Energy & Fuels, Vol.27, No.1, 2-19, 2013
Recent Development in Oxy-Combustion Technology and Its Applications to Gas Turbine Combustors and ITM Reactors
For decreasing greenhouse gas (mainly CO2) emissions, several approaches have been evaluated and reviewed for capturing CO2 in the utility industry, namely, carbon capture and storage technology (CCS), including precombustion capture, oxy-fuel combustion, and postcombustion capture. As a promising CCS technology, oxy-fuel combustion can be used to existing and new power plants. In oxy-combustion, a fuel is oxidized in a nearly nitrogen-free, diluted mixture such that the products consist mainly of CO2 and water vapor, enabling a relatively simple and inexpensive condensation separation process, and then, CO2 could be captured easily. There are two main approaches available to utilize the oxy-combustion technology, one of them is through the use of air separation units to separate O-2, which will be used in the combustion process, and the other application is the ion transport membrane (ITM) reactor technology. This membrane separates oxygen from oxygen containing upstream (typically air). The oxygen transports through the membrane to a downstream permeate side containing fuel, with CO2 as inert carrier gas and the combustion starts in the permeate side of the membrane. In the present review paper, the oxy-fuel combustion technology status for clean power generation and carbon capture is introduced, starting with the available carbon capture technologies and comparison between them. This is followed by a detailed review of research work that considers the oxy-fuel combustion process itself, with a particular focus on the applications to this technology in ITM reactors and gas turbine combustors. This work also presents a detailed analysis for the most recent advancement in the ITM reactors technology with more analysis related to the membrane separation mechanism, the available permeation equations in the literature and the membrane performance regarding separation only and ITM reactor applications. The new coefficients oxygen permeation equation model is introduced in this work by fitting the experimental data available in the literature for a LSCF-1991 ion transport membrane. Because of new challenges presented by oxy-fuel combustion, as opposed to air-fuel combustion, research pertaining to the analysis of oxy-fuel combustion in real systems such as gas turbines is also discussed in the present work.