Treatment system for organic sulfur-containing waste liquid

Abstract

The utility model provides a treatment system for organic sulfur-containing waste liquid. The system comprises a compatibility tank provided with a sodium carbonate solution inlet and an organic sulfur-containing waste liquid inlet, a supercritical oxidation reactor provided with an oxidant inlet and connected with the compatibility tank, and a salt conversion separation device provided with a potassium chloride inlet and connected with the supercritical oxidation reactor, the potassium sulfate solution storage tank and the sodium chloride solution storage tank are respectively connected with the salt conversion and separation device, the first mechanical vapor recompression device is connected with the potassium sulfate solution storage tank, the potassium sulfate separator is connected with the first mechanical vapor recompression device, and the second mechanical vapor recompression device is connected with the sodium chloride solution storage tank. And the sodium chloride separator is connected with the second mechanical vapor recompression device. Efficient decomposition of organic pollutants is achieved through the supercritical oxidation reactor, meanwhile, ion exchange is carried out in the salt conversion and separation device, potassium sulfate is generated, efficient recovery of the sulfur element can be achieved, and wastewater discharge reaches the standard.

Description

Technical Field

[0001] The present application relates to the field of environmental protection technology, and in particular to a treatment system for organic sulfur-containing waste liquid. Background Art

[0002] Existing technologies generate large quantities of organic sulfur wastewater from chemical industries such as oil refining, petrochemicals, pharmaceuticals, and leather tanning. These wastewaters are characterized by high COD, high biotoxicity, and resistance to degradation. Conventional disposal technologies, such as incineration, wet oxidation, and Fenton oxidation, are difficult to treat, often resulting in incomplete disposal and secondary pollution such as tail gas and solid waste.

[0003] Generally speaking, the conventional disposal technology for organic sulfur-containing waste liquid is incineration. However, during the incineration process, the sulfur in the organic sulfur-containing waste liquid will generate acidic substances, corrode equipment, and convert into pollutants such as SO2 and H2S, resulting in secondary tail gas pollution. Desulfurization treatment is required, which increases disposal costs. The desulfurization process also produces desulfurization waste liquid, which requires further disposal. In addition, when the calorific value of the organic sulfur-containing waste liquid is low, a large amount of auxiliary fuel must be added, which consumes a lot of energy. The incineration of organic waste liquid produces large tail gas emissions. Although the tail gas can meet emission standards after treatment, it still contains a variety of atmospheric pollutants and a large amount of carbon dioxide greenhouse gas. Utility Model Content

[0004] The technical problem to be solved by the present application is to provide a treatment system for organic sulfur-containing waste liquid, which can realize the efficient recovery of organic sulfur-containing waste liquid and obtain products with high economic value.

[0005] In order to solve the above problems, the present application discloses a treatment system for organic sulfur-containing waste liquid, which includes a mixing tank provided with an inlet for sodium carbonate solution and an inlet for organic sulfur-containing waste liquid, a supercritical oxidation reactor provided with an oxidant inlet and connected to the mixing tank, a salt conversion separation device provided with a potassium chloride inlet and connected to the supercritical oxidation reactor, a potassium sulfate solution storage tank and a sodium chloride solution storage tank respectively connected to the salt conversion separation device, a first mechanical vapor recompression device connected to the potassium sulfate solution storage tank, a potassium sulfate separator connected to the first mechanical vapor recompression device, a second mechanical vapor recompression device connected to the sodium chloride solution storage tank, and a sodium chloride separator connected to the second mechanical vapor recompression device.

[0006] Optionally, the salt conversion separation device includes a powered positive electrode and a powered negative electrode that are arranged opposite to each other, and also includes a plurality of cation exchange membranes and a plurality of anion exchange membranes that are alternately arranged between the powered positive electrode and the powered negative electrode.

[0007] Optionally, the sodium chloride solution storage tank and the second mechanical vapor recompression device are connected via a sodium chloride solution delivery pump.

[0008] Optionally, the system further comprises a high-pressure waste liquid delivery pump connected to the compatibility tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the supercritical oxidation reactor.

[0009] Optionally, the system further comprises a high-pressure oxidant delivery pump connected to the supercritical oxidation reactor.

[0010] Optionally, the system further comprises a gas-liquid separation device respectively connected to the supercritical oxidation reactor and the salt conversion separation device.

[0011] Optionally, the system further comprises a carbon dioxide recovery system connected to the gas-liquid separation device.

[0012] Optionally, the gas-liquid separation device is connected to the carbon dioxide recovery system via a condenser.

[0013] Optionally, the system further includes a pressure reducing valve group connected to the supercritical oxidation reactor and the gas-liquid separation device respectively.

[0014] Optionally, the gas-liquid separation device and the salt conversion separation device are connected via a pressure reducing valve group and a cooler.

[0015] Compared with the prior art, this application has the following advantages:

[0016] The treatment system for organic sulfur-containing waste liquid provided by the embodiment of the present application includes a mixing tank provided with an inlet for sodium carbonate solution and an inlet for organic sulfur-containing waste liquid, a supercritical oxidation reactor provided with an oxidant inlet and connected to the mixing tank, a salt conversion separation device provided with a potassium chloride inlet and connected to the supercritical oxidation reactor, a potassium sulfate solution storage tank and a sodium chloride solution storage tank respectively connected to the salt conversion separation device, a first mechanical vapor recompression device connected to the potassium sulfate solution storage tank, a potassium sulfate separator connected to the first mechanical vapor recompression device, a second mechanical vapor recompression device connected to the sodium chloride solution storage tank, and a sodium chloride separator connected to the second mechanical vapor recompression device. The treatment system for organic sulfur-containing waste liquid provided by the embodiment of the present application, through the mixing tank and the provision of a supercritical oxidation reactor for oxidation treatment, can convert the organic sulfur waste liquid into a less corrosive product, thereby avoiding corrosion of subsequent equipment. At the same time, the salt conversion separation device can conveniently obtain a product with economic value, and the mechanical vapor recompression device can further realize separation and extraction of the product and the solvent, thereby achieving harmlessness and resource utilization of the organic sulfur-containing waste liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of a system for treating organic sulfur waste liquid shown in an embodiment of the present application;

[0018] Figure 2 It is a schematic diagram of a salt conversion separation device shown in an embodiment of the present application.

[0019] Among them, L1-organic sulfur-containing waste liquid, L2-sodium carbonate solution, L3-potassium chloride solution, L4-distilled water, G1-oxidant, G2-carbon dioxide product, S1-potassium sulfate, S2-sodium chloride.

[0020] 1- compatibility tank, 2- high-pressure waste liquid delivery pump, 3- preheater, 4- supercritical oxidation reactor, 5- decompression system, 6- gas-liquid separation device, 7- cooler, 8- condenser, 9- carbon dioxide recovery system, 10- concentration device, 11- salt conversion separation device, 12- sodium chloride solution storage tank, 13- sodium chloride solution delivery pump, 14- second mechanical vapor recompression device, 15- sodium chloride separator, 16- potassium sulfate solution storage tank, 17- potassium sulfate solution delivery pump, 18- first mechanical vapor recompression device, 19- potassium sulfate separator, 20- potassium sulfate dryer, 21- sodium chloride dryer, 22- steam condenser, 23- high-pressure oxidant delivery pump, 24- decompression valve group;

[0021] 11-1-energized negative electrode, 11-2-energized positive electrode, 11-3-cation exchange membrane, 11-4-anion exchange membrane, 11-5-solution channel, 11-6-sodium chloride recovery chamber, 11-7-potassium sulfate recovery chamber. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0023] refer to Figure 1 , Figure 1 The schematic diagram of a treatment system for organic-sulfur waste liquid, as shown in an embodiment of the present application, includes a mixing tank 1 provided with inlets for a sodium carbonate solution and an organic-sulfur waste liquid, a supercritical oxidation reactor 4 provided with an oxidant inlet and connected to the mixing tank 1, a salt conversion and separation device 11 provided with an inlet for potassium chloride and connected to the supercritical oxidation reactor 4, a potassium sulfate solution storage tank and a sodium chloride solution storage tank 12, respectively connected to the salt conversion and separation device 11, a first mechanical vapor recompression device 18 connected to the potassium sulfate solution storage tank, a potassium sulfate separator 19 connected to the first mechanical vapor recompression device, a second mechanical vapor recompression device 14 connected to the sodium chloride solution storage tank 12, and a sodium chloride separator 15 connected to the second mechanical vapor recompression device 14.

