I’d like to start this week’s blog post by repeating that here at DNV we do not sell LNG. And we are looking at other alternative fuels for shipping, we are just not making as much noise about it. And we often receive questions like “why just LNG? how about this or that?” And methanol has come up surprisingly often lately.
So, let’s have a look at methanol.
In broad terms, methanol is produced either by converting methane through a synthesis process or directly by distillation of wood. Distillation of wood, however, does not seem economical for large scale production. This means methane is needed. And methane can come from two main sources:
- Biomass, such as wood
- Fossil hydrocarbons
It appears to me that the chief reason why methanol has come up as a potential fuel for shipping is that it is viewed as “green”. This of course comes from the fact that it can be produced from wood and other organic materials. So if we could produce enough methanol from wood to propel the world’s shipping fleet, the whole process would be carbon neutral.
Well then, can we produce enough methanol? No. Sorry if I pop your bubble.
It would consume 2,2 billion tons of wood yearly to propel the global fleet. Global production of wood is about 2,6 billion tons. Well, maybe it is possible, we just have to start planting a whole lot more trees. On football fields. Airport runways. Maybe drop that food production business.
Realistically, methanol for large scale application will be produced by converting methane from fossil hydrocarbon production. And this is the exact same methane that is liquefied and transported as LNG today. So methanol is merely an alternative transport mode for methane.
Conversion of methane to liquid fuels is done in several Gas-To-Liquids (GTL) plants today, and in general they are much more expensive than LNG plants. The GTL process also consumes about 30% of the energy in the gas. This compares with about 10% for the LNG process. Transportation costs would be about the same as the energy density is comparable. So, why choose methanol over LNG?
The only reason I can see is because methanol is liquid at atmospheric temperature, so it would be easier to distribute, store, and handle. For certain applications, such as small or specialized ships in isolated locations, perhaps there will be willingness to pay the extra cost to get the methane in liquid phase at atmospheric temperature, but for large volume applications, and international implementation, the conclusion appears evident:
Methanol is just a more expensive transport mode for methane.
Without going into safety aspects, combustion characteristics, and other details, I would recommend assessing the overall applicability before spending too much effort on methanol as a fuel for shipping. For pleasure crafts on the other hand, LNG can never be an alternative as it can’t handle long periods of idle storage, so maybe here lies the opportunity for methanol?