Sodium methoxide production device and production method

Abstract

The present application discloses a sodium methoxide production device and production method, including an alkali dissolving tank, a reaction tower, and a distillation tower. A first buffer tank, a solid-liquid separation device, and a second buffer tank are provided between the alkali dissolving tank and the reaction tower. A first liquid phase pipeline is connected between the bottom of the alkali dissolving tank and the top of the first buffer tank, a second liquid phase pipeline is connected between the first buffer tank and the second buffer tank, the solid-liquid separation device is installed on the second liquid phase pipeline, and a third liquid phase pipeline is connected between the second buffer tank and the reaction tower; a methanol feed pipe is connected to the top of the distillation tower, a first gas phase pipeline is connected between the top of the distillation tower and the bottom of the reaction tower, and a second gas phase pipeline is connected between the top of the reaction tower and the waist of the distillation tower; a connecting pipe is connected between the waist of the first buffer tank and the top of the second buffer tank, and the connecting pipe is provided with an on-off control valve. By providing a connecting pipe for conveying methanol alkali solution, the present application can ensure the methanol alkali conveying demand of the solid-liquid separation device during overhaul or maintenance.

Description

Technical Field

[0001] The present application relates to the field of preparation of organic chemical products, and in particular to a sodium methoxide production device and production method. Background Art

[0002] Sodium methoxide, an organic compound with the chemical formula CH₃ONa, is a hazardous chemical that is corrosive and pyrophoric. It is primarily used in the pharmaceutical industry, as a condensation agent in organic synthesis, a chemical reagent, and a catalyst for edible oil processing.

[0003] Currently, there are two methods for producing sodium methoxide: the sodium method and the alkaline method. The sodium method includes the metallic sodium method and the sodium-based sodium method. The sodium-based method cannot be used for industrial production and has no industrial value. The metallic sodium method is too expensive and poses certain safety risks, making it unsuitable for large-scale production of sodium methoxide. Therefore, the alkaline method is the main method for the industrial production of sodium methoxide.

[0004] The alkaline process for preparing sodium methoxide primarily includes alkali dissolution, synthesis, and methanol distillation recovery. To dissolve the alkali, solid alkali is hammered into blocks and placed in a alkali dissolution tank. Industrial methanol is pumped into the alkali dissolution tank, and the circulating pump and agitator are operated to control the temperature. When the NaOH content in the methanol reaches the required level, circulation and agitation are stopped, and the solution is discharged into a precipitation tank to allow impurities such as Na2CO3 and NaCl to settle. After stagnant conditions, it is used as the alkali solution for the synthesis process.

[0005] Impurities in the mixed solution of NaOH and methanol can also be removed by solid-liquid separation equipment. The methanol alkaline solution after impurities are removed is discharged into a storage container and can be used at any time without waiting for precipitation, which is relatively efficient and quick. However, compared with the precipitation method, the solid-liquid separation equipment sometimes needs to be shut down for inspection or maintenance during operation, and the repair or maintenance of the solid-liquid separation equipment will affect the production process of sodium methoxide. Summary of the Invention

[0006] In order to reduce the impact of shutdown of solid-liquid separation equipment used to separate precipitates in methanol alkaline solution on sodium methoxide production, the present application provides a sodium methoxide production device and production method.

[0007] The present application provides a sodium methoxide production device and production method using the following technical solutions:

[0008] A sodium methoxide production device comprises an alkali dissolving tank, a reaction tower and a distillation tower, wherein a first cache tank, a solid-liquid separation device and a second cache tank are provided between the alkali dissolving tank and the reaction tower, a first liquid phase pipeline is connected between the bottom of the alkali dissolving tank and the top of the first cache tank, a second liquid phase pipeline is connected between the first cache tank and the second cache tank, the solid-liquid separation device is installed on the second liquid phase pipeline, a third liquid phase pipeline is connected between the second cache tank and the reaction tower, and a discharge pipe is provided at the bottom of the reaction tower; a methanol feed pipe is connected to the top of the distillation tower, a first gas phase pipeline is connected between the top of the distillation tower and the bottom of the reaction tower, a second gas phase pipeline is connected between the top of the reaction tower and the waist of the distillation tower; a connecting pipe is connected between the waist of the first cache tank and the top of the second cache tank, and the connecting pipe is provided with a switch control valve, and the switch control valve is used to control the on-off of the connecting pipe.

