High-porosity nano zinc oxide desulfurizer and preparation method thereof

Abstract

The invention relates to the technical field of desulfurizing agents, in particular to a high-porosity nano-zinc oxide desulfurizing agent and a preparation method thereof.The high-porosity nano-zinc oxide desulfurizing agent is prepared from, by weight, 55-70 parts of modified nano-zinc oxide, 20-30 parts of binder, 10-15 parts of mesoporous silica and 3-5 parts of rare earth metal oxide. The high-porosity nano zinc oxide desulfurizer prepared by the method has high sulfur capacity, high desulfurization rate and excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of desulfurizing agent technology, specifically to a high-porosity nano zinc oxide desulfurizing agent and its preparation method. Background Technology

[0002] In industrial processes such as coal chemical engineering, natural gas purification, oil refining, and vehicle exhaust treatment, raw materials or products often contain sulfur-containing compounds such as hydrogen sulfide and mercaptans. The hazards of these substances are mainly manifested in equipment corrosion, catalyst poisoning, and environmental pollution. Furthermore, hydrogen sulfide itself is a highly toxic gas, directly threatening human health. Therefore, efficient removal of sulfur compounds from gases is an indispensable and crucial step in industrial production. Traditional desulfurizing agents mainly include activated carbon, iron oxide, zinc oxide, and molecular sieves, but their performance is insufficient to meet the high-efficiency desulfurization requirements of modern industry. With the development of nanomaterials technology, nano-zinc oxide is gradually becoming a highly promising desulfurizing agent.

[0003] Patent CN117563413A discloses a desulfurizing agent for removing hydrogen sulfide from flue gas and its preparation method, including the following steps. The desulfurizing agent comprises the following raw materials in parts by weight: 15-20 parts manganese oxide, 8-12 parts nano zinc oxide, 4-7 parts lanthanum oxide, 8-14 parts bentonite agent modified with carbon nanotubes, and 5-9 parts regulator and stabilizer. This invention's desulfurizing agent uses SBA-15 mesoporous material, manganese oxide, nano zinc oxide, and lanthanum oxide as the main materials, combined with bentonite agent modified with carbon nanotubes and regulator and stabilizer. Through the synergistic effect of the modified bentonite agent and regulator and stabilizer, the product exhibits significant desulfurization efficiency stability under both room temperature and low temperature conditions, as well as excellent long-term storage desulfurization efficiency stability. However, the high brittleness of the modified bentonite agent modified with carbon nanotubes can affect the mechanical properties of the desulfurizing agent.

[0004] Patent CN101485954B discloses a desulfurizing agent and its preparation method. The method for preparing the desulfurizing agent includes: mixing nano-zinc oxide, copper oxide, a binder, a pore-forming agent, and water to form a mixture; then kneading and molding the mixture to obtain a molded product; finally, drying and calcining the molded product to obtain the desulfurizing agent. The desulfurizing agent in this invention has a high sulfur capacity, but the pore-forming agent may leave uneven pores after high-temperature decomposition, affecting mass transfer.

[0005] Therefore, there is an urgent need in the market for a high-porosity nano zinc oxide desulfurizer with excellent mechanical properties. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to obtain a high-porosity nano zinc oxide desulfurizer with excellent mechanical properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a high-porosity nano zinc oxide desulfurizer, which, by weight, comprises the following raw materials: 55-70 parts of modified nano zinc oxide, 20-30 parts of binder, 10-15 parts of mesoporous silica, and 3-5 parts of rare earth metal oxide.

[0009] This application presents a nano-zinc oxide desulfurizer prepared by mixing modified nano-zinc oxide, a binder, mesoporous silica, and rare earth metal oxides. This desulfurizer exhibits excellent desulfurization performance and mechanical properties. Rare earth metal oxides possess excellent oxygen storage capacity and redox properties, promoting the dissociation and oxidation of H2S to generate elemental sulfur or sulfates, thus increasing sulfur capacity. Furthermore, in the rare earth metal oxide-zinc oxide composite system, the rare earth metal oxides can provide surface oxygen vacancies, directly activating H2S molecules and lowering the reaction energy barrier. Rare earth oxides also act as structural aids, stabilizing the nanostructure of zinc oxide at high temperatures and preventing deactivation due to sintering during regeneration.

