PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 10, Number 2, 2024
comply with the discharging norms. Under the optimum aeration rate of 10h −1 , the obtained calculation accuracies of CO 2 and N 2 O emissions were 94.6% and 91.1%, respectively. The mean total GHG emission in the WWTP of paper mill was 550kg CO 2 - eq·h −1 , of which 44.6% came from the on-site emission sources and 55.4% from the off- site emission sources. It was also uncovered that the electrical consumption for aeration was the largest contributor to the total GHG emissions with a proportion of 25.2%, revealing that the control strategy of the aeration rate is highly significant in reducing GHG emissions in WWTP of paper mills. WOOD PANEL “Characterization of randomly oriented strand boards manufactured from juvenile wood of underutilized wood species”, Tomáš Pipíška, Marek Nociar, Pavel Král, Jozef Ráheľ, Pavlo Bekhta, Roman Réh, Ľuboš Krišťák, Miroslav Jopek, Barbora Pijáková, Rupert Wimmer & Milan Šernek, European Journal of Wood and Wood Products , (2024). The wood-based panel industry in Europe, which is dominated by the use of Norway spruce, will face new challenges due to environmental changes and the bark-beetle calamity, which started a new era of forestry. To explore the possibility of replacing spruce with other wood species, juvenile wood of nine underutilized wood species (Scots pine, European larch, poplar, willow, alder, birch, European beech, English oak and hornbeam) were used to make randomly oriented strand boards (OSBs). Single- layer OSBs were produced with 3% pMDI resin and 0.5% wax. Standard physical and mechanical properties were measured. The bending strength (MOR) values showed that there was no statistically significant difference between the values for, on the one hand, spruce (34.6MPa) and, on the other, larch (25.9MPa), poplar (25.2MPa), willow (27.8MPa), alder (34.3MPa) or birch (27.1MPa). A similar trend was found for the boards modulus of elasticity (MOE). The highest MOE values of 5,185MPa and 4,472MPa were found for spruce and alder, respectively. There was no significant difference between spruce and other wood species in internal bond strength. Boards made from high-density wood species showed better physical performance, whereas those made from low-density wood species (except pine) gave better mechanical properties. Strand-generalized characteristics, such as the slenderness ratio and specific surface, were analyzed for all investigated physical and mechanical properties. European larch, poplar, willow, and alder are potential wood species for manufacturing OSBs in future without mixing species, as they can replace spruce in the wood-based panel industry. “Sensitivity study of measured wooden board thermal properties on solid heat transfer model predictions”, Vojtěch Šálek, Lucie Hasalová, Vojtěch Štejfa, Adam Pivák, Petr Hejtmánek, Jiří Ira & Milan Jahoda, Fire Safety Journal , Vol.143, February 2024, 104055. This work presents experimental investigation on specific heat capacity and thermal conductivity as a function of temperature and vertical density profile over the sample cross section of oriented strand board, particle board, medium density fibreboard, and plywood. A possibility of introducing an universal set of parameters describing various EWPs by averaging the parameters of the four studied materials obtained in this work is investigated. A one-dimensional heat transfer simulation sensitivity study is performed using the experimentally measured values. The study aims to investigate the effect of using spatial- and temperature-dependent properties compared to constant values and to study the importance of these parameters and their combination in predicting one- dimensional heat transfer below the thermal decomposition temperature of engineered wood products.
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Technical Abstracts
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