The awareness of the increase in greenhouse gas emissions has resulted in the development of new technologies with lower emissions & technologies that can accommodate capture & sequestration of carbon dioxide. For existing coal-fired combustion plants, there are two main options for CO2 capture: removal of nitrogen from flue gases or removal of nitrogen from air before combustion to obtain a gas stream ready for geo-sequestration. In oxy-fuel combustion, fuel is combusted in pure oxygen rather than air. This technology recycles flue gas back into the furnace to control temperature & makeup the volume of the missing N2 to ensure there is sufficient gas to maintain the temperature & heat flux profiles in the boiler. A further advantage of the technology revealed in pilot-scale tests is substantially reduced NOx emissions. This paper reviews the research.
