Cogeneration of energy in the reuse of blast furnaces gases in a steel manufacturing company / Cogeração de energia na reutilização gases de altos-fornos de uma empresa siderúrgica

Abstract

In the present work, using the tools and the concepts of energy for the steelmaking process, a detailed study of the electric energy generation system (Cogeneration) in a non-integrated steel mill coupled with a thermoelectric plant was carried out, where the production process of this steel industry, which is located in a city in the Midwest region of Minas Gerais (Brazil), was analyzed. A pig iron producer that sells in the internal and external markets, this steel industry is continuously seeking to increase its competitiveness in the steel sector and to become an ecologically sustainable company. The intention is to propose a better utilization of the gases generated in the production of pig iron in a charcoal blast furnace. That is, since the gas flow from the blast furnace, which serves as fuel in the combustion process in the boiler, does not have a regular or constant flow, it is necessary to monitor the air/fuel ratio almost in real time, in order to obtain the highest power in the turbo-generator set of the steam system. Through the energy analyses performed for each of the components of the energy generation cycle of the steel mill, improvement proposals are suggested to increase the energy efficiency of the components and, consequently, of the cycle as a whole.