Publications

Other papers | 2020

Experimentally verified dynamic simulation model of a NH3/H2O-absorption refrigeration system

Wernhart M, Rieberer R, Zlabinger S, Unterberger V, Gölles M. Experimentally verified dynamic simulation model of a NH3/H2O-absorption refrigeration system. in Japan Society of Refrigerating and Air Conditioning Engineers, Hrsg., 14th IIR Gustav-Lorentzen Conference on Natural Fluids, GL 2020 - Proceedings. International Institute of Refrigeration. 2020. S. 103-109. (Refrigeration Science and Technology). https://doi.org/10.18462/iir.gl.2020.1145

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The operation characteristics of thermally driven absorption refrigeration systems (ARS) are strongly dependent on their hydraulic integration. Therefore, varying operating conditions of the hydraulic supply have a great influence on the behaviour of ARS and lead to dynamic operation, which can affect the efficiency and is largely unexplored so far. To enable a simple investigation of ARS integration considering their dynamic behaviour and to develop modern, efficiency-enhancing control strategies, dynamic simulation models of ARS are developed in Modelica Code.

In this paper, a dynamic simulation model of an ARS with the working pair ammonia/water (NH3/H2O) is presented. The parameterization and the physical correlations of selected components of the simulation model are described. Afterwards, the simulation model is verified by comparing simulation results with measurement data of the NH3/H2O-ARS. Finally, the capabilities of the simulation model are demonstrated by performing a simulation-based analysis of the temperature glide of the refrigerant in the evaporator.

Other papers | 2020

Experimentally verified dynamic simulation model of a NH3/H2O-absorption refrigeration system

Wernhart MW, Rieberer R, Zlabinger S, Unterberger V, Gölles M. Experimentally verified dynamic simulation model of a NH3/H2O-absorption refrigeration system.14th IIR-Gustav Lorentzen Conference on Natural Refrigerants: GL 2020. 7 Dec 2020. Oral presentation (online).

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Other Publications | 2012

Experimentelle Entwicklung eines Pellet-Raumheizgerätes

Raab, A. Experimentelle Entwicklung eines Pellet-Raumheizgerätes, Bachelor Thesis, FH Oberösterreich, Wels, Österreich, 2012.

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Other Publications | 2013

Experimentelle und numerische Untersuchung der Wärmeleitung in Depositionsschichten

Andonov, W. Experimentelle und numerische Untersuchung der Wärmeleitung in Depositionsschichten, Diploma Thesis, Technische Universität Graz, Graz, Austria, 2013.

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Der Schwerpunkt dieser Arbeit richtet sich auf die Kondensation von Aschedämpfen und die Feinstaubablagerung in Biomasse-befeuerten Kesseln. Zu diesem Zweck wurden in einer Versuchsanlage aschebildende Substanzen verdampft und anschließend auf einer gekühlten Sonde kondensiert. Als Modellsubstanz für die Aschedämpfe der Biomasse wurde Kaliumchlorid verwendet. Das Rauchgas wurde dabei mittels Verbrennung von Erdgas durch einen Gasbrenner zur Verfügung gestellt. Es sollten Informationen darüber gewonnen werden, welche Struktur die Depositionsschicht durch Kondensation oder Feinstaubablagerung ausbildet (Porosität, Homogenität, Festigkeit, Struktur) und wie die gebildete Depositionsschicht den Wärmeübergang beeinflusst. Die Berechnung des Kondensationsmassenstromes der aschebildenden Substanz mittels eines Ähnlichkeitsansatzes zum Wärmeübergang (Lewis-Ansatz) zeigt eine gute Übereinstimmung zu den experimentellen Versuchen. Die Depositionsschicht weist eine sehr hohe Porosität (p > 0,97) auf. Das Wärmeleitmodell „k maximum“ berechnet entsprechende Werte für die Wärmeleitfähigkeit der Depositionsschicht. Die Struktur der gebildeten Depositionsschicht ist von der Oberflächentemperatur der Sonde abhängig. Bei niedriger Sondentemperatur (T1 = 300 °C) bildet sich das Gefüge der Kondensationsschicht aus Kaliumchlorid als würfelförmige Kristalle aus, die „turmartig“ aufeinander herauswachsen. Diese Schicht zeichnet sich durch eine höhere Stabilität aus. Bei höherer Sondentemperatur (T2 = 500 °C) ist das Gefüge aus kleineren nadeligen und tröpfchenförmigen Kristallen aufgebaut, welche „baumartig“ herauswachsen. Wenn man die Kondensationsschicht am Depositionsring betrachtet wird ersichtlich, dass sich die Verteilung der Depositionsmenge in Abhängigkeit von der Depositionsmasse sehr unterschiedlich ausbildet. Bei geringer Depositionsmenge (m < 0,01 [g]) ist die Verteilung gleichmäßig um den Ring verteilt, bei höherer Depositionsmenge (m>0,01 [g]) befindet sich der Hauptteil der Depositionsmasse hauptsächlich auf der rauchgaszugewandten Seite der Sonde. Obwohl die Berechnung der Kondensationsmassenströme mit Hilfe des Ähnlichkeitsansatzes eine gute Übereinstimmung zeigt, sind die berechneten Werte stets etwas höher als die gemessenen Ergebnisse. Es wird vermutet, dass die Ursache in der hohen Instabilität der Depositionsschicht liegt, wodurch Erosionsvorgänge durch die vom Rauchgas erzeugten Schubspannungen die Depositionsschichtdicke reduzieren. Die Wärmeleitfähigkeit der Depositionsschicht ist aufgrund der hohen Porosität (hoher Anteil des fluiden Rauchgasanteils mit geringer Wärmeleitfähigkeit, kleiner Anteil des stark wärmeleitenden festen Kaliumchlorids) sehr niedrig, aber trotzdem deutlich höher als die Wärmeleitfähigkeit des Rauchgases. Sie liegt in der Größenordnung von k = 0,1-0,2 [W/mK]. Schon geringe Depositionsschichtmassen bewirken eine starke Verringerung des Wärmeüberganges und einen damit verbundenen hohen Temperaturgradienten in der Depositionsschicht. In dieser Arbeit wurden die für den Aufbau der Depositionsschicht maßgebenden Einflussfaktoren untersucht. Diese sind die Rauchgasgeschwindigkeit, die Salzfreisetzung, die Kondensationsdauer und die Oberflächentemperatur. Die Salzfreisetzung ist maßgebend für die Kondensationsmasse. Eine Verdoppelung der Salzfreisetzungsrate zeigte im untersuchten Wandbereich eine Verdoppelung der Kondensationsrate. Eine Verdoppelung der Rauchgasgeschwindigkeit führte zu einer geringen Abnahme der Kondensationsmasse bei gleichbleibenden Betriebsparametern, welches höchstwahrscheinlich durch Erosionsvorgänge bedingt ist. Die Sondenoberflächentemperatur zeigte im untersuchten Temperaturbereich von 300°C-500°C bei geringen Kondensationsmassen keinen Einfluss auf die Kondensationsrate. Bei größeren Depositionsschichten hatte die höhere Temperatur eine Verringerung der Kondensationsrate zur Folge.  

Other Publications | 2012

Experimentelle Untersuchungen an einem Gasflammenreaktor zur Charakterisierung der Gasphasenverbrennung in Biomasserostfeuerungen

Kamnig, H. Experimentelle Untersuchungen an einem Gasflammenreaktor zur Charakterisierung der Gasphasenverbrennung in Biomasserostfeuerungen, Master Thesis, Technische Universität Graz, Graz, Austria, 2012.

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 Ziel der Diplomarbeit war die Bereitstellung von Messdaten für die Entwicklung eines Gasphasenverbrennungsmodells, welches den niedrig-turbulenten Strömungsbereich und den Einfluss der Strähnenbildung auf den Mischungsfortschritt von partiell vorgemischten Flammen über dem Brennstoffbett von Biomasse-Rostfeuerungen abbildet. Diese Arbeit beschäftigt sich mit der Konstruktion und dem Bau eines Flammenreaktors und einer Gasverteilungsstation zur Erzeugung von kalten Strömungen ohne chemische Reaktion und partiell vorgemischten Flammen mit chemischer Reaktion, welche die niedrig-turbulenten Strömungen über dem Brennstoffbett in Biomasse Rostfeuerungen genähert abbilden sollen. Zur Untersuchung der auftretenden Gas- und Luftsträhnen und deren Einfluss auf den Mischungsfortschritt über dem Biomasse Brennstoffbett, wurde für den Versuchsaufbau ein Düsenkonzept zur Gas- und Luftverteilung verwendet. In kalten Strömungen sollen die Mischungseffekte niedrig turbulenter Strömungen sowie der Mischungsfortschritt aufgrund der Strähnenbildung, entkoppelt von chemischen Reaktionen, untersucht werden. In den Flammen gilt es zusätzliche Einflüsse, wie die Expansion des Gases und die chemischen Reaktionen, zu untersuchen. Im Rahmen dieser Diplomarbeit wurden im Flammenreaktor extraktive FTIR- und RGA-Spezieskonzentrationsmessung in kalten Strömungen und in Flammen sowie optische LDA-Gasgeschwindigkeitsmessungen in kalten Strömungen durchgeführt. Für die finalen Messungen wurden nur Gaskonzentrationsmessungen mittels FTIR und RGA durchgeführt und diskutiert, da die LDA-Messeinheit nicht mehr zur Verfügung stand. Die Messergebnisse in kalten Strömungen mit einem CO2/N2-Gasgemisch und einem Luftstrom, liefern rotationssymmetrische CO2- und O2-Konzentrationsprofile. Die Messergebnisse zeigen, dass der Mischungsfortschritt entlang der Strömungsrichtung weitgehend entkoppelt ist von den Gaseintrittsgeschwindigkeiten vGas=2 m/s bis vGas=4. Die Konzentrationsergebnisse der Messungen mit den CO2/N2/Luft-Gemischen konnten mittels einer Stoffbilanz erfolgreich geprüft werden. Die Messergebnisse in kalten Strömungen entsprechen bezüglich der Gasgeschwindigkeiten zwischen 2 und 4 m/s sowie mit den Reynoldszahlen zwischen 800 und 9000 den laminaren bis niedrig-turbulenten Strömungsbedingungen von partiell vorgemischten Flammen über dem Brennstoffbett in Biomasse Rostfeuerungen. Die Messergebnisse der Flammenmessungen mit einem CH4/Luft-Gasgemisch und einem Luftstrom, liefern mit RGA- und FTIR-Messungen nicht reproduzierbare Ergebnisse innerhalb der Flamme und weisen große Gasspeziesasymmetrien in der Flamme auf. Die Messergebnisse zeigen, dass die Gaseintrittsgeschwindigkeiten vGas=2 m/s bis vGas=4 mit dem Verbrennungsfortschritt von CH4 in Strömungsrichtung gekoppelt sind. Die Konzentrationsergebnisse der Flammenmessungen mit einem CH4/Luft-Gemisch konnten mit den vorhandenen Messwerten nicht erfolgreich mittels einer Stoffbilanz geprüft werden. Zusammengefasst liefen die Konzentrationsmessungen in kalter Strömung sehr gute Messergebnisse in Hinblick auf Strömungsstabilität, rotationssymmetrische Strömungsausbildung und Messgenauigkeit. Für Messungen in kalten Strömungen sind die Messverfahren mittels FTIR und RGA zur Konzentrationsmessung und das LDA-Messverfahren zur Gasgeschwindigkeitsmessung zu empfehlen. Die RGA- und FTIR-Konzentrationsmessungen in den Flammen liefern keine zufriedenstellenden Messergebnisse aufgrund von Flammenasymmetrien sowie dem Einfluss der extraktiven Probenahme mittels einer Probenahmelanze. Für Flammenmessungen im Reaktor sind berührungsfreie, optische Messverfahren mit einer hohen Messauflösung zu empfehlen. Durchlichtverfahren benötigen zwei optische Zugänge zum Messraum. Für die Anwendung von Durchlichtverfahren müsste der Flammenreaktor von einem auf zwei optische Zugänge umgebaut werden.  

