526 research outputs found
Ligniinipohjaisen biohiilen käyttö metallurgisissa sovelluksissa
No full textAbstractPyrometallurgical processes in the iron and steel industry are energy intensive. Therefore, sustainability in terms of CO2 emissions is highly dependent on the choice of fuel. Large quantities of carbon are used in pyrometallurgical processes, for example in slag foaming, iron oxide reduction or as an alloying element. Currently, the majority of the used carbon originates from fossil sources.The most important properties that are generally required from carbonaceous materials in pyrometallurgical applications are mechanical strength, sufficient apparent density and suitable reactivity. The properties of industrially produced metallurgical coke works as a great reference for evaluation of these properties, since metallurgical coke is used in multiple pyrometallurgical applications in different forms: coke dust is used as a foaming agent and carburiser in the electric arc furnace (EAF) process, and coke lumps are used as a reducing agent and structural bed material in the blast furnace (BF) process and as a reducing agent in submerged arc furnace (SAF) process.This thesis focuses on the utilisation of hydrolysis lignin as a raw material for the production of biocarbon that could be utilised as a carbonaceous material in pyrometallurgical applications to substitute fossil-based carbon. Based on the results of this thesis, it was discovered that the structure of lignin-based biocarbon can be modified using the chosen treatment methods, briquetting and high pyrolysis temperature. With these treatment methods, the important properties (mechanical strength, apparent density and reactivity) were improved and modified, with the compressive strength property of biocarbon even surpassing that of metallurgical coke.Original papersOriginal papers are not included in the electronic version of the dissertation.Koskela, A., Suopajärvi, H., Mattila, O., Uusitalo, J., & Fabritius, T. (2019). Lignin from bioethanol production as a part of a raw material blend of a metallurgical coke. Energies, 12(8), 1533. https://doi.org/10.3390/en12081533Self-archived versionKoskela, A., Heikkilä, A., Bergna, D., Salminen, J., & Fabritius, T. (2021). Effects of briquetting and high pyrolysis temperature on hydrolysis lignin char properties and reactivity in CO-CO2-N2 conditions. Minerals, 11(2), 187. https://doi.org/10.3390/min11020187Self-archived versionKoskela, A., Suopajärvi, H., & Fabritius, T. (2022). Interaction between coal and lignin briquettes in co-carbonization. Fuel, 324, 124823. https://doi.org/10.1016/j.fuel.2022.124823Self-archived versionKoskela, A., Suopajärvi, H., Uusitalo, J., & Fabritius, T. (2023). Evolution of biocarbon strength and structure during gasification in CO2 containing gas atmosphere. Fuel Communications, 14, 100082. https://doi.org/10.1016/j.jfueco.2022.100082Self-archived versionTiivistelmäTerästeollisuuden pyrometallurgiset prosessit ovat energiaintensiivisiä. Sen vuoksi terästeollisuuden ekologisuus CO2 päästöjen osalta on erittäin riippuvainen polttoainevalinnasta. Suuria määriä hiiltä käytetään pyrometallurgisissa prosesseissa, esimerkiksi kuonan kuohutuksessa, raudan oksidien pelkistyksessä tai seosaineena. Nykyään suurin osa käytetystä hiilestä on lähtöisin fossiilisista lähteistä.Pyrometallurgisissa prosesseissa käytettäviltä hiilimateriaaleilta vaadittuja tärkeimpiä ominaisuuksia ovat mekaaninen lujuus, riittävä näennäistiheys ja sopiva reaktiivisuus. Teollisesti valmistetun metallurgisen koksin ominaisuudet sopivat hyvin näiden ominaisuuksien vertailukohdaksi, sillä koksia käytetään useissa eri sovelluksissa eri muodoissa: koksipölyä käytetään kuonan kuohutusaineena ja hiilen tuojana valokaariuuniprosessissa, palakoksia pelkistimenä ja rakenteellisena petimateriaalina masuunissa sekä pelkistimenä uppokaariuunissa.Tämä työ keskittyy hydrolyysiligniinin hyötykäyttöön raaka-aineena biohiilen ja biokoksin valmistuksessa, joita voidaan käyttää hiilen tuojana pyrometallurgisissa sovelluksissa korvaamaan fossiilista lähteistä tuotettua hiiltä. Tämän työn tulosten perusteella hydrolyysiligniini-pohjaisen biohiilen rakennetta pystyttiin muokkaamaan valituilla käsittelymenetelmillä, briketoinnilla ja