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The merchandise many people buy regularly — the water bottles, garments and, maybe particularly within the period of COVID, take-out containers from our native eating places — are sometimes plastic, disposable and certain to survive us for generations. However the huge quantity of plastic waste that people depart behind is a logistical and ecological nightmare, and consultants say potential options have to be approached from a number of angles, each for the planet’s sake and for our personal.
Chemical engineer Paul Dauenhauer of the College of Minnesota has devoted his profession to revolutionizing the supplies we depend on most. He’s labored to derive essential “chemical building blocks” from renewable sources that can be utilized to fabricate present merchandise, in addition to create completely new options.
Not like supplies like fallen leaves or animal waste, which decompose simply with assist from microbes, the plastics we use right this moment can’t break down as nicely. They usually pose one other environmental risk due to the way in which fossil fuels, whose derivatives are used to create many shopper merchandise, together with plastics, are extracted from the earth.
Paul Dauenhauer is a chemical engineer and a 2020 MacArthur fellow. Picture courtesy of Paul Dauenhauer
Dauenhauer, who was named a 2020 MacArthur fellow, has used biomass — like wooden and crops — to engineer renewable chemicals which might be important to the manufacturing of widely-used supplies from plastics to rubber-based merchandise. Isoprene, for instance, is a “monomer” chemical that may be strung collectively to create polymers just like the substance used to make automobile tires. Dauenhauer has derived isoprene from biomass that’s thought-about a “drop-in substitute” as a result of it’s an identical to at least one that will also be derived from fossil fuels, and presents the very same efficiency.
Swapping in these extra sustainable options might help scale back our reliance on oil and gasoline, the extraction of which is a significant supply of air pollution with a hefty environmental affect.
However this work doesn’t cease with replacements. Dauenhauer and his colleagues are additionally invested in figuring out how you can engineer supplies in order that they’ll biodegrade extra shortly, be damaged down and recycled a number of instances or have extra handy properties than those we use right this moment.
“There’s a chance right here to not solely remedy environmental issues, however to create new, higher merchandise,” he stated.
A major problem is making these options each as helpful and as cost-effective because the fossil fuel-based supplies they search to exchange. That’s essential, Dauenhauer emphasised, with a view to seize the curiosity of each customers and the businesses chargeable for manufacturing and promoting our most-used merchandise.
The one concepts for renewable supplies “which might be actually going to have important affect are those” which might be value aggressive, Dauenhauer stated. That marks the distinction between know-how that would have a significant affect on the world versus one thing that’s “extra of only a scientific venture,” he added.
Dauenhauer spoke to the PBS NewsHour in regards to the main challenges we face in terms of absolutely pivoting away from fossil fuels, and the way he and his colleagues are working to engineer sustainable options that profit customers, producers and our planet.
This interview has been condensed and edited for readability.
You’ve characterised our unsustainable reliance on fossil fuels as “a race in opposition to time.” Are you able to describe what we’re up in opposition to right here by way of environmental affect?
The idea for the fashionable financial system, numerous it’s vitality and supplies. And people come from fossil fuels like petroleum and pure gasoline. Take into consideration the electrical energy that we use day-after-day, but additionally fuels in our automobile and supplies like plastic for clothes, vehicles, meals packaging, metals, medical provides. The issue is that they’re all contributing to environmental issues. And that might be local weather change, in fact, with CO2 emissions and methane emissions, but additionally plastic waste, which will get into the oceans, the rivers, the soil and our ingesting water. And so all of those are an enormous downside that accumulate over time. And we’d like new applied sciences that may deal with this, primarily earlier than they accumulate to the purpose the place they’re disastrous.
READ MORE: The Plastics Problem
The factor with fossil fuels is there’s an infinite provide. The issue will not be that we’re going to expire of fossil fuels, it’s that we’re going to create an excessive amount of of an environmental downside lengthy earlier than we might run out of fossil fuels. And so we have to really discover a technique to transition and depart fossil fuels within the floor, which is tough as a result of the economics of fossil fuels are so low-cost that it’s laborious to say, “We’re going to modify to one thing else.”
