Petrochemical heavy salt water zero discharge device

Abstract

The utility model discloses a petrochemical high-salt water zero discharge device, which belongs to the technical field of water treatment and comprises a pretreatment unit, a salt separation unit and a salt water separation unit which are sequentially connected. The pretreatment unit is a unit for softening and filtering incoming water; the salt separation unit is used for separating a NaCl solution and a Na2SO4 solution from incoming water; and the saline water separation unit is a unit for concentrating and crystallizing a NaCl solution and a Na2SO4 solution. The petrochemical high-salt water zero discharge device provided by the utility model is stable in process operation and free of hazardous waste, and resource recycling is realized as far as possible.

Description

Technical Field

[0001] The utility model belongs to the technical field of water treatment and relates to a water treatment device, in particular to a petrochemical high-salt water zero-discharge device. Background Art

[0002] A large amount of water resources need to be supplemented during the process of oil and gas extraction and petroleum refining. Due to the complex composition of crude oil, the extraction process, refining process and processing technology have become increasingly refined, resulting in the increasingly complex composition of associated wastewater pollution.

[0003] Petroleum and petrochemical wastewater mainly includes oil and gas field wastewater and refinery chemical wastewater. In the process of refinery chemical production, due to different production processes, refinery wastewater is usually divided into oily wastewater and salty wastewater for treatment. Salty wastewater contains a certain amount of suspended matter, but the particles are small and the turbidity is low. The scale-forming ions in the water are Ca 2+ Mg 2+ , HCO 3- 、SO4 2- The content is high, the concentration of organic matter is high, and the water quality and water volume fluctuate greatly. Desalination treatment can realize the resource utilization of fresh water. The concentrated brine produced by the desalination process can achieve near-zero emissions through further solidification treatment, while realizing the recycling of soluble solids.

[0004] The petrochemical industry is a high-energy-consuming industry that produces a large amount of high-salt wastewater every year. If it is discharged directly into the environment, it will cause serious damage to the ecological environment. With the improvement of emission standards, companies have begun to treat high-salt wastewater and realize resource reuse as much as possible. The core process of traditional high-salt wastewater zero-discharge treatment is a combination of membrane concentration and evaporation crystallization. Its by-product crystalline salt appears in a mixed form and contains a variety of ions. The degree of resource utilization is not high. In the end, it can only be landfilled as hazardous waste. The cost of treating a ton of salt is as high as more than 3,000 yuan. Therefore, mixed salt crystallization is currently a bottleneck problem that hinders the realization of zero discharge of high-salt wastewater. It is very important to explore feasible by-product resource utilization processes. Utility Model Content

[0005] In view of the defects of the prior art, the utility model provides a petrochemical high-salt water zero-discharge device, which solves the problem of mixed salt crystallization, thereby realizing the recycling of waste salt and achieving the purpose of zero wastewater discharge, and can be used for the treatment of high-salt organic wastewater in the petrochemical industry.

[0006] To achieve the above-mentioned purpose, the utility model provides a petrochemical high-salt water zero-discharge device, which has the following characteristics: it comprises a pretreatment unit, a salt separation unit and a salt water separation unit connected in sequence; the pretreatment unit is a unit for softening and filtering water in the future; the salt separation unit is a unit for separating NaCl solution and Na2SO4 solution from water in the future; the salt water separation unit is a unit for concentrating and crystallizing NaCl solution and Na2SO4 solution.

[0007] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the pretreatment unit includes a softening clarification tank, a self-cleaning filter and a softening membrane connected in sequence; the water production outlet of the softening membrane is connected to the water inlet of the salt separation unit.

[0008] Furthermore, the utility model provides a petrochemical high-salt water zero-discharge device, which may also have the following characteristics: wherein the pretreatment unit also includes a pH adjustment tank; the water outlet of the pH adjustment tank is connected to the water inlet of the softening and clarification tank.

