Oxyfuel combustion for CO2 capture in power plants
Oxyfuel combustion is one of the leading technologies considered for capturing CO2 from power plants with CCS. This involves the process of burning the fuel with nearly pure oxygen instead of air. In order to control the flame temperature, some part of the flue gas are recycled back into the furnace/boiler. Since the publication of the Special Report on CO2 Capture and Storage by the International Panel for Climate Change (IPCC, 2005) the development of oxyfuel combustion technology has progressed significantly and could be considered at par in terms of technology maturity as compared to other leading CO2 capture technologies. This paper presents an overview to the current state of the art technology on the development of oxyfuel combustion applied to (a) PC and CFB coal fired power plants and (b) gas turbine based power plant. It should be noted that it is not the intention of this paper to provide a comprehensive review but to present what have been achieved in the past 10 years of RD&D efforts. For coal fired power plant using oxyfuel combustion, this paper primarily presents the different development aspects of the burners and boilers (combustion and heat transfer) emissions, operation of the plant (i.e. start up and turndown) and its integration to the ASU and CPU. For gas turbine based power plant using oxyfuel combustion, the different GT cycles are described, looking at the different aspects in combustion, emissions, cycle efficiency and development of the turbomachineries. Also presented in this paper is a snapshot to what we have learned from the operation of the different large scale pilot plants and development of large scale demonstration projects worldwide. The paper concludes by presenting the potential of this technology and highlighting the importance of realizing large scale demonstration plant as a necessary step to achieve its ultimate goal of technology commercialization.