Methanol as a marine fuel
Driven by regulation and the desire to decarbonise, shipowners are looking at several different options to progress towards net zero, one of which is using methanol as a marine fuel.
Methanol is likely to be a viable option for vessel propulsion and power generation in the future and is closer to a “drop in solution” than other alternatives.
What is methanol?
Methanol (CH3OH3) is a light, colourless, flammable, and volatile liquid alcohol, also known as methyl-alcohol. In addition to its use as a fuel, it is used as a base chemical to produce many different commodities such as plastics, paints and building materials.
The different colours used to describe methanol refer to how it is produced and its feedstocks, as it is not a naturally occurrence substance.
Brown methanol: Produced using coal feedstock.
Grey methanol: Produced using natural gas as both the feedstock and process fuel.
Blue methanol: Produced using hydrogen and carbon dioxide (CO2) that has been extracted through carbon capture process.
Green methanol: Produced either from biomass or through electrolysis using renewable energy sources.
Much of the current demand is met by production from synthetic gases using coal or natural gas as a feedstock (brown and grey methanol). However, it is expected that there will be a shift towards blue and green methanol production in the future in accordance with life cycle analysis.
Methanol as a marine fuel
Methanol has a merged as a leading contender in the field of alternative fuels for vessels as the industry looks to decarbonise. Some of the reasons for this are:
Methanol has the lowest carbon content and highest hydrogen content of any liquid fuel.
Unlike some of the other proposed alternative fuels, it is a liquid at ambient temperatures and pressure, meaning:
it can be used on board a vessel with only relatively minor modifications needed, and therefore reduced capital expenditure costs to shipowners
it is easier to bunker, store and transfer
Wider industrial demand has led to increased production and therefore availability of this fuel.
It dramatically reduces sulphur oxide (Sox), nitrogen oxide (NOx) emissions and particulate matter when compared to traditional marine fuels. According to test data from Lloyd’s Register:
NOx emissions are reduced by about 60% when compared to HFO, though this will vary with engine load.
SOx emissions reduced by 99%.
Particulates down by 95%.
Dual fuel engines set up to burn grey or brown methanol can burn green and blue methanol without any further modifications.
Methanol has a greater energy density than ammonia and hydrogen.
The drawbacks of methanol as a marine fuel
There are challenges in switching to methanol as a fuel for vessels.
It is corrosive, which requires specific storage and handling.
It has a low flashpoint (12o C).
It is highly toxic.
Additional safety systems are needed in comparison with residual marine fuels and distillates.
Although it has a greater energy density when compared to ammonia and hydrogen, it is approximately 2.4 times lower in energy density when compared to residual or distillate fuels such as very low sulphur fuel oil or marine gas oil which means larger storage tanks are needed which may reduce cargo carrying capacity.
Lower carbon production methods such as green and bio-methanol will need to increase significantly to meet demand and other shoreside industries will compete.
Higher costs of methanol as a marine fuel when compared to traditional marine fuels.
Technical and operational aspects – expert Q&A with Lloyd’s Register
We spoke with Charles Haskell of Lloyd’s Register to discuss the technical and operational aspects.
How will IMO and EU legislation impact methanol production and usage?
The IMO’s Marine Environment Protection Committee (MEPC 80) recently adopted a revised strengthened strategy which aims to achieve net-zero CO2 emissions by or around, i.e., close to, 2050. There are some indicative checkpoints along the way; a reduction in carbon intensity of 20% striving for 30% by 2030, and 70% striving for 80% by 2040, compared to 2008 levels. There is also a target for low or zero carbon fuels uptake of at least 5%, striving for 10%, by 2030.
FuelEU Maritime comes into effect in 2025. The regulation sets targets for reducing the yearly average greenhouse gas (GHG) intensity of the energy used by a ship or, crucially, by a fleet or pool of ships. The required GHG intensity reduction starts small, at 2% in 2025 (compared to a 2020 baseline), reaching 6% in 2030 and 14.5% in 2035, through to 80% by 2050.
