Interview Water as a Location Advantage
The process industries must establish efficient and circular processes that do not require fossil raw materials and energy. But what does that mean for the careful use of water as a resource? We talked about this with Dr. Thomas Track, Head of Dechema’s Water Management Department.
Mr Track, without water, there is no industry. In recent years, even Germany has had to realize that water is not infinitely available. How do you assess the development?
Dr. Thomas Track: Water is clearly a production factor for industry — in many respects. The drought year of 2018 limited the availability of water, and rivers such as the Rhine were no longer navigable in some cases. This has led to logistical problems. But cooling was also affected. Therefore, the industry also has to deal with climate change and its consequences. After all, their investment cycles are quite long. You have to think about safe and sustainable water supply and disposal. Here, Germany still has a locational advantage at the moment.
But even in Germany, water is not an infinite resource, is it?
Track: Water scarcity is a regional issue in Germany. In times of low precipitation or increasing demand, competition for use arises. This is what we also call water stress. This has very different manifestations in Germany.
Can you say more about that?
Track: In eastern Germany, for example, agriculture competes locally with municipal supply when availability is low. In some coastal regions, on the other hand, industry is an important water user in addition to agriculture and municipalities. Here, however, it is not so much the quantity but rather the water quality that is critical. Salt water can repeatedly infiltrate groundwater and surface water and impair its quality. In coastal areas, freshwater resources are therefore very sensitive to withdrawals.
What can industry do to use water efficiently?
Track: Water is one of many production factors. So in addition to the management of water resources, industrial perspectives also play a decisive role. If the orientation of production changes, water management must also adapt to these developments. We therefore asked ourselves which trends will determine production in the future. We see five challenges, of which water stress is only one.
What are the other four challenges?
Track: Decarbonization, circular economy, zero pollution and biotechnological processes will determine the development of the process industry. These perspectives require new concepts for sustainable and efficient use of water.
To what extent does decarbonization affect water management?
Track: Decarbonization is a task that is high on the agenda in the industry. In the EU, we have set ourselves the goal of being CO2 neutral by 2050. Industry is also playing its part in this and is a driver. It is developing and using technologies to achieve these goals. At the same time, energy consumption must be reduced. And this is the crux of the matter: on the one hand, we want CO2 neutrality and, on the other, we want to conserve water resources, which requires technology and thus energy. This is a conflict of objectives that the industry has to face up to and is already doing so.
Where does water management need to be considered in the circular economy?
Track: The European Union’s Green Deal asks us, among other things, how we can close cycles. Of course, this applies to the water cycle itself. But above all, other material cycles — for example, plastics recycling. We need water for these processes. And therefore also efficient water management. In addition, the focus on zero pollution is driving the reuse and recycling of water. After all, any water that does not leave the plant eliminates the potential risk of emitting waste or pollutants into the environment.
That brings us to the next trend: zero pollution. What are the challenges for managing water?
Track: Substances concentrate when we circulate water, for example in cooling processes. They have to be removed, as do ingredients from production wastewater if we want to reuse it. The resulting concentrates, most of which contain salts, are initially residual materials that have usually had to be disposed of up to now. So far, there are business cases for their reuse only in very selected cases. In most cases, it is simply not profitable to process the waste materials accordingly.
Do you have an example where reuse is already working?
Track: Recovered salts can be reused in selected cases. For example, Covestro treats industrial wastewater from the production of polycarbonate in a pilot plant at the Krefeld-Uerdingen site and uses the saturated saline solution for chlorine production.
What challenges does biotechnology pose for water management?
Track: Wherever possible, industry is trying to replace classic chemical-physical processes with biotechnological ones. Most of these processes take place in aqueous media, for example fermentation processes. Here, too, we have a conflict of goals: On the one hand, industry is trying to produce more efficiently with the help of biotechnology. On the other hand, there is the energy- and cost-efficient use of this water. For example, the question of how to efficiently separate the valuable substances from the fermentation broths or how to process the fermentation broths so that they can be reused. These questions must be considered from the outset.
Where are the energy guzzlers in these processes?
Track: Large quantities of water are moved during processing. Moving means pumping. Because of the high volumes, efficient pumps are an enormous lever for energy-efficient processes. In addition, a comparatively small proportion of recyclables has to be separated from these volumes.
A lot has happened in pump technology. Do you still expect major efficiency improvements?
Track: That’s right. Pumps have certainly become extremely efficient in recent years. Further energy savings will probably depend less on the pump itself, but rather on the question of how to use the pump efficiently in the overall system. The same applies to membrane processes and other separation technologies. In our view, the greatest levers for efficiency are at the interfaces — i.e. in an integrated approach to production and water management.
The central element of decarbonization is hydrogen. In addition to green electricity, water is also needed for its production. Where should it come from?
Track: That ties in with the point about water security and water stress. The production of green hydrogen makes most sense where a lot of electricity is generated from renewable sources. For example, wind energy in coastal areas. However, qualitatively usable water resources are very sensitive and their availability is limited. Therefore, integrated solutions are needed to meet the water demand for hydrogen production. Appropriate water management must also be developed for offshore hydrogen production. This applies all the more if other value-added processes such as Power to X are added. After all, sensitive ecosystems such as the Wadden Sea in the North Sea must be protected.
Does water stress get even worse when electricity is generated from solar energy?
Track: Not so much in Germany. But to meet our hydrogen needs, we need to look for alliances with other countries or regions that produce hydrogen or other feedstocks using electricity from photovoltaics in addition to wind. These are regions with high solar irradiation. Unfortunately, this is often accompanied by very limited water availability. In principle, efficient water management must be taken into account when considering hydrogen.
Which regions or countries are you thinking of?
Track: In Egypt and the Maghreb states, investments are being made in seawater desalination and hydrogen production. In addition, the topic is currently being pushed strongly in Namibia. And Australia is also very active in the field of green hydrogen.
Does it always have to be seawater desalination in arid regions? Or are there other sources?
Track: Also, but not exclusively. Integrated approaches should be pursued where possible. Because hydrogen production is always part of an infrastructure. There are usually other industrial plants as well as municipal or urban structures. Both produce wastewater. Consideration can be given to the extent to which treated municipal wastewater can be used as raw water for industry, for example.
Thank you very much for the interview.