korkealla pyrolyysilämpötilalla. Näillä menetelmillä biohiilen tärkeitä ominaisuuksia (mekaaninen lujuus, näennäistiheys ja reaktiivisuus) saatiin parannettua siten, että biohiilen puristuslujuus oli jopa suurempi kuin metallurgisella koksilla.OsajulkaisutOsajulkaisut eivät sisälly väitöskirjan elektroniseen versioon.Koskela, A., Suopajärvi, H., Mattila, O., Uusitalo, J., & Fabritius, T. (2019). Lignin from bioethanol production as a part of a raw material blend of a metallurgical coke. Energies, 12(8), 1533. https://doi.org/10.3390/en12081533Rinnakkaistallennettu versioKoskela, A., Heikkilä, A., Bergna, D., Salminen, J., & Fabritius, T. (2021). Effects of briquetting and high pyrolysis temperature on hydrolysis lignin char properties and reactivity in CO-CO2-N2 conditions. Minerals, 11(2), 187. https://doi.org/10.3390/min11020187Rinnakkaistallennettu versioKoskela, A., Suopajärvi, H., & Fabritius, T. (2022). Interaction between coal and lignin briquettes in co-carbonization. Fuel, 324, 124823. https://doi.org/10.1016/j.fuel.2022.124823Rinnakkaistallennettu versioKoskela, A., Suopajärvi, H., Uusitalo, J., & Fabritius, T. (2023). Evolution of biocarbon strength and structure during gasification in CO2 containing gas atmosphere. Fuel Communications, 14, 100082. https://doi.org/10.1016/j.jfueco.2022.100082Rinnakkaistallennettu versioAcademic dissertation to be presented with the assent of the Doctoral Programme Committee of Technology and Natural Sciences of the University of Oulu for public defence in the OP auditorium (L10), Linnanmaa, on 12 May 2023, at 12 noonAbstract
Pyrometallurgical processes in the iron and steel industry are energy intensive. Therefore, sustainability in terms of CO2 emissions is highly dependent on the choice of fuel. Large quantities of carbon are used in pyrometallurgical processes, for example in slag foaming, iron oxide reduction or as an alloying element. Currently, the majority of the used carbon originates from fossil sources.
The most important properties that are generally required from carbonaceous materials in pyrometallurgical applications are mechanical strength, sufficient apparent density and suitable reactivity. The properties of industrially produced metallurgical coke works as a great reference for evaluation of these properties, since metallurgical coke is used in multiple pyrometallurgical applications in different forms: coke dust is used as a foaming agent and carburiser in the electric arc furnace (EAF) process, and coke lumps are used as a reducing agent and structural bed material in the blast furnace (BF) process and as a reducing agent in submerged arc furnace (SAF) process.
This thesis focuses on the utilisation of hydrolysis lignin as a raw material for the production of biocarbon that could be utilised as a carbonaceous material in pyrometallurgical applications to substitute fossil-based carbon. Based on the results of this thesis, it was discovered that the structure of lignin-based biocarbon can be modified using the chosen treatment methods, briquetting and high pyrolysis temperature. With these treatment methods, the important properties (mechanical strength, apparent density and reactivity) were improved and modified, with the compressive strength property of biocarbon even surpassing that of metallurgical coke.Tiivistelmä
Terästeollisuuden pyrometallurgiset prosessit ovat energiaintensiivisiä. Sen vuoksi terästeollisuuden ekologisuus CO2 päästöjen osalta on erittäin riippuvainen polttoainevalinnasta. Suuria määriä hiiltä käytetään pyrometallurgisissa prosesseissa, esimerkiksi kuonan kuohutuksessa, raudan oksidien pelkistyksessä tai seosaineena. Nykyään suurin osa käytetystä hiilestä on lähtöisin fossiilisista lähteistä.
Pyrometallurgisissa prosesseissa käytettäviltä hiilimateriaaleilta vaadittuja tärkeimpiä ominaisuuksia ovat mekaaninen lujuus, riittävä näennäistiheys ja sopiva reaktiivisuus. Teollisesti valmistetun metallurgisen koksin ominaisuudet sopivat hyvin näiden ominaisuuksien vertailukohdaksi, sillä koksia käytetään useissa eri sovelluksissa eri muodoissa: koksipölyä käytetään kuonan kuohutusaineena ja hiilen tuojana valokaariuuniprosessissa, palakoksia pelkistimenä ja rakenteellisena petimateriaalina masuunissa sekä pelkistimenä uppokaariuunissa.
