During the last years biomass evolved into one of the most important energy sources in Central Europe. Depending on the atmosphere, different types of thermochemical processes can be differentiated: pyrolysis, gasification and combustion, whereas pyrolysis operates without any oxygen in the atmosphere, combustion with the highest ratio of oxygen. Depending on the conversion technology and conversion conditions, different products can be generated: heat, cooling power and electrical power, liquid, gaseous and solid products, such as hydrogen, FT-fuels and biochar.
This work focuses on the valorisation of solid side products of gasification based biomass CHP-systems to increase ecologic and economic benefit. Depending on the conversion process of biomass into producer gas this solid residue consists mainly of ash or of so called biochar with high carbon content. Increasing the amount of biochar leads to a decrease of producer gas, but, with the high market potential of biochar, the economic benefits increase. According to its characteristics (e.g. purity, surface structure) different applications can be addressed and therefore different prices can be achieved. Therefore, extended research on biochar treatment processes and related reaction kinetics of biochar is from crucial importance for the development and optimisation of downstream upgrading processes in order to reach the desired quality of the biochar. In the past, such considerations of utilising side products, like biochar, have not been in the centre of attention during the design phase of gasification reactors. Therefore, the establishment of a finishing-treatment of biochar extracted from a gasification process is under investigation. The focus of this paper lies on the reaction kinetics of biochar activation itself and not the primary material (biomass). In order to derivate correlations between reaction kinetics and atmosphere compositions as well as temperature, experimental test runs are conducted with a Thermogravimetric Analyser (TGA) including a steam furnace, which enables studies of mass and energy changes under defined absolute humidity. To produce applicable and reliable data, the limitations of the TGA-test-setup are evaluated with examinations on variations of sample mass, bulk density, particle size distribution and the gas flow. On this basis the test design is defined with certain specifications on the sample preparation and a constant flow velocity. The investigated biochar taken out the gasification process is dried, milled and sieved for the TGA-tests. The main part is devoted to conduct a detailed investigation changing the content of moisture (H2O) and carbon dioxide (CO2) as well as the temperature. The tests are operated at a temperature range between 700 and 1000°C, H2O-concentrations from 0 to 80 vol% and CO2-concentrations also in the range of 0 to 80 vol%. These systematic experimental variations provide the basis for a model of the reaction kinetics of biochar under different boundary conditions. The data is to be evaluated via the generic model including temperature and the partial pressures of CO2 and H2O. Afterwards it will be matched with conventional models (e.g. Arrhenius plot, linear regression models) to determine their suitability. One of those models was used in the paper of Ollero et al, where the influence of CO2 on the reaction kinetics of olive residue was investigated. 1First results show that the reaction rate of biochar is much lower than the one of olive residue. Effects of treatment conditions on the surface properties are investigated by taking out the treated samples after a defined treatment period at a defined mass loss and subsequent surface analysis (BET, pore size/volume distribution) of the samples. In first BET surface analysis, the treatments of biochar with vapour lead to a surface of approximately 1000m²/g whereas the original sample has a BET surface lower than 150m²/g. This finding leads to the question how the reaction kinetics of a treatment process influences the surface change. The obtained data is taken as basis for developing an upgrading process for biochar to a high value product of the gasification process. In order to prove the suitability of TGA-tests for identifying optimised treatment conditions, further research shall demonstrate the correlation of the lab-scale TGA-results with experiences of pilot scale tests.
 

Warum ist es sinnvoll, Wärmenetze zu verbinden?

• Erläuterung am Beispiel des Projekts Thermaflex
• Drei Wärmenetze bei Leibnitz in der Steiermark.
• Sind gewachsen und haben die Grenzen ihrer Nachbar-Wärmenetze erreicht.
• Die Wärmenetze werden durch zwei getrennte Eigentümer betrieben.

List of presentations:

Biorefineries

• Learnings from biomass combustion towards future bioenergy applications (M. Schwabl)
• Green Carbon perspectives for regional sourcing and decarbonization (E. Wopienka)
• Bioconversion processes for renewable energy and/or biological carbon capture and utilisation (B. Drosg)
• Second generation biomass gasification: The Syngas Platform Vienna – current status and outlook (M. Kuba)
• Utilization of syngas for the production of fuel and chemicals – recent developments and outlook (G. Weber)

Digital methods, tools and sustainability

• Evaluation of different numerical models for the prediction of NOx emissions of small-scale biomass boilers (M. Eßl)
• Digitalization as the basis for the efficient and flexible operation of renewable energy technologies (M. Gölles)
• Smart Control for Coupled District Heating Networks (V. Kaisermayer)
• Integrated energy solutions for a decentral energy future - challenges and solutions (P. Liedtke)
• Wood-Value-Tool: Techno-economic assessment of the forest-based sector in Austria (M. Fuhrmann)

Ash components of biomass fuels can cause fouling, slagging, and bed material agglomeration during thermal utilization in fluidized bed combustion and gasification plants. The influence of ash components on these problems in dual fluidized bed biomass gasification plants is investigated in an industrial scale plant in Güssing, Austria. Samples of fouling are analyzed, and the results are evaluated. The samples were analyzed by X-ray fluorescence analysis and thermal analyses such as thermogravimetric analysis, differential thermal analysis, and differential scanning calorimetry. Mass balances of inorganic matter are presented, evaluating different loop configurations. The analyses showed high potassium contents compared to the fuel ash composition in fouling of up to 23% by weight. The potassium content of fly ash with a particle size smaller than 200 μm is half that of coarse fly ash with a particle size larger than 200 μm. The thermal analyses showed a large difference between samples of inorganic streams such as fly ash or fly char and fouling. Different fractions of fly ash samples (particle fraction smaller than 200 μm and particle fraction larger than 200 μm) showed similar thermal behavior: endothermic weight losses at around 400 C and around 720-820 C caused by decomposition of carbonates. The composition of inorganic matters of fly ash and fly char is similar. The elemental composition of deposits at the cyclone wall and the first heat exchanger in the flue gas path showed high potassium contents up to 23.6%. While samples of fly ash and fly char did not show significant melting in their thermal behavior, melting could be detected with fouling at temperatures higher than 1000 C. Mass balances of inorganic matter showed a flow of potassium oxide from the combustion reactor to the gasification reactor, which leads to unexpected high potassium concentrations in the fly char. A reduction of ash loops reduces the amount of potassium that is transferred from the combustion reactor to the gasification reactor. Recommendations are made for the operation of dual fluidized bed gasification plants in terms of ash handling to reduce tendencies for fouling, slagging, and bed material agglomeration. © 2013 American Chemical Society.

Workshop of the research project ÖKO-OPT-QUART (Ökonomisch optimiertes Regelungs- und Betriebsverhalten komplexer Energieverbünde zukünftiger Stadtquartiere)

The Area Automation and Control at BEST - Bioenergy and Sustainable Technologies GmbH focuses on the optimal operation of sustainable biorefinery and renewable energy systems, the optimal interaction of different technologies and systems and the highly automated operation management
by new digital services.

Modern buildings with floor heating or thermally activated building structures (TABS) offer a significant
potential for shifting the thermal load and thus reduce peak demand for heating or cooling. This potential can be realized with the help of model predictive control (MPC) methods, provided that sufficiently descriptive mathematical models describing the thermal characteristics of the individual thermal zones exist. Creating these by hand or from more detailed simulation models is infeasible for large numbers of zones; instead, they must be identified automatically based on measurement data. We present an approach using only open source tools based on the programming language Julia that allows to robustly identify simple thermal models for heating and cooling usable in MPC optimization. The resulting models are used in a distributed optimization scheme that co-ordinates the individual zones and buildings of a city quarter in order to best support an energy hub.

Buildings with floor heating or thermally activated building structures offer significant potential for shifting the thermal load and thus reduce peak demand for heating or cooling. This potential can be realised with the help of model predictive control (MPC) methods, provided that sufficiently descriptive mathematical models of the thermal characteristics of the individual thermal zones exist. Creating these by hand is infeasible for larger numbers of zones; instead, they must be identified automatically based on measurement data. In this paper an approach is presented that allows automatically identifying thermal models usable in MPC. The results show that the identified zone models are sufficiently accurate for the use in an MPC, with a mean average error below 1.5K for the prediction of the zone temperatures. The identified zone models are then used in a distributed optimisation scheme that coordinates the individual zones and buildings of a city quarter to best support an energy hub by flattening the overall load profile. In a preliminary simulation study carried out for buildings with floor heating, the operating costs for heating in a winter month were reduced by approximately 9%. Therefore, it can be concluded that the proposed approach has a clear economic benefit.

Modern buildings with floor heating or thermally activated building structures (TABS) offer a significant potential for shifting the thermal load and thus reduce peak demand for heating or cooling. This potential can be realized with the help of model predictive control (MPC) methods, provided that sufficiently descriptive mathematical models describing the thermal characteristics of the individual thermal zones exist. Creating these by hand or from more detailed simulation models is infeasible for large numbers of zones; instead, they must be identified automatically based on measurement data. We present an approach using only open source tools based on the programming language Julia that allows to robustly identify simple thermal models for heating and cooling usable in MPC optimization. The resulting models are used in a distributed optimization scheme that co-ordinates the individual zones and buildings of a city quarter in order to best support an energy hub.

 Die Anzahl der installierten Biomasse-Kleinfeuerungsanlagen ist in letzter Zeit deutlich gestiegen. Aus diesem Grund ist es umso wichtiger eine schadstoffarme und effiziente Verbrennung zu ermöglichen. Genau diese Anforderung stellt jedoch eine große Herausforderung für deren Regelung dar. Der optimale Restsauerstoffgehalt des Rauchgases, im Sinne von niedrigen Kohlenmonoxidemissionen (CO-Emissionen) bei bestmöglichem Wirkungsgrad, ist sehr stark vom Betriebszustand, von der Anlagengeometrie und vom verwendeten Brennstoff abhängig. Diese Tatsache wird jedoch derzeit bei den Regelungen von Biomasse-Kleinfeuerungsanlagen nicht oder nur teilweise berücksichtigt. Um hohe CO-Emissionen aufgrund von Sauerstoffmangel in jedem Fall zu vermeiden, werden Biomasse-Kleinfeuerungsanlagen üblicherweise mit vergleichsweise hohem Sauerstoff betrieben. Diese Maßnahme geht jedoch mit einer unerwünschten Reduktion des Wirkungsgrades der Feuerung einher. Diese Arbeit hat zum Ziel eine Strategie zu entwickeln, welche das Luftverhältnis sowie auch die Luftstufung während des Betriebes dahingehend anpasst, dass stets ein möglichst effizienter und dennoch schadstoffarmer Betrieb gewährleistet wird. Die im Rahmen dieser Masterarbeit behandelten Arbeiten, wurden anhand einer handelsüblichen Biomasse-Kleinfeuerungsanlage durchgeführt. Die verwendete Anlage wird mit Hackgut betrieben und hat eine Kesselnennleistung von 30 kW. Für die Anwendung einer Strategie zur Reduktion der CO-Emissionen wäre es von großem Vorteil, wenn der CO-Gehalt des Rauchgases gemessen werden könnte. Derzeit gibt es jedoch nur sehr teure Rauchgasanalyseeinheiten, welche für eine dauerhafte Bestimmung des CO-Gehaltes des Rauchgases geeignet sind. Somit war bis jetzt eine Messung des CO-Gehalts nur bei großen Biomassefeuerungsanlagen wirtschaftlich. In dieser Arbeit wurde zunächst eine Marktanalyse zu preiswerten Sensoren zur Detektion unverbrannter Komponenten im Rauchgas durchgeführt. Es wurden ausschließlich Sensoren untersucht, die aufgrund ihres geringen Preises auch wirtschaftlich eingesetzt werden können. Dabei zeigte sich, dass es derzeit zwei Sensoren gibt, welche diese Anforderungen erfüllen. Diese Sensoren dienen jedoch lediglich zur Detektion von unverbrannten Komponenten im Rauchgas und sind nicht in der Lage den CO-Gehalt des Rauchgases exakt zu messen. Aus diesem Grund wurde der Zusammenhang zwischen CO-Konzentration und Sensorsignal untersucht und anschließend mathematisch beschrieben, wobei die wesentlichen Querempfindlichkeiten berücksichtigt wurden. Da die physikalischen Zusammenhänge sehr komplex und zu einem wesentlichen Teil nicht bekannt waren, wurde das mathematische Modell mit Hilfe der experimentellen Modellbildung ermittelt, wobei die verwendeten Messdaten einen möglichst großen Bereich der verschiedenen Einflussparameter beinhalteten. In weiterer Folge wurden umfassende Testläufe zur Untersuchung der Auswirkung der Leistung, des Luftverhältnisses im Brennstoffbett, des gesamten Luftverhältnisses und des Brennstoffwassergehaltes auf die CO-Emissionen durchgeführt. Die Ergebnisse zeigten, dass es für einen möglichst effizienten und gleichzeitig schadstoffarmen Betrieb notwendig ist, das Luftverhältnis im Brennstoffbett sowie den Sekundär"-luft"-massen"-strom in Abhängigkeit der geforderten Leistung zu variieren. Darauf aufbauend wurde eine geeignete Strategie zur Umsetzung dieser Maßnahmen entwickelt und implementiert. Dabei werden die Führungsgrößen für den Restsauerstoffgehalt sowie das Luftverhältnis im Brennstoffbett laufend an die geforderte Leistung angepasst. Zusätzlich dazu wird die Führungsgröße für den Restsauerstoffgehalt durch einen Suchalgorithmus zur Minimierung der CO-Emissionen variiert. Schlussendlich wurde die entwickelte Strategie mit Hilfe eines typischen Lastzyklus experimentell verifiziert. 

