Session: CS-02-01 Hydrogen Effects on Material Behavior for Structural Integrity Assessment-Assessment of Pipelines

Paper Number: 122689

122689 - Feasibility Journey – Fitness for Service Assessment of Pipeline Materials in Repurposing Existing Natural Gas Pipelines to Transport Hydrogen – Natural Gas Blends 

Repurposing existing energy systems to low carbon sources is a necessary step toward decarbonization of the energy systems, since it provides opportunities for time and cost-efficient transition overcoming the high cost of and public resistance to building new infrastructures. As part of such transitions, existing natural gas networks are being evaluated for compatibility with transporting hydrogen – natural gas (H₂ – NG) blends, as a steppingstone to potentially transport 100% hydrogen.

Considering change of service from natural gas to hydrogen, or H₂-NG blend, requires evaluating the fitness for purpose of the system for the planned operating conditions to support a safe and reliable transition. This repurposing assessment should consider the potential impact of hydrogen on mechanical properties of the material (hydrogen embrittlement (HE)), which has been one of the main areas of investigation focusing on the boundaries where the existing materials are susceptible to hydrogen. Additionally, impacts to Safety, Risk, and Integrity management should be assessed. However, there is a lack of guideline on utilizing the existing data on HE toward re-defining the operating conditions and determining the remaining life of the existing pipeline when transitioning to H₂/NG. The current paper discusses the challenges which should be considered in the Fitness-for-Service (FFS) assessment of an existing pipeline including, inline inspection (ILI) compatibility, flaw detection, re-assessment/re-evaluation for FFS, revised remaining life, options for pressure reduction to enable H2 blending or transport.

Presenting Author: Saba Esmaeely DNV

Presenting Author Biography: Saba received her PhD in Chemical Engineering from Ohio University in 2017 with the focus on aqueous CO2/H2S corrosion. During her Postdoctoral Research at The Ohio State University, she studied hydrogen embrittlement on steel as well as other materials. She joined DNV in 2021 and now holds the role of “Senior Engineer – Hydrogen” based in Philadelphia. Hydrogen preparedness and hydrogen impact studies are just two areas where Saba focuses her expertise. She is an active member of AMPP (previously knows ad NACE International) chairing sessions related to hydrogen and volunteers her time with Big Brothers Big Sisters of America

Authors:

Saba Esmaeely DNV
Thomas Joseph Prewitt DNV
Shane Finneran DNV