The greenhouse gas making the largest contribution from human activities is carbon dioxide (CO2) that is released into the atmosphere due to the use of fossil fuels (oil,natural gas,and coal).At present,the global concentration of CO2 in the atmosphere is increasing.If recent trends in global CO2 emissions continue,the world will not be on a path towards stabilization of greenhouse gas concentrations [1].One of the more efficient techniques for removal of CO2 is the chemical sorption of CO2 with regenerable solid sorbents.In particular,alkali metal-based sorbents could be utilized in CO2 capture at low temperatures (50-70°C).Thermal regeneration easily occurred at low temperatures of <150°C [2-4].Potassium-based sorbents using alumina as a support were prepared by the impregnation of various aluminas with 30 wt% K2CO3 as previously reported [5,6].Their CO2 sorption and regeneration properties were investigated in a fixed bed reactor during multiple CO2 sorption and regeneration tests at a low temperature range between 60 °C and 200 °C.The potassium-based sorbent using gamma-alumina (γ-Al2O3) as a support was deactivated by the by-product such as a KAl(CO3)(OH)2 during multiple tests.To overcome this problem,a new potassium-based sorbent using alpha-alumina (α- Al2O3) as a support was developed in this study.This sorbent showed excellent regeneration properties,as well as high CO2 capture capacity during multiple CO2 sorption and regeneration tests at 60°C and 200°C,respectively.This result was due to the formation of KHCO3,which could be easily regenerated even at 130°C,during CO2 sorption without by-products like the KAl(CO3)(OH)2 phase,resulting from the structure effect of alumina.In addition,structure effects of alumina used as a support will be discussed with the aid of Power X-ray diffraction,TGA/DTA,and temperature programmed desorption (TPD).