Global shipping produces approximately 3% of global CO2 emissions.
Container ships have predominantly relied on ‘bunker fuel’ as their energy dense fuel of choice. However, bunker fuel produces carbon dioxide and black carbon, and it is this fine particulate which can absorb a million times the energy of CO2.
With nearly 90% of global goods being shipped in cargo containers, this is still the cheapest method of moving goods, making it very appealing to global companies.
However, commercial marine vessels have additional issues to contend with, namely long service lives with bulk carriers, tankers and container ships the main contributors to GHG’s.
The International Maritime Organisation (IMO) as part of their GHG Strategy have set a reduction in carbon intensity on international shipping.
They aim to reduce CO2 emissions per transport work – as an average across international shipping – by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008. The IMO have set a target for total annual GHG emissions from international shipping to be reduced by at least 50% by 2050 compared to 2008. (1)
Until recently, most ocean-going ships used HFO to power their engines. The fuel was so popular that according to the IMO it made up 86% of international ship fuel used. Since the mid-19th century, HFO was a logical choice for ships because it is very high in energy — so a little takes a ship a long way. (2)
“Black carbon”, particles which absorb sunlight while airborne, contribute to global warming by decreasing the amount of solar energy reflected into space (the albedo effect) and increase the rate of ice melt in polar regions. (2)
Research and development around the globe are forging new ways to fuel commercial marine vessels and in doing so reduce emissions to the levels set by the IMO. The challenges this poses are considerable, as there is no single economically viable decarbonisation solution for heavy duty vehicles and vessels.
To support the decarbonisation of the transport sector, hydrogen is being hailed as one solution for the heavy-duty sector. However, it is Ammonia (NH3) which is being researched and developed as an alternative to HFO in the marine sector.
Ammonia having been shipped as bulk cargo for some 100 years, means that the marine industry is familiar with its use and handling.
However, there are still a handful of challenges that the marine industry must overcome before shipowners can safely use ammonia as fuel. These range from questions of risk and safety to regulatory concerns and assessing all aspects of ammonia’s sustainability as a fuel. (3)
With the need for further data and development of a stable, sustainable, and readily available source of ammonia for shipping and marine vessels, there are a host of research and development programmes being undertaken worldwide.
In the United Kingdom, The University of Nottingham Faculty of engineering UK are running research programmes to establish the viability of ammonia as a marine fuel.
One of their projects seeks to determine the energy and air quality impacts and potential future applications of a novel ammonia-fuelled heavy duty IC engine operating with high efficiency (c.50% brake) and zero emissions through a new fast burning combustion system. (4)
The project will evaluate potential reductions in energy demand in the ‘green’ ammonia production process, making use of the new green ammonia pilot plant at the Rutherford Appleton Laboratories. To assess relative advantages and challenges, the project will undertake evidence-based life cycle analysis across a spectrum of competing decarbonised powertrain technologies for long-range heavy-duty transport (ground, freight rail and marine). (4)
Another project having been awarded a £5M investment from UKRI Innovate UK Engineering and Physical Sciences Research Council, focuses specifically on the development of ‘Decarbonised Clean Marine: Green Ammonia Thermal Propulsion (MariNH3)’
MariNH3 is a five-year research programme to develop new and disruptive engine technology which will significantly cut GHGs, and pollution emitted by diesel powered marine vessels.
Dolphin N2, alongside other industry partners and a host of university professors, aim to overcome the key related technical, economic, and social unknowns of the development of green ammonia (NH3) through flexible, multidisciplinary research set around disruptive NH3 engine concepts capable of high thermal efficiency and ultra-low NOx. (5)
Ammonia (NH3) has excellent potential to play a significant role as a sustainable future fuel in both retrofitted and advanced engines. Significant uncertainties remain around safe and effective end use, with these unknowns spanning across fundamental understanding, effective application, and acceptance. (5)
The goal is to accelerate understanding, technologies and ultimately policies which are appropriately scaled and “right first time”. (5)
All the UK research and development programmes are in alignment with the UK government Clean Growth Strategy, Clean Air Strategy and Maritime 2050, with projects examining a novel solution for full decarbonisation of the marine sector, alongside the need to decarbonise heavy duty.
Written and cited by Katy Mason for and on behalf of Dolphin N2.