Sodium impurity removal refining device and refining method

Abstract

The invention provides a sodium impurity removal refining device and a refining method.The device comprises a refining tank, a sodium storage layer, an impurity detection device and a circulating pump, an opening matched with the sodium storage layer in outer contour is formed in the side wall of the refining tank, a horizontal support is arranged in the refining tank, and the sodium storage layer is arranged in the horizontal support; the horizontal support and the lower edge of the opening are located on the same horizontal line and used for supporting the sodium storage layer, the sodium storage layer is composed of a tower plate with dense holes, the tower plate is filled with metal sodium, a movable baffle is arranged on the bottom face of the tower plate, a circulating feeding port is formed in the top of the refining tank, and a liquid outlet is formed in the bottom of the refining tank. The liquid outlet is communicated with the circulating feed port through a circulating pipeline, and the impurity detection device and the circulating pump are arranged on the circulating pipeline. The invention solves the problems that the metal sodium is improperly stored, the consumption condition of the metal sodium is difficult to observe and the metal sodium is difficult to replace when the metal sodium is used for removing impurities.

Description

Technical Field

[0001] The present invention belongs to the technical field of raw material refining, and particularly relates to a sodium impurity removal and refining device and a refining method. Background Art

[0002] The raw material refining process is an essential step in laboratory and industrial polymerization tests. It is mainly to reduce the content of impurities such as water, sulfur, oxygen, carbon monoxide, and unsaturated hydrocarbons in the raw materials, improve the purity of the raw materials, meet the production index requirements, and avoid adverse effects on the polymerization reaction. Industrially, there are mainly four categories of polyethylene production methods: high-pressure gas-phase method, solution method, and slurry method processes. The PE resins produced by different polymerization process routes have different characteristics and application ranges. In the solution method process, the polymer is dissolved in a solvent. The greatest advantage of the solution method process is the short product switching time, low gel content in the film material, the ability to produce a full range of products (molecular weight distribution from narrow to wide distribution), and very low density polyethylene (i.e., VLDPE, such as PE plastomers and elastomers), and it can copolymerize with higher alpha-olefins, showing excellent strength, toughness, and sealing properties. In the production process of the chemical industry, the solution method process has strict requirements on the water content of the liquid chemical raw materials used in the production process. The raw material substances contain impurities such as water, oxygen, and carbon monoxide, resulting in the raw material purity not meeting the polymerization index requirements. Especially in the solution polymerization process, higher requirements are put forward for the purity of the raw materials. Based on this, the raw material refining process is very important.

[0003] The presence of impurities in the raw materials seriously affects the progress of the polymerization reaction. Water can cause hydrolysis reactions of the main catalyst titanium trichloride and the activator triethylaluminum, directly deactivating the main catalyst. The principle of the deactivation of the activator triethylaluminum: Al(C 2 H 5 ) 3 +H 2 O→Al(OH) 3 +C 2 H 6 . When the main catalyst encounters water, hydrolysis occurs and the deactivation process is as follows: TiCl 3 +H 2 O→Ti(OH) 3 +HCl. Therefore, the water content in the raw materials must be effectively controlled. The presence of water also affects the progress of the polymerization reaction, causing chain termination of the reaction. The presence of oxygen in the raw materials undergoes an oxidation-reduction reaction with the highly efficient main catalyst, poisoning it and directly affecting the progress of the polymerization reaction. The poisoning mechanism is as follows: TiCl 3 +O 2 →TiOCl 2 +TiCl 4 , TiOCl 2 →TiCl 4 +TiO ，The presence of oxygen not only seriously affects the reaction activity of the main catalyst, but also directly affects the progress of the polymerization reaction after entering the reactor, causing chain termination of the polymerization reaction. In chemical raw materials, the presence of CO and CO 2 not only affects the stereospecificity of the catalyst, but also causes chain termination of the polymerization reaction during the polymerization process, reducing the reaction activity of the catalyst.

