How long can plastic be recycled?

[odysseus2000]

It has interested me for a while as to whether there are fundamental, not economic, limits to the amount that plastic can be recycled.

From my relatively limited knowledge of chemistry I can't see any theoretical reason why it is not possible, if cost is not a consideration, to recycle the atoms in plastic indefinitely.

However, plenty of folk argue that there are fundamental limits to how much recycling is possible and that eventually humanity will need every molecule of hydrocarbon on earth. Charlie Munger made this argument at the last Berkshire meeting.

If I am wrong, what would make the recycling of atoms in plastic have a finite limit?

Regards,

[PeterGray]

If you are talking about recycling at the level of atoms - then the costs, in terms of plant and energy become seriously limiting, whatever the theoretical practicalities.

[tjh290633]

It all depends on how you are recycling it. If you are trying to recycle it as the same product that it was initially, then I would have thought very little. However most of the recycling that I have heard of involves operations like melt spinning into insulation wool or moulding into pallets.

If you are thinking of taking PET bottles and making them back into more PET bottles, then that is a different matter. You can only do it by mixing the recycled PET with virgin PET, possibly at a low percentage of recycled product. Colour is also a factor, green, brown and clear probably not being compatible.

The glass industry knows all about recycling, where virtually all the green glass is made from recycled material, because the number of imported wine in bottles is more than enough to satisfy domestic demand. You have to add a small amount of additives to ensure that the melting process proceeds as required. Amber glass and clear glass are not compatible, because amber is made under reducing conditions and clear glass under oxidizing conditions. The amber colour is caused by a complex of iron and sulphur, and that requires reducing conditions to produce it. You need some sulphur in clear glass, but as sulphate rather than sulphide, and this helps the melting process. If you move the oxygen partial pressure down, the solublity of sulphur dioxide falls, which can lead to a lot of foam and big problems. Eventually you get into the sulphide region. Typically the amount of recycled glass can range up to 50% if it is available and suitable.

TJH

[odysseus2000]

tjh
The glass industry knows all about recycling, where virtually all the green glass is made from recycled material, because the number of imported wine in bottles is more than enough to satisfy domestic demand. You have to add a small amount of additives to ensure that the melting process proceeds as required. Amber glass and clear glass are not compatible, because amber is made under reducing conditions and clear glass under oxidizing conditions. The amber colour is caused by a complex of iron and sulphur, and that requires reducing conditions to produce it. You need some sulphur in clear glass, but as sulphate rather than sulphide, and this helps the melting process. If you move the oxygen partial pressure down, the solublity of sulphur dioxide falls, which can lead to a lot of foam and big problems. Eventually you get into the sulphide region. Typically the amount of recycled glass can range up to 50% if it is available and suitable.

Yes, this I understand.

But, again assuming cost isn't considered, could one e.g. Create an ion source or plasma & extract e.g. Atoms of Iron, sulphur etc by techniques such as mass spectrometry?

There are proceedures e.g. for creating pure elements of all the species of the periodic table so could one not do something similar if one wanted to?

For hydrocarbons, it seems to my ignorant mind, that separation ought to be easier as one is dealing with relatively small numbers of elements: hydrogen, carbon, oxygen predominantly.

However, many folk argue it is impossible even before the costs are considered.

I am interested as recycling has the potential to become a huge industry. Not so long ago I was told that electronics can not be recycled, but Apple are now routinely doing it with their iPhones & are talking about reaching a situation where they would no longer need extractive industry raw materials.

All the technology I know of makes this kind of idea too costly, but having thought of what is involved I begin to wonder if some new methods of extraction have emerged that may be cost effective.

The historical precedence for norms being over turned is high. While doing my physics degrees I was told several times that solar was totally impractical in the UK, but now there are countless UK houses happily creating photovoltalic power, ditto for wind & wave. Meanwhile the nuclear industry which I was told would power the 21st century is declinining in many countries.

The wold is endlessly changing and using resources wisely seems to me to be a big investment opportunity going forwards.

Regards,

[dspp]

The price (or cost) of energy probably sets the economic bound for most recycling operations, and most other industrial processes.

