A kind of alkali copper combined impregnated activated carbon for protecting CNCl / HCN and organic vapor and preparation method thereof

Abstract

The application provides a kind of alkali copper combined impregnated activated carbon for protecting CNCl / HCN and organic vapor and a preparation method, first, peach shell activated carbon with certain pore structure is selected, then impregnated in two steps, first, sodium alkali is impregnated into the inside of activated carbon carrier channel, then active component copper is impregnated into the inside of activated carbon carrier channel, wherein the oxide generated by thermal decomposition of Cu, Mo bimetallic impregnation solution has strong adsorption capacity for cyanide, the presence of alkali can promote the hydrolysis reaction of cyanogen chloride, and the hydrolysis product of adsorbed cyanogen chloride is hydrochloric acid. The unique pore structure of activated carbon and alkaline pretreatment are beneficial to the adsorption of DMMP organic vapor. The application first uses vacuum ultrasonic impregnation and water vapor activation to load the precursors of alkali and copper into the inside of macropore of activated carbon in turns, which not only makes the surface of impregnated carbon alkaline, but also makes the active component fully absorbed and dispersed in the channel of activated carbon.

Description

Technical Field

[0001] This invention relates to adsorption and catalytic materials for classic chemical agent protective equipment, specifically to an impregnated activated carbon for protection against CNCl / HCN and organic vapors, and its preparation method. Background Technology

[0002] Impregnated activated carbon is the core adsorption and catalytic material in gas mask filter canisters and absorbers. Currently, the main types of impregnated activated carbon used in protective equipment are ASC-T and ASZM-T. ASC-T type impregnated activated carbon is being phased out due to its content of chromium, a heavy metal harmful to humans and the environment. ASZM-T type impregnated activated carbon uses molybdenum and zinc to replace chromium, but its protective effect against CNCl does not reach the level of ASC-T type. Numerous attempts have been made to find an impregnated activated carbon that provides highly efficient protection against CNCl / HCN. For example, patent application CN106513004B, "Zirconium-loaded impregnated carbon for protection against HCN and CNCl poisons and its preparation method," loads CeO2, ZrOCl2, and other components onto crushed coconut shell carbon. The synthesis process is complex, and the impregnated carbon material has poor protective effects against HCN and CNCl poisons. Patent application CN111389362B, "A nickel-loaded impregnated carbon for protection against HCN and CNCl and its preparation method," loads Cu, Ni, Ce, and other components onto activated carbon. The numerous components used result in impregnated carbon with only moderate protective effects against CNCl poisons. Patent CN113648970A, "A Green Preparation Method of Ammonia-Free / Chromium-Impregnated Activated Carbon Adsorbent for HCN / CNCl Protection," avoids the harm to humans and the environment caused by ammonia release. However, the preparation process requires high-temperature decomposition of metal salts under inert gas protection, increasing energy consumption. Furthermore, the active components easily clog the activated carbon pores, resulting in a weaker protective effect against HCN / CNCl. Patent CN106582519A, "Catalytic Carbon for Absorbing and Protecting Against GB Class Toxic Agents and its Preparation Method," uses coal-based activated carbon as a carrier, loading it with Gr, Cu, and Ag, which shows some protective effect against organic vapors such as sarin. Currently, no research has identified a highly efficient impregnated carbon and its preparation method for protecting against CNCl / HCN and organic vapors. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides impregnated activated carbon for protection against CNCl / HCN and organic vapors, along with its preparation method, without ammonia leakage. By screening peach shell activated carbon with a specific pore structure, the active components can be appropriately distributed within the multi-level pores. The prepared impregnated activated carbon can effectively protect against CNCl / HCN poisons and adsorb large amounts of sarin vapor (replacing DMMP). The combined effect of Cu and Mo bimetals greatly enhances the protective performance against CNCl, while the alkaline pretreatment of the peach shell activated carbon strengthens its ability to adsorb DMMP vapor. Compared to single impregnation with an alkaline copper mixed solution, multiple impregnations increase both the loading of active components and their dispersibility. Activated carbon subjected to its first alkaline impregnation exhibits a stronger ability to adsorb copper-ammonia mixed solutions, allowing the active components to penetrate deeper into the pores of the carbon layer. During the catalytic degradation of the toxic gas cyanide, cyanide gas is first adsorbed onto the surface of the active component copper oxide. Its hydrolysis product, hydrochloric acid, reacts with copper oxide, poisoning the active component and thus inhibiting the continued hydrolysis of cyanide. The alkaline solution can neutralize the hydrolysis products of cyanide and protect the active component.

