Extending the Operating Line Methodology to Consider Shaft and Preheating Injections in Blast Furnaces

Comparing different syngas for blast furnace ironmaking by using the extended operating line methodology

“…The air-blown BF reproduces the data from Babich et al [17], characterized by 0.92 chemical efficiency, 850 • C thermal reserve zone temperature, 701.1 MJ/tHM heat losses, and 31 % H 2 utilization. The discrepancy between the results of the extended operating line model and the reference data is below 3.5 % (validation was presented in [33]). To have a fair comparison, these results were taken as basis for the elaboration of the OBF and AdOBF base cases, including modifications in the operating parameters when necessary in agreement with literature.…”

“…The extended operating line (Fig. 3) [33] was used for the modelling of the blast furnace, which is a convenient methodology for predicting changes when the operating conditions are modified. The full calculation methodology was proposed and thoroughly described by Bailera et al in 2022 [33], which is a generalization of the operating line Fig.…”

“…For these reasons, conventional Rist diagrams are not valid when aiming for evaluating the new blast furnace decarbonization concepts presented in this manuscript. Hence, the extended methodology is considered [33], which can deal with gas injections at any part of the blast furnace (i.e., no constant mole flow along the BF), and with gas injections that already contain oxidized components (i.e., a non-continuous oxidation profile during the gas ascent). It should be noted that this methodology has been recently developed, and no other study in literature has used it for assessing syngas injections in blast furnaces.…”

“…The description of these terms can be found in the nomenclature list, and a detailed explanation of the methodology can be found in the work of Bailera et al [33,37].…”

“…The utilization of syngas has not been evaluated so far in literature for the two latter types of blast furnaces. In order to do that, the extended operating line methodology is used [33]. This methodology is a recently proposed generalization of the conventional Rist diagram, to extend its application to cases in which the injected gases have large contents of CO 2 and H 2 O, and also to cases in which injections take place at the middle or upper zone of the blast furnace.…”