Clean process for dissolving wood cellulose for the production of textile yarn – RegenCell

Regencell aims at developing a new textile production process from wood or annual plants cellulose dissolving pulp, as an environmentally friendly and cost-efficient alternative to the existing viscose polluting process. Relying on promising exploratory results, 3 university laboratories and a technical centre propose an innovative, sustainable and scalable process to dissolve cellulose in sodium hydroxide at room temperature and regenerate it mainly in the form of threads and films. It combines 1) the selective oxidation of cellulose to generate groups that promote its dissolution in an alkaline medium. This step aims to create suitably localized carboxyl groups, in an amount sufficient to ensure the complete dissolution of the cellulose in an aqueous sodium hydroxide solution, but low enough not to compromise its regeneration at lower pH; 2) intensification of the process by physicochemical and mechanical means. These include the use of a high-consistency mixer well suited to the treatment of fibrous substrates and a paper-type refiner promoting fibrillation of these substrates; 3) recycling of the oxidation reagents by innovative and clean chemical means; and 4) the formation of yarns (and other cellulose products) from the cellulose solution by controlled reduction of the alkalinity of the medium as it leaves the spinneret. This process is expected to produce yarns with mechanical qualities at least equal to those of conventional viscose yarns, but which may also have specific properties of interest for certain uses, for example for hygiene or medical products. The entire technological chain is designed to be integrated into a cellulose production plant, thus making it possible to pool the use of reagents and the management of effluents. The process will be validated at lab scale thanks to LCA. A piece of cellulose textile will be produced as proof of concept. Economic impacts are expected with the possible relocation in Europe of the rayon production.