DETAILED CHARACTERIZATION OF SOLID AND VOLATILES PRODUCTS FROM BIOMASS TORREFACTION

摘要

Torrefaction of beech and spruce chips has been conducted in a fixed bed reactor at different temperatures in the range from 200 to 330°C. The torrefied products and released volatiles have been characterized in an extensive way. The temperature range of the devolatilization of the hemicellulose and cellulose fractions has been determined, as well as the increase in elemental and fixed carbon in torrefied biomass with higher temperature. Cl, S and N are released in a significant proportion, which increases with temperature. The main components in the torrgas are, in order of importance, H_2O, CO_2, gravimetric tars, acetic acid and CO. Temperature has a limited influence on the composition of the torrgas. Beech produces more acetic acid than spruce, while the proportions of the other components are similar for both wood species. Gravimetric tars account for more than 10% of the mass of the torrgas.