Cyclopentadiene polymerization device

Abstract

The invention relates to the technical field of polymerization reaction kettles, in particular to a cyclopentadiene polymerization device which comprises a rectifying tower, a heating mechanism and a plurality of partition cavities communicated with one another are arranged in a tower kettle of the rectifying tower, and the heating mechanism enables the temperature of materials in the partition cavities communicated with one another to be sequentially increased in the flowing direction of liquid-phase materials; the rectifying tower is used as a reactor, the tower kettle of the rectifying tower is used as a distillation separation mechanism, cyclopentadiene can stay at different temperature stages, high selectivity can be achieved at low temperature, high reaction efficiency at high temperature can be guaranteed, isoprene and m-pentadiene are prevented from forming copolymerization or forming impurities in dicyclopentadiene by self-polymer, and the yield of cyclopentadiene is improved. Furthermore, dicyclopentadiene with relatively high purity is produced, and continuous production of a high-purity product is realized.

Description

Technical Field

[0001] The invention relates to the technical field of polymerization reactors, in particular to a cyclopentadiene polymerization device. Background Art

[0002] The preparation of high-purity dicyclopentadiene (DCPD purity greater than 95% or DCPD purity greater than 99.5%) from industrial-grade dicyclopentadiene (DCPD purity greater than 78%) primarily utilizes a depolymerization-dimerization-purification process. This process involves first depolymerizing DCPD to convert it into cyclopentadiene (CPD). Simultaneously, most of the other co-dimers (Xd, a general term for substances produced by the reaction of isoprene, isoprene, and cyclopentadiene) are also depolymerized to monomers. The depolymerization products are then distilled to obtain high-purity CPD. The high-purity CPD is then dimerized. Because the dimerization rate of cyclopentadiene is greater than that of other copolymers, DCPD is separated from copolymers with similar boiling points, thereby increasing the purity of the DCPD. The high-purity DCPD is then obtained by distillation.

[0003] Taking advantage of cyclopentadiene's spontaneous dimerization, dicyclopentadiene can be converted to dicyclopentadiene, which can then be purified by distillation. From an engineering perspective, heating is necessary to accelerate the dimerization reaction. However, heating leads to copolymerization between cyclopentadiene and other C5 dienes and alkenes. The products produced by these reactions have boiling points very close to dicyclopentadiene, making it difficult to obtain a high-purity dicyclopentadiene product even with vacuum distillation.

[0004] Therefore, a cyclopentadiene polymerization device is needed to promote the dimerization of cyclopentadiene but inhibit other substances (isoprene, piperylene) from dimerizing or copolymerizing with cyclopentadiene. Summary of the Invention

[0005] In order to solve the above problems, an embodiment of the present invention provides a cyclopentadiene polymerization device, which achieves the purpose of solving the problems raised in the background technology.

[0006] In order to achieve the above objectives, the embodiments of the present invention specifically adopt the following technical solutions:

[0007] A cyclopentadiene polymerization device comprises a distillation tower, wherein a heating mechanism and a plurality of interconnected partition chambers are provided in the bottom of the distillation tower. The heating mechanism increases the temperature of the materials in the interconnected partition chambers in sequence along the flow direction of the liquid phase materials.

[0008] Furthermore, a plurality of partition plates are provided in the bottom of the distillation tower, and the plurality of partition plates divide the bottom into a plurality of mutually connected partition chambers.

[0009] Furthermore, the partition plates are arched plates, and the heights of the plurality of partition plates decrease sequentially along the flow direction of the liquid phase material.

[0010] Furthermore, the partition plates are circular, and each partition plate is provided with an array of communication holes, wherein the communication holes are connected to the partition chambers on the partition plate side.

[0011] Furthermore, the distillation tower is provided with a cooling reflux mechanism at the upper end, the lower end is connected to the tower kettle, the middle part is provided with a raw material feeding pipe, and the lower part is provided with a diluent feeding pipe.

[0012] Furthermore, the cooling reflux mechanism is provided with a gas phase extraction pipeline and a liquid phase extraction pipeline.

[0013] Furthermore, the diluent feeding tube is used to add water and / or acetonitrile.

