Fuel additive for desulfurization, denitrification and deammoniation in combustion of ammonia-blended fuel in thermal power plants and its application

Abstract

The present application provides a fuel additive for desulfurization, denitrification and deammoniation in the combustion of ammonia-blended fuel in thermal power plants and its application, which relates to the technical field of fuel additives. The fuel additive includes solvent A, solvent B and solute C in a mass ratio of 2:1:1-2, the solvent A includes formic acid, salicylic acid and water, the solvent B includes methyl formate and methyl salicylate, the solute C includes organic metal salts and inorganic metal salts, and the organic metal salts include rare earth benzoate. By combining solvent A, solvent B and a specific solute C, the additive can effectively promote the combustion process of coal, improve combustion efficiency, reduce pollutants such as sulfur oxides, nitrogen oxides and particulate matter generated by combustion and the residue of ammonia components after ammonia combustion, and may also improve the ignition performance and combustion stability of coal.

Description

Technical Field

[0001] The present application relates to the technical field of fuel additives, and in particular to a fuel additive for desulfurization, denitrification and deammoniation in the combustion of ammonia-blended fuel in thermal power plants and its application. Background Art

[0002] During the fuel combustion process in thermal power plants, sulfur dioxide (SO2) and nitrogen oxides (NOx) in flue gas are the main air pollutants. Incomplete combustion of ammonia fuels will leave a certain amount of ammonia, which will pose a serious threat to the environment and human health. In order to reduce the emission of these pollutants, fuel additives have been widely used in thermal power plants as an effective means of desulfurization, denitrification and deammoniation.

[0003] However, the fuel additives currently on the market still have many deficiencies in terms of desulfurization, denitrification and deammoniation effects. On the one hand, the desulfurization efficiency of many additives is not high and they cannot effectively reduce the SO2 concentration in the flue gas. This may be due to the fact that the active ingredients of the additives are not stable enough or they fail to fully contact and react with the SO2 in the flue gas during the combustion process. On the other hand, for the removal of NOx and NH3, traditional additives often rely on their reaction with reducing agents (such as residual ammonia) in the flue gas, but the reaction rate of this process is slow and is easily affected by conditions such as temperature and pressure, resulting in poor denitrification effects.

[0004] Therefore, there is an urgent need to develop a new type of fuel additive to improve the desulfurization, denitrification and deammoniation effects in the combustion of ammonia-blended fuel in thermal power plants. Summary of the invention

[0005] In order to improve the problems of low desulfurization, denitrification and deamination efficiency and poor desulfurization, denitrification and deamination effects of current ammonia-blended fuel additives in power plants, the present application provides a fuel additive for desulfurization, denitrification and deamination in the combustion of ammonia-blended fuel in thermal power plants and its application.

[0006] In the first aspect, the present application provides a fuel additive for desulfurization, denitrification and deammoniation in the combustion of ammonia-blended fuel in thermal power plants, using the following technical solution:

[0007] A fuel additive for desulfurization, denitration and deammoniation in the combustion of ammonia-blended fuel in a thermal power plant, comprising a solvent A, a solvent B and a solute C in a mass ratio of 2:1:1-2, wherein the solvent A comprises formic acid, salicylic acid and water.

[0008] The solvent B includes methyl formate and methyl salicylate,

[0009] The solute C includes an organic metal salt and an inorganic metal salt, and the organic metal salt includes a rare earth benzoate.

[0010] The fuel additive of the present invention is composed of solvent A, solvent B and specific solute C, wherein solvent A has the function of promoting combustion and dissolving metal salts, and avoiding precipitation of metal salts during dissolution, storage and use. Water in the solvent can generate water gas with coal at high temperature and dissolve solid acid. Solvent B is an organic solvent used to dissolve metal salts, and can also accelerate the diffusion of organic metal salts in fuel combustion and cracking products, and accelerate the dissolution in coal combustion and cracking products. Solute C is an active ingredient, and organic metal salts and inorganic metal salts can make up for the different solubility between different substances, react with sulfur, nitrogen, oxygen and hydrogen elements during the combustion process, and realize efficient desulfurization, denitration and deammoniation in the combustion process of ammonia-blended fuel in thermal power plants, thereby significantly improving the desulfurization and denitration efficiency, reducing emission concentration, and reducing energy consumption and production costs.

