A method and device for recycling tail gas in adipic acid production

Abstract

The present invention relates to a method and apparatus for recycling tail gas in adipic acid production. The method comprises the following steps: 1) dilution: diluting the tail gas generated during the oxidation process for preparing adipic acid with air; 2) heating: heating the gas diluted with air in step 1) to a temperature of 100-150°C through a heat exchanger; and 3) oxidation: supplying the heated gas in step 2) as an oxidant to a cyclohexane oxidation reactor in an adipic acid production apparatus for oxidizing cyclohexane to produce a cyclohexane oxidation product. This application provides a green and environmentally friendly production process for adipic acid by reducing greenhouse gas emissions during adipic acid production.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and in particular relates to a method and device for recycling tail gas in adipic acid production. Background Art

[0002] Adipic acid is the main downstream product of benzene. According to different processes, it can be divided into two technical routes: oxidation and hydration. The oxidation method (also known as the cyclohexane method) refers to the saturated hydrogenation of benzene to produce cyclohexane, which is then oxidized to produce cyclohexanol / cyclohexanone. Cyclohexanol is further oxidized to produce cyclohexanone, which is then oxidized with concentrated nitric acid to produce adipic acid; the hydration method (also known as the cyclohexene method) refers to the selective hydrogenation of benzene to produce cyclohexene, which is then hydrated to produce cyclohexanol, which is then oxidized with hydrogen peroxide to produce cyclohexanone, and subsequently oxidized with concentrated nitric acid to produce adipic acid. Regardless of the hydration method or the oxidation method, a large amount of N2O will be generated during the oxidation process with concentrated nitric acid. Its greenhouse effect is 310 times higher than that of CO2. It is one of the three most important greenhouse gases. There is currently no emission standard, and most manufacturers directly emit it without treatment. The general composition of adipic acid tail gas is: N2O content 35-45v%, CO2 content 6-10v%, nitrogen content 45-58v%, and the rest is NO x Among them, N2O and CO2 are important greenhouse gases. How to achieve comprehensive treatment of adipic acid tail gas has always been a huge problem faced by the industry.

[0003] At present, N2O is generally treated by thermal decomposition, selective catalytic reduction, catalytic decomposition, separation and purification, etc., all of which treat it as a pollutant to make it harmless. However, N2O is also a strong oxidant. Direct decomposition and treatment will not fully tap its economic value. Summary of the Invention

[0004] The technical purpose of the present invention is to provide a method for recycling tail gas from adipic acid production. By adopting the technical solution of the present invention, the tail gas from adipic acid production can be recycled and reused, reducing greenhouse gas emissions and achieving green production of adipic acid.

[0005] Another object of the present invention is to provide an adipic acid production device, which allows the tail gas obtained in the adipic acid production process to be recycled and utilized.

[0006] Still another object of the present invention is to provide a method for producing adipic acid by using the above apparatus.

[0007] In one aspect, the present invention provides a method for recycling tail gas in adipic acid production, the method comprising the following steps:

[0008] 1) Dilution: diluting the tail gas generated during the preparation of adipic acid by oxidation with air;

[0009] 2) Heating: The gas diluted with air in step 1) is heated to a temperature of 100-150° C. through a heat exchanger;

[0010] 3) Oxidation: The gas heated in step 2) is supplied as an oxidant to a cyclohexane oxidation reactor in an adipic acid production unit for oxidizing cyclohexane to generate a cyclohexane oxidation product.

[0011] In a specific embodiment, prior to step 1), the process further includes passing tail gas generated during the oxidation process of producing adipic acid into a carbon capture device for carbon capture. Preferably, CO2 capture is performed using organic amine absorption or membrane separation, achieving a CO2 capture rate of ≥95%.

[0012] In a specific embodiment, after the carbon capture step and before the dilution step 1), the method further comprises a selective catalytic reduction reactor treatment step, that is, the gas stream after the carbon capture step is processed by a selective catalytic reduction reactor, so that the nitrogen oxides NO in the gas stream are reduced to x The content is ≤50mg / L.

