Chemical recycling makes useful product from waste bioplastic
A faster, more efficient way of recycling plant-based bioplastics has been developed by a team of scientists from the Universities of Birmingham and Bath in the UK.
May 25, 2020 by Canadian Plastics
Researchers from the Universities of Birmingham and Bath in the UK have developed a more rapid and more effective way of recycling plant-based bioplastics.
As reported in the Industrial & Engineering Chemistry Research journal, the team have shown that a chemical process, using a zinc-based catalyst developed at the University of Bath and methanol, can be used to break down real consumer plastics and produce a biodegradable solvent – called methyl lactate – that can be sold for use in an extensive range of industries such as pharmaceuticals and cosmetics.
The problem being solved is that bioplastics – produced from polylactic acid (PLA) – are commonly used in products such as packaging materials, disposable cups, and even children’s toys, but are either composted or disposed of in landfills once they come to the end of their service life. And they take several months to biodegrade.
The new technique was tested on three separate PLA products: a children’s toy, some 3D printer waste, and a disposable cup. They identified that the cup was most easily transformed into methyl lactate at lower temperatures, but even the heavier plastic in the children’s toy could be transformed at higher temperatures.
The chemical process has been tried up to 300 ml, so next steps would include scaling up the reactor further before it can be used in an industrial setting. The research was funded by the Engineering and Physical Sciences Research Council.
“The process we’ve designed has real potential to contribute to ongoing efforts to reduce the amount of plastic going into landfill or being incinerated creating new valuable products from waste,” said lead researcher Professor Joe Wood, at the University of Birmingham. “Our technique breaks down the plastics into their chemical building blocks before ‘rebuilding’ them into a new product, so we can guarantee that the new product is of sufficiently high quality for use in other products and processes.”