An apparatus for the production of ethylene oxide co-product salicylic acid

Abstract

The utility model belongs to a kind of production device of ethylene oxide co-production salicylic acid;Including ethylene oxide synthesis unit, the import of ethylene oxide synthesis unit is connected with ethylene pipeline and pure oxygen pipeline respectively, ethylene oxide synthesis unit is connected with ethylene oxide storage tank, the exhaust outlet of ethylene oxide synthesis unit is connected with desulfurization and dealkylation unit, desulfurization and dealkylation unit is connected with carbon dioxide rectification unit, the product outlet of carbon dioxide rectification unit is connected with carboxylation unit, phenol sodium preparation unit import is connected with phenol delivery pipeline and liquid alkali pipeline, the outlet of phenol sodium preparation unit is connected with carboxylation unit, the outlet of carboxylation unit is connected with the first import of acid separation and post-processing unit, sulfuric acid pipeline is connected with the second import of acid separation and post-processing unit, the product outlet of acid separation and post-processing unit is connected with salicylic acid warehouse;With the advantage that the waste gas produced by producing ethylene oxide is used to produce salicylic acid, so as to reduce carbon emission of enterprise and improve enterprise benefit.

Description

Technical Field

[0001] This utility model belongs to the field of ethylene oxide production technology, specifically a production device for the co-production of ethylene oxide and salicylic acid. Background Technology

[0002] Ethylene oxide (EO) is the simplest cyclic ether, belonging to the heterocyclic class of compounds, and is an important petrochemical product. Its industrial production methods can be divided into two types: the chlorohydrin process and the direct oxidation of ethylene. The direct oxidation of ethylene is further divided into air oxidation and oxygen oxidation. The chlorohydrin process has been phased out both domestically and internationally due to its drawbacks such as small equipment size, low yield, poor quality, and high consumption. In contrast, the oxygen oxidation process has significant technological advantages over the air oxidation process in terms of production technology, equipment, product yield, and reaction conditions. Therefore, oxygen oxidation is currently the most common method used in EO plants worldwide to produce ethylene oxide.

[0003] The oxygen oxidation process involves the partial oxidation of ethylene on a silver-based catalyst to produce ethylene oxide. However, complete oxidation generates CO2, resulting in a large amount of CO2 waste gas being produced in ethylene oxide production plants. Consequently, ethylene oxide producers typically send the CO2 waste gas to an incinerator for combustion before venting. This treatment method not only wastes a significant amount of CO2 resources but also contributes to environmental problems such as climate change by emitting large amounts of CO2. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a production apparatus for the co-production of salicylic acid from ethylene oxide, thereby solving the technical problems existing in the prior art.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A production apparatus for co-producing salicylic acid from ethylene oxide includes an ethylene oxide synthesis unit. The inlet of the ethylene oxide synthesis unit is connected to an ethylene pipeline and a pure oxygen pipeline, respectively. The product outlet of the ethylene oxide synthesis unit is connected to an ethylene oxide storage tank. The waste gas outlet of the ethylene oxide synthesis unit is connected to a desulfurization and dehydrocarbonization unit. The outlet of the desulfurization and dehydrocarbonization unit is connected to a carbon dioxide distillation unit. The product outlet of the carbon dioxide distillation unit is connected to the first inlet of a carboxylation unit. The first inlet of a sodium phenolate preparation unit is connected to a phenol conveying pipeline. The second inlet of the sodium phenolate preparation unit is connected to a liquid alkali pipeline. The outlet of the sodium phenolate preparation unit is connected to the second inlet of the carboxylation unit. The outlet of the carboxylation unit is connected to the first inlet of an acid precipitation and post-treatment unit. A sulfuric acid pipeline is connected to the second inlet of the acid precipitation and post-treatment unit. The product outlet of the acid precipitation and post-treatment unit is connected to a salicylic acid warehouse.

[0007] The beneficial effects of this utility model are as follows: Based on the existing ethylene oxide production equipment, this utility model utilizes the waste gas produced from ethylene oxide production to couple with a carbon dioxide distillation unit to improve the purity of carbon dioxide. High-purity carbon dioxide is then used as a raw material to produce salicylic acid, thereby achieving the advantages of reducing corporate carbon emissions while improving corporate efficiency and protecting the environment.

[0008] Preferably, the tail gas outlet of the carbon dioxide distillation unit is connected to the tail gas treatment unit.

