An in-situ acid gas removal agent, its preparation method and application

Abstract

This invention relates to an in-situ acid gas removal agent, its preparation method, and its application. The in-situ acid gas removal agent comprises a main agent, a bulking agent, a water-retaining agent, a forming agent, and water; the main agent is one or more of calcium hydroxide, calcium oxide, sodium hydroxide, sodium oxide, magnesium hydroxide, magnesium oxide, aluminum hydroxide, aluminum oxide, calcium acetate, sodium acetate, and fly ash; the bulking agent is perlite; the water-retaining agent is one or more of polysaccharides and / or water-absorbing polymers; and the forming agent is one or more of silicate cement, magnesium phosphate cement, and water glass. The in-situ acid gas removal agent of this invention has a large specific surface area due to its porous structure, good adsorption capacity for acid gases, and high deacidification activity. It can effectively fix acid gases such as sulfur dioxide and hydrogen chloride generated during the combustion of solid materials in situ, thereby reducing the volatilization of acid gases into flue gas.

Description

Technical Field

[0001] This invention relates to the field of acid removal technology for flue gas generated in calcining furnaces, and to an in-situ acid gas removal agent, its preparation method, and its application. Background Technology

[0002] Since materials such as coal and waste have calorific value, coal combustion and waste incineration are common methods of power generation. However, these materials inevitably contain elements such as sulfur and chlorine. These elements undergo combustion reactions in the incinerator, producing acidic gases such as sulfur dioxide and hydrogen chloride, which enter the flue gas. On one hand, the large amounts of sulfur dioxide and hydrogen chloride produced in the incinerator furnace are at extremely high temperatures, causing severe corrosion to the incinerator's grate and walls. On the other hand, various countries have strict requirements for incinerator flue gas emissions; the concentrations of sulfur dioxide and hydrogen chloride in the emitted flue gas cannot exceed national standards. Therefore, almost all incinerator flue gas must undergo deacidification treatment to reduce the concentration of sulfur dioxide, hydrogen chloride, and other acidic gases in the flue gas. The use of wet, semi-dry, and dry processes for flue gas desulfurization has become an essential step to ensure that the flue gas from incinerators meets emission standards. However, this process cannot solve the problem of damage to the furnace caused by high concentrations and high temperatures of sulfur dioxide and hydrogen chloride acidic gases. Furthermore, the high concentration of acidic gases in the flue gas requires a large amount of desulfurization agents, and the resulting waste is substantial and difficult to handle. For example, the fly ash obtained after desulfurization of waste incineration flue gas is hazardous waste, and fly ash disposal costs have become a significant expense for waste-to-energy plants. Chinese patent application CN113856450A discloses an alkaline material for removing acidic gases from flue gas and its preparation method. The patent application discloses that the raw materials for preparing the alkaline material contain 1-3 parts of fly ash, 0.8-1.2 parts of calcium hydroxide, 0.5-1 parts of additives, and water in a weight ratio of 10-15 times the total weight of the hydrated fly ash, calcium hydroxide, and additives. The additives are selected from one or more of sulfates or salts that hydrolyze to produce alkaline solutions. However, the alkaline material prepared by this patent application has poor adsorption performance for acidic gases such as HCl and SO2, and its deacidification efficiency is low.

[0003] Therefore, the research and development of materials for in-situ removal of acidic gases is of great value and significance, and it is very necessary to provide an in-situ acidic gas removal agent, its preparation method and application. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides an in-situ acid gas removal agent, its preparation method, and its application. The in-situ acid gas removal agent of this invention has a large specific surface area due to its porosity, exhibits good adsorption capacity for acid gases, and possesses high deacidification activity. It can effectively fix acid gases such as sulfur dioxide and hydrogen chloride generated during the combustion of solid materials in situ, thereby reducing the volatilization of acid gases into the flue gas.

[0005] The present invention provides an in-situ acid gas removal agent in a first aspect, the acid gas removal agent comprising a main agent, a bulking agent, a water-retaining agent, a forming agent, and water; the main agent is one or more of calcium hydroxide, calcium oxide, sodium hydroxide, sodium oxide, magnesium hydroxide, magnesium oxide, aluminum hydroxide, aluminum oxide, calcium acetate, sodium acetate, and fly ash; the bulking agent is perlite; the water-retaining agent is one or more of polysaccharides and / or water-absorbing polymers; and the forming agent is one or more of silicate cement, magnesium phosphate cement, and water glass.

