CN111875727B - Reinforced reaction system and method for preparing polypropylene by solution method - Google Patents
Reinforced reaction system and method for preparing polypropylene by solution method Download PDFInfo
- Publication number
- CN111875727B CN111875727B CN202010554278.9A CN202010554278A CN111875727B CN 111875727 B CN111875727 B CN 111875727B CN 202010554278 A CN202010554278 A CN 202010554278A CN 111875727 B CN111875727 B CN 111875727B
- Authority
- CN
- China
- Prior art keywords
- micro
- outlet
- polypropylene
- interface generator
- prepolymerization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000004743 Polypropylene Substances 0.000 title claims abstract description 96
- 229920001155 polypropylene Polymers 0.000 title claims abstract description 96
- -1 polypropylene Polymers 0.000 title claims abstract description 90
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 52
- 238000000034 method Methods 0.000 title claims abstract description 36
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 48
- 239000002904 solvent Substances 0.000 claims abstract description 28
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000007791 liquid phase Substances 0.000 claims abstract description 23
- 239000012535 impurity Substances 0.000 claims abstract description 21
- 239000000203 mixture Substances 0.000 claims abstract description 15
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 14
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 55
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 55
- 239000007789 gas Substances 0.000 claims description 48
- 239000012071 phase Substances 0.000 claims description 39
- 238000005406 washing Methods 0.000 claims description 37
- 239000000047 product Substances 0.000 claims description 35
- 239000000843 powder Substances 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 22
- 239000003054 catalyst Substances 0.000 claims description 16
- 238000010025 steaming Methods 0.000 claims description 15
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 239000003595 mist Substances 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 7
- 238000001704 evaporation Methods 0.000 claims description 6
- 229920000642 polymer Polymers 0.000 claims description 6
- 239000002954 polymerization reaction product Substances 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 4
- 239000001257 hydrogen Substances 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 230000009471 action Effects 0.000 claims description 3
- 238000011084 recovery Methods 0.000 claims description 2
- 239000012808 vapor phase Substances 0.000 claims 1
- 238000003860 storage Methods 0.000 description 18
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 14
- 238000004064 recycling Methods 0.000 description 11
- 238000012546 transfer Methods 0.000 description 9
- 239000001294 propane Substances 0.000 description 7
- 238000009835 boiling Methods 0.000 description 6
- 238000004807 desolvation Methods 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 239000012046 mixed solvent Substances 0.000 description 5
- 238000010992 reflux Methods 0.000 description 5
- 238000005265 energy consumption Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 230000001804 emulsifying effect Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000007613 slurry method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000005501 phase interface Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F110/04—Monomers containing three or four carbon atoms
- C08F110/06—Propene
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The invention provides a reinforced reaction system and a reinforced reaction method for preparing polypropylene by a solution method. Comprising the following steps: the polymerization reactor comprises a prepolymerization reactor and a polymerization reactor which are connected in sequence, wherein the prepolymerization reactor is provided with a prepolymerization micro-interface generator, and the polymerization reactor is provided with a micro-interface generator set; the invention also comprises a desolventizing tower, wherein the desolventizing tower is used for removing solvent and impurities from a polypropylene product, a polypropylene inlet is arranged in the middle of the desolventizing tower and is connected with an outlet at the bottom of the flash tank, and a nitrogen micro-interface generator for dispersing and crushing high-temperature nitrogen into micro-bubbles is arranged in the desolventizing tower; on the other hand, the gas-liquid phase mixture is more uniform, the uniformity of the obtained polypropylene is higher, and the product quality is improved.
Description
Technical Field
The invention relates to the technical field of polypropylene preparation, in particular to a reinforced reaction system and a reinforced reaction method for preparing polypropylene by a solution method.
Background
Polypropylene is an industrial raw material of plastic products with wide application, and the quality of polypropylene directly influences the quality of plastic products and the application range. The current situation of the polypropylene industry in China is as follows: various small-scale production devices are more, and devices with large production capacity are fewer; the devices for producing the general materials are more, and the devices for producing the special materials are less. Wherein the large-scale polypropylene production device is mainly based on the introduction technology, and the medium-scale and small-scale polypropylene production devices are mainly based on the autonomous development technology. From the production Process of Polypropylene (PP) in China, the production process can be classified into a solution method, a slurry method (also called a solvent method), a bulk method, a bulk and gas phase combination method and a gas phase method according to the polymerization type. At present, the solution method is mainly used for producing special-grade PP woven bags with lower modulus and higher toughness compared with the slurry method PP woven bags. The solution method generally adopts a stirred bed reactor, a kettle type reactor, a tubular reactor, a tower type reactor and the like as a polymerization reactor, however, the phase interface area and the mass transfer coefficient provided by the reactor are limited, the gas utilization rate is low, so that the reaction efficiency is low, the reaction performance is difficult to obtain breakthrough improvement, and the overall efficiency of the reaction is influenced; in addition, the uniformity of the obtained polypropylene is not high due to uneven mixing between gas and liquid phases and uneven distribution of molecular weight, and the quality of the product is affected.