[0009] Preferably, the product outlet of the carbon dioxide distillation unit is connected to a high-purity carbon dioxide storage tank.

[0010] Preferably, the product outlet of the carbon dioxide distillation unit is also connected to a dry ice storage tank via a dry ice production unit.

[0011] Preferably, the product outlet of the carbon dioxide distillation unit and the liquid ammonia pipeline are respectively connected to the carbonation unit, the ammonium bicarbonate outlet of the carbonation unit is connected to the first inlet of the metathesis unit, the sodium sulfate aqueous solution outlet of the acid precipitation and post-treatment unit is connected to the second inlet of the metathesis unit, and the product outlet of the metathesis unit is connected to the sodium bicarbonate warehouse.

[0012] Preferably, the gas phase outlet of the metathesis unit is connected to the inlet of the carbonization unit.

[0013] Preferably, the waste liquid outlet of the metathesis unit is connected to the ammonia recovery unit, the gas phase outlet of the ammonia recovery unit is connected to the inlet of the carbonization unit, the liquid phase outlet of the ammonia recovery unit is connected to the MVR desalination evaporator, and the product outlet of the MVR desalination evaporator is connected to the ammonium sulfate warehouse.

[0014] Preferably, the mother liquor outlet of the MVR desalination evaporator is connected to the circulation inlet of the metathesis unit.

[0015] A production apparatus for the co-production of salicylic acid from ethylene oxide, manufactured according to the above technical solution, involves setting up an ethylene oxide synthesis unit for producing ethylene oxide. Simultaneously, the waste gas produced during ethylene oxide production is desulfurized and dehydrocarbonized in a desulfurization and dehydrocarbonization unit to remove sulfur-containing compounds and hydrocarbons before entering a carbon dioxide distillation unit. Low-temperature distillation technology is used to recover CO2 from the waste gas, yielding high-purity liquid CO2. This high-purity liquid CO2 can be sold directly as a product or used as a raw material to produce salicylic acid, sodium bicarbonate, ammonium sulfate, or dry ice. This process not only solves the problems of wasted CO2 resources and emissions but also allows for the production of various by-products, increasing the added value of the products. Furthermore, it allows for adjustments to product and output based on market conditions, leveraging the flexible adjustment capabilities of this invention to enhance enterprise competitiveness. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] In the diagram: 1. Ethylene oxide synthesis unit; 2. Ethylene pipeline; 3. Pure oxygen pipeline; 4. Ethylene oxide storage tank; 5. Desulfurization and dehydrocarbonization unit; 6. Carbon dioxide distillation unit; 7. Carboxylation unit; 8. Sodium phenolate preparation unit; 9. Phenol conveying pipeline; 10. Liquid alkali pipeline; 11. Acid precipitation and post-treatment unit; 12. Sulfuric acid pipeline; 13. Salicylic acid warehouse; 14. Tail gas treatment unit; 15. High-purity carbon dioxide storage tank; 16. Dry ice production unit; 17. Dry ice storage tank; 18. Carbonization unit; 19. Metathesis unit; 20. Sodium bicarbonate warehouse; 21. Ammonia recovery unit; 22. MVR desalination evaporator; 23. Ammonium sulfate warehouse; 24. Liquid ammonia pipeline; 25. Tail gas venting pipeline. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0020] The following is in conjunction with the appendix Figure 1This application provides a further detailed description of a production apparatus for the co-production of salicylic acid from ethylene oxide. The apparatus includes an ethylene oxide synthesis unit 1, whose inlet is connected to an ethylene pipeline 2 and a pure oxygen pipeline 3. The product outlet of the ethylene oxide synthesis unit 1 is connected to an ethylene oxide storage tank 4. The waste gas outlet of the ethylene oxide synthesis unit 1 is connected to a desulfurization and dehydrocarbonization unit 5. The outlet of the desulfurization and dehydrocarbonization unit 5 is connected to a carbon dioxide distillation unit 6. The product outlet of the carbon dioxide distillation unit 6 is connected to the first inlet of a carboxylation unit 7. The first inlet of a sodium phenolate preparation unit 8 is connected to a phenol conveying pipeline 9. The second inlet of the sodium phenolate preparation unit 8 is connected to a liquid alkali pipeline 10. The outlet of the sodium phenolate preparation unit 8 is connected to the second inlet of the carboxylation unit 7. The outlet of the carboxylation unit 7 is connected to the first inlet of an acid precipitation and post-treatment unit 11. A sulfuric acid pipeline 12 is connected to the second inlet of the acid precipitation and post-treatment unit 11. The product outlet of the acid precipitation and post-treatment unit 11 is connected to a salicylic acid warehouse 13.

[0021] Furthermore, the tail gas outlet of the carbon dioxide distillation unit 6 is connected to the tail gas treatment unit 14.

[0022] Furthermore, the product outlet of the carbon dioxide distillation unit 6 is connected to the high-purity carbon dioxide storage tank 15.

[0023] Furthermore, the product outlet of the carbon dioxide distillation unit 6 is also connected to the dry ice storage tank 17 via the dry ice production unit 16.

[0024] Furthermore, the product outlet of the carbon dioxide distillation unit 6 and the liquid ammonia pipeline 24 are respectively connected to the carbonation unit 18, the ammonium bicarbonate outlet of the carbonation unit 18 is connected to the first inlet of the metathesis unit 19, the sodium sulfate aqueous solution outlet of the acid precipitation and post-treatment unit 11 is connected to the second inlet of the metathesis unit 19, and the product outlet of the metathesis unit 19 is connected to the sodium bicarbonate warehouse 20.

[0025] Furthermore, the gas phase outlet of the metathesis unit 19 is connected to the inlet of the carbonization unit 18.

[0026] Furthermore, the waste liquid outlet of the metathesis unit 19 is connected to the ammonia recovery unit 21, the gas phase outlet of the ammonia recovery unit 21 is connected to the inlet of the carbonization unit 18, the liquid phase outlet of the ammonia recovery unit 21 is connected to the MVR desalination evaporator 22, and the product outlet of the MVR desalination evaporator 22 is connected to the ammonium sulfate warehouse 23.

[0027] Furthermore, the mother liquor outlet of the MVR desalination evaporator 22 is connected to the circulation inlet of the metathesis unit 19.

[0028] The working principle of this invention is as follows: This invention uses conventional methods to produce high-purity liquid CO2 and dry ice, so the production principle will not be elaborated further. The production principle of salicylic acid is as follows:

[0029] (1) The reaction process of sodium phenolate in Unit 8 is as follows:

[0030]

[0031] (2) The reaction process in carboxylation unit 7 is as follows:

[0032]

[0033] (3) The reaction process in acid precipitation and post-treatment unit 11 is as follows:

[0034]

[0035] (4) The reaction process in the double displacement unit 19 is as follows:

[0036] 2NH4HCO3+Na2SO4→2NaHCO3+(NH4)2SO4

[0037] (5) The reaction process in ammonia recovery unit 21 is as follows:

[0038] NH4HCO3→NH3+CO2+H2O

[0039] (6) The reaction process in carbonization unit 18 is as follows:

[0040] NH3·H2O + CO2 → NH4HCO3

[0041] The general process is as follows: Ethylene from ethylene pipeline 2 and pure oxygen from pure oxygen pipeline 3 enter ethylene oxide synthesis unit 1 together. After an incomplete oxidation reaction on a silver-based catalyst, ethylene oxide and CO2 are obtained. Ethylene oxide is obtained through distillation and enters ethylene oxide storage tank 4 through the product outlet of ethylene oxide synthesis unit 1. The aforementioned CO2 waste gas is sent to carbon dioxide distillation unit 6 for low-temperature distillation after desulfurization and dehydrocarbonization unit 5. After purification, high-purity liquid CO2 is obtained. The waste gas produced by carbon dioxide distillation unit 6 is treated through tail gas treatment unit 14. The high-purity liquid CO2 can be stored in high-purity carbon dioxide storage tank 15 and sold externally, or it can enter dry ice production unit 16 to produce dry ice. The dry ice can be stored in dry ice storage tank 17 and sold externally. Phenol from phenol conveying pipeline 9 and liquid alkali with a concentration of 40-50% from liquid alkali pipeline 10 enter sodium phenolate preparation unit 8 to synthesize sodium phenolate. Sodium phenolate reacts with the carbon dioxide distillation product. The high-purity liquid CO2 produced in Unit 6 enters the carboxylation unit 7 for carboxylation and secondary carboxylation to synthesize sodium salicylate. Then, it enters the acid precipitation and post-treatment unit 11 along with sulfuric acid from sulfuric acid pipeline 12. After acid precipitation, centrifugation, and drying, sodium salicylate yields salicylic acid as a product and sodium sulfate as a byproduct. The salicylic acid is sent to the salicylic acid warehouse 13 for storage. The ammonium bicarbonate in carbonation unit 18 and the aforementioned sodium sulfate enter the metathesis unit 19 for a metathesis reaction to produce sodium bicarbonate and ammonium sulfate. Sodium bicarbonate is sent to the sodium bicarbonate warehouse 20 as a product. The centrifuged mother liquor rich in ammonium bicarbonate and ammonium sulfate enters the ammonia recovery unit 21. After pyrolysis, the ammonium bicarbonate is decomposed into CO2 and NH3, and then concentrated and dried to obtain the ammonium sulfate product. The mixed gas of CO2 and NH3 after pyrolysis is recycled to the carbonation unit and, together with CO2 from carbon dioxide distillation unit 6 and liquid ammonia from liquid ammonia pipeline 24, is used to resynthesize ammonium bicarbonate.