[0013] In a specific embodiment, in step 1), the oxidation process for preparing adipic acid is carried out by the following steps:

[0014] 1-1) Benzene is hydrogenated to produce cyclohexane,

[0015] 1-2) oxidizing the cyclohexane obtained in step 1-1) to obtain a reaction product comprising cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide;

[0016] 1-3) introducing an alkaline solution and a catalyst solution into the reaction product of step 1-2) to decompose the cyclohexyl hydroperoxide therein into cyclohexanol and cyclohexanone;

[0017] 1-4) further dehydrogenating the cyclohexanol in the reaction product of step 1-3) to convert it into cyclohexanone;

[0018] 1-5) Oxidizing the cyclohexanone produced in step 1-4) using an oxidizing agent to obtain adipic acid.

[0019] In a specific embodiment, in step 1-1), the hydrogenation reaction is carried out at 2.0-3.0 MPa and 150-250° C. Under the aforementioned conditions, the yield of the generated cyclohexane reaches 99%.

[0020] In a specific embodiment, in step 1-3), the decomposition reaction is carried out under the following conditions: a pressure of 0.2-0.4 MPa and a temperature of 50-120° C. Preferably, during this reaction, an alkali solution is added to adjust the alkalinity of the reaction system to 1-3. Preferably, the catalyst used in this reaction is CoAc, preferably an aqueous solution of cobalt acetate at a concentration of 5-10 ppm.

[0021] In a specific embodiment, the catalyst used in steps 1-4) can be a precious metal such as Pd or Pt, or a non-precious metal such as Ni or V. The catalyst can be a homogeneous catalyst or a supported catalyst, and the carrier can be a conventional carrier such as alumina or activated carbon. The pressure can be 50-100 kPa, and the temperature can be 180-250° C. Under the aforementioned conditions, the cyclohexanol conversion rate is 70-90%.

[0022] In a specific embodiment, the method further comprises a distillation process after step 1-4) and before step 1-5), and the concentration of cyclohexanone obtained through the distillation process is ≥99%.

[0023] In a specific embodiment, in step 1-5), 50-70 wt% nitric acid is used as the oxidant, and a Cu-V-based catalyst is used as the catalyst. The reaction temperature can be 70-90°C, and the pressure can be atmospheric pressure. Under the aforementioned conditions, the yield of adipic acid is 80-95%.

[0024] In a specific embodiment, in step 3), the cyclohexane oxidation product comprises cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide, wherein the proportion of cyclohexyl hydroperoxide in the oxidation product is 50 mol%-70 mol%.

[0025] In a specific embodiment, in step 3), the gas used as the oxidant is composed of the following: CO2 < 0.2 vol%, NO x ≤50mg / L, N2O≤0.5vol%.

[0026] In a specific embodiment, in step 3), in the cyclohexane oxidation reactor, the reaction conditions are: temperature 100-150° C., pressure 0.5-1.0 MPa, and residence time 5-10 h.

[0027] In a specific embodiment, in step 3), N2O in the gas undergoes an oxidation reaction with cyclohexane and is converted into N2.

[0028] In another aspect, the present invention provides an adipic acid production device, in which N2O in the tail gas generated during the preparation of adipic acid is recovered and utilized as an oxidant, the device comprising:

[0029] The invention discloses a component for producing adipic acid, comprising at least a cyclohexane oxidation reactor and a pipeline for recovering tail gas generated in the process of preparing adipic acid to the cyclohexane oxidation reactor.

[0030] In a specific embodiment, the assembly for producing adipic acid includes the following components in sequence:

[0031] ① a benzene hydrogenation reactor, which receives benzene through a benzene supply line and oxidizes the benzene to cyclohexane;

[0032] ② A distillation reactor, which is connected to the benzene hydrogenation reactor through a pipeline and separates the materials from the benzene hydrogenation reactor into by-products and light components;

[0033] ③ A cyclohexane oxidation reactor, which is connected to the distillation reactor via a pipeline and oxidizes the light components from the distillation reactor to generate a reaction mixture containing cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide;

[0034] ④ a decomposition reactor, which is connected to the cyclohexane oxidation reactor via a pipeline and decomposes the cyclohexyl hydroperoxide in the reaction mixture from the cyclohexane oxidation reactor into cyclohexanol and cyclohexanone;

[0035] ⑤ a cyclohexanol dehydrogenation reactor, which receives the material from the decomposition reactor through a pipeline and dehydrogenates the cyclohexanol therein into cyclohexanone;

[0036] ⑥ an adipic acid production reactor, which receives the material from the cyclohexanol dehydrogenation reactor through a pipeline and oxidizes the cyclohexanone therein using nitric acid to produce adipic acid;

[0037] ⑦ A gas-liquid separator, which is connected to the adipic acid production reactor through a pipeline and separates the products generated in the adipic acid production reactor to obtain tail gas and adipic acid-rich products.

