Method and device for separating carbon dioxide to improve mass energy of blast furnace gas

A method and a device for capturing, separating, recovering and recycling carbon dioxide in blast furnace gas provide an energy-saving technology which improves the mass energy of blast furnace gas and reduces the emission of carbon dioxide, and belong to the fields of iron and steel metallurgy as well as greenhouse gas emission reduction. The method and the device for recovering and separating the carbon dioxide in blast furnace gas consist of a gas processing system, an absorption tower, a regeneration tower, and a built-in boiling device, integrate a conventional blast furnace gas processing system, and are added with a chemical absorption system, thus leading the carbon dioxide in blast furnace gas to be captured, recovered and utilized; after partial external carbon dioxide is added, the recovered carbon dioxide is used for the gas carrier of fuel injected by a blast furnace and the blast of a hot blast furnace, and the entry of the carbon dioxide into the furnace promotes the chemical reaction in the blast furnace, thereby achieving the recycling utilization of the carbon dioxide in iron-making workshops of the blast furnace, improving the utilization rate of blast furnace gas, reducing the emission of carbon dioxide, and having significant social and environmental benefits.