When EROEI for shale oils is at parity (which it seems to be there or thereabouts) that indicates that the floor medium term oil price is likely to be about $50/bbl. Since renewables is able to achieve that price and is trending downwards, any recycling that is viable at $50/bbl without subsidy would seem to have a longish future.

regards, dspp

[tjh290633]

But, again assuming cost isn't considered, could one e.g. Create an ion source or plasma & extract e.g. Atoms of Iron, sulphur etc by techniques such as mass spectrometry?

There are proceedures e.g. for creating pure elements of all the species of the periodic table so could one not do something similar if one wanted to?

For hydrocarbons, it seems to my ignorant mind, that separation ought to be easier as one is dealing with relatively small numbers of elements: hydrogen, carbon, oxygen predominantly.

However, many folk argue it is impossible even before the costs are considered.

They are not just hydrocarbons. PET, polyethylene terephthalate for example is a polymerised ester of ethylene glycol and terephthalic acid. The process is not reversible. There may also be other compounds in the polymer to improve its properties or processability. Nylon6 is polymerised caprolactam.

If you heat polymers up they tend to decompose and volatilise, but the volatile components are not of any practical use, except as a fuel source, so they are best incinerated to generate energy in some form or other. Some compounds will give a usable liquid fuel, but there are easier ways of getting that. PVC or PTFE are likely to give you chlorine or fluorine either as the element or as a corrosive compound when pyrolysed.

Mass spectrometry is a tool for analysing materials. Except in very small amounts, separation of a substance into its constituent elements is not a practical proposition.

TJH

[odysseus2000]

Hi TJH,

Good points, so either one needs some new method or new materials or some development that e.g. de-polymerises polymers or otherwise breaks plastics etc back into some form that can be used to fabricate new products rather than just as a fuel or other low value product.

Has there been any progress in reversing what you show as being irreversible processes?

On the Apple web page: https://www.apple.com/environment/

They state:

Can we one day stop mining the earth altogether?
It sounds crazy, but we’re working on it. We’re moving toward a closed-loop supply chain. One day we’d like to be able to build new products with just recycled materials, including your old products.

Assuming there is some substance behind this and with most Apple products having at least some kind of plastic in them they must have some ideas for believing that materials can be used and re-used again.

If one thinks of the tools developed to do the difficult job of separating fissile Uranium 235 from stable and non-fissile Uranium 238, one of which was electromagnetic (later abandoned due to cost), the challenges of separating atoms or molecules of relatively much larger mass differences does not seem so impossible and if Apple are to live up to their ideas of closed loop supply chains will I assume have to be done. Unless there are new materials that they intend to use.

Regards,

[PeterGray]

It all depends on how you are recycling it. If you are trying to recycle it as the same product that it was initially, then I would have thought very little

My post was a response to the query
If I am wrong, what would make the recycling of atoms in plastic have a finite limit?

so I was talking about recycling at the atomic level. There is theoretically no finite limit on how many time you can recycle the atoms in plastic - but to do it at that level, if you needed to, would involve breaking the molecular structure down and reconstituting it - something which is going to be energetically and capitally impractical in most cases.

Recycling works where you can reuse or recycle using far simpler and cheaper techniques - and as you say in some cases where you are recycling as the same product it my be very little. Though that doesn't apply to all plastics.

I suspect that the technological key to maximising plastic recycling is in the development and use of plastics that are designed to be easily and cheaply recycled.

Peter

[odysseus2000]

Recycling of gold & heavy metals with robotic breaking of iPhone 6 has to lead to substantial recovery of most heavy metals. See & scroll down:

https://www.apple.com/uk/environment/resources/

The question which interested me was whether the claims of wanting to extend recycling to the point where there was no need for extractive industries was also likely possible with plastics.

On this page, scroll down,:

https://www.apple.com/uk/environment/safer-materials/


they state that plastics like pvc & phthalates have been replaced in most markets by thermoplastic elastomers.

These materials are according to my research are recyclable:

http://www.bpf.co.uk/plastipedia/polyme ... omers.aspx

TPE processing scrap, reject parts or end of life products can be easily reprocessed, whereas most thermosetting elastomers end up as land fill.

Additional advantages over thermoset rubber provided by TPEs include excellent colourability and a lower density.

So as far as I can tell the statements about moving away from extractive industries are potentially correct & as Peter just posted, currently this will be achieved by using easier recyclable plastics, than more sophisticated recycling of difficult plastic materials.

