Suchergebnisse

Ajuts: Dimitrios Komilis is grateful to the TECNIOspring fellowship programme (TECSPR13-1-0006) which was co-financed by the European Union through the Marie Curie Actions and ACCIÓ (Generalitat de Catalunya) ; Innovative gas capture technologies with the objective to mitigate CO₂ and CH₄ emissions are discussed in this review. Emphasis is given on the use of nanoparticles (NP) as sorbents of CO₂ and CH₄, which are the two most important global warming gases. The existing NP sorption processes must overcome certain challenges before their implementation to the industrial scale. These are: i) the utilization of the concentrated gas stream generated by the capture and gas purification technologies, ii) the reduction of the effects of impurities on the operating system, iii) the scale up of the relevant materials, and iv) the retrofitting of technologies in existing facilities. Thus, an innovative design of adsorbents could possibly address those issues. Biogas purification and CH₄ storage would become a new motivation for the development of new sorbent materials, such as nanomaterials. This review discusses the current state of the art on the use of novel nanomaterials as adsorbents for CO₂ and CH₄. The review shows that materials based on porous supports that are modified with amine or metals are currently providing the most promising results. The Fe₃O₄-graphene and the MOF-117 based NPs show the greatest CO₂ sorption capacities, due to their high thermal stability and high porosity. Conclusively, one of the main challenges would be to decrease the cost of capture and to scale-up the technologies to minimize large-scale power plant CO₂ emissions.

Climate-smart cropping systems should be designed with three objectives: reducing greenhouse gas (GHG) emissions, adapting to changing and fluctuating climate and environment, and securing food production sustainably. Agriculture can improve the net GHG emissions balance via three levers: less N2O, CH4 and CO2 emissions, more carbon storage, and green energy production (agrifuels, biogas). Reducing the application of mineral N fertilizer is the main option for reducing N2O emissions either directly or by increasing the proportion of legumes in the rotation. The most promising options for mitigating CH4 emissions in paddy fields are based on mid-season drainage or intermittent irrigation. The second option is storing more carbon in soil and biomass by promoting no-tillage (less fuel, crop residues), sowing cover crops, introducing or maintaining grasslands and promoting agroforestry. Breeding for varieties better adapted to thermal shocks and drought is mainly suggested as long-term adaptation to climate change. Short-term strategies have been identified from current practices to take advantage of more favorable growing conditions or to offset negative impacts: shifting sowing dates, changing species, cultivars and crop rotations, modifying soil management and fertilization, introducing or expanding irrigation. Some crops could also move to more suitable locations. Model-based tools and site-specific technologies should be developed to optimize, support and secure farmer's decisions in a context of uncertainty and hazards. Most of the adaptation and mitigation options are going in the same way but trade-offs will have to be addressed (e.g. increasing the part of legumes will be possible only with significant breeding efforts). This will be a challenge for designing cropping systems in a multifunctional perspective.

Efficient storage of solar and wind power is one of the most challenging tasks still limiting the utilization of the prime but intermittent renewable energy sources. The direct storage of concentrated solar power in renewable fuels via thermochemical splitting of water and carbon dioxide on a redox material is a scalable approach with up to 54% solar-to-fuel conversion efficiency. Despite progress, the search for earth-abundant materials that can provide and maintain high H2 and CO production rates over long period of high-temperature cycles continues. Here, we report a strategy to unlock the use of manganese, the 12th most abundant element in the Earth's crust, for thermochemical synthesis of solar fuels, achieving superior thermochemical stability, oxygen exchange capacity, and up to seven times higher mass-specific H2 and CO yield than cerium dioxide. We observe that incorporation of a small fraction of cerium ions in the manganese (II,III) oxide crystal lattice drastically increases its oxygen ion mobility, allowing its reduction from oxide to carbide during methane partial oxidation with simultaneous Ce exsolution. High CO2 and H2O splitting rates are achieved by re-oxidation of the carbide to manganese (II) oxide with simultaneous reincorporation of the cerium ions. We demonstrate that the oxide to carbide reaction is highly reversible achieving remarkable CO2 splitting rates over 100 thermochemical cycles of methane partial oxidation and CO2 splitting, and preserving the initial oxygen exchange capacity of 0.65 molO and 89% of the fuel production rates. Due to this extraordinarily high reversible oxygen exchange capacity, the 3% Ce-doped manganese oxide achieves an average mass-specific CO yield for CO2 splitting of 17.72 mmolCO g−1, which is significantly higher than that previously achieved in thermochemical redox cycles. More generally, these findings suggest that incorporation of small soluble amounts of cerium in earth-abundant transition metal oxides like manganese oxide is a powerful approach to enable solar thermochemical fuel synthesis. ; This research was performed as part of the Australian Solar Thermal Research Initiative (ASTRI), a project supported by the Australian Government, through the Australian Renewable Energy Agency (ARENA). Financial support from the ARC Discovery Project #150101939 and the ARC Discovery Early Career Award #160100569 (A. Tricoli), the ARC Future Fellowship FT140101213 (W. Lipiński), the Australian Government Research Training Program (X. Gao), The Hong Kong Research Grants Council through the Early Career Scheme Project #25301617 (Y. Zhu) and The Hong Kong Polytechnic University internal Grant 1-ZE6G (Y. Zhu) is gratefully acknowledged.

