Abstract:
Carbon capture and sequestration (CCS) is gaining popularity to mitigate the CO2 emission and greenhouse gases. The oxy-fuel circulating fluidized bed (CFB) combustion is one of the most promised techniques of CCS, where CFB has advantages over the pulverized coal power combustors namely, in situ SOx and NOx capture as well as fuel flexibility. However, significant drop in thermal efficiency with oxy-fuel CFB combustion is reported in literature. The research and developments are continuing to overcome the high cost of implementation of oxy-fuel CFB combustion technology. There is hardly any research regarding the hydrodynamic behaviour of CFB under oxy-fuel combustion. In the present work, two CFB units (cold and hot) of identical geometry are designed and fabricated to investigate the bed hydrodynamic and combustion under oxy-fuel combustion conditions. The core of this work is to develop a novel technique for oxy-fuel CFB combustion to enhance the efficiency and eliminate the recirculation of the flue gases. The proposed method suggests controlling the combustion temperature by adjusting the stoichiometric ratio with multi-reaction stages rather than controlling the temperature by CO2 recirculation.
