Chemists at the University of Copenhagen have made a significant breakthrough in textile recycling by developing an environmentally friendly method to recycle polyester using Harthorn salt. Polyester, which is the second most used fiber in the world, poses a threat to the environment as very little of it is currently recycled. The fabric is a combination of plastic and cotton, making it challenging for the industry to separate and recycle. However, the chemists have discovered a simple solution using a single ingredient found in households.
Polyester is found in various everyday items, such as clothing, sofas, and curtains, with an astonishing 60 million tonnes of the fabric being produced annually. Unfortunately, the production and lack of recycling have a negative impact on the climate and environment, as only 15% of polyester is recycled, while the rest ends up in landfills or incineration, contributing to carbon emissions.
Recycling polyester presents significant challenges, particularly in separating the plastic and cotton fibers without losing them. Traditional methods prioritize preserving the plastic components, resulting in the loss of cotton fibers. These methods are also expensive and complex, with the use of metal catalysts generating harmful waste.
In a revolutionary development, a team of young chemists has found a remarkably simple solution to this problem that could transform sustainability in the textile industry. The researchers have developed a traceless catalytic methodology that allows for the depolymerization of polyester into monomers in an easy and environmentally friendly approach, at a large scale.
The process requires no special equipment and only relies on heat, a non-toxic solvent, and common household materials. By cutting a polyester garment into small pieces and placing them in a container with a mild solvent and Harthorn salt (ammonium bicarbonate), the mixture is heated to 160 degrees Celsius and left for 24 hours. The result is a liquid where the plastic and cotton fibers separate into distinct layers. This simple and cost-effective process preserves the cotton fiber while breaking down the polyester.
The Harthorn salt is broken down into ammonia, CO2, and water during the process. The combination of ammonia and CO2 acts as a catalyst, selectively breaking down the polyester while keeping the cotton fibers intact. The use of ammonia in combination with CO2 is environmentally friendly and safe. Due to the mild nature of the chemical reaction, the cotton fibers remain in excellent condition.
The researchers were pleasantly surprised by the success of their simple recipe for recycling polyester. Although the method has only been tested in the laboratory, the researchers believe it is scalable and are currently exploring partnerships with companies to test the method on an industrial scale. They are determined to commercialize this technology, which has the potential to make a significant impact on textile recycling.
Source: scitechdaily.com
