Process and equipment for recovering oxygen from waste gas discharged from organic fluoride production

Abstract

The invention discloses a process and equipment for recovering oxygen from waste gas discharged during organic fluoride production, and belongs to waste gas recovery treatment.The process comprises the following steps that the waste gas is cooled to-65 DEG C to-68 DEG C through a first-stage heat exchanger, and ethyl alcohol and ether impurities are removed; the waste gas enters a gas-liquid separation tank I for gas-liquid separation; the waste gas enters a secondary heat exchanger to be cooled to-85 DEG C to-88 DEG C, and fluorine impurities are removed; the waste gas enters a second gas-liquid separation tank to be subjected to gas-liquid separation, the separated gas is fed into an adsorption tank containing an adsorbent to adsorb trace residual organic matter, and purified gas sequentially passes through a second-stage heat exchanger and a first-stage heat exchanger to be subjected to cold energy recovery and reheated to the normal temperature; liquid oxygen enters the Dewar tank and then sequentially passes through the second-stage heat exchanger and the first-stage heat exchanger for heat exchange, and the cooling capacity needed by operation is supplemented; and the purified gas is conveyed to the production link of the organic fluoride through the product gas pipeline. The method has the advantages of reducing resource waste, reducing production cost, improving oxygen production utilization rate, saving equipment investment, being small in occupied area of equipment and the like.

Description

Technical Field

[0001] The present invention relates to waste gas recovery and treatment, and in particular to a process and equipment for recovering oxygen from waste gas discharged during the production of organic fluorides. Background Art

[0002] At present, a large amount of waste gas is generated and discharged in the production of organic fluorides. The main reason is that oxygen is used to produce ozone in the production process of organic fluorides. The generation of ozone accounts for 5-10%. Ozone enters the reaction tank to participate in the reaction to produce related products. After the reaction, the remaining waste gas is discharged. The discharged waste gas contains fluorine and other chemical solvents. The waste gas emissions do not meet the national direct discharge requirements. Therefore, wastes such as fluorine and chemical solvents need to be collected and treated. The chemical solvents contained in the waste gas have low boiling point characteristics. Traditional waste gas treatment systems (such as Figure 1 ) Generally, multiple low-temperature cold wells are set up, for example, a -65℃ cold well and a -85℃ cold well are set up in series, and the exhaust gas is sent into the cold well to collect the impurities in the gas at low temperature according to the different liquefaction points. After purification, the exhaust gas is sent to the combustion furnace for combustion.

[0003] The waste gas treatment process in the prior art has the following disadvantages:

[0004] 1) The production of organic fluorides requires continuous oxygen consumption. If the user does not have oxygen production equipment, multiple cryogenic liquid storage tanks are needed to store large quantities of liquid oxygen. This increases production and labor costs. Furthermore, only 5-10% of the oxygen used in production is used to generate ozone, with the remaining 90-95% being discharged as waste gas, resulting in a significant waste of resources.

[0005] 2) It is necessary to set up multiple cold wells and equip refrigeration devices, fans, incinerators and other equipment. There are disadvantages such as large equipment footprint, large investment and high energy consumption.

[0006] Based on this, the present invention designs a process and equipment for recovering oxygen from waste gas discharged from the production of organic fluoride to solve the above problems. Summary of the Invention

[0007] In response to the above-mentioned shortcomings of the prior art, the present invention provides a process and equipment for recovering oxygen from waste gas discharged from the production of organic fluorides. 90-95% of the oxygen discharged as waste gas is recovered and purified, and then returned to production for use after meeting the use standards.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A process for recovering oxygen from waste gas discharged from the production of organic fluoride comprises the following steps:

[0010] Step 1: The exhaust gas enters the Dewar tank and first passes through a primary heat exchanger to cool the exhaust gas to -65 to -68°C, liquefying and removing ethanol and ether impurities in the exhaust gas;

[0011] Step 2: The waste gas then enters the gas-liquid separation tank 1 for gas-liquid separation;

[0012] Step 3: The exhaust gas then enters the secondary heat exchanger, where it is cooled to -85 to -88°C and fluorine impurities in the exhaust gas are removed.

