High-temperature dechlorinating agent and preparation method thereof

Abstract

The invention relates to the technical field of dechlorinating agent processing, and particularly discloses a high-temperature dechlorinating agent and a preparation method thereof. Comprising the following components in parts by weight: 70-80 parts of a composite carrier, 10-15 parts of a pore-forming agent and 3-8 parts of an adhesive, and the composite carrier is prepared by carrying out metal salt active component loading on mixed pseudo-boehmite powder and silicon dioxide powder and then carrying out reduction treatment; the prepared composite carrier is used as a raw material of the dechlorinating agent, so that the dechlorinating agent can still have efficient dechlorinating capacity, excellent physical properties and high-temperature stability at high temperature, and the service life of the dechlorinating agent is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of dechlorinating agents, and more specifically, it relates to a high-temperature dechlorinating agent and a preparation method thereof. Background Art

[0002] In the booming pattern of the current chemical industry, chlorine poses hidden problems in many key production links, bringing severe challenges to chemical production. From the perspective of equipment corrosion, in the chemical production system, under high-temperature environments and the presence of water vapor, chlorine reacts with water to form hydrochloric acid. Its strong acidic nature will violently attack equipment and facilities such as reaction kettles, pipelines, and valves made of metal materials. The continuous corrosion causes the surface of the equipment to become pitted and the wall thickness to decrease sharply. This not only seriously weakens the mechanical strength and pressure-bearing capacity of the equipment but also greatly increases the risk of sudden leakage or catastrophic failure of the equipment. The maintenance and replacement costs are high, and the production continuity is frequently interrupted. Additionally, in chemical processes involving an ammonia atmosphere, chlorine is extremely likely to combine with ammonia to form ammonium salts such as ammonium chloride. These ammonium salts crystallize and precipitate in large quantities at positions such as pipe bends with lower temperatures and the surfaces of heat exchange equipment, quickly accumulating to cause the pipeline to become narrow or even completely blocked, seriously hindering the smooth transmission of materials and energy. At the same time, after the ammonium salts absorb moisture, they form a strong electrolyte solution, further accelerating the electrochemical corrosion of the surrounding metals, forming a vicious cycle and seriously damaging the integrity of the equipment. Catalyst poisoning is also a persistent nightmare of chlorine in chemical production. In many key catalytic reaction links, such as hydrofining in petroleum refining and polymerization reactions in chemical synthesis, trace amounts of chlorine impurities adsorbing on the active sites of the catalyst will cause a significant reduction in the catalyst activity, damage to the selectivity, disorder in the catalytic reaction process, difficulty in meeting the product quality standards, premature scrapping of expensive catalysts, and a sharp rise in production costs.

[0003] In view of the many hazards of chlorine, dechlorinating agents have emerged as the "guardians" of chemical production. However, the active ingredient dispersion of most products is poor, resulting in a limited effective area in contact with chlorine and difficult to improve the dechlorination efficiency; the thermal stability of the carrier is poor. Once encountering high-temperature working conditions, the carrier structure rapidly collapses, and the active ingredients fall off and become inactivated, unable to continuously exert the dechlorination effect; the pore structure design is rough, making it difficult for gas molecules to diffuse inside the dechlorinating agent, with too large a mass transfer resistance to quickly capture chlorine atoms and unable to meet the real-time dechlorination requirements of complex chemical processes. Therefore, the present invention provides a high-temperature dechlorinating agent and a preparation method thereof to solve the above-mentioned technical problems. Summary of the Invention

[0004] Aiming at the deficiencies existing in the prior art, the composite carrier prepared in the present invention is used as the raw material of the dechlorinating agent, enabling the dechlorinating agent to still possess high dechlorination ability, excellent physical properties, and high-temperature stability at high temperatures, and increasing the service life of the dechlorinating agent.

[0005] The present invention provides a high-temperature dechlorination agent, adopting the following technical solution:

[0006] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 70 - 80 parts of a composite carrier, 10 - 15 parts of a pore-forming agent, and 3 - 8 parts of an adhesive.

[0007] Preferably, the preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 0.5 - 1 mol / L sodium borohydride solution, continuously stir at 0 - 5 °C for 1 - 3 h, then centrifuge for solid-liquid separation. The precipitate is washed with deionized water and ethanol and then vacuum dried, and the obtained product is the composite carrier.

