Method for recovering carbon dioxide in refinery dry gas

Abstract

The invention relates to the field of dry gas treatment, and in particular, discloses a method for recovering carbon 2 in refinery dry gas, wherein the method comprises: 1) compressing and cooling the aromatic hydrocarbon dry gas in sequence; 2. ) The coking dry gas is sent into the coking dry gas compressor for compression treatment, and the gas phase obtained by the cooling phase separation process described in step 1) is sent into the coking dry gas compressor section or outlet; 3) the coking dry gas is The mixed dry gas collected at the outlet of the gas compressor is cooled and processed, and then the carbon four fraction is used as an absorbent to carry out absorption processing in the absorption tower; The column bottom stream of the absorption tower is sent to the desorption tower for desorption treatment. The recovery method of the invention has a high carbon 2 recovery rate, does not need a propylene refrigeration system and a drying system, and has a low content of components above carbon 3 in the product gas, and has the advantages of low energy consumption and low investment.

Description

technical field [0001] The invention relates to the field of dry gas treatment, in particular to a method for recovering carbon dioxide in refinery dry gas. Background technique [0002] Refinery dry gas, such as delayed coking unit dry gas, aromatics complex dry gas, etc., comes from the secondary processing of crude oil. Dry gas usually contains a large amount of ethane components, for example, the molar content of ethane in coking dry gas is about 10-24%, and the dry gas of aromatics complex, such as the molar content of ethane in the dry gas of PX unit is about 25-70% %. At present, refinery dry gas is mainly burned as fuel, and its utilization value is low. If the ethane component in the dry gas is concentrated and sent to the ethane cracking furnace of the ethylene plant as raw material, the economic and social benefits are very obvious. Since the cracking performance of the ethane component in the raw material of the ethane cracking furnace of the ethylene plant is...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to overcome the difficulty of separating carbon two and carbon three components in the dry gas by using the existing method for recovering refinery dry gas, which requires the use of low-temperature cooling capacity, which will lead to large investment, high energy consumption, and carbon four To solve the problem of large amount of absorbent circulation, a method for recovering carbon dioxide in refinery dry gas is provided, wherein the method includes:

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