BNP钝镍剂的工业应用及其钝镍机理

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

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 。

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.