Device and method for producing ammonium nitrate by taking air and water as raw materials

Abstract

The invention provides a device and a method for producing ammonium nitrate by taking air and water as raw materials. Compared with the prior art, the device is composed of the nitrogen generator, the plasma discharge device, the fixed bed reactor and the absorption tower, sliding arc discharge is adopted, the fixed bed reactor is heated through heat generated by discharge, NH3 and NOx are synthesized through nitrogen and water discharge, and the ammonium nitrate solution is finally obtained through oxidation absorption. According to the method, only air and water are used as raw materials, high-temperature and high-pressure reaction conditions in the industrial ammonium nitrate synthesis process are avoided, the synthesis process driven only by renewable energy sources is realized, and the method can be applied to the scenes of distributed energy storage, small-scale production of agricultural nitrogen fertilizers and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial nitrogen fixation, and in particular relates to a device and a method for producing ammonium nitrate using air and water as raw materials. Background Art

[0002] Ammonium nitrate has a high nitrogen content and is inexpensive. It is an ideal nitrogen fertilizer and can also be used to make pesticides, refrigerants, etc. The traditional industrial synthesis of ammonium nitrate requires the use of NH3 prepared by the Haber process as a raw material. NH3 is oxidized to NO by a catalyst at 800-900 degrees Celsius, and nitric acid is obtained by oxidation and absorption. Nitric acid is then synthesized by the neutralization reaction of nitric acid and NH3. This process is highly centralized and relies on large-scale synthetic ammonia plants and hydrogen production plants. It is difficult to apply in remote areas such as plateaus and deep mountains. In addition, as an explosive substance, ammonium nitrate also has great safety hazards in its storage and transportation. Water and air are widely present in the earth's environment. If it is possible to directly use water and air as raw materials under mild conditions, ammonium nitrate can be produced and used at the place of use, and decentralized ammonium nitrate production can be achieved, the above problems can be effectively solved.

[0003] In recent years, with the development of clean power technologies such as photovoltaic power generation, electricity-driven plasma technology has received widespread attention. In the nitrogen plasma reaction, nitrogen molecules collide with high-energy electrons generated by the discharge and can be activated to an excited state or even a dissociated state. Therefore, plasma technology is an effective means of activating nitrogen. The use of plasma discharge in combination with other technologies to produce ammonium nitrate has attracted attention (Yu et al., Joule, 2023, 7, 1-8). However, current research uses air discharge to generate nitrogen oxides (NO x ), then change NO x The method is mainly to absorb the ammonium nitrate with electrolyte and then electrocatalytically reduce it to NH3. This method is complicated to operate, and the ammonium nitrate needs to be separated from the electrolyte, which increases the steps and cost of the synthesis. Therefore, it is necessary to develop a simpler ammonium nitrate synthesis route using water and air as raw materials. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a device and method for producing ammonium nitrate using air and water as raw materials by utilizing plasma discharge and thermal catalysis technology.

[0005] The present invention provides a device for producing ammonium nitrate using air and water as raw materials, comprising: a nitrogen generator, a plasma discharge device, a fixed bed reactor and an absorption tower;

[0006] The nitrogen generator is connected to the plasma discharge device;

[0007] The plasma discharge device is provided with a water vapor inlet and a gas outlet;

[0008] The gas outlet of the plasma discharge device is connected to the inlet of the fixed bed reactor;

[0009] The fixed bed reactor is provided with a hydrogenation catalyst and a reducing gas outlet;

[0010] The reducing gas outlet of the fixed bed reactor is communicated with the absorption tower.

[0011] Preferably, the plasma discharge device is a sliding arc plasma discharge device;

[0012] The absorption tower is provided with an oxidizing gas inlet.

