This deliverable presents the final techno-economic assessment of the C4U technologies when implemented in steel plants. The core of the deliverable is a paper submitted to the International Journal of Greenhouse Gas Control. The paper focuses on the technologies’ optimal system integration with the minimum fossil fuel import and maximum CO2 avoidance; however, additional hydrogen use cases are also presented.
The deliverable considers the DISPLACE process applied to the sinter plant, reheating ovens and coke oven flue gases, while the CASOH process works with the blast furnace and basic oxygen furnace gases. The analysis is performed considering actual CO2 footprint of the electricity purchased (250 kgCO2/MWh) and a more optimistic future scenario with fully renewable electricity leading to significant variation in the Key Performance Indicators (KPIs).
Overall, the CASOH process contributes to avoiding around 30% of CO2 emissions, while DISPLACE contributes to around 42% when applied to all the above considered gases. These numbers correspond to the case where all the additional electricity purchased from the grid is renewable and reduces by 20% if the electricity has a carbon footprint. Overall, the C4U cases have a CO2 avoidance that is significantly higher than the reference commercial technology. The SPECCA of C4U is strongly related to the assumption about the electricity purchased from the grid, as it can range from -4.2 GJ/tCO2 for the CASOH only with green electricity to up to 3.1 GJ/tCO2 when all the streams are processed for CO2 capture and the electricity is not green.
Finally, the resulting cost of CO2 avoided of the C4U technology is strongly dependent on the cost of electricity and NG assumed. In the case of NG and electricity prices equalling to 50 €/MWh and 125 €/MWhel, the C4U technology is more expensive than the reference case, mainly because the CO2 avoided is more than twice with consequent penalties (result equal to 138 €/tCO2, avoided). In the case of NG and electricity prices equalling to 50 €/MWh and 50 €/MWhel (representing a situation with a higher renewable energy penetration, as in Scandinavian areas), the C4U technology is cheaper than the reference case, with values which can be as low as 28 €/tCO2.
