Does recycling work?

One of the challenges we face when it comes to climate change is not just how to reduce carbon emissions, but how to scavenge back some of the carbon we’ve already put into the atmosphere... ideally without compromising our standards of living. And this week scientists at Cambridge University unveiled a technology that might help to achieve these aims: it’s an ‘artificial leaf’ that, like real leaves, uses light to turn carbon dioxide into a useful fuel - in this case a mixture of carbon monoxide and hydrogen called “syngas”. Katie Haylor went to see it in action with its inventor, Erwin Reisner...

Erwin - We have demonstrated that we can convert the greenhouse gas carbon dioxide together with water into an energy carrier which is known as syngas. Syngas is a gas mixture made out of carbon monoxide and hydrogen, currently used for methanol synthesis for example, you can also extract the hydrogen from syngas to make fertilizers. We are excited about syngas because syngas can be converted to liquid carbon-based fuels, essentially gasoline.

Katie - Let's take a closer look then. So on the desk in front of us is a box. Is that plastic? It's transparent in nature and then there's lots of nuts and bolts and things going on. Separately you've got a little square with some wires coming out of it. Can you explain what is happening step by step?

Erwin - Absolutely. So inside the box, we have this artificial leaf which means this is electrodes, and the electrodes now take up the light, and this energy from the light is being used to drive our catalysts.

Katie - Is the light being absorbed? What's going on? What materials are we talking about?

Erwin - Yes it's being absorbed by semiconductors, a semiconductor can absorb light, in our case the semiconductor - rather than producing electricity - we use the energy to drive a catalyst to make syngas.

Katie - It's been described as an artificial leaf. And on the cycle over here I couldn't help but pick up this beautiful, green, autumnal leaf in front of me. How does this relate to what you're doing?

Erwin - We try to adapt the concepts from photosynthesis and in our case we also have a leaf configuration, that's the quite thin platelet, if you like, known as an electrode. And here we also take the carbon dioxide, but we do not produce sugars. We want to produce gaseous or liquid products.

Katie - So you've got a box which has carbon dioxide pumped into it through some water or an aquaeous solution. Then you've got your “leaf”, which has got some semiconductors in it which absorb the light and does some clever chemistry with the light on some catalysts in the leaf. And that is how we get the syngas?

Erwin - That's correct. And it's really that the choice of all these materials and the combination that make this a functional system.

Katie - What about a cloudy day? What about winter in the UK?

Erwin - So one of the strengths of the system is that it does not rely on very strong or high light intensities. It can also operate under cloudy days or even in the winter. So quite low light intensity situations.

Katie - Now why hasn't this been done before? What are the current technological or scientific barriers?

Erwin - The artificial leaf contains a very large variety of different elements, very unproblematic elements, but it also contains a range of problematic or poisonous or rare elements. This would for example be lead or silver.

Katie - OK. So would the idea be to swap those out?

Erwin - Yes that's what we will do in the next stage. So we know precisely which layers to replace into substitutes and we will look for replacements.

Katie - And once we've got the syngas, how do you go from that to fuel? How green is that process?

Erwin - So this process is established. It's known as the Fischer–Tropsch process and with certain high temperature and catalysts you can convert the syngas into the liquid fuel. This is something we can in principle also do sustainably.

Katie - Is it scalable?

Erwin - We hope so. So there are many limitations at the moment. The stability is not high enough and also the efficiency is not high enough. But we hope with further development we can improve on these.

Katie - How would you see this kind of technology being used?

Erwin - We see there's still a lot of challenges ahead. We cannot promise that this will be implemented in a couple of years. We recognise for real commercial application there are probably decades of development needed. But I think there are many possibilities. One way will be to use it on a very large scale, centralised energy production. But there's also a possibility for off-grid or localised uses. So I don't see a reason why this can not be a smaller scale device that generates energy where there's no grid.

