04/30/2021

The Future Of Plastics

17:22 minutes

plastic water bottles and other debris floating in the ocean
Credit: Shutterstock

Plastics do a lot of good. They’re sturdy, they’re clean, and the COVID-19 pandemic has really highlighted their benefits, with personal protective equipment like disposable gloves and masks.

But its durability is also its biggest problem. We’ve all seen photos of piles of plastic trash washed up on beaches, and animals surrounded by plastic bags and straws. Those materials will take decades, if not centuries, to break down. Even as it breaks apart, it can become millions of microplastic particles that cause their own problems.

So how do we tackle one of the biggest environmental crises of our time? Scientists are working on both ends of the plastic life cycle to come up with solutions. Breaking down the plastic that’s already out there, and coming up with alternative materials that could be better for the planet.

Guest host John Dankosky interviews two scientists doing great work on this topic: Dr. Francesca Kerton, professor of chemistry at Memorial University of Newfoundland in St. John’s, Canada, works on alternative polymers that could replace some plastics. Her latest research is focused on a polymer made from fishery waste. She’s joined by  Dr. Gregg Beckham, senior research fellow at the National Renewable Energy Laboratory in Golden, Colorado, who works on enzymes that can break down plastics to its smaller building blocks for easier recycling.


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Segment Guests

Francesca Kerton

Francesca Kerton is a professor of chemistry at the Memorial University of Newfoundland in St. John’s, Canada.

Gregg Beckham

Gregg Beckham is a senior research fellow at the National Renewable Energy Laboratory in Golden, Colorado.

Segment Transcript

JOHN DANKOSKY: This is Science Friday. I’m John Dankosky, and we’re continuing our special hour about plastics. We know that plastics can do a lot of good. They’re sturdy. They’re clean. And the pandemic has really put their benefits to the forefront with personal protective equipment like disposable gloves and masks.

But its sturdiness is also its biggest problem. We’ve seen all the photos– piles of plastic trash washed up on beaches, sea creatures swimming along plastic bags and straws. That plastic is going to take decades or even centuries to break down. And as we’ve heard, as it breaks apart, it can become millions of tiny microplastic particles that cause their own problems.

So how do we tackle one of the biggest environmental crises of our time? Scientists are working on both ends of the plastic life cycle to help us tackle this issue, breaking down the plastic that’s already out there and coming up with alternative materials that could be better for our planet. Joining me today are two scientists doing great work on this topic. Dr. Francesca Kerton is professor of chemistry at Memorial University of Newfoundland in St. John’s in Canada. Welcome to Science Friday.

FRANCESCA KERTON: Hello.

JOHN DANKOSKY: And Dr. Gregg Beckham is senior research fellow at the National Renewable Energy Laboratory in Golden, Colorado. Welcome to the program. Thanks for being here.

GREGG BECKHAM: Thank you, John.

JOHN DANKOSKY: So Francesca, I’d like to start with you and get an idea of the work you do. It’s my understanding that you’re part of a team that made a plastic alternative from something that I wouldn’t have thought of– fishery waste. How did this idea start?

FRANCESCA KERTON: So in Newfoundland, we’re surrounded by the oceans. And I got involved in a conversation with the Newfoundland Agriculture Industry Association, and they told me that they were having a problem with the amount of waste being produced at fish processing plants, so particularly salmon. And so we all know that salmon’s good in our diets because it has healthy oils in it. And so the waste material that’s produced, which is about 50% of the caught fish, has a lot of oil in it, too.

So I knew about research in the US and elsewhere where they were using vegetable oils to produce plastics, so soybean oil and things like that. So I thought, well, the structures of these oils are fairly similar. Could we use this waste material to produce a new plastic, and then would that plastic be more amenable to decompose or biodegrade in an ocean environment because that’s where the fish oil came from originally?

