Method and apparatus for combustion of ammonia mixed fuel

Abstract

A method for combustion of an ammonia mixed fuel, according to one embodiment, comprises: a fuel adjustment step of preparing a mixed fuel containing ammonia and hydrogen by mixing ammonia and hydrogen such that hydrogen is mixed in an amount in excess of gaseous ammonia on a volume basis; and a combustion step of supplying the mixed fuel and oxygen to an ammonia combustion catalyst to perform combustion.

Description

Combustion method and apparatus for ammonia mixed fuel

[0001] The present invention relates to a method for burning a mixed fuel containing ammonia and hydrogen and a combustion apparatus.

[0002] Nitrogen oxides (NOx) in the combustion process of fuel x ) emissions are recognized as one of the major factors causing serious impacts on air pollution and human health. Recently, hydrogen (H2) and ammonia (NH3) have emerged as carbon-free fuels because these substances do not contain carbon (C) and thus do not produce carbon dioxide (CO2), which causes global warming, after combustion.

[0003] However, ammonia, considered a clean fuel, also produces NO during the combustion process. x There is a problem where this occurs. Furthermore, when burning a mixed fuel of ammonia and hydrogen to compensate for the low combustibility of ammonia, fuel NO originating from ammonia x (fuel NO x In addition, due to the strong combustibility of hydrogen, thermal NO x (Thermal NO x ) is also generated and NO x There is a risk that the occurrence of will increase significantly.

[0004] NO so far x Various technologies have been studied to reduce emissions, but most technologies post-treat the gases emitted after combustion to produce NO x Concentration has been placed on methods to remove [the substance]. For example, Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR) have been primarily used. However, these methods require the use of catalysts / reducing agents, incurring additional equipment and operating costs, and often have limitations in efficiency, making them impractical.

[0005] Therefore, NO from the combustion process itself x Measures to effectively reduce production volume are receiving more attention, and NO x The development of technology capable of fundamentally suppressing the generation mechanism is required.

[0006] According to one embodiment of the present invention, a method for burning an ammonia-containing mixed fuel and a combustion device in which the generation of nitrogen oxides is suppressed may be provided.

[0007] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0008] A method for burning an ammonia mixed fuel according to one embodiment of the present invention includes a fuel control step of mixing ammonia and hydrogen such that, based on volume, an excess amount of hydrogen is mixed relative to gaseous ammonia to produce a mixed fuel containing ammonia and hydrogen, and a combustion step of supplying the mixed fuel and oxygen to an ammonia combustion catalyst to burn.

[0009] In one embodiment, in the fuel control step, the mixed fuel may contain 1.5 Va to 3.5 Va of hydrogen based on the volume of ammonia Va.

[0010] In one embodiment, in the combustion step, the ratio of oxygen concentration required according to the stoichiometry during the combustion of the mixed fuel is CR Ost As such, 0.60 CR Ost Up to 1.10 CR Ost Oxygen can be supplied to satisfy the concentration ratio.

[0011] In one embodiment, at the combustion step, 0.95 CR Ost Up to 1.05 CR Ost Oxygen can be supplied to satisfy the concentration ratio.

[0012] In one embodiment, the ammonia combustion catalyst may contain copper, copper oxide, or a mixture thereof.

[0013] In one embodiment, the combustion step may be performed at 450 to 800°C.

[0014] A combustion device for an ammonia mixed fuel according to one embodiment of the present invention comprises: a fuel control unit that receives ammonia and hydrogen from an ammonia tank and a hydrogen tank and mixes an excess amount of hydrogen based on the volume of gaseous ammonia to produce a mixed fuel of ammonia and hydrogen; and a combustion unit that receives the mixed fuel and burns the mixed fuel in the presence of an ammonia combustion catalyst.

[0015] In one embodiment, the combustion device further includes a mixing unit provided upstream of the combustion unit, and the mixing unit can mix the oxygen-containing gas and the mixed fuel and supply them to the combustion unit.

