90% of all globally traded goods today are transported by sea, this requires an enormous amount of fuel.
Marine transport produces about 2% of all greenhouse emissions, a number that the International Maritime Organisation (IMO) wants to halve.
The IMO aims to halve emission levels seen in 2008, by 2050, a move that will require a large scale move towards greener technology.
Research and development chief at Man Energy Solutions, Brian Soerensen says that several kinds of fuel are being considered, “One of the options we believe will be ammonia. Methanol could be another one, biofuel could be a third.”
Ammonia has the advantage of containing no carbon, so can burn in an engine without producing carbon dioxide.
Man Energy Solutions is planning to install an ammonia ready engine on a ship by 2024, with the first models being a hybrid fuel system able to use ammonia or traditional fuel.
Whilst liquid ammonia is less energy dense than petrol or diesel, it rates higher than hydrogen, a current zero emission fuel.
Hydrogen is cheaper to produce but more expensive to store, as it must be maintained at minus 253C.
“Ammonia sits very nicely in the middle,” says Dr Tristan Smith, an expert in low carbon shipping from University College London. “It’s not too expensive to store and not too expensive to produce.”
Burning ammonia however does produce nitrous oxides so its exhaust fumes will need to be scrubbed, it is also toxic so needs to be stored safely.
However the shipping company is well aware of the risk, already transporting ammonia for the fertiliser industry.
“It’s being transported seaborne today. We know how to handle ammonia on board a ship, not as a fuel, but as a cargo” says Soerensen.
Norwegian shipping company Eidesvik plans to install ammonia fuel cells aboard a vessel by 2023. These fuel cells will act like batteries, providing electrical energy to power a motor.
This is more fuel efficient over shorter journeys according to Vermund Hjelland, vice president of technology and development at Eidesvik.
You can have smaller tanks and get more kilowatt-hours out of the same amount of fuel. The picture is different compared to a super-tanker, it very much depends whether weight is an issue.”