[0010] Mesoporous silica provides a uniformly dispersed carrier for nano-zinc oxide, preventing the aggregation of active particles and exposing more active sites. The silanol groups on its surface bind to nano-zinc oxide via Si-O-Zn bonds, enhancing interfacial electron transfer and promoting the dissociation and adsorption of H2S. Furthermore, the weakly acidic sites of mesoporous silica can polarize H2S molecules, lowering the energy barrier for their reaction with nano-zinc oxide, accelerating the conversion, and further improving the desulfurization rate of the desulfurizing agent.

[0011] In some embodiments, the method for preparing the modified nano zinc oxide includes the following steps:

[0012] A1. Add silicon carbide whiskers and KH-550 silane coupling agent to an ethanol aqueous solution, sonicate at 30-40℃ for 1-2 hours, and dry to obtain modified silicon carbide whiskers.

[0013] A2. Add nonionic surfactant and n-hexanol to the reaction vessel and mix at 20-30℃ for 10-15 min. Add 14-16 wt% zinc nitrate aqueous solution and step A1 to obtain modified silicon carbide whiskers. Stir at 30-40℃ for 10-30 min. Add cyclohexane and stir for 12-16 h. Then add ammonia-saturated cyclohexane solution dropwise and stir for 20-40 min to obtain a microemulsion.

[0014] A3. Add acrylamide and initiator to n-hexanol and stir at 30-40℃ for 20-40 min to obtain a solution. Add the solution to the microemulsion obtained in step A2 and stir for 1-3 h. Irradiate with a high-pressure mercury lamp for 8-12 min, let stand, centrifuge, wash, and obtain a precipitate. Dry the precipitate to obtain a powder. Calcine the powder at 180-220℃ for 1-3 h, and then at 450-550℃ for 0.5-1 h to obtain modified nano zinc oxide.

[0015] This application utilizes silicon carbide whiskers modified with KH-550 silane coupling agent to modify nano-zinc oxide. Silicon carbide can interweave within the modified nano-zinc oxide to form a three-dimensional network, further enhancing the porosity and mechanical properties of the desulfurizer and constructing a macroporous-mesoporous gradient structure, which is beneficial for further improving the sulfur capacity of the desulfurizer. The high melting point and rigid structure of silicon carbide whiskers can act as a skeletal support during high-temperature calcination or desulfurization, effectively blocking contact between nano-zinc oxide particles and preventing sintering and agglomeration. Furthermore, rare earth metal ions can accept electrons from the surface of silicon carbide whiskers, promoting oxygen vacancy generation and enhancing the adsorption activity of nano-zinc oxide for H2S. Simultaneously, the thermal conductivity of silicon carbide whiskers accelerates sulfide oxidative desorption, preventing deactivation of active sites in the modified nano-zinc oxide due to localized overheating. The rare earth metal oxides catalyze the release of SO2; the synergistic effect of both further improves the desulfurization rate of the desulfurizer.

[0016] This application further induces the polymerization of acrylamide during the formation of modified nano-zinc oxide, allowing the long polyacrylamide chains to adsorb nano-zinc oxide particles through hydrogen bonding and electrostatic interactions, forming a composite gel network. During the calcination stage, the decomposition of polyacrylamide gives the prepared modified nano-zinc oxide a hierarchical porous structure, further improving the sulfur capacity and desulfurization rate of the desulfurizing agent.

[0017] In some embodiments, the mass ratio of the silicon carbide whiskers to the KH-550 silane coupling agent is 1:(0.1-0.2).

[0018] This application enables the nano zinc oxide desulfurizer to have superior desulfurization rate and mechanical strength by limiting the ratio of silicon carbide whiskers and KH-550 silane coupling agent. This may be because the ratio allows the modified silicon carbide whiskers to have better dispersibility while avoiding the generation of excessive silane pyrolysis products that block the pores of the modified nano zinc oxide, thus giving the nano zinc oxide desulfurizer better desulfurization performance.

