Dry gas returning device for aromatization production system

Abstract

The invention relates to a dry gas returning device for an aromatization production system. The device comprises an absorption tower, a feed material-product heat exchanger tube pass, a feed heating furnace, an aromatization reactor group, a feed material-product heat exchanger shell pass, an air cooler, a water-cooled heat exchanger, a gas-liquid separation tank and a dry gas compressor. An outlet of the dry gas compressor is communicated with a feed pipeline at the bottom of the absorption tower through a pipeline, a connection pipeline between the absorption tower and the feed material-product heat exchanger tube pass is equipped with a flow regulating valve and a pressure regulating valve, the top of the gas-liquid separation tank is communicated with an inlet of the dry gas compressor through a pipeline, and the bottom of the gas-liquid separation tank is communicated with a qualified product pipeline and a blowdown pipeline respectively through a pipeline. The device provided by the invention has the advantages that: the absorption tower dry gas serves as the returning gas to replace high pressure nitrogen, the returning efficiency is better and the dosage is less relative to high pressure nitrogen, thus saving nitrogen; the absorption tower dry gas is recycled; and the absorption tower dry gas does not bring in water or other impurities, thus completely avoiding generation of newly increased sewage.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a dry gas return device of an aromatization production system. Background technique [0002] The aromatization catalyst is regenerated every three months, and the aromatization reactor needs to be returned every time the catalyst is regenerated. The product in the aromatization reactor is returned to the qualified product pipeline through the material return operation. In the prior art, high-pressure nitrogen is usually used to return the material. The specific process of the material return is as follows: nitrogen (3-5 kg ​​pressure), consumption 15t / h, passing through the feed regulating valve (flow control), feed-product heat exchanger (pipe side), feed heating furnace and aromatization reactor in turn, after nitrogen and product flow out from the aromatization reactor Together, they pass through the feed / product heat exchanger (shell side), air cooler and water ...

AI Technical Summary

Problems solved by technology

The disadvantages of the above-mentioned nitrogen gas return are: although it is high-pressure nitrogen, its actual pressure is limited, so the dosage is large and the cost is relatively high; nitrogen is easy to bring in impurities, especially water, and water is easy to accumulate at the bottom of the buffer tank , it is easy to carry oil when cutting water, and produce new sewage

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