[0006] Preferably, the mass of the leavening agent is 2-5% of the mass of the main agent; the mass of the water-retaining agent is 2-5% of the mass of the main agent; the mass of the molding agent is 2-8% of the mass of the main agent; and / or the mass of the water is 4-15% of the mass of the main agent.

[0007] Preferably, the water-retaining agent is a mixture of polysaccharides and water-absorbing polymers in a mass ratio of 1:(2-4).

[0008] Preferably, the polysaccharide is cellulose, and the water-absorbing polymer is a superabsorbent polymer.

[0009] Preferably, the mass ratio of the fluffing agent to the water-retaining agent is 1:(1.5-2.5).

[0010] Preferably, at least one dimension of the acid gas in-situ removal agent is not less than 5 mm.

[0011] The present invention provides a second aspect of a method for preparing the acidic gas in-situ removal agent described in the first aspect, the method comprising the following steps:

[0012] (1) Grind the main agent, water-retaining agent and molding agent evenly to obtain the first material;

[0013] (2) Add water to the first material and mix well, then add leavening agent and mix well to obtain the second material;

[0014] (3) The second material is added to the molding machine to form an acid gas in situ removal agent.

[0015] Preferably, the grinding time is 30 to 120 minutes.

[0016] Preferably, at least one dimension of the acid gas in-situ removal agent is not less than 5 mm.

[0017] In a third aspect, the present invention provides the application of the acid gas in-situ removal agent described in the first aspect or the acid gas in-situ removal agent prepared by the preparation method described in the second aspect of the present invention in the removal of acid gases during solid fuel combustion.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] (1) The acid gas in-situ removal agent of the present invention can be fed into the incinerator together with various solid fuels such as coal powder and garbage. During the high-temperature combustion process, the acid gas in-situ removal agent has a high acid removal activity and a large specific surface area due to its porosity. It can fix acid gases such as sulfur dioxide and hydrogen chloride generated during the combustion of solid materials in situ, thereby reducing the volatilization of acid gases into the flue gas.

[0020] (2) This invention introduces perlite, a fluffing agent, and a water-retaining agent selected from polysaccharides and / or water-absorbing polymers into an in-situ acid gas remover. This invention is the first to discover that the addition and synergistic effect of the fluffing agent and the water-retaining agent can effectively create pores, significantly increasing the specific surface area and pore structure of the in-situ acid gas remover. This results in higher efficiency and adsorption performance when adsorbing acidic gases. These pores and surface structures provide more active sites, enabling acidic gas molecules to interact more effectively with the remover, thus giving the in-situ acid gas remover excellent deacidification performance. A possible reason is that perlite contains many tiny pores and voids. When perlite is added to the remover, it facilitates the formation of a three-dimensional network structure in the remover composition, allowing gas molecules to enter and diffuse within it. This increases the pore structure and porosity of the remover, forming more adsorption sites. Simultaneously, its porous structure increases the specific surface area of ​​the remover, allowing gas molecules to adsorb onto these surfaces. A larger specific surface area means more active sites, which helps improve the remover's adsorption capacity for acidic gases. This invention also incorporates a water-retaining agent, which can further form a network structure or a gel structure in the removal agent composition. At high temperatures, the water molecules adsorbed by the water-retaining agent in the network or gel structure will dehydrate. As the temperature further increases, the water-retaining agent itself, being an organic compound, will also decompose. The dehydration and decomposition of the water-retaining agent will inevitably form new pores within the removal agent, resulting in a finer structure with richer pores and higher porosity. This significantly increases the specific surface area of ​​the removal agent during high-temperature operation, allowing acidic gas molecules to more easily penetrate and diffuse into the removal agent, effectively improving the adsorption and removal efficiency of the removal agent for acidic gases.

[0021] (3) The acid gas in-situ removal agent in this invention can reduce the concentration of acid gas in the flue gas and reduce the corrosion of the furnace by high temperature acid gas; this invention can reduce the amount of desulfurizing agent used in the traditional desulfurization system at the downstream end and reduce costs.