Conference presentations and posters | 2013

Experimentelle Untersuchungen der Hochtemperaturkorrosion von 13CrMo4-5 in einem mit Biomasse befeuerten Fallrohr und ihre Übertragbarkeit auf Großfeuerungsanlagen

Gruber T. Experimentelle Untersuchungen der Hochtemperaturkorrosion von 13CrMo4-5 in einem mit Biomasse befeuerten Fallrohr und ihre Übertragbarkeit auf Großfeuerungsanlagen, VDI-Fachkonferenz: Feuerungen und Kessel - Beläge und Korrosion - in Großfeuerungsanlagen 2013, 24th-25th of June 2013, Düsseldorf, Germany.

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Peer reviewed papers | 2018

Experiments and modelling of NOx precursors release (NH3 and HCN) in fixed-bed biomass combustion conditions

Anca-Couce A, Sommersacher P, Evic N, Mehrabian R, Scharler R. Experiments and modelling of NOx precursors release (NH3 and HCN) in fixed-bed biomass combustion conditions. Fuel. 2018, 222: 529-537.

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There is a need to reduce NOx emissions, which can only be achieved through a detailed understanding of the mechanisms for their formation and reduction. In this work the release of the NOx precursors, NH3 and HCN, for different fuels is experimentally analysed and modelled in typical fixed-bed combustion conditions. It is shown that NH3 and HCN are released during the main devolatilization phase and the NH3/HCN ratio increases for fuels with a higher nitrogen content. A simplified two-steps model for their release is presented. The model can predict with a reasonable accuracy the release for fuels with a low nitrogen content, however deviations are present for fuels with a high nitrogen content, which probably arise due to a reduction of NH3 and HCN taking place already in the bed.

Peer reviewed papers | 2022

Expert survey and classification of tools for modeling and simulating hybrid energy networks

Widl E, Cronbach D, Sorknæs P, Fitó J, Muschick D, Repetto M, Ramousse J, Ianakiev A. Expert survey and classification of tools for modeling and simulating hybrid energy networks. Sustainable Energy, Grids and Networks. December 2022.32:100913.

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Sector coupling is expected to play a key role in the decarbonization of the energy system by enabling the integration of decentralized renewable energy sources and unlocking hitherto unused synergies between generation, storage and consumption. Within this context, a transition towards hybrid energy networks (HENs), which couple power, heating/cooling and gas grids, is a necessary requirement to implement sector coupling on a large scale. However, this transition poses practical challenges, because the traditional domain-specific approaches struggle to cover all aspects of HENs. Methods and tools for conceptualization, system planning and design as well as system operation support exist for all involved domains, but their adaption or extension beyond the domain they were originally intended for is still a matter of research and development. Therefore, this work presents innovative tools for modeling and simulating HENs. A categorization of these tools is performed based on a clustering of their most relevant features. It is shown that this categorization has a strong correlation with the results of an independently carried out expert review of potential application areas. This good agreement is a strong indicator that the proposed classification categories can successfully capture and characterize the most important features of tools for HENs. Furthermore, it allows to provide a guideline for early adopters to understand which tools and methods best fit the requirements of their specific applications.

Other Publications | 2023

Exploring microbiomes in environmental biotechnological processes

Bauer L, Konegger H, Neubauer M, Ludiwg K, Drosg B. Exploring microbiomes in environmental biotechnological processes. BEST Center Day. 28 June 2023

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Many processes in environmental biotechnology are working due to the presence of a mix of microbes, with each group playing a specific role, like being responsible for one step of a multistage conversion process. Even in industrial fermentations which have the purpose of producing biomass of one specific microorganism, an accompanying flora of other microbes is almost always present.

Other Publications | 2013

Extending the range of feedstock of the dual fluidized bed gasification process towards residues and waste

Wilk, V. Extending the range of feedstock of the dual fluidized bed gasification process towards residues and waste, Ph.D. Thesis, Vienna University of Technology, Vienna, Austria, 2013.

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Peer reviewed papers | 2023

Extension of the layer particle model for volumetric conversion reactions during char gasification

Steiner T, Schulze R, Scharler R, Anca-Couce A. Extension of the layer particle model for volumetric conversion reactions during char gasification. Combustion and Flame. 2023:256,112940.

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The so-called “layer model” or “interface-based model” is a simplified single particle model, originally developed for shorter computation time during computational fluid dynamics (CFD) simulations. A reactive biomass particle is assumed to consist of successive layers, in which drying, pyrolysis and char conversion occur sequentially. The interfaces between these layers are the reaction fronts. The model has already been validated for drying, pyrolysis and char oxidation. Layer models in the literature have commonly employed surface reactions at the reaction front to describe char conversion. In this work, the suitability of this surface reaction concept is assessed when gasifying biochar. It is shown that a particular layer model, already available, which originally employed surface reactions, was unable to adequately describe the mass loss during gasification of a biochar. In order to overcome this incapability, the model was extended to consider volumetric reactions in the char layer. The influence of intraparticle diffusion was considered through an effectiveness factor. The model is easily adaptable for different gas-solid kinetic rate laws, while still allowing for comparably fast solutions of the model equations. The extended model was validated using theoretical calculations and experimental measurements from literature. It was demonstrated that intraparticle diffusion can significantly slow down the biochar gasification process. A general guideline for when to employ volumetric reactions, rather than surface reactions, and when to consider intraparticle diffusion is provided based on the Thiele modulus as the criterion.

Reports | 2019

Factsheet Staubemissionen

Schwarz M, Strasser C. Factsheet Staubemissionen. 2019

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Zum Erreichen der Ziele der österreichischen Klimastrategie leisten Biomassefeuerungen einen entscheidenden Beitrag. Um dabei die Luftgüte nicht außer Acht zu lassen, wird in diesem Factsheet der aktuelle und zukünftige Status (bis 2050) von Staubemissionen in Österreich basierend auf Literaturdaten und eigenen Messungen dargelegt, und der aktuelle Kenntnisstand zu Emissionen aus Biomasse-Kleinfeuerungen zusammengefasst.

Peer reviewed papers | 2020

Fate of Phosphorus in Fluidized Bed Cocombustion of Chicken Litter with Wheat Straw and Bark Residues

Häggström G, Fürsatz K, Kuba M, Skoglund N, Öhman M. Fate of Phosphorus in Fluidized Bed Cocombustion of Chicken Litter with Wheat Straw and Bark Residues. Energy and Fuels. 2020.34:1822-1829

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This study aims to determine the fate of P during fluidized bed co-combustion of chicken litter (CL) with K-rich fuels [e.g., wheat straw (WS)] and Ca-rich fuels (bark). The effect of fuel blending on phosphate speciation in ash was investigated. This was performed by chemical characterization of ash fractions to determine which phosphate compounds had formed and identify plausible ash transformation reactions for P. The ash fractions were produced in combustion experiments using CL and fuel blends with 30% CL and WS or bark (B) at 790–810 °C in a 5 kW laboratory-scale bubbling fluidized bed. Potassium feldspar was used as the bed material. Bed ash particles, cyclone ash, and particulate matter (PM) were collected and subjected to chemical analysis with scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) and X-ray diffraction. P was detected in coarse ash fractions only, that is, bed ash, cyclone ash, and coarse PM fraction (>1 μm); no P could be detected in the fine PM fraction (<1 μm). SEM–EDS analysis showed that P was mainly present in K–Ca–P-rich areas for pure CL as well as in the ashes from the fuel blends of CL with WS or B. In the WS blend, P was found together with Si in these areas. The crystalline compound containing P was hydroxyapatite in all cases as well as whitlockite in the cases of pure CL and WS blend, of which the latter compound has been previously identified as a promising plant nutrient. The ash fractions from CL and bark blend only contained P in hydroxyapatite. Co-combustion of CL together with WS appears to be promising for P recovery, and ashes with this composition could be further studied in plant growth experiments

Conference presentations and posters | 2017

Fault Detective - Automatic Fault Detection for Solar Thermal Systems based on Artificial Intelligence

Feierl L, Bolognesi T, Unterberger V, Gaetani M, Gerardts B, Rossi C. Fault Detective - Automatic Fault Detection for Solar Thermal Systems based on Artificial Intelligence. EuroSun 2022. 25 - 29 September 2022. Kassel, Germany. Oral Presentation.

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Peer reviewed papers | 2023

Fault detective: Automatic fault-detection for solar thermal systems based on artificial intelligence

Feierl L, Unterberger V, Rossi C, Gerardts B, Gaetani M. Fault detective: Automatic fault-detection for solar thermal systems based on artificial intelligence. Solar Energy Advances 2023;3:100033. https://doi.org/10.1016/j.seja.2023.100033.

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Fault-Detection (FD) is essential to ensure the performance of solar thermal systems. However, manually analyzing the system can be time-consuming, error-prone, and requires extensive domain knowledge. On the other hand, existing FD algorithms are often too complicated to set up, limited to specific system layouts, or have only limited fault coverage. Hence, a new FD algorithm called Fault-Detective is presented in this paper, which is purely data-driven and can be applied to a wide range of system layouts with minimal configuration effort. It automatically identifies correlated sensors and models their behavior using Random-Forest-Regression. Faults are then detected by comparing predicted and measured values.

The algorithm is tested using data from three large-scale solar thermal systems to evaluate its applicability and performance. The results are compared to manual fault detection performed by a domain expert. The evaluation shows that Fault-Detective can successfully identify correlated sensors and model their behavior well, resulting in coefficient-of-determination scores between R²=0.91 and R²=1.00. In addition, all faults detected by the domain experts were correctly spotted by Fault-Detective. The algorithm even identified some faults that the experts missed. However, the use of Fault-Detective is limited by the low precision score of 30% when monitoring temperature sensors. The reason for this is a high number of false alarms raised due to anomalies (e.g., consecutive days with bad weather) instead of faults. Nevertheless, the algorithm shows promising results for monitoring the thermal power of the systems, with an average precision score of 91%.

Conference presentations and posters | 2022

FAULT DETECTIVE: FAULT DETECTION FOR SOLAR THERMAL SYSTEMS

Feierl L, Bolognesi T, Unterberger V, Geatani M, Gerardts B. FAULT DETECTIVE: FAULT DETECTION FOR SOLAR THERMAL SYSTEMS. ISEC 2022. 05 - 07. April 2022, Graz. Poster presentation.

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Other Publications | 2014

Fermentation of biomass from micro algae

Gruber M, Zohar E, Jerney J, Bochmann G, Obbard JP, Schagerl M, Fuchs W, Drosg B. Fermentation of biomass from micro algae, 4th Central European Biomass Conference 2014, 15th-18th of January 2014, Graz, Austria.

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Other Publications | 2023

First results from a novel temperature swing adsorption plant for clean synthesis gas

Egger A, Binder M, Weber G, Fürsatz K. First results from a novel temperature swing adsorption plant for clean synthesis gas. BEST Center Day. 28 June 2023

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Other Publications | 2009

First test runs and tar analyses of a low temperature pyrolysis

Wolfesberger, U. First test runs and tar analyses of a low temperature pyrolysis, Master Thesis, Vienna University of Technology, Vienna, Austria, 2009.

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The global warming, the increasing CO2 emission, the combustion and dependency on fossil fuels, as well as the high-energy prices have resulted in an increasing demand in renewable energy sources. Biomass, as a renewable energy source, has the potential to contribute to the future energy mix in many countries. In this thesis the so-called low temperature or slow pyrolysis is chosen to convert biomass into energy rich products. Pyrolysis is a process to convert biomass directly into solid, liquid and gaseous products by thermal decomposition in absence of oxygen. The goal of the pilot plant Dürnrohr is to generate a combustible gas to substitute fossil fuels in the thermal power plant Dürnrohr. The complete process consists of individual steps. First of all the biomass is pyrolysed and pyrolysis gas and pyrolysis char are produced. The obtained pyrolysis gas is combusted in a fluidized bed combustion chamber implemented as afterburner. The following step is fluidized bed combustion of
the intermediate-stored pyrolysis char. Due to the use of different biomasses and adjustment of the individual steps, the process should be optimized for the application for the power plant Dürnrohr. One major point of the production of the pyrolysis gas is the amount of tar. The tar amount was analyzed during pyrolysis operation to find out how much tar is produced at which process settings with a main focus on the temperature. The gravimetric
analysis included gravimetric tar, dust, entrained char, water content and ph-value, as well as the GC/MS tars of the pyrolysis gas. All these data was sampled, analyzed and evaluated as well as discussed.

