A novel sorbent consisting of NaOH/CaO was developed for CO2 capture at 315 degrees C suitable for high-temperature CO2-capture applications, such as coal gasification systems. The sorbent is regenerable at 700 degrees C, and steam does not affect the sorbent performance. A multicycle test conducted in the atmospheric reactor at 315 degrees C indicated that the sorbent improved the performance with an increased number of cycles. The sorbent can also capture CO2 at a wide range of temperatures from ambient to 500 degrees C. However, the mechanism of CO2 capture is different at ambient temperature. The sorbent is unique because it has a high CO2-capture capacity of more than 3 mol/kg at 315 degrees C and is regenerable at 700 degrees C.