Scalable and efficient separation of hydrogen isotopes using graphene-based electrochemical pumping

TL;DR

This paper presents a scalable graphene-based electrochemical method for hydrogen isotope separation that significantly reduces energy consumption and could replace energy-intensive current technologies in heavy-water production.

Contribution

The authors develop a scalable graphene CVD membrane approach achieving high isotope separation with low energy use, suitable for industrial application.

Findings

Proton-deuteron separation factor of about 8.

Projected energy consumption orders of magnitude lower.

A 30 m² graphene membrane could match modern heavy-water output.

Abstract

Thousands of tons of isotopic mixtures are processed annually for heavy-water production and tritium decontamination. The existing technologies remain extremely energy intensive and require large capital investments. New approaches are needed to reduce the industry's footprint. Recently, micron-size crystals of graphene were shown to act as efficient sieves for hydrogen isotopes pumped through graphene electrochemically. Here we report a fully-scalable approach, using graphene obtained by chemical vapor deposition, which allows a proton-deuteron separation factor of ca. 8, despite cracks and imperfections. The energy consumption is projected to be orders of magnitude smaller with respect to existing technologies. A membrane based on 30 m2 of graphene, a readily accessible amount, could provide a heavy-water output comparable to that of modern plants. Even higher efficiency is expected for tritium separation. With no fundamental obstacles for scaling up, the technology's simplicity, efficiency and green credentials call for consideration by the nuclear and related industries.