Preparation method and regeneration process of renewable aerogel desulfurizer

Abstract

The application discloses a preparation method and a regeneration process of a renewable aerogel desulfurizer, and belongs to the technical field of coal chemical desulfurizer preparation. The preparation method comprises the following steps: carrying out a hydrothermal reaction on a silicon dioxide nanofiber aerogel carrier in a mixed solution of zinc nitrate and cobalt nitrate, generating an active component ZnCo2O4 in the silicon dioxide nanofiber aerogel carrier, and obtaining a desulfurizer precursor; and carrying out an oxidation treatment on the desulfurizer precursor under a microwave field, and obtaining the renewable aerogel desulfurizer. The desulfurizer preparation process route is simple and easy to implement, the desulfurizer regeneration process is high in efficiency, low in energy consumption, and excellent in desulfurizer regeneration performance, and can meet the performance requirements of desulfurizer industrialization; on the other hand, the flexible and high-porosity fiber material is used as a carrier to construct a multi-level micro-pore structure of the desulfurizer, so that the adsorption capacity and desulfurization reaction activity of the desulfurizer can be improved.

Description

Technical Field

[0001] This invention relates to the field of coal chemical desulfurization agent preparation technology, and in particular to a method for preparing and regenerating a regenerable aerogel desulfurization agent. Background Technology

[0002] As one of the three major fossil fuels, coal's fundamental energy importance in economic development is unshakeable. However, the various environmental problems caused by the direct combustion of coal cannot be ignored. Integrated gasification combined cycle (IGCC) power generation technology, based on the clean and efficient utilization of coal, has been widely adopted in many countries and regions. Coal gas, as the power and feedstock source in IGCC technology, contains a large amount of sulfides, more than 90% of which is hydrogen sulfide (H2S). Hydrogen sulfide not only corrodes industrial equipment and poisons catalysts, but also poses a threat to the ecological environment and human health when released into the atmosphere. Therefore, hydrogen sulfide must be completely removed from coal gas before use.

[0003] Dry desulfurization utilizes metal oxides in solid-phase desulfurizing agents to convert and remove H2S through chemical reactions. This method has advantages such as simple process flow, no wastewater or waste acid treatment issues, low energy consumption, low equipment corrosivity, and low cost. Studies have shown that desulfurizing agents with zinc oxide as the active component have higher desulfurization precision and efficiency than other oxide desulfurizing agents. However, zinc oxide is prone to volatilization during high-temperature regeneration, leading to loss of active components and severe performance degradation. Copper oxide has a strong affinity and adsorption capacity for hydrogen sulfide. Some researchers have found that copper oxide desulfurizing agents have high desulfurization precision, are less affected by temperature, and have good regeneration performance.

[0004] However, current dry desulfurization technologies suffer from drawbacks such as large desulfurizing agent loading, frequent agent replacement, difficulty in regenerating spent desulfurizing agents, and challenges in solid waste treatment. While existing desulfurizing agent preparation methods and regeneration processes are relatively mature, they still suffer from drawbacks such as high regeneration temperatures, difficulty in regeneration leading to short service life, and high operating costs. Therefore, existing desulfurizing agents cannot meet the requirements of practical industrial applications, and developing novel, highly efficient, and regenerable solid desulfurizing agents with high desulfurization efficiency, speed, and selectivity remains one of the goals of gas desulfurization technology. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing and regenerating a regenerable aerogel desulfurizer, in order to solve the problems of low utilization rate of active components and poor sulfidation-regeneration performance of the desulfurizer during the reaction process, and ultimately improve the sulfidation and recycling performance of the desulfurizer.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of the present invention is a method for preparing a renewable aerogel desulfurizer, comprising the following steps: a silica nanofiber aerogel carrier is subjected to a hydrothermal reaction in a mixed solution of zinc nitrate and cobalt nitrate to generate an active component ZnCo2O4 in the silica nanofiber aerogel carrier, thereby obtaining a desulfurizer precursor; the desulfurizer precursor is subjected to oxidation treatment under a microwave field to obtain the renewable aerogel desulfurizer.

[0008] Furthermore, the porosity of the silica nanofiber aerogel carrier is 95-99.99%, and the diameter of the silica nanofibers is 100-1000 nm.

