Press releases

FRANKFURT/KASSEL/SAARBRÜCKEN. How can the enormous amounts of electricity generated through offshore wind power be temporarily stored on site? Until now there was no answer to this question. After several years’ research work, the StEnSea project (Stored Energy in the Sea) funded by the Federal Ministry for Economic Affairs and Energy is now entering the test phase. In the framework of this project, IWES, the Fraunhofer institute in Kassel specialized in energy system technology, is now developing to application level the “marine egg” invented by two physics professors at Goethe University Frankfurt and Saarland University in Saarbrücken.

A model on the scale of 1:10 with a diameter of about three meters was brought to the ferry terminal in Constance on 8.11.2016 and lowered on 9.11.2016 to a depth of 100 meters about 200 meters from the shore in Überlingen. It will now be tested for four weeks: “Pumped storage power plants installed on the seabed can use the high water pressure in very deep water to store electrical energy with the aid of hollow spheres”, explains Horst Schmidt-Böcking, emeritus professor at Goethe University Frankfurt. To store energy water is pumped out of the sphere using an electric pump and to generate power water flows through a turbine into the empty sphere and produces electrical energy via a generator. Together with his colleague Dr. Gerhard Luther from Saarland University, Professor Schmidt-Böcking filed a patent for their principle for offshore energy storage in 2011, just a few days before the Fukushima disaster.

The two inventors remember: “The rapid practical realization of our idea is actually thanks to a newspaper article in the FAZ. Georg Küffner, the technology editor, presented our idea for energy storage to the general public - as chance would have it on the 1^st of April 2011. Lots of readers doubtlessly thought at first that it was an April Fool hoax, but experts at Hochtief Solutions AG in Frankfurt immediately recognized the idea’s hidden possibilities. Within a couple of weeks we were able to set up a consortium for an initial feasibility study with Hochtief’s specialists for concrete structures and the experts in marine power and energy storage at IWES in Kassel, the Fraunhofer Institute for Wind Energy and Energy System Technology”, recall Schmidt-Böcking and Luther.

Once the concept’s feasibility had been proven, the Federal Ministry for Economic Affairs and Energy subsequently funded the StEnSea project so that the innovative pumped storage system could be further developed and tested on a model scale. It is now entering the test phase. Project Manager Matthias Puchta from Fraunhofer IWES summarizes the project’s successes to date: “On the basis of our preliminary study, we carried out a detailed systems analysis with a design, construction and logistics concept for the pressure tank, developed a turbine-pump unit, examined how to connect the sphere to the electricity grid, calculated profitability and drew up a roadmap for the system’s technical implementation.”

He continues: “The four-week model trials on the scale of 1:10 are starting now in Lake Constance. We will run various tests to check all the details concerning design, installation, configuration of the drivetrain and the electrical system, operation and control, condition monitoring as well as dynamic modeling and simulation of the system as a whole.”

IWES Head of Division Jochen Bard, who has been involved in marine power research for many years at both national and international level, explains: “With the results from the model trials, we want first of all to look more closely at suitable sites for a demonstration project in Europe. We are aiming at a sphere diameter of 30 meters for the demonstration-scale system. At the moment that’s the most practical size in terms of engineering. What’s already certain is that the system can only be used economically in the sea at depths of about 600-800 meters upwards. Storage capacity with the same volume increases linearly with the depth of the water and at 700 meters is about 20 megawatt hours (MWh) for a 30 m sphere.”

He continues: “There is great potential for the use of marine pumped storage systems in coastal areas, in particular near the coast in highly populated regions too, for example in Norway (Norwegian Trench). But Spain, the USA and Japan also have great potential. With a storage capacity of 20 MWh per sphere and standard technology available today, we can envisage a total electricity storage capacity of 893.000 MWh worldwide. This would make an important and inexpensive contribution to compensating fluctuations in electricity generation from wind and solar power.”

Media contact: Uwe Krengel, Tel. +49(0)561-7294-319 (or -345); email: uwe.krengel@iwes.fraunhofer.de

Further information: Dr. Horst Schmidt-Böcking, Tel. +49(0)69-798-47002 or +49(0)6174-934097; email: hsb@atom.uni-frankfurt.de

FRANKFURT. Microbes are already used on a wide scale for the production of fuels and base chemicals, but for this most of them have to be “fed” with sugar. However, since sugar-based biotechnology finds itself in competition with food production, it is faced with increasingly fierce criticism. Carbon dioxide has meanwhile become the focus of attention as an alternative raw material for biotechnological processes. Goethe University Frankfurt has now taken charge of a collaborative European project, the aim of which is to advance the development of processes for microbial, CO₂-based biotechnology. The project will be funded over the next three years with two million Euro.

“This application-oriented work is the logical continuation of our successful endeavours over many years to understand the metabolism of CO₂-reducing acetogenic bacteria. We can now start to steer their metabolism in such a way that they produce valuable substances and fuels which are interesting for mankind”, says Professor Volker Müller, professor at the Institute of Molecular Biosciences of Goethe University Frankfurt. He is coordinating this transnational project in the framework of the “Industrial Biotechnology” European Research Area Network (ERA-NET), within which the German research groups are financed by the Federal Ministry of Education and Research. This means that Goethe University Frankfurt now plays a pivotal role in the development of a next-generation technology.

