@article{lausch_new_2024,

title = {New insights into the dissolution mechanisms of iron oxides and combusted iron particles in oxalic acid},

author = { M. Lausch and A. Zimina and J. Bao and R. Pashminehazar and B. J. M. Etzold and U. I. Kramm and J.-D. Grunwaldt and J. Hussong},

url = {https://pubs.aip.org/jcp/article/161/19/194308/3321052/New-insights-into-the-dissolution-mechanisms-of},

doi = {10.1063/5.0229410},

issn = {0021-9606, 1089-7690},

year  = {2024},

date = {2024-11-21},

urldate = {2024-12-06},

volume = {161},

number = {19},

pages = {194308},

abstract = {The influence of oxidation state and crystalline structure on the dissolution mechanisms of both pure iron oxides and combusted iron particles in aqueous oxalic acid (0.5 mol/l) at 60 °C was systematically investigated. Dissolution experiments were carried out in a temperature-controlled, continuous-flow capillary reactor, allowing for the removal of reaction products and thereby suppressing the autocatalytic reaction mechanism. The non-reductive dissolution of α-Fe2O3 was observed through in situ x-ray absorption measurements. In contrast, the dissolution of spinel-type oxides such as γ-Fe2O3 and Fe3O4 proceeded reductively, indicated by gradual changes in characteristic spectral features. Given that γ-Fe2O3 and Fe3O4 share a similar crystal structure but differ in the nominal oxidation state, this implies that the phase composition is decisive for the reductive dissolution. For mixed-phase particles consisting of spinel and rhombohedral phases (maghemite and hematite), the preferential dissolution of the spinel phase was observed. Despite the similar bulk composition of spinel and rhombohedral phases in the combusted iron particles (as confirmed by Mössbauer spectroscopy and x-ray diffraction analysis), dissolution predominantly follows a non-reductive pathway, with no preferential dissolution of the γ-phase. This unique dissolution behavior of combusted iron particles arises from their layered microstructure.},

note = {P125},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{radojicic_clash_2024,

title = {The Clash of the Policies: The Joint Effect of EU Cohesion Policy and Common Agricultural Policy on the Public Support for European Integration},

author = { Nikola Radojičić},

url = {https://onlinelibrary.wiley.com/doi/10.1111/jcms.13680},

doi = {10.1111/jcms.13680},

issn = {0021-9886, 1468-5965},

year  = {2024},

date = {2024-10-20},

urldate = {2025-05-26},

pages = {jcms.13680},

abstract = {Abstract 

 A vital element of the European Union (EU) political system is the idea of further European integration. Whilst most existing works investigate the effects of the Cohesion Policy (CP), only a handful of studies consider the effects of the Common Agricultural Policy (CAP) on citizens' support for European integration. In this contribution, I argue that these two largest EU redistribution policies neutralise each other in their effects on the citizens' support for European integration: the CP improves public support due to its positively perceived redistributive nature and positive externalities, whilst the CAP decreases public support due to due to a limited target audience, somewhat elitarian distribution of resources and bureaucratic complexities. Using regional‐level CP and CAP data for 2017 and Eurobarometer surveys for 2018 and 2019, the empirical findings of multilevel regressions show that the CAP counteracts the positive effects of the CP on citizens' support for further European integration. The findings are robust to including a wide range of control variables, sample size change and alternative specifications of key independent variables. These findings also hint that policy evaluations should not disregard the differences between various policy instruments.},

note = {P141},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{braun_following_2024,

title = {Following the Structural Changes of Iron Oxides during Reduction under Transient Conditions},

author = { Lukas Braun and Jonas Spielmann and Dmitry E. Doronkin and Carola Kuhn and Aleksandr Maliugin and Dmitry I. Sharapa and Isabel Huck and Jianing Bao and Steffen Tischer and Felix Studt and Olaf Deutschmann and Ulrike I. Kramm and Jan-Dierk Grunwaldt},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cssc.202401045},

doi = {10.1002/cssc.202401045},

issn = {1864-5631, 1864-564X},

year  = {2024},

date = {2024-07-08},

urldate = {2024-07-11},

pages = {e202401045},

abstract = {Iron is considered as attractive energy carrier in a carbon‐free circular energy economy. The reduction of iron oxide is crucial for its applica­tion as a metal fuel as it determines the efficiency of the cycle. Temperature programmed reduction of α‐Fe2O3 was monitored by complementary X‐ray absorption spectroscopy (XAS) and diffraction (XRD) to obtain the phase composition with high time resolution. Synchrotron Mössbauer spectroscopy (SMS) was additionally employed due to its high sensitivity to the different iron species. Theoretical calculations of surface and bulk adsorption processes were performed to establish the potential reaction pathways and the corresponding energy barriers. A kinetic particle model was then developed to bridge the experimental data and theoretical calculations, which reproduced the reduction onset and behavior. The reduction process was found to be strongly dependent on the heating rate in terms of the reduction window and the observed intermediate species. We propose that a core‐shell mechanism determines the reaction by forming an iron layer which subsequently hinders diffusion of water out of the porous particles leading to some unreduced FeO at high temperature. This study demonstrates the need for complementary methods for describing complex heterogeneous systems and overcoming the chemical sensitivity limitations of any single method.},

