Separation of helium from gases using the synthesized hydroxy sodalite membrane

The goals of this work are to synthesize and evaluate the potential of hydroxy sodalite membrane in the separation of helium from natural gas. sodalite membrane as synthesized via direct hydrothermal method (conventional heating) on tubular alumina support. it was characterized by x-ray diffraction (xrd), scanning electron microscopy (sem), and single gas permeation using helium and n2. after drying the membrane, permeances of the single gases were found to be of the order helium > ch4 > n2 > co2 at low temperatures and the membrane was impermeable to n2, co2, and ch4 at high temperatures (> 85°c). in the investigated range of temperature 35-180°c, membrane performance tended to high selectivity. the maximum separation factors (helium/n2 ~ 8.8, elium/co2 ~ 16.5 and helium/ch4 ~ 5) with acceptable permeance were observed at 85°c.