United States

Hydrogen sensors are recognized as a critical element in the safety design for any hydrogen system. In this role sensors can perform several important functions including indication of unintended hydrogen releases activation of mitigation strategies to preclude the development of dangerous situations activation of alarm systems and communication to first responders and to initiate system shutdown. The functionality of hydrogen sensors in this capacity is decoupled from the system being monitored thereby providing an independent safety component that is not affected by the system itself. The importance of hydrogen sensors has been recognized by DOE and by the Fuel Cell Technologies Office’s Safety and Codes Standards (SCS) program in particular which has for several years supported hydrogen safety sensor research and development. The SCS hydrogen sensor programs are currently led by the National Renewable Energy Laboratory Los Alamos National Laboratory and Lawrence Livermore National Laboratory. The current SCS sensor program encompasses the full range of issues related to safety sensors including development of advance sensor platforms with exemplary performance development of sensor-related code and standards outreach to stakeholders on the role sensors play in facilitating deployment technology evaluation and support on the proper selection and use of sensors.

The unconfined release of high-pressure hydrogen can create a large flammable jet with the potential to generate significant damage. To properly understand the separation distances necessary to protect the immediate surroundings it is important to accurately assess the potential consequences. In these events the possibility for a detonation cannot be excluded and would generally result in the worst case scenario from the standpoint of damaging overpressure. The strong concentration gradients created by a jet release however raises the question of what portion of the flammable cloud should be considered. Often all of the fuel within the limits of fast-flame acceleration or even all of the fuel within the flammability range is considered which typically comprises the majority of the flammable cloud. In this work prior detonation studies are reviewed to illustrate the inherently unstable nature of detonations with a focus on the critical dimensions and concentration gradients that can support a propagating detonation wave. These criteria are then applied to the flammable cloud concentration distributions generated by an unconfined jet release of hydrogen. By evaluating these limits it is found that the portion of the flammable cloud that is likely to participate is significantly reduced. These results are compared with existing experimental data on the ignition of unconfined hydrogen releases and the peak pressures that were measured are consistent with a detonation of a mass of fuel that is equivalent to the model prediction for the mass of fuel within the detonable limits. This work demonstrates how the critical conditions for detonation propagation can be used to estimate the portion of a hydrogen release that could participates in a detonation and how these criteria can be readily incorporated into existing dispersion modelling approaches.

A key challenge for future clean power or hydrogen projects via gasification is the need to reduce the overall cost while achieving significant levels of CO2 capture. The current state of the art technology for capturing CO2 from sour syngas uses a physical solvent absorption process (acid gas removal–AGR) such as Selexol™ or Rectisol® to selectively separate H2S and CO2 from the H2. These two processes are expensive and require significant utility consumption during operation which only escalates with increasing levels of CO2 capture. Importantly Air Products has developed an alternative option that can achieve a higher level of CO2 capture than the conventional technologies at significantly lower capital and operating costs. Overall the system is expected to reduce the cost of CO2 capture by over 25%.<br/>Air Products developed this novel technology by leveraging years of experience in the design and operation of H2 pressure swing adsorption (PSA) systems in its numerous steam methane reformers. Commercial PSAs typically operate on clean syngas and thus need an upstream AGR unit to operate in a gasification process. Air Products recognized that a H2 PSA technology adapted to handle sour feedgas (Sour PSA) would enable a new and enhanced improvement to a gasification system. The complete Air Products CO2 Capture technology (CCT) for sour syngas consists of a Sour PSA unit followed by a low-BTU sour oxycombustion unit and finally a CO2 purification / compression system.

The Hydrogen Safety Codes and Standards program element of the US Department of Energy's Fuel Cell Technologies Office provides coordination and technical data for the development of domestic and international codes and standards related to hydrogen technologies. The materials compatibility program task at Sandia National Laboratories (Livermore CA) is focused on developing the technical basis for qualifying materials for hydrogen service i.e. accommodating hydrogen embrittlement. This presentation summarizes code development activities for qualifying materials for hydrogen service with emphasis on the scientific basis for the testing methodologies including fracture mechanics based measurements (fracture threshold and fatigue crack growth) total fatigue life measurements and full- scale pressure vessel testing.