[0022] (4) The acid gas in-situ removal agent in this invention has at least one dimension of not less than 5 mm. The removal agent is large in size and cannot float. It will not float with the flue gas during the incineration process, will not enter the downstream process with the flue gas, and will not increase the load of the downstream flue gas filtration process. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In a first aspect, this invention provides an in-situ acid gas removal agent, comprising a main agent, a bulking agent, a water-retaining agent, a forming agent, and water; the main agent is one or more of calcium hydroxide, calcium oxide, sodium hydroxide, sodium oxide, magnesium hydroxide, magnesium oxide, aluminum hydroxide, aluminum oxide, calcium acetate, sodium acetate, and fly ash; the bulking agent is perlite; the water-retaining agent is one or more of polysaccharides and / or water-absorbing polymers; the forming agent is one or more of silicate cement, magnesium phosphate cement, and water glass; in this invention, also... The fluffing agent is referred to as the first auxiliary agent, and the water-retaining agent is referred to as the second auxiliary agent. The acid gas in-situ removal agent in this invention can be used to remove acid gases during the combustion of solid fuels. Since the combustion process of solid dyes is a high-temperature environment, in this invention, the acid gas in-situ removal agent can also be referred to as a high-temperature acid gas in-situ removal agent or a high-temperature acid gas in-situ removal agent composition. Here, "in-situ" means that the acid gas in-situ removal agent can fix the acid gases generated during the combustion process of solid materials in situ, reducing the volatilization of acid gases into the flue gas.

[0025] The acid gas in-situ removal agent of this invention can be fed into the incinerator along with various solid fuels such as pulverized coal and waste. During high-temperature combustion, due to its high deacidification activity and large specific surface area, the acid gas in-situ removal agent can effectively fix acid gases such as sulfur dioxide and hydrogen chloride generated during the combustion of solid materials, reducing the volatilization of acid gases into the flue gas. This invention introduces perlite, a loosening agent, and a water-retaining agent selected from polysaccharides and / or water-absorbing polymers into the acid gas in-situ removal agent. This invention is the first to discover that the addition and synergistic effect of the loosening agent and the water-retaining agent can effectively create pores, significantly improving the specific surface area and pore structure of the acid gas in-situ removal agent, thereby exhibiting higher efficiency and adsorption performance when adsorbing acid gases. These pores and surface structures provide more active sites, promoting more effective interaction between acid gas molecules and the removal agent, resulting in excellent deacidification performance of the acid gas in-situ removal agent. The possible reason is that perlite contains many tiny pores and gaps. When perlite is added to the remover, it helps to form a three-dimensional network structure in the remover composition, allowing gas molecules to enter and diffuse inside. This increases the pore structure and porosity of the remover, forming more adsorption sites. At the same time, its porous structure can increase the specific surface area of ​​the remover, allowing gas molecules to be adsorbed on these surfaces. A larger specific surface area means more active sites, which helps to improve the remover's adsorption capacity for acidic gases. This invention also incorporates a water-retaining agent, which can further form a network or gel structure within the desulfurizing agent composition. At high temperatures, the water molecules adsorbed by the water-retaining agent undergo dehydration. With further increases in temperature, the organic water-retaining agent itself decomposes. This dehydration and decomposition reaction inevitably creates new pores within the desulfurizing agent, resulting in a finer structure with richer pores and higher porosity. This significantly increases the specific surface area of ​​the desulfurizing agent during high-temperature operation, allowing acidic gas molecules to more easily penetrate and diffuse into the agent, effectively improving its adsorption and removal efficiency. The in-situ acid gas desulfurizing agent of this invention can reduce the concentration of acidic gases in combustion flue gas and reduce the corrosion of the furnace by high-temperature acidic gases. This invention can also reduce the amount of desulfurizing agent used in traditional downstream desulfurization systems, thus lowering costs.

[0026] According to some preferred embodiments, the mass of the leavening agent is 2-5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%) of the mass of the main agent; the mass of the water-retaining agent is 2-5% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%) of the mass of the main agent; the mass of the forming agent is 2-8% (e.g., 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, or 8%) of the mass of the main agent; and / or the mass of the water is 4-15% (e.g., 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%) of the mass of the main agent.