[0004] Purification using metallic sodium takes advantage of the highly reactive chemical properties of metallic sodium. The outermost layer of a sodium atom has only one electron, which is very easily lost, so it has strong reducibility. Therefore, the chemical properties of sodium are very active, and it can react with a large number of inorganic substances, most non-metallic elements, and most organic substances. When undergoing redox reactions with other substances, it acts as a reducing agent. However, determining the consumption of metallic sodium and replacing metallic sodium are currently difficult technical problems to solve.

[0005] CN106862579A discloses a sodium reduction device with a heat insulation layer, including a reaction chamber, a furnace cover, a reaction furnace, a furnace shell, heating wires, a sodium storage tank, a stirring motor, a sodium reflux condenser, a waste sodium storage tank, and a vacuum pump. A reaction chamber is arranged inside the reaction furnace, a furnace shell is arranged outside the reaction furnace, a furnace cover is arranged above the reaction furnace, heating wires are arranged at the bottom and sides of the reaction furnace, and a stirring motor is arranged above the furnace cover. This patent does not provide good protection for the active metallic sodium. The chemical properties of metallic sodium are extremely active, and it is extremely prone to chemical reactions and even combustion and explosion, and it needs to be stored in media such as liquid paraffin or kerosene. This method has the drawback of dangerous operation. Summary of the Invention

[0006] The purpose of the present invention is to provide a sodium purification and refining device to solve the problems in the prior art that metallic sodium is not properly stored, it is difficult to observe the consumption of metallic sodium, and it is difficult to replace metallic sodium when removing impurities with metallic sodium.

[0007] The purpose of the present invention also lies in providing a sodium purification and refining method.

[0008] To achieve the above purpose, the present invention provides a sodium purification and refining device, including a refining tank, a sodium storage layer, an impurity detection device, and a circulation pump. An opening matching the outer contour of the sodium storage layer is provided on the side wall of the refining tank. A horizontal support is arranged inside the refining tank, and the horizontal support is on the same horizontal line as the lower edge of the opening for supporting the sodium storage layer. The sodium storage layer is composed of trays containing dense pores, metallic sodium is filled in the trays, a movable baffle is arranged on the bottom surface of the trays, a circulating feed port is arranged at the top of the refining tank, a liquid outlet is arranged at the bottom, and the liquid outlet and the circulating feed port are connected through a circulation pipeline. The impurity detection device and the circulation pump are arranged on the circulation pipeline.

[0009] For the sodium impurity removal and purification device described in the present invention, a liquid inlet, an inert gas inlet, and an exhaust port are provided at the top of the purification tank.

[0010] For the sodium impurity removal and purification device described in the present invention, the sodium storage layer is single-layer or multi-layer.

[0011] For the sodium impurity removal and purification device described in the present invention, the sodium storage layer is cylindrical, cuboid, or quarter-cylindrical.

[0012] For the sodium impurity removal and purification device described in the present invention, the sodium storage layer further contains a storage medium for storing metallic sodium.

[0013] For the sodium impurity removal and purification device described in the present invention, the storage medium is one or several of liquid paraffin, kerosene, mineral oil, and benzene series.

[0014] To achieve the above object, the present invention also provides a sodium impurity removal and purification method. Using the device described in any one of claims 1-5, the sodium storage layer is placed in the purification tank through the opening on the side wall of the purification tank. Inert gas is introduced into the purification tank through the inert gas inlet to displace the air in the purification tank. Then, the baffle at the bottom of the sodium storage layer is withdrawn, and the liquid to be treated is input into the purification tank through the liquid inlet. The liquid to be treated flows out from the liquid outlet after passing through the sodium storage layer. The treated liquid is detected by an impurity detection device. If it meets the standard, it is discharged for use. If it does not meet the standard, it is recycled to the circulation feed port through a circulation pump for further treatment.