So we came up with a method for isolating the fish oil that– I always make this analogy that it’s like making a fish smoothie. So you take the waste fish, you blend it up, and then you let the oil settle out on the top. And then we take that oil, and in three easy steps, we can get to a plastic.

JOHN DANKOSKY: The first question that most people listening to this will probably ask is, does it stink? Like, does it smell like fish?

FRANCESCA KERTON: No, it doesn’t smell like fish. So at first, the oil that we get, it has a slightly fishy odor. So if anybody takes cod liver oil supplements or any other nutritional supplements that have a fishy base, it has that slightly fishy smell. But as soon as we get through these steps, the smell goes away, and the plastic does not stink.

JOHN DANKOSKY: What type of plastics could this possibly replace?

FRANCESCA KERTON: So the material we made is known as a non-isocyanate polyurethane. And these have got applications in things like clothing and soles of shoes, but also materials such as– you can foam them and make them into the seats in cars and all sorts of things. We’re still studying the exact properties of our material at the moment. Some of our research has been slowed down a little bit by COVID.

And so we can stretch this material so it’s quite a little bit like saran wrap, the first materials we’ve made. And so it would be interesting if we could kind of go kind of full circle where we’re using a byproduct of a food industry– could we use it for packaging of food, or even within the warehouses for wrapping up materials there?

JOHN DANKOSKY: Yeah, that kind of saran wrap to wrap up fish is one of the biggest uses of plastics in our food stream. And that would be really interesting. Do you know yet how long it takes to break down?

FRANCESCA KERTON: So we’ve done some studies using enzymes, which are biological catalysts. So the ones we’re using are called lipases, and they’re traditionally used to break down fats. And so where our oil is a fat, that’s why they’ve been good for doing this digestion.

And in our studies, we’ve also seen molds and bacteria growing on the surface of our fish plastic. And we’ve done gene sequencing on them, and they are bacteria and fungi that are commonly present in fresh water and in soils. And so we’re kind of looking into this more. And the short answer is we don’t know exactly how long in the open environment it will take, but I think they would definitely decompose more quickly than things like polypropylene and PET, just because of how they’re made and our initial studies.

JOHN DANKOSKY: Well, since you’re talking about enzymes, let’s turn to Gregg and the work that you’re doing, which is really about breaking down plastics with enzymes. Tell us about your work.

GREGG BECKHAM: So in 2016, a group from Japan reported a very exciting finding. They isolated a single bacterium from the soil outside of a Japanese bottle recycling plant where they were recycling polyethylene terephthalate, or PET. This is a plastic commonly found, of course, in single-use beverage bottles, but also in carpet as well as in clothing, and so it’s a very abundant material that, as Francesca was mentioning, will last a very long time when it goes out into the environment.

And in collaboration with the University of Portsmouth, our group at NREL worked on essentially trying to solve the structure of the two enzymes that this bacterium was identified to secrete to break down PET in the soil. And our goal was to understand– you know, PET’s only been around for about half a century or so in large circulation, and how is nature essentially adapting to the presence of these synthetic polymers out in the biosphere? And while our initial goal here was really focused on understanding that sort of evolution and how nature was adapting to these synthetic plastics, what that got us to thinking about was, can we use enzymes in a recycling process to be able to break down, say, PET plastic into its building blocks? And then we could either use those to go back into PET applications, or we could do further chemistries or biological transformations on those to maybe even make something of higher value towards this idea of upcycling.

And moreover, we’ve also looked at, what would a process like this look like at very large scale? So what would the economics look like relative to today’s mechanical recycling infrastructure? What would the sustainability look like relative to virgin PET manufacturing? And in both cases, this is predicted to be a cost-competitive potential process, but it’s also predicted to be much more environmentally friendly from an energy and a greenhouse gas emissions perspective than virgin PET manufacturing.

JOHN DANKOSKY: Are you looking at breaking down plastics that aren’t PET?

