In April this year an international team of archaeologists working in Pompeii announced that they had found definitive evidence that the Roman inhabitants of the city were recycling and reusing waste material, particularly in the construction of buildings.
It followed careful analysis of large mounds of material outside the city boundaries – long thought to be simply rubbish – which in fact turned out to be “staging grounds for cycles of use and reuse,” according to study lead Professor Allison Emmerson.
She said: “For the most part, we don’t care what happens to our trash, as long as it’s taken away. What I’ve found in Pompeii is an entirely different priority, that waste was being collected and sorted for recycling.”
It is perhaps one of the first (albeit small-scale) examples of a circular economy: a model of production and consumption which involves reusing, repairing, refurbishing and recycling existing materials and products for as long as possible. Importantly, it aims to design waste out of systems.
On the face of it, certainly it seems to make a lot of sense.
Yet more than 2000 years on from Pompeii, a linear economy is by far the predominant model in today’s globalised society. This follows a ‘take-make-consume-throw away’ pattern. And importantly an ever-increasing accumulation of waste and often more associated pollution to boot.
Approximately 100 billion tons of minerals, fossil fuels, metals and biomass enter the world’s economy each year
According to estimates by Netherlands-based impact organisation Circle Economy, approximately 100 billion tons of minerals, fossil fuels, metals and biomass enter the world’s economy each year – yet just 8.6% is currently cycled back. Worse, this figure has actually fallen from 9.1% in the two years since the report was first launched in 2018.
Even within this fraction of cycled materials not all cycling is equal. A lot might involve so-called ‘downcycling’ of materials into a lower quality substance, which is then used to create a lower-grade product.
Often this is due to the nature of the material which prevents it from retaining its original properties once re-processed. Therefore, downcycling does not reinsert the material back into its original cycle. – and the life-cycle actually looks more like a ‘spiral’ than the ideal circular economy.
Halting progress in this area is not through lack of ideas, proposals and innovative technologies. A Google Scholar search (from 6 August 2020) gives 18,500 results for articles relating to ‘circular economy’ from the start of 2019 onwards and 82,000 for ‘life cycle assessment’ in the same period.
Transform and innovate: Imperial solutions
At Imperial there has in recent years emerged an abundance of potentially transformative and innovate solutions – such as making bioplastics from waste plant matter that can more easily be recycled and reused; using wastewater streams from different industries to produce electricity; and exploring the potential of waste chicken feathers to create a new range of thermal, water repellent materials.
There needs to be a total rethink in how we produce, use and manage materials across the whole life cycle.
Some of these ideas have achieved a degree of traction and not a small amount of plaudits. Startup Notpla provided 30,000 edible and biodegradable liquid capsules for runners as alternatives to plastic bottles at the 2019 London Marathon.
But it’s generally a difficult road pitted against large, powerful incumbents, very much in the linear economy mould.
“Much of my research over many years has focussed on turning waste materials into useful resources; but that type of research can only go so far,” says Chris Cheeseman, Professor of Materials Resources Engineering in Imperial’s Department of Civil and Environmental Engineering.
“If you’re talking about a zero waste society we’ve got to be much more radical. There needs to be a total rethink in how we produce, use and manage materials across the whole life cycle. We need to design for a circular economy.”
We spoke with Chris and other leading academics at Imperial, who identified five radical ways in which we might be able to move closer to a zero-waste society.
1. Only make things that can be recycled locally
For a start, it’s important to define what we mean by ‘waste’ and if we are talking about a zero waste society then we need to be clear about which ‘society’ we mean. The challenges in the developing world are orders of magnitude more difficult than say in the UK and Northern Europe where we have a largely effective waste management system.
That is why greater investment in appropriate waste management is required in the developing world and this is arguably the most important single thing we can do to avoid extreme pollution from waste including addressing the plastics in the ocean issue.
As Chris points out, “we have seven and a half billion people on the planet and possibly two billion don’t have access to a proper waste management system including waste collection. But in many countries waste management is too far down in the list of priorities for countries to even consider.
It seems strange that some countries have advanced national technology projects, even space programmes, yet do not have national infrastructure or capability for waste management locally. The result is that waste is put in waterways or dumped, not landfilled and there is a significant difference. The development of properly engineered and managed landfill sites would be a major step forward.”
The UK exports 611,000 tonnes of recovered plastic packaging to other countries
Nevertheless, according to Chris, it should be an eminently realistic aspiration for a country like the UK to become a zero-waste society, although this clearly depends on how we define waste. It starts though with getting our own house in order and moving to a situation where much of the materials we manufacture and use are handled or managed within UK boundaries.
