Activation of waste textiles prior to enzymatic or chemical conversion
Waste textiles are becoming an increasing environmental problem. Over the past six decades, the fiber consumption per capita has almost tripled, while the recycling rates for textiles are significantly lower than for other types of residues. For example, it has been estimated that only 12% of textiles are being recycled whereas paper, another cellulosic waste, registered recycling rates around 85%.
The problem with recycling (cellulose-based) waste textiles is that the fibers are often inaccessible to enzymatic or chemical conversion due to the high structural order of the material. Thus, the material needs to be activated so that it can be converted efficiently into the targeted product. At ShareTex, we have developed several technologies to achieve this in a cost-efficient manner: depolymerization with strong acids, treatment with green liquor and decrystallization with molten salts.
More information on our processes based on acid hydrolysis and treatment with green liquor can be found in the following links:
https://www.sciencedirect.com/science/article/pii/S0956053X20307194
https://pubs.rsc.org/en/Content/ArticleLanding/RA/2021/D1RA00168J#!divAbstract
Our most promising technology is based on decrystallization with molten salts as this treatment allows to reduce the crystallinity of the material while adjusting its degree of polymerization based on the targeted application. This means that the cellulose fibers contained in the residue can be adapted to produce regenerated textile fibers, but also other products such as platform chemicals or precursors to manufacture synthetic fibers.
Thanks to this versatility, our process can treat cellulose-based fabrics of varying quality, such as cotton and viscose, and offer different valorization alternatives (from textile-to-textile recycling to end-of-life valorization) for each of them based on their different characteristics.