[0008] Preferably, the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and the 0.5 - 1 mol / L sodium borohydride solution is 85 - 95:100 - 110:6 - 10:40 - 50.

[0009] Preferably, the preparation method of the pretreated carrier substrate is as follows: add equal amounts of polyacrylic acid to 0.1 - 0.2 mol / L copper nitrate solution and 0.05 - 0.1 mol / L nickel nitrate solution respectively, continuously stir at 40 - 50 °C for 10 - 15 min, then divide the carrier substrate evenly into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continuously stir at 60 - 70 °C for 12 - 24 h, then combine the two and filter. The filter cake is washed with deionized water and dried, and the obtained product is the pretreated carrier substrate.

[0010] Preferably, the preparation method of the carrier substrate is as follows: add pseudo-boehmite powder to deionized water, perform ultrasonic treatment for 20 - 30 min, then filter and dry, and then add silica powder, stir for 30 - 50 min until evenly mixed, and the obtained product is the carrier substrate.

[0011] Preferably, the mass ratio of the pseudo-boehmite powder to the silica powder is 8 - 11:1 - 3.

[0012] Preferably, the pore-forming agent is at least one of sodium bicarbonate, activated carbon, and starch.

[0013] Preferably, the adhesive is one or a combination of several of sesbania powder, polyvinyl alcohol, sodium carboxymethyl cellulose, and bentonite.

[0014] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0015] (1) Weigh a certain amount of the composite carrier, pore-forming agent, and adhesive according to the ratio, and fully grind and mix the above materials evenly;

[0016] (2) Add deionized water with a temperature of 60 - 85°C to the mixed materials. The mass ratio of the mixed materials to deionized water is (1 - 3):(3 - 6). Granulate to obtain particles with Φ = 2 - 10 mm, and dry at 80 - 100°C for 8 - 12 h;

[0017] (3) Calcinate the dried particles at 550 - 600°C for 2 - 4 h to obtain the high-temperature dechlorination agent.

[0018] Preferably, in the step (1), the materials are sufficiently ground to pass through a 60 - 100 mesh sieve.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The high-temperature filter agent of the present invention is prepared by mixing a composite carrier, a pore-forming agent, and a binder according to the formula amounts, and through processes of extrusion molding, drying, and calcination. Each component complements each other, and the overall stability is excellent. The dechlorination agent can maintain a high dechlorination effect for a long time in a high-temperature environment, reduce the replacement frequency, save the maintenance cost. The reagents used in the preparation process are all environmentally friendly materials, which conform to the principles of green chemistry and reduce the impact on the environment.

[0021] 2. The composite carrier is the core component of the entire dechlorination agent, which is formed by mixing and grinding pseudo-boehmite powder and silica powder. The former has strong thermal stability and excellent chemical inertness, and the latter strengthens the structural support. The two cooperate to ensure the mechanical strength and durability of the finished product. When pretreating, polyacrylic acid, copper nitrate, and nickel nitrate solutions are introduced to form a uniform metal oxide coating on the surface of the carrier substrate, increasing the active sites and greatly improving the dechlorination efficiency. Through the reduction reaction of sodium borohydride under low-temperature conditions, cerium oxide is uniformly dispersed in the carrier substrate to form a composite carrier with excellent thermal stability, ensuring that the dechlorination agent can maintain a high dechlorination ability even under high-temperature conditions. The use of the binder and the pore-forming agent not only effectively bonds each component during the molding process, ensures the molding quality of the dechlorination agent, gives the product a certain flexibility and compressive strength, but also effectively increases the porosity of the dechlorination agent, promotes gas diffusion, and improves the mass transfer efficiency, thereby enhancing the speed and depth of the dechlorination reaction. The three cooperate with each other to greatly enhance the capture and conversion efficiency of chlorine atoms, ensure precise dechlorination in high-temperature complex working conditions, effectively reduce the chlorine content, and prevent problems such as chlorine erosion of downstream equipment and catalyst poisoning. Specific Embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0023] In the experimental methods of the following examples, unless otherwise specified, they are all conventional methods. The test materials used, unless otherwise specified, are all purchased from conventional biochemical reagent stores. In the following examples, quantitative tests are all set with three repeated experiments, and the data are the average value or average value ± standard deviation of the three repeated experiments.

