering the ammonium salt by converting the ammonium salt into the ammonium salt.

12. The power generation facility according to claim 9 or 10, wherein the combustion means is configured to use NH ３ The combustion means is configured to include a NH ３ A power generation facility characterized in that:

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