[0009] By adopting the above technical solution, methanol and sodium hydroxide are dissolved in the alkali dissolving tank. After the methanol alkali solution in the alkali dissolving tank is mixed, it is temporarily stored in the first buffer tank. After solid-liquid separation in the solid-liquid separation equipment, the methanol alkali solution in the first buffer tank flows into the second buffer tank. During this process, the three-way valve is switched to a state where the bypass pipe is connected to the connecting pipe, and the three-way valve controls the connecting pipe to be in a closed state. When the solid-liquid separation equipment needs to be repaired or maintained, the solid-liquid separation equipment suspends operation. After the methanol alkali solution is discharged from the alkali dissolving tank, the first buffer tank separates the impurities in the methanol alkali by precipitation separation. During this process, the liquid level of the methanol alkali solution in the first buffer tank is maintained at a position slightly lower than the upper end of the bypass pipe. When the methanol alkali solution is precipitated and separated, the three-way valve is switched to a state where the connecting pipe is in a pass state, so that the methanol alkali solution in the first buffer tank flows to the second buffer tank through the connecting pipe. The methanol alkali solution between the first and second buffer tanks can be transported through the solid-liquid separation equipment or through the connecting pipe. The second liquid phase pipeline equipped with the solid-liquid separation equipment serves as the main conveying path between the first buffer tank and the second buffer tank, while the connecting pipe serves as the auxiliary conveying path between the first buffer tank and the second buffer tank to ensure the methanol alkali conveying demand of the solid-liquid separation equipment during the overhaul or maintenance. Compared with the method of adding solid-liquid separation equipment, the first buffer tank combined with the connecting pipe can meet the temporary conveying demand of methanol alkali solution with a relatively simple structure, which is conducive to reducing the cost of equipment.

[0010] Optionally, the switch control valve is a three-way valve, the bypass port of the three-way valve is connected to a bypass pipe, the end of the bypass pipe away from the three-way valve is connected to the top of the first cache tank, and the bypass pipe is used to connect the end of the connecting pipe away from the first cache tank. When the bypass pipe is connected to the connecting pipe, the connecting pipe is in a closed state. When the three-way valve closes the passage between the bypass pipe and the connecting pipe, the connecting pipe is in a connected state.

[0011] By adopting the above technical solution, when the methanol alkali solution is transported between the first cache tank and the second cache tank through the second liquid phase pipeline, the connecting pipe is closed, and at the same time the bypass pipe is connected to the connecting pipe, so that the top of the first cache tank and the top of the second cache tank are connected through the bypass pipe and the connecting pipe. In this state, when the methanol alkali solution in the first cache tank is discharged into the second cache tank through the solid-liquid separation equipment, the liquid level in the first cache tank decreases and the liquid level in the second cache tank increases, and the gas in the second cache tank is discharged into the second cache tank through the connecting pipe and the bypass pipe, so that the air pressure in the first cache tank and the second cache tank is generally balanced, which is not easy to affect the pump flow of the methanol alkali solution and the solid-liquid separation work of the solid-liquid separation equipment.

[0012] Optionally, an air pressure regulating pipe is connected between the top of the distillation tower and the second cache tank and the top of the distillation tower, and the air pressure regulating pipe is provided with a liquid storage elbow for storing methanol.

[0013] By adopting the above technical solution, under the premise that the top of the first cache tank is connected to the top of the second cache tank through a connecting pipe and a bypass pipe, when the solution in the second cache tank is discharged into the reaction tower, the overall air pressure in the first cache tank and the second cache tank decreases. At this time, part of the methanol gas in the distillation tower is partially discharged into the second cache tank under the action of the pressure difference, thereby increasing the air pressure in the first cache tank and the second cache tank.

[0014] Optionally, an air pressure regulating pipe is connected between the top of the distillation tower and the second cache tank and the top of the distillation tower, and the air pressure regulating pipe is provided with a pressure differential regulating valve.

