Method for producing nitrogen monoxide and nitrogen monoxide produced by same method

Abstract

The present invention provides: a method for producing nitrogen monoxide comprising the steps of: (a) reacting NO2 and N2O3 with H2O; and b) recovering the gas produced by the reaction; and nitrogen monoxide produced by same method.

Description

Method for producing nitrogen monoxide and nitrogen monoxide produced by the method

[0001] The present invention relates to a method for safely and efficiently producing nitrogen monoxide and high-purity nitrogen monoxide produced by the method.

[0002] High-purity nitrogen monoxide is used in a variety of applications, including semiconductor gases and medical gases. When nitrogen monoxide is used as a semiconductor gas, a purity of 99.95% or higher is required.

[0003] Nitrogen monoxide is generally produced by ammonia oxidation, the reaction of sodium nitrite with sulfuric acid, or the reaction of sodium nitrite with ferric chloride. In the ammonia oxidation method, ammonia oxidation and the chemical reactions occurring simultaneously are as follows.

[0004] NH3+ 2O2→ HNO3+ H2O (preferred overall reaction)

[0005] 4NH3+ 7O2→ 4NO2+ 6H2O (preferred reaction equation when using excess O2)

[0006] 3NO2+ 3O2→ 2HNO3+ NO (preferred reaction equation in the NO2 absorption process)

[0007] 4NH3+ 3O2→ 2N2+ 6H2O (unfavorable reaction equation)

[0008] 4NH3+ 4O2→ 2N2O + 6H2O (unfavorable reaction equation)

[0009] 2NH3+ 8NO → 5N2O + 3H2O (unfavorable reaction equation)

[0010] When producing nitrogen monoxide using the ammonia oxidation process, various reactions, such as those described above, occur, resulting in low production efficiency. Furthermore, the requirement for high-purity ammonia increases manufacturing costs. Furthermore, the use of aqueous solutions such as KMnO4 to remove unreacted ammonia leads to high wastewater treatment costs.

[0011] Meanwhile, nitrogen monoxide is a thermodynamically unstable substance that reacts as follows to form nitrogen oxides (NOx). Therefore, the purity of nitrogen monoxide is reduced, making it difficult to purify high-purity nitrogen monoxide.

[0012] 2NO + O2→ 2NO2

[0013] NO2+ NO ↔ N2O3

[0014] 2NO2↔ N2O4

[0015] Conventional technologies typically utilize ultra-low temperature cooling to remove NxOy and NOx-based substances, thereby purifying and preserving nitrogen monoxide to a high purity. This means that ultra-low temperature cooling transforms gaseous nitrogen monoxide into a solid, and substances with lower boiling points than nitrogen monoxide remain in a gaseous state. This allows for the removal of gaseous impurities, leaving nitrogen monoxide in a solid state. However, the solid nitrogen monoxide obtained through this method must undergo a phase transformation to a gaseous state before use. This process increases the risk of explosion due to rapid volume expansion, and there have been actual explosions in the United States.

[0016] Furthermore, conventional nitrogen monoxide production methods are impractical for mass production due to environmental issues such as NOx gas emissions. Therefore, improvements to these issues are needed.

[0017] A prior patent related to the present invention is Republic of Korea Patent No. 10-1257794.

[0018] The present invention has been devised to solve the above problems of the prior art.

[0019] The purpose of the present invention is to provide a method for producing high-purity nitrogen monoxide with excellent safety and efficiency, which prevents the risk of explosion due to phase change of nitrogen monoxide, minimizes the generation of NOx gas, and enables recycling and use of by-products such as wastewater and waste gas, and to provide high-purity nitrogen monoxide produced by the method.

[0020] The present invention

[0021] a) a step of reacting NO2 and N2O3 with H2O; and

[0022] b) A method for producing nitrogen monoxide is provided, including a step of recovering NO gas produced by the above reaction.