Tämä työ keskittyy hydrolyysiligniinin hyötykäyttöön raaka-aineena biohiilen ja biokoksin valmistuksessa, joita voidaan käyttää hiilen tuojana pyrometallurgisissa sovelluksissa korvaamaan fossiilista lähteistä tuotettua hiiltä. Tämän työn tulosten perusteella hydrolyysiligniini-pohjaisen biohiilen rakennetta pystyttiin muokkaamaan valituilla käsittelymenetelmillä, briketoinnilla ja korkealla pyrolyysilämpötilalla. Näillä menetelmillä biohiilen tärkeitä ominaisuuksia (mekaaninen lujuus, näennäistiheys ja reaktiivisuus) saatiin parannettua siten, että biohiilen puristuslujuus oli jopa suurempi kuin metallurgisella koksilla
Reduction of iron ore burden materials mixed with nut coke under simulated blast furnace conditions
No full textModern blast furnace ironmaking technology: potentials to meet the demand of high hot metal production and lower energy consumption
No full textIron and steel making is one of the most intense energy consuming in the industrial sectors. The intensive utilization of fossil carbon in the ironmaking blast furnace (BF) is related directly to CO2 emission and global warming. Lowering the energy consumption and CO2 emission from BF comes on the top priorities from both economic and environmental aspects. The BF has undergone tremendous modifications and development to increase production and improve the overall efficiency. Both technological development and scientific research drive one another to reach optimum operation conditions, which are very close to the ideal conditions; however, further development is still required to meet the stringent environmental regulations. The present article provides a comprehensive review of recent research and development which were carried out in modern blast furnace to increase the productivity meanwhile reduce the energy consumption and CO2 emission to meet the demand of steel market and the environmental protection. The recent technological and metallurgical improvements in the BF are intensively discussed including: (i) modifications of BF design, top charging and measuring system, (ii) upgrading of conventional top charging burden and alternative agglomerates, (iii) developing of tuyeres injection system and injected materials, and (iv) potentials of waste heat recovery and usage. These topics are reviewed and discussed in some details to elucidate the potential of recent progress in BF technology in saving the energy consumption and lowering CO2 emission. In this paper, the major research and development which have been carried out in ironmaking BF technology are reviewed with an overview of the future prospects
Reduction of iron ore burden materials mixed with nut coke under simulated blast furnace conditions
No full textMathematical Analysis of the Reduction of Wüstite at Different Basicity Using Factorial Design
No full textCorrection: Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa
No full textThe authors of the article ‘Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa’ [1] wish to acknowledge the contribution of Professor Hussein El Fishawy. Our guidelines drew on various sources, including the Egyptian Ministry of Health guidelines, portions of which were adapted and reproduced with permission from the Egyptian Ministry of Health. Two of the authors of those guidelines, Professors Elsayed and Zaki, are also coauthors of our paper. Professor El Fishawy was the third author of the Egyptian guidelines and we would like to acknowledge his contribution to our review through this source, especially with respect to the treatment algorithms for patients with kidney transplants and those with acute kidney injury. Reference1. Elsayed HM, Wadee S, Zaki MS, Were AJO, Ashuntantang GE, Bamgboye EL, et al. Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa. Afr J Nephrol. 2020; 23(1):109-126
Représentations littéraires du sacré dans le roman maghrébin de langue française
No full textThis interdisciplinary study explores how Driss Chraïbi’s L’Homme du Livre (1995), Assia Djebar’s Loin de Médine (1991), and Anissa Boumediène’s La fin d’un monde (1991) present accounts of particular historical moments in early Islam. This study explores the role of the imagination as well as freedom of invention when reconstructing historical events. It engages the novels through a study of the interplay between the literary text and the sources and traditions that impact and shape the text narrative. Gaining direct access to the original sources in Arabic serves to analyze how religious and early historical materials are considered in and reflected by the fictional texts. Because the sources tend to differ in both content and approach, this study examines their preoccupations in order to determine the criteria of selection applied by each novelist.Ph.D.Includes bibliographical referencesIncludes vitaby Hanan Elsaye
Intrathecal Drug Delivery Systems Survey: Trends in Utilization in Pain Practice [Corrigendum]
No full textAbd-Sayed A, Fiala K, Weisbein J, et al. J Pain Res. 2022;15:1305–1314.
The authors have advised there is an error in the author list on page 1305. The author name “Alaa Abd-Sayed” should read “Alaa Abd-Elsayed”.
The authors apologize for this error
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