note = {P122},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kuhn_iron_2024,

title = {Iron as recyclable metal fuel: Unraveling oxidation behavior and cyclization effects through thermogravimetric analysis, wide‐angle X‐ray scattering and Mössbauer spectroscopy},

author = { Carola Kuhn and Anna Knapp and Max P. Deutschmann and Jonas Spielmann and Steffen Tischer and Ulrike I. Kramm and Hermann Nirschl and Olaf Deutschmann},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cssc.202400351},

doi = {10.1002/cssc.202400351},

issn = {1864-5631, 1864-564X},

year  = {2024},

date = {2024-05-03},

urldate = {2024-06-06},

pages = {e202400351},

abstract = {The carbon‐free chemical storage and release of renewable energy is an important task to drastically reduce CO2 emissions. The high specific energy density of iron and its recyclability makes it a promising storage material. Energy release by oxidation with air can be realized by the combustion of micron‐sized iron powders in retro‐fitted coal fired power plants and in fixed‐bed reactors under milder conditions. An experimental parameter study of iron powder oxidation with air was conducted based on thermogravimetric analysis in combination with wide‐angle X‐ray scattering and Mössbauer spectroscopy. In agreement with literature the oxidation was found to consist of a very fast initial oxidation of the outer particle layer followed by much slower oxidation due to diffusion of iron ions through the Fe2O3/Fe3O4 layer being the ratelimiting step. Scanning electron microscopy analysis of the iron particle before and after oxidation reveal a strong particle morphology transformation. This impact on the reaction was studied by cyclization experiments. Up to 10 oxidation‐reduction cycles show that both, oxidation and reduction rates, increase strongly with cycling due to increased porosity.},

note = {P120},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{schulze_evaluating_2024,

title = {Evaluating Partners for Renewable Energy Trading: A Multidimensional Framework and Tool},

author = { Kai Schulze and Mile Mišić and Nikola Radojičić and Berkin Serin},

url = {https://www.mdpi.com/2071-1050/16/9/3632},

doi = {10.3390/su16093632},

issn = {2071-1050},

year  = {2024},

date = {2024-04-26},

urldate = {2024-05-02},

volume = {16},

number = {9},

pages = {3632},

abstract = {The worsening climate crisis has increased the urgency of transitioning energy systems from fossil fuels to renewable sources. However, many industrialized countries are struggling to meet their growing demand for renewable energy (RE) through domestic production alone and, therefore, seek to import additional RE using carriers such as hydrogen, ammonia, or metals. The pressing question for RE importers is therefore how to select trading partners, i.e., RE exporting countries. Recent research has identified a plethora of different selection criteria, reflecting the complexity of energy systems and international cooperation. However, there is little guidance on how to reduce this complexity to more manageable levels as well as a lack of tools for effective partner evaluation. This article aims to fill these gaps. It proposes a new multidimensional framework for evaluating and comparing potential RE trading partners based on four dimensions: economy and technology, environment and development, regulation and governance, and innovation and cooperation. Focusing on Germany as an RE importer, an exploratory factor analysis is used to identify a consolidated set of composite selection criteria across these dimensions. The results suggest that Germany’s neighboring developed countries and current net energy exporters, such as Canada and Australia, are among the most attractive RE trading partners for Germany. A dashboard tool has been developed to provide the framework and composite criteria, including adjustable weights to reflect the varying preferences of decision-makers and stakeholders. The framework and the dashboard can provide helpful guidance and transparency for partner selection processes, facilitating the creation of RE trade networks that are essential for a successful energy transition.},

note = {P46},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{luu_carrier-phase_2024,

title = {Carrier-Phase DNS of Ignition and Combustion of Iron Particles in a Turbulent Mixing Layer},

author = { Tien Duc Luu and Ali Shamooni and Andreas Kronenburg and Daniel Braig and Johannes Mich and Bich-Diep Nguyen and Arne Scholtissek and Christian Hasse and Gabriel Thäter and Maurizio Carbone and Bettina Frohnapfel and Oliver Thomas Stein},

url = {https://link.springer.com/10.1007/s10494-023-00526-y},

doi = {10.1007/s10494-023-00526-y},

issn = {1386-6184, 1573-1987},

year  = {2024},

date = {2024-02-08},

urldate = {2024-02-13},

abstract = {Abstract 

 Three-dimensional carrier-phase direct numerical simulations (CP-DNS) of reacting iron particle dust clouds in a turbulent mixing layer are conducted. The simulation approach considers the Eulerian transport equations for the reacting gas phase and resolves all scales of turbulence, whereas the particle boundary layers are modelled employing the Lagrangian point-particle framework for the dispersed phase. The CP-DNS employs an existing sub-model for iron particle combustion that considers the oxidation of iron to FeO and that accounts for both diffusion- and kinetically-limited combustion. At first, the particle sub-model is validated against experimental results for single iron particle combustion considering various particle diameters and ambient oxygen concentrations. Subsequently, the CP-DNS approach is employed to predict iron particle cloud ignition and combustion in a turbulent mixing layer. The upper stream of the mixing layer is initialised with cold particles in air, while the lower stream consists of hot air flowing in the opposite direction. Simulation results show that turbulent mixing induces heating, ignition and combustion of the iron particles. Significant increases in gas temperature and oxygen consumption occur mainly in regions where clusters of iron particles are formed. Over the course of the oxidation, the particles are subjected to different rate-limiting processes. While initially particle oxidation is kinetically-limited it becomes diffusion-limited for higher particle temperatures and peak particle temperatures are observed near the fully-oxidised particle state. Comparing the present non-volatile iron dust flames to general trends in volatile-containing solid fuel flames, non-vanishing particles at late simulation times and a stronger limiting effect of the local oxygen concentration on particle conversion is found for the present iron dust flames in shear-driven turbulence.},

