PROSPECTS FOR REDUCTION ATMOSPHERIC EMISSIONS FROM IRON AND STEEL PLANTS

Global climate change and air pollution represent one of the greatest challenges of the 21st century. The main source of greenhouse gas emissions (GHG) is represented by the steel industry. In addition, from an integrated cycle steel plant, such as the one in Taranto, other compounds, harmful to human health and the ecosystem, are released into the atmosphere in relation to polluting plants, such as those of the coke oven and sintering. Polychlorinated dioxins and furans are formed in the sintering plant while polycyclic aromatic hydrocarbons in coke oven processes. Although various technologies have been adopted in recent years to reduce the emissions of these compounds, the current challenges concern the modification of the steel production process. The green transition to clean energy production and decarbonisation to reduce greenhouse gas emissions is one of the hottest topics in heavy industry. In this direction, various technologies have been developed to reduce the environmental impact such as the recovery of gas (CO2 and CO), the elimination of the coking plant and the direct use of coal for the reduction of iron ores (Corex and Finex technologies). The use of natural gas (methane) to produce reducing gas (Midrex process) was found to be effective to reduce CO2, benzopyrene and dioxins emissions. But it is the "green steel", produced with the use of hydrogen from renewable sources, which could be the future also for the historic steel mill in Taranto. Among the different ways in which hydrogen can be produced, the use of renewable energy combined with electrolysis processes could be the priority way to drastically reduce emissions into the atmosphere. In this paper, all the strategies described above are discussed.