A method for preparing a broad spectrum impregnated carbon for acid and base gas barrier protection

Abstract

The application discloses a preparation method of a broad-spectrum impregnated carbon for acid and alkali gas balance protection, which takes coconut shell activated carbon as a base material, is modified by an acid solution, is doped with nitrogen elements, and is loaded with 5-10% of Zr, 5-15% of Cu, 0.5-5% of Zn, 0.5-5% of Mo, 0.05-0.15 of Ag, 0.5-3.5% of K and 0.5-2.5% of Na. The Zr is derived from zirconium chloride or zirconium oxychloride, the Cu is derived from basic copper carbonate and copper chloride, the Zn is derived from basic zinc carbonate, the Mo is derived from ammonium molybdate, the Ag is derived from silver nitrate, the K is derived from potassium chloride, potassium hydroxide or potassium carbonate, and the Na is derived from sodium hydroxide, sodium carbonate or sodium bicarbonate. By increasing the acid / alkali functional groups on the surface of the activated carbon and loading the active components such as Zr, Cu, Zn, Mo, Ag, K and Na, the prepared impregnated carbon can achieve good protection effect on acid, alkali and organic gases.

Description

Technical Field

[0001] This invention relates to the field of gas protection material preparation, specifically to a method for preparing broad-spectrum impregnated carbon for acid and alkaline gas balance protection. Background Technology

[0002] Different pollutants require different adsorbents for purification. Only when adsorbents possess differentially active sites can they simultaneously adsorb different gases; such adsorbents are also known as broad-spectrum adsorbents. Due to its high specific surface area and abundant micropores, activated carbon remains the mainstream broad-spectrum adsorbent on the market.

[0003] Raw activated carbon can remove toxic gases from the air primarily through physical adsorption, exhibiting excellent adsorption capacity for large molecules, especially benzene molecules. However, it has almost no adsorption capacity for typical military toxic agents such as HCN / CNCl, as well as toxic and harmful industrial gases such as sulfur dioxide and ammonia. While traditional impregnated carbon can provide good protection against single acidic or alkaline gases or organic gases, achieving optimal results for treating different pollutants requires impregnation with multiple active components. However, these different active components on the activated carbon surface exhibit mutually exclusive effects, especially against chemically opposite acidic / alkaline gases such as sulfur dioxide and ammonia. This makes it difficult for impregnated activated carbon to achieve a good balance of protection against multiple harmful gases with different properties simultaneously. Summary of the Invention

[0004] The purpose of this invention is to improve upon the shortcomings of existing impregnated activated carbon in gas protection by providing a method for preparing broad-spectrum impregnated carbon for balanced protection against acidic and alkaline gases. The prepared broad-spectrum impregnated activated carbon has high capacity and broad-spectrum protection performance, and has good protection capabilities against toxic and harmful gases with large differences in properties, such as ammonia, sulfur dioxide, benzene, and cyanogen chloride. It can achieve a good balanced protection effect against multiple gases with large differences in chemical properties, and provides a significant exploration for the large-scale research and development and production of next-generation broad-spectrum protective materials.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] Step 1: Acid treatment modification

[0007] (1) Immerse activated carbon in an acidic aqueous solution, stir at 30~40℃ for 3~5h, wash with water, filter and dry to obtain acid-treated activated carbon;

[0008] Step 2: Nitrogen doping modification

[0009] (1) The activated carbon treated with acid in step one is immersed in a nitrogen source solution, and after standing and soaking at 30~40℃ for 3~5h, it is washed with water, filtered, dried and calcined to obtain nitrogen-doped modified activated carbon.

[0010] Step 3: One-time impregnation with active metal components

[0011] Nitrogen-doped modified activated carbon was impregnated in a zirconium source aqueous solution and soaked under stirring (in some embodiments, soaking was carried out in a water bath environment of 30~60℃ and mechanical stirring (100-500r / min) for 3~5h), filtered, dried and then added to a sodium hydroxide solution for further stirring and soaking (in some embodiments, soaking was carried out in a water bath environment of 30~60℃ and mechanical stirring (100-500r / min) for 6~10h), then filtered and dried.

[0012] The dried product is then sprayed with the impregnation liquid to ensure full absorption, and then left at 40-60℃ for 2-5 hours; then dried in a vacuum environment at 90-110℃ for 1-4 hours, and then transferred to a hot air stream at 170-200℃ for further drying and activation for 1-4 hours to obtain a carbon material impregnated with a metal active component once.

[0013] Step 4: Secondary impregnation with active metal components

[0014] The carbon material impregnated with the active metal component is sprayed with copper solution, and after being fully absorbed by stirring, it is left to stand at 40~60℃ for 2~5h; then it is placed in a hot air stream at 140~150℃ for pre-drying for 2h, and then the temperature is raised to 180~200℃ for further drying and activation for 1~2h to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0015] In step one, the acid solution is one or a combination of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and citric acid; the concentration of the acid solution is 0.1~1 mol / L.

[0016] In step two, the nitrogen source is selected from melamine, urea, and N-tris(hydroxymethyl)methacrylamide; the mass fraction is 5-10%.

[0017] In step two, the calcination conditions are as follows: under a nitrogen atmosphere, the temperature is increased to 600-800℃ at a heating rate of 0.1-0.5 L / min and calcined for 2-3 hours.

[0018] In step three, the zirconium source is selected from zirconium chloride or zirconium oxychloride; its mass concentration is 5-10%; and the concentration of the NaOH solution is 0.1-0.5 mol / L.

[0019] In step three, the impregnation solution contains 5-15% copper source, 1-5% zinc source, 1-5% molybdenum source, 0.1-0.15% silver source, 0.5-3.5% potassium source, and 0.5-2.5% sodium source;

[0020] The copper source is selected from basic copper carbonate and copper chloride; the zinc source is derived from basic zinc carbonate; the molybdenum source is derived from ammonium molybdate; the silver source is derived from silver nitrate; the potassium source is derived from potassium chloride, potassium hydroxide, potassium carbonate, or potassium bicarbonate; and the sodium source is derived from sodium hydroxide, sodium carbonate, or sodium bicarbonate.

[0021] Weigh the metal salt according to the designed doping ratio, mix ammonia and deionized water in a certain ratio to dissolve the metal salt, and stir thoroughly at 40~60℃ to obtain an impregnation solution; use a spray impregnation method to evenly spray the obtained impregnation solution onto the surface of activated carbon base carbon, stirring continuously during the spraying process. After the impregnation solution is fully absorbed by the base carbon, continue to stand at 40~60℃ for 1~6 h, dry the carbon in a vacuum environment for 1~4 h, and then put it into a hot air stream for further drying and activation for 1~4 h.

[0022] In step four, the copper solution is selected from basic copper carbonate and copper chloride.

[0023] This invention prepares a broad-spectrum impregnated carbon with good acid-base balance protection performance by acid modification, nitrogen doping, and distributed doping of activated carbon with metal active components. The prepared broad-spectrum impregnated carbon ensures that the activated carbon itself has high adsorption capacity and benzene vapor protection performance, while effectively balancing the adsorption performance of acid / base gases by increasing the content of acidic and basic groups on the surface of activated carbon. The doping of metal active components further improves the adsorption performance of acid / base gases, as well as the adsorption and catalytic ability of gases such as cyanogen chloride, thereby achieving balanced protection against a variety of gases with large differences in properties. Detailed Implementation

[0024] The implementation method of the present invention is flexible and variable, and is not limited to the specific operation method described in this example. In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0025] Example 1

[0026] A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection includes the following steps:

[0027] Step 1: Acid treatment modification

[0028] (1) Take a certain volume of phosphoric acid and mix it with deionized water to obtain a 1 mol / L phosphoric acid solution. Take 100 g of activated carbon and completely immerse it in 300 ml of phosphoric acid solution. Stir at 30 °C for 3 h.

