Synthesis of Cellulose Aerogel Fibers from Agricultural Residues and Considerations on its Continuous Production

Abstract

Academia and industry have been developing ways to produce novel materials from renewable bio-based sources. We have been developing strategies to produce cellulose aerogel fibers from waste hemp fibers and study its continuous production using the LabLineCompact® technology. Alkali hydrolysis and bleaching established a simple method to extract high-grade cellulose from hemp waste fiber fibers. Cellulose solution was prepared by dissolution using a mixture of NaOH, urea, and water as solvent. Optimal parameters such as cellulose concentration and operational conditions of the LabLineCompact® were analyzed, and the production of highly porous aerogel fibers was accomplished from commercial and extracted cellulose. After selection of the best parameters, up-scaling experiments were performed using a Fourné "Lab-to-Pilot" wet-spinning machine. Besides the valorization of waste biomass resources and the production of highly porous aerogel fibers, we developed a continuous system for producing, washing, and exchanging the solvent of the fibers before drying.