International engineering consultancy Penspen has been awarded a project by National Gas Transmission (NGT) to explore the effects of oxygen as an inhibitor for pipeline embrittlement as the operator develops a national H₂ pipeline network.

The project, which has been funded by OFGEM’s Network Innovation Allowance (NIA), will investigate whether oxygen is an effective and practical solution for inhibiting H₂ embrittlement. It is well established that H₂ embrittles pipeline steel, causing undesirable changes to key mechanical properties, such as decreasing fracture toughness and ductility, whilst increasing fatigue crack growth rate.

As owner and operator of the 5,000-mile National Transmission System (NTS), National Gas are developing a 1,500-mile H₂ transmission system, comprised of repurposed natural gas pipelines and a new H₂ pipeline network, that will build the capability and flexibility required to transport H₂ across Great Britain, supporting energy security and decarbonization of hard-to-abate industrial sectors.

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, United Arab Emirates. Engineers will focus on identifying and addressing critical concerns related to the deployment of oxygen inhibition to enable informed decision-making on how to progress this innovative technology further. 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.

Dominic Wynne, Regional Business Development Manager at Penspen, said, “With our experience supporting operators with H₂ infrastructure projects, mechanical testing programs, and process equipment design, Penspen are uniquely placed to support National Gas with this innovative project.

“The results will play a critical role in defining an optimized operating window in both new and repurposed pipelines, supporting the transition to low-carbon energy.”

Robert Best, Innovation Engineer at National Gas, said, “Gas inhibitors have the potential to optimize the efficiency of pipeline networks containing H₂ 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.”