[0029] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral. Dry it at 105°C for 3 hours for later use.

[0030] Step 2: Nitrogen doping modification

[0031] (1) Weigh 13.5g of urea and dissolve it in 300mL of deionized water under magnetic stirring. Add the acid-modified carbon obtained in step one to the urea solution and let it stand and soak for 3h at 30℃.

[0032] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral, and dry it at 105°C for 3 hours.

[0033] (3) Place the dried charcoal from step (2) into a rotary kiln and calcine it at 600~800℃ under a nitrogen atmosphere (0.1~0.5L / min) for 2~3 hours.

[0034] Step 3: One-time impregnation with active metal components

[0035] (1) Weigh 17.66g of zirconium oxychloride octahydrate and dissolve it in 100mL of deionized water under a 40℃ water bath and magnetic stirring.

[0036] (2) Add the modified carbon obtained in step two to the solution obtained in step (1) and soak it for 4 hours in a water bath at 40°C with mechanical stirring;

[0037] (3) Filter the carbon obtained in step (2) and dry it at 105°C for 2 hours for later use;

[0038] (4) Add the char obtained in step (3) to 500 mL of 0.2 mol / L NaOH solution and continue to soak for 6 h in a 40 °C water bath with mechanical stirring.

[0039] (5) Filter the carbon obtained in step (4) and dry it at 105°C for 2 hours for later use;

[0040] (6) Weigh 10g of basic copper carbonate, 2g of basic zinc carbonate, 3g of ammonium molybdate, 0.1g of silver nitrate, 0.7g of potassium hydroxide, and 0.7g of sodium carbonate, and add them to 120mL of deionized water in sequence. Stir at 55℃ for 2h until dissolved.

[0041] (7) Spray the impregnation liquid obtained in step (6) onto the surface of the carbon obtained in step (5) and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 hours.

[0042] (8) The carbon obtained in step (7) is dried in a vacuum environment at 100°C for 2 hours, and then transferred to a hot air stream at 180°C for further drying and activation for 2 hours.

[0043] Step 4: Secondary impregnation with active metal components

[0044] (1) Weigh 13g of copper chloride dihydrate and dissolve it in a water bath at 55℃ with magnetic stirring;

[0045] (2) Spray the impregnation liquid obtained in step (1) onto the surface of the carbon obtained in step three and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 to 5 hours.

[0046] (3) The carbon obtained in step (2) is pre-dried in a hot air stream at 140°C for 2 hours, and then heated to 180°C for further drying and activation for 2 hours to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0047] Example 2

[0048] A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection includes the following steps:

[0049] Step 1: Acid treatment modification

[0050] (1) Take a certain volume of phosphoric acid and mix it with deionized water to obtain a 1 mol / L phosphoric acid solution. Take 100 g of activated carbon and completely immerse it in 300 ml of phosphoric acid solution. Stir at 30 °C for 3 h.

[0051] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral. Dry it at 105°C for 3 hours for later use.

[0052] Step 2: Nitrogen doping modification

[0053] (1) Weigh 13.5g of urea and dissolve it in 300mL of deionized water under magnetic stirring. Add the acid-modified carbon obtained in step one to the urea solution and let it stand and soak for 3h at 30℃.

[0054] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral, and dry it at 105°C for 3 hours.

[0055] (3) Place the dried charcoal from step (2) into a rotary kiln and calcine it at 600~800℃ under a nitrogen atmosphere (0.1~0.5L / min) for 2~3 hours.

[0056] Step 3: One-time impregnation with active metal components

[0057] (1) Weigh 17.66g of zirconium oxychloride octahydrate and dissolve it in 100mL of deionized water under a 40℃ water bath and magnetic stirring.

