Waste heat from industry can often not be utilised because of its low temperature. With this material, it can be used in environmentally friendly cooling systems for example in the field of building technology. The research team from Kiel will present its material and its applications at the Hannover Messe 2018.
Cooling devices are considered to be power guzzlers, in which polluting refrigerants are still used, even after the ban on chlorofluorocarbons (CFCs). An environmentally friendly alternative are systems which use water instead.
In the large pores of the material’s framework structure , it can absorb and release water molecules highly efficiently.
Image: Dirk Lenzen
A research team at the Institute of Inorganic Chemistry at Kiel University, together with the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, has developed a highly-porous material, with which these cooling systems can be operated using less electrical energy than before. Previously-unused waste heat, e.g. from district heating systems, data centres, or heat from solar thermal collectors could be used for that. The results have been published recently in the journal Advanced Materials.
Data centres in particular are real energy factories: as a side-effect of their operations, high-performance computers produce a lot of heat, and must therefore be cooled continuously. As such, they cause high energy and power costs, while giving off unused waste heat to the environment at the same time – its temperature is too low for other uses.
Theoretically, however, this could be used for running energy-efficient cooling systems, which use water as a refrigerant (so called adsorption-driven chillers). To do so, the material used there must be able to absorb a lot of water and regenerate at the lowest possible temperatures.
Environmentally-friendly and resource-saving cooling
The porous material, developed by Professor Norbert Stock from the Institute of Inorganic Chemistry and his working group, fulfils these requirements. This way parts of the cooling process of adsorption-driven chillers can be operated using only the energy from existing waste heat or solar thermal systems. "This could also make an important contribution to the use of renewable energies," said Stock. For environmentally friendly systems like this the material has two key advantages: "The systems consume less power, and we can produce the material in an eco-friendly manner," explained the inorganic chemist.
In these so-called adsorption-driven chillers, the cooling effect occurs when ambient heat is extracted by the evaporation of water. The molecules of water vapour are deposited in the cavities of a porous material, called sorbents, i.e. adsorbed by it. In the following regenerative phase the material is dried by applying thermal energy. The stored water molecules are released, liquefy and can be evaporated again in the next cycle. The material can also be used again.
Highly-porous metal organic frameworks provide ideal interactions
Sorbents used in cooling systems are usually crystalline zeolites or silica gels, which can easily absorb water due to their structure. The research team’s material exhibits particularly good sorption properties: it can absorb a lot of water very quickly, and also release it quickly again - even at a low increase in temperature. The material is thus quickly ready for use again. "This is made possible by the optimal size of the pores in the material, and its perfect interaction with the water molecules," explained Stock. The highly-porous crystal structure of "CAU-10-H" - which is the official name of the material, named after development location, version number and the abbreviation of hydrogen - is an example of a metal organic framework (MOF). They have been tested in a wide range of areas of application in recent years.
From fundamental research to practical application
The Kiel working group has already been pursuing the discovery of new MOFs for a long time - but previously only as pure fundamental research. For transfer to an industrial application, they worked with colleagues from the Fraunhofer ISE to coat commercially available heat exchangers with their material. "The survey of the heat exchanger under application-related conditions shows the high potential of the material" said Dr Stefan Henninger from the ISE. In the laboratory, the material can already be produced in kilogramme quantities under mild reaction conditions, i.e. at a temperature of 100°C with water as a solvent ("green synthesis"). "In order to produce the material for an industrial use on a larger scale, our next step is to contact other companies," said Stock. They have already applied for a patent for their production method.
From 23 until 27 April 2018, the research team will be presenting the material and its applications at the Kiel University booth at the Hannover Messe (Hall 2, Research & Technology, Booth C07). In addition, Professor Stock will present a lecture on-site on Wednesday 25 April 2018 at 2.30pm and 5pm, titled "Nanoporous materials for modern and environmentally-friendly cooling and air-conditioning". The state university is represented at the world's largest industrial trade show for the second time, and presents innovative contributions from the research and industrial location of Schleswig-Holstein: http://www.uni-kiel.de/hannovermesse
Scalable Green Synthesis and Full-Scale Test of the Metal–Organic Framework CAU-10-H for Use in Adsorption-Driven Chillers. Dirk Lenzen, Phillip Bendix, Helge Reinsch, Dominik Fröhlich, Harry Kummer, Marc Möllers, Philipp P. C. Hügenell, Roger Gläser, Stefan Henninger and Norbert Stock. Advanced Materials. https://doi.org/10.1002/adma.201705869
Photos are available to download:
Caption: For their tests, they coated a conventional heat exchanger (as used in commercial refrigeration equipment) with the new material, in cooperation with colleagues from the Fraunhofer Institute for Solar Energy Systems.
Photo: Dirk Lenzen
Caption: With their newly-developed material called "CAU-10-H", shown here in powder form, the Kiel research team aims to make cooling systems more efficient.
Photo: CAU/Stock working group
Caption: Different atoms (green = aluminium, red = oxygen, grey = carbon) together form the framework structure of CAU-10-H, which was developed at Kiel University. In the large pores, it can absorb and release water molecules (blue) highly efficiently.
Image: Dirk Lenzen
Prof. Dr Norbert Stock
The Institute of Inorganic Chemistry
Dr Stefan Henninger
Fraunhofer Institute for Solar Energy Systems (ISE)
Materials and Components for Heat Transformation
Christian-Albrechts-Universität zu Kiel
Press, Communication and Marketing, Dr Boris Pawlowski, Text/editing: Julia Siekmann
Postal address: D-24098 Kiel, Germany,
Telephone: +49 (0)431 880-2104, Fax: +49 (0)431 880-1355
E-mail: firstname.lastname@example.org, Internet: www.uni-kiel.de, Twitter: www.twitter.com/kieluni Facebook: www.facebook.com/kieluni, Instagram: instagram.com/kieluni
Dr. Boris Pawlowski | Christian-Albrechts-Universität zu Kiel
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences