System and method for preparing LNG and co-producing hydrogen by deeply purifying coke oven gas

Abstract

The invention provides a system and a method for preparing LNG and co-producing hydrogen by deeply purifying coke oven gas, and belongs to the field of coke oven gas purification. A pre-washing tower is arranged as a supergravity rotating device, so that the coke oven gas subjected to benzene removal can be subjected to primary impurity removal in the pre-washing tower through a supergravity rotating technology, and harmful substances such as dust, benzene, tar, naphthalene, ammonia and sulfur in the coke oven gas subjected to benzene removal are deeply removed; and the problems that sulfur and ammonia in the coke oven gas exceed the standard to influence stable operation of a system, tar and naphthalene in the coke oven gas can cause blockage of a compression system, and the operation cost is increased due to the fact that a desulfurization adsorbent for fine desulfurization loses efficacy in advance due to abnormal coarse desulfurization are solved. Through pretreatment, the coke oven gas does not need to be desulfurized after returning to the coke oven, so that the investment and desulfurization waste liquid can be reduced. CH4, CO and H2 are separated out through coke oven gas cryogenic separation, then LNG is prepared through methanation reaction, and meanwhile, a high-purity hydrogen product is produced as a byproduct.

Description

Technical field [0001] The present invention relates to the field of coke oven gas purification technology, and more particularly to a system and method of coke oven gas depth purification, LNG co-produced hydrogen gas. Background technique [0002] Coke oven gas is an important by-product obtained in the coke process. The study of the composition of coke oven gas in recent years has been quite mature. The coke oven gas belongs to the medium heat value, the hydrogen content is 50% ~ 60%, and the methane is 22% to 24%, including huge utilization value. In the production of coke, a large number of coke oven gas is generated. If a coke oven gas calculation is produced in accordance with the production of 1 ton of coke, my country's annual coke oven gas generation is basically maintained at 180 billion cubic meters, of which 45-50% is about 45-50%. The coke oven gas returns the coke oven, and the remaining coke oven gas is considerable. Therefore, how to recycle the coke oven gas on ...

AI Technical Summary

Problems solved by technology

[0012] In order to solve the current comprehensive utilization of coke oven gas, it will affect the stable operation of the post-system, cause compressor blockage, cause premature desulfurization of fine desulfurization agent and increase operating costs, high sulfur content in coke oven gas returned to the coke oven, and To solve the technical problem of making the yield of hydrogen relatively low, the present invention provides a system and method for deep purification of coke oven gas to LNG and co-production of hydrogen

Images