By: Ethan Sontarp ‘24
In its current state, only a fraction of the plastic types we use on a daily basis is actually recyclable, accounting for an 8.7% recycling rate. While the process may be limited, sustainability researchers have been working to make improvements in the materials we recycle in order to reduce our consumption of single-use plastics. In this interview, I discuss the chemistry of recycling with Paul Chirik, Edwards S. Sanford Professor of Chemistry, whose lab recently discovered a plastic material with the potential to be recycled more effectively.
Image Credit: Paul Chirik via https://chirik.princeton.edu/
Could you give a brief overview of your current research? What makes it interesting to you?
So, what I do is I study catalysis. That’s a key component of sustainability because what catalysis does is by definition it makes chemical processes use less energy. The question we asked is: Is catalysis as sustainable as it can be? That’s the cool part of sustainability research – you can always do better. You can always save a little bit more [energy] here and there. One of the big things we’ve been after for a long time is that we’ve looked at the way people use catalysts; usually, they’re based on rare elements like platinum and palladium (all the stuff in the catalytic converter in your car). Nobody would argue catalytic converters are bad, they’ve completely cleared up the air and the environment from car exhaust, but at the same time, we’re using elements that come out of mines that have really huge carbon footprints. So, the [goal] is to use these great catalysts with iron and try to make all these reactions go better with less energy input [and] generate less waste. I think the most exciting thing is that we started doing this trying to make catalysts to insert into existing processes, and then when you start playing with new metals and new catalysts, you discover things you never thought you would see.
Image Credit: BBC News via https://www.bbc.com/news/science-environment-45496884
What does the current recycling process for plastics look like? How would you like to further improve it?
I think people are now appreciating how bad it is. You know, I actually feel a little guilty as a chemist, I didn’t realize how bad it was until we started studying it. I figured every week we put our milk jugs at the end of the curb and they went away and all is well, and you don’t realize the percentage of plastic that gets recycled is so low. That tells me there’s a chemistry problem here, the biggest part of it is we need new materials. We use a lot of plastic that it doesn’t make sense to recycle.
What does sustainability mean to you? How do you engage with sustainability outside of your scientific work?
Sustainability to me means a way of life, right? I think it should be how you interact with the environment around you. Outside of my job, I try to practice what I preach which is looking at how much stuff I throw away, how much I consume […]. You have to ask yourself what kind of carbon footprint you think you have and compare that to what you actually have. I think the most impactful thing I can do is educate people, because of the kind of science we do.
What is your favorite source of sustainable energy and why?
If you ask me as a chemist where we need to be in 100 years, we need to rely on the sun. It’s free, there’s lots of it. The problem is we don’t know how to do most of [the chemistry] yet. We have a long way to go but that doesn’t mean you give up, because it’s a really hard problem.
What are some common misconceptions about energy sources?
I think the biggest misconception is that people think that fossil fuel is only for gasoline in their car. They don’t realize that you cannot live without interacting with multiple products [of fossil fuels], whether it’s your clothes or carpets, [even] the food you eat was grown from fertilizer that was made from fossil fuels. Just about every single product you interact with […] had an interaction or derivation from fossil fuels.
Are there any sustainability or climate science resources you know of that you would suggest for readers?
I pay a lot of attention to elemental usage. Hopefully, people worry about their carbon footprint, but that’s still very narrow, you should worry about your element footprint. Your cell phone has 65 of them in it, and some of those elements take a lot of energy [to obtain].
Discover where the elements which make up your smartphone are sourced from:
https://www.nms.ac.uk/explore-our-collections/resources/from-minerals-to-your-mobile/
Image Credit: National Museum of Scotland via https://www.nms.ac.uk/explore-our-collections/resources/from-minerals-to-your-mobile/