Supported SOD membrane with steam selectivity by a two-step repeated hydrothermal synthesis

By a two-step repeated hydrothermal synthesis, supported SOD membranes have been prepared. Compared with LTA membranes, SOD membranes are more stable and can be used in the removal of steam in catalytic membrane reactors in the presence of other species like H2, CH4 and CO2 in the feed or retentate. Under practice-relevant conditions, the mixture separation factors for equimolar mixtures of steam with possible reactants and products have been evaluated between 125 and 200 °C. The mixed gas separations factors for H2O/H2, H2O/CH4, and H2O/CO2 were found to decrease slightly with increasing temperatures from 125 to 200 °C and decrease from 8.1 to 4.6, from 17.9 to 14.5, and from 33.4 to 22.6, respectively. For the water separation from methanol a mixture separation factor of 200 was found.