Carbon dioxide capture using solid sorbents in a fluidized bed with reduced pressure regeneration in a downer

The most common technology for post-combustion of CO2 capture for existing power plants is the amine solvent scrubber. The energy consumption for capturing CO2 from flue gases using amine solvent technology is 15 to 30% of the power plant electricity production. Hence there is a need to develop more efficient methods of removing CO2. In this study we show a novel design, obtained using multiphase CFD, of a fluidized bed reduced pressure regenerator, coupled with a fluidized bed sorber, which has the potential to reduce the energy consumption. The undesirable core-annular flow regime in the riser-sorber is eliminated using multiple jet inlets and large particles leading to a shorter height. Up to 88% of the heat liberated in the riser-sorber is recovered in the downer-regenerator. The loss in the thermodynamic availability of the system is only 1.5 kJ/gmol CO2 versus the minimum energy of separation of 7.3 kJ/gmol CO2.