H2S removal by peroxo heteropoly compound/ionic liquid solution

•Five peroxo heteropoly compounds were dissolved in ionic liquids to remove H2S.•The H2S removal efficiency can maintain nearly 100% at 95 °C for 2 h.•The desulfurization product has been proved to be sulfur.

In this work, five peroxo heteropoly compounds (PHPCs) were synthesized and dissolved in four ionic liquids (ILs) to remove H2S. The Fourier transform infrared (FT-IR) spectrum, Raman spectrum, elemental analysis, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have demonstrated the successful synthesis of PHPC. Besides, the PHPC and IL were characterized by Thermogravimetry analysis (TGA). The desulfurization results showed that cetyltrimethylammonium peroxophosphomolybdate dissolved in 1-N-butyl-3-methylimidazolium bicarbonate has the best H2S removal capacity. Condition optimization experiments showed that a low H2S concentration and high PHPC concentration is in favor of H2S removal. The optimal absorption temperature is 95 °C at which the H2S removal efficiency could maintain nearly 100% for 2 h. The desulfurization product has been proved to be sulfur. The regeneration experiment showed that the desulfurization capacity of absorbent is weakened after regeneration because of the loss of peroxide. These results indicate that PHPC/IL solution has the potential to remove H2S.

Graphical abstractThe cetyltrimethylammonium peroxophosphomolybdate was synthesized and dissolved in ionic liquid, 1-N-butyl-3-methylimidazolium bicarbonate, to remove H2S. The H2S removal efficiency can maintain nearly 100% at 95 °C for 2 h. The desulfurization product is proved to be sulfur.Download high-res image (204KB)Download full-size image