Several concepts to capture CO2 are under developing using CaO as regenerable sorbent. The drastic decay in sorbent capture capacity of CaO obtained from natural sources of CaCO3 is leading to an increasing number of authors proposing synthetic sorbents to overcome this decay. Some recent developments have been reviewed and tested under comparable conditions. Results confirm the good performance of some of these synthetic sorbents under mild conditions. However, they deactivate also very quickly when realistic regeneration conditions (high calcination temperatures and high concentration of CO2) are used in the laboratory test. It is concluded than none of the reviewed synthetic sorbents have a chance to compete with the "modest" performance of natural limestones that show two competitive advantages: The maintenance of a suitable CO2 capture capacity under demanding process conditions; and their intrinsic low cost.

European Commission (Comisión Europea), C3-Capture and the Spanish Ministry of Education (Ministerio de Educación) "Juan de la Cierva" Program

Peer reviewed