The Project aims to advance the technologies essential for de-carbonizing and de-fossilizing the steel-making industry in Taiwan through CCU in the course of partially substituting carbon with hydrogen in blast furnaces and DRI shaft furnaces. In particular, the development of top gases of the shaft furnace is being studied simulatively, CO2 utilization concepts and cell systems for seawater electrolysis are being further developed, processes for the direct use of dissolved CO2 are being researched and an overall system model for higher-level simulations and analysis is being generated. This work will contribute to de-carbonizing the steel-making industry before the full transition to hydrogen-based green steel. The modeling study on blast furnaces and DRI shaft furnaces will gain a better understanding of how hydrogen injection impacts the top gas compositions. The innovative CO2 utilization methods and electrolysis cells, and system modeling tools can help reduce carbon emissions and will have the potential to be applied to other sectors such as power plants, the cement industry, the chemical industry, and blue hydrogen production.