[0058] (2) Add the modified carbon obtained in step two to the solution obtained in step (1) and soak it for 4 hours in a water bath at 40°C with mechanical stirring;

[0059] (3) Filter the carbon obtained in step (2) and dry it at 105°C for 2 hours for later use;

[0060] (4) Add the char obtained in step (3) to 500 mL of 0.2 mol / L NaOH solution and continue to soak for 6 h in a 40 °C water bath with mechanical stirring.

[0061] (5) Filter the carbon obtained in step (4) and dry it at 105°C for 2 hours for later use;

[0062] (6) Weigh 12g of basic copper carbonate, 2g of basic zinc carbonate, 3g of ammonium molybdate, 0.1g of silver nitrate, 0.7g of potassium hydroxide, and 0.7g of sodium carbonate, and add them to 120mL of deionized water in sequence. Stir at 55℃ for 2h until dissolved.

[0063] (7) Spray the impregnation liquid obtained in step (6) onto the surface of the carbon obtained in step (5) and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 hours.

[0064] (8) The carbon obtained in step (7) is dried in a vacuum environment at 100°C for 2 hours, and then transferred to a hot air stream at 180°C for further drying and activation for 2 hours.

[0065] Step 4: Secondary impregnation with active metal components

[0066] (1) Weigh 13g of copper chloride dihydrate and dissolve it in a water bath at 55℃ with magnetic stirring;

[0067] (2) Spray the impregnation liquid obtained in step (1) onto the surface of the carbon obtained in step three and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 to 5 hours.

[0068] (3) The carbon obtained in step (2) is pre-dried in a hot air stream at 140°C for 2 hours, and then heated to 180°C for further drying and activation for 2 hours to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0069] Example 3

[0070] A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection includes the following steps:

[0071] Step 1: Acid treatment modification

[0072] (1) Take a certain volume of phosphoric acid and mix it with deionized water to obtain a 1 mol / L phosphoric acid solution. Take 100 g of activated carbon and completely immerse it in 300 ml of phosphoric acid solution. Stir at 30 °C for 3 h.

[0073] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral. Dry it at 105°C for 3 hours for later use.

[0074] Step 2: Nitrogen doping modification

[0075] (1) Weigh 13.5g of urea and dissolve it in 300mL of deionized water under magnetic stirring. Add the acid-modified carbon obtained in step one to the urea solution and let it stand and soak for 3h at 30℃.

[0076] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral, and dry it at 105°C for 3 hours.

[0077] (3) Place the dried charcoal from step (2) into a rotary kiln and calcine it at 600~800℃ under a nitrogen atmosphere (0.1~0.5L / min) for 2~3 hours.

[0078] Step 3: One-time impregnation with active metal components

[0079] (1) Weigh 17.66g of zirconium oxychloride octahydrate and dissolve it in 100mL of deionized water under a 40℃ water bath and magnetic stirring.

[0080] (2) Add the modified carbon obtained in step two to the solution obtained in step (1) and soak it for 4 hours in a water bath at 40°C with mechanical stirring;

[0081] (3) Filter the carbon obtained in step (2) and dry it at 105°C for 2 hours for later use;

[0082] (4) Add the char obtained in step (3) to 500 mL of 0.2 mol / L NaOH solution and continue to soak for 6 h in a 40 °C water bath with mechanical stirring.

[0083] (5) Filter the carbon obtained in step (4) and dry it at 105°C for 2 hours for later use;

[0084] (6) Weigh 10g of basic copper carbonate, 3g of basic zinc carbonate, 3g of ammonium molybdate, 0.1g of silver nitrate, 0.7g of potassium hydroxide, and 0.7g of sodium carbonate, and add them to 120mL of deionized water in sequence. Stir at 55℃ for 2h until dissolved.

[0085] (7) Spray the impregnation liquid obtained in step (6) onto the surface of the carbon obtained in step (5) and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 hours.

[0086] (8) The carbon obtained in step (7) is dried in a vacuum environment at 100°C for 2 hours, and then transferred to a hot air stream at 180°C for further drying and activation for 2 hours.

