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Conference contributions | 2019

Manufacturers' data vs. literature data - a comparison of LCI and LCA results for wood-burning residential heating systems

Rixrath D, Wartha C, Enigl E, Strasser C, Piringer G, Pali E. Manufacturers' data vs. literature data - a comparison of LCI and LCA results for wood-burning residential heating systems. SETAC 19 Conference (Poster). May 2019.

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Scientific Journals | 2019

Mathematical model of Fischer-Tropsch synthesis using variable alpha-parameter to predict product distribution.

Filip L, Zámostný P, Rauch R. Mathematical model of Fischer-Tropsch synthesis using variable alpha-parameter to predict product distribution. Fuel 2019;243:603-609.

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A mathematical model was developed based on data obtained on Fischer-Tropsch (FT) laboratory scale unit operated in steady state, belonging to BIOENERGY 2020+ GmbH, Austria to demonstrate alpha-parameter dependence on carbon number. The lab-scale unit processed the synthesis gas, obtained by the gasification of biomass (woodchips), to produce liquid fuels for transportation applications. The FT reaction took place in a slurry reactor filled with dispersed cobalt-based catalyst. The products were then separated by partial condensation depending on their boiling points. The final output of the FT laboratory scale unit comprised three product streams – wax, diesel and naphtha. The reaction and separation of products were simulated in Aspen Plus software. The mathematical model used kinetic description based on power-law rate equations. The modeled product selectivity was controlled using an alpha-parameter of the Anderson-Schulz-Flory distribution. Because of the significant deviation of products spectrum from typical Anderson-Schulz-Flory distribution, a modified description of reaction selectivity was developed. The description introduces variable alpha-parameter, dependent on number of carbon atoms in the reacting molecule. The mathematical model developed using MATLAB software considered the production of aliphatic paraffins having a number of carbon atoms from C1 to C60. The mathematical model of simulated lab-scale unit comprised an ideally mixed reactor RCSTR and three FLASH2 separators for the separation of desired products. The results from mathematical model were validated by a comparison with experimental results from FT lab-scale unit. The modified polynomial dependency of alpha-parameter on carbon number showed significantly better description of composition and amounts of FT products, especially for wax stream where the description using constant alpha led to enormous deviations. Such better prediction of composition and amounts of acquired products is important for evaluating efficiency of further upgrading the FT products to liquid fuel.


Peer Reviewed Scientific Journals | 2019

New experimental evaluation strategies regarding slag prediction of solid biofuels in pellet boilers

Schön C, Feldmeier S, Hartmann H, Schwabl M, Dahl J, Rathbauer J, Vega-Nieva D, Boman C, Öhman M, Burvall J. New experimental evaluation strategies regarding slag prediction of solid biofuels in pellet boilers. Energy & Fuels. 2019.33:11985-11995

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Pellet boilers and pellet stoves are widely used for heat production. But in most cases, only specific wood pellets with a low ash content are approved due to the increased risk of slagging and limited deashing capacity. The ash fusion test (AFT), according to prCEN/TS 15370-1, is currently the only standard method for the prediction of slagging. This method is not feasible for all biomass fuel types, since sometimes the characteristic temperatures cannot be determined or the characteristic shapes do not occur for temperature determination. Furthermore, the method is costly and requires complex instrumental infrastructure. Hence, a demand for more expressive or more rapid methods to characterize slag formation potential of fuels is often claimed. Based on a literature study, four such laboratory test methods were chosen, partly adapted, and then experimentally investigated. These methods included thermal treatment of the fuel itself or the ashes of the fuel and were the rapid slag test, CIEMAT, the slag analyzer, and the newly developed pellet ash and slag sieving assessment (PASSA) method. Method performance was practically assessed using 14 different biomass fuel pellets, which were mainly from different assortments of wood, but also herbaceous or other nonwoody fuels. The results from the tests with these four alternative methods were evaluated by comparing to both results from standard AFT and results from full-scale combustion tests performed over a maximum of 24 h. Seven different pellet boilers were assessed, of which one boiler was used to apply all 14 test fuels. According to the granulometric ash analysis (i.e., the ratio of >1 mm-fraction toward total ash formed), the sensitivity of the new test methods to depict slagging phenomena at a suitable level of differentiation was assessed. Satisfactory conformity of the boiler ash assessment (reference) was found for both, the slag analyzer and the PASSA method. The latter may, in particular, be seen as a promising and relatively simple low-input procedure, which can provide more real-life oriented test results for fixed-bed combustion. The standardized AFT could, however, not sufficiently predict the degree of slag actually formed in the reference boiler, particularly when only wood fuels are regarded.


