Publikationen
Other Publications | 2015
Survey of modern pellet boilers in Austria and Germany - System design and customer satisfaction of residential installations
Büchner D, Schraube C, Carlon E, von Sonntag J, Schwarz M, Verma VK, Ortwein A. Survey of modern pellet boilers in Austria and Germany - System design and customer satisfaction of residential installations. Applied Energy;160: 390-403.
External Link Details AbstractThe variety of available technical building equipment leads to increasingly complex heating systems with various requirements for efficient operation. Furthermore, in existing buildings the heating system is often historically evolved and contains parts having different ages. Those systems have limited capacity to suit the requirements of replaced components. This paper investigates the operational behavior of small-scale pellet heating systems in Austria and Germany, considering installations in new buildings and boiler replacements in existing buildings and how they are influencing the customer satisfaction.
This investigation was carried out by means of a comprehensive survey for residential customers using pellet fired heating systems. More than 2500 questionnaires were distributed between 2011 and 2013 in Austria, Germany, Greece, Spain and the United Kingdom. In total 293 returned questionnaires were evaluated. The efficiency of the monitored heating systems was estimated using surveyed boiler parameters. Successively, the influence of different operational parameters on the boilers efficiency was evaluated with a statistical analysis, using Pearson correlation coefficient and Spearman correlation.
Results showed that the correct installation of the monitored pellet heating system is easier for new buildings compared to the replacement of old fossil boilers in existing buildings. Optimal operating conditions are characterized by less frequent ignitions and by higher operational loads. Pellet systems operated with a high efficiency in both building types, but for new buildings it is more likely to occur. More than 87% of the participating customers stated that they are highly satisfied with their pellet boiler.
Peer reviewed papers | 2015
The behavior of biomass and char particles in a dual fluidized bed gasification system
Kraft S, Kuba M, Hofbauer H. The behavior of biomass and char particles in a dual fluidized bed gasification system. Powder Technology 2018;338:887-897.
External Link Details AbstractConference presentations and posters | 2015
The Influence of Wood Pellet Prices on Heat Generation Costs of Alternative Heating Systems
Kristöfel C, Strasser C, Schmid E. The Influence of Wood Pellet Prices on Heat Generation Costs of Alternative Heating Systems, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
DetailsOther papers | 2015
The role of 1H-indene in product gas of biomass gasification
Kuba M, Kirnbauer F, Hofbauer H. The role of 1H-indene in product gas of biomass gasification. International Bioenergy Exhibition and Asian Bioenergy Conference 2015. October 2015, Shanghai, China.
DetailsPeer reviewed papers | 2015
The Role of Leak Air in a Double-Wall Chimney
Lichtenegger K, Hebenstreit B, Pointner C, Schmidl C, Höftberger E. The role of leak air in a double-wall chimney. Heat Mass Transfer. 2015;51(6):787-94.
External Link Details AbstractIn modern buildings with tight shells, often room-independent air supply is required for proper operation of biomass stoves. One possibility to arrange this supply is to use a double-wall chimney with flue gas leaving through the pipe and fresh air entering through the annular gap. A one-dimensional quasi-static model based on balance equations has been developed and compared with experimental data. Inclusion of leak air is crucial for reproduction of the experimental results. © 2014, Springer-Verlag Berlin Heidelberg.
Conference presentations and posters | 2015
Time-resolved characterization of PM10 emissions from modern small scale biomass combustion units, including PAHs
Kistler M, Schmidl C, Cetintas EC, Padouvas E, Bauer H, Puxbaum H, Kasper-Giebl A. Time-resolved characterization of PM10 emissions from modern small scale biomass combustion units, including PAHs, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (visual presentation)
DetailsPeer reviewed papers | 2015
Use of Hazelnut's Pruning to Produce Biochar by Gasifier Small Scale Plant
Colantoni A, Longo L, Evic N, Gallucci F, Delfanti L. Use of Hazelnut‟s Pruning to Produce Biochar by Gasifier Small Scale Plant. International Journal of Renewable Energy Research. 2015;5(3):873-878.
External Link Details AbstractBiochar is the product of biomass pyrolysis and gasification. One of the possible application of this product is certainly in agronomic sector, as soil amendment. However biochar use in Italy is subordinated to insert this product in fertilizer list, which biochar could be commercialized with. The aim of this paper is to know the biochar from gasification process (using an Imbert downdraft prototype), in particular investigating its potentiality as soil amendment in terms of European and Italian regulations and in terms of physical and chemical characterizations.
Other papers | 2015
Validation of a Kinetic Model for the Catalyzed Water Gas Shift Reaction Applying a Fe/Cr Catalyst Processing Wood Gas from Biomass Steam Gasification
Kraussler M, Fail S, Plaza Quevedo A, Cortes Guerro JA, Rauch R, Hofbauer H. Validation of a Kinetic Model for the Catalyzed Water Gas Shift Reaction Applying a Fe/Cr Catalyst Processing Wood Gas from Biomass Steam Gasification. 23rd European Biomass Conference & Exhibition (Poster). June 2015, Vienna, Austria.
DetailsPeer reviewed papers | 2015
Ventilation of Carbon Monoxide from a Biomass Pellet Storage Tank - A Study of the Effects of Variation of Temperature and Cross-Ventilation on the Efficiency of Natural Ventilation
Emhofer W, Lichtenegger K, Haslinger W, Hofbauer H, Schmutzer-Roseneder I, Aigenbauer S, et al. Ventilation of carbon monoxide from a biomass pellet storage tank - A study of the effects of variation of temperature and cross-ventilation on the efficiency of natural ventilation. Ann Occup Hyg. 2015;59(1):79-90.
External Link Details AbstractWood pellets have been reported to emit toxic gaseous emissions during transport and storage. Carbon monoxide (CO) emission, due to the high toxicity of the gas and the possibility of it being present at high levels, is the most imminent threat to be considered before entering a pellet storage facility. For small-scale (<30 tons storage capacity) residential pellet storage facilities, ventilation, preferably natural ventilation utilizing already existing openings, has become the most favored solution to overcome the problem of high CO concentrations. However, there is little knowledge on the ventilation rates that can be reached and thus on the effectiveness of such measures. The aim of the study was to investigate ventilation rates for a specific small-scale pellet storage system depending on characteristic temperature differences. Furthermore, the influence of the implementation of a chimney and the influence of cross-ventilation on the ventilation rates were investigated. The air exchange rates observed in the experiments ranged between close to zero and up to 8 m3h-1, depending largely on the existing temperature differences and the existence of cross-ventilation. The results demonstrate that implementing natural ventilation is a possible measure to enhance safety from CO emissions, but not one without limitations. © 2014 © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.
Peer reviewed papers | 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.
External Link DetailsPeer reviewed papers | 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.
External Link Details AbstractAdsorptive 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.
Other Publications | 2016
Air pollution reduction due to the adoption of high efficiency small scale pellet boilers characterized by low emissions
Chiesa M, Monteleone B, Venuta ML, Maffeis G, Greco S, Cherubini A, Schmidl C, Finco A, Gerosa G, Ballarin Denti A. Air pollution reduction due to the adoption of high efficiency small scale pellet boilers characterized by low emissions. Biomass and Bioenergy. 1 July 2016;90: 262-272.
External Link DetailsOther papers | 2016
An investigation on the behavior of impurities over a water gas shift stage using biomass derived syngas for hydrogen production
Loipersböck J, Lenzi M, Rauch R, Hofbauer H. An investigation on the behavior of impurities over a water gas shift stage using biomass derived syngas for hydrogen production. iSGA 2016 - 5th International Symposium on Gasification and its Applications (invited lecture). November/December 2016, Busan, Korea.
DetailsOther Publications | 2016
Analisi del ciclo di vita di caldaie a pellet di bassa potenza caratterizzate da alta efficienza e ridotte emissioni
Monteleone B, Chiesa M, Marzuoli R, Verma VK, Schwarz M, Carlon E, Schmidl C, Ballarin Denti A. Analisi del ciclo di vita di caldaie a pellet di bassa potenza caratterizzate da alta efficienza e ridotte emissioni. Agriforenergy. February 2016.
External Link DetailsPeer reviewed papers | 2016
Analysis of optimization potential in commercial biomass gasification plants using process simulation
Wilk V, Hofbauer H. Analysis of optimization potential in commercial biomass gasification plants using process simulation. Fuel Processing Technology. 01 December 2016;141: 138-147.
DetailsPeer reviewed papers | 2016
Apparent kinetics of the catalyzed water-gas shift reaction in synthetic wood gas
Plaza A, Fail S, Cortés JA, Föttinger K, Diaz N, Rauch R, Hofbauer H. Apparent kinetics of the catalyzed water-gas shift reaction in synthetic wood gas. Chemical Engineering Journal. 1 October 2016;301: 222-228.
External Link DetailsPeer reviewed papers | 2016
Associated effects of storage and mechanical pre-treatments of microalgae biomass on biomethane yields in anaerobic digestion
Gruber-Brunhumer MR, Jerney J, Zohar E, Nussbaumer M, Hieger C, Bromberger P, Bochmann G, Jirsa F, Schagerl M, Obbard JP, Fuchs W, Drosg B. Associated effects of storage and mechanical pre-treatments of microalgae biomass on biomethane yields in anaerobic digestion. Biomass and Bioenergy. October 2016;93: 259-268.
External Link DetailsReports | 2016
Austria – Biofuels Technology, Research and Development
Bacovsky D, Sonnleitner A. Austria – Biofuels Technology, Research and Development. IEA Bioenergy Task 39 Newsletter. December 2016.
DetailsOther Publications | 2016
beReal - Comparative assessment of EN standard test methods and new real-life test methods for biomass room heating appliances
Schmidl C, Reichert G, Schwabl M, Stressler H, Sturmlechner R, Haslinger W. beReal - Comparative assessment of EN standard test methods and new real-life test methods for biomass room heating appliances. 24th European Biomass Conference & Exhibition (poster). June 2016, Amsterdam, Netherlands.
DetailsOther Publications | 2016
beReal - Development of a New Test Method for Firewood Roomheaters Reflecting Real Life Operation
Reichert G, Hartmann H, Haslinger W, Oehler H, Schmidl C, Schwabl M, Stressler H, Sturmlechner R, Woehler M. beReal - Development of a New Test Method for Firewood Roomheaters Reflecting Real Life Operation. 24th European Biomass Conference & Exhibition (poster). June 2016, Amsterdam, Netherlands.
DetailsOther Publications | 2016
Bidirektionale Einbindung dezentraler Einspeiser in Wärmenetze: hydraulische, wärmetechnische und regelungstechnische Aspekte
LichteneggerK, Muschick D, Gölles M, Höftberger E, Leitner A, Wöss D, Reiterer D. Bidirektionale Einbindung dezentraler Einspeiser in Wärmenetze: hydraulische, wärmetechnische und regelungstechnische Aspekte. Vortrag auf der Fachtagung Wärmenetze der Zukunft (2016 in Salzburg).
External Link DetailsReports | 2016
Biofuels in transport
Bacovsky D. Biofuels in transport. WPC Guide to Biofuels. September 2016.
DetailsPeer reviewed papers | 2016
Biological biogas upgrading capacity of a hydrogenotrophic community in a trickle-bed reactor
Rachbauer L, Voitl G, Bochmann G, Fuchs W. Biological biogas upgrading capacity of a hydrogenotrophic community in a trickle-bed reactor. Applied Energy. 15 October 2016;180: 483-490.
External Link DetailsPeer reviewed papers | 2016
Biomass-Based Heating and Hot Water Supply Systems for Prefabricated, High Energy Performance Houses: a Comparison of System Configurations and Control Strategies
Carlon E, Schwarz M, Prada A, Verma V, Baratieri M, Gasparella A, Schmidl C. Biomass-Based Heating and Hot Water Supply Systems for Prefabricated, High Energy Performance Houses: a Comparison of System Configurations and Control Strategies. 12th REHVA World Congress CLIMA 2016 (full paper review and oral presentation). 22 May 2016, Aalborg, Denmark.
Download PDF Details AbstractNowadays prefabricated houses are becoming increasingly popular, thanks to their low cost and high energy performance. Heating systems installed in these houses should be carefully designed and controlled, to ensure sufficient thermal comfort while maintaining low fuel consumptions. This study presents the simulation of different system configurations and control strategies for a pre-fabricated house, located in Lower Austria. The house is heated by a 6 kW pellet boiler directly connected to a floor heating system, in a configuration without buffer storage tank. Using the TRNSYS simulation suite, a coupled simulation of the house and its heating and hot water supply system was set up, calibrated and validated with reference to monitoring data. As monitoring data evidenced that the control strategy of the heating system is not ideal to maintain a comfortable indoor temperature during the whole day, two improved strategies were simulated over the heating season and evaluated in terms of thermal comfort, pellet consumption and boiler’s efficiency. Moreover, to better understand the influence of the system configuration, simulations have been repeated considering another heat distribution system (radiators instead of floor heating). Results show that the radiators’ network, if adequately controlled, reduces by 85% the total discomfort time. In addition, the pellet boiler mainly operates in load modulation regime, leading to lower pellet supply rates and therefore to lower pellet consumptions (18% less than floor heating). However, the lower operational loads and frequent ignitions result in a slightly lower efficiency of the pellet boiler (4% less than the configuration with floor heating.
Peer reviewed papers | 2016
Characterization of biochars produced from pyrolysis of pelletized agricultural residues
Colantoni A, Evic N, Lord R, Retschitzegger S, Proto A, Gallucci F, Monarca D. Characterization of biochars produced from pyrolysis of pelletized agricultural residues. Renewable and Sustainable Energy Reviews. 1 October 2016;64: 187-194.
External Link Details AbstractBiochars produced from pelletized grape vine (GV) and sunflower husk (SFH) agricultural residues were studied by pyrolysis in a batch reactor at 400 and 500 °C. Chemical and physical evolution of the biomass under pyrolysis conditions was determined and the products were characterized, including the main gaseous organic components. Results showed a decrease in solid biochar yield with increasing temperature. Biochar is defined as a “porous carbonaceous solid” produced by thermochemical conversion of organic materials in an oxygen depleted atmosphere, which has physiochemical properties suitable for the safe and long-term storage of carbon in the environment and, potentially, soil improvement. The aim of this work is to improve the knowledge and acceptability of alternative use of the biochar gained from agro-forestry biomass residuals, such as grape vine and sunflower husks, by means of modern chemical and physical characterization tools.
Other papers | 2016
Cold flow modelling of char concentration in the recirculated bed material stream of a dual fluidized bed steam gasification system
Kraft S, Kirnbauer F, Hofbauer H. Cold flow modelling of char concentration in the recirculated bed material stream of a dual fluidized bed steam gasification system. Fluidization XV. 22-27 May 2016, Quebec, Canada.
External Link Details AbstractThe dual fluidized bed (DFB) steam gasification technology of biomass was developed at Vienna University of Technology and is well-established for transforming biomass into a product gas which can be used for further applications. The DFB steam gasification reactor consists of a gasification chamber (bubbling bed, fluidized with steam) and a combustion chamber (turbulent bed, fluidized with air). Biomass is fed into the gasification chamber and gets in contact with the bed material, typically Olivine, at about 840°C. The released volatiles leave the gasification reactor as product gas. A part of the solid residue, called char, flows with the bed material via a chute to the combustion chamber where it is burnt with air. The bed material is heated up, separated from the flue gas stream in a cyclone and flows back to the gasification reactor via a loop seal where it provides the heat for devolatilization and drying of the biomass. The movement of the char is crucial since a sufficient amount has to flow to the combustion chamber and burn to provide enough energy for bed material heat-up. Up to now little is known about the char concentration in the bed material recirculation stream (or short recirculation stream) and its influencing variables. Therefore, a cold flow model, operated with ambient air, was constructed to study the influence of various parameters on the char concentration in the recirculation stream. Bronze is used as bed material since is matches closest to the scaling criteria. The char is also scaled; polyethylene is used as model char.
The cold flow model, see Figure 1 for the flowsheet, consists of a “gasification chamber” which corresponds to the gasification chamber in the hot plant and is as well operated as a bubbling bed. Via a chute the recirculation stream moves to a rotary valve which enables to set a fixed recirculation rate and make it independent from the following pneumatic conveying. Then, gas and solids are separated in a cyclone and the recirculation stream finally flows back to the gasification chamber. After the loop seal samples are taken for investigation of the model char concentration in the recirculation stream. In the present study the influence of fluidization rate in the gasification chamber, bed material recirculation rate and model char mass in the system on the char concentration in the recirculation stream are investigated. It was found that the model char particles show a flotsam behavior. Higher fluidization rates increase the model char concentration in the recirculation stream because of better mixing, whereas the bed material recirculation rate has only little influence. Doubling and tripling the overall char mass in the system did not lead to a doubling or tripling model char concentration in the recirculation stream. The present observations are helping to better understand the ongoing phenomena inside of the dual fluidized bed gasification reactor and provide knowledge to further optimize it.
Conference presentations and posters | 2016
Detailed Reaction Schemes and Product Characterization Applied to Pyrolysis of a Single Spruce Particle
Andrés Anca-Couce, Peter Sommersacher, Robert Scharler, Christoph Hochenauer. Detailed Reaction Schemes and Product Characterization Applied to Pyrolysis of a Single Spruce Particle. 24rd European Biomass Conference & Exhibition (oral presentation).
DetailsPeer reviewed papers | 2016
Dominating high temperature corrosion mechanism in low alloy steels in wood chips fired boilers
Gruber T, Retschitzegger S, Scharler R, Obernberger I. Dominating high temperature corrosion mechanism in low alloy steels in wood chips fired boilers. Energy and Fuels. 17 March 2016;30(3): 2385-2394.
External Link Details AbstractAsh related problems such as slagging, fouling, and high temperature corrosion in biomass fired boilers are still insufficiently explored due to the complexity of the underlying processes. High temperature corrosion of low alloy steels like 13CrMo4-5 has already been investigated in plants firing chemically untreated wood chips. In this earlier work it has been suggested that the oxidation of the steel is the dominating mechanism in the material temperature range between 450 and 550 °C. Unfortunately the exponential dependence of the material degradation on the flue gas temperature also found within this work cannot be explained with the proposed corrosion mechanism. To determine the dominating corrosion mechanism, additionally test runs have been carried out in a specially designed drop tube reactor. To investigate the time-dependent corrosion behavior of 13CrMo4-5, a newly developed mass loss probe was applied under several constant parameter setups. In addition to these measurements, the time-dependent oxidation of 13CrMo4-5 under air was investigated in a muffle furnace. To gain relevant information regarding the corrosion mechanism prevailing, the deposits as well as the corrosion products have been examined subsequently to the test runs by means of scanning electron microscopy and energy dispersive X-ray analyses. With the experimental data gained it could be shown that the dominating corrosion mechanism strongly depends on the conditions prevailing (e.g., steel temperature, flue gas temperature, and velocity) and can either be the oxidation of the steel by gaseous O2 and H2O or a combination of oxidation and active Cl-induced oxidation.