[0015] Advantages of the present invention:

[0016] The sodium storage layer of the device of the present invention can accommodate metallic sodium and the storage medium of metallic sodium, and can well protect metallic sodium from reacting with substances in the external air at the beginning of the reaction, avoiding the risk of combustion and explosion. Moreover, the sodium storage layer is movably installed in the purification tank, which is convenient to replace. Through the impurity detection device, the usage of sodium in the sodium storage layer can also be observed in a timely manner, so as to determine the purification effect and the remaining amount of the purification agent, without expensive special instruments.

[0017] Using the device described in the present invention, the impurities in the raw material to be purified are removed by making the impurities in the raw material to be purified react chemically with metallic sodium in the purification device to form sodium compounds, so that the purified raw material meets the specification requirements for the polymerization test. Description of the drawings

[0018] Figure 1 It is a schematic structural diagram of the sodium impurity removal and purification device described in the present invention.

[0019] In the figure, reference numerals:

[0020] 1. Purification tank;

[0021] 12. Circulation feed port

[0022] 13. Liquid outlet

[0023] 14. Sodium storage layer

[0024] 15. Liquid inlet

[0025] 16. Exhaust port

[0026] 17. Inert gas inlet

[0027] 2. Impurity detection device

[0028] 3. Circulation pump Specific embodiments

[0029] The present invention will be specifically described below through embodiments. It is necessary to point out here that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention according to the above content of the present invention.

[0030] Figure 1 It is a schematic structural diagram of the sodium deimpurity and refining device described in the present invention. Please refer to Figure 1, a sodium decontamination and refining device provided by the present invention includes a refining tank, a sodium storage layer, an impurity detection device, and a circulation pump. The refining tank can be a common barrel-shaped tank body in the art. The top of the refining tank is provided with a liquid inlet, a circulation feed inlet, an inert gas input port, and an exhaust port, and the bottom is provided with a liquid outlet. The liquid outlet and the circulation feed inlet are connected through a circulation pipeline. The impurity detection device and the circulation pump are arranged on the circulation pipeline. An opening matching the outer contour of the sodium storage layer is provided on the side wall of the refining tank. The outer contour of the sodium storage layer can be the same as the contour of the refining tank body. For example, if the refining tank body is cylindrical, the sodium storage layer is cylindrical, and the opening on the side wall of the refining tank is also a cylindrical opening of the same size as the sodium storage layer. This structure can increase the contact area between the liquid to be treated and the sodium storage layer, but it is not easy to fix or seal. The outer contour of the sodium storage layer can also be rectangular parallelepiped-shaped, and the opening on the side wall of the refining tank only needs to be consistent with the short side side of the rectangular parallelepiped, which can reduce the opening area. This method is beneficial to the sealing of the tank body, but the contact area between the liquid to be treated and the sodium storage layer will be limited. The most preferred sodium storage layer is a quarter-cylindrical shape. Four quarter-cylindrical sodium storage layers on the same horizontal plane are combined into a large cylindrical sodium storage layer, which can have the largest contact area and is also convenient for installation and replacement. A horizontal support is provided in the refining tank. The horizontal support is on the same horizontal line as the lower edge of the opening for supporting the sodium storage layer. After the sodium storage layer is placed in the refining tank through the opening, it is placed on the horizontal support. The sodium storage layer is used to store metallic sodium, and the metallic sodium can be in the form of blocks, strips, filaments, or spheres. The sodium storage layer is composed of a tray containing dense pores, and the tray is filled with metallic sodium. Preferably, a storage medium for storing metallic sodium is further included in the sodium storage layer to prevent unnecessary reactions of sodium, such as reacting with reactive gases in the air before being installed in the refining tank or before the air in the refining tank is exhausted. A movable baffle is provided on the bottom surface of the tray. The movable baffle is a flat plate without pores and is used to prevent the loss of the storage medium..