[0013] Step 4: The waste gas then enters the gas-liquid separation tank 2 for gas-liquid separation. After separation, the gas is sent to an adsorption tank filled with adsorbent to adsorb trace residual organic matter. The outlet gas is purified gas, which can meet high-purity oxygen standards. The purified gas after adsorption passes through the secondary heat exchanger and the primary heat exchanger in turn for cold recovery and reheating to room temperature.

[0014] Step 5: After the liquid oxygen enters the Dewar tank, it passes through the secondary heat exchanger and the primary heat exchanger in turn to exchange heat and replenish the cooling capacity required for operation;

[0015] Step 6: The purified gas is transported to the production link of organic fluoride through the product gas pipeline;

[0016] The adsorbent comprises the following raw materials in parts by weight: 3 to 6 parts of MoS2 powder, 28 to 31 parts of polyvinyl alcohol, 50 to 55 parts of activated carbon, and 11 to 16 parts of irradiated modified chitosan. During preparation, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are evenly mixed, the mixture and MoS2 powder are ultrasonically treated together, the MoS2 is peeled off into two-dimensional MoS2 nanosheets, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are ultrasonically crushed into mixed nanoparticles, the mixed nanoparticles are added to a mixture of 2 to 3 times the mass of isopropanol and water, MoS2 is added after evenly mixing, stirring is continued for 20 to 30 minutes, the mixture is placed at a low temperature of -22 to -25°C and allowed to stand for 8 to 12 hours, and then dried, calcined at 250 to 260°C, ground, and formed to obtain the adsorbent. The adsorbent has an adsorption effect on hydrogen fluoride: a purification rate of 98.9 to 99.6%, and an adsorption capacity of 97.7 to 114.6 mg / g. Furthermore, in step 1, the primary heat exchanger cools the exhaust gas to -68°C to remove ethanol and ether impurities in the exhaust gas.

[0017] Furthermore, in step three, the secondary heat exchanger cools the exhaust gas to -88°C to remove fluorine impurities in the exhaust gas.

[0018] Furthermore, in step 4, the liquefied organic matter solutions collected in the gas-liquid separation tank 1 and the gas-liquid separation tank 2 are discharged and then processed uniformly.

[0019] Furthermore, in step six, the oxygen gasified in step five is connected to the purified gas and transported to the production link of organic fluoride through the product gas pipeline.

[0020] In order to better achieve the purpose of the present invention, the present invention also provides an apparatus for recovering oxygen from waste gas discharged from the production of organic fluorides, comprising a Dewar tank, a primary heat exchanger, a gas-liquid separation tank I, a secondary heat exchanger, an adsorption tank and a gas-liquid separation tank II; the primary heat exchanger, the gas-liquid separation tank I, the secondary heat exchanger, the adsorption tank and the gas-liquid separation tank II are all installed in the Dewar tank, the waste gas pipeline is connected to the Dewar tank and then sequentially connected to the primary heat exchanger, the gas-liquid separation tank I, the secondary heat exchanger, the gas-liquid separation tank II and the adsorption tank, the gas outlet of the adsorption tank is sequentially connected to the secondary heat exchanger, the primary heat exchanger and the product gas pipeline outside the Dewar tank through a pipeline; the liquid oxygen pipeline is connected to the Dewar tank and then sequentially connected to the secondary heat exchanger and the primary heat exchanger.

[0021] Furthermore, a low-temperature valve is connected between the first-stage heat exchanger and the gas-liquid separation tank.

[0022] Furthermore, a low-temperature valve is connected between the secondary heat exchanger and the second gas-liquid separation tank.

[0023] Furthermore, the bottoms of the gas-liquid separation tank 1 and the gas-liquid separation tank 2 are connected to the liquefied organic solution discharge pipeline; the liquid oxygen pipeline is connected to the Dewar tank and then connected to the secondary heat exchanger, the primary heat exchanger, and the product gas pipeline outside the Dewar tank in sequence.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. Compared with the traditional waste gas treatment system, the present invention can recover and purify the oxygen in the waste gas discharged in the production of organic fluorides and reuse it.

