A kind of separation method of low-carbon olefin gas

Abstract

The invention discloses a method for separating low-carbon olefin gas. The method is used for overcoming the disadvantages in existing low-carbon olefin separation methods that cryogenic separation is complicated in process flow, large in investment and the like. The method comprises the following steps: the low-carbon olefin gas enters a deethanization tower after the low-carbon olefin gas is compressed and dried, a tower bottom material flow of the deethanization tower is conveyed to a depropanization and propylene distillation system so as to separate polymer-grade propylene products, and a tower top material flow of the deethanization tower enters a demethanization tower; and a tower bottom material flow of the demethanization tower is conveyed to an acetylene converter and an ethylene distillation tower, a tower top material flow of the demethanization tower is conveyed to an absorption tower and is in contact with an absorbent, a tower top gaseous-phase material flow of the absorption tower is output or enters a fuel gas system, and a tower bottom material flow of the absorption tower is conveyed to the deethanization tower. The method disclosed by the invention has the advantage that the cryogenic separation is simple in process flow and small in investment and can be used for producing target products, such as polymer-grade ethylene, polymer-grade propylene and the like.

Description

technical field [0001] The invention belongs to the technical field of refining low-carbon olefins, and relates to an oxygen-containing compound (mainly methanol, ethanol, dimethyl ether, C 4 ~C 10 Alcohol compounds or their mixtures, etc.) as raw materials, in the continuous reaction and regeneration process of generating low-carbon olefins as the main stream (mainly ethylene and propylene), the separation method of the product low-carbon olefin gas. Background technique [0002] Low carbon olefins (ethylene, propylene, butadiene) and light aromatics (benzene, toluene, xylene) are the basic raw materials of petrochemical industry. At present, ethylene production mainly relies on the tube furnace steam cracking process of light naphtha raw material. Due to the shortage of crude oil resources and the increasing price, naphtha resources have become more and more insufficient, and the production cost of low-carbon olefins is getting higher and higher. At home and abroad, we ...

AI Technical Summary

Problems solved by technology

[0010] The present invention aims at the shortcomings of complex cryogenic separation process and large investment in the prior art low-carbon olefin separation method, and provides a new low-carbon olefin gas separation method with simple intercooling separation process and low investment to produce polymerization-grade Purpose products such as ethylene and polymer grade propylene

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