CO 2 Capture by Oxyfuel Combustion

This chapter presents detailed description of oxyfuel combustion plant configuration, discusses specific features and differences between oxyfuel combustion and air combustion, and shows detailed numerical approach for establishing material balance of the oxyfuel combustion process. This numerical approach includes calculation of fluidization medium flow for the case of fluidized bed combustor. Based on experimental data, validation of the model is provided. The text discusses oxyfuel combustion in a fluidized bed, which is generally more complicated, especially by the need to maintain proper fluidization conditions. A practical example of a change of the operation mode from air to oxyfuel in a fluidized bed combustor is presented. Last part of the chapter is dedicated to discussing the formation discussion of particular pollutants that need to be removed from the off-gas before the condensation of water vapor to obtain the final CO2 can be performed. The discussion concerns differences in processes of formation and possibilities of reduction of carbon monoxide, sulfur, and nitrogen oxides that must be absent in the final CO2 due to the risk of liquid acids formation which can take place under high pressure.