Publications
Conference Papers | 2017
Modellprädiktive Regelung eines solar-und biomassebasierten Fernwärmenetzes
Moser A, Muschick D, Lichtenegger K, Gölles M, Hofer A. Modellprädiktive Regelung eines solar- und biomassebasierten Fernwärmenetzes. Zukunft der Gebäude: digital - dezentral - ökologisch. 23 Nov 2017; Leykam;16:151-159.
The use of renewable-energy-based heat producers within district heating grids is getting more and more popular. In order to benefit from the advantages and compensate for the different disadvantages of the various types of heat producers powered by renewable energy sources like biomass, solar energy or waste heat, a combination of these systems could be favoured over using, for example, only one main biomass-based boiler. Furthermore , in many cases, the additional use of buffer storages is necessary to fully benefit from the use of these kinds of heat producers. A major challenge with such multi-producer heating grids is the cost optimal management of all heat producers and buffer storages. Therefore , a high-level control strategy is necessary, which is able to plan ahead the use of slowly reacting and/or weather dependent heat producers while minimizing operational costs and pollutant emissions. This article shows the development of a linear model predictive controller (MPC) for a district heating grid with several (renewable) decentralized heat producers and heat storages. In order to provide the MPC with the required forecast of the future heat demand, an adaptive load forecasting method has been designed. Additionally, in order to be able to incorporate solar panels, the MPC needs to have a forecast of their possible future heat output. Therefore, a physically motivated solar yield forecasting method has been designed. The required prediction models for the MPC were represented by so-called mixed logical dynamical (MLD) system models. MLD system models combine the modelling power of discrete state system models (finite state machines) and discrete time system models by the extension of the regular linear state-space system model approach with integer and continuous auxiliary variables and linear inequality constraints. The occurrence of both integer and continuous variables within the resulting optimization problem of the MPC leads to a mixed-integer linear program (MILP), which can be solved efficiently using modern MILP solvers. The resulting control strategy is tested in a thermo-hydraulic simulation environment of an actual small-scale multi-producer district heating grid consisting of a medium-scale wood chip boiler with buffer storage, a solar collector with buffer storage and a high temperature heat pump, an oil boiler and 25 heat consumers. Additionally, a state observer was designed and connected with the MPC in order to detect control errors and to incorporate feedback from the heat producers and the buffer storages. The simulations have indicated that the designed MPC and the state observer work properly. Therefore, these elements have been implemented on-site on the actual heating grid, with the first test run scheduled for October 2017.
Modellprädiktive Regelung eines solar-und biomassebasierten Fernwärmenetzes | Request PDF. Available from: https://www.researchgate.net/publication/321314304_Modellpradiktive_Regelung_eines_solar-und_biomassebasierten_Fernwarmenetzes [accessed Feb 21 2018].
Conference Papers | 2017
Nitrogen Assessment in Small Scale Biomass Heating Systems
Enigl M, Strasser C, Hochbichler E, Schmidl C. Nitrogen Assessment in Small Scale Biomass Heating Systems. 25th European Biomass Conference & Exhibition (Poster). June 2017, Stockholm, Sweden.
Conference Papers | 2017
Novel concepts for CO2 utilisation to produce value added products
Sonnleitner A, Dißauer C, Martini S, Drosg B, Meixner K, Rachbauer L, Lazarova Z, Herwig C, Kinger G, Kofler I, Strasser C. Novel concepts for CO2 utilisation to produce value added products. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
Peer Reviewed Scientific Journals | 2017
Optimisation of continuous gas fermentation by immobilisation of acetate-producing Acetobacterium woodi
Steger, F, Rachbauer L, Windhagauer M, Montgomery LFR, Bochmann G. Optimisation of continuous gas fermentation by immobilisation of acetate-producing Acetobacterium woodi. Anaerobe. August 2017;46: 96-103
Other Publications | 2017
Optimisation of continuous gas fermentation by immobilisation of acetate-producing Acetobacterium woodii.
