Sweden scientists develop medical plastics chemical recycling technology

Iranpolymer/Baspar Scientists at Chalmers University in Sweden have developed a chemical recycling technology that promises to close the loop on medical plastics.

The vast majority of medical plastic waste today gets landfilled or incinerated and the small share that gets recycled is downcycled to less demanding applications.

Whilst the waste problem posed by medical plastics is not comparable to that of packaging, it is still a substantial one. In Asia, the total medical waste generated is estimated at around 16,659 tonnes a day. Around 1.7 million tonnes of plastic waste are generated every year from US healthcare facilities.

To recycle medical plastics circularly, chemical recycling technologies are key to both eliminate risks from contamination and output building blocks for recycled plastic production with virgin-like qualities.

The researchers at Chalmers University collaborated with Borealis to develop steam gasification technology for carbon atoms recovery. The team tested the thermochemical process with face masks, plastic syringes, non-woven gowns, and nitrile gloves were tested at 700 C, 750 C, and 800 C in a lab-scale reactor.

The academics recovered a significant portion of the carbon in the waste feedstock in the form of olefins, ethane, and BTX. Lower temperatures of 700 C showed the best yield results, with carbon recovery percentages of approximately 79% for face masks, 82% for plastic syringes, 38% for nitrile gloves, and 76% for non-woven gowns. Higher temperatures reduced recovery due to secondary cracking reactions resulting in higher char formation.

“What makes this technology so exciting is its ability to handle the environmental challenges that we associate with medical disposables,” said lead author Judith González-Arias. “Thermochemical recycling not only addresses the problem that medical waste is not recycled today, but also facilitates the recovery of valuable carbon atoms. This is fully in line with the principles of the circular economy and provides a sustainable solution to the urgent issue of medical waste management,” she added.

To scale up the method, new material flows and functioning business models need to be established, in collaboration between the healthcare and recycling sectors. Laws and regulations at different levels may also need to be changed in order for thermochemical recycling to be widely implemented in society.

In Sweden, single-use items from healthcare do not create large enough waste volumes for a functioning circular business model. Around 4,000 tonnes of such plastic were put on the market in the country in 2019.

“To build a plant of the size required for profitable thermochemical recycling, you would have to ensure a material flow of around 100,000 tonnes per year before start-up,” said González-Arias.

She says that new collaborations would therefore be needed between several different actors for commercial thermochemical recycling, where healthcare waste could be part of the material flow.

The scientists shared their results in ‘Steam gasification as a viable solution for converting single-use medical items into chemical building blocks with high yields for the plastic industry’, recently published in Resources, Conservation and Recycling.

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