| 1. |
- 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/konstnärligt)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-firedconditions. Measurements have been carried out in a 100 kW test unit, which facilitates oxy-fuelcombustion with real flue gas recycle. These measurements include in-furnace gas concentrations andtemperature 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-fuelexperiments were performed in order to study the sensitivity of the NO formation to bothstoichiometry and air ingress.The results show that for the burner settings used in this work, lignite oxy-combustion with a globaloxygen fraction of 25 vol % in the feed gas results in flame temperature levels close to those duringair-firing. Similar to previous work, it is seen that the NO emission levels in [mg/MJ] during oxy-fueloperation are reduced to less than 30 % of the emission level during air-fired conditions. The resultsfrom the modeling shows that the reduction of NO emissions during oxy-fuel combustion is caused byan increased destruction of formed and recycled NO. Further experimental tests on the OF 27condition show that an increased stoichiometric ratio (from l = 1.18 to 1.41) as well as an increasedN2 content in the feed gas (from about 1% to 15%) only has a small effect on the NO formation duringoxy-combustion.
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| 2. |
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| 3. |
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| 4. |
- 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. - 9783180920566 ; 2056:24. Deutscher Flammentag, s. 289-294
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Fleig, Daniel, 1980, et al.
(författare)
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The fate of sulphur during oxy-fuel combustion of lignite
- 2009
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 1:1, s. 383-390
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work focuses on the sulphur chemistry in oxy-fuel combustion of lignite. Comparison is made with air-fired conditions, and the main combustion products containing sulphur (ash, SO2, SO3 and H2S) are examined by modelling and experimental data. The conversion of fuel-S to SO2 is lower in oxy-fuel than in air-fuel conditions and the SO2 concentration per unit energy supplied is therefore reduced. The modelling shows that the SO3 concentration is about four times greater than the concentration in air-firing. High SO3 and H2O contents in the oxy-fuel flue gas during wet recycling increase the acid dew-point by 20 to 30 K.
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| 6. |
- Fleig, Daniel, 1980, et al.
(författare)
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The Sulphur Mass Balance in Oxy-Fuel Combustion of Lignite
- 2009
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Ingår i: 1st OXYFUEL COMBUSTION CONFERENCE: September 8-11, 2009, Cottbus, Germany.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work presents an experimental study of the sulphur chemistry in oxy-fuel combustion of pulverized lignite. It has been observed that the emission of sulphur dioxide (SO2) by unit energy supplied is lower in oxy-fuel combustion than in air combustion [1-5] but the reason for this is not clear. In order to validate previous work and to clarify this difference the present work compares the amount of emitted SO2 in air and oxy-fuel combustion (wet and dry flue-gas recycle). Furthermore, the amounts of sulphur in the ash and in the water of the flue-gas condenser were determined to make a mass balance and to verify the measured amount of SO2 in the flue gas.
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| 7. |
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| 8. |
- Normann, Fredrik, 1982, et al.
(författare)
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CO-COMBUSTION IN AN OXYFUEL POWER PLANT WITH SYNTHESIS GAS PRODUCTION
- 2007
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Ingår i: Proceedings of the 15th European Biomass Conference & Exhibition - From research to market Deployment, Berlin, Germany, 7-11 May 2007.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper investigates new possibilities and synergy effects for co-firing of biomass and coal in an energy system with carbon capture. A new way to make the oxyfuel process more effective through a sub stoichiometric combustion is enabled due to the co-combustion of biomass in the process, which keeps the process CO2 neutral. The sub stoichiometric combustion leads to a production of synthesis gas in the process, which is converted to DME in an integrated process. An available study on an oxyfuel power plant is combined with a process for DME production in a computer model to simulate the suggested process. The degree of sub stoichiometric combustion, or amount of synthesis gas produced, is optimized with respect to the overall efficiency. The maximal efficiency were found at a stoichiometric ratio of 0.6 were the efficiency for the electricity producing oxyfuel process is 0.35 and the efficiency for the DME process is 0.65. The results show how biomass can improve carbon capture processes and on a possibility for an expansion and an efficient use of biomass.
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| 9. |
- Normann, Fredrik, 1982, et al.
(författare)
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Emission control of nitrogen oxides in the oxy-fuel process
- 2009
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Ingår i: Progress in Energy and Combustion Science. - : Elsevier BV. - 0360-1285. ; 35:5, s. 385-397
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Tidskriftsartikel (refereegranskat)abstract
- The interest in oxy-combustion as a method to capture carbon dioxide has increased drastically during recent years. The oxy-fuel process offers new process conditions and may take advantage of innovative techniques as well as of new ways to apply conventional measures for emission control. The present work reviews available techniques for controlling both the emission of nitrogen oxides (NOx) to the atmosphere and the content of NOx in the captured carbon dioxide. The results indicate that for a first generation of oxy-fuel power plants, conventional primary NOx control should be sufficient to meet today's emission regulations, if based on emission per unit of fuel supplied. However, there are several opportunities for new methods of NOx control in oxy-fuel plants, depending on future emission and storage legislation for carbon capture schemes. Improved understanding of the behaviour of nitric oxide and nitrogen dioxide during compression and condensation of carbon dioxide is needed, as well as improved knowledge on the influence of the parameters of oxy-combustion on nitrogen chemistry.
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