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- Andersson, Klas, 1977-, et al.
(författare)
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Experiments and modeling on oxy-fuel combustion chemistry during lignite-firing
- 2007
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Ingår i: The Proceedings of the 32nd International Technical Conference on Coal Utilization & Fuel Systems, Clearwater, USA, 2007.
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Konferensbidrag (övrigt vetenskapligt)abstract
- This paper presents experimental and modeling work on the combustion chemistry of the oxy-fuel (O2/CO2 recycle) process with focus on the difference in NO formation between oxy-fuel and air-fired conditions. Measurements have been carried out in a 100 kW test unit, which facilitates oxy-fuel combustion with real flue gas recycle. These measurements include in-furnace gas concentrations and temperature profiles from lignite-fired tests. The tests comprise a reference test in air and three oxy- fuel test cases with different oxygen fractions in the recycled feed gas. Additional oxy-fuel experiments were performed in order to study the sensitivity of the NO formation to both stoichiometry and air ingress. The results show that for the burner settings used in this work, lignite oxy-combustion with a global oxygen fraction of 25 vol % in the feed gas results in flame temperature levels close to those during air-firing. Similar to previous work, it is seen that the NO emission levels in [mg/MJ] during oxy-fuel operation are reduced to less than 30 % of the emission level during air-fired conditions. The results from the modeling shows that the reduction of NO emissions during oxy-fuel combustion is caused by an increased destruction of formed and recycled NO. Further experimental tests on the OF 27 condition show that an increased stoichiometric ratio (from l = 1.18 to 1.41) as well as an increased N2 content in the feed gas (from about 1% to 15%) only has a small effect on the NO formation during oxy-combustion.
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| 7. |
- Berntsson, Thore, 1947-, et al.
(författare)
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Towards Sustainabel Oil Refinery - Pre-study for larger co-operation project
- 2008
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Rapport (övrigt vetenskapligt)abstract
- In this report, the Chalmers EnergiCentrum (CEC) presents the results of a pre-study commissioned by Preem relating to the effective production of future vehicle fuels. This pre-study was made up of three studies focusing on energy streamlining, the utilisation of waste heat and carbon-dioxide separation and biorefinement relating to the gasification and hydration of vegetable oils. One of the common starting points for these studies was the current situation at the Preem refineries in Göteborg and Lysekil from where the measurement data were obtained and analysed. The report summarises the knowledge situation based on current research in the individual technical fields. The results present some interesting future opportunities for developing the sustainable production of future vehicle fuels. The sections vary, as the areas that have been examined differ and the sections have been written by different people. The reports ends with some joint conclusions and a number of questions which could be included and answered in a more extensive future main study, as part of a developed research partnership between Preem and the Chalmers University of Technology. The preliminary results of this work were analysed with the client at workshops on 1 October and 29 November 2007. The report is written in English combined with an extensive summary in Swedish including a proposal on a future main study. The study was conducted by the Chalmers EnergiCentrum (CEC), in collaboration with a number of researchers in the CEC’s network. They included Thore Berntsson, Jessica Algehed, Erik Hektor and Lennart Persson Elmeroth, all from Heat and Power Technology, Börje Gevert, Chemical and Biological Engineering, Tobias Richards, Forest Products and Chemical Engineering, Filip Johnsson and Anders Lyngfelt, Energy Technology, and Per-Åke Franck and Anders Åsblad, CIT Industriell Energianalys AB. The client, Preem, was represented by Bengt Ahlén, Sören Eriksson, Johan Jervehed, Bertil Karlsson, Gunnar Olsson, Ulf Kuylenstierna, Stefan Nyström, Martin Sjöberg and Thomas Ögren. Tobias Richards was responsible for compiling the report and Bertil Pettersson was the project manager.
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| 8. |
- Bäckström, Daniel, 1985-, et al.
(författare)
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Gas temperature and radiative heat transfer in oxy-fuel flames
- 2012
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Ingår i: The 37th International Technical Conference on Clean Coal & Fuel Systems, Clearwater USA, 3-7/6-2012. - 978-0-932066-37-4
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Konferensbidrag (övrigt vetenskapligt)abstract
- This work presents measurements of the gas temperature, including fluctuations, and its influence on the radiative heat transfer in oxy-fuel flames. The measurements were carried out in the Chalmers 100 kW oxy-fuel test unit. The in-furnace gas temperature was measured by a suction pyrometer and by an optical system based on FTIR-spectroscopy. The radiation intensity was measured by a Narrow Angle Radiometer and the gas radiation was calculated with a Statistical Narrow Band model. The overall agreement between the two temperature measurement techniques was good. The optical system showed a lower temperature than the suction pyrometer in the low velocity regions of the furnace, a difference which is likely to be an effect of the purge gas added in the optical probe. The measured temperature fluctuations were evaluated by modeling of the gas radiation. The influence from the measured fluctuations on the radiative heat transfer shows no effect of turbulence-radiation interaction. However, by comparing with temperature fluctuations in other flames it can be seen that the fluctuations measured here are relatively small. Further research is needed to clarify to which extent the applied methods can account for the turbulence-radiation interaction in the investigated flame.
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| 9. |
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European Energy Pathways - Pathways to sustainable european energy systems
- 2011
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Samlingsverk (redaktörskap) (övrigt vetenskapligt)abstract
- To meet the challenge of climate change, the world must substaintially reduce emissions of greenhouse gases (GHGs). this must be accomplished in a way that maintains security of supply and competitiveness. This book presents to pathways towards sustainable European energy systems - the "Policy Pathway" and the "Market Pathway". These to pathways differ with respect to where the main responsability lies for transforming the energy system in following the pathway. The Policy pathway takes its departure from the EU Energy and Climate Package, and has a strong focus on targeted policies that promote energy efficiency and energy from renewable sources. The Market Pathway relies more on the market to transform the energy system, and presents a future in which the cost associated with emitting CO2 (and other GHGs) is the dominating policy measure. This book describes the research that has been carried out during the first period (2006-2010) of the AGS project "Pathways to Sustsainable Energy Systems". This interdisciplinary project involved more than 40 researchers and addressed various aspects of the challenges faced in transforming the European energy system. The chapters in this book cover more than 30 topics and presents an overall picture of the results obtained to date from various activities in the Pathways project.
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- Fleig, Daniel, 1980-, et al.
(författare)
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Sulphur chemistry in oxy-fuel combustion
- 2009
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Ingår i: VDI-Berichte. - 0083-5560. - 978-3-18-092056-6 ; 2056:24. Deutscher Flammentag, s. 289-294
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Konferensbidrag (övrigt vetenskapligt)
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