A third of shipping will run on ammonia, MAN predicts
Engine maker hails promising test results as it readies engines to go on sale at end of 2026
MAN Energy Solutions said more than 300 single-cylinder and full-scale engine tests have showed a 90% CO2 equivalent reduction
MAN Energy Solutions has hailed promising test results on the rollout of its ammonia engines, which are set to go on sale at the end of 2026.
The German engine maker said more than 300 single-cylinder and full-scale engine tests in the past 18 months had showed NOx emissions down 40%-50% compared with diesel, and CO2 equivalent greenhouse gas emissions down by 90%.
Compression, combustion and expansion characteristics were similar to those of existing dual-fuel engine technology and there was no variation in performance between cylinders, thanks to innovative engine control software.
MAN head of two-stroke sales Christian Ludwig said he expected ammonia would eventually power one third of global shipping and methanol about a quarter.
But Ludwig said MAN would not rush the engines to market, despite the promising test results, so not to jeopardise safety.
“We foresee a very strong future for ammonia as a fuel,” he said.
“And we want to make sure that we introduce it into the market — not only from an engine technology perspective, but also from an auxiliary system, safety system and the whole ecosystem — the best possible way.”
Nikolaos Kourtidis, senior adviser in new technologies and dual-fuel engines, said the engine would have a selective catalytic reduction system running constantly, in such a way that the ammonia slip neutralised NOx emissions through a chemical reaction.
“The aim is to have the ammonia slip slightly below the NOx levels, cancelling each other,” Kourtidis said.
MAN tried many different injection technologies to find the balance between emissions of ammonia slip, NOx and nitrous oxide. It said the final numbers would be decided by future regulation.
N2O, or “laughing gas”, is a greenhouse gas 300 times stronger than CO2, so is important to minimise.
“We can announce to the market that the nitrous oxide levels that we are observing a very low, and typically well below the five [parts per million] margin,” Kourtidis said.
“If you consider the total equivalent emission from an ammonia engine, we can say that, including the pilot oil, we see more than 90% CO2 reduction able to be achieved.”
The engine maker is targeting 5% pilot fuel consumption at 100% engine load.
Ammonia is highly toxic, meaning extra safety features are needed.
These include double-walled pipes with an absorber, so any leaks from the inner to the outer pipes can be monitored and contained.
An ammonia catch system would ensure all ammonia vapours are removed and diluted in a water bath, before releasing at most 5 ppm into the environment.
Some ammonia will have to be disposed of as chemical waste and MAN is open to proposals for dealing with this matter.
MAN process engineer Ian Kumaraswamy said the team spent about 5,000 hours on internal risk assessments.
Kumaraswamy added that MAN engaged in pilot projects to use its ammonia engine on ammonia carriers, feeder vessels, bulkers, car carriers and oil tankers, and worked closely with owners and class societies on safety.
MAN’s four-cylinder, 50-bore test engine in Copenhagen could pump out about 6,300 kilowatts of power at 123 rpm. It had run for hundreds of hours, often at 100% load, the company said.
The first shipbuilding contract for the new ME-LGIA engine was in place with Eastern Pacific Shipping for two 93,000 cu m very large ammonia carriers, from HD Hyundai Heavy Industries shipyard in Ulsan, South Korea.
Expected delivery of the engine to the shipyard will be in the first quarter of 2026.
