This study focuses on developing a CO2 sorbent with high sorption capacity and long life by a coprecipitation method. The synthesis conditions were optimized. The sorbent synthesized under the optimal synthesis conditions presented a high carbonation rate and high CO2 uptake with greatly improved resistant against sintering behavior. The decay in carbonation conversion depended on the reaction conditions and the number of cycles during multiple carbonation/calcination cycles. A combination of 700 degrees C and 0.5 MPa was considered as an optimal condition for the best sorbent to achieve high cyclic CO2 capture capacity, i.e. increased by 35% for 10 cycles and by 79% for 50 cycles compared with limestone in the atmosphere of 15% CO2 and 35% N-2. Little effect was found on CO2 uptake with different particle size distribution. An average conversion of 0.86 after 50 cycles was achieved. Characterization results failed to show any significant difference in morphological or structural properties of the sorbent before and after multiple cycles at 700 degrees C and 0.5 MPa which explained the superior performance of the sorbent. The active component of the sorbent was CaO, while the Ca9Al6O18 and MgO provided a stable framework inhibiting deactivation of CaO. (C) 2011 Elsevier B.V. All rights reserved.