[0023]

[0024] In addition, the present invention

[0025] 1) A step of removing a liquid phase by separating a mixed gas obtained from a process of producing nitric acid by reacting ammonia and oxygen into gas and liquid in a gas-liquid separator under conditions of a pressure of 3 to 20 bar and a temperature of 5 to 30°C;

[0026] 2) A step of condensing the mixed gas obtained from the above gas-liquid separation to obtain liquid NO2 and N2O3;

[0027] 3) A step of reacting the above NO2 and N2O3 with H2O; and

[0028] 4) A method for producing nitrogen monoxide is provided, including a step of recovering NO gas produced by the above reaction.

[0029]

[0030] In addition, the present invention

[0031] Nitrogen monoxide manufactured by the above method is provided.

[0032] According to the method for producing nitrogen monoxide of the present invention, the risk of explosion due to phase change of nitrogen monoxide is prevented, NOx gas generation is minimized, and byproducts such as wastewater and waste gas can be recycled and used, thereby significantly increasing the safety and efficiency of nitrogen monoxide production. In addition, high-purity nitrogen monoxide production is possible.

[0033] In addition, since the nitrogen monoxide of the present invention manufactured by the above method has a very high purity, it can be efficiently used in fields requiring high-purity nitrogen monoxide.

[0034] Figure 1 is a flow chart of the nitrogen monoxide production of the present invention.

[0035] Figure 2 illustrates one embodiment of a plant used for producing nitrogen monoxide of the present invention.

[0036] *Explanation of major symbols in the drawing

[0037] 100: Nitric acid production reactor

[0038] 200: Gas-liquid separator

[0039] 210: Heat exchanger

[0040] 300: Crude NO2 liquefaction device

[0041] 310: Heat exchanger

[0042] 400: Reactor

[0043] 500: Alkali absorption tower

[0044] 600: Washing Tower

[0045] 610: Heat exchanger

[0046] 700: Compressor

[0047] 800: Adsorption tower

[0048] 1100: Charging container

[0049] The present invention is described in detail below.

[0050] The method for producing nitrogen monoxide of the present invention is characterized by comprising the following steps.

[0051] a) a step of reacting NO2 and N2O3 with H2O; and

[0052] b) A step of recovering NO gas generated by the above reaction.

[0053] In one embodiment of the present invention, the reaction of step a) may be carried out under conditions of a pressure of 1 to 30 bar and a temperature of 10 to 100°C, preferably under conditions of a pressure of 1 to 25 bar and a temperature of 7 to 75°C, more preferably under conditions of a pressure of 7 to 25 bar and a temperature of 40 to 60°C, and even more preferably under conditions of a pressure of 15 to 25 bar and a temperature of 40 to 60°C. When carried out under the above conditions, NO can be obtained at a high yield, which is preferable.

[0054] In addition, in order to obtain high purity NO, it is preferable to perform the process under conditions of a pressure of 1 to 15 bar and a temperature of 40 to 60°C, and more preferably under conditions of a pressure of 1 to 10 bar and a temperature of 40 to 60°C.

[0055] Since the above NO2 also exists as N2O4, the part described as NO2 in the present invention should be understood as a concept including the existence of only NO2, the mixed form of NO2 and N2O4, and the existence of only N2O4.

[0056]

[0057] Nitric acid can be produced by the reaction of step a) above, and this nitric acid can be returned to the nitric acid manufacturing process.

[0058]

[0059] The above-mentioned manufactured nitrogen monoxide may have a purity of 80% or more and a yield of 40% or more; preferably, a purity of 90% or more and a yield of 50% or more; more preferably, a purity of 95% or more and a yield of 60% or more; and even more preferably, a purity of 98% or more and a yield of 10% or more or 70% or more.

[0060]

[0061] In addition, the method for producing nitrogen monoxide of the present invention is characterized by including the following steps.

[0062] 1) A step of removing a liquid phase by separating a mixed gas obtained from a process of producing nitric acid by reacting ammonia and oxygen into gas and liquid in a gas-liquid separator under conditions of a pressure of 3 to 20 bar and a temperature of 5 to 30°C;

[0063] 2) A step of condensing the mixed gas obtained from the above gas-liquid separation to obtain liquid NO2 and N2O3;

[0064] 3) A step of reacting the above NO2 and N2O3 with H2O; and

[0065] 4) A step of recovering NO gas generated by the above reaction.

[0066] Since steps 3) to 4) above can be performed in the same manner as described above, detailed descriptions are omitted.

[0067] The mixed gas generated in the process of producing nitric acid by reacting ammonia and oxygen in step 1) above is N 2, O 2, NO, N2O, NO 2, N2O 3, N2O 4, HNO 3, and may contain six or more of H2O, or may contain all of them.

[0068] In the above step 1), the mixed gas may be supplied to the gas-liquid separator at a pressure of 1 to 20 bar and a temperature of 20 to 150°C, preferably at a pressure of 1 to 10 bar and a temperature of 20 to 50°C. This is preferable because a large amount of NO2 can be supplied under the above conditions.

[0069] The gas-liquid separation in step 1) above can be performed by setting the gas-liquid separator to a pressure of 3 to 5 bar and a temperature of 5 to 30°C. When performed under the above conditions, a large amount of NO2 can be obtained, which is preferable.

[0070] Moisture and nitric acid can be removed by the gas-liquid separation of step 1), and the removed impurities can be returned to the nitric acid manufacturing process.

[0071]

[0072] In the above step 2), condensation can be performed under conditions of a pressure of 1 to 30 bar and a temperature of -30 to 5°C, preferably under conditions of a pressure of 3 to 20 bar and a temperature of -20 to -10°C. When performed under the above conditions, a large amount of NO2 and N2O3 can be obtained, which is preferable.

[0073] In step 2) above, NO2 and N2O3 are condensed, leaving N2, O2, NO, etc., which can be returned to the nitric acid manufacturing process and reused.

[0074]

[0075] In one embodiment of the present invention, the NO gas recovered in step b) or step 4) can be further purified through an alkaline solution washing step.

[0076] The above alkaline solution may be selected from the group consisting of KOH aqueous solution, NaOH aqueous solution, Ca(OH)2 aqueous solution, and Mg(OH)2 aqueous solution.

[0077] The above alkaline solution washing can be performed, for example, through an alkaline absorption tower. For example, by supplying NO gas upward from the bottom of the alkaline absorption tower and spraying an alkaline solution in the direction of the supplied NO gas from the top of the alkaline absorption tower, trace amounts of nitric acid and impurities such as CO and NO2 can be removed.

[0078]

[0079] In one embodiment of the present invention, after the alkaline solution washing step, a water washing process for NO gas may be further performed.

[0080] The above washing process can be performed, for example, through a washing tower. For example, by supplying NO gas upward from the bottom of the washing tower, water (e.g., distilled water) can be sprayed from the top of the washing tower in the direction of the supplied NO gas, thereby removing alkaline components.

[0081] In one embodiment of the present invention, after the washing step, a step of drying the NO gas may be further performed.

[0082] The above drying step can be performed using one or more adsorbents selected from the group consisting of zeolites 3A, 4A, 5A, and 13X. That is, the drying process can be performed by supplying NO gas to an adsorption tower equipped with the adsorbent.

[0083]

[0084] The present invention also provides:

[0085] Nitrogen monoxide manufactured by the above method is provided.

[0086] The nitrogen monoxide of the present invention, despite being manufactured by a very simple method, has the characteristic of excellent purity. That is, the nitrogen monoxide may have a purity of 80% or more, preferably 90% or more, more preferably 95% or more, and most preferably 98% or more.

[0087]

[0088] Hereinafter, the manufacturing method of the present invention will be specifically explained by way of example through the carbon monoxide manufacturing plant illustrated in FIG. 2.