Peer reviewed papers | 2013

Fischer Tropsch Synthesis to Biofuels (BtL Process)

Rauch R, Kiennemann A, Sauciuc A. Fischer Tropsch Synthesis to Biofuels (BtL Process). The role of catalysis for the sustainable production of Bio-fuels and Bio-chemicals. ISBN 978-0-444-56330-9 2013:397-443.

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Fischer-Tropsch (FT) synthesis is one option to produce liquid transportation fuels from carbon-containing feedstocks. In the past, FT synthesis was used mainly to convert coal or natural gas to diesel and gasoline. In the last decade, much R&D effort has been made to use this technology to convert biomass to a high-quality transportation fuel. In this chapter, the technology for BtL (conversion of biomass to liquid transportation fuels over FT synthesis) is described, from synthesis gas production including requirements on the gas quality to a detailed description of the FT synthesis itself. The main focus of this chapter is to give an overview of the types of catalysts, also including their preparation, reduction, and aging; the types of FT reactors; and also the reaction conditions including kinetic laws and mechanistic proposals.

Other Publications | 2023

Fischer-Tropsch pilot plant

Hochgerner S, Arlt S, Köffler T, Weber G, Kuba M, Rauch R, Hofbauer H. Fischer-Tropsch plant. BEST Center Day. 28 June 2023

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This work presents the first results of a newly commissioned biomass-to-liquid Fischer-Tropsch (FT) pilot plant. A 1 MWth dualfluidized bed (DFB) steam gasifier, a 55 Nm3/h 4-step gas cleaning plant and a 250 kW slurry bubble column FT synthesis reactor (SBCR) form the full process chain.

Reports | 2019

Fischer-Tropsch products from biomass-derived syngas and renewable hydrogen

Gruber H, Groß P, Rauch R, Reichhold A, Zweiler R, Aichernig C, Müller S, Ataimisch N, Hofbauer H. Fischer-Tropsch products from biomass-derived syngas and renewable hydrogen. 2019.

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Global climate change will make it necessary to transform transportation and mobility away from what we know now towards a sustainable, flexible, and dynamic sector. A severe reduction of fossil-based CO2 emissions in all energy-consuming sectors will be necessary to keep global warming below 2 °C above preindustrial levels. Thus, long-distance transportation will have to increase the share of renewable fuel consumed until alternative powertrains are ready to step in. Additionally, it is predicted that the share of renewables in the power generation sector grows worldwide. Thus, the need to store the excess electricity produced by fluctuating renewable sources is going to grow alike. The “Winddiesel” technology enables the integrative use of excess electricity combined with biomass-based fuel production. Surplus electricity can be converted to H2 via electrolysis in a first step. The fluctuating H2 source is combined with biomass-derived CO-rich syngas from gasification of lignocellulosic feedstock. Fischer-Tropsch synthesis converts the syngas to renewable hydrocarbons. This research article summarizes the experiments performed and presents new insights regarding the effects of load changes on the Fischer-Tropsch synthesis. Long-term campaigns were carried out, and performance-indicating parameters such as per-pass CO conversion, product distribution, and productivity were evaluated. The experiments showed that integrating renewable H2 into a biomass-to-liquid Fischer-Tropsch concept could increase the productivity while product distribution remains almost the same. Furthermore, the economic assessment performed indicates good preconditions towards commercialization of the proposed system.

Peer reviewed papers | 2021

Fischer-Tropsch products from biomass-derived syngas and renewable hydrogen

Gruber H, Groß P, Rauch R, Reichhold A, Zweiler R, Aichernig C, Müller S, Ataimisch N, Hofbauer H. Fischer-Tropsch products from biomass-derived syngas and renewable hydrogen. Biomass Conversion and Biorefinery. 2021.11(6):2281-2292

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Global climate change will make it necessary to transform transportation and mobility away from what we know now towards a sustainable, flexible, and dynamic sector. A severe reduction of fossil-based CO2 emissions in all energy-consuming sectors will be necessary to keep global warming below 2 °C above preindustrial levels. Thus, long-distance transportation will have to increase the share of renewable fuel consumed until alternative powertrains are ready to step in. Additionally, it is predicted that the share of renewables in the power generation sector grows worldwide. Thus, the need to store the excess electricity produced by fluctuating renewable sources is going to grow alike. The “Winddiesel” technology enables the integrative use of excess electricity combined with biomass-based fuel production. Surplus electricity can be converted to H2 via electrolysis in a first step. The fluctuating H2 source is combined with biomass-derived CO-rich syngas from gasification of lignocellulosic feedstock. Fischer-Tropsch synthesis converts the syngas to renewable hydrocarbons. This research article summarizes the experiments performed and presents new insights regarding the effects of load changes on the Fischer-Tropsch synthesis. Long-term campaigns were carried out, and performance-indicating parameters such as per-pass CO conversion, product distribution, and productivity were evaluated. The experiments showed that integrating renewable H2 into a biomass-to-liquid Fischer-Tropsch concept could increase the productivity while product distribution remains almost the same. Furthermore, the economic assessment performed indicates good preconditions towards commercialization of the proposed system.

Other Publications | 2023

FlowBattMonitor - Modellgestützte Überwachung von erneuerbaren Flow Batterien (Poster)

Nigitz T, Spirk S, Poms U, Wickenhauser D. FlowBattMonitor - Modellgestützte Überwachung von erneuerbaren Flow Batterien. Poster. 2023.

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Conference presentations and posters | 2021

Flue gas recirculation during poultry litter combustion in a fixed bed lab-scale batch reactor

Katsaros G, Sommersacher P, Retschitzegger S, Kienzl N, Pandey DS. Flue gas recirculation during poultry litter combustion in a fixed bed lab-scale batch reactor. 29th European Biomass Conference and Exhibition, EUBCE 2021, 26-29 April 2021. 2021

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This study focuses on the combustion behaviour of poultry litter which was experimentally studied in a fixed bed lab-scale reactor. The combustion experiments not only provided useful insights pertaining to the thermal decomposition of poultry litter over time, release of main gaseous compounds and nitrogen (N) species, but also the release of elements found initially in the ash composition. The main gaseous species were released during the devolatilisation phase, whereas Ammonia (NH3) was found to be the most abundant compound of N-gaseous species (45%) followed by nitrogen oxide (NO) with a fraction of ~10%. Alkali metals showed moderate release rates, whilst Chlorine (Cl) was observed to have the highest one (90%) of the ash forming elements, depicting the high volatility of the specific compound.

Conference presentations and posters | 2015

Forecasting the Pellet Boiler Stock in Austria until 2030 and Assessing the Potential to Reduce GHG Emissions and Substitute Fossil Fuels

Karner K, Schmid E, Strasser C, Kristöfel C, Enigl M. Forecasting the Pellet Boiler Stock in Austria until 2030 and Assessing the Potential to Reduce GHG Emissions and Substitute Fossil Fuels, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (visual presentation)

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Conference presentations and posters | 2012

Frauen‐ und Familienförderung beginnt bei Männern – Systematisches Karenzmanagement für Mütter, Väter und das Unternehmen

Haslinger W. Frauen‐ und Familienförderung beginnt bei Männern – Systematisches Karenzmanagement für Mütter, Väter und das Unternehmen, Expertenforum K3 "Karenzmanagement macht Karriere" 2012, 9th of May 2012, Linz, Austria.

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Conference presentations and posters | 2012

Fuel indexes –a novel method for the evaluation of relevant combustion properties of new biomass fuels

Sommersacher P, Brunner T, Obernberger I. Fuel indexes –a novel method for the evaluation of relevant combustion properties of new biomass fuels, Conference Impacts of Fuel Quality on Power Production and Environment 2012, 23th-27th of September 2012, Puchberg, Austria.

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The increasing demand for biomass fuels leads to the introduction of new biomass fuels into the market. These new biomass fuels (e.g., wastes and residues from agriculture and the food industry, short rotation coppices, and energy crops) are usually not well-defined regarding their combustion behavior. Therefore, fuel characterization methods with a special focus on combustion-related problems (gaseous NOx, HCl, and SOx emissions, ash-melting behavior, and PM emissions) have to be developed. For this purpose, fuel indexes are an interesting option. Fuel indexes are derived from chemical fuel analyses and are checked and evaluated regarding their applicability by measurements performed at lab- and real-scale combustion plants for a large variety of fuels. They provide the possibilities for a pre-evaluation of combustion-relevant problems that may arise from the use of a new biomass fuel. A possible relation to describe the corrosion risk is, for instance, the molar 2S/Cl ratio. The N content in the fuel is an indicator for NOx emissions, and the sum of the concentrations of K, Na, Zn, and Pb in the fuel can give a prediction of the aerosol emissions, whereas the molar (K + Na)/[x(2S + Cl)] ratio provides a first indication regarding the potential for gaseous HCl and SOx emissions. The molar Si/K ratio can supply information about the K release from the fuel to the gas phase. The molar Si/(Ca + Mg) ratio can give indications regarding the ash-melting temperatures for P-poor fuels. For P-rich fuels, the (Si + P + K)/(Ca + Mg) ratio can be used for the same purpose. The fuel indexes mentioned can provide a first pre-evaluation of combustion-relevant properties of biomass fuels. Therefore, time-consuming and expensive combustion tests can partly be saved. The indexes mentioned are especially developed for grate combustion plants, because interactions of the bed material possible in fluidized-bed combustion systems are not considered.

Other Publications | 2023

Further development of gas-fermentation towards syngas utilization and electro-fermentation

Ludwig K, Hiebl C, Marzynski M, Deutsch M, Poms U, Schulze K, Neubauer M, Knoll L, Rachbauer L, Gölles M, Fuchs W, Drosg B. Further development of gas-fermentation towards syngas utilization and electro-fermentation. BEST center day. 28 June 2023.

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Gas-fermentation is the conversion of gaseous feedstocks (e.g. CO2-rich off gases, CO, H2) into
valuable products such as organic acids and alcohols by microorganisms such as clostridia.
By supplying electrical energy (an alternative source of reducing/oxidizing energy), the fermentation
environment can be further optimized, resulting in products with higher purity, a broader product
spectrum and higher cell densities.

Other papers | 2019

Ganzheitliche Planung dezentraler Energiekonzepte durch mathematische Optimierung

Liedtke P, Stadler M, Zellinger M, Hengl F. Ganzheitliche Planung dezentraler Energiekonzepte durch mathematische Optimierung. e-nova Konferenz 2019.