[0042] Specifically, the detailed process of this utility model is as follows: Step 1: Ethylene from ethylene pipeline 2 and pure oxygen from pure oxygen pipeline 3 enter ethylene oxide synthesis unit 1 together, where an incomplete oxidation reaction occurs on a silver-based catalyst to obtain ethylene oxide and CO2 waste gas. The ethylene oxide synthesis unit 1 includes, but is not limited to, an EO reactor, an EO absorption tower, an EO stripping tower, an EO refining tower, a CO2 absorption tower, a CO2 regeneration tower, and a circulating gas compressor. These are conventional equipment that can be purchased directly from the market, and therefore will not be described in detail. The EO synthesis reaction temperature in the ethylene oxide synthesis unit 1 is approximately 220–270°C, and the reaction pressure is approximately 1.5–2.0 MPaG. Step Two: After the CO2 waste gas from Step One enters the desulfurization and dehydrocarbonization unit 5, it is first compressed and pressurized before entering the desulfurization tower for coarse desulfurization and fine desulfurization in sequence. The desulfurized CO2 waste gas is preheated and then sent to the dehydrocarbonization tower. In the dehydrocarbonization tower, the methane, olefins, and ethylene oxide components in the CO2 waste gas react with the O2 in the CO2 waste gas under the action of a catalyst to generate CO2 and H2O. The desulfurized and dehydrocarbonized CO2 waste gas is then sent to the carbon dioxide distillation unit 6 after heat recovery. The desulfurization and dehydrocarbonization unit 5 includes, but is not limited to, equipment such as a CO2 compressor, desulfurization tower, dehydrocarbonization tower, preheater, and electric heater. The above equipment is conventional equipment that can be purchased directly from the market, so it will not be described in detail. Step 3: The CO2 waste gas after desulfurization and dehydrocarbonization undergoes pre-cooling, drying, and adsorption filtration processes in the carbon dioxide distillation unit 6 before entering the liquefaction unit for liquefaction. The liquefied CO2 then enters the distillation column for further distillation, removing impurities such as N2 and CH4 from the raw gas to obtain high-purity liquid CO2 with a purity of 99.99%. This high-purity liquid CO2 can be sent to the high-purity carbon dioxide storage tank 15, the dry ice production unit 16, the carboxylation unit 7, and the carbonization unit 18. The CO2 distillation unit includes, but is not limited to, equipment such as a drying tower, dust filter, heater, liquefaction unit, subcooler, and distillation column; these are conventional equipment that can be purchased directly from the market and will not be described in detail here. Step 4: The high-purity liquid CO2 from the carbon dioxide distillation unit 6 is used to produce dry ice through the dry ice production unit 16. The produced dry ice is then stored in the dry ice storage tank 17. The dry ice production unit 16 includes, but is not limited to, equipment such as granular dry ice machines and block dry ice machines; these are conventional equipment that can be purchased directly from the market, and therefore will not be described in detail. Step 5: Phenol from the phenol conveying pipeline 9 and liquid alkali with a concentration of 40-50% from the liquid alkali pipeline 10 enter the sodium phenolate preparation unit 8. Sodium phenolate is synthesized in the preparation kettle under normal temperature and pressure conditions. The prepared sodium phenolate solution is concentrated under normal pressure and then directly sent to the carboxylation unit 7; the carboxylation unit 7 includes, but is not limited to, equipment such as a preparation kettle, a drying heater, a compressor, and an extraction kettle; these are conventional equipment that can be purchased directly from the market, and therefore will not be described in detail.Step Six: After metering, the sodium phenolate solution is added to the carboxylation reactor of carboxylation unit 7 and concentrated under reduced pressure. Then, high-purity CO2 from carbon dioxide distillation unit 6 is introduced to carry out the carboxylation reaction at a temperature of approximately 180–220°C and a pressure of approximately 5–8 MPa. After 1–3 hours of the above reaction, the pressure is released and the temperature is lowered, followed by concentration under reduced pressure. High-purity CO2 is then introduced again for a secondary carboxylation reaction. After the reaction is complete, the pressure is released and the temperature is lowered to obtain an aqueous solution of sodium salicylate. The carboxylation unit includes, but is not limited to, equipment such as a carboxylation reactor, vacuum pump, condenser, vacuum buffer tank, metering tank, and compressor. These are conventional equipment and can be purchased directly from the market, so they will not be described in detail. Step Seven: The aqueous solution of sodium salicylate from carboxylation unit 7 and dilute sulfuric acid from sulfuric acid pipeline 12 are added together to the acid precipitation reactor of acid precipitation and post-treatment unit 11. An acid precipitation reaction is carried out under normal temperature and pressure conditions to generate salicylic acid. The reaction solution is centrifuged and dried to obtain crude salicylic acid and centrifuged mother liquor. The crude salicylic acid is dried and then directly fed into a sublimation reactor for sublimation purification. After sublimation, the sublimed material is pumped to a crystallization tower for condensation using a vacuum pump to obtain a salicylic acid product with a purity