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Ottobrunn, Germany

Exner A.,Papiermuhlgasse 19 9 | Lauk C.,Klagenfurt University | Zittel W.,Ludwig Bolkow Systemtechnik
Antipode | Year: 2015

In recent years, the strategic role certain metals play is seen as central to the geopolitics promulgated by state agents in the North. While a switch to renewable energy and an increase in energy efficiency might be instrumental to reducing dependence on fossil energy, it increases dependence on metals. This paper starts from an analysis of the likely availability of metals in the near future and then proceeds to investigate political concerns raised by considering the geological fundamentals of social development at the peripheries of the capitalist world-system. The inequality of metal stocks, future metal requirements and the ensuing political challenges are investigated, taking copper as an example. The final section is dedicated to the discussion of regulatory challenges in view of multiple constraints on metal extraction. This section also highlights the preconditions of a socially legitimate transition to a renewable energy system in the coming period of socio-ecological transformation. © 2014 Antipode Foundation Ltd. Source


Schlemminger C.,Norwegian University of Science and Technology | Naess E.,Norwegian University of Science and Technology | Bunger U.,Ludwig Bolkow Systemtechnik
International Journal of Hydrogen Energy | Year: 2015

A complete set of thermo-physical properties of a metal-organic framework (MOF) at close to working conditions of a cryogenic adsorption hydrogen storage (cAH2-storage) was measured and is presented in this study. Measured particle and bulk material specific heat capacities and thermal conductivities showed significant dependencies on the working conditions. The temperature-dependent conversion between the H2 isomers is enhanced by the catalytic activity of the cAH2-storage material. Hydrogen ortho- and para-isomer related properties were considered as important. The measured hydrogen adsorption showed an excess storage density at bulk-level, exceeding that of MOF-5 powder beds. A novel thermal-hydraulic cAH2-storage model was developed, including: hydrogen adsorption; real gas behavior; gas compression effects; temperature-dependent isomer concentration and conversion effects; and time-dependent boundary conditions. Additional ortho-para conversion at the inlet region of the cAH2-storage was implemented. To the knowledge of the authors, this is the first time all these effects have been considered simultaneously and compared against storage measurements including charging, discharging and dormancy conditions. The results indicate that a nearly instantaneous H2 isomer conversion takes place in the inlet region. Moreover, the total H2 stored undergoes isomer conversion. It is concluded that H2 isomer conversion in cAH2-storages containing adsorption materials, such as MOFs and activated carbon, has a significant impact on the energy balance and must be considered in thermal analyses. Copyright © 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source


Schlemminger C.,Norwegian University of Science and Technology | Naess E.,Norwegian University of Science and Technology | Bunger U.,Ludwig Bolkow Systemtechnik
International Journal of Hydrogen Energy | Year: 2016

A numerical model for a cryogenic adsorption hydrogen storage with enhanced heat distribution structure is presented and validated by experiments. The investigations cover charging, discharging and dormancy at cryogenic conditions. Metal foam was implemented as heat distribution enhancement structure. The prediction of the effective thermal conductivity, keff_foam, over the entire storage working range was carried out using an experimentally validated unit cell approach. An increase of keff_foam by +33% was observed by lowering the temperature from 295 K to 77 K, given keff_foam = 4.87 W/(m·K). The novel 2D axis-symmetric storage model developed applies two energy equations, one for the storage bed and one for the foam. Further, important thermal effects such as hydrogen isomer conversion were considered in the model. The storage model predictions were within the measurement uncertainties. A 95% storage filling was measured after 300 s charging. The enhanced heat transfer in the storage allowed highly transient charging. The volumetric and gravimetric storage capacity increased after 300 s charging by 21.5% and 9.3%, respectively. This behavior compensated for the volume and mass penalties for the implemented foam structure. However, further storage material improvements and a storage optimized heat distribution structure, including cooling fluid piping, are foreseen to meet overall storage requirements. © 2016 Hydrogen Energy Publications, LLC. Source


Bunger U.,Ludwig Bolkow Systemtechnik | Bunzeck I.,Energy Research Center of the Netherlands | Landinger H.,Ludwig Bolkow Systemtechnik | Madden B.,Element Energy | And 2 more authors.
EVS 2010 - Sustainable Mobility Revolution: 25th World Battery, Hybrid and Fuel Cell Electric Vehicle Symposium and Exhibition | Year: 2010

NextHyLights is a project called for by the European Fuel Cells and Hydrogen Joint Undertaking (FCH JU) to assist in preparing the next large-scale hydrogen vehicle demonstration projects in Europe. This paper will give an overview on the projects ambition, its focus and the expected results and reports on the status quo. It provides insight into the development of work plans for the vehicle segments "passenger cars", "buses" and "other vehicles" and the related infrastructure. As the framework conditions for the commercialisation of fuel cell vehicles are differing stronglythroughout Europe in a dedicated task the opportunities and commitment of the European regions are examined. © EVS-25 Shenzhen, China. Source


Bunger U.,Ludwig Bolkow Systemtechnik | Albes D.,DEEP. GmbH | Ball M.,Royal Dutch Shell | Becker A.,Solvay Group | And 12 more authors.
20th World Hydrogen Energy Conference, WHEC 2014 | Year: 2014

Hydrogen Underground Storage has developed as important topic in the context of Power-to-Gas schemes, with hydrogen large scale storage driven by the growing availability of cheap excess renewable electricity and the need of the transport sector to establish a hydrogen infrastructure across Europe. HyUnder comprises two parts, a general part (geology for and potential of hydrogen underground storage, below- and aboveground technology, general European energy framework and benchmarking against competing storage technologies) and a country specific part. This paper reports on the application of the general Case Study methodology to the case of Germany. Germany has served as blueprint to analyze the potential role of large scale hydrogen underground storage in Europe. The corresponding storage site specific analysis, the techno-economic simulation models and the approach to assess potential future hydrogen markets has been developed for Germany in order to better understand the role of hydrogen storage also for five other European countries. On behalf of the industry and institute partners this report presents the details from the application of the methods and the key findings, which are a backbone of the HyUnder project. Source

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