Mining  - the modern way

Plastics have many benefits. Cheap, versatile and lightweight, their importance to daily life is difficult to overstate, and adequate substitutes with the same range of properties aren't easy to find. So why are we wasting so much of this important resource? In the run-up to PRSE next week in Amsterdam, Sustainable Plastics  spoke with Lucy van Keulen, Commercial Director at Umincorp, about that company’s breakthrough in sustainable plastics recycling.

Let’s start with the name of the company, Umincorp. What does it mean exactly?

The name stands for Urban Mining Corporation and it means exactly what we do: we mine raw materials and resources from urban environments. The city is a rich source, far richer than any source in Uganda or Venezuela, where you might want to be sourcing raw materials from.

The idea actually came from a professor named Peter Rem, who leads the Resources and Recycling Group at Delft University of Technology, which is also where both the founders of Umincorp studied. Umincorp is the direct result the concept he developed. As a company, we are focussed on the recovery of plastics from household waste. To reach green commitments, we urgently need to better use our waste as a mine for plastics.

So better resource management, is that the aim?

Resources are key; after all, many of the raw materials we use are finite. Oil, for instance, which is the basis of 99% of all plastics. It’s this realisation that has pushed the EU to start playing a central role in building awareness of the need for better resource management. The EU has formulated a directive calling for Europe to become far less dependent on virgin resources and in pushing for a more sustainable approach to resource use.

Take, for example, the way a laptop is designed. A laptop contains plural rare earth metals. At the end of life, we should not be sending it overseas to a country like Viet Nam to be disassembled or disposed of. No, we need to keep it here, in our own territory. We can recycle and reuse the resources in that laptop right here instead of having to purchase new. We’re depleting the earth of these resources, while we’ve actually already got a lot that we are not using at all efficiently. We need to efficiently recover and reuse what we already have.

The directive you referred to also states that products must be reparable.

Yes, it’s ridiculous today: if the screen of my €700-laptop breaks and it costs €450 to repair and to do so means half of my laptop will need to be replaced, the choice is simple. Instead of replacing the screen, I’ll buy a new laptop.  So, it comes down to design – we need to design products to last longer. 80% of the lifetime of a product is determined during the design stage. It’s time to start thinking about how to design better products for a longer lifetime. The average plastic bottle contains a number of different types of plastic. This makes recycling these bottles rather like trying to recover the original vegetables after making vegetable soup. In fact, multilayer materials, in which the different layers are laminated together, are often impossible to recycle.

What are you doing so differently?

We sort at the flake level, not at the object level, unlike other commonly used technologies. It is a totally different approach. And it took us more than 10 years to develop and refine the technology to a point where it could actually become a viable, feasible separation and recovery technology. In 2018, we were ready to scale up and take it to the market and then planned to build a large-scale factory in Amsterdam.

But finding the funding  proved difficult, as not a single potential investor was willing to take the risk. Finally, our founders used their own money and resources and  together with a joint venture partner – MSN, Milieu Service Nederland – they built the plant in Amsterdam. It was a leap of faith – they had no contract with a waste management company and no support from external parties. That’s the problem with sustainability: we all say we want it, but no one wants to stick their neck out. We did, and now everyone is looking to see how we did it.

Today our plant handles the waste of over 2 million people – the inhabitants of Amsterdam, Rotterdam, Utrecht and The Hague. We can be proud of the leading example that we are nowadays, having successfully shown that plastic household waste can be a feedstock source. Take our tray-to-tray recycling: today our trays from recycled material are currently available in a major grocery store as a packaging material for fruit.

Tell me about your technology: what exactly is Magnetic Density Separation? Why is it a breakthrough in sustainable plastics recycling?

Briefly, MDS technology is a method of separating materials based on their density. It's unique in that it can separate a mixed stream into at least three different output materials, in just one single process step. And it is a radically different approach from traditional methods, leading to 80% less CO2 emission

In what sense, exactly?

We adhere to the scientific approach that says particles must ‘first be liberated, then separated’. In other words, very early on in the process we put everything through the shredder, creating particles consisting of just one type of polymer, unlike the usual approach, in which the separation process first takes place at the ‘object’ level. At object level, the quality of the sorting will always be lower, simply because nearly all pieces of packaging are comprised of more than one type of plastic.

People thought we were crazy, telling us that by shredding the waste stream into tiny pieces we were simply aggravating the sorting problem. However, the strength of our MDS technology is that it can take a mixed stream of flakes and separate this with a very high degree of purity – in a single step. Other approaches cannot do that.