[0011] In addition, the organic solvent forms an emulsion with the aqueous solution. The solution formed in this way can be adapted to both organic combustion products and inorganic substances that penetrate into the organic combustion products. Through the complementarity of polar and non-polar solutions, the performance of various components in fuel combustion and cracking can be met.

[0012] The fuel additive provided in the present application can effectively promote the combustion process of the fuel, improve the combustion efficiency, reduce pollutants such as sulfur oxides, nitrogen oxides and particulate matter generated by combustion, accelerate the cracking and bond breaking and redox reactions of ammonia, and may also improve the combustion stability of the fuel.

[0013] Optionally, the mass ratio of the solvent A, the solvent B and the solute C is 4:2:3.

[0014] The present application can ensure the optimal ratio of each component in the additive by further optimizing the mass ratio of solvent A, solvent B and solute C, which not only ensures the solubility and stability of the additive, but also gives full play to the catalytic efficiency of each component to achieve efficient combustion.

[0015] Optionally, the rare earth metal ions in the rare earth benzoate salt include Dy 3+ , Tb 3+ 、Ho 3+ , Er 3+ and Yb 3+ .

[0016] This application is made by selecting Dy 3+ , Tb 3+ 、Ho 3+ , Er 3+ and Yb 3+These five rare earth metal ions have unique electronic configuration and catalytic properties, and can effectively undergo redox reactions with sulfur and nitrogen during the combustion process, further improving the efficiency of desulfurization, denitrification and deammonification, making the concentration of discharged pollutants lower and meeting higher environmental protection standards. At the same time, these rare earth metal ions also have good stability and regeneration, and can maintain efficient desulfurization, denitrification and deammonification performance for a long time.

[0017] Optionally, the rare earth benzoate salt comprises equimolar amounts of Yb(C6H5COO)3, Tb(C6H5COO)3, Ho(C6H5COO)3, Dy(C6H5COO)3, and Er(C6H5COO)3.

[0018] Optionally, the organic metal salt further includes copper formate, manganese formate, iron p-toluenesulfonate, molybdenum dialkyldithiocarbamate, iron acrylate, nickel acrylate and nickelocene.

[0019] This application uses the above organic metal salts to release active metal ions during the combustion process. These metal ions can react with sulfur and nitrogen elements in the fuel to generate harmless compounds (such as sulfates, nitrates, etc.). Therefore, by further limiting the organic metal salts, the efficiency of desulfurization, denitration and deamination can be significantly improved, the waste of metal ions can be reduced, and the production cost can be reduced. At the same time, these organic metal salts also have good thermal stability and chemical stability, can maintain activity at high temperatures, and continue to play the role of desulfurization, denitration and deamination.

[0020] Optionally, the inorganic metal salt includes iron pyrophosphate and nickel molybdate.

[0021] The present application utilizes the above inorganic metal salts to form active molybdenum oxide species during the combustion process, which can undergo redox reactions with sulfur and nitrogen elements in the fuel, thereby reducing the concentrations of sulfur oxides, nitrogen oxides, and ammonia in the emissions. Therefore, by further limiting the inorganic metal salts, the desulfurization, denitration, and deammoniation capabilities can be further enhanced, making the concentration of pollutants emitted lower. At the same time, these inorganic metal salts also have good catalytic performance and regeneration, and can maintain efficient desulfurization, denitration, and deammoniation performance for a long time.

[0022] In addition, the present application can not only provide a variety of catalytic active sites through the cooperation of organic metal salts and inorganic metal salts, accelerate the breakage of NH3, form active groups such as O- and OH- from water and O2, and accelerate the chain breakage of various macromolecular organic substances, but also enhance the penetration of additives into the fuel surface and internal structure through the synergistic effect of organic and inorganic components, improve the catalytic efficiency, provide more comprehensive catalytic effects on different components in the fuel, and help improve combustion efficiency and reduce pollutant emissions.

