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Olefin polymerization inhibitor and its prepn process

A polymerization inhibitor, olefin technology, applied in chemical instruments and methods, purification/separation of hydrocarbons, hydrocarbons, etc., can solve the problems of tray and reboiler scaling, etc.

Inactive Publication Date: 2005-12-14
SHANDONG NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the process of separating butadiene by dimethylformamide method, it is necessary to maintain a relatively high temperature, because butadiene itself has a high reactivity, and the concentration of diolefins in the column is relatively high, coupled with the existence of system impurities Therefore, during extractive distillation, butadiene is often polymerized due to heat, oxygen, ferrous ions, and metal surface active centers, resulting in fouling of trays and reboilers
[0004] Since the newly generated AO is relatively stable and will not initiate polymerization, it acts as a polymerization inhibitor, but the above reaction is reversible, and the relatively stable AO will still react with hydrocarbons RH to generate new free radicals R , leading to the reoccurrence of the polymerization reaction

Method used

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  • Olefin polymerization inhibitor and its prepn process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] a. Preparation of Nitroxide Radicals

[0032] Heat the mixture of 2,2,6,6-tetramethyl-4-alkoxypiperidine: disodium ethylenediaminetetraacetic acid: sodium carbonate: water = 100: 0.35: 0.2: 200 to 50°C, Adding the concentration of 3 times the weight of the mixed solution is 50% hydrogen peroxide, and it is incubated for 5 hours to generate 4-alkoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical; then

[0033] b. add ethylenediamine;

[0034] c. Add dimethylformamide and water, and mix to obtain the product.

[0035] d. In parts by weight, take dimethylformamide 5, diamine or alkylamine or alkanolamine compound 15, 4-alkoxy-2,2,6,6-tetramethylpiperidine nitrogen oxide Free radical 5 and water 50 are mixed evenly to obtain the product.

Embodiment 2

[0037] a. Preparation of Nitroxide Radicals

[0038] Heat the mixture of 2,2,6,6-tetramethyl-4-alkoxypiperidine: disodium ethylenediaminetetraacetic acid: sodium carbonate: water = 100:0.5:0.3:100 to 95°C, Then add 30% hydrogen peroxide of 8 times the weight of the mixed solution, and keep warm for 3 hours to generate 4-alkoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical; then

[0039] b. add propylene diamine;

[0040] c. Add dimethylformamide and water, and mix to obtain the product.

[0041] d. In parts by weight, take dimethylformamide 30, diamine or alkylamine or alkanolamine compound 10, 4-alkoxy-2,2,6,6, tetramethylpiperidine nitrogen oxide Free radical 10 and water 70 are mixed evenly to obtain the product.

Embodiment 3

[0043] a. Preparation of Nitroxide Radicals

[0044] Heat the mixture of 2,2,6,6-tetramethyl-4-alkoxypiperidine: disodium ethylenediaminetetraacetic acid: sodium carbonate: water = 100:1:0.5:350 to 70°C, Then add 40% hydrogen peroxide of 0.5 times the weight of the mixed solution, and keep warm for 10 hours to generate 4-alkoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical; then

[0045] b. add butanediamine;

[0046] c. Add dimethylformamide and water, and mix to obtain the product.

[0047] d. In parts by weight, take dimethylformamide 10, diamine or alkylamine or alkanolamine compound 3,4-alkoxy-2,2,6,6-tetramethylpiperidine nitrogen oxide Free radicals 1, hydration 60 evenly to get the product.

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Abstract

The present invention provides one kind of olefin polymerization inhibitor. The olefin polymerization inhibitor consists of dimethyl formamide 5-30 weight portions, amines 1-15 weight portions, 4-alkoxyl-2, 2, 6, 6-tetramethyl piperidyl nitroxide free radical 1-30 weight portions and water 30-90 weight portions. The preparation process includes A. preparing 4-alkoxyl-2, 2, 6, 6-tetramethyl piperidyl nitroxide free radical through mixing 2, 2, 6, 6-tetramethyl-4-alkoxyl piperidine, disodium editate, sodium carbonate and water in certain proportion, heating the mixture to 50-95 deg.c, adding 30-50 % concentration hydrogen peroxide solution and maintaining for 1-10 hr; B. adding diamine, alkyl amine or alkanolamine; and C. adding dimethyl formamide and water through mixing to obtain the product.

Description

technical field [0001] The invention relates to fine chemical industry and its organic synthesis, more specifically to a polymerization inhibitor for preventing olefin polymerization and a preparation method thereof. Background technique [0002] In the process of separating butadiene by dimethylformamide method, it is necessary to maintain a relatively high temperature, because butadiene itself has a high reactivity, and the concentration of diolefins in the column is relatively high, coupled with the existence of system impurities Therefore, during extractive distillation, butadiene often polymerizes due to heat, oxygen, ferrous ions, and metal surface active centers, resulting in fouling of trays and reboilers. Not only will it cause the consumption of butadiene as a material, but if the polymer is deposited on the heat exchanger, it will affect the heat transfer and reduce the performance of the equipment. If it is deposited in the tower, it will affect the separation of...

Claims

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Application Information

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IPC IPC(8): C07C7/20
Inventor 刘文阁邱新建吴志广孙惠章
Owner SHANDONG NORMAL UNIV
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