Rocket test operations at NASA Stennis Space Center (SSC) result in substantial quantities of hydrogen gas that is flared from the facility and helium gas that is vented. One way to save on the cost of test operations is to recover these gases using an electrochemical system. This Hydrogen Recovery System (HRS) selectively removes hydrogen from the mixed stream, leaving behind high-value helium. The system then removes residual water vapor from this helium and compresses it to commercial storage pressure. The heart of the HRS is a system platform under commercial development by Sustainable Innovations, termed H2RENEWTM, an electrochemical system package that separates and compresses hydrogen using Proton Exchange Membrane (PEM) technology. The system being developed in this Phase II STTR program targets a hydrogen removal rate of 1.77 scfm, an outlet hydrogen pressure of 200 psi, and a product helium pressure of 2,000 2,500 psi. This system leverages a robust novel Expandable Modular Architecture (EMA) electrochemical cell stack that is capable of being constructed with a very large production capacity and high operating pressure.

The emergence of hydrogen-based economy necessitates the ability to pump and compress large amounts of hydrogen. A range of products based on the HRS will help deliver hydrogen to fueling stations and provide compression for vehicular refueling. Assuming the adoption of a pipeline hydrogen-based infrastructure, there is a need to pump the hydrogen along the pipeline to fueling stations. A medium to large size fueling station would require 300 lbs per day of hydrogen, which at 500 psi is 1,730 cf. A 30 CFM HRS would allow a fueling station to store a day's worth of fuel in 2 hours. Hydrogen powered vehicles require hydrogen at 6,000 10,000 psi to facilitate efficient volumetric storage. Therefore an HRS with a high capacity, high pressure cell design would be a valuable tool to support a hydrogen-based economy.

There are several NASA applications that can take advantage of the underlying technologies that support Sustainable Innovations' HRS. Primary needs are to separate and recover hydrogen and helium from rocket engine test stands. For in-situ resource utilization there are needs for recirculation of hydrogen and to facilitate pneumatic transport. Terrestrial NASA applications include capturing, purifying and compressing purge gas for various experimental test stands. The requirement to separate hydrogen from CO2 and CO exists in life support applications. The HRS being developed here supports efficient separation of these constituents without moving parts. Hydrogen/oxygen fuel cell systems are being studied as a means of providing efficient energy storage for many different NASA missions. Long-term missions are hampered by the fact that residual helium often exists in the hydrogen fuel tanks. An HRS can alleviate this problem by removing the helium.