This week, an important new voice joined the chorus of support for renewable ammonia and its potential use as an energy vector - the International Energy Agency (IEA).
In his article, Producing industrial hydrogen from renewable energy, Cédric Philibert, Senior Energy Analyst at the IEA, identifies a major problem with the hydrogen economy: hydrogen is currently made from fossil fuels. But his argument for producing hydrogen from renewable energy leads almost inevitably to ammonia: "In some not-too-distant future, ammonia could be used on its own as a carbon-free fuel or as an energy carrier to store and transport energy conveniently."
Next month the print edition of Fuel Processing Technology will feature a paper entitled “Auto-ignition of a carbon-free aqueous ammonia/ammonium nitrate monofuel: a thermal and barometric analysis.” This title is provocative. First, what is this idea of a fuel composed of a mixture of ammonia and ammonium nitrate (AN)? If ammonia is a good fuel, is it made better with the addition of ammonium nitrate? Second, why is it aqueous? Is the presence of water a feature or a bug? Third, what is a monofuel and why is this term used when the fuel is a mixture of two molecular species? And finally, why is the paper ultimately about auto-ignition?
Developers around the world are looking at using ammonia as a form of energy storage, essentially turning an ammonia storage tank into a very large chemical battery.
In the UK, Siemens is building an "all electric ammonia synthesis and energy storage system." In the Netherlands, Nuon is studying the feasibility of using Power-to-Ammonia "to convert high amounts of excess renewable power into ammonia, store it and burn it when renewable power supply is insufficient."
While results from Siemens could be available in 2018, it might be 2021 before we see results from Nuon, whose "demonstration facility is planned to be completed in five years." But, while we wait for these real-world industrial data, the academic literature has just been updated with a significant new study on the design and performance of a grid-scale ammonia energy storage system.
Over the last few weeks, I've written extensively about sustainable ammonia synthesis projects funded by the US Department of Energy (DOE). While these projects are important, the US has no monopoly on technology development. Indeed, given the current uncertainty regarding energy policy under the Trump administration, the US may be at risk of stepping away from its assumed role as an industry leader in this area.
This article introduces seven international projects, representing research coming out of eight countries spread across four continents. These projects span the breadth of next-generation ammonia synthesis research, from nanotechnology and electrocatalysis to plasmas and ionic liquids.
A common concern with ammonia fuel is that NOx emissions will be too high to control. However, in new research from Turkey, USA, and Japan, presented at this year's NH3 Fuel Conference in September 2016, two things became clear.
First, NOx emissions can be reduced to less than 10ppm by employing good engineering design and exploiting the chemical properties of ammonia, which plays a dual role as both the fuel and the emissions-cleanup agent.
Second, the deployment of ammonia-fueled turbines for power generation is not only feasible, but actively being developed, with demonstration units running today and improved demonstration projects currently in development.