The special group of acetogenic bacteria converts carbon dioxide (CO₂) in a fermentation process which is independent of light and oxygen. The bacteria use hydrogen (H₂) or carbon monoxide (CO) or a mix of both (synthesis gas) as a source of energy. However, the bacteria produce very little cellular energy in this metabolic process. This drastically limits the product range possible with gas fermentation, so that at present only acetic acid and ethanol can be manufactured on an industrial scale. That is why the collaborative European project has set itself the objective of genetically modifying suitable acetogenic bacteria in such a way that these energetic barriers can be overcome. Partners in the consortium are Goethe University Frankfurt as well as the universities in Ulm, Göttingen and La Coruna. ArcelorMittal, the largest steel manufacturer worldwide, is the industrial partner.

This microbial, CO₂-based biotechnology could in future be an environmentally friendly alternative for the reprocessing of industrial waste gases rich in energy and carbon and reduce our dependency on crude oil. The microbial fixation and transformation of CO₂ into raw materials produced biologically additionally makes it possible to reduce greenhouse gas emissions.

A diagram can be downloaded from: www.uni-frankfurt.de/63820642

Acetogenic (acetic acid-producing) bacteria produce acetic acid or ethanol from H₂ + CO₂ or CO. Energy is released in the form of ATP (adenosine triphosphate) in the process. The synthesis of other products interesting for industry from the intermediate product acetyl-CoA, however, also uses up ATP. The aim of this project is to alter the energy balance of the bacteria by means of genetic modification in such a way that the production of such energy-consuming compounds will also be possible.

Further information: Professor Dr. Volker Müller, Institute of Molecular Biosciences, Riedberg Campus, Tel.: ++49(0)69-798-29507, VMueller@bio.uni-frankfurt.de.

FRANKFURT. When new particles develop in the atmosphere, this influences cloud formation and with that the climate too. Since a few years, these complex processes have been reproduced in a large air chamber within the CLOUD experiment at CERN. Researchers have now used the results for the first time to calculate the production of aerosol particles in all the Earth’s regions and at different heights. The study published in the journal “Science”, in which researchers from Goethe University Frankfurt were involved, deciphers the role of the various chemical systems which are responsible for particle formation. They also determined the influence of ions which develop through cosmic radiation.

Soot particles, dust lifted up by the wind or sea spray account for only some of the particles in the atmosphere. Others develop from certain trace vapours, for example when individual sulphuric acid and water molecules cluster as tiny droplets. This formation of new particles is known as nucleation. Clouds are formed by water condensing on the larger aerosol particles or what are known as cloud condensation nuclei. The more cloud droplets develop, the more sunlight is reflected back into space. Climate models show that the additional particles caused by human activity produce a cooling effect which partially offsets the greenhouse effect. It is, however, less than previously assumed.

Aerosol particles from sulphuric acid and ammonia emissions

The model calculations presented in “Science” prove that about half the cloud condensation nuclei in the atmosphere originate from nucleation. In the atmosphere today, particle formation is dominated almost everywhere by mechanisms where at least three chemical components must come together: apart from the two basic substances, i.e. sulphuric acid and water, these are either ammonia or specific organic compounds such as oxidation products from terpenes. Close to ground level, organic substances from natural sources are important, whilst ammonia plays a key role higher up in the troposphere. Ammonia and sulphur emissions have increased considerably over the past decades as a result of human activities.

11-year solar cycle has scarcely any influence

CLOUD has also investigated how the 11-year solar cycle influences the formation of aerosol particles in our present-day atmosphere. The model calculations show that the effects as a result of changes in ionisation through the sun are too small to make a significant contribution to cloud formation. Although the ions are originally involved in the development of almost one third of all newly formed particles, the concentration of the large cloud condensation nuclei in the course of the 11-year cycle changes by only 0.1 percent – not enough to have any sizeable influence on the climate.

Cooling effects 27 percent less than expected

The CLOUD team has also presented first global model calculations for aerosol formation caused without the involvement of sulphuric acid and solely through extremely low volatile substances of biological origin (Gordon et al., PNAS). According to the findings, this process contributed significantly to particle formation above all in the pre-industrial atmosphere, since at that time far less sulphur components were released into the atmosphere. The number of particles in the pre-industrial atmosphere is now estimated to be far greater through the additional process than was shown in earlier calculations. The model calculations, which are based on data from the CLOUD experiment, reveal that the cooling effects of clouds are 27 percent less than in climate simulations without this effect as a result of additional particles caused by human activity: Instead of a radiative effect of -0.82 W/m² the outcome is only -0.60 W/m².

