There is no doubt that plastic waste is an enormous problem in today's society. Our ocean alone has a Great Pacific garbage patch, an accumulation of trash so large it is twice the size of Texas.
Considered the world’s largest zone of ocean plastics, it is estimated to contain up to 1.8 trillion pieces of debris that will not be decomposing any time soon.
Targeting polyolefin waste
Inspired by the need to reduce plastic waste, a team from Purdue University has developed a novel chemical conversion process that targets specifically the world's polyolefin waste. Polyolefins contain no harmful chemicals or by-products so they are often used in food packaging and obviously end up in our landfills and oceans.
The approach, say its inventors, could turn 90 percent of this type of plastic into many useful products, such as pure polymers and even fuels.
"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," said Linda Wang, the Maxine Spencer Nichols Professor in the Davidson School of Chemical Engineering at Purdue University and leader of the research team developing this technology.
"Our conversion technology has the potential to boost the profits of the recycling industry and shrink the world's plastic waste stock."
Converting to naphtha
By combining selective extraction and hydrothermal liquefaction, the scientists created a process that sees the plastic tuned into naphtha, a flammable liquid hydrocarbon mixture.
From there, the resulting naphtha can be used as feedstock for other chemicals or converted into specialty solvents or other products including fuels. The researchers estimate they can generate as much as 4 percent of the annual demand for gasoline or diesel fuels.
Wang is now on the lookout for potential investors or partners to take her team's technology to the commercial level. She argues that her work could inspire the recycling industry to do more about the current plastic waste problem in the word.
In fact, it was when she learned about our global plastics problem that Wang was moved to create her novel technology. And Wang argues that the problem is worse for our oceans.
"Plastic waste disposal, whether recycled or thrown away, does not mean the end of the story," Wang said. "These plastics degrade slowly and release toxic microplastics 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."
The study was published in the journal ACS Sustainable Chemistry and Engineering.