Biomass utilization is vital for developing sustainability in the bioenergy sector. In this work the effects of high ash content on the heating properties of wood chips were evaluated. In an analysis of 450 wood chips samples, the ash content, moisture content, and gross calorific value were determined, and a generalized linear model was created to identify the relationship between the gross calorific value and the ash content of the wood chips. The mean ash content of the analyzed wood chips samples was 2.64%, the mean moisture content was 38.8%, and the mean gross calorific value was 19.43 MJ kg -1. Statistical analyses showed that 49% of the gross calorific value variability was due to the ash content variability. A one percent increase in ash content resulted in a 0.11 MJ kg -1 decrease of gross calorific value. The estimated costs of ash disposal at various ash contents were calculated. Burning wood chips with 5% ash content would lead to depositing an extra 5.6 megatons in the US or 21.2 megatons in the EU, compared to burning wood chips with 2.5% ash content.

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Commission ICWG I/VbKEY WORDS: Unmanned aerial vehicle, wood chips pile, DJI Phantom, photogrammetry ABSTRACT:The rapid development of unmanned aerial vehicles is a challenge for applied research. Many technologies are developed and then researcher are looking up for their application in different sectors. Therefore, we decided to verify the use of the unmanned aerial vehicle for wood chips pile monitoring. We compared the use of GNSS device and unmanned aerial vehicle for volume estimation of four wood chips piles. We used DJI Phantom 3 Professional with the built-in camera and GNSS device (geoexplorer 6000). We used Agisoft photoscan for processing photos and ArcGIS for processing points. Volumes calculated from pictures were not statistically significantly different from amounts calculated from GNSS data and high correlation between them was found (p = 0.9993). We conclude that the use of unmanned aerial vehicle instead of the GNSS device does not lead to significantly different results. Tthe data collection consumed from almost 12 to 20 times less time with the use of UAV. Additionally, UAV provides documentation trough orthomosaic.

Renewable energy sources based on wood are becoming increasingly important and popular. However, their increased consumption is inevitably connected with questioning their quality [1][2]. Quality is in specific cases determined by the method of production and the storage process [3][4]. The quality of wood chips is at present evaluated according to the calorific value and moisture content, which are often influenced, besides the wood species itself, by weather conditions and storage method [5][6][7][8][9]. The increased number of plants using wood chips as a source of energy is connected with raising the question of health and safety hazards associated with the production and storage of wood chips. The factors most hazardous for human health are represented by the hazards associated with the activity of fungi and moulds in Pol. J. Environ. Stud. Vol. 26, No. 6 (2017), 2633-2641 AbstractThe aim of our study was to monitor and analyze the main biological hazards connected to the long-term storage of wood chips for energy production. The analysis was carried out in four high-capacity storage yards of the town heating plants in the Banská Bystrica self-governing region in Slovakia. Five samples were taken from each pile of a rectangular shape and volume over 4,000 m 3 ; the sampling was carried out at the beginning of the monitoring period and at the end of the monitoring period (after one year). Thirtyfour species of microscopic fungi were identified (18 at the beginning of the monitoring period and 16 at the end of the monitoring period). Thirty-three of them can potentially cause severe diseases. Fungi of the genus Aspergillus, causing severe diseases, were identified as the most abundant. The research confirmed that if the length of storage time is more than a year, the potential hazards for human health increase due to the increasing number of spore-forming pathogens. Following the monitoring of atmospheric conditions the highest increase of harmful spores was recorded at the average annual temperature of 10ºC and precipitation of over 1,000 mm a year.