Double-walled oxide nanotube structures are interesting for a wide range of applications, from photocatalysis to drug delivery. In this work, a progressive oxidation method to fabricate double-walled nanotube structures is reported in detail. The approach is based on the electrodeposition of metallic iron nanowires, in porous alumina templates, followed by a selective chemical etching, nanoscale Kirkendall effect, a fast oxidation and out-diffusion of the metallic core structure during thermal annealing. To validate the formation mechanism of such core-shell structure, chemical composition and atomic structure were assessed. The resulting hematite nanotubes have a high degree of uniformity, along several microns, and a nanoscopic double-walled structure. ; J. Azevedo would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for funding (CEECIND/03937/2017). C.T. Sousa thanks FCT for financial support through the Investigador FCT program (Contract No. IF/01159/2015). M.P. Fernández-García acknowledges financial support through Spanish MINECO (research project RTI2018-094683-B-C52); Gobierno del Principado de Asturias and FICyT (through research project FC-GRUPIN-IDI/2018/000185) and University of Oviedo for R&D project 2018/00061/008 in the competitive call PAPI-18-EMERG-8. The authors are thankful to Elettra Sincrotrone for allocating beam-time and their experimental facilities. This work was partially supported by the Project POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy – LEPABE and "SunStorage - Harvesting and storage of solar energy", with reference POCI-01-0145-FEDER-016387, funded by European Regional Development Fund (ERDF), through COMPETE 2020 - Operational Programme for Competitiveness and Internationalization (OPCI), by FCT - Portuguese Foundation for Science and Technology I.P. This work was financially supported by: Project PTDC/EQU-EQU/30510/2017 - POCI-01-0145-FEDER-030510 – Sunflow "Solar energy storage into redox flow batteries" funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. This work was also supported by the Portuguese Fundação para a Ciência e Tecnologia (FCT) and COMPETE 2020 (FEDER) under the projects POCI-01-0141-FEDER-032527, PTDC/FIS-MAC/31302/2017, MIT-EXPL/IRA/0012/2017, PTDC/CTM-CTM/28676/2017 and PTDC/FIS-OTI/32257/2017 and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 734801. ; Peer reviewed