[0024] Example 1

[0025] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 70 parts of a composite carrier, 10 parts of starch, and 3 parts of polyvinyl alcohol.

[0026] The preparation method of the composite carrier is as follows: The pretreated carrier substrate is evenly dispersed in absolute ethanol, cerium oxide is added, and it is stirred evenly at room temperature. A 0.5 mol / L sodium borohydride solution is added dropwise at a rate of 1 mL / min, the stirring rate is controlled at 300 rpm / min, and it is continuously stirred at 0 °C for 3 h and then centrifuged for solid-liquid separation. The precipitate is washed with deionized water and ethanol and then vacuum dried. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 0.5 mol / L sodium borohydride solution is 85:100:6:40.

[0027] The preparation method of the pretreated carrier substrate is as follows: According to the parts by weight, 16 parts of polyacrylic acid are evenly divided into 5 parts of 0.1 mol / L copper nitrate and 3 parts of 0.05 mol / L nickel nitrate solutions. The stirring rate is controlled at 150 rpm / min, and it is continuously stirred at 40 °C for 15 min. Then 10 parts of the carrier substrate are evenly divided into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution. It is continuously stirred at 60 °C for 24 h and then the two are combined and filtered. The filter cake is washed with deionized water and dried. What is obtained is the pretreated carrier substrate.

[0028] The preparation method of the carrier substrate is as follows: Pseudoboehmite powder is added to deionized water, ultrasonicated at 30 kHz for 30 min and then filtered and dried. Then silica powder is added and stirred at room temperature for 30 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of pseudoboehmite powder, deionized water, and silica powder is 8:18:1.

[0029] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0030] (1) Weigh a quantitative amount of the composite carrier, starch, and polyvinyl alcohol according to the ratio, grind the above materials to 60 mesh, and then mix the above-ground raw materials evenly;

[0031] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 60 °C, and the mass ratio of the mixed materials to deionized water is 1:3. Granulate to obtain particles with Φ = 2 mm, and dry at 80 °C for 12 h;

[0032] (3) Roast the dried particles at 550 °C for 4 h to obtain the high-temperature dechlorination agent.

[0033] Example 2

[0034] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 72 parts of a composite carrier, 11 parts of activated carbon, and 4 parts of bentonite.

[0035] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 0.6 mol / L sodium borohydride solution at a rate of 2 mL / min, control the stirring rate at 320 pm / min, continuously stir at 1 °C for 2.6 h, then centrifuge for solid-liquid separation. Wash the precipitate with deionized water and ethanol and then perform vacuum drying. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 0.6 mol / L sodium borohydride solution is 86:102:7:42.

[0036] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly divide 18 parts of polyacrylic acid into 6 parts of 0.12 mol / L copper nitrate and 4 parts of 0.06 mol / L nickel nitrate solutions, control the stirring rate at 160 rpm / min, continuously stir at 42 °C for 14 min, then evenly divide 11 parts of the carrier substrate into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continuously stir at 61 °C for 23 h, then combine and filter the two. Wash the filter cake with deionized water and dry it. What is obtained is the pretreated carrier substrate.

[0037] The preparation method of the carrier substrate is as follows: add pseudoboehmite powder to deionized water, perform ultrasonic treatment at 34 kHz for 29 min, then filter and dry, add silica powder, and grind for 32 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of pseudoboehmite powder, deionized water, and silica powder is 9:19:2.

[0038] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0039] (1) Weigh a certain amount of the composite carrier, activated carbon, and bentonite according to the ratio, grind the above materials to 70 mesh, and then mix the above-ground raw materials evenly;

[0040] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 65 °C, the mass ratio of the mixed materials to deionized water is 2:5, granulate to obtain particles with Φ = 4 mm, and dry at 85 °C for 11 h;

[0041] (3) Calcinate the dried particles at 560 °C for 3.6 h to obtain the high-temperature dechlorination agent.

[0042] Example 3

[0043] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 80 parts of a composite carrier, 15 parts of sodium bicarbonate, and 8 parts of sodium carboxymethylcellulose.