[0016] In one embodiment, the mixing unit may include an inline mixer.

[0017] In one embodiment, the combustion device further includes a control unit, and the control unit determines the oxygen concentration ratio required according to the stoichiometry of the oxygen-containing gas supplied to the combustion unit during the combustion of the mixed fuel CR Ost As such, 0.60 CR Ost Up to 1.10 CR Ost The above mixing unit can be controlled to satisfy the concentration ratio.

[0018] In one embodiment, the combustion section includes a combustion space in which a particulate combustion catalyst is filled or a porous structure containing a combustion catalyst is located, and the combustion catalyst may contain copper, copper oxide, or a mixture thereof.

[0019] A combustion method and apparatus according to one embodiment can significantly suppress the generation of nitrogen oxides, including nitrogen dioxide, nitrous oxide, and nitric oxide, while having excellent combustibility of a mixed fuel containing ammonia and hydrogen.

[0020] The various and beneficial advantages and effects of the present invention are not limited to those described above and will be more easily understood in the process of explaining specific embodiments of the present invention.

[0021] FIG. 1 is an example illustrating a configuration diagram of an ammonia mixed fuel combustion device according to one embodiment of the present invention.

[0022] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0023] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0024] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0025] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0026] In this description, expressions such as 'include' or 'comprise' are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0027] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0028] In this specification, terms such as 'top', 'upper', 'upper surface', 'lower', 'lower surface', 'lower surface', and 'side surface' are based on the drawings and may actually vary depending on the direction in which the elements or components are arranged.

[0029] Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between.

[0030] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0031] The inventors noted that hydrogen serves as a combustion accelerator and a clean fuel capable of compensating for the low combustibility of ammonia, and conducted research on combustion technology for mixed fuels containing ammonia and hydrogen. As a result of the research, it was confirmed that the problem of nitrogen oxide generation is more severe during the combustion of ammonia-hydrogen mixed fuel compared to the combustion of ammonia alone. Furthermore, it was confirmed that the combustion characteristics of ammonia alone and the ammonia-hydrogen mixed fuel differ from each other, and therefore the combustion characteristics of the ammonia-hydrogen mixed fuel cannot be inferred from the combustion characteristics of ammonia alone.

[0032] Based on these findings, various studies were conducted to suppress the generation of nitrogen oxides during the combustion of an ammonia-hydrogen mixed fuel while maintaining the excellent combustibility of the fuel. As a result, a technology was developed that can effectively suppress the generation of nitrogen oxides while maintaining high combustibility in which more than 90% of the ammonia is combusted, thereby completing the present invention.

[0033] In the present invention, 'ammonia mixed fuel' or 'mixed fuel' refers to a combustible substance (fuel) and may refer to a gas mixture containing gaseous ammonia and hydrogen.

[0034] In the present invention, the term 'ammonia combustion catalyst' refers to a catalyst that promotes the combustion reaction of ammonia in which ammonia reacts with oxygen to produce nitrogen (N2) and water (H2O). Accordingly, the function and role of the ammonia combustion catalyst differ from those of the ammonia decomposition catalyst, which promotes the decomposition reaction in which ammonia is broken down into nitrogen (N2) and hydrogen (H2).

[0035] In the present invention, 'ammonia' means gaseous ammonia unless specifically limited to a liquid state.

[0036] In the present invention, 'hydrogen' may include not only hydrogen originating from a hydrogen storage tank that stores hydrogen, but also hydrogen produced as a product of an electrochemical reaction or a chemical reaction. An example of such hydrogen as a reaction product is hydrogen produced by an ammonia decomposition reaction.

[0037] In the present invention, the 'stoichiometry' during combustion of the mixed fuel may be the stoichiometric ratio between the mixed fuel and oxygen based on the combustion reaction of ANH3 + 0.75 AO2 → 0.5 AN2 + 1.5 AH2O for A moles of NH3 and the combustion reaction of BH2 + 0.5 BO2 → BH2O for B moles of H2, when the molar ratio of ammonia to hydrogen contained in the mixed fuel is A : B.

[0038] In the present invention, the 'concentration ratio required according to stoichiometry' may mean the concentration ratio of [0.75A + 0.5B] / [A+B] based on the aforementioned stoichiometry.

[0039] In the present invention, the statement that "oxygen is supplied to satisfy the concentration ratio required according to stoichiometry" may mean that when a mixed fuel is supplied to a space where combustion occurs, oxygen is supplied to the space where combustion occurs such that O' / [A'+B'] satisfies [0.75A' + 0.5B'] / [A'+B'], where A' is the total moles of ammonia supplied as mixed fuel per unit time and B' is the total moles of hydrogen supplied as mixed fuel per unit time, and O' is the total moles of oxygen supplied to the space where combustion occurs per unit time. Accordingly, the statement that oxygen is supplied to satisfy (an arbitrary number k) x (concentration ratio) may mean that oxygen is supplied to the space where combustion occurs such that O' / [A'+B'] satisfies (an arbitrary number k) x [0.75A' + 0.5B'] / [A'+B']. At this time, in a space having constant pressure and constant temperature, the molar ratio may correspond to the volume ratio.

[0040] In the present invention, the temperature at which combustion is performed (or the temperature of the combustion stage) may be at least the temperature of the 'ammonia combustion catalyst' where the mixed fuel and oxygen come into contact. As a specific example, the temperature at which combustion is performed (or the temperature of the combustion stage) may be the temperature of the combustion region, which is a region filled with the ammonia combustion catalyst.

[0041] In the present invention, 'nitrogen oxide' may refer to a substance selected from one or more of the group of nitrogen-oxygen compounds, namely nitrogen dioxide, nitrous oxide, and nitric oxide. As a substantial example, nitrogen oxide may refer to nitrogen dioxide, nitrous oxide, and nitric oxide. In the present invention, nitrogen oxide refers to NO x It can also be commonly referred to as [another name].

[0042] A method for burning an ammonia mixed fuel according to the initiation thereof includes a fuel control step of mixing ammonia and hydrogen such that, based on volume, an excess amount of hydrogen is mixed relative to gaseous ammonia to produce a mixed fuel containing hydrogen and ammonia, and a combustion step of supplying the mixed fuel and oxygen to an ammonia combustion catalyst to burn.

[0043] According to the commencement of work, the mixed fuel contains ammonia and hydrogen, wherein the volume of hydrogen exceeds the volume of ammonia, so that both ammonia and hydrogen are combusted with an excellent combustion rate, and at the same time, NO during the combustion of the mixed fuel x The production of can be suppressed.

[0044] In one advantageous example, the fuel control step may be a step of producing a mixed fuel by mixing ammonia and hydrogen such that, based on the ammonia volume Va, the volume of hydrogen is 1.5 Va to 3.5 Va, more advantageously 2.0 Va to 3.5 Va, more advantageously 2.5 Va to 3.5 Va, and more advantageously 2.6 to 3.3 Va.

[0045] In the fuel control stage, by having the aforementioned hydrogen / ammonia volume ratio (hydrogen over-concentration range) in the mixed fuel, the fuel NO due to the high chemical reactivity of hydrogen x (fuel NO x It can reduce ), increase the combustion stability of ammonia, and simultaneously reduce thermal NO caused by a rapid rise in combustion temperature. x (Thermal NO x It can suppress the production of )

[0046] In detail, the aforementioned volume ratio of hydrogen / ammonia (hydrogen over-rich range) is a condition for a mixed fuel capable of exhibiting ammonia combustion capacity of substantially 100% and hydrogen combustion capacity of 90% or more, specifically 95% or more, more specifically 100% during a combustion reaction, and together with this, a condition for a mixed fuel capable of suppressing the generation of nitrogen oxides to approximately 1%, and further to 0%.

