A method for resource utilization of N2O in adipic acid tail gas

Abstract

The present application relates to a kind of resource utilization method of N2O in adipic acid tail gas, under the condition of not using catalyst, still can N2O in adipic acid tail gas is handled, and further production has industrial value nitric acid and will not cause impact to environment nitrogen and oxygen, in reaching to N2O in adipic acid tail gas is handled while generating economic benefits, and process is simple, N2O removal rate is high, stability is high, environment-friendly and resource utilization rate is high, tail gas catalytic treatment can also be substantially reduced the cost of processing.And the method of the present application can be continuously operated, can continuously solve adipic acid industrial tail gas emission problem, so that it reaches industrial emission standard, reduces the cost of enterprise processing tail gas, has important practical significance and engineering application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tail gas resource utilization, and particularly relates to a method for resource utilization of N2O in adipic acid tail gas. BACKGROUND

[0002] Adipic acid is an important organic dibasic acid, which plays an important role in organic synthesis and chemical production. The production process of adipic acid adopts nitric acid oxidation method, and the tail gas contains high concentration of N2O, with a volume content of about 35%-39%, which is an important source of human-produced N2O. As one of the six greenhouse gases, N2O has a global warming potential (GWP) of 310 times that of CO2, and can also seriously damage the ozone layer, endangering human health and the ecological environment. Therefore, controlling the emission of N2O in adipic acid tail gas has attracted widespread attention.

[0003] At present, the processes for controlling the emission of N2O in adipic acid tail gas include thermal decomposition, direct catalytic decomposition and selective reduction technology. Among them, the direct catalytic decomposition technology is the most widely used, which uses noble metal, transition metal oxide, molecular sieve and other catalysts to decompose N2O into N2 and O2 at a window temperature of 450-550℃. However, this process has problems such as high reaction temperature, narrow temperature window, low selectivity of catalyst and deactivation, and does not consider the resource utilization of N2O.

[0004] CN 104437499 A discloses a catalyst for decomposing nitrous oxide and a preparation method thereof, which is prepared by a precipitation deposition method. The method includes the preparation of precipitate, washing, molding of precipitate and catalyst activation processes. The catalyst uses one or more than two of Co, Ni, Fe and Mn as active components, zirconium oxide as carrier, and one or more than one of cerium oxide, lanthanum oxide and barium oxide as auxiliary agent. It is suitable for removing N2O in nitric acid plants and adipic acid plants.

[0005] CN 114984749 A discloses a high-efficiency and energy-saving nitrous gas emission reduction process method, which includes multiple catalytic emission reduction components, including an N2O emission reduction reaction unit and a NO x emission reduction reaction unit. The device imports adipic acid plant process gas and compressed air, and after catalytic emission reduction treatment, it becomes harmless N2 and O2 to the atmosphere. However, this process generates N2 and O2 with low utilization value, and if pure nitrogen or oxygen is to be separated, new devices need to be added for separation, which is high in cost.

[0006] CN 109499357 A discloses a method for treating nitrous oxide emissions in industrial devices. The method is based on a nitric acid oxidation furnace basic device, and a "spider web" shaped platinum catalyst is loaded on the bracket to convert N2O generated in the production of nitric acid into N2 and O2, NO2 and NO. Although the technology mentioned in the technical solution mixes air and ammonia gas and then removes nitrous oxide through the oxidation furnace, platinum catalyst is still used to catalyze the reaction, and there are a series of problems such as the conversion device cannot run for a long time, the catalyst needs to be replaced regularly, or the conversion rate is reduced after the catalyst is deactivated.

[0007] CN 1045277 C discloses a method for generating NO from a gas stream containing N2O. The method specifically discloses that the temperature of the mixed gas containing N2O and hydrocarbon gas (methane) is heated to at least 1000℃ to generate NO, and the generated NO is then used to produce nitric acid. The structure and material of the heat exchanger are also limited. However, the generated NO is slightly soluble in water and unstable, and the final effect of using the recovered NO to produce nitric acid cannot be known from the disclosed content.