[0024] Specifically, the mixing tank 1 can allow the sodium carbonate solution to flow in through the sodium carbonate solution inlet, and the organic sulfur-containing waste liquid can allow the organic sulfur-containing waste liquid to flow in through the organic sulfur-containing waste liquid inlet, so that the sodium carbonate solution and the organic sulfur-containing waste liquid can be mixed in the mixing tank 1.

[0025] The mixing tank 1 is used to determine the ratio between the sodium carbonate solution L2 and the organic sulfur-containing waste liquid L1 according to the sulfur content in the organic sulfur-containing waste liquid L1, and after mixing the organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 in proportion, pass them into the supercritical oxidation reactor 4;

[0026] Specifically, the ratio between the organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 can be calculated as follows:

[0027] Q S / Q Na2CO3 =32×C Na2CO3 / (106×C S )

[0028] Among them, Q S -Flow rate of waste liquid containing organic sulfur L1, m 3 / h;Q Na2CO3 - Flow rate of sodium carbonate solution L2, m 3 / h; C S -Sulfur concentration of organic sulfur waste liquid L1, g / L; C Na2CO3 -Sodium carbonate concentration, g / L.

[0029] Thereafter, the mixed sodium carbonate solution and organic sulfur-containing waste liquid can be transported to a supercritical oxidation reactor 4 equipped with an oxidant inlet. The supercritical oxidation reactor 4 can have a temperature-raising function, so that the oxidant, sodium carbonate solution, and organic sulfur-containing waste liquid introduced into the supercritical oxidation reactor 4 form a supercritical water environment, and undergo oxidative decomposition under a supercritical state, converting the carbon element in the organic sulfur into CO2, the hydrogen element into H2O, and the sulfur element into a sodium sulfate product.

[0030] The oxidant G1 may be oxygen, air, hydrogen peroxide, etc., and this application does not impose any limitation on this.

[0031] As an example of the present application, when the oxidant G1 is oxygen, the supercritical water oxidative decomposition reaction can be expressed as:

[0032] CcCyOzSn+O2+Na2CO3→CO2↑+0+Na,S04

[0033] The salt conversion separation device 11 is provided with a potassium chloride inlet, which can be fed with potassium chloride solution and sodium sulfate solution. Through the energized positive electrode and the energized negative electrode, as well as the alternating cation exchange membrane and the anion exchange membrane, the ions in the potassium chloride solution and the sodium sulfate solution can be migrated, thereby conveniently obtaining potassium sulfate solution and sodium chloride solution with economic value.

[0034] Thereafter, the potassium sulfate product and the sodium chloride product may be transported to the potassium sulfate solution storage tank 16 and the sodium chloride solution storage tank 12, respectively.

[0035] The potassium sulfate solution can be further transported to the first mechanical vapor recompression device 18 for refining treatment, and evaporated and crystallized by the first mechanical vapor recompression device 18. The liquid phase can then be transported to the potassium sulfate separator 19 connected to the first mechanical vapor recompression device 18 for solid-liquid separation, and the potassium sulfate can be further transported to the potassium sulfate dryer 20. After drying, the potassium sulfate product S1 is obtained.

[0036] For the sodium chloride solution, it can be transported to the second mechanical vapor recompression device 14 connected to the sodium chloride solution storage tank 12 for refining treatment, and then evaporated and crystallized by the second mechanical vapor recompression device 14. The liquid phase is then transported to the sodium chloride separator connected to the second mechanical vapor recompression device 14 for solid-liquid separation, and the sodium chloride is further transported to the sodium chloride dryer 21. After drying, a sodium chloride product S2 is obtained.

[0037] The gas phase evaporated from the first mechanical vapor recompression device 18 and the second mechanical vapor recompression device 14 can be cooled by the steam condenser 22 according to actual needs to obtain distilled water L4, which can be recycled later.

[0038] Therefore, through the treatment system for organic sulfur waste liquid provided in the embodiment of the present application, the organic sulfur waste liquid can be converted into a product with low corrosiveness through the combination tank 1 and the supercritical oxidation reactor 4 is provided for oxidation treatment, thereby avoiding corrosion of subsequent equipment. At the same time, the product with economic value can be conveniently obtained through the salt conversion separation device 11, and the product and the solvent can be further separated and extracted through the mechanical vapor recompression device, thereby realizing the harmlessness and resource utilization of the organic sulfur waste liquid.

