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New catalytic process turns plastic bags into adhesives:
While many cities and eight states have banned single-use plastics, bags and other polyethylene packaging still clog landfills and pollute rivers and oceans.
One major problem with recycling polyethylene, which makes up one-third of all plastic production worldwide, is economic: Recycled bags end up in low-value products, such as decks and construction material, providing little incentive to reuse the waste.
A new chemical process developed at the University of California, Berkeley, converts polyethylene plastic into a strong and more valuable adhesive and could change that calculus.
"The vision is that you would take a plastic bag that is of no value, and instead of throwing it away, where it ends up in a landfill, you would turn it into something of high value," said John Hartwig, the Henry Rapoport Chair in Organic Chemistry at UC Berkeley and leader of the research team. "You couldn't take all of this recycled plastic—hundreds of billions of pounds of polyethylene are produced each year—and turn it into a material with adhesive properties, but if you take some fraction of that and turn it into something that is of high value, that can change the economics of turning the rest of it into something that is of lower value."
Journal Reference:
Liye Chen, Katerina G. Malollari. Selective, Catalytic Oxidations of C–H Bonds in Polyethylenes Produce Functional Materials with Enhanced Adhesion, Chem (DOI: 10.1016/j.chempr.2020.11.020)
(Score: 3, Insightful) by KritonK on Monday December 21 2020, @02:04PM (9 children)
So, if we convert those hundreds of billions of pounds of polyethylene, that are produced each year, into adhesives, is there a need for so much glue, and how do we recycle that, once the glued parts have outlived their usefulness?
Presumably the adhesives aren't biodegradable, as this would defeat the purpose of an adhesive, so this is merely postponing the inevitable, and the converted polyethylene will eventually end up in a landfill anyway.
(Score: 5, Insightful) by Immerman on Monday December 21 2020, @02:21PM (7 children)
I imagine there's a fair chance that if you use the adhesive to assemble polyethylene products it could be recycled again.
But the landfill has always been the final destination of any plastic product - the whole "recyclable plastic" idea was always a marketing gimmick by the plastic companies to convince an increasingly environmentally conscious public that they shouldn't abandon their inherently high-pollution product. It's always been a best case scenario of one or two reuses before the quality has degraded so far it's not useful for anything but fuel.
The only truly recyclable plastic I've heard of is that acid-soluble monomer stuff that was in the news... last year? Dissolve it, separate the monomers from the additives, and reuse them in new plastic of comparable quality to the original. But as I recall it's considerably more expensive than current plastics, so unless we add a huge pollution tax to non-recyclable plastics it's unlikely to ever get off the ground.
(Score: 2) by HiThere on Monday December 21 2020, @04:07PM
There's a real problem here. We also don't want that carbon that those plastics hold to end up in the atmosphere. Burying it is really the only proper solution...and that should really be put "re-burying", since it was buried long ago. Just when and how depends on whether it was for oil or coal.
I suppose turning it into graphite or diamond would also work, but that's energetically expensive.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by Grishnakh on Monday December 21 2020, @05:15PM (4 children)
But the landfill has always been the final destination of any plastic product - the whole "recyclable plastic" idea was always a marketing gimmick by the plastic companies to convince an increasingly environmentally conscious public that they shouldn't abandon their inherently high-pollution product. It's always been a best case scenario of one or two reuses before the quality has degraded so far it's not useful for anything but fuel.
I don't see why it has to be this way. Plastic is nothing more than hydrocarbon chains: it should be infinitely recyclable, just like steel and aluminum are. The limiter, of course, is the amount of energy needed to convert it into something useful. But I don't see why it shouldn't be possible to continuously recycle plastic into other forms of plastic, merely by breaking it down into its constituent hydrocarbons and reforming it into the desired polymer type. Without recycling, we do this by taking crude oil fractions and using chemical processes to convert them into the desired polymers; why would it be so difficult to do this with plastics, which are already refined?
And what do you mean by "degraded"? With recycling, it's not possible for something to "degrade" too much: you're just going to break it down into its basic components anyway. Maybe you're thinking of "reuse".
As for "pollution", plastic doesn't cause air pollution generally. The only reason it's "pollutiing" is because we as a society do a poor job of cleaning up after ourselves, and taking these used plastics and putting them where they belong.
The root of the problem is that the true cost of plastic to society isn't being added to the price of things made with it: a "plastic tax" should be instituted (as you mentioned), which would then be used to fund recycling operations. Recycling isn't economic simply because the things it can be recycled into generally are low-value (and we don't properly assess the cost to society of just using virgin crude oil), but that doesn't mean it's zero-value: it's much better to recycle plastics into plastic lumber than to burn it or toss it in the landfill. As plastic lumber or some other similar low-value application, it's still performing a useful job, it's probably taking the place of some other thing that's environmentally worse (like using tree lumber, which generally doesn't last that long and involves clear-cutting forests), and it's keeping a lot of carbon sequestered somewhere, which is good for mitigating global warming.
