抄録
Selective oxidation of hydrogen sulfide was studied on zeolite-NaX and zeolite-KX. Elemental sulfur yield on zeolite-NaX was achieved about 90% at 225°C for the first 4 hours, but it was gradually decreased to 55% at 40 hours after the reaction started. However, the yield on zeolite-KX was obtained in the range of 87∼85% at the same reaction condition after 40 hours. The deactivation of the zeolite-NaX catalyst was caused by the coverage of the certain sulfureous species. The coverage of the sulfureous species on the zeolite-NaX was confirmed by the temperature-programmed oxidation experiments utilizing thermogravimetric analyses. Even though the higher temperature conditions for the selective oxidation were required for preventing the deactivation, it can not be raised into 250°C or above due to the SO2 production. The SO2 production was observed in the selective oxidation on zeolite-NaX rather than on zeolite-KX and was affected on the decrease of selectivity to the elemental sulfur. Result in this study showed that the zeolite-KX is superior to the zeolite-NaX for the selective oxidation of hydrogen sulfide to the elemental sulfur.
