A deoxygenation device and deoxygenation purification process for polluted nitrogen in an air separation device

Abstract

The invention relates to a deoxygenation device for polluted nitrogen in an air separation device and a deoxygenation purification process; the device comprises a polluted nitrogen compressor connected to the air separation device, the polluted nitrogen compressor is connected to a nitrogen storage tank through a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee is arranged between the polluted nitrogen compressor and the pre-deoxygenation unit, the first tee is connected to a hydrogen supply device through a first hydrogen supplementary pipeline; the device has the advantages of small investment and land occupation, short construction period, large nitrogen output and high product purity, can effectively improve the utilization rate of nitrogen to meet the shortage of nitrogen products in air separation devices caused by the development of the park, can also meet the purification treatment of polluted nitrogen with an oxygen content of no more than 3%, and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] The present invention relates to the technical field of contaminated nitrogen gas purification, and in particular to a deoxygenation device for contaminated nitrogen gas in an air separation device and a deoxygenation purification process. Background Art

[0002] Air separation units are widely used in traditional metallurgy, coal chemical industry, petrochemical industry, nitrogen fertilizer industry, professional gas companies and other fields. The products of air separation units include oxygen, nitrogen, argon, etc. Among them, nitrogen products are often used as synthetic raw materials, purging nitrogen, replacing nitrogen, protecting nitrogen, etc., and are a typical public engineering gas. The nitrogen products produced by an air separation unit formed in a park are often constant, and with the development of the park, the demand for nitrogen products from other units will increase, resulting in a shortage of nitrogen products in the air separation unit. There are many methods for producing nitrogen products, such as: cryogenic air separation unit, PSA nitrogen generator, membrane nitrogen generation, etc. Among them, air separation units have advantages in large-scale production, and can also obtain oxygen, argon, etc., but the investment, construction period, and floor space are relatively large, which is not suitable for situations where new nitrogen products are needed alone; PSA nitrogen generators are relatively economical in investment and occupy a small area, but the scale is small. For example, the nitrogen production of a single nitrogen generator is often less than 3000Nm 3 / h; Membrane nitrogen production is rarely used and is limited by the quality of membrane separation components, and the purity of nitrogen cannot be guaranteed. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method based on an existing air separation unit, which can effectively remove oxygen from the contaminated nitrogen by mixing hydrogen with the contaminated nitrogen. The method has the advantages of small investment and land occupation, short construction period, large nitrogen output and high product purity. The deoxygenation device and deoxygenation purification process for contaminated nitrogen in the air separation unit can effectively solve the problem of shortage of nitrogen products in the air separation unit caused by the development of the industrial park.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A deoxygenation device for contaminated nitrogen in an air separation device comprises a contaminated nitrogen compressor connected to the air separation device, wherein the contaminated nitrogen compressor is connected to a nitrogen storage tank via a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee is provided between the contaminated nitrogen compressor and the pre-deoxygenation unit, and the first tee is connected to a hydrogen supply device via a first hydrogen supplementation pipeline.

[0006] Preferably, the pre-deoxygenation unit comprises a shortcut pipeline with a shortcut valve and a combustion deoxidizer connected in series with the shortcut pipeline.

[0007] Preferably, the pre-deoxygenation unit further comprises a steam heater which is arranged between the first tee and the combustion deaerator and is connected in parallel with the shortcut pipeline.

[0008] Preferably, a connecting pipe with an eleventh valve is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, a second tee and a third tee are respectively provided at both ends of the connecting pipe, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee and the third end of the third tee.

[0009] Preferably, the series-parallel deep deoxygenation unit includes a pre-reactor cooler connected to the third end of the second tee, and the outlet end of the pre-reactor cooler is connected to the third end of the third tee through a first combustion deoxygenator and a second combustion deoxygenator connected in parallel.

[0010] Preferably, the heating pre-deoxygenation unit and the second tee are connected to a hydrogen supply device via a second hydrogen supplement pipeline.

[0011] Preferably, a fourth tee is provided at the outlet end of the first combustion deaerator, and a fifth tee is provided at the inlet end of the second combustion deaerator; the third end of the fourth tee is connected to the third end of the fifth tee through the first valve, the series cooler, the sixth tee and the second valve; the third end of the sixth tee is connected to the hydrogen supply device through the third hydrogen replenishment pipeline.

[0012] Preferably, a third valve and a fourth valve are respectively provided between the outlet end of the pre-reactor cooler and the first combustion deoxidizer and the second combustion deoxidizer; a fifth valve and a sixth valve are respectively provided between the first combustion deoxidizer and the second combustion deoxidizer and the third end of the third tee; a seventh valve, an eighth valve and a ninth valve are respectively provided on the first hydrogen replenishment pipeline, the second hydrogen replenishment pipeline and the third hydrogen replenishment pipeline.

[0013] Preferably, the nitrogen dehydration separation unit comprises a reactor condenser, the reactor condenser is connected to the water separation inlet, the gas phase outlet of the water separator is connected to the nitrogen storage tank through a drying device; the liquid phase outlet of the water separator is connected to the water storage tank through a tenth valve.

[0014] A deoxygenation purification process using a deoxygenation device for contaminated nitrogen in an air separation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0015] The oxygen content in the contaminated nitrogen gas in the low oxygen content contaminated nitrogen gas purification method is: X, 0.2≤X≤1%, the oxygen content in the contaminated nitrogen gas in the medium oxygen content contaminated nitrogen gas purification method is: Y, 1<Y≤2%, and the oxygen content in the contaminated nitrogen gas in the high oxygen content contaminated nitrogen gas purification method is: Z, 2<Z≤3%;

[0016] 1. The method for purifying low oxygen content contaminated nitrogen includes the following steps:

[0017] Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of X, a pressure of 5 KPa, and a temperature of room temperature. The contaminated nitrogen gas is pressurized to 3.0 MPa by a contaminated nitrogen compressor, and the temperature is raised, and the gas is mixed with hydrogen from outside the boundary.

[0018] Step 2: The hydrogen flow is controlled by the seventh valve to a constant flow, and the mixed gas enters the combustion deaerator through the steam heater or the shortcut pipeline;

[0019] Step 3: All oxygen is consumed by the reaction in the combustion deaerator; the temperature of the polluted nitrogen gas passing through the combustion deaerator is 310°C and the oxygen content is ≤10ppm;

[0020] Step 4: The nitrogen gas deoxygenated by the combustion deaerator enters the reactor condenser through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40° C.;

[0021] Step 5: The cooled material after the reactor condenser is passed through a water separator to separate the reaction water, and the separated gas enters a drying device to dry and remove the saturated water in the other materials to produce qualified nitrogen;

[0022] Step 6: The reaction water separated by the water separator enters the water storage tank through the tenth valve;

[0023] When the dirty nitrogen gas passing through the dirty nitrogen compressor in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator after being heated to not less than 100°C by a steam heater;

[0024] The ratio of the hydrogen flow rate passing through the seventh valve in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500;

[0025] 2. The method for purifying polluted nitrogen gas with medium oxygen content comprises the following steps:

[0026] Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of Y, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 2.0 MPa by a contaminated nitrogen compressor, and then the temperature is raised and mixed with hydrogen from outside the boundary;

