Desulfurization adsorbent as well as preparation method and application thereof in flue gas desulfurization

Abstract

The invention provides a desulfurization adsorbent as well as a preparation method and application thereof in flue gas desulfurization. The preparation method comprises the following steps: mixing an aqueous solution containing at least two active metal component precursor salts, an aqueous solution of a precipitator, an organic solvent, an anionic surfactant and a cosurfactant in a closed system, and then carrying out dynamic crystallization, and sequentially washing, drying, grinding, roasting and granulating a precipitate obtained by the dynamic crystallization reaction to obtain the desulfurization adsorbent. On the basis, the specific surface area of the adsorbent can be effectively increased, the dispersity of active components is improved, the preparation process flow is shortened, and the desulfurization performance is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical industry environmental protection, and relates to a desulfurization adsorbent, a preparation method thereof and an application in flue gas desulfurization. Background Art

[0002] With the rapid development of modern industry, the consumption of fossil fuels such as coal, oil and natural gas is increasing day by day, and the amounts of pollutants such as soot, SO x , NO x emitted into the atmosphere are rising year by year. Among them, the acidic gas SO x mainly comes from fossil fuel combustion, the combustion emission of acidic gas during the operation of oil and gas wells containing H2S, and industrial production processes such as metal smelting. As one of the main atmospheric pollutants, its large amount of emission will cause serious harm to the ecological environment and human health. There are various measures to control SO x pollution, but flue gas desulfurization technology is the only desulfurization technology that has been commercially applied on a large scale. So far, researchers have invented more than two hundred flue gas desulfurization methods in total, in order to reduce the impact of SO x on the environment. Although there are various flue gas desulfurization processes, the desulfurization technologies that can be widely applied and dominate in practice at present are mainly wet method, dry method and semi-dry method. Among them, compared with the other two desulfurization processes, the dry method has a simple process flow and no waste residue generation. Dry flue gas desulfurization, that is, adsorption desulfurization technology, its principle is to remove organic sulfur in petroleum fractions or SO x in flue gas through physical / chemical adsorption, so as to effectively reduce the emission of gas sulfides. During the whole desulfurization process, the physical and chemical properties of the desulfurization agent have a great influence on the desulfurization efficiency.

[0003] In the existing dry flue gas desulfurization process, the types of desulfurization agents selected mainly include single metal oxide type, supported oxide type and composite metal oxide type. Compared with the first two desulfurization agents, the composite metal oxide type desulfurization agent not only has a high sulfur capacity, but also has the same adsorption and regeneration reaction temperature (similar to the flue gas temperature), which can avoid the adverse effects caused by temperature changes on the structure and desulfurization performance of the desulfurization agent. At present, there are many patents and literature reports on dry flue gas desulfurization, but most of them focus on the research of medium and low temperature flue gas desulfurization technology. Even if there are reports on high temperature flue gas desulfurization above 500 °C, the prepared desulfurization agents often have disadvantages such as poor dispersion of active components and low specific surface area.

[0004] Chinese Patent CN115350701A discloses a preparation method of a desulfurization manganese-aluminum composite metal oxide additive rich in defect sites for calcium-based desulfurizer. In this method, the manganese-aluminum composite metal oxide is first soaked in an excessive alkali solution for a set time, and aluminum metal cation defect sites are formed on the surface of the composite metal oxide through alkali etching. Then, the above composite metal oxide rich in defect sites is added to the calcium-based desulfurizer according to a set ratio to obtain a calcium-based desulfurizer with higher desulfurization activity and sulfur adsorption capacity. Although the desulfurization temperature (120°C) prepared by this method is relatively low, the desulfurizer is difficult to regenerate and cannot be reused.

[0005] Chinese Patent CN115400578A discloses a preparation method of a dry flue gas desulfurizer. In this method, quicklime powder is mixed with an expanding agent (including organic salts and inorganic salts), and then mixed with curing water for curing. After curing, it is dried at a low temperature, ground into powder, and finally mixed with a dispersant to obtain the flue gas desulfurizer. After the desulfurizer powder prepared by this technology enters the flue, the high temperature causes the expanding agent to decompose rapidly and generate gas, making the desulfurizer powder further become finer into sub-micron calcium hydroxide powder, so as to fully contact with sulfur dioxide and achieve the purpose of efficient desulfurization. In addition, the desulfurization product can be used as a raw material for a cement plant. However, as a calcium-based desulfurizer, the desulfurizer is difficult to regenerate, which increases the desulfurization operation cost to a certain extent.

[0006] Chinese Patent CN115253622A discloses a preparation method of a sodium-based dry desulfurizer. The sodium-based dry desulfurizer prepared by this method is obtained by preparing primary fine particles of sodium carbonate below 10 μm through ultra-fine pulverization methods such as spray drying, ultra-fine grinding, or high-speed air flow pulverization, and then further granulating and forming to obtain secondary particles with a particle size of 1 - 10 mm for direct application in dry desulfurization. The desulfurizer prepared by this method is used for flue gas desulfurization, with a lower desulfurization temperature (80°C ≤ T < 100°C), a wider application range, high desulfurization activity, and the desulfurization cost can be reduced by more than 20%. Although low-temperature flue gas desulfurization can save a large amount of flue gas heating cost, the desulfurization effect is less affected by temperature fluctuations and is easy to operate and control. However, the desulfurizer is difficult to regenerate and generates solid waste residues; in addition, for low-temperature flue gas desulfurization, the overall sulfur capacity is relatively low and it is not suitable for treating high-sulfur flue gas.

