Experimental study on carbon capture characteristics of marine engine exhaust gas by activated potassium carbonate absorbent.

Post-combustion carbon capture is a direct and effective way for onboard carbon capture. Therefore, it is important to develop onboard carbon capture absorbent that can both ensure a high absorption rate and reduce the energy consumption of the desorption process. In this paper, a KCO solution was first established using Aspen Plus to simulate CO capture from the exhaust gases of a marine dual-fuel engine in diesel mode. The lean and rich CO loading results from the simulation were used to guide the selection and optimization of the activators used in the experiment. During the experiment, five amino acid salt activators including SarK, GlyK, ProK, LysK, and AlaK and four organic amine activators including MEA, PZ, AEEA, and TEPA were used. Experiments only considered the activation effect of CO loading between lean and rich conditions. The results showed that after adding a small amount of activator, the absorption rate of CO by the absorbent was greatly improved, and the activation effect of organic amine activators was stronger than that of amino acid salts. Among the amino acid salts, the SarK-KCO composite solution showed the best performance in both absorption and desorption. Among the amino acid salts and the organic amino activators, SarK-KCO showed the best performance in strengthening the CO desorption while PZ-KCO enhanced the CO absorption process the most. In the study of the concentration ratio, it was found that when the mass concentration ratio was 1:1 for SarK:KCO and PZ:KCO, the CO absorption and desorption processes improved well.