An Australian company banking on harnessing enzymes with the ability to chomp through plastic “like Pac-Man” has raised more than A$50 million (US$33.52 million) in a bid to turn waste recycling on its head.
The synthetic proteins, developed by researchers at Australian National University, can break down almost any plastic product into reusable high-quality components in a matter of minutes.
The by-products can then be used to create more plastic of brand-new quality.
“The enzyme ... comes along, and it literally just breaks the polymer chain, and then we just separate out the various components that are left over,” says Paul Riley, CEO of Aussie enviro-tech start-up Samsara Eco which has turned the research into a reality.
“It has the potential to be totally game-changing. It has the potential to move the dial on carbon.”
So convinced is he, Samsara aims to have a textile and bottle recycling plant up and running in Melbourne by the end of 2023.
Currently, only a small portion of clear and clean plastics put out for collection can be mechanically recycled. Most ends up in the landfill.
Even then, the process could be better described as ‘downcycling’ and can only happen about four or five times in the lifespan of the plastic, Riley says.
“Mechanical [recycling] is just a simple heat, melt and extrude process before its structural integrity degrades to the point where it ends up in landfill as well.
“So this technology is quite amazing - it’s virgin-equivalent monomer with no structural degradation at all.”
The product created is identical to virgin equivalent.
“We'll be intervening and diverting that product from landfill,” Riley says.
“We’re displacing fossil fuels from the supply chain” and perhaps best of all, the enzymes offer an option for “infinite recycling”.
Australia isn’t the only country to have developed plastic-eating enzymes - the technology is also being developed in France and US.
But in those cases, it takes 24-48 hours to break down the plastic. Some require it being held at a certain temperature for hours. It makes the carbon and economic cost of the process prohibitive.
Samsara’s enzymes require no heat, no pressure and take only eight minutes to break down any plastic.
“Because we can do it so fast, because we can do it in a continuous process, we can actually meet market price,” Riley says.
“So you have a recycled content now that meets market price.”
His team came across the technology while flicking through a magazine and reading about “all these motivated PhDs who wanted to make the world a better place”.
Those researchers have since joined Samsara with the single-minded goal of eliminating virgin plastic.
There are nine billion tonnes of the stuff and “every single piece of it’s still here on Earth”, Riley says.
The technology could help tackle issues like the growing ‘fast-fashion’ textile crisis.
“We’re not there yet, we’re working on our library of enzymes - we have four enzymes we have solutions for at the moment but ultimately we want to be able to process the mixed bale (of clothing),” he says.
“We can depolymerise all that clothing and turn it back into new fibre for reuse forever.”
Samsara has raised $54 million to scale up its operations over the coming year. The target is to be recycling 1.5 million tonnes annually by 2030 - no mean feat.
“But it is only 0.357 per cent of the world plastic market,” Riley says ruefully.
“It’s frightening, it’s sad and we need to do something about it.
“I’ve been saying for a long time, if you don’t solve the plastics crisis, you can’t solve the carbon crisis.”