Peer Reviewed Scientific Journals | 2019

NPK 2.0: Introducing tensor decompositions to the kinetic analysis of gas–solid reactions

Birkelbach F, Deutsch M, Flegkas S, Winter F, Werner A. NPK 2.0: Introducing tensor decompositions to the kinetic analysis of gas–solid reactions. Int J Chem Kinet. 2019;1–11.

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A method for deriving kinetic models of gas–solid reactions for reactor and process design is presented. It is based on the nonparametric kinetics (NPK) method and resolves many of its shortcomings by applying tensor rank‐1 approximation methods. With this method, it is possible to derive kinetic models based on the general kinetic equation from any combination of experiments without additional a priori assumptions. The most notable improvements over the original method are that it is computationally much simpler and that it is not limited to two variables. Two algorithms for computing the rank‐1 approximation as well as a tailored initialization method are presented, and their performance is assessed. Formulae for the variance estimation of the solution values are derived to improve the accuracy of the model identification and to provide a tool for diagnosing the quality of the kinetic model. The methods effectiveness and performance are assessed by applying it to a simulated data set. A Matlab implementation is available as Supporting Information.


Conference contributions | 2019

Numerical simulation and experimental analysis of a novel small scale biomass grate firing system

Eßl M, Mehrabian R, Shiehnejad-Hesar A, Kelz J, Feldmeier S, Reiterer T, Anca-Couce A, Robert Scharler R. Numerical simulation and experimental analysis of a novel small scale biomass grate firing system. 27th European Biomass Conference & Exhibition (Poster). May 2019.

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Conference contributions | 2019

Nutrient recovery by digestate processing

Drosg B, Fuchs W. Nutrient recovery by digestate processing. Second COASTAL Biogas conference (Roskilde, Denmark). Nov 2019.

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Other Presentations | 2019

Optimization Based Design and Control of Distributed Energy Resources and Microgrids

Stalder M, Optimization Based Design and Control of Distributed Energy Resources and Microgrids. LetsCluster, Lighthouse Summit in the heart of Europe: Smart Energy Generation - Management - Optimization, Smart Home / Building, Interface to the Smart Grid, Microgrids, Electric Grid of the Future, Sector Linking, Graz, Österreich, 25 - 27 März 2019

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Peer Reviewed Scientific Journals | 2019

Overview obstacle maps for obstacle‐aware navigation of autonomous drones

Pestana J, Maurer M, Muschick D, Hofer M, Fraundorfer F. Overview obstacle maps for obstacle-aware navigation of autonomous drones. Journal of Field Robotics 2019.

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Achieving the autonomous deployment of aerial robots in unknown outdoor environments using only onboard computation is a challenging task. In this study, we have developed a solution to demonstrate the feasibility of autonomously deploying drones in unknown outdoor environments, with the main capability of providing an obstacle map of the area of interest in a short period of time. We focus on use cases where no obstacle maps are available beforehand, for instance, in search and rescue scenarios, and on increasing the autonomy of drones in such situations. Our vision‐based mapping approach consists of two separate steps. First, the drone performs an overview flight at a safe altitude acquiring overlapping nadir images, while creating a high‐quality sparse map of the environment by using a state‐of‐the‐art photogrammetry method. Second, this map is georeferenced, densified by fitting a mesh model and converted into an Octomap obstacle map, which can be continuously updated while performing a task of interest near the ground or in the vicinity of objects. The generation of the overview obstacle map is performed in almost real time on the onboard computer of the drone, a map of size urn:x-wiley:15564959:media:rob21863:rob21863-math-0001 is created in urn:x-wiley:15564959:media:rob21863:rob21863-math-0002, therefore, with enough time remaining for the drone to execute other tasks inside the area of interest during the same flight. We evaluate quantitatively the accuracy of the acquired map and the characteristics of the planned trajectories. We further demonstrate experimentally the safe navigation of the drone in an area mapped with our proposed approach.


