State-of-the-Art Review of Using Composite Pipes for Hydrogen Transmission

Non-metallic composite pipes are increasingly being used or considered as an alternative for metallic pipe in numerous conventional and low carbon oil and gas applications, such as hydrogen transmission. The use of composite pipes can be in stand-alone pipelines, or as an internal liner to retrofit existing steel pipeline networks. The growth in the use of composites in recent years is being driven by lower material and installation costs as compared to conventional welded steel pipelines, reduced corrosion concerns, and higher operational performance metrics. It can be manufactured in long continuous lengths and spooled on reels for transport. These features can significantly reduce material and transport cost, labor, and numerous logistic concerns related to pipe procurement and pipeline construction. While interest in using and deploying composites is growing, there are unknowns in its long-term durability, inspection and condition monitoring methods, and safety when used in higher pressure applications. In this paper, the materials, design, and construction of composite pipes will be described. The subtleties of different types of composite pipes, such as reinforced thermoplastic pipe (RTP), thermoplastic composite pipe (TCP), and fiber-reinforced plastics (FRP) pipe, will be explained. Safety hazards related to hydrogen transmission will be identified. These will include hazards related to the pipeline facilities, people, and the surrounding environment. A summary of an extensive literature review of private and public efforts and a broad canvassing and surveying of material suppliers, composite pipe manufacturers, pipeline operators, and regulatory agencies will be included. Information from technical journal articles, industry publications, manufacturing marketing materials, conference proceedings, media and news sources, and U.S. national lab reports will be included as well. Standards and codes that address the hazards will be named, and remaining gaps in them will also be discussed. This paper concludes with examples of full-scale demonstrations of using polymer pipes for hydrogen distribution or transmission. The consensus of the studies available is that hydrogen is relatively inert to rigid polymer materials at the temperature and pressures recommended by pipe manufacturers. However, permeation through the wall occurs and needs to be accounted for as part of energy lost and as a safety consideration for where it collects. Also, some pipes will come with a 50-year rating, yet no composite pipes have been aged for that long, so accelerated aging techniques need to be validated to show representative short-term data. The outcome of this work will reveal the testing still required for safe hydrogen transmission composite pipe manufacture, installation, operation, inspection, repair, and rehab.