How does chemical recycling work for plastics?

Ever wondered what happens to that plastic water bottle after you toss it into the recycling bin? While traditional mechanical recycling (the crushing and washing process we all know) does a decent job, there’s a game-changing alternative gaining traction: chemical recycling. This isn’t your grandma’s recycling method—it’s like giving plastics a “second life” at the molecular level, and frankly, it’s about time we talked about how this sci-fi-sounding process actually works in real life.

Breaking plastics down to their building blocks

Chemical recycling, sometimes called advanced or molecular recycling, takes a completely different approach than mechanical methods. Instead of just melting and reshaping plastics, it breaks polymers back down into their original chemical components through various chemical processes. The most common methods include:

• Pyrolysis: Uses high heat (300-800°C) in an oxygen-free environment to break plastics into smaller hydrocarbon molecules
• Gasification: Converts plastics into syngas (a mix of hydrogen and carbon monoxide) using controlled amounts of oxygen
• Solvolysis: Employs solvents to depolymerize specific plastics like PET or PU back into monomers

What’s fascinating is that these methods can handle plastics that mechanical recycling typically rejects—dirty containers, multi-layer packaging, even those pesky black plastics that optical sorters can’t detect. A 2022 study by Closed Loop Partners found chemical recycling could potentially divert an additional 5-15% of plastic waste from landfills.

The real magic: Creating virgin-quality plastic

Here’s where chemical recycling really shines. While mechanical recycling produces plastic that’s often lower quality (known as downcycling), chemical processes can create materials indistinguishable from virgin plastic. Eastman Chemical’s methanolysis process, for instance, breaks down PET into dimethyl terephthalate and ethylene glycol—the exact same building blocks used to make brand-new plastic bottles.

Industry leaders are taking notice. Coca-Cola recently partnered with Infinite Loop to produce bottles made entirely from chemically recycled PET. Meanwhile, startups like Agilyx can transform polystyrene waste back into styrene monomer with 90% yield—something impossible with traditional methods.

Not without its challenges

Let’s be real—chemical recycling isn’t perfect. The energy requirements are substantial, with pyrolysis typically needing 3-5 times more energy than mechanical recycling. There are also legitimate concerns about emissions from some processes, though newer plants are implementing carbon capture technologies. And at $3,000-$5,000 per ton processing cost (compared to $200-$300 for mechanical), the economics still need work.

But as regulations tighten (the EU’s Single-Use Plastics Directive is just the beginning) and technology improves, chemical recycling could be the missing piece in our circular economy puzzle. After all, with plastic production projected to triple by 2050, we’ll need every tool in the toolbox to keep our oceans and landfills from drowning in waste.