[0013] The present invention also provides a method for producing ammonium nitrate using air and water as raw materials, comprising the following steps:

[0014] S1) treating air with a nitrogen generator to obtain nitrogen;

[0015] S2) mixing water vapor and nitrogen and subjecting the mixture to plasma discharge treatment to obtain a reaction gas;

[0016] S3) treating the reaction gas with a hydrogenation catalyst to obtain a reducing gas;

[0017] S4) The reducing gas is absorbed by an absorption liquid to obtain a solution containing ammonium nitrate.

[0018] Preferably, the molar amount of the water vapor is 1% to 50% of the total molar amount of the water vapor and the nitrogen.

[0019] Preferably, the total flow rate of water vapor and nitrogen during the plasma discharge treatment is 2 to 10 slm; the discharge current of the plasma discharge treatment is 0.1 to 10 A; the discharge voltage of the plasma discharge treatment is 150 to 1000 V; and the discharge power of the plasma discharge treatment is 15 to 10000 W.

[0020] Preferably, the hydrogenation catalyst in step S3) comprises a carrier and precious metal particles loaded on the carrier; the precious metal particles are selected from platinum or palladium; the mass concentration of the precious metal particles in the hydrogenation catalyst is 0.1% to 5%;

[0021] The temperature of the catalytic treatment in step S3) is 100°C to 300°C.

[0022] Preferably, an oxidizing gas is also added in step S4); the reducing gas and the oxidizing gas are mixed and absorbed by liquid to obtain a solution containing ammonium nitrate.

[0023] Preferably, the volume flow rate of the oxidizing gas is 0.1 to 5 times the volume flow rate of the reducing gas.

[0024] Preferably, the molar ratio of nitrate ions to ammonium ions in the ammonium nitrate-containing solution is 0.8 to 2:1.

[0025] Preferably, the ammonium nitrate-containing solution obtained after the reducing gas is absorbed by the absorption liquid in step S4) comprises ammonium ions, nitrate ions and nitrite ions; the total molar amount of the nitrate ions and nitrite ions is less than or equal to 1 / 4 of the molar amount of the ammonium ions.

[0026] Compared with the prior art, the device provided by the present invention consists of a nitrogen generator, a plasma discharge device, a fixed bed reactor and an absorption tower, adopts sliding arc discharge, and uses the heat generated by the discharge to heat the fixed bed reactor, thereby realizing the synthesis of NH3 and NO by nitrogen and water discharge. x , and finally obtain ammonium nitrate solution by oxidation absorption. This method only uses air and water as raw materials, and avoids the high temperature and high pressure reaction conditions in the industrial synthesis of ammonium nitrate, realizing a synthesis process driven only by renewable energy. It can be applied to distributed energy storage, small-scale production of agricultural nitrogen fertilizers and other scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of an apparatus for producing ammonium nitrate using air and water as raw materials provided by the present invention;

[0028] Figure 2 A schematic diagram of the structure of a plasma-fixed bed coupled reactor provided by the present invention;

[0029] Figure 3 The following are photos and XRD diagrams of the solution obtained in Example 1 of the present invention after evaporation. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] The present invention provides a device for producing ammonium nitrate using air and water as raw materials, comprising: a nitrogen generator, a plasma discharge device, a fixed bed reactor and an absorption tower;

[0032] The nitrogen generator is connected to the plasma discharge device;

[0033] The plasma discharge device is provided with a water vapor inlet and a nitrogen oxide gas outlet;

[0034] The nitrogen oxide gas outlet of the plasma discharge device is connected to the inlet of the fixed bed reactor;

[0035] The fixed bed reactor is provided with a hydrogenation catalyst and a reducing gas outlet;

[0036] The reducing gas outlet of the fixed bed reactor is communicated with the absorption tower.

[0037] See also Figure 1 , Figure 1 The present invention provides a schematic structural diagram of an apparatus for producing ammonium nitrate using air and water as raw materials.

[0038] The device for producing ammonium nitrate provided by the present invention includes a nitrogen generator; the function of the nitrogen generator is to separate oxygen from the air to obtain high-purity nitrogen for subsequent reactions. The principle of the nitrogen generator can be pressure swing adsorption, membrane separation, electrocatalytic oxygen reduction, etc. As long as it is a device that can separate nitrogen from the air, it can be used as the nitrogen generator in the present invention.

