Flue gas sulfur transfer agent as well as preparation method and application thereof

Abstract

The invention discloses a flue gas sulfur transfer agent as well as a preparation method and application thereof, belongs to the technical field of flue gas desulfurization, and aims to solve the technical problem of poor effects of catalyzing oxygen-poor sulfur-containing flue gas desulfurization and hydrogen reduction regeneration of a sulfur transfer agent in the prior art. Comprising the following steps: mixing and stirring manganous nitrate, zinc nitrate, ferric nitrate, cobalt nitrate, nickel nitrate, copper nitrate and deionized water until the system is dissolved, adding activated carbon into the reaction system, carrying out ultrasonic dispersion for 90-120 minutes, and carrying out post-treatment to obtain the loaded carbon. The sulfur transfer agent is prepared by loading metal on the activated carbon in the form of oxide and taking glucose as a soft template on the basis of a microwave coprecipitation method, so that the sulfur capacity and the high temperature resistance of the sulfur transfer agent are effectively improved, and the desulfurization efficiency and the cyclic regeneration effect of the sulfur transfer agent on sulfur-containing oxygen-deficient flue gas are also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas desulfurization, and particularly relates to a flue gas sulfur transfer agent, a preparation method thereof, and an application thereof. Background Art

[0002] Sulfur oxides (SO x , such as SO2, SO3) are one of the main pollutants. At present, flue gas desulfurization technologies mainly include wet desulfurization (such as limestone-gypsum method), dry adsorption (such as activated carbon adsorption), and catalytic oxidation method, etc. The catalytic oxidation desulfurization process is that under the action of a catalyst, SO2 reacts with an oxidant (usually oxygen) to generate SO3.

[0003] At present, in order to reduce the generation of NOx, enterprises usually adopt low-oxygen combustion technology to reduce the oxygen supply, resulting in a low oxygen concentration in the flue gas, forming an oxygen-deficient environment (oxygen content ≤ 5 vol%). During catalytic oxidation desulfurization, the catalytic oxidation of SO2 is incomplete, and SO2 cannot be effectively oxidized to SO3 or sulfate, resulting in a sharp decrease in sulfur capacity. Although porous materials with a high specific surface area (such as activated carbon) can increase the adsorption capacity, their mechanical strength is low and they are prone to powdering during long-term operation. Dense materials with high mechanical strength, due to their narrow pore channels and large mass transfer resistance, are difficult to meet the rapid desulfurization requirements of flue gas with a high sulfur concentration. Moreover, although the activated carbon material increases the adsorption capacity, during the high-temperature regeneration process of activated carbon, partial graphitization may occur, resulting in the shrinkage or closure of micropores, hindering the diffusion of H2 to internal active sites (such as metal sulfides), making the reduction reaction occur only on the surface. After the carbon-containing sulfur transfer agent is reduced by H2, the internal sulfur residue is large, and the catalytic regeneration effect of the sulfur transfer agent is poor.

[0004] In view of the technical deficiencies in this regard, a solution is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a flue gas sulfur transfer agent, a preparation method thereof, and an application thereof, which are used to solve the technical problems of poor catalytic desulfurization of oxygen-deficient sulfur-containing flue gas and poor hydrogen reduction regeneration effect of the sulfur transfer agent in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A preparation method of a flue gas sulfur transfer agent, comprising the following steps: S1. Mix manganese nitrate, zinc nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate and deionized water and stir until the system is dissolved. Add activated carbon to the reaction system, ultrasonically disperse for 90 - 120 min, and perform post-treatment to obtain carbon-supported material; S2. The carbon-supported material is calcined under anaerobic conditions to obtain carbon-supported oxide; S3. Mix aluminum chloride, magnesium chloride, cerium nitrate, and deionized water and stir until the system dissolves. Add carbon supported with oxides, silica sol, and glucose to the reaction system, and stir for 30 - 50 min to obtain a mixed solution. Then transfer it to a microwave reactor at a temperature of 60 - 80°C, keep it warm for 20 - 30 min, add a precipitating agent dropwise to the reactor, adjust the pH of the system to 8 - 10, keep it warm and age for 2 - 3 h, and perform post-treatment to obtain a crude sulfur transfer agent. S4. The crude sulfur transfer agent is subjected to heat treatment to prepare a sulfur transfer agent.

[0007] Further, in step S1, the dosage ratio of manganese nitrate, zinc nitrate, iron nitrate, cobalt nitrate, nickel nitrate, and copper nitrate is 1 mol: 1 mol: 5 mol: 2 mol: 1 mol: 2 mol. The dosage ratio of manganese nitrate, deionized water, and activated carbon is 1 g: 30 mL: 10 - 12 g. The post-treatment includes: after the reaction is completed, the temperature of the reaction system is raised to 90 - 100°C, and low-boiling substances are removed by reduced pressure distillation to obtain carbon supported.

[0008] Further, in step S2, the method of anaerobic calcination is: place the carbon supported in a tube furnace, under an inert atmosphere, raise the temperature of the tube furnace to 450 - 550°C, keep it warm and calcine for 120 - 160 min, perform magnetic separation and screening to obtain carbon supported with oxides.

[0009] Further, in step S3, the dosage ratio of aluminum chloride, magnesium chloride, and cerium nitrate is 1 mol: 1.2 mol: 0.22 mol. The dosage ratio of aluminum chloride, deionized water, carbon supported with oxides, silica sol, and glucose is 10 g: 50 mL: 7 - 8 g: 5 - 6 g: 8 - 9 g. The precipitating agent is composed of urea, ammonium bicarbonate, and deionized water in a ratio of 4 g: 1 g: 15 mL. The post-treatment includes: after the reaction is completed, lower the temperature of the reaction system to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral and then drain it, transfer the filter cake to a drying oven at a temperature of 60 - 70°C, and dry it to constant weight to obtain a crude sulfur transfer agent.

[0010] Further, in step S4, the heat treatment method is: place the crude sulfur transfer agent in a tube furnace, under the protection of an inert atmosphere, raise the temperature of the tube furnace to 500 - 600°C, keep it warm and calcine for 3 - 4 h, introduce air into the tube furnace, raise the temperature of the tube furnace to 800 - 850°C, keep it warm and calcine for 4 - 5 h, cool down and discharge to obtain a sulfur transfer agent.

[0011] Further, the preparation method of the activated carbon is: mix potassium permanganate, 20 wt% hydrogen peroxide, and 6 mol / L nitric acid evenly to obtain an activation solution. Mix the activation solution and activated carbon and stir. Raise the temperature of the reaction system to 60 - 70°C, keep it warm and react for 3 - 4 h, and perform post-treatment to obtain activated carbon.

[0012] The synthesis reaction mechanism of activated carbon is as follows: During the reaction, nitric acid provides an acidic environment, and potassium permanganate and hydrogen peroxide act as oxidants. Under acidic conditions, potassium permanganate and hydrogen peroxide generate intermediate products with higher oxidation activity through synergistic oxidation, accelerating the oxidation reaction, oxidizing organic substances containing electron-rich groups (such as phenols, double bonds, etc.), breaking their unsaturated bonds, and generating oxygen-containing functional groups such as carboxyl and hydroxyl groups. At the same time, the oxidation reaction can also expand the original pores and increase the specific surface area, making it easier for metal ions to be loaded on it.

[0013] Furthermore, the dosage ratio of potassium permanganate, 20wt% hydrogen peroxide, and 6mol / L nitric acid is 2 - 3g:5 - 6mL:20mL, the dosage ratio of the activation solution to activated carbon is 5 - 7mL:1g, the particle size of the activated carbon is 30 - 50μm, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is reduced to room temperature, filtered by suction, the filter cake is washed with purified water until neutral, the filter cake is transferred to a drying oven at 70 - 80°C, and dried to a constant weight to obtain activated carbon.

[0014] A flue gas sulfur transfer agent, which is processed according to a preparation method of a flue gas sulfur transfer agent.

[0015] An application of a flue gas sulfur transfer agent, applying the flue gas sulfur transfer agent prepared according to a preparation method of a flue gas sulfur transfer agent to desulfurize sulfur-containing oxygen-deficient flue gas, wherein the oxygen concentration of the sulfur-containing oxygen-deficient flue gas is 1 - 7 vol%.

