Device and method for recycling carbon 2 in refinery dry gas by aid of oil absorption and compression condensation processes

Abstract

The invention belongs to the technical field of refinery dry gas separation and recycling, and relates to a device and a method for recycling carbon 2 in refinery dry gas by the aid of oil absorptionand compression condensation processes. The device comprises an absorption tower, a desorption tower and an ethane tower. Inlet pipelines of the absorption tower include a coking dry gas inlet pipeline and an aromatic hydrocarbon dry gas inlet pipeline, a compressor, a cooler and a liquid separation tank are arranged on the aromatic hydrocarbon dry gas inlet pipeline, and a gas-phase discharge pipeline of the liquid separation tank is connected to the absorption tower; a tower kettle of the absorption tower is connected with the desorption tower; a tower top of the desorption tower is connected with the ethane tower, and a tower kettle of the desorption tower is connected with the upper portion of the absorption tower; an ethane-rich gas discharge pipeline is connected with a tower top ofthe ethane tower, a light hydrocarbon discharge pipeline is connected with a tower kettle of the ethane tower, and a liquid-phase discharge pipeline of the liquid separation tank is connected with theethane tower. The device and the method have the advantages that the contents of hydrogen, methane and components at the levels higher than carbon 3 in ethane-rich gas in products can be controlled by the aid of the method, dryers and propylene refrigeration compressors can be omitted, and accordingly the investment and energy consumption of the device can be reduced.

Description

technical field [0001] The invention belongs to the technical field of separation and recovery of refinery dry gas, and more specifically relates to a device and method for recovering carbon dioxide in refinery dry gas by oil absorption and compression condensation. Background technique [0002] Refinery dry gas comes from secondary processing of crude oil, such as delayed coking unit dry gas, aromatics complex dry gas, etc. 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%. The dry gas of aromatics complex, such as the high molar content of ethane in the dry gas of PX plant, can reach 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 pe...

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Problems solved by technology

[0009] In order to solve the problem of large investment and high energy consumption caused by reducing the content of carbon 3 in the product gas when recovering carbon 2 in the dry gas in the existing r

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