Swedish researchers are transforming old clothes into sugar

WHAT if we were able to recover cotton from used clothing and turn it into nylon or lycra? This is the surprising idea of Swedish researchers, who have developed an environmentally friendly method to convert textile cotton into glucose, which in turn can be used to make other fabrics.

Did you know that even when you donate clothes, they are likely to end up in a landfill or incinerator? To avoid this fate befalling our cotton clothes (a material whose production has a heavy impact), scientists at the Department of Chemical Engineering at the University of Lund in Sweden are currently working on a method to recycle the cotton from used clothes.

Described in the publication Waste Management via ScienceDirect, their method is innovative: extracting cotton from clothes, then transforming them into glucose, thanks to sulfuric acid. Concretely, the principle consists in decomposing the vegetable fiber of cotton (cellulose) in order to obtain smaller pieces. The fabrics are then soaked in sulfuric acid. The result is an amber-colored liquid. A standard fabric scrap represents about five liters of sugar solution, each of which contains the equivalent of 33 sugar cubes.

Edvin Ruuth, a researcher in chemical engineering at Lund University who led the study, explains that glucose is a very flexible molecule with numerous uses. "Our plan is to produce chemicals which in turn can become various types of textiles, including spandex and nylon. An alternative use could be to produce ethanol," Ruuth outlines.

Within one year, Edvin Ruuth's team managed to obtain 90% cotton-derived glucose, compared to 3-4% at the beginning of their experiment. The next step is to develop the logistics in order to obtain enough sorted textile material. There is no sorting center where garments can be selected according to their recyclability or fiber size, except for garments collected via collection points.

However, the researchers are counting on a future center currently under construction in Malmö (southern Sweden), where clothing will be sorted automatically using sensors. Some of the clothing will be donated and scraps of fabric can be reused in the fashion industry, including textile materials whose fibers are large enough to be transformed.