[0047] After the fuel control step, a combustion step can be performed in which a mixed fuel having a hydrogen / ammonia volume ratio controlled through the fuel control step and oxygen are supplied to an ammonia combustion catalyst to combust the mixed fuel.

[0048] At this time, before the mixed fuel is supplied to the combustion catalyst, the mixed fuel and oxygen may be pre-mixed and supplied to the ammonia combustion catalyst, or alternatively, the mixed fuel and oxygen may be supplied to the combustion catalyst separately for combustion to occur. In this case, oxygen may be supplied to an oxygen-containing gas, and the oxygen-containing gas may be oxygen gas or air, but is not necessarily limited thereto.

[0049] A combustion method according to one embodiment may further include a pre-mixing step after a fuel control step, wherein a mixed fuel containing mixed fuel is mixed with oxygen to produce a fuel-oxygen mixed gas, and after the pre-mixing step, a combustion step may be performed in which the fuel-oxygen mixed gas is supplied to an ammonia combustion catalyst to combust.

[0050] A combustion method according to another specific embodiment may include, after a fuel control step, a gas supply step in which the mixed fuel and oxygen are each supplied to a combustion space where an ammonia combustion catalyst is located, and a catalytic reaction step in which the mixed fuel in contact with the ammonia combustion catalyst is combusted. At this time, the gas supply step and the catalytic reaction step may correspond to the combustion step described above.

[0051] Regardless of whether the mixed fuel and oxygen are pre-mixed or supplied independently, the ratio of oxygen concentration required according to the stoichiometry during the combustion stage is CR Ost As such, 0.60 CR Ost Up to 1.10 CR Ost Oxygen can be supplied to an ammonia combustion catalyst (or a combustion space equipped with an ammonia combustion catalyst) to satisfy the concentration ratio.

[0052] Along with the volume ratio of hydrogen to ammonia in the mixed fuel, the oxygen conditions during combustion, such as oxygen-sufficient or oxygen-lean conditions, also affect NO x It can have a significant impact on the extent of occurrence.

[0053] In a favorable example, during the combustion phase, 0.60 CR Ost Up to 0.80 CR Ost The concentration ratio of, specifically 0.65 CR Ost Up to 0.75 CR Ost Oxygen can be supplied to an ammonia combustion catalyst (or a combustion space equipped with an ammonia combustion catalyst) to satisfy [condition] (hereinafter, the first oxygen supply condition).

[0054] The first oxygen supply condition is NO during the combustion of the mixed fuel x It is advantageous to be able to achieve a high combustion rate of the mixed fuel, specifically an ammonia combustion rate of 95 to 100% and a hydrogen combustion rate of 80 to 96%, at a lower temperature while suppressing generation.

[0055] In a more favorable example, at the combustion stage, 0.95 CR Ost Up to 1.05 CR OstThe concentration ratio of, specifically 0.98 CR Ost Naeja 1.02 CR Ost The concentration ratio of, more specifically, the concentration ratio according to stoichiometry, CR Ost Oxygen can be supplied to an ammonia combustion catalyst (or a combustion space equipped with an ammonia combustion catalyst) to satisfy [condition] (hereinafter, second oxygen supply condition).

[0056] Under the second oxygen supply condition, a high combustion rate of the mixed fuel is achieved at a relatively higher temperature than under the first oxygen supply condition; however, it can exhibit an ammonia combustion rate reaching practically 100% and a hydrogen combustion rate reaching 100%, and furthermore, NO is reduced to approximately 1%, effectively reaching 0%. x It is advantageous because it can suppress occurrence.