The Department of Energy (DOE) Hydrogen Program Plan (the Program Plan or Plan) outlines the strategic high-level focus areas of DOE’s Hydrogen Program (the Program). The term Hydrogen Program refers not to any single office within DOE but rather to the cohesive and coordinated effort of multiple offices that conduct research development and demonstration (RD&D) activities on hydrogen technologies. This terminology and the coordinated efforts on hydrogen among relevant DOE offices have been in place since 2004 and provide an inclusive and strategic view of how the Department coordinates activities on hydrogen across applications and sectors. This version of the Plan updates and expands upon previous versions including the Hydrogen Posture Plan and the DOE Hydrogen and Fuel Cells Program Plan and provides a coordinated high-level summary of hydrogen related activities across DOE.



The 2006 Hydrogen Posture Plan fulfilled the requirement in the Energy Policy Act of 2005 (EPACT 2005) that the Energy Secretary transmit to Congress a coordinated plan for DOE’s hydrogen and fuel cell activities. For historical context the original Posture Plan issued in 2004 outlined a coordinated plan for DOE and the U.S. Department of Transportation to meet the goals of the Hydrogen Fuel Initiative (HFI) and implement the 2002 National Hydrogen Energy Technology Roadmap. The HFI was launched in 2004 to accelerate research development and demonstration (RD&D) of hydrogen and fuel cell technologies for use in transportation electricity generation and portable power applications. The Roadmap provided a blueprint for the public and private efforts required to fulfill a long-term national vision for hydrogen energy as outlined in A National Vision of America’s Transition to a Hydrogen Economy—to 2030 and Beyond. Both the Roadmap and the Vision were developed out of meetings involving DOE industry academia non-profit organizations and other stakeholders. The Roadmap the Vision the Posture Plans the 2011 Program Plan and the results of key stakeholder workshops continue to form the underlying basis for this current edition of the Program Plan.



This edition of the Program Plan reflects the Department’s focus on conducting coordinated RD&D activities to enable the adoption of hydrogen technologies across multiple applications and sectors. It includes content from the various plans and documents developed by individual offices within DOE working on hydrogen-related activities including: the Office of Fossil Energy's Hydrogen Strategy: Enabling a Low Carbon Economy the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Cell Technologies Office Multi-year RD&D Plan the Office of Nuclear Energy’s Integrated Energy Systems 2020 Roadmap and the Office of Science’s Basic Research Needs for the Hydrogen Economy. Many of these documents are also in the process of updates and revisions and will be posted online.



Through this overarching document the reader will gain information on the key RD&D needs to enable the largescale use of hydrogen and related technologies—such as fuel cells and turbines—in the economy and how the Department’s various offices are addressing those needs. The Program will continue to periodically revise the Plan along with all program office RD&D plans to reflect technological progress programmatic changes policy decisions and updates based on stakeholder input and reviews.

Hydrogen Infrastructures are currently being built up to support the initial commercialization of the fuel cell vehicle by multiple automakers. Three primary markets are presently coordinating a large build up of hydrogen stations: Japan; USA; and Europe to support this. Hydrogen Fuelling Station General Safety and Performance Considerations are important to establish before a wide scale infrastructure is established.

This document introduces the ISO Technical Report 19880-1 and summarizes main elements of the proposed standard. Note: this ICHS paper is based on the draft TR 19880 and is subject to change when the document is published in 2015. International Standards Organisation (ISO) Technical Committee (TC) 197 Working Group (WG) 24 has been tasked with the preparation of the ISO standard 19880-1 to define the minimum requirements considered applicable worldwide for the hydrogen and electrical safety of hydrogen stations. This report includes safety considerations for hydrogen station equipment and components control systems and operation. The following systems are covered specifically in the document as shown in Figure 1:

• H2 production / supply delivery system
• Compression
• Gaseous hydrogen buffer storage;
• Pre-cooling device;
• Gaseous hydrogen dispensers.
• Hydrogen Fuelling Vehicle Interface

The draft TR 19880-1 (and current plan for the standard) also gives guidance for the fueling validation with safety considerations relevant to the interaction between the hydrogen station and hydrogen road vehicles (during fuelling).. Through a cross-industry risk assessment carried out between OEMs Hydrogen Suppliers and existing vehicle fuelling station providers & operators (e.g. oil and industrial gas companies) the hydrogen fueling protocol SAE J2601 and associated dispenser hardware was evaluated."