[0023] Optionally, the solvent A also includes methanol, and the mass ratio of formic acid, salicylic acid, methanol and water in the solvent A is 5:1:2:10.

[0024] The present application further improves the volatility and solubility of solvent A by adding methanol to solvent A, so that some alcohol-soluble and water-soluble organic metal salts can quickly penetrate into some alcohol-soluble organic matter. At the same time, methanol can also promote the redox reaction during the combustion process, further improving the desulfurization, denitrification and deammoniation efficiency.

[0025] Optionally, the solute C further comprises a complexing agent, and the complexing agent comprises tartaric acid and ammonium sulfonate.

[0026] The present application adds a complexing agent to the solute C, and can use the complexing agent to form a stable complex with the metal ions to prevent them from agglomerating or precipitating. At the same time, the complexing agent can also improve the solubility and dispersibility of the additive, so that it can be more evenly distributed in the fuel. In addition, the complexing agent can also promote the redox reaction during the combustion process, further improving the desulfurization, denitrification and deammoniation efficiency.

[0027] Optionally, the molar amount of the complexing agent is equal to the sum of the molar amounts of the organic metal salt and the inorganic metal salt.

[0028] By further limiting the molar amount of the complexing agent, it is possible to ensure that the metal ions and the complexing agent fully react and combine, so that the complexing agent can completely wrap the metal ions to form a stable complex, preventing them from agglomerating or precipitating during the combustion process. Therefore, the complexing agent can make the metal ions more evenly distributed in the fuel during the combustion process, thereby further improving the desulfurization, denitrification and deammoniation efficiency.

[0029] In the second aspect, the present application provides an application of a fuel additive for desulfurization, denitrification and deamination in the combustion of ammonia-blended fuel in a thermal power plant, using the following technical solution:

[0030] The application is to apply the fuel additive to the combustion of water-coal slurry, specifically, to add the fuel additive to the water-coal slurry and spray it into the water-coal slurry boiler together with the water-coal slurry, ammonia gas or liquid ammonia.

[0031] Adding additives to water-coal slurry can significantly improve the combustion performance of water-coal slurry, reduce the difficulty of ignition, improve combustion efficiency, and reduce pollutant emissions. It is of great significance to improve the operating efficiency and environmental protection performance of water-coal slurry boilers.

[0032] In a third aspect, the present application provides another application of a fuel additive for desulfurization, denitrification and deamination in the combustion of ammonia-blended fuel in a thermal power plant, using the following technical solution:

[0033] The application is to apply the fuel additive to coal powder combustion or coal gasification combustion, specifically, the fuel additive is formulated into an additive aqueous solution with a mass fraction of 1%-5%, and mixed with coal, ammonia or liquid ammonia in the form of gaseous spray.

[0034] By preparing an aqueous solution of additives at a certain concentration and mixing it with ammonia and coal in the form of a gaseous spray, the additives can be evenly distributed and efficiently utilized in the coal powder or coal gasification process, significantly improving combustion efficiency, reducing pollutant emissions, and possibly improving the ignition performance and combustion stability of coal powder.

[0035] Optionally, the additive aqueous solution further includes 1%-2% by mass of a rapid dispersant and 1%-2% by mass of a rapid penetrant.

[0036] Adding fast dispersants and fast penetrants to the additive aqueous solution can further enhance the dispersibility and permeability of the additive in coal powder or coal gasification process, so that the metal salt can quickly disperse and penetrate in the fuel to play a catalytic role, thereby improving combustion efficiency and environmental performance.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. The main active ingredients of the fuel additive provided by the present application are organic metal salts and inorganic metal salts. The organic metal salts can form complexes with fuel combustion and cracking products (such as heterocyclic compounds, benzene series, various hydrocarbons, tar, etc.) through the principle of like dissolves like. This coordination can accelerate the cracking reaction of coal and improve the combustion efficiency. The inorganic metal salts can release active oxygen species (such as O 2- , O - These active oxygen species have strong oxidizing properties and can efficiently react with sulfur and nitrogen in the fuel to generate harmless compounds such as sulfates and nitrates. At the same time, inorganic metal salts can also act as catalysts to reduce the activation energy of redox reactions and accelerate the reaction process.

[0039] 2. Inorganic metal salts can also accelerate the reaction of NH3 and NOx in the flue gas after combustion to produce N2. Moreover, the stability and high activity of inorganic metal salts enable them to remain active in a high-temperature combustion environment, and work together with organic metal salts to further reduce the concentration of pollutants such as SO2 and NOx in the flue gas;

[0040] 3. The metal sulfide produced by the reaction of organic metal salts with sulfur in the fuel can still play a catalytic role and also play a role in flue gas desulfurization. DETAILED DESCRIPTION

[0041] In order to make the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments. Example

[0042] Embodiment 1 provides a fuel additive, which is specifically formed by mixing solvent A, solvent B and solute C in a mass ratio of 4:2:3.

[0043] Solvent A is composed of formic acid, salicylic acid and water in a mass ratio of 5:1:10;

[0044] Solvent B consists of methyl formate and methyl salicylate in a molar ratio of 1:1;

[0045] The solute C is composed of an organic metal salt and an inorganic metal salt, wherein the organic metal salt includes 1 molar part of copper formate, 1 molar part of manganese formate, 1 molar part of iron p-toluenesulfonate, 2 molar parts of dialkyldithiocarbamate molybdenum, 1 molar part of iron acrylate, 2 molar parts of nickel acrylate, 2 molar parts of nickelocene, and 2 molar parts of rare earth benzoate; the inorganic metal salt includes 1 molar part of iron pyrophosphate and 1 molar part of nickel molybdate; and the rare earth benzoate is composed of Yb(C6H5COO)3, Tb(C6H5COO)3, Ho(C6H5COO)3, Dy(C6H5COO)3, and Er(C6H5COO)3 in a molar ratio of 1:1:1:1:1.

[0046] Example 2

[0047] Example 2 is substantially the same as Example 1, except that the solute C in Example 2 further includes a complexing agent, which is composed of 7 molar parts of ammonium sulfonate and 7 molar parts of tartaric acid.

[0048] Example 3

[0049] Example 3 is substantially the same as Example 2, except that the solvent A in Example 3 is composed of formic acid, salicylic acid, methanol and water in a mass ratio of 5:1:2:10.

[0050] Application Example 1

[0051] The fuel additive prepared in Examples 1-3 was subjected to industrial tests in a water-coal slurry boiler. The fuel was mixed with water-coal slurry and ammonia fuel in a mass ratio of 1:1, and the fuel additive was added by spraying the fuel additive into the water-coal slurry boiler together with the fuel, and the addition amount was 0.1wt.%, that is, 1kg of fuel additive was added per ton of fuel. Under the same coal type and boiler operating conditions, the fuels to which the fuel additives prepared in Examples 1-3 were added were used as test groups, and the fuels to which the fuel additives were not added were used as blank groups. The concentrations of SOx, NOx, and NH3 in the fuel combustion flue gas of the test groups and the blank groups were measured respectively. During the measurement, each group of tests selected 3 identical detection sites at the flue gas outlet for detection, and the detection results are shown in Table 1.

