- Hydrogen is considered to be the fuel of the future. Our economic system still lives from the use and combustion of carbon products – oil, natural gas, coal.
This creates CO2, which is responsible for the greenhouse effect and thus for global warming. It is the task of all of humanity to implement decarbonization – i.e. the abandonment of carbon products – as quickly as possible in order to mitigate the consequences of climate change. At the Jülich campus of the Aachen University of Applied Sciences, a method is now being researched as part of a dissertation that can contribute to the widespread use of hydrogen as a fuel for our economy.
The principle of the production of hydrogen is easy to explain: water is split into hydrogen and oxygen using energy – the so-called electrolysis. If renewable energies are used to produce the hydrogen, the entire process is CO2-neutral, as only water vapor is produced when the hydrogen is burned. For example, hydrogen can be used very efficiently in fuel cells in vehicles or buildings. But there is one problem: it is difficult to store and transport hydrogen. Decentralized production therefore opens up interesting possibilities for the widespread use of hydrogen.
This is where a process comes into play that researchers on the Jülich campus of the Aachen University of Applied Sciences use. In an interdisciplinary project entitled “Electrically amplified microbial hydrogen production” (eBioH2), they are working on generating hydrogen from organic material – for example grass or straw. The three Jülich departments chemistry and biotechnology, medical technology and industrial mathematics, and energy technology are involved. The main actors are Prof. Dr. Nils Tippkötter with his colleagues Dr. Simone Krafft and Berit Rothkranz as well as Prof. Dr. Torsten Wagner and Prof. Dr. Isabel Kuperjans.
At first glance, this process is comparable to the generation of biogas. A fermentation process takes place in a bioreactor. The conventional biogas process produces methane, which can be used to generate electricity and fuel. “We use microorganisms that can convert biogenic residues directly into hydrogen at 70 to 80 degrees Celsius,” explains Prof. Tippkötter.
In the laboratory, doctoral student Berit Rothkranz is currently working on optimizing the parameters. She researches the influence of pH value, temperature and pressure on fermentation. “We have to convert the equipment because the temperature is higher than in conventional reactors,” says the young researcher. She uses a chromatograph to examine the composition of the resulting gas mixture and thus the process quality.
The Jülich departments and institutes contribute their respective competencies to the research work. The NOWUM-Energy institute has extensive experience in the analysis of biogas processes. The director of the institute, Prof. Kuperjans, says: “We can transfer the results of our previous work to the new process.” This applies, for example, to the question of how the organic raw materials have to be in order to guarantee a stable fermentation process. The Institute for Nano- and Biotechnologies (INB) provides valuable support in the areas of measurement technology and control. “The process works very well on a laboratory scale,” explains INB employee Prof. Wagner, “the next step will be to reliably produce hydrogen on a larger scale through close monitoring.”
The plans of the eBioH2 research team also go in a different direction. If you also feed electrical energy into the fermentation process via electrodes, hydrogen production increases. It would therefore be conceivable to use the process to store energy – an appealing idea, especially in combination with the use of renewable energies. “We can absorb excess electrical energy as needed and store it in the form of hydrogen,” says Prof. Tippkötter.
At the same time, the scientists are looking for partner companies from industry that want to use the process. Agriculture would be a possible field of application on a smaller scale. There are organic residues there that could be fermented, and vehicles and machines could also run on hydrogen. But energy-intensive industries – for example in the chemical industry, in steel and cement production – are likely to rely on hydrogen as an energy carrier in the future. With the research project, the team wants to keep its finger on the pulse – this is how the federal government set the framework for action for the subject area with its national hydrogen strategy. “We can offer a component here,” believes Prof. Tippkötter.
The project is funded by the Ministry of Culture and Science of the State of North Rhine-Westphalia with grant number 005-2105-0044.
Photo: FH doctoral candidate Berit Rothkranz checks the condition of the substrate – FH Aachen / Arnd Gottschalk – FH Aachen