Press release | 26.4.2016
Munich, 26 April 2016 – Using a noxious, caustic gas such as ammonia as a chemical to clean vehicle exhaust and as an eco-friendly alternative fuel may sound counterintuitive, but that's exactly what a group of Danish scientists set out to do. There was only one problem: Safety. Storing ammonia is problematic, to say the least. First of all, its boiling point is a chilly -33 °C. And due to its volatility, it needs to be stored in heavy, high-pressure tanks. Even in its pressurised, liquid form, ammonia is no less impractical, requiring special refrigeration technology, which is both costly and bulky. However, as this Danish research team discovered, storing ammonia in compact, solid form presented a perfect solution, one that unlocked the door to a number of useful applications.
For this achievement, the European Patent Office (EPO) has named Tue Johannessen, Ulrich Quaade, Claus Hviid Christensen and Jens Kehlet Nørskov as finalists for the European Inventor Award 2016 in the category "Small and medium-sized enterprises (SMEs)". The winners of the 11th edition of the annual innovation prize will be announced at a ceremony in Lisbon on 9 June.
"The invention of Johannessen, Quaade, Christensen and Nørskov is an important development for reducing pollution from diesel vehicles and it holds promise for other environmentally-friendly applications," said EPO President Benoît Battistelli announcing the European Inventor Award 2016 finalists. "At a time when much attention is being paid to reducing emissions, this team has NOxdemonstrated that humankind can overcome some of its biggest challenges through innovation."
By safely storing ammonia in solid form the scientists overcame the biggest obstacle for using ammonia as super-effective exhaust scrubber in diesel motors and opened up the potential for its use as an emissions-free fuel. One advantage of storing ammonia in solid form is that there is no need to manage the high pressure at room temperature ; another advantage is its portability. Roughly 50 grams of solid ammonia is equivalent to a staggering 60 litres of pure ammonia gas.
For ammonia to become solid, it must form a compound with certain metal salts, such as strontium chloride. These act like a sponge, absorbing large quantities of ammonia without sacrificing volume. In fact, a 100-gram cube of this new solid, sold under the brand name AdAmmine™, can fit into the palm of one's hand yet contain up to 50 grams of solid ammonia. To market their technology, Johannessen, Quaade, Christensen, Nørskov and a fifth co-researcher named Rasmus Zink Sørensen founded a company called Amminex in 2005. With Johannessen now as CTO, it sells cartridges of AdAmmine and complete dosing systems for controlled use of ammonia. AdAmmine can be used in a number of different ways, such as energy carrier for electric fuel cells. Amminex, however, currently focuses on a different use altogether: When ammonia is released into the exhaust system of diesel engines, it can reduce the amount of harmful emitted NOx (nitrogen oxides, a toxic pollutant and a key component of smog) by up to 99%. Their patented technology can thus reduce air pollutants and improve quality of life.
"The technology not only leads to a very low nitrogen oxide levels in vehicle exhaust; the engine can also run at its optimal operating temperature, which results in lower CO2 emissions," says Johannessen.
What happens when ammonia is mixed with diesel exhaust gases? It reacts with NOx which is then split into water vapour and nitrogen - harmless gases that already abound in the earth's atmosphere. Systems for neutralising dangerous chemicals in diesel exhaust - a form of scrubbers - have existed for some time but for the most part, they're urea-based and only begin "scrubbing" once engine temperatures reach upwards of 200°C. That's fine for main roads, but it poses a problem for inner-city commutes, because engines simply don't reach the required temperatures in short-distance driving and low speed. AdAmmine, on the other hand, can release ammonia into exhaust lines well below 200°C. One of Amminex's product offerings, the so-called Ammonia Storage and Delivery System, or ASDS, uses AdAmmine to mix ammonia with exhaust at temperatures under all relevant driving conditions. That means it puts out cleaner exhaust where people actually live and breathe - a significant feat if you consider the fact that air pollution is responsible for roughly 7 million premature deaths around the world every year, according to estimates from the World Health Organisation.
When Johannessen, Quaade and their team founded Amminex, they spun it off from the Technical University of Denmark (DTU). It was there that Johannessen received his PhD in chemical engineering and worked as an associate professor in the Department of Chemical and Biochemical Engineering. Quaade, who is now Amminex's head of R&D, was also an associate professor at the Technical University, but in the physics department, after receiving his PhD in physics from the University of Southern Denmark. Christensen was awarded a master's degree in chemistry at the University of Copenhagen, while Nørskov received his master's degree in physics and chemistry, followed by a PhD in theoretical physics, both from the University of Aarhus, Denmark. They were both professors at DTU at the time - at the departments of chemistry and physics respectively.
Once Amminex was founded in 2005, it did not take long for the company to transform from a small research firm into a respected, credible player in the automotive industry. Its fast growth and development of the product was augmented by four successful investment rounds and now having entered the market Amminex's annual turnover is reported as EUR 4.3 million. In the course of its (brief) history, the company's founders have overcome a number of real-world technical problems, not least of which has been establishing a process and an infrastructure so customers can refill their AdAmmineä cartridges. In 2010, Amminex began construction on its first large-scale processing plant. The company recently landed a contract to upgrade 300 city buses in Copenhagen and has also received grant money from the European Union, Horizon 2020, to explore technology that would combine ultra-low NOx emissions with high fuel efficiency.
The Danish Amminex team is helping to make diesel exhaust cleaner and paving the way for low-emission transportation. They join a list of many other European Inventor Award finalists and winners, recognised for their contributions to more environmentally-friendly travel. Read more about energy-efficient innovations.
Director External Communications
European Patent Office
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