[0009] Furthermore, the molar ratio of zinc nitrate to cobalt nitrate in the mixed solution is 1:1-4, and the concentration of zinc nitrate is 0.1 mol / L.

[0010] Furthermore, the hydrothermal reaction is carried out at a temperature of 80-110°C for a duration of 1-4 hours.

[0011] Furthermore, in the hydrothermal reaction process, the ratio of silica nanofiber aerogel carrier to the mixed solution of zinc nitrate and cobalt nitrate is 0.4 g: 100 mL. The active component ZnCo2O4 is generated during the hydrothermal reaction.

[0012] Furthermore, the microwave field has a microwave condition of 1000W.

[0013] Furthermore, the specific parameters of the oxidation treatment include: an oxygen concentration of 1-4 vol%, a calcination temperature of 200-350℃, and a calcination time of 1 h.

[0014] The second technical solution of the present invention: a renewable aerogel desulfurizer prepared by the above preparation method.

[0015] Furthermore, the renewable aerogel desulfurizer uses silica nanofiber aerogel as a carrier, and the carrier is loaded with the active component ZnCo2O4, which can be called ZnCo2O4 / silica nanofiber aerogel composite desulfurizer.

[0016] Furthermore, the ZnCo2O4 content in the renewable aerogel desulfurizer is 56.6-57.9 wt%.

[0017] The third technical solution of the present invention: a method for regenerating the above-mentioned regenerable aerogel desulfurizer, comprising the following steps: soaking the regenerable aerogel desulfurizer after the desulfurization reaction in NaF solution for 12 hours, drying it, and then placing it under a microwave field, and sequentially introducing hydrogen, argon and oxygen for heat treatment to obtain the regenerated desulfurizer.

[0018] Furthermore, the renewable aerogel desulfurizer after the desulfurization reaction is specifically a renewable aerogel desulfurizer that has been saturated with H2S, that is, the desulfurization reaction is carried out until the renewable aerogel desulfurizer is saturated.

[0019] Furthermore, the concentration of the NaF solution is 1-4 mmol / L.

[0020] Furthermore, the concentration of hydrogen is 2-8 vol%, the concentration of oxygen is 1-4 vol%, and the equilibrium gas when hydrogen and oxygen are introduced is nitrogen. That is, when hydrogen is introduced, a mixture of hydrogen and nitrogen is introduced, and when oxygen is introduced, a mixture of oxygen and nitrogen is introduced.

[0021] Furthermore, the argon gas is pure argon gas.

[0022] Furthermore, the microwave field has a microwave condition of 1000W.

[0023] Furthermore, the heat treatment temperature for hydrogen gas is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon gas is 500℃ and the heat treatment time is 30 min; and the heat treatment temperature for oxygen gas is 400℃ and the heat treatment time is 2 h.

[0024] The first two gases generate plasma under the action of a microwave field, which modifies the surface and bulk phase of the desulfurized agent, making it more chemically active and easier to undergo chemical reactions; the role of oxygen is to regenerate the desulfurized agent.

[0025] Furthermore, the specific operation of the desulfurization reaction is as follows: the renewable aerogel desulfurizing agent is placed in a fixed-bed reactor and reacted at a rate of 2000 h⁻¹. -1 Gas is introduced at air velocity and desulfurization reaction is carried out at 500℃.

[0026] The present invention discloses the following technical effects:

[0027] This invention utilizes silica nanofiber aerogel as a carrier to prepare a ZnCo2O4 / silica nanofiber aerogel composite desulfurizer through hydrothermal reaction with metal salt solution and oxidation treatment. It possesses the following advantages:

[0028] (1) The present invention uses nanofiber aerogel as a carrier to prepare desulfurizer. By utilizing the open pore structure, high flexibility and stable physical structure of nanofiber aerogel, it can not only provide support for the overall structure of desulfurizer, but also promote the adsorption and reaction process of H2S and maintain the long-term cyclic use performance of desulfurizer.

[0029] (2) The process steps of the present invention are simple, highly controllable, and easy to operate, which can meet the large market demand. The nanofiber aerogel has good support, high flexibility, high toughness and strength, high porosity and large specific surface area, and can realize multi-component composite and multi-level structure synergy.