[0004] This invention provides a vacuum ultrasonic impregnation method, which, compared to the traditional open-air method, can effectively recover ammonia water, avoid environmental pollution, and enhance the diffusion of active components within the impregnated carbon, thereby improving its protective performance. To prevent ammonia leakage from the impregnated carbon in high-humidity and high-temperature environments, this invention employs steam induction during the activation process to remove ammonium ions. Overall, the formulation provided by this invention uses inexpensive and controllable raw materials, and the preparation process is simple, preventing ammonia leakage.

[0005] The technical solution of this invention is as follows:

[0006] An alkali-copper co-impregnated activated carbon for protection against CNCl / HCN and organic vapors, wherein the raw material for the impregnated activated carbon comprises the following components in parts by weight:

[0007] 100 parts activated carbon, 4-12 parts Na, 1-2 parts Mo, 8-12 parts ammonium bicarbonate, 5-10 parts Cu and 3-5 parts tartaric acid.

[0008] 100 parts activated carbon, 4-12 parts Na, 1-2 parts Mo, 8-12 parts ammonium bicarbonate, 5-10 parts Cu and 3-5 parts tartaric acid.

[0009] Preferably, the activated carbon is crushed peach shell activated carbon with a particle size of 12-24 mesh and a water capacity of 82%-130%;

[0010] The Cu is derived from copper oxide, Na from sodium hydroxide, and Mo from potassium molybdate.

[0011] The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors.

[0012] (1) Preparation of primary impregnation solution: Sodium hydroxide and potassium molybdate are added to pure water to obtain primary impregnation solution;

[0013] (2) Impregnation: Spray the prepared primary impregnation solution onto the activated carbon while stirring, and then let it stand;

[0014] (3) First activation: Transfer the apparent dried impregnated activated carbon to the activation furnace for forced air activation. Start timing after the temperature rises to 140~160℃ and maintain for 1~2 hours;

[0015] (4) Preparation of secondary impregnation solution: Add ammonium bicarbonate, copper oxide powder and tartaric acid to an ammonia solution;

[0016] (5) Impregnation: The prepared secondary impregnation solution is slowly sprayed into the primary impregnated activated carbon product while stirring, and ultrasonic treatment is performed.

[0017] (6) Second activation: Transfer the impregnated activated carbon to the activation furnace, control the steam generator to generate steam, and activate; then turn off the steam generator, blow air to activate, and start timing after the temperature rises to 180~200℃, and maintain for 1~2 hours.

[0018] Preferably, in step (1), the volume of pure water is 1.2-1.3 times the volume of the finished product water for one impregnation of activated carbon.

[0019] Preferably, in step (2), the spray is stirred for 8-12 minutes, and then left to stand at 45-55°C for 3-4 hours.

[0020] Preferably, in step (4) of preparing the secondary impregnation solution, the volume of ammonia water is 1-1.2 times the volume of the finished product water for the primary impregnation of activated carbon.

[0021] Preferably, in step (5), the mixture is sprayed and stirred for 8-12 minutes, and then treated for 1-2 hours in an environment with an ultrasonic frequency of 15-25 kHz, a vacuum degree of 0.06-0.1 MPa, and a temperature of 85-95℃.

