The Future of Plastic Waste

ANNA PLOSZAJSKI

Plastic Waste. Of all the world’s environmental issues, this seems to be the one we understand pretty well. I mean, the headlines make so much sense…

“The over abundance of plastics filling the oceans and landfills”

“bags, bottles, straws and plates”

“using about 6% of all extracted oil”

The documentaries are unforgettable.

“In some parts of the ocean, it’s estimated that there are now over 1 million pieces of plastic for every square mile”

And the solutions seem so simple.

“England will ban a range of single use plastic items”

“NO MORE PLASTIC STRAWS”

But what if we’re only hearing part of the story?

ALICIA CHRYSOSTOMOU

Plastic is associated with cheap rubbish nasty, and that has been the way for several decades now.

ANNA PLOSZAJSKI

What if the messages and replacement products that we’re being sold are obscuring the complex reality of how we should design, use and recycle plastic products?

ALICIA CHRYSOSTOMOU

I have a bag and it says on it ‘I am green, I am bio’

KAT KNAUER

I hate those bags.

ALICIA CHRYSOSTOMOU

I know, they’re awful, it’s so misleading.

ANNA PLOSZAJSKI

And could engineering give us some new ideas that hold stronger than a damp paper straw?

KAT KNAUER

There’s so many people in this world trying very hard to make recycling work, to get us to a circular economy.

ANNA PLOSZAJSKI

I’m Dr Anna Ploszajski, a materials scientist, engineer and storyteller and I’m fascinated by how we make, use and talk about the materials around us.

In this episode of Create The Future from the Queen Elizabeth Prize for Engineering we’re going to be picking through the mountain of media messaging about plastic waste, to try to clear away some of the misinformation and unearth the engineering solutions that could really change things.

I’ll be joined by two guest experts, Dr Alicia Chrysostomou, a professor of polymers who’s made it her mission to better inform the public on the reality of plastic waste. And Dr Kat Knauer, a chemical engineer who’s developing cutting edge technology to chemically process and repurpose plastic materials so they can be used again and again. So, let’s get into it.

I'll come to you first Kat, tell us who you are and what do you do?

KAT KNAUER

I'm Kat Knauer and I'm a polymer scientist by training and I'm a researcher at the National Renewable Energy Laboratory in Golden, Colorado. So we are a Department of Energy, US government lab. A lot of people are probably wondering why a department of energy lab works in plastics, but as part of that I am the Chief Technology Officer of the Bottle Consortium. And that stands for bio-optimized technologies to keep thermoplastics out of landfills & the environment. So we're developing technologies that both more efficiently recycle plastic waste today while concurrently developing materials for the future that are more intrinsically recyclable by design.

ANNA PLOSZAJSKI

That is so exciting. And we're gonna be getting into all of that with you today, which I can't wait to talk to you about. And Alicia, hello.

ALICIA CHRYSOSTOMOU

Hello, yes. My name's Alicia Chrisastormu and I have a background in polymer engineering. So I did my, absolutely everything actually, my undergraduate degree, master's and PhD all in the field of polymer engineering, science and technology. Went on to become an academic, I was a senior lecturer for many years. Recently I had a book published by Hero Press and it was called ‘Plastics: Just a Load of Rubbish?’. And there was a very important question mark at the end of ‘Plastics: Just a Load of Rubbish?’. Because I got so frustrated with all the misinformation out there surrounding plastics and it was just to set the record straight. So it just covers everything to do with plastics and looking at the recycling and why it is and why it isn't recycled and why the material actually sometimes is environmentally better than alternative materials.

ANNA PLOSZAJSKI

Exactly. So I mean, those are some of the viewpoints that we're going to be touching on today. And I think this is such a complex topic. So before we get into any of that stuff, let's get back to basics. We've been talking about polymers and plastics. I would like to ask you how you define those terms. What do you actually define as plastics? Alicia, I'll come to you first.

ALICIA CHRYSOSTOMOU

Well, I suppose this is part of the confusion because every time you look in the media, and it's something derogatory or something terrible has happened, it's a plastic. When there's any sort of new research done and this is the new wonder material and it's done fantastic things for humanity, it's a polymer.

ANNA PLOSZAJSKI

That’s so interesting.