[0025] 2. The present invention recycles oxygen from waste gas, greatly reducing resource waste and production costs. The oxygen production utilization rate is ≥90%, and users do not need to store large amounts of liquid oxygen.

[0026] 3. The equipment of the present invention adopts an integrated design, the equipment is small in size, occupies a small area, consumes no electricity, and can save electricity by replacing traditional exhaust gas treatment equipment.

[0027] 4. The equipment of the present invention uses liquid oxygen as a cooling source, eliminating the need for an external refrigerator. This can save equipment costs. On the other hand, liquid oxygen needs to be vaporized before use. The liquid oxygen vaporization process in traditional waste gas treatment systems wastes cooling energy. The present invention can recycle and reuse this cooling energy, thus avoiding cooling energy waste.

[0028] 5. The present invention does not require an incinerator, thus saving equipment investment.

[0029] 6. The present invention comprehensively considers existing conditions, recovers the cold energy of liquid oxygen vaporization, and uses liquid oxygen as a cold source to achieve low-temperature liquefaction. The present invention completes the recovery and reuse of user waste gas under the premise of low consumption. The present invention simplifies the waste gas treatment process and reduces waste gas emissions. After the waste gas is recovered and purified, it can be transported to the production link of organic fluoride and put into practical use, saving oxygen consumption and reducing production costs. The use of the present invention can reduce the user's equipment investment costs, save production power consumption, reduce equipment space, and greatly reduce the user's production costs.

[0030] 7. The present invention optimizes the adsorbent composition and preparation method in the adsorption tank, which is conducive to further removing residual organic matter (such as fluoride). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0032] Figure 1 This is a structural diagram of a traditional exhaust gas treatment system.

[0033] Figure 2 This is a structural diagram of the equipment for recovering oxygen from waste gas discharged during the production of organic fluoride according to the present invention.

[0034] The numbers in the figure represent:

[0035] 1. Dewar tank; 2. Primary heat exchanger; 3. Cryogenic valve; 4. Gas-liquid separator tank (1); 5. Secondary heat exchanger; 6. Adsorption tank; 7. Gas-liquid separator tank (2); 8. Product gas pipeline; 9. Waste gas pipeline; 10. Liquid oxygen pipeline. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] Example 1: Please refer to the accompanying drawings of the specification Figure 2, equipment for recovering oxygen from waste gas discharged from the production of organic fluoride, including a dewar tank 1, a primary heat exchanger 2, a gas-liquid separation tank 1 4, a secondary heat exchanger 5, an adsorption tank 6 and a gas-liquid separation tank 2 7; the primary heat exchanger 2, the gas-liquid separation tank 1 4, the secondary heat exchanger 5, the adsorption tank 6 and the gas-liquid separation tank 2 7 are all installed in the dewar tank 1, and the waste gas pipeline 9 is connected to the dewar tank 1 and then connected to the primary heat exchanger 2, the cryogenic valve 3, the gas-liquid separation tank 1 4, the secondary heat exchanger 5, the cryogenic valve 3, the gas-liquid separation tank 2 7 and the adsorption tank 6 in sequence, and the gas outlet of the adsorption tank 6 is connected to the secondary heat exchanger 5, the primary heat exchanger 2 and the product gas pipeline 8 outside the dewar tank 1 in sequence through a pipeline; the bottoms of the gas-liquid separation tank 1 4 and the gas-liquid separation tank 2 7 are connected to the liquefied organic solution discharge pipeline; the liquid oxygen pipeline 10 is connected to the dewar tank 1 and then connected to the secondary heat exchanger 5, the primary heat exchanger 2 and the product gas pipeline 8 outside the dewar tank 1 in sequence.

