NASA uses a large amount of helium gas to purge hydrogen from fuel lines during launches. A typical shuttle launch used about a million cubic feet of helium where six times this amount is expected for the space launch system and multipurpose crew vehicle launches. This helium gas contaminated with hydrogen is expensive and energy intensive to purify and recover. Because of helium shortages and rising prices, cost effective recovery and reclamation of helium from hydrogen-helium gas mixture is of great economic significance to NASA and to the nation. The present cryogenic separation process for this gas mixture is energy intensive, and newer demonstrations using proton-exchange membrane based separation processes are difficult and costly to scale to the size needed to process this large quantity of gas. Accordingly, Reactive Innovations is developing a metal membrane based micro-channel separation unit that is readily scalable and inexpensive to produce and operate. The micro-channel separation technology maximizes the separation area per unit volume giving enhanced thermal and mass fluxes to separate hydrogen from the helium mixture.
Beyond NASA's use, helium is an important irreplaceable inert gas used in a variety of scientific and industrial fields such as oil and gas detectors, the nuclear industry, medical applications, cryogenics, and welding. However, due to the growing demand for He, the market supply is becoming tighter and costs are increasing. Currently, cryogenic distillation and pressure-swing adsorption are the prevalent methods widely used for He separation, especially in natural gas feedstocks. The cryogenic distillation and pressure-swing separation methods involve complicated operations and require considerable energy consumption. Thus, there is an urgent need to develop simple, low-energy, and low-cost methods for separating He from other gases. Other potential uses for this separator unit include removing hydrogen from natural gas processing plants, and separating helium-hydrogen mixtures used in medical MRI imaging, semiconductor processing, welding, and nuclear processes.