Ammonia could be the fuel of the future for shipping – Telegraph.co.uk

Typically, ammonia is made in a process known as steam reforming. Hydrogen is generated from a reaction involving methane, water and air, and then combined with nitrogen in a process known as the Haber method. However,carbon dioxide is produced as a byproduct.

Dr John Constable, director of the Renewable Energy Foundation, sees one fix for this that banks on carbon capture and storage, a relatively unproven technology that reels carbon dioxide from the air and stores it deep underground. If you can capture the carbon from steam methane reforming, it may be clean at the point of consumption, he says.

Another method picking up traction from Wrtsil involves the use of electricity generated by wind farms to split water into its constituent components of hydrogen and oxygen through a process known as electrolysis.

That hydrogen can then be combined with nitrogen pulled from the atmosphere to create ammonia in a way that has cut carbon emissions altogether. For years, the method has proved too costly given the high price of renewable energy, but it is getting cheaper. Hystad claims 400gW of wind turbines are due to be installed in the North Sea between now and 2050, more than 20 times the current output.

With clean options of generating ammonia emerging, the next challenge involves turning it into a form that can be used as fuel. Wrtsil is exploring the possibility of pumping ammonia 70m below sea level where high pressure can turn it into a liquid, while another option involves cooling the gas to -40 degrees C to liquefy it.

Once in a liquid form, ammonia can be used in a retrofitted internal combustion engine, such as the ones Wrtsil are looking at in existing ships, or can generate electricity in a reaction driven by a device known as a fuel cell.

The ability to create green ammonia is opening up potential applications far beyond the high seas too. A study led by Davennes team in Harwell has been investigating the potential for ammonia to replace kerosene as the go-to fuel in the aviation industry.

At a cruising altitude, ammonia could sit in the wings of a plane as a liquid, given the sub-zero temperatures 30,000ft in the air, and the engine would need few changes to accommodate for ammonia according to their research.

But there are some real hurdles to overcome to get ammonia working as a fuel.

In planes, ammonia could struggle as its energy density is a lot lower than kerosene, meaning much more fuel will be needed onboard. On the ground, wings would have to be refrigerated as ammonia is a gas in that atmosphere, Davenne says.

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Ammonia could be the fuel of the future for shipping - Telegraph.co.uk