| 1. |
- Haapakangas, Juho, et al.
(författare)
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Coke Reactivity in Simulated Blast Furnace Shaft Conditions
- 2016
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Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science. - : Springer Science and Business Media LLC. - 1073-5615 .- 1543-1916. ; 47:4, s. 2357-2370
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Tidskriftsartikel (refereegranskat)abstract
- Despite the fact that H2 and H2O are always present in the gas atmosphere of a blast furnace shaft, their role in the solution-loss reactions of coke has not been thoroughly examined. This study focuses on how H2 and H2O affect the reaction behavior and whether a strong correlation can be found between reactivity in the conditions of the CRI test (Coke Reactivity Index) and various simulated blast furnace shaft gas atmospheres. Partial replacement of CO/CO2 with H2/H2O was found to significantly increase the reactivity of all seven coke grades at 1373 K (1100 °C). H2 and H2O, however, did not have a significant effect on the threshold temperature of gasification. The reactivity increasing effect was found to be temperature dependent and clearly at its highest at 1373 K (1100 °C). Mathematical models were used to calculate activation energies for the gasification, which were notably lower for H2O gasification compared to CO2 indicating the higher reactivity of H2O. The reactivity results in gas atmospheres with CO2 as the sole gasifying component did not directly correlate with reactivity results in gases also including H2O, which suggests that the widely used CRI test is not entirely accurate for estimating coke reactivity in the blast furnace.
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| 2. |
- Suopajärvi, Hannu, et al.
(författare)
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Life cycle CO2 emission reduction in nordic integrated steel plant by applying biomass-based reducing agents
- 2018
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Ingår i: European Biomass Conf. Exhib. Proc.. ; , s. 1420-1424
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Konferensbidrag (refereegranskat)abstract
- The use of biomass in iron and steelmaking as a reducing agent or as a source of energy has been identified as one of the possible solutions to reduce the fossil CO2 emissions for this carbon intensive industry. Despite the growing interest, there is very little knowledge concerning the CO2 emission reduction potential of using biomass-based fuels in iron and steelmaking processes. In this research, a life cycle CO2 analysis is made to compare life cycle CO2 emission profile of steel production in a Nordic integrated steel plant to different biomass scenarios in which pulverized coal injection to the blast furnace is partially or completely replaced with biomass-derived reducing agents. The system boundary is defined from cradle-to-gate and life cycle inventory is made by combining traditional life cycle modeling practices with process modeling done by sophisticated BF energy and mass balance model.
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| 3. |
- Suopajärvi, Hannu, et al.
(författare)
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Use of biomass in integrated steelmaking – Status quo, future needs and comparison to other low-CO2 steel production technologies
- 2018
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 213, s. 384-407
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides a fundamental and critical review of biomass application as a reducing agent and fuel in integrated steelmaking. The basis for the review is derived from the current process and product quality requirements that also biomass-derived fuels should fulfill. The availability and characteristics of different sources of biomass are discussed and suitable pretreatment technologies for their upgrading are evaluated. The existing literature concerning biomass application in bio-coke making, blast furnace injection, iron ore sintering and production of carbon composite agglomerates is reviewed and research gaps filled by providing insights and recommendations to the unresolved challenges. Several possibilities to integrate the production of biomass-based reducing agents with existing industrial infrastructures to lower the cost and increase the total efficiency are given. A comparison of technical challenges and CO2 emission reduction potential between biomass-based steelmaking and other emerging technologies to produce low-CO2 steel is made.
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| 4. |
- Toloue Farrokh, Najibeh, et al.
(författare)
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Slow pyrolysis of by-product lignin from wood-based ethanol production– A detailed analysis of the produced chars
- 2018
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 164, s. 112-123
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Tidskriftsartikel (refereegranskat)abstract
- Slow pyrolysis as a method of producing a high-quality energy carrier from lignin recovered from wood-based ethanol production has not been studied for co-firing or blast furnace (BF) applications up to now. This paper investigates fuel characteristics, grindability, moisture uptake and the flow properties of lignin chars derived from the slow pyrolysis of lignin at temperatures of 300, 500 and 650 °C (L300, L500 and L650 samples respectively) at a heating rate of 5 °C min-1. The lignin chars revealed a high mass and energy yield in the range of 39-73% and 53-89% respectively. Pyrolysis at 500 °C or higher, yielded lignin chars with low H/C and O/C ratios suitable for BF injection. Furthermore, the hydrophobicity of lignin was improved tremendously after pyrolysis. Pyrolysis at high temperatures increased the sphericity of the lignin char particles and caused some agglomeration in L650. Large and less spherical particles were found to be a reason for high permeability, compressibility and cohesion of L300 in contrast to L500 and L650. L300 and L500 chars demonstrated high combustibility with low ignition and burnout temperatures. Also, rheometric analysis showed that L500 has the best flow properties including low aeration energy and high flow function.
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| 5. |
- Wang, Chuan, et al.
(författare)
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Research development on utilizing biomass in the blast furnace for CO2 emission reduction : Experiences from Nordic countries and Canada
- 2018
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Ingår i: 8th International Congress on Science and Technology of Ironmaking - ICSTI 2018. - : 8th International Congress on the Science and Technology of Ironmaking.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Within the integrated steel plant, the blast furnace BF is the most energy intensive process with significant amount of CO2 emission. Switching of fossil fuels to biomass offers an alternative for the natural resources reservation and climate change mitigation. In recent years, lots of efforts have been putting on developing biomass for BF’s utilization, especially in regions with abundant forest resources. This paper aims to give a review of research development in Sweden and Finland from North Europe and Canada from North America. Biomass availability, market competition, economic feasibility, and barriers and challenges for the industrial applications are addressed.
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