Reaction device for synthesizing tetramethyl carbonate monomethyl ester

Abstract

The utility model belongs to a reaction device for synthesizing tetramethyl carbonate monomethyl ester. Comprising a trimethylamine methanol solution pipeline and an electronic-grade dimethyl carbonate pipeline, the trimethylamine methanol solution pipeline and the electronic-grade dimethyl carbonate pipeline are respectively connected with a first tee joint, a third end of the first tee joint passes through a mixed heating unit, and the mixed heating unit is connected with an inlet of a gas-liquid separator; a bottom liquid phase outlet of the gas-liquid separator is connected with the mixed heating unit through a circulating pump, and a product extraction port of the gas-liquid separator is connected with a reaction liquid discharge pipeline; the reaction kettle has the advantages that materials can be fully mixed and heated, and the reaction kettle is matched with corresponding accessories to improve the synthesis reaction rate and save raw materials on the basis of miniaturization of equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of tetramethyl carbonate production, in particular to a reaction device for synthesizing tetramethyl carbonate. Background Art

[0002] Methyl tetramethyl carbonate is an intermediate in tetramethylammonium hydroxide, a developer used in electronics manufacturing. With the booming electronics industry, demand for and production of developer solutions are increasing, leading to increased production efficiency for intermediate products.

[0003] Tetramethyl carbonate is produced by the reaction of trimethylamine and dimethyl carbonate under high temperature and high pressure conditions. The reaction equation is as follows:

[0004] (CH3)3N+CH3OH→(CH3)4NOCOOCH3

[0005] The existing synthesis of methyl tetramethyl carbonate mainly adopts a series of tubular reactors, which has the disadvantages of large equipment footprint and insufficient material mixing (refer to patent publication number CN107417539A, which discloses a kettle reactor connected in series with a tubular reactor). In particular, when the materials cannot be fully mixed, the synthesis reaction is affected, resulting in a large amount of raw material waste. Utility Model Content

[0006] The purpose of the utility model is to solve the problems in the prior art and to propose a reaction device for synthesizing tetramethyl monomethyl carbonate.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A reaction device for synthesizing tetramethyl carbonate comprises a trimethylamine methanol solution pipeline and an electronic-grade dimethyl carbonate pipeline, wherein the trimethylamine methanol solution pipeline and the electronic-grade dimethyl carbonate pipeline are respectively connected to a first tee, a third end of the first tee passes through a mixing heating unit, and the mixing heating unit is connected to an inlet of a gas-liquid separator. A bottom liquid phase outlet of the gas-liquid separator is connected to the mixing heating unit via a circulation pump, and a product outlet of the gas-liquid separator is connected to a reaction liquid discharge pipeline.

[0009] The beneficial effects of the present invention are as follows: by setting up a mixing and heating unit, the materials can be fully mixed, and a synthetic reaction between the materials can be achieved in a heated environment; further, by setting up a circulation pump, the circulation of the materials and the adjustment of the material circulation speed can be achieved, thereby adjusting the material residence time on the basis of saving raw materials to achieve the characteristics of full reaction between the materials; further, the present invention is provided with a gas-liquid separator, which can not only achieve gas-liquid separation to avoid cavitation in the circulation pump, but also achieve buffering of the materials, laying the foundation for adjusting the material residence time in the subsequent process.

[0010] Preferably, the mixing heating unit includes a reactor, which includes a heat exchange cavity composed of a steam jacket outer shell and a steam jacket inner shell, the steam jacket outer shell is provided with at least a steam inlet pipe and a condensate outlet pipe, and a heat exchange coil is provided inside the heat exchange cavity, the heat exchange coil includes a heat exchange static mixing element at the front and a reaction pipe at the rear, and the outlet of the reaction pipe is connected to the inlet of the gas-liquid separator.

[0011] Preferably, the mixing and heating unit further comprises a static mixing element provided at the front of the reactor, the static mixing element is provided with a second tee, and the third end of the second tee is connected to the outlet of the circulation pump.