[0089] Crude NO2 is supplied (10) at a pressure of 1 to 20 bar and a temperature of 20 to 500°C from a nitric acid manufacturing reactor (100) where a nitric acid manufacturing process takes place. At this time, the composition of the crude NO2 coming out at each stage of the nitric acid manufacturing process is different, and the content of NO2 included in the crude NO2 provided at this time is 1 to 99%, and the remaining components are N2, O2, N O, N2O, etc. The crude NO2 supplied in this way removes moisture through a gas-liquid separator (200) and a heat exchanger (210). At this time, not only moisture but also nitric acid is removed, and nitric acid and moisture account for about 1 to 99%, and nitric acid and moisture are removed at 50 to 99% depending on the temperature and pressure of the heat exchanger. The liquefied nitric acid and moisture are recycled (21) to the nitric acid production reactor (100) and used for nitric acid production. The crude NO2 gas (20) from which moisture and nitric acid have been removed is liquefied in a crude NO2 liquefaction device (300) and a heat exchanger (310), and at this time, NO2 (or N2O4) and N2O3 are condensed at 1 to 99%. The crude NO2 gas (31) remaining after NO2 (or N2O4) and N2O3 are condensed is mostly N2, O2, NO, etc., and is recycled (31) to the nitric acid production reactor (100) and used for nitric acid production. The NO2 (or N2O4) and N2O3 (30) liquefied in the crude NO2 liquefaction device (300) react with distilled water (40) in the reactor (400) to produce crude NO gas (41). The nitric acid generated during the production of the NO gas is supplied (42) to the nitric acid production reactor (100) and reused in the nitric acid process.

[0090] The generated NO gas (41) can be supplied to an alkaline absorption tower (500) to remove impurities such as trace amounts of nitric acid, CO, NO2, etc. The high-purity NO gas (50) from which impurities such as trace amounts of nitric acid, CO, NO2, etc. have been removed through the alkaline absorption tower (500) can be supplied to a washing tower (600) to perform washing. The wastewater (51, 61) generated from the alkaline absorption tower (500) and washing tower (600) is circulated to the nitric acid process and reused for nitric acid neutralization, etc. The high-purity NO (60) gas after the washing is compressed to 1 to 100 bar through a compressor (700) after removing moisture from the gas compressed in this way through an adsorption tower (800) and filled in a filling station (900). The filling pressure at this time is 20 to 100 bar.

[0091]

[0092] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by these examples. Those skilled in the art may appropriately modify or alter the following examples within the scope of the present invention.

[0093]

[0094] Example 1: Nitric acid process gas analysis

[0095] A mixed gas supplied from a nitric acid manufacturing process was analyzed at varying temperatures and pressures. The analysis was performed using FT-IR, GC, and wet analysis, and the results were as follows.

[0096] Press. (Bar)202010105511Temp. (℃)45020020050503015020Components(%)O24.82.722.720.4270.5630.7543.580.523N268. 4586.4490.7392.0890.7989.6680.5791.22H2O16.770.630.630.520.9141.02210.550.777NO 5.787.0243.0251.582.1532.7584.122.12NO23.262.362.0165.095.3664.9851.085.06N2O0 .80.6670.86310.1530.1870.6460.020.288HNO30.140.1590.01590.150.0270.1750.080.012

[0097]

[0098] Example 2: NO2 (or N2O4) gas-liquid separation

[0099] The mixed gas analyzed in Example 1 was supplied and gas-liquid separation was performed. At this time, the gas-liquid separator was operated at a pressure of 3 to 5 bar and a temperature of 5 to 30°C, and a heat exchanger was installed on the top of the gas-liquid separator to maintain the above temperature. After the gas-liquid separation, component analysis was performed through GC, FT-IR, and wet analysis, and the analysis results are as shown in Tables 2 and 3 below.

[0100]

[0101] Press. (Bar)Temp. (℃)Components (%)O2N2H2ONONO2(or N2O4)N2OHNO3550Feed (Gas)0.56390.790.9142.1535.3660.1870.02755Gas-Liquid SeparationGas0.65091.790.0152.3294.9170.2950.002Liq.0.0000.01212.480.05286.120.0431.298510Gas-Liquid SeparationGas0.64390.820.0262.3055.9150.2930.002Liq.0.0000.01115.930.04182.300.0341.681520Gas-Liquid SeparationGas0.63289.290.0722.2687.4480.2890.003Liq.0.0000.01028.190.02568.350.0183.405530Gas-LiquidSeparationGas0.62688.440.1732.2468.2300.2860.001Liq.0.0000.00847.930.01343.590.0088.44535Gas-LiquidSeparationGas0.64390.740.0262.3045.9890.2930.002Liq.0.0000.00916.300.03981.890.0271.728310Gas-Liquid SeparationGas0.63789.870.0442.2826.8740.2900.002Liq.0.0000.00921.910.03175.590.0202.436320Gas-Liquid SeparationGas0.62888.710.1182.2538.0040.2870.001Liq.0.0000.00739.980.01854.060.0095.927

