In the near future the usual summer ozone peaks exceeding the allowed threshold may be a thing of the past: the Paul Scherrer Institute (PSI) in Switzerland has developed a new type of catalytic conversion system, which filters nearly all nitrogen oxides out of diesel exhaust gases using a refined control technology. This eliminates the main cause of summer ozone build-up. The process requires a non-toxic urea solution, which future diesel engine commercial vehicles can take with them in a separate refillable tank.
Diesel engines are looked upon as relatively economic and environment-friendly, because they have a better fuel efficiency than gasoline engines. But burning diesel also has a grave disadvantage: it produces nitrogen oxides, which enhance the build-up of hazardous ozone during periods of high solar radiation. “In the end, diesel engines today are the main cause for high ozone values during summer”, says Oliver Kroecher, Exhaust Gas Aftertreatment Group Manager at PSI. Already by 2005, exhaust gas standards for diesel engines are to be tightened massively throughout Europe. And further steps reducing the threshold are planned.
To comply with the new threshold values engine manufacturers are now focussing on the so-called SCR (Selective Catalytic Reduction) technology. Here nitrogen oxides are transformed into nitrogen and water vapour using a catalytic converter and by adding a harmless urea solution. This compelling principle could establish itself in the foreseeable future in all commercial diesel-powered commercial vehicles. In future drivers should get used to refilling an additional urea tank.
Beat Gerber | alfa
Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy