Sustainability Matters Aug/Sep 2022

Page 46

plastic recycling

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garbage

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esearchers from Sweden’s

Plastic recycling is generally inefficient

Chalmers University of Tech-

and only reclaims a relatively small amount

nology have developed a

of material for further use. The advanced

The researchers suggest that renewable

circular economy technique

recycling method proposed by the research-

energy can be used to power this advanced

that sees mixed waste con-

ers uses thermochemical technologies and

recycling process, which would be more

verted into raw carbon atoms to be used

sees waste being heated to 600–800°C to

energy efficient that currently used methods

in the production of plastic.

convert it to gas, after which hydrogen is

for disposing of mixed waste. Unused heat

added to subsequently produce plastic.

from the process could be harvested for

Mixed waste usually ends up in landfills

waste, and can be recycled using heat and electricity,” said Thunman.

or being incinerated. The Swedish scientists

“The key to more extensive recycling is

were looking to develop a technology that

to look at residual waste in a whole new

The research was carried out as part

could utilise molecules in plastic, paper,

way: as a raw material full of useful carbon

of the FUTNERC project, which is helping

wood and food waste, all of which are

atoms. The waste then acquires value, and

the chemical industry reduce greenhouse

full of useful carbon atoms that otherwise

you can create economic structures to col-

gas emissions. The processes have been

go unused.

lect and use the material as a raw material

tested through collaboration with a plastic

worldwide,” said Thunman.

manufacturer, Borealis.

“There are enough carbon atoms in

use elsewhere too.

waste to meet the needs of all global

The researchers were inspired by the

“Our goal is to create a circular economy

plastic production. Using these atoms, we

natural carbon cycle, whereby plants absorb

for plastics,” said Anders Fröberg, CEO of

can decouple new plastic products from

CO2 for nutrients and then release it back

Borealis. “Our plastic products are key to

the supply of virgin fossil raw materials,”

into the atmosphere when they die, where

the transformation to a sustainable society,

said Henrik Thunman, Professor of Energy

it is used again to grow more plants in

so it’s important for us to support research

Technology at Chalmers and one of the

the future.

like this. We already have projects that cre-

“However, our technology differs from the

ate circularity for our plastic products, but

“If the process is powered by renewable

way it works in nature because we don’t

more solutions are needed. Therefore, we are

energy, we also get plastic products with more

have to take the detour via the atmosphere

pleased with these excellent results, which

than 95% lower climate impact than those

to circulate the carbon in the form of carbon

can help bring us a step closer to our goal.”

produced today, which effectively means

dioxide. All the carbon atoms we need for

The study describing the technique was

negative emissions for the entire system.”

our plastic production can be found in our

published in the Journal of Cleaner Production.

authors of the new study.

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