Polymerization apparatus and polymerization process

Abstract

The present application relates to the field of olefin polymerization, in particular to a polymerization device and a polymerization method, the device comprising a polymerization reactor, the polymerization reactor comprising a polymer monomer stream feeding port at the end and a feeder of an initiator and solvent containing stream arranged through the wall of the polymerization reactor, the feeder being partially closed at the end inside the polymerization reactor and being provided with an opening at the side; wherein the opening makes the discharge direction of the feeder and the central axis of the flow channel of the polymer monomer stream in the polymerization reactor form an angle of > 90°. The polymerization device provided by the present application realizes the rapid mixing of the polymerization material and the polymer monomer by improving the structure of the feeder, improves the mixing efficiency of the polymerization material and the polymer monomer, thereby improving the use efficiency of the polymerization material and reducing the consumption of the polymerization material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of olefin polymerization, in particular to a polymerization reaction device and a polymerization reaction method. BACKGROUND

[0002] Low density polyethylene has a special molecular chain structure, and has excellent transparency, chemical inertness, dielectric properties and processability, and is widely used in the fields of film, wire and cable, injection molding, coating and the like. The production conditions of low density polyethylene are harsh, for example, when a tubular reactor is used, the typical reaction pressure is about 1700 bar to 3000 bar, and the reaction temperature is as high as 310-350℃.

[0003] For the art, the free radical initiator is the key to high pressure ethylene free radical polymerization, and a plurality of free radical initiators are usually compounded for use to reduce the consumption of the initiator, while providing a low density polyethylene product with good physical and chemical properties. In the world, the initiators used for high pressure free radical polymerization of ethylene include one or a mixture of organic peroxide, oxygen, air, among which the organic peroxide is the most commonly used free radical initiator.

[0004] The decomposition rate of the free radical initiator follows the Arrhenius equation. If the decomposition rate of the free radical initiator and the residence time of the reactor do not match, various problems will be caused. For example, at a lower reaction temperature, the decomposition rate of the free radical initiator is low, which can cause the ethylene polymerization reaction to be unable to be initiated; at a too high reaction temperature, the free radical initiator decomposes too fast, which can cause a large amount of free radicals generated by the decomposition of the initiator to be unable to contact with ethylene, thereby causing low initiator efficiency, poor economy, and affecting product quality.

[0005] EP 0449092 provides a conventional initiator injection nozzle, and the mixing efficiency of the initiator and the reaction medium is low, and the use efficiency of the initiator is poor. In order to improve the use efficiency of the initiator, CN1236846C impinges two flowing media on each other at a certain angle upstream of the initiator injection point, or arranges a vortex element in the flow passage, so as to form a rotating fluid upstream of the initiator injection point, thereby achieving the purpose of rapidly dispersing the initiator. However, the method has a complex structure and high maintenance cost. CN102369055B discloses an initiator injection nozzle, however, the structure of the nozzle forms an initiator fluid flow channel at the tip, and the fluid direction is not well matched with the flow direction of the main flowing medium in the mixer, and the use efficiency of the initiator is limitedly improved. SUMMARY

[0006] The purpose of the present application is to overcome the problems of poor dispersion of the initiator and large consumption in the olefin polymerization process in the prior art, and to provide a polymerization reaction device and a polymerization reaction method, which have the effects of good dispersion of the polymerization material and small consumption in the polymerization reaction process.

[0007] To achieve the above object, the first aspect of the present application provides a polymerization device, which comprises a polymerization reactor, the polymerization reactor comprising a polymer monomer stream feeding port at the end and a feeding device of a stream containing initiator and solvent arranged through the wall of the polymerization reactor, the feeding device being partially closed at the end inside the polymerization reactor and having an opening arranged at the side.

[0008] The opening is such that the angle between the discharging direction of the feeding device and the central axis of the flow channel of the polymer monomer stream in the polymerization reactor is ≥ 90°.