[0015] By adopting the above technical solution, when the second buffer tank transports the methanol alkali solution to the reaction tower through the third liquid phase pipeline, the overall pressure of the first buffer tank and the second buffer tank decreases, and the methanol gas at the top of the distillation tower can replenish the methanol gas to the first buffer tank and the second buffer tank, reducing the situation where the first buffer tank absorbs external air through the alkali dissolving tank; and since the pressure in the distillation tower is relatively high, a pressure differential regulating valve is provided in the air pressure regulating pipe, and the pressure differential regulating valve can maintain a certain pressure difference between the top of the distillation tower and the second buffer tank, so that the distillation tower will only replenish methanol gas to the second cache tank when the pressure in the second buffer tank decreases.

[0016] Optionally, the air pressure regulating pipe is provided with a liquid storage elbow, which is used to store methanol alkaline solution. The liquid storage elbow is close to the second cache tank relative to the pressure differential regulating valve. The air pressure regulating pipe is provided with an air pressure sensor, which is located between the liquid storage elbow and the pressure differential regulating valve.

[0017] By adopting the above technical solution, the liquid storage elbow can store methanol alkaline solution, and a relatively closed area is formed between the liquid storage elbow and the pressure differential regulating valve. When the pressure differential sensor fails, causing excessive methanol gas in the distillation tower to leak into the air pressure regulating pipe, it can be promptly and remotely notified through the air pressure sensor.

[0018] Optionally, the air pressure regulating tube is connected with a flushing tube, the end of the flushing tube away from the air pressure regulating tube is connected to the methanol feed pipe, the part where the air pressure regulating tube is connected to the flushing tube is higher than the liquid storage elbow, and the flushing tube is provided with a first locking valve.

[0019] By adopting the above technical solution and providing a flushing pipe connected to the methanol feed pipe, the first locking valve can be opened regularly to replace the methanol liquid in the liquid storage elbow, thereby reducing the deterioration of the methanol liquid.

[0020] Optionally, the third liquid phase pipeline is provided with an ejector, an intake pipe is connected between the ejector and the top of the second cache tank, the intake pipe is connected to the intake chamber of the ejector, and the intake pipe is provided with a second locking valve.

[0021] By adopting the above technical solution, under the premise that the first cache tank and the second cache tank are connected, when the alkali dissolving tank discharges methanol alkali solution into the first cache tank, the overall air pressure of the first cache tank and the second cache tank increases. At this time, the second locking valve can be opened, and the third liquid phase pipeline can be used to transport the methanol alkali solution. When the third liquid phase pipeline is transporting the methanol alkali solution, the gas in the second cache tank can be absorbed by the ejector and the suction pipe to reduce the overflow of gas in the first cache tank and the second cache tank.

[0022] Optionally, the first liquid phase pipeline is connected to the bottom of the first cache tank, and a baffle is provided on the inner side of the first cache tank. The upper surface of the baffle is an outwardly convex curved surface. A gap for liquid to pass through is left between the edge of the baffle and the inner circumferential surface of the first cache tank. A height margin is left between the baffle and the bottom of the first cache tank, and the baffle blocks the feed port of the first liquid phase pipeline from top to bottom.

[0023] By adopting the above technical solution, the precipitate in the methanol-alkali solution in the first buffer tank falls on the upper surface of the baffle and slides down along the upper surface of the baffle to the bottom of the first buffer tank. As the methanol-alkali solution is discharged from the bottom of the first buffer tank into the second buffer tank via the second liquid-phase pipeline, the baffle blocks the downward flow of the methanol-alkali solution in the first buffer tank. The upper surface of the baffle directs the flow of the methanol-alkali solution toward the inner circumference of the first buffer tank, causing the liquid flow in the first buffer tank to flow downward along the inner circumference. When the liquid flow reaches the bottom of the first buffer tank, the liquid flow moves from the periphery toward the center, thereby carrying as much precipitate as possible into the second liquid-phase pipeline. In addition, when the methanol-alkali solution in the first buffer tank is transferred from the overflow tank to the second buffer tank, the baffle separates the methanol-alkali solution in the first buffer tank from top to bottom, preventing the precipitate at the bottom of the first buffer tank from floating up.

