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Comment by djsumdog | Hacker News Reader

I feel like I see one of these every few years. I remember the Japanese one from a while back:

https://www.youtube.com/watch?v=qGGabrorRS8

The article does mention this particular technique tries to get bigger yields and remove the need of sorting that other methods require. If it works as they claim, I could see it working for mining landfills, but when it comes to plastic patches in the ocean, I have trouble seeing a ship being able to recover enough plastic to be greater than its fuel use skimming through it.

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> I have trouble seeing a ship being able to recover enough plastic to be greater than its fuel use skimming through it

There are passive technologies that claim to be able to skim plastic from the ocean:

https://www.theoceancleanup.com/technology/

It goes further back then that. The 1980 Supreme Court patent case Chakrabarty v. Diamond was about oil eating bacteria that could be used to clean up oil spills. Not the same, but similar category. It was a very important case for patent law, but the technology was never commercially developed.

For the patent law nerds out there, it's a pretty great case to get acquainted with: https://en.wikipedia.org/wiki/Diamond_v._Chakrabarty

> I have trouble seeing a ship being able to recover enough plastic to be greater than its fuel use skimming through it.

I don't think this would be the idea.

I think by making it worth money to recycle the plastic it doesn't get into the oceans.

It's certainly not worthwhile trying to getting the existing plastic out of the oceans, this has been well covered by engineers.

You don't even have to recycle it. Burning it for heat energy is enough. Most plastic only produces water and co2 when burned...

Are you sure about that? As a younger person I burned a few samples of various things called 'plastic' and the fumes sure smelled like maybe I should be sterile by now.

Plastics tend to consists of carbon and hydrogen chains. See for example polycarbonate [1], polyetene [2] and ABS [3] (contains nitrogen). They might however contain all sorts of additives. In order to produce just water, carbon dioxide and nitrogen the burning must be carefully controlled [4] - in your experiment the burning was probably not complete, which explains the fumes (that might have been carcinogenic [4]).

[1] https://en.wikipedia.org/wiki/Polycarbonate

[2] https://en.wikipedia.org/wiki/Polyethylene

[3] https://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styren...

https://en.wikipedia.org/wiki/Plastic#Incineration_of_plasti...

You generally don't want to burn halogenated plastics like PVC though. As I understand it that will release highly toxic dioxins (which cause cancer and birth defects among other things) unless they are incinerated at high temperatures.

I don't know why this is downvoted, it's correct - incineration of plastics is needs to be done at high temperatures to avoid this problem.

Maybe it was PVC. That releases plenty of nasties when you burn it.

Ditto, the sibling posts seem to cover it except for printed plastics, even if the plastic is good the printing probably wasn't/isn't.

"the fumes sure smelled like maybe I should be sterile by now"

You, sir, have just enriched the English language.

The C in PVC stands for chloride. Wikipedia claims it is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene, which are pure carbohydrates.

So, technically, it is 'most', but chances are fairly good a random selection of garbage plastic contains chloride, too, and that can be nasty.

> It's certainly not worthwhile trying to getting the existing plastic out of the oceans, this has been well covered by engineers.

Can you link to some info on this?

Well here's a couple of articles quoting scientists. I mean the idea doesn't pass a smell test. If plastics are bad in the oceans how can you remove them in something so big without wiping out ecosystems at the same time?

One of the quotes (theoceancleanup) here is a idea from a 17 year old teenager (now 22) who was kickstarted. This also fails a pretty big smell test.

https://www.theguardian.com/environment/2016/mar/26/ocean-cl...

https://www.kcet.org/redefine/6-reasons-that-floating-ocean-...

Compared to something simple like collecting it before it hit the oceans and you can dump it into something cheap like a truck and process it which it's easy to see how it does work?

There are natural "gyres" in the oceans that collect garbage - see this link for the "Great Pacific garbage patch" (https://en.m.wikipedia.org/wiki/Great_Pacific_garbage_patch). It's about the size of Texas and has a significant amount of plastic in it, although of smaller sizes. That would seem to be a great place to focus these collection and conversion efforts.

Except even in those places the density of plastic is very low.

> 200,000 pieces per square kilometer in the North Atlantic garbage patch.

> 4 particles per cubic meter in the Great Pacific garbage patch.

https://en.wikipedia.org/wiki/North_Atlantic_garbage_patch

https://en.wikipedia.org/wiki/Great_Pacific_garbage_patch

It's a serious problem, but it's one that requires people to stop using so much plastic; to make sure they re-use plastic; and to make sure that plastics are recycled after use.

Microbeads in cosmetics and microfibres from clothing are a huge problem.

So much this and I don't know that we really have an answer to fix this. This micro things are toxic to the entire aquatic ecosystem.

Part of the answer is simply to stop using non-biodegradable stuff in cosmetics.

It isn't difficult to do. All that is needed is an incentive like making inclusion of plastic micro-beads illegal. Isn't California considering doing that?

Wow, that is encouraging. I hope that is true and gets passed. It could mean the end of yoga pants (they are good and bad) so I'm not sure how I feel about this. :)

> I have trouble seeing a ship being able to recover enough plastic to be greater than its fuel use skimming through it.

Surely it could just be solar powered? Autonomous even?

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