[0009] The second aspect of the present application provides a polymerization method, which is carried out in the device described in the present application, the method comprising: sending the stream containing initiator and solvent from the feeding device into the flow channel of the polymer monomer stream in the polymerization reactor and reacting with the polymer monomer fed from the polymer monomer feeding port at the end of the polymerization reactor.

[0010] By the above technical solution, the present application has the following advantages:

[0011] The polymerization device provided by the present application realizes the rapid mixing of the polymerization material and the polymer monomer through the unique structure of the feeding device, improves the mixing efficiency of the polymerization material and the polymer monomer, thereby improving the use efficiency of the polymerization material, reducing the consumption of the polymerization material, improving the economy of the device, avoiding the local concentration of the polymerization material being too high through the rapid dispersion of the polymerization material and the polymer monomer, inhibiting the generation of temperature hot spots, improving the safety of the device, and ensuring the stability of the product quality. In the preferred scheme, the reaction rate and temperature curve of each elementary reaction downstream of the outlet of the mixing unit are well matched through the matching of the parameters and flow structure in the flow channel, further realizing the stability of the reaction temperature.

[0012] The device of the present application is particularly suitable for the polymerization reaction of ethylene as the polymer monomer, and the device can greatly increase the efficiency of ethylene polymerization and has low initiator consumption and a more stable state of the reactor. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic diagram of a polymerization device according to a preferred embodiment of the present application;

[0014] Figure 2 is a schematic diagram of the structure of a feeding device according to a preferred embodiment of the present application;

[0015] Figure 3 is a schematic diagram of the structure of a polymerization reactor according to a preferred embodiment of the present application.

[0016] BRIEF DESCRIPTION OF DRAWINGS

[0017] 1. Circulating feed compressor; 2. Primary compressor;

[0018] 3. Secondary compressor; 4. Preheater;

[0019] 5. First tubular reactor; 6a. Second tubular reactor;

[0020] 6b. Third tubular reactor; 7. High pressure relief valve;

[0021] 8. Cooler; 9. High pressure separator;

[0022] 10. High pressure recycle loop; 11. Low pressure separator;

[0023] 12. Low pressure recycle loop; 20a. First feeder inlet;

[0024] 20b. Second feeder inlet; 21a. First feeder housing;

[0025] 21b. Second feeder housing; 22a. First feed chamber;

[0026] 22b. Second feed chamber; 23a. First feeder outlet;

[0027] 23b1. Second feeder outlet; 23b2. Third feeder outlet;

[0028] 31. Polymerization reactor; 32. Polymerization reactor converging section;

[0029] 33. Polymerization reactor throat section; 34. Polymerization reactor diverging section;

[0030] 35. Polymerization reactor outlet. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application will now be described in detail with reference to the drawings. It should be appreciated that the detailed description of the specific embodiments is merely intended for explanation and illustration and is not intended to limit the present application.

[0032] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The approximate values allow for variation based on experimental error, measurement techniques, and the like. Variations of the approximate values are understood to be from about 0 to about 10% of the approximate value. Within this context, the term about means that the value can be the exact value or about 0 to about 10% of the value. For numerical ranges that include endpoints, each intervening value will be understood to be included in the range. For ranges using both endpoints and intervening values, the ranges are understood to include the endpoints and intervening values.

[0033] The first aspect of the present application provides a polymerization device, which comprises a polymerization reactor, wherein the polymerization reactor comprises a polymer monomer stream feeding port at an end and a feeder of an initiator and solvent containing stream arranged through the wall of the polymerization reactor, and the feeder is partially closed at the end inside the polymerization reactor and is provided with an opening at the side.

[0034] The opening is such that the angle between the discharge direction of the feeder and the central axis of the flow channel of the polymer monomer stream in the polymerization reactor is ≥90°, for example, it can be 90°, 100°, 110°, 130°, 150°, 160°, 170°, or 180°.

