Oxygen blast furnace with CO₂ capture and storage at an integrated steel mill-Part I:Technical concept analysis

In this study application of OBF with and without CCS to an integrated steel mill is investigated. The study is based on the real, Ruukki Metals Ltd.'s existing steel mill, located in the city of Raahe, Finland. Implications of application of OBF to energy and mass balances at the site are studied. Based on the technical evaluation, costs and feasibility for carbon capture are estimated. The energy and mass balance basis is presented in this first part of the series of two papers. Costs, feasibility and sensitivity analysis are assessed in the second part of the series (Tsupari et al. 2014. Int. J. Greenhouse Gas Control).The impact of applying OBF at an integrated steel mill is evaluated based on a consequential assessment following the methodology of Arasto et al. (2013). Int. J. Greenhouse Gas Control 16 (August) pp. 271-277 concentrating only on the parts of the steelmaking processes affected by the deployment of OBF and CO2 capture. The technical processes, CO2 capture and the steelmaking processes affected were modelled using Aspen Plus process modelling software and the results were used to estimate the CO2 emission reduction potential with OBF technology at an integrated steel mill.The results show that the CO2 emission from an iron and steel mill can be significantly reduced by application of an oxygen blast furnace and CCS. By applying only the blast furnace process, the emissions can already be reduced by 1.2Mt/a without storing the separated CO2. If captured CO2 is also purified and stored permanently, the emission can be further reduced by an additional 1.4Mt/a. This is a significant reduction considering that the production of the mill stays the same as in the reference case. In addition to carbon footprint of the production, application of oxygen blast furnace also has significant impact on coke consumption and energy balance on the site.