The world of online gaming is huge among teenagers, and is becoming a hotbed for cybercrime. One particular type of hack is a distributed denial of service (DDoS) attack, where a victim’s internet connection is flooded with so much traffic that it shuts down. Gamers are increasingly using these attacks to gain an advantage by knocking their opponents offline. But this activity is illegal, and it can be very disruptive for other innocent Internet users, who can be taken down in the crossfire. So Ben Collier, from the University of Cambridge, has been looking at which sorts of intervention actually work; putting people in prison and stiff penalties don’t seem to make much difference. But taking down the computer networks used to do it works quite well, but best of all is just sending simple warning messages to the people commissioning the attacks. Adam Murphy heard why...

Ben - We've been looking at a particular type of cyber crime called a DDoS. It's like when you go to visit a music festival website when the ticketing is open and everyone crashes the server because there's too many people going on. It's basically like that, but it's been weaponized as a form of cyber attack. So what we've done is we've used a bunch of detection techniques looking at what the police are doing and seeing whether or not it works.

Adam - So how would you go about actually doing that to someone else's computer?

Ben -  There's two ways you can do it. So the first one is called a reflection and amplification attack. That's where you look for computers on the internet that are poorly configured and you send them a signal, but when you send them the signal you pretend to be the victim. So you send this signal to them. It's quite a small signal, doesn't take up much resources for you, and they send a very very big signal back, but instead of sending it back to you they send it back to the victim. The second way is using botnets to essentially infect other people's computers using computer viruses and get control of them, and then use these to send lots and lots of these signals and packets of information and overwhelm people's computers.

Adam - Why would you want to do that? So what are people looking to use these for?

Ben - There's a range of different reasons why you might want to knock someone offline. So first and one of the most common ones we see is computer games. So if I'm playing an online computer game, like Call of Duty or something, and I am not very good at it and my opponent is beating me a lot.

Adam - I can relate to that.

Ben - Yeah me too. Then I might want to annoy them or get back at them by booting them off the Internet, and then I would use this service to find out their IP address and then knock off their home connection basically. But the problem is then you might knock off everyone else who is on, you know in their village, or wherever that's on the same sort of service basically. There's some more sort of nasty stuff as well, although those are obviously serious too. So you might want to blackmail a business or another website you know by saying we'll take you offline unless you pay this much money, and then we get into the really serious stuff, so you can use this against infrastructure. For example, you could use it to take a hospitals public systems offline, any kind of public service or things like that, which has a public facing IP address. You can use this to take it offline basically.

Adam - Why do the interventions that work, so taking down the infrastructure and messaging people, why do those interventions work so well?

Ben - So for the infrastructure we think that's because it's a very centralized market. So actually there's around about 50 of these services, you know 50 or 60, doing any real number of attacks at any given time. But actually there's a lot of reselling going on. So there's a small number of people, maybe 10 to a dozen, they're actually running most of the infrastructure, a small number of services, and they basically sell on to the other services their capacity. This means that if you take down the infrastructure, it causes a lot of knock on effects for everyone else, and actually the people that run the infrastructure, so the server managers, their jobs really really boring.

So they're actually quite easy to dissuade, and when we saw this big FBI sting actually we saw lots of these server managers who the networks depend on say yeah I'm done, I'm not interested in this anymore. The messaging interventions a bit more complicated. I think possibly the reason behind it is a kind of like digital guardianship sort of thing. One of the things people often say about cybercrime is that it's often difficult to know online what's legal and what isn't, or when you've crossed that boundary, and I think for a lot of these people there's a lot of basically, young kids, doing this stuff who are doing this but they don't really realize it's illegal.

Actually in these communities a lot of people say ‘oh it's not illegal it's fine’, ‘you know the police don't care about this stuff’. But I think if you're a 15 year old kid and you're sort of searching for this stuff, these adverts hit you basically as soon as the thought was forming in your mind that you want to do it. Bear in mind the thing you're about to do, that we can see you about to do, because you're googling it is illegal, just so you know. So it's kind of like a tap on the shoulder basically saying we're watching you, and we think that the timing and the target nature of the adverts is actually causing this effect. 

