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The calculable twin

With the "Biogas Digital Twins" research project, HFU is helping farmers from the Black Forest to operate biogas plants more economically

The calculable twin (I22841)

So that biogas plants can be operated more economically, research is being conducted at HFU on their "digital twin." Image pixabay/ 1815691

Professor Dr Volker C. Hass has a wonderful description for his profession: "As a 'biochemical engineer,' you convert substances that you can't count," he says, raising his cup, "The same as making coffee, actually." But let’s start at the beginning: this is about bioeconomics - finding processes to use renewable biological resources even more efficiently. "In the bioeconomy, you're trying to use biologically produced, renewable raw materials to develop products, and new biological ideas," Hass explains, "so it's revolutionary because the bioeconomy will transform production systems and chains, moving completely away from fossil raw materials!"

The bioeconomy brings about sustainable economic activity

We can develop entirely new ideas and concepts in this area, reports Hass, who teaches in the Faculty of Medical and Life Sciences at HFU in the Sustainable Bioprocess Technology (NBT) programme and who also heads the Institute of Applied Biology (IANB). Lubricating oils made from plants, cancer drugs produced using a bioreaction technique similar to that used in yeast production – sustainable and resource-efficient processes are everywhere, Hass says.

Making renewable biological resources predictable

"The problem with using biogenic raw materials, is that the quality is not consistent," Hass says, pointing out that biogenic raw materials are not extracted in just one place, "they are collected from a variety of sources throughout Europe." The quality varies – influenced by the seasons, among other things. "Winter straw has different properties than summer straw when used in a power plant," Hass says. So he makes biological resources more predictable – literally, by calculating. "My specialty is – I can reproduce these processes mathematically," Hass says.

Digital twins for the biogas plant

For example, in the "Biogas Digital Twins" research project, which has just been approved by the Baden-Württemberg Ministry of Food, Rural Areas and Consumer Protection. The aim here is to optimise the operation of a real-life biogas plant. Professor Hass will translate the plant into numbers. In a kind of "virtual biogas plant," he assigns line-length formulas to the individual steps that take place in the fermenter, the secondary fermenter or the fermentation product stores. This digital twin not only shows what is currently happening in the biogas plant – the link to the plant also allows changes to be tried out on the computer first (How much more slurry? How much more manure should be added? What does this new mix change?), then to be transferred to the real plant. "Biogas plants could also use organic waste if the operating behaviour could be better calculated and they could be operated more flexibly," says Professor Hass.

New biogas simulators are also used in teaching

The digital twin can calculate 500 times faster than the biogas plant actually runs in reality. This also makes evaluations faster, and yet it can sometimes be tricky. "Sometimes we have to intervene, so then we have to be 500 times faster, too," laughs Hass. What he finds particularly useful about the "Digital Twins" project is that it allows a seamless combination of research and teaching. "We can use the simulators to train students who will later be able to operate such systems. That's a very strong incentive for me." he says, "It's worthwhile to map it out like this, because the students get immediate feedback – they can try things out on the digital twin and learn directly from their mistakes."