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Scientists create artificial protein that can degrade PET plastics in bottles

phys.org

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Re: Scientists create artificial protein that can degrade PET plastics in bottles

#71

Post by bee_rider »

yakubin wrote: post #66
bee_rider wrote: post #40

Earlier quoted context omitted.

It is sort of weird because people around the world are staving, while we have tons of food waste in the west. So there is in some sense a crisis and plastics are a tool that could be used to help solve it. But we don’t, instead we peel oranges and then sell them in plastic containers at the grocery store. If we were talking about making hard trade-offs between preservation required to save lives and reducing polluti…

> But we don’t, instead we peel oranges and then sell them in plastic containers at the grocery store. Someone is selling peeled oranges? O.o How long until they sell peeled apples?

Maybe not anymore, but Wholefoods gave it a try, there was a bit of mockery. In general I think the idea that our food is over-processed and over-packaged is not a new complaint, haha.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#72

Post by bobthepanda »

kragen wrote: post #68
CptFribble wrote: post #64

Another story about waste "solutions," another opportunity to remind the gentle readers about plasma gasification. A re-post of an earlier comment of mine on the topic follows: --- Why are we still not talking about plasma gasification? https://en.wikipedia.org/wiki/Plasma_gasification As far as I can tell, the only real "disadvantages" if you can call them that, are: 1. more expensive than throwing the garbage in a…

probably because landfills work fine if you aren't on an aircraft carrier. and they're cheaper. they're also rich veins of valuable minerals for the future, but that unfortunately doesn't figure into their present profitability

It's also mentioned that it's more expensive than normal incineration, and waste-to-energy gets you most of the way towards eliminating the worst parts of plastic waste if done right. It's very widespread in Japan and parts of Europe already.

Usually the issue with waste-to-energy is locating a facility, and I would imagine plasma gasification would run into similar NIMBY issues just because people don't like the idea of being next to a large intake facility of garbage, regardless of how bad it is in practice.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#73

Post by flavius29663 »

CptFribble wrote: post #64

Another story about waste "solutions," another opportunity to remind the gentle readers about plasma gasification. A re-post of an earlier comment of mine on the topic follows: --- Why are we still not talking about plasma gasification? https://en.wikipedia.org/wiki/Plasma_gasification As far as I can tell, the only real "disadvantages" if you can call them that, are: 1. more expensive than throwing the garbage in a…

I was always thinking, could we combine incineration + plasma gasification? What if we burn the garbage, which results in a lot of heat + clean + noxious gases, and then we just pass the gases through plasma? That should take care of anything that is dangerous in the emissions, but also make it more efficient, because a lot of the mass has already burned, plasma doesn't have to go through that much material anymore

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#75

Post by PaulDavisThe1st »

kragen wrote: post #69
01100011 wrote: post #65

Earlier quoted context omitted.

Does plasma gasification result in plastic monomers that can be used as building blocks for new polymers? If not, it seems like it is addressing a different need.

this novel process seems to produce carbon dioxide and water, not terephthalic acid

ah, CO2 ... we've been looking for a new source of this extremely rare material for some time now, I hear.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#76

Post by readyplayernull »

whatshisface wrote: post #62
lysozyme wrote: post #32

As cool as this is, the word “microplastics” is a little misleading. There are dozens of types of plastic in common use, each made from a different monomer with a different chemical linkage, of which PET is only one. The engineered protein in TFA will only work on PET and we’ll need to design new proteins for the other types of plastic. (I can help with that.) The problem with enzymes eating plastic is that enzymes a…

I don't really see why there is a problem with degrading whole bottles. If you have separated from the waste stream, you can incinerate or even landfill them (it's not like you'd be wasting any resources). It's the microplastics that form when the bottles are dumped into the oceans or waterways and broken up by Nature which need a novel solution for removal.

Plastic aren't simply plastics, they have lots of additives to give them different properties. Incinerating is transforming these additives into other chemicals maybe making more toxic molecules escape to the environment in ashes, dust, smoke. And landfilling is storing trash for future generations to solve the problem.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#77

Post by KennyBlanken »

zackmorris wrote: post #50

I'd like to know who originally put incompatible types of plastic under the same number, which contaminates recycling runs. Like PET/PETE under "1" and injection-molded/blow-molded HDPE under "2": https://www.warwickri.gov/sanitation-recycling/faq/why-cant-... Many cities have banned recycling the most commonly used plastics, like plastic water bottles made of 1 (PET). Where I live, 1 and 2 get recycled, 3 (PVC) gets…

Plastic recycling was a sham, and still is; it's never been economically viable and never will be, because the polymer degrades, permanently, as part of production, use, and aging.

It's window-dressing so the industry can shift attention away from limiting production of something that shouldn't see anywhere near the widespread use it does.

The same is true of the stories you see all the time about some group or person doing a beach cleanup. It casts the problem as the fault of people dumping the stuff, while pretending like it's a solvable problem, if only we had enough people rummaging around cleaning up beaches, parks, ocean bays, fields, hiking trails, abandoned properties, etc.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#79

Post by nihzm »

whatshisface wrote: post #62
lysozyme wrote: post #32

As cool as this is, the word “microplastics” is a little misleading. There are dozens of types of plastic in common use, each made from a different monomer with a different chemical linkage, of which PET is only one. The engineered protein in TFA will only work on PET and we’ll need to design new proteins for the other types of plastic. (I can help with that.) The problem with enzymes eating plastic is that enzymes a…

I don't really see why there is a problem with degrading whole bottles. If you have separated from the waste stream, you can incinerate or even landfill them (it's not like you'd be wasting any resources). It's the microplastics that form when the bottles are dumped into the oceans or waterways and broken up by Nature which need a novel solution for removal.

I think what lysozyme said holds even if you do not consider "whole" bottles at all. According to wikipedia the biggest microplastics are 5mm, whereas the enzyme is 10nm, that is 5 orders of magnitude of difference, but just in lenght! To process the entire volume you need to cube the units and you get 15 orders of magnitude in difference (1 mm^3 to 10 nm^3).

To get an idea I asked wolfram alpha what is the volume of the average human, and apparently that is around 66 liters. Then I looked up the estimated water volume of the Baltic sea, and wikipedia says it is 21,700 km^3 of water, soo

    $ units
    586 units, 56 prefixes
    You have: 21.7E3 km3
    You want: 66 liters
        * 3.2878788e+14
        / 3.0414747e-15
if you could somehow fill your entire body with water, then make 30 copies of yourself, and you (30 of you) drink an entire Baltic sea (one for each), that is a very very rough analogy of the task we are giving to that poor enzyme. And this is for a single speck of microplastic! Of course the enzyme is not alone, there are a few other billions (trillions?) others with it, but there are also a few million specks of microplastic at any point in the sea. This is a very difficult task.

Re: Scientists create artificial protein that can degrade PET plastics in bottles

#80

Post by thomastjeffery »

lysozyme wrote: post #32

As cool as this is, the word “microplastics” is a little misleading. There are dozens of types of plastic in common use, each made from a different monomer with a different chemical linkage, of which PET is only one. The engineered protein in TFA will only work on PET and we’ll need to design new proteins for the other types of plastic. (I can help with that.) The problem with enzymes eating plastic is that enzymes a…

Looks like the title was edited to accommodate your clarification.

Unfortunately, that makes your comment a bit confusing, since the context of the title change is not present. I think the best solution would have been the title, "Scientists create artificial protein capable of degrading [PET] microplastics in bottles".

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