Calcium oxide has been proved to be a suitable sorbent for high temperature CO2 capture processes based on the cyclic carbonation-calcination reaction. In this work several synthetic sorbents have been prepared with CaO contents between 40 and 95% wt. on to two different inert supports MgO and Ca12Al14O33. The effect of CaO content and inert nature on materials CO2 carrying capacity and reactivity towards carbonation reaction has been assessed. The materials have been texturally characterised. A complete kinetic study has been performed and the Random Pore Model has been applied to determine the intrinsic rate parameters for the carbonation reaction. Suitable particles for operation in fixed bed reactor have been produced from some selected powdered materials, and a complete particle reaction model that incorporate the intrinsic kinetic data has been developed and validated.