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Kernthema dieses Beitrags ist die ganzheitliche Konzeption von Mikronetze, die sich auf die Reduzierung von Kosten und CO2-Emissionen konzentriert. Mikronetze, oder auch Microgrids, ermöglichen die koordinierte Energieerzeugung von dezentralen Energieressourcen, die Speicherungen der produzierten Energie und ein Lastmanagement zum Ausgleich von Wärme-, Kälte- und Elektrizitätsdienstleistungen. Mikronetze können vom breiteren Versorgungsnetz getrennt werden, können diverse Dienstleistungen erbringen und/oder selbst Energie erzeugen sowie in Überschusszeiten speichern und bei Bedarf wieder Kosten- oder Stabilitäts-orientiert freigeben.
Die mathematische Optimierung dient als unvoreingenommene Alternative für eine gesamtheitliche Planung von dezentralen Energietechnologien. Dieses Kriterium wird bei einer Kosten- oder CO2-Reduktion vor allem dann essentiell, wenn vielfältigen Kombinationen von Technologien und Kapazitäten möglich sind. Modernste Ansätze betrachten jedoch einen quasistatischen Aufbau unter Verwendung linearisierte Modelle und Mixed Integer Linear Optimization (MILP), wobei dynamische Effekte vernachlässigt werden. Unter Berücksichtigung von Lasten, geografischen, ökonomisch-ökologischen und tariflichen Daten sind mathematische Optimierungsalgorithmen in der Lage, verschiedene Anwendungsfälle zu beurteilen, wobei Effekte wie Vorwärmung, Sollwertänderungen oder kurzfristige Sonnenschwankungen unberücksichtigt bleiben. Dies bedeutet, dass die in quasistatischen Ansätzen verwendete Wärme- und Strombilanzen ungenau sein können (eventuell können physikalische Randbedingungen sogar verletzt werden, was zu suboptimalen Ergebnissen bei der Planung führen würde).
Die Notwendigkeit besteht quasistatische Optimierung mit einer weiteren Modellierungsart zu vergleichen und die Auswirkungen auf traditionelle quasistatische Ansätze, wie sie in DER-CAM oder ReOpt eingesetzt werden, aufzudecken. Um Abweichungen - bestehend aus dynamischen oder sogar Rebound Effekten - zu erkennen, werden mit TRNSYS Gebäude- und Anlagensimulationen für eine geplante Siedlungsanlage erstellt und ein Energiekonzept mit dem mathematischen Optimierungsprogramm OptEnGrid berechnet. Der Ansatz wird für vier Doppelhäuser und ein Mehrfamilienhaus getestet. Die Gebäude werden in TRNSYS simuliert und bieten thermische Lastdaten für den Referenzfall. Auch die Stromerzeugung mit PV-Modellen und der elektrische Verbrauch mit synthetischen Lastprofilen sind sowohl in der Optimierung als auch in der Simulation beteiligt. In der elektrischen Stromerzeugung zeigt die mathematische Optimierung bereits eine Abweichung von mehr als 5% auf Jahresbasis zur TRNSYS-Simulation. Ergebnisse im thermischen Energiebereich folgen nach weiterer Auswertung.

Conference presentations and posters | 2010

Gas Cleaning and Treatment of product gas of a dual fluidised bed gasifier for CHP and synthesis applications

Rauch R. Gas Cleaning and Treatment of product gas of a dual fluidised bed gasifier for CHP and synthesis applications, SNG 2010, 30th of June-1st of July 2010, Concepcion, Chile.

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Other Publications | 2012

Gasaufbereitung für die Fischer-Tropsch-Synthese

Pölzl, P. Gasaufbereitung für die Fischer-Tropsch-Synthese, Master Thesis, Technische Universität Wien, Vienna, Austria, 2012.

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Other Publications | 2021

Gasification - a key technology in the energy transition and for the circular economy

Martini S. Gasification - a key technology in the energy transition and for the circular economy. IEA Bioenergy Task33 Meeting. December 2021.

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Conference presentations and posters | 2010

Gasification of residues and waste wood in a dual fluidized bed steam gasifier

Wilk V, Kitzler H, Hofbauer H. Gasification of residues and waste wood in a dual fluidized bed steam gasifier, ICPS 2010, 7th-9th of September 2010, Leipzig, Germany.

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Because of the limited resources of fossil fuels the efficient use of renewable energy is gaining importance. Renewable energy from biomass reduces CO2 emissions, which is a necessity to protect the global climate. In the dual fluidised bed steam gasifier wood chips are converted to heat, power and other products very successfully. This work presents alternative feedstocks for this process: biomass wastes, such as waste wood, bark and reed. Waste wood and bark have been gasified successfully and first results of these experiments in the pilot plant are presented in this paper. It has been assessed that reed is also an interesting feedstock suitable for the use in fluidised bed gasifiers.

Other Publications | 2021

Gemeinsam richtig heizen - Video

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Conference presentations and posters | 2019

GHG emission reduction costs of various technologies in the heating and mobility sectors

Strasser C, Schwarz M, Sturmlechner R, GHG emission reduction costs of various technologies in the heating and mobility sectors. 27th European Biomass Conference & Exhibition (Poster). May 2019.

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Other papers | 2012

Global effects of national biomass production and consumption: Austria's embodied HANPP related to agricultural biomass in the year 2000

Haberl H, Kastner T, Schaffartzik A, Ludwiczek N, Erb K-. Global effects of national biomass production and consumption: Austria's embodied HANPP related to agricultural biomass in the year 2000. Ecol Econ. 2012;84:66-73.

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Global trade of biomass-related products is growing exponentially, resulting in increasing 'teleconnections' between producing and consuming regions. Sustainable management of the earth's lands requires indicators to monitor these connections across regions and scales. The 'embodied human appropriation of NPP' (eHANPP) allows one to consistently attribute the HANPP resulting from production chains to consumers. HANPP is the sum of land-use induced NPP changes and biomass harvest. We present the first national-level assessment of embodied HANPP related to agriculture based on a calculation using bilateral trade matrices. The dataset allows (1) the tracing of the biomass-based products consumed in Austria in the year 2000 to their countries of origin and quantifying the HANPP caused in production, and (2) the assigning of the national-level HANPP on Austria's territory to the consumers of the products on the national level. The dataset is constructed along a consistent system boundary between society and ecosystems and can be used to assess Austria's physical trade balance in terms of eHANPP. Austria's eHANPP-trade balance is slightly negative (imports are larger than exports); import and export flows are large in relation to national HANPP. Our findings show how the eHANPP approach can be used for quantifying and mapping the teleconnections related to a nation's biomass metabolism. © 2012 Elsevier B.V.

Peer reviewed papers | 2022

Glycogen, poly(3-hydroxybutyrate) and pigment accumulation in three Synechocystis strains when exposed to a stepwise increasing salt stress

Meixner K, Daffert C, Dalnodar D, Mrázová K, Hrubanová K, Krzyzanek V, Nebesarova J, Samek O, Šedrlová Z, Slaninova E, Sedláček P, Obruča S, Fritz I. Glycogen, poly(3-hydroxybutyrate) and pigment accumulation in three Synechocystis strains when exposed to a stepwise increasing salt stress. Journal of Applied Phycology. June 2022. 34 (3):1227 - 1241.

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The cyanobacterial genus Synechocystis is of particular interest to science and industry because of its efficient phototrophic metabolism, its accumulation of the polymer poly(3-hydroxybutyrate) (PHB) and its ability to withstand or adapt to adverse growing conditions. One such condition is the increased salinity that can be caused by recycled or brackish water used in cultivation. While overall reduced growth is expected in response to salt stress, other metabolic responses relevant to the efficiency of phototrophic production of biomass or PHB (or both) have been experimentally observed in three Synechocystis strains at stepwise increasing salt concentrations. In response to recent reports on metabolic strategies to increase stress tolerance of heterotrophic and phototrophic bacteria, we focused particularly on the stress-induced response of Synechocystis strains in terms of PHB, glycogen and photoactive pigment dynamics. Of the three strains studied, the strain Synechocystis cf. salina CCALA192 proved to be the most tolerant to salt stress. In addition, this strain showed the highest PHB accumulation. All the three strains accumulated more PHB with increasing salinity, to the point where their photosystems were strongly inhibited and they could no longer produce enough energy to synthesize more PHB.

Conference presentations and posters | 2017

GrateAdvance - Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies

Feldmeier S, Wopienka E, Schwarz M. GrateAdvance - Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies. 5th Central European Biomass Conference, Workshop Highlights of Bioenergy Research 2017 (oral presentation). January 2017, Graz, Austria.

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Conference presentations and posters | 2020

GrateAdvance - Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies

Barroso G, Essl M, Feldmeier S, Mehrabian R, Nussbaumer T, Öhman M, Reiterer T, Schwarz M, Shiehnejad-Hesar A, Wopienka E. GrateAdvance - Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies. 6th Central European Biomass Conference, 2020, Graz.

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Conference presentations and posters | 2020

GrateAdvance – Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies

Barroso G, Essl M, Feldmeier S, Mehrabian R, Nussbaumer T, Öhman M, Reiterer T, Schwarz M, Shiehnejad-Hesar A, Wopienka E. GrateAdvance – Advanced adjustable grate solutions for future fuel flexible biomass combustion technologies. 6th Central European Biomass Conference - IEA-Workshop: TASK 32 (oral presentation). 2020.

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Other Publications | 2023

Green Carbon as reducing agent in iron and steel production via the blast furnaces

Deutsch R, Krammer G, Kienzl N, Strasser C. Green Carbon as reducing agent in iron and steel production via the blast furnaces. BEST Center Day. 28 June 2023

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Iron production via blast furnace utilizes coal and coke to reduce iron oxides resulting in high greenhouse gas emissions. This important issue for the iron and steel industry may be mitigated by application of biomass-based reducing agents (bioreducer).

Peer reviewed papers | 2017

Green P – Nutzung von Verkehrsflächen zur Biomasseproduktion

Lichtenegger K, Zellinger M, Schipfer F. Green P – Nutzung von Verkehrsflächen zur Biomasseproduktion. Biobased Future 7. Jänner 2017.

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Other Publications | 2023

GreenCarbon Biochar - bio-oil - gas

Wopienka E. GreenCarbon. BEST Center Day. 28 June 2023

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Simple biorefinery concepts for the production of sustainable carbon products are investigated in the GreenCarbon Lab at the Wieselburg site of BEST. The heart of the GreenCarbon Lab consists of two pyrolysis units: A lab-scale reactor for testing new input materials as well as conducting detailed parameter studies to reveal the correlation of input material, process conditions and products formed, and a pilot-scale to implement and validate knowledge gained in the laboratory environment to
produce specific GreenCarbon products. Also, product batches in larger quantities (approx. 0,1 – 5 tons) can be manufactured for subsequent application tests – e.g. as part of industrial trials at company partners. In addition, equipment for process and product analysis enables a detailed study of the conversion reactions and the characterization of the products obtained.

Other Publications | 2020

GreenGas die Alternative zu Erdgas

Strasser C, Luisser M, Drosg B. GreenGas die Alternative zu Erdgas. TGA Planung 2021. December 2020.

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Conference presentations and posters | 2010

Grid autarchy of automated pellets combustion systems by the means of thermoelectric generators

Höfteberger E, Moser W, Aigenbauer S, Friedl G, Haslinger W. Grid autarchy of automated pellets combustion systems by the means of thermoelectric generators, Thermoelectrics goes Automotive 2010, 9th-10th of December 2010, Berlin, Germany.

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Other Publications | 2022

Grundlagenforschung Smart- und Microgrids / Endbericht

Innovative, selbstlernende Systemregler für dezentrale Energieressourcen & Microgrids

Michael Zellinger, Michael Stadler

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Mikro-Netze (Microgrids), ein Unterbereich der Intelligenten Strom/Energie-Netze (Smartgrids),
die sich durch eine enge räumliche Bindung von Energieerzeugungseinheiten und Verbraucher
auszeichnen wird international ein sehr starkes Wachstum zugeschrieben. Microgrids sind kleine,
lokale Energienetze für Strom, Wärme und Kälte, die Haushalte, Betriebe und Gemeinden mit
Energie versorgen. Diese lokalen und regionalen Konzepte der Energieversorgung können in
Zukunft einen wesentlichen Beitrag in Richtung Energieunabhängigkeit und effizientere
Integration von Erneuerbaren in das Energiesystem leisten. Sie können ihren Energiebedarf
selbstständig aus erneuerbaren Energien oder anderen Energieformen decken, etwa Biomasse,
Wärmepumpen, PV, Windräder oder Kraftwärmekopplungen. Diese können nach den
individuellen Zielen der Gemeinden, Haushalte oder der Betriebe gesteuert werden, um
Kostenreduktionen, CO2 Einsparungen oder eine Erhöhung des Unabhängigkeitsgrades zu
realisieren. Sie berechnen den aktuellen und zukünftigen Verbrauch und können Energie im
Bedarfsfall dorthin verlagern, wo sie gerade benötigt wird, oder sie reduzieren den
Energieverbrauch direkt.

