International engineering consultancy Penspen has secured a project with National Gas Transmission (NGT) to explore the use of oxygen as an inhibitor for pipeline embrittlement. 

The outcome of the project will be crucial in ensuring operational efficiency and safety of hydrogen pipelines as National Gas, the owner and operator of the 5,000-mile National Transmission System (NTS), develops a national hydrogen pipeline network.

Hydrogen is known to cause undesirable changes in pipeline steel, such as decreasing fracture toughness and ductility while increasing the fatigue crack growth rate. Therefore, the project, funded by OFGEM’s Network Innovation Allowance (NIA), will investigate whether oxygen is a practical solution to counter hydrogen embrittlement. 

National Gas is planning a 1,500-mile hydrogen transmission system, which will consist of repurposed existing natural gas pipelines and newly built hydrogen pipelines. This system aims to provide the capacity needed to transport hydrogen across Great Britain, bolstering energy security and aiding the decarbonization of difficult-to-abate industrial sectors.

Penspen will manage the project from its Newcastle office, supported by its Centre of Engineering Excellence teams in Aberdeen, Scotland, and Abu Dhabi, UAE. Engineers will focus on identifying key concerns related to deploying oxygen inhibition to inform decisions on the technology's future use. 

The scope includes designing a dosing system for oxygen injection, investigating alternative gas inhibitors, and developing a roadmap for validation and implementation.

Dominic Wynne, Penspen’s Regional Business Development Manager, stated the company is "uniquely placed" to support the innovative project, citing their experience in hydrogen infrastructure and mechanical testing. 

He added that the results will be "critical in defining an optimised operating window in both new and repurposed pipelines."

Robert Best, Innovation Engineer at National Gas, noted that gas inhibitors could "optimize the efficiency of pipeline networks containing hydrogen" by allowing higher operating pressures and greater pressure variations, offering substantial operator benefits.