note = {P103},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{loewe_impact_2024,

title = {The Impact of the Russian War against Ukraine on the German Hydrogen Discourse},

author = { Martha Loewe and Christine Quittkat and Michèle Knodt and Ingrid Ott},

url = {https://www.mdpi.com/2071-1050/16/2/773},

doi = {10.3390/su16020773},

issn = {2071-1050},

year  = {2024},

date = {2024-01-16},

urldate = {2024-01-18},

volume = {16},

number = {2},

pages = {773},

abstract = {This contribution delves into the transformative effects of the Russian–Ukrainian war on the discourse surrounding German hydrogen. Employing structural topical modeling (STM) on a vast dataset of 2192 newspaper articles spanning from 2019 to 2022, it aims to uncover thematic shifts attributed to the Russian invasion of Ukraine. The onset of the war in February 2022 triggered a significant pivot in the discourse, shifting it from sustainability and climate-change mitigation to the securing of energy supplies through new partnerships, particularly in response to Russia’s unreliability. Germany started exploring alternative energy trading partners like Canada and Australia, emphasizing green hydrogen development. The study illustrates how external shocks can expedite the uptake of new technologies. The adoption of the “H2 readiness” concept for LNG terminals contributes to the successful implementation of green hydrogen. In summary, the Russian–Ukrainian war profoundly impacted the German hydrogen discourse, shifting the focus from sustainability to energy supply security, underscoring the interconnectedness of energy security and sustainability in Germany’s hydrogen policy.},

note = {P102},

keywords = {{FF}4},

pubstate = {published},

tppubtype = {article}

}

@article{li_particle-resolved_2023,

title = {Particle-resolved optical diagnostics of solid fuel combustion for clean power generation: a review},

author = { Tao Li and Christopher Geschwindner and Andreas Dreizler and Benjamin Böhm},

url = {https://iopscience.iop.org/article/10.1088/1361-6501/acef49},

doi = {10.1088/1361-6501/acef49},

issn = {0957-0233, 1361-6501},

year  = {2023},

date = {2023-12-01},

urldate = {2023-09-14},

volume = {34},

number = {12},

pages = {122001},

abstract = {Abstract 

 Chemical energy carriers are crucial for addressing challenges that arise from time lag, large distances, and temporal fluctuations in renewable energy production, which lead to unbalanced energy production and demand. The thermochemical utilization of chemical energy carriers such as solid fuels must be decarbonized to achieve a climate-neutral circular economy as soon as possible, while remaining important for reliable electricity generation and stable economics. To accomplish this, extensive fundamental research is required to understand the underlying chemical and physical processes that can potentially be realized at an industrial scale. This paper reviews optical diagnostics used for particle-level combustion studies for clean power generation applications. The focus is on particle-resolved optical experiments for oxy-fuel coal combustion, biomass combustion, and utilization of iron in regenerative oxidation–reduction schemes. Previous studies are categorized by fuel and reactor types, investigated parameters, and experimental methodology. Phenomenological aspects of the multi-stage combustion process at the particle level are outlined using examples of bituminous coal and iron particle burning in hot gas. A selection of experimental studies is highlighted, with a particular methodological focus on measuring quantities at the particle level. These representative examples address relevant parameters, including particle number density, particle size and shape, surface temperature, ignition and combustion time, gas flame structure, gas temperature and species, nanoparticle formation, gas velocity, and particle dynamics. Finally, issues and problems that require further effort to improve diagnostics for solid fuel combustion studies are discussed.},

note = {P72},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{plank_external_2023,

title = {External Hydrogen Relations of the European Union: Framing Processes in the Public Discourse Towards and within Partner Countries},

author = { Friedrich Plank and Johannes Muntschick and Arne Niemann and Michèle Knodt},

url = {https://www.mdpi.com/2071-1050/15/20/14757},

doi = {10.3390/su152014757},

issn = {2071-1050},

year  = {2023},

date = {2023-10-11},

urldate = {2023-10-18},

volume = {15},

number = {20},

pages = {14757},

abstract = {With the need to decarbonize sectors that have hard-to-abate emissions, hydrogen as an energy carrier has increasingly gained attention. Within the European Union (EU) and its member states, hydrogen is assumed to be key for decarbonizing different sectors in the fight against climate change. Hence, state and private actors have engaged in a variety of attempts, strategies, and interests. However, energy security in Europe cannot be managed by European energy supply alone, despite high targets for the expansion of renewable energies. Rather, the EU will have to continue to rely on energy imports from partner countries. Against this backdrop, this paper seeks to provide an analysis of frame promotion processes generated by the EU’s bet on hydrogen. Drawing on a discourse analysis that is based on more than 32,000 media reports generated through the database Nexis, it conceptualizes the media debate as a carrier of frame alignment efforts by actors with a specific focus on the debates concerning external partner countries. It thus focuses on the discourses on the EU’s hydrogen approach in a complex environment with diverging interests of stakeholders from inside and outside the EU, thereby examining debates that still need further empirical research.},