How does it work?

After being collected, the waste collected from Dutch households undergoes an initial separation step during which metals, rigid plastics, flexible plastics, paper and such are all separated out, after which the rigid plastics are sent to us. The initial sorting is a rough process – so what we do is first separate out all the non-target products that have been overlooked. In step two, what we have left is a stream of target recyclables only, which is then put through the shredder, producing flakes. The third step involves washing followed by the MDS step;  a Hugh bath with magnets, filled with a fluid of fine iron particles. These magnets interfere with the process fluid. As the plastic flakes flow through the tank, they separate into different layers that match the densities of the various types of the flakes. PP is the lightest, so these flakes swirl near the top; then comes HDPE, while PET, the heaviest floats along the bottom of the tank. These are the three polymers that we focus on. The technology achieves an amazingly precise level of separation. And unlike the more traditional float-sink separation techniques used elsewhere, our solution can handle all three polymers is a single process step, which traditional methods cannot.

How sustainable is the process?

Compared to traditional mechanical recycling and chemical recycling, we have the lowest CO2 footprint by far - 80% lower compared to conventional methods. This is thanks to our all-in-one approach (sorting and separation in one locations) and high recovery of all incoming materials and high quality of output materials.

PET makes up 50% of all plastics in packaging, mainly as bottles and trays. However, the proportion of waste trays in the PET fraction of the rigid plastic waste stream we receive is rising fast. More difficult to recycle, trays tend to be discarded by most recyclers and incinerated.

We spent almost three years working to develop and improve both our plastic recycling approach and our PET compounding technology and were ultimately successful. Today we are building a new PET compounding line to produce PET compounds, which will be finished by end of this year, enabling us to recover and recycle more materials from our urban mine, i.e., plastic household waste.  And enabling the development of truly circular materials: an ‘old’ tray reincarnated as a new tray and a former shampoo bottle from which a new one is made.

In the near future, packaging will be required to have a certain percentage of recycled content. Is your material suitable for food contact applications?

That is very much dependent on regulations and legislation. For PET – yes, with restrictions. For HDPE and PP, no, that is not possible. The rules state namely that food contact approved recyclate must be derived from minimally 95% food contact originated packaging – and in the case of HDPE and PP, that is simply not the case. Both PP and HDPE are used for so many other applications in addition to food-grade packaging. All sorts of research is going on and papers are being submitted in attempts to change the rules, which are very strict and based on old technologies. The current rules do not enable the innovation needed to make circularity possible.

According to the commitment progress report published by Ellen MacArthur last November, the top ten fast-moving consumer goods companies will need 9 million tonnes of polymers in 2025, in just 3 years’ time, of which 30% is required to be recyclate. That’s 3 million tonnes, while today only around 1.4 million tonnes are produced – how are we going to double that in those three years?

There is going to be an unbelievable shortage of recycled material – especially high-quality recycled material. Two-thirds of packaging is non-food, so let’s start with that. That’s enough of a challenge as it is, without also worrying about producing food-grade recyclate.

What about chemical recycling – as a complement to mechanical?

Well, for me, the problem with chemical recycling is the CO2 footprint, which is huge. Besides that, the technology still in an early stage of development in comparison to mechanical recycling.  Also, to me, it’s very much thinking from the traditional, ‘virgin’ point of view, where perfection is the goal.  Using recyclate demands more flexibility, creativity and another design approach. I think that if the technology for mechanical recycling continues to develop – through the use of scanning and recognition and more traceability through the whole chain - and if the regulations evolve, as well, we should be able to achieve far more. Mechanical recycling is far more interesting, ecologically and economically speaking, than chemical recycling technologies. In my opinion, there is a place for chemical recycling, but mechanical recycling will need to do the biggest part.

How has the market responded to your materials?

To make an impact on the recycling of plastics, it is not enough for us, as recyclers just to do our very best. All the players in the chain need to change, including consumers, brand owners, retailers and designers. We are all dependent on each other, in a way that reflects the vulnerable balance in nature. If designers continue to create hard-to-recycle products or consumers prove unwilling to spend a few extra cents, the concept of the urban mine won’t work.

To reach our goal of packaging-to-packaging recycling, it’s not enough to just sell our flakes and optimise our technologies. We need to be active across the entire chain; we are working to influence brand owners, influence regulations, influence converters, to give people the knowledge and examples to take the right decisions.