Challenges and opportunities of marine propulsion with alternative fuels

Mini Review of Ammonia for Power and Propulsion: Advances and Perspectives

“…Spark-ignition (SI) and compression-ignition (CI) engines are both considered for NH 3 engines. Consistent with findings from the 1960s − and from more contemporary studies listed in review articles, ,,,− very recent studies on SI engines report that pure NH 3 operation is possible as long as the spark timing is advanced, ,,, ignition is achieved via turbulent jet injection, the intake is boosted, or the compression ratio is increased . However, a performance with NH 3 on par with that possible with gasoline can only be achieved for specific conditions, typically at full-load only, and the NH 3 SI engine does not yet boast a wide operability range. , Also consistent with earlier studies, NH 3 -H 2 SI engines can also perform well. , Multiple studies confirm that a SCR post-treatment system remains necessary to take care of NO x emissions. ,,, Resorting to an SCR post-treatment system to abate NO x emissions is already ubiquitous in piston engines fueled by gasoline or diesel.…”

“…Many of these studies are already featured in the aforementioned review articles. For example, there exists detailed accounts of gas turbines applications. ,,− , Progress in piston engines is narrated in multiple review articles too. ,,,− There are also review articles listing studies on boilers and furnaces employing NH 3 . ,− , The reader is also referred to the book by Valera-Medina and Banares-Alcantara published in 2020 for techno-economic analyses of NH 3 as an energy vector, as the present review focuses on studies detailing actual measurements or advanced numerical simulations in practical devices. Table lists some of the studies featuring practical devices that are too recent to be featured in the aforementioned review articles.…”

“…Regarding piston engines, there are potential applications of NH 3 combustion in light-duty, heavy-duty, and marine transportation. It can be seen from multiple review articles ,,,− and Table that most studies that are publicly available deal with light-duty engines. Arguably, the main reason for this is that light-duty engines are more readily available in research laboratories, and it is probably unwise to take this as an indication that light-duty NH 3 engines are more promising or forthcoming than their heavy-duty or marine counterparts.…”

Post COVID-19 ENERGY sustainability and carbon emissions neutrality

“…Recent advancement in ammonia-fuelled engine shows that ammonia burning is feasible by mixing with hydrogen for power generation, but the potentially high NO emissions need to be addressed [ 115 ]. Due to the convenience in storage, ammonia is suitably be used as marine fuel for low and medium-speed engine operations [ 116 ]. However, the low energy intensity for ammonia and hydrogen makes the fuels unsuitable for aviation turbine engine operation due to the aircraft's limited fuel tank space and weight distribution consideration.…”

A Numerical Study of Decarbonizing Marine Gas Turbine Emissions Through Ammonia/Hydrogen Fuel Blends

“…About 90% of world's goods are transported by ships. Fossil fuel consumption by marine industry accounts for 330 million metric tons annually most of which are low grade fuels that contributes to a significant portion of emissions of Sulphur Oxide (So x ), Nitrous Oxide (NO x ), Particulate Matter (PM), Carbon Monoxide (CO) as well as Carbon Dioxide (CO 2 ), [1]. It is the latest that is being considered the main reason for GHG concern at the time being.…”