Optimising the regeneration of sodium borohydride for solid-state green hydrogen

August 21st, 2023

R&D Focus Areas:
Hydrides, Energy systems integration

Lead Organisation:
Curtin University

Future Energy Exports CRC


Start date:
April 2023

Project summary description:
Hydrogen export has been identified as a lucrative market for Australia to replace traditional oil and gas export. As the world transitions towards cleaner energy solutions to combat the energy crisis, it is vital to investigate viable ways to store and transport hydrogen.

Sodium borohydride (NaBH4) has been identified as a suitable hydrogen storage material due to its high hydrogen content, stability at room temperature, and ability to control hydrogen generation. As NaBH4 is a stable white powder it can be safely transported via ship making it suitable for export. Once the NaBH4 is at its destination, water can be added in the presence of a metal catalyst to release hydrogen, which could be used directly or to power fuel cells. The by-product sodium metaborate (NaBO2) can be returned via ship to Australia, where it can be regenerated into NaBH4 via a reduction reaction to successfully close the loop and reduce the raw material requirements.

Unfortunately, expensive processing techniques make NaBH4 currently too costly to commercialise. Reducing the costs and increasing the yield of the regeneration step could make NaBH4 a viable hydrogen storage material.

This research focuses on the regeneration process to make NaBH4 commercially viable for hydrogen export. Successful regeneration would reduce the requirement to replenish the raw materials and can reduce the need of the expensive synthesis processes. Existing regeneration methods primarily focus on thermochemical, mechanochemical and electrochemical methods. These methods are often energy intensive or produce low yields.

This work aims to identify new cost-effective regeneration systems which could be powered by renewable energy sources to eliminate the emission of greenhouse gases to ensure that green hydrogen is exported.

Further information:
21.RP2.0166 Optimising the regeneration of sodium borohydride for solid-state green hydrogen – Future Energy Exports CRC (www.fenex.org.au)


Reviewed: August 2023