Other Publications | 2016
Emission Reduction of Firewood Roomheaters by Optimization of Operating Conditions and Catalyst Integration
Reichert G, Stressler H, Schmidl C, Schwabl M, Sturmlechner R, Haslinger W. Emission Reduction of Firewood Roomheaters by Optimization of Operating Conditions and Catalyst Integration. 24th European Biomass Conference & Exhibition (oral presentation). June 2016, Amsterdam, Netherlands.
DetailsOther papers | 2016
Energetische Verwertung einer Feinfraktion aus der MBA durch pyrolytische Behandlung
Meirhofer M, Wartha C, Strasser C. Energetische Verwertung einer Feinfraktion aus der MBA durch pyrolytische Behandlung. Recy & DepoTech 2016 (poster). November 2016, Leoben, Austria.
DetailsPeer reviewed papers | 2016
Enhanced Separation of the Organic Fraction from Paper Mill Effluent for Energy Recovery
Stoyanova E, Bochmann G, Couperus A, Fuchs W. Enhanced Separation of the Organic Fraction from Paper Mill Effluent for Energy Recovery. Waste and Biomass Valorization. 1 October 2016;7(5): 1031-1039.
External Link DetailsPeer reviewed papers | 2016
Experimental investigations of hydrogen production from CO catalytic conversion of tar rich syngas by biomass gasification
Chianese S, Fail S, Binder M, Rauch R, Hofbauer H, Molino A, Blasi A, Musmarra D. Experimental investigations of hydrogen production from CO catalytic conversion of tar rich syngas by biomass gasification. Catalysis Today. 15 November 2016;277: 181-192.
External Link Details AbstractIn this paper, the activity of a cobalt/molybdenum (Co/Mo) commercial catalyst for the Water Gas Shift Reaction for hydrogen production was investigated in a three fixed-bed reactor pilot plant using a tar-rich synthesis gas from a full-scale biomass gasification plant as feed-stream. A parametric variation study was carried out to assess CO conversion (XCO) and selectivity for the water gas shift reaction as a function of the operating temperature (T) in the range 300–450 °C. The effects of four dry gas hourly space velocities (GHSV), Case A-Case D, two steam to dry synthesis gas ratios (H2O/SG), 56% v/v and 67% v/v, and a H2S concentration in the range 100–220 ppmv,db were investigated: the highest CO conversion (∼95%) was observed in the base case (Case A GHSV) at 67% v/v H2O/SG, and 450 °C, the lower the operating temperature the lower the CO concentration, the lower the gas hourly space velocity the higher the CO conversion and the higher the H2O/SG the higher the CO conversion. The effect of H2S variation on CO conversion was also studied, keeping the operating temperature constant (≈365 °C) and using the Case D GHSV: CO conversion increased as the H2S concentration increased and XCO ≈ 40%. Selectivity was not influenced by the parameters investigated. Finally, the effect of the catalyst on tar removal was studied and a CO conversion close to 85% was found.
Other papers | 2016
Harmonised Greenhouse Gas Calculations for Electricity, Heating and Cooling from Biomass
Ludwiczek N, Bacovsky D, Sonnleitner A, Strasser C. Harmonised Greenhouse Gas Calculations for Electricity, Heating and Cooling from Biomass. e-nova 2016 (oral presentation). November 2016, Pinkafeld, Austria.
DetailsPeer reviewed papers | 2016
Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification
Kraussler M, Binder M, Schindler P, Hofbauer H. Hydrogen production within a polygeneration concept based on dual fluidized bed biomass steam gasification. Biomass and Bioenergy. 24 December 2016;
External Link DetailsOther papers | 2016
Hythane from biomass steam gasification as natural gas substitute in industrial applications
Kraussler M, Schindler P, Hofbauer H. Hythane from biomass steam gasification as natural gas substitute in industrial applications. Biorestec (poster). October 2016, Sitges, Spain.
DetailsReports | 2016
IEA Bioenergy Countries´ Report
Bacovsky D, Dissauer C, Enigl M, Ludwiczek N, Pointner C, Sonnleitner A, Verma VK. IEA Bioenergy Countries´ Report. IEA Bioenergy Countries´ Report. August 2016.
DetailsPeer reviewed papers | 2016
Impact of Na Promoter on Structural Properties and Catalytic Performance of CoNi/Al2O3 Nanocatalysts for the CO Hydrogenation Process: Fischer–Tropsch Technology
Nikparsa P, Mirzaei AA, Rauch R. Impact of Na Promoter on Structural Properties and Catalytic Performance of CoNi/Al2O3 Nanocatalysts for the CO Hydrogenation Process: Fischer–Tropsch Technology. Catalysis Letters. January 2016;146(1): 61-71.
External Link DetailsOther papers | 2016
Improving the propanol yield of mixed alcohol synthesis based on wood gas derived from biomass steam gasification
Binder M, Rauch R, Hofbauer H. Improving the propanol yield of mixed alcohol synthesis based on wood gas derived from biomass steam gasification. iSGA 2016 - 5th International Symposium on Gasification and its Applications (invited lecture). November/December 2016, Busan, Korea.
DetailsPeer reviewed papers | 2016
Influence of firebed temperature on particle emissions in a residential wood pellet boiler
Gehrig M, Jäger D, Pelz SK, Weissinger A, Groll A, Thorwarth H, Haslinger W. Influence of firebed temperature on particle emissions in a residential wood pellet boiler. Atmospheric Environment. July 2016;136: 61-67.
External Link Details AbstractThe crucial point in inorganic particle formation from biomass combustion is the temperature-dependent release of inorganic compounds, especially potassium (K). Currently, common wood fuels comprise of a comparatively low amount of K, but the increased usage of wood energy requires new feedstocks in the future. Potentially new feedstocks, such as short rotation coppice (SRC), fuels from agriculture (e.g., straw), or wood from broad-leafed trees of low rotation, contain usually high ash contents and/or high K concentrations. Apparently, these feedstocks will cause increased inorganic particle emissions from biomass combustion processes. The principle of a decreased firebed temperature as a primary measure aiming at a retention of K in the ashes of the firebed is a common approach for particle emission reduction and was investigated in several previous studies. The present study describes the usage of an ash-rich fuel from SRC pellets made from willow in a residential pellet boiler modified with an unique prototype of direct water-based firebed cooling. This test setup enables the study of the isolated impact of decreased firebed temperatures and its influence on the combustion process and emissions as well. A statistically significant effect of the firebed cooling on temperatures below the burner plate as on gaseous HCl and SO2 was found. The high ash content of the used fuel limited the effectiveness of the applied direct firebed cooling in residential biomass combustion. The accumulation of a thick and thermal insulating ash layer above the burner plate decreased the heat transfer, limited the cooling efficiency, and revealed deviations from the expected particle formation process.
Other Publications | 2016
Influence of leak tightness and heat storage capacity of biomass room heating appliances on thermal efficiency
Sturmlechner R, Reichert G, Stressler H, Aigenbauer S, Schmidl C, Schwabl M, Haslinger W. Influence of leak tightness and heat storage capacity of biomass room heating appliances on thermal efficiency. 24th European Biomass Conference & Exhibition (poster). June 2016, Amsterdam, Netherlands.
DetailsPeer reviewed papers | 2016
Investigation of real life operation of biomass room heating appliances – results of a European survey
Wöhler M, Andersen JS, Becker G, Persson H, Reichert G, Schön C, Schmidl C, Jaeger D, Pelz SK. Investigation of real life operation of biomass room heating appliances – results of a European survey. Applied Energy. 1 May 2016;169: 240-249.
External Link DetailsPeer reviewed papers | 2016
Investigation of User Behavior and Assessment of Typical Operation Mode for Different Types of Firewood Room Heating Appliances in Austria
Reichert G, Schmidl C, Haslinger W, Schwabl M, Moser W, Aigenbauer S, Wöhler M, Hochenauer C. Investigation of User Behavior and Assessment of Typical Operation Mode for Different Types of Firewood Room Heating Appliances in Austria. Renewable Energy. August 2016;93: 245-254.
External Link Details AbstractFirewood heaters like firewood roomheaters, tiled stoves and residential biomass cookers are commonly used for supplying the residences with renewable heat. However, these kinds of appliances were identified as responsible for relevant amounts of gaseous CO and OGC as well as particulate emissions causing negative health effects. Beside technological reasons, the operating conditions and the user behavior are essential reasons for increased emissions, especially in real life operation.
Therefore, this study aimed at an investigation and assessment of typical real life user behavior by a survey. Based on the findings effective and customer friendly technological and non-technological optimization approaches for a better and more environmental friendly real life performance were defined.
The results of the study showed principally similar user behavior of all considered types of appliances regarding most relevant operation characteristics, i.e. kind, properties and amount of used fuels, ignition procedure and air valve settings. Most effective non-technological optimization approaches were found for an enhancement of external training arrangements and the development of user friendly manuals that aimed mainly at an improvement of the ignition procedure from bottom–up to top–down ignition method. The use of devices with an automatically controlled combustion air supply was identified as promising technological measure.
