Termogravimetria aplicada para caracterização da biomassa
Resumen
Issues related to renewable energy have been increasingly addressed and discussed. In this
context, biomass is an alternative for the generation of renewable and available energy. Its
use, instead of fossil fuels, helps to reduce the environmental impact and the greenhouse
effect. The aim of this study was to verify the influence of biomass components on their
thermal degradation using thermogravimetry and to compare values for proximate analysis
and for a heating schedule. The materials used were pine (Pinus elliottii) and eucalyptus
(Eucalyptus Grandis x Eucalyptus Urophylla) woods and sugarcane bagasse (Saccharum
officinarum). The raw materials were analyzed in 4 different treatments: in natura, material
without extractives, holocellulose and lignin. The thermogravimetric analyzes were performed
on the Perkin Elmer TGA device Pyris 1 TGA. The analyzes were carried out under a
nitrogen atmosphere with a flow of 20 ml.min-1. The heating rate was 20 ° C.min-1 starting at
50 ° C to 900 ° C. Proximate analysis of the biomasses, the chemical composition of the
materials and the high heating value (HHV) with and without extractives were calculated. It
was observed that the presence of the extractives decreases the temperature of the beginning
of the thermal degradation, and they are the first ones to be volatilized, besides diminishing
the HHV. From the separated components of the biomass, it was observed that the polyses
and cellulose, which composes holocellulose, begin their degradation before lignin, which
presented a higher degradation temperature and a higher thermal stability.