note = {P90},

keywords = {{FF}4},

pubstate = {published},

tppubtype = {article}

}

@article{brockmann_pattern_2023,

title = {Pattern formations in particle laden drum flows and Taylor–Couette flows with co-rotating cylinders},

author = { P. Brockmann and M. Tvarozek and M. Lausch and J. Hussong},

url = {https://pubs.aip.org/pof/article/35/8/083304/2905149/Pattern-formations-in-particle-laden-drum-flows},

doi = {10.1063/5.0159908},

issn = {1070-6631, 1089-7666},

year  = {2023},

date = {2023-08-01},

urldate = {2023-09-12},

volume = {35},

number = {8},

pages = {083304},

abstract = {In this work, previously undescribed particle patterns are reported for suspensions of initially uniform dispersed non-Brownian particles in completely filled rotating drum flows and in completely filled co-rotating Taylor–Couette (TC) flows under the influence of gravity. Extending previous studies, a thorough phase mapping is performed for the drum flow with a low viscosity working liquid (1 cP) and dp≈500μm glass beads at a solid volume fraction of Φ=0.11%. A wide range of cylinder radii is covered (Ro=7–145 mm), and for the first time, a phase mapping is performed for a co-rotating TC flow for varying radius ratios. A total of 55 different geometrical combinations have been considered within the experiments. For both the drum and the TC flow, a series of clearly distinguishable patterns are observed including three different types of axial band structures as well as azimuthal band structures. The experiments indicate that in the case of the drum flow, the pattern formation strongly depends on the outer cylinder diameter, whereas in the case of the Taylor–Couette flow, the gap height has a strong effect on the pattern formation. In the TC case, it is observed that the wavelength of all band patterns shows a striking dependence on the cylinder radius and the curvature of the system.},

note = {P86},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{flath_hydrogen_2023,

title = {Hydrogen governance in Germany: a challenge for federal coordination},

author = { Lucas Flath and Jörg Kemmerzell and Michèle Knodt},

url = {https://www.tandfonline.com/doi/full/10.1080/13597566.2023.2232735},

doi = {10.1080/13597566.2023.2232735},

issn = {1359-7566, 1743-9434},

year  = {2023},

date = {2023-07-10},

urldate = {2023-08-14},

pages = {1–23},

note = {P10},

keywords = {{FF}4},

pubstate = {published},

tppubtype = {article}

}

@article{buchheiser_particle_2023,

title = {Particle and Phase Analysis of Combusted Iron Particles for Energy Storage and Release},

author = { Simon Buchheiser and Max Philipp Deutschmann and Frank Rhein and Amanda Allmang and Michal Fedoryk and Björn Stelzner and Stefan Harth and Dimosthenis Trimis and Hermann Nirschl},

url = {https://www.mdpi.com/1996-1944/16/5/2009},

doi = {10.3390/ma16052009},

issn = {1996-1944},

year  = {2023},

date = {2023-02-28},

urldate = {2023-09-06},

volume = {16},

number = {5},

pages = {2009},

abstract = {The combustion of metal fuels as energy carriers in a closed-cycle carbon-free process is a promising approach for reducing CO2 emissions in the energy sector. For a possible large-scale implementation, the influence of process conditions on particle properties and vice versa has to be well understood. In this study, the influence of different fuel–air equivalence ratios on particle morphology, size and degree of oxidation in an iron–air model burner is investigated by means of small- and wide-angle X-ray scattering, laser diffraction analysis and electron microscopy. The results show a decrease in median particle size and an increase in the degree of oxidation for leaner combustion conditions. The difference of 1.94 μm in median particle size between lean and rich conditions is twentyfold greater than the expected amount and can be connected to an increased intensity of microexplosions and nanoparticle formation for oxygen-rich atmospheres. Furthermore, the influence of the process conditions on the fuel usage efficiency is investigated, yielding efficiencies of up to 0.93. Furthermore, by choosing a suitable particle size range of 1 to 10 μm, the amount of residual iron content can be minimized. The results emphasize that particle size plays a key role in optimizing this process for the future.},

note = {P87},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{etzold_understanding_2021,

title = {Understanding the activity transport nexus in water and CO2 electrolysis: State of the art, challenges and perspectives},

author = { Bastian J.M. Etzold and Ulrike Krewer and Simon Thiele and Andreas Dreizler and Elias Klemm and Thomas Turek},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1385894721020878},

doi = {10.1016/j.cej.2021.130501},

issn = {13858947},

urldate = {2022-08-11},

volume = {424},

pages = {130501},

note = {P2},

keywords = {{FF}1},

pubstate = {published},

tppubtype = {article}

}

@article{debiagi_iron_2022,

title = {Iron as a sustainable chemical carrier of renewable energy: Analysis of opportunities and challenges for retrofitting coal-fired power plants},