Other papers | 2016
Investigations of a dual fluidized bed steam gasification plant by means of computation particle fluid dynamics
Kraft S, Kirnbauer F, Hofbauer H. Investigations of a dual fluidized bed steam gasification plant by means of computation particle fluid dynamics. 24th European Biomass Conference & Exhibition (oral presentation). June 2016, Amsterdam, Netherlands.
DetailsOther Publications | 2016
Market integration of wood fuels and heating oil
Kristöfel C, Strasser C, Schmid E, Morawetz UB. Market integration of wood fuels and heating oil. 24th European Biomass Conference & Exhibition (poster). June 2016, Amsterdam, Netherlands.
DetailsConference presentations and posters | 2016
Mathematische Modellierung mittlerer bis großer Solaranlagen als Basis für modellbasierte Regelungsstrategien
Unterberger V, Lichtenegger K, Innerhofer P, Gerardts B, Gölles M. Mathematische Modellierung mittlerer bis großer Solaranlagen als Basis für modellbasierte Regelungsstrategien. Gleisdorf Solar 2016. Gleisdorf: 2016. (Auszeichnung als innovativstes Poster).
DetailsPeer reviewed papers | 2016
Mechanism of Layer Formation on Olivine Bed Particles in Industrial-Scale Dual Fluid Bed Gasification of Wood
Kuba M, He H, Kirnbauer F, Skoglund N, Boström D, Öhman M, Hofbauer H. Mechanism of Layer Formation on Olivine Bed Particles in Industrial-Scale Dual Fluid Bed Gasification of Wood. Energy & Fuels. 15 September 2016;30(9): 7410-7418.
External Link Details AbstractUtilization of biomass as feedstock in dual fluidized bed steam gasification is a promising technology for the substitution of fossil energy carriers. Experience from industrial scale power plants showed an alteration of the olivine bed material due to interaction with biomass ash components. This change results mainly in the formation of Ca-rich layers on the bed particles. In this paper, a mechanism for layer formation is proposed and compared to the better understood mechanism for layer formation on quartz bed particles. Olivine bed material was sampled at an industrial scale power plant before the start of operation and at pre-defined times after the operation had commenced. Therefore, time dependent layer formation in industrial-scale conditions could be investigated. The proposed mechanism suggests that the interaction between wood biomass ash and olivine bed particles is based on a solid-solid substitution reaction, where Ca2+ is incorporated into the crystal structure. As a consequence Fe2+/3+ and Mg2+ ions are expelled as oxides. This substitution results in the formation of cracks in the particle layer due to a volume expansion in the crystal structure once Ca2+ is incorporated. The results of this work are compared to relevant published results including those related to quartz bed particles.
Peer reviewed papers | 2016
Methodological approaches for fractionation and speciation to estimate trace element bioavailability in engineered anaerobic digestion ecosystems: An overview
van Hullebusch ED, Guibaud G, Simon S, Lenz M, Yekta SS, Fermoso FG, Jain R, Duester L, Roussel J, Guillon E, Skyllberg U, Almeida CMR, Pechaud Y, Garuti M, Frunzo L, Esposito G, Carliell-Marquet C, Ortner M, Collins G. Methodological approaches for fractionation and speciation to estimate trace element bioavailability in engineered anaerobic digestion ecosystems: An overview. Critical Reviews in Environmental Science and Technology. 17 August 2016;46(16): 1324-1366.
External Link DetailsConference presentations and posters | 2016
Mixed alcohol synthesis based on wood gas derived from dual fluidized bed biomass steam gasification - applying a rapeseed oil methyl ester gas scrubber for gas conditioning
Binder, M., Rauch, R., Hofbauer, H., 2016, "Mixed alcohol synthesis based on wood gas derived from dual fluidized bed biomass steam gasification - applying a rapeseed oil methyl ester gas scrubber for gas conditioning", poster presentation at BioResTec2016 - 1st International Conference on Bioresource Technology for Bioenergy, Bioproducts & Environmental Sustainability , 23 - 26 October 2016, Sitges, Spain.
DetailsPeer reviewed papers | 2016
Modification of Co/Al2O3 Fischer–Tropsch Nanocatalysts by Adding Ni: A Kinetic Approach
Nikparsa P, Mirzaei AA, Rauch R. Modification of Co/Al2O3 Fischer–Tropsch Nanocatalysts by Adding Ni: A Kinetic Approach. International Journal of Chemical Kinetics. 1 March 2016;48(3): 131-142.
External Link DetailsOther Publications | 2016
On site monitoring and dynamic simulation of a low energy house heated by a pellet boiler
Carlon E, Schwarz M, Prada A, Golicza L, Verma V, Baratieri M, Gasparella A, Haslinger W, Schmidl C. On site monitoring and dynamic simulation of a low energy house heated by a pellet boiler. 15 March 2016;116: 296-306.
External Link Details AbstractPrefabricated low energy houses are becoming increasingly popular thanks to their low cost and high energy performance. Heating systems installed in these houses should be optimally designed and controlled, to ensure thermal comfort for the whole heating season.
This study presents the on-site monitoring and dynamic simulation of a low energy house heated by a pellet boiler via a floor heating system. The house combines a lightweight envelope, a heat distribution system with a high thermal inertia and a biomass-based heat supply. The one-year monitoring campaign allowed to closely investigate the system's response to the heat demand. Moreover, a coupled simulation of the house and its heating and hot water supply system was set-up, calibrated, and validated against measured indoor temperature profiles and energy consumptions. Root mean square deviations between simulated and measured indoor temperature were in the range 0.4–0.8 K, while simulated energy consumptions fulfilled the criteria of the ASHRAE 14-2002 Guideline. As monitoring data evidenced the importance of better managing the high thermal inertia of the floor heating system, two improved control strategies were tested in the simulation environment and evaluated in terms of thermal comfort, pellet consumption and efficiency of the pellet boiler.
Conference presentations and posters | 2016
Overview on advanced biofuels technologies
Bacovsky D. Overview on advanced biofuels technologies. Bioenergy Australia 2016. November 2016, Brisbane, Australia.
DetailsOther 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.
DetailsOther 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.
External Link Details AbstractConceptual 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.
Reports | 2016
Production of advanced biofuels
Bacovsky D. Production of advanced biofuels. Nationaler Workshop Biotreibstoffe. September 2016.
External Link Download PDF DetailsOther papers | 2016
Progress in hydrogen production from product gas generated by dual fluidized bed biomass steam gasification
Kraussler M, Hofbauer H. Progress in hydrogen production from product gas generated by dual fluidized bed biomass steam gasification. 24th European Biomass Conference & Exhibition (oral presentation). June 2016, Amsterdam, Netherlands.
DetailsOther Publications | 2016
Progress in Mixed Alcohol Synthesis - Based on Wood Gas Derived from Dual Fluidized Bed Biomass Steam Gasification
Binder, M., Weber, G., Rauch, R., Hofbauer, H.: Progress in Mixed Alcohol Synthesis - Based on Wood Gas Derived from Dual Fluidized Bed Biomass Steam Gasification. Poster presentation at CASCATBEL workshop 2016, 18 - 20 May 2016, Porto Carras, Greece.
DetailsPeer reviewed papers | 2016
Reaction mechanisms and multi-scale modelling of lignocellulosic biomass pyrolysis
Anca-Couce, A. Reaction mechanisms and multi-scale modelling of lignocellulosic biomass pyrolysis. Progress in Energy and Combustion Science. Volume 53, March 2016, Pages 41–79.
External Link Details AbstractIn this work about pyrolysis of lignocellulosic biomass, the individual reaction mechanisms of cellulose, hemicellulose and lignin are initially described. The recent advances in the understanding of the fundamental reaction pathways are described, including quantum-mechanical calculations, and the description of pyrolysis as a two-step process, i.e., primary pyrolysis and secondary charring, the effect of the presence of an intermediate liquid compound, and the influence of inorganic species are discussed.
The need to describe biomass pyrolysis as the sum of the contributions of its individual components is then emphasised. The process of determining biomass mass loss kinetics is analysed, and the product composition and heat of reaction that are experimentally obtained during pyrolysis are presented, along with detailed schemes that can be used to predict them.
Finally, it is demonstrated that a multi-scale consideration of pyrolysis on multiple levels – specifically, on molecular, particle and reaction levels – is required to accurately describe biomass pyrolysis. Intra-particle phenomena and particle models are discussed and the reactor level is analysed with a focus placed on fixed bed and fluidised bed pyrolysis. In summary, a list of 10 research focal points that will be important in the future is presented.
Peer reviewed papers | 2016
Short term online corrosion measurements in biomass fired boilers. Part 2: Investigation of the corrosion behavior of three selected superheater steels for two biomass fuels
Retschitzegger, S., Gruber, T., Brunner, T., Obernberger, I. Short term online corrosion measurements in biomass fired boilers. Part 2: Investigation of the corrosion behavior of three selected superheater steels for two biomass fuels. Fuel Processing Technology. Volume 142, February 2016, Pages 59-70.
External Link Details AbstractThe high temperature corrosion behavior of the boiler steels 13CrMo4-5 (1.7335), P91 (1.4903) and 1.4541 has been investigated during short-term test runs (~ 500 h) at a biomass fired grate furnace combined with a drop tube. For the test runs performed with 13CrMo4-5 and P91 chemically untreated wood chips have been used as fuel, whereas waste wood has been used for test runs with P91 and 1.4541. Online corrosion probes and a mass loss probe have been used applying a methodology developed in a previous study to correct for a measurement error occurring during short-term measurements with online corrosion probes (mass loss correction). Furthermore, deposit probe measurements have been performed to evaluate the deposit build-up rate and the chemical composition of deposits. SEM/EDX analyses of the corrosion probes have been performed subsequently to the test runs to gain information regarding the chemical composition and structure of the deposits as well as the corrosion layers.
