Method and device for recycling saturated dry gas of refinery plant by adopting shallow cold oil absorption technology

Abstract

The invention relates to the field of dry gas treatment, the invention discloses a method and a device for recycling a saturated dry gas of a refinery plant by adopting a shallow cold oil absorption technology, the method comprises the following steps: sequentially compressing the saturated dry gas, cooling the saturated dry gas, and feeding the saturated dry gas into a C4 absorption tower for treatment, and respectively sending an obtained gas phase and an obtained liquid phase into a gasoline absorption tower and a C4 desorption tower; recovering a gas phase obtained by treating in the C4 desorption tower to serve as a C2 concentrated gas product, allowing most of an obtained liquid phase to be returned to the C4 absorption tower for recycling, and sending a small part of the obtained liquid phase to a gasoline stabilization tower; and sending the liquid phase treated by the gasoline absorption tower to the gasoline stabilization tower for treatment, allowing most of the obtained liquid phase to be returned to the gasoline absorption tower for recycling and the small part of the obtained liquid phase to serve as an extraction gasoline product, performing condensation and gas-liquid separation treatment in turn on the gas phase obtained by processing in the gasoline stabilization tower, respectively returning the obtained gas phase and the obtained liquid phase to the inlet ofa compressor, and respectively sending the obtained gas phase and the obtained liquid phase to the gasoline stabilization tower and the C4 absorption tower for treatment. The method disclosed by theinvention has the advantages that the material consumption is low, the process is simple, the investment is small, and the recovery rate of the C2 and C3 is high.

Description

technical field [0001] The invention relates to the field of refinery dry gas treatment, and more particularly, relates to a method and device for recovering refinery saturated dry gas by adopting shallow cooling oil absorption technology. Background technique [0002] Refinery dry gas is mainly produced by the primary and secondary processing of crude oil such as atmospheric and vacuum distillation, catalytic cracking, delayed coking, hydrocracking, catalytic reforming, etc. It is rich in hydrogen, methane, ethylene, ethane , propylene, propane and other light hydrocarbon resources. Refinery dry gas can be simply divided into two categories: one is unsaturated dry gas containing more olefins by-product of catalytic cracking and other devices, and the other is unsaturated dry gas containing more olefins by atmospheric and vacuum distillation, hydrogenation, reforming, coking Saturated dry gas that does not contain or only contains a small amount of olefins by-product of suc...

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Problems solved by technology

[0011] In order to achieve efficient and reliable recycling of saturated dry gas in refineries, and at the same time solve the problems of high absorbent consumption and high material consumption, the present invention provides a method and device for recovering saturated dry gas in refineries using shallow cold oil absorption technology

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