Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
CO2 capture from oxy-fuel combustion power plants
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

To mitigate the global greenhouse gases (GHGs) emissions, carbon dioxide (CO2) capture and storage (CCS) has the potential to play a significant role for reaching mitigation target. Oxy-fuel combustion is a promising technology for CO2 capture in power plants. Advantages compared to CCS with the conventional combustion technology are: high combustion efficiency, flue gas volume reduction, low fuel consumption, near zero CO2 emission, and less nitrogen oxides (NOx) formation can be reached simultaneously by using the oxy-fuel combustion technology. However, knowledge gaps relating to large scale coal based and natural gas based power plants with CO2 capture still exist, such as combustors and boilers operating at higher temperatures and design of CO2 turbines and compressors. To apply the oxy-fuel combustion technology on power plants, much work is focused on the fundamental and feasibility study regarding combustion characterization, process and system analysis, and economic evaluation etc. Further studies from system perspective point of view are highlighted, such as the impact of operating conditions on system performance and on advanced cycle integrated with oxy-fuel combustion for CO2 capture.

In this thesis, the characterization for flue gas recycle (FGR) was theoretically derived based on mass balance of combustion reactions, and system modeling was conducted by using a process simulator, Aspen Plus. Important parameters such as FGR rate and ratio, flue gas composition, and electrical efficiency etc. were analyzed and discussed based on different operational conditions. An advanced evaporative gas turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture was also studied. Based on economic indicators such as specific investment cost (SIC), cost of electricity (COE), and cost of CO2avoidance (COA), economic performance was evaluated and compared among various system configurations. The system configurations include an EvGT cycle power plant without CO2 capture, an EvGT cycle power plant with chemical absorption for CO2 capture, and a combined cycle power plant.

The study shows that FGR ratio is of importance, which has impact not only on heat transfer but also on mass transfer in the oxy-coal combustion process. Significant reduction in the amount of flue gas can be achieved due to the flue gas recycling, particularly for the system with more prior upstream recycle options. Although the recycle options have almost no effect on FGR ratio, flue gas flow rate, and system electrical efficiency, FGR options have significant effects on flue gas compositions, especially the concentrations of CO2 and H2O, and heat exchanger duties. In addition, oxygen purity and water/gas ratio, respectively, have an optimum value for an EvGT cycle power plant with oxy-fuel combustion. Oxygen purity of 97 mol% and water/gas ratio of 0.133 can be considered as the optimum values for the studied system. For optional operating conditions of flue gas recycling, the exhaust gas recycled after condensing (dry recycle) results in about 5 percentage points higher electrical efficiency and about 45 % more cooling water consumption comparing with the exhaust gas recycled before condensing (wet recycle). The direct costs of EvGT cycle with oxy-fuel combustion are a little higher than the direct costs of EvGT cycle with chemical absorption. However, as plant size is larger than 60 MW, even though the EvGT cycle with oxy-fuel combustion has a higher COE than the EvGT cycle with chemical absorption, the EvGT cycle with oxy-fuel combustion has a lower COA. Further, compared with others studies of natural gas combined cycle (NGCC), the EvGT system has a lower COE and COA than the NGCC system no matter which CO2 capture technology is integrated. 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2011. , xiv, 42 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2011:52
Keyword [en]
CO2 capture, oxy-fuel combustion, flue gas recycle, evaporative gas turbine, techno- economic evaluation
National Category
Energy Engineering
Identifiers
URN: urn:nbn:se:kth:diva-48666ISBN: 978-91-7501-140-0 (print)OAI: oai:DiVA.org:kth-48666DiVA: diva2:458304
Presentation
2011-11-29, K1, KTH, Teknikringen 56, Stockholm, 13:00 (English)
Opponent
Supervisors
Note
QC 20111123Available from: 2011-11-23 Created: 2011-11-22 Last updated: 2011-11-23Bibliographically approved
List of papers
1. Characterization of flue gas in oxy-coal combustion processes for CO2 capture
Open this publication in new window or tab >>Characterization of flue gas in oxy-coal combustion processes for CO2 capture
2012 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 90, no 1, 113-121 p.Article in journal (Refereed) Published
Abstract [en]

Oxy-coal combustion is one of the technical solutions for mitigating CO2 in thermal power plants. For designing a technically viable and economically effective CO2 capture process, effects by coals and configurations of flue gas cleaning steps are of importance. In this paper, characterization of the flue gas recycle (FGR) is conducted for an oxy-coal combustion process. Different configurations of FGR as well as cleaning units including electrostatic precipitators (ESP), flue gas desulfurization (FGD), selective catalytic reduction (SCR) deNOx and flue gas condensation (FGC) are studied for the oxy-coal combustion process. In addition, other important parameters such as FGR rate and FGR ratio, flue gas compositions, and load of flue gas cleaning units are analyzed based on coal properties and plant operational conditions.

Place, publisher, year, edition, pages
Elsevier, 2012
Keyword
Oxy-coal combustion; Mass balance; CO2 capture; Flue gas cleaning
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-48631 (URN)10.1016/j.apenergy.2011.03.005 (DOI)000297426100018 ()2-s2.0-80055036207 (Scopus ID)
Note
QC 20111122, QC 20120109Available from: 2011-11-22 Created: 2011-11-22 Last updated: 2017-12-08Bibliographically approved
2. Effects of flue gas recycle on the performance of particles, SOx and NOx removal in oxy-coal power generation system
Open this publication in new window or tab >>Effects of flue gas recycle on the performance of particles, SOx and NOx removal in oxy-coal power generation system
2011 (English)In: Third International Conference on Applied Energy, 16-18 May 2011, Perugia, Italy., 2011, 841-852 p.Conference paper, Published paper (Refereed)
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-48641 (URN)
Conference
Third International Conference on Applied Energy
Note
QC 20111123Available from: 2011-11-23 Created: 2011-11-22 Last updated: 2011-11-23Bibliographically approved
3. Integration of Evaporative Gas Turbine with Oxy-Fuel Combustion for Carbon Dioxide Capture
Open this publication in new window or tab >>Integration of Evaporative Gas Turbine with Oxy-Fuel Combustion for Carbon Dioxide Capture
2010 (English)In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 7, no 6, 615-631 p.Article in journal (Refereed) Published
Abstract [en]

This paper studied the integration of Evaporative Gas Turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture. The impact of key parameters on system electrical efficiency, such as the oxygen purity, Water/Gas ratio (W/G) has been investigated concerning thermal efficiency. The performance of dry recycle and wet recycle also has be analyzed and compared. Simulation results shows that: (1) 97% can be considered as the optimum oxygen purity taking into account the trade-off between the air separation unit (ASU) consumption penalty of producing higher-purity oxygen and electrical efficiency; (2) there" exists an optimum point of W/G for both EvGT and EvGT combined with oxy-fuel combustion CO2 capture technology; (3) dry recycle has a" considerably higher electrical efficiency comparing with wet recycle, but more cooled water can be saved in the wet recycle. The performance of EvGT cycle was also compared to the combined cycle (CC) when CO2 capture was considered. The comparison shows that CC has a higher net power output and electrical efficiency than the EvGT cycle no matter if combined with oxy-fuel combustion CO2 capture technology or not.

Keyword
Evaporative gas turbine, Humid air turbines, CO2 capture, Oxy-fuel combustion, Electrical efficiency
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-28907 (URN)10.1080/15435075.2010.529405 (DOI)000285198400004 ()2-s2.0-78650217949 (Scopus ID)
Note
QC 20110501Available from: 2011-05-02 Created: 2011-01-24 Last updated: 2017-12-11Bibliographically approved
4.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.

Open Access in DiVA

fulltext(1397 kB)6394 downloads
File information
File name FULLTEXT01.pdfFile size 1397 kBChecksum SHA-512
9823d96548ccebd08e57cc219af0d16241d4cd4f524107c85b0e6671b80cd61197d67d91d3fe6d4f21662b92b7758159e73c974fb4cd70a81404a3eff56c9e83
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Hu, Yukun
By organisation
Energy Processes
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 6394 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 537 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf