Carbonization techniques and wood species influence quality attributes of charcoals produced from industrial sawmill residues in Eastern Cameroon

Abstract

Cameroon harvests a considerable volume of round wood each year, only a small part of which is used for manufactured products. In recent decades, various charcoal-making initiatives have emerged around industrial timber-processing units, particularly in the eastern region, in order to develop a market for residual biomass. However, the undifferentiated use of these residues obtained from different species often results in products with varying energy potential that are not always appreciated by consumers. Moreover, the physical and chemical characteristics of the charcoal produced are unknown, as are the factors that influence its quality. The aim of this study was to assess the variability of the physical and chemical properties of charcoal produced from industrial sawmill residues in the eastern region of Cameroon using different carbonisation techniques. Three wood species, Ayous, Frake and Movingui, and three types of kilns (traditional, improved traditional and Casamance system) were used. For each species, three bundles of five pieces of wood each were prepared, with an initial moisture content ranging from 28% to 36%. The physical and chemical properties determined were moisture content, apparent density, volatile matter content, fixed carbon content, ash content and Higher Heating Value (HHV). Our results showed that the charcoal properties varied depending on the wood species and types of kilns used. Movingui, with the highest density (0.73 g/cm3), produced charcoal with the lowest moisture content (4.03%) and the highest apparent density (0.42 g/cm3). The lowest volatile matter content (20.32%), the lowest ash content (1.27%) and the highest fixed carbon content (74.95%) were also obtained with this species. All these values were obtained with Movingui charcoal produced with the Casamance system. However, the highest HHV (32.51 MJ/kg) was obtained with charcoal from Ayous, also produced with the Casamance system. On comparing the three charcoaling systems used, the Casamance model yielded the best physical and chemical charcoal properties. All the charcoals studied complied with FAO standards for cooking fuel. The highest HHV obtained with charcoal from Ayous hardwood shows its ability to release large amounts of thermal energy during combustion.
 
 Keywords: Charcoal, carbonization technologies, eastern Cameroon, physicochemical properties, industrial sawmills wastes.

Quantification and Determinants of Carbonization Yield in the Rural Zone of Lubumbashi, DR Congo: Implications for Sustainable Charcoal Production

“…Thus, to enhance the efficiency of carbonization, it is essential to implement targeted strategies that address key factors influencing the wood-to-charcoal conversion process [72], including tailoring the carbonization parameters by tree species, which promotes a more efficient use of wood resources by aligning the species characteristics with market demands and optimizing the charcoal yield and quality; improving the charcoal quality by prioritizing large wood pieces based on diameter; selecting kilns that promote uniform heating and efficient air circulation, which is essential for consistent carbonization results; regularly maintaining and monitoring kiln performance, allowing the prompt identification and resolution of operational issues; and providing training, supported by collaboration with local extension services and research institutions, which would facilitate knowledge transfer and the effective implementation of recommended strategies [27,73].…”

Physical and mechanical properties of two tropical wood (Detarium macrocarpum and Piptadeniastrum africanum) and their potential as substitutes to traditionally used wood in Cameroon

“…7 Sawn timber dominates this industrial production in Central Africa, representing 80% of industrial production by volume in 2015 7 and a transformation rate of around 70% since 2021. 2 However, the timber sector in Cameroon and Central Africa makes a significant contribution to national economies 8 but remains under-industrialised, 9 as it is limited to primary processing products. 8 Its contribution to gross domestic product and job creation 10 is not negligible; it has often increased from 3.5% in 1989 11 to 6.7% in 1995 and 12% in 2000.…”

“…However, the timber sector in Cameroon and Central Africa makes a significant contribution to national economies 8 but remains under-industrialised, 9 as it is limited to primary processing products. 8 Its contribution to gross domestic product and job creation 10 is not negligible; it has often increased from 3.5% in 1989 11 to 6.7% in 1995 and 12% in 2000.…”