If you ever read news stories about recycling on your phone, your newsfeed probably showed you something exciting this past week. French scientists published a paper in Nature describing a new enzyme that breaks down the common plastic PET at a surprisingly rapid speed with unprecedented effectiveness.
PET makes up disposable plastic water bottles, some cosmetic containers, soda/pop bottles, and most containers that are made of a clear, flexible plastic. Estimates have that about 70 tons are produced per year. Recycling processes today can only recover 30% of a batch of perfect, clean, sorted PET Forbes). Understandably, then, PET makes up a big part of plastic pollution.
The PET recycling rate is so low because, when melted, residues and dyes that are part of your typical PET packaging product remain mixed in. Rarely is the mixture “right” for the material to be reused in a new container – it’s usually down-cycled into fibers for sweaters, sleeping bags, jacket insulation and even carpets, where muddled mixtures of gray color are more acceptable.
In a laboratory test, this enzyme successfully converted 90% of sample PET into reusable monomers in a matter of 10 hours. The output is 90% reusable because the enzyme ignores the dyes and additives, and spits out good old, standard PET with all the likeable characteristics of virgin PET. That’s a big deal. Understandably, everyone and their mother is talking about it. And their uncle. And their roommate’s ex-girlfriend. And her Physics 101 professor. Mark my words, every news outlet that wants to show the world they’re green and trendy is going to crank out a piece on this by the end of the month.
If you’re eager to know about the science behind this PET-smushing enzyme, any of the links in the previous paragraph (and footnotes) will take you to articles by real journalists that brilliantly explain the research and implications of this technology. However, I’m going to address a different angle: how well does this new technology really arm us in the fight against plastic pollution?
This development will certainly rescue tons upon tons of post-consumer plastic from landfills and oceans. In a nutshell, though, it will be too little, too late. 70 million tons of PET are manufactured annually, and given current plans, plastic production is expected to triple by 2050. Meanwhile, Carbios (the company developing the enzyme) will only have the first plant up and running by 2024, and it will process mere hundreds of tons per year. Even if the capacity doubles every two years, the process won’t be able to recycle half the new PET that’s made until well after 2050. From 2020 till 2050, there will be over 2.7 billion new tons PET that was not reused, and most of that will be unrecoverable after years of sitting in mixed landfills or breaking into microplastics in the soil or ocean.
What’s more, a doubling in capacity every two years is fantastically unrealistic, given the economics and the complexity of materials processing. Estimates by the Carbios team show that this recycled plastic would be more expensive than virgin PET (from crude oil or natural gas) to produce. They (and I) suspect that many customers would be willing to pay a premium for recycled plastic – but in order to truly battle virgin PET for share of the wider market, the recycled PET will need to be cheaper. Further innovation and economies of scale may push the Carbios process there in the long-term, but meanwhile the PET recycling capacity will struggle to grow at a significant rate.
In the end, Carbios’s enzyme is only a slice of the “how do we deal with plastic pollution?” pie. Reducing production is necessary. While a large amount of plastic is necessary for our society to function (last blog post), PET is largely used for single-use containers to package food, beverages, cosmetics, sporting equipment, and pharmaceuticals. For the sake of sanitation, some food, beverage, and pharmaceutical packaging must continue to be disposable PET, but a fairly large chunk (e.g. disposable water bottles) are unnecessary. To this end, it might seem suspicious that Carbios’s industrial partners include Pepsi and L’Oreal, who ship out billions of products in unnecessary PET packaging. Could this project be an excuse for these companies to get “green credit” while continuing to rely on wasteful packaging? For now, I’m optimistic that these companies’ support is a sign of taking responsibility for years past of cranking out PET bottles. However, they need to show the world – and quickly – that they are taking steps to replace single-use plastic packaging with sustainable alternatives.
This is an exciting development that will keep a good many water bottles out of the oceans – but in the excitement we should not forget that larger, systematic changes are required to truly make progress. Keep this in mind for when the next flashy news update about a miracle recycling technology that will rid our oceans of plastics once and for all. This may be just what plastic industry PR wants you to think.
While many of these solutions need to come from the top – such as those in control of global packaging and distribution operations – there are things that everyone can do to pressure companies to move in the right direction. Next week, I’ll introduce you to one simple, massively helpful trick that requires almost no change to your day-to-day routine. But in the meantime, do you have any ideas on ways that the average citizen can act to reduce plastic waste? Please share in the comments below! I’d love to share any particularly juicy tips in a future post.
Here are even more articles about this miracle enzyme. It must be a slow news month:
Explanation of each line in the PET Production and Recycling chart:
- Produced shows the volume of PET in 2050 being 3 times that in 2020, with a constant yearly exponential growth interpolated between them.
- Standard Recycling is 30% of the value of Produced.
- Carbios Method starts off at 500 tons in 2024, to approximate the “hundreds of tons” that the industrial partnership will be able to process when its new plant opens in 2024. After 2024, it doubles every two years, or multiplies by square root of 2 each year.