Circular Economy If You Really Want to Implement the Circular Economy, You Have Think Big
Keeping products in the economic cycle for as long as possible, closing material cycles, avoiding waste (including CO2) — awareness is now wide spread that the Circular Economy is more than “just” recycling. However, the extent of the transformation is only gradually becoming apparent. At Dechema’a Tutzing Symposium, the consensus was: if you really want to implement the Circular Economy, you have think big.
There are many specific technological approaches. But anyone who tries to grasp the Circular Economy — even if only in keywords – as an overall system will quickly find their head spinning from the many perspectives that have to be taken into account: the material view (metals, inorganic raw materials, carbon, etc.), the product view (plastic parts, batteries, wind turbines, etc.) and the question of suitable processes from the very large scale (collection systems, disassembly of components, etc.) to the very small (such as the separation of rare earths). Furthermore, there are multiple interactions between material cycles, which in addition require water and energy to run. What happens in one place has an impact in numerous other places. Describing the Circular Economy as a whole is a mammoth task. A focused look at individual cycles shows where the challenges lie.
Coupling Product Design and Recycling — Sure, But ...
One requirement when it comes to closing the loop is to integrate recyclers into product design. This sounds logical: Those who have to disassemble the product afterwards — whether into components or molecules — know best which “predetermined breaking points” are needed and which material combinations can be easily separated.
However, the concept quickly reaches its limits with many products. The example of batteries is an impressive showcase. Currently, the amount of batteries produced is increasing dramatically, mainly driven by electromobility. At the same time, the material composition is constantly evolving, and a wide variety of cell shapes are being used. A case for “design for recycling” — one would think. But given the lifespan of batteries (if secondary use concepts are included), many of the cells built today will not reach recycling companies for another 20 years or so. So it is far too early for them to deal with the challenges today, let alone build up the corresponding capacities. And the question of which raw materials are to be recovered at all in 20 years’ time, and whether this will be economically viable, cannot yet be answered today.
Where Does the Carbon Come from?
While closing the loop may still seem “simple” in the case of individual metals or phosphate, it becomes highly complex when it comes to carbon at the latest. The peculiarities lie in the diverse shape of the molecules and the hardly manageable number of applications in which carbon plays a role, and in its close interconnection with the energy system.
Nevertheless, some rules of thumb can be established for the carbon cycle as well. For example, it is even more true here than in other places: The most sustainable and cost-effective approach is to prevent CO2 from being produced in the first place. In addition to the use of renewable energy, this also includes the energy efficiency of the process industry, which is currently often pushed into the background. Material recycling also helps to keep CO2 avoidance costs low. These increase with the use of biomass and new processes, and peak with the recovery of CO2 from the air and the use of new fuels.
Particularly for plastics, as one of the largest C-based applications, special attention must therefore be paid to recycling. To do this, the entire processing chain must be taken into account. After all, how much and what kind of recycling is possible depends crucially on the material portfolio. For this reason, not only the performance and price of the material itself should be taken into account in its development, but the recycling possibilities or the parallel development of new recycling processes should also play a role.
However, even if plastics are recycled as much as possible, in the medium term CO2 utilization will have to make a significant contribution. The vision of an economy in which carbon comes primarily from biomass is almost impossible to realize, given the quantities required and the competition for biological resources and arable land. Experts see the share of biomass in the industrial carbon cycle at well below one-third, even in the long term. Instead, “perpetual” CO2 point sources such as cement plants and the direct extraction of CO2 from the air (“Direct Air Capture”, DAC) will have to supply the raw material. This makes the further development of CO2 capture and purification technologies all the more important.
Complex Decision Trees
Where technologies are so costly and resources are scarce, the pressure to select the right option for their use intensifies: Where are carbon-based energy sources necessary (for energy density or logistical considerations, for example), and where do batteries perform better? Is biomass considered only as a carbon source for pyrolysis, or can nature’s synthesis input be used to add value? The decision paths are complex and require evaluation systems that provide criteria that are as objective as possible. These include life cycle analyses, but their informative value depends heavily on the indicators chosen and the definition of system boundaries. And even the supposedly “hard numbers” often require the formulation of target hierarchies, because not all parameters can be optimized simultaneously.
New Competition for Resources
One, if not the, key to closing the loop is energy. With enough renewable energy — stored preferably in green hydrogen — almost anything can theoretically be achieved. But where is all this renewable power going to come from? The chemical industry alone would need around 600 TWh of renewable energy for greenhouse gas-neutral production — that’s more than Germany’s current total energy demand. At the same time, many are competing for this rare commodity: The steel industry is using hydrogen instead of coke for reduction, and glass, cement and other energy-intensive industries are also looking at how they can operate CO2-neutral. And that doesn’t even include heat supply and mobility.
Getting Society on Board
Who is to decide where the hydrogen goes? New social negotiation processes are necessary — firstly, to significantly accelerate the expansion of renewable energies, and secondly, to clarify distribution as long as not all needs can be met simultaneously. This also includes the question of where consumer behavior may need to be changed. Taking the example of mobility, it quickly becomes clear that replacing all internal combustion engines with e-drives only solves part of the problems and at the same time creates new ones, for example in terms of raw material requirements for batteries or the charging infrastructure. The e-SUV is not the solution.
society at large must be informed and involved.
But this also means that society at large must be informed and involved. What’s more, the active participation of many is needed to develop technical as well as economic and social solutions. For this to succeed, communication must not only be problem-driven. Fascination with new things and inspiration by good examples can motivate (not only) young scientists to actively participate in implementation. They can also increase the willingness to try things out and correct them if necessary, instead of waiting for the supposedly perfect solution and doing nothing until it comes along.
It Only Works Globally
If we are really serious about the Circular Economy in terms of global climate and resource protection, there is no getting around it: the transformation requires a global approach. “Global” in several respects: neither one sector nor the industrial system can implement the Circular Economy alone. This is due to the many interdependencies and competitions, but also to the need to name and discuss conflicting goals. The assessment of which need takes precedence or which concessions must be made in terms of prosperity, landscape protection or geopolitical positioning cannot be made within the industry or the natural sciences.
Global, however, also means international. Starting with location requirements — where can both renewable energy and water for hydrogen production be found? — to the ethical question of participation to practical considerations in sustainability labels, international cooperation is essential. Climate change is a global problem, and it can only be addressed globally.
We can’t flip a lever and change our economic system from one day to the next. Nor can we shut everything down and start again in a few years in a circular fashion. The transformation toward a circular economy must take place during ongoing operations and be economically bearable. Reliable framework conditions, openness to technology, entrepreneurial spirit, open discussions and the ability to compromise are necessary to master this challenge.