Sustainable and Resilient Energy for Europe?!

Hydrogen is supposed to play a key role as an energy vector in any future, carbon-neutral energy system. Nowadays, the largest share of hydrogen is still made via CO₂-intensive steam reforming processes using methane, coal, oil or other carbon-containing feedstock. The transition to a clean energy system requires hydrogen production without CO₂ emission, where one viable route is via electrolysis of water. If the used electricity is generated renewably and without CO₂ emissions, the hydrogen made by electrolysis can be termed as ‘green H2’. As scalable and transportable storage molecule, hydrogen can help to mitigate intermittency issues related to the annual and diurnal fluctuations of renewable energies like wind and solar energy. Furthermore, hydrogen brings in flexibility in downstream processes as a platform molecule to produce for instance higher-energy liquid fuels. In the tutorial lecture, hydrogen production using renewable energy will be discussed in the context of the energy transition and gauged against conventional H₂ production technologies.

Prof. Dr. Jan Philipp Hofmann heads the Surface Science Laboratory in the Department of Materials and Geosciences at TU Darmstadt since April 2020. The research of the Surface Science Laboratory aims to increase and apply fundamental understanding of chemical and physical processes, energetics and dynamics of surfaces and interfaces in materials and devices for renewable energy conversion and storage.Hofmann is a chemist, after his PhD in physical chemistry at the Justus Liebig University Giessen in 2009 and postdoctoral stays in Giessen and at Utrecht University, NL, he was appointed as tenure track Assistant Professor of Inorganic Materials Chemistry at Eindhoven University of Technology (TU/e) in 2013. After receiving tenure at TU/e in 2016, he moved to TU Darmstadt in 2020.

The production of green hydrogen via solar-powered water splitting will play an important role in the future energy infrastructure. Photo-electrochemical (PEC) devices offer a direct pathway for solar hydrogen production by integrating light absorption and electrocatalysis in a single device. In this lecture we will review the fundamental principles of PEC water splitting, discuss materials requirements and promising photoelectrode candidates, and show several examples of state-of-the-art PEC tandem devices. Since most of the efficiency losses occur at the solid/solid and solid/liquid interfaces in these multilayer photoelectrodes, understanding of interfacial energetics and charge transfer processes under operationally relevant conditions is essential. Recent developments in in situ and operando synchrotron-based photoemission spectroscopy have made it possible to study these interfaces in unprecedented detail, and an example will be shown for the BiVO4 / electrolyte interface. Finally, with solar-to-H2 efficiencies approaching – or even exceeding – the 10% threshold, scale-up efforts become increasingly important. We will discuss the engineering challenges associated with scale-up and the main causes of efficiency losses in large area devices. We will also briefly discuss a net energy balance assessment and show how coupling PEC hydrogen production to a heterogeneous catalytic hydrogenation reaction offers some compelling advantages.

Prof. Dr. Roel van de Krol is head of the Institute for Solar Fuels at the Helmholtz-Zentrum Berlin (HZB) and full professor at the Chemistry Department of TU Berlin. He earned his PhD from TU Delft in 2000, was a postdoctoral fellow at MIT, and was assistant professor at TU Delft until joining HZB in 2012. His group focuses on the development of materials and devices for the photoelectrochemical conversion of sunlight into chemical fuels. This includes the development of deposition processes for thin film photoelectrodes and catalysts and scale-up of solar fuel devices to the ~100 cm² scale. The group specializes in metal oxide absorbers and aim to understand the fundamental processes of charge generation, separation, and transfer in the bulk and at the surfaces and interfaces of these materials. The experimental toolbox includes a range of thin film deposition techniques, (photo-)electrochemistry, time-resolved spectroscopy on fs – s time scales, surface chemistry, synchrotron-based methods, and modeling and simulation of (photo)electrochemical devices.

