Catalyst for removing carbon monoxide in industrial flue gas and preparation method thereof

Abstract

The invention relates to a catalyst for removing carbon monoxide in industrial flue gas and a preparation method thereof. The catalyst is of a multi-layer composite structure and serves as an inner core and a shell, iron and copper active components and auxiliaries are inlaid in the inner core, and the auxiliaries comprise one or more of manganese, cerium, cobalt, zinc and the like; the molar ratio of the inner core to the active component to the assistant is less than or equal to 1: 1 The molar ratio of the iron to the copper to the auxiliary agent is 1: (0.3-0.5): (0-0.2). The CO conversion rate of the catalyst is kept at 95% or above, and the catalyst is stable in performance, good in water resistance and sulfur resistance, simple in preparation method, low in cost and good in stability.

Description

Technical Field

[0001] This invention relates to the field of air pollution control technology in the energy conservation and environmental protection industry, specifically to a catalyst for removing carbon monoxide from industrial flue gas and its preparation method. Background Technology

[0002] Carbon monoxide (CO) seriously endangers human health and is one of the six basic pollutants controlled in my country's "Ambient Air Quality Standards". In terms of CO control technologies, CO emission reduction technologies can be divided into three directions: source control, process reduction, and end-of-pipe treatment. Source control mainly focuses on the fuel energy structure, reducing the use of high-carbon fossil fuels, such as using environmentally friendly hydrogen and electricity. Process reduction mainly optimizes fuel combustion conditions to promote complete CO combustion, thereby reducing emissions. End-of-pipe treatment is the ultimate approach to CO control, with treatment routes mainly including CO absorption, strong oxidant oxidation, and catalytic oxidation. While source control can effectively control CO emissions, it requires the construction of new equipment and plants, resulting in huge investments. Process reduction measures have limited CO reduction effects, and some technologies will generate secondary pollution. Catalytic oxidation, a key end-of-pipe treatment technology, can achieve CO emission reductions of over 90% without increasing operating energy consumption or generating secondary pollution.

[0003] Catalysts used for CO catalytic oxidation mainly include noble metal catalysts and non-noble metal oxide catalysts. Noble metal catalysts include Au, Pt, Pd, Rh, and Ag, most of which are supported catalysts, resulting in high cost and sintering issues, limiting their large-scale application in CO removal from stationary flue gas. Non-noble metal oxide catalysts, such as Mn-based, Co-based, Ce-based, and Cu-based catalysts, are prone to deactivation due to the high concentrations of water vapor and SO2 in industrial flue gas. Therefore, the preparation of non-noble metal catalysts with good water and sulfur resistance, low cost, and good stability is of great significance for CO removal from stationary flue gas. Summary of the Invention

[0004] This invention provides a catalyst for removing carbon monoxide from industrial flue gas and its preparation method. A metal oxide catalyst with a multilayer composite structure is prepared using common raw materials. It exhibits high activity and water and sulfur resistance during the CO oxidation and removal process.

[0005] In a first aspect, the present invention relates to a catalyst for removing carbon monoxide from industrial flue gas, the catalyst having a multilayer composite structure, so as to... As the kernel, the outer shell is The core is embedded with iron and copper active components and additives, wherein the additives include one or more of manganese, cerium, cobalt, zinc, etc. The molar ratio of the core, active ingredient, and auxiliaries is ≤1:1.

[0006] Preferably, the molar ratio of iron:copper:additive is 1:(0.3~0.5):(0~0.2).

[0007] Preferably, the catalyst uses soluble sulfate as the active component and auxiliary material, barium hydroxide and soluble carbonate and bicarbonate as precipitants, and dilute nitric acid and organic acid as etching agents; tetrabutyl titanate is used as the titanium source, and ammonia is used as the pH adjuster. By controlling the pH value of the solution, a catalyst precursor is obtained, and the catalyst precursor is activated and calcined to obtain a catalyst with a multilayer composite structure.

[0008] Preferably, the catalyst is used at a flue gas temperature of 230°C and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation.

[0009] Secondly, the present invention relates to a method for preparing a catalyst for removing carbon monoxide from industrial flue gas, comprising the following steps:

[0010] (1) Weigh out the soluble sulfates of the active component and the auxiliary agent respectively, and add them to deionized water at 40-80℃ and stir until completely dissolved to make solution A;

[0011] (2) Crush barium hydroxide into powder at x times the number of moles of sulfate in solution A and use it as reagent B, where 0 ≤ x ≤ 1;

[0012] (3) Prepare solution C by mixing nitric acid with an equimolar amount of organic acid and stirring until homogeneous, wherein the sum of the molar amounts of nitric acid and inorganic acid is y times the molar amount of sulfate, and y <x;

[0013] (4) Add z times the number of the sulfate moles of the soluble carbonate or bicarbonate to deionized water at 40-80℃ and stir until completely dissolved to form solution D, where z = 1-x+y;

[0014] (5) Add a certain amount of tetrabutyl titanate to anhydrous ethanol and stir until completely dissolved to form solution E. The molar ratio of tetrabutyl titanate to anhydrous ethanol is 1:(4~9), and the molar ratio of Ti to sulfate is 0.1~1.

[0015] (6) Add reagent B and solution C to solution A simultaneously under vigorous stirring. Adjust the addition rate of both to ensure that they are added at a uniform rate. After complete addition, continue stirring for 5-10 minutes to obtain suspension S1.

[0016] (7) Add solution D to suspension S1 with thorough stirring, continue stirring for 10-60 minutes, and adjust its pH to between 7 and 10 with ammonia water to obtain suspension S2;

[0017] (8) Add solution E to suspension S2 while stirring thoroughly, and continue stirring for 30-600 minutes after the addition is complete to obtain suspension S3;

[0018] (9) Filter the suspension S3 and wash it until the filtrate is neutral. Dry it at 100-150℃ to constant weight to obtain the catalyst precursor.

[0019] (10) Add molding aid to the catalyst precursor to form it. The formed catalyst precursor is activated and calcined in a mixed atmosphere of air and nitrogen to obtain the desired catalyst. The oxygen content in the mixed atmosphere is 2-20%, the calcination temperature is 300-550℃, and the calcination time is 2-24 hours.

[0020] Preferably, the organic acid in step (3) is one or a mixture of several of acetic acid, lactic acid or citric acid.

[0021] Preferably, the soluble carbonate or bicarbonate in step (4) includes one or a mixture of several of the following: ammonium carbonate, sodium carbonate, potassium carbonate, ammonium bicarbonate, sodium bicarbonate, and potassium bicarbonate.

[0022] Preferably, the pH value in step (7) is controlled between 7 and 8.

[0023] Preferably, the stirring time in step (8) is 30-180 minutes.

[0024] Preferably, the roasting temperature in step (10) is 350℃-400℃ and the roasting time is 4-10h.

[0025] The beneficial effects of this invention are as follows:

[0026] The catalyst of this invention uses soluble sulfate as a raw material, barium hydroxide and soluble carbonates and bicarbonates as precipitants, and dilute nitric acid and organic acids as etching agents. A non-noble metal catalyst with a multilayer composite structure was prepared for the shell layer. The core of the catalyst is... Primarily composed of Fe, Cu, and other additives embedded in the surface and channels of barium sulfate as hydroxide and carbonate centers, these centers form active oxide centers after activation and calcination, resulting in a large specific surface area (up to [missing information - likely a number]). This prevents the catalyst from degrading due to the sintering and agglomeration of active centers caused by the large amount of heat released during CO removal, thus extending the catalyst life.

[0027] The catalyst of this invention has a layer precipitated outside the active component. A unique porous structure can be formed through a subsequent specific activation and calcination process, and this porous structure is similar to... The core and active ingredients work together to significantly reduce water vapor and other harmful substances while ensuring catalytic efficacy. Adsorption and oxidation at the active sites reduce sulfate formation, thus improving the catalyst's water and sulfur resistance. The catalyst's... The core can also reduce water vapor and The adsorption of the catalyst reduces the deactivation rate of active centers dispersed on its surface and within its pores, thereby reducing the cost of catalyst preparation.

[0028] The catalyst of this invention operates at a flue gas temperature of 230°C and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation, demonstrating good water and sulfur resistance. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the granular catalyst prepared for the example.

[0031] Figure 2 This is a scanning electron microscope image of the catalyst after calcination in Example 3.

