Separation process for preparing low-carbon alkene gases through conversion of methanol

Abstract

The invention discloses a separation process for preparing low-carbon alkene gases through conversion of methanol and aims to solve the problems that high-purity products such as hydrogen, methane, ethane and propane cannot be obtained and oxygen and carbon monoxide in dimethyl ether and gas impurities cannot be effectively eliminated in the prior art. According to the alkene gas streams through conversion of methanol, eliminating steps of oxygen and carbon monoxide are added, the alkene gas streams through conversion of methanol after elimination of oxygen and carbon monoxide sequentially passes six knockout drums and then enters a low-pressure demethanizer, a deethenizer, an acetylene hydrogenation reactor, an ethylene rectification tower, an allylene hydrogenation reactor and a propylene rectification tower for separation, the liquid from the bottoms of the first four knockout drums sequentially enter the middle-upper portion of the demethanizer, and the liquid from the bottom of the fifth knockout drum enters the upper portion of the demethanizer or returns to a section of a compressor. The separation process for preparing the low-carbon alkene gases through conversion of methanol can obtain products such as polymer grade ethylene, propylene, and the high-purity products such as hydrogen, methane, ethane and propane.

Description

Technical field: [0001] The invention belongs to the field of petrochemical industry, and relates to a separation process for preparing low-carbon olefin gas by converting methanol. Specifically, the present invention relates to a mixed feedstock comprising one or more of hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene, propane, propylene, cyclopropane, propyne and propadiene The process of recovering ethylene and propylene from the medium. 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 containi...

AI Technical Summary

Problems solved by technology

[0020] The present invention aims at the disadvantages that the method disclosed in CN1833017A 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 low-carbon olefin gases, and a new and highly effective separation process for the separation of polymer-grade ethylene and propylene from low-carbon olefin gases

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