Additional emissions trading mechanisms are under consideration in other regions including China, USA and the UK. If developed, these additional regional mechanisms, combined with the EU’s Fit for 55 packages, will cover much of the major global trading blocs. However, it is unlikely that each regional scheme will be the same, leading to a fragmented global approach to decarbonisation, within the maritime sector.
The above support the investment case for the use of blue and green methanol and therefore begin to de-risk the larger investments required for the production facilities both regionally in the EU and, following MEPC 80, globally.
How do you see the adoption of methanol as a marine fuel compared to other alternative fuels such as biofuels, ammonia, and hydrogen?
Methanol is unique because it’s an established fuel as well as a new candidate. It has been used on ships for years. However, fuel production methods need to shift from fossil to renewable to make it viable.
Methanol technology is tested, and most engine makers will have dual fuel two-stroke or four-stroke diesel or otto-cycle engines available now or soon.
How safe is methanol?
Methanol is often seen as one of the safer of the fuels proposed for the future, but it is still toxic and extreme care is required with handling. It can be absorbed into the body by inhalation, ingestion, skin contact, or eye contact. Adverse health effects of methanol contamination or exposure are not always immediately evident and can be fatal.
The fuel will also react violently with strong oxidants, raising the risks of fires and explosions in the event of a leak. Methanol evaporative vapours may be heavier than air, causing them to spread along the ground and collect and stay in poorly ventilated, low-lying, or confined areas, such as engine room bilge areas.
There are numerous safety guidance publications as methanol is a regularly used chemical feedstock and maritime cargo. Lloyd’s Register and the Methanol Institute developed robust guidance on methanol bunkering processes in 2020 with the publication of the ‘Introduction to Methanol Bunkering Technical Reference’. The Methanol Institute has also regularly updated its ‘The Methanol Institute Safe Handling Manual (4th edition)’.
Potential methanol bunker suppliers, ports and users should also be aware of work of the CEN Workshop Agreement in Europe. CEN, the European Committee for Standardization, is one of three bodies recognised by the European Union as being responsible for developing and defining voluntary standards at European level. The methanol bunkering workshop agreement was in partnership with industry actors including Lloyd’s Register and the Methanol Institute.
Pollution risks – expert Q&A with ITOPF
We asked Andrew Le Masurier of ITOPF on the chemistry of methanol and the environmental impact of spills.
What are the environmental risks associated with the release of methanol into the water?
Once spilled into the marine environment, methanol would spread on the surface and undergo dissolution into the water body while simultaneously be lost to the atmosphere via evaporation.
The methanol will dissolve in the water, potentially having a toxic impact in the immediate vicinity. But concentrations will rapidly reduce due to the buffering and dilution within the water body and long-term impacts are predicted to be negligible. Methanol is fully miscible in water, which means that it has no limit to its solubility and can never meet a point of maximum saturation. Therefore, irrespective of the amount of methanol spilled, it will always be possible to dissolve into the receiving water body. Due to this property, a large release to open water will dissipate to non-toxic levels (<1%) at a rate significantly faster than petroleum-based fuels.
The rate at which methanol will dissipate will depend on the amount of mixing in the aquatic environment, led by tidal flows combined with wind-induced wave action. Significant research has been conducted in the speed of contaminant mixing in surface waters for petroleum products, but the research and data has not been so extensive for methanol.
When it comes to spills of petroleum-fuels with a large amount of light hydrocarbon compounds, such as diesel, a drawback of its short-term latency on the water surface is that it tends to be more readily bioavailable for organisms in the vicinity, leading to higher toxic impacts and mortalities. However, because methanol has generally less chronic toxicity than petroleum fuels and it dissipates at a more rapid rate, it means that concentrations are rarely likely to remain high enough to have a significant long-term effect on marine life.
How would a clean-up operation from a methanol spill compare to that of other fuels?
