The future fuels of marine engines
Typ
Examensarbete på grundnivå
Program
Publicerad
2021
Författare
Bragge, Henrik
Chantongjaroen, Chatree
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This report is a combination of a literature review and a survey, which aims to answer the question whether alternative fuels can replace Heavy Fuel Oil (HFO)/Very Low Sulphur Fuel Oil (VLSFO) in the future, so that IMO’s climate goals can be met. The work has mainly been carried out at Chalmers, as study visits have not been possible to do, because of Covid.
As it seems today, almost all shipping is conducted with fossil fuels, but there are fossil-free alternatives that are used on a smaller scale. Shipping’s transport work (measured in ton*kilometre) is increasing annually, which means that the need for alternative fuels will increase even more in the future, if the transition to a fossil-free shipping is to take place, according to IMO’s future goals.
There are many ways to reduce carbon dioxide emissions. One of the most important is to switch to a fossil-free fuel, and in this text various promising alternatives have been reviewed, namely ammonia, methanol, biodiesel and liquified natural gas.
The focus of this work is ammonia, and the other fuels have been compared to this. Ammonia is a liquid carbon-free fuel, which does not lead to carbon dioxide emissions during combustion. It has no climate footprint at all, if the production and synthesis of the constituents take place with the use of renewable energy. With small changes to a diesel engine, it can run on ammonia instead of diesel oil. However, ammonia has a lower energy content than diesel, so larger tanks or more frequent bunkering is needed, when engines are operated on ammonia. This is because more fuel is needed for the same work. A reduction of speed can help reduce fuel consumption.
Another environmentally friendly fuel, if produced correctly, is methanol. It is a relatively cheap fuel, and it is possible to modify engines for methanol operation relatively cheap.
The other fuels mentioned in this work are also promising. However, Liquified Natural Gas (LNG) is a fossil fuel, albeit a very clean one. Large gas tankers already operate their engines on the boil-off from the cargo.
Biodiesel is good but expensive, and battery power is still for ships that run shorter routes, and is not discussed in this work.
A phasing out of fossil fuels clearly seems possible, as the production of alternative fuels is extensive and can be increased a lot. It is not possible to abandon fossil fuels directly, as the production of alternative fuels is not large enough yet, and one alternative fuel only cannot replace fossil fuels. On the other hand, a mix of alternative fuels will probably be able to replace fossil fuels in the future.
Carbon dioxide emissions from shipping are not a national problem, but an international one, so all shipping nations must cooperate, which is already being done within the IMO in a good way.
Beskrivning
Ämne/nyckelord
ammonia , biodiesel/HVO , methanol , LNG , alternative fuels , renewable fuels , future fuels , sustainability , decarbonization , internal combustion , methane , LNG/methanol bunkering checklist , HFO , IMO