System for removing methanol in hexafluoropropylene

Abstract

The utility model discloses a system for removing methanol in hexafluoropropylene, and relates to the technical field of hexafluoropropylene purification. A system for removing methanol in hexafluoropropylene comprises a crude product tank used for containing hexafluoropropylene mixed gas; the water washing tower group is used for washing to remove methanol in the hexafluoropropylene mixed gas and is connected with the crude product tank; the circulating assembly is used for recycling water washing liquid used by the water washing tower set, and the feeding end and the discharging end of the circulating assembly are both connected with the water washing tower set; the dehydrator is used for dehydrating the hexafluoropropylene mixed gas treated by the water washing tower group and is in butt joint with a discharge hole of the water washing tower group; and the qualified product tank is used for containing the dewatered hexafluoropropylene mixed gas and is in butt joint with the dewaterer. The system solves the problems of high energy consumption and poor methanol removal effect during methanol removal.

Description

Technical Field

[0001] The utility model relates to the technical field of hexafluoropropylene purification, in particular to a system for removing methanol from hexafluoropropylene. Background Art

[0002] In the production of tetrafluoroethylene monomer, the amount of by-product hexafluoropropylene accounts for about 1% to 2% of tetrafluoroethylene. The existing method of recovering by-product hexafluoropropylene from the tetrafluoroethylene production process mostly uses a methanol extraction distillation process to directly remove the methanol in hexafluoropropylene. For example, the method disclosed in patent CN1872824 can reach more than 99.99% of the by-product hexafluoropropylene after distillation, but it still contains 2 to 50 mg / L of methanol. Hexafluoropropylene containing trace amounts of methanol is only used as a common fine chemical and cannot meet the polymerization reaction requirements of users such as perfluoroethylene propylene resin and fluororubber, which have higher requirements. Therefore, completely removing trace amounts of methanol in by-product hexafluoropropylene plays an important role in improving the value of by-product hexafluoropropylene. However, due to the presence of hydrogen bonds in methanol, the above-mentioned distillation process has no way to completely remove the methanol therein even if a large reflux ratio is used, resulting in energy waste.

[0003] The method disclosed in patent CN107663144A includes: 1) introducing hexafluoropropylene, a byproduct of tetrafluoroethylene, into a distillation system in a hexafluoropropylene production device, reacting hexafluoropropylene containing methanol with octafluoroisobutylene, a byproduct of hexafluoropropylene production, to obtain a mixture containing octafluoro tert-butyl methyl ether; 2) removing octafluoro tert-butyl methyl ether from the mixture containing octafluoro tert-butyl methyl ether by distillation to obtain pure hexafluoropropylene. The above treatment method has a long flow and a complicated process, and requires two distillations after the reaction. If there is residual methanol in the distillation system of the hexafluoropropylene production device, it will affect the normal production of hexafluoropropylene.

[0004] The prior art lacks a system that can ensure the removal effect of methanol on the basis of low energy consumption. Utility Model Content

[0005] The technical problem to be solved by the utility model is that the prior art lacks a system that can improve the removal effect of methanol on the basis of saving energy. The purpose is to provide a system for removing methanol from hexafluoropropylene to solve the problems of high energy consumption and poor methanol removal effect when removing methanol.

[0006] The utility model is realized by the following technical solutions:

[0007] A system for removing methanol from hexafluoropropylene, comprising

[0008] Crude product tank, used to contain hexafluoropropylene mixed gas;

[0009] A water washing tower group, used for washing and removing methanol from the hexafluoropropylene mixed gas, connected to the crude product tank;

[0010] A circulation component is used to recycle the water washing liquid used by the water washing tower group, and both the feed end and the discharge end are connected to the water washing tower group;

[0011] A dehydrator, used to dehydrate the hexafluoropropylene mixed gas after being treated by the water scrubber group, and connected to the discharge port of the water scrubber group;

[0012] The qualified product tank is used to hold the dehydrated hexafluoropropylene mixed gas and is connected to the dehydrator.