Peer Reviewed Scientific Journals | 2019

Photoautotrophic production of poly-hydroxybutyrate – First detailed cost estimations

Panuschka S, Drosg B, Ellersdorfer M, Meixner K, Fritz I. Photoautotrophic production of poly-hydroxybutyrate – First detailed cost estimations. Algal Research 2019.41:101558.

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Political, economic and ecological reasons have recently been leading to efforts to replace fossil hydrocarbons and their products in a sustainable way. In order to replace fossil-based polymers, photoautotrophically produced polyhydroxybutryrates (PHBs), which are intracellular carbon storage products of nutrient-deprived microorganisms, seem to be a promising, biobased and biodegradable alternative. Although laboratory and pilot scale experiments have already been performed, no economic evaluation has been carried out so far. Consequently, valid claims on PHB production costs and the influence of different parameters, such as intracellular PHB-content, choice of cultivation system or location, cannot be made. In this study potential demonstration plants, equipped with different photoautotrophic cultivation systems and located at two sites, were designed to identify key parameters for a successful economic realization and implementation. Material and energy balances were determined to reveal specific PHB production costs for four different scenarios. Raw material and operating supply costs, expenditures for plant construction and operation as well as product amounts were determined using literature data for specified results from laboratory and pilot scale experiments. The lowest calculated PHB production price (24 € kg−1) accomplished in a thin-layer-system plant located in Southern Europe with 60% PHB-content of the produced biomass is significantly higher than the current market price of heterotrophically produced PHB. The most important cost factors in all scenarios are cultivation and harvesting costs accounting for 62 to 72% of the total specific production costs, followed by maintenance costs with a cost share of 11 to 14%. Therefore, the choice of a suitable cultivation system is the key driving factor for an economic PHB-production due to the currently high investment costs for photosynthetic biomass production systems. Specific production costs for a Southern compared to a Central European location amount to almost half of the costs.


Peer Reviewed Scientific Journals | 2019

Planning and implementation of bankable microgrids

Stadler M, Nasle A. Planning and implementation of bankable microgrids. The Electricity Journal 2019. 32:24-29.

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Currently, many Microgrid projects remain financially uncertain and not bankable for institutional investors due to major challenges in existing planning and design methods that require multiple, complex steps and software tools.

Existing techniques treat every Microgrid project as a unique system, resulting in expensive, non-standardized approaches and implementations which cannot be compared. That is, it is not possible to correlate the results from different planning methods performed by different project developers and/or engineering companies.

This very expensive individual process cannot guarantee financial revenue streams, cannot be reliably audited, impedes pooling of multiple Microgrid projects into a financial asset class, nor does it allow for wide-spread and attractive Microgrid and Distributed Energy Resource projects deployment.

Thus, a reliable, integrated, and streamlined process is needed that guides the Microgrid developer and engineer through conceptual design, engineering, detailed electrical design, implementation, and operation in a standardized and data driven approach, creating reliable results and financial indicators that can be audited and repeated by investors and financers.

This article describes the steps and methods involved in creating bankable Microgrids by relying on an integrated Microgrid planning software approach that unifies proven technologies and tested planning methods, researched and developed by the United States National Laboratory System as well as the US Department of Energy, to reduce design times.