[0027] Step 2: The hydrogen flow is controlled by the seventh valve to a constant flow, and the mixed gas enters the combustion deaerator through the steam heater or the shortcut pipeline;

[0028] Step 3: A quarter of the oxygen in the polluted nitrogen is consumed in the combustion deaerator, and the temperature of the polluted nitrogen passing through the combustion deaerator (3) is 200°C;

[0029] Step 4: The dirty nitrogen gas after the combustion deaerator reaction is mixed with the hydrogen from the eighth valve and enters the pre-reactor cooler, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0030] Step 5: The cooled contaminated nitrogen gas passes through the first combustion deaerator and the second combustion deaerator respectively, and the remaining oxygen is reacted in the first combustion deaerator and the second combustion deaerator respectively. The temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0031] Step 6: The nitrogen after passing through the first combustion deaerator and the second combustion deaerator enters the reactor condenser, and the temperature is reduced to 40°C;

[0032] Step 7: The cooled material after the reactor condenser is passed through a water separator to separate the reaction water, and the separated gas enters a drying device to dry and remove the saturated water in the other gas to produce qualified nitrogen;

[0033] Step 8: The reaction water separated by the water separator enters the water storage tank through the tenth valve;

[0034] When the dirty nitrogen gas passing through the dirty nitrogen compressor in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator after being heated to not less than 100°C by a steam heater;

[0035] The ratio of the hydrogen flow rate passing through the seventh valve in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:1000;

[0036] The ratio of the hydrogen flow rate passing through the eighth valve in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 34-35:1000;

[0037] 3. The method for purifying polluted nitrogen with high oxygen content comprises the following steps:

[0038] Step 1: The contaminated nitrogen from the air separation unit has an oxygen content of Z, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen is pressurized to 0.5 MPa by a contaminated nitrogen compressor, and the temperature is raised, and the gas is mixed with hydrogen from outside the air separation unit.

[0039] Step 2: The hydrogen flow is controlled by the seventh valve to a constant flow, and the mixed gas enters the combustion deaerator through the steam heater or the shortcut pipeline;

[0040] Step 3: One sixth of the total oxygen content in the polluted nitrogen is consumed in the combustion deaerator, and the temperature of the polluted nitrogen passing through the combustion deaerator is 180°C;

[0041] Step 4: The dirty nitrogen gas after the combustion deaerator reaction is mixed with the hydrogen from the second hydrogen supply pipeline and the eighth valve, and enters the pre-reactor cooler, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0042] Step 5: The polluted nitrogen gas after cooling in step 4 enters the first combustion deaerator through the third valve for catalytic combustion deoxidation, consuming one third of the total oxygen content in the polluted nitrogen gas; the temperature of the polluted nitrogen gas after passing through the first combustion deaerator is 200°C;

[0043] Step 6: The dirty nitrogen after passing through the first combustion deaerator passes through the first valve and the series cooler in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline. After mixing, it enters the second combustion deaerator through the second valve and the fifth three-way, and is deoxidized by catalytic combustion to consume all the oxygen in the dirty nitrogen. The nitrogen temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0044] Step 7: The nitrogen passing through the second combustion deaerator enters the reactor condenser and the temperature is reduced to 40°C;

[0045] Step 8: The cooled material after the reactor condenser is passed through a water separator to separate the reaction water, and the separated gas enters a drying device to dry and remove the saturated water in the other materials to produce qualified nitrogen;

[0046] Step 9: The reaction water separated by the water separator enters the water storage tank through the tenth valve;

[0047] When the dirty nitrogen gas passing through the dirty nitrogen compressor in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator after being heated to not less than 100°C by a steam heater;

[0048] The ratio of the hydrogen flow rate passing through the seventh valve in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 5-6:500;

[0049] The ratio of the hydrogen flow rate passing through the eighth valve in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500;

[0050] The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 33-35:1000.

[0051] According to the above scheme, a deoxygenation device and deoxygenation purification process for polluted nitrogen in an air separation device are prepared. By setting a hydrogen supplementary pipeline to mix with the polluted nitrogen, oxygen in the polluted nitrogen can be removed in the combustion deoxygenator, so as to achieve the purpose of purifying the polluted nitrogen; further, by setting a series-parallel deep deoxygenation unit and cooperating with a basic pre-deoxygenation unit, the process line can be adjusted in time according to the different oxygen contents in the polluted nitrogen in the actual process to achieve the purpose of meeting polluted nitrogen with different oxygen contents, and effectively ensure the purity of nitrogen in the product gas. It has the advantages of small investment and land occupation, short construction period, large nitrogen output and high product purity. It can not only effectively improve the utilization rate of nitrogen to meet the shortage of nitrogen products in the air separation device caused by the development of the park, but also can meet the purification treatment of polluted nitrogen with an oxygen content of no more than 3%, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0054] See also Figure 1 :The present invention is a deoxygenation device and deoxygenation purification process for contaminated nitrogen in an air separation device, wherein the device comprises a contaminated nitrogen compressor 1 connected to the air separation device, wherein the contaminated nitrogen compressor 1 is connected to a nitrogen storage tank 22 via a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee 28 is provided between the contaminated nitrogen compressor 1 and the pre-deoxygenation unit, and the first tee 28 is connected to a hydrogen supply device 23 via a first hydrogen replenishment pipeline 24. In the present invention, the contaminated nitrogen is compressed, hydrogen is added after compression, and oxygen in the contaminated nitrogen is consumed and removed through a pre-deoxygenation unit to achieve the purpose of purifying the contaminated nitrogen; subsequently, the deoxygenated nitrogen is dehydrated and separated to recover the nitrogen. The hydrogen supply device 23 described in the present invention can be a hydrogen storage tank, a hydrogen production device, a hydrogen pipeline network, and the like.

[0055] Furthermore, the pre-deoxygenation unit includes a shortcut pipeline with a shortcut valve 34 and a combustion deoxidizer 3 connected in series with the shortcut pipeline. The pre-deoxygenation unit also includes a steam heater 2 arranged between the first tee 28 and the combustion deoxidizer 3 and connected in parallel with the shortcut pipeline. The connection relationship between the steam heater 2 and the shortcut pipeline described in the present invention is parallel, that is, after the hydrogen is supplemented, the dirty nitrogen gas can be heated or not. The key to whether the dirty nitrogen gas is heated is whether the temperature of the dirty nitrogen gas can reach 100°C when entering the combustion deoxidizer 3. When the temperature entering the combustion deoxidizer 3 reaches 100°C, the dirty nitrogen gas can directly enter the combustion deoxidizer 3 from the shortcut pipeline. When the temperature entering the combustion deoxidizer 3 is lower than 100°C, the dirty nitrogen gas enters the combustion deoxidizer 3 after being heated by the steam heater 2.