[0057] In the combustion stage, the ammonia combustion catalyst may contain a catalytic material of a precious metal such as silver, gold, platinum, iridium, palladium, rhodium, ruthenium, or mixtures thereof or alloys thereof; and / or a non-precious metal such as iron, cobalt, nickel, copper, or mixtures thereof or alloys thereof. The catalytic material may be in the form of a metal, a metal oxide, or a mixture of a metal and a metal oxide. The combustion catalyst may be in the form of the catalytic material itself or a form in which the catalytic material is supported on a carrier. The carrier may be any material commonly used to support a material that acts as a catalyst in the combustion reaction of ammonia. Representative examples of carriers include metal oxides such as silica, alumina (α, γ), zirconia, titania, magnesia, mixtures thereof, or complex oxides thereof.

[0058] However, it is advantageous for the ammonia combustion catalyst to contain a copper component as a catalytic material. In this case, the copper component may include metallic copper, copper oxide, a mixture thereof, or a complex thereof, and the copper oxide may include Cu2O, CuO, CuO2, Cu2O3, CuO2, or a mixture thereof or a complex thereof.

[0059] When the ammonia combustion catalyst contains a copper component, the combustion rate of the fuel can be further improved during the combustion of the mixed fuel under the aforementioned mixed fuel and oxygen supply conditions, and NO x It can further suppress occurrence.

[0060] The combustion step may be carried out at 450 to 800°C. When the combustion of the mixed fuel is carried out at a temperature of 450°C or higher, the combustion rate of ammonia during combustion may be 90% or higher, substantially 95% or higher, and more substantially 99% or higher.

[0061] As a practical example, the temperature of the combustion stage under the first oxygen supply condition may be 550 to 700°C. When a hydrogen-rich mixed fuel is combusted within the aforementioned temperature range under the first oxygen supply condition, a high fuel combustion rate can be achieved, with an ammonia combustion rate substantially reaching 100% and a hydrogen combustion rate substantially exceeding 80%, and NO during combustion x The incidence rate can be kept within 5%.

[0062] As a more practical example, under the first oxygen supply conditions, the temperature of the combustion stage may be 650 to 700°C, and in this case, NO during combustion x The incidence rate can be kept within 3%.

[0063] As a practical example, the temperature of the combustion stage under the second oxygen supply condition may be 650 to 800°C. When a hydrogen-rich mixed fuel is combusted within the aforementioned temperature range under the second oxygen supply condition, a high fuel combustion rate can be achieved, with an ammonia combustion rate substantially reaching 100% and a hydrogen combustion rate substantially exceeding 90%, and NO during combustion x The incidence rate can be kept within 1.5%.

[0064] As a more practical example, under second oxygen supply conditions, the temperature of the combustion stage may be 700 to 800°C, in which case an ammonia combustion rate substantially reaching 100% and a hydrogen combustion rate substantially reaching 100% may be achieved, and NO during combustion x The incidence rate can practically reach 0%.

[0065] The mixed fuel is 5,000 to 100,000 mL·g cat -1 ·h -1 It can be supplied to the ammonia combustion catalyst (combustion space where the combustion catalyst is located) at a space velocity, but is not necessarily limited to this.

[0066] The present invention includes an ammonia mixed fuel combustion device in which the aforementioned ammonia mixed fuel combustion method is implemented. Accordingly, the ammonia mixed fuel combustion device includes all the details described above in the ammonia mixed fuel combustion method.

[0067] An ammonia mixed fuel combustion device according to the invention comprises a fuel control unit that receives ammonia (A) and hydrogen (H) from an ammonia tank and a hydrogen tank and mixes an excess amount of hydrogen based on the volume of gaseous ammonia to produce a mixed fuel (M) containing ammonia and hydrogen, and a combustion unit that receives the mixed fuel and burns the mixed fuel in the presence of an ammonia combustion catalyst. For the combustion of the mixed fuel, the combustion unit may receive oxygen together with the mixed fuel or independently of the mixed fuel.