[0102] Press. (Bar)Temp. (℃)Components (%)O2N2H2ONONO2(or N2O4)N2OHNO320200Feed (Gas)2.7286.440.637.0242.360.6670.159205Gas-Liquid SeparationGas3.08185.730.0087.4582.6841.0360.001Liq.0.0010.01618.700.22360.570.18220.302010Gas-Liquid SeparationGas3.06685.300.0147.4223.1641.0320.001Liq.0.0010.01224.540.14647.100.13228.072020Gas-Liquid SeparationGas3.05384.950.0297.3933.5421.0290.003Liq.0.0010.00932.680.07227.060.09040.102030Gas-LiquidSeparationGas3.04884.810.0547.3823.6681.0280.009Liq.0.0000.00736.150.03916.430.07447.29105Gas-LiquidSeparationGas3.06085.140.0167.4093.3401.0310.001Liq.0.0010.00827.800.11139.320.08532.671010Gas-Liquid SeparationGas3.05584.990.0237.3963.5091.0300.002Liq.0.0000.00631.830.07929.350.07038.661020Gas-Liquid SeparationGas3.04984.830.0467.3833.6601.0280.006Liq.0.0000.00536.090.04217.080.05546.72

[0103]

[0104] Example 3: Condensation of NO2 (or N2O4) and N2O3

[0105] In Example 2, the mixed gas obtained after gas-liquid separation was condensed in a condenser under the conditions of 1 to 20 bar and temperature -20 to 5℃ to condense NO2 (or N2O4) and N2O3. A heat exchanger was installed on the top of the condenser to maintain the temperature, and the gas generated during this process was supplied to the nitric acid process and used to produce nitric acid. After the condensation process, component analysis was performed through GC, FT-IR, and wet analysis, and the analysis results are as shown in Tables 4 and 5 below.

[0106] Press. (Bar)Temp. (℃)Components (%)O2N2H2ONONO2(or N2O4)+N2O3N2OHNO355Feed (Gas)0.65091.790.0152.3294.9170.2950.0025-20Gas-Liquid SeparationGas0.67495.140.0002.4081.4780.3010.000Liq.0.0000.0200.4350.16699.210.1250.0455-10Gas-Liquid SeparationGas0.66593.880.0002.3802.7720.3000.000Liq.0.0000.0150.6770.09999.040.0980.06850Gas-LiquidSeparationGas0.65292.090.0042.3364.6260.2960.001Liq.0.0000.0123.6800.06095.870.0690.3123-20Gas-LiquidSeparationGas0.67194.660.0002.3981.9690.3010.000Liq.0.0000.0150.5030.12299.210.0930.0513-10Gas-Liquid SeparationGas0.65993.020.0012.3593.6600.2980.000Liq.0.0000.0111.1080.07398.630.0710.10730Gas-Liquid SeparationGas0.65091.790.0152.3294.9150.2950.002Liq.0.0000.01012.9330.05085.530.0341.443

[0107]

[0108] Press. (Bar)Temp. (℃)Components (%)O2N2H2ONONO2(or N2O4)+N2O3N2OHNO3205Feed (Gas)3.08185.730.0087.4582.6841.0360.00120-20Gas-Liquid SeparationGas3.14387.460.0007.5870.7751.0400.000Liq.0.0030.0380.4221.04597.600.8320.05620-10Gas-Liquid SeparationGas3.12186.840.0007.5461.4511.0410.000Liq.0.0020.0290.6420.62697.960.6570.084200GasLiquidSeparationGas3.08985.930.0027.4742.4641.0370.000Liq.0.0020.0232.8860.38095.910.4840.31910-20GasLiquid SeparationGas3.13087.090.0007.5651.1711.0440.000Liq.0.0020.0230.5310.66398.170.5420.07010-10Gas-Liquid SeparationGas3.09886.200.0017.4962.1631.0390.000Liq.0.0010.0181.4270.39997.570.4120.174100Gas-Liquid SeparationGas3.08185.730.0087.4582.6841.0360.001Liq.0.0000.0000.0000.0000.0000.0000.000