author = { P. Debiagi and R.C. Rocha and A. Scholtissek and J. Janicka and C. Hasse},

url = {https://arxiv.org/abs/2205.11944v1},

doi = {10.1016/j.rser.2022.112579},

issn = {13640321},

urldate = {2022-09-02},

volume = {165},

pages = {112579},

note = {P1},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{wen_numerical_2023,

title = {Numerical modeling of pulverized iron flames in a multidimensional hot counterflow burner},

author = { Xu Wen and Arne Scholtissek and Jeroen van Oijen and Jeffrey Bergthorson and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218022005806},

doi = {10.1016/j.combustflame.2022.112572},

issn = {00102180},

urldate = {2023-01-07},

volume = {248},

pages = {112572},

note = {P37},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{belova_more_2023,

title = {The more the merrier? Actors and ideas in the evolution of German hydrogen policy discourse},

author = { Arina Belova and Christine Quittkat and Lukáš Lehotský and Michèle Knodt and Jan Osička and Jörg Kemmerzell},

url = {https://linkinghub.elsevier.com/retrieve/pii/S2214629623000257},

doi = {10.1016/j.erss.2023.102965},

issn = {22146296},

urldate = {2023-02-15},

volume = {97},

pages = {102965},

note = {P62},

keywords = {{FF}4},

pubstate = {published},

tppubtype = {article}

}

@article{kuhn_iron_2022,

title = {Iron as recyclable energy carrier: Feasibility study and kinetic analysis of iron oxide reduction},

author = { C. Kuhn and A. Düll and P. Rohlfs and S. Tischer and M. Börnhorst and O. Deutschmann},

url = {https://linkinghub.elsevier.com/retrieve/pii/S2666352X22000395},

doi = {10.1016/j.jaecs.2022.100096},

issn = {2666352X},

urldate = {2023-02-26},

volume = {12},

pages = {100096},

note = {P5},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fedoryk_experimental_2023,

title = {Experimental investigation of the laminar burning velocity of iron-air flames in a tube burner},

author = { Michal Fedoryk and Björn Stelzner and Stefan Harth and Dimosthenis Trimis},

url = {https://linkinghub.elsevier.com/retrieve/pii/S2666352X22000541},

doi = {10.1016/j.jaecs.2022.100111},

issn = {2666352X},

urldate = {2023-02-26},

volume = {13},

pages = {100111},

note = {P12},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{janicka_potential_2023,

title = {The potential of retrofitting existing coal power plants: A case study for operation with green iron},

author = { J. Janicka and P. Debiagi and A. Scholtissek and A. Dreizler and B. Epple and R. Pawellek and A. Maltsev and C. Hasse},

url = {https://arxiv.org/abs/2303.04000},

doi = {10.1016/j.apenergy.2023.120950},

issn = {03062619},

urldate = {2023-06-15},

volume = {339},

pages = {120950},

note = {P53},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{ning_multi-stage_2023,

title = {Multi-stage oxidation of iron particles in a flame-generated hot laminar flow},

author = { Daoguan Ning and Tao Li and Johannes Mich and Arne Scholtissek and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218023003267},

doi = {10.1016/j.combustflame.2023.112950},

issn = {00102180},

urldate = {2023-08-02},

volume = {256},

pages = {112950},

note = {P71},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{neumann_techno-economic_2023,

title = {Techno-economic assessment of long-distance supply chains of energy carriers: Comparing hydrogen and iron for carbon-free electricity generation},

author = { Jannik Neumann and Rodolfo Cavaliere Da Rocha and Paulo Debiagi and Arne Scholtissek and Frank Dammel and Peter Stephan and Christian Hasse},

url = {https://arxiv.org/abs/2303.00681},

doi = {10.1016/j.jaecs.2023.100128},

issn = {2666352X},

urldate = {2023-08-03},

volume = {14},

pages = {100128},

note = {P19},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{fradet_development_2022,

title = {Development of a Porous Solid Model for the Direct Reduction of Iron Ore Pellets},

author = { Quentin Fradet and Mohammed Liaket Ali and Uwe Riedel},

url = {https://onlinelibrary.wiley.com/doi/10.1002/srin.202200042},

doi = {10.1002/srin.202200042},

issn = {1611-3683, 1869-344X},

urldate = {2023-09-06},

volume = {93},

number = {12},

pages = {2200042},

abstract = {The direct reduction of iron ore pellets with syngas or hydrogen is a promising technology to reduce the CO 