Reports | 2023

Guidebook for the Digitalisation of District Heating: Transforming Heat Networks for a Sustainable Future

Final Report of DHC Annex TS4

Schmidt, Dietrich (ed.) et al. (2023). Guidebook for the Digitalisation of District Heating: Transforming Heat Networks for a Sustainable Future, Final Report of DHC Annex TS4. AGFW Project Company, Frankfurt am Main, Germany.

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Other Publications | 2014

H2S and NH3 tolerance of acidophilic sulfur-oxidizing bacteria

Rachbauer L, Lorber G, Ortner M, Bochmann G. H2S and NH3 tolerance of acidophilic sulfur-oxidizing bacteria, 4th Central European Biomass Conference 2014, 15th-18th of January 2014, Graz, Austria.

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Reports | 2020

Handbook: Technical options for retrofiting industries with bioenergy

Rutz D, Janssen R, Reumerman P, Spekreijse J, Matschegg M, Bacovsky D, et al. Handbook: Technical options for retrofiting industries with bioenergy. March 2020

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Other papers | 2016

Harmonised Greenhouse Gas Calculations for Electricity, Heating and Cooling from Biomass

Ludwiczek N, Bacovsky D, Sonnleitner A, Strasser C. Harmonised Greenhouse Gas Calculations for Electricity, Heating and Cooling from Biomass. e-nova 2016 (oral presentation). November 2016, Pinkafeld, Austria.

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Other papers | 2017

HCNG or hythane production from biomass steam gasification

Kraussler M, Priscak J, Hofbauer H. HCNG or hythane production from biomass steam gasification. 5th Central European Biomass Conference (oral presentation). January 2017, Graz, Austria.

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Peer reviewed papers | 2015

Heat pump enhanced heat recovery from flue gas of wood chips combustion

Hebenstreit B, Schwabl M, Höftberger E, Kronberger B, Gappmayr B, Gautsch H, Lundgren J, Toffolo A. Heat pump enhanced heat recovery from flue gas of wood chips combustion, INFUB 10th European Conference on Industrial Furnace and Boilers 2015, 7th-10th of April 2015, Porto, Portugal.

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Conference presentations and posters | 2012

High efficient industrial process carbon capture (CC) – Field tests

Martini S, Kleinhappl M, Zeisler J. High efficient industrial process carbon capture (CC) – Field tests, 20th European Biomass Conference 2012, 18th-22nd of June 2012, Milano, Italy. p 1127-1131.

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In large scale industrial processes, such as iron production, or in gasification based process chains (coal/biomass to synthesis gas, fuel, or power, etc.), the separation of CO2 (Carbon Capture-CC) can lead to ecological and procedural benefits. Chemical absorption of CO2 is a well proved technology for CC with comparatively low electrical energy demand. However, the high heat demand, absorption kinetics, CO2 capacity and sorbent degradation are limiting factors for the industrial application. Further investigation and development of sorbent-solutions in relation to specific gas conditions are necessary for optimisation. For testing different sorbent-solutions a mobile test plant was designed and built up. Focus of this work was the evaluation of process key data for CC in blast furnace gas under real conditions. The tests have been carried out continuously up to 300 hours. Aqueous monoethanol-amine (MEA), diethanol-amine (DEA) and methyl-diethanol-amine (MDEA) solutions have been investigated. Detailed analyses of the process gas, analyses of used liquids (chemical properties, degradation products) and the examination of process data lead to further development in process design, control strategies for specific applications and give routes for an efficient implementation of CC to increase the benefit in the overall process chain.

Peer reviewed papers | 2019

High Utilization of Humidified Ammonia and Methane in Solid Oxide Fuel Cells: An Experimental Study of Performance and Stability

Stöckl B, Preininger M, Subotic V, Gaber C, Seidl M, Sommersacher P, Schröttner H, Hochenauer C. High Utilization of Humidified Ammonia and Methane in Solid Oxide Fuel Cells: An Experimental Study of Performance and Stability. Journal of The Electrochemical Society 2019.166:F774-F783.

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Wastewater contains high amounts of unused energy in the form of dissolved ammonia, which can easily be converted into gaseous humidified ammonia via membrane distillation, thus providing a potential fuel for solid oxide fuel cells. This study presents comprehensive investigations of the use of humidified ammonia as the primary fuel component in high-fuel utilization conditions. For these investigations, large planar anode- and electrolyte-supported solid oxide single cells were operated at the respective appropriate temperatures, 800°C and 850°C. Fueled with ammonia, both cells exhibited excellent ammonia conversion ( > 99.5%) in addition to excellent performance output and fuel utilization. In 100 h stability tests performed at 80% fuel utilization, the cells exhibited stable performance, despite scanning electron microscopy analyzes revealing partial impairments to the nickel parts of both cells due to the formation and subsequent decomposition of nickel nitride. This study also demonstrates that methane is a perfect additional fuel component for humidified ammonia streams, as steam supports the internal reforming of methane. Alternating and direct current as well as electrochemical impedance measurements with a variety of ammonia/steam/methane/nitrogen fuel mixtures were used to evaluate the performance potential of the cells, and proved their stability over 48 h in highly polarized conditions.

Conference presentations and posters | 2011

Highlights der Bioenergieforschung

Fercher E. Highlights der Bioenergieforschung, Central Europe Biomass Conference 2011, 26th-29th of January 2011, Graz, Austria.

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Other Publications | 2017

Honeycomb catalysts integrated in firewood stoves - potentials and limitations

Reichert G, Haslinger W, Kirchhof JM, Schmidl C, Sedlmayer I, Schwabl M, Stressler H, Sturmlechner R, Wöhler M, Hochenauer C. Honeycomb catalysts integrated in firewood stoves - potentials and limitations. 5th Central European Biomass Conference (oral presentation). January 2017, Graz, Austria.

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Other Publications | 2023

How bioenergy contributes to a sustainable future

Bacovsky D. How bioenergy contributes to a sustainable future. BEST Center Day. 28 June 2023

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Bioenergy is the largest source of renewable energy today. It is versatile and can provide heat, power and transport services, and biomass can also serve as a raw material for the production of chemicals and materials. If done responsibly, and wherever it substitutes for fossil fuels, bioenergy provides substantial GHG emission savings, diversifies energy sources, improves energy supply security and provides income through regional biomass supply chains.

Conference presentations and posters | 2020

How to create value chains from different feedstocks

Enigl M, How to create value chains from different feedstocks. 6th Central Eurpean Biomass Conference, 22-254 January 2020, Graz.

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Other Publications | 2019

How to Introduce the Future Transport System

Bacovsky D. How to Introduce the Future Transport System. Transport Decarbonisation Workshop. November 2019.

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Other Publications | 2021

HPC - Workshop

Experimentelle Analyse, Simulation und Regelung von Absorptionswärmepumpen/-kältemaschinen

Zlabinger S, Unterberger V, Gölles M, Wernhart M, Rieberer R, Poier H, Rohinger C, Kemmerzehl C, Halmdienst C. Experimentelle Analyse, Simulation und Regelung von Absorptionswärmepumpen/-kältemaschinen. Online-Workshop im Rahmen des FFG-Projekts HPC ("4. Ausschreibung Energieforschung 2017") am 09.04.2021.

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Durch die vermehrte Einbindung von Absorptionswärmepumpen und -kältemaschinen in bestehende und zukünftige Energiesysteme des Kälte- und Wärmesektors kann der Anteil erneuerbarer Energien deutlich gesteigert werden. Um dies erfolgreich umsetzen zu können, müssen die Betriebsstrategien und Regelungen dieser Systeme jedoch in der Lage sein, auch mit dynamischen und stark variierenden Betriebsbedingungen umgehen zu können. Dieser Herausforderung hat sich das von der FFG geförderte Projekt HPC – heat pumping system control gewidmet. Im Rahmen dieses Workshops sollen die Ergebnisse und deren Nutzen für die Praxis präsentiert und diskutiert werden.

Other papers | 2015

Hydrogen from the high temperature water gas shift reaction with an industrial Fe/Cr catalyst using biomass gasification tar rich synthesis gas

Chianese, S, Loipersböck J, Malits M, Rauch R, Hofbauer H, Molino A, Musmarra D. Hydrogen from the high temperature water gas shift reaction with an industrial Fe/Cr catalyst using biomass gasification tar rich synthesis gas. Fuel Processing Technology. 2015;132:39-48.

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The high temperature water gas shift reaction (HTS) over an iron/chromium (Fe/Cr) industrial catalyst was investigated in a pilot scale plant consisting of two fixed-bed reactors arranged in series and a biomass-derived tar-rich synthesis gas was used as a feed-stream. CO conversion and selectivity for the water gas shift reaction were evaluated through parameter variation. Four dry gas hourly space velocities (GHSv) and two steam to dry synthesis gas ratios (H2O/SGd) equal to 52% v/v and 60% v/v were investigated at temperatures (T) of 350–450 °C. CO conversion was investigated by varying H2S concentration 180–540 ppmv (dry basis) at a temperature of 425 °C, considering two GHSVd. The highest CO conversion (~ 83%) was observed in the basis case at 60% v/v H2O/SGd, and 450 °C. The catalyst appeared to be resistant to sulfur poisoning deactivation, and achieved 48% CO conversion at the maximum H2S concentration used.

Other papers | 2015

Hydrogen from the high temperature water gas shift reaction with an industrial Fe/Cr catalyst using biomass gasification tar rich synthesis gas

Chianese S, Loipersböck J, Malits M, Rauch R, Hofbauer H, Molino A, et al. Hydrogen from the high temperature water gas shift reaction with an industrial Fe/Cr catalyst using biomass gasification tar rich synthesis gas. Fuel Process Technol 2015;132:39-48.

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Other Publications | 2013

Hydrogen Production by Steam Reforming of Hydrocarbons from Biomass Gasification Modeling and Experimental Study

Sadooghi, P. Hydrogen Production by Steam Reforming of Hydrocarbons from Biomass Gasification Modeling and Experimental Study, Ph.D. Thesis, Vienna University of Technology, Vienna, Austria, 2013.

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Peer reviewed papers | 2017

Hydrogen production from biomass: The behavior of impurities over a CO shift unit and a biodiesel scrubber used as a gas treatment stage

Loipersböck J, Lenzi M, Rauch R, Hofbauer H. Hydrogen production from biomass: The behavior of impurities over a CO shift unit and a biodiesel scrubber used as a gas treatment stage. Korean Journal of Chemical Engineering. 22 June 2017; 1-6.

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Most of the hydrogen produced is derived from fossil fuels. Bioenergy2020+ and TU Wien have been working on hydrogen production from biomass since 2009. A pilot plant for hydrogen production from lignocellulosic feedstock was installed onsite using a fluidized bed biomass gasifier in Güssing, Austria. In this work, the behavior of impurities over the gas conditioning stage was investigated. Stable CO conversion and hydration of sulfur components could be observed. Ammonia, benzene, toluene, xylene (BTX) and sulfur reduction could be measured after the biodiesel scrubber. The results show the possibility of using a commercial Fe/Cr-based CO shift catalyst in impurity-rich gas applications. In addition to hydrogen production, the gas treatment setup seems to also be a promising method for adjusting the H2 to CO ratio for synthesis gas applications.

Peer reviewed papers | 2016

Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification

Kraussler M, Binder M, Schindler P, Hofbauer H. Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification. Biomass and Bioenergy. 24 December 2016;

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Peer reviewed papers | 2018

Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification

Kraussler M, Binder M, Schindler P, Hofbauer H. Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification. Biomass and Bioenergy. April 2018, 111: 320-329.

