The best solution for shipping would be to run on LNG, and have...

The best solution for shipping would be to run on LNG, and have an onboard Hazer plant to convert it to hydrogen before combustion. This would also then provide the option of using hydrogen fuel cells, which already have better efficiencies than thermal engines.

LNG tankers burn the boil off gas, in boilers to drive steam turbines. The have also tried to use LNG modified marine internal combustion engines but the methane slip (about 4% of the methane is not combusted and passes out in the exhaust gas), means that the green house emissions of these vessels is worse than ones burning Heavy Fuel Oil! The boiler / steam turbines, have much less slip because external combustion is much more complete, so it is not such an issue for them.

LNG is an established marine fuel, so they just need to bolt on the Hazer process and away they go. Not sure if a fluidized bed reactor would work on a ship though.