In order to generate pure streams of CO2 suitable for sequestration/storage, various routes are possible, involving pre-combustion strategies such as the use of gasification technology combined with shift reactors to produce H2 or alternatively CO2 scrubbing with, for example, amine-based carriers. One of the more direct approaches is to carry out the combustion using pure or nearly pure O2 to produce primarily CO2 and H2O in the combustion gases, resulting in almost complete CO2 capture. Until recently, the primary avenue to deploy this technology was with conventional pulverized fuel-fired boilers, and there have been a number of demonstration plants built to explore this technology. In addition, oxy-fired fluidized bed combustion (FBC) has also become increasingly important as a potential technology, offering as it does fuel flexibility and the possibility of firing local or indigenous fuels, including biomass in a CO2-neutral or CO2-negative manner. There are also attempts to develop pressurized oxy-fuel technology for both PC and FBC systems. These technologies are examined here, considering factors such as their economics and potential for improvement, as well as challenges to the technology, including the need to generate high-purity CO2 streams suitable for pipelining to sequestration sites. Finally, the emissions issues for both classes of technology are discussed.