[0009] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the pretreatment unit also includes a softening water tank; the water production outlet of the softening membrane is connected to the softening water tank, and the softening water tank is further connected to the water inlet of the salt separation unit.

[0010] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the salt separation unit includes a high-valent ion retention device; the water outlet of the pretreatment unit is connected to the water inlet of the high-valent ion retention device, and the water production outlet and the concentrated water outlet of the high-valent ion retention device are both connected to the brine separation unit.

[0011] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the salt separation unit also includes a high-valent ion water inlet pump; the water outlet of the pretreatment unit is connected to the water inlet of the high-valent ion interception device through the high-valent ion water inlet pump.

[0012] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the salt separation unit also includes a water production tank and a concentrated water tank; the water production outlet of the high-valent ion interception device is connected to the water production tank, and the water production tank is further connected to the brine separation unit; the concentrated water outlet of the high-valent ion interception device is connected to the concentrated water tank, and the concentrated water tank is further connected to the brine separation unit.

[0013] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the brine separation unit includes a monovalent salt retention device at the water production end, an MVR evaporation crystallization device, an electrochemical oxidation device, a monovalent salt retention device at the concentrate water end, and a freezing crystallization device; the water production outlet of the high-valent ion retention device is connected to the water inlet of the monovalent salt retention device at the water production end, and the concentrated water outlet of the monovalent salt retention device at the water production end is connected to the MVR evaporation crystallization device; the concentrated water outlet of the high-valent ion retention device is connected to the water inlet of the electrochemical oxidation device, the water outlet of the electrochemical oxidation device is connected to the water inlet of the monovalent salt retention device at the concentrate water end, and the concentrated water outlet of the monovalent salt retention device at the concentrate water end is connected to the freezing crystallization device.

[0014] Furthermore, the utility model provides a petrochemical high-salt water zero emission device, which may also have the following characteristics: wherein the brine separation unit also includes a produced water inlet pump and a concentrated water inlet pump; the salt separation unit is connected to the monovalent salt interception device at the produced water end through the produced water inlet pump; the salt separation unit is connected to the electrochemical oxidation device through the concentrated water inlet pump.

[0015] Furthermore, the utility model provides a petrochemical high-salt water zero discharge device, which may also have the following characteristics: wherein the brine separation unit also includes a reuse water tank; the water production outlets of the monovalent salt retention device at the water production end and the monovalent salt retention device at the concentrate water end are both connected to the reuse water tank, and the condensed water outlet of the MVR evaporation crystallization device is also connected to the reuse water tank.

[0016] The beneficial effects of the utility model are: the utility model realizes zero discharge of petrochemical high-salt water, and optimizes the traditional membrane concentration and evaporation crystallization combined process. In view of the fact that the by-products of the existing process are all mixed salts and cannot be used as resources, the double membrane system is used to reduce the concentrated liquid, which can not only separate the by-product salts and realize resource reuse as much as possible; it can also further reduce the concentrated liquid output, so that the subsequent concentrated liquid evaporation crystallization cost is also reduced. The specific beneficial effects include the following:

[0017] 1. The petrochemical high-salt water zero-discharge device provided by the utility model replaces the existing membrane concentration and evaporation crystallization combined process, does not produce external hazardous waste, and performs salt separation on the by-products. The obtained by-product crystalline salt can be recycled, solving the problem that mixed salt crystals in high-salt wastewater zero-discharge projects are difficult to recycle.

[0018] 2. The petrochemical high-salt water zero-discharge device provided by the utility model adopts an ion interception device to reduce the concentrated liquid before evaporation and crystallization, which greatly reduces the treatment amount of the concentrated liquid entering the evaporation and crystallization system and effectively reduces the operating cost of evaporation and crystallization.

