Method of synthesizing aluminophosphate and silicoaluminophosphate molecular sieves
View Patent ↗In a method of synthesizing an aluminophosphate or silicoaluminophosphate molecular sieve, a synthesis mixture is prepared by mixing a plurality of starting materials including at least a source of water, a source of phosphorus, a source of aluminum, optionally, a source of silicon and, and at least one organic directing agent for directing the formation of said molecular sieve. The starting materials are maintained at a temperature between 25° C. and 50° C., preferably between 30° C. and 45° C., during the mixing and until preparation of the starting mixture is complete, whereafter the synthesis mixture is heated to a crystallization temperature between about 100° C. and about 350° C. until crystals of the molecular sieve are produced. When crystallization is complete, the molecular sieve is recovered.
1. A process for converting an organic oxygenate starting material into a product comprising olefins or alkylamines, the process comprising contacting the starting material with a catalyst comprising a crystalline aluminophosphate or silicoaluminophosphate molecular sieve of the CHA framework-type which has a particle size distribution such that its (d 90 −d 10 )/d 50 ratio is less than 1.
2. The process of claim 1 , wherein the process comprises the conversion of aliphatic alcohols and/or ethers to olefins.
3. The process of claim 1 , wherein the process comprises the conversion of an organic oxygenate to olefins and the olefins are then polymerized.
4. The process of claim 1 , wherein the crystalline silicoaluminophosphate molecular sieve is synthesized by a method comprising:
(a) (i) mixing at least a source of water and a source of aluminum with a source of phosphorus to form a synthesis mixture,
(ii) adding a source of silicon to the synthesis mixture, and
(iii) adding at least one organic directing agent for directing the formation of said molecular sieve to the synthesis mixture;
(b) maintaining said synthesis mixture at a temperature between 29° C. and 44° C. from the moment the source of phosphorus is completely added into said synthesis mixture;
(c) heating said synthesis mixture to a crystallization temperature between about 100° C. and about 350° C. until crystals of said molecular sieve are produced; and
(d) recovering said molecular sieve crystals.