CN-121975041-A - Preparation method and preparation system of olefin polymer

CN121975041ACN 121975041 ACN121975041 ACN 121975041ACN-121975041-A

Abstract

The invention relates to the technical field of olefin polymerization, in particular to a preparation method and a preparation system of an olefin polymer. According to the preparation method, the reaction raw materials are added into a serial sectional reaction system for polymerization reaction, part of reaction liquid in each section of reaction zone is controlled for cyclic reaction, the cyclic ratio and the reaction path length of each section of reaction zone are controlled on the basis of continuous reaction, the temperature difference of different reaction zones is controlled, the raw material composition, the temperature distribution and the reaction degree of each section of reaction zone can be regulated and controlled, the structure of a product is effectively controlled, the use of a solvent is reduced, the solid content of the product is improved, and the energy consumption caused by the solvent is reduced. Therefore, the high-efficiency production and the structural control of the olefin polymer can be realized without differentially controlling the raw materials of each section of reaction zone, and the method has the advantages of simple process and low energy consumption, and is suitable for large-scale industrial production.

Inventors

YANG YING
WANG JINQIANG
HU ZHAN
ZHANG YANYU
QIAO XIAOFEI
WANG XUQING
BAO GUOFENG
ZENG XIONGWEI

Assignees

万华化学集团股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A process for the preparation of an olefin polymer comprising the steps of: Adding reaction raw materials into a series-connected segmented reaction system, and sequentially carrying out polymerization reaction in each segment of reaction zone, wherein the series-connected segmented reaction system comprises n segments of reaction zones, wherein n is an integer greater than or equal to 2; For each section of reaction zone, part of the reaction liquid is circulated to the section of reaction zone to realize the circulation reaction, and the rest of reaction liquid enters the next section of reaction zone to carry out the polymerization reaction; the total reaction path length of the series-connected segmented reaction system is recorded as L, and the reaction path length of each segment of reaction zone is respectively and independently 0.1L-0.9L; the mass ratio of the reaction liquid recycled to the reaction zone to the fresh feed liquid added to the reaction zone is recorded as a recycle ratio, and the recycle ratio of each section of reaction zone is 5-100 independently; the difference of polymerization temperatures of different reaction areas is 0-80 ℃; The reaction raw materials comprise olefin monomers, a main catalyst, a cocatalyst and a solvent.
2. The process for producing an olefin polymer according to claim 1, wherein the multistage static tube reactor is used as the multistage reaction system, wherein the multistage static tube reactor comprises n reactor units connected in series, wherein the reactor units comprise a tube array comprising the reaction zone, wherein the tube array is provided with a tube array side feed port and a tube array side discharge port, and wherein the tube array side feed port and the tube array side discharge port are communicated by a circulating device to realize circulation of the reaction liquid.
3. The process for the preparation of an olefin polymer according to claim 2, wherein the multistage static tubular reactor satisfies one or more of the following characteristics: (1) The outlet side of the multistage static tube array reactor is provided with a back pressure control device; (2) For each section of reactor unit, a turbulent flow element is arranged in the tube array, wherein the turbulent flow element comprises at least one of a spiral sheet, a twisted sheet, an inner fin, a corrugated sheet and a porous plate; (3) For each section of reactor unit, the reactor unit is provided with a shell side material inlet, a shell side material outlet and a distribution structure, wherein the distribution structure is arranged on the shell side material inlet and/or the shell side material outlet; (4) The circulating device comprises at least one of an axial flow stirring paddle and a circulating pump.
4. A process for the preparation of an olefin polymer as claimed in any one of claims 1 to 3 wherein the process meets one or more of the following characteristics: (1) n is an integer of 2 to 5; (2) The circulation ratio of each section of reaction zone is 10-80 independently; (3) The difference of the polymerization temperatures of different reaction areas is 20-60 ℃; (4) The molecular weight of the olefin polymer is in a multimodal distribution; (5) L is 0.5 to 50m.
5. A process for the preparation of an olefin polymer as claimed in any one of claims 1 to 3 wherein the process meets one or more of the following characteristics: (1) From the first reaction zone to the last reaction zone, the polymerization temperature of the preceding reaction zone is greater than or equal to the polymerization temperature of the following reaction zone, or the polymerization temperature of the preceding reaction zone is less than or equal to the polymerization temperature of the following reaction zone; (2) The polymerization temperature of each reaction zone is 110-200 ℃ independently; (3) The polymerization pressure of each reaction zone is 2-10 MPa; (4) For each reaction zone, temperature control is performed by adding a heat transfer medium.
6. A process for the preparation of an olefin polymer as claimed in any one of claims 1 to 3 wherein the reaction feed meets one or more of the following characteristics: (1) The olefin monomers include ethylene and alpha-olefins; (2) The main catalyst comprises at least one of a metallocene catalyst and a non-metallocene catalyst; (3) The cocatalyst comprises at least one of aluminoxane, an alkyl aluminum compound, alkyl aluminum chloride and an organoboride; (4) The solvent comprises a hydrocarbon solvent of C4-C15; (5) The reaction raw materials also comprise a chain transfer agent.
7. The method of producing an olefin polymer according to claim 6, wherein the olefin monomer satisfies one or more of the following characteristics: (1) The carbon number of the alpha-olefin is 3-20; (2) The alpha-olefin comprises at least one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-eicosene; (3) The mass ratio of the ethylene to the alpha-olefin is (0.1-5) 1.
8. The process for producing an olefin polymer as defined in claim 6, wherein the main catalyst comprises dimethylsilylene (N-t-butylamino) (tetramethylcyclopentadienyl) titanium dichloride, dimethylsilylene (N-t-butylamino) (fluorenyl) titanium dichloride, (pentamethylcyclopentadienyl) trimethoxytitanium, diphenylmethylene (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, dimethylsilylene bis (2-methyl-4-phenyl-1-indenyl) zirconium dichloride, racemic dimethylsilylbis (1-indenyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (1, 3-dimethylcyclopentadienyl) zirconium dichloride, (cyclopentadienyl) (1, 2-dimethoxyethane) zirconium trichloride, diphenylsilyl (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, racemic dimethylsilylbis (2-methyl-1-indenyl) zirconium dichloride, diphenylmethylenecyclopentadienyl (2, 7-di-t-butylfluorenyl) bis (2-methyl-1-indenyl) zirconium dichloride, racemic dimethylcyclopentadienyl (2-dimethylfluorenyl) zirconium dichloride, p-dimethylcyclopentadienyl (2-dimethylfluorenyl) zirconium dichloride, at least one of bis (n-butylcyclopentadiene) hafnium dichloride and compounds represented by formula I-1 to formula I-7: Wherein M is independently selected from Ti, zr or Hf, and R is independently selected from one of C1-C30 alkyl and C6-C30 aryl.
9. The process for preparing an olefin polymer according to claim 6, wherein the cocatalyst satisfies one or more of the following characteristics: (1) The aluminoxane comprises at least one of methylaluminoxane and modified methylaluminoxane; (2) The alkyl aluminum compound includes at least one of triethylaluminum, triisobutylaluminum, and trioctylaluminum; (3) The alkyl aluminum chloride comprises at least one of ethyl aluminum monochloride, ethyl aluminum sesquichloride and ethyl aluminum dichloride; (4) The organoboride includes at least one of trityl tetrakis (pentafluorophenyl) borate, tris (pentafluorophenyl) boron, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and dioctadecyl methyl tertiary amine tetrakis (pentafluorophenyl) borate.
10. A preparation system of olefin polymer, which is characterized by comprising a feeding device, a reaction device and a control device; The feeding device is used for conveying reaction raw materials to the reaction device; The reaction device is provided with a segmented reaction system and n circulating devices which are connected in series, wherein the segmented reaction system comprises n segments of reaction areas for carrying out polymerization reaction, n is an integer which is more than or equal to 2, the total reaction path length of the segmented reaction system which is connected in series is recorded as L, the reaction path length of each segment of reaction area is respectively and independently 0.1L-0.9L, each segment of reaction area is connected with 1 circulating device and is used for circulating part of reaction liquid to the corresponding segment of reaction area to realize the circulating reaction, and the rest of reaction liquid enters the next segment of reaction area for carrying out polymerization reaction; The control device is connected with the feeding device and the reaction device to control the actions of the devices, the control device is used for controlling the circulation ratio of each section of reaction zone to be 5-100, the difference between the polymerization temperatures of different reaction zones to be 0-80 ℃, and the circulation ratio is the mass ratio of the reaction liquid circulated to the reaction zone to the fresh feed liquid added into the reaction zone of the section.

