Critical Review of Helium Purification Techniques for Lighter-than-Air Systems

摘要

Helium is the most popular gas used in Lighter-Than-Air (LTA) systems, and keeping in mind its high cost and limited availability, it is important to study the various methods of purifying and extracting it. This paper provides an overview and brief description of the three most common approaches for Helium filtration and purification, viz., adsorption, cryogenic and membrane based methods, and discusses their cost-effectiveness and scalability. Details of an on-board Helium purification system, as well as a ground based Helium recovery system are also presented. In the end, a case study of a combination of cryogenic and adsorption process implemented in a laboratory set-up is also presented.