[0016] The present invention has the following beneficial effects: 1. For the flue gas sulfur transfer agent of the present invention, the metal is loaded on activated carbon in the form of an oxide, and then based on the microwave co-precipitation method, glucose is used as a soft template to cooperate with the precipitant to promote the formation of a three-dimensional network template. The urea-ammonium bicarbonate precipitant is used to regulate the surface hydroxyl groups and acidic sites, enhance the chemical adsorption ability, optimize the particle size distribution, and increase the mesopore ratio. After high-temperature calcination, aluminum and magnesium oxides form a thermally stable spinel and a mesoporous-macroporous hierarchical structure constructed by silica sol, which is not easy to collapse during high-temperature regeneration, maintains the mass transfer efficiency, inhibits the migration and sintering of active components during the high-temperature process, reduces the specific surface area attenuation, and furthermore, through aerobic high-temperature calcination, promotes the combination of carbon and oxygen to form carbon dioxide, increases the exposed sites of active metals, and improves the oxidative desulfurization efficiency.

[0017] 2. The flue gas sulfur transfer agent of the present invention is prepared by activating activated carbon with an activation solution. The strong oxidizing properties of potassium permanganate, hydrogen peroxide, and nitric acid etch the surface of the activated carbon to generate oxygen-containing functional groups such as carboxyl and hydroxyl groups. The introduction of carboxyl functional groups makes the surface of the activated carbon negatively charged, enhancing the adsorption ability of metal ions through electrostatic interaction, making it easier for metal ions to be anchored on the surface of the activated carbon, improving the loading amount and dispersion. Manganese nitrate, zinc nitrate, iron nitrate, cobalt nitrate, nickel nitrate, and copper nitrate loaded on the activated carbon form composite oxides through high-temperature calcination. By introducing manganese, iron, and copper oxides into the metal oxides, the oxidation of SO2 to SO3 can be promoted through the oxygen storage capacity under oxygen-deficient conditions, significantly improving the desulfurization efficiency. When preparing the sulfur transfer agent, cerium element is introduced to cooperate with the metal oxides to optimize the pore size distribution and further improve the desulfurization efficiency.

[0018] 3. For the flue gas sulfur transfer agent of the present invention, aluminum chloride and magnesium chloride hydrolyze to form aluminum ions and magnesium ions. Silica sol provides a three-dimensional network skeleton. Glucose is partially carbonized under microwave heating to form a soft template, regulating the pore distribution. Its hydroxyl groups coordinate with metals such as aluminum and magnesium to inhibit particle aggregation. Urea in the precipitating agent slowly decomposes into ammonia, uniformly increasing the pH of the solution, promoting the coprecipitation of metal ions in the form of hydroxides. In the precipitated particles, silica sol and glucose template cooperate to form mesopores, increasing its specific surface area. Under an inert atmosphere, the residual carbon of glucose is partially oxidized to CO2 to form a pore structure, and metal nitrates and chlorides decompose into oxides. Al2O3 reacts with MgO to form a MgAl2O4 spinel structure, improving the thermal stability. Under an air atmosphere, the carbon template in the crude sulfur transfer agent is completely oxidized to CO2 to form through pores, increasing the pore size. At the same time, cerium oxide crystallizes, the grain size grows, and the oxygen vacancy density increases. Transition metal oxides such as Fe, Mn, and Co form solid solutions, enhancing the redox activity and improving the oxidative desulfurization efficiency. Zinc, cobalt, and nickel oxides in the sulfur transfer agent enhance the chemisorption and oxidation of SO2 through Lewis acid sites to form composite sulfides, further improving the sulfur capacity of the sulfur transfer agent. Detailed Embodiments

[0019] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0020] In the present invention, the silica sol is selected from Shandong Xiangzhao New Materials Co., Ltd., with the main component being silicon dioxide, the effective component content being 99%, and the solid content being 40%.

[0021] Example 1: This example provides a preparation method of a flue gas sulfur transfer agent, which includes the following steps: Step 1: Prepare activated carbon Mix potassium permanganate, 20wt% hydrogen peroxide, and 6mol / L nitric acid evenly according to the dosage ratio of 2g:5mL:20mL to obtain an activation solution; Add the activation solution and activated carbon with a particle size of 30 - 50μm into a flask at a ratio of 5mL:1g, mix and stir. Raise the temperature of the reaction flask to 60°C, keep the temperature for 3h, then lower the temperature of the reaction flask to room temperature, perform suction filtration, wash the filter cake with purified water until neutral, transfer the filter cake to a drying oven at 70°C, and dry until constant weight to obtain activated carbon.