 2 

 emissions of the iron and steel industry. The conversion rate of single iron ore pellets to iron is extensively investigated. In most of these studies, a shrinking core model is employed to reproduce the experimental observations. However, this model presents an inherent bias by assuming a sharp separation between a fully converted region and a fully unreacted one. Herein the present study, an improved porous solid model is proposed. This model solves the mass balances of the individual gas species and the solid ones assuming spherical symmetry. The governing equations, the main algorithm, and validation cases are presented. The present model also offers wide flexibility to incorporate complex phenomena such as porosity changes or carbon deposition. Furthermore, the proposed model is integrated into a computational fluid dynamics (CFD) environment. It is verified that identical input parameters yield almost identical results in both frameworks, opening the gate toward reliable CFD simulations of industrial‐scale reactors.},

note = {P89},

keywords = {{FF}1},

pubstate = {published},

tppubtype = {article}

}

@article{lausch_impact_2023,

title = {Impact of an ice particle onto a rigid substrate: Statistical analysis of the fragment size distribution},

author = { M. Lausch and L.M. Reitter and M. Schremb and J. Hussong},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0734743X23002427},

doi = {10.1016/j.ijimpeng.2023.104732},

issn = {0734743X},

urldate = {2023-09-12},

volume = {181},

pages = {104732},

note = {P29},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mich_comparison_2023,

title = {A comparison of mechanistic models for the combustion of iron microparticles and their application to polydisperse iron-air suspensions},

author = { Johannes Mich and Daniel Braig and Tobias Gustmann and Christian Hasse and Arne Scholtissek},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218023003255},

doi = {10.1016/j.combustflame.2023.112949},

issn = {00102180},

urldate = {2023-09-12},

volume = {256},

pages = {112949},

note = {P15},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{plank_hydrogen_2023,

title = {Hydrogen: Fueling EU‐Morocco Energy Cooperation?},

author = { Friedrich Plank and Britta Daum and Johannes Muntschick and Michèle Knodt and Christian Hasse and Ingrid Ott and Arne Niemann},

url = {https://onlinelibrary.wiley.com/doi/10.1111/mepo.12699},

doi = {10.1111/mepo.12699},

issn = {1061-1924, 1475-4967},

urldate = {2023-09-12},

pages = {mepo.12699},

abstract = {Abstract 

 The war in Ukraine and the looming threat of climate change are driving the strategic need to diversify sources of energy, including renewables. Therefore, the European Union aims to develop energy relations with non‐EU member states, and Morocco has become a key priority. Both Brussels and Rabat are pursuing ambitious green policies and cooperation initiatives, including on hydrogen. Drawing on theories of international institutions and political economy, this article analyzes hydrogen‐related relationship patterns and explains demand and supply factors as drivers of institutionalized energy cooperation. We examine the EU's hydrogen approach and development, its relations with Morocco, and the political interests of both sides. Our analysis shows that the complex interdependencies in the evolving EU‐Morocco hydrogen relations indicate that demand can be met by supply. However, challenges remain, including the need to deepen the partnership and prepare the market for commercial hydrogen production.},

note = {P11},

keywords = {{FF}4},

pubstate = {published},

tppubtype = {article}

}

@article{fradet_thermochemical_2023,

title = {Thermochemical reduction of iron oxide powders with hydrogen: Review of selected thermal analysis studies},

author = { Quentin Fradet and Michalina Kurnatowska and Uwe Riedel},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0040603123001211},

doi = {10.1016/j.tca.2023.179552},

issn = {00406031},

urldate = {2023-09-18},

volume = {726},

pages = {179552},

note = {P70},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{li_visualizing_2022,

title = {Visualizing particle melting and nanoparticle formation during single iron particle oxidation with multi-parameter optical diagnostics},

author = { Tao Li and Franziska Heck and Felix Reinauer and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218022003728},

doi = {10.1016/j.combustflame.2022.112357},

issn = {00102180},

urldate = {2022-09-14},

volume = {245},

pages = {112357},

note = {P9},

keywords = {{FF}2},

pubstate = {published},

tppubtype = {article}

}

@article{li_accurate_2023,

title = {Accurate determination of homogeneous ignition of single solid fuel particles enabled by machine learning},

author = { Tao Li and Zhangke Liang and Andreas Dreizler and Benjamin Böhm},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236122039953},

doi = {10.1016/j.fuel.2022.127171},

issn = {00162361},

urldate = {2023-08-02},

volume = {338},

pages = {127171},

note = {P16},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vance_flame_2023,

title = {Flame propagation modes for iron particle clusters in air, Part II: Transition from continuous to discrete propagation mode under strong convection effects},

author = { Faizan Habib Vance and Arne Scholtissek and Hendrik Nicolai and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218023005734},

doi = {10.1016/j.combustflame.2023.113199},

issn = {00102180},

urldate = {2024-02-22},

pages = {113199},

note = {P104},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vance_flame_2024,

title = {Flame propagation modes for iron particle clusters in air — Part I: Transition from continuous to discrete propagation mode under weak convection effects},

author = { Faizan Habib Vance and Arne Scholtissek and Hendrik Nicolai and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218023006399},

doi = {10.1016/j.combustflame.2023.113265},

issn = {00102180},

urldate = {2024-02-22},

volume = {260},

pages = {113265},

note = {P25},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{lausch_-situ_2024,

title = {In-situ iron oxide particle size and shape evolution during the dissolution in oxalic acid},

author = { M. Lausch and P. Brockmann and F. Schmitt and B.J.M. Etzold and J. Hussong},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0009250924001647},

doi = {10.1016/j.ces.2024.119864},

issn = {00092509},

urldate = {2024-02-26},

volume = {289},

pages = {119864},

note = {P30},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{dubal_chemical_2024,

