Time filter

Source Type

Vienna, Austria

Sikkema R.,University Utrecht | Junginger M.,University Utrecht | Pichler W.,Holzforschung Austria | Hayes S.,National Energy Foundation NEF | Faaij A.P.C.,University Utrecht
Biofuels, Bioproducts and Biorefining

The European wood pellet market is booming: concerns about climate change and renewable energy targets are predominant drivers. The aim of this analysis is to compare typical wood pellet chains from the purchase of the feedstock from sawmills to the conversion into heat or electricity. Cost structures, primary energy inputs and avoided greenhouse gas (GHG) emissions are reviewed. Three cases are defined: pellets for district heating (DH) in Sweden (replacing heavy fuel oil); bagged pellets for residential heating in Italy (natural gas); and Canadian pellets for electricity production in the Netherlands (coal). Supply may cost €110-€170 per tonne of delivered pellets, with the main cost factors being feedstock collection, drying and long-distance ocean transportation (for Canadian pellets only). Largest avoided emissions are for power production (1937 kg CO2eq/tonne of pellets), followed by district heating (1483 kg). In relative terms, the GHG reduction varies from 81% for residential heating (with pre-dried feedstock) to 97% for DH. Based on a wood-pellet consumption of 8.2 million tonnes, the EU27 plus Norway and Switzerland avoided about 12.6 million tonnes of CO2 emissions in 2008. Concluding, wood pellets can achieve substantial GHG savings, especially when substituting coal for power production. However, wood pellets are relatively expensive, especially compared to coal. Only in the case of high oil prices, can the substitution of heating oil for DH be commercially viable. In most other cases, substitution is only possible with financial support from national governments, for example, feed-in tariffs or carbon taxes. The commercial markets for CO2 emission rights may cover some costs, but their impact is still limited. © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd. Source

Stefko J.,Technical University In Zvolen | Bednar J.,Holzforschung Austria
Key Engineering Materials

The paper deals with laboratory air tightness testing of wood based construction materials with the focus on the proportion of air infiltration through the building envelope in the air exchange of the building. Results of the specific materials testing - cross laminated timber (CLT), OSB and other structural materials are analysed in the paper. Moreover, the effect of production technology, material, its thickness and surface treatment are studied. Results of laboratory testing provide valuable data for detailed computer modelling of air exchange through the infiltration, especially in vapour diffusion-open elements of building envelope. © 2016 Trans Tech Publications, Switzerland. Source

Forsthuber B.,Holzforschung Austria | Muller U.,Wood us Competence Center for Wood Composites and Wood Chemistry | Teischinger A.,University of Natural Resources and Life Sciences, Vienna | Grull G.,Holzforschung Austria
Polymer Degradation and Stability

In this study, we hypothesized that the use of UV absorber of the hydroxy-benzotriazole class (BTZ) and micronized TiO2 (NTiO 2) as mineral UV screener could stabilize the chemical and mechanical properties of clear wood coatings based on a high Tg/low T g multiphase acrylic binder dispersion. The photooxidation rates were compared using ATR-FTIR techniques and tension tests. For qualitative and quantitative chemical analysis and correlation to the mechanical properties, multiple linear regression (MLR) was used, which was a suitable method to monitor the chemical changes of the polymeric binder and to investigate the influence of these light stabilizing additives on the photooxidation behavior. The analysis of mechanical properties of the acrylic binder during exposure to Xenon arc light showed that both BTZ and NTiO2 stabilized the Young's Modulus and the elongation at break during the whole cycle. BTZ showed better results. However, it led to a strong decrease of the initial Young's Modulus whereas NTiO2 showed no comparable effect. We concluded that BTZ was very efficient in reducing the photooxidation and the accompanied change of the elastic properties of the acrylic binder. NTiO2 only stabilized the high Tg component of the multiphase acrylic binder whereas the photooxidation of the low Tg component was accelerated. This may be explained by a photocatalytical activity of NTiO2. © 2013 Elsevier Ltd. All rights reserved. Source

Denzler J.K.,Holzforschung Austria | Koppensteiner J.,Holzforschung Austria | Arthaber H.,Vienna University of Technology
International Wood Products Journal

An important aspect in machine strength grading of timber is the direction of the grain and deviations from the main axis, which can cause a dramatic loss of strength. Therefore, an essential requirement of the wood industry is to find the direction of wood fibres in a fast and noninvasive way. For three decades now the use of polarised microwave radiation has been investigated, revealing the main direction of wood fibres in a non-contact and non-destructive way. The development of new small sized patch antennas now allows the detection of grain deviations on a local scale using a free microwave transmission method. This paper presents experimental results on accuracy and resolution for spruce specimens of different dimensions. Local signal variations, as well as boundary effects are discussed, particularly in view of possible industrial implementation. © 2013 IWSc, the Wood Technology Society of the Institute of Materials, Minerals and Mining. Source

Dolezal F.,Holzforschung Austria | Spitzbart-Glasl C.,Holzforschung Austria
Energy Procedia

Several initiatives have been launched to increase sustainability in building industry. All of them contain a shift in focus from energy consumption to a wide variety of indicators for the full life cycle. This implies a broader view, not only based on the ecological, but on the economic and social performance of buildings as well. A closer look on internationally acting Green Building Labels reveals that acoustic performance and noise protection is seen as an important part of the social sustainability aspects of a building. Thus, the approach of how to consider the acoustic performance and impact on rating results vary heavily. © 2015 The Authors. Source

Discover hidden collaborations