Germany

Developers interested in high pressure storage of hydrogen for mobile use increasingly rely on composite cylinders for onboard storage or transport of dangerous goods. Thus composite materials and systems deserve special consideration. History gives interesting background information important to the understanding of the current situation as to regulations codes and standards.<br/>Based on this review origins of different regulations for the storage of hydrogen as dangerous good and as propellant for vehicles will be examined. Both categories started out using steel and sometimes aluminium as cylinder material. With composite materials becoming more common a new problem emerged: vital input for regulations on composite pressure systems was initially derived from decades of experience with steel cylinders. As a result both regulatory fields suffer somewhat from this common basis. Only recent developments regarding requirements for composite cylinders have begun to go more and more separate ways. Thus these differences lead to some shortcomings in regulation with respect to composite storage systems.<br/>In principle in spite of separate development these deficits are in both applications very much the same: there are uncertainties in the prediction of safe service life in retesting procedures of composite cylinders and in their intervals. Hence different aspects of uncertainties and relevant approaches to solutions will be explained.

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 for different glass materials. Borosilicate capillaries have been proven to have the highest pressure resistance and have therefore been selected for further series of  advanced testing.  The innovative  storage  system  is  finally  composed of  a  variable number  of modules. As such in the case of the release of hydrogen this modular arrangement allows potential hazards to be reduced to a minimum. Further advantage of a modular system is the arrangement of single modules in every shape and volume dependent on the final application. Therefore the typical locations of storage systems e.g. the rear of cars can be modified or shifted to places of higher safety and not directly involved in crashes. The various methods of refilling and releasing capillaries with compressed hydrogen the increase of burst pressures through pre-treatment as well as the theoretical analysis and  experimental results of  the resistance  of glass  capillaries will further  be discussed  in detail.

Zero Emission Vehicles (ZEVs) are necessary to help reduce the emissions in the transportation sector which is responsible for 40% of overall greenhouse gas emissions. There are two types of ZEVs Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs) Commercial Success of BEVs has been challenging thus far also due to limited range and very long charging duration. FCEVs using H2 infrastructure with SAE J2601 and J2799 standards can be consistently fuelled in a safe manner fast and resulting in a range similar to conventional vehicles. Specifically fuelling with SAE J2601 with the SAE J2799 enables FCEVs to fill with hydrogen in 3-5 minutes and to achieve a high State of Charge (SOC) resulting in 300+ mile range without exceeding the safety storage limits. Standardized H2 therefore gives an advantage to the customer over electric charging. SAE created this H2 fuelling protocol based on modelling laboratory and field tests. These SAE standards enable the first generation of commercial FCEVs and H2 stations to achieve a customer acceptable fueling similar to today's experience. This report details the advantages of hydrogen and the validation of H2 fuelling for the SAE standards.

Integral type models to describe stationary plumes and jets in cross-flows (wind) have been developed since about 1970. These models are widely used for risk analysis to describe the consequences of many different scenarios. Alternatively CFD codes are being applied but computational requirements still limit the number of scenarios that can be dealt with using CFD only. The integral models however are not suited to handle transient releases such as releases from pressurized equipment where the initially high release rate decreases rapidly with time. Further on gas ignition a second model is needed to describe the rapid combustion of the flammable part of the plume (flash fire) and a third model has to be applied for the remaining jet fire. The objective of this paper is to describe the first steps of the development of an integral-type model describing the transient development and decay of a jet of flammable gas after a release from a pressure container. The intention is to transfer the stationary models to a fully transient model capable to predict the maximum extension of short-duration high pressure jets. The model development is supported by conducting a set of transient ignited and unignited spontaneous releases at initial pressures between 25bar and 400bar. These data forms the basis for the presented model development approach.