Die Auswahl eines geeigneten Arbeitsfluides ist bei der Auslegung thermodynamischer Kreisprozesse ein entscheidender Schritt, da sowohl das Betriebsverhalten als auch die Effizienz der Prozesse maßgeblich durch die ausgewählten Fluide beeinflusst werden. Zu dem großen Bereich thermodynamischer Kreisprozesse gehören grundsätzlich etablierte Energiewandlungsprozesse mit langer Historie wie Kompressionskältemaschinen und -wärmepumpen im niedrigen bis mittleren Temperaturbereich. Außerdem werden auch immer wieder neue Prozesse bzw. Anwendungen wie Hochtemperaturwärmepumpen oder Strom-Wärme-Strom-Speichersysteme diskutiert. Nicht nur für solche neuartigen Prozesse bzw. Randbedingungen stellt sich stets die Frage nach geeigneten und effizienten Fluiden, sondern auch für die etablierten Prozesse, für die auf Grund der aktuellen Problematik der hohen Treibhauswirksamkeit vieler Kältemittel zeitnah alternative Arbeitsmittel gefunden werden müssen. Bisher waren die Fluidauswahlmethoden allerdings häufig unstrukturiert und beruhten nicht auf grundlegendem thermodynamischen Verständnis, sondern meist auf dem Prinzip Versuch und Irrtum oder auf sehr einfachen Heuristiken. Im Rahmen dieser Arbeit werden Methoden der Fluidauswahl für zwei Teilbereiche der thermodynamischen Energiewandlungsprozesse diskutiert, die bislang nicht ausreichend betrachtet wurden. Dies sind existierende Anlagen und Anlagenkonzepte von Kompressionskälte- maschinen und -wärmepumpen sowie auf dem Clausius-Rankine-Prozess basierte Strom-Wärme-Strom-Speichersysteme, wobei die Anknüpfungspunkte hierbei auf Grund der bis-herigen Kenntnisstände deutlich voneinander abweichen. Strom-Wärme-Strom-Speicher sind ein jüngst diskutierter Ansatz zur großtechnischen Speicherung elektrischer Energie. Eine mögliche Konfiguration dieses Konzepts ist die Kombination zweier Clausius-Rankine-Prozesse (Wärmepumpe und Organic Rankine Cycle) mit einem thermischen Energiespeicher. Der bisherige Kenntnisstand zu dieser Technologie kann prinzipiell als in der Anfangsphase befindlich bezeichnet werden. Der Einfluss des Fluides, generell infrage kommende Arbeitsmittel, vielversprechende Betriebsbedingungen und thermodynamische Grenzen der Effizienz sind bisher weitestgehend unbekannt. Zur Untersuchung dieser Punkte werden im Rahmen dieser Arbeit Strom-Wärme-Strom-Systeme, bestehend aus zwei Clausius-Rankine-Prozessen und einem idealen isothermen Speicher, modelliert, wobei die Irreversibilitäten der Prozesse schrittweise gesteigert werden. Die berücksichtigten Arbeitsfluide sind hierbei zunächst hypothetische Fluide, deren Parameter hinsichtlich des Prozesses und einiger Randbedingungen optimiert werden. Im weiteren Verlauf werden außerdem potenziell existierende Arbeitsmittel identifiziert. Die Untersuchung zeigt grundsätzlich für steigende Speichertemperaturen sinkende Wirkungsgrade und steigende Leistungen. Weiterhin geht aus der Untersuchung hervor, dass Leistungsabgabe und Wirkungsgrad bei konstanter Speichertemperatur zu einer Pareto-Front führen: bei der eine Leistungsabgabe nahe am Maximalwert zu einer deutlichen Reduktion des Wirkungsgrades führt. In diesem Zusammenhang wird ein Kompromissprozess vorgeschlagen, der beispielsweise für eine Speichertemperatur von 350 K und unter Berücksichtigung typischer isentroper Wirkungsgrade einzelner Komponenten mit dem optimierten hypothetischen Fluid einen Wirkungsgrad von 30 % aufwies. Aus der Fluidauswahl für diesen Prozess resultierte schließlich Ethylamin als bestes Fluid mit einem vorhergesagten Wirkungsgrad von 25,6 %. Im Bereich der bereits ausgelegten Kältemaschinen und Wärmepumpen stehen im Rahmen dieser Arbeit Verfahren zur Identifizierung geeigneter Substitutionsfluide im Zentrum. Auf Grund der aktuellen Gesetzgebung müssen zeitnah Ersatzfluide für zahlreiche konkrete Anlagen mit unterschiedlichen Randbedingungen gefunden werden. Ein theoretisches Modell zur individuellen Fluidauswahl kann hierbei eine entscheidende Hilfe sein. Gegenwärtig ist allerdings nicht klar, mit welchem Detaillierungsgrad eine konkrete Anlage in einem Modell abgebildet werden muss, um eine verlässliche Fluidempfehlung zu erhalten. Zur Erörterung dieser Frage wurden Kreisprozessmodelle unterschiedlicher Komplexität anhand von Messwerten, gewonnen für verschiedene Fluide mit einer Wärmepumpenversuchsanlage, überprüft. Die Modellierungen höherer Komplexität beinhalten hierbei ein eigens entwickeltes Modell zur fluidabhängigen Bestimmung isentroper Wirkungsgrade und Liefergrade des Verdichters. Aus der Untersuchung resultiert grundsätzlich, dass die Berechnung der unterschiedlichen Prozessgrößen an Genauigkeit bezogen auf die Messungen gewinnt, wenn der Detaillierungsgrad der Modellierung gesteigert wird. Allerdings hat sich auch gezeigt, dass vor allem das Modell zur Berechnung isentroper Wirkungsgrade und Liefergrade des Verdichters für eine valide Auswahl von Substitutionsfluiden unerlässlich ist. Aus den Erkenntnissen wurde schließlich ein schrittweises Verfahren zur Auswahl geeigneter Substitutionsfluide entwickelt und vorgeschlagen. ; The selection of a suitable working fluid is a decisive factor in the design of thermodynamic cycles, since both the operating behaviour and the efficiency of the processes are significantly influenced by the selected fluids. The extensive field of thermodynamic cycles basically includes established energy conversion processes with a long history, such as vapour compression refrigeration cycles and heat pumps in the low to medium temperature ranges. Furthermore, new processes and applications such as high-temperature heat pumps or pumped heat electricity storages (PHES) are constantly being addressed. The question of suitable and efficient fluids arises not only for these new processes and new applications, but also for the established processes for which, due to the current problem of the high global warming potential of many refrigerants, alternative working fluids must be quickly identified. To date, however, the methods of fluid selection have often been unstructured and were not based on basic thermodynamic understanding, but mostly on the principle of trial and error or on very simple heuristics. Within the scope of this study, methods of fluid selection for two sub-areas of thermodynamic energy conversion processes are discussed which have so far not been adequately addressed. These include existing vapour compression refrigeration cycles and heat pumps, as well as Rankine-cycles-based PHES systems, whereby the starting points differ considerably due to the current state of knowledge. Pumped heat electricity storage is a recently discussed approach to the large-scale storage of electrical energy. One possible configuration of this concept is the combination of two Rankine-cycles (heat pump and organic rankine cycle) with a thermal energy storage system. The current state of knowledge on this technology can, in principle, be described as being in the initial phase. The influence of the fluid, generally applicable working fluids, promising operating conditions and thermodynamic limits of efficiency, are as yet largely unknown. In order to investigate these points, pumped heat electricity storage systems consisting of two Rankine cycles and an ideal isothermal storage system are modelled, whereby the irreversibilities of the processes are gradually increased. The working fluids taken into account are initially hypothetical fluids whose parameters are optimised with regard to the process and specific boundary conditions. During the further course, promising existing working fluids will also be identified. The investigation essentially shows decreasing efficiencies and increasing values of the power output for rising storage temperatures. Furthermore, it is shown that power output and efficiency at constant storage temperatures lead to a Pareto front: power output close to the maximum value leads to a significant reduction in efficiency. In this context, a compromise cycle is proposed which, for example at a storage temperature of 350 K and taking into account typical isentropic efficiencies of individual components, has an efficiency of 30 % when using the optimised hypothetical fluid. The fluid selection for this process resulted in ethylamine as the best fluid with a predicted efficiency of 25.6 %. In the field of specific refrigerating cycles and heat pumps, this investigation focuses on methods for identifying suitable drop-in fluids. Due to current legislation, drop-in fluids must quickly be found for numerous existing systems with different boundary conditions. A theoretical model for individual fluid selection can be a decisive aid here. However, it is currently not clear with what level of detail a specific system must be mapped in a model in order to obtain a reliable fluid recommendation. In discussing this question, process cycle models of varying complexity were examined on the basis of measured values obtained for different fluids with a heat pump test rig. The models of higher complexity includes a specially developed model for the fluid-dependent calculation of isentropic and volumetric efficiencies of the compressor. As a result of the investigation, the calculation of the different process variables gains in accuracy, compared to the measurements, when the detail levels of the modelling is increased. However, it has also been shown that the model for calculating isentropic and volumetric efficiencies of the compressor in particular is indispensable for a valid selection of substitute fluids. Finally, a step-by-step procedure for the selection of suitable substitute fluids has been developed and proposed on the basis of the findings.

