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The aim of the study was to determine the variability of annual ring width, share of latewood, density and compression strength along the grain of "Tab"rz" Scots pine wood (Pinus sylvestris L.). The wood samples for examination were obtained from three trunks of 260-year-old Scots pines felled in the Sosny Taborskie Nature Reserve. In total, 106 samples were obtained, with cross-sectional dimensions of 20 x 20 mm and a length of 30 mm along the grain. The mean values for all tested wood samples were as follows: annual ring width 1.28 mm, share of latewood 28.9%, wood density 0.487 g·cm-3, and compression strength 47.3 MPa. The least variability within trees was found for wood density and compressive strength along the grain. Very high positive correlation was found between wood density and compressive strength, and high positive correlations were found between share of latewood and wood density and between share of latewood and compressive strength. To the authors' knowledge, the results presented here are the first empirical data published concerning the features of wood macrostructure, density and compression strength along the grain of the Tabórz Scots pine, the trunks of which are considered a valuable timber in Europe. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on variability in the static bending strength of the "Tabórz" Scots pine wood (Pinus sylvestris L). The wood samples for examination were obtained from the trunks of 260-year-old Scots pines felled in the "Sosny Taborskie " Nature Reserve. The mean value for all the tested wood samples amounted to 77.3 MPa, whereas for the individual trunks it reached 105.3 MPa, 66.4 MPa and 60.1 MPa, respectively. It is believed that the research results presented here are the first empirical data published concerning the mechanical properties of the wood of the "Tabórz" Scots pine, the trunks of which, due to their high quality, are considered in Europe to be extremely valuable timber. [ABSTRACT FROM AUTHOR]

The process of biomass compaction depends on many factors, related to material and process. One of the most important is the proper fragmentation of the raw material. In most cases, more fragmented raw material makes it easier to achieve the desired quality parameters of pellets or briquettes. While the chipping of biomass prefers moist materials, for grinding, the material needs to be dried. As drying temperature changes the properties of the material, these may affect the grinding process. The aim of this work was to determine the influence of the drying temperature of biomass raw material in the range of 60–140 °C on the biomass grindability. To only determine this effect, without the influence of moisture, grinding was carried out on the material in a dry state. The research was carried out on a mill with a knife and hammer grinding system, which is the most popular in the fragmentation of biomass. The analysis of particle size distribution and bulk density of the obtained material was carried out. The energy demand for the grinding process was determined and it was shown that drying temperature, grinding system, and mainly type of biomass affects the grindability. [ABSTRACT FROM AUTHOR]

For biomass compaction, it is important to determine all aspects of the process that will affect the quality of pellets and briquettes. The low bulk density of biomass leads to many problems in transportation and storage, necessitating the use of a compaction process to ensure a solid density of at least 1000 kg·m−3 and bulk density of at least 600 kg·m−3. These parameters should be achieved at a relatively low compaction pressure that can be achieved through the proper preparation of the raw material. As the compaction process includes a drying stage, the aim of this work is to determine the influence of the drying temperature of pine biomass in the range of 60–140 °C on the compaction process. To determine whether this effect is compensated by the moisture, compaction was carried out on the material in a dry state and on the materials with moisture contents of 5% and 10% and for compacting pressures in the 130.8–457.8 MPa range. It was shown that drying temperature affects the specific density and mechanical durability of the pellets obtained from the raw material in the dry state, while an increase in the moisture content of the raw material neutralizes this effect. [ABSTRACT FROM AUTHOR]