Membranes Applications in GS

The key factors to qualify the performance of a specific membrane material for GS applications are the permeability and the selectivity. It is generally recognized that there is a trade-off limitation for polymeric materials between these two parameters as selectivity increases, permeability decreases and vice versa. Robeson showed such empirical upper-bound relationships for different gas separations, in 1991 [8]. In 2008, Robeson [30] published an upload of these trade-off diagrams. This diagram virtually summarized all the existing membrane materials, giving an indication of the best performance achievable (at present) by a polymeric membrane material for a specific gaseous mixture. 

The upper bound correlation follows the relationship that is valid in double logarithmic scale  

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