Conference contributions | 2019

Practical example: manufacturers’ data vs data from ecoinvent database – a comparison of LCI and LCA

Rixrath D, Wartha C, Enigl M, Strasser C, Piringer G. Practical example: manufacturers’ data vs data from ecoinvent database – a comparison of LCI and LCA. 15. Minisymposium Verfahrenstechnik MU Leoben (Poster). 2019.

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Other Presentations | 2019

Primäre und sekundäre Verbesserungen an einem Biomassekessel für Agrarbrennstoffe

Zemann C, Kelz J, Muschick D, Retschitzegger S, Gölles M. Primäre und sekundäre Verbesserungen an einem Biomassekessel für Agrarbrennstoffe. 10. Fachgespräch: Partikelabscheider in häuslichen Feuerungen. 20. März 2019 (2019). [online]. (Tagungsreader, 15). Leipzig: DBFZ. 168 S.

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ie Biomasseverbrennung spielt eine zentrale Rolle bei der Bereitstellung von Wärme aus erneuerbaren Energieträgern. Konventionelle Biomasse-Brennstoffe werden jedoch aufgrund einer steigenden Anzahl stofflicher Verwertungsmöglichkeiten, wie z.B. der Umwandlung in Chemikalien, teurer und schwieriger zugänglich. Agrarbrennstoffe, die bisher nur selten oder gar nicht in Biomasse-Kleinfeuerungen eingesetzt wurden, stellen eine vielversprechende Alternative zu konventionellen Brennstoffen dar. Diese Agrarbrennstoffe, wie zum Beispiel Kurzumtrieb, Maisspindeln oder Stroh sind kostengünstig und in ausreichender Menge vorhanden. Der Einsatz von Agrarbrennstoffen in konventionellen Biomasse-Kleinfeuerungen ist jedoch aufgrund stark variierender Brennstoffeigenschaften mit erhöhten Anforderungen an das Verbrennungssystem verbunden. Erhöhte N, S, Cl, Alkalimetall- und Aschegehalte sowie niedrigere Aschenschmelzpunkte können zu aschebedingten Problemen (Ascheschmelze, Ascheablagerung und Korrosion) sowie erhöhten Konzentrationen von gasförmigen (CO, NOx, HCl und SOx) und partikelförmigen Emissionen bei der Verbrennung führen.

Ziel der in diesem Beitrag präsentierten Arbeiten war die Erhöhung die Brennstoffflexibilität einer handelsüblichen Biomasse-Kleinfeuerung um damit eine Verbrennung von Agrarbrennstoffen mit niedrigen Schadstoffemissionen und einem hohen Wirkungsgrad zu ermöglichen. Hierzu wurde eine modellbasierte Regelung entwickelt, welche insbesondere eine gezielte Einstellung des Luftverhältnisses in der Primärverbrennungszone ermöglicht und damit das Risiko der Ascheschmelze reduziert und Schadstoffmissionen verringert. Soft-Sensoren bestimmen relevante Brennstoffeigenschaften während des Betriebs, welche von der modellbasierten Regelung zur automatischen Anpassung an geänderte Brennstoffeigenschaften genutzt werden. Die modellbasierte Regelung wurde um eine CO-lambda-Optimierung ergänzt, welche auf Basis von Messwerten des Restsauerstoffgehalts und der CO-Emissionen den Wirkungsgrad der Verbrennung maximiert und gleichzeitig die Schadstoffemissionen verringert. Zur weiteren Verringerung von partikelförmigen Schadstoffemissionen wurde ein am Markt verfügbarer Elektrofilter adaptiert und nach dem Wärmeübertrager der Biomasse-Kleinfeuerung angebracht.

Dieses Verbrennungssystem wurde durch umfassende Testläufe mit begleitenden Emissionsmessungen sowie Brennstoff-, Staub- und Ascheanalysen bewertet. Der Einsatz der modellbasierten Regelung führte zu einem stabileren Betrieb bei allen Leistungen und für alle Brennstoffe. Der Elektrofilter zeigte sehr zufriedenstellende Abscheidegrade für alle untersuchten Brennstoffe und Anlagenleistungen. Dadurch konnte die Brennstoffflexibilität der handelsüblichen Biomasse-Kleinfeuerung erhöht und die Verbrennung von Agrarbrennstoffen ermöglicht werden.