[0022] Preferably, in step (6), the steam generator produces 10~20g / min of steam and activates at 135-145℃ for 1~2h; then the steam generator is turned off, and the steam is activated by blowing air. When the temperature rises to 180~200℃, the timing is started and maintained for 1~2h.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention employs a two-step impregnation process. First, sodium alkali is impregnated into the pores of the activated carbon carrier. Then, the active component, copper, is impregnated into the pores of the activated carbon carrier. The oxides generated from the thermal decomposition of the Cu and Mo bimetallic impregnation solution, acting together, possess a strong adsorption capacity for cyanide. The sodium alkali pretreatment of the peach shell activated carbon enhances its adsorption capacity for DMMP vapor. Simultaneously, the presence of alkali promotes the hydrolysis reaction of cyanogen chloride, adsorbing the hydrolysis product hydrochloric acid. Peach shell activated carbon with a water capacity of 105% possesses an optimal pore structure, facilitating the anchoring and distribution of the active components, achieving simultaneous and efficient purification of CNCl, HCN, and DMMP organic vapors.

[0025] 2. This invention is the first to employ vacuum ultrasonic impregnation and steam activation to sequentially load sodium alkali and copper precursors into the pores of activated carbon. This not only enhances the alkalinity of the impregnated carbon surface but also ensures the active components are fully absorbed and dispersed within the activated carbon pores. Vacuum ultrasonic impregnation exhibits superior mass transfer dynamics, enabling the active components to diffuse extensively within the activated carbon pores. Steam activation promotes the complete decomposition of ammonium compounds within the impregnated carbon, resulting in extremely low ammonia content. The impregnated carbon developed using this formula and process exhibits highly efficient catalytic hydrolysis of CNCl, strong chemical adsorption of HCN, and excellent adsorption of DMMP vapor. The ammonia content, measured by the Kjeldahl method, is below 0.03%, effectively preventing ammonia leakage from protective equipment in high-temperature and high-humidity environments. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to the scope described in the embodiments.

[0027] The specific embodiments of the present invention will be described in detail below.

[0028] Example 1

[0029] A protective activated carbon impregnated with CNCl / HCN and organic vapors is used. Peach shell activated carbon with a water capacity of 105% is selected as the carrier. It is initially loaded with 8% (by weight) Na and 2% (by weight) Mo. After high-temperature activation, it is loaded with 10% (by weight) ammonium bicarbonate, 7% (by weight) Cu and 4% tartaric acid by vacuum ultrasonic impregnation and activated with water vapor at high temperature.

[0030] Implementation steps:

[0031] (1) Prepare a primary impregnation solution at 1.2 times the water volume of activated carbon. Dissolve a certain amount of sodium hydroxide and potassium molybdate in pure water. After the solution is fully dissolved and free of impurities, spray the impregnation solution onto a certain amount of activated carbon surface, stir for 10 min, and let it stand in the open at 50°C for 3 h. After the impregnated carbon is apparent dry, activate it by blowing air at 150°C for 1 h to prepare primary impregnated activated carbon.

[0032] (2) Prepare a secondary impregnation solution at 1.1 times the water capacity of the primary impregnated activated carbon. Dissolve a certain amount of ammonium bicarbonate, copper oxide powder and tartaric acid powder in ammonia water. After the solution is fully dissolved and free of impurities, spray the impregnation solution onto the surface of the primary impregnated activated carbon. Then, rotate and stir for 1 hour in an environment with an ultrasonic frequency of 20 kHz, a vacuum degree of 0.09 MPa and a temperature of 90 ℃. Control the steam flow rate to 15 g / min and activate at 140 ℃ for 1 hour. Finally, turn off the steam generator, start the blower, activate at 180 ℃ for 1 hour, and obtain sample T-1.

[0033] Example 2

[0034] Based on Example 1, the rest is the same as in Example 1, except that vacuum ultrasonic impregnation is not used in step (2) to obtain sample T-2.

[0035] Example 3

[0036] Based on Example 1, the rest is the same as in Example 1, except that in step (2), high-temperature activation with water vapor is not used to obtain sample T-3.

