References of "Pfennig, Andreas"
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See detailWieso müssen wir uns gut überlegen, wie wir die Landfläche nutzen?
Pfennig, Andreas ULiege

in Scientists For Future. One Minute Answers (2021)

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See detailEnergie- und Ressourceneinsparung durch Innovative und CFD-basierte Auslegung von Flüssig/Flüssig-Schwerkraftabscheidern
Steinhoff, Jan; Charlafti, Evgenia; Leleu, David ULiege et al

in Chemie Ingenieur Technik (2021), 93(7), 11521165

Computational-Fluid-Dynamics (CFD)-Simulationen in Kombination mit Tropfenpopulationsbilanzen führen zu einem praxisgerechten Standard, um auf Basis verfügbarer Prozessdaten den Strömungsverlauf – und ... [more ▼]

Computational-Fluid-Dynamics (CFD)-Simulationen in Kombination mit Tropfenpopulationsbilanzen führen zu einem praxisgerechten Standard, um auf Basis verfügbarer Prozessdaten den Strömungsverlauf – und damit die Verweilzeitverteilung – in liegenden Abscheidern beliebiger Größe zu berechnen. Durch Implementierung des Tropfenverhaltens wird auch die Berechnung eines tropfenspezifischen Abscheider-Wirkungsgrades ermöglicht. Die Methodenentwicklung erfolgte mit baugleichen Anlagen an drei verschiedenen Standorten. Die darauf beruhenden CFD-Simulationen wurden erfolgreich mit experimentellen Daten der beteiligten Industriepartner validiert. [less ▲]

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See detailAktionstag: Klimanotstand
Graf, Alexander; Hoehn, Mathias; Lehmann, Thomas et al

Speech/Talk (2021)

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See detailKlima-Wende-Zeit. Was uns Szenarien-Simulationen über die Zukunft erzählen
Pfennig, Andreas ULiege

Speech/Talk (2021)

Die Weltbevölkerung wächst rasant. Mehr als jeder zehnte Mensch hungert. Das verschärft die Herausforderungen beim Klimawandel. Um dies zu meistern, müssen wir neben der Energiewende auch bei ... [more ▼]

Die Weltbevölkerung wächst rasant. Mehr als jeder zehnte Mensch hungert. Das verschärft die Herausforderungen beim Klimawandel. Um dies zu meistern, müssen wir neben der Energiewende auch bei Entwicklungszusammenarbeit und Ernährung umdenken. Damit uns diese Einsicht persönlich bewegt und politische Kraft gewinnt, müssen wir persönlich begreifen, worauf es ankommt. Als Grundlage für die Wahl sinnvoller Maßnahmen zum Meistern der großen Herausforderungen der Menschheit eignen sich Szenarien-Simulationen. Es kommt darauf an, dass die zugrunde liegenden Modelle erlauben, den Einfluss verschiedener Maßnahmen abzubilden. Im Vortrag wird vorgestellt, wie solch ein Simulations-Tool basierend auf einfachen Annahmen den gesamtheitlichen Blick auf mögliche zukünftige Entwicklungen erlaubt. Die Ergebnisse werden dann visualisiert und diskutiert. So gelingen belastbare Aussagen darüber, welche Maßnahmen für die Menschheit besonders wichtig sind. [less ▲]

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See detailKlima-Wende-Zeit: #EUnited – gemeinsame Vision für die Zukunft
Pfennig, Andreas ULiege

Speech/Talk (2021)

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See detail16 Energie-Orientierungspunkte der Scientists for Future
Pfennig, Andreas ULiege; et al.

in 16 Energie-Orientierungspunkte der Scientists for Future (2021)

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See detailKlimaverträgliche Energieversorgung für Deutschland - 16 Orientierungspunkte
Gerhards, Christoph; Pfennig, Andreas ULiege; et al.