[0007] Chinese Patent CN115253623A discloses a preparation method of a composite metal oxide type high-temperature flue gas desulfurizer. In this method, a first binder containing pseudoboehmite or aluminum sol, and a second binder (active gel) made from the first, second, and third metals, a modifying compound, etc. are mixed and formed with a carrier. Among them, the active sol can increase the specific surface area of the desulfurizer to a certain extent. Finally, active metal oxides such as V and rare earth elements (La or Ce) are loaded on the surface of the desulfurizer through impregnation and calcination. The desulfurizer prepared by this method shows good regeneration performance when treating flue gas with a SO2 concentration of 1500 - 5000 mg / m 3 at 650 °C, and the desulfurization efficiency is above 95%. However, the dispersion of the active components of the desulfurizer prepared by the impregnation method is poor.

[0008] Chinese Patent CN108329954A discloses a preparation method of a medium-temperature multivalent metal oxide desulfurizer for desulfurizing syngas produced by atmospheric coal pyrolysis. In this method, a powder obtained by ball milling an adsorbent composed of hematite, magnetite, pyrolusite, and cuprite ore, a reducing agent composed of magnesium powder and iron powder, and a certain amount of grinding aid is cold-pressed and formed, and then crushed and granulated to obtain a granular multivalent metal oxide desulfurizer. During the ball milling process, under the action of mechanochemistry, the reducing agent reduces part of the easily variable-valence metal oxides in the adsorbent to a low valence state and generates oxygen vacancy defects, thereby improving the desulfurization efficiency to a certain extent. Although the overall preparation process of this method is simple, ball milling and mixing are not conducive to the uniformity of the distribution of metal elements in the desulfurizer, thus limiting the further improvement of the desulfurization efficiency.

[0009] Chinese Patent CN113713800A discloses a preparation method of a high-temperature flue gas desulfurizer. In this method, the product obtained by co-precipitation and hydrothermal reaction of a divalent metal ion salt and a water-soluble aluminum salt in sequence is dried and ground to obtain a layered double metal hydroxide precursor, and then catalytically active components are embedded into the precursor through an ion exchange reaction. Finally, a high-temperature flue gas desulfurizer with good high-temperature stability, strong desulfurization ability, and regeneration performance is obtained by calcination. Compared with the mechanical mixing method, the two-step reaction can significantly increase the specific surface area of the desulfurizer, and the ion exchange reaction can also improve the dispersion degree of the active metal to a certain extent compared with the impregnation method, thereby enhancing the desulfurization performance of the desulfurizer. However, the overall preparation process is complex.

[0010] Chinese Patent CN107159093A discloses a preparation method of a flue gas desulfurization agent. This method first mixes α-MnO₂ with an alkali solution, then stirs and refluxes the reaction at a certain temperature, and finally washes, filters, and dries the product to obtain a high-temperature-resistant MnO₂ flue gas desulfurization agent. Although this preparation method is simple, low in cost, and has good thermal stability, and can be used for the removal of sulfur oxides in high-temperature flue gas at 100 - 750 °C, the overall sulfur capacity of the desulfurization agent prepared by this method is still relatively low (below 10%).

[0011] Chinese Patent CN104209084A discloses a preparation method of a Claus tail gas SO₂ adsorbent. This method first makes an aqueous solution of transition metals, magnesium, and aluminum nitrates, and mixes it with an alkaline solution made of sodium hydroxide and sodium carbonate at a certain dropping rate under rapid stirring to form a hydrotalcite-like powder by coprecipitation. Then, Ce, Y, or La is loaded on the surface of the hydrotalcite by the impregnation method. Finally, high-temperature-resistant cement and carboxymethyl cellulose are added for molding and roasting to obtain an adsorbent with a sulfur capacity of more than 10%. The overall preparation process is simple, the adsorbent has high strength and good wear resistance, and the desulfurization rate of the Claus tail gas with a relatively high SO₂ content can reach more than 90% at high temperature. However, the impregnation method is not conducive to the dispersion of active metal promoters, so it limits the desulfurization activity to a certain extent.

[0012] Chinese Patent CN106867593A discloses a preparation method of a Zn-Al hydrotalcite-based medium and high-temperature coal gas desulfurization agent. This method uses a mixed salt solution of zinc and aluminum to microwave synthesize a Zn-Al hydrotalcite precursor by microwave hydrothermal crystallization reaction to obtain Zn-Al hydrotalcite, and then dries and roasts it to obtain a desulfurization active component Zn-Al composite oxide; it is ground, extruded, and formed with powdered volcanic rock particles and roasted to obtain a Zn-Al hydrotalcite-based medium and high-temperature coal gas desulfurization agent. The desulfurization agent prepared by this method is used for the desulfurization and purification of medium and high-temperature coal gas, and has high desulfurization accuracy, strong anti-reduction ability, and good performance in multiple sulfidation and regeneration cycles. However, the overall specific surface area of the desulfurization agent prepared by this method is relatively low, which is not conducive to the diffusion and mass transfer of gas reactants and (or) products and the timely dissipation of reaction heat, and limits the improvement of the anti-sintering ability to a certain extent.

[0013] Chinese Patent CN101829539A discloses a preparation method of a flower-shaped NiAl composite oxide desulfurizer. In this method, nickel nitrate and aluminum nitrate are dissolved in distilled water, and urea is added under vigorous stirring. The obtained microemulsion is placed in a water bath reactor and crystallized at 90 - 100 °C with stirring for 24 - 46 h. After filtration, washing, and drying, a NiAl hydrotalcite precursor is obtained. Finally, it is calcined in a muffle furnace at 500 °C for 4 h to obtain the flower-shaped NiAl composite oxide desulfurizer. The NiAl composite oxide prepared by this method shows good SO2 adsorption performance in the SO2 adsorption experiment. However, compared with ternary, quaternary, or even quinary composite metal oxide desulfurizers added with metal element additives, the overall sulfur capacity is relatively low and the regeneration process cannot be regulated.