[0013] As a possible design, the water scrubber group includes an air inlet pipe, a first water scrubber, an air delivery pipe, a second water scrubber, an exhaust pipe, a sprayer, a first liquid inlet pipe, and a second liquid inlet pipe.

[0014] The air inlet pipe is connected to the discharge end of the crude product tank and is used to transport the hexafluoropropylene mixed gas;

[0015] The middle section of the first water washing tower is connected to the air inlet pipe and is used to initially treat the hexafluoropropylene mixed gas;

[0016] The gas delivery pipe is connected to the gas outlet of the first water washing tower and is used to output the initially treated hexafluoropropylene mixed gas;

[0017] The middle section of the second water scrubber is connected to the gas pipeline for reprocessing the initially treated hexafluoropropylene mixed gas;

[0018] The exhaust pipe is connected to the gas outlet of the second water washing tower and the dehydrator respectively, and is used to send the hexafluoropropylene mixed gas after methanol removal to the dehydrator for dehydration;

[0019] The first liquid inlet pipe is connected to the middle section of the first water washing tower and is used to input the external washing liquid into the first water washing tower;

[0020] The second liquid inlet pipe is connected to the middle section of the second water washing tower and is used to input the external water washing liquid into the second water washing tower;

[0021] There are multiple sprayers, and the multiple sprayers are respectively installed in the first water washing tower and the second water washing tower.

[0022] As a possible design, the liquid outlet end of the dehydrator is connected to the top of the second water washing tower through a first liquid return pipe.

[0023] As a possible design, the circulation assembly includes a first circulation pipe, a first circulation pump, a second circulation pipe and a second circulation pump.

[0024] The two ends of the first circulation pipe are respectively connected to the sprayer of the first water washing tower and the liquid outlet of the first water washing tower;

[0025] The first circulation pump is installed on the first circulation pipe, and is used to pump the washing liquid in the first water washing tower to the top of the first water washing tower to wash the hexafluoropropylene mixed gas with water;

[0026] Both ends of the second circulation pipe are respectively connected to the sprayer of the second water washing tower and the liquid outlet of the second water washing tower;

[0027] The second circulation pump is installed on the second circulation pipe, and is used to pump the washing liquid in the second water washing tower to the top of the second water washing tower to wash the hexafluoropropylene mixed gas again.

[0028] As a possible design, the first circulation pipe and the second circulation pipe are both connected to the waste liquid discharge pipe.

[0029] As a possible design, the first circulation pipe and the second circulation pipe are both provided with heating jackets.

[0030] As a possible design, flow meters are installed on the first circulation pipe and the second circulation pipe.

[0031] As a possible design, pressure gauges are installed on the first circulation pipe and the second circulation pipe.

[0032] As a possible design, a dehydration buffer tank is connected between the above-mentioned dehydrator and the qualified product tank, the air outlet end of the dehydrator is connected to the air inlet end of the dehydration buffer tank through a first air storage pipe, the air outlet end of the dehydration buffer tank is connected to the qualified product tank through a second air storage pipe, and the liquid outlet end of the dehydration buffer tank is connected to the second water washing tower through a second liquid return pipe.

[0033] As a possible design, the air inlet pipe and the air delivery pipe are respectively connected with air extraction pipes, and the air extraction pipes are used to extract oxygen in the first water scrubber and the second water scrubber.

[0034] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0035] The utility model washes the hexafluoropropylene mixed gas with water for multiple times, utilizes the mutual solubility of methanol and water, separates the methanol in the gas into the washing liquid, and inputs the hexafluoropropylene into the dehydrator in the form of gas for dehydration, thereby obtaining the hexafluoropropylene gas from which the methanol is removed. The methanol content of the gas after being treated by the system is reduced to about 0.02-0.03 mg / L, thus meeting the polymerization reaction requirements of the production users of perfluoroethylene propylene resin, fluororubber, etc.

[0036] In addition, the washing liquid can be reused through the circulation component to save resources. Each time the washing liquid is sprayed for washing, the methanol in the hexafluoropropylene mixed gas is fully in contact with the washing liquid, so that the methanol is dissolved in water. The entire system has a simple use process, and methanol is directly absorbed by spraying with water without distillation treatment. Since it does not enter the distillation system of the hexafluoropropylene production device, it will not affect the normal production of hexafluoropropylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, constitute a part of this application, and do not constitute a limitation of the embodiments of the present utility model. In the drawings:

[0038] Figure 1 This is a schematic diagram of the connection structure of a system for removing methanol from hexafluoropropylene according to the utility model;

[0039] Figure 2 This is one of the partial connection structure schematic diagrams of a system for removing methanol from hexafluoropropylene according to the utility model;

[0040] Figure 3 This is the second schematic diagram of the partial connection structure of a system for removing methanol from hexafluoropropylene according to the utility model;

[0041] Figure 4 This is the third schematic diagram of the partial connection structure of a system for removing methanol from hexafluoropropylene according to the utility model.

[0042] Marks and corresponding parts names in the attached drawings:

[0043] 1-crude product tank; 2-water washing tower group; 21-first water washing tower; 22-second water washing tower; 23-first liquid inlet pipe; 24-second liquid inlet pipe; 25-air inlet pipe; 251-exhaust pipe; 26-gas transmission pipe; 27-exhaust pipe; 28-first return liquid pipe; 29-sprinkler; 3-circulation assembly; 31-first circulation pipe; 32-first circulation pump; 33-second circulation pipe; 34-second circulation pump; 35-waste liquid discharge pipe; 36-heating jacket; 37-flow meter; 38-pressure gauge; 4-dehydrator; 5-qualified product tank; 6-dehydration buffer tank; 61-first gas storage pipe; 62-second gas storage pipe; 63-second return liquid pipe. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0045] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component.

[0046] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0049] This embodiment provides a system for removing methanol from hexafluoropropylene, such as Figure 1-4As shown, the system separates the methanol in the hexafluoropropylene mixed gas into the water washing liquid after multiple spraying and washing, and the methanol content in the remaining gas is greatly reduced to meet the qualified standard. After the experiment of this embodiment, the methanol content of the treated gas is reduced from 2 to 10 mg / L to about 0.02 to 0.03 mg / L. The system for removing methanol from hexafluoropropylene includes a crude product tank 1, a water washing tower group 2, a circulation component 3, a dehydrator 4 and a qualified product tank 5. The crude product tank 1 is used to hold the hexafluoropropylene mixed gas, which can be any container for storing gas. The crude product tank 1 is connected to the water scrubber group 2, so that the stored hexafluoropropylene mixed gas can be transported to the water scrubber group 2 for treatment. One end of the water scrubber group 2 is connected to the crude product tank 1, and the other end is connected to the dehydrator 4, which is connected to external deionized water. The hexafluoropropylene mixed gas is sprayed with deionized water as a washing liquid. After spraying, the fine droplets will increase the contact area with the hexafluoropropylene mixed gas, thereby dissolving the mixed methanol gas. The washing liquid containing methanol falls to the bottom of the water scrubber group 2 under the action of gravity, and the hexafluoropropylene gas after washing is input into the dehydrator 4 for dehydration treatment; the feed end and the discharge end of the circulation component 3 are both connected to the water scrubber group 2. The methanol-containing washing liquid after spraying has not reached saturation and can be reused to absorb more methanol. The washing liquid is transported to the top of the washing tower group 2 through the circulation component 3, and then repeatedly sprayed by the washing tower group 2, which can save resources while ensuring the methanol removal effect; the dehydrator 4 can be a frozen dehydration, a compression dehydration, or a desiccant dehydration. Preferably, the dehydrator 4 in this embodiment is a frozen dehydrator, and the dehydrator 4 is connected to the gas outlet end of the washing tower group 2 to freeze and dehydrate the treated hexafluoropropylene mixed gas, and the dehydrated hexafluoropropylene mixed gas is input into the qualified product tank 5 for storage; the qualified product tank 5 is connected to the gas outlet end of the dehydrator 4, and is used to hold the dehydrated hexafluoropropylene mixed gas, and the qualified product tank 5 can be any gas storage container.