The UK exports 611,000 tonnes of recovered plastic packaging to other countries, including Malaysia and Indonesia – both of which have high rates of plastic ocean pollution – and more recently Turkey. A recent investigation by the BBC found that some plastic waste from Britain sent to Turkey for recycling is instead being dumped and burned on the side of roads.
Chris says, “if we are going to see a paradigm shift in the way we deal with the material resources we use, then we have to think about not allowing any material to come onto the market that doesn’t have a very clear UK recycling route. I’m particularly referring to packaging. This is often composite and multi-layered materials, and despite claims to the contrary these are very difficult to recycle.”
Chris believes we can go even further in terms of corporate responsibility and accountability for materials and packaging.
Some countries have advanced national technology projects, even space programmes, yet do not have national infrastructure or capability for waste management. The result is that waste is dumper or put into waterways…
Major material suppliers need to take their materials back
According to Chris, “companies are very good at making products, selling them onto the market and then washing their hands of that material – it becomes someone else’s problem. They are very good at the front-end of the supply chain, but the material recovery chain is totally ignored.
Their businesses rely on producing huge amounts of waste with no social responsibility to take it back. If you’re talking about a zero waste circular economy, then major material suppliers need to take their materials back and recycle them: it should remain their property and their responsibility to manage it through recycling and reuse.”
2. Kick start a revolution in design for disassembly and reuse
One major philosophy in the field of circular economy and zero waste is that of ‘design for disassembly’. It follows that in the very conception stage, every new product should be designed such that it can be separated into its constituent materials or subsystems at the end of its life for recycling or reuse. That should even apply to more complex electronics such as mobile phones, laptops and car batteries.
One advocate is Professor Peter Childs, Chair and Leader in Engineering Design at Imperial’s Dyson School of Design Engineering.
He says, “I wonder whether companies like Amazon with their powerful procurement could choose to work with OEMs [original equipment manufacturers] to encourage a gold standard accolade or quality assurance that the OEM has engaged with a whole series of measures so that at end of life, a product or part can be dealt with properly. Different products may well need a different end of life approach and design for disassembly isn’t going to be right for everything.”
This approach is echoed by Professor Magda Titirici, Chair in Sustainable Energy Materials at Imperial’s Department of Chemical Engineering.
Magda explains, “we recently ran a project with some students, where we got hold of some end of life laptops and mobile phones to disassemble. When you try to open a battery, you find they are all made in a very different ways, some are glued together, or rolled, it never says on the battery packages what materials they have in and what the chemistry is.
It’s a black box where you can’t recycle anything. That needs to change. If we manufacture for disassembly, with clear labelling, perhaps with labels that could be sorted with robots that could be a solution. Smarter manufacturing is key for recycling too.”
Clearly changing corporate behaviour can be very challenging in an aggressive free market; companies often simply take the easiest and cheapest solution in complicated supply chains and there is little incentive to cooperate to change practices.
But as Imperial teaching fellow and entrepreneur Elena Dieckmann has found, greater cross industry collaboration can actually reveal unexpected connections and mutual benefits for companies. Her company Aeropowder is developing new ways to use waste chicken feathers in sustainable thermally insulating packaging and potentially even insulation in construction.
One person’s trash is another’s treasure
Elena argues, “as they say: ‘one person’s trash is another’s treasure’; the poultry industry would probably normally never have any reason to interact with the construction industry, they are so far removed from their respective business models. But there are probably thousands more of these potential connections out there like this waiting to be leveraged.”
Governments as well as academics have a role to play in fostering and convening such connections. Peter says ‘coopetition’ – a combination of cooperation and competition, which has previously proved successful between software and hardware firms, could be the key in the circular economics of disassembly and reuse.
“I love the idea of local production and circular economies locally. I’m discussing this with local politicians and local industry groups and I believe we can do this through coopetition. Where you get a few hundred companies to come together, they may be highly competitive and even loathe each other, yet on their own they simply can’t manage the whole supply chain. But collectively all of a sudden there are advantages through that coopetition”, says Peter.
Perhaps the first practical step towards a revolution in design for disassembly and reuse is to design things to be more easily repaired. Earlier this year the European Commission adopted a new Circular Economy Action Plan, as part of the European Green Deal, for sustainable growth.
It includes an aspiration to establish a new ‘right to repair’ and a new horizontal material rights for consumers for instance as regards availability of spare parts or access to repair and, in the case of ICT and electronics, to upgrading services.
Interestingly, reviews of new electronic devices and laptops have started to address sustainability and some even have repairability scores out of 10 – something pioneered by specialists iFixit.
