Process and apparatus for controlling continuous and stable discharge of non-condensable gas in benzene recovery system

Abstract

The present invention relates to a process and an apparatus for controlling the continuous and stable discharge of non-condensable gas in a benzene recovery system. According to the process, benzene steam produced from the top of a benzene removing tower enters a condensation cooler to be cooled by a low-grade cold source and a high-grade cold source in a segment manner so as to obtain a benzene-water mixture; the benzene-water mixture enters a gas-liquid mass transfer and heat transfer device in a self-flow manner and flows toward a benzene-water separator on the lower portion, the gas phase in the condensation cooler enters the benzene-water separator and flows toward the gas-liquid mass transfer and heat transfer device on the upper portion, and the pressure in the system is controlled at -80-45 kPa; and in the gas-liquid mass transfer and heat transfer device, the gas phase and the liquid phase are subjected to countercurrent contact, the high-boiling point organic component in the gas phase is condensed, the condensed component enters the benzene-water separator, the non-condensable gas is cooled, and the cooled gas is continuously and stably discharged from the top portion. With the process and the apparatus of the present invention, the non-condensable gas in the benzene recovery system can be continuously and stably discharged, such that the crude (light) benzene quality and the yield can be ensured while the instability factor of the benzene removing tower operation can be eliminated, and the safety of the benzene recovery system can be improved; and the process is simple, the equipment layout is compact and rational, and the installation and the maintenance are convenient.

Description

technical field [0001] The invention relates to the technical field of recycling coking chemical products in the metallurgical coking industry, in particular to a process and a device for controlling the continuous and stable discharge of non-condensable gas in a benzene recovery system. Background technique [0002] At present, the production of crude (light) benzene in coking plants generally adopts the following process: the gas is washed in the benzene washing tower to remove the benzene medium, and the washing oil (rich oil) rich in benzene is obtained. After the rich oil is heated, it is sent to the degassing tower Distilled in the benzene tower, the benzene vapor distilled from the top of the tower is cooled by the condensing cooler and separated by the benzene-water separator to obtain crude (light) benzene products, and the lean oil at the bottom of the tower is sent to the benzene washing tower for recycling after cooling. The benzene vapor distilled at the top of ...

AI Technical Summary

Problems solved by technology

This process has the following problems: 1) the discharge of non-condensable gas is not smooth, and the pressure fluctuation in the debenzene tower is large, which will lead to the disorder of the debenzene tower process in serious cases, and it is difficult to guarantee the product quality; 2) when the non-condensable gas is discharged, there will be Uncondensed benzene vapor will affect the yield of crude benzene on the one hand, and easily cause safety accidents on the other hand

Images