常温常压下β沸石改性吸附剂脱除噻吩类硫的研究

常温常压下β沸石改性吸附剂脱除噻吩类硫的研究

  • 摘要: 在合成不同硅铝比Naβ沸石的基础上,采用固相离子交换方法制备了Cu(I)、Ag(I)离子改性的β沸石系列吸附剂。样品的结晶度和BET比表面积有所降低,XRD表征结果表明,所制备的样品保持了结构的完整性,随着硅铝比的增加,Naβ样品的BET比表面积增加。Cu(I)、Ag(I)离子的引入使样品的红外骨架振动峰向低波数移动,与相同硅铝比的Naβ沸石相比,吸附剂的BET比表面积有所降低。对模型油的静态吸附结果表明,硅铝摩尔比为25时Cu(I)β吸附性能最好,模型油中硫的质量分数降到10×10-6以下,脱除率达到95%,Ag(I)β次之,脱除率达到87%。常温常压下固定床动态吸附穿透实验得到Cu(I)β、Ag(I)β的穿透硫容分别为0.144mmol/g和0.132mmol/g。

     

    Abstract: Through solidstate ionic exchange technique, a series of Cu(I), Ag(I) cation modified zeolite β sorbents were prepared on the base of preparation of Na β zeolite with different Si/Al ratio. The samples were characterized by XRD, FTIR and N2 adsorptiondesorption technique. Although the crystallicity and BET surface area of the sorbents are affected by exchanged metal cation in the framework, the XRD results show that asmade samples were kept framework structure integrity. The BET surface areas of asmade Na β samples decrease as the Si/Al ratio increase, and BET surface areas of Cu(I β , Ag(I)β sorbents decrease comparing with the same Si/Al ratio Na βzeolite. FTIR spectra of the samples show that the peak of framework vibration moves to low wave number as Cu(I), Ag(I) were inserted. Then the thiophene adsorption properties of Cu(I) β , Ag(I) β , Na β were evaluated at ambient conditions. Static state experimental results show that Cu(I)β exhibits stronger adsorption for thiophene. As the Si/Al mol ratio of zeolite β is 25 about 95% thiophene was adsorbed by Cu(I) β and 87% by Ag(I) β . Through dynamic adsorption experiments, the breakthrough capacities of the Cu(I)β and Ag(I) β sorbents are 0.144mmol/g and 0.132mmol/g, respectively.

     

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