[0038] The principle is: the waste gas enters the Dewar tank 1 for purification, first passes through the first-level heat exchanger 2 to cool the waste gas to -65 ~ -68 ℃, and liquefies and removes impurities such as ethanol and ether in the waste gas; then the waste gas enters the gas-liquid separation tank 1 4 for gas-liquid separation; then the waste gas enters the second-level heat exchanger 5, and cools the waste gas to -85 ~ -88 ℃ through the second-level heat exchanger 5 to remove impurities such as fluorine; then the waste gas enters the gas-liquid separation tank 2 7 for gas-liquid separation, and the separated gas is sent to the adsorption tank 6 filled with adsorbent to adsorb trace residual organic matter and export The gas is purified gas, which can meet high-purity oxygen standards; the purified gas after adsorption passes through the secondary heat exchanger 5 and the primary heat exchanger 2 in sequence for cold recovery and reheating to room temperature; the liquefied organic solution collected in the gas-liquid separation tank 1 4 and the gas-liquid separation tank 2 7 is discharged and can be uniformly treated as waste; after entering the Dewar tank 1, the liquid oxygen passes through the secondary heat exchanger 5 and the primary heat exchanger 2 in sequence for heat exchange to supplement the cold required for operation. After the liquid oxygen is vaporized, it is connected to the grid with the purified gas and transported to the production link of organic fluoride through the product gas pipeline 8 for actual use.

[0039] Example 2: Please refer to the attached drawings of the specification Figure 2 The process for recovering oxygen from waste gas discharged from the production of organic fluoride comprises the following steps:

[0040] Step 1: The exhaust gas enters the Dewar tank 1 and first passes through the primary heat exchanger 2 to cool the exhaust gas to -65 to -68°C. The subcooling degree can be designed to be +3°C to enhance the liquefaction effect and liquefy and remove impurities such as ethanol and ether in the exhaust gas;

[0041] Step 2: The waste gas then enters the gas-liquid separation tank 4 for gas-liquid separation;

[0042] Step 3: The exhaust gas then enters the secondary heat exchanger 5, where it is cooled to -85--88°C to remove impurities such as fluorine.

[0043] Step 4: The waste gas then enters the gas-liquid separation tank 2 7 for gas-liquid separation. After separation, the gas is sent to the adsorption tank 6 filled with adsorbent to adsorb trace residual organic matter. The outlet gas is purified gas, which can meet high-purity oxygen standards. The purified gas after adsorption passes through the secondary heat exchanger 5 and the primary heat exchanger 2 in sequence for cold recovery and reheating to room temperature. The liquefied organic matter solution collected in the gas-liquid separation tank 1 4 and the gas-liquid separation tank 2 7 is discharged and can be uniformly treated.

[0044] Step 5: Connect the liquid oxygen pipeline to the Dewar tank 1. Liquid oxygen is used to provide a cold source for the low-temperature operation of the equipment. The liquid oxygen is vaporized in the secondary heat exchanger 5 and the primary heat exchanger 2 to achieve temperature-zoned and graded cold recovery. After entering the Dewar tank 1, the liquid oxygen passes through the secondary heat exchanger 5 (-161°C) and the primary heat exchanger 2 (-122°C) in sequence for heat exchange to supplement the cold required for operation. After vaporization, the liquid oxygen is connected to the purified gas and transported to the production link of organic fluoride through the product gas pipeline 8 for actual use.

[0045] The device of the present invention works at low temperatures, so the purification equipment is placed in a Dewar tank 1 with good thermal insulation effect; the Dewar tank 1 is a container commonly used in low-temperature working conditions. The container is designed as a double-layer container, divided into an inner and outer cylinder, with a certain gap left between the two cylinders. The intermediate gap is used to evacuate the container and achieve thermal insulation effect by using the vacuum; the low-temperature effect can be effectively and efficiently achieved, which is different from the structure of a cold storage box with thermal insulation material, and can ensure that the container has the characteristics of high thermal insulation and small size.

[0046] The oxygen recovery and purification process of the present invention is carried out in a closed system without contact with air, and no water or carbon dioxide is generated during the process. Therefore, there is no ice blockage when the waste gas enters the low temperature.

[0047] Compared with the traditional waste gas treatment system, the present invention can recover and purify the oxygen in the waste gas discharged in the production of organic fluorides for reuse.

