System for producing light benzene by performing negative pressure debenzolization on rich oil

Abstract

The invention provides a system for producing light benzene by performing negative pressure debenzolization on rich oil. The system comprises a debenzolization tower, wherein the top of the debenzolization tower is communicated with a light benzene condensation cooler through a light benzene steam pipeline, the light benzene condensation cooler is communicated with a light benzene return tank through a cooling liquid introducing pipe and a pressure balancing pipe, the light benzene return tank is connected with a light benzene return groove through a light benzene discharge pipe, the light benzene return groove is connected with the debenzolization tower through a light benzene return pipe, the light benzene return tank is provided with a non-condensable gas discharge pipe, the non-condensable gas discharge pipe is communicated with a tubular heat exchanger, a negative pressure pipe is arranged on the tubular heat exchanger, and the negative pressure pipe is communicated with a vacuum pump. The system disclosed by the invention can change ordinary pressure operation to negative pressure operation in a rich oil debenzolization distillation process, be conducive to reducing the distillation boiling point of the light benzene at the top of the tower, reduce the load of the light benzene condensation cooler, realize a smaller amount of separated water from the light benzene, eliminate the need of adopting multiple devices to separate the separated water from the light benzene, be conductive to lowering the cost of the devices, avoid great consumption of steam resources and be conductive to reducing environmental pollution.

Description

technical field [0001] The invention relates to a coal chemical industry oil-rich crude benzene distillation system, in particular to a light benzene recovery system for oil-rich negative pressure debenzene removal. Background technique [0002] At present, the final cold washing benzene section of domestic coking plants uses tar washing oil or petroleum washing oil to wash the benzene in the gas. The washing oil absorbs benzene and becomes rich oil. Oil. In order to ensure the recycling of the washing oil, the benzene in the rich oil must be removed to make it a lean oil that can be sent to the final cold washing benzene section for further benzene washing. Among the various existing processes, steam blowing is used to remove crude benzene in rich oil, and it is carried out under normal pressure conditions. In the production process, since steam is used as the heat source of distillation, a large amount of difficult-to-handle crude benzene separation water will be produc...

AI Technical Summary

Problems solved by technology

In the production process, since steam is used as the heat source for distillation, a large amount of difficult-to-handle crude benzene separation water will be produced. It is necessary to design multiple equipment to separate crude benzene and the separation water in crude benzene, and the cost of the equipment itself is relatively high.

At the same time, it consumes a lot of steam resources, and it is easy to cause serious environmental pollution, which is far from the circular economy index advocated by the country.

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