Raw material premixing system for preparing cyclic carbonate by urea method

Abstract

The utility model relates to the technical field of preparation of cyclic carbonate by a urea method, and aims to solve the problem that in the prior art, when urea, polyol and a catalyst are heated and blended in a raw material mixer, side reaction is generated, so that the final reaction yield is influenced. The utility model provides a raw material premixing system for preparing cyclic carbonate by a urea method. The raw material premixing system comprises a urea premixing system, a catalyst premixing system, a first buffer tank, a second buffer tank and a reaction kettle, the urea premixing system is communicated with the buffer system; the urea premixing system is communicated with the first buffer tank; the catalyst premixing system is communicated with the second buffer tank; the first buffer tank and the second buffer tank are both communicated with the reaction kettle; according to the raw material premixing system for preparing the cyclic carbonate through the urea method, a respective premixing mode is adopted, so that side reactions in the raw material premixing stage are effectively reduced, and the final reaction yield is fully improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to urea method preparation cyclic carbonate technical field, specifically, relate to a kind of raw material premixing system of urea method preparation cyclic carbonate. BACKGROUND

[0002] When urea method preparation cyclic carbonate, reaction raw material includes urea, propylene glycol / glycol, solid catalyst, in raw material preparation stage, three usually mix in premixing tank, subsequently into reaction kettle and warm up reaction, such as the patent of CN104059047A, its disclosed urea synthesis cyclic carbonate continuous reaction process, specifically, it is formed after mixing material in raw material mixer by urea, polyhydric alcohol and catalyst, then, from raw material mixer kettle bottom discharge port, and by the heater that raw material mixer has, mixing material is heated, and under the condition of circulating production ratio, raw material mixed solution is formed;However, in order to promote dissolution, it needs to be warmed to about 80 DEG C in premixing process, under this condition, if catalyst exists, there will be more side reactions, thereby affecting final reaction yield.

[0003] Based on the above description, there is an urgent need for a raw material premixing system for urea method preparation of cyclic carbonate to reduce the generation of side reactions in the raw material blending stage. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a raw material premixing system for urea method preparation of cyclic carbonate, which aims to solve the technical problem of existing technology that side reactions occur when urea, polyhydric alcohol and catalyst are heated and blended in a raw material mixer, thereby affecting the final reaction yield.

[0005] The embodiments of the utility model are implemented by the following technical solutions:

[0006] A raw material premixing system for urea method preparation of cyclic carbonate, comprising a urea premixing system, a catalyst premixing system, a first buffer tank, a second buffer tank and a reaction kettle, the urea premixing system is in communication with the first buffer tank, the catalyst premixing system is in communication with the second buffer tank, and the first buffer tank and the second buffer tank are in communication with the reaction kettle.

[0007] Preferably, the urea premixing system comprises a plurality of premixing tanks, a plurality of urea feed pipes, a plurality of propylene glycol feed pipes and a plurality of discharge pipes, the urea feed pipes and the propylene glycol feed pipes are in communication with the premixing tanks, and the premixing tanks are in communication with the first buffer tank through the discharge pipes.

[0008] Preferably, the urea premixing system further comprises a converging manifold, the plurality of discharge pipes are in communication with the converging manifold, and the converging manifold is in communication with the first buffer tank.

[0009] As preferred, the discharge pipe is provided with a flow valve near one end of the converging manifold.

[0010] As preferred, a plurality of the premixing tanks are communicated with each other by a circulation system.

[0011] As preferred, the circulation system comprises a circulation pipe and a circulation pump; the circulation pipe is communicated between a pair of the premixing tanks; and the circulation pump is arranged in the circulation pipe.

[0012] As preferred, one end of the circulation pipe is communicated with a discharge pipe of one of the premixing tanks; and the other end of the circulation pipe is communicated with another one of the premixing tanks.

[0013] The technical scheme of the embodiment of the utility model has at least the following advantages and beneficial effects:

[0014] The raw material premixing system for preparing cyclic carbonate by urea method is used for premixing propylene glycol and urea, and the premixed material is buffered in the first buffer tank; the catalyst premixing system is used for premixing catalyst and propylene glycol, and the premixed material is buffered in the second buffer tank, and each material after premixing is sent into the reaction kettle in the proportion required by production by each feeding pump for reaction; compared with the traditional raw material blending mode, the utility model adopts the mode of separate premixing of material, namely separate dissolution of the reaction kettle, thereby effectively reducing the generation of side reaction in the raw material premixing stage and fully improving the yield of final reaction. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment, and it should be understood that the following drawings only show some embodiments of the utility model, and therefore should not be regarded as a limitation to the scope, and for the ordinary skilled person in the art, other related drawings can also be obtained from the drawings without creative labor.

[0016] Figure 1 It is a system schematic view of the utility model.

[0017] Figure legend: 1-urea premixing system, 11-premixing tank, 12-urea feeding pipe, 13-propylene glycol feeding pipe, 14-discharge pipe, 15-converging manifold, 2-catalyst premixing system, 3-first buffer tank, 4-second buffer tank, 5-reaction kettle. DETAILED DESCRIPTION

[0018] Embodiment 1

[0019] Please refer to Figure 1The utility model provides the following technical scheme: a raw material premixing system for preparing cyclic carbonate by urea method is suitable for the case that each raw material for preparing cyclic carbonate by urea method is premixed respectively.

