Synthesis of chabazite-containing molecular sieves and their use in the conversion of oxygenates to olefins
US7754187B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2007 |
| Grant date | Jul 13, 2010 |
| Priority date | — |
| Expiry date | Sep 19, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P30/40
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method is disclosed of synthesizing a crystalline material comprising a CHA framework type molecular sieve and having a composition involving the molar relationship:(n)X2O3:YO2,wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to less than 0.01. The method comprises preparing a reaction mixture capable of forming said material, said mixture comprising a source of water, a source of an oxide of a tetravalent element Y and optionally a source of an oxide of a trivalent element X, wherein the reaction mixture is substantially free of fluoride ions added as HF; maintaining the reaction mixture under conditions sufficient to form crystals of the crystalline material; and than recovering the crystalline material. The reaction mixture comprises either a specific directing agent for directing the formation of a CHA framework type molecular sieve and/or a H2O:YO2 molar ratio of greater than 20. In one embodiment, the resultant crystalline material is free of stacking faults and/or any intergrown phase with an AEI framework type molecular sieve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.