Patent ID: 7622624

Claim:
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: P 2 O 5 : Al 2 O 3 from about 0.6 to about 1.2, SiO 2 : Al 2 O 3 from about 0.12 to about 0.20, H 2 O: Al 2 O 3 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/Al 2 ) 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.