BEST
Bioenergy and
Sustainable Technologies
Publications
Peer reviewed papers | 2015
Implementation of a firebed cooling device and its influence on emissions and combustion parameters at a residential wood pellet boiler
Gehrig M, Pelz SK, Jaeger D, Hofmeister G, Groll A, Thorwarth H, Haslinger W. Implementation of a firebed cooling device and its influence on emissions and combustion parameters at a residential wood pellet boiler. Applied Energy. 01 December 2015;159: 310-316.
This study investigates the general concept of reduced firebed temperatures in residential wood pellet boilers. Residential wood pellet boiler development is more and more concerned with inorganic aerosols characterized by a temperature-dependent release from the firebed. Hence, different concepts are applied aiming to reduce firebed temperatures. Unfortunately, these concepts influence not only firebed temperatures, but also other important parameters like air flow rates which may cause unwanted side effects with respect to combustion quality or efficiency. Thus, a new approach was developed solely affecting firebed temperature by implementing a water-based firebed cooling in a 12 kW underfeed pellet boiler. The effectiveness of the cooling was monitored by comprehensive temperature measurement in the firebed. The cooling capacity ranged from 0.4 kW to 0.5 kW resulted in a significant decrease of firebed temperatures. Gaseous emissions remain stable showing no significant changes in major components (O2, CO2, NOx). Furthermore, CO emissions were even reduced significantly by the activated cooling, which was supposedly caused by a stabilized devolatilization due to the firebed cooling. Moreover, the temperature-dependent release of aerosol forming elements was influenced at activated firebed cooling, which is proved by a decrease of 17 wt% of dust (Total Suspended Particles; TSP). At the same time the gaseous emissions of HCl increase, supposedly by a reduced potassium release from the firebed to the gas phase and a subsequently different particle formation. The general concept of reduced firebed temperatures proved to be successful decreasing overall aerosol emissions without impacting combustion quality.
Peer reviewed papers | 2015
Influence of bed material coatings on the water-gas-shift reaction and steam reforming of toluene as tar model compound of biomass gasification
Kuba M, Havlik F, Kirnbauer F, Hofbauer H. Influence of bed material coatings on the water-gas-shift reaction and steam reforming of toluene as tar model compound of biomass gasification. Biomass and Bioenergy. 7 August 2015;89:40-49
A promising technology replacing fossil energy carriers for the production of electricity, heat, fuels for transportation and synthetic chemicals is steam gasification of biomass in a dual fluid bed (DFB). The principle of this technology is the separation into a gasification and a combustion reactor. Bed material, nowadays olivine, circulates between them, and has two functions. It acts as a heat carrier from the combustion to the gasification zone and as catalyst regarding gasification reactions. Today, an alternative to olivine does yet not exist.
In this work, experiments in a lab-scale test rig were performed investigating the catalytic activity of different fresh and used bed materials, such as olivine and quartz. The enhancement of the catalytic activity due to particle coatings was tested regarding the water-gas-shift reaction and steam reforming of toluene. Calcite is known as an active material in this respect and is therefore used as a benchmark substance.
Experiments revealed a correlation between the catalytic activity of bed particle coatings towards both the water-gas-shift reaction and the reduction of toluene by steam reforming. Results showed bed material particles with a calcium (Ca)-rich layer achieve satisfactory conversion of carbon monoxide and reduction of toluene. Furthermore, a qualitative comparison regarding hydrogen production relative to the benchmark material CaO is given for the water-gas-shift and steam reforming of toluene and ethene - used as model substance for lighter hydrocarbons. These results are the basis for further research on the catalytic properties of potential bed materials for DFB gasification of biomass.
Other papers | 2015
Influence of ethylene on the formation of mixed alcohols over a MoS2 catalyst using biomass-derived synthesis gas
Weber G, Rauch R, Hofbauer H. Influence of ethylene on the formation of mixed alcohols over a MoS2 catalyst using biomass-derived synthesis gas. Biomass Conversion and Biorefinery. 2015;5(1):85-94.