Steger, F, Rachbauer L, Windhagauer M, Montgomery LFR, Bochmann G. Optimisation of continuous gas fermentation by immobilisation of acetate-producing Acetobacterium woodii. Anaerobe. Available online 22 June 2017
Conference Papers | 2017
Optimisation of the post-consumer and demolition wood supply and value chain
Dißauer C, Kienzl N, Kunter A, Meirhofer M, Pointner C, Schwarzbauer P, Sommersacher P, Strasser C, Wellacher M. Optimisation of the post-consumer and demolition wood supply and value chain. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
Peer Reviewed Scientific Journals | 2017
Overcoming the bottlenecks of anaerobic digestion of olive mill solid waste by two-stage fermentation
Stoyanova E, Lundaa T, Bochmann G, Fuchs W. Overcoming the bottlenecks of anaerobic digestion of olive mill solid waste by two-stage fermentation. Environmental Technology (United Kingdom). 16 February 2017;38(4): 394-405.
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 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.
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 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 | 2017
Production of Fuel Ethanol and Higher Alcohols from Biomass Residue
Summers M, Liao C, Hoffman M, Hart M, Seiser R, Neimann U, Cattolica R, Rauch R, Binder M. Production of Fuel Ethanol and Higher Alcohols from Biomass Residue. 25th European Biomass Conference & Exhibition (oral presentation). June 2017, Stockholm, Sweden.
Peer Reviewed Scientific Journals | 2017
Pyrolysis of pellets made with biomass and glycerol: Kinetic analysis and evolved gas analysis
Bartocci P, Anca-Couce A, Slopiecka K, Nefkens S, Evic N, Retschitzegger S, Barbanera M, Buratti C, Cotana F, Bidini G, Fantozzi F. Pyrolysis of pellets made with biomass and glycerol: Kinetic analysis and evolved gas analysis. Biomass and Bioenergy. February 2017;97: 11-19.
Glycerol is a co-product compound of biodiesel production with an interesting heating value. In this work pyrolysis kinetic parameters for a pellet made with a mass fraction of 90% sawdust and a mass fraction of 10% glycerol are derived through thermogravimetric analysis. A new parallel reaction scheme with four components (cellulose, hemicellulose, lignin and glycerol) is adopted and the kinetic triplet for each component is derived using a model fitting approach applied to this particular kind of pellet. The isoconversional method Kissinger-Akahira-Sunose is employed both to provide initial values for model fitting simulations and to check final results. Results show that activation energies and pre-exponential factors are respectively: 149.7 kJ mol−1 and 1.98*1011 s−1 for hemicellulose, 230.1 kJ mol−1 and 1.84*1017 s−1 for cellulose, 154.3 kJ mol−1 and 5.14*109 s−1 for lignin, 74.5 kJ mol−1 and 2.17*105 s−1 for glycerol with a first reaction order for all components, except for lignin (n = 2.6). Through evolved gas analysis it was demonstrated that the thermal degradation of glycerol contained in the pellet can increase hydrogen content in pyrolysis gases.
Conference Papers | 2017
Pyrolysis of sewage sludge to produce fuels and chemical feedstock
Wartha C, Kranner R, Meirhofer M. Pyrolysis of sewage sludge to produce fuels and chemical feedstock. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
Contributions to trade journals | 2017
Rural electrification and capacity expansion with an integrated modeling approach
Hartvigsson E, Stadler M, Cardoso G. Rural electrification and capacity expansion with an integrated modeling approach. Renewable Energy by Elsevier. 2017.
Peer Reviewed Scientific Journals | 2017
Sorghum, a sustainable feedstock for biogas production? Impact of climate, variety and harvesting time on maturity and biomass yield
Wannasek L Ortner M Amon B Amon T. Sorghum, a sustainable feedstock for biogas production? Impact of climate, variety and harvesting time on maturity and biomass yield. BIOMASS BIOENERG. 2017; 106: 137-145
Contributions to trade journals | 2017
Startups in Kalifornien – Kollaborationsmodell im Energiebereich
Stadler M., Temper M., Haslinger W. Startups in Kalifornien – Kollaborationsmodell im Energiebereich. Impulsreferat Energy.Inc.Ubator, Start-ups als Katalysator in F&E für marktfähige Energiesystemlösungen. Co-Creation-Workshop. Bundesministerium für Verkehr, Innovation und Technologie. Österreich, 22. September 2017.
Conference Papers | 2017
State of the art dual fluidized bed gasification of biomass in industrial scale
Kuba M, Kirnbauer F, Hofbauer H. State of the art dual fluidized bed gasification of biomass in industrial scale. 5th Central European Biomass Conference (oral presentation). January 2017, Graz, Austria.
