https://doi.org/10.3390/en14164822
“The influence of different decarbonation temperatures on the sorbent CO2 uptake capacity has been tested too (Figure 3). The carbonation is performed in the gas flow containing 15 vol.% CO2 at 630 °C (Table 1). The rise in the decarbonation temperature induces a larger drop in CO2 uptake capacity after the 1st decarbonation. Moreover, at a higher decarbonation temperature the decrease in the CO2 uptake capacity is more notable with each increasing cycle number. In the 25th cycle, the CO2 uptake capacity value attains 9.2, 7.6 and 4.5 mmol/g at decarbonation temperatures of 742, 900 and 1000 °C, respectively. The initial CO2 uptake capacity of the sorbent is 10.7 mmol/g for the given carbonation parameters. The rise in the decarbonation temperature also results in the sorbent-specific surface area decrease (Table 3). After 25 carbonation–decarbonation cycles, the sorbent-specific surface area decreases by 3.7, 21.2 and 53.5% in relation to the virgin sorbent-specific surface area value of 21.7 m2/g. It indicates that the increase in the decarbonation temperature stimulates the CaO particles’ growth.”
“Figure 3. CO2 uptake capacity evolution of the sorbent over cyclic carbonation–decarbonation at different decarbonation temperatures. The carbonation is performed in the gas flow containing 15 vol.% CO2 at 630 °C. The insert shows the carbonation profiles of the 25th cycle at different decarbonation temperatures.” https://doi.org/10.3390/en14164822
“The decarbonation temperature also affects the carbonation kinetics of the sorbent (insert in Figure 3). It is revealed that the time to attain 90% of the maximum capacity value in the cycle increases with the rise in the decarbonation temperature. The chemical reaction-controlled stage becomes shorter and slower, and the diffusion-controlled stage becomes longer and starts earlier.”