**4. Conclusions**

In this study, a thermodynamic model was used to determine the utilisation efficiency of H2-rich gas by considering H2 behaviour at different reduction stages. A static mass and energy balance model of the BF was adopted with this thermodynamic model. The effect of injecting H2-rich gas on BF performance was determined in terms of its coke consumption, CO2 emissions, and energy consumption. Under these simulation conditions, the major findings of this study were:


hydrogen due to the high electricity consumption in the CO2 capture and electrolyser. Developing a CO2 conversion unit with higher efficiency but less energy consumption is strongly recommended.

**Author Contributions:** Conceptualization, Y.H., T.E.R., V.R. and G.W.; methodology, Y.H. and G.W.; software, Y.H.; validation, Y.H. and L.H.; formal analysis, Y.H.; investigation, Y.H., Y.Q., J.C. and L.H. resources, L.H.; data curation, Y.H.; writing—original draft preparation, Y.H.; writing—review and editing, Y.H., Y.Q., J.C., L.H., T.E.R. and G.W.; visualization, Y.H.; supervision, T.E.R., V.R. and G.W.; project administration, G.W. and L.H.; funding acquisition, L.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by HBIS (China) gran<sup>t</sup> number ICSS2017-04.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data sharing not applicable. No new data were created or analysed in this study. Data sharing is not applicable to this article.

**Acknowledgments:** The authors gratefully acknowledge HBIS Group Company Limited for funding support and the scholarship support from the University of Queensland.

**Conflicts of Interest:** The authors declare no conflict of interest.