[0032] Figure 3 The graph shows the performance data of the catalysts prepared in Example 3 and Comparative Examples 1-2. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0034] To address the technical problems of low water and sulfur resistance and high cost of existing catalysts, this invention provides a catalyst for removing carbon monoxide from industrial flue gas and its preparation method, which overcomes the problems of high preparation cost of precious metal catalysts and poor stability of transition metal catalysts. It is suitable for the treatment of flue gas from coking, steel, cement, and industrial kilns.

[0035] To address the aforementioned technical problems, embodiments of the present invention provide a catalyst for removing carbon monoxide from industrial flue gas. This catalyst has a multi-layered composite structure. As the kernel, the outer shell is The core is embedded with iron and copper active components and additives, wherein the additives include one or more of manganese, cerium, cobalt, zinc, etc. The molar ratio of the core, active ingredient, and auxiliaries is ≤1:1.

[0036] In one embodiment, the molar ratio of iron:copper:additive is 1:(0.3~0.5):(0~0.2).

[0037] In one embodiment, the catalyst uses soluble sulfate as the active component and auxiliary material, barium hydroxide and soluble carbonate and bicarbonate as precipitants, and dilute nitric acid and organic acid as etching agents; tetrabutyl titanate is used as the titanium source, and ammonia is used as the pH adjuster. By controlling the pH value of the solution, a catalyst precursor is obtained, and the catalyst precursor is activated and calcined to obtain a catalyst with a multilayer composite structure.

[0038] In one embodiment, the catalyst is used at a flue gas temperature of 230°C and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation.

[0039] A method for preparing a catalyst for removing carbon monoxide from industrial flue gas according to an embodiment of the present invention includes the following steps:

[0040] (1) Weigh out the soluble sulfates of the active component and the auxiliary agent respectively, and add them to deionized water at 40-80℃ and stir until completely dissolved to make solution A;

[0041] (2) Crush barium hydroxide into powder at x times the number of moles of sulfate in solution A and use it as reagent B, where 0≤x≤1; to accelerate the dissolution rate of barium hydroxide, it can be pulverized and powder that passes through a 200-mesh sieve can be used.

[0042] (3) Prepare solution C by mixing nitric acid with an equimolar amount of organic acid and stirring until homogeneous, wherein the sum of the molar amounts of nitric acid and inorganic acid is y times the molar amount of sulfate, and y <x。

[0043] (4) Add z times the number of the sulfate moles of the soluble carbonate or bicarbonate to deionized water at 40-80℃ and stir until completely dissolved to form solution D, where z = 1-x+y;

[0044] (5) Add a certain amount of tetrabutyl titanate to anhydrous ethanol and stir until completely dissolved to form solution E. The molar ratio of tetrabutyl titanate to anhydrous ethanol is 1:(4-9), and the molar ratio of Ti to sulfate is 0.1~1.

[0045] (6) Add reagent B and solution C to solution A simultaneously under vigorous stirring. Adjust the addition rate of both to ensure that they are added at a uniform rate. After complete addition, continue stirring for 5-10 minutes to obtain suspension S1.

[0046] Solution C can accelerate the dissolution of barium hydroxide and promote... Reaction with sulfate ions; dissolution of some active metal and auxiliary hydroxides, thereby creating pores on the barium sulfate precipitate; the anions of organic acids can form complexes with metals, promoting... It reacts with sulfate ions, reduces the reaction between metal salts and hydroxide ions, and the residual organic groups have the function of creating pores and promoting the uniform distribution of metal active centers.

[0047] Suspension S1 simultaneously generates precipitates of barium sulfate and metal hydroxides such as copper and iron. Meanwhile, nitric acid and organic acids in solution C dissolve the metal hydroxides, making the precipitate mainly composed of barium sulfate. This process is the etching process, in which the acid reacts with the hydroxides to fully expose the barium sulfate and the internal metal hydroxides.

[0048] (7) Add solution D to suspension S1 with thorough stirring, continue stirring for 10-60 minutes, and adjust its pH to between 7 and 10 with ammonia water to obtain suspension S2.

[0049] By stirring, unreacted metal ions react with carbonates to form metal carbonate precipitates on the surface and in the pores of barium sulfate. Adjusting the solution to alkaline conditions promotes complete precipitation and facilitates the hydrolysis of tetrabutyl titanate in the next step.

[0050] (8) Add solution E to suspension S2 while stirring thoroughly, and continue stirring for 30-600 minutes after the addition is complete to obtain suspension S3;

[0051] Tetrabutyl titanate hydrolyzes and deposits on the surface of metal carbonate. precursor (Hydrated titanium dioxide), alkaline conditions are conducive to reducing hydrolysis time.

