Bioenergy2020 GmbH

Burgenland, Austria

Bioenergy2020 GmbH

Burgenland, Austria
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Kern S.,Vienna University of Technology | Halwachs M.,Bioenergy2020 GmbH | Kampichler G.,Energieversorgung Niederosterreich EVN AG | Pfeifer C.,Vienna University of Technology | And 2 more authors.
Journal of Analytical and Applied Pyrolysis | Year: 2012

The idea of co-firing biomass in an already existing coal-fired power plant could play a major contribution in the reduction of carbon dioxide emissions. Huge amounts of unused biomass in terms of agricultural residues such as straw, which is a cheap and local feedstock, are often available. But due to the high amount of corrosive ash elements (K, Cl, etc.), the residues are usually not suitable for co-firing in a thermal power plant. Therefore, the feedstock is converted by low temperature pyrolysis into gaseous pyrolysis products and charcoal. A 3 MW pyrolysis pilot plant located next to a coal-fired power plant near Vienna was set up in 2008. For the process, an externally heated rotary kiln reactor with a design fuel power of 3 MW is used which can handle about 0.6-0.8 t/h straw. The aim is to investigate the fundamentals for scale-up to the desired size for co-firing in a coal-fired power plant. In addition to the desired fuel for the process, which is wheat straw, a testing series for DDGS was also performed. The high amount of pyrolysis oil in the gas had positive effects on the heating value of the pyrolysis gas. Chemical efficiencies of this pyrolysis pilot plant of up to 67% for pyrolysis temperatures between 450°C and 600°C can be reached. The focus of this work is set on the pyrolysis products and their behavior at different pyrolysis temperatures as well as the performance of the pyrolysis process. © 2012 Elsevier B.V.


Rachbauer L.,Bioenergy2020 GmbH | Voitl G.,University of Natural Resources and Life Sciences, Vienna | Bochmann G.,University of Natural Resources and Life Sciences, Vienna | Fuchs W.,University of Natural Resources and Life Sciences, Vienna
Applied Energy | Year: 2016

The current study reports on biological biogas upgrading by means of hydrogen addition to obtain biomethane. A mesophilic (37 °C) 0.058 m3 trickle-bed reactor with an immobilized hydrogenotrophic enrichment culture was operated for a period of 8 months using a substrate mix of molecular hydrogen (H2) and biogas (36–42% CO2). Complete CO2 conversion (> 96%) was achieved up to a H2 loading rate of 6.5 mn 3 H2/m3 reactor vol. × d, corresponding to 2.3 h gas retention time. The optimum H2/CO2 ratio was determined to be between 3.67 and 4.15. CH4 concentrations above 96% were achieved with less than 0.1% residual H2. This gas quality complies even with tightest standards for grid injection without the need for additional CO2 removal. If less rigid standards must be fulfilled H2 loading rates can be almost doubled (10.95 versus 6.5 mn 3 H2/m3 reactor vol. × d) making the process even more attractive. At this H2 loading the achieved methane productivity was 2.52 mn 3 CH4/m3 reactor vol. × d. In terms of biogas this corresponds to an upgrading capacity of 6.9 mn 3 biogas/m3 reactor vol. × d. The conducted experiments demonstrate that biological methanation in an external reactor is well feasible for biogas upgrading under the prerequisite that an adequate H2 source is available. © 2016 Elsevier Ltd


Wilk V.,Bioenergy2020 GmbH | Schmid J.C.,Vienna University of Technology | Hofbauer H.,Vienna University of Technology
Biomass and Bioenergy | Year: 2013

An in-bed and an on-bed feeding system are implemented in a dual fluidized bed gasifier in order to investigate the influence of the fuel feeding position on the gasification process. Two bed materials, fresh and used olivine, are used because of their varying catalytic activity. The comparison of in-bed and on-bed feeding of wood pellets shows that in-bed feeding is more favorable, because lower tar concentrations are achieved and the gas composition is closer to water-gas shift equilibrium. Better mixing of bed material and fuel particles occurs with in-bed feeding. The residence time of the gas phase in the fluidized bed is longer in the case of in-bed feeding, and therefore better performance of the gasifier is achieved. Sufficient residence time of the fuel in the bubbling bed is important when a less active bed material is used. More active bed material is capable of compensating for the shorter residence time of the gas phase in contact with bed material during on-bed feeding. •Experimental investigation of in-bed and on-bed feeding.•Two bed materials (catalytic activity) and two fuels (devolatilization behavior).•In-bed feeding more favorable due to lower tar concentration and better gas quality.•Residence time of the gas phase in the fluidized bed is longer during in-bed feeding.•More active bed material compensates for shorter residence time of the gas phase. © 2013 Elsevier Ltd.


Wilk V.,Bioenergy2020 GmbH | Hofbauer H.,Vienna University of Technology
Fuel Processing Technology | Year: 2013

The influence of the distribution of fuel particle size on steam gasification was studied systematically in a dual fluidized bed gasifier. Pilot plant gasification experiments have been conducted using sawdust and pellets produced from the same raw material. Three different kinds of waste wood with a broad particle size distribution were also considered for comparison. The fuels differ in their content of particles smaller than 1 mm of equivalent diameter. With an increasing proportion of particles smaller than 1 mm, the product gas contained less H2 and more CO and CH4. Less product gas was generated and the concentration of tar increased. It is observed that entrainment of small fuel particles plays an important role in the dual fluidized bed gasifier. Based on the superficial gas velocity in the freeboard of the gasification reactor, a limiting diameter for the entrainment of fuel particles can be determined. Under the conditions investigated a total of 22 wt.% of fuel particles present in the mixture of sawdust and pellets was entrained very rapidly after feeding because of their size. They mainly devolatilize in the freeboard and only have limited contact with the catalytic bed material. Therefore, these volatiles are less likely to be reformed and more tar is found in the product gas. As a conclusion, the particle size determines the region where the thermal conversion of the fuel particle mainly takes place: within the fluidized bed or in the freeboard. © 2013 Elsevier B.V.


Wilk V.,Bioenergy2020 GmbH | Hofbauer H.,Vienna University of Technology
Energy and Fuels | Year: 2013

Co-gasification of biomass and plastics was investigated in a 100 kW dual fluidized-bed pilot plant using four types of plastic material of different origins and soft wood pellets. The proportion of plastics was varied within a broad range to assess the interaction of the materials. The product gas composition was considerably influenced by co-gasification, whereas the changes were nonlinear. More CO and CO2 were measured in the product gas from co-gasification than would be expected from linear interpolation of mono-gasification of the materials. Less CH4 and C2H 4 were formed, and the tar content in the product gas was considerably lower than presumed. With the generation of more product gas than expected, co-gasification of wood and plastic materials also had other beneficial effects. Because of the fuel mixtures, more radicals of different types were available that interacted with each other and with the fluidization steam, enhancing the reforming reactions. Wood char had a positive effect on polymer decomposition, steam reforming, and tar reduction. As a result of the more active splash zone during co-gasification of wood and plastics, contact between gas and bed material was enhanced, which is crucial for catalytic tar removal. © 2013 American Chemical Society.


Wilk V.,Bioenergy2020 GmbH | Hofbauer H.,Vienna University of Technology
Fuel | Year: 2013

Steam gasification of plastic materials was studied in a dual fluidized bed gasification pilot plant (DFB). Several types of plastics, which are available in large amounts in waste streams, were investigated: PE, PP, and mixtures of PE + PS, PE + PET and PE + PP. It was found that the product gas from PE was rich in CH4 and C2H4 and had a LCV of 25 MJ/N m 3. About 22% of PE was converted to the monomer C2H 4. Different mixtures of PE with other polymers showed, that the concentrations of CH4 and C2H4 increased with an increasing proportion of PE and that they were the main decomposition products of PE. The product gas from pure PP contained more CH4 and less C2H4 compared to the product gas from PE. The polymer mixtures behaved differently from the pure substances. Significantly more H2 and CO were generated from PE + PP and PE + PS. It can be assumed that the decomposition products of the two polymers in the mixture interacted strongly and alternately influenced the gasification process. More water was converted, so the gas production increased. The reforming reactions were enhanced and yielded H2 and CO at the expense of CH4 and C2H4. The mixture of PE + PET differed from the other polymers because of the high oxygen content of PET. Thus, 28% of CO2 were measured in the product gas. By contrast, CO2 was in the range of 8%, when oxygen-free polymers were gasified and CO2 was only produced from reactions with steam. Gasification of polymers resulted in significantly high tar loads in the product gas in the range of 100 g/N m 3. The GCMS analysis of tars showed that tars from polymers mainly consisted of PAH and aro-matics. Naphthalene was the most important tar compound. © 2013 Elsevier Ltd. All rights reserved.