ALICIA CHRYSOSTOMOU

It really is, honestly if you look at the words used in the media, it's incredible. It's these little trigger words that they use, but really and truly plastics just means something that can be moulded. If you go to you know, the absolute basic of the words, the polymer, you can have natural polymers, and it's just the way the building blocks of the material is put together, that it is many repeat units. So really and truly, I think in this day and age, polymer really is a more encapsulating term.

KAT KNAUER

I absolutely agree. You hit the nail right on the head that when you describe how when we do cutting edge research, it's always a polymer and if it's some kind of negative story, then it's a plastic. The terminology plastic in and of itself is a mechanical property. And that is what led to these, like you said, multiple re-processable reworkable materials which have plastic responses to mechanical deformation kind of being branded plastic. It's confusing the people and the society now as well. So I completely agree with you. It's all polymers.

ANNA PLOSZAJSKI

So, can we agree as the three of us, what terms are we going to use here? Are we going to use plastics or polymers?

ALICIA CHRYSOSTOMOU

Do you know something, I think probably to have everyone get on board with what we mean, there is probably no harm if we say plastics here and there, but sort of saying from the beginning, all right, we do mean polymers. But to engage, you know, because we're really trying to make sure that the public have a better understanding. So in order to get that psychology that plastics is sometimes it's as good as beneficial, it's not always bad. I personally, I don't know about yourself, Kat, but personally, I think probably there is no harm in using the term plastic as well in a more positive light.

KAT KNAUER

I completely agree. Because of the fact that we are trying to, like you said, Alicia, educate the public on these topics. Let's make it plastic and…

ANNA PLOSZAJSKI

Wonderful.

KAT KNAUER

We're all in agreement.

ANNA PLOSZAJSKI

Okay. But listeners, yeah, listeners, now you know what we're talking about. When we use polymers and plastics, you're in on the secret now. So we've been, we’ve been talking about the sort of public perception about plastics and how that differs from polymers. And I wanna get into a little bit of scene setting about how this public perception came about. So what is it about the story of plastics that has given them this bad for the environment reputation?

ALICIA CHRYSOSTOMOU

I think it's humans that's bad for the environment, quite frankly, it's not the plastics, it's the humans and their over-usage and their disposal, and there’s all sorts of things, but it's not really the materials. When plastics first came about, there was a need for replacing billiard ball materials because billiard balls were made from ivory. You needed three elephants to make a set of billiard balls because you could only get four or five quality balls per tusk. This was leading to you know a quick march to extinction of the elephants. Tortoiseshell glasses, combs, all sorts of little trinkets, little jewellery boxes etc was made from tortoiseshell. Stays for Victorian corsets were made from baleen, came from Wales. So you had all these creatures being used for their body parts, all hunted to near extinction. And this is where polymers came in. So this celluloid, this Parkesine, came in as your very first material. So at the very, very beginning, actually, plastics went a long way to save animals from extinction and almost certain near extinction, certainly for the elephants.

ANNA PLOSZAJSKI

Right. That's such an interesting part of the history that we don't often think of, which is very different from the kind of, well, it's part of the public consciousness near the end of the story of plastics. If we think of them as being around for almost a hundred years, the plastic waste issue, specifically about the end of their life, that has only become a bit more apparent in recent years. Kat, can you tell us a bit more about how the plastic waste vilification side of the story actually comes into it?

KAT KNAUER

Yeah. I think that is why we're kind of shifting over into this ‘well we need to go to only alternatives, glass, paper, metal’, because of the plastic waste that's becoming so visual with the rise of social media and the more just connected global network that we're in, we now see the ultimate consequences of the exorbitant waste that have entered our natural environment. I think of everything from an emissions and energy point of view because I'm department of energy lab. So if we look at the way plastics have reduced emissions from vehicles and aeroplanes. These things used to weigh 100 x times more. Our homes are more energy efficient. And that is something that's been imparted by plastic materials. But we've also been brainwashed into single use convenience. And it is ultimately this disposal problem that's led to the massive amount of waste. We lose something like 20% of all plastics produced per year through littering and through lack of proper waste management in many, many parts of our world. One of the best papers that really sparked this awareness in the academic community to a point of, ‘we need to do something about this’ is Jenna Jambeck's paper in 2015. That was with the first study I saw that truly quantified how much plastic is produced per year, how much is landfilled, how much is lost to the natural environment. And that's when we were so aware that the sheer amount of carbon, this like oil spill that's across the earth, because that's what it is, is something that needs to be addressed. And so then we had the actual numbers and that's when we were like, okay, now we know how bad this problem is.