[0052] (9) Filter the suspension S3 and wash it until the filtrate is neutral. Dry it at 100-150℃ to constant weight to obtain the catalyst precursor.

[0053] (10) Add molding aid to the catalyst precursor to form it. The formed catalyst precursor is activated and calcined in a mixed atmosphere of air and nitrogen to obtain the desired catalyst. The oxygen content in the mixed atmosphere is 2-20%, the calcination temperature is 300-550℃, and the calcination time is 2-24 hours.

[0054] The catalyst precursor is shaped by adding a molding aid, and the shape can be granular, honeycomb, plate-shaped, or coated catalyst, which can be adapted to the application scenario of CO removal catalyst.

[0055] The calcination temperature can be further optimized to 350℃-400℃, and the calcination time can be further optimized to 4-10h. During the activation process, the metal hydroxides and carbonates inside the catalyst decompose with increasing temperature and calcination time, while the surface... The precursor also decomposes and forms anatase structure as the temperature increases. Excessively high temperatures and excessively long calcination times can cause active oxides to agglomerate, sinter, and... Changes in crystal form cannot create a unique porous structure, thus making it impossible to achieve a porous structure that is compatible with... The effective combination of the core and active ingredients ensures catalytic efficacy while significantly reducing water vapor and... Adsorption and oxidation at the active sites reduce sulfate formation, thus decreasing catalyst performance.

[0056] The oxygen in the mixed atmosphere is used to provide oxygen atoms to variable-valence metals such as iron, manganese, cerium, and cobalt, so that they can form higher valence states.

[0057] In one embodiment, the organic acid in step (3) is one or a mixture of several of acetic acid, lactic acid, or citric acid.

[0058] In one embodiment, the soluble carbonate or bicarbonate in step (4) includes one or a mixture of several of the following: ammonium carbonate, sodium carbonate, potassium carbonate, ammonium bicarbonate, sodium bicarbonate, and potassium bicarbonate.

[0059] In one embodiment, the pH value in step (7) is controlled between 7 and 8.

[0060] In one embodiment, the stirring time in step (8) is 30-180 minutes.

[0061] The catalyst obtained through the above preparation process has a multilayer composite structure. As the kernel, the outer shell is The core is embedded with iron and copper active components and additives, wherein the additives include one or more of manganese, cerium, cobalt, zinc, etc. The molar ratio of the core, active component, and additives is ≤1:1, and the molar ratio of iron:copper:additives is 1:(0.3~0.5):(0~0.2). This ensures that the catalyst operates at a flue gas temperature of 230℃ and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation.

[0062] The embodiments of the present invention are described in detail below.

[0063] Example 1:

[0064] Catalyst preparation: Weigh 1 mol of ferrous sulfate and 0.3 mol of copper sulfate, add them to 500 mL of deionized water at 60 °C, and stir until completely dissolved. This is solution A. Crush 1.3 mol of barium hydroxide into powder and prepare reagent B. Dissolve 0.3 mol of acetic acid in 300 mL of 1 mol / L nitric acid solution and prepare solution C. Add 0.3 mol of ammonium carbonate to deionized water at 40 °C and stir until completely dissolved. This is solution D. Weigh 0.5 mol of tetrabutyl titanate and add it to 4 mol of anhydrous ethanol, stirring until completely dissolved. Dissolve the reagents and set aside as solution E. Add reagent B and solution C to solution A simultaneously with vigorous stirring. After complete addition, continue stirring for 10 minutes to obtain suspension S1. Add solution D to suspension S1 with thorough stirring and stir for 30 minutes. Adjust the pH to 7-8 using ammonia water to obtain suspension S2. Add solution E to suspension S2 with thorough stirring and continue stirring for 600 minutes after complete addition to obtain suspension S3. Filter suspension S3 and wash until the filtrate is neutral. Dry at 100-150℃ to constant weight to obtain the catalyst precursor, which is then shaped using a molding aid. The shaped catalyst precursor is denoted as Cat0.

[0065] Cat0 was calcined in a mixed atmosphere of air and nitrogen with an oxygen content of 5% at calcination temperatures of 270℃, 350℃, 400℃, 550℃, and 600℃ for 10 hours to obtain catalysts Cat-B1, Cat-T1, Cat-T2, Cat-T3, and Cat-B2, among which Cat-B1 and Cat-B2 were comparative examples.

