Helium separation using membrane technology: Recent advances and perspectives

Helium is an unrenewable noble gas produced from natural gas with a wide range of scientific, medical, and industrial applications. Due to the large differences in the kinetic diameters between helium (0.26 nm) and nitrogen (0.364 nm) or methane (0.38 nm), membrane technology has been considered a promising alternative to traditional technologies for helium recovery and purification. This paper systematically reviews the advances in membrane material development for helium separation in recent years. Gas permeation data presented in this work were collected from over 1000 membrane materials, including polymeric, inorganic, and mixed matrix membranes. Moreover, membrane processes for helium recovery and purification from natural gas were critically analyzed and discussed concerning technical feasibility, energy consumption, and separation costs. Challenges in helium purification using membrane technology were also discussed, and potential solutions have been suggested. Lastly, future perspectives on research directions on membrane material development and hybrid helium purification process design and optimization are proposed.