Last year, the shipping company Maersk announced the order of eight high-capacity container ships (16,000 TEU) capable of running on green methanol. In the end, there will be 12 ships, which in turn will require a huge amount of fuel. Green methanol is a technology that is already available, but a gigantic order has to be placed; for batteries, there is still a long way to go. The first ship will be launched in 2023.
Maersk has teamed up with six strategic partners for the mass production of green methanol. On the one hand, this can be obtained from usable waste (biomethanol). On the other, through surplus renewable energy to make it synthetic (e-methanol).
The order is for at least 730,000 tons of e-methanol per year by the end of 2025. Maersk will thus have its first large container ships free of net carbon emissions. However, the goal is to make its operation completely carbon neutral by 2050.
However, there is a possibility that these ships will not have the required green methanol. This is when biofuel engines come into the equation. The engines can run on either methanol or conventional low-sulfur fuel. The latter increases the cost of each ship by 10-15%.
There are always exhaust emissions. Even so, with the use of green methanol, the dozen ships will avoid the net emission of one million tons per year.
Biomethanol, an alternative to synthetic methanol
The alternative to synthetic methanol is biomethanol. By way of review, methanol can be safely stored at ambient temperature and pressure in conventional tanks. Moreover, it does not boil down to 64.7 °C and freezes at -97.6 °C. Every 1,000 liters weighs 792 kg, making it less dense than water. Its cost is currently slightly higher than marine fuel by weight ($600/ton in 2021), twice as much if we convert it to megajoules.
In other words, the CO2 needed to produce methanol is captured from that already emitted, so when the ship’s engines consume the methanol, the CO2 is released again. Theoretically, it is the same, but the engines produce very little toxic pollution. Even so, they do produce emissions, albeit through oil consumption. It is a happy medium between using heavy diesel and 100% emission-free fuels.
As we can see, the resolution of the problem goes in phases. Ships need methanol, synthetic methanol needs hydrogen. In turn, for hydrogen to be emission-free, it must be produced with renewable energy as well. If renewables are used throughout the process, the net carbon emission is zero. That is if we discount the production of the equipment, the construction of the plants, etc.
The fleet of 12 containerships will replace ships currently in service that are scheduled for retirement until 2024. These mega-ships produce brutal pollution if they use so-called bunker fuel. In 2018, Maersk announced that it would have its first zero-emission vessel by 2030. Later, it announced that in 2023 it will have the first ship with a capacity of 2,000 containers powered by green methanol.
Source: Forococheselectricos (2022)