[0035] The polymerization device provided by the present application realizes rapid mixing of the polymerization material and the polymer monomer by improving the structure of the feeder, improves the mixing efficiency of the polymerization material and the polymer monomer, thereby improving the use efficiency of the polymerization material, reducing the consumption of the polymerization material, improving the economy of the device, avoiding local high concentration of the polymerization material by rapid dispersion of the polymerization material and the polymer monomer, inhibiting the generation of temperature hot spots, improving the safety of the device, and ensuring stable product quality.

[0036] According to a particularly preferred embodiment of the present application, the opening is such that the angle between the discharge direction of the feeder and the central axis of the flow channel of the polymer monomer stream in the polymerization reactor is ≥150°, preferably 150°-180°, for example, it can be 150°, 160°, 170°, or 180°. By adopting the foregoing preferences, the utilization efficiency of the polymerization material can be further improved, and stable product quality can be ensured.

[0037] According to a preferred embodiment of the present application, the polymerization reactor comprises, in sequence along the material flow direction, a contraction structure, a throat structure, and an expansion structure.

[0038] In the present application, as long as the purpose of the present application can be achieved, the length ratio of the contraction structure, the throat structure, and the expansion structure is not particularly limited. According to a preferred embodiment of the present application, the length ratio of the contraction structure and the throat structure is 0.1:1-10:1, and the length ratio of the contraction structure and the expansion structure is 0.2:1-5:1. By adopting the foregoing preferences, the utilization efficiency of the polymerization material can be further improved, and stable product quality can be ensured.

[0039] According to a preferred embodiment of the present application, the inlet pipe diameter of the contraction structure is 40-50 mm, and the inlet material flow of the contraction structure is 20-200 t / h.

[0040] According to a preferred embodiment of the present application, the converging angle of the converging structure is 10°-70°, for example, 50°, 60°, or 70°. By adopting the foregoing preferences, the utilization efficiency of the polymerization material can be further improved, and the product quality can be ensured to be stable.

[0041] According to a preferred embodiment of the present application, the diverging angle of the diverging structure is 10°-40°, for example, 20°, 30°, or 40°. By adopting the foregoing preferences, the utilization efficiency of the polymerization material can be further improved, and the product quality can be ensured to be stable.

[0042] In the present application, the converging angle refers to the taper angle of the converging structure of the polymerization reactor, and the diverging angle refers to the taper angle of the diverging structure of the polymerization reactor. The converging angle refers to the included angle formed by the intersection of two generatrices of the converging structure, and the diverging angle refers to the included angle formed by the intersection of two generatrices of the diverging structure.

[0043] In the present application, the ratio of the length to the inner diameter of the throat structure is not particularly limited as long as the purpose of the present application can be achieved. According to a preferred embodiment of the present application, the ratio of the length to the inner diameter of the throat structure is 0.01-20:1, preferably 0.5:1-10:1. By adopting the foregoing preferences, the utilization efficiency of the polymerization material can be further improved, and the product quality can be ensured to be stable.

[0044] According to a particularly preferred embodiment of the present application, the central axis of the feeder intersects the central axis of the flow channel of the polymerization monomer stream in the polymerization reactor, and the intersection point is located in the converging structure.

[0045] According to a particularly preferred embodiment of the present application, the number of the feeders is preferably 1-5, and more preferably, when there are multiple feeders, the feeders are arranged in parallel or staggered in the converging structure.

[0046] According to a particularly preferred embodiment of the present application, the polymerization device comprises multiple polymerization reactors connected in series, preferably 2-5 polymerization reactors connected in series.

[0047] Parallel arrangement refers to that the central axes of different feeders are parallel.

[0048] Staggered arrangement refers to that the central axes of different feeders have a certain included angle.

[0049] According to a particularly preferred embodiment of the present application, the device further comprises a polymerization material supply unit and a feeding pump, which are used to provide a stream containing an initiator and a solvent and inject the stream into the feeder.

