Crystalline intergrowth material, its synthesis and its use in the conversion of oxygenates to olefins

A process for making an olefin product from an oxygenate feedstock comprising synthesizing a silicoaluminophosphate molecular sieve by:

• (a) preparing a mixture comprising a source of water, a reactive source of silicon, a reactive source of aluminum, a reactive source of phosphorus, and an organic directing agent for directing the formation of said molecular sieve such that said mixture has a molar composition within the following ranges:
• P2O5:
• Al2O3 from about 0.6 to about 1.2,
• SiO2:
• Al2O3 from about 0.12 to about 0.20,
• H2O:
• Al2O3 from about 25 to about 50,
• (b) agitating and heating said mixture to a crystallization temperature;
• (c) maintaining said mixture at said crystallization temperature for a period of time from about 2 to about 150 hours;
• (d) recovering said molecular sieve comprising first and second intergrown phases of a CHA framework type and an AEI framework type, wherein said first intergrown phase has an AEI/CHA ratio of from about 5/95 to about 40/60 as determined by DIFFaX analysis, said second intergrown phase has an AEI/CHA ratio of about 30/70 to about 55/45 as determined by DIFFaX analysis, and said recovered molecular sieve has a silica to alumina molar ratio (Si/Al2) in a range from 0.17 to about 0.24 ;
• and
• (e) contacting said oxygenate feedstock with said recovered silicoaluminophosphate molecular sieve to form said olefin product.