[0019] 3. The petrochemical high-salt water zero-discharge device provided by the utility model also separates the brine from the concentrated liquid produced by the salt separation unit, and in order to meet the technical requirements of industrial salt, the impure salt at the concentrated water end is subjected to electrochemical oxidation pretreatment combined with a salt interception device, which greatly improves the whiteness of the sulfate and realizes resource reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a petrochemical high-salt water zero discharge device;

[0021] Figure 2 is a schematic diagram of a preprocessing unit;

[0022] Figure 3 is a schematic diagram of the salt separation unit;

[0023] Figure 4 is a schematic diagram of a brine separation unit;

[0024] In the figure: 1. Pretreatment unit; 2. Salt separation unit; 3. Brine separation unit; 101. Adjustment tank; 102. Softening and clarification tank; 103. Self-cleaning filter; 104. Special softening membrane; 105. Softening water tank; 201. High-valent ion interception device; 301. Monovalent salt interception device at the water production end; 302. Monovalent salt interception device at the concentrate end; 303. MVR evaporation crystallization device; 304. Electrochemical oxidation device; 305. Freezing crystallization device; 306. Recycled water tank. DETAILED DESCRIPTION

[0025] The specific implementation of the present utility model is described below with reference to the accompanying drawings.

[0026] like Figure 1 As shown, the utility model provides a petrochemical high-salt water zero-discharge device, comprising a pretreatment unit 1, a salt separation unit 2 and a salt separation unit 3 connected in sequence, that is, the water outlet of the treatment unit is connected to the water inlet of the salt separation unit 2, and the water outlet of the salt separation unit 2 is connected to the water inlet of the salt separation unit 3. The pretreatment unit 1 is a unit for softening and filtering the future water. The salt separation unit 2 is a unit for separating the future water into NaCl solution and Na2SO4 solution. The salt separation unit 3 is a unit for concentrating and crystallizing the NaCl solution and the Na2SO4 solution.

[0027] In a specific embodiment, the pretreatment unit 1 includes a softening clarification tank 102, a self-cleaning filter 103 and a softening membrane 104 connected in sequence. The water outlet of the softening membrane 104 is connected to the water inlet of the salt separation unit 2 (high-valent ion interception device 201). The pretreatment unit 1 uses a combined process of softening and dosing and filtering with the softening membrane 104 to remove large particle impurities and Ca in the water. 2+ Mg 2+ .

[0028] In a preferred embodiment, the pretreatment unit 1 further comprises a pH adjustment tank 101. The water outlet of the pH adjustment tank 101 is connected to the water inlet of the softening and clarifying tank 102. The incoming water first adjusts the pH in the pH adjustment tank 101 and then enters the softening and clarifying tank 102 to precipitate Ca 2+ Mg 2+ .

[0029] In a preferred embodiment, the pretreatment unit 1 further comprises a softening water tank 105. The water outlet of the softening membrane 104 is connected to the softening water tank 105, and the softening water tank 105 is further connected to the water inlet of the salt separation unit 2 (high-valent ion interception device 201).

[0030] Specifically, the pH adjustment tank 101 is provided with a pH adjustment device interface and a matching pH meter to control the pH of the incoming water to be between 11.5 and 12.5. The softening and clarification tank 102 is provided with a softening agent and a coagulant agent injection port. The softening adopts the caustic soda-soda softening method to soften the Ca in the water. 2+ Mg 2+ Respectively react with carbonate and alkali to form calcium carbonate and magnesium hydroxide precipitation, and the total hardness of the effluent from the softening clarification tank 102 is controlled by adjusting the amount of Na2CO3 and NaOH added. The softening clarification tank 102 is provided with a water outlet and a sludge outlet. The water outlet of the softening clarification tank 102 is connected to the self-cleaning filter 103 and the softening membrane 104 in sequence, and the sludge outlet is connected to the softening sludge dewatering system. The softening membrane 104 is provided with a water outlet and a sludge outlet. The water outlet of the softening membrane 104 is connected to the softening water tank 105, and the sludge outlet is connected to the softening sludge dewatering system. After dehydration and drying, the softened sludge can be sent to the lime plant for roasting, and the dehydrated clear liquid of the softening sludge dewatering system flows back into the pH regulating tank 101. The softening membrane 104 is equipped with a membrane cleaning agent dosing device. The softening water tank 105 is equipped with a backwashing pump to backwash the softening membrane 104, and the backwashing water flows into the pH regulating tank 101. The pretreatment unit 1 performs two-stage softening pretreatment by adding chemicals and membrane filtration to reduce harmful components such as hardness, alkalinity, silicate, suspended matter, and oil in the wastewater, so that the wastewater meets the requirements of membrane elements and salt separation. Among them, the softening membrane 104 can be selected from models such as TUF-37.