How does the carbon chain work now, and the way is it being reimagined?
Society has the identical strategy for every thing, whether or not it’s vitality or supplies. We take one thing from one place, we use it after which we throw it away someplace else. For fuels and vitality, we take it out of the bottom, we use it and the waste goes into the ambiance. For plastic, it comes out of the bottom, we use it and it goes right into a landfill or it’d go into the atmosphere.
The concept of a round financial system, although, is that we take carbon from the identical place we put it on the finish of its life. So for recycling plastics, which means we lure it — possibly in your recycling bin — however that has sufficient worth that we are able to reuse it. And so it simply retains stepping into a circle, and that carbon by no means goes anyplace.
Biomass matches into the closed cycle as a result of all of the carbon in it comes from the ambiance. Let’s say you make a biofuel, for instance. That carbon goes into the ambiance, however then the subsequent yr, it pulls simply as a lot carbon dioxide again into the bottom — into the plant materials itself. So it’s a net-zero emitter in that closed cycle.
Folks speak about pulling CO2 out of the air after which changing it into various things. Primarily, that’s what a plant does. It’s actually good at pulling CO2 out of the air by photosynthesis and capturing it — it’s a bit of CO2-capturing organic system. We don’t must invent that, nature already invented it. We simply have to determine what to do with it as soon as it’s in strong, plant-like kind.
What are a number of the principal boundaries in terms of transitioning away from fossil fuels?
I feel scaling up renewable, sustainable know-how affordably is the No. 1 problem. I imply, the advantages of electrical energy and energy and supplies are simply too nice, proper? They provide an enormously prime quality of life. No one needs to return to an age the place we don’t have entry to those issues, nor ought to we. They’ve an enormous profit for humanity. However to exchange them with one thing sustainable, we now have to do this in a approach that doesn’t change the associated fee dramatically or and even in any respect. And that’s actually the problem.
There are simply hundreds of concepts on the market for renewable supplies and sustainable electrical energy. However the one ones which might be actually going to have a major affect are those that may be engineered in a approach that they’re value aggressive. We use that because the benchmark for [answering questions like] Is that this know-how really going to have affect or is it extra of only a scientific venture?
What’s catalysis, and why is it so necessary to your analysis?
Catalysis is a know-how that allows you to flip one molecule into one other. It’s a really previous area, over 100 years previous. And we use issues like metals and metallic oxides and different strong particles — often nanoparticles — that enable the molecules to stay to a floor after which convert. And we design the floor such that the molecules convert the way in which we wish. So it matches into this concept of the bio financial system and the round financial system by discovering the chemistries and course of know-how that allow us do that most effectively.
So I begin with a plant, and about two-thirds of crops are literally sugars. So cellulose and hemicellulose are two of the largest parts of crops, lignin being the third one. However I can pull that out and make sugars out of it. And as soon as I’ve it as a sugar, I can put it in water and it dissolves. And so from there, I can do the chemistry utilizing our catalysts. And as soon as I make a molecule from the sugar, that might be used to make a fabric that’s referred to as a monomer.
Now, these monomers that I make, a polymer researcher will take these and hyperlink them collectively like beads on a series — like a pearl necklace, conceptually. After which as soon as he will get that massive molecule, that turns into the strong polymer. And that’s the fabric that folks use. So I work on the a part of making the monomer. And for a few of these supplies, as soon as we now have the monomer, we all know how you can make present supplies. For brand new monomers and new polymers, I associate with folks that do polymer chemistry and so they design the brand new supplies from the chemical substances I make.
Does the strategy of engineering drop-in replacements versus creating completely new supplies have extra benefit than the opposite?