[0012] Preferably, the heat exchange coil is in a spiral ascending shape, the lower part of the spiral ascending heat exchange coil is a heat exchange static mixing element, and the upper part is a reaction pipe; the length of the heat exchange static mixing element is one third of the total length of the heat exchange coil.

[0013] Preferably, the static mixer and the heat exchange static mixer are an integrated structure, and both are SV type static mixers.

[0014] Preferably, a steam exhaust pipe is further provided on the outer shell of the steam jacket.

[0015] Preferably, the top of the gas-liquid separator is connected to the exhaust gas discharge pipe of the exhaust gas official website.

[0016] A reaction device for synthesizing tetramethyl carbonate is prepared according to the above scheme. In order to meet the extremely high (G5) requirement of electronic chemicals for product impurity content and accelerate the synthesis reaction rate, the utility model selects polar chemical methanol as a solvent to participate in the reaction system, so that the two raw materials are in the same liquid phase; based on the above invention ideas, the utility model designs a mixing heating unit, as well as a gas-liquid separator and a circulation pump matched therewith; by setting up the mixing heating unit, the raw materials can be fully mixed, and the uniformity of the liquid phase is improved, which lays the foundation for increasing the rate of the synthesis reaction. The gas-liquid separator can separate the gasified chemical products from the liquid phase under high temperature conditions, thereby protecting the circulation pump. The circulating pump provided in addition can control the residence time of the reaction liquid by adjusting the pump frequency to save raw materials and achieve the purpose of sufficient reaction between materials; the mixing heating unit described in the utility model can achieve full mixing and heating of the materials, and in combination with the corresponding auxiliary components, it can achieve the advantages of improving the synthesis reaction rate and saving raw materials on the basis of miniaturization of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of the utility model;

[0018] Figure 2 This is a schematic diagram of the top structure of the utility model;

[0019] Figure 3 This is a schematic diagram of the positional relationship between the heat exchange static mixing element and the static mixing element in the present utility model.

[0020] In the figure: 1. trimethylamine methanol solution pipeline; 2. electronic grade dimethyl carbonate pipeline; 3. first tee; 4. second tee; 5. gas-liquid separator; 6. circulation pump; 7. reaction liquid discharge pipeline; 8. steam jacket outer shell; 9. steam jacket inner shell; 10. heat exchange cavity; 11. steam inlet pipeline; 12. condensate outlet pipeline; 13. heat exchange coil; 14. heat exchange static mixer; 15. reaction pipeline; 16. static mixer; 17. steam discharge pipeline; 18. exhaust gas discharge pipeline. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] like Figure 1 - Figure 3As shown, a reaction device for synthesizing tetramethyl carbonate includes a trimethylamine methanol solution pipeline 1 and an electronic-grade dimethyl carbonate pipeline 2. The trimethylamine methanol solution pipeline 1 and the electronic-grade dimethyl carbonate pipeline 2 are respectively connected to a first tee 3. The third end of the first tee 3 passes through a mixing heating unit, and the mixing heating unit is connected to the inlet of a gas-liquid separator 5. The bottom liquid phase outlet of the gas-liquid separator 5 is connected to the mixing heating unit via a circulation pump 6. The product outlet of the gas-liquid separator 5 is connected to a reaction liquid discharge pipeline 7. The present invention abandons the traditional technical route and selects polar chemical methanol as a solvent to participate in the reaction system, so that the two raw materials are in the same liquid phase to achieve the purpose of increasing the raw material synthesis reaction speed. Based on this, the present invention is provided with a mixing and heating unit to achieve sufficient mixing between the raw materials, and at the same time heat the raw materials to meet the requirements of the synthesis reaction. Furthermore, the present invention is provided with a liquid raw material reflux part based on a gas-liquid separator 5 and a circulation pump 6, which can not only save raw materials, but also adjust the material residence time by the frequency of the pump to achieve the characteristics of sufficient reaction of the materials. The present invention can achieve the characteristics of miniaturization of the equipment and thus save the equipment floor space through the above-mentioned settings. In addition, because trimethylamine and methanol are easy to gasify under high temperature conditions, cavitation will be caused in the circulation pump 6 during the circulation process. In order to increase the service life of the circulation pump 6, the gas-liquid separator 5 is added to separate the gas and liquid phases, so that the pure liquid phase enters the circulation system to meet the working conditions of the circulation pump 6.

