BNP钝镍剂的工业应用及其钝镍机理

工业试验表明 :在 FCC催化剂的镍污染量高达 1 %时 ,BNP低毒钝镍剂仍能有效提高汽油收率 1 % ,使氢气和焦炭产率分别降低 35 %和 1 0 %以上 ,显示出良好的钝镍效果。结合 MAT,TPR,XRD等实验方法和量子化学计算理论研究阐明了该钝镍剂的钝镍机理 :在 FCC再生条件 (约 70 0℃ ,氧化性气氛 )下 ,BNP热分解生成 B2 O3 并与 Ni O反应生成 Ni2 B2 O5,有效地抑制了催化剂上低价镍的脱氢活性 ,从而达到钝镍的目的

INDUSTRIAL APPLICATION OF NICKEL PASSIVATOR(BNP) IN FCC AND ITS RELATIVE MECHANISM

The industrial application in FCC showed that even if the catalyst was contaminated by Ni up to 1%, the low toxic nickel passivator(named BNP) consisting of boron could decrease the yields of hydrogen and coke by 35% and 10% respectively, mean while increasing the yield of gasoline by 1%. The mechanism of nickel passivation by BNP was also investigated, in which the methods of MAT, TPR and XRD were used, combined with quantum chemistry calculation. The results showed that B 2O 3 is formed and react with NiO to form Ni 2B 2O 5 forms after the addition of BNP to Ni deposited zeolite under the condition of FCC regeneration. Because the energy of LUMO of Ni 2B 2O 5 is much higher than that of NiO, Ni 2B 2O 5 is more difficult to be reduced than NiO under the conditions of FCC reaction. Therefore, the dehydrogenation activity of Ni 0 is inhibited. This is the nickel passivation mechanism of BNP.