Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New plant-based plastics can be chemically recycled with near-perfect efficiency

academictimes.com

Post reply on HN
Print view View original

111–120 of 272 posts

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#111

Post by dheera »

mrfusion wrote: post #17
dheera wrote: post #8

Earlier quoted context omitted.

PLA is pretty useless as a material though for anything but art. Almost everything I print has a functional purpose and either (a) needs mechanical strength (b) will be placed outdoors in the California sun or (c) will be used to house electronics that may reach temperatures as high as 70-80 C. PLA is basically useless to me and pretty much all roboticists. I use PETG for almost everything because it works perfectly…

I’ve just been living with the downsides of pla. Should I just switch to petg? I have my printer in my bedroom though. Is petg toxi to breathe?

> I’ve just been living with the downsides of pla. Should I just switch to petg?

As far as utility goes it's so much sturdier as a material that I don't even comprehend why people use PLA, especially considering they are very similar in price, and it's much easier to work with than ABS since it is not particularly prone to warping. If PLA can realistically be composted though, that's another story, bu I was under the impression 3D print PLA isn't the same as compostable PLA cups.

> I have my printer in my bedroom though. Is petg toxi to breathe?

PETG is not known to be toxic, so it's a much better choice than ABS if you don't have a garage or fully ventilated area. That said, I'm always skeptical and I don't keep my 3D printer in my bedroom.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#112

Post by da_big_ghey »

mnouquet wrote: post #104
da_big_ghey wrote: post #88

Earlier quoted context omitted.

These are not solving land impact of human. We must have fewer human or live in smal space like in Tokyo and others city like it. Most human no have desire to do this. Batery take resources like lithium more than we have. Maybe Dyson swarm eating star energy output cause climate change of its own, fewer energy reaching earth surface. There is always impacts that human create. We only can for truly mitigate climate ch…

> We only can for truly mitigate climate change with reducing human numbers. Then you should welcome pandemic, genocide and war.

they are having some positive efect in long enough view. also they are having sufering first. best is not to have as much persons born.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#113

Post by xyzzy123 »

maxerickson wrote: post #107
xyzzy123 wrote: post #105

Earlier quoted context omitted.

Bulk shipping to asia in particular is very cheap due to the volume of empty containers going in that direction. Not sure about other places. Countries that recycle plastic have people pick out the good bits cheaply in hellish facilities, profit off selling the high grade recycling, the rest is "waste waste" to be gotten rid of somehow. Dumping it in the ocean is quite cheap. The sorted plastic used to be a thing tha…

In the US, dumping stuff in the nearest landfill is pretty likely to be cheaper than dumping it in the ocean. Especially if the landfill is operating the recycling sort (the case here and many other smaller counties). (This addresses your second paragraph; if they are selling the high grade and putting the rest in the landfill...)

The first reason it's hard to just landfill it is optics. Local government asked people to sort their trash, made a big deal about it. And it's a scandal when people find out of course it's just being buried with the rest of the stuff. Recyclers were able to do two things; a) play a shell game which diverts the waste in an opaque, hopefully deniable way and b) deal with the waste more cheaply than landfilling it. They did this by exporting it, and all the externalities.

I mean, your argument is good but I feel it's contradicted by reality in a sense; megatons of waste plastic were being sent to China before the import ban.

You have to pay to put stuff in landfill, whereas the recyclers were paying _you_ to take the waste.

I think you might also be surprised by the cost of landfill. Sure, there's plenty of space, but there's not as much government approved, environmentally audited space as you might want - that won't leach into the water table, has good geography, neighbours who won't NIMBY it, no rare frogs that live there etc. Obviously it all needs ISO 27000 management, union labour and regular safety and environmental audits.

Caring about none of the above is how Chinese waste entrepreneurs could take mixed plastic from 1/2 way around the world and make a profit out of it, instead of losing money putting it into the ground. Their margins are slim and they have to pay for landfill too (much less of course), so dumping it in the ocean or similar saves money unless they get caught.

(For what it's worth I do agree that putting it in the ground might be the best thing to do, i.e, cheapest considering all externalities, and local government should just be transparent about what actually happens to your recycling).

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#114

Post by dheera »

tomcam wrote: post #47
mnouquet wrote: post #42

Earlier quoted context omitted.

Shred, heat and extrude.

Thank you very much. Not sure why my question was downvoted.

I do wish it were required to give a reason or comment to downvote. I upvoted you to compensate since the downvoter did not do this.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#115

Post by Spooky23 »

tachyonbeam wrote: post #35
ArkanExplorer wrote: post #7

Plastic recycling seems heavily motivated by emotion and virtue signaling. In reality, only about 5% of our crude oil use goes towards plastic. If we rolled out EVs, and then just burned all the plastic trash (using waste-to-energy plants), we would still be far ahead. The biggest challenges with plastics are hormone disruption, and microplastics (particularly in the 3rd world without sufficient landfill or W2E infra…

I think we should recycle plastic if we can, or better yet, switch to other materials that are easier to recycle. For example, glass bottles can just be sent back to the factory, washed and reused. This is already done for beer and wine AFAIK. It could be done for milk and every other kind of drinks as well. However, if we fail to recycle plastic, isn't burying plastic in a landfill, in a way, a form of carbon captur…

You cannot win this argument.