[0014] Chinese Patent CN102895852A discloses a clean process preparation method for the active component of a catalytic cracking flue gas sulfur transfer agent. In this method, without adding any alkaline substances and metal salts, a slurry made of oxides, hydroxides, carbonates, or basic carbonates of Mg, Al, and other metal elements (one or more of V, Cr, Mn, Fe, Co, Cu, Zn, rare earth metals, and noble metals) is directly synthesized into a hydrotalcite-like precursor under high-temperature and high-pressure conditions, and finally, a catalytic cracking flue gas sulfur transfer agent is obtained by high-temperature calcination. Compared with the ordinary preparation process, this method does not contain other ions in the synthesis system, does not produce a large amount of inorganic salt waste liquid, and does not require washing. It is an environmentally friendly preparation process, and the prepared sulfur transfer agent has good sulfur transfer performance. However, the overall desulfurization activity improvement is not high.

[0015] Chinese Patent CN101905117A discloses a preparation method for the active component of a catalytic cracking flue gas sulfur transfer agent. This method uses the calcination-reduction method to obtain a Ce-loaded magnesium-aluminum hydrotalcite or a multi-component hydrotalcite precursor containing other elements (one or more of Zn, V, Fe, Cu, Co, Ni), and then a catalytic cracking flue gas sulfur transfer agent is obtained by high-temperature calcination. Compared with the co-precipitation method and the impregnation method, the sulfur transfer agent prepared by the calcination-reduction method has a lower reduction temperature (starting to be reduced at 580 °C), and at the same time has a higher oxidation sulfur absorption capacity. And when Fe is contained in the hydrotalcite precursor, the lowest reduction temperature can be further reduced to 550 °C. Although the calcination-reduction method can improve the dispersion degree of the loaded Ce to a certain extent and enhance the desulfurization activity, there are still certain limitations compared with the directly prepared multi-metal hydrotalcite by the one-step method. Summary of the Invention

[0016] In order to improve the above problems, according to one aspect of the present invention, a method for preparing a desulfurization adsorbent is provided, which includes the following steps: mixing an aqueous solution containing at least two active metal component precursor salts, an aqueous solution of a precipitating agent, an organic solvent, an anionic surfactant, and a co-surfactant in a closed system and then performing dynamic crystallization; and washing, drying, grinding, calcining, and granulating the precipitate obtained from the dynamic crystallization reaction in sequence to obtain the desulfurization adsorbent.

[0017] The first active metal component precursor salt is selected from one or more of Mg-containing salts, Ca-containing salts, Sr-containing salts, Ni-containing salts, Zn-containing salts, Cu-containing salts, and Mn-containing salts; the second active metal component precursor salt is selected from one or more of Al-containing salts, Fe-containing salts, Ce-containing salts, Cr-containing salts, La-containing salts, Co-containing salts, and V-containing salts; the molar ratio of the metal element in the first active metal component precursor salt to the metal element in the second active metal component precursor salt is 1:0.1 - 0.5.

[0018] The present invention uses an anionic surfactant, a co-surfactant, multiple active metal component precursor salts, and a precipitating agent as raw materials to prepare a desulfurization adsorbent by a solvothermal method, which can effectively control the mesoscopic structure of the desulfurizer. At the same time, by utilizing the synergistic effect of multiple metals, the role of the active metals is further exerted. During the preparation process, the addition of the anionic surfactant can form an oil-in-water microemulsion system; moreover, the addition of the co-surfactant can synergistically stabilize the above microemulsion system. In this way, during the solvothermal reaction process, the lamellae of the composite metal hydroxide crystal nuclei are positively charged, and they adsorb around the head of the anionic surfactant under electrostatic force and self-assemble, which can effectively increase the specific surface area of the adsorbent, improve the dispersion degree of the active components, shorten the preparation process flow, and enhance the desulfurization performance.

[0019] In some alternative embodiments, the first active metal component precursor salt is selected from one or more of nitrates, sulfates, acetates, or chlorides containing elements such as Mg, Ca, Sr, Ni, Zn, Cu, and Mn; the second active metal component precursor salt is selected from one or more of nitrates, sulfates, acetates, or chlorides containing elements such as Al, Fe, Ce, Cr, La, Co, and V.

[0020] In a preferred embodiment, the crystallization temperature for dynamic crystallization is 80 - 150 °C, the dynamic rotation speed is 50 - 100 rpm, and the crystallization time for dynamic crystallization is 12 - 24 h. Further, the calcination temperature is 400 - 700 °C and the time is 5 - 12 h. Further, the above washing is carried out by centrifugal washing. Preferably, the washing includes: first washing the material with deionized water until neutral, and then washing the material with ethanol. Further, the drying treatment temperature is 60 - 90 °C. Further, the particle size of the desulfurization adsorbent obtained by granulation is 10 - 40 mesh; preferably, granulation is carried out on a powder tableting machine. Further, the closed system is a high-pressure reaction kettle; the above dynamic crystallization is carried out in a dynamic oven.

[0021] In a preferred embodiment, the dosage of the anionic surfactant is 20 - 60% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant is 20 - 60% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant to the active metal in the desulfurization adsorbent calculated as the oxide is 5 - 15:1.

