What’s new in clothing recycling?

Posted on 17 November 2020.

Under the European RESYNTEX project, Slovenian researchers have developed a new process for recycling clothing. This waste is transformed into raw materials that can be used in the biochemical industry.

Over nine million tonnes of textile waste, very often synthetic, are generated each year in the European Union.

The textile sector is the second most polluting industry in the world, after oil: in all, it represents 10% of global carbon emissions. According to the National Institute of Circular Economy, the current production, distribution, and use system is almost entirely linear with negative environmental and social externalities.
Under the influence of fast fashion, the production of clothing, very often made with synthetic fibres, has doubled over the last fifteen years, resulting in the generation of approximately 9.35 million tonnes of textile waste per year in the Union European, according to a study by Oakdene Hollins. This waste includes old clothes, of course, but also sheets, rugs, curtains, and even upholstery, of which only a small portion is recycled. 

How can this low recovery of waste be explained? In addition to being increasingly made from plastics, such as polyester, textiles are often treated with dyes and chemicals. This high degree of processing makes their recycling particularly difficult. To combat this enormous waste, the University of Maribor, Slovenia, in partnership with the textile company Tekstina and the Institute for environmental protection and sensors (IOS), has set up a demonstration laboratory for the chemical recycling of textiles. In this city with a population of 111,000, some 400 tonnes of textile waste are collected each year.

The project team decided to take up this challenge under the RESYNTEX project which aims to create more circular concepts for the textile and chemical industries. In the University of Maribor’s experimental laboratory, three machines transform old clothing into secondary raw materials.

The first step in this recycling process is the careful sorting of textile materials, such as wool, cotton, and polyester. Once sorted, the textiles are subjected to various processes, including bleaching, biochemical depolymerisation - namely, the transformation of textile fibres into simpler chemical compounds - and a hydrolysis-based treatment which decomposes a chemical substance through water. 
The chemicals obtained at the end of this process depend on the nature of the raw materials. For example, the research team can produce acids that can be used in the plastics industry from polyester; glucose juice, to be converted into bioethanol, is obtained from cotton; and the protein extracted from wool can be used as natural resin.

Best of all, researchers say the same technology can be applied to other types of waste.‘We use it on plastics, such as polyethylenes used in the manufacture of bottles. We are still testing cellulose packaging, which we are trying to degrade, as it is also a major environmental issue’, said Mojca Poberžnik. Work has only just begun