Synthesis and use of aluminophosphates and silicoaluminophosphates
AssigneeExxonMobil Chemical Patents Inc.
InventorsMachteld M. Mertens, Marcel J. G. Janssen, Teng Xu
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Abstract
Disclosed are methods and compositions of synthesis mixtures for the synthesis of aluminophosphates and silicoaluminophosphate molecular sieves, which enable the control and adjustment of the crystal particle size of aluminophosphates and silicoaluminophosphate molecular sieves. The synthesis mixture compositions used have two or more organic templates present at a molar ratio of total template to aluminum of ≦1.25; such a synthesis mixture is susceptible to control of product particle size through variation in the amount of seeds used in the synthesis.
Claims71
A method for preparing silicoaluminophosphate molecular sieves of CHA framework type, the method comprising:
- (a) forming a synthesis mixture comprising a source of aluminum, a source of phosphorus, at least two organic templates R1 and R2, a source of silicon, and colloidal seeds in an amount selected to form crystalline molecular sieves having a desired crystal size, wherein R1 comprises tetraethyl ammonium compounds, R2 is a compound selected from the group consisting of dipropylamine, isopropylamine, cyclohexylamine, methylbutylamine, morpholine, diethanolamine, trimethylethylenediamine, triethylamine, and compounds containing N, N-dimethylamino moieties, and the molar ratio of organic template (R1+R2) to aluminum (Al) in the synthesis mixture is ≦1.1;
- and
- (b) forming silicoaluminophosphate crystalline molecular sieves of CHA framework type and desired crystal size from the synthesis mixture.
A synthesis mixture for the manufacture of a silicoaluminophosphate molecular sieve of CHA framework type which is capable of providing crystals of differing crystal size and crystal size distribution through variation of seed concentration in the synthesis mixture, the synthesis mixture comprising a source of aluminum, a source of phosphorus, colloidal seeds in an amount selected to form crystalline molecular sieves having a desired crystal size, at least two organic templates R1 and R2, and a source of silicon, R1 comprising tetraethyl ammonium compounds, R2 being a compound selected from the group consisting of dipropylamine, isopropylamine, cyclohexylamine, methylbutylamine, morpholine, diethanolamine, trimethylethylenediamine, triethylamine, and compounds containing N, N-dimethylamino moieties, and the organic templates being present in a molar ratio of template (R1 +R2) to aluminum (Al) of ≦1.1.
A method of making olefin product, the method comprising providing a crystalline silicoaluminophosphate molecular sieve of CHA framework type and desired crystal size and contacting a feedstock comprising at least one oxygenate with the crystalline molecular sieve to form olefin product, wherein the step of providing the crystalline molecular sieve comprises:
- (a) forming a synthesis mixture comprising a source of aluminum, a source of phosphorus, at least two organic templates R1 and R2, a source of silicon, and colloidal seeds in an amount selected to form crystalline molecular sieves having a desired crystal size, wherein R1 comprises tetraethyl ammonium compounds, R2 is a compound selected from the group consisting of dipropylamine, isopropylamine, cyclohexylamine, methylbutylamine, morpholine, diethanolamine, trimethylethylenediamine, triethylamine, and compounds containing N, N-dimethylamino moieties, and the molar ratio of organic template (R1+R2) to aluminum (Al) in the synthesis mixture is ≦1.1;
- and
- (b) forming the crystalline silicoaluminophosphate molecular sieve of CHA framework type and desired crystal size from the synthesis mixture.
Dependencies are inferred from the claim text.