Apple currently seems to be leading this field, but it seems likely that cost pressures and/or politicians will force other purveyors of electronics to adopt similar technologies & it seems likely, at least to me, that new industries will form to make this kind of recycling the norm. The economic case for controlling ones own raw materials and becoming independent of commodity pricing, irrespective of environmental pressures, seem such a strong case as to quickly make such recycling the norm.

The issue from an investment perspective is more likely who will control this business and how will such moves affect the extractive industries. One has already seen coal decline dramatically, might one also see the miners of other materials also suffer?

Regards,

[tjh290633]

There was an article in Chemistry World in either March or April, on the subject of "mining" for valuable elements in redundant electronic devices like smartphones.

It may not be available to nonmembers of the Royal Society of Chemistry, and I can't post a link from my phone, but it is worth reading if you can find it. Unfortunately my copy has already been recycled.

TJH

[tjh290633]

If anybody can get in, the link is https://www.chemistryworld.com/feature/ ... 97.article and the introduction says:

Although smartphones contain a host of valuable metals, getting at them is the tricky bit. Emma Davies reports

Most of us have a growing collection of unused mobile phones secreted in a drawer, tied to us by threads of nostalgia or the barriers to recycling electronic goods. Unlike redundant washing machines or television sets, they are small enough to hide and forget. This poses a headache for recyclers keen to recover the host of valuable metals locked inside.

Each phone contains as many as 60 elements, from the thin, conductive later of indium tin oxide on a smartphone’s screen to the lithium in the batteries. As with all electronics, a phone’s micro-electrical components and wiring mainly comprise copper, gold and silver, while tantalum is used in microcapacitors. Elsewhere in the phone, neodymium–iron–boron magnets are commonly used in microphones, speakers and vibration units. Phone composition has changed little over the years, save for increasing levels of indium tin oxide with soaring smartphone demand.

The date is 20 March 2017, so presumably the April issue.

TJH

[odysseus2000]

tjh


Each phone contains as many as 60 elements, from the thin, conductive later of indium tin oxide on a smartphone’s screen to the lithium in the batteries. As with all electronics, a phone’s micro-electrical components and wiring mainly comprise copper, gold and silver, while tantalum is used in microcapacitors. Elsewhere in the phone, neodymium–iron–boron magnets are commonly used in microphones, speakers and vibration units. Phone composition has changed little over the years, save for increasing levels of indium tin oxide with soaring smartphone demand.

This, I think, illustrates how revolutionary Apple's approach to recycling is.

Going from some hodgepodge of things put together with no thought about recovering the expensive elements, to Apple approach of building in a way to dismantle & recover all the precious & expensive stuff.

The commercial advantages of paying only for the expensive stuff once & then reusing it are substantial.

The more I think about it, the more ridiculous it is to landfill stuff that is expensive & then has to be replaced. This model of course works if the commodities are inexpensive & landfill also inexpensive, but for many of the things that go into a smart phone, the opposite is true. A business that is continually having to buy in new commodities & pay land fill costs is at a big disadvantage to one that has neither costs.

Regards,

[odysseus2000]

Fred Bloggs
On the other hand, if Apple tried a little less hard to make simple repairs by owners/third parties - Maybe changing end of life batteries, for example. Then Apple would look a lot more credible is this respect than just making sound bite press releases about their environmental credentials. At the moment, I see little real credibility to their claims.

The right to repair movement has not done so well recently, opposed by Apple & most other manufacturers. I believe one US State has approved it, but most have refused to force makers to reveal information useful to repairers or to make their products more easy to repair, change batteries etc.

It's an area that can vex me as I quite like to do things like this, but the issue is also about innovation & do folk really want to repair things that are substantially below the performance of a new one? So if e.g. someone repairs a 3 year old widget, have they then got something that is as good as a new one, or something that puts them at a serious disadvantage. A recent example being computers using Xp software. Sure these worked well for many things, then they got hit with ransomeware, now Microsoft have released a patch. One can experience this in many things, e.g. does a say 3 year old iPhone give you the performance of a new one, a 10 year old car the fuel economy & safety of a new one?

Most folk I know loathe the idea of repairing things, just wanting something that works for a few years, then getting a new one. This is some function of prosperity, but it also fits in to the powerful emotion of laziness that drives much human behaviour.

