FCC汽油降烯烃助剂的研究

中国车用汽油的突出问题之一是烯烃过高，汽油中烯烃过高将在发动机中产生沉积物，增加发动机有害物排放。催化裂化汽油的烯烃体积分数高以及催化裂化汽油在汽油调和组分中占有过高的比例，是中国目前成品汽油中烯烃体积分数过高的主要原因。国内汽油总量中FCC汽油占80％以上，而FCC汽油的烯烃体积分数为40％～55％。因此降低FCC汽油烯烃体积分数具有重要意义。

Study on additives for reducing olefins in the FCC gasoline

The additives for reducing the olefins in the fluid catalytic cracking (FCC) gasoline were prepared by peptization. The effect of additives for reducing the olefins in the gasoline was evaluated in the micro reactor. The additive with the molar ratio of Mg and Al (n/n), 1∶1, had the best olefins reducing reaction activity. XRD result showed that MgAl2O4·MgO spinel was formed in the additive. Studied by Infrared Ray, it was found that the amount of total L acid decreased by adding the content of rare earth. Meanwhile the amounts of weak L acid and the total weak acid increased. Thereby，the hydrogen migration activity of FCC catalyst increased. When the content of the rare earth was 20%, the olefins reducing activity was 45.45%. Studied by XRD, it was thought that the effect of reducing the olefins of the FCC gasoline was the result of the cooperative efforts of MgAl2O4 and ReO2.