Materials Selection and Performance Criteria for Hydrogen Pipeline Transmission

As a part of worldwide Hydrogen Fuel Initiatives, hydrogen fuel cell technology (US DOE 2003) is being championed as a viable resource while at the same time recognizing that the production, transmission and end use distribution of hydrogen gas will be the most critical elements. The application of fuel cell technology when fully developed is expected to dominate power and auto industries worldwide. As the demand for hydrogen increases, issues related to the safe design and economic construction of hydrogen supply and transportation infrastructure will emerge as critical path items requiring serious consideration. One of the barriers for viable hydrogen economy is that the current guidelines in various codes and standards and regulations are not adequate for the required service conditions for hydrogen transportation and delivery. Thus is the requirement for Multi-Year Research, Development and Demonstration Plan (MYPP) for the development of codes and standards to support hydrogen economy, (US DOE, 2002 & 2003). Although for many decades within the chemical industry, hydrogen in various forms has been transported by various modes, including pipelines, tank cars, mobile re-charges etc., the service conditions and transport requirements are significantly different when developing more economical methods for large volume hydrogen transportation. As industry moves quickly to implement an economical and effective pipeline infrastructure, either with new construction or by converting existing pipeline, understanding of material selection and performance, joining/welding, and establishing consensus for codes and standards are critical. Additionally, government regulations must be developed to ensure acceptable safety levels and public acceptance. The purpose of this paper is to identify current materials used in hydrogen service, their applicability and limitations, and to develop materials selection and performance criteria for designing safe hydrogen pipeline transmission infrastructure to support the development of hydrogen codes and standards, initiated by ASME (2003). Additionally, some critical future materials research areas are identified. In particular, this paper will give attention to higher strength pipeline steels (i.e. API 5LX Grade 65 and higher), quenched and tempered steels, stainless steels, as well as those alloy steels used for pressure vessels and piping. Recent development of composite reinforced line pipe (CRLP™) has the potential as viable alternative to use of very high strength thermo-mechanically treated line pipe steels, but many issues related design parameters, construction and maintenance require research and development.