(Score: 3, Informative) by VLM on Monday December 21 2020, @09:20PM (2 children)
Its a good idea but our best pigments and dyes are organic compounds of the same caliber and, frankly, source, as the bulk monomers, so stuff that destroys pigments and dyes will ruin the monomer pretty well too. I suppose you could make colored plastics illegal to ease recycling or tax the unholy F out of dyes and pigments but slapping epoxy paint on plastic parts would make them look almost as good while still Fing up the recycling.
You can paint steel and then recycle the steel because liquid steel temp turns the paint into air pollution and you get clean beautiful recycled steel. Not so easy to recycle the paint LOL. But if you try something like distillation with plastic parts you get something like a dumpster fire instead of a bucket of reusable pigment and a bucket of reusable monomer.
Also some polymerizing catalysts are very efficient and about as stable and complicated as the monomer, so its hard to get rid of them.
Its like its easy to strip the plastic bucket from the lead plates in an old fashioned car battery, but really hard to separate the two parts of epoxy after they're mixed together and react.
Maybe one way to put it is small-ish hydrocarbons are too versatile for their own good so you can't recycle the plastic from the catalyst from the glue from the dye from the mold release from the ...
Polymers are almost exactly like cooking and its hard to turn pancakes back into eggs and flour. Other than you shouldn't eat polymers generally, the analogy is so good that polymer chemistry really is cooking. You can turn pancakes into something like charcoal briquettes or outright burn them or turn them into maybe fake wood logs or lightly recycle into "pigs in a blanket" but you really can't turn them back into flour and eggs or even back into batter. Sadly, plastics are like cooking. Interesting thing to think about: If we (generally) could not eat gluten, development of gluten in bread dough is pretty much plastic manufacturing; like 98% of the population can eat one plastic, which is modified gluten in bread dough.
(Score: 2) by Grishnakh on Monday December 21 2020, @10:10PM (1 child)
Ok, obviously I'm not a chemist here, so bear with me, but plastics generally come from crude oil distillation, right? So I'm not sure the flour and eggs analogy works here. Shouldn't it be possible somehow to break down plastics (even with dyes, which you said are organic compounds, which again means hydrocarbons) back into a hydrocarbon soup, that you could then turn back into other plastics instead of having to use more crude oil? I'm just not understanding why there isn't a way to do this. It might need to be done in some kind of airtight furnace to avoid air pollution and so vaporized compounds can be captured and reused, but isn't this how oil refineries already work? Again, obviously I'm no chemist or petroleum engineer. It just seems like when you have a pile of used plastics, which are nothing but complex hydrocarbon polymers, it should be possible to turn this back into some kind of crude hydrocarbon, rather than going to some other part of the planet with political turmoil and pump a crude hydrocarbon out of the ground there. Perhaps bacteria?
(Score: 2) by Immerman on Tuesday December 22 2020, @04:07AM
VLM hit the nail on the head. You've got a whole lot of complex chemistry going in on the plastic making process - it's not just "frozen" petroleum distillates. Unlike something like iron, which *is* just frozen molten iron.
Yes, with enough effort you probably could turn plastics back into something closely the original hydrocarbon feedstock - just as you could turn pancakes back into flour and eggs. The problem is that doing so is vastly more expensive than just buying more fresh feedstock on the open market. And nobody is going to buy recycled plastic feedstock that costs 10x as much as fresh feedstock. And if nobody will buy it, nobody will make it.
(Score: 3, Interesting) by Immerman on Tuesday December 22 2020, @03:54AM
There's really two problems -
1) virtually all plastic is essentially an "alloy" of raw plastic and vaious additives to make it stronger, colorful, more flexible, or, or, or... And when you re-heat it those additives react with the raw plastic to create all sorts of complex organic molecules that weren't in the original plastic, and alter its properties. Even without the additives, the polymer chains themselves will tend to break down or cross-link in ways that change the plastic's properties. Hydrocarbon chains are not particularly stable, and have no "baseline" configuration they revert to when heated - unlike something like steel which reverts to a simple mon-atomic liquid when heated, and can even often be "de-alloyed" relatively simply by very slowly melting or cooling it so that the alloyed "impurities" separate out from the bulk material.
