Oxy-fuel firing technology for power generation

Abstract

In order to generate pure streams of CO2 suitable for sequestration/storage, various routes are possible, involving either precombustion strategies such as the use of gasification technology combined with shift reactors to produce H2 or alternatively post-combustion strategies such as CO2 scrubbing with, for example, amine-based carriers. One of the more direct approaches is to carry out the combustion in pure or nearly pure oxygen-oxy-fuel combustion to produce primarily CO2 and H2O in the combustion gases, resulting in almost complete CO2 capture. Until recently, the primary avenue for deploying this technology was with conventional pulverized fuel-fired boilers, and there is already one large demonstration plant operating in Europe with more being planned in the future. However, more recently 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 manner. Both oxy-fuel combustion technologies have been examined here, considering factors such as their economics and potential for improvement, as well as challenges to the technology, including the need to generate CO2 streams of suitable purity for pipeline transport to available sequestration sites. Finally, the emission issues for both classes of the technology are discussed.