[0030] (3) More importantly, this invention combines zinc and cobalt, which not only forms a composite oxide, improving the stability of zinc and the regeneration performance of the desulfurizer, but also reduces the stability of the composite oxide's lattice structure based on the size difference between zinc and cobalt ions. Furthermore, by utilizing the lattice diffusion of zinc and cobalt ions during the low-temperature oxidation process and the promoting effect of microwave radiation on metal ion migration, a significant Kirkendall effect is generated, leading to a large number of lattice defects (metal ion defects and oxygen vacancies) in the zinc-cobalt composite oxide, even transforming it into a hollow structure. During the desulfurizer regeneration process, the addition of fluorine through soaking in NaF solution allows for a tight bond with the metal, weakening the metal-sulfur chemical bond. Simultaneously, hydrogen and argon generate plasma under microwave radiation, which can treat surface defects in the adsorbed desulfurizer, generating a large number of sulfur vacancies (such as...). Figure 1 (As shown). Based on this, the lattice defects and surface defects contained in the desulfurizer are beneficial to the adsorption and dissociation of oxygen during the oxidation regeneration process. They also help to weaken the chemical bonds between metal and sulfur, reduce the activation energy of bond breaking, and thus lower the regeneration reaction temperature. This reduces the diffusion resistance of oxygen and sulfur ions, allowing the desulfurizer to avoid the adverse effects of high-temperature sintering, maintain a high gas-solid reaction rate and mass transfer efficiency, and improve the recyclability of the desulfurizer. Tests show that the desulfurizer prepared by the method of this invention not only achieves a sulfur capacity of 28.3% and an active component utilization rate of 99.9%, but also reduces the oxidation regeneration reaction temperature to 400℃ when the desulfurizer regeneration rate reaches 99.0%. After ten sulfurization-regeneration cycles, the sulfur capacity of the regenerated desulfurizer can still reach 28.2%. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a comparison of the sulfur vacancy concentrations before and after the desulfurizing agent in Example 1, after absorption saturation, was soaked in NaF solution and subjected to heat treatment with hydrogen and argon gas. Detailed Implementation

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0036] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0037] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0038] The silica nanofiber aerogel carriers used in the following examples and comparative examples have a porosity of 99%, and the average diameter of the silica nanofibers is 500 nm. Silica nanofiber aerogel carriers are commercially available or can be prepared using conventional methods, such as airflow-assisted electrospinning, nanofiber remodeling, and freeze-drying to prepare silica nanofiber aerogels from SiO2. Specific preparation details are not limited, as long as the requirements for porosity and average nanofiber diameter are met. Specific preparation details do not affect the technical effectiveness of this solution.

[0039] The testing and calculation methods for sulfur capacity, active component utilization rate, and desulfurizer regeneration rate in the following examples and comparative examples are as follows:

[0040] The desulfurization performance of the samples was evaluated using breakthrough sulfur capacity as the indicator. The H2S concentration in the inlet gas was 1000 ppm. When the H2S concentration in the outlet gas reached 300 ppm, it was considered that the desulfurizing agent had broken through; the time taken for this to occur was considered the breakthrough time. Breakthrough sulfur capacity is converted into the mass (g) of elemental sulfur absorbed by 100g of desulfurizing agent from the start of the experiment until the breakthrough time. The detailed calculation method is as follows:

[0041]

[0042] Where: F is the flow rate of the simulated gas (mL / min), M s The molar mass of S is 32.06 g / mol, and the molar mass of V is V. m The molar volume of the gas at 25℃ and 101.325 kPa is 24.5 L / mol; C0 and C represent the inlet and outlet concentrations of H2S (ppm), respectively; M 脱硫剂 Corresponding to the mass (g) of the desulfurizing agent.

[0043] Utilization rate of active components = actual sulfur capacity / theoretical sulfur capacity × 100%.

[0044] Regeneration rate = (mass of desulfurizer lost during regeneration / mass of desulfurizer increased during desulfurization reaction) × 100%.

