Effects of rare-earth metal oxides on the desulfurization of Y zeolite

Y₂O₃/Y, CeO₂/Y and La₂O₃/Y samples were prepared by impregnation with Y zeolites as precursor. Removal of benzothiophene from octane was employed as probe reaction. The effects of loading amount of rare-earth metal oxide, adsorption temperature, adsorption time and ratio of adsorbent to oil on desulfurization have been investigated. The results showed that the optimum loading amount of the rare-earth metal oxide was 5%. More than 60% of benzothiophene was removed over the obtained samples at conditions of 50 ℃, 1 h and 1∶30 of adsorbent to oil ratio. Addition of toluene to the mixture of octane and benzothiophene depressed obviously the desulfurization capability of the samples. The rare-earth metal oxides were washed away during the desulfurization process. The loss amount of Y₂O₃ was the least, while CeO₂ was the largest. The loss amount of CeO₂ was 10 times larger than that of Y₂O₃.