Sailing on methanol: what is required?
Methanol can become a sustainable alternative to diesel oil because it can be effectively used in an internal combustion engine, contains no sulfur, and produces fewer nitrogen oxides during combustion. The technology to sail on methanol is currently under development. Therefore, we do not yet have a complete overview of everything required, but ships and engine installations will certainly need significant modifications. Why are adaptations necessary, and what kind of research is being conducted on the use of methanol as a fuel for shipping?
Lower Energy Density
One of the main reasons why ships and engine installations need to be modified or redesigned is due to the lower energy density of methanol. Methanol weighs almost the same as diesel oil but contains slightly less than half the energy per liter. Therefore, for the same distance, you would need more than twice as much fuel. This affects the size of the bunker, the total weight of a ship, and the amount of cargo that can be transported. Additionally, you need to consider that the crankshaft and engine block will be more heavily loaded due to the higher combustion pressure required for using methanol as fuel.
Exhaust gas aftertreatment less complex
As mentioned, methanol contains no sulfur and produces fewer nitrogen oxides during combustion compared to diesel oil. The small amount of particulate matter emissions that exist come from the engine's lubricating oil consumption and the pilot fuel. It does not come from the methanol, which means that the exhaust gas aftertreatment can be less complex and smaller than with diesel engines, but not in the short term. There will always be a need for similar aftertreatment as with diesel engines as long as it is required that engines can run on both diesel oil and an alternative fuel (dual-fuel).
Safety regulations
The flash point of methanol is roughly between that of gasoline and diesel oil, requiring additional safety regulations for bunkering, storage, and the supply system. Therefore, the entire fuel system of a ship needs to be modified, or redesigned if it is a new ship.
There are also additional regulations for ventilation and vapor detection. High concentrations of methanol can be harmful to health.
Extensive research is being conducted on what other measures are necessary for the safe use of methanol as a fuel, for example in the Green Maritime Methanol project. Furthermore, it is good to know that methanol is not harmful to marine life because it is biodegradable.
The baseline for new systems is that they must be at least as safe as existing diesel systems.
Existing Ships vs. New Builds
For existing ships, transitioning from diesel to methanol is more complicated and expensive. Starting from the design process with a methanol system in mind will significantly reduce implementation costs. However, the average lifespan of a ship is 30 years, and each year approximately 3.3% of the fleet is replaced [source]. Therefore, it is logical that cost-effectively converting existing ships is a priority.
Building ships with future-proofing in mind can be a step in the right direction. This makes future conversions easier, contributing to lower future conversion costs. See also "Caterpillar Marine is proud to announce that Cat® 3500E-series marine engines can be modified to run as dual fuel methanol in the future" and "Caterpillar Marine to support select Cat® 3500E-series engines with dual fuel methanol."
Great need for more research
There is a great need for more research into the use of methanol as a fuel for shipping. That's why small-scale tests are so important. For instance, in 2020, Pon Power ran a Cat engine on methanol as a proof of concept. It was a great success. The concept wasn't intended to be brought to market, but it helped us better understand how methanol works as a fuel and what challenges we still need to address.
Another good example of learning by doing is the collaboration between Damen Shipyards, Caterpillar Inc, and Pon Power. In November 2022, these three parties signed a Memorandum of Understanding for the joint development of a series of dual-fuel methanol/diesel-powered tugboats. The aim of the collaboration is to learn jointly how (green) methanol can be optimally used as a fuel for ships, including all aspects of bunkering, storage, management, and power.
Diesel Will Remain Necessary for the Foreseeable Future
We are at the beginning of a major transition in shipping: moving from the fossil fuel diesel to alternative fuels like methanol. This will happen step by step, and we will learn more as we go. However, it also means that we cannot do without diesel for now. To ensure continuity, ships must be able to run on different fuels. Dual-fuel engines, which can run on both diesel and methanol, are therefore essential during the transition phase. Additionally, skippers must consider the availability of green methanol during their journey.
Sailing on methanol: conclusion
Pon Power believes that methanol has the greatest potential for success as an alternative fuel for maritime applications. It is liquid, more environmentally friendly, biodegradable in water, and an excellent engine fuel. You can read more about it in the article "Alcohol as Fuel: Challenges and Opportunities." In that article, we outline the pros and cons of alcohol fuels that can be used in engines. Additionally, the required modifications to ships and engine installations are significant but certainly not insurmountable. Therefore, we expect methanol to be widely used in the maritime sector in the future.
A Few Figures at a Glance
2
For the same distance, more than twice as much methanol is needed due to its lower energy density.
30 years
The average lifespan of a ship is 30 years.
3.3%
On average, 3.3% of the fleet is replaced each year.
2020
In 2020, Pon Power ran a Cat engine on methanol as a proof of concept better understand how methanol works as a fuel.
3 Companies
Damen Shipyards, Caterpillar Inc, and Pon Power are collaborating to learn how (green) methanol can be optimally used as a fuel for ships.
2022
The collaboration between Damen Shipyards, Caterpillar Inc, and Pon Power was formalized in a Memorandum of Understanding in November 2022.
More Information?
Would you like to know more about the use of methanol as a fuel for ships? Then contact your account manager or leave a message through our contact form. During office hours, you can also call us at +31 (0)78 642 0420.