[0056] Furthermore, a connecting pipe with an eleventh valve 21 is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, a second tee 29 and a third tee 30 are provided at both ends of the connecting pipe, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee 29 and the third end of the third tee 30. The present invention can adapt to the purification treatment of polluted nitrogen with an oxygen content not greater than 3%. When the oxygen content in the polluted nitrogen is not greater than 1%, the nitrogen passing through the combustion deaerator 3 can directly enter the nitrogen dehydration separation unit; when the oxygen content in the polluted nitrogen is greater than 1% and not greater than 3%, the polluted nitrogen needs to be deeply deoxygenated by hydrogenation through a series-parallel deep deoxygenation unit after passing through the combustion deaerator 3.

[0057] Furthermore, the series-parallel deep deoxygenation unit includes a pre-reactor cooler 4 connected to the third end of the second tee 29, and the outlet end of the pre-reactor cooler 4 is connected to the third end of the third tee 30 through the first combustion deoxygenator 5 and the second combustion deoxygenator 6 connected in parallel.

[0058] Furthermore, the heating pre-deoxygenation unit and the second three-way 29 are connected to the hydrogen supply device 23 through the second hydrogen supplementary pipeline 25. When the oxygen content in the contaminated nitrogen is greater than 1% and not greater than 2%, the contaminated nitrogen needs to pass through the pre-reactor cooler 4 and the first combustion deoxygenator 5 and the second combustion deoxygenator 6 connected in parallel after passing through the combustion deoxygenator 3, so as to achieve the purpose of deep deoxygenation of the contaminated nitrogen and increase the processing capacity of the contaminated nitrogen; when the contaminated nitrogen enters the first combustion deoxygenator 5 or the second combustion deoxygenator 6, hydrogen is added through the second hydrogen supplementary pipeline 25.

[0059] Furthermore, the outlet end of the first combustion deoxidizer 5 is provided with a fourth tee 31, and the inlet end of the second combustion deoxidizer 6 is provided with a fifth tee 32. The third end of the fourth tee 31 is connected to the third end of the fifth tee 32 through the first valve 14, the series cooler 16, the sixth tee 33 and the second valve 15; the third end of the sixth tee 33 is connected to the hydrogen supply device 23 through the third hydrogen replenishing pipeline 26. When the oxygen content in the contaminated nitrogen is greater than 3% and not greater than 3%, the contaminated nitrogen needs to pass through the pre-reactor cooler 4 and then pass through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 in sequence after passing through the combustion deoxidizer 3, so as to achieve the purpose of deeper deoxygenation of the contaminated nitrogen; the above-mentioned contaminated nitrogen is hydrogenated by the second hydrogen replenishing pipeline 25 before entering the first combustion deoxidizer 5, and hydrogenated by the third hydrogen replenishing pipeline 26 before entering the second combustion deoxidizer 6. The outlet end of the pre-reactor cooler 4 and the first combustion deoxidizer 5 and the second combustion deoxidizer 5 are respectively provided with a third valve 10 and a fourth valve 11; the first combustion deoxidizer 5 and the second combustion deoxidizer 6 and the third end of the third three-way 30 are respectively provided with a fifth valve 12 and a sixth valve 13. The first hydrogen supplementary pipeline 24, the second hydrogen supplementary pipeline 25 and the third hydrogen supplementary pipeline 26 are respectively provided with a seventh valve 17, an eighth valve 18 and a ninth valve 19. The above arrangement can achieve the purpose of easy control and easy hydrogen distribution.

[0060] Furthermore, the nitrogen dehydration separation unit comprises a reactor condenser 7, the reactor condenser 7 is connected to the inlet of the water separator 8, the gas phase outlet of the water separator 8 is connected to the nitrogen storage tank 22 through the drying device 9; the liquid phase outlet of the water separator 8 is connected to the water storage tank 27 through the tenth valve 20. The present invention realizes cooling of the reactor condenser 7, and separates the water vapor by the water separator 8, and removes the water carried in the nitrogen by the drying device 9 after separation.

[0061] A deoxygenation purification process for contaminated nitrogen in an air separation device using a deoxygenation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0062] The oxygen content in the contaminated nitrogen gas in the low oxygen content contaminated nitrogen gas purification method is: X, 0.2≤X≤1%, the oxygen content in the contaminated nitrogen gas in the medium oxygen content contaminated nitrogen gas purification method is: Y, 1<Y≤2%, and the oxygen content in the contaminated nitrogen gas in the high oxygen content contaminated nitrogen gas purification method is: Z, 2<Z≤3%;

[0063] 1. The method for purifying low oxygen content contaminated nitrogen includes the following steps:

[0064] Step 1: The polluted nitrogen gas from the air separation device has an oxygen content of X, a pressure of 5 KPa, and a temperature of room temperature. The polluted nitrogen gas is pressurized to 3.0 MPa by the polluted nitrogen compressor 1, and the temperature rises, and is mixed with hydrogen from outside the boundary;

[0065] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0066] Step 3: All oxygen is consumed by the reaction in the combustion deaerator 3; the temperature of the polluted nitrogen gas passing through the combustion deaerator 3 is 310°C, and the oxygen content is ≤10ppm;

[0067] Step 4: The nitrogen gas deoxygenated by the combustion deaerator 3 enters the reactor condenser 7 through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40° C.;

[0068] Step 5: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the other gas to produce qualified nitrogen;

[0069] Step 6: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0070] When the dirty nitrogen gas passing through the dirty nitrogen compressor 1 in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor 1 rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 after being heated to not less than 100°C by the steam heater 2;

[0071] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500;

[0072] 2. The method for purifying polluted nitrogen gas with medium oxygen content comprises the following steps:

[0073] Step 1: The contaminated nitrogen gas from the air separation device has an oxygen content of Y, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 2.0 MPa by the contaminated nitrogen compressor 1, and then the temperature is raised and mixed with hydrogen from outside the boundary;

[0074] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0075] Step 3: A quarter of the oxygen in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 200°C;

[0076] Step 4: the polluted nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the eighth valve 18 and enters the pre-reactor cooler 4, and the temperature of the polluted nitrogen gas after cooling is reduced to 40°C;

[0077] Step 5: The cooled contaminated nitrogen gas passes through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively, and the remaining oxygen is reacted in the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively. The temperature after the reaction is 280° C. and the oxygen content is ≤10ppm;

[0078] Step 6: The nitrogen after passing through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 enters the reactor condenser 7, and the temperature is reduced to 40° C.;

[0079] Step 7: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0080] Step 8: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0081] When the dirty nitrogen gas passing through the dirty nitrogen compressor 1 in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor 1 rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 after being heated to not less than 100°C by the steam heater 2;

[0082] The ratio of the hydrogen flow rate passing through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:1000;

[0083] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 34-35:1000;

[0084] 3. The method for purifying polluted nitrogen with high oxygen content comprises the following steps:

[0085] Step 1: The contaminated nitrogen gas from the air separation device has an oxygen content of Z, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 0.5 MPa by the contaminated nitrogen compressor 1, and the temperature is raised, and the gas is mixed with hydrogen from outside the boundary.

