Full-scale engine tests running on ammonia and hydrogen as fuels have recently been carried out in Wärtsilä’s engine laboratory in Vaasa, Finland.
The tests are being performed to assess the optimum engine parameters for running on these fuels and the results are reported to be “very encouraging.” One test engine performed very well when running on a fuel with 70% ammonia content at a typical marine load range. Tests were also completed successfully on another engine in pure hydrogen operation.
https://www.marinelog.com/engines-fuel/wartsila-reports-encouraging-results-with-zero-carbon-fuels/