Influence of SO2 concentration on carbon capture using NaBr-CaO

“Figure 2(a) showed the effect of different SO₂ concentrations on the CO₂ capture capacity of the NaBr modified “CaO, AR” in the calcium looping environment (as shown in Table 1, run 2#–4#). Figure 2(b) showed the cumulative SO₂ adsorption capacity of the CaO-based sorbents under these different reaction modes. It can be seen that with the progress of the calcium looping process, the cyclic CO₂ capture capacity of the CaO-based adsorbent still decreased rapidly; in addition, with the increase of SO₂ concentration in the reaction, the cyclic CO₂ capture capacity of CaO-based adsorbent decreases more rapidly. Exposed to 0.1 %, 0.2 %, and 0.3 % SO₂ atmosphere (run 2#, 3#, and 4#), “CaO, AR” has a similar CO₂ capture capacity (0.52g-CO₂/g-sorbent) in the first carbonation; but after 10 cycles, the CO₂ capture capacity of “CaO, AR” decreased to 0.211 g/g, 0.181 g/g, and 0.131 g/g, respectively. The SO₂ concentration has a strong relationship with the attenuation of their cyclic CO₂ capture capacity. After 10 cycles, the CO₂ capture capacity of the “CaO, AR” under the condition of 0.1 % SO₂ (mode 2#) was 1.6 times higher than that under the condition of 0.3 % SO₂ (mode 4#). At the same time, with the increase of SO₂ concentration, the sulfation conversion of CaO-based sorbent increased gradually. As shown in Figure 2b, after 1 cycle, the cumulative SO₂ absorption of “CaO, AR” under runs 2#, 3#, 4# was 0.008 g/g, 0.03 g/g, and 0.05 g/g; moreover, with the progress of the calcium looping process, the sulfation conversion rate of the sorbent in the atmosphere of higher SO₂ concentration was also higher. Finally, the cumulative SO₂ capture capacity of the “CaO, AR” in these three modes was 0.14 g/g, 0.29 g/g, and 0.32 g/g respectively.”