Physico-Chemical Characteristics and Study Valorization Ways of the Cotton Sector Waste in Benin to Biobased Building Materials

Abstract

The economic importance of the cotton sector in West African countries has led to the development of this sector, which now generates a large quantity of waste. The objective of the present study is to investigate the possibilities of valorization of the by-products of the cotton sector into construction materials. The investigations near the actors of the cotton sector have made it possible to trace the itinerary of the cotton and to bring out fifteen (15) by-products from industries of which five (5) in the ginning mills, six (6) in the crushing mills and four (4) in the textile mills. The most important ones are cotton seed hulls, ginning clods and glue wastes which represent respectively 16%, 1.45% and 0.84% of the annual cotton production. Some physico-chemical characteristics allowed to evaluate the use of these by-products in construction materials. The higher calorific value and the protein content, which are respectively 19,536 J/g and 1.6%, make the hulls an alternative fuel and a feed for livestock. This by-product is fully utilized. As for the ginning clods, they are in the form of fibers. Due to their low apparent density of 25 kg/m3, it is possible to use these clods in the manufacture of light construction materials. The glue wastes also contain 18% of starch, which makes it possible to consider its use in the production of thermal insulation panels inside the building. Although this study allows us to identify possible ways to valorize the by-products of the cotton sector, it remains to find the appropriate methods of their implementation.