Allein durch die zunehmende Nutzung erneuerbarer Energien werden nationale und internationale Klimaziele und energiepolitische Ziele nicht umsetzbar sein. Für eine Realisierung der Energiewende ist auch das Definieren und Umsetzen von energieeffizienten Maßnahmen unumgänglich. Daher werden im Rahmen dieser Arbeit Ansätze entwickelt, die eine energetische Bewertung komplexer industrieller Prozesse ermöglichen. Durch das Anwenden des Physikalischen Optimums (PhO), das ein auf den physikalischen Gesetzen basierender Referenzwert ist, wird eine gezielte Optimierung der Prozesse hin zu besagtem Grenzwert möglich. Zur Weiterentwicklung der methodischen Anwendung des PhOs definiert die Arbeit zunächst energietechnische Begriffe für dessen Anwendung, um einen einheitlichen Sprachgebrauch und vor allem eine einheitliche Anwendung der Methode zu gewährleisten. Durch das Einführen der bilanziellen Methode wird erstmals ein systematisches Vorgehen zur Definition des PhOs geschaffen, das auf energetischen Bilanzen basiert. Dies ermöglicht eine einheitliche, nachvollziehbare, objektive und reproduzierbare Definition von physikalisch begründeten Grenzwerten. Die bilanzielle Methode baut auf der Unterscheidung zwischen vermeidbaren und unvermeidbaren Verlusten auf und wird im Rahmen der Arbeit wiederholt angewendet und verifiziert. Durch eine Unterscheidung zwischen vermeidbaren und unvermeidbaren Verlusten können indirekte PhO-Faktoren bestimmt werden. Sie ermöglichen eine gezielte Prozessoptimierung, da in ihnen die optimierbaren Prozessverluste definiert sind. Zur Bewertung komplexer Prozesse ist zuerst der nötige Detailgrad festzulegen. Die Arbeit schlägt ein Vorgehen vor, das für eine Effizienzbewertung relevante Subprozesse identifiziert. Die einzelnen Subprozesse können mit Hilfe der bilanziellen Methode gekoppelt werden, um einen Gesamt-PhO-Faktor des Prozesses zu ermitteln. Dieser kann sowohl auf Planungs- als auch auf Bestandsprozesse angewendet werden. Zur Bewertung unterschiedlicher Prozessphasen wird ein systematisches Vorgehen zur Definition entsprechender Kennzahlen vorgeschlagen. Eine Anwendung der bilanziellen Methode bei unzureichender Messtechnik kann anhand eines Bottom-Up-Vorgehens ermöglicht werden. Da durch das Eingliedern erneuerbarer Energiequellen eine zeitliche und räumliche Diskrepanz zwischen Energiebereitstellung und Energienutzung entstehen kann, gewinnt der Einsatz energetischer Speicher zunehmend an Bedeutung. Auf Basis der bilanziellen Methode wird ein Vorgehen entwickelt, mit dem verschiedene Speichertechnologien hinsichtlich ihrer Effizienz bewertet werden können. Das Vorgehen wird anhand eines Druckluftspeichers, eines Kondensators und eines thermischen Speichers validiert. Da anhand der Exergie die Qualität einer Energie bewertet werden kann und sie die maximale Arbeitsfähigkeit beschreibt, ist eine Abgrenzung vom PhO zur Exergie erforderlich. Im Rahmen dieser Arbeit wird daher anhand verschiedener technischer Prozesse eine Einordnung bzw. Abgrenzung vom PhO zur energetischen und exergetischen Prozessbewertung durchgeführt. Stichpunkte: Prozess, Bewertung, Effizienz, Energie, Exergie, Grenzwert, Physikalisches Optimum, Optimierung ; Solely by increasing the use of renewable energies, national and international climate and energy political targets cannot be achieved. Defining and implementing energy-efficient measures is essential to realize the energy transition. Within the scope of this work, approaches are developed to evaluate the energy efficiency of complex industrial processes. By applying the Physical Optimum (PhO), which is a reference value based on the laws of physics, a targeted optimization of processes towards said limit value becomes possible. To further develop the methodological application of the PhO, the thesis initially defines energy-related terms for the application of the PhO. Thus a uniform use of language and, above all, a uniform application of the method is ensured. The balancing method is introduced for the first time. It is a systematic approach which defines the PhO based on energy balances and therefore enables a uniform, comprehensible, objective and reproducible definition of limiting values. The balancing method builds on the distinction between avoidable and unavoidable losses and is constantly applied and verified within the scope of this work. By distinguishing between avoidable and unavoidable losses, indirect PhO-factors can be determined. They allow a targeted process optimization since the process losses that can be optimized are defined by them. To evaluate complex processes, the necessary level of detail must be determined at first. This work proposes an approach that identifies sub-processes relevant for an efficiency evaluation. The individual subprocesses can be combined using the balancing method to determine an overall PhO-factor for the process. This can be applied to both planned and existing processes. In order to evaluate different process phases, a systematic method is proposed for defining appropriate performance indicators. An application of the balancing method in case of insufficient measurement technologies can be realized by means of a bottom-up approach. Since the integration of renewable energy sources can lead to a temporal and geographical discrepancy between energy supply and energy use, the use of energy storage systems is becoming increasingly important. Based on the balancing method, a method is developed to evaluate different storage technologies regarding their efficiency. The procedure is validated based on a compressed-air energy storage unit, a capacitor and a thermal energy storage unit. Since exergy can be used to evaluate the quality of energy and describes the maximum working capability, it is necessary to distinguish between PhO and exergy. In the context of this work, a classification respectively a differentiation from PhO to energetic and exergetic process evaluation is carried out based on different technical processes. Keywords: process, evaluation, efficiency, energy, exergy, limit value, Physical Optimum, optimization

