초록 |
In purification of natural gas and crude oil plants and the steel smelting process lead to huge amounts of highly poisonous hydrogen sulfide (H2S). For few decades, most of H2S in oil refineries and smelt plants has been removed by converting it into elemental sulfur using the Claus process. However, the separation of H2S from the solution is not perfect, hence the 3-5 % H2S remained which causes SOX emission problem during the incineration. One attractive solution is the selective catalytic oxidation of H2S to ammonium thiosulfate (ATS) and elemental sulfur. In this study, we examined performance of the niobium oxide supported on iron-pillared Montmorillonite clay (Nb/Fe-PILC) catalysts for the selective oxidation of H2S. The synthesized catalysts were analyzed by XRD, BET, ICP, NH3-TPD, H2-TPR and XPS. 3wt. % Nb2O5/Fe-PILC showed the highest H2S conversion among all the catalysts tested. It exhibited over 95% H2S conversion without any significant emission of sulfur dioxide at 220 - 300℃. For the better effective understanding of reaction mechanism, the distribution of production of products (S and ATS) was also discussed. |