Germany

Coal and carbon-containing waste are valuable primary and secondary carbon carriers. In the current dominant linear economy such carbon resources are generally combusted to produce electricity and heat and as a way to resolve a nation’s waste issue. Not only is this a wastage of precious carbon resources which can be chemically utilized as raw materials for production of other value-added goods it is also contrary to international efforts to reduce ca Read More

As an energy-intensive industry sector the glass industry is strongly affected by the increasingly stringent climate protection targets. As established combustion-based production systems ensure high process stability and glass quality an immediate switch to low greenhouse gas emission processes is difficult. To approach these challenges this work investigates a step-by-step integration of a Power-to-Hydrogen concept into established oxyfuel gl Read More

Clarification of questions of safety represents a decisive contribution to the successful introduction of vehicles fuelled by hydrogen. At the moment the safety of hydrogen is being discussed and investigated by various bodies. The primary focus is on fuel-cell vehicles with hydrogen stored in gaseous form. This paper looks at the safety of hydrogen-fuelled vehicles with an internal combustion engine and liquefied hydrogen storage. The safety concept of BMW’s Read More

Hydrogen is not more dangerous than current fossil energy carriers but it behaves differently. Therefore hydrogen specific analyses and countermeasures will be needed to support the development of safe hydrogen technologies. A systematic step-by-step procedure for the mechanistic analysis of hydrogen behaviour and mitigation in accidents is presented. The procedure can be subdivided into four main parts:1) 3D modelling of the H2-air mixture ge Read More

This study outlines an approach to identifying the difficulties associated with the bench-marking of alkaline single cells under real electrolyzer conditions. A challenging task in the testing and comparison of different catalysts is obtaining reliable and meaningful benchmarks for these conditions. Negative effects on reproducibility were observed due to the reduction in conditioning time. On the anode side a stable passivation layer of NiO can be formed by ann Read More

In automotive applications the operational parameters for fuel cell (FC) systems can vary over a wide range. To analyze their impact on fuel cell degradation an automotive size single cell was operated under realistic working conditions. The parameter sets were extracted from the FC system modelling based on on-road customer data. The parameter variation included simultaneous variation of the FC load gas pressures cell temperature stoichiometries an Read More

Gas systems can provide considerable flexibility in integrated energy systems to accommodate hydrogen produced from Power-to-Hydrogen units using excess volatile renewable energy generation. To use the flexibility in integrated energy systems while ensuring a secure and reliable system operation gas system operators need to accurately and easily analyze the effects of varying hydrogen levels on the dynamic gas behavior and vice versa. Existin Read More

High-pressure GH2 systems are of interest for storage and distribution of hydrogen. The dynamic blow-down process of a high-pressure GH2 reservoir in case of a small leak is a complex process involving a chain of distinct flow regimes and gas states which needs to be understood for safety investigations.This paper presents models to predict the hydrogen concentration and velocity field in the vicinity of a postulated small leak. An isentropic expansion Read More

In the present work release and ignition experiments with horizontal cryogenic hydrogen jets at temperatures of 35–65 K and pressures from 0.7 to 3.5 MPa were performed in the ICESAFE facility at KIT. This facility is specially designed for experiments under steady-state sonic release conditions with constant temperature and pressure in the hydrogen reservoir. In distribution experiments the temperature velocity turbulence and concentration distributio Read More

Spontaneous ignition processes due to the high-pressure hydrogen releases into air were investigated both experimentally and theoretically. Such processes reproduce accident scenarios of sudden expansion of pressurized hydrogen into the ambient atmosphere in cases of tube or valve rupture. High-pressure hydrogen releases in the range of initial pressures from 20 to 275 bar and with nozzle diameters of 0.5 – 4 mm have been investigated. Glass tube Read More

The growing attention being paid by car manufacturers and the general public to hydrogen as a middle and long term energy carrier for automotive purpose is giving rise to lively discussions on the advantages and disadvantages of this technology – also with respect to safety. In this connection the focus is increasingly and justifiably so on the possibilities offered by a probabilistic approach to loads and component characteristics: a lower weight oblige Read More

Hydrogen technology requires efficient and safe hydrogen storage systems. For this purpose storage in solid materials such as high capacity complex hydrides is studied intensely. Independent from the actual material to be used eventually any tank design will combine nanoscale powders of highly reactive material with pressurized hydrogen gas and so far little is known about the behaviour of these mixtures in case of incidents. For a first evaluation Read More