[0048] The present invention recycles oxygen from waste gas, greatly reducing resource waste and production costs. The oxygen production utilization rate is ≥90%, and users do not need to store large amounts of liquid oxygen.

[0049] The device of the present invention adopts an integrated design, has a small size, occupies a small area, consumes no electricity, and can replace traditional waste gas treatment equipment to save electricity;

[0050] The device of the present invention uses liquid oxygen as a cooling source, eliminating the need for an external refrigerator. This can save equipment costs. Furthermore, the liquid oxygen needs to be vaporized before use. The liquid oxygen vaporization process in conventional waste gas treatment systems wastes cooling energy. The present invention can recycle and reuse this cooling energy, thus avoiding cooling waste.

[0051] The present invention does not require an incinerator, thus saving equipment investment.

[0052] The present invention comprehensively considers existing conditions, recovers the cold energy of liquid oxygen vaporization, and uses liquid oxygen as a cold source to achieve low-temperature liquefaction. The present invention completes the recovery and reuse of user waste gas under the premise of low consumption. The present invention simplifies the waste gas treatment process and reduces waste gas emissions. After the waste gas is recovered and purified, it can be transported to the production link of organic fluoride and put into practical use, saving oxygen consumption and reducing production costs. The use of the present invention can reduce the user's equipment investment cost, save production power consumption, reduce equipment space, and greatly reduce the user's production cost.

[0053] Example 3: The present invention further optimizes the adsorbent in the adsorption tank 6, comprising the following raw materials in parts by weight: 4 parts of MoS2 powder, 30 parts of polyvinyl alcohol, 54 parts of activated carbon, and 12 parts of irradiated modified chitosan (chitosan is irradiated with gamma rays twice, with an irradiation dose of 1.5 Mrad each time); during preparation, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are mixed evenly, and the mixture and MoS2 powder are ultrasonically treated together, and MoS2 is peeled off into two-dimensional MoS2 nanosheets, and the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are ultrasonically broken into mixed nanoparticles, and the mixed nanoparticles are added to a mixture of 3 times the mass of isopropanol and water (mass ratio 1:4), mixed evenly, and MoS2 is added, and stirring is continued for 20 minutes, and the mixture is placed at a low temperature of -20°C and allowed to stand for 10 hours, and then dried, calcined at 255°C, ground, and formed to obtain the adsorbent.

[0054] The adsorption effect of the adsorbent on hydrogen fluoride was tested: the purification rate was 99.2%, and the adsorption capacity was 108.6 mg / g.

[0055] Example 4: The adsorbent in the adsorption tank 6 includes the following raw materials in parts by weight: 6 parts of MoS2 powder, 28 parts of polyvinyl alcohol, 50 parts of activated carbon, and 16 parts of irradiated modified chitosan (chitosan is irradiated with gamma rays twice, with an irradiation dose of 3.2 Mrad each time); during preparation, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are mixed evenly, and the mixture and MoS2 powder are ultrasonically treated together, and MoS2 is peeled off into two-dimensional MoS2 nanosheets. The polyvinyl alcohol, activated carbon, and irradiated modified chitosan are ultrasonically crushed into mixed nanoparticles, and the mixed nanoparticles are added to a mixture of 2 times the mass of isopropanol and water (mass ratio 1:3), mixed evenly, and MoS2 is added, and stirring is continued for 30 minutes. The mixture is placed at a low temperature of -22°C and allowed to stand for 12 hours, and then dried, calcined at 260°C, ground, and formed to obtain the adsorbent.

[0056] The adsorption effect of the adsorbent on hydrogen fluoride was tested: the purification rate was 98.9%, and the adsorption capacity was 114.6 mg / g.

