In the African context, where agricultural by-products and natural resources are often underutilized or considered waste or invasive species, this study aims to valorize locally available raw materials through the development of fully bio-based insulating composite materials. The materials were produced using typha, rice husk, residues from threshing millet ears, and cassava starch, through a simple and reproducible process accessible even at an artisanal scale. A total of 25 formulations were created by combining one to three of these raw materials with a natural binder. The resulting composites were characterized. The bulk density of the materials ranged from 198.64 to 361.02 kg/m3, while their thermal conductivity varied between 0.07 and 0.17 W/m·K. These results highlight the strong potential of these bio-based composites for use as thermal insulation in sustainable building applications.

It is essential to know the desorption isotherms to control the drying processes of agricultural products, food. The objective of this work is to determine the sorption isotherms of the local onion: the Violet de Galmi cultivated in the Niayes area. Desorption isotherms were studied for water activities ranging from 0.05 to 0.9 and for temperatures of 40 °C, 50 °C and 60 °C using the static gravimetric method. Six saturated salt solutions were used (KOH, K2CO3, NaBr, CuCl2, KCl and NaCl). The results show that the desorption isotherms of onion are type II and the equilibrium water content is temperature dependent. The experimental results are then smoothed by five models: Guggenheim - Anderson - De Boer (GAB), Brunauer - Emmett and Teller (BET), Henderson, Oswin and Peleg for the description of the equilibrium state of this product. From the modeling, it was concluded that both the Peleg model and the GAB model describe the desorption isotherms of onion well, but the Peleg model has the smallest relative errors, thus defining the Peleg model as the best model. From the results obtained, the isosteric heat of desorption is determined using the Clausius-Clapeyron equation.