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Hydrogen is a key enabler of a sustainable society. Refurbishment of the existing natural gas infrastructure for up to 100% H2 is considered one of the most energy- and resource-efficient energy transportation methods. The question remains whether the transportation of 100% H2 with reasonable adaptions of the infrastructure and comparable energy amounts to natural gas is possible. The well-known critical components for refurbishment, such as increased compressor power, reduced linepack as well as pipeline transport efficiencies, and their influencing factors were considered based on thermodynamic calculations with a step-by-step overview. A H2 content of 20–30% results in comparable operation parameters to pure natural gas. In addition to transport in pipelines, decentralized H2 production will also play an important role in addressing future demands. [ABSTRACT FROM AUTHOR]

A simulation tool called HYDRA to optimize individual hydrogen infrastructure layouts is presented. The different electrolyzer technologies, namely proton exchange membrane electrolysis, anion exchange membrane electrolysis, alkaline electrolysis, and solid oxide electrolysis, as well as hydrogen storage possibilities are described in more detail and evaluated. To illustrate the application opportunities of HYDRA, three project examples are discussed. The examples include central and decentral applications while taking the usage of hydrogen into account. [ABSTRACT FROM AUTHOR]

Byline: Manfred Klell, Helmut Eichlseder, Markus Sartory Taking advantage of the multi-fuel ability of internal combustion engines, a vehicle concept is presented that combines the conventional functionality of gasoline operation with the potential for CO.SUB.2-free operation with hydrogen, biogas or any mixtures of these two gases. By means of a prototype vehicle that was adapted and approved for road traffic, necessary safety measures for gas-powered vehicles are detailed, and a survey of international standards and regulations is given. An electronic gas safety system was developed allowing on-board monitoring of the condition of the gas system.

In this paper a semi-empiric zero-dimensional steady state simulation model of an asymmetric high pressure proton exchange membrane water electrolyser is being presented. Based on experimental investigations on a 9.6 kW asymmetric high pressure water electrolysis module, empirical parameters were determined. Measurements were taken by varying the production pressure between 70 bar and 155 bar, the process temperature between 45 °C and 75 °C and the current density from 0.81 A cm −2 to 1.85 A cm −2 . Stack efficiency and hydrogen diffusion from the cathode to the anode side were determined and expressed by the faradaic efficiency. Stack efficiencies of up to 74.8% were achieved at 0.81 A cm −2 , 75 °C and 155 bar. As expected the stack efficiency decreases with increasing hydrogen production pressure. A temperature decrease of 30 °C has greater impact on the efficiency than an increase of pressure from 70 to 155 bar. The faradaic efficiency at 1.85 A cm −2 , 155 bar and 45 °C is higher than 99% and even at a high operating temperature of 75 °C higher than 97%. The presented model can be used for prediction of the stack voltage, gas production flow rates, water consumption and stack efficiency as function of input current, process temperature and production pressure. Results show a very satisfactory consistency of measurement and simulation. [ABSTRACT FROM AUTHOR]

Hydrogen plays a vital role in decarbonizing the mobility sector. With the number of hydrogen vehicles expected to drastically increase, a network of refuelling stations needs to be built to keep up with the hydrogen demand. However, further research and development on hydrogen refuelling infrastructure, storage and standardization is required to overcome technical and economic barriers. Simulation tools can reduce time and costs during the design phase, but existing models do not fully support calculations of complete and arbitrary system layouts. Therefore, a flexible simulation toolbox for rapid investigations of hydrogen refuelling and extraction processes as well as development of refuelling infrastructure, vehicle tank systems and refuelling protocols for non-standardized applications was developed. Our model library, H2VPATT, comprises of typical components found in refuelling infrastructure. The key component is the hydrogen tank model. The simulation model was successfully validated with measurement data from refuelling tests of a 320 l type III tank. [Display omitted] • Development of a flexible and customizable tool for hydrogen filling/storage systems. • Model for simulation of custom refuelling protocols. • Model validation with experiments. [ABSTRACT FROM AUTHOR]

Abstract: A zero-dimensional thermodynamic real gas simulation model for a tank filling process with hydrogen is presented in this paper. Ideal gas and real gas simulations are compared and the entropy balance of the filling process is formulated. Calculated results are validated for a type I tank (steel vessel) with measurements. The simulation is used to accurately predict the maximum gas temperature during the refueling of pressurized gaseous hydrogen storages, which must not exceed 85 °C according to international standards. The influences of ambient temperature, initial pressure and pressure ramp rate on the resulting hydrogen gas temperature in the tank are investigated. In experiments, the effect of pressure pulses applied in practice on the resulting gas temperature is investigated as is the influence of the Joule–Thomson effect of hydrogen and methane. Finally simulations and experimental results are used to develop a refueling protocol for hydrogen powered industrial trucks, in operation at Europe's first indoor hydrogen filling station in Linz, Austria. [Copyright &y& Elsevier]