[0027] According to some specific embodiments, the acidic gas in-situ removal agent includes a main agent, a bulking agent, a water-retaining agent, a molding agent, and water, wherein the bulking agent is 2wt% to 5wt% of the main agent, the water-retaining agent is 2wt% to 5wt% of the main agent, the molding agent is 2wt% to 8wt% of the main agent, and water is 4wt% to 15wt% of the main agent; wherein the main agent is one or a mixture of more than one of calcium hydroxide, calcium oxide, sodium hydroxide, sodium oxide, magnesium hydroxide, magnesium oxide, aluminum hydroxide, aluminum oxide, calcium acetate, sodium acetate, and fly ash; the bulking agent is perlite; the water-retaining agent is one or a mixture of more than one of cellulose, polysaccharides, and water-absorbing polymers; and the molding agent is one or a mixture of more than one of silicate cement, magnesium phosphate cement, and water glass; in this invention, the silicate cement is, for example, ordinary silicate cement 32.5 or ordinary silicate cement 42.5, which are commercially available products.

[0028] According to some preferred embodiments, the water-retaining agent is composed of polysaccharides and water-absorbing polymers in a mass ratio of 1:(2-4) (e.g., 1:2, 1:2.5, 1:3, 1:3.5, or 1:4). This invention has found that the use of polysaccharides and water-absorbing polymers in a suitable ratio can synergistically optimize the structure and performance of the remover, thereby further improving its adsorption capacity for acidic gases and its deacidification effect. Preferably, this invention introduces suitable polysaccharide molecules into the water-absorbing polymer. This invention has found that polysaccharide molecules have a unique spatial configuration, enabling them to form complex spatial network structures in the composition. This optimizes the remover's dehydration and decomposition reactions during high-temperature service, resulting in a more diverse pore structure and increased specific surface area. This provides more surface reaction areas for the adsorption of acidic gas molecules.

[0029] According to some preferred embodiments, the polysaccharide is cellulose, and the water-absorbing polymer is a superabsorbent polymer (i.e., a superabsorbent resin). In this invention, the superabsorbent polymer is, for example, polyacrylamide superabsorbent resin and / or cellulose-grafted acrylic superabsorbent resin. This invention does not specifically limit the perlite, cellulose, polyacrylamide superabsorbent resin, and cellulose-grafted acrylic superabsorbent resin used; they can be products that can be directly purchased on the market or products synthesized by existing methods.

[0030] According to some preferred embodiments, the mass ratio of the leavening agent to the water-retaining agent is 1:(1.5-2.5) (e.g., 1:1.5, 1:2, or 1:2.5). This invention has found that controlling the appropriate mass ratio of the leavening agent to the water-retaining agent can better optimize the pore structure of the remover and facilitate the synergistic construction of a complex and advantageous pore system. This invention has also found that effectively controlling the ratio of the leavening agent to the water-retaining agent can prevent excessive use of the water-retaining agent from leading to an overly dense network structure, thereby limiting the increase in specific surface area. An appropriate ratio can ensure that the formation of an optimized network structure is beneficial for increasing the specific surface area without excessively affecting the pore structure, thus ensuring the provision of more active sites and enhancing the adsorption capacity of the remover for acidic gases. If the mass ratio of the leavening agent to the water-retaining agent is inappropriate, it will affect the effective improvement of the pore structure and specific surface area of ​​the remover.

[0031] According to some preferred embodiments, the acid gas in-situ removal agent has at least one dimension of not less than 5 mm. In this way, the removal agent is large in size and cannot float. It will not float with the flue gas during the incineration process, will not enter the downstream process with the flue gas, and will not increase the load on the downstream flue gas filtration process.

[0032] The present invention provides a second aspect of a method for preparing the acidic gas in-situ removal agent described in the first aspect, the method comprising the following steps:

[0033] (1) Grind the main agent, water-retaining agent and molding agent evenly to obtain the first material;

[0034] (2) Add water to the first material and mix well, then add leavening agent and mix well to obtain the second material;

[0035] (3) The second material is added to the molding machine to form an acid gas in situ removal agent; the present invention does not limit the specific molding conditions, and those skilled in the art can choose conventionally; specifically, for example, the second material is fed into the molding machine for molding processing to obtain a shape with at least one dimension not less than 5mm, that is, the acid gas in situ removal agent is obtained.

[0036] According to some preferred embodiments, the grinding time is 30 to 120 minutes (e.g., 30, 40, 50, 60, 70, 80, 90, 100, 110 or 120 minutes).