[0050] According to a particularly preferred embodiment of the present application, the outlet pressure of the feed pump is 200-300 MPa, and the outlet pressure of the feed pump is higher than the inlet pressure of the polymerization reactor.

[0051] According to a particularly preferred embodiment of the present application, the feeder comprises a shell and a feed cavity defined by the shell, and the shell is provided with a material inlet communicating with the feed cavity and at least one opening on the side surface.

[0052] According to a particularly preferred embodiment of the present application, the shell is provided with 1-5 openings on the side surface.

[0053] According to a particularly preferred embodiment of the present application, the polymerization reactor is a tubular reactor.

[0054] The second aspect of the present application provides a polymerization method, which is carried out in the device of the present application, and the method comprises: feeding a stream containing an initiator and a solvent from the feeder into the flow channel of the polymerization monomer stream in the polymerization reactor to react with the polymerization monomer fed from the polymerization monomer feeding port at the end of the polymerization reactor.

[0055] By using the method of the present application, the mixing efficiency of the polymerization material and the polymerization monomer can be further improved, the utilization efficiency of the polymerization material can be improved, the consumption of the polymerization material can be reduced, the local concentration of the polymerization material can be avoided, the generation of temperature hot spots can be inhibited, and the product quality can be ensured stable.

[0056] According to a particularly preferred embodiment of the present application, the outlet flow velocity of the opening on the side surface of the feeder is 5-30 m / s. By adopting the foregoing preferred, the utilization efficiency of the polymerization material can be further improved, and the product quality can be ensured stable.

[0057] According to a particularly preferred embodiment of the present application, the outlet flow velocity of the opening on the side surface of the feeder is 10-15 m / s.

[0058] According to a particularly preferred embodiment of the present application, the minimum flow velocity of the material in the flow channel of the polymerization monomer stream in the polymerization reactor is 5-20 m / s. By adopting the foregoing preferred, the utilization efficiency of the polymerization material can be further improved, and the product quality can be ensured stable.

[0059] According to a particularly preferred embodiment of the present application, the minimum flow velocity of the material in the flow channel of the polymerization monomer stream in the polymerization reactor is 8-16 m / s.

[0060] According to a particularly preferred embodiment of the present application, the ratio of the maximum flow rate to the minimum flow rate of the material in the flow channel of the polymerization monomer stream in the polymerization reactor is 1:1.05-9:1. By adopting the foregoing preference, the utilization efficiency of the polymerization material can be further improved and the product quality can be ensured to be stable.

[0061] According to a particularly preferred embodiment of the present application, the ratio of the discharge flow rate of the side opening of the feeder to the minimum flow rate of the material in the flow channel of the polymerization monomer stream in the polymerization reactor is 1:4-6:1. By adopting the foregoing preference, the utilization efficiency of the polymerization material can be further improved and the product quality can be ensured to be stable.

[0062] In the present application, the quality of the initiator and the solvent discharged from the feeding unit is not particularly limited. According to a particularly preferred embodiment of the present application, the mass ratio of the initiator to the solvent in the stream containing the initiator and the solvent is 5:95-40:60, preferably 15:85-30:70.

[0063] According to a particularly preferred embodiment of the present application, the polymerization monomer is selected from the group consisting of olefins having 2-16 carbon atoms, preferably olefins having 2-8 carbon atoms.

[0064] According to a particularly preferred embodiment of the present application, the polymerization monomer stream contains the polymerization monomer and the telogen, wherein the mass ratio of the telogen to the polymerization monomer is 0-0.05.

[0065] In the present application, the organic peroxide is a conventional selection in the art as long as the object of the present application can be achieved. According to a particularly preferred embodiment of the present application, the initiator is an organic peroxide having a temperature of half-life per hour of 56-150°C, preferably an organic peroxide having a temperature of half-life per hour of 60-150°C, and more preferably an organic peroxide having a temperature of half-life per hour of 63-145°C. By adopting the foregoing preference, the utilization efficiency of the polymerization material can be further improved.

