"AÇO VERDE": estado da arte, desafios e perspectivas para a siderurgia sustentável no Brasil

Abstract

In the context of the decarbonization of the world steel industry, this work investigates the concept of "green steel" and its state of the art, as well as seeks to answer what are the innovative technologies for the steel industry that enable the effective achievement of the goals of the global climate agreements. Among the available technologies, the direct reduction of iron ore by green hydrogen together with the use of electric arc furnaces for steel production proves to be quite effective in reducing greenhouse gas emissions, and therefore deserves special attention. It appears that the emissions from steel production using this technology could be lower than those produced by the conventional route for most European Union countries. The production of "green steel" using this technology is also analyzed in countries that have quality iron ore reserves as well as abundant renewable energies, especially solar and wind energy. It is concluded that the ideal and favorable locations for cheaper production are those located close to the Tropic of Cancer and Capricorn, where solar radiation is readily accessible. Finally, the national scenario of steel production is discussed, highlighting its particularities, challenges and advantages in the face of the global decarbonization process. A path for national decarbonization is suggested: in the short term, investments should be made in energy efficiency measures, increasing the use of electric arc furnaces with scrap and the use of charcoal in the blast furnace; in the medium term, the ore is reduced directly with natural gas, and in the long term, the ore is reduced directly with hydrogen.