A research chemist from Eindhoven University of Technology (TU/e) has developed a technique that could revolutionize agriculture. The new method coverts nitrogen from the atmosphere into NOx, the raw material for fertilizer, at a rate that is up to five times more energy efficient than current processes. With relatively low power usage, and only air as a raw material feedstock, the discovery could remove the need for large scale ammonia and nitrate manufacturing. In its place, more localized fertilizer production could be possible, even in remote areas of third world countries.
Developed as part of a research program in cooperation with Evonik Industries and the EU’s MAPSYN consortium, the novel process is already drawing interest from competing fertilizer producers. Meanwhile, other researchers are studying the possibility of using the process as a growth stimulant in greenhouses, or for storing sustainable energy in liquid fuels.
Given that current methods for the production of ammonia (NH3) or nitrogen oxide (NOx) for fertilizer manufacturing are responsible for about 2% of all global CO2 emissions, then any reduction in energy requirement is certain to be welcome. Researchers have already analyzed ways to reduce power consumption in the current process, but have generally concluded that the theoretical minimum has already been reached.
This led PhD candidate Bhaskar S. Patil to seek completely new ways to produce ammonia and nitrogen oxides. The result of which was two new types of reactor, the Gliding Arc (GA) reactor and the Dielectric Barrier Discharge (DBD) reactor.
Reporting on the breakthrough, the TU/e website explains how, “In his [Patil’s] 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).”
While the process may sound a little high-tech for a small farmer in rural India, the results point to a potential game-changer for the fertilizer industry, and certainly an idea that is worth developing further.
Patil has already devised a highly efficient process, and could achieve much more, as the online journal, ScienceDaily, reports, “Patil optimized this reactor and at a volume of 6 liters per minute 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.”
While at present, the idea has a lot of theory and not so much practical application, the chance to feed billions of hungry people, and help limit climate change at the same time cannot be ignored. Needing to lower both costs and environmental impact, fertilizer suppliers have been hoping for an improved production method for decades.
In answer to those needs, Patil, it seems, has developed a process from thin air that uses, as a fertilizer feedstock; thin air. With a five-fold increase in efficiency, and almost zero raw materials needed, can ammonia and nitrate manufacturers afford to ignore this discovery?