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Dual fluidized bed biomass steam gasification generates a high calorific, practically nitrogen-free product gas with a volumetric H2 content of about 40%. Therefore, this could be a promising route for a polygeneration concept aiming at the production of valuable gases (for example H2), electricity, and heat. In this paper, a lab-scale process chain, based on state of the art unit operations, which processed a tar-rich product gas from a commercial dual fluidized bed biomass steam gasification plant, is investigated regarding H2 production within a polygeneration concept. The lab-scale process chain employed a water gas shift step, two gas scrubbing steps, and a pressure swing adsorption step. During the investigations, a volumetric H2 concentration of 99.9% with a specific H2 production of 30 g kg−1 biomass was reached. In addition, a valuable off-gas stream with a lower heating value of 7.9 MJ m−3 was produced. Moreover, a techno-economic assessment shows the economic feasibility of such a polygeneration concept, if certain feed in tariffs for renewable electricity and H2 exist. Consequently, these results show, that the dual fluidized bed biomass steam gasification technology is a promising route for a polygeneration concept, which aims at the production of H2, electricity, and district heat.

Conference presentations and posters | 2014

Hydroprocessing and Catalytic Cracking of Fischer-Tropsch Biowaxes to Biokerosene

Rauch R, Jovcic M, Aichernig C, Ililopoulou E, Heracleous E, Lapppas AA. Hydroprocessing and Catalytic Cracking of Fischer-Tropsch Biowaxes to Biokerosene, Processing Technologies for the Forest and Biobased Products Industries PTF BPI 2014, 24th-25th of September 2014, Kuchl, Austria.

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Conference presentations and posters | 2010

Hydroprocessing of Fischer Tropsch biowaxes to 2nd generation biofuels

Schablitzky H, Rauch R, Hofbauer H. Hydroprocessing of Fischer Tropsch biowaxes to 2nd generation biofuels, ICPS 2010, 7th-9th of September 2010, Leipzig, Deutschland.

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Upgrading of Fischer–Tropsch (FT) biowaxes to second-generation biofuels via hydroprocessing is the final
step for increasing the fuel amount of the overall biomass conversion route: gasification of lignocellulosic biomass, FT synthesis, and hydroprocessing. The typical FT product portfolio consists of high molecular weight paraffinic waxes as the main product and FT fuels in the diesel and naphtha boiling range. OMV's objective and contribution to the project focus on achieving coprocessing of FT biowaxes with fossil feedstock using existing hydrotreating plants of crude oil refineries. Various test runs have been examined with a conventional refining catalyst under mild conditions (380–390°C, 5.8 MPa; WHSV, 0.7–1.3 h−1) in a pilot plant. Pure FT biowax is converted to gases, fuels, and an oil/waxy residue in a fixed-bed reactor with a porous catalyst layer technology. The presence of hydrogen in the reaction chamber reduces the fast deactivation of the catalyst caused by the formation of a coke layer around the catalyst particle surface and saturates cracked hydrocarbon fragments. Another approach is the creation of synthetic biodiesel components with excellent fuel properties for premium fuel
application. Basically, premium diesel fuel differs from standard diesel quality by cetane number and cold flow
properties. Hydroprocessed synthetic biodiesel (HPFT diesel) has compared to conventional diesel advantages in many aspects. Depending on the catalyst selected, premium diesel quality can be obtained by shifting cold flow
operability properties of HPFT fuels to a range capable even under extreme cold conditions. In addition, a highquality kerosene fraction is obtained to create bio jet fuels with an extremely deep freezing point, as low as −80°C. The isomerization degree, as well as the carbon number distribution of high paraffinic profile, and the branching degree have a major impact on the cold flow properties and cetane number. FT diesel has, compared to HPFT diesel, a slightly higher derived cetane number (DCN>83) and a cloud point of −9°C, whereas HPFT diesel reaches values as low as −60°C. Although the HPFT naphtha obtained consists of high amounts of isoparaffins, the RON/ MON values are comparable to fossil straight-run naphtha. The reason is that the branching degree of isoparaffins from the naphtha fraction is not sufficiently high enough to reach the typical octane number values of gasoline products delivered at filling stations. Assuming the goal of launching a premium biodiesel or biokerosene fuel to the market, these hydroprocessed synthetic biofuels from FT biowaxes are ideal blending components.

Other papers | 2016

Hythane from biomass steam gasification as natural gas substitute in industrial applications

Kraussler M, Schindler P, Hofbauer H. Hythane from biomass steam gasification as natural gas substitute in industrial applications. Biorestec (poster). October 2016, Sitges, Spain.

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Reports | 2016

IEA Bioenergy Countries´ Report

Bacovsky D, Dissauer C, Enigl M, Ludwiczek N, Pointner C, Sonnleitner A, Verma VK. IEA Bioenergy Countries´ Report. IEA Bioenergy Countries´ Report. August 2016.

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Reports | 2017

IEA Bioenergy Task 39 Report on State of the Technology of Algae Bioenergy

Bacovsky D, Sonnleitner A, Laurens L, McMillan JD. IEA Bioenergy Task 39 Report on State of the Technology of Algae Bioenergy. 5th Central European Biomass Conference, Workshop Highlights of Bioenergy Research 2017 (oral presentation). January 2017, Graz, Austria.

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Reports | 2022

IEA Bioenergy Task 44: Flexible Bioenergie und Systemintegration (Arbeitsperiode 2019 - 2021)

Gölles M, Schipfer F. IEA Bioenergy Task 44: Flexible Bioenergie und Systemintegration (Arbeitsperiode 2019 - 2021). IEA Task Bioenergy 44. BMK. Schriftenreihe 49/2023. Deutsch, 40 Seiten.

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Ziel des Tasks ist es, Bioenergielösungen als flexible Ressource in einem dekarbonisierten Energiesystem herauszuarbeiten. Dabei sollen Typen, Qualität und Status von flexibler Bioenergie erhoben sowie Barrieren und Entwicklungsbedarf im Gesamtsystemkontext (Strom-, Wärme- und Transportsektor) identifiziert werden.

Conference presentations and posters | 2023

IEA Cross TCP Workshop: Towards a flexible, cross sectoral energy supply

Gölles M, Schubert T, Lechner M, Mäki E, Kuba K, Leusbrock I, Unterberger V, Schmidt D. IEA Cross TCP Workshop: Towards a flexible, cross sectoral energy supply.7th Central European Biomass Conference CEBC 2023. 18. January 2023. Graz. Oral Presentation.

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A sustainable energy supply can only be achieved by a flexible, cross-sectoral energy system utilizing the specific advantages of the various renewable technologies. In this workshop possible roles of different technologies will be discussed based on a previous discussion of the users’ needs among the different sectors. In this a special focus should be given on the flexibility provision via the heating sector. By bringing together different users, representing municipal and industrial energy supply, and technological experts from different IEA Technology Collaboration Programmes (TCP) the workshop should support a holistic discussion.

List of presentations: 

  • Wien Energie‘s vision of a sustainable energy and ressource supply of Vienna, Teresa Schubert, Wien Energie, Austria
  • Digitalization of energy management systems – optimization of internal energy use as an industrial company, Maria Lechner, INNIO Jenbacher, Austria
  • Flexible Bioenergy and System Integration, Elina Mäki, VTT Technical Research Centre of Finland, Finland Task Leader – IEA Bioenergy Task 44 Flexible Bioenergy and System Integration
  • Use Case: Syngas platform Vienna for utilization of biogenic residues, Matthias Kuba, BEST – Bioenergy and Sustainable Technologies, Austria
  • Transformation of District Heating and Cooling Systems towards high share of renewables, Ingo Leusbrock, AEE INTEC, Austria – Lead of Austrian delegation – IEA DHC Annex TS5 Integration of Renewable Energy Sources into existing District Heating and Cooling Systems
  • Opportunities offered by long-term heat storages and large-scale solar thermal systems, Viktor Unterberger, BEST – Bioenergy and Sustainable Technologies, Austria Task Manager – IEA SHC Task 68 Efficient Solar District Heating Systems
  • Possibilities through digitalization on the example of District Heating and Cooling, Dietrich Schmidt, Fraunhofer Institute for Energy Economics and Energy System Technology IEE, Germany – Operating Agent – IEA DHC Annex TS4 Digitalisation of District Heating and Cooling

List of contributing IEA Tasks:

Conference presentations and posters | 2022

IEA SHC Task 68: Efficient Solar District Heating Systems

Unterberger V, Berberich M, Putz S, Byström J, Gölles M. IEA SHC Task 68: Efficient Solar District Heating Systems. ISEC 2022. 5 - 07. April 2022, Graz. Poster presentation.

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Conference presentations and posters | 2014

Impact of firebed temperature on PM1 formation in a small-scale biomass furnace

Gehrig M, Pelz S, Thorwarth H, Haslinger W, Jaeger D. Impact of firebed temperature on PM1 formation in a small-scale biomass furnace, International Aerosol Conference 2014, 31st of August-5th of September 2014, Busan, Korea.

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Peer reviewed papers | 2016

Impact of Na Promoter on Structural Properties and Catalytic Performance of CoNi/Al2O3 Nanocatalysts for the CO Hydrogenation Process: Fischer–Tropsch Technology

Nikparsa P, Mirzaei AA, Rauch R. Impact of Na Promoter on Structural Properties and Catalytic Performance of CoNi/Al2O3 Nanocatalysts for the CO Hydrogenation Process: Fischer–Tropsch Technology. Catalysis Letters. January 2016;146(1): 61-71.

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Peer reviewed papers | 2018

Impact of Oxidizing Honeycomb Catalysts Integrated in Firewood Stoves on Emissions under Real-Life Operating Conditions

Reichert G, Schmidl C, Haslinger W, Stressler H, Sturmlechner R, Schwabl M, Wöhler M, Hochenauer C. Impact of Oxidizing Honeycomb Catalysts Integrated in Firewood Stoves on Emissions under Real-Life Operating Conditions. Fuel Processing Technology. 2018; 117: 300-313.

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Catalytic systems integrated in firewood stoves represent a secondary measure for emission reduction. This study evaluates the impact on emissions of two types of honeycomb catalysts integrated in different firewood stoves. The tests were conducted under real-life related testing conditions. The pressure drop induced by the catalyst's carrier geometry affects primary combustion conditions which can influence the emissions. A negative primary effect reduces the catalytic efficiency and has to be considered for developing catalyst integrated solutions. However, a significant net emission reduction was observed. The ceramic catalyst reduced CO emissions by 83%. The metallic catalyst reduced CO emissions by 93% which was significantly better compared to the ceramic catalyst. The net emission reduction of OGC (~30%) and PM (~20%) was similar for both types of catalysts. In most cases, the “Ecodesign” emission limit values, which will enter into force in 2022 for new stoves, were met although the ignition and preheating batches were respected. PM emission composition showed a lower share of elemental (EC) and organic carbon (OC) with integrated catalyst. However, no selectivity towards more reduction of EC or OC was observed. Further investigations should evaluate the long term stability under real-life operation in the field and the effect of the catalyst on polycyclic aromatic hydrocarbon (PAH) emissions.

Peer reviewed papers | 2020

Impact of residual fuel ash layers on the catalytic activation of K-feldspar regarding the water–gas shift reaction

Fürsatz K, Kuba M, Janisch D, Aziaba K, Hammerl C, Chlebda D, Łojewska J, Hofbauer H. Impact of residual fuel ash layers on the catalytic activation of K-feldspar regarding the water–gas shift reaction. Biomass Conversion and Biorefinery. 2020

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Interaction of biomass ash and bed materials in thermochemical conversion in fluidized beds leads to changes of the bed particle surface due to ash layer formation. Ash components present on the bed particle surface strongly depend on the ash composition of the fuel. Thus, the residual biomass used has a strong influence on the surface changes on bed particles in fluidized bed conversion processes and, therefore, on the catalytic performance of the bed material layers. Ash layer formation is associated with an increase in the catalytic activity of the bed particles in gasification and plays a key role in the operability of different biomass fuels. The catalytic activation over time was observed for K-feldspar used as the bed material with bark, chicken manure, and a mixture of bark and chicken manure as fuels. The changes on the bed material surfaces were further characterized by SEM/EDS and BET analyses. Raman, XPS, and XRD analyses were used to characterize the crystal phases on the bed material surface. An increase in surface area over time was observed for K-feldspar during the interaction with biomass ash. Additionally, a more inhomogeneous surface composition for fuels containing chicken manure in comparison to pure bark was observed. This was due to the active participation of phosphorus from the fuel ash in the ash transformation reactions leading to their presence on the particle surface. A decreased catalytic activity was observed for the same BET surface area compared to bark combustion, caused by the different fuel ash composition of chicken manure.