The formation of hydrogen jets from pressurized sources and its ignition when hitting hot devices has been studied by many projects. The transient jets evolve with high turbulence depending on the configuration of the nozzle and especially the pressure in the hydrogen reservoir. In addition the length of the jets and the flames generated by ignition at a hot surface varies. Parameters to be varied were initial pressure of the source (2.5 10 20 and 40 MPa) distance between the nozzle and the hot surface (3 5 and 7 m) and temperature of the hot surface (between 400 and 1000 K). The interaction of the hydrogen jets is visualized by high-speed cinematography techniques which allow analysing the jet characteristics. By combination of various methods of image processing the visibility of the phenomena on the videos taken at 15 000 fps was improved. In addition high-speed NIR spectroscopy was used to obtain temperature profiles of the expanding deflagrations. The jets ignite already above 450 K for conditions mainly from the tubular source at 40 MPa. In addition the propagation of the flame front depends on all three varied parameters: temperature of the hot surface pressure in the reservoir and distance between nozzle and hot surface. In most cases also upstream propagation occurs. A high turbulence seems to lead to the strong deflagrations. At high temperatures of the ignition sources the interaction leads to fast deflagration and speeds up- and downstream of the jet. The deflagration velocity is close to velocity of sound and emission of pressure waves occurs.

Hydrogen safety is a relevant topic for both nuclear fission and fusion power plants. Hydrogen generated in the course of a severe accident may endanger the integrity of safety barriers and may result in radioactive releases. In the case of the ITER fusion facility accident scenarios with water ingress consider the release of hydrogen into the suppression tank (ST) of the vacuum vessel pressure suppression system (VVPSS). Under the assumption of additional air ingress the formation of flammable gas mixtures may lead to explosions and safety component failure.<br/>The installation of passive auto-catalytic recombiners (PARs) inside the ST which are presently used as safety devices inside the containments of nuclear fission reactors is one option under consideration to mitigate such a scenario. PARs convert hydrogen into water vapor by means of passive mechanisms and have been qualified for operation under the conditions of a nuclear power plant accident since the 1990s.<br/>In order to support on-going hydrogen safety considerations simulations of accident scenarios using the CFD code ANSYS-CFX are foreseen. In this context the in-house code REKO-DIREKT is coupled to CFX to simulate PAR operation. However the operational boundary conditions for hydrogen recombination (e.g. temperature pressure gas mixture) of a fusion reactor scenario differ significantly from those of a fission reactor. In order to enhance the code towards realistic PAR operation a series of experiments has been performed in the REKO-4 facility with specific focus on ITER conditions. These specifically include operation under sub-atmospheric pressure (0.2–1.0 bar) gas compositions ranging from lean to rich H2/O2 mixtures and superposed flow conditions.<br/>The paper gives an overview of the experimental program presents results achieved and gives an outlook on the modelling approach towards accident scenario simulation.

A series of experiments in a thin layer geometry performed at the HYKA test site of the KIT. The experiments on different combustion regimes for lean and stoichiometric H2/air mixtures were performed in a rectangular chamber with dimensions of 20 x 90 x h cm3 where h is the thickness of the layer (h = 1 2 4 6 8 10 mm). Three different layer geometries:

• a smooth channel without obstructions;
• the channel with a metal grid filled 25% of length and
• a metal grid filled 100% of length. 

Detail measurement of H2/air combustion behaviour including flame acceleration (FA) and DDT in closed rectangular channel have been done. Five categories of flame propagation regimes were classified. Special attention was paid to the analysis of critical condition for different regimes of flame propagation as function of the layer thickness and roughness of the channel. It was found that thinner layer suppresses the detonation onset and even with a roughness the flame is available to accelerate to speed of sound. The detonation may occur only in a channel thicker than 6 mm.

Sustainable electricity generation is gaining importance across the globe against the backdrop of ever- diminishing resources and to achieve significant reductions in CO2 emissions. One of the challenges is storing excess energy generated from wind and solar power. Siemens developed an electrolysis system based on proton exchange membrane (PEM) technology enabling large volumes of energy to be stored through the conversion of electrical energy into hydrogen. In developing this new product range Siemens worked intensively on safe operation with a special focus on safety measures (primary secondary and tertiary). Indeed hydrogen is not only a rapidly diffusing gas with a wide range of flammability but frequent lack of information leads to insecurity among the public. Siemens PEM water electrolyzer operates at a working pressure of 50 bar / 5 MPa. The current product generation is being used for demonstration purposes and fits into a 30 ft. / 9.14 m container. Further industrialized product lines up to double-digit medium voltage ranges will be available on the market short- and mid-term. The system is designed to operate self-sustaining. Therefore special features such as back-up and fail-safe mode supported by remote monitoring and access have been implemented. This paper includes Siemens' approach to develop and implement a safety concept for the PEM water electrolyzer leading into the approval and certification by a Notified Body as well as the lessons learnt from test stand and field experience in this new application field