[0068] FIG. 1 is an example illustrating a configuration diagram of an ammonia mixed fuel combustion device according to one embodiment. As shown in the example of FIG. 1, the combustion device may include a fuel control unit (100) and a combustion unit (200). The fuel control unit (100) receives ammonia (A) and hydrogen (H) from an ammonia storage tank (10) that stores ammonia and a hydrogen storage tank (20) that stores hydrogen, and mixes the ammonia and hydrogen to produce a mixed fuel (M) such that the hydrogen volume Vh satisfies the hydrogen over-rich condition Vh / Va > 1 based on the ammonia volume Va.

[0069] The mixed fuel (M) generated in the fuel control unit (100) is supplied to the combustion unit (200) where the ammonia combustion catalyst is located and combusted, and can generate a gas (exhaust gas, shown by a dotted arrow) containing combustion energy and combustion reaction products. At this time, as is well known, the combustion energy can be converted into mechanical energy through the operation of a turbine, etc. or steam generated by heat exchange.

[0070] In the combustion section (200), at least a portion of the space where combustion occurs (combustion space) may be filled with a porous structure such as a particulate, pellet, or honeycomb containing an ammonia combustion catalyst. For example, the combustion space may include a catalyst area (catalyst bed) filled with a particulate combustion catalyst. When a particulate combustion catalyst is filled, the contact area between the combustion catalyst and the gas phase can be improved as the gas phase flows through the empty spaces between the particles. As another example, the combustion space may be provided with a porous structure having one or more flow paths in the direction of gas flow. In this case, the combustion catalyst may be coated on the surface of the porous structure, or the combustion catalyst itself may form the porous structure. Additionally, although not shown in the drawing, the combustion section (200) may further include a heat source that supplies heat to the combustion space to control the combustion temperature and / or a cooling member that cools the combustion space through a heat exchange, etc.

[0071] As illustrated in FIG. 1, based on the gas flow, the combustion device may further include a mixing section (300) located upstream of the combustion section (200). The mixing section (300) receives a mixed fuel (M) and an oxygen-containing gas (O) to produce a reaction gas (R), and the produced reaction gas (R) can be supplied to the combustion section (200). Typical examples of the mixing section (300) include an in-line mixer.

[0072] Unlike the example illustrated in FIG. 1, the combustion unit (200) may receive oxygen-containing gas independently of the mixed fuel. Specifically, oxygen is supplied from an oxygen storage tank (not shown) in which an oxygen source is stored, and the required concentration ratio (C) according to stoichiometry is supplied. Ost Oxygen can be supplied to the combustion unit (200) to satisfy a preset concentration based on ). The oxygen-containing gas may be oxygen gas or air, and if the oxygen-containing gas is air, the air may be supplied from the atmosphere to the combustion unit (200) or the mixing unit (300).

[0073] The combustion device may further include a control unit (not shown). The control unit controls a supply unit that supplies oxygen-containing gas to a mixing unit (300) or a combustion unit (200) to control the oxygen concentration ratio required according to stoichiometry during the combustion of the mixed fuel CR Ost As such, 0.6 CR Ost to 1.1 CR Ost Oxygen satisfying the concentration ratio can be controlled to be supplied to the combustion unit (200). Additionally, the control unit can control the volume ratio of ammonia gas and hydrogen gas in the mixed fuel by controlling the amount of ammonia gas and hydrogen gas supplied from the ammonia tank (10) and the hydrogen tank (20) to the fuel control unit (100).

[0074] Mixing of fluids such as ammonia, hydrogen, and oxygen can be performed using a static mixing method or a dynamic mixing method. That is, the fuel control unit (100) or the mixing unit (300) may independently include a static mixer or a dynamic mixer.

[0075] Although not shown in the drawing, the combustion device may further include conventional control devices for controlling the flow rate and flow rate of fluids, such as a flow control device (e.g., MFC, valve), a pressure regulator, a nozzle, a compressor, a blower, a pump, and piping, for transporting and supplying fluids, and the control unit may control these control devices to drive the combustion device in accordance with the ammonia mixed fuel combustion method described above.

