Methanol dual-fuel engines as a bridging technology
"In the long term, we see pure methanol single-fuel engines as the best solution," she says. At the same time, however, she recognizes the concern of many customers that green methanol will not be widely available in the medium term. For this reason, the Rolls-Royce engineers have also turned their attention to dual-fuel engines. "We see dual-fuel engines primarily as a bridging technology until green methanol is available across the board," says Kurtulus. "However, the length of this bridge varies depending on the application," says the expert. Yachts that call at ports all over the world will certainly rely on flexible dual-fuel propulsion for longer than ferry or tugboat operators who know their ports and therefore their fuel infrastructure.
However, the development of a dual-fuel methanol engine is not easy either. Here, Kech and his colleagues are more in the comfort zone - after all, this is also about self-igniting engines in which diesel is injected into the combustion chamber. But the aim here is to get by with as little diesel as possible. What's more, the existing diesel injectors now have to inject much smaller quantities of diesel. At the same time, the combustion chamber of the engine must not be optimized for methanol combustion, as the engine must continue to function in pure diesel mode. Compromises must therefore be made that limit the substitution rate and/or the efficiency of the engine.
There is no such thing as a "silver bullet"
However, both Denise Kurtulus and Johannes Kech are certain that the development effort is important. Both are convinced that there will not be just one single solution for environmentally friendly ship propulsion systems in the future. "There is no such 'silver bullet'," they emphasize. Instead, various solutions based on renewable energies are needed. One of these solutions will be mtu methanol engines. And they are not alone in this conviction. The Danish shipping company Maersk is already relying heavily on methanol. Not only has the company already put the first methanol-powered container ship into operation, it has also ordered over 20 more such ships. And as demand increases, so does the production of green methanol.