[0044] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 1 mol / L sodium borohydride solution at a rate of 3 mL / min, control the stirring rate at 400 rpm / min, continuously stir at 5 °C for 1 h and then centrifuge for solid-liquid separation. The precipitate is washed with deionized water and ethanol and then vacuum dried. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 1 mol / L sodium borohydride solution is 95:110:10:50.

[0045] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly divide 24 parts of polyacrylic acid into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solutions, control the stirring rate at 200 rpm / min, continuously stir at 50 °C for 10 min, and then evenly divide 15 parts of the carrier substrate into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution. Continuously stir at 70 °C for 12 h and then combine and filter the two. The filter cake is washed with deionized water and dried. What is obtained is the pretreated carrier substrate.

[0046] The preparation method of the carrier substrate is as follows: add pseudoboehmite powder to deionized water, ultrasonically treat for 20 min at 50 kHz and then filter and dry. Then add silica powder and grind for 50 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of pseudoboehmite powder, deionized water, and silica powder is 11:25:3.

[0047] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0048] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sodium carboxymethylcellulose according to the ratio, fully grind the above materials to 100 mesh, and then evenly mix the above sufficiently ground raw materials;

[0049] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 85 °C, and the mass ratio of the mixed materials to deionized water is 3:6. Granulate to obtain particles with Φ = 10 mm, and dry at 100 °C for 8 hours;

[0050] (3) Bake the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0051] Example 4

[0052] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0053] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 0.8 mol / L sodium borohydride solution at a rate of 3 mL / min, control the stirring rate at 400 rpm / min, continuously stir at 0 °C for 1.2 h, then centrifuge for solid-liquid separation. Wash the precipitate with deionized water and ethanol, and then carry out vacuum drying. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 0.8 mol / L sodium borohydride solution is 92:107:9:50.

[0054] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly divide 22 parts of polyacrylic acid into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solutions, control the stirring rate at 200 rpm / min, continuously stir at 50 °C for 10 min, then evenly divide 14 parts of the carrier substrate into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continuously stir at 70 °C for 12 h, then combine and filter the two, wash the filter cake with deionized water and dry it. What is obtained is the pretreated carrier substrate.

[0055] The preparation method of the carrier substrate is as follows: add pseudo-boehmite powder to deionized water, ultrasonically treat for 20 min at 50 kHz, then filter and dry, add silica powder, and grind for 35 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of pseudo-boehmite powder, deionized water, and silica powder is 10:25:3.

[0056] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0057] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 meshes, and then evenly mix the above-ground raw materials;

[0058] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C, and the mass ratio of the mixed materials to deionized water is 2:5. Granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0059] (3) Roast the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0060] Comparative Example 1

[0061] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0062] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add alumina, stir evenly at room temperature, dropwise add a 0.8 mol / L sodium borohydride solution at a rate of 3 mL / min, control the stirring rate at 400 rpm / min, continuously stir at 0 °C for 1.2 h, then centrifuge for solid-liquid separation. Wash the precipitate with deionized water and ethanol and then conduct vacuum drying. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, alumina, and the 0.8 mol / L sodium borohydride solution is 92:107:9:50.

[0063] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly divide 22 parts of polyacrylic acid into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solutions, control the stirring rate at 200 rpm / min, continuously stir at 50 °C for 10 min, then evenly divide 14 parts of the carrier substrate into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continuously stir at 70 °C for 12 h, then combine and filter the two, wash the filter cake with deionized water and dry it. What is obtained is the pretreated carrier substrate.

[0064] The preparation method of the carrier substrate is as follows: add pseudo-boehmite powder to deionized water, ultrasonically treat it at 50 kHz for 20 min and then filter and dry it. Then add silica powder and grind for 35 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of the pseudo-boehmite powder, deionized water, and silica powder is 10:25:3.

[0065] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0066] (1) Weigh a certain amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 mesh, and then evenly mix the above sufficiently ground raw materials;

[0067] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C, the mass ratio of the mixed materials to deionized water is 2:5, granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0068] (3) Calcinate the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0069] Comparative Example 2

[0070] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0071] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, continue to stir at 0 °C for 1.2 h, then centrifuge for solid-liquid separation, wash the precipitate with deionized water and ethanol, and then carry out vacuum drying. What is obtained is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, and cerium oxide is 92:107:9.

