Styrene process condensate treatment and recycling system

Abstract

The utility model provides a styrene process condensate treatment and recycling system, which comprises a stripping tower, a condenser, a condenser and a condenser, a styrene process condensate inlet is formed in the upper part of the stripping tower; the bottom of the stripping tower is connected with a tower kettle liquid output pipeline; a tower top gas outlet is formed in the top of the stripping tower; a hot fluid side inlet of the stripping tower condenser is connected with a tower top gas outlet of the stripping tower, and a hot fluid side outlet of the stripping tower condenser is connected with the oil-water separation system; a cold fluid side inlet of the stripping tower condenser is connected with a styrene process condensate supply pipeline, and a cold fluid side outlet of the stripping tower condenser is connected with a styrene process condensate inlet; and the at least one heat exchanger is arranged on the tower kettle liquid output pipeline. According to the invention, the heat energy of the separated hydrocarbon substances can be fully utilized to preheat the styrene process condensate, the energy consumption is reduced, the recovered hydrocarbon substances return to the oil-water separation system to be recovered, and the material consumption is reduced; and heating the dehydrogenation liquid and / or ethylene gas by utilizing residual heat energy in process condensate treatment.

Description

TECHNICAL FIELD

[0001] The application relates to a chemical energy-saving device, in particular to a styrene process condensate treatment and recycling system. BACKGROUND

[0002] Styrene is an important monomer for synthetic resins and synthetic rubber, and is widely used in the automobile, home appliance and building industries, and is an important raw material in the chemical industry. At present, the mainstream method for preparing styrene in the world is the ethylbenzene dehydrogenation method, which is mature in process and has low energy consumption and few by-products. However, the ethylbenzene dehydrogenation reaction in the process is a reversible endothermic molecular reaction, and needs to be carried out in a steam environment to effectively make the reaction proceed in the forward direction, so a large amount of process condensate is generated. The traditional process condensate utilization method is to directly send the process condensate to a sewage treatment plant for treatment and then directly discharge the treated process condensate. This greatly increases the water consumption cost of the styrene device. CONTENT OF THE UTILITY MODEL

[0003] In view of the above technical problems existing in the prior art, the application embodiment provides a styrene process condensate treatment and recycling system to solve the problem of large water consumption in the prior art.

[0004] The technical scheme adopted by the application embodiment is that a styrene process condensate treatment and recycling system comprises:

[0005] A stripping tower is provided, a steam inlet is arranged at the lower part of the stripping tower, and water vapor is sent into the stripping tower through the steam inlet; a styrene process condensate inlet is arranged at the upper part of the stripping tower, and styrene process condensate is sent into the stripping tower through the styrene process condensate inlet; a tower bottom liquid outlet is arranged at the bottom of the stripping tower, and the tower bottom liquid outlet is connected to a tower bottom liquid output pipeline; and a tower top gas outlet is arranged at the top of the stripping tower.

[0006] A stripping tower condenser is arranged, a hot fluid side inlet of the stripping tower condenser is connected to the tower top gas outlet of the stripping tower, a hot fluid side outlet of the stripping tower condenser is connected to an oil-water separation system, a cold fluid side inlet of the stripping tower condenser is connected to a styrene process condensate liquid supply pipeline, and a cold fluid side outlet of the stripping tower condenser is connected to the styrene process condensate inlet.

[0007] At least one heat exchanger is arranged on the tower bottom liquid output pipeline, and is used at least for heating dehydrogenation liquid and / or ethylene gas.

[0008] In an optional embodiment, the ends of the tower bottom liquid output pipeline are respectively connected to a plurality of reserved pipelines, and the plurality of reserved pipelines are respectively connected to a circulating water return main pipe, a fire water tank and a desalted water station primary water replenishment main pipe.

[0009] In an optional embodiment, control valves for controlling the flow of fluid are arranged on the plurality of reserved pipelines.

