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采用液相离子交换(LPIE)法制备了CeY分子筛,并研究烯烃和芳烃对其吸附脱硫性能的影响.利用固定床穿透曲线技术研究吸附剂的脱硫性能,结果表明:烯烃和芳烃的存在均导致吸附剂吸附硫容量减少,然而,烯烃的影响明显强于芳烃.采用原位傅里叶变换红外(FTIR)光谱技术研究噻吩、环己烯和苯的吸附行为,结果发现:烯烃和芳烃降低吸附剂脱硫性能的实质分别为吸附剂表面酸性导致的酸催化反应和π-络合吸附的芳烃分子与硫化物分子的竞争吸附.另外,烯烃的影响取决于吸附剂的表面酸性,尤其是强B酸(Br?nsted酸)中心.这是由于B酸中心会导致烯烃和噻吩发生质子化反应,且质子化物种易于进一步发生低聚反应.生成的低聚物覆盖吸附活性中心导致吸附剂对其它噻吩分子的吸附能力降低.
CeY zeolites were prepared by liquid-phase ion exchange (LPIE) method and the effects of olefins and aromatics on their adsorption desulfurization performance were studied. The desulfurization performance of adsorbents was studied by fixed bed breakthrough curve. The results showed that the presence of both olefins and aromatics However, the influence of alkene was stronger than that of aromatics. The adsorption behavior of thiophene, cyclohexene and benzene were studied by in situ Fourier transform infrared (FTIR) spectroscopy. The results showed that the content of olefins and aromatics decreased The essence of adsorbent desulfurization performance is the acid-catalyzed reaction caused by the acidity of adsorbent surface and the competitive adsorption of aromatic molecules and sulfide molecules adsorbed by π-complexation. In addition, the influence of olefin depends on the surface acidity of the adsorbent, especially the strong Br Br ’acid because of the B acid center will lead to olefin and thiophene protonated reaction, and protonated species prone to further oligomerization reaction of the resulting oligomer covering the active site of adsorption led to adsorbent pairs The adsorption capacity of other thiophene molecules is reduced.