[0050] In this embodiment, the crude product tank 1 is input into the water washing tower group 2 for repeated water washing. The number of water washings can be 2 times, 3 times, 5 times or any number of times. Through repeated water washing, the gas is fully contacted with the water washing liquid to remove methanol. The mixed gas after the removal of methanol is dehydrated by the dehydrator 4 to obtain purified hexafluoropropylene.

[0051] In some embodiments, reference Figure 1The water washing tower group 2 includes an air inlet pipe 25, a first water washing tower 21, an air delivery pipe 26, a second water washing tower 22, an exhaust pipe 27, a sprayer 29, a first liquid inlet pipe 23 and a second liquid inlet pipe 24. The air inlet pipe 25 is connected to the discharge end of the crude product tank 1, and is used to transport the hexafluoropropylene mixed gas in the crude product tank 1 to the first water washing tower 21 for treatment. Preferably, a valve is installed on the air inlet pipe 25; the middle section of the first water washing tower 21 is connected to the air inlet pipe 25, and the input hexafluoropropylene mixed gas enters from the middle section, while the washing liquid is sprinkled from the top by the sprayer 29. The upper section of the first water washing tower 21 is relatively long, which can ensure that the washing liquid and the hexafluoropropylene mixed gas are fully in contact. The hexafluoropropylene mixed gas after water washing will rise to the top of the first water washing tower 21 and be output to the air delivery pipe 26; the air delivery pipe 26 is connected to the gas outlet end of the first water washing tower 21, refer to Figure 1It can be seen that the gas outlet end is the top of the first water washing tower 21, and the gas pipe 26 is connected to the middle section of the second water washing tower 22, which is used to output the initially treated hexafluoropropylene mixed gas to the second water washing tower 22 for reprocessing, and a valve is installed on it; the middle section of the second water washing tower 22 is connected to the gas pipe 26, and most of the methanol in the hexafluoropropylene mixed gas treated by the first water washing tower 21 has been removed. After the second water washing in the second water washing tower 22, the small amount of methanol contained therein can be separated again, so that the methanol content in the hexafluoropropylene mixed gas is 0.2-0.3 mg / L. The hexafluoropropylene mixed gas will be discharged from the top of the second water washing tower 22 to the exhaust pipe 27; the exhaust pipe 27 is connected to the top of the second water washing tower 22 and the dehydrator 4 respectively, and is used to send the hexafluoropropylene mixed gas after the methanol is removed into the dehydrator 4 for dehydration, and a valve is installed on it; the first liquid inlet pipe 23 is connected to the middle section of the first water washing tower 21, and the first liquid inlet pipe 23 is connected to an external water source to input external deionized water into the first water washing tower 21, and the connection position of the first liquid inlet pipe 23 and the first water washing tower 21 is higher than the connection position of the air inlet pipe 25 and the first water washing tower 21, which can ensure that the input washing liquid is The hexafluoropropylene mixed gas is first treated, and the treated water falls into the bottom of the first water washing tower 21. The water is transported to the top of the first water washing tower 21 by the circulation component 3, and then sprayed by the sprayer 29 located in the first water washing tower 21 to separate the hexafluoropropylene mixed gas again. A valve is installed on it; the second liquid inlet pipe 24 is connected to the middle section of the second water washing tower 22, and the connection position of the second liquid inlet pipe 24 and the second water washing tower 22 is higher than the connection position of the gas delivery pipe 26 and the second water washing tower 22, which can ensure that the input water washing liquid treats the hexafluoropropylene mixed gas again, and the treated water falls into the first water washing tower 21. At the bottom of the second water washing tower 22, water is transported to the top of the second water washing tower 22 by the circulation component 3, and then sprayed by the sprayer 29 located in the second water washing tower 22 to separate the hexafluoropropylene mixed gas again, on which a valve is installed; there are multiple sprayers 29, preferably, the sprayer 29 is the same as the conventional sprayer, and can spray water in the form of fine liquid droplets, thereby increasing the contact area between the liquid droplets and the hexafluoropropylene mixed gas, thereby improving the absorption efficiency of methanol. The number of sprayers 29 is preferably 2, and the two sprayers 29 are respectively installed in the first water washing tower 21 and the second water washing tower 22.

