Highly Efficient Electrochemical Cryogenic Purge Gas Recovery System

Ongoing rocket test operations at NASA Stennis Space Center (SSC) result in substantial quantities of hydrogen gas that is flared from the facility in addition to valuable helium gas that is vented to the atmosphere. One method that can dramatically reduce the cost of test operations is to recover these gases using an electrochemical process. A Hydrogen Recovery System (HRS), which has recently been the subject of a highly successful Phase II SBIR conducted by Sustainable Innovations, LLC, selectively removes hydrogen from the mixed stream, leaving behind the high-value helium. In 2014 a prototype unit was successfully delivered by Sustainable Innovations to SSC to demonstrate the ability to capture, separate and compress helium from a mixture derived from test operations. The innovative step in this Phase I proposal is to increase the gas capacity capability of the electrochemical separation cell while maintaining optimal operating efficiency and durability. This will be achieved by: Implementing high electrical conductivity, high durability coatings on cell components that support operation in the hydrogen environment; Evaluating and demonstrating robust, high strength, high conductivity proton exchange membrane materials that support the separation process; and Integrating all elements within a one-piece flow field structure to minimize interfaces and facilitate coatings. It is expected that these innovative steps will allow for at least a doubling of throughput capacity per unit cell area.