Baking powder for textile recycling
A group of young chemists from the University of Copenhagen has invented a simple solution using baking powder to recycle polyester, a blend of plastic and cotton.
With 60 million tonnes manufactured annually throughout the world and 85% ending up in landfills or being burned, polyester is the second most often used textile in the world. Cotton fibers are frequently lost during conventional recycling processes since the plastic is frequently preserved above all else. Due to the employment of metal catalysts, such processes are frequently expensive and complex and produce metal waste.
The Copenhagen team combined shredded textiles with a non-toxic solvent and Hartshorn salt (baking powder). For 24 hours, this is heated to 160 degrees Celsius (320 degrees Fahrenheit).
It’s a quick and affordable procedure, and the end product is a liquid in which the plastic and cotton fibers separate into various layers. explains Shriaya Sharma, co-author of the resulting work and a PhD student in the Jiwoong Lee group at the Department of Chemistry.
Ammonia, CO2, and water are produced during the breakdown of the hartshorn salt, also known as ammonium bicarbonate. Ammonia and CO2 work together as a catalyst to start a reaction that destroys the polyester while leaving the cotton fibers intact. Ammonia is poisonous on its own, however when mixed with CO2, it becomes safe to use. The cotton fibers stay intact because the chemicals used are relatively safe.
The new recycling method works on PET plastic alone, as well as on PET and cotton blended materials.