[0023] Furthermore, the mixing and heating unit includes a reactor, which includes a heat exchange cavity 10 consisting of a steam jacket outer shell 8 and a steam jacket inner shell 9. The steam jacket outer shell 8 is provided with at least a steam inlet pipe 11 and a condensate outlet pipe 12. A heat exchange coil 13 is provided inside the heat exchange cavity 10. The heat exchange coil 13 includes a heat exchange static mixer 14 at the front and a reaction pipe 15 at the rear. The outlet of the reaction pipe 15 is connected to the inlet of the gas-liquid separator 5. The reactor described in the present invention contains a heat exchange static mixer 14, which can efficiently mix the raw materials and increase the uniformity of the liquid, thereby increasing the reaction rate; the reaction pipe 15 can be used for the synthesis reaction between the raw materials, and the gas-liquid separator 5 connected to the reaction pipe 15 can separate the vaporized chemical products from the liquid phase under high temperature conditions, thereby protecting the circulation pump; the tubular reactor is connected to the circulation pump, and the residence time of the reaction liquid can be controlled by adjusting the pump frequency.

[0024] Furthermore, the mixing and heating unit further comprises a static mixing element 16 provided at the front of the reactor. A second tee 4 is provided on the static mixing element 16 , and a third end of the second tee is connected to the outlet of the circulation pump 6 .

[0025] Furthermore, the heat exchange coil 13 is spirally ascending, with a heat exchange static mixer 14 at its lower portion and a reaction pipe 15 at its upper portion. The length of the heat exchange static mixer 14 is one-third of the total length of the heat exchange coil 13. The heat exchange static mixer 14 described in the present invention is located in the front third of the heat exchange coil 13. Preferably, the heat exchange static mixer 14 is an SV-type static mixer, which allows for rapid and uniform mixing of the liquid dimethyl carbonate and trimethylamine methanol solution transported through the pipeline, accelerating effective collisions between molecules and increasing the reaction rate.

[0026] Furthermore, the static mixer 16 and the heat exchange static mixer 14 are an integrated structure, and both are SV type static mixers. The above arrangement can achieve the characteristics of improved air tightness and easy processing.

[0027] Furthermore, a steam exhaust pipe 17 is provided on the steam jacket shell 8. The steam exhaust pipe 17 can be used to adjust the temperature in the reactor and recover the steam in the heat exchange cavity 10. The steam exhaust pipe 17 is preferably connected to the steam network.

[0028] Furthermore, the top of the gas-liquid separator 5 is connected to the exhaust gas discharge pipe 18 of the exhaust gas official website.

