RECYCLEX

Textile waste accounts for nearly 7.5 million tons per year in Europe, of which 30 – 35 % are collected and less than 1 % is recycled into new products. The main technological challenges hindering mechanical or chemical recycling of textile are associated with the presence of elastane (polyurethane, PUR) fibers. Moreover, the presence of dyes limits application possibilities and thus also economic value.

Our proposal aims to tackle these challenges by providing innovations at several levels (see figure 1)

1. Develop a novel optical detection approach for elastane compatible with industrial sorting that allows to efficiently differentiate textiles based on their elastane content. This will be based on a recently patented optical detection and sorting platform developed by KULeuven (Ameloot group). 

2. Develop a novel and highly efficient process to selectively remove elastane by depolymerization, allowing to obtain elastane-free textiles suitable for processing by the current textile recycling methods. This development will be based on the new class of splitting agents recently patented by KU Leuven (De Vos group). Key innovations are that it will (1) enable to selectively depolymerize elastane from polyester despite their chemical similarities, (2) allow low chemicals use as compared to state-of-the-art extraction, and (3) be combinable with decolorization. 

3. Turn the reaction into an industrially relevant process by process intensification. This will include the transformation of the reaction into a continuous process based on an approach already applied in biomass processing (VITO-SPOT). Moreover, to allow the reuse of the novel elastane splitting agent and valorization of the elastane derived reaction products, their splitting is needed after reaction. For this, tailored shaped solid catalysts (VITO-CAST) will be developed, that will be combined with novel selective sorbents to allow simultaneous dye removal. 

Recyclex will cover all aspects of the textile chain, including a valorization assessment of the product streams (CENTEXBEL & VITO), and thus make a comprehensive contribution to the recycling sector of Flanders. The newspaper “De Standaard” recently called it even a golden opportunity for Flanders due to (i) the enormous potential for textile recycling and (ii) its history and expertise in fabric making. Recyclex will remove the roadblocks for the two major textile waste streams (polyester and cotton). This innovation is urgently needed considering that the EU waste directive has established strict guidelines to elevate textile recycling figures. In 2025(!) already, the separate collection of textiles will become mandatory. By 2030, recycled fiber content will become compulsory with strictly regulated exports.

Figure 1: (top) Elastane occurs in textiles as interwoven and core-spun fibers. After applying our novel detection approach, the elastane fibers are clearly distinguishable from the surrounding cotton fibers. (bottom) General approach of Recyclex with the different objectives