Regards,

[odysseus2000]

Fred Bloggs
but why would I need a new iWidget if my three year old one does everything I need? Why would I even care about how my old iWidget compares to a new latest generation iWidget? I never buy cutting edge iWidgets, I don't need cutting edge performance, or bragging rights, or the very high up front cost of the latest SIM free hardware. I might be in a minority here, but I do see it as a serious sustainability issue, not being able to do simple things like fit a new battery myself.

I find my trusty old Nexus 5 perfectly adequate for what I need. But I can't change the battery when it eventually requires it and Google no longer release software security updates for it. I think that is rather sharp practice myself and will likely lead to replacement several years before it really becomes necessary. Contrast that with the choice of watches for me and the wife - we both own watches that are >25 years old from new, are as good today as they were when new and essentially will they not only last us for our life times, but very likely our children's lifetimes too. THAT is good sustainability.

Yes,I know where are coming from, but comparing centuries perfected watch technology to modern still rapidly evolving technology is not comparing like to like.

Sure if your old widget does what you need then keep it, perhaps even have the battery replaced. But for most folk the difference between say an iPhone 7 & say an iPhone 3 is dramatic, much better camera, much faster & all of these improvements make for new ways to benefit the user and it's likely that improvements will continue as processors get faster & more intelligent software.

Consider cars. A model T Ford will do what most folk need, but its slow, has minimal safety, poor reliability etc. If everyone who had a model T had said this is good enough we would not have new cars with all their advantages.

There is clearly a lot of benefit for the manufacturer, but also for the user.

Once the old was mostly cast into either a blast furnace or landfill. Now much more can be recycled which is good for the environment even if less good for the purchasers who have to buy new every several years.

It is a complicated subject, but for the moment the relentless uptake of new models looks set to continue which is why I like Apple, even more so today after the price fell, and I hope to get it lower still.

Regards,

[YeadonLad]

I might be in a minority here

I doubt it.

YL
Nokia 1600 user - 11 years old and it still does the job I need it for. Do admit that we have just changed the car though, hope that the new one lasts nearly 17 years like the old one did.

[odysseus2000]

Yeadonlad

Nokia 1600 user - 11 years old and it still does the job I need it for. Do admit that we have just changed the car though, hope that the new one lasts nearly 17 years like the old one did.

17 year old cars are the ones I buy!

I bought one last week!

Regards,

[tjh290633]

Swaminathan Ramesh is the subject of articles about a process for turning waste plastics into a fuel to replace diesel. If you Google his name, you will find a lot of links about his process.

TJH

[odysseus2000]

tjh

Swaminathan Ramesh is the subject of articles about a process for turning waste plastics into a fuel to replace diesel. If you Google his name, you will find a lot of links about his process.

Quite fascinating & a blessing for most of us if it can be made to work. Thanks for posting.

Another down force on the extractive oil industry, but technological change always hurts some existing business.

Regards

[gryffron]

A lot of things that get recycled don't get used for the same thing. Infinite reuse, in exactly the same form, is quite hard, as impurities tend to creep in.

Iron, gets purer every time it is recycled. All higher grade steels are made from 100% scrap, not from raw ore.
Paper gets much worse, as the long polymer chains degrade. So recycled paper is very poor compared to new.
Plastics also degrade. Partly down to long polymer breakdown, but mostly due to impurities creeping in. The solution is to re-purpose scrap plastic. It is already being turned into railway sleepers (last longer than wood), and road surfacing (quieter than stone), as well as the fuel you have already found.

Ultimately - everything gets recycled. It just that some things may take a very long time.

Gryff

[odysseus2000]

gryffron

A lot of things that get recycled don't get used for the same thing. Infinite reuse, in exactly the same form, is quite hard, as impurities tend to creep in.

I suppose the classic example of very long term reuse is water which in many ways is quite a remarkable material, even able to be recycled aboard the space station with no obvious detriment to the folk who drink it over and over again.

I kinda wonder whether recycling process will develop in revolutionary ways that over come issues of impurities, polymer breakdown etc. Doesn't seem to be many signs of it yet, but it is an area that has not been focused on before and the developments at Apple over the last decade seem, at least to me, to be remarkable.

Feels like it may become a very interesting investment field as anyone who can develop commercial systems will likely have the raw materials for free, perhaps even paid to take them, but for now it is still in the category of dreams.

Regards,