ANNA PLOSZAJSKI

One thing that frustrates me about the discourse around plastic waste is that we focus our attention on wastage of just one subsection of materials, which is plastics. But we also throw away all of our other materials as well. We create so much waste in addition to plastic waste. From your point of view, is that attention on plastics justified? And if so, how does it fit into that bigger picture of all of the waste that we're producing?

ALICIA CHRYSOSTOMOU

I absolutely agree. It is all the waste and Kat is absolutely right when you said we're spilling oil everywhere. Again, looking at the numbers, when you look at how much oil actually goes into making plastics and rubber, it is only anything between 4% and 6% of the total oil and gas produced globally. So yeah absolutely we're spilling everywhere and we shouldn't. We are incinerating the vast majority of these fossil fuels. And this is something else that is never discussed, it's always wasting oil, fossil fuels using for this. Actually, it's a very efficient use of fossil fuels because you are preserving those fossil fuels. When you are incinerating for aviation fuel and for bunker oil for the ships and for heating oil and gasoline, you are burning it. There is no going back. You know, there's no recovery of it. At least with that 4 to 6% of the oil and gas that's used for manufacturing polymers you have created something tangible and it is something that you could then go back and tap into again and use as a future resource. But in terms of the waste, I go mud larking sometimes on the Thames, which is an absolutely fantastic hobby.

ANNA PLOSZAJSKI

For listeners that don't know, can you describe what mud larking is?

ALICIA CHRYSOSTOMOU

Yeah, absolutely. You buy permits from the port authority and you can go down and you can hunt for little bits and pieces that you find along the foreshore on certain areas along the River Thames. And you can get anything from Neolithic to Roman to Victorian, you know, to more modern. You can just find a terrific array of things. But what it absolutely shows you is how much was thrown away, back all the way through the various eras going back to Neolithic. There has always been a tradition of discarding your rubbish, your waste, into a moving body of water, whether it's a river or a sea. So there's always been this problem with people littering. It's the nature of plastics that makes it more visible. It's more buoyant if it is in the sea. It's not right that it's there, but it absolutely shouldn't be the only thing that we look at because there is so much more that is also polluting that can also cause issues.

ANNA PLOSZAJSKI

So I want to focus on one particular application of plastic and plastic waste. And that is, of course, packaging. That's something that I think is really up in the public's consciousness in terms of applications of plastic that we touch every day, that we encounter every day, that we have to make decisions about every day when we're standing in the supermarket. What are the other reasons that the public seems so sort of mono-focused on packaging, do you think?

KAT KNAUER

I mean, I think a big part of this is e-commerce that we saw so much of packaging increase in our regular lives, not just the grocery store. That's where we used to kind of conventionally see it most of the time. And then we started online shopping like crazy and now we're getting everything wrapped in a plastic envelope and then inside of that, there's those little air bubbles that pad it up so it doesn't get damaged and there's a regulation about it. And so I think we just became hyper focused on packaging. Also, because of drinking water not being accessible in so parts of our world, plastic bottles also became such a focus of environmentalists. Packaging just kind of shifted into, ‘this is the problem’.

ANNA PLOSZAJSKI

What's interesting to me is this interplay between the consumer, the media, and policy makers. The plastic water bottle is one that we, as you say, still have everywhere, you know, it's still a very kind of available type of plastic waste. But there are other examples that I saw policymakers step in very quickly, and in my view, a bit rashly, to ban certain types of plastic products in response to some of the media backlash that sort of started around the kind of 2015 ‘Blue Planet 2’ in the UK, sort of time when this really jumped into public consciousness. It's really hard for consumers to know what is the right thing because if the government are telling them one thing, the media is telling them something else, and they're trying to make decisions every day about what to buy or you know, what to avoid. What are the examples that, maybe an example product that was one of these alternatives, let's say, that actually may be slightly misguided? Alicia, did you find any in your book?