The furnace has been operated at constant load to ensure constant combustion conditions. The flue gas temperature at the probes has been varied between 740 and 900 °C and the probe surface temperature has been varied between 400 and 560 °C in order to determine their influence on the corrosion rate.
General trends determined by the variation of these temperatures were similar for all boiler steels: the corrosion rate increased with increasing flue gas temperature and also with increasing probe surface temperature. For chemically untreated wood chips combustion at low flue gas temperatures (740 °C) the corrosion rates were comparable for 13CrMo4-5 and P91 at all probe surface temperatures. However, at flue gas temperatures of 800 °C and higher P91 showed better corrosion resistance than 13CrMo4-5. For waste wood combustion 1.4541 generally showed a better corrosion resistance than P91.
The mass loss correction of the measurement error occurring in the initial phase resulted in different errors of 55% for 13CrMo4-5 and 32% for P91 for chemically untreated wood chips. For waste wood the mass loss correction resulted in errors of 55% for P91 and 77% for 1.4541. The results from the mass loss determination for the waste wood test runs scattered stronger compared to the wood chips test runs. Therefore, the fits were not that accurate and the error margin was higher. However, the results outline that the mass loss correction is relevant in order to achieve a meaningful comparison of different short-term test runs using online corrosion probes.
Peer reviewed papers | 2016
Simultaneous Online Determination of S, Cl, K, Na, Zn, and Pb Release from a Single Particle during Biomass Combustion. Part 2: Results from Test Runs with Spruce and Straw Pellets
Sommersacher P, Kienzl N, Brunner T, Obernberger I. Simultaneous Online Determination of S, Cl, K, Na, Zn, and Pb Release from a Single Particle during Biomass Combustion. Part 2: Results from Test Runs with Spruce and Straw Pellets. Energy and Fuels. 21 April 2016;30(4): 3428-3440.
External Link Details AbstractTo gain better insight into inorganic element release processes, test runs with a specially designed single particle reactor connected with an inductively coupled plasma mass spectrometer (ICP-MS) have been performed. Relevant combustion related parameters such as mass loss during thermal degradation, temperature development of the particle (surface and center), and composition of released gases were recorded. By coupling the reactor to an ICP-MS, time-resolved release profiles of relevant aerosol forming elements (S, Cl, K, Na, Zn, and Pb) were determined. Targeted and controlled interruptions of the experiments (quenching) after a certain time were performed to validate reactor performance and reliability of the measurements. Test runs with softwood and straw pellets (8 mm in diameter and about 20 mm in length) were performed at reactor temperatures of 700, 850, and 1000 °C under oxidizing conditions (5.6 or 4.2 vol % O2). These test runs have revealed that the release ratios of volatile and semivolatile ash forming elements (S, Cl, K, Na, Zn, and Pb) generally increase as reactor temperatures rise. Moreover, regarding straw, higher Si and Al contents influence the release behavior of K, Na, Zn, and Pb. For K, existing release mechanisms proposed in the literature have been confirmed, and for Na it has been suggested that release mechanisms similar to K prevail. Especially during the starting phase of the experiment, a distinct temperature gradient exists from the surface to the center of the particle. Thus, different conversion phases occur in parallel in different layers of the particle, which has to be considered during the interpretation of the time-resolved release profiles of the main inorganic elements. Furthermore, transport limitations due to the occurrence of molten phases (especially for straw at reactor temperatures of 1000 °C) were obvious and could be directly derived from the online recorded release profiles. The targeted interruption of the ongoing decomposition process (quenching) provided an indication of the validity of the release profiles for S, K, Na, Zn, and Pb. Additionally, these experiments delivered valuable information regarding possible release mechanisms.
Reports | 2016
Technology Overview
Strasser C. Technology Overview. New York State Wood Heat Report: An Energy, Environmental, and Market Assessment - Final Report. April 2016. Chapter 8; 141-206.
DetailsPeer reviewed papers | 2016
The influence of oxygen availability on off-gassing rates of emissions from stored wood pellets
Meier F, Sedlmayer I, Emhofer W, Wopienka E, Schmidl C, Haslinger W, Hofbauer H. The influence of oxygen availability on off-gassing rates of emissions from stored wood pellets. Energy & Fuels. 18 February 2016;30(2): 1006-1012.
External Link Details AbstractThe phenomenon of off-gassing from wood pellets during storage has been the cause of several, in some cases fatal, accidents due to toxic atmospheres in storages. To optimize safety measures the nature of the responsible processes needs to be clarified. In this study the impact of O2 availability, which is a decisive factor for the presumed oxidation of fatty acids, is pointed out. Off-gassing rates of CO, CO2, VOC, and CH4 of pellets at relatively constant O2 levels of approximately 35%, 20%, and <1% over a period of 20 d at approximately 295 K were investigated. For this purpose 7 kg of spruce pellets was stored under simulated ventilation of the atmosphere in a 31 L tank. Gas concentrations were determined every 24 h by GC-FID/TCD. Compared to the mean emission rates at 35% O2 of CO (0.22 mg kg–1pelletsd.b. in 24 h) and CO2 (0.76 mg kg–1pelletsd.b. in 24 h) the lowest O2 concentration of <1% resulted in a significant reduction of off-gassing rates of 40% for both gases. In contrast the release rates of VOCs and also CH4 decreased with the higher O2 concentration (0.035 to 0.025 mg kg–1pelletsd.b. in 24 h; 0.0085 to 0.0061 mg kg–1pelletsd.b. in 24 h), presumably, because of increased onward reactions to CO and CO2. Since off-gassing was not prevented by the lack of O2 (<1% O2-trial) it is assumed that the O2 required for the reactions originated from the biomass itself. During the storage of pellets at 20% O2, emission rates of CO (0.18 mg kg–1pelletsd.b. in 24 h) and CO2 (0.79 mg kg–1pelletsd.b. in 24 h) at the start decreased by more than 20% and those for VOCs (0.032 mg kg–1pelletsd.b. in 24 h) by almost 30% after 3 weeks. It can be assumed that in ventilated storages the reactivity and thus a potential risk from off-gases from wood pellets decreases considerably in only a few weeks. The effects of aging, in terms of declining reactivity at relatively constant tank conditions, on off-gassing rates could be clarified for the first time. A realistic development of the decline of reactivity of the material itself could be determined.
Peer reviewed papers | 2016
The interplay of self-reflection, social interaction and random events in the dynamics of opinion flow in two-party democracies
Lichtenegger K, Hadzibeganovic T. The interplay of self-reflection, social interaction and random events in the dynamics of opinion flow in two-party democracies. International Journal of Modern Physics C. 1 May 2016;27(5).
External Link Details AbstractRead More: http://www.worldscientific.com/doi/abs/10.1142/S0129183116500650
Peer reviewed papers | 2016
The Virtual Biomass Grate Furnace - An Overall CFD Model for Biomass Combustion Plants
Ali Shiehnejadhesar, Ramin Mehrabian, Robert Scharler, Christoph Hochenauer. The Virtual Biomass Grate Furnace - An Overall CFD Model for Biomass Combustion Plants. 24rd European Biomass Conference & Exhibition (poster).
External Link Details AbstractThis paper presents the virtual biomass grate furnace, which comprises of comprehensive CFD models of all relevant processes for the simulation of biomass grate furnaces. The models consist of a 3D packed bed model, a gas phase combustion model for laminar to highly turbulent flows and a model to account for the influence of the flue gas streaks arising from the fuel bed in the freeboard. The simulation results of a 20 kW underfeed stoker furnace show that the overall CFD model is able to provide valuable insight on the processes occurring in the packed bed and freeboard and their interactions.
Other papers | 2016
The wood pellet market in Austria: A structural market model analysis
Christa Kristöfel, Christoph Strasser, Erwin Schmid, Ulrich B. Morawetz, The wood pellet market in Austria: A structural market model analysis, Energy Policy, Volume 88, January 2016, Pages 402-412,
External Link DetailsPeer reviewed papers | 2016
Thermal Stability of Bed Particle Layers on Naturally Occurring Minerals from Dual Fluid Bed Gasification of Woody Biomass
Kuba M, He H, Kirnbauer F, Skoglund N, Boström D, Öhman M, Hofbauer H. Thermal Stability of Bed Particle Layers on Naturally Occurring Minerals from Dual Fluid Bed Gasification of Woody Biomass. Energy & Fuels. 20 October 2016;30(10): 8277-8285.
External Link Details AbstractThe use of biomass as feedstock for gasification is a promising way of producing not only electricity and heat but also fuels for transportation and synthetic chemicals. Dual fluid bed steam gasification has proven to be suitable for this purpose. Olivine is currently the most commonly used bed material in this process due to its good agglomeration performance and its catalytic effectiveness in the reduction of biomass tars. However as olivine contains heavy metals such as nickel and chromium no further usage of the nutrient-rich ash is possible and additional operational costs arise due to necessary disposal of the ash fractions. This paper investigates possible alternative bed materials and their suitability for dual fluid bed gasification systems focusing on the behavior of the naturally occurring minerals olivine, quartz and K-feldspar in terms of agglomeration and fractionation at typical temperatures. To this end samples of bed materials with layer formation on their particles were collected at the industrial biomass combined heat and power (CHP) plant in Senden, Germany, which uses olivine as the bed material and woody biomass as feedstock. The low cost logging residue feedstock contains mineral impurities such as quartz and K-feldspar which become mixed into the fluidized bed during operation. Using experimental analysis and thermochemical it was found that the layers on olivine and K-feldspar showed a significantly lower agglomeration tendency than quartz. Significant fractionation of particles or their layers could be detected for olivine and quartz, whereas K-feldspar layers were characterized by a higher stability. High catalytic activity is predicted for all three minerals once Ca-rich particle layers are fully developed. However quartz may be less active during the build-up of the layers due to lower amounts of Ca in the initial layer formation.