[0010] In an optional embodiment, the styrene process condensate treatment and recycling system further comprises a branch pipeline, one end of the branch pipeline is connected with the column bottom liquid output pipeline, and the connection position of the branch pipeline and the column bottom liquid output pipeline is located downstream of the heat exchanger, a composite fiber filter, an iron removal filter and an oil removal filter are sequentially arranged on the branch pipeline along the flow direction of fluid.

[0011] In an optional embodiment, the heat exchanger comprises a first heat exchanger and a second heat exchanger.

[0012] The cold fluid side inlet of the first heat exchanger is connected with the dehydrogenation liquid inlet pipeline, and the cold fluid side outlet of the first heat exchanger is connected with the dehydrogenation liquid return pipeline.

[0013] The cold fluid side inlet of the second heat exchanger is connected with the ethylene gas inlet pipeline, and the cold fluid side outlet of the second heat exchanger is connected with the ethylene gas outlet pipeline.

[0014] The column bottom liquid output pipeline is in communication with the hot fluid sides of the first heat exchanger and the second heat exchanger in sequence, so that the column bottom liquid transported in the column bottom liquid output pipeline flows through the hot fluid sides of the first heat exchanger and the second heat exchanger in sequence, and exchanges heat with the dehydrogenation liquid flowing through the cold fluid side of the first heat exchanger and the ethylene gas flowing through the cold fluid side of the second heat exchanger in sequence.

[0015] In an optional embodiment, a coarse filter, a stripping column bottom liquid pump and a chlorine removal device are sequentially arranged on the column bottom liquid output pipeline along the flow direction of fluid, and the chlorine removal device is located upstream of the heat exchanger.

[0016] In an optional embodiment, the styrene process condensate treatment and recycling system further comprises a stripping column post-cooler, the cold fluid side inlet of the stripping column post-cooler is connected with the circulating water feed pipeline, and the cold fluid side outlet of the stripping column post-cooler is connected with the circulating water return pipeline.

[0017] The stripping column condenser is provided with a first non-condensed gas outlet in communication with the hot fluid side thereof, and the stripping column post-cooler is provided with a second non-condensed gas outlet in communication with the hot fluid side thereof.

[0018] The hot fluid side inlet of the stripping column post-cooler is connected with the first non-condensed gas outlet of the stripping column condenser, the hot fluid side outlet of the stripping column post-cooler is connected with an oil-water separation system, and the second non-condensed gas outlet of the stripping column post-cooler is connected with a dehydrogenation tail gas treatment system.

[0019] In an optional embodiment, the hot fluid side outlet of the stripping column post-cooler is provided with a water separation package, the hot fluid side outlet of the stripping column post-cooler is connected to the water separation package, and the water separation package is connected with the oil-water separation system.

[0020] In an optional embodiment, the stripping column is a sieve tray column.

[0021] Compared with the prior art, the embodiment of the application has the beneficial effects that the hydrocarbon substances in the styrene process condensate can be separated, the heat energy of the separated hydrocarbon substances is fully utilized to preheat the styrene process condensate as the stripping column feed, the energy consumption is reduced, the recovered hydrocarbon substances are returned to the oil-water separation system for further recovery, the material consumption is reduced, the residual heat energy in the process condensate treatment is fully utilized, the styrene process condensate is used as circulating water, fire-fighting water and desalination water station primary water make-up water, and the water consumption of the device is reduced.

[0022] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory in nature and are not intended to limit the present application.

[0023] The summary of various implementations or examples of the technology described in this application is not a comprehensive disclosure of the full scope or all features of the disclosed technology. BRIEF DESCRIPTION OF DRAWINGS

[0024] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. The drawings illustrate generally, by way of example, various embodiments in which the principles of the application can be implemented and are not intended to limit the application. The same reference numerals in different drawings can identify the same or similar elements. Such embodiments are examples only, and are not intended to be exhaustive or limiting of the disclosure. The disclosure is intended to cover any and all adaptations or variations of various embodiments.