[0022] Step 2: Prepare the supported oxide Weigh: 17.9g of manganese nitrate, 18.9g of zinc nitrate, 120.9g of iron nitrate, 36.6g of cobalt nitrate, 18.3g of nickel nitrate, 37.5g of copper nitrate, and 537mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 179g of activated carbon to the reaction flask, perform ultrasonic dispersion for 90min, raise the temperature of the reaction flask to 90°C, and remove low-boiling substances under reduced pressure to obtain the supported carbon; Place the supported carbon in a tubular furnace. Under an argon atmosphere, raise the temperature of the tubular furnace to 450°C, keep the temperature for 120min, perform magnetic separation and screening to obtain the supported oxide carbon.

[0023] Step 3: Prepare the crude sulfur transfer agent Weigh: 26.7g of aluminum chloride, 22.9g of magnesium chloride, 14.3g of cerium nitrate, and 133.5mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 18.7g of the supported oxide carbon, 13.4g of silica sol, and 21.4g of glucose to the reaction flask in sequence, and stir for 30min to obtain a mixed solution; Mix urea, ammonium bicarbonate, and deionized water evenly according to the ratio of 4g:1g:15mL to obtain a precipitant; Transfer the mixed solution to a microwave reactor, set the power to 500W and the temperature to 60°C, keep the temperature for 20min. Add the precipitant dropwise to the microwave reactor, adjust the pH of the system to 8, keep the temperature for aging for 2h, lower the temperature of the reaction flask to room temperature, perform suction filtration, wash the filter cake with purified water until neutral and then drain it, transfer the filter cake to a drying oven at 60°C, and dry until constant weight to obtain the crude sulfur transfer agent.

[0024] Step 4: Prepare the sulfur transfer agent Place the crude sulfur transfer agent in a tubular furnace. Under the protection of an argon atmosphere, raise the temperature of the tubular furnace to 500°C, keep the temperature for 3h, introduce air into the tubular furnace, raise the temperature of the tubular furnace to 800°C, keep the temperature for 4 hours, then cool down and discharge to obtain the sulfur transfer agent.

[0025] Example 2: This example provides a preparation method of a flue gas sulfur transfer agent, which includes the following steps: Step 1: Prepare activated carbon Mix potassium permanganate, 20wt% hydrogen peroxide, and 6mol / L nitric acid evenly according to the dosage ratio of 2.5g:5.5mL:20mL to obtain an activation solution; Add the activation solution and activated carbon with a particle size of 30 - 50μm into a flask at a ratio of 6mL:1g, mix and stir. Raise the temperature of the reaction flask to 65°C, keep the temperature for reaction for 3.5h, then lower the temperature of the reaction flask to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral, transfer the filter cake to a drying oven at 75°C, and dry it to constant weight to obtain activated carbon.

[0026] Step 2: Prepare the supported oxide Weigh: 17.9g of manganese nitrate, 18.9g of zinc nitrate, 120.9g of iron nitrate, 36.6g of cobalt nitrate, 18.3g of nickel nitrate, 37.5g of copper nitrate, and 537mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 196.9g of activated carbon into the reaction flask, perform ultrasonic dispersion for 105min, raise the temperature of the reaction flask to 95°C, and remove low-boiling substances under reduced pressure to obtain the supported carbon; Place the supported carbon in a tubular furnace. Under an argon atmosphere, raise the temperature of the tubular furnace to 500°C, keep the temperature for roasting for 140min, perform magnetic separation and screening to obtain the supported oxide carbon.

[0027] Step 3: Prepare the crude sulfur transfer agent Weigh: 26.7g of aluminum chloride, 22.9g of magnesium chloride, 14.3g of cerium nitrate, and 133.5mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 20.1g of the supported oxide carbon, 14.7g of silica sol, and 22.7g of glucose into the reaction flask in sequence, and stir for 40min to obtain a mixed solution; Mix urea, ammonium bicarbonate, and deionized water evenly according to the ratio of 4g:1g:15mL to obtain a precipitant; Transfer the mixed solution to a microwave reactor, set the power to 600W and the temperature to 70°C, keep the temperature for treatment for 25min. Drop the precipitant into the microwave reactor, adjust the pH of the system to 9, keep the temperature for aging for 2.5h, lower the temperature of the reaction flask to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral and then drain it, transfer the filter cake to a drying oven at 65°C, and dry it to constant weight to obtain the crude sulfur transfer agent.