[0039] In one embodiment of the present invention, the salt conversion separation device 11 includes a powered positive electrode and a powered negative electrode disposed opposite to each other, and also includes a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately disposed between the powered positive electrode and the powered negative electrode.

[0040] refer to Figure 2 , Figure 2Schematic diagram of a salt conversion separation device 11 shown in an embodiment of the present application. The salt conversion separation device 11 includes an electrically powered positive electrode 11-2 and an electrically powered negative electrode 11-1 disposed opposite each other, a plurality of cation exchange membranes 11-3 and anion exchange membranes 11-4 alternately disposed between the electrically powered positive electrode 11-2 and the electrically powered negative electrode 11-1, and at least one recovery chamber disposed between the cation exchange membrane 11-3 and the anion exchange membrane 11-4; the recovery chambers include a potassium sulfate recovery chamber 11-7 and a sodium chloride recovery chamber 11-6.

[0041] In a specific implementation, a gap may exist between the cation exchange membrane 11-3 and the anion exchange membrane 11-4, which can be used to pass a solution to form a solution channel. Different types of solutions may contain anions and cations, and electrode solution e may be added to the energized positive electrode 11-2 and the energized negative electrode 11-1. Under an energized environment, cations may begin to move toward the energized negative electrode 11-1 and migrate through the cation exchange membrane 11-3 to other solution channels, while anions may begin to move toward the energized positive electrode 11-2 and migrate through the anion exchange membrane 11-4 to other solution channels.

[0042] Thus, by reasonably setting the entry positions of the sodium sulfate solution and the potassium chloride solution L3, a sodium chloride recovery chamber 11-6 for recovering sodium chloride S2 and a potassium sulfate recovery chamber 11-7 for recovering potassium sulfate S1 can be formed in part of the solution channel.

[0043] Specifically, the solution channel 11-5 between the solution channel 11-5 for introducing the potassium chloride solution and the solution channel 11-5 for introducing the sodium sulfate solution can be used as the sodium chloride recovery chamber 11-6, the solution channel 11-5 for introducing the potassium chloride solution is located on the side close to the energized negative electrode 11-1, and the solution channel 11-5 for introducing the sodium sulfate solution is located on the side close to the energized positive electrode 11-2. An anion exchange membrane 11-4 is provided between the sodium chloride recovery chamber 11-6 and the solution channel 11-5 for introducing the potassium chloride solution, and a cation exchange membrane 11-3 is provided between the sodium chloride recovery chamber 11-6 and the solution channel 11-5 for introducing the sodium sulfate solution.

[0044] Water can be passed into the sodium chloride recovery chamber 11-6. Under an energized environment, the chloride ions in the potassium chloride solution move toward the energized positive electrode 11-2 and enter the sodium chloride recovery chamber 11-6 through the anion exchange membrane 11-4. The sodium ions in the sodium sulfate solution can move toward the energized negative electrode 11-1 and enter the sodium chloride recovery chamber 11-6 through the cation exchange membrane 11-3. In the sodium chloride recovery chamber 11-6, the side near the energized negative electrode 11-1 is the anion exchange membrane 11-4, and the side near the energized positive electrode 11-2 is the cation exchange membrane 11-3. As a result, after entering the sodium chloride recovery chamber 11-6, the chloride ions can be blocked by the cation exchange membrane 11-3 and cannot continue to move toward the energized positive electrode 11-2, and remain in the sodium chloride recovery chamber 11-6. After the sodium ions enter the sodium chloride recovery chamber 11-6, they can no longer move toward the energized negative electrode 11-1 due to the obstruction of the anion exchange membrane 11-4, and stay in the sodium chloride recovery chamber 11-6. Thus, the sodium ions and chloride ions can combine in the sodium chloride recovery chamber 11-6 to obtain a sodium chloride S2 solution.

[0045] At the same time, the solution channel 11-5 between the solution channel 11-5 for feeding the potassium chloride solution and the solution channel 11-5 for feeding the sodium sulfate solution can be used as a potassium sulfate recovery chamber 11-7, the solution channel 11-5 for feeding the potassium chloride solution is located close to the energized positive electrode 11-2, and the solution channel 11-5 for feeding the sodium sulfate solution is located close to the energized negative electrode 11-1. A cation exchange membrane 11-3 is provided between the potassium sulfate recovery chamber 11-7 and the solution channel 11-5 for feeding the potassium chloride solution, and an anion exchange membrane 11-4 is provided between the potassium sulfate recovery chamber 11-7 and the solution channel 11-5 for feeding the sodium sulfate solution.

[0046] Potassium sulfate recovery chamber 11-7 can be fed with water. Under an energized environment, the potassium ions in the potassium chloride solution can move toward the energized negative electrode 11-1 and enter the potassium sulfate recovery chamber 11-7 through the cation exchange membrane 11-3. The sulfate ions in the sodium sulfate solution can move toward the energized positive electrode 11-2 and enter the potassium sulfate recovery chamber 11-7 through the anion exchange membrane 11-4. In the potassium sulfate recovery chamber 11-7, one side near the energized negative electrode 11-1 is the anion exchange membrane 11-4, and one side near the energized positive electrode 11-2 is the cation exchange membrane 11-3. Thus, after entering the potassium sulfate recovery chamber 11-7, the sulfate ions can, due to the obstruction of the cation exchange membrane 11-3, be unable to continue to move toward the energized positive electrode 11-2 and remain in the potassium sulfate recovery chamber 11-7. After potassium ions enter the potassium sulfate recovery chamber 11-7, they can be blocked by the anion exchange membrane 11-4 and cannot continue to move toward the energized negative electrode 11-1, but stay in the potassium sulfate recovery chamber 11-7. Thus, potassium ions and sulfate ions can combine in the potassium sulfate recovery chamber 11-7 to obtain potassium sulfate S1 solution.

[0047] As for the solution channel 11-5 that passes through the potassium chloride solution, under an energized environment, the potassium ions therein move toward the energized negative electrode 11-1, migrate through the cation exchange membrane 11-3 to the potassium sulfate recovery chamber 11-7, while the chloride ions move toward the energized positive electrode 11-2, migrate through the anion exchange membrane 11-4 to the sodium chloride recovery chamber 11-6. As a result, the solution channel 11-5 of the potassium chloride solution can eventually discharge the desalted water.

[0048] In the solution channel 11-5 for the sodium sulfate solution, under an energized environment, the sodium ions therein migrate toward the energized negative electrode 11-1, pass through the cation exchange membrane 11-3, and migrate to the sodium chloride recovery chamber 11-6. The sulfate ions migrate toward the energized positive electrode 11-2, pass through the anion exchange membrane 11-4, and migrate to the potassium sulfate recovery chamber 11-7. Thus, the solution channel 11-5 for the sodium sulfate solution can eventually discharge desalted water.

[0049] The desalted water discharged from the solution channel 11 - 5 for introducing the sodium sulfate solution and the solution channel 11 - 5 for introducing the potassium chloride solution can be recycled to improve environmental protection.

[0050] In one embodiment of the present invention, the sodium chloride solution storage tank 12 and the second mechanical vapor recompression device 14 are specifically connected via a sodium chloride solution delivery pump 13 .

[0051] Specifically, a sodium chloride solution delivery pump 13 may be used to deliver sodium chloride solution between the sodium chloride solution storage tank 12 and the second mechanical vapor recompression device 14 , so that the sodium chloride solution can reach the infusion inlet of the second mechanical vapor recompression device 14 .

[0052] In one embodiment of the present invention, the potassium sulfate solution storage tank 16 and the first mechanical vapor recompression device 18 are specifically connected via a potassium sulfate solution delivery pump 17 .

[0053] Specifically, a potassium sulfate solution delivery pump 17 may be used to deliver potassium sulfate solution between the potassium sulfate solution storage tank 16 and the first mechanical vapor recompression device 18 , so that the potassium sulfate solution can reach the infusion inlet of the first mechanical vapor recompression device 18 .

[0054] In one embodiment of the present invention, the system further includes a high-pressure waste liquid delivery pump 2 connected to the mixing tank 1 and a preheater 3 connected to the high-pressure waste liquid delivery pump 2; the preheater 3 is also connected to the supercritical oxidation reactor 4.

[0055] Specifically, the high-pressure waste liquid delivery pump 22 is used to deliver the mixed organic sulfur-containing waste liquid L1 and sodium carbonate solution L2 to the preheater 3;

[0056] The preheater 3 is used to heat the mixed organic sulfur-containing waste liquid L1 and sodium carbonate solution L2 to a preset temperature and then transport them to the supercritical oxidation reactor 4.