ALICIA CHRYSOSTOMOU

The one I really picked out was plastic straws, because you had a product that was perfectly good. Polypropylene straw extruded nothing else in it, just the material. It worked, it absolutely worked for its purpose. They were banned. You now have paper straws. You put them in your mouth, they stick to your lips. They leave a taste in your mouth. They squish up, they mush up, the kids chew them. They are not just paper though, in order to make them robust, they have coatings on them. So they have gum. So it could be a gum that will break up in water. It may be a more robust glue that is actually a plastic in order to make them rigid enough to do the job that the plastic did in the first place. But now you've got paper and plastic mixed together that absolutely cannot be recycled. Whereas the polypropylene straw could have been recycled if they changed the infrastructure or improved the infrastructure. So for me, that's my standout one.

ANNA PLOSZAJSKI

That's a really good example. Kat, I want to come to you and give a little bit of hope in amongst all of this confusion. There are people like you, wonderful people like you, who are hearing the concerns, seeing the problems and using engineering to try and address those. So talk to us about your research.

KAT KNAUER

So, you know, we all love to hear these alarmist headlines that have been coming out constantly, that recycling's broken, recycling's lying to you, recycling will never work, you name it. It’s so depressing to see because there's so many people in this world trying very hard to make recycling work, to get us to a circular economy, including myself. So what our research is here is we're trying to develop ways to harness these carbons back from plastics and keep them in reuse for infinite cycles. My joke earlier that they're basically an oil spill. It's oil that we can be getting back and we can stop relying on fossil fuels or agricultural resources to make these materials. And so everything we're doing is a lot of, can we break these materials down using combinations of chemistry and biology co-integrated into super efficient processes that are economically driven, that do have profit at the end of the year? And also we’re guided heavily by life cycle assessment so reducing environmental impact. If your recycling technology is more emission intensive than it was to take the oil out of the ground and make the plastic, that's not a solution. And so it's not just waste management we're also very driven by emission reduction but we're working really hard. And we're not just doing this to publish papers and get academic prestige. We're starting companies, we're deploying technologies. We started two companies out of Bottle in the last four years. One's textile recycling, one's a bioplastic company. We're trying to make tangible solutions. And I hope that gives everyone some hope that a lot of people are working really hard to solve this.

ANNA PLOSZAJSKI

Totally. So let's get a bit nerdy. I want to learn even more about these particular chemical solutions. So, you're working specifically on the process of chemical recycling. Can you tell us a bit more about how that works? You mentioned chemistry and biology, but what's actually involved?

KAT KNAUER

Basically two technologies have been around for a really long time. One's called pyrolysis and one's called gasification. Pyrolysis basically uses thermal heat and energy to break the bonds in plastics and convert it into what you can imagine visually looks like an oil, and that can go get refined and reprocessed. So that's pyrolysis. And gasification is when you basically also use very high temperatures to take plastic and gasify it into syngas. So whenever we say chemical recycling, everyone thinks that's what we're working on and that's not what we're working on.

ANNA PLOSZAJSKI

Okay.

KAT KNAUER

These technologies can have a place in certain aspects of our society. Really, really contaminated medical waste, things like that could be applicable there, but they are very energy and emission intensive. And so what our task is, what we've been designed to do is, okay, can we do this in a very selective, low energy way? And can we integrate systems with biology? And so I'll just give one example. We call it OxFun, oxidative funnelling. And it's when in one step we took mixtures of Styrofoam, water bottles and milk jugs. We can oxidise those plastics under a pretty mild reaction, very low energy and emissions. And what it does is it creates a soup of these oxygenated products, these small molecules that maybe have value in them, but it's not really cost effective to try to take that soup and isolate every single molecule. So what we did instead is we engineered a bacteria that will take the oxygens and carbon and use it as a food source to basically digest and then through a metabolic pathway that we engineered, we made a new bio plastic from it called polyhydroxyalkanoate or PHAs. And so while this is very early stage research, this isn't gonna be commercialised next year, but we're trying to show the world that we don't have to silo biology and chemistry. We can use the force of those two together. That's just giving you guys an example of what I mean. Chemistry, biology together.

ANNA PLOSZAJSKI

That's so awesome. And a really good answer to this problem that we have, which is that a lot of our plastic waste streams are completely mixed up of loads and loads and loads of different types of plastic. That that's one of the big barriers to recycling, right? But you're saying that your process would be able to let that sorting job be done by the bacteria.

