Energy characterization of fresh and torrified pellets produced from Pinus waste wood

Abstract

he objective of this research was to evaluate torrified and fresh pellets produced from Pinus waste wood, used for direct generation of thermal energy. The compaction of Pinus sp. waste wood from lumbermill was performed in a pelletizer with a planar array of 8 mm. Roastings were performed in an electric furnace, type muffle, stabilized at final temperatures of 220 °C and 250 °C for 30 min. The following pellets properties were determined: apparent and unit energy density, bulk density, energy bulk density, immediate chemical composition (volatile materials, ash and fixed carbon), high heating value and moisture. It was observed an increase in high heating value and reduction of moisture content of torrified pellets. However, the gain in calorific value was less than the mass loss of the pellets after roasting, reducing the energy densities of the pellets. The pellets raw have marketing potential in European countries such as Germany, Austria and Sweden. The methodology used for roasting is not suitable for pellets heat treatment. However, further research on pellet roasting in a wider temperature and residence time range is recommended, in order to define parameters that optimize their energetic properties.