In view of this, the present invention has been made.
Disclosure of Invention
The first object of the present invention is to provide a reinforced reaction system for preparing polypropylene by solution method, wherein the reinforced reaction system increases the mass transfer area between gas phase and liquid phase materials, improves the reaction efficiency and reduces the energy consumption by arranging a micro-interface generator on a prepolymerization reactor and arranging a micro-interface generator set on a polymerization reactor; on the other hand, the gas-liquid phase mixture is more uniform, the uniformity of the obtained polypropylene is higher, and the product quality is improved.
The second aim of the invention is to provide a reaction method for preparing polypropylene by adopting the solution method of the reinforced reaction system, and the polypropylene obtained by the reaction has good product quality and high yield.
In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:
the invention provides a reaction system for preparing polypropylene by a solution method, which comprises the following steps: the device comprises a prepolymerization reactor and a polymerization reactor which are connected in sequence, wherein the prepolymerization reactor is provided with a prepolymerization micro-interface generator for dispersing crushed materials into micro-bubbles, and the polymerization reactor is provided with a micro-interface generator set for dispersing the crushed materials into micro-bubbles;
the bottom of the polymer reactor is provided with a polymerization reaction product outlet which is connected with a flash tank for flashing a product after polymerization reaction; the bottom of the flash tank is provided with a flash tank bottom outlet for discharging polypropylene products; the bottom outlet of the flash tank is connected with a desolventizing tower for removing solvent and impurities from polypropylene products, a nitrogen micro-interface generator for dispersing and crushing high-temperature nitrogen into micro-bubbles is arranged in the desolventizing tower, a product outlet is arranged on the side wall of the desolventizing tower, and the product outlet is connected with the steaming tank for decomposing a catalyst in the polymer.
In the prior art, the reaction system for preparing polypropylene by a solution method has the following problems: on one hand, the gas-liquid phase mass transfer area of the polymerization reactor is limited, and in the reaction process, the reaction mixed raw materials and the gas cannot be fully mixed, so that the energy consumption is high and the reaction efficiency is low; on the other hand, the uniformity of the obtained polypropylene is not high due to uneven mixing between gas and liquid phases and uneven molecular weight distribution, and the quality of the product is affected.
In order to solve the technical problems, the micro-interface generator is arranged on the prepolymerization reactor, and meanwhile, after the micro-interface generator set is arranged on the polymerization reactor, the mass transfer area between gas-phase and liquid-phase materials is increased, the reaction efficiency is improved, and the energy consumption is reduced; on the other hand, the gas-liquid phase mixture is more uniform, the uniformity of the obtained polypropylene is higher, and the product quality is improved.
Further, the device also comprises a propylene conveying pipeline, wherein the prepolymerization micro-interface generator is arranged in the prepolymerization reactor, and the propylene conveying pipeline penetrates through the wall surface of the prepolymerization reactor to be connected with the prepolymerization micro-interface generator so as to introduce propylene into the prepolymerization micro-interface generator. Propylene enters the interior of the prepolymerization micro-interface generator, and is dispersed and crushed into micro-bubbles through the crushing and dispersing action of the prepolymerization micro-interface generator, so that the thickness of a liquid film is reduced, the mass transfer area between the propylene and liquid-phase materials is effectively increased, the mass transfer resistance is reduced, and the reaction efficiency is improved.
Further, the micro-interface generator set comprises a first micro-interface generator and a second micro-interface generator, wherein the first micro-interface generator is arranged outside the polymerization reactor, the second micro-interface generator is arranged inside the polymerization reactor, and the first micro-interface generator is introduced into the prepolymer obtained by the reaction of the polymerization reactor.
Further, a prepolymer outlet is formed in the bottom of the prepolymerization reactor, a feed inlet is formed in the side wall of the polymerization reactor, one end of the first micro-interface generator is connected with the feed inlet, and the other end of the first micro-interface generator is connected with the prepolymer outlet.
Further, the second micro-interface generator is connected with a gas phase pipeline for recovering gas above the liquid level of the polymerization reactor and a liquid phase circulating pipeline for providing power for the second micro-interface generator, one end of the liquid phase circulating pipeline is connected with the side wall of the polymerization reactor, and the other end of the liquid phase circulating pipeline is connected with the second micro-interface generator. During the reaction, a large amount of unreacted propylene is accumulated above the reactor, and enters the bottom for repeated cyclic reaction again through a gas phase pipeline for full recovery, so that the mass transfer efficiency is improved.