2) In order to recycle plastic into anything better that the plastic equivalent of low-grade "pot metal" - which is basically useless, you have to completely sort the plastic by type - mix two different types of plastic together, and you get something almost completely useless (ever seen those park benches made from crappy plastic 2x4s that are way weaker than you'd expect? That's about the only sort of thing you can do with unsorted plastic, and there's just not that much demand for that.). There's a few kinds of plastic actually worth sorting - clear plastic beverage bottles are a big one - they're easy to sort automatically, with few additives, and can be recycled into relatively high-grade plastic. The vast bulk though is relatively low grade plastic to begin with, and all but impossible to sort except by hand. For a while wages were low enough in China that they could sort it by hand there and generate useful recycled plastic that was just barely cheaper than freshly made plastic of comparable quality, but even then they left behind a whole lot of waste that wasn't worth recycling at all, until eventually China decided that dealing with the waste was costing their economy more than the tiny profit from recycling was bringing in, and banned the import of plastic waste.
At the end of the day recycling is governed by economics - the only way it's going to happen is if the recycled material can be sold at a profit, for less than the price of new material. And most plastic just can't be. Unlike metals which take a great deal of and energy and effort to mine and refine in the first place, and are easy to sort and recycle, plastics are cheap and easy to make fresh, and a horrendously difficult to sort and recycle.
(Score: 1) by khallow on Monday December 21 2020, @08:24PM
The real reason it's a gimmick is that recycling efforts expend considerable resources, particularly peoples' time, to recycle low value plastic.
(Score: 0) by Anonymous Coward on Monday December 21 2020, @06:27PM
It's good for an office gag. Right now, when the office quieting down for x-mas and covid, sneak in and fill the whole damn office with plastic glue. Think of the laughs! It's going to take quite a lot of glue to fill most of the offices in the world.
(Score: 0) by Anonymous Coward on Monday December 21 2020, @02:29PM (11 children)
Put the plastics in an incinerator and possibly make some electricity off it.
(Score: 0) by Anonymous Coward on Monday December 21 2020, @02:57PM (1 child)
Smells great!
NIMBY!
Bury that crap. It came out of the ground; put it back.
Maybe use it for fracking.
(Score: 0) by Anonymous Coward on Monday December 21 2020, @03:22PM
Bury crap that can't be economically turned into anything else.
Plastic burns hotter than hell. Make some electricity off it (with pollution controls, of course.) Conserve existing landfill space.
(Score: 2, Insightful) by Anonymous Coward on Monday December 21 2020, @04:33PM (8 children)
Add the Greenhouse gasses! Kill everyone faster.
Stop pumping oil from ground. The Earth already sequestered the carbon, multiple, multiple years a go. It was great when... like with xrays in shoe box or old dentists... until we understood the cost.
Adhesives is not solution either. At best used in the building trade to make engineered beams... but those in 50 years are back in the land fill, since they cannot be mulched.
The only solution is not do it in the first place. Build a true recycling system - like with GLASS Coke bottles - those were recycled and reused over and over. When broken could be converted back to glass again reused again and again.
Simplest: The cost to "DISCARD" the item is built into the COST of buying the item. Discard means recycle or landfill or burning. This is the full cost to planet.
Cost you pay will depend WHERE YOU LIVE, added costs are built into middle men collecting, so the cost is already in there the local store cannot decided to not charge it. Like gasoline and cigarette taxes. So you live more then 60 miles from a closes recycling point for that item, then you pay highest cost and maybe even be illegal to own/receive in the first place. YES, will create "deserts", but also force the recycling industry to get there.
MAybe even force the stores that sold the item, to take it back and recycle it. Again forcing the supply chain to cleanup their mess.
Cost is also based on the totality of the item. Say LI-ON battery is glued into the cellphone and there is nowhere to recycle it. The CELLPHONE could be illegal or massive more expensive to own then. -- this make manufactures responcible for the end-of-life of product. Include earbuds, medical devices, and so on.
The amount paided is for 3 descutctionmethods are true cost of recycling, Fill and Buring would be multiple times more than recycling. say 10x to 100x, for the HOLD ITEM even it is just one small part that cannot be recycled. This will insentive manfactures (or importer) to correctly source the items they are selling and help build the infractsture to really do the recycling.
Means for foods like milk, back to at least paperboard cartons over plastic. Maybe even glass bottles again. Papaer bags agian. and so on. At least these paper items can be muluched so even works in "derset" areas, since you can mulch at home.
Means for electronics, ways to sperate all the pats out. Evens means right to repair could be supported. Think Ilike in-line chips for the 70's and 80's that were sockets vs soldered on. Then the cip could be pulled and replaced, motherboard could go a different way. Sinc ethey seperatable, they could be treated as two items vs just one. Like in a tablet or low end computer of today.