Report (2021)

As Germany's equitable contribution to meeting the global 1.5-degree limit, 16 points of orientation for a climate-compatible energy supply system are presented. It is assumed that for this to be realized ... [more ▼]

As Germany's equitable contribution to meeting the global 1.5-degree limit, 16 points of orientation for a climate-compatible energy supply system are presented. It is assumed that for this to be realized, German energy-related CO2 emissions will have to decline to zero within about 15 years. Energy conservation reduces the need for an expansion of renewable power generation capacities. The transport sector, redesigned industrial processes and building retrofits can significantly contribute to this. Nuclear energy is fraught with major risks. Besides, it cannot be scaled up suf-ficiently quickly. Using biomass as energy crops is inefficient and in conflict with other types of land use. Importing large amounts of carbon-neutral energy requires huge investments abroad. It is an unreliable option for the future. Therefore, the rapid expansion of photovoltaics (PV) and wind power in Germany is crucial. It is estimated that the electricity demand in 2030 can almost completely be met by renewables, if the capacities are expanded to about 350 GW of PV and about 150 GW of wind power. This expansion would enable supplying largely electrified mobility and heating systems as well as providing part of the required “green” hydro-gen in Germany. An average annual increase of around 30 GW of PV and around 9 GW of wind power will be required. This is about six times (PV) or three times (wind) as much as previously planned and will necessitate a significant societal effort. Delaying this expansion further would have to be compensated by even greater ef-forts in terms of drastic energy savings or imports of renewable energy. Overall, a delayed expansion of renewables would entail more difficulties than an ambitious expansion. Since it takes years to build capacity, it is possible to recalibrate efforts, for example, when it becomes apparent that a sufficiently large global import market is developing. Until then, out of responsibility for the future and in the spirit of the Paris Agreement, it is advisable to pursue the expansion targets outlined here. Green hydrogen (i.e. hydrogen produced from renewable energies) and derived syn-thesis products are necessary for the decarbonization of industrial processes, air transport and shipping as well as for securing energy supply for periods when solar and wind power generation is very low. However, without drastically raising the above-mentioned expansion targets for wind and solar even higher, these products will not be available in sufficient quantities for road transport and heat supply. Tech-niques to balance electricity supply and demand are available and should be speedily developed and expanded. These include electricity exchange with neighboring coun-tries, demand management and energy storage. It is advisable to quickly create im-proved legal frameworks, to integrate these technologies, and to expand electricity grids. In the medium to long term, the costs of a climate-compatible energy system are no higher than currently. At the same time, employment and export opportunities are generated in Germany through the development, operation and maintenance of a renewable-based energy system and the energy-efficient retrofitting of buildings. The political framework will determine whether Germany's climate-compatible en-ergy supply system succeeds. [less ▲]

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See detailTool and Workflow for Systematic Design of Reactive Extraction for Separation and Purification of Valuable Components
Benkoussas, Hana ULiege; Leleu, David ULiege; Satpathy, Swagatika ULiege et al

in Azimi, Giselle; Ouchi, Takanari; Forsberg, Kerstin (Eds.) et al Rare Metal Technology 2021 (2021, March 16)

Rare-earth metals, such as La(III), Nd(III), Eu(III), or Y(III), which are recycled from electronic waste in urban mining, can be separated and purified utilizing reactive extraction. Process development ... [more ▼]

Rare-earth metals, such as La(III), Nd(III), Eu(III), or Y(III), which are recycled from electronic waste in urban mining, can be separated and purified utilizing reactive extraction. Process development and equipment design then aim to determine the optimal reactive extractant, diluent, any additional components, equipment type, structure of the equipment internals, as well as all process parameters. This requires a deep understanding of the CHEMISTRY of the underlying complexing reactions as well as ENGINEERING expertise on extraction-process development as well as equipment design. To aid this design task, a tool was developed based on cascaded option trees which combines the expertise from both sciences. Process design is supported by a prototypic work flow and by systematically structured and quantitative information on the underlying thermodynamics. The method is also applicable for extraction of diluted components from aqueous solutions, as encountered in fermentation broth in the context of bio-economy. The method will be presented and applied to examples from urban mining. [less ▲]

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See detailExtraction of metals from P-rich sludge liquor: from lab to pilot scale
Shariff, Zaheer Ahmed ULiege; Leleu, David ULiege; Léonard, Angélique et al

Conference (2021, February 04)

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See detailSettling Experiments With Iso-Optical Systems for Coalescence-Model Validation
Leleu, David ULiege; Pfennig, Andreas ULiege

Conference (2021, February 04)

Design of settlers can be challenging, since coalescence behavior varies widely between systems. For settler design, a numerical tool has been developed, which is based on considering the behavior if ... [more ▼]

