Peer-reviewed publications | 2013
Overview of Forestry and Wood Fuel Supply Chains in Austria; Investment Costs and Profitability of Biomass Heating Plants in Austria; Business Models from Austria Covering the Entire Wood Heat Supply Chain
Otepka P, Kristöfel C, Strasser C, et al. Guidebook on Local Bioenergy Supply Based on Woody Biomass. Overview of Forestry and Wood Fuel Supply Chains in Austria; Investment Costs and Profitability of Biomass Heating Plants in Austria; Business Models from Austria Covering the Entire Wood Heat Supply Chain. ISBN 978-1-938681-98-1. 2013:2-36;57-112.
Conference contributions | 2016
Overview on advanced biofuels technologies
Bacovsky D. Overview on advanced biofuels technologies. Bioenergy Australia 2016. November 2016, Brisbane, Australia.
Conference contributions | 2015
Parameter Study with Sulfidized Molybdenum Catalyst for Mixed Alcohol Synthesis with Biomass-Derived Synthesis Gas
Weber G, Rauch R, Hofbauer H. Parameter Study with Sulfidized Molybdenum Catalyst for Mixed Alcohol Synthesis with Biomass-Derived Synthesis Gas, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
Peer Reviewed Scientific Journals | 2017
Particulate emissions from modern and old technology wood combustion induce distinct time-dependent patterns of toxicological responses in vitro.
Happo MS, Hirvonen MR, Uski O, Kasurinen S, Kelz J, Brunner T, Obernberger I, Jalava PI. Particulate emissions from modern and old technology wood combustion induce distinct time-dependent patterns of toxicological responses in vitro. Toxicology in Vitro. Volume 44, October 2017, Pages 164-171
Toxicology in Vitro.
Toxicological characterisation of combustion emissions in vitro are often conducted with macrophage cell lines, and the majority of these experiments are based on responses measured at 24 h after the exposure. The aim of this study was to investigate how significant role time course plays on toxicological endpoints that are commonly measured in vitro. The RAW264.7 macrophage cell line was exposed to PM1 samples (150 μg/ml) from biomass combustion devices representing old and modern combustion technologies for 2, 4, 8, 12, 24 and 32 h. After the exposure, cellular metabolic activity, cell membrane integrity, cellular DNA content, DNA damage and production of inflammatory markers were assessed. The present study revealed major differences in the time courses of the responses, statistical differences between the studied samples mostly limiting to differences between modern and old technology samples. Early stage responses consisted of disturbances in metabolic activity and cell membrane integrity. Middle time points revealed increases in chemokine production, whereas late-phase responses exhibited mostly increased DNA-damage, decreased membrane integrity and apoptotic activity. Altogether, these results implicate that the time point of measurement has to be considered carefully, when the toxicity of emission particles is characterised in in vitro study set-ups.
Conference contributions | 2012
Particulate matter emissions from small-scale biomass combustion systems – characterisation and primary measures for emission reduction
Brunner T. Particulate matter emissions from small-scale biomass combustion systems – characterisation and primary measures for emission reduction, IEA Bioenergy Conference 2012, 13th-15th of November 2012, Vienna, Austria.
Other Presentations | 2014
Pellet off-gassing during storage: The impact of storage conditions and type of source material
Meier, F. Pellet off-gassing during storage: The impact of storage conditions and type of source material, Master Thesis, University of Natural Resources and Life Sciences Vienna, Vienna, Austria, 2014.
Contributions to trade journals | 2008
Pelletfeuerungen mit thermoelektrischer Stromerzeugung
Friedl G, Moser W, Griesmayr S. Pelletfeuerungen mit thermoelektrischer Stromerzeugung, 10. Holzenergiesymposium 2008, 12th of September, Zürich, Swiss.
Contributions to trade journals | 2013
Performance improvement of dual fluidized bed gasifiers by temperature reduction: The behavior of tar species in the product gas
Kirnbauer F, Wilk V, Hofbauer H. Performance improvement of dual fluidized bed gasifiers by temperature reduction: The behavior of tar species in the product gas. Fuel. 2013;108:534-42.
