Microporous Crystalline Molecular Sieve Membranes for Molecular Gas Separations: What Is Next?

Different microporous crystalline molecular sieve compositions including zeolites (pure inorganic framework), metal organic frameworks (hybrid framework), and porous organic cages (pure organic framework) among others have been demonstrated to be very effective in separating industrially relevant challenging gas mixtures. The separation mechanisms of different gases over these membranes have been discussed previously. These mechanisms mainly include two contributions: thermodynamic and kinetic. Depending on the type of framework and gas, each contribution can be dominant. The question is which are the pressing issues that the scientific community needs to focus on to take these membranes to the next step. Herein, I discuss some important aspects that require attention to these membranes for their potential deployment. These aspects include mainly membrane reproducibility, scalability, performance under realistic conditions, and overall techno-economic analysis.