Stock up on solar warmth for the winter

 

In many processes heat occurs which is then released into the environment unused. It can actually be saved and made useful as energy. However: the processes are often too expensive for wide-ranging uses in industry or in private households and for that reason are not often viewed to be genuine alternatives to the use of fossil fuels. So that this situation changes, Prof. Dr. rer. nat. Franziska Scheffler of the Institute for Chemistry at Magdeburg University is working on a project. Saxony-Anhalt is viewed as being a pioneer in the search for alternative sources of energy, of which the research project by Franziska Scheffler in the area of chemicals is an example.  A model stands on the professor's desk. Yellow and purple sticks form a frame. For the layman it is an amusing sight. For Franziska Scheffler it is the basis of her research project. The plastic frame represents a zeolith. It's extremely simple – having been designed for the layman and intended for illustration.  In reality, zeoliths, which are also known as catalysts, are highly complex. They can appear in over 100 different structures. What makes them so exciting for Franziska Scheffler, however, is that these materials can store heat. The problem is they do not do this in a sufficiently targeted way. "We want to develop new materials which can store heat even better," says Scheffler, explaining the goal of the research project in basic terms. Her drive to research in this area quickly brought her to a conclusion: that the existing technology would be usable for a long time. Yet: "It simply isn't cheap enough to find wide-ranging use." Storing heat which already exists is too expensive as it costs almost 30 percent more than using fossil fuels like coal or crude oil. "The focus is frequently only on the obtaining and storing of electrical energy. The fact that half of our current requirement for energy relates to the use of heat is often ignored. And the storage of heat on an adsorption basis is an important theme," she describes. Finding the ideal porous – i.e. permeable – materials for the storage of heat is no small task, explains Franziska Scheffler. The uses of stored heat are as varied as the existence and use of heat itself. In many branches of industry, excess heat occurs which is not used – something which could change with the correct technology. This technology would have to contain the perfect storage material – as found in the Institute of Chemistry at Magdeburg University.  As an example, Prof. Franziska Scheffler discusses glass production. When glass is melted and then cooled down again, a significant amount of heat occurs. "If this could be used and the next glass charge were then pre-heated, it would save a lot of fuel material," she explains. In private households, the use of heat storage systems with optimised materials would also make a more economical consumption of crude oil and gas possible. Solar thermal systems are already fitted on many rooftops, an efficient method for using solar energy. These systems are frequently only used to heat water, however. In the summer, these systems can also generate far more energy than is actually used. The energy is then lost. "If we could store this heat so that we could use it again in the winter, that would be really great," explains Franziska Scheffler. "Like bottling the heat, as it were." Technically, such a system would work via a container with copper pipes and a filling made from zeolith. The way in which the container works is decisive. Efficient work – from every point of view – is the priority of the researchers from Magdeburg. To this end, Professor Scheffler is researching in many different directions. She is supported by her colleagues as well as by students on a new masters programme which was established during the winter semester at the Otto-von-Guericke-University. Entitled "Sustainable Energy Systems", 23 students are enrolled on this course, studying, among other fields, the storage of heat. "We have worked hard on getting this course of study up and running," explains Franziska Schenk. "The theme of sustainable energy is too important and too exciting to be given too little attention."  She is currently focusing on the storage of heat with the help of porous materials as well as the possibility of converting heat that is not such a high temperature into heat of a higher temperature using a heat pump, thereby concentrating energy. The Magedeburgers are also researching this. With all of these possibilities, the chemistry has to be right. The chemists at the der Otto-von-Guericke-University primarily have one goal that focuses on the attributes of the zeoliths – and which leads back to this model on Scheffler's desk. "We want to develop a similar, related product. But it should have even better attributes." How are Professor Franziska Scheffler and her team going to do this? They are proceeding on a step-by-step basis. "We can change the production of the material and therefore its attributes," she explains. Put in simple terms: the project participants change the process steps and then research on how the structure has changed. The new structures are researched with different methods of analysis and their attributes are determined, and at successful end, the professor and her assistants have turned the zeolith into something which has economic prospects in terms of this new area of application.  In five years' time, the world of the storage of heat could look different, predicts Franziska Scheffler. She has long been focusing on the materials that make up this forecast. She previously worked on zeoliths several years ago during her doctorate as well as during research projects for other uses in other areas. As she discusses her work, a ray of sunlight falls onto her desk and hits the hollow section and the pores in the plastic zeolith model, relaying between the purple and yellow coloured sticks. It's only a coincidence, nobody can actually influence the sun. "But using excess heat is something we should not let go," explains Prof. Franzsika Scheffler. Contact:Prof. Dr. rer. nat. Franziska SchefflerOtto-von-Guericke-Universität MagdeburgInstitute of ChemistryGebäude 16Universitätsplatz 239106 Magdeburgph: +49 (0)391 / 6718824E-Mail: franziska.scheffler@ovgu.deWeb: www.uni-magdeburg.deAuthor/Photographer: Manuela BockPhoto: Professor Franziska Scheffler with a zeolith model