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Method for inhibiting formation of polyethylene wax in ethylene oligomerization

A polyethylene wax and ethylene oligomerization technology, which is applied in chemical instruments and methods, hydrocarbon purification/separation, bulk chemical production, etc., can solve the problems of increasing separation cost, accumulation, etc. easy-to-achieve effects

Inactive Publication Date: 2019-01-25
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method often requires a larger amount of phenolic inhibitor (the molar ratio of the contained phenolic hydroxyl group to the aluminum in the cocatalyst ≥ 0.7) to achieve a better polyethylene wax inhibitory effect, which will lead to inhibitors in the Buildup in the final product, increasing separation costs

Method used

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  • Method for inhibiting formation of polyethylene wax in ethylene oligomerization
  • Method for inhibiting formation of polyethylene wax in ethylene oligomerization
  • Method for inhibiting formation of polyethylene wax in ethylene oligomerization

Examples

Experimental program
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Effect test

Embodiment 1

[0047] Under nitrogen protection, the pyridine bis-imine ligand L{2,6-bis-[(2-methylanilinoethyl)pyridine]} shown in formula a is molar ratio 1 with ferrous chloride: After compounding of 1, a catalyst represented by formula a' is obtained. dubbed 4×10 -6 mol / mL of the main catalyst toluene suspension. The cocatalyst methylaluminoxane (MAO) is a 10 wt% toluene solution, and the concentration of the substance is about 1.5 mol / L. The polyethylene wax inhibitor is aniline.

[0048] Catalyst LFeCl 2 The structural formula:

[0049]

[0050] Heat the 250ml oligomerization reactor to above 90°C, vacuum bake for 2 hours, and replace it with high-purity nitrogen several times during this period. Subsequently, the temperature of the reactor was adjusted to a reaction temperature of 50° C. by circulating jacketed cooling water, and 50 mL of toluene was added as a reaction medium. Set the concentration of the iron-based catalyst in the reaction medium to be 4×10 -5 mol / L, add a c...

Embodiment 2

[0053] with [-NH 2 ]:[Al]=0.5 molar ratio adds a certain amount of polyethylene wax inhibitor aniline, and other operations are with embodiment 1. After gas-liquid-solid separation of the reaction product, the polyethylene wax was dried and weighed to obtain 0.02 g; the liquid-phase α-olefin product was analyzed by chromatography to obtain 3.85 g; the content of polyethylene wax in the total product was 0.5 wt%.

Embodiment 3

[0055] with [-NH 2 ]:[Al]=0.7 molar ratio adds a certain amount of polyethylene wax inhibitor aniline, and other operations are with embodiment 1. After the gas-liquid-solid separation of the reaction product, there is no polyethylene wax; the liquid-phase α-olefin product is 3.56 g after chromatographic analysis; the content of polyethylene wax in the total product is 0.

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Abstract

The invention discloses a method for inhibiting formation of polyethylene wax in ethylene oligomerization. The method includecomprises the steps of premixing a cocatalyst with a main catalyst and a polyethylene wax inhibitor or separately adding the three into an oligomerization reactor containing a reaction medium, controlling a suitable reaction temperature, introducing ethylene monomers until the reaction pressure is reached, and performing ethylene oligomerization to prepare high-linearity alpha-olefin, wherein the polyethylene wax inhibitor is selected from one or more of first-class aromatic amine compounds (Ar-NH2). The method has the advantages that the yield of the liquid-phase alpha-olefin can be increased while formation of the polyethylene wax is effectively inhibited, so thatthe content of the polyethylene wax in ethylene oligomerization products is remarkably reduced, safe and stable device operation is benefited, and high economic benefit is achieved.

Description

technical field [0001] The invention relates to the field of ethylene oligomerization to prepare high-grade linear α-olefins, in particular to a method for inhibiting the formation of by-product polyethylene wax in the ethylene oligomerization reaction process. Background technique [0002] Linear alpha-olefins refer to C with double bonds at the ends of the molecule 4 And above linear olefins are a kind of important petrochemical raw materials with huge demand. Among them, C 4 ~C 24 The linear α-olefins have a wide range of applications in the preparation of low-density polyethylene, high-density polyethylene, high-grade detergents, high-grade alcohols, high-grade PAO lubricating oils, surfactants and oil additives. Currently, ethylene oligomerization is the main method for producing linear α-olefins, especially C 4 ~C 24 The most dominant and promising method for linear α-olefins. [0003] In 1998, Brookhart and Gibson's research groups independently reported iron an...

Claims

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Application Information

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IPC IPC(8): C07C11/02C07C7/20C07C2/30
CPCC07C2/30C07C7/20C07C2531/22C07C11/02Y02P20/52
Inventor 叶健蒋斌波阳永荣王靖岱孙婧元黄正梁廖祖维杨遥
Owner ZHEJIANG UNIV