Conference Dates

May 1-5, 2011


A dual fluidized bed process using CaO-based solid sorbent is considered to be a promising technology to separate CO2 from flue gas with low energy penalty. As reactor for CaO-looping cycle, both bubbling fluidized bed and “fast” fluidized bed are available, thus four possible combinations, (bubbling or fast absorber)x(bubbling or fast regenerator), are conceivable for this process. In this work, the authors discuss favorable combination of reactor type from viewpoints of heat removal from carbonation reactor and on energy penalty associated with dilution of pure oxygen by CO2 in the regenerator. As conclusion, suitable combination was found to be bubbling bed absorber and fast regenerator. Design of bench-scale experimental apparatus of the present system was also carried out. Bubbling bed absorber was designed to achieve 86 % CO2 removal efficiency from flue gas. Preliminary operating results of solid circulation at room temperature are also presented.