[0008] Based on the above-mentioned prior art, there is a need for a method that can both reduce the N2O content in adipic acid tail gas to meet industrial emission standards and fully utilize the N2O in adipic acid tail gas for resource utilization. Moreover, the method should be able to reduce the cost of tail gas treatment. SUMMARY

[0009] To solve the above-mentioned technical problems, the present application provides a method for resource utilization of N2O in adipic acid tail gas, which comprises the following steps:

[0010] (1) mixing adipic acid tail gas and air uniformly according to a certain volume ratio to obtain a mixed reaction raw gas;

[0011] (2) passing the reaction raw gas in step (1) into an oxidation furnace, and by limiting the temperature, pressure, flow rate of the reaction raw gas and reaction time of the specific oxidation furnace, a reaction product gas is obtained, which includes N2O converted into NO2, N2 and O2 in the adipic acid tail gas, wherein the conversion rate of N2O is ≥99%, and the conversion rate of N2O converted into NO2 is ≥8%;

[0012] (3) cooling the reaction product gas in step (2) and sending it into an absorption tower from the bottom of the absorption tower, and contacting and reacting with water sprayed from the top of the absorption tower in countercurrent form to generate HNO3, wherein the conversion rate of NO2 is ≥99%.

[0013] Further, the components of the adipic acid tail gas in step (1) include N2at a volume fraction of 55-60%, N2O at 30-40%, O2at 3-10%, CO2at 0-3%, H2O at 0-2%, NO at 0-0.1%, and NO2at 0-0.05%.

[0014] Further, the volume ratio of the adipic acid tail gas to air in step (1) is 1:(1-1.1), which ensures that the oxygen in the air is in excess, so that the N2O in the adipic acid tail gas is fully reacted and oxygen is provided for the conversion of NO2into nitric acid.

[0015] Further, the air in step (1) is preheated to a temperature of 450-550°C before being mixed with the adipic acid tail gas.

[0016] Further, the temperature of the oxidation furnace in step (2) is 950-1100°C, the pressure in the oxidation furnace is slightly positive, the pressure range is 1-1.02 bar, the flow rate of the reaction raw gas is (8-9)*10 -3 m 3 / h, and the reaction time is 42-64 s.

[0017] Further, the conversion rate of N2O in step (2) is ≥99%, wherein the conversion rate of N2O converted into NO2is ≥8%, and the rest is converted into N2and O2, and the involved reaction formulae include:

[0018] 2N2O=2N2+O2

[0019] 2N2O+O2=2NO2+N2.

[0020] Further, the temperature of the cooling in step (3) is 380-400°C, the flow rate of the reaction generated gas is (8.5-9.5)*10 -3 m 3 / h, the flow rate of water is (0.4-0.5)*10 -3 m 3 / h, the pressure of the absorption tower is 400-495 Mpa, the concentration of HNO3generated is 58-60 wt%, the conversion rate of NO2in the reaction generated gas is ≥99%, and the involved reaction formulae include:

[0021] 4NO2+O2+H2O=4HNO3,

[0022] wherein, the oxygen involved in the reaction comes from the oxygen in the adipic acid tail gas and the air in step (1), achieving full utilization of oxygen.

[0023] Further, the HNO3 generated in step (3) flows out from the bottom of the absorption tower and is collected, and the tail gas is discharged from the top of the absorption tower, and the content of N2O in the tail gas is ≤100 mg / m 3 , which is lower than the NO x emission limit 180 mg / m 3 in GB 31571-2015 "Petroleum Chemical Industry Pollutant Discharge Standard".

[0024] Further, the tail gas is further treated by an SCR denitration module before being discharged to generate discharge gas, the discharge gas includes N2, O2, and the purpose of the SCR denitration module is to provide an additional guarantee for the discharged tail gas, so that when the process fails, the substandard tail gas is not directly discharged to cause air pollution.

