Veena Sahajwalla (UNSW): Valued resources from recycled wastes

Kourosh Kayvani & Veena Sahajwalla | 30 January 2019 | 25:32

Podcast transcript: Veena Sahajwalla (UNSW): Valued resources from recycled wastes

Kalay Maistry: Welcome to the second episode of Engineering Reimagined. I’m Kalay Maistry. Humanity depends on engineering to help solve the wicked problems our world faces. In this podcast series we explore how, like engineers, people from all walks of life are reimagining the future and their leadership roles in it.


If global food waste was a country, it would be the third largest greenhouse gas emitter behind China and the US. This is just one of the alarming statistics about waste in our world.

Yet, look into any tip in any country and you will find mountains of rubbish packed with useful elements such as carbon and hydrogen, together with materials like silica, titania and metals. These are valuable materials that industries would otherwise source from virgin resources to make new products.

In engineering, most of the discussion around sustainability focuses on design; however, today’s conversation is focused on materials. Specifically, on waste and the groundbreaking work taking place on how it can be recycled back into the ecosystem.


Kalay Maistry: Today’s interview takes place between Professor Veena Sahajwalla and Dr Kourosh Kayvani. Veena is an internationally recognised inventor and professor of Materials Science at the University of New South Wales. She is a founding director of the university’s Centre for Sustainable Materials Research and Technology, an Australian Research Council Laureate Fellow and many listeners in Australia may remember her as a long-serving judge on the ABC television’s The New Inventors.

Interviewing Veena is Dr Kourosh Kayvani, the Managing Director – Design, Innovation and Eminence at Aurecon. In his nearly 30 years in the industry, Kourosh has played key roles in the engineering of many innovative structures across the globe, including Wembley Stadium in the UK, West Kowloon Terminus in Hong Kong and high-profile projects in Australia. Kourosh and Veena are both award-winning experts in their field, too many to mention here. Sit back and enjoy their chat: will they be talking garbage? You bet.


Kourosh: Veena is revolutionising the science of recycling to help global industries safely use toxic and complex waste as low-cost alternatives to raw materials and fossil fuels. Veena's passion focuses on mining the mountains of rubbish and waste materials produced by modern society, and reusing them in industrial processes to create new goods.

Veena, one of your major breakthroughs came when you invented an environmentally-friendly process that recycled rubber tyres from used cars into parts replacement in steel-making. Your process was patented, won multiple awards, required less energy, reduced carbon emissions and reframed rubbish as a valuable resource. The first question I have is, why had no one else thought of doing this?

Veena: Sometimes it’s one of those discoveries that actually happens because you've thought about the science for so long it was very much about saying, "Well, you know steel-making requires all kinds of exciting high-temperature chemical reactions”, so it's about where, at the molecular level, we can source these types of inputs from? People may realise that steel is nothing but an alloy and, at the very basic level, it's iron and carbon and potentially many other elements.

So, the ability to in fact have another source that can offer carbon as a fantastic resource in that process of making steel was really something that came about as a result of one of those moments when you're sitting and looking at the phenomena in your labs, and you actually are going, "Wait a minute. Actually, at such high temperatures, the transformation of complex materials takes place to the point where we can reform those fundamental molecules." Steel-making temperatures are so high that at 1550 degrees Celsius, you're triggering off that transformation. What we've done is reform that complex tyre into these absolutely simple molecules of gas. That's really where it's exciting to think that we should be looking at materials not just simply at the macro level, a big tyre, but rather, if you could zoom down at the micro level, and you could actually reimagine what those elements might look like under different manufacturing conditions. There should be no limits in the way we look at how our resources are in fact being sourced, to me, it's absolutely fascinating and mind-blowing and that's why I love engineering so much.

Kourosh: Well, it's fascinating indeed. In your process, we're not only repurposing waste, not creating more waste on our planet, we're actually creating an improved product, so you're turning waste to valuable assets.

Veena: Yeah, yeah.

Kourosh: It gives you a steel with characteristics that are better than normal steel.

Veena: The reason why we're looking at you know metals like steel and copper, we can source them from a lot of waste resources. Steel is already produced in many parts of the world from scrap metal, so scrap steel is converted into new steel, but the process of making this new steel in electric-arc steel-making is something that's been around for a long time. However, the carbon that actually goes into that steel-making process has traditionally relied on coal and coke-based resources. So, our ability to actually bring in new raw materials, now you might say, "Well, it's not really new." It's the good old tyres, for example, that we've used in the process, but the process and the way we use these tyres is completely new.

