A novel synthetic sorbent.was fabricated from CaO and sepiolite by the hydration and its CO2 capture performance was investigated during the calcium looping cycles. The effects of the sorbent preparation conditions including preparation method, hydration temperature, hydration duration and sepiolite content on CO2 capture by synthetic CaO/sepiolite sorbent were examined in a dual fixed-bed reactor. The results showed that CaO/sepiolite possesses higher CO2 capture capacity than original CaO. CO2 capture capacity of CaO/sepiolite after 10 cycles is 39% and 56% higher than those of hydrated CaO and original CaO, respectively. The hydration temperature has an important effect on CO2 capture by CaO/sepiolite during the preparation. When the hydration temperature is 95 degrees C, the obtained CaO/sepiolite exhibits the highest cyclic CO2 capture capacity, because the good supports such as MgO and Ca2SiO4 are formed in the calcined CaO/sepiolite at 95 degrees C, which can improve the sintering resistance of CaO during the cycles. However, these supports are not found in the calcined CaO/sepiolite at the other hydration temperatures. In addition, CaO/sepiolite possesses more porous structure, larger surface area and pore volume, compared to hydrated CaO and original CaO. After the 1st calcination, the volume of pores in 10-100 nm in diameter of CaO/sepiolite is much higher than those of hydrated CaO and original CaO, respectively, which facilitates CO2 capture of the sorbent. CaO/sepiolite appears promising as an effective and lowcost CO2 sorbent at calcium looping conditions. (C) 2017 Elsevier Ltd. All rights reserved.