Patent ID: 8268277
Filing Date: 2012-09-18
Classification: B01J,C01B,C07C,Y02P

Abstract:
1. A method of preparing a silicoaluminophosphate molecular sieve having a desired crystal size, the method 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 containing (i) a 4- to 8-membered cycloalkyl group, optionally substituted by 1-3 alkyl groups having from 1-3 carbon atoms, or (ii) a 4- to 8-membered heterocyclic group having from 1-3 heteroatoms, said heterocyclic group being optionally substituted by 1-3 alkyl groups having from 1-3 carbon atoms, and said heteroatoms in said heterocyclic groups being selected from the group consisting of O, N, and S, wherein the synthesis mixture exhibits a Si/Al (b) inducing crystallization of a silicoaluminophosphate molecular sieve, which exhibits 90% or greater CHA framework type character, from said synthesis mixture by heating said synthesis mixture at a heating rate of more than 20° C./hr to a crystallization temperature; and (c) crystallizing said silicoaluminophosphate molecular sieve at the crystallization temperature for between 16 hours and 350 hours, such that a yield of silicoaluminophosphate molecular sieve greater than 8.0% is attained, wherein the crystallized silicoaluminophosphate molecular sieve exhibits a Si/Al wherein step (a) comprises: