May
17
A New Highly Efficient Air To Fertilizer Process
May 17, 2017 | 2 Comments
Eindhoven University of Technology in the Netherlands scientists have invented a revolutionary reactor that coverts nitrogen from the atmosphere into NOx, the raw material for fertilizer. In theory the method is up to five times as efficient as existing processes, that would enable farms to have a small-scale installation without the need for a big investment.
The inventor, Bhaskar S. Patil, new reactor design may develop to be up to five times as efficient as existing processes. The production of one of the key raw materials for fertilizer, ammonia (NH3) or nitrogen oxide (NOx), is a very energy-intensive process and the secondary product, CO2, is about 2% of all global fuel derived production.
However, it is hardly any longer possible to cut the energy consumption via current production processes since the theoretically minimal feasible energy consumption has already been more or less reached.
Patil sought alternative methods to produce ammonia and nitrogen oxides for his PhD research, building two types of reactor, the Gliding Arc (GA) reactor and the Dielectric Barrier Discharge (DBD) reactor.
In his experiments the GA reactor in particular appeared to be the most suited to producing nitrogen oxides. In this reactor, under atmospheric pressure, a plasma-front (a kind of mini lightning bolt) glides between two diverging metal surfaces, starting with a small opening (2 mm) to a width of 5 centimeters. This expansion causes the plasma to cool to room temperature. During the trajectory of the ‘lightning’, the nitrogen (N2) and oxygen (O2) molecules react in the immediate vicinity of the lightning front to nitrogen oxides (NO and NO2).
Patil optimized the GA reactor and at a volume of 6 liters per minute and managed to achieve an energy consumption level of 2.8 MJ/mole, quite an improvement on the commercially developed methods that use approximately 0.5 MJ/mole. With the theoretical minimum of Patil’s reactor, however, being that much lower (0.1 MJ/mole), in the long term, this plasma technique could be an energy-efficient alternative to the current energy devouring ammonia and nitrate production. An added benefit is that Patil’s method requires no extra raw materials such as natural gas and production can be generated on a small scale using renewable energy, making his technique ideally suited for application in remote areas that have no access to power grids, such as parts of Africa.
The German Evonik Industries, who was involved in this research project, is now working on the further development of the reactor. In addition, another PhD student at TU/e has begun establishing the aspects of this technology into a concrete business model. Apart from use at remote farms, this technique can also be used to stimulate the growth of plants in greenhouses and to store sustainable energy in liquid fuels.
This press release is full of promise, sets up numerous questions, offers very little detail and a bit of confusion. The idea that food fiber and fuel production could progress without a huge natural gas component is a great motivator. Add to that an investment cost that might work even for African farmers makes for an intensely interesting story to watch unfold.
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Truly a remarkable achievement. Using plasma to mimic Nature’s use of lightning was a brilliant idea.
But – the power consumption statement has me confused. Saying his unit’s 2.8 MJ/mole was better than the commercial 0.5 MJ/mole average makes me wonder if the numbers were not switched in the Press release.
Has me confused to. But that’s from the press release so if it changes I’ll change too.