Other papers | 2016
Thermochemische Behandlung eines niederkalorischen Reststoffes zur Gewinnung von Sekundärrohstoffen
Meirhofer M, Dißauer C, Strasser C, Kranner R, Wartha C. Thermochemische Behandlung eines niederkalorischen Reststoffes zur Gewinnung von Sekundärrohstoffen. e-nova 2016 (oral presentation). November 2016, Pinkafeld, Austria.
DetailsPeer reviewed papers | 2016
Toxicological characterization of particulate emissions from straw, Miscanthus, and poplar pellet combustion in residential boilers
Kasurinen S, Jalava PI, Uski O, Happo MS, Brunner T, Mäki-Paakkanen J, Jokiniemi J, Obernberger I, Hirvonen MR. Toxicological characterization of particulate emissions from straw, Miscanthus, and poplar pellet combustion in residential boilers. Aerosol Science and Technology. 2 January 2016;50(1): 41-51.
External Link Details AbstractWood pellets have been used in domestic heating appliances for three decades. However, because the share of renewable energy for heating will likely rise over the next several years, alternative biomass fuels, such as short-rotation coppice or energy crops, will be utilized. We tested particulate emissions from the combustion of standard softwood pellets and three alternative pellets (poplar, Miscanthus sp., and wheat straw) for their ability to induce inflammatory, cytotoxic, and genotoxic responses in a mouse macrophage cell line. Our results showed clear differences in the chemical composition of the emissions, which was reflected in the toxicological effects. Standard softwood and straw pellet combustion resulted in the lowest PM1 mass emissions. Miscanthus sp. and poplar combustion emissions were approximately three times higher. Emissions from the herbaceous biomass pellets contained higher amounts of chloride and organic carbon than the emissions from standard softwood pellet combustion. Additionally, the emissions of the poplar pellet combustion contained the highest concentration of metals. The emissions from the biomass alternatives caused significantly higher genotoxicity than the emissions from the standard softwood pellets. Moreover, straw pellet emissions caused higher inflammation than the other samples. Regarding cytotoxicity, the differences between the samples were smaller. Relative toxicity was generally highest for the poplar and Miscanthus sp. samples, as their emission factors were much higher. Thus, in addition to possible technical problems, alternative pellet materials may cause higher emissions and toxicity. The long-term use of alternative fuels in residential-scale appliances will require technological developments in both burners and filtration.
Peer reviewed papers | 2016
Two-stage cultivation of N-rich and N–deprived Acutodesmus obliquus biomass: Influence of cultivation and dewatering methods on microalgal biomass used in anaerobic digestion
Gruber M, Nussbaumer M, Jerney J, Ludwig I, Zohar E, Lang I, Bochmann G, Schagerl M, Obbard JP, Fuchs W, Drosg B. Two-stage cultivation of N-rich and N–deprived Acutodesmus obliquus biomass: Influence of cultivation and dewatering methods on microalgal biomass used in anaerobic digestion. Algal Research. July 2016;17: 105-112.
External Link DetailsPeer reviewed papers | 2016
Valorisation of slaughter house and deinking paper waste streams for the production of enzyme by Trichoderma reesei
Weiss R, Eischer A, Tadic T, Gritsch SM, Ortner M, Prall K, Neunteufel E, Putz RF, Guebitz GM, Nyanhongo GS. Valorisation of slaughter house and deinking paper waste streams for the production of enzyme by Trichoderma reesei. Journal of Cleaner Production. 2020;275:122882
External Link Details AbstractThe study investigates for the first time the possibility of using carbon rich paper recovery sludge, and nitrogen rich meat processing industry waste as cultivation medium for the production of high value enzymes needed in the respective industries. The complex cellulose rich deinking sludge was able to support the growth of many industrially relevant enzyme producing microorganisms (Bacillus licheniformis, Candida cylindracea, Aspergillus oryzae, Trichoderma reesei) and of recombinant enzyme producers (Escherichia coli and Pichia pastoris). Further detailed studies with Trichoderma reesei as model organism demonstrated that the organism was able to grow optimally in the presence of 40gL-1 paper sludge as carbon source and 67.5 gL-1 pasteurised blood as nitrogen source substituted in Mandels medium. Under these conditions cellulase activities up to 28.1 nkat FPU were achieved. Anyhow, to achieve these results pretreatment of both waste streams is inevitable. In summary, this study provides the practical basis for a valorisation systems of paper industry waste to produce valuable enzymes to be used on-site in paper processing or for other purposes.
Reports | 2017
2016 Survey of Non-Starch Alcohol and Renewable Hydocarbon Biofuels Producers
Warner E, Bacovsky D, Schwab A. 2016 Survey of Non-Starch Alcohol and Renewable Hydocarbon Biofuels Producers. 2016 Survey of Non-Starch Alcohol and Renewable Hydocarbon Biofuels Producers. February 2017.
DetailsPeer reviewed papers | 2017
A Generalization of Ackermann’s Formula for the Design of Continuous and Discontinuous Observers
Anca-Couce A, Sommersacher P, Scharler R. Online experiments and modelling with a detailed reaction scheme of single particle biomass pyrolysis. Journal of Analytical and Applied Pyrolysis. Available online 17 July 2017
External Link Details AbstractDetailed reaction schemes and experimental data for the online release of pyrolysis volatiles are required to gain a more fundamental understanding of biomass pyrolysis, which would in turn allow the process to be controlled in a more precise way and the development of more targeted applications. A detailed online characterisation of pyrolysis products has been conducted in single particle experiments with spruce pellets at different temperatures, obtaining a good closure of the elemental mass balances. The yields and online release of CO, CO2, H2O, CH4, other light hydrocarbons and total organic condensable species, as well as char yield and composition, can be predicted with a reasonable accuracy with the application of a single particle model, coupled with a detailed pyrolysis scheme, and a simple one-step scheme for tar cracking. In order to achieve it, improvements have been conducted in the pyrolysis scheme, mainly concerning the release of light hydrocarbons and char yield and composition. Deviations are still present in the different groups in which organic condensable species can be classified.
Peer reviewed papers | 2017
A hybrid of winddiesel technology with biomass-based Fischer-Tropsch synthesis
Nikparsa P, Rauch R, Mirzaei AA. A hybrid of winddiesel technology with biomass-based Fischer-Tropsch synthesis. Monatshefte für Chemie. 10 July 2017;1-10.
External Link Details AbstractThe syngas mixture produced from biomass (bio-syngas) is characterized by a H2/CO molar ratio of 1.5 in this work, which is different from that of traditional syngas ratio of 2. Therefore a hybrid of winddiesel technology with bio-syngas conversion by Fischer–Tropsch synthesis (WD-FT) on a cobalt based catalyst was investigated, for the first time, using a slurry reactor. The result from feeding this technology is compared with the direct converting biomass derived synthetic gas to fuels via Fischer–Tropsch synthesis (BS-FT). Experiments were performed at different syngas composition (variation of H2/CO ratio), keeping the other parameters (temperature 230 °C; gas flow 5 Nm³/h, pressure 20 bar) constant. Comparison of the WD-FT with the BS-FT synthesis results displayed mass fraction of light hydrocarbons and higher catalytic stability and activity after 500 h. The olefin structures for the different product distributions, obtained from different reactions, are determined by ¹H NMR spectroscopy. Negligible amounts of iso-α-olefins were detected in the product of the WD-FT reaction. In the case of the alpha value, a slight change was observed between 0.93 and 0.92 for the BS-FT and WD-FT reaction.
Other papers | 2017
A novel approach for the implementation of TORrefaction in Residential and COMmunal heating Boilers (TORRECOMB)
Kourkoumpa DS, Kienzl N, Isemin R, Strasser C, Nikolopoulus N, Margaritis N, Panagiotis G. A novel approach for the implementation of TORrefaction in Residential and COMmunal heating Boilers (TORRECOMB). 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
DetailsOther papers | 2017
A Theoretical and Experimental Study of the Formation of Aromatic Hydrocarbons (BTX/PAH) as Soot Precursors from Biomass Pyrolysis Products
Mehrabian R, Shiehnejadhesar A, Bahramian H, Anca-Couce A, Sommersacher P, Hochenauer C, Scharler R. A Theoretical and Experimental Study of the Formation of Aromatic Hydrocarbons (BTX/PAH) as Soot Precursors from Biomass Pyrolysis Products. 25th European Biomass Conference & Exhibition (oral presentation). May 2017, Stockholm, Sweden.
External Link Details AbstractIn this work a novel reaction mechanism for gas phase reactions has been developed to predict the formation of aromatic compounds from the pyrolysis products of woody biomass particles. The aromatic compounds are important for being main soot precursors as well as their toxic properties. The developed gas phase mechanism is validated with experimental data from literature as well as experimental data performed with a single particle reactor for three different pyrolysis temperatures, namely 550, 800 and 1000°C. A good agreement is achieved between model results and experimental data for the total yield of each main family of aromatic hydrocarbons, i.e. phenolics, BTXs and PAHs.