Experiments were performed to investigate the radiative heat emission of small scale hydrogen/air explosions also impurified by minor amounts of inert particles and organic fuels. A volume of 1.5 dm3 hydrogen was injected into ambient air as free-jet and ignited. In further experiments simultaneously inert Aerosil and combustible fuels were injected into the blasting hydrogen/air gas cloud. Fuels were a spray of a solvent (Dipropyleneglycol-methyleth Read More

The BMW Hydrogen 7 is the world’s first premium sedan with a bi-fuelled internal combustion engine concept that has undergone the series development process. This car also displays the BMW typical driving pleasure. During development the features of the hydrogen energy source were emphasized. Engine tank system and vehicle electronics were especially developed as integral parts of the vehicle for use with hydrogen. The safety-oriented develop Read More

Hydrogen vehicles may emerge as a leading contender to replace today’s internal combustion engine powered vehicles. A Phenomena Identification and Ranking Table exercise conducted as part of the European Network of Excellence on Hydrogen Safety (HySafe) identified the use of hydrogen vehicles in road tunnels as a topic of important concern. An internal project called HyTunnel was duly established within HySafe to review identify and analyse the i Read More

Experiments in an obstructed semi-confined vertical combustion channel with a height of 6 m (cross-section 0.4 × 0.4 m) inside a safety vessel of the hydrogen test center HYKA at the Karlsruhe Institute of Technology (KIT) are reported. In the work homogeneous hydrogen-air-mixtures as well as mixtures with different well-defined H2-concentration gradients were ignited either at the top or at the bottom end of the channel. The combustion charact Read More

The “SUpport to SAfety aNAlysis of Hydrogen and Fuel Cell Technologies (SUSANA)” project aims to support stakeholders using Computational Fluid Dynamics (CFD) for safety engineering design and assessment of FCH systems and infrastructure through the development of a model evaluation protocol. The protocol covers all aspects of safety assessment modelling using CFD from release through dispersion to combustion (self-ignition fires deflagratio Read More

In many areas European research has been largely fragmented. To support the required integration and to focus and coordinate related research efforts the European Commission created a new instrument the Networks of Excellences (NoEs). The goal of the NoE HySafe has been to provide the basis to facilitate the safe introduction of hydrogen as an energy carrier by removing the safety related obstacles. The prioritisation of the HySafe internal project a Read More

GASFLOW is a finite-volume computer code that solves the time-dependent two-phase homogeneous equilibrium model compressible Navier–Stokes equations for multiple gas species with turbulence. The fluid-dynamics algorithm is coupled with conjugate heat and mass transfer models to represent walls floors ceilings and other internal structures to describe complex geometries such as those found in nuclear containments and facilities. Recent ap Read More

Jet fires develop on release of hydrogen from pressurized storage depending on orifice pressures and volumes. Risks arise from flame contact dispersion of hot gases and heat radiation. The latter varies strongly in time at short scales down to milliseconds caused by turbulent air entrainment and fluctuations. These jets emit bands of OH in the UV and water in the NIR and IR spectral range. These spectra enable the temperature measurement and the e Read More

This paper presents results of experimental investigations on spherical and cylindrical flame propagation in pre-mixed H2/air-mixtures in unconfined and semi-confined geometries. The experiments were performed in a facility consisting of two transparent solid walls with 1 m2 area and four weak side walls made from thin plastic film. The gap size between the solid walls was varied stepwise from thin layer geometry (6 mm) to cube geometry (1 m). A Read More

This paper summarises the results from a blind-prediction study for models developed for estimating the consequences of vented hydrogen deflagrations. The work is part of the project Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations (HySEA). The scenarios selected for the blind-prediction entailed vented explosions with homogeneous hydrogen-air mixtures in a 20-foot ISO container. The tes Read More

While most hydrogen research focuses on the technical and cost hurdles to a full-scale hydrogen economy little consideration has been given to the geopolitical drivers and consequences of hydrogen developments. The technologies and infrastructures underpinning a hydrogen economy can take markedly different forms and the choice over which pathway to take is the object of competition between different stakeholders and countries. Ov Read More

Hydrogen as a carbon-free fuel is commonly expected to play a major role in future energy supply e.g. as an admixture gas in natural gas grids. Which impacts on residential and commercial gas appliances can be expected due to the significantly different physical and chemical properties of hydrogen-enriched natural gas? This paper analyses and discusses blends of hydrogen and natural gas from the perspective of combustion science. The ad Read More