 


Scientific Journals | 2019

Real-life emission factor assessment for biomass heating appliances at a field measurement campaign in Styria, Austria

Sturmlechner R, Schmidl C, Carlon E, Reichert G, Stressler H, Klauser F, Kelz J, Schwabl M, Kirchsteiger B, Kasper-Giebl A, Höftberger E, Haslinger W. Real-life emission factor assessment for biomass heating appliances at a field measurement campaign in Styria, Austria. WIT Transactions on Ecology and the Environment 2019.236:221-231

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Biomass combustion is a major contributor to ambient air pollution. Thus, knowing the real-life emissions of biomass heating systems is crucial. Within the project Clean Air by biomass a field measurement campaign was conducted. 15 biomass heating appliances were tested in households at the end user according to their usual operation. Emission factors for gaseous and particulate emissions, as well as for the genotoxic and carcinogenic substance benzo(a)pyrene, were evaluated and compared to current proposed European and Austrian emission factors used for emission inventories. Moreover, the shares of particles and benzo(a)pyrene in hot and cooled flue gas were determined. Results showed a high variability of emissions in the field. Highest values and ranges occurred for room heaters (TSPtotal: 226 mg/MJ). Biomass boilers showed clearly lower emission factors (TSPtotal: 184 mg/MJ) in the field than room heaters and also than the proposed European and Austrian emission factors, in many cases. Emission factors for tiled stoves showed a similar trend (TSPtotal: 67 mg/MJ). The share of condensable particles in the flue gas was remarkable. Especially benzo(a)pyrene was found mostly in the condensable fraction of the particles.


Conference contributions | 2019

Reduction of ash-realted problems in large-scale biomass combustion systems via resource efficient low-cost fuel additives

Sommersacher P, Kienzl N, Retschitzegger S. Reduction of ash-realted problems in large-scale biomass combustion systems via resource efficient low-cost fuel additives. 27th European Biomass Conference & Exhibition (Poster). 2019.

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The incineration of waste wood is very often associated with ash-related problems (deposits, slagging and corrosion). This leads to short maintenance intervals, which result in significant power generation losses and high downtime costs. To avoid these problems, additives can be used, with particularly cost-effective additives being of great interest. Based on pre-evaluations, the addition of 2% gypsum and 3% coal fly ash was recommended, since an improved ash melting behaviour and reduced risk for high-temperature corrosion can be expected with addition of gypsum and coal fly ash. These additives with the recommended mixing rates were then investigated in a large-scale plant. Extensive investigations were carried out without additive (as a reference), and with the additives focusing on dust formation (aerosols and total dust), deposit formation and the corrosion behaviour of superheaters. These investigations were accompanied by fuel and ash analyses (grate, cyclone and filter). The addition of additives increased the amount of total dust in the flue gas up to 195% and 262% for gypsum and coal fly ash respectively. The chemical analysis of the total dust showed an enrichment of refectory species like Al for coal fly ash and Ca and Mg for gypsum which can positively influence the slagging behaviour. Aerosol measurements showed that the addition of coal fly ash minimised the amount of fine particulate matter, as less alkali metals (K and Na) were released into the gas phase. Gypsum addition increases the SO2 concentrations in the gas phase due to the decomposition of gypsum, as in the combustion chamber about 900°C are present. Due to the preferred sulphation reactions (binding of S to alkali metals) less Cl is bound to alkali metals and therefore the Cl concentrations in the aerosols were lower compared to the reference case. This effect was also found in the deposits sampled at the position of the superheater. Based on the chemical composition of deposits the molar 2S/Cl ratios were determined, which can be used to predict the risk for high temperature corrosion. The analysis data showed that an improvement concerning the high temperature corrosion risk is possible by adding coal fly ash, whereas a significant improvement in case of gypsum additions seems very likely. The measurements carried out so far showed the influence (built-up rate, chemical composition etc.) of the additive application on ash fractions, deposits and dusts. By taking a closer look at the change in chemical compositions of dusts and deposits, additives with an appropriate additivation ratio can be suggested. In case of coal fly ash 3% and in case of gypsum 1% additive related to dry fuel seems to be adequate additive ratios to positively influence the risk of high temperature corrosion and reduce the slagging behaviour.


