Exergy Footprint Assessment of Cotton Textile Recycling to Polyethylene

Circular economy implementations tend to decrease the human pressure on the environment, but not all produce footprint reductions. That observation brings the need for tools for the evaluation of recycling processes. Based on the Exergy Footprint concept, the presented work formulates a procedure for its application to industrial chemical recycling processes. It illustrates its application in the example of cotton waste recycling. This includes the evaluation of the entire process chain of polyethylene synthesis by recycling cotton waste. The chemical recycling stages are identified and used to construct the entire flowsheet that eliminates the cotton waste and its footprints at the expense of additional exergy input. The exergy performance of the process is evaluated. The identified exergy assets and liabilities are 138 MJ/kg ethylene and 153 MJ/kg ethylene, reducing the Exergy Footprint by 75% and the greenhouse gas footprint by 43% compared to the linear pattern of polyethylene production. The exergy requirements for producing raw cotton constitute a large fraction of the liabilities, while the polyethylene degradation provides the main asset in the reduction of the Exergy Footprint.

A Systematic Literature Review for the Recycling and Reuse of Wasted Clothing

With the growing frequency and quantity of clothing purchases, the elimination rate of waste clothing is increasing. Many researchers have contributed to the topic of the recycling and reuse of waste clothing, and therefore many related literature reviews are emerging. The current reviews only focus on waste textile recycling and waste-clothing life-cycle evaluation. The topic of waste-clothing recycling itself is ignored. In this article, we propose a systematic review of the recycling and reuse of wasted clothes. Firstly, we summarize the existing methods of waste-clothing collection and recycling and the related recycling technology, and discuss their advantages and disadvantages. The involved literatures are journal articles, book chapters, and conference papers selected from Google Scholar and Web of Science. Citespace software, as a literature visualization tool is used for the analysis. Based on this review, the low efficiency of waste-clothes recycling can be attributed to poor organization from a management aspect. From a consumer perspective, because of the differences in understanding among consumers about waste-clothing recycling, the existing clothing-recycling system cannot be fully utilized. The results of this review provide reference for further research on waste-clothing recycling, and make suggestions for the relevant governmental/industrial development strategies.

Possibility Routes for Textile Recycling Technology

The fashion industry contributes to a significant environmental issue due to the increasing production and needs of the industry. The proactive efforts toward developing a more sustainable process via textile recycling has become the preferable solution. This urgent and important need to develop cheap and efficient recycling methods for textile waste has led to the research community’s development of various recycling methods. The textile waste recycling process can be categorized into chemical and mechanical recycling methods. This paper provides an overview of the state of the art regarding different types of textile recycling technologies along with their current challenges and limitations. The critical parameters determining recycling performance are summarized and discussed and focus on the current challenges in mechanical and chemical recycling (pyrolysis, enzymatic hydrolysis, hydrothermal, ammonolysis, and glycolysis). Textile waste has been demonstrated to be re-spun into yarn (re-woven or knitted) by spinning carded yarn and mixed shoddy through mechanical recycling. On the other hand, it is difficult to recycle some textiles by means of enzymatic hydrolysis; high product yield has been shown under mild temperatures. Furthermore, the emergence of existing technology such as the internet of things (IoT) being implemented to enable efficient textile waste sorting and identification is also discussed. Moreover, we provide an outlook as to upcoming technological developments that will contribute to facilitating the circular economy, allowing for a more sustainable textile recycling process.

A Delphi-Régnier Study Addressing the Challenges of Textile Recycling in Europe for the Fashion and Apparel Industry

The increasing resource pressure and the expanding amount of textile waste have been rising recycling as a clear priority for the fashion and apparel industry. However, textile recycling remains limited and is therefore a targeted issue in the forthcoming EU policies. As the fashion industry is embedded in complex value chains, enhancing textile recycling entails a comprehensive understanding of the existing challenges. Yet, the literature review suggests only limited empirical studies in the sector, and a dedicated state-of-the-art is still lacking. Filling this gap, a Delphi study was conducted supplemented by the Regnier’s Abacus technique. Through an iterative, anonymous, and controlled feedback process, the obstacles collected from the extant literature were collectively discussed with a representative panel of 28 experts, compared to the situation in Europe. After two rounds, the lack of eco-design practices, the absence of incentive policies, and the lack of available and accurate information on the product components emerged as the most consensual statements. Linking theory to practice, this paper aims to improve consistency in the understanding of the current state of textile recycling in Europe, while providing an encompassing outline of the current experts’ opinion on the priority challenges for the sector.

Textiles for Circular Fashion: The Logic behind Recycling Options

For the textile industry to become sustainable, knowledge of the origin and production of resources is an important theme. It is expected that recycled feedstock will form a significant part of future resources to be used. Textile recycling (especially post-consumer waste) is still in its infancy and will be a major challenge in the coming years. Three fundamental problems hamper a better understanding of the developments on textile recycling: the current classification of textile fibres (natural or manufactured) does not support textile recycling, there is no standard definition of textile recycling technologies, and there is a lack of clear communication about the technological progress (by industry and brands) and benefits of textile recycling from a consumer perspective. This may hamper the much-needed further development of textile recycling. This paper presents a new fibre classification based on chemical groups and bonds that form the backbone of the polymers of which the fibres are made and that impart characteristic properties to the fibres. In addition, a new classification of textile recycling was designed based on the polymer structure of the fibres. These methods make it possible to unravel the logic and preferred recycling routes for different fibres, thereby facilitating communication on recycling. We concluded that there are good recycling options for mono-material streams within the cellulose, polyamide and polyester groups. For blended textiles, the perspective is promising for fibre blends within a single polymer group, while combinations of different polymers may pose problems in recycling.

Enzymatic textile recycling – best practices and outlook

Recently, textiles and their end-of-life management have become the focus of public and political attention. In the European Union the revised waste framework directive defines textiles as municipal waste and stipulates their separate collection by 2025. In the context of these developments, this paper summarises briefly the current state-of-the-art in textile recycling. It is evident that recycling methods are not yet fully developed. This is especially the case with multi-material textiles, which are composed of two or more polymers that are incompatible for recycling. In the practical part of the communication, results are presented which show that enzymatic hydrolysis is a suitable process for recycling textiles made of cotton and polyester. After a complete removal of cotton, the remaining pure polyester fibres undergo a re-granulation and post-condensation step. The so obtained recycled polyester is fed back into the textile processing chain and finally towels are obtained. The main steering parameters of the enzymatic hydrolysis process are described. The study proves that solutions in accordance with the Circular Economy in the textile sector are available but an industrial implementation has not yet been realised.

Textile Waste Fibre Regeneration via a Green Chemistry Approach: A Molecular Strategy for Sustainable Fashion

Fast fashion has been widely criticised for its excessive resource use and high generation of textile. To reduce its environmental impacts, numerous efforts have focused on finding sustainable and eco-friendly approaches to textile recycling. However, waste textiles and fibres are still mainly disposed of in landfills or by incineration and thereby pollute the natural environment, as there is still no effective strategy to separate natural fibres from chemical fibres. Herein, we developed a green chemistry strategy for the separation and regeneration of waste textiles at the molecular level. Cellulose/wool keratin composite fibres and multicomponent fibres were regenerated from waste textiles via ionic liquids. Our strategy attempts to reduce the large amount of waste textiles generated by the fast-developing fashion industry and provide a new source of fibres, which can also address the fossil fuel reserve shortages caused by chemical fibre industries and global food shortages caused by natural fibre production.