[0057] Example 5: The adsorbent in the adsorption tank 6 includes the following raw materials in parts by weight: 3 parts of MoS2 powder, 31 parts of polyvinyl alcohol, 55 parts of activated carbon, and 11 parts of irradiated modified chitosan (chitosan is irradiated with gamma rays twice, with an irradiation dose of 2.8 Mrad each time); during preparation, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are mixed evenly, and the mixture and MoS2 powder are ultrasonically treated together, and MoS2 is peeled off into two-dimensional MoS2 nanosheets. The polyvinyl alcohol, activated carbon, and irradiated modified chitosan are ultrasonically crushed into mixed nanoparticles, and the mixed nanoparticles are added to a mixture of 3 times the mass of isopropanol and water (mass ratio 1:5), mixed evenly, and MoS2 is added, and stirring is continued for 20 minutes. The mixture is placed at a low temperature of -25°C and allowed to stand for 8 hours, and then dried, calcined at 250°C, ground, and formed to obtain the adsorbent.

[0058] The adsorption effect of the adsorbent on hydrogen fluoride was tested: the purification rate was 99.6%, and the adsorption capacity was 97.7 mg / g.

[0059] Comparative Example 1: Commercially available silica gel adsorbent, adsorption effect on hydrogen fluoride: purification rate 90.3%, adsorption capacity 52.8 mg / g.

[0060] Comparative Example 2: Unlike Example 5, the polyvinyl alcohol, activated carbon, and irradiated chitosan mixture and MoS2 powder were not ultrasonically treated together during preparation. The mixture was added to a mixture of 3 times the mass of isopropyl alcohol and water (mass ratio 1:5). After mixing thoroughly, the MoS2 was added and stirred for 20 minutes. The mixture was then left to stand at -25°C for 8 hours. The mixture was then dried, calcined at 250°C, ground, and formed to obtain an adsorbent. Testing of the adsorbent's hydrogen fluoride adsorption performance demonstrated a purification rate of 91.8% and an adsorption capacity of 87.2 mg / g.

[0061] Comparative Example 3: Different from Example 5, the adsorbent was placed at a low temperature of -5°C for 8 hours. The adsorption effect of the adsorbent on hydrogen fluoride was tested: the purification rate was 89.7%, and the adsorption capacity was 92.5 mg / g.

[0062] Comparative Example 4: Unlike Example 5, the polyvinyl alcohol, activated carbon, and irradiated chitosan mixture and MoS2 powder were not ultrasonically treated together during preparation. The mixture was added to a mixture of 3 times the mass of isopropyl alcohol and water (mass ratio 1:5). After mixing thoroughly, the MoS2 was added and stirred for 20 minutes. The mixture was then left to stand at -5°C for 8 hours. The mixture was then dried, calcined at 250°C, ground, and formed to obtain an adsorbent. Testing of the adsorbent's hydrogen fluoride adsorption performance demonstrated a purification rate of 80.1% and an adsorption capacity of 77.3 mg / g.

[0063] Comparative Example 5: The difference from Example 5 is that the irradiated modified chitosan is replaced with chitosan. The adsorption effect of the adsorbent on hydrogen fluoride was tested: the purification rate was 90.5%, and the adsorption capacity was 93.7 mg / g.

