Organosolv fractionation and pulp upgrading of wheat straw for production of continuous cellulosic fibers by wet‐spinning

Textile production is an important industrial sector but also one of the most polluting industries and highly dependent on fossil resources and cotton for the production of fibers. The use of cellulosic fibers from local agricultural residues can offer a sustainable alternative for the current textile industry. In this work, an environmentally friendly, ionic liquid‐based fiber spinning process is applied. Cellulose was produced via a biorefinery concept comprising pre‐extraction, mild acetone organosolv fractionation and pulp upgrading by alkaline treatment. Pre‐extraction of the wheat straw increased the cellulose content of the pulp obtained from organosolv fractionation and improved downstream processing. The Si‐rich ash components were successfully removed by alkaline treatment of the organosolv pulp under optimized conditions. Based on the final cellulose and ash content, upgraded wheat straw pulp was found to be suitable for wet spinning into filament fibers in an ionic liquid‐based process. The obtained fibers had comparable properties (fineness, elongation and crystallinity) as reference filaments; however, further optimization of the spinning process of this new material would be required to improve tenacity as well as produce textile‐grade fibers.