[0025] Figure 1 FIG. 1 is a schematic diagram of a styrene process condensate treatment and recycling system according to an embodiment of the application.

[0026] REFERENCE NUMERALS:

[0027] 1-stripping column; 2-stripping column condenser; 3-first heat exchanger; 4-second heat exchanger; 5-column bottom liquid output pipeline; 6-first reserved pipeline; 7-second reserved pipeline; 8-third reserved pipeline; 9-circulating water return main pipeline; 10-fire water tank; 11-desalinated water station primary water replenishment main pipeline; 12-desalinated water supply main pipeline; 13-branch pipeline; 14-composite fiber filter; 15-iron removal filter; 16-oil removal filter; 18-dehydrogenated liquid inlet pipeline; 19-dehydrogenated liquid return pipeline; 20-ethylene gas inlet pipeline; 21-ethylene gas return pipeline; 22-coarse filter; 23-stripping column bottom liquid pump; 24-chlorine removal device; 25-stripping column post-cooler; 26-styrene process condensate liquid supply pipeline; 27-steam supply pipeline; 28-oil-water separation system; 29-dehydrogenated tail gas treatment system; 30-water trap; 31-first control valve; 32-second control valve; 33-third control valve; 34-fourth control valve. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the scope of protection of the present application.

[0029] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the usual meaning understood by one of ordinary skill in the art to which the present application pertains. The terms "first", "second" and similar terms used in the present application do not indicate any order, number or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like only indicate relative positional relationships, which can change accordingly when the absolute positions of the described objects change.

[0030] In order to keep the following description of the embodiments of the present application clear and brief, the present application omits the detailed description of known functions and known components.

[0031] As shown in Figure 1 The embodiments of the present application provide a styrene process condensate treatment and recycling system, which comprises a stripping column 1, a stripping column condenser 2 and at least one heat exchanger.

[0032] The stripping tower 1 can adopt sieve plate tower. The lower part of the stripping tower 1 is provided with a steam inlet, the steam inlet is connected with a steam supply pipeline 27, and the steam inlet is used for feeding steam into the stripping tower 1; the upper part of the stripping tower 1 is provided with a styrene process condensate inlet, the styrene process condensate inlet is used for feeding styrene process condensate into the stripping tower 1; the bottom of the stripping tower 1 is provided with a tower bottom liquid outlet, the tower bottom liquid outlet is connected with a tower bottom liquid output pipeline 5; and the top of the stripping tower 1 is provided with a tower top gas outlet. The main component of the styrene process condensate is water, and a small amount of hydrocarbon organic matter is contained. Through the stripping action of the steam, most of the hydrocarbon substances in the styrene process condensate flowing out of the top are removed. The removed hydrocarbon substances entrain a part of the steam, that is, a hydrocarbon-steam mixture is formed and discharged from the tower top gas outlet. The temperature of the discharged hydrocarbon-steam mixture is about 77°C. The styrene process condensate after removal of the hydrocarbon substances is collected in the tower bottom and discharged from the stripping tower 1 through the tower bottom liquid output pipeline 5.

[0033] In the formula, the steam is low-low pressure steam, and the pressure range of the low-low pressure steam can be 0.03-0.05 MPa. In this way, the content of the steam entrained by the hydrocarbon substances discharged from the tower top gas outlet is not too large due to the excessively large steam pressure.