Those skilled in the art will appreciate that the micro-interface generator used in the present invention is embodied in the present inventors' prior patents, such as the patent applications CN201610641119.6, 201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U and CN 207581700U. The specific product structure and working principle of the micro bubble generator (i.e. the micro interface generator) are described in detail in the prior patent CN201610641119.6, and the application document describes that the micro bubble generator comprises a body and a secondary crushing member, the body is provided with a cavity, an inlet communicated with the cavity is arranged on the body, the opposite first end and the second end of the cavity are both open, wherein the cross-sectional area of the cavity is reduced from the middle part of the cavity to the first end and the second end of the cavity; the secondary crushing member is arranged at least one of the first end and the second end of the cavity, a part of the secondary crushing member is arranged in the cavity, and an annular channel is formed between the secondary crushing member and the through holes with two open ends of the cavity. The micro bubble generator also comprises an air inlet pipe and a liquid inlet pipe. The specific working principle of the structure disclosed in the application document is known as follows: the liquid enters the micro bubble generator tangentially through the liquid inlet pipe, and the gas is rotated and cut at ultrahigh speed to break the gas bubbles into micro bubbles in micron level, so that the mass transfer area between the liquid phase and the gas phase is increased, and the micro bubble generator in the patent belongs to a pneumatic micro interface generator.
In addition, in the prior patent 201610641251.7, it is described that the primary bubble breaker has a circulating liquid inlet, a circulating gas inlet and a gas-liquid mixture outlet, and the secondary bubble breaker communicates the feed inlet with the gas-liquid mixture outlet, which means that the bubble breaker needs to be mixed with gas and liquid, and in addition, as seen in the following figures, the primary bubble breaker mainly uses the circulating liquid as power, so that the primary bubble breaker belongs to a hydraulic micro-interface generator, and the secondary bubble breaker simultaneously introduces the gas-liquid mixture into an elliptical rotating ball for rotation, thereby realizing bubble breaking during rotation, so that the secondary bubble breaker actually belongs to a gas-liquid linkage micro-interface generator. In fact, both the hydraulic type micro-interface generator and the gas-liquid linkage type micro-interface generator belong to a specific form of the micro-interface generator, however, the micro-interface generator adopted by the invention is not limited to the above-mentioned forms, and the specific structure of the bubble breaker described in the prior patent is only one form which can be adopted by the micro-interface generator of the invention.
Furthermore, the prior patent 201710766435.0 states that the principle of the bubble breaker is that the high-speed jet flows are used for achieving the mutual collision of gases, and also states that the bubble breaker can be used for a micro-interface strengthening reactor, and the correlation between the bubble breaker and the micro-interface generator is verified; in addition, in the prior patent CN106187660, there are also related descriptions about specific structures of bubble breakers, specifically, see paragraphs [0031] to [0041] in the specification, and the accompanying drawings, which describe the specific working principle of the bubble breaker S-2 in detail, wherein the top of the bubble breaker is a liquid phase inlet, the side is a gas phase inlet, and the entrainment power is provided by the liquid phase entering from the top, so as to achieve the effect of breaking into ultrafine bubbles.
Since the micro-interface generator was just developed in the early stage of the prior patent application, the micro-interface generator is named as a micro-bubble generator (CN 201610641119.6), a bubble breaker (201710766435.0) and the like in the early stage, and with the continuous technological improvement, the micro-interface generator is named as a micro-interface generator in the later stage, and the micro-interface generator is equivalent to the prior micro-bubble generator, the bubble breaker and the like in the present invention, but the names are different.
In summary, the micro-interface generator of the present invention belongs to the prior art, while some bubble breakers belong to the pneumatic bubble breaker type, some bubble breakers belong to the hydraulic bubble breaker type, and some bubble breakers belong to the gas-liquid linkage type bubble breaker type, but the differences between the types are mainly selected according to different specific working conditions, and in addition, the connection between the micro-interface generator and the reactor, as well as other devices, including the connection structure and the connection position, are determined according to the structure of the micro-interface generator, which is not limited.
Further, a first steam outlet is arranged at the top of the steaming tank, and gas coming out of the first steam outlet enters the polypropylene washing tower to be used for recycling a small amount of polypropylene powder entrained in steam.
Further, the side wall of the prepolymerization reactor is provided with a mixed solvent inlet, and the mixed solvent inlet is connected with a premixing tank, and the premixing tank is used for premixing materials, catalysts and solvents. The reaction mass, the catalyst and the solvent can be uniformly mixed by premixing, and the reaction center of the catalyst can be activated. The automatic stirring mechanism is arranged inside the premixing tank, and the mixture is more uniformly mixed by further stirring.
Further, a low boiling point solvent outlet is arranged at the top of the desolventizing tower, and the low boiling point solvent outlet is sequentially connected with a first condenser and a first condensate storage tank; the bottom of the first condensate storage tank is provided with a reflux liquid outlet, and the reflux liquid outlet is connected with the top of the desolventizing tower so as to be used for top reflux. Preferably, the first condenser is a tube condenser, and compared with other condensers, the tube condenser has simple and compact structure and low manufacturing cost.
Further, a condensate outlet is further arranged at the bottom of the first condensate storage tank, and the condensate outlet is connected with the bottom of the premixing tank so as to be used for recycling the condensed solvent. The solvent separated from the desolventizing tower returns to the premixing tank for repeated use, thereby saving material consumption.
Further, a gas phase outlet is arranged at the top of the flash tank, and materials coming out of the gas phase outlet are introduced into a pre-washing tower for washing and impurity removal.