[0022] Further, in the mixture system of the aqueous solution containing at least two active metal component precursor salts, the aqueous solution of the precipitant, the organic solvent, the surfactant and the co-surfactant, the weight ratio of the organic solvent to water is 0.7 - 1.2:1.

[0023] In a preferred embodiment, the anionic surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium hexadecylsulfonate, lauric acid, stearic acid, oleic acid, sodium dodecylaminopropionate and sodium N-dodecylsarcosinate. The co-surfactant is selected from one or more of ethylamine, n-propylamine, isopropylamine, n-propylamine, isopropylamine, n-pentylamine, isopentylamine, n-hexylamine, 2-ethylhexylamine, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, n-hexanol and 2-hexanol. The organic solvent is selected from one or more of pentane, hexane, octane, cyclopentane, cyclohexane and cyclooctane. The precipitant is selected from one or more of urea, sodium hydroxide and sodium carbonate.

[0024] According to another aspect of the present invention, a desulfurization adsorbent is provided, which is prepared by the preparation method of the aforementioned desulfurization adsorbent. For the reasons described above, the adsorbent of the present invention has excellent specific surface area, active component dispersion degree and desulfurization performance.

[0025] According to another aspect of the present invention, an application of the aforementioned desulfurization adsorbent in flue gas desulfurization is provided.

[0026] In some alternative embodiments, the flue gas is preferably the sulfur-containing flue gas discharged from a refinery or a Claus sulfur recovery unit of a purification plant. The volume fraction of SO2 in the sulfur-containing flue gas is 0.1 - 2%, and the volume fraction of O2 is 2 - 8%. The adsorption reaction temperature for the above desulfurization adsorption in flue gas desulfurization is 400 - 600 °C.

[0027] In an alternative embodiment, the desulfurization process is carried out in a fixed-bed reactor. The flue gas flows through the solid bed, and SO2 in the flue gas is converted into metal sulfate by catalytic oxidation and adsorbed on the above desulfurizer. Then, under the action of the reducing gas, sulfur in the metal sulfate on the desulfurizer is reduced to elemental sulfur, SO2, and H2S, and at the same time, the desulfurizer is regenerated. The reduced gas is returned to the sulfur recovery unit to further recover sulfur therein. Further, the reducing and regenerating gas is one of 10% H2 / N2 by volume concentration, 10% H2S / N2 by volume concentration, 10% CH4 / N2 by volume concentration, and 10% CO / N2 by volume concentration, preferably 10% H2 / N2 by volume concentration. Specific embodiments

[0028] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the scope of implementation of the present invention.

[0029] Example 1

[0030] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixed solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0031] Prepare 200 mL of an aqueous urea solution, denoted as mixed solution II. Among them, the concentration of urea is 10 mol / L.

[0032] Add mixed solution I and mixed solution II into another beaker simultaneously, and add 4 g of sodium dodecylbenzenesulfonate, 2.7 g of n-pentanol, and 300 g of n-hexane, and stir at room temperature for 0.5 h to obtain mixed solution III.

[0033] Transfer mixed solution III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and carry out dynamic crystallization at 120 °C and a rotation speed of 60 rpm for 12 h. Then, carry out centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an 85 °C oven and then ground into powder.

[0034] The powder was then transferred to a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere to obtain a composite metal oxide desulfurization adsorbent S1, where the heating rate was 2 °C / min.

[0035] The composite metal oxide desulfurization adsorbent S1 was pressed on a powder tablet press. After pressing and crushing it into 20-40 mesh particles, it could be used for the flue gas desulfurization reaction.

[0036] Among them, the dosage of the anionic surfactant sodium dodecylbenzenesulfonate was 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol was 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide was 10:1.

[0037] Example 2

[0038] Prepare a 200 mL mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixed solution I. Among them, the concentration of magnesium nitrate was 0.7425 mol / L, the concentration of copper nitrate was 0.0075 mol / L, the concentration of aluminum nitrate was 0.21 mol / L, and the concentration of iron nitrate was 0.04 mol / L.

[0039] Prepare a 200 mL aqueous urea solution, denoted as mixed solution II. Among them, the concentration of urea was 10 mol / L.

[0040] Add mixed solutions I and II to another beaker simultaneously, and add 4 g of stearic acid, 2.7 g of n-pentanol, and 300 g of n-hexane. Stir at room temperature for 0.5 h to obtain mixed solution III.

[0041] Transfer mixed solution III to a 1000 mL polytetrafluoroethylene high-pressure reaction kettle and react at 120 °C and a rotation speed of 60 rpm for 12 h. Then, centrifuge and wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid was dried overnight in an 85 °C oven and then ground into powder.

[0042] The powder was then transferred to a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere to obtain a composite metal oxide desulfurization adsorbent S2, where the heating rate was 2 °C / min.

[0043] The composite metal oxide desulfurization adsorbent S2 was pressed on a powder tablet press. After pressing and crushing it into 20-40 mesh particles, it could be used for the flue gas desulfurization reaction.

[0044] Among them, the dosage of the anionic surfactant stearic acid is 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide is 10:1.

[0045] Example 3

[0046] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixed solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0047] Prepare 200 mL of an aqueous urea solution, denoted as mixed solution II. Among them, the concentration of urea is 10 mol / L.

[0048] Add mixed solutions I and II into another beaker simultaneously, and add 4 g of sodium N-dodecylsarcosinate, 2.7 g of n-pentanol, and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixed solution III.