[0087] Step 4: Secondary impregnation with active metal components

[0088] (1) Weigh 13g of copper chloride dihydrate and dissolve it in a water bath at 55℃ with magnetic stirring;

[0089] (2) Spray the impregnation liquid obtained in step (1) onto the surface of the carbon obtained in step three and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 to 5 hours.

[0090] (3) The carbon obtained in step (2) is pre-dried in a hot air stream at 140°C for 2 hours, and then heated to 180°C for further drying and activation for 2 hours to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0091] Example 4

[0092] A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection includes the following steps:

[0093] Step 1: Acid treatment modification

[0094] (1) Take a certain volume of phosphoric acid and mix it with deionized water to obtain a 1 mol / L phosphoric acid solution. Take 100 g of activated carbon and completely immerse it in 300 ml of phosphoric acid solution. Stir at 30 °C for 3 h.

[0095] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral. Dry it at 105°C for 3 hours for later use.

[0096] Step 2: Nitrogen doping modification

[0097] (1) Weigh 13.5g of urea and dissolve it in 300mL of deionized water under magnetic stirring. Add the acid-modified carbon obtained in step one to the urea solution and let it stand and soak for 3h at 30℃.

[0098] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral, and dry it at 105°C for 3 hours.

[0099] (3) Place the dried charcoal from step (2) into a rotary kiln and calcine it at 600~800℃ under a nitrogen atmosphere (0.1~0.5L / min) for 2~3 hours.

[0100] Step 3: One-time impregnation with active metal components

[0101] (1) Weigh 17.66g of zirconium oxychloride octahydrate and dissolve it in 100mL of deionized water under a 40℃ water bath and magnetic stirring.

[0102] (2) Add the modified carbon obtained in step two to the solution obtained in step (1) and soak it for 4 hours in a water bath at 40°C with mechanical stirring;

[0103] (3) Filter the carbon obtained in step (2) and dry it at 105°C for 2 hours for later use;

[0104] (4) Add the char obtained in step (3) to 500 mL of 0.2 mol / L NaOH solution and continue to soak for 6 h in a 40 °C water bath with mechanical stirring.

[0105] (5) Filter the carbon obtained in step (4) and dry it at 105°C for 2 hours for later use;

[0106] (6) Weigh 10g of basic copper carbonate, 2g of basic zinc carbonate, 4g of ammonium molybdate, 0.1g of silver nitrate, 0.7g of potassium hydroxide, and 0.7g of sodium carbonate, and add them to 120mL of deionized water in sequence. Stir at 55℃ for 2h until dissolved.

[0107] (7) Spray the impregnation liquid obtained in step (6) onto the surface of the carbon obtained in step (5) and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 hours.

[0108] (8) The carbon obtained in step (7) is dried in a vacuum environment at 100°C for 2 hours, and then transferred to a hot air stream at 180°C for further drying and activation for 2 hours.

[0109] Step 4: Secondary impregnation with active metal components

[0110] (1) Weigh 13g of copper chloride dihydrate and dissolve it in a water bath at 55℃ with magnetic stirring;

[0111] (2) Spray the impregnation liquid obtained in step (1) onto the surface of the carbon obtained in step three and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 to 5 hours.

[0112] (3) The carbon obtained in step (2) is pre-dried in a hot air stream at 140°C for 2 hours, and then heated to 180°C for further drying and activation for 2 hours to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0113] Example 5

[0114] A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection includes the following steps:

[0115] Step 1: Acid treatment modification

[0116] (1) Take a certain volume of phosphoric acid and mix it with deionized water to obtain a 1 mol / L phosphoric acid solution. Take 100 g of activated carbon and completely immerse it in 300 ml of phosphoric acid solution. Stir at 30 °C for 3 h.

[0117] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral. Dry it at 105°C for 3 hours for later use.