[0025] Further, the temperature of the reaction gas generated in step (2) is 950-1100 DEG C, and the reaction gas can be preheated by a heat exchanger, and the temperature of the reaction gas after heat exchange is reduced to 380-400 DEG C, and the temperature of the air preheated by the heat exchanger is increased to 450-550 DEG C, thereby saving the heat required for heating the reaction raw gas in the oxidation furnace, and achieving the purpose of recovering and utilizing heat,

[0026] The heat exchanger can shorten the reaction time in the oxidation furnace while achieving energy recovery and utilization, so that N2O is rapidly converted into NO2, N2 and O2 within 42-64 seconds, thereby achieving the effects of N2O conversion rate ≥ 99% and N2O conversion rate into NO2 ≥ 8%.

[0027] The beneficial effects of the present application are:

[0028] 1. By changing the tail gas treatment process, it is unexpectedly found that N2O in adipic acid tail gas can be treated without using a catalyst, and further, nitric acid with industrial value and nitrogen and oxygen without environmental impact can be produced, the technical solution of the present application does not need to use a catalyst, and can achieve the treatment of N2O in adipic acid tail gas and at the same time generate economic benefits, and the process is simple, the N2O removal rate is high, the stability is high, the environment is friendly, the resource utilization rate is high, and the cost of tail gas catalytic treatment can be greatly reduced.

[0029] 2. Compared with the process in the prior art which needs to use a catalyst to decompose and treat N2O and needs to be parked regularly to replace the catalyst, the method of the present application can continuously operate and continuously solve the problem of adipic acid industrial tail gas emission, so that it meets the industrial emission standard, reduces the cost of enterprises to treat tail gas, and has important practical significance and engineering application value.

[0030] 3. The heat exchanger in the method for resource utilization of N2O in adipic acid tail gas of the present invention can not only complete energy recovery and utilization, but also coordinate the limitation of various parameters in the oxidation furnace, effectively shortening the reaction time in the oxidation furnace. This allows N2O to be rapidly and stably converted into NO2, N2, and O2 within 42-64 seconds, achieving a conversion rate of N2O ≥99% and a conversion rate of N2O to NO2 ≥8%. This can accelerate the treatment of adipic acid tail gas and can be matched with upstream enterprises that produce adipic acid in large-scale continuous production. It allows enterprises to continuously and rapidly treat adipic acid tail gas in a harmless manner while producing the value-added product nitric acid, thus meeting environmental protection requirements.

[0031] 4. The heat exchanger in the method for resource utilization of N2O in adipic acid tail gas of the present invention reduces the energy consumed by the oxidation furnace by energy recovery. Without the use of a catalyst, it coordinates the various parameters in the oxidation furnace to further achieve the purpose of energy saving and resource utilization of waste gas, thus meeting my country's current requirements for "carbon neutrality" and "carbon peaking". Attached Figure Description

[0032] Figure 1 This is a flow chart of the device for resource utilization of N2O in adipic acid tail gas according to the present invention.

[0033] The numbers on the map are:

[0034] 1. Mixing tank; 2. Oxidizing furnace; 3. High-temperature gas-to-gas heat exchanger; 4. Fan; 5. Absorption tower; 6. Nitric acid collection tank; 7. SCR denitrification module; 8. Chimney; 9. Water pump; A. Adipic acid tail gas; B. Air; C. Reactant gas; D. Reactant product gas; E. Water; F. Tail gas; G. Nitric acid. Detailed Implementation

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides a method for the resource utilization of N2O in adipic acid tail gas A, the method comprising the following steps:

[0037] (1) Air B enters the high-temperature gas-to-gas heat exchanger 3 through the fan 4 and is heated to 500°C. It is then mixed evenly with adipic acid tail gas A in the mixing tank 1 at a volume ratio of 1:1 to obtain the mixed reaction raw material gas C. The temperature of the reaction raw material gas C is 250°C. Before the first air B is introduced into the mixing tank 1, the air B is not preheated and the temperature of the reaction raw material gas C is room temperature.

[0038] (2) The reactant gas C from step (1) is introduced into the oxidation furnace 2. The temperature of the oxidation furnace 2 is controlled at 1000℃, the pressure is a slight positive pressure (1.01 bar), and the flow rate of the reactant gas C is 8*10.-3 m 3 / h, and a reaction time of 52s, to obtain reaction product gas D, the temperature of the reaction product gas D is 1000℃, the reaction product gas D includes NO2, N2 and O2 converted from N2O in adipic acid tail gas A, wherein the conversion rate of N2O in the reaction product gas D is 100%, and the conversion rate of N2O to NO2 is 8.3%.