[0049] Transfer mixed solution III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and react at 120 °C and a rotation speed of 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0050] Transfer the above powder to a muffle furnace and calcine it in an air atmosphere at 500 °C for 8 h to obtain the composite metal oxide desulfurization adsorbent S3, where the heating rate is 2 °C / min.

[0051] The composite metal oxide desulfurization adsorbent S3 is pressed on a powder tablet press. After pressing and crushing it into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0052] The dosage of the anionic surfactant sodium N-dodecylsarcosinate is 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide is 10:1.

[0053] Example 4

[0054] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0055] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0056] Add mixture I and II to another beaker simultaneously, and add 4 g of sodium N-dodecylsarcosinate, 2.7 g of n-pentanol, and 300 g of n-hexane. Stir for 0.5 h at room temperature to obtain mixture III.

[0057] Transfer mixture III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and react at 120 °C and a rotation speed of 60 rpm for 8 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0058] Transfer the above powder to a muffle furnace and calcine it in an air atmosphere at 500 °C for 8 h to obtain the composite metal oxide desulfurization adsorbent S4, where the heating rate is 2 °C / min.

[0059] The composite metal oxide desulfurization adsorbent S4 is pressed on a powder tablet press. After pressing and crushing it into 20-40 mesh particles, it can be used for flue gas desulfurization reaction.

[0060] The dosage of the anionic surfactant sodium N-dodecylsarcosinate is 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide is 10:1.

[0061] Example 5

[0062] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0063] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0064] Add the mixture I and II into another beaker simultaneously, and add 4 g of sodium N-dodecylsarcosinate, 2.7 g of n-pentanol and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixture III.

[0065] Transfer mixture III into a 1000 mL polytetrafluoroethylene autoclave, and carry out dynamic crystallization at 120 °C and 60 rpm for 16 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0066] Transfer the above powder into a muffle furnace, and calcine in an air atmosphere at 500 °C for 8 h to obtain the composite metal oxide desulfurization adsorbent S5, where the heating rate is 2 °C / min.

[0067] The composite metal oxide desulfurization adsorbent S5 is pressed on a powder tablet press. After pressing and crushing into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0068] The dosage of the anionic surfactant sodium N-dodecylsarcosinate is 45 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the molar ratio of the precipitant urea to the active metal calculated as oxide in the desulfurization adsorbent is 10:1.

[0069] Example 6

[0070] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0071] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0072] Add the mixture I and II into another beaker simultaneously, and add 4 g of sodium dodecylbenzenesulfonate, 2.7 g of n-pentanol and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixture III.

[0073] Transfer mixture III into a 1000 mL polytetrafluoroethylene autoclave, and carry out dynamic crystallization at 80 °C and 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0074] Transfer the above powder to a muffle furnace and calcine it in an air atmosphere at 500 °C for 8 h to obtain a composite metal oxide desulfurization adsorbent S6, where the heating rate is 2 °C / min.

[0075] The composite metal oxide desulfurization adsorbent S6 is pressed on a powder tablet press. After pressing and crushing it into 20-40 mesh particles, it can be used for flue gas desulfurization reaction.

[0076] The dosage of the anionic surfactant sodium dodecylbenzenesulfonate is 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide is 10:1.

[0077] Example 7

[0078] Prepare a 200 mL mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixed solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0079] Prepare a 200 mL aqueous urea solution, denoted as mixed solution II. Among them, the urea concentration is 10 mol / L.

[0080] Add mixed solution I and II to another beaker simultaneously, and add 4 g of sodium dodecylbenzenesulfonate, 2.7 g of n-pentanol, and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixed solution III.

[0081] Transfer mixed solution III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and react at 140 °C and 60 rpm for 12 h. Then, centrifuge and wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an 85 °C oven and then ground into powder.

[0082] Transfer the above powder to a muffle furnace and calcine it in an air atmosphere at 500 °C for 8 h to obtain a composite metal oxide desulfurization adsorbent S7, where the heating rate is 2 °C / min.

[0083] The composite metal oxide desulfurization adsorbent S7 is pressed on a powder tablet press. After pressing and crushing it into 20-40 mesh particles, it can be used for flue gas desulfurization reaction.

[0084] The dosage of the anionic surfactant sodium dodecylbenzenesulfonate is 45 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the molar ratio of the precipitant urea to the active metal calculated as oxide in the desulfurization adsorbent is 10:1.

[0085] Example 8

[0086] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixed solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0087] Prepare 200 mL of an aqueous urea solution, denoted as mixed solution II. Among them, the concentration of urea is 10 mol / L.

[0088] Add mixed solution I and mixed solution II into another beaker simultaneously, and add 1.8 g of sodium dodecylbenzenesulfonate, 1.8 g of n-pentanol, and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixed solution III.

[0089] Transfer mixed solution III to a 1000 mL polytetrafluoroethylene autoclave, and perform dynamic crystallization at 120 °C and a rotation speed of 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0090] Then transfer the powder to a muffle furnace and calcine it at 500 °C for 8 h in an air atmosphere to obtain the composite metal oxide desulfurization adsorbent S8, where the heating rate is 2 °C / min.

[0091] The composite metal oxide desulfurization adsorbent S8 is pressed on a powder tablet press. After pressing and crushing it into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0092] The dosage of the anionic surfactant sodium dodecylbenzenesulfonate is 20 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the dosage of the co-surfactant n-pentanol is 20 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the molar ratio of the precipitant urea to the active metal calculated as oxide in the desulfurization adsorbent is 10:1.