Low-temperature fuel cells are a technology that has been known for a long time, but is still rarely used in practice despite the mild operating temperatures of approx. 80°C. The lecture discusses the fundamentals and research areas of electrochemical power generation using the example of the polymer electrolyte fuel cell (PEFC), the possible future areas of application as well as cost and efficiency targets for the successful implementation of this technology. In particular, the published cost targets for the market entry of this new technology are analysed and possible influencing factors are discussed. The advantages of the fuel cell, such as the vibration-free and low-emission operation, the potentially long service life and the availability of green hydrogen as an energy carrier of the future, as well as the general desire for green, emission-free and resource-saving electricity in mobility and stationary applications, will accelerate the broad commercialisation in the near future and help this technology to achieve an economic breakthrough.

After a two-year research stay in Japan and his doctorate, Viktor Hacker established the Fuel Cells and Hydrogen Research Group at TU Graz around the turn of the millennium in cooperation with industrial partners as part of a Christian Doppler Laboratory. Prof. Hacker has contributed to more than 100 publications, regularly organises summer schools with Yokohama National University, was appointed extraordinary Professor at the South African Institute of Advanced Materials Chemistry, carried out numerous international research projects and in 2017 received the State Prize of the Federal Ministry of Transport, Innovation and Technology (bmvit) for the H2 Mobility project. He was appointed professor for hydrogen-based technologies in 2021, is the Austrian representative in the IEA for PEFC and has headed the Institute of Chemical Engineering and Environmental Technology at TU Graz since 2022.

Metal powders have been proposed as a promising circular fuel for long-term storage and long-distance transport of clean energy owing to their carbon-free nature, high energy density, and recyclability after combustion. The opportunities and challenges of using iron powder as circular fuel will be discussed. More specifically the research at TU Eindhoven on iron powder combustion will be highlighted, varying from fundamental studies on single particle conversion, flame propagation in iron aerosols, and lab-scale flames, to application in practical systems in close collaboration with Metalot’s Future Energy Lab, which focuses on accelerating the energy transition by testing and perfecting promising systems and technologies for the market.

Jeroen van Oijen is full professor in the Power & Flow group at the department of Mechanical Engineering of the Eindhoven University of Technology (TU/e). He is a specialist in theoretical and numerical modelling of combustion with application to engines, gas-turbines, boilers and furnaces. He heads a group that aims to develop new models for the design of devices employing new combustion concepts and future sustainable fuels. Jeroen van Oijen received his MSc in Applied Physics from TU/e in 1996 and his PhD in Mechanical Engineering from the same institute in 2002. He was visiting professor at Stanford University, CA, in 2010, and at the University of California Berkeley, CA, in 2014. He is Fellow of The Combustion Institute for significant contributions to the development of numerical models and tools for laminar and turbulent flames, based on tabulated chemistry.

to be announced

Fuel cells are devices that efficiently convert the chemical energy of a fuel into electrical energy via electrochemical reactions. Among the wide variety of fuel cell types, low temperature fuel cells (PEMFC and AEMFC) are promising for transportation, and portable applications since they operate close to ambient conditions. The main drawbacks of low temperature fuel cells are represented by the use of costly Pt-based catalysts at both the anode and the cathode, and in particular the sluggish oxygen reduction reaction (ORR) at the cathode side. Among several types of catalysts for ORR, the most promising alternative to Pt until now are carbonaceous materials doped with N and transition metals (mostly Fe, Co). This lecture will address the main synthesis techniques adopted for the production of these Me-N-C catalysts, included the use of biomass in a circular economy perspective.