[0024] Optionally, a plurality of guide vanes are provided on the upper surface of the baffle, and the guide vanes are arranged in an array around the central circumference of the baffle, and the guide vanes are used to form a swirl of liquid on the surface of the baffle.

[0025] By adopting the above technical solution, the guide vanes can cause the liquid on the upper surface of the baffle to form a vortex, so that the liquid flow in the first cache tank flows from top to bottom in a vortex manner to the bottom of the first cache tank, making the sediment at the bottom of the first cache tank easier to be carried away by the liquid flow.

[0026] Optionally, the edge profile of the baffle is square, each corner portion of the baffle abuts the bottom of the first cache tank, and a gap is formed between the edge between each two adjacent corners of the baffle and the inner circumference of the first cache tank.

[0027] By adopting the above technical solution, the baffle is supported on the bottom of the first cache tank through the corner portion, which makes installation more convenient.

[0028] The method for producing sodium methoxide using any one of the above sodium methoxide production devices comprises the following steps:

[0029] Step 1: Add methanol and sodium hydroxide into a dissolving tank in proportion, and stir and dissolve the sodium hydroxide into a methanol alkaline solution;

[0030] Step 2: Discharge the methanol alkaline solution in the alkali dissolving tank into the first buffer tank;

[0031] Step 3: Start the solid-liquid separation equipment to separate the methanol liquid in the first buffer tank into solid and liquid and then discharge it into the second buffer tank;

[0032] Step 4: Repeat steps 1-2 to add methanol alkaline solution to the first buffer tank.

[0033] By adopting the above technical solution, by making the first cache tank and the second cache tank store sufficient amounts of methanol alkali solution respectively, when the methanol alkali in the second cache tank is consumed, the first cache tank can be replenished into the second cache tank in time; in addition, during the consumption of the methanol alkali solution in the second cache tank, the methanol alkali solution in the first cache tank obtains a certain precipitation time.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. The methanol-alkali solution between the first and second buffer tanks can be transported either through the solid-liquid separation equipment or through a connecting pipe. The second liquid phase pipeline, equipped with the solid-liquid separation equipment, serves as the primary transport path between the first and second buffer tanks, while the connecting pipe serves as a secondary transport path between the first and second buffer tanks to ensure the methanol-alkali transport needs during the solid-liquid separation equipment overhaul or maintenance.

[0036] 2. When the methanol-alkali solution is transported between the first buffer tank and the second buffer tank through the second liquid phase pipeline, the connecting pipe is closed, and the bypass pipe is connected to the connecting pipe. The air pressure in the first buffer tank and the second buffer tank is generally balanced, which is not easy to affect the pump flow of the methanol-alkali solution and the solid-liquid separation work of the solid-liquid separation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall structure of Example 1.

[0038] Figure 2 This is a schematic diagram of Example 1 used to illustrate the state of the three-way valve controlling the shutoff of the connecting pipe.

[0039] Figure 3 This is a schematic diagram of Example 1 used to illustrate the state of the three-way valve controlling the communication pipe passage.

[0040] Figure 4 This is a longitudinal cross-sectional view of the first cache tank of Example 1.

[0041] Figure 5 It is a horizontal cross-sectional view of the first cache tank of Example 1.

[0042] Figure 6 It is a schematic diagram of the overall structure of Example 2.

[0043] Figure 7 yes Figure 6 A magnified partial view of point A in the middle.

[0044] Description of reference numerals:

[0045] 1. Alkali dissolving tank; 2. Reaction tower; 3. Distillation tower; 4. First buffer tank; 5. Solid-liquid separation equipment; 6. Second buffer tank; 7. Baffle; 71. Guide vane; 11. First liquid phase pipeline; 12. Second liquid phase pipeline; 13. Third liquid phase pipeline; 14. Discharge pipe; 15. Connecting pipe; 151. Switch control valve; 16. Bypass pipe; 17. Flushing pipe; 171. First locking valve; 18. Methanol feed pipe; 21. First gas phase pipeline; 22. Second gas phase pipeline; 23. Air pressure regulating pipe; 231. Pressure differential regulating valve; 232. Liquid storage elbow; 233. Air pressure sensor; 24. Intake pipe; 241. Second locking valve; 242. Ejector. DETAILED DESCRIPTION

[0046] The following is combined with Figure 1-7 This application is described in further detail.