[0039] The nitrogen generator is connected to the plasma discharge device, and the nitrogen generated by the nitrogen generator is passed into the plasma discharge device; the plasma discharge device is provided with a water vapor inlet; in the plasma discharge device, the nitrogen reacts with the water vapor to generate nitrogen oxides (NO x , mainly including NO and NO2) and H2; the plasma discharge device is preferably a sliding arc plasma discharge device; specifically, the plasma discharge device includes a discharge electrode; the discharge electrode is composed of a rod-shaped high-voltage electrode with a conical tip and an annular outer electrode; there is no special restriction on the inner diameter and length of the annular outer electrode, as long as it is an annular electrode that can induce gas plasma discharge, it can be used as the discharge electrode of the plasma discharge device in the present invention.

[0040] The plasma discharge device is provided with a gas outlet, which is connected to the solid bed reactor through the gas outlet; a hydrogenation catalyst is provided in the fixed bed reactor; the hydrogenation catalyst can be any hydrogenation catalyst well known to those skilled in the art, without any special restrictions, and preferably includes a carrier and precious metal particles loaded on the carrier in the present invention; the carrier can be any carrier well known to those skilled in the art, without any special restrictions, and preferably metal oxides, non-metal oxides, zeolite molecular sieves, etc., more preferably one or more of silicon dioxide, aluminum oxide, titanium dioxide, HZSM5 zeolite, NaY zeolite, etc.; the present invention is for the carrier The morphology and particle size of the precious metal particles are not particularly limited, and may be amorphous particles, nanocrystals with specific crystal faces, etc.; the precious metal particles are preferably platinum and / or palladium, more preferably platinum; the present invention has no particular restrictions on the size of the precious metal particles and the exposed crystal faces; the mass concentration of the precious metal particles in the hydrogenation catalyst is preferably 0.1% to 5%, specifically 0.1%, 0.5%, 1%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% or a range between any two of the above values; in the embodiments provided by the present invention, 0.5% to 1% is specifically used as an example for explanation; under the action of the hydrogenation catalyst, NO x Reacts with H2 to form NH3.

[0041] In a specific embodiment provided by the present invention, the plasma discharge device and the fixed bed reactor can be provided by a device including both a plasma discharge device and a fixed bed reactor, that is, a plasma-fixed bed coupled reactor. Specifically, the plasma-fixed bed coupled reactor includes a plasma discharge region and a fixed bed reaction region, the plasma discharge region is located below the fixed bed reaction region, a discharge electrode is arranged in the plasma discharge region, and a hydrogenation catalyst is arranged in the fixed bed reaction region; further specifically, the discharge electrode is composed of a rod-shaped high-voltage electrode with a conical tip and an annular outer electrode, and the rod-shaped high-voltage electrode is located at the bottom of the plasma discharge region, opposite to the fixed bed reaction region; the use of a plasma-fixed bed coupled reactor allows the fixed bed reactor to be heated to a temperature suitable for the reaction without an external heat source, and the heat generated by the discharge reaction in the plasma discharge device can be heated to a temperature suitable for the reaction. There is no clear restriction on the distance between the plasma discharge electrode and the fixed bed reactor region and the shape of the connecting pipeline in the plasma-fixed bed coupled reactor. As long as the device structure can effectively use the heat generated by the plasma discharge to heat the fixed bed reactor, it can be used as the structure of the chelating reactor in the present invention. In addition, the reactor can also be additionally provided with a heating function for rapid temperature adjustment. After water and nitrogen pass through a plasma-fixed bed coupled reactor, the product gas is NO x and NH3.