[0039] (3) The reaction product gas D from step (2) is cooled to 380°C via a high-temperature gas-to-gas heat exchanger 3 and then fed into the absorption tower 5 from the bottom. At this time, the flow rate of the reaction product gas D is 8.5*10 -3 m 3 / h, while water E flows at a velocity of 0.41*10 -3 m 3 Water is sprayed from the top of absorption tower 5 by pump 9 at a rate of / h. The generated gas D comes into countercurrent contact with the water E sprayed from the top of absorption tower 5 and reacts. The pressure in absorption tower 5 is 450 MPa, producing nitric acid (HNO3)G with a concentration of 58 wt%. Nitric acid G flows into nitric acid collection tank 6 for collection, and tail gas F is discharged from the top of absorption tower 5 with an N2O content of 0 mg / m³ at discharge. 3 NO levels are lower than those specified in GB 31571-2015 "Emission Standard of Pollutants from Petrochemical Industry". x Emission limit 180 mg / m³ 3 As required, in this embodiment, the exhaust gas F does not need to pass through the SCR denitrification module 7 for denitrification and can be directly discharged into the atmosphere through the chimney 8. The conversion rate of N2O in the reaction product gas D is 100%, and the conversion rate of N2O to NO2 is 8.3%, that is, N2O is completely decomposed.

[0040] The components of adipic acid tail gas A in step (1) include 60% N2, 30% N2O and 10% O2 by volume.

[0041] In step (1), the volume ratio of adipic acid tail gas A to air B ensures that there is excess oxygen in air B, so that the N2O in adipic acid tail gas A can react fully.

[0042] In step (2), the conversion rate of N2O is 100%, of which the conversion rate of N2O to NO2 is 8.3%, and the remainder is converted to N2 and O2. The reaction formulas involved include:

[0043] 2N₂O=2N₂+O₂

[0044] 2N₂O + O₂ = 2NO₂ + N₂.

[0045] The reaction formulas involved in step (3) include:

[0046] 4NO2+ O2+ H2O = 4HNO3,

[0047] Wherein, the oxygen involved in the reaction comes from the oxygen in the adipic acid tail gas A in step (1) and the oxygen in the air B, achieving full utilization of oxygen.

[0048] The temperature of the reaction gas D generated in step (2) is 1000℃, and the reaction gas D can be preheated by the high-temperature gas-gas heat exchanger 3 to preheat the air B. After heat exchange, the temperature of the reaction gas D is reduced to 380℃, and the temperature of the air B preheated by the heat exchanger is increased to 500℃, saving the heat required for heating the reaction raw gas C in the oxidation furnace 2, achieving the purpose of recovering and utilizing heat, while also coordinating the limitation of various parameters in the oxidation furnace 2, effectively shortening the reaction time in the oxidation furnace 2, so that N2O is quickly converted into NO2, N2 and O2 within 52s, and the conversion rate of N2O is 100%, the conversion rate of N2O converted into NO2 is 8.3%, which can speed up the treatment of adipic acid tail gas A, can match the upstream enterprises of large-scale continuous production of adipic acid, and can bring additional value products of nitric acid G to the enterprises while continuously and quickly treating the adipic acid tail gas A, meeting the environmental protection requirements.

[0049] Example 2

[0050] The present embodiment provides a method for resource utilization of N2O in adipic acid tail gas A, which comprises the following steps:

[0051] (1) The air B enters the high-temperature gas-gas heat exchanger 3 through the fan 4, and is heated to 550℃, then is mixed with the adipic acid tail gas A and the air B in the gas mixing tank 1 at a volume ratio of adipic acid tail gas A: air B = 1:1, to obtain the mixed reaction raw gas C, and the temperature of the reaction raw gas C is 275℃, wherein the air B is not preheated before being introduced into the gas mixing tank 1, and the temperature of the reaction raw gas C is room temperature;

