Simultaneous absorption of carbon dioxide (CO2) and hydrogen sulfide (H2S) from CO2-H2S-CH4 gas mixture using amine-based nanofluids in a wetted wall column

In this study, to remove CO2 and H2S from a natural gas stream through some absorption experiments, a nanofluid containing SiO2 and Al2O3 nanoparticles in Diethanolamine was used. We employed a wetted wall column system in a laboratory scale. Some quantities including the nanoparticle dosage, the liquid, and gas flow rates were adjusted to the best removal percent. The range of nanoparticle concentration varied from 0.005 to 0.5 wt. % in our experiments. The nanofluids were prepared by ultrasonic treatment and showed acceptable stability. In addition, a parametric analysis was performed to explore the effects of particle types, as well as concentrations on absorption of H2S and CO2. The results showed up to 33% improvement of CO2 absorption at 0.05 wt. % of Al2O3/DEA nanofluids, and also 40% at 0.05 wt.% of SiO2/DEA nanofluids for sample no.1 (feed gas mixture composition: 50 ppm H2S and 3% CO2 in balance of CH4). Moreover, adding silica nanoparticles to DEA deteriorated the absorption of H2S; whereas using Al2O3/DEA nanofluid with 0.1wt.% Al2O3 enhanced the absorption by 14%.