[0086] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0087] Step 3: One sixth of the total oxygen content in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 180°C;

[0088] Step 4: the dirty nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the second hydrogen supply pipeline 25 and the eighth valve 18, and enters the pre-reactor cooler 4, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0089] Step 5: The contaminated nitrogen gas after cooling in step 4 enters the first combustion deaerator 5 through the third valve 10 for catalytic combustion deoxidation, consuming one third of the total oxygen content in the contaminated nitrogen gas; the temperature of the contaminated nitrogen gas after passing through the first combustion deaerator 5 is 200°C;

[0090] Step 6: The contaminated nitrogen after passing through the first combustion deaerator 5 passes through the first valve 14 and the series cooler 16 in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline 26. After mixing, it passes through the second valve 15 and the fifth three-way 32 to enter the second combustion deaerator 6, and is deoxidized by catalytic combustion to consume all oxygen in the contaminated nitrogen. The nitrogen temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0091] Step 7: The nitrogen passing through the second combustion deaerator 6 enters the reactor condenser 7, and the temperature is reduced to 40°C;

[0092] Step 8: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0093] Step 9: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0094] When the dirty nitrogen gas passing through the dirty nitrogen compressor 1 in the above step 1 rises to not less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; when the dirty nitrogen gas passing through the dirty nitrogen compressor 1 rises to less than 100°C, the mixed gas in step 2 enters the combustion deaerator 3 after being heated to not less than 100°C by the steam heater 2;

[0095] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 5-6:500;

[0096] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500;

[0097] The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline 26 in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 33-35:1000.

[0098] In order to explain the present invention in more detail, the present invention is further described in conjunction with embodiments. Specific embodiments are as follows:

[0099] Example 1

[0100] A deoxygenation device for contaminated nitrogen in an air separation device comprises a contaminated nitrogen compressor 1 connected to the air separation device, wherein the contaminated nitrogen compressor 1 is connected to a nitrogen storage tank 22 through a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee 28 is provided between the contaminated nitrogen compressor 1 and the pre-deoxygenation unit, and the first tee 28 is connected to a hydrogen supply device 23 through a first hydrogen supplementation pipeline 24. The pre-deoxygenation unit comprises a shortcut pipeline with a shortcut valve 34 and a combustion deoxygenator 3 connected in series with the shortcut pipeline. The pre-deoxygenation unit also comprises a steam heater 2 arranged between the first tee 28 and the combustion deoxygenator 3 and connected in parallel with the shortcut pipeline. A connecting pipeline with an eleventh valve 21 is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, and a second tee 29 and a third tee 30 are provided at both ends of the connecting pipeline, respectively, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee 29 and the third end of the third tee 30. The series-parallel deep deoxygenation unit includes a pre-reactor cooler 4 connected to the third end of the second tee 29, and the outlet end of the pre-reactor cooler 4 is connected to the third end of the third tee 30 through the first combustion deoxygenator 5 and the second combustion deoxygenator 6 connected in parallel. The heating pre-deoxygenation unit and the second tee 29 are connected to the hydrogen supply device 23 through the second hydrogen supplementary pipeline 25. The outlet end of the first combustion deoxygenator 5 is provided with a fourth tee 31, and the inlet end of the second combustion deoxygenator 6 is provided with a fifth tee 32. The third end of the fourth tee 31 is connected to the third end of the fifth tee 32 through the first valve 14, the series cooler 16, the sixth tee 33 and the second valve 15; the third end of the sixth tee 33 is connected to the hydrogen supply device 23 through the third hydrogen supplementary pipeline 26. The outlet end of the pre-reactor cooler 4 and the first combustion deoxidizer 5 and the second combustion deoxidizer 5 are respectively provided with a third valve 10 and a fourth valve 11; the first combustion deoxidizer 5 and the second combustion deoxidizer 6 and the third end of the third three-way 30 are respectively provided with a fifth valve 12 and a sixth valve 13. The first hydrogen replenishing pipeline 24, the second hydrogen replenishing pipeline 25 and the third hydrogen replenishing pipeline 26 are respectively provided with a seventh valve 17, an eighth valve 18 and a ninth valve 19. The nitrogen dehydration separation unit comprises a reactor condenser 7, the reactor condenser 7 is connected to the inlet of the water separator 8, and the gas phase outlet of the water separator 8 is connected to the nitrogen storage tank 22 through the drying device 9; the liquid phase outlet of the water separator 8 is connected to the water storage tank 27 through the tenth valve 20.

[0101] A deoxygenation purification process for polluted nitrogen in an air separation device using a deoxygenation device, characterized in that the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the polluted nitrogen in the air separation device, and the low-oxygen content polluted nitrogen purification method comprises the following steps:

[0102] Step 1: The contaminated nitrogen gas from the air separation device has an oxygen content of 0.2%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 3.0 MPa by the contaminated nitrogen compressor 1, and the temperature is raised to 120°C, and then mixed with hydrogen from outside the boundary;

[0103] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0104] Step 3: All oxygen is consumed by the reaction in the combustion deaerator 3; the temperature of the polluted nitrogen gas passing through the combustion deaerator 3 is 310°C, and the oxygen content is ≤10ppm;

[0105] Step 4: The nitrogen gas deoxygenated by the combustion deaerator 3 enters the reactor condenser 7 through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40° C.;

[0106] Step 5: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the other gas to produce qualified nitrogen;

[0107] Step 6: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0108] The mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; the ratio of the hydrogen flow through the seventh valve 17 in step 2 to the dirty nitrogen flow from the air separation device in step 1 is 11:500.

[0109] Example 2

[0110] A deoxygenation device for contaminated nitrogen in an air separation device comprises a contaminated nitrogen compressor 1 connected to the air separation device, wherein the contaminated nitrogen compressor 1 is connected to a nitrogen storage tank 22 through a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee 28 is provided between the contaminated nitrogen compressor 1 and the pre-deoxygenation unit, and the first tee 28 is connected to a hydrogen supply device 23 through a first hydrogen supplementation pipeline 24. The pre-deoxygenation unit comprises a shortcut pipeline with a shortcut valve 34 and a combustion deoxygenator 3 connected in series with the shortcut pipeline. The pre-deoxygenation unit also comprises a steam heater 2 arranged between the first tee 28 and the combustion deoxygenator 3 and connected in parallel with the shortcut pipeline. A connecting pipeline with an eleventh valve 21 is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, and a second tee 29 and a third tee 30 are provided at both ends of the connecting pipeline, respectively, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee 29 and the third end of the third tee 30. The series-parallel deep deoxygenation unit includes a pre-reactor cooler 4 connected to the third end of the second tee 29, and the outlet end of the pre-reactor cooler 4 is connected to the third end of the third tee 30 through the first combustion deoxygenator 5 and the second combustion deoxygenator 6 connected in parallel. The heating pre-deoxygenation unit and the second tee 29 are connected to the hydrogen supply device 23 through the second hydrogen supplementary pipeline 25. The outlet end of the first combustion deoxygenator 5 is provided with a fourth tee 31, and the inlet end of the second combustion deoxygenator 6 is provided with a fifth tee 32. The third end of the fourth tee 31 is connected to the third end of the fifth tee 32 through the first valve 14, the series cooler 16, the sixth tee 33 and the second valve 15; the third end of the sixth tee 33 is connected to the hydrogen supply device 23 through the third hydrogen supplementary pipeline 26. The outlet end of the pre-reactor cooler 4 and the first combustion deoxidizer 5 and the second combustion deoxidizer 5 are respectively provided with a third valve 10 and a fourth valve 11; the first combustion deoxidizer 5 and the second combustion deoxidizer 6 and the third end of the third three-way 30 are respectively provided with a fifth valve 12 and a sixth valve 13. The first hydrogen replenishing pipeline 24, the second hydrogen replenishing pipeline 25 and the third hydrogen replenishing pipeline 26 are respectively provided with a seventh valve 17, an eighth valve 18 and a ninth valve 19. The nitrogen dehydration separation unit comprises a reactor condenser 7, the reactor condenser 7 is connected to the inlet of the water separator 8, and the gas phase outlet of the water separator 8 is connected to the nitrogen storage tank 22 through the drying device 9; the liquid phase outlet of the water separator 8 is connected to the water storage tank 27 through the tenth valve 20.

