Circular economy and the environmental sustainability of cellulosic materials in the clothing industry

Abstract

As one the world's largest and most polluting industries, clothing and textiles has become the focus of research, investment, and policy towards a circular economy (CE). A CE aims to mitigate environmental damage by regenerating, narrowing, slowing, and closing the flow of materials in the economy. Cellulose is a naturally occurring, biodegradable polymer that, until recently, has been the most prominent material used to produce clothing. While it remains well-suited to clothing applications, linear industry practices have become unable to meet market demand and attribute high environmental cost to cellulosic materials. This systematic literature review evaluates CE strategies for cellulose in the clothing sector and the data and methods used to assess the environmental impacts in life cycle assessment (LCA). Literature on material recycling dominates the findings and is categorised by the material's functional equivalence (closed-loop) or difference (open-loop) to the previous life cycle. Closed-loop recycling is prioritised for preserving material value, with the potential displacement of virgin materials offering significant environmental benefits. The review examines closed-loop recycling in detail, identifying cellulose regeneration from post-consumer textiles with >90% cotton as a key opportunity for CE advancement, and maps the scientific and industry developments for the evaluation of life cycle impact knowledge. The analysis of the LCA literature finds gaps related to the inventory data description, specificity (in hotspots and novel processes), and coverage of key technologies and regions of industry development. The shortfalls in scenario coverage, along with disparity among the Life Cycle Impact Assessment (LCIA) methods, highlight a need for the environmental superiority or equivalence of the recycled materials to be determined. Future assessments should involve more complete and up-to-date LCIA methods to address gaps, enhance relevance and further the rigour of results. The assumption that the recycled cellulose will substitute a virgin equivalent is frequently employed for the allocation of life cycle impacts and bears significant influence on the LCA results. Further research is needed to validate or disprove this assumption to address uncertainty in the allocation procedures and better understand the impacts of closed-loop recycling in the context of a circular clothing industry.

Date of Award	4 Dec 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Claudia Henninger (Main Supervisor) & Alejandro Gallego Schmid (Co Supervisor)