Analysis of logging forest residues as an energy source

Abstract

Forest residue extraction levels in Greece are currently very low, but logging residues have the potential to be an important component of the wood energy supply chain. Forests are a major supplier of renewable energy. Exploring the possibilities of utilizing the biomass of logging residues for energy requires analysis and knowledge of its properties. In this research work the properties (ash, volatiles, fixed carbon, carbon, hydrogen, oxygen, nitrogen and calorific value) of the various constituents of the biomass of fir (Abies borisii - regis), pine (Pinus nigra), oak (Quercus frainetto) and beech (Fagus silvatica) logging residues were determined. Bark and ash content increased with decreasing diameter of branches. Ash content was higher in bark than in wood of branches in all species. Ash and nitrogen content was several times higher in bark and in foliage or needles than in wood of branches. Oak branches and twigs of all species had ash and nitrogen content higher than that required by the EN ISO 17225-2 standard for domestic pellets and they should not be used for energy, at least for pellets production. Volatile mater, fixed carbon, carbon and hydrogen content were in the range given by other researchers. Heating value is higher in softwood (fir and pine) than in hardwood (oak and beech) and ranged from 18.72 MJ/kg to 21.00 MJ/kg. In addition, Duncan's multiple range test was used to compare the means between the various constituents in all species.

Ultra-light-weight microwave X-band EMI shielding or RAM material made from sustainable pyrolysed cork templates

“…36 The nitrogen content of oak wood (cork is a type of oak) varies between around 0.2-1.1%, depending on the species and the part of the tree analysed. 37 Therefore, we would expect there to be a remaining small N content in any carbon from pyrolysed wood, and this percentage will be greater in the pyrolysed carbon than in the original wood, as O and H is lost in the process. We have shown that our cork pyrolysed in N 2 contained 1.57 wt% nitrogen, 38 which is of the levels to be expected from the original wood content, and probably does not indicate any extra N doping from the pyrolysis atmosphere.…”