A new regenerable alumina-modified sorbent was developed for CO2 capture at temperatures below 200 degrees C. The CO2 capture capacity of a potassium-based sorbent containing Al2O3 (KAlI) decreased during multiple CO2 sorption (60 degrees C) and regeneration (200 degrees C) tests due to the formation of the KAl(CO3)(OH)(2) phase, which could be converted into the original K2CO3 phase above 300 degrees C. However, the new regenerable potassium-based sorbent (Re-KAl(I)) maintained its CO2 capture capacity during multiple tests even at a regeneration temperature of 130 degrees C. In particular, the CO2 capture capacity of the Re-KAl(I) 60 sorbent which was prepared by the impregnation of Al2O3 with 60 wt.% K2CO3 was about 128 mg CO2/g sorbent. This excellent CO2 capture capacity and regeneration property were due to the characteristics of the Re-KAl(I) sorbent producing only a KHCO3 phase during CO2 sorption, unlike the KAlI30 sorbent which formed the KHCO3 and KAl(CO3)(OH)(2) phases even at 60 degrees C. This result was explained through the structural effect of the support containing the KAl(CO3)(OH)(2) phase which was prepared by impregnation of Al2O3 with K2CO3 in the presence of CO2. (C) 2010 Elsevier Ltd. All rights reserved.