[0052] In this embodiment, valves are provided on the air inlet pipe 25, the air delivery pipe 26, the exhaust pipe 27, the first liquid inlet pipe 23 and the second liquid inlet pipe 24 to control the on-off of the pipes. The first liquid inlet pipe 23 and the second liquid inlet pipe 24 are used to add deionized water.

[0053] Preferably, the gas outlet end of the first water washing tower 21 and the gas inlet end of the first water washing tower 21 are connected by a pipeline, and the hexafluoropropylene mixed gas can be repeatedly washed with water in the first water washing tower 21 when multiple water washings are required. More preferably, a valve is provided on the pipeline to control whether repeated water washing is performed.

[0054] Preferably, the gas outlet end of the second water washing tower 22 and the gas inlet end of the second water washing tower 22 are connected by a pipeline, and the hexafluoropropylene mixed gas can be repeatedly washed with water in the second water washing tower 22 when multiple water washings are required. More preferably, a valve is provided on the pipeline to control whether repeated water washing is performed.

[0055] In some embodiments, reference Figure 1 The liquid outlet end of the dehydrator 4 is connected to the top of the second water washing tower 22 through the first liquid return pipe 28. A valve is installed on the first liquid return pipe 28. After dehydration by the dehydrator 4, the washing liquid will be collected in the dehydrator 4. By connecting the dehydrator 4 to the top of the second water washing tower 22, the used washing liquid can be returned to the second water washing tower 22 for reuse, thereby improving the utilization rate of water.

[0056] In some embodiments, reference Figure 1 The circulation assembly 3 includes a first circulation pipe 31, a first circulation pump 32, a second circulation pipe 33 and a second circulation pump 34. The two ends of the first circulation pipe 31 are respectively connected to the sprayer 29 of the first water washing tower 21 and the liquid outlet end of the first water washing tower 21, so that the washing liquid at the bottom of the first water washing tower 21 can be transported to the top of the first water washing tower 21 and sprayed out by the sprayer 29 in the first water washing tower 21. A valve is installed on the first circulation pipe 31; the first circulation pump 32 is installed on the first circulation pipe 31, and is used to extract the washing liquid in the first water washing tower 21 to the top of the first water washing tower 21 to wash the hexafluoropropylene mixed gas with water; the second circulation pipe 31 is connected to the first water washing tower 21 and the washing liquid is pumped to the top of the first water washing tower 21 to wash the hexafluoropropylene mixed gas with water; The two ends of the ring pipe 33 are respectively connected to the sprayer 29 of the second water washing tower 22 and the liquid outlet end of the second water washing tower 22, so that the washing liquid at the bottom of the second water washing tower 22 can be transported to the top of the second water washing tower 22, and sprayed through the sprayer 29 in the second water washing tower 22. A valve is installed on the second circulation pipe 33; the second circulation pump 34 is installed on the second circulation pipe 33, and is used to extract the washing liquid in the second water washing tower 22 to the top of the second water washing tower 22 to wash the hexafluoropropylene mixed gas again.

[0057] In this embodiment, the washing liquid at the bottom of the first washing tower 21 and the second washing tower 22 is transported to the sprayer 29 for spraying, so that the washing liquid can be reused. The inventors have found through research that replacing the washing liquid once every 10 tons of hexafluoropropylene processed is the best option, which can ensure the methanol removal effect while ensuring the full utilization of water resources.

[0058] In some embodiments, reference Figure 1The first circulation pipe 31 and the second circulation pipe 33 are both connected to the waste liquid discharge pipe 35. After processing enough hexafluoropropylene, the methanol in the washing liquid tends to be saturated. At this time, in order to ensure the processing efficiency of the system, the washing liquid in the first water washing tower 21 and the second water washing tower 22 can be output to the waste liquid discharge pipe 35 through the first circulation pipe 31 and the second circulation pipe 33 respectively, and then collected in the waste liquid pool. Valves are installed on the first circulation pipe 31 and the second circulation pipe 33.