The spill response industry is likely to see a significant shift from protracted shoreline clean-up operations spanning large areas, which are typical for oil spills, to short-term localised events whereby the main approach may be to simply monitor and evaluate the risks to receptors.
As mentioned above, due to methanol’s short residence time on the sea surface due to its loss to the atmosphere and the surrounding water body, the spill is most likely to have naturally attenuated before resources could be mobilised to the area.
Nevertheless, there are still significant risks to responders and nearby receptors, especially during a continuous release of methanol due to its vapour’s toxicity and flammability. The role of monitoring and evaluating will be a highly valuable approach in the “response toolbox”.
Another consideration would be atmospheric plume modelling, which can subsequently inform national authorities as to the risks to nearby human or environmental receptors if an incident is closely located to a populated/environmentally sensitive area. To provide an idea of the potential affected area, ITOPF attended an oil spill caused by a methanol explosion in Malaysia in 2012 and property damage in the form of damaged buildings was reported approximately 800 m from the site of the explosion.
Another consideration is the use of sensors, possibly remotely controlled, to measure vapour concentrations in the air or methanol concentrations in the water column near to the point of release. This method could be an effective way of ‘ground-truthing’ modelling results and allowing for quantitative data to be collected on the possible impacted area. It should also be noted that these detection techniques are necessary to assess the fate and behaviour of the methanol immediately after or during a spill due to its appearance. As a clear liquid that is fully miscible with water it is extremely difficult to detect via remote imagery or by eyesight prior to dissolution into the surrounding water body.
How would the costs associated with a methanol release compare with a bunker fuel spill?
The costs are likely to be very different to a spill of conventional oil. As there is minimal likelihood of a spill response both at sea and on the shoreline, the significant costs usually associated with these activities would not be necessary. However, costs relating to possible fire-fighting measures may be significant.
In addition, a large cost item usually associated with fuel spills from vessels concerns waste collection, transport, and disposal. But as methanol is lost to both the atmosphere and the surrounding water body, no waste is likely to be generated.
Response costs would likely include provision of modelling expertise, monitoring equipment and wider overall technical advice in the immediate time following the incident.
If a continuous slow release was recorded, some preventative measures may also be claimed such as repairing any leak or crack in the vessel’s structure to stop the release.
Death and personal injury claims could occur following either an explosion caused by a methanol leak or from nearby receptors being exposed to toxic concentrations of methanol in the immediate vicinity. Another claim type that is likely to be experienced would be economic loss to fishing or other vessel types, wider economic impacts on reduction of port activities if an area were to be damaged.
Post spill monitoring and environmental studies may be claimed, given the relatively low international experience on these types of incidents. In addition, claims related to reasonable measures for reinstatement might be received. However, it is not clear as to what extent studies and reinstatement would be necessary due to the expected short-lived nature of environmental damage.
It should also be noted that it is currently not clear as to the extent to which these types of claims are captured by the current definitions of ‘pollution damage’ and ‘damage’ in the IMO’s liability and compensation conventions, such as the International Convention on Civil Liability for Oil Pollution Damage (CLC), the 2001 Bunkers Convention and the 2010 HNS Convention (which is not yet in force). The potential for legislative gaps within existing IMO liability and compensation conventions for these new fuel types exist and it is necessary for there to be clarification on this matter before these vessels become more commonplace within the international fleet.
How should the shipping industry prepare for these new fuel types?
From a spill response perspective, there is limited to no experience of significant spills of these new fuel types and therefore there is a large gap in understanding the real-life impacts and consequences of these incidents. Those organisations that have experience of incidents involving these fuels should share their lessons learned and provide information to the wider industry to ensure that organisations and governments are able to best prepare for these events and ensure that best practice is being followed. The shipping, spill response and salvage industry are all in this together and as long as openness and sharing of information is promoted, it will stand us in good stead to react to incidents of this nature in the future.