Valorization of peanut husk biomass into a sodium lignosulfonate and cellulose aerogel for sustainable building materials

Agricultural waste, such as peanut husks, is often underutilized despite its potential as a sustainable resource for value-added materials. Converting such waste into functional products can reduce environmental burden while providing cost-effective alternatives for construction applications. This study explores the valorization of peanut husks by separating lignin and cellulose components to produce sodium lignosulfonate (SLS) and cellulose aerogel. Lignin extraction was performed using an alkaline solution, followed by sulfonation to produce SLS. Separated cellulose was processed into aerogel through freeze-drying with sodium alginate and CaCl 2 for gel formation. The synthesized SLS demonstrated effective water-reducing capabilities, improving cement paste fluidity by 124.1 % at 0.75 % content, though still below the performance of commercial SLS. Nonetheless, the promising characteristics of this bio-base product present a cost-effective alternative that reduces dependence on imported additives. Additionally, cellulose aerogel exhibited outstanding thermal insulation properties with a density of 0.13 g·cm -3 and a thermal conductivity of 0.029 W·m -1 ·K -1 , surpassing several traditional insulation materials. The combined application of peanut husk-derived SLS and cellulose aerogel demonstrates a promising pathway for developing eco-friendly construction materials with both economic and environmental benefits. These findings highlight the potential of peanut husk valorization to promote sustainable construction practices while supporting circular economy principles. By transforming agricultural waste into bio-base functional materials, this study not only enhances the performance of cement mixtures and building insulation but also addresses environmental concerns by minimizing waste.