To meet the aims of the worldwide effort to reduce greenhouse gas emissions, product gas from biomass steam gasification in DFB (dual fluidized bed) gasification plants can play an important role for the production of electricity, fuel for transportation and chemicals. Using a catalytically active bed material, such as olivine, brings advantages concerning tar reduction in the product gas. Experience from industrial scale gasification plants showed that a modification of the olivine occurs during operation due to the interaction of the bed material with ash components from the biomass and additives. This interaction leads to a calcium-rich layer on the bed material particles which influences the gasification properties and reduces tar concentration in the product gas. In this paper, the influence on the gasification performance, product gas composition and tar formation of a reduction of the gasification temperature are studied. A variation of the gasification temperature from 870 °C to 750 °C was carried out in a 100 kW pilot plant. A reduction of the gasification temperature down to 750 °C reduces the concentration of hydrogen and carbon monoxide in the product gas and increases the concentration of carbon dioxide and methane. The product gas volume produced per kg of fuel is reduced at lower gasification temperatures but the calorific value of the product gas increases. The volumetric concentration of tars in the product gas increases slightly until 800 °C and nearly doubles when decreasing the gasification temperature to 750 °C. The tars detected by gas chromatography-mass spectrometry (GCMS) were classified into substance groups and related to the fuel input to the gasifier and showed a decrease in naphthalenes and polycyclic aromatic hydrocarbons (PAHs) and an increase in phenols, aromatic compounds and furans when reducing the gasification temperature. The comparison with results from an earlier study, where the gasification properties of unused fresh olivine were compared with used olivine, underlines the importance of a long retention time of the bed material in the gasifier, ensuring the formation of a calcium-rich layer in the bed material. © 2012 Elsevier Ltd. All rights reserved.
Conference contributions | 2018
Performance improvement of model-based control strategies in large-scale solar plants and its implementation details
Innerhofer P, Unterberger V, Luidolt P, Lichtenegger K, Gölles M. Performance improvement of model-based control strategies in large-scale solar plants and its implementation details. 5th International Solar District Heating Conference SDH. Graz, Austria: 2018.
Conference Papers | 2017
Performance of a mixed alcohol synthesis lab-scale process chain operated with wood gas from dual fluidized bed biomass steam gasification
Binder M, Weber G, Rauch R, Hofbauer H. Performance of a mixed alcohol synthesis lab-scale process chain operated with wood gas from dual fluidized bed biomass steam gasification. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
Contributions to trade journals | 2013
Performance of a pellet boiler fired with agricultural fuels
Carvalho L, Wopienka E, Pointner C, Lundgren J, Verma VK, Haslinger W, et al. Performance of a pellet boiler fired with agricultural fuels. Appl Energy. 2013;104:286-96.
The increasing demand for woody biomass increases the price of this limited resource, motivating the growing interest in using woody materials of lower quality as well as non-woody biomass fuels for heat production in Europe. The challenges in using non-woody biomass as fuels are related to the variability of the chemical composition and in certain fuel properties that may induce problems during combustion. The objective of this work has been to evaluate the technical and environmental performance of a 15. kW pellet boiler when operated with different pelletized biomass fuels, namely straw (Triticum aestivum), Miscanthus (Miscanthus× giganteus), maize (Zea mays), wheat bran, vineyard pruning (from Vitis vinifera), hay, Sorghum (Sorghum bicolor) and wood (from Picea abies) with 5% rye flour. The gaseous and dust emissions as well as the boiler efficiency were investigated and compared with the legal requirements defined in the FprEN 303-5 (final draft of the European standard 303-5). It was found that the boiler control should be improved to better adapt the combustion conditions to the different properties of the agricultural fuels. Additionally, there is a need for a frequent cleaning of the heat exchangers in boilers operated with agricultural fuels to avoid efficiency drops after short term operation. All the agricultural fuels satisfied the legal requirements defined in the FprEN 303-5, with the exception of dust emissions during combustion of straw and Sorghum. Miscanthus and vineyard pruning were the best fuels tested showing comparable emission values to wood combustion. © 2012 Elsevier Ltd.