title = {Chemical reactor network modeling in the context of solid fuel combustion under oxy-fuel atmospheres},

author = { Sören Dübal and Leon L. Berkel and Paulo Debiagi and Hendrik Nicolai and Tiziano Faravelli and Christian Hasse and Sandra Hartl},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124002424},

doi = {10.1016/j.fuel.2024.131096},

issn = {00162361},

urldate = {2024-02-28},

volume = {364},

pages = {131096},

note = {P54},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{krenn_evaluation_2024,

title = {Evaluation of a novel measurement method for the laminar burning speed in laminar lifted iron dust flames},

author = { Thomas Krenn and Tao Li and Janik Hebel and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124004137},

doi = {10.1016/j.fuel.2024.131266},

issn = {00162361},

urldate = {2024-03-04},

volume = {366},

pages = {131266},

note = {P106},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{spielmann_exploring_2024,

title = {Exploring the oxidation behavior of undiluted and diluted iron particles for energy storage: Mössbauer spectroscopic analysis and kinetic modeling},

author = { Jonas Spielmann and Daniel Braig and Antonia Streck and Tobias Gustmann and Carola Kuhn and Felix Reinauer and Alexandr Kurnosov and Oliver Leubner and Vasily Potapkin and Christian Hasse and Olaf Deutschmann and Bastian J. M. Etzold and Arne Scholtissek and Ulrike I. Kramm},

url = {https://xlink.rsc.org/?DOI=D3CP03484D},

doi = {10.1039/D3CP03484D},

issn = {1463-9076, 1463-9084},

urldate = {2024-04-11},

pages = {10.1039.D3CP03484D},

abstract = {Measuring the composition at different stages of oxidation enables extracting the kinetics and highlighting differences and similarities of iron particles to bulk material. 

 , 

 Iron is an abundant and non-toxic element that holds great potential as energy carrier for large-scale and long-term energy storage. While from a general viewpoint iron oxidation is well-known, the detailed kinetics of oxidation for micrometer sized particles are missing, but required to enable large-scale utilization for energy production. In this work, iron particles are subjected to temperature-programmed oxidation. By dilution with boron nitride a sintering of the particles is prevented enabling to follow single particle effects. The mass fractions of iron and its oxides are determined for different oxidation times using Mössbauer spectroscopy. On the basis of the extracted phase compositions obtained at different times and temperatures (600–700 °C), it can be concluded that also for particles the oxidation follows a parabolic rate law. The parabolic rate constants are determined in this transition region. Knowledge of the particle size distribution and its consideration in modeling the oxidation kinetics of iron powder has proven to be crucial.},

note = {P97},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vance_numerical_2024,

title = {A numerical analysis of multi-dimensional iron flame propagation using boundary-layer resolved simulations},

author = { Faizan Habib Vance and Arne Scholtissek and Hendrik Nicolai and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124009414},

doi = {10.1016/j.fuel.2024.131793},

issn = {00162361},

urldate = {2024-05-06},

volume = {369},

pages = {131793},

note = {P118},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{neumann_thermodynamic_2024,

title = {Thermodynamic assessment of an iron-based circular energy economy for carbon-free power supply},

author = { Jannik Neumann and Quentin Fradet and Arne Scholtissek and Frank Dammel and Uwe Riedel and Andreas Dreizler and Christian Hasse and Peter Stephan},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0306261924008596},

doi = {10.1016/j.apenergy.2024.123476},

issn = {03062619},

urldate = {2024-05-27},

volume = {368},

pages = {123476},

note = {P59},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nguyen_ignition_2024,

title = {Ignition and kinetic-limited oxidation analysis of single iron microparticles in hot laminar flows},

author = { Bich-Diep Nguyen and Daniel Braig and Arne Scholtissek and Daoguan Ning and Tao Li and Andreas Dreizler and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124010147},

doi = {10.1016/j.fuel.2024.131866},

issn = {00162361},

urldate = {2024-05-27},

volume = {371},

pages = {131866},

note = {P119},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{thater_influence_2024,

title = {The influence of clustering in homogeneous isotropic turbulence on the ignition behavior of iron particles},

author = { Gabriel Thäter and Maurizio Carbone and Tien-Duc Luu and Oliver T. Stein and Bettina Frohnapfel},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1540748924001585},

doi = {10.1016/j.proci.2024.105348},

issn = {15407489},

urldate = {2024-07-19},

volume = {40},

number = {1},

pages = {105348},

note = {P107},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{luu_carrier-phase_2024-1,

title = {Carrier-phase DNS study of particle size distribution effects on iron particle ignition in a turbulent mixing layer},

author = { T.D. Luu and A. Shamooni and A. Kronenburg and D. Braig and J. Mich and B.-D. Nguyen and A. Scholtissek and C. Hasse and G. Thäter and M. Carbone and B. Frohnapfel and O.T. Stein},

url = {https://linkinghub.elsevier.com/retrieve/pii/S154074892400107X},

doi = {10.1016/j.proci.2024.105297},

issn = {15407489},

urldate = {2024-07-19},

volume = {40},

number = {1},

pages = {105297},

note = {P108},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mich_modeling_2024,

