超声法制备Ce^4＋/13X分子筛的吸附脱硫性能

采用在离子交换过程中引入超声的方法制备了Ce4 /13X分子筛,考察了超声法对分子筛的制备及脱硫性能的影响,并考察了静态吸附条件对Ce4 /13X在低硫模型汽油(硫含量为23 mg/kg)中的脱硫性能影响。结果表明,超声法可显著缩短分子筛离子交换平衡的时间,提高离子交换度,且能有效地提高活性组分Ce在分子筛表面的含量,脱硫实验结果也显示吸附容量有明显的提高。常温常压,吸附时间为2.5 h,剂油质量比为0.0072的条件下,Ce4 /13X对噻吩的脱硫效果最好,吸附量为0.07653mmol/g,脱硫率可达到76.5%。Freundlich等温式能很好地关联噻吩在Ce4 /13X上的吸附平衡数据。450℃空气气氛中焙烧4 h的方法,可较好地再生Ce4 /13X。

Adsorption of sulfur-containing compounds on Ce4+/13X zeolite prepared by ulrasound-assisted ion exchange

Ce4 /13X zeolite was prepared by the ultrasound-assisted ion exchange method,and its desulfurization performance for sulfur compounds from model gasoline(sulfur content 23 mg/kg) was evaluated by using static adsorption experiments.The effect of adsorption conditions on the desulfurization performance of the adsorbent was also studied.The results showed that the loading capacity and rate of the Ce4 /13X were significantly improved as compared with the conventional ion-exchange method.XPS analysis indicated that the use of ultrasound promoted the distribution of Ce ions on the surface of the adsorbent.And the adsorption capability of thiophene on Ce4 /13X was also superior to that prepared by the conventional method.Under the conditions of adsorption:desulfurization time 2.5 h,mass ratio of adsorbent to fuel 0.0072,the adsorption capacity of thiophene was 0.07653 mmol/g,and the best desulfurization rate could reach 76.5 %.The adsorption equilibrium data for thiophene on Ce4 /13X were tested and fitted with the Freundlich model.The saturated adsorbent can be regenerated with calcination at 450 oC for 2 h in air,and about 95 % of the desulfurization capacity was recovered.