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Ruukki, Finland

Arasto A.,VTT Technical Research Center of Finland | Tsupari E.,VTT Technical Research Center of Finland | Karki J.,VTT Technical Research Center of Finland | Pisila E.,Ruukki Metals Oy | Sorsamaki L.,VTT Technical Research Center of Finland
International Journal of Greenhouse Gas Control | Year: 2013

In this study different possibilities for applying post-combustion capture at an integrated steel mill in order to reduce carbon dioxide emissions were studied. Implications of different amounts of CO2 captured, different solvents for post-combustion capture and different heat supply options for solvent regeneration to the energy balance and greenhouse gas emissions of the steel mill are compared to that of the base case for the steel mill. The case study is based on Ruukki Metals Ltd.'s Raahe steel mill that is situated on the coast of the Gulf of Bothnia. It is the largest integrated steel mill in the Nordic countries producing hot rolled steel plates and coils. It is also the largest CO2 point source in Finland emitting approximately 4Mt/year. Carbon capture processes were modelled using Aspen Plus process modelling software and results were used to estimate the potential for reducing CO2 emissions at an integrated steel mill from a plant operator's point of view. Different heat integration options and heat utilization scenarios were investigated. The heat available for solvent regeneration varied between these heat utilization scenarios and thus partial capture of CO2 was investigated with the CO2 amount captured depending on the heat available for solvent regeneration in the different case studies. The results of the study show a significant CO2 reduction potential using CCS. Approximately 50-75% of the emissions from the site could be captured using post-combustion capture. Capturing a larger amount of emissions would be technically less feasible due to the large number of small stacks around the large, integrated steel mill site. © 2012 Elsevier Ltd.

Tsupari E.,VTT Technical Research Center of Finland | Karki J.,VTT Technical Research Center of Finland | Arasto A.,VTT Technical Research Center of Finland | Pisila E.,Ruukki Metals Oy
International Journal of Greenhouse Gas Control | Year: 2013

In this paper the economics of the technical possibilities presented in Part I (Arasto et al., 2013) for applying post-combustion CO2 capture at an integrated steel mill were studied. Implications of different CO2 amounts captured, solvents and process integration levels to the greenhouse gas balances and economics of operation are compared to the reference case without CCS trough several case studies using variable market prices of electricity and CO2 emission allowances. The break-even price (BEP) of CO2 emissions (e.g. CO2 emission allowances), where CCS becomes more profitable than the reference case, is about 72€/t CO2 with an electricity price of 100€/MWh in the most favourable studied case using a MEA solvent. For the more advanced solvents considered, the BEP level is about 64€/t CO2. With higher prices of electricity, the costs for CCS increase rapidly. The costs for globally avoided emissions, based on a streamlined life-cycle analysis, are generally higher than the BEP's, depending on the fuels that are assumed to eventually compensate the decreased electricity production in the energy system. The amounts of captured CO2 corresponding to the above presented prices in the most favourable cases are typically in the range of 2-3Mt CO2/a, which accounts for 50-75% of the site emissions. © 2012 Elsevier Ltd.

Kaijalainen A.J.,University of Oulu | Suikkanen P.,Ruukki Metals Oy | Karjalainen L.P.,University of Oulu | Jonas J.J.,McGill University
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2014

The effect of austenite pancaking in the non-recrystallization regime on microstructure and texture evolution and thereby on bendability was investigated in an ultrahigh-strength strip steel with a martensitic-bainitic microstructure. The results indicate that an increase in rolling reduction (R tot) below the non-recrystallization temperature, which improves the strength and toughness properties, increases the intensities of the ∼{554}〈225〉 α and ∼{112}〈110〉 α texture components along the strip centerline and of the ∼{112}〈111〉 α component at the surface region. Even with the highest R tot of 79 pct, the bendability along the rolling direction was good, but the preferred alignment of rod-shaped MA constituents along the rolling direction led to a dramatic decrease in the bendability transverse to the rolling direction, with severe cracking occurring even at small bending angles. The early cracking is attributed to localization of the strain in narrow shear bands. It is concluded that the Rtot value has to be limited to guarantee successful bendability. © 2013 The Minerals, Metals & Materials Society and ASM International.

Suikkanen P.P.,Ruukki Metals Oy | Cayron C.,CEA Grenoble | DeArdo A.J.,University of Pittsburgh | Karjalainen L.P.,University of Oulu
Journal of Materials Science and Technology | Year: 2013

The crystallography of bainite, transformed isothermally at 450 °C in 0.2C-2.0Mn-1.5Si-0.6Cr steel, was investigated by electron backscatter diffraction (EBSD) analysis. The orientation relationship (OR) was found to be closer to Nishiyama-Wassermann (N-W) than Kurdjumov-Sachs orientation relationship. Bainite microstructure consisted of parallel laths forming a morphological packet structure. Typically, there were three different lath orientations in a morphological packet. These orientations were dictated by a three specific N-W OR variants sharing the same {111} austenite plane. A packet of bainite laths with common {111} austenite plane was termed as crystallographic packet. Generally, the crystallographic packet size corresponded to the morphological packet size. Locally, crystallographic packets with only two dominant orientations were observed. This indicates strong local variant selection during isothermal bainite transformation. The relative orientation between the variants in crystallographic packets was found to be near 60°/<110>. This appears to explain the strong peak observed in the grain boundary misorientation distribution near 60°. Bainite also contained pronounced fraction of boundaries with their misorientation in the range of 2.5°-8° with quite widely dispersed rotation angles. Spatially these boundaries were found to locate inside the bainite laths, forming lath-like sub-grains. © 2013.

Arasto A.,VTT Technical Research Center of Finland | Tsupari E.,VTT Technical Research Center of Finland | Karki J.,VTT Technical Research Center of Finland | Lilja J.,Ruukki Metals Oy | Sihvonen M.,Ruukki Metals Oy
International Journal of Greenhouse Gas Control | Year: 2014

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. © 2014 Elsevier Ltd.

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