[0045] Example 1

[0046] (1) The preparation of renewable aerogel desulfurizer is as follows:

[0047] 1) Preparation of desulfurizing agent precursor: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 11.64 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.04 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as a hydrothermal reaction solution; a silica nanofiber aerogel carrier was subjected to a hydrothermal reaction in the hydrothermal reaction solution (the ratio of silica nanofiber aerogel to hydrothermal reaction solution was 0.4 g: 100 mL), the hydrothermal reaction temperature was 80 °C and the time was 1 h. During the hydrothermal reaction, the active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier. After the hydrothermal reaction was completed, the desulfurizing agent precursor was obtained by drying.

[0048] 2) Preparation of desulfurizing agent: The desulfurizing agent precursor obtained in step 1) is oxidized under a microwave field of 1000W (a mixed gas with an oxygen concentration of 1 vol% is introduced, the equilibrium gas is nitrogen, and it is calcined at 200℃ for 1 h) to obtain a renewable aerogel desulfurizing agent (the content of ZnCo2O4 in the desulfurizing agent is 57.9 wt%).

[0049] (2) Application of desulfurizing agent: The desulfurizing agent (0.1g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0050] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 28.3%, and the utilization rate of the active component was 99.9%.

[0051] (3) Regeneration of desulfurizing agent: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is soaked in a 1 mmol / L NaF solution for 12 h. After drying, it is subjected to heat treatment under a microwave field of 1000 W by sequentially introducing a mixed gas with a hydrogen concentration of 2 vol% (2 vol% hydrogen + 98 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 1 vol% (1 vol% oxygen + 99 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h. The space velocity is 2000 h⁻¹. -1 The desulfurizing agent is then fully regenerated. This regenerated agent is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is complete, regeneration is performed again under the same conditions.

[0052] After ten cycles of sulfidation / regeneration, the desulfurizing agent showed a regeneration rate of 99.0% and a sulfur capacity of 28.2%.

[0053] Figure 1 This example compares the sulfur vacancy concentrations of the desulfurizing agent after absorption saturation in NaF solution and subsequent heat treatment with hydrogen and argon gas. The sample before modification represents the desulfurization reaction to absorption saturation, while the sample after modification represents the desulfurizing agent after absorption saturation, soaked in NaF solution and heat treated with hydrogen and argon gas. Figure 1 It can be seen that the concentration of sulfur vacancies in the sample increases after soaking in NaF solution and heat treatment with hydrogen and argon.

[0054] Example 2

[0055] (1) The preparation of renewable aerogel desulfurizer is as follows:

[0056] 1) Preparation of desulfurizing agent precursor: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 8.73 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.03 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as a hydrothermal reaction solution; a silica nanofiber aerogel carrier was subjected to a hydrothermal reaction in the hydrothermal reaction solution (the ratio of silica nanofiber aerogel to hydrothermal reaction solution was 0.4 g: 100 mL), the hydrothermal reaction temperature was 90 °C and the time was 1 h. During the hydrothermal reaction, the active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier. After the hydrothermal reaction was completed, the desulfurizing agent precursor was obtained by drying.

[0057] 2) Preparation of desulfurizing agent: The desulfurizing agent precursor obtained in step 1) is oxidized under a microwave field of 1000W (a mixed gas with an oxygen concentration of 2 vol% is introduced, the equilibrium gas is nitrogen, and it is calcined at 250℃ for 1 h) to obtain a renewable aerogel desulfurizing agent (the content of ZnCo2O4 in the desulfurizing agent is 57.3 wt%).

[0058] (2) Application of desulfurizing agent: The desulfurizing agent (0.1g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0059] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 27.9%, and the utilization rate of the active component was 99.6%.

[0060] (3) Regeneration of desulfurizing agent: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is soaked in a 2 mmol / L NaF solution for 12 h. After drying, it is subjected to heat treatment under a microwave field of 1000 W by sequentially introducing a mixed gas with a hydrogen concentration of 4 vol% (4 vol% hydrogen + 96 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h; the space velocity is 2000 h⁻¹. -1 The desulfurizing agent is then fully regenerated. This regenerated agent is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is complete, regeneration is performed again under the same conditions.

[0061] After ten cycles of sulfidation / regeneration, the desulfurizer's regeneration rate was 96% and its sulfur capacity was 27.6%.