[0019] In some embodiments, the nonionic surfactant is one or more of Span, Tween, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0020] Preferably, the nonionic surfactant is Span-80.

[0021] In some embodiments, the mass ratio of the 14-16 wt% zinc nitrate aqueous solution to the modified silicon carbide whiskers in step A2 is 1:(0.01-0.03).

[0022] This application enables the high-porosity nano-zinc oxide desulfurizer to have better desulfurization rate and mechanical properties by limiting the ratio of 14-16 wt% zinc nitrate aqueous solution and modified silicon carbide whiskers. This may be because this ratio can improve the mechanical properties of the desulfurizer and make it less likely for silicon carbide whiskers to cover the active sites of nano-zinc oxide, thus giving the modified nano-zinc oxide high sulfur capacity.

[0023] In some embodiments, the mass ratio of acrylamide to microemulsion in step A3 is (0.05-0.08):1.

[0024] This application allows for a higher porosity nano-zinc oxide desulfurizer to achieve better desulfurization rate and mechanical properties by limiting the ratio of acrylamide and microemulsion. This may be because the ratio allows the modified nano-zinc oxide to construct a hierarchical porous structure while preventing residual amorphous carbon from clogging the mesopores and micropores of the modified nano-zinc oxide.

[0025] In some embodiments, the binder is an aqueous solution of 3-5 wt% sodium carboxymethyl cellulose or 8-10 wt% polyvinyl alcohol.

[0026] In some embodiments, the mesoporous silica has a pore size of 6-10 nm.

[0027] This application enhances the contact probability between modified nano zinc oxide and H2S by limiting the pore size of mesoporous silica, thereby promoting the rapid diffusion of H2S molecules.

[0028] In some embodiments, the rare earth metal oxide is one or more of yttrium oxide, cerium oxide, and lanthanum oxide.

[0029] Preferably, the rare earth metal oxide is cerium oxide.

[0030] Another aspect of the present invention provides a method for preparing a high-porosity nano-zinc oxide desulfurizing agent, comprising the following steps:

[0031] S1. Mix the modified nano zinc oxide, binder, mesoporous silica and rare earth metal oxide evenly to obtain a mixture;

[0032] S2. Add the mixture obtained in step S1 into an extruder and extrude it to obtain the molding material;

[0033] S3. Let the molding material obtained in step S2 stand at 20-25℃ for 12-24 hours to obtain the health-preserving material;

[0034] S4. The curing material obtained in step S3 is first calcined at 200-300℃ for 1-3 hours, and then calcined at 450-550℃ for 2-4 hours to obtain a high-porosity nano zinc oxide desulfurizer.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The nano zinc oxide desulfurizer prepared by mixing modified nano zinc oxide, binder, mesoporous silica and rare earth metal oxide has excellent desulfurization effect and mechanical properties.

[0037] (2) This invention uses silicon carbide whiskers modified with KH-550 silane coupling agent to modify nano-zinc oxide. Silicon carbide can interweave within the modified nano-zinc oxide to form a three-dimensional network, further improving the porosity and mechanical properties of the desulfurizer and constructing a macroporous-mesoporous gradient structure, which is beneficial for further improving the sulfur capacity of the desulfurizer. Silicon carbide also acts as a skeletal support, effectively blocking contact between nano-zinc oxide particles and preventing sintering and agglomeration. Furthermore, rare earth metal ions can accept electrons from the surface of the silicon carbide whiskers, promoting the generation of oxygen vacancies and enhancing the adsorption activity of nano-zinc oxide for H2S. Simultaneously, the synergistic effect of silicon carbide whiskers and rare earth metal oxides further improves the desulfurization rate of the desulfurizer.