The feasibility of the reduction of CO2 to CH4 employing MgH2 in the presence and absence of cobalt as a catalyst was investigated for the first time, exploring different non-independent reaction conditions such as the grade of microstructural refinement, the molar ratio MgH2 : CO2, reaction time and temperature. For the un-catalyzed process a methane yield of 44.6% was obtained after 24 h of thermal treatment at 400 °C employing a molar ratio of 2 : 1, through a methanation mechanism that involves the direct reduction of CO2 and the generation of CH4via C as an intermediary. For the MgH2 catalyzed process a methane yield of 78% was achieved by heating at 350 °C for 48 h, 4 : 1 being the optimal molar ratio. The global mechanism corresponds to a Sabatier process favored by Co as an active catalyst, together with the reverse water gas shift reaction followed by methanation of CO in the presence of steam. On account of the fact that it was proved that the use of the catalyst allows lowering the operational temperature without collapsing the methane yield, this research provides interesting insight into a thermochemical method for CO2 reduction to CH4 employing a solid hydrogen storage medium as an H2 source. ; The present work is part of the CO2MPRISE, ''CO2 absorbing Materials Project-RISE'', a project that has received funding from the European Union's Horizon 2020 research and innovation programme, under the Marie Skłodowska-Curie Grant Agreement No. 734873. The work was also supported by CONICET (Consejo Nacional de Investigaciones Cientı´ficas y Te´cnicas), ANPCyT-(Agencia Nacional de Promocio´n Cientı´fica y Tecnolo´gica) and CNEA (Comisio´n Nacional de Energı´a Ato´mica)