Further, a gas-phase propylene outlet is formed in the top of the pre-washing tower, the gas-phase propylene outlet is sequentially connected with a second condenser and a second condensate storage tank, and the second condensate storage tank is connected with the pre-mixing tank for recycling propylene. The gas-phase propylene from the top of the washing tower is cooled by a condenser and then enters a condensate storage tank, and a collecting line is arranged at one side of the bottom of the condenser storage tank, so that the gas-phase propylene contains a certain amount of propane, and the propane is an inert component which does not participate in the reaction, and the propane is repeatedly recovered and accumulated, so that the propane amount is increased, and the rest propylene is cooled and then returned to the premixing tank for recycling, thereby saving resources.
Further, a polypropylene solution outlet is formed in the side wall of the pre-washing tower, and the polypropylene solution outlet is communicated with the bottom outlet of the flash tank.
Further, a polypropylene inlet is arranged in the middle of the desolventizing tower and is simultaneously connected with the bottom outlet of the flash tank and the polypropylene solution outlet.
Further, a polypropylene powder outlet is arranged at the bottom of the pre-washing tower, and the polypropylene powder outlet is connected with a bag filter for separating polypropylene powder. The bag filter is provided with a back blowing system, the upper part of the bag filter is provided with a filter bag, the filter bag can enable gas to pass through to block powder, and as a large amount of powder is attached to the filter bag, the pressure difference between the front and the back of the filter bag is increased to damage the filter bag, so that the filter effect is lost, and the back blowing system is required to be arranged.
Further, the top of the bag filter is provided with a second steam outlet which is connected with the bottom of the low pressure propylene scrubber for recovering propylene in gas phase.
Further, a third steam outlet is arranged at the top of the low-pressure propylene washing tower, and the steam outlet is connected with a mist separator for removing impurities in the recovered gas-phase propylene.
Further, the bottom of the mist separator is connected with the bottom of the low-pressure propylene washing tower, and is used for returning heavy components separated in the mist separator back to the low-pressure propylene washing tower for washing.
Further, propylene gas from the top of the mist separator is returned to the prepolymerization micro-interface generator for recycling.
Further, the top of the flash tank is provided with a dynamic separator for separating polypropylene powder from the gas phase material as much as possible. Because the gas coming out of the top of the flash tank needs to be recycled and the powder is carried as little as possible or not, the power separator is arranged at the outlet of the top of the flash tank, so that most of the powder can be left in the flash tank, and the separation efficiency of the flash tank is improved.
Furthermore, a pressure reducing valve is arranged on a pipeline of the polymerization reaction product outlet connected with the flash tank, the pressure reducing valve is preferably a film type pressure reducing valve, and compared with other pressure reducing valves, the film of the film type pressure reducing valve is more sensitive to pressure change, and the accuracy is higher than +/-1%.
In addition, the invention also provides a method for preparing polypropylene by adopting the solution method of the reinforced reaction system, which comprises the following steps:
propylene is dispersed and crushed into micro bubbles, and then prepolymerization reaction is carried out under the action of a catalyst to obtain prepolymer;
the prepolymerization and propylene and hydrogen which are dispersed and crushed into micro bubbles are polymerized to obtain a product;
flash evaporating, washing and removing impurities, removing solvent and impurities and steaming the product;
preferably, the polymerization reaction is carried out at a temperature of 161-166 ℃ and a pressure of 2.7-3.4MPa.
Further, the preparation method of the polypropylene specifically comprises the following steps: firstly, premixing materials, a catalyst and a solvent in a premixing tank, then introducing the materials, the catalyst and the solvent into a prepolymerization reactor, simultaneously introducing propylene gas into a prepolymerization micro-interface generator, dispersing and crushing the propylene gas into small droplets, fully emulsifying the dispersed and crushed propylene and the premix, and then performing prepolymerization reaction to obtain a prepolymer; introducing prepolymer into a first micro-interface generator, fully emulsifying the prepolymer and propylene and hydrogen which are simultaneously introduced, then introducing the mixture into a polymerization reactor to perform polymerization reaction, introducing a polymerization product into a flash tank to perform flash evaporation, introducing polypropylene viscous liquid which is discharged from the bottom of the flash tank into a desolventizing tower to perform solvent and impurity removal, introducing gas phase at the top of the flash tank into a pre-washing tower to perform washing and impurity removal, condensing gas-phase propylene which is discharged from the top of the pre-washing tower, then returning the gas-phase propylene to the pre-mixing tank for recycling, introducing a polypropylene solution which is discharged from the side wall of the pre-washing tower and the viscous liquid which is discharged from the bottom of the flash tank into the desolventizing tower to perform solvent and impurity removal, introducing polypropylene powder at the bottom of the pre-washing tower into a bag filter to perform filtration to obtain polypropylene powder, and introducing polypropylene which is discharged from the side wall of the pre-washing tower and the polypropylene powder into the steaming tank to perform steaming.
