Enhancement effect of nanofluids on the desulfurization and regeneration performance of ionic liquid-based system

The desulfurization and regeneration performance of nanofluids composed of oxidizing ionic liquids and four inert nanoparticles are investigated. The addition of different nanoparticles has been proved to have enhancement effect on the H₂S removal performance of oxidizing ionic liquids. The nanofluids with SiO₂ nanoparticles showed the most significant strengthening desulfurization performance as well as regeneration performance. The optimal weight ratio of SiO₂ nanoparticles in nanofluids was confirmed as 0.5%. The regeneration efficiency of the optimal nanofluid system can exceed 88%, which is far higher than that before the addition of SiO₂ nanoparticles. The mass transfer coefficient increased significantly after the addition of nanoparticles. The nanoparticles and nanofluids before and after absorption were characterized by Fourier transform infrared spectra, nuclear magnetic resonance, scanning electron microscope, transmission electron microscope, energy dispersive spectrum and X-ray photoelectron spectroscopy. It was found that the structure and morphology of SiO₂ nanoparticles remained basically unchanged in the absorption-regeneration process. The main final desulfurization product was identified as sulfate.