Influence of Bark on the Physical and Thermal Decomposition Properties of Short-Rotation Eucalyptus

Abstract

Highly productive short-rotation woody crops is one group of biomass feedstocks that has been identified as having the potential of meeting the goal of reducing the world’s reliance on crude oil. The goal of this project is to quantify the influence of bark on the physical properties, moisture sorption properties, and thermal decomposition of short-rotation (3 years old) Eucalyptus—the most widely planted short-rotation hardwood grown in the world. Results obtained from the study show that the physical properties of ground samples were significantly different between “no-bark” and “with-bark” samples with the bulk density of the with-bark samples decreasing by up to 20 % with a corresponding increase in compressibility of up to 75 %. The moisture sorption rate and the equilibrium moisture relations of the two samples were also significantly different. The susceptibility of no-bark sample to microbial degradation was higher. Thermal decomposition rate and peak temperatures for cellulose and hemicellulose were not affected by the presence of bark. The information obtained from this study will be important in the design and selection of systems for handling, storage, transporting, and thermochemical conversion of short-rotation Eucalyptus.