A kind of ammonia removal reaction system for preparing cyclic carbonate by urea process

Abstract

The present invention relates to the field of cyclic carbonate preparation devices, and specifically discloses an ammonia removal reaction system for preparing cyclic carbonate by urea method, which solves the technical problem that ammonia inside the material is difficult to remove during the current urea method for preparing cyclic carbonate. It includes: a reactor, provided with a first feed inlet, a first discharge port and a gas phase pipe, the reactor body height dimension of the reactor is smaller than its diameter dimension; a main stirring assembly, including a first stirring motor, a stirring spindle and a stirring blade, wherein the first stirring motor is connected to the stirring blade through the stirring spindle, and the stirring spindle is perpendicular to the axis of the reactor; a nitrogen blowing pipe, which is provided with a plurality of nitrogen blowing pipes, which are arranged at intervals along the circumference of the reactor. On the one hand, the flattening of the reactor body increases the surface area of ​​the liquid surface to promote the escape of ammonia; on the other hand, the material is thrown upward during the stirring process, which significantly improves the ammonia removal effect.

Description

Technical Field

[0001] The invention relates to the technical field of cyclic carbonate preparation devices, and in particular to an ammonia removal reaction system for preparing cyclic carbonate using a urea process. Background Art

[0002] Cyclic carbonates have attracted much attention due to their wide applications in synthetic chemistry fields such as solvents, resins, and drugs. These compounds have excellent solubility, low toxicity, and biodegradability, and therefore have important application value in the industrial and pharmaceutical fields. The urea process is a commonly used method for preparing cyclic carbonates, which generates cyclic carbonates through the reaction of urea with carbon dioxide. Specifically, urea first decomposes at high temperatures to produce ammonia and isocyanate, and then the isocyanate reacts with carbon dioxide to generate cyclic carbonates. However, the ammonia removal step in the process is one of the key factors affecting product purity and yield. The presence of ammonia not only interferes with the subsequent reaction, but also leads to the generation of by-products, thereby reducing the purity and yield of the target product.

[0003] The prior art generally focuses on how to remove ammonia in the reactor, but it is always difficult to completely remove the ammonia remaining in the material. When a common vertical reactor is used for reaction, the material accumulates in the reactor, and some ammonia still remains in the material, which is difficult to completely remove. This situation may not only affect the quality and yield of the final product, but also generate other by-products, increasing the operating cost. Summary of the invention

[0004] The purpose of the present invention is to provide an ammonia removal reaction system for preparing cyclic carbonates by the urea method, so as to solve the technical problem that ammonia inside the material is difficult to remove during the current urea method for preparing cyclic carbonates.

[0005] The present invention provides an ammonia removal reaction system for preparing cyclic carbonate by a urea process, comprising: a reactor provided with a first feed inlet, a first discharge outlet and a gas phase pipe, wherein the reactor body height dimension is smaller than the diameter dimension; a main stirring assembly, comprising a first stirring motor, a stirring main shaft and a stirring blade, wherein the first stirring motor is connected to the stirring blade through the stirring main shaft, and the stirring main shaft is perpendicular to the axial direction of the reactor; a plurality of nitrogen blowing pipes are provided, which are arranged at intervals along the circumference of the reactor.

[0006] According to one embodiment of the present invention, the axis-to-diameter ratio of the reactor ranges from 2:1 to 20:1. 。

[0007] According to one embodiment of the present invention, the stirring blade is a cage-type structure and is connected to the stirring main shaft.

[0008] According to one embodiment of the present invention, the stirring blade includes a longitudinal stirring rod arranged parallel to the stirring main shaft and a transverse stirring rod arranged radially along the stirring shaft. A plurality of transverse stirring rods are arranged at intervals along the extension direction of the longitudinal stirring rod, and the transverse stirring rods are connected to the stirring main shaft.

[0009] According to one embodiment of the present invention, a secondary stirring assembly is further included, wherein the secondary stirring assembly includes a second stirring motor, a second stirring shaft and a second stirring paddle connected to each other, and the second stirring paddle is located inside the reactor.

[0010] According to one embodiment of the present invention, the auxiliary stirring components are provided in multiple groups, which are symmetrically arranged on both sides of the stirring blade with the vertical center line of the stirring main shaft as the axis.

[0011] According to one embodiment of the present invention, the reactor is provided with a liquid level gauge interface, and a valve is provided on the liquid level gauge interface.

[0012] According to one embodiment of the present invention, the reactor is provided with a heating jacket and a heating coil.

[0013] According to one embodiment of the present invention, the gas phase pipe is connected to a vacuum system via a condenser.

[0014] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0015] (1) The height dimension of the reactor body designed in the present invention is smaller than the diameter dimension, so that the reactor body is flattened, the surface area of ​​the liquid surface is increased, and it is beneficial for the escape of ammonia.

[0016] (2) The present invention designs a cage-type stirring blade. Since the stirring shaft is perpendicular to the axial direction of the reactor, that is, part of the stirring blade is located below the liquid level in the reactor and part is located above the liquid level, the stirring shaft can throw the material upward when it rotates, effectively promoting the escape of ammonia in the material, while ensuring the uniform mixing of the material, thereby significantly improving the ammonia removal effect.