[0066] The morphology of the catalyst after calcination is as follows Figure 1As shown, the above catalyst was crushed and sieved to obtain 40-60 mesh particles. 2g was taken for performance evaluation, and the CO conversion rate after 12 hours of stable performance was compared. The evaluation conditions were: flue gas temperature 230℃ and CO concentration... Water vapor concentration is airspeed is The results are shown in Table 1. Comparing Cat-T1, Cat-T2, and Cat-T3, the highest CO conversion rate was achieved when the catalyst was stabilized at a calcination temperature of 400℃. However, Cat-B1 and Cat-B2, due to changes in the calcination temperature, resulted in excessively low surface temperatures. The precursor cannot form anatase structure The internal metal carbonates and hydroxides do not decompose completely, failing to form a unique porous structure, thus preventing the achievement of a porous structure with... Effective coordination of the core and active components, or excessively high temperatures causing changes in the metal valence state, agglomeration, and sintering of the metal active centers inside the catalyst as the temperature rises, can lead to a decline in catalyst performance.

[0067] Table 1 Performance data of the catalyst in Example 1

[0068]

[0069] Example 2:

[0070] The Cat0 from Example 1 was calcined in a mixed atmosphere of air and nitrogen with an oxygen content of 5% at a calcination temperature of 400°C and calcination times of 1h, 3h, 5h, 10h, 15h, and 29h to obtain catalysts Cat-b1, Cat-t1, Cat-t2, Cat-t3, Cat-t4, and Cat-b2, wherein Cat-b1 and Cat-b2 are comparative examples.

[0071] The catalyst was crushed and sieved to obtain 40-60 mesh particles. 2g was taken for performance evaluation, and the CO conversion rate after 12 hours of stable performance was compared. Evaluation conditions were: flue gas temperature 230℃ and CO concentration... Water vapor concentration is airspeed is The results are shown in Table 2. The highest CO conversion rate was achieved when the catalyst was stabilized at a calcination time of 5 hours. However, Cat-b1 and Cat-b2 altered the calcination time, leading to changes in the catalyst surface... Incomplete decomposition of precursors and internal metal hydroxides and carbonates, or excessively long calcination times causing changes in metal valence states, agglomeration of active centers, and sintering, can lead to a decline in catalyst performance.

[0072] Table 2 Performance data of the catalyst in Example 2

[0073]

[0074] Combining Tables 1 and 2, the specific surface area can reflect the catalyst activity to a certain extent, but the two are not positively correlated. The calcination temperature and calcination time also have a significant impact on the catalyst conversion rate. It is speculated that the specific surface area can only represent the size of the contact area between the reactants and the catalyst, while the calcination temperature and time have a significant impact on the valence state of the metal active centers, particle size, and microstructure.

[0075] Example 3:

[0076] Weigh out 1 mol of ferrous sulfate, 0.35 mol of copper sulfate, 0.05 mol of cobalt sulfate, and 0.1 mol of manganese sulfate, then add them to 500 mL of deionized water at 60 °C and stir until completely dissolved. This is solution A. Crush 1.3 mol of barium hydroxide into powder and use it as reagent B. Dissolve 0.3 mol of citric acid in 300 mL of 1 mol / L nitric acid solution and use it as solution C. Add 0.5 mol of ammonium carbonate to deionized water at 40 °C and stir until completely dissolved. This is solution D. Weigh out 0.5 mol of tetrabutyl titanate and add it to 4 mol of anhydrous... In ethanol, the solution was stirred until completely dissolved, and this solution was prepared as E. Under vigorous stirring, reagent B and solution C were simultaneously added to solution A. After complete addition, stirring was continued for 10 minutes to obtain suspension S1. Under thorough stirring, solution D was added to suspension S1, and stirring was continued for 30 minutes. The pH was adjusted to a stable level of 7-8 using ammonia water to obtain suspension S2. Under thorough stirring, solution E was added to S2, and stirring was continued for 300 minutes after complete addition to obtain suspension S3. Suspension S3 was filtered and washed until the filtrate was neutral. It was then dried at 100-150℃ to constant weight to obtain the catalyst precursor, which was then extruded using a molding aid. The shaped catalyst precursor was calcined in a mixed atmosphere of air and nitrogen with an oxygen content of 7% at 450℃ for 6 hours to obtain the final usable catalyst Cat1. Cat1 was crushed and sieved to obtain 40-60 mesh particles. 2g was taken for evaluation. The microstructure of the catalyst is as follows: Figure 2 As shown.