Fixed-bed biomass gasification coupled with internal combustion engines allows an efficient exploitation of biomass for the combined production of heat and power (CHP) at small scale with increased economic viability with respect to combustion-based CHP systems. The main barrier on the way towards a wider market distribution is represented by the fact that a robust practical operation of state-of-the-art fixed-bed biomass gasification systems is limited to very specific fuel properties and steady-state operation. The aim of this work is twofold. On the one hand, it presents the results of a series of test runs performed in a monitored commercial plant under different process conditions, in order to assess its behaviour during load modulation and fuel property variations. On the other hand, an in-house developed thermodynamic equilibrium model was applied to predict the behaviour of the gasification reactor. This gasification model could be used for the development of a model-based control strategy in order to increase the performance of the small-scale gasification system. To assess the general operational behaviour of the whole gasification system an experimental one-week-long test run has been performed by BIOENERGY 2020+ and the Free University of Bozen-Bolzano as round robin test. The plant has been tested under different operating conditions, in particular, varying the load of the engine and the moisture content of the feedstock. The outcomes shown in the present work provide a unique indication about the behaviour of a small-scale fix-bed gasifier working in conditions different from the nominal ones.

To systematically investigate high-temperature corrosion of superheaters in biomass combined heat and power (CHP) plants, a long-term test run (5 months) with online corrosion probes was performed in an Austrian CHP plant (28 MW_NCV; steam parameters: 32 t/h at 480 °C and 63 bar) firing chemically untreated wood chips. Two corrosion probes were applied in parallel in the radiative section of the boiler at average flue gas temperatures of 880 and 780 °C using the steel 13CrMo4-5 for the measurements. Corrosion rates were determined for surface temperatures between 400 and 560 °C. The results show generally moderate corrosion rates and a clear dependence upon the flue gas temperatures and the surface temperatures of the corrosion probes, but no influence of the flue gas velocity has been observed. The data are to be used to create corrosion diagrams to determine maximum steam temperatures for superheaters in future plants, which are justifiable regarding the corrosion rate. Dedicated measurements were performed at the plant during the long-term corrosion probe test run to gain insight into the chemical environment of the corrosion probes. From fuel analyses, the molar 2S/Cl ratio was calculated with an average of 6.0, which indicates a low risk for high-temperature corrosion. Chemical analyses of aerosols sampled at the positions of the corrosion probes showed that no chlorine is present in condensed form at the positions investigated. Deposit probe measurements performed at the same positions and analyses of the deposits also showed only small amounts of chlorine in the deposits, mainly found at the leeward position of the probes. Subsequent to the test run, the corrosion probes have been investigated by means of scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses. The results confirmed the deposit probe measurements and showed only minor Cl concentrations in the deposits and no Cl at the corrosion front. Because, in the case of Cl-catalyzed active oxidation, a layer of Cl is known to be found at the corrosion front, this mechanism is assumed to be not of relevance in the case at hand. Instead, elevated S concentrations were detected at the corrosion front, but the corrosion mechanism has not yet been clarified.

To systematically investigate high-temperature corrosion of superheaters in biomass combined heat and power
(CHP) plants, a long-term test run (5 months) with online corrosion probes was performed in an Austrian CHP plant (28 MWNCV; steam parameters: 32 t/h at 480 °C and 63 bar) firing chemically untreated wood chips. Two corrosion probes were applied in parallel in the radiative section of the boiler at average flue gas temperatures of 880 and 780 °C using the steel 13CrMo4-5 for the measurements. Corrosion rates were determined for surface temperatures between 400 and 560 °C. The results show generally moderate corrosion rates and a clear dependence upon the flue gas temperatures and the surface temperatures of the corrosion probes, but no influence of the flue gas velocity has been observed. The data are to be used to create corrosion diagrams to determine maximum steam temperatures for superheaters in future plants, which are justifiable regarding the corrosion rate. Dedicated measurements were performed at the plant during the long-term corrosion probe test run to gain insight into the chemical environment of the corrosion probes. From fuel analyses, the molar 2S/Cl ratio was calculated with an average of 6.0, which indicates a low risk for high-temperature corrosion. Chemical analyses of aerosols sampled at the positions of the corrosion probes showed that no chlorine is present in condensed form at the positions investigated. Deposit probe measurements performed at the same positions and analyses of the deposits also showed only small amounts of chlorine in the deposits, mainly found at the leeward position of the probes. Subsequent to the test run, the corrosion probes have been investigated by means of scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses. The results confirmed the deposit probe measurements and showed only minor Cl concentrations in the deposits and no Cl at the corrosion front. Because, in the case of Cl-catalyzed active oxidation, a layer of Cl is known to be found at the corrosion front, this mechanism is assumed to be not of relevance in the case at hand. Instead, elevated S concentrations were detected at the corrosion front, but the corrosion mechanism has not yet been clarified.

Measuring the producer gas from biomass gasification is very challenging and the use of several methods is required to achieve a complete characterization. Various techniques are available for these measurements, offering very different affordability or time demand requirements and the reliability of these techniques is often unknown. In this work an assessment of commonly employed measuring methods is conducted with a round robin. The main permanent gases, light hydrocarbons, tars, sulfur and nitrogen compounds were measured by several partners employing a producer gas obtained from fluidized bed gasification of wood and miscanthus with steam. Online and offline methods were used for this purpose and their accuracy, repeatability and reproducibility are here discussed. The results demonstrate the reliability of gas chromatography for measuring the main permanent gases, light hydrocarbons, benzene and H2S, validating the obtained results with other methods. An online method could also measure NH3 with a reasonable accuracy, but deviations were present for compounds at even lower concentrations. Regarding tar sampling and analysis, the main source of variability in the results was the analysis of the liquid samples, especially for heavier compounds. The presented work pointed out the need for a complementary use of several techniques to achieve a complete characterization of the producer gas from biomass gasification, and the suitability of certain online techniques as well as their limitations.

Thermochemical conversion of biomass feedstock via dual fluidized bed steam gasification is a well-proven technology used to produce a medium calorific product gas for various applications in the energy or transportation sector or for chemical syntheses. At unfavorable gasification conditions, undesirable high amounts of tar, which are aromatic hydrocarbons, are present in the product gas. High tar contents are a major problem, and they lead to uneconomic operation due to sharply diminished quality of product gas or unexpected plant shut downs due to fouling of the product gas coolers. Currently, tar content is measured with a discontinuous wet-chemical analysis method, which needs several hours of sample preparation to receive the final tar content. The aim of this study is to establish valid correlations between online measured permanent gas components in the product gas and its tar content. The results show that hydrogen, methane, and ethene concentrations are strongly related to the tar content in the product gas, while the carbon monoxide and carbon dioxide content did not show a clear correlation. Using these correlations with online measured gas components provides the possibility of a direct and prompt response of a plant operator in case of unfavorable gasification conditions. Additionally, an optimization of the plant operation can be conducted and thereby, the operation hours and, consequently, the economic efficiency are improved.

The project BioHeatLABEL aims at the derivation of eco-design criteria for small scale biomass
combustion systems. It is a mirror project to the on-going European preparatory study for solid fuel small combustion installations. The presented paper gives an overview of the on-going work. It presents the applied methodologies so far. Sales and performance data as well as prices are collected for the existing stock as well as for new products. Six Base Cases are defined to best possibly represent market relevant product categories. These Base Cases are (1) log wood boilers with natural draught, (2) log wood boilers with forced draught, (3) wood chips boilers, (4) wood pellets boilers, (5) log wood stoves, and (6) wood pellets stoves. For these product categories the bills of production materials as well as for packaging are collected and information about the end-of-life behaviour is retrieved. Based on the above, preliminary life cycle assessment calculations are performed using the tool EuP EcoReport. The usability of this tool for a sound, reliable and representative life cycle assessment is discussed. Finally, an outlook on the further work is given.

The recovery of phosphorus (P) from sewage sludge ashes has been the focus of recent research due to the initiatives for the use of biogenic resources and resource recovery. This study investigates the ash transformation chemistry of P in sewage sludge ash during the co-gasification with the K-Si- and K-rich agricultural residues wheat straw and sunflower husks, respectively, at temperatures relevant for fluidized bed technology, namely 800 °C and 950 °C. The residual ash was analyzed by ICP­AES, SEM/EDS, and XRD, and the results were compared to results of thermochemical equilibrium calculations. More than 90% of P and K in the fuels were retained in the residual ash fraction, and significant interaction phenomena occurred between the P-rich sewage sludge and the K-rich ash fractions. Around 45–65% of P was incorporated in crystalline K-bearing phosphates, i.e., K-whitlockite and CaKPO4, in the residual ashes with 85–90 wt% agricultural residue in the fuel mixture. In residual ashes of sewage sludge and mixtures with 60–70 wt% agricultural residue, P was mainly found in Ca(Mg,Fe)-whitlockites and AlPO4. Up to about 40% of P was in amorphous or unidentified phases. The results show that gasification provides a potential for the formation of K-bearing phosphates similar to combustion processes.

Agricultural biomasses and residues can play an important role in the global bioenergy system but their potential is limited by the risk of several ash-related problems such as deposit formation, slagging, and particle emissions during their thermal conversion. Therefore, a thorough understanding of the ash transformation reactions is required for this type of fuels. The present work investigates ash transformation reactions and the release of critical ash-forming elements with a special focus on K and P during the single-pellet gasification of different types of agricultural biomass fuels, namely, poplar, grass, and wheat grain residues. Each fuel was gasified as a single pellet at three different temperatures (600, 800, and 950 °C) in a Macro-TGA reactor. The residues from different stages of fuel conversion were collected to study the gradual ash transformation. Characterization of the residual char and ash was performed employing SEM-EDS, XRD, and ICP with the support of thermodynamic equilibrium calculations (TECs). The results showed that the K and P present in the fuels were primarily found in the residual char and ash in all cases for all studied fuels. While the main part of the K release occurred during the char conversion stage, the main part of the P release occurred during the devolatilization stage. The highest releases – less than 18% of P and 35% of K – were observed at the highest studied temperature for all fuels. These elements were present in the residual ashes as K2Ca(CO3)2 and Ca5(PO4)3OH for poplar; K-Ca-rich silicates and phosphosilicates in mainly amorphous ash for grass; and an amorphous phase rich in K-Mg-phosphates for wheat grain residues.

In this study, ash transformation and release of critical ash-forming elements during single-pellet combustion of different types of agricultural opportunity fuels were investigated. The work focused on potassium (K) and phosphorus (P). Single pellets of poplar, wheat straw, grass, and wheat grain residues were combusted in a macro-thermogravimetric analysis reactor at three different furnace temperatures (600, 800, and 950 °C). In order to study the transformation of inorganic matters at different stages of the thermal conversion process, the residues were collected before and after full devolatilization, as well as after complete char conversion. The residual char/ash was characterized by scanning electron microscopy–energy-dispersive X-ray spectroscopy, X-ray diffraction, inductively coupled plasma, and ion chromatography, and the interpretation of results was supported by thermodynamic equilibrium calculations. During combustion of poplar, representing a Ca–K-rich woody energy crop, the main fraction of K remained in the residual ash primarily in the form of K₂Ca(CO₃)₂ at lower temperatures and in a K–Ca-rich carbonate melt at higher temperatures. Almost all P retained in the ash and was mainly present in the form of hydroxyapatite. For the Si–K-rich agricultural biomass fuels with a minor (wheat straw) or moderate (grass) P content, the main fraction of K remained in the residual ash mostly in K–Ca-rich silicates. In general, almost all P was retained in the residual ash both in K–Ca–P–Si-rich amorphous structures, possibly in phosphosilicate-rich melts, and in crystalline forms as hydroxyapatite, CaKPO₄, and calcium phosphate silicate. For the wheat grain, representing a K–P-rich fuel, the main fraction of K and P remained in the residual ash in the form of K–Mg-rich phosphates. The results showed that in general for all studied fuels, the main release of P occurred during the devolatilization stage, while the main release of K occurred during char combustion. Furthermore, less than 20% of P and 35% of K was released at the highest furnace temperature for all fuels.

