CeY分子筛对HDS汽油的吸附脱硫及表面酸性的影响规律

摘要

CeY zeolites were prepared by liquid phase ion exchange (LPIE)and solid state ion exchange (SSIE).The adsorbents were characterized by means of XRD,N2 physisorption,ICP and the total surface acidity of the adsorbents was monitored by NH3-TPD and in situ FTIR spectroscopy using pyridine as a probe.Properties of selective adsorptive desulfurization of HDS gasolines on the adsorbents have been investigated in this paper by using a fixed-bed adsorber and a GC-SCD technique.The adsorption capacity was found to follow the order of S-CeY>L-CeY>NaY>HY.After LPIE and SSIE, and CeY zeolites had different surface acidity from NaY and HY,which greatly affected the adsorption desulfurization process. Additionally,Brönsted (B)acid sites was thought toresult in catalytic reaction of thiophene.%用固相离子交换和液相离子交换法制备了 CeY分子筛,利用 X射线衍射(XRD)、N2物理吸附脱附、电感耦合等离子原子发射光谱仪(ICP)等方法表征了吸附剂的物理性质,借助 NH3-TPD及吡啶-原位傅里叶变换红外(Py-FTIR)技术考察了吸附剂表面的酸度分布及酸类型。采用固定床动态吸附实验和色谱-硫化学发光检测(GC-SCD)偶联技术系统考查了改性 Y分子筛对加氢脱硫燃料油的吸附脱硫性能。结果表明,4种 Y分子筛对加氢脱硫油脱硫能力大小顺序为 S-CeY>L-CeY>NaY>HY。表面酸性的差异显著地影响分子筛的吸附脱硫性能,两种方法制备的CeY分子筛表面酸性与 NaY原粉差异较大,分子筛表面B酸中心是噻吩发生催化反应的活性中心。