I worked on a similar (but competing) technology to this one for a few years. Depolymerization is absolutely the way forward for most polymer recycling.
For most uses, manufacturers want plastic that’s colorless and has good physical properties. Melting down clear plastic can work, but it degrades the polymers in hard-to-control ways. And if there’s any pigment in the plastic, forget about it.
If you break down polymers into their constituent monomers, you’ve turned a polymer process into a chemical process. Polymers are hard to work with. Chemicals are, comparatively, pretty easy. You can do a step or two to extract all the color and impurities, then re-polymerize the cleaned up material and get plastic that’s indistinguishable from brand new.
If your depoly process is good, it can distinguish between different polymers, so you can recycle mixed waste streams. Ours was even pretty good at distinguishing nylon from PET, which I sorta doubt the zinc process will be. But hey, more competition in this space is gonna be good for the world.
Drawbacks are mostly the economics of it. You have to convince people to put time and energy into turning waste into monomers. If the monomers you get from crude oil are cheaper, you’ve got an uphill battle.
The catalysts can be complex, but the good ones are really simple. The zinc one in this article is pretty easy to understand. Ours was an organic molecule, but a really abundant and cheap one. (We could easily recover and re-use the catalyst, too, which I also doubt most of the metal salt catalysts are capable of). Part of the project was optimizing that catalyst. We found ones that worked a little better, but were like 10x as expensive. So we just used a little more of the simple one and figured out how to use it over and over.
I worked on a similar (but competing) technology to this one for a few years. Depolymerization is absolutely the way forward for most polymer recycling.
For most uses, manufacturers want plastic that’s colorless and has good physical properties. Melting down clear plastic can work, but it degrades the polymers in hard-to-control ways. And if there’s any pigment in the plastic, forget about it.
If you break down polymers into their constituent monomers, you’ve turned a polymer process into a chemical process. Polymers are hard to work with. Chemicals are, comparatively, pretty easy. You can do a step or two to extract all the color and impurities, then re-polymerize the cleaned up material and get plastic that’s indistinguishable from brand new.
If your depoly process is good, it can distinguish between different polymers, so you can recycle mixed waste streams. Ours was even pretty good at distinguishing nylon from PET, which I sorta doubt the zinc process will be. But hey, more competition in this space is gonna be good for the world.
So, what’s the drawback of depolymerization? Sounds cool. Does it use baby tears as a catalyst?
Drawbacks are mostly the economics of it. You have to convince people to put time and energy into turning waste into monomers. If the monomers you get from crude oil are cheaper, you’ve got an uphill battle.
The catalysts can be complex, but the good ones are really simple. The zinc one in this article is pretty easy to understand. Ours was an organic molecule, but a really abundant and cheap one. (We could easily recover and re-use the catalyst, too, which I also doubt most of the metal salt catalysts are capable of). Part of the project was optimizing that catalyst. We found ones that worked a little better, but were like 10x as expensive. So we just used a little more of the simple one and figured out how to use it over and over.