Effect of steam addition during carbonation, calcination or hydration on re-activation of CaO sorbent for CO2 capture

•The effect of steam to re-activate the spent sorbent for CO2 capture was studied.•Steam addition during carbonation improved sorbent structure and its reactivity.•The effect of steam during calcination was influenced by the concentrations.•Steam hydration enhanced the formation of cracks for increased particle surfaces.•Injecting steam during carbonation was a more favourable option to be recommended.