Again not a full list, but if we do not start to get it really right then we are dead.
(Score: 2) by Grishnakh on Monday December 21 2020, @05:23PM (2 children)
Think Ilike in-line chips for the 70's and 80's that were sockets vs soldered on. Then the cip could be pulled and replaced
There were two reasons they stopped socketing chips like that. One of course was cost: the socket itself cost money, plus the extra labor to insert the component. The other was reliability: socketed transistors and ICs frequently didn't work that well, and a common repair method was to remove and re-seat those parts. Over time, corrosion would build up on the contacts inside the socket, and re-seating would scrape it off. Simply soldering the part into the PCB eliminated this source of long-term unreliability.
Anyway, there's simply no way electronics could go back to anything like this: the density is much too high. The amount of PCB real estate needed for a little 14-pin DIP can now be filled with a BGA with *hundreds* of connections.
To recycle stuff like this, someone needs to develop industrial methods that involve grinding up all the electronic parts and then separating all the elements somehow, similar to how metals are recycled now.
Build a true recycling system - like with GLASS Coke bottles - those were recycled and reused over and over.
Glass does have a huge advantage in recyclability, however it also has a large energy cost: it costs a lot more to transport it, because it weighs so much (though they've developed stronger glasses now that can be made thinner, which helps some) more than plastic, and also the amount of energy needed to melt glass is very high, much higher than plastic.
(Score: 0) by Anonymous Coward on Monday December 21 2020, @09:09PM
Our recycling stopped taking glass. Nobody wants it when virgin sand to make new glass is so cheap and of known better quality. Glass is in actuality a very low value good for recycling. It makes no sense. It MIGHT make sense to REUSE glass; I don't know.
The only thing I know of that always made sense to recycle is metals.
(Score: 0) by Anonymous Coward on Tuesday December 22 2020, @04:21AM
Still looking back to explain why it can’t be done
Look forward. Yes inline dips had issues. Learn from it! High end pc and servers normally have replaceable chip in pin housings. If it is so bad why do it for $2000+ chips. Video cards. Main frames?
What you only learned was cheap designs sucked. So only make cheap crap with solder. And toss in trash.
The point was to push the cost of equipment retirement back on the manufacturing. So quick cheap solutions the only can fill the trash cans with material that should not be there in the first place. Make parts replaceable so items have longer lifes. Also would allow for parts to be delegated aplaced into correct recycle streams with and quaility material coming out.
Glass transport cost again tossed in is another example of failing in learning Glass bottle reuse was done for decades. So old tech worked well. But there is no need to Say “we can’t because of energy cost”. Electric with wind or solar makes some of that go away. What really killed the bottle reuse was supermarkets did not want the used bottles back. And the manufacturer did not want the handling cost. So ship it to the land fill problem solved.
So please learn whys and how to make it is better. Than learning the wrong short term thinking
(Score: 1) by khallow on Monday December 21 2020, @08:26PM (4 children)
50 years is a long time to be kept out of a landfill. If landfill space really were as costly as advertised, this wouldn't be a bad deal.
(Score: 0) by Anonymous Coward on Tuesday December 22 2020, @03:56AM (3 children)
Only from a short term view. Delaying for 50yrs is same as dumping it in today. Look at high rise that is a trash pile since it is too hard to unbuild
(Score: 1) by khallow on Tuesday December 22 2020, @04:08AM (2 children)
Just like dying today is the same as dying 50 years from now?
(Score: 0) by Anonymous Coward on Tuesday December 22 2020, @04:25AM (1 child)
Resorting to pathos means you've run out of argument. Why don't you try again?
(Score: 1) by khallow on Friday December 25 2020, @10:01PM
Which didn't happen here. My point is that if there's value or cost to some action or event, then when it happens becomes important. Putting costs off for a time (all else being equal) means they effective cost less. Bringing benefits up to the present means that they effectively are worth more. Getting some benefit today is more valuable than getting it 50 years from now. Similarly, paying some cost today is more costly than paying the same cost 50 years from now.
Death now versus later is an extreme example which illustrates a lot of the problems with the idea that "when" on that scale is irrelevant. The only way it could possibly not matter to you whether you die now or 50 years from now, if your life has zero net value to you. Similarly, the only way that recycling plastics into adhesives that keep material out of landfills for 50 years is if that activity has zero net value for you. You already imply otherwise.
Rereading your earlier post (presumably), I see also the following:
It's not that hard. Controlled demolition [wikipedia.org] is a thing even in crowded city centers where the difficulty, risk, and cost of bringing down high rises is more than matched by the value of what replaces them. But even if we're in a situation where a building isn't worth using or scrapping (say one of the many abandoned buildings in Detroit), we can just leave it there. So what if it's a trash pile?
