11 October 2022 |

Plastic as a carbon sink


Newsflash. See the image below? None of these containers will get recycled.

No, it’s not a matter of whether you try and recycle them or not. Simply put, the way recycling plants are set up can’t accommodate these odd shapes and sizes. Especially small products or materials are nearly impossible to recycle – products smaller than 2-3 inches in any direction don’t properly sort in most materials recovery facilities.

Unfortunately, this doesn’t mean companies can’t label them as ‘recyclable.’ They are recyclable in the sense that it’s possible, theoretically speaking. But again, based on how plants are set up to handle recycling work, they won’t get sorted properly and will end up in a landfill despite your and the recycling companies’ best efforts.

Of course, recycling recovery rates for plastic are pretty abysmal to begin with. Only 9% of virgin plastic in the U.S. avoided the landfill in 2021. Further, oil companies in general have intentionally misled consumers about plastic recycling; plastic is made from petrochemicals, generating demand for oil. Recovery rates for other materials, like batteries, are increasingly much, much better than those for plastic. For instance, CATL, one of the largest battery manufacturers in the world (based in China), recently touted 90%+ recovery rates for lithium with its battery recycling technologies.

To summarize, virgin plastic is big a problem. Knowing most of it, especially when used as a container for small products, ends up in landfills, what else might we do with it?

Here’s an idea. Use it as a carbon sink. Intrigued? Let’s explore this further.

Plastic as a carbon sink (“PaaCS”)

Nick Gardner, co- founder of Element Packaging, called me about a month ago with an interesting pitch. He’d heard the Keep Cool Podcast with CleanO2, a company that captures CO2 from natural gas boilers and turns it into household products, like soap.

He liked the idea of finding ways to valorize waste CO2. And he’s particularly familiar with another pernicious problem: plastic.

For his business, he helps companies make made-to-order plastic packaging for products in the beauty industry. Knowing 99.9% of these end up in landfills due to their size, he wondered whether that might not be a stable place to sequester carbon. Once in the landfill, that plastic isn’t going anywhere; it won’t break down for thousands of years. If the beauty industry has a plastic problem, maybe using it as a carbon sink can give it a (partial) facelift. 

Are landfills the next big carbon sink? Photo credit to Katie Rodriguez

Nick had also started shopping around and saw that other companies have been thinking about ways to valorize waste CO2 and use it in materials. There are companies like Carbon Upcycling that offer CO2 enhanced cement replacements. In Nick’s mind, plastic is no different:

If they can put it in cement, we can put it in packaging. Mineral fillers are already common in packaging.

Now, Nick is working with Carbon Upcycling’s consumer brand, Oco, a firm focused on helping people like Nick do what he’s trying to do. Namely, use CO2 to make new, novel, improved materials. Adding CO2 to plastic packaging could have a few benefits: 

  • The CO2 used in the plastic is stable. In a landfill, it’s sequestered for the long haul
  • Having studied what happens if and when the plastic does break down in the landfill, the CO2 in it can become a soil remediation agent
  • There’s indirect abatement of plastic. If 5% of your container is CO2-derived materials, that’s 5% less plastic, and consequently emissions from fossil fuels, needed to make it
  • The material itself is more robust. That’s part of the thesis behind adding CO2 to concrete, which works similarly for plastic.

One fair question is, what happens if the plastic is recycled? Adding CO2 to the material doesn’t impact recyclability – in fact, the addition extends the life of the polymer bonds making it more likely the material will last longer. That benefits sequestration as well as the amount of times it could conceivably be recycled. Only in very high heat, e.g., starting at 300° Celsius, would there start to be a slow release of CO2.

By the numbers

How much impact could PaaCS have? Nick and the Oco team helped me crunch some numbers.

  • By material composition, plastic containers for consumer goods and beauty products might include anywhere from 5-20% CO2-enhanced additives.
  • The team at Oco estimated that 10 tonnes of plastic might include 200 kg of directly sequestered CO2 (assuming 10% dosage of their additive).
  • So for every 10 tonnes of packaging, that’s also 1 less tonne of virgin plastic that needs to be produced (based on the 10% dosage).

By some estimates, the beauty industry is responsible for ~150M tonnes of plastic annually. At scale, putting carbon in plastic starts to become a sequestration solution for millions of tonnes of carbon every year. It’s not the billion-tonne carbon sink solution that carbon removal players hope they’ll need someday, but it’s a viable near-term reservoir for captured carbon. Plus, there’s more than just the carbon sequestration element at play here.

The net-net

This pitch for plastic as a carbon sink may seem a bit silly to some, but it’s a pragmatic solution that turns a pervasive problem (people want cosmetics) into a problem with some upside. If these types of packaging will end up in landfills, why not stick some carbon in them?

I’m not suggesting that we shouldn’t focus on using less plastic, innovating other alternatives, or improving recycling technology to reuse more of it. But it points to a bigger question. Where else might we start sticking carbon if the world begins capturing and removing it en masse?

Deep geological reservoirs will be an essential piece of the puzzle; the same way oil came up out of the ground and released a bunch of carbon when burned, we can stick carbon back into the ground in various forms. Beyond that, there are probably all kinds of innovative carbon sequestration options besides the all-important, natural carbon sinks that Planet Earth provides. Again, that’s effectively the mission statement of Oco – find all kinds of materials that would benefit from added CO2 content.

I also enjoyed my chat with Nick because it shows that every industry, from the most forward-facing climate tech companies to packaging manufacturers, is considering how to make their products and services more sustainable. Rome wasn’t built in a day. And each brick in the foundation of a more sustainable future counts, regardless of who lays it.

Will a major cosmetic brand adopt carbon-negative plastic packaging? TBD!