Carbonization gases as an energy source for Eucalyptus logs drying of different diameter classes in metallic dryer

The wood carbonization with high moisture content reduces the yield, prolongs the carbonization time and results in charcoal with low mechanical strength. Considering this, the reuse of carbonization gases as a source of thermal energy becomes a potential alternative for reducing moisture content quickly and feasibly. The objective of this study was to evaluate the artificial drying of logs using gases from the carbonization system of a furnace and a drying chamber. The drying evaluation was conducted in duplicate using a 35 m³ galvanized metal square dryer and a furnace with a useful volume capacity of 16.8 m³. The average gas intake temperature for drying was 150°C. The eucalyptus logs were divided into three diameter classes (8-14 cm; 14-22 cm; 8-22 cm). The electricity consumption of the dryer was approximately 49.4 kW per ton of wood (dry mass). The highest thermal efficiency was achieved in the drying of 8-14 cm diameter class logs. The utilization of carbonization gases proved to be effective in reducing wood moisture in all diameter classes, showing potential for large scale utilization.