[0077] Cat1 was subjected to a flue gas temperature of 230℃ and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is The evaluation was conducted over 100 hours under flue gas conditions.

[0078] Comparative Example 1:

[0079] Catalyst preparation: 1 mol of ferrous sulfate, 0.35 mol of copper sulfate, 0.05 mol of cobalt sulfate, and 0.1 mol of manganese sulfate were weighed and added to 500 mL of deionized water at 60 °C. The mixture was stirred until completely dissolved and prepared as solution A. 1.5 mol of ammonium carbonate was added to deionized water at 40 °C and stirred until completely dissolved and prepared as solution B. 0.5 mol of tetrabutyl titanate was weighed and added to 4 mol of anhydrous ethanol. The mixture was stirred until completely dissolved and prepared as solution C. Solvent B was added to solution A under vigorous stirring. After complete addition, stirring was continued for 10 minutes. The pH was adjusted to between 7 and 8 using ammonia water to obtain suspension S1. Solution C was added to S1 under thorough stirring. After complete addition, stirring was continued for 300 minutes to obtain suspension S2. Suspension S2 was filtered and washed until the filtrate was neutral. It was dried at 100-150 °C to constant weight to obtain the catalyst precursor, which was then shaped using a molding aid. The shaped catalyst precursor was calcined in a mixed atmosphere of air and nitrogen with an oxygen content of 7% at a calcination temperature of 450℃ for 6 hours to obtain the final usable catalyst Cat2. Cat2 was crushed and sieved to obtain 40-60 mesh particles, and 2g was taken for evaluation.

[0080] Cat2 was subjected to a flue gas temperature of 230℃ and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is The evaluation was conducted over 100 hours under flue gas conditions.

[0081] Comparative Example 2:

[0082] Catalyst preparation: Weigh 1 mol of ferrous sulfate, 0.35 mol of copper sulfate, 0.05 mol of cobalt sulfate, and 0.1 mol of manganese sulfate, then add them to 500 mL of deionized water at 60 °C and stir until completely dissolved. This is solution A. Crush 1.3 mol of barium hydroxide into powder. This is reagent B. Dissolve 0.3 mol of citric acid in 300 mL of 1 mol / L nitric acid solution. This is solution C. Add 0.5 mol of ammonium carbonate to 40 °C... The solution was stirred until completely dissolved in deionized water and prepared as solution D. Under vigorous stirring, reagent B and solution C were simultaneously added to solution A. After complete addition, stirring was continued for 10 minutes to obtain suspension S1. Solution D was added to suspension S1 under thorough stirring and stirred for 30 minutes. The pH was adjusted to a stable level of 7-8 using ammonia water to obtain suspension S2. Suspension S2 was filtered and washed until the filtrate was neutral. It was then dried at 100-150℃ to constant weight to obtain the catalyst precursor, which was then shaped using a molding aid. The shaped catalyst precursor was calcined in a mixed atmosphere of air and nitrogen with an oxygen content of 7% at 450℃ for 6 hours to obtain the final usable catalyst Cat3. Cat3 was crushed and sieved to obtain 40-60 mesh particles, and 2g was used for evaluation.

[0083] Cat3 was subjected to a flue gas temperature of 230℃ and a CO concentration of [missing information]. , concentration Water vapor concentration is airspeed is The evaluation was conducted over 100 hours under flue gas conditions.

[0084] Comparing Example 3 with Comparative Examples 1-2, it can be found that Cat1 is an example of the preparation method described in this application, while Cat2 is an example without the method described in this application. As a comparison method for kernel timing, Cat3 is used without kernel timing. As a comparison method when used as a shell. For example Figure 3 As shown, under the evaluation conditions, Cat1 exhibited the most stable performance among the three, Cat2 had the highest initial CO conversion rate but experienced faster deactivation, and Cat3 had the lowest initial performance but better stability than Cat2. The performance comparison of the three demonstrates that the catalyst prepared by the method described in this application possesses good CO oxidation capacity and water and sulfur resistance stability. At a flue gas temperature of 230℃ and a CO concentration of [missing information - likely a specific value], [the following information is provided]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation, demonstrating good water and sulfur resistance.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A catalyst for removing carbon monoxide from industrial flue gas, characterized in that, The catalyst has a multilayer composite structure with BaSO4 as the core and TiO2 as the shell. The core is embedded with iron and copper active components and additives, including one or more of manganese, cerium, cobalt, zinc, etc. The molar ratio of BaSO4 core to active components and additives is ≤1:

1.