[0020] Specifically, as shown in the figure, Figure 1 a raw material premixing system for preparing cyclic carbonate by urea method, comprising a urea premixing system 1, a catalyst premixing system 2, a first buffer tank 3, a second buffer tank 4 and a reaction kettle 5; the urea premixing system 1 is communicated with the first buffer tank 3; the catalyst premixing system 2 is communicated with the second buffer tank 4; the first buffer tank 3 and the second buffer tank 4 are both communicated with the reaction kettle 5.

[0021] In the embodiment, the urea premixing system 1 is used for premixing propylene glycol and urea, and the premixed material is buffered in the first buffer tank 3; the catalyst premixing system 2 is used for premixing catalyst and propylene glycol, and the premixed material is buffered through the second buffer tank 4, and further, each material after premixing is sent into the reaction kettle 5 in the proportion required by production through each feeding pump for reaction; in the traditional way, urea, catalyst and propylene glycol are directly blended, which needs to be heated to about 60-80 DEG C, and at this temperature, due to the presence of catalyst, more side reactions are generated, thereby affecting the yield of the final reaction, and in the embodiment, compared with the traditional raw material blending mode, the materials are premixed respectively, that is, the reaction kettle is dissolved respectively, thereby effectively reducing the generation of side reactions in the raw material premixing stage and fully improving the yield of the final reaction.

[0022] Specifically, as shown in the figure, Figure 1 the urea premixing system 1 comprises a plurality of premixing tanks 11, a plurality of urea feeding pipes 12, a plurality of propylene glycol feeding pipes 13 and a plurality of discharge pipes 14; the urea feeding pipe 12 and the propylene glycol feeding pipe 13 are both communicated with the premixing tank 11; the premixing tank 11 is communicated with the first buffer tank 3 through the discharge pipe 14.

[0023] In the embodiment, a plurality of premixing tanks 11 are adopted to ensure the demand for material quantity for continuous production and to ensure sufficient standby material quantity when a sudden fault occurs; further, propylene glycol is pumped to the premixing tank 11 through the propylene glycol feeding pipe 13, and urea is pumped through the urea feeding pipe 12; the first buffer tank 3 is used to buffer the material and reduce the pipeline conveying pressure.

[0024] In the embodiment, the catalyst premixing system 2 is arranged and has the same principle as the urea premixing system 1, and the reflux circulation part can also be deleted according to the dissolution effect of the catalyst.

[0025] Specifically, as shown in the figure, Figure 1As shown, the urea premixing system 1 further comprises a collecting header 15, and each of the plurality of discharge pipes 14 is in communication with the collecting header 15, and the collecting header 15 is in communication with the first buffer tank 3.

[0026] In the embodiment, each of the discharge pipes 14 is provided with a flow valve, so that the flow of the material can be adjusted according to the production requirement, and further, a four-way valve is arranged at the communication position of the collecting header 15 and each of the discharge pipes 14.

[0027] Specifically, as shown, Figure 1 The plurality of premix tanks 11 are communicated two by two through a circulation system. The circulation system comprises a circulation pipe and a circulation pump, the circulation pipe is communicated between a pair of premix tanks 11, and the circulation pump is arranged in the circulation pipe. One end of the circulation pipe is in communication with the discharge pipe of one premix tank 11, and the other end of the circulation pipe is in communication with another premix tank 11.

[0028] In the embodiment, through the circulation pipe and the circulation pump, the mixed material of the upper premix tank 11 can be used for mixing with the material of the lower premix tank 11, so that the finally pumped material of each premix tank 11 is uniform, and the product quality difference caused by the difference of the pumped material of each premix tank 11 is avoided.

[0029] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A raw material premixing system for urea process for the production of cyclic carbonates, characterized by: The application relates to a urea premixing system (1), a catalyst premixing system (2), a first buffer tank (3), a second buffer tank (4) and a reaction kettle (5); the urea premixing system (1) is communicated with the first buffer tank (3); the catalyst premixing system (2) is communicated with the second buffer tank (4); the first buffer tank (3) and the second buffer tank (4) are both communicated with the reaction kettle (5).

2. A urea process feed premix system for the production of cyclic carbonates according to claim 1, characterized in that: The urea premixing system (1) comprises a plurality of premixing tanks (11), a plurality of urea feeding pipes (12), a plurality of propylene glycol feeding pipes (13) and a plurality of discharge pipes (14); the urea feeding pipes (12) and the propylene glycol feeding pipes (13) are both communicated with the premixing tanks (11); the premixing tanks (11) are communicated with the first buffer tank (3) through the discharge pipes (14).

3. A urea process raw material premix system for the production of cyclic carbonates according to claim 2, characterized in that: The urea premixing system (1) further comprises a converging main pipe (15); a plurality of the discharge pipes (14) are all communicated with the converging main pipe (15); the converging main pipe (15) is communicated with the first buffer tank (3).

4. A urea process raw material premix system for the production of cyclic carbonates according to claim 3, characterized in that: The discharge pipe (14) is provided with a flow valve at one end close to the converging main pipe (15).

5. A urea process raw material premix system for the production of cyclic carbonates according to any one of claims 2 to 4, characterized in that: A plurality of the premixing tanks (11) are communicated with each other through a circulating system.

6. A urea process raw material premix system for the production of cyclic carbonates according to claim 5, characterized in that: The circulating system comprises a circulating pipe and a circulating pump; the circulating pipe is communicated between a pair of the premixing tanks (11); the circulating pump is arranged in the circulating pipe.

7. A urea process raw material premix system for the production of cyclic carbonates according to claim 6, characterized in that: One end of the circulating pipe is communicated with a discharge pipe of one of the premixing tanks (11); the other end of the circulating pipe is communicated with another one of the premixing tanks (11).

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