[0059] In this embodiment, valves are installed on the first circulation pipe 31, the second circulation pipe 33 and the waste liquid discharge pipe 35 to control the opening and closing of each pipe.

[0060] In some embodiments, reference Figure 1 The first circulation pipe 31 and the second circulation pipe 33 are both sleeved with a heating jacket 36, and the heating jacket 26 can ensure the heating effect of the first circulation pipe 31 and the second circulation pipe 33, so that the temperature of the water washing liquid in the first circulation pipe 31 and the second circulation pipe 33 is about 30°C. The heating jacket 36 can be electric heating, water bath heating, sand bath heating or other heating methods. Preferably, it can be steam circulation heating, and the heated steam is recycled after being discharged, so that the first circulation pipe 31 and the second circulation pipe 33 sleeved in the heating jacket 36 absorb heat, ensuring that the temperature of the internal water washing liquid is high, avoiding the liquefaction of the hexafluoropropylene material, and ensuring the full collection of hexafluoropropylene.

[0061] In some embodiments, flow meters 37 are installed on the first circulation pipe 31 and the second circulation pipe 33 to facilitate observation of the flow rate of the washing liquid.

[0062] In some embodiments, pressure gauges 38 are installed on the first circulation pipe 31 and the second circulation pipe 33 to facilitate observation of the pressure of the washing liquid.

[0063] In some embodiments, a dehydration buffer tank 6 is connected between the dehydrator 4 and the qualified product tank 5. The liquid outlet valve of the dehydration buffer tank 6 is closed during the operation of the system, and the liquid outlet valve is opened during the water replacement of the second water washing tower 22, and the water is discharged synchronously. The dehydration buffer tank 6 is used to hold the dehydrated gas, and the dehydrated gas treated by the dehydrator 4 is dehydrated again. The dehydration of the dehydration buffer tank 6 is specifically through the combined effect of gas pressure and weight, and the gas is dehydrated again to ensure the separation effect of hexafluoropropylene, and then the dehydrated gas is transported to the qualified product tank 5 for storage. The gas treated by the dehydrator 4 is transported to the dehydration buffer tank 6 through the first gas storage pipe 61 for storage. The gas outlet end of the dehydration buffer tank 6 is connected to the qualified product tank 5 through the second gas storage pipe 62, and the liquid outlet end of the dehydration buffer tank 6 is connected to the second water washing tower 22 through the second liquid return pipe 63. Preferably, the end of the first gas storage pipe 61 extends into the dehydration buffer tank 6 by 0.5 to 1.5 m, so that the gas can enter the dehydration buffer tank 6.

[0064] In this embodiment, valves are installed on the first gas storage pipe 61, the second gas storage pipe 62 and the second liquid return pipe 63 to facilitate the on-off control of each pipeline.

[0065] In some embodiments, the air inlet pipe 25 and the air delivery pipe 26 are respectively connected with an air extraction pipe 251, and the air extraction pipe 251 is used to extract oxygen from the first water washing tower 21 and the second water washing tower 22. When necessary, the oxygen in the first water washing tower 21 and the second water washing tower 22 can be extracted by an air pump, and external nitrogen can also be injected into the first water washing tower 21 and the second water washing tower 22. Preferably, a valve is installed on the air extraction pipe 251. In actual operation, the air inlet pipe 25 and the air delivery pipe 26 can be evacuated twice respectively through the air extraction pipe 251, and then nitrogen can be injected twice, so that the oxygen content in the system is less than 50ppm, which is convenient for the subsequent high-quality production of perfluoroethylene propylene resin, fluororubber, etc.