Conference presentations and posters | 2015
Innovative room heating technologies
Schmidl C. Innovative room heating technologies, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
Conference presentations and posters | 2015
Integration of Oxidative Honeycomb Catalysts in Firewood Stoves - Perfomance Analysis, Safety Aspects and Long Term Durability
Reichert G, Schmidl C, Schwabl M, Stressler H, Sturmlechner R, Haslinger W. Integration of Oxidative Honeycomb Catalysts in Firewood Stoves - Perfomance Analysis, Safety Aspects and Long Term Durability, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
Peer reviewed papers | 2015
Investigation of the corrosion behaviour of 13CrMo4-5 for biomass fired boilers with coupled online corrosion and deposit probe measurements
Gruber T, Schulze K, Scharler R, Obernberger I. Investigation of the corrosion behaviour of 13CrMo4-5 for biomass fired boilers with coupled online corrosion and deposit probe measurements. Fuel. 2015;144:15-24.
High-temperature corrosion in biomass fired boilers is still an insufficiently explored phenomenon which causes unscheduled plant shutdowns and hence, economical problems. To investigate the high-temperature corrosion and deposit formation behaviour of superheater tube bundles, online corrosion probe as well as deposit probe measurements have been carried out in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Forest wood chips and quality sorted waste wood (A1-A2 according to German standards) as relevant fuels have been selected to investigate the influence on the deposit formation and corrosion behaviour. The following influencing parameter variations have been performed during the test campaigns: flue gas temperature between 650 and 880°C, steel temperature between 450 and 550°C and flue gas velocity between 2 and 8 m/s. One focus of the work presented is the detailed investigation of the structure and the chemical composition of the deposits formed as well as of the corrosion products. A further goal of the work presented was the development of an empirical model which can be used within CFD simulations of flow and heat transfer to calculate and evaluate the local corrosion potential of biomass fired plants already at the planning stage. The corrosion probe measurements show a clear dependency on the parameters investigated and the empirical function developed reproduces the measured corrosion behaviour sufficiently accurate. Since the additional calculation time within the CFD simulation is negligible the model represents a helpful tool for plant designers to estimate whether high-temperature corrosion is of relevance for a certain plant or not, when using fuels with similar compositions and the steel 13CrMo4-5. © 2014 Elsevier Ltd. All rights reserved.
Other papers | 2015
Investigations on the catalytic activity of bed material coating regarding the water-gas-shift reaction and the steam reforming of model compounds for lighter and heavier hydrocarbons
Kuba M, Havlik F, Kirnbauer F, Hofbauer H. Investigations on the catalytic activity of bed material coating regarding the water-gas-shift reaction and the steam reforming of model compounds for lighter and heavier hydrocarbons. 23rd European Biomass Conference & Exhibition (oral presentation). June 2015, Vienna, Austria.
Other Publications | 2015
Life cycle analysis of small scale pellet boilers characterized by high efficiency and low emissions
Monteleone B, Chiesa M, Marzuoli R, Verma VK, Schwarz M, Carlon E, Schmidl C, Ballarin Denti A. Life cycle analysis of small scale pellet boilers characterized by high efficiency and low emissions. Applied Energy. 1 October 2015;155:160-170.
Other papers | 2015
Liquid biofuels from biomass steam gasification
Rauch R. Liquid biofuels from biomass steam gasification. 23rd European Biomass Conference & Exhibition, side event Austrian Day (oral presentation). June 2015, Vienna, Austria.
