Timber wastes torrefaction for energy use

Abstract

The experiment consists in the realization of timber wastes torrefaction at a final temperature of 280 ºC, with heating rates of 0,5 ºC.min -1 , with 1 hour permanence in the final temperature. Three different types of wastes were analyzed by composition. Moisture content, bulk density, torrefied mass yield, gross calorific value, particle size, and physical and mechanical resistance were determined. Except the moisture content, the remaining variables were evaluated before and after torrefaction. The results indicated that torrefaction increased the wastes energy density . The torrefied material yield was influenced by the particle size. Bulk density was reduced; however, the mass reduction was higher than the volume reduction. The calorific value was increased for all types of torrefied wastes. Torrefied wastes friability was higher compared to in natura wastes.

Effect of torrefaction temperature on properties of Patula pine

“…Materials with higher heating value and low moisture content can benefit thermochemical processes such as combustion and gasification as the reaction temperatures in those processes can be increased (Pérez et al 2012, Torres-Fuchslocher andVaras-Concha 2015). Other authors have reported results on the changes in biomass composition (at different torrefaction conditions) that are consistent with the findings of this study (Bridgeman et al 2010, da Silva Grassmann et al 2016. Figure 2 shows the TG and DTG curves of the raw and torrefied PPat to evaluate the effect of torrefaction process.…”

“…Torrefaction is a mild thermochemical process conducted in oxygen-free environments at temperatures ranging from 200 to 300 °C (Bridgeman et al 2010, Chen and Kuo 2010, Ibrahim et al 2013, Phanphanich and Mani 2011, Xue et al 2014. In this range of temperatures, in addition to moisture and volatiles release, degradation of hemicelluloses occurs, while cellulose is subjected to dehydration and both cellulose and lignin are subjected to partial depolymerization (da Silva Grassmann et al 2016, Pelaez-Samaniego et al 2013.…”

“…The process of torrefaction alters the physical properties of biomass, reducing its bulk density and its fibrous tenacious nature (da Silva Grassmann et al 2016). This could allow increased rates of comilling and co-firing in coal fired power stations, which in turn would enable reduction of the amount of coal used and an increase in the use of renewable fuels, without the need for additional infrastructure.…”