Peer Reviewed Scientific Journals | 2019

Single large wood log conversion in a stove: Experiments and modelling

Anca-Couce A, Caposciutti G, Gruber T, Kelz J, Bauer T, Hochenauer C, Scharler R. Single large wood log conversion in a stove: Experiments and modelling. Renewable Energy 2019.143:890-897.

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Natural draft wood log stoves for residential bioheat production are very popular due to the low fuel costs, the ecological aspect of a renewable energy source and the visual appeal of the flame. However, they have rather high pollutant emissions, specially of unburnt products. The description of large wood logs conversion in stoves needs to be improved to allow a process optimization which can reduce these emissions. The transient conversion of a single wood log in a stove is experimentally investigated with test runs quenching the log after defined time intervals and measuring the flue gas composition and temperatures in the log and stove. The experiments have been described with a volumetric single particle model, which predicts with good accuracy the log conversion until a time of around 30 min, when pyrolysis is almost ending. At that point, log fragmentation takes place and smaller fragments are detached from the log falling onto the bed of embers. Despite the increase in external surface area, char oxidation takes place at a moderate rate. This last stage of wood log conversion in a stove is the most challenging to model. Finally, preliminary recommendations are provided for reducing CO emissions in wood log stoves.


Conference contributions | 2019

Smart Logwood Boiler - A holistic approach for improving the efficiency of residential heating systems. 27th European Biomass Conference & Exhibition.

Zemann C, Deutsch M, Zlabinger S, Hofmeister G, Gölles M, Horn M. Smart Logwood Boiler - A holistic approach for improving the efficiency of residential heating systems. 27th European Biomass Conference & Exhibition. Lisbon. 2019. (Oral presentation, 27.05.2019).

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Conference contributions | 2019

Smart Logwood Boiler – A holistic approach for improving the efficiency of residential heating systems

Zemann C, Deutsch M, Zlabinger S, Hofmeister G, Gölles M, Horn M. Smart Logwood Boiler – A holistic approach for improving the efficiency of residential heating systems. 27th European Biomass Conference & Exhibition (Oral Presentation). May 2019.

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Conference contributions | 2019

Spectroscopic in situ methods for the evaluation of the active centers on ash-layered bed materials from gasification in a fluidized bed reactor

Chlebda D, Aziaba K, Janisch D, Kuba M, Hofbauer H, Łojewska J. Spectroscopic in situ methods for the evaluation of the active centers on ash-layered bed materials from gasification in a fluidized bed reactor. ICPS 2019

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Technical Reports | 2019

Synchronization of the gas production and utilization rates of a solid-to-gas process and a downstream gas-to-X process

Nigitz T, Gölles M, Aichernig C, Hofbauer H, Horn, M. Synchronization of the gas production and utilization rates of a solid-to-gas process and a downstream gas-to-X process. 21. Styrian Workshop on Automatic Control. 10 September 2019. Leitring/Wagna, Austria. (oral presentation)

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Conference contributions | 2019

Technology mapping of market-available small-scale combustion appliances

Feldmeier S, Wopienka E, Schwarz M, Pfeifer C. Technology mapping of market-available small-scale combustion appliances. 27th European Biomass Conference & Exhibition (Poster). 2019.