[0111] A deoxygenation purification process for polluted nitrogen in an air separation device using a deoxygenation device, characterized in that the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the polluted nitrogen in the air separation device, and the low-oxygen content polluted nitrogen purification method comprises the following steps:

[0112] Step 1: The contaminated nitrogen gas from the air separation device has an oxygen content of 1%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 3.0 MPa at normal temperature and pressure by the contaminated nitrogen compressor 1, and the temperature is raised to 150° C. and mixed with hydrogen from outside the boundary;

[0113] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0114] Step 3: All oxygen is consumed by the reaction in the combustion deaerator 3; the temperature of the polluted nitrogen gas passing through the combustion deaerator 3 is 310°C, and the oxygen content is ≤10ppm;

[0115] Step 4: The nitrogen gas deoxygenated by the combustion deaerator 3 enters the reactor condenser 7 through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40° C.;

[0116] Step 5: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the other gas to produce qualified nitrogen;

[0117] Step 6: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0118] The mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline;

[0119] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 12:500.

[0120] Example 3

[0121] A deoxygenation device for contaminated nitrogen in an air separation device comprises a contaminated nitrogen compressor 1 connected to the air separation device, wherein the contaminated nitrogen compressor 1 is connected to a nitrogen storage tank 22 through a pre-deoxygenation unit and a nitrogen dehydration separation unit; a first tee 28 is provided between the contaminated nitrogen compressor 1 and the pre-deoxygenation unit, and the first tee 28 is connected to a hydrogen supply device 23 through a first hydrogen supplementation pipeline 24. The pre-deoxygenation unit comprises a shortcut pipeline with a shortcut valve 34 and a combustion deoxygenator 3 connected in series with the shortcut pipeline. The pre-deoxygenation unit also comprises a steam heater 2 arranged between the first tee 28 and the combustion deoxygenator 3 and connected in parallel with the shortcut pipeline. A connecting pipeline with an eleventh valve 21 is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, and a second tee 29 and a third tee 30 are provided at both ends of the connecting pipeline, respectively, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee 29 and the third end of the third tee 30. The series-parallel deep deoxygenation unit includes a pre-reactor cooler 4 connected to the third end of the second tee 29, and the outlet end of the pre-reactor cooler 4 is connected to the third end of the third tee 30 through the first combustion deoxygenator 5 and the second combustion deoxygenator 6 connected in parallel. The heating pre-deoxygenation unit and the second tee 29 are connected to the hydrogen supply device 23 through the second hydrogen supplementary pipeline 25. The outlet end of the first combustion deoxygenator 5 is provided with a fourth tee 31, and the inlet end of the second combustion deoxygenator 6 is provided with a fifth tee 32. The third end of the fourth tee 31 is connected to the third end of the fifth tee 32 through the first valve 14, the series cooler 16, the sixth tee 33 and the second valve 15; the third end of the sixth tee 33 is connected to the hydrogen supply device 23 through the third hydrogen supplementary pipeline 26. The outlet end of the pre-reactor cooler 4 and the first combustion deoxidizer 5 and the second combustion deoxidizer 5 are respectively provided with a third valve 10 and a fourth valve 11; the first combustion deoxidizer 5 and the second combustion deoxidizer 6 and the third end of the third three-way 30 are respectively provided with a fifth valve 12 and a sixth valve 13. The first hydrogen replenishing pipeline 24, the second hydrogen replenishing pipeline 25 and the third hydrogen replenishing pipeline 26 are respectively provided with a seventh valve 17, an eighth valve 18 and a ninth valve 19. The nitrogen dehydration separation unit comprises a reactor condenser 7, the reactor condenser 7 is connected to the inlet of the water separator 8, and the gas phase outlet of the water separator 8 is connected to the nitrogen storage tank 22 through the drying device 9; the liquid phase outlet of the water separator 8 is connected to the water storage tank 27 through the tenth valve 20.

[0122] A deoxygenation purification process for polluted nitrogen in an air separation device using a deoxygenation device, characterized in that the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the polluted nitrogen in the air separation device, and the low-oxygen content polluted nitrogen purification method comprises the following steps:

[0123] Step 1: The contaminated nitrogen from the air separation unit has an oxygen content of 0.6%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen is pressurized to 3.0 MPa by the contaminated nitrogen compressor 1, and the temperature rises to 95°C, and is mixed with hydrogen from outside the boundary;

[0124] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0125] Step 3: All oxygen is consumed by the reaction in the combustion deaerator 3; the temperature of the polluted nitrogen gas passing through the combustion deaerator 3 is 310°C, and the oxygen content is ≤10ppm;

[0126] Step 4: The nitrogen gas deoxygenated by the combustion deaerator 3 enters the reactor condenser 7 through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40° C.;

[0127] Step 5: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the other gas to produce qualified nitrogen;

[0128] Step 6: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0129] When the dirty nitrogen gas passing through the dirty nitrogen compressor 1 rises to 100°C, the mixed gas in step 2 is heated to not less than 100°C by the steam heater 2 and then enters the combustion deaerator 3;

[0130] The ratio of the hydrogen flow rate passing through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11.5:500.

[0131] Example 4

[0132] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0133] A deoxygenation purification process for a deoxygenation device for contaminated nitrogen in an air separation device, characterized in that: the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0134] The method for purifying polluted nitrogen with medium oxygen content comprises the following steps:

[0135] Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of 1.1%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 2.0 MPa at normal temperature and pressure by the contaminated nitrogen compressor 1, and then the temperature is raised to 120° C. and mixed with hydrogen from outside the boundary;

[0136] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0137] Step 3: A quarter of the oxygen in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 200°C;

[0138] Step 4: the polluted nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the eighth valve 18 and enters the pre-reactor cooler 4, and the temperature of the polluted nitrogen gas after cooling is reduced to 40°C;

[0139] Step 5: The cooled contaminated nitrogen gas passes through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively, and the remaining oxygen is reacted in the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively. The temperature after the reaction is 280° C. and the oxygen content is ≤10ppm;

[0140] Step 6: The nitrogen after passing through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 enters the reactor condenser 7, and the temperature is reduced to 40° C.;

[0141] Step 7: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0142] Step 8: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0143] The mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; the ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the dirty nitrogen flow rate from the air separation device in step 1 is 11:1000;

[0144] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 35:1000.