Peer Reviewed Scientific Journals | 2015
Performance of a water gas shift pilot plant processing product gas from an industrial scale biomass steam gasification plant
Kraussler M, Binder M, Fail S, Bosch K, Hackel M, Hofbauer H. Performance of a water gas shift pilot plant processing product gas from an industrial scale biomass steam gasification plant. Biomass and Bioenergy. 4 August 2015;89:50-57.
In this paper, the performance of a commercial Fe/Cr based catalyst for the water gas shift reaction was investigated. The catalyst was used in a water gas shift pilot plant which processed real product gas from a commercial biomass steam gasification plant with two different qualities: extracted before and extracted after scrubbing with a rapeseed methyl ester gas scrubber. The performance of the WGS pilot plant regarding these two different gas qualities was investigated. For this reason, extensive chemical analyses were carried out. CO, CO2, CH4, N2, O2, C2H6, C2H4, and C2H2 and H2S, COS, and C4H4 S were measured. In addition, GCMS tar and NH3 analyses were performed. Furthermore, the catalyst's activity was observed by measuring the temperature profiles along the reactors of the water gas shift pilot plant. During the 200 h of operation with both product gas qualities, no catalyst deactivation could be observed. A CO conversion up to 93% as well as a GCMS tar reduction (about 28%) along the water gas shift pilot plant was obtained. Furthermore, a specific H2 production of 63 g H2 per kg biomass (dry and ash free) was reached with both product gas qualities. No significant performance difference could be observed.
Conference Papers | 2015
Performance of a water gas shift pilot plant processing tar-rich product gas from a commercial biomass steam gasification plant operating at partial load conditions
Kraussler M, Binder M, Hofbauer H. Performance of a water gas shift pilot plant processing tar-rich product gas from a commercial biomass steam gasification plant operating at partial load conditions. International Bioenergy Exhibition and Asian Bioenergy Conference 2015. October 2015, Shanghai, China.
Conference Papers | 2015
Performance of a Water Gas Shift Unit Processing Product Gas from Biomass Steam Gasification
Kraussler M, Binder M, Fail S, Rauch R, Bosch K, Hackel M, Hofbauer H. Performance of a Water Gas Shift Unit Processing Product Gas from Biomass Steam Gasification. 23rd European Biomass Conference & Exhibition (oral presentation). June 2015, Vienna, Austria.
Reviewed Conference Papers | 2017
Performance of a water gas shift unit processing tar-rich product gas from a commercial dual fluidized bed biomass steam gasification plant which operates at partial load
Kraussler M, Binder M, Hofbauer H. Performance of a water gas shift unit processing tar-rich product gas from a commercial dual fluidized bed biomass steam gasification plant which operates at partial load. International Journal of Oil, Gas and Coal Technology. 2017;14(1-2): 32-48.
In this paper, the performance of a water gas shift unit processing product gas from a commercial dual fluidised bed biomass steam gasification plant is studied. The experiments were carried out during a partial load operation of the gasification plant. In order to investigate a water gas shift process, a water gas shift unit, located at the site of the gasification plant in Oberwart, Austria, was used. The water gas shift unit consisted of three reactors in series filled with a commercial Fe'Cr-based catalyst and was operated with tar-rich product gas. No performance decrease of the water gas shift unit was observed during the partial load operation of the gasification plant. Furthermore, a CO conversion of 92% and a GCMS tar reduction of about 30% were reached. In addition, it was found that partial load operation of the gasification plant did not negatively affect the performance of the water gas shift unit.
Conference contributions | 2014
Performances of a non-sulfided CoMo/SiO2-Al2O3 hydrocracking catalyst used in BtL Technology
Sauciuc A, Ganea R, Dumitrescu L, Rauch R, Hofbauer H. Performances of a non-sulfided CoMo/SiO2-Al2O3 hydrocracking catalyst used in BtL Technology, 4th International Symposium on Gasification and its Applications (iSGA-4) 2014, 2nd-5th of September 2014, Vienna, Austria.
Conference Papers | 2016
Phase Sewparation Behaviour of FAME and Water
Bardolf R, Thoma C, Bosch K, Rauch R, Hofbauer H. Phase Sewparation Behaviour of FAME and Water. 24th European Biomass Conference & Exhibition (poster). June 2016, Amsterdam, Netherlands.
