Repurposing Existing Natural Gas Pipelines for the Transmission of Hydrogen

Abstract

Abstract As the global energy community moves towards the adoption of hydrogen and Natural Gas blends as a potential alternative to existing carbon-rich fuel, it is vital to develop the necessary infrastructure to accommodate hydrogen as a fuel and energy carrier of the future. Newer infrastructure is extremely cost-prohibitive and will significantly delay global decarbonization efforts. Transformation of existing infrastructure in handling hydrogen-based gas blends is the first step in achieving the targeted decarbonization goals. Although existing natural gas pipelines may be suited for transporting hydrogen-natural gas blends, they are also vulnerable to leaks, embrittlement, and hydrogen-induced cracking, especially on newer high-strength steel (X70 or higher). This paper presents a new approach to preparing existing natural gas infrastructure for potential hydrogen-natural gas blends by protecting vulnerable steel surfaces with an advanced nanocomposite surface treatment. It remains, however, that understanding the impact of cyclic stress, fatigue, and the effect of hydrogen concentration on steel and surface-treated steel is vital to refining and advancing surface protection approaches. To evaluate field operation conditions, a new experimental facility was set up, capable of conducting high pressure (up to 4000 psi) and high temperature (up to 572°F) testing following ASTM G142. High-pressure testing at 2000 psi in hydrogen blends indicates that the surface treatment has a strong barrier effect and demonstrated a reduction in the susceptibility to embrittlement under hydrogen. In addition, surface-treated coupons were installed in a commercial natural gas transmission pipeline that transports hydrogen (up to 15%)-natural gas blends. Decarbonization requires newer technologies that are designed to transform the current state-of-the-art energy infrastructure with minimal impact and at a rapid scale. The nanocomposite surface treatment presented here offers a highly scalable solution of in-place treatment of existing natural gas pipeline infrastructure to accelerate hydrogen-natural gas transportation and promote the use of low-carbon energy carriers for the energy industry and its end customers.