"A triumph of technology"

No color, no poison, no stench: A pilot plant of the start-up company IneraTec has produced a regenerative fuel. "We do not see this as a transition technology, but as a very important building block in the field of energy generation"

"Our goal is to build these plants into production maturity and to place them everywhere where renewable energy is produced and where it must be stored," says engineer Tim Böltken.

Ralf Krauter: It sounds like alchemy: Take a pinch of solar electricity, some water and air and create a 100 percent regenerative fuel. With a pilot plant in Finland, developed in the project Soletär, this piece of art has now succeeded. The central component of decentralized liquid fuel production is a compact Fischer-Tropsch reactor in the container format, which the start-up company IneraTec from Karlsruhe has confirmed. Company founder Dr.-Ing. Tim Böltken told Ralf Krauter the background - and how the first 200 liters of fuel appeared, which came out of the plant.

Tim Böltken: This was, of course, a nice feeling, when there was really a very clear liquid simply from the plant, which was generated only from CO2 and hydrogen. You have to think of it as water, so not so colored as conventional, crude oil based fuel, but it is really colorless. It smells different, it is very paraffin-rich. This is because there are no aromatics in this fuel. This also promotes the combustibility of the fuel again. The beauty is, it is also not poisonous. You can touch it and do not have to worry about getting cancer.

"A kind of raw diesel"

Krauter: So that is a hydrocarbon, which could be burned in an internal combustion engine, which already has a similarity to gasoline?

Böltken: It is distillable, the fuel, that is, you can take different routes. You can make gas from this raw fuel, you can make kerosene, you can also make diesel. The fuel coming out of the system is a kind of raw diesel. That is, in the summer, when it is not cold, I can also immediately in my internal combustion engine.

"The heart is our compact Fischer-Tropsch process"

Krauter: Let's talk about this remarkable plant that made this possible. What are the key components of this so-called "baptism" facility in Finland?

Böltken:The heart of this system is our really compact Fischer-Tropsch process. There, a liquid fuel is made from gases, which is then also liquid at ambient temperature and at ambient pressure. In addition to this Fischer-Tropsch process, which we have integrated into a container, one or the other component is still necessary. In this Soletär project, for example, there was an electrolysis that has gained hydrogen from solar water. And there was a so-called CO2 direct-air capture, that is, the CO2 was pulled out with a large filter from the air. And so we had hydrogen and CO2, and this was then introduced into our facility, and fuel was generated from it.

Krauter: The Fischer-Tropsch method, you know perhaps still from the school. It is also used for liquefying coal, for example. They have now modified and made technically even more compact. How long did it take to produce these first 200 liters?

Böltken: The development was mainly carried out by the Karlsruhe Institute of Technology, of course still in our time when we were still students and doctoral students. We have, of course, diligently investigated there by 2013. In 2014 six, seven years of research have already passed, and then we have said that is a cool technology, we can now bring them to market. In this way, we founded the company IneraTec and then developed a reactor and a process in which we can then apply this process decentrally. And you have said it right, Fischer-Tropsch, you know from quite large plants that are operated centrally. We can now use this reactor on a decentralized basis, and of course we were very happy when, in the year 2016, the plant was first set up and approved, and this year, this summer, this campaign is now running and it is within From a week the first 200 liters of fuel drowned out, and in that way was already a triumph of this technology.

"Decentralized systems need decentralized plant engineering"

Krauter: This is a perfectly regenerative fuel, if you will. You just need solar energy, you only need water, and you are fishing for CO2 from the air. What is the limiting factor of this method in terms of capacity and speed of manufacture?

Böltken: We are talking about different aspects with capacity and speed. When you look at chemical plants, you always think immediately in a large technology. We are talking about large industrial parks, such as a BASF in Ludwigshafen or also large refineries. However, renewable energy is often simply decentralized. We have wind parks, we have solar parks, but we also have biogas plants. These decentralized plants, which provide the energy, also require a decentralized chemical plant technology, in order to then convert the gases decentrally locally and store them, for example, in a liquid product. Our goal is to build these plants into production maturity and then put them wherever renewable energy is produced and where it needs to be stored. And in terms of capacity, we have no limits. We are in the process of engineering a plant in the megawatt area, which could then be adapted to larger wind parks, larger solar parks, hydroelectric power plants, where electricity could be generated, for example.

"A really important building block in the field of energy generation"

Krauter: That is, the technology is in principle scalable, and it could well play an important role in the implementation of energy sources, because one could use superfluous electricity to produce fuel.

Böltken: Exactly. It is scalable in the decentralized area. This is why we see this not as a transitional technology, but as a really important building block in the field of energy generation. This is the storage of the energy that we will generate in a renewable way in the future. This is really an efficient alternative for example also against a battery storage. We always talk about fuels, but actually it is hydrocarbons. They have a much higher energy density than a battery. And they have the advantages, they are easy to store, I do not need high pressure, I do not need low temperatures, I can simply fill them in a tank and then use them in an existing infrastructure. You do not have to burn them immediately in an engine. It can also be used as a raw material in the chemical industry to replace petroleum-based components. I can make plastics from it, I can use it for varnishing, but also for the cosmetics industry. So the possible applications are many, and it would be nice if we could place here as an industrial location also our entire industry on a kind of renewable stand.