Abstract
The influence of a routine step, washing, following the preparation of calcined rare earth exchanged Y zeolite (REY), on its hydrothermal stability, was studied. The amount and the chemical type of the acidic media used for washing could significantly influence the content of remaining non-framework aluminum (NFA) and consequently further affect the hydrothermal stability of the washed REY products. The content of remaining NFA in REY-A series zeolite played a key role in the hydrothermal stability of the zeolite samples. The crystallinity retention was obviously very closely related to the removal of NFA species. In other words, the less NFA species remained in zeolite samples, the higher crystallinity retention of REY could be achieved. The removal of NFA by different leaching media decreased in the order: REY-B-3 > REY-B-1 > REY-B-4 > REY-B-2. For industrial practice, the leaching medium ammonium sulfate + ammonia water is recommended for the NFA removal.
| Original language | English |
|---|---|
| Pages (from-to) | 47-51 |
| Number of pages | 5 |
| Journal | China Petroleum Processing and Petrochemical Technology |
| Issue number | 2 |
| State | Published - Jun 2005 |
| Externally published | Yes |
Keywords
- Hydrothermal stability
- Non-framework aluminum
- Rear earth
- Y zeolite