[0047] Example 1

[0048] The present application discloses a sodium methoxide production device and production method. Figure 1 The sodium methoxide production device includes an alkali dissolving tank 1, a reaction tower 2, and a distillation tower 3. A first buffer tank 4, a solid-liquid separation device 5, and a second buffer tank 6 are provided between the alkali dissolving tank 1 and the reaction tower 2. A first liquid phase pipeline 11 is connected between the bottom of the alkali dissolving tank 1 and the top of the first buffer tank 4, a second liquid phase pipeline 12 is connected between the bottom of the first buffer tank 4 and the top of the second buffer tank 6, and the solid-liquid separation device 5 is installed on the second liquid phase pipeline 12. The solid-liquid separation device 5 can specifically be a two-stage pusher centrifuge. A third liquid phase pipeline 13 is connected between the bottom of the second buffer tank 6 and the top of the reaction tower 2, and a discharge pipe 14 is provided at the bottom of the reaction tower 2. A methanol feed pipe 18 is connected to the top of the distillation tower 3, a first gas phase pipeline 21 is connected between the top of the distillation tower 3 and the bottom of the reaction tower 2, and a second gas phase pipeline 22 is connected between the top of the reaction tower 2 and the waist of the distillation tower 3. The first liquid phase pipeline 11 , the second liquid phase pipeline 12 , and the third liquid phase pipeline 13 all transport liquid by means of pumping.

[0049] When the sodium methoxide production device produces sodium methoxide, methanol and sodium hydroxide raw materials are put into the alkali dissolving tank 1 to dissolve into methanol alkali solution, and the methanol alkali solution is discharged into the first buffer tank 4 through the first liquid phase pipeline 11, and then discharged into the second buffer tank 6 through the second liquid phase pipeline 12. When the methanol alkali solution passes through the second liquid phase pipeline 12, it is filtered and separated by the solid-liquid separation device 5, so that the impurities in the methanol alkali solution are precipitated and removed; the methanol alkali solution in the second buffer tank 6 is discharged into the reaction tower 2 through the third liquid phase pipeline 13, and the methanol raw material is distilled into methanol gas at the top of the distillation tower 3, and is introduced into the bottom of the reaction tower 2 through the first gas phase pipeline 21. The methanol gas reacts with the methanol alkali solution to generate sodium methoxide, and the mixed solution of sodium methoxide and methanol is discharged from the discharge pipe 14 at the bottom of the reaction tower 2. The methanol gas remaining after the reaction in the reaction tower 2 contains water, and the remaining methanol gas in the reaction tower 2 is introduced into the distillation tower 3 through the second gas phase pipeline 22 to participate in distillation again.

[0050] Reference Figure 1 、 Figure 2 and Figure 3 A connecting pipe 15 is connected between the waist of the first buffer tank 4 and the top of the second buffer tank 6. Connecting pipe 15 is equipped with an on / off control valve 151, which is a three-way valve, specifically a three-way ball valve with a T-shaped port. A bypass pipe 16 is connected to the bypass port of the three-way valve. The end of bypass pipe 16, away from the three-way valve, is connected to the top of the first buffer tank 4. Bypass pipe 16 is used to connect the end of connecting pipe 15 away from the first buffer tank 4. The three-way valve is used to control the opening and closing of connecting pipe 15 and the connection between bypass pipe 16 and connecting pipe 15. When bypass pipe 16 is connected to connecting pipe 15, connecting pipe 15 is closed. When the three-way valve closes the passage between bypass pipe 16 and connecting pipe 15, connecting pipe 15 is connected.

[0051] Reference Figure 1 and Figure 2 When the methanol-alkali solution is transmitted between the first buffer tank 4 and the second buffer tank 6 through the second liquid phase pipeline 12, the three-way valve is switched to a state where the bypass pipe 16 is connected to the connecting pipe 15, so that the top of the first buffer tank 4 is connected to the top of the second buffer tank 6. At this time, the air pressure in the first buffer tank 4 and the second buffer tank 6 is generally balanced, which is not easy to affect the pump flow of the methanol-alkali solution and the solid-liquid separation work of the solid-liquid separation equipment 5.

