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Scientists break down plastic using a simple, inexpensive catalyst and air

phys.org

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Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#101

Post by thrance »

whywhywhywhy wrote: post #79
thrance wrote: post #51

Earlier quoted context omitted.

And Trump reverted the ban on plastic straws. One step forward, three steps backwards...

Always seemed like greenwashing to care about the straw in the drink that’s on a plastic cup with a plastic lid from the beans shipped in a plastic bag and render the experience of trying to drink it as tedious as possible.

The solution is not to unban them, it's to ban those plastic things too. And c'mon, paper straws are fine, people whining about it really just do it to vice signal against ecology.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#102

Post by Steve44 »

piokoch wrote: post #50

There is no such a thing like "plastic". The article is about PET - polyethylene terephthalate, there are hundreds other "plastics", which different chemical propensities. The problem is not actual act of recycling, but figuring out what a given piece is made of. PET is popular - 70% of all bottles are made of it, but there are those 30%, so the most expensive part - sorting - has to be carried anyway. Plus we target…

> Why we allow making packages (especially for take-away food from pseudo-paper (which is a paper with plastic coating), which is not recyclable at all and, in fact,

I agree that plastic is in most cases a better solution, however you are wrong to say the paper+PE board can't be recycled. Currently here in the UK they are not collected in household waste, but many businesses are recycling them and there is a lot of capacity available.

https://www.thegrocer.co.uk/news/ds-smith-makes-100-uk-coffe...

https://www.thefirstmile.co.uk/online-waste-services/busines...

Some of the issues are the collecting and sorting streams, then there are the commercial aspect of how to sell on the recycled material because it needs to be commercially viable.

> "Privatizing Profits and Socializing Losses"

The UK has recently introduced Extended Producer Responsibility for packaging legislation where the theory is the brand owner pays for the entire recycling and collection process of any packaging they put onto the market. Note this isn't just takeaway & food packaging, it's everything. The system though is an unworkable mess, it's so complicated trying to track every item of packaging and who is responsible for paying the tax down the entire supply chain.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#103

Post by Steve44 »

whywhywhywhy wrote: post #79
thrance wrote: post #51

Earlier quoted context omitted.

And Trump reverted the ban on plastic straws. One step forward, three steps backwards...

Always seemed like greenwashing to care about the straw in the drink that’s on a plastic cup with a plastic lid from the beans shipped in a plastic bag and render the experience of trying to drink it as tedious as possible.

I believe the issue with straws is they were hard to recycle because they were lightweight and often mingled with other materials, such as cups, napkins, and food waste.

They were generally made from PP which is widely recycled as a material.

They are also commonly littered and as they don't break down in the environment led the not only being unsightly but also clogging up waterways and direct damage to wildlife. Paper straws can still be littered, but break down so don't cause the same physical problems in the longer term.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#104

Post by Steve44 »

baranul wrote: post #31
kikokikokiko wrote: post #2

Well, they used a "simple, inexpensive catalyst" and then HEATED the plastic/catalyst mysture. Nowhere in the article it gives you an estimate of the final cost of the process.

Keep seeing these "possible breakthroughs" in breaking down plastic waste, but no concrete time frames on expanding to scale nor real world costs. Meanwhile, the mountains of plastic continues. Finding it also odd that biodegradable plastics and safer alternatives are going quiet. As if the new scheme is to keep fossil fuel companies rolling, with the promise that one day a solution to get rid of incalculable mountai…

> Finding it also odd that biodegradable plastics and safer alternatives are going quiet.

They tend not to be a good solution to anything.

There are a couple of ways of making degradable plastic. One is to add something to their manufacture so they break down into shorter chains which their supporters tell you will then further break down. These are generally referred to as OXO degradable.

Another is to use bio based plastics such as PLA or cellulose. These both have poor performance compares to oil based plastics.

All of these also require industrial composting where they add no nutrition to the compost, effectively just bulking it out. They [generally] do not break down when littered or even placed in a domestic compost heap.

There is also a problem because these plastics are virtually impossible to sort from recyclable plastics so if they get in each other waste stream the whole batch can be rendered contaminated and useless.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#105

Post by xnx »

djentile wrote: post #97
XorNot wrote: post #71

Earlier quoted context omitted.

