Pyrolysis gas separation system with cooling capacity recovery function and separation method thereof

Abstract

The invention discloses a pyrolysis gas separation system with a cooling capacity recovery function and a separation method thereof. The separation system comprises a compressor, a purification system, a cooler, a gas-liquid separation tank, an absorption tower, a desorption tower, a heavy component removal tower, a cold energy recovery system and a C2 hydrogenation reactor, the compressor sections are connected with the purification system and then connected with a compressor rear section; a rear-section outlet of the compressor is connected with the cooler and then connected with the gas-liquid separation tank, a gas-phase outlet of the separation tank is connected with the absorption tower, and a liquid-phase outlet of the separation tank is connected with the de-heavy tower; the top of the absorption tower is connected with a cooling capacity recovery system; the bottom of the absorption tower is connected with the desorption tower; crude ethylene gas is extracted from the top of the desorption tower; the desorption tower kettle is connected with the upper part of the absorption tower; and a heavy component removal tower top pipeline is combined with a desorption tower top pipeline and then is connected with the C2 hydrogenation reactor. The system and the method have the characteristics of low investment, low energy consumption and remarkable benefit.

Description

technical field [0001] The invention relates to the technical field of cracking and separation, and furthermore, relates to a cracking gas separation system and a separation method with cooling capacity recovery. Background technique [0002] A large amount of tail gas will be produced in the process of oil refining and chemical production, some of which, such as tail gas produced by catalytic cracking, thermal cracking, delayed coking, hydrocracking and other production processes, contain a lot of carbon 2 and carbon 3 components, especially some tail gas In , the ethane / propane content is relatively high. At present, the C2C3 concentrated gas recovered from the tail gas of the refinery is mainly sent to different sections of the ethylene plant to increase the production of ethylene propylene. However, for refineries without ethylene production facilities nearby, the concentrated gas The whereabouts is a major problem, resulting in the C2C3 resources in the dry gas not bei...

AI Technical Summary

Problems solved by technology

However, no matter what kind of separation process is used, if the rectification method is used to separate light components such as methane, it is necessary to use a cold box to provide a lower cooling capacity, which requires a large investment and high energy consumption.

In addition, to obtain polymer-grade ethylene products and polymer-grade propylene products, the number of required equipment and energy consumption are relatively large

[0005] For refineries without ethylene production facilities nearby, if the saturated resources are cracked and the cracked gas is separated by traditional cryogenic separation methods, the return on investment will be low and the energy consumption will be high

[0006] Therefore, it is urgent to develop a separation method and utilization of cracked gas to reduce the problems of large investment and high energy consumption in the cracked gas separation process.

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