[0052] Reference Figure 1 and Figure 3When the solid-liquid separation equipment 5 needs to be overhauled or maintained, the solid-liquid separation equipment 5 suspends operation. After the first buffer tank 4 receives the methanol alkali solution discharged from the alkali dissolving tank 1, it separates the impurities in the methanol alkali by precipitation separation. During this process, the liquid level of the methanol alkali solution in the first buffer tank 4 is maintained at a position slightly lower than the upper end of the bypass pipe 16. When the methanol alkali solution completes precipitation separation, the three-way valve is switched to put the connecting pipe 15 in a passage state, so that the methanol alkali solution in the first buffer tank 4 flows to the second buffer tank 6 through the connecting pipe 15 to ensure the transportation demand of the methanol alkali solution of the solid-liquid separation equipment 5 during the overhaul or maintenance.

[0053] Reference Figure 4 and Figure 5 The first liquid phase pipeline 11 is connected to the center position of the bottom of the first buffer tank 4. A baffle 7 is provided on the inner side of the first buffer tank 4. The baffle 7 blocks the feed port of the first liquid phase pipeline 11 from top to bottom. The upper surface of the baffle 7 is a convex spherical surface. In other embodiments, it can also be set as a convex conical surface. The edge profile of the baffle 7 is square, that is, the projection of the baffle 7 on the horizontal plane is square. The corners of the baffle 7 respectively abut the bottom of the first buffer tank 4. The side edges between each two adjacent corners of the baffle 7 are defined as cut edges. A gap for liquid to pass through is formed between the cut edges of the baffle 7 and the inner circumference of the first buffer tank 4. A plurality of guide vanes 71 are provided on the upper surface of the baffle 7. The guide vanes 71 are arranged in an array around the central circumference of the baffle 7. The guide vanes 71 are used to form a swirl of liquid on the surface of the baffle 7.

[0054] The precipitate of the methanol-alkali solution in the first cache tank 4 slides along the upper surface of the baffle 7 to the bottom of the first cache tank 4; when the methanol-alkali solution in the first cache tank 4 is transferred to the second cache tank 6 through the second liquid phase pipeline 12, the methanol-alkali solution flowing from top to bottom is blocked and guided by the baffle 7, and flows along the inner circumference of the first cache tank 4, so that the liquid flow of the methanol-alkali solution can bring the precipitate into the second liquid phase pipeline 12 as much as possible; in addition, when the methanol-alkali solution flows along the upper surface of the baffle 7, it is guided by the guide vanes 71 to form a vortex, which can make it easier for the liquid flow of the methanol-alkali solution to carry the precipitate.

[0055] Reference Figure 1 A pressure regulating pipe 23 is connected between the top of the distillation tower 3 and the second buffer tank 6 and the top of the distillation tower 3. The pressure regulating pipe 23 is provided with a pressure differential regulating valve 231, which is a two-way regulating valve.

[0056] The pressure differential regulating valve 231 can keep the pressure difference between the top of the distillation tower 3 and the second buffer tank 6 relatively constant. When the methanol alkali solution in the second buffer tank 6 is discharged into the reaction tower 2, the overall pressure of the first buffer tank 4 and the second buffer tank 6 in the connected state decreases. At this time, the pressure differential regulating valve 231 can discharge part of the methanol gas at the top of the distillation tower 3 into the second buffer tank 6 to replenish the gas in the second buffer tank and reduce the outside air from entering the first buffer tank 4 and the second buffer tank 6 through the alkali dissolving tank 1.