The polypropylene product prepared by the reaction method has good quality and high yield.
Compared with the prior art, the invention has the beneficial effects that: according to the reinforced reaction system for preparing polypropylene by the solution method, the micro-interface generator is arranged on the prepolymerization reactor, and meanwhile, after the micro-interface generator set is arranged on the polymerization reactor, the mass transfer area between gas-phase and liquid-phase materials is increased, the reaction efficiency is improved, and the energy consumption is reduced; on the other hand, the gas-liquid phase mixture is more uniform, the uniformity of the obtained polypropylene is higher, and the product quality is improved.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:
fig. 1 is a schematic structural diagram of a reaction system for preparing polypropylene by a solution method according to an embodiment of the present invention.
Description of the drawings:
10-a prepolymerization reactor; 101-a pre-polymerization micro-interface generator;
1010-prepolymer outlet; 1020—mixed solvent inlet;
a 20-polymerization reactor; 201-a first micro-interface generator;
202-a second micro-interface generator; 2010-a feed port;
2020-polymerization reaction product outlet; 30-a premix tank;
40-flash tank; 401-a pressure relief valve;
402-a heater; 403-power separator;
4010-gas phase outlet; 4020—flash tank bottom outlet;
50-a pre-wash column; 501-a second condenser;
502-a second condenser storage tank; 5010—a gas phase propylene outlet;
5020-polypropylene powder outlet; 5030-polypropylene solution outlet;
5040-a proper amount of extraction outlet;
60-bag filter; 6010-mixture outlet;
6020-second steam outlet; 70-desolventizing tower;
701-nitrogen micro-interface generator; 702-a first condenser;
703-a first condensate storage tank; 7010-polypropylene inlet;
7020-air inlet; 7030-product outlet;
7040-low boiling point solvent outlet; 7050-condensate outlet;
80-low pressure propylene scrubber; 801-mist separator;
8010-third steam outlet; 90-steaming pot;
9010-a first steam outlet; 100-polypropylene washing tower.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and detailed description, but it will be understood by those skilled in the art that the examples described below are some, but not all, examples of the present invention, and are intended to be illustrative of the present invention only and should not be construed as limiting the scope of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In order to more clearly illustrate the technical scheme of the invention, the following description is given by way of specific examples.
Examples
Referring to fig. 1, a reaction system for preparing polypropylene by a solution method according to an embodiment of the present invention includes a prepolymerization reactor 10 and a polymerization reactor 20, wherein a prepolymerization micro-interface generator 101 for dispersing a crushed material into droplets is disposed inside the prepolymerization reactor 10, and a propylene conveying pipe is disposed through a wall surface of the prepolymerization reactor 10 and connected to the prepolymerization micro-interface generator 101, so as to introduce propylene into the prepolymerization micro-interface generator; the polymerization reactor 20 is provided with a micro-interface generator set for dispersing the crushed materials into small droplets.
It should be emphasized that the micro-interface generator set includes a first micro-interface generator 201 and a second micro-interface generator 202, where the first micro-interface generator 201 is disposed outside the polymerization reactor 20, the second micro-interface generator 202 is disposed inside the polymerization reactor 20, and the first micro-interface generator 201 is introduced into the prepolymer obtained by the reaction in the polymerization reactor 20.
Specifically, the bottom of the prepolymerization reactor 10 is provided with a prepolymer outlet 1010, the sidewall of the polymerization reactor 20 is provided with a feed inlet 2010, and one end of the first micro-interface generator 201 is connected to the feed inlet 2010, and the other end is connected to the prepolymer outlet 1010. The second micro-interface generator 202 is connected with a gas phase pipeline for recovering gas above the liquid level of the polymerization reactor 20 and a liquid phase circulation pipeline for improving the power of the second micro-interface generator 202, one end of the liquid phase circulation pipeline is connected with the side wall of the polymerization reactor 20, and the other end of the liquid phase circulation pipeline is connected with the second micro-interface generator 202.
In this embodiment, a mixed solvent inlet 1020 is disposed on a side wall of the prepolymerization reactor 10, the mixed solvent inlet 1020 is connected to a premixing tank 30, and the premixing tank 30 is used for premixing materials, catalyst and solvent. The reaction mass, the catalyst and the solvent can be uniformly mixed by premixing, and the reaction center of the catalyst can be activated. The premixing tank 30 is internally provided with an automatic stirring mechanism, and the mixture is more uniformly mixed by further stirring.
Further, a polymerization product outlet 2020 is arranged at the bottom of the polymer reactor 20, and the polymerization product outlet 2020 is connected with the flash tank 40 for flashing a product after polymerization; the pressure reducing valve 401 and the heater 402 are sequentially arranged on the pipeline between the polymerization reaction product outlet 2020 and the flash tank 40, and heating is performed before flash evaporation, so that the flash evaporation efficiency can be improved. The pressure reducing valve 401 is preferably a film type pressure reducing valve. Compared with other pressure reducing valves, the diaphragm of the film type pressure reducing valve is more sensitive to pressure, and the accuracy is higher than +/-1%.
