Integrated carbon capture and utilization via plasma-assisted KHCO3 decomposition

Abstract The carbonation of K 2 CO 3 to KHCO 3 is an interesting CO 2 capture process due to its low material cost, high selectivity, and substantial CO 2 capacity. Traditionally, KHCO 3 is regenerated into K 2 CO 3 through thermal decomposition. However, plasma-assisted decomposition presents a promising alternative, enabling not only CO 2 desorption but also the concurrent production of valuable products such as H 2 and CO. In this study, KHCO 3 particles in a size range of 250–355 µm were packed in a dielectric barrier discharge reactor and exposed to plasma. It was found that the decomposition of KHCO 3 in the plasma reactor is mainly driven by a thermal mechanism, and the decomposition rate was controlled by temperature increase via plasma heating. The energy consumption for decomposition is more than one order of magnitude higher compared to the thermal approach reported in the literature. However, production of CO and H 2 was achieved during plasma treatment, highlighting the potential advantage of an integrated CO 2 capture and utilization process, and the best CO 2 conversion and energy efficiency achieved were 9.0% ± 0.2% at 3.0% ± 0.1% with a syngas ratio of 0.35 ± 0.01.