[0064] 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 they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A process for recovering oxygen from waste gas discharged from the production of organic fluoride, characterized in that: The following steps are involved: Step 1: The waste gas enters the Dewar tank (1) and first passes through the first-stage heat exchanger (2) to cool the waste gas to -65 to -68°C, and liquefy and remove ethanol and ether impurities in the waste gas; Step 2: The waste gas then enters the gas-liquid separation tank 1 (4) for gas-liquid separation; Step 3: The exhaust gas then enters the secondary heat exchanger (5), where it is cooled to -85 to -88°C to remove fluorine impurities in the exhaust gas. Step 4: The waste gas then enters the gas-liquid separation tank 2 (7) for gas-liquid separation. After separation, the gas is sent to the adsorption tank (6) filled with adsorbent to adsorb trace residual organic matter. The outlet gas is purified gas, which can reach the high-purity oxygen standard. The purified gas after adsorption passes through the secondary heat exchanger (5) and the primary heat exchanger (2) in turn for cold recovery and reheating to room temperature. Step 5: After the liquid oxygen enters the Dewar tank (1), it passes through the secondary heat exchanger (5) and the primary heat exchanger (2) in sequence to exchange heat and replenish the cooling capacity required for operation; Step 6: The purified gas is transported to the production link of organic fluoride through the product gas pipeline (8); The adsorbent comprises the following raw materials in parts by weight: 3 to 6 parts of MoS2 powder, 28 to 31 parts of polyvinyl alcohol, 50 to 55 parts of activated carbon, and 11 to 16 parts of irradiated modified chitosan. During preparation, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are evenly mixed, the mixture and MoS2 powder are ultrasonically treated together, the MoS2 is peeled off into two-dimensional MoS2 nanosheets, the polyvinyl alcohol, activated carbon, and irradiated modified chitosan are ultrasonically crushed into mixed nanoparticles, the mixed nanoparticles are added to a mixture of 2 to 3 times the mass of isopropanol and water, MoS2 is added after evenly mixing, stirring is continued for 20 to 30 minutes, the mixture is placed at a low temperature of -22 to -25°C and allowed to stand for 8 to 12 hours, and then dried, calcined at 250 to 260°C, ground, and formed to obtain the adsorbent. The adsorbent has an adsorption effect on hydrogen fluoride: a purification rate of 98.9 to 99.6%, and an adsorption capacity of 97.7 to 114.6 mg / g.

2. The process for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 1, characterized in that: In step 1, the primary heat exchanger (2) cools the exhaust gas to -68°C to remove ethanol and ether impurities in the exhaust gas.

3. The process for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 1, characterized in that: In step 3, the secondary heat exchanger (5) cools the exhaust gas to -88°C to remove fluorine impurities in the exhaust gas.

4. The process for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 1, characterized in that: In step 4, the liquefied organic matter solution collected in the gas-liquid separation tank 1 (4) and the gas-liquid separation tank 2 (7) is discharged and then processed uniformly.

5. The process for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 1, characterized in that: In step 6, the oxygen gasified in step 5 is connected to the purified gas and transported to the production link of organic fluoride through the product gas pipeline (8).

6. A device for recovering oxygen from waste gas discharged from the production of organic fluoride, characterized in that: The invention comprises a dewar tank (1), a primary heat exchanger (2), a gas-liquid separation tank (1) (4), a secondary heat exchanger (5), an adsorption tank (6) and a gas-liquid separation tank (2) (7); the primary heat exchanger (2), the gas-liquid separation tank (1) (4), the secondary heat exchanger (5), the adsorption tank (6) and the gas-liquid separation tank (2) (7) are all installed in the dewar tank (1); the waste gas pipeline (9) is connected to the dewar tank (1) and then connected to the primary heat exchanger (2), the gas-liquid separation tank (1) (4), the secondary heat exchanger (5), the gas-liquid separation tank (2) (7) and the adsorption tank (6) in sequence; the gas outlet of the adsorption tank (6) is connected to the secondary heat exchanger (5), the primary heat exchanger (2) and the product gas pipeline (8) outside the dewar tank (1) in sequence through a pipeline; the liquid oxygen pipeline (10) is connected to the dewar tank (1) and then connected to the secondary heat exchanger (5) and the primary heat exchanger (2) in sequence.

7. The device for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 6, characterized in that: A low-temperature valve (3) is connected between the first-stage heat exchanger (2) and the gas-liquid separation tank (4).

8. The device for recovering oxygen from waste gas discharged from the production of organic fluoride according to claim 6, characterized in that: A low-temperature valve (3) is connected between the secondary heat exchanger (5) and the second gas-liquid separation tank (7).

9. The device for recovering oxygen from waste gas discharged from the production of organic fluoride according to any one of claims 6 to 8, characterized in that: The bottoms of the gas-liquid separation tank 1 (4) and the gas-liquid separation tank 2 (7) are connected to the liquefied organic solution discharge pipeline; the liquid oxygen pipeline (10) is connected to the Dewar tank (1) and then connected to the secondary heat exchanger (5), the primary heat exchanger (2), and the product gas pipeline (8) outside the Dewar tank (1) in sequence.

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