Sawdust from a termite-resistant African tree yields antioxidants and clean-burning fuel briquettes

Researchers have turned sawdust from Dabéma (Piptadeniastrum africanum), a hardwood prized for its natural durability, into two useful streams at once: extracts rich in bioactive compounds and solid fuel briquettes. The study, published in Discover Applied Sciences, frames the work as a circular-economy approach in which a major by-product of the forestry industry is valorized into high value-added products and sustainable energy alternatives rather than discarded as waste.

The team combined biorefinery and energy techniques on the same sawdust, first isolating secondary metabolites and then pressing the processed material into briquettes. Extraction method mattered for the chemistry of the extracts. Total polyphenol content ranged from 0.005 ± 0.001 to 0.148 ± 0.019 grams of gallic acid equivalents per 100 grams of dry matter, with the higher value obtained by infusion and the lower by maceration. Total flavonoids ranged from 0.004 ± 0.001 to 0.009 ± 0.001 grams of catechin equivalents per 100 grams of dry matter, again favoring infusion over maceration. Tannin content, by contrast, was essentially the same under both methods, at 0.006 ± 0.002 grams of tannic acid equivalents per 100 grams of dry matter for maceration and 0.006 ± 0.001 for infusion.

The key question was whether removing those metabolites would compromise the fuel. Statistically, it did not affect the immediate and combustion properties of the briquettes, with p-values above 0.5. However, extraction did influence the energetic and mechanical properties, with p-values below 0.5. The Higher Heating Value ranged from 25,373 ± 263 kilojoules per kilogram for briquettes that had undergone metabolite extraction to 26,424 ± 25.5 kilojoules per kilogram for those without, so the unextracted material held a modest calorific edge. Mechanical durability shifted in the same direction: the Shatter Resistance Index spanned 327.4 ± 25 percent for fuels without secondary metabolites and 244.1 ± 29.2 percent for fuels with them.

Analytical chemistry helped explain what heat was doing to the biomass. Energy-dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy confirmed that thermal treatment increases the carbon content of the material while reducing its oxygen content, a change consistent with the concentration of energy-dense carbonaceous material in the fuel.

The bioactive side of the biorefinery points toward a second application. Dabéma wood is classified as durability class D, meaning it is highly resistant to termites, and the authors state that future research will focus on exploring whether its extracts can serve as potential agents to enhance the resistance of wood species and derived materials that are vulnerable to termite attack. If that line of work succeeds, the same sawdust could supply both a renewable solid fuel and a natural protective treatment, closing the loop on a waste stream that sawmills currently generate in volume.

The findings remain at the laboratory stage, and the reported values are measured ranges with stated uncertainties rather than performance guarantees for industrial-scale production. The article was shared as an accepted, peer-reviewed version carrying a permanent DOI, subject to further editorial edits before the final Version of Record. Even so, the study offers a concrete template for multifunctional valorization: one forestry by-product, two product streams, and quantitative evidence that extracting value from the chemistry of the wood need not come at the cost of its value as fuel.

Subject of Research: Biorefinery valorization of Dabéma sawdust into bioactive extracts and solid fuel briquettes

Article Title: Circular economy and multifunctional valorization of Dabéma (Piptadeniastrum africanum) sawdust for biorefinery applications and clean sustainable energy

Article References: Appiah, K. E. K., Nganko, J. M., Toure, A. O., Koffi, P. M. E., Biwôlé, J. J. E., Djeukui, V. N., Lamah, L., Moumouni, N. P., Ntanga, P., KOBENAN, K. N. S., Niome, B., Gbaha, P., & Yao, K. B. (2026). Circular economy and multifunctional valorization of Dabéma (Piptadeniastrum africanum) sawdust for biorefinery applications and clean sustainable energy. Discover Applied Sciences. https://doi.org/10.1007/s42452-026-09720-9

Image Credits: AI Generated

DOI: 10.1007/s42452-026-09720-9

Keywords: circular economy, biorefinery, sawdust, Dabéma, Piptadeniastrum africanum, biofuels, briquettes, polyphenols, flavonoids, tannins, higher heating value, termite resistance