Desulfurization of odorant-containing gases by sorption on Cu/ZnO/Al2O3: Effects of sulfur compounds

The removal of tetrahydrothiophene (THT), dimethylsulfide (DMS), and the ordorant mixture of t-butylmercaptan and tetrahydrothiophene (TBM plus THT) from gas fuel has been investigated by using a coprecipitated Cu/ZnO/Al2O3 sorbent. It was found that the sorption capacities of THT, DMS, and TBM plus THT on Cu/ZnO/Al2O3 increased with the sorption temperature, and the maximum sorption capacities of 0.89 and 0.78 mmol/g at 350 degrees C and 0.50 mmol/g at 250 degrees C were obtained, respectively, and then decreased with a further increase of the temperature. The Cu/ZnO/Al2O3 adsorbent had a high selective sorption capacity for TBM in the mixture of (TBM and THT). The Brunauer-Emmett-Teller surface areas were decreased after saturation with sulfur compounds. The morphology of the sorbent was changed to rod-shaped grains at 300 degrees C because of the formation of sulfides after THT sorption. The desorption peak (m/e = 32) for DMS on the sorbent during TPD was observed in the temperature range of 350-460 degrees C. The TPD peak (m/e = 45) for THT was detected in the temperature range of 470-540 degrees C. This broad TPD peaks may be attributed to the decomposition of copper sulfide clusters formed on Cu/ZnO/Al2O3 after sorption of sulfur compounds.