[0042] In a specific embodiment provided by the present invention, the plasma-fixed bed coupled reactor further comprises a water storage chamber, see Figure 2 , Figure 2 The present invention provides a schematic structural diagram of a plasma-fixed bed coupled reactor, wherein 1 is an air inlet, 2 is a water storage chamber, 3 is a rod-shaped electrode with a conical tip, 4 is an annular outer electrode, 5 is a plasma moment generated by discharge, 6 is a catalyst filling layer, and 7 is an air outlet; the nitrogen generator is connected to a plasma discharge region in the plasma-fixed bed coupled reactor through the water storage chamber, and the water vapor in the water storage chamber is brought into the plasma discharge region by the nitrogen generated by the nitrogen generator; in order to improve energy utilization efficiency, the heat generated in the plasma discharge region can be used to heat the liquid water in the water storage chamber to promote the formation of water vapor in addition to being used to heat the fixed bed reaction region.

[0043] The reducing gas outlet of the fixed bed reactor is connected to the absorption tower. Preferably, the reducing gas outlet of the fixed bed reactor is connected to the absorption tower via a cooling device. The reducing gas catalyzed by the hydrogenation catalyst in the fixed bed reactor contains ammonia, water vapor and NO. x , the reducing gas can be cooled before entering the absorption tower to condense and separate the water vapor therein, thereby increasing the oxidation rate and improving the oxidation absorption effect. Further preferably, the absorption tower is provided with an oxidizing gas inlet; the oxidizing gas can be any oxidizing gas known to those skilled in the art without any special limitation, and in the present invention, air and / or oxygen are preferred; the reducing gas generated in the fixed bed reactor is introduced into the absorption tower together with the oxidizing gas. Under the action of O2, the excess NO x It will be oxidized to NO2, and finally absorbed together with NH3 to form ammonium nitrate solution. The absorption tower is an absorption tower well known to those skilled in the art, and can be any type of device that can fully absorb the gas, such as a plate tower, a bubbling tower, a packed tower, a spray tower, etc.

[0044] The present invention also provides a method for producing ammonium nitrate using air and water as raw materials, comprising the following steps: S1) treating air with a nitrogen generator to obtain nitrogen; S2) mixing water vapor with nitrogen and treating it with plasma discharge to obtain a reaction gas; S3) catalytically treating the reaction gas with a hydrogenation catalyst to obtain a reducing gas; S4) absorbing the reducing gas with an absorption liquid to obtain a solution containing ammonium nitrate.

[0045] The present invention has no particular limitation on the sources of all raw materials, and any raw materials available on the market can be used.

[0046] The air is treated by a nitrogen generator to obtain nitrogen.

[0047] The water vapor and nitrogen are mixed and subjected to plasma discharge treatment to obtain a reaction gas; the molar amount of the water vapor is preferably 1% to 50% of the total molar amount of the water vapor and the nitrogen, and can be specifically 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or a range between any two of the above values; in the embodiment provided by the present invention, it is specifically 30% to 40%; the total flow rate of the water vapor and the nitrogen during the plasma discharge treatment is preferably 2 to 10 slm, and can be specifically 2 slm, 4 slm, 5slm, 6slm, 8slm or the range between any two of the above values; in the embodiment provided by the present invention, 4 to 8slm is specifically used as an example for explanation; the discharge current of the plasma discharge treatment is preferably 0.1 to 10A, specifically 0.1A, 0.2A, 0.5A, 1A, 2A, 3A, 5A, 8A, 10A or the range between any two of the above values; in the embodiment provided by the present invention, 0.2 to 1A is specifically used as an example for explanation; the discharge voltage of the plasma discharge treatment is preferably 150 to 1 000V, specifically 150V, 200V, 250V, 300V, 350V, 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V, 900V, 950V, 1000V or a range between any two of the above values; in the embodiments provided by the present invention, 600-700V, 650-700V or 700-800V is specifically used as an example for illustration; the discharge power of the plasma discharge treatment is preferably 15-10 000W, specifically 15W, 50W, 100W, 150W, 200W, 250W, 300W, 320W, 350W, 370W, 400W, 450W, 500W, 550W, 600W, 700W, 800W, 1000W, 1500W, 2000W, 3000W, 4000W, 5000W, 10000W or a range between any two of the above values; in the embodiments provided by the present invention, 320W, 200W or 370W is specifically taken as an example for description. NO generated by plasma discharge treatment x The molar concentration of NO and H2 is 0.2% to 2.5%, and the molar ratio is x / H2 is 0.7-1.1, and discharge will also produce NH3 and N2O with concentrations below 500ppm and 500ppm, respectively.