[0034] The hot fluid side inlet of the stripping tower condenser 2 is connected with the tower top gas outlet of the stripping tower 1, the hot fluid side outlet of the stripping tower condenser 2 is connected with an oil-water separation system 28; the cold fluid side inlet of the stripping tower condenser 2 is connected with a styrene process condensate liquid supply pipeline 26, and the cold fluid side outlet of the stripping tower condenser 2 is connected with the styrene process condensate inlet. In this way, the hydrocarbon-steam mixture with a temperature of about 77°C discharged from the top of the stripping tower 1 enters the hot fluid side of the stripping tower condenser 2 and exchanges heat with the styrene process condensate entering the cold fluid side of the stripping tower condenser 2, so that the hydrocarbon-steam mixture is cooled and condensed to obtain a condensate with a temperature of about 65°C, which is returned to the oil-water separation system 28. The styrene process condensate is heated by absorbing the heat of the hydrocarbon-steam mixture and then enters the stripping tower 1. The heat energy contained in the hydrocarbon-steam mixture is used to preheat the styrene process condensate fed into the stripping tower 1, thereby reducing energy consumption. Avoiding direct discharge of the hydrocarbon-steam mixture to cause a large amount of heat energy loss, thereby reducing production cost.

[0035] The heat exchanger is at least one and is arranged on the tower bottom liquid output pipeline 5. The tower bottom liquid (the temperature of the tower bottom liquid of the stripping tower 1 is about 82°C) in the tower bottom liquid output pipeline 5 is used to heat at least dehydrogenation liquid and / or ethylene gas when flowing through the heat exchanger, so as to fully utilize the residual heat energy in the styrene process condensate treatment.

[0036] In some embodiments, the above-mentioned embodiments are combined. Figure 1The end of the tower kettle liquid output pipeline 5 is connected with a plurality of reserved pipelines, and the plurality of reserved pipelines are respectively connected with a circulating water return main pipe 9, a fire water tank 10 and a desalination water station primary water replenishment main pipe 11. Thus, the treated and heat-exchanged styrene process condensate liquid can be used as circulating water, fire water and desalination water station primary water replenishment, and the tower kettle liquid is recovered, and water resources are saved.

[0037] For example, the reserved pipelines include a first reserved pipeline 6, a second reserved pipeline 7 and a third reserved pipeline 8. The first reserved pipeline 6 is connected to the circulating water return main pipe 9, so that the qualified tower kettle liquid can be introduced into the circulating water return main pipe 9 to be used as circulating water replenishment in the circulating water field. Meanwhile, a first control valve 31 is installed on the first reserved pipeline 6, so as to facilitate control of the replenishment amount. The second reserved pipeline 7 is connected to the fire water tank 10, so that the qualified tower kettle liquid can be introduced into the fire water tank 10 to be used as fire water replenishment of the fire water tank 10. Meanwhile, a second control valve 32 is installed on the second reserved pipeline 7, so as to facilitate control of the replenishment amount. The third reserved pipeline 8 is connected to the desalination water station primary water replenishment main pipe 11, so that the qualified tower kettle liquid can be introduced into the desalination water station primary water replenishment main pipe 11 to be used as desalination water replenishment of the desalination water station. Meanwhile, a third control valve 33 is installed on the third reserved pipeline 8, so as to facilitate control of the replenishment amount.

[0038] In some embodiments, as shown in Figure 1 The styrene process condensate liquid treatment and recycling system further includes a branch pipeline 13, one end of the branch pipeline 13 is connected with the tower kettle liquid output pipeline 5, and the connection position of the branch pipeline 13 and the tower kettle liquid output pipeline 5 is located downstream of the heat exchanger. A composite fiber filter 14, an iron removal filter 15 and an oil removal filter 16 are sequentially arranged on the branch pipeline 13 along the flow direction of the fluid, and the end of the branch pipeline 13 is connected to a desalination water supply main pipe 12 of the styrene device. Thus, the tower kettle liquid first passes through the composite fiber filter 14 to remove suspended impurities therein, then enters the iron removal filter 15 to further remove iron ions in the condensate liquid, and finally enters the high-efficiency oil removal filter 16 to remove trace hydrocarbon substances contained in the condensate liquid. The obtained condensate liquid is directly introduced into the desalination water supply main pipe 12 of the styrene device to be directly used as desalination water. Meanwhile, a fourth control valve 34 is installed on the branch pipeline 13, so as to facilitate control of the amount.