[0062] Example 3

[0063] (1) The preparation of renewable aerogel desulfurizer is as follows:

[0064] 1) Preparation of desulfurizing agent precursor: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 5.82 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.02 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as the hydrothermal reaction solution; a silica nanofiber aerogel carrier was subjected to a hydrothermal reaction in the hydrothermal reaction solution (the ratio of silica nanofiber aerogel to hydrothermal reaction solution was 0.4 g: 100 mL), the hydrothermal reaction temperature was 100℃ and the time was 1 h. During the hydrothermal reaction, the active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier. After the hydrothermal reaction was completed, the desulfurizing agent precursor was obtained by drying.

[0065] 2) Preparation of desulfurizing agent: The desulfurizing agent precursor obtained in step 1) is oxidized under a microwave field of 1000W (a mixed gas with an oxygen concentration of 3 vol% is introduced, the equilibrium gas is nitrogen, and it is calcined at 300℃ for 1 h) to obtain a renewable aerogel desulfurizing agent (the desulfurizing agent contains 57.0 wt% ZnCo2O4).

[0066] (2) Application of desulfurizing agent: The desulfurizing agent (0.1g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0067] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 27.5%, and the utilization rate of the active component was 98.6%.

[0068] (3) Regeneration of desulfurizing agent: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is soaked in a 3 mmol / L NaF solution for 12 h. After drying, it is subjected to heat treatment under a microwave field of 1000 W by sequentially introducing a mixed gas with a hydrogen concentration of 6 vol% (6 vol% hydrogen + 94 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 3 vol% (3 vol% oxygen + 97 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h. The space velocity is 2000 h⁻¹. -1 The desulfurizing agent is then fully regenerated. This regenerated agent is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is complete, regeneration is performed again under the same conditions.

[0069] After ten cycles of sulfidation / regeneration, the desulfurizer's regeneration rate was 92% and its sulfur capacity was 27.0%.

[0070] Example 4

[0071] (1) The preparation of renewable aerogel desulfurizer is as follows:

[0072] 1) Preparation of desulfurizing agent precursor: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 2.91 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.01 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as a hydrothermal reaction solution; a silica nanofiber aerogel carrier was subjected to a hydrothermal reaction in the hydrothermal reaction solution (the ratio of silica nanofiber aerogel to hydrothermal reaction solution was 0.4 g: 100 mL), the hydrothermal reaction temperature was 110 °C and the time was 1 h. During the hydrothermal reaction, the active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier. After the hydrothermal reaction was completed, the desulfurizing agent precursor was obtained by drying.

[0073] 2) Preparation of desulfurizing agent: The desulfurizing agent precursor obtained in step 1) is oxidized under a microwave field of 1000W (a mixed gas with an oxygen concentration of 4 vol% is introduced, the equilibrium gas is nitrogen, and it is calcined at 350℃ for 1 h) to obtain a renewable aerogel desulfurizing agent (the content of ZnCo2O4 in the desulfurizing agent is 56.6 wt%).

[0074] (2) Application of desulfurizing agent: The desulfurizing agent (0.1g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0075] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 27.1%, and the utilization rate of the active component was 97.9%.

[0076] (3) Regeneration of desulfurizing agent: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is soaked in a 4 mmol / L NaF solution for 12 h. After drying, it is subjected to heat treatment under a microwave field of 1000 W by sequentially introducing a mixed gas with a hydrogen concentration of 8 vol% (8 vol% hydrogen + 92 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 4 vol% (4 vol% oxygen + 96 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h; the space velocity is 2000 h⁻¹. -1 The desulfurizing agent is then fully regenerated. This regenerated agent is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is complete, regeneration is performed again under the same conditions.

[0077] After ten cycles of sulfidation / regeneration, the desulfurizer's regeneration rate was 89% and its sulfur capacity was 25.8%.

[0078] Comparative Example 1

[0079] Commercially available ZnCo2O4 was used as the active component, and ZnCo2O4 and silica nanofiber aerogel were mechanically mixed at a certain mass ratio (57.9:42.1) to prepare a desulfurizing agent.