The recent growth of the net of hydrogen fuelling stations increases the demands to transport compressed hydrogen on road by battery vehicles or tube-trailers both in composite pressure vessels. As a transport regulation the ADR is applicable in Europe and adjoined regions and is used for national transport in the EU. This regulation provides requirements based on the behaviour of each individual pressure vessel regardless of the pressure of the transported hydrogen and relevant consequences resulting from generally possible worst case scenarios such as sudden rupture. In 2012 the BAM (German Federal Institute for Materials Research and Testing) introduced consequence-dependent requirements and established them in national transport requirements concerning the “UN service life checks” etc. to consider the transported volume and pressure of gases. This results in a requirement that becomes more restrictive as the product of pressure and volume increases. In the studies presented here the safety measures for hydrogen road transport are identified and reviewed through a number of safety measures from countries including Japan the USA and China. Subsequently the failure consequences of using trailer vehicles the related risk and the chance are evaluated. A benefit-related risk criterion is suggested to add to regulations and to be defined as a safety goal in standards for hydrogen transport vehicles and for mounted pressure vessels. Finally an idea is given for generating probabilistic safety data and for highly efficient evaluation without a significant increase of effort.

The acoustic to the parametric instability has been studied for H2-air mixtures at normal conditions. Two approaches for the investigation of the problem have been considered. The simplified analytical model proposed by Bychkov was selected initially. Its range of applicability resulted to be very restricted and therefore numerical solutions of the problem were taken into account. The results obtained were used to study the existence of spontaneous transition from the acoustic to the parametric instability for different fuel concentrations. Finally the growth rate of the instabilities was numerically calculated for a set of typical mixtures for hydrogen safety.

Passive auto-catalytic recombiners (PARs) are used as safety devices in the containments of nuclear power plants (NPPs) for the removal of hydrogen that may be generated during specific reactor accident scenarios. In the presented study it was investigated whether a PAR designed for hydrogen removal inside a NPP containment would perform principally inside a typical surrounding of hydrogen or fuel cell applications. For this purpose a hydrogen release scenario inside a garage – based on experiments performed by CEA in the GARAGE facility (France) – has been simulated with and without PAR installation. For modelling the operational behaviour of the PAR the in-house code REKO-DIREKT was implemented in the CFD code ANSYS-CFX. The study was performed in three steps: First a helium release scenario was simulated and validated against experimental data. Second helium was replaced by hydrogen in the simulation. This step served as a reference case for the unmitigated scenario. Finally the numerical garage setup was enhanced with a commercial PAR model. The study shows that the PAR works efficiently by removing hydrogen and promoting mixing inside the garage. The hot exhaust plume promotes the formation of a thermal stratification that pushes the initial hydrogen rich gas downwards and in direction of the PAR inlet. The paper describes the code implementation and simulation results.

Numerous studies have shown that a full electrification of passenger cars is needed to stay within the 1.5° C temperature rise. This article deals with the question of how the required shares of alternative vehicles can be achieved by the year 2050. In literature the preferred technology are battery electric vehicles as these are more energy efficient than hydrogen vehicles. To be able to demonstrate how alternative vehicles diffuse into the German market the passenger car investment behavior of private persons was investigated. For this purpose a discrete choice experiment (DCE) with 1921 participants was carried out empirically. The results of the DCE show that the investment costs in particular are important when choosing a vehicle. This is followed by the driving range fuel costs and vehicle type. Less important are the charging infrastructure and CO₂ emissions of the vehicle. A CO₂ tax is of least importance. The utility values of the DCE were used to simulate future market shares. For this purpose the open-source software Invest was developed and different scenarios were defined and calculated. This paper shows that conservative assumptions on attribute development leave a large gap until full electrification as conventional vehicles still account for around 62% of market shares in 2050. In order to achieve full electrification extreme efforts must be made targeting the technical and economic characteristics of the vehicles but also addressing person-related characteristics such as level of information the subjective norm or the technological risk attitude. A ban on new registrations of combustion engines from 2030 could also lead to a full electrification by 2050. An average annual increase in the market share of alternative vehicles of 2.4 percentage points is needed to achieve full electrification. Other important factors are measures that address the modal shift to other modes of transport (rail public transport car-sharing).