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A broad range of different biomass combustion appliances dedicated to domestic heating is available on the market. Depending on the technology the impact of varying properties of biomass fuels on slag formation and emission release may vary. Aspects as the design of the grate section and the selection of individual boiler components as well as operational settings determine the applicability of biomass fuels. Apart from fuel properties also the fuel load on the grate, residence time, air distribution and geometry of grate and combustion chamber affect the degree of slag formation and emission release. Technology indexes determined by means of constructional measures enable a systematic comparison and – in a further step – an assessment of combustion appliances. In this work specific technology indexes were specified and applied to compare technological aspects, which will prospectively allow investigating the technological influence on the combustion performance.


Conference contributions | 2019

Thermal Trouble: Challenges in Optimization and Evaluation of Thermal Energy Systems

Lichtenegger K, Unterberger V, Stadler M, Zellinger M, Carreras F, Moser A. Thermal Trouble: Challenges in Optimization and Evaluation of Thermal Energy Systems. IAPE 2019 : International Conference on Innovative Applied Energy (oral presentation). March 2019.

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Conference contributions | 2019

Time-dependent catalytic activation of inactive k-feldspar by layer formation during fluidized bed conversion with residual fuels

Wagner C, Hammerl C, Kuba M, Hofbauer H. Time-dependent catalytic activation of inactive k-feldspar by layer formation during fluidized bed conversion with residual fuels. 27th European Biomass Conference & Exhibition (Poster). May 2019.

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Olivine is currently used as bed material in dual fluidized bed steam gasification due to its catalytic activity towards the water-gas-shift (WGS) reaction and tar reforming. However, olivine contains traces of heavy metals which necessitate an expensive disposal of the accruing ash. The study of alternative bed materials for DFB steam gasification is therefore of major importance. The activity of a bed material is one important factor when classifying its suitability. Several alternative bed materials like quartz and K-feldspar are non-active when fresh but become activated during operation by interaction with the ash by forming layers. The focus of this work was therefore to quantify the initial activation of K-feldspar over the first operational hours as exemplary inactive bed material. Bed material samples from fluidized bed combustion were collected during operation. The fuels used were bark, chicken manure and a bark/chicken manure mixture. The obtained samples were sieved to 200 – 250 µm and tested in a micro-scale test-rig regarding the WGS reaction. A time-dependent activation of K-feldspar was observed marking a first step in better understanding the activation of bed materials.


Conference contributions | 2020

"Long-term verification of a new modular method for CO-lambda-optimisation"

Zemann C, Hammer F, Gölles M. Long-term verification of a new modular method for CO-lambda-optimisation. 6th Central European Biomass Conference CEBC 2020 (Oral Presentation). 2020.

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Peer Reviewed Scientific Journals | 2020

A MILP-based modular energy management system for urban multi-energy systems: Performance and sensitivity analysis

Moser AGC, Muschick D, Gölles M, Nageler PJ, Schranzhofer H, Mach T et al. A MILP-based modular energy management system for urban multi-energy systems: Performance and sensitivity analysis. Applied Energy. 2020;2020(261). 114342.

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The continuous increase of (volatile) renewable energy production and the coupling of different energy sectors such as heating, cooling and electricity have significantly increased the complexity of urban energy systems. Such multi-energy systems (MES) can be operated more efficiently with the aid of optimization-based energy management systems (EMS). However, most existing EMS are tailor-made for one specific system or class of systems, i.e. are not generally applicable. Furthermore, only limited information on the actual savings potential of the usage of an EMS under realistic conditions is available. Therefore, this paper presents a novel modular modeling approach for an EMS for urban MES, which also enables the modeling of complex system configurations. To assess the actual savings potential of the proposed EMS, a comprehensive case study was carried out. In the course of this the influence of different user behavior, changing climatic conditions and forecast errors on the savings potential was analyzed by comparing it with a conventional control strategy. The results showed that using the proposed EMS in conjunction with supplementary system components (thermal energy storage and battery) an annual cost savings potential of between 3 and 6% could be achieved.


Conference contributions | 2020

A modular energy management system for multi-energy systems

Muschick D, Kaisermayer V, Moser A, Gölles M. A modular energy management system for multi-energy systems. 6th Central European Biomass Conference, 22-24 January 2020, Graz.

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