[0057] Reference Figure 1 The air pressure regulating pipe 23 is provided with a liquid storage elbow 232, which is used to store methanol alkaline solution. The function of the liquid storage elbow 232 is similar to the water storage elbow in the drainage pipeline facility. The liquid storage elbow 232 is close to the second buffer tank 6 relative to the air pressure regulating pipe 23, and a relatively closed pipe section area is formed between the liquid storage elbow 232 and the pressure differential regulating valve 231. The air pressure regulating pipe 23 is provided with an air pressure sensor 233, which is located between the liquid storage elbow 232 and the pressure differential regulating valve 231. The air pressure between the liquid storage elbow 232 and the pressure differential regulating valve 231 can be obtained through the air pressure sensor 233. When the pressure differential regulating valve 231 fails, causing the methanol gas at the top of the distillation tower 3 to be abnormally discharged to the second buffer tank 6, the area where the air pressure sensor 233 is located will first have an air pressure change. Therefore, the failure of the pressure differential regulating valve 231 can be timely obtained through the air pressure sensor 233.

[0058] Reference Figure 1 The air pressure regulating tube 23 is connected to a flushing tube 17. The end of the flushing tube 17 away from the air pressure regulating tube 23 is connected to the methanol feed tube 18. The end of the flushing tube 17 connected to the air pressure regulating tube 23 is located between the liquid storage elbow 232 and the pressure differential regulating valve 231, and is higher than the liquid storage elbow 232. The flushing tube 17 is provided with a first locking valve 171. By opening the first locking valve 171, methanol in the methanol feed tube 18 can be introduced into the air pressure regulating tube 23, thereby replacing the methanol stored in the liquid storage elbow 232, thereby reducing the risk of methanol being retained and deteriorating over a long period of time.

[0059] In the sodium methoxide production device of the embodiment of the present application, the methanol-alkali solution between the first buffer tank 4 and the second buffer tank 6 can be transported through the solid-liquid separation device 5 or through the connecting pipe 15. The second liquid phase pipeline 12 equipped with the solid-liquid separation device 5 serves as the main transport path between the first buffer tank 4 and the second buffer tank 6, while the connecting pipe 15 serves as an auxiliary transport path between the first buffer tank 4 and the second buffer tank 6 to ensure the methanol-alkali transport demand of the solid-liquid separation device 5 during the overhaul or maintenance. Compared with the method of adding the solid-liquid separation device 5, the method of combining the first buffer tank 4 with the connecting pipe 15 can meet the temporary transport demand of the methanol-alkali solution with a simpler structure, which is conducive to reducing the cost of the equipment.

[0060] This embodiment also discloses a production method using the above-mentioned sodium methoxide production device, comprising the following steps:

[0061] Step 1: Add methanol and sodium hydroxide into a dissolving tank in proportion, and stir and dissolve the sodium hydroxide into a methanol alkaline solution;

[0062] Step 2: Discharge the methanol alkaline solution in the alkali dissolving tank 1 into the first buffer tank 4;

[0063] Step 3: Start the solid-liquid separation device 5 to separate the methanol liquid in the first buffer tank 4 into solid and liquid, and then discharge it into the second buffer tank 6;

[0064] Step 4: Repeat steps 1-2 to replenish the first buffer tank 4 with methanol alkaline solution.

[0065] By storing sufficient amounts of methanol-alkali solution in the first cache tank 4 and the second cache tank 6 respectively, when the methanol-alkali in the second cache tank 6 is consumed, the first cache tank 4 can replenish the methanol-alkali in the second cache tank 6 in time; in addition, during the consumption of the methanol-alkali solution in the second cache tank 6, the methanol-alkali solution in the first cache tank 4 has a certain precipitation time.

[0066] Example 2

[0067] Reference Figure 6 and Figure 7 The difference between this embodiment and embodiment 1 is that the third liquid phase pipeline 13 in this embodiment is provided with an ejector 242, and an intake pipe 24 is connected between the ejector 242 and the top of the second buffer tank 6. The intake pipe 24 is connected to the intake chamber of the ejector 242, and the intake pipe 24 is provided with a second locking valve 241.

[0068] When the first cache tank 4 and the second cache tank 6 are connected, when the alkali dissolving tank 1 discharges the methanol alkaline solution into the first cache tank 4, the overall air pressure of the first cache tank 4 and the second cache tank 6 increases. At this time, opening the second locking valve 241 can allow the ejector 242 to absorb the gas in the second cache tank 6 to reduce the overall air pressure of the first cache tank 4 and the second cache tank 6.

