Lifecycle Management and Technical Feasibility of Hydrogen Pipeline Infrastructure for Canada’s Clean Energy Transition

Abstract

This thesis explores the lifecycle management and technical viability of retrofitting existing natural gas pipeline infrastructure for transport in the hydrogen context of Canada’s clean energy transition. Hydrogen is widely recognized as a critical enabler in the pursuit of a net-zero emissions economy, and yet the viability of retrofitting existing pipeline infrastructure for hydrogen service remains uncertain in the face of challenges such as hydrogen embrittlement, material degradation, and a lack of standardized retrofit methodologies. To address these challenges, this study develops an integrated framework combining lifecycle management principles with Multiphysics numerical modeling. A three-dimensional finite element model is established in COMSOL Multiphysics to simulate the behavior of a buried steel pipeline under mechanical, thermal, and hydraulic loading conditions representative of Canadian environments. The modeling approach progresses from baseline geostatic conditions to fully coupled hydro-thermo-mechanical (HTM) analysis, enabling systematic evaluation of stress distribution, deformation, and environmental interaction. The results demonstrate that internal pressure is the dominant factor governing pipeline stress, with maximum von Mises stress reaching approximately 192- 197 MPa under operating conditions, remaining within acceptable limits for X52 steel pipelines. Von Mises equivalent stress is adopted as the primary structural stress indicator because it represents the combined multiaxial stress state and enables assessment of yielding in the steel pipeline, while hoop stress is used separately to evaluate the circumferential response to internal pressure. In contrast, external surcharge loading primarily influences pipe deformation and ground settlement, with displacement increasing to approximately 6-8 mm and surface settlement exceeding 10 mm under higher loading conditions. Thermal effects are found to be negligible under near-ambient steady-state conditions, while groundwater interaction contributes to increased deformation through reductions in effective soil stiffness, without significantly altering peak stress levels. The study further validates numerical results using classical analytical solutions. Management and numerical stress analysis offer a useful framework for assessing retrofit viability. In conclusion, the research makes a specific contribution to the body of knowledge on the hydrogen pipeline retrofitting framework specific to Canada and demonstrates the technical feasibility of existing buried natural gas pipelines for hydrogen transport under specified operating and environmental conditions.