Fischer-Tropsch (FT) synthesis produces an aqueous stream containing light oxygenates as major by-product. The low carbon concentration of the organics makes its thermal recovery unprofitable. Thus, novel processes are needed to utilize this waste carbon content. In this work, the aqueous phase reforming of the wastewater obtained from a 15 kWth Fischer-Tropsch plant was explored as a promising process to produce hydrogen at mild temperatures. The FT product water was firstly characterized and afterward subjected to the reforming at different reaction temperatures and time, using a platinum catalyst supported on activated carbon. It was observed that, besides activity, the selectivity towards hydrogen was favored at higher temperatures; equally, increasing the reaction time allowed to obtain the total conversion of most molecules found in the solution, without decreasing the selectivity and reaching a plateau at 4 hours in the hydrogen productivity. In order to get more insights into the reaction mechanism and product distribution derived from the APR of FT product water, several tests were performed with single compounds, finding characteristic features. The importance of the position of the hydroxyl group in the molecule structure was highlighted, with secondary alcohols more prone to dehydrogenation pathways compared to primary alcohols. Moreover, no interference among the substrates was reported despite the mixture is constituted by several molecules: in fact, the results obtained with the real FT product water were analogous to the linear combination of the single compound tests. Finally, the reuse of the catalyst showed no appreciable deactivation phenomena.

The direct combustion of the biomass is the most advanced and mature technology in the field of energetic biomass utilisation. The legislations on the amount of emitted pollutants and the plant efficiency of biomass combustion systems are continually being restricted. Therefore constant improvement of the plant efficiency and emission reduction is required Numerical modelling is gaining increasing importance for the development of biomass combustion technologies. In this paper an overview about the numerical modelling efforts deal with the most relevant phenomena in biomass grate firing systems is given. The numerical modelling results in a deeper understanding of the underlying processes in biomass combustion plants. Therefore, it leads to a faster and safer procedure of development of a new technology.

The increased demand for energy from biomass enforces the utilization of new biomass fuels (e.g., energy crops, short-rotation coppices, as well as wastes and residues from agriculture and the food industry). Compared to conventional wood fuels, these new biomass fuels usually show considerably higher ash contents and lower ash sintering temperatures, which leads to increased problems concerning slagging, ash deposit formation, and particulate matter emissions. One possibility to combat these problematic behaviors is the application of fuel additives such as kaolin. In contrast to the usual approach for the application of additives based on an experimental determination of an appropriate additive ratio, this study applies novel and advanced fuel characterization tools for the characterization of biomass/kaolin mixtures. In the first step the pure biomass fuels (softwood from spruce and straw) and the additive were chemically analyzed. On the basis of the analysis theoretical mixing calculations of promising kaolin ratios were conducted. These theoretical mixtures were evaluated with fuel indexes and thermodynamic equilibrium calculations (TEC). Fuel indexes provide the first information regarding high temperature corrosion (2S/Cl) and ash melting tendency (Si + P + K)/(Ca + Mg + Al). TEC can be used for a qualitative prediction of the release of volatile and semivolatile elements (K, Na, S, Cl, Zn, Pb) and the ash melting behavior. Moreover, selected mixtures of spruce and straw with kaolin were prepared for an evaluation and validation of the release behavior of volatile and semivolatile ash forming elements with lab-scale reactor experiments. The validation of the ash melting behavior was conducted by applying the standard ash melting test. It could be shown that the new approach to apply novel and advanced fuel characterization tools to determine the optimum kaolin ratio for a certain biomass fuel works well and thus opens a new and targeted method for additive evaluation and application. In addition, it helps to significantly reduce time-consuming and expensive testing campaigns. © 2013 American Chemical Society.

To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s⁻¹ to 8 m·s⁻¹ have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential.

The torrefaction process is a promising key technology for biomass treatment. An improvement of the fuel properties, e.g. a higher gross calorific value and a resulting increased energy density, is expected. The changed fuel properties in terms of water repellence enable an improved storability. However, the modified fuel characteristics change the combustion behaviour of the fuel. Since small­scale pellet boilers mainly are dedicated to wood pellets, the applicability of torrefied fuel yet remains unclear. Within the EU FP7 project SECTOR, amongst others, the end­use application of torrefied biomass was investigated in several small scale appliances and the behaviour during the stationary operational conditions of the combustion process was assessed. The experimental design was divided in two parts: First, a survey of the combustion appliances was conducted in order to observe the influence of the changed fuel properties on the different boiler systems. Afterwards, the combustion behaviour of torrefied pellets made of different raw material quality was monitored by utilizing the test fuels and monitor the emission release. The results of these experimental series provide an initial indication for the feasibility of the utilization of several torrefied fuels in state­of­the­art pellet boilers.

The aim of this paper is to test the applicability of upgraded agricultural biomass feedstock such as torrefied sunflower husks during combustion in small and medium heating applications. Sunflower husk is formed in large quantities at enterprises producing sunflower oil and can be used as biofuel. However, big problems arise due to the low bulk density of husks and the rapid growth of ash deposits on the heating surfaces of boilers. In order to solve these problems, it was proposed to produce pellets from husks, and to subject these pellets to torrefaction. After torrefaction, net calorific value was increased by 29% while the risk of high temperature corrosion of boilers was reduced. Signs of ash softening neither occurred in combustion of raw nor in combustion of torrefied sunflower husk pellets. High aerosol emissions, already present in raw sunflower husk pellets, could not be mitigated by torrefaction. First combustion results at medium scale furnaces indicated that sunflower husk pellets (both raw and torrefied) in a commercial boiler < 400 kW, operated in a mode with low primary zone temperatures (< 850 °C), meet current emission limits. Regarding the future upcoming emission limits according to the European Medium Combustion Plant Directive, additional measures are required in order to comply with the dust limits.

Coupling biomass gasification with high temperature Solid Oxide Fuel Cells (SOFCs) is a promising solution to increase the share of renewables and reduce emissions. The quality of the producer gas used can, however, significantly impact the SOFC durability and reliability. The great challenge is to ensure undisturbed operation of such system and to find a trade-off between optimal SOFC operating temperature and system thermal integration, which may limit the overall efficiency. Thus, this study focuses on experimental investigation of commercial SOFC single cells of industrial size fueled with different representative producer gas compositions of industrial relevance at two relevant operating temperatures. The extensive experimental and numerical analyses performed showed that feeding SOFC with a producer gas from a downdraft gasifier, with hot gas cleaning, at an operating temperature of 750 °C represents the most favorable setting, considering system integration and the highest fuel utilization. Additionally, a 120 h long-term test was carried out, showing that a long-term operation is possible under stated operating conditions. Local degradation took place, which can be detected at an early stage using appropriate online-monitoring tools.