[0093] Example 9

[0094] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0095] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0096] Add mixture I and mixture II simultaneously into another beaker, and simultaneously add 5.3 g of sodium dodecylbenzenesulfonate, 5.3 g of n-pentanol, and 300 g of n-hexane, and stir for 0.5 h at room temperature to obtain mixture III.

[0097] Transfer mixture III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and perform dynamic crystallization at 120 °C and a rotation speed of 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0098] Transfer the powder to a muffle furnace and calcine it in an air atmosphere at 500 °C for 8 h to obtain the composite metal oxide desulfurization adsorbent S9, where the heating rate is 2 °C / min.

[0099] The composite metal oxide desulfurization adsorbent S9 is pressed on a powder tablet press. After pressing and crushing it into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0100] The dosage of the anionic surfactant sodium dodecylbenzenesulfonate is 60 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the dosage of the co-surfactant n-pentanol is 60 wt% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; the molar ratio of the precipitant urea to the active metal in the desulfurization adsorbent calculated as the oxide is 10:1.

[0101] Example 10

[0102] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0103] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0104] Add mixture I and mixture II into another beaker simultaneously, and add 4 g of polyethylene glycol octyl phenyl ether, 2.7 g of n-pentanol and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixture III.

[0105] Transfer mixture III into a 1000 mL polytetrafluoroethylene autoclave, and carry out dynamic crystallization at 120 °C and 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0106] Transfer the powder into a muffle furnace and calcine it at 500 °C for 8 h in an air atmosphere to obtain the composite metal oxide desulfurization adsorbent S10, where the heating rate is 2 °C / min.

[0107] The composite metal oxide desulfurization adsorbent S10 is pressed on a powder tablet press. After pressing and crushing it into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0108] The dosage of polyethylene glycol octyl phenyl ether is 45 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the dosage of n-pentanol is 30 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the molar ratio of urea to the active metal calculated as oxide in the desulfurization adsorbent is 10:1.

[0109] Example 11

[0110] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate and iron nitrate, denoted as mixture I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0111] Prepare 200 mL of an aqueous urea solution, denoted as mixture II. Among them, the concentration of urea is 10 mol / L.

[0112] Add mixture I and mixture II into another beaker simultaneously, and add 4 g of sodium dodecylbenzenesulfonate, 2.7 g of n-hexanol and 300 g of n-hexane at the same time. Stir for 0.5 h at room temperature to obtain mixture III.

[0113] Transfer mixture III into a 1000 mL polytetrafluoroethylene autoclave, and carry out dynamic crystallization at 120 °C and 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C and then ground into powder.

[0114] The powder was then transferred to a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere to obtain a composite metal oxide desulfurization adsorbent S11, with a heating rate of 2 °C / min.

[0115] The composite metal oxide desulfurization adsorbent S11 was pressed on a powder tablet press. After pressing and crushing into 20 - 40 mesh particles, it can be used for flue gas desulfurization reaction.

[0116] The dosage of anionic surfactant sodium dodecylbenzenesulfonate was 45 wt% of the weight of the active metal in the desulfurization adsorbent calculated as oxide; the dosage of n - hexanol was 30 wt% of the weight of the active metal in the desulfurization adsorbent calculated as oxide; the molar ratio of precipitant urea to the active metal in the desulfurization adsorbent calculated as oxide was 10:1.

[0117] Example 12

[0118] A mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate with a volume of 200 mL was prepared and denoted as mixed solution I. Among them, the concentration of magnesium nitrate was 0.7425 mol / L, the concentration of copper nitrate was 0.0075 mol / L, the concentration of aluminum nitrate was 0.21 mol / L, and the concentration of iron nitrate was 0.04 mol / L.

[0119] A urea aqueous solution with a volume of 200 mL was prepared and denoted as mixed solution II. Among them, the concentration of urea was 10 mol / L.

[0120] Mixed solution I and mixed solution II were simultaneously added to another beaker, and 4 g of sodium dodecylbenzenesulfonate, 2.7 g of n - pentanol, and 300 g of ethyl acetate were added simultaneously. The mixture was stirred at room temperature for 0.5 h to obtain mixed solution III.

[0121] Mixed solution III was transferred to a 1000 mL polytetrafluoroethylene high - pressure reaction kettle and dynamically crystallized at 120 °C and a rotation speed of 60 rpm for 12 h. Then, centrifugal separation was carried out, and it was washed with deionized water until neutral, and finally washed once with ethanol. The obtained solid was dried overnight in an 85 °C oven and then ground into powder.

[0122] The powder was then transferred to a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere to obtain a composite metal oxide desulfurization adsorbent S12, with a heating rate of 2 °C / min.

[0123] The composite metal oxide desulfurization adsorbent S12 was pressed on a powder tablet press. After pressing and crushing into 20 - 40 mesh particles, it can be used for flue gas desulfurization reaction.

[0124] The dosage of the anionic surfactant sodium dodecylbenzenesulfonate is 45 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the dosage of the co-surfactant n-pentanol is 30 wt% of the weight of the active metal calculated as oxide in the desulfurization adsorbent; the molar ratio of the precipitant urea to the active metal calculated as oxide in the desulfurization adsorbent is 10:1.

[0125] Comparative Example 1

[0126] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as Mixed Solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0127] Prepare 200 mL of an aqueous urea solution, denoted as Mixed Solution II. Among them, the concentration of urea is 10 mol / L.

[0128] Add Mixed Solution I and II into another beaker simultaneously, and stir for 0.5 h at room temperature to obtain Mixed Solution III.