[0031] In a specific embodiment, the salt separation unit 2 includes a high-valent ion interception device 201. The water outlet of the pretreatment unit 1 (softening water tank 105) is connected to the water inlet of the high-valent ion interception device 201, and the water outlet and concentrated water outlet of the high-valent ion interception device 201 are both connected to the brine separation unit 3.

[0032] The salt separation unit 2 uses the Donan ion effect and pore size screening principle of the high-valent ion retention membrane to separate the wastewater into NaCl (KCl) solution and Na2SO4 solution. The principle of the salt separation technology of the high-valent ion retention device is similar to mechanical screening, and it also includes the dissolution diffusion effect, which makes it still have a high macromolecule and divalent salt retention effect at very low pressure. The salt separation unit 2 uses the characteristics of the high-valent ion retention process, which has a high retention rate for divalent or multivalent ions and organic matter with a molecular weight of more than 500, and almost no retention for organic pollutants with a molecular weight of less than 500 and monovalent salt ions, and separates the pre-treated high-salt water into high-valent ion retention device product water mainly composed of NaCl and high-valent ion retention device concentrated water mainly composed of Na2SO4.

[0033] The high-valent ion interception device 201 belongs to the prior art, and specifically includes an inlet pump, a security filter, a high-pressure pump, a high-valent ion interception membrane assembly, a cleaning water pump, a scale inhibitor dosing device, a modifier dosing device, and system supporting instruments, pipelines and valves. The inlet pump, the security filter, the high-pressure pump and the high-valent ion interception membrane assembly are connected in sequence through pipelines and valves. The outlets of the scale inhibitor dosing device and the modifier dosing device are both connected to the inlet pipeline of the security filter. The inlet of the cleaning water pump is connected to the recycled water tank 306, and the outlet is connected to the inlet of the high-valent ion interception membrane assembly. When the high-valent ion interception device needs to be cleaned, turn off the inlet pump, turn on the cleaning water pump to start the cleaning program. The high-valent ion interception membrane assembly can use models such as DK8040.

[0034] In a preferred embodiment, the salt separation unit 2 further comprises a high-valent ion water inlet pump. The water outlet of the pretreatment unit 1 (softening water tank 105) is connected to the water inlet of the high-valent ion interception device 201 through the high-valent ion water inlet pump.

[0035] In a preferred embodiment, the salt separation unit 2 further includes a water production tank and a concentrated water tank. The water production outlet of the high-valent ion interception device 201 is connected to the water production tank, which is then connected to the brine separation unit 3 (monovalent salt interception device 301 at the water production end). The concentrated water outlet of the high-valent ion interception device 201 is connected to the concentrated water tank, which is then connected to the brine separation unit 3 (electrochemical oxidation device 304).

[0036] In a specific embodiment, the brine separation unit 3 includes a monovalent salt interception device 301 at the water production end, an MVR evaporation crystallization device 303, an electrochemical oxidation device 304, a monovalent salt interception device 302 at the concentrate end, and a freezing crystallization device 305. The water production outlet of the high-valent ion interception device 201 is connected to the water inlet of the monovalent salt interception device 301 at the water production end, and the concentrated water outlet of the monovalent salt interception device 301 at the water production end is connected to the MVR evaporation crystallization device 303. The concentrated water outlet of the high-valent ion interception device 201 is connected to the water inlet of the electrochemical oxidation device 304, the water outlet of the electrochemical oxidation device 304 is connected to the water inlet of the monovalent salt interception device 302 at the concentrate end, and the concentrated water outlet of the monovalent salt interception device 302 at the concentrate end is connected to the freezing crystallization device 305.