Design of settlers can be challenging, since coalescence behavior varies widely between systems. For settler design, a numerical tool has been developed, which is based on considering the behavior if individual representative drops (ReDrop concept). In these simulations, the coalescence modeling is a major challenge due to the complex interactions of drops upon approach and coalescence. A consistent coalescence model has been proposed in the past and a standardized settling cell developed, which allows quantitative analysis of settling behavior for a specific material system. The settling cell is lighted with an LED panel from behind to ensure proper lighting and a video taken of the batch-settling experiment, which is then quantitatively evaluated. For validation of the coalescence model, quantitative data on the time-dependent holdup profile in this standardized settling cell is desired. This can be obtained by utilizing an iso-optical system, to which a dye is added. In an iso-optical system the refractive index of both liquid phases is identical so that refraction at the interface vanishes. Thus, in an iso-optical system, a dispersion appears fully transparent. Adding a dye, which partitions preferentially into one phase, then allows to quantify how much of that phase is present at any height position in the cell. To determine the drop-size distribution with a SOPAT-Probe, which is inserted into the settling cell, slight concentration changes are introduced so that the interfaces become visible and can be detected with the help of this optical probe and thus accessible to evaluation. The time-dependent holdup profile is automatically evaluated from the video taken. This evaluation also includes some corrections e.g. for inhomogeneities of LED panel used for lighting the cell as well as the camera. These quantitative data on drop sizes and time-dependent holdup are then used as a basis to validate some fundamental aspects of the coalescence modelling. The experiments e.g. clearly show the presence of a densely-packed zone in addition to the close-packed zone, which is usually assumed. In this densely-packed zone the drops are not in direct contact but settle freely at high values of holdup. This has to be appropriately modelled in the settling model. The densely-packed zone previously had been suspected from the ReDrop modelling but is now quantified experimentally (Leleu, Pfennig, 2019). The results of the ReDrop simulation are in good agreement with the experimental data. [less ▲]

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See detailMeasurement of Relative Electrostatic Potential Difference for Coalescence Modelling
Leleu, David ULiege; Pfennig, Andreas ULiege

in Chemie Ingenieur Technik (2021), accepted, preview

Coalescence is strongly affected by trace components. Studies suggest to use the DLVO force in coalescence modelling. Data regarding the electrostatic potential are thus needed. Determination of the ... [more ▼]

Coalescence is strongly affected by trace components. Studies suggest to use the DLVO force in coalescence modelling. Data regarding the electrostatic potential are thus needed. Determination of the partition coefficient of a charged dye dissolved in salt-containing two-phases systems allows to evaluate the electrostatic potential difference relative to a reference system by evaluation with the extended Albertsson model. The corresponding first settling tests show the strong effect of the relative electrostatic potential difference on the dispersion behavior. [less ▲]

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See detailKlima-Wende-Zeit
Pfennig, Andreas ULiege

Scientific conference (2020, December 22)

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See detailScientists for Future empfiehlt eine repräsentative Klima-Bürger:innenversammlung im Jahr 2021 (Version 1.0)
Hagedorn, Gregor; Pfennig, Andreas ULiege

E-print/Working paper (2020)

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See detailPhosphorus flows, recovery and recycling from wastewater
Shariff, Zaheer Ahmed ULiege; Léonard, Angélique ULiege; Pfennig, Andreas ULiege

Speech/Talk (2020)

This course will introduce the students to human enhanced phosphorus cycle from a global and an EU perspective. The P losses and concepts for sustainable P use will be discussed. The synergism between the ... [more ▼]

This course will introduce the students to human enhanced phosphorus cycle from a global and an EU perspective. The P losses and concepts for sustainable P use will be discussed. The synergism between the need for phosphorus removal from wastewater and its recovery will be emphasized. The different pathways for P removal from wastewater and recovery will be covered with examples of current research activity in the field of P recovery. Recovered P product value chain and drivers for the use of recovered P products will be discussed. The new EU fertilizer regulation that will come into effect in 2022 and its impact on P recycling will be discussed The course will provide a global perspective to the students for sustainable P use and P re-covery. The course will also inform students on the technological aspects and advancements for P recovery and the challenges that have to be addressed. [less ▲]

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See detailKlima-Realitäts-Check 2020
Pfennig, Andreas ULiege

Report (2020)

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See detailSeparation and Purification 2020
Pfennig, Andreas ULiege

Report (2020)

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See detailMüllers Lust - Klima-Wende-Zeit
Pfennig, Andreas ULiege

Speech/Talk (2020)

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See detailFischers Fritze - Klima-Wende-Zeit
Pfennig, Andreas ULiege

Speech/Talk (2020)

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