Process for making crystalline siliceous materials
US4900529A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1985 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Dec 23, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2229/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
ZSM-5 crystallites are produced with very low levels of blocking tetrapropyl ammonium ions (Q). The reaction mixture contains sources of silica, soda, alumina and trace amounts of Q ions as nucleation agents. Because the crystallites as synthesized from the aqueous medium exhibit only a very small fraction of blocking cations, there is always a diffusion path for the hydrated sodium ions to be exchanged without the need of prior removal of the blocking cations by calcination or otherwise. The small size crystallites can be exchanged, blended with other materials, and formed into catalyst particles. The silica to alumina ratio can be varied and when no aluminum is added, silicalite may be formed. The systhesis can be done in 24 hours or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.