Calcium sorbents of limestone and CaO derived from calcined limestone were modified by ethanol water solutions with different bulk ethanol concentrations.The carbonation reaction of the sorbents was investigated and was compared with that of hydrated CaO.The microstructure of the sorbents was examined further with SEM and N2 adsorption method

and the potential mechanism for ethanol water solutions to improve the carbonation conversion was revealed.The results showed that the carbonation conversion of CaO modified by ethanol water solution was higher than that of limestone or CaO hydrated by distilled water with an increase in cycle number.The modification by ethanol water solution had no effect on the conversion of limestone.The CO2  sorption capacity of CaO modified by ethanol water solution at a temperature of 650—700℃ was beneficial to carbonation.The higher the ethanol concentration in solution

the higher the carbonation conversion of modified CaO

and the better the anti-sintering performance.The specific surface area and pore volume of CaO modified by ethanol water solution were higher than those of CaO hydrated by distilled water

and were much greater than those of calcined limestone.The distributions of pore volume and pore area of CaO modified by ethanol water solution were superior to those of hydrated CaO and calcined limestone.The pores in CaO were obviously expanded by an ethanol water solution.