Separation method for preparing low-carbon olefin gas through methanol conversion

Abstract

The invention discloses a separation method for preparing low-carbon olefin gas through methanol conversion, and aims to solve the problems that products with high purity such as hydrogen, methane, ethane and propane which cannot be obtained in the prior art and oxygen, carbon oxide and the like in dimethyl enther and gas impurities cannot be effectively removed. According to the method, a step of removing the carbon oxide and the oxygen is increased, a methanol prepared olefin gas material flow from which the carbon oxide and the oxygen are removed enters a deethanizing column; the material flow on the top of the deethanizing column flows through an acetylene hydrogenation reactor, six separation tanks, a demethanizing column, an ethylene rectifying column and the like in sequence to separate to obtain ethylene and ethane products; and the material flow at the bottom of the deethanizing column flows through a propyne hydrogenation reactor, a methane stripping column, a propylene rectifying column and the like in sequence to separate to obtain propene and propane products. By using the separation method, polymer grade ethylene and propene products can be obtained, and products with high purity such as hydrogen, methane, ethane and propane can also be obtained.

Description

Technical field: [0001] The invention belongs to the field of petrochemical industry and relates to a method for separating methanol to produce low-carbon olefin gas. In particular, the present invention relates to a mixture of materials comprising one or more of hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene, propane, propylene, cyclopropane, propyne and propadiene A method for recovering ethylene and propylene. Background technique: [0002] Olefins, especially light olefins (light olefins) such as ethylene and propylene, are required as raw materials for the production of higher olefins, polyethylene and polypropylene. The tube furnace cracking unit that uses naphtha as raw material to produce ethylene and propylene through steam cracking is currently the most important industrial production unit of ethylene and propylene. The cracked gas produced by cracking hydrocarbons is a mixture containing hydrogen, methane, ethan...

AI Technical Summary

Problems solved by technology

[0021] The present invention aims at the shortcomings of the method disclosed in CN1833017A that it cannot obtain products such as hydrogen, methane, ethane and propane with higher purity and does not effectively remove oxygen and carbon monoxide in dimethyl ether and flue gas impurities. The components and composition characteristics of the production of light olefin gases, and a new and highly effective separation method for the separation of polymer grade ethylene and propylene from light olefin gases

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