H2 permeation and its influence on gases through a SAPO-34 zeolite membrane

This work analysed the permeation of binary and ternary H-containing mixtures through a SAPO-34 membrane, aiming at investigating how hydrogen influences and its permeation is influenced by the presence of the other gaseous species, such as CO and CH. We considered the behaviour of various gas mixtures in terms of permeability and selectivity at various temperatures (25-300 °C), feed pressures (400-1000 kPa) and compositions by means of an already validated mass transport model, which is based on surface and gas translation diffusion. We found that the presence of CO and CH in the H-containing mixtures influences in a similar way the H permeation, reducing its permeability of about 80% compared to the single-gas value because of their stronger adsorption. On the other hand, H promotes the permeation of CO and CH, causing an increment of their permeability with respect to those as single gases. These combined effects reflected in interesting selectivity values in binary mixture (e.g., CO/H about 11 at 25 °C, H/CH about 9 at 180 °C), which showed the potential of SAPO-34 membranes in treating of H-containing mixtures.