[0145] Example 5

[0146] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0147] A deoxygenation purification process for contaminated nitrogen in an air separation device using a deoxygenation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0148] The method for purifying polluted nitrogen with medium oxygen content comprises the following steps:

[0149] Step 1: The contaminated nitrogen from the air separation unit has an oxygen content of 2%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen is pressurized to 2.0 MPa at normal temperature and pressure by the contaminated nitrogen compressor 1, and then the temperature rises to 102°C, and is mixed with hydrogen from outside the boundary;

[0150] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0151] Step 3: A quarter of the oxygen in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 200°C;

[0152] Step 4: the polluted nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the eighth valve 18 and enters the pre-reactor cooler 4, and the temperature of the polluted nitrogen gas after cooling is reduced to 40°C;

[0153] Step 5: The cooled contaminated nitrogen gas passes through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively, and the remaining oxygen is reacted in the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively. The temperature after the reaction is 280° C. and the oxygen content is ≤10ppm;

[0154] Step 6: The nitrogen after passing through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 enters the reactor condenser 7, and the temperature is reduced to 40° C.;

[0155] Step 7: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0156] Step 8: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0157] The mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline; the ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the dirty nitrogen flow rate from the air separation device in step 1 is: 12:1000; the ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the dirty nitrogen flow rate from the air separation device in step 1 is: 34:1000.

[0158] Example 6

[0159] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0160] A deoxygenation purification process for a deoxygenation device for contaminated nitrogen in an air separation device, characterized in that: the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0161] The method for purifying polluted nitrogen with medium oxygen content comprises the following steps:

[0162] Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of 1.6%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen gas is pressurized to 2.0 MPa at normal temperature and pressure by the contaminated nitrogen compressor 1, and then the temperature rises to 85°C, and is mixed with hydrogen from outside the boundary;

[0163] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0164] Step 3: A quarter of the oxygen in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 200°C;

[0165] Step 4: the polluted nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the eighth valve 18 and enters the pre-reactor cooler 4, and the temperature of the polluted nitrogen gas after cooling is reduced to 40°C;

[0166] Step 5: The cooled contaminated nitrogen gas passes through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively, and the remaining oxygen is reacted in the first combustion deoxidizer 5 and the second combustion deoxidizer 6 respectively. The temperature after the reaction is 280° C. and the oxygen content is ≤10ppm;

[0167] Step 6: The nitrogen after passing through the first combustion deoxidizer 5 and the second combustion deoxidizer 6 enters the reactor condenser 7, and the temperature is reduced to 40° C.;

[0168] Step 7: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0169] Step 8: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0170] The mixed gas in step 2 is heated to 105°C by a steam heater 2 and then enters a combustion deaerator 3;

[0171] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11.5:1000;

[0172] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 34.5:1000.

[0173] Example 7

[0174] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0175] A deoxygenation purification process for contaminated nitrogen in an air separation device using a deoxygenation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0176] The method for purifying contaminated nitrogen with high oxygen content comprises the following steps:

[0177] Step 1: The contaminated nitrogen from the air separation unit has an oxygen content of 2.1%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen is pressurized to 0.5 MPa by the contaminated nitrogen compressor 1, and the temperature is raised by 100°C, and then mixed with hydrogen from outside the boundary;

[0178] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0179] Step 3: One sixth of the total oxygen content in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 180°C;

[0180] Step 4: the dirty nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the second hydrogen supply pipeline 25 and the eighth valve 18, and enters the pre-reactor cooler 4, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0181] Step 5: The contaminated nitrogen gas after cooling in step 4 enters the first combustion deaerator 5 through the third valve 10 for catalytic combustion deoxidation, consuming one third of the total oxygen content in the contaminated nitrogen gas; the temperature of the contaminated nitrogen gas after passing through the first combustion deaerator 5 is 200°C;

[0182] Step 6: The contaminated nitrogen after passing through the first combustion deaerator 5 passes through the first valve 14 and the series cooler 16 in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline 26. After mixing, it passes through the second valve 15 and the fifth three-way 32 to enter the second combustion deaerator 6, and is deoxidized by catalytic combustion to consume all oxygen in the contaminated nitrogen. The nitrogen temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0183] Step 7: The nitrogen passing through the second combustion deaerator 6 enters the reactor condenser 7, and the temperature is reduced to 40°C;

[0184] Step 8: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0185] Step 9: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0186] The mixed gas in step 2 enters the combustion deaerator 3 through a shortcut pipeline;

[0187] The ratio of the hydrogen flow rate passing through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 1:100;

[0188] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11:500;

[0189] The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline 26 in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 33:1000.

[0190] Example 8

[0191] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0192] A deoxygenation purification process for contaminated nitrogen in an air separation device using a deoxygenation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0193] The method for purifying contaminated nitrogen with high oxygen content comprises the following steps:

[0194] Step 1: The dirty nitrogen from the air separation unit has an oxygen content of 3%, a pressure of 5 KPa, and a normal temperature. The dirty nitrogen is pressurized to 0.5 MPa by the dirty nitrogen compressor 1, and the temperature rises to 93°C, and is mixed with hydrogen from outside the boundary;

[0195] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0196] Step 3: One sixth of the total oxygen content in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 180°C;

[0197] Step 4: the dirty nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the second hydrogen supply pipeline 25 and the eighth valve 18, and enters the pre-reactor cooler 4, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0198] Step 5: The contaminated nitrogen gas after cooling in step 4 enters the first combustion deaerator 5 through the third valve 10 for catalytic combustion deoxidation, consuming one third of the total oxygen content in the contaminated nitrogen gas; the temperature of the contaminated nitrogen gas after passing through the first combustion deaerator 5 is 200°C;

[0199] Step 6: The contaminated nitrogen after passing through the first combustion deaerator 5 passes through the first valve 14 and the series cooler 16 in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline 26. After mixing, it passes through the second valve 15 and the fifth three-way 32 to enter the second combustion deaerator 6, and is deoxidized by catalytic combustion to consume all oxygen in the contaminated nitrogen. The nitrogen temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0200] Step 7: The nitrogen passing through the second combustion deaerator 6 enters the reactor condenser 7, and the temperature is reduced to 40°C;

[0201] Step 8: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0202] Step 9: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0203] The mixed gas in step 2 is heated to 108°C by a steam heater 2 and then enters a combustion deaerator 3;

[0204] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 6:500;

[0205] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 12:500;

[0206] The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline 26 in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 35:1000.

[0207] Example 9

[0208] The structure of a deoxygenation device for polluted nitrogen gas in an air separation device is the same as that of the above-mentioned embodiment 1.

