A recycling revolution: turning plastic into steel
24 June 2019 : Shared in full from Simplicite blog:
The “recycling crisis” that local councils in Australia say they face will end before too much longer.
Before now, Australia’s solution to waste has been to bury it or export it to China. However, many of our landfill sites are full and early last year China placed a ban on the importation of a range of Australian rubbish.
Enter Australian engineer Veena Sahajwalla, who is changing the recyling industry with her “revolutionary” idea of using plastics and rubber in steel production.
This information presented here is from a subscriber-only article by journalist Greg Bearup. It appeared in The Australian newspaper 4 May 2019.
Hungry beast of big metal furnace ‘eats’ recycled plastic
Veena Sahajwalla, dressed in a hard-hat and a blazing safety coat, is bouncing with excitement in her steel-capped boots. She’s one of the world’s leading experts in the field of recycling science, the toast of academia, but it’s obvious there are few places she’d rather be than here, in the control room of an electric arc furnace at this Newcastle steel mill. She can’t wait to step through the door and onto the floor where a raging torrent of heat is rendering steel into liquid.
“Greg,” she says, leaning in to be heard above the cackle of the furnace. “It’ll make me sound like a pyromaniac [but] I love all this high-temperature stuff. Everything to do with big, hot furnaces.” She gives me a cheeky smile and a hint of Indian head wobble. “I love the whole hungry beast of a big metal furnace. It works for me.” Then, beaming with awe and wonder, she steps through the door to be greeted by the hot breath of the beast.
Engineer Veena Sahajwalla in her lab
Sahajwalla is a world leader when it comes to this molecular alchemy. Australian steel makers have commercialised her groundbreaking invention known as Green Steel — using the carbon in old car tyres to replace coking coal in steel production. Her technology has been patented and exported around the world, used in the production of more than 30 million tonnes of steel. Last year she was made a fellow of the esteemed Australian Academy of Science.
Recycling plastic junk into steel
Today, here in Newcastle, she is taking her technology one step further. This furnace is using coke to provide the vital carbon in the scrap steel recycling process, but trials are underway that will see it transition from coke to rubbish — shredded plastics that, like coke, are packed full of carbon. The plastics will be funnelled into the middle of this furnace at more than 1500 degrees where there’s no oxygen so it doesn’t burn. The carbon in this junk becomes a vital element in the steel.
For more than a century they’ve been making steel on this site at Maud St, Waratah, a suburb of Newcastle; they currently produce train wheels and axles and grinding balls used in mining. During World War II the mill made 200,000-odd artillery shells and other munitions. If your grandpa fought in the war, chances are he was capped with a steel helmet made by the blokes at the old Commonwealth Steel Company — more than two million were shipped out through the gates at Maud Street to Allied soldiers.
What may surprise many is that this steel mill still exists — didn’t we offshore all this already? It went through some lean years and several owners, and is now in the hands of a US company, Moly-Cop. And on the day we visit, there’s a sense of great optimism among the workers. They’ve witnessed the alchemy of trash being transformed into valuable products. They’ve seen the future and it is in breathing new life into old rubbish.
Going green by burning plastic
The Newcastle steel workers were dubious when Sahajwalla first suggested replacing coke with plastic but they’ve discovered it’s actually significantly more efficient and less toxic than the coke. Going green, they say, gives them a competitive advantage. They’ve taken on Sahajwalla’s ideas with gusto and recently began experimenting with a process that transforms old photocopiers and their endless toner cartridges into bespoke carbons that can be used in batteries.
And now, in partnership with Sahajwalla and her team at the University of NSW’s Sustainable Materials Research and Technology (SMaRT) centre, they are working on the Holy Grail, feeding their furnaces with car “flock”: the glass, leather or vinyl seats, plastics, tyres and e-waste that’s left over when the car has been stripped of its metals. Tens of thousands of tonnes of flock end up in landfill each year. Moly-Cop has begun trials, feeding it into its furnaces in a process called thermo-micronising to extract the valuable stuff.
Recycling possibilities are endless
The possibilities for this 100-year-old mill, Tooze says, are now endless. “Why couldn’t you start a battery-making plant up here? Why couldn’t you start an electrode plant, because all the raw materials are here… I can see a world where we are creating all these regional jobs, feeding all this material back into the supply chain.”
The former deputy vice-chancellor of UNSW, chemistry professor Les Field, says it is difficult to overstate the contribution Sahajwalla has made to science “and to Australia more generally”. He says her idea of using plastics and rubber in steel production is “revolutionary” and, because she’s been able to communicate with industry so successfully, her idea has gone from the lab to a commercial reality in a very short space of time.