The  storage  of  hydrogen  poses  inherent  weight  volume  and  safety  obstacles.  An  innovative technology which allows for the storage of hydrogen in thin sealed glass capillaries ensures the safe infusion storage and controlled release of hydrogen gas under pressures up to 100 MPa. Glass is a non-flammable material which also guarantees high burst pressures. The pressure resistance of single and multiple capillaries has been determined fo Read More

Highly transient jets from hydrogen high pressure tanks were investigated up to 30 MPa. These hydrogen jets might self-initiate when released from small orifices of high pressure storage facilities. The related effects were observed by high speed video technics including time resolved spectroscopy. Ignition flame head jet velocity flame contours pressure wave propagation reacting species and temperatures were evaluated. The evaluation used video Read More

Computational Fluid Dynamics (CFD) tools have been increasingly employed for carrying out quantitative risk assessment (QRA) calculations in the process industry. However these tools must be validated against representative experimental data in order to have a real predictive capability. As any typical accident scenario is quite complex it is important that the CFD tool is able to predict combined release and ignition scenarios reasonably well. However this Read More

To develop safety strategies for the use of hydrogen indoors the HyIndoor project is studying the behaviour of a hydrogen release deflagration or non-premixed flame in an enclosed space such as a fuel cell or its cabinet a room or a warehouse. The paper proposes a safety approach based on safety objectives that can be used to take various scenarios of hydrogen leaks into account for the safe design of Hydrogen and Fuel Cell (HFC) early mar Read More

"The current practise of focusing the periodic retesting of composite cylinders primarily on the hydraulic pressure test has to be evaluated as critical - with regard to the damage of the specimen as well as in terms of their significance. This is justified by micro damages caused to the specimen by the test itself and by a lack of informative values. Thus BAM Federal Institute of Materials Research and Testing (Germany) uses a new approach of validation of Read More

In a scenario characterized by an increasing penetration of non-dispatchable renewable energy sources and the need of fast-ramping grid-balancing power plants the EU project GRASSHOPPER aims to setup and demonstrate a highly flexible PEMFC Power Plant hydrogen fueled and scalable to MW-size designed to provide grid support.In this work different layouts proposed for the innovative MW-scale plant are simulated to optimize design and off-design oper Read More

The possibility of flame acceleration (FA) and deflagration-to-detonation transition (DDT) when homogeneous hydrogen-carbon monoxide-air (H2-CO-air) mixtures are used rises the need for an efficient simulation approach for safety assessment. In this study a modelling approach for H2-CO-air flames incorporating deflagration and detonation within one framework is presented. It extends the previous work on H2-air mixtures. The deflagration is Read More

In the present work the effect of artificial ageing of AA2024-T3 on the tensile mechanical properties and fracture toughness degradation due to corrosion exposure will be investigated. Tensile and fracture toughness specimens were artificially aged to tempers that correspond to Under-Ageing (UA) Peak-Ageing (PA) and Over-Ageing (OA) conditions and then were subsequently exposed to exfoliation corrosion environment. The corrosion exposure time was Read More

Tensile and fatigue tests were performed on an AA2198 aluminum alloy in the T851 condition in ambient air and liquid hydrogen (LH2). All fatigue tests were performed under load control at a frequency of 20 Hz and a stress ratio of R=0.1. The Gecks-Och-Function [1] was fitted on the measured cyclic lifetimes.The tensile strength in LH2 was measured to be 46 % higher compared to the value determined at ambient conditions and the fatigue limit was increa Read More

We have designed a new method for electrochemical hydrogen charging which allows us to charge very thin coarse-grained specimens from the bottom and perform nanomechanical testing on the top. As the average grain diameter is larger than the thickness of the sample this setup allows us to efficiently evaluate the mechanical properties of multiple single crystals with similar electrochemical conditions. Another important advantage is that the top Read More

The dislocation and twinning evolution behaviors in high manganese steels Fe-22Mn-0.6C and Fe-17Mn-1.5Al-0.6C have been investigated under tensile deformation with and without diffusive hydrogen. The notched tensile tests were interrupted once primary cracks were detected using the applied direct current potential drop measurement. In parallel the strain distribution in the vicinity of the crack was characterized by digital image correlation usi Read More

Deployed at scale hydrogen could account for almost one-fifth of total final energy consumed by 2050. This would reduce annual CO2 emissions by roughly 6 gigatons compared to today’s levels and contribute roughly 20% of the abatement required to limit global warming to two degrees Celsius.On the demand side the Hydrogen Council sees the potential for hydrogen to power about 10 to 15 million cars and 500000 trucks by 2030 with many uses in othe Read More

