Novel regenerable potassium-based dry sorbents for CO2 capture at low temperatures

A novel potassium-based dry sorbent (KZrI) was developed for CO2 capture at a low temperature range between 50 °C and 200 °C. The CO2 absorption and regeneration properties of this novel regenerable potassium-based dry sorbent were measured in a fixed-bed reactor during multiple absorption/regeneration cycles at low temperature conditions (CO2 absorption at 50–100 °C and regeneration at 130–200 °C). The total CO2 capture capacity of the KZrI sorbent was maintained during the multiple CO2 absorption/regeneration cycles. The XRD patterns and FTIR analyses of the sorbents after CO2 absorption showed the KHCO3 phase only except for the ZrO2 phase used as support. Even after 10 cycles, any other new structures resulting from the by-product during CO2 absorption were not observed. This phase could be easily converted into the original phase during regeneration, even at a low temperature (130 °C). The KZrI sorbent developed in this study showed excellent characteristics in CO2 absorption and regeneration in that it satisfies the requirements of a large amount of CO2 absorption (91.6 mg CO2/g sorbent) and the complete regeneration at a low temperature condition (1 atm, 150 °C) without deactivation.