Comparative impact of blast temperature and coke oven gas pre-heating on CO 2 emissions in blast furnace

Abstract

The global commitment to achieving carbon neutrality has placed immense pressure on the steel industry, especially since blast furnace processes are responsible for most of the CO₂ emissions in steel production. Hydrogen-rich gases have efficient reduction of iron ore and non-polluting emission characteristics, notably, coke oven gas has become a focal point due to its ease of acquisition. This paper establishes a mass and heat balance model for a hydrogen-enriched blast furnace, and improves the associated CO₂ emission evaluation method. This study investigates the effects of various external heat sources on operational parameters, process indices and CO₂ emission reduction under different conditions. Results indicate that increasing gas pre-heating temperature enhances coke replacement rates and expands the operational window; however, it adversely affects blast furnace carbon emission reduction efforts. Under the investigated operating conditions, CO₂ emissions can be reduced to 1030.23 kg CO₂/tHM, with maximum reduction potentials reaching 153.81 kg CO₂/tHM. The relationship between increasing blast temperature and hydrogen-enriched gas pre-heating with carbon emissions requires further validation. Some carbon reduction strategies are proposed to address these challenges.