Study of devolatization rates of pine wood and mass loss of wood pellets

The present work investigates the mass loss of fine wood biomass using a TA INSTRUMENTS SDT 2960 simultaneous DSC-TGA instrument. The samples of sawdust were classified according to the grain size (< 0.063, 0.063-0.125, 0.125-0.25, 0.25-0.5, 0.5-1, and > 1 mm) and the micro samples were tested with air at a constant heating rate of 10 K/min, from the room temperature up to 800ºC. From the results the kinetic properties of the biomass fuel were determined using the 1st order Coats- Redfern equation. A transient thermal model of the fuel was implemented and was coupled with the biomass kinetic data in order to compute the mass loss of individual pellets and the results were compared with experimental data. The remaining mass, as fix carbon and ashes or unburnt substances, is approximately 3%. The kinetic parameters indicate that the biomass reactivity depends upon the particle size. The heating treatment of wood pellets at constant temperature and different time produced less nitrogen and more carbon and hydrogen for the short period of time.This work is supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI01-0145-FEDER-006941. This work was financed by FCT, under the Strategic Project UID/SEM/04077/2013; PEst20152020 with the reference UID/CEC/00319/2013