E.M. Dunne, et al., 2016: Global particle formation from CERN CLOUD measurements, Science First Release, DOI: 10.1126/science.aaf2649

This article appeared online via First Release in Science on Thursday, 27^th of October 2016. http://science.sciencemag.org/cgi/doi/10.1126/science.aaf2649

H. Gordon, et al., 2016: Reduced anthropogenic aerosol radiative forcing caused by biogenic new particle formation, PNAS, 113 (43) 12053-12058; published ahead of print on the 10^th of October 2016, DOI:10.1073/pnas.1602360113
http://www.pnas.org/content/113/43/12053.abstract

A photograph can be downloaded from: http://www.muk.uni-frankfurt.de/63775996

Further information: Prof. Dr. Joachim Curtius, Institute of Atmospheric and Environmental Sciences, Riedberg Campus, Tel.: ++49(0)798-40258, curtius@iau.uni-frankfurt.de

FRANKFURT. Professor Maria Roser Valenti has been elected as a fellow of the American Physical Society (APS) in the "Division of Computational Physics". She was awarded this high distinction for her contribution to the microscopic understanding of electronically strongly correlated materials, which include high-temperature superconductors. To access these highly complex materials she uses a combination of various theoretical approaches.

Professor Enrico Schleiff, Vice-President of Goethe University Frankfurt: "We congratulate the American Physical Society on this decision as Ms. Valenti is a recognized expert in the field of Theoretical Condensed Matter Physics. She unites all the characteristics of an excellent researcher: she is a constantly driving force for creative ideas, is engaged in international projects at the highest scientific level, devotes herself to her discipline both within and outside the University and is a role model for young academics. She will breathe her own new vigour into the APS, just as she did at Goethe University during her time as vice-president."

Maria Roser Valenti studied Physics at the University of Barcelona and gained her doctorate in 1989. From 1990 to 1991 she was a post-doctoral researcher at the University of Florida in Gainesville. She then became a research associate at TU Dortmund University where in 1997 she began her habilitation with a grant from the German Research Foundation (DFG - Deutsche Forschungsgemeinschaft). In 1999 she moved to Saarland University and completed her habilitation one year later. In 2002 she was awarded one of the prestigious Heisenberg scholarships of the German Research Foundation, which prepares early career researchers for a long-term professorship. In 2003 she became professor at the Institute of Theoretical Physics of Goethe University Frankfurt. From 2009 to 2012, the mother of three children was vice-president of Goethe University. Her research work focuses on the quantum mechanics of materials. She develops theoretical methods to describe unconventional superconductivity, frustrated magnetism, exotic spin liquids or systems with phases with non-trivial topology, among others.

With over 50.000 members worldwide, the APS is the second largest association for physicists. (The largest is the German Physical Society (DPG - Deutsche Physikalische Gesellschaft)). The APS was founded in 1899 with the goal of advancing the knowledge of physics and fostering the next generation of researchers. It is regarded as a great honour to be elected as a fellow. Only those researchers are taken into consideration who have made a significant contribution to basic research or contributed substantially to the development of scientific or technical applications.

Hydrogen (H₂) is an extremely simple molecule and yet a valuable raw material which as a result of the development of sophisticated catalysts is becoming more and more important. In industry and commerce, applications range from food and fertilizer manufacture to crude oil cracking to utilization as an energy source in fuel cells. A challenge lies in splitting the strong H-H bond under mild conditions. Chemists at Goethe University have now developed a new catalyst for the activation of hydrogen by introducing boron atoms into a common organic molecule. The process, which was described in the Angewandte Chemie journal, requires only an electron source in addition and should therefore be usable on a broad scale in future.

The high energy content of the hydrogen molecule meets with a particularly stable bonding situation. It was Paul Sabatier who in 1897 detected for the first time that metals are suitable catalysts for splitting the molecule and harnessing elementary hydrogen for chemical reactions. In 1912 he was awarded the Nobel Prize for Chemistry for this important discovery. The hydrogenation catalysts mostly used today contain toxic or expensive heavy metals, such as nickel, palladium or platinum. Only ten years ago non-metal systems based on boron and phosphorous compounds were discovered which allow comparable reactions.

“My doctoral researcher, Esther von Grotthuss, has achieved yet another major simplification of the non-metal strategy which requires only the boron component”, says Professor Matthias Wagner from the Institute of Inorganic and Analytical Chemistry of Goethe University Frankfurt. “What we additionally need is just an electron source. In the laboratory we chose lithium or potassium for this. When put into practice in the field, it should be possible to substitute this with electrical current.”

In order to explain the intricacies of hydrogen activation above and beyond experimental findings, quantum chemical calculations were carried out in cooperation with Professor Max Holthausen (Goethe University Frankfurt). Detailed knowledge of the reaction process is very important for the system’s further expansion. The objective lies not only in replacing transition metals in the long term but also in opening up the possibility for reactions which are not possible with conventional catalysts.

The chemists in Frankfurt consider that especially substitution reactions are highly promising which permit easy access to compounds of hydrogen with other elements. Expensive and potentially hazardous processes are still mostly used for such syntheses. For example, the simplified production of silicon-hydrogen compounds would be extremely attractive for the semiconductor industry.

Image for download: www.uni-frankfurt.de/63671511

Information: Prof. Matthias Wagner, Institute of Anorganic and Analytical Chemistry, Phone +49 (0)69 798-29156, Matthias.Wagner@chemie.uni-frankfurt.de