[0037] The brine separation unit 3 includes a NaCl brine separation part and a Na2SO4 brine separation part. The NaCl brine separation part prepares NaCl crystalline salt through a combined process of re-concentration by a monovalent salt interception device and MVR evaporation crystallization, and the Na2SO4 brine separation part prepares Na2SO4 crystalline salt through a combined process of electrochemical oxidation high whiteness, re-concentration by a monovalent salt interception device and freezing crystallization, thereby realizing resource recycling. The NaCl solution is re-concentrated by the monovalent salt interception device 301 at the water production end, and the mass fraction of NaCl in the concentrated water can be concentrated to about 10%. The concentrated water enters the MVR evaporation crystallization device 303 for evaporation crystallization to prepare NaCl crystalline salt. The Na2SO4 impure salt solution first uses electrochemical oxidation to increase the whiteness of the Na2SO4 impure salt, and then further concentrates through the monovalent salt interception device 302 at the concentrated water end. The concentrated water enters the freezing crystallization device 305 to separate the Na2SO4 crystalline salt, and the frozen water is concentrated and then dried to produce impure salt.

[0038] Among them, the electrochemical oxidation device 304 belongs to the prior art, and specifically includes an electrolytic cell, a DC power supply, a BDD / stainless steel electrode, and system supporting instruments, pipes and valves. The concentrated water from the high-valent ion interception device 201 is connected to an external DC power in the electrolytic cell, and generates hydroxyl radicals (·OH) with strong oxidizing properties on the surface of the BDD electrode with water molecules as raw materials, which completely oxidizes the soluble organic matter in the water, thereby improving the whiteness of sulfate.

[0039] The monovalent salt interception device 301 at the production water end and the monovalent salt interception device 302 at the concentrate water end are both existing technologies, and both include an inlet pump, a security filter, a high-pressure pump, a monovalent salt interception membrane assembly, a cleaning water pump, a scale inhibitor dosing device, a modifier dosing device, a reductant dosing device, and system supporting instruments, pipelines and valves. The inlet pump, the security filter, the high-pressure pump and the monovalent salt interception membrane assembly are connected in sequence through pipelines and valves. The outlets of the scale inhibitor dosing device and the modifier dosing device are both connected to the inlet pipeline of the security filter. The inlet of the cleaning water pump is connected to the recycled water tank 306, and the outlet is connected to the inlet of the monovalent salt interception membrane assembly. When the monovalent salt ion interception device needs to be cleaned, turn off the inlet pump, turn on the cleaning water pump to start the cleaning procedure. The monovalent salt interception membrane assembly can be selected from models such as BW30FR.

[0040] The MVR evaporation crystallization device 303 belongs to the prior art, and specifically includes a feed box, a feed pump, a preheat exchanger, a steam preheater, a main heat exchanger, a circulating pump, a flash tank, a demister, a degassing tank, a steam compressor, a thickening tank, a centrifuge, a filtrate tank, a filtrate pump, and system supporting instruments, pipelines and valves. Among them, the feed box, the feed pump, the cold end inlet and outlet of the preheat exchanger, the cold end inlet and outlet of the steam preheater, the cold end inlet and outlet of the main heat exchanger, the flash tank, the demister, the degassing tank, and the steam compressor are connected in sequence. The outlet of the steam compressor is connected to the hot end inlet of the main heat exchanger, the hot end outlet of the main heat exchanger is connected to the hot end inlet of the preheat exchanger, and the hot end outlet of the preheat exchanger is connected to the inlet of the recycled water tank 306. The inlet of the thickening tank is connected to the crystal slurry outlet of the flash tank, and the outlet is connected to the centrifuge. The inlet of the filtrate tank is connected to the filtrate outlet of the centrifuge, and the outlet is connected to the filtrate pump to send the filtrate back to the feed box.

