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> I’m skeptical that these methanol ships are an improvement. And you should be. The damning fact about methanol is that it has a very low energy density. Per
by credit_guy 3y ago
> I’m skeptical that these methanol ships are an improvement.
And you should be.
The damning fact about methanol is that it has a very low energy density. Per wikipedia [1], one kilogram of diesel has an energy content of 45.6 MJ (megajoules). One kg of methanol has only 19.7 MJ. So, joule for joule, you need 2.3 tons of methanol for each ton of diesel you replace.
My guess is that these ships will forever remain "methanol capable", but will continue to run on regular diesel fuel. It's probably some scheme to get some green credits, just like the "flex fuel" cars in the US, which can run on ethanol, but most often don't.
[1] https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density
- SkyPuncher 3y agoMy impression is energy density matters significantly less with these giant ships.
- credit_guy 3y agoI ran some numbers. This ship can carry 7226 TEU containers; it has a gross tonnage of about 100k tons (93.5k to be precise) [1]. I found that a 5000 TEU carrier has a fuel capacity of 2 million gallons [2]. Since Anna Maersk can carry almost 50% more, its fuel capacity should be larger, but probably by less than 50% because of economies of scale. In any case, replacing diesel with methanol would require at least an additional 3 million gallons, which comes to 10000 tons. That's 10% of the gross tonnage of the ship. I suspect that no ship builder or operator will consider this a negligible amount. [1] https://www.wikidata.org/wiki/Q83601270 https://www.wikidata.org/wiki/Q83601270 [2] https://www.aol.com/many-gallons-fuel-does-container-142703880.html https://www.aol.com/many-gallons-fuel-does-container-1427038...