[0066] According to a preferred embodiment of the present application, the organic peroxide includes peroxy ester, peroxy ketal, peroxy ketone and peroxy carbonate, and the organic peroxide can be selected from at least one of di(2-ethylhexyl) peroxydicarbonate, di-cyclohexyl peroxydicarbonate, diacetyl peroxydicarbonate, t-butyl peroxyisopropylcarbonate, di-t-butyl peroxide, di-t-amyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hex-3-yne, 1,3-diisopropyl monohydroperoxide or t-butyl hydroperoxide, didecanoyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxydiethylacetate, t-butyl peroxydiethylisobutyrate, t-butyl peroxy-3,5,5-trimethylhexanoate, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butyl peroxyacetate, cumyl peroxyneodecanoate, t-amyl peroxyneodecanoate, t-amyl peroxyvalerate, t-butyl peroxyneodecanoate, t-butyl peroxymaleate, t-butyl peroxyvalerate, t-butyl peroxyisononanoate, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl peroxybenzoate, methyl isobutyl ketone hydroperoxide, 3,6,9-triethyl-3,6,9-trimethyltricyclo[6.3.1.0]dodecane triperoxide and 2,2-di(t-butylperoxy)butane.

[0067] According to a preferred embodiment of the present application, the peroxide is selected from at least one of t-butyl peroxyneopentanoate, t-butyl peroxy-2-ethylhexyl ester, t-butyl peroxybenzoate, di-t-butyl peroxide, t-butyl peroxybenzoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyvalerate and dicaprylyl peroxydicarbonate.

[0068] In the present application, the solvent is a conventional selection in the art as long as the object of the present application can be achieved. According to a particularly preferred embodiment of the present application, the solvent is at least one of alkane and / or alkene having 4 to 18 carbon atoms, preferably alkane and / or alkene having 6 to 15 carbon atoms, and more preferably alkane and / or alkene having 9 to 12 carbon atoms. By employing the foregoing preferences, the utilization efficiency of the polymerization material can be further improved.

[0069] According to a particularly preferred embodiment of the present application, the telomerization agent is selected from at least one of aldehyde, alcohol, alkane and alkene, and preferably at least one of acetaldehyde, propyl aldehyde, propanol, 1-butanol, propylene, 1-butene, isobutylene, 1-hexene, propane, butane, pentane and hexane.

[0070] According to a preferred embodiment of the present application, the present application provides a device as shown in Figure 1 The device comprises: a first compressor 2, a second compressor 3, a preheater 4, and a plurality of tubular reactors connected in series, including a first tubular reactor 5, a second tubular reactor 6a, and a third tubular reactor 6b, wherein the preheater 4 is used to heat the polymerization raw materials to 140-200℃. A high-pressure pressure relief valve 7, a cooler 8, and a high-pressure separator 9 are sequentially arranged on the material outlet pipeline of the third tubular reactor 6b, so that the material flowing out of the reactor is subjected to pressure reduction, cooling, and pre-separation at one time. The material at the top outlet of the high-pressure separator 9 returns to the inlet of the second compressor 3 through a high-loop circuit 10. The material at the bottom outlet of the high-pressure separator 9 is subjected to secondary separation in a low-pressure separator 11, so as to obtain the polymer for granulation. The material at the top outlet of the low-pressure separator 11 is sent to a low-loop circuit 12, and then is pressurized by a circulating material compressor 1 and sent to the first compressor 2.

[0071] According to a preferred embodiment of the present application, the present application provides an initiator feeder as shown in Figure 2

[0072] Figure 2 (a) The feeder of a preferred embodiment of the present application comprises a first feeder shell 21a and a first feeder cavity 22a defined by the first feeder shell 21a, and the first feeder shell 21a is provided with a first feeder inlet 20a and a first feeder outlet 23a.

