Reaction device and method for preparing ethylene by oxidative coupling of methane

Abstract

An embodiment of the invention provides a reaction device and method for preparing ethylene by oxidative coupling of methane. The device comprises a reactor and a catalyst delivering tube, wherein thereactor comprises a fluidization region and a settling region; the settling region is positioned on the upper portion of the fluidization region, and is coaxially connected with the fluidization region, an inlet of the catalyst delivering tube is connected with the settling region, and an outlet of the catalyst delivering tube is connected with the fluidization region; a gas distributor is arranged on the lower portion of the inside of the fluidization region, an oxygen distributor and a heat exchange tube bundle are arranged in a space from the position above the gas distributor to the top of the fluidization region, and the bottom of the fluidization region is connected with one end of a raw material inlet tube; and a raising pipe, a cyclone separator and a gas collecting chamber are arranged in the settling region, the top of the settling region is connected with one end of a gas outlet tube, and one end of the raising tube is connected with the cyclone separator while the other end of the raising tube is connected with the fluidization region. According to the embodiment of the invention, catalyst particles violently move under the effect of upflow through a fluidized bed reactor, and thus, the temperature of a catalyst bed layer is distributed uniformly.

Description

technical field [0001] The invention relates to the technical field of petrochemical industry, in particular to a reaction device and method for preparing ethylene by oxidative coupling of methane. Background technique [0002] As a basic industrial raw material, ethylene occupies an important position in the petrochemical industry, and ethylene production is one of the important symbols to measure the development level of a country's petrochemical industry. Except for North America and the Middle East, most countries and regions in the world (including my country) use naphtha as raw material to produce ethylene by steam cracking. This method not only has high energy consumption, high cost, and emits greenhouse gases, but also needs to consume precious petroleum resources because the raw material comes from petroleum. Therefore, countries have carried out research on alternative routes, the main alternative sources being coal and natural gas. [0003] Since the oxidative c...

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Problems solved by technology

[0004] In order to solve the "flying temperature" phenomenon in the reaction area, researchers have proposed several methods. One is to use molten salt heat carrier to remove the heat of reaction. However, the operation of molten salt is difficult and expensive.

Second, reduce the thickness of the catalyst bed and increase the heat dissipation area, that is, the so-called "thin bed reactor". The diameter of the reactor with this structure is relatively large. Although the axial temperature difference is reduced, the radial temperature gradient is increased, resulting in The catalyst bed is heated unevenly in the radial direction, which affects the effect of the catalyst. Therefore, this type of reactor also has great limitations.

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