[0039] For example, the reserved pipelines include a first reserved pipeline 6, a second reserved pipeline 7 and a third reserved pipeline 8. The first reserved pipeline 6 is connected to the circulating water return main pipe 9, so that the qualified tower kettle liquid can be introduced into the circulating water return main pipe 9 to be used as circulating water replenishment in the circulating water field. Meanwhile, a first control valve 31 is installed on the first reserved pipeline 6, so as to facilitate control of the replenishment amount. The second reserved pipeline 7 is connected to the fire water tank 10, so that the qualified tower kettle liquid can be introduced into the fire water tank 10 to be used as fire water replenishment of the fire water tank 10. Meanwhile, a second control valve 32 is installed on the second reserved pipeline 7, so as to facilitate control of the replenishment amount. The third reserved pipeline 8 is connected to the desalination water station primary water replenishment main pipe 11, so that the qualified tower kettle liquid can be introduced into the desalination water station primary water replenishment main pipe 11 to be used as desalination water replenishment of the desalination water station. Meanwhile, a third control valve 33 is installed on the third reserved pipeline 8, so as to facilitate control of the replenishment amount. Figure 1As shown, the heat exchanger includes a first heat exchanger 3 and a second heat exchanger 4. The first heat exchanger 3 is located upstream of the second heat exchanger 4. The cold fluid side inlet of the first heat exchanger 3 is connected to the dehydrogenation liquid inlet pipeline 18, and the cold fluid side outlet of the first heat exchanger 3 is connected to the dehydrogenation liquid return pipeline 19. That is, the dehydrogenation liquid flows through the cold fluid side of the first heat exchanger 3. The cold fluid side inlet of the second heat exchanger 4 is connected to the ethylene gas inlet pipeline 20, and the cold fluid side outlet of the second heat exchanger 4 is connected to the ethylene gas outlet pipeline 21. That is, the ethylene gas flows through the cold fluid side of the second heat exchanger 4.

[0040] The column still liquid output pipeline 5 is in communication with the hot fluid sides of the first heat exchanger 3 and the second heat exchanger 4 in sequence, so that the column still liquid transported in the column still liquid output pipeline 5 flows through the hot fluid sides of the first heat exchanger 3 and the second heat exchanger 4 in sequence, and preheats the dehydrogenation liquid flowing through the cold fluid side of the first heat exchanger 3 and heats the ethylene gas flowing through the cold fluid side of the second heat exchanger 4 in sequence, so as to fully utilize the heat energy in the column still liquid (condensate).

[0041] When the first heat exchanger 3 is a shell-and-tube heat exchanger, the shell side is the cold fluid side and the tube side is the hot fluid side, the dehydrogenation liquid flows through the shell side of the first heat exchanger 3, and the column still liquid flows through the tube side of the first heat exchanger 3. When the second heat exchanger 4 is a shell-and-tube heat exchanger, the shell side is the cold fluid side and the tube side is the hot fluid side, the ethylene gas flows through the shell side of the second heat exchanger 4, and the column still liquid flows through the tube side of the second heat exchanger 4.

[0042] The column still liquid is subjected to heat recovery twice, the heat energy of the column still liquid is fully utilized, the heat energy recovery utilization rate is improved, the waste of heat energy is reduced, and the production cost is reduced.

[0043] Continuing to combine Figure 1 , the column still liquid output pipeline 5 is further provided with a coarse filter 22, a stripping column still liquid pump 23 and a chlorine remover 24 in sequence upstream of the heat exchanger along the flow direction of the flow. After the column still liquid of the stripping column 1 is discharged, it first passes through the coarse filter 22 to remove some particulate impurities, so that the column still liquid index can reach the level of the subsequent level as circulating water, fire-fighting water and primary water, and then goes to the stripping column still liquid pump 23 for pressure boosting, and then enters the water chlorine remover 24 to remove chlorine in the condensate to prevent pipeline corrosion.

