AgY和AgMgY吸附剂吸附脱硫性能的考察

Investigation of adsorption desulfurization of gasoline by AgY and AgMgY adsorbents

采用液相离子交换法制备一系列AgY和AgMgY吸附剂。以噻吩的正辛烷溶液为模型化合物,在小型固定床上考察不同浓度硝酸银和硝酸镁制备的AgY单金属吸附剂和AgMgY双金属吸附剂的吸附脱硫性能。结果表明:当Ag+为0.30 mol/L、Mg2+为0.15 mol/L时,吸附剂的脱硫能力最佳。从穿透曲线可看出:每克AgY、AgMgY吸附剂的最大处理量分别为72、120mL汽油,AgMgY双金属吸附剂的脱硫性能明显好于AgY单金属吸附剂。通过X射线衍射仪(XRD)、X射线荧光光谱仪(XRF)、程序升温还原(TPR)和傅里叶变换红外光谱仪(FT-IR)等对吸附剂进行表征,发现Mg2+的存在(作为一种助剂)提高了吸附剂的L酸含量并使其还原性增强,更有利于吸附。经过再生后的吸附剂,其脱硫能力较新鲜吸附剂相比没有明显的下降。

AgY and AgMgY adsorbents are prepared by liquid ion-exchange method. The effect of concentration of AgNO3 and Mg（ NOz ）2 on the adsorption desulfurization of AgY and AgMgY is investigated by small fixed bed using thiophene in the n-hexane as model gasoline. The results show that, the best adsorption desulfurization can be obtaind with 0. 3 mol/L of the concentration of Ag ＋ solution and 0. 15 mol/L of the concentration of Mg^2 ＋ solution. It also can be seen from the breakthrough curve that the maximum treatment capacity of AgY and AgMgY is 72 mL/g and 120 mL/g. The adsorption desulfurization property of AgMgY is much better than that of AgY. The adsorbents are characterized by XRD,XRF,TPR, FI-IR,and so on. The presence of Mg^2＋ as a co-catalyst helps to increase the content of Lewis acidity and enhance its reduction ability which is beneficial to improve the adsorption desulfurization. Adsorption capacity of the used adsorbents is not descended comparing with new adsorbents.