Safety

Hydrogen may play a crucial part in delivering a net zero emissions future. Currently hydrogen production storage transport and utilisation are being explored to scope opportunities and to reduce barriers to market activation. One such barrier could be negative public response to hydrogen technologies. Previous research around socio-technical risks finds that public acceptance issues are particularly challenging for emerging remote technical sensitive uncertain or unfamiliar technologies - such as hydrogen. Thus while the hydrogen value chain could offer a range of potential environmental economic and social benefits each will have perceived risks that could challenge the introduction and subsequent roll-out of hydrogen. These potential issues must be identified and managed so that the hydrogen sector can develop adapt or respond appropriately. Geological storage of hydrogen could present challenges in terms of perceived safety. Valuable lessons can be learned from international research and practice of CO2 and natural gas storage in geological formations (for carbon capture and storage CCS and for power respectively). Here we explore these learnings. We consider the similarities and differences between these technologies and how these may affect perceived risks. We also reflect on lessons for effective communication and community engagement. We draw on this to present potential risks to the perceived safety of - and public acceptability of – the geological storage of hydrogen. One of the key lessons learned from CCS and natural gas storage is that progress is most effective when risk communication and public acceptability is considered from the early stages of technology development.

When hydrogen flows through a small finite length constant exit area nozzle the viscous effects create a fluid throat which acts as a converging-diverging nozzle and lead to Mach number greater than one at the exit if the jet is under-expanded. This phenomenon influences the mass flow rate and the dispersion cloud size. In this study the boundary layer effect on the unsteady hydrogen sonic jet flow through a 1 mm diameter pipe from a high pressure reservoir (up to 70 MPa) is studied using computational fluid dynamics with a large eddy simulation turbulence model. This viscous flow simulation is compared with a non-viscous simulation to demonstrate that the velocity is supersonic at the exit of a small exit nozzle and that the mass flow is reduced.

Community support and acceptance is part of the licence to operate for any industry. The hydrogen industry is no different and we will need to have strong support from the broad community to establish a viable hydrogen economy in Australia.<br/>As Woodside progresses our plans for bulk hydrogen export and associated domestic opportunities stakeholder engagement throughout will be critical to success. This talk will share Woodside’s approach to community engagement and local opportunities and how we plan to draw on more than 30 years’ experience operating liquefied natural gas plants in Western Australia’s Pilbara region.<br/>At this early stage of our hydrogen work we are beginning with the end in mind: engaging the customer. We’ve worked with local Australian businesses to help raise public awareness and interest in hydrogen by producing prototype consumer products. We will share experiences from this work that underscore the value of early engagement with all stakeholders: government regulators industrial and community neighbours and end consumers to enable the hydrogen economy vision for Australia. This paper will present information on community engagement and acceptance of hydrogen in Australia.<br/>This information has come from Woodside Energy Ltd by engaging with small businesses government regulators and the community at large. As we establish community acceptance for hydrogen as an energy carrier in Australia Woodside has been working in parallel to have standards and regulations established for hydrogen in Australia. Through our work with Hydrogen Mobility Australia we are advocating the adoption of ISO standards unless there is a specific geographic or health safety and environment reason not to.

Hydrogen technologies are expected to play a key role in implementing the transition from a fossil fuel- based to a more sustainable lower-carbon energy system. To facilitate their widespread deployment the safe operation and hydrogen systems needs to be ensured together with the evaluation of the associated risk.<br/>HIAD has been designed to be a collaborative and communicative web-based information platform holding high quality information of accidents and incidents related to hydrogen technologies. The main goal of HIAD was to become not only a standard industrial accident database but also an open communication platform suitable for safety lessons learned and risk communication as well as a potential data source for risk assessment; it has been set up to improve the understanding of hydrogen unintended events to identify measures and strategies to avoid incidents/accidents and to reduce the consequence if an accident occurs.<br/>In order to achieve that goal the data collection is characterized by a significant degree of detail and information about recorded events (e.g. causes physical consequences lesson learned). Data are related not only to real incident and accidents but also to hazardous situations.<br/>The concept of a hydrogen accident database was generated in the frame of the project HySafe an EC co-funded NoE of the 6th Frame Work Programme. HIAD was built by EC-JRC and populated by many HySafe partners. After the end of the project the database has been maintained and populated by JRC with publicly available events. The original idea was to provide a tool also for quantitative risk assessment able to conduct simple analyses of the events; unfortunately that goal could not be reached because of a lack of required statistics: it was not possible to establish a link with potential event providers coming from private sector not willing to share information considered confidential. Starting from June 2016 JRC has been developing a new version of the database (i.e. HIAD 2.0); the structure of the database and the web-interface have been redefined and simplified resulting in a streamlined user interface compared to the previous version of HIAD. The new version is mainly focused to facilitate the sharing of lessons learned and other relevant information related to hydrogen technology; the database will be public and the events will be anonymized. The database will contribute to improve the safety awareness fostering the users to benefit from the experiences of others as well as to share information from their own experiences.