[0129] Transfer Mixed Solution III to a 1000 mL polytetrafluoroethylene high-pressure reactor, and react at 120 °C and a rotation speed of 60 rpm for 12 h. Then, perform centrifugal separation, wash with deionized water until neutral, and finally wash once with ethanol. The obtained solid is dried overnight in an oven at 85 °C, and then ground into powder.

[0130] Transfer the above powder to a muffle furnace, and calcine in an air atmosphere at 500 °C for 8 h to obtain the composite metal oxide desulfurization adsorbent R3, where the heating rate is 2 °C / min.

[0131] The composite metal oxide desulfurization adsorbent R3 is pressed on a powder tablet press, and after pressing and crushing into 20 - 40 mesh particles, it can be used for the flue gas desulfurization reaction.

[0132] Comparative Example 2

[0133] Prepare 200 mL of a mixed aqueous solution of magnesium nitrate, copper nitrate, aluminum nitrate, and iron nitrate, denoted as Mixed Solution I. Among them, the concentration of magnesium nitrate is 0.7425 mol / L, the concentration of copper nitrate is 0.0075 mol / L, the concentration of aluminum nitrate is 0.21 mol / L, and the concentration of iron nitrate is 0.04 mol / L.

[0134] Prepare an aqueous solution of sodium hydroxide and sodium carbonate 200 mL, denoted as Mixed Solution II. Among them, the concentration of the sodium hydroxide solution is 2 mol / L, and the concentration of the sodium carbonate solution is 0.5 mol / L.

[0135] The mixture I and II were simultaneously added to another beaker at a certain dropping rate and stirred rapidly. The dropping rate of the mixture I was 40 mL / h, and the pH value of the reaction system was maintained at 9 - 10 during the dropping process. After the dropping was completed, the mixture III was obtained.

[0136] The mixture III was transferred into a 1000 mL polytetrafluoroethylene high-pressure reactor and reacted for 12 h under the conditions of 120 °C and a rotation speed of 60 rpm. Then, it was centrifuged and washed with deionized water until neutral, and finally washed once with ethanol. The obtained solid was dried overnight in an oven at 85 °C and then ground into powder.

[0137] The above powder was transferred into a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere to obtain the composite metal oxide desulfurization adsorbent R4, where the heating rate was 2 °C / min.

[0138] The composite metal oxide desulfurization adsorbent R4 was pressed on a powder tablet press. After being pressed and crushed into particles of 20 - 40 mesh, it could be used for the flue gas desulfurization reaction.

[0139] Example of activity evaluation:

[0140] The composition of the inlet raw material gas in this experiment is shown in Table 1, and the space velocity of the desulfurization reaction is 500 h -1 , and the desulfurization activity evaluation was carried out under the condition that the reaction temperature was 500 °C.

[0141] Table 1

[0142]

[0143] At the beginning of the evaluation experiment, first weigh 0.8 g of the desulfurization adsorbent (examples and comparative examples) with a particle size of 20 - 40 mesh. It was uniformly loaded into a fixed-bed micro-reactor according to certain rules, and the upper and lower layers were fixed with quartz wool respectively, and 2 g of quartz sand was weighed to dilute the desulfurization adsorbent.

[0144] During the evaluation process, the inlet gas flow rate and SO2 content were controlled by a mass flow meter, and the SO2 content in the outlet gas was detected by a QGA quantitative gas analysis mass spectrometer of Hiden Company in the UK. By measuring parameters such as the SO2 content C 进 、C 出 , the space velocity of the reaction, and the desulfurization reaction time, etc., the desulfurization performance of the composite metal oxide desulfurization adsorbent was comprehensively evaluated. When the SO2 content in the reactor outlet was higher than 100 ppm, it was defaulted that the desulfurization adsorbent was deactivated. At this time, the sulfur capacity of the desulfurization adsorbent was called the breakthrough sulfur capacity, and the sulfur capacity was calculated by the following formula:

[0145]

[0146] Among them, S - breakthrough sulfur capacity;

[0147] m s —— The mass of SO2 adsorbed on the desulfurization adsorbent during the evaluation test;

[0148] M —— The mass of the loaded catalyst;

[0149] C 进 、C 出 —— The content of SO2 at the inlet and outlet of the experimental device, g / m 3 ;

[0150] S y —— The mass space velocity of the reaction gas during the experiment, h -1 ;

[0151] t —— The time required for breakthrough in the test, h.

[0152] After adsorption saturation, switch to a regeneration gas stream of 10% H2 / N2, and the regeneration reaction temperature is 500 °C. When no sulfur-containing gas can be detected in the regeneration gas stream, the regeneration ends and enters the next adsorption stage. After the regenerated gas (SO2, H2S, S) is condensed and separated to obtain liquid sulfur, it can be returned to the Claus sulfur recovery unit to further recover sulfur resources.

[0153] The initial breakthrough sulfur capacity of the samples in the examples and comparative examples (the breakthrough sulfur capacity when the desulfurization adsorbent is initially tested, without undergoing regeneration) performance is shown in Table 2.

[0154] Table 2

[0155] Desulfurization adsorbent <![CDATA[Initial sulfur breakthrough capacity (gSO2 / gcat.)]]> Example 1 1.26 Example 2 1.25 Example 3 1.26 Example 4 1.19 Example 5 1.23 Example 6 1.15 Example 7 1.24 Example 8 1.16 Example 9 1.23 Example 10 1.19 Example 11 1.21 Example 12 1.18 Comparative Example 1 1.11 Comparative Example 2 1.12

[0156] Note: cat. is the desulfurization adsorbent.