This is the part of the show where Chris Smith and Izzie Clarke read out your correspondence...

Chris - We've heard from Kay. She's in Australia and she's written in with her own theory about dark matter. She says she thinks it's just all those lost black socks that have disappeared from the world, they had to go somewhere. You're an expert on that, Izzie, you actually looked at the maths of lost socks earlier this year...

Izzie - Yes, well I was thinking that as I was hanging up my washing today, I had three different black socks, none of which were in a pair, so I'm right with Kay on that one.

Chris - Well, she says of course no one can see the dark matter because no one can find the dark socks. But Rob Eastaway, who is a mathematician, told you that the solution to the black sock problem is just to buy exclusively black socks and then you never know you've lost them.

Izzie - Well, absolutely. Or check the weird little filtration part of your washing machine and they might be there. But don't go around disassembling your washing machines is my advice.

Izzie - And listener John has a correction to our piece last week about the nano-guitar string. In the piece, it was wrongly said that Jimi Hendrix used feedback by moving his guitar towards a microphone, whereas he actually just moved his guitar, which is a microphone of sorts, towards the amplifiers. Thanks for pointing that one out.

Chris - So if you have any comments, feedback, criticism, or suggestions for the program that you'd like aired on the mailbox you can send that in now. It's chris@thenakedscientists.com. You can tweet @nakedscientists, we've also got our Facebook page, of course, you go to facebook.com/TheNakedScientists, and we'll pick them up.

Lots of cat foods and certain drinks come in pouches made out of plastic aluminium laminate. This is a decent material environmentally, because it’s so light compared to pure aluminium, so it saves resources and fuel during transportation. But until recently it couldn’t be recycled at all. That’s changed thanks to a company called Enval, which has developed a process to separate the plastic from the aluminium. And supposedly this technique both powers and pays for itself. Phil Sansom went to visit the plant and meet Enval CEO Carlos-Ludlow Palafox...

Carlos - We have baby food pouches, we have paint tubes, we have sashes, bags for instant coffee and pet food pouches. Plastic aluminum laminates are being used for all sorts of products and what we have managed to do is to create a process that actually renders these things, plastic aluminium laminates, recyclable.

Phil - Before they weren't recyclable?

Carlos - Before they weren't recyclable. We separate plastic from the aluminium. It's a chemical separation in the sense that we pyrolyse the plastic. Pyrolysis is a process where you have something that could burn, but you apply that energy in the absence of oxygen. Therefore, that's something that could burn doesn't burn because there's no oxygen, it just degrades into other things. In the case of a plastic, if pyrolyse the plastic you heat it up to very high temperatures, in this case around 600 degrees, and because the plastic came from oil in the first place, what we do is to produce an oil similar to what you have in crude oil. So you are turning back plastic into its original crude oil. We feed the packaging into the shredder. All the pouches, sachets, tubes etc. et get shredded into flakes and that goes into the oven. We use microwaves to heat up the reactor where the reaction takes place.

Phil - Microwaves?

Carlos - Microwave induced pyrolysis, correct. Now some of the listeners, I am pretty sure will think how on earth are you heating up plastics using microwaves, when I know that if I put a plastic dish with soup in the microwave in the kitchen the soup heats up the plastic doesn't? So how do we do it? Well we heat up carbon with the microwaves and once that carbon is hot then we start the addition of material.

Phil - So the microwaves don't actually heat up the thing that you're changing?

Carlos - Correct. So the microwaves heat up carbon and then the carbon transfers the heat by conduction to the material, the plastic. The plastic pyrolyses. The gases that are the paralytic gases escape the reactor and we cool them down. About 75 percent condense into an oil, and around 25 percent of what was plastic remains as a gas, and that gas we feed into an electricity generator that then feeds the microwaves to produce the energy that we need for the process.

