Hydrothermal conversion of Y-zeolite using alkaline earth cations
AssigneeCalifornia Institute of Technology
InventorsOsamu Chiyoda, Mark E. Davis
Life of this patent
Estimating the term…
Abstract
Hydrothermal synthesis of the natural, alkaline earth zeolites via the alteration of Y-zeolite is presented. Synthetic versions of the zeolites harmotome, heulandite, brewsterite and gmelinite are synthesized from Y-zeolite using alkaline earth cations containing solutions. The effect of the composition of the starting zeolite, the composition of the solution phase, the presence or absence of seeds and the experimental conditions are discussed.
Claims31
A method for synthesizing a zeolite, comprising the steps of:
- a) providing a Y zeolite having 2.0≦Si/Al≦3.5 and which includes an alkaline earth cation;
- and
- b) forming said zeolite under hydrothermal reaction conditions from a reaction mixture containing said Y-zeolite and aqueous solution of an alkaline earth cation.
A method for synthesizing a zeolite, comprising the steps of:
- a) providing a Y zeolite having 2.0≦Si/Al≦3.5;
- and
- b) forming said zeolite under hydrothermal reaction conditions from a reaction mixture containing said Y-zeolite and aqueous solution of an alkaline earth cation, the reaction mixture being substantially free of any zeolite directing agent.
A method for preparing synthetic heulandite, gmelinite, brewsterite, analcime or harmotome zeolite product, comprising the steps of:
- a) providing a reaction mixture containing Y-zeolite having 2.0≦Si/Al≦3.5 and an alkaline earth cation, wherein the alkaline earth cation is in a concentration greater than that of the concentration of any other metal cation present in the reaction mixture;
- and
- b) converting under hydrothermal conditions said Y-zeolite in said reaction mixture to said zeolite product containing said alkaline earth cation.
A method for preparing a zeolite having the phillipsite topology and the formula in terms of atomic ratios BaO:Al2O3:6SiO2:6H2O, comprising the steps of:
- a) providing a reaction mixture containing a first alkaline earth cation and a Y-zeolite, said Y-zeolite having 2.0≦Si/Al≦3.5 and a second alkaline earth cation, the mixture being substantially free of any other alkaline earth cations and any zeolite structure directing agent;
- and
- b) forming said zeolite from said Y-zeolite under hydrothermal reaction conditions, said zeolite incorporating a first alkaline earth cation into its framework.
A method for preparing a zeolite having the brewsterite topology and the formula in terms of atomic ratios SrO:Al2O3:5.8 SiO2:4.5 H2O comprising the steps of:
- a) providing a reaction mixture containing a first alkaline earth cation and a Y-zeolite, said Y-zeolite having 2.0≦Si/Al≦3.0 and a second alkaline earth cation, the mixture being substantially free of any other alkaline earth cations and any zeolite structure directing agent;
- and
- b) forming said zeolite from said Y-zeolite under hydrothermal reaction conditions, said zeolite incorporating a first alkaline earth cation into its framework.
A method for preparing a zeolite having the heulandite topology comprising the steps of:
- a) providing a reaction mixture containing a first alkaline earth cation and a Y-zeolite, said Y-zeolite having 2.0≦Si/Al≦3.0 and a second alkaline earth cation, the mixture being substantially free of any other alkaline earth cations and any zeolite structure directing agent;
- and
- b) forming said zeolite from said Y-zeolite under hydrothermal reaction conditions, said zeolite incorporating a first alkaline earth cation into its framework.
A method for preparing a zeolite having the gmelinite topology comprising the steps of:
- a) providing a reaction mixture containing a first alkaline earth cation and a Y-zeolite, said Y-zeolite having 2.0≦Si/Al≦2.4 and a second alkaline earth cation, the mixture being substantially free of any other alkaline earth cations and any zeolite structure directing agent;
- and
- b) forming said zeolite from said Y-zeolite under hydrothermal reaction conditions, said zeolite incorporating a first alkaline earth cation into its framework.
Dependencies are inferred from the claim text.