[0028] Step 4: Prepare the sulfur transfer agent Place the crude sulfur transfer agent in a tubular furnace. Under the protection of an argon atmosphere, raise the temperature of the tubular furnace to 550 °C, keep it for roasting for 3.5 h, introduce air into the tubular furnace, raise the temperature of the tubular furnace to 825 °C, keep it for roasting for 4.5 h, cool down and discharge the material to obtain the sulfur transfer agent.

[0029] Example 3: This example provides a method for preparing a flue gas sulfur transfer agent, including the following steps: Step 1: Prepare activated carbon Mix potassium permanganate, 20 wt% hydrogen peroxide, and 6 mol / L nitric acid evenly according to the dosage ratio of 3 g: 6 mL: 20 mL to obtain an activation solution; Add the activation solution and activated carbon with a particle size of 30 - 50 μm into a flask at a ratio of 7 mL: 1 g, mix and stir. Raise the temperature of the reaction flask to 70 °C, keep it for reaction for 4 h, lower the temperature of the reaction flask to room temperature, carry out suction filtration, wash the filter cake with purified water until neutral, transfer the filter cake to a drying oven at 80 °C, and dry it to constant weight to obtain activated carbon.

[0030] Step 2: Prepare the supported oxide Weigh: 17.9 g of manganese nitrate, 18.9 g of zinc nitrate, 120.9 g of iron nitrate, 36.6 g of cobalt nitrate, 18.3 g of nickel nitrate, 37.5 g of copper nitrate, and 537 mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 214.8 g of activated carbon into the reaction flask, disperse it ultrasonically for 120 min, raise the temperature of the reaction flask to 100 °C, and distill off the low-boiling substances under reduced pressure to obtain the supported carbon; Place the supported carbon in a tubular furnace. Under an argon atmosphere, raise the temperature of the tubular furnace to 550 °C, keep it for roasting for 160 min, carry out magnetic separation and screening to obtain the supported oxide carbon.

[0031] Step 3: Prepare the crude sulfur transfer agent Weigh: 26.7 g of aluminum chloride, 22.9 g of magnesium chloride, 14.3 g of cerium nitrate, and 133.5 mL of deionized water, add them into a reaction flask, mix and stir until the system is dissolved. Add 21.4 g of the supported oxide carbon, 16.0 g of silica sol, and 24.0 g of glucose into the reaction flask in sequence, and stir for 50 min to obtain a mixed solution; Mix urea, ammonium bicarbonate, and deionized water evenly according to the ratio of 4 g: 1 g: 15 mL to obtain a precipitant; Transfer the mixed solution to a microwave reactor, set the power to 700 W and the temperature to 80 °C, keep it for treatment for 30 min. Add the precipitant dropwise into the microwave reactor, adjust the pH of the system to 10, keep it for aging for 3 h, lower the temperature of the reaction flask to room temperature, carry out suction filtration, wash the filter cake with purified water until neutral and then drain it, transfer the filter cake to a drying oven at 70 °C, and dry it to constant weight to obtain the crude sulfur transfer agent.

[0032] Step 4: Preparation of sulfur transfer agent Place the crude sulfur transfer agent in a tubular furnace. Under the protection of an argon atmosphere, raise the temperature of the tubular furnace to 600 °C, keep it for roasting for 4 h, introduce air into the tubular furnace, raise the temperature of the tubular furnace to 850 °C, keep it for roasting for 5 h, cool down and discharge to obtain the sulfur transfer agent.

[0033] Comparative Example 1. The difference between this comparative example and Example 3 is that Step 1 is cancelled, and the activated carbon in Step 1 is replaced by the activated carbon in Step 2.

[0034] Comparative Example 2. The difference between this comparative example and Example 3 is that in Step 2, zinc nitrate and nickel nitrate are not added.