In particular, the top of the flash tank 40 is provided with a dynamic separator 403 for separating polypropylene powder from the gas phase material as much as possible. Since the gas treated from the top of the flash tank 40 is recycled with as little or no powder as possible, the provision of the power separator 403 at the top outlet of the flash tank 40 allows a substantial portion of the powder to remain in the flash tank 40, improving the separation efficiency of the flash tank 40.
Further, a bottom outlet 4020 of the flash tank for discharging polypropylene product is further disposed at the bottom of the flash tank 40, a gas phase outlet 4010 is disposed at the top of the flash tank 40, and the material coming out from the gas phase outlet 4010 is introduced into the pre-washing tower 50 for washing and impurity removal. Specifically, a gas-phase propylene outlet 5010 is disposed at the top of the pre-washing tower 50, and the gas-phase propylene outlet 5010 is sequentially connected to a second condenser 501 and a second condensate storage tank 502, and the second condensate storage tank 502 is connected to the pre-mixing tank 30 for recycling propylene. The gas-phase propylene from the top of the pre-washing tower 50 enters the second condensate storage tank 502 after being cooled by the second condenser 501, and a collecting line is arranged at one side of the bottom of the second condenser storage tank 502, so that the gas-phase propylene contains a certain amount of propane, which is an inert component not participating in the reaction, and the propane is repeatedly recovered and accumulated, so that the propane amount is increasingly larger, and the rest propylene is continuously removed, cooled and returned to the premixing tank 30 for recycling, thereby saving resources. The bottom of the second condenser storage tank 502 is provided with a proper amount of extraction outlet 5040, the side wall of the pre-washing tower 50 is provided with a polypropylene solution outlet 5030, the bottom of the pre-washing tower 50 is provided with polypropylene powder 5020, and the polypropylene powder outlet 5020 is connected with a bag filter 60 for separating polypropylene powder.
Specifically, the bottom of the bag filter 60 is provided with a mixture outlet 6010, the top is provided with a second steam outlet 6020, the second steam outlet 6020 is connected with the bottom of the low-pressure propylene scrubber 80 for recovering the gas-phase propylene, the top of the low-pressure propylene scrubber 80 is provided with a third steam outlet 8010, and the steam outlet 8010 is connected with a mist separator 801 for removing impurities in the recovered gas-phase propylene. Propylene gas coming out of the top of the mist separator 801 is returned to the prepolymerization micro-interface generator 101 for recycling.
In this embodiment, the apparatus further includes a desolvation tower 70, the desolvation tower 70 is used for removing solvent and impurities from a polypropylene product, a polypropylene inlet 7010 is disposed in the middle of the desolvation tower 70, the polypropylene inlet 7010 is simultaneously connected with a flash tank bottom outlet 4020 and a polypropylene solution outlet 5030, the flash tank bottom outlet 4020 and the polypropylene solution outlet 5030 are communicated for merging two-way pipeline materials and then enter the desolvation tower 70 for removing solvent and impurities, a nitrogen micro-interface generator 701 for dispersing and crushing high-temperature nitrogen into microbubbles is disposed in the desolvation tower 70, an air inlet 7020 is disposed on a side wall of the desolvation tower 70, and the air inlet 7020 is connected with the nitrogen micro-interface generator 701 through a pipeline and is used for conveying the high-temperature nitrogen into the nitrogen micro-interface generator 701.
Further, a low boiling point solvent outlet 7040 is arranged at the top of the desolventizing tower 70, and the low boiling point solvent outlet 7040 is sequentially connected with a first condenser 702 and a first condensate storage tank 703; the bottom of the first condensate storage tank 703 is provided with a reflux outlet connected to the top of the desolventizing tower 70 for overhead reflux. The bottom of the first condensate storage tank 703 is further provided with a condensate outlet 7050, and the condensate outlet 7050 is connected to the bottom of the pre-mixing tank 30 for recycling the condensed solvent. The top of the first condensate storage tank 703 is also provided with a nitrogen outlet for recovering nitrogen. The bottom of the desolventizing tower is also provided with a residue outlet for discharging a small amount of high boiling point solvent and catalyst.
In this embodiment, a product outlet 7030 is disposed on a side wall of the desolventizing tower 70 for producing polypropylene after dehydration and impurity removal, and the product outlet 7030 and a mixture outlet 6010 are both connected to a steaming tank 90 for separating catalyst in the polymer, specifically, a first steam outlet 9010 is further disposed at the top of the steaming tank 90, and gas coming out of the first steam outlet 9010 enters the polypropylene washing tower 100 for recovering a small amount of polypropylene powder entrained in the steam.
The operation and principle of the reaction system for preparing polypropylene by the solution process of the present invention will be briefly described.