[0017] (3) The present invention designs a liquid level meter interface, a heating jacket and a heating coil to facilitate real-time monitoring and adjustment of the reaction temperature, thereby ensuring the stability and controllability of the reaction conditions.

[0018] (4) The present invention is provided with a vacuum system, which is connected to the gas phase pipe through a condenser, and can effectively recover the gas generated during the reaction process, further improving the overall efficiency and economy of the system.

[0019] (5) The present invention is provided with a secondary stirring assembly, which further ensures the escape of ammonia and the uniform mixing of materials, thereby enhancing the overall performance of the system.

[0020] (6) The present invention is provided with a nitrogen gas blowing pipe, which can increase the escape rate of ammonia, reduce the occurrence of side reactions, and further improve the purity and yield of the product.

[0021] (7) The present invention has reasonable design, simple structure, good practicality and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a schematic structural diagram of an ammonia removal reaction system for preparing cyclic carbonates using the urea method provided in Example 1 of the present invention.

[0024] Figure 2 A schematic structural diagram of a main stirring assembly of an ammonia removal reaction system for preparing cyclic carbonate by a urea process provided in Example 2 of the present invention.

[0025] Reference numerals:

[0026] 100, reactor; 110, first feed inlet; 120, first discharge outlet; 130, gas phase pipe;

[0027] 200, nitrogen blowing pipe;

[0028] 300, condenser;

[0029] M1, first stirring motor; 410, stirring main shaft; 421, vertical stirring rod; 422, horizontal stirring rod;

[0030] M2, second stirring motor; 430, stirring paddle;

[0031] 500, liquid level meter interface;

[0032] 600, heating jacket;

[0033] 700. Heating coil. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Example 1

[0036] Embodiment 1 of the present invention provides an ammonia removal reaction system for preparing cyclic carbonate by urea method, so as to promote the overflow of ammonia inside the material.

[0037] See also Figure 1 The ammonia removal reaction system for preparing cyclic carbonate by urea method provided in an embodiment of the present invention comprises: a reactor 100, which is provided with a first feed inlet 110, a first discharge outlet 120 and a gas phase pipe 130, wherein the height dimension of the reactor body of the reactor 100 is smaller than its diameter dimension, thereby realizing the flattening of the reactor body, increasing the surface area of ​​the liquid surface, and facilitating the escape of ammonia; a main stirring assembly, comprising a first stirring motor M1, a stirring main shaft 410 and a stirring blade, wherein the first stirring motor M1 is connected to the stirring blade through the stirring main shaft 410, and the stirring main shaft 410 is perpendicular to the reactor 10 0 axial direction, when the stirring main shaft 410 rotates, the material can be thrown upward, which effectively promotes the escape of ammonia in the material, and at the same time ensures the uniform mixing of the material, which significantly improves the ammonia removal effect; there are multiple nitrogen blowing pipes 200, which are arranged at intervals along the circumference of the reactor 100, which can increase the escape rate of ammonia, reduce the occurrence of side reactions, and further improve the purity and yield of the product. The blowing of nitrogen can also dilute the concentration of ammonia, reduce the local concentration of ammonia in the reactor 100, and reduce the solubility of ammonia in the material, thereby more effectively removing ammonia.

[0038] In this embodiment, the axis-to-diameter ratio of the reactor 100 ranges from 2:1 to 20:1, which can maximize the liquid surface area while ensuring the volume of the reactor 100, thereby further improving the escape efficiency of ammonia.

[0039] In this embodiment, the stirring blade is a cage-like structure and is connected to the stirring main shaft 410 .

[0040] In this embodiment, the stirring blade includes a longitudinal stirring rod 421 arranged parallel to the stirring main shaft 410 and a transverse stirring rod 422 arranged radially along the stirring shaft. Along the extension direction of the longitudinal stirring rod 421, multiple transverse stirring rods 422 are arranged at intervals, and the transverse stirring rods 422 are connected to the stirring main shaft 410.

[0041] In this embodiment, an auxiliary stirring assembly is also included, which includes a second stirring motor M2, a second stirring shaft and a second stirring paddle 430 connected to each other. The second stirring paddle 430 is located inside the reactor 100, which further ensures the escape of ammonia and the uniform mixing of materials, thereby enhancing the overall performance of the system.

[0042] In this embodiment, multiple groups of auxiliary stirring components are provided, which are symmetrically arranged on both sides of the stirring blades with the vertical center line of the stirring main shaft 410 as the axis. The auxiliary stirring components work together with the main stirring components to form a more complex flow field, improve the mixing effect of the materials, and ensure the uniformity and efficiency of the reaction.

[0043] In this embodiment, the reactor 100 is provided with a liquid level meter interface 500, and a valve is provided on the liquid level meter interface 500 to facilitate real-time monitoring of liquid level changes during the reaction process.

