Vaporizing plastics recycles them into nothing but gas

43 pointsposted 3 hours ago
by bell-cot

25 Comments

orbisvicis

2 hours ago

Are propylene and isobutylene really in such high demand that this process is worthwhile, as opposed to chucking all plastics (without sorting) into a plasma gasifier, which for plastics generates just syngas?

Out of curiosity, how often are new plastics invented, and how often are those plastics difficult to recycle?

For example I'm finding that modern computer cables are sheathed in a much more durable (less brittle) form of plastic than those from 10+ years ago. Or is that just the addition of pthalates?

Edit: plasma gasification does still produce tar, as per [1], but much less than standard gasification. There isn't much review on the effects of applying plasma gasification to plastics.

1. https://www.sciencedirect.com/science/article/abs/pii/S09560...

bee_rider

an hour ago

Is there any downside to using a plasma gasifier? I still see a lot of plastics around, so I guess(?) additional solutions are needed.

PaulHoule

3 hours ago

My take.

The current sense of a plastic waste crisis is that a certain fraction of plastic gets chucked outside and will find its way to the ocean where it will be mechanically broken down in harmful ‘microplastic’ and ‘nanoplastic’ particles. No form of recycling will work if people don’t use the bin.

If, in the other hand, people throw the plastic in the trash bin it will be buried and spend a long time (100-10,000 years?) underground and will at least somewhat decompose. Any environmental threat is kicked far into the future.

The trouble with chemical recycling is that it produces the kind of chemicals that come out of an oil refinery/petrochemical complex (which are used to make plastics) and those are all worth about 50 cents a pound.

create-username

2 hours ago

>No form of recycling will work if people don’t use the bin.

blaming consumers for the industry waste that's being released from their factories into the public environment is diluting responsibility. If the governments were not subjects of the big multinational petrochemical corporations, they should charge a deposit for every gram of plastic that customers acquire, similar to the German Pfand for plastic bottles and cans (0,25 euro cent).

If a plastic contains 33 grams of plastic as described in their QR code or instruction manual, charge the customer a deposit of 3,3 dollars for each product and pay the customer 3,3 dollars for bringing back that amount of plastic. The environment would be pristine

Plastic is cheap because the future generations are paying the price of pollution

galleywest200

an hour ago

Several US states have this program for glass and cans and yet both glass and cans are still found on the side of the road.

qwerty456127

21 minutes ago

> blaming consumers

Why not blame consumers which would dispose their garbage wherever they want instead of a bin? I would rather criminalize this. It's so easy to put an empty plastic bottle in a bin yet they insist on throwing it on the ground.

QuadmasterXLII

an hour ago

ok, but visit a beach in a country where the people put the plastic in a bin, and then visit a beach in a country where the people don’t put the plastic in a bin.

ForOldHack

2 hours ago

Almost all of the waste plastic comes from the offering of cheap wrappings by cheap companies (i.e. super conglomerates) used by cheap people who simply do not care. Make it expensive and all these people will complain you are impinging on their freedoms.

The oil industries will complain The single use plastic purveyers will complain and the lazy consumers will complain, yet exactly like Germany, it must be done.

Some people think it's cool to burn money, while others purchase unneeded AI farms.

We, companies who make, companies who sell, and consumers who use as well as permissive governments all dilute responsibility, and a vast majority of plastics I pickup are simply the tops of plastic food containers.

How many are sealing reusable containers? Zero. how many straws? Thousands.

Make plastic straws the gold standard for recycling. worst offenders? The top fast food venders in food deserts. Cheap companies serving cheap lazy customers.

The poster is absolutely right.

dflock

2 hours ago

Burying plastics results in leaching phthalates, estrogen mimics and assorted other crap into the ground, and groundwater, in the near term, not the far future.

actionfromafar

2 hours ago

Using less of it and standardazing on what kinds of plastic can be used + burn the waste seems the only reasonable solution to me.

jajko

an hour ago

Nobody is telling you to bury them in your backyard, modern landfills take all this and much more into account.

Now of course an average 3rd world country doesn't have any of that, but if you would actually travel there you would see plastics everywhere, in the sea, on random land, in the mountains, in the rivers etc. While still leaking what you wrote but way more directly.

Mistletoe

2 hours ago

Not saying it is perfect, but modern landfills are sealed on the bottom.

> Modern landfills are completely sealed to reduce contamination of the nearby groundwater. First, the ground is lined with clay. A thin layer of flexible plastic is placed on top of the clay layer. That allows the collection of leachate, the liquid that passes through the landfill and may draw out toxins from the trash. The leachate is collected though a drainage system that passes this contaminated water through pipes to a pool where it can be treated to remove the toxins before being released back into the environment.

https://education.nationalgeographic.org/resource/landfills/...

beerandt

2 hours ago

Yea, plastic in a landfill is basically the perfect form for 'carbon capture'. For those that think that carbon needs capture.

But acting like plastic isn't 100% bad goes against the narrative, and happens to align with those who don't think carbon needs capture. Just throw it away.

tpm

2 hours ago

The BPA and other additives will leak into water. PVC will break into VC and that will leak and cause cancer. And so on. Plastic is bad, especially single-use plastic.

bell-cot

2 hours ago

Yeah. Recycling is a long and problematic chain, and no magical miracle chemistry chain-link could change that.

OTOH, there's a lot of plastic that is discarded at larger scales (vs. Chris & Pat drop their empty bottles into bins), and a really good chemistry might make recycling a far better choice in those scenarios. And much of the world does not have well-run (especially long-term) landfills to put trash in. And there's a morale effect, too - if we quite reasonably can recycle some common types of plastics, that injects a bit of hopeful news into the generally miserable plastics recycling situation.

underdeserver

2 hours ago

Sounds promising, and plastic waste is a huge problem.

But the article doesn't address the biggest issues:

1) Do you need to separate types of plastics or clean them before using this process?

2) What are the challenges to scaling this? (They mentioned that this is an issue but didn't answer the question)

Sindisil

29 minutes ago

> 1) Do you need to separate types of plastics or clean them before using this process?

The whole second section of the article discusses this process on mixed plastics, including:

> Another test involved introducing different plastics, such as PET and PVC, to polypropylene and polyethylene to see if that would make a difference. These did lower the yield significantly. If this approach is going to be successful, then all but the slightest traces of contaminants will have to be removed from polypropylene and polyethylene products before they are recycled.

idunnoman1222

an hour ago

If this approach is going to be successful, then all but the slightest traces of contaminants will have to be removed from polypropylene and polyethylene products before they are recycled. - well they tried

bell-cot

3 hours ago

A much better title: Newly discover recycling chemistry might solve the intractable problems of polypropylene and polyethylene

anticorporate

2 hours ago

I agree. Wouldn't vaporizing anything recycle it into a gas, like, by definition? (If only temporarily.)

analog31

2 hours ago

Yes, but what gas? Maybe the title should have said either "useful" or at least "harmless" gas. The gases that come from basic polymers could be comparable in those ways, to the original petroleum. They could even be reformed into new polymers, or used as fuel.

By way of contrast: Vaporizing lead or mercury compounds, not such a good idea.

thecosmicfrog

2 hours ago

Thanks OP. I appreciate that Hacker News has rules on post titles so it's nice to see you self-correct in the comments!

PaulHoule

2 hours ago

Notably the easiest way to not run afoul of those rules is to not modify the title even if the original title is bad. You do have to squash titles down to the 80 char limit and the same way to do that is delete words, preferable noise words like “very” or “novel” and past that more complex transformations where you maybe change a passive construction into a shorter active construction.