One of the main benefits sought by including hydrogen in the alternative fuels mix is emissions reduction – eventually by 100%. However in the near term there is a very significant cost differential between fossil fuels and hydrogen. Hythane (a blend of hydrogen and natural gas) can act as a viable next step on the path to an ultimate hydrogen economy as a fuel blend consisting of 8−30 % hydrogen in methane can reduce emissions while not requiring significant changes in existing infrastructure. This work seeks to evaluate whether hythane may be safer than both hydrogen and methane under certain conditions. This is due to the fact hythane combines the positive safety properties of hydrogen (strong buoyancy high diffusivity) and methane (much lower flame speeds and narrower flammability limits as compared to hydrogen). For this purpose several different mixture compositions (e.g. 8 % 20 % and 30 % hydrogen) are considered. The evaluation of (a) dispersion characteristics (which are more positive than for methane) (b) combustion characteristics (which are closer to methane than hydrogen) and (c) Combined dispersion + explosion risk is performed. This risk is expected to be comparable to that of pure methane possibly lower in some situations and definitely lower than for pure hydrogen. The work is performed using the CFD software FLACS that has been well-validated for safety studies of both natural gas/methane and hydrogen systems. The first part of the work will involve validating the flame speeds and flammability limits predicted by FLACS against values available in literature. The next part of the work involves validating the overpressures predicted by the CFD tool for combustion of premixed mixtures of methane and hydrogen with air against available experimental data. In the end practical systems such as vehicular tunnels garages etc. is used to demonstrate positive safety benefits of hythane with comparisons to similar simulations for both hydrogen and methane.

Contrary to several reports in the recent literature the use of oxygen sensors for indirectly monitoring ambient hydrogen concentration has serious drawbacks. This method is based on the assumption that a hydrogen release will displace oxygen which is quantified using oxygen sensors. Despite its shortcomings the draft Hydrogen Vehicle Global Technical Regulation lists this method as a means to monitor hydrogen leaks to verify vehicle fuel system integrity. Experimental evaluations that were designed to impartially compare the ability of commercial oxygen and hydrogen sensors to reliably measure and report hydrogen concentration changes are presented. Numerous drawbacks are identified and discussed.

This paper introduces the 3D risk management (3DRM) concept with particular emphasis on hydrogen installations (Hy3DRM). The 3DRM framework entails an integrated solution for risk management that combines a detailed site-specific 3D geometry model a computational fluid dynamics (CFD) tool for simulating flow-related accident scenarios methodology for frequency analysis and quantitative risk assessment (QRA) and state-of-the-art visualization techniques for risk communication and decision support. In order to reduce calculation time and to cover escalating accident scenarios involving structural collapse and projectiles the CFD-based consequence analysis can be complemented with empirical engineering models reduced order models or finite element analysis (FEA). The paper outlines the background for 3DRM and presents a proof-of-concept risk assessment for a hypothetical hydrogen filling station. The prototype focuses on dispersion fire and explosion scenarios resulting from loss of containment of gaseous hydrogen. The approach adopted here combines consequence assessments obtained with the CFD tool FLACS-Hydrogen from Gexcon and event frequencies estimated with the Hydrogen Risk Assessment Models (HyRAM) tool from Sandia to generate 3D risk contours for explosion pressure and radiation loads. For a given population density and set of harm criteria it is straightforward to extend the analysis to include personnel risk as well as risk-based design such as detector optimization. The discussion outlines main challenges and inherent limitations of the 3DRM concept as well as prospects for further development towards a fully integrated framework for risk management in organizations.

RCS for hydrogen technologies were first developed approximately sixty years ago when hydrogen was being sold as an industrial commodity. The advent of new hydrogen technologies such as Fuel Cell Electric Vehicles (FCEVs) created a need for new RCS. These RCS have been developed with extensive support from the US DOE. These new hydrogen technologies are approaching commercial deployment and this process will produce information on RCS field performance that will create more robust RCS.