[0038] In a specific embodiment, the device further comprises, after component ⑦: ⑧ a carbon capture device, which receives the tail gas from the gas-liquid separator through a pipeline and captures CO2 in the tail gas.

[0039] In a specific embodiment, the device further comprises after component ⑧: ⑨ a selective catalytic reduction (SCR) reactor, which receives the residual gas from the carbon capture device through a pipeline and converts NO in the residual gas into x Converted into nitrogen, in this case, the tail gas is recovered from component ⑨ to ③ through pipeline.

[0040] In a specific embodiment, the assembly for producing adipic acid further comprises a heater disposed before the ① benzene hydrogenation reactor, which is used to heat the feed benzene.

[0041] In a specific embodiment, the assembly for producing adipic acid further includes a heater disposed between ① the benzene hydrogenation reactor and ② the distillation reactor.

[0042] In a specific embodiment, the device further includes a heat exchanger arranged between the ⑦ gas-liquid separator and the ③ cyclohexane oxidation reactor. When the device further includes components ⑧ and ⑨, the device includes a heat exchanger arranged between the ⑨SCR reactor and the ③ cyclohexane oxidation reactor.

[0043] In a specific embodiment, the device further comprises a dilution unit provided between the aforementioned heat exchanger and the SCR reactor, which is used to introduce air to dilute the exhaust gas after SCR treatment.

[0044] In yet another aspect, the present invention provides a method for producing adipic acid, comprising using the adipic acid production apparatus to produce adipic acid.

[0045] Beneficial effects

[0046] The method and apparatus for recycling tail gas in adipic acid production provided in the present application can utilize N2O in the tail gas generated in the adipic acid production process as an oxidant to oxidize cyclohexane to obtain cyclohexanol / cyclohexanone. On the one hand, the method and apparatus can reduce greenhouse gas emissions and have high environmental benefits. On the other hand, the method and apparatus realize the recycling and utilization of N2O and create new economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of the traditional adipic acid production process.

[0048] In the figure: B1: Heater 1, B2: Benzene hydrogenation reactor, B3: Heater 2, B4: Distillation reactor, B5: Cyclohexane oxidation reactor, B6: Decomposition reactor, B7: Cyclohexanol dehydrogenation reactor, B8: Adipic acid production reactor, B9: Gas-liquid separator

[0049] S1: Refined benzene material, S2: Heated refined benzene material, S3: Hydrogen, S4: Cyclohexane product, S5: Cyclohexane product after heat exchange, S6: Distillation by-products, S7: Light components, S8: Oxidation reaction products, S9: Alkali solution, S10: Aqueous solution of cobalt acetate catalyst, S11: Decomposition products, S12: Cyclohexanone product, S13: Nitric acid, S14: Adipic acid product, S15: Adipic acid product after tail gas removal, S16: Tail gas, S17: Air

[0050] Figure 2 The figure is a flow chart of the adipic acid production process of the present invention.

[0051] In the figure: B1: Heater 1, B2: Benzene hydrogenation reactor, B3: Heater 2, B4: Distillation reactor, B5: Cyclohexane oxidation reactor, B6: Decomposition reactor, B7: Cyclohexanol dehydrogenation reactor, B8: Adipic acid production reactor, B9: Gas-liquid separator, B10: Carbon capture device, B11: SCR reactor, B12: Heat exchanger

[0052] S1: Refined benzene material, S2: Heated refined benzene material, S3: Hydrogen, S4: Cyclohexane product, S5: Material after heat exchange, S6: Distillation by-products, S7: Light components, S8: Products after oxidation reaction, S9: Alkali solution, S10: Aqueous solution of cobalt acetate catalyst, S11: Decomposition products, S12: Cyclohexanone product, S13: Nitric acid, S14: Adipic acid product, S15: Adipic acid, S16: Tail gas, S21: Rich liquid after absorption, S18: Residual gas after CO2 capture, S19: Residual gas flow after SCR treatment, S20: Stream after heat exchange

[0053] Note: S1-S20 above also represent pipelines for transporting corresponding material flows. DETAILED DESCRIPTION

[0054] The technical solutions of the present application are illustrated below through specific embodiments to enable those skilled in the art to better understand the present application. However, these examples are not intended to limit the scope of the present application.

[0055] The core technology of this invention is to use N2O in the tail gas generated in the adipic acid production process as an oxidant to oxidize cyclohexane to obtain cyclohexanol / cyclohexanone (KA oil). The following investigates the effect of the tail gas composition (including N2O concentration) on the cyclohexane oxidation reaction. Due to the lack of industrial application, simulation tests were conducted in a 50L reactor.

[0056] In the following examples, cyclohexane conversion and selectivity were calculated as follows:

[0057] Cyclohexane conversion rate (%) = (amount of inlet cyclohexane material - amount of outlet cyclohexane material) / amount of inlet cyclohexane material

[0058] Selectivity (%) = (cyclohexanol + cyclohexanone + cyclohexyl hydroperoxide) amount of material / inlet cyclohexane amount of material

[0059] The following is a detailed description of the technical solution of the book application with reference to the accompanying drawings. Figure 2As shown, the refined benzene material S1 is heated to 150-250°C by the heater 1B1 to obtain the heated refined benzene material S2, which is supplied to the benzene hydrogenation reactor B2. Then, hydrogen S3 is introduced into the benzene hydrogenation reactor B2 for selective hydrogenation to produce cyclohexane product S4. After heat exchange in the heater 2B3, the material S5 is separated into distillation by-product S6 and light component S7 in the distillation reactor B4. The light component S7 enters the cyclohexane oxidation reactor B5. The product S8 after the oxidation reaction enters the decomposition reactor B6 to produce cyclohexanol / cyclohexanone. Alkaline solution S9 is added to the decomposition reactor. , aqueous solution of cobalt acetate catalyst S10, the decomposition product S11 enters the cyclohexanol dehydrogenation reactor B7, and is dehydrogenated into cyclohexanone product S12 under the action of the catalyst, and enters the adipic acid generation reactor B8, and generates adipic acid under the oxidation action of nitric acid S13. The adipic acid product S14 after the reaction enters the gas-liquid separator B9 and is separated into liquid adipic acid S15 and gaseous tail gas S16. The tail gas S16 enters the carbon capture device B10 to absorb and separate CO2. S21 is the rich liquid after absorption. The remaining gas S18 after CO2 capture enters the SCR reactor B11. In the SCR reactor B11, NO x The residual gas stream S19 after SCR treatment is converted into nitrogen, and is diluted with air in a dilution unit (not shown) and then heat-exchanged to about 120°C through a heat exchanger B12 to obtain a heat-exchanged stream S20. This stream is sent to the cyclohexane oxidation reactor B5 as an oxidant instead of traditional air for cyclohexane oxidation to produce KA oil, and optionally for subsequent adipic acid preparation process.

[0060] Example 1

[0061] Simulate the exhaust gas composition of industrial equipment and dilute it with air to a CO2 content of 0.14%, NO x The content was 21.8 mg / L, the N2O content was 10.0%, the reaction temperature was 130°C, the reaction pressure was 0.8 MPa, the cyclohexane conversion was 8.6%, and the selectivity of the target product was 88.9%. The N2O content in the tail gas after the reaction was 0.25%.

[0062] Example 2

[0063] Simulate the exhaust gas composition of industrial equipment and dilute it with air to a CO2 content of 0.14%, NO x The reaction temperature was 148°C, the reaction pressure was 0.6 MPa, the cyclohexane conversion was 6.6%, and the selectivity of the target product was 92.5%. The N2O content in the tail gas after the reaction was 0.12%.

[0064] Comparative Example 1

[0065] Under industrial conditions, air was used as the oxidant, the reaction temperature was 165° C., the reaction pressure was 1.3 MPa, the cyclohexane conversion was 3.6%, and the selectivity of the target product was 89.6%.

[0066] Comparative Example 2

[0067] Take the exhaust gas composition of industrial equipment, without air dilution, CO2 content is 9.4%, NO x The content was 1333 mg / L, the N2O content was 40.4%, and the remainder was nitrogen. The reaction temperature was 125°C, the reaction pressure was 0.8 MPa, the cyclohexane conversion was 10.6%, and the selectivity of the target product was 66.3%. The N2O content in the tail gas after the reaction was 3.36%.