Firstly, premixing materials, a catalyst and a solvent in a premixing tank 30, introducing the materials, the catalyst and the solvent into a prepolymerization reactor 10, introducing propylene gas into a prepolymerization micro-interface generator 101, dispersing and crushing the propylene gas into small liquid drops, fully emulsifying the dispersed and crushed propylene and the premix, and performing prepolymerization reaction to obtain a prepolymer; the prepolymer is introduced into a first micro-interface generator 201, fully emulsified with propylene and hydrogen which are simultaneously introduced, then enters the polymerization reactor 20 for polymerization reaction, the polymerization product then enters a flash tank 40 for flash evaporation, gas phase at the top of the flash tank 40 enters a pre-washing tower 50 for washing and impurity removal, gas phase propylene at the top of the pre-washing tower 50 is condensed and returned to a premixing tank 30 for recycling, the polypropylene solution extracted from the side wall of the pre-washing tower 50 and viscous liquid extracted from the bottom of the flash tank 40 are collected and then enter a desolventizing tower 70 for removing solvent and impurities, polypropylene powder at the bottom of the pre-washing tower 50 enters a bag filter 60 for filtering to obtain polypropylene powder, and meanwhile, polypropylene extracted from the side wall of the desolventizing tower 70 and the polypropylene powder are collected and then enter a steaming tank 90 for steaming.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (10)
1. An enhanced reaction system for preparing polypropylene by a solution process, comprising: the device comprises a prepolymerization reactor and a polymerization reactor which are connected in sequence, wherein the prepolymerization reactor is provided with a prepolymerization micro-interface generator for dispersing crushed materials into micro-bubbles, and the polymerization reactor is provided with a micro-interface generator set for dispersing the crushed materials into micro-bubbles;
the bottom of the polymer reactor is provided with a polymerization reaction product outlet which is connected with a flash tank for flashing a product after polymerization reaction; the bottom of the flash tank is provided with a flash tank bottom outlet for discharging polypropylene products; the bottom outlet of the flash tank is connected with a desolventizing tower for removing solvent and impurities from a polypropylene product, a nitrogen micro-interface generator for dispersing and crushing high-temperature nitrogen into micro-bubbles is arranged in the desolventizing tower, a product outlet is arranged on the side wall of the desolventizing tower, and the product outlet is connected with the steaming tank for decomposing a catalyst in a polymer;
the propylene conveying pipeline penetrates through the wall surface of the prepolymerization reactor to be connected with the prepolymerization micro-interface generator, so that propylene is introduced into the prepolymerization micro-interface generator;
the micro-interface generator set comprises a first micro-interface generator and a second micro-interface generator, the first micro-interface generator is arranged outside the polymerization reactor, the second micro-interface generator is arranged inside the polymerization reactor, and the first micro-interface generator is introduced into prepolymer obtained by the reaction of the polymerization reactor;
the bottom of the prepolymerization reactor is provided with a prepolymer outlet, the side wall of the polymerization reactor is provided with a feed inlet, one end of the first micro-interface generator is connected with the feed inlet, and the other end of the first micro-interface generator is connected with the prepolymer outlet;
the second micro-interface generator is connected with a gas phase pipeline for recovering gas above the liquid level of the polymerization reactor and a liquid phase circulating pipeline for providing power for the second micro-interface generator, one end of the liquid phase circulating pipeline is connected with the side wall of the polymerization reactor, and the other end of the liquid phase circulating pipeline is connected with the second micro-interface generator.
2. The enhanced reaction system for preparing polypropylene by solution process according to claim 1, wherein the top of the steaming tank is further provided with a first steam outlet, and the gas coming out of the first steam outlet enters a polypropylene washing tower for recovering a small amount of polypropylene powder entrained in the steam.
3. The enhanced reaction system for preparing polypropylene by solution process according to claim 1, wherein the top of the flash tank is provided with a gas phase outlet, and the material coming out of the gas phase outlet is introduced into a pre-washing tower for washing and impurity removal.
4. A solution process for preparing polypropylene enhancement reaction system according to claim 3, wherein the bottom of the pre-wash tower is provided with a polypropylene powder outlet connected to a bag filter for separating polypropylene powder.
5. The solution-process polypropylene-producing intensive reaction system according to claim 4, wherein a mixture outlet is provided at the bottom of the bag filter, the mixture outlet being connected to the steaming tank for filtered polypropylene powder to enter the steaming tank.
6. The enhanced reaction system for preparing polypropylene by solution process according to claim 3, wherein the side wall of the pre-washing tower is provided with a polypropylene solution outlet, and the polypropylene solution outlet is communicated with the bottom outlet of the flash tank.
7. The reaction enhancement system for preparing polypropylene by solution process according to claim 6, wherein a polypropylene inlet is provided in the middle of the desolventizing tower, and is connected to both the bottom outlet of the flash tank and the polypropylene solution outlet.
8. The enhanced reaction system for the solution process production of polypropylene according to claim 4, wherein the top of the bag filter is provided with a second vapor outlet connected to the bottom of the low pressure propylene scrubber for the recovery of propylene in the vapor phase.
9. The enhanced reaction system for producing polypropylene according to claim 8, wherein a third vapor outlet is provided at the top of the low pressure propylene washing tower, and a mist separator is connected to the third vapor outlet for removing impurities from the recovered gas phase propylene.
