Prof. Dr. Bernd Friedrich is the director of the Metallurgical Process Engineering and Metal Recycling at the Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen in Germany, a leading research centre for green metallurgy.
Could you please describe your research and institution?
Bernd Friedrich: Our institute at RWTH Aachen is, I would say, one of the biggest institutes here in the faculty. We work in the field of process metallurgy and metal recycling. So metal recycling is our DNA; and that research is focused on end of life materials recycling from smartphones or batteries or all kinds of electronic devices, as well as some types of industrial waste.
The periodic system is quite rich in in metals, so the variety of projects is enormous here. They range from rare earth metals to steel alloys to precious metals like silver and gold, and those used in electronics such as copper, lead, tin, zinc, and so forth. I have roughly 35 researchers here in my team, and the same number of technicians.
We have maybe one of the largest units in Europe for scaling up recycling processes. Battery recycling is very big at the moment, so there are several startups that are trying to take our results to a production scale.
We are looking for green technologies with the lowest harm to our environment and our social surroundings. Our “brand” is green metallurgy in Europe.
How does your work relate to the kind of recycling people are more familiar with at home – such as sorting out paper and plastic?
Bernd Friedrich: Let’s take the smartphone as an example: If you look into the recycling chain of a smartphone, you have different problem points.
The first point is the logistics. People don’t want to bring the smartphone back to a recycling area. This is a transportation effect, and it’s an important aspect, but not what we work on here. We are not looking into the logistics side.
Assuming you obtain the smartphones and bring them to a centralised recycling area, the next step will be sorting. That means the opening of the smartphones and the separation of the individual parts: they are sorted by type into individual ‘concentrates’. You have concentrate of loudspeakers or vibrator elements or batteries.
These concentrates are the starting point of our research. First, we separate metal parts from plastics. This can be done in two ways: one way is using a chemical solvent to dissolve all the plastics, leaving only the metals; another way to achieve the same is through thermal conditioning in a furnace, not burning but decomposing the plastic into carbon and hydrogen.
From there, with the metals separated out, we have again two options: one is using a smelter furnace to melt down and separate the different metals. This separates, for example, copper and gold from the rest, which go into another solid ‘mineral product’.
This mineral product contains rare earth metals that are then separated out chemically.
The alternative to smelting is to do the whole process chemically: you throw the whole concentrate into an acid and dissolve everything into a multi metal solution. From there, step by step, you separate out the useful elements.
Such a process is a very dynamic system because every generation of smartphone has a different design and contains different metals.
Given that complexity, what are the difficulties and challenges of actually implementing these new methods from a technical point of view?
Bernd Friedrich: To begin with, we want to create processes that have a minimum amount of new waste. The second point is minimising the resource demand for the process. The third point is maximizing the recovery yield of the individual methods.
Of course, that depends on the value of the metals, because the higher the purity required, the more steps you need. Finally, we want is to fully separate out the metals. So that nickel goes in the nickel product chute, and not in the copper one, and so on.
Achieving all these goals in one process is quite complicated, and this is only the technical part. Then, you also have the economic side: we want to minimise the cost of every process. This means you need to work in an interdisciplinary way.
What is the role of recycling regulations?
Bernd Friedrich: Regulation, I think, is necessary – otherwise things will not happen. For example, if we have a regulation on battery recycling, say, to reach 80% of lithium recovery from lithium ion batteries, this directive would trigger new thinking in the companies that manufacture them.
It also has to do with money, and who will pay. I think the end user will always pay, in the end. You can make an analysis of how much metal is in, say, a battery. You can go into the day-to-day price list: what’s the price for nickel? Cobalt? Gold? Then you can sum these amounts up and find the metal value of a given product as it’s recycled. From this value, you have to subtract the processing costs.
If the metal value is higher than the processing costs, then the recycler will pay the consumer. But, most likely, it’s the other way around, and there will be some additional fee for recycling, which is why it is necessary to implement regulation to make it happen.
So the regulation helps set which metals are actually worthwhile to recycle?
Bernd Friedrich: Yes, exactly. Without regulations, only some metals might be worth recycling.
Europe is trying to increase its supply of critical raw materials. What is the role of these recycling technologies in meeting those goals?
Bernd Friedrich: Of course, we will never cover the complete demand with recycling.
It’s impossible, especially not in a rising economy, because the recycling may take place several years after the product has gone through its complete lifecycle.
We still have to import raw materials from outside, not only because recycling is ‘delayed’ in this way, but also because people don’t want to have a mine close to their houses. The social acceptance of heavy metal industry and mining industry is not very high, especially not [here] in Germany.
What would you say to a consumer who doesn’t like the idea of paying more for a smartphone so that it can eventually be recycled? What should people know about these technologies?
Bernd Friedrich: There is not enough knowledge about recycling in general to begin with.
Some people say, “Why shall I separate glass at home if the people outside mix it back?” There are stories here of reluctance like that.
An example from our town: Aachen was the second German town, after Freiburg, in signing the circular city declaration. I delivered a speech on that occasion and came in contact with the town mayor here, who asked me what could be done to promote the circular economy within the city.
I proposed to take the example of the smartphone again and create a ‘week of recycled smartphones’ as a local event; with flyers, and advertisements. I would build a big Plexiglas tube in the main square, and everybody in Aachen could throw their old smartphone into that. We could have seen how it was filling up over the week. As Aachen University, we would stand around with posters showing how we would recycle those materials safely and how much metal had been recovered at the end.
Nothing happened. Nothing happened because they thought this idea was too much work.
Instead, we made a small pilot inside the university. Within one week, I had more than 200 smartphones here, only from a few messages around the campus.
To me, this shows that if you reach the people and if you have somebody really doing good communication, it will work.
Then, the appetite is there, but perhaps it needs a bit more public visibility in order to get going?
Bernd Friedrich: Of course. It should be easy to bring the old products to be recycled. Now you sometimes have to drive 5 kilometres to the nearest recycling point. Nobody will do that, since phones are small.
If you have a party at home on the weekend and you drink 20 bottles of red wine with your friends, then you have a space problem – it’s not the same with small phones and electronics. That means the collection system for recycling needs to be more convenient to motivate people.
What is the environmental impact of the recycling process itself? What kind of emissions or waste does it produce?
Bernd Friedrich: Of course there’s no process without any by-products, that is impossible. Therefore, you have to be very careful – catching the by-products, collecting them, treating them, and avoiding that they reach our surroundings.
That means, for example, that, if you run a furnace, you will create a slag and you will create gas with dust in it. You can process both further, because they might still contain metals in them. But there is no really zero waste process, because at the very end, the last 1% is so expensive to process.
We try to minimise the waste, but we can’t eliminate it entirely. Therefore, we call our process “near zero waste metallurgy.” That means we will certainly emit some gases, we will emit, some solids, some wastewater; but that must be under control and minimised, we also have to dispose of that safely if it is hazardous.
The total emissions for any product depend on its specific life cycle. For example, for some solar cells, if you calculate the energy to produce it and recycle it, you find it is more than might ever be generated by the solar cell. This depends on the energy source used to manufacture it.
If you produce the silicon for the solar cell in a country where there’s water based energy, that silicon is ‘green’ as opposed to a cell manufactured in a place where the energy grid is carbon-based. So, the recycling phase is only one of many to consider when you think about the lifecycle of a product.