KAT KNAUER

Yes, exactly. And that's what we're trying to, we're trying to make as easy as possible the upstream part.

ANNA PLOSZAJSKI

Alicia, are there any other examples of how engineering is helping to bring about that future more quickly?

ALICIA CHRYSOSTOMOU

What I would say is that education is a big thing, so not engineering so much as education. And it's not just for the public, but it's the people that look after our waste, so the councils that tell us which bin to put things in and even the companies that are putting stuff out there. So, for instance, I have a bag and it says on it, I am green, I am bio. But then you look at the small print and it says LTP, low-density polyethylene.

KAT KNAUER

I hate those bags.

ALICIA CHRYSOSTOMOU

I know they're awful. It's so misleading because it's green ink all over it. Yeah. You got the same in America, right? But honestly, it's so misleading because you think it's bio, it's a biomaterial. I can put it in the compost bin or I can put it with the food recycle, whatever, because it will be dealt with and it cannot, it is a plastic. So it's this clarity, a greater clarity. What have we got and how do we recycle it? And never mind what it used to be or what it was made from, what am I going to do with it now? And stop putting green stickers on things and you're confusing everything.

ANNA PLOSZAJSKI

Yeah, absolutely. I'm gonna give each of you a magic wand at this point. I'll come to you first Kat, if you could create the perfect plastic product. Okay, let's say the perfect plastic bag, because we've just been talking about those. What would your perfect plastic bag look like?

KAT KNAUER

Okay. Yeah. Magic wand, perfect. I'm going to go with three kind of key attributes. One, mono material design. So instead of multi-material, which cannot be recycled, can we use chemistry and engineering principles to redesign them to be one type of material? So it can be more intrinsically recyclable. Two, I also see a version and vision of the future that we do transition away from fossil fuels and we do transition to utilisation of biogenic carbon. So I want to see use of biogenic carbon in materials. And I want to see it labelled correctly as well. So is this recyclable? Can it go in my bin? We consider ourselves expert, and I will still look at a material and sit there in agony and be like, ‘Where does it go?’ And so I want clear labelling, clear education. So that's my bag, those three things, monomaterial, biogenic carbon, and clearly labelled for what to do with it when you're done with it.

ANNA PLOSZAJSKI

Love that. Alicia, do you agree? Would you add anything from your point of view?

ALICIA CHRYSOSTOMOU

It's very hard to top that. I mean, 100%, absolutely. There was research done looking at bags specifically and looking at how many times you would need to recycle them in order to make them as good as the LDP, those anti-polyethylene, to the normal vest bag that we used to get in the supermarket day in, day out, the amount of times you need to use a paper bag, something like, I think it was forty three times for a paper bag, just to make it as efficient in all respects as one plastic bag. Bags for life, Kat, they brought in in the UK. A little bit more robust, you're using more polymer. You need to use those forty odd times before they're as good as one single vest bag. Things like then you go to cotton, organic cotton, because of the water, the energy, the pesticides, everything else that uses, twenty thousand times it needs to be used in order to be as good as one little plastic vest bag. But again, the public don't know that, the public think, you know, you see everywhere now, cotton bags. You have to use those hundreds of times, even if it's not organic, you still have to go something like four hundred and fifty times to reuse a single cotton bag.

ANNA PLOSZAJSKI

Well, then, so hopefully Kat's idealised bag would be a future that we can look forward to, but I'm interested in why we don't have that now. What are the main obstacles that are stopping us from creating these products? Because they should be quite simple on the face of it. You know, we've sent people to the moon. Can't we create a good enough plastic bag? What's going on? Kat, what are the main difficulties?