This report takes on an energy system perspective to quantify the benefits of energy efficiency in the European heating and cooling sector. This holistic approach enables to take into account sectors and systems interconnections in new ways. Doing so reveals significant results: for a future low-carbon EU energy system it is essential that energy efficiency measures on the supply side, like district energy, are considered with equal importance for decarbonisation as measures on the demand side, like heat savings. They are fundamental to the technical and economic viability of the Smart Energy System. District energy enables the use of sustainable energy that otherwise could not be utilised e.g. geothermal, industrial waste heat, solar thermal. District heating is essential for low-cost energy storage and creates an important link to the electricity sector via large-scale heat pumps. A more interconnected energy system enables sector integration. In the same way, district cooling often offer a direct opportunity to use the extracted heat in other applications e.g. district heating thus representing yet another synergy opportunity. Based on the Heat Roadmap Europe project series, this report elaborates an investment roadmap and policy recommendations to implement the Heat Roadmap Europe scenario in 2050. To reach a fully decarbonised energy system in 2050, it is essential to establish many new district heating systems now, with a significant expansion of these from 2025. This report stresses the urgency of immediate action, and that the redesign of energy systems requires long-term strategic energy planning. It is necessary to maintain long-term goals and translate them into actionable steps such as investment levels, new capacity targets, energy efficiency targets and others.

International audience ; The focus of this Symposium was on bifidobacteria and propionibacteria for dairy and probiotic applications.Both genera have many similarities: being phylogenetically closely grouped within the Actinobacteria, they are high G+C branch Gram-positive bacteria, and share several physiological properties, despite having different industrial applications. It was highlighted in this Symposium that, from the point of view of consumers, consumer organizations, and government agencies, clarity regarding the quality and the label correctness of these commercial probiotic products is often lacking. Some papers have demonstrated that the recovery of the incorporated probiotic organisms is often poor, sometimes below the levels established by legislative rules, especially if the bacteria used are not biologically stable in the particular food formulation. The extreme sensitivity or thermal tolerance of Bifidobacterium to spray-drying and storage temperature has proven to be a major impediment to the effective application of these bacteria in functional foods. Other papers concluded that more attention should be directed to the identity, safety and functionality of these strains. This is also of interest to both industry and consumers alike. For this reason, a significant number of presentations during this meeting were related to the identification of propionibacteria and bifidobacteria at species or strain level, as probiotic characteristics are strain-dependent. From a scientific, technological and regulation point of view, it is important to identify, characterize and recover strains from products correctly. Besides, since bifidobacteria and propionibacteria naturally occur in complex environments, such as food and the intestine of animals and man, their final identification, based on phenotypic patterns, have proven to be difficult, time-consuming and not conclusive. Modern tools of rapid detection of bifidobacteria and propionibacteria, and quantification and study of population growth dynamics ...

This research is centered on thermoeconomic assessment of the joint production of electricity, fresh-water, cooling and process heat for solar polygeneration plants, to create scientific knowledge basis for the development of concentrated solar power (CSP) technologies in zones with high direct irradiation conditions, and the rational and optimal use of polygeneration schemes to increase the overall system energy conversion efficiency and minimize the costs of the final products. The main objective of this dissertation is to model, evaluate, and optimize solar polygeneration plants in thermoeconomic terms, configured by a CSP parabolic trough collector field, thermal energy storage and backup system, a multi-effect distillation (MED) module, a single-effect absorption refrigeration (REF) module, and a process heat (PH) module, whose prime mover is the CSP plant, and considering that the polygeneration plants are located in an area with high solar irradiation conditions, and large demands of energy and water. The solar polygeneration plants are simulated in a transient regime, in a representative location with high irradiation conditions, such as in northern Chile. In the development of this dissertation IPSEpro, Microsoft Excel, MATLAB, EES (Engineering Equation Solver), and the ExIO module as a complement of the Microsoft Excel software were used. In order to expand thermoeconomic analysis in the assessment of solar polygeneration schemes, the methodology includes the use of two thermoeconomic methods. The first method, based on the exergy costing method, was used to assess the actual cost of each product; to conduct a sensitivity analysis of investment, fuel cost and demand, and to evaluate the effects of solar field size and the sizing of thermal energy storage. Three configurations are investigated: two polygeneration schemes and one considering stand-alone systems. Furthermore, this method was compared with the levelized cost method in terms of the costs allocation and the unit specific cost of each product. Whereas the second method, based on the symbolic exergoeconomic method, was used to analyze in depth the process of exergy cost formation, compare with stand-alone systems, and establish the best configuration in cogeneration, trigeneration and polygeneration schemes, in which twenty-one configurations are investigated: eight of cogeneration, eight of trigeneration, four polygeneration schemes, and one considering stand-alone systems. This dissertation was developed through three journal papers. This study reveals that a solar polygeneration plant is more efficient and cost-effective than stand-alone systems for a zone with high irradiation conditions and proximity to consumption centers, such as mining industries, which require continuous operation and energy supply with fundamentally constant demand. Furthermore, according to northern Chilean market, solar polygeneration configurations are competitive regarding electricity, fresh-water, cooling and heat productions. Additionally, solar polygeneration plants might increase the economic profit by selling carbon credits and credits of renewable-energy quotas based on the Kyoto Protocol and Chilean legislation, respectively. Also reveals that the thermoeconomic method is an equitable and rational cost allocation method which is suitable for applying in a solar polygeneration plant. Another result is that this method is recommended when a more precise analysis it is necessary to assess the proper costs of different products, and for assessing the benefits of a polygeneration plant, when compared to stand-alone systems. On the other hand, the levelized cost method is a simple and fast method, and a deep knowledge of thermodynamics is not required, being recommended when it is necessary to perform a first approached of the costs of each product. Another important result is that the key equipment, in which the design should be improved in solar multi-generation plants, are: solar collector, productive subsystems (MED, REF, and PH plants), evaporator, and reheater. Also, the recommended configurations for the integrated solar multi-generation plants (cogeneration, trigeneration, and polygeneration) are those, in which the MED plant replaces the condenser of the power cycle, and the refrigeration plant, as well as the process heat module are coupled to turbine extractions. Those plants were the most cost-effective configuration. The results delivered provide useful information that could serve to decision-makers to point out the actual potential offered by solar polygeneration systems, and could constitute a guide to understand these methods.