[0037] Example 4

[0038] Based on Example 1, everything else is the same as in Example 1, except that only step 1 is performed.

[0039] A protective activated carbon impregnated with CNCl / HCN and organic vapors is prepared by using peach shell activated carbon with a water capacity of 105% as a carrier, loading it with 8% (by weight) Na and 2% (by weight) Mo, and then activating it at high temperature.

[0040] Implementation steps:

[0041] Prepare an impregnation solution at 1.2 times the volume of water for the activated carbon. Dissolve a certain amount of sodium hydroxide and potassium molybdate in pure water until fully dissolved and free of impurities. Then spray the impregnation solution onto a measured amount of activated carbon, stir for 10 minutes, and let it stand open at 50°C for 3 hours. After the impregnated carbon is apparent dry, activate it with forced air at 150°C for 1 hour to obtain sample T-4.

[0042] Example 5

[0043] Based on Example 1, everything else is the same as in Example 1, except that only step 2 is performed.

[0044] A protective activated carbon impregnated with CNCl / HCN and organic vapors is used. Peach shell activated carbon with a water capacity of 105% is selected as the carrier. It is loaded with 10% (by weight) ammonium bicarbonate, 7% (by weight) Cu and 4% tartaric acid by vacuum ultrasonic impregnation and activated by high temperature with water vapor.

[0045] Implementation steps:

[0046] Prepare an impregnation solution with 1.1 times the water capacity of the activated carbon. Dissolve a certain amount of ammonium bicarbonate, copper oxide powder, and tartaric acid powder in ammonia water until fully dissolved and free of impurities. Then, spray the impregnation solution onto the surface of a measured amount of activated carbon. Stir the activated carbon at an ultrasonic frequency of 20 kHz, a vacuum of 0.09 MPa, and a temperature of 90°C for 1 hour. Control the steam flow rate at 15 g / min and activate at 140°C for 1 hour. Finally, turn off the steam generator, start the blower, and activate at 180°C for 1 hour to obtain sample T-5.

[0047] Example 6

[0048] Based on Example 1, everything else is the same as in Example 1, except that the order of steps 1 and 2 is reversed.

[0049] A protective activated carbon impregnated with CNCl / HCN and organic vapors is used. Peach shell activated carbon with a water capacity of 105% is selected as the carrier. For the first time, 10% (by weight) ammonium bicarbonate, 7% (by weight) Cu and 4% tartaric acid are loaded by vacuum ultrasonic impregnation. After high-temperature activation with water vapor, 8% (by weight) Na and 2% (by weight) Mo are loaded again and activated by forced air.

[0050] Implementation steps:

[0051] (1) Prepare an impregnation solution at 1.1 times the water capacity of the activated carbon. Dissolve a certain amount of ammonium bicarbonate, copper oxide powder and tartaric acid powder in ammonia water. After it is fully dissolved and free of impurities, spray the impregnation solution onto the surface of a certain amount of activated carbon. Then, rotate and stir for 1 hour in an environment with an ultrasonic frequency of 20 kHz, a vacuum degree of 0.09 MPa and a temperature of 90 ℃. Control the steam flow rate to 15 g / min and activate at 140 ℃ for 1 hour. Finally, turn off the steam generator, start the blower, and activate at 180 ℃ for 1 hour.

[0052] (2) Prepare a secondary impregnation solution at 1.1 times the volume of water for the primary impregnation of activated carbon. Dissolve a certain amount of sodium hydroxide and potassium molybdate in pure water. After the solution is fully dissolved and free of impurities, spray the impregnation solution onto the surface of the primary impregnated activated carbon. Stir for 10 minutes and let stand at 50°C in the open for 3 hours. After the impregnated carbon is apparent dry, activate it by blowing air at 150°C for 1 hour to obtain sample T-6.

[0053] Example 7

[0054] Based on Example 1, everything else is the same as in Example 1, except that steps 1 and 2 are combined.

