Influence of regeneration temperature of BeO-doped CaO for CO2 capture

https://doi.org/10.1039/D1RA09250B

“It was needed to be explored whether heat transfer enhancement of the adsorbent by BeO dopant could reduce the constant regeneration temperature during CaL process. The test results of regeneration time and decomposition conversion of CaAl adsorbent calcined at 800 °C and 770 °C as well as CaBe2Al adsorbent regenerated at 800 °C, 770 °C, 750 °C and 730 °C are listed in Table 5. The regeneration time referred to the time required for the CaCO₃ decomposition rate decreasing to zero. The results showed that when the regeneration temperature of Ca/Al adsorbent reduced from 800 °C to 770 °C, the regeneration time would be extended from 46 min to 83 min and the decomposition conversion would be reduced from 97.7% to 83.4%. Therefore, in order to ensure the nearly complete decomposition of CaCO₃, the minimum regeneration temperature of Ca/Al adsorbent was 800 °C. In contrast, the CaCO₃ decomposition rate of CaBe2/Al adsorbent could be significantly improved at lower regeneration temperature. At 750 °C, the regeneration time of CaBe2/Al adsorbent was only 48 min, and its decomposition conversion was still as high as 95.1%. However, its regeneration time would greatly increase to 72 min and decomposition conversion would significantly reduce to 85.3% at lower 730 °C. It could be concluded that the minimum regeneration temperature of CaBe2/Al adsorbent was 750 °C, which meant that the heat transfer enhancement of the adsorbent could effectively reduce the regeneration temperature of 50 °C in CaL process.”

Table 5 Regeneration properties of Ca/Al and CaBe2/Al adsorbents