[0038] (3) This invention further induces the polymerization of acrylamide during the formation of modified nano-zinc oxide, allowing the long polyacrylamide chains to adsorb nano-zinc oxide particles through hydrogen bonding and electrostatic interactions, forming a composite gel network. During the calcination stage, the decomposition of polyacrylamide gives the prepared modified nano-zinc oxide a multi-level porous structure, further improving the sulfur capacity and desulfurization rate of the desulfurizing agent. Detailed Implementation

[0039] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0040] In the following examples and comparative examples, except for the modified nano zinc oxide, all other compounds and related reagents used were commercially available. Specifically, the silicon carbide whiskers, with a diameter of 0.1-2.5 μm and a length of 10-50 μm, were purchased from Guangzhou Hongwu Materials Technology Co., Ltd.; the mesoporous silica, with a grain size of 1-10 μm and a pore size of 6-10 nm, was purchased from Auscatalytic Materials (Dalian) Co., Ltd.; the cerium oxide, with an average particle size of 30 nm, was purchased from Hubei Langbowan Biomedical Co., Ltd.; and the nano-active zinc oxide was purchased from Shijiazhuang Baisheng Chemical Co., Ltd.

[0041] Preparation Example 1

[0042] The preparation method of modified nano zinc oxide-1 includes the following steps:

[0043] A1. Add 10g of silicon carbide whiskers and 1.5g of KH-550 silane coupling agent to 70g of 50wt% ethanol aqueous solution, sonicate at 35℃ for 1.5h, and dry to obtain modified silicon carbide whiskers.

[0044] A2. Add 10g Span-80 and 9ml n-hexanol to the reaction vessel and mix at 25°C for 12min. Add 100g of 15wt% zinc nitrate aqueous solution and 2g of modified silicon carbide whiskers obtained in step A1. Stir at 35°C for 20min. Add 30ml of cyclohexane and stir for 14h. Then add 20ml of ammonia-saturated cyclohexane solution dropwise and stir for 30min to obtain a microemulsion.

[0045] A3. Add 6.5g of acrylamide and 0.1g of azobisisobutyronitrile to 30ml of n-hexanol and stir at 35℃ for 30min to obtain a solution. Add the solution to 100g of the microemulsion obtained in step A2, stir for 2h, and irradiate with a high-pressure mercury lamp for 10min at a dominant wavelength of 360nm and a light intensity of 36mW / cm². 2 After standing, centrifugation, and washing, a precipitate was obtained. After drying, a powder was obtained. The powder was calcined at 200℃ for 2 hours and then at 500℃ for 1 hour to obtain modified nano zinc oxide-1.

[0046] Preparation Example 2

[0047] The preparation method of modified nano zinc oxide-2 is the same as that of preparation example 1, except that the amount of KH-550 silane coupling agent added is 2.5g.

[0048] Preparation Example 3

[0049] The preparation method of modified nano zinc oxide-3 is the same as that of preparation example 1, except that the amount of modified silicon carbide whiskers added in step A2 is 4g.

[0050] Preparation Example 4

[0051] The preparation method of modified nano zinc oxide-4 is the same as that of preparation example 1, except that the amount of acrylamide added in step A3 is 10g.

[0052] Preparation Example 5

[0053] The preparation method of modified nano zinc oxide-5 includes the following steps:

[0054] A1. Add 10g of silicon carbide whiskers and 1.5g of KH-550 silane coupling agent to 70g of 50wt% ethanol aqueous solution, sonicate at 35℃ for 1.5h, and dry to obtain modified silicon carbide whiskers.

[0055] A2. Add 10g Span-80 and 9ml n-hexanol to the reaction vessel and mix at 25°C for 12min. Add 100g of 15wt% zinc nitrate aqueous solution and 2g of modified silicon carbide whiskers obtained in step A1. Stir at 35°C for 20min. Add 30ml of cyclohexane and stir for 14h. Then add 20ml of ammonia-saturated cyclohexane solution dropwise and stir for 30min to obtain a microemulsion.

[0056] A3. Centrifuge the microemulsion obtained in step A2, dry it to obtain powder, calcine the powder at 200℃ for 2 hours, and then calcine it at 500℃ for 1 hour to obtain modified nano zinc oxide-5.