[0014] Furthermore, it also includes an inhibitor adding mechanism, and the discharge pipe of the inhibitor adding mechanism is communicated with the separation chamber in the middle of the tower kettle.

[0015] Furthermore, the polymerization inhibitor adding mechanism volatilizes the polymerization inhibitor by heating, and the polymerization inhibitor vapor enters the tower kettle.

[0016] Furthermore, a stirring mechanism is provided in each of the partition chambers.

[0017] Furthermore, the stirring mechanism is a turbine stirrer.

[0018] The beneficial effects of the embodiments of the present invention are:

[0019] 1. The present invention uses a distillation tower as a reactor and the bottom of the distillation tower as a distillation separation mechanism, which can make cyclopentadiene stay at different temperature stages, can achieve high selectivity at low temperatures, and can ensure high reaction efficiency at high temperatures, thereby preventing isoprene and piperylene from forming copolymers or self-polymers to form impurities in dicyclopentadiene, thereby producing dicyclopentadiene with higher purity.

[0020] 2. The present invention adds a polymerization inhibitor to the tower kettle to prevent the formation of polymers during the evaporation process and ensure the purity of dicyclopentadiene during the separation process.

[0021] 3. The present invention adds a diluent to the lower part of the distillation tower, which, on the one hand, makes the separation of cyclopentadiene and dicyclopentadiene more complete, and on the other hand, can also separate the polymerization inhibitor from cyclopentadiene, thereby preventing the polymerization inhibitor from affecting the polymerization reaction of cyclopentadiene. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 This is a sectional front view of the distillation tower in Example 1 of the present invention;

[0024] Figure 3 for Figure 2 AA section view;

[0025] Figure 4 This is a sectional front view of the distillation tower in Example 2 of the present invention;

[0026] Figure 5 for Figure 4 BB cross-sectional view.

[0027] In the figure: 1. Distillation tower; 2. Tower body; 3. Cooling reflux mechanism; 4. Tower bottom; 5. Raw material feeding pipe; 6. Gas phase extraction pipeline; 7. Liquid phase extraction pipeline; 8. Heating mechanism; 9. Partition chamber; 10. Stirring mechanism; 11. Partition plate; 12. Connecting hole; 13. Inhibitor adding mechanism; 14. Discharge pipe; 15. Diluent feeding pipe. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] Example 1: See Figure 1 of Figure 2 As shown, an embodiment of the present invention discloses a cyclopentadiene polymerization device, comprising a distillation tower 1, wherein the distillation tower comprises a tower body 2 and a tower reactor 4, wherein the tower body 2 of the distillation tower 1 is provided with a cooling reflux mechanism 3 at the upper end, is connected to the tower reactor 4 at the lower end, and is provided with a raw material feeding pipe 5 in the middle, wherein a gas phase production pipeline 6 and a liquid phase production pipeline 7 are provided on the cooling reflux mechanism 3, wherein the gas phase production pipeline 6 is used to produce isoprene, and the liquid phase production pipeline 7 is used to produce piperylene;

[0030] The distillation tower 1 is not provided with a bottom reboiler, but a heating mechanism 8 is provided in the tower kettle 4. The heating mechanism 8 is a jacketed heating mechanism or a coil heating mechanism filled with heat transfer oil to achieve heat supplement. The tower kettle 4 is also provided with a plurality of interconnected partition chambers 9. The partition chamber 9 is used to divide the tower kettle liquid into different sections, so that the temperature of the material in each section of the partition chamber gradually increases from one end to the other end, thereby achieving the separation and purification of dicyclopentadiene. The different temperatures are achieved by heating by the heating mechanism 8. The heating mechanism 8 can uniformly heat all the partition chambers 9 by entering the heat transfer medium from the right end and exiting the heat transfer medium from the left end, or can heat each partition chamber 9 separately, and can achieve the material temperature in multiple partition chambers 9 being higher on the left and lower on the right. A stirring mechanism 10 is provided in each of the partition chambers 9. The stirring mechanism 10 can be selected from the existing technology, among which a turbine agitator has a better effect.