[0048] The reaction gas is treated by a hydrogenation catalyst to obtain a reducing gas; the hydrogenation catalyst can be any hydrogenation catalyst known to those skilled in the art without any special restrictions, and preferably includes a carrier and precious metal particles loaded on the carrier in the present invention; the carrier can be any carrier known to those skilled in the art without any special restrictions, and preferably is a metal oxide, a non-metal oxide, a zeolite molecular sieve, etc., more preferably one or more of silicon dioxide, aluminum oxide, titanium dioxide, HZSM5 zeolite, NaY zeolite, etc.; the precious metal particles are preferably platinum and / or palladium, more preferably platinum; the mass concentration of the precious metal particles in the hydrogenation catalyst is preferably 0.1% to 5%, and most preferably 0 .5% to 1%; the ratio of the reaction gas to the hydrogenation catalyst is preferably (2 to 10) slm: (1 to 10) g, more preferably (4 to 8) slm: (3 to 4) g; in some embodiments provided by the present invention, the ratio of the reaction gas to the hydrogenation catalyst is specifically 5 slm: 3 g or 8 slm: 3 g; the temperature of the catalytic treatment is preferably 100°C to 300°C, more preferably 150°C to 250°C, optionally 150°C, 180°C, 200°C, 250°C or a range between any two of the above values; after catalytic treatment with the hydrogenation catalyst, the conversion rate of H2 is 70% to 100%, and the final concentration of NH3 in the gas is 0.1% to 1%.

[0049] In a specific embodiment provided by the present invention, the total time of the plasma discharge treatment and the catalytic treatment may be 5 to 60 min, optionally 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min or a range between any two of the above values.

[0050] In a specific embodiment provided by the present invention, the reducing gas is absorbed by an absorption liquid to obtain a solution containing ammonium nitrate; the absorption liquid can be an aqueous medium well known to those skilled in the art, without any special restrictions, and is preferably water in the present invention; the obtained solution containing ammonium nitrate is mainly an ammonia-containing solution, and specifically preferably includes ammonium ions, nitrate ions and nitrite ions; the total molar amount of the nitrate ions and nitrite ions is less than or equal to 1 / 4 of the molar amount of the ammonium ions.

[0051] In another specific embodiment provided by the present invention, an oxidizing gas is further added; the reducing gas and the oxidizing gas are mixed, and after being absorbed by the absorption liquid, a solution containing ammonium nitrate is obtained; under the action of O2, the excess NO xIt will be oxidized to NO2, and finally absorbed together with NH3 to form ammonium nitrate solution; the oxidizing gas can be any oxidizing gas known to those skilled in the art without any special limitation, and is preferably air and / or oxygen in the present invention; the volume flow rate of the oxidizing gas is preferably 0.1 to 5 times the volume flow rate of the reducing gas; optionally, the volume flow rate of the oxidizing gas is 0.1 times, 0.5 times, 0.8 times, 1 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times or more of the volume flow rate of the reducing gas. The range is between any two values; in the embodiment provided in the present invention, 1 to 2 times is specifically used as an example for explanation; the absorption liquid can be an aqueous medium well known to those skilled in the art, without any special restrictions, and is preferably water in the present invention; the molar ratio of nitrate ions to ammonium ions in the ammonium nitrate-containing solution obtained by introducing an oxidizing gas is 0.8 to 2:1; the concentration of the ammonium nitrate-containing solution can increase with the extension of the absorption time until saturation, and the absorption time can be selected according to actual use requirements, or the water in the solution can be evaporated to obtain ammonium nitrate solid.