[0157] Compared with sodium dodecylbenzenesulfonate and sodium N-dodecylsarcosinate, stearic acid will react with the base to form the corresponding salt under alkaline conditions, that is, consume OH in the reaction system - , thereby affecting the pH value of the reaction system. Therefore, Examples 1 and 3 are slightly better than Example 2.

[0158] Too low dosages of surfactant and co-surfactant will lead to a decrease in the adsorption amount at the two-phase interface, relatively large interfacial tension, and unstable microemulsion; while too high dosages may lead to excessive emulsification, too small droplet size, and affect the stability of the microemulsion. Therefore, Example 1 is better than Examples 8 and 9.

[0159] The hydrothermal reaction temperature and reaction time will affect the crystallinity of the crystal. The crystallinity gradually increases with the increase of temperature and time and then gradually remains unchanged. Therefore, Examples 1, 5, and 7 are all slightly better than Examples 4 and 6.

[0160] Polyethylene glycol p - isooctylphenyl ether is a non - ionic surfactant. Compared with anionic surfactants such as sodium dodecylbenzenesulfonate, stearic acid, and sodium N - dodecylsarcosinate, the positively charged composite metal hydroxide crystal nucleus lamella does not have electrostatic interaction, and thus will not adsorb around the head of the anionic surfactant and self - assemble, nor affect the morphology and specific surface area of the crystals in the group. Therefore, Examples 1, 2, and 3 are superior to Example 10.

[0161] For a single surfactant, the critical saturation concentration is reached before the interfacial tension drops to zero. Adding a co - surfactant can further reduce the interfacial tension. At this time, the interfacial expansion generates intact droplets, resulting in more surfactants and co - surfactants adsorbing at the interface, thus greatly reducing the concentrations of the surfactant and co - surfactant in the system solution, and the interfacial tension becomes positive again, forming a microemulsion. The type of co - surfactant will affect the amplitude of the interfacial tension reduction. Among them, compared with n - pentanol, the interaction of n - hexanol is relatively weak. Therefore, Example 1 is superior to Example 11.

[0162] During the synthesis of inverse microemulsion, the nucleation and growth of nanoparticles occur within the water cores protected by surfactants. The size of the water cores determines the final particle size of the nanoparticles, and the properties of the oil phase, the type of surfactant, the addition amount of surfactant, and the reaction temperature will all affect the size of the water cores. Compared with ethyl acetate, the water cores formed by C6 - C8 straight - chain alkanes or cycloalkanes are relatively small, and the size of the final crystal grains is relatively small. Therefore, Example 1 is superior to Example 12.

Claims

1. A preparation method of a desulfurization adsorbent, characterized in that, It includes the following steps: Mix an aqueous solution containing at least two active metal component precursor salts, an aqueous solution of a precipitant, an organic solvent, an anionic surfactant, and a co-surfactant in a closed system and then perform dynamic crystallization; and wash, dry, grind, calcine, and granulate the precipitate obtained from the dynamic crystallization reaction to obtain the desulfurization adsorbent; The first active metal component precursor salt is selected from one or more of Mg salts, Ca salts, Sr salts, Ni salts, Zn salts, Cu salts, and Mn salts; the second active metal component precursor salt is selected from one or more of Al salts, Fe salts, Ce salts, Cr salts, La salts, Co salts, and V salts; the molar ratio of the metal element in the first active metal component precursor salt to the metal element in the second active metal component precursor salt is 1:0.1 - 0.

5.

2. The preparation method of the desulfurization adsorbent according to claim 1, wherein, The anionic surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium hexadecylsulfonate, lauric acid, stearic acid, oleic acid, sodium dodecylaminopropionate, and sodium N-dodecylsarcosinate.

3. The preparation method of the desulfurization adsorbent according to claim 2, wherein, The co-surfactant is selected from one or more of ethylamine, n-propylamine, isopropylamine, n-propylamine, isopropylamine, n-pentylamine, isopentylamine, n-hexylamine, 2-ethylhexylamine, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, n-hexanol, and 2-hexanol.

4. The preparation method of the desulfurization adsorbent according to claim 1 or 2, characterized in that, The organic solvent is selected from one or more of pentane, hexane, octane, cyclopentane, cyclohexane, and cyclooctane.

5. The preparation method of the desulfurization adsorbent according to claim 1 or 2, characterized in that, The precipitant is selected from one or more of urea, sodium hydroxide, and sodium carbonate.

6. The preparation method of the desulfurization adsorbent according to claim 1, characterized in that, The dosage of the anionic surfactant is 20 - 60% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; Preferably, the dosage of the co-surfactant is 20 - 60% of the weight of the active metal in the desulfurization adsorbent calculated as the oxide; Preferably, the molar ratio of the precipitant to the active metal in the desulfurization adsorbent calculated as the oxide is 5 - 15:

1.

7. The preparation method of the desulfurization adsorbent according to claim 1, wherein, The crystallization temperature of the dynamic crystallization is 80 - 150 °C, and the dynamic rotation speed is 50 - 100 rpm.

8. The preparation method of the desulfurization adsorbent according to claim 1, characterized in that, The temperature of the calcination is 400 - 700 °C, and the time is 5 - 12 h; Preferably, the particle size of the desulfurization adsorbent obtained by granulation is 10 - 40 mesh.

9. A desulfurization adsorbent, characterized in that, It is prepared by the preparation method of the desulfurization adsorbent according to any one of claims 1 to 8.

10. An application of the desulfurization adsorbent according to claim 9 in flue gas desulfurization.

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