Stefania Specchia, Chemical Engineer, Full Professor of Chemical Plants Design. Associated Research at the CNR-ITAE “Nicola Giordano” (Italy). Lecturer of two courses: Design of Multiphase Apparatuses and Electrochemical Power Sources. Editor of Chemical Engineering Journal (Elsevier) and Electrochemical Energy Reviews (Springer). She authored/co-authored 138 peer-reviewed publications on international journals, 8 chapters of international books, 1 international patent (on Scopus database: Hirsch index equal to 43, 4790 citations). She attended 77 international congresses (26 as invited keynote). Research activities: she is the leader of the Gre.En2 Group (Green Energy & Engineering Group). Main research topics: 1. Catalytic combustion of light hydrocarbons in lean conditions; 2. Hydrogen production in fuel processors; 3. Low-temperature fuel cells (PEMFC and DMFC); 4. Energetic valorization of wastes. She is/was the principal investigator of EU and national research projects, and various international cooperation (overall funding: 1.37 M€).

Anion exchange membrane fuel cells (AEMFC) appear viable alternatives to the acidic counterparts as several earth-abundant metals have higher thermodynamic stability in alkaline media enabling long lifespan with reduced scarce noble metal loading. However, the hydrogen oxidation reaction (HOR) is more sluggish in alkaline media compared to the acid ones. Consequently, AEMFCs have relatively high energy losses retarded two sluggish electrochemical half reactions, i.e., HOR at the anode and oxygen reduction reaction (ORR) at the cathode. To achieve reasonable activists, relatively high loadings of scarce and expensive platinum group metals (PGMs) are used in the state of the art AEMFCs to promote the HOR while for ORR earth abundant element based alternative exist. In addition to nanomaterial stability related phenomena, the electrocatalysts durability issues are reflect the high reactivity of the hydroxide ions present as charge carried in AEM based devices. In this lecture, we discuss recent trend in electrocatalysts development for AEMFCs and related issues.

Prof. Tanja Kallio, D.Sc.(Eng.), has been heading the Group of Electrochemical Energy Conversion at the Aalto University Department of Chemistry and Materials Science (Finland) since the year 2015. Her research focuses on investigation of materials for electrochemical energy conversion and storage devices including acidic and alkaline polymer electrolyte fuel cells, electrolyzers and lithium batteries. The core theme is improving the device sustainability by increasing material and operation efficiencies. She has published some 150 journal articles reflecting her interest in material development for electrochemical energy applications and understanding of activity and durability complexities. She is known, in particularly, on her work with functionalized carbon nanomaterial based electroactive materials. Her recent publications include development of platinum group metal lean electrocatalysts for hydrogen oxidations and reduction reactions with excellent activity and stability.

The EU and its member states have placed their bet on hydrogen to play a key role in decarbonising sectors. State and private actors in Europe have engaged in various efforts to develop the infrastructure, technology, and political setting for hydrogen as alternative energy source. The following questions are reflecting the difficulties for a hydrogen market ramp-up: When will there be enough hydrogen available? How much will we have to import and from whom? What colour will the hydrogen be? How will the market ramp-up be politically regulated? What role does the EU play? What the national and regional level? What is the attitude of citizens towards hydrogen? Will society accept hydrogen technology? The paper will address these issues and give an overview of the strategies and decision-making on the issue of hydrogen market introduction at the different levels from the regional to the European level.

Michèle Knodt is Professor of Political Science, Jean Monnet Chair (ad personam) and Director of the Jean Monnet Centre of Excellence ‘EU in Global Dialogue’ (CEDI), Director of the Jean Monnet Centre of Excellence ‘EU@School’, Chair of the COST Network ENTER (EU Foreign Policy Facing New Realities), Co-leader of the Loewe-Excellence Centre ‘emergenCITY’, and Co-leader of the DFG Research Training Group ‘Critical Infrastructures’, PI in the Kopernikus Project ‘Ariadne – Evidence-Based Assessment for the Design of the German Energy System Transformation’ and leader of smaller cooperative and interdisciplinary projects. She has published widely on the EU, is especially interested in energy and climate governance and has received research grants from the German Federal Ministry of Education and Research (BMBF), German Federal Ministry of Economic Affairs and Energy (BMWi), the German Research Council (DFG), the Volkswagen Foundation and the European Commission.