[0080] The specific operation of mechanical mixing is as follows: ZnCo2O4 is dispersed in water to prepare a ZnCo2O4 dispersion with a concentration of 0.1 mol / L. Silica nanofiber aerogel is added, and after mechanical stirring for 3 hours, the silica nanofiber aerogel is taken out and dried to obtain a desulfurizing agent (the ZnCo2O4 content in the desulfurizing agent is 57.9 wt%).

[0081] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the mechanically mixed ZnCo2O4 / silica nanofiber aerogel desulfurizer prepared in this comparative example was tested to be 12.3%, and the utilization rate of the active component was 47.6%.

[0082] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the mechanically mixed ZnCo2O4 / silica nanofiber aerogel desulfurizer was 60.1%, and the sulfur capacity decreased to 6.8%.

[0083] In addition, the desulfurizing agent after one desulfurization test was tested in a mixed gas (2 vol% oxygen + 98 vol% nitrogen) with a space velocity of 2000 h⁻¹. -1 Under these conditions, the regeneration reaction temperature that can achieve a 99% regeneration rate is 850℃.

[0084] Comparative Example 2

[0085] Same as Example 1, except that the use of microwave field is omitted in step 2) of the preparation of renewable aerogel desulfurizer, and oxidation treatment is carried out under non-microwave conditions.

[0086] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the desulfurizing agent prepared in this comparative example was tested to be 15.6%, and the utilization rate of the active component was 58.1%.

[0087] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 98.0%, and the sulfur capacity decreased to 12.4%.

[0088] Comparative Example 3

[0089] The preparation steps of the regenerable aerogel desulfurizer are the same as in Example 1, the desulfurization reaction conditions are the same as in Example 1, but the regeneration steps of the desulfurizer are different from those in Example 1.

[0090] The regeneration steps in this comparative example are as follows: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is sequentially heat-treated under a 1000W microwave field by introducing a mixed gas with a hydrogen concentration of 2 vol% (2 vol% hydrogen + 98 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 1 vol% (1 vol% oxygen + 99 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h; the space velocity is 2000 h⁻¹. -1 This process yields fully regenerated desulfurizer. The regenerated desulfurizer is then used in the desulfurization reaction of Texaco simulated coal gas, under the same conditions as above (space velocity 2000 h⁻¹). -1 (Temperature 500℃). After the desulfurization reaction is completed, regeneration is carried out again under the same regeneration conditions.

[0091] After ten cycles of sulfidation / regeneration, the regeneration rate of the desulfurizing agent was 80.1%, and the sulfur capacity was 20.8%.

[0092] Comparative Example 4

[0093] The preparation steps of the regenerable aerogel desulfurizer are the same as in Example 1, the desulfurization reaction conditions are the same as in Example 1, but the regeneration steps of the desulfurizer are different from those in Example 1.

[0094] The regeneration steps in this comparative example are as follows: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is immersed in a 1 mmol / L NaF solution for 12 h. After drying, it is subjected to heat treatment under a 1000 W microwave field by sequentially introducing a mixed gas (1 vol% oxygen + 99 vol% nitrogen) with argon and oxygen concentrations of 1 vol%. The heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h. The space velocity is 2000 h⁻¹ for both cases. -1 This process yields fully regenerated desulfurizer. The regenerated desulfurizer is then used in the desulfurization reaction of Texaco simulated coal gas, under the same conditions as above (space velocity 2000 h⁻¹). -1 (Temperature 500℃). After the desulfurization reaction is completed, regeneration is carried out again under the same regeneration conditions.

[0095] After ten cycles of sulfidation / regeneration, the desulfurizing agent's regeneration rate was 85.7% and its sulfur capacity was 21.2%.

[0096] Comparative Example 5

[0097] The preparation steps of the regenerable aerogel desulfurizer are the same as in Example 1, the desulfurization reaction conditions are the same as in Example 1, but the regeneration steps of the desulfurizer are different from those in Example 1.

