New study exploring oxygen as possible solution to hydrogen pipeline embrittlement

December 15, 2025, by Nadja Skopljak

Great Britain’s National Gas Transmission (NGT) has appointed London-headquartered engineering consultancy Penspen to explore whether oxygen can act as an effective inhibitor for hydrogen embrittlement, seen as one of the major challenges in repurposing and constructing pipelines for a future hydrogen network.

The technical study, which supports NGT’s plan to repurpose parts of the National Transmission System (NTS) and establish a future hydrogen backbone for Great Britain, will assess oxygen and alternative inhibitors, investigate delivery mechanisms, and outline a roadmap for validation and implementation, helping shape future standards and operational approaches for both repurposed and new hydrogen assets.

Funded by Ofgem’s Network Innovation Allowance (NIA), the project will be delivered from Penspen’s Newcastle office, supported by members of the company’s Centre of Engineering Excellence based in Aberdeen, Scotland, and Abu Dhabi, UAE.

“Gas inhibitors have the potential to optimise the efficiency of pipeline networks containing hydrogen by enabling higher operating pressures plus larger, and more frequent, pressure variations, conferring substantial benefits to pipeline operators. However, significant challenges remain with regards to the implementation of this technology. We are pleased to partner with Penspen on this multidisciplinary project exploring the viability of such technologies for the National Transmission System,” said Robert Best, Innovation Engineer at National Gas.

Engineers will focus on identifying and addressing critical concerns related to the deployment of oxygen inhibition to enable informed decision-making on how to further progress the technology. This includes investigating alternative gas inhibitors, identifying delivery mechanisms, including the design of a dosing system for oxygen injection, and a roadmap for validation and implementation.

NGT, the owner and operator of the 5,000-mile NTS, is developing a 1,500-mile hydrogen transmission system, comprised of repurposed natural gas pipelines and a new hydrogen pipeline network, that will build the capability and flexibility required to transport hydrogen across Great Britain, supporting energy security and decarbonisation of hard-to-abate industrial sectors.

“With our experience supporting operators with hydrogen infrastructure projects, mechanical testing programs, and process equipment design, Penspen are uniquely placed to support National Gas with this innovative project,” said Dominic Wynne, Regional Business Development Manager at Penspen. “The results will play a critical role in defining an optimised operating window in both new and repurposed pipelines, supporting the transition to low-carbon energy.”