10. A method for preparing polypropylene by using the solution method of the reinforced reaction system as claimed in any one of claims 1 to 9, comprising the steps of:
propylene is dispersed and crushed into micro bubbles, and then prepolymerization reaction is carried out under the action of a catalyst to obtain prepolymer;
the prepolymerization and propylene and hydrogen which are dispersed and crushed into micro bubbles are polymerized to obtain a product;
flash evaporating, washing and removing impurities, removing solvent and impurities and steaming the product;
preferably, the polymerization reaction is carried out at a temperature of 161-166 ℃ and a pressure of 2.7-3.4MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010554278.9A CN111875727B (en) | 2020-06-17 | 2020-06-17 | Reinforced reaction system and method for preparing polypropylene by solution method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010554278.9A CN111875727B (en) | 2020-06-17 | 2020-06-17 | Reinforced reaction system and method for preparing polypropylene by solution method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111875727A CN111875727A (en) | 2020-11-03 |
| CN111875727B true CN111875727B (en) | 2023-09-19 |
Family
ID=73156759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010554278.9A Active CN111875727B (en) | 2020-06-17 | 2020-06-17 | Reinforced reaction system and method for preparing polypropylene by solution method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111875727B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101613426A (en) * | 2009-08-06 | 2009-12-30 | 浙江绍兴三圆石化有限公司 | Polyacrylic production method and device thereof |
| CN210045215U (en) * | 2019-01-29 | 2020-02-11 | 南京延长反应技术研究院有限公司 | Low-pressure gas-liquid reinforced emulsion bed reaction device |
-
2020
- 2020-06-17 CN CN202010554278.9A patent/CN111875727B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101613426A (en) * | 2009-08-06 | 2009-12-30 | 浙江绍兴三圆石化有限公司 | Polyacrylic production method and device thereof |
| CN210045215U (en) * | 2019-01-29 | 2020-02-11 | 南京延长反应技术研究院有限公司 | Low-pressure gas-liquid reinforced emulsion bed reaction device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111875727A (en) | 2020-11-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111875724B (en) | Micro-interface enhanced reaction system and method for preparing polyethylene by solution method | |
| WO2022036839A1 (en) | External micro-interface strengthening system and method for preparing butyl octanol by carbonylation of propylene | |
| WO2019090883A1 (en) | Method for preparing polypropylene or propylene-ethylene copolymer | |
| CN111892673A (en) | Micro-interface enhanced reaction system and method for preparing polypropylene | |
| CN112010746A (en) | External micro-interface strengthening system and method for preparing acetic acid through methanol carbonylation | |
| CN108997081A (en) | A kind of reaction and rectification device and method of cyclohexene hydration cyclohexanol | |
| CN111892671A (en) | Micro-interface enhanced reaction system and method for preparing polypropylene | |
| CN111875727B (en) | Reinforced reaction system and method for preparing polypropylene by solution method | |
| CN108779194B (en) | Process for extracting polyolefins | |
| CN111574399A (en) | Reaction system and method for ammoximation and recovery of tert-butyl alcohol | |
| EP1170284B1 (en) | Urea synthesis process and apparatus | |
| CN219784700U (en) | Battery grade lithium carbonate apparatus for producing | |
| CN111892675A (en) | Reinforced reaction system and method for preparing polypropylene | |
| CN111808221A (en) | Reaction system and method for preparing polypropylene by solution method | |
| CN111892672A (en) | Reinforced reaction system and method for preparing polypropylene by slurry method | |
| CN111892674A (en) | Micro-interface enhanced reaction system and method for preparing polypropylene by solution method | |
| RU2808489C1 (en) | System for carrying out reaction for producing polyethylene with increasing microsurfaces using polymerization in solution | |
| CN111925465A (en) | Intelligent reaction system and method for preparing polypropylene by solution method | |
| CN112023833A (en) | Micro-interface strengthening system and method for preparing N-methyl sodium taurate | |
| CN108102011A (en) | A kind of aftertreatment technology and device of high polymer chlorination reaction | |
| CN111875725A (en) | Micro-interface enhanced reaction system and method for preparing polyethylene by slurry method | |
| WO2021208201A1 (en) | External micro-interface ammoximation reaction system and method | |
| CN112010786A (en) | Reaction system and method for preparing N-methyl sodium taurate | |
| CN206940777U (en) | A kind of production equipment of ton polyphenylene oxide | |
| CN218516657U (en) | Novel washing equipment for cyclodextrin polymer modification production process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: No. 88, Tanqu South Road, Jiangbei New District, Nanjing City, Jiangsu Province Patentee after: Nanjing Anlige Co.,Ltd. Country or region after: China Address before: No. 88, Tanqu South Road, Jiangbei New District, Nanjing City, Jiangsu Province Patentee before: Nanjing Yanchang Reaction Technology Research Institute Co.,Ltd. Country or region before: China |
|
| CP03 | Change of name, title or address |