Drying biomass for energy use of Eucalyptus urophylla and Corymbia citriodora logs

Abstract

Brazil is the world’s largest producer of charcoal, mainly for the steel industry. Fresh wood has high moisture content, which reduces its use for energy. Thereby, drying is a fundamental step for charcoal production. This work aimed to determine longitudinal variation in stem diameter, wood basic density, moisture content, and calorific value of Eucalyptus urophylla and Corymbia citriodora logs. These logs were taken from different longitudinal positions on the trees and dried for 90 d; the net calorific value was determined based on the gross calorific value and moisture content. Curves and models were generated based on this data for moisture content and net calorific value during the 90-d period. The logs from the base and middle of C. citriodora trees had lower initial moisture content, and, after 90 d of drying, all logs from the top reached the equilibrium moisture. Drying the logs increased the wood calorific value, with an increase of 49.36%, 63.86%, and 85.98% for those of the base, middle, and top, respectively. The models generated had a high coefficient of determination and a low standard error.