[0052] (2) The reaction raw gas C in step (1) is introduced into the oxidation furnace 2, and the temperature of the oxidation furnace 2 is controlled at 1100℃, the pressure, flow rate and reaction time are the same as in example 1, i.e. the pressure is 1.01 bar, the flow rate of the reaction raw gas C is 8*10 -3 m 3 / h, and the reaction time is 52s, to obtain the reaction gas D, and the temperature of the reaction gas D is 1100℃, and the reaction gas D includes NO2, N2 and O2 converted from N2O in the adipic acid tail gas A, wherein the conversion rate of N2O is 100%, and the conversion rate of N2O converted into NO2 is 8.6%;

[0053] (3) The reaction gas D in step (2) is cooled by high-temperature gas-gas heat exchanger 3 to 380°C, and is sent to absorption tower 5 from the bottom of the absorption tower 5, at a flow rate of 8.5*10 -3 m 3 / h, while water E is sprayed from the top of the absorption tower 5 by water pump 9 at a flow rate of 0.41*10 -3 m 3 / h, the reaction gas D and the water E sprayed at the top of the absorption tower 5 are in countercurrent contact and react, the pressure of the absorption tower 5 is 450Mpa, and nitric acid (HNO3) G with a concentration of 58wt% is generated, the nitric acid G flows into the nitric acid collection tank 6 for collection, and tail gas F is discharged from the top of the absorption tower 5, with the content of N2O being 0mg / m 3 , which is lower than the NO x emission limit of 180mg / m 3 specified in GB 31571-2015 "Pollutant Discharge Standard for Petroleum Chemical Industry", in this embodiment, the tail gas F does not need to pass through the SCR denitration module 7 for denitration, and can be directly discharged into the atmosphere through the chimney 8, wherein the conversion rate of N2O in the reaction gas D is 100%, and the conversion rate of N2O converted into NO2 is 8.6%, that is, N2O is completely decomposed.

[0054] The components of the adipic acid tail gas A in step (1) include N2 in a volume fraction of 60%, N2O in a volume fraction of 30%, and O2 in a volume fraction of 10%.

[0055] The volume ratio of the adipic acid tail gas A and the air B in step (1) ensures that the oxygen in the air B is excessive, so that the N2O in the adipic acid tail gas A is fully reacted.

[0056] Comparative Example 1

[0057] Relative to Example 1, the present comparative example sets the conventional process conditions in the prior art, and provides a method for treating N2O in adipic acid tail gas A, which comprises the following steps:

[0058] (1) The air B enters the high-temperature gas-gas heat exchanger 3 through the fan 4, is heated to 400°C, and is uniformly mixed with the adipic acid tail gas A and the air B in a gas mixing tank 1 at a volume ratio of adipic acid tail gas A:air B of 1:1 to obtain mixed reaction raw gas C, the temperature of the reaction raw gas C is 200°C, and the air B is not preheated before being first introduced into the gas mixing tank 1;

[0059] (2) The reaction raw gas C in step (1) is introduced into the oxidation furnace 2, the temperature of the oxidation furnace 2 is controlled to be 800°C, and the pressure, flow rate and reaction time are the same as those of Example 1, that is, the pressure is 1.01bar, the flow rate of the reaction raw gas C is 8*10 -3m 3 / h, the reaction time is 52s, the reaction generated gas D is obtained, the temperature of the reaction generated gas D is 800℃, the reaction generated gas D includes NO2, N2, O2 converted from N2O in adipic acid tail gas A, and a large amount of unconverted N2O, wherein the conversion rate of N2O is only 14.7%, and the conversion rate of N2O converted into NO2 is only 0.6%;

