Method for joint production of natural gas and liquid ammonia by using coke oven gas and blast-furnace gas

Abstract

The invention relates to a method for joint production of natural gas and liquid ammonia by using coke oven gas and blast-furnace gas. The method comprises the following steps: firstly, pressurizing the coke oven gas through a Roots blower or a screw compressor; feeding to the compressor and carrying out first-stage and second-stage compression pressurization through a temperature swing adsorption device; carrying out third-stage compression pressurization through the compressor after passing through a pressure swing adsorption decarburizing device; feeding to a coke oven gas desulphurization device, feeding to a methane synthesis device and obtaining a natural gas or liquefied natural gas product through the pressure swing adsorption device or a cryogenic separation device; carrying out first-stage and second-stage compression pressurization on the coke oven gas through the compressor, mixing with vapor, feeding to a sulphur-tolerance shift device, and carrying out low-temperature sulphur-tolerance shift; sequentially feeding to a blast-furnace gas desulphurization device, the pressure swing adsorption decarburizing device and a pressure swing adsorption denitrification device; and mixing the purified blast-furnace gas with nitrogen and hydrogen, which are separated from the coke oven gas, then carrying out third-stage, fourth-stage, fifth-stage and sixth-stage compression pressurization through the the compressor, and feeding to a synthesis ammonia device after passing through a methanation device, so as to produce an anhydrous liquid ammonia product.

Description

technical field [0001] The invention relates to a process for jointly producing natural gas and liquid ammonia by using coke oven gas and blast furnace gas, and belongs to the field of comprehensive utilization of gas in iron and steel enterprises. Background technique [0002] Coke oven gas is a combustible gas obtained in the coking process. Generally, 300-350 m3 of coke oven gas can be produced per ton of dry coal 3 , The coke oven itself uses up about half of it. Coke oven gas is a mixture, its yield and composition vary with the quality of coking coal and coking process conditions, and its main component is H 2 (55%-70%) and CH 4 (15%-30%), CO(5%-9%), CO 2 (2%-5%), N 2 (2%-6%), also contains a small amount of other ingredients. [0003] Blast furnace gas is a by-product produced in the process of ironmaking, and about 1500m3 of blast furnace gas is produced for every ton of pig iron smelted 3 , The blast furnace itself uses up nearly half of the hot blast stove. ...

AI Technical Summary

Problems solved by technology

In blast furnace gas, carbon monoxide accounts for about 30%, carbon dioxide accounts for about 10%, nitrogen accounts for about 55%, and a small amount of hydrogen and methane, so the calorific value is very low

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