A device and method for recovering carbon dioxide from catalytic dry gas

Abstract

The invention relates to the field of organic matter recovery from gas and discloses a device and a method for recovering C2 from catalytic dry gas. The device comprises a C4 absorption tower, a C4 desorption tower and a second gasoline absorption tower which are connected sequentially as well as a first gasoline absorption tower and a gasoline stabilization tower which are connected. The method comprises the following steps: C4 is contacted with the catalytic dry gas, so that heavy components of C2 or higher in the catalytic dry gas are absorbed; the absorbed C4 and heavy components of C2 orhigher are subjected to first rectification, and crude C2 and C4 are obtained by separation; gasoline is contacted with crude C2, then heavy components in crude C2 are absorbed, and C2 is further separated out; remaining gasoline-containing components are contacted with unabsorbed light components, C4 entrapped in the light components is absorbed, a mixture of absorbed C4 and gasoline is subjectedto second rectification, and C4 and gasoline are separated and reused to previous steps respectively. With adoption of the method, C2 can be recovered from the catalytic dry gas effectively, and content of propylene, ethane and C4 in a product is lower.

Description

technical field [0001] The invention relates to the field of gaseous organic matter recovery, in particular to a device and method for recovering carbon dioxide from catalytic dry gas. Background technique [0002] Catalytic dry gas comes from the secondary processing of crude oil, such as catalytic cracking, delayed coking and other processes. The dry gas usually contains a large amount of ethylene and ethane components. For example, the molar content of ethane in the catalytic dry gas is about 10-24%, and the molar content of ethylene is about 12-20%. At present, catalytic dry gas is mainly burned as fuel, and its utilization value is low. If the carbon two components in the dry gas are concentrated and the ethylene or ethane in it is recycled, the economic and social benefits are very obvious. One of the ways to utilize the enriched C2 enriched gas is as the raw material for the ethylbenzene plant, but the ethylbenzene plant requires that the propylene content in the ra...

AI Technical Summary

Problems solved by technology

[0008] To sum up, in order to reduce the propylene content in the product gas when recovering the carbon two components in the catalytic dry gas, the existing catalytic dry gas recovery process requires a propylene refrigeration compressor to provide low-temperature cooling capacity, and requires a A drying system is used to remove moisture in the dry gas to prevent freezing blockage, which requires large investment and high energy consumption, and the product gas contains more ethane and carbon four components, which affects the purity of the product gas ethylene

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