稀土金属氧化物对Y分子筛吸附脱硫性能的影响

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

以Y分子筛为母体,采用浸渍法制备了Y2O3/Y、CeO2/Y和La2O3/Y三种吸附剂。以脱除正辛烷中的苯并噻吩为探针反应,考察了稀土金属氧化物负载量、吸附温度、吸附时间和剂油比对吸附剂脱硫性能的影响。结果表明,稀土金属氧化物最佳负载量为5%(质量分数),所得吸附剂在50℃、1 h、剂油比1∶30条件下,脱硫率均达到60%以上。甲苯的存在明显降低了吸附剂的脱硫性能。稀土金属氧化物在吸附过程中发生流失,在相同的条件下,三种稀土金属氧化物中,Y2O3的流失量最小,而CeO2的流失量最大,CeO2的流失量是Y2O3的10倍。

Y203/Y, CeO2/Y and La203/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 ~C, 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 Y203 was the least, while CeO2 was the largest. The loss amount of CeO2 was 10 times larger than that of Y203.