[0044] In some embodiments, as shown in Figure 1 , the styrene process condensate treatment and recovery system further includes a stripping column post-cooler 25, and the cold fluid side inlet of the stripping column post-cooler 25 is connected to the circulating water feed pipeline, and the cold fluid side outlet of the stripping column post-cooler 25 is connected to the circulating water return pipeline.

[0045] The stripping column condenser 2 is provided with a first non-condensed gas outlet in communication with the hot fluid side thereof, and the stripping column post-cooler 25 is provided with a second non-condensed gas outlet in communication with the hot fluid side thereof.

[0046] The hot fluid side inlet of the stripping tower aftercooler 25 is connected to the first non-condensable gas outlet of the stripping tower condenser 2, the hot fluid side outlet of the stripping tower aftercooler 25 is connected to the oil-water separation system 28, and the second non-condensable gas outlet of the stripping tower aftercooler 25 is connected to the dehydrogenation tail gas treatment system 29.

[0047] By providing the stripping tower aftercooler 25 , the uncondensed gas in the stripping tower condenser 2 can enter the stripping tower aftercooler 25 for further condensation and cooling, and the condensate returns to the oil-water separation system 28 , while the uncondensed gas flows into the dehydrogenation tail gas treatment system 29 .

[0048] When the stripping tower condenser 2 is a shell-and-tube structure, the tube side represents the hot fluid side, while the shell side represents the cold fluid side. The hydrocarbon-water vapor mixture discharged from the overhead gas outlet of the stripping tower 1 flows through the tube side, while the styrene process condensate flows through the shell side. When the stripping tower aftercooler 25 is a shell-and-tube structure, the tube side represents the hot fluid side, while the shell side represents the cold fluid side. Uncondensed gases on the hot fluid side of the stripping tower condenser 2 flow through the tube side, while the circulating water flows through the shell side.

[0049] like Figure 1 As shown, a water separator 30 is provided at the hot fluid outlet of the stripping tower aftercooler 25. The hot fluid outlet of the stripping tower aftercooler 25 is connected to the water separator 30, which is in turn connected to the oil-water separation system 28. In other words, the condensate from the hot fluid side of the stripping tower condenser 2 and the condensate from the hot fluid side of the stripping tower aftercooler 25 are collected in the water separator 30 and then returned to the oil-water separation system 28.

[0050] The styrene process condensate treatment and recycling system of the embodiment of the present application can, firstly, separate hydrocarbon substances from the styrene process condensate, and at the same time fully utilize the heat energy of the separated hydrocarbon-water vapor mixture to preheat the feed of the stripping tower 1 - the styrene process condensate, thereby reducing energy consumption. At the same time, the recovered hydrocarbon substances are returned to the oil-water separation system 28 for further recovery, thereby reducing material consumption; secondly, in order to fully utilize the residual heat energy in the treatment of the styrene process condensate, a heat exchanger is installed on the tower bottom liquid output pipeline 5 for preheating the dehydrogenation liquid and for heating the ethylene gas; thirdly, in order to fully utilize the treated styrene process condensate, reserved pipelines are respectively configured so that the condensate can be used as circulating water, fire water, primary water and (after treatment) desalted water, thereby reducing water consumption of the device.

[0051] The above description is intended to be illustrative rather than restrictive, and those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure. Furthermore, the above examples (or one or more of them) may be used in combination with each other, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations.

