- The many aspects of a hydrogen filling station
- Hydrogen production - Splitting water molecules through electrolysis
- How energy from regenerative sources can be temporarily stored
- Explosion protection - BAM makes the use of gas mixtures safe
- Risk analysis - consequence consideration
In this field of competence BAM evaluates holistically the safe operation of hydrogen plants as well as the safety of processes for the production and conversion of hydrogen. This includes not only the safety assessment of gaseous, liquid and "bound" hydrogen and hydrogen mixtures but also the investigation of their safety properties and safe process control. By combining experimental results with validated system models, plant safety concepts are developed and reliable impact assessments are obtained for different and complex scenarios in plants and systems, so that undesired events can be avoided or their consequences limited.
Selected examples of our work are described below. Detailed information can be found in our brochure "Hydrogen: Our contribution to safety" (PDF) .
The many aspects of a hydrogen filling station
The Federal Government supports the development of a filling station network for years as an important component of a hydrogen supply infrastructure to be created. This is because a dense, reliable network of filling stations is essential for broad acceptance of the use of hydrogen vehicles. The hydrogen filling station is the central element of an overall system. In each station several technical components work together, from the electrolyser to the compressors and the high-pressure buffer storage tanks. All these components must be safe – whether in transport, during receipt and storage in storage tanks or at the interface to the vehicle. Finally, the quality of the hydrogen should not be neglected in order to rule out damage to the fuel cell.
And safety is the core competence of BAM: BAM carries out approval tests and determines the service life of hydrogen storage tanks to prevent gas leakage, it offers non-destructive test methods for monitoring components, helps to avoid undesired reactions in explosion protection with H2 sensors and checks the safe interaction of components for resilient safety concepts.
In its work, BAM relies on comprehensive digitalization. This applies in particular to the online monitoring
of plants to maximize their service life. From the point of view of digitalization, the quality infrastructure (QI) based on the interaction between standardisation, metrology, accreditation, conformity assessment and market surveillance must also be rethought.
Hydrogen production - Splitting water molecules through electrolysis
One method for large-scale hydrogen production is electrolysis. During the electrolysis of water, electrical energy is used to split water molecules (H2O) into molecular hydrogen (H2) and oxygen (O2 ) (power-togas). A large portion of the electrical energy required is converted into chemical energy. The hydrogen produced can either be stored or fed into the existing natural gas network to a certain level. With this method, energy can be temporarily stored and transported with little effort. A reconversion of the chemical energy into electrical energy is possible at any time using fuel cells.
BAM primarily works on the safe operation of electrolysers when developing new technologies for water electrolysis. The development of energy-efficient high-pressure systems requires precise knowledge of the pressure and temperature dependencies of the hydrogen-oxygen system explosion limits, as well as knowledge of permeation and leakage rates. The operational parameters of electrolysers must always be within a safe range in order to avoid dangerous contamination of the hydrogen by oxygen.
How energy from regenerative sources can be temporarily stored
One particular problem for utilising renewable energies is the large-scale storage of the energy. Many of the known storage mediums, such as batteries, store relatively little energy. The availability of other systems, such as pumped storage plants, are very limited.
A technically viable solution with virtually unlimited storage capacity is the power-to-gas process (P2G) whereby the hydrogen is subsequently fed into the natural gas grid. During the P2G process, electrical energy from wind or solar power is used to electrolyse water, thereby producing hydrogen. This allows energy from renewable sources to be stored when more is produced than is currently required. The hydrogen produced can be reconverted into electricity when needed.
Explosion protection - BAM makes the use of gas mixtures safe
Safe handling of hydrogen requires appropriate explosion protection measures. For this purpose, safety-related properties such as explosion limits, ignition temperatures and explosion pressures, are required.
BAM is therefore investigating the safety-related properties of hydrogenous gas mixtures experimentally under process conditions – even under high pressures and at high temperatures – and is further developing testing methods. BAM is also involved in the estimation of safety-related properties, establishing calculation methods and their further development. BAM supports users with safety assessments of gas mixtures and contributes its expertise in numerous ways, including to the processing of standards and technical regulations.
Risk analysis - consequence consideration
In a technical sense, ‘safety’ is a yes/no state which describes the absence of danger. Strictly speaking, the state of safety or the absence of danger means that a risk associated with the use of technology is lower than the accepted risk threshold. There is no such thing as a state of ‘100% safety’ or ‘zero risk’; that would be equivalent to a ban on technology.
In contrast to ‘safety’, ‘risk’ is quantifiable and combines the probability of an event with the consequence of the event. The ‘risk’ of a technical application is the counterpart to ‚chance‘ that arises, e.g. for the economy. In accordance with this, the definition of safety also involves weighing the opportunity of a product against the associated risk.
By combining the probability of an event and its consequences, the maximum accepted probability of this event occurring can be derived from the risk threshold and the consequence of such an event. The consideration of these probabilities of occurrence as a benchmark for safety makes it possible to break new ground for the safety assessment of hydrogen storage tanks, which also opens up new scope for design and testing requirements. Using various methods to describe the consequences, BAM harnesses these interrelationships e.g. to evaluate the ageing process of composite pressure vessels or to determine the periodicity for their periodic inspection. In addition, BAM has the necessary infrastructure to verify safety concepts of plants and/or systems in real scale and to derive and test protective measures if necessary.