What do we mean by new fuels?
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- Category: Energía y Combustibles
- Published on Friday, 10 May 2024 18:08
- Written by Administrator2
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24 April 2024
Artist's impression of bunkering for a vessel powered by liquefied hydrogen fuel. Image: Getty Images
There are numerous options in the mix to replace heavy fuel oil and diesel, and opinion is divided on which of these new fuels – also known as 'future fuels' or 'alternative fuels' – will end up on top. Lucy Chapman explores the pros and cons of some of the main contenders
Hydrogen
Pros |
Cons |
| Does not release greenhouse gases when burnt as fuel - only water vapour and oxygen | Highly explosive if not stored and handled correctly |
| Already a global hydrogen market | Combustion can lead to the thermal formation of nitrogen oxides (NOx) |
| Can be stored in large amounts for long periods of time | Low energy density increases storage needs |
| Only releases water vapour and oxygen as by-products. Easy to fit existing ships with hydrogen fuel cells | Producing hydrogen from renewable sources is expensive |
Ammonia
Pros |
Cons |
| Does not release greenhouse gases when burnt as fuel | Most ammonia is produced from natural gas - a fossil fuel |
| Green ammonia causes no greenhouse gases when burnt as fuel | Highly toxic - even small volumes in the air can be fatal |
| Easy to store and transport | Combustion can produce NOx emissions |
| Low flammability | Highly corrosive |
Methanol biofuel
Pros |
Cons |
| Low NOx, sulphur oxide (SOx) and particulate emissions | Releases some greenhouse gas emissions when burnt as fuel |
| High energy density requiring less storage space | Most methanol is produced from natural gas, a fossil fuel |
| Compatible with most engine types | Lower energy density than traditional marine fuels |
| Liquid, easier to handle | Can be corrosive and toxic |
Wind propulsion
Pros |
Cons |
| Beneficial for long crossings | Noise pollution |
| Can be combined with other renewable sources | Wind conditions can be variable and unpredictable |
| Zero emissions | Fitting vessels with wind propulsion systems can require significant investment upfront |
| Sustainable | Occupies a lot of space |
Shore-charged batteries
Pros |
Cons |
| Zero emissions (if electricity for charging is produced through green technology) | Still not efficient - cannot store enough energy for their size and weight |
| Practical for vessels that dock often | Emissions from charging power produced using fossil fuels |
| Can be charged using electricity from renewable sources | Requires collaboration between ports, shipping companies and utility providers |
| Reduced noise pollution | Impractical for vessels that do not dock often |
Liquefied petroleum gas (LPG)
Pros |
Cons |
| Easy storage | Not carbon free |
| Produces less SOx, NOx and CO2 than traditional marine fuels | Flammable and potentially hazardous |
| Widely available globally | Fluctuating prices |
| Efficient and reliable | Lower energy density than traditional marine fuels |
Liquefied natural gas (LNG)
Pros |
Cons |
| Reduces NOx emissions by up to 80% and virtually eliminates SOx particles compared with traditional marine fuels | Still a fossil fuel that emits CO2 and sometimes unburnt methane during combustion |
| Non-toxic and non-corrosive | Lower energy density than traditional marine fuels |
| LNG spills cause little marine environmental damage unless ignited before evaporation can occur | Converts to flammable gas when in contact with air |
| Widely available globally | Stored at a very low temperature and complex to handle |