Patent ID: 7247287

Claim:
A process for preparing low acidity crystalline silicoaluminophosphate molecular sieve of CHA framework type, the process comprising: (a) providing a synthesis mixture comprising a source of aluminum, a source of phosphorus, a source of silicon and at least one organic template of formula (I) R 1 R 2 N—R 3 (I) wherein R 1 and R 2 are independently selected from the group consisting of alkyl groups having from 1 to 3 carbon atoms and hydroxyalkyl groups having from 1 to 3 carbon atoms; and R 3 is selected from the group consisting of 4- to 8-membered cycloalkyl groups, optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms; and 4- to 8-membered heterocyclic groups having from 1 to 3 heteroatoms, said heterocyclic groups being optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms and the heteroatoms in said heterocyclic groups being selected from the group consisting of O, N, and S; and (b) inducing crystallization of crystalline silicoaluminophosphate molecular sieve which is 90% or greater of CHA framework type from the synthesis mixture, wherein the Si/Al ratio in said molecular sieve after calcination is less than 0.167.