[0069] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A sodium methoxide production device, characterized in that: It includes an alkali dissolving tank, a reaction tower and a distillation tower, a first buffer tank, a solid-liquid separation device and a second buffer tank are provided between the alkali dissolving tank and the reaction tower, a first liquid phase pipeline is connected between the bottom of the alkali dissolving tank and the top of the first buffer tank, a second liquid phase pipeline is connected between the first buffer tank and the second buffer tank, the solid-liquid separation device is installed on the second liquid phase pipeline, a third liquid phase pipeline is connected between the second buffer tank and the top of the reaction tower, and a discharge pipe is provided at the bottom of the reaction tower; a methanol feed pipe is connected to the top of the distillation tower, a first gas phase pipeline is connected between the top of the distillation tower and the bottom of the reaction tower, and a second gas phase pipeline is connected between the top of the reaction tower and the waist of the distillation tower; a connecting pipe is connected between the waist of the first buffer tank and the top of the second buffer tank, and the connecting pipe is provided with a switch control valve, and the switch control valve is used to control the on-off of the connecting pipe; The switch control valve is a three-way valve, the bypass port of the three-way valve is connected to a bypass pipe, the end of the bypass pipe away from the three-way valve is connected to the top of the first cache tank, and the bypass pipe is used to communicate with the end of the connecting pipe away from the first cache tank. When the bypass pipe is connected to the connecting pipe, the connecting pipe is in a closed state. When the three-way valve closes the passage between the bypass pipe and the connecting pipe, the connecting pipe is in a connected state. An air pressure regulating pipe is connected between the top of the distillation tower and the second buffer tank and the top of the distillation tower, and the air pressure regulating pipe is provided with a pressure differential regulating valve; The air pressure regulating pipe is provided with a liquid storage elbow, the liquid storage elbow is used to store methanol alkaline solution, the liquid storage elbow is close to the second buffer tank relative to the pressure differential regulating valve, and the air pressure regulating pipe is provided with an air pressure sensor, and the air pressure sensor is located between the liquid storage elbow and the pressure differential regulating valve; The air pressure regulating pipe is plugged with a flushing pipe, one end of the flushing pipe away from the air pressure regulating pipe is connected to the methanol feed pipe, the position where the air pressure regulating pipe is connected to the flushing pipe is higher than the liquid storage elbow, and the flushing pipe is provided with a first locking valve; The third liquid phase pipeline is provided with an ejector, and an intake pipe is connected between the ejector and the top of the second cache tank. The intake pipe is connected to the intake chamber of the ejector. The ejector can absorb the gas in the second cache tank. The intake pipe is provided with a second locking valve.

2. The sodium methoxide production device according to claim 1, wherein: The first liquid phase pipeline is connected to the bottom of the first cache tank. A baffle is provided on the inside of the first cache tank. The upper surface of the baffle is an outwardly convex curved surface. A gap is left between the edge of the baffle and the inner circumferential surface of the first cache tank for liquid to pass through. A height margin is left between the baffle and the bottom of the first cache tank. The baffle blocks the feed port of the first liquid phase pipeline from top to bottom.

3. The sodium methoxide production device according to claim 2, wherein: A plurality of guide vanes are provided on the upper surface of the baffle, and the guide vanes are arranged in an array around the central circumference of the baffle. The guide vanes are used to form a swirl flow of the liquid on the surface of the baffle.

4. The sodium methoxide production device according to claim 2, wherein: The edge profile of the baffle is square, each corner of the baffle abuts the bottom of the first cache tank, and a gap is formed between the edge between each two adjacent corners of the baffle and the inner circumference of the first cache tank.

5. The production method of the sodium methoxide production device according to any one of claims 1 to 4, characterized in that: The process includes the following steps: Step 1: Add methanol and sodium hydroxide into a dissolving tank in proportion, and stir and dissolve the sodium hydroxide into a methanol alkaline solution; Step 2: Discharge the methanol alkaline solution in the alkali dissolving tank into the first buffer tank; Step 3: Start the solid-liquid separation equipment to separate the methanol liquid in the first buffer tank into solid and liquid and then discharge it into the second buffer tank; Step 4: Repeat steps 1-2 to add methanol alkaline solution to the first buffer tank.

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