[0098] The regeneration steps in this comparative example are as follows: After the desulfurization reaction is completed, the desulfurizing agent saturated with H2S is soaked in a 1 mmol / L NaF solution for 12 h. After drying, it is sequentially heat-treated by introducing a mixed gas with a hydrogen concentration of 2 vol% (2 vol% hydrogen + 98 vol% nitrogen), argon, and a mixed gas with an oxygen concentration of 1 vol% (1 vol% oxygen + 99 vol% nitrogen). The heat treatment temperature for hydrogen is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for argon is 500℃ and the heat treatment time is 30 min; the heat treatment temperature for oxygen is 400℃ and the heat treatment time is 2 h, all under a non-microwave field; the space velocity is 2000 h⁻¹. -1 This process yields fully regenerated desulfurizer. The regenerated desulfurizer is then used in the desulfurization reaction of Texaco simulated coal gas, under the same conditions as above (space velocity 2000 h⁻¹).-1 (Temperature 500℃). After the desulfurization reaction is completed, regeneration is carried out again under the same regeneration conditions.

[0099] After ten cycles of sulfidation / regeneration, the regeneration rate of the desulfurizing agent was 75.5%, and the sulfur capacity was 20.8%.

[0100] Comparative Example 6

[0101] The preparation steps of the regenerable aerogel desulfurizer are the same as in Example 1, the desulfurization reaction conditions are the same as in Example 1, but the regeneration steps of the desulfurizer are different from those in Example 1.

[0102] The regeneration steps in this comparative example are as follows: using a mixed gas with an oxygen volume concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen), at a temperature of 650°C and a space velocity of 2000 h⁻¹. -1 The desulfurizing agent, after being saturated with H2S, was regenerated for 2 hours to obtain regenerated desulfurizing agent. This regenerated desulfurizing agent was then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions (space velocity 2000 h⁻¹). -1 (Temperature 500℃). After the desulfurization reaction is completed, regeneration is carried out again under the same regeneration conditions.

[0103] After ten cycles of sulfidation / regeneration, the regeneration rate of the desulfurizing agent was 66.3%, and the sulfur capacity was 17.6%.

[0104] Comparative Example 7

[0105] Similar to Comparative Example 6, the only difference is that the regeneration temperature was 850℃. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 98%, and the sulfur capacity was 27.1%.

[0106] Comparative Example 8

[0107] Similar to Comparative Example 6, the only difference is that the regeneration temperature was 400℃. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 66.6% and the sulfur capacity was 18.0%.

[0108] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a renewable aerogel desulfurizer, characterized in that, Includes the following steps: A silica nanofiber aerogel carrier is subjected to a hydrothermal reaction in a mixed solution of zinc nitrate and cobalt nitrate to generate the active component ZnCo2O4 in the silica nanofiber aerogel carrier, thus obtaining a desulfurizing agent precursor; the desulfurizing agent precursor is then oxidized under a microwave field to obtain the renewable aerogel desulfurizing agent.

2. The preparation method according to claim 1, characterized in that, The porosity of the silica nanofiber aerogel carrier is 95-99.99%, and the diameter of the silica nanofibers is 100-1000 nm.

3. The preparation method according to claim 1, characterized in that, The molar ratio of zinc nitrate to cobalt nitrate in the mixed solution of zinc nitrate and cobalt nitrate is 1:1-4, and the concentration of zinc nitrate is 0.1 mol / L.

4. The preparation method according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 80-110℃ for 1-4 hours.

5. The preparation method according to claim 1, characterized in that, The microwave field has a microwave condition of 1000W.

6. The preparation method according to claim 1, characterized in that, The specific parameters of the oxidation treatment include: oxygen concentration of 1-4 vol%, calcination temperature of 200-350℃, and calcination time of 1 h.

7. A renewable aerogel desulfurizer prepared by the preparation method according to any one of claims 1-6.

8. A method for regenerating the regenerable aerogel desulfurizer as described in claim 7, characterized in that, Includes the following steps: The regenerable aerogel desulfurizer after desulfurization reaction was soaked in NaF solution for 12 hours, dried, and then placed under a microwave field for heat treatment by sequentially introducing hydrogen, argon, and oxygen to obtain the regenerated desulfurizer.

9. The regeneration method as described in claim 8, characterized in that, The concentration of the NaF solution is 1-4 mmol / L.

10. The regeneration method as described in claim 8, characterized in that, The concentration of hydrogen is 2-8 vol%, the concentration of oxygen is 1-4 vol%, and the equilibrium gas when hydrogen and oxygen are introduced is nitrogen.

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