Post-consumer textile thermochemical recycling to fuels and biocarbon: A critical review

Abstract

This study aims to look at waste-to-energy (tertiary recycling) of post-consumer textile waste, based on a literature review. Because textiles are mostly made of cotton and polyester, which are carbon and energy sources, they can potentially be converted thermochemically into fuels and biocarbon. The critical parameters determining thermal recycling are summarized and discussed with a focus on pyrolysis, gasification, and torrefaction. For cotton and polyester mixtures, torrefaction presents a low environmental impact and an energy-dense fuel that can be used in cogeneration systems, reducing the energy requirements of these processes by 50-85%. Catalytic pyrolysis of cotton textile waste yields to a high conversion (90 wt%), a liquid fuel of high yields (35-65 wt%), and biocarbon (10-18 wt%), providing carbon and energy closure loops. However, pyrolysis is energy-intensive (T > 500 °C) and produces hazardous chemicals from the conversion of PET, nylon, and polyacrylonitrile. Gasification can handle many types of textile waste, but it needs continuous monitoring of the emissions. More research is needed to overcome existing limitations, LCA and sustainability assessment are required for the thermal recycling processes in order to estimate their future-proofing and sustainability. For the transition to a circular economy, consumers' awareness of resources limits and sustainable use is pivotal to change purchasing behavior and achieve a recycling thinking.

Keywords: Circular economy; Gasification; Post-consumer waste; Pyrolysis; Textile; Torrefaction.