One concerned citizen will point out that glass is heavier and supposedly uses more diesel to move around and requires more trucks to do so. Another concerned citizen will point out that more carbon is used in firing sand into glass. Still another will tell you that the warm water used to clean a used bottle will also produce carbon.

The only answer is to move next to a spring and drink the water with your hands, but some other person will be concerned that you are disrupting the spring’s ecology.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#116

Post by malloryerik »

jvanderbot wrote: post #26
ArkanExplorer wrote: post #7

Plastic recycling seems heavily motivated by emotion and virtue signaling. In reality, only about 5% of our crude oil use goes towards plastic. If we rolled out EVs, and then just burned all the plastic trash (using waste-to-energy plants), we would still be far ahead. The biggest challenges with plastics are hormone disruption, and microplastics (particularly in the 3rd world without sufficient landfill or W2E infra…

I believe plastic recycling is not motivated by oil use primarily. I believe it is motivated by trash accumulation in oceans and the food chain (microplastics). There are a ton of areas of the world where plastic just piles up.

What about biodegradable plastics? If regular plastics were made illegal or heavily taxed, wouldn't industry quickly come up with biodegradable alternatives?

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#117

Post by maxerickson »

xyzzy123 wrote: post #113
maxerickson wrote: post #107

Earlier quoted context omitted.

In the US, dumping stuff in the nearest landfill is pretty likely to be cheaper than dumping it in the ocean. Especially if the landfill is operating the recycling sort (the case here and many other smaller counties). (This addresses your second paragraph; if they are selling the high grade and putting the rest in the landfill...)

The first reason it's hard to just landfill it is optics. Local government asked people to sort their trash, made a big deal about it. And it's a scandal when people find out of course it's just being buried with the rest of the stuff. Recyclers were able to do two things; a) play a shell game which diverts the waste in an opaque, hopefully deniable way and b) deal with the waste more cheaply than landfilling it. The…

I've literally been in the local facility that sorts recycling, they do a good job of sorting clean stuff by type and throw everything else away, into the landfill where it is located. Should I not believe my lying eyes?

So someone pays to haul stuff away on trucks and I'm supposed to believe that they are dumping that stuff in the ocean for some reason. Or shipping it to China and then dumping it in the ocean.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#118

Post by JulianMorrison »

bluGill wrote: post #68
joshspankit wrote: post #32

Earlier quoted context omitted.

Off-topic, but sometimes I feel like we could harvest the plastic from the ocean, make plastic bricks, and build millions of houses. Edit: Just to be clear, I’m not trying to say that this is a viable solution to anything, or that it’s a good use of resources based on our current methodologies. I’m more just trying to say that there’s so much raw material out there and that it’s better if it comes out of the ocean. L…

Your edit is where the problem is. Sure there is a lot of plastic in the ocean, but the ocean is big as well. As a whole the size of the ocean cancels out your attempts to do any recovery. You end up using more energy to power the filters (which are typically on ships) than you would by taking the oil powering the filters and directly turning it into plastic. Plastic in the ocean isn't an easy problem to solve with a…

You're assuming smaller plastic is better.

You should probably stop assuming that.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#119

Post by mnouquet »

da_big_ghey wrote: post #110
mnouquet wrote: post #101

Earlier quoted context omitted.

> one-child policy better serve this need Over my cold dead body [and I won't go without a fight.].

This more extreme usonian gun and freedom idea. If government say you have only one child you hav xr15 rifle not help. you people no can be trust with guns, ability to have as many children as wanted, others. you try use them to continue kill planet. you no have freedom to keep breeding kill other country with climate change. US having more children is externality it not pay. the US days of telling world around and d…

> If government say you have only one child you hav xr15 rifle not help

What are they gonna do, line me up and execute me and my family ? Kill my children ? Fortunately, Rights are still a thing, including the 2nd.

Re: New plant-based plastics can be chemically recycled with near-perfect efficiency

#120

Post by barney54 »

malloryerik wrote: post #116
jvanderbot wrote: post #26

Earlier quoted context omitted.

I believe plastic recycling is not motivated by oil use primarily. I believe it is motivated by trash accumulation in oceans and the food chain (microplastics). There are a ton of areas of the world where plastic just piles up.

What about biodegradable plastics? If regular plastics were made illegal or heavily taxed, wouldn't industry quickly come up with biodegradable alternatives?

It’s not easy to find good biodegradable alternatives for many types of plastics. See the example of Legos trying to replace their plastic with a more environmentally friendly version. https://www.wsj.com/articles/lego-struggles-to-find-a-plant-...
Post reply on HN