greater than 99%. The centrifugal mother liquor is adsorbed and removed from the residual raw material phenol in a resin tower to obtain a sodium sulfate aqueous solution. The acid precipitation and post-treatment unit 11 includes, but is not limited to, equipment such as centrifuges, vacuum pumps, crystallization towers, sublimation reactors, and resin towers; the above equipment is conventional equipment and can be purchased directly from the market, so it will not be described in detail. Step 8: The sodium sulfate aqueous solution from the acid precipitation and post-treatment unit 11 and the excess ammonium bicarbonate from the carbonization unit 18 are sent together to the metathesis reactor in the metathesis unit 19 for metathesis reaction. The reaction temperature is about 30-40°C. After the reaction is complete, the reaction mixture is sent to the metathesis filter for separation. The filter cake obtained after separation is washed to obtain the product sodium bicarbonate. The filtrate obtained after separation is mixed with the washing liquid of the filter cake and sent to the ammonia recovery unit 21. The mixed gas generated during the production process of the metathesis unit 19 mainly consists of CO2 and NH3. After collection, it is sent to the carbonization unit 18 for recycling. The metathesis unit 19 includes, but is not limited to, equipment such as a metathesis reactor and a metathesis filter. Step 9: The filtrate from the metathesis unit 19 mainly consists of unreacted ammonium bicarbonate and the reacted ammonium sulfate. It is sent to the deammoniation reactor of the ammonia recovery unit 21. Under normal pressure and heating conditions (50-80℃), the ammonium bicarbonate in the filtrate decomposes into CO2 and NH3. The decomposed gas is sent to the carbonization unit 18 by a centrifugal fan. The remaining filtrate is sent to the MVR desalination evaporator 22 for treatment to obtain the product ammonium sulfate. The desalination mother liquor after removing ammonium sulfate is returned to the metathesis unit 19 for recycling. The ammonia recovery unit 21 includes, but is not limited to, equipment such as a deammoniation reactor, a centrifugal fan, and a filter. The above equipment is conventional equipment that can be purchased directly from the market, so it will not be described in detail.Step 10: Liquid ammonia from liquid ammonia pipeline 24, along with a mixture of NH3 and CO2 from the metathesis unit 19 and ammonia recovery unit 21, is sent to the ammonia absorption tower in carbonization unit 18 to obtain ammonia water. The resulting ammonia water is then sent to the carbonization tower to react with high-purity CO2 from carbon dioxide distillation unit 6 at room temperature and a pressure of 0.4–0.8 MPa to produce ammonium bicarbonate. A small amount of tail gas generated by the ammonia absorption tower and the carbonization tower is sent to the tail gas absorption tower for treatment before being vented. The ammonium bicarbonate aqueous solution obtained at the bottom of the carbonization tower is filtered by a centrifuge to obtain ammonium bicarbonate, which is then sent to the metathesis unit 19. The mother liquor from the centrifugation is recycled back to the ammonia absorption tower. The carbonization unit 18 includes, but is not limited to, equipment such as an ammonia absorption tower, a carbonization tower, a tail gas scrubbing tower, an ammonia water pump, and a centrifuge; these are conventional equipment that can be purchased directly from the market, and therefore will not be described in detail. This invention recovers and treats CO2 waste gas from ethylene oxide production through desulfurization, dehydrocarbonization, and low-temperature distillation to obtain high-purity liquid CO2, and co-produces salicylic acid, sodium bicarbonate, ammonium sulfate, and dry ice. This process boasts advantages such as simple and rational overall design, tight coupling and connection, short process flow, and high product added value. This method enhances the enterprise's ability to flexibly adjust downstream products while also improving its economic efficiency.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A production apparatus for the co-production of salicylic acid from ethylene oxide, comprising an ethylene oxide synthesis unit (1), wherein the inlet of the ethylene oxide synthesis unit (1) is connected to an ethylene pipeline (2) and a pure oxygen pipeline (3), characterized in that: The product outlet of the ethylene oxide synthesis unit (1) is connected to the ethylene oxide storage tank (4), the waste gas outlet of the ethylene oxide synthesis unit (1) is connected to the desulfurization and dehydrocarbonization unit (5), the outlet of the desulfurization and dehydrocarbonization unit (5) is connected to the carbon dioxide distillation unit (6), the product outlet of the carbon dioxide distillation unit (6) is connected to the first inlet of the carboxylation unit (7), the first inlet of the sodium phenolate preparation unit (8) is connected to the phenol conveying pipeline (9), the second inlet of the sodium phenolate preparation unit (8) is connected to the liquid alkali pipeline (10), the outlet of the sodium phenolate preparation unit (8) is connected to the second inlet of the carboxylation unit (7), the outlet of the carboxylation unit (7) is connected to the first inlet of the acid precipitation and post-treatment unit (11), the sulfuric acid pipeline (12) is connected to the second inlet of the acid precipitation and post-treatment unit (11), and the product outlet of the acid precipitation and post-treatment unit (11) is connected to the salicylic acid warehouse (13).