GREGG BECKHAM: That’s a great question, John. So as part of the US Department of Energy-funded BOTTLE Consortium, which I lead, we are definitely looking at across the spectrum of other types of plastics as well, including, as Francesca was mentioning, polyethylene, polypropylene, even things like PVC, which are typically deemed to be, essentially, not recyclable hardly at all. So absolutely. We’re looking across the spectrum and across sort of the global consumption of plastics towards things beyond PET.

JOHN DANKOSKY: Francesca, Gregg talked about scalability for enzymes. And this is a really important piece of this. What about your fishery waste polymer? Do you see this as being mass deployed in some industry?

FRANCESCA KERTON: I don’t think it will ever be mass deployed, just because the economics of scale are already in place for these petroleum-derived materials. But what we do know is that you can produce enough fish oil worldwide from waste that can be competitive with linseed oil, castor oil, and other plant-derived oils that are produced on an industrial scale for other applications, such as in surfactants and things like that. But yeah, one of the things we need to do is try and identify kind of higher value uses for these bio-derived plastics to actually make them worthwhile and economically competitive.

GREGG BECKHAM: And if I can build onto what Francesca was mentioning, I think that I share the excitement about waste-based sort of new plastics. And towards this concept of recyclable-by-design plastics, I think the onus is on us as a research community and in industrial communities to essentially work towards both dealing with today’s plastics, as we just discussed, but also, in the vein that Francesca is working on and we are also working towards, can we redesign tomorrow’s plastics to be inherently more recyclable than they are today? Can we onboard bio-based inputs and waste-based inputs instead of the building blocks that we derive from fossil fuels today?

And I think when we start over with a sort of a clean slate with, say, fish oil, for example, as a feedstock, or other types of waste or bio-based sources as feedstocks– non-food-based bio-based sources, I should say, as feedstocks– that changes the landscape in terms of the materials design space such that we can both think about performance, which of course we all want and need in plastics and materials that we use every day as consumers, but also in terms of the recyclability at the end of its functional life, whether that be use in packaging for minutes to hours or use as a wind turbine or a car part, which might be in use for decades at a time.

JOHN DANKOSKY: But I’m wondering, Gregg, if you could build on that, though. It seems as though one of the fallacies that we have in our mind about recycling currently is that if I take this plastic bottle and I put it in a blue bin outside my house, it goes and gets made into something wonderful somewhere else. And the fact is, if the economics of that something wonderful aren’t there, then it’s probably not going to be made in anything else. It’s going to be burned or put in a landfill. So can you talk a bit more about the economic imperative of making something that you can actually use and sustain for many cycles, not just maybe one more cycle?

GREGG BECKHAM: That’s a great question, John. So the sort of canonical example that many folks always use, myself included, is really the single-use beverage bottle, which is mostly PET. Has other plastics in it as well, but mostly PET. When we put that into the blue recycling bin, that sometimes will be recycled, and often will still go to the landfill.

But when it is recovered and recycled and sent to a materials recovery facility, it will be thermally processed after being cleaned and et cetera. It will then go into lower-value PET applications like clothing or carpet or other types of fibers. So it’s essentially a down-cycling from an inherent economic value of that PET bottle to something lower in value that will ultimately, after its second life, still end up in a landfill, or worse, in the environment.

So again, I think the onus is on us to work towards developing new technologies that could incentivize reclamation of not only that PET bottle, but other types of plastics, both that are mechanically recyclable today, but perhaps that are not– where there is not a large economic incentive to do so. And then beyond that, to Francesca’s point earlier, for example, there are lots of plastics out there that we take for granted that cannot be recycled at all today, like foams in a seat cushion. That cannot be recycled easily today through the current mechanical recycling infrastructure. And so I think there’s opportunities both to develop new technologies that will incentivize today’s plastics that are recyclable, but perhaps are not at a sufficient scale, as well as those that are not recyclable at all.