[0055] Prepare an impregnation solution with 1.1 times the water volume of the activated carbon. Dissolve a certain amount of ammonium bicarbonate, copper oxide powder, sodium hydroxide, potassium molybdate, and tartaric acid powder in ammonia water until fully dissolved and free of impurities. Then spray the impregnation solution onto the surface of a measured amount of activated carbon. Stir the activated carbon at an ultrasonic frequency of 20 kHz, a vacuum of 0.09 MPa, and a temperature of 90°C for 1 hour. Control the steam flow rate at 15 g / min and activate at 140°C for 1 hour. Finally, turn off the steam generator, start the blower, and activate at 180°C for 1 hour to obtain sample T-7.

[0056] Example 8

[0057] Based on Example 1, and with the same other conditions as Example 1, except that peach shell activated carbon with a water capacity of 82% was used to prepare sample T-8.

[0058] Example 9

[0059] Based on Example 1, and with the same other conditions as Example 1, except that peach shell activated carbon with a water capacity of 130% was used to prepare sample T-9.

[0060] The samples prepared above were subjected to CNCl, HCN, and DMMP vapor protection performance tests. The test evaluation conditions were: test temperature (20±3)℃, relative humidity (50±2)%, and airflow velocity of 0.25 L / (min·cm). 2 The power tube thickness is 2cm, the initial concentration of CNCl is 9mg / L, the initial concentration of HCN is 8mg / L, and the initial concentration of DMMP vapor is 3mg / L.

[0061] The prepared samples were subjected to ammonia content and ammonia overflow tests under high temperature and high humidity conditions. Ammonia content was determined using the Kjeldahl method; the ammonia overflow test conditions under high temperature and high humidity conditions were: test temperature (50±5)℃, relative humidity (60±5)%, and a portable ammonia detector recording at 4.5m. 3 Short-term contact concentration at the air outlet of the cabin. The results are shown in Table 1.

[0062] A comparison between Example 1 and Example 2 shows that vacuum ultrasonic impregnation can significantly improve the protective performance against CNCl, HCN, and DMMP vapors. This is mainly due to the fact that the impregnation method can significantly enhance the absorption of the impregnating components by the activated carbon and enhance the diffusion ability of the active components within the pores of the activated carbon.

[0063] A comparison between Example 1 and Example 3 shows that high-temperature activation with water vapor does not weaken the protective performance of CNCl, and can effectively reduce the ammonia content and prevent ammonia overflow.

[0064] A comparison between Example 1 and Example 4 shows that activated carbon impregnated with alkali has very poor performance in protecting against CNCl and HCN.

[0065] A comparison between Example 1 and Example 5 shows that activated carbon impregnated only with copper and molybdenum has poor performance in protecting against CNCl, HCN, and DMMP vapors.

[0066] Table 1

[0067] serial number CNCl penetration time (min) HCN penetration time (min) DMMP vapor breakthrough time (min) Ammonia content (%) Ammonia concentration (ppm) T-1 51 56 328 0.03 0.3 T-2 41 43 275 0.03 0.3 T-3 52 56 310 0.15 2.6 T-4 12 30 325 0 0 T-5 30 31 286 0.03 0.3 T-6 38 43 310 0.03 0.2 T-7 36 40 292 0.03 0.3 T-8 31 42 330 0.03 0.2 T-9 40 45 247 0.03 0.3 ASZM 31 35 268 0.07 1.6

[0068] A comparison between Example 1 and Example 6 shows that activated carbon impregnated with alkali first and then with copper has better CNCl protection performance than activated carbon impregnated with copper first and then with alkali. The alkalized activated carbon has a stronger ability to adsorb copper-ammonia mixed solution, and the active components can be better dispersed.

[0069] A comparison between Example 1 and Example 7 shows that activated carbon impregnated with alkali and copper in one step is not as effective at protecting against CNCl as activated carbon impregnated in multiple steps. Multiple impregnation is beneficial for the absorption and dispersion of copper oxide and alkali inside the pores of activated carbon.

[0070] A comparison between Example 1 and Example 8 shows that the low water capacity of peach shell activated carbon is not conducive to the protection against CNCl and HCN.

