Thermogravimetric and devolatilisation analysis for five plantation species: Effect of extractives, ash compositions, chemical compositions and energy parameters

Woody biomasses from five fast-growth plantations of Costa Rica were evaluated in relation to thermal degradation characteristics and devolatilisation rate (Drate) using thermogravimetric analysis (TGA). The relationship between TGA parameters and Drate with content of cellulose, lignin and extractives were established. The results indicate that during degradation, the five woody biomass types (Cupressus lusitanica, Dipterix panamensis, Gmelina arborea, Tectona grandis and Vochysia ferruginea) show different temperatures and residual mass, as well as different Drate of the polymers conforming them, indicating that each biomass type has unique pyrolysis characteristics. The difference in these parameters is influenced by extractives content, and a little effect is presented due to lignin content, cellulose content and ash composition. A greater amount of extractives decreases the degradation temperatures of the different biomass components, although the residual mass was scarcely affected and if so, a positive correlation was presented. Extractives also affected the Drate more significantly than cellulose, lignin and macro- or micro-nutrients contents. Moreover, the Drate of cellulose was more affected by the extractives content than was Drate of hemicellulose, indicating a higher degree of association of extractives with cellulose than hemicellulose. In this concern, the higher the amount of extractives, the lower the Drate of cellulose.