Study of mass loss and elemental analysis of pine wood pellets in a small-scale reactor

Abstract

Studying the thermal decomposition of wood pellets is an important subject in order to understand the behavior of wood pellets during the combustion process. In fact, wood pellets have become an important fuel used in boiler combustion. The objective of this study is to investigate the mass loss and elemental analysis of pine wood pellets at various times and temperatures. Commercial pellets with a diameter of 6 mm were used. The experiment was conducted in the laboratory of the Engineering University of Minho. The pellets were burned in a small reactor of 1.36 kW with a maximum temperature range of 1150 °C. The data were observed at different temperatures: 264, 351, 444, 541, 650, and 734 °C, and at time intervals of 30, 60, 120, 180, 240, 300, 600, 900, 1200, and 3600 s. The results of the experiment revealed that the reaction rate increases with the temperature, and the higher the combustion temperature applied, the higher the mass loss of all substances observed. The remaining mass, as fixed carbon and ash or unburned substances, is about 3%. The residence time and temperature influence the species concentration of wood pellets.