In the future, closed carbon loops play an important role to drastically reduce carbon dioxide emissions and ensure safe and cost-effective access to carbon sources as the basis for products of the chemical industry. In order to increase the efficiency and thus profitability of the synthesis processes required for this, Fraunhofer IKTS has developed a new membrane reactor in cooperation with the Thuringian company MUW-SCREENTEC GmbH.
A closed carbon loop is based on the constant conversion of carbon dioxide by energy – ideally from renewable sources. For example, this power can be used to exploit hydrogen, which, using carbon dioxide, can be converted into storable substances such as methanol.
The liquid and thus transportable storage material methanol, produced according to the “power-to-liquid“ principle, has a high energy density and allows unlimited storage without losses. This valuable energy source is also an important basic chemical for further syntheses, e.g. for plastics.
At present, the necessary removal of water from hydrogen and carbon dioxide is still a separate step in the synthesis of methanol. The thermal processes used are energy-intensive and reduce efficiency. With a so-called membrane reactor, it has now been possible for the first time to couple the chemical reaction with the separation of substances in one apparatus. The concept was developed and demonstrated in hardware by the Fraunhofer Institute for Ceramic Technologies and Systems IKTS and MUW-SCREENTEC GmbH with the support of Thüringer Aufbaubank.
The membrane-based separation of the water from the reaction space shifts the position of the chemical equilibrium during synthesis in favor of methanol. Based on these results, simulations suggest a significant increase in methanol yield to 60 % in membrane reactors instead of 20 % in conventional reactors when upscaling to industrial plants. The experimental proof of the exact increase of the yield is currently provided by the project partners.
The membranes required for the reactors were also developed at Fraunhofer IKTS. In addition to their water-separating properties, they must also be mechanically, chemically and thermally stable under the demanding process conditions. So far, carbon membranes have proven to be particularly effective for methanol synthesis.
The reverse reaction of methanol synthesis – methanol reforming – can also be implemented efficiently in the new membrane reactor. The methanol serves as easy-to-handle liquid hydrogen storage system. The resulting carbon dioxide is separated in the membrane reactor and is thus available again as a starting material for a closed carbon loop. Such closed concepts can be used, for example, to supply ships with hydrogen fuel, which is exploited from easily transportable methanol and water.
With the newly developed membrane reactors, synthetic methane can be produced under modified process conditions and with other catalysts from carbon dioxide and hydrogen, which can be stored unlimitedly in the natural gas network. In addition, alternative fuels such as dimethyl ether or the important basic chemical formaldehyde can be synthesized, thus implementing the “power-to-chemicals strategy“.
In order to achieve further efficiency increase of the synthesis processes, following research work will focus on a targeted improvement of the catalyst properties. Fraunhofer IKTS is therefore developing catalysts that can be applied directly to the membrane rather than in bulk as in the past. “Fraunhofer IKTS has both the entire process chain for the production of stable and selective membranes and extensive expertise in catalyst and process development – a unique competitive advantage worldwide," says Dr. Norman Reger-Wagner, group manager at the Thuringian site.
The continuous improvement of the membranes and the process – for example by selective, membrane-based dosing of hydrogen into the reaction space – is expected to lead to further significant efficiency increases.
Dipl.-Chem. Katrin Schwarz | Fraunhofer-Institut für Keramische Technologien und Systeme IKTS
Lethal combination: Drug cocktail turns off the juice to cancer cells
12.12.2018 | Universität Basel
Smelling the forest – not the trees
12.12.2018 | Universität Konstanz
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
12.12.2018 | Health and Medicine
12.12.2018 | Physics and Astronomy
12.12.2018 | Health and Medicine