[0072] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, divide 22 parts of polyacrylic acid evenly into 10 parts of 0.2 mol / L copper nitrate solution and 6 parts of 0.1 mol / L nickel nitrate solution, control the stirring rate at 200 rpm / min, continue to stir at 50 °C for 10 min, then divide 14 parts of the carrier substrate evenly into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continue to stir at 70 °C for 12 h, then combine and filter the two, wash the filter cake with deionized water and dry it. What is obtained is the pretreated carrier substrate.

[0073] The preparation method of the carrier substrate is as follows: add pseudo-boehmite powder to deionized water, perform ultrasonic treatment at 50 kHz for 20 min, then filter and dry, add silica powder, and grind for 35 min until evenly mixed. What is obtained is the carrier substrate, and the mass ratio of pseudo-boehmite powder, deionized water, and silica powder is 10:25:3.

[0074] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0075] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 meshes, and then mix the above sufficiently ground raw materials evenly;

[0076] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C, the mass ratio of the mixed materials to deionized water is 2:5, granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0077] (3) Bake the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0078] Comparative Example 3

[0079] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0080] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 0.8 mol / L sodium borohydride solution at a rate of 3 mL / min, control the stirring rate at 400 rpm / min, continuously stir at 0 °C for 1.2 h, then centrifuge for solid-liquid separation, wash the precipitate with deionized water and ethanol, and then perform vacuum drying. The obtained product is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and the 0.8 mol / L sodium borohydride solution is 92:107:9:50.

[0081] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly divide 22 parts of N,N-dimethylformamide into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solutions, control the stirring rate at 200 rpm / min, continuously stir at 50 °C for 10 min, then evenly divide 14 parts of the carrier substrate into the N,N-dimethylformamide / copper nitrate solution and the N,N-dimethylformamide / nickel nitrate solution, continuously stir at 70 °C for 12 h, then combine and filter the two, wash the filter cake with deionized water and dry it. The obtained product is the pretreated carrier substrate.

[0082] The preparation method of the carrier substrate is as follows: add pseudoboehmite powder to deionized water, perform ultrasonic treatment at 50 kHz for 20 min, then filter and dry it, add silica powder, and grind for 35 min until evenly mixed. The obtained product is the carrier substrate, and the mass ratio of the pseudoboehmite powder, deionized water, and silica powder is 10:25:3.

[0083] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0084] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 mesh, and then evenly mix the above-ground raw materials;

[0085] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C, the mass ratio of the mixed materials to deionized water is 2:5, granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0086] (3) Bake the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0087] Comparative Example 4

[0088] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0089] The preparation method of the composite carrier is as follows: uniformly disperse the pretreated carrier substrate in absolute ethanol, add cerium oxide, stir evenly at room temperature, dropwise add a 0.8 mol / L sodium borohydride solution at a rate of 3 mL / min, control the stirring rate at 400 rpm / min, continuously stir at 0 °C for 1.2 h, then centrifuge for solid-liquid separation, wash the precipitate with deionized water and ethanol, and then perform vacuum drying. The obtained product is the composite carrier, and the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 0.8 mol / L sodium borohydride solution is 92:107:9:50.

[0090] The preparation method of the pretreated carrier substrate is as follows: according to the parts by weight, evenly distribute 22 parts of polyacrylic acid into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solutions, control the stirring rate at 200 rpm / min, continuously stir at 50 °C for 10 min, then evenly divide 14 parts of the carrier substrate into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution, continuously stir at 70 °C for 12 h, then combine and filter the two, wash the filter cake with deionized water and dry it. The obtained product is the pretreated carrier substrate.

[0091] The preparation method of the carrier substrate is as follows: add pseudoboehmite powder to deionized water, perform ultrasonic treatment at 50 kHz for 20 min, then filter and dry, grind for 35 min. The obtained product is the carrier substrate, and the mass ratio of pseudoboehmite powder, deionized water, and silica powder is 10:25.

[0092] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0093] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 mesh, and then mix the above sufficiently ground raw materials evenly;

[0094] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C, the mass ratio of the mixed materials to deionized water is 2:5, granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0095] (3) Calcinate the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0096] Comparative Example 5

[0097] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a pretreated carrier substrate, 14 parts of sodium bicarbonate, and 6 parts of sesbania powder.