[0073] Figure 2 (b) The feeder of a preferred embodiment of the present application comprises a second feeder shell 21b and a second feeder cavity 22b defined by the second feeder shell 21b, and the second feeder shell 21b is provided with a second feeder inlet 20b and two side outlets, i.e., a second feeder outlet 23b1 and a third feeder outlet 23b2.

[0074] According to a preferred embodiment of the present application, the present application provides a polymerization reactor 31 as shown in Figure 3

[0075] The feeder 36 is located at the contraction structure or the inlet of the contraction structure of the polymerization reactor, and the central axis of the material flowing direction of the outlet of the feeder forms an angle with the material flowing direction of the central axis of the polymerization reactor.

[0076] ​​In order to make the present application more easily understood, the present application will be described in detail below in conjunction with examples, which are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. The specific conditions not indicated in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturers. The raw materials involved in the examples are commercially available unless otherwise specified.

[0077] In the following examples:

[0078] The initiator unit consumption = the amount of initiator used / the yield of polyethylene;

[0079] The reactor temperature peak fluctuation range = the maximum value of the reactor temperature peak - the average value of the reactor temperature peak;

[0080] The reactor temperature valley fluctuation range = the maximum value of the reactor temperature valley - the average value of the reactor temperature valley.

[0081] Wherein the reactor temperature peak refers to the maximum value on the reactor temperature curve, and the reactor temperature valley refers to the minimum value on the reactor temperature curve.

[0082] Example 1

[0083] In Figure 1 In the polymerization reaction process shown in the figure, a mixture of t-butyl peroxypivalate, t-butylperoxy-2-ethylhexylate, t-butylperoxy benzoate, di-t-butyl peroxide, n-hexane and isododecane with a total content of 80wt% and a ratio of n-hexane to isododecane of 1:4 is used as the injection material discharged from the feeding unit, which is injected into the flow channel of the polymerization monomer stream in the polymerization reactor through the feeders arranged in parallel with the central axis of the flow channel of the polymerization monomer stream in the polymerization reactor and intersecting at the intersection point in the contraction structure. The mass ratio of t-butyl peroxypivalate, t-butylperoxy-2-ethylhexylate, t-butylperoxy benzoate and di-t-butyl peroxide is 3:2:2:1. The injection material is sequentially sent into the feed pump, the feeder, and then from the opening on the side of the feeder into the flow channel of the polymerization monomer stream in the polymerization reactor to mix with the polymerization monomer (ethylene), and the molecular weight regulator used is propylene, wherein the mass ratio of the polymerization monomer to the regulator is 1:0.006.

[0084] Wherein, the inlet of the flow channel of the polymerization monomer stream in the polymerization reactor, i.e. Figure 1 The pressure between 4 and 5 in the figure is 250MPa, the pipe diameter of the contraction structure at the inlet is 45mm, and the material flow rate at the inlet of the contraction structure is 42t / h. The length ratio of the contraction structure and the throat structure of the flow channel of the polymerization monomer stream in the polymerization reactor is 2:1, the length ratio of the contraction structure and the expansion structure is 1:1, and the length to inner diameter ratio of the throat structure is 4:1; the contraction angle of the contraction structure is 30°, and the expansion angle of the expansion structure is 30°.

[0085] The flow velocity of the material stream at the inlet of the flow channel of the polymerization monomer stream in the polymerization reactor is 15 m / s, the minimum flow velocity is 15 m / s, and the ratio of the maximum flow velocity to the minimum flow velocity is 4:1; the outlet flow velocity of the opening on the side of the feeder is 15 m / s, and the opening on the side of the feeder is such that the angle between the direction of the material outlet of the feeder and the fluid flow direction of the central axis of the flow channel of the polymerization monomer stream in the polymerization reactor is 180°, i.e. completely counter-current impact.

[0086] The amount of initiator and the conversion rate of ethylene are shown in Table 1.

[0087] Example 2

[0088] The same as Example 1, except that:

[0089] The outlet flow velocity of the opening on the side of the feeder is 10 m / s.

[0090] The results are shown in Table 1.

