LAUSR

Abstract The conventional impregnation was improved by acid modification as surface treatment to obtain the higher performance of solid sorbent, potassium carbonate supported on gamma alumina, for carbon dioxide (CO2) sorption. Acid modification affected on the shape of the sorbents. Weak acids, phenol and acetic, provided round shape with uniform size distribution. In contrast, strong acids, hydrochloric and sulfuric, obtained sharp edges irregular shape sorbent with broad size distribution. The CO2 capture capacity was improved by weak acid modification. All modifications could increase surface area of sorbent except for phenol modification. The highest CO2 sorption capacity was obtained from acetic acid modification due to the better crystallinity condition of the modified sorbent. Direct acetic acid modification with impregnation time of 24 h was suggested to be the suitable modification method. The modified sorbent showed a good regeneration property. The modified sorbent was compatible with the continuous mode of CO2 capture unit using circulating fluidized bed reactor, which consumed less energy than commercialized liquid amine absorber-stripper unit.