[0098] The preparation method of the pretreated carrier substrate is as follows: According to the parts by weight, 22 parts of polyacrylic acid are evenly divided into 10 parts of 0.2 mol / L copper nitrate solution and 6 parts of 0.1 mol / L nickel nitrate solution. The stirring rate is controlled at 200 rpm / min. After continuously stirring at 50 °C for 10 min, 14 parts of the carrier substrate are evenly divided into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution. After continuously stirring at 70 °C for 12 h, the two are combined and filtered. The filter cake is washed with deionized water and dried, and the obtained product is the pretreated carrier substrate.

[0099] The preparation method of the carrier substrate is as follows: Pseudoboehmite powder is added to deionized water, ultrasonicated at 50 kHz for 20 min and then filtered and dried. Then silica powder is added, and the mixture is ground for 35 min until evenly mixed. The obtained product is the carrier substrate, where the mass ratio of pseudoboehmite powder, deionized water, and silica powder is 10:25:3.

[0100] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0101] (1) Weigh a quantitative amount of the composite carrier, sodium bicarbonate, and sesbania powder according to the ratio, grind the above materials to 90 mesh, and then evenly mix the above-ground raw materials;

[0102] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C. The mass ratio of the mixed materials to deionized water is 2:5. Granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0103] (3) Roast the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0104] Comparative Example 6

[0105] A high-temperature dechlorination agent is composed of the following raw materials in parts by weight: 78 parts of a composite carrier and 6 parts of sesbania powder.

[0106] The preparation method of the composite carrier is as follows: The pretreated carrier substrate is evenly dispersed in absolute ethanol, cerium oxide is added, and the mixture is stirred evenly at room temperature. A 0.8 mol / L sodium borohydride solution is added dropwise at a rate of 3 mL / min. The stirring rate is controlled at 400 rpm / min. After continuously stirring at 0 °C for 1.2 h, centrifugation is carried out for solid-liquid separation. The precipitate is washed with deionized water and ethanol and then vacuum dried. The obtained product is the composite carrier, where the mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and 0.8 mol / L sodium borohydride solution is 92:107:9:50.

[0107] The preparation method of the pretreated carrier substrate is as follows: By weight, 22 parts of polyacrylic acid are evenly divided into 10 parts of 0.2 mol / L copper nitrate and 6 parts of 0.1 mol / L nickel nitrate solution. The stirring rate is controlled at 200 rpm / min. After continuously stirring at 50 °C for 10 min, 14 parts of the carrier substrate are evenly divided into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution. After continuously stirring at 70 °C for 12 h, the two are combined and filtered. The filter cake is washed with deionized water and dried, and the obtained product is the pretreated carrier substrate.

[0108] The preparation method of the carrier substrate is as follows: Boehmite powder is added to deionized water, ultrasonicated at 50 kHz for 20 min and then filtered and dried. Then, silica powder is added and ground for 35 min until evenly mixed. The obtained product is the carrier substrate, where the mass ratio of boehmite powder, deionized water and silica powder is 10:25:3.

[0109] A preparation method of a high-temperature dechlorination agent includes the following steps:

[0110] (1) Weigh a quantitative amount of the composite carrier and sesbania powder according to the ratio, grind the above materials to 90 mesh, and then mix the ground raw materials evenly;

[0111] (2) Put the mixed materials into a screw extrusion granulator, add deionized water at a temperature of 80 °C. The mass ratio of the mixed materials to deionized water is 2:5, and granulate to obtain particles with Φ = 6 mm, and dry at 100 °C for 8 h;

[0112] (3) Bake the dried particles at 600 °C for 2 h to obtain the high-temperature dechlorination agent.

[0113] Performance test

[0114] 1. Dechlorination performance test: Crush the dechlorination agents prepared in Examples 1-4 and Comparative Examples 1-6 into particles of 16-40 mesh. Measure 6 ml of the crushed and sieved sample, vibrate and pack it into a quartz reaction tube with Φ10 mm, place it in a customized heating furnace, and adjust the reaction temperature to 550 °C; N2 carrier HCl is introduced into the reaction tube, the inlet concentration is 4000 - 5000 ppm, and the inlet space velocity is 500 h

[0117] , ,

[0115] , ,

[0116] , -1 , ,

[0114] , and use a microcomputer coulomb detector to sample and measure the HCl concentration at the tail end outlet gas. When the outlet gas ≤ 0.5 ppm, it is judged as breakthrough. The experimental results are shown in Table 1.