[0029] The working principle of the present invention is as follows: SO5 steam is sent into the heat exchange cavity 10 through the steam inlet pipe 11 in advance to preheat the heat exchange coil 13, and the condensate in the heat exchange cavity 10 is discharged through the condensate outlet pipe 12; the temperature of the heat exchange coil 13 is raised to about 100°C, and the steam discharge pipe 17 is adjusted to recycle the excess steam into the steam pipe network for recycling, so as to achieve the reactor maintaining the aforementioned temperature; at the same time, the electronic grade trimethylamine methanol solution with a mass concentration of 30% is made to enter the first tee 3 through the trimethylamine methanol solution pipe 1, and the electronic grade dimethyl carbonate is made to enter the first tee 3 through the electronic grade dimethyl carbonate pipe 2. The preferred feed ratio of the above trimethylamine and dimethyl carbonate is 1:1. The two raw materials are first fully mixed in the static mixer 16, and then enter the heat exchange static mixer 14 after mixing. According to the spiral rising structure, the mixture is stirred at room temperature. The raw materials of the structural form are continuously mixed and the reaction is accelerated, so that the temperature of the reaction liquid is continuously increased, resulting in the decomposition of dimethyl carbonate or the gasification of methanol; as the liquid flows, the mixed liquid enters the gas-liquid separator 5 through the outlet of the reaction pipe 15, and is separated into gas and liquid in the gas-liquid separator 5, and the gas in the reaction liquid is discharged to the waste gas network through the waste gas exhaust pipe 18, and the liquid-phase reaction liquid enters the static mixer 16 through the circulation pump 6, so that the dimethyl carbonate that has not reacted completely is re-mixed and reacted; in order to meet the residence time and the reaction is completed, the reaction liquid enters the reaction liquid exhaust pipe 7 through the product extraction port of the gas-liquid separator 5 to realize external extraction. The SV type static mixer described in the utility model can make the materials mix evenly, thereby improving the reaction efficiency; by circulating backflow and fully mixing the materials, the utilization rate of raw materials can be effectively increased and the pressure of later separation can be reduced. The present invention is provided with a static mixer 16 and a heat exchange static mixer 14, which can achieve sufficient mixing of materials. It can mix evenly at two different temperatures to ensure that the two raw materials are in the same liquid phase. Further, the above design can reduce the construction and cost investment of raw material premixing equipment, and realize the miniaturization of equipment; the present invention is designed with a closed pipeline formed by circulation reflux, and in conjunction with the circulation pump 6, it can increase the reflux residence time and mixing degree of the reaction liquid, thereby achieving the characteristics of improving reaction efficiency, increasing raw material conversion rate, and reducing the later raw material processing cost, and through the combination of the gas-liquid separator 5 and the circulation pump 6, by separating the gas, the purpose of reducing the loss of the circulation pump and extending the service life is achieved.

[0030] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A reaction device for synthesizing tetramethyl carbonate, comprising a trimethylamine methanol solution pipeline (1) and an electronic grade dimethyl carbonate pipeline (2), characterized in that: The trimethylamine methanol solution pipeline (1) and the electronic grade dimethyl carbonate pipeline (2) are respectively connected to the first tee (3); the third end of the first tee (3) passes through a mixing heating unit, and the mixing heating unit is connected to the inlet of the gas-liquid separator (5); the bottom liquid phase outlet of the gas-liquid separator (5) is connected to the mixing heating unit through a circulation pump (6); and the product extraction outlet of the gas-liquid separator (5) is connected to the reaction liquid discharge pipeline (7).

2. The reaction device for synthesizing tetramethyl carbonate according to claim 1, wherein The mixing and heating unit comprises a reactor, which comprises a heat exchange cavity (10) consisting of a steam jacket outer shell (8) and a steam jacket inner shell (9), wherein the steam jacket outer shell (8) is provided with at least a steam inlet pipe (11) and a condensate outlet pipe (12), and a heat exchange coil (13) is provided inside the heat exchange cavity (10), wherein the heat exchange coil (13) comprises a heat exchange static mixing element (14) at the front and a reaction pipe (15) at the rear, and the outlet of the reaction pipe (15) is connected to the inlet of the gas-liquid separator (5).

3. The reaction device for synthesizing tetramethyl carbonate according to claim 2, wherein The mixing and heating unit further comprises a static mixing element (16) arranged at the front of the reactor, a second tee (4) is provided on the static mixing element (16), and a third end of the second tee is connected to the outlet of the circulation pump (6).

4. The reaction device for synthesizing tetramethyl carbonate according to claim 2, wherein The heat exchange coil (13) is in a spiral ascending shape, the lower part of the spiral ascending heat exchange coil (13) is a heat exchange static mixing element (14), and the upper part is a reaction pipe (15); the length of the heat exchange static mixing element (14) is one third of the total length of the heat exchange coil (13).

5. The reaction device for synthesizing tetramethyl carbonate according to claim 3, wherein: The static mixer (16) and the heat exchange static mixer (14) are an integrated structure, and both are SV type static mixers.

6. A reaction device for synthesizing tetramethyl carbonate according to claim 2, characterized in that: The steam jacket shell (8) is also provided with a steam exhaust pipe (17).

7. A reaction device for synthesizing tetramethyl carbonate according to claim 1, characterized in that: The top of the gas-liquid separator (5) is connected to an exhaust gas discharge pipe (18) connected to the exhaust gas official website.

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