[0066] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A system for removing methanol from hexafluoropropylene, characterized in that: include Crude product tank, used to contain hexafluoropropylene mixed gas; A water washing tower group, used for washing and removing methanol in the hexafluoropropylene mixed gas, connected to the crude product tank; A circulation component, used for recycling the water washing liquid used by the water washing tower group, wherein both the feed end and the discharge end are connected to the water washing tower group; A dehydrator, used for dehydrating the hexafluoropropylene mixed gas after being treated by the water scrubber group, and connected to the discharge port of the water scrubber group; The qualified product tank is used to contain the dehydrated hexafluoropropylene mixed gas and is connected to the dehydrator.

2. A system for removing methanol from hexafluoropropylene according to claim 1, characterized in that: The water washing tower group includes an air inlet pipe, a first water washing tower, an air delivery pipe, a second water washing tower, an exhaust pipe, a sprayer, a first liquid inlet pipe and a second liquid inlet pipe. The air inlet pipe is connected to the discharge end of the crude product tank and is used to transport the hexafluoropropylene mixed gas; The middle section of the first water washing tower is connected to the air inlet pipe and is used for initially treating the hexafluoropropylene mixed gas; The gas delivery pipe is connected to the gas outlet end of the first water scrubber and is used to output the initially treated hexafluoropropylene mixed gas; The middle section of the second water scrubber is connected to the gas pipeline for reprocessing the initially treated hexafluoropropylene mixed gas; The exhaust pipe is connected to the gas outlet of the second water washing tower and the dehydrator respectively, and is used to send the hexafluoropropylene mixed gas after methanol removal to the dehydrator for dehydration; The first liquid inlet pipe is connected to the middle section of the first water washing tower and is used to input the external washing liquid into the first water washing tower; The second liquid inlet pipe is connected to the middle section of the second water washing tower and is used to input the external water washing liquid into the second water washing tower; There are multiple sprayers, and the multiple sprayers are respectively installed in the first water washing tower and the second water washing tower.

3. A system for removing methanol from hexafluoropropylene according to claim 2, characterized in that: The liquid outlet end of the dehydrator is connected to the top of the second water washing tower through a first liquid return pipe.

4. A system for removing methanol from hexafluoropropylene according to claim 2, characterized in that: The circulation assembly includes a first circulation pipe, a first circulation pump, a second circulation pipe and a second circulation pump, The two ends of the first circulation pipe are respectively connected to the sprayer of the first water washing tower and the liquid outlet of the first water washing tower; The first circulation pump is installed on the first circulation pipe, and is used to pump the washing liquid in the first water washing tower to the top of the first water washing tower to wash the hexafluoropropylene mixed gas with water; Both ends of the second circulation pipe are respectively connected to the sprayer of the second water washing tower and the liquid outlet end of the second water washing tower; The second circulation pump is installed on the second circulation pipe, and is used to pump the washing liquid in the second water washing tower to the top of the second water washing tower to wash the hexafluoropropylene mixed gas again.

5. A system for removing methanol from hexafluoropropylene according to claim 4, characterized in that: The first circulation pipe and the second circulation pipe are both connected to the waste liquid discharge pipe.

6. A system for removing methanol from hexafluoropropylene according to claim 4, characterized in that: The first circulation pipe and the second circulation pipe are both provided with heating jackets.

7. A system for removing methanol from hexafluoropropylene according to claim 4, characterized in that: Flow meters are installed on both the first circulation pipe and the second circulation pipe.

8. A system for removing methanol from hexafluoropropylene according to claim 4, characterized in that: The first circulation pipe and the second circulation pipe are both equipped with pressure gauges.

9. A system for removing methanol from hexafluoropropylene according to claim 4, characterized in that: A dehydration buffer tank is connected between the dehydrator and the qualified product tank, the air outlet end of the dehydrator is connected to the air inlet end of the dehydration buffer tank through a first air storage pipe, the air outlet end of the dehydration buffer tank is connected to the qualified product tank through a second air storage pipe, and the liquid outlet end of the dehydration buffer tank is connected to the second water washing tower through a second liquid return pipe.

10. A system for removing methanol from hexafluoropropylene according to claim 2, characterized in that: The air inlet pipe and the air delivery pipe are respectively connected with air extraction pipes, and the air extraction pipes are used to extract oxygen from the first water scrubber and the second water scrubber.

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