[0052] As can be seen from the above, in the method provided by the present invention, the solution obtained without introducing an oxidizing gas is mainly ammonia-containing solution with very little nitrate and nitrite. Only when an oxidizing gas is added can a large amount of nitrate be obtained.

[0053] According to the present invention, the gas which has not completely reacted during the oxidation absorption process can be circulated to continue the oxidation absorption process.

[0054] In the present invention, in order to obtain other types of nitrates, other substances such as carbonates, sulfates, phosphates, calcium salts, potassium salts, etc. can be added to the obtained ammonium nitrate-containing solution to obtain a solution containing multiple components, and solid substances can also be obtained by evaporation and granulation.

[0055] The method provided by the present invention has fewer synthesis steps, uses air and water as raw materials, consumes only renewable energy, does not require the high temperature and high pressure reaction conditions of the Haber process for synthesizing NH3 and ammonia oxidation for NO production, can directly produce ammonium nitrate under electric drive, and the reaction is continuous and easy to scale up. In addition, plasma discharge realizes efficient activation and conversion of nitrogen, is easy to operate, and is easy to meet larger-scale production needs, and is easy to promote to application scenarios such as distributed irrigation and small-scale production of nitrogen fertilizers, and reduces the danger of ammonium nitrate transportation and storage processes.

[0056] In order to further illustrate the present invention, a device and method for producing ammonium nitrate using air and water as raw materials provided by the present invention are described in detail below in conjunction with embodiments.

[0057] The reagents used in the following examples are all commercially available; Figure 2 The plasma-fixed bed coupled reactor is shown.

[0058] Example 1

[0059] The reaction gas is nitrogen containing 30% molar concentration of water vapor, the flow rate is 5slm, the discharge current is 0.5A, the voltage is 600-700V, the power is about 320W, and the reactor is filled with 3g of 0.5% mass fraction Pt / Al2O3 catalyst. When the temperature of the cavity in the plasma-fixed bed coupled reactor is stabilized at 180 degrees, after 30 minutes of discharge, the gas after passing through the catalyst is mixed with oxygen and passed into the absorption tower. The absorption tower is a plate tower, and the absorption liquid is water. The flow rate of the gas after passing through the catalyst is 5slm, and the flow rate of oxygen is 5slm. The concentration of ammonium nitrate in the obtained solution is 0.0265molL -1 The resulting solution was 280 mL in total.

[0060] The solution obtained in Example 1 was evaporated to dryness and analyzed by X-ray diffraction. The photo and XRD pattern were as follows: Figure 3 shown.

[0061] Example 2

[0062] The reaction gas is nitrogen containing 30% molar concentration of water vapor, the flow rate is 5slm, the discharge current is 0.3A, the voltage is 650-700V, the power is about 200W, and the reactor is filled with 3g of 0.5% mass fraction Pt / TiO2 catalyst. When the cavity temperature of the plasma-fixed bed coupled reactor is stabilized at 150 degrees, after 30 minutes of discharge, the gas after passing through the catalyst is mixed with air and passed into the absorption tower. The absorption tower is a plate tower, and the absorption liquid is water. The flow rate of the gas after passing through the catalyst is 5slm, and the flow rate of the air is 6slm. The concentration of ammonium nitrate in the obtained solution is 0.02molL -1 The resulting solution is 300 mL in total.

[0063] Example 3

[0064] The reaction gas is nitrogen containing 30% molar concentration of water vapor, the flow rate is 8slm, the discharge current is 0.5A, the voltage is 700-800V, the power is about 370W, and the reactor is filled with 3g of 1% mass fraction Pt / TiO2 catalyst. When the temperature of the cavity in the plasma-fixed bed coupled reactor is stabilized at 150 degrees, after 10 minutes of discharge, the gas after passing through the catalyst is mixed with air and passed into the absorption tower. The absorption tower is a plate tower, and the absorption liquid is water. The flow rate of the gas after passing through the catalyst is 8slm, and the flow rate of the air is 10slm. The concentration of ammonium nitrate in the obtained solution is 0.0185mol L -1 The resulting solution is 330 mL in total.

