Scientists develop new method to rapidly break down plastic waste using air.

Northwestern University scientists have developed a simple, non-toxic, fast, and eco-friendly method to decompose plastic waste using air, which is expected to help address environmental pollution issues.

In a press release issued earlier this month, Northwestern University researchers disclosed that they utilized inexpensive catalysts to break down the chemical bonds in polyethylene terephthalate (PET), the most common plastic in the polyester family. PET is commonly used in food packaging and beverage bottles, accounting for 12% of global plastic consumption.

The researchers then exposed the plastic fragments to ambient air, using trace moisture in the air to convert the decomposed PET into terephthalic acid (TPA), a key component of plastic. TPA can be recycled to make new plastic products or other valuable materials.

Traditional methods of plastic decomposition often require high temperatures, large amounts of energy, and solvents that produce toxic byproducts. The catalysts used in these reactions are typically expensive or toxic, leading to the generation of harmful waste.

In contrast, the new method developed by Northwestern University researchers is solvent-free. The catalyst they use is not only non-toxic but also cost-effective. The only byproduct in the entire decomposition process is acetaldehyde, a valuable industrial chemical that is easily removable.

The process is rapid and efficient, with 94% of TPA recovered in just 4 hours. The catalyst is durable and recyclable, retaining its effectiveness even after multiple uses.

When tested on real-world materials such as plastic bottles, shirts, and mixed plastic waste, the process proved equally effective, even breaking down colored plastics into pure, colorless TPA.

One of the authors of the study, Assistant Professor of Chemistry at Northwestern University, Yosi Kratish, emphasized the urgent need for improved technologies to handle various types of plastic waste, given that the United States is the top contributor to per capita plastic pollution, with only 5% of plastic being recycled.

Another key author of the study, Naveen Malik, a former Northwestern University postdoctoral researcher now serving as an Assistant Professor at SRM Institute of Science and Technology in India, highlighted how their research offers a sustainable and effective solution to plastic waste, one of the world’s most pressing environmental challenges.

Malik emphasized that their technology has the potential to significantly reduce plastic pollution, lower the environmental footprint of plastics, and contribute to a circular economy by promoting the reuse of materials rather than disposal. This innovative approach showcases how creative chemistry can confront global challenges in a manner harmonious with nature.

The researchers plan to scale up the industrial application of this technology to ensure it can handle large volumes of plastic waste successfully.

The findings of the study were published in the Green Chemistry Journal.