[0057] Preparation Example 6

[0058] The preparation method of modified nano zinc oxide-6 includes the following steps:

[0059] A1. Add 10g Span-80 and 9ml n-hexanol to a reaction vessel and mix at 25°C for 12min. Add 100g of 15wt% zinc nitrate aqueous solution and stir at 35°C for 20min. Add 30ml of cyclohexane and stir for 14h. Then add 20ml of ammonia-saturated cyclohexane solution dropwise and stir for 30min to obtain a microemulsion.

[0060] A2. Add 6.5g of acrylamide and 0.1g of azobisisobutyronitrile to 30ml of n-hexanol and stir at 35℃ for 30min to obtain a solution. Add the solution to 100g of the microemulsion obtained in step A1, stir for 2h, and irradiate with a high-pressure mercury lamp for 10min at a dominant wavelength of 360nm and a light intensity of 36mW / cm². 2 After standing, centrifugation, and washing, a precipitate was obtained. After drying, a powder was obtained. The powder was calcined at 200℃ for 2 hours and then at 500℃ for 1 hour to obtain modified nano zinc oxide-6.

[0061] Example 1

[0062] A high-porosity nano zinc oxide desulfurizer, by weight, comprises the following raw materials: 165 parts modified nano zinc oxide, 25 parts 4 wt% sodium carboxymethyl cellulose aqueous solution, 12 parts mesoporous silica, and 4 parts cerium oxide.

[0063] The preparation method of the high-porosity nano zinc oxide desulfurizer in this embodiment includes the following steps:

[0064] S1. Mix modified nano zinc oxide-1, 4 wt% sodium carboxymethyl cellulose aqueous solution, mesoporous silica and cerium oxide evenly to obtain a mixture;

[0065] S2. Add the mixture obtained in step S1 into an extruder and extrude it to obtain the molding material;

[0066] S3. Let the molding material obtained in step S2 stand at room temperature for 18 hours to obtain the health care material;

[0067] S4. The curing material obtained in step S3 is first calcined at 250℃ for 2 hours, and then calcined at 500℃ for 3 hours to obtain a high-porosity nano zinc oxide desulfurizer.

[0068] Example 2

[0069] A high-porosity nano zinc oxide desulfurizer, by weight, comprises the following raw materials: 155 parts modified nano zinc oxide, 20 parts 4 wt% sodium carboxymethyl cellulose aqueous solution, 10 parts mesoporous silica, and 3 parts cerium oxide.

[0070] The preparation method of the high-porosity nano zinc oxide desulfurizer in this embodiment includes the following steps:

[0071] S1. Mix modified nano zinc oxide-1, 4 wt% sodium carboxymethyl cellulose aqueous solution, mesoporous silica and cerium oxide evenly to obtain a mixture;

[0072] S2. Add the mixture obtained in step S1 into an extruder and extrude it to obtain the molding material;

[0073] S3. Let the molding material obtained in step S2 stand at room temperature for 12 hours to obtain the health care material;

[0074] S4. The curing material obtained in step S3 is first calcined at 200℃ for 3 hours, and then calcined at 450℃ for 4 hours to obtain a high-porosity nano zinc oxide desulfurizer.

[0075] Example 3

[0076] A high-porosity nano zinc oxide desulfurizer, by weight, comprises the following raw materials: 170 parts modified nano zinc oxide, 30 parts 4 wt% sodium carboxymethyl cellulose aqueous solution, 15 parts mesoporous silica, and 5 parts cerium oxide.

[0077] The preparation method of the high-porosity nano zinc oxide desulfurizer in this embodiment includes the following steps:

[0078] S1. Mix modified nano zinc oxide-1, 4 wt% sodium carboxymethyl cellulose aqueous solution, mesoporous silica and cerium oxide evenly to obtain a mixture;

[0079] S2. Add the mixture obtained in step S1 into an extruder and extrude it to obtain the molding material;

[0080] S3. Let the molding material obtained in step S2 stand at room temperature for 24 hours to obtain the health care material;

[0081] S4. The curing material obtained in step S3 is first calcined at 300℃ for 1 hour, and then calcined at 550℃ for 2 hours to obtain a high-porosity nano zinc oxide desulfurizer.

[0082] Example 4

[0083] A high-porosity nano zinc oxide desulfurizer and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified nano zinc oxide-1 is replaced with modified nano zinc oxide-2 in equal amounts.

[0084] Example 5

[0085] A high-porosity nano zinc oxide desulfurizer and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified nano zinc oxide-1 is replaced with modified nano zinc oxide-3 in equal amounts.

[0086] Example 6

[0087] A high-porosity nano zinc oxide desulfurizer and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that modified nano zinc oxide-1 is replaced with modified nano zinc oxide-4 in equal amounts.

[0088] Example 7

[0089] A high-porosity nano zinc oxide desulfurizer and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified nano zinc oxide-1 is replaced with modified nano zinc oxide-5 in equal amounts.

[0090] Example 8

[0091] A high-porosity nano zinc oxide desulfurizer and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that modified nano zinc oxide-1 is replaced with modified nano zinc oxide-6 in equal amounts.

[0092] Comparative Example 1

[0093] A high-porosity nano zinc oxide desulfurizer and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the modified nano zinc oxide-1 is replaced with an equal amount of nano active zinc oxide.

[0094] Performance testing

[0095] The performance of the high-porosity nano-zinc oxide desulfurizers obtained in the above embodiments was tested:

[0096] The prepared nano-zinc oxide composite desulfurizer was ground into 40-60 mesh particles for hydrogen sulfide penetration testing. The conditions were as follows: sample tube inner diameter 6 mm, sample loading height 2 cm, gas flow rate 100 ml / min, experimental temperature 30℃, and experimental pressure atmospheric pressure. The inlet hydrogen sulfide concentration was 800 mg / m³. 3The hydrogen sulfide concentration at the outlet is 0.15 mg / m³. 3 The experiment was stopped at the designated time. The hydrogen sulfide content in the gas was determined by gas chromatography. The sulfur capacity was calculated by chemical analysis: sulfur capacity = (weight of hydrogen sulfide absorbed by the desulfurizing agent / initial mass of the desulfurizing agent) × 100%. The usage time for the desulfurizing agent to reach saturation was calculated based on the sulfur capacity. The specific surface area of ​​the desulfurizing agent was measured using the BET method; the crushing strength was measured using a particle strength tester purchased from Dalian Penghui Technology Development Co., Ltd., model: KQ-3. The test results are shown in Table 1.

[0097] Table 1

[0098] Group <![CDATA[Specific surface area / (m 2 / g)]]> Compressive strength (N / cm) Sulfur capacity / % Example 1 265 92 62 Example 2 268 95 65 Example 3 260 90 60 Example 4 256 90 57 Example 5 258 92 58 Example 6 253 89 54 Example 7 225 83 47 Example 8 232 85 45 Comparative Example 1 201 79 39

[0099] As shown in Table 1, the high-porosity nano-zinc oxide desulfurizers used in Examples 1-3 exhibit excellent desulfurization effects and mechanical properties. A comparison between Example 4 and Example 1 shows that changing the ratio of silicon carbide whiskers to KH-550 silane coupling agent generates excessive silane pyrolysis products that clog the pores of the modified nano-zinc oxide, leading to a decrease in the porosity and sulfur capacity of the nano-zinc oxide desulfurizer. A comparison between Example 5 and Example 1 shows that changing the ratio of 14-16 wt% zinc nitrate aqueous solution to modified silicon carbide whiskers causes the silicon carbide whiskers to cover the active sites of the nano-zinc oxide, thus reducing the sulfur capacity of the nano-zinc oxide desulfurizer. A comparison between Example 6 and Example 1 shows that changing the ratio of acrylamide... The ratio of amorphous carbon to microemulsion can cause amorphous carbon to clog the mesopores and micropores of modified nano-zinc oxide, resulting in a decrease in the porosity and sulfur capacity of the nano-zinc oxide desulfurizer. A comparison between Example 7 and Example 1 shows that without acrylamide modification of nano-zinc oxide, the nano-zinc oxide desulfurizer exhibits poor mechanical properties and reduced porosity and sulfur capacity. A comparison between Examples 7, 8, and Example 1 shows that without acrylamide modification or without silicon carbide whisker modification of nano-zinc oxide, the nano-zinc oxide desulfurizer exhibits poor mechanical properties and reduced porosity and sulfur capacity. A comparison between Comparative Example 1 and Example 1 shows that without modification of nano-zinc oxide, the nano-zinc oxide desulfurizer exhibits decreased porosity and sulfur capacity and poor mechanical properties.