2. The catalyst for removing carbon monoxide from industrial flue gas according to claim 1, characterized in that, The molar ratio of iron:copper:additive is 1:(0.3~0.5):(0~0.2).

3. A catalyst for removing carbon monoxide from industrial flue gas according to claim 1 or 2, characterized in that, The catalyst uses soluble sulfate as the active component and auxiliary material, barium hydroxide and soluble carbonate and bicarbonate as precipitants, and dilute nitric acid and organic acid as etching agents. Tetrabutyl titanate is used as the titanium source, and ammonia is used as the pH adjuster. By controlling the pH value of the solution, the catalyst precursor is obtained. The catalyst precursor is activated and calcined to obtain a catalyst with a multilayer composite structure.

4. A catalyst for removing carbon monoxide from industrial flue gas according to claim 1 or 2, characterized in that, The catalyst is used at a flue gas temperature of 230℃ and a CO concentration of [missing value]. , concentration Water vapor concentration is airspeed is Under flue gas conditions, the CO conversion rate remained above 95% and the performance was stable after 100 hours of evaluation.

5. A method for preparing a catalyst for removing carbon monoxide from industrial flue gas according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Weigh out the soluble sulfates of the active component and the auxiliary agent respectively, and add them to deionized water at 40-80℃ and stir until completely dissolved to make solution A; (2) Crush barium hydroxide into powder at x times the number of moles of sulfate in solution A and use it as reagent B, where 0 ≤ x ≤ 1; (3) Prepare solution C by mixing nitric acid with an equimolar amount of organic acid and stirring until homogeneous, wherein the sum of the molar amounts of nitric acid and organic acid is y times the molar amount of sulfate, and y <x; (4) Add z times the number of the sulfate moles of the soluble carbonate or bicarbonate to deionized water at 40-80℃ and stir until completely dissolved to form solution D, where z = 1-x+y; (5) Add a certain amount of tetrabutyl titanate to anhydrous ethanol and stir until completely dissolved to form solution E. The molar ratio of tetrabutyl titanate to anhydrous ethanol is 1:(4~9), and the molar ratio of Ti to sulfate is 0.1~1. (6) Add reagent B and solution C to solution A simultaneously under vigorous stirring. Adjust the addition rate of both to ensure that they are added at a uniform rate. After complete addition, continue stirring for 5-10 minutes to obtain suspension S1. (7) Add solution D to suspension S1 with thorough stirring, continue stirring for 10-60 minutes, and adjust its pH to between 7 and 10 with ammonia water to obtain suspension S2; (8) Add solution E to suspension S2 while stirring thoroughly, and continue stirring for 30-600 minutes after the addition is complete to obtain suspension S3; (9) Filter the suspension S3 and wash it until the filtrate is neutral. Dry it at 100-150℃ to constant weight to obtain the catalyst precursor. (10) Add molding aid to the catalyst precursor to form it. The formed catalyst precursor is activated and calcined in a mixed atmosphere of air and nitrogen to obtain the desired catalyst. The oxygen content in the mixed atmosphere is 2-20%, the calcination temperature is 300-550℃, and the calcination time is 2-24 hours.

6. The preparation method according to claim 5, characterized in that, In step (3), the organic acid is one or a mixture of several of acetic acid, lactic acid or citric acid.

7. The preparation method according to claim 5, characterized in that, The soluble carbonate or bicarbonate in step (4) includes one or a mixture of several of the following: ammonium carbonate, sodium carbonate, potassium carbonate, ammonium bicarbonate, sodium bicarbonate, and potassium bicarbonate.

8. The preparation method according to claim 5, characterized in that, In step (7), the pH value is controlled between 7 and 8.

9. The preparation method according to claim 5, characterized in that, The stirring time in step (8) is 30-180 minutes.

10. The preparation method according to claim 5, characterized in that, In step (10), the roasting temperature is 350℃-400℃ and the roasting time is 4-10h.

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