[0076] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0077] (Examples and Comparative Examples)

[0078] An ammonia combustion catalyst of CuO was packed into a reactor, and 72,000 mL·g of reaction gas containing ammonia and hydrogen was introduced into the reactor at a temperature (T, °C) according to Table 1. cat -1 ·h -1 Combustion reactions were carried out while flowing at a space velocity (WHSV). At this time, the ammonia gas content in the reaction gas was 1 volume%, and the ratio of hydrogen volume to ammonia gas volume (Vh / Va) for each reaction gas is summarized in Tables 1 and 2. Helium, a non-combustible gas, was used as the remaining gas excluding hydrogen and ammonia in the reaction gas. Based on the volume ratio of hydrogen and ammonia contained in each reaction gas, the ammonia content in the reaction gas, and the space velocity of the reaction gas, the oxygen concentration ratio (CR) required according to stoichiometry for the combustion of the mixed fuel in the reaction gas Ost k·CR based on ) OstOxygen was supplied to satisfy [condition], and the oxygen was mixed with the reaction gas through a static mixer at the front of the reactor inlet and injected into the combustion reactor. The oxygen supply condition k values ​​based on the stoichiometric ratio are also summarized in Tables 1 and 2.

[0079] The gas emitted from the combustion reactor was analyzed by FT-IR (Fourier-transform infrared spectroscopy) to measure the ammonia combustion rate (CRA, %) and hydrogen combustion rate (CRH, %), and these results are summarized in Table 1. In addition, the content of each substance among the total nitrogen-containing compounds (N2, NO, NO2, N2O) contained in the gas emitted from the combustion reactor (N2, N2O, NO, NO2 in Table 1, each unit is volume%) was analyzed and summarized in Tables 1 and 2.

[0080] TVh / VakCRACRHN2N2ONONO2 Example 14502.9199.548.266.27.825.20.8 Example 25002.91100.068.266.73.829.40.1 Example 35502.91100.075.472.40.027.60.0 Example 46002.91100.081.677.62.519.90.0 Example 56502.91100.090.598.91.10.00.0 Example 67002.91100.0100.0100.00.00.00.0 Example 77502.91100.0100.0100.00.00.00.0 Example 88002.91100.0100.0100.00.00.00.0 Example 94502.90.796.959.864.09.026.20.8 Example 105002.90.7100.082.980.53.415.70.4 Example 115502.90.7100.095.195.00.94.10.0 Example 126002.90.7100.095.297.31.01.60.1 Example 136502.90.7100.086.898.71.30.00.0 Example 147002.90.7100.079.698.81.20.00.0 Example 157502.90.783.980.097.72.00.30.0 Example 168002.90.776.487.995.33.90.80.0 Example 175502.90.999.586.284.61.813.60.0 Example 186002.90.999.692.086.51.911.60.0 Example 196502.90.9100.096.082.33.114.60.0 Example 207002.90.9100.0100.085.60.014.40.0 Example 217502.90.9100.0100.086.31.412.30.0 Example 228002.90.9100.0100.089.42.28.40.0

[0081] TVh / VakCRACRHN2N2ONONO2 Example 77502.91100.0100.0100.00.00.00.0 Example 237502.61100.0100.0100.00.00.00.0 Example 247503.31100.0100.0100.00.00.00.0 Example 257504.11100.0100.079.18.012.90.0 Example 2675023.81100.099.371.53.424.30.8 Comparative Example 175001100.0-66.95.827.30.0