“She has been an absolute role model and a great champion for women in engineering and women in STEM,” Field says. “She is an incredible flag bearer. Engineering and recycling is normally considered a relatively dirty, male-dominated environment… I can’t stress how important her role in this has been.” And, he adds, she’s a wonderfully generous person. “She relates to workers on the shop floor as easily as she does the world’s leading scientists. She’s a stunning individual, a truly remarkable individual.”
Field says our society has not yet come to terms with the urgent need to re-use our resources. This is, he says, one of the great environmental challenges. “We have not grasped it and we have not engaged with that issue anywhere near as much as we should have. We’re tinkering around the edges, lurching from crisis to crisis with these mountains of recyclable materials.”
Featured on The New Inventors
But one woman’s truckload of rubbish is Sahajwalla’s truckload of treasured elements. “What I love about Veena,” says the broadcaster James O’Loghlin, who featured her as an expert panellist on his ABC show The New Inventors, “is that she motivates people to do the right thing by the environment, not necessarily because it is the right thing to do, but because it is cheaper and more efficient. She points out the opportunities.”
I meet Sahajwalla at her office at UNSW to talk about some of those opportunities. It’s the afternoon and she’s running late; her secretary asks if I would like some samosas. “Veena will be starving, she’ll need to eat,” she explains. Sahajwalla sweeps into the room, a bundle of enthusiasm and charm.
Sahajwalla nibbles on her samosa and explains that when she was growing up in Mumbai, nothing was wasted. Someone would turn up to collect bottles, someone else would collect paper, others old pots and pans and clothing. These people made a living out of junk. Like them, we’ve got to start seeing rubbish as an opportunity, she says. Enormous effort went into finding these resources, then mining, then processing and shipping them, so why would you throw them away?
“All of this waste contains valuable elements,” she says. “We’ve got to start looking at this from that perspective — what are the elements we can use? We should be saying to the world, please put all your hard drives, all your circuit boards, all those lovely plastics into shipping containers and send it all over to us. We will store it and we will find a use for it at some time. Or we’ll come to you. We’ll come to you with our micro-factories, with our IP, and we’ll process it right there for you. And you pay us and then we’ll sell you cobalt and then you can pay us more for that as well.”
Turning old clothing into building materials
She segues into telling me about one of the projects she is working on, turning mountains of old clothing into building panels. “Just because a garment is no longer wearable doesn’t mean that the material is no longer useful,” she says. “You haven’t actually lost its basic elements. Whether it’s a fibre in a textile product or it is a compound, whether it’s a molecule, fundamentally those basic building blocks are still there. So why not take those fibres and literally reform and restructure it into a whole new product?”
Sahajwalla with tiles made from old clothing waste
Last year her SMaRT centre opened the world’s first e-waste micro-factory to process old computers, phones, televisions — all the electronic junk that ends up in landfill. The waste is sorted and dismantled by robots and then mined for its precious elements. Circuit boards are stripped of metals such as copper and tin, while glass and plastic are converted into industrial-grade ceramics and plastic filaments that are used in 3D printing.
The e-waste plant is the first in a series of micro-factories under development. There are plans to develop factories that can turn a range of consumer waste, such as glass, plastic and timber, into commercially viable products. The idea is to set these small factories up alongside regional waste disposal dumps to process the waste at its source. The eventual aim is to finetune these micro-factories and have Australian companies export the technology around the world.
All of this takes money, of course. Sahajwalla says governments and the public need to view money spent on research and development in this field in the same way they view the investment in medical research and public health. “It’s a weird comparison,” she says, “but if you think about research into health, right, it is important because it’s not just about people’s lives but there is an economic underpinning to the argument. If we’re all healthier and we all proactively do the right thing from a health point of view, it has better outcomes for the individual, better outcomes for their families and ultimately the economy.” Developing these recycling methods is expensive but over time the costs come down and the benefits to society are immense. “We may not have all the answers today but we may well tomorrow,” she says.
A vision for better recycling
Michael Sharpe of the Advanced Manufacturing Growth Centre in Sydney has taken Sahajwalla on numerous tours to regional centres such as Dubbo, Bathurst, Albury and Taree. She’s visited flour mills, boat builders, kitchen cabinet manufacturers, bakers and waste recyclers.
“It’s often the case that universities and industry speak different languages,” Sharpe says. “Veena is one of the world’s leading researchers but she can break that down into simple language.” She understands that these people are trying to make money and that her concepts for recycling have to share that aim.
We need better systems
Sahajwalla tells me she is excited about the future but says governments, industry and individuals need to make recycling a greater priority. We have to start picking the low-hanging fruit.
“We need better systems in place for the sorting of recycling,” she says. “We need places in every suburb where people know they can drop off all their old computer parts and remote controls. They need to be able to take all their food packaging back to where they bought it.”