[0052] Table 1 Flue gas pollutant emission data of coal water slurry combustion in each embodiment and blank group

[0053]

[0054] Application Example 2

[0055] The fuel additive prepared in Examples 1-3 was subjected to industrial testing in a pulverized coal furnace. The fuel was mixed with pulverized coal and ammonia fuel in a mass ratio of 1:1. The fuel additive was first prepared into a 1wt.% aqueous solution of the additive, and then the aqueous solution of the additive was sprayed in the pulverized coal in a gaseous spray manner to mix with the pulverized coal. Specifically, the aqueous solution of the additive contained 1wt.% of the fuel additive, 1wt.% of the rapid dispersant (sodium humate), 1wt.% of the rapid penetrant (T-50) and the remainder of water. The amount of the aqueous solution of the additive was 10wt.%, that is, 100kg of the aqueous solution of the additive was added per ton of fuel. Under the same coal type and pulverized coal furnace working conditions, the fuels to which the aqueous solution of the additive prepared in Examples 1-3 was added were used as test groups, and the fuels to which the aqueous solution of the additive was not added were used as blank groups. The concentrations of SOx, NOx, and NH3 in the flue gas of the fuel combustion in the test group and the blank group were measured respectively. During the measurement, each group of tests selected 3 identical detection sites at the flue gas outlet for detection, and the detection results are shown in Table 2.

[0056] Table 2 Emission data of flue gas pollutants from pulverized coal combustion in various embodiments and blank groups

[0057]

[0058] It can be seen from the results in Table 1 and Table 2 that the fuel additives in Example 1, Example 2 and Example 3 can effectively reduce the concentrations of SOx, NOx and NH3 in the flue gas from the combustion of the fuel.

[0059] Compared with Example 1, Example 2 adds a chelating agent, which can form a stable complex with the metal ions to prevent them from agglomerating or precipitating; at the same time, the chelating agent can also improve the solubility and dispersibility of the additive, so that it can be more evenly distributed in the fuel, thereby further reducing the concentrations of SOx, NOx, and NH3 in the flue gas of fuel combustion.

[0060] Compared with Example 2, in Example 3, due to the addition of methanol, the volatility and solubility of solvent A can be further improved, so that some alcohol-soluble and water-soluble organic metal salts can quickly penetrate into some alcohol-soluble organic matter, thereby further reducing the SOx, NOx, and NH3 concentrations in the fuel combustion flue gas.

[0061] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants, characterized in that: The invention comprises a solvent A, a solvent B and a solute C in a mass ratio of 2:1:1-2, wherein the solvent A comprises formic acid, salicylic acid and water, The solvent B includes methyl formate and methyl salicylate, The solute C includes an organic metal salt and an inorganic metal salt, and the organic metal salt includes a rare earth benzoate; The rare earth metal ions in the rare earth benzoate salt include Dy 3+ , Tb 3+ 、Ho 3+ , Er 3+ and Yb 3+ ; The organic metal salts also include copper formate, manganese formate, iron p-toluenesulfonate, molybdenum dialkyldithiocarbamate, iron acrylate, nickel acrylate and nickelocene; The inorganic metal salts include iron pyrophosphate and nickel molybdate.

2. The fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants according to claim 1, characterized in that: The solvent A also includes methanol, and the mass ratio of formic acid, salicylic acid, methanol and water in the solvent A is 5:1:2:

10.

3. The fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants according to claim 1, characterized in that: The solute C further comprises a complexing agent, and the complexing agent comprises tartaric acid and ammonium sulfonate.

4. The fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants according to claim 3, characterized in that: The molar amount of the complexing agent is equal to the sum of the molar amounts of the organic metal salt and the inorganic metal salt.

5. The use of the fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants according to any one of claims 1 to 4, characterized in that: The fuel additive is applied to the combustion of coal-water slurry, specifically, the fuel additive is added to the coal-water slurry and sprayed into the coal-water slurry boiler together with the coal-water slurry.

6. The use of a fuel additive for desulfurization and denitrification in fuel combustion in a thermal power plant according to any one of claims 1 to 4, characterized in that: The fuel additive is applied to coal powder combustion or coal gasification combustion, specifically, the fuel additive is prepared into an additive aqueous solution with a mass fraction of 1%-5%, and mixed with ammonia and coal in the form of gaseous spray.

7. The use of the fuel additive for desulfurization and denitrification in fuel combustion in thermal power plants according to claim 6, characterized in that: The additive aqueous solution also includes 1%-2% by mass of a rapid dispersant and 1%-2% by mass of a rapid penetrant.

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