A review of low and zero carbon fuel technologies: Achieving ship carbon reduction targets

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.…”

“…The recent resurgence of interest in NH 3 as a fuel led to a rapid increase of scientific publications, as demonstrated by the large number of review articles published on this topic in the last four years only. ,,− Reluctance to burn remains a recurrent issue with NH 3 , but the high NO x emissions typically associated with NH 3 combustion are now also at the heart of the problem. Although fewer in number than studies on fundamental and laboratory-scale NH 3 combustion, studies dealing with the use of NH 3 to fuel practical combustion devices are steadily increasing too.…”

“…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.…”

The use of alternative fuels for maritime decarbonization: Special marine environmental risks and solutions from an international law perspective

“…Biofuels come from biomass and can be regenerated from crops or biological waste, such as growing maize to produce ethanol and using animal waste products (Varuvel et al, 2012). Large-scale cultivation of the same plants may cause pests, while the use of fertilizers and pesticides will pollute water sources and potentially reduce biodiversity (Vollebergh, 1997;Wang et al, 2022a). The production of energy crops produces GHGs, of which N 2 O emissions are usually high.…”