[0118] Step 2: Nitrogen doping modification

[0119] (1) Weigh 13.5g of urea and dissolve it in 300mL of deionized water under magnetic stirring. Add the acid-modified carbon obtained in step one to the urea solution and let it stand and soak for 3h at 30℃.

[0120] (2) Wash the activated carbon obtained in step (1) with deionized water and filter it several times until the filtrate is neutral, and dry it at 105°C for 3 hours.

[0121] (3) Place the dried charcoal from step (2) into a rotary kiln and calcine it at 600~800℃ under a nitrogen atmosphere (0.1~0.5L / min) for 2~3 hours.

[0122] Step 3: One-time impregnation with active metal components

[0123] (1) Weigh 17.66g of zirconium oxychloride octahydrate and dissolve it in 100mL of deionized water under a 40℃ water bath and magnetic stirring.

[0124] (2) Add the modified carbon obtained in step two to the solution obtained in step (1) and soak it for 4 hours in a water bath at 40°C with mechanical stirring;

[0125] (3) Filter the carbon obtained in step (2) and dry it at 105°C for 2 hours for later use;

[0126] (4) Add the char obtained in step (3) to 500 mL of 0.2 mol / L NaOH solution and continue to soak for 6 h in a 40 °C water bath with mechanical stirring.

[0127] (5) Filter the carbon obtained in step (4) and dry it at 105°C for 2 hours for later use;

[0128] (6) Weigh 10g of basic copper carbonate, 2g of basic zinc carbonate, 3g of ammonium molybdate, 0.1g of silver nitrate, 0.7g of potassium hydroxide, and 0.7g of sodium carbonate, and add them to 120mL of deionized water in sequence. Stir at 55℃ for 2h until dissolved.

[0129] (7) Spray the impregnation liquid obtained in step (6) onto the surface of the carbon obtained in step (5) and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 hours.

[0130] (8) The carbon obtained in step (7) is dried in a vacuum environment at 100°C for 2 hours, and then transferred to a hot air stream at 180°C for further drying and activation for 2 hours.

[0131] Step 4: Secondary impregnation with active metal components

[0132] (1) Weigh 15g of copper chloride dihydrate and dissolve it in a water bath at 55℃ with magnetic stirring;

[0133] (2) Spray the impregnation liquid obtained in step (1) onto the surface of the carbon obtained in step three and stir continuously until the impregnation liquid is fully absorbed, and then let it stand at 50°C for 2 to 5 hours.

[0134] (3) The carbon obtained in step (2) is pre-dried in a hot air stream at 140°C for 2 hours, and then heated to 180°C for further drying and activation for 2 hours to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

[0135] The protection time against sulfur dioxide, ammonia, benzene vapor, and cyanogen chloride was tested and evaluated on the samples prepared in Examples 1-5, and compared with the untreated base carbon.

[0136] Test conditions: Temperature: 20℃, Relative humidity: 50%, Specific velocity: 0.25L / min·cm2, Carbon height: 2cm, Sulfur dioxide concentration: 8g / L, Ammonia concentration: 2.1g / L, Benzene vapor concentration: 9g / L, CNCl concentration: 9g / L.

[0137] Table 1. Test data on protection time against sulfur dioxide, ammonia, benzene vapor, and cyanide chloride:

[0138] sample Sulfur dioxide penetration time / min Ammonia penetration time / min Benzene vapor breakthrough time / min Cyanide breakthrough time / min Base carbon 5 1 96 1 Example 1 45 53 82 22 Example 2 47 64 80 24 Example 3 52 56 77 23 Example 4 48 60 81 29 Example 5 42 75 82 25

[0139] As shown in Table 1, untreated activated carbon has a certain degree of protection against sulfur dioxide due to its alkalinity, but it has almost no protective effect against ammonia and cyanogen chloride. This patent prepares impregnated carbon for acid-base gas balance protection by acid modification, nitrogen doping and metal active component doping of activated carbon (Examples 1-5). The test results in Table 1 show that the modified impregnated carbon maintains a certain pore structure and a certain adsorption capacity for benzene vapor, while significantly improving the protection time against ammonia and sulfur dioxide, and can achieve a better balance protection effect against ammonia and sulfur dioxide.

