Method and device for purifying coke oven gas

Abstract

The invention relates to a method for purifying coke oven gas. The method comprises the following steps of indirectly cooling coke oven gas to 300-500 DEG C through water in a primary cooler, dehydrating coke oven gas by virtue of a dehydrating tower until the moisture content is 5-10ppm, enabling dehydrated coke oven gas to enter a tar recovery tower, discharging precipitated liquid tar obtained after condensing to the outside, enabling the gas to enter a liquid ammonia recovery tower, cooling to -30 to -50 DEG C and discharging precipitated liquid ammonia to the outside, removing impurities by virtue of a methanol washing tower and enabling the purified coke oven gas to enter a purified coke oven gas tank. The device for purifying coke oven gas comprises the primary cooler, the dehydrating tower, the tar recovery tower, the liquid ammonia recovery tower and the methanol washing tower which are sequentially connected, wherein the tar recovery tower and the liquid ammonia recovery tower are respectively connected with liquid carbon oxide pipelines, the outlet formed in the bottom of the tar recovery tower is connected with a tar recovery device and the outlet formed in the bottom of the liquid ammonia recovery tower is connected with a liquid ammonia recovery device. By cooling, dehydrating, separating tar and liquid ammonia and washing with methanol, impurities and harmful substances in gas are removed, sources of clean fuels are expanded, and thus being conductive to improving the quality of high-quality fuels and reducing the air pollution.

Description

technical field [0001] The invention belongs to the technical field of refining chemical products, and relates to a method and a device for purifying coke oven gas. Background technique [0002] The traditional process of coke oven gas purification is that the coke oven gas is sprayed with a large amount of circulating ammonia water in the bridge pipe and gas collecting pipe, so that the gas is cooled to 82-86°C, and then cooled to 25-35°C in the gas primary cooler. The gas after the primary cooler enters the blower after the tar mist is captured by the electric tar collector, and is sent to the gas washing and purification section by the blower at a pressure of 25000pa. Then go through the hydrogen sulfide removal, ammonia removal, and benzene removal sections, and then the purified gas is sent out. If it is used as the raw material gas for LNG production, it needs further deep purification. The traditional process of coke oven gas purification produces a large amount of w...

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Problems solved by technology

[0003] The purpose of this invention is to provide a kind of method for coke oven gas purification, to solve the problem that a large amount of waste water is difficult to handle and the processing cost is high in the purification process, helps to reduce environmental pollution and reduce production cost; Another purpose of the present invention is Provide a kind of device that realizes above-mentioned method

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