[0037] According to some preferred embodiments, at least one dimension of the acid gas in-situ removal agent is not less than 5 mm.

[0038] According to some specific embodiments, the preparation of the acidic gas in-situ removal agent includes the following steps:

[0039] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 30 to 120 minutes, mix evenly, and obtain the first material.

[0040] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0041] ③ The second material is fed into the molding machine for molding to obtain a shape with at least one dimension not less than 5mm, which is the acid gas in-situ removal agent.

[0042] In a third aspect, the present invention provides the application of the acid gas in-situ removal agent described in the first aspect or the acid gas in-situ removal agent prepared by the preparation method described in the second aspect of the present invention in the removal of acid gases during solid fuel combustion.

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, all raw materials used in the embodiments of the present invention and comparative examples can be obtained commercially or synthesized by existing methods.

[0044] Example 1

[0045] This embodiment provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, cellulose as a water-retaining agent, silicate cement (Silicate cement 32.5) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the water-retaining agent is 4% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0046] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0047] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0048] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0049] ③ The second material is fed into the molding machine for molding to obtain an acid gas in-situ removal agent. The obtained acid gas in-situ removal agent is in the form of a column with an average height of 15 mm and an average diameter of 5 mm.

[0050] Example 2

[0051] This embodiment provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, superabsorbent polymer (polyacrylamide superabsorbent resin) as a water-retaining agent, silicate cement (silicate cement 32.5) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the water-retaining agent is 4% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0052] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0053] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0054] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0055] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0056] Example 3

[0057] This embodiment provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, a water-retaining agent, silicate cement (32.5 silicate cement) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the water-retaining agent is 4% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; the mass of the water is 10% of the mass of the main agent; the water-retaining agent is composed of cellulose and polyacrylamide superabsorbent resin mixed in a mass ratio of 1:3.

[0058] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0059] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0060] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0061] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0062] Example 4

[0063] This embodiment provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, superabsorbent polymer (polyacrylamide superabsorbent resin) as a water-retaining agent, silicate cement (silicate cement 32.5) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the water-retaining agent is 2% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0064] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0065] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0066] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0067] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0068] Example 5

[0069] This embodiment provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, superabsorbent polymer (polyacrylamide superabsorbent resin) as a water-retaining agent, silicate cement (silicate cement 32.5) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the water-retaining agent is 6% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0070] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0071] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0072] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0073] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0074] Comparative Example 1

[0075] This comparative example provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, superabsorbent polymer (polyacrylamide superabsorbent resin) as the water-retaining agent, silicate cement (silicate cement 32.5) as the molding agent, and water. The mass of the water-retaining agent is 4% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0076] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0077] ① Grind the main agent, water-retaining agent and molding agent thoroughly for 60 minutes, mix evenly, and obtain the first material.

[0078] ② Add water to the first material and mix thoroughly to obtain the second material.

[0079] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0080] Comparative Example 2

[0081] This comparative example provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, perlite as a bulking agent, silicate cement (Silicate cement 32.5) as a molding agent, and water. The mass of the bulking agent is 2% of the mass of the main agent; the mass of the molding agent is 4% of the mass of the main agent; and the mass of water is 10% of the mass of the main agent.

[0082] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0083] ① Grind the main agent and molding agent thoroughly for 60 minutes, mix them evenly, and obtain the first material.

[0084] ② Add water to the first material and mix thoroughly. Then add a leavening agent and stir until the mixture is evenly mixed to obtain the second material.

[0085] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0086] Comparative Example 3

[0087] This comparative example provides an in-situ acid gas removal agent and its preparation method. The in-situ acid gas removal agent is composed of calcium hydroxide as the main agent, silicate cement (Silicate Cement 32.5) as the molding agent, and water. The mass of the molding agent is 4% of the mass of the main agent, and the mass of the water is 10% of the mass of the main agent.

[0088] The preparation of the acidic gas in-situ removal agent includes the following steps:

[0089] ① Grind the main agent and molding agent thoroughly for 60 minutes, mix them evenly, and obtain the first material.

[0090] ② Add water to the first material and mix thoroughly to obtain the second material.