The building sector accounts for approximately 40% of primary energy use within the European Union, therefore reductions in the energy use intensity of this sector are critical in decreasing total energy usage. Given that the majority of energy used within the built environment is for space conditioning and domestic hot water preparation, prudence would suggest that decreasing primary energy used for these end purposes would have the biggest overall environmental impact. A significant portion of the energy demands in buildings throughout the year could potentially be met using solar energy technology for both heating and cooling. Additionally, improving the efficiency of current heating and cooling appliances can reduce environmental impacts during the transition from non-renewable to renewable sources of energy. However, in spite of favourable energy saving prospects, major energy efficiency improvements as well as solar heating and cooling technology are still somewhat underutilised. This is typically due to higher initial costs, and lack of knowledge of system implementation and expected performance. The central premise of this thesis is that modular thermally (i.e., sorption) driven heat pumps can be integrated into heating and cooling systems to provide energy cost savings. These sorption modules, by virtue of their design, could be integrated directly into a solar thermal collector. With the resulting sorption integrated collectors, cost-effective pre-engineered solar heating and cooling system kits can be developed. Sorption modules could also be employed to improve the efficiency of natural gas driven boilers. These modules would effectively transform standard condensing boilers into high efficiency gas-driven heat pumps that, similar to electric heat pumps, make use of air or ground-source heat. Based on the studies carried, sorption modules are promising for integration into heating and cooling systems for the built environment generating appreciable energy and cost-savings. Simulations yielded an annual solar fraction of 42% and potential cost savings of €386 per annum for a sorption integrated solar heating and cooling installation versus a state-of-the-art heating and cooling system. Additionally, a sorption integrated gas-fired condensing boiler yielded annual energy savings of up to 14.4% and corresponding annual energy cost savings of up to €196 compared to a standard condensing boiler. A further evaluation method for sorption modules, saw the use of an artificial neural network (ANN) to characterise and predict the performance of the sorption module under various operating conditions. This generic, application agnostic model, could characterise sorption module performance within a ± 8% margin of error. This study thus culminates in the proposal of an overall systematic evaluation method for sorption modules that could be employed for various applications based on the analytical, experimental and simulation methods developed.

There is no consensus among producers and agricultural practitioners as to which bedding material is the best. The choice is largely influenced by its useful properties, duration of use and high cost. Organic (straw, sawdust, wood shavings, peat, etc.), inorganic (sand) and synthetic (rubber mats; mattresses made of chopped rubber, latex, polyurethane foam lining, waterproof wax coating, etc.) materials are used for bedding. A significant part of agricultural organizations in Belarus uses winter straw. As a bedding material, it has a number of useful properties: low thermal conductivity, high moisture absorption capacity, low cost, and comfort for animals. According to the Republican standards for the technological design of new, reconstruction and technological re-equipment of livestock facilities (RNTD-1-2004), the standards for consumption of straw bedding for cows at loose housing on deep litter is 8 kg, but there are no input standards for sections with other technological solutions. The paper presents the results of studies to determine the optimal rate of straw bedding in sections with different technological solutions. Analysis of ethological reactions of animals, contamination of the skin, presence/absence of injuries on the body, temperature characteristics of the straw bedding in different seasons of the year and the economic efficiency of using different straw bedding rates has been performed. It has been determined that the optimal straw bedding rate for the general section is 4.5 kg/animal per day, for a section with a division into a feeding area and a rest area – 3.0 kg/animal per day. Application of these rates of straw bedding will enable it to be used economically without affecting the productivity and resting comfort of cows. The research results can be used in design and construction of industrial dairy complexes and storages for rough feeds.