[0209] A deoxygenation purification process for contaminated nitrogen in an air separation device using a deoxygenation device, wherein the deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method;

[0210] The method for purifying contaminated nitrogen with high oxygen content comprises the following steps:

[0211] Step 1: The contaminated nitrogen from the air separation unit has an oxygen content of 2.5%, a pressure of 5 KPa, and a normal temperature. The contaminated nitrogen is pressurized to 0.5 MPa by the contaminated nitrogen compressor 1, and the temperature rises to 83°C, and is mixed with hydrogen from outside the boundary;

[0212] Step 2: The hydrogen flow is controlled by the seventh valve 17 to be a constant flow, and the mixed gas enters the combustion deaerator 3 through the steam heater 2 or the shortcut pipeline;

[0213] Step 3: One sixth of the total oxygen content in the polluted nitrogen is consumed in the combustion deaerator 3, and the temperature of the polluted nitrogen passing through the combustion deaerator 3 is 180°C;

[0214] Step 4: the dirty nitrogen gas after the reaction in the combustion deaerator 3 is mixed with the hydrogen from the second hydrogen supply pipeline 25 and the eighth valve 18, and enters the pre-reactor cooler 4, and the temperature of the cooled dirty nitrogen gas is reduced to 40°C;

[0215] Step 5: The contaminated nitrogen gas after cooling in step 4 enters the first combustion deaerator 5 through the third valve 10 for catalytic combustion deoxidation, consuming one third of the total oxygen content in the contaminated nitrogen gas; the temperature of the contaminated nitrogen gas after passing through the first combustion deaerator 5 is 200°C;

[0216] Step 6: The contaminated nitrogen after passing through the first combustion deaerator 5 passes through the first valve 14 and the series cooler 16 in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline 26. After mixing, it passes through the second valve 15 and the fifth three-way 32 to enter the second combustion deaerator 6, and is deoxidized by catalytic combustion to consume all oxygen in the contaminated nitrogen. The nitrogen temperature after the reaction is 280°C, and the oxygen content is ≤10ppm;

[0217] Step 7: The nitrogen passing through the second combustion deaerator 6 enters the reactor condenser 7, and the temperature is reduced to 40°C;

[0218] Step 8: The cooled material after the reactor condenser 7 is passed through a water separator 8 to separate the reaction water, and the separated gas enters a drying device 9 to dry and remove the saturated water in the gas, thereby producing qualified nitrogen;

[0219] Step 9: The reaction water separated by the water separator 8 enters the water storage tank 27 through the tenth valve 20;

[0220] Step 2: The mixed gas is heated to 100°C by a steam heater 2 and then enters a combustion deaerator 3;

[0221] The ratio of the hydrogen flow rate through the seventh valve 17 in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 5.5:500;

[0222] The ratio of the hydrogen flow rate through the eighth valve 18 in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11.5:500;

[0223] The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline 26 in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 34:1000.

[0224] It should be noted that the seventh valve 17, the eighth valve 18 and the ninth valve 19 in the above embodiment are used to control the hydrogen flow rate of the corresponding first hydrogen replenishment pipeline 24, the second hydrogen replenishment pipeline 25 and the third hydrogen replenishment pipeline 26 entering the system, and the hydrogen flow can be adjusted according to the oxygen content in the contaminated nitrogen and the position of each combustion deaerator, and its main purpose is to ensure that each combustion deaerator achieves the required reaction effect of removing oxygen content. The present invention is based on the existing air separation unit, and the contaminated nitrogen deoxygenation process route with incremental nitrogen product has the advantages of less investment, simple process, large product output, high product purity, etc. compared with the existing technology for increasing nitrogen products, and can effectively solve the incremental demand for nitrogen products in the development of existing chemical parks.

[0225] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0226] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deoxygenation device for contaminated nitrogen in an air separation device, comprising a contaminated nitrogen compressor (1) connected to the air separation device, characterized in that: The dirty nitrogen compressor (1) is connected to the nitrogen storage tank (22) via a pre-deoxygenation unit and a nitrogen dehydration separation unit; A first tee (28) is provided between the dirty nitrogen compressor (1) and the pre-deoxygenation unit, and the first tee (28) is connected to the hydrogen supply device (23) through a first hydrogen replenishment pipeline (24); The pre-deoxygenation unit comprises a shortcut pipeline with a shortcut valve (34) and a combustion deoxygenator (3) connected in series with the shortcut pipeline; A connecting pipe with an eleventh valve (21) is provided between the pre-deoxygenation unit and the nitrogen dehydration separation unit, a second tee (29) and a third tee (30) are provided at both ends of the connecting pipe, and a series-parallel deep deoxygenation unit is provided between the third end of the second tee (29) and the third end of the third tee (30); The series-parallel deep deoxygenation unit comprises a pre-reactor cooler (4) connected to the third end of the second tee (29); the outlet end of the pre-reactor cooler (4) is connected to the third end of the third tee (30) via a first combustion deoxygenator (5) and a second combustion deoxygenator (6) connected in parallel; The outlet end of the first combustion deaerator (5) is provided with a fourth tee (31), the inlet end of the second combustion deaerator (6) is provided with a fifth tee (32), and the third end of the fourth tee (31) is connected to the third end of the fifth tee (32) via the first valve (14), the series cooler (16), the sixth tee (33) and the second valve (15); The third end of the sixth three-way valve (33) is connected to the hydrogen supply device (23) via a third hydrogen supply pipeline (26).

2. The deoxygenation device for polluted nitrogen in the air separation device according to claim 1, characterized in that: The pre-deoxygenation unit further comprises a steam heater (2) which is arranged between the first tee (28) and the combustion deoxygenator (3) and is connected in parallel with the shortcut pipeline.

3. The deoxygenation device for polluted nitrogen in the air separation device according to claim 1, characterized in that: The pre-deoxygenation unit and the second three-way connection (29) are connected to the hydrogen supply device (23) via a second hydrogen replenishment pipeline (25).

4. The deoxygenation device for polluted nitrogen in the air separation device according to claim 1, characterized in that: A third valve (10) and a fourth valve (11) are respectively provided between the outlet end of the pre-reactor cooler (4) and the first combustion deoxidizer (5) and the second combustion deoxidizer (5); a fifth valve (12) and a sixth valve (13) are respectively provided between the first combustion deoxidizer (5) and the second combustion deoxidizer (6) and the third end of the third three-way valve (30); A seventh valve (17), an eighth valve (18) and a ninth valve (19) are respectively provided on the first hydrogen replenishing pipeline (24), the second hydrogen replenishing pipeline (25) and the third hydrogen replenishing pipeline (26).

5. The deoxygenation device for polluted nitrogen in an air separation device according to any one of claims 1 to 4, characterized in that: The nitrogen dehydration separation unit comprises a reactor condenser (7), the reactor condenser (7) is connected to the inlet of a water separator (8), the gas phase outlet of the water separator (8) is connected to a nitrogen storage tank (22) via a drying device (9); the liquid phase outlet of the water separator (8) is connected to a water storage tank (27) via a tenth valve (20).