[0071] A comparison between Example 1 and Example 9 shows that the high water capacity of peach shell activated carbon is not conducive to the protection against CNCL and DMMP vapors.

[0072] In summary, the impregnated activated carbon prepared using this invention exhibits superior protection against CNCl, HCN, and DMMP vapors compared to traditional ASZM impregnated carbon. The peach shell activated carbon with a water capacity of 105% possesses the optimal pore structure, enabling simultaneous protection against CNCl, HCN, and DMMP vapors. The initial loading of sodium alkali, followed by a secondary loading of copper as the active component after activation, not only prevents the accumulation of active components within the carbon channels but also enhances the alkalinity of the carbon, promoting its adsorption of CNCl and DMMP vapors. The vacuum ultrasonic impregnation method promotes the uniform diffusion of active components copper and molybdenum within the carbon, while simultaneously recovering some ammonia, thus protecting the environment. High-temperature activation using steam significantly reduces the ammonia content of the impregnated carbon, effectively controlling ammonia leakage in high-temperature and high-humidity environments. This impregnated carbon material has a simple preparation process, uses inexpensive raw materials, is independently controllable, allows for mass production, has extremely low ammonia content, eliminates the risk of ammonia leakage, and meets market demands.

[0073] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for preparing alkali-copper co-impregnated activated carbon for protection against CNCl / HCN and organic vapors, characterized in that, The raw materials for the impregnated activated carbon include the following components in parts by weight: The preparation method comprises 100 parts activated carbon, 4-12 parts Na, 1-2 parts Mo, 8-12 parts ammonium bicarbonate, 5-10 parts Cu, and 3-5 parts tartaric acid, wherein the Cu is derived from copper oxide, the Na from sodium hydroxide, and the Mo from potassium molybdate; the preparation method includes the following steps: (1) Preparation of primary impregnation solution: Sodium hydroxide and potassium molybdate are added to pure water to obtain primary impregnation solution; (2) Impregnation: Spray the prepared primary impregnation solution onto the activated carbon while stirring, and then let it stand; (3) First activation: Transfer the apparent dried impregnated activated carbon to the activation furnace for forced air activation. After the temperature is raised to 140~160℃, maintain it for 1~2 hours. (4) Preparation of secondary impregnation solution: Add ammonium bicarbonate, copper oxide powder and tartaric acid to an ammonia solution; (5) Impregnation: The prepared secondary impregnation solution is slowly sprayed into the primary impregnated activated carbon product while spraying and stirring. The mixture is treated for 1-2 hours in an environment with an ultrasonic frequency of 15-25kHz, a vacuum degree of 0.06-0.1MPa, and a temperature of 85-95℃. (6) Second activation: Transfer the impregnated activated carbon to the activation furnace, control the steam generator to generate steam, and activate; then turn off the steam generator, blow air to activate, and start timing after the temperature rises to 180~200℃, and maintain for 1~2 hours; The activated carbon is crushed peach shell activated carbon with a water content of 82%-130%.

2. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, The activated carbon has a particle size of 12-24 mesh.

3. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, In step (1), the volume of pure water is 1.2-1.3 times the volume of the finished product water for one impregnation of activated carbon.

4. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, In step (2), spray and stir for 8-12 minutes, then let stand at 45-55℃ for 3-4 hours.

5. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, In step (4) of the preparation of the secondary impregnation solution, the volume of ammonia water is 1.0-1.2 times the volume of the finished product water of the primary impregnated activated carbon.

6. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, In step (5), spray and stir for 8-12 minutes.

7. The method for preparing alkali-copper co-impregnated activated carbon for protecting against CNCl / HCN and organic vapors according to claim 1, characterized in that, In step (6), the steam generator produces 10-20 g / min of steam and activates at 135-145°C for 1-2 hours; then the steam generator is turned off and activated by blowing air. Once the temperature rises to 180-200°C, timing begins and is maintained for 1-2 hours.