Peer Reviewed Scientific Journals | 2017
Techno-economic assessment of hydrogen production based on dual fluidized bed biomass steam gasification, biogas steam reforming, and alkaline water electrolysis processes
Yao J, Kraussler M, Benedikt F, Hofbauer H. Techno-economic assessment of hydrogen production based on dual fluidized bed biomass steam gasification, biogas steam reforming, and alkaline water electrolysis processes. Energy Conversion and Management. 1 August 2017;145: 278-292.
Conference contributions | 2017
The Green Parking Area – Utilization of urban parking areas for cultivation of microalgae
Zellinger M, Riepl R, Lichtenegger K, Meixner K, Drosg B, Enigl M, Theuretzbacher F, Schipfer F. The Green Parking Area – Utilization of urban parking areas for cultivation of microalgae. Presentation at the Eco City Summit 2017, Melbourne, Australia, 17. June 2017.
Other Presentations | 2017
The Green Parking Space – Nutzung von städtischen Verkehrsflächen für die Produktion von Biomasse
Schipfer F, Lichtenegger K, Zellinger M et al. The Green Parking Space – Nutzung von städtischen Verkehrsflächen für die Produktion von Biomasse. Präsentation. First Vienna Vertical Farming Meetup 01.03.2017, Wien.
Conference Papers | 2017
Upscaling and Operation of a Biomass Derived Fischer-Tropsch Pilot Plant Producing 1 Barrel Per Day
Loipersböck J, Weber G, Rauch R, Gruber H, Groß P, Hofbauer H. Upscaling and Operation of a Biomass Derived Fischer-Tropsch Pilot Plant Producing 1 Barrel Per Day. 25th European Biomass Conference & Exhibition (oral presentation). June 2017, Stockholm, Sweden.
Conference Papers | 2017
Wasserstoff aus Biomasse - Stand der Technik und Perspektiven
Hofbauer H, Bosch K, Kraussler M. Wasserstoff aus Biomasse - Stand der Technik und Perspektiven. 5th Central European Biomass Conference (oral presentation). January 2017, Graz, Austria.
Peer Reviewed Scientific Journals | 2016
2250-h long term operation of a water gas shift pilot plant processing tar-rich product gas from an industrial scale dual fluidized bed biomass steam gasification plant
Kraussler M, Binder M, Hofbauer H. 2250-h long term operation of a water gas shift pilot plant processing tar-rich product gas from an industrial scale dual fluidized bed biomass steam gasification plant. International Journal of Hydrogen Energy. 27 April 2016;41(15): 6247-6258.
Peer Reviewed Scientific Journals | 2016
Adsorptive Desulfurization: Fast On-Board Regeneration and the Influence of Fatty Acid Methyl Ester on Desulfurization and in Situ Regeneration Performance of a Silver-Based Adsorbent
Neubauer R, Weinlaender C, Kienzl N, Schroettner H, Hochenauer C. Adsorptive Desulfurization: Fast On-Board Regeneration and the Influence of Fatty Acid Methyl Ester on Desulfurization and in Situ Regeneration Performance of a Silver-Based Adsorbent. Energy and Fuels. 16 June 2016;30(6): 5174-5182.
Adsorptive on-board desulfurization units require a high desulfurization and regeneration performance for a wide range of fuels to keep them small and ensure long maintenance intervals. A novel thermal regeneration strategy was investigated in this work, fulfilling all requirements for in situ on-board regeneration. In this strategy, a temperature-controlled flow rate (TCFR) of air was used to control the temperature inside the adsorber. With this dynamic approach, the regeneration time was reduced significantly in comparison to other thermal regeneration strategies. The novel regeneration strategy was tested using Ag–Al2O3 as an adsorbent to desulfurize a benzothiophen (BT)-enriched road diesel (300 ppmw of total sulfur). A commercial diesel containing fatty acid methyl ester (FAME) was used to evaluate the fuel flexibility regarding desulfurization and regeneration performance. In the case of 6.63 wt % FAME and 300 ppmw of sulfur, the breakthrough adsorption capacity of sulfur decreased from 1.04 to 0.17 mg/g. In TCFR regeneration experiments, the breakthrough adsorption capacity was restored to over 94% in the case of both fuels. Thereby, the Brunauer–Emmett–Teller (BET) surface area of the regenerated adsorbent decreased by only 1.5%, and negligible carbon deposits were detected.