Conference presentations and posters | 2017
Abschätzung der Ertragssteigerung durch moderne Regelungsstrategien
Innerhofer P, Unterberger V, Gerardts B, Lichtenegger K, Gölles M. Abschätzung der Ertragssteigerung durch moderne Regelungsstrategien. 27. Symposium Thermische Solarenergie OTTI. Bad Staffelstein, Deutschland: 2017.
DetailsPeer reviewed papers | 2017
Acid base interaction and its influence on the adsorption kinetics and selectivity order of aromatic sulfur heterocycles adsorbing on Ag-Al2O3
Neubauer R, Husmann M, Weinlaender C, Kienzl N, Leitner E, Hochenauer C. Acid base interaction and its influence on the adsorption kinetics and selectivity order of aromatic sulfur heterocycles adsorbing on Ag-Al2O3. Chemical Engineering Journal. 1 February 2017;309: 840-849.
External Link Details AbstractAdsorptive desulfurization is a promising technology to provide sulfur free fuels for fuel cell based power units. In this work the adsorption kinetics of three different aromatic sulfur heterocycles was studied for Ag-Al2O3. The influence of individual as well as competitive adsorption on the selectivity order was investigated by equilibrium and breakthrough experiments. In these experiments a jet-A1 fuel enriched with benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was used. The adsorption of aromatic sulfur heterocycles on Ag-Al2O3 proceeds via three different adsorption mechanisms. Within these mechanisms the π-interaction (π-Ag) and the direct sulfur-silver interaction (S-Ag) are significantly stronger in comparison to the acid base interaction (S-H). The results showed that the π-Ag and S-Ag interactions are the major adsorption mechanisms in the first stage, where film-diffusion limits the adsorption rate. In the second stage, the S-H interaction plays only an important role for BT, where intraparticle diffusion is the rate controlling step. The overall selectivity order was found to be BT > DBT > 4,6-DMDBT in the case of competitive adsorption for both equilibrium and breakthrough performance. The S-H contribution was related to incorporation of silver into blank γ-alumina, which significantly increased the overall acidity of the adsorbent.
Peer reviewed papers | 2017
An experimental approach aiming the production of a gas mixture composed of hydrogen and methane from biomass as natural gas substitute in industrial applications
Kraussler M, Schindler P, Hofbauer H. An experimental approach aiming the production of a gas mixture composed of hydrogen and methane from biomass as natural gas substitute in industrial applications. Bioresource Technology. August 2017;237: 39-46.
External Link DetailsOther papers | 2017
An investigation on the behaviour of nitrogen based impurities over a water gas shift stage and a biodiesel scrubber
Loipersböck J, Rauch R, Hofbauer H. An investigation on the behaviour of nitrogen based impurities over a water gas shift stage and a biodiesel scrubber. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
DetailsPeer reviewed papers | 2017
Apparent kinetics of the water-gas-shift reaction in biomass gasification using ash-layered olivine as catalyst.
Krycaa J, Priščák J, Łojewskac J, Kuba M, Hofbauer H. Apparent kinetics of the water-gas-shift reaction in biomass gasification using ash-layered olivine as catalyst. Chemical Engineering Journal. 2018, 346: 113-119.
External Link Details AbstractSubstitution 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.
Other papers | 2017
Ash and bed material research in dual fluidized bed gasification of biomass in lab- and industrial-scale
Kuba M, Hofbauer H. Ash and bed material research in dual fluidized bed gasification of biomass in lab- and industrial-scale. 25th European Biomass Conference & Exhibition (oral presentation). June 2017, Stockholm, Sweden.
DetailsPeer reviewed papers | 2017
Assessment of correlations between tar and product gas composition in dual fluidized bed steam gasification for online tar prediction.
Benedikt F, Kuba M, Schmid JC, Müller S, Hofbauer H. Assessment of correlations between tar and product gas composition in dual fluidized bed steam gasification for online tar prediction. Applied Energy 2019;238:1138-1149.
External Link Details AbstractThermochemical 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.
Peer reviewed papers | 2017
Behavior of GCMS tar components in a water gas shift unit operated with tar-rich product gas from an industrial scale dual fluidized bed biomass steam gasification plant
Kraussler M, Binder M, Hofbauer H. Behavior of GCMS tar components in a water gas shift unit operated with tar-rich product gas from an industrial scale dual fluidized bed biomass steam gasification plant. Biomass Conversion and Biorefinery. 1 March 2017;7(1): 69-79.
External Link DetailsOther Publications | 2017
Bidirektionale Wärmenetze: Regelung, Energiemanagement, Potenzial
Lichtenegger K, Leitner A, Moser A, Muschick D, Höftberger E, Gölles M. Bidirektionale Wärmenetze: Regelung, Energiemanagement, Potenzial. Workshop auf der Central European Biomass Conference 2017.
External Link DetailsPeer reviewed papers | 2017
Characteristics and synergistic effects of co-combustion of carbonaceous wastes with coal
Onenc S, Retschitzegger S, Evic N, Kienzl N. Characteristics and synergistic effects of co-combustion of carbonaceous waste with coal. ATHENS 2017 5th International Conference on Sustainable Solid Waste Management (Poster). June 2017, Athens, Greece.
External Link Details AbstractThis study presents combustion behavior and emission results obtained for different fuels: poultry litter (PL) and its char (PLC), scrap tires (ST) and its char (STC) and blends of char/lignite (PLC/LIG and STC/LIG). The combustion parameters and emissions were investigated via a non-isothermal thermogravimetric method and experiments in a lab-scale reactor. Fuel indexes were used for the prediction of high temperature corrosion risks and slagging potentials of the fuels used. The addition of chars to lignite caused a lowering of the combustion reactivity (anti-synergistic effect). There was a linear correlation between the NOx emissions and the N content of the fuel. The form of S and the concentrations of alkali metals in the fuel had a strong effect on the extent of SO2 emissions. The use of PL and PLC in blends reduced SO2 emissions and sulphur compounds in the fly ash. The 2S/Cl ratio in the fuel showed that only PLC and STC/PLC would show a risk of corrosion during combustion. The ratio of basic to acidic oxides in fuel indicated that ST, STC and STC/LIG have low slagging potential. The molar (Si + P + K)/(Ca + Mg) ratio, which was used for PL, PLC and PLC containing blends, showed that the ash melting temperatures of these fuels would be higher than 1000 °C.
Peer reviewed papers | 2017
Characteristics of adapted hydrogenotrophic community during biomethanation
Rachbauer L, Beyer R, Bochmann G, Fuchs W. Characteristics of adapted hydrogenotrophic community during biomethanation. Science of The Total Environment. 1 October 2017;595: 912-919.
External Link DetailsPeer reviewed papers | 2017
Characterization of polyhydroxyalkanoates produced by Synechocystis salina from digestate supernatant
Kovalcik A, Meixner K, Mihalic M, Zeilinger W, Fritz I, Fuchs W, Kucharczyk P, Stelzer F, Drosg B. Characterization of polyhydroxyalkanoates produced by Synechocystis salina from digestate supernatant. International Journal of Biological Macromolecules. 1 September 2017;102: 497-504.
External Link DetailsOther Publications | 2017
Clean Air by Biomass - Demonstration of clean and efficient combustion of biomass
Klauser F, Schwabl M, Reichert G, Schmidl C, Weissinger A. Clean Air by Biomass - Demonstration of clean and efficient combustion of biomass. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
DetailsOther Publications | 2017
CleanAir by Biomass - Status Quo Analysis of the Model Region
Klauser F, Sturmlechner R, Schwabl M, Reichert G, Schmidl C, Weissinger A, Haslinger W, Stressler H. CleanAir by Biomass - Status Quo Analysis of the Model Region. 25th European Biomass Conference & Exhibition (oral presentation). June 2017, Stockholm, Sweden.
DetailsPeer reviewed papers | 2017
CO/CO2 Ratio in biomass char oxidation
Anca-Couce A, Sommersacher P, Shiehnejadhesar A, Mehrabian R, Hochenauer C, Scharler R. CO/CO2 Ratio in biomass char oxidation. INFUB 2017, 11th European Conference on Industrial Furnace and Boilers. 18-21 April 2017, Albufeira, Portugal.
External Link Details AbstractThe CO/CO2 release ratio obtained during char combustion of single biomass particles has been analysed in this work experimentally and by modelling. Experiments have been conducted with spruce, straw and Miscanthus pellets at different temperatures. Furthermore, these experiments have been modelled with a single particle model coupled with a CFD model of the single particle reactor. The results show that the CO/CO2 ratio strongly depends on the feedstock, being lower for spruce than for straw or Miscanthus. Furthermore, the most commonly employed correlations for this ratio in literature are not adequate, as they either under- or over-predict it.
Other Publications | 2017
Comparison of selected firelighters for stoves from renewable and fossil fuels in terms of gaseous emissons
Matschegg D, Kirchhof JM, Golicza L, Schwabl M, Schmidl C. Comparison of selected firelighters for stoves from renewable and fossil fuels in terms of gaseous emissons. 5th Central European Biomass Conference (Poster). January 2017, Graz, Austria.
DetailsPeer reviewed papers | 2017
CPFD simulations of an industrial-sized dual fluidized bed steam gasification system of biomass with 8 MW fuel input
Kraft S, Kirnbauer F, Hofbauer H. CPFD simulations of an industrial-sized dual fluidized bed steam gasification system of biomass with 8 MW fuel input. Applied Energy. 15 March 2017;190: 408-420.