Conference presentations and posters | 2015
Long-Term Monitoring of Pellet Boilers Installed in Residential Buildings: Efficiency and Operational Behaviour
Carlon E, Schwarz M, Verma VK, Schmidl C, Baratieri M. Long-Term Monitoring of Pellet Boilers Installed in Residential Buildings: Efficiency and Operational Behaviour, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
Conference presentations and posters | 2015
Mathematical model of an absorption based flue gas heat recovery
Hebenstreit B, Lichtenegger K, Schnetzinger R, Höftberger E, Schmidl C, Lundgren J, Toffolo A. Mathematical model of an absorption based flue gas heat recovery, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (visual presentation)
Conference presentations and posters | 2015
Mikrobielle Kontamination als Ursache für Fehlgerüche bei der Lagerung von Holzpellets
Pöllinger-Zierler P, Sedlmayer I, Reinisch C, Siegmund B, Wopienka E, Pointner C, Haslinger W. Mikrobielle Kontamination als Ursache für Fehlgerüche bei der Lagerung von Holzpellets, European Pellet Conference 2015, 25th-26th of Feburary 2015, Wels, Austria.
Conference presentations and posters | 2015
Model based control of a biomass fired steam boiler
Zemann C, Unterberger V, Gölles M. Model based control of a biomass fired steam boiler. 19. Steirisches Seminar über Regelungstechnik und Prozessautomatisierung. September 2015, Wagna, Austria.
Other Publications | 2015
Modellbildung und Regelung von Biomasse-Feuerungsanlagen
Schörghuber, C. Modellbildung und Regelung von Biomasse-Feuerungsanlagen, Ph.D. Thesis, Technische Universität Graz, Graz, Austria, 2015.
Conference presentations and posters | 2015
Nachhaltige Versorgungs und Wertschöpfungsketten
Strasser C. Nachhaltige Versorgungs und Wertschöpfungsketten, "Biomasse der Zukunft" - Internationale Konferenz auf Schloss Weinzierl 2015, 29th of Januar 2015, Wieselburg, Austria.
Conference presentations and posters | 2015
Natural ventilation measures for CO off-gassing in small pellet storages
Emhofer W, Lichtenegger K, Haslinger W, Sedlmayer I. Natural ventilation measures for CO off-gassing in small pellet storages, Word Sustainable Energy Days next 2015, 24th-27th of February 2015, Wels, Austria.
Other papers | 2015
Numerical modelling of biomass grate furnaces with a particle based model
Mehrabian R, Shiehnejadhesar A, Scharler R, Obernberger I. Numerical modelling of biomass grate furnaces with a particle based model, INFUB 10th European Conference on Industrial Furnace and Boilers 2015, 7th-10th of April 2015, Porto, Portugal.
Reports | 2015
Nutrient recovery by biogas digestate processing
Drosg B, Fuchs W, Al Seadi T, Madsen M, Linke B. Nutrient recovery by biogas digestate processing. IEA Bioenergy (2015): 7-11
Conference presentations and posters | 2015
Operation and Efficiency of a Wood-Pellet Fired 5 KWel Stirling
Aigenbauer S, Schnetzinger R, Höftberger E, Schmidl C, Haslinger W. Operation and Efficiency of a Wood-Pellet Fired 5 KWel Stirling, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (visual presentation)
Peer reviewed papers | 2015
Optimization of a 50 MW bubbling fluidized bed biomass combustion chamber by means of computational particle fluid dynamics
Kraft S, Kuba M, Kirnbauer F, Bosch K, Hofbauer H. Optimization of a 50 MW bubbling fluidized bed biomass combustion chamber by means of computational particle fluid dynamics. Biomass and Bioenergy. 4 August 2015;89:31-39.