KAT KNAUER

I mean, I think a big limitation there was there really wasn't a lot of resources and funding for this kind of work for a long time. As Alicia mentioned, the bag we had worked great. And there's some ingenious work that did go behind that. I didn’t want to undermine that. I mean, people who have won Nobel Prize for catalyst design, for polyol synthesis, I mean it was a true really beautiful chemistry that went into making something like an LDPE film. But the reason we haven't redesigned that material for so long is because it worked really well. We thought it was recyclable. We didn't anticipate all these future challenges of, well film can't really go into the waste collection facility. And then also the shift towards biogenic and more bio-based materials is happening more but it's still very slow. We have a very efficient system with fossil fuels, and it's going to be growing pains to shift away from that. And those growing pains are going to show costs economically and in emissions. They're going to seem more emission intensive because they haven't had one hundred years to optimise. And then furthermore, we also got kind of pushed backwards. Like you mentioned, Alicia, with the bags, we switched over to reusable bags, which I do still believe have their place 100%. But because of that, now we're not really thinking about, should we re-engineer a bag again? But I think that's also why instead of thinking about something like the bag or the straw, we're really going to go to the heart of it and we're going to go to true food packaging, the multilayer film packaging. That's where I think this redesign beautiful vision that we have, that's where it's going to go.

ANNA PLOSZAJSKI

Alicia, are there any main barriers that you've seen maybe on the kind of social side, either the public or maybe talking to policymakers? What are the barriers to the perfect plastic products, in terms of the bigger picture?

ALICIA CHRYSOSTOMOU

Ah. Maybe it all goes back to, and I hate to say, ‘oh, the media and the way it's been portrayed’. But it goes back to the very beginning of this conversation when we said, I think it was yourself, said about Blue Planet, fantastic, absolutely seminal. It was a fantastic production. And it made a lot of people aware of a lot of things including the issue, and we'll say the issue was plastics. On top of that, certainly in the UK, there were programme after programme that just jumped in and said ‘plastics bad’. The War On Plastics was one other programme. The language that's used around the material is just everything points, this is a problematic material. We had years of saying plastics, isn't this a wonderful material? We suddenly switched to this mindset of plastics are the bane of life and you know they're causing all these issues to everything, societal included. I think there needs to be some sort of a rejig maybe we need some seminal programme, get David Attenborough in to show look what we can manage, look what we've achieved with the thing, look at how we've advanced to me for goodness sakes we've gone to the moon in this last hundred years. The things you can do now that you absolutely could not do a hundred years ago. A lot of it is with thanks to plastics being on the planet.

ANNA PLOSZAJSKI

We've come to the end of our conversation now. And I've learnt so much from each of you. If I could push you each to give me a very short soundbite, if that's possible, about something that you've learnt, something that you've learnt new from each other.

ALICIA CHRYSOSTOMOU

Well, I think what I learnt from Kat is remarkable. I'd heard of this work being done before, but I honestly think that could be an absolute game changer. We have plastics at the moment that are difficult to recycle. It is a resource. I have said before, and I don't think I'm the only person to have said it, landfill, have a dedicated landfill for those problem plastics until a solution can come along, and then mine them as a resource.

KAT KNAUER

Yeah, and I think what I learnt today from Alicia that is truly shocking is that, I know this is just like one example, but three elephants, it took three elephants to make a total set of billiard balls! That is horrifying. Thank you for giving me another statistic to use on team plastic. Because I do think it's been demonised so heavily. It's a problem. We know it is but demonising and vilifying every single piece of plastic is not going to be the solution. So thank you for that perspective.

ANNA PLOSZAJSKI

What I found interesting in being part of this discussion has been learning something new, you know, I had in my mind a strong narrative for what I thought the story of plastics was, and you've both added so much more to that. It's given me a lot of hope actually that we are incorporating not just the technical problems, but also the barriers that we have in society to making this mindset shift happen. And I'm looking forward to seeing you both on TV to deliver that message instead of David Attenborough.

KAT KNAUER

Yeah, I can't wait, can't wait.

ANNA PLOSZAJSKI

What I loved about this conversation is that it shows us how engineering is so much more than just new inventions, especially when it comes to the environment. Of course, we do desperately need people like Kat who are dedicating their lives to researching the issue of plastic waste and developing new technology that could slot into existing infrastructures. But, the point is the solutions won’t come from only one place. Public understanding, policy making, media messaging - this is all the stuff around engineering that gives it its impact and as Alicia said, if the public aren’t properly informed then none of it’s going to get very far.

You’ve been listening to Create The Future, a podcast from the Queen Elizabeth Prize for Engineering and Peanut & Crumb. This episode was presented by me, Anna Ploszajski and was produced by Jude Shapiro. It featured Dr Alicia Chrysostomou and Dr Kat Knauer.

To find out more follow QEPrize on Twitter, Instagram and Facebook and thanks for listening, we’ll see you next time.