[0031] In this embodiment, the cyclopentadiene raw material enters the feed port of the distillation tower 1, and the temperature at the upper end of the tower body 2 is 42°C and the temperature at the lower end is 100°C. Under this temperature gradient, the cyclopentadiene undergoes multiple stages of temperature increase, and the selectivity is higher at a lower temperature (40-60°C). At the same time, the cracked isoprene and isoprene are enriched at the top of the tower and then extracted by the cooling reflux mechanism to avoid flowing downward to the high-temperature area. The polymerization rate increases at a medium temperature (60-80°C), and the polymerization efficiency is accelerated at a higher temperature (80-100°C). In the tower kettle 4, the temperature in multiple partition chambers 9 gradually increases, so that the unpolymerized cyclopentadiene is distilled out, leaving only dicyclopentadiene with higher purity, so as to achieve the polymerization rate and higher purity required by the industry.

[0032] like Figure 2 and Figure 3 As shown, in this embodiment, a plurality of partition plates 11 are provided in the bottom 4 of the distillation tower 1. The partition plates 11 are arched plates. The plurality of partition plates 11 divide the bottom 4 into a plurality of partition chambers 9 which are interconnected at the upper ends, and the upper ends of the plurality of partition plates 11 gradually lower from right to left.

[0033] Such a partition plate 11 prevents the materials in each partition chamber 9 from mixing with each other, and can ensure the temperature gradient of the materials in two adjacent partition chambers 9, thereby achieving the purification of dicyclopentadiene.

[0034] Example 2: This example is basically the same as Example 1, and the similarities are not repeated here. The differences are:

[0035] like Figure 4 and Figure 5 As shown, the partition plate 11 is circular, and each partition plate 11 is provided with an array of communication holes 12 , and the communication holes 12 are connected to the partition chambers 9 on both sides of the partition plate 11 .

[0036] The partition chambers 9 on the left and right sides of the partition plate 11 are connected through the connecting holes 12. The lower connecting holes 12 are used to allow the liquid phase to flow to compensate for the liquid level lowered due to the discharge of the product, and the upper connecting holes 12 are used to allow steam to circulate. Compared with the first embodiment, this embodiment can reduce the generation of polymers, so that the liquid phase in the tower bottom 4 is close to a piston flow rather than an overflow state, avoiding the liquid phase product from being in a high-temperature state for a long time to form polymers.

[0037] Example 3: This example is improved on the basis of Example 1 and can also be applied to Example 2.

[0038] There is also an inhibitor adding mechanism 13 on the side of the distillation tower 1, and the discharge pipe 14 of the inhibitor adding mechanism 13 is connected to the partition chamber 9 in the middle of the tower kettle 4. The inhibitor adding mechanism 13 volatilizes the inhibitor by heating, and the inhibitor vapor enters the tower kettle 4; the inhibitor is N,N-diethylhydroxylamine, which has a boiling point of 125-130°C, and the temperature of the vapor entering the tower kettle 4 is not much different from that of the tower kettle.

[0039] After the polymerization inhibitor vapor enters the tower kettle 4, it participates in the gas phase circulation under the impetus of the vapor in the tower kettle 4, moves upward through the tower plate and transfers heat, and then flows back to the bottom of the tower kettle 4 with the liquid phase. Then, it is gradually heated as the liquid phase flows through the multiple partition chambers 9 in the tower kettle 4, and the production of polymers of dicyclopentadiene in the liquid phase is suppressed during the heating process.

[0040] Example 4: In the above embodiment, because the boiling points of dicyclopentadiene and cyclopentadiene are quite different, fewer tower plates are required. During the distillation process, not only are the working conditions prone to fluctuations and the operational stability is poor, but the inhibitor vapor is also prone to rise to the middle of the tower body, thereby inhibiting the polymerization of cyclopentadiene, seriously inhibiting the polymerization reaction and affecting production efficiency.

[0041] Therefore, a diluent feeding pipe 15 is provided at the lower part of the tower body 2 of the distillation tower 1. The diluent feeding pipe 15 has a valve, and the end of the diluent feeding pipe is connected to a pump or other liquid material conveying mechanism and container. The diluent feeding pipe 15 is used to add water, acetonitrile or a mixture of water and acetonitrile; wherein the diluent is added only once, rather than continuously.

[0042] Compared with Examples 1 to 3, this embodiment requires a taller distillation tower 1 having more plates, wherein the diluent circulates in the tower body 2, which increases the reaction time of cyclopentadiene and the high-temperature reaction rate, and isolates the polymerization inhibitor to prevent the polymerization inhibitor from affecting the polymerization of cyclopentadiene monomer.

[0043] In this embodiment, the temperature at the upper end of the tower body 2 is 42° C. and the temperature at the lower end is 100° C. However, due to the addition of a diluent, the azeotropic point of dicyclopentadiene and water is 98° C. (gas phase water content is about 57%), and the azeotropic point of acetonitrile and water is 76° C. (gas phase water content is about 13%). Therefore, the temperature gradient in the tower body 2 can be reduced, and the operational stability in the tower body 2 can be increased. At the same time, the addition of the diluent allows acetonitrile to be diluted in the liquid phase in the medium temperature section (60-80° C.) of the tower body 2, and water exists in the liquid phase in the high temperature section (80-100° C.), which can intercept the polymerization inhibitor and make it more concentrated near the bottom 4, thereby reducing the influence of the polymerization inhibitor on the middle part of the tower body 2. Therefore, although a diluent is added to the distillation tower 1, the polymerization is smoothly carried out with the addition of the polymerization inhibitor.

[0044] It should be noted that, in the description of the present invention, terms such as "center, up, down, left, right, vertical, horizontal, inside, outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as limiting the present invention. The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, so that a process, article or device / apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or also includes elements inherent to such process, article or device / apparatus.

[0045] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A cyclopentadiene polymerization device, characterized in that: The invention comprises a distillation tower (1), wherein a heating mechanism (8) and a plurality of mutually connected partition chambers (9) are provided in the tower kettle (4) of the distillation tower (1), and the heating mechanism (8) causes the temperature of the material in the mutually connected partition chambers (9) to increase in sequence along the flow direction of the liquid phase material.

2. The cyclopentadiene polymerization device according to claim 1, characterized in that: A plurality of partition plates (11) are provided in the tower bottom (4) of the distillation tower (1), and the plurality of partition plates (11) divide the tower bottom (4) into a plurality of mutually connected partition chambers (9).

3. The cyclopentadiene polymerization device according to claim 2, characterized in that: The partition plates (11) are arched plates, and the heights of the plurality of partition plates (11) decrease sequentially along the flow direction of the liquid phase material.

4. The cyclopentadiene polymerization device according to claim 2, characterized in that: The partition plates (11) are circular, and each partition plate (11) is provided with an array of communication holes (12), wherein the communication holes (12) are connected to the partition cavities (9) on both sides of the partition plate (11).

5. The cyclopentadiene polymerization device according to claim 1, characterized in that: It also includes a polymerization inhibitor adding mechanism (13), the discharge pipe of the polymerization inhibitor adding mechanism (13) is communicated with the separation chamber (9) in the middle of the tower still (4).

6. The cyclopentadiene polymerization device according to claim 5, characterized in that: The polymerization inhibitor adding mechanism (13) volatilizes the polymerization inhibitor by heating, and the polymerization inhibitor vapor enters the tower kettle (4).

7. The cyclopentadiene polymerization device according to claim 1, characterized in that: The tower body (2) of the distillation tower (1) is provided with a cooling reflux mechanism (3) at the upper end, is connected to the tower kettle (4) at the lower end, is provided with a raw material feeding pipe (5) in the middle, and is provided with a diluent feeding pipe (15) at the lower part.

8. The cyclopentadiene polymerization device according to claim 7, characterized in that: The cooling reflux mechanism (3) is provided with a gas phase extraction pipeline (6) and a liquid phase extraction pipeline (7).

9. The cyclopentadiene polymerization device according to claim 7, characterized in that: The diluent feeding pipe (15) is used to add water and / or acetonitrile.

10. The cyclopentadiene polymerization device according to claim 1, characterized in that: A stirring mechanism (10) is provided in each of the partition chambers (9).

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