High-performance 19-channel monolithic chabazite membranes for efficient separation of water/ethanol and water/isopropanol mixtures by pervaporation and vapor permeation

Pervaporation (PV) and vapor permeation (VP) using selective zeolite membranes are more energy-saving in dealing with azeotropic mixtures compared with conventional distillation for organic solvent dehydration. Herein, we developed a monolithic supported chabazite membrane and exploited its dehydration performance. The membrane was fabricated by secondary growth method on the 19-channel alumina monolithic without organic template. By finely controlling the homogeneity of nuclei growth and minimizing the intracrystalline defects through the epitaxial growth of uniformly nanosized SSZ-13 seed layer using cesium hydroxide and sodium hydroxide as cooperative hydration-mismatched inorganic structure directing agents (ISDA). The resulting monolithic chabazite membrane exhibits excellent water-perm-selectivity. The effects of feed water composition and operating temperature on the dehydration performance of the monolithic chabazite membrane were investigated through PV and VP processes. The typical membrane displayed excellent selectivities of more than 10,000 and 30,000 in 10/90 wt% water/ethanol and water/isopropanol mixtures at 393 K. The membrane exhibited excellent hydrothermal stability in a VP with a 10/90 wt% water/ethanol at 393 K for 72 h. The robust monolithic chabazite membrane with high packing density, strong mechanical strength, large membrane area and excellent water-selective performance significantly outperforms state-of-the-art membranes for dehydration in practical applications.