Rethinking the Future of Hydrogen Transport in Pipelines Using an Advanced Liner Material

Abstract The aging pipeline infrastructure in the United States raises concerns about potential greenhouse gas leaks, corrosion damage, and catastrophic failures. Many pipelines are 30 to 60 plus years in service with an average age of over 40 years. The three main causes of pipeline gas interruption are material or weld failure, corrosion, and excavation damage. As pipelines age, these risks increase. In addition, there is increased interest in repurposing the existing pipeline networks for hydrogen and hydrogen-methane blends. Refurbishment of existing pipelines to prevent corrosion damage, and subsequent gas leaks and preparation for hydrogen transport will significantly accelerate decarbonization efforts. Traditional approaches to refurbishing existing pipelines utilize coatings such as fusion bond epoxy or polymer-based liner. These materials provide corrosion protection but are difficult to install on active natural gas networks without significant service interruption. Often sections of pipe need to be removed for offsite repair and refurbishment. In this paper, the authors present a novel smart liner technology that is designed for on-site installation in existing natural gas pipelines. The goal of the liner is to be installed without pipe removal, avoiding major interruptions to gas service. This paper presents an in-depth investigation into the development of an advanced liner technology with thorough characterization of the various layers of material involved and the performance against corrosion and hydrogen. The liner material, with various topcoats for corrosion prevention, was evaluated using linear polarization and electrochemical impedance spectroscopy under a CO2-saturated 3.5wt% NaCl solution. Corrosion studies demonstrated an advanced nanocomposite omniphobic surface treatment with a corrosion rate of 0.5x10−6mm/year at a thickness of ~20µm. In addition, the omniphobic treated liner showed strong adhesion strength and resistance against folding/bending. Refurbishment, repair, and transformation of natural gas pipeline networks require new technologies that enable modification with limited interruption to the gas transport at a fraction of the cost of new metal pipelines. The advanced composite liner technology presented here offers a unique solution aimed at overcoming existing installation challenges for corrosion prevention, H2 transport, and leak mitigation.