[0035] Comparative Example 3. The difference between this comparative example and Example 3 is that in Step 3, glucose is not added.

[0036] Comparative Example 4. The difference between this comparative example and Example 3 is that in Step 4, the preparation method of the sulfur transfer agent is: place the crude sulfur transfer agent in a tubular furnace. Under the protection of an argon atmosphere, raise the temperature of the tubular furnace to 600 °C, keep it for roasting for 4 h, cool down and discharge to obtain the sulfur transfer agent.

[0037] Performance test: Use the sulfur transfer agents prepared in Examples 1-3 and Comparative Examples 1-4 as the test samples to be tested; Oxidative adsorption desulfurization: Load the test sample to be tested into a quartz tube with an inner diameter of 10 mm, fill quartz wool at both ends of the quartz tube to prevent the test sample cup from being blown away, raise the temperature of the quartz tube to 650 °C, and pass the sulfur-containing oxygen-deficient flue gas with an oxygen content of 1 vol% into the quartz tube at a conveying rate of 70 mL / min, and measure the desulfurization efficiency of the sulfur transfer agent with reference to Formula 1; Reductive regeneration: After half a cycle of oxidative adsorption desulfurization, purge the quartz tube with nitrogen until the temperature drops to 500 °C, and pass hydrogen into the quartz tube at a conveying rate of 70 mL / min for 30 min to obtain the regenerated desulfurization transfer agent; Circulation test: Conduct oxidative adsorption desulfurization and reductive regeneration in sequence according to the above tests, repeat the operation 10 times, and measure the desulfurization efficiency of the test sample to be tested during the tenth test; Formula 1: , where C1 is the concentration of sulfur dioxide in the sulfur-containing oxygen-deficient flue gas entering the quartz tube, C2 is the concentration of sulfur dioxide in the sulfur-containing oxygen-deficient flue gas discharged from the quartz tube, V is the conveying rate of the sulfur-containing oxygen-deficient flue gas, and t is the conveying time of the sulfur-containing oxygen-deficient flue gas; Measure the sulfur capacity of the test sample to be tested with reference to the standard HG / T 5318-2018 "Test Method for Sulfur Capacity of Manganese Oxide Desulfurizer"; The specific test results are shown in Table 1 below.

[0038] Table 1 - Data Sheet for Performance Testing of Samples

[0039] Data Analysis: By comparing and analyzing the data in Table 1 above, the sulfur capacity of the sulfur transfer agent prepared by the present invention reaches 272.4 mg / g, the first desulfurization efficiency for sulfur-containing oxygen-deficient flue gas reaches 96.8%, the desulfurization efficiency reaches 95.9% after ten cycles, and the retention rate of desulfurization efficiency reaches 99%. The results of all performance tests are better than those of the comparative example. It shows that by loading the metal in the form of oxide on activated carbon and then based on the microwave co-precipitation method, using glucose as a soft template to cooperate with the precipitating agent to promote the formation of a three-dimensional network template, and combining the urea-ammonium bicarbonate precipitating agent to regulate the surface hydroxyl groups and acidic sites, enhancing the chemisorption ability, optimizing the particle size distribution to increase the mesopore ratio, and preparing the sulfur transfer agent through high-temperature calcination, not only effectively improves the sulfur capacity and high-temperature resistance of the sulfur transfer agent, but also improves its desulfurization efficiency and cyclic regeneration effect for sulfur-containing oxygen-deficient flue gas.

[0040] The above content is only an example and explanation of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar methods to replace them. As long as it does not deviate from the structure of the invention or exceed the scope defined by this claims, it shall fall within the protection scope of the present invention.

[0041] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0042] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor limit the present invention to only the specific implementation manners. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation method of a flue gas sulfur transfer agent, characterized in that, It includes the following steps: S1. Mix manganese nitrate, zinc nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate and deionized water and stir until the system is dissolved. Add activated carbon to the reaction system, ultrasonically disperse for 90 - 120 min, and perform post-treatment to obtain carbon-supported material. S2. The carbon-supported material is calcined under anaerobic conditions to obtain carbon-supported oxide. S3. Mix aluminum chloride, magnesium chloride, cerium nitrate and deionized water and stir until the system is dissolved. Add carbon-supported oxide, silica sol and glucose to the reaction system and stir for 30 - 50 min to obtain a mixed solution. Then transfer it to a microwave reactor at a temperature of 60 - 80 °C, keep warm for 20 - 30 min, add a precipitating agent dropwise to the reactor, adjust the pH of the system to 8 - 10, keep warm and age for 2 - 3 h, and perform post-treatment to obtain a crude sulfur transfer agent. S4. The crude sulfur transfer agent is heat-treated to prepare a sulfur transfer agent.