An efficient utilization of biomass fuels in power plants is often limited by the melting behavior of the biomass ash, which causes unplanned shutdowns of the plants. If the melting temperature of the ash is locally exceeded, deposits can form on the walls of the combustion chamber. In this paper, a bubbling fluidized bed combustion chamber with 50 MW biomass input is investigated that severely suffers deposit build-up in the freeboard during operation. The deposit layers affect the operation negatively in two ways: they act as an additional heat resistance in regions of heat extraction, and they can come off the wall and fall into the bed and negatively influence the fluidization behavior. To detect zones where ash melting can occur, the temperature distribution in the combustion chamber is calculated numerically using the commercial CPFD (computational particle fluid dynamics) code, Barracuda Version 15. Regions where the ash melting temperature is exceeded are compared with the fouling observed on the walls in the freeboard. The numerically predicted regions agree well with the observed location of the deposits on the walls. Next, the model is used to find an optimized operating point with fewer regions in which the ash melting temperature is exceeded. Therefore, three cases with different distributions of the inlet gas streams are simulated. The simulations show if the air inlet streams are moved from the freeboard to the necking area above the bed a more even temperature distribution is obtained over the combustion chamber. Hence, the areas where the ash melting temperatures are exceeded are reduced significantly and the formation of deposits in the optimized operational mode is much less likely.
Conference presentations and posters | 2015
Outlook for the Project: Future Application and Development of the AshMelT methods
Schwabl M, Wopienka E. AshMelT Workshop “Outlook for the Project: Future Application and Development of the AshMelT methods” (held during de World Sustainable Energy Days 2015), 25th-27th of February, Wels, Austria, 2015.
Conference presentations and posters | 2015
Parameter Study with Sulfidized Molybdenum Catalyst for Mixed Alcohol Synthesis with Biomass-Derived Synthesis Gas
Weber G, Rauch R, Hofbauer H. Parameter Study with Sulfidized Molybdenum Catalyst for Mixed Alcohol Synthesis with Biomass-Derived Synthesis Gas, 23rd European Biomass Conference 2015, 1st-4th of June 2015, Vienna, Austria. (oral presentation)
Peer reviewed papers | 2015
Performance of a water gas shift pilot plant processing product gas from an industrial scale biomass steam gasification plant
Kraussler M, Binder M, Fail S, Bosch K, Hackel M, Hofbauer H. Performance of a water gas shift pilot plant processing product gas from an industrial scale biomass steam gasification plant. Biomass and Bioenergy. 4 August 2015;89:50-57.
In this paper, the performance of a commercial Fe/Cr based catalyst for the water gas shift reaction was investigated. The catalyst was used in a water gas shift pilot plant which processed real product gas from a commercial biomass steam gasification plant with two different qualities: extracted before and extracted after scrubbing with a rapeseed methyl ester gas scrubber. The performance of the WGS pilot plant regarding these two different gas qualities was investigated. For this reason, extensive chemical analyses were carried out. CO, CO2, CH4, N2, O2, C2H6, C2H4, and C2H2 and H2S, COS, and C4H4 S were measured. In addition, GCMS tar and NH3 analyses were performed. Furthermore, the catalyst's activity was observed by measuring the temperature profiles along the reactors of the water gas shift pilot plant. During the 200 h of operation with both product gas qualities, no catalyst deactivation could be observed. A CO conversion up to 93% as well as a GCMS tar reduction (about 28%) along the water gas shift pilot plant was obtained. Furthermore, a specific H2 production of 63 g H2 per kg biomass (dry and ash free) was reached with both product gas qualities. No significant performance difference could be observed.
Other papers | 2015
Performance of a water gas shift pilot plant processing tar-rich product gas from a commercial biomass steam gasification plant operating at partial load conditions
Kraussler M, Binder M, Hofbauer H. Performance of a water gas shift pilot plant processing tar-rich product gas from a commercial biomass steam gasification plant operating at partial load conditions. International Bioenergy Exhibition and Asian Bioenergy Conference 2015. October 2015, Shanghai, China.
Other papers | 2015
Performance of a Water Gas Shift Unit Processing Product Gas from Biomass Steam Gasification
Kraussler M, Binder M, Fail S, Rauch R, Bosch K, Hackel M, Hofbauer H. Performance of a Water Gas Shift Unit Processing Product Gas from Biomass Steam Gasification. 23rd European Biomass Conference & Exhibition (oral presentation). June 2015, Vienna, Austria.