Mixed matrix membranes with low silica-to-alumina ratio molecular sieves and methods for making and using the membranes

Abstract From the Canadian patent

A mixed matrix membrane is provided which comprises a continuous phase organic polymer and small pore alumina containing molecular sieves dispersed therein. The molecular sieves have a silica-to-alumina molar ratio of less than 1.0 more preferably, less than 0.3, and most preferably less than 0.1. In some cases, the molecular sieves have no appreciable amounts of silica. Exemplary compositions include aluminophosphates (AIPO) and silicoaluminophosphates (SAPO). When these molecular sieves are properly interspersed with a continuous phase polymer, the membrane will exhibit a mixed matrix membrane effect, i.e. a selectivity increase of at least 10% relative to a neat membrane …