[0041] The freezing crystallization device 305 belongs to the prior art, and specifically includes a feed box, a feed pump, a precooler, an external cooler, a crystallizer, a thickener, a centrifuge, a mother liquor tank, a filtrate pump, and system supporting instruments, pipelines and valves. The feed box, the feed pump, the precooler, the external cooler, and the crystallizer are connected in sequence, the thickener inlet is connected to the crystal slurry outlet of the crystallizer, and the outlet is connected to the centrifuge. The filtrate tank inlet is connected to the centrifuge filtrate outlet, and the outlet is connected to the filtrate pump to send the filtrate back to the feed box.

[0042] In a preferred embodiment, the salt separation unit 3 further includes a produced water inlet pump and a concentrated water inlet pump. The salt separation unit 2 (water production tank) is connected to the produced water end monovalent salt interception device 301 through the produced water inlet pump. The salt separation unit 2 (concentrated water tank) is connected to the electrochemical oxidation device 304 through the concentrated water inlet pump.

[0043] In a preferred embodiment, the water produced by the two sets of monovalent salt interception devices in the brine separation section and the water discharged from the crystallization unit are sent to the reuse water tank 306 and reused in the circulating cooling water system of the plant. That is, the brine separation unit 3 also includes a reuse water tank 306. The water output outlets of the monovalent salt interception device 301 at the water production end and the monovalent salt interception device 302 at the concentrated water end are both connected to the reuse water tank 306, and the condensed water outlet of the MVR evaporation crystallization device 303 is also connected to the reuse water tank 306. The water in the reuse water tank 306 is pumped to the circulating cooling water system of the plant for reuse.

[0044] The process flow of the utility model petrochemical high-salt water zero-discharge device is as follows: the incoming water is adjusted to alkaline pH by adding NaOH in the pH regulating tank 101, the water discharged from the pH regulating tank 101 enters the softening clarification tank 102, and Na2CO3 is added to the water to react with Ca in the water. 2+ Mg 2+ The reaction forms a precipitate, and the supernatant water from the softening clarification tank 102 is filtered through the self-cleaning filter 103 and then enters the softening membrane 104, where the unprecipitated calcium carbonate, magnesium hydroxide and other suspended solids are further removed. The water from the softening membrane 104 flows by gravity into the softening water tank 105.

[0045] The water in the softening water tank 105 is pumped into the high-valent ion interception device 201 through the high-valent ion inlet pump. The high-valent ion interception device 201 separates the NaCl solution (product water) and the Na2SO4 solution (concentrated water). The product water of the high-valent ion interception device enters the water production tank and is pumped into the monovalent salt interception device 301 at the water production end through the product water inlet pump. The concentrated water of the high-valent ion interception device enters the concentrated water tank and is pumped into the electrochemical oxidation device 304 through the concentrated water inlet pump.

[0046] The NaCl solution is re-concentrated by the monovalent salt interception device 301 at the water production end, the produced water enters the reuse water tank 306, and the concentrated water enters the MVR evaporation crystallization device 303 for evaporation and crystallization to obtain crystallized salt. The Na2SO4 mixed salt solution is passed through the electrochemical oxidation device 304 to increase the whiteness of the sulfate, and then enters the monovalent salt interception device 302 at the concentrated water end for re-concentration, the produced water enters the reuse water tank 306, and the concentrated water enters the freezing crystallization device 305 for crystallization to obtain crystallized salt. The condensed water of the MVR evaporation crystallization device 303 also enters the reuse water tank 306.

