As the UK and the transport sector acts towards decarbonisation, there are increasing interest in the use of alternative fuels, both drop-in fuels (also known as alternative diesel fuels) or low/zero carbon fuels, such as LNG, hydrogen or ammonia.
Drop-in alternative diesel fuels
The PLA has commissioned the University College London to perform an experimental study comparing the engine emissions from one of the Harbour Service vessels, Kew, when operating on Ultra Low Sulphur Diesel (ULSD), the neat (100% vol/vol) Gas-To-Liquid (GTL), and neat Hydrotreated Vegetable Oil (HVO). The results, together with the post-trials engine inspection and greenhouse gas emissions calculated helped the PLA to make an informed decision on switching from ULSD to lower emissions fuel across the fleet.
Alternative diesel fuel FAQs
What are alternative diesel fuels?
Alternative diesel fuels, defined here as fuels that are functionally equivalent to diesel fuel and are able to substitute diesel fuel without infrastructure or engine changes.These included Gas-To-Liquid (GTL), Hydrotreated Vegetable Oil (HVO).
Did the use of alternative diesel fuels cause any damage to the Kew’s engine?
No changes in the engine calibration were made prior the trial on Kew and no physical or visible operational issues, including no blockages and no signs of fuel breakdown, were experienced during the trials.The post-trials engine inspection also indicated no additional servicing was required and identified no significant wear and no signs of cylinder glazing, no signs of damage due to changing of combustion timing related to the higher cetane number, and reduced soot deposition on the piston crowns, valves and injector nozzles.
Did the use of alternative diesel fuels increase the fuel consumption rate on Kew?
No. The fuel consumption rate with ULSD, GTL, and HVO fuels were found not to be significantly different during the trial.
What are the environmental benefits of alternative diesel fuels?
Our exhaust gas monitoring demonstrated a reduction in nitrogen oxides (39-56% for GTL and 51-78% for HVO) and particulate matter (50-93% for GTL and 76-99% for HVO) emissions when operating with GTL and HVO relative to ULSD at all engine speeds.Using the UK government conversion factors, the use of HVO can reduce the greenhouse gas emissions associated with an organisation’s activities as the carbon dioxide emitted during combustion is deemed to have been offset by the absorption of carbon dioxide during growth of the biomass that forms the biofuel.
Other Alternative Fuels FAQs
What are the other alternative fuels and technologies?
Alternative fuels that are mostly prominent as the transition or long-term future fuels for the maritime sector includes LNG, LPG, methanol, hydrogen, ammonia, and technologies includes batteries, fuel cell system, and wind-assisted propulsion.An overview of what alternative fuels and technologies are available can be found on the DNV website and on-demand webinars and IMO website and on-demand webinars.
What is the outlook for the various types of fuel for the maritime sector?
For inland vessels, the focus has been mainly on battery electric and fuel cell technologies. You can find out more on this topic on the Emission Reduction Roadmap for Inland Waterways report undertaken by the PLA.
For shipping vessels, the future trend and forecast can be found from public sector research, such as Maritime Forecast to 2050 report by DNV, The Potential of Zero-Carbon Bunker Fuels in Developing Countries by the World Bank, Clean Maritime plan: Maritime 2050 environment route map from the Department for Transport and Maritime and Coastguard Agency.
The PLA is aware that fuel requirements and regulatory changes may be required and is preparing for this change, we have published a statement to set out what we are doing and how to bring new alternative fuels onto the river in the meantime.