Research of the influence of technologies using PCI, natural and coke over gas on the decarbonization of the blast furnace production

Abstract

The purpose of the work is to establish the patterns of use of various fuel additives aimed at reducing carbon dioxide emissions from the blast furnace. In connection with global warming and related negative consequences in the future, the issue of reducing greenhouse gases (including CO2) is one of the most important in the world. Thus, the issue of decarbonization of the metallurgical industry of Ukraine, which accounts for about 26% of emissions, is urgent. In Ukraine during steel production, CO2 emissions are ~8% higher than in EU countries, which is primarily due to the fact that the energy intensity of blast furnace production technology in Ukraine is greater. Therefore, with the introduction of quotas for CO2 emissions (EU ETS), without the introduction of blast furnace decarbonization technologies, Ukrainian metallurgy may become uncompetitive. With the use of improved thermal energy and exergy models of blast furnace smelting, regularities were established when using PCI (as the most economical substitute for coke), natural and coke over gas for CO2 emissions and technical and economic indicators of blast furnace smelting. The best period of operation of blast furnace No. 4 with a volume of 2002 m3 of PJSC "MK "Azovstal" in 2021 was chosen as the basic calculation option. The regularities of the effect of the use of different grades of coal for pulverized coal injection (PCI) and changes in the chemical composition of PCI while maintaining the theoretical combustion temperature at a constant level on CO2 emissions and blast furnace smelting indicators have been established, which will allow a rational approach to the choice of coal for PCI, which is especially relevant in wartime and the post-war recovery of Ukraine in the conditions of the loss of the coal energy base for PCI. For the first time, the critical consumption of fuel additives was determined, at which, according to Gruner's principle, it is expected to achieve full recovery of iron by indirect means, and therefore minimum fuel consumption when reaching rd close to 0%. As a result of the work performed, the limit values of the effectiveness of the use of PCI, natural and coke gas injection technologies on carbon dioxide emissions, output of secondary energy resources and coke consumption were established.