[0091] ③ The second material is fed into the molding machine for molding to obtain an acid gas in situ removal agent. The obtained acid gas in situ removal agent is in the form of a disc with an average thickness of 1 mm and an average diameter of 20 mm.

[0092] Comparative Example 4

[0093] ① Weigh 72g of F-type fly ash (initial particle size 150 mesh), 24g of calcium hydroxide, and 24g of CaSO4 and add them to a 2L three-necked flask, then add 1200mL of water for hydration.

[0094] ② Place the three-necked flask in a heat-collecting constant temperature magnetic stirrer and start the stirring (250r / min) and heating functions. After hydration at 80℃ for 8 hours, filter the slurry in the container. Place the resulting deacidifying agent filter cake in a drying oven and dry it at 100℃ until constant weight.

[0095] ③ The dried deacidifying agent filter cake is put into a pulverizer and pulverized to obtain powder with a certain particle size (150 mesh), and then bagged for later use;

[0096] ④ Weigh 120g of powdered deacidifying agent and place it in a clean mortar. Add 60g of binder (water) and knead manually. Put the kneaded deacidifying agent powder into a single screw extruder for extrusion. At the same time, cut the extruded strip material to obtain deacidifying agent particles with a diameter and length of about 3-5mm.

[0097] ⑤ Place the above deacidifying agent granules in a drying oven and dry them at 100°C until constant weight. Then pack them into bags for later use to obtain a highly active granular deacidifying agent.

[0098] This invention tested the adsorption performance of the acid gas in-situ removal agents obtained in Examples 1-5 and Comparative Examples 1-3, as well as the highly active particulate deacidifying agent obtained in Comparative Example 4. The results are shown in Table 1. The adsorption performance was tested as follows: 20g of sample was placed in a fixed bed, heated to 500°C, and 100L of simulated multi-component acid gas (HCl-1000ppm, SO2-500ppm) was introduced. The concentrations of HCl and SO2 in the gas at the outlet of the fixed bed were measured.

[0099] Table 1

[0100]

[0101]

[0102] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0103] Finally, it should be noted that: the above description details the high-temperature acidic gas in-situ removal agent, preparation method, and application disclosed in the embodiments of the present invention. Specific examples have been used to illustrate the implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ acid gas removal agent, characterized in that: The acid gas in-situ removal agent comprises a main agent, a leavening agent, a water-retaining agent, a forming agent, and water; The main agent is calcium hydroxide; The bulking agent is perlite; The water-retaining agent is composed of polysaccharide and water-absorbing polymer in a mass ratio of 1:(2~4); the polysaccharide is cellulose, and the water-absorbing polymer is polyacrylamide superabsorbent resin; The molding agent is one or more of silicate cement, magnesium phosphate cement, and water glass; The mass of the leavening agent is 2-5% of the mass of the main agent; The mass of the water-retaining agent is 2-5% of the mass of the main agent; The mass of the molding agent is 2-8% of the mass of the main agent; The mass of the water is 4-15% of the mass of the main agent; The mass ratio of the leavening agent to the water-retaining agent is 1:(1.5~2.5). The acid gas in-situ removal agent has at least one dimension of not less than 5 mm; The acid gas in-situ removal agent fixes sulfur dioxide and hydrogen chloride acid gases generated during solid fuel combustion in situ, reducing the volatilization of acid gases into the flue gas.

2. The method for producing an acid gas in-situ removal agent according to claim 1, characterized by, The method includes the following steps: (1) Grind the main agent, water-retaining agent and molding agent evenly to obtain the first material; (2) Add water to the first material and mix well, then add leavening agent and mix well to obtain the second material; (3) The second material is added to the molding machine to form an acid gas in situ removal agent; at least one dimension of the acid gas in situ removal agent is not less than 5 mm.

3. The preparation method according to claim 2, characterized in that: The grinding time is 30~120 minutes.

4. The application of an in-situ acid gas removal agent in the removal of acid gases during solid fuel combustion, characterized in that, The acid gas in-situ removal agent is the acid gas in-situ removal agent according to claim 1, or the acid gas in-situ removal agent is the acid gas in-situ removal agent prepared by the preparation method according to claim 2 or 3; The acid gas in-situ removal agent fixes sulfur dioxide and hydrogen chloride acid gases generated during solid fuel combustion in situ, reducing the volatilization of acid gases into the flue gas.

Images