Claims

1. A method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection, characterized in that: Includes the following steps: Step 1: Acid treatment modification (1) Immerse activated carbon in an acidic aqueous solution, stir at 30~40℃ for 3~5h, wash with water, filter and dry to obtain acid-treated activated carbon; The acid solution is one or a combination of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and citric acid; Step 2: Nitrogen doping modification (1) The activated carbon treated with acid in step one is immersed in a nitrogen source solution, and after standing and soaking at 30~40℃ for 3~5h, it is washed with water, filtered, dried and calcined to obtain nitrogen-doped modified activated carbon; the nitrogen source is selected from melamine, urea and N-tris(hydroxymethyl)methacrylamide. Step 3: One-time impregnation with active metal components Nitrogen-doped modified activated carbon was impregnated in a zirconium source aqueous solution, stirred and soaked, filtered and dried, then added to a sodium hydroxide solution, stirred and soaked again, filtered and dried; The dried product is then sprayed with the impregnation solution to ensure full absorption, and then left to stand at 40-60°C for 2-5 hours. It is then dried in a vacuum environment at 90-110°C for 1-4 hours, followed by further drying and activation in a hot air stream at 170-200°C for 1-4 hours, yielding a carbon material impregnated with a single metal active component. The impregnation solution contains 5-15% copper source, 1-5% zinc source, 1-5% molybdenum source, 0.1-0.15% silver source, 0.5-3.5% potassium source, and 0.5-2.5% sodium source. The copper source is selected from basic copper carbonate and copper chloride; the zinc source is derived from basic zinc carbonate; the molybdenum source is derived from ammonium molybdate; the silver source is derived from silver nitrate; the potassium source is derived from potassium chloride, potassium hydroxide, potassium carbonate, or potassium bicarbonate; and the sodium source is derived from sodium hydroxide, sodium carbonate, or sodium bicarbonate. Step 4: Secondary impregnation with active metal components The carbon material impregnated with the active metal component is sprayed with copper solution, and after being fully absorbed by stirring, it is left to stand at 40~60℃ for 2~5h; then it is placed in a hot air stream at 140~150℃ for pre-drying for 2h, and then the temperature is raised to 180~200℃ for further drying and activation for 1~2h to obtain a broad-spectrum impregnated carbon for acid-base gas balance protection.

2. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: In step one, the concentration of the acid solution is 0.1~1 mol / L.

3. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: In step two, the mass fraction of the nitrogen source solution is 5-10%.

4. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: In step two, the calcination conditions are as follows: under a nitrogen atmosphere, the temperature is increased to 600-800℃ at a heating rate of 0.1-0.5 L / min and calcined for 2-3 hours.

5. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: In step three, the zirconium source is selected from zirconium chloride or zirconium oxychloride; its mass concentration is 5-10%; and the concentration of the NaOH solution is 0.1-0.5 mol / L.

6. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: Weigh the metal salt according to the designed doping ratio, mix ammonia and deionized water in a certain ratio to dissolve the metal salt, and stir thoroughly at 40~60℃ to obtain an impregnation solution; use a spray impregnation method to evenly spray the obtained impregnation solution onto the surface of activated carbon base carbon, stirring continuously during the spraying process. After the impregnation solution is fully absorbed by the base carbon, continue to stand at 40~60℃ for 1~6 hours, dry the carbon in a vacuum environment for 1~4 hours, and then put it into a hot air stream for further drying and activation for 1~4 hours.

7. The method for preparing broad-spectrum impregnated carbon for acid-base gas balance protection according to claim 1, characterized in that: In step four, the copper solution is selected from basic copper carbonate and copper chloride.