Intensification of CO absorption and desorption by metal/non-metal oxide nanoparticles in bubble columns.

In this study, four different metal/non-metal oxide nanoparticles including CuO, FeO, ZnO, and SiO were employed to improve CO absorption and desorption in methyl diethanolamine (MDEA)-based nanofluid. CO absorption experiment with various nanofluids was done in a bubble column reactor at ambient temperature. Also, CO stripping experiments for all nanofluids were done at 60 and 70 °C. The influence of nanoparticles type, nanoparticle concentration, and the stability of nanoparticles were studied on both CO absorption and stripping. The obtained results revealed that FeO nanoparticles at 0.01 wt.% concentration had the best influence on CO absorption and it improved the CO loading up to 36%. Also, CO stripping experiments for all nanofluids were done at 60 and 70 °C. The desorption experiments illustrated that metal oxide nanoparticles can be more efficient in improving CO desorption. In CO desorption, the CuO nanoparticles at 0.05 wt.% had higher efficiency, and enhanced CO concentration at outlet gas phase up to 44.2 vol.% at 70 °C. Finally, as an indication, the chemical stability of FeO NPs under optimum operational conditions was studied using XRD analysis and the result showed that the proposed operational condition did not have any negative effect on the chemical nature of FeO NPs.