[0060] (3) The reaction generated gas D in step (2) is cooled to 380℃ by the high-temperature gas-gas heat exchanger 3, and is sent into the absorption tower 5 from the bottom of the absorption tower 5, at this time, the flow rate of the reaction generated gas D is 8.5*10 -3 m 3 / h, and water E is sprayed from the top of the absorption tower 5 by the water pump 9 at a flow rate of 0.41*10 -3 m 3 / h, the reaction generated gas D and the water E sprayed at the top of the absorption tower 5 are in countercurrent contact and react, the pressure of the absorption tower 5 is 450Mpa, nitric acid (HNO3) G is generated, and the concentration is 3wt%, which is much lower than the concentration requirement of nitric acid G, the nitric acid G flows into the nitric acid collection tank 6 for collection, and the tail gas F is discharged from the top of the absorption tower 5, and the content of N2O when discharged is ≥490000mg / m 3 , which is much higher than the requirement of 180mg / m x of NOx emission limit value in GB 31571-2015 “Pollutant Discharge Standard for Petroleum Chemical Industry”, therefore, in the present comparative example, the tail gas F also needs to pass through the SCR denitration module 7 for denitration, and cannot be directly discharged into the atmosphere through the chimney 8. 3

[0061] The components of the adipic acid tail gas A in the step (1) include N2 with a volume fraction of 60%, N2O with a volume fraction of 30%, and O2 with a volume fraction of 10%.

[0062] Comparative Example 2

[0063] Compared with Example 1, the present comparative example sets the conventional process conditions in the prior art, and provides a method for treating N2O in adipic acid tail gas A, which comprises the following steps:

[0064] (1) The air B enters the high-temperature gas-gas heat exchanger 3 through the fan 4, is heated to 450℃, and is uniformly mixed with the adipic acid tail gas A and the air B in the gas mixing tank 1 at a volume ratio of adipic acid tail gas A: air B of 1:1, to obtain the mixed reaction raw gas C, and the temperature of the reaction raw gas C is 225℃, wherein the air B is not preheated before being first introduced into the gas mixing tank 1;

[0065] ​(2) The reaction raw gas C in step (1) is introduced into the oxidation furnace 2, and the temperature of the oxidation furnace 2 is controlled at 900℃, the pressure, flow rate and reaction time are the same as those in Example 1, i.e. the pressure is 1.01 bar, the flow rate of the reaction raw gas C is 8*10 -3 m 3 / h, and the reaction time is 52 s, to obtain a reaction product gas D, the temperature of the reaction product gas D is 900℃, the reaction product gas D includes NO2, N2, O2 converted from N2O in the adipic acid tail gas A, and a large amount of unconverted N2O, wherein the conversion rate of N2O is 72.7%, and the conversion rate of N2O to NO2 is 5.7%;

[0066] (3) The reaction product gas D in step (2) is cooled to 380℃ by the high-temperature gas-gas heat exchanger 3, and is introduced into the absorption tower 5 from the bottom of the absorption tower 5, at this time the flow rate of the reaction product gas D is 8.5*10 -3 m 3 / h, and the water E is sprayed from the top of the absorption tower 5 by the water pump 9 at a flow rate of 0.41*10 -3 m 3 / h, the reaction product gas D and the water E sprayed from the top of the absorption tower 5 are in countercurrent contact and react, the pressure of the absorption tower 5 is 450Mpa, and nitric acid (HNO3) G with a concentration of 32wt% is generated, which is far lower than the concentration requirement of the nitric acid G, the nitric acid G flows into the nitric acid collection tank 6 for collection, and the tail gas F is discharged from the top of the absorption tower 5, and the content of N2O in the tail gas F is ≥150000mg / m 3 , which is much higher than the requirement of the NO x emission limit value of 180mg / m 3 in GB 31571-2015 “Pollutant Discharge Standard for Petroleum Chemical Industry”, therefore, the tail gas F in this comparative example still needs to be subjected to the SCR denitration module 7 for denitration, and cannot be directly discharged into the atmosphere through the chimney 8.

[0067] The components of the adipic acid tail gas A in step (1) include N2 with a volume fraction of 60%, N2O with a volume fraction of 30%, and O2 with a volume fraction of 10%.

[0068] In summary, the process device of the present example can be continuously operated for a long time after being started, and there is no problem of short-term or periodic replacement of the catalyst, and by controlling the process parameters, the nitric acid with industrial value and the nitrogen and oxygen which do not affect the environment can be produced, the N2O in the adipic acid tail gas A is treated, economic benefits are obtained at the same time, the process is simple, the N2O removal rate is high, the stability is high, the process is environmentally friendly, the resource utilization rate is high, the cost of tail gas catalytic treatment can be greatly reduced, and the process has important practical significance and engineering application value.