External Link Details AbstractDual fluidized bed (DFB) systems for biomass gasification consist of two connected fluidized beds with a circulating bed material in between. Inside such reactor systems, rough conditions occur due to the high temperatures and the movement of the bed material. Computational fluid dynamics calculations are a useful tool for investigating fluid dynamics inside such a reactor system. In this study, an industrial-sized DFB system was simulated with the commercial code CPFD Barracuda. The DFB system is part of the combined heat and power (CHP) plant at Güssing, situated in Austria, and has a total fuel input of 8 MWth. The model was set up according to geometry and operating data which allows a realistic description of the hot system in the simulation environment. Furthermore, a conversion model for the biomass particles was implemented which covers the drying and devolatilization processes. Homogeneous and heterogeneous reactions were considered. Since drag models have an important influence on fluidization behavior, four drag models were tested. It was found that the EMMS drag model fits best, with an error of below 20%, whereas the other drag models produced much larger errors. Based on this drag law, further simulations were conducted. The simulation model correctly predicts the different fluidization regimes and pressure drops in the reactor system. It is also able to predict the compositions of the product and flue gas, as well as the temperatures inside the reactor, with reasonable accuracy. Due to the results obtained, Barracuda seems suitable for further investigations regarding the fluid mechanics of such reactors.
Peer reviewed papers | 2017
Cyanobacterial PHA Production—Review of Recent Advances and a Summary of Three Years’ Working Experience Running a Pilot Plant
Troschl C, Meixner K, Drosg B. Cyanobacterial PHA Production—Review of Recent Advances and a Summary of Three Years’ Working Experience Running a Pilot Plant. Bioengineering. 28 March 2017;4(2), 26.
External Link DetailsPeer reviewed papers | 2017
Development and experimental validation of a water gas shift kinetic model for Fe-/Cr-based catalysts processing product gas from biomass steam gasification.
Kraussler M, Hofbauer H. Development and experimental validation of a water gas shift kinetic model for Fe-/Cr-based catalysts processing product gas from biomass steam gasification. Biomass Conversion and Biorefinery. Volume 7, Issue 2, 1 June 2017, Pages 153-165
External Link DetailsPeer reviewed papers | 2017
Effect of draught conditions and ignition technique on combustion performance of firewood roomheaters
Reichert G, Hartmann H, Haslinger W, Öhler H, Mack R, Schmidl C, Schön C, Schwabl M, Stressler H, Sturmlechner R, Hochenauer C. Effect of draught conditions and ignition technique on combustion performance of firewood roomheaters. Renewable Energy. 1 May 2017;105: 547-560.
External Link Details AbstractFirewood roomheaters are popular, widespread and important for reaching European CO2 emission targets. Since they contribute significantly to local air pollution, they have to be optimized towards minimal emission release, especially in real-life operation. Draught conditions and user behavior, particularly the ignition technique, significantly affect the emission and efficiency performance of firewood roomheaters. This study assessed the effects of the respective parameters experimentally. The results revealed a clear correlation between draught conditions and thermal efficiency. Increased draught conditions up to 48 Pa significantly decreased thermal efficiency by 6%–11% absolutely. However, for gaseous emissions no clear trend was observed. Accordingly, CO and OGC emissions increased at higher draught conditions for one tested roomheater by 30% and 60%, but decreased for two other tested roomheaters by 13%–45%. For PM emissions no effect of increased draught conditions was evident. Top-down ignition technique did not lead to a significant decrease of PM emissions compared to bottom-up ignition. In contrast, bottom-up ignition led to best thermal efficiencies. The use of either spruce or beech as kindling material revealed no significant relevance for the ignition performance.
Conference presentations and posters | 2017
Effizienzsteigerung und Optimierung des Zusammenspiels von Scheitholzkessel, Pufferspeicher und Solaranlage durch die Verwendung mathematischer Modelle
Schulz J, Zemann C, Gölles M. Effizienzsteigerung und Optimierung des Zusammenspiels von Scheitholzkessel, Pufferspeicher und Solaranlage durch die Verwendung mathematischer Modelle. 5th Central European Biomass Conference (oral presentation). January 2017, Graz, Austria.
DetailsPeer reviewed papers | 2017
Emission factor assessment for two firewood stoves in the autumn or spring season
Sturmlechner R, Stressler H, Schwabl M, Reichert G, Carlon E, Haslinger W, Schmidl C, Weissinger A. Emission factor assessment for two firewood stoves in the autumn or spring season. 25th International Conference on Modelling, Monitoring and Management of Air Pollution. 25-27 April 2017.
External Link Details AbstractThis study analyses the emission factors of two firewood room heaters under testing conditions which emulate real life operation. A 6.5 kW stove with low heat storage capacity and high leakage rate (stove A) is compared with an 8 kW air-tight stove with high heat storage capacity (stove B). Thermal efficiency, carbon monoxide (CO) and organic gaseous compound (OGC) emissions, as well as the thermal heat losses (THL) during cool down phase were investigated in a series of laboratory tests. Furthermore, the influence of closing the air supply dampers at the end of the heating cycle was evaluated. Test results for the whole test cycle (including cool down phase) showed that stove A had CO emissions of 2633 mg/MJOutput and OGC emissions of 203 mg/MJOutput, while stove B had CO emissions of 2408 mg/MJOutput and OGC emissions of 109 mg/MJOutput, when air dampers were closed. It was also found that user behaviour has a critical influence on the stoves’ performance. Closing the air supply dampers at the end of the stove operation improved the efficiency by up to 5.0 percentage points. Furthermore, the duration of the cool down phase increased, as well as CO and OGC emissions decreased. As a matter of fact, measures to improve the user behaviour as for example user trainings and accurate manuals are of major importance in order to decrease emissions and increase efficiency of domestic heating appliances. Moreover, real life emission factors of other technologies should be established in order to develop a database which can be applied in air quality dispersion models.
Peer reviewed papers | 2017
Environmental trade-offs between residential oil-fired and wood pellet heating systems: forecast scenarios for Austria until 2030
Karner K, Kristöfel C, Enigl M, Strasser C, Schmid E. Environmental trade-offs between residential oil-fired and wood pellet heating systems: forecast scenarios for Austria until 2030. Renewable & Sustainable Energy Reviews. December 2017;80: 868-879.
External Link DetailsConference presentations and posters | 2017
ErgoS – Energierückgewinnung durch offene Sorption für Biomassefeuerungsanlagen
Höftberger E, Riepl R, Hebenstreit B, Golicza L, Paar EK, Goritschnig M, Zweiler R, Hochenauer C. ErgoS – Energierückgewinnung durch offene Sorption für Biomassefeuerungsanlagen. Güssing 17 Konferenz. March 2017, Güssing, Austria.
DetailsPeer reviewed papers | 2017
Estimation of binary diffusion coefficients in supercritical water - A mini review
Kraft S, Vogel F. Estimation of binary diffusion coefficients in supercritical water - A mini review. Industrial & Engineering Chemistry Research. 26 April 2017;56(16): 4847-4855.
External Link Details AbstractDiffusion coefficients of various solutes in supercritical water, which were either measured or retrieved from Molecular Dynamics simulations, were reviewed. Diffusion coefficients of molecules relevant for supercritical water processes were calculated with correlations reported in the literature and compared to the values of reference data. For conditions well above the critical point of water the simple Stokes-Einstein equation predicts the diffusion coefficients with an accuracy better than 20%. For conditions near the critical point the Wilke-Chang correlation gives the most accurate results. Diffusion coefficients for typical molecules occurring in supercritical water processes such as O2, N2, CO, CO2, or CH4 are estimated to be in the range of 60 · 10⁻⁹ m²/s at 673 K and 30 MPa. For H2, for which no experimental data are available, much higher diffusion coefficients in the range of 250 · 10⁻⁹ m²/s seem plausible. The data set of binary diffusion coefficients in supercritical water, either determined experimentally or by Molecular Dynamics simulations, should be extended significantly to include more solutes, as well as higher temperatures and pressures.
Conference presentations and posters | 2017
Evaluation of the Combustion Behaviour of Straw, Poplar and Maize in a Small-Scale Biomass Boiler
Kelz J, Zemann C, Muschick D, Krenn O, Hofmeister G, Weissinger A, Gölles M. & Hochenauer C. Evaluation of the Combustion Behaviour of Straw, Poplar and Maize in a Small-Scale Biomass Boiler. Proceedings 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden. p. 1958-1966
External Link Details AbstractIn order to evaluate the combustion behaviour of new biomass feedstocks such as short rotation coppice (poplar wood chips), fuels from agriculture (wheat straw pellets) and biomass residues (maize spindle grits), comprehensive test runs investigating both particulate matter (PM) and gaseous emissions were performed. A commercially available small-scale biomass boiler, especially designed to enable high fuel flexibility, was used for this evaluation. The combustion behaviour was determined for various boiler load conditions and primary air ratios while maintaining a constant total air ratio. Based on wet chemical analyses of the fuels, fuel indexes were calculated to deliver primary information on the combustion behaviour to be expected. During the test runs appropriate operating conditions were determined for these new biomass feedstocks in order to optimise combustion parameters and to minimise PM and gaseous emissions as well as to inhibit ash related problems (slagging, ash deposit formation and corrosion). The optimisation of operating conditions by primary measures showed a big potential for a stable boiler operation combined with reduced emissions. The findings provide the basis for a further development of combustion systems as well as control systems for the combustion of new biomass feedstocks.