Allowable Hydrogen Permeation Rates in Non-Metallic Pipelines for Typical Application Scenarios

The burgeoning hydrogen energy sector necessitates the development of safe and efficient hydrogen transportation systems. Non-metallic pipelines, poised to play a significant role in this sector, have been the subject of extensive research focusing on their barrier properties against hydrogen permeation. However, a critical gap exists in defining the permissible hydrogen leakage rates that ensure safety without compromising functionality. This paper addresses this gap by proposing a framework for determining the acceptable hydrogen permeation rates in non-metallic pipelines. The hydrogen permeation rates in non-metallic pipelines across various application scenarios, i.e. in residential settings, buried applications, and confined spaces like utility corridors, are evaluated, and the relationship between hydrogen permeation rates and critical factors such as spatial configuration, environmental ventilation, and burial conditions are quantified. The results allow for the establishment of safety thresholds tailored to specific application contexts, propose a method to ensure that the specifications of non-metallic pipelines meet hydrogen permeation safety requirements. This method is based on these permissible rates, including considerations of wall thickness and barrier performance. This research also offers guidance for material selection based on hydrogen permeation performance, ensuring that the pipelines are not only safe but also optimized for cost and efficiency.