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.