In that context, our ability to source these types of resources from waste is actually a huge win for our economy. It's a fabulous way to showcase engineering innovation in so many different ways. It's ultimately about creating products that are good for humanity, and so, if we are going to make products that are good for humanity, we've got to go back and think about where our materials are coming from.

Kourosh: Absolutely. I love your focus on material as the core to the next step on sustainable design, and so much effort has been put into the design itself, but it has, in recent times, been more around using existing, conventional material for sustainable design. You're going back to the core material level, which is really, I think, the Holy Grail of getting real step change in sustainable outcomes for us.

Veena: We're not just looking at it as a recycling challenge that we're converting plastics into plastics, or glass into glass, but rather, we're seeing it as a whole new way to do manufacturing. And that's why we like to talk about our work, really, as more micro recycling, which is what I'm excited about because it helps us actually reimagine our materials in a completely different way for different applications. Micro recycling can be seen as a more advanced version of traditional recycling. We need to be very, very careful in the way we deal with our end-of-life products and materials and not just think about putting them away into landfill.

Kourosh: Where are we at with the industry uptake of this process in terms of percentage of steels being made using this recycled tyre approach?

Veena: We've been very, very privileged that we've got industry partners in Australia and of course, in other parts of the world who have been excited about the technology. We've indeed commercialised this technology in Australia and overseas, and that's been an absolutely fantastic privilege for me and our team. When you collectively look at the number of tyres that we've recycled as a result of this Green Steel Technology in Australia and overseas, we've actually exceeded 11 million tyres globally using our technology.

Kourosh: That is wonderful. What inspired you to become an inventor?

Veena: As they always say, curiosity is certainly a factor, but I think there's got to be a little bit of a craziness factor somewhere in there as well. Sometimes, it's okay to be kind of a little crazy and thinking outside the box, of course, and challenging the norm to be able to go off and challenge the way things have traditionally happened in different industry sectors, and have those difficult questions that you should be prepared to answer.

And I think on that journey, somewhere in there, you stumble upon your own thoughts that actually give you that brilliant ‘aha’ moment. I can tell you, there is no better feeling than when you hit upon ... It's almost that conversation you're having with yourself, which I think is the best part because, as you're challenging your own thinking about how you've been thinking about something, when you stumble upon it in your own thought process, that’s sort of new way of thinking about something. It's a brilliant feeling, and I love being an inventor because, to me, I think that's the best reward you can ever get in your work.

Kourosh: That's fascinating. I guess the outcome is for all of us to see. The second question for you on that note is, why the field of waste? What inspired you to focus on that area?

Veena: There are a few elements as to why I was passionate about waste from early days when I was a kid growing up in Mumbai, because I mean one thing is, of course, in places like Mumbai, you do see waste everywhere. But, as people may know there are many, many people who make a living as waste pickers, and I think to me, that's a very important function. A society cannot exist if we don't have that very important function, so it's an important part of our everyday lives. Particularly, in so many developing economies where we hear stories about where people work under some very horrific conditions, working with really difficult waste materials.

There was also an element that we are not recognising and rewarding people who work in that space. What if we could value add, so that it doesn't just stop at picking and collecting waste, but rather also transforming them into value-added materials and products? And, of course, you know we want to be able to make it safe for everyone. We want to make sure that people are working under conditions that are safe, that we would consider acceptable.

Kourosh: So, it was a combination of intellectual curiosity and that emotional element of adding ‒ improving both social and environmental outcomes based on what you've experienced growing up.

Veena: Absolutely, absolutely. We're human beings. We are people with emotions. I think it's very important that we are guided both by our passion and of course, our heads, so our heads and our hearts both have to prevail. That's why I guess I love what I do because I feel I am using my skills, both technical skills, as well as what I believe in and what I'm passionate about. I can bring all of that to my work. I see so many inspiring young people who are equally passionate about all of these issues. I think the world is a better place when people bring their passion to their work every day.

Kourosh: I'm very interested that the younger generation see within engineering not only the ability to solve complex problems but also have a high impact to society. That really draws a lot of new generation of engineers to bring that social good as an outcome of what they do.

Veena: Absolutely, and I think that's such an important element that we're really blessed that we've got so many young people who care, genuinely care for social issues, and the fact that engineering is now so much more than just addressing the technical challenges and complexities.

Kourosh: As I often say these days, engineering is one of the last remaining humanitarian professions on the planet, so I think we're very pleased to hear the same message from you. If I may move on back to the topic of waste, why is waste so complex?

