Exploring Hydrocarbon Depletion
Page added on April 26, 2012
Dr Debbie Chachra is a materials scientist: an engineering professor at the Franklin W. Olin College of Engineering (Deb’s bio at Olin), and a prolific writer. She also produces one of my favourite tumblrs, Daily Idioms. Basically, I learn something every time Deb writes anything. So I asked her to write to you about whatever was on her mind, and she said this:
Plasticity has its grand tradition and main stream, which happens to flow by way of du Pont and their famous employee Carothers, known as The Great Synthesist. His classic study of large molecules spanned the decade of the twenties and brought us directly to nylon, which not only is a delight to the fetishist and a convenience to the armed insurgent, but was also, at the time and well within the System, an announcement of Plasticity’s central canon: that chemists were no longer to be at the mercy of Nature. They could decide now what properties they wanted a molecule to have, and then go ahead and build it.
Thomas Pynchon, Gravity’s Rainbow (1973)
I’m a materials scientist by training, and that means that I spend a lot of time thinking about the stuff that makes up our physical environment. How plate glass is an unappreciated marvel, manufactured by floating infinite ribbons of optically-clear glass on canals of molten tin. Or how aluminium went from being a gift for kings to being, literally, disposable with the advent of large-scale electricity generation.
And one of the things I’ve been thinking about recently is peak plastic.
The use of oil for fuel is dominant, and there’s a reason for that. Oil is remarkable—not only does it have an insanely high energy density (energy stored per unit mass), but it also allows for a high energy flux. In about 90 seconds, I can fill the tank of my car—and that’s enough energy to move it at highway speeds for five hours—but my phone, which uses a tiny fraction of the energy, needs to be charged overnight. So we’ll need to replace what oil can do alone in two different ways: new sources of renewable energy, and also better batteries to store it in. And there’s no Moore’s Law for batteries. Getting something that’s even close to the energy density and flux of oil will require new materials chemistry, and researchers are working hard to create better batteries. But this combination of energy density and flux is valuable enough that we’ll likely still extract every drop of oil that we can, to use as fuel.
But if we’re running out of oil, that also means that we’re running out of plastic. Compared to fuel and agriculture, plastic is small potatoes. Even though plastics are made on a massive industrial scale, they still account for less than 10% of the world’s oil consumption. So recycling plastic saves plastic and reduces its impact on the environment, but it certainly isn’t going to save us from the end of oil. Peak oil means peak plastic. And that means that much of the physical world around us will have to change.
Plastic is more than just water bottles and Tupperware. If you’re indoors, look around. There’s a good bet that much of what’s in your field of view is made of plastic. Paint. Carpeting. Upholstery. The finish on a wood floor. Veneer on furniture. And that’s before you go into your kitchen, or bathroom, and never mind a subway car or a hospital (disposable, sterile medical supplies, anyone?). Plastic is so ubiquitous that it’s almost invisible.
In the last century or so, chemists and chemical engineers have done as Pynchon described, and developed thousands of plastics for use in tens of thousands of applications, if not more. That means that we’ll need to find replacements for these oil-based plastics for every one of those uses, probably from previously unconsidered renewable sources. It’ll be a different world.
There’ll likely still be applications that really need petroplastic, so landfills will become goldmines. The characteristic drawback of plastic, its stubborn resistance to degradation (‘this plastic bag will still be around in ten thousand years!’) will become a virtue, as it sits unchanged in anaerobic landfills waiting for us to decide that it’s worth excavating and recycling. And one day we’ll do just that–there’ll come a point when the easy, albeit expensive, way to get a particular combination of properties (formability, degradation resistance, sterilisability) will be to dig up post-consumer plastics and reuse them.
And one day in the future, cool, slick petroplastics will become a repository of warm nostalgia. I like to imagine the Brooklyn-hipsters-of-the-future, on their rooftops, using vodka and bitter almond oil to make artisanal polyethylene.