Device for preparing D2 through continuous isomerization of hexafluoropropylene dimer D1

Abstract

The utility model relates to the technical field of chemical production equipment, in particular to a device for preparing D2 by continuous isomerization of hexafluoropropylene dimer D1, which comprises a D1 raw material storage tank, a solvent replenishing tank, a tubular isomerization reactor and a D2 product storage tank, the D1 raw material storage tank and the solvent supplementing tank are respectively connected with the upper input end of the tubular isomerization reactor, and the D2 product storage tank is connected with the lower output end of the tubular isomerization reactor. The device disclosed by the utility model has the beneficial effects that the continuous isomerization reaction of the hexafluoropropylene dimer D1 is realized, the conversion rate of the continuous reaction is high, the efficiency is high, meanwhile, the continuous extraction and primary separation of the D1, a reaction solvent and a catalyst are also realized in the same reactor, and the device has good social and economic benefits.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical production equipment, in particular to a device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2. Background Art

[0002] Hexafluoropropylene dimer (HFPD) and trimer are very important chemical raw materials and intermediates. They are stable in nature and can be used as solvents in many occasions. At the same time, they can also be used to prepare fluorinated surfactants with various structural uses. Compared with general surfactants, fluorinated surfactants prepared from HFPD and trimer have the characteristics of high branching, which gives them many characteristics different from ordinary surfactants. They have been widely used in many industrial fields such as petroleum, chemical, leather, textile, etc.

[0003] Due to its structural characteristics, hexafluoropropylene dimer has a variety of isomeric structures, including D1(E), D1(Z), D2, etc. In the prior art, D2 is generally prepared using D1 as a raw material. According to the reaction pressure, it can be divided into high-pressure isomerization method and normal-pressure isomerization method. However, their common problems include: (1) intermittent production method with low efficiency; (2) the post-processing process is relatively cumbersome, inefficient and with high loss. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 with high reaction efficiency and low cost.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, comprising a D1 raw material storage tank, a solvent feeding tank, a tubular isomerization reactor and a D2 product storage tank; the D1 raw material storage tank and the solvent feeding tank are respectively connected to the upper input end of the tubular isomerization reactor, and the D2 product storage tank is connected to the lower output end of the tubular isomerization reactor;

[0006] The tubular isomerization reactor comprises, from top to bottom, a material mixing and distribution layer, an upper fixed layer, a catalyst layer, a lower fixed filtering layer and an extraction and separation layer.

[0007] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, a raw material feed metering pump is provided between the D1 raw material storage tank and the upper input end of the tubular isomerization reactor.

[0008] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, a solvent replenishing metering pump is provided between the solvent replenishing tank and the upper input end of the tubular isomerization reactor.

[0009] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the tubular isomerization reactor and the D2 product storage tank are provided with a discharge control valve.

[0010] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the upper fixed layer is a wire mesh.

[0011] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the lower fixed filter layer is a wire mesh or filter cotton.

[0012] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the extraction and separation layer is a glass bead layer.

[0013] The beneficial effects of the utility model are as follows: in the device for preparing D2 by continuous isomerization of hexafluoropropylene dimer D1, the reaction raw material D1 and the catalyst are fully contacted and reacted, and the isomerization product D2 is obtained by continuous feeding reaction; at the same time, the difference in specific gravity between the reaction product D2 and the solvent is used to realize the extraction and separation of the product and the solvent inside the reactor, thereby continuously obtaining the isomerization product D2 of the reaction product hexafluoropropylene dimer D1. The device of the utility model also realizes the continuous extraction and preliminary separation of D1, the reaction solvent and the catalyst in the same reactor, and has good social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of a device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to a specific embodiment of the utility model;

[0015] Description of labels:

[0016] 1. D1 raw material storage tank; 2. Solvent replenishing tank; 3. Raw material feed metering pump; 4. Solvent replenishing metering pump; 5. Feed control valve;

[0017] 6. Tubular isomerization reactor; 61. Material mixing and distribution layer; 62. Upper fixed layer; 63. Catalyst layer; 64. Lower fixed filtration layer; 65. Extraction and separation layer;

[0018] 7. Discharge control valve; 8. D2 product storage tank. DETAILED DESCRIPTION

[0019] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0020] The utility model provides a device for preparing D2 by continuous isomerization of hexafluoropropylene dimer D1, comprising a D1 raw material storage tank, a solvent replenishing tank, a tubular isomerization reactor and a D2 product storage tank; the D1 raw material storage tank and the solvent replenishing tank are respectively connected to the upper input end of the tubular isomerization reactor, and the D2 product storage tank is connected to the lower output end of the tubular isomerization reactor;

[0021] The tubular isomerization reactor comprises, from top to bottom, a material mixing and distribution layer, an upper fixed layer, a catalyst layer, a lower fixed filtering layer and an extraction and separation layer.

[0022] Use of the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2:

[0023] 1. Prepare solvent: prepare acetonitrile solution of PEG at a ratio of 1: (20-30), wherein the PEG can be polyethylene glycol of different specifications within the range of PEG200-1000. The specific gravity of D2 to solvent is greater than 1.6; solvents with a density lower than 1.1 g / ml can be used;

[0024] 2. Fill the tubular reactor with isomerization catalyst potassium fluoride powder (requirement: KF water content ≤ 500ppm); use a metering pump to feed 0.55L solvent into the reactor, start heating after feeding, set the temperature and heat it to 140-200℃. During the heating process, as the temperature rises, the pressure will gradually increase, and the pressure value in the reactor is set to 4-6MPa; after the temperature and pressure reach the set value; set the D1 feed flow rate to 0.3-1ml / min, and the solvent feed flow rate to 0.02-0.15ml / min. After passing through the catalyst layer, the material fully reacts and enters the lower extraction and separation layer. The product D2 and the solvent are initially extracted and separated. The lower part is the product D2 layer, which is automatically discharged to the product storage tank by the automatic pressure regulating valve.

[0025] The beneficial effects of the utility model are as follows: in the device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the reaction raw material D1 is fully contacted with the catalyst for reaction, and the isomerization product D2 is obtained by continuous feeding reaction; at the same time, the difference in specific gravity between the reaction product D2 and the solvent is utilized to realize extraction and separation of the product and the solvent inside the reactor, thereby continuously obtaining the isomerization product D2 of the reaction product hexafluoropropylene dimer D1.

[0026] According to the kinetic study of D1 isomerization, D1 isomerization is a 1.5-level reaction, and the traditional kettle process is a full mixed flow, which leads to a very slow reaction in the later stage. In the form of a fixed bed, D1 will only flow downward, with little back mixing, thereby improving the reaction efficiency. And in conjunction with the characteristics of the difference in specific gravity between the reaction product and the solvent in the reaction of this application, reaction-extraction coupling is realized. The catalyst is a powder, and in other prior art documents, filtration treatment is required. This application adopts a fixed bed form, and the reactant only passes through the catalyst layer, and the catalyst will not be taken out, thereby avoiding subsequent catalyst separation and simplifying the steps. This application uses a reaction-separation coupling technology, and the reactant is directly separated from acetonitrile in the reactor, and the principle of density difference is used to trap acetonitrile inside the reactor, and acetonitrile can be repeatedly recycled, thereby reducing the circulation amount of acetonitrile.

[0027] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, a raw material feed metering pump is provided between the D1 raw material storage tank and the upper input end of the tubular isomerization reactor.

[0028] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, a solvent replenishing metering pump is provided between the solvent replenishing tank and the upper input end of the tubular isomerization reactor.

[0029] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the tubular isomerization reactor and the D2 product storage tank are provided with a discharge control valve.

[0030] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the upper fixed layer is a wire mesh.

[0031] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the lower fixed filter layer is a wire mesh or filter cotton.

[0032] Furthermore, in the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, the extraction and separation layer is a glass bead layer.

[0033] From the above description, it can be seen that the lower extraction and separation layer plays a role in fixing the catalyst layer and preventing the catalyst from being lost.

[0034] Embodiment 1:

[0035] See also Figure 1 , a device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, comprising a D1 raw material storage tank 1, a solvent replenishing tank 2, a tubular isomerization reactor 6 and a D2 product storage tank 8; the D1 raw material storage tank 1 and the solvent replenishing tank 2 are respectively connected to the upper input end of the tubular isomerization reactor 6, and the D2 product storage tank 8 is connected to the lower output end of the tubular isomerization reactor 6;

[0036] A raw material feed metering pump 3 is provided between the D1 raw material storage tank 1 and the upper input end of the tubular isomerization reactor 6. A solvent replenishing metering pump 4 is provided between the solvent replenishing tank 2 and the upper input end of the tubular isomerization reactor 6. A discharge control valve 7 is provided between the tubular isomerization reactor 6 and the D2 product storage tank 8. The D1 raw material storage tank 1 and the solvent replenishing tank 2 are connected in parallel to the upper input end of the tubular isomerization reactor 6, and a feed control valve 5 is provided on the parallel pipeline;

[0037] The tubular isomerization reactor 6 includes, from top to bottom, a material mixing and distribution layer 61 , an upper fixed layer 62 , a catalyst layer 63 , a lower fixed filtering layer 64 and an extraction and separation layer 65 .

[0038] The upper fixed layer is a wire mesh, the lower fixed filter layer is a wire mesh or filter cotton, and the extraction and separation layer is a glass bead layer or other fillers.

[0039] Use of the above-mentioned device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2:

[0040] Filling an isomerization catalyst into a tubular reaction system, wherein the isomerization catalyst is potassium fluoride powder; (requirement: KF water content ≤ 500ppm);

[0041] Use a metering pump to feed 0.55L of solvent into the reactor. The solvent is an acetonitrile solution of PEG prepared at a mass ratio of 1: (20-30). After the feeding is completed, the temperature is raised to 140-200°C;

[0042] During the heating process, as the temperature rises, the pressure will gradually increase. The pressure value in the reactor is set to 4-6MPa. After the temperature and pressure reach the set values, the D1 feed flow rate is set to 0.3-1ml / min, and the solvent feed flow rate is set to 0.02-0.15ml / min. After the material passes through the catalyst layer, it fully reacts and enters the lower extraction and separation layer. The product D2 and the solvent are initially extracted and separated. The lower part is the product D2 layer, which is automatically discharged to the product storage tank by the automatic pressure regulating valve.

[0043] 1. Set different usage conditions. The specific usage process is as follows:

[0044] Use a metering pump to feed 0.55L of solvent into the reactor. After the feeding is completed, turn on the temperature increase and set the temperature to 140°C. The pressure value in the reactor is 4.0MPa. After the temperature and pressure reach the set values, set the D1 feed flow rate to 0.3ml / min and the solvent feed flow rate to 0.02ml / min. After the reaction proceeds smoothly, continue to discharge 0.32ml / min.

[0045] The product was collected, named as product #1, and analyzed.

[0046] 2. Set different usage conditions. The specific usage process is as follows:

[0047] Use a metering pump to feed 0.55L of solvent into the reactor. After the feeding is completed, turn on the temperature increase and set the temperature to 140°C. The pressure value in the reactor is 6.0MPa. After the temperature and pressure reach the set values, set the D1 feed flow rate to 0.3ml / min and the solvent feed flow rate to 0.02ml / min. After the reaction proceeds smoothly, the discharge is continuously about 0.32ml / min.

[0048] The product was collected, named as product #2, and analyzed.

[0049] The above product analysis results are shown in Table 1 below:

[0050] Table 1

[0051]

[0052] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2, characterized in that: It includes a D1 raw material storage tank, a solvent feeding tank, a tubular isomerization reactor and a D2 product storage tank; the D1 raw material storage tank and the solvent feeding tank are respectively connected to the upper input end of the tubular isomerization reactor, and the D2 product storage tank is connected to the lower output end of the tubular isomerization reactor; The tubular isomerization reactor comprises, from top to bottom, a material mixing and distribution layer, an upper fixed layer, a catalyst layer, a lower fixed filtering layer and an extraction and separation layer.

2. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: A raw material feed metering pump is provided between the D1 raw material storage tank and the upper input end of the tubular isomerization reactor.

3. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: A solvent replenishing metering pump is provided between the solvent replenishing tank and the upper input end of the tubular isomerization reactor.

4. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: The tubular isomerization reactor and the D2 product storage tank are provided with discharge control valves.

5. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: The upper fixed layer is a wire mesh.

6. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: The lower fixed filter layer is a wire mesh or filter cotton.

7. The device for continuously isomerizing hexafluoropropylene dimer D1 to prepare D2 according to claim 1, characterized in that: The extraction and separation layer is a glass bead layer.

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