[0068] Comparative Example 3

[0069] Take the exhaust gas from the industrial plant and dilute it with air to a CO2 content of 1200ppm, NO x The content was 13 mg / L, the N2O content was 2.4%, and the remainder was nitrogen. The reaction temperature was 148°C, the reaction pressure was 0.7 MPa, the cyclohexane conversion was 4.6%, and the selectivity for the target product was 60.3%. The N2O content in the tail gas after the reaction was 0.05%.

[0070] Comparative Example 4

[0071] Take the exhaust gas composition of the industrial device and dilute it with air to a CO2 content of 0.22%, NO x The content was 31.48 mg / L, the N2O content was 8.84%, and the remainder was nitrogen. The reaction temperature was 165°C, the reaction pressure was 1.5 MPa, the cyclohexane conversion was 16.8%, and the selectivity for the target product was 20.3%. The N2O content in the tail gas after the reaction was 0.11%.

[0072] Comparative Example 5

[0073] Take the exhaust gas composition of the industrial plant, without CO2 capture, and dilute it with air to a CO2 content of 3.45%, NO x The content was 33.5 mg / L, the N2O content was 8.6%, and the remainder was nitrogen. The reaction temperature was 105°C, the reaction pressure was 1.0 MPa, the cyclohexane conversion was 6.3%, and the selectivity for the target product was 80.3%. The N2O content in the tail gas after the reaction was 0.13%.

[0074] The various parameters of the above examples and comparative examples are summarized in Table 1 below for comparison.

[0075] Table 1

[0076]

[0077] From the data in Table 1 above, it can be seen that, as shown in Comparative Example 1, the conventional device adopts the cyclohexane air non-catalytic oxidation method, with a single-pass conversion rate of 3-5% and a selectivity of 90%. After the tail gas is diluted to a certain proportion, the N2O therein is used as an oxidant to replace air for the cyclohexane oxidation reaction. The cyclohexane conversion rate and selectivity are better than air oxidation, and the reaction temperature is low, the energy consumption is lower, and the N2O in the tail gas can be used as a resource, reducing the cost of tail gas treatment and cooperating with the carbon capture process. From Comparative Examples 2-5, it can be seen that if CO2 and NO are not treated in the tail gas recovery process, the tail gas can be oxidized to form a cyclohexane. x As well as the control of the N2O content, it will affect the conversion rate of cyclohexane and the selectivity of the target product. In comparison, Examples 1 and 2 of the present application provide a recycled gas that has been specifically treated and has a specific composition as an oxidant for cyclohexane oxidation, and thus achieve relatively satisfactory results in terms of both the conversion rate of cyclohexane and the selectivity of the target product.

[0078] In summary, the method and apparatus of the present application, on the one hand, reduce the environmental problems caused by N2O emissions during the adipic acid production process, and on the other hand, improve the efficiency of cyclohexane oxidation to produce KA oil through the recovery and utilization of N2O.

[0079] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for recycling tail gas in adipic acid production, the method comprising the following steps: 1) Dilution: Diluting the tail gas generated during the production of adipic acid by oxidation with air; 2) Heating: The gas diluted with air in step 1) is heated to 100-150° C. through a heat exchanger; 3) Oxidation: The gas heated in step 2) is supplied as an oxidant to a cyclohexane oxidation reactor in the adipic acid production unit to oxidize cyclohexane to produce a cyclohexane oxidation product. N2O in the heated gas undergoes an oxidation reaction with cyclohexane and is converted into N2. The gas used as the oxidant is composed of the following: CO2 0.14vol%, NO x 21.8 mg / L, N2O 10vol%; or CO2 0.14vol%,NO x 15.1 mg / L,N2O 8.84vol%, Wherein, in step 1), the oxidation process for preparing adipic acid is carried out by the following steps: 1-1) Benzene is hydrogenated to produce cyclohexane; 1-2) oxidizing the cyclohexane in step 1-1) to obtain a reaction product comprising cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide; 1-3) introducing an alkaline solution and a catalyst solution into the reaction product of step 1-2) to decompose the cyclohexyl hydroperoxide therein into cyclohexanol and cyclohexanone; 1-4) further dehydrogenating the cyclohexanol in the reaction product of step 1-3) to convert it into cyclohexanone; 1-5) Oxidizing the cyclohexanone produced in step 1-4) using an oxidizing agent to obtain adipic acid.

2. The method according to claim 1, wherein Before step 1), the method further includes the step of passing the tail gas generated in the process of preparing adipic acid by oxidation into a carbon capture device for carbon capture.