2. The production apparatus for co-producing salicylic acid from ethylene oxide according to claim 1, characterized in that: The tail gas outlet of the carbon dioxide distillation unit (6) is connected to the tail gas treatment unit (14).

3. A production apparatus for the co-production of salicylic acid from ethylene oxide according to claim 1 or 2, characterized in that: The product outlet of the carbon dioxide distillation unit (6) is connected to the high-purity carbon dioxide storage tank (15).

4. A production apparatus for the co-production of ethylene oxide and salicylic acid according to claim 3, characterized in that: The product outlet of the carbon dioxide distillation unit (6) is also connected to the dry ice storage tank (17) via the dry ice production unit (16).

5. A production apparatus for the co-production of salicylic acid from ethylene oxide according to claim 4, characterized in that: The product outlet of the carbon dioxide distillation unit (6) and the liquid ammonia pipeline (24) are connected to the carbonation unit (18), the ammonium bicarbonate outlet of the carbonation unit (18) is connected to the first inlet of the metathesis unit (19), the sodium sulfate aqueous solution outlet of the acid precipitation and post-treatment unit (11) is connected to the second inlet of the metathesis unit (19), and the product outlet of the metathesis unit (19) is connected to the sodium bicarbonate warehouse (20).

6. A production apparatus for the co-production of salicylic acid from ethylene oxide according to claim 5, characterized in that: The gas phase outlet of the metathesis unit (19) is connected to the inlet of the carbonization unit (18), and the gas phase outlet of the carbonization unit (18) is connected to the exhaust gas venting pipe (25).

7. A production apparatus for the co-production of salicylic acid from ethylene oxide according to claim 5, characterized in that: The waste liquid outlet of the metathesis unit (19) is connected to the ammonia recovery unit (21), the gas phase outlet of the ammonia recovery unit (21) is connected to the inlet of the carbonization unit (18), the liquid phase outlet of the ammonia recovery unit (21) is connected to the MVR desalination evaporator (22), and the product outlet of the MVR desalination evaporator (22) is connected to the ammonium sulfate warehouse (23).

8. A production apparatus for the co-production of salicylic acid from ethylene oxide according to claim 7, characterized in that: The mother liquor outlet of the MVR desalination evaporator (22) is connected to the circulation inlet of the metathesis unit (19).

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