Several methods are available to predict the combustion behavior of fuels. Fuel indexes have been developed either for specific fuel types (e.g., coal, biomass) or their utilization in combustion technology (fluidized bed, grate systems). This study deals with the validation of fuel indexes for biomass fuels utilized in small-scale appliances for residential heating. Laboratory analysis data of 33 biomass-derived fuels were used for determining indexes for predicting slag formation tendencies. Indexes were selected that have been reported and previously applied in the literature. They vary in terms of their derivation: ratio or concentration of specific components that are relevant for ash chemistry, temperature-based indexes, and empirical correlations. Combustion tests with 9 different small-scale appliances were conducted to gain experimental data. The appliances had a nominal load between 6 kW_th and 140 kW_th. After each experiment, the fraction of fuel ash that formed slag was quantified. Because of several boiler–fuel combinations in total, data from 90 combustion experiments were available for evaluation. The comparison of the quantified slag with the calculated slagging indexes showed that the applicability was strongly dependent on the (chemical) background of the respective index. Also, the fuel composition (e.g., fuels rich in calcium, silicon or phosphorus) plays an important role. Thus, available indexes are not applicable without restrictions and require a closer look on fuel properties and possible ash transformation mechanisms. Overall, the comparison of the fuel indexes with practical data (slag formation) also indicated an influence of the combustion technologies and operation conditions. The comparison of indexes that predict particulate matter and nitrogen oxide emissions with data measured during combustion experiments was evaluated as well. These results will be described in the second part of the present work.

Several studies pointed out that emission release is related to the concentration of particular elements in the fuel. Fuel indexes were developed to predict emissions of biomass combustion based on the elemental composition of the fuel. This study focuses on emissions of different biomass combustion technologies for domestic heating. Based on combustion tests with a wide range of fuel qualities we validated fuel indexes from the literature. We calculated the values for predicting total suspended particulate (TSP) matter and nitrogen oxide (NO_x) emission of 39 biomass-derived fuels. Combustion tests conducted in 10 different small-scale appliances provided experimental data. The combustion technologies had a nominal load between 6 and 140 kW_th. We measured TSP and NO_x emissions during the stable phases of the experiments. The evaluation considered 529 combustion test intervals. All tested indexes for predicting the TSP corresponded well to the measured values. The correlation analysis confirmed that these indexes are associated with each other and are basically dominated by the concentration of potassium. The results regarding NO_x emissions confirm previous findings from the literature by showing the typical nonlinear relation between nitrogen content of the fuel and NO_x in the flue gas. Overall the comparison of the fuel indexes with the practical data indicated also an influence of the combustion technologies.

Substitution of fossil fuels for production of electricity, heat, fuels for transportation and chemicals can be realized using biomass steam gasification in a dual fluidized bed (DFB).

Interaction between biomass ash and bed material in a fluidized bed leads to transformation of the bed particle due to enrichment of components from the biomass ash resulting in the development of ash layers on the bed particle surface. These ash-rich particle layers enhance the catalytic activity of the bed material regarding the water-gas-shift reaction and the reduction of tars.

The water-gas-shift reaction at conditions typical for dual fluidized bed biomass gasification at a temperature of 870 °C was investigated. Diffusion and heat transfer limitations were minimized using a lab-scale experimental set-up consisting of a gas mixing section and a quartz glass reactor in which the catalyst is investigated.

Der Einfluss von Nährstoffzusammensetzung und Additivzugabe beim anaeroben Abbau organischer Substanz stieß in den letzten Jahren vermehrt auf Interesse. Im Besonderen Spurenelemente haben erwiesenermaßen erheblichen Einfluss auf u.a. methanogene Archaeen und deren metabolische Aktivität. Massive Probleme der Prozessstabilität speziell bei Monovergärung unterschiedlichster Substrate können durch Co-Fermentation oder gezielte Zudosierung von Spurenelementmischungen überwunden werden. Ein profundes Verständnis der Wirkung dieser Elemente auf die verschiedenen mikrobiellen Spezies im Biogasreaktor als auch ihre Verfügbarkeit, ist die Voraussetzung für eine wirtschaftliche Gestaltung des anaeroben Fermentationsprozesses organischer Roh- als auch Reststoffe. Der heutige Stand-der-Technik zur Analyse von Biogasproben hat seinen Ursprung in der Wasser-, Abwasser- und Schlammanalytik und besteht aus einem einzelnen Filtrationsschritt vor Elementdetektion mittels ICP-OES bzw. ICP-MS. Diese Methodik erlaubt nur einen äußerst begrenzten Einblick in die Verteilung von essentiellen Spurenelementen in Anaerobreaktoren. Eine aussagekräftige Beurteilung der mikrobiellen Verfügbarkeit von beispielsweise Cobalt, Nickel oder Molybdän ist somit nur eingeschränkt möglich. Ziel dieser Arbeit war es, eine bestehende Methode zur sequentiellen Extraktion aus dem Bereich der Boden- und Sedimentanalytik für die Anwendung auf Biogasproben zu adaptieren. Der daraus resultierende Einblick in die Verteilung von Spurenelementen in den einzelnen Fraktionen erlaubt eine genauere Bewertung der mikrobiellen Verfügbarkeit von Nährstoffen in Biogasreaktoren, verglichen mit bestehenden analytischen Untersuchungsmethoden. Anforderungen an das Verfahren wie die Reproduzierbarkeit der Daten, zeitsparende Analytik und wirtschaftliche Realisierbarkeit konnten erfüllt werden. Wiederfindungsraten zwischen 90 und 110 % wurden für die wichtigsten Spurenelemente erreicht. Durch die sequentielle Extraktion konnte gezeigt werden, dass essenzielle Mikro-Nährstoffe bis zu 98 % in einer unlöslichen Form vorliegen können. Die Ergebnisse dieser Arbeit belegen die Anwendbarkeit der entwickelten Methodik zur Spurenelement-Extraktion in Anaerob-Systemen.

Several energy and agricultural commodities have experienced higher price volatility in recent years. Management of price risks usually leads to additional costs that are often shared and transmitted along the supply chain to the final consumers. Only little information is currently available on how price volatility of woody biomass commodities has developed compared to energy and agricultural commodities in recent years. We compute the historic price volatility of woody biomass commodities using the standard deviation of log returns as well as univariate GARCH models. The results show that the price volatility of several woody biomass commodities has increased in recent years. However, the price volatility of woody biomass is still lower compared to the price volatility of agricultural commodities and fossil fuels. The analysis of factors and linkages provides insights of the current biomass market developments.

Using solid oxide fuel cells in biomass gasification based combined heat and power production is a promising option to increase electrical efficiency of the system. For an economically viable design of gas cleaning units, fuel cell modules and further development of suitable degradation detection methods, information about the behavior of commercially available cell designs during short-term poisoning with H2S can be crucial. This work presents short-term degradation and regeneration analyses of industrial-relevant cell designs with different anode structure and sulfur tolerance fueled with synthetic product gas from wood steam gasification containing 1 to 10 ppmv of H2S at 750°C and 800°C. Full performance regeneration of both cell types was achieved in all operating points. The high H2O content and avoided fuel depletion may have contributed to a lower performance degradation and better regeneration of the cells. A strong influence of the catalytically active anode volume on poisoning and regeneration behavior was quantified, thereby outlining the importance of considering the anode structure besides the sulfur tolerance of the anode material. Hence, cells with less sulfur tolerant anode material but larger anode volume might outperform cells less sensitive to sulfur in the case of an early detection of a gas cleaning malfunction.

Biomass plays a key role to achieve the EU's 20-20-20 energy and climate targets. Because of rising European demand and limited domestic resources, the EU relies on worldwide imports. Given this framework, the present thesis explores the inuences on wood pellet supply chains considering dierent environmental policies, price risks and the eect of torrefaction pretreatment. The examinations refer to three real case studies for pellet trade from Australia, Canada, and Russia to Europe. In the rst investigation, the eciency of co-ring imported wood pellets in terms of CO2 savings and related subsidy schemes is analysed. Scenarios show that co-ring biomass is ecient to contribute to the EU energy targets. Though, policy makers could use these instruments more eective when directing sourcing decision towards options with even less environmental impacts. The second analysis explores the inuence of statistically derived price risks on total supply chain economics. It is shown that price risks can eect strong uctuations in the short term, which seriously aect the protability of individual trade routes. Securing the supply chain is mainly based on individual producer-buyer agreements, personal branch experiences and fast reactions on the subsidy system. Systematic evaluation of supply chains could contribute to a more reliable market and thus foster investment decisions. In the last investigation, the economic and environmental performance of potential torrefaction-based supply chains is assessed. As a result, torrefaction-based supply
chains turn out to be a certain alternative to conventional ones. Though, still huge research eorts and industrial demonstration are required to make torreed biomass a real alternative on the market.

Empirical analyses of interlinkages and price dependencies in the forest-based sector support the forecast of market developments and the design of efficient utilization pathways. This article aims at analysing price cointegration between roundwood (sawlogs, pulpwood), sawmill by-products (sawdust, wood chips) and wood products (pellets, particle board) in the forest-based sector in Austria. Monthly price data for the period 2005–2019 were used for the following statistical tests: (1) The Augmented-Dickey-Fuller and Zivot-Andrews unit root tests were conducted to investigate stationarity of the data; (2) The Johansen Cointegration test was pairwise applied to price time series; (3) The Granger Causality test was used for cointegrated time series to examine which one is price leading. Furthermore, sawmill by-product prices were modelled as Vector Error Correction Models (VECM) to analyse their common behaviour. The dataset was divided to a training (2005–2017) and test (2018–2019) subset to assess the prediction accuracy of the models. The training data were used to estimate a VAR model as basis for forecasts, which were compared to the test data. Results show that sawdust prices are cointegrated and thus modelled with pellet and particle board prices. In contrast, wood chips are used for several applications and thus prices are cointegrated and modelled with prices of sawlogs, pulpwood, pellets and particle board. The comparison with the test data showed that forecasts were able to predict data from 2018 to 2019 well. However, a decrease in prices, starting in 2019 and intensified by the Covid-19 pandemic, could not be fully captured by these forecasts.

Anaerobic digestion offers a good opportunity to degrade residues from breweries to biogas. To improve the anaerobic degradation process thermal pretreatment of brewers' spent grains (BSG) offers the opportunity to increase degradation rate and biogas yield. Aim of the work is to show the influence of the thermal pretreatment of BSG to anaerobic digestion. BSG were pretreated at different temperature levels from 100 to 200°C. The biogas production of thermally pretreated BSG lies between 30 and 40% higher than for untreated reference. The temperature of the pretreatment process has a significant influence on the degradation rate or gas yield, respectively. Up to a temperature of 160°C, the biogas yield rises. Temperatures over 160°C result in a slower degradation and decreasing biogas yield. Substrate with and without pretreatment gave a daily biogas yield of 430 and 389 Nm³ × kg^-1 VS, respectively. Batch analysis of the biochemical methane potential gives a total methane yield of 409.8 Nm3 CH₄ × kg^-1 VS of untreated brewers' spent grains and 467.6 Nm3 CH₄ × kg^-1 VS of the pretreated samples. For pretreatment energy balance estimation has been carried out. Without any heat recovery demand is higher than the energy surplus resulting from pretreatment of BSG. With energy recovery by heat exchanger the net energy yield could be increased to 38.87 kWh × kg^-1 FM or 8.81%. © 2015 American Institute of Chemical Engineers Environ Prog.

The food and beverage industry offers a wide range of organic feedstocks for use in biogas production by means of anaerobic digestion (AD). Microorganisms convert organic compounds—solid, pasty, or liquid ones—within four steps to biogas mainly consisting of CH₄ and CO₂. Therefore, various conversion technologies are available with several examples worldwide to show for the successful implementation of biogas technologies on site. The food and beverage industry offer a huge potential for biogas technologies due to the sheer amount of process residues and their concurrent requirement for heat and power. The following study analyzes specific industries with respect to their implementation potential based on arising waste and heat and power demand. Due to their chemical composition, several feedstocks are resistant against microbiological degradation to a great extent. A combination of physical-, chemical-, and microbiological pretreatment are used to increase the biological availability of the feedstock. The following examples will discuss how to best implement AD technology in industrial processes. The brewery industry, dairy production, slaughterhouses, and sugar industry will serve as examples.

Anaerobic acidification of pressed sugar beet pulp (PSBP) is a promising strategy for the transition towards a circular economy. In this work, volatile fatty acids were produced by anaerobic acidification of PSBP and subsequently converted to mcl-polyhydroxyalkanoates. The results point to mesophilic acidification as superior to thermophilic one. At the same time, the pH regulated at the value of 6.0 showed a decisive advantage over both the pH of 7.0 and the lack of pH regulation. Furthermore, the conditions with a hydraulic retention time (HRT) of 10 days significantly outperformed those with an HRT of 6 days. The best-performing process (mesophilic, pH controlled at 6, HRT of 10 days) was successfully scaled up to a 250 L reactor, reaching a volatile fatty acid (VFA) concentration of up to 27.8 g L-1. Finally, the produced VFA were investigated as feedstock for mcl-PHA producers, Pseudomonas citronellolis and Pseudomonas putida. Both strains grew and produced PHA successfully, with P. citronellolis reaching a biomass of 15.6 g L-1 with 38% of mcl-PHA, while P. putida grew to 15.2 g L-1 with a polymer content of 31%. This study proves that acidified PSBP is a valuable feedstock for mcl-PHA production and an important approach to developing biorefineries.

