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Cleaning plastic from our oceans - The Ocean Cleanup Venture

Ronen E

Problem Solver
Staff member
Super Moderator
#12
This is not encouraging--and I eat a lot of fish (rather than meat).
If you care about the environment you shouldn't be eating anything out of the oceans. They are already devastated (some say beyond repair) and you are sponsoring their continued destruction.
I suppose plastic-to-oil would at least destroy the microplastics (and produce a saleable product) assuming they could be collected which is not a sure thing because a lot of them sink in the ocean.
Always look for the $ trail. Whatever drives profit will prevail. Whatever doesn't will hardly fly.
 
#13
If you care about the environment you shouldn't be eating anything out of the oceans. They are already devastated (some say beyond repair) and you are sponsoring their continued destruction.

Always look for the $ trail. Whatever drives profit will prevail. Whatever doesn't will hardly fly.
Profit is necessary to make anything work. Henry Ford made a lot of money by finding ways to reuse what would have otherwise been waste, such as waste wood--that is how we got Kingsford charcoal.

A problem with plastic recycling is that you have to sort it. Some plastic products are not identified by recycling classification and of course microplastics fall into this category. They do however contain a lot of carbon and hydrogen (fuel) that is polymerized and, if the polymer can be broken up, the product can be sold as (for example) heating oil but fuel is probably the least optimum use. Maybe the products could be sold as chemical process feedstocks to produce higher-value products including more plastics (which, at the end of their useful life, can be reprocessed yet again). Which reminded me to look at what happens when you mix supercritical steam--that is water that is so hot and under such high pressure that there is no longer a difference between liquid and solid--with plastics.

Supercritical solution
"The world is paying increasing attention to the broad concepts of sustainability and circulatory economics. This focus will certainly affect plastics recycling in the near future. In particular, discarded plastics that are accumulating in the world’s oceans and waterways are clearly evident and negatively viewed. " and it mentions Boyan Slat and the Ocean Cleanup.
 

Ronen E

Problem Solver
Staff member
Super Moderator
#14
Profit is necessary to make anything work.
I agree that profit is a strong driver (this is essentially what I was saying) - that's the reason IMO that recycling is taking off so slowly or not at all (depends on where and what). But I think that profit is not the only human motivator. Perhaps a more accurate statement would be "Profit is necessary to make anything work in the current prevailing capitalist system".
They do however contain a lot of carbon and hydrogen (fuel) that is polymerized and, if the polymer can be broken up, the product can be sold as (for example) heating oil but fuel is probably the least optimum use.
I see this as an oversimplified view. The question is what does it take (and how much it costs) for "the polymer to be broken up" properly. Not everything containing carbon and hydrogen is readily-beneficial fuel. It is the manner of how the elements are arranged together (typically with other intentional elements, and don't forget contaminants) that matters. Yes, you can burn most plastics waste, but the sum total of your operation (including retrieval) is not necessarily positive, certainly not in $ terms. Additionally, when you burn a mixture of (somewhat unknown composition) plastics under conditions that aren't optimised, and sometimes aren't really controlled, you run a real risk of generating and releasing significant harmful pollution.

In short, there's a lot of wisdom in the triple-R approach, and these Rs order DOES matter. Only it's so much easier to go on doing what we always did, then cry about freak storms, floods, heatwaves and wildfires.
 

Marc

Captain Nice
Staff member
Admin
#15
A problem with plastic recycling is that you have to sort it.
The latest I have seen is robotic "pickers" which practically eliminate humans for separating plastics on a moving line. I can't remember where I saw it - Probably in a news article. The robot arms moved very fast and were said to be very accurate.

It does still come back to how much can actually be recycled. Many plastics can not be recycled into plastics again. Then again:

Plastic bottle homes

How to Construct Houses With Plastic Bottles !!

The house that Tateh built ... out of sand-filled plastic bottles
 

Ronen E

Problem Solver
Staff member
Super Moderator
#16
The latest I have seen is robotic "pickers" which practically eliminate humans for separating plastics on a moving line. I can't remember where I saw it - Probably in a news article. The robot arms moved very fast and were said to be very accurate.
Like every engineering task, there are clever ways to go about it. Just as an example, it's generally possible to separate polyolefins (PE, PP etc.) from other plastics through floating/sinking in water - polyolefins' specific gravity is normally <1, while some other palstics are >1 (water is 1 of course).

At the end of the day, it all comes down to the question of whether it can be made economical, large-scale. No one will buy the end products if they cost more (and are lower quality) than virgin resins. Anecdotal success stories are nice and maybe inspiring, but to make a real difference it has to succeed large-scale.

It does still come back to how much can actually be recycled. Many plastics can not be recycled into plastics again. Then again:

Plastic bottle homes

How to Construct Houses With Plastic Bottles !!

The house that Tateh built ... out of sand-filled plastic bottles
This is the 2nd R - Reuse, which is better than the 3rd - Recycle. But again, I'm afraid it's quite anecdotal. I remember reading a similar story in National Geographic Magazine in the 80s or 90s (can't remember). I think in that story it was glass bottles and aluminium cans though.
The best choice is the 1st R - Reduce. But it's also the hardest.
 
#17
The latest I have seen is robotic "pickers" which practically eliminate humans for separating plastics on a moving line. I can't remember where I saw it - Probably in a news article. The robot arms moved very fast and were said to be very accurate.

It does still come back to how much can actually be recycled. Many plastics can not be recycled into plastics again. Then again:

Plastic bottle homes

How to Construct Houses With Plastic Bottles !!

The house that Tateh built ... out of sand-filled plastic bottles
I did read about these. If the bottles are empty they are excellent insulators but the question is how to reinforce them. I can see how sand-filled bottles could serve as bricks, and they do not come apart in the rain like sun-dried bricks. Essentially free building materials that turn waste into something useful.

They apparently used amphorae for this purpose back in Rome. 8 Glass Bottle Houses | BEACH
 

Ronen E

Problem Solver
Staff member
Super Moderator
#18
Essentially free building materials that turn waste into something useful.
Anecdotally, maybe. But at any significant scale, they're only free to the extent that someone has already invested enough to make them available at the right place, time and condition.

To make a real dent, and to solve technical issues (like reinforcement which you brought up), things have to be standardised to an extent, and that means that some sort of system must first be put in place. These things cost money.
 
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