Veena: Waste is a complex material because, of course, we've effectively created all kinds of sophisticated products for our everyday needs, so, whether we talk about even something as basic as phones or we talk about the windscreen glass in our cars, at the end of their lives, they are complex because they are not just always a single material. They could be laminated products like the windscreen glass. They are laminated because they're designed to be safety products that don't go off and hurt us in case of an accident. So, at the end of its life, it's not just as simple as saying, "Well, let's treat it like any other glass and put it into a glass melter for recycling.” It may not be as simple as, "Why don't we just delaminate it and solve the problem?" Our good old humble chip packets, in which we see metalised lining on the inside and plastic on the outside, is another good example of a laminated product. The metalised lining inside is still a very useful material, and so we need to be able to harness those types of materials through innovation and bring those back to life.

Kourosh: The topic on waste has grabbed a lot of media attention in recent times, and it appears there is an elevated level of awareness among the general public about waste. How has that impacted your research and your work?

Veena: Yeah, you know, it's interesting. I mean we've been researching in waste transformation for many, many years at the SMaRT Centre at the University of New South Wales. I think it was almost one of those things where I would have this crazy conversation with myself going, "Why are we not doing more in this space?" It was really nice to be able to see that recognition where indeed, now, with all the attention that waste has received, particularly this year in 2018 when we've had that transformation coming in, into our thinking in our society and saying, "We need to be able to do something more and not just think of it as sending it away to other countries for further processing."

To me, it's like anything else: never waste a crisis. Yes, it is seen as a crisis, and I do agree that it's going to mean that we're going to have to all come together as businesses, as researchers, as communities to develop those solutions.

Kourosh: Fascinating. As a follow-on question to that, the reports in the media about the discovery of micro plastics in human waste alarmed a lot of us.

News clip: Microplastic particles have been discovered in human waste for the first time ever, according to The Guardian. The findings came from a study of eight people from Europe, Russia and Japan, conducted by the Environment Agency Austria and microplastic particles which are pieces of plastic, smaller than 5 millimetres, were found in every participant’s stool samples. Nine of the 10 different plastics researchers tested for were found in their waste. There’s some concern that the circulation of microplastics could have negative effects on the human body, including the immune system. I guess reflecting on that, what are your thoughts about this notion of plastics getting into the ecosystem effectively to a cycle of, an effect on health and other things?

Veena: Yeah, absolutely, a very important question. This is exactly why we need to think about materials and manufacturing and processes in a holistic manner. We can't afford to have things like that happen, whether it is to marine environment, whether it is to us as human beings. If that ends up in our ecosystems as you have rightly pointed out with these micro plastics, the long-term consequences could be absolutely horrific. We need to think right from the very beginning when we are developing products in how those products are going to be dealt with at the end of their lives. We shouldn't allow these types of harmful negative consequences to occur, which means there's got to be responsibility where producers have to take back a lot of the products, and of course, people talk about extended producer responsibility. In many parts of the world, that is a reality where producers have to take back. To me, that should be part of our normal thinking.

Why should we, for example, have to deal with packaging in our homes? I'd say if you bought something in a store somewhere, the store owners should actually be prepared to take the packaging back, and you should just take the product home, or you should be able to bring the packaging back to the store. I think that chain of responsibility has to begin with consumers actually saying, "No. You know what? I don't want unnecessary packaging. I need to be able to bring it right back to the store." If we, as consumers, start to think about this important issue, we can actually have a huge impact, much, much more than what we even realise. That's what I think we can look forward to, in a way, shaping a better collective future for everyone.

Kourosh: Is the concept of zero waste future ever realistic?

Veena: Look, I like to think of waste as a material that is waiting to be loved. I guess it’s a good way to look at it. Its properties and its qualities are yet to be recognised. If we can take different types of waste materials on that journey with us as we think about meeting the needs of society. Looking at manufacturing as a way to address those challenges and incorporating more and more waste into our regular thinking in terms of how those resources can be utilised. When that becomes the norm, where people would naturally go out and seek different types of products and materials as part of their manufactured solutions, then we will absolutely be able to see a future where waste is no longer even thought of as waste. In fact, it's just waiting to be transformed. So, absolutely, I do believe that zero waste is a very real possibility. I think for the sake of our planet, we have to head in that direction.

Kourosh: On the concept of zero waste and given our increasing use of technology, what does the future of e-waste look like?

