Assessment of the possibility of ferrous metallurgy decarbonization

Abstract

The analysis of the known methods of decarbonization of the production process ferrous metals is given. It is shown that the most effective ways to reduce CO2 emissions from metallurgical enterprises into the environment are sorption from exhaust gases and replacing carbon fuel with hydrogen. However, sorption methods for capturing CO2 are too expensive due to the high cost of sorbents and are accompanied by the formation of a large amount of waste (4.5–8 t/t of rolled stock), for the placement of which large areas are required. Abandoning sinter-blast furnace production and switching to conversion metallurgy will reduce the carbon footprint by 75 %, however, due to the scarcity of scrap, the possibilities of this method are limited. Switching to directpr duction of iron, provided that all types of fuel are replaced by hydrogen, will reduce the carbon footprint by 90 %. At the same time, it will be necessary to have 181 kg of H2 for the production of 1 ton of rolled metal throughout the cycle. To supply all world steel companies with hydrogen, the existing hydrogen-producing capacities will have to be increased at least sixfold. Obtaining hydrogen for the needs of ferrous metallurgy using the cheapest conversion method will increase the cost of rolled products by at least one third, and obtaining this gas by electrolysis will double the cost of rolled products. It will be necessary to create power plants operating with alternative energy sources such as solar panels and wind generators to cover the needs of the metallurgical plant in electricity taking into account the cost for generating hydrogen. The allocation of such plants will require large areas, that are difficult to withdraw from farmland. Decarbonization of ferrous metals production is a complex and costly task, and therefore can be realized only in the long run.