Fine purification technique for coke oven gas

Abstract

The invention relates to a low energy dissipation, pollution-free, low corrosion coke oven gas purification process without producing waste water. The process comprises the steps that. coke oven gas is fed into the lower end of a benzol washer; wash oil is sprayed down from the top of the benzol washer to absorb benzene-type substance; purified coke oven gas is produced at the upper end of the wash oil, and rich oil is produced at the bottom of the benzol washer; b. the rich oil is heated and is fed into a benzole scrubber; pure nitrogen is heated and fed to the bottom the benzole scrubber toabsorb the benzene-type substance in the rich oil; gaseous mixture is produced at the upper end of the benzole scrubber, and lean oil is produced at the bottom of the benzole scrubber; c. water and little crude benzol are separated from the gaseous mixture through back flow and cooling; the remaining gaseous mixture is compressed, and cooled to produce crude benzol and nitrogen. The nitrogen involved in the process does not produce phenol water and is free of pollution through washing benzene, and compression recycle. The crude benzol meets the quality requirement of YB / T5022-93, and lean oilproduced after rich oil is debenzolized contains 0.2 to 0.4 percent of benzene.

Description

technical field [0001] The invention relates to a purification process for coke oven gas, in particular to a purification process for removing benzene in coke oven gas with washing oil. Background technique [0002] In the current coke oven gas purification process, oil washing is generally used to remove benzene substances in coke oven gas to form benzene-rich oil, and then the rich oil is converted into lean oil through debenzene removal for circular washing of benzene substances in the gas. The main process of debenzene is carried out in the debenzene tower. When the hot rich oil is sent into the tower from the upper part of the tower, due to the sudden increase of the space in the tower, some volatile benzene substances are vaporized from the rich oil to form gas rising. The wash oil which also contains a considerable amount of benzenes flows down through each layer of trays from top to bottom. At the same time, the water vapor and oil vapor from the regenerator enter ...

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Problems solved by technology

However, a large amount of direct steam feeding will result in high steam consumption, increased loads on the debenzene tower and partial condenser, and increased phenol water content, which will not only easily cause environmental pollution, but also cause NH in the oil to be enriched during the debenzene process due to the action of water vapor. 3 、H 2 S, etc. intensify the corrosion of equipment

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