Abstract: While climate change, increasing energy consumption, deteriorated air quality and exhaustion of natural resources represent central economic and social challenges today, the waste heat energy released into the atmosphere is a clean, fuel-free and inexpensive energy source. Seventy per cent of energy generated daily is waste heat. Even though thermoelectric and thermo-electrochemical cells are technologies used to convert waste heat into electrical energy, there does not yet exist a technology for the viable harvesting of low-grade waste heat [1]. This presentation will provide an overview of the EU-funded project 'TRANSLATE' which aims to develop a proof-of-concept nanofluidic platform technology based on the flux of ions in nanochannels (Fig. 1) [2]. The work targets innovation in versatile and sustainable energy harvesting and storage [3]. References: [1] Agathokleous, R. et al. Waste Heat Recovery in the EU industry and proposed new technologies. Energy Procedia. 2019, 161, 489-496. [2] Dietzel, M.; Hardt, S. Thermoelectricity in confined liquid electrolytes. Phys. Rev. Lett. 2016, 116, 225901. [3] https://cordis.europa.eu/project/id/964251 Additional Information: Professor Justin Holmes, Professor Steffen Hardt, Dr Satarupa Dutta, and Dr Ievgen Nedrygailov presented at the 80th International Conference of the University of Latvia. TRANSLATE is a €3.4 million EU-funded research project that aims to develop a new nanofluidic platform technology to effectively convert waste heat to electricity. This technology has the potential to improve the energy efficiency of many devices and systems, and provide a radically new zero-emission power source. The TRANSLATE project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 964251, for the action of 'The Recycling of waste heat through the Application of Nanofluidic ChannelS: Advances in the Conversion of Thermal to Electrical energy'. More information can be be found on the TRANSLATE ...

Polymorphism of organic semiconducting materials exerts critical effects on their physical properties such as optical absorption, emission and electrical conductivity, and provides an excellent platform for investigating structure-property relations. It is, however, challenging to efficiently tune the polymorphism of conjugated polymers in aggregated, semi-crystalline phases due to their conformational freedom and anisotropic nature. Here, two distinctly different semi-crystalline polymorphs (beta(1) and beta(2)) of a low-bandgap diketopyrrolopyrrole polymer are formed through controlling the solvent quality, as evidenced by spectroscopic, structural, thermal and charge transport studies. Compared to beta(1), the beta(2) polymorph exhibits a lower optical band gap, an enhanced photoluminescence, a reduced pi-stacking distance, a higher hole mobility in field-effect transistors and improved photocurrent generation in polymer solar cells. The beta(1) and beta(2) polymorphs provide insights into the control of polymer self-organization for plastic electronics and hold potential for developing programmable ink formulations for next-generation electronic devices. ; This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 747422, from the Netherlands Organisation for Scientific Research(016.Veni.192.106), from the Chinese Academy of Sciences (Grant No. XDB12020200), and from King Abdullah University of Science and Technology (KAUST). The research also received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) (Grant Agreement no. 607585, project OSNIRO), the European Research Council (ERC Grant Agreement No. 33903), and the Ministry of Education, Culture, and Science (Gravity program 024.001.035). T.M. acknowledges the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund (First TEAM/2017-3/26). The authors acknowledge Beamline 9 of the DELTA electron storage ring in Dortmund for GIWAXS measurements. The authors thank Mateusz Brzezinski for the discussion about GIWAXS analysis, and Christ Weijtens for UPS measurements.

Half-metallic ferromagnetic La0.7Sr0.3MnO3 (LSMO) represents an appealing candidate to be integrated on silicon substrates for technological devices such as sensors, data storage media, IR detectors, and so on. Here, we report high-quality epitaxial LSMO thin films obtained by an original combination of chemical solution deposition (CSD) and molecular beam epitaxy (MBE). A detailed study of the thermal, chemical, and physical compatibility between SrTiO3 (STO)/Si buffer layers and LSMO films, grown by MBE and CSD, respectively, enables a perfect integration of both materials. Importantly, we show a precise control of the coercive field of LSMO films by tuning the mosaicity of the STO/Si buffer layer. These results demonstrate the enormous potential of combining physical and chemical processes for the development of low-cost functional oxide-based devices compatible with the complementary metal oxide semiconductor technology. ; ACG acknowledges the financial support from the French Agence Nationale pour la Recherche (ANR), project Q-NOSS ANR-16-CE09-0006-01 and École Centrale de Lyon under the BQR 2016 project. The research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative–I3). This project has received funding from the EU‐H2020 research and innovation Program under grant agreement No 654360 having benefitted from the access provided by ICMAB-CSIC in Barcelona within the framework of the NFFA‐Europe Transnational Access Activity. Fruitful discussions with Pr. F. Rivadulla from USC are highly acknowledged. INL authors acknowledge the European Commission for funding the project TIPS (H2020-ICT-02-2014-1-644453). We thank P. Regreny, C. Botella, and J. B. Goure for the MBE technical assistance on the Nanolyon technological platform. ; Peer reviewed