Influence of SO2 concentration on carbon capture using NaBr-dolomite adsorbent

https://doi.org/10.1016/j.ccst.2021.100015

“Figure 3 showed the effects of SO₂ concentrations (as shown in Table 2, run 2#–4#) on the CO₂ capture capacity and cumulative SO₂ adsorption capacity of NaBr modified “Dolomite” in the calcium looping process. It can be seen that with the increase of SO₂ concentration in the reaction, the cyclic CO₂ capture capacity of the CaO-based sorbent decreased more rapidly. When exposed to 0.1 %, 0.2 %, and 0.3 % SO₂, the cyclic CO₂ capture capacity of dolomite decreased rapidly from 0.31 g/g, 0.27 g/g, and 0.26 g/g during the 1^st reaction to 0.14 g/g, 0.08 g/g and 0.06 g/g during the 10^th reaction; at the same time, after 10 reactions in these atmospheres, the cumulative SO₂ capture capacity of dolomite was 0.162 g/g, 0.225 g/g and 0.280 g/g respectively.”

“Exposed in the atmosphere of 0.1%, 0.2%, and 0.3% SO₂, the “NaBr/Dolomite” showed a slightly weaker CO₂ capture capacity in the first cycle than the “Dolomite”; however, “NaBr/dolomite” showed significantly better cyclic stability over the cycles, i.e., after 10 cycles, the modified adsorbent showed an increase of 1.63 times, 2.81 times and 3.32 times on CO₂ capture capacity than that of “Dolomite”. In addition, the cumulative SO₂ capture capacity of “NaBr/Dolomite” over the 10 cyclic reactions is 0.176 g/g, 0.27 g/g, and 0.335 g/g respectively. With the increase of SO₂ concentration, its cumulative SO₂ capture capacity has been significantly improved. Hence, NaBr modification improved the SO₂ capture capacity of dolomite, but the sulfation of the absorbent did not reduce its cyclic CO₂ capture capacity.”

“Figure 3. (a). Effect of SO₂ concentration on CO₂ capture characteristics in the “NaBr/Dolomite” over the calcium looping process; (b). Effect of NaBr modification on the cumulative SO₂ capture capacity of “Dolomite”.”