6. A deoxygenation purification process using a deoxygenation device for polluted nitrogen in an air separation device according to any one of claims 1 to 5, characterized in that: The deoxygenation purification process is a deoxygenation purification method using different paths according to the oxygen content of the contaminated nitrogen in the air separation device, including a low-oxygen-content contaminated nitrogen purification method, a medium-oxygen-content contaminated nitrogen purification method, and a high-oxygen-content contaminated nitrogen purification method; The oxygen content in the contaminated nitrogen gas in the low oxygen content contaminated nitrogen gas purification method is: X, 0.2 ≤ X ≤ 1%, the oxygen content in the contaminated nitrogen gas in the medium oxygen content contaminated nitrogen gas purification method is: Y, 1 < Y ​​≤ 2%, and the oxygen content in the contaminated nitrogen gas in the high oxygen content contaminated nitrogen gas purification method is: Z, 2 < Z ≤ 3%; 1. The method for purifying low oxygen content contaminated nitrogen includes the following steps: Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of X, a pressure of 5 KPa and a normal temperature. The contaminated nitrogen gas is pressurized to 3.0 MPa by a contaminated nitrogen compressor (1), and the temperature is raised, and the gas is mixed with hydrogen from outside the air separation unit. Step 2: The hydrogen flow is controlled by the seventh valve (17) to be constant, and the mixed gas enters the combustion deaerator (3) through the steam heater (2) or the shortcut pipeline; Step 3: All oxygen is consumed by the reaction in the combustion deaerator (3); the temperature of the polluted nitrogen gas passing through the combustion deaerator (3) is 310°C and the oxygen content is ≤10ppm; Step 4: The nitrogen gas deoxygenated by the combustion deaerator (3) enters the reactor condenser (7) through the connecting pipe with the eleventh valve 21, and the temperature is reduced to 40°C; Step 5: The cooled material after the reactor condenser (7) is passed through a water separator (8) to separate the reaction water, and the separated gas enters a drying device (9) to dry and remove the saturated water in the gas, thereby producing qualified nitrogen gas; Step 6: The reaction water separated by the water separator (8) enters the water storage tank (27) through the tenth valve (20); When the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) in the above step 1 rises to not less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) through a shortcut pipeline; when the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) rises to less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) after being heated to not less than 100° C. by a steam heater (2); The ratio of the hydrogen flow rate passing through the seventh valve (17) in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500; 2. The method for purifying polluted nitrogen gas with medium oxygen content comprises the following steps: Step 1: The contaminated nitrogen gas from the air separation unit has an oxygen content of Y, a pressure of 5 KPa and a normal temperature. The contaminated nitrogen gas is pressurized to 2.0 MPa by a contaminated nitrogen compressor (1) and then the temperature is raised and the gas is mixed with hydrogen from outside. Step 2: The hydrogen flow is controlled by the seventh valve (17) to be constant, and the mixed gas enters the combustion deaerator (3) through the steam heater (2) or the shortcut pipeline; Step 3: A quarter of the oxygen in the polluted nitrogen gas is consumed in the combustion deaerator (3), and the temperature of the polluted nitrogen gas passing through the combustion deaerator (3) is 200°C; Step 4: the waste nitrogen gas after the reaction in the combustion deaerator (3) is mixed with the hydrogen from the eighth valve (18) and enters the pre-reactor cooler (4), and the temperature of the waste nitrogen gas after cooling is reduced to 40°C; Step 5: the contaminated nitrogen gas after cooling passes through the first combustion deoxidizer (5) and the second combustion deoxidizer (6) respectively, and the remaining oxygen is reacted in the first combustion deoxidizer (5) and the second combustion deoxidizer (6) respectively, and the temperature after the reaction is 280° C. and the oxygen content is ≤10 ppm; Step 6: The nitrogen after passing through the first combustion deaerator (5) and the second combustion deaerator (6) enters the reactor condenser (7), and the temperature is reduced to 40° C.; Step 7: The cooled material after the reactor condenser (7) is passed through a water separator (8) to separate the reaction water, and the separated gas enters a drying device (9) to dry and remove the saturated water in the gas, thereby producing qualified nitrogen gas; Step 8: The reaction water separated by the water separator (8) enters the water storage tank (27) through the tenth valve (20); When the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) in the above step 1 rises to not less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) through a shortcut pipeline; when the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) rises to less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) after being heated to not less than 100° C. by a steam heater (2); The ratio of the hydrogen flow rate passing through the seventh valve (17) in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:1000; The ratio of the hydrogen flow rate through the eighth valve (18) in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 34-35:1000; 3. The method for purifying polluted nitrogen with high oxygen content comprises the following steps: Step 1: The contaminated nitrogen gas from the air separation device has an oxygen content of Z, a pressure of 5 KPa and a normal temperature. The contaminated nitrogen gas passes through a contaminated nitrogen compressor (1) to pressurize the contaminated nitrogen gas at normal temperature and pressure to 0.5 MPa, and then the temperature is raised and the gas is mixed with hydrogen from outside the air separation device. Step 2: The hydrogen flow is controlled by the seventh valve (17) to be constant, and the mixed gas enters the combustion deaerator (3) through the steam heater (2) or the shortcut pipeline; Step 3: One sixth of the total oxygen content in the polluted nitrogen gas is consumed in the combustion deaerator (3), and the temperature of the polluted nitrogen gas passing through the combustion deaerator (3) is 180° C.; Step 4: the waste nitrogen gas after the reaction in the combustion deaerator (3) is mixed with the hydrogen from the second hydrogen supply pipeline (25) and the eighth valve (18), and enters the pre-reactor cooler (4), and the temperature of the waste nitrogen gas after cooling is reduced to 40°C; Step 5: the contaminated nitrogen gas after cooling in step 4 enters the first combustion deaerator (5) through the third valve (10) for catalytic combustion deoxygenation, consuming one third of the total oxygen content in the contaminated nitrogen gas; the temperature of the contaminated nitrogen gas after passing through the first combustion deaerator (5) is 200°C; Step 6: The contaminated nitrogen gas after passing through the first combustion deaerator (5) passes through the first valve (14) and the series cooler (16) in sequence, and is mixed with the hydrogen supplied from the third hydrogen supply pipeline (26). After mixing, the gas enters the second combustion deaerator (6) through the second valve (15) and the fifth three-way (32), and undergoes catalytic combustion and deoxidation to consume all oxygen in the contaminated nitrogen gas. The nitrogen gas temperature after the reaction is 280°C, and the oxygen content is ≤10ppm; Step 7: The nitrogen gas passing through the second combustion deaerator (6) enters the reactor condenser (7), and the temperature is reduced to 40°C; Step 8: The cooled material after the reactor condenser (7) is passed through a water separator (8) to separate the reaction water, and the separated gas enters a drying device (9) to dry and remove the saturated water in the gas, thereby producing qualified nitrogen gas; Step 9: The reaction water separated by the water separator (8) enters the water storage tank (27) through the tenth valve (20); When the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) in the above step 1 rises to not less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) through a shortcut pipeline; when the temperature of the dirty nitrogen gas passing through the dirty nitrogen gas compressor (1) rises to less than 100° C., the mixed gas in step 2 enters the combustion deaerator (3) after being heated to not less than 100° C. by a steam heater (2); The ratio of the hydrogen flow rate passing through the seventh valve (17) in step 2 to the contaminated nitrogen flow rate from the air separation device in step 1 is 5-6:500; The ratio of the hydrogen flow rate passing through the eighth valve (18) in step 4 to the contaminated nitrogen flow rate from the air separation device in step 1 is 11-12:500; The ratio of the flow rate of hydrogen supplemented through the third hydrogen supplement pipeline (26) in step 6 to the flow rate of the contaminated nitrogen from the air separation device in step 1 is 33-35:1000.

Images