Impact of Hydrogenous Gas Injection on the Blast Furnace Process: A Numerical Investigation
Florent Mauret, Mehdi Baniasadi, Henrik Saxén, Andreas Feiterna, Stephan Hojda
Abstract
Abstract Intensifying hydrogen use in the blast furnace is a key technology for significant coke and CO 2 emissions reductions. The most straightforward approach is the implementation of high hydrogenous gas injection rates in the BF tuyeres. Yet this solution has not been widely implemented due to a lack of understanding of the impact on the furnace’s internal state. In this paper, a newly developed BF mathematical model is presented and validated on operation data. The model is next applied to investigate the effect of hydrogenous gas injection on the overall performance and internal state of the furnace. The current state of an industrial BF is used as a starting point, increasing the injection of coke oven gas, natural gas or pure H 2 to the maximum where the limits for a safe and stable process are still obeyed. All three gases were found capable of significantly decreasing the coke rate, but only coke oven gas and pure H 2 allowed for a significant reduction of the CO 2 emissions. It was found that the indirect reduction of H 2 is intensified by hydrogen enrichment partially at the expense of indirect reduction by CO. Furthermore, the water gas shift reaction is intensified at increased hydrogenous gas injection, affecting the CO and H 2 utilization of the top gas. The study gives an insight into the feasibility of BF processes with high hydrogenous gases injection into the tuyeres and the resulting coke savings.