Landfilling plastics avoids even putting CO2 back into the environment. Modern landfill is highly engineered and extremely stable: what goes in there stays there. Plastic starts as oil in the ground. Replacing it as solids in the ground isn't a problem.

Among other problems, plastics release methane and c02 as they decompose in landfills, so it's not as cut and dried a solution as you imply.

Modern landfills carefully channel and burn off the methane

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#106

Post by stubish »

projektfu wrote: post #6
kibibu wrote: post #5

Earlier quoted context omitted.

The journal article is open access. https://pubs.rsc.org/en/content/articlelanding/2025/gc/d4gc0... > Catalytic amounts of AC/MoO2 selectively convert waste PET into its monomer, terephthalic acid (TPA), within 4 h at 265 °C with yields as high as 94% under 1 atm air. I'm not a chemist so don't know if you can find a way to calculate the cost, but the authors claim that it's cheaper than current methods. The bigger d…

Yeah, these are pizza oven temperatures. The temperature appears to be just above the melting point for PET. It is also in the liquid phase for PBT, PEN and PEF. I think most recycling methods for PET require melting anyway.

Also manufacturing, so importantly this might be more energy efficient and maybe even cheaper than making new plastic. Depending on how the monomer->PET part gets solved.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#107

Post by 082349872349872 »

gsf_emergency_2 wrote: post #99
082349872349872 wrote: post #89

Earlier quoted context omitted.

looking at https://en.wikipedia.org/wiki/Volcanic_eruption#:~:text=Ther... suggests that if a goal is to avoid eruptions, low-water content golden rings would be preferable to the bags of mostly water that are live human beings.

Reminder: fast approaching era of {(precious metal) androids,(factory floor) lava} being a valid drop-in for {e-waste,recycling} Pulo ng suso ng dalaga https://youtu.be/uh4dTLJ9q9o https://en.wikipedia.org/wiki/Perhentian_Islands#:~:text=of%...

https://en.wikipedia.org/wiki/Mamucium#Etymology

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#108

Post by foxglacier »

baranul wrote: post #92
foxglacier wrote: post #81

Earlier quoted context omitted.

Incalculable mountains aren't a real environmental problem. People just believe that for some reason. We can just leave them there forever. The actual environmental value in recycling is reducing the CO2 emissions from making new plastic by reducing production of new plastic. I don't know if biodegradable plastic actually helps at all or just placates the people worried about the fake problem of incalculable mountain…

I'm not sure why you have the take that plastic pollution is not a problem. If anything, it is a massive catastrophe that threatens the environment and possibly the human race. Plastic pollution is destroying the environment[1], wildlife[2], and damaging humans[3][4]. That includes newborn babies[5]. [1] https://www.unep.org/plastic-pollution [2] https://www.biologicaldiversity.org/campaigns/ocean_plastics... [3] htt…

I'm talking about plastic waste in landfills ("mountains"). For that, recycling does no good because it's just as likely (or more?) to leak into the environment failing to reach a recycling facility as it is failing to reach a landfill.

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#109

Post by gsf_emergency_2 »

082349872349872 wrote: post #107
gsf_emergency_2 wrote: post #99

Earlier quoted context omitted.

Reminder: fast approaching era of {(precious metal) androids,(factory floor) lava} being a valid drop-in for {e-waste,recycling} Pulo ng suso ng dalaga https://youtu.be/uh4dTLJ9q9o https://en.wikipedia.org/wiki/Perhentian_Islands#:~:text=of%...

https://en.wikipedia.org/wiki/Mamucium#Etymology

Til: "pap"- early kiki/bouba, semantic shift

Triple point: Myanmar Memento mori 天命靡常

“刑天与帝至此争神，帝断其首，葬之常羊之山，乃以乳为目，以脐为口，操干戚以舞。”

Re: Scientists break down plastic using a simple, inexpensive catalyst and air

#110

Post by gsf_emergency_2 »

gsf_emergency_2 wrote: post #109
082349872349872 wrote: post #107

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/Mamucium#Etymology

Til: "pap"- early kiki/bouba, semantic shift Triple point: Myanmar Memento mori 天命靡常 “刑天与帝至此争神，帝断其首，葬之常羊之山，乃以乳为目，以脐为口，操干戚以舞。”

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

https://en.m.wiktionary.org/wiki/pap#Etymology_2

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