Scientists discover new bioplastics recycling method

Scientists from the Universities of Birmingham and Bath have published findings on a new chemical recycling method for plant-based bioplastics.

An image of biochemicals

Researchers at the Universities of Birmingham and Bath claim their new chemical recycling method not only speeds up the process of recycling bioplastics but can also create a new product – a biodegradable solvent – which can be sold for use in a wide variety of industries, including cosmetics and pharmaceuticals.

Publishing their results in the journal Industrial & Engineering Chemistry Research, the scientists show how consumer plastics can be broken down through a chemical process into a green solvent called methyl lactate by using a zinc-based catalyst and methanol.

Bioplastics, made from polylactic acid (PLA), are becoming increasingly common in products such as disposable cups, packaging materials and even children’s toys. Typically, once they reach the end of their useful life, they are disposed of in landfill or composted.

The team tested their method on three separate PLA products – a disposable cup, some 3D printer waste, and a children’s toy. They found the cup was most easily converted to methyl lactate at lower temperatures, but even the bulkier plastic in the children’s toy could be converted using higher temperatures.

Commenting on the findings, Luis Román-Ramírez of the University of Birmingham’s School of Chemical Engineering, said: “We were excited to see that it was possible to obtain high quantities of the green solvent regardless of samples’ characteristics due to colorants, additives, sizes and even molecular weight.”
Lead researcher Professor Joe Wood at the University of Birmingham added: “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.

“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.”

The findings from University of Birmingham and Bath’s scientists follow recent developments within the plastic chemical recycling sector. Earlier this week, waste management company Viridor announced that it had commenced feasibility work on a new project with chemical recycler Plastic Energy to deliver predominantly low-density plastic film to a new Plastic Energy chemical recycling plant, where it will be turned into an oil product called TACOIL. This oil would then be used as a feedstock to create new virgin plastic.

Last month, chemical recycling company Recycling Technologies announced that the Netherlands will be the location of its first site in Europe. Its plastic chemical recycling RT7000 machine turns low-grade plastic waste into a feedstock trademarked as Plaxx®, used for new plastic production.

Recycling Technologies has also put its weight behind a global consortium to develop a chemical recycling industry in France, examining the technical and economic feasibility of recycling complex plastic waste.