Experimental studies of modified limestone for CO2 capture in multiple carbonation/calcination cycles

• Domestic limestone from eastern Taiwan was carried out to investigate the absorption performance of CO2.
• The modified CaO sorbents were operated to enhance the CO2 capture.
• The liquid-phase hydration treatment on the CaO sorbent improves the capture capability of CO2.
• Conversions for the repetitive carbonation/calcination reaction were evaluated under different operating conditions.
• The empirical models for the repetitive carbonation/calcination were compared with the experimental results.

Experimental investigations have been carried out on the calcium oxide obtained by the calcination of domestic limestone from eastern Taiwan to determine the absorption performance of CO2. Repetitive carbonation/calcination reaction with modified sorbents, i.e., the synthetic sol–gel sorbent (sol–gel), limestone modified with pyroligneous acid (PA), and cesium-doped CaO sorbents (doped Cs) in a fixed bed was operated to enhance the reactivity and durability of the sorbents for CO2 capture. The liquid-phase hydration treatment on the modified sorbent was also employed to improve the capture capability of CO2. Conversions for the repetitive carbonation/calcination reaction of modified sorbents were evaluated under different operating conditions. The empirical models for the decay of the CO2 capture by the previous investigation were presented in comparison with the experimental results.