[0091] Example 3

[0092] The same as Example 1, except that:

[0093] The outlet flow velocity of the opening on the side of the feeder is 10 m / s.

[0094] The solvent in the material to be injected discharged by the feeding unit is isododecane, and the total content of isododecane is 80 wt%.

[0095] Example 4

[0096] The same as Example 1, except that:

[0097] The outlet flow velocity of the opening on the side of the feeder is 10 m / s.

[0098] The opening on the side of the feeder is such that the angle between the direction of the material outlet of the feeder and the fluid flow direction of the central vertical axis of the flow channel of the polymerization monomer stream in the polymerization reactor is 90°.

[0099] Example 5

[0100] The same as Example 1, except that:

[0101] The outlet flow velocity of the opening on the side of the feeder is 10 m / s.

[0102] The opening on the side of the feeder is such that the angle between the direction of the material outlet of the feeder and the fluid flow direction of the central vertical axis of the flow channel of the polymerization monomer stream in the polymerization reactor is 90°.

[0103] The solvent in the material to be injected discharged by the feeding unit is isododecane, and the content of the solvent is 70 wt%.

[0104] Comparative Example 1

[0105] The same as Example 1, except that:

[0106] The flow channel of the polymerization monomer stream in the polymerization reactor has no throat structure. The opening on the side of the feeder discharges at a flow rate of 10 m / s. The opening on the side of the feeder is such that the direction of discharge of the feeder is the same as the fluid flow direction of the central vertical axis of the flow channel of the polymerization monomer stream in the polymerization reactor.

[0107] Comparative Example 2

[0108] The same as Example 1, except that:

[0109] The flow channel of the polymerization monomer stream in the polymerization reactor has no throat structure; the opening on the side of the feeder discharges at a flow rate of 10 m / s. The feeder has a hole at the end of the feed pipe channel of the initiator and solvent mixture, and has no side hole. The angle between the direction of discharge of the feeder and the fluid flow direction of the central vertical axis of the flow channel of the polymerization monomer stream in the polymerization reactor is 90°.

[0110] Comparative Example 3

[0111] The same as Example 1, except that:

[0112] The flow channel of the polymerization monomer stream in the polymerization reactor has no contraction structure, throat structure and expansion structure. The opening on the side of the feeder discharges at a flow rate of 10 m / s. The opening on the side of the feeder is such that the direction of discharge of the feeder is the same as the fluid flow direction of the central vertical axis of the flow channel of the polymerization monomer stream in the polymerization reactor.

[0113] Table 1

[0114]

[0115] Compared with the comparative examples, in the preferred embodiments of the present application, the rapid mixing and dispersion of the initiator and the polymerization monomer by the polymerization material avoids excessive local initiator concentration, reduces the quenching of the initiator due to the shielding effect, lowers the unit consumption of the initiator, and reduces the fluctuation range of the reactor temperature peak and the reactor temperature valley, thereby inhibiting the generation of temperature hot spots and improving the safety of the device.

[0116] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. However, these simple modifications and combinations should also be regarded as disclosed content of the present application, and all belong to the protection scope of the present application.

Claims

1. A polymerization process characterized by, The method is performed in a polymerization device, The polymerization device comprises a polymerization reactor, which comprises a polymer monomer stream feeding port at an end and a feeder of a stream containing an initiator and a solvent arranged through a wall of the polymerization reactor, the feeder being partially closed at an end inside the polymerization reactor and having an opening arranged at a side; The opening is such that an angle between a discharging direction of the feeder and a central axis of a flow channel of the polymer monomer stream in the polymerization reactor is ≥ 150°; The polymerization reactor comprises, in sequence along a material flow direction, a converging structure, a throat structure and a diverging structure; A central axis of the feeder intersects a central axis of the flow channel of the polymer monomer stream in the polymerization reactor, and an intersection point is located in the converging structure; The method comprises: feeding the stream containing the initiator and the solvent from the feeder into the flow channel of the polymer monomer stream in the polymerization reactor to react with the polymer monomer fed from the polymer monomer feeding port at an end of the polymerization reactor; A discharging flow rate of the opening at a side of the feeder is 5-30 m / s, and a minimum flow rate of material in the flow channel of the polymer monomer stream in the polymerization reactor is 5-20 m / s.

