Unitized bifunctional electrochemical hydrogen pumps for hydrogen-enriched natural gas

Abstract

The large-scale adoption of hydrogen energy faces significant challenges in distribution and delivery. Hydrogen-enriched natural gas (HENG) pipelines offer a cost-effective alternative. This study introduces unitized bifunctional electrochemical hydrogen pumps (UBEHPs) capable of both extracting hydrogen and generating electricity from gas mixtures with as little as 10 vol % hydrogen. Using a poly(phenylene)-based ion-pair membrane, a protonated phosphonic acid ionomer, and a commercial carbon-supported platinum catalyst, the UBEHPs achieve a bifunctional efficiency of 56% along with excellent cycling stability. A techno-economic analysis shows an 8% cost advantage over conventional systems that use separate hydrogen pumps and fuel cells. Furthermore, integrating UBEHPs with HENG pipelines can reduce hydrogen refueling station costs by 43% compared to liquid hydrogen delivery, offering a highly efficient and economically viable solution for hydrogen distribution.