Regeneration of sintered limestone sorbents for the sequestration of CO2 from combustion and other systems

The capacity of particles of CaO, produced by calcining limestone, to reactively absorb CO2, degrades with the number of cycles of carbonation and calcination. A novel method of reactivating the stone in humid, ambient air is described. Typically, a calcined limestone has a carrying capacity for CO2 which falls fromy similar to 79% (on the basis of moles of CO2 permole of CaO) to only about 20-30% after 30 cycles of regeneration and reuse. This new technique enables the carrying capacity to be restored to similar to 55%, thereby improving the economics of sequestrating CO2 using a calcium-based sorbent.