2. The method according to claim 1, wherein a length ratio of the converging structure and the throat structure is 0.1-10:1, and a length ratio of the converging structure and the diverging structure is 0.2-5:1; and / or a converging angle of the converging structure is 10°-70°; and / or a diverging angle of the diverging structure is 10°-40°; and / or a ratio of a length to an inner diameter of the throat structure is 0.01:1-20:

1.

3. The method of claim 1, wherein, The ratio of the length to the inner diameter of the throat structure is 0.5:1-10:

1.

4. The method of claim 1, wherein, The number of the feeders is 1-5.

5. The method of claim 4, wherein, When the feeders are multiple, each feeder is arranged in parallel or staggered in the converging structure.

6. The method of claim 1, wherein, The polymerization device comprises multiple polymerization reactors connected in series.

7. The method of claim 1, wherein, The polymerization device comprises 2-5 polymerization reactors connected in series.

8. The method of claim 1, wherein, The polymerization device further comprises a polymer material feeding unit and a feeding pump for providing the stream containing the initiator and the solvent and injecting into the feeder.

9. The method of claim 1, wherein, The feeder comprises a shell and a feeding cavity defined by the shell, the shell is provided with a material inlet communicating with the feeding cavity and at least one opening arranged at a side; The polymerization reactor is a tubular reactor.

10. The method of claim 9, wherein, The shell is provided with 1-5 openings arranged at a side and communicating with the feeding cavity.

11. The method according to claim 1, wherein The discharging flow rate of the opening at a side of the feeder is 10-15 m / s; and / or The minimum flow rate of material in the flow channel of the polymer monomer stream in the polymerization reactor is 8-16 m / s.

12. The method of claim 1, wherein, A ratio of a maximum flow rate to a minimum flow rate of material in the flow channel of the polymer monomer stream in the polymerization reactor is 4:1-9:

1.

13. The method according to claim 1, wherein A mass ratio of the initiator to the solvent in the stream containing the initiator and the solvent is 5:95-40:60; and / or The polymer monomer is selected from olefins with a carbon atom number of 2-16; and / or The polymerization device further comprises a polymer material feeding unit and a feeding pump for providing the stream containing the initiator and the solvent and injecting into the feeder. The polymerization monomer stream contains polymerization monomers and telogenic agent, wherein the mass ratio of the telogenic agent and the polymerization monomers is 0-0.

05.

14. The method according to claim 13, wherein, the mass ratio of the initiator and the solvent in the initiator and solvent containing stream is 15:85-30:70; and / or The polymerization monomers are selected from alkenes with carbon atom number of 2-8.

15. The method according to claim 13 or 14, wherein, The initiator is an organic peroxide with temperature of half-life per hour of 56-150℃; and / or The solvent is at least one of alkanes and / or alkenes with carbon atom number of 4-18; and / or The telogenic agent is selected from at least one of aldehydes, alcohols, alkanes, alkenes.

16. The method according to claim 15, wherein, The organic peroxide is selected from at least one of t-butyl peroxy pivalate, t-butyl peroxy-2-ethylhexyl, t-butyl peroxybenzoate, di-t-butyl peroxide and dicumyl peroxide; and / or The solvent is at least one of alkanes and / or alkenes with carbon atom number of 6-15; and / or The telogenic agent is selected from at least one of acetaldehyde, propionaldehyde, propanol, 1-butanol, propylene, 1-butene, isobutylene, 1-hexene, propane, butane, pentane, hexane.

17. The method of claim 15, wherein, The solvent is at least one of alkanes and / or alkenes with carbon atom number of 9-12.

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