Peer reviewed papers | 2019

Implementation and long term experiences with a continuous hygienisation process in food industry – A case study

Wöss D, Ortner M, Mensik J, Kirchmayr R, Schumergruber A, Pröll T. Implementation and long term experiences with a continuous hygienisation process in food industry – A case study. Chemical Engineering and Processing - Process Intensification 2019;137:100-107.

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A three tonne/hour batch-type hygienisation process for animal waste was replaced by a fully continuous process including heat integration. The plant is embedded into a pig abattoir including an anaerobic digestion (biogas) plant and gas-engine-based combined heat and power (CHP) production. Pre-heating is done in a series of four tube bundle apparatuses with heat transferred from the hot treated animal waste leaving the hygienisation plant. A closed water loop is used for heat transfer in this heat recovery arrangement. After pre-heating, the feed passes a second series of four tube bundles operated with heat from the biogas CHP plant in order to meet a target temperature of 72 °C at the inlet of the continuous hygienisation section. The material leaving the tube section is finally cooled in a series of four tube bundles and provides heat for pre-heating the feed before it is directed into the biogas plant. The process was started up in 2011 and monitoring results are be presented from 2011 to 2016. With the implementation of the continuous process, energy consumption of the hygienisation step was reduced by 64% for thermal and by 69% for electric energy.

Peer reviewed papers | 2015

Implementation of a firebed cooling device and its influence on emissions and combustion parameters at a residential wood pellet boiler

Gehrig M, Pelz SK, Jaeger D, Hofmeister G, Groll A, Thorwarth H, Haslinger W. Implementation of a firebed cooling device and its influence on emissions and combustion parameters at a residential wood pellet boiler. Applied Energy. 01 December 2015;159: 310-316.

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This study investigates the general concept of reduced firebed temperatures in residential wood pellet boilers. Residential wood pellet boiler development is more and more concerned with inorganic aerosols characterized by a temperature-dependent release from the firebed. Hence, different concepts are applied aiming to reduce firebed temperatures. Unfortunately, these concepts influence not only firebed temperatures, but also other important parameters like air flow rates which may cause unwanted side effects with respect to combustion quality or efficiency. Thus, a new approach was developed solely affecting firebed temperature by implementing a water-based firebed cooling in a 12 kW underfeed pellet boiler. The effectiveness of the cooling was monitored by comprehensive temperature measurement in the firebed. The cooling capacity ranged from 0.4 kW to 0.5 kW resulted in a significant decrease of firebed temperatures. Gaseous emissions remain stable showing no significant changes in major components (O2, CO2, NOx). Furthermore, CO emissions were even reduced significantly by the activated cooling, which was supposedly caused by a stabilized devolatilization due to the firebed cooling. Moreover, the temperature-dependent release of aerosol forming elements was influenced at activated firebed cooling, which is proved by a decrease of 17 wt% of dust (Total Suspended Particles; TSP). At the same time the gaseous emissions of HCl increase, supposedly by a reduced potassium release from the firebed to the gas phase and a subsequently different particle formation. The general concept of reduced firebed temperatures proved to be successful decreasing overall aerosol emissions without impacting combustion quality.

Other papers | 2013

Implementing an advanced waste separation step in an MBT plant: assessment of technical, economic and environmental impacts

Meirhofer M, Piringer G, Rixrath D, Sommer M, Ragossnig AM. Implementing an advanced waste separation step in an MBT plant: Assessment of technical, economic and environmental impacts. Waste Management and Research. 2013;31(10 SUPPL.):35-45.

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Heavy fractions resulting from mechanical treatment stages of mechanical-biological waste treatment plants are posing very specific demands with regard to further treatment (large portions of inert and high-caloric components). Based on the current Austrian legal situation such a waste stream cannot be landfilled and must be thermally treated. The aim of this research was to evaluate if an inert fraction generated from this waste stream with advanced separation technologies, two sensor-based [near-infrared spectroscopy (NIR), X-ray transmission (XRT)] and two mechanical systems (wet and dry) is able to be disposed of. The performance of the treatment options for separation was evaluated by characterizing the resulting product streams with respect to purity and yield. Complementing the technical evaluation of the processing options, an assessment of the economic and global warming effects of the change in waste stream routing was conducted. The separated inert fraction was evaluated with regard to landfilling. The remaining high-caloric product stream was evaluated with regard to thermal utilization. The results show that, in principal, the selected treatment technologies can be used to separate high-caloric from inert components. Limitations were identified with regard to the product qualities achieved, as well as to the economic expedience of the treatment options. One of the sensor-based sorting systems (X-ray) was able to produce the highest amount of disposeable heavy fraction (44.1%), while having the lowest content of organic (2.0% Cbiogenic per kg waste input) components. None of the high-caloric product streams complied with the requirements for solid recovered fuels as defined in the Austrian Ordinance on Waste Incineration. The economic evaluation illustrates the highest specific treatment costs for the XRT (€23.15 per t), followed by the NIR-based sorting system (€15.67 per t), and the lowest costs for the air separation system (€10.79 per t). Within the ecological evaluation it can be shown that the results depend strongly on the higher heating value of the high caloric light fraction and on the content of Cbiogenic of the heavy fraction. Therefore, the XRT system had the best results for the overall GWP [-14 kg carbon dioxide equivalents (CO2eq) per t of input waste] and the NIR-based the worst (193 kg CO2 eq per t of input waste). It is concluded that three of the treatment options would be suitable under the specific conditions considered here. Of these, sensor-based sorting is preferable owing to its flexibility. © The Author(s) 2013.

Conference presentations and posters | 2013

Improvement of real life operation performance of residential wood combustion

Schmidl C, Haslinger W, Aigenbauer S, Figl F, Kirchhof JM, Moser W, Reichert G, Schwabl M, Verma V, Wöhler M. Improvement of real life operation performance of residential wood combustion, 21st European Biomass Conference and Exhibition 2013, 3rd-7th of June 2013, Copenhagen, Denmark.

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Conference presentations and posters | 2014

Improvement of the accuracy of short-term corrosion probe measurements by addition of a mass loss probe

Retschitzegger S, Brunner T, Obernberger I. Improvement of the accuracy of short-term corrosion probe measurements by addition of a mass loss probe, Proc. of the Conference Impacts of Fuel Quality on Power Production and Environment 2014, 26th-31st of October 2014, Snowbird, USA.

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Peer reviewed papers | 2018

Improving exploitation of chicken manure via two-stage anaerobic digestion with an intermediate membrane contactor to extract ammonia

Wang X, Gabauer W, Li Z, Ortner M, Fuchs W. Improving exploitation of chicken manure via two-stage anaerobic digestion with an intermediate membrane contactor to extract ammonia. Bioresource Technology 2018;368:811-814.

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This study describes a modified process of ammonia release through pre-hydrolysis – ammonia removal via membrane contactor – methanization for counteracting ammonia inhibition in anaerobic digestion of chicken manure. In the pre-hydrolysis step, ammonia was rapidly released within the first 3–5 days. 78%-83% of the total nitrogen was finally converted into total ammonia/ammonium (TAN) with volatile fatty acids concentration of approximately 300 g/kg·VS. In the ammonia removal process, diluting the hydrolyzed chicken manure to 1:2, the TAN could be reduced to 2 g/kg in 21 h when pH was increased to 9. The final BMP test of chicken manure verified that lower TAN concentration (decreased to 2 g/kg) significantly reduced inhibitory effects, obtaining a high methane yield of 437.0 mL/g·VS. The investigations underlined several advantages of this modified process.

Conference presentations and posters | 2014

Improving small scale combustion systems for better air quality

Schmidl C, Moser W, Reichert G. Improving small scale combustion systems for better air quality, TERMICA DA BIOMASSE E QUALITÀ DELL’ARIA 2014, 25th of June 2014, Udine, Italy.

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Other papers | 2016

Improving the propanol yield of mixed alcohol synthesis based on wood gas derived from biomass steam gasification

Binder M, Rauch R, Hofbauer H. Improving the propanol yield of mixed alcohol synthesis based on wood gas derived from biomass steam gasification. iSGA 2016 - 5th International Symposium on Gasification and its Applications (invited lecture). November/December 2016, Busan, Korea.

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Other papers | 2012

In vitro toxicological characterization of particulate emissions from residential biomass heating systems based on old and new technologies

Jalava PI, Happo MS, Kelz J, Brunner T, Hakulinen P, Mäki-Paakkanen J, et al. Invitro toxicological characterization of particulate emissions from residential biomass heating systems based on old and new technologies. Atmos Environ. 2012;50:24-35.

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Residential wood combustion causes major effects on the air quality on a global scale. The ambient particulate levels are known to be responsible for severe adverse health effects that include e.g. cardio-respiratory illnesses and cancer related effects, even mortality. It is known that biomass combustion derived emissions are affected by combustion technology, fuel being used and user-related practices. There are also indications that the health related toxicological effects are influenced by these parameters. This study we evaluated toxicological effects of particulate emissions (PM 1) from seven different residential wood combusting furnaces. Two appliances i.e. log wood boiler and stove represented old batch combustion technology, whereas stove and tiled stove were designated as new batch combustion as three modern automated boilers were a log wood boiler, a woodchip boiler and a pellet boiler. The PM 1 samples from the furnaces were collected in an experimental setup with a Dekati ® gravimetric impactor on PTFE filters with the samples being weighed and extracted from the substrates and prior to toxicological analyses. The toxicological analyses were conducted after a 24-hour exposure of the mouse RAW 264.7 macrophage cell line to four doses of emission particle samples and analysis of levels of the proinflammatory cytokine TNFα, chemokine MIP-2, cytotoxicity with three different methods (MTT, PI, cell cycle analysis) and genotoxicity with the comet assay. In the correlation analysis all the toxicological results were compared with the chemical composition of the samples. All the samples induced dose-dependent increases in the studied parameters. Combustion technology greatly affected the emissions and the concomitant toxicological responses. The modern automated boilers were usually the least potent inducers of most of the parameters while emissions from the old technology log wood boiler were the most potent. In correlation analysis, the PAH and other organic composition and inorganic ash composition affected the toxicological responses differently. In conclusion, combustion technology largely affects the particulate emissions and their toxic potential this being reflected in substantially larger responses in devices with incomplete combustion. These differences become emphasized when the large emission factors from old technology appliances are taken into account. © 2012 Elsevier Ltd.

Other papers | 2019

Increased economic efficiency of dual fluidized bed plants via model-based control

Nigitz T, Gölles M, Aichernig C, Schneider S, Hofbauer H, Horn M. Increased economic efficiency of dual fluidized bed plants via model-based control. In 27th European Biomass Conference and Exhibition. 2019. p. 533 - 538 https://doi.org/10.5071/27thEUBCE2019-2BO.6.5

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Sustainable technologies can hardly compete with fossil-based technologies in terms of economic efficiency. One sustainable technology with special relevance due to its wide range of application and industrial readiness is biomass gasification using a dual fluidized bed (DFB). The economic challenges of a DFB gasification plant are addressed without constructional measures by adapting a current control strategy. This paper proposes a model-based control strategy aiming for increased economic efficiency of a DFB gasification plant considering exemplarily the “HGA Senden” in Ulm, Germany. A process analysis reveals high potential for improvement at the current control strategy for the synchronization of product gas production and utilization. A significant surplus of product gas is burned in an auxiliary boiler just for synchronization, and regular manual adjustments by the plant operators at the fuel feed are necessary. The model-based control strategy synchronizes by actuating the auxiliary boiler and the fuel feed simultaneously. The model-based control strategy is experimentally validated for over one month at the “HGA Senden” proofing a significant increase in economic efficiency. So, the economic efficiency of this technology for the sustainable production of energy and products is increased by model-based control.