[0115] 2. Strength test: Use the DL3 type intelligent particle strength detector produced by Dalian Penghui Technology Development Co., Ltd. to measure the strength of the sample. The experimental results are shown in Table 1.

[0116] Table 1:

[0117]

[0118] As can be seen from the results shown in Table 1 above: The comprehensive performance of the high-temperature dechlorination agent prepared in Examples 1-4 of the present invention is far superior to that of Comparative Examples 1-6.

[0119] The above content is only an example and explanation of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A high-temperature dechlorination agent, characterized in that, It consists of the following raw materials in parts by weight: 70 - 80 parts of composite carrier, 10 - 15 parts of pore former, and 3 - 8 parts of binder.

2. The high-temperature dechlorination agent according to claim 1, characterized in that, The preparation method of the composite carrier is as follows: The pretreated carrier substrate is uniformly dispersed in absolute ethanol, cerium oxide is added, and it is stirred evenly at room temperature. A sodium borohydride solution with a concentration of 0.5 - 1 mol / L is added dropwise. After continuously stirring at 0 - 5 °C for 1 - 3 h, centrifugation is carried out for solid - liquid separation. The precipitate is washed with deionized water and ethanol and then vacuum - dried. What is obtained is the composite carrier.

3. The high-temperature dechlorination agent according to claim 2, wherein, The mass ratio of the pretreated carrier substrate, absolute ethanol, cerium oxide, and the 0.5 - 1 mol / L sodium borohydride solution is 85 - 95:100 - 110:6 - 10:40 - 50.

4. The high-temperature dechlorination agent according to claim 2, wherein The preparation method of the pretreated carrier substrate is as follows: Equal amounts of polyacrylic acid are respectively added to a copper nitrate solution with a concentration of 0.1 - 0.2 mol / L and a nickel nitrate solution with a concentration of 0.05 - 0.1 mol / L. After continuously stirring at 40 - 50 °C for 10 - 15 min, the carrier substrate is evenly divided into the polyacrylic acid / copper nitrate solution and the polyacrylic acid / nickel nitrate solution. After continuously stirring at 60 - 70 °C for 12 - 24 h, the two are combined and filtered. The filter cake is washed with deionized water and dried. What is obtained is the pretreated carrier substrate.

5. The high-temperature dechlorination agent according to claim 4, characterized in that, The preparation method of the carrier substrate is as follows: Boehmite powder is added to deionized water, ultrasonic - treated for 20 - 30 min and then filtered and dried. Then, silica powder is added and stirred for 30 - 50 min until evenly mixed. What is obtained is the carrier substrate.

6. The high-temperature dechlorination agent according to claim 5, characterized in that, The mass ratio of the boehmite powder and the silica powder is 8 - 11:1 - 3.

7. The high-temperature dechlorination agent according to claim 1, characterized in that, The pore former is at least one of sodium bicarbonate, activated carbon, and starch.

8. The high-temperature dechlorination agent according to claim 1, wherein, The binder is one or a combination of several of sesbania powder, polyvinyl alcohol, sodium carboxymethyl cellulose, and bentonite.

9. A method for preparing the high-temperature dechlorination agent according to any one of claims 1-8, characterized in that, It includes the following steps: (1) Weigh a quantitative amount of composite carrier, pore former, and binder according to the ratio, and fully grind and mix the above materials evenly. (2) Add deionized water with a temperature of 60 - 85 °C to the mixed materials. The mass ratio of the mixed materials to deionized water is (1 - 3):(3 - 6). Granulate to obtain particles with Φ = 2 - 10 mm, and dry at 80 - 100 °C for 8 - 12 h. (3) The dried particles are calcined at 550 - 600 °C for 2 - 4 h to obtain the high - temperature dechlorination agent.

10. The preparation method according to claim 9, characterized in that, In step (1), the materials are fully ground until they pass through a 60 - 100 - mesh sieve.

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