Phil - So you can use only a quarter of the petrol product basically to power the rest of the plant?

Carlos - Correct. The aluminum on the other hand, it forms flakes that then we melt and form ingots.

Phil - So all this that Carlos is describing happens inside a big industrial building where Enval has set up their plant. So I asked him to show me inside. Wow...

Carlos - Well this is it. This is where the magic takes place.

Phil - It's really, really big!

Carlos - For a pyrolytic process it is actually quite compact. That big box for all practical purposes is a very large microwave oven, much larger than the one that you have in your kitchen, two by two meters, and more importantly power is a hundred and fifty times more powerful than a than a house one.

Phil - How long would it take to heat up my soup in one of those?

Carlos - Less than two seconds.

Phil - By the way, what is that smell?

Carlos - It's the smell of oil.

Phil - Not that I'm not impressed, but let's get out of the noise and the smell.

Phil - Back outside Carlos shows me some of the end products of the pyrolysis. Pure flakes of aluminium or at least as pure as when the laminates were first manufactured.

Carlos - Lately what we have done is to actually do the melting of these flakes into ingots like this one that I'm holding in my hand. It's much more valuable to sell the aluminium as ingots than to sell it as flakes. The oil is also a very valuable product and we sell it as heating fuel, but one of the plans that we have is to use the oils for the production of virgin plastic. So full circular economy for the plastics as well, not only for the aluminium.

Phil - Where does a company like you fit into the way that recycling works in this country?

Carlos - Excellent question. Recycling is a very complicated world. When a new material comes out the way the sector normally is, is very slow reacting to those kind of things. What tends to happen is that companies that develop recycling processes need to prove over and over again that it actually works before the large waste handlers actually want to engage. We recently decided that we're not going to stop wasting time waiting for large waste handling companies to buy plants from us. We're going to put more plants ourselves.

Phil - But if it's the waste operators job to recycle stuff that can be recycled, why aren't they just picking this up?

Carlos - Well it's very complicated because some of the contracts between the waste contractors and the local authorities or the county councils are insanely long, 20 years long, and the waste composition of 10 years ago has nothing to do with the waste composition these days because brands change the kind of packaging that they use. So you say, well they have a duty to collect and recycle. Yes, certainly from a point of view when that duty is established in a contract. But if a new model comes in the middle they have absolutely no duty to collect absolutely anything. Even worse they have no incentive whatsoever, because for a waste handler whether a pouch of baby food gets collected or gets landfilled makes zip difference to him because they get money either way.

Phil - You are joking? There's no incentive for them to recycle something?

Carlos - Not necessarily for the waste handlers. A lot of the waste sector, the traditional waste sector, says why do we bother doing more complicated operations if we can just carry on pushing stuff into the ground. So unless they are forced to do it, they won't do it.

Phil - I find it quite shocking that it's not as simple as if you can recycle something physically, then you just whack it in your blue bin and it'll get to the people who can recycle it.

Carlos - No it's really really not that simple. Sometimes it has nothing to do with the materials.

Phil - So what's it like being in this industry?

Carlos - It is fascinatingly chaotic.

Obviously we shouldn’t stop recycling - so what can we do to fix it? With Izzie Clarke and Chris Smith to help untangle the future of waste is Margaret Bates, Professor of Sustainable Waste Management at the University of Northampton, who describes herself as “obsessed with anything waste-related”...

Margaret - I think it is working. The economics are necessarily the most important thing. The carbon benefits, the impacts on climate change are hugely important. I totally agree with him that the social aspects are really important as well. People buy something, use it and then go why can't I recycle this? Where as actually, we need to have the situation where when you're buying something, you factor into its end of life at that point. Comments were made earlier that our infrastructure really hasn't kept up, and it hasn't. Changes in waste over the next 20 to 30 years will need an investment of about 35 million, and to be honest when we're talking about big waste handlers they don't really exist anymore. They are resource management companies, they spend a lot of time and effort in making sure that the way we collect things is the best way to recover the value as much as possible.