[0057] Specifically, if a supercritical water environment is to be formed in the supercritical oxidation reactor 4, a relatively high temperature requirement is imposed on the supercritical oxidation reactor 4. Generally speaking, the solution system in the supercritical oxidation reactor 4 can be transformed into a supercritical state when the water temperature reaches above 374°C and the pressure reaches above 22.1 MPa.

[0058] In order to facilitate the formation of a supercritical water environment, the mixed organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 can be heated by a preheater 3. The preheater 3 can heat the mixed organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 to 200-300°C, and then pass the mixed organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 into the supercritical oxidation reactor 4.

[0059] In one embodiment of the present invention, the system further includes a high-pressure oxidant delivery pump 23 connected to the supercritical oxidation reactor 4 .

[0060] The high-pressure oxidant delivery pump 23 is used to pass the oxidant G1 into the supercritical oxidation reactor 4;

[0061] The supercritical oxidation reactor 4 is specifically used to pass the organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 into the supercritical oxidation reactor 4; after the organic sulfur-containing waste liquid L1 and the sodium carbonate solution L2 react with the oxidant G1 to produce an exothermic oxidation reaction, the temperature in the supercritical oxidation reactor 4 rises to form a supercritical environment, and the organic sulfur-containing waste liquid L1, the sodium carbonate solution L2, and the oxidant G1 undergo an oxidative decomposition reaction to obtain a potassium sulfate solution.

[0062] Specifically, in order to carry out the oxidative decomposition reaction in a supercritical water environment, a high-pressure oxidant delivery pump 23 can be used to introduce the oxidant G1 into the supercritical oxidation reactor 4. As a specific example of the present invention, the oxidant G1 can be liquid oxygen.

[0063] In supercritical oxidation reactor 4, the organic sulfur waste liquid L1 and sodium carbonate solution L2 react with oxidant G1 to produce an exothermic oxidation reaction. The temperature in supercritical oxidation reactor 4 rises to above 374°C, forming a supercritical water environment. In this environment, the organic sulfur waste liquid L1, sodium carbonate solution L2, and oxidant G1 undergo an oxidative decomposition reaction at a temperature of 550-650°C and a pressure of 22.1-24 MPa, producing a potassium sulfate solution.

[0064] In one embodiment of the present application, the system further comprises a concentrating device 10, which is connected to the oxidation reactor 4 and the salt conversion separation device 11 respectively;

[0065] The oxidation reactor 4 is specifically used to pass the sodium sulfate solution into the concentration device 10;

[0066] The concentrator 10 is used to concentrate the sodium sulfate solution and then pass the concentrated sodium sulfate solution into the salt conversion separation device 11.

[0067] Specifically, before the sodium sulfate solution is passed into the salt conversion separation device 11, it can be further cooled in the cooler 9 and then passed into the concentrator 10 for concentration treatment to improve the efficiency of the subsequent ion exchange process. The fresh water obtained after the concentration treatment can be used as cooling water for the oxidation reactor 4 for recycling.

[0068] In one embodiment of the present invention, the system further includes a gas-liquid separation device 6 connected to the supercritical oxidation reactor 4 and the salt conversion separation device 11 respectively.

[0069] Specifically, since the sodium sulfate solution output from the supercritical oxidation reactor 4 also contains carbon dioxide and the oxidant G1, the carbon dioxide and the oxidant G1 in the sodium sulfate solution can be separated by the gas-liquid separation device 6 before the sodium sulfate conversion.

[0070] The gas-liquid separation device 6 can separate the carbon dioxide and the oxidant G1 in the sodium sulfate solution by flash evaporation and pressure reduction.

[0071] In one embodiment of the present invention, the system further includes a carbon dioxide recovery system 9 connected to the gas-liquid separation device 6 .

[0072] Specifically, the gas-liquid separation device 6 may be connected to a carbon dioxide recovery system 9, which may be used to receive the carbon dioxide and the oxidant G1 discharged from the gas-liquid separation device 6 and separate the carbon dioxide and the oxidant G1 through pressure swing adsorption or distillation.

[0073] When using pressure swing adsorption, the adsorbent material selectively adsorbs carbon dioxide at gaseous pressure. The oxidant G1 and other impurities are not adsorbed and are discharged directly. Subsequently, the gaseous pressure is reduced, and the carbon dioxide adsorbed by the adsorbent material is desorbed, resulting in highly pure carbon dioxide G2 for recycling.