Veena: Well, electronic waste is something that we all have to accept that we're playing a part, somehow or the other. We all have TVs and phones and laptops, so it's not that we're not playing a part in it. Every human being is playing a part, and we in fact have seen, in so many developing countries, where people have just skipped past the landline phone and gone straight to mobile phones, for example. To me, that is a fabulous way to empower people no matter where you live in the world. I think the ability to have these devices and have devices that are going to be affordable is an important point. If indeed we are going to continue to have affordable solutions so that our phones, for instance, our mobile phones can be put in the hands of everyday citizens no matter where you live because it is so empowering for our everyday lives. Well, how are we going to make sure that the actual materials that go into manufacturing those devices are also accessible and affordable?

In that context, e-waste is going to have to play an important role. We're going to have to look at ways in which we can reform those materials into valuable metals, for instance, so that we can put them right back into manufactured products. So, along with traditional manufacturing, that of course exists in many parts of the world, we can in fact look at micro factories as another solution, so that, then becomes far more affordable and accessible for manufacturing solutions and bringing e-waste, as an example, back to life in different forms.

Kourosh: What further thoughts do you have on the impact of technology, new technology in particular in your work?

Veena: The ability to have micro factories that are really agile and flexible, that's an important point because you can then imagine a situation where you can literally have a mobile micro factory that can move around in so many regional communities. And towns that traditionally never had a factory operating in their town, but you can imagine, if you did have these mobile micro factories that were then able to actually move across into different towns, that will then enable us to reimagine how we actually think about manufacturing.

Kourosh: You said earlier that what drew you in to become a scientist, and inventor and particularly in your area was the combination of intellectual curiosity and that, I guess, emotional element of feeling that there is something you can do to improve in terms of society and environment. Is that still relevant, or has your way of doing what you're doing changed over time? Have you had to reimagine your career as you went along?

Veena: Well, you know, fundamentally, as human beings, I certainly do believe that after a certain point, you never really change. I'll always be someone who cares for human beings in a way that I know I can bring the engineering skills and the scientific ability that I have to be able to help everyone think about new solutions.

Kourosh: Thank you. That's a really wonderful story. Thank you so much, Veena, you've been very generous with your time and also with your thoughts and ideas you shared. I can urge my colleagues in engineering community to follow your path and become more of a spokesperson for the work we do.

Veena: Thank you so much for having me and it's been an absolute pleasure speaking with you, Kourosh.

Kalay Maistry: We hope you enjoyed this conversation. Don't forget to share this episode on social media and leave a review for us where you’re listening – we want to know what you think! Tell a friend or colleague about us, they can find the podcast by searching Engineering Reimagined wherever they listen to podcasts.

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Veena Sahajwalla's passion for recycling has led to innovative discoveries

How can we repurpose waste into valuable assets? Former Aurecon Managing Director for design, innovation and eminence Kourosh Kayvani chats with materials engineer and inventor Veena Sahajwalla about revolutionising recycling to help industries repurpose waste as a low-cost alternative to raw materials and fossil fuels.

IIn this episode of Engineering Reimagined, Veena shares her breakthrough invention of recycling used rubber tires from cars into parts replacement in steel-making, inspiration in becoming an inventor and the role of art and design in scientific disciplines. We also explore the concept of micro-recycling, the future of e-waste and green micro-factories.

“The fact that waste materials are complex, but yet, they offer us this beautiful opportunity to manufacture products so that we can actually be so much more sustainable in the way we make our materials and our products, to me, it's absolutely fascinating and mind-blowing,” says Veena.

Meet our guest and host

Learn more about Veena Sahajwalla and Kourosh Kayvani.

Kourosh Kayvani

Kourosh Kayvani

Former Managing Director – Design, Innovation & Eminence, Aurecon

Kourosh provides leadership, deep insight and professional passion towards mobilising company-wide expertise to solve the critical and complex problems our clients face, and has a focus on company-wide innovation. He has played key roles in the design and delivery of many innovative, complex and award-winning projects across the globe, including Wembley Stadium in London and 5 Martin Place in Sydney.

Veena Sahajwalla

Veena Sahajwalla

Materials Engineer & Inventor

As Funding Director of UNSW’s Centre for Sustainable Materials Research and Technology (SMaRT@UNSW), Veena is reimagining the global supply chain by demonstrating the possibility of ‘mining’ our overburdened landfills to reuse elements like carbon, hydrogen, and metals embedded in our waste. Veena is renowned for her internationally commercialised EAF ‘green’ steelmaking process.

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