(Score: 2) by Tokolosh on Monday December 21 2020, @02:55PM (7 children)
There is nothing wrong with landfilling waste. It is usually the most cost-effective solution with the least overall environmental impact. This has become the truth that cannot be whispered.
(Score: 4, Insightful) by Grishnakh on Monday December 21 2020, @10:14PM (6 children)
There is something wrong with it: it takes up space. It costs real money to truck garbage to a landfill that's perhaps hundreds of miles away, because no one wants it in their back yard. And landfills get filled up all the time, forcing them to close, and for municipalities to have to truck their waste even farther away, which costs even more money. At some point, recycling parts of the waste stream becomes more economical than costly transport of garbage. For a while, we offloaded some of this cost on the Chinese by filling up empty shipping containers with recyclables (usually of poor quality and contaminated, such as used pizza boxes) and shipping them back to China on the container boats that had brought manufactured goods to us, but now China doesn't want our trash so we're being forced to deal with it ourselves, and we're finding we're ill-equipped to do so.
Your "just landfill it" suggestion would work great if we passed a low forbidding any municipality from denying a permit to build a landfill anywhere, even if it's right next to a subdivision or school or ritzy shopping area.
(Score: 2) by Tokolosh on Tuesday December 22 2020, @01:20AM (5 children)
You are wrong on many counts, mostly because your assumptions are incorrect. I shall only bother with one. "At some point, recycling parts of the waste stream becomes more economical than costly transport of garbage." If this is the case, why do we need laws forcing us into recycling? Note that I do not deny that some things are worth recycling.
(Score: 3, Insightful) by Grishnakh on Tuesday December 22 2020, @01:35AM (4 children)
If this is the case, why do we need laws forcing us into recycling
That's pretty easy: because it's usually not more economical. It's only in some places at some times the equations change, and for certain materials. If there's a landfill next door, then it's probably rarely economical to recycle anything besides aluminum. If the landfill is in another state, this changes.
Anyway, the big problem is that costs are externalized: products don't force consumers to pay the full price of disposal, so that gets added to everyone's taxes (usually property taxes, because the municipalities are stuck with the problem), nor are environmental effects factored into the price. Unfortunately, the "free market!!!" types are always in favor of socializing costs like this instead of requiring businesses to pay them.
(Score: 1, Insightful) by Anonymous Coward on Tuesday December 22 2020, @02:04AM (3 children)
You have zero understanding of economics.
Centrally planned economies where the govt fixes prices arbitrarily (i.e., by fiat) such as you are suggesting always end in shortages, waste, poverty, and overthrow of the govt.
(Score: 3, Insightful) by Immerman on Tuesday December 22 2020, @04:01AM (2 children)
There's no need for centrally managed price fixing - you could just say "it will cost $X to deal with the disposal of a widget", and impose an $X widget tax to cover the inevitable disposal costs. Just like that the customer is paying for the disposal cost up front, rather than having the cost be externalized onto society at large.
The problem is that widget makers are going to be strongly opposed to such a plan, and since lobbying isn't treated as treason, are very likely to successfully pressure politicians to avoid such an option.
(Score: 1, Insightful) by Anonymous Coward on Tuesday December 22 2020, @05:03PM (1 child)
What you just suggested is the govt fixing the price of the good.
How does the govt know what it will cost to "recycle" the good? Who recycles the good? How are they paid, from the recycling tax? Does this mean all recyclers work for the govt? You are injecting huge and rigid inefficiency in this process with added cost to the taxpayer with no guarantee that the "recycling" actually will happen. People might get paid just to put it in a landfill. The truth is that most things are not recyclable. Those that are, people will buy from you as scrap. You don't have to pay them. The biggest answer is to reduce production of waste in the first place. Unfortunately, economics seems to encourage production of cheap trash.
(Score: 2) by Immerman on Tuesday December 22 2020, @09:11PM
No, government fixing the price of the good is wehen they say "this good must be sold for $X"
Government taxation is when they say "You must pay us $X when you sell this good" How much more than $X you charge is completely up to you and what the market will bear.
Yes, they are setting the price of recycling, and yes, they would have to pay the recyclers, and we would have to hold them accountable - they are our employees after all.
The alternative is that the good WILL NOT be recycled because recycling is more expensive than getting fresh material. That's not speculation - that's what's been happening with plastic from the beginning. A small fraction of the highest value stuff was recycled, but even with poverty wages in China they couldn't recycle most of it cheaply enough for anyone to buy it.