[0074] When distillation is used, the gas phase can be dried and dehydrated first, then cooled to -5 to -10°C to liquefy the gas phase and then enter the distillation unit. The unliquefied impurity gas is separated from the liquid carbon dioxide to obtain higher-purity carbon dioxide for recycling.

[0075] In one embodiment of the present invention, the gas-liquid separation device 6 and the carbon dioxide recovery system 9 are connected via a condenser 8 .

[0076] Specifically, a condenser 8 may be provided between the gas-liquid separation device 6 and the carbon dioxide recovery system 9, which may cool the gas phase with a relatively high temperature discharged from the gas-liquid separation device 6.

[0077] In one embodiment of the present invention, the system further includes a pressure reduction system 5 connected to the supercritical oxidation reactor 4 and the gas-liquid separation device 6 respectively.

[0078] Specifically, the product obtained by treatment in the supercritical oxidation reactor 4 can be a homogeneous phase in a supercritical state, and the homogeneous product can have a higher pressure. A pressure reducing valve group 24 can be set between the supercritical oxidation reactor 4 and the gas-liquid separation device 6 to reduce the pressure of the homogeneous product to avoid affecting the effect of subsequent gas-liquid separation.

[0079] In one embodiment of the present invention, the gas-liquid separation device 6 and the salt conversion separation device 11 are specifically connected via a pressure reducing valve group 24 and a cooler 7 .

[0080] Specifically, the gas-liquid separation device 6 and the salt conversion separation device 11 can be connected through a pressure reducing valve group 24 and a cooler 7 to reduce the pressure of the liquid phase separated by the gas-liquid separation device 6 and cool it to a temperature suitable for passing into the salt conversion separation device 11.

[0081] The above is a detailed introduction to a treatment system for organic sulfur waste liquid provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A system for treating organic sulfur waste liquid, characterized in that: The system includes a mixing tank provided with an inlet for sodium carbonate solution and an inlet for organic sulfur waste liquid, a supercritical oxidation reactor provided with an oxidant inlet and connected to the mixing tank, a salt conversion separation device provided with a potassium chloride inlet and connected to the supercritical oxidation reactor, a potassium sulfate solution storage tank and a sodium chloride solution storage tank respectively connected to the salt conversion separation device, a first mechanical vapor recompression device connected to the potassium sulfate solution storage tank, a potassium sulfate separator connected to the first mechanical vapor recompression device, a second mechanical vapor recompression device connected to the sodium chloride solution storage tank, and a sodium chloride separator connected to the second mechanical vapor recompression device.

2. The system for treating organic sulfur waste liquid according to claim 1, characterized in that: The salt conversion separation device includes a powered positive electrode and a powered negative electrode that are arranged opposite to each other, and also includes a plurality of cation exchange membranes and a plurality of anion exchange membranes that are alternately arranged between the powered positive electrode and the powered negative electrode.

3. The system for treating organic sulfur-containing wastewater according to claim 1, characterized in that: The sodium chloride solution storage tank and the second mechanical vapor recompression device are specifically connected via a sodium chloride solution delivery pump.

4. The system for treating organic sulfur-containing wastewater according to claim 1, wherein: The system further comprises a high-pressure waste liquid delivery pump connected to the compatibility tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the supercritical oxidation reactor.

5. The system for treating organic sulfur-containing wastewater according to claim 1, characterized in that: The system further comprises a high-pressure oxidant delivery pump connected to the supercritical oxidation reactor.

6. The system for treating organic sulfur-containing wastewater according to claim 1, characterized in that: The system further comprises a gas-liquid separation device connected to the supercritical oxidation reactor and the salt conversion separation device respectively.

7. The system for treating organic sulfur-containing waste liquid according to claim 6, characterized in that: The system further comprises a carbon dioxide recovery system connected to the gas-liquid separation device.

8. The system for treating organic sulfur-containing waste liquid according to claim 7, characterized in that: The gas-liquid separation device is connected to the carbon dioxide recovery system via a condenser.

9. The system for treating organic sulfur-containing waste liquid according to claim 6, characterized in that: The system further comprises a pressure reduction system connected to the supercritical oxidation reactor and the gas-liquid separation device respectively.

10. The system for treating organic sulfur-containing wastewater according to claim 6, characterized in that: The gas-liquid separation device is specifically connected to the salt conversion separation device via a pressure reducing valve group and a cooler.

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