JOHN DANKOSKY: I’m John Dankosky, and this is Science Friday from WNYC Studios. As we continue our conversation about plastics, Francesca, I want to ask you about this idea of biodegradable plastic packaging. A lot of us are now seeing that come into the food stream more regularly. You know, you get the biodegradable plastic fork, and you feel like, OK, well this is something that if I throw in the garbage is going to break down. But there’s a whole lot of problems with that in that if you don’t dispose of it properly, it probably is not going to break down. Can you talk us through this problem a little bit, the limitations of biodegradable packaging or products?

FRANCESCA KERTON: Most of the materials that we see for biodegradable packaging and so on, often they’re made from either starch-based plastics or polylactic acid. And most of them, if they’re going to degrade, they need to be in kind of industrial composting facilities.

Many of you may have, I don’t know, disposable coffee machine things with the little capsules. And some of them are labeled degradable now, and I know lots of my friends have been out and got them. And then they put them into their compost heap, and then they dig them up a year later and they’re still there. And so they really aren’t made for home composting.

And most cities around the world, they often don’t have the facilities to do industrial, large-scale composting. So where I am, it’s only a city of about 300,000 people. They don’t have municipal composting. They tell us to just compost at home. And so all of these biodegradable packaging, they just end up in a regular landfill. And that’s an anaerobic environment, and they’re not going to be degrading anytime soon.

So there’s no quick solution. There’s both the materials design aspect, but there’s also changing the way we live and how governments on a small-scale, particularly municipal regional governments, handle their waste and start investing in industrial composting.

JOHN DANKOSKY: With just the last few minutes that we have, I guess I should probably ask you both about that larger scale question. And Francesca, I’ll start with you. You’re both working on ways to make this problem better, new types of packaging that might degrade better or made from more sustainable products, enzymes that can break down the plastics in our environment. But if you had a magic wand, Francesca, I mean, how would you make this entire process just a little bit better? Could we think about this differently?

FRANCESCA KERTON: I think we all– everybody out there needs to think about the bigger picture of both, there’s a beginning and an end of life. And so if we’re more conscious as consumers about what we buy and are willing to spend a little bit more on something that maybe had a renewable start to life and didn’t come from petrochemicals, that would go a long way. And also just consuming less so we have less waste to dispose of.

JOHN DANKOSKY: Greg, how about you? How do you think about this in the big picture?

GREGG BECKHAM: Right. I think in the grand scheme of things, I’d break this problem into two pieces. One is today’s plastics, the things that we make now that are inherently challenging or impossible to recycle. I think that it is imperative that we develop technologies and the associated infrastructure as well, which certainly will take industry, government– at all sort of geographical levels all the way up to the planetary scale– to be able to work towards technology and infrastructure that can handle today’s plastics.

I think on the other sort of pillar of this challenge is that we have to think about sort of starting over. We need, in the next decades, to make plastics that are inherently more sustainable from an environmental perspective, that are economically viable relative to the infrastructure that we have today from petroleum and fossil-based carbon that go into plastics today. We need to do the same from a bio-based and waste-based feedstocks perspective, while at the same time thinking about, as Francesca mentioned, the infrastructure for collection and dealing with these things.

That involves so many stakeholders across multiple parts of the supply and value chain. That’s inherently a massively challenging problem. But towards your question about a magic wand, I think the infrastructure and the technology need to be developed hand in hand across all of those stakeholders.

JOHN DANKOSKY: Dr. Gregg Beckham is senior research fellow at the National Renewable Energy Laboratory in Golden, Colorado. And Doctor Francesca Kerton is professor of chemistry at Memorial University of Newfoundland in St. John’s in Canada. I want to thank you both for your time today. I really appreciate it.

GREGG BECKHAM: Thank you, John.

FRANCESCA KERTON: Thank you, John.

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John Dankosky is a contributing editor with Science Friday, and occasional guest host. He also works with public radio collaboratives, and hosts “Steady Habits”—a podcast of the digital news service, The Connecticut Mirror.

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