Towards sustainable textile waste management: Exploring valuable chemicals production through steam cracking in a dual fluidized bed

Artikel i vetenskaplig tidskrift, 2025

Global demand for textiles is rising due to population and economic growth, yet most end-of-life textiles are incinerated or landfilled, posing environmental risks. In Europe, less than 1 % of discarded textiles are recycled into materials of similar quality. Thermochemical recycling, such as steam cracking, offers a potential solution by breaking down polymer chains at high temperatures to produce valuable chemicals and reduce dependence on fossil fuels. This study explores the potential of producing valuable chemicals from steam cracking of textile waste in a semi-industrial dual fluidized bed (DFB) reactor powered by biomass. Experiments were conducted at temperatures ranging from 735° to 815 °C using polyester- and cotton-based materials rejected from textile sorting processes. Results showed effective conversion of heterogeneous feedstocks into syngas, light monomers (ethylene and propylene), and aromatic compounds like BTXS (benzene, toluene, xylenes, styrene) without need of extensive pre-sorting. Polyester-based textiles yielded an average carbon conversion of ∼11 % for syngas, ∼7% for light monomers, and ∼17 % for BTXS. From a carbon conversion analysis, the yields varied with temperature and feedstock composition: higher temperatures favored carbon oxides, while BTXS and light monomers remained stable. PET-rich batches produced more CO2 and aromatics, whereas cellulose-based feedstocks favored syngas production. Overall, steam cracking can achieve a carbon recovery rate of nearly 70 %, through valuable chemicals, syngas, and CO2 utilization, significantly outperforming the ∼3 % closed-loop recycling rate in current European schemes. These findings highlight the potential of steam cracking in DFB reactors as an alternative recycling method to enhance circularity in the textile industry.