[0044] In this embodiment, the reactor 100 is provided with a heating jacket 600 and a heating coil 700, which are convenient for adjusting the reaction temperature and ensuring the stability and controllability of the reaction conditions. The heating jacket 600 can provide uniform heat to ensure uniform temperature distribution in the reactor 100 and avoid local overheating or overcooling. The heating coil 700 can quickly reduce the temperature in the reactor 100 when necessary to prevent overheating of the reaction and ensure the safety and controllability of the reaction.

[0045] In this embodiment, the gas phase pipe 130 is connected to the vacuum system via the condenser 300, which can effectively recover the gas generated during the reaction process, further improving the overall efficiency and economy of the system.

[0046] In this embodiment, the liquid level in the reactor 100 is 1 mm to 20 mm;

[0047] The following is a detailed description of the use of the ammonia removal reaction system for preparing cyclic carbonate by the urea process of the present invention:

[0048] During use, the materials are uniformly mixed and ammonia overflows through the stirring action of the main stirring component and the auxiliary stirring component, and the overflowed ammonia is discharged from the gas phase pipe 130 to ensure the safety of the reaction.

[0049] Example 2

[0050] Embodiment 2 of the present invention provides an ammonia removal reaction system for preparing cyclic carbonate by urea method, so as to promote the overflow of ammonia inside the material.

[0051] See also Figure 2 The ammonia removal reaction system for preparing cyclic carbonate by the urea method provided in the embodiment of the present invention is different from that in Example 1 only in that, in the present embodiment, the horizontal stirring rod 422 and the vertical stirring rod 421 are both porous structures, and the inner holes are interconnected, and the inner holes are connected to the external environment. When stirring is performed, part of the material is retained in the inner holes and then thrown out by centrifugal force, which further promotes the discharge of ammonia.

[0052] The embodiments of the present invention have at least the following advantages:

[0053] (1) The height dimension of the reactor body designed in the present invention is smaller than the diameter dimension, so that the reactor body is flattened, the surface area of ​​the liquid surface is increased, and it is beneficial for the escape of ammonia.

[0054] (2) The present invention designs a cage-type stirring blade. Since the stirring shaft is perpendicular to the axial direction of the reactor, that is, part of the stirring blade is located below the liquid level in the reactor and part is located above the liquid level, the stirring shaft can throw the material upward when it rotates, effectively promoting the escape of ammonia in the material, while ensuring the uniform mixing of the material, thereby significantly improving the ammonia removal effect.

[0055] (3) The present invention designs a liquid level meter interface, a heating jacket and a heating coil to facilitate real-time monitoring and adjustment of the reaction temperature, thereby ensuring the stability and controllability of the reaction conditions.

[0056] (4) The present invention is provided with a vacuum system, which is connected to the gas phase pipe through a condenser, and can effectively recover the gas generated during the reaction process, further improving the overall efficiency and economy of the system.

[0057] (5) The present invention is provided with a secondary stirring assembly, which further ensures the escape of ammonia and the uniform mixing of materials, thereby enhancing the overall performance of the system.

[0058] (6) The present invention is provided with a nitrogen gas blowing pipe, which can increase the escape rate of ammonia, reduce the occurrence of side reactions, and further improve the purity and yield of the product.

[0059] (7) The present invention has reasonable design, simple structure, good practicality and economic benefits.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A deammonification reaction system for preparing cyclic carbonate by urea process, characterized in that: include: A reactor is provided with a first feed port, a first discharge port and a gas phase pipe, wherein the height of the reactor is smaller than its diameter; A main stirring assembly, comprising a first stirring motor, a stirring main shaft and a stirring blade, wherein the first stirring motor is connected to the stirring blade via the stirring main shaft, and the stirring main shaft is perpendicular to the axial direction of the reactor; There are multiple nitrogen blowing pipes, which are arranged at intervals along the circumference of the reactor.

2. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to claim 1, characterized in that: The axis-to-diameter ratio of the reactor ranges from 2:1 to 20:

1.

3. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to claim 1, characterized in that: The stirring blade is in a cage-like structure and is connected to the stirring main shaft.

4. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to claim 3, characterized in that: The stirring blade includes a longitudinal stirring rod arranged parallel to the stirring main shaft and a transverse stirring rod arranged radially along the stirring shaft. A plurality of transverse stirring rods are arranged at intervals along the extending direction of the longitudinal stirring rod, and the transverse stirring rods are connected to the stirring main shaft.

5. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to any one of claims 1 to 4, characterized in that: It also includes an auxiliary stirring component, which includes a second stirring motor, a second stirring shaft and a second stirring paddle connected to each other, and the second stirring paddle is located inside the reactor.

6. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to claim 5, characterized in that: The auxiliary stirring components are provided in multiple groups, and are symmetrically arranged on both sides of the stirring blade with the vertical center line of the stirring main shaft as the axis.

7. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to any one of claims 1 to 4, characterized in that: The reactor is provided with a liquid level gauge interface, and a valve is provided on the liquid level gauge interface.

8. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to any one of claims 1 to 4, characterized in that: The reactor is provided with a heating jacket and a heating coil.

9. The ammonia removal reaction system for preparing cyclic carbonate by urea process according to any one of claims 1 to 4, characterized in that: The gas phase pipe is connected to a vacuum system through a condenser.

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