Method for quickly starting polymerization reaction in alpha-olefin gas-phase fluidized bed reactor

A gas-phase fluidized bed and polymerization reaction technology, which is applied in the field of rapid start-up of α-olefin gas-phase fluidized bed reactor polymerization reaction, can solve the problem of unseen α-olefin rapid start-up method, unfavorable energy saving and consumption reduction, slow polymerization reaction, etc. problems, to achieve the effect of saving energy, reducing consumption, improving product market competitiveness, and avoiding production accidents

Inactive Publication Date: 2012-07-11
CHINA PETROLEUM & CHEM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method takes a long time to dehydrate, slows down the establishment of a continuous and stable polymerization reaction, and consumes a large amount of raw material ethylene, which is not conducive to energy saving and consumption reduction.
In the prior art, there are no bibliographical reports on the rapid start-up method for the continuous polymerization of α-olefin gas phase fluidized bed reactor

Method used

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  • Method for quickly starting polymerization reaction in alpha-olefin gas-phase fluidized bed reactor
  • Method for quickly starting polymerization reaction in alpha-olefin gas-phase fluidized bed reactor
  • Method for quickly starting polymerization reaction in alpha-olefin gas-phase fluidized bed reactor

Examples

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Effect test

Embodiment 1

[0066] Example 1 Production of high-density polyethylene by using α-olefin gas-phase fluidized-bed reactor polymerization quick start method

[0067] After using nitrogen and ethylene to replace the trace amount of water in the gas-phase fluidized bed reactor, the metallocene catalyst is first used to initiate the polymerization reaction, and then switch to the conventional chromium-based catalyst polymerization reaction system, and stop adding the metallocene catalyst at the same time. into a conventional ethylene gas phase fluidized bed reactor for polymerization. Production of high-density polyethylene. Including the following steps:

[0068] ① replacement

[0069] a. Nitrogen replacement: after bed installation, control the nitrogen pressure to 0.7MPa~1.1MPa, and raise the temperature of the system to 85°C~88°C; according to the replacement method of the prior art, replace until the water content of the system is ≤5ppm;

[0070] b. Ethylene replacement: After nitrogen r...

Embodiment 2

[0085] During the development and production of chromium-based catalyst products in the full-density pilot plant of Qilu Plastic Factory, if the S-2 chromium-based catalyst does not react for 2 hours and the ash content exceeds 0.06%, it is very dangerous, and the bed has to be replaced in serious cases. Because the discharge port of the pilot plant is designed to be 50mm, if the replacement does not cut the bottom, the reaction will be established by catalyst accumulation and detoxification. Once the catalyst reacts, it is easy to agglomerate, and the agglomeration is difficult to be brought out by the discharge, resulting in the reaction not going on. You can only park and change beds.

[0086] Start the polymerization reaction according to the method and steps of Example 1, save about 1 ton of ethylene every time you start up, and save about 16 hours of start-up time.

Embodiment 3

[0088] When the HDPE unit of Qilu Plastic Factory was started up, there was also the situation that the S-2 chromium catalyst did not react for a long time. The normal response was 4 hours, and the response was 10 hours long. The ethylene emission was 4-5t / h, so the material consumption was also very high.

[0089] Start the polymerization reaction according to the method and steps of Example 1, save about 50 tons of ethylene every time you start up, and save about 10 hours of start-up time.

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Abstract

The invention relates to a method for quickly starting polymerization reaction in an alpha-olefin gas-phase fluidized bed reactor, belongs to a method for preparing alpha-olefin homopolymer or copolymer, and in particular relates to a method for preparing corresponding polymer by ethylene polymerization or copolymerization of ethylene and other alpha-olefins. The method is characterized by comprising the following steps of: displacing trace water in the gas-phase fluidized bed reactor by using nitrogen and ethylene, initiating to start alpha-olefin polymerization reaction or alpha-olefin copolymerization reaction by using a metallocene catalyst, switching to the conventional chromium catalyst alpha-olefin polymerization or alpha-olefin copolymerization reaction system, stopping adding the metallocene catalyst, and switching to the conventional alpha-olefin gas-phase fluidized bed reactor for polymerization reaction. By the method for quickly starting continuous polymerization reaction in the alpha-olefin gas-phase fluidized bed reactor, the trace water is quickly removed, time for establishing continuous and stable polymerization reaction is short, and the consumption of the ethylene for displacement is low; and production accidents are avoided, the consumption of the ethylene is reduced, and the production period is shortened.

Description

technical field [0001] The invention relates to a method for quickly starting the polymerization reaction of an α-olefin gas-phase fluidized bed reactor. It belongs to the preparation method of α-olefin homopolymer or copolymer. In particular, it relates to a method for preparing corresponding polymers by polymerizing ethylene or copolymerizing ethylene with other α-olefins. Background technique [0002] At present most of the homopolymerization or copolymerization of α-olefins, such as the polymerization of ethylene copolymers, is carried out in gas phase fluidized bed reactors. US Pat. No. 4,302,566 discloses a typical fluidized bed reactor for the production of ethylene homopolymerization and ethylene copolymers. In the gas phase fluidized bed polymerization reaction, the olefin polymer is formed on the surface of the catalyst particles, and the solid particles including the catalyst particles and the polymer are suspended in the fluidized bed region, that is, the polym...

Claims

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Application Information

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IPC IPC(8): C08F10/00C08F10/02C08F2/34C08F4/6592
Inventor 王常宝王海平卢玉坤李玉成
Owner CHINA PETROLEUM & CHEM CORP
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