Recently we have seen hydrogen (re)emerge as an important component of widespread decarbonisation of energy sectors. From an Australian perspective this brings with it an opportunity to store transport and export renewable energy—either as liquefied hydrogen or in a carrier such as ammonia. The growth of the hydrogen industry to now include the power and transport sectors as well as the notion of hydrogen export has broadened the range of safety considerations required and seen them extend into the realm of the consumer for the first time.<br/>Hydrogen as well as ammonia and other carriers such as methanol are existing industrial chemicals which have established protocols for their handling and use in the chemicals sector. As their use in energy and transport increases especially in the context of widespread domestic use their handling and use by inexperienced people in less-controlled environments expands shifting the risk profiles and management systems required. There is also the potential for novel hydrogen carriers such as methylcyclohexane/toluene to reach commercial viability at industrial scale.<br/>This paper will discuss some of these emerging applications of hydrogen and its carriers and discuss some of the technological innovations under development that may accompany a new energy industry— with some consideration given to their potential risks and the required safety considerations. In addition we will also provide an overview of global activity in this area and how new standards and regulations would need to be developed for the adaption of these technologies in an Australian context.

The increased activity across the technical world for developing hydrogen has not gone unnoticed at the political level. However there remains a gap in understanding of how the general public will respond to the development of such an emergent industry. Recognising this gap we undertook ten focus groups (N=92) and a nationally representative online survey (N=2785) with the Australian public to better understand their response to hydrogen and the opportunities it presents for export and domestic use. In both focus groups and the national survey when Australians first heard the word hydrogen they were most likely to respond with a neutral response. For example in the survey 81% responded with words such as gas energy water; with only 13% giving negative associations (e.g. bomb explosion Hindenburg); and 3% positive (e.g. clean future). Males were more likely to be supportive of hydrogen than females. Those who answered more knowledge questions correctly were also more supportive. The main benefits associated with the use of hydrogen technologies centred around the environment - reduced greenhouse gas emissions and climate change mitigation potential were key benefits. With safety cost and environmental impacts - particularly concerns around pollution emissions and water use - being the most frequently cited concerns about the production and use of hydrogen. This presentation focuses on Australian attitudes to the developing hydrogen export opportunity and also for domestic use. Implications for industry and policy makers will be discussed in light of these Australians responses.

The FCH 2 JU launched the European Hydrogen Safety Panel (EHSP) initiative in 2017. The mission of the EHSP is to assist the FCH 2 JU both at programme and at project level in assuring that hydrogen safety is adequately managed and to promote and disseminate H2 safety culture within and outside of the FCH 2 JU programme. The EHSP is composed of a multidisciplinary pool of safety experts grouped in ad-hoc working groups (task forces) according to the tasks to be performed and to expertise. The scope and activities of the EHSP are structured around four main areas:

An experimental study of hydrogen/air premixed flame propagation in a closed rectangular channel with the inhibitions (N2 or CO2) was conducted to investigate the inhibiting effect of N2 and CO2 on the flame properties during its propagation. Both Schlieren system and the pressure sensor were used to capture the evolution of flame shape and pressure changes in the channel. It was found that both N2 and CO2 have considerable inhibiting effect on hydrogen/air premixed flames. Compared with N2 CO2 has more prominent inhibition which has been interpreted from thermal and kinetic standpoints. In all the flames the classic tulip shape was observed. With different inhibitor concentration the flame demonstrated three types of deformation after the classic tulip inversion. A simple theoretical analysis has also been conducted to indicate that the pressure wave generated upon the first flame-wall contact can affect the flame deformation depending on its meeting moment with the flame front. Most importantly the meeting moment is always behind the start of tulip inversion which suggests the non-dominant role of pressure wave on this featured phenomenon.

Self-acceleration of a spherically expanding hydrogen-air flame was experimentally investigated in a closed dual-chamber apparatus with the quartz windows enabled to a flame diameter with up to 240 mm. The flame radius and flame speed in lean hydrogen-air mixtures at elevated pressure were evaluated using a high speed Schlieren photography. The experimental results from hydrogen-air explosion at elevated pressure validated the prediction model for self-similar propagation. The flame radius and its speed calculated by the prediction models agree well with the experimental results of hydrogen-air explosions at elevated pressure. Furthermore the acceleration exponent α is evaluated by plotting the flame radius with time. The results show the α value increase with the dimensionless flame radius r/rcl. It is indicated that the self-acceleration and the transition regime to self-similar propagation exist in the spherically expanding hydrogen-air flame.

The H2@Scale program of the U.S. Department of Energy (DOE) Fuel Cell Technologies Office is supporting work on the hydrogen compatibility of polymers to improve the durability and reliability of materials for hydrogen infrastructure. The hydrogen compatibility program (H-Mat) seeks “to address the challenges of hydrogen degradation by elucidating the mechanisms of hydrogen-materials interactions with the goal of providing science-based strategies to design materials (micro)structures and morphology with improved resistance to hydrogen degradation.” This research has found hydrogen and pressure interactions with model rubber-material compounds demonstrating volume change and compression-set differences in the materials. The research leverages state-of-the-art capabilities of the DOE national labs. The materials were investigated using helium-ion microscopy which revealed significant morphological changes in the plasticizer incorporating compounds after exposure as evidenced by time-of-flight secondary ion mass spectrometry. Additional studies using transmission electron microscopy and nuclear magnetic resonance revealed that nanosized inclusions developed after gas decompression in rubber- and plasticizer-only materials; this is an indication of void formation at the nanometer level.