International Oxy-Combustion Network for CO₂ Capture: Report on Inaugural Workshop

Publication Overview

The aim of this Network for Oxy-Fuel Combustion is to provide an international forum for organisations with interest in the development of Oxy-Fuel Combustion Technology.Due to the broadness of this topic, it was decided to focus the theme of the first workshop on the “Oxy-Fuel Combustion for Coal Fired Power Plant”. Nevertheless, the future workshop will also attend to the development in Oxy-Fuel Combustion for Gas Fired Power Plants and other novel oxy-combustion processes.

Publication Summary

• The workshop discussion was led by Dr. Sho Kobayashi of Praxair. Specifically, the discussionis based on the various points raised in the issue paper prepared by IEA Greenhouse Gas R&DProgramme (See Appendix 3). The discussion was focused on the following main topics:
• Various operation issues relevant to the recycled flue gas and its impact to the flameproperties.
• Availability of basic technical information required in understanding the combustioncharacteristics of the oxy-coal combustion with recycled flue gas.
• The importance of establishing baseline information for the development of a reliablemodel that could be used as tools for design and analysis of the oxy-combustion flame.
• Understanding the mechanisms of pollutant emissions from an oxy-combustion flamewhich includes for NOx, SOx, particulate matters and mercury.
• Various operational issues involving plant safety, procedural routine for starting up, turndown and shut down, and dynamics involving the integration of operating the airseparation unit, the power plant island and the CO₂ processing and compression train.During the discussion, there are several points were highlighted. A few of these issues werenoted below:
• The importance of ensuring high availability and reliability was clearly stressed duringthe discussion. Primarily, the goal of the Vattenfall’s 30 MW pilot plant project andCSEnergy’s Calide-A project is to establish a good understanding and learn thefundamental operation requirements of an oxy-coal combustion power plant to increasetheir confidence of having the desired reliability similar to current fleet of pulverised coalfired power plant.
• A discussion was on the potential benefits and possible failure of having an oxy-coalcombustion boiler operating with minimal flue gas recirculation. It was noted that therecould be a gain in terms of reduction in capital cost due to a more compact boilerhowever it was clearly stressed that this should be balanced against potential problems(ie. slagging) that may occur due to the higher temperature condition created by a higher
       o xygen concentration.
• An important point was raised with regard to regulations requirement with regard to thedispersion of the flue gas. It was clearly noted that due to lower volume and higherdensity of the flue gas, the dispersion radius could be smaller as compared to current PCboilers. This issue was raised during the discussion to highlight the importance ofknowing the minimum stack height of an oxy-combustion boiler in case whereemergency release of the flue gas is necessary.
• Another discussion was raised on the level of understanding toward processing andcompression of CO₂ with high level of impurities. It was noted that there is still asignificant gaps in knowledge with regard to the fundamental understanding of the phasediagram of CO₂ especially in the presence of other impurities.