2. The preparation method of a flue gas sulfur transfer agent according to claim 1, characterized in that, In step S1, the dosage ratio of manganese nitrate, zinc nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate is 1 mol:1 mol:5 mol:2 mol:1 mol:2 mol, and the dosage ratio of manganese nitrate, deionized water and activated carbon is 1 g:30 mL:10 - 12 g. The post-treatment includes: after the reaction is completed, the temperature of the reaction system is raised to 90 - 100 °C, and low-boiling substances are removed by reduced pressure evaporation to obtain carbon-supported material.

3. The preparation method of a flue gas sulfur transfer agent according to claim 1, characterized in that, In step S2, the anaerobic calcination method is: place the carbon-supported material in a tubular furnace, under an inert atmosphere, raise the temperature of the tubular furnace to 450 - 550 °C, keep warm and calcine for 120 - 160 min, perform magnetic separation and screening to obtain carbon-supported oxide.

4. The preparation method of a flue gas sulfur transfer agent according to claim 1, characterized in that, In step S3, the dosage ratio of aluminum chloride, magnesium chloride, cerium nitrate is 1 mol:1.2 mol:0.22 mol, and the dosage ratio of aluminum chloride, deionized water, carbon-supported oxide, silica sol and glucose is 10 g:50 mL:7 - 8 g:5 - 6 g:8 - 9 g. The precipitating agent is composed of urea, ammonium bicarbonate and deionized water in a ratio of 4 g:1 g:15 mL. The post-treatment includes: after the reaction is completed, lower the temperature of the reaction system to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral and then drain it, transfer the filter cake to a drying oven at a temperature of 60 - 70 °C, and dry it to constant weight to obtain a crude sulfur transfer agent.

5. The preparation method of a flue gas sulfur transfer agent according to claim 1, characterized in that, In step S4, the heat treatment method is: place the crude sulfur transfer agent in a tubular furnace, under the protection of an inert atmosphere, raise the temperature of the tubular furnace to 500 - 600 °C, keep warm and calcine for 3 - 4 h, introduce air into the tubular furnace, raise the temperature of the tubular furnace to 800 - 850 °C, keep warm and calcine for 4 - 5 h, cool down and discharge to obtain a sulfur transfer agent.

6. The preparation method of a flue gas sulfur transfer agent according to claim 1, characterized in that, The preparation method of the activated carbon is: mix potassium permanganate, 20 wt% hydrogen peroxide and 6 mol / L nitric acid evenly to obtain an activation solution, mix the activation solution and activated carbon and stir, raise the temperature of the reaction system to 60 - 70 °C, keep warm and react for 3 - 4 h, and perform post-treatment to obtain activated carbon.

7. The preparation method of a flue gas sulfur transfer agent according to claim 6, characterized in that, The dosage ratio of potassium permanganate, 20wt% hydrogen peroxide and 6mol / L nitric acid is 2-3 g: 5-6 mL: 20 mL, the dosage ratio of the activation liquid and activated carbon is 5-7 mL: 1 g, the particle size of the activated carbon is 30-50 μm, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is reduced to room temperature, suction filtration is carried out, the filter cake is washed with purified water until neutral, the filter cake is transferred to a drying oven at 70-80 °C, and dried to constant weight to obtain activated carbon.

8. A flue gas sulfur transfer agent, characterized in that, The flue gas sulfur transfer agent is prepared according to the preparation method of a flue gas sulfur transfer agent as described in any one of claims 1-7.

9. Application of a flue gas sulfur transfer agent, characterized in that, The flue gas sulfur transfer agent prepared by the preparation method of a flue gas sulfur transfer agent as described in any one of claims 1-7 is applied to the desulfurization of sulfur-containing oxygen-deficient flue gas.

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