The wood heat treatment results in the partial degradation of its chemical constituents, mainly cellulose and hemicellulose, reducing the hygroscopicity of the material. This process improves the dimensional stability and resistance to biodeterioration and worsens the mechanical resistance. This work aimed to evaluate the effect of heat treatment on the physical, anatomical, chemical, and mechanical properties of Fraxinus excelsior wood. In untreated and heat-treated wood, the pH, buffering capacity, basic density, equilibrium moisture content, shrinkage, wood anatomy, thermogravimetric behavior, and chemistry by conventional and FTIR methods were determined.

This study explores a circular economy approach in charcoal production, utilizing combustion gases from the process itself to optimize efficiency and quality, minimizing waste and reducing emissions. The research investigates the pre-drying of Eucalyptus sp. wood with these gases before carbonization, through an innovative system that directs gases from the carbonizing furnace to a separate drying furnace. Wood samples were dried at 120 °C and 150 °C for 15, 22.5, and 30 h before carbonization. The analysis included the gravimetric yield of charcoal, semi-carbonized wood, and fines, in addition to evaluating key charcoal properties. Results demonstrated that drying with combustion gases at 150 °C increased the charcoal yield by 7%, regardless of drying time. Furthermore, this pre-drying improved charcoal quality, raising fixed carbon content from 74.68% to over 81% and reducing volatile matter from 24.40% to below 18%. These findings highlight that the utilization of combustion gases for wood drying not only significantly enhances the efficiency and quality of charcoal production but also contributes to the reduction in greenhouse gas emissions, promoting a more sustainable and environmentally friendly alternative compared to conventional methods.

High and variable moisture in wood logs limits their use in continuous carbonization reactors. Artificial drying emerges as a solution to homogenize the moisture of the raw material, optimizing the process, increasing yield, and improving the quality of charcoal. This study aimed to develop an experimental fixed-bed drying system for logs, evaluating the effects of cutting layout (40 cm, 20 cm, and split), diameter class (>12 cm, 12.1–14 cm, 14.1–16 cm, and 16.1–18 cm), and residence time (30, 60, and 90 min) at 300 °C. Split logs showed higher heating and drying rates, positively impacting efficiency. However, split and 20 cm logs subjected to 90 min of drying underwent combustion, indicating operational limits for these layouts under the tested conditions. The heartwood and sapwood regions of split logs heated more rapidly, resulting in higher drying rates and moisture loss, directly affecting drying efficiency. Split logs dried for 60 min showed the best drying efficiency and greatest moisture reduction, making this the most recommended treatment. This study not only demonstrates the technical feasibility of artificial drying of logs for continuous carbonization but also establishes fundamental guidelines for the development of more efficient, safe and sustainable industrial technologies in the charcoal production sector.

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.

Forest operations consume a large amount of fossil fuels. Storing wood in the field reduces the weight of the wood, optimizing transportation and reducing fuel consumption. However, there are few studies linking these variables. The objective was to evaluate the drying of logs with different diameters and assess the fossil fuel consumption considering the mass of dry wood transported. Eucalyptus logs were divided into two diameter classes: 6 ≤ D1 ≤ 11 cm and 11.1 ≤ D2 ≤ 14 cm. These logs were arranged in a stack, divided into base, intermediate, and top positions, and subjected to drying. The wood moisture values were correlated with the amount of transported dry wood, fuel consumption, and costs. These calculations were based on a vehicle with a load capacity of 41.6 Mg, a fuel consumption rate of 1.82 L/km, and a road cost of 0.51 R$·Mg⁻¹·km⁻¹. The moisture content was lower in smaller-diameter logs located at the top of the storage stack and higher in larger-diameter logs in the intermediate position and in both diameter classes at the bottom position after 365 days of drying. Storage for 365 days, on average, increased the dry wood transport capacity by 90%, resulting in similar gains in fuel economy and the final cost of transportation. Storing wood outdoors has proven effective in reducing its moisture content, resulting in lower fossil fuel consumption during forestry operations, reducing environmental impact, and generating economic gains.