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 tubes and high-speed CCD camera were used for experimental study of self-ignition process. The problem was theoretically considered in terms of contact discontinuity for the case when spontaneous ignition of pressurized hydrogen due to the contact with hot pressurized air occurs. The effects of boundary layer and material properties are discussed in order to explain the minimum initial pressure of 25 bar leading to the self-ignition of hydrogen with air.

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 hydrogen vehicles is described and the specific aspects of the propulsion and storage concepts discussed. The main discussion emphasis is on the utilization of boil-off parking of the vehicles in an enclosed space and their crash behaviour. Theoretical safety observations are complemented by the latest experimental and test results. Finally reference is made to the topic-areas in the field of hydrogen safety in which cooperative research work could make a valuable contribution to the future of the hydrogen-powered vehicle.

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 carbon emissions and increase resource efficiency and conservation. This article presents a concept to support the transformation from a linear ‘one-way cradle to grave manufacturing model’ toward a circular carbon economy. The development of new and sustainable value chains through the utilization of coal and waste as alternative raw materials for the chemical industry via a coupling of the energy chemical and waste management sectors offers a viable and future-oriented perspective for closing the carbon cycle. Further benefits also include a lowering of the carbon footprint and increasing resource efficiency and conservation of primary carbon resources. In addition technological innovations and developments that are necessary to support a successful sector coupling will be identified. To illustrate our concept a case analysis of domestic coal and waste as alternative feedstock to imported crude oil for chemical production in Germany will be presented. Last but not least challenges posed by path dependency along technological institutional and human dimensions in the sociotechnical system for a successful transition toward a circular carbon economy will be discussed.

The shipping industry is becoming increasingly visible on the global environmental agenda. Shipping's hare of emissions to air is regarded to be significant and public concern lead to ongoing political pressure to reduce shipping emissions. International legislation at the IMO governing the reduction of SOx and NOx emissions from shipping is being enforced and both the European Union and the USA are planning to introduce additional regional laws to reduce emissions. Therefore new approaches for more environmental friendly and energy efficient energy converter are under discussion. One possible solution will be the use of fuel cell systems for auxiliary power or main propulsion. The presentation summarizes the legal background in international shipping related to the use for gas as ship fuel and fuel cells. The focus of the presentation will be on the safety principles for the use of gas as fuel and fuel cells on board of ships and boats. The examples given show the successful integration of such  systems on board of ships. Furthermore a short outlook will be given to the ongoing and planed projects for the use of fuel cells on board of ships.

The use of hydrogen as an energy carrier is going to widen exponentially in the next years. In order to ensure the public acceptance of the new fuel not only the environmental impact has to be excellent but also the risk management of its handling and storage must be improved. As a part of modern risk assessment procedure CFD modeling of the accident scenario development must provide reliable data on the possible pressure loads resulted from explosion processes. The expected combustion regimes can be ranged from slow flames to deflagration-to-detonation transition and even to detonation. In the last case the importance of the reliability of simulation results is particularly high since detonation is usually considered as a worst case state of affairs. A set of large-scale detonation experiments performed in Kurchatov Institute at RUT facility was selected as benchmark. RUT has typical industry-relevant characteristic dimensions. The CFD codes possibilities to correctly describe detonation in mixtures with different initial and boundary conditions were surveyed. For the modeling two detonation tests HYD05 and HYD09 were chosen; both tests were carried out in uniform hydrogen/air mixtures; first one with concentration of 20.0% vol. and the second one with 25.5% vol. In the present exercise three CFD codes using a number of different models were used to simulate these experiments. A thorough inter-comparison between the CFD results including codes models and obtained pressure predictions was carried out and reported. The results of this inter comparison should provide a solid basis for the further code development and detonation models’ validation thus improving CFD predictive capabilities.