[0031] In a specific embodiment, the sodium storage layer is multiple layers, such as two layers, three layers, or four layers, and the specific number of layers can be determined according to the actual use situation.

[0032] In a specific embodiment, the storage medium is one or more of liquid paraffin, kerosene, mineral oil, and benzene series substances.

[0033] Use Figure 1When the device shown is used for the method of sodium purification and impurity removal, first, the sodium storage layer containing metallic sodium and a storage medium is placed into the purification tank through the opening on the side wall of the purification tank. An inert gas is introduced into the purification tank through the inert gas inlet. Specifically, it can be nitrogen to displace the air in the purification tank. Then, the baffle at the bottom of the sodium storage layer is withdrawn to drain the liquid storage medium, exposing the metallic sodium to facilitate the reaction with the impurities in the liquid to be treated. Then, the liquid to be treated is introduced into the purification tank through the liquid inlet. The liquid to be treated is a substance whose main component does not react with metallic sodium, but the impurities in it can react with metallic sodium. The impurities are usually trace amounts of water, carbon dioxide, etc. The liquid to be treated flows into the sodium storage layer from the liquid inlet, and after being treated by the metallic sodium in the sodium storage layer, it flows out from the liquid outlet. The treated liquid is detected by an impurity detection device. If it meets the standard, it is discharged for use. If it does not meet the standard, it is recycled to the circulation feed port through a circulation pump for further treatment. If there is no obvious change in the impurity detection device, it can be considered to judge whether the metallic sodium has been consumed. At this time, the sodium storage layer can be taken out through the opening on the side wall for inspection or replacement.

[0034] Certainly, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention. However, these corresponding changes and deformations should all fall within the protection scope of the claims of the present invention.

Claims

1. A sodium decontamination and refining device, It is characterized in that It includes a refining tank, a sodium storage layer, an impurity detection device, and a circulation pump. The side wall of the refining tank is provided with an opening that matches the outer contour of the sodium storage layer. A horizontal bracket is provided in the refining tank. The horizontal bracket and the lower edge of the opening are on the same horizontal line for supporting the sodium storage layer. The sodium storage layer is composed of a tower plate containing dense holes. The tower plate is filled with metallic sodium. A movable baffle is provided on the bottom surface of the tower plate. A circulation feed port is provided on the top of the refining tank, and a liquid outlet is provided on the bottom. The liquid outlet and the circulation feed port are connected through a circulation pipeline. The impurity detection device and the circulation pump are arranged on the circulation pipeline.

2. The sodium impurity removal and refining device according to claim 1, It is characterized in that The top of the refining tank is provided with a liquid inlet, an inert gas input port and an exhaust port.

3. The sodium impurity removal and refining device according to claim 1, It is characterized in that The sodium storage layer is a single layer or multiple layers.

4. The sodium impurity removal and refining device according to claim 1, It is characterized in that The sodium storage layer is in the shape of a cylinder, a cuboid or a quarter cylinder.

5. The sodium impurity removal and refining device according to claim 1, It is characterized in that The sodium storage layer also contains a storage medium for storing metallic sodium.

6. The sodium removal and refining device according to claim 4, It is characterized in that The storage medium is one or more of liquid paraffin, kerosene, mineral oil and benzene series.

7. A sodium removal and refining method, It is characterized in that Using the device described in any one of claims 1 to 6, a sodium storage layer is placed in a refining tank through an opening in the side wall of the refining tank, an inert gas is introduced into the refining tank through an inert gas inlet to replace the air in the refining tank, and then the baffle at the bottom of the sodium storage layer is withdrawn, and liquid to be treated is introduced into the refining tank through a liquid inlet. The liquid to be treated flows out from a liquid outlet after being treated by the sodium storage layer. The treated liquid is detected by an impurity detection device, and if it meets the standard, it is discharged for standby use. If it does not meet the standard, it is circulated to the circulating feed inlet again through a circulating pump for further treatment.

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