Claims

1. A styrene process condensate treatment and recycling system, characterized in that: include: A stripping tower, wherein a steam inlet is provided at the lower portion of the stripping tower, through which water vapor is fed into the stripping tower; a styrene process condensate inlet is provided at the upper portion of the stripping tower, through which styrene process condensate is fed into the stripping tower; a bottom liquid outlet is provided at the bottom of the stripping tower, the bottom liquid outlet being connected to a bottom liquid output pipeline; and a top gas outlet is provided at the top of the stripping tower; A stripping tower condenser, wherein the hot fluid side inlet of the stripping tower condenser is connected to the tower top gas outlet of the stripping tower, and the hot fluid side outlet of the stripping tower condenser is connected to the oil-water separation system; the cold fluid side inlet of the stripping tower condenser is connected to the styrene process condensate supply pipeline, and the cold fluid side outlet of the stripping tower condenser is connected to the styrene process condensate inlet; At least one heat exchanger is provided on the bottom liquid output pipeline and is used at least to heat the dehydrogenation liquid and / or ethylene gas.

2. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: The ends of the tower bottom liquid output pipeline are respectively connected to a plurality of reserved pipelines, and the plurality of reserved pipelines are respectively connected to the circulating water return pipe, the fire water tank and the primary water replenishment pipe of the desalted water station.

3. The styrene process condensate treatment and recycling system according to claim 2, characterized in that: A plurality of the reserved pipelines are respectively provided with control valves for controlling the flow rate of the fluid.

4. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: The styrene process condensate treatment and recycling system also includes a branch pipeline, one end of which is connected to the bottom liquid output pipeline, and the connection between the branch pipeline and the bottom liquid output pipeline is located downstream of the heat exchanger. A composite fiber filter, an iron removal filter and an oil removal filter are sequentially arranged on the branch pipeline along the flow direction of the fluid.

5. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: The heat exchanger includes a first heat exchanger and a second heat exchanger; The cold fluid side inlet of the first heat exchanger is connected to the dehydrogenation liquid inlet pipeline, and the cold fluid side outlet of the first heat exchanger is connected to the dehydrogenation liquid return pipeline; The cold fluid side inlet of the second heat exchanger is connected to the ethylene gas inlet pipeline, and the cold fluid side outlet of the second heat exchanger is connected to the ethylene gas return pipeline; The bottom liquid output pipeline is sequentially connected to the hot fluid sides of the first heat exchanger and the second heat exchanger, so that the bottom liquid transported in the bottom liquid output pipeline flows through the hot fluid sides of the first heat exchanger and the second heat exchanger in sequence, and exchanges heat with the dehydrogenation liquid flowing through the cold fluid side of the first heat exchanger and the ethylene gas flowing through the cold fluid side of the second heat exchanger in sequence.

6. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: A coarse filter, a stripping tower bottom liquid pump and a dechlorinator are sequentially provided on the bottom liquid output pipeline along the flow direction of the circulation, and the dechlorinator is located upstream of the heat exchanger.

7. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: The styrene process condensate treatment and recycling system further comprises a stripping tower aftercooler, wherein the cold fluid side inlet of the stripping tower aftercooler is connected to a circulating water supply pipeline, and the cold fluid side outlet of the stripping tower aftercooler is connected to a circulating water return pipeline; The stripping tower condenser is provided with a first non-condensable gas outlet communicating with its hot fluid side, and the stripping tower aftercooler is provided with a second non-condensable gas outlet communicating with its hot fluid side; The hot fluid side inlet of the stripping tower aftercooler is connected to the first non-condensable gas outlet of the stripping tower condenser, the hot fluid side outlet of the stripping tower aftercooler is connected to the oil-water separation system, and the second non-condensable gas outlet of the stripping tower aftercooler is connected to the dehydrogenation tail gas treatment system.

8. The styrene process condensate treatment and recycling system according to claim 7, characterized in that: The hot fluid side outlet of the stripping tower aftercooler is provided with a water separation bag, the hot fluid side outlet of the stripping tower aftercooler is connected to the water separation bag, and the water separation bag is connected to the oil-water separation system.

9. The styrene process condensate treatment and recycling system according to claim 1, characterized in that: The stripping tower is a sieve plate tower.

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