3. The method according to claim 2, wherein: Use organic amine absorption or membrane separation to capture CO2, so that the CO2 capture rate is ≥95%.

4. The method according to claim 2 or 3, wherein: After the carbon capture step and before the dilution step 1), the method further comprises subjecting the gas stream after the carbon capture step to a selective catalytic reduction reactor, so that the nitrogen oxides NO in the gas stream are reduced to x The content is ≤50mg / L.

5. The method according to claim 1, wherein In step 1-1), the hydrogenation reaction is carried out at 2.0-3.0 MPa and 150-250°C. In step 1-3), the reaction conditions of the decomposition reaction are: pressure 0.2-0.4 MPa, temperature 50-120°C, adding alkali solution to adjust the alkalinity of the reaction system to 1-3, and the catalyst is 5-10 ppm of cobalt acetate aqueous solution. In step 1-4), the catalyst used is a supported catalyst, the active component of which is selected from Pd, Pt, Ni, V, and the carrier of the catalyst is alumina or activated carbon; the pressure is 50-100 kPa, the temperature is 180-250 ° C, The method further comprises a distillation process after step 1-4) and before step 1-5), wherein the concentration of cyclohexanone obtained through the distillation process is ≥99%. In step 1-5), 50-70 wt% nitric acid is used as an oxidant, a Cu-V based catalyst is used as a catalyst, the reaction temperature is 70-90° C., and the pressure is normal pressure.

6. The method according to claim 1, wherein In step 3), the cyclohexane oxidation product comprises cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide, wherein the proportion of cyclohexyl hydroperoxide in the oxidation product is 50 mol%-70 mol%.

7. The method according to claim 1, wherein In step 3), the reaction conditions are: temperature 100-150° C., pressure 0.5-1.0 MPa, and residence time 5-10 h.

8. An adipic acid production device for implementing the tail gas recycling method in adipic acid production according to any one of claims 1 to 7, wherein N2O in the tail gas generated during adipic acid production is recycled as an oxidant, the device comprising the following components: An assembly for producing adipic acid comprising a cyclohexane oxidation reactor; and The tail gas generated during the preparation of adipic acid is recovered to the pipeline of the cyclohexane oxidation reactor, in, The assembly for producing adipic acid includes the following components in sequence: (1) a benzene hydrogenation reactor that receives benzene via a benzene supply line and oxidizes the benzene to cyclohexane; (2) a distillation reactor connected to the benzene hydrogenation reactor via a pipeline and separating the material from the benzene hydrogenation reactor into by-products and light components; (3) a cyclohexane oxidation reactor connected to the distillation reactor via a pipeline and oxidizing light components from the distillation reactor to generate a reaction mixture containing cyclohexanol, cyclohexanone, and cyclohexyl hydroperoxide; (4) a decomposition reactor connected to the cyclohexane oxidation reactor via a pipeline and decomposing cyclohexyl hydroperoxide in the reaction mixture from the cyclohexane oxidation reactor into cyclohexanol and cyclohexanone; (5) a cyclohexanol dehydrogenation reactor, which receives the material from the decomposition reactor through a pipeline and dehydrogenates the cyclohexanol therein into cyclohexanone; (6) an adipic acid production reactor, which receives the material from the cyclohexanol dehydrogenation reactor through a pipeline and oxidizes the cyclohexanone therein using nitric acid to produce adipic acid; (7) A gas-liquid separator, which is connected to the adipic acid production reactor via a pipeline and separates the products generated in the adipic acid production reactor to obtain tail gas and adipic acid-rich products.

9. The device according to claim 8, wherein The device further comprises: (8) a carbon capture device, which receives the tail gas from the gas-liquid separator through a pipeline and captures CO2 in the tail gas; (9) a selective catalytic reduction reactor, which receives residual gas from the carbon capture device through a pipeline and converts NOx in the residual gas into nitrogen; a heat exchanger disposed between the (9) selective catalytic reduction reactor and the (3) cyclohexane oxidation reactor; and The dilution unit is arranged between the aforementioned heat exchanger and the (9) selective catalytic reduction reactor, and is used to introduce air to dilute the exhaust gas treated by the selective catalytic reduction reactor. 10 . A method for producing adipic acid, comprising producing adipic acid using the adipic acid production apparatus according to claim 8 or 9 .

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