The transformation of energy systems to achieve climate neutrality is one of the most pressing challenges of our time. To increasingly replace fossil fuels with energy from renewable sources such as wind and solar, chemical energy carriers are the key to storing, transporting and using renewable energy independent of the time and location of its production. A particularly prominent example of such a chemical energy carrier is hydrogen. However, hydrogen is challenging to store or transport at utility scale. As another complementary option to hydrogen, metals as recyclable energy carrier have come more into the focus of science and industry. Iron in particular is a promising option for a carbon-free cycle. Iron is non-toxic, safe to transport, easy to store, abundant, and in principle can be recycled an unlimited number of times.

In this presentation, iron is first introduced as a recyclable chemical energy carrier for a carbon-free circular economy. During the reduction of iron oxides, energy from renewable sources such as wind and solar is stored. Opportunities and challenges are discussed including the availability of iron, the complementarity to hydrogen, the required reduction capacities for iron oxides and the climate neutral retrofit of existing infrastructure such as coal power plants. Another focus is the evaluation of long-distance transport and the comparison with other energy carriers such as hydrogen.

Christian Hasse is head of the Institute for the Simulation of Reactive Thermo-Fluid Systems at Technical University of Darmstadt. From 2010-2017 he was full professor at the Technische Universität Bergakademie Freiberg. From 2004-2010 he worked at BMW in engine development and exhaust aftertreatment. He received his doctorate at RWTH Aachen University in 2004 (supervisor: Norbert Peters). He has successfully supervised more than 25 PhD students and currently 30 PhD students and post-docs are working in his group in Darmstadt. His main research interests are combustion theory, modeling and simulation with application to technical systems such as IC engines, aero-engines, furnaces and reactors in process engineering. He has published over 200 peer-reviewed journal papers. He is fellow of the International Combustion Institute for his contributions to turbulent combustion, solid fuel combustion, multi-phase flows and soot formation.

Andreas Dreizler graduated from the University at Heidelberg in Physics (1992) and earned his PhD in Physical Chemistry at the same University. He completed his habilitation in 2002 in Combustion at the Technische Universität Darmstadt. Prof. Dreizler was appointed as chair of the Institute Reactive Flows and Diagnostics at the Department of Mechanical Engineering, TU Darmstadt, in 2008. His research interests include Applied Spectroscopy, Optical Diagnostics, Turbulent Reactive Flows, Fundamental Problems in Combustion. In 2014 he was awarded with the Wilhelm Gottfried Leibniz Price and in 2018 he was elected as Fellow of the International Combustion Institute. In 2021 he was elected as member of acatech, the National Academy of Science and Engineering, and in 2022 as member of the Academy of Sciences and Literature, Mainz.

Ninety percent of raw materials used in the EU chemical industry are from fossil resources. A future industrial system that is independent of fossil resources will require the use of alternative raw materials, such as carbon dioxide, biomass, or waste for the production of chemicals and materials. This will provide major opportunities and challenges for technology

developers, industries and policymakers as not only a large number of breakthrough technologies and major shifts in core processes will be needed, but also processes that use alternative raw materials are not inherently more efficient or environmentally sound than their petrochemical counterparts. Furthermore, industrial clusters are complex systems with many and increasingly intertwined processes between and within firms. Interventions in any single process can affect other processes, both at the local scale of an industrial cluster and in the supply chains involved (which are geographically dispersed). In this talk, I will introduce key challenges for industrial defossilization level as well as work we are currently conducting to model the potential resource, energy, and costs impacts of defossilizing multiple and interconnected value chains in petrochemical clusters.

Dr. Andrea Ramírez Ramírez is professor of Low Carbon Systems and Technologies in the Faculty of Technology, Policy and Management at Delft University of Technology in the Netherlands. Her research focuses on the evaluation of novel low-carbon technologies and the design of methodologies and tools to assess their potential contribution to sustainable industrial systems. Prof. Ramirez has (co-) authored over 115 publications, she is director of the University Graduate School and Editor-in-Chief of the International Journal of Greenhouse Gas Control.