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 activities was based on a phenomena identification and ranking exercise (PIRT) and expert interviews. The identified research headlines were “Releases in (partially) confined areas” “Mitigation” and “Quantitative Risk Assessment”. Along these headlines existing or planned research work was re-orientated and slightly modified to build up three large internal research projects “InsHyde” “HyTunnel” and “HyQRA”. In InsHyde realistic indoor hydrogen leaks and associated hazards have been investigated to provide recommendations for the safe use of indoor hydrogen systems including mitigation and detection means. The appropriateness of available regulations codes and standards (RCS) has been assessed. Experimental and numerical work was conducted to benchmark simulation tools and to evaluate the related recommendations. HyTunnel contributed to the understanding of the nature of the hazards posed by hydrogen vehicles inside tunnels and its relative severity compared to other fuels. In HyQRA quantitative risk assessment strategies were applied to relevant scenarios in a hydrogen refuelling station and the performance was compared to derive also recommendations. The integration provided by the network is manifested by a series of workshops and benchmarks related to experimental and numerical work. Besides the network generated the following products: the International Conference on Hydrogen Safety the first academic education related to hydrogen safety and the Safety Handbook. Finally the network initiated the founding of the International Association for Hydrogen Safety which will open up the future networking to all interested parties on an international level. The indicated results of this five years integration activity will be described in short.

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 market applications. Knowledge gaps on current engineering models and unknown influence of specific parameters were identified and prioritized thereby re-focusing the objectives of the project test campaign and numerical simulations. This approach will enable the improvement of the specification of openings and use of hydrogen sensors for enclosed spaces. The results will be disseminated to all stakeholders including hydrogen industry and RCS bodies.

This paper presents results of an experimental investigation on detonation wave propagation in semi-confined geometries. Large scale experiments were performed in layers up to 0.6 m filled with uniform and non-uniform hydrogen–air mixtures in a rectangular channel (width 3 m; length 9 m) which is open from below. A semi confined driver section is used to accelerate hydrogen flames from weak ignition to detonation. The detonation propagation was observed in a 7 m long unobstructed part of the channel. Pressure measurements ionization probes soot-records and high speed imaging were used to observe the detonation propagation. Critical conditions for detonation propagation in different layer thicknesses are presented for uniform H2/air-mixtures as well as experiments with uniform H2/O2 mixtures in a down scaled transparent channel. Finally detail investigations on the detonation wave propagation in H2/air-mixtures with concentration gradients are shown.

The current energy system is subject to a fundamental transformation: A system that is oriented towards a constant energy supply by means of fossil fuels is now expected to integrate increasing amounts of renewable energy to achieve overall a more sustainable energy supply. The challenges arising from this paradigm shift are currently most obvious in the area of electric power supply. However it affects all areas of the energy system albeit with different results. Within the energy system various independent grids fulfill the function of transporting and spatially distributing energy or energy carriers and the demand-oriented supply ensures that energy demands are met at all times. However renewable energy sources generally supply their energy independently from any specific energy demand. Their contribution to the overall energy system is expected to increase significantly.<br/>Energy storage technologies are one option for temporal matching of energy supply and demand. Energy storage systems have the ability to take up a certain amount of energy store it in a storage medium for a suitable period of time and release it in a controlled manner after a certain time delay. Energy storage systems can also be constructed as process chains by combining unit operations each of which cover different aspects of these functions. Large-scale mechanical storage of electric power is currently almost exclusively achieved by pumped-storage hydroelectric power stations.<br/>These systems may be supplemented in the future by compressed-air energy storage and possibly air separation plants. In the area of electrochemical storage various technologies are currently in various stages of research development and demonstration of their suitability for large-scale electrical energy storage. Thermal energy storage technologies are based on the storage of sensible heat exploitation of phase transitions adsorption/desorption processes and chemical reactions. The latter offer the possibility of permanent and loss-free storage of heat. The storage of energy in chemical bonds involves compounds that can act as energy carriers or as chemical feedstocks. Thus they are in direct economic competition with established (fossil fuel) supply routes. The key technology here – now and for the foreseeable future – is the electrolysis of water to produce hydrogen and oxygen.<br/>Hydrogen can be transformed by various processes into other energy carriers which can be exploited in different sectors of the energy system and/or as raw materials for energy-intensive industrial processes. Some functions of energy storage systems can be taken over by industrial processes. Within the overall energy system chemical energy storage technologies open up opportunities to link and interweave the various energy streams and sectors. Chemical energy storage not only offers means for greater integration of renewable energy outside the electric power sector it also creates new opportunities for increased flexibility novel synergies and additional optimization.<br/>Several examples of specific energy utilization are discussed and evaluated with respect to energy storage applications. The article describes various technologies for energy storage and their potential applications in the context of Germany’s Energiewende i.e. the transition towards a more sustainable energy system. Therefore the existing legal framework defines some of the discussions and findings within the article specifically the compensation for renewable electricity providers defined by the German Renewable Energy Sources Act which is under constant reformation. While the article is written from a German perspective the authors hope this article will be of general interest for anyone working in the areas of energy systems or energy technology.