Bioeconomy strategies promote higher shares of biomass products in material and energy sectors. Deploying by-products from sawmills is therefore of major interest. This study aims at analyzing market characteristics and implications of bioeconomy strategies by combining three methods: First, an econometric supply and demand model for sawmill by-products (SBP) was estimated based on data from 2001 to 2020. Second, the model was used to analyze a reference and a bioeconomy scenario. Third, a use case was analyzed dealing with the integration of wood gasification and BioSNG (Synthetic Natural Gas) production into Austrian flows of SBP. The results indicate that SBP supply reacts unit-elastic to sawnwood exports, while both supply and demand respond inelastic to SBP prices. Demand is positively inelastic related to SBP as input in panel and pellet production. In a bioeconomy scenario, long-term supply would exceed demand, resulting in additional SBP to be used for gasification. A 100 MW BioSNG plant converting these SBP could provide 528 MWh BioSNG per year. This is a 11 % share of the Austrian target value of 5 TWh green gas.

The number of large-scale solar thermal installations has increased rapidly in Europe in recent years, with 70 % of these systems operating with flat-plate solar collectors. Since these systems cannot be easily switched on and off but directly depend on the solar radiation, they have to be combined with other technologies or integrated in large energy systems. In order to most efficiently integrate and operate solar systems, it is of great importance to consider their expected energy yield to better schedule heat production, storage and distribution. To do so the availability of accurate forecasting methods for the future solar energy yield are essential. Currently available forecasting methods do not meet three important practical requirements: simple implementation, automatic adaption to seasonal changes and wide applicability. For these reasons, a simple and adaptive forecasting method is presented in this paper, which allows to accurately forecast the solar heat production of flat-plate collector systems considering weather forecasts. The method is based on a modified collector efficiency model where the parameters are continuously redetermined to specifically consider the influence of the time of the day. In order to show the wide applicability the method is extensively tested with measurement data of various flat-plate collector systems covering different applications (below 200 Celsius), sizes and orientations. The results show that the method can forecast the solar yield very accurately with a Mean Absolute Range Normalized Error (MARNE) of about 5 % using real weather forecasts as inputs and outperforms common forecasting methods by being nearly twice as accurate.

n the course of this study the direct utilization of ammonia in different types of solid oxide fuel cells (SOFCs), such as anode- and electrolyte-supported SOFC, is investigated. Experiments in low fuel utilization, exhibited excellent performance of ammonia in SOFCs, although the power outputs of equivalent hydrogen/nitrogen fuels were not attained due to the incomplete endothermic ammonia decomposition. Next, the single cells were operated under high fuel utilization conditions and methane was added to the humidified ammonia stream, where they showed excellent ammonia- and methane conversions. The stability of the cells used was proven over a period of at least 48 hours with a variety of fuel mixtures. Post mortem scanning electron microscopy analysis of the anode micro-structures indicated nitriding effects of nickel, as microscopic pores and enlargements of the metallic parts occurred. Finally, a long-term test over 1,000 hours was carried out using a ten-layer stack consisting of electrolyte-supported cells.

The Alpine Region is characterized by a high density of biomass processing and conversion plants. Alps4GreenC sets the scene for transnational utilization of biomass residues in biochar-based value chains. The project aims at:

• Researching opportunities for conversion of biomass residues with focus on biochar production.
• Increasing awareness of citizens, plant owners, policy makers and all involved stakeholders.
• Establishing connection and coordination among Austria, Italy and Slovenia.

Direct ethanol fuel cells (DEFC) still lack active and efficient electrocatalysts for the alkaline ethanol oxidation reaction (EOR). In this work, a new instant reduction synthesis method was developed to prepare carbon supported ternary PdNiBi nanocatalysts with improved EOR activity. Synthesized catalysts were characterized with a variety of structural and compositional analysis techniques in order to correlate their morphology and surface chemistry with electrochemical performance. The modified instant reduction synthesis results in well-dispersed, spherical Pd85Ni10Bi5 nanoparticles on Vulcan XC72R support (Pd85Ni10Bi5/C(II-III)), with sizes ranging from 3.7 ± 0.8 to 4.7 ± 0.7 nm. On the other hand, the common instant reduction synthesis method leads to significantly agglomerated nanoparticles (Pd85Ni10Bi5/C(I)). EOR activity and stability of these three different carbon supported PdNiBi anode catalysts with a nominal atomic ratio of 85:10:5 were probed via cyclic voltammetry and chronoamperometry using the rotating disk electrode method. Pd85Ni10Bi5/C(II) showed the highest electrocatalytic activity (150 mA⋅cm−2; 2678 mA⋅mg−1) with low onset potential (0.207 V) for EOR in alkaline medium, as compared to a commercial Pd/C and to the other synthesized ternary nanocatalysts Pd85Ni10Bi5/C(I) and Pd85Ni10Bi5/C(III). This new synthesis approach provides a new avenue to developing efficient, carbon supported ternary nanocatalysts for future energy conversion devices.

The results of experimental work to investigate the effects of air staging on emissions from energy crop combustion in small scale applications are presented. Five different biomass fuels (wood, willow, miscanthus, tall fescue and cocksfoot) were combusted in a small scale (35 kW) biomass boiler and three different tests looking at the effects of (1) air ratio in the primary combustion chamber (primary air ratio), (2) temperature in the primary combustion chamber, and (3) overall excess air ratio, on NO_x and particulate emissions were conducted. It was shown that by varying the primary air ratio, NO_x emission reductions of between 15% (wood) and 30% (Miscanthus) and PM₁ reductions of between 16% (cocksfoot) and 26% (wood) were possible. For all fuels, both NO_x and particulate emissions were minimised at a primary air ratio of 0.8. Particulate emissions from miscanthus increased with increasing temperature in the primary combustion chamber, NO_x emissions from Miscanthus and from willow also increased with temperature. Overall excess air ratio has no effect on emissions as no significant differences were found for any of the fuels. Emissions of particulates and oxides of nitrogen from a wide range of biomass feedstocks can be minimised by optimising the primary air ratio and by maintaining a temperature in the primary combustion chamber of approximately 900 °C.