Description

Preparation method and preparation system of olefin polymer Technical Field The invention relates to the technical field of olefin polymerization, in particular to a preparation method and a preparation system of an olefin polymer. Background Olefin polymers include unimodal olefin polymers and multimodal olefin polymers, depending on the molecular weight peak shape. The multimodal olefin polymer is formed by the synergy of a plurality of components with low molecular weight to high molecular weight, has wider molecular weight distribution, ensures that the material has excellent fluidity and lower melt viscosity, is beneficial to improving the processing performance, and ensures that the material has higher melt strength by the high molecular weight component, thereby improving the mechanical properties such as tensile strength, tearing strength, puncture resistance and the like. The multimodal olefin polymer is capable of achieving a balance of processability and mechanical strength compared to the unimodal olefin polymer, and can meet different application requirements. Multimodal olefin polymers are often produced by a series reactor process, i.e. polymers having different molecular weights or structures are produced in different reactors using different polymerization conditions. However, in the conventional series reactor process, the raw material composition of each reactor needs to be finely adjusted, such as dehydrogenation, diversion and other treatments on upstream reaction products, and different types of raw materials are respectively introduced into different reactors, so that the overall process flow is complex, the regulation difficulty is high, and the yield is limited. In addition, the solution method has become a core preparation route of the high-end olefin polymer due to flexible molecular design and good product uniformity. However, the process requires a large amount of solvent, the solid content of the product is low, and the subsequent separation and recovery of the solvent consumes a great amount of energy, so that the overall energy consumption is obviously higher than that of the polymerization processes such as a gas phase method, a slurry method and the like. Therefore, the traditional serial reactor method based on the solution method cannot meet the requirements of structural control and efficient production of the olefin polymer, and limits the large-scale production of the olefin polymer. In view of the above, there is a need for a solution process-based olefin polymer production process that is low in energy consumption, high in yield, simple in process and easy to control. Disclosure of Invention Based on the above, the main purpose of the invention is to provide a preparation method of olefin polymer, which can realize high-efficiency production and structure control of olefin polymer, has simple process and low energy consumption, and can meet the industrial production requirement. In a first aspect, the present invention provides a process for the preparation of an olefin polymer comprising the steps of: Adding reaction raw materials into a series-connected segmented reaction system, and sequentially carrying out polymerization reaction in each segment of reaction zone, wherein the series-connected segmented reaction system comprises n segments of reaction zones, wherein n is an integer greater than or equal to 2; For each section of reaction zone, part of the reaction liquid is circulated to the section of reaction zone to realize the circulation reaction, and the rest of reaction liquid enters the next section of reaction zone to carry out the polymerization reaction; the total reaction path length of the series-connected segmented reaction system is recorded as L, and the reaction path length of each segment of reaction zone is respectively and independently 0.1L-0.9L; the mass ratio of the reaction liquid recycled to the reaction zone to the fresh feed liquid added to the reaction zone is recorded as a recycle ratio, and the recycle ratio of each section of reaction zone is 5-100 independently; the difference of polymerization temperatures of different reaction areas is 0-80 ℃; The reaction raw materials comprise olefin monomers, a main catalyst, a cocatalyst and a solvent. In some embodiments, the series-connected segmented reaction system adopts a multistage static tube array reactor, the multistage static tube array reactor comprises n reactor units which are connected in series, each reactor unit is provided with a tube array, each tube array comprises a reaction zone, each tube array is provided with a tube array side feed inlet and a tube array side discharge outlet, and the tube array side feed inlets and the tube array side discharge outlets are communicated through a circulating device so as to realize circulation of reaction liquid. In some embodiments, the multistage static tubular reactor satisfies one or more of the following characteristics: (1) The o