Zero waste can’t be achieved without a complete overhaul of our economic model
As a young founder at the beginning of her journey in the circular economy, Elena reflects on some of this:
“Zero waste can’t be achieved without a complete overhaul of our economic model in general, so as long as new things are cheaper than refurbished things it’s just not going to work. And economic viability is absolutely key to achieving a circular economy”.
“I visited Cuba a few years ago, which is a great example of a circular economy; the [US trade] embargo actually made them into a makeshift nation. I was fascinated how many workshops they have for every item: watches, roller pens, kitchen toasters and of course the famous cars. They are all precious items. Perhaps we can learn some lessons there.”
"Zero waste can’t be achieved without a complete overhaul of our economic model"
Elena Dieckmann of Imperial’s Dyson School of Design Engineering
Elena Dieckmann of Imperial’s Dyson School of Design Engineering
3. Break dependency on rare metals with advanced waste solutions
The UK government recently made a proposal to bring forward a planned ban on the sale of new petrol, diesel and hybrid cars in the UK from 2040 to 2035.That would mean a huge increase in the number of electrical vehicles on the road: potentially good for carbon emissions (if powered by renewables) and particulate air pollution.
But the lithium ion batteries that power them have been the focus of concern and recent negative media attention with regards to unsustainable and exploitative practices and political instability. Cobalt, a key component in lithium-ion rechargeable batteries, is predominantly mined in Democratic Republic of Congo (DRC), with reports of incidents of child labour and terrible working conditions.
Telsa recently signed a deal to buy 6,000 tonnes of cobalt each year from the mining giant Glencore, despite two years ago promising to eliminate the metal from the product mix over concerns. Bolivia is estimated to have around nine million metric tons of lithium, the largest reserves in the world, mostly found within the scenic salt flats.
But some countries, including China and Germany have been accused of exploiting these resources with lopsided deals that don’t bring enough benefits to the region. Indeed estimates suggest that China controls 85% of the world’s capacity to process rare earth metals, a matter of concern in turbulent geopolitical times.
In September 2019, the World Economic Forum released it’s ‘Vision for a Sustainable Battery Value Chain’. It calls for 54% of end-of-life batteries to be recycled in 2030, thereby contributing 7% to the overall demand for raw materials for battery production in that year. This will require recycling capacities to be increased by a factor of more than 25 in 2030 compared to today.
“Can we use waste available locally in Europe and recycle that into really advanced materials that could be implemented in batteries?
Magda’s research group is trying to be even more ambitious in this area. In October 2019 she was awarded £2.7 million over two years to investigate alternative energy storage technologies to lithium ion, with more sustainably sourced materials – even examining the feasibility of using waste to make batteries. Magda reflects:
“Can we use waste available locally in Europe and recycle that into really advanced materials that could be implemented in batteries? We could use biowaste and food waste to make a solid biopolymer conductive electrolyte with more sustainable battery chemistries based on sodium, potassium, zinc and aluminium.
We could carbonise the waste in a smart way to make synthetic graphite for the anode. We can potentially develop cathodes based on metals that are abundant and recycled such as iron or manganese.”
Sustainable materials: Making fuel cells from food waste - Professor Magdalena Titirici
Sustainable materials: Making fuel cells from food waste - Professor Magdalena Titirici
4. Thinking the unthinkable: incineration and waste-to-energy solutions
Some academics are contemplating even more radical, drastic and controversial measures to address the problem of ever-accumulating waste. When considering the low real-world rates of recycling and the energy used in transportation, separation and treatment of materials, then waste-to-energy solutions – a.k.a. incineration – may not be so bad. Particularly when taking into account the common problem of plastic polymer contamination, which complicates recycling even more.
As Peter explains, a ‘tri-generation system’ of incineration can simultaneously generate electricity, heating and cooling from the combustion of a fuel: in this case various forms of municipal solid waste. Sometimes called combined cooling, heating and power (CCHP), these systems can attain higher overall efficiencies than CHP/cogeneration or traditional power plants.
The exhaust can also be treated, if the temperature is high enough, to eliminate a lot of harmful emissions and particulates.[AC1] Meanwhile carbon capture, utilisation and storage technologies (CCUS) can help offset some of the carbon. Indeed the ‘utilisation’ can be critical in a wider circular economy. Imperial startup Econic Technologies has a solution that takes waste CO2 onsite from industry and uses it to make plastic products replacing up to 50% of the normal fossil fuel raw feedstock.
These are the sort of ideas we need to discuss: provocative and slightly crazy and radical.
“I’m basically very supportive of energy from waste and I see it as a key part of a sustainable waste management system that deals with residual waste, the waste that can’t be recycled,” agrees Chris.
“One approach would be to encourage design for combustion. We could move to a cellulose-based society, with packaging and products made from photosynthesis and everything we make can be burned as fuel for energy. It releases carbon dioxide, but it’s carbon neutral and not fossil fuel-derived. These are the sort of ideas we need to discuss: provocative and slightly crazy and radical. But it is clear that the current approaches are not working.”
Still, both researchers stress that waste-to-energy should not be seen as a default option, and we have to be mindful of unintended consequences. For example there is the non-trivial challenge of creating infrastructure for residual waste, that starts creating a ‘pull’ for that waste stream, creating a need to ‘feed the beast’. As always, systems and business model needs to be considered as carefully as the technologies.
5. Decisive government action and collective responsibility
The current coronavirus crisis has shown that governments can, when required, act decisively to tackle an immediate existential challenge. Meanwhile, citizens have in the most part shown resolve and solidarity in terms of behavioural changes for the greater good of wider society.
These are essentially the key ingredients in achieving a zero waste, circular economy. While some of the radical solutions floated above may take time to come to reality, there are things that the UK government, and others around the world, can do now to set us on a path towards a more circular economy and minimal waste. These include, but are not limited to:
- Greater investment in basic waste management systems and facilities in developing nations (access to a basic waste collection system should be a fundamental human right)
- Ban all export of materials and products for recycling, reprocessing or disposal and promote local responsibility for processing of materials
- Phase out the manufacture and sale of single-use plastics for selected applications. This follows the lead of Germany, which recently agreed to ban the sale of single-use plastic straws, cutlery, cotton buds and food containers from July 2021, aligning with an EU directive intended to reduce plastic waste
- Phase out the use of composite packaging such as disposable coffee pods and Tetra Pak or require the companies that produce them to take these products back
- Implement a ‘right to repair’ for electronics and ICT equipment, including a right to update obsolete software (in line with similar EU commitments)
- Move to high levels of separate collection of textile waste (in line with similar EU commitments by 2025)
- Make a commitment to recycle half of all end-of-life batteries by 2030 (in line with recommendations from the World Economic Forum)
Interestingly, a recent academic paper in the journal Science by a collaborative team (including Imperial’s Dr Arturo Castillo Castillo) conducted detailed modelling to estimate the effectiveness of feasible interventions to reduce plastic pollution by 2040. It found that 78% of the plastic pollution problem can be solved by 2040 using current knowledge and technologies and at a lower net cost for waste management systems compared to business as usual. And importantly research into future technologies could feasibly close the remaining gap to 100%. Still, even with immediate and concerted action, 710 million metric tons of plastic waste would still enter the aquatic and terrestrial ecosystem.
We also need to train a new generation of scientists, leaders and policy-makers to think differently
In December last year, Elena Dieckmann, Chris Cheeseman and other Imperial colleagues published a paper looking some of the practical barriers to transitioning to a circular economy, with a focus on end of life materials. It included issues such as availability of suitable processing technology, regulatory frameworks and the overall economic viability of the transition and how these might be overcome.
Public perception was also a consideration and this is perhaps an area that is sometimes neglected when considering the transition to zero waste. As a population we need a complete change of perspective when it comes to how we view the products and materials we use and this comes with greater awareness and education around the issues involved.
We also need to train a new generation of scientists, leaders and policy-makers to think differently about this and other sociotechnical challenges. Imperial is striving to do this, for example through the award-winning Master’s in Climate Change, Management and Finance, run by the Imperial Business School and the Grantham Institute; and the Transition to Zero Pollution PhD cohort.
More than this though, Imperial is aiming to encourage circular economy thinking amongst all staff and students at the College, irrespective of specialism. As part of I-Explore, for example, all students can study areas of Science, Technology, Engineering, Maths and Medicine (STEMM) from outside of their degree programme, notably including modules on The Management of Natural Resources and Technologies to Combat Climate Change.
Meanwhile, 2018 marked the launch of the Greening Imperial which has seen initiatives such as an end to single-use plastic glasses in catering outlets and a move to 100% renewable for all electricity bought into campus. In 2019 Professor Paul Lickiss became Imperial’s first Academic Leader in sustainability, a post that ultimately aims to create a network of sustainability champions in every department and division in the College and the establishment of a sustainability fund.
Ultimately, for a zero waste future we need new solutions and radical policies, underpinned by excellence in science and engineering – and not a small amount of imagination.
The Forum is Imperial’s policy engagement programme. It connects Imperial researchers with policy makers to discover new thinking on global challenges. Our features provide a shop window into the world leading research taking place at Imperial and provide insight into how it can inform and contribute to public policy debates.