The European Union set a 2050 decarbonization target in the Paris Agreement to reduce carbon emissions by 90–95% relative to 1990 emission levels. The path toward achieving those deep decarbonization targets can take various shapes but will surely include a portfolio of economy-wide low-carbon energy technologies/options. The growth of the intermittent renewable power sources in the grid mix has helped reduce the carbon footprint of the electr Read More

In the present study the influence of hydrogen on the fatigue behavior of the high strength martensitic stainless steel X3CrNiMo13-4 and the metastable austenitic stainless steels X2Crni19-11 with various nickel contents was examined in the low and high cycle fatigue regime. The focus of the investigations were the changes in the mechanisms of short crack propagation. Experiments in laboratory air with uncharged and precharged specimen and unc Read More

Pathways leading to a carbon neutral future for the German energy system have to deal with the expected phase-out of coal-fired power generation in addition to the shutdown of nuclear power plants and the rapid ramp-up of photovoltaics and wind power generation. An analysis of the expected impact on electricity market security of supply and system stability must consider the European context because of the strong coupling—both from an econo Read More

Green hydrogen produced from wind solar or hydro power is a suitable electricity storage medium. Hydrogen is typically employed as mid- to long-term energy storage whereas batteries cover short-term energy storage. Green hydrogen can be produced by any available electrolyser technology [alkaline electrolysis cell (AEC) polymer electrolyte membrane (PEM) anion exchange membrane (AEM) solid oxide electrolysis cell (SOEC)] if the electrolysi Read More

The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC) that are involved in the hydrogen storage technologies. With this Read More

Climate change and global warming as well as growing global demand for hydrocarbons in industrial sectors make great incentives to investigate the utilization of CO2 for hydrocarbons production. Therefore finding an in-depth understanding of the CO2 hydrogenation reactors along with simulating reactor responses to different operating conditions are of paramount importance. However the reaction mechanisms for CO2 hydrogenation and their cor Read More

To achieve the Paris Agreement’s long-term temperature goal current energy systems must be transformed. Australia represents an interesting case for energy system transformation modelling: with a power system dominated by fossil fuels and specifically with a heavy coal component there is at the same time a vast potential for expansion and use of renewables. We used the multi-sectoral Australian Energy Modelling System (AUSeMOSYS) to perfor Read More

Greenhouse gas emissions need to be drastically reduced to mitigate the environmental impacts caused by climate change and to lead to a transformation of the European energy system. A model landscape consisting of four final energy consumption sector models with high spatial (NUTS-3) and temporal (hourly) resolution and the multi-energy system model ISAaR is extended and applied to investigate the transformation pathway of the European energy s Read More

Chemical industry is the base of the value chains and has strong influence on the competitiveness of almost all branches in economics. To develop the technologies for sustainability and climate protection and at the same time to guarantee the supply of raw material is a big challenge for chemical industry. In the project CO2RRECT (CO2 - Reaction using Regenerative Energies and Catalytic Technologies) funded by the German federal ministry of Educati Read More

Achieving climate-neutrality requires considerable investment in energy storage systems (ESS) to integrate variable renewable energy sources into the grid. However investments into ESS are often unprofitable in particular for grid-scale battery storage and green hydrogen technologies prompting many actors to call for policy intervention. This study investigates investor-specific risk-return preferences for ESS investment and derives policy recommendation Read More

In this paper the implications of the use of hydrogen on product yield and conversion efficiency as well as on economic performance of a hydrogen enhanced Biomass-to-Liquid (BtL) process are analyzed. A process concept for the synthesis of fuel (gasoline and LPG) from biomass-derived synthesis gas via Methanol-to-Gasoline (MtG) route with utilization of carbon dioxide from gasification by feeding additional hydrogen is developed and modeled in Read More

Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities. This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties. Special emphasis is place Read More

Industrial hydrogen production via alkaline water electrolysis (AEL) is a mature hydrogen production method. One argument in favor of AEL when supplied with renewable energy is its environmental superiority against conventional fossil-based hydrogen production. However today electricity from the national grid is widely utilized for industrial applications of AEL. Also the ban on asbestos membranes led to a change in performance patterns making a de Read More

Climate change is one of the major problems that people face in this century with fossil fuel combustion engines being huge contributors. Currently the battery powered electric vehicle is considered the predecessor while hydrogen vehicles only have an insignificant market share. To evaluate if this is justified different hydrogen power train technologies are analyzed and compared to the battery powered electric vehicle. Even though most research focu Read More