Challenges with Maritime Future Fuels – LNG celebration or controversy

In this blog post senior sustainability advisor Edward Levine discusses liquefied natural gas (LNG) as a maritime fuel.

As the world looks for ways to reduce GHG emissions and to limit the impact of climate change, the maritime industry is coming under increasing pressure to change course to more efficient and sustainable operational practices. International groups like the International Maritime Organisation (IMO), as well as private companies and the wider public are pushing for this change. But with many opportunities and technology innovations, it can be difficult to know where to start.

Future fuels are a key priority to achieving a zero-harm maritime industry, and LNG as a maritime fuel is gaining popularity, with a fivefold increase since 2016. LNG, a fossil fuel which primarily consists of methane, significantly reduces emissions of SOx, NOx, particulate matter, and CO2 when compared to other marine fuels. It has historically been used in LNG carriers, which typically use dual fuel engines and can switch between LNG and conventional bunker fuels, often when one fuel is cheaper than the other. In recent years it has been gaining popularity in vessel types such as ultra large containerships and capesize bulk carriers as it is seen by some as a better, less harmful fuel in terms of its air emissions, mainly due to its low sulphur content.

Adding to the recognised benefits of using LNG as a future fuel, supporters of LNG also say that while other alternatives are unproven and still in development, LNG can be used now and should have a wider role as a transitional fuel, until other fuels are ready for large scale use. These opportunities to move to low carbon fuels or fuels like LNG are cited as attractive, as they can allow companies to take short term action today as they take part in the transition to the full decarbonisation of shipping.

For all of the above recognised benefits to LNG, it also has many negative issues, which have attracted controversy. One of the main drawbacks to using LNG as a marine fuel is methane slip, which is the discharge of unburned methane from an engine. Other factors include the methane produced during the drilling, extraction and transportation process, known as “fugitive emissions”.

These important draw backs need to be understood in context of the overall global warming potential of methane slip and the LNG potential contribution to trapping heat in the earth’s atmosphere. All fossil fuels release methane, but due to the makeup of LNG, it has the potential to release a lot more methane than any other type of fossil fuel, purely through methane slip.

Industry leaders have also criticised the lack of bunkering infrastructure, which would require large investments to establish LNG as a widely available fuel for the maritime industry. The concept of such a large investment into a transitional fuel raises the question, could that infrastructure be used to support the widely agreed upon zero carbon fuels of the future, such as green hydrogen or green ammonia? If this infrastructure is only to be used for LNG based fuels, we need to ask ourselves is LNG worth the investment required today?

We recently published a positioning paper on LNG as a Maritime Future Fuel to provide the industry with a clear understanding into our position on LNG. In this paper we explore the pros and cons of LNG, the impact of methane slip and the infrastructure challenges the industry faces in implementing LNG as a long-term solution.

You can also read about the infrastructure challenges and limitations to LNG’s widespread adoption. In addition, we’ve assessed the current and future fuel requirements and have outlined the clear implications of using LNG as the widely available fuel for the maritime industry.