Peer reviewed papers | 2020

Increased efficiency of dual fluidized bed plants via a novel control strategy

Nigitz T, Gölles M, Aichernig C, Schneider S, Hofbauer H, Horn M. Increased efficiency of dual fluidized bed plants via a novel control strategy. Biomass & Bioenergy. 2020 Okt;141. 105688. https://doi.org/10.1016/j.biombioe.2020.105688

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Industrial plants using DFB biomass gasification are on the verge of profitability. These plants should be operated more economically in order to support the industrial applications for renewable technologies of this kind. Since some parts of such plants are typically difficult to control, a state-of-the-art control strategy is analyzed here in the context of its potential for increased economic efficiency. The DFB gasification plant “HGA Senden” in Ulm, Germany is considered on an exemplary basis here. A process analysis reveals a high potential in the synchronization of product gas generation and utilization. At the present time a relevant surplus of product gas is burned in an auxiliary boiler for synchronization purposes and regular manual adjustments at the fuel feed are necessary by the plant operators. For this synchronization a novel control strategy is developed that actuates the auxiliary boiler and the fuel feed simultaneously. The novel control strategy was experimentally validated for a period of over one month. Due to this long-term evaluation the fuel consumption was reduced by 5% and the manual adjustments of the fuel feed that were necessary on average every 30min were eliminated. As a result DFB gasification plants can be operated more economically by applying the novel control strategy for synchronization of product gas generation and utilization.

Peer reviewed papers | 2022

Increased Flexibility of A Fixed-Bed Biomass Gasifier through Advanced Control

Hollenstein C, Zemann C, Martini S, Gölles M, Felsberger W, Horn M. Increased Flexibility of A Fixed-Bed Biomass Gasifier through Advanced Control. Proceedings of the 30th European Biomass Conference and Exhibition. 2022. 704-711.

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Most industrial fixed-bed biomass gasification systems usually operate at steady-state to produce the maximum amount of energy possible although they can principally modulate their loads to compensate for the fluctuations of other volatile renewable energy systems. To unleash their full load modulation capability, their typically traditional control strategies should be improved, their gas residence times affected by typically basic char removal strategies adjusted and any required manual interaction of an operator avoided. In this respect, a new controller for the char handling (accumulation and removal) of the reduction zone in a fixed-bed biomass gasifier of a representative industrial small-scale gasification system is developed and experimentally verified. This new controller consists of a recursive least-squares estimator for the flow resistance of the gasifier representing the amount of char inside and a switching controller for rotating a grate located at its bottom. The experimental verification reveals that only the traditional (pressure-based) controller requires manual adjustment of the thresholds. Moreover, the new controller (flow resistance based) significantly reduces the fluctuation range during partial load and stabilizes the temperature and pressure downstream the gasifier. This provides the basis for enhancing its fuel flexibility too and is an important feature for flexible operation in future.

Other Publications | 2023

Increased flexibility of a fixed-bed biomass gasifier through advanced control

Hollenstein C, Martini S, Gölles M, Felsberger W, Horn M. Increased flexibility of a fixed-bed biomass gasifier through advanced control. BEST Center Day. 28 June 2023

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Other papers | 2021

Increasing economic efficiency of cultivating microalgae by recycling process water

Neubauer M, Bauer L, Lanschützer E, Cayir P, Sonnleitner A, Meixner K, Fritz I, Drosg B. Increasing economic efficiency of cultivating microalgae by recycling process water. 29th European Biomass Conference and Exhibition, EUBCE 2021, 26-29 April 2021. 2021.

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This abstract gives a glimpse of the output revealed in a project focusing on recycling used medium from algae cultivation. In close cooperation with the University of Natural Resources and Life Sciences Vienna, the Institute of Microbiology - The Czech Academy of Sciences as well as the algae biomass production company Ecoduna GmbH, it was possible to target industrial needs with scientific research approaches.

Conference presentations and posters | 2023

Increasing the flexibility of a fixed-bed biomass gasifier through model-based control strategies: method and practical verification

Hollenstein C, Zemann C, Martini S, Gölles M, Felsberger W, Horn M. Increasing the flexibility of a fixed-bed biomass gasifier through model-based control strategies: method and practical verification. 7. Mitteleuropäische Biomassekonferenz: CEBC 2023. 20. Jan 2023. Oral presentation.

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Future hybrid energy systems require flexible technologies for compensating the volatile nature of most renewable energies. As such, fixed-bed biomass gasifiers are especially relevant as they allow a flexible production of heat, electricity and in a broader sense bio-based products (e.g. biochar). Thus, flexible fixed-bed biomass gasifiers will continuously become more relevant for a sustainable and highly flexible energy and resource system (bioeconomy).

 

However, due to their current economic dependency on specific feed in tariffs for the produced electricity, they are almost always operated at nominal load, to maximize the electricity production. Thus, their potential for flexibility has not been revealed up to now. Consequently, the currently applied control strategies are typically designed with the focus on steady-state operation. Any operation differing from nominal load typically requires manual interventions of the plant operators to avoid lower efficiencies or operational difficulties. Thus, currently applied control strategies do not allow a fully-automatic and flexible operation of the gasifiers.

 

To unleash the full potential of the gasifiers’ flexibility, new and more advanced control strategies able to handle varying operating conditions automatically are required. For this reason, this contribution aims for the development of a model-based control strategy, since it allows to explicitly consider all the correlations between the different process variables, and an efficient adaptation of the control strategy to different plants. The development was carried out on the basis of a representative industrial small-scale fixed-bed biomass gasifier operated as combined heat and power plant (CHP) with a nominal capacity of 300 kWth and 150 kWel. In this contribution we present the developed method as well as the practical verification of the model-based controller for the industrial small-scale fixed-bed biomass gasification plant.

 

The practical verification revealed a significant potential for flexibility increase by the new model-based control strategy in comparison to state-of-the-art control strategies. For example, the new controller performs a step-wise load change from 150 kWel to 100 kWel (-33%) within less than 2 min without affecting the gasification performance. The new control leads to a much more homogeneous gasification, in particular during partial load operation, and reduces the fluctuation margin of relevant process parameters to less than 1%. This controlled stabilization and homogenization of the gasification at different operating conditions is also a prerequisite for further future flexibilization measures, e.g. the extension of the feedstock variety (fuel flexibility) or increasing product flexibility.

 

Due to the modular and model-based design, the new control strategy can also be implemented on other fixed-bed gasifiers of the same type without requiring any structural modifications, by solely adjusting the model parameters appropriately. Furthermore, the new control strategy makes only use of sensors and actuators typically already available in state-of-the-art fixed-bed gasification systems. In conclusion, the model-based control strategy to be presented states a very important contribution towards flexible fixed-bed biomass gasification systems.

 

Conference presentations and posters | 2020

Individiual heat management in the living room

Schwabl M. Individiual heat management in the living room. 6th Central European Biomass Conference (oral presentation. 2020.

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Conference presentations and posters | 2020

Individual heat management in the living room

Schwabl M. Individual heat management in the living room. 6th Central European Biomass Conference, 22-24 January 2020, Graz.

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Conference presentations and posters | 2020

Influence of ash forming elements from biogenous residues on fluidized bed conversion processes

Fürsatz K, Influence of ash forming elements from biogenous residues on fluidized bed conversion processes. 6th Central Eurpean Biomass Conference, 22-24 January 2020, Graz.

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Peer reviewed papers | 2015

Influence of bed material coatings on the water-gas-shift reaction and steam reforming of toluene as tar model compound of biomass gasification

Kuba M, Havlik F, Kirnbauer F, Hofbauer H. Influence of bed material coatings on the water-gas-shift reaction and steam reforming of toluene as tar model compound of biomass gasification. Biomass and Bioenergy. 7 August 2015;89:40-49

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A promising technology replacing fossil energy carriers for the production of electricity, heat, fuels for transportation and synthetic chemicals is steam gasification of biomass in a dual fluid bed (DFB). The principle of this technology is the separation into a gasification and a combustion reactor. Bed material, nowadays olivine, circulates between them, and has two functions. It acts as a heat carrier from the combustion to the gasification zone and as catalyst regarding gasification reactions. Today, an alternative to olivine does yet not exist.

In this work, experiments in a lab-scale test rig were performed investigating the catalytic activity of different fresh and used bed materials, such as olivine and quartz. The enhancement of the catalytic activity due to particle coatings was tested regarding the water-gas-shift reaction and steam reforming of toluene. Calcite is known as an active material in this respect and is therefore used as a benchmark substance.

Experiments revealed a correlation between the catalytic activity of bed particle coatings towards both the water-gas-shift reaction and the reduction of toluene by steam reforming. Results showed bed material particles with a calcium (Ca)-rich layer achieve satisfactory conversion of carbon monoxide and reduction of toluene. Furthermore, a qualitative comparison regarding hydrogen production relative to the benchmark material CaO is given for the water-gas-shift and steam reforming of toluene and ethene - used as model substance for lighter hydrocarbons. These results are the basis for further research on the catalytic properties of potential bed materials for DFB gasification of biomass.

Peer reviewed papers | 2020

Influence of bed materials on the performance of the Nong Bua dual fluidized bed gasification power plant in Thailand

Siriwongrungson V, Hongrapipat J, Kuba M, Rauch R, Pang S, Thaveesri J, Messner M, Hofbauer H. Influence of bed materials on the performance of the Nong Bua dual fluidized bed gasification power plant in Thailand. Biomass Conversion and Biorefinery. 2020;

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Bed materials and their catalytic activity are two main parameters that affect the performance of the dual fluidized bed (DFB) gasification system in terms of product gas composition and tar levels. Two sources of bed materials were used for the operation of a commercial DFB gasification system in Thailand, using woodchips as a biomass feedstock. One source of the bed materials was the calcined olivine which had been used in the Gussing Plant, Austria, and the other activated bed material was a mixture of fresh Chinese olivine and used Austrian olivine with additives of biomass ash, calcium hydroxide and dolomite. These bed materials were collected and analysed for morphological and chemical composition using a scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). The product gas was cleaned in a scrubber to remove tars, from which the samples were collected for gravimetric tar analysis. Its composition data was automatically recorded at the operation site before it entered the gas engine. From the SEM, EDS and XRF analyses, calcium-rich layers around the bed materials were observed on the activated bed material. The inner layers of bed materials collected were homogeneous. Biomass ash, which was generally added to the bed materials, had significant calcium and potassium content. These calcium-rich layers of the bed materials, from the calcium hydroxide, biomass ash and dolomite, influenced system performance, which was determined by observing lower tar concentration and higher hydrogen concentration in the product gas.

Peer reviewed papers | 2022

Influence of bed materials on the performance of the Nong Bua dual fluidized bed gasification power plant in Thailand

Siriwongrungson V, Hongrapipat J, Kuba M, Rauch R, Pang S, Thaveesri J, Messner M, Hofbauer H. Influence of bed materials on the performance of the Nong Bua dual fluidized bed gasification power plant in Thailand. Biomass Conversion and Biorefinery 2022. 12:2965-2979.

External Link Details

Bed materials and their catalytic activity are two main parameters that affect the performance of the dual fluidized bed (DFB) gasification system in terms of product gas composition and tar levels. Two sources of bed materials were used for the operation of a commercial DFB gasification system in Thailand, using woodchips as a biomass feedstock. One source of the bed materials was the calcined olivine which had been used in the Gussing Plant, Austria, and the other activated bed material was a mixture of fresh Chinese olivine and used Austrian olivine with additives of biomass ash, calcium hydroxide and dolomite. These bed materials were collected and analysed for morphological and chemical composition using a scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). The product gas was cleaned in a scrubber to remove tars, from which the samples were collected for gravimetric tar analysis. Its composition data was automatically recorded at the operation site before it entered the gas engine. From the SEM, EDS and XRF analyses, calcium-rich layers around the bed materials were observed on the activated bed material. The inner layers of bed materials collected were homogeneous. Biomass ash, which was generally added to the bed materials, had significant calcium and potassium content. These calcium-rich layers of the bed materials, from the calcium hydroxide, biomass ash and dolomite, influenced system performance, which was determined by observing lower tar concentration and higher hydrogen concentration in the product gas.

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