(40c) Risk Management and Planning for Hydrogen Fuel Processes

As the world continues to shift its focus toward cleaner, more renewable sources of energy, governments and manufacturers have begun looking toward hydrogen as both a method of storing energy and for use as a cleaner fuel. Utilizing hydrogen for these purposes poses a unique set of risks and challenges due to the physical properties, chemical reactivity, and flammability of hydrogen. The primary focus of this paper will be to analyze developments in the safe use of hydrogen as a fuel source in industry, primarily as it relates to process safety concerns, and the standards associated with safe hydrogen use.

The paper will briefly introduce current industries and processes that use or are being investigated for use of hydrogen as a fuel source. The different application of hydrogen fuel within these areas, along with areas of current and future expansion within the hydrogen energy industry will be discussed.

The paper will go on to discuss mechanical concerns related to the presence of hydrogen within systems including embrittlement, high temperature hydrogen attack (HTHA), and leaking. It will go on to discuss the mechanisms through which these issues occur, the different conditions that they present under, and how they can impact process safety. This section of the paper will include an overview of hydrogen flammability concerns related to its use as a fuel. Two specific hydrogen related incidences in industry will be presented to highlight the existence of these concerns in real world application. This will include the Tesoro Anacortes refinery explosion (Tesoro Anacortes 2014-May-1 (csb.gov)) and the AB Specialty Silicones explosion (AB Specialty Silicones, LLC | CSB). These events will highlight ways in which hydrogen can pose a significant risk to safety and will be used to reiterate the associated concerns and highlight the safety lessons learned from these incidents.

The analysis of these incidents will transition into an overview of hydrogen process safety, briefly reiterating the major concerns related to storing and using hydrogen as a fuel and then moving onto safety best practices, hazard analysis, and hazard mitigation in systems using hydrogen fuel. Some of the main standards that will be referenced are the Chemical Gas Association’s (CGA) G-5.5 – Standards on Hydrogen Venting, and NFPA 2 – Hydrogen Technologies Code. The Pacific Northwest National Laboratory’s (PNNL’s) guidance on hydrogen process safety will also be referenced, namely PNNL-30457 – Example Safety Plan for Hydrogen and Fuel Cell Projects and PNNL-25279-3 – Safety Planning For Hydrogen Fuel Cell Projects. This section will include the proper methodology and important considerations and assumptions associated with performing hazard assessments or Process Hazard Analyses on these processes.

Further resources for hydrogen safety from the American Institute of Chemical Engineers’ (AIChE) Center for Hydrogen Safety, which acts as a centralized source of guidance on hydrogen safety, will also be discussed.

Next, the standards used for testing, and ensuring material, and component reliability for hydrogen systems, including embrittlement resistance testing and leak testing will be discussed as highlighted in specific NACE and ISO standards. (NACE TM0284-2003 - Resistance to Hydrogen-Induced Cracking, ISO 11114-4:2005 – Test Methods for Selecting Metallic Materials Resistant to Hydrogen Embrittlement.

Specific feasibility studies and research projects are still ongoing to further understand the safety concerns for expanded use of hydrogen in industrial setting. This paper will conclude by discussing these current efforts, looking into several current projects and the safety concerns they are addressing. This includes work being done in the United Kingdom on their H21 hydrogen scale up project and efforts related to the US Department of Energy’s H2@Scale initiative project (H21-Phase-1-Technical-Summary-Report_ES.pdf, H2@Scale | Department of Energy).