[0047] After being processed by the petrochemical high-salt water zero-discharge device of the utility model, the purity of NaCl crystal salt can reach more than 95%, which meets the Grade I of solar-dried industrial salt in "Industrial Salt" (GB / T 5462-2015). The purity of Na2SO4 crystal salt can reach more than 98%, which meets the Grade III first-class product in "Industrial Anhydrous Sodium Sulfate" (GB / T 6009-2014).

[0048] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. used in the present invention are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships shall be deemed to be within the scope of implementation of the present invention without substantially changing the technical content.

[0049] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A petrochemical high-salt water zero discharge device, characterized by: It includes a pretreatment unit, a salt separation unit and a brine separation unit connected in sequence; The pretreatment unit is a unit for softening and filtering the water in the future; the pretreatment unit includes a softening clarification tank, a self-cleaning filter and a softening membrane connected in sequence; the water output outlet of the softening membrane is connected to the water inlet of the salt separation unit; The salt separation unit is a unit for separating NaCl solution and Na2SO4 solution from water; the salt separation unit includes a high-valent ion interception device; the water outlet of the pretreatment unit is connected to the water inlet of the high-valent ion interception device, and the water outlet and concentrated water outlet of the high-valent ion interception device are both connected to the brine separation unit; The brine separation unit is a unit for concentrating and crystallizing NaCl solution and Na2SO4 solution; the brine separation unit includes a monovalent salt interception device at the water production end, an MVR evaporation crystallization device, an electrochemical oxidation device, a monovalent salt interception device at the concentrate water end, and a freezing crystallization device; the water production outlet of the high-valent ion interception device is connected to the water inlet of the monovalent salt interception device at the water production end, and the concentrated water outlet of the monovalent salt interception device at the water production end is connected to the MVR evaporation crystallization device; the concentrated water outlet of the high-valent ion interception device is connected to the water inlet of the electrochemical oxidation device, the water outlet of the electrochemical oxidation device is connected to the water inlet of the monovalent salt interception device at the concentrate water end, and the concentrated water outlet of the monovalent salt interception device at the concentrate water end is connected to the freezing crystallization device.

2. The petrochemical high-salt water zero discharge device according to claim 1 is characterized in that: in, The pretreatment unit also includes a pH adjustment tank; The water outlet of the pH adjustment tank is connected to the water inlet of the softening and clarifying tank.

3. The petrochemical high-salt water zero discharge device according to claim 1 is characterized in that: in, The pretreatment unit also includes a softening water tank; The water output outlet of the softening membrane is connected to a softening water tank, and the softening water tank is further connected to the water inlet of the salt separation unit.

4. The petrochemical high-salt water zero discharge device according to claim 1 is characterized in that: in, The salt separation unit also includes a high-valence ion water inlet pump; The water outlet of the pretreatment unit is connected to the water inlet of the high-valent ion interception device through a high-valent ion water inlet pump.

5. The petrochemical high-salt water zero discharge device according to claim 1, Features: in, The salt separation unit also includes a water production tank and a concentrated water tank; The water production outlet of the high-valent ion interception device is connected to the water production tank, and the water production tank is further connected to the brine separation unit; The concentrated water outlet of the high-valent ion interception device is connected to the concentrated water tank, and the concentrated water tank is further connected to the brine separation unit.

6. The petrochemical high-salt water zero discharge device according to claim 1, Features: in, The brine separation unit also includes a produced water inlet pump and a concentrated water inlet pump; The salt separation unit is connected to the monovalent salt interception device at the water production end through a water production inlet pump; The salt separation unit is connected to the electrochemical oxidation device through a concentrated water inlet pump.

7. The petrochemical high-salt water zero discharge device according to claim 1 is characterized by: in, The brine separation unit also includes a recycled water tank; The water production outlets of the monovalent salt interception device at the water production end and the monovalent salt interception device at the concentrated water end are both connected to the reuse water tank, and the condensate outlet of the MVR evaporation crystallization device is also connected to the reuse water tank.

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