Wilk V.,Bioenergy2020 GmbH | Hofbauer H.,Vienna University of Technology
Fuel | Year: 2013

During gasification, fuel nitrogen is converted into gaseous species, such as NH3, HCN and others. Several materials are gasified in the dual fluidized bed gasification pilot plant in order to assess the conversion of fuel nitrogen. The fuels tested in this study are different kinds of waste wood, bark and plastic residues. The nitrogen content of these materials ranges from 0.05 to 2.70 wt.-%. Detailed measurements of NH3, N2, HCN, NO and nitrogenous tars are carried out during the test runs. It is found that the vast majority of nitrogen is present in the form of NH3. There is a linear relationship with high accuracy between fuel nitrogen and NH 3 in the producer gas. The nitrogen balance of the dual fluidized bed gasification system shows the distribution of nitrogen in the two coupled reactors of the gasification system. It is assessed that nitrogen conversion occurs almost exclusively in the gasification reactor. Only minor amounts of nitrogen are found in the char, which is transported to the combustion reactor and is converted to NO there. This result provides important information for the gas cleaning requirements when nitrogen-rich fuels are gasified. © 2012 Elsevier Ltd. All rights reserved.


Wilk V.,Bioenergy2020 GmbH | Hofbauer H.,Vienna University of Technology
Fuel Processing Technology | Year: 2015

The performance of the dual fluidized bed gasification plant Oberwart was evaluated by means of an extensive measurement campaign and calculation of mass and energy balances using IPSEpro. Process simulation was also applied to identify future optimization potentials. Different aspects are discussed such as the reduction of gasification temperature and the reduction of steam for gasification and air for combustion. Gasification pilot plant experience is integrated in the simulation models to increase significance of the simulation results. The mass and energy balances confirm that the performance of the CHP plant Oberwart is highly satisfactory and currently achieves an electrical efficiency of 29%. The variations of plant parameters provide deeper insight in the process itself and show interdependencies of different process units. With lower gasification temperatures and reduction in combustion air, the electrical efficiency can be increased to 31%. © 2015 Elsevier B.V.


Emhofer W.,Bioenergy2020 GmbH | Emhofer W.,Vienna University of Technology | Lichtenegger K.,Bioenergy2020 GmbH | Haslinger W.,Bioenergy2020 GmbH | And 4 more authors.
Annals of Occupational Hygiene | Year: 2015

Wood 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 m3 h-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.


Rubio Rodriguez M.A.,University "Marta Abreu" of Las Villas | Feito Cespon M.,University "Marta Abreu" of Las Villas | De Ruyck J.,Vrije Universiteit Brussel | Ocana Guevara V.S.,University "Marta Abreu" of Las Villas | And 2 more authors.
Applied Energy | Year: 2013

The present paper introduces a life cycle modeling approach for representing actual demand of energy or energy intensive products delivered within a system (electricity, heat, etc.) for optimization of the energy mix, according to some of the available life cycle impact assessments (LCIAs). Unlike classical LCA modeling approach, the real amount of several energy products leaving the system and the interactions due to the presence of multi-output processes are considered within the present approach. As a case study, future scenarios are obtained for the Belgian electricity mix production and the heat mix potentially substituted by CHP or biomass, switching between abandoning or not power from nuclear energy. The possibility of using natural gas, biomass for cogeneration, wind power and solar photovoltaic energy are considered within the availability ranges of these resources. Finally, results are presented from successive optimizations according to the sustainability potential defined in a previous paper. A pathway to a more sustainable Belgian energy system is obtained. Finally it is concluded that under the modeling conditions and without nuclear energy it is not possible to obtain a reduction of GHGs and despite diminishing of non-renewable resource consumption, a rising of toxicity is obtained. © 2013 Elsevier Ltd.

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