FCC过程中镁铝尖晶石对硫化物的吸附作用

通过比较改性镁铝尖晶石与FCC催化剂在不同装填方式时产品汽油中的硫含量,考察改性镁铝尖晶石对不同烃油馏分硫化物的吸附性能。结合物化表征,探讨催化裂化过程中改性镁铝尖晶石对烃油中硫化物的吸附作用。结果表明,镁铝尖晶石经过渡金属改性后,弱酸比例提高,中孔分布集中,可增强尖晶石对硫化物尤其是较大分子硫化物的吸附能力,吸附原料油和裂化产物中的硫化物,将其转化成焦炭或焦炭前驱物沉积于尖晶石表面,是改性尖晶石降低汽油产物硫含量的重要途径之一。镁铝尖晶石中引入适当的过渡金属,可以实现降低催化裂化汽油硫含量的目标。

Performance of Mg-Al spinel for the adsorption of sulfur-containing compounds in FCC process

By comparing the sulfur contents of gasoline treated by modified spinel and FCC catalyst with different loading ways in reactor beds,the behaviors of modified Mg-Al spinel for reducing sulfur contents in gasoline and LCO products of FCC process were investigated by using VGO as the feedstock.The results of activity evaluation combining physico-chemical characterization showed that after Mg-Al spinel was modified by transition metals,the proportion of weak acid on Mg-Al spinel was increased and the distribution of mesopores was concentrated,which enhanced the adsorption ability of the spinel for sulfur compounds,especially for large molecule sulfide.It was one of the important ways to reduce the sulfur contents of gasoline products by adsorbing the sulfides in the raw materials and the cracking products or converting into coke or coke precursor which deposited on the surface of spinel.The introduction of appropriate transitional metals into Mg-Al spinel was proved to effectively improve its sulfur reduction performance.