[0069] It should be understood that the application is not limited to the arrangements and details of the flow and content already described above and illustrated in the drawings, and that various modifications and changes can be made without departing from its scope. The scope of the application is limited only by the claims that follow.

Claims

1. A method for resource utilization of N20 in adipic acid tail gas, characterized in that, The method comprises the following steps: (1) mixing adipic acid tail gas and air uniformly according to a certain volume ratio to obtain mixed reaction raw gas; (2) passing the reaction raw gas in step (1) into an oxidation furnace to obtain reaction generated gas, wherein the reaction generated gas comprises NO2 converted from N2O in the adipic acid tail gas, N2 and O2, wherein the conversion rate of N2O is ≥99%, and the conversion rate of N2O converted into NO2 is ≥8%; (3) passing the reaction generated gas in step (2) after cooling into an absorption tower from the bottom of the absorption tower, and contacting and reacting with water sprayed at the top of the absorption tower in a countercurrent manner to generate HNO3, wherein the conversion rate of NO2 is ≥99%; The temperature of the oxidation furnace in the step (2) is 950-1100 °C, the pressure in the oxidation furnace is in the range of 1-1.02 bar, the flow rate of the reaction raw material gas is (8-9) * 10 -3 m 3 / h, and the reaction time is 42-64 s. In step (2), the conversion rate of N2O is ≥99%, wherein the conversion rate of N2O converted into NO2 is ≥8%, and the rest is converted into N2 and O2, and the involved reaction formulae include: 。 2. The method of claim 1, wherein the N20 in the adipic acid off-gas is recovered. In step (1), the components of the adipic acid tail gas include N2 with a volume fraction of 55-60%, N2O with a volume fraction of 30-40%, O2 with a volume fraction of 3-10%, CO2 with a volume fraction of 0-3%, H2O with a volume fraction of 0-2%, NO with a volume fraction of 0-0.1%, and NO2 with a volume fraction of 0-0.05%.

3. The method of claim 1, wherein the N20 in the adipic acid off-gas is recovered. In step (1), the volume ratio of the adipic acid tail gas to air is 1:(1-1.1).

4. The method for resource utilization of N20 in adipic acid tail gas according to claim 3, characterized in that, In step (1), the air is preheated first, and then mixed with the adipic acid tail gas after the temperature reaches 450-550℃.

5. The method of claim 1, wherein the N20 in the adipic acid off-gas is recovered. The temperature of the step (3) is 380-400℃, the flow rate of the reaction gas is (8.5-9.5)*10 -3 m 3 / h, the flow rate of water is (0.4-0.5)*10 -3 m 3 / h, the pressure of the absorption tower is 400-495 Mpa, the concentration of HNO3 is 58-60wt%, the conversion rate of NO2 in the reaction gas is ≥ 99%, and the reaction formula involved includes: ， In the reaction, the oxygen comes from the oxygen in the adipic acid tail gas and the air in step (1).

6. The method of claim 5, wherein the N20 in the adipic acid off-gas is recovered. The HNO3 generated in the step (3) flows out from the bottom of the absorption tower and is collected, and the tail gas is discharged from the top of the absorption tower, and the content of N2O in the tail gas is ≤100 mg / m 3 .

7. The method of claim 6, wherein the N20 in the adipic acid off-gas is recovered. The tail gas is further treated by an SCR denitration module to generate discharge gas before being discharged, and the discharge gas comprises N2 and O2.

8. The method of claim 1, wherein the N20 in the adipic acid off-gas is recovered. In step (2), the temperature of the reaction generated gas is 950-1100℃, the reaction generated gas can be preheated by a heat exchanger, the temperature of the reaction generated gas after heat exchange is reduced to 380-400℃, the temperature of the air preheated by the heat exchanger is increased to 450-550℃, the heat required for heating the reaction raw gas in the oxidation furnace is saved, and the purpose of recovering and utilizing heat is achieved.

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