NaY分子筛的改性及对FCC汽油选择吸附脱硫的研究

利用草酸对NaY分子筛进行脱铝改性制备了NH4Y分子筛，NH4Y分子筛经过焙烧制得HY分子筛，再用实验制得的NH4Y分子筛进行液相离子交换和焙烧制得Ce（Ⅳ）Y分子筛。对分子筛进行静态吸附脱硫对比实验，并利用微库仑综合分析仪对静态和动态处理过的FCC汽油样品进行硫含量测定。结果表明，在静态条件下，Ce（Ⅳ）Y比HY分子筛的吸附脱硫效果略好，二者吸附脱硫率分别为79.0%和77.8% 。在动态条件下，Ce(Ⅳ)Y分子筛能够脱掉HY分子筛较难脱除的二甲基噻吩类硫化物。再生后的成型Ce(Ⅳ)Y分子筛的吸附能力可达到新鲜Ce（Ⅳ）Y分子筛的95.5%。

STUDY ON THE SELECTIVE ADSORPTIVE DESULFURIZATION OF FCC NAPHTHA BY MODIFIED ZEOLITE Y

NaY zeolite was dealuminated by oxalic acid and ion-exchanged with NH_4 Cl to form NH_4 Y.Then HY was obtained by calcining NH_4 Y,and Ce(Ⅳ)Y was prepared by ion-exchanging NH_4 Y with cerium nitrate solution and calcination.Selective adsorptive desulfurization of FCC naphtha over various zeolite Y samples was conducted and the sulfur contents of naphtha samples were analyzed by microcoulometry.Static adsorption results showed that the sulfur removal rates of zeolite Y samples from high to low were in the order of Ce(Ⅳ)Y>HY>NaY;sulfur removal rates of Ce(Ⅳ)Y and HY were 79.0% and 77.8%,respectively.Kinetic adsorption results showed that dimethylthiophene(DMT) type sulfur containing compounds could be removed by Ce(Ⅳ)Y,but could not be removed by HY.The adsorption capacity of the regenerated Ce(Ⅳ)Y zeolite reached 95.5% of the fresh one.