Chris - Margaret, can I put something to you, because I was I was cleaning my teeth today...

Margaret - Good.

Chris - Yes indeed. My dentist would be delighted. Well actually maybe not because it means I make fewer visits, but I bought myself, a number of years ago, an electric toothbrush and I've been delighted with it. It’s lasted eight years, but now I've got to the stage where the battery has clapped out. It doesn't survive more than two nanoseconds away from the base station charging and I am going to have to throw it away. What infrastructure is in place to recycle gadgets like my toothbrush?

Margaret - There are a number of high streets where you can take your electricals to be recycled or you can look on Recycle Now, which will show you where you can recycle materials, but you don't necessarily need to buy stuff. So perhaps there is an opportunity to have a leasing model on a toothbrush where you don't buy it. They still own it and then when you've finished with it you give it back to them, and they swap it for another one that might be repaired or refurbished or just have a new battery in it.

Chris - I take it you're referring to the body rather than the brush head? You wouldn't want a second hand one of those would you Margaret?

Margaret -  I really wouldn't want a second hand one. I'm not sure I'd want to use mine twice.

Chris - No, I mean the cynic in me is thinking is this engineered obsolescence to make sure I go and buy another toothbrush because it's not in the manufacturer's interest, is it? To make something, which if it works too well and lasts too long, they can't sell me another one? There's always going to be that tension isn't there with industry, where they want to make something that lasts a certain time which incentivises you to go and buy another one?

Margaret - But that's why we need good policy. Good - what’s termed - “extended producer responsibility”. So it incentivises things that last longer, that are easier to repair and easier to recycle at the end of their life.

Chris - So what fraction of goods and products are currently being built or designed with their end of life in mind at the outset?

Margaret - We have absolutely no idea really. End of life isn't a factor in the manufacture. We are getting better. So if you look at plastic bottles for example, the average recycled content of a plastic bottle is about 15 percent, but that's going up and there are government plans to tax people extra if they don't put a minimum of 30 percent recycled content in.

Chris - Have they actually gone in further up the food chain as it were and said, you can't design stuff before you've come up with a valid plan for how you're going to deal with it when it has died?

Margaret - That's what the extended producer responsibility legislation is about, but interestingly as a householder we don't have that. So there's a system called Pay As You Throw, where every wheelie bin produced in Europe since 1996 has a microchip housing in it, and in many countries householders are charged proportionate to how much waste they produce. Whereas you and I can throw away as much as we'd like and still pay the same amount of Council Tax.

Chris - Bit dodgy that though isn't it because it incentivises people to either fly tip or go and check it in someone else's bin and then your neighbor ends up paying for your rubbish, don't they?

Margaret - Well no not really. I mean if they put the price up of your shopping do you start shoplifting? Most people do the right thing and we'll try and change the behaviours to make sure they carry on doing the right thing, and this is really common throughout Europe and other parts of the world. Even tried it recently in Guernsey and its reduced the amount of weight people produce and that's what we really need to look at. We focus very much on recycling. Recycling isn't the top of the best things we should be doing, it's not even the second. So we should be reducing the amount of waste we generate and sadly charging people proportionately to how much waste they produce is one of the good ways of doing that.

Chris - I think the most poignant point that Roland Geier made when Adam spoke to him was was to say that there are lots of people who think they're doing the right thing by going and buying stuff that is labelled as recyclable, but just because it's recyclable as Brian is saying it doesn't mean it gets recycled, and so really what we need to do is to shift the mindset of people onto making that demand for things that have been recycled, not just are recyclable.

Margaret - Yeah. We need to start off by not buying things we don't need. If we do buy stuff, we need to make sure it's got a high recycled content. Then we need to reuse it as much as possible and then when we run out of any use for it, then recycle it. So it's part of looking at the whole lifecycle of how we interact with our stuff.