[0082] Through the example results in Tables 1 and 2, it was confirmed that ammonia combusted by more than 90% at combustion temperatures of 450°C or higher, and hydrogen combusted by more than 80% at temperatures of 600°C or higher. Furthermore, it was observed that N2 selectivity is controlled by adjusting the volume ratio of hydrogen to ammonia in the mixed fuel, and that the mixed fuel undergoes complete combustion and NO₂ in the mixing ratio range where Vh / Va is 2.6 to 3.3. x It can be seen that the generation is substantially and completely suppressed. Furthermore, as a result of burning the mixed fuel under oxygen-deficient conditions (k=0.7, 0.9) and conditions based on the stoichiometric ratio (k=1) based on the stoichiometric composition ratio, it can be seen that under the condition where oxygen is significantly deficient compared to the stoichiometric ratio (k=0.7), the ammonia combustion rate and N2 selectivity are greatly improved at a relatively low oxidation reaction temperature, and when oxygen is supplied at the stoichiometric composition ratio (k=1), it can be seen that the N2 selectivity reaches 100% along with the complete combustion of the mixed fuel. The present invention is not limited to the embodiments described above but can be manufactured in various different forms, and those skilled in the art will understand that the present invention can be implemented in other specific forms without altering the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A fuel control step for producing a mixed fuel containing ammonia and hydrogen by mixing ammonia and hydrogen such that, based on volume, an excess amount of hydrogen is mixed relative to gaseous ammonia, and A method for burning ammonia mixed fuel, comprising a combustion step of supplying the mixed fuel and oxygen to an ammonia combustion catalyst to burn.

2. In Paragraph 1, A method for burning an ammonia mixed fuel, wherein, in the fuel control step above, the mixed fuel contains hydrogen in an amount of 1.5 Va to 3.5 Va based on the volume Va of ammonia.

3. In Paragraph 1, In the above combustion stage, the ratio of oxygen concentration required according to the stoichiometry during the combustion of the above mixed fuel is CR Ost As such, 0.60 CR Ost Up to 1.10 CR Ost A method of combustion of an ammonia mixed fuel in which oxygen is supplied to satisfy the concentration ratio.

4. In Paragraph 3, In the above combustion step, 0.95 CR Ost Up to 1.05 CR Ost A method of combustion of an ammonia mixed fuel in which oxygen is supplied to satisfy the concentration ratio.

5. In any one of paragraphs 1 through 4, The above ammonia combustion catalyst is a method for burning ammonia mixed fuel containing copper, copper oxide, or a mixture thereof.

6. In any one of paragraphs 1 through 4, A method for burning ammonia mixed fuel, wherein the combustion step is performed at 450 to 800°C.

7. A fuel control unit that supplies ammonia and hydrogen from an ammonia tank and a hydrogen tank, mixes an excess amount of hydrogen based on the volume of gaseous ammonia, and produces a mixed fuel of ammonia and hydrogen; and An ammonia mixed fuel combustion device comprising: a combustion section in which the mixed fuel is supplied from the fuel control section and the mixed fuel is combusted in the presence of an ammonia combustion catalyst.

8. In Paragraph 7, The above combustion device further includes a mixing section provided upstream of the combustion section, and the mixing section mixes an oxygen-containing gas with the mixed fuel and supplies it to the combustion section, an ammonia mixed fuel combustion device.

9. In Paragraph 8, The above mixing section is an inline mixer, an ammonia mixed fuel combustion device.

10. In Paragraph 8, The above combustion device further includes a control unit, and the control unit determines the oxygen concentration ratio CR required according to the stoichiometry of the oxygen-containing gas supplied to the combustion unit during the combustion of the mixed fuel. Ost As such, 0.60 CR Ost Up to 1.10 CR Ost An ammonia mixed fuel combustion device that controls the mixing section to satisfy the concentration ratio of the above.

11. In Paragraph 7, The above combustion section comprises a combustion space in which a particulate combustion catalyst is filled or a porous structure containing a combustion catalyst is located, and the combustion catalyst contains copper, copper oxide, or a mixture thereof, in an ammonia mixed fuel combustion device.

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