The pine stems were cut from three different polluted environments – Ist trees degradation degree (weak pollution), IInd trees degradation degree (strong pollution) and IIIrd trees degradation degree (connected with very strong pollution). On the basis of obtained results it was stated that environmental pollution caused changes in late wood participation, as well as distribution of cellulose on the stem cross- and longitudinal section. It also changed cellulose content in bark from the butt-end section, which was about 26% regardless the degradation degree. The environmental pollution caused also an increase of viscometric average polymerization degree of cellulose in heartwood in relation to heartwood adjacent sapwood and sapwood from butt-end section. Regardless the degradation degree, cellulose polymerization degree in heartwood adjacent sapwood from the middle part of the stem was higher in comparison to sapwood and heartwood. Moreover, the environmental pollution caused the increase of viscometric average polymerization degree of cellulose in bark. The polymerization degree of cellulose in bark from the butt-end section of IIIrd degradation degree stems was 22% and 23% higher in comparison to the Ist and IInd degradation degree.

The aim of this study was to investigate the influence of biomass micronization on energy production using a converted aircraft turbine AI-20. The test system was constructed in such a way to ensure continuous operation for a given period of time and was equipped in a chopper, a flail mill, and a micronizer. The turbine had the ability to produce energy from solid biomass and as well conventional fuels. The most energy was obtained from absolutely dry sunflower husk (17.27 MJ/kg) and the least from Poplar (7.82 MJ/kg). Miscanthus, wheat straw, and hay (approximately 17 MJ/kg) showed high values of energy production. In addition, the thermal decomposition of wheat straw at 350 and 450 °C was studied using the Py-GC/MS technique in a helium atmosphere to determine the gaseous compounds formed during biomass gasification under anaerobic conditions. The results obtained indicate the formation of compounds classified as phenols (vanillin, hydroxymethylfurfural).

In this paper, the influence of physicochemical pretreatment methods on the chemical composition, enzymatic hydrolysis efficiency and porosity of fast-growing Populus trichocarpa wood was compared. Among the pretreatment methods, the liquid hot water (LHW) and steam explosion (SE) were used, which were performed at three different temperatures (160 °C, 175 °C and 190 °C) and two residence times (15 min and 1 h). The chemical composition, enzymatic hydrolysis and porosity analysis were done for native wood and solid fraction obtained after LHW and SE pretreatments. The porosity analysis was performed by inverse size exclusion chromatography method. Additionally, inhibitors of hydrolysis and fermentation processes in the liquid and solid fractions obtained after pretreatments were examined. Based on the results, it was found that the tested pretreatments caused the greatest changes in the chemical content of hemicelluloses. It was found that after LHW and SE pretreatments up to 99.1% or 94.0%, respectively, of hemicelluloses were removed from the obtained solid fraction. Moreover, the LHW and SE processes greatly enhanced the enzymatic digestibility of fast-growing poplar wood. The highest glucose yield was achieved after 15 min of SE pretreatment at 190 °C and was 676.4 mg/g pretreated biomass, while in the case of xylose the highest value (119.3 mg/g pretreated biomass) was obtained after 15 min of LHW pretreatment at 160 °C. Generally, after SE pretreatment process, more inhibitors were formed, and a greater effect of porous structure development was noticed than after LHW pretreatment. Despite this difference, the average glucose contents and yields after enzymatic hydrolysis of pretreated biomass were generally similar regardless of the pretreatment used.

The aim of this study was the investigation of the effect of growth conditions of energy willow (Salix viminalis L.) on its physical and chemical parameters towards lignocellulosic biofuels. This work is linked to the global trend of replacing fossil fuels (coal, oil, natural gas) with energy and renewable fuels. This energy transition is dictated by the reduction of the human-induced greenhouse effect (to the greatest extent by industrial development). Changing from traditional to renewable energy sources results in industry becoming less dependent on fuels whose sources are beginning to run out, and in energy processing being broken down into smaller sectors with greater flexibility to change and less susceptibility to failure. The use of lignocellulosic raw materials such as wood, straw, food industry waste, wood, and post-consumer products such as old furniture for energy purposes allows the use of substances which bind the greenhouse gas carbon dioxide in their cellular structure during growth. In order to optimise the costs of producing such energy and minimise its impact on the environment, these plants should be located as close as possible to the source of raw materials. One of the most important characteristics for the profitability of energy production from woody biomass is a high biomass yield. For this purpose, the raw material used for this study was energy willow (Salix viminalis L.) seedlings, which are often used for energy crops. Due to the moisture-loving nature of the substrate, the effect of the addition of the active substance prednisonum as a catalyst for water adsorption from the substrate was investigated. In order to determine the substances formed during the thermal decomposition of energy willow (Salix viminalis L.) wood, a pyrolysis process was carried out at 450 °C using pyrolysis gas chromatography mass spectrometry (PY/GC-MS).

Fast-growing poplar trees from plantations are the source of inexpensive wood that is intended mainly for chemical processing in the pulp and paper industry. Their potential as raw material for biofuel manufacturing is widely discussed as well. The detailed chemical composition of this raw material is therefore an important question. Five species of poplars were investigated: Populus alba, P. maximowiczii, P. trichocarpa, P. nigra, andP. tremula. Wood is a material consisting mainly of lignocellulose, but there are also many extractives. In temperate zone climate they typically represent up to 5% of wood mass. Their identification is difficult, due to various classes of compounds and great number of individual ones. These compounds can affect the properties of wood—its resistance to biotic agents and suitability to enzymatic treatment towards biofuels. Gas chromatography coupled with mass spectrometer (GC-MS) was used to analysis of extractives in various species of poplar wood. Compounds from several classes were identified like phenols, fatty acids, and their derivatives, sterols. Their identification was discussed along with estimation of their content in wood of investigated species.