A new invention could turn plastic waste into useful products

The oceans have been flooded by plastic waste with nearly 2 trillion pieces of plastic debris sloshing around in them, posing a constant threat to marine life.

Not even the deepest reaches on Earth have been spared the scourge of plastic pollution. Each year another 8 million tons of plastic waste ends up in the oceans, which means that by 2050 there might well be more plastic than fish in the seas, the United Nations has warned.

So far so bleak. A team of scientists at Purdue University in the United States say, however, that they may have a solution to clean up at least some of that massive volume of plastic waste. They have devised a chemical conversion process that could transform waste containing polyolefin, a form of plastic, into useful products like clean fuels and other items.

“Our strategy is to create a driving force for recycling by converting polyolefin waste into a wide range of valuable products, including polymers, naphtha (a mixture of hydrocarbons), or clean fuels,” explains Linda Wang, a professor of chemical engineering who was the lead author of a new study on the process. “Our conversion technology has the potential to boost the profits of the recycling industry and shrink the world’s plastic waste stock,” she stressed.

Her team has invented a method that can convert more than 90% of polyolefin waste into a variety of products from pure polymers to fuels. The process relies on extraction and hydrothermal liquefaction. Once plastic waste is converted into naphtha, it can either serve as a feedstock for other chemicals or else get separated into specialty solvents or other products. Clean fuels thus derived could supply 4% of the demand for gasoline and diesel fuels each year, the researchers say.

Of all the plastics produced over the past 65 years, only 12% has been incinerated and only 9% has been recycled. The remaining 79% has ended up in landfills or the oceans. “Plastic waste disposal, whether recycled or thrown away, does not mean the end of the story,” Wang explains. “These plastics degrade slowly and release toxic micro-plastics and chemicals into the land and the water. This is a catastrophe, because once these pollutants are in the oceans, they are impossible to retrieve completely.”

By reconverting waste into valuable products for reuse, we could create further incentives for businesses to invest into such forms of recycling, Wang says. The scientist and her team are looking for investors to start applying the technology commercially on a larger scale.