[0109]

[0110] Example 4: Reaction of NO2 (or N2O4) and N2O3 with water (NO production reaction)

[0111] Liquid NO2 (or N2O4) and N2O3 from Example 3 were reacted with water to produce NO. During the reaction, the pressure was maintained at 1 to 10 bar and the temperature at 20 to 100°C to produce NO. The composition of the NO gas obtained through the reaction was analyzed using FT-IR and wet analysis, and the results are shown in Table 6 below.

[0112] Press. (bar)Temp. (℃)Sele. (%)Yield (%)202097.1740.86205088.5772.492010079.1170.12102096.8833.89105097.2265.571010082.7667.8152098.4420.8755098.7143.51510090.4647.5512098.8415.2215098.0123.87110094.7336.32

Claims

1. a) NO 2 Wow N 2 O 3 To H 2 Step of reacting with O; and b) A method for producing nitrogen monoxide, comprising a step of recovering NO gas produced by the above reaction.

2. In paragraph 1, A method for producing nitrogen monoxide, characterized in that the reaction of step a) above is performed under conditions of a pressure of 1 to 30 bar and a temperature of 10 to 100°C.

3. In paragraph 2, A method for producing nitrogen monoxide, characterized in that the reaction of step a) above is performed under conditions of a pressure of 1 to 25 bar and a temperature of 10 to 75°C.

4. In paragraph 3, A method for producing nitrogen monoxide, characterized in that the reaction of step a) above is performed under conditions of a pressure of 1 to 15 bar and a temperature of 40 to 60°C.

5. In paragraph 4, A method for producing nitrogen monoxide, characterized in that the reaction of step a) above is performed under conditions of a pressure of 1 to 10 bar and a temperature of 40 to 60°C.

6. In paragraph 1, A method for producing nitrogen monoxide, characterized in that the above-mentioned produced nitrogen monoxide has a purity of 95% or higher and a yield of 10% or higher. 7.1) A step of removing the liquid phase by separating the gas mixture obtained from the process of producing nitric acid by reacting ammonia and oxygen in a gas-liquid separator under the conditions of a pressure of 3 to 20 bar and a temperature of 5 to 30°C; 2) Condensing the mixed gas obtained from the above gas-liquid separation to produce liquid NO. 2 Wow N 2 O 3 Steps to obtain ; 3) The above NO 2 Wow N 2 O 3 To H 2 Step of reacting with O; and 4) A method for producing nitrogen monoxide, comprising a step of recovering NO gas produced by the above reaction.

8. In paragraph 7, A method for producing nitrogen monoxide, characterized in that in step 1), the mixed gas is supplied to the gas-liquid separator at a pressure of 1 to 20 bar and a temperature of 20 to 150°C.

9. In paragraph 7, A method for producing nitrogen monoxide, characterized in that the gas-liquid separation in step 1) above is performed by setting the gas-liquid separator to a pressure of 3 to 5 bar and a temperature of 5 to 30°C.

10. In paragraph 7, A method for producing nitrogen monoxide, characterized in that the condensation in step 2) above is performed under conditions of a pressure of 1 to 30 bar and a temperature of -30 to 5°C.

11. In paragraph 10, A method for producing nitrogen monoxide, characterized in that the condensation in step 2) above is performed under conditions of a pressure of 3 to 20 bar and a temperature of -20 to -10°C.

12. In paragraph 7, A method for producing nitrogen monoxide, characterized in that the gas not condensed in step 2) above is returned to the nitric acid production process.

13. Nitrogen monoxide manufactured by the method of paragraph 1.

14. In paragraph 13, Nitrogen monoxide characterized by a purity of 95% or more.

15. In paragraph 13, Nitrogen monoxide characterized by a purity of 98% or more.

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