RMS-8流化催化裂化催化剂氧化法脱钒复活研究

Removal and rejuvenation of vanadium in spent fluid catalytic cracking catalysts

以钒含量较高的RMS 8流化催化裂化催化剂为原料 ,考察了氧化法和酸洗法的脱钒效果。结果表明 ,脱钒率不仅与洗涤条件有关 ,而且与氧化焙烧的条件有关。氧化焙烧时间相同时 ,不同洗涤溶液的脱钒效果也不同 ,其中草酸和H2 O2 混合溶液脱钒效果较好 ;脱钒率随洗涤次数的增加而增加 ,氧化焙烧时间和温度对脱钒效果也有显著影响。在其他条件相同的情况下 ,氧化时间越长 ,氧化温度越高 ,脱钒率也越高。从活性恢复的角度看 ,在脱钒率较低时 ,催化剂的活性即可得到大部分恢复。但再进一步提高脱钒率 ,对催化剂活性的恢复影响不大。

The oxidation and acid washing methods were used to investigate the vanadium removal from RMS-8 fluid catalytic cracking (FCC) catalysts. The removal rate of vanadium was related to the oxidation and acid washing steps. The removal effectiveness of vanadium changed with variation of washing solution. The effect of vanadium removal using mixed solution of oxalic acid and H_2O_2 is optimum. When the catalyst was oxidized under the same condition, the removal rate of vanadium rose with the increase of acid washing number and washing time. The removal rate of vanadium also increased with the oxidation temperature and oxidation time under the same acid washing condition. When a small amount of vanadium was removed, the microactivity of the catalyst could be improved markedly. The further removal of vanadium was noneffective to the microactivity improvement.