Plant-based plastics recycling breakthrough


4th February 2020

Scientists at Bath University have discovered a new way of recycling plant-based plastics to avoid them going to landfill.

This means plastics in food packaging, along with disposable cups and cutlery, can be recycled into identical products - a process that is currently impossible in the industrial recycling of plant based plastics.

The potential breakthrough could also mean drinks bottles would be able to be recycled to create other drinks bottles instead of being elements of other items.

The universities of Bath and Birmingham worked together on the study, using lower temperatures and environmentally-friendly catalysts to get their results.


Plant-based plastics - or 'bioplastics - are created from agricultural scraps such as corn, sugarcane, wheat or food waste.
The term 'plant-based' refers to the source of the material and not how the resulting plastic will behave after it's been thrown away.


Technically, it is possible to recycle most plastics. However the complexity and cost of doing so has prevented this happening in the past.
PET (polyethylene terephthalate) and HDPE (high-density polyethylene) are the most widely recycled plastics. They are used to make soft drinks bottles and milk bottles.

45% of plastic waste is recycled annually in the UK and this figure is increasing.
18bil pounds of plastic waste goes into the oceans each year from coastal regions.
That's the equivalent of five grocery bags of plastic waste sitting on every foot of coastline around the world.

Less than a fifth of all plastic is recycled globally.

40% of plastic produced worldwide is used just once.

Professor Matthew Jones from the Centre for Sustainable & Circular Technologies at the University of Bath said "Most plastic is currently recycled using mechanical methods, where they are chipped into granules and melted down before being moulded into something new."

'The problem is, melting plastic changes its properties, and reduces the quality, which limits the range of products in which it can be used"

"Our method of chemical recycling overcomes this problem by breaking down plastic polymers into their chemical building blocks, so they can be used all over again to make virgin plastic without losing any properties."

PLA is a plant-based plastic made from starch or crop waste such as dextrose (sugar) from corn.

Normal plastics are made from petrochemicals obtained from petroleum.

PLA is used in 'biodegradable' food packaging, disposable cutlery and disposable cups. It currently isn't recycled because it is not yet widely used.

The University of Bath say that the demand from consumers for recyclable packaging is growing as the awareness of plastic pollution is increasing.

The team have also started trialling a similar process for recycling a fibre called PET which is used for drinks bottles.

Dr Paul McKeown, First Author of the Paper, University of Bath said "PLA is being increasingly used as a sustainable alternative for single-use plastics. Whilst it’s biodegradable under industrial conditions, it doesn’t biodegrade with home composting, and isn’t currently recycled, so at the moment it commonly ends up contributing to the tonnes of plastic waste in landfill and oceans."

"There is no single solution to the problem of plastic waste – the approach has to be a combination of reducing, reusing and recycling. Our method of chemical recycling could allow carbon to be recycled indefinitely - creating a circular economy rather than digging more up from the ground in the form of fossil fuels, or releasing it into the atmosphere as a greenhouse gas."

The technology is in the early stages and only being demonstrated on a small scale. Through collaborating with the University of Birmingham they are working towards increasing the scale.

Circular Tayside

Circular Tayside is delivered by Zero Waste Scotland, Dundee and Angus Chamber of Commerce and Perthshire Chamber of Commerce. Circular Tayside is an initiative that: Raises awareness of the circular economy, the role the local businesses have to play in it, and how they will benefit. Facilitates collaboration amongst the local business community to enable our circular economy to develop. Supports individual businesses as they begin to identify and implement new and innovative approaches to businesses that support a transition to a circular economy Brings together a group of Circular Tayside Ambassadors who will be leaders in their sectors and champions of the circular economy.

Back to news