Hydrogen or ammonia? Neither. According to a new report, green methanol is the key to the climate-free shipping of the future.
There’s a lot of talk about hydrogen and ammonia as the marine fuels of the future. And in Longspur research's (a finance company that invests in clean energy) report All at sea - Methanol and shipping, they are of course included in the discussion about which fuel is currently best suited to lead the way to fossil-free shipping.
However, the great potential of hydrogen is not as a fuel but as a building block for producing green ammonia and green methanol. which takes up precious space ", writes Longspur. Ammonia then? Ammonia does not require cryogenic tanks as it can be stored as a liquid at -33⁰C but it is toxic and there is a risk that nitrous oxide, which is a very strong greenhouse gas, is formed during combustion.
Ammonia's main competitor, methanol, is no more toxic than conventional marine diesel. But methanol is not only easier to handle from a safety perspective, it also has other major benefits:
”Firstly, it is available today and is technology proven so can be selected for new build or it can be retrofitted to existing fleets. It is dense enough to be useable without significantly displacing load capacity and it is useable without too many hazards. It can be bunkered vessel to vessel or shore to vessel. Finally, it is the lowest cost option at the point of delivery", writes Longspur. "If you take all these factors into account, it indicates that methanol is the best solution available today."
Longspur is in good company. Recently, several giants in shipping have embraced methanol as a leading alternative fuel. Maersk has ordered several methanol-powered container vessels and Rolls-Royce plans to develop new high-speed engines that run on methanol. First, however, was Stena, which already in 2015 converted a ferry to methanol operation. In June 2021, they took another step when Stena Germanica refueled and test-drove a more sustainable methanol that has been recycled from the Swedish steel industry.