A series of experiments on hydrogen flame propagation in a thin layer geometry is presented. Premixed hydrogen-air compositions in the range from 6 to 15%(vol.) H2 are tested. Semi-open vertical combustion chamber consists of two transparent Plexiglas side walls with main dimensions of 90x20 cm with a gap from 1 to 10 mm in between. Test mixtures are ignited at the open end of the chamber so that the flame propagates towards the closed end. Ignition position changes from top to bottom in order to take into account an effect of gravity on flame propagation regimes. High-speed shadow imaging is used to visualize and record the combustion process. Thermal-diffusion and Darrieus-Landau instabilities are governing the general flame behaviour. Heat losses to side walls and viscous friction in a thin layer may fully suppress the flame propagation with local or global extinction. The sensitivity to heat losses can be characterized using a Peclet number as a ratio of layer thickness to laminar flame thickness. Approaching to critical Peclet number Pec = 42 the planar or wrinkled flame surface degradants to one-or two-heads "finger" flame propagating straight (for two-heads flame) or chaotic (for one-head "finger" flame). Such a "fingering" of the flame is found for the first time for gaseous systems and very similar to that reported for smouldering or filtering combustion of solid materials and also under micro-gravity conditions. The distance between "fingers" may depend on deficit of limiting component. The processes investigated can be very important from academic and practical points of view with respect to safety of hydrogen fuel cells.

A hydrogen purification system based on the technology of the electrochemical hydrogen compression and purification is introduced. This system is developed within the scope of the project MEMPHYS. Therefore the project its targets and the different work stages are presented. The technology of the electrochemical purification and the state of the art of hydrogen purification are described. Early measurements in the project have been carried out and the results are shown and discussed. The ability of the technology to recover hydrogen from a gas mixture can be recognized and an outlook into further optimizations shows the future potential. A big advantage is the simultaneous compression of the purified hydrogen up to 200 bar therefore facilitating the transportation and storage.

Growing demand for individual and especially complex parts with emphasis on biomedical or lightweight applications enhances the importance of laser powder bed fusion. Magnesium alloys offer both biocompatibility and low density but feature a very high melting point of oxide layers while the evaporation temperature of pure magnesium is much lower. This impedes adequate part quality and process reproducibility. To weaken this oxide layer and enhance processability a 2 %-hydrogen-argon-gas atmosphere was investigated. A machine system was modified to the use of the novel inert gas to determine the influence of gas atmosphere on hollow cuboids and solid cubes. While processing a 20.3 % decrease in structure width and 20.6 % reduction in standard deviation of the cuboids was determined. There was no significate influence on relative density of solid cubes although eight of the ten highest density specimen were fabricated with the hydrogen addition.

The energy transition – which represents the efforts undertaken and results achieved on renewable energy expansion and energy efficiency – is our basis for a clean secure and affordable energy supply which is essential for all our lives. By adopting the 2030 Climate Action Plan the Federal Government has paved the way for meeting its climate targets for 2030. Its long-term goal is to achieve carbon neutrality in line with the targets agreed under the Paris Agreement which seeks to keep global warming well below 2 degrees and if possible below 1.5 degrees. In addition Germany has committed itself together with the other European Member States to achieving greenhouse gas (GHG) neutrality by 2050. Apart from phasing out coal-fired power for which Germany has already taken the relevant decisions this means preventing emissions which are particularly hard to reduce such as process-related GHG emissions from the industrial sector.<br/>In order for the energy transition to be successful security of supply affordability and environmental compatibility need to be combined with innovative and smart climate action. This means that the fossil fuels we are currently using need to be replaced by alternative options. This applies in particular to gaseous and liquid energy sources which will continue to be an integral part of Germany’s energy supply. Against this backdrop hydrogen will play a key role in enhancing and completing the energy transition.