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.
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.
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 | 2010
PM emissions from old and modern biomass combustion systems and their health effects
Kelz J, Brunner T, Obernberger I, Hirvonen M, Javala P. PM emissions from old and modern biomass combustion systems and their health effects, 18th European Biomass Conference and Exhibition 2010, 3rd-7th of May 2010, Lyon, France. p 1231-1243.
Conference Papers | 2017
Polygeneration of hydrogen and a gas mixture composed of H2 and CH4 via sorption enhanced reforming of biomass
Kraussler M, Priscak J, Benedikt F, Hofbauer H. Polygeneration of hydrogen and a gas mixture composed of H2 and CH4 via sorption enhanced reforming of biomass. 25th European Biomass Conference & Exhibition (oral presentation). June 2017, Stockholm, Sweden.
Conference contributions | 2009
Possibilities of Ash Utilisation from Biomass Combustion Plants
Obernberger I, Supancic K. Possibilities of Ash Utilisation from Biomass Combustion Plants, 17th European Biomass Conference 2009, 29th of June-3rd of July 2009, Hamburg, Germany. p 2373-2384.
Conference Papers | 2016
Possibility of industrial scale BioH2 production from product gas in existing dual fluidized bed biomass gasification plant
Jovanovic A, Stamenkovic M, Nenning L, Rauch R. Possibility of industrial scale BioH2 production from product gas in existing dual fluidized bed biomass gasification plant. 4th International Symposium on Environment Friendly Energies and Applications, EFEA 2016. 18 November 2016, Belgrade, Serbia.
Conceptual solution of production of pure renewable hydrogen from wood gas or product derived from the commercial biomass steam gasification plant Güssing, Austria was carried out. The proposed process of product gas upgrading consisted of tree basic operations: (I) catalyzed water-gas shift (WGS) reaction, (II) gas drying and cleaning in a wet scrubber and (III) hydrogen purification by pressure swing adsorption. The tail gas or adsorbate can be used like fuel for gas engine for electrical energy production or like a boiler fuel for hot water-heat production.
Scientific Journals | 2018
Power to fuels: Dynamic modeling of a Slurry Bubble Column Reactor in lab-scale for Fischer Tropsch synthesis under variable load of synthesis gas
Seyednejadian S, Rauch R, Bensaid S, Hofbauer H, Weber G, Saracco G. Power to fuels: Dynamic modeling of a Slurry Bubble Column Reactor in lab-scale for Fischer Tropsch synthesis under variable load of synthesis gas. Apllied Sciences. 2018, 8(4): 514.
This research developed a comprehensive computer model for a lab-scale Slurry Bubble Column Reactor (SBCR) (0.1 m Dt and 2.5 m height) for Fischer–Tropsch (FT) synthesis under flexible operation of synthesis gas load flow rates. The variable loads of synthesis gas are set at 3.5, 5, 7.5 m3/h based on laboratory adjustments at three different operating temperatures (483, 493 and 503 K). A set of Partial Differential Equations (PDEs) in the form of mass transfer and chemical reaction are successfully coupled to predict the behavior of all the FT components in two phases (gas and liquid) over the reactor bed. In the gas phase, a single-bubble-class-diameter (SBCD) is adopted and the reduction of superficial gas velocity through the reactor length is incorporated into the model by the overall mass balance. Anderson Schulz Flory distribution is employed for reaction kinetics. The modeling results are in good agreement with experimental data. The results of dynamic modeling show that the steady state condition is attained within 10 min from start-up. Furthermore, they show that step-wise syngas flow rate does not have a detrimental influence on FT product selectivity and the dynamic modeling of the slurry reactor responds quite well to the load change conditions.
Conference contributions | 2012
Prediction of biomass ash melting behaviour – correlation between the data obtained from thermodynamic equilibrium calculations and simultaneous thermal analysis (STA)
Evic N, Brunner T, Oberberger I. Prediction of biomass ash melting behaviour – correlation between the data obtained from thermodynamic equilibrium calculations and simultaneous thermal analysis (STA), 20th European Biomass Conference 2012, 18th-22nd of June 2012, Milano, Italy. p 807-813.