It’s going to be a mixture of each. A few of the key polymers and plastics we use proper now, [two big ones being] polyethylene and polypropylene, are actually, actually low cost to get, and so they have excellent properties for what we use them for. There’s no approach in 100 years we’re not going to be utilizing these supplies. So for that software, we have to discover a approach to make use of it on the finish of its life and hold it out of the atmosphere.
For different functions, like possibly for clothes, we are able to discover new polymers. These are locations the place designing the molecules may make higher properties that possibly make the material softer or extra comfy than typical polyester. So I feel it’s gonna be a mixture of each. Nobody answer goes to work for every thing.
For those who have a look at something as a renewable recycling emblem No. 1, that’s P.E.T. plastic, that’s a polyester. And we use that each one kinds of locations for clothes, for soda bottles, for automobile components — it has actually nice properties. And so we are able to make that renewably, however it’ll nonetheless have the identical problems with what we do with it on the finish of its life. What we’d like is not only the flexibility to make new supplies, but additionally one thing to do with them after we’re executed with them. Can we recycle them in a approach that retains their properties simply pretty much as good, even when we’ve used them 50 instances or 100 instances or a 1,000 instances?
I’m from Minnesota, and so the one factor I care about in winter is, do the [plastics we use] get brittle in winter? There is a chance to make higher supplies which have higher properties and that’s one among them, that they don’t crack or break in the course of the winter, however they’re additionally recyclable or biodegradable or each.
Isoprene is a standard compound used within the manufacturing rubber that’s usually derived from fossil fuels, however you’ve been in a position to derive it from biomass. Is that isoprene an identical to the sort that’s constituted of fossil fuels?
Isoprene is a drop-in substitute. So you might purchase isoprene that’s constituted of fossil fuels or you might purchase isoprene that’s constituted of a renewable course of and also you wouldn’t know the distinction except any individual advised you. It’s a really particular molecule. In order that, in idea, would allow you to make the very same product you get proper now. You could possibly purchase a automobile tire constituted of renewable isoprene or fossil-derived isoprene, and it might be the identical tire.
So even when chemical replacements like isoprene are sustainably derived, can they nonetheless create the identical environmental points because the chemical substances they’re changing?
Making one thing renewably derived doesn’t remedy all the issues if there are different issues with the product. Like automobile tires, what do you do with a automobile tire on the finish of its life? For those who supply the very same chemical substances renewably, it solely solves a part of the issue, which is the sourcing. It doesn’t remedy the end-of-life downside. If some chemical substances have environmental issues, sourcing them renewably — if it’s the very same chemical — will nonetheless have the identical downside. So there are circumstances the place you want to have a brand new polymer completely. And there are circumstances the place that’s in all probability not going to be possible and we have to discover one other answer, like automobile tires. We have to discover an end-of-life know-how for that as a result of the present efficiency is mainly a security subject. You don’t wish to change the efficiency of the automobile tire.
Is it doable to engineer merchandise that use chemical substances derived from biomass in a approach that would make them extra sustainable?
Let’s say we make the identical molecules from biomass that we use proper now. You could possibly nonetheless restructure the polymers in a barely totally different approach or add in different parts that assist them break aside. I’m a part of the Middle for Sustainable Polymers the place I work on the feedstock aspect. However different individuals work on redesigning the polymers in a approach that makes them possibly extra recyclable, or extra biodegradable, or each, utilizing the present supplies we now have proper now. So is it doable to make a automobile tire that might be simpler to make use of on the finish of life with out altering its efficiency? May you make meals packaging hold its actually good barrier properties that hold your meals contemporary but additionally make it biodegradable, and never a major distinction in order that the patron doesn’t doesn’t thoughts it?
We’re looking for the bottom financial boundaries to seek out sustainable options. And changing whole polymer generations and applied sciences will not be economically viable. So are there different methods to form of hack these applied sciences and construct in sustainability in a approach that doesn’t require a whole revamp? Completely. And since we’re a middle, we’re lots of people working collectively. We’re kind of know-how agnostic. If it’s a brand new materials completely or if it’s a modification of an present materials, each of these are a good answer to the issue.
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