Single-use gets second life
Research in the US is giving single-use plastics a second chance.
A lab in the USA has developed a process that transforms single-use bottles, clothing and carpet into a more valuable material that has a longer lifespan.
Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have developed a recycling process that transforms single-use beverage bottles, clothing, and carpet made from the common polyester material polyethylene terephthalate (PET) into more valuable products with a longer lifespan.
Although PET is recyclable, most of the 26 million tons produced every year ends up in landfills or elsewhere in the environment, where it takes hundreds of years to biodegrade.
Even when it is recycled, the process is far from perfect. Reclaimed PET has a lower value than the original and can only be repurposed once or twice.
“Standard PET recycling today is essentially ‘downcycling’,” says senior author Gregg Beckham, a Senior Research Fellow at NREL.
“The process we came up with is a way to ‘upcycle’ PET into long-lifetime, high-value composite materials like those that would be used in car parts, wind turbine blades, surfboards, or snowboards.”
The team combined reclaimed PET with building blocks derived from renewable sources such as waste plant biomass.
This resulted in a new material that combines reclaimed PET and sustainably sourced, bio-based molecules to produce two types of fibre-reinforced plastics (FRPs), which are 2-3 times more valuable than the original PET, meaning that future plastic bottles could live lucrative second lives.
The team predicts that the composite product would require 57 per cent less energy to produce than reclaimed PET using the current recycling process and would emit 40 per cent fewer greenhouse gases than standard petroleum-based FRPs--a significant improvement over business as usual.
“The idea is to develop technologies that would incentivize the economics of PET reclamation,” says Dr Beckham.
“That's the real hope - to develop ‘second-life’ upcycling technologies that make single-use waste plastic valuable to reclaim. This, in turn, could help keep waste plastic out of the world's oceans and out of landfills.”
There is still much work to be done before this recycling process can leave the laboratory.
The team is testing a range of processes for scalability to determine how well it might fare in a manufacturing setting.
They are also working on composites that can themselves be recycled, as the current second-generation composites can last years and even decades but are not necessarily recyclable in the end.