title = {Modeling the oxidation of iron microparticles during the reactive cooling phase},

author = { Johannes Mich and Alisson Kwiatkowski Da Silva and Daoguan Ning and Tao Li and Dierk Raabe and Benjamin Böhm and Andreas Dreizler and Christian Hasse and Arne Scholtissek},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1540748924003468},

doi = {10.1016/j.proci.2024.105538},

issn = {15407489},

urldate = {2024-07-29},

volume = {40},

number = {1},

pages = {105538},

note = {P123},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{deutschmann_single_2024,

title = {Single iron particle combustion - A morphology study of partially oxidized iron particles},

author = { Max Philipp Deutschmann and Anton Sperling and Enrique Covini and Benjamin Böhm and Andreas Dreizler and Hermann Nirschl},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0032591024007460},

doi = {10.1016/j.powtec.2024.120102},

issn = {00325910},

urldate = {2024-08-08},

volume = {445},

pages = {120102},

note = {P115},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ning_temperature_2024,

title = {Temperature of burning iron microparticles with in-situ resolved initial sizes},

author = { Daoguan Ning and Tao Li and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218024004462},

doi = {10.1016/j.combustflame.2024.113737},

issn = {00102180},

urldate = {2024-09-23},

volume = {270},

pages = {113737},

note = {P128},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ning_quantitative_2024,

title = {A quantitative theory for heterogeneous combustion of nonvolatile metal particles in the diffusion-limited regime},

author = { Daoguan Ning and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218024004012},

doi = {10.1016/j.combustflame.2024.113692},

issn = {00102180},

urldate = {2024-09-23},

volume = {269},

pages = {113692},

note = {P124},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kuhn_micron-sized_2024,

title = {Micron-sized iron particles as energy carrier: Cycling experiments in a fixed-bed reactor},

author = { Carola Kuhn and Marco Kirn and Steffen Tischer and Olaf Deutschmann},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1540748924000178},

doi = {10.1016/j.proci.2024.105207},

issn = {15407489},

urldate = {2024-09-25},

volume = {40},

number = {1},

pages = {105207},

note = {P121},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{sperling_oxidation_2025,

title = {Oxidation progress and inner structure during single micron-sized iron particles combustion in a hot oxidizing atmosphere},

author = { Anton Sperling and Max P. Deutschmann and Daoguan Ning and Jonas Spielmann and Tao Li and Ulrike I. Kramm and Hermann Nirschl and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124022968},

doi = {10.1016/j.fuel.2024.133147},

issn = {00162361},

urldate = {2024-09-30},

volume = {381},

pages = {133147},

note = {P101},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ning_size-resolved_2024,

title = {Size-resolved ignition temperatures of isolated iron microparticles},

author = { Daoguan Ning and Yuhang Li and Tao Li and Benjamin Böhm and Andreas Dreizler},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010218024004887},

doi = {10.1016/j.combustflame.2024.113779},

issn = {00102180},

urldate = {2024-10-15},

volume = {270},

pages = {113779},

note = {P129},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vance_effect_2025,

title = {Effect of oxidizer composition on flame propagation modes in iron particle clusters},

author = { Faizan Habib Vance and Arne Scholtissek and Hendrik Nicolai and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236124026541},

doi = {10.1016/j.fuel.2024.133505},

issn = {00162361},

urldate = {2024-11-19},

volume = {381},

pages = {133505},

note = {P130},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{schwarzmeier_twophaseintertrackfoam_2025,

title = {twoPhaseInterTrackFoam: An OpenFOAM module for arbitrary Lagrangian/Eulerian interface tracking with surfactants and subgrid-scale modeling},

author = { Moritz Schwarzmeier and Suraj Raju and Željko Tuković and Mathis Fricke and Dieter Bothe and Tomislav Marić},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0010465524003837},

doi = {10.1016/j.cpc.2024.109460},

issn = {00104655},

urldate = {2024-12-20},

volume = {308},

pages = {109460},

note = {P131},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nguyen_nanoparticle_2025,

title = {Nanoparticle formation in the boundary layer of burning iron microparticles: Modeling and simulation},

author = { Bich-Diep Nguyen and Arne Scholtissek and Tao Li and Daoguan Ning and Oliver Thomas Stein and Andreas Dreizler and Christian Hasse},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1385894725008381},

doi = {10.1016/j.cej.2025.160039},

issn = {13858947},

urldate = {2025-02-07},

pages = {160039},

note = {P132},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{gossel_scale-bridging_2025,

title = {Scale-bridging within a complex model hierarchy for investigation of a metal-fueled circular energy economy by use of Bayesian model calibration with model error quantification},

author = { Lisanne Gossel and Elisa Corbean and Sören Dübal and Paul Brand and Mathis Fricke and Hendrik Nicolai and Christian Hasse and Sandra Hartl and Stefan Ulbrich and Dieter Bothe},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0306261925005069},

doi = {10.1016/j.apenergy.2025.125776},

issn = {03062619},

urldate = {2025-04-09},

volume = {390},

pages = {125776},

note = {P117},

keywords = {},

pubstate = {published},

tppubtype = {article}

}