[0065] Example 4

[0066] The reaction gas is nitrogen containing 30% molar concentration of water vapor, the flow rate is 5slm, the discharge current is 0.5A, the voltage is 550-650V, the power is about 300W, and the reactor is filled with 3g of 0.5% mass fraction Pt / HZSM5 catalyst. When the temperature of the cavity in the plasma-fixed bed coupled reactor is stabilized at 240 degrees, after 30 minutes of discharge, the gas after passing through the catalyst is mixed with air and passed into the absorption tower. The absorption tower is a plate tower, and the absorption liquid is water. The flow rate of the gas after passing through the catalyst is 5slm, and the flow rate of the air is 4slm. The concentration of ammonium nitrate in the obtained solution is 0.05molL -1 The resulting solution was 260 mL in total.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for producing ammonium nitrate using air and water as raw materials, characterized in that: include: Nitrogen generator, plasma discharge device, fixed bed reactor and absorption tower; The nitrogen generator is connected to the plasma discharge device; The plasma discharge device is provided with a water vapor inlet and a gas outlet; The gas outlet of the plasma discharge device is connected to the inlet of the fixed bed reactor; The fixed bed reactor is provided with a hydrogenation catalyst and a reducing gas outlet; The reducing gas outlet of the fixed bed reactor is communicated with the absorption tower.

2. The device according to claim 1, characterized in that The plasma discharge device is a sliding arc plasma discharge device; The absorption tower is provided with an oxidizing gas inlet.

3. A method for producing ammonium nitrate using air and water as raw materials, characterized in that: The following steps are involved: S1) treating air with a nitrogen generator to obtain nitrogen; S2) mixing water vapor and nitrogen and subjecting the mixture to plasma discharge treatment to obtain a reaction gas; S3) treating the reaction gas with a hydrogenation catalyst to obtain a reducing gas; S4) The reducing gas is absorbed by an absorption liquid to obtain a solution containing ammonium nitrate.

4. The method according to claim 3, characterized in that The molar amount of the water vapor is 1% to 50% of the total molar amount of the water vapor and the nitrogen.

5. The method according to claim 3, characterized in that: The total flow rate of water vapor and nitrogen during the plasma discharge treatment is 2 to 10 slm; the discharge current of the plasma discharge treatment is 0.1 to 10A; the discharge voltage of the plasma discharge treatment is 150 to 1000V; and the discharge power of the plasma discharge treatment is 15 to 10000W.

6. The method according to claim 3, characterized in that In step S3), the hydrogenation catalyst comprises a carrier and precious metal particles loaded on the carrier; the precious metal particles are selected from platinum or palladium; the mass concentration of the precious metal particles in the hydrogenation catalyst is 0.1% to 5%; The temperature of the catalytic treatment in step S3) is 100°C to 300°C.

7. The method according to claim 3, characterized in that In the step S4), an oxidizing gas is also added; the reducing gas and the oxidizing gas are mixed and absorbed by liquid to obtain a solution containing ammonium nitrate.

8. The method according to claim 7, characterized in that The volume flow rate of the oxidizing gas is 0.1 to 5 times the volume flow rate of the reducing gas.

9. The method according to claim 8, characterized in that The molar ratio of nitrate ions to ammonium ions in the ammonium nitrate-containing solution is 0.8 to 2:

1.

10. The method according to claim 3, characterized in that The ammonium nitrate-containing solution obtained after the reducing gas is absorbed by the absorption liquid in step S4) includes ammonium ions, nitrate ions and nitrite ions; the total molar amount of the nitrate ions and nitrite ions is less than or equal to 1 / 4 of the molar amount of the ammonium ions.

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