With Alternative Fuels, Color Matters

Methanol is the simplest form of alcohol. It's composed of carbon monoxide, hydrogen, and a catalyst. It has similar energy properties to its cousin ethanol.

In 2020, maritime shipping, running primarily on heavy fuel oil, emitted around 940 million tons of carbon dioxide, which is about 2.8% of global emissions. It's the 4th largest emissions sector. One large container ship at sea emits the same amount of sulphur oxides as 50 million diesel-burning cars.

Therefore, it's welcome news that AP Moller-Maersk, the worlds second largest container shipping company, based in Denmark, announced a partnership with Mitsubishi Gas Chemical to build a green methanol supply base in Yokohama.

What do the colors of alternative fuels mean?

You'll hear discussion of alternative fuels by their color. Hydrogen and methanol have colors. We touched on blue vs. green hydrogen in the comments of an earlier article: LINK Briefly, here are the colors for methanol:

Brown Methanol and Gray Methanol

Brown methanol is made from coal. Because of the raw material, this is the most polluting and provides no climate benefit in comparison with just burning heavy fuel oil. Gray methanol is made from natural gas. This is slightly better than brown in terms of emissions, but still a very ineffective solution.

Blue and Green Methanol

Blue methanol is synthesized from blue hydrogen, which is hydrogen manufactured from natural gas, with carbon capture and storage of the produced CO2. The technology for the production of blue hydrogen is generally better positioned for scalability using current technology, but fossil fuels are still being extracted, and as some loss, including of natural gas (methane) in the process is inevitable, it still produces and leaks greenhouse gasses into the environment, although this leakage is potentially mitigated by carbon capture and sequestration.

Green methanol, on the other hand, is either produced in a bio-reactor from biomass waste, or possibly is synthesized from green hydrogen, which is hydrogen produced from water and electrolysis, rather than natural gas. If renewable energy is used for the electrolysis, it is effectively a zero emission fuel.

Switching from heavy fuel oil to green methanol can cut emissions by 60 to 95% according to the Methanol Institute. But presently green methanol is between two and four times more expensive than heavy fuel oil and is less energy dense.

The planned green methanol supply base that Maersk and Mitsubishi will be building in Yokohama will use food and livestock waste to generate methanol.

Current ships which use diesel motors powered by heavy fuel oil will not be able to easily switch to using methanol instead. But as cargo ships generally have a lifespan of 25-30 years, if the switch starts now, in quarter of a century or so, the carbon emissions from ocean cargo can drop significantly.

The International Maritime Organization agreed in July to net zero emissions from oceangoing vessels by 2050. And beginning next year in Europe, any cargo vessels serving the region over 5,000 tons (the majority of ocean cargo) will have to purchase emissions quotas. The emission credits are intended to speed up decarbonization by making it more expensive for older vessels to operate. In the end, the costs for the shift will likely be passed on to end consumers, who will have to pay more for things which come by ship. However they will also be some of the primary beneficiaries of the significant carbon reduction.