改性Y型分子筛对硫醇硫醚的吸附脱除研究

通过液相离子交换法制备了Cu(I)Y、Ni Y、Ce Y分子筛,以XRD、低温N2吸附-脱附、NH3-TPD、吡啶红外Py-FTIR等方法对其进行物性表征。利用固定床技术、WK-2D微库伦仪及硫化学发光检测GC-SCD色谱评价了改性分子筛对于硫含量300μg/g模拟油(含硫化合物二丙硫醚、环己硫醇和1-庚硫醇与壬烷配制)及HDS汽油的吸附脱硫性能。结果表明,吸附剂对模拟油和HDS燃料油品中硫醇硫醚具有吸附效果,且改性后的分子筛在吸附脱硫过程中,强的B酸对于吸附脱硫有负作用,会使油品中硫醇硫醚发生催化反应,聚合的大分子硫化物遮盖及阻塞吸附活性位点,从而使吸附剂不能够完全地吸附硫化物,造成吸附硫容较小,而弱L酸无催化活性对吸附脱硫有正面影响。

Study on thiol and thioether removal with modified Y zeolite

Samples of Cu (I) Y, NiY and CeY were prepared by modifying a NaY type zeolite with a liquid ion-exchange method and characterized by means of XRD, ICP-MS, pyridine Py-FTIR, NH₃-TPD and low temperature N₂ adsorption-desorption.Use of micro coulombmeter WK-2D, sulfide luminescence detecting chromatography GC-SCD and fixed bed technology to evaluate the desulfurization performance of the samples for a 300 μg/g sulfur content model oil (dipropyl sulfide, cyclohexanol mercaptan and 1-heptyl mercaptan are prepared with nonane, etc.) and a hydrodesulfurization (HDS) gasoline. Results show that Cu (I) Y has good adsorption desulfurization performance on those different oils. In the liquid ion-exchange process, the modified Y zeolite's surface acidity has greatly changed. The strong surface Bronsted (B) acidity of modified Y zeolite has negative effects on adsorption desulfurization through catalyzing mercaptan and thioether to form bigger molecules, which cover the surface of Y zeolite and block the adsorption activity sites, resulting in lower sulfur adsorption capacity of the catalyst. The weak surface Lewis (L) acidity has positive effects on adsorption desulfurization.