[0100] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-porosity nano-zinc oxide desulfurizer, characterized in that, By weight, it contains the following raw materials: 55-70 parts modified nano zinc oxide, 20-30 parts binder, 10-15 parts mesoporous silica, and 3-5 parts rare earth metal oxide.

2. The high-porosity nano-zinc oxide desulfurizer according to claim 1, characterized in that, The preparation method of the modified nano zinc oxide includes the following steps: A1. Add silicon carbide whiskers and KH-550 silane coupling agent to an ethanol aqueous solution, sonicate at 30-40℃ for 1-2 hours, and dry to obtain modified silicon carbide whiskers. A2. Add nonionic surfactant and n-hexanol to the reaction vessel and mix at 20-30℃ for 10-15 min. Add 14-16 wt% zinc nitrate aqueous solution and step A1 to obtain modified silicon carbide whiskers. Stir at 30-40℃ for 10-30 min. Add cyclohexane and stir for 12-16 h. Then add ammonia-saturated cyclohexane solution dropwise and stir for 20-40 min to obtain a microemulsion. A3. Add acrylamide and initiator to n-hexanol and stir at 30-40℃ for 20-40 min to obtain a solution. Add the solution to the microemulsion obtained in step A2 and stir for 1-3 h. Irradiate with a high-pressure mercury lamp for 8-12 min, let stand, centrifuge, wash, and obtain a precipitate. Dry the precipitate to obtain a powder. Calcine the powder at 180-220℃ for 1-3 h, and then at 450-550℃ for 0.5-1 h to obtain modified nano zinc oxide.

3. The high-porosity nano-zinc oxide desulfurizer according to claim 2, characterized in that, The mass ratio of the silicon carbide whiskers to the KH-550 silane coupling agent is 1:(0.1-0.2).

4. The high-porosity nano-zinc oxide desulfurizer according to claim 2, characterized in that, The nonionic surfactant is one or more of Span, Tween, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

5. The high-porosity nano-zinc oxide desulfurizer according to claim 2, characterized in that, The mass ratio of the 14-16 wt% zinc nitrate aqueous solution and the modified silicon carbide whiskers in step A2 is 1:(0.01-0.03).

6. The high-porosity nano-zinc oxide desulfurizer according to claim 2, characterized in that, The mass ratio of acrylamide to microemulsion in step A3 is (0.05-0.08):

1.

7. The high-porosity nano-zinc oxide desulfurizer according to claim 1, characterized in that, The binder is an aqueous solution of 3-5 wt% sodium carboxymethyl cellulose or 8-10 wt% polyvinyl alcohol.

8. The high-porosity nano-zinc oxide desulfurizer according to claim 1, characterized in that, The mesoporous silica has a pore size of 6-10 nm.

9. The high-porosity nano-zinc oxide desulfurizer according to claim 1, characterized in that, The rare earth metal oxide is one or more of yttrium oxide, cerium oxide, and lanthanum oxide.

10. A method for preparing a high-porosity nano-zinc oxide desulfurizing agent according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Mix the modified nano zinc oxide, binder, mesoporous silica and rare earth metal oxide evenly to obtain a mixture; S2. Add the mixture obtained in step S1 into an extruder and extrude it to obtain the molding material